Repeater insertion in crosstalk‐aware inductively and capacitively coupled interconnects

This paper reveals that repeater insertion not only reduces propagation delay but also reduces crosstalk level in coupled interconnects. Repeaters can therefore be efficiently utilized for reduction in propagation delay and crosstalk noise at a trade‐off marginal increase in power dissipation. Conventionally, Power Delay Product (PDP) criterion is used to insert repeaters into long interconnects. A new criterion, the Power‐Delay‐Crosstalk‐Product (PDCP), is introduced as an efficient condition, to insert repeaters into long coupled interconnect. Various criteria, such as minimum delay, minimum PDP and minimum PDCP, are applied for achieving optimum repeater insertion. The performance of PDCP criterion is compared with PDP criterion in terms of optimum number of repeaters, power dissipation, propagation delay and crosstalk for a wide range of coupling combinations. It is observed that instead of PDP criterion, PDCP criterion is best suited for the determination of optimum number of repeaters for overall minimization of delay, power and crosstalk. Copyright © 2010 John Wiley & Sons, Ltd.     

Modeling non-uniform frost growth on a fin-and-tube heat exchanger

A semi-empirical model that predicts non-uniform frost growth on heat exchangers is developed and experimentally validated. The model is based on a scaling approach that uses the average frost layer properties to predict growth in a quasi-steady state, heat and mass balance based segment-by-segment coil simulation. The air redistribution algorithm in the model improved frost thickness predictions by 20%-50% and coil capacity predictions by 42% compared to the same model without air redistribution. The model along with an empirical frost delay predicted the frost thickness for different inlet refrigerant temperatures, air relative humidities and air velocities under non-uniform frosting with a root mean square error of 3.7%, 9.8% and 5.2% respectively.     

Crosstalk analysis in CNT bundle interconnects for VLSI application

Crosstalk noise voltage levels have been estimated at the far end of a victim line in capacitive coupled single‐walled carbon nanotube (SWCNT) bundle interconnects under the influence of interconnect dimensions. The reported work on crosstalk analysis in SWCNT bundle interconnects to date have assumed the value of coupling capacitance as equivalent to the coupling effect between metal interconnects of same dimensions. In this paper, we propose an improved model to extract inter‐bundle real‐life coupling capacitances to fill that gap. A similar analysis is performed for a copper‐based interconnect, and comparison is made with result obtained for CNT‐based interconnect at 22‐nm technology. SPICE simulation results reveal that the crosstalk noise voltage level at the far end of the victim line in CNT bundles is significantly lower than that in conventional metal (copper) conductors in three different cases, keeping the pitch fixed but varying the value of interconnect spacing and width. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Biochemical and nutritional changes in fish proteins during drying

Biochemical and nutritional changes in the muscle proteins of a lean marine fish Nempiterus japonicus during drying at 50, 60 and 70°C were investigated. Solubility of proteins in water, 0.6 M NaCl, 1.5 M urea, 8 M urea and 10 g litre^?1 sodium dodecyl sulphate (SDS) decreased as drying progressed at all three temperatures; most of the decrease occurring in the initial 4 h of drying SDS-polyacrylamide gel electrophoresis of 1.5 M urea, 8 M urea and SDS extracts showed that higher molecular weight (MW) protein fractions were more sensitive to drying and disappeared much earlier from electropherograms than the lower MW protein fractions. Residual solubility of proteins near the pH range of 4–6 was found to increase during drying, but solubility at acid and alkaline pH was adversely affected. Decrease of solubility by drying was more affected at acid pH, especially at higher temperatures than at alkaline pH. Sulphydryl groups registered a regular and sharp decrease with drying except at 50°C, where initially an increase was observed. Apart from disulphide and hydrophobic bonds, free amino groups also appear to be involved in denaturation reactions during drying. Pepsin digestibility of fish muscle decreased slightly during drying but a clear relationship with drying temperature was not evident. Highly significant differences in proteins between protein efficiency ratio (PER), net protein utilisation (NPU) and biological value were observed between the drying temperatures. The PER and NPU of fish dried at 60°C were significantly higher than those dried at 50 or 70°C.     

A multi-wall carbon nanotube tower electrochemical actuator

Patterned multiwall carbon nanotube arrays up to four millimeters long were synthesized using chemical vapor deposition. Electrochemical actuation of a nanotube array tower was demonstrated in a 2 M NaCl solution at frequencies up to 10 Hz with 0.15% strain using a 2 V square wave excitation. The synthesis and electrochemical modeling approach outlined in the paper provide a foundation for the design of nanotube smart materials that actuate and are load bearing.     

An algorithm to determine sample sizes for optimization with artificial neural networks

This article presents an algorithm developed to determine the appropriate sample size for constructing accurate artificial neural networks as surrogate models in optimization problems. In the algorithm, two model evaluation methods—cross‐validation and/or bootstrapping—are used to estimate the performance of various networks constructed with different sample sizes. The optimization of a CO₂ capture process with aqueous amines is used as the case study to illustrate the application of the algorithm. The output of the algorithm—the network constructed using the appropriate sample size—is used in a process synthesis optimization problem to test its accuracy. The results show that the model evaluation methods are successful in identifying the general trends of the underlying model and that objective function value of the optimum solution calculated using the surrogate model is within 1% of the actual value. © 2012 American Institute of Chemical Engineers AIChE J, 59: 805–812, 2013     

Physics & Modeling of Ambipolar Snapback Behavior in Gate Grounded NMOS

Silicon - This paper models first snapback ambipolar action in NMOS, when subjected to high current stress across the drain terminal. We analyze 2 − D ambipolar current in Gate Grounded NMOS...     

Transport properties of graphene oxide nanofiltration membranes: Electrokinetic modeling and experimental validation

There is a need for developing reliable models for water and solute transport in graphene oxide (GO) membranes for advancing their emerging industrial water processing applications. In this direction, we develop predictive transport models for GO and reduced-GO (rGO) membranes over a wide solute concentration range (0.01–0.5 M) and compositions, based on the extended Nernst–Planck transport equations, Donnan equilibrium condition, and solute adsorption models. Some model parameters are obtained by fitting experimental permeation data for water and unary (single-component) aqueous solutions. The model is validated by predicting experimental permeation behavior in binary solutions, which display very different characteristics. Sensitivity analysis of salt rejections as a function of membrane design parameters (pore size and membrane charge density) allows us to infer design targets to achieve high salt rejections. Such models will be useful in accelerating structure-separation property relationships of GO membranes and for separation process design and optimization.     

Synthesis,characterization, and tunable adsorption and diffusion properties of hybrid ZIF‐7‐90 frameworks

Hybrid zeolitic imidazolate frameworks (ZIFs), containing more than one type of imidazolate linker, can allow highly tunable molecular sieving and adsorption. Their crystallization becomes more challenging when the end‐member (single‐linker) ZIFs crystallize in different crystal systems. We demonstrate the controlled synthesis and detailed characterization of hybrid ZIF‐7‐90 frameworks containing linkers of ZIF‐7 (rhombohedral) and ZIF‐90 (cubic). ZIF‐7‐90 materials with SOD‐type topology are obtained in three crystalline phases depending on the linker composition and synthesis technique. The effect of synthesis conditions on the activation‐induced phase transition from rhombohedral to other topologies is studied. Nitrogen physisorption at 77 K and CO₂ physisorption at 273 K shows the tunability of the pore‐size distribution and the framework flexibility as a function of framework composition. Measurements of water adsorption and butane isomer diffusion illustrate the tunability of diffusivity over seven orders of magnitude and control of hydrophobic to hydrophilic adsorption behavior. © 2015 American Institute of Chemical Engineers AIChE J, 62: 525–537, 2016     

Quality grading for cervical smears

Three thousand five hundred and eighty cervical smears were taken in 1990-1992 at a Genitourinary Medicine Clinic with various spatula or spatula brush combinations. The unsatisfactory rate and the detection of cellular abnormalities showed some relation to spatula type. However, the satisfactory smears screened in the laboratory are routinely assigned a quality grade-good, fair or poor. Analysis shows higher rate of detection of cellular abnormalities in good quality smears, the detection of dyskaryosis being twice as high, in contrast to the fair or poor quality smears. It is suggested that quality grade is a better way of classifying smear quality in the cervical screening programmes rather than the presence or absence of endocervical and/or metaplastic cells.