• 제목/요약/키워드: active pressure

검색결과 954건 처리시간 0.026초

Investigation of Effective Contact Resistance of ZTO-Based Thin Film Transistors

  • 강유진;한동석;박재형;문대용;신소라;박종완
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.543-543
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    • 2013
  • Thin-film transistors (TFTs) based on oxide semiconductors have been regarded as promising alternatives for conventional amorphous and polycrystalline silicon TFTs. Oxide TFTs have several advantages, such as low temperature processing, transparency and high field-effect mobility. Lots of oxide semiconductors for example ZnO, SnO2, In2O3, InZnO, ZnSnO, and InGaZnO etc. have been researched. Particularly, zinc-tin oxide (ZTO) is suitable for channel layer of oxide TFTs having a high mobility that Sn in ZTO can improve the carrier transport by overlapping orbital. However, some issues related to the ZTO TFT electrical performance still remain to be resolved, such as obtaining good electrical contact between source/drain (S/D) electrodes and active channel layer. In this study, the bottom-gate type ZTO TFTs with staggered structure were prepared. Thin films of ZTO (40 nm thick) were deposited by DC magnetron sputtering and performed at room temperature in an Ar atmosphere with an oxygen partial pressure of 10%. After annealing the thin films of ZTO at $400^{\circ}C$ or an hour, Cu, Mo, ITO and Ti electrodes were used for the S/D electrodes. Cu, Mo, ITO and Ti (200 nm thick) were also deposited by DC magnetron sputtering at room temperature. The channel layer and S/D electrodes were defined using a lift-off process which resulted in a fixed width W of 100 ${\mu}m$ and channel length L varied from 10 to 50 ${\mu}m$. The TFT source/drain series resistance, the intrinsic mobility (${\mu}i$), and intrinsic threshold voltage (Vi) were extracted by transmission line method (TLM) using a series of TFTs with different channel lengths. And the performances of ZTO TFTs were measured by using HP 4145B semiconductor analyzer. The results showed that the Cu S/D electrodes had a high intrinsic field effect mobility and a low effective contact resistance compared to other electrodes such as Mo, ITO and Ti.

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정적연소기를 이용한 합성가스의 가연한계 및 연소특성에 관한 실험적 연구 (An Experimental Study on Flammability Limits and Combustion Characteristics of Synthetic Gas in a Constant Combustion Chamber)

  • 조용석;이성욱;원상연;박영준;김득상
    • 한국자동차공학회논문집
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    • 제16권1호
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    • pp.14-21
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    • 2008
  • Synthetic gas is defined as reformed gas from hydrocarbon-based fuel and the major chemical species of the synthetic gas are $H_2$, CO and $N_2$. Among them, hydrogen from synthetic gas is very useful species in chemical process such as combustion. It is a main reason that many studies have been performed to develop an effective reforming device. Furthermore, other technologies have been studied for synthetic gas application, such as the ESGI(Exhaust Synthetic Gas Injection) technology. ESGI injects and burns synthetic gas in the exhaust pipe so that heat from hydrogen combustion helps fast warmup of the close-coupled catalyst and reduction of harmful emissions. However, it is very hard to understand combustion characteristic of hydrogen under low oxygen environment and complicated variation in chemical species in exhaust gas. This study focuses on the characteristics of hydrogen combustion under ESGI operating conditions using a CVC(Constant Volume Chamber). Measurements of pressure variation and flame speed have been performed for various oxygen and hydrogen concentrations. Results have been analyzed to understand ignition and combustion characteristics of hydrogen under lower oxygen conditions. The CVC experiments showed that under lower oxygen concentration, amount of active chemicals in the combustion chamber was a crucial factor to influence hydrogen combustion as well as hydrogen/oxygen ratio. It is also found that increase in volume fraction of oxygen is effective for the fast and stable burning of hydrogen by virtue of increase in flame speed.

Episodic Particulate Sulfate and Sulfur Dioxide on the Southwestern Japan Coast in March and April 2010

  • Nagatani, Tetsuji;Yamada, Maromu;Kojima, Tomoko;Zhang, Daizhou
    • Asian Journal of Atmospheric Environment
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    • 제6권1호
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    • pp.41-52
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    • 2012
  • Particulate sulfate in $PM_{2.5}$, sulfur dioxide ($SO_2$) and size-segregated aerosol particle number concentrations were measured at a site ($32^{\circ}19'N$, $129^{\circ}59'E$) on the southwestern Japan coast from 5 March to 10 April, 2010. Results show frequent episodic increases of sulfate and $SO_2$. Compared to the average concentration of sulfate $4.4{\pm}2.7\;{\mu}g\;m^{-3}$ in the whole observation period, episodic sulfate reached $10.5-20.1\;{\mu}g\;m^{-3}$. The variation of sulfate always synchronized with aerosol particles in the size range of $0.1-0.5 {\mu}m$, indicating the episodic sulfate was a consequence of the increase of the sub-micron particles. $SO_2$ did not have remarkable increase in any episodes of sulfate increase. During the passage of low pressure systems which loaded Asian dust in postfrontal air, concentrated sulfate appeared right behind the front but before dust arrival, suggesting the dominance of dust-free particulate sulfate. Weather and backward trajectory analyses revealed that air parcels with high sulfate passed eastern and northeastern China or Korean peninsula before arriving at the site. In contrast, those with high $SO_2$ passed an active volcano, Mt. Sakurajima, about 100 km in the south, suggesting the $SO_2$ was more likely from the volcanic emission. The ratio of sulfate to total sulfur compounds $({SO_4}^{2-})/({SO_4}^{2-}+SO_2)$ was 0.31-0.89 in continentally originated air while was 0.25-0.43 in the air having passed the volcano, showing more efficient conversions of $SO_2$ to sulfate in the air from the continent. The close dependence of the conversion on humidity in the continentally originated air was confirmed.

다목적 홀에서의 프론트필 스피커의 필요성 (The need of Front-fill Speaker in the Multipurpose Hall)

  • 송덕근;강준상;노정규;이선희
    • 한국위성정보통신학회논문지
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    • 제8권4호
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    • pp.43-46
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    • 2013
  • 영상을 적극적으로 사용하는 종교 시설과 같은 장소에서는 스크린 높이에 따라 메인 스피커의 높이가 결정된다. 이로 인해 '음상불일치'와 '저음부스팅'과 같은 음향 장애 요인이 발생하여 시각적으로 좋은 자리인 앞 좌석이 음향적으로는 좋지 않은 장소가 되고 만다. 이러한 음향적 장애를 최소화하기 위해서는 프론트필(Front-fill) 스피커를 적극적으로 도입할 필요가 있으며, 스크린 때문에 높아진 메인 스피커와의 거리 및 음압 차이에 따라 적합한 용량을 결정해야 한다. 프론트필 스피커를 적극적으로 사용하여 음상일치(音像一致)를 구현함으로써 음의 집중도를 높이고, 고음(高音) 유입이 상대적으로 부족한 앞좌석에 중고음을 보강하여 주파수 응답을 고르게 구현할 수 있다. 멀티미디어 환경에서 주요 좌석인 앞쪽 열에 메인 스피커의 부족한 부분을 보완하여 더 쾌적한 음향 환경을 구현하기 위해 프론트필 스피커를 적극적으로 도입할 필요가 있으며, 이에 대한 구체적인 기준안 제시가 필요하다.

Identification of Anti-Cancer Targets of Eco-Friendly Waste Punica granatum Peel by Dual Reverse Virtual Screening and Binding Analysis

  • Usha, Talambedu;Goyal, Arvind Kumar;Lubna, Syed;Prashanth, H.P.;Mohan, T. Madhan;Pande, Veena;Middha, Sushil Kumar
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권23호
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    • pp.10345-10350
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    • 2015
  • Background: Punica granatum (family: Lythraceae) is mainly found in Iran, which is considered to be its primary centre of origin. Studies on pomegranate peel have revealed antioxidant, anti-inflammatory, anti-angiogenesis activities, with prevention of premature aging and reducing inflammation. In addition to this it is also useful in treating various diseases like diabetes, maintaining blood pressure and treatment of neoplasms such as prostate and breast cancer. Objectives: In this study we identified anti-cancer targets of active compounds like corilagin (tannins), quercetin (flavonoids) and pseudopelletierine (alkaloids) present in pomegranate peel by employing dual reverse screening and binding analysis. Materials and Methods: The potent targets of the pomegranate peel were annotated by the PharmMapper and ReverseScreen 3D, then compared with targets identified from different Bioassay databases (NPACT and HIT's). Docking was then further employed using AutoDock pyrx and validated through discovery studio for studying molecular interactions. Results: A number of potent anti-cancerous targets were attained from the PharmMapper server according to their fit score and from ReverseScreen 3D server according to decreasing 3D scores. Conclusion: The identified targets now need to be further validated through in vitro and in vivo studies.

증기발생기 전열관 다중파단-피동보조급수냉각계통 사고 실험 기반 안전해석코드 SPACE 검증 (Verification of SPACE Code with MSGTR-PAFS Accident Experiment)

  • 남경호;김태우
    • 한국안전학회지
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    • 제35권4호
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    • pp.84-91
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    • 2020
  • The Korean nuclear industry developed the SPACE (Safety and Performance Analysis Code for nuclear power plants) code and this code adpots two-phase flows, two-fluid, three-field models which are comprised of gas, continuous liquid and droplet fields and has a capability to simulate three-dimensional model. According to the revised law by the Nuclear Safety and Security Commission (NSSC) in Korea, the multiple failure accidents that must be considered for accident management plan of nuclear power plant was determined based on the lessons learned from the Fukushima accident. Generally, to improve the reliability of the calculation results of a safety analysis code, verification work for separate and integral effect experiments is required. In this reason, the goal of this work is to verify calculation capability of SPACE code for multiple failure accident. For this purpose, it was selected the experiment which was conducted to simulate a Multiple Steam Generator Tube Rupture(MSGTR) accident with Passive Auxiliary Feedwater System(PAFS) operation by Korea Atomic Energy Research Institute (KAERI) and focused that the comparison between the experiment results and code calculation results to verify the performance of the SPACE code. The MSGR accident has a unique feature of the penetration of the barrier between the Reactor Coolant System (RCS) and the secondary system resulting from multiple failure of steam generator U-tubes. The PAFS is one of the advanced safety features with passive cooling system to replace a conventional active auxiliary feedwater system. This system is passively capable of condensing steam generated in steam generator and feeding the condensed water to the steam generator by gravity. As the results of overall system transient response using SPACE code showed similar trends with the experimental results such as the system pressure, mass flow rate, and collapsed water level in component. In conclusion, it could be concluded that the SPACE code has sufficient capability to simulate a MSGTR accident.

낙법(烙法)에 관한 중의(中醫) 논문 고찰 (A Review of the TCM Articles about Cauterization Treatment)

  • 장호정;이현주;서형식
    • 한방안이비인후피부과학회지
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    • 제31권3호
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    • pp.60-66
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    • 2018
  • Objectives : The purpose of this study is to review the chinese published papers on cauterization of traditional chinese medicine. Methods : We searched chinese published papers from 1958 until May 2017 via CNKI(China National Knowledge Infrastructure) with the keyword "cauterization". We analyzed the studies covered cauterization medical treatment, and classified them by 5 categories including periods, type of study, treatment site, experiment target site, and cauterizing method. Results : We reviewed 112 chinese papers which include 10 Original articles, 43 Review articles, and 59 Case reports. Examining yearly distributions, we can see that research on cauterization is becoming more active than in the past. In classification of 93 clinical studies by treatment site, the number of research on Tonsillitis accounts for almost half(43 studies), followed by Sore throat(14 studies). Among 10 experimental studies, Eye is the most frequently targeted organ which was used to study high intra-ocular pressure(5 studies), and retinal ganglion cell(2 studies). Lastly, there are various methods of cauterization used in papers: Branding iron(54 studies), and Red-hot needle(24 studies) are two major heating methods. Conclusions : This analysis shows that studies on the application of cauterization have been actively conducted in China these days. Furthermore, up-to-date cauterizing methods have been developed such as electric type and microwave type beyond traditional ways. We expect this article will encourage further research on cauterization in order to apply it to a variety of diseases. Then, it could become one of new effective medical treatments in Korean medicine.

플라즈마 변수에 의한 불순물주입 다결정실리콘 박막의 식각율 변화 (Etch Rate Dependence of Differently Doped Poly-Si Films on the Plasma Parameters)

  • 박성호;김윤태;김진섭;김보우;마동성
    • 대한전자공학회논문지
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    • 제25권11호
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    • pp.1342-1349
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    • 1988
  • 플리즈마 변수로서 가스조성과 압력 및 RF 전력이 인 및 붕소가 각각 다른 양으로 주입된 다결정 실리콘의 식각율 변화에 미치는 영향을 고찰하였다. $POCl_3$에 의해 인이 주입된 경우, 염소조성보다 불소조성이 많은 영역, 즉 $Cl_2$$SF_4$의 비가 17대 33일 때, 가장 큰 비등방성과 가장 작은 선폭손실을 달성하였다. 플라즈마 조건에 관계없이 주입된 불순물 농도의 증가에 다라, 인이 주입된 경우는 식각율이 증가하였고, 붕소가 주입된 경우는 식각율이 반대로 감소하였다. 또한, 급속 열처리에 의한 활성화 시간의 함수로서 인이 주입된 다결정실리콘의 식각율변화를 측정한 결과, 도우핑 농도뿐 아니라 활성화된 운반자, 즉 전자의 농도가 그 식각율 증가에 중요한 역할을 한다는 것을 확인하였다.

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돌봄상황에서 신체적 접촉의 특성에 관한 연구 (The Study on the Characteristic of Physical Touch in Caring Situation)

  • 장성옥
    • 기본간호학회지
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    • 제2권2호
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    • pp.183-197
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    • 1995
  • This study was performed to investigate the characteristic of physical touch in caring situation. The subjects of this study were adults in caring situation, therefore they were composed of 7 patients, 6 nurses, 3 doctors, 3 pharmacologists, 3 men in paramedicine area, 3 nursing educators and 13 normal general adults. The datas were gathered through nonstructured questionaire from June, 20th to September, 15th in 1995. The datas were subjects' descriptions about the intention, perception, and form of physical touch in caring situation and analysed by content analysis. The results as follow : The datas were divided into four areas. There were the situation being necessiated the physical touch, meaning of physical touch, form of physical touch and perception about physical touch in caring situation. The situation being necessiated physical touch were the situation that required physical treatment, to deliver the active expression of concern about the patients, to determine the treatment due to the identification of physical condition of patients and to induce the psychological eqilibrium into patient's mind. The meanings of physical touch in caring situation were - Good meanings that intention is to encourage, to be have hope about health and to deliver the affection willing to help patient. - therapeutic methods that were to facillitate the circulation of blood, to reduce the pain perception and to facillitate the circulation of qi. - interpersonal affectionate relation that the intentions were to deliver the understanding of patient's pain, were to delivery the meaning to the patient not be alone. The forms of physical touch in caring situation were none invasive forms just like laying hands on hand, head, shoulder, gentle knocking on the shoulder or back, massage of legs and back and finger pressure on acupuncture points. The perception of physical touch in caring situation divided into two parts. In family, the perceptions of physical touch in caring situation were to promote health status because physical touch induce the psychological peace, and to evoke the importance of relationship among family members. In relation with care giver, perception of physical touch in caring situation were inevitable process in treatment, and to deliver the trust and concern about patients.

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광자기 디스크의 기록 및 자기적 특성에 산소가 미치는 영향 (Effect of Oxygen on the Magnetic and Recording Characteristics of Magneto-Optical Disk)

  • 최건
    • 한국자기학회지
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    • 제3권3호
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    • pp.229-233
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    • 1993
  • 광자기 디스크의 제조시 기록막내부의 산소함량에 따른 기록 및 자기적 특성의 변화를 연구하였다. 기록막내의 산소함량 변화는 반응성 스퍼터링에 의해 조절하였으며 스퍼터링 전과정 동안 산소의 거동을 in-situ 잔류가스분석기로 조사하였다. 산소함량의 증가에 따라 보자력은 감 소하였으나 수직이방성 및 수직 각형비등은 변화하지 않았다. 대부분의 첨가된 산소는 스퍼터링 과정중 소모되어 Tb원자와 안정한 산화물을 형성하여 자기적 조성의 변화를 초래하였지만 임계기 록크기와 임계외부자계크기에만 약간의 변화를 가져왔을 뿐 디스크의 기록신호잡음비에는 별로 영향을 미치지 않았다. 또한 디스크의 신뢰도면에서도 크게 감소하지 않았다.

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