A heuristic method for optimum redundancy allocation in non-coherent systems

This paper presents a heuristic method for optimum redundancy allocation in non-coherent systems. The method uses two forms of redundancy, namely parallel and series forms. System reliability of non-coherent systems cannot be generally improved by using only parallel redundancy. So use of series or parallel redundancy, whichever gives better system reliability, is recommended. The proposed method retains all the advantages of the most recommended [2,4,5] heuristic reliability optimization techniques. The method is general and can be used with linear or non-linear, separable or non-separable constraints.     

Investigation of Subthreshold Characteristics of Negative Capacitance Single-Active Layer Double-Gate (NC-SALDG) Thin-Film Transistor (TFT)

Silicon - In this paper, for the first time, the performance evaluation of negative capacitance single-active layer double-gate (NC-SALDG) TFT is presented. In the proposed NC-SALDG TFT, amorphous...     

Synthesis,characterization of β-CD based novel hydrogels with dual objectives of drug release and dye removal

Iranian Polymer Journal - In our recent work, we have reported on hydrogels devoid of cross-linkers. After observing the successful swelling and water retention properties, we have introduced...     

Hydrogen permeation during zinc-manganese alloy plating

Electrodeposition of metals from solution is usually accompanied by the simultaneous discharge of hydrogen ions or water molecules. When hydrogen is liberated at an iron/steel surface during electrodeposition, a portion of the hydrogen is absorbed by the metal surface and then diffuses into the interior. The diffused hydrogen produces some detrimental effects, such as reduction in ductility and loss in mechanical strength, leading to hydrogen embrittlement. The present paper reports investigations on hydrogen permeation measurements in zinc-manganese alloy deposition using a modified electrode clamp for easy removal and fixing of the electrode. Hydrogen permeation studies indicate that the porosity of the deposit increases in the following order:Zn-Mn(14.3%), Zn-Mn(2.4%), Zn-Mn(24.8%) and Zn-Mn(37.5%).This is in agreement with the corrosion data obtained which indicates that Zn-Mn alloy deposits with low manganese content show better performance than pure zinc deposits.     

Aminotetryls: Synthesis,spectral characterization,thermal decomposition and explosive properties

This paper describes the synthesis and spectral investigations of two amino derivatives of N-methyl-N-(2,4,6-trinitrophenyl)nitramine (tetryl). Also discussed are the results from thermal decomposition studies on the three explosives, viz. tetryl, 3-aminotetryl (3 AT) and 3,5-diaminotetryl (3,5 DAT) and preliminary work on the explosive properties of the last two compounds. The aminotetryls have been prepared by the amination of the corresponding chlorotetryls. The yield was 87% for 3 AT, but was only 33% for 3,5 DAT, probably due to steric crowding around the benzene nucleus. The mass spectra show interesting differences in the electron impact fragmentation patterns of the three tetryls with the M⁺ ion relative intensities following the order 3,5 DAT > 3 AT > tetryl, which could be due to (a) resonance stabilization and (b) hydrogen bonding effects. Evidence for the latter is also found in the infrared spectra of these compounds. Arrhenius kinetic parameters derived from thermal decomposition studies of the three compounds are presented and show that 3,5 DAT is thermally less stable than 3 AT. Explosive sensitiveness tests indicate that the diamino compound is the most sensitive, the trend being 3,5 DAT > 3 AT > tetryl. This is contrary to the generally found desensitizing influence of NH₂ groups on the thermal stability and explosive sensitiveness of trinitroaromatic energetic molecules. Mechanisms to account for the observed thermal decomposition behaviour and explosive sensitiveness patterns are discussed.     

Palladium dispersed multiwalled carbon nanotube based hydrogen sensor for fuel cell applications

Palladium nanocatalysts supported on surface-oxidized multiwalled carbon nanotubes (MWNT) were prepared by the aqueous solution reduction of _PdCl2${\mathrm{PdCl}}_2$. MWNT have been synthesized by catalytic chemical vapor deposition (CCVD) technique. Pyrolysis of acetylene using a fixed-bed catalytic reactor over rare earth (RE) based _AB2${\mathrm{AB}}_2$ alloy hydride catalyst, obtained through hydrogen decrepitation technique, has been performed to synthesize MWNT. Structural, morphological and vibrational characterizations have been carried out using XRD, SEM, TEM and Raman spectroscopy, respectively. In situ electrical resistance measurements for thin films of MWNT obtained by spin coating samples were carried out by two-probe technique in a chamber with provision to introduce known concentration of hydrogen in constant air flow. Investigations of hydrogen sensing properties of Pd–MWNT ensembles have been carried out. The stability of Pd–MWNT thin films after several cycles of adsorption and desorption was studied. The change in electrical resistance due to hydrogen adsorption is reversible, with increase to saturation on exposure to hydrogen gas. The results demonstrate that chemically treated MWNT functionalized with nanostructured Pd show good _H2${\mathrm{H}}_2$ sensing response at room temperature.     

Maximization of representativity factors for experimental planning of cross-section measurements: An information theoretic approach

The similarity between two nuclear systems is expressed by the representativity factors and maximizing its value to unity reduces the uncertainty from its existing value. As the representativity factor is a function of covariance matrix of neutron cross-sections, the inherent systematic uncertainty in neutron cross-sections inhibits it from approaching unity and hence statistical procedures have to be resorted to minimize the systematic uncertainty. As the conventional statistical techniques fail when systematic uncertainty is dominant, we propose an entropy based information theoretic approach of maximizing the mutual information by the knowledge of bounds for the correlated elements. We show that maximizing the mutual information and the representativity factors express the similar phenomena of uncertainty reduction. We estimated the bounds for the correlated elements of the correlation matrix for minor actinides and show how the systematic uncertainty is reduced when lower bound values are considered. These lower bound values aid in experimental planning for future measurement of cross-sections with reduced systematic uncertainty.     

Less common causes of carpal tunnel syndrome

A new DRB3*02 allele (DRB3*0207) was detected in a female Luxembourg Caucasian blood donor by sequence-based typing. The new allele differs from DRB3*0202 by two substitutions in codon 57 resulting in an amino acid change from a charged aspartic acid to a neutral valine. This is the first example of a DRB3 allele pair differing only at codon 57.     

Preparation of ceria-zeolite catalysts by different techniques and its effect on selective catalytic reduction of NO with NH3 at high space velocities

Topics in Catalysis - Several zeolite-based catalysts containing Ce3+ and/or CeO2 were prepared by a variety of catalyst preparation techniques like ion exchange, solid-state ion exchange,...