Optimization of Shield Thickness of Finite-Length Solid Rotors for Eddy-Current Loss Minimization

Shah, M.R.,Sang Bin Lee IEEE 2009 IEEE transactions on industry applications Vol.45 No.6

<P>A high-conductivity shield is often used for coating the rotor of solid-rotor synchronous machines for reducing the surface eddy-current losses due to armature-reaction space/time harmonics and/or tooth ripple. Since the design process for determining the optimal shield thickness can be complicated and time consuming, a simple analytical model based on Maxwell's equations was developed and presented in a previous paper to simplify the process. It has been shown that such an analytical tool can be used as a quick and effective ldquoscreening toolrdquo for determining the range of the optimal shield thickness for minimizing rotor surface losses; however, the influence of finite rotor axial length including the end-face losses was not taken into account. In this paper, an additional step is introduced in the shield design process where a special finite-element (FE) method that accounts for the impact of finite rotor axial length is employed for refining the design obtained from the analytical solution. Comparisons are made for a number of shield thicknesses and rotor lengths for significant space and time harmonic combinations to verify the validity of the proposed two-step design process (analytical and FE) and to evaluate the impact of the finite length of solid rotors.</P>

Nonplanar Solitons in a Degenerate Multi-species Plasma

M. G. Shah,A. A. Mamun,M. R. Hossen 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.8

The nonlinear propagation of cylindrical and spherical positron-acoustic solitary waves (PASWs) in an unmagnetized, collisionless, relativistic, degenerate plasma system that consists of nonrelativistic inertial cold positrons, relativistic degenerate electron and hot positron fluids, and positively-charged immobile ions has been investigated theoretically. By using a reductive perturbation technique, we derive the Korteweg-de Vries (K-dV) equation. The solitary wave solution has been numerically analyzed to comprehend the localized electrostatic disturbances. We observed that the effects of the degenerate pressure, relativity, and the number densities of inertial cold positrons, hot positrons, electrons, and positively-charged static ions notably modify the fundamental features of the cylindrical and the spherical PASWs. The implications of our results for dense plasmas in astrophysical compact objects (e.g., non-rotating white dwarfs, neutron stars, etc.) are briefly discussed.

Effects of taurine on heat shock proteins of liver and muscle in chronic heat stressed broilers

D. R. Kang,Shah Ahmed Belal,E. S. R. Cho,J. R. Park,G. H. Park,M. J. Lee,K. S. Shim 한국가금학회 2018 한국가금학회 정기총회 및 학술발표회 Vol.2018 No.10

Toxicity studies on Trigonella foenum-graecum L. seeds used in spices and as a traditional remedy for diabetes

Al-Ashban, R.M.,Abou-Shaaban, R.R.,Shah, A.H. Kyung Hee Oriental Medicine Research Center 2010 Oriental pharmacy and experimental medicine Vol.10 No.2

Acute (24 h) and chronic (90 days) oral toxicity studies on the ethanol extract of Trigonella foenumgraecum Leguminosae (L.) seeds were carried out. Acute dosages were 0.5, 1.0 and 3 g/kg while chronic dosage was 100 mg/kg per day of the extract. All morphological, biochemical, haematological and spermatogenic changes, in addition to mortality, body weight changes and any change in vital organs were recorded. Histopathological investigations were done on vital organs. Growth arrest in the treated animals was observed. The treated mice gained no significant weight during chronic treatment while there was a significant gain in body weight of the control group mice. Biochemical studies revealed a significant decrease in blood sugar levels of fenugreek treatment groups while haematological parameters remained comparable to the control. In the treatment, male group there was a significant decrease in weight of testes as compared to the control. There was a marginal weight gain in kidney weight of mice after chronic treatment as compared to the control. Fenugreek chronic treatment caused a highly significant spermatotoxic effects in male mice.

Numerical analysis of channel connectors under fire and a comparison of performance with different types of shear connectors subjected to fire

S.E.M. Shahabi,N.H. Ramli Sulong,M. Shariati,M. Mohammadhassani,S.N.R. Shah 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.3

The behavior of shear connectors plays a significant role in maintaining the required strength of a composite beam in normal and hazardous conditions. Various types of shear connectors are available and being utilized in the construction industry according to their use. Channel connectors are a suitable replacement for conventional shear connectors. These connectors have been tested under different types of loading at ambient temperature; however, the behavior of these connectors at elevated temperatures has not been studied. This investigation proposes a numerical analysis approach to estimate the behavior of channel connectors under fire andcompare it with the numerical analysis performed in headed stud and Perfobond shear connectors subjected to fire. This paper first reviews the mechanism of various types of shear connectors and then proposes a non-linear thermomechanical finite element (FE) model of channel shear connectors embedded in high-strength concrete (HSC) subjected to fire. Initially, an accurate nonlinear FE model of the specimens tested at ambient temperature was developed to investigate the strength of the channel-type connectors embedded in an HSC slab. The outcomes were verified with the experimental study performed on the testing of channel connectors at ambient temperature by Shariati <i>et al</i>. (2012). The FE model at ambient temperature was extended to identify the behavior of channel connectors subjected to fire. A comparative study is performed to evaluate the performance of channel connectors against headed stud and Perfobond shear connectors. The channel connectors were found to be a more economical and easy-to-apply alternative to conventional shear connectors.

Field Evaluation of Mungbean Recombinant Inbred Lines against Mungbean Yellow Mosaic Disease Using New Disease Scale in Thailand

Khalid P. Akhtar,R. Kitsanachandee,P. Srinives,G. Abbas,M. J. Asghar,T. M. Shah,B. M. Atta,O. Chatchawankanphanich,G. Sarwar,M. Ahmad,N. Sarwar 한국식물병리학회 2009 Plant Pathology Journal Vol.25 No.4

Studies were conducted to identify the sources of resistance in mungbean recombinant inbred lines (RILs) in Thailand against mungbean yellow mosaic disease (MYMD). 146 mungbean RILs in F8 series were evaluated in a field including resistant parent NM-10- 12-1 and susceptible parent KPS 2 during summer 2008 under high inoculum pressure. The RILs were subsequently scored for disease symptom severity ratings (DSSR) using a new scale. Observations regarding DSSR and % disease index (%DI) showed that the tested RILs responded differently to the disease. A large number of RILs (132) were found highly susceptible, 12 were susceptible, 3 were tolerant and one was resistant. Overall screening results showed that three RILs, viz. line no. 30, 100 and 101 had minimum DSSR and % disease index thus they are good source of resistance to MYMD in spite of high disease pressure and can therefore be used directly as varieties to manage the disease in Thailand.

Field Evaluation of Mungbean Recombinant Inbred Lines against Mungbean Yellow Mosaic Disease Using New Disease Scale in Thailand

Akhtar, Khalid P.,Kitsanachandee, R.,Srinives, P.,Abbas, G.,Asghar, M.J.,Shah, T.M.,Atta, B.M.,Chatchawankanphanich, O.,Sarwar, G.,Ahmad, M.,Sarwar, N. The Korean Society of Plant Pathology 2009 Plant Pathology Journal Vol.25 No.4

Studies were conducted to identify the sources of resistance in mungbean recombinant inbred lines (RILs) in Thailand against mungbean yellow mosaic disease (MYMD). 146 mungbean RILs in $F_8$ series were evaluated in a field including resistant parent NM-10-12-1 and susceptible parent KPS 2 during summer 2008 under high inoculum pressure. The RILs were subsequently scored for disease symptom severity ratings (DSSR) using a new scale. Observations regarding DSSR and % disease index (%DI) showed that the tested RILs responded differently to the disease. A large number of RILs (132) were found highly susceptible, 12 were susceptible, 3 were tolerant and one was resistant. Overall screening results showed that three RILs, viz. line no. 30, 100 and 101 had minimum DSSR and % disease index thus they are good source of resistance to MYMD in spite of high disease pressure and can therefore be used directly as varieties to manage the disease in Thailand.

X-RAY ASTRONOMY EXPERIMENT ON THE INDIAN SATELLITE IRS-P3

AGRAWAL P. C.,PAUL B.,RAO A. R.,SHAH M. R.,MCKERJEE K.,VARIA M. N.,YADAV J. S.,DEDHIA D. K.,MALKAR J. P.,SHAH P.,DAMLE S. V.,MARAR T. M. K.,SEETHA S. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

An x-ray astronomy experiment consisting of three collimated proportional counters and an X-ray Sky Monitor (XSM) was flown aboard the Indian Satellite IRS-P3 launched on March 21, 1996 from SHAR range in India. The Satellite is in a circular orbit of 830 km altitude with an orbital inclination of $98^{\circ}$ and has three axis stabilized pointing capability. Each pointed-mode Proportional Counter (PPC) is a multilayer, multianode unit filled with P-10 gas ($90\%$ Ar + $10\%\;CH_4$) at 800 torr and having an aluminized mylar window of 25 micron thickness. The three PPCs are identical and have a field of view of $2^{\circ}{\times}2^{\circ}$ defined by silver coated aluminium honeycomb collimators. The total effective area of the three PPCs is about 1200 $cm^2$. The PPCs are sensitive in 2-20 keV band. The XSM consists of a pin-hole of 1 $cm^2$ area placed 16 cm above the anode plane of a 32 cm$\times$32 cm position sensitive proportional counter sensitive in 3-8 keV interval. The position of the x-ray events is determined by charge division technique using nichrome wires as anodes. The principal objective of this experiment is to carry out timing studies of x-ray pulsars, x-ray binaries and other rapidly varying x-ray sources. The XSM will be used to detect transient x-ray sources and monitor intensity of bright x-ray binaries. Observations of black-hole binary Cyg X-1 and few other binary sources were carried out in early May and July-August 1996 period. Details of the x-ray detector characteristics are presented and preliminary results from the observations are discussed.

Control of Fowl Typhoid Using Tissue Culture Medium Waste After Harvest of Korean Wild Ginseng <i>(Panax ginseng)</i>

Shah, D.H.,Seol, J.-W.,Park, S.-Y.,Ryu, K.-S.,Kwon, J.-T.,Cho, M.-R.,Park, J.-H.,Kang, C.-S.,Kang, H.-S.,Chae, J.-S. Elsevier 2005 The Journal of applied poultry research Vol.14 No.3

<P><B>Abstract</B></P> <P>Fowl typhoid (FT), caused by <I>Salmonella gallinarum</I> (SG), is responsible for heavy economic losses through morbidity, mortality, and reduced egg production to the poultry industry worldwide. The use of alternative medications to control FT is important in light of emergence of multiple drug-resistant strains of SG and the public's desire to have organically grown poultry. We report the efficient utilization of tissue culture medium waste after harvest of Korean wild ginseng (TCM-KWG) <I>(Panax ginseng)</I> as an alternative medicine in the control of FT. In a series of experiments performed in this study, we found that oral administration of TCM-KWG through drinking water significantly reduced the mortality, organ invasiveness, and fecal shedding of SG in 1-d-old chickens experimentally infected with virulent SG. The results were positively correlated with higher dose and longer duration of pretreatment with TCM-KWG in relation to reduction in mortality caused by FT. The results of this work indicate that the TCM-KWG may be used as a cost-effective and environmentally friendly alternative medicine to control and minimize the losses due to FT in chickens.</P>

Ultra-High Strength Mg-9Gd-4Y-0.5Zr Alloy with Bi-Modal Structure Processed by Traditional Extrusion

M. Hong,S. S. A. Shah,D. Wu,R.S. Chen,X. H. Du,N. T. Hu,Y. F. Zhang 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.6

It is usual to observe that multi-scale structures can lead to combined strength and ductility both in aluminumalloys and steels, but related research has been seldom reported yet in magnesium alloys. In this study, applyingtraditional one step extrusion, we have successfully obtained a bimodal (Mg-9Gd-4Y-0.5Zr) alloy capable ofultra-high strength. The characterized sample reveal a bi-modal microstructure with two constitutions, i.e. stretchedcoarse-grain region with strong basal fiber texture and recrystallization fine-grain region. The bi-modal structuredsample exhibit excellent mechanical properties with an ultimate strength 508 MPa and elongation 8% via400 °C extrusion and subsequently 200 °C-60 h peak aging process. Ultra-high strength can be attributed toits strong extrusion texture in stretched coarse grains and dispersed nano-scale precipitates. This uniquebimodal structure could be produced easily by one step extrusion, which is quite reliable and low costs inindustrial applications of magnesium alloys with ultra-high strength as well as ideal ductility.