373 research outputs found
Fault Classification in double circuit transmission lines using ANN
—— This paper discusses the application of ANN techniques for classification of all type of faults on double circuit transmission lines. It is very challenging task to provide distance protection a double circuit transmission line .An accurate algorithm for fault classification of single line to ground fault, double line to ground fault, three phase faults in double circuit transmission line presented using feed forward neural network (FFNN) algorithm. The algorithm used the fundamental components of voltage and current signals which is taken from the simulation diagram. This technique not requires the online data from the other communication link to retrieve the remote end data nor other sequence current compensation for healthy phases are required. This is a major advantage of the proposed technique for protection of double circuit line. Results of study on a 250 kV transmission line fed from both the ends are presented as an illustration. Simulation results indicate that algorithm is immune to the effect of mutual coupling, fault resistance and fault type
Development and Optimization of Fast Dissolving Tablets of Losartan Potassium Using Natural Gum Mucilage
Current research work involves preparation of fast dissolving tablets of Losartan Potassium by direct compression method using different concentrations of Plantago ovata and Lepidium sativum mucilage as natural superdisintegrants. A two factor three level (32) factorial design is being used to optimize the formulation. Nine formulation batches (A1-A9) were prepared by taking two factors as independent variables (X1- amount of Plantago ovata mucilage and X2- amount of Lepidium sativum mucilage)were taken with three levels (+1, 0, -1). All the active blends were evaluated for precompression parameters (angle of repose, bulk density, carr’s index, hausner’s ratio) and formulated tablets were evaluated for post compression parameters (hardness, friability, weight variation, wetting time, disintegration time, water absorption ratio). In vitro drug release studies were carried out using USP II dissolution apparatus for 30 min. The software Design Expert (8.0.7.1) was used for generating experimental design, modeling the response surface and calculating the statistical evaluation. Tablet parametric tests of formulation batches (A1-A9) of FDT were found within prescribed limits.DT was observed in the range from 12±2 to 58.7±2.52 sec and WT from 10.3±1.52 to 49.7±5.13 sec for formulation batches (A1-A9). More than 87% drug release was observed in all formulation batches (A1-A9) within 15 minutes. Polynomial mathematical models, generated for various response variables using multiple linear regression analysis, were found to be statistically significant (P < 0.05). Formulation A7 was selected by the design expert software which exhibited DT (22.15sec), WT (17.31sec) and in vitrodrug release (100%) within 15 minutes
In vivo effects of nonionic and ionic contrast media on beta-thromboglobulin and fibrinopeptide levels
AbstractNonionic contrast media are suggested to cause increased thromboembolism (in vivo), platelet aggregation and procoagulant effect (in vitro) as compared with ionic contrast media. To study these effects in vivo, 30 consecutive patients undergoing routine angiography were prospectively randomized to three groups of 10 patients each. Group A received diatrizoate (ionic, high osmolality), Group B ioxaglate (ionic, low osmolality) and Group C iohexol (nonionic, low osmolality). In vivo platelet alpha-granule release and fibrin-1 formation were measured by radioimmunoassay of beta-thromboglobulin and fibrinopeptide A in peripheral venous samples.Levels were estimated at three stages daring the procedure: before and after left ventriculography and after coronary angiography. No differences were noted (p = NS) when the ratios of beta-thromboglobulin and fibrinopeptide A were compared among the three groups. These data suggest that the newer nonionic contrast media do not demonstrate enhanced systemic platelet activation or fibrin formation as compared with standard ionic contrast media. However, larger randomized clinical studies are necessary to conclusively establish the suggested thromboembolic potential of nonionic contrast media
Utility of ranolazine in chronic stable angina patients
Chronic stable angina is a debilitating illness affecting at least 6.6 million US residents. Despite being optimally treated by pharmacotherapy and revascularization up to 26% of patients still experience angina. Diabetes mellitus is a common co-morbid condition in angina patients. Several new investigational medications are being tested for chronic angina. Advances in understanding of myocardial ischemia have prompted evaluation of a number of new antianginal strategies. In this review we discuss the utility of ranolazine, a recently approved novel antianginal agent and its efficacy in the diabetic patient population. In addition to its antianginal action in diabetic patients with chronic angina, ranolazine may have favorable effects on glycated hemoglobin levels
Comparison of 12-Month Outcomes with Zotarolimus- and Paclitaxel-Eluting Stents: A Meta-Analysis
Revascularization after myocardial infarction is often achieved via percutaneous coronary intervention, which often entails stenting. Drug-eluting stents have shown benefits over bare metal stents in this setting, and a variety of drug-eluting stents are now available, including sirolimus-, paclitaxel-, and zotarolimus-eluting stents. There are studies that have compared the various drug-eluting stents and this meta-analysis pools data comparing 12-month clinical outcomes of zotarolimus- and paclitaxel-eluting stents. End points studied were myocardial infarction, major adverse cardiac events, cardiac death, all-cause death, stent thrombosis, target vessel revascularization, and target lesion revascularization.There was a statistically significant reduction in risk of myocardial infarction (odds ratio, 0.250, confidence interval, 0.160 to 0.392) and statistically insignificant reductions in major adverse cardiac events (odds ratio, 0.813, confidence interval, 0.656 to 1.007), cardiac death (odds ratio, 0.817, confidence interval, 0.359 to 1.857), all cause death (odds ratio, 0.820, confidence interval, 0.443 to 1.516), and target lesion revascularization (odds ratio, 0.936, confidence interval 0.702 to 1.247). There was a statistically significant increase in target vessel revascularization (odds ratio, 1.336, confidence interval, 1.003 to 1.778) and a statistically insignificant increase in stent thrombosis (odds ratio, 1.174, confidence interval, 0.604 to 2.280). These findings are similar to the individual studies although other studies have noted increased late loss with zotarolimus-eluting stents and this current data associated with late loss should be kept in mind when makimg clinical decisions regarding sent selection
Derandomizing Isolation Lemma for K3,3-free and K5-free Bipartite Graphs
The perfect matching problem has a randomized NC algorithm, using the celebrated Isolation Lemma of Mulmuley, Vazirani and Vazirani. The Isolation Lemma states that giving a random weight assignment to the edges of a graph, ensures that it has a unique minimum weight perfect matching, with a good probability. We derandomize this lemma for K3,3-free and K5-free bipartite graphs, i.e. we give a deterministic log-space construction of such a weight assignment for these graphs. Such a construction was known previously for planar bipartite graphs. Our result implies that the perfect matching problem for K3,3-free and K5-free bipartite graphs is in SPL. It also gives an alternate proof for an already known result – reachability for K3,3-free and K5-free graphs is in UL.
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