In-plane InGaAs/Ga(As)Sb nanowire based tunnel junctions grown by selective area molecular beam epitaxy

In-plane InGaAs/Ga(As)Sb heterojunction tunnel diodes are fabricated by selective area molecular beam epitaxy with two different architectures: either radial InGaAs core / Ga(As)Sb shell nanowires or axial InGaAs/GaSb heterojunctions. In the former case, we unveil the impact of strain relaxation and alloy composition fluctuations at the nanoscale on the tunneling properties of the diodes, whereas in the latter case we demonstrate that template assisted molecular beam epitaxy can be used to achieve a very precise control of tunnel diodes dimensions at the nanoscale with a scalable process. In both cases, negative differential resistances with large peak current densities are achieved.

Theoretical analysis of the factors, influencing composition uniformity of the cadmium zinc telluride substrates grown by THM

The effect of the sample composition, variation of the temperature field and the feed material non-homogeneity on uniformity of the growing crystal is considered. It is shown that optimization of the solvent composition makes it possible to minimize the jump of the ZnTe concentration at the seed/crystal boundary. The composition fluctuations at variation of the thermal field during crystal growth are smooth enough and relatively non-significant. The feed composition distribution has, as a rule, a random character. Different harmonics of composition distribution non-uniformity in the feed material differently affect the homogeneity of the growing crystal. Longwave non-uniformities in the feed transform into the growing crystal almost completely. At the wavelength equals to a half of the solvent length or shorter, the perturbations of the growing crystal composition are relatively small. Evidently, the cause of the local composition variations, found in real crystals, is, basically, the feed composition non-uniformities

The mass balance model perfectly fits both Hall et al. underfeeding data and Horton et al. overfeeding data

Background & Aims Recently, the validity of mass balance model (MBM) was questioned based on two feeding studies. Thus, we simulated both of these feeding trials. Methods MBM describes the temporal evolution of body weight and body composition under a wide variety of feeding experiments. This computational study simulated, utilizing MBM, the underfeeding trial by Hall et al. (Cell Metab. 2015;22:427-36) and the overfeeding trial by Horton et al. (Am J Clin Nutr. 1995;62:19-29). Results Our simulation results indicate that data from both of these feeding trials perfectly match MBM-based predictions, i.e., MBM gives a remarkably accurate description of experimental data. Conclusions It is becoming increasingly clear that our model (MBM) is perfectly able to predict body weight and body composition fluctuations under a wide variety of feeding experiments.

Phase equilibrium and dielectric relaxation in mixture of 5CB with dilute dimethyl phthalate: effect of coupling between orientation and composition fluctuations on molecular dynamics in isotropic one-phase state

Phase equilibrium and dielectric relaxation were examined for mixtures of liquid-crystalline (LC)-forming 4-cyano-4′-pentylbiphenyl (5CB) with dilute dimethyl phthalate (DMP).

Fuel-Adaptability Analysis of Intermediate-Temperature-SOFC/Gas Turbine Hybrid System With Biomass Gas

The tolerance and adaptability to various kinds of fuels make intermediate-temperature solid oxide fuel cell (IT-SOFC) and gas turbine (GT) hybrid system one of the most attractive technologies in the future energy market. In this paper, based on a detailed model established on matlab/simulink, a thermodynamic analysis of IT-SOFC/GT hybrid system fueled with different types of biomass gases is presented. During the process of this research, the composition fluctuations of CH4, H2, CO, CO2, N2, and H2O are considered to simulate the practical situation. Operating states of IT-SOFC/GT hybrid system fueled with wood chip gasified gas and farm biogas are compared under the same power scale of 180 kW. Performance and safety evaluations of hybrid system in response to composition fluctuations of wood chip gas and farm biogas are carried out. Results show that the hybrid system can reach an efficiency of 60.78% with wood chip gas and 59.09% with farm biogas. Meanwhile, with each composition of wood chip gas varying from 80% to 120%, the IT-SOFC/GT hybrid system could maintain the electrical efficiency higher than 59%. However, in the case of farm biogas, the efficiency of system drops to as low as 55%. It is also found that composition fluctuations of H2 in wood chip gas and CH4 in farm biogas leave the most significant effects on system performance. For safety consideration, fluctuation range of CH4 in farm biogas should be controlled between 86% and 116%; otherwise, failure of gas turbine would occur due to unsafe operating temperatures. Compared with wood chip gas, operation of IT-SOFC/GT hybrid system with farm biogas requires more water vapor available to prevent failure of the reformer due to carbon deposition.

Morphology, Hardness and Wear Properties of Plasma Cladding NiCrCu Coating on M2 High-Speed Steel

To improve the cutting performance, the red hardness and wear resistance of M2 high-speed steel, as well as expand the application field, in this work, a coating was fabricated via plasma cladding on M2 high-speed steel using Ni, Cr and Cu alloy elements as precursor materials. The distribution and composition of alloying elements, microhardness and wear resistance of the coating were studied. The results show that the NiCrCu cladding layer contains many types of carbides. The secondary hardening caused by the dispersion of carbides can significantly improve the hardness, red hardness and wear resistance of material. The hardness of cladding layer is above 950 HV, after holding at 600 °C for 4 h, the hardness is above 932 HV. The alloy elements are evenly distributed, but, due to the rapid solidification after the cladding, there are composition fluctuations in the longitudinal direction. The wear resistance of the cladding layer is excellent; the wear rate is reduced from 1.75 to 1.44 × 10−6 mm3 N−1 m−1 or less; and the wear mechanism is a combination of abrasive wear and adhesive wear.