595 research outputs found

    MICROWAVE DRYING OF ALOE VERA (ALOE BARBADENSIS MILLER): MATHEMATICAL MODELING, KINETICS AND MASS TRANSFER ASPECTS

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    Aloe vera has extensive application in food and pharmaceutical industry in fact contains 97 percent of water. It’s perishable in nature and poor shelf life makes it essential to study the drying characteristics of aloe vera. The objective of this present study is to investigate the effect of different microwave (MW) respective power levels (180 , 360 ,540 , 720 and 900 Watts ) regarding the  moisture ratio (MR), drying rate (DR), effective moisture diffusivity (EMD), specific energy consumption (SEC) and drying efficiency (DE) of aloe vera. The drying process took 70 - 26 .5 minutes for attainment of equilibrium moisture content. A mathematical model done by Midilli et al.  is considered to be the best and most suitable for a drying conditions among the various thin layer models. The effective moisture diffusivity value at 180 Watts (W) of MW power was found as 4.5 × 10-8 m2/sec. while it was raised to 9.45 x10-7 m2/sec at 900 W in this study. Lowest energy consumption 1.4 MJ/Kg water and maximum drying efficiency occurred at higher microwave power level 900 Watts due to less drying duration (time)

    FUZZY COST OVERRUN ANALYSIS MODEL FOR CONSTRUCTION PROJECT

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    Now a day’s many factors which affect the productivity in construction project. Due to this delay factors time and cost overrun in a project. In this research helps to identify the most important factors that affect the productivity and form a modelling using fuzzy logic. The data’s were collected through questionnaire survey from engineers, contractors and clients worked within the various construction industries. The collected data’s were analyzed using relative importance index (RII) and ranking the factors based on percentage of relative importance and also this paper presents an application of fuzzy logic for developing delay factors causes cost overrun  model using Fuzzy toolbox of MATLAB Program software. The results can facilitate the construction industry to take measures the delay factors causes cost overrun in construction projects

    Synthesis and solution properties of comblike polymers from octadecyl methacrylate and acrylic acid

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    Amphiphilic polymers consisting of a statistical distribution of octadecyl methacrylate (ODMA) and acrylic acid in respective molar ratios of 83-22 and 17-78 mol% and in a molecular-weight range of 2.35-4.70×104 gmol-1 have been synthesized. The series of polymers consisting of various mole fractions of ODMA and acrylic acid are expected to exhibit unique characteristics resembling ionomer to hydrophobically modified polyelectrolytes. The changes in the I3/I1 emission intensity ratios of pyrene, occurring in the presence of tetrahydrofuran (THF) solutions of the polymers have been taken as the main basis for inferring solution structures. The polymers are found to form random-coil to collapsed-coil/aggregated structures in THF solvent depending on the copolymer compositions. The polymer consisting of 83 mol% ODMA and 17 mol% acrylic acid behaves as an ionomer, capable of forming collapsed-coil structures at concentrations of 0.02 gml-1 and above as shown by a very high I3/I1 of 1.20 (I3/I1 of pyrene in THF is 0.85). In contrast, the poly(octadecyl methacrylate) homopolymer and the sets of copolymers consisting of a very high proportion of acrylic acid to an extent of 73 mol% and above contribute to almost negligible or very small changes in I3/I1 similar to the homopolymer, poly(octadecyl methacrylate), suggesting the formation of random-coil structures

    How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

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    Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications

    Electrochemical behaviour of some alkyl substituted N-hydroxy-2,6-diarylpiperidin-4-one thiosemicarbazone and the antifungal studies of the products

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    A series of 3-ethyl-2,6-diarylpiperidin-4-one thiosemicarbazone and 3,5-dimethyl-2,6-diarylpiperidin-4-one thiosemicarbazone were synthesised. The thiosemicarbazones were subjected to cyclic voltammetric study using graphite electrode with variable scan rate at moderate acidic conditions maintained in the electrolytic solution. The reduction takes place by two electron transfer and the reaction is pH dependent. The reduced products were isolated and purified by column chromatography. The structure was proved by 1H and 13C NMR spectroscopy. The electrode process was found to be irreversible and diffusion controlled. Further the products were analysed for anti fungal activity in which nitro substituted compound showed high inhibition towards the fungi Asperillus nige

    Statistical Screening of Supplementary Nitrogen Source for Enhanced Production of L-Asparaginase by Aspergillus terreus 1782

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    In the present work, Latin Square Design (LSD) was applied to find the best supplementary nitrogen source for extracellular L-asparaginase production by Aspergillus terreus MTCC 1782 using corn flour as substrate in submerged fermentation. The independent effect of supplementary nitrogen source such as ammonium chloride, urea and sodium nitrate was studied on growth and production of L-asparaginase by A. terreus. Statistical significance of the nitrogen sources was studied by performing analysis of variance (ANOVA) and graphical ANOVA for LSD using Data plot software. It was found that there is no significant difference on growth due to the change in supplementary nitrogen source studied. Urea was identified as best supplementary nitrogen source with mean L-asparaginase production of 33.25 IU mL–1 and mean biomass production of 12.99 mg mL–1

    On Weakly Symmetric and Weakly Conformally Symmetric Spaces Admitting Veblen Identities

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    In the present paper some properties involving curvature tensor,conformal curvature tensor, Ricci tensor and scalar curvature, on weakly symmetric, weakly conformally symmetric and pseudo symmetric spaces are obtained

    Greener synthesis and characterization of cadmium-tellurium quantum dots using aqueous extract of waste orange peel

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    56-61Cadmium-Tellurium quantum dots are inorganic semiconductor material. In the present study, highly stable Cadmium-Tellurium (CdTe) quantum dots with good optical properties were successfully synthesized by using waste orange peel extract. Fourier-transform infrared spectroscopy (FTIR) identified the presence of hydroxyl, carboxyl and amine groups. Multifunctional X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of cadmium and tellurium. The average size of the quantum dots was found to be 6nm using Transmission Electron Microscopy (TEM). The cubic zinc blende type crystalline structure of quantum dots was confirmed by X-ray powder diffraction (XRD). Thermal stability was studied using thermo-gravimetric analysis (TGA). The influence of temperature with respect to mass change of 8% was observed at 200°C. The high luminescence property exhibits at the wavelength of 502 nm were investigated using photoluminescence analysis (PL) and the blue shift is confirmed by UV-Visible spectroscopy

    Ecology of benthic ostracoda from off Rameswaram, southeast coast of india

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    Ostracoda are bivalve crustacean that live in marine through brackish environment. The study area is off Rameswaram in the Palk Bay. The latitude and longitude are N 9°17' and from E 79º19' to 79º25'. As Rameswaram and its environ experiences four types of seasons in a year, namely, Winter (January - March), Summer (April - June), Southwest monsoon (July - September) and Northeast monsoon (October - December), ten sediment and bottom water samples were collected during every season, totaling to forty in a year. The Depth, Temperature, pH, Salinity, Dissolved oxygen and Nutrients regarding water samples and CaC03 and Organic matter in sediments were determined apart from the type of sediment. A portion of the sediment sample from each location during every season were preserved in the field using 10% formalin and latter processed in the laboratory for determining and counting of living and total population of benthic Ostracoda. Individual species of Ostracoda were identified and their living and total population were determined from every samples for all seasons. Based on the size of the population, widespread and abundantly occurring nature, the ecology of six species were computed. The six species are 1) Loxoconcha lilljeborgii Brady, 2) Mutilus pentoekensis (Kingma), 3) Neocytheretta murilineata Zhao and Whatley, 4) Neomonoceratina iniqua Brady, 5) Tanella gracilis Kingma, and 6) Xestoleberis variegata Brady. The population size of all these six species exceeds 62% of the total population size during all the seasons
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