Isolation,characterization, and antifungal application of a biosurfactant produced by Enterobacter sp. MS16

Isolate MS16 obtained from diesel contaminated soil, identified as Enterobacter sp. using 16S rRNA gene analysis produced biosurfactant when grown on unconventional substrates like groundnut oil cake, sunflower oil, and molasses. Of these carbon substrates used, sunflower oil cake showed highest biosurfactant production (1.5 g/L) and reduction in surface tension (68%). The biosurfactant produced by MS16 efficiently emulsified various hydrocarbons. The carbohydrates and fatty acids of the biosurfactants were studied using TLC, FTIR, NMR, and GC‐MS. The carbohydrate composition as determined by GC‐MS of their alditol acetate derivatives showed the predominance of glucose, galactose and arabinose, and hydroxyl fatty acids of chain length of C₁₆ and C₁₈ on the basis of FAMEs analysis. Biosurfactant showed antifungal activity and inhibited the fungal spore germination. Practical applications : Enterobacter sp., MS16 produces a biosurfactant composed of carbohydrates and fatty acids which exhibits excellent surface active properties. Use of industrial wastes for biosurfactant production is economical and facilitates the industrial production of this biosurfactant which has potential antifungal activity.     

Morphological variations in cadmium sulfide nanocrystals without phase transformation

A very novel phenomenon of morphological variations of cadmium sulfide (CdS) nanorods under the transmission electron microscopy (TEM) beam was observed without structural phase transformation. Environmentally stable and highly crystalline CdS nanorods have been obtained via a chemical bath method. The energy of the TEM beam is believed to have a significant influence on CdS nanorods and may melt and transform them into smaller nanowires. Morphological variations without structural phase transformation are confirmed by recording selected area electron diffraction at various stages. The prepared CdS nanorods have been characterized by X-ray powder diffraction, TEM, UV-Vis spectroscopy, and photoluminescence spectroscopy. The importance of this phenomenon is vital for the potential application for CdS such as smart materials.     

Polypropylene and potato starch biocomposites: Physicomechanical and thermal properties

To determine the possibility of using starch as biodegradable filler in the thermoplastic polymer matrix, starch‐filled polypropylene (PP) composites were prepared by extrusion of PP resin with 5, 10, 15, and 20 wt % of potato starch in corotating twin‐screw extruder. The extruded strands were cut into pellets and injection molded to make test specimens. These specimens were tested for physicomechanical properties such as tensile and flexural properties, Izod impact strength, density, and water absorption. These PP composites were further characterized by melt flow index (MFI), vicat softening point (VSP), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) techniques. It was found that, with increase in starch content, tensile modulus, flexural strength, and flexural modulus of the PP composites increased along with the increase in moisture, water absorption, and density, while retaining the VSP; but, tensile strength and elongation, impact strength, hardness, and MFI of the PP composites also decreased. DSC analysis of the PP composite revealed the reduction in melting temperature, heat of fusion, and percentage of crystallization of PP with increase in starch content. Similarly, TGA traces display enhanced thermal degradability for PP as starch content increases. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and in vitro Evaluation of West Nile Virus Protease Inhibitors Based on the 1,3,4,5‐Tetrasubstituted 1H‐Pyrrol‐2(5H)‐one Scaffold

West Nile virus (WNV), a member of the Flaviviridae family, is a mosquito‐borne pathogen that causes a large number of human infections each year. There are currently no vaccines or antiviral therapies available for human use against WNV. Therefore, efforts to develop new chemotherapeutics against this virus are highly desired. In this study, a WNV NS2B–NS3 protease inhibitor with a 1,3,4,5‐tetrasubstituted 1H‐pyrrol‐2(5H)‐one scaffold was identified by screening a small library of nonpeptidic compounds. Optimization of this initial hit by the synthesis and screening of a focused library of compounds with this scaffold led to the identification of a novel uncompetitive inhibitor ((?)‐ 1a16 , IC₅₀=2.2±0.7 μM ) of the WNV NS2B–NS3 protease. Molecular docking of the chiral compound onto the WNV protease indicates that the R enantiomer of 1a16 interferes with the productive interactions between the NS2B cofactor and the NS3 protease domain and is thus the preferred isomer for inhibition of the WNV NS2B–NS3 protease.     

Simulation and optimization of extractive distillation sequence with pre-separator for the ethanol dehydration using n-butyl propionate

Extractive distillation is the most promising alternative for the ethanol-water separation than azeotropic and pressure swing distillation using suitable solvent n-Butyl propionate. We have studied, simulated, optimized and economically evaluated the separation of a mixture of 50 mole% ethanol and 50 mole% water to treat the 16 Kmol/hr (512.67 kg/hr) of the original mixture. Rigorous simulation and optimization has been carried out by means of a software CHEMCAD version 6.5 using thermodynamic model UNIQUAC with binary interaction parameters. The simulations allow us to conclude that extractive distillation is more economical and trustworthy than pressure swing distillation due to the relative pressure insensitive nature of the ethanol-water mixture after the azeotropic composition. The separation of 99.7% of ethanol from ethanol water mixture claim by Mulia-Soto, Flores-Tlacuahuac, 2011 is contradictory as the feasibility for the operating pressure of 10 atm with or without heat integration.     

Weighted adaptively grouped multilevel space time trellis codes

In existing grouped multilevel space-time trellis codes (GMLSTTCs), the groups of transmit antennas are predefined, and the transmit power is equally distributed across all transmit antennas. When the channel parameters are perfectly known at the transmitter, adaptive antenna grouping and beamforming scheme can achieve the better performance by optimum grouping of transmit antennas and properly weighting transmitted signals based on the available channel information. In this paper, we present a new code designed by combining GMLSTTCs, adaptive antenna grouping and beamforming using the channel state information at transmitter (CSIT), henceforth referred to as weighted adaptively grouped multilevel space time trellis codes (WAGMLSTTCs). The CSIT is used to adaptively group the transmitting antennas and provide a beamforming scheme by allocating the different powers to the transmit antennas. Simulation results show that WAGMLSTTCs provide improvement in error performance of 2.6 dB over GMLSTTCs.     

Closed form expressions for ABER and capacity over EGK fading channel in presence of CCI

Goal of next generation wireless communication system is to achieve very high data rate. Femto-cell is one of the possibilities to achieve the above target. However, co-channel interference (CCI) is the important concern in femto-cell. This paper presents closed form expressions for average bit error rate (ABER) and capacity for different adaptive schemes under extended generalised-K (EGK) fading channel in the presence of CCI. A novel conditional unified expression (C_UE) is derived, which results different conditional error probability and normalised average capacity. Using C_UE, a generic expression for ABER is obtained. In addition, closed form expressions for ABER for different modulation schemes under EGK fading channel in presence of CCI are also derived. Further, it is shown that generic ABER expression results into ABER of different modulation schemes. Besides, the closed form expressions of capacity for different adaptive schemes under EGK in presence of CCI are derived. Finally, analytical and simulated results are obtained with excellent agreement.     

Configuration of manufacturing strategy decision areas in line production system: five case studies

The objective of this research is to study the configuration of decisions in manufacturing decision areas for a line production system. A case study approach is used by analyzing the decision choices selected by five case companies that satisfy characteristics of line production system. The paper identifies decision choices specific to line shop as well as decisions that are influenced by non-process specific factors such as competitive priorities (order winner), strategic orientation of manufacturing (stages in H–W model), top management decisions, and size of the company. Findings on several decision choices are new to manufacturing literature. These research findings should be helpful to practitioners and researchers.     

Control structures in hypothesis spaces: the influence on learning

In any learnability setting, hypotheses are conjectured from some hypothesis space. Studied herein are the influence on learnability of the presence or absence of certain control structures in the hypothesis space. First presented are control structure characterizations of some rather specific but illustrative learnability results. The presence of these control structures is thereby shown essential to maintain full learning power. Then presented are the main theorems. Each of these non-trivially characterizes the invariance of a learning class over hypothesis space V and the presence of a particular projection control structure, called proj, in V as: V has suitable instances of all denotational control structures. In a sense, then, proj epitomizes the control structures whose presence need not help and whose absence need not hinder learning power.