• Title/Summary/Keyword: N region

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A Study on the electron energy diffusion function of the sulphur hexaflouride ($ SF_6$가스의 전자에너지 분포함수에 관한 연구)

  • 김상남;하성철
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.13 no.2
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    • pp.95-101
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    • 1999
  • The electron energy distributions function were analysed in sulIitur hexaflowide at E/N : 500~800(Td) for a case of non-equilibrium region in the nran electron energy. This papa- describes the electron transport characteristics in $ SF_6$ gas calculated for range of E/N values from 150~800(Td) by the Monte Carlo simulation and Boltzmann equation Irethod using a set of electron collision cross sectioos determined by the authors and the values of electron swarm parameters. The results gained that the value of an electron swarm parameter such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients agree with the experimental and theoretical for a range of E/N. The properties of electron avalanches in an electron energy non-equilibrium region.region.

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Effects of Current Spreading in GaN-based Light-emitting Diodes Using ITO Spreading Pad

  • Kim, Jang Hyun;Kim, Garam;Park, Euyhwan;Kang, Dong Hoon;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.1
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    • pp.114-121
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    • 2015
  • In conventional LEDs, a mesa-structure is usually used and it causes the current to be overcrowded in a specific region. We propose a novel structure of GaN-based LED to overcome this problem. In order to distribute the current in an active region, a spreading pad is inserted at the p-type region in the GaN based LED device. The inserted spreading pad helps the current flow because it is more conductive than the p-type GaN layer. By performing electrical and optical simulations, the effects of the spreading pad insertion are confirmed. The results of electrical simulation show that the current spreads more uniformly and more radiative recombination is produced as well. Moreover, from the optical simulation, it is revealed that the ITO is less absorptive material than p-GaN if the condition of specific wavelength sources is satisfied. Considering all of the results, we can conclude that the luminescent power is enhanced by the spreading pad.

A New Species of Chigger Mite (Acari: Trombiculidae) from Rodents in Southwest China

  • Ren, Tian-Guang;Guo, Xian-Guo;Jin, Dao-Chao;Wu, Dian;Fletcher, Quinn E.
    • Parasites, Hosts and Diseases
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    • v.52 no.1
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    • pp.63-67
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    • 2014
  • This paper describes a new species of chigger mite (Acari: Trombiculidae), Gahrliepia cangshanensis n. sp., from rodents in southwest China. The specimens were collected from Yunnan red-backed voles, Eothenomys miletus (Thomas, 1914), and a Chinese white-bellied rat, Niviventer confucianus (Milne-Edwards, 1871) in Yunnan Province. The new species is unique mainly in its number of dorsal setae (n=21), and it has the following features: fT (formula of palpotarsus)=4B (B=branched), fp (formula of palpal seta)=B/N/N/N/B (N=naked), a broad tongue-shaped scutum with an almost straight posterior margin, and 17 PPLs (posterior posterolateral seta) with a length of 36-43 ${\mu}m$. This chigger mite may also infect other rodent hosts and may be distributed in other localities.

Offsetting a Region Including Islands for Tool-Path Generation (공구 경로 생성을 위한 아일랜드를 포함하는 영역의 오프셋)

  • Park, Sang-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.12
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    • pp.2009-2018
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    • 2001
  • This paper presents a region offsetting algorithm for tool-path generation. The proposed region offsetting algorithm is developed by expanding the 'PWID offset algorithm [Choi and Park, 1999]'designed to offset a simple polygon. The PWID offset algorithm has three important steps; 1) remove 'local invalid ranges'by invoking a PWID test, 2) construct a raw offset owe and 3) remove 'global invalid ranges'by finding self-intersections of the raw offset cure. To develop a region offsetting algorithm, we modified the PWID offset algorithm by expanding the concept of the 'global invalid range'in the third step. The time complexity of the proposed algorithm is approximately Ο(n), where n is the number of points, and it is free of numerical errors for practical purposes. The proposed algorithm has been implemented and tested with various real regions obtained by intersecting a sculptured surface with a plane.

A Study on the Low Temperature Fracture Toughness of Ion-nitrided Ni-Cr-Mo Steel (이온 실화처리한 Ni-Cr-Mo강의 저온파괴인성에 관한 연구)

  • 오세욱;윤한기;문인철
    • Journal of Ocean Engineering and Technology
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    • v.1 no.2
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    • pp.101-112
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    • 1987
  • Fracture toughness characterization in the transition region is examined for heat-treated and ionnitrided Ni-Cr-Mo steel. After heat treatment for the specimens of Ni-Cr-Mo steel, organizations of specimens-specimens which are heat-treated and ion-nitrided for 4 hours at 500 .deg. C and 5 torr in 25%N/dub 2/-75%H/sub 2/mixed gas-, hardness variety, and X-ray diffraction pattern of the ion-nitriding compound layer are observed. Fracture toughenss test of unloading compliance method were conducted over the regions from room trmperature to -70.deg. C. The compound layer was consisted of r'=Fe/sub 4/N phase and ion-nitrided layer's depth was 200mm from surface. The transition regions of heat-treated and ion-nitrided specimens were about -30.deg. C and -50.deg. C, respectively. The transition region of ion-nitrided specimens is estimated less than that of heat-treated one, and this is the effect of ion-nitriding.

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Secondary Structure for RNA Aptamers Binding to Guanine-Rich Sequence in the 5'-UTR RNA of N-Ras Oncogene

  • Cho, Bongrae
    • Journal of the Korean Chemical Society
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    • v.65 no.2
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    • pp.121-124
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    • 2021
  • RNA molecules which bind to the G-rich sequence in the 5'-UTR RNA which plays an important role in expression of N-ras, were selected. The secondary structures of five selected RNA aptamers including primer sequence were found by the CLC RNA workbench ver. 4.2 program (www.clcbio.com) and investigated with RNA structural probes such as RNase T1 which has specificity for a G in single-stranded region, RNase V1 specific for double strand and nuclease S1 specific for single strand. The generalized secondary structure model was proposed and characterized. It was composed of a central long double strand region flanked by single strand region at both end sides. The double strand region had an internal single-strand region and bulges. The single strand loop in the right side was composed of four or five nucleotides.

Backbone assignment of the intrinsically disordered N-terminal region of Bloom syndrome protein

  • Min June Yang;Chin-Ju Park
    • Journal of the Korean Magnetic Resonance Society
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    • v.27 no.3
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    • pp.17-22
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    • 2023
  • Bloom syndrome protein (BLM) is a pivotal RecQ helicase necessary for genetic stability through DNA repair processes. Our investigation focuses on the N-terminal region of BLM, which has been considered as an intrinsically disordered region (IDR). This IDR plays a critical role in DNA metabolism by interacting with other proteins. In this study, we performed triple resonance experiments of BLM220-300 and presented the backbone chemical shifts. The secondary structure prediction based on chemical shifts of the backbone atoms shows the region is disordered. Our data could help further interaction studies between BLM220-300 and its binding partners using NMR.

Interaction of XRCC1 and XPD Gene Polymorphisms with Lifestyle and Environmental Factors Regarding Susceptibility to Lung Cancer in a High Incidence Population in North East India

  • Saikia, Bhaskar Jyoti;Phukan, Rup Kumar;Sharma, Santanu Kumar;Sekhon, Gaganpreet Singh;Mahanta, Jagadish
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.1993-1999
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    • 2014
  • Background: This study aimed to explore the role of XRCC1 (Arg399Gln) and XPD (Lys751Gln) gene polymorphisms, lifestyle and environmental factors as well as their possible interactions in propensity to develop lung cancer in a population with high incidence from North East India. Materials and Methods: A total of 272 lung cancer cases and 544 controls were collected and XRCC1 (Arg399Gln) and XPD (Lys751Gln) genotypes were analyzed using a polymerase chain reaction based restriction fragment length polymorphism assay. Conditional multiple logistic regression analysis was used to calculate adjusted odds ratios and 95% confidence intervals after adjusting for confounding factors. Results: The combined Gln/Gln genotype of XRCC1 and XPD genes (OR=2.78, CI=1.05-7.38; p=0.040) was significantly associated with increased risk for lung cancer. Interaction of XRCC1Gln/Gln genotype with exposure of wood combustion (OR=2.56, CI=1.16-5.66; p=0.020), exposure of cooking oil fumes (OR=3.45, CI=1.39-8.58; p=0.008) and tobacco smoking (OR=2.54, CI=1.21-5.32; p=0.014) and interaction of XPD with betel quid chewing (OR=2.31, CI=1.23-4.32; p=0.009) and tobacco smoking (OR=2.13, CI=1.12-4.05; p=0.022) were found to be significantly associated with increased risk for lung cancer. Conclusions: Gln/Gln alleles of both XRCC1 and XPD genes appear to amplify the effects of household exposure, smoking and betel quid chewing on lung cancer risk in the study population.

A TEM Study on Growth Characteristics of GaN on Si(111) Substrate using MOCVD (Si(111) 기판 위에 MOCVD 법으로 성장시킨 GaN의 성장 특성에 관한 TEM 분석)

  • 신희연;정성훈;유지범;서수정;양철웅
    • Journal of the Korean institute of surface engineering
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    • v.36 no.2
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    • pp.135-140
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    • 2003
  • The difference in lattice parameter and thermal expansion coefficient between GaN and Si which results in many defects into the grown GaN is larger than that between GaN and sapphire. In order to obtain high quality GaN films on Si substrate, it is essential to understand growth characteristics of GaN. In this study, GaN layers were grown on Si(111) substrates by MOCVD at three different GaN growth temperatures ($900^{\circ}C$, $1,000^{\circ}C$ and $1,100^{\circ}C$), using AlN and LT-GaN buffer layers. Using TEM, we carried out the comparative investigation of growth characteristics of GaN by characterizing lattice coherency, crystallinity, orientation relationship and defects formed (transition region, stacking fault, dislocation, etc). The localized region with high defect density was formed due to the lattice mismatch between AlN buffer layer and GaN. As the growth temperature of GaN increases, the defect density and surface roughness of GaN are decreased. In the case of GaN grown at $1,100^{\circ}$, growth thickness is decreased, and columns with out-plane misorientation are formed.

Multi-level Vector Error Diffusion Based on Primary Color Selection Considering Lightness (휘도를 고려한 기준색 선택 기반의 다단계 벡터 오차 확산법)

  • 박태용;조양호;이명영;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.77-85
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    • 2004
  • This paper proposes a multi-level vector error diffusion method using 64 primary colors to improve color impulse artifact in bright region. Vector error diffusion method causes color impulse artifact in bright region because we only use the Euclidean distance measure in quantization process. In order to reduce this artifact, the proposed method divides input color into chromatic color and achromatic color according to chroma value. In the case of chromatic color, input color is classified into bright region, middle bright region, and dark region according to lightness value. N candidate primary color is organized using lightness difference between input vector and 60 chromatic primary color vector in the case of bright region. Then, primary color with minimum vector norm between input vector and N candidate primary color in addition to 4 achromatic primary colors is selected as output color. As a result of experiments, the proposed method showed visually pleasing halftone output.