Effect of different loss mechanisms in SiGeSn based mid-infrared laser

We have analyzed the mid-infrared SiGeSn based Barrier-Well-Barrier Heterostracture and calculated the transparency carrier density and corresponding current density for the structure. The effects of different loss mechanisms like free carrier absorption, spontaneous recombination and Auger recombination processes on the transparency current density have been examined. It is shown that, the transparency current density increases significantly with the injected carrier density. Different scattering processes like acoustic phonon scattering and intervalley optical phonon scattering are taken into consideration for this analysis of free carrier absorption mechanisms.

     

The effects of local structural relaxation on aluminum siting within H-ZSM-5

Semiempirical molecular orbital calculations have been performed to study aluminum siting in H-ZSM-5 zeolites. Local structural rearrangements upon substituting aluminum (with a charge compensating proton) for silicon are found to be important. The T12 site is found to be the most preferred site for aluminum substitution. However, the calculated energetics for substitution show that several tetrahedral sites are energetically comparable with regard to aluminum siting. Results pertaining to the electronic properties of the acidic site upon aluminum substitution at each of the twelve distinct tetrahedral sites are presented. The acidic center is found to be a rather soft species, with the HOMO-LUMO energy gap being roughly 8 eV.     

Influence of Linker Length on Conformational Preferences of Glycosylated Sugar Amino Acid Foldamers

Glycosylation of foldamers derived from furanoid sugar amino acids with mannose and a propyltriazole linker results in an unprecedented 16/10 mixed‐turn structure in the glycopeptides in water, with a preference for the higher‐order structure irrespective of the stereochemistry of the starting foldamer. This is in stark contrast to the structures displayed by the same oligomers in water when mannosylated with a two‐carbon‐shorter methyltriazole linker: 16‐membered turn structure in the cis‐foldamer and 10‐membered in its trans congener. This demonstrates the defining influence of the linker length on the structural preference of these novel glycopeptide mimics.     

Optimization of media components for the production of palm vinegar using response surface methodology

This study examines palm vinegar fermentation and applies response surface methodology to determine an optimal composition of palm vinegar fermentation media. Two major independent variables (carbon and nitrogen source) were evaluated for their individual and interactive effect on vinegar production. The highest yield of acetic acid concentration, 70.97 g/L, was obtained through an optimal media composition of glucose, sucrose and glycerol at a ratio of 12:15:2 g/L. When combined with optimal nitrogen sources (diammonium hydrogen phosphate and urea at a ratio of 3:1 g/L), the resulting palm vinegar contained vitamins B3 and B5, ascorbic acid and folic acid in significantly higher quantities than raw palm juice. Concentrations of trace elements such as Cu, Zn and Na were also increased through vinegar fermentation relative to palm wine. Furthermore, investigation of the antioxidant activity of the fermented palm vinegar with the free radical scavenging assay method showed protection of DNA from damage generally induced by hydrogen peroxide radicals. Copyright © 2014 The Institute of Brewing & Distilling     

Nutritional status of adult Santal men in Keonjhar District, Orissa, India

BACKGROUND: Although tribal people constitute a sizable proportion of India's population, there is little information on their anthropometric and nutrition status. OBJECTIVE: The present study was undertaken to study the anthropometric characteristics of adult Santal males. It also attempted to evaluate their nutritional status based on body-mass index (BMI) and mid-upper-arm circumference (MUAC). METHODS: A cross-sectional study was conducted of adult (aged > 18 years) male Santals, a tribal population of Keonjhar District, Orissa, India. A total of 332 Santals from five villages (Gourshinga, Kashibera, Kumunia, Majhisahi, and Sonatangri) in the Anandapur Region of Keonjhar District were included in the study. These villages are located approximately 150 km from Bhubaneswar, the provincial capital of Orissa. Anthropometric measurements, including height, weight, and MUAC, were performed according to a standard protocol. Nutritional status was evaluated on the basis of internationally accepted cutoff points of BMI and MUAC. RESULTS: The mean height, weight, MUAC, and BMI of the men were 162.5 cm, 51.7 kg, 23.7 cm, and 19.6 kg/m2, respectively. The prevalence of undernutrition (chronic energy deficiency [CED]) based on BMI was 26.2%; 3.3%, 3.9%, and 19.0% had grades III, II, and I CED, respectively. According to MUAC cutoff points, the prevalence of undernutrition was 33.7%. CONCLUSIONS: The level of undernutrition among adult Santal males was high. Appropriate nutritional intervention programs should be implemented immediately.     

A multi-criteria decision support model for optimal cotton fibre blending

As cotton is a natural fibre, its different physical properties are likely to immensely vary depending on the variations in its seed type, area where it is grown and the climatic conditions. This may affect the characteristics of the final products. Blending is a process of combining different cotton fibres together to synergize their physical properties. For successful blending, it is always required to determine the types of the constituent fibres in the final mix and their appropriate proportions. In this paper, a multi-criteria optimization model in the form of a decision support framework is developed while integrating preference ranking organization method for enrichment of evaluations (PROMETHEE II and V) and geometrical analysis for interactive aid (GAIA) approach. This model is observed to have great potentiality in ranking the considered cotton fibre alternatives from the best to the worst, identifying the top ranked cotton fibres and finding out the constituent fibres in the final blend along with their proportions. Two cotton fibre varieties, such as the Egyptian and Ethiopian types are considered here to demonstrate the applicability of the developed model.     

Combined influences of viscous dissipation,non-uniform Joule heating and variable thermophysical properties on convective heat transfer in microtubes

This study presents a comprehensive investigation on hydrodynamic and thermal transport properties of mixed electroosmotically and pressure driven flow in microtubes. Particular emphasis is given to investigating the combined consequences of viscous dissipation, non-uniform Joule heating, and variable thermophysical properties. Analytical solutions are obtained using the Debye–Hückel linearization and constant fluid properties assumption, while a numerical solution is presented for variable fluid properties and non-uniform distribution of Joule heating. The results indicate that, viscous heating effect is pronounced significantly when a favorable pressure gradient exists and cannot be neglected at low values of the dimensionless Debye–Hückel parameter. Moreover, uniform Joule heating assumption, even at low zeta potentials, may reduce the accuracy of the predicted thermal features considerably. The wall shear stress is found to be strongly dependent upon the zeta potential, which is underestimated by the Debye–Hückel linearization. Compared with the constant fluid properties case, decreasing electrical resistivity of the fluid by increasing temperature, amplifies the total energy generation due to the Joule heating and reduces the Nusselt number.