Institute of Fundamental Technological Research

Barros G., Sapucaia V., Hartmann P., Pereira A., Rojek J., Thoeni K., A novel BEM-DEM coupling in the time domain for simulating dynamic problems in continuous and discontinuous media, COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING, ISSN: 0045-7825, DOI: 10.1016/j.cma.2023.116040, Vol.410, pp.1-25, 2023

Abstract:
This work presents a novel scheme to couple the Boundary Element Method (BEM) and the Discrete Element Method (DEM) in the time domain. The DEM captures discontinuous material behaviour, such as fractured and granular media. However, applying the method to real-life applications embedded into infinite domains is challenging. The authors propose a solution to this challenge by coupling the DEM with the BEM. The capability of the BEM to model infinite domains accurately and efficiently, without the need for numerical artifices, makes it the perfect complement to the DEM. This study proposes a direct monolithic interface-based coupling method that resolves any incompatibilities between the two methods in two dimensions. The benchmark results show that the proposed methodology consistently produces results that align with analytical solutions. The final example in the paper showcases the full potential of this innovative methodology, where the DEM models a fracturing process, and the BEM evaluates its far-field effect.

Keywords:
Discrete Element Method (DEM), Boundary Element Method (BEM), Discontinuous materials, Wave propagation, Infinite domain, Monolithic coupling

Barros G., Pereira A., Rojek J., Carter J., Thoeni K., Efficient multi-scale staggered coupling of discrete and boundary element methods for dynamic problems, COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING, ISSN: 0045-7825, DOI: 10.1016/j.cma.2023.116227, Vol.415, pp.1-28, 2023

Abstract:
This paper presents a novel and highly efficient approach for coupling the Discrete Element Method (DEM) and the Boundary Element Method (BEM) for time-domain simulations of dynamic problems, utilising multi-scale staggered time integration. While the DEM captures phenomena with discontinuous behaviours, such as fracturing and granular flow, the BEM excels in accurately modelling seismic wave propagation in infinite domains. By separately solving the governing equations of the DEM and BEM at different time instants, the proposed scheme considerably enhances computational efficiency compared to conventional monolithic coupling schemes. The incorporation of non-conforming interfaces enables larger time steps in the BEM, thereby reducing computational costs and memory usage. Moreover, an innovative coupling of DEM rotations with the BEM displacement field is introduced, leading to more accurate and realistic modelling of complex dynamics. Numerical experiments are conducted to demonstrate the superior accuracy and efficiency of the proposed method, establishing its potential for modelling a wide range of dynamic problems.

Keywords:
BEM-DEM coupling,Multi-scale time integration,Rotational degrees of freedom,Seismic wave propagation,Infinite domain

Chmielewski M., Zybała R., Strojny-Nędza A., Piątkowska A., Dobrowolski A.P., Jagiełło J., Diduszko R., Bazarnik P., Nosewicz S., Microstructural Evolution of Ni-SiC Composites Manufactured by Spark Plasma Sintering, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-023-06999-w, Vol.-, No.-, pp.---, 2023

Abstract:
The presented paper concerns the technological aspects of the interface evolution in the nickel-silicon carbide composite during the sintering process. The goal of our investigation was to analyse the material changes occurring due to the violent reaction between nickel and silicon carbide at elevated temperatures. The nickel matrix composite with 20 vol pct SiC particles as the reinforcing phase was fabricated by the spark plasma sintering technique. The sintering tests were conducted with variable process conditions (temperature, time, and pressure). It was revealed that the strong interaction between the individual components and the scale of the observed changes depends on the sintering parameters. To identify the microstructural evolution, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy were used. The silicon carbide decomposition process progresses with the extension of the sintering time. As the final product of the observed reaction, new phases from the Ni-Si system and free carbon were detected. The step-by-step materials evolution allowed us to reveal the course of the reaction and the creation of the new structure, especially in the reaction zone. The detailed analysis of the SiC decomposition and formation of new components was the main achievement of the presented paper.

Munawar A., Sadeeda ., Asif V., Jafri A., Nisar F., Wegener M., Su J., Kargl F., Effect of Undercooling on the Microstructure and Mechanical Properties of Hyper-eutectic Ni–Sn Alloy, METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ISSN: 1073-5623, DOI: 10.1007/s11661-023-07172-z, pp.1-9, 2023

Abstract:
In this study, container-less solidification of hyper-eutectic Ni–Sn alloy has been performed by using the electromagnetic levitation technique. The effect of undercooling on the formed microstructure and on the mechanical properties have been investigated. Growth velocities were determined by high-speed video-imaging of the solidification process. A step change in the growth velocities that are increasing with increasing undercooling is observed. This aligns with an observed first change in the microstructure between low and intermediate undercoolings. At the lower undercoolings, a pro-eutectic Ni3Sn phase along with lamellar eutectic structure in the inter-dendritic region is found. At intermediate undercooling of 100–150 K, a divorced eutectic microstructure is observed whereas at undercoolings above 165 K α-Ni precipitates are observed within β-Ni3Sn dendrites. Microhardness testing revealed higher strength for the lamellar phase as compared to the non-lamellar phase. Nano-indentation has been performed to determine the hardness and strength of individual phases in the microstructure.

Tahani M., Postek E.W., Sadowski T., Diffusion and Interdiffusion Study at Al- and O-Terminated Al2O3/AlSi12 Interface Using Molecular Dynamics Simulations, Materials, ISSN: 1996-1944, DOI: 10.3390/ma16124324, Vol.16, No.12, pp.4324-1-11, 2023

Abstract:
The equivalent characteristics of the materials’ interfaces are known to impact the overall mechanical properties of ceramic–metal composites significantly. One technological method that has been suggested is raising the temperature of the liquid metal to improve the weak wettability of ceramic particles with liquid metals. Therefore, as the first step, it is necessary to produce the diffusion zone at the interface by heating the system and maintaining it at a preset temperature to develop the cohesive zone model of the interface using mode I and mode II fracture tests. This study uses the molecular dynamics method to study the interdiffusion at the interface of α-Al2O3/AlSi12. The hexagonal crystal structure of aluminum oxide with the Al- and O-terminated interfaces with AlSi12 are considered. A single diffusion couple is used for each system to determine the average main and cross ternary interdiffusion coefficients. In addition, the effect of temperature and the termination type on the interdiffusion coefficients is examined. The results demonstrate that the thickness of the interdiffusion zone is proportional to the annealing temperature and time, and Al- and O-terminated interfaces exhibit similar interdiffusion properties

Keywords:
self-diffusion , interdiffusion, diffusion coefficient, Al2O3/AlSi12 interface, molecular dynamics

Pokorska I., Poński M., Kubissa W., Libura T., Brodecki A., Kowalewski Z.L., Computational Fracture Evolution Analysis of Steel-Fiber-Reinforced Concrete Using Concrete Continuous Damage and Fiber Progressive Models, Materials, ISSN: 1996-1944, DOI: 10.3390/ma16165635, Vol.16, No.5635, pp.1-20, 2023

Abstract:
The process of concrete cracking is a common problem because the first micro-cracks due to the loss of moisture may appear even before the concrete is loaded. The application of fracture mechanics allows for a better understanding of this problem. Steel-fiber-reinforced concrete (SFRC) samples with a notch were subjected to a three-point bending test, and the results for crack energy were used to analyze the concrete’s material properties. In this paper, an experimental and numerical analysis of SFRC with rapid changes in the force (F) crack mouth opening displacement (CMOD) curve (F-CMOD) is presented. In order to obtain the relevant F-CMOD diagrams, three-point bending tests were carried out with non-standard samples with a thickness equal to one-third of the width of standard samples. For analysis purposes, crimped steel fibers were adopted. A probabilistic analysis of the most important parameters describing the material in question, such as peak strength, post-cracking strength, crack mouth opening displacement (CMOD), fracture energy, and the post-cracking deformation modulus, was conducted. The tests and the analysis of their results show that the quasi-static numerical method can be applied to obtain suitable results. However, significant dynamic effects during experiments that influence the F-CMOD curves are hard to reflect well in numerical calculations.

Keywords:
concrete, finite element method (FEM) simulations, steel-fiber-reinforced concrete (SFRC), crack mouth opening displacement (CMOD), steel fibers

Hartmann P., Thoeni K., Rojek J., A generalised multi-scale Peridynamics–DEM framework and its application to rigid–soft particle mixtures, COMPUTATIONAL MECHANICS, ISSN: 0178-7675, DOI: 10.1007/s00466-022-02227-1, Vol.71, pp.107-126, 2023

Abstract:
The discrete element method (DEM) is the most dominant method for the numerical prediction of dynamic behaviour at grain or particle scale. Nevertheless, due to its discontinuous nature, the DEM is inherently unable to describe microscopic features of individual bodies which can be considered as continuous bodies. To incorporate microscopic features, efficient numerical coupling of the DEM with a continuous method is generally necessary. Thus, a generalised multi-scale PD–DEM framework is developed in this work. In the developed framework, meshfree discretised Peridynamics (PD) is used to describe intra-particle forces within bodies to capture microscopic features. The inter-particle forces of rigid bodies are defined by the DEM whereas a hybrid approach is applied at the PD–DEM interface. In addition, a staggered multi-scale time integration scheme is formulated to allow for an efficient numerical treatment of both methods. Validation examples are presented and the applicability of the developed framework to capture the characteristics mixtures with rigid and deformable bodies is shown.

Keywords:
Peridynamics (PD),Discrete element method (DEM),Contact coupling,Multi-scale modelling,Deformable particles

Wiśniewski K., Turska E., Reduced representations of assumed fields for Hu–Washizu solid-shell element, COMPUTATIONAL MECHANICS, ISSN: 0178-7675, DOI: 10.1007/s00466-023-02275-1, Vol.71, pp.957-990, 2023

Abstract:
Mixed eight-node (hexahedron) solid-shell elements based on the standard or partial version of the three-field Hu–Washizu (HW) functionals are developed for Green strain. Three reduced representations of the assumed stress/strain fields are selected. They improve effectiveness, yet retaining good accuracy and convergence properties. At the outset, the standard HW functional and the assumed stress/strain representations of the 3D solid element B8-15P (Weissman in Int J Numer Methods Eng 39:2337–2361, 1996) are used to derive a solid-shell element with 51 parameters. To eliminate locking, the ANS method is applied to the thickness strain (Betsch and Stein in Commun Numer Methods Eng 11:899–909, 1995) and to the transverse shear strain (Dvorkin and Bathe in Eng Comput 1:77–88, 1984). It is a correct element which, however, yields too large displacements for coarse meshes and trapezoidal through-thickness shapes. To improve the above formulation, the ζ-independent reduced representations of the assumed stress/ strain fields are selected and the transformations to Cartesian components are modified. The thickness strain is enhanced by the EAS method. The element with 35 parameters is derived from the standard/enhanced HW functional, but, to further reduce the assumed fields, partial/enhanced HW functionals are constructed from the 3D potential energy by applying the Lagrange multiplier method only to selected strain components. In the element with 27 parameters, this is applied to the constant in-plane strain and to the transverse shear strain while in the element with 19 parameters, to the constant in-plane strain only.Two other modifications are implemented to enhance the behavior of these elements: (A) the skew coordinates are used in the reduced representations of the in-plane stress/strain (Wisniewski and Turska in Int J Numer Methods Eng 90:506–536, 2012), and (B) the Residual Bending Flexibility correction of the transverse shear stiffness (MacNeal in Comput Struct 8(2):175–183, 1978) is adapted. Finally, the performance of the proposed solid-shell HW elements is demonstrated on several linear and non-linear examples for the linear elastic material and the hyper-elastic material. The proposed elements are compared to each other and to the best existing elements of this class.

Keywords:
Eight-node (hexahedron) solid-shell elements , Standard or partial Hu–Washizu functionals, Reduced representations of assumed stress/strain , RBF correction

Colabella L., Cisilino A.P., Fachinotti V., Kowalczyk P., An efficient strategy to implement local porosity constraints in the multiscale design of solids with parameterized biomimetic microstructures, COMPUTERS AND STRUCTURES, ISSN: 0045-7949, DOI: 10.1016/j.compstruc.2023.107084, Vol.285, pp.107084-1-107084-13, 2023

Abstract:
In previous works, the authors introduced a multiscale optimization method to maximize the stiffness of elastic solids with biomimetic cancellous microstructures described by a finite set of parameters. Although effective, the procedure is computationally expensive when solving large-scale problems using per-element non-linear constraints to impose local bounds on the solid volume fraction. This work improves the computational performance of the method by exploring two strategies to completely dispense with nonlinear local constraints: to bound the microparameters so the microsctructures are always within the solid fraction of trabecular bone, and to map the microparameters onto an auxiliary set of parameters that are linearly bounded. As a side effect, the design spaces are reduced. Such reductions are assessed in terms of the bulk and shear moduli and elastic symmetries, which are compared to those of natural bone. Performances of the two strategies are assessed by solving a series of benchmark problems and studying the stiffness of a hip prosthesis. The strategy based on the isoparametric mapping achieves the best results, performing up to 2000 times faster while marginally reducing the design space. Thus, the isoparametric mapping approach makes the multiscale design method a suitable tool for solving large-scale problems of practical interest.

Keywords:
Multiscale optimization , Trabecular bone , Parameterized microstructures , Computational performance , Large-scale problems

Garlinska M., Osial M., Proniewska K., Pregowska A., The Influence of Emerging Technologies on Distance Education, Electronics , ISSN: 2079-9292, DOI: 10.3390/electronics12071550, Vol.12, No.7, pp.1550-1-29, 2023

Abstract:

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Open AccessFeature PaperReview
The Influence of Emerging Technologies on Distance Education
by Magdalena Garlinska
1,†, Magdalena Osial
1 [ORCID] , Klaudia Proniewska
2,3 [ORCID] and Agnieszka Pregowska
1,*,† [ORCID]
1
Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawinskiego 5B, 02-106 Warsaw, Poland
2
Center for Digital Medicine and Robotics, Jagiellonian University Medical College, Kopernika 7E Str., 31-034 Krakow, Poland
3
Department of Bioinformatics and Telemedicine, Jagiellonian University Medical College, Medyczna 7 Str., 30-688 Krakow, Poland
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Electronics 2023, 12(7), 1550; https://doi.org/10.3390/electronics12071550
Received: 17 February 2023 / Revised: 22 March 2023 / Accepted: 23 March 2023 / Published: 25 March 2023
(This article belongs to the Special Issue Feature Papers in Computer Science & Engineering)
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Abstract
Recently, during the COVID-19 pandemic, distance education became mainstream. Many students were not prepared for this situation—they lacked equipment or were not even connected to the Internet. Schools and government institutions had to react quickly to allow students to learn remotely. They had to provide students with equipment (e.g., computers, tablets, and goggles) but also provide them with access to the Internet and other necessary tools. On the other hand, teachers were trying to adopt new technologies in the teaching process to enable more interactivity, mitigate feelings of isolation and disconnection, and enhance student engagement. New technologies, including Virtual Reality (VR), Augmented Reality (AR), Mixed Reality (MR), Extended Reality (XR, so-called Metaverse), Big Data, Blockchain, and Free Space Optics (FSO) changed learning, teaching, and assessing. Despite that, some tools were implemented fast, and the COVID-19 pandemic was the trigger for this process; most of these technologies will be used further, even in classroom teaching in both schools and universities. This paper presents a concise review of the emerging technologies applied in distance education. The main emphasis was placed on their influence on the efficiency of the learning process and their psychological impact on users. It turned out that both students and teachers were satisfied with remote learning, while in the case of undergraduate children and high-school students, parents very often expressed their dissatisfaction. The limitation of the availability of remote learning is related to access to stable Internet and computer equipment, which turned out to be a rarity. In the current social context, the obtained results provided valuable insights into factors affecting the acceptance and emerging technologies applied in distance education. Finally, this paper suggests a research direction for the development of effective remote learning techniques.

Keywords:
distance education, artificial intelligence (AI), virtual reality, augmented reality, mixed reality, free space optics (FSO), blockchain, big data

Tahani M., Postek E., Motevalizadeh L., Sadowski T., Effect of Vacancy Defect Content on the Interdiffusion of Cubic and Hexagonal SiC/Al Interfaces: A Molecular Dynamics Study, Molecules, ISSN: 1420-3049, DOI: 10.3390/molecules28020744, Vol.28, pp.744-763, 2023

Abstract:
The mechanical properties of ceramic–metal nanocomposites are greatly affected by the equivalent properties of the interface of materials. In this study, the effect of vacancy in SiC on the
interdiffusion of SiC/Al interfaces is investigated using the molecular dynamics method. The SiC reinforcements exist in the whisker and particulate forms. To this end, cubic and hexagonal SiC lattice polytypes with the Si- and C-terminated interfaces with Al are considered as two samples of metal matrix nanocomposites. The average main and cross-interdiffusion coefficients are determined using a single diffusion couple for each system. The interdiffusion coefficients of the defective
SiC/Al are compared with the defect-free SiC/Al system. The effects of temperature, annealing time, and vacancy on the self- and interdiffusion coefficients are investigated. It is found that the interdiffusion of Al in SiC increases with the increase in temperature, annealing time, and vacancy.

Keywords:
Interdiffusion,Diffusion coefficient,SiC/Al interface,Vacancy,Molecular dynamics

Abramowicz M., Osial M., Urbańska W., Walicki M., Wilczewski S., Pręgowska A., Skórczewska K., Jenczyk P., Warczak M., Pisarek M., Giersig M., Upcycling of Acid-Leaching Solutions from Li-Ion Battery Waste Treatment through the Facile Synthesis of Magnetorheological Fluid, Molecules, ISSN: 1420-3049, DOI: 10.3390/molecules28062558, Vol.28, No.6, pp.2558-1-2558-16, 2023

Abstract:
The rapidly growing production and usage of lithium-ion batteries (LIBs) dramatically raises the number of harmful wastes. Consequently, the LIBs waste management processes, taking into account reliability, efficiency, and sustainability criteria, became a hot issue in the context of environmental protection as well as the scarcity of metal resources. In this paper, we propose for the first time a functional material—a magnetorheological fluid (MRF) from the LIBs-based liquid waste containing heavy metal ions. At first, the spent battery waste powder was treated with acid-leaching, where the post-treatment acid-leaching solution (ALS) contained heavy metal ions including cobalt. Then, ALS was used during wet co-precipitation to obtain cobalt-doped superparamagnetic iron oxide nanoparticles (SPIONs) and as an effect, the harmful liquid waste was purified from cobalt. The obtained nanoparticles were characterized with SEM, TEM, XPS, and magnetometry. Subsequently, superparamagnetic nanoparticles sized 15 nm average in diameter and magnetization saturation of about 91 emu g−1 doped with Co were used to prepare the MRF that increases the viscosity by about 300% in the presence of the 100 mT magnetic fields. We propose a facile and cost-effective way to utilize harmful ALS waste and use them in the preparation of superparamagnetic particles to be used in the magnetorheological fluid. This work describes for the first time the second life of the battery waste in the MRF and a facile way to remove the harmful ingredients from the solutions obtained after the acid leaching of LIBs as an effective end-of-life option for hydrometallurgical waste utilization.

Keywords:
environment protection SPION, battery waste, toxic waste management, direct recycling, sustainability, circular economy, critical raw materials

Fathalian M., Postek E.W., Sadowski T., Mechanical and Electronic Properties of Al(111)/6H-SiC Interfaces: A DFT Study, Molecules, ISSN: 1420-3049, DOI: 10.3390/molecules28114345, Vol.28, No.11, pp.4345-1-19, 2023

Abstract:
A density functional theory (DFT) calculation is carried out in this work to investigate the effect of vacancies on the behavior of Al(111)/6H SiC composites. Generally, DFT simulations with appropriate interface models can be an acceptable alternative to experimental methods. We developed two modes for Al/SiC superlattices: C-terminated and Si-terminated interface configurations. C and Si vacancies reduce interfacial adhesion near the interface, while Al vacancies have little effect. Supercells are stretched vertically along the z-direction to obtain tensile strength. Stress–strain diagrams illustrate that the tensile properties of the composite can be improved by the presence of a vacancy, particularly on the SiC side, compared to a composite without a vacancy. Determining the interfacial fracture toughness plays a pivotal role in evaluating the resistance of materials to failure. The fracture toughness of Al/SiC is calculated using the first principal calculations in this paper. Young’s modulus and dominant surface energy are calculated to obtain the fracture toughness. Young’s modulus is higher for C-terminated configurations than for Si-terminated configurations. Surface energy plays a dominant role in determining the fracture toughness process. Finally, to better understand the electronic properties of this system, the density of states (DOS) is calculated.

Keywords:
DFT,interface,surface energy,young’s modulus,fracture toughness

Tahani M., Postek E.W., Sadowski T., Investigating the Influence of Diffusion on the Cohesive Zone Model of the SiC/Al Composite Interface, Molecules, ISSN: 1420-3049, DOI: 10.3390/molecules28196757, Vol.28, No.19, pp.6757-1-6757-19, 2023

Abstract:
Modeling metal matrix composites in finite element software requires incorporating a cohesive zone model (CZM) to represent the interface between the constituent materials. The CZM deter-mines the behavior of traction–separation (T–S) in this region. Specifically, when a diffusion zone is formed due to heat treatment, it becomes challenging to determine experimentally the equiva-lent mechanical properties of the interface. Additionally, understanding the influence of heat treatment and the creation of a diffusion zone on the T–S law is crucial. In this study, the molecular dynamics approach was employed to investigate the effect of the diffusion region formation, re-sulting from heat treatment, on the T–S law at the interface of a SiC/Al composite in tensile, shear, and mixed-mode loadings. It was found that the formation of a diffusion layer led to an increase in tensile and shear strengths and work of separation compared with the interfaces without heat treatment. However, the elastic and shear moduli were not significantly affected by the creation of the diffusion layer. Moreover, the numerical findings indicated that the shear strength in the diffu-sion region was higher when compared with the shear strength of the slip plane within the fcc aluminum component of the composite material. Therefore, in the diffusion region, crack propagation did not occur in the pure shear loading case; however, shear sliding was observed at the aluminum atomic layers.

Keywords:
metal matrix composite, diffusion, cohesive zone law, interface, molecular dynamics

Jočbalis G., Kačianauskas R., Borodinas S., Rojek J., Comparative numerical study of rate-dependent continuum-based plasticity models for high-velocity impacts of copper particles against a substrate, INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, ISSN: 0734-743X, DOI: 10.1016/j.ijimpeng.2022.104394, Vol.172, pp.1-14, 2023

Abstract:
The problem of high-rate elastic-plastic deformation of micro-sized copper particles impacting against a copper substrate was investigated by applying the continuum-based formulation and finite element thermomechanical analysis. Comparative study of selected plasticity models was performed. The aim of the paper was to study strain rate-dependant plasticity for a wide range of strain rates. The strain-rate-dependant Johnson-Cook and Cowper-Symonds models were studied by comparing displacements, velocities, strains, strain rates, stresses, contact forces, and temperatures and their contribution to material yield stress. The study shows the importance of the high-strain rate yielding model and its adequacy for experimental data. Both models complement each other and may be regarded as soft and hard bounds of the solution. A new, combined, two-function model, containing two independent functions for each of the two ranges, is suggested. The proposed model describes a low strain rate sensitivity range using the Johnson-Cook expression, while allows fitting of the model for experimental results in a high strain rate sensitivity range, using a modified Cowper-Symonds expression. This combination is capable of describing both low and high strain rate regimes, giving the minimum deviation from experimental results.

Keywords:
Finite element method, Thermomechanical analysis, High velocity particle impact, Continuum plasticity models, High strain-rate

Maździarz M., Transferability of interatomic potentials for silicene, Beilstein Journal of Nanotechnology, ISSN: 2190-4286, DOI: 10.3762/bjnano.14.48, Vol.14, pp.574-585, 2023

Abstract:
The ability of various interatomic potentials to reproduce the properties of silicene, that is, 2D single-layer silicon, polymorphs was examined. Structural and mechanical properties of flat, low-buckled, trigonal dumbbell, honeycomb dumbbell, and large honeycomb dumbbell silicene phases, were obtained using density functional theory and molecular statics calculations with Tersoff, MEAM, Stillinger–Weber, EDIP, ReaxFF, COMB, and machine-learning-based interatomic potentials. A quantitative systematic comparison and a discussion of the results obtained are reported.

Keywords:
2D materials, DFT, silicene, interatomic potentials, mechanical properties, force fields

Momeni-Khabisi H., Tahani M., Coupled thermal stability analysis of piezomagnetic nano-sensors and nano-actuators considering the flexomagnetic effect, EUROPEAN JOURNAL OF MECHANICS A-SOLIDS, ISSN: 0997-7538, DOI: 10.1016/j.euromechsol.2022.104773, Vol.97, pp.1-12, 2023

Abstract:
The current investigation deals with an analytical formulation and solution procedure for the thermal stability characteristics of piezomagnetic nano-sensors and nano-actuators considering the flexomagnetic effects and geometrical imperfection. Piezo-flexomagnetic nano-plate strips with the mid-plane initial rise are subjected to external uniform, linear, and nonlinear temperature rise loading across the thickness. The nonlinear size-dependent governing equations are derived within the framework of the first-order shear deformation plate theory, nonlocal strain gradient theory and considering the nonlinear von- Kármán strains. The proposed closed-form solutions and the obtained results are validated with the available data in the literature. The calculated buckling and post-buckling temperatures of piezo-flexomagnetic nano-plate strips are shown to be dependent on several factors including the scaling parameters, plate slenderness ratio, mid-plane initial rise, different temperature distributions, and scalar magnetic potential. The presented closed-form solutions and numerical results can serve as benchmarks for future analyses of piezo-flexomagnetic nano-sensors and nano-actuators.

Keywords:
Thermal buckling and post-buckling, Closed-form solution, Piezo-flexomagnetic plate strip, Size-dependent theories, Mid-plane initial rise

Pietrzyk-Thel P., Osial M., Pręgowska A., Abramowicz M., Nguyen Thu P., Urbańska W., Giersig M., SPIONs doped with cobalt from the Li-ion battery acid leaching waste as a photocatalyst for tetracycline degradation - synthesis, characterization, DFT studies, and antibiotic treatment, Desalination and Water Treatment, ISSN: 1944-3994, DOI: 10.5004/dwt.2023.29795, Vol.305, pp.155-173, 2023

Keywords:
Spent lithium-ion batteries, LiBs, Acid leaching, SPION, Magnetic nanomaterials, Metals recovery, Superparamagnetic, Waste management, Functional materials

Moneta J., Staszczak G., Grzanka E., Tauzowski P., Dłużewski P., Smalc-Koziorowska J., Formation of a-type dislocations near the InGaN/GaN interface during post-growth processing of epitaxial structures, JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/5.0128514, Vol.133, pp.045304-1-045304-12, 2023

Abstract:
Cross-sectional transmission electron microscopy studies often reveal a-type dislocations located either below or above the interfaces in
InGaN/GaN structures deposited along the [0001] direction. We show that these dislocations do not emerge during growth but rather are a
consequence of the stress state on lateral surfaces and mechanical processing, making them a post-growth effect. In cathodoluminescence mapping, these defects are visible in the vicinity of the edges of InGaN/GaN structures exposed by cleaving or polishing. Finite element cal-culations show the residual stress distribution in the vicinity of the InGaN/GaN interface at the free edge. The stress distribution is discussed in terms of dislocation formation and propagation. The presence of such defects at free edges of processed devices based on InGaN layers may have a significant negative impact on the device performance.

Keywords:
Luminescence ,Transmission electron microscopy ,Focused ion beam ,Semiconductor materials ,Epitaxy ,Crystal structure ,Crystal lattices ,Crystallographic defects,Mechanical stress,X-ray diffraction

Maździarz M., Transferability of interatomic potentials for germanene (2D germanium), JOURNAL OF APPLIED PHYSICS, ISSN: 0021-8979, DOI: 10.1063/5.0173745, Vol.134, No.18, pp.184303-1-184303-8, 2023

Abstract:
The capacities of various interatomic potentials available for elemental germanium, with the scope to choose the potential suitable for the modeling of germanene (2D germanium) allotropes,f were investigated. Structural and mechanical properties of the flat, low-buckled, trigonal dumbbell, and large honeycomb dumbbell single-layer germanium (germanene) phases, were obtained using the density functional theory and molecular statics computations with Tersoff, modified embedded atom method, Stillinger–Weber, environment-dependent interatomic potential, ReaxFF, and machine-learning-based interatomic potentials. A systematic quantitative comparative study and discussion of the findings are given.

Keywords:
Germanene, 2D materials, Interatomic potentials, Force fields, DFT, Mechanical properties

Dolega-Dolegowski D., Dolega-Dolegowska M., Pręgowska A., Malinowski K., Proniewska K., The Application of Mixed Reality in Root Canal Treatment, Applied Sciences, ISSN: 2076-3417, DOI: 10.3390/app13074078, Vol.13(7), No.4078, pp.1-18, 2023

Abstract:
The priority of modern dentistry is to keep patients’ teeth for as long as possible. Tooth extraction is a procedure performed as a last resort when conservative methods and endodontic surgery procedures have not brought the expected results. As a consequence, the number of patients in dental offices, who require first and repeated endodontic treatment, is increasing. Thus, the development of new technologies in the medical industry, including microscopy, computer tomography (CT), as well as diode and neodymium-YAG-erbium lasers, enables dentists to increase the percentage of successful treatments. Moreover, mixed reality (MR) is a very new technology, in which the 3D view can help plan or simulate various types of tasks before they will be carried out in real life. In dentistry, 3D holography can be applied to display CT data to plan endodontic treatment. The most important element in effective root canal treatment is the precise imaging of the root canal. The CT scans allow dentists to view the anatomy of the patient’s tooth with much higher precision and understanding than using 2D radiography (RTG-radiographic photo) pictures. Recently, the development of new 3D technologies allows dentists to obtain even more data from existing CT scans. In this paper, the CT scan data were applied to generate patient teeth in 3D and simulate the view of the root canal’s anatomy in MR devices, i.e., Microsoft HoloLens 2. Using DICOM RAW data from the CT exam, we generated a 3D model of the jaw with a tooth. In the next step, the crown of the tooth was removed in a similar way to how a dentist would do this using a dental handpiece. Furthermore, all root canals were cleaned of everything inside. This way we achieved empty tunnels, namely root canals. Finally, we added appropriate lighting, similar to the type of lighting that dentists use. The proposed approach enables to display of the root canals in the same way as during the endodontic procedure using a microscope. It allows for the visualization of the root canal and changing its direction, in which dimensional accuracy is crucial. It turns out that mixed reality can be considered a complementary method to the traditional approach, which reduces the amount of time for the root canal treatment procedure by up to 72.25%, depending on the complexity of the case, and increases its effectiveness. Thus, the mixed reality-based system can be considered an effective tool for planning dental treatment.

Keywords:
3D holography,root canal treatment,tooth,augmented reality,mixed reality

Osial M., Pregowska A., Warczak M., Giersig M., Magnetorheological fluids: A concise review of composition, physicochemical properties, and models, JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES, ISSN: 1045-389X, DOI: 10.1177/1045389X231157357, pp.1-21, 2023

Keywords:
Magnetorheological Fluids (MRF), rheology, smart materials, intelligent fluid, functional materials

Motevalizadeh L., Tahani M., A Phenomenological Study of Chromium Impurity Effects on Lattice Microstrains of SnO2 Nanoparticles Prepared Using Sol–Gel Technique, Crystals, ISSN: 2073-4352, DOI: 10.3390/cryst13060919, Vol.13, No.6, pp.919-12, 2023

Keywords:
Cr-doped SnO2, sol–gel, Williamson–Hall models, Halder–Wagner method, microstrains

Ostrowski M., Błachowski B., Wójcik B., Żarski M., Tauzowski P., Jankowski Ł., A framework for computer vision-based health monitoring of a truss structure subjected to unknown excitations, Earthquake Engineering and Engineering Vibration, ISSN: 1993-503X, DOI: 10.1007/s11803-023-2154-3, pp.1-17, 2023

Abstract:
Computer vision (CV) methods for measurement of structural vibration are less expensive, and their application is more straightforward than methods based on sensors that measure physical quantities at particular points of a structure. However, CV methods produce significantly more measurement errors. Thus, computer vision-based structural health monitoring (CVSHM) requires appropriate methods of damage assessment that are robust with respect to highly contaminated measurement data. In this paper a complete CVSHM framework is proposed, and three damage assessment methods are tested. The first is the augmented inverse estimate (AIE), proposed by Peng et al. in 2021. This method is designed to work with highly contaminated measurement data, but it fails with a large noise provided by CV measurement. The second method, as proposed in this paper, is based on the AIE, but it introduces a weighting matrix that enhances the conditioning of the problem. The third method, also proposed in this paper, introduces additional constraints in the optimization process; these constraints ensure that the stiff ness of structural elements can only decrease. Both proposed methods perform better than the original AIE. The latter of the two proposed methods gives the best results, and it is robust with respect to the selected coefficients, as required by the algorithm.

Keywords:
computer vision,structural health monitoring,physics-based graphical models,augmented inverse estimate,model updating,non-negative least square method