LIGHT WATER REACTOR (LWR) SAFETY

Sehgal Bal Raj Korean Nuclear Society 2006 Nuclear Engineering and Technology Vol.38 No.8

In this paper, a historical review of the developments in the safety of LWR power plants is presented. The paper reviews the developments prior to the TMI-2 accident, i.e. the concept of the defense in depth, the design basis, the large LOCA technical controversies and the LWR safety research programs. The TMI-2 accident, which became a turning point in the history of the development of nuclear power is described briefly. The Chernobyl accident, which terrified the world and almost completely curtailed the development of nuclear power is also described briefly. The great international effort of research in the LWR design-base and severe accidents, which was, respectively, conducted prior to and following the TMI-2 and Chernobyl accidents is described next. We conclude that with the knowledge gained and the improvements in plant organisation/management and in the training of the staff at the presently-installed nuclear power stations, the LWR plants have achieved very high standards of safety and performance. The Generation 3+LWR power plants, next to be installed, may claim to have reached the goal of assuring the safety of the public to a very large extent. This review is based on the historical developments in LWR safety that occurred primarily in USA, however, they are valid for the rest of the Western World. This review can not do justice to the many fine contributions that have been made over the last fifty years to the cause of LWR safety. We apologize if we have not mentioned them. We also apologize for not providing references to many of the fine investigations, which have contributed towards LWR safety earning the conclusions that we describe just above.

Poly-crystalline Silicon Thin Film Transistor: a Two-dimensional Threshold Voltage Analysis using Green's Function Approach

Sehgal, Amit,Mangla, Tina,Gupta, Mridula,Gupta, R.S. The Institute of Electronics and Information Engin 2007 Journal of semiconductor technology and science Vol.7 No.4

A two-dimensional treatment of the potential distribution under the depletion approximation is presented for poly-crystalline silicon thin film transistors. Green's function approach is adopted to solve the two-dimensional Poisson's equation. The solution for the potential distribution is derived using Neumann's boundary condition at the silicon-silicon di-oxide interface. The developed model gives insight into device behavior due to the effects of traps and grain-boundaries. Also short-channel effects and drain induced barrier lowering effects are incorporated in the model. The potential distribution and electric field variation with various device parameters is shown. An analysis of threshold voltage is also presented. The results obtained show good agreement with simulated results and numerical modeling based on the finite difference method, thus demonstrating the validity of our model.

Gut microbiome and checkpoint inhibitor colitis

( Kanika Sehgal ),( Sahil Khanna ) 대한장연구학회 2021 Intestinal Research Vol.19 No.4

Immune checkpoint inhibitor therapies such as ipilimumab, are increasingly being used as a treatment option for a variety of cancers, including metastatic melanoma and have demonstrated effectively a prolonged survival. These agents have an im-munological mode of action that predisposes patients to a number of immune-related adverse events, colitis being one of the most commonly encountered complications. The pathogenesis for the development of colitis is unclear, and there is a growing consensus that the ecosystem of the gastrointestinal microbiota plays a significant role. Based on this suspected connection, studies are being carried out to explore the changes in the microbiota in patients on these medications who develop colitis. Conceivably, the modulation of the gut microbiota could offer a therapeutic benefit. Fecal microbiota transplantation is one therapeutic option that is currently being investigated, though there are still more data needed to evaluate its efficacy. In this review, we recapitulate the mechanisms of action of immune checkpoint inhibitors, their adverse events, with a focus on colitis and the role gut microbiota are suspected to play, and finally discuss the microbiota modulation therapies being investigated. (Intest Res 2021;19:360-364 )

Integration from Retail Banking to Non-Financial Corporations in EMU

( Sanjay Sehgal ),( Priyanshi Gupta ),( Florent Deisting ) 세종대학교 경제통합연구소 2016 Journal of Economic Integration Vol.31 No.3

This paper investigates the integration process within the European Economic and Monetary Union’s retail banking industry by analyzing deposit and lending rates to nonfinancial corporations. The investigation covers the 2003~2014 period, examining the normal period, the global crisis period, and the European debt crisis period. The paper classifies sampled countries into three groups on the basis of their Gross Domestic Product to investigate the relationship between economic size and degree of integration. We employ five different indicators to assess various dimensions of integration: beta convergence, sigma convergence, variance ratio, asymmetric dynamic conditional correlation, and dynamic co-integration. The results point toward a weak degree of integration, which was worsened by the twin crises. In addition, results indicate that more heterogeneity exists in the credit market than in the deposits market. Furthermore, short-term maturity products are observed to be more converged than longer-term maturity products. We also observe a positive relationship between economic size of sampled countries and the degree of retail banking integration.

Action and Object Naming Deficit in Progressive Supranuclear Palsy

( Ruchi Sehgal ) 서강대학교 언어정보연구소 2013 언어와 정보 사회 Vol.20 No.-

Eight cases of progressive supranu-clear palsy (PSP) and eight normal subjects as control group were studied to examine whether their naming ability was affected or not. The naming ability that was examined was “action and object naming” of the patients with the help of a “picture naming test”, designed for Hindi speaking population. The paper aims to examine if there is any action and object naming deficits in Hindi speaking patients suffering from PSP. The study also analyzes the degree of impairment in the patients suffering from PSP. PSP patients exhibit “slurred speech” but is the impairment only “phonological” or the lexicon is also impaired? Finally the study aims to assess the degree of impairment manifested through PSP in nouns and verbs in PSP patients. PSP is caused due to damage to the frontal lobe which has been proven to be involved in con-trolling body movements. Earlier researches have established the fact that the damage to the frontal lobe always leads to the impairment of verbs (Cappa and Perani 2003; Cotelli 2006). However the current study also points out the noun impairment in PSP patients. This study is an attempt to understand the mental lexicon concentrating on the organization of nouns and verbs in the mental lexicon.

Poly-crystalline Silicon Thin Film Transistor

Amit Sehgal,Tina Mangla,Mridula Gupta,R. S. Gupta 대한전자공학회 2007 Journal of semiconductor technology and science Vol.7 No.4

A two?dimensional treatment of the potential distribution under the depletion approximation is presented for poly?crystalline silicon thin film transistors. Green’s function approach is adopted to solve the two?dimensional Poisson’s equation. The solution for the potential distribution is derived using Neumann’s boundary condition at the silicon?silicon di?oxide interface. The developed model gives insight into device behavior due to the effects of traps and grain?boundaries. Also short?channel effects and drain induced barrier lowering effects are incorporated in the model. The potential distribution and electric field variation with various device parameters is shown. An analysis of threshold voltage is also presented. The results obtained show good agreement with simulated results and numerical modeling based on the finite difference method, thus demonstrating the validity of our model.

Predicting Faults before Testing Phase using Halstead’s Metrics

Rajni Sehgal,Dr. Deepti Mehrotra 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.7

Software designers are motivated to utilize off-the-shelf software components for rapid application development. Such applications are expected to have high reliability as a result of deploying trusted components. This paper introduces Halstead’s software science to predict the fault before testing phase for component based system. Halstead’s software science is used to predict the faults for individual component and based on this faults reliability of different component is measured so that only reliable component will be reused.

Analysis of Electrical Properties of Ti/Pt/Au Schottky Contacts on (n)GaAs Formed by Electron Beam Deposition and RF Sputtering

B K Sehgal,V R Balakrishnan,R Gulati,S P Tewari 대한전자공학회 2003 Journal of semiconductor technology and science Vol.3 No.1

Effect of channel and plenum aspect ratios on the performance of microchannel heat sink under different flow arrangements

S. S. Sehgal,Krishnan Murugesan,S. K. Mohapatra 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.9

Microchannels based heat sinks are considered as potential thermal management solution for electronic devices. The overall thermal performance of a microchannel heat sink depends on the flow characteristics within microchannels as well as within the inlet and outlet plenum and these flow phenomena are influenced by channel aspect ratio, plenum aspect ratio and flow arrangements at the inlet and outlet plenums. In the present research work an experimental investigation has been carried out to understand how the heat transfer and pressure drop attributes vary with different plenum aspect ratio and channel aspect ratio under different flow arrangements. For this purpose microchannel test pieces with two channel aspect ratios, 4.72 and 7.57 and three plenum aspect ratios, 2.5, 3.0 and 3.75 have been tested under three flow arrangements, namely U-, S- and P-types. Test runs were performed by maintaining three constant heat inputs,125 W, 225 W and 375 W in the range 224.3 ≤ Re ≤ 1121.7. Reduction in channel width (increase in aspect ratio, defined as depth to width of channel) in the present case has shown about 126 to 165% increase in Nusselt number, whereas increase in plenum length (reduction in plenum aspect ratio defined as width to length of plenum) has resulted in 18 to 26% increase in Nusselt number.

Reaction of Global Collection of Rye (Secale cereale L.) to Tan Spot and Pyrenophora tritici-repentis Races in South Dakota

Abdullah, Sidrat,Sehgal, Sunish K.,Glover, Karl D.,Ali, Shaukat The Korean Society of Plant Pathology 2017 Plant Pathology Journal Vol.33 No.3

Rye (Secale cereale L.) serves as an alternative host of Pyrenophora tritici-repentis (PTR) the cause of tan spot on wheat. Rye is cultivated as a forage or cover crop and overlaps with a significant portion of wheat acreage in the U.S. northern Great Plains; however, it is not known whether the rye crop influences the evolution of PTR races. We evaluated a global collection of 211 rye accessions against tan spot and assessed the diversity in PTR population on rye in South Dakota. All the rye genotypes were inoculated with PTR races 1 and 5, and infiltrated with Ptr ToxA and Ptr ToxB, at seedling stage. We observed 21% of the genotypes exhibited susceptibility to race 1, whereas, 39% were susceptible to race 5. All 211 accessions were insensitive to both the Ptr toxins. It indicates that though rye exhibits diversity in reaction to tan spot, it lacks Ptr ToxA and ToxB sensitivity genes. This suggests that unknown toxins or other factors can lead to PTR establishment in rye. We characterized the race structure of 103 PTR isolates recovered from rye in South Dakota. Only 22% of the isolates amplified Ptr ToxA gene and were identified as race 1 based on their phenotypic reaction on the differential set. The remaining 80 isolates were noted to be race 4. Our results show that races 1 and 4 are prevalent on rye in South Dakota with a higher frequency of race 4, suggesting a minimal role of rye in the disease epidemiology.