Configurational assignments of the diastereomers of 3,3′‐(1,2‐ethanediyl)bis[2‐(3‐fluorophenyl)‐5‐methyl‐4‐thiazolidinone] derivative with four stereogenic centers

Diastereomers of antiinflammatory/analgesic and antihistaminic 3,3′[(1,2‐ethanediyl)bis(2‐aryl‐4‐thiazo‐lidinone)] derivatives possessing two stereogenic centers (indicated as BIS 2*C) have been widely investigated in recent years. The 5,5′‐dimethyl analogues (BIS 4*C), now reported, have been synthesized by reaction of (±) α‐mercaptopropionic acid and N,N'‐di(3‐fluorobenzyliden)ethylenediamine. Because the 2 and 2′carbons bear the same groups and similarly the 5 and 5′ carbons, and the latter groups are different from the former, four enantiomeric pairs and two meso forms exist in this situation. These diastereomers were identified by the concerted use of nmr spectroscopy and hplc on chiral stationary phase.     

Reactions of cyclic oxalyl compounds, 43: Synthesis and thermolysis of fused 1‐arylaminopyrrolones

Fused N‐(di)arylamino‐pyrrol‐2,3‐diones 1 are reacted with diphenylketene, thiosemicarbazide or 1,2‐diaminobenzene to afford the 3‐diphenylmethylene pyrrolones 2 , the thiosemicarbazones 4 or the quinoxaline derivatives 5 as well as 6 , respectively. Thermolysis of 2b,c,e,f,6b and the pyrrolo‐quinoxaline 8 afford the corresponding N‐deaminated products 3, 7 and 9 . Rearrangements into diazapropellanes following a thermally initiated Fischer ‐ indolization as originally expected do not occur.     

Thermal Diffusivity and Adsorption Kinetics of Silica-Gel/Water

There have been performed experimental measurements of effective thermal conductivity of silica-gel for a stagnant cylindrical fixed bed under transient and steady state conditions in the presence of dry air at different pressures and for different amounts of adsorbed water. The Bauer-Schlünder and Kunii-Smith models have been used to identify the thermal solid conductivity of silica gel pellets from measurements of the conductivity in an adsorbent bed. Sorption rates of water vapor in silica gel were measured using a single-step thermal method by monitoring the sample surface temperature by infrared detection. In order to obtain the mass diffusivity it is necessary to match the numerical solution of the mathematical model to the experimental data.     

Xylanase production by Aspergillus awamori in solid-state fermentation and influence of different nitrogen sources

The use of purified xylan as a substrate for bioconversion into xylanases increases the cost of enzyme production. Consequently, there have been attempts to develop a bioprocess to produce such enzymes using different lignocellulosic residues. Filamentous fungi have been widely used to produce hydrolytic enzymes for industrial applications, including xylanases, whose levels in fungi are generally much higher than those in yeast and bacteria. Considering the industrial importance of xylanases, the present study evaluated the use of milled sugarcane bagasse, without any pretreatment, as a carbon source. Also, the effect of different nitrogen sources and the C∶N ratio on xylanase production by Aspergillus awamori were investigated, in experiments carried out in solid-state fermentation. High extracellular xylanolytic activity was observed on cultivation of A. awamori on milled sugarcane bagasse and organic nitrogen sources (45 IU/mL for endoxylanase and 3.5 IU/mL for β-xylosidase). Endoxylanase and β-xylosidase activities were higher when sodium nitrate was used as the nitrogen source, when compared with peptone, urea, and ammonium sulfate at the optimized C∶N ratio of 10∶1. The use of yeast extract as a supplement to the these nitrogen sources resulted in considerable improvementin the production of xylanases, showing the importance of this organic nitrogen source on A. awamori metabolism.     

Strong Reflexivity of Abelian Groups

A reflexive topological group G is called strongly reflexive if each closed subgroup and each Hausdorff quotient of the group G and of its dual group is reflexive. In this paper we establish an adequate concept of strong reflexivity for convergence groups. We prove that complete metrizable nuclear groups and products of countably many locally compact topological groups are BB-strongly reflexive.     

Teacher Rationales for Scoring Students' Problem Solving Work

This article presents the scores teachers assigned to samples of actual students' problem-solving work and the rationales teachers provided for these scores. These rationales may reflect teachers' values relative to aspects of mathematical problem solving. It may be that when teachers can express rationales for scoring students' work, they are able to justify their evaluation of what students can “know and do” in mathematics.     

Inductive Construction of the Loop Transform for Abelian Gauge Theories

We construct the loop transform in the case of Abelian gauge theories as a unitary operator given by the inductive limit of Fourier transforms on tori. We also show that its range, i.e. the space of kinematical states of the quantum loop representation, is the Hilbert space of square integrable complex valued functions on the group of hoops.     

Applications of Approximation Theory to thermographic images in earthquake engineering

In this paper we show some new applications of the approximation theory, by means of the multivariate sampling Kantorovich operators, to thermographic images in seismic engineering. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Effect of the oxygen transfer coefficient on xylitol production from sugarcane bagasse hydrolysate by continuous stirred-tank reactor fermentation

The effect of the oxygen transfer coefficient on the production of xylitol by biocon version of xylose present in sugarcane bagasse hemicellulosic hydrolysate using the yeast Candiada guilliermondii was investigated. Continuous cultivation was carried out in a 1.25-L fermentor at 30°C, pH 5.5, 300 rpm, and a dilution rate of 0.03/h, using oxygen transfer coefficients of 10,20, and 30/h. The results showed that the microbial xylitol production (11 g/L) increased by 108% with the decrease in the oxygen volumetric transfer coefficient from 30 to 20/h. The maximum values of xylitol productivity (0.7g/[L…h]) and yield (0.58 g/g) were obtained at k _L a 20/h.     

Bis(μ‐succinato‐O,O′:O′′,O′′′)bis[bis(2‐amino‐1,3‐benzothiazole‐N3)copper(II)]

In the title dimeric complex, [Cu₂(C₄H₄O₄)₂(C₇H₆N₂S)₄], which possesses a centre of symmetry, the Cu atoms are enclosed in a 14‐membered ring. They adopt a distorted square‐bipyramidal (4+2) coordination. The four closest donor atoms are two N atoms of 2‐amino­benzo­thiazole ligands and two O atoms of the succinate carboxylate groups. They form a square‐planar cis arrangement, with an average Cu—N distance of 2.003 (3) Å and Cu—O distances of 1.949 (3) and 1.965 (3) Å. Two longer Cu—O bonds of 2.709 (3) and 2.613 (3) Å involving the remaining O atoms of the carboxylate groups complete the sixfold coordination of the Cu atoms. The H atoms of each amino group of the 2‐amino­benzo­thiazole molecules form intra‐ and inter­molecular N—H?O hydrogen bonds. A nearly perpendicular inter­molecular C—H?Cg interaction (Cg is the centroid of the imidazole ring) is observed. The intramolecular Cu?Cu distance is 6.384 (2) Å.