108 research outputs found

    Crushing and Grinding : Practice and Problems in Kalyadi Copper Mine Concentrator

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    At Kalyadi concentrator plant the ROM ore is required to be reduced to 70% - 200 mesh size for liberation of valuable mineral. The metallic minerals that are mainly present in the ore are chalcopyrite, pyrite, magnetite and pyrrhotite the latter two being of minor occurance within quartzite. These minerals occur as disseminations, specks, particles, thin veinlets and concentrations. Ore is highly abrasive in nature with specfic gravity of 2.9. Ore grade varies from 0.5 to 0.8% Cu. giving an average grade of 0. 65% Cu

    Density, dielectric and X-ray studies of Smectic A-Smectic A transitions

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    We report here the results of detailed density, dielectric and X-ray studies on three systems exhibiting different types of Smectic A-Smectic A transitions. It is found that although the layer spacing shows marked changes at the transitions, the corresponding density changes are extremely small. In every case studied, the dielectric anisotropy shows a pronounced decrease on going over to the lower temperature smectic A phase. This decrease can be correlated with the structural changes

    Ion beam-induced luminescence and photoluminescence of 100 MeV Si8+ ion irradiated kyanite single crystals

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    lonoluminescence (IL) of kyanite single crystals during 100 MeV Si8+ ion irradiation has been studied in the fluence range 1.87-7.50 x 10(11) ions/cm(2). Photoluminescence (PL) of similar dimensional crystals was recorded with same ions and energy in the fluence range 1 x 10(11) -5 x 10(13) ions/cm(2) with an excitation of 442 non He-Cd laser beam. A sharp IL and broad PL peaks at similar to 689 and 706 run were recorded. This is attributed to luminescence centers activated by Fe2+ and Fe3+ ions. It is observed that up to a given fluence, the IL and PL peak intensities increase with increase of Si8+ ion fluence. The stability of the chemical species was Studied on with and without irradiated samples by means of FT-IR spectroscopy. The results confirm that the O-Si-H type bonds covering on the surface of the sample. This layer might be acting as a protective layer and there by reducing the number of non-radiative recombination centers. (c) 2008 Elsevier Ltd. All rights reserved

    STATIC AND TRANSIENT ANALYSIS OF COMPOSITE LEAF SPRING

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    Leaf springs are mainly used in suspension systems to absorb shock loads in automobiles like light motor vehicles, heavy duty trucks and in rail systems. It carries lateral loads, brake torque, driving torque in addition to shock absorbing. This work deals with finding a suitable composite material that can be a replacement for conventional steel leaf spring. The stress and displacements have been calculated using theoretically as well as using ANSYS for steel leaf spring and composite leaf spring. The model is designed in CREO software for the vehicle Mahindra “Model - commander 650 di”. Analysis is done in ANSYS software for different materials (Steel, Kevlar and E-Glass Epoxy). The static analysis is done to determine the deformation, stress and strain for different materials. A comparative study has been made between steel and composite leaf spring with respect to strength and weight. Transient analysis is done to determine the deformation, stress with respect to time for different materials. Fatigue analysis is done to determine the fatigue life for steel, E glass epoxy and Kevlar leaf spring

    Optineurin Is Required for CYLD-Dependent Inhibition of TNFα-Induced NF-κB Activation

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    The nuclear factor kappa B (NF-κB) regulates genes that function in diverse cellular processes like inflammation, immunity and cell survival. The activation of NF-κB is tightly controlled and the deubiquitinase CYLD has emerged as a key negative regulator of NF-κB signalling. Optineurin, mutated in certain glaucomas and amyotrophic lateral sclerosis, is also a negative regulator of NF-κB activation. It competes with NEMO (NF-κB essential modulator) for binding to ubiquitinated RIP (receptor interacting protein) to prevent NF-κB activation. Recently we identified CYLD as optineurin-interacting protein. Here we have analysed the functional significance of interaction of optineurin with CYLD. Our results show that a glaucoma-associated mutant of optineurin, H486R, is altered in its interaction with CYLD. Unlike wild-type optineurin, the H486R mutant did not inhibit tumour necrosis factor α (TNFα)-induced NF-κB activation. CYLD mediated inhibition of TNFα-induced NF-κB activation was abrogated by expression of the H486R mutant. Upon knockdown of optineurin, CYLD was unable to inhibit TNFα-induced NF-κB activation and showed drastically reduced interaction with ubiquitinated RIP. The level of ubiquitinated RIP was increased in optineurin knockdown cells. Deubiquitination of RIP by over-expressed CYLD was abrogated in optineurin knockdown cells. These results suggest that optineurin regulates NF-κB activation by mediating interaction of CYLD with ubiquitinated RIP thus facilitating deubiquitination of RIP
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