Free convection and mass transfer flow of non-newtonian fluid with thermal diffusion effect

An analytical study is performed to examine the thermal diffusion characteristics of free convection and mass transfer flow in a non-Newtonian fluid (Walters, 1962: liquid B') past a uniformly accelerated infinite vertical plate in the presence of thermal diffusion. The expression for the velocity field is obtained by the Laplace transform technique. The influence of the Soret number (a thermal diffusion parameter) on the velocity field is extensively discussed with the help of graphs.     

Countercurrent water-heating system with a heat exchanger in a solar energy collector loop

The counter current heat exchanger theory with periodic inlet temperatures has been applied to analyze the thermal performance of a water heating system. The theoretical results obtained are in agreement with the experimental data reported in the literature.     

On the reliability of electrostatic NEMS/MEMS devices: Review of present knowledge on the dielectric charging and stiction failure mechanisms and novel characterization methodologies

This paper reviews the state of the art knowledge related to critical failure mechanisms in electrostatic micro- and nano-electromechanical systems (MEMS and NEMS) which are the dielectric charging and stiction. It describes also the recent employed nanoscale characterization techniques for these phenomena based on Kelvin probe force microscopy (KPFM) and force–distance curve measurements. The influence of relative humidity and dielectric deposition conditions on the charging/discharging processes is discussed. Moreover, different stiction mechanisms induced by electrostatic force and/or meniscus formation are analyzed. Finally, novel characterization methods are presented and used to correlate between the results from MEMS devices and metal–insulator–metal (MIM) capacitors. These methods are employed in view of application in electrostatic capacitive MEMS switches and could be easily extended to explore other NEMS/MEMS devices. The study provides an accurate understanding of the charging and stiction related failure mechanisms, presents guidelines for a proper packaging environment, and reveals precise explanations for the literature reported device level measurements of electrostatic MEMS devices.     

$$E^{2} SR^{2}$$ E 2 S R 2 : An acknowledgement-based mobile sink routing protocol with rechargeable sensors for wireless sensor networks

Wireless Networks - The advances in hardware manufacturing technologies and wireless communications enabled the evolution of tiny, multi-functional, low-power and resource constrained sensor nodes...     

Influence of Abrasive Properties on Residual Stresses in Lapped Ferrite and Alumina

The effect of abrasive-particle properties on surface-finishing residual stresses, surface finish, and material removal rates during the lapping of ferrite and aluminium oxide is quantified experimentally. It is shown that lapping with softer abrasives and smaller particles results in lower compressive residual stresses near the surface and improved surface finish. These results demonstrate possible methods for controlling surface finishing residual stresses in ceramics while at the same time achieving dimensional accuracy.     

Leakage power analysis and reduction during behavioral synthesis

This paper presents a high-level leakage power analysis and reduction algorithm. The algorithm uses device-level models for leakage to precharacterize a given register-transfer level module library. This is used to estimate the power consumption of a circuit due to leakage. The algorithm can also identify and extract the frequently idle modules in the datapath, which may be targeted for low-leakage optimization. Leakage optimization is based on the use of dual threshold voltage (V/sub T/) technology. The algorithm prioritizes modules giving a high-level synthesis system an indication of where most gains for leakage reduction may be found. We tested our algorithm using a number of benchmarks from various sources. We ran a series of experiments by integrating our algorithm into a low-power high-level synthesis system. In addition to reducing the power consumption due to switching activity, our algorithm provides the high-level synthesis system with the ability to detect and reduce leakage power consumption, hence, further reducing total power consumption. This is shown over a number of technology generations. The trend in these generations indicates that leakage becomes the dominant component of power at smaller feature size and lower supply voltages. Results show that using a dual-V/sub T/ library during high-level synthesis can reduce leakage power by an average of 58% for the different technology generations. Total power can be reduced by an average of 15.0%-45.0% for 0.18-0.07 /spl mu/m technologies, respectively. The contribution of leakage power to overall power consumption ranges from 22.6% to 56.2%. Our approach reduced these values to 11.7%-26.9%.     

L(j, k)-Labelings of Kronecker Products of Complete Graphs

For positive integers j ges k, an L(j, k)-labeling of a graph G is an integer labeling of its vertices such that adjacent vertices receive labels that differ by at least j and vertices that are distance two apart receive labels that differ by at least k. We determine lambda^j _k(G) for the case when G is a Kronecker product of finitely many complete graphs, where there are certain conditions on j and k. Areas of application include frequency allocation to radio transmitters.     

An optimal fuzzy system for color image enhancement.

A Gaussian membership function is proposed to fuzzify the image information in spatial domain. We introduce a global contrast intensification operator (GINT), which contains three parameters, viz., intensification parameter t, fuzzifier fh, and the crossover point mu(c), for enhancement of color images. We define fuzzy contrast-based quality factor Qf and entropy-based quality factor Qe and the corresponding visual factors for the desired appearance of images. By minimizing the fuzzy entropy of the image information with respect to these quality factors, the parameters t, fh, and mu(c) are calculated globally. By using the proposed technique, a visible improvement in the image quality is observed for under exposed images, as the entropy of the output image is decreased. The terminating criterion is decided by both the visual and quality factors. For over exposed and under plus over exposed images, the proposed fuzzification function needs to be modified by taking maximum intensity as the fourth parameter. The type of the images is indicated by the visual factor which is less than 1 for under exposed images and more than 1 for over exposed images.     

Automatic Test Generation for Combinational Threshold Logic Networks

We propose an automatic test pattern generation (ATPG) framework for combinational threshold networks. The motivation behind this work lies in the fact that many emerging nanotechnologies, such as resonant tunneling diodes (RTDs), single electron transistor (SET), and quantum cellular automata (QCA), implement threshold logic. Consequently, there is a need to develop an ATPG methodology for this type of logic. We have built the first automatic test pattern generator and fault simulator for threshold logic which has been integrated on top of an existing computer-aided design (CAD) tool. These exploit new fault collapsing techniques we have developed for threshold networks. We perform fault modeling, backed by HSPICE simulations, to show that many cuts and shorts in RTD-based threshold gates are equivalent to stuck-at faults at the inputs and output of the gate. Experimental results with the MCNC benchmarks indicate that test vectors were found for all testable stuck-at faults in their threshold network implementations.     

Analysis of the Effect of Ground Plane Size on the Performance of a Probe-fed Cavity Resonator Microstrip Antenna

In this paper, a probe-fed rectangular microstrip patch antenna with partially reflective superstrate at terahertz frequency (600 GHz) has been analyzed and simulated. The analysis of the partially reflective surface shows the highly reflective property of the surface over the wideband of the frequencies. The analysis of a specific configuration (rectangular patch) of partially reflective surface predicts the directivity of antenna to be the order of 24 dBi and subsequently it has been validated with the simulation. The proposed antenna has been simulated by using commercially available CST Microwave Studio simulator based on finite integral technique. Next to this, the application scenario of this kind of the antenna in the terahertz regime of the electromagnetic spectrum has been discussed and it has been obtained that this antenna is capable to establish 9 m long communication link.