A Novel Inter Connection of DFIG with Grid in Separate Excitation SMES System with Fuzzy Logic Control

The use of doubly fed induction generators (DFIGs) in wind turbines has become quite common over the last few years. DFIG wind turbine is an integrated part of distributed generation system. This paper presents a Fuzzy based controller SMES unit in DFIG for improving the ac output on grid side. The excitation system is composed of the rotor-side converter, the grid-side converter, the dc chopper and the superconducting magnet. The superconducting magnet is connected with the dc side of the two converters, which can handle the active power transfer with the rotor of DFIG and the power grid independently, even thou Sutton small fluctuations are occur in active power on AC side. For smoothening the AC output power waveform a Fuzzy based controller is introduced in SMES controller unit, which implemented using simulation developed in MATLAB/ SIMULINK 7.2 version. The model of the FUZZY controlled SMES based excitation system for DFIG is established, and the simulation tests are performed to evaluate the system performance

Global phase synchronization in an array of time-delay systems

We report the identification of global phase synchronization (GPS) in a linear array of unidirectionally coupled Mackey-Glass time-delay systems exhibiting highly non-phase-coherent chaotic attractors with complex topological structure. In particular, we show that the dynamical organization of all the coupled time-delay systems in the array to form GPS is achieved by sequential synchronization as a function of the coupling strength. Further, the asynchronous ones in the array with respect to the main sequentially synchronized cluster organize themselves to form clusters before they achieve synchronization with the main cluster. We have confirmed these results by estimating instantaneous phases including phase difference, average phase, average frequency, frequency ratio and their differences from suitably transformed phase coherent attractors after using a nonlinear transformation of the original non-phase-coherent attractors. The results are further corroborated using two other independent approaches based on recurrence analysis and the concept of localized sets from the original non-phase-coherent attractors directly without explicitly introducing the measure of phase.Comment: 11 pages, 13 figures, Appear in Physical Review

Analysis of Advanced Encryption Standards

The Advanced Encryption Standard (AES),the block cipher ratified as a standard by National Instituteof Standards and Technology of the United States (NIST), waschosen using a process markedly more open and transparentthan its predecessor, the aging Data Encryption Standard(DES).Fifteen algorithm were submitted as to NIST in 1998 ,NIST choose five finalist.NIST primary selection criteria are security, performance,and flexibility. This paper enlightens the last two criteria. Inthis paper we have discussed software performance of five AESfinalist.The paper specifically compares performance of the fiveAES finalist on a verity of common software platform: 32-bitCPU( both large and smaller microprocessors, smart cards,embedded microprocessors) and high end 64-bits CPUs

Thyroid hormones reference ranges during each trimester of normal pregnancy subjects in Andhra Pradesh, South India

Background: The Thyroid hormones normal levels are very much essential for fetal neural development and good pregnancy outcome. Thyroid insufficiency during pregnancy may be associated with adverse obstetric outcome and fetal neurodevelopmental deficits. The main objective of the study is to estimate and establish the reference ranges of thyroid hormones as it varies from place to place and inter dependent on the iodine levels as the American Thyroid Association strongly recommends to refer to population defined trimester-specific reference ranges.Methods: A longitudinal study was conducted at obstetric clinic, Kakinada city, Andhra Pradesh over a period of 18 months. The total number of normal pregnancy subjects included in this study was 126. Thyroid hormones estimation was done by Competitive electrochemiluminescence (T3 and T4) and Sandwich electrochemiluminescence (TSH) at Thyorocare Laboratory. Only 47 subjects were having all three trimester thyroid hormone levels estimated during each trimester and were followed up to full term. The 2.5th and 97.5th percentiles were calculated as the reference intervals for thyroid hormone levels during each trimester.Results: The thyroid hormone levels during first, second and third trimesters median with reference intervals - Total Triiodothyronine (T3) : 163(100.2-230), 168(121-219.2), 168(110.2-222.6) ng/dl ,Total Thyroxine (T4) : 8.4(4.05-16.64) , 10.2(4.09-18.7), 11.2(3.8-16.7) μg/dl and Thyroid Stimulating Hormone (TSH ):2.52(1.6-7.9) 3.01(1.28-7.6) 3(1.5-8.4) μIU/mlConclusions: The trimester-specific reference intervals and median for thyroid hormones during normal pregnancy have been established for pregnant South Indian women in Andhra Pradesh by full term follow-up during pregnancy using 2.5th and 97.5th percentiles and median

Ultrasound and Doppler evaluation of salivary gland pathology

Background: Lesions of salivary gland are very commonly encountered in clinical practice. Only by Clinical examination alone it is difficult to differentiate between them and know its exact cause and etiology. It would definitely benefit the patient as well as the doctor if they could get an idea of the exact type of lesion affecting the salivary gland. Hence, this study was undertaken to demonstrate as how high resolution ultrasound imaging and use of colour Doppler can be useful in evaluation of salivary gland lesions.Methods: Duration of study was1yearwith sample size of 30 patients. This study has been conducted in the department of Radiodiagnosis JNMC, Sawangi, Wardha all cases irrespective of age and sex referred to the department were evaluated. Aloka Prosound Alpha 7 USG machine with a high resolution probe linear transducer was used. The lesions were evaluated by high resolution real time ultrasound and colour Doppler.Results: Most of the patients were in the age group 41-50years and had male preponderance. Most presented with unilateral swelling which was tender and firm in consistency. Amongst the study group saladenitis was most frequent finding followed by pleomorphic adenoma and carcinoma. Pleomorphic adenoma was most common neoplasm having predilection for the parotid gland. Saladenitis was most common in submandibular gland. The commonest histopathological finding was pleomorphic adenoma.Conclusions: The study concludes that High resolution ultrasound can differentiate various salivary gland lesions. Addition with colour Doppler ultrasound can increase its diagnostic accuracy. High resolution ultrasound with colour Doppler sonography should be first line of imaging modality in suspected cases of salivary gland lesions

Direct observation of 4+ to 2+ gamma transition in 8Be

The low lying states in $^8$Be are believed to have a two-alpha cluster structure and hence a large intrinsic quadrupole deformation. An earlier calculation showed a large collective enhancement in gamma transition probability between the low lying states leading to a 4$^+$ to 2$^+$ gamma branch of $\sim10^{-7}$ and a resonant radiative cross section of 134 nb for the $\alpha+\alpha$ entrance channel. We report here the first experimental evidence for this transition through a $\gamma-\alpha-\alpha$ coincidence measurement in the reaction $^4$He($\alpha,\alpha \gamma$)$^4$He using a gas target. The measured cross sections on and off the 4$^+$ resonance are 165 $\pm$ 41 (stat) $\pm$35 (sys) nb and 39 $\pm$ 25 (stat) $\pm$7 (sys) nb, respectively.Comment: Total 4 pages, 4 figures, in RevTeX format, submitted to PR

Tachyonic potential in Bianchi type-I universe

Motivated from recent string theoretic results, a tachyonic potential is constructed for a spatially homogeneous and anisotropic background cosmology.Comment: 5 pages,LATEX,Typos in the text corrected, more references adde