• 제목/요약/키워드: Atmospheric physics

검색결과 274건 처리시간 0.06초

Refined numerical simulation in wind resource assessment

  • Cheng, Xue-Ling;Li, Jun;Hu, Fei;Xu, Jingjing;Zhu, Rong
    • Wind and Structures
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    • 제20권1호
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    • pp.59-74
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    • 2015
  • A coupled model system for Wind Resource Assessment (WRA) was studied. Using a mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, global-scale data were downscaled to the inner nested grid scale (typically a few kilometers), and then through the coupling Computational Fluid Dynamics (CFD) mode, FLUENT. High-resolution results (50 m in the horizontal direction; 10 m in the vertical direction below 150 m) of the wind speed distribution data and ultimately refined wind farm information, were obtained. The refined WRF/FLUENT system was then applied to assess the wind resource over complex terrain in the northern Poyang Lake region. The results showed that the approach is viable for the assessment of wind energy.

Analysis of Single Crystal Silicon Solar Cell Doped by Using Atmospheric Pressure Plasma

  • Cho, I-Hyun;Yun, Myoung-Soo;Son, Chan-Hee;Jo, Tae-Hoon;Kim, Dong-Hae;Seo, Il-Won;Roh, Jun-Hyoung;Lee, Jin-Young;Jeon, Bu-Il;Choi, Eun-Ha;Cho, Guang-Sup;Kwon, Gi-Chung
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.357-357
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    • 2012
  • The doping process of the solar cell has been used by furnace or laser. But these equipment are so expensive as well as those need high maintenance costs and production costs. The atmospheric pressure plasma doping process can enable to the cost reduction. Moreover the atmospheric pressure plasma can do the selective doping, this means is that the atmospheric pressure plasma regulates the junction depth and doping concentration. In this study, we analysis the atmospheric pressure plasma doping compared to the conventional furnace doping. the single crystal silicon wafer doped with dopant forms a P-N junction by using the atmospheric pressure plasma. We use a P type wafer and it is doped by controlling the plasma process time and concentration of dopant and plasma intensity. We measure the wafer's doping concentration and depth by using Secondary Ion Mass Spectrometry (SIMS), and we use the Hall measurement because of investigating the carrier concentration and sheet resistance. We also analysis the composed element of the surface structure by using X-ray photoelectron spectroscopy (XPS), and we confirm the structure of the doped section by using Scanning electron microscope (SEM), we also generally grasp the carrier life time through using microwave detected photoconductive decay (u-PCD). As the result of experiment, we confirm that the electrical character of the atmospheric pressure plasma doping is similar with the electrical character of the conventional furnace doping.

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Determination of Urban Surface Aerodynamic Characteristics Using Marquardt Method

  • Zhang, Ning;Jiang, Weimei;Gao, Zhiqiu;Hu, Fei;Peng, Zhen
    • Wind and Structures
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    • 제12권3호
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    • pp.281-283
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    • 2009
  • Marquardt method is used to estimate the aerodynamic parameters in urban area of Beijing City, China, including displacement length (d), roughness length ($z_0$) and friction velocity (u*) and drag coefficient. The surface drag coefficient defined as the ratio between friction velocity and mean wind speed is 0.125 in our research, which is close to typical urban area value. The averaged d and $z_0$ are 1.2 m and 7.6 m. d and $z_0$ change with direction because of the surface heterogeneity over urban surface and reach their maximum values at S-SW sector, this tendency agrees with the surface rough element distribution around the observation tower.

펄스변조의 듀티비 변경에 따른 DBD 대기압 플라즈마 특성 연구 (Study on the Atmospheric Plasma Characteristics of Dielectric Barrier Discharge due to a Variation of the Duty Ratio of Pulse Modulation)

  • 박종인;황상혁;조태훈;윤명수;곽형신;진기남;전부일;최은하;권기청
    • 한국재료학회지
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    • 제25권11호
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    • pp.616-621
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    • 2015
  • Atmospheric pressure plasma is used in the biological and medical fields. Miniaturization and safety are important in the application of apply atmospheric plasma to bio devices. In this study, we made a small, pocket-sized inverter for the discharge of atmospheric plasma. We used pulse power to control the neutral gas temperature at which the, when plasma was discharged. We used direct current of 5 V of bias(voltage). The output voltage is about 1 to 2 kilo volts the frequency is about 80 kilo hertz. We analyzsed the characteristics of the atmospheric plasma using OES(Optical emission spectroscopy) and the Current-Voltage characteristic of pulse power. By calculating of the current voltage characteristics, we were able to determine that, when the duty ratio increased, the power that actually effects the plasma discharge also increased. To apply atmospheric plasma to human organisms, the temperature is the most important factor, we were able to control the temperature by modulating the pulse power duty ratio. This means we can use atmospheric plasma on the human body or in other areas of the medical field.

대기압 플라즈마를 이용한 결정질 태양전지 표면 식각 공정 (Dry Etching Using Atmospheric Plasma for Crystalline Silicon Solar Cells)

  • 황상혁;권희태;김우재;최진우;신기원;양창실;권기청
    • 한국재료학회지
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    • 제27권4호
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    • pp.211-215
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    • 2017
  • Reactive Ion Etching (RIE) and wet etching are employed in existing texturing processes to fabricate solar cells. Laser etching is used for particular purposes such as selective etching for grooves. However, such processes require a higher level of cost and longer processing time and those factors affect the unit cost of each process of fabricating solar cells. As a way to reduce the unit cost of this process of making solar cells, an atmospheric plasma source will be employed in this study for the texturing of crystalline silicon wafers. In this study, we produced the atmospheric plasma source and examined its basic properties. Then, using the prepared atmospheric plasma source, we performed the texturing process of crystalline silicon wafers. The results obtained from texturing processes employing the atmospheric plasma source and employing RIE were examined and compared with each other. The average reflectance of the specimens obtained from the atmospheric plasma texturing process was 7.88 %, while that of specimens obtained from the texturing process employing RIE was 8.04 %. Surface morphologies of textured wafers were examined and measured through Scanning Electron Microscopy (SEM) and similar shapes of reactive ion etched wafers were found. The Power Conversion Efficiencies (PCE) of the solar cells manufactured through each process were 16.97 % (atmospheric plasma texturing) and 16.29 % (RIE texturing).

새로운 대기압 플라즈마 소스를 이용한 결정질 실리콘 태양전지 인(P) 페이스트 도핑에 관한 연구 (A Study on Feasibility of the Phosphoric Paste Doping for Solar Cell using Newly Atmospheric Pressure Plasma Source)

  • 조이현;윤명수;조태훈;노준형;전부일;김인태;최은하;조광섭;권기청
    • 신재생에너지
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    • 제9권2호
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    • pp.23-29
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    • 2013
  • Furnace and laser is currently the most important doping process. However furnace is typically difficult appling for selective emitters. Laser requires an expensive equipment and induces a structural damage due to high temperature using laser. This study has developed a new atmospheric pressure plasma source and research atmospheric pressure plasma doping. Atmospheric pressure plasma source injected Ar gas is applied a low frequency (a few 10 kHz) and discharged the plasma. We used P type silicon wafers of solar cell. We set the doping parameter that plasma treatment time was 6s and 30s, and the current of making the plasma is 70 mA and 120 mA. As result of experiment, prolonged plasma process time and highly plasma current occur deeper doping depth and improve sheet resistance. We investigated doping profile of phosphorus paste by SIMS (Secondary Ion Mass Spectroscopy) and obtained the sheet resistance using generally formula. Additionally, grasped the wafer surface image with SEM (Scanning Electron Microscopy) to investigate surface damage of doped wafer. Therefore we confirm the possibility making the selective emitter of solar cell applied atmospheric pressure plasma doping with phosphorus paste.

대기물리 분야 연구논문 발전 현황 (Historical Development of Research and Publications in Atmospheric Physics Field)

  • 염성수;이규태;백종진;이규원;김상우;엄준식
    • 대기
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    • 제33권2호
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    • pp.105-124
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    • 2023
  • 본 문헌 검토 논문에서는 대기물리 분야를 편의상 대기복사, 대기 에어로졸, 구름물리 관측 및 실험, 구름모델링, 강수물리로 나누어 각 분야에서 196 3년 한국기상학회가 발족된 이후 지난 60년간 역사적으로 어떠한 학술적인 발전을 이루어왔는지를 검토하였다. 대기복사 분야에서는 주로 복사관측과 복사이론 연구에 꾸준한 발전을 이루어왔으나 상대적으로 학회 회원들의 활동이 저조했다고 할 수 있다. 대기 에어로졸과 구름물리 분야는 기후변화 인자로서의 에어로졸의 역할과 그 중요성이 부각되면서 많은 연구가 이루어졌다. 다양한 첨단 에어로졸 관측장비를 이용한 관측, 기상관측 전용항공기의 도입과 이를 이용한 에어로졸 연직분포 관측, 구름 속의 구름입자 직접 관측 등이 가능해졌고, 여러 국제 공동 에어로졸/구름 관측 캠페인에 주도적으로 참여하여 의미 있는 연구결과를 발표하고 있으며, 구름모델링 분야에서는 구름과정 모수화 연구에 학회 회원들의 기여가 두드러졌다. 또한 지상 원격탐사 장비를 이용한 강수입자 특성과 강수 물리 과정에 대한 연구도 매우 활발히 이루어졌다. 2022년 초에는 국립기상과학원이 구름챔버 제작을 완성하여 현재 세계적으로도 드물게 이루어지고 있는 구름챔버를 이용한 구름물리, 인공강수 연구를 시작 할 수 있게 되었다. 이러한 선도적 활동을 발판으로 향후에는 한국기상학회 회원들이 대기물리 분야에서 세계 기상학계를 이끌어 가는 커다란 발전을 이룰 것으로 전망해 본다.

대기압 플라즈마를 이용한 P타입 태양전지 웨이퍼 도핑 연구 (Study of P-type Wafer Doping for Solar Cell Using Atmospheric Pressure Plasma)

  • 윤명수;조태훈;박종인;김상훈;김인태;최은하;조광섭;권기청
    • Current Photovoltaic Research
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    • 제2권3호
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    • pp.120-123
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    • 2014
  • Thermal doping method using furnace is generally used for solar-cell wafer doping. It takes a lot of time and high cost and use toxic gas. Generally selective emitter doping using laser, but laser is very high equipment and induce the wafer's structure damage. In this study, we apply atmospheric pressure plasma for solar-cell wafer doping. We fabricated that the atmospheric pressure plasma jet injected Ar gas is inputted a low frequency (1 kHz ~ 100 kHz). We used shallow doping wafers existing PSG (Phosphorus Silicate Glass) on the shallow doping CZ P-type wafer (120 ohm/square). SIMS (Secondary Ion Mass Spectroscopy) are used for measuring wafer doping depth and concentration of phosphorus. We check that wafer's surface is not changed after plasma doping and atmospheric pressure doping width is broaden by increase of plasma treatment time and current.

광측정 데이터와 최적화 방법들을 이용한 대기입자 크기분포 복원 (The Reconstruction of Atmospheric Particle Size Distributions Using Optical Sensing Data and Some Regularization Methods l : Direct Methods)

  • Kim, Seok-Seong;Yeon, Kyu-Hwang;Kim, Duck-Hyun
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2003년도 추계학술대회 논문집
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    • pp.213-214
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    • 2003
  • Atmospheric particles have a great deal of influences on the climate and the air quality, which change the living and industrial environments of a specific area. Especially, the suspended dusts and aerosols can often have a harmful influences on workers' health, equipments at working places. For this reasons, the measurement of atmospheric particle size distributions is of considerable current interest. (omitted)

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