Najnowsze publikacje

Streszczenie:
As the critical feature of the stick-slip for soft materials, the interfacial Schallamach waves of flexible composite structures are essential for smart tactile sensors to realize sliding perception. Herein, the Schallamach waves of polydimethylsiloxane film/substrate bilayer structures with three substrate stiffnesses regulated by porosities are investigated by setting up in-situ sliding tests and establishing finite element models with mixed-mode cohesive contact. Inhomogeneity in microcontact stiffness disrupts the continuity and synchronization of the Schallamach waves, resulting in non-periodic fluctuations in the contact force. The buckling phenomenon of the film structure marks the transition from stick to slip. This buckling induces a shift at the crack front from normal compressive stress to tensile stress, leading to mixed-mode damage.

Słowa kluczowe:
Stick-slip,Polydimethylsiloxane film/substrate bilayer structures,Schallamach wave,In-situ sliding test,Mixed-mode cohesive contact model

Streszczenie:
Background
Metrics evaluating the functional quality of red blood cells (RBCs) must consider their role in oxygen delivery. Whereas oxygen-carrying capacity is routinely reported using haemoglobin assays, the rate of oxygen exchange is not measured, yet also important for tissue oxygenation. Since oxygen-unloading depends on the diffusion pathlength inside RBCs, cell geometry offers a plausible surrogate.
Methods
We related the time-constant of oxygen-unloading (τ), measured using single-cell oxygen saturation imaging, with flow-cytometric variables recorded on a haematology analyser. Experiments compared freshly-drawn RBCs with stored RBCs, wherein metabolic run-down and spherical remodelling hinder oxygen unloading.
Findings
Multivariable regression related τ to a ratio of side- and forward-scatter, referred to herein as FlowScore. FlowScore was able to distinguish, with sensitivity and specificity >80%, freshly drawn blood from blood that underwent storage-related kinetic attrition in O2-handling. Moreover, FlowScore predicted τ restoration upon biochemical rejuvenation of stored blood. Since RBC geometry and metabolic state are related, variants of FlowScore estimated [ATP] and [2,3-diphosphoglycerate]. The veracity of FlowScore was confirmed by four blood-banking systems (Australia, Canada, England, Spain). Applying FlowScore to data from the COMPARE study revealed a positive association with the time-delay from sample collection to measurement, which was verified experimentally. The LifeLines dataset revealed age, sex, and smoking among factors affecting FlowScore.
Interpretation
We establish FlowScore as a widely-accessible and cost-effective surrogate of RBC oxygen-unloading kinetics. As a metric of a cellular process that is sensitive to storage and disease, we propose FlowScore as an RBC quality marker for blood-banking and haematology.

Słowa kluczowe:
Haematology,Erythrocytes,Storage lesion,Assay,Oxygen transport,Transfusion

Streszczenie:
The subject of research is a steel arch-tied bridge at a high-speed railway line in Poland. After the construction was completed, a resonance phenomenon was observed at the bridge, consisting of the occurrence of intense (visible to the unaided eye) undamped vibrations of some vertical hangers in the horizontal direction, transverse to the track axis. These vibrations occurred without the presence of a railway load on the bridge. Before the bridge was put into operation, an acceptance static and dynamic load test was performed, and then the bridge deck vibrations were monitored for a year. The research during dynamic loads testing included both quasi-static (10 km/h) and high-speed (200 km/h) testing train passages. The vertical displacement measurements were carried out in three cross sections of the span, and the acceleration of vibrations on girders and selected hangers was also measured. Next, an innovative system for determining displacements indirectly using inertial sensors (inclinometers and accelerometers) was used for bridge deck vibration monitoring. The primary aim of the research was to investigate the possibility of assessing the safe operation of the bridge using a monitoring system consisting of a limited number of inertial sensors. The second aim was to verify the feasibility of calibrating the numerical model based on the results of dynamic load testing. Numerical analyses of the behavior of the bridge during the passage of trains with speeds up to 200 km/h were carried out. The developed and calibrated numerical model provides additional information about the overall structural vibrations, facilitating the interpretation of outcomes of the monitoring system. No significant impact of hanger vibrations on the monitored displacements and accelerations of the bridge deck vibrations during the passage of trains was found.

Słowa kluczowe:
Arch-tied railway bridge,Bridge monitoring,Load testing,Bridge vibration,Numerical model calibration

Streszczenie:
The development of bone tissue engineering, a field with significant potential, requires a biomaterial with high bioactivity. The aim of this manuscript was to fabricate a nanofibrous poly(L-lactide) (PLLA) scaffold containing nano-hydroxyapatite (nHA) to investigate PLLA/nHA composites, particularly the effect of fiber arrangement and the addition of nHA on the piezoelectric phases and piezoelectricity of PLLA samples. In this study, we evaluated the effect of nHA particles on a PLLA-based electrospun scaffold with random and aligned fiber orientations. The addition of nHA increased the surface free energy of PLLA/nHA (42.9 mN/m) compared to PLLA (33.1 mN/m) in the case of aligned fibers. WAXS results indicated that at room temperature, all the fibers are in an amorphous state indicated by a lack of diffraction peaks and amorphous halo. DSC analysis showed that all samples located in the amorphous/disordered alpha' phase crystallize intensively at temperatures just above the Tg and recrystallize on further heating, achieving significantly higher crystallinity for pure PLLA than for doped nHA, 70 % vs 40 %, respectively. Additionally, PLLA/nHA fibers show a lower heat capacity for PLLA in the amorphous state, indicating that nHA reduces the molecular mobility of PLLA. Moreover, piezoelectric constant d33 was found to increase with the addition of nHA and for the aligned orientation of the fibers. In vitro tests confirmed that the addition of nHA and the aligned orientation of nanofibers increased osteoblast proliferation.

Słowa kluczowe:
Scaffolds, Tissue engineering, Bone tissue engineering, Smart medicine, Biodegradable polymers, Regenerative medicine

Streszczenie:
Taking into account energy demand a new highly conducting ionic liquid (IL) c (EmImTCM) mixed corn starch (CS) biopolymer electrolyte is synthesized for dual electrochemical application electric double layer capacitor (EDLC) and the dye-sensitized solar cell (DSSC) application. Electrical, structural, thermal, and optical studies are carried out in detail and presented in this communication. Maximum conducting IL-incorporated biopolymer electrolyte film has been sandwiched between electrodes to develop EDLC and DSSC. The sandwich-structured EDLC delivers a high specific capacitance of 250 F/gram while DSSC shows 1.44 % efficiency at one sun condition.

Słowa kluczowe:
Corn starch, Biopolymer, XRD, TGA, EDLC, DSSC

Słowa kluczowe:
zkSNARKs, Proof of Provenance, C2PA, Folding Schemes

Streszczenie:
In this paper, small-scale testing techniques—nanoindentation and micropillar compression—were used to investigate the deformation mechanisms, size effects, and strain rate sensitivity of (100) and (110) single-crystal Gum Metal at the micro/nanoscale. It was observed that the (100) orientation exhibits a significant size effect, resulting in hardness values ranging from 1 to 5 GPa. Conversely, for the (110) orientation, this effect was weaker. Furthermore, the yield strength obtained from the micropillar compression tests was approximately 740 MPa for the (100) orientation and 650 MPa for the (110) orientation. The observed deformations were consistent with the established features of the deformation behavior of body-centered cubic (bcc) alloys: significant strain rate sensitivity with no depth dependence, pile-up patterns comparable to those reported in the literature, and shear along the {112}<111> slip directions. However, the investigated material also exhibited Gum Metal-like high ductility, a relatively low modulus of elasticity, and high yield strength, which distinguishes it from classic bcc alloys.

Streszczenie:
This paper introduces a first-time investigation into the impact of power ultrasound (PUS)-assisted preparation on the physicochemical and mechanical properties of cement-granulated blast furnace slag (GBFS) composite pastes. Pastes containing deposited GFBS with varying particle size fractions, partially replacing Portland cement, were prepared using PUS (ultrasonic horn tip, 20 kHz, 700 W) in pulse mode in a vertical jacketed glass sonoreactor with closed-circuit cooling. Cement paste incorporating 20 wt.% GBFS as mass substitution with varying particle size fractions was characterized by several physicochemical techniques at different curing ages. Exploring the cement and GBFS interaction induced by PUS, the compressive and flexural strength, the elastic modulus and indentation hardness, the heat of hardening, the mineral composition of hydration products, and the specific surface area BET were evaluated for a curing time of up to 28 days. The grain size distribution of GFBS and the reaction mixture's pH were measured. Both mechanical properties, heat of hydration and nanoporosity exhibited strong sensitivity to PUS treatment. Sonofragmentation of GBFS particles (especially the 125–250 μm fraction) increased with increasing sonication time, resulting in a relative increase of fraction <63 μm and a decrease of fraction >125 μm by 275 % and 60 %, respectively. Using the obtained SEM-EDS data, a simplified mechanism is proposed to explain the effects induced by PUS treatment.

Słowa kluczowe:
Power ultrasound treatment, Portland cement, Granulated blast furnace slag, Early strength development, C-S-H/C-A-S-H, Seeding effect

Streszczenie:
AISI 304 steel experiences plastic flow instability during tension at room temperature if appropriate conditions are applied: a low strain rate and a sufficiently long gauge section of the sample. Then, propagation of the strain-localised band is activated. The electron backscattered diffraction (EBSD) research revealed that the reason is not only the difference in the content of the secondary phase – martensite α’ across the front face, but also the change in the volume fraction of austenite grains with Copper (Cu) and Goss-Brass (GB) orientation. Consequently, there is a division between two areas of high and limited deformation capacity. The tendency to maintain the continuity of deformation fields induces a massive rotation of austenite grains to Cu and GB orientations, which then undergo shearing and phase transformation. As a result, momentary strain accumulation leaves behind a stiffer zone. It is shown that the trapping of austenite grains prone to large deformations, inside the matrix with Cu and GB orientations, makes the formation of a plastic strain front possible. These features improve the ductility and strength of the 304 steel over 316L and 316LN at room temperature. The in-situ EBSD tension studies for the considered grades reveal three developing textures, with their comparison showing a gradual decrease in the preferences of the Cu and GB components. Thus, the appearing bands of the accumulated strains in 316L are limited by the Cu and GB areas, while such blockages do not occur in 316LN. The presented strengthening mechanism is confirmed by the digital image correlation (DIC) measurements. The root-mean-square (RMS) function of strains along the tensile direction, characterising the linear surroundings of the considered point, is introduced as a tool for linking the micro and macro scales. The experimental results provide a basis for explaining discontinuous front propagation at a temperature near 0 K.

Słowa kluczowe:
Plastic flow instability, Martensitic transformation, Austenitic stainless steels, RMS strain amplitude

Streszczenie:
Mitochondrial proteins are transported and sorted to the matrix or inner mitochondrial membrane by the presequence translocase TIM23. In yeast, this essential and highly conserved machinery is composed of the core subunits Tim23 and Tim17. The architecture, assembly, and regulation of the human TIM23 complex are poorly characterized. The human genome encodes two paralogs, TIMM17A and TIMM17B. Here, we describe an unexpected role of the ovarian cancer immunoreactive antigen domain-containing protein 1 (OCIAD1) and the prohibitin complex in the biogenesis of human TIM23. Prohibitins were required to stabilize both the TIMM17A- and TIMM17B-containing variants of the translocase. Interestingly, OCIAD1 assembled with the prohibitin complex to protect the TIMM17A variant from degradation by the YME1L protease. The expression of OCIAD1 was in turn regulated by the status of the TIM23 complex. We postulate that OCIAD1 together with prohibitins constitute a regulatory axis that differentially regulates variants of human TIM23.

Słowa kluczowe:
biogenesis, mitochondria, OCIAD1, prohibitin, TIM23 translocase

Streszczenie:
Rational design of novel antibody therapeutics against viral infections such as coronavirus relies on surface complementarity and high affinity for their effectiveness. Here, we explore an additional property of protein complexes, the intrinsic mechanical stability, in SARS-CoV-2 variants when complexed with a potent antibody. In this study, we utilized a recent implementation of the GōMartini 3 approach to investigate large conformational changes in protein complexes with a focus on the mechanostability of the receptor-binding domain (RBD) from WT, Alpha, Delta, and XBB.1.5 variants in complex with the H11-H4 nanobody. The analysis revealed moderate differences in mechanical stability among these variants. Also, we identified crucial residues in both the RBD and certain protein segments in the nanobody that contribute to this property. By performing pulling simulations and monitoring the presence of specific native and non-native contacts across the protein complex interface, we provided mechanistic insights into the dissociation process. Force-displacement profiles indicate a tensile force clamp mechanism associated with the type of protein complex. Our computational approach not only highlights the key mechanostable interactions that are necessary to maintain overall stability, but it also paves the way for the rational design of potent antibodies that are mechanostable and effective against emergent SARS-CoV-2 variants.

Słowa kluczowe:
SARS-CoV-2, GōMartini 3, Nanomechanics, Protein complexes, protein engineering, MD, native contacts

Streszczenie:
The dynamics of a single highly elastic fibre settling under gravity in a very viscous fluid is studied numerically. We employ the bead model and multipole expansion of the Stokes equations, corrected for lubrication that is implemented in the precise Hydromultipole numerical codes. Four attracting regular dynamical modes of highly elastic fibres are found: two stationary shapes (one translating and the other rotating and translating), and two periodic oscillations around such shapes. The phase diagram of these modes is presented. It illustrates that the existence of each mode depends not only on the elasto-gravitation number but also on the fibre aspect ratio. Characteristic time scales, fibre deformation patterns and motion in the different modes are determined.

Słowa kluczowe:
stokesian dynamics, particle/fluid flows

Streszczenie:
The paper presents and discusses the results of a study of the thermal properties of cement composites with different contents of magnetite aggregate (0%, 20%, 40% and 60% by volume). The effect of grain size on the evaluated thermal properties was also investigated. For this purpose, concrete containing 50% by volume of magnetite aggregate with four different fractions (1–2 mm, 2–4 mm, 4–8 mm and 8–16 mm) was used. Thermal parameters were evaluated on specimens fully saturated with water and dried to a constant mass at 65 °C. The series with varying grain sizes of magnetite achieved thermal conductivity values in the range of 2.76–3.03 W/(m·K) and 2.00–2.21 W/(m·K) at full water saturation and after drying to a constant mass, respectively. In the case of the series with 20% magnetite by volume, the thermal conductivity was 2.65 W/(m·K) and 1.99 W/(m·K) for the material fully saturated with water and dried to a constant mass, respectively. The series with a 60% volume share of magnetite obtained values of this parameter of 3.47 W/(m·K) and 2.66 W/(m·K), respectively, under the same assumptions.

Słowa kluczowe:
shielding concrete, thermal properties, magnetite aggregate

Streszczenie:
In this work, tantalum-doped tungsten boride ceramic coatings were deposited from a single sputtering target with the radio frequency (RF) and high-power impulse magnetron sputtering (HiPIMS) methods. Two-inch torus targets were synthesised from pure elements with the spark plasma sintering (SPS) method with a stoichiometric composition of W1-xTaxB2.5 (x = 0, 0.08, 0.16, 0.24). Films were deposited with RF and HiPIMS power suppliers at process temperatures from RT to 600 °C. The substrate heating and the energy of the ionised material impacting the substrate increase the surface diffusivity of adatoms and are crucial in the deposition process. The results of SEM and XRD investigations clearly show that the addition of tantalum also changes the microstructure of the deposited films. The coatings without tantalum possess a finer microstructure than those with 24% of tantalum. The structure of films is homogeneous along the film thickness and composed mainly of columns with a (0001) preferred orientation. Deposited coatings are composed mainly of P6/mmm α-WB2 structures. The analysis of nanoindentation results allowed us to determine that ceramic coatings obtained with the HiPIMS method possess hardness above 41 GPa and a ratio of hardness to reduced Young modulus above 0.1. The thickness of HiPIMS-deposited films is relatively small: only around 60% of the RF magnetron sputtered coatings even when the average power input was two times higher. However, it has been shown that the RF coatings require heating the substrate above 400 °C to obtain a crystalline structure, while the HiPIMS method allows for a reduction of the substrate temperature to 300 °C.

Słowa kluczowe:
RF magnetron sputtering, HiPIMS magnetron sputtering, Superhard ceramic coatings, Transition metal borides, Deposition temperature

Streszczenie:
The demand for pseudopotentials constructed for a given exchange-correlation (XC) functional far exceeds the supply, necessitating the use of those commonly available. The number of XC functionals currently available is in the hundreds, if not thousands, and the majority of pseudopotentials have been generated for LDA and PBE. The objective of this study is to identify the error in the determination of the mechanical and structural properties (lattice constant, cohesive energy, surface energy, elastic constants, and bulk modulus) of crystals calculated by DFT with such inconsistency. Additionally, this study aims to estimate the performance of popular XC functionals (LDA, PBE, PBEsol, and SCAN) for these calculations in a consistent manner.

Słowa kluczowe:
DFT, pseudopotentials, exchange–correlation functionals

Streszczenie:
Sialodacryoadenitis virus (SDAV) has been identified as the etiological agent responsible for the respiratory system and salivary gland infections in rats. The existing literature on SDAV infections is insufficient to address the topic adequately, particularly in relation to the central nervous system. In order to ascertain how SDAV gains access to neuronal cells and subsequently exits, our attention was focused on the small molecule valosin-containing protein (VCP), which is an ATPase. VCP is acknowledged for its function in the ubiquitin-mediated proteasomal degradation of proteins, including those of viral origin. To ascertain the potential influence of VCP on SDAV replication and egress, high-content screening was employed to determine the viral titer and protein content. Western blot analysis was employed to ascertain the relative expression of VCP. Real-time imaging of SDAV-infected cells and confocal imaging for qualitative morphological analysis were conducted. The Eeyarestatin I (EerI) inhibitor was employed to disrupt VCP involvement in the endoplasmic reticulum-associated protein degradation pathway (ERAD) in both pre- and post-incubation systems, with concentrations of 5 μM/mL and 25 μM/mL, respectively. We demonstrated for the first time that SDAV productively replicates in cultured primary neurons. VCP expression is markedly elevated during SDAV infection. The application of 5 μM/mL EerI in the post-treatment system yielded a statistically significant inhibition of the SDAV yield. It is likely that this modulates the efficacy of virion assembly by arresting viral proteins in the submembrane area.

Słowa kluczowe:
SDAV,VCP,primary neurons,virion assembly,ERAD,eeyarestatin I

Streszczenie:
In metal single crystals, the observed formation of deformation banding pattern has been explained by greater latent hardening of slip systems than their self-hardening, which promotes spatial segregation of plastic slips and lamination towards single-slip domains. Numerical studies focusing on the formation of deformation bands usually involved initial imperfections, boundary-induced heterogeneity, or the postulate of minimal global energy expenditure which additionally promoted non-uniformity of deformation. This article analyses the case when no such mechanism enforcing locally non-uniform deformation is implemented in the finite element (FE) method, while the global system of equations of incremental equilibrium is solved in a standard way. The new finding in this paper is that the deformation banding pattern can appear spontaneously in FE simulations of homogeneous single crystals even in the absence of any mechanism favouring deformation banding in the numerical code. This has been demonstrated in several examples in the small strain formalism using a plane-strain model in which the twelve fcc slip systems are reduced to three effective plastic slip mechanisms. Incremental slips are determined at the Gauss-point level either by incremental work minimization in the rate-independent case or by rate-dependent regularization. In the rate-independent approach, the trust-region algorithm is developed for the selection of active slip systems with the help of the augmented Lagrangian method. Conditions under which a banding pattern appears spontaneously or is suppressed are discussed. In particular, a critical rate sensitivity exponent is identified.

Słowa kluczowe:
Crystal plasticity, Small strain, Slip-system selection, Path instability, Microstructure formation, Finite element method

Streszczenie:
Hemoglobin (Hb) performs its physiological function within the erythrocyte. Extracellular Hb has prooxidative and proinflammatory properties and is therefore sequestered by haptoglobin and bound by the CD163 receptor on macrophages. In the present study, we demonstrate a novel process of Hb uptake by macrophages independent of haptoglobin and CD163. Unexpectedly, macrophages do not degrade the entire Hb, but instead transfer it to neighboring cells. We have shown that the phenomenon of Hb transfer from macrophages to other cells is mainly mediated by extracellular vesicles. In contrast to the canonical Hb degradation pathway by macrophages, Hb transfer has not been reported before. In addition, we have used the process of Hb transfer in anticancer therapy, where macrophages are loaded with a Hb-anticancer drug conjugate and act as cellular drug carriers. Both mouse and human macrophages loaded with Hb-monomethyl auristatin E (MMAE) effectively killed cancer cells when co-cultured in vitro.

Słowa kluczowe:
Hemoglobin,Macrophages,CD163,Extracellular vesicles,Monomethyl auristatin E

Streszczenie:
Spatially-resolved modeling of deformation twinning and its interaction with plastic slip is achieved by coupling the phase- field method and crystal plasticity theory. The intricate constitutive relations arising from this coupling render the resulting computational model prone to inefficiencies and lack of robustness. Accordingly, together with the inherent limitations of the phase-field method, these factors may impede the broad applicability of the model. In this paper, our recent phase-field model of coupled twinning and crystal plasticity is the subject of study. We delve into the incremental formulation and computational treatment of the model and run a thorough investigation into its computational performance. We focus specifically on evaluating the efficiency of the finite-element discretization employing various element types, and we examine the impact of mesh density. Since the micromorphic regularization is an important part of the finite-element implementation, the effect of the micromorphic regularization parameter is also studied.

Słowa kluczowe:
Deformation twinning, Microstructure, Phase-field method, Crystal plasticity, Finite element method

Streszczenie:
The presence and extent of metastatic disease in axillary lymph nodes (ALNs) in the setting of breast cancer (BC) are important factors for staging and therapy planning. The purpose of this study was to perform a multiparametric sonographic evaluation of ALNs to better differentiate between benign and metastatic nodes. Ninety-nine patients (mean age 54.1 y) with 103 BCs were included in this study, and 103 ALNs were examined sonographically. B-mode parameters, such as size in two dimensions, shape, cortical thickness and capsule outline, were obtained, followed by vascularity assessment via colour Doppler and microflow imaging and stiffness evaluation via shear wave elastography. Postoperative histopathological evaluation was the reference standard. In the statistical analysis, logistic regression and ROC analyses were conducted to search for feature patterns of both types of ALNs to evaluate the prediction qualities of the analysed variables and their combinations. For a cortex larger than 3 mm, without a circumscribed margin of the LN capsule and SWE (E max > 26 kPa), the AUC was 0.823. Multiparametric assessment, which combined conventional US, quantitative SWE and vascularity analysis, was superior to the single-parameter approach in the evaluation of ALNs.

Streszczenie:
Bone defects resulting from congenital anomalies and trauma pose significant clinical challenges for orthopedics surgeries, where bone tissue engineering (BTE) aims to address these challenges by repairing defects that fail to heal spontaneously. Despite numerous advances, BTE still faces several challenges, i.e., difficulties in detecting and tracking implanted cells, high costs, and regulatory approval hurdles. Biomaterials promise to revolutionize bone grafting procedures, heralding a new era of regenerative medicine and advancing patient outcomes worldwide. Specifically, novel bioactive biomaterials have been developed that promote cell adhesion, proliferation, and differentiation and have osteoconductive and osteoinductive characteristics, stimulating tissue regeneration and repair, particularly in complex skeletal defects caused by trauma, degeneration, and neoplasia. A wide array of biological therapeutics for bone regeneration have emerged, drawing from the diverse spectrum of gene therapy, immune cell interactions, and RNA molecules. This review will provide insights into the current state and potential of future strategies for bone regeneration.

Streszczenie:
Bone defects and fractures present significant clinical challenges, particularly in orthopedic and maxillofacial applications. While minor bone defects may be capable of healing naturally, those of a critical size necessitate intervention through the use of implants or grafts. The utilization of traditional methodologies, encompassing autografts and allografts, is constrained by several factors. These include the potential for donor site morbidity, the restricted availability of suitable donors, and the possibility of immune rejection. This has prompted extensive research in the field of bone tissue engineering to develop advanced synthetic and bio-derived materials that can support bone regeneration. The optimal bone substitute must achieve a balance between biocompatibility, bioresorbability, osteoconductivity, and osteoinductivity while simultaneously providing mechanical support during the healing process. Recent innovations include the utilization of three-dimensional printing, nanotechnology, and bioactive coatings to create scaffolds that mimic the structure of natural bone and enhance cell proliferation and differentiation. Notwithstanding the advancements above, challenges remain in optimizing the controlled release of growth factors and adapting materials to various clinical contexts. This review provides a comprehensive overview of the current advancements in bone substitute materials, focusing on their biological mechanisms, design considerations, and clinical applications. It explores the role of emerging technologies, such as additive manufacturing and stem cell-based therapies, in advancing the field. Future research highlights the need for multidisciplinary collaboration and rigorous testing to develop advanced bone graft substitutes, improving outcomes and quality of life for patients with complex defects.

Słowa kluczowe:
bone regeneration, fractures, bone grafts, bone substitutes, bone implants

Streszczenie:
There exists a growing discourse around the domination of Big Tech on the landscape of artificial intelligence (AI) research, yet our comprehension of this phenomenon remains cursory. This paper aims to broaden and deepen our understanding of Big Tech's reach and power within AI research. It highlights the dominance not merely in terms of sheer publication volume but rather in the propagation of new ideas or memes. Current studies often oversimplify the concept of influence to the share of affiliations in academic papers, typically sourced from limited databases such as arXiv or specific academic conferences.
The main goal of this paper is to unravel the specific nuances of such influence, determining which AI ideas are predominantly driven by Big Tech entities. By employing network and memetic analysis on AI-oriented paper abstracts and their citation network, we are able to grasp a deeper insight into this phenomenon. By utilizing two databases: OpenAlex and S2ORC, we are able to perform such analysis on a much bigger scale than previous attempts.
Our findings suggest that while Big Tech-affiliated papers are disproportionately more cited in some areas, the most cited papers are those affiliated with both Big Tech and Academia. Focusing on the most contagious memes, their attribution to specific affiliation groups (Big Tech, Academia, mixed affiliation) seems equally distributed between those three groups. This suggests that the notion of Big Tech domination over AI research is oversimplified in the discourse.

Słowa kluczowe:
Knowledge diffusion, Novelty, Affiliation influence, Big tech impact, Complex networks, Natural language processing

Streszczenie:
Background

Metal Laser Powder Bed Fusion Melting (LPBF-M) is considered economically viable and environmentally sustainable because of the possibility of reusing the residual powder feedstock leftover in the build chamber after a part build is completed. There is however limited information on the fatigue damage development of LPBF-M samples made from reused feedstock.
Objective

In this paper, the stainless steel 316 L (SS316L) powder feedstock was examined and characterised after 25 reuses, following which the fatigue damage development of material samples made from the reused powder was assessed.
Methods

The suitability of the powder to LPBF-M technology was evaluated by microstructural observations and measurements of Hall flow, apparent and tapped density as well as Carr’s Index and Hausner ratio. LPBF-M bar samples in three build orientations (Z – vertical, XY – horizontal, ZX – 45° from the build plate) were built for fatigue testing. They were then subjected to fatigue testing under load control using full tension and compression cyclic loading and stress asymmetry coefficient equal to -1 in the range of stress amplitude from ± 300 MPa to ± 500 MPa.
Results

Samples made from reused powder (25 times) in the LPBF-M process exhibited similar fatigue performance to fresh unused powder although a lower ductility for vertical samples was observed during tensile testing. Printing in horizontal (XY) and diagonal (ZX) directions, with reused powder, improved the service life of the SS316L alloy in comparison to the vertical (Z).
Conclusions

Over the 25 reuses of the powder feedstock there was no measurable difference in the flowability between the fresh (Hall Flow: 21.4 s/50 g) and reused powder (Hall Flow: 20.6 s/50 g). This confirms a uniform and stable powder feeding process during LPBF-M for both fresh and reused powder. The analysis of fatigue damage parameter, D, concluded cyclic plasticity and ratcheting to be the main mechanism of damage.

Słowa kluczowe:
SS316L ,Stainless steel,Fatigue ,Additive manufacturing,Laser Powder Bed Fusion Melting (LPBF-M)

Streszczenie:
In this paper, the effectiveness of the eddy current methodology for crack detection in MAR 247 nickel-based superalloy with aluminide coatings subjected to cyclic loading was investigated. The specimens were subjected to force-controlled fatigue tests under zero mean level, constant stress amplitude from 300 MPa to 600 MPa and a frequency of 20 Hz. During the fatigue, a particular level of damage was introduced into the material leading to the formation of microcracks. Subsequently, a new design of probe with a pot core was developed to limit magnetic flux leakage and directed it towards the surface under examination. The suitability of the new methodology was further confirmed as the specimens containing defects were successfully identified. The changes in probe resistance values registered for damaged specimens ranged approximately from 8 to 14%.

Słowa kluczowe:
Nickel alloys, Aluminide coating, Non-destructive testing, Eddy current testing

Streszczenie:
Concrete used in nuclear applications faces significant durability challenges due to degradation from radiation, thermal stresses, and chemical reactions. These issues highlight the critical need for impermeable concrete shields to prevent radioactive leaks and protect against harmful radiation. This study examines how concrete composition affects gas permeability and gamma radiation shielding properties. Three coarse aggregates—amphibolite (reference), magnetite, and serpentine—and two cement types (ordinary and slag) were tested, with concrete densities ranging from 2309 to 3538 kg/m3. Gas permeability was measured using a Cembureau-type constant head permeameter, and gamma shielding was assessed through the linear attenuation coefficient (µ) and half-value layer (HVL) at 137Cs decay energies. The results revealed significant variations in gas permeability and gamma ray shielding based on aggregate and cement type, with observable relationships between gas permeability, HVL, and concrete density. The results obtained from the presented research will contribute to increasing the safety, durability and cost-effectiveness of concrete constructions and maintenance of nuclear facilities.

Słowa kluczowe:
Heavyweight aggregate, Hydrogen-bearing aggregate, Shielding concrete, Gas permeability, Gamma ray attenuation, Microstructure, ITZ

Streszczenie:
The quality parameters of surface layers synthesised using electrospark alloying (ESA) technology were analysed in this paper. The main focus was on the influence of equipment energy parameters on structure formation, specifically the effect of discharge energy and productivity. Microstructural analysis of the modified surface of C40 steel after nitriding by ESA using a paste containing nitrogen compounds injected into the interelectrode gap was conducted. The layer structure for all studied ESA parameters includes three areas: the upper “white layer”, the diffusion zone below it, and the substrate. The roughness of the surface is Ra ∼ 0.9 μm at low discharge energy Wp = 0.13 J and Ra ∼ 6 μm at Wp = 3.4 J. The microhardness, continuity, and surface roughness of the layers varied with Wp. The influence of ESA productivity on the structure was studied. The thickness of the hardened layer and the diffusion zone, as well as the microhardness and continuity, are affected by reduced productivity. For the same discharge energy, the thickness of the hardened layer increases by 10-18% with a decrease in productivity compared to the classical mode.

Słowa kluczowe:
electrospark alloying, discharge energy, productivity, coating, structure

Streszczenie:
Bone repair and regeneration require physiological cues, including mechanical, electrical, and biochemical activity. Many biomaterials have been investigated as bioactive scaffolds with excellent electrical properties. Amongst biomaterials, piezoelectric materials (PMs) are gaining attention in biomedicine, power harvesting, biomedical devices, and structural health monitoring. PMs have unique properties, such as the ability to affect physiological movements and deliver electrical stimuli to damaged bone or cells without an external power source. The crucial bone property is its piezoelectricity. Bones can generate electrical charges and potential in response to mechanical stimuli, as they influence bone growth and regeneration. Piezoelectric materials respond to human microenvironment stimuli and are an important factor in bone regeneration and repair. This manuscript is an overview of the fundamentals of the materials generating the piezoelectric effect and their influence on bone repair and regeneration. This paper focuses on the state of the art of piezoelectric materials, such as polymers, ceramics, and composites, and their application in bone tissue engineering. We present important information from the point of view of bone tissue engineering. We highlight promising upcoming approaches and new generations of piezoelectric materials.

Słowa kluczowe:
piezoelectricity, scaffolds, smart scaffolds, PVDF, PLLA, PVDF-TRFE, collagen, keratin, tissue engineering, bone tissue engineering, smart medicine, regenerative medicine

Streszczenie:
Addressing critical tissue defects treatment remains a pressing challenge in medicine and bioengineering. Tissue engineering (TE) scaffolds, characterized by porous architectures suitable to cell growth, is a pivotal solution. Recent advances in additive techniques have revolutionized scaffold fabrication, enabling precise control over complex porous structures. This study conducts a comprehensive analysis of hierarchically ordered melt electrospun written (MEW) TE scaffolds, elucidating the relationships between fabrication parameters and their morphological and mechanical properties. Leveraging the phenomenon of melt jet deposit buckling, characteristic hierarchically ordered porous architectures were attained. The study explores the fabrication potential of hierarchically ordered porous MEW architectures across varied voltages, feed rates, and needle sizes. Morphometric parameters, including percent porosity, density of fiber intersections, and fiber diameter, were identified. It was revealed that for feed rates exceeding 20 mm/s, resultant fiber diameters were unaffected by voltage. However, increasing voltage leads to noticeable reduction of mesh stiffness due to the coiled fibers presence. Exceptions occur at the feed rate of 20 mm/s and for needle G24, where stiffness surpasses those of regular primary pattern, which could be attributed to increased number of fiber interconnections.

Słowa kluczowe:
MEW, Hierarchically ordered meshes, Coiled architectures, Entangled meshes

Streszczenie:
The global scarcity of drinking water is an emerging problem associated with increasing pollution with many chemicals from industry and rapid microbial growth in aquatic systems. Despite the wide availability of conventional water and wastewater treatment methods, many limitations and challenges exist to overcome. Applying technology based on microbubbles (MBs) and nano-bubbles (NBs) offers ecological, fast, and cost-effective water treatment. All due to the high stability and long lifetime of the bubbles in the water, high gas transfer efficiency, free radical generation capacity, and large specific surface areas with interface potential of generated bubbles. MBs and NBs-based technology are attractive solutions in various application areas to improve existing water and wastewater treatment processes including industrial processes. In this paper, recent progress in NBs and MBs technology in water purification and wastewater treatment along with fundamentals, application, challenges, and future research were comperhensively discussed.

Słowa kluczowe:
Nanobubbles, Microbubbles, MNB, Wastewater treatment, Water pollution utilization

Streszczenie:
NiTi exhibits an excellent wear resistance, which can be further enhanced by ion implantation. However, there are some limitations to the implantation effects: only a thin layer of about 100 nm can be created. In this paper, the effect of nitrogen ion implantation on the NiTi wear response is investigated. The different loads and durations of tests are taken into account to show that the implanted layer has the most beneficial effect only in a certain range of contact pressure. It was found that the wear volume changes in a nonlinear manner with respect to the load and sliding length, for both non- and implanted samples. For the latter, two distinct stages can be distinguished in the wear process: an initial stage characterized by a low wear-rate and a low coefficient of friction, and a second stage in which the wear-rate drastically increases. The duration of the first stage is longer for lower loads. This specific behavior is explained by differences in the hardness distribution, energy dissipation due to the normal load, and differences in the microstructure of the wear tracks. Our results show that the lifetime of NiTi can be improved by ion implantation, thus boding well for applications in harsh environments.

Słowa kluczowe:
ion implantation, NiTi shape memory alloy, sliding wear, pseudoelasticity, abrasion, dry friction, surface treatments

Streszczenie:
We present a nonlinear finite element analysis to investigate the buckling and post-buckling behaviour of functionally graded material (FGM) plates resting on the elastic foundation. The material properties are assumed to vary gradually across the thickness according to a power law distribution. The starting point of the investigation is the generalized third-order plate theory and the Vlasov model of elastic foundation having properties varying throughout the depth. The plates are subjected to bending to verify the formulation and compression loads including buckling and post-buckling analysis to investigate the influence of various parameters on the structural response. Key words: FGM plate, elastic foundation, post-buckling, nonlinear finite element analysis.

Słowa kluczowe:
FGM plate, elastic foundation, post-buckling, nonlinear finite element analysis.

Streszczenie:
In this work, the classical concept of symmetry limited to geometric objects (figures and solids), which originated from ancient Greece, has been extended to allow for symmetry studies in other types of objects.By introducing the concepts of limiting point groups and kinematic elements characteristic for a studied object, it was determined what types of symmetries are exhibited by an electric field and a magnetic field. It was established that in order for a phenomenon to occur, a characteristic symmetry of a medium must be consistent with the characteristic symmetry of the phenomenon occurring in it. It was also determined that the symmetry elements of the causes must be found in the symmetry of their effects.

Słowa kluczowe:
symmetry, dissymmetry, Curie limiting point groups, symmetry of causes and effects, symmetry of physical fields, characteristic symmetry of phenomenon, characteristic symmetry of medium

Streszczenie:
Poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP)-sodium thiocyanate (NaSCN) solid polymer electrolytes containing different weight ratios of ionic liquid (IL)—tributylmethylphosphonium iodide (TBMPI) were prepared using solution-cast approach. Electrochemical impedance data indicates that increasing ionic liquid into polymer electrolyte matrix increases ionic conductivity and the maximum value of ionic conductivity was obtained at 150 wt% TBMPI, having conductivity value of 8.3 × 10−5 S cm−1. The dielectric measurement supports our conductivity data. Ionic transference number measurement affirms this system to be predominantly ionic in nature, while electrochemical stability window (ESW) was found to be 3.4 V. Polarized optical microscopy (POM) along with differential scanning calorimetry (DSC) suggest suitability of TBMPI as plasticizer, while infrared spectroscopy (FTIR) confirms ion interaction, complexation, and composite nature. The thermogravimetric analysis (TGA) shows thermal stability of these ionic liquid-doped polymer electrolytes (ILDPEs). Using maximum conducting ILDPE, a sandwiched supercapacitor has been fabricated which shows stable performance as high as 228 Fg−1 using cyclic voltammetry (CV).

Słowa kluczowe:
capacitance, ionic conductivity, ionic liquid (IL), solid polymer electrolyte (SPE), supercapacitor (SC)

Streszczenie:
The study investigated the effect of the oxidation–reduction cycles on the structure and corrosion resistance of the Haynes 282 nickel superalloy at ambient and elevated temperatures. The comparative studies were performed on specimens produced by the Powder Bed Fusion-Laser Beam (PBF-LB) process and those in the as-received state. The microstructure of the PBF-LB specimens was studied using optical and scanning electron microscopy, whereas the chemical composition of the scale formed after isothermal oxidation in an air atmosphere at 750°C was analysed using energy-dispersive X-ray spectroscopy and X-ray Photoelectron Spectroscopy. The phase composition of the formed scale was determined by X-ray diffraction. Laboratory-induced hydrogen atmosphere was adopted through cathodic charging. A comparison of corrosion resistance was carried out on two types of Haynes 282 specimens, before and after the oxidation and cathodic charging processes. It was found that PBF-LB process could be effectively used to manufacture Haynes 282 nickel superalloy with low porosity and a fine crystalline microstructure. The low-porous, fine-crystalline microstructure of the tested specimens produced by the PBF-LB technique exhibited good resistance to electrochemical corrosion, slightly lower than wrought Haynes 282 nickel superalloy specimens.

Słowa kluczowe:
corrosion, DMLS, haynes 282 nickel superalloy, hydrogen, oxidation

Streszczenie:
Artificial intelligence and machine learning (ML) approaches have recently been getting much of researchers’ attention. The growing interest in these methods results from the fast development of machine learning algorithms in the last few years, especially artificial neural networks. In this review, we pay attention to the need and benefits that ML approaches can bring to tissue engineering (TE). We critically evaluate the possibilities of using the ML approaches in the tissue engineering field. We consider various paths of its utility in the TE, such as scaffold design, predicting the biological response to the scaffold, optimizing drug delivery approaches, supporting image analysis, and modeling scaffold in vivo performance. The current status of ML implementation is presented and supported by many study examples. On the other hand, we analyze the present difficulties and challenges in implementing ML approaches to tissue engineering, including the quality of published data, databases and repositories availability, the need for experiment and results publishing standardization, and ethical issues. Additionally, we assess the available natural language processing tools that could support TE research.

Słowa kluczowe:
ultrasound imaging,abdominal ultrasound,nonlinear propagation,tissue harmonic imaging,nonlinearity index

Streszczenie:
In this work, we explore the notions unextendible product basis and uncompletability for operators which remain positive under partial transpose. Then, we analyze their connections to the ensembles which are many-copy indistinguishable under local operations and classical communication (LOCC). We show that the orthogonal complement of any bipartite pure entangled state is spanned by product states which form a nonorthogonal unextendible product basis (nUPB) of maximum cardinality. This subspace has one to one correspondence with the maximum dimensional subspace where there is no orthonormal product basis. Due to these, the proof of indistinguishability of a class of ensembles under LOCC in many-copy scenario becomes simpler. Furthermore, it is now clear that there are several many-copy indistinguishable ensembles which are different construction-wise. But if we consider the technique of proving their indistinguishability property under LOCC, then, for many of them it can be done using the general notion of unextendible product basis. Explicit construction of the product states, forming nUPBs is shown. Thereafter, we introduce the notion of positive partial transpose uncompletability to unify different many-copy indistinguishable ensembles. We also report a class of multipartite many-copy indistinguishable ensembles for which local indistinguishability property increases with decreasing number of mixed states.

Słowa kluczowe:
Unextendibility, Uncompletability, Many-copy indistinguishability, LOCC, PPT-POVM

Streszczenie:
We consider the problem of existence and properties of pulse solutions to a system of equations modeling fast calcium waves in long cells. These waves have the speed up to 1000 μm/s. They propagate via the inflow of calcium ions from the extracellular space through the mechanically stimulated membrane channels. The channels open due to mechano-chemical interaction, in which stretching of the cell's membrane at a point opens the calcium channels at neighboring points due to the forces exerted by the actomyosin network. The existence of homoclinic solutions is based on the celebrated exchange lemma, which cannot be applied straightforwardly due to some specificities of the model equations.

Słowa kluczowe:
calcium signaling, exchange lemma, homoclinic traveling waves

Streszczenie:
Human Respiratory Syncytial Virus (hRSV), a prevalent respiratory pathogen affecting various age groups, can trigger prolonged and intense inflammation in humans. The severity and outcome of hRSV infection correlate with elevated levels of pro-inflammatory agents, yet the underlying reasons for this immune system overstimulation remain elusive. We focused on the impact of hRSV non-structural proteins, NS1 and NS2, on immune response within epithelial cells. Available data indicates that these proteins impair the interferon pathway. We reinforce that NS1 and NS2 induce heightened secretion of the pro-inflammatory cytokines IL-6 and CXCL8. We also indicate that hRSV non-structural proteins provoke differential gene expression of human host FosB and long non-coding RNAs (MALAT1, RP11-510N19.5). It suggests an impact of NS molecules beyond IFN pathways. Thus, new light is shed on the interplay between hRSV and host cells, uncovering unexplored avenues of viral interference, especially the NS2 role in cytokine expression and immune modulation.

Słowa kluczowe:
Human respiratory syncytial virus, Non-structural protein 1, Non-structural protein 2, Cytokines, MALAT1 long non-coding RNA

Streszczenie:
Mean-field modeling based on the Eshelby inclusion problem poses some difficulties when the non-linear Maxwell-type constitutive law is used for elasto–viscoplasticity. One difficulty is that this behavior involves different orders of time differentiation, which leads a long-term memory effect. One of the possible solutions to this problem is the additive interaction law. Generally, mean field models solely use the mean values of stress and strain fields per phase, while variational approaches consider the second moments of stresses and strains. It is seen that the latter approach improves model predictions allowing to account for stress fluctuation within the phases. However, the complexity of the variational formulations still makes them difficult to apply in the large scale finite element calculations and for non-proportional loadings. Thus, there is a need to include the second moments within homogenization models based on the additive interaction law. In the present study, the incorporation of the second moments of stresses into the formulation of the additive Mori–Tanaka model of two-phase elastic–viscoplastic material is discussed. A modified tangent linearization of the viscoplastic law is proposed, while the Hill–Mandel’s lemma is used to track the evolution of second moments of stresses. To study the model performance and efficiency, the results are compared to the full-field numerical calculations and predictions of other models available in the literature. Very good performance of the modified tangent linearization is demonstrated from these benchmarks for both monotonic and non monotonic loading responses.

Słowa kluczowe:
Homogenization , Elasto-viscoplasticity, Non linear composites, Modified tangent linearization, Additive interaction law

Streszczenie:
Advanced flexible ionotronic devices have found excellent applications in the next generation of electronic skin (e-skin) development for smart wearables, robotics, and prosthesis. In this work, we developed transparent ionotronic-based flexible electrochemical capacitors using gel electrolytes and indium tin oxide (ITO) based transparent flexible electrodes. Different gel electrolytes were prepared using various salts, including NaCl, KCl, and LiCl in a 1:1 ratio with a polyvinyl alcohol (PVA) solution and compared its electrochemical performances. The interaction between gel electrolytes and ITO electrodes was investigated through the development of transparent electrochemical capacitors (TEC). The stable and consistent supply of ions was provided by the gel, which is essential for the charge storage and discharge within the TEC. The total charge contribution of the developed TECs is found from the diffusion-controlled mechanism and is measured to be 4.59 mC cm−2 for a LiCl/PVA-based gel. The prepared TEC with LiCl/PVA gel electrolyte exhibited a specific capacitance of 6.61 mF cm−2 at 10 μA cm−2. The prepared electrolyte shows a transparency of 99% at 550 nm and the fabricated TEC using LiCl/PVA gel exhibited a direct bandgap of 5.34 eV. The primary benefits of such ionotronic-based TEC development point to its potential future applications in the manufacturing of transparent batteries, electrochromic energy storage devices, ionotronic-based sensors, and photoelectrochemical energy storage devices.

Streszczenie:
Mobile devices such as smartphones, tablets or similar devices are becoming increasingly important as measurement devices in forestry due to their advanced sensors, including RGB cameras and LiDAR systems. This review examines the current state of applications of mobile devices for measuring biometric characteristics of individual trees and presents technologies, applications, measurement accuracy and implementation barriers. Passive sensors, such as RGB cameras have proven their potential for 3D reconstruction and analysing point clouds that improve single treelevel information collection. Active sensors with LiDAR-equipped smartphones provide precise quantitative measurements but are limited by specific hardware requirements. The combination of passive and active sensing techniques has shown significant potential for comprehensive data collection. The methods of data collection, both physical and digital, significantly affect the accuracy and reproducibility of measurements. Applications such as ForestScanner and TRESTIMATM have automated the measurement of tree characteristics and simplified data collection. However, environmental conditions and sensor limitations pose a challenge. There are also computational obstacles, as many methods require significant post-processing. The review highlights the advances in mobile device-based forestry applications and emphasizes the need for standardized protocols and cross-device benchmarking. Future research should focus on developing robust algorithms and cost-effective solutions to improve measurement accuracy and accessibility. While mobile devices offer significant potential for forest surveying, overcoming the above-mentioned challenges is critical to optimizing their application in forest management and protection.

Słowa kluczowe:
mobile device, tree attributes , LiDAR, Photogrammetry

Streszczenie:
We employ pDyn (derived from ‘‘pandemics dynamics’’), an agent-based epidemiological model, to forecast the fourth wave of the SARS-CoV-2 epidemic, primarily driven by the Delta variant, in Polish society. The model captures spatiotemporal dynamics of the epidemic spread, predicting disease-related states based on pathogen properties and behavioral factors. We assess pDyn’s validity, encompassing pathogen variant succession, immunization level, and the proportion of vaccinated among confirmed cases. We evaluate its predictive capacity for pandemic dynamics, including wave peak timing, magnitude, and duration for confirmed cases, hospitalizations, ICU admissions, and deaths, nationally and regionally in Poland. Validation involves comparing pDyn’s estimates with real-world data (excluding data used for calibration) to evaluate whether pDyn accurately reproduced the epidemic dynamics up to the simulation time. To assess the accuracy of pDyn’s predictions, we compared simulation results with real-world data acquired after the simulation date. The findings affirm pDyn’s accuracy in forecasting and enhancing our understanding of epidemic mechanisms.

Słowa kluczowe:
Epidemic dynamics , Epidemiology, Agent-based model, COVID-19

Streszczenie:
In this study, we introduce ‘‘instance loss functions’’, a new family of loss functions designed to enhance the
training of neural networks in the instance-level segmentation and detection of objects in biomedical image
data, particularly those of varied numbers and sizes. Intended to be utilized conjointly with traditional loss
functions, these proposed functions, prioritize object instances over pixel-by-pixel comparisons. The specific
functions, the instance segmentation loss (instance), the instance center loss (center), the false instance rate
loss (false), and the instance proximity loss (proximity), serve distinct purposes. Specifically, instance improves
instance-wise segmentation quality, center enhances segmentation quality of small instances, false minimizes
the rate of false and missed detections across varied instance sizes, and proximity improves detection quality
by pulling predicted instances towards the ground truth instances. Through the task of segmenting white
matter hyperintensities (WMH) in brain MRI, we benchmarked our proposed instance loss functions, both
individually and in combination via an ensemble inference models approach, against traditional pixel-level
loss functions. Data were sourced from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and the
WMH Segmentation Challenge datasets, which exhibit significant variation in WMH instance sizes. Empirical
evaluations demonstrate that combining two instance-level loss functions through ensemble inference models
outperforms models using other loss function on both the ADNI and WMH Segmentation Challenge datasets for
the segmentation and detection of WMH instances. Further, applying these functions to the segmentation of
nuclei in histopathology images demonstrated their effectiveness and generalizability beyond WMH, improving
performance even in contexts with less severe instance imbalance.

Słowa kluczowe:
Instance-level segmentation loss, Instance-level detection loss, White matter hyperintensities, Brain lesions

Streszczenie:
This communication presents a comprehensive investigation into the impact of mixing on the synthesis of water-in-water Pickering emulsions. The approach employs commercial-grade oppositely charged nanoparticles within two distinct fluid phases, facilitating self-assembly and the formation of aggregates with variable sizes and compositions. Enhanced interfacial area, achieved through aggregate adsorption at the interface, elevates the Gibbs detachment energy of particles between the two aqueous phases, leading to stable emulsion formation. We further explore the effect of various mixing devices, including high-pressure and sonic wave mixing. Our findings reveal that mixing within the aqueous phase critically influences emulsion size, with sonicator-assisted mixing producing smaller droplets than homogenizer mixing. Both devices yield poly-dispersed droplet size distributions. Interestingly, the droplet size correlates well with the Hinze scale (hd), and the Kolmogorov length scale (ld) exhibits good correspondence within a specific operating range. The proposed method introduces a streamlined, one-step synthesis process for easy preparation, demonstrating excellent stability for a minimum of 30 days. This study pioneers the investigation of mixing effects within an aqueous two-phase system utilizing a Pickering emulsion template.

Streszczenie:
The synthesis of magnetically-active nickel-yttrium oxide (Ni-Y2O3) nanocomposite particles is described in this work. The investigated material is produced with a modified ultrasound spray pyrolysis (USP) device which differs from a common USP setup in terms of use of three independently heating zones. They provide a direct feed of H2 to the second reaction zone and allow controlling the formation of the nanocomposite particles and facilitating their post-reaction stabilization with polyvinylpyrrolidone (PVP). According to the morphological and structural studies, the Ni-Y2O3 material takes a form of nanoparticles whose sizes are not homogeneously distributed as well as shapes are not smooth due to the successful formation of composite material with two interpenetrating phases. Moreover, the organic layer is detected on the surface of the nanoparticles which confirms the presence of PVP stabilizer. The magnetic investigations confirm that the Ni-Y2O3 nanocomposite reveals a spin glass-like behavior in which a collective freezing of magnetic moments might occur due to the interparticle interactions between Ni nanocrystallites presented in the sample.

Streszczenie:
The dynamics of groups of non-touching particles settling under gravity in a crowded fluid medium are studied at the zero Reynolds number. It is assumed that the fluid velocity satisfies the Brinkman–Debye–Büche equations, and the particle dynamics are described in terms of the point-force model. The systems of particles at vertices of two or four horizontal regular polygons are considered that in the Stokes flow for a very long time do not destabilize, i.e., all the particles stay close to each other, performing periodic or quasiperiodic motions. It is known that such motions, as invariant manifolds, are essential for groups of particles at random initial positions to survive for a very long time and not destabilize. This work demonstrates that when the medium permeability is decreased, periodic motions cease to exist, and groups of particles split into smaller subgroups, moving away from each other. This mechanism seems to facilitate particle transport in a permeable medium.

Streszczenie:
Non-uniform distributions of various biological factors can be essential for tissue growth control, morphogenesis or tumor growth. The first model describing the emergence of such distributions was suggested by A. Turing for the explanation of cell differentiation in a growing embryo. In this model, diffusion-driven instability of the homogeneous in space solution appears due to the interaction of two or more morphogens described by a reaction–diffusion system of equations. In this work we suggest another mechanism of the emergence of spatial distributions in biological tissues based on local cell communication and global inhibition, and described by a nonlocal reaction–diffusion equation. Instability of the homogeneous in space solution leads to the emergence of stationary pulses and not of periodic solutions as in the case of Turing instability.

Słowa kluczowe:
Nonlocal reaction–diffusion equation, Instability, Stationary pulses, Biological models

Streszczenie:
This work presents a synthesis of iron nanochains through magnetic-field-induced reduction reaction performed with sodium borohydride in water, ethanol and isopropanol. After their preparation, the nanomaterials obtained in three different processes are washed several times in ethanol and acetone to remove side-products. The performed cleaning step is very sufficient for water-based synthesis of iron nanochains. In contrary, the nanostructures obtained in ethanol and isopropanol contain a significant amount of sodium chlorides which is hard to dispose. Moreover, the use of ethanol and isopropanol solvents causes the reduction of nanochains’ diameters. Both the presence of sodium chlorides and the reduction of diameter size result in the decrease of saturation magnetization of iron nanochains and the increase of their coercivities.

Słowa kluczowe:
One-dimensional nanostructures, Iron nanochains, Magnetic materials, Magnetic-field-induced synthesis

Streszczenie:
Recently, there has been a surge of interest in developing new types of photothermal materials driven by the ongoing demand for efficient energy conversion, environmental concerns, and the need for sustainable solutions. However, many existing photothermal materials face limitations such as high production costs or narrow absorption bands, hindering their widespread application. In response to these challenges, researchers have redirected their focus toward harnessing the untapped potential of organic waste-derived and bioderived materials. These materials, with photothermal properties derived from their intrinsic composition or transformative processes, offer a sustainable and cost-effective alternative. This review provides an extended categorization of organic waste-derived and bioderived materials based on their origin. Additionally, we investigate the mechanisms underlying the photothermal properties of these materials. Key findings highlight their high photothermal efficiency and versatility in applications such as water and energy harvesting, desalination, biomedical applications, deicing, waste treatment, and environmental remediation. Through their versatile utilization, they demonstrate immense potential in fostering sustainability and support the transition toward a greener and more resilient future. The authors’ perspective on the challenges and potentials of platforms based on these materials is also included, highlighting their immense potential for real-world implementation.

Słowa kluczowe:
photothermal materials, organic waste valorization, bioderived materials

Streszczenie:
The paper presents an attempt to assess the microstructure and mechanical properties by means of the magnetic Barkhausen noise (MBN) method. The experimental program was supplemented by metallographic examinations and hardness tests. It has been concluded that the MBN method can be used for non-destructive characterization of both single and two-phase steels used in the automotive industry. It was also found that the microstructure of steel can be distinguished using the shape of BN envelope and two magnetic parameters: Ubpp1 and Ug1. On the other hand, the hardness and ultimate tensile strength are described successfully by the Ug1/Ubpp1 parameter.

Słowa kluczowe:
microstructure, mechanical properties, Barkhausen noise, non-destructive method

Streszczenie:
Vehicle–road coupled system is inherently time–varying, and its responses are traditionally calculated using time–domain methods which involves significant computational effort. Aiming to improve the efficiency of response calculation for the coupled system, this paper proposes a fast calculation method in frequency domain, based on the newly developed moving frequency response function (FRF). Firstly, considering the vibration characteristics of an infinitely long road, the road response is straightforwardly expressed using the road impulse response function (IRF). Subsequently, the concept of the road moving IRF is proposed and derived with respect to the moving observation points. The moving FRF is then obtained by applying Fourier transform, which allows the responses of the road moving observation points to be established in frequency domain for fast calculation under moving loads. Furthermore, by analyzing the vehicle–road coupled vibrations, based on the vehicle FRF and road moving FRF, a formula for the vehicle–road coupling force is derived in frequency domain, along with an expression for the responses at the vehicle–road contact points. Finally, the approach is illustrated in numerical simulations of vehicle–road coupled systems, and its computational efficiency and accuracy are verified through comparison with currently popular methods.

Słowa kluczowe:
vehicle-road coupled vibration, frequency domain, frequency response function, impulse response function, numerical simulations

Streszczenie:
This paper discusses the science of material effort from the historical viewpoint. Two gen eral scientific tools: the geometrical descriptive method of Mohr, and the energetic method of Huber are compared and evaluated from the very beginning. Three appropriate stress invariants are taken into account: stress intensity, stress triaxiality and stress shearness. Es pecially, much attention is devoted to explanation of the stress shearness invariant, which aims at describing the Lode parameter in a more analytical manner. Two different tools of finding a proper yield surface which contains the above mentioned three stress invariants are discussed in the literature perspective. In particular, the three-parameter yield surface, called the Burzyński-Pęcherski hypothesis is researched and explained from this new of point view.

Słowa kluczowe:
Tresca-Mohr hypothesi, Beltrami-Huber, Mises, Burzyński Hypothesis, Lode parameter

Streszczenie:
The superposition of causal orders shows promise in various quantum technologies. However, the fragility of quantum systems arising from environmental interactions, leading to dissipative behavior and irreversibility, demands a deeper understanding of the possible instabilities in the coherent control of causal orders. In this work, we employ a collisional model to investigate the impact of an open control system on the generation of interference between two causal orders. We present the environmental instabilities for the switch of two arbitrary quantum operations and examine the influence of environmental temperature on each potential outcome of control post-selection. Additionally, we explore how environmental instabilities affect protocol performance, including switching between mutually unbiased measurement observables and refrigeration powered by causal order superposition, providing insights into broader implications.

Streszczenie:
The paper examines the low-frequency reverberation sound field in coupled-room systems. In theoretical model, the modal expansion of sound pressure was applied, while in numerical procedure, the discrete Hilbert transform was used to determine the amplitude of decaying sound. Computer simulations were performed for a room system consisting of two connected rectangular rooms. Eigenfunctions and eigenfrequencies of this system were determined by the finite element method. Simulation results showed that for the hard-walled room system the sound decay is almost exponential for frequencies of modes localized in one of the subrooms. Acoustical treatment of the ceiling significantly reduced reverberation. However, due to beating effects and modal overlap, a large irregularity of sound decay curves has occurred. This makes it difficult to correctly qualify the sound decay, because in this case it is practically impossible to characterize the reverberation process with only one or at most two decay times.

Słowa kluczowe:
room acoustics, coupled rooms, reverberant sound field, mode localization, sound decay

Streszczenie:
The long-term stability of alignment precision of microelectromechanical system accelerometers was evaluated. Four commercial biaxial accelerometers (two ADXL 202E and two ADXL 203 accelerometers by Analog Devices Inc.) were tested over a period of 20 and 15 years, respectively. The experimental studies were performed using a custom computer-controlled test rig and employing gravitational acceleration as the reference. Considerable changes in the existing misalignments were observed. It was found that not only misalignments between the sensitive axes changed over time, but due to some micro-movements within the mounting of the printed circuit board with the accelerometer chip, misalignments of the sensitive axes with respect to the mounting datum changed as well. Even though no bigger than 0.6°, the observed misalignments may considerably influence the accelerometer performance, especially in the case of tilt measurements. Some ways of increasing the considered long-term stability of printed circuit board mounting are proposed.

Słowa kluczowe:
stability, aging, microelectromechanical systems (MEMS), misalignment

Streszczenie:
Introduction: Cognitive impairment (CI) is common in both end-stage kidney disease (ESKD) and alcohol-related liver cirrhosis. The aim of this study was to assess the prevalence and patterns of CI in patients awaiting kidney and liver transplantation, and to identify its determinants.

Methods: In this cross-sectional, prospective study, 31 consecutive patients with ESKD and 31 consecutive patients with alcohol-related liver cirrhosis, all currently on transplant waiting lists, were screened for cognitive decline using the Addenbrooke's Cognitive Examination. Medical history, demographics, and laboratory test results were also collected.

Results: The prevalence of CI among patients with ESKD and alcohol-related liver cirrhosis was 26% and 90%, respectively. In both groups, memory was the most affected cognitive domain, along with verbal fluency in patients with ESKD, and visuospatial abilities in patients with alcoholic cirrhosis. The most statistically significant increase in the prevalence of CI was found in patients with lower educational attainment, in both alcohol-related liver cirrhosis and ESKD populations as well as in older patients with alcoholic cirrhosis. Furthermore, better cognitive functioning in ESKD patients was associated with higher levels of total lymphocyte count and alanine transaminase (ALT), and in alcohol-related liver cirrhosis patients with higher levels of ALT and aspartate transaminase. A nonsignificant trend toward lower memory domain scores was also observed with increasing ammonia levels and increasing severity of liver disease (higher Child-Pugh scores). Finally, suboptimal performance on the screening test was correlated with the severity of liver disease as assessed by the Model for End-Stage Liver Disease Sodium (MELD-Na), but not at the statistically significant level.

Conclusions: The prevalence of CI, especially in patients with alcohol-related liver cirrhosis, is high and can be a significant clinical problem, negatively affecting the transplantation process. Routine screening tests in this group would contribute to the implementation of appropriate management, such as rehabilitation program or psychosocial treatments and facilitate the provision of specialized health care.

Słowa kluczowe:
cognitive impairment, end‐stage kidney disease, end‐stage liver disease

Streszczenie:
The increasing groundwater pollution resulting from industrial dyes and pharmaceutical products, which come from various sources, requires urgent attention to implement effective remediation measures. We demonstrate that the rough particles studded with platinum (Pt) nanoparticles can be fabricated at room temperature straightforwardly and in a single step. These rough particles displayed a good catalytic power (100% removal efficiency) against a model industrial dye (methylene blue) and pharmaceutical residue (tetracycline) within a reasonable time scale. Characterization techniques such as X-ray diffraction (XRD), atomic force microscopy (AFM), and field emission scanning electron microscopy (FESEM) confirmed the uniform deposition of Pt nanoparticles on the surface of polystyrene particles, forming dense islands and the roughened surface. Further, we investigated the influence of particle size, concentration, and contact patterns on the performance of rough catalytic particles. The semi-batch conditions favoured the complete decomposition of tetracycline within 40 min, but the batch-wise operation offered a good contacting pattern for methylene blue, yielding a maximal output within 10 min. The kinetics of the heterogeneous catalytic process modelled by Langmuir-Hinshelwood kinetics (r = kKC/1 + KC) predicts that the given methylene blue decomposition reaction induced by the rough particles follows the pseudo-first-order kinetics. The rate constants for the reaction catalyzed by 0.6 and 1.0 m-sized rough particles are 0.048 and 0.032 min, respectively. Furthermore, we established the proof-of-concept using magnetically responsive nanoparticles for real-time applications, including decontamination and recovery of catalyst particles via an externally applied magnetic field in one cycle. Our proposed method helps achieve a near-100% degrading efficiency within 10 to 40 min at minimal catalytic particle concentration, i.e., 200 ppm. Since we can turn the rough particles into super-paramagnetic, we can recover and reuse them for several wastewater treatment cycles without incurring running costs.

Słowa kluczowe:
Polystyrene (PS), Iron Oxide (IO), Plat- inum nanoparticles, Rough particles, Magnetically- responsive nanoparticles, Methylene blue, Tetracy- cline, Environmental remediation

Streszczenie:
With the rapid development and commercial interest in the organ-on-a-chip (OoC) field, there is a need for materials addressing key experimental demands and enabling both prototyping and large-scale production. Here, we utilized the gas-permeable, thermoplastic material polymethylpentene (PMP). Three methods were tested to prototype transparent PMP films suitable for transmission light microscopy: hot-press molding, extrusion, and polishing of a commercial, hazy extruded film. The transparent films (thickness 20, 125, 133, 356, and 653 µm) were assembled as the cell-adhering layer in sealed culture chamber devices, to assess resulting oxygen concentration after 4 days of A549 cell culture (cancerous lung epithelial cells). Oxygen concentrations stabilized between 15.6% and 11.6%, where the thicker the film, the lower the oxygen concentration. Cell adherence, proliferation, and viability were comparable to glass for all PMP films (coated with poly-L-lysine), and transparency was adequate for transmission light microscopy of adherent cells. Hot-press molding was concluded as the preferred film prototyping method, due to excellent and reproducible film transparency, the possibility to easily vary film thickness, and the equipment being commonly available. The molecular orientation in the PMP films was characterized by IR dichroism. As expected, the extruded films showed clear orientation, but a novel result was that hot-press molding may also induce some orientation. It has been reported that orientation affects the permeability, but with the films in this study, we conclude that the orientation is not a critical factor. With the obtained results, we find it likely that OoC models with relevant in vivo oxygen concentrations may be facilitated by PMP. Combined with established large-scale production methods for thermoplastics, we foresee a useful role for PMP within the OoC field.

Słowa kluczowe:
polymethylpentene, gas permeability, organ-on-a-chip, prototyping thermoplastics, microfluidic device, microscopy

Streszczenie:
The objective of this examination was to test the aging resistance of the aluminous porcelain material C 130 type, when exposed to direct current (DC) high voltage. Long-term exposure to high DC voltages can potentially lead to various negative effects, in particular ionic current development in the porcelain material. This process may reduce the mechanical strength and, consequently, cause a failure. This problem has been noticed in the case of glass disc insulators. The samples were examined using the 3-point bending test, ultrasonic and microscopic analysis. No recordable degradation effects were found. Long-term impact of DC high voltage did not reduce the mechanical parameters or change the microstructure of the porcelain material.

Słowa kluczowe:
DC high voltage, aluminous porcelain C 130, 3-point bending test, mechanical strength

Streszczenie:
The application of the acoustic emission (AE) method for the detection and recording of partial discharges (PD) occurring in a medium voltage switchgear model was presented in this paper. The results of AE measurements were presented in the form of spectrograms. The acoustic emission effect occurred when the applied voltage level reached values from 10 kV to 30 kV. The authors used devices and probes EA to record PD using the acoustic method. The presented equipment can also be intended for industrial applications. The original accomplishment of the presented work is the achievement of successful and repeatable results of partial discharge measurements using the acoustic method.

Słowa kluczowe:
Partial Discharges (PD), Acoustic Emission (AE), Registration of Acoustic Emission signals

Streszczenie:
Hybrid-density-functional-theory calculations are used to evaluate the structural and electronic properties and formation energies of N-doped β-Ga2O3. Altogether, eleven interstitial (Ni) and three substitutional (NOI,II,III) impurity positions are investigated. Since direct evidence of N2 formation following the annealing of Ga2O3 and ZnO matrixes is revealed experimentally earlier, four complexes comprising two N atoms are also considered. It is determined that substitutional nitrogen defects act as deep acceptors, whereas the interstitial defects and N2-like complexes act as deep donors. Under Ga-rich growth conditions, substitutional nitrogen defects exhibit lower formation energies, with NOII defects being the most favorable. Under Ga-poor conditions, interstitial defects are more energetically desirable for a wide Fermi energy range, with Ni9 defect being the most favorable. The formation of the N2-like considered here at solely interstitial positions is energetically very expensive regardless of growth conditions. Finally, the Ni9–NOI complex is the most desirable one under Ga-rich conditions. This knowledge can serve as a basis for the development of optimal doping strategies, potentially leading to improved performance in future β-Ga2O3-based electronic devices.

Streszczenie:
This paper is devoted to multiscale modeling of cement composites. The need for this approach is due to the heterogeneous complex internal structure of the composite. A multiscale model of the composite was built and the results of computer simulations for the adopted parameters of the microstructure of the composite were presented, enabling a more detailed analysis of its mechanical and structural properties.

Słowa kluczowe:
multiscale modeling,analysis of heterogeneity of cement composite structure,computer simulations

Streszczenie:
Thermoresponsive hydrogels provide a platform for sustained delivery of nanoparticles via nose-to-brain route by resisting mucociliary clearance to the enhanced mean residence time (MRT) of the formulation in the nasal cavity overcoming neurotoxicity induced by uncontrolled delivery of nanoparticles and accumulation in the brain when delivered alone. The reported study presents the synthesis of pullulan (PLN) based nanoparticles (PNP-EHBr) loaded with eletriptan hydrobromide (EHBr) via ionic gelation method having size between 26.65 nm and 29.59 nm after stability studies of 4 h incubation with an average zeta potential of 22.5 ± 0.1 mV and entrapment efficiency of 92.048%. F-127/F-68 based hyaluronic acid-co-pectin hydrogels of EHBr-loaded PLN nanoparticles thermoresponsive hydrogels (HAP-PNP-EHBr/T-Hg) were characterized via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermal analysis (TGA/DSC), and scanning electron microscopy and evaluated for their gelation time, gelation temperature, gel strength, cloud point, sol–gel fraction, ex-vivo permeation, etc. HAP-PNP-EHBr/T-Hg showed drug release in a controlled pattern in both phosphate-buffered saline (PBS) and simulated nasal fluid (SNF) i.e., 90.12 and 87.99, respectively, over 48 h, while PNP-EHBR, 99.44 and 97.53 in PBS and SNF, respectively, over 8 h. The controlled release and absorption of EHBr from HAP-PNP-EHBr/T-Hg and PNP-EHBr was estimated by an in-vivo pharmacokinetic study using high-performance liquid chromatography, MRT and area under the curve (AUC) were increased up to 11.337 ± 0.32 h and 3,104.73 ± 75.841 ng/mL*h, 11.088 ± 0.177 h and 3,906.64 ± 152.86 ng/mL*h in brain and blood respectively after IN administration. This work demonstrates the successful synthesis of a twofold drug delivery system with PLN-based nanoparticles (PNP-EHBr) loaded with EHBr laden F-127/F-68 based hyaluronic acid-co-pectin hydrogels (HAP-PNP-EHBr/T-Hg).

Słowa kluczowe:
Biodegradable polymers, controlled delivery, nose-to-brain delivery, polymeric nanoparticles, self-assembling micelles, thermoresponsive hydrogels

Streszczenie:
Background. The coronavirus disease 2019 (COVID-19) pandemic has significantly accelerated the development and use of new healthcare technologies. While younger individuals may have been able to quickly embrace virtual advancements, older adults may still have different needs in terms of health communication.

Objectives. To identify areas of interest and preferred sources of information related to the COVID-19 pandemic among older adults and to verify their eHealth competencies.

Materials and methods. The study was conducted between February 2022 and July 2022. It included listeners from the University of the Third Age (U3A) and younger students. Both groups received information about the HealthBuddy+ chatbot, a questionnaire that addressed respondents’ interests about COVID-19, and the PL-eHEALS (eHealth Literacy Scale) questionnaire to measure their eHealth competencies.

Results. There were 573 participants in the study (U3A listeners – 303 participants, median age: 73 years (interquartile range (IQR): 69–77); young adult students – 270, median age: 24 years (IQR: 23–24). The primary source of information about COVID-19 for older adults was television (84.5%), and for younger adults, internet (84.4%). Among the older adults, only 17% ever interacted with a chatbot (younger adults – 78% respectively), and 19% considered it a trustworthy source of information on COVID-19 compared to 79% of younger respondents. Older adults and younger adults in our study were most interested in COVID-19 treatment methods (45.5% and 69.3%, respectively), symptoms of the disease (36.6% and 35.2%, respectively) and chronic diseases coexisting with COVID-19 (35.0% and 51.5%, respectively). However, their eHealth competencies were generally low (median (Me): 34; IQR: 30–39) compared to younger adults (Me: 42; IQR: 40–47).

Conclusions. Health education for older adults should be appropriately tailored to their current needs and differentiated. The level of eHealth competencies of older adults suggests that much work remains to narrow the gap between the eHealth competencies of the younger and older generations.

Słowa kluczowe:
health education,older adults,information seeking,COVID-19

Streszczenie:
Przedstawiono wyniki oceny diagnostycznej posadzki przemysłowej przy wykorzystaniu metodyki ilościowej oceny mikrostruktury betonu. Objawy uszkodzeń obejmowały pylenie powierzchniowe i delaminację warstwy utwardzonej. Przeprowadzono analizę petrograficzną składu betonu w próbkach-odwiertach. Zaobserwowano nadmierne napowietrzenie betonu, gromadzenie się porów powietrznych i występowanie ukierunkowanych spękań, miejscową zmienność składu fazowego produktów hydratacji cementu, w tym występowanie obszarów o intensywnej karbonatyzacji, co wpływało na przedwczesne uszkodzenia powierzchniowe.
Diagnostic assessment of industrial floor using the methodology of quantitative evaluation of concrete microstructure is presented. Symptoms of damage included surface dusting and delamination of the top layer. A petrographic analysis of the concrete composition in core specimens was carried out. Excessive air content, accumulation of air voids and the occurrence of oriented cracks, local variability of the phase composition of cement hydration products, including the occurrence of carbonated areas were observed and associated with the premature surface damage.

Słowa kluczowe:
delaminacja, mikroskopia ilościowa, porowatość, posadzki betonowe, utwardzenie powierzchniowe, delamination, quantitative microscopy, porosity, concrete floors, surface hardening

Streszczenie:
Research on the durability of structural concrete requires careful selection of aggregates, particularly considering their reactivity to alkali-silica reaction (ASR). The Miniature Concrete Prism Test (MCPT) allows for shortened testing time
and eliminates the need for aggregate crushing, making it a practical alternative to other methods. The aim of the research is to evaluate the reactivity of aggregate mixtures with varying mineral compositions. Research results confirm
the significant impact of fine aggregates on concrete expansion in the MCPT method in NaOH solution at 60°C. The observed expansion correlates with a reduction in concrete’s elastic modulus.
Badania nad trwałością betonu konstrukcyjnego wymagają starannej selekcji kruszyw, szczególnie uwzględniającej ich reaktywność na reakcję alkalia-krzemionka (ASR). Metoda Miniature Concrete Prism Test (MCPT) pozwala na skrócenie
czasu badania i eliminację konieczności rozdrabniania kruszywa, co czyni ją praktyczną alternatywą dla innych metod. Celem badań jest ocena reaktywności mieszaniny kruszyw o zróżnicowanym składzie mineralnym. Wyniki badań potwierdzają
znaczący wpływ kruszywa drobnego na ekspansję betonu w metodzie MCPT w roztworze NaOH w temp. 60°C. Obserwowana ekspansja koreluje z redukcją modułu sprężystości betonu.

Słowa kluczowe:
alkali-silica reaction (ASR), concrete expansion, MCPT method, fine aggregate, durability, reakcja alkalia-krzemionka (ASR), ekspansja betonu, metoda MCPT, kruszywo drobne, trwałość

Streszczenie:
Context
SARS-CoV-2, responsible for COVID-19, has led to over 500 million infections and more than 6 million deaths globally. There have been limited effective treatments available. The study aims to find a drug that can prevent the virus from entering host cells by targeting specific sites on the virus’s spike protein.

Method
We examined 13,397 compounds from the Malaria Box library against two specific sites on the spike protein: the receptor-binding domain (RBD) and a predicted cryptic pocket. Using virtual screening, molecular docking, molecular dynamics, and MMPBSA techniques, they evaluated the stability of two compounds. TCMDC-124223 showed high stability and binding energy in the RBD, while TCMDC-133766 had better binding energy in the cryptic pocket. The study also identified that the interacting residues are conserved, which is crucial for addressing various virus variants. The findings provide insights into the potential of small molecules as drugs against the spike protein.

Słowa kluczowe:
SARS-CoV-2, Molecular docking, Spike protein, Cryptic pocket, MMPBSA

Streszczenie:
The marine environment is a rich source of microorganisms producing bioactive compounds, like biosurfactant-producing bacteria that exhibit unique characteristics and functionalities. In this study, we examined glycolipid biosurfactants produced by bacteria that live commensally with marine organisms. We isolated a biosurfactant-producing strain identified as Cobetia marina strain F1, which displayed high hemolytic activity (27 mm), oil spreading ability (4 mm), emulsification index (40%), and decreasing surface tension to 31.3 (mN·m−1). Fourier transform infrared (FT-IR) spectroscopy revealed the glycolipid composition of the biosurfactant. Furthermore, elemental analysis utilizing CHNS and energy-dispersive X-ray spectroscopy (EDS) confirmed the biosurfactant contained carbon, hydrogen, nitrogen, sulfur, chlorine, potassium, oxygen, and additional elements. The critical micelle concentration (CMC) of the crude biosurfactant was determined to be 350 mg·L−1, at which concentration, a decrease in surface tension was observed when the biosurfactant was dissolved in distilled water. Given the presence of impurities in the biosurfactant composition, this observed CMC is considered acceptable. Furthermore, the biosurfactant exhibited significant antimicrobial activity against both Gram-positive and Gram-negative bacterial strains, with the largest zone of inhibition (ZOI) of 27 mm against Pseudomonas aeruginosa. This demonstrates the potential of the biosurfactant to serve as an alternative to novel antibiotic agents. The biosurfactant exhibited considerable inhibition of biofilm formation, disruption of preformed biofilms, and reduced enzymatic activity in bacterial cells following treatment. Moreover, the combination of the biosurfactant and F1 bacterial strain enhanced the degradation of crude oil by 86%, indicating its potential application in environmental remediation. These findings highlight the importance of investigating commensal strains capable to produce biosurfactants for applications in hydrocarbon remediation, overcoming antibiotic resistance, and biofilm disruption.

Słowa kluczowe:
sztuczna inteligencja,globalne zagrożenia,interfejs mózg-komputer,potrzeba globalnych regulacji

Słowa kluczowe:
współpraca,mobilność studentów,synergia wyników badań,wspólne dyplomy

Streszczenie:
This study presents a novel, straightforward approach for synthesizing graphitic carbon nitrides (g-C3N4, g-CN) from melamine, requiring merely 30 min of thermal holding at temperatures ranging from 400 to 550 °C in an atmosphere comprising either nitrogen or air. Elemental analysis, X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), diffuse reflectance (UV–Vis DRS), photoluminescence (PL) spectroscopy and scanning electron microscopy (SEM) were employed to assess the quality of the as-prepared powders. Furthermore, theoretical calculations utilizing the Density Functional Theory (DFT) method were conducted to reinforce the experimental findings of the research. A further investigation of the thermal stability of the selected sample was conducted using a unique combination of thermogravimetry–coupled with differential scanning calorimetry, quadrupole mass spectrometry (TG-DSC-MS) and advanced temperature-programmed desorption (TPD) analyzes. The current study focuses on the effect of synthesis conditions (temperature and nitrogen/air environment) on the structure, morphology, and photocatalytic performance of g-C3N4 compounds synthesized using this approach. The g-C3N4-based materials were examined as potential photocatalysts using the acid orange 7 (AO7) photodegradation methodology. To enable comparison of the photodegradation experiments, two separate lamps with wavelengths of 360 nm (UV light) and 420 nm (VIS light) were utilized. The primary objective was to present a novel method for the synthesis of g-C3N4-based materials. This was achieved by demonstrating that organic composites generated at lower temperatures have the best photocatalytic capabilities. Furthermore, the approach to achieving high-quality photocatalysts was shown to be cost-effective, environmentally friendly, and scalable.

Słowa kluczowe:
AgNPs, Fe3O4, bifunctional, SERS, NSAIDS

Streszczenie:
Arm-Z is a concept of a hyper-redundant manipulator based on linearly joined sequence of congruent units. Each unit has only one degree of freedom (1-DOF) - the twist relative to the previous unit.
This paper presents the approach to design of modular robotic manipulator based on computer simulations. The approach is rather standard nowadays, however, it is applied to rather unique robotic system. The
CAD model of the module structure for a manipulator with 6 degrees of freedom and respective Denavit-Hartenberg notation are presented. Simulink - a MATLAB-based graphical programming environment was
used to determine the torques of individual modules. The results of three simulations are presented and discussed. Finally, based on critical observations, the drive and gear for the module of Arm-Z system were selected.

Słowa kluczowe:
Simulation,Robotic arm,Manipulator,Arm-Z,MATLAB Simulink

Streszczenie:
This paper presents the design and construction process of the Arm-Z manipulator, which represents the concept of a hyper-redundant manipulator based on a connected sequence of identical modules. Each
module provides a single degree of freedom (1-DOF), specifically a twist relative to the previous module. The uniformity of the modules gives Arm-Z the potential to be cost-effective and robust. Standardized modules allow for mass production and can be easily replaced in case of failure. This paper discusses each stage of the design process from mechanical perspective, including: module’s geometry, simulation based on Denavit-Hartenberg parameters, and manufacturing process. The section covering work on the electrical system discusses issues such as selection of: motors, power supply, protections, and the network’s topology connecting EPOS controllers.

Słowa kluczowe:
Robotic arm, Manipulator, Hyperredundant, Arm-Z, Extremely Modular System

Streszczenie:
The variability in vestibular schwannoma growth rates greatly complicates clinical treatment. Management options are limited to radiological observation, surgery, radiotherapy and, in specific cases, bevacizumab therapy. As such, there is a pressing requirement for growth restricting drugs for vestibular schwannoma. This study explored potential predictors of vestibular schwannoma growth in depth, highlighting differences between static and growing vestibular schwannoma to identify potential therapeutic targets. High-dimensional imaging was used to characterize the tumour micro-environment of four static and five growing vestibular schwannoma (indicated by volumetric change < 20% or ≥ 20% per year, respectively). Single-cell spatial information and protein expression data from a panel of 35 tumour immune-targeted antibodies identified specific cell populations, their expression profiles and their spatial localization within the tumour micro-environment. Growing vestibular schwannoma contained significantly more proliferative and non-proliferative alternatively activated tumour-associated macrophages per millimetre square compared with static vestibular schwannoma. Furthermore, two additional proliferative cell types were identified in growing and static vestibular schwannoma: transitioning monocytes and programmed cell death ligand 1 (PD-L1+) Schwann cells. In agreement, growing vestibular schwannoma was characterized by a tumour micro-environment composed of immune-enriched, proliferative neighbourhoods, whereas static vestibular schwannoma were composed of tumour-enriched, non-proliferative neighbourhoods. Finally, classically activated macrophages significantly colocalized with alternatively activated macrophages in static vestibular schwannoma, but this sequestration was reduced in growing vestibular schwannoma. This study provides a novel, spatial characterization of the immune landscape in growing vestibular schwannoma, whilst highlighting the need for new therapeutic targets that modulate the tumour immune micro-environment.

Słowa kluczowe:
tumour-associated macrophage, inflammation, tumour micro-environment, vestibular schwannoma, acoustic neuroma

Streszczenie:
We calculated the structural, electronic, and magnetic properties of FeSe within density-functional theory at
the generalized gradient approximation level. First, we studied how the bandwidth of the d-bands at the Fermi
energy is renormalized by adding simple corrections: Hubbard U , Hund’s J, and by introducing long-range
magnetic orders. We found that introducing either a striped or a staggered dimer antiferromagnetic order brings
the bandwidths—which are starkly overestimated at the generalized gradient approximation level—closer to
those experimentally observed. Second, for the ferromagnetic, the striped, checkerboard, and staggered dimer
antiferromagnetic order, we investigate the change in magnetic formation energy with local magnetic moment
of Fe at a pressure up to 6 GPa. The bilinear and biquadratic exchange energies are derived from the Heisenberg
model and noncollinear first-principles calculations, respectively. We found a nontrivial behavior of the spin-
exchange parameters on the magnetization, and we put forward a field-theory model that rationalizes these results
in terms of two-dimensional spin and orbital fluctuations. The character of these fluctuations can be either that
of a standard density wave or a topological vortex. Topological vortices can result in mesoscopic magnetization
structures.

Streszczenie:
This contribution applies the machine learning technique of reinforcement learning for simultaneous damage detection and control of structures. The proposed system consists of two components. The control component is responsible for semi-active mitigation of vibrations. The control law is determined experimentally in a trial-and-error interaction with a simulated environment. The process is data-driven: the control agent iteratively improves its control law based on the observed results of past control actions. The robustness relies on the accuracy of the structural model used for training. The control efficiency can decrease if the physical structure is damaged and diverges from the model, that is, when effective control may be most required. Thus, the second component of the proposed system monitors the structure to detect damages and inform the control component. The approach is tested in a numerical experiment of a shear-building under random seismic-type excitation. A semi-active tuned mass damper (TMD) is used as an actuator, and a classical TMD serves as a reference.

Słowa kluczowe:
semi-active control, structural control, structural monitoring, reinforcement learning, machine learning

Streszczenie:
Classical approaches to attenuation of vibrations usually aim at dissipation or absorption of the vibration energy in especially designed devices mounted to the structure. A less common approach but recognised as very effective is to induce mechanisms of transferring the vibration energy associated with low-frequency modes into higher-order vibration modes, where it is quickly dissipated by material damping (in structural volume). In the present work, a novel semi-active modal control methodology is proposed for precise control of mechanical energy transfer between vibration modes by means of lockable joints. Moreover, this control strategy is well-suited also for energy harvesting purposes. Energy of the currently induced vibration modes can be transferred into a preselected structural vibration mode that is tuned with an energy harvester. The proposed control strategy is verified numerically, whereas its experimental validation is shown in the accompanying article within the present proceedings.

Streszczenie:
In this work an experimental study is presented aiming at demonstration of a controlled modal energy transfer concept in frame structures equipped with semi-active members. The proposed semi-active members – lockable joints – allow for local modification of the frame’s stiffness. The objective of the introduced control approach is to provide mechanical energy transfer between particular eigenmodes. A demonstrator has been fabricated for the purpose of the investigation consisting of a double beam frame structure in a cantilever configuration, which is equipped with the semi-active members. The investigated control algorithm employs two types of input signals: local velocity of the structure and local strain of the frame. As a result, a verification of the system effectiveness has been revealed in a variety of frequency ranges. The excitation bandwidth has been appropriately suited to the particular tested cases. The experimentally obtained results confirmed a possibility of the energy transfers between particular structural eigenmodes.

Słowa kluczowe:
Shape memory alloys, Branched microstructures, Energy minimization, Continuum framework

Słowa kluczowe:
AgriculturalWaste, Animal Origin Fibres, Cement-BasedMaterials, Microstructure, Mechanical Properties

Streszczenie:
Automation in Construction is currently one of the main new directions in Ł-PIAP. Our department is equipped with state-of-the-art devices, such as: an industrial 3D printer with a workspace of 15/5/5 m, capable of printing with concrete or extruded polystyrene and milling; a mobile 3D printer with a workspace of 5/3/3 m with the same capabilities; an industrial KUKA 500 robot with various designated end-effectors; a Wire Arc Additive Manufacturing (WAAM) multi-dimensional device using alloy and steel, etc. Here we present our ongoing projects and prospects that have the potential to revolutionize the construction industry by setting new standards for efficiency, precision and safety.

Streszczenie:
Extremely Modular System (EMS) is a relatively new concept introduced a few years ago. It represents a new approach to the design of engineering structures and architectural objects where assembly of congruent units allows for the creation of free-form shapes. The main difference from the traditional modular systems used in engineering, is the emphasis of the minimal diversity of types of modules, ideally - just one. This is why these system are called "extremely" modular. One of the most natural areas for use of EMSs are deployable structures. This paper presents rigid body folding mechanisms for two selected EMSs: Pipe-Z - a parametric system comprised of one type of module allowing for creation of three-dimensional knots, and Truss-Z - a modular system for creating free-form ramps and ramp networks among any number of terminals.

Słowa kluczowe:
Extremely Modular System, Deployable Structure, Free-form. Pipe-Z, Truss-Z

Streszczenie:
Artificial intelligence (AI) is penetrating higher medical education; however, its adoption remains low. A PRISMA-S search of the Web of Science database from 2020 to 2024, utilizing the search terms “artificial intelligence,” “medicine,” “education,” and “ethics,” reveals this trend. Four key areas of AI application in medical education are examined for their potential benefits: Educational support (such as personalized distance education), radiology (diagnostics), virtual reality (VR) (visualization and simulations), and generative text engines (GenText), such as ChatGPT (from the production of notes to syllabus design). However, significant ethical risks accompany AI adoption, and specific concerns are linked to each of these four areas. While AI is recognized as an important support tool in medical education, its slow integration hampers learning and diminishes student motivation, as evidenced by the challenges in implementing VR. In radiology, data-intensive training is hindered by poor connectivity, particularly affecting learners in developing countries. Ethical risks, such as bias in datasets (whether intentional or unintentional), need to be highlighted within educational programs. Students must be informed of the possible motivation behind the introduction of social and political bias in datasets, as well as the profit motive. Finally, the ethical risks accompanying the use of GenText are discussed, ranging from student reliance on instant text generation for assignments, which can hinder the development of critical thinking skills, to the potential danger of relying on AI-generated learning and treatment plans without sufficient human moderation.

Słowa kluczowe:
Artificial intelligence, Metaverse, Medical education, Education system, Ethics

Streszczenie:
Graph Neural Networks (GNNs) are recognized as potent tools for processing real-world data organized in graph structures. Especially inductive GNNs, which allow for the processing of graph-structured data without relying on predefined graph structures, are becoming increasingly important in a wide range of applications. As such these networks become attractive targets for model-stealing attacks where an adversary seeks to replicate the functionality of the targeted network. Significant efforts have been devoted
to developing model-stealing attacks that extract models trained on images and texts. However, little attention has been given to stealing GNNs trained on graph data. This paper identifies a new method of performing unsupervised model-stealing attacks against inductive GNNs, utilizing graph contrastive learning and spectral graph augmentations to efficiently extract information from the targeted model. The new type of attack is thoroughly evaluated on six datasets and the results show that our approach outperforms the current state-of-the-art by Shen et al. (2021). In particular, our attack surpasses the baseline across all benchmarks, attaining superior fidelity and downstream accuracy of the stolen model while necessitating fewer queries directed toward the target model.

Streszczenie:
The article presents research on finishing treatment applied to components made of Inconel through 3D printing by Laser Powder Bed Fusion method. Vibration-abrasive machining was carried out using a supporting fluid and various shapes of abrasive. The effects of the processing conditions were analysed based on the surface roughness of the samples and mass loss. The obtained collective results were subjected to comparative analysis with the effects of vibratory-abrasive processing without the use of a processing fluid, as presented in the article. The research has shown that using vibration-abrasive processing, it is possible to reduce the height of surface irregularities by more than three times after four hours of treatment. The intensity of processing was the highest in the first hour of the process. The lowest roughness heights Ra = 1.8 μm were obtained using ceramic balls in the presence of a supporting fluid.

Słowa kluczowe:
vibration-abrasive processing, IN939, roughness, additive manufacturing, 3D printing post-processing

Streszczenie:
Symulacje komputerowe odgrywają coraz większą rolę w planowaniu, przygotowaniu oraz interpretacji badań ultradźwiękowych. W artykule opisano podstawowe założenia teoretyczne oraz funkcjonalności programu SymUT rozwijanego w pracowni badań nieniszczących IPPT PAN. W celu ilustracji możliwości programu pokazano proste przykłady jego zastosowania do obliczania rozkładów pola ultradźwiękowego głowic ultradźwiękowych oraz obwiedni echa wad modelowych. Opisano zasady wykorzystania programu do projektowania głowic ultradźwiękowych oraz przygotowania procedur badawczych
Computer simulations are playing an increasingly important role in planning, preparation and interpretation of ultrasonic testing. The article describes the basic theoretical assumptions and functionalities of the SymUT software developed in the non-destructive testing laboratory of IPPT PAN. In order to illustrate its capabilities, simple examples of its use for calculation of the ultrasonic field of ultrasonic probes as well as the echo envelopes from model defects are shown. The principles of using the program for designing of ultrasonic probes and preparing testing procedures are described

Słowa kluczowe:
badania ultradźwiękowe, defektoskopia ultradźwiękowa, wiązka ultradźwiękowa, wady materiałowe, symulacje badań ultradźwiękowych, ultrasonic testing, ultrasonic flaw detection, ultrasonic beam, material defects, ultrasonic testing simulations, radar testing, electromagnetic testing

Streszczenie:
The effect of adjacent threading dislocation at the edge of polar GaN/AlN quantum dot was widely discussed in the literature, see e.g. [1]. Anyway, development of growth techniques for the III-nitrides is moving towards semipolar or even nonpolar orientations, where more efficient radiative recombination is expected due to less significant quantum confinement Stark effect and elimination of spontaneous polarisation. New growth orientations entails entirely new geometry of quantum structures, what calls into question already done analyzes carried out for polar setup. First off all, there are only a few experimental reports showing the real geometry of semipolar and nonpolar quantum dots which differs significantly from well known truncated hexagonal pyramid shape, see e.g. [2]. Secondly, there is no clear information about the geometric relation of the dislocation line and the quantum dot as it was clearly presented in the polar case. However, such relation definitely exists as it is well documented that its dislocation density is much higher compared to crystals grown in the polar regime. Finally, the possible effect of charged dislocation line may additionally alter the optoelectronic properties of the quantum dot [3].

In this work, finite element method is used to determine how the threading dislocation affects semipolar and nonpolar quantum dots and alternates its build-in elastic and electric fields, so in this way modify band-to-band transition energy for the recombining pair of carriers. Threading dislocation, modeled by use of classical continuum dislocation theory via polynomial approximation for distortion field, generates axisymmetric elastic and electric fields. Coupled fields around dislocation line affect neighbouring quantum dot with its build-in fields related to lattice mismatch between GaN dot and AlN matrix and in a limited extent to spontaneous polarisation. Additionally, electric charge localised along the dislocation line is taken into account, and generates extra negative potential field affecting close surroundings of the threading dislocation. Two common types of threading dislocations for III-nitride epitaxial layers are considered: perfect edge- and perfect screw-type dislocation.

It is demonstrated that local elastic and electric fields around threading dislocation together with the presence of an electric charge along dislocation line affect local piezoelectric field build-in the quantum dot, creates geometrical shift of the carrier localization regions, and reduce band-to-band transition energy.

REFERENCES
[1] Rouviere, P.J.L., et al., Appl. Phys. Lett. 75, 1999, 2632.
[2] Dimitrakopulos, G.P., et al., J. Appl. Phys. 108(10), 2010, 104304.
[3] Jurczak, G., Dłużewski, P., Phys. E: Low-Dimens. Syst. Nanostructures, 95, 2018, pp. 11-15.

Słowa kluczowe:
Quantum dot, Threading dislocation, Piezoelectricity, Finite element modeling

Streszczenie:

This study deals with topology optimization of spatial robotic manipulator, the geometry of which was
proposed initially in [1]. The manipulator consists of serially connected modules in a form of a
cylinder cut at a certain angle at its ends. The manipulator constructed in this way allows for relative
rotation of adjacent modules, which gives one degree of freedom per module. The operation of overall
robotic system resembles the elephant trunk manipulator. Previous research involved the possible
kinematic transformations of the manipulator [2], but not its structural optimization [3]. However,
structural design of the involved modules is a challenging task, as the process has to take into account
the current configuration of the module along the manipulator, which results in variable internal force.
It leads to optimization problem under multiple loading conditions with a significantly large number of
loads. This study considers optimal topology of such a modular manipulator structure. Due to the large
variety of possible load conditions, the initial analysis involves a 3D model of the structure with a
continuous set of possible arrangements of individual modules. An additional constraint imposed on
the solution will take into account the symmetry of the optimal topology of a single module, which is
dictated by manufacturing considerations.

Słowa kluczowe:
optimal topology, modular systems, engineering software

Streszczenie:
This presentation considers a semi-active control method aimed at the reduction of structural vibrations in the presence of unknown structural damages. The control algorithm is developed using reinforcement learning [1], a machine learning technique characterized by an iterative trial-and-error interaction of the control agent with the controlled structure. A quasi-optimal control law is derived by observing and learning from the collected interaction experience. By being data-driven, this strategy bypasses the need for an analytical derivation of optimal control, which can be challenging in semi-active and nonlinear control systems [2]. The approach of double Deep Q Learning (DQN) with experience replay is used. It builds upon earlier results [3], but here the aim here is to promote control robustness in the presence of unknown structural damages. The control algorithm is ultimately encoded in the form of a trained artificial neural network with a custom architecture that involves a dedicated damage-identification branch.
The effectiveness of the approach is demonstrated using a numerical model of a structure subjected to a seismic-type random excitation. A semi-active tuned mass damper (TMD) is employed as the actuator, and the control signal affects its viscous damping properties. The reference baseline is provided by the optimally tuned, classical passive TMD.

Słowa kluczowe:
Structural control, Semi-active control, Structural health monitoring (SHM), Reinforcement learning, Machine learning

Streszczenie:
Atomistic models of dislocations in crystalline structures are often obtained by means of elastic-
plastic relaxation of a perfect crystal lattice subjected to external loading. Another method is based
on inserting of single dislocations into the perfect lattice. In this case the analytic formulas for the
glide of a single dislocation in elastic continuum are used. The methods mentioned above do not
give the possibility for emerging atomistic model of an arbitrary chosen network of dislocations. This
problem concerns many sets of dislocations observed by means of high resolution transmission
electron microscopy. In this presentation we introduce a deterministic method for obtaining atomistic
models of dislocations. The method is based on the use of symbolic algebra of elemental lattice
distortion tensor fields. Contrary to the linear strain and rotation measures, the lattice distortion
tensor is the correct measure of finite deformation. Thus, on the basis of distortion field, many
different tensor fields of finite strains and rotations can be determined uniquely. This enables
generation of atomistic models in terms of finite deformation approach [1,2]. The method presented
here links: (i) the analytic formulas for lattice distortions derived from the linear theory of dislocations,
(ii) the finite deformation algebra of distortion fields, and (iii) the atom-by-atom reconstruction of
dislocations including their core structures. This method has been implemented in a visual editor of
dislocations. Configurations of atoms obtained in this way satisfy the stress equilibrium equations in
terms of linear elasticity. On the other hand, the spatial Burgers vectors of dislocations are stretched
and rotated to each other according to the finite deformation theory. The resultant net of atoms can
used as input data to ab-initio and/or molecular dynamics programs to find a low energy configuration
corresponding to a given interatomic potential.

[1] Łażewski J., Jochym P.T., Piekarz P., Sternik M., Parlinski K., Cholewiński J., Dłużewski P.,
Krukowski S., J. Mater. Sci. 54, 10737-10745, 2019.
[2] Cholewiński J., Maździarz M., Jurczak G., Dłużewski P., Int. J. Multiscale Comp. Eng. 9, 411-421,
2014.

Słowa kluczowe:
Ternary transition metal diboride thin films, Mechanical properties, HiPIMS/DC magnetron sputtering, wear resistance and adhesion, DFT Methods

Słowa kluczowe:
Cubic Crystal Structure, Deformable Discrete Element Method, Numerical Modeling, Numerical Homogenization, Elastic Properties

Streszczenie:
The study introduces a methodology that integrates a novel velocity estimation approach with the Particle Filter for accurately estimating the position of an object navigating within a magnetic anomaly field. To accurately determine position in GPS-denied environments, the acceleration measurements obtained from the Inertial Measurement Unit are augmented with magnetic field measurements and a previously designed magnetic anomaly map. Then, Bayesian statistics are employed to fuse information from the Inertial Measurement Unit and magnetometer, enabling accurate estimation of the object's velocity. The estimated velocity serves as input for the propagation model within the Particle Filter, which accurately predicts the object's position. This study showcases the efficacy of Bayesian-based velocity estimation in enhancing the classical Particle Filter approach, resulting in an approximate 40-55% reduction in the mean trajectory error. This refined methodology holds promise for applications across diverse domains, including GPS-independent navigation for vehicles

Streszczenie:
The majority of the current cancer research is based on 2D cell cultures and animal models. These methods have limitations, including different expression of key factors involved in carcinogenesis and metastasis, depending on culture conditions. Addressing these differences is crucial in obtaining physiologically relevant results. Stemness and epithelial-mesenchymal transition (EMT) is linked to the increased invasive potential and metastasis, thus exploring the expression of this markers in a different growth conditions is essential. We report plasticity of expression of selected stem cell and EMT markers in different culture conditions, pointing to the importance of spatial parameters. The most significant difference is the expression of adherent cell junction protein E-cadherin, which changes dramatically between standard 2D culture, floating spheroid culture and matrigel scaffolded culture. As a step towards understanding the reasons causing these discrepancies, we have created a mathematical model of tensions within the 3D bioprinted culture.

Streszczenie:
This paper shows the results of a semi autonomous mobile robot tested in inspection missions during ENRICH 2023 and ELROB 2024. After successful ENRICH 2023 we decided to improve our system by adding LiDAR (Light Detection and Ranging) motion compensation with IMU (Inertial Measurement Unit). Our goal is to provide an affordable robotic solution as open source project available at https://github.com/JanuszBedkowski/msas_enrich_2023. Everything was fine till realistic test during ELROB 2024. Our system works well in 2D scenarios. It is not robust against large slopes. In this paper we show system overview and elaborate its limitations. We demonstrated the use of our open source project https://github.com/MapsHD/HDMapping for 3D map building with the mobile mapping system attached to the robot.

Słowa kluczowe:
mobile robot, semi autonomous, real world task, LiDAR

Streszczenie:
This contribution discusses a semi-active control technique intended for mitigation of structural vibrations. The control law is implemented using the machine learning technique of reinforcement learning, that is in a repeated trial-and-error interaction between the control agent and a simulated environment. Such an approach allows to omit the stage of deriving the optimal control in an analytic way, which is often difficult in nonlinear, semi-actively controlled systems. A specific implementation of the Deep Q Learning (DQN) approach is applied, which promotes control robustness with respect to structural damages. A dedicated network architecture allows the network to be damage-aware, and a specific training procedure involves not only the observations, control actions, and rewards, but also the current health status of the structure.

A numerical example is provided involving a shear-type building model subjected to a seismic excitation. The actuator takes the form of a tuned mass damper (TMD), which is semi-actively controlled by changing the level of viscous damping. The optimally tuned classical passive TMD is used as the baseline reference damping system.

Streszczenie:
Additive manufacturing (AM) is revolutionizing production with its ability to rapidly create complex designs while minimizing material waste. The influence of the SLM parameters on mechanical properties of two sets of open cell lattices (Set A and Set B) made of IN718 was investigated. The purpose of using the modified parameters was to reduce the cost/time of manufacturing as well as to reduce microporosity in ligaments by increased exposure time (reduced laser scanning speed) or higher energy density based on increased exposure time. The researchers investigate ligament deformation and collapse in porous lattices, its impact on overall behavior, and how microstructure influences hardening under varying strain rates.

Słowa kluczowe:
highly porous random open-cell lattice, additive manufacturing, direct impact Hopkinson pressure bar technique, Inconel 718

Streszczenie:
The analysis of nanostructures at the atomic level requires knowledge of interatomic interactions. There is a lot of data available in the literature for potentials, but it is often necessary to adjust the parameters of interatomic interactions for unusual structures, e.g. two dimensional materials. The aim of this work is to present a method for the optimal selection of interatomic parameters using machine learning techniques. Reinforced learning is one of the groups of methods that allow the use of artificial intelligence in the selection of parameters or models of real systems. The article uses the Monte Carlo Tree Search method [1,2] combined with local and global optimization algorithms for the optimal selection of silicon potential parameters for two dimensional structures.
The research used Molecular Dynamics (MD) to simulate nanostructures, and based on the results, nanostructure parameters were determined and compared with standard data from the literature. The aim of the optimization was to ensure the greatest possible compliance of the nanostructure parameters with the reference data. MD analyses were performed using the LAMMPS package [3].
The full article presents a description of the method as well as numerical examples for the two dimensional structure of silicon – silicene.

Słowa kluczowe:
Reinforced Learning, Optimization, Interatomic potential, Nanostructure

Streszczenie:
The aim of this work is to present a method for optimizing the mechanical properties of a nanostructure based on Silicene. Optimization is carried out using a parallel evolutionary algorithm and parallel Molecular Dynamics analyses used to determine material properties. Due to high computational costs, optimization was carried out using one of the fastest supercomputers in the world – LUMI installed in CSC in Kajaani, Finland.

Słowa kluczowe:
Methods of computational intelligence, 2D nanostructures, Molecular dynamics

Streszczenie:
Additive manufacturing, widely called 3d printing, allows to create new quality of metal products. A microstructure of 3d printed AlSi10Mg alloy can be described as an eutectic area surrounded by Si-network. Eutectic, fine-grain microstructure improves durability of material in comparison to cast, dendritic aluminium alloys. The presence of Si particles is challenging for electrochemical surface treatments, for instance to anodizing. In this study, Plasma Electrolytic Oxidation (PEO) – the most environmentally-friendly kind of anodizing – was performed on the cast AlSi10Mg and on the 3d printed AlSi10Mg specimens.

Słowa kluczowe:
3d printing, Laser Powder Bed Fusion Process,Plasma Electrolytic Oxidation, aluminium

Streszczenie:
The work presents a comprehensive approach to the design and modelling of acoustic materials based on labyrinth structures filled with fibres. It has recently been shown that exceptionally favourable acoustic properties can be obtained in labyrinthine materials due to their extreme tortuosity. Such materials, typically produced by methods such as 3D printing, exhibit high sound absorption values at lower frequencies. The next step in the development of this type of acoustic treatment (explored here) involves introducing fibres into labyrinthine channels. Such acoustic composite designs can have a beneficial effect of shifting the absorption peak to even lower frequencies and also widening its efficiency range. Two samples of slotted labyrinth materials, designed using analytical acoustic modelling, were 3D printed, and their slits were filled with selected fibrous materials, such as biofibres, cotton wool, acrylic yarn, etc. They were tested in an impedance tube to confirm the predicted improvement, but also to show a dramatic change in sound absorption.

Streszczenie:
Selective laser sintering and binder jetting are two additive manufacturing technologies that use loose powder as a feedstock. In the case of binder jetting, the printout walls are essentially permeable and need to be additionally impregnated to be fully air-tight. The permeability of sintered objects, on the other hand, can be controlled to some extent by the amount of laser energy, among other things, provided to the exposed layer. Exploring these two technologies, several single- and double-porosity samples were additively manufactured, examined and acoustically measured in an impedance tube. Moreover, the normal incidence sound absorption spectra resulting from these structures were predicted employing multi-scale methods. The values of porosity and permeability of permeable printed materials were determined and utilised in the applied modelling. It is observed that making the skeleton microporous and permeable enables effective sound absorption even in primitive 3D printed acoustic treatments.

Streszczenie:
In this work, slotted acoustic materials based on a space filling curve called the Peano-Gosper curve are proposed and investigated. The slits in such materials form a complex pattern because they are divided by walls built along lines generated by the Gosper curve algorithm. The pattern can be twisted around an axis normal to its surface to increase the tortuosity inside the material, and therefore, modify its acoustic properties, which can be controlled by the turning angle or pitch of the twist. A highly efficient semi-analytical model has been developed to accurately predict the acoustic properties, in particular the sound absorption of such materials. It only requires a representative part of the pattern, or better, scanning the surface of the fabricated material so that the actual geometry and dimensions (in particular slit widths) are well reproduced in a two-dimensional finite element mesh generated on a representative fluid domain. The mesh is used to solve a dedicated Poisson problem and determine a few key parameters, and the rest of the modelling is based on analytical formulas. Material samples with straight and twisted slit patterns were 3D printed and then measured in an impedance tube to confirm semi-analytical sound absorption predictions.

Słowa kluczowe:
Air-drop Capsule, Impact Mitigation, Adaptable Airbag, Discharge Valve

Streszczenie:
The contribution presents a numerical and experimental investigation of a novel control method developed
to adaptively mitigate impact loading of unknown characteristics. The adaptivity of the method relies on on-
line tracking of system kinematics and application of kinematic optimality condition utilizing actual values of
system displacements and accelerations. The original kinematics-based approach enables the determination
of the optimal force vs time dependency, optimizing system response under dynamic loading. The control
process is executed using piezoelectric valve with embedded strain gauge, which allows for proportional
control of the actual gas flow rate between two chambers of the damper. The conducted investigation proves
that integrating the kinematics-based control with a proportional piezoelectric valve results in a novel self-
adaptive system capable to adjust to unknown dynamic loads of unpredictable characteristics.

Streszczenie:
Mixture of Experts (MoE) models have emerged as a primary solution for reducing the computational cost of Large Language Models. In this work, we analyze their scaling properties, highlighting certain arbitrary assumptions present in the existing literature. In particular, we introduce a new hyperparameter, granularity, the modification of which allows for the optimal adjustment of the size of experts. Subsequently, we present scaling laws for fine-grained MoE, taking into account the number of training tokens, model size, and granularity. Using these scaling laws, we derive the optimal training configuration for a given computational budget. Furthermore, in contrast with previous works, we demonstrate that the gap in efficiency between dense and MoE models grows as we scale up the model size and training budget.

Streszczenie:
State Space Models (SSMs) have become serious contenders in the field of sequential modeling, challenging the dominance of Transformers. At the same time, Mixture of Experts (MoE) has significantly improved Transformer-based Large Language Models, including recent state-of-the-art open models. We propose that to unlock the potential of SSMs for scaling, they should be combined with MoE. We showcase this on Mamba, a recent SSM-based model that achieves remarkable performance. Our model, MoE-Mamba, outperforms Mamba and matches the performance of Transformer-MoE. In particular, MoE-Mamba reaches the same performance as Mamba in 2.35x fewer training steps while preserving the inference performance gains of Mamba against Transformer.

Streszczenie:
A new breed of gated-linear recurrent neural networks has reached state-of-the-art performance on a range of sequence modeling problems. Such models naturally handle long sequences efficiently, as the cost of processing a new input is independent of sequence length. Here, we explore another advantage of these stateful sequence models, inspired by the success of model merging through parameter interpolation. Building on parallels between fine-tuning and in-context learning, we investigate whether we can treat internal states as task vectors that can be stored, retrieved, and then linearly combined, exploiting the linearity of recurrence. We study this form of fast model merging on Mamba-2.8b, a pretrained recurrent model, and present preliminary evidence that simple linear state interpolation methods suffice to improve next-token perplexity as well as downstream in-context learning task performance.

Streszczenie:
Mixture of Experts (MoE) models based on Transformer architecture are pushing the boundaries of language and vision tasks. The allure of these models lies in their ability to substantially increase the parameter count without a corresponding increase in FLOPs. Most widely adopted MoE models are discontinuous with respect to their parameters - often referred to as sparse. At the same time, existing continuous MoE designs either lag behind their sparse counterparts or are incompatible with autoregressive decoding. Motivated by the observation that the adaptation of fully continuous methods has been an overarching trend in Deep Learning, we develop Mixture of Tokens (MoT), a simple, continuous architecture that is capable of scaling the number of parameters similarly to sparse MoE models. Unlike conventional methods, MoT assigns mixtures of tokens from different examples to each expert. This architecture is fully compatible with autoregressive training and generation. Our best models not only achieve a 3× increase in training speed over dense Transformer models in language pretraining but also match the performance of state-of-the-art MoE architectures. Additionally, a close connection between MoT and MoE is demonstrated through a novel technique we call transition tuning.

Streszczenie:
Background, Motivation and Objective
Flexible ultrasound (US) arrays are a promising technology that may further democratize US technology — e.g. in wearable US. Flexible transducers also pose challenges in image reconstruction, as they require adaptable beamforming delays due to a changing geometry of the probe. Various approaches have been proposed for flexible array shape estimation and beamforming, e.g. external sensors, deep learning and optimization. In this work, we propose a deep reinforcement learning (DRL) approach, where a software agent is responsible for tracking the array shape to properly reconstruct US B-mode image.

Statement of Contribution/Methods
Here we considered a reinforcement learning environment as a setup consisting of a US system with the flexible array and point targets phantom. The environment was simulated using j-Wave software. The environment’s state consisted of the current shape of the array, modeled as a sinusoid s = a sin(bx + c), and the current model of the array assumed by the beamformer: s’ = a’ sin(b’x + c’) (single-element STA scheme). A single episode consisted of
7 steps; the parameters a, b, c could vary from step to step (within bounds of physical constraints). The agent observed the current B-mode, could modify the current values of a’, b’ and c’ (action) and received a reward equal to the linear combination of the coherence factor and structural similarity index measure (SSIM) between the current and reference image. We trained our agent using TD3 approach and tested it for various settings of a, b and c.

Results/Discussion
Our agent achieved an average SSIM of 0.73 per episode step. Figure 1 shows the sequence of states and images within an example episode; the agent was able to correctly react to the change of the array shape. The DRL approach has the following advantages compared to other methods: the agent can be trained to operate in an environment with a changing state; and the agent can be trained to maximize expected return (dependent on beamforming quality metric), which does not have to be differentiable.

Fig. 1. (Top) B-mode images, estimated array shape (red) and actual shape (black) within an example episode. (Bottom) Coherence factor and SSIM achieved by the agent during the episode

Słowa kluczowe:
Vibration Damping, Particle Impact Damper, Adaptive Pneumatic Damper

Streszczenie:
Kompozytowe podwozie samolotu Skyleader GP ONE poddane zostało obciążeniom symulującym warunki przyziemienia podczas lądowania samolotu, a także próbie niszczącej. Zweryfikowano możliwość wskazania lokalizacji obszarów maksymalnej koncentracji naprężeń zredukowanych przy zastosowaniu uproszczonego modelowania, wykonanego przy założeniu izotropowości materiału podwozia. Do przeprowadzenia testów laboratoryjnych posłużyło unikalne stanowisko z wieżą zrzutową, posiadające pionowy i poziomy układ łożysk liniowych.

Słowa kluczowe:
zrzutownik, podwozie samolotu ultralekkiego, model izotropowy

Streszczenie:
Breast cancer is the most common cancer in women, and ultrasound
(US) imaging is important for breast mass assessment. Accurate automatic
breast mass segmentation facilitates mass characterization. Traditional deep
learning methods, such as convolutional networks and transformers, have
achieved high performance in breast mass segmentation. Recently, implicit
neural representations, which use continuous, nonlinear, coordinate-based
approximations through multi-layer perceptrons, have shown promise
in various fields, including medical image segmentation. In this work, we
present an implicit network for breast mass segmentation in US. We train a
coordinate-based implicit network to jointly output the US image pixel values
and the segmentation pixel scores. The network is conditioned using latent
codes, effectively associating the regression and segmentation tasks with the
mass type (benign/malignant) and BI-RADS category. Additionally, a trainable
image-specific code is used. During inference, given a US image, we fix the
weights of the network and use the backpropagation algorithm to determine
the latent codes, facilitating the image regression task. This process, due to the learned associations, also provides the segmentation mask. Our results
confirm the feasibility of using implicit networks for breast mass segmentation
and other tasks leveraging learned associations between latent codes and
image/mask appearances.

Słowa kluczowe:
leśnictwo, sztuczna inteligencja, uczenie maszynowe

Streszczenie:
Segmentation of biomedical images is often ambiguous and complicated by noise, varying
contrasts, and imaging artifacts. We address the challenge of segmenting images of brain
tissue in which gene expression has been localized using in situ hybridization. Since gene
expression patterns differ widely between genes, it can be difficult to correctly discriminate
pixels positive for gene expression. In testing different segmentation networks, we observed
that each network had its own trade-offs between sensitivity and precision. To exploit
the benefits of all trained networks, we developed a meta-network that learns to combine
multiple segmentation maps from diverse segmentation architectures to generate a final
segmentation that best matches the ground-truth label. In our experiments, the meta-
network outperforms ensembles that simply average segmentation maps.

Słowa kluczowe:
meta-learning, segmentation, gene expression

Streszczenie:
Accurate estimation of the speed-of-sound (SoS) is important for ultrasound (US) image reconstruction techniques and tissue characterization. Various approaches have been proposed to calculate SoS, ranging from tomography-inspired algorithms like CUTE to convolutional networks, and more recently, physics-informed optimization frameworks based on differentiable beamforming. In this work, we utilize implicit neural representations (INRs) for SoS estimation in US. INRs are a type of neural network architecture that encodes continuous functions, such as images or physical quantities, through the weights of a network. Implicit networks may overcome the current limitations of SoS estimation techniques, which mainly arise from the use of non-adaptable and oversimplified physical models of tissue. Moreover, convolutional networks for SoS estimation, usually trained using simulated data, often fail when applied to real tissues due to out-of-distribution and data-shift issues. In contrast, implicit networks do not require extensive training datasets since each implicit network is optimized for an individual data case. This adaptability makes them suitable for processing US data collected from varied tissues and across different imaging protocols. We evaluated the proposed SoS estimation method based on INRs using data collected from a tissue-mimicking phantom containing four cylindrical inclusions, with SoS values ranging from 1480 m/s to 1600 m/s. The inclusions were immersed in a material with an SoS value of 1540 m/s. In experiments, the proposed method achieved strong performance, clearly demonstrating the usefulness of implicit networks for quantitative US applications.

Słowa kluczowe:
beamforming, deep learning, implicit neural representations, speed-of-sound, quantitative ultrasound

Słowa kluczowe:
Ni-free shape memory alloys, interstitials atoms, stress-induced phase transformation, acoustic emission

Słowa kluczowe:
High entropy alloys, high entropy nitrides, nitriding, nanoindentation, ion implantation

Słowa kluczowe:
composite, coating, metal matrix, wear, interfacial strength

Słowa kluczowe:
nanoindentation, micropillars compression, high entropy alloys, nitriding, ion implantation

Słowa kluczowe:
Detonation, Detonation damping, Flow control

Słowa kluczowe:
Deformation-induced martensitic transformation, Austenitic Stainless Steel, Additive Manufacturing, DIC, Cryogenic temperatures

Słowa kluczowe:
Phase transformation, Deformation-induced martensitic transformation, 316L, Fused Deposition Modelling

Streszczenie:
he Institute of Fundamental Technological Research's Microfluidic Laboratory
is focused on enhancing the accuracy and practical use of microfluidic methods for chemical
and biological studies, as well as creating tailored microfluidic instruments to address
specific biological research needs. In this document, we present a few of our latest projects.

Słowa kluczowe:
Micro-, Nano- and Bio-flows, Multi-phase Flows, Droplets

Streszczenie:
Ceramic materials are commonly used in plungers due to high resistance to wear, abrasion, and low coefficient of thermal expansion. Also, they are commonly used in dry conditions without permanent damage, ceasing of pump head and better corrosion resistance than metals due to their inert characteristics. Zirconia (ZrO2) ceramic is used due to its high strength whereas, alumina (Al2O3) is commonly used in industries for high pressure pumps. The toughness of zirconia ceramics is higher than alumina ceramics as it overcomes the inherent brittleness of ceramic materials. It also has higher wear resistance and extends the life of the product. Whereas alumina has better mechanical characteristics such as hardness compared to Zirconia. In this research work tribological behavior of Alumina and Zirconia ceramics used in high pressure pumps have been studied. The wear test using end face wear testing apparatus has been conducted under flat contact for both alumina and ceramic material considering a mean contact pressure of 10 N, 20 N, 30 N and 40 N and sliding velocity of 40 mm/s. The wear test was conducted for 30 min considering a total sliding distance of 1500 m and 3000 m. The wear test results indicate that both alumina and ceramic exhibit lower wear factors and superior mechanical properties. The findings also reveal that the wear rates of Al2O3 and ZrO2 are influenced by friction forces, subsequently impacting the overall wear rate. Also, as the load increases the surface contact area also increases which in turn increases the wear rate. However, zirconia could be a potential substitute for alumina due to its high strength and fracture toughness.

Słowa kluczowe:
Ceramics, Composites, Alumina, Zirconia, Wear rate, Toughness

Słowa kluczowe:
anning electron microscopy, in-situ mechanical tests, hot-pressing

Streszczenie:
The problem of safe, impact loads absorption is present in a wide class of applications, and particularly where direction of the object's movement is well-defined, for example: precise docking systems, rail car buffers or landing gear shock absorbers. In those applications the objective is to absorb gradually impact energy, minimizing the deceleration peak. For safety reasons, the class of drop-caps (eg. in delivery business) or bigger airdrops from airplanes or from stratospheric airships (space debris) becomes a challenge for next decades. However, knowing the dropping mass and estimating the touchdown velocity, our SAI shock-absorbers (cf. [1]) made of multi-layered, "delaminable" panels, can be adapted to the expected impact. Therefore, let us concentrate on the SAI concept based on the following steps: -- design a multi-layer structure capable of semi-active "delamination" control along the contact infrastructure (slipping lines). -- apply an actuator realizing the on/off type of semi-active control for slipping lines' activation, playing the role of structural clutch (cf. the actuator in the so-called PAR vibration suppression technique, [2-3]), -- apply various characteristics for the contact interfaces (friction coefficient), -- apply various control strategies for the slipping lines activation (and releasing of the pre-stress effect), depend on the case study and identified on-line impact parameters. The effectiveness of the proposed, adaptive approach to impact absorption (so-called Depress Dampers) will be compared versus traditional shock-absorbers, based on passive honeycomb panels (cf. also adaptive pneumatic shock-absorber concept).

Streszczenie:
In breast cancer diagnosis, early detection of tumors and accurate differentiation of malignant and benign breast lesions are key demands. Tumor size, as a measure of tumor progression, is related to recurrence rate and patient survival. This study aims to determine which sonographic features al- low the differentiation of small breast lesions into benign and malignant. Inclusion criteria for the analysis were tumors with the longest diameter of less than or equal to 10 mm and tumors with confirmed classification by follow-up care or core needle biopsy result. Following the criteria, 1515 cases were analyzed, including 365 carcinomas and 1150 benign lesions. To quantitatively evaluate the images, 383 ultrasound parameters
(BI-RADS features, morphological features, fractal features, his- togram features, and texture parameters) were used. Univariate and multiple logistic regression analyses were used to assess the significance of various diagnostic features and their combinations. The combined classifier (based on 19 quantitative features) yields an area under the ROC curve of 0.91.

Słowa kluczowe:
Ultrasound imaging, Breast cancer, Small lesion, Feature extraction

Streszczenie:
This paper presents a novel low cost 3D mapping system designed for fulfilling the gap between existing solutions and constantly growing end-users’ expectations. Firstly, the cost was reduced to minimum by providing an open-source, open-hardware projects. Secondly, the ergonomic, light weight, reconfigurable approach enables a wearable approach to maximize the mobility of the end user. It allows among other things the freedom to walk, crawl and climb. Those are necessities in extreme mobile mapping applications such as cave mapping, construction site survey, search and rescue missions and other unexplored yet applications such as mobile mapping with K9s (trained dogs equipped with 3D mobile mapping systems). The significance of this research is to provide cost effective mobile mapping solution for as large audience as it is possible. Thus, our software is constantly improved for covering more applications e.g. air + ground + underground mapping.

Słowa kluczowe:
Mobile mapping system, SLAM, LiDAR odometry, Normal Distributions Transforms, Gaussians

Streszczenie:
The topic of smart civil infrastructure has attracted significant attention. An important component of such structural systems is the network of sensors used to monitor the structure and deliver information about its current health status. The task of optimal sensor placement is not trivial due to the discrete, combinatorial nature of the problem. The brute force search is unfeasible for large structures, which calls for approximate and heuristic approaches. This problem has been investigated for several decades, beginning probably with the landmark 1978 paper of Shah [1]. A recent review can be found in [2].

The criteria typically used for assessing candidate placements are based either on Kammer’s Effective Independence (EFI) and the Fisher Information Matrix (FIM) [3], and quantify the amount of information provided by sensors, or on covariance matrices obtained within the Kalman filtering procedure used to quantify the uncertainty of the unknown response of interest being estimated [4]. However ingenious, most of the proposed procedures are computationally costly in large-scale problems.

This talk will discuss two optimal placement methods that have been recently developed with the objective of computational efficiency [5, 6]. One of them is based on Kalman filter covariance matrices and has—instead of typically quadratic—a linear complexity in the number of potential sensor locations. The other method uses the technique of convex relaxation to represent the problem in a computationally tractable continuous form and speed up the solution procedure even further. The presented application examples will use models of bridge structures.

[1] P.C. Shah, F.E. Udwadia, A methodology for optimal sensor locations for identification of dynamic systems, J. Appl. Mech. 45(1), 188–196 (1978)
[2] Y. Tan, L. Zhang, Computational methodologies for optimal sensor placement in structural health monitoring: A review, Struct. Health Monit. 19(4), 1287–1308 (2020)
[3] D.C. Kammer, Sensor placement for on-orbit modal identification and correlation of large space structures, J. Guid. Control Dyn. 14(2), 251–259 (1991)
[4] C. Zhang, Y.-L. Xu, Optimal multi-type sensor placement for response and excitation reconstruction, J. Sound Vib. 360, 112–128 (2016)
[5] B. Błachowski, A. Świercz A., M. Ostrowski, P. Tauzowski, P. Olaszek, L. Jankowski, Convex relaxation for efficient sensor layout optimization in large-scale structures subjected to moving loads, Comput.-Aided Civ. Inf. 35(10), 1085–1100 (2020)
[6] B. Błachowski, A. Świercz, P. Olaszek, Ł. Jankowski, Implementation of multi-type sensor placement strategy for large-scale engineering structures, 10th ECCOMAS Thematic Conference on Smart Structures and Materials (SMART 2023), July 3–5, 2023, Patras, Greece, pp. 498–506 (2023)

Słowa kluczowe:
eight-node (hexahedron) solid-shell elements, standard or partial Hu-Washizu functionals, reduced representations of assumed stress/strain, EAS for the thickness strain, skew coordinates