Transformer-Less Cascaded Voltage Source Converter Based STATCOM

In this work, a transformer-less voltage source converter (VSC) based STATCOM is proposed with a combination of cascaded conventional three-phase voltage source inverters. This modular structure provides multilevel operation with reduced switch count and independent DC-link capacitors. The actual contribution of this paper is the transformer-less configuration of a conventional cascaded voltage source converter which provides reduced cost and volume as compared to other transformer-less converter configurations. The system provides reactive power compensation with better power quality when connected to the nonlinear power electronics load also. A simple control system is provided for balancing the Dc link capacitor voltage and reactive power compensation. The validation of the proposed model is analyzed with simulation using MATLAB/SIMULINK software and the results are obtained with different linear and nonlinear load configurations

Modified discrete Fourier transform algorithm for protection of shunt compensated distribution line

Introduction. The response time of the relay plays vital role when fault occurs on the line. Various algorithms are adopted to increase the sampling rate of the relay which, in turn, improves the response time. Methods. Discrete Fourier transform and modified discrete Fourier transform are the two algorithms used to calculate the fundamental frequency phasor of the signal required by the relay to initiate trip command. It is known that discrete Fourier transform takes four to five cycles to produce the fundamental frequency phasor but it fails to deal with the decaying DC component. On the other hand, modified discrete Fourier transform improves the response time by removing the decaying DC component along with the other harmonics in just one cycle and a few samples. The aim of this paper is to cover discrete Fourier transform and modified discrete Fourier transform algorithms to analyze the performance of the three overcurrent and one earth fault relaying scheme for different types of faults occurring in the distribution system. Methodology. The concept of three overcurrent and one earth fault scheme is also explained in this paper for protection of shunt-compensated distribution system. The scheme is designed for variable power factor. MATLAB/Simulink is used as the software tool to validate the results obtained for various types of faults occurring in the system. The results are represented graphically to illustrate the time of response of the protection scheme when shunt compensators are connected at the receiving end of distribution network.Вступ. Час спрацювання реле відіграє життєво важливу роль при виникненні несправності на лінії. Для збільшення частоти дискретизації реле застосовуються різні алгоритми, що, своєю чергою, покращує час спрацювання. Методи. Дискретне перетворення Фур’є та модифіковане дискретне перетворення Фур’є – це два алгоритми, які використовуються для розрахунку вектора основної частоти сигналу, необхідного для реле подачі команди на відключення. Відомо, що для отримання вектора основної частоти дискретного перетворення Фур’є потрібно від чотирьох до п'яти циклів, але воно не справляється з постійною складовою струму, що згасає. З іншого боку, модифіковане дискретне перетворення Фур’є покращує час спрацювання, видаляючи постійну складову струму, що згасає, разом з іншими гармоніками всього за один цикл і кілька вибірок. Мета цієї статті полягає в тому, щоб охопити алгоритми дискретного перетворення Фур’є та модифікованого дискретного перетворення Фур’є для аналізу характеристик трьох схем реле максимального струму та однієї схеми захисту від замикань на землю для різних типів несправностей, що виникають у розподільчій системі. Методологія. У статті  пояснюється також концепція трьох схем перевантаження по струму і однієї схеми замикання на землю для захисту розподільчої системи з паралельною компенсацією. Схема розрахована на змінний коефіцієнт потужності. MATLAB/Simulink використовується як програмний інструмент для перевірки результатів, отриманих для різних типів відмов, що виникають у системі. Результати представлені графічно, щоб проілюструвати час спрацьовування схеми захисту, коли шунтуючі компенсатори підключені на приймальному кінці розподільної мережі

Will Herbal-Paracetamol \u3cem\u3eCombination\u3c/em\u3e Drug Prevent both Liver and Kidney Disease? - Results and Possibilities

An attempt has been made to briefly review the existing information on herbal compounds which could combat acetaminophen (paracetamol) toxicity. A careful perusal of literature revealed that acetaminophen overdose not only damages liver but also the kidney. Nevertheless, the kidney was badly ignored in studies aimed at preventing paracetamol toxicity with herbal drugs. On account of such major neglect, so far no herbal-paracetamol combination could be made. Milk thistly is only well researched drug which appears as a suitable future candidate, but its action towards the kidney must be studied. The importance of such studies in the future is discussed

Endogenous transforming growth factor β1 suppresses inflammation and promotes survival in adult CNS

Transforming growth factor β1 (TGFβ1) is a pleiotropic cytokine with potent neurotrophic and immunosuppressive properties that is upregulated after injury, but also expressed in the normal nervous system. In the current study, we examined the regulation of TGFβ1 and the effects of TGFβ1 deletion on cellular response in the uninjured adult brain and in the injured and regenerating facial motor nucleus. To avoid lethal autoimmune inflammation within 3 weeks after birth in TGFβ1-deficient mice, this study was performed on a T- and B-cell-deficient RAG2-/- background. Compared with wild-type siblings, homozygous deletion of TGFβ1 resulted in an extensive inflammatory response in otherwise uninjured brain parenchyma. Astrocytes increased in GFAP and CD44 immunoreactivity; microglia showed proliferative activity, expression of phagocytosis-associated markers [αXβ2, B7.2, and MHC1 (major histocompatibility complex type 1)], and reduced branching. Ultrastructural analysis revealed focal blockade of axonal transport, perinodal damming of axonal organelles, focal demyelination, and myelin debris in granule-rich, phagocytic microglia. After facial axotomy, absence of TGFβ1 led to a fourfold increase in neuronal cell death (52 vs 13%), decreased central axonal sprouting, and significant delay in functional recovery. It also interfered with the microglial response, resulting in a diminished expression of early activation markers [ICAM1 (intercellular adhesion molecule 1), α6β1, and αMβ2] and reduced proliferation. In line with axonal and glial findings in the otherwise uninjured CNS, absence of endogenous TGFβ1 also caused an ∼10% reduction in the number of normal motoneurons, pointing to an ongoing and potent trophic role of this anti-inflammatory cytokine in the normal as well as in the injured brain. Copyright © 2007 Society for Neuroscience

Dually sensitive dextran-based micelles for methotrexate delivery

Temperature-sensitive polymeric micelles were prepared from dextran grafted with poly(N-isopropylacrylamide) (PNIPAAm) or polyethylene glycol methyl ether (PEGMA) via controlled radical polymerization and evaluated as delivery systems of the anticancer drug methotrexate (MTX). Polymer-grafting was carried out after introduction of initiating groups onto the polysaccharide backbone, without the need for protection of hydroxyl groups and avoiding the use of toxic solvents. Temperature-responsive dextran-based copolymers were designed to exhibit self-aggregation behaviour, affinity for MTX and high cellular internalization. In addition, some grafted polymers incorporated 2-aminoethyl methacrylate to reinforce MTX encapsulation in the micelles by means of ionic interactions. Dextran-based micelles were cytocompatible and had an appropriate size to be used as drug carriers. MTX release was dependent on the pH and temperature. The combination of poly(2-aminoethylmethacrylate) and PNIPAAm with the dextran backbone permitted the complete release of MTX at normal physiological temperature. Co-polymer micelles were highly internalized by tumour cells (CHO-K1) and, when loaded with MTX, led to enhanced cytotoxicity compared to the free drug

Characterization of Morinda tomentosa genotypes under rainfed conditions of western India

A field trial was conducted to characterize Morinda tomentosa Heyne ex Roth genotypes which were established during 2009 under field condition during the years 2011-13 at Experimental Farm of Central Horticultural Experiment Station (CIAH-ICAR) Vejalpur, Panchmahals (Godhra), Gujarat. The vegetative morphomatrix in terms of plant height, stem girth, plant spread, number of primary branches and number of secondary branches varied between 3.10-4.70 cm, 19.10-36.08 cm, 2.27-3.87 m, 6.23-13.45 and 12.12-26.00, respectively, whereas leaves morphology, viz. leaf length, breadth, petiole length and vein pairs ranged between 15.00-25.00 cm, 8.00-16.50 cm,1.25-2.29 cm and 7.43-11.33 per leaf, respectively. Yield /plant during 3rd year varied between 3.50-9.41 kg being highest in CHESN 1 and the lowest in CHESN 21 in all the evaluated genotypes. The quantitative fruit characters in terms of fruit weight, length, breadth, number of pyrines, number of seed/fruit and fresh weight of seed ranged between 19.20-47.10 g, 2.49-4.80 cm, 2.34-3.98 cm, 10.95-23.95, 25.17-50.65 and 0.06-0.11 g, respectively. Variations in values of TSS, pH, vitamin C and acidity, protein, phenols, tannins, Ca, K, Na, and Zn ranged between 6-120 brix, 3.50-7.00, 21.15-40.15 mg/ 100g, 1.16-1.51 per cent, 0.09-0.29 g, 11.12-20.05 mg, 0.25-0.46 g, 90.10-102.00 mg, 36.12-49.92 mg, 80.16-93.90 mg and 0.10-0.29 mg among the genotypes characterized for their biochemical composition. Based on the overall observations, CHESN 1, CHESN 16 and CHESN 31 were found to better with respect to most of the qualitative and quantitative characters than rest of the genotypes evaluated under rainfed conditions of western India

Virulence genes detection of Salmonella serovars isolated from pork and slaughterhouse environment in Ahmedabad, Gujarat

Aim: The aim was to detect virulence gene associated with the Salmonella serovars isolated from pork and Slaughterhouse environment. Materials and Methods: Salmonella isolates (n=37) used in this study were isolated from 270 pork and slaughter house environmental samples collected from the Ahmedabad Municipal Corporation Slaughter House, Ahmedabad, Gujarat, India. Salmonella serovars were isolated and identified as per BAM USFDA method and serotyped at National Salmonella and Escherichia Centre, Central Research Institute, Kasauli (Himachal Pradesh, India). Polymerase chain reaction technique was used for detection of five genes, namely invA, spvR, spvC, fimA and stn among different serovars of Salmonella. Results: Out of a total of 270 samples, 37 (13.70%) Salmonella were isolated with two serovars, namely Enteritidis and Typhimurium. All Salmonella serovars produced 284 bp invA gene, 84 bp fimA and 260 bp amplicon for enterotoxin (stn) gene whereas 30 isolates possessed 310 bp spvR gene, but no isolate possessed spvC gene. Conclusion: Presence of invA, fimA and stn gene in all isolates shows that they are the specific targets for Salmonella identification and are capable of producing gastroenteric illness to humans, whereas 20 Typhimurium serovars and 10 Enteritidis serovars can able to produce systemic infection

Stock assessment of Bombayduck Harpadon nehereus (Hamilton, 1822) from Gujarat coast using non-equilibrium production model

Bombayduck Harpadon nehereus, harvested mainly by dol nets (stationary bag nets), has been a prolific fishery in the northern region of Arabian Sea and Bay of Bengal. Biomass and maximum sustainable yield (MSY) estimates for the Bombayduck stock in the Saurashtra region were obtained from a non-equilibrium surplus production model approach utilising catch per unit effort (CPUE) time series derived from fish landing data. Fox model was found to be the most appropriate defining model and the results demonstrated that the stock is currently being overexploited