677 research outputs found

    Characterisation and Liberation of Graphite Schist

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    This paper deals with the characterisation and liberation studies of graphite schist from Shivaganga, Tamilnadu. The graphite flakes are interbanded with quartz and calcite. Secondary calcite veins often traverses graphite flakes and quartz grains. Based on grain counting, frequency curves , comminution followed by flotation tests , the liberation size of graphite is estimated between 150to 90 microns. Therougher concentrate achieved at d&, passing of 145 micron size product contain 35 % FC with 99% recovery.The SFM study reveals the presence of minute inclusions of calcite and quartz within graphite flakes

    Studies on genetic variability and relationship of bael (Aegle marmelos (L) Correa) using morphological and molecular markers

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    Bael (Aegle marmelos (L) Correa) is an important underutilized fruit crop of India. A total of 25 bael trees were selected from 356 bael trees of Sakharayapattana in Chikkamagalur district, Karnataka, India based on the fruit morphological traits (fruit weight, pulp weight, skull thickness, seed weight per fruit, No. of seeds per fruit, No. of locules per fruit, No. of seeds per locule, pulp wt. : seed wt.). These 25 trees were evaluated for phenotypic and genotypic variations using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeats (ISSR) markers. RAPD and ISSR markers showed significant polymorphism among the trees. Jaccard’s genetic similarity value of RAPD and ISSR was found in the range of 0.00–0.95 and 0.06–0.56, respectively suggesting a moderate level of genetic diversity. The present study revealed that molecular markers can be successfully utilized for determining genetic diversity and relationship of bael trees for further varietal improvement

    Malignant transformation of a recurrent giant cell tumor of bone with lung metastasis: a case report

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    Giant cell tumors (GCT) are benign tumors with potential for aggressive behaviour and capacity to metastasize. It is a locally destructive tumor that occurs predominantly in long bones of adolescents and young adults in the epiphysis. Although rarely lethal, benign bone tumors may be associated with a substantial disturbance of the local bony architecture that can be particularly troublesome in peri-articular locations. It is characterized by a proliferation of mononuclear stromal cells and the presence of many multi-nucleated giant cells with homogenous distribution. There are varying surgical techniques ranging from intra-lesional curettage to wide resection. As most giant cell tumors are benign and are located near a joint in young adults, several authors favour an intralesional approach that preserves anatomy of bone. Although GCT is classified as a benign lesion, few patients develop progressive lung metastases with poor outcomes. Malignant transformation without radiotherapy exposure, is an uncommon event, occurring in less than 1% of giant cell tumors of bone. Here we reported a case of recurrent GCT of tibia that at the time of final recurrence was found to have undergone malignant transformation over a period of 6 years following several limb salvaging procedures. Concurrent metastases were found in the lung, but these were non-transformed GCT following which the patient has undergone above knee amputation

    Energy Audit on a Secondary Distribution System and Measures to Improve its Performance- A Case Study

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    This paper presents the energy audit work carried out in low tension(LT) distribution network and various alternative proposals have been examined for the improvement of performance of the LT network. The network is simulated for a peak load using Mipower package to segregate technical and commercial losses. The various alternative proposals examined are relocating of DTC, addition of DTC, providing express line and reconductoring. The present worth analysis is also carried out for each alternative proposal

    The discretised harmonic oscillator: Mathieu functions and a new class of generalised Hermite polynomials

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    We present a general, asymptotical solution for the discretised harmonic oscillator. The corresponding Schr\"odinger equation is canonically conjugate to the Mathieu differential equation, the Schr\"odinger equation of the quantum pendulum. Thus, in addition to giving an explicit solution for the Hamiltonian of an isolated Josephon junction or a superconducting single-electron transistor (SSET), we obtain an asymptotical representation of Mathieu functions. We solve the discretised harmonic oscillator by transforming the infinite-dimensional matrix-eigenvalue problem into an infinite set of algebraic equations which are later shown to be satisfied by the obtained solution. The proposed ansatz defines a new class of generalised Hermite polynomials which are explicit functions of the coupling parameter and tend to ordinary Hermite polynomials in the limit of vanishing coupling constant. The polynomials become orthogonal as parts of the eigenvectors of a Hermitian matrix and, consequently, the exponential part of the solution can not be excluded. We have conjectured the general structure of the solution, both with respect to the quantum number and the order of the expansion. An explicit proof is given for the three leading orders of the asymptotical solution and we sketch a proof for the asymptotical convergence of eigenvectors with respect to norm. From a more practical point of view, we can estimate the required effort for improving the known solution and the accuracy of the eigenvectors. The applied method can be generalised in order to accommodate several variables.Comment: 18 pages, ReVTeX, the final version with rather general expression

    Effects of residual stresses on interlaminar radial strength of Glass-Epoxy L-bend composite laminates

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    The built-in heterogeneity of the composite laminates has been exploited to tailor the stiffness and strength requirements of modern structures to meet the specific functional demands. However, the non-homogeneity in these composites is the root cause for most of their failures. One of the undesirable consequences of the inherited heterogeneity is the development of cure-induced stresses during composite manufacturing. This work aims to investigate the influence of process-induced stresses on interlaminar radial strength in curved composite laminates. Glass-Epoxy (GE) laminates of two different thicknesses were prepared by hand lamination technique using V-shaped tooling and cured under room temperature. The state of residual stresses in GE laminates is varied by post-curing these laminates at different temperatures. Curved bending strength (CBS) and corresponding interlaminar radial stress for delamination of L-bend laminates were evaluated experimentally using four points bending test. The residual stress profile in each GE laminate is experimentally characterized by employing the Slitting method. The results indicate that the residual stresses have a negligible effect on the critical stress for initial delamination in GE laminates. But, the critical stress for delamination was found to be independent of the laminate thickness and increased with higher curing temperatures. The delaminated surfaces of L-bend laminates were studied using a scanning electronic microscope (SEM). The enhancement in the critical stress due to post-curing can be attributed to the improved fiber-matrix interfacial bonding with higher curing temperature

    Fabrication, Mechanical and Wear Properties of Aluminum (Al6061)-Silicon Carbide-Graphite Hybrid Metal Matrix Composites

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    In recent times, the use of aluminum alloy-based Hybrid Metal Matrix Composites (HMMCs) is being increased in aerospace and automotive applications. HMMCs compensate for the low desirable properties of each filler used. However, the mechanical properties of HMMCs are not well understood. In particular, microstructural investigations and wear optimization studies of HMMCs are not clear. Therefore, further studies are required. The present study is aimed at fabricating and mechanical and wear characterizing and microstructure investigating of Silicon Carbide (SiC) and Graphite (Gr) added in Aluminum (Al) alloy Al6061 HMMCs. The addition of SiC particles was in the range from 0 to 9 weight percentage (wt.%) in steps of 3, along with the addition of 1 wt.% Gr in powder form. The presence of alloying elements in the Al6061 alloy was identified using the Energy Dispersive X-Ray Analysis (EDX). The dispersion of SiC and Gr particles in the alloy was investigated using metallurgical microscope and Scanning Electron Microscopy (SEM). The gain in strength can be attributed to the growth in dislocation density. The nature of fracture was quasi-cleavage. The microstructure examination reveals the uniform dispersion of the reinforcement. Density, hardness, and Ultimate Tensile Strength values observed to be increased with increased contents of SiC reinforcement. Besides, wear studies were performed in dry sliding conditions. Optimization studies were performed to investigate the effect of parameters that affecting the wear. The sliding wear resistance was noticed to be improved concerning higher amounts of reinforcement leading to a decrease in delamination and adhesive wear. The predicted values for the wear rate have also been compared with the experimental results and good correlation is obtained

    T-cell rich B-cell lymphoma of the breast: A rare case report with emphasis on the role of immunohistochemistry in the diagnosis

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    Primary breast lymphoma is one of the rare tumors that commonly presents as a lump with <0.5% incidence rate. It may be misdiagnosed as poorly differentiated carcinoma on routine fine-needle aspiration cytology. With appropriate treatment, this breast malignancy has a relatively better prognosis. Here, we report the case of a mammary T-cell rich B-cell non-Hodgkin lymphoma in a pre-menopausal woman diagnosed by biopsy and later confirmed by immunohistochemistry

    Proof of concept: Partner-Assisted Interpersonal Psychotherapy for perinatal depression

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    Although poor partner support is a key risk factor for depression in pregnant and postpartum women, partners are not generally involved in treatment beyond psychoeducation. The aim of this "proof of concept" study was to test safety, acceptability, and feasibility of Partner-Assisted Interpersonal Psychotherapy (PA-IPT), an intervention that includes the partner as an active participant throughout treatment. Women more than 12 weeks estimated gestational age and less than 12 weeks postpartum were invited to participate if they fulfilled DSM-IV criteria for Major Depressive Disorder and reported moderate symptom severity (HAM-D17 ≥16). The open trial included eight acute-phase sessions and a 6-week follow-up assessment. Ten couples completed the acute phase treatment and nine presented for a 6-week follow-up assessment. There were no study-related adverse events, and no women had symptomatic worsening from intake to Session Eight. All partners attended all sessions, no couples dropped out of treatment, and all reported positive treatment satisfaction at the conclusion of the study. Nine of ten women (90 %) met the criteria for clinical response (HAM-D17=9) at the conclusion of acute phase treatment, and eight of the nine (89 %) presenting at a 6-week follow-up assessment met criteria for symptomatic recovery. Incorporating partners in the treatment of major depressive disorders during the perinatal period is safe, acceptable, and feasible, but needs further testing in a larger population to evaluate efficacy
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