685 research outputs found

    Paramagnetic magnetization signals and curious metastable behaviour in field-cooled magnetization of a single crystal of superconductor 2H-NbSe2

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    We present here some newer characteristics pertaining to paramagnetic Meissner effect like response in a single crystal of the low Tc superconducting compound 2H-NbSe2 via a detailed study of effects of perturbation on the field-cooled magnetization response. In the temperature range, where an anomalous paramagnetic magnetization occurs, the field-cooled magnetization response is found to be highly metastable: it displays a curious tendency to switch randomly from a given paramagnetic value to a diamagnetic or to a different paramagnetic value, when the system is perturbed by an impulse of an externally applied ac field. The new facets revealed in a single crystal of 2H-NbSe2 surprisingly bear a marked resemblance with the characteristics of magnetization behaviour anticipated for the giant vortex states with multiple flux quanta predicted to occur in mesoscopic-sized superconducting specimen and possible transitions amongst such states.Comment: 12 pages, 9 figures, submitted to Journal of Physics: Condensed Matte

    Drug utilization 90%: an innovative method in assessing quality of drug prescription with specific reference to non-steroidal anti-inflammatory drugs prescription

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    Background: DU90% is useful tool for assessing drug prescribing pattern. In this, drugs constituting 90% of the prescription volume are identified. Size of the DU90% segment helps us to assess rational prescribing. Large number of drugs in the DU90% segment indicates less rational prescribing, whereas small number suggests more rational prescribing.Methods: Study was carried out in orthopaedic out-patient department (OPD) for a period of three months. Only OPD based NSAID containing prescriptions were included. Data was analyzed based on demographic parameters, prescription indices, fixed dose combinations (FDC) and co-prescription of gastro-protective agents (GPA). DU90% was calculated based on defined daily dose (DDD) with their respective value in Anatomical Therapeutic Chemical (ATC) classification code. Defined daily dose is calculated as DDD/1000/day.Results: Diclofenac (38%) was the commonest NSAID prescribed. Diclofenac +chymotrypsin (25%) was the commonest FDC prescribed. Piroxicam (19%) was the commonest NSAID prescribed in monotherapy form.  Co-prescription of GPA was high (96%). 5 of the 7 prescribed NSAIDs constitute to DU90% segment.Conclusions: Preferential cyclooxygenase-2 (COX-2) inhibitor NSAIDs were more preferred. Number of prescribed NSAIDs constituting to DU90% is more, thus prescription pattern needs further rationalization. Further large scale study is required to bring out more details about NSAID prescription pattern and its rational use

    A PROSPECTIVE STUDY ON EFFECT OF FLUOXETINE ON PRIMARY HEMOSTASIS OF PATIENTS HAVING MAJOR DEPRESSIVE DISORDER

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    Objectives: The objectives of the study were to study the effect of fluoxetine on bleeding time, clotting time and platelet count of depressed patients. Methods: Patients diagnosed with major depressive disorder were included in the study to fulfill a sample size of 60. Before starting the treatment with fluoxetine, laboratory tests were done which included bleeding time, clotting time, and platelet count. Patients were requested to return for follow-up after 4 weeks of treatment and the laboratory tests were repeated. All the study end point analysis was analyzed based on per-protocol population. Continuous variables were expressed as mean and standard deviations, paired t-test was used for within group comparison and unpaired t-test was used for between group comparisons. p<0.05 was considered to be significant. For categorical variable, frequency and percentage were calculated. For continuous variable, that is, bleeding time, clotting time, and platelet count, mean and standard deviation were calculated. Results: At the end of 4 weeks, it was observed that there was a significant increase in bleeding time from 1.35±0.08 min to 1.46±0.08 min**. Similarly, there was a significant increase in clotting time from 3.30±0.15 min to 3.38±0.15 min**. It was also observed that there was a significant decrease in platelet count from 3.07±0.67 lakh cells/cu mm to 2.86±0.63 lakh cells/cu mm**. Conclusion: Fluoxetine has shown to increase bleeding time, clotting time, and decrease platelet count. Hence, fluoxetine induced risk of bleeding and its cardio protective action has to be considered while individualizing therapy in management of depression

    Good Statistical Practice: A Key To Effective and Safe Drug Product

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    In the pharmaceutical R&D the evaluation procedures play a key role in developing a potent graded product focusing on the various technical advancements it’s easy to overcome hazards.Emphasis is placed on the product’s development to reach specifications of USFDA ,US Pharmacopeia, National Formulary for achieving standards that provide insight on evaluation techniques of drug formulation.Adoption of guidance’s and guidelines cited will strive for achieving good laboratory practice(GLP) good clinical practice(GCP) and good manufacturing practice(cGMP).Embracing  statistical approach provides accuracy and reliability of results

    Femtosecond to nanosecond excited states dynamics of novel Corroles

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    We report a comprehensive photphysical investigation of some corrole molecules employing fs/nanosecond (ns) transient-absorption and time-resolved photoluminescence spectroscopy with support from the time-dependent density-functional theory calculations to understand their intramolecular charge transfer and polaron-absorption character

    Jacobi Crossover Ensembles of Random Matrices and Statistics of Transmission Eigenvalues

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    We study the transition in conductance properties of chaotic mesoscopic cavities as time-reversal symmetry is broken. We consider the Brownian motion model for transmission eigenvalues for both types of transitions, viz., orthogonal-unitary and symplectic-unitary crossovers depending on the presence or absence of spin-rotation symmetry of the electron. In both cases the crossover is governed by a Brownian motion parameter {\tau}, which measures the extent of time-reversal symmetry breaking. It is shown that the results obtained correspond to the Jacobi crossover ensembles of random matrices. We derive the level density and the correlation functions of higher orders for the transmission eigenvalues. We also obtain the exact expressions for the average conductance, average shot-noise power and variance of conductance, as functions of {\tau}, for arbitrary number of modes (channels) in the two leads connected to the cavity. Moreover, we give the asymptotic result for the variance of shot-noise power for both the crossovers, the exact results being too long. In the {\tau} \rightarrow 0 and {\tau} \rightarrow \infty limits the known results for the orthogonal (or symplectic) and unitary ensembles are reproduced. In the weak time-reversal symmetry breaking regime our results are shown to be in agreement with the semiclassical predictions.Comment: 24 pages, 5 figure

    Technical Paper Session I-B - CIGSeS and CIGS2 Thin Film Solar Cells on Flexible Foils for Space Power

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    The objective of the research is to develop flexible, lightweight, radiationresistant, high-specific-power, highly efficient CuIn1-xGaxSe2-ySy (CIGSeS) and CuIn1- xGaxS2 (CIGS2) thin-film solar cells for space electric power. The near optimum bandgap, potential for higher specific power, and superior radiation resistance make this technology an ideal candidate for space electric power. The superior radiation resistance of CIGSeS thin-film solar cells relative to the conventional silicon and gallium arsenide single-crystal cells in the space radiation environment would extend mission lifetimes substantially. The conventional rigid Si and GaAs cells must be folded in an accordion style for deployment space. This can cause problems of opening up and folding of the solar array as has happened recently with the International Space Station. On the other hand, the flexible solar cells and modules can be packaged and rolled out more easily. The stainless steel and titanium foil substrate materials are capable of withstanding high temperatures required for preparing good quality CIGSeS absorber layer. They also do not sag easily and hence do not require rigidizing as is the case with plastic sheet substrates. The CIGSeS absorber film is prepared by selenization/sulfurization of DC magnetron sputter-deposited CuGa, In metallic precursors on 10 cm x 10 cm metallic foil substrate coated with molybdenum back contact layer. CdS heterojunction partner is deposited by chemical bath deposition. Transparent and conducting bilayer of intrinsic ZnO and aluminum doped ZnO:Al is deposited by RF magnetron sputtering. Cells are completed by depositing Ni/Al front contact fingers by thermal evaporation. The sputtering technique utilized in the preparation of solar cells provides an added advantage of facilitating easy scale-up of the laboratory size cells for economic large-area manufacture by the roll-to-roll process. Chemical composition, crystallographic structure and morphology of CIGSeS thin films are analyzed by energy dispersive spectroscopy, Auger electron spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The photovoltaic properties of completed cells are studied by measurement of current-voltage characteristics and quantum efficiency. Best efficiencies of 10.4% under AM 1.5 conditions and 8.84% under AM 0 conditions were achieved on small-area CIGS2 thin-film solar cells

    Conductance Distributions in Chaotic Mesoscopic Cavities

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    We consider the conductance distributions in chaotic mesoscopic cavities for all three invariant classes of random matrices for the arbitrary number of channels N1, N2 in the connecting leads. We show that the Laplace transforms of the distributions can be expressed in terms of determinants in the unitary case and Pfaffians in the orthogonal and symplectic cases. The inverse Laplace transforms then give the exact distributions. This formalism is particularly useful for small values of N = min (N1, N2), and thus is of direct experimental relevance. We also obtain the conductance distributions for orthogonal-unitary and symplectic-unitary crossover ensembles.Comment: 19 pages, 4 figure
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