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• Explored 3T-APTSC to overcome single-junction solar cell limitations, especially the SQ limit. • Demonstrated the superiority of three-terminal tandems, optimizing current matching and allowing independent adjustments. • Optimized PV parameters for 3T-APTSC: V OC 3.76 V, J SC 10.70 mA/cm2, FF 69.00 %, PCE 26.24 %. Despite numerous publications on two-junction tandems using SCAPS-1D simulation, there is a gap in research regarding three-junction tandems. This paper explores the advantages of three junction all-perovskite tandem solar cells (3J-APTSC) where we introduce a new methodology utilizing two-step filtered spectrum and current matching techniques in SCAPS-1D to design realistic tandem solar cells. Crucial steps involve determining filtered spectrum and current matching points among sub-cells for tandem optimization. Our designed three-terminal tandem solar cell exhibits promising photovoltaic parameters, including V OC : 3.76 V, J SC : 10.70 mA/cm2, FF: 69.00 %, and PCE: 26.24 %, achieved through optimized active layer thicknesses. This thorough examination of 3J-APTSC offers insights that could drive the future development of highly efficient tandem solar cells. [ABSTRACT FROM AUTHOR]

• Double truncated tetrahedral tensegrity (DTTT) structure is firstly introduced. • DTTT exhibits superior energy absorption compared to traditional truss lattices. • DTTT with relative density of 12% displays the optimal mechanical performances. In this paper, we studied a double truncated tetrahedron tensegrity (DTTT) structure. A experiment and simulation investigation were made to explore the compressibility of DTTT structure. Firstly, the relative density of the structure is controlled by the thickness of the bar, and to control the relative density to explore its impact on structural compression performance. The results show that DTTT structure has the best compression performance when the relative density is 12%. Under these conditions, FCC and Kelvin structures are introduced as contrast groups. The results show that DTTT structure exhibits excellent energy absorption performance, average crushing force performance and crushing force efficiency performance, and the crushing efficiency performance is higher than 36% of FCC, more than 42% of Kelvin. [ABSTRACT FROM AUTHOR]

Abstract: Interdependencies within and among Critical Infrastructures (CIs), e.g., between Industrial Control Systems (ICSs), in particular Supervisory Control and Data Acquisition (SCADA) system, and the underlying System Under Control (SUC), have dramatically increased the overall complexity of related systems, causing the emergence of unpredictable behaviors and making them more vulnerable to cascading failures. It is vital to get a clear understanding of these often hidden interdependency issues and tackle them with advanced modeling and simulation techniques. In this paper, vulnerabilities due to interdependencies between these two exemplary systems (SCADA and SUC) are investigated and analyzed comprehensively using a modified five-step methodical framework. Furthermore, suggestions for system performance improvements based on the investigation and analysis results, which could be useful to minimize the negative effects and improve their coping capacities, are also presented in this paper. [Copyright &y& Elsevier]

Highlights • A mesoscopic simulation program is developed to simulate the mechanical behaviors of frost-damaged concrete. • Prediction model of damaged compressive strength is proposed based on the parametric study. • Calculation models of other material characteristics of frost-damaged concrete are also given. • The deteriorated compressive and tensile constitutive relationships are proposed and verified. Abstract Frost action is one of the significant factors for deterioration of concrete structures in cold and wet regions. To evaluate the effects of freezing-thawing environment on the structural performance of reinforced concrete structures, it is important to know the degradation of concrete materials such as strength, stiffness, ductility, and so on. In order to investigate the mechanical behaviors of concrete under the effect of frost damage including deformation as well as strength, a two-dimensional mesoscopic Rigid Body Spring Model has been proposed previously. In current paper, a systematic study was conducted to simulate and analyze the frost-damaged concrete. Behavior under mechanical loading including uniaxial compression and tension is simulated on non-air-entrained concrete model after a full process of freezing-thawing cycles is simulated. The deteriorated properties such as compressive strength, tensile strength, elastic modulus, etc. are evaluated and parametric study is conducted. Then, a macroscale prediction model was proposed based on the mesoscale simulation results and it considered different environmental factors which varied among different laboratory experiments. The proposed model could predict the strength degradation in compression and tension of concrete with the number of FTCs which was also verified by numerous experimental results. Besides, pursuant to the existing constitutive models for non-damaged concrete, stress-strain relationships in compression and tension for frost-damaged concrete were developed according to the simulation results and several test data by mathematical regression. Satisfactory correlation was found through the comparisons between analytical and experimental results to show the applicability of the models in studying the structural performance of reinforced concrete structures. [ABSTRACT FROM AUTHOR]

The Ti6Al4V alloy is one of the most commonly used in orthopedic surgery. Mechanical property of implant contributes important biological functions for load-bearing bone tissue reconstruction. There is a significant need for design and fabrication of porous scaffold with customized mechanical properties for bone tissue engineering. In this paper, bionic design and fabrication of porous implants were studied by using finite element analysis (FEA) and 3D printing techniques. Novel porous architectures were built up with diamond lattice pore structure arraying units. With finite element analysis, the structure weak points under pressure were simulated so that the mechanical properties of the implants were optimized. Porous implants with different porosities and mechanical properties were precisely fabricated by selected laser melting (SLM), one of powder bed fusion additive manufacturing techniques. The biocompatibility and repair effect were studied by in vivo experiments. Animal results indicated that the damaged load-bearing bones were well reconstructed. New generated bones embedded and fitted into the designed porous implants. The optimized design and precisely manufactured implants are conducive to bone tissue repair and reconstruction. [ABSTRACT FROM AUTHOR]

In this paper, a technique has been developed to estimate intrinsic small signal parameters of submicron SiC MESFETs, designed for high power microwave applications. In the developed technique, small signal parameters are extracted by involving drain-to-source current, I ds instead of Schottky barrier depletion layer expression. It has been demonstrated that in SiC MESFETs, the depletion layer gets modified due to intense transverse electric field and/or self-heating effects, which are conventionally not taken into account. Thus, assessment of AC small signal parameters by employing depletion layer expression loses its accuracy for devices meant for high power applications. A set of expressions for AC small signal elements has been developed using I ds and its dependence on device biasing has been discussed. The validity of the proposed technique has been demonstrated using experimental data. [ABSTRACT FROM AUTHOR]

The nanoscale pores in shale oil and gas are often filled with external nanomaterials to enhance wellbore stability and improve energy production. And there has been considerable research on discrete element blocking models and simulation about nanoparticles. However, nanomaterials are not just nanoparticles and there are few researches on fiber-based discrete element dynamics sealing calculations. Moreover, nanofibers have better sealing efficiency relative to nanoparticles. In this paper, a fiber-based discrete element fluid-solid coupling sealing model was established to clarify the dynamic migration and sealing process of nanofibers in shale pores. The innovative nanofiber model guarantees real-time force deformation and bendability during nanofiber flow process. The factors influencing sealing efficiency on shale pores with fiber concentration, aspect ratio, diameter, density, stiffness, rotation and Poisson's ratio have been conducted. Furthermore, the simulation results with and without fiber were certified by theoretical and experimental results which increased the credibility and applicability. Results indicate that the sealing efficiency increases by 69.40%, 139.12%, and 254.89%, respectively, as the fiber concentration increases from 0.5% to 1%, 1.5% and 2%. The increase in sealing efficiency is not linear for fiber concentration. The sealing efficiency is almost the highest as the ratio of aspect ratio is 1:15 in the initial stage of sealing. And fiber diameter with 1/15 of the pore outlet diameter is a reasonable choice if economical applicability is considered based on the sealing process. Furthermore, practice has proved that the sealing effect of bendable fibers is increased by 14.50% compared with non-bendable fibers. The bending of the fiber can improve the efficiency of shale pore sealing. And the research can provide theoretical and technical support for the nanofiber optimization of sealing nanopores of shale oil and gas. • Fluid-structure coupled nano model based on shale pores and fiber was presented. • Sealing effect with fiber concentration, aspect ratio and diameter are conducted. • Innovative nanofiber bending mode was proposed to ensure simulation accuracy. • The plugging influence of different nanofiber characteristics were discussed. • The simulation results were certified by theoretical and experimental results. [ABSTRACT FROM AUTHOR]

Micro-scale strain distribution, an integrated response of microstructural parameters, is crucial to designing the microstructure of two-phase titanium alloys. In this paper, a microstructure-based finite element model is used to analyze the effect of microstructural parameters, such as volume fraction and distribution of primary α (α p ), yield stress of transformed β (β t ) on micro-scale strain distribution of two-phase titanium alloys. Strain distribution factor (SDF) is proposed to quantitatively characterize the strain distribution. It is found that with increasing SDF the homogeneity of strain distribution increases. Decreasing yield stress of β t and increasing volume fraction of α p will increase SDF, whereas directional distribution of α p will significantly decrease SDF. An SDF window for different α p volume fractions and β t yield stress is constructed, guiding the microstructural design of two-phase titanium alloy. [ABSTRACT FROM AUTHOR]

In this paper, we have studied structural and magnetocaloric properties of La 0.8 Sr x Ca 0.2− x MnO 3 system with x = 0.05, 0.1 and 0.15. X-ray diffraction (XRD) indicates that samples with x = 0.05 and x = 0.1 crystallize in an orthorhombic structure in Pnma space group, whereas the sample with x = 0.15 crystallize in the rhombohedral structure with R 3 ¯ c space group. The field dependence of magnetocaloric properties of manganite La 0.8 Sr x Ca 0.2− x MnO 3 undergoing first order phase transition is investigated using a phenomenological model. The magnetic entropy change of the samples varies from 1.01 J/kg K for x = 0–1.57 J/kg K for x = 0.15 under the applied magnetic field of 12 kOe. These results indicate that the present compounds are one of candidate materials for magnetic refrigerators near room temperature. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Eutectics in Al-Co, Co-Cr, Mg-Hg, Mg-Sb systems are explained by dual-cluster model. • HCP solid solutions with similar atomic radii are formulated: [cluster](glue atom) 3. • Dual-cluster formula for an HCP-related eutectic is [two clusters](glue atom) 4 or 6. • The nearest-neighbor cluster for an HCP structure is a twinned cuboctahedron. Abstract Eutectic compositions have been previously solved by a dual-cluster model which regards the eutectic liquid as two structural units issued from the relevant eutectic phases. However, this rule is not generally obeyed in eutectics involving elemental solid solutions. The present paper addresses the composition interpretation of binary eutectics in Al-Co, Co-Cr, Mg-Hg, and Mg-Sb systems, which are characterized by nearly equal atomic radii of the two elements and by the involvement of one eutectic phase with hexagonal close-packed structure. The universal cluster formula for hexagonal close-packed solid solutions is calculated following the cluster-plus-glue-atom model, in which any short-range-order structure is described by a structural unit composed of a nearest-neighbor cluster (twinned cuboctahedron for hexagonal close-packed phase) plus a few next-neighbor glue atoms. According to our calculations, for solutes and solvents in the similar size, which is the present case, the number of glue atoms is 3 for hexagonal close-packed solid solutions, formulated as [twinned cuboctahedron](glue atom) 3. Thus, the dual-cluster formulas for the related eutectic points are established: two clusters from the relevant eutectic phases plus 4 or 6 glue atoms (the number of glue atoms is 1 or 3 for the other eutectic phase), well matching the experimentally measured eutectic compositions. [ABSTRACT FROM AUTHOR]

This paper presents an improved model to simulate I - V characteristics of submicron SiC MESFETs, designed for microwave power applications. The proposed model adequately addresses a non-ideal Schottky behavior, commonly observed in submicron devices, by adjusting the device biasing through simulation variables. Swarm optimization technique has been applied to investigate gate length ( L g ) dependent performance of various SiC MESFETs models. It has been found that the proposed model provides an improved accuracy, ranging from 7% to 24%, compared to the best models available in the literature. This enhanced performance is primarily associated with the extra control, provided by the proposed model to simulate the movement of the depletion region in the channel as a function of applied voltages. An attempt has been made to identify the location underneath the Schottky barrier gate, where the depletion region gets its maximum height and thus controls the saturation current of the channel. Physical and electrical parameters of various SiC MESFETs having L g = 0.4 μm, 0.5 μm, 0.6 μm and 0.7 μm have also been assessed. An accurate assessment of the physical parameters of the device exhibits the validity of the model for submicron SiC MESFETs. [ABSTRACT FROM AUTHOR]

Knowledge gained from computer simulations in new earth-related technologies is not limited to the scientific community itself but impacts other domains of society such as politics, business and industry, and the public at large. In general business and industry in the oil and gas business are using computer simulations on a daily basis. In this case it is using computer simulations to gain understanding of the risk of a new technology which would affect the subsurface on a large scale and hence in Europe a substantial amount of people. So far, research did not consider in depth patterns of in silico science for policy. This paper analyses how policy-makers process and use simulation data based on a case-study of geo-scientific carbon dioxide capture modeling. The empirical results are based on 19 qualitative interviews with decision-makers from politics, business and industry, and society. The empirical results reveal a great variety of co-existing perception, evaluation and use patterns of how decision-makers deal with simulations. The field work reveals that the current state-of-the-art in research literature which emphasizes an overall misperception, misunderstanding and misuse of simulation data by policy-makers is, in general, not backed by the case-study results. However, scientific simulations do leave considerable room for misunderstandings for experts not disposing on specific geo-scientific and simulation expertise. [ABSTRACT FROM AUTHOR]

The present paper proposes a novel method based on Schmid׳s law by introducing a calculation of "Normalized Schmid factor" as an indispensable criterion for predicting twin variant selection in commercially pure titanium. Through comparing the calculation with experimental results, this novel method is proved to be a more effective criterion than Schmid׳s law and the accuracy is about 90% during primary, secondary and tertiary twinning variant selection. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a computer model is established to simulate the microstructure of magnesia-phosphate cement paste at the micro-scale. The chemical reaction in the paste is analyzed first, based on which the microstructure is modeled through interacted growing and eroding spherical particles representing the solid phases. The pore structure of the simulated paste is characterized by a closing operation based algorithm. It is found that the simulated pore size distribution curves are consistent with corresponding experimental results. [Copyright &y& Elsevier]

Running-in wear is very important from the operational view point of a mechanical component in tribological and other machining operations such as polishing and finishing. Two important parameters undergo severe changes during the running-in viz wear rate and surface roughness. Numerous wear models have been proposed to estimate the wear volume and wear rate as a function of running-in time. This paper presents a model to relate the wear rate with the change of surface roughness during running-in. The power law model developed was validated by experiments performed on EN-31 steel. In order to evaluate the competence of the proposed model statistical parameters-mean absolute percentage error (MAPE) and coefficient of determination (R 2 ) were used. It was concluded that the model is adequate and wear rate strongly depends on the surface roughness. [ABSTRACT FROM AUTHOR]

Recent investigations have shown that the steady state grain size of severely deformed materials is dependent on the stacking fault energy. In this paper, a model is presented to investigate such a dependency which uses thermodynamics based calculations. The present model shows that the relationship between the steady state grain size and the stacking fault energy of material is in power law form, directly. Furthermore, the model shows that the steady state grain size has an exponential relationship with the self-diffusion activation energy and a decrease in the self-diffusion activation energy increases the steady state grain size. The model predictions are in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports a new model for a wireless microsensor data acquisition system that can be used in diagnosing abnormalities in the esophagus. The proposed system incorporates pressure sensors for measuring the strength and pattern of muscle contractions that occur in the esophagus. Real data recorded by a manometry device, that detects pressure changes using developed sensors within a sealed cavity, is employed to assess the performance of the proposed system. Three different pulse coding modulation (PCM) and successive approximation register (SAR) analog to digital conversion algorithms are used for the channel coding. The created models were simulated and tested using SIMULINK® software. A behavioral model for FSK transceiver suitable for short-range applications has been developed. The transceiver system performance was tested under different conditions and the output simulation results were presented. The obtained output results from the different models are discussed. [Copyright &y& Elsevier]

Abstract: In order to find a simple and efficient simulation for plasma spray process, an attempt of modeling was made to calculate velocity and temperature field of the plasma jet by hexagonal 7-bit lattice Boltzmann method (LBM) in this paper. Utilizing the methods of Chapman–Enskog expansion and multi-scale expansion, the authors derived the macro equations of the plasma jet from the lattice Boltzmann evolution equations on the basis of selecting two opportune equilibrium distribution functions. The present model proved to be valid when the predictions of the current model were compared with both experimental and previous model results. It is found that the LBM is simpler and more efficient than the finite difference method (FDM). There is no big variation of the flow characteristics, and the isotherm distribution of the turbulent plasma jet is compared with the changed quantity of the inlet velocity. Compared with the velocity at the inlet, the temperature at the inlet has a less influence on the characteristics of plasma jet. [Copyright &y& Elsevier]

Abstract: When plasma is used to spray coatings on a mould surface, the states of the plasma jet and powder particles have great influence on the quality of the spray layer. In order to find a simple and efficient simulation for the states of the plasma jet and powder particles, an attempt of modeling was made by hexagonal 7-bit Lattice Boltzmann method (LBM) and a probabilistic algorithm in this paper. The velocity and temperature field of the plasma jet and particles are calculated and compared with those obtained by previous models and measurements. The dynamic moving process, accelerating course, maximal speed and distribution of powder particles are calculated by the present model. The optimal spraying distance and deposition efficiency under different spraying conditions are also acquired. It can be concluded that the combined model is competent for numerical simulation of the atmospheric plasma spraying. Simulation by LBM is simpler and faster than that by traditional methods. LBM is also a computational method that offers flexibility and outstanding capacity of parallel computation. [Copyright &y& Elsevier]

Abstract: A merge is a point of a highway where two or more streams of traffic flow into one. It is always easy to solve the demand–supply problem at a merge when the merge is operating under uncongested condition. However, when congestion backs up exceeding the merging point where multiple streams of traffic meet, one is typically faced with splitting downstream supply among the merging branches. Solutions of this situation are multiple and several merge queuing models have been proposed in the past. To address the drawbacks of the past models, this paper proposes a capacity-based weighted fair queuing (CBWFQ) model that is characterized by its fidelity (approximation to real situation), simplicity, and extensibility. Based on the CBWFQ merge queuing model, a simplified kinematic wave model is formulated to model traffic operation at a merge bottleneck. [Copyright &y& Elsevier]

Abstract: The relationship between most common doped elements and type of deformation mechanism in Ti was considered. The generalized stacking fault energy for pure and doped Ti has been calculated using density functional theory. It is shown that the deformation tendency caused by emission of partial dislocations varies with the C, H, O, and N additions and increases in all of the considered elements. The twinnability of Ti is also modified by the presence of interstitial atoms. The results presented in the paper suggest that H addition decreases and C increases twin generation in comparison with pure titanium. [Copyright &y& Elsevier]

Abstract: This paper studies the freezing of Co clusters with diameters ranging from 2.52 to 4.62nm by using molecular dynamics simulation with an embedded atom method. It was found that the frozen structures are closely related to cluster sizes. When the cluster size is small (≤2.94nm), an icosahedron is formed. When the cluster size is large (≥3.79nm), an hcp bulk-like structure is formed. If the cluster size is 3.37nm, a decahedron is formed. It was also found that the frozen structure is strongly dependent on the energy of geometric shapes at given sizes. The size-dependent frozen structures of clusters provide a new method for fabricating novel materials with nano microstructures. [Copyright &y& Elsevier]