Nutritional evaluation of soya beans (glycine max): Nitrogen balance and fractionation studies

The poor nutritional performance of rats fed raw soya-bean-containing diets appeared to be due to reduced apparent digestion and absorption of dietary protein, coupled to changes in systemic metabolism leading to a poor overall nitrogen balance. Aqueous heat treatment greatly reduced but did not eliminate the antinutritional effect. Heat treatment with aqueous ethanol was more effective. The whey protein (pH 4.8 soluble extract) fraction contained the bulk of the trypsin inhibitor and haemagglutination activity and gave the poorest net protein utilisation value. However, an eight-fold increase in trypsin inhibitor content did not significantly effect apparent nitrogen digestibility. Therefore inhibition of gut proteolytic enzyme activity in vivo by soya bean trypsin inhibitors did not account fully for the poor nutritional performance. The problems elicited by soya bean are not transitory and thus there was a cumulative deterioration in overall performance for 16 weeks as a result of continuous exposure to soya bean.     

Do spatial skills contribute to sex differences in different types of mathematical problems?

A battery consisting of spatial tests from the Kit of Factor-Referenced Cognitive tests, a linguistic test, and mathematical tests covering a wide exploratory collection of problems was administered to 262 female and 314 male students in Grades 10 and 12 to examine the relationship between sex differences on particular spatial tests and sex differences on particular mathematical problems. In general, the magnitude of the sex difference on any mathematical problem was not diminished when spatial and linguistic scores were taken into account. This finding was observed in the context of sex differences in most of the spatial tests and in the linguistic test. A difference in the direction and size of the sex difference as a function of the type of mathematical problem was also observed. Females performed better than males on logical, relatively abstract problems. Males demonstrated greater mastery of proportionality, scale, and 2- and 3-dimensional problems. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-disclosure of HIV infection: Preliminary results from a sample of Hispanic men.

Examined self-disclosure of HIV infection among 101 adult Hispanic men with HIV infection. Results indicated that disclosure was highly selective and presumably influenced by the social, psychological, and material consequences of informing others about one's medical condition. Ss tended to inform significant others (parents, friends, and lovers) rather than less significant others (employers, landlords, and religious leaders.) There was a high rate of disclosure (75%) to doctors/dentists who were not treating Ss for HIV infection. Gay and bisexual Ss were more inclined to disclose their HIV serostatus to homosexual or bisexual others than to heterosexuals, and to inform those who were aware of their sexual orientation. Disclosure increased with severity of disease independently of length of time since testing seropositive. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microfoams based on castor oil polyurethanes and vegetable fibers

This work was focused on the production and characterization of microcellular polyurethane (PU) composites reinforced with pine wood‐fibers or with hemp, which can be applied to the manufacture of car interior panels, or acoustic insulation panels for the construction industry. The polymers selected for the study were crosslinked PUs, synthesized from a castor oil‐based polyol, with the formulations adjusted to obtain different foaming levels. Microfoamed composites with preferential orientation were prepared from long hemp fibers. Also, samples with random arrangement of short hemp and wood fibers were obtained. The morphology of the composites was analyzed by scanning electron microscopy. The mechanical performance of the reinforced foams was studied through three point bending and dynamic mechanical tests. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Thermal and mechanical characterization of linear low‐density polyethylene/wood flour composites

A linear low‐density polyethylene (LLDPE) matrix was modified with an organic peroxide and by a reaction with maleic anhydride (MAn) and was simultaneously compounded with untreated wood flour in a twin‐screw extruder. The thermal and mechanical properties of the modified LLDPE and the resulting composites were evaluated. The degree of crystallinity was reduced in the modified LLDPE, but it increased with the addition of wood flour for the formation of the composites. Significant improvements in the tensile strength, ductility, and creep resistance were obtained for the MAn‐modified composites. This enhancement in the mechanical behavior could be attributed to an improvement in the compatibility between the filler and the matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2775–2784, 2003     

Particleboards from peanut‐shell flour

Peanuts have been cultivated worldwide for hundreds, if not thousands, of years. However, most peanuts are sold without the shell, and so large quantities of peanut shells remain as byproducts in the field, not being used properly. In this work, the feasibility of making particleboard from milled peanut shells was studied. To obtain medium‐density panels, a low compaction pressure and a high fiber content were used. The physical and mechanical properties of the panels were similar to those reported for wood‐based particleboard when 80 wt % filler was used. The void content of the panels was experimentally determined and used in an attempt to predict the mechanical response of the panels. The stiffness of the particleboard could be greatly improved by a reduction of the porosity, but even a low void content had a critical effect on the strength of the composites. The stiffness of the composites could only be reasonably represented with simple theoretical models when the effect of the porosity was incorporated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 916–923, 2005     

Ni(II)–Mg(II)–Al(III) catalysts for hydrogen production from ethanol steam reforming: Influence of the activation treatments

The effect of the Ni(II)–Mg(II)–Al(III) layered double hydroxide (LDH) activation conditions over the surface and bulk composition and the catalytic performance in ethanol steam reforming (ESR) is studied. Ternary oxides were prepared by thermal decomposition of LDHs synthesized using the homogeneous precipitation method with urea. Catalyst precursor is submitted to two different activation treatments: calcinations at 400, 500, 600 and 700 °C with subsequent reduction at 720 °C, or direct reduction at 720 °C. The samples were characterized by sorptometry, H₂ chemisorption, ICP chemical analysis, thermogravimetric analysis, X-ray diffraction, X-ray photoelectronic spectroscopy and temperature programming reduction. The catalysts obtained by calcination at 600 °C and then reduction at 720 °C and those directly reduced at 720 °C showed the better performance in ESR. The precursor submitted to a proper thermal treatment develops, through a decoration-demixing process, a Ni(II)-poor spinel-type shell onto NiO domains.     

An Approximation to Two-Sided Tolerance Limits for Normal Populations

The authors present a means of computing two-sided tolerance limits for normal populations by algebraic formulae. Their method utilizes the Fisher-Cornish approximation to the chi-square quantile and an equation in three coefficients empirically derived. They include an analysis of the errors in the two formulae and suggest methods of incorporating the calculations in computer programs.

The tables of Weissberg and Beatty [6] have been an invaluable aid for the construction of two-sided tolerance limits for normal populations. In this article we present a means of computing these tolerance limits with a high speed computer following the lead of Weissberg and Beatty. Our method avoids the problem of solving integral equations by replacing the integral equations with algebraic formulae which approximate the solution to a reasonable degree of accuracy.     

Mesoporous silica from rice hull ash

In the synthesis of mesoporous materials, the use of a template with an adequate porosity is normally favoured. As far as silica is concerned, many sophisticated procedures directed towards this goal have been published. It is already well documented that rice hull contains relatively pure silica after combustion of the residual organic matter. The authors of this contribution have recently demonstrated that large surface area silicates react with glycerol around 200 °C to give depolymerized silica with a chemical composition similar to that of poly‐alkoxides. The interest in this so‐called depolymerization is to allow easy formation of reactive gels which retain the memory of the porous structure of the original starting material. Rice hull ash (RHA), obtained after combustion of the organic residues at 500 °C, gives a silica characterized by mesopores with an average diameter about 3.5 nm. It is shown that RHA reacts with glycerol at 200 °C to form gels which, after hydrolysis and calcination, retain the mesoporous character. The hydrolysis procedure and especially, the pH is important for the distribution of the mesoporosity. The very simple reaction of a by‐product of the food industry with glycerol, a “green reagent”, gives a mesoporous solid silica in the form of a reactive gel, with many potential uses. Its use in a new procedure for the synthesis of a supported ZSM‐5 zeolite has been demonstrated. Copyright © 2007 Society of Chemical Industry