7,159 research outputs found
LC compensators for power factor correction of nonlinear loads
No full textThis 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
LC compensators based on transmission loss minimization for nonlinear loads
No full textThis 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 IEEEThis paper presents a method employing the penalty function search algorithm to determine the LC compensator value for the optimal power factor correction in nonsinusoidal systems. The objective of the proposed method is to minimize the transmission loss while the power factor and efficiency are taken as constraints and utilized in order to solve the multiobjective optimization problem by transforming it into a single objective one. Examples show that the load nonlinearity can have a significant impact on optimal compensator sizes
Enhancement by benzodiazepines of the inhibitory effect of adenosine on skeletal neuromuscular transmission.
No full textSelective Antagonism to Succinylcholine-induced Depolarization by α- Bungarotoxin with Respect to the Mode of Action of Depolarizing Agents
No full textB-Eudesmol as an Antidote for Intoxicaiton from Organophosphorus Anticholinesterase Agensts
No full textChinese herb constituent beta-eudesmol alleviated the electroshock seizures in mice and electrographic seizures in rat hippocampal slices.
No full textLC-API/MS in Drug Metabolism and Pharmacokinetic Studies
No full textThe use of API interfaces with quadrupole mass spectrometers has been shown to give rise to good sensitivity, selectivity, and robustness for the interfacing of LC to MS. Since their introduction in the 1990s the technique has rapidly become widespread, but at the outset of this research programme, there were still a number of problems associated with it, particularly when dealing with complex sample matrices. The aim of this research programme was to study illustrative examples of the kinds of problems associated with the analysis of biological samples using LC-API-MS in an attempt to arrive at strategies which could be employed to eliminate, or at least compensate for, the problems.
Commonly reported problems include the occurrence of matrix effects - a change in response of the target analyte(s) as a result of the presence in the samples of co /late eluting interferences. An investigation which compared ESI with APCI ionisation illustrated a significant drawback in the accepted methodology for the elimination of matrix effects.
Optimal LC conditions for a number of assays may use non-MS-friendly mobile phases. A simple and convenient solution to this problem was found to be the post column addition of organic modifier, which reproducibly and reliably enhanced sensitivity. This approach was initially used for a range of dihydropyridine calcium channel blockers and was subsequently applied to a range of chiral compounds from different therapeutic groups to illustrate that this was applicable as a generic technique for increasing sensitivity (typically by around an order of magnitude) in low organic mobile phases.
Strategies to develop and validate methods for the determination of endogenous analytes in a biological fluid were investigated. This involved the use of a surrogate matrix, to develop a method for the determination of endogenous testosterone in human serum and the use of non-matrix calibration standards for the successful development and validation of a method for the analysis of indolyl 3 acryloylglycine (IAG) in human urine.
As a result of observations suggesting promotion of ionisation of deltamethrin in liver tissue sample extracts, it was postulated that this was due to the presence of high concentrations of surfactants. After confirming the effect, a series of systematic investigations were performed to attempt to understand the mechanism to be able to utilise this as a general method for the enhancement of signal with low sensitivity analytes. It was found that the type of surfactant and concentration used was directly associated with an increased (or decreased) response.
Although there remain a number of problems associated with the use of LC-API-MS, the work undertaken for this thesis has successfully demonstrated a number of techniques that can be applied to overcome these problems. Knowledge of the nature of the sample undergoing analysis, the required analytical conditions, and where required careful application of one of the techniques described will ensure that a robust method can be readily developed
LC-MS-P/N-ALL.xml
No full textMetabolic data of Artemisia argyi and Artemisia indica at different periods (LC-MS) .</p
LC-MS datasets details.
No full textAcute febrile illnesses are still a major cause of mortality and morbidity globally, particularly in low to middle income countries. The aim of this study was to determine any possible metabolic commonalities of patients infected with disparate pathogens that cause fever. Three liquid chromatography-mass spectrometry (LC-MS) datasets investigating the metabolic effects of malaria, leishmaniasis and Zika virus infection were used. The retention time (RT) drift between the datasets was determined using landmarks obtained from the internal standards generally used in the quality control of the LC-MS experiments. Fitted Gaussian Process models (GPs) were used to perform a high level correction of the RT drift between the experiments, which was followed by standard peakset alignment between the samples with corrected RTs of the three LC-MS datasets. Statistical analysis, annotation and pathway analysis of the integrated peaksets were subsequently performed. Metabolic dysregulation patterns common across the datasets were identified, with kynurenine pathway being the most affected pathway between all three fever-associated datasets.</div
2D-LC Characterization of Comb-Shaped Polymers Using Isotope Effect
No full textA rigorous molecular characterization of combshaped polystyrene (PS) was Carried out taking advantage of its molecular structure, a normal hydrogenous backbone, and deuterated side chains. Normal phase LC (NPLC) can separate the comb PS species well according to their molecular weight. Nonetheless, it cannot distinguish the backbone from the side chains and the differently structured polymers having a similar molecular weight, e.g, a single backbone comb and a coupled backbone comb with fewer side chains. In contrast to NPLC, the hydrogenous polymer is retained longer than the deuterated counterpart in reversed phase LC (RPLC). When the isotope sensitivity of RPLC is taken advantage of, the comb PS is cross fractionated by NPLC and RPLC, and a two-dimensional mapping with respect to the backbone chain length and the number of branches is fully established.X112321sciescopu
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