SiGe heterojunction bipolar transistors (HBTs) have been fabricated using selective epitaxy for the Si collector, followed in the same growth step by nonselective epitaxy for the p SiGe base and n-Si emitter cap. DC electrical characteristics are compared with cross-section TEM images to identify the mechanisms and origins of leakage currents associated with the epitaxy in two different types o...

We analyze the performance of several copying garbage collection algorithms in a large address space offered by modern architectures. In particular, we describe the design and implementation of the RealOF garbage collector, an algorithm explicitly designed to exploit the features of 64-bit environments. This collector maintains a correspondence between object age and object placement in the add...

A solar-driven Stirling engine is modelled as a combined system which consists of a solar collector and a Stirling engine. The performance of the system is investigated, based on the linearized heat loss model of the solar collector and the irreverisible cycle model of the Stirling engine affected by finite-rate heat transfer and regenerative losses. The maximum efficiency of the system and the...

Solar Energy Applications Laboratory , Colorado State University . Fort Collins , CO 80523 Design of a vapor transport solar water heater using R-123 is optimized to maximize thermal performance and minimize life cycle cost. Optimal systems for one and twostory homes are identified in a parametric study of collector area, condenser heat transfer area, water storage tank volume and circulating r...

Conical stromatolites are thought to be robust indicators of the presence of photosynthetic and phototactic microbes in aquatic environments as early as 3.5 billion years ago. However, phototaxis alone cannot explain the ubiquity of disrupted, curled, and contorted laminae in the crests of many Mesoproterozoic, Paleoproterozoic, and some Archean conical stromatolites. Here, we demonstrate that ...

We present a method for the generation of high kinetic energy attosecond electron packets via magnetostatic and aperture filtering of conical surface plasmon (SP) accelerated electrons. The conical SP waves are excited by coupling an ultrafast radially polarized laser beam to a conical silica lens coated with an Ag film. Electromagnetic and particle tracking models are employed to characterize ...

This paper proposes an efficient network architecture to improve energy consumption in Wireless Sensor Networks (WSN). The proposed architecture uses a mobile data collector to a partitioned network. The mobile data collector moves to center of each logical partition after each decision period. The mobile data collector must declare its new location by packet broadcasting to all sensor node...

This paper proposes an efficient network architecture to improve energy consumption in Wireless Sensor Networks (WSN). The proposed architecture uses a mobile data collector to a partitioned network. The mobile data collector moves to center of each logical partition after each decision period. The mobile data collector must declare its new location by packet broadcasting to all sensor node...

abstract: the present study deals with the buckling analysis of the laminated composite truncated conical sandwich shells with flexible core subjected to combined axial compressive load and external pressure. higher order governing equations of the motion are presented for conical composite sandwich shells, where they are derived from the hamilton principle. then, by the use of improved higher-...