Effect of balanced and unbalanced magnetron sputtering processes on the properties of SnO2 thin films

Gauri Shanker,P. Prathap,K.M.K. Srivatsa,Preetam Singh 한국물리학회 2019 Current Applied Physics Vol.19 No.6

A comparative study has been carried on the role of balanced magnetron (BM) and unbalanced magnetron (UBM) sputtering processes on the properties of SnO2 thin films. The oxygen partial pressure, substrate temperature and deposition pressure were kept 20%, 700 °C and 30 mTorr, respectively and the applied RF power varied in the range of 150–250 W. It is observed that the UBM deposition causes significant effect on the structural, electrical and optical properties of SnO2 thin films than BM as evidenced by X-ray diffraction, C-V, Spectroscopic Ellipsometer and Photoluminescence measurements. The value of band gap (Eg) of the films deposited at 150W in UBM is found as Eg=3.83 eV which is much higher than the value of Eg=3.69 eV as observed in BM sputtering indicating that UBM sputtering results in good crystalline quality. Further, the C-V measurements of SnO2 thin films deposited using UBM at high power 250W show hysteresis with large flat band shift indicating that these thin films can be used for the fabrication of memory device. The observed results have been attributed to different mechanisms which exist simultaneously under unbalanced magnetron sputtering due to ion bombardment of growing SnO2 thin film by energetic Ar+ ions.

Difficult airway: are we ever truly prepared?

Gauri Raman Gangakhedkar 대한마취통증의학회 2019 Korean Journal of Anesthesiology Vol.72 No.1

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The quest for patient safety

Gauri Raman Gangakhedkar 대한마취통증의학회 2019 Korean Journal of Anesthesiology Vol.72 No.3

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Effect of High Myopia on Optic Nerve Head by Confocal Scanning Laser Ophthalmoscopy in Nepalese Eyes

Gauri Shankar Shrestha,Sagun Narayan Joshi,Madhu Thapa,ananda kumar sharma 대한안과학회 2019 Korean Journal of Ophthalmology Vol.33 No.2

Purpose: To compare parameters of confocal scanning laser ophthalmoscopy (Heidelberg Retinal Tomograph[HRT] II) in high myopia with age- and sex-matched emmetropes. Methods: A hospital-based cross-sectional study was conducted among Nepalese subjects aged 18 to 35years at BP Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Maharajgunj, Kathmandu fromNovember 2015 to October 2016. Fifty consecutive subjects with high myopia (spherical equivalent rangingfrom -6.00 to -12.00 diopters) and age- and sex-matched emmetropic subjects were enrolled for comparison. Correlations between disc area and other HRT parameters, asymmetry between the right and left eyes, andcomparisons between male and female subjects in both high myopic and emmetropic groups were evaluated. Results: Disc area was not significantly (p = 0.11) larger in high myopic eyes than in emmetropic eyes. HRTparameters in highly myopic eyes involved smaller cup parameters and greater rim parameters comparedwith emmetropic eyes. Disc area was found to be significantly positively correlated with inter disc parametersand significantly negatively correlated with rim to disc area ratio in the high myopia group. Disc area and otherintra-disc parameters showed significant correlations between right and left eyes in both high myopia and emmetropia,and no significant differences between males and females from a Nepalese population. Conclusions: Characteristics of HRT parameters in high myopic eyes involved smaller cup parameters andgreater rim parameters compared with emmetropic eyes in a Nepalese population. The effect of disc area onHRT parameters differed significantly only in height variation contour by emmetropic eyes.

번역 : 태국의 미얀마 난민: 효과적 보호의 필요 -Cornell Law Library 2008

백범석,( Gauri Subramanium ),남송화(역) 연세대학교 법학연구원 공공거버넌스와 법센터 2011 연세 공공거버넌스와 법 Vol.2 No.1

엽록체 DNA 염기서열에 근거한 물여뀌 종집단(마디풀과)의 분류학적 연구

Gao Yaqian,Gauri Shankar Bhandari,박진희,박종욱 한국식물분류학회 2013 식물 분류학회지 Vol.43 No.1

마디풀과의 물여뀌 종집단(Polygonum amphibium L. complex)은 육상 및 수중 환경 모두에 서식할 수 있는 분류군으로, 서식 환경에 따라 다양한 형태 변이를 나타내어 현재까지 많은 분류군들이 기재되어 왔다. 아시아 및 북미산 107개체로부터 측정한 11개 형태형질을 사용하여 주성분분석을 수행한 결과, 본 종집단에서 존재하는 수생형 및 육생형 개체들은 모든 지역집단에서 잎의 형태 및 크기, 엽병의 길이 등에 의해 서로 구분되는 것으로 나타났다. 그러나, 동일 개체군 또는 동일 지역내에서 채집된 수생형과 육생형 개체들은 엽록체 DNA 4개 구간(matK, psbA-trnH IGS, rbcL-accD IGS, trnL-trnF)에서 완전히 동일한 염기서열을 공유하는 것으로 밝혀져 유전적으로는 분기되지 않은 것으로 추정되며, 따라서 본 종집단에서 나타나는 생육형간의 형태적 차이는 서식지 환경에 따른 개체 변이인 것으로 판단된다. 형태분석 및 엽록체 4구간 염기서열 유합자료의 계통분석 결과, 한국, 일본, 중국, 몽골, 극동 러시아 지역 등에 분포하는 아시아산 개체들은 북미지역집단 개체들 및 유럽의 영국산 개체와 형태적, 유전적으로 뚜렷이 구분되는 것으로 밝혀졌으며, 따라서 한반도산 개체들을 포함하는 아시아 지역집단 개체들은 P. amphibium의 하나의 변종(P. amphibium var. amurense Korsh.)으로 인식하는 것이 타당한 것으로 판단된다. The Polygonum amphibium complex (Poygonaceae) is a highly polymorphic taxon that can grow in aquatic environments as well as in moist terrestrial habitats. Aquatic and terrestrial plants of the P. amphibium complex vary significantly in morphology and exhibit very complicated patterns of morphological variation, resulting in the description of numerous infra-specific taxa. Principal components analysis of 107 individuals of the P. amphibium complex from Asia and North America using 11 morphological characters showed that the aquatic plants can be discerned from the terrestrial plants by leaf size, shape, and petiole length. In contrast, both aquatic and terrestrial plants collected from the same population or locality shared identical sequences in the matK, psbA-trnH IGS, rbcL-accD IGS and trnL-trnF regions of the chloroplast DNA (cpDNA), suggesting that aquatic and terrestrial forms of the P. amphibium complex are not genetically diverged; morphological differences between the two forms are probably due to the differences in environmental conditions of the habitats. In addition, results from the morphological analysis and the maximum parsimony analysis of the cpDNA data set revealed that the plants from Asia including Korea, Japan, China, Mongolia and Russia Far East are diverged from those in North America and Europe, suggesting that the Asian populations should be recognized as a distinct variety, P. amphibium var. amurense Korsh.

Post-lockdown spatiotemporal pattern of COVID clustering in North 24 Parganas, West Bengal, India

Debosmita Routh,Anu Rai,Gauri Sankar Bhunia 대한공간정보학회 2023 Spatial Information Research Vol.31 No.1

Many scholars and researchers have studied the CoVID-19 epidemic's spread using GIS technologies since it first appeared. The CoVID-19 pandemic is thought to be rife with unknowns, and many of them have a spatial component that makes the phenomenon understood as being spatially and possibly mappable. The majority of these efforts, though, have been made at the national, state, or district, levels. Very few studies primarily concentrate on the display of the CoVID-19 cluster at a local or neighborhood scale. From the perspective of micro-planning, analyzing the clustering, geographical direction, and heterogeneity of the CoVID-19 hotspots' spatial pattern is crucial specially when mass has returned to new normal living style. Using a case study on the North 24 Parganas of West Bengal, India, the most vulnerable district in West Bengal, we attempt to analyze the CoVID-19 diffusion at the block level in post-lockdown period. We assess the spatiotemporal distribution of CoVID-19 and map its hotspots based on the containment zones. This study demonstrates the patterns of geographical dispersion and the CoVID-19 pandemic spread in North 24 Parganas which is highly concentrated along the western boundaries of the state. We observed that the containment clusters of 2020 once more noted a higher density of CoVID cases in 2022 and validates the findings of the current study. It promises to corroborate the study into the geographic relation and spread of CoVID-19. By examining such spatial distribution patterns, the government might be able to track and predict the transmission of the infection in neighborhoods of blocks.

Investigations on Split-Source Inverter Based Shunt Active Power Filter Integrated Microgrid System for Improvement of Power Quality Issues

Barik Prasanta Kumar,Shankar Gauri,Sahoo Pradeepta Kumar 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

To meet the constantly rising energy demand, renewable energy sources are increasingly being used in power networks, transforming the traditional power distribution system into a microgrid (MG) based system. Simultaneously, the presence of nonlinear loads in the MG system may cause unwanted power quality (PQ) issues, which must be thoroughly addressed. The use of a shunt active power fi lter (SAPF) to mitigate PQ problems in a standalone MG system is discussed in this paper. SAPF performance must meet a number of requirements, including constant dc-link capacitor voltage, continuous input current fl ow, and lower switching loss, all of which are diffi cult to achieve with a traditional voltage source inverter (VSI). A new inverter named split source inverter (SSI) has been recently developed and has all the above features. In SSI, both the dc and ac sides are regulated using modulation index with the same control mechanism as that of normal VSI. The application of SSI with SAPF is yet to be explored in detail. As a result, a performance comparison of two inverters (traditional VSI and SSI) based SAPF with modifi ed synchronous reference frame technique for generation of reference current, adaptive hysteresis current controller for generation of switching pulse, and proportional-integral controller or fuzzy logic controller for dc-link voltage regulation has been investigated in this paper. Under ideal/non-ideal source conditions, the proposed SAPF outperforms other counterparts in terms of dc-link voltage regulation and mitigation of harmonics generated by various nonlinear loads.

Bactenecins : Potent Peptide Antibiotics for Prophyromonas gingivalis and Actinobacillus actinomycetemcomitans

Raj, Antony P.,Gauri,Edgerton, M. Korean Academy of Oral Biology and the UCLA Dental 1997 International Journal of Oral Biology Vol.22 No.2

Bactenecin 5, its fragments and bactenecin 7 were examined for their in vitro cidal activity against two oral pathogens, porphyromonas gingivalis and Actinobacillus actinomycetemcomitans. The two strains of porphyromonas gingivalis (W50 and 381) have been found to be highly sensitive to bactenecins. The Actinobacillus actinomycetemcomitans strains, Y4 and 67, were highly sensitive to bactenecins even at a concentration of nearly 0.2μm. The cidal activity of the longer fragments of bactenecin 5, BN22, and BC24 were comparable to the bactericidal activity of the whole molecule indicating that the cidal potency of bactenecin 5 can be retained with half of its size. Bactenecin 5 and bactenecin 7 have been found to elicit similar bactericidal activity suggesting that increasing the peptide size beyond 43 residues does not influence the cidal potency. The shorter N-terminal fragment (BN16) of bactenecin has been found to be less active than the longer fragments BN22 and BC24, suggesting that a minimum chain length of more than 20 residues may be necessary to elicit the potency of the whole molecule. However, the strains of porphyromonas gingivalis and Actinobacillus actinomycetemcomitans have been found to be highly sensitive (>75% loss in cell viability) to BN16 at the concentration of 10 and 3.2μm, respectively. The circular dichroism studies of bactenecin 7 suggest that it could exist as poly-L-proline Ⅱ like helix both in aqueous soloution and in lipid vesicles. Our results suggest that the fragments of bactenecins could serve as potent antibiotics for porphyromonas gingivalis and Actinobacillus actinomycetemcomitans.

Factors Associated with Tobacco Use in Students Attending Local Government Schools in Mumbai, India

Chatterjee, Nilesh,Todankar, Priyamvada,Mandal, Gauri,Gupte, Himanshu,Thawal, Vaibhav,Bhutia, Tshering,Choudhuri, Leni Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.12

Purpose: Factors associated with ever-use and differences between ever-users and non-users of tobacco among adolescent school students from low income families in Mumbai were assessed. Materials and Methods: A self-administered questionnaire, completed by 1918 students from grades 7, 8 and 9 in 12 schools managed by the city municipal corporation in July 2015, gathered data on socio-demographic characteristics, tobacco use and tobacco-related knowledge, attitudes and beliefs. Results: Although only 1% of respondents thought tobacco was cool, nearly 35% were unaware of associations between tobacco use and health problems. Male students were almost twice as likely (OR=2.5, P <= 0.05) to have ever used tobacco compared to females and Supari (areca nut) users were eight times more likely (OR=8.99, P < 0.001) than Supari non -users. Tobacco-users were more likely to agree with statements: 'People who use tobacco have more friends' (OR=2.8, P = 0.004), 'Smoking relieves stress' (OR=5.6, P = 0.002) and 'It is possible to purchase any tobacco product within 100 yards of school' (OR=10.8, P < 0.001). Conclusion: This study highlights the gains made by tobacco prevention campaigns in that almost all students did not consider tobacco as cool or a stress reliever. However, they still need education about health consequences of tobacco-use. In addition, Supari use has to be addressed in school-based tobacco prevention and cessation initiatives. Furthermore, programs must also address perceptions and norms related to peers and tobacco use and ensure active implementation of existing laws. Such integrated measures will help ensure tobacco-free spaces around schools.