• Title/Summary/Keyword: Ar

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Effects of Ar/He Dilution on Combustion Characteristics in DI Diesel Engine using Turbocharging and EGR (터보과급 및 EGR을 사용하는 직접분사식 디젤엔진의 연소특성에 미치는 Ar과 He첨가의 영향)

  • 권영동;김용모;박신배;백현종;이동권
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.5
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    • pp.140-156
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    • 1997
  • The combustion characteristics of DI Diesel engine using turbocharging and EGR are numerically studied. Computations are carried out for the wide range of trubochyarged pressures, EGR ratios, and Ar/He dilution. Numerical results indicate that the Ar/He dilution in the intake gas significantly influence the engine performance, the spray combustion process, and the pollutant formation.

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ECR plasma pretreatment for Ru nucleation enhancement on the TiN film (Ru 핵생성에 대한 ECR plasma 전처리 세정의 효과)

  • 엄태종;신경철;최균석;이종무
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.120-120
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    • 2003
  • MOCVD법으로 TiN 표면에 Ru을 증착함에 있어서 Ru의 핵생성을 고양시키기 위한 ECR plasma 전처리 세정이 필요하다. 본 연구에서는 Ru 증착시 ECR $H_2O$$_2$, AE Plasma 전처리 세정 효과를 SEM, AES, XRD로 분석하였다. Ru의 핵생성은 ECR H$_2$, Ar Plasma의 노출시간이 증가할수록 향상된 반면, ECR $O_2$ plasma의 경우 노출시간이 증가할수록 핵생성 효과는 감소하였다. H$_2$ plasma 내의 H$_2$ion은 Ti와 NH$_3$를 형성하기 위해서 TiN과 반응하여 TiN을 Ti로 개질 시켰으며, Ar plasma 전처리 세정하는 동안 Ar plasma 내의 Ar ion은 TiN 또는 TiON 표면의 질소와 산소원자를 제거하는 효과를 나타내었다. 그 결과 TiN 표면상에서도 Ru의 핵생성이 쉽게 이루어졌으며 H$_2$, Ar ECR Plasma 전처리 세정에서 RU 핵생성이 향상되는 결과를 얻었다. 세 종류의 plasma중에서 Ar ECR plasma로 전처리 세정한 경우에 가장 높은 Ru 핵생성 밀도를 얻을 수 있었다.

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Mitigating Antibiotic Resistance at the Livestock-Environment Interface: A Review

  • Ma, Zhengxin;Lee, Shinyoung;Jeong, K. Casey
    • Journal of Microbiology and Biotechnology
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    • v.29 no.11
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    • pp.1683-1692
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    • 2019
  • The rise of antimicrobial resistance (AR) is a major threat to global health. The food animal industry contributes to the increasing occurrence of AR. Multiple factors can affect the occurrence and dissemination of AR in the animal industry, including antibiotic use and farm management. Many studies have focused on how the use of antibiotics in food-producing animals has led to the development of AR. However, a few effective mitigating strategies for AR have been developed in food-producing animals, especially those exposed to the environment. The aim of this review is to summarize potential strategies applicable for mitigating AR at the environment-livestock interface.

Etching Properties of $RuO_2$Thin Film in Inductively Coupled Plasma (ICP에 의한 $RuO_2$박막의 식각 특성)

  • 김창일;김동표
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.863-865
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    • 2001
  • In this study, RuO$_2$thin films were etched in inductively coupled $O_2$plasma. Etching characteristics of RuO$_2$thin films including etch rate and selectivity were evaluated as a function of rf power in $O_2$plasma and gas mixing ratio in $O_2$/Ar plasma. In $O_2$ plasma, the etch rate of RuO$_2$thin film increases as rf power increases. In $O_2$/Ar plasma, the etch rate of RuO$_2$thin film increases up to 10% Ar, but decrease with furthermore increasing Ar mixing ratio. The enhanced etch rate can be obtained with increasing rf power and small addition of Ar gas.

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A study of surface states in Ar plasma exposed InP measured by photoreflectance (Ar 플라즈마가 조사된 InP의 Photoreflectance 방법에 의한 표면상태 연구)

  • 김종수;이정열;손정식;배인호;김인수;김대년
    • Journal of the Korean Vacuum Society
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    • v.8 no.4A
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    • pp.403-409
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    • 1999
  • The surface state of Ar plasma-exposed Fe doped SI-InP have been investigated by photoreflectance (PR). From Ar plasma-exposed InP with 30 W for 10sec, the PR signals include a peak $(E_{Ar})$ that is located at 1.336 eV. We think that this peak was originated shallow level related to $V_In-V_P$. And we compared this level with the level obtained by surface photovoltage spectroscopy (SPV) measurement. The result of the PR agrees well with that from SPV. Additionally, Ar plasma induced phosphorus vacancy is related to shallow level. Therefore, the change of surface electric field are attributed to the shallow level. This level is caused by the existence of phsophorus vacancy on InP surface.

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Electrical Properties of SBT Thin Films after Etching in Cl$_2$/Ar Inductively Coupled Plasma (Ar/Cl$_2$ 유도결합플라츠마 식각 후 SBT 박막의 전기적 특성)

  • 이철인;권동표;깅창일
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.58-61
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    • 2002
  • SBT thin films were etched at different content of Cl$_2$in Cl$_2$/Ar plasma. We obtained the maximum etch rate of 883 ${\AA}$/min at Cl$_2$(20%)/Ar(80%). As Cl$_2$ gas increased in Cl$_2$/Ar plasma, the etch rate decreased. The maximum etch rate may be explained by variation of volume density for Cl atoms and by the concurrence of two etching mechanisms such as physical sputtering and chemical reaction with formation of low-volatile products, which can be desorbed only by ion bombardment. The variation of volume density for Cl, F and Ar atoms and ion current density were measured by the optical emission spectroscopy and Langmuir probe. To evaluate the physical damage due to plasma, X-ray diffraction and atomic force microscopy analysis carried out. After etching process, P-E hysteresis loops were measured by ferroelectric workstation.

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Analysis on the improvement of Luminous Efficiency by Adding a small amount of Ar Gas in plasma display (PDP에서의 Ar Gas첨가시 효율 개선 경로에 관한 분석)

  • Min, Byeong-Guk;Park, Heon-Geon;Lee, Seok-Hyeon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.6
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    • pp.483-488
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    • 1999
  • The optimal mixing condition of four components gas(Ne,Xe,He,Ar) in PDPs was caculated by a numerical simulation method. The dominated reactions in which $Xe^*(^3P_1)$ is produced and decays were investigated in three components gas (Ne,Xe,He) and our new components gas (Ne,Xe,He,Ar). A peak point of $Xe^*$ density appears in the range of 0.1% to 2% of Ar mixture ratio. The results of simulation show that the direct exitation of Xe by electrons has the greatest influence on the inceasing $Xe^*$ density in both gas mixtures.

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Rat Lens Aldose Reductase Inhibitory Activities of Cissus assamica var. pilosissima and Syzygium oblatum

  • Lee, Ki Ho;Lee, Dong Gu;Lee, Sangwoo;Li, Wanyi;Lee, Sanghyun
    • Natural Product Sciences
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    • v.19 no.4
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    • pp.275-280
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    • 2013
  • Aldose reductase (AR) has been shown to play an important role in the development of diabetic complications. To search for AR inhibitors from Chinese plants, the ethanol extracts of Chinese plants was tested against an inhibition of rat lens AR in vitro. Among Chinese plants tested, Cissus assamica var. pilosissima and Syzygium oblatum showed highest inhibition of AR ($IC_{50}$ values, 0.71 and 0.79 ${\mu}g/ml$, respectively). Cissus assamica var. pilosissima and Syzygium oblatum showed more potent inhibitory activity against AR than the positive control, TMG. Consequently, C. assamica var. pilosissima and S. oblatum have a possibility of new natural resources for the development of AR inhibitor for the prevention of diabetic complications.

The effect of Astragali Radix Ethanol extract on Murine CD4 T cells′ Cytokine Profiles in vitro

  • Hee Kang;Bae Hyun Su;Ahn Kyoo Seok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.5
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    • pp.1330-1334
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    • 2003
  • Astragali Radix(AR), one of the strong tonic herbs, is known to improve immunological responses in mice and human. In this study, AR's ai-reinforcing effect was examined in the context of CD4/sup +/ T cells' TCR/CD3 induced activation responses. In order to evaluate the direct effect of AR on helper T cells, CD4/sup +/ T cells are isolated using magnetic bead and their proliferation and CD69 expression in AR treated medium were assessed with anti-CD3/anti-CD28 activation for 48h. CD4 T cells' proliferation was slightly increased but there was little effect on CD69 expression. RT PCR and ELISA equally demonstrated that IL-2 and IL-4 production was increased but IFN-ν was down-regulated. This shows AR ethanol extract favors Th2 cytokine profile under neutral conditions.

Consideration of Augmented Media Service using JPEG AR Standard (JPEG AR 표준을 이용한 증강 미디어 서비스 고찰)

  • Kim, Min-Uk;Yoon, Kyoungro
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2014.11a
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    • pp.86-87
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    • 2014
  • JPEG 표준화 기구에서 표준화 중인 JPEG AR 표준은 증강 현실 응용을 구성하는 요소간의 인터페이스를 표준화하고 있다. 본 논문에서는 증강 현실 기술을 기반으로 기존 미디어에 새롭게 가상 정보를 추가한 증강 미디어 서비스(개인화 서비스, 증강 방송, 사물 인터넷과 결합한 증강 미디어 서비스)를 JPEG AR 표준 측면에서 고찰하고, 이들 서비스를 위한 JPEG AR 표준의 추가 요소를 살펴본다. 세 가지 서비스를 구체적으로 살펴본바, JPEG AR 표준은 기존의 증강 현실 표준보다 유연한 시스템 구조를 갖고 있어 다른 분야 또는 시스템과의 연결이 용이하고, 이에 따라 증강 미디어 서비스뿐 아니라 새로운 융 복합 기술을 창출하는데 일조할 것으로 기대된다.

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