Identification of stress-induced leakage current components and thecorresponding trap models in SiO2 films [MOStransistors]

Time-decay stress-induced leakage current (SILC) has been systematically investigated for the cases of both Fowler-Nordheim (FN) stress and substrate hot-hole stress. From the three viewpoints of the reproducibility of the current component for the gate voltage scan, the change of oxide charge during the gate voltage scan, and the resistance of the current component to thermal annealing, it has been found that time-decay stress-induced leakage current is composed of five current components, regardless of stress type. Trap models corresponding to each current component have been proposed. In addition, it has also been proven that holes generate the electron traps related to one of those current components     

Effect of surfactants on phenol removal by the method of polymerization and precipitation catalysed by Coprinus cinereus peroxidase

The removal of phenol by peroxidase‐catalysed polymerization was examined using Coprinus cinereus peroxidase in the presence of surfactants. The non‐ionic surfactants with poly(oxyethene) residues, Triton X‐100, Triton X‐405 and Tween 20, enhanced the phenol removal efficiency at a level similar to high relative molecular mass poly(ethylene glycol) (relative molecular mass 3000). Although the improvement in the removal efficiency was less than that of Triton X‐100, Span 20, sodium lauryl sulfate (SDS) and lauryl trimethylammonium bromide (DTAB) also enhanced the removal efficiency. The requirement of the enzyme for almost 100% removal of 100 mg dm^?3 phenol decreased to one‐fourth by the addition of 30 mg dm^?3 Triton X‐100. Triton X‐100, Triton X‐405, Tween 20 and DTAB could reactivate the enzyme precipitated with the phenol polymer, leading to the restarting of the phenol removal reaction. Copyright © 2003 Society of Chemical Industry     

Preparation and properties of transparent cellulose hydrogels

Highly transparent cellulose hydrogels with physical crosslinkage were prepared from nonaqueous organic cellulose solutions and viscose by coagulating and regenerating cellulose in an aqueous solution containing a water‐miscible organic solvent. Nonaqueous organic cellulose solutions used were LiCl/dimethylacetamide, paraformaldehyde/dimethyl sulfoxide, and triethylammonium chloride/dimethyl sulfoxide. Preparation conditions and physical properties of the transparent cellulose hydrogels were studied. The transparency of the cellulose hydrogels depended on the composition of the aqueous solution containing the organic solvent. Furthermore, transparent cellulose hydrogels from viscose showed high tensile strength. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3020–3025, 2003     

A Method for Automatic Detection of Vocal Fry

Vocal fry (also called creak, creaky voice, and pulse register phonation) is a voice quality that carries important linguistic or paralinguistic information, depending on the language. We propose a set of acoustic measures and a method for automatically detecting vocal fry segments in speech utterances. A glottal pulse-synchronized method is proposed to deal with the very low fundamental frequency properties of vocal fry segments, which cause problems in the classic short-term analysis methods. The proposed acoustic measures characterize power, aperiodicity, and similarity properties of vocal fry signals. The basic idea of the proposed method is to scan for local power peaks in a ldquovery short-termrdquo power contour for obtaining glottal pulse candidates, check for periodicity properties, and evaluate a similarity measure between neighboring glottal pulse candidates for deciding the possibility of being vocal fry pulses. In the periodicity analysis, autocorrelation peak properties are taken into account for avoiding misdetection of periodicity in vocal fry segments. Evaluation of the proposed acoustic measures in the automatic detection resulted in 74% correct detection, with an insertion error rate of 13%.     

Structural stability and mechanochemical activity of titanium nitride prepared by mechanical alloying

Pure titanium nitride (TiN) was synthesized by mechanical alloying (MA). In order to prevent the contamination from the MA vial and atmospheric gas, the MA steel vial was replaced with a titanium vial and atmospheric gas was deoxidized using sponge titanium heated to 623 K. The mechanochemical activity during MA was estimated from the gas purification temperature. The investigation of thermal and pressure stability by thermal treatment and hot isostatic pressing (HIP) revealed that titanium nitride, TiN, was stable on heating to 1173 K under a vacuum, but became unstable under a high pressure, 100 MPa.     

Development of a high-efficiency H2 feeder for bioremediation.

An electrochemical dissolved hydrogen feeder equipped with a multi-cathode system and a high-rate recirculation pump was developed in order to examine its feasibility for bioremediation. Results showed that the feeding efficiency was remarkably higher than that in former studies. The reason for the enhanced hydrogen dissolution rate was thought to be due to the large cathode area by applying multiple granular activated carbon electrodes resulting in low current density. Two mass balance equations were formulated and applied to analyze the performance of the apparatus theoretically. The hydrogen dissolution rate calculated from the equations was in fairly good agreement with observed results. It was suggested that the electrochemical H2 feeder would be a competitive alternative as a hydrogen feeding method for bioremediation.