Polarographic reduction mechanism and quantum chemical calculations of some α-arylhydrazononitriles

The polarographic reduction of 2-arylhydrazono-3-keto-3-phenylpropionitriles ( I _a–i) and 2-arylhydrazono-3-ketobutyronitriles ( II _a–i) over a wide pH range is reported and discussed. The mechanism of the electrode process is elucidated and confirmed via coulometric analysis, quantum chemical calculations and IR spectra of the electrolysis products. The molecular structures and molecular orbital energies were calculated and correlated with the redox potentials of these compounds.     

Microstructure and mechanical properties of Al-Al2O3-MgO cast particulate composites

Al-Al₂O₃-MgO cast particle composites prepared by an MgO coating technique were investigated for their microstructural and mechanical property features. In all, sixteen compositions of the composite were subjected to this study. Generally, a uniform distribution of Al₂O₃ particles was observed in the composites. But in the upper half portion of the cylindrical castings, Al₂O₃ particles were found to segregate along the grain boundaries and also within the grain-forming chain-like structures. The microhardness of the base matrix revealed that the retention of submicrometre MgO particles causes dispersion strengthening. In the case of maximum strengthening, the microhardness of the base matrix rises to 35 kg mm^–2 from 19 kg mm^–2 for as-cast pure aluminium. The composites also displayed excellent high-temperature tensile properties up to 250°C (523 K). At the level of 21%V _f retention of Al₂O₃, the composite displayed a UTS value of 110 MN m^–2 with corresponding 0.2% offset yield strength of 65 MN m^–2 and 12% elongation at ambient temperature. At 150° C (423 K) and 250° C (523 K), the composite retains 69% and 53%, respectively, of its room-temperature UTS value. This was the optimum retention of Al₂O₃ and the best composite obtained in the present work. The excellent high-temperature characteristics of the composite are thought to be due to the sum total effect of both the submicrometre MgO particles and the coarser Al₂O₃ particles retained in the aluminium base matrix.     

Use of Position and Feature Cues in Discrimination Learning by the Whiptail Lizard (Cnemidophorus inornatus).

Animals use a variety of cue types to locate and discriminate objects. The ease with which particular cue types are learned varies across species and context. An enormous literature contains comparisons of spatial cue use to use of other cue types, but few experiments examine the ease with which various nonspatial cues are learned. In addition, few studies have examined cue use in reptiles. Thus, the authors compared whiptail lizards' (Cnemidophorus inornatus) ability to learn and reverse a discrimination using either position (left or right) or visual feature cues. Lizards learned and reversed the task using position cues faster and with greater accuracy than using feature cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Wired-AND Current-Mode Logic Circuit Technique in CMOS for Low-Voltage, High-Speed and Mixed-Signal VLSIC

A wired-AND current-mode logic (WCML) circuit techniquein CMOS technology for low-voltage and high-speed VLSI circuitsis proposed, and a WCML cell library is developed using standard0.8 micron CMOS process. The proposed WCML technique appliesthe analog circuit design methodologies to the digital circuitdesign. The input and output logic signals are represented bycurrent quantities. The supply current of the logic circuitis adjustable for the required logic speed and the switchingnoise level. The noise is reduced on the power supply lines andin the substrate by the current-steering technique and by thesmooth swing of the reduced node potentials. Precise analogcircuits and fast digital circuits can be integrated on the samesilicon substrate by using the low noise property of the WCML.It is shown by the simulations that at low supply voltages, theWCML is faster and generates less switching noise when comparedto the static-CMOS logic. At high speeds, the power dissipationof the WCML is less than that of the static-CMOS logic.     

Quality management in the manufacturing industry: Practice vs performance

This study examines the quality management practices in the manufacturing industry in Ireland on the performance of companies. The key findings point to the existence of a moderately positive linear relationship with a correlation coeffiecient of 0.694 between practice and performance. All the available multiple comparison tests conducted showed there is a significant difference in competitive ability between firms with 20–50 employees and theother employment group. From the perspective of competitive advantage, firms are better off being big rather than small. Also the local indigenous firms are at a competitive disadvantage unless jointly owned by foreign partners. Foreign owned firms have better quality management practices with a mean total score of 25% higher than local firms. Furthermore, it appears that being a subsidiary or part of a larger organisation and membership to a quality association contributes to better performance. Competitive sectors like Plastics and Rubber, Chemical and Electrical/Electronics have higher mean total scores than the rest and are above industry average. Firms that have larger export markets have better quality management practices. Finally companies accredited with ISO 9000 (66% of respondents) and or had implemented TQM (19% of respondents) exhibit a wide range of performance and statistically are significantly different than those without.     

Energy transport to molten flowing polymer systems: II. Analysis of data and development of temperature profiles with axial length

Energy transport to molten, flowing polymer has been studied. Experimental temperature profiles were determined at various axial lengths. These data are both precise and reproducible. Viscous dissipation was found to be a significant factor in these systems. In addition, sizable thermal expansion cooling effects were noted. It was also shown that the effect of viscous dissipation on Nusselt number was a function of Graetz number. At high Graetz numbers viscous dissipation had a sizable effect that declined to negligible proportions at Graetz values of 7 or less. Prior theoretical treatment of temperature profile development is shown to be only qualitatively correct.     

Soft clustering of multidimensional data: a semi-fuzzy approach

This paper discusses new approaches to unsupervised fuzzy classification of multidimensional data. In the developed clustering models, patterns are considered to belong to some but not necessarily all clusters. Accordingly, such algorithms are called ‘semi-fuzzy’ or ‘soft’ clustering techniques. Several models to achieve this goal are investigated and corresponding implementation algorithms are developed. Experimental results are reported.     

K-means-type algorithms: a generalized convergence theorem and characterization of local optimality

The K-means algorithm is a commonly used technique in cluster analysis. In this paper, several questions about the algorithm are addressed. The clustering problem is first cast as a nonconvex mathematical program. Then, a rigorous proof of the finite convergence of the K-means-type algorithm is given for any metric. It is shown that under certain conditions the algorithm may fail to converge to a local minimum, and that it converges under differentiability conditions to a Kuhn-Tucker point. Finally, a method for obtaining a local-minimum solution is given.     

Maximizing embedding capacity for speech steganography: a segment-growing approach

It has been proven that the higher the correlation level between samples in the time-domain of a digital signal, the stronger the energy com paction property in the Discrete Cosine Transform (DCT) domain. This paper aims to investigate the limits of the DCT energy compaction property in speech signals by segmenting the cover speech signal into correlated segments and hide in each segment. The Hiding process is performed using a hiding strategy in spired by the Amplitude Modulation (AM) technique. Due to segmentation, the homogeneity is expected to increase which causes the energy of the signal to be strongly compacted in a few critical DCT coefficients, and therefore, a substantial amount of insignificant DCT coefficients can be replaced with the secret data without sacrificing the quality of the signal. Experimental results have proven the effectiveness of the proposed scheme which outperforms other speech steganography techniques recently published in the literature.

     

2-D canonical correlation analysis based image super-resolution scheme for facial emotion recognition

Multimedia Tools and Applications - In this research work, a new Image super-resolution-based Face Emotion Recognition Model has been introduced. The proposed work includes two major phases: (a)...