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A geometrical approach is constructed to explain the dependence of lattice thermal conductivity (LTC) in InAs/GaAs multi-layered superlattice structures (SLs). The Morelli–Callaway model is applied to calculate the LTC of InAs/GaAs SLs with the assumption of InAs+GaAs thickness as a grain boundary and the total layer thickness as the sample size. Calculations gave a systematically conventional temperature dependence of LTC for nine different samples depending on their number of layers and the InAs and GaAs layer thicknesses having their ratio from 0.13 to 0.295. The dependence of LTC for both peak values at the low and room temperature were examined according to sample size, number of layers and layer thickness ratio. A new relation is examined for the assessment of the grain boundary effects. The best dependence of LTC was obtained by introducing the effects of the layer thickness ratio (InAs/GaAs) and the sample size D in the form [D/(InAs/GaAs)] which gave a systematic mathematical fitting equation.

Introduction: The purpose of this study was to ascertain the primary ex vivo biomechanical stability of a novel bioabsorbable magnesium alloy (ZX00: Mg–Zn–Ca) bone anchor in human cadaveric proximal humeri, indicated in the reconstruction of the rotator cuff.

Methods: Twenty human Thiel-embalmed cadaveric humeri were prepared and freed from soft tissue. One $\varnothing$5.7 × 20.5-mm ZX00 anchor and one $\varnothing$5.5 mm × 16.3 mm Arthrex Titanium FT Corkscrew (ATC) control anchor were inserted into the footprint of the supraspinatus tendon, 15 mm apart. The humeri were mounted onto a material testing machine and following a 40 N preload, cyclic loading was performed over 400 cycles. If the construct remained intact, ultimate load to failure (ULTF) was measured using an increasing axial load of 1 mm/s, ULTF and mode of failure were recorded.

Results: No difference was found in the ability to withstand cyclic loading, mode or load-to-failure strengths between ZX00 and control anchors. The maximum tractional force loaded for the ZX00 anchors had a median of 257.4 N (range 165.3–328.2). The corresponding value for the ATC anchors averaged 239.9 N (range 118.9–306.7).

Conclusion: ZX00 alloy anchors appear to provide adequate initial biomechanical stability when compared to an industry-standard control in a cadaveric rotator cuff repair model.

This paper reviews recent Monte Carlo simulations within the empirical potential approach, which give insights into fundamental aspects of the bulk and surface structure of group-IV semiconductor alloys containing carbon. We focus on the binary Si_1-xC_x and ternary Si_1-x-yGe_xC_y alloys strained on silicon substrates. The statistical treatment of these highly strained alloys is made possible by using the semigrand canonical ensemble. We describe here improvements in the algorithm which considerably speed up the method. We show that the identity switches, which are the basic ingredients in this statistical ensemble, must be accompanied by appropriate relaxations of nearest neighbors in order to reach "quasiequilibrium" in metastable systems with large size mismatch between the constituent atoms. This effectively lowers the high formation energies and large barriers for diffusion which make molecular dynamics methods impractical for this problem. The most important findings of our studies are: (a) The prediction of a repulsive Ge–C interaction and of a preferential C–C interaction in the lattice. (b) The prediction for significant deviations of the structural parameters and of the elastic constants from linearly interpolated values (Vegard's law). As a result, for a given amount of carbon, strain compensation is shown to be more drastic than previously thought. (c) Investigation of the surface problem shows that the competition between the reconstruction strain field and the preferential arrangement of carbon atoms leads to new complicated structural patterns.

We use the self-consistent, augmented space recursion technique to study the electronic structure and magnetic properties of alloys of the transition metal Fe with the noble metals Cu, Ag and Au. We analyze the effect of hybridization between the constituent bands on the electronic and magnetic properties.

The electronic band structure of AlN, AlSb, AlAs and their ternary alloys with In has been investigated by ETB. The ETB method has been formulated for sp³d² basis and nearest neighbor interactions of the compounds and its energy parameters have been derived from the results of the present first principles calculations carried on AlN, AlSb and AlAs. It has been found that the present ETB energy parameters can produce the band structure of the compounds and their ternary alloys with In successfully.

Self-formation of MgO or Al₂O₃ surface layer on CuMg or CuAl alloys by annealing in H₂ gas was investigated theoretically and experimentally. Theoretical consideration shows that Mg or Al can segregate to the surface of Cu during the annealing, while the enrichment ability is much stronger for Mg. Meanwhile, the MgO or Al₂O₃ surface layer is self-formed by the preferential reaction of Mg or Al with O₂ remnant in H₂ atmosphere. The Al₂O₃ surface layer is expected to play a role in passivating the surface of Cu. However, the MgO layer would suffer failure in passivating the surface due to incorporation of Cu and fissures formed in MgO during the annealing process. Our theoretical predictions are in agreement with experimental observations.

First principles total energy calculations have been performed using full potential linear augmented plane wave method (FP-LAPW) within density functional theory to study the structural, electronic and optical properties of MgS_xSe_1-x, MgS_xTe_1-x and MgSe_xTe_1-x alloys in the rock salt crystallographic phase. The generalized gradient approximation parameterization scheme has been used for calculating the ground state structural parameters and their deviation from the Vegard's law has been discussed. Full relativistic electronic band structures and density of states have been calculated to study the electronic properties of the end binary compounds and ternary alloys MgS_xSe_1-x, MgS_xTe_1-x and MgSe_xTe_1-x (0.25 < x < 0.75). Optical bowing for these semiconductor alloys has been discussed in term of volume deformation, electronegativity and structural relaxation. Optical properties of the binary and ternary magnesium chalcogenides have been calculated in terms of the complex dielectric function and the results are compared with available theoretical and experimental data.

First-principles calculations are performed to study the structural, electronic, thermodynamic and thermal properties of the InP and InAs bulk materials and InAs_xP_1-x ternary alloys using the full potential-linearized augmented plane wave method (FP-LAPW) within the density functional theory (DFT). The dependence of the lattice constant, bulk modulus, band gap, Debye temperature, heat capacity and mixing entropy on the composition x was analyzed. The lattice constant for InAs_xP_1-x alloys exhibits a marginal deviation from the Vegard's law. A large deviation of the bulk modulus from linear concentration dependence (LCD) was observed for our alloys. We found that the composition dependence of the energy band gap is almost linear by using the mBJ and EV-GGA approximations. The microscopic origins of the gap bowing were explained and detailed by using the approach of Zunger and co-workers. Furthermore, the calculated phase diagram shows a miscibility gap for these alloys with a high critical temperature. Thermal effects on some macroscopic properties of InAs_xP_1-x alloys are predicted using the quasi-harmonic Debye model, in which the phononic effects are considered. This is the first quantitative theoretical prediction of the thermal properties of the InAs_xP_1-x alloys, and we still expect the confirmation of experimental studies.

Various properties of substitutional alloys formed from aluminium and the platinum group metals (PGMs) are examined using density functional (D-F) theory and show strong variations depending on metal type. A similar pattern for the binary alloys is observed using molecular dynamics modeling employing Sutton Chen potentials. All results suggest that several of the PGMs could have superior properties to the presently used Ni₃Al alloy for high temperature applications. Some phases are predicted to be stable with extremely high melting temperatures (MTs).

Hydride formation in metals (e.g. in Pd), accompanied by a hysteresis loop in the absorption isotherms, is one of the generic examples of first-order phase transitions (FOPTs). During the last decade, the corresponding experimental studies, driven by applications related to hydrogen storage, have shifted towards metal particles sized from a few nanometers to micrometers in general and to alloyed particles of these sizes in particular. The understanding of hydride formation in alloys is, however, still far from complete. Herein, a statistical model of hydride formation in a random alloy is presented. The model is focused on the situation when this process is favorable in metal 1 (e.g. Pd) and shows what may happen when atoms of metal 2 make it less favorable due to decrease of the hydrogen binding energy and/or attractive hydrogen–hydrogen (H–H) interaction. Random distribution of metal atoms is taken explicitly into account. The attractive H–H interaction, including its dependence on fraction of metal 2 in the alloy, is described at the mean-field level. With increasing fraction of the latter metal, the critical temperature is found to decrease linearly or nonlinearly depending on the values of the model parameters. If the decrease of the hydrogen binding energy with increasing number of nearest-neighbor (nn) atoms of metal 2 is appreciable, the model predicts up to three hysteresis loops.

In the present study, the effect of ytterbium (Yb) addition on the microstructure and tensile properties of Mg-5Al alloys was investigated. Experimental results showed that the microstructure of the Mg-5Al alloy consisted mainly of α-Mg and Mg₁₇Al₁₂ phases. In addition, an Al₂Yb phase was newly formed on the grain boundaries and its volume percent was increased with increasing Yb content. The tensile strength, yield strength and elongation were decreased at ambient temperature with increasing Yb content. At elevated temperature, however, the tensile strength and yield strength were significantly improved while the elongation was decreased.

In the present work, the electrochemical behavior of Mg-xCe-1Zn (x = 3, 8 and 13wt.%) alloys have been investigated. The alloys were fabricated by using a vacuum induction melting method under an argon atmosphere. Potentiodynamic polarization was carried out in 3.5% NaCl solution of pH 7.2 at room temperature to evaluate the corrosion properties of Mg-xCe-1Zn (x = 3, 8 and 13wt.%) alloys. The microstructure of the Mg-(3, 8 and 13wt.%)Ce-1Zn alloys were mainly consisted of α-Mg and eutectic Mg₁₂Ce phase. With the increase of Ce contents, the volume percent and size of the eutectic Mg₁₂Ce phase were increased. Results indicated that the corrosion rate of Mg-xCe-Zn alloy was increased by the excessive Ce addition.