Design methodologies for high-performance noise-tolerant XOR-XNOR circuits

Scaling down to deep submicrometer (DSM) technology has made noise a metric of equal importance as compared to power, speed, and area. Smaller feature size, lower supply voltage, and higher frequency are some of the characteristics for DSM circuits that make them more vulnerable to noise. New designs and circuit techniques are required in order to achieve robustness in presence of noise. Novel methodologies for designing energy-efficient noise-tolerant exclusive-OR-exclusive- NOR circuits that can operate at low-supply voltages with good signal integrity and driving capability are proposed. The circuits designed, after applying the proposed methodologies, are characterized and compared with previously published circuits for reliability, speed and energy efficiency. To test the driving capability of the proposed circuits, they are embedded in an existing 5-2 compressor design. The average noise threshold energy (ANTE) is used for quantifying the noise immunity of the proposed circuits. Simulation results show that, compared with the best available circuit in literature, the proposed circuits exhibit better noise-immunity, lower power-delay product (PDP) and good driving capability. All of the proposed circuits prove to be faster and successfully work at all ranges of supply voltage starting from 3.3 V down to 0.6 V. The savings in the PDP range from 94% to 21% for the given supply voltage range respectively and the average improvement in the ANTE is 2.67X.     

Scheduling data transfers in a network and the set scheduling problem

In this paper we consider the online ftp problem. The goal is to service a sequence of file transfer requests given bandwidth constraints of the underlying communication network. The main result of the paper is a technique that leads to algorithms that optimize several natural metrics, such as max-stretch, total flow time, max flow time, and total completion time. In particular, we show how to achieve optimum total flow time and optimum max-stretch if we increase the capacity of the underlying network by a logarithmic factor. We show that the resource augmentation is necessary by proving polynomial lower bounds on the max-stretch and total flow time for the case where online and offline algorithms are using same-capacity edges. Moreover, we also give polylogarithmic lower bounds on the resource augmentation factor necessary in order to keep the total flow time and max-stretch within a constant factor of optimum.     

Stability of a deflagration front in compressible media

A two-dimensional linear analysis of the planar flame front stability for a compressible fluid is presented. The analysis shows that there are two types of perturbations. The first type, corresponding to waves in incompressible media, has already been studied by Landau. It predicts absolute instability of the flame front. The second type of perturbations is due to fluid compressibility and the dependence on upstream flow parameters of the flame front velocity. Three different regimes for these perturbations are possible: stable, acoustically unstable, and absolutely unstable. The instability results in a pronounced pressure wave generation.A one-dimensional analysis of the interaction of the flame front with flow boundaries is performed. Under some circumstances, this interaction is shown to cause exponential growth of the perturbations.     

Newby shift ofK=0 rotational bands in odd-odd rare-earths

A data set of 29 experimentally determined Newby shifts in rare-earth nuclei is examined for the reliability of each values. Using this data set, Newby shifts are obtained which are free from the Coriolis and the particle-particle coupling effects. These new empirical values help resolve the failure of a recently proposed rule for the sign of the Newby shift in the {5/2[413]p − 5/2[642]n} configuration of¹⁶⁰Tb and the {5/2[402]p − 5/2[512]n} configuration of¹⁷⁴Lu. Also the Newby shifts are significantly modified in two other cases namely the {1/2[411]p − 1/2[521]n} configuration in¹⁶⁸Tm and the {1/2[541]p − 1/2[521]n} configuration in¹⁷²Lu. Only marginal changes are seen in the rest of the cases in the rare-earth nuclei.     

Radiation induced synthesis and swelling characterization of thermo-responsive N-isopropylacrylamide-co-ionic hydrogels

Two-component thermo-responsive hydrogels poly(N-isopropylacrylamide)-co-vinylbenzyltrimethylammonium chloride (NIPA-co-VBT) and poly(N-isopropylacrylamide)-co-p-sodium styrene sulphonate (NIPA-co-SSS) were prepared by using high energy gamma radiation. The gels were characterized by Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and sol-gel analysis. The presence of ionic monomers in NIPA leads to lower gel content. Introduction of ionic components in the matrix enhanced swelling extent but caused slower volume transition. The swelling studies in alcohol indicated that swelling extent was function of polarity of the swelling medium and all gels followed the order water > methanol > ethanol > iso-propanol. In mixed co-solvents (water-alcohol), they exhibit complex reentrant behavior. The co-polymer gels containing VBT swelled faster and to higher extent than those containing SSS. The dynamic swelling studies indicated that diffusion of water in PNIPA gel shifts from Fickian for PNIPA to anomalous for NIPA-co-ionic gels also the mean swelling time (MST) decreases for gels containing ionic monomers.     

Stabilization of platinum(II) hydrides by tri-t-butylarsine; facile syntheses of stable trans-PtH2[As(t-Bu)3]2 and trans-PtHX[As(t-Bu)3]2 complexes

trans-PtH₂[As(t-Bu)₃]₂ was prepared in very good yield by afacile reaction of K₂PtC1₄ with As(t-Bu)₃ in alkaline ethanol. Treatment of trans-PtH₂[As(t-Bu)₃]₂ with CF₃CO₂H or HCI afforded trans-PtH(O₂CCF₃)[As(t-Bu)₃]₂ or trans-PtHCl[As(t-Bu)₃]₂. respectively, in almost quantitative yield.     

Some chemistry of mixed ligand complexes of platinum

Simple synthetic routes to the mixed ligand complexes PtLL'X₂ and PtLL'XY (L' = PEt₃; L = phosphine, arsine, etc.; X = Cl and Y = Cl, H or Me) are described; unexpectedly, these display an extensive chemistry without disproportionation, although in some cases ligand scrambling does occur.     

Structure-activity study of antiepilepticN-aryl-isoxazolecarboxamides/N-isoxazolylbenzamide analogs using Wiener's topological index

The relationship between Wiener's topological index and the antiepileptic activity of a series ofN-aryl-isoxazole carboxamides/N-isoxazolylbenzamide analogs has been investigated. Values of Wiener's topological index for 69 compounds constituting the training set were computed and an active range was identified. Each analog was subsequently assigned an activity which was then compared with the reported antiepileptic activity against the maximal electroshock seizure (MES) test. Due to significant correlation between antiepileptic activity and Wiener's topological index, it was possible to predict antiepileptic activity with an accuracy of 91 % in the active range.     

Electron transfer in the reduction of primary halides by metal hydrides

The reactions of various main-group metal hydrides with 1-halo-5-hexenes and with 1-halo-2,2-dlmethyl-5-hexenes produce both straight chain and cyclized reduction products. The formation of cyclic hydrocarbons clearly indicates the presence of radical intermediates during the course of these reactions.