Harmonic differential quadrature method and applications to analysis of structural components

Summary A harmonic differential quadrature (HDQ) method with application to the analysis of buckling and free vibration of beams and rectangular plates is presented. A new approach is proposed for the determination of the weighting coefficients for differential quadrature. It is found that the HDQ method is more efficient than the ordinary differential quadrature (DQ) method, especially for higher order frequencies and for buckling loads of rectangular plates under a wide range of aspect ratios. Also, some shortcomings existing in theDQ method are removed.     

A Field-Limited Theory of Cascade Development

Recently reported model experiments of Knapp [1] on electroded cascade development provide an excellent set. of data for testing presumptive development models since so many of the experimental parameters are available. A development model is presented that is based on the assumption that in the dynamic process of cascade development the instantaneous force binding a toner to a carrier is proportional to q, the charge on the toner, rather than to q2. This is in contrast to the q2 force dependence observed in equilibrated mixtures. The mechanism of toner detachment is impact-assisted electric-field stripping. Statistical distributions for toner radius, surface charge density, and impact velocity are introduced. The results are compared with Knapp's experiments and with a recent theoretical model of Maitra, Scher, and Knapp (MSK). In contrast to MSK, although the specific form of the distributions is important for the conclusions, the particular parameters of the distributions have little effect. The statistics do not smear the physics.     

A novelstreptomyces species for controlling plant-parasitic nematodes

A novel species ofSteptromyces isolated from nematode suppressive soils in Costa Rica was evaluated for efficacy in controlling plant-parasitic nematodes. This isolate, designated CR-43, was shown to inhibit reproduction ofCaenorhabditis elegans in a laboratory assay. Greenhouse trials utilizing three different methods of treatment with CR-43 gave significant reductions of tomato root galling due toMeloidogyne incognita. In a field experiment in Puerto Rico, in soil naturally infested withM. incognita, CR-43-treated pepper showed significant reductions in root galling and significant increases in yield as compared to untreated controls. In a second experiment in Puerto Rico, a significant reduction in tomato root galling and a slight reduction in root galling on pepper occurred. In this trial, yields on both tomato and pepper were higher in CR-43 treatments, but these differences were not statistically significant. In both experiments populations ofRotylenchulus reniformis were reduced by CR-43 treatment. In a field trial on strawberry in Massachusetts, CR-43-treated plants had lower numbers ofPratylenchus penetrons within roots and showed a significant decrease in black root rot disease. Studies on sterile filtrates from CR-43 cultures indicated that a major determinant of CR-43 antinematodal activity was mostly thermostable macromolecules of molecular weight higher than 6000. Culture filtrates of CR-43 exhibited antifungal activity in vitro.     

Air purification by catalytic oxidation in a reactor with periodic flow reversal

The behaviour of an adiabatic packed bed reactor with periodic flow reversal has been studied by means of model calculations. A heterogeneous model as well as a pseudo-homogeneous model have been developed. It is shown that a high degree of conversion can be obtained in an autothermal process even with very low adiabatic temperature rises of some 10 to 20 K. The reactor is insensitive to fluctuations in inlet concentrations and in through-put. Short-cut methods proposed in the literature for calculating the plateau temperature in the pseudo-steady state are studied. The so called countercurrent-flow reactor approach showed reasonable agreement with the plateau temperature obtained by dynamic calculations with the full reactor model.     

Lateral association of vertically coupled quantum dots

The modification produced in the structural and optical properties of vertically coupled In_0.5Ga_0.5As quantum dots in a GaAs matrix by increasing the number of deposited layers of quantum dots has been investigated. It was shown that the deposition of a sequence of In_0.5Ga_0.5As quantum-dot planes separated by narrow (of the order of the height of the quantum dots) GaAs layers gives rise to an interaction between neighboring vertically coupled quantum dots. This interaction shifts the photoluminescence line due to the recombination of nonequilibrium carriers via states of the quantum dots into the region of lower photon energies. Fiz. Tekh. Poluprovodn. 31, 851–854 (July 1997)     

Arrays of strained InAs quantum dots in an (In Ga)As matrix, grown on InP substrates by molecular-beam epitaxy

Arrays of strained InAs islands in an (In, Ga)As matrix on an InP(100) substrate are synthesized by molecular-beam epitaxy, and their structural and optical properties are investigated. According to transmission electron microscope and high-energy electron diffraction data, the critical thickness corresponding to the onset of island growth is 3 monolayers. The resulting InAs islands are coherently strained, and their base diameter varies from 20 nm to 90 nm. The formation of islands produces in the photoluminescence spectra a dominant long-wavelength line, which shifts toward lower energies as the effective thickness of the InAs increases. The radiation emitted by the InAs islands spans a wavelength range of 1.65–2 μm. Fiz. Tekh. Poluprovodn. 31, 1256–1260 (October 1997)     

Novel zinc‐rich epoxy paint coatings with hydrated alumina and carbon nanotubes supported polypyrrole for corrosion protection of low carbon steel: Part I: Inhibitor particles and their dispersions

In part 1 of this work, preparation, structure, spectroscopic, and electrochemical characteristics of the polypyrrole (PPy) deposited alumina/multi‐walled carbon nanotubes (MWCNTs) inhibitor particles (PDAMIPs) are presented. TEM observations evidenced uniform deposition of thin PPy film on the functionalized nanotubes, whereas co‐deposition of PPy and polystyrene sulfonic acid (PSS) lead to thick polymer coverage on hydrated alumina. Modification with polymer complexes resulted in moderately dispersed PDAMIPs, which is due to the various degrees of aggregation and coalescence. FTIR revealed compact and dense PPy structure on the functionalized MWCNTs while it was not the case on alumina and the PSS modified nanotubes. Closer interaction of PPy with the MWCNTs resulted in enhanced charge mobility, whereas greater electroactivity and reversibility of PPy were noted to samples containing functionalized nanotubes and low amount of PSS. Rheological study verified moderate micron‐scale dispersity and the modification caused various degrees of aggregations of the PDAMIPs. These were recognized to be valid in the suspensions at a solid phase concentration with component contents similar to the corrosion tested hybrid coatings. Rheological percolation of the nanotubes (with anisotropic factor of ～100) was confirmed at volume fractions of 3.30 × 10^?3 and 6.0 × 10^?4 which were under the dilute/semi‐dilute boundary type theoretical and experimental thresholds. This is related to the extensive interconnection of the nanotube‐supported filaments. Thus, overlapping of the nanotubes should contribute to the electrical percolation thereby galvanic corrosion prevention function of the zinc‐rich hybrid coatings, which is discussed in the 2nd part.     

Relationship between facial expressiveness and sympathetic activation in emotion: A critical review, with emphasis on modeling underlying mechanisms and individual differences.

Two important questions bearing on personality processes and individual differences are how do facial expressiveness and sympathetic activation vary as a function of the intensity of an emotional stimulus, and what is the functional mechanism underlying facial expressiveness and sympathetic activation in emotion? A formulation is proposed that is based on 2 propositions: (1) All strong emotions result in some degree of activation of the organism (i.e., principle of stimulus dynamism) and (2) there are individual differences in the gain (amplification) operating on the facial expressive and sympathetic response channels (i.e., principle of individual response uniqueness). This formulation organizes much of the existing data on internalizers and externalizers and yields novel predictions regarding the subpopulation labeled as generalizers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)