Spectroscopic Analysis of Cotton Treated with Neutralized Maleinized Soybean Oil

Water-soluble vegetable oil derivatives were synthesized and investigated as biobased reagents for cellulosic textiles. Maleinized soybean oil (MSO), having an acid value of 156 mg KOH/g, was neutralized with ammonium hydroxide to render it water soluble. Infrared spectroscopy indicated the formation of ester linkages during the cure of MSO treated textiles. Therefore, the formation of anhydride and amide intermediates upon heating ammonia neutralized MSO were investigated. Construction of the cyclic anhydride was observed as a pathway to esterification; however, amidation was not observed among this ammonia neutralized MSO. Neutralization of MSO with ethanolamine and triethylamine yielded secondary and tertiary amides but not esters at 160 °C.     

RECOVERY AND SEPARATION OF PLATINUM GROUP METALS USING IMPREGNATED RESINS CONTAINING ALAMINE 336

ABSTRACT

The kinetics and equilibrium extraction of pd(II) pt(IV) and RH (III) from hydrochloric acid media using impregnated resins containing Alamine 336 impregnated onto Amberlite XAD2 were studied and compared. While Rh( III) was hardly extracted, Pd( II) and Pt( IV) extraction could be explained by the formation of ( R₃ NH⁺ )₂ MCL_n ^{? 2} complexes: n= 4 for Pd( H) and n= 6 for Pt( TV) Stripping and concentration of the extracted PGMs were assayed with HC1, HC10₄ and thiourea. Straightforward metal separations were designed on the basis of the results obtained in the single metal experiments, and selective co-extraction of Pd( II) and Pt( TV) from Rh( III)at low HC1 concentrations, as well as partial separation between Pd( ll) and Pt( IV) at high acid concentrations, were achieved.     

Conformational Analysis of the Mannosidase Inhibitor Kifunensine: A Quantum Mechanical and Structural Approach

The varied yet family‐specific conformational pathways used by individual glycoside hydrolases (GHs) offer a tantalising prospect for the design of tightly binding and specific enzyme inhibitors. A cardinal example of a GH‐family‐specific inhibitor, and one that finds widespread practical use, is the natural product kifunensine, which is a low‐nanomolar inhibitor that is selective for GH family 47 inverting α‐mannosidases. Here we show, through quantum‐mechanical approaches, that kifunensine is restrained to a “ring‐flipped” ¹C₄ conformation with another accessible, but higher‐energy, region around the ^1,4B conformation. The conformations of kifunensine in complex with a range of GH47 enzymes—including an atomic‐level resolution (1 Å) structure of kifunensine with Caulobacter sp. CkGH47 reported herein and with GH family 38 and 92 α‐mannosidases—were mapped onto the kifunensine free‐energy landscape. These studies revealed that kifunensine has the ability to mimic the product state of GH47 enzymes but cannot mimic any conformational states relevant to the reaction coordinate of mannosidases from other families.     

Development of kinetic models for gas phase MTBE production

Methyl tert-butyl ether (MTBE) synthesis is nowadays carried out using resin catalysts. An alternative zeolitic catalyst is presented in this study. This catalyst presents better mechanical and thermal strength, as well as slightly better performance. It is capable of enduring temperatures that would deactivate resin catalyst. The microkinetic study presented below indicates the importance of temperature and molar feed ratio depending on the catalyst used. Activation energy was found to be 15.7 kcal/g mol. Reaction mechanism suggested involved adsorption of isobutylene on two active sites and methanol on one active site.     

The Influence of Egocentrism and Focalism on People's Optimism in Competitions: When What Affects Us Equally Affects Me More.

Six experiments investigated people's optimism in competitions. The studies involved hypothetical and real competitions (course grades in Experiments 1 and 2, a trivia game in Experiments 3-5, and a poker game in Experiment 6) in which the presence of shared adversities and benefits (factors that would generally hinder or help the absolute performance of all competitors) was manipulated. Shared adversities tended to reduce people's subjective likelihoods of winning, whereas shared benefits tended to increase them. The findings suggest that when people judge their likelihood of winning, their assessments of their own strengths and weaknesses have greater impact than their assessments of their competitors' strengths and weaknesses. We identify egocentrism and focalism as two causes of the bias. The experiments revealed moderators of this bias, but also illustrated its robust nature across a variety of conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of the putative transmembrane segment M3 in gating of neuronal nicotinic receptors

The involvement of some structural domains in the gating of the neuronal nicotinic acetylcholine receptor (AChR) was studied by expressing functional alpha7/alpha3 chimeric subunits in Xenopus oocytes. Substitution of the M3 transmembrane segment in the alpha7 subunit modifies the kinetic properties of the chimeric AChRs as follows: (a) a 6-fold reduction in the maximal current evoked by nicotinic agonists, (b) a 10-fold decrease in the macroscopic desensitization rate, (c) an increase of almost 1 order of magnitude in the apparent affinity for acetylcholine and nicotine, and (d) a decrease in the affinity for alpha-bungarotoxin. Computer simulations showed that the first three effects could be accounted for by a simple kinetic model in which chimeric AChRs presented a smaller ratio of the gating rates, beta/alpha, and a slightly slower desensitization rate. It is concluded that the M3 domain influences the gating of neuronal AChRs.     

Effects of individual differences in working memory on performance and trust with various degrees of automation

Previous studies showed performance benefits with correct automation, but performance costs when the automation was incorrect (i.e. provided an incorrect course of action), particularly as degrees of automation increased. Automation researchers have examined individual differences, but have not investigated the relationship between working memory and performance with various degrees of automation that is both correct and incorrect. In the current study, working memory ability interacted with automation reliability and degree of automation. Higher degrees of correct automation helped performance while higher degrees of incorrect automation worsened performance, especially for those with lower working memory. Lower working memory was also associated with more trust in automation. Results illustrate the interaction between degree of automation and individual differences in working memory on performance with automation that is correct and automation that fails.     

Electronic properties of the organic superconductor (BEDO-TTF)2ReO4(H2O)

The electronic properties of the organic superconductor (BEDO-TTF)₂ReO₄(H₂O) were investigated by temperature dependent resistivity, FT - IR reflectivity and magnetoresistance measurements. Shubnikov-de Haas (SdH) oscillations were observed in magnetic fields up to 24T in the temperature range from 0.5K to 4.2K. The two observed SdH frequencies of 76 and 37 Tesla correspond very well to two cross-sectional areas of the Fermi surface obtained from a tight binding calculation for a hole and an electron pocket.     

On the improvement of annual performance of solar thermal power plants through exergy management

Advancing in the learning curve of solar thermal power plants (STPP) requires detailed analysis for reducing exergy losses in the energy conversion chain. This requirement should be applied to any configuration proposed for the solar field and the power block. The aim of this work is to perform this type of analysis for two ways of structuring the power plant. The first plant structure consists of a subdivision of the solar collector field into specialized sectors with specific goals conveying different requirements in temperature. The second plant structure is based on a dual thermal energy storage system with a defined hierarchy in the storage temperature. The subdivision of the solar field into different sectors reduces the exergy losses in the heating process of the working fluid. Moreover, the average temperature of the heat transfer fluid in the solar field decreases when it is compared to the conventional solar field, reducing this way the exergy losses in the collectors. The dual thermal energy storage system is devised for keeping the exergy input to the power block at its nominal level for long periods of time, including post‐sunset hours. One of the storage systems gathers a fluid heated up to temperatures above the nominal value and the second one is the classical one. The combination of both allows the manager of the plant to keep the nominal operation of the plant for longer periods than in the case of classical system. Numerical simulations performed with validated models are the basis of the exergy analyses. The configurations are compared to a reference STPP in order to evaluate their worth. Furthermore, the behaviour of the configurations is analysed to study the irreversibility of the included devices. Special attention is paid to the storage systems, as they are a key issue in both plant structures. Copyright © 2013 John Wiley & Sons, Ltd.