30 research outputs found

    A novel hybrid topology for power quality improvement using multilevel inverter for the reduction of vibration and noise in brushless DC motor for industrial applications

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    The proposed research involves the design and implementation of a novel hybrid Topology for Power Quality Improvement using Multilevel Inverter to reduce vibration and noise in BLDC motor for industrial applications. The utility of power electronics device plays a vital role for various applications in recent days. Similarly, the power consumption is also important for all processing units. The power electronic devices contain a lot of converters for processing the energy. During such cases, the harmonics are produced in different ways. Hence, a system analysis is necessary to find the problem at conventional methods. Hence the problem is identified on the distribution static compensator (DSTATCOM) component module whose harmonics are high, and it is important module for the circuit, hence preventive action to be taken to reduce the harmonics. To limit or reduce the harmonics, it is required to modify the triggering mechanism and control unit of Multi level inverter. Hence, the proposed hybrid method is implemented with the developed H-bridge and diode clamped topology with a brushless dc motor. In addition, the vibrations and the noise level are also reduced due to the reduced total harmonic distortion. The proposed module is simulated on MATLAB Simulink, and an experimental analysis is carried out to verify functionality tools with various operating conditions, the proposed method proves more efficient than the switches and complex networks present in traditional methods

    Further results on stability analysis of Takagiā€“Sugeno fuzzy time-delay systems via improved Lyapunovā€“Krasovskii functional

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    The problem of delay-range-dependent (DRD) stability analysis for continuous time Takagiā€“Sugeno (Tā€“S) fuzzy time-delay systems (TDSs) is addressed in this paper. An improved DRD stability criterion is proposed in an linear matrix inequality (LMI) framework by constructing an appropriate delay-product-type (DPT) Lyapunovā€“Krasovskii functional (LKF) to make use of Bessel-Legendre polynomial based relaxed integral inequality. The modification in the proposed LKF along with the judicious choice of integral inequalities helps to obtain a less conservative delay upper bound for a given lower bound. The efficacy of the obtained stability conditions is validated through the solution of three numerical examples

    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

    Evaluation of polyherbal formulation and synthetic choline chloride on choline deficiency model in broilers: implications on zootechnical parameters, serum biochemistry and liver histopathology

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    Objective The study was designed to establish choline deficiency model (CDM) in broilers for evaluating efficacy of polyherbal formulation (PHF) in comparison with synthetic choline chloride (SCC). Methods A total of 2,550 one-day-old Cobb 430 broiler chicks were randomly assigned to different groups in three experiments. In experiment 1, G1 and G2 served as normal controls and were fed a basal diet with 100% soybean meal (SBM) as a major protein source supplemented with and without SCC, respectively. In G3, G4, G5, and G6 groups, SBM was replaced at 25%, 50%, 75%, and 100% by soy protein isolate (SPI) to induce a graded level of choline deficiency. In experiment 2, PHF (500 and 1,000 g/ton) in comparison with SCC (1,000 g/ton) were evaluated. In experiment 3, dose-response of PHF (200, 400, and 500 g/ton) with SCC (400 g/ton) was determined. Results Replacement of SBM by SPI produced a linear decrease in body weight gain (BWG) with a poor feed conversion ratio (FCR). 25% SBM replacement by SPI yielded an optimum negative impact on BWG and FCR; hence, it is considered for further studies. In experiment 2, PHF (500 and 1,000 g/ton) and SCC (1,000 g/ton) showed a similar performance in BWG, FCR and relative liver weight. In experiment 3, PHF produced an optimum efficacy at 400 g/ton and was comparable to SCC in the restoration of serum aspartate aminotransferase activity, abdominal fat, breast muscle lipid content and liver histopathological abnormalities. Conclusion Replacement of SBM by SPI caused choline deficiency characterised by worsening of BWG, FCR, elevation in liver enzymes and histopathological changes indicating fatty liver. CDM was found valid for evaluating SCC and PHF. It is concluded that PHF has the potential to mimic biological activities of SCC through the restoration of negative effects caused by CDM

    Understanding the molecular basis of plant growth promotional effect of Pseudomonas fluorescens on rice through protein profiling

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    <p>Abstract</p> <p>Background</p> <p>Plant Growth Promoting Rhizobacteria (PGPR), <it>Pseudomonas fluorescens </it>strain KH-1 was found to exhibit plant growth promotional activity in rice under both <it>in-vitro </it>and <it>in-vivo </it>conditions. But the mechanism underlying such promotional activity of <it>P. fluorescens </it>is not yet understood clearly. In this study, efforts were made to elucidate the molecular responses of rice plants to <it>P. fluorescens </it>treatment through protein profiling. Two-dimensional polyacrylamide gel electrophoresis strategy was adopted to identify the PGPR responsive proteins and the differentially expressed proteins were analyzed by mass spectrometry.</p> <p>Results</p> <p>Priming of <it>P. fluorescens</it>, 23 different proteins found to be differentially expressed in rice leaf sheaths and MS analysis revealed the differential expression of some important proteins namely putative p23 co-chaperone, Thioredoxin h- rice, Ribulose-bisphosphate carboxylase large chain precursor, Nucleotide diPhosphate kinase, Proteosome sub unit protein and putative glutathione S-transferase protein.</p> <p>Conclusion</p> <p>Functional analyses of the differential proteins were reported to be directly or indirectly involved in growth promotion in plants. Thus, this study confirms the primary role of PGPR strain KH-1 in rice plant growth promotion.</p

    Experimental and computational vibration analysis for diagnosing the defects in high performance composite structures using machine learning approach

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    Delamination in laminated structures is a concern in high-performance structural applications, which challenges the latest non-destructive testing techniques. This study assesses the delamination damage in the glass fiber-reinforced laminated composite structures using structural health monitoring techniques. Glass fiber-reinforced rectangular laminate composite plates with and without delamination were considered to obtain the forced vibration response using an in-house developed finite element model. The damage was diagnosed in the laminated composite using machine learning algorithms through statistical information extracted from the forced vibration response. Using an attribute evaluator, the features that made the greatest contribution were identified from the extracted features. The selected features were further classified using machine learning algorithms, such as decision tree, random forest, naive Bayes, and Bayes net algorithms, to diagnose the damage in the laminated structure. The decision tree method was found to be a computationally effective model in diagnosing the delamination of the composite structure. The effectiveness of the finite element model was further validated with the experimental results, obtained from modal analysis using fabricated laminated and delaminated composite plates. Our proposed model showed 98.5% accuracy in diagnosing the damage in the fabricated composite structure. Hence, this research work motivates the development of online prognostic and health monitoring modules for detecting early damage to prevent catastrophic failures of structures

    Enhanced SARS-CoV-2-Specific CD4+ T Cell Activation and Multifunctionality in Late Convalescent COVID-19 Individuals

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    Background: Examination of CD4(+) T cell responses during the natural course of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection offers useful information for the improvement of vaccination strategies against this virus and the protective effect of these T cells. Methods: We characterized the SARS-CoV-2-specific CD4(+) T cell activation marker, multifunctional cytokine and cytotoxic marker expression in recovered coronavirus disease 2019 (COVID-19) individuals. Results: CD4(+) T-cell responses in late convalescent (>6 months of diagnosis) individuals are characterized by elevated frequencies of activated as well as mono, dual- and multi-functional Th1 and Th17 CD4(+) T cells in comparison to early convalescent (<1 month of diagnosis) individuals following stimulation with SARS-CoV-2-specific antigens. Similarly, the frequencies of cytotoxic marker expressing CD4(+) T cells were also enhanced in late convalescent compared to early convalescent individuals. Conclusion: Our findings from a low-to middle-income country suggest protective adaptive immune responses following natural infection of SARS-CoV-2 are elevated even at six months following initial symptoms, indicating the CD4(+) T cell mediated immune protection lasts for six months or more in natural infection

    Characterization of memory T cell subsets and common Ī³āˆ’chain cytokines in convalescent COVID-19 individuals

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    T cells are thought to be an important correlates of protection against SARSā€CoV2 infection. However, the composition of T cell subsets in convalescent individuals of SARSā€CoV2 infection has not been well studied. The authors determined the lymphocyte absolute counts, the frequency of memory T cell subsets, and the plasma levels of common Ī³āˆ’chain in 7 groups of COVIDā€19 individuals, based on days since RTā€PCR confirmation of SARSā€CoVā€2 infection. The data show that both absolute counts and frequencies of lymphocytes as well as, the frequencies of CD4(+) central and effector memory cells increased, and the frequencies of CD4(+) naĆÆve T cells, transitional memory, stem cell memory T cells, and regulatory cells decreased from Days 15ā€“30 to Days 61ā€“90 and plateaued thereafter. In addition, the frequencies of CD8(+) central memory, effector, and terminal effector memory T cells increased, and the frequencies of CD8(+) naĆÆve cells, transitional memory, and stem cell memory T cells decreased from Days 15ā€“30 to Days 61ā€“90 and plateaued thereafter. The plasma levels of ILā€2, ILā€7, ILā€15, and ILā€21ā€”common Ī³c cytokines started decreasing from Days 15ā€“30 till Days 151ā€“180. Severe COVIDā€19 patients exhibit decreased levels of lymphocyte counts and frequencies, higher frequencies of naĆÆve cells, regulatory T cells, lower frequencies of central memory, effector memory, and stem cell memory, and elevated plasma levels of ILā€2, ILā€7, ILā€15, and ILā€21. Finally, there was a significant correlation between memory T cell subsets and common Ī³c cytokines. Thus, the study provides evidence of alterations in lymphocyte counts, memory T cell subset frequencies, and common Ī³āˆ’chain cytokines in convalescent COVIDā€19 individuals

    Evaluation of a polyherbal topical aerosol spray as a supportive therapy for clinical mastitis in dairy cows

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    The present study was designed to evaluate the polyherbal topical aerosol spray Wisprec and reg; Advanced (M/S. Natural Remedies Private Limited, India) as a supportive therapy for clinical mastitis in dairy cows. A total of 41 dairy cows suffering from clinical mastitis were selected, and Wisprec and reg; Advanced was sprayed on mastitis affected quarters of udder two times a day along with a parenteral antibiotic till complete recovery. The rectal temperature, pain on palpation of udder, swelling of udder, consistency of milk, recovery period and product satisfaction score were assessed to evaluate the efficacy of Wisprec and reg; Spray. Topical application of Wisprec and reg; Advanced Spray have shown a significant improvement (p<0.001) in alleviation of rectal temperature, pain on palpation of udder and swelling of udder, and the consistency of milk was restored to normal after 3 to 4 days of treatment. The results demonstrate that the Wisprec and reg; Advanced spray could be considered as an alternative to non-steroidal anti-inflammatory drugs (NSAIDs) as a supportive therapy for clinical mastitis of dairy cows. [J Adv Vet Anim Res 2015; 2(3.000): 285-290
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