Search

• 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]

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]

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]

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: 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]