The performance enhancement of a SiGe:C HBT for RF/IF applications is described for Motorola’s 0.35μm and 0.18μm BiCMOS technologies. Cutoff frequencies (fT) have been improved from 50GHz to 78/84GHz (0.35/0.18μm BiCMOS), with a reduction in minimum noise figure (NF) from 0.7dB to 0.3dB. Improvements occurred through the optimization of the intrinsic collector and base dopant profiles, extrinsi...

recently, we have used the symmetric bracket of vector fields, and developed the notion of the symmetric derivation. using this machinery, we have defined the concept of symmetric curvature. this concept is natural and is related to the notions divergence and laplacian of vector fields. this concept is also related to the derivations on the algebra of symmetric forms which has been discus...

This paper reports on the impact that corrosion of stainless steel current collectors has performance fade a symmetric, carbon/carbon electrochemical capacitor, operating with an aqueous electrolyte (1 M Na2SO4). The results obtained by applying ageing protocols (voltage–holding tests) confirm collector positive electrode undergoes tremendous degradation during 200 h in charged state. To preven...

a new method of optimization on linear parabolic solar collectors using exergy analysis is presented. a comprehensive mathematical modeling of thermal and optical performance is simulated and geometrical and thermodynamic parameters were assumed as optimization variables. by applying a derived expression for exergy efficiency, exergy losses were generated and the optimum design and operating co...

In this paper we study curvature properties of semi - symmetric type of totally umbilical radical transversal lightlike hypersurfaces $(M,g)$ and $(M,widetilde g)$ of a K"ahler-Norden manifold $(overline M,overline J,overline g,overline { widetilde g})$ of constant totally real sectional curvatures $overline nu$ and $overline {widetilde nu}$ ($g$ and $widetilde g$ are the induced metrics on $M$...

Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. It is attributed to the formation of a very thin boundary layer at the absorber plate surface commonly known as viscous sub-la...

This paper presents the verification of a generational copying garbage collector for the CakeML runtime system. The proof is split into an algorithm proof and an implementation proof. The algorithm proof follows the structure of the informal intuition for the generational collector’s correctness, namely, a partial collection cycle in a generational collector is the same as running a full collec...

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...