Static and dynamic removal rates of a new hydrodynamic polishing tool

A new tool for hydrodynamic radial polishing, HyDra, allows for the local polishing of optical surfaces with a controllable wear rate. The results of the removal rate for different polisher types and sizes, applied air pressures for slurry expulsion, and tool height with respect to the working surface, are reported. We present a numerical analysis of the volumetric removal rate for the dynamic experiments as well as a comparison with a similar technique.     

Women and minorities in psychology.

Presents results from the American Psychological Association's 1978 Human Resources Survey, the 1980–1981 Survey of Graduate Departments of Psychology, and the 1972–1980 surveys of doctorate recipients from the National Research Council. In addition to overall level of representation of women and minorities, a number of other important variables are examined (e.g., subfield specialty, degree level, years of experience since earning highest degree). Recent trends in the representation of women and minorities among doctorate recipients and doctoral students are discussed. It is concluded that despite progress toward achieving equality, many problems remain, including the severe underepresentation of minorities and pervasive subfield segregation and pay inequities for women. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation de la tourbe de sphaigne par le dioxyde de carbone et agglomération du charbon actif produit

The physical activation of peat moss using CO₂ has been investigated with respect to the operational variables and the characteristics of the active carbon produced. Peat coke is produced during carbonisation with a 30% yield. The activated carbon accounts for 25% of the initial air dried peat moss. Analysis of the active carbon has revealed a surface area up to 600 m²/g and a chemical reactivity similar to commercial active carbon as measured by the iodine, phenazone and phenol indexes. The active carbon thus produced is a powdered material, with a weak abrasive resistance. Agglomeration of the carbon and subsequent pelletization has been done with ammonium ligno-sulfonate, water, and the application of pressure. Resistant pellets can be obtained using 15–20% lignosulfonate and 3000 psi.     

Effect of sterilisation on dietary fibre and physicochemical properties of onion by-products

Food industries are forced to develop productions without secondary residues. Therefore, there is a considerable emphasis on the recovery, recycling and upgrading of wastes. The possibility has been suggested for the conversion of onion waste into food ingredients, but with a stabilisation treatment being necessary. The objective of this work was to study the effect of sterilisation on fibre fractions, fibre composition and physicochemical properties of onion by-products to evaluate the use of sterilised onion by-products as a source of fibre.     

Detection and identification of wild yeasts in Champús, a fermented Colombian maize beverage

The aim of this study was to identify and characterise the predominant yeasts in Champús, a traditional Colombian cereal-based beverage with a low alcoholic content.Samples of Champús from 20 production sites in the Cauca Valley region were analysed. A total of 235 yeast isolates were identified by conventional microbiological analyses and by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of ITS1-5.8S rDNA-ITS2. The dominant species were: Saccharomyces cerevisiae, Issatchenkia orientalis, Pichia fermentans, Pichia kluyveri var. kluyveri, Zygosaccharomyces fermentati, Torulospora delbruekii, Galactomyces geotrichum and Hanseniaspora spp. Model Champús systems were inoculated with single strains of some isolated sporogenus species and the aromatic profiles were analysed by SPME. Analysis of data showed that Champús strains produced high amounts of esters. The aromatic compounds produced by Saccharomyces and non-Saccharomyces yeasts from Champús can exert a relevant influence on the sensory characteristics of the fermented beverage. The Champús strains could thus represent an important source for new yeast biotypes with potential industrial applications.     

Complexation of heavy metals by phytochelatins: voltammetric study of the binding of Cd2+ and Zn2+ ions by the phytochelatin (gamma-Glu-Cys)3Gly assisted by multivariate curve resolution

The complexation of Cd2+, Zn2+, and both together with the phytochelatin (gamma-Glu-Cys)3Gly is studied by differential pulse polarography, and data are analyzed by multivariate curve resolution by alternating least squares (MCR-ALS). MCR-ALS yields the respective unitary voltammograms and concentration profiles of the resolved components, which contain information on the relative stabilities and stoichiometries of the formed complexes. The analysis of these results shows, for the Cd2+/(gamma-Glu-Cys)3Gly system, the presence of different kinds of bound Cd2+. For the Zn2+/ (gamma-Glu-Cys)3Gly system, the poor definition of the reduction signals of the complexes prevents a clear discrimination among differently bound Zn2+ ions. Atentative complexation/ electrochemical model is proposed for when both metal ions, Cd2+ and Zn2+, compete toward complexation, and some of the corresponding equilibrium constants are estimated.     

Efficient modal analysis of arbitrarily shaped H-plane two-port waveguide devices using the 2D parallel-plate Green?s function

A very efficient method for the accurate analysis of arbitrarily shaped H-plane two-port structures in rectangular waveguide technology is presented. The method is based on the integral-equation technique, which makes use of the Green?s function of an infinite line source placed inside two parallel plates. All the terms of the series of the Green?s function are analytically integrated, thus resulting in new series with accelerated convergence. After performing an exhaustive convergence analysis, optimal values for the parameters of this new method have been found and used in all calculations. The new method has been successfully tested after analysing several practical H-plane structures, such as inductive filters including the mechanisation effect of rounded corners.