Current driven instabilities in the collector of III–V heterojunction bipolar transistors ~HBT! are investigated. Numerical simulations indicate that in a modified AlGaAs/GaAs HBT the collector current shows oscillatory behavior due to the transferred-electron ~Gunn–Hilsum! effect. Influence of the Kirk effect as well as conditions for oscillation are discussed. © 1995 American Institute of Phy...

Recently, microwave performance has been reported for PNP InAlAs/InGaAs HBTs [1]. Although some simulations have been performed for the optimization of GaAs-based PNP HBTs [2], little has been reported on the optimization of PNP HBTs in the InP material system. In this work, various layer structures for InAlAs/InGaAs PNP HBTs were simulated using a 2dimensional drift-diffusion simulator in orde...

We demonstrate a mesoscopic spin polarizer/analyzer system that allows the spin polarization of current from a quantum point contact in a large in-plane magnetic field to be measured. A transverse electron focusing geometry is used to couple current from an emitter point contact into a collector point contact. At large in-plane fields, with the point contacts biased to transmit only a single sp...

The computer simulation program of a practical scale reverse electrodialysis process has been developed based on the program for saline water electrodialysis. The program is applied to compute the performance of an industrial-scale reverse electrodialysis stack (effective membrane area S = 1 m × 1 m = 1 m2, cell pair number N = 300 pairs). The stack operatingconditions are optimized. Seaw...

Advanced bipolar transistors play a vital role in RF/Microwave applications. But they need to satisfy stringent demands on device performance parameters such as β, gm, and fT. Many of the bipolar technologies developed to meet these demands are vertical structures and suffer from many non−ideal effects at high collector current densities. In the present work, to enhance the performance limits o...

The garbage collector presented in this paper makes use of two well known compaction garbage collection algorithms with very diierent performance characteristics: Cheney's two-space copying collector and Jonker's sliding compaction collector. We propose a scheme which allows either collector to be used. The run-time memory requirements of the program being executed are used to determine the mos...

Environmental degradation and Economic growth are two important proofs in sustainable development which are followed by steel industry. In this case, energy and environmental damages as sustainability patterns of environment have been investigated in three different dust collectors to select the most environmentally suitable dust collector for electric furnace. In this article, the consumption ...

The electrical and magnetic properties of the spin-valve transistor (SVT) are investigated as a function of transistor size. A new fabrication process, designed to study the size dependence of the SVT properties, uses: silicon-on-insulator (SOI) wafers, a combination of ion beam and wet etching and a negative tone photoresist (SU8) as an insulating layer. The Si/Pt emitter and Si/Au collector S...

Lithium metal is one of the most attractive anode materials for electrochemical energy storage. However, the growth of Li dendrites during electrochemical deposition, which leads to a low Coulombic efficiency and safety concerns, has long hindered the application of rechargeable Li-metal batteries. Here we show that a 3D current collector with a submicron skeleton and high electroactive surface...

This study compares environmental and economic impacts of using nanofluids to enhance solar collector efficiency as compared to conventional solar collectors for domestic hotwater systems. Results show that for the current cost of nanoparticles the nanofluid based solar collector has a slightly longer payback period but at the end of its useful life has the same economic savings as a convention...