34 research outputs found

    Transformation of non-standard nuclear I&C logic drawings to formal verification models

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    Generalized principal eigenvalues on Rd\mathbb{R}^d of second order elliptic operators with rough nonlocal kernels

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    We study the generalized eigenvalue problem on the whole space for a class of integro-differential elliptic operators. The nonlocal operator is over a finite measure, but this has no particular structure. Some of our results even hold for singular kernels. The first part of the paper presents results concerning the existence of a principal eigenfunction. Then we present various necessary and/or sufficient conditions for the maximum principle to hold, and use these to characterize the simplicity of the principal eigenvalue.Comment: 23 page

    A Simple Method to Determine the Dielectric Constant of Small-Sized Medium-Loss Samples at X-Band Frequencies

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    Abstract An analytical solution for the measurement of dielectric constant of relatively small-sized medium loss samples is formulated in TE 011 resonant mode rectangular cavity. Next a simple but ingenious technique based on cavity perturbation techniques in X-band frequencies is presented. The technique is established by using materials having known dielectric constants like p-type silicon. Finally, the technique was applied to study the dielectric constant of wax as a monomer and Ethylene Vinyl Acetate (EVA) as a polymer with carbon loading

    A water soluble Ni-Schiff base complex for homogeneous green catalytic C S cross-coupling reactions

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    Since the embarkation of C – S cross-coupling from aryl halides with thiols a handful of works have been contemplated in aqueous medium. Herein, we report an example of a water soluble Ni-Schiff base complex as the green catalyst for the synthesis of thioethers. We have synthesized a Ni-Schiff base complex [NiL(H2O)2 ](ClO4)2 using N 4 -donor Schiff base ligand (1,3-bis(((E)-pyridin-2-ylmethylene)amino)propan-2-ol) and characterized by single crystal X-ray diffraction (SC-XRD) study along with different spectral analyses. The complex is mono-nuclear and cationic in nature having two perchlorate anions. Two water molecules remain coordinated with the Ni(II)-centre. The hydrogen bonding interaction through coordinated water and perchlorate anions connect the monomeric units to form 2D supramolecular structure. Based on its aqueous solubility, the complex has been used for the catalytic C – S cross-coupling reaction between aryl iodide and aryl or alkyl thiols using TBAB at 60 ◦ C in aqueous media (yield 92%). At room temperature, an isolated yield of 57% can be achieved. This environmentally benign protocol is paramount in view of the environmental sustainability

    IN-VITRO CYTOTOXICITY ANALYSIS OF TAMOXIFEN CITRATE LOADED CROSS-LINKED GUAR GUM NANOPARTICLES ON JURKAT (HUMAN T-CELL LEUKEMIA) CELL LINE

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    The present investigation was aimed to study the antiproliferative action of tamoxifen citrate (TMX), a non steroidal antiestrogen, on a human T-cell leukemia cell line, Jurkat, as free drug and TMX loaded guar gum nanoparticles. For this we developed a new formulation containing chemically cross-linked guar gum nanoparticles (GG NPs) loaded with tamoxifen citrate (TMX). Single step (oil in water) emulsion and in-situ polymer cross-linking technique was employed to prepare spherical and smooth surfaced nanoparticles in the size range of 200-300nm. Nanoparticle size and shape was confirmed from observation in transmission electron microscope (TEM) analysis. Cytotoxicity on Jurkat (human T-cell leukemia) cell lines as determined by cell growth inhibition after 48 hrs of incubation indicated that tamoxifen citrate loaded guar gum nanoparticles were as efficient as the free drug when applied to the cancer line. However, the crosslinked guar gum nanoparticles loaded with tamoxifen citrate exhibited sustained release of the drug and delayed apoptosis over a long period of time making it suitable for cancer treatment. Keywords: Nanoparticles, guar gum, tamoxifen citrate, Jurkat (human T-cell leukemia) cell line, cytotoxicity, cell death, WST-1 assay

    Characterization of the Occult Hepatitis B Virus Variants Circulating among the Blood Donors from Eastern India

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    A previous study from West Bengal documented very high rate of occult HBV infection (OBI) among the HBsAg negative blood donors. This study was aimed to characterize the OBI strains circulating among the blood donors and to estimate the risk associated with the prevailing viral variants/mutants. Blood samples from 2195 voluntary blood donors were included in the study. HBsAg, HBeAg, anti-HBc, and anti-HBs statuses of the samples were done by ELISA based detection. PCR amplification and sequencing were done to determine HBV genotypes, basal core promoter (BCP), and precore (Pre-C) mutations. Among the study samples, 268 were anti-HBc positive/HBsAg negative, among which 65 (24.25%) were HBV DNA positive. Phylogenetic analysis revealed the presence of HBV/D (87.23%), HBV/A (8.51%), and HBV/C (4.26%) (P<0.0001). HBV/D3 (65.85%) was the significantly prevalent subgenotype over HBV/D2 (26.83%) and HBV/D1 (7.31%) (P=0.0003). Considerable prevalence of differential BCP (1752C, 1753C, 1762T/1764A, 1753C+1762T/1764A, 1773C, and 1814C) and reverse transcriptase (rt) gene (rtI91L, rtL93P, rtS106C, rtR110G, rtN118T, rtS119T, rtY126H, rtG127W/R, rtC136R, and rtY158H) mutations was identified. Association of specific HBV subgenotypes with OBI was interesting and needs further study. Clinically relevant mutations were prevalent among the OBI strains which are of serious concern

    Characterization of the Occult Hepatitis B Virus Variants Circulating among the Blood Donors from Eastern India

    Get PDF
    A previous study from West Bengal documented very high rate of occult HBV infection (OBI) among the HBsAg negative blood donors. This study was aimed to characterize the OBI strains circulating among the blood donors and to estimate the risk associated with the prevailing viral variants/mutants. Blood samples from 2195 voluntary blood donors were included in the study. HBsAg, HBeAg, anti-HBc, and anti-HBs statuses of the samples were done by ELISA based detection. PCR amplification and sequencing were done to determine HBV genotypes, basal core promoter (BCP), and precore (Pre-C) mutations. Among the study samples, 268 were anti-HBc positive/HBsAg negative, among which 65 (24.25%) were HBV DNA positive. Phylogenetic analysis revealed the presence of HBV/D (87.23%), HBV/A (8.51%), and HBV/C (4.26%) ( &lt; 0.0001). HBV/D3 (65.85%) was the significantly prevalent subgenotype over HBV/D2 (26.83%) and HBV/D1 (7.31%) ( = 0.0003). Considerable prevalence of differential BCP (1752C, 1753C, 1762T/1764A, 1753C+1762T/1764A, 1773C, and 1814C) and reverse transcriptase (rt) gene (rtI91L, rtL93P, rtS106C, rtR110G, rtN118T, rtS119T, rtY126H, rtG127W/R, rtC136R, and rtY158H) mutations was identified. Association of specific HBV subgenotypes with OBI was interesting and needs further study. Clinically relevant mutations were prevalent among the OBI strains which are of serious concern

    Model-to-Model Transformation Of Nuclear Industry I&C Logic To Assist Model Checking

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    The demand for electricity has increased proportionately with massive urbanisation and in-dustrialisation. Nuclear energy is a strong candidate which can be one of the solutions to ca-ter to this massive demand for energy. Nuclear resources have the benefit of enormous ener-gy density, low carbon footprint, cheap operating cost and production reliability. Even though it is deemed as a dependable and economically viable option, it is limited by safety concerns, unfortunate accidents can cause monumental and long-lasting consequences. On the other hand, if critically examined, thoroughly tested and flawlessly implemented, the decision-makers can opt for nuclear source. Thus utilising nuclear resources will call for an error-proof instrumentation and control system to observe and ensure safe operation. Model verification plays a vital role in critical analysis of I & C system, it checks all the possibilities the system may reach, and thus provide a model to develop an I&C safety system. An industrial operation may suffer from unknown component failure and design error, but its safety-critical system must be able to strictly prohibit these undesired events in the system before causing any major accident. “Model Checking” is a mathematical deterministic tool for logic design verification, which has been proven to be effective for detecting design errors in the system. Granted that, Instrumentation and control system starts with logic design at the preliminary phase, a model checking tool can efficiently identify design faults by exhaustive analysis. NuSMV is such a tool, which provides simpler syntax, that can represent the system as logical states with simple data structures. Analysts write SMV files to represent the system available as proprietary non-standard machine-readable diagrams. This thesis proposes an automation step towards diagram import in a verification tool and implements an intermediate data representation. This thesis provides a perception of various technologies relevant to broader authentication process of a safety system covering from design to verification tools. The state-of-the-art model-checking practice is discussed briefly. Subsequently, a number of logical instrumenta-tion and control diagrams, drawn in Microsoft VISIO tool, are analysed and processed to au-tomatically create an intermediate component network consisting of Function Block elements. A significant effort is spent to partially generate NuSMV code from the retrieved component data to assist the model checking of the system. Finally, the thesis is concluded with a synop-sis of the work done and future development scope
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