Channel temperature is a key parameter for accelerated life testing in GaN HEMTs. It is assumed that selfheating is similar in RF and DC operation and that DC test results can be applied to RF operation. We investigate whether this assumption is valid by using an experimentally calibrated, combined electrical and thermal model to simulate Joule heating during RF operation and compare this to DC...

soft-sphere discrete element method (dem) and navier-stokes equations were coupled with equations of energy for gas and solids to investigate the process of agglomeration in fluidized bed of polyethylene particles at high temperature. the newton’s second law of motion was adapted for translational and rotational motion of particles and agglomerates. the cohesive force for polyethylene particles...

We have used a two-dimensional drift-diffusion simulator, augmented by including accurate low-field mobility curves obtained by the Monte Carlo method, to study the operation of SiC MOSFETs both at room and high temperatures. A comparison with Si MOSFETs at room temperature is performed. Although drain current was higher in Si MOSFETs, SiC MOSFETs showed lower saturation conductance values. The...

We present fiber Bragg grating pressure sensors in air-hole microstructured fibers for high-temperature operation above 800 degrees C. An ultrafast laser was used to inscribe Type II grating in two-hole optical fibers. The fiber Bragg grating resonance wavelength shift and peak splits were studied as a function of external hydrostatic pressure from 15 psi to 2000 psi. The grating pressure senso...

To meet the demand for light sources for on-chip optical interconnections, we demonstrate the continuous-wave (CW) operation of photonic-crystal (PhC) nanocavity lasers at up to 89.8◦C by using InP buried heterostructures (BH). The wavelength of a PhC laser can be precisely designed over a wide range exceeding 100 nm by controlling the lattice constant of the PhC. The dynamic responses of the P...

The 98% response time of the membrane-covered Clark-type polarographic oxygen electrode may be reduced to 0.4 sec. by heating the electrode and the gas sample flowing past it to 80#{176} when the electrode is covered with 0.25-mu (6 ,) Teflon membrane. The design of the microcathode electrode has been modified slightly to prevent drying out of the electrolyte and pressure changes within the ele...

In a future massively parallel computing system with many processor elements (PEs), interconnection among the PEs would be a bottle-neck for improving system performance especially in the power consumption. For a highly parallel system, conventional electrical interconnection requires many high-speed switches that consume much electrical power, restricting the system performance. Concerning thi...

Abstract: A pulse-echo technique, based on ultrasonic "long-bar" mode (LBM) velocity measurements, working up to 1700°C is described. Magnetostrictive transducers and ultrasonic lines used in a 40-85 kHz frequency range are detailed. The conditions of choice of fundamental parameters (frequency, line geometry, sample size) are discussed in relation with the nature and the microstructure of ...

The computational paradigm known as quantum-dot cellular automata (QCA) encodes binary information in the charge configuration of Coulomb-coupled quantum-dot cells. Functioning QCA devices made of metal-dot cells have been fabricated and measured. We focus here on the issue of robustness in the presence of disorder and thermal fluctuations. We examine the performance of a semi-infinite QCA shif...

─The Nafion/zeolite composite membranes were synthesized for polymer electrolyte fuel cells (PEMFCs) by adding zeolite in the matrix of Nafion polymer. Two kinds of zeolites, Analcime and Faujasite, were used. The physicochemical properties of the composite membranes such as water uptake, ion-exchange capacity, hydrogen permeability, and proton conductivity were determined. The fabricated compo...