We demonstrate an InAs/GaAs quantum dot sQDd laser based on a strain-compensated, three-stack active region. Each layer of the stacked QD active region contains a thin GaP sDao=−3.8% d tensile layer embedded in a GaAs matrix to partially compensate the compressive strain of the InAs sDao=7% d QD layer. The optimized GaP thickness is ,4 MLs and results in a 36% reduction of compressive strain in...

A comprehensive study of optical transitions in direct bandgap Ge0.875Sn0.125 group IV alloys via photoluminescence measurements as a function of temperature, compressive strain and excitation power is performed. The analysis of the integrated emission intensities reveals a strain-dependent indirect-to-direct bandgap transition, in good agreement with band structure calculations based on 8 band...

Loading conditions and complex geometry have led the cylinder heads to become the most challenging parts of diesel engines. One of the most important durability problems in diesel engines is due to the cracks valves bridge area. The purpose of this study is a thermo-mechanical analysis of cylinder heads of diesel engines using a two-layer viscoelasticity model. The results of the thermo-mechani...

This paper presents an experimental investigation of two different magnetorheological (MR) fluids, namely water-based and hydrocarbon-based MR fluids in compression mode under various applied currents. Finite Element Method Magnetics was used to predict the magnetic field distribution inside the MR fluids generated by a coil. A test rig was constructed where the MR fluid was sandwiched between ...

Building waste is a critical issue in current construction. Innovative design strategies are required to reduce the depletion of valuable materials and resources through providing flexible and versatile structures. This study focuses on the development of an industrial, flexible, and demountable wall panel construction system. The panel system consists of concrete blocks with steel connectors t...

This work introduces Mg-4Zn-3Gd-1Ca/2ZnO (wt.%) nanocomposite fabricated using the technique of disintegrated melt deposition and extrusion. Addition of ZnO nanoparticles enhanced the compressive strengths of alloy by ~100 MPa. Nanocomposite samples display high strength and good ductility: 0.2% compressive yield stress of 355 MPa, ultimate compressive stress of 703 MPa, and compressive failure...

The permeability of scaffolds and other three-dimensional constructs used for tissue engineering applications is important as it controls the diffusion of nutrients in and waste out of the scaffold as well as influencing the pressure fields within the construct. The objective of this study was to characterize the permeability/fluid mobility of collagen-GAG scaffolds as a function of pore size a...

The anisotropic thermoelectric transport properties of bulk silicon strained in the [111]-direction were studied by detailed first-principles calculations focusing on a possible enhancement of the power factor. Electron and hole doping were examined in a broad doping and temperature range. At low temperature and low doping an enhancement of the power factor was obtained for compressive and tens...

Realistic simulations are increasingly demanded to clarify the dynamic behaviour of foam materials, because, on one hand, the significant variability (e.g. 20% scatter band) of foam properties and the lack of reliable dynamic test methods for foams bring particular difficulty to accurately evaluate the strain-rate sensitivity in experiments; while on the other hand numerical models based on ide...

The compressive properties of premium quality cocoa beans from Ghana considering the effect of moisture content in the moisture range of 7% to 22 % (w.b) were studied. The results of the study demonstrated that the displacement at maximum load or the deformation and the crushing energy had more positive linear function with moisture content and increased significantly from 0.80 mm to 1.87 mm an...