Crosstalk reduction in mixed-signal 3-D integrated circuits with interdevice layer ground planes

We show nearly 8 dB of crosstalk reduction using ground planes between active device layers in three-dimensional (3-D) integrated circuits. Our experimental work utilizes two planes of MOS transistors with tungsten or polysilicon ground planes designed to attenuate crosstalk. Theoretical simulations, using an electromagnetic solver, and the experimental results are consistent with analytical results. The key result verified is that a ground plane, whose footprint shadows the device area, is sufficiently large for effective attenuation. The interdevice layer ground plane provides an effective means to achieve crosstalk reduction in 3-D mixed-signal/RF integration because of simple fabrication and high coupling isolation.     

Simplified loss analysis and comparison of full-bridge,full-range-ZVS DC-DC converters

The loss of zero-voltage-switching (ZVS) of active switches has been a serious limitation of full-bridge (FBZVS) converters. Many techniques have been proposed in the past to extend the range of ZVS operation over the wider and also the full range of operation. However, in these techniques ZVS is achieved at the expense of additional conduction loss in active switches and losses in the auxiliary components. In this paper, the analysis for the additional losses in various full-range FBZVS DC-DC converters and their comparative evaluation is reported. Closed form expressions are derived for average value of device currents and losses. The loss curves for various topologies are plotted and compared. The analytical results are found to be consistent with the experimental efficiency tests performed on 500 W, 100 kHz prototype. It is concluded that a recently proposed new topology has the least penalty of additional losses.     

Electron microscopic observations of Bi and Tl bearing cuprate high temperature superconductors

The second generation of high temperature superconductors typified by Bi₂Sr₂Ca _n−1Cu _n O_2n+4 and Tl₂Ba₂Ca _n−1Cu _n O_2n+4 exhibits curious structural properties which have direct relevance to the superconducting behaviour particularly transition temperature (T _c ). The present paper reports on investigations of structural properties at microlevel in Bi-bearing HTCS. We have found curious structural characteristics which manifests itself in the form of transformation froma _p ×a _p ×c to (2)^1/2 a _p ×(2)^1/2 a _p ×c through the loss of calcium atoms and the formation of five-fold modulated phase alongb through the loss of Ca and Sr atoms. We have also found the evidence of high periodicities (n=4) Bi₂Sr₂Ca₃Cu₄O₁₂. The microstructural characteristics of HTCS showing the higherT _c (R=0) ∼ 120 K exhibits unusual characteristics.     

Bioactive Carbohydrates and Peptides in Foods: An Overview of Sources,Downstream Processing Steps and Associated Bioactivities

Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production processes. This review discusses the health benefits and bioactivities associated with peptides and carbohydrates of natural origin and downstream processing methodologies and novel processes which may be used to overcome these.     

Superconductivity at 4 K in Pd-Deficient Layered Ta2Pd x S6

In the present short letter, we report on the low dimensional 4d and 5d transition metals-chalcogenide based compounds i.e., Ta2PdxS6, showing semiconducting to superconducting transition at around 4K with their upper critical fields outside the Pauli paramagnetic limit. It seems couple of different superconducting phases do exist in these new set of compounds. Our short letter in this regards is thought provoking, asking to explore various unearthed possible new superconducting phases in (Nb/Ta)2Pdx(S/Se/Te)y systems.     

Efficient solutions to various routing issues involved in mobile ad hoc bio-sensor networks: applying appropriate motion trajectories

Ad hoc bio-sensor networks have a very characteristic structure with three types of nodes: the command centre, the sensor nodes (animals such as rats) and the relaying nodes. We have taken up such networks and measured the throughput of such systems and suggest ways in which the throughput can be increased. It was also found that to increase the throughput of such systems, no sophisticated routing techniques or expensive transmission techniques are needed. This can be achieved by simply adopting the appropriate motion trajectories of the nodes. We have also explained the structure of these networks in detail and the routing issues involved in these networks. A Hot-Spot problem at the command centre has also been discussed. The suggestions of appropriate motions target this problem and show how an even distribution of nodes can alleviate this problem to a large extent. In addition to this, a constraint on the number of messages the sensor node can send per unit time can also make the network more efficient.     

Near optimal process plan selection for multiple jobs in networked based manufacturing using multi-objective evolutionary algorithms

The networked manufacturing offers several advantages in current competitive atmosphere by way of reducing the manufacturing cycle time and maintenance of the production flexibility, thereby achieving several feasible process plans. In this paper, we have addressed a Multi Objective Problem (MOP) which covers-minimize the makespan and to maximize the machine utilization while generating the feasible process plans for multiple jobs in the context of network based manufacturing system. A new multi-objective based Territory Defining Evolutionary Algorithm (TDEA) to resolve the above computationally challenge problem have been developed. In particular, with two powerful Multi-Objective Evolutionary Algorithms (MOEAs), viz. Non-dominated Sorting Genetic Algorithm (NSGA-II) and Controlled Elitist-NSGA-II (CE-NSGA-II) the performance of the proposed TDEA has been compared. An illustrative example along with three complex scenarios is presented to demonstrate the feasibility of the approach. The proposed algorithm is validated and the results are analyzed and compared.     

Optimization of number of collectors for integrated PV/T hybrid active solar still

The aim of this paper is to optimize the number of collectors for PV/T hybrid active solar still. The number of PV/T collectors connected in series has been integrated with the basin of solar still. The optimization of number of collectors for different heat capacity of water has been carried out on the basis of energy and exergy. Expressions of inner glass, outer glass and water temperature have been derived for the hybrid active solar system. For the numerical computations data of a summer day (May 22, 2008) for Delhi climatic condition have been used. It has been observed that with increase of the mass of water in the basin increases the optimum number of collector. However the daily and exergy efficiency decreases linearly and nonlinearly with increase of water mass. It has been observed that the maximum yield occurs at N = 4 for 50 kg of water mass on the basis of exergy efficiency. The thermal model has also been experimentally validated.     

Physics-of-failure assessment of a cruise control module

The purpose of a cruise control system is to accurately maintain the driver’s desired set speed, without intervention from the driver, by actuating the throttle-accelerator pedal linkage. Over the past five years, owners of a particular cruise control have complained that it did not operate properly. Complaints ranged from not engaging upon command, to the cruise unexpectedly accelerating past the desired speed. A common thread among all the complaints was the intermittent nature of the problems. More than 96% of the reported failed modules removed from vehicles and returned to the company, passed bench tests.This paper presents a physics-of-failure process to identify, induce and analyze failure mechanisms causing intermittent failures, high warranty returns and cannot duplicate (CND) problems of the digital electronic cruise control module (CCM). In addition, we explain why the manufacturer’s tests were not representative of the actual automotive environments, nor were they conducted in a manner to access actual failures. We conclude with a recommendation for a physics-of-failure approach for future product development.     

Effect of thermal storage on the performance of greenhouse

In this communication, thermal model of a greenhouse has been developed by incorporating the effect of water wall in the north side. Various temperatures, namely plant, water wall and room temperatures as a function of climatic and design parameters have been obtained by solving coupled single-order differential equation using Runge–Kutta method. Numerical methods have been carried out for a typical day of winter for Delhi condition. It has been observed that there is significant effect in the plant, room air and water temperatures due to change in fraction of solar radiation incident on north wall (F_n) and heat capacity of water wall. Experimental validation of the proposed model for a greenhouse with brick north wall has also been carried out. It has been observed that there is a fair agreement between experimental and theoretical values. Copyright © 2002 John Wiley & Sons, Ltd.