Practical considerations regarding power factor for nonlinear loads

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2004 IEEEThe choice of LC compensator may be constrained by the availability of manufacturers units. To account for this, the capacitor values are chosen from among standard values and for each value the transmission losses is minimized, or power factor is maximized, or transmission efficiency is maximized. The global minimum or maximum is obtained by scanning all local minims or maxims. The performance of the obtained compensator is discussed by means of numerical examples

LC compensators for power factor correction of nonlinear loads

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2004 IEEEA method is presented for finding the optimum fixed LC compensator for power factor correction of nonlinear loads where both source voltage and load current harmonics are present. The LC combination is selected because pure capacitive capacitors alone would not sufficiently correct the power factor. Optimization minimizes the transmission loss, maximizes the power factor, and maximizes the efficiency. The performance of the obtained compensator is discussed by means of numerical examples

Tyrosine kinase inhibitors for the therapy of anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is often incurable so new therapeutic approaches are needed. Tyrosine kinases inhibitors (such as imanitib, sunitinib or sorafenib) are under evaluation for the treatment of ATC. Other vascular disrupting agents, such as combretastatin A4 phosphate, and antiangiogenic agents, such as aplidin, PTK787/ZK222584 and human VEGF monoclonal antibodies (bevacizumab, cetuximab), have been evaluated. Small-molecule adenosine triphosphate competitive inhibitors directed intracellularly at EGFRs tyrosine kinase, such as erlotinib or gefitinib, are also studied. Furthermore, new molecules have been shown to be active against ATC, such as CLM94 and CLM3. However, more research is needed to finally identify therapies able to control and to cure this disease

Fungal iron availability during deep seated candidiasis is defined by a complex interplay involving systemic and local events

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In vitro evaluation of finger's hemodynamics for vein graft surveillance using electrical bio-impedance method

Electrical bio-impedance measurement has great potential in many biomedical applications including vein graft surveillance. Studies have shown that thrombosis was the major cause of the vein graft failure. The meticulous skills of the surgeon and effective postoperative surveillance of vein graft remain the cornerstones of clinical success in the current surgical management of vein graft survival. Vascular blood flow is the key clinical indicators for the evaluation of patency of the vein graft and ensuring the patient's quality of life. In this work, electrical bio-impedance method has been proposed as an alternative to the existing surveillance method as it is non-invasive, portable, easy applicable in practice, fast response, radiation free, and required only low-cost instrumentation. It was employed to measure pulsatile changes in longitudinal bio-impedance to quantify arterial blood flow and blood volume. We expect that by measuring the changes in tissue bio-impedance which can be used to evaluate important peripheral hemodynamic, it allows the detection of early stage stenosis within vascular and vein graft as well as estimate its severity with predetermined normative data provided

Effect of low-dose oral contraceptives on Lipid profile levels in Sudanese women using oral contraceptive pills

Background: Oral contraceptives provide highly reliable contraceptive protection even though imperfect use is considered, and are widely used worldwide.Objective: This study aimed to assess the effect of low dose combined oral contraceptive pills use on lipid profile levels in Sudanese women, and to find its correlation with age, BMI and duration of using oral contraceptive.Material and Methods: A clinically-based descriptive study was conducted during the period from May to October 2013. Sixty six women using low dose combined oral contraceptive were selected as a test group compared to sixty six apparently healthy non users as a control, attending the family planning center of Omdurman Maternity Hospital in Khartoum state, Sudan. Blood specimens were collected from both groups and serum levels of Total Cholesterol, Triglyceride and High Density Lipoprotein (HDL) were estimated and Low Density Lipoprotein (LDL) was calculated using Friedewaled equation.Results : Results showed a significant increase in the mean serum levels of Total Cholesterol, Triglyceride and HDL in the test group compared with the control group (p <0.05) and insignificant increase in the mean serum levels of LDL in the test group (P = 0.327). HDL levels decreased with age (P value 0.000) while Cholesterol, Triglyceride and LDL levels were not affected. The study also showed significant increase in Cholesterol, Triglyceride and decrease in HDL with duration of oral contraceptive use (P <0.05).The BMI was significantly higher in users than non-users (P 0.025).Conclusion: Combined oral contraceptive pills adversely affect the lipid profile. This may be due to drug responsiveness, as well as increased BMI. There isa correlation between duration of oral contraceptive use and lipid profile among the studied cases.Key words: Contraceptive pill, Low Doses, Serum lipids, Sudanese Women