701 research outputs found

    Development of Technology for Large Scale Production of Titanium Sponge

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    Intensive investigations on the development of titanium metal production technology had been carried out during 1965-1975 at the Bhabha Atomic Research Centre, Bombay and at the Nuclear Fuel Complex, Hyderabad. The Defence Metallurgical Research Laboratory, Hyderabad has set up a ‘Titanium Sponge Experimental Facility’ with a capacity to produce 100 tonnes of sponge per annum in 2000 kg batches by the Kroll’s process with a view to optimising technology for large scale production.The paper presents an outline of the experimental facility and discusses the various considerations that have gone into the design of equipment, materials of construction, process selection, etc. The facility has gone into operation in March,1985. The results obtained so far are encouraging

    Structural heat treatments against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae): effect of flour depth, life stage and floor.

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    The effect of high temperatures (50-60°C) and two levels of sanitation (~0.5 and 43 g of flour), on mortality of eggs, young larvae, old larvae, pupae, and adults of the red flour beetle, Tribolium castaneum, were evaluated during heat treatment of a pilot flour mill at Kansas State University. The mill was heated once during 13-14 May 2009 and once during 25-26 August 2009. Each of the heat treatments lasted 24 h. Bioassay boxes, with life stages of T. castaneum and temperature sensors confined in small compartments, were placed in 25 locations across all five mill floors. Temperature data showed that the mean time to 50°C based on the two treatments ranged from 10.39 to 17.18 h, and the mean time above 50°C ranged from 6.01 to 13.63 h. The mean maximum temperatures attained ranged from 50.7 to 61.4°C. In general, temperatures were lower in compartments with 43 g of flour when compared with compartments with 0.5 g of flour. Temperatures were also lower on the first floor than on the remaining floors. In box bioassays, essentially none of the life stages survived the 24 h heat treatment (99-100% mortality), except on the first floor. The survival of insects, especially on the first floor, is related to how quickly temperatures reached 50°C and how long temperatures were held between 50 and 60°C, and the maximum temperatures attained at a given location. There were only small differences in mortality between the two levels of sanitation. These results show that heat treatment of flour mills can control all life stages of T. castaneum in 24 h. Keywords: Tribolium castaneum, Heat treatment, Sanitation, Life stages, Methyl bromide alternative

    Heat treatment: A viable methyl bromide alternative for managing stored-product insects in food-processing facilities

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    Heat treatment involves raising and maintaining temperatures of grain storage structures, warehouses, and food-processing facilities between 50 to 60°C to manage stored-product insect species. The duration of heat treatment is application-specific and may vary from 6 h for an empty storage facility to 24 h for an entire food-processing facility. Laboratory and commercial trials with high temperatures during the last decade, especially with forced air gas heaters, have resulted in a wealth of information on (1) understanding responses of insect species and life stages to heat, (2) heat distribution within a treated area, and (3) techniques necessary for gauging effectiveness of commercial heat treatments. Insect responses vary with the temperature, among species, and within a species among life stages. Air movement and strategic placement of fans are important for eliminating cool spots.Keywords: Heat, Forced air, Flour mills, Methyl bromide alternativ

    Equilibrium Moisture Content of Kabuli, Chickpea, Black Sesame, and White Sesame Seeds

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    Sesame and chickpea are important crops in Ethiopia because both are major export crops that generate much revenue for both small farmers and the country as a whole. However, there is a lack of information about the fundamental equilibrium moisture content (EMC) relationships among these crops, which would help facilitate better monitoring and storage. Therefore, EMC adsorption and desorption prediction models based on temperature (T) and relative humidity (RH) were developed for the modified Chung-Pfost and modified Henderson models for Kabuli chickpea (KC), black sesame (BS), and white sesame (WS) seeds. The samples for conducting the adsorption and desorption tests were conditioned to various moisture content (MC) levels for the EMC test models. The samples (~500 g) were placed in multiple sealed enclosures equipped with T and RH sensors, which were placed in an environmental chamber where they were exposed to three temperatures (15°C, 25°C, and 35°C). The MCdb ranges used for model development for adsorption and desorption were, respectively, 11.6% to 19.5% and 8.9% to 16.9% for KC samples, 5.0% to 8.7% and 4.3% to 6.9% for BS, and 4.2% to 8.7% and 3.5% to 7.6% for WS. Nonlinear regression was used to determine the model coefficients for the modified Henderson and modified Chung-Pfost equations. The prediction statistics for the adsorption and desorption models yielded an SEE of, respectively, 0.53% and 0.68% MCdb for KC, 0.23% and 0.13% for BS, and 0.28% and 0.25% for WS. The model coefficients obtained in this study will be used in a moisture meter based on EMC measurement, which is currently being used as part of a USAID postharvest project in various African and Asian countries. These EMC models may also be important for other grain operations, which include harvesting, drying, storage, conditioning, and processing

    Fabrication and Analysis of Amorphous Silicon TFT

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    The display technology and large area electronics got momentum with the introduction of TFT devices. TFTs can be made using different semiconducting materials or organic conducting materials as the active layer. Each one of them differ in their performance depending on the material used for the active layer. In this paper, fabrication of amorphous silicon TFT using PECVD is carried out. Simulation of the a-Si: H TFT is also carried out with the dimensions similar to that of the masks used for the fabrication. The Id-Vd plot for both the simulation and fabrication is obtained and studied

    (2E)-1-(4-Methyl­phen­yl)-3-(2,3,5-trichloro­phen­yl)prop-2-en-1-one

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    In the title mol­ecule, C16H11Cl3O, the dihedral angle between the two benzene rings is 33.2 (1)°. The crystal packing is stabilized by C—H⋯O hydrogen bonds

    Electrical and Magnetotransport Properties of Canted Antiferromagnet Dyâ‚…Siâ‚‚Geâ‚‚

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    Summary form only given. Since the giant magnetocaloric effect is encountered in a ferromagnetic Gd5Si2Ge2 alloy near room temperature it is considered as a suitable material for magnetic refrigerator applications. Also a commensurate structural transition occurs at the magnetic transition temperature and there is a good correlation between the crystal structure and magnetic properties. Such observations have triggered numerous experimental studies on similar rare earth alloys and compounds. We have synthesized its Dy- analogue, namely, Dy5Si2Ge2 and have characterized it by means of room temperature X-ray diffraction, ac magnetic susceptibility (15 K - 300 K), electrical resistivity (at zero field and at 6 T), thermoelectric power (15 K - 300 K) and neutron diffraction (at 300 K and 9.2 K) experiments

    Alteration of Proteins and Pigments Influence the Function of Photosystem I under Iron Deficiency from Chlamydomonas reinhardtii

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    BACKGROUND: Iron is an essential micronutrient for all organisms because it is a component of enzyme cofactors that catalyze redox reactions in fundamental metabolic processes. Even though iron is abundant on earth, it is often present in the insoluble ferric [Fe (III)] state, leaving many surface environments Fe-limited. The haploid green alga Chlamydomonas reinhardtii is used as a model organism for studying eukaryotic photosynthesis. This study explores structural and functional changes in PSI-LHCI supercomplexes under Fe deficiency as the eukaryotic photosynthetic apparatus adapts to Fe deficiency. RESULTS: 77K emission spectra and sucrose density gradient data show that PSI and LHCI subunits are affected under iron deficiency conditions. The visible circular dichroism (CD) spectra associated with strongly-coupled chlorophyll dimers increases in intensity. The change in CD signals of pigments originates from the modification of interactions between pigment molecules. Evidence from sucrose gradients and non-denaturing (green) gels indicates that PSI-LHCI levels were reduced after cells were grown for 72 h in Fe-deficient medium. Ultrafast fluorescence spectroscopy suggests that red-shifted pigments in the PSI-LHCI antenna were lost during Fe stress. Further, denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI subunits PsaC and PsaD decreased, while PsaE was completely absent after Fe stress. The light harvesting complexes were also susceptible to iron deficiency, with Lhca1 and Lhca9 showing the most dramatic decreases. These changes in the number and composition of PSI-LHCI supercomplexes may be caused by reactive oxygen species, which increase under Fe deficiency conditions. CONCLUSIONS: Fe deficiency induces rapid reduction of the levels of photosynthetic pigments due to a decrease in chlorophyll synthesis. Chlorophyll is important not only as a light-harvesting pigment, but also has a structural role, particularly in the pigment-rich LHCI subunits. The reduced level of chlorophyll molecules inhibits the formation of large PSI-LHCI supercomplexes, further decreasing the photosynthetic efficiency

    Farmer participatory varietal selection in groundnut – A success story in Anantapur, Andhra Pradesh, India

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    Farmer participatory varietal selection trials in Anantapur, Andhra Pradesh, India identified ICGV 91114 as the most productive groundnut cultivar. This cultivar was adopted for large-scale production, giving higher pod and haulm yields and comparable shelling outturn compared with the control cultivar TMV 2
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