S.Pradeepa, K.Uma Rao, Ravishankar Deekshit |
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Development of a Robust Constant Current Source For a Current Source Inverter | ||||||||||||
Current Source Inverter(CSI) has applications in the area of current protection. For CSI fed loads, when connected at a point of common coupling (PCC), the system voltage, may not always be a pure sinusoidal waveform, due to distortions created by other loads at the PCC. This paper presents two simple controllers, namely the comparator type and PI type, to derive and generate a constant current source, as input to be fed to the CSI. Results indicate that these controllers also work effectively even under distorted voltage waveform at the PCC. The controllers are validated for various source conditions and varying load conditions.
current source inverter; point of common coupling; constant current source; power quality; distorted voltage waveform.
[1]. Mustapha Raou-Moulay Tahar Lamchich "Average Current Mode Control Of A Voltage Source Inverter Connected To The Grid: Application To Different Filter Cells", Journal of Electrical Engineering, VOL. 55, NO. 3-4, 2004,77{82
[2]. Middlebrook, R. D., "Modeling Current Programmed Buck and Boost Regulators", IEEE Transactions on Power Electronics 4 No. 1 (1989). [3]. Pedro Gomes Barbosa, Henrique Antonio Carvalho Braga, Márcio do Carmo Barbosa Rodrigues and Estevão Coelho Teixeira, "Boost Current Multilevel Inverter And Its Application On Single-Phase Grid-Connected Photovoltaic", IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 4, JULY 2006. [4]. Muhammed H Rashid., " Power Electronic Circuits, Devices And Applications" Second Edition, Prentice Hall Of India Private Limited.
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Dr. Manish Upadhyay, Komal Kumari | ||||||||||||
Analytical Study of Fluoride Ion in Drinking Water around Ambikapur, Sarguja District, Chhattisgarh, India | ||||||||||||
Although fluoride was once considered an essential nutrient, the U.S. National Research Council has since removed this designation due to the lack of studies showing it is essential for human growth, though still considering fluoride a "beneficial element" due to its positive impact on oral health. The U.S. specifies the optimal level of fluoride to range from 0.7 to 1.2 mg/L (milligrams per liter, equivalent to parts per million). A 2000 systematic review found that water fluoridation was statistically associated with a decreased proportion of children with cavities (the median of mean decreases was 14.6%, the range −5 to 64%), and with a decrease in decayed, missing, and filled primary teeth (the median of mean decreases was 2.25 teeth, the range 0.5–4.4 teeth), which is roughly equivalent to preventing 40% of cavities.Fluoride's adverse effects depend on total fluoride dosage from all sources. At the commonly recommended dosage, the only clear adverse effect is dental fluorosis, which can alter the appearance of children's teeth during tooth development; this is mostly mild and is unlikely to represent any real effect on aesthetic appearance or on public health. The critical period of exposure is between ages one and four years, with the risk ending around age eight. Fluorosis can be prevented by monitoring all sources of fluoride, with fluoridated water directly or indirectly responsible for an estimated 40% of risk and other sources, notably toothpaste, responsible for the remaining 60%.
Fluoridation, dosage, fluorosis, aesthetic, consumption.
[1]. Burgstahler AW. Fluoridated bottled water [editorial]. Fluoride 2006; 39:252-4.
[2]. Shivarajashankara YM, Shivashankara AR, Rao SH, Bhar PG. Oxidative stress in childrenwith endemic skeletal fluorosis. Fluoride 2001; 34:103-7. [3]. Spittle B. Dyspepsia associated with fluoridated water. Fluoride 2008;41:89-92 [4]. Carton RJ. Review of the 2006 United States National Research Council Report: Fluoride in drinking water. Fluoride 2006; 39:163-72. [5]. Susheela AK, Jethanandani P. Circulating testosterone levels in skeletal fluorosis patients. J Toxicol Clin Toxicol 1996; 34:183-9....
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Prof Vikram singh Tamra, Robil varshney |
Data Mining By Parallelization of Fp-Growth Algorithm |
In this paper we present idea to make one main tree on master node and slave do processing with database rather than have multiple FP-trees, one for each processor Firstly, the dataset is divided equally among all participating processors Pi. Before the tree construction initiates, every processor must sort the items according to their support count. The master processor gathers all local counts to be summed together and ultimately form a global support count to be broadcasted to all processors in the group. Items having support count less than the minimum threshold are removed from the process in slave node as well as master node. The next step is the FP-tree construction in which each node scans and sends the transaction according to threshold. At the same time master node, make its tree and also updated the tree as items come from slave node.
Data Mining By Parallelization of Fp-Growth Algorithm
[1]. T. Imielinski R. Agrawal and A.N. Swami. A tree projection algorithm for generation of frequent item sets. Parallel and Distributed Computing, pages 350–371, March 2001 |
Bipadtaran Sinhamahapatra, Supriya Jana, Sudeshna Dey, Arnab Das, Bipa Datta, Moumita Mukherjee, Samiran Chatterjee |
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Dual-Band Size Deducted Un-Equal Arm Y-Shaped Printed Antenna for Satellite Communication | ||||||||||||
A dual-band deducted un-equal arm Y-shaped printed antenna is thoroughly simulated in this paper. Resonant frequency has been reduced drastically consists of Y-shaped slot in middle point located from the conventional microstrip patch antenna. It is shown that the simulated results are in acceptable agreement. More importantly, it is also shown that the differentially-driven microstrip antenna has higher gain of simulated 4.69 dBi at 6.23GHz and 4.18 dBi at 9.56GHz and beam width of simulated 170.380 at 6.23GHz and 166.1310at 9.56GHz of the printed antenna. Compared to a conventional microstrip patch antenna, simulated antenna size has been reduced by 52.02% with an increased frequency ratio.
Compact, Patch, Slot, Resonant frequency, Bandwidth.
[1]. I.Sarkar, P.P.Sarkar, S.K.Chowdhury "A New Compact Printed Antenna for Mobile Communication", 2009 Loughborough Antennas& Propagation Conference, 16-17 November 2009, pp 109-112.
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Samip Shah, Gaurang Chaudhri, Digvijay Kulshreshtha, S. A. Channiwalla | ||||||||||||
Radial Inflow Gas Turbine Flow Path Design | ||||||||||||
A new method for radial inflow gas turbine flow paths design based on a unique integrated conceptual design environment AxSTREAM is presented in this paper. This integrated environment is a seamless and swift processing scheme that incorporates stages aerodynamic analysis and preliminary design/sizing based on the one dimensional method. The environment makes possible to find number of different designs with inverse task solver, basing on initially specified boundary conditions, closing conditions and design variables. Design space explorer provides easy and visual comparison for range of obtained design in customizable coordinate axes. Solution filtering on different parameters, such as meridional and axial dimensions, maximal blades weight, saving the time to choose from thousands obtained solutions the only one right design. Flexibility of presented approach allows to built-up complete gas turbine flow path from consequence of individual elements: stationary and rotating elements, ducts, heat exchangers, and analyze it in common environment. Complete control of all aspects of aerodynamic flow path quality, structural reliability, and integral performances on design and offdesign conditions is performing throughout all design process. This gives full interaction between user and system for immediate correction and enhancement of current design data using various optimization capabilities to feel the impact of changes on each design step. Integrated system AxSTREAM significantly shortening the design cycle time from initial machine concept to finalized design with all offdesign performances details. The design process is demonstrated for a 25kW radial inflow gas turbine.
Radial Inflow Turbine, Performance Maps, AxSTREAM
[1]. Leonid Moroz, Yuri Govorusсhenko, Petr Pagur and Leonid Romanenko, "Integrated conceptual design environment for centrifugal compressors flow path design", ASME International Mechanical Engineering Congress and Exposition October 31-November 6, 2008, Boston, Massachusetts, USA.
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