51 research outputs found

    Comparison between the effects of high sevoflurane concentration during induction of anasesthesia using vital capacity breath and tidal breathing techniques in adults

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    Introduction: The aims of this randomised study were to compare the induction characteristics of sevoflurane using vital capacity breath technique to that of tidal breathing technique in adults undergoing day-care surgery, and to compare patients’ acceptance of these two techniques. Methods: Sixty ASA I and II adult patient undergoing day-care surgery were randomly allocated to receive either the vital capacity breath or tidal breathing technique for induction of anaesthesia with 7.5% sevoflurane in nitrous oxide and oxygen. Haemodynamic changes, induction characteristics and patients acceptance were compared. Results: The mean time for induction was significantly faster with the vital capacity breath technique. There were no significant differences in haemodynamic changes and oxygenation during induction between these two groups. There was significant increase in incidence of excitatory movement in patient receiving the tidal breathing technique. Either technique was found to be acceptable by most of the patients studied. Conclusion: The vital capacity breath technique appears to be better tolerated with shorter onset time and less movement during induction of anaesthesia. As it is well accepted by the patients and has a stable haemodynamic profile, its use should be encouraged

    Design and implementation of solar power fed permanent magnet synchronous motor with improved DC-DC converter and power quality improvement using shunt active filter for reducing vibration in drive for industrial applications

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    The research work proposes, Design and implementation of Solar power fed permanent magnet synchronous motor using improved DC-DC Converter and modified p-q theory based shunt active filter for reducing vibrations in drive for Industrial Applications. The Proposed research consists of both buck and boost converter, linking dc voltage unit and works in discontinuous conduction for boosting the battery life time. The improved converter provides multiple output capability using B4-inverter which reduces the cost of a proposed system considerably. In addition, for the reduction of harmonics in three phase system modified p-q module is enhanced. Comparing with the existing module, modified p-q module act as a triggering module for inverter to reduce harmonics in three phase systems and vibration across the motor, moreover the structured circuit would result in reduction of total harmonic distortion (THD), torque ripples, compact power switches, DC source reckoning and reduced starting current. The simulation of buck boost converter is considered, and its performance parameters were analyzed for different operating conditions. Thus, for industrial applications, the bidirectional converter and inverter fed permanent magnet synchronous motor drive is employed with the reduction in vibration, which is more efficient than conventional method. Here both simulation and experimental setup has been employed with a satisfying closed loop performance

    Identification and Characterization of Genetic Determinants of Isoniazid and Rifampicin Resistance in Mycobacterium tuberculosis in Southern India

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    Abstract: Drug-resistant tuberculosis (TB), one of the leading causes of death worldwide, arises mainly from spontaneous mutations in the genome of Mycobacterium tuberculosis. There is an urgent need to understand the mechanisms by which the mutations confer resistance in order to identify new drug targets and to design new drugs. Previous studies have reported numerous mutations that confer resistance to anti-TB drugs, but there has been little systematic analysis to understand their genetic background and the potential impacts on the drug target stability and/or interactions. Here, we report the analysis of whole-genome sequence data for 98 clinical M. tuberculosis isolates from a city in southern India. The collection was screened for phenotypic resistance and sequenced to mine the genetic mutations conferring resistance to isoniazid and rifampicin. The most frequent mutation among isoniazid and rifampicin isolates was S315T in katG and S450L in rpoB respectively. The impacts of mutations on protein stability, protein-protein interactions and protein-ligand interactions were analysed using both statistical and machine-learning approaches. Drug-resistant mutations were predicted not only to target active sites in an orthosteric manner, but also to act through allosteric mechanisms arising from distant sites, sometimes at the protein-protein interface

    Daksha: On Alert for High Energy Transients

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    We present Daksha, a proposed high energy transients mission for the study of electromagnetic counterparts of gravitational wave sources, and gamma ray bursts. Daksha will comprise of two satellites in low earth equatorial orbits, on opposite sides of earth. Each satellite will carry three types of detectors to cover the entire sky in an energy range from 1 keV to >1 MeV. Any transients detected on-board will be announced publicly within minutes of discovery. All photon data will be downloaded in ground station passes to obtain source positions, spectra, and light curves. In addition, Daksha will address a wide range of science cases including monitoring X-ray pulsars, studies of magnetars, solar flares, searches for fast radio burst counterparts, routine monitoring of bright persistent high energy sources, terrestrial gamma-ray flashes, and probing primordial black hole abundances through lensing. In this paper, we discuss the technical capabilities of Daksha, while the detailed science case is discussed in a separate paper.Comment: 9 pages, 3 figures, 1 table. Additional information about the mission is available at https://www.dakshasat.in

    Science with the Daksha High Energy Transients Mission

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    We present the science case for the proposed Daksha high energy transients mission. Daksha will comprise of two satellites covering the entire sky from 1~keV to >1>1~MeV. The primary objectives of the mission are to discover and characterize electromagnetic counterparts to gravitational wave source; and to study Gamma Ray Bursts (GRBs). Daksha is a versatile all-sky monitor that can address a wide variety of science cases. With its broadband spectral response, high sensitivity, and continuous all-sky coverage, it will discover fainter and rarer sources than any other existing or proposed mission. Daksha can make key strides in GRB research with polarization studies, prompt soft spectroscopy, and fine time-resolved spectral studies. Daksha will provide continuous monitoring of X-ray pulsars. It will detect magnetar outbursts and high energy counterparts to Fast Radio Bursts. Using Earth occultation to measure source fluxes, the two satellites together will obtain daily flux measurements of bright hard X-ray sources including active galactic nuclei, X-ray binaries, and slow transients like Novae. Correlation studies between the two satellites can be used to probe primordial black holes through lensing. Daksha will have a set of detectors continuously pointing towards the Sun, providing excellent hard X-ray monitoring data. Closer to home, the high sensitivity and time resolution of Daksha can be leveraged for the characterization of Terrestrial Gamma-ray Flashes.Comment: 19 pages, 7 figures. Submitted to ApJ. More details about the mission at https://www.dakshasat.in

    Synthesis, growth, structural, optical and electrical properties of novel organic single crystal: p-toluidinium salicylate

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    A novel organic single crystal of p-toluidinium salicylate (PTSA) was grown by slow evaporation solution growth technique. The structure of grown crystal was determined from the single crystal X-ray diffraction analysis. The functional groups existing in PTSA crystal were accomplished by using Fourier transform infrared analysis. The optical transparency and band gap energy were estimated by utilizing the UV-Visible spectrum. Photoluminescence spectral studies revealed the photon excitation. The dielectric behavior of PTSA was investigated for different frequencies in a room temperature (308 K) environment. Third-order nonlinear optical susceptibility (χ3) of PTSA crystal was elucidated by Z-scan measurements

    Solid Particle Erosion Studies of Varying Tow-Scale Carbon Fibre-Reinforced Polymer Composites

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    Solid particle erosion inevitably occurs if a gas–solid or liquid–solid mixture is in contact with a surface, e.g., in pneumatic conveyors. Nowadays, an erosive failure of the component after the usage of a long period has been gaining the interest of the researchers. In this research work, carbon fibre-reinforced polymer (CFRP) composites are prepared by varying the tow sizes of fibres, such as 5k, 10k, and 15k. The prepared composites are subjected to erosion studies by varying the process parameters, such as the impact angle (30, 60, and 90 degrees) and velocity (72, 100, and 129 m/s). The Taguchi orthogonal array design has been employed for the experimental plan and the erosion rate and surface roughness are observed for each run. The changes in the responses are reported for varying process parameters. The higher erodent velocity of 129m/s leads to higher erosion rates and forms poor surface quality. The minimum impact angle of 30 degrees provides higher erosion rates and higher surface roughness than the other impingement angles. Finally, the eroded surface of each sample is examined through microscopic and 3D profilometer images and the erosion mechanism is analysed at different conditions. The eroded particles supplied at lower speeds do not penetrate the composite surface. However, it is well-known that the lower the collision force, the harder the traces on the surface, yet no sign of fibre breaking or pull-out is observed. The passage of erodent particles on the composite caused surface waviness (flow trace), which prevents the surface from degrading

    Modelling Approach for the Prediction of Machinability in Al6061 Composites by Electrical Discharge Machining

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    This work aims to identify the pattern for the major output parameters, material removal rate (MRR) and surface roughness (Ra) of different combinations of Al6061-based composites. Based on the verification carried out on these patterns using analysis of variance (ANOVA) as the mathematical tool, the work predicts the mentioned output characteristics while machining Al6061 composites of different material compositions based on their hardness values. ANOVA was employed for the generation of equations of the particular composite. The equations were compared for the coefficients of each parameter employed in ANOVA. The work was carried out comparing the characteristic equation of different combinations of Al6061-based composite. The results indicate that the coefficients of the current show a drastic variation when compared to other coefficients for both the output parameters. It was observed that the current and its coefficients contribute to the output parameters based on the variation in hardness. For surface roughness, the constant of the characteristic equation was also found to influence the parameter for the change in hardness. The equation derived for both material removal rate (MRR) and surface roughness (Ra) were identified to be matching with the experimental result carried out for validation. The average variation observed was 9.3% for MRR and 7.2% for surface roughness

    Modelling Approach for the Prediction of Machinability in Al6061 Composites by Electrical Discharge Machining

    No full text
    This work aims to identify the pattern for the major output parameters, material removal rate (MRR) and surface roughness (Ra) of different combinations of Al6061-based composites. Based on the verification carried out on these patterns using analysis of variance (ANOVA) as the mathematical tool, the work predicts the mentioned output characteristics while machining Al6061 composites of different material compositions based on their hardness values. ANOVA was employed for the generation of equations of the particular composite. The equations were compared for the coefficients of each parameter employed in ANOVA. The work was carried out comparing the characteristic equation of different combinations of Al6061-based composite. The results indicate that the coefficients of the current show a drastic variation when compared to other coefficients for both the output parameters. It was observed that the current and its coefficients contribute to the output parameters based on the variation in hardness. For surface roughness, the constant of the characteristic equation was also found to influence the parameter for the change in hardness. The equation derived for both material removal rate (MRR) and surface roughness (Ra) were identified to be matching with the experimental result carried out for validation. The average variation observed was 9.3% for MRR and 7.2% for surface roughness
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