1,611 research outputs found

    A detailed analysis of structure growth in f(R)f(R) theories of gravity

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    We investigate the connection between dark energy and fourth order gravity by analyzing the behavior of scalar perturbations around a Friedmann-Robertson-Walker background. The evolution equations for scalar perturbation are derived using the covariant and gauge invariant approach and applied to two widely studied f(R)f(R) gravity models. The structure of the general fourth order perturbation equations and the analysis of scalar perturbations lead to the discovery of a characteristic signature of fourth order gravity in the matter power spectrum, the details of which have not seen before in other works in this area. This could provide a crucial test for fourth order gravity on cosmological scales.Comment: 27 pages and 35 figure

    "Primary" aggressive chondroblastoma of the humerus: a case report

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    BACKGROUND: Chondroblastomas are rare epiphyseal bone tumors. Very few cases with extra-cortical aggressive soft tissue invasion or metastasis are reported. CASE PRESENTATION: We report a 28 year-old adult male who presented with a large swelling over the left shoulder region. Pre-operative imaging revealed a large tumor arising from upper end of humerus with extensive soft tissue involvement necessitating a fore-quarter amputation. Patient received adjuvant radiation. CONCLUSIONS: This patient is one of the largest chondroblastomas to be reported. Although chondroblastomas are typically benign, rarely they can be locally aggressive or metastatic. Early diagnosis and institution of proper primary therapy would prevent mutilating surgeries and recurrences

    Calculation of Electric and Magnetic Field under AC Transmission and Distribution Lines in Guwahati City

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    With the increasing population rate and industrial growth rate, the demand for power has escalated significantly. High Voltage AC transmission can be termed as one of the measures to quench this increasing energy demands. This paper evaluates the safety limits for electric and magnetic fields generated around the AC transmission and distribution lines at various voltage levels and configuration. Surface current density for an average height human being has also been calculated for safety precautions.Keywords: Safety limits, electric field, magnetic field, surface current density*Cite as: Manash Jyoti Baishya, Satyajit Bhuyan, N.K.Kishore, “Calculation of Electric and Magnetic Field under AC Transmission and Distribution Lines in Guwahati City†ADBU J.Engg.Tech., 1(2014) 0011406(5pp

    Power optimized programmable embedded controller

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    Now a days, power has become a primary consideration in hardware design, and is critical in computer systems especially for portable devices with high performance and more functionality. Clock-gating is the most common technique used for reducing processor's power. In this work clock gating technique is applied to optimize the power of fully programmable Embedded Controller (PEC) employing RISC architecture. The CPU designed supports i) smart instruction set, ii) I/O port, UART iii) on-chip clocking to provide a range of frequencies , iv) RISC as well as controller concepts. The whole design is captured using VHDL and is implemented on FPGA chip using Xilinx .The architecture and clock gating technique together is found to reduce the power consumption by 33.33% of total power consumed by this chip.Comment: 11 pages,11 figures,International Journal Publicatio

    A questionnaire based study to assess knowledge, attitude and practice of pharmacovigilance among exam going second year undergraduate medical students in a South Indian teaching hospital

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    Background: Pharmacovigilance not only helps in the early detection of adverse drug reactions (ADRs) but also facilitates the identification of both, risk factors and the underlying mechanism. To increase the reporting rate, it is essential to improve the knowledge, attitude, and practices (KAP) of healthcare professionals regarding ADR reporting and pharmacovigilance, especially during undergraduate and postgraduate education. The objective of this study was to assess the KAP about pharmacovigilance among exam-going second-year undergraduate medical students.Methods: A cross-sectional questionnaire-based study was conducted among 150 exam-going second-year undergraduate students from Mysore Medical College and Research Institute, Mysore from April 2022 to June 2022. A validated questionnaire consisting of 22 questions divided into 3 sections; knowledge, attitude, and practice was used. Statistical analysis of data was done using an MS excel spreadsheet.Results: Out of the 150 participants 133 had good knowledge about ADR and pharmacovigilance. Majority of the students agreed that reporting of ADRs is necessary (95.3%), mandatory (95.3%), and should be included in pharmacology practicals (94.7%). Only 29.3% of the students had witnessed an ADR and none of the participants had ever reported an ADR indicating poor practice among the undergraduate students.Conclusions: Students had good knowledge and positive attitude towards ADR reporting and pharmacovigilance. Practice regarding pharmacovigilance was found to be poor, indicating the need for training the undergraduate students in ADR reporting by including ADR recognition and reporting as a part of clinical posting curriculum

    Applicability of genetic algorithms to reconstruction of projected data from ultrasonic tomography

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    In this paper simulation studies of the ultrasound computerized tomography (CT) technique employing time of flight data is presented. An enhanced genetic algorithm based reconstruction technique is proposed that is capable of detecting multiple types of inclusions in the test specimen to be reconstructed. It is assumed that the physical properties of the inclusions are known a priori. The preliminary results of our algorithm for a simple configuration are found to be better than those reported with MART1. In addition to being able to identify inclusions of different materials, both the shape and location of the inclusions could be reconstructed using the proposed algorithm. The results are found to be consistent and satisfactory for a wide range of grid sizes and geometries of inclusion(s). Based on the regression analysis an empirical relation between the number of unknowns and the reconstruction time is found which enables one to predict the reconstruction time for higher resolutions
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