1,319 research outputs found

    SOLAR POWERED THREE PHASE MOTOR FOR VARIOUS APPLICATIONS

    Get PDF
    The Power electronics plays a vital role in the conversion and control of the electrical power for various applications such as heating & lightning control, electrochemical processes, DC & AC electrical machine drives, electrical welding, active power line filtering, static var compensator and many more.The main aim of the paper is to analyze and design of a current fed push pull DC-DC boost converter to integrate three phase electric motor through inverter. The regulated output which is obtained by the developed converter is fed to a typical load side inverter, and then to the various loads. To analyze the CFPP DC-DC converter in different operating cycles. The hardware circuit will be designed to test for the required output.Among the existing DC/DC converters, current-fed push-pull (CFPP) converter is a better option owing to its voltage boosting, isolation and compact characteristics

    An Application of Analytic Hierarchy Process in Vehicle Routing Problem

    Get PDF
    Vehicle Routing Problem (VRP) facilitates on finding a set of trips, one for each vehicle and to deliver known quantities of goods from a single depot to a set of geographically dispersed customers. This paper proposes an effective hybrid approach that combines customer prioritization with the Clarke and Wright's savings algorithm to solve the capacitated vehicle routing problem. In this model, in addition to traditional objective of resolving vehicle routing problem, the customer satisfaction have been taken into account. Initially, all the customers have been clustered with the help of Clarke and Wright's saving algorithm and later the customers have been prioritized on assigning optimal route using Analytic Hierarchy Process (AHP) as a Multi Criteria Decision Making (MCDM) tool. The highlight of this research is to diminish the total transportation cost without violating the vehicle capacity and ultimately improve the customer satisfaction

    Beeswax–EVA/Activated-Charcoal-Based Fuels for Hybrid Rockets: Thermal and Ballistic Evaluation

    Get PDF
    Beeswax (C46H92O) is a naturally derived substance that has the potential to be used as a solid fuel for hybrid rocket applications and as a substitute for paraffin wax fuel in hybrid rockets. BW burns more efficiently than paraffin wax because of the oxygen molecule it contains. The low thermal stability and poor mechanical properties of BW limit its practical use for upper-stage propulsion applications, and these issues are rarely addressed in the literature on hybrid rockets. This study investigates the thermal stability and ballistic properties of BW using ethylene-vinyl acetate (EVA) and activated charcoal (AC) as an additive. The thermal stability of BW–EVA/AC fuel compositions was analyzed using a thermogravimetric analyzer (TGA). The thermal stability of the blended BW compositions improved significantly. A laboratory-scale hybrid rocket motor was used to evaluate such aspects of ballistic performance as regression rate, characteristic velocity, and combustion efficiency. The results revealed that the pure BW exhibited a higher regression rate of 26.5% at an oxidizer mass flux of 96.4 kg/m2-s compared to BW–EVA/AC blends. The addition of EVA and AC to BW was found to increase the experimental characteristic velocity and combustion efficiency. The combustion efficiency of BW-based fuel was improved from 62% to 94% when 20 wt.% EVA and 2 wt.% AC were added into the fuel matrix

    Enhancement of power quality using microprocessor based shunt active power filter for unbalanced load

    Get PDF
    Power quality is the most significant factor of power sector. The end user equipment such as induction motor, inverters, rectifiers inject harmonics into power system that influences the quality of power delivered. The presence of harmonics forces the use of instantaneous reactive power theory to calculate instantaneous power that helps in finding the compensating currents to eliminate harmonics. The control action required by active filter is accomplished by STM32F303RET6 microcontroller. Single phase induction motor is used as a dynamic nonlinear load in one of the three phases and resistive loads on the other two phases. TRIAC based RC triggering circuit was used to control the single phase induction motor. This paper presents the simulation and hardware implementation of shunt active power filter for 3 phase 4 wire unbalanced system. The hardware results show that THD in the source side has been reduced from 50.7% to 9.6% by implementing the SAPF

    Neurobehavioral toxicity in progeny of rat mothers exposed to methylmercury during gestation

    Get PDF
    Introduction. Methylmercury (MeHg) is recognized as one of the most hazardous environmental pollutants. This may be a concern to long-term consumption of contaminated fish and seafood for health risk to pregnant women and their children. Aim. An animal study was conducted to assess the effect of MeHg exposure on rodent offspring following in utero exposure.Methods. Pregnant Wister rats were treated by gavage with MeHg at dose levels of 0.5, 1.0 and 2.0 mg/kg/day from gestation day (GD) 5 till parturition, and then were allowed to deliver. Results. Dams treated with 2.0 mg/kg/day MeHg group showed signs of toxicity such as gait alterations and hyperactivity resulting in the failure to deliver sustainable viable pups. MeHg had significant effects on body weight gain of dams during GD 5 till parturition. MeHg had no significant effects on the ages of physical developments such as pinna detachment, incisor eruptions or eye opening as well as alter cliff avoidance, surface righting, swimming ontogeny, startle reflex, pivoting, negative geotaxis, or forelimb and hindlimb grip strength in either sex. Exposure to 1.0 mg/kg/day MeHg treatment group prolonged gestation period, retard mid-air righting in male pups, shortened forelimb grip strength measured on rotating rod in either sex and enhanced open field behaviour in male pups. Data obtained from Functional Observation Battery (FOB) also revealed impairment of neuromotor performance in male pups. The male pups appeared to be more susceptible than the female pups. Conclusion. Overall, the dose level of MeHg in the present study produced a few adverse effects on the neurobehavioral parameters, and it may alter neuromotor performance of the male pups. 

    Evaluation of modified Alvarado score in the diagnosis of acute appendicitis

    Get PDF
    Background: Acute appendicitis, the most common surgically correctable cause of abdominal pain, the diagnosis of which remains difficult in many instances and is essentially clinical. However a decision to operate based on clinical suspicion alone can lead to removal of normal appendix in 15-30% cases. Several diagnostic scoring systems have been devised as an aid to early diagnosis of acute appendicitis and to reduce the incidence of negative appendicectomy. One such scoring system was described by Alvarado and later modified by Kalan et al. The present study is attempted to evaluate the efficiency of modified Alvarado score in pre-operative diagnosis of acute appendicitis.Methods: One hundred twenty consecutive patients suspected of acute appendicitis that were admitted, investigated and treated were taken for the study. After detailed examination and investigations a modified Alvarado score was applied to these patients. They were assigned in three groups and were treated accordingly.Results: The result of the study showed that high scores in men and children (7-9) had a sensitivity of 92.3% and 83.3% respectively, whereas in females it had a sensitivity of 72.7%. The score (5-6) in males and females had a sensitivity of 57% and 50% respectively.Conclusions: The high scores in modified Alvarado score is dependable aid in the early diagnosis of acute appendicitis in men and children but it’s not true as far as women are considered. Ultrasonography of abdomen is a useful tool in avoiding negative appendicectomy rates particularly in females.

    Genetic Correlation and Cluster Analysis in Sapota (Manilkara zapota)

    Get PDF
    Sapota is classified into two main types based on fruit shape as 'round' and 'oval'. However, there are several intermediates, as, it is a heterozygous tree crop. In this study, an effort was made to group available variability in sapota based on fruit characters and to analyze it. This helps in selection of parents for use in further breeding programmes. Cluster analysis revealed four definite clusters. High variability was observed for fresh-fruit weight, fruit length, fruit girth, fruit weight at ripening, pulp weight, peel weight, number of seeds and TSS. Correlation studies among fruit parameters indicated positive relationship between all the parameters studied, except TSS which had negative relationship with the rest of the fruit parameters. Selection of distantly placed cultivars in breeding programs stands to result in better progeny for further evaluation

    Low Speed Estimation of Sensorless DTC Induction Motor Drive Using MRAS with Neuro Fuzzy Adaptive Controller

    Get PDF
    This paper presents a closed loop Model Reference Adaptive system (MRAS) observer with artificial intelligent Nuero fuzzy controller (NFC) as the adaptation technique to mitigate the low speed estimation issues and to improvise the performance of the Sensorless Direct Torque Controlled (DTC) Induction Motor Drives (IMD). Rotor flux MRAS and reactive power MRAS with NFC is explored and detailed analysis is carried out for low speed estimation. Comparative analysis between rotor flux MRAS and reactive power MRAS with PI as well as NFC as adaptive controller is performed and results are presented in this paper. The comparative analysis among these four speed estimation methods shows that reactive power MRAS with NFC as adaptation mechanism shows reduced speed estimation error and actual speed error at steady state operating conditions when the drive is subjected to low speed operation. Simulation carried out using MATLAB-Simulink software to validate the performance of the drive especially at low speeds with rated and variable load conditions

    Synthesis and interaction of thiazolo [2, 3-a] isoquinoline analog with DNA

    Get PDF
    569-573A reaction between 1-(furan-2-yl)-3,4-dihydroisoquinoline and thioglycolic acid using N,N-Dicyclohexylcarbodiimide at 0−5 °C has given 10b-(furan-2-yl)-5,6-dihydro-2H-thiazolo[2,3-a]isoquinolin-3(10bH)-one [FUIQTGA]. The interaction between FUIQTGA and DNA has been studied using UV-visible spectroscopy, fluorescence and circular dichroism techniques. Static quenching mechanism is observed from fluorescence measurements of interaction between FUIQTGA and DNA. Circular dichroism reveals the minor groove binding mode between FUIQTGA and DNA

    MSCT coronary angiography in non-invasive assessment of coronary artery bypass grafts patency

    Get PDF
    Background: Coronary artery disease (CAD) is one of the leading cause of the morbidity and mortality in India and worldwide and last decade has seen a steep rise in incidence of CAD in India and its treatment as bypass surgery. Direct visualization of the grafts and native coronary arteries by invasive catheterization is now being replaced by non-invasive CT coronary angiography with higher slice machines and newer technology as it has good temporal resolution, high scanning speed as well as low radiation dose. We share our experience of graft imaging on 128 slice CT machine.Methods: This is a retrospective, single-center, observational study. We included 500 symptomatic patients who have undergone CT study between the year 2014 to 2018 post bypass surgery.Results: Arterial grafts have a better patency rate than venous grafts. (88% vs. 64.1%). Amongst the individual arterial grafts RIMA had the best patency rate (100%) followed by LIMA (90.8%), RA (68.7%). LAD was the most commonly involved artery (91%).Conclusions: Significant absolute concordance between CT and catheter angiographic findings have been documented for all arterial and venous grafts patency in the literature. The MSCT with retrospective gating permits an accurate and non-invasive evaluation of patent and diseased arterial and vein grafts and could replace conventional angiography for the follow-up of symptomatic, stable patients. Moreover, an optimal diagnostic accuracy was also documented in the appraisal of native vessels distal to the graft anastomoses
    corecore