189 research outputs found

    A Novel Approach to PID Controller Design for Improvement of Transient Stability and Voltage Regulation of Nonlinear Power System

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    In this paper, a novel design method for determining the optimal PID controller parameters for non-linear power system using the particle swarm optimization (PSO) algorithm is presented. The direct feedback linearization (DFL) technique is used to linearize the nonlinear system for computing the PID (DFL-PID) controller parameters. By taking an example of single machine infinite bus (SMIB) power system it has been shown that PSO based PID controller stabilizes the system and restores the pre-fault system performance after fault is cleared and line is restored. The performance of this controlled system is compared with the performance of DFL-state feedback controlled power system. It has been shown that the performance of DFL-PID controlled system is superior compared to DFL-state feedback controlled system. For simulation MATLAB 7 software is used.

    A prospective observational study of demographic profile in patients of amoebic and pyogenic liver abscesses in a tertiary care hospital

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    Background: Liver abscesses, both amoebic and pyogenic, continue to be an important cause of morbidity and mortality in tropical countries. Pyogenic liver abscess is a serious, life-threatening condition with a high mortality rate that represents a diagnostic and therapeutic challenge. In India, due to poor sanitary condition and a lower socioeconomic status, amoebiasis is endemic and amoebic liver abscess accounts for 3-9% of all cases of amoebiasis. Aim and objectives of current study was to study demographic profile in patients of amoebic and pyogenic liver abscesses. Methods: A detailed history was taken from each of these patients and all of them were subjected to a through clinical examination. Results: The highest incidence occurred in the age group 31-50 years; males were more commonly affected than females. Fever and pain abdomen were the most consistently occurring symptoms. All the patients with liver abscess had abdominal tenderness. 17 patients (74%) with liver abscess were alcoholics. 8 patients (80%) with amoebic liver abscess were alcoholic as compared to 9 patients (69%) in pyogenic liver abscess. Conclusions: Pyogenic organisms were most common cause of liver abscess

    Effect of mineral fertilizer, pig manure, and Azospirillum rugosum on growth and nutrient contents of Lactuca sativa L

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    Benefits from the application of plant growth-promoting bacteria in agriculture largely depend on the complex interactions between several factors including the nature of fertilizers selected. This study was designed to determine the fine tuning between the inoculated bacteria and different fertilizers and their effect on the growth of lettuce plants (Lactuca sativa L.). Plant growth promotion by a novel species of the genus Azospirillum, namely A. rugosum IMMIB AFH-6, was tested by biochemical, bioassay, and greenhouse studies. The treatments used in the greenhouse study were; unfertilized control (Blank), half recommended dose of chemical fertilizer (1/2CF), full recommended dose of chemical fertilizer (1CF), pig manure fertilizer (PMF), pig manure fertilizer + half recommended dose of chemical fertilizer (PMF + 1/2CF), and pig manure fertilizer + full recommended dose of chemical fertilizer (PMF + 1CF). All these treatments when inoculated with A. rugosum IMMIB AFH-6 inoculation were, respectively, In-Blank, In-1/2CF, In-1CF, In-PMF, In-PMF + 1/2CF, and In-PMF + 1CF. Significant increase in plant biomass and shoot N, P, Ca, and Fe was shown in the In-Blank treatment. Plant growth in soil amended with PMF and A. rugosum IMMIB AFH-6 was significantly lower than in soil treated with the chemical fertilizer, but inoculation combined with chemical fertilizer significantly elevated the plant biomass. The In-PMF + 1/2CF treatment showed the highest yield. A. rugosum IMMIB AFH-6 facilitated the accumulation of trace minerals in higher concentrations when PMF was combined with 1CF. To examine the benefits of inoculation by A. rugosum IMMIB AFH-6, we have proposed a new type of data analysis which considers both biomass and nutrient content of plants. This new type of analysis has shown the importance of the mineral content of plant

    Phytochemical Investigation and Evaluation of Antibacterial Activity of Zizyphus Xylopyrus (Retz) Willd Leaf Extract

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    An experiment was carried out to evaluate the antibacterial activity of the Zizyphus xylopyrus ethanolic fractions, which was related to the phytoconstituents present. The plant's root powder was extracted using an ethanol extraction procedure that involved several consecutive steps. Following this, the extracted product displayed a distinct scent feature. Tannic acid, phenol, and flavonoids were found, indicating the existence of the required phytochemicals. The flavonoids were isolated using spectroscopic characterisation using the ethanolic extract. After then, this extract was used for additional pharmacological testing because in the study, only ethanolic extracts and saponins were used. Based on each sample's results from a variety of qualitative tests, this analysis was carried out. The discovery of new illnesses, especially those brought on by Enterococcus and Staphylococcus species, has sparked increased interest in the study of therapeutic plants in recent decades. These microorganisms have become resistant to widely used antibiotics and are the cause of a considerable proportion of hospital-acquired illnesses. For example, S. aureus, which was once sensitive to a number of antibiotics, is now showing signs of resistance to several medication

    Classification of Metals used in the Sand Casting Process

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    The Sand Casting Process And The Different Methods Used To Cast The Metals Are The Subjects Of This Paper. Casting Is A Manufacturing Process For Creating Complex Material Shapes. A Large Classification Is Needed To Understand The Metals Used By Researches, Why They Were Used, And What The Most Commonly Used Metal For Their Research Is. We Studied And Understanded The Various Types Of Sand Casting Processes Used By The Researchers In This Review Paper. And We Categorized And Graded All The Papers We Reviewed And Classified Based On Their Respective Study Areas And Material Use
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