Environmental impact of castor oil catalytic transfer hydrogenation

In the vegetable oil chemical industry, hydrogenation is one of the most important processes. An alternative method for vegetable oil hydrogenation is the use of catalytic transfer hydrogenation (CTH), which can utilize organic molecules as hydrogen donors at ambient pressure. These alternative processes should be optimized in relation to the variables required for a good conversion and impacts should also be known to be minimized. An assessment of the environmental impact of laboratory scale chemical processes is an important tool to improve the technological aspects of a process (increased yields, reduced production times, lower costs) and it can also lead to the creation of a cleaner technology. Using the Leopold Matrix, we have succeeded in developing a more efficient and cleaner process for the CTH of castor oil using Raney Ni as a catalyst and cyclohexene or isopropanol as a hydrogen donor solvent. The results of the technical and environmental assessments showed that the extent of conversion for the unsaturation reaction was high (>99 %), and the environmental impact of the process could be significantly reduced to create a cleaner technology. It was found, after process optimization, that the remaining environmental impacts were negative (67.48 %), local (78.95 %), temporary (95.33 %), direct (80.12 %), and reversible (95.32 %).     

A Matrix Formulation of Discrete Chirp Fourier Transform Algorithms

This work presents a computational matrix framework in terms of tensor signal algebra for the formulation of discrete chirp Fourier transform algorithms.These algorithms are used in this work to estimate the point target functions(impulse response functions)of multiple-input multiple-output(MIMO)synthetic aperture radar(SAR)systems.This estimation technique is being studied as an alternative to the estimation of point target functions using the discrete cross-ambiguity function for certain types of environmental surveillance applications.The tensor signal algebra is presented as a mathematics environment composed of signal spaces,finite dimensional linear operators,and special matrices where algebraic methods are used to generate these signal transforms as computational estimators.Also,the tensor signal algebra contributes to analysis,design,and implementation of parallel algorithms.An instantiation of the framework was performed by using the MATLAB Parallel Computing Toolbox,where all the algorithms presented in this paper were implemented.     

Adsorption and surface chemistry in tribology

Adsorption on sliding surfaces and the chemical changes occurring within a few nanometers of the surface are key to the performance of lubricants and lubricant additives in the boundary lubrication regime. By means of the methods of modern surface science, these phenomena are beginning to be elucidated on a molecular level. This knowledge will be essential, both for the development of higher-performance lubricants, capable of high-temperature operation, as well as for the design of environmentally benign alternatives to the lubricant systems in current use.     

Effect ofSolanum Glycoalkaloids on Potato Aphid,Macrosiphum euphorbiae

Macrosiphum euphorbiae, also known as the potato aphid, is a potato virus vector, associated with decreased tuber production. Feeding, toxicity, and reproductive effects of the major potato glycoalkaloids (α-chaconine and α-solanine), their common aglycone (solanidine), and a nonpotato glycoalkaloid (α-tomatine) and its aglycone (tomatidine) onM. euphorbiae were studied. As expected, neither α-chaconine nor α-solanine had a strong lethal effect on the aphid, but α-chaconine stimulated feeding at low concentrations. Both aglycones were deterrent and lethal at high concentrations and, like α-chaconine and α-tomatine, they delayed the appearance and decreased the number of nymphs.     

A toolkit for constructing command driven graphics programs

This paper describes a toolkit designed to construct graphics applications on top of it that are command driven. The aim in its design is to achieve a uniform look-and-feel for the applications developed in the department, and to make it possible to construct demonstration programs or test programs of ongoing research that required a sophisticated user interface with minimal fuss. The present implementation runs under UNIX, but the same philosophy could be used in other environments.     

Catalytic Reduction of 4-Nitrobenzoic Acid by cis-[Rh(CO)2(Amine)2](PF6) Complexes Under Water–Gas Shift Reaction Conditions: Kinetics Study

Rhodium(I) complexes of the type, cis-[Rh(CO)₂(amine)₂](PF₆) where (amine = 3-picoline, 2-picoline, pyridine, 2,6-lutidina or 3,5-lutidine) dissolved in 80% aqueous amine solutions catalyzed the selective reduction of 4-nitrobenzoic acid to 4-aminobenzoic acid under CO atmosphere. The importance of these catalytic systems is their high chemo selectivity for the aromatic nitro group of the 4-nitrobenzoic acid with respect to the carboxylic group, allowing the production of the desired aromatic amine in high yields. The 4-aminobenzoic acid production depends on the nature of the coordinated amine. The Rh/3,5-lutidine system, the most active catalyst among tested, displays turnover frequencies for 4-aminobenzoic acid production of about 173 moles per mole Rh per day for [Rh] = 1 × 10^?4 mol, [4-nitrobenzoic acid] = 3.82 × 10^?3mol, 10 mL of 80% aqueous 3,5-lutidine, P(CO) = 0.9 atm at 100 °C. Analyses of kinetic results for the Rh/3,5-lutidine system show a first order dependence on 4-nitrobenzoic acid concentration, a non-linear dependence on CO pressure, a segmented Arrhenius plot and dependence on the nature of the reducing gas agent. These data are discussed in terms of a possible mechanism.     

A comparative effect of the experimental diet on growth and development of rats

There are presented the results of a comparative assessment of the semi-synthetic casein diet, traditionally used by Institute of Nutrition RAMS, and the AIN-93 purified diet, offered by the American Institute of Nutrition, on growth and development of rats. A total of 60 male Wistar rats were used at 90-days experiment, rats were divided into two groups: first group received the semi-synthetic casein diet, the second group--AIN-93 diet. Analysis of integral, hematological and biochemical parameters revealed some differences between groups, but values of all studied parameters were within the physiological norm for Wistar rat. Based on the results of this experiment were suggested a new formulation of a diet for laboratory animals.     

Fermentation characteristics and aerobic stability of wet corn distillers grains with solubles ensiled in combination with whole plant corn

BACKGROUND: Wet corn distillers grains with solubles (WDG) are prone to aerobic spoilage when stored for an extended period of time. The objective of this study was to evaluate the fermentation characteristics of ensiling WDG with whole plant corn (WPC) using the following combinations: (1) 100% WPC; (2) 75% WPC + 25% WDG; (3) 50% WPC + 50% WDG; and (4) 100% WDG. RESULTS: The initial pH was greatest for 100% WPC and lowest for 100% WDG (5.7, 4.6, 4.0, and 3.1, respectively). Concentrations of ammonia nitrogen (12.0, 26.8, 40.7, and 50.8 g kg^?1 dry matter (DM)) and Crude protein (CP) (98.7, 155.8, 206.8, and 307.9 g kg^?1 of DM) increased with increasing concentrations of WDG. Lactic acid concentration prior to ensiling was greatest for 100% WDG (9.0 g kg^?1 DM) and decreased with WPC in the silage. Acetic, propionic, and butyric acids were not present prior to ensiling. The pH of the ensiled feeds dropped below 4.0 by day 3, with no further decrease over time. Acetic acid increased from undetected amounts at day 0 to 38.8, 43.9, 43.2, and 2.2 g kg^?1 of DM at day 129 as concentration of WDG increased. Aerobic stability was enhanced with increasing WDG concentration in the silage. CONCLUSION: Fermentation, nutrient profile, and aerobic stability can be improved when ensiling wet distillers grains with whole plant corn. Copyright © 2011 Society of Chemical Industry     

Electrical properties of the DGEBA/PANI-Ag composites

The metallopolymer polyaniline-silver (PANI-Ag) was synthesized and used as conductive filler in crosslinked diglycidyl ether of bisphenol A (DGEBA) epoxy network. The hybrid organic/inorganic PANI-Ag powders were successfully synthesized via in situ chemical oxidation of polyaniline-emeraldine base (PANI-EB) by the capped Ag⁺ on the polyaniline-emeraldine base (PANI-EB) surface. The UV–Vis and FT-IR spectra confirmed the pernigraniline structure (PN) of PANI in the hybrid PANI-Ag. The PANI-Ag dispersion in epoxidic matrix was analyzed by optical microscopy (OM). The images analysis from OM showed that the particle agglomerate size of the metallopolymer increased with increasing PANI-Ag concentration in the DGEBA composite, owing to the aggregation effect. The dc conductivity and impedance spectroscopy of the DGEBA/PANI-Ag composite was measured at different PANI-Ag concentrations in the DGEBA network. The electrical dc conductivity of the PANI-Ag was 35.1 S cm⁻¹ and was dependent of the PANI-Ag concentration in DGEBA matrix. The real and imaginary part of impedance complex measurements indicates a strong interfacial polarization at low frequency for both PANI-Ag and DGEBA/PANI-Ag, respectively. The imaginary part of impedance complex Im(Z) data decrease with the PANI-Ag hybrid concentration in the frequencies range of 10²–10⁶ Hz. The dependence of the Im(Z) on the frequency exhibited a relaxation process in both, PANI-Ag and DGEBA/PANI-Ag composite with 10 phr of PANI-Ag powder.