• 제목/요약/키워드: external Na supply

검색결과 14건 처리시간 0.023초

원료물질과 환원제의 외부공급에 따른 탄탈륨 분말의 제조 및 특성 (Production of Tantalum Powder and Characteristics by External Supply of Feed Material and Reductant)

  • 윤재식;박형호;배인성;김병일
    • 한국분말재료학회지
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    • 제10권5호
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    • pp.349-352
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    • 2003
  • This study examined the correlation of various operational factors including reaction temperature and the quantity of reductant and diluent with the characteristics of powder using $K_2$ TaF$_{7}$ as feed materials, Na as a reductant and KCl/KF as a diluent. Also to control the particle size and shape, external supply system developed, it can provide a feed material and a reductant at a fixed quantity and evaluated the characteristics of tantalum powder. When the external supply system was applied instead of the batch type process that charges feed material, reductant and diluent at the same time, it was possible to induce regular reduction reaction between feed material and reductant, which increased the recovery rate and reduced the mixture of impurities. In particular, the application of the external supply system enabled the control of reaction temperature and reaction speed according to the feeding rate of feed material during reduced reaction, and resultantly it enabled the manufacturing of granular-shaped powder with a regular granularity of 2∼3 ${\mu}{\textrm}{m}$ and purity of 99.5%.

Mo 기판위의 NaF 중간층을 이용한 Cu(In,Ga)Se2 광흡수층의 Na 도핑특성에 관한 연구 (Na Doping Properties of Cu(In,Ga)Se2 Absorber Layer Using NaF Interlayer on Mo Substrate)

  • 박태정;신동협;안병태;윤재호
    • 한국재료학회지
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    • 제19권8호
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    • pp.452-456
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    • 2009
  • In high-efficiency Cu(In,Ga)$Se_2$ solar cells, Na is doped into a Cu(In,Ga)$Se_2$ light-absorbing layer from sodalime-glass substrate through Mo back-contact layer, resulting in an increase of device performance. However, this supply of sodium is limited when the process temperature is too low or when a substrate does not supply Na. This limitation can be overcome by supplying Na through external doping. For Na doping, an NaF interlayer was deposited on Mo/glass substrate. A Cu(In,Ga)$Se_2$ absorber layer was deposited on the NaF interlayer by a three-stage co-evaporation process As the thickness of NaF interlayer increased, smaller grain sizes were obtained. The resistivity of the NaF-doped CIGS film was of the order of $10^3{\Omega}{\cdot}cm$ indicating that doping was not very effective. However, highest conversion efficiency of 14.2% was obtained when the NaF thickness was 25 nm, suggesting that Na doping using an NaF interlayer is one of the possible methods for external doping.

Fabrication of wide-bandgap β-Cu(In,Ga)3Se5 thin films and their application to solar cells

  • Kim, Ji Hye;Shin, Young Min;Kim, Seung Tae;Kwon, HyukSang;Ahn, Byung Tae
    • Current Photovoltaic Research
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    • 제1권1호
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    • pp.38-43
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    • 2013
  • $Cu(In,Ga)_3Se_5$ is a candidate material for the top cell of $Cu(In,Ga)Se_2$ tandem cells. This phase is often found at the surface of the $Cu(In,Ga)Se_2$ film during $Cu(In,Ga)Se_2$ cell fabrication, and plays a positive role in $Cu(In,Ga)Se_2$ cell performance. However, the exact properties of the $Cu(In,Ga)_3Se_5$ film have not been extensively studied yet. In this work, $Cu(In,Ga)_3Se_5$ films were fabricated on Mo-coated soda-lime glass substrates by a three-stage co-evaporation process. The Cu content in the film was controlled by varying the deposition time of each stage. X-ray diffraction and Raman spectroscopy analyses showed that, even though the stoichiometric Cu/(In+Ga) ratio is 0.25, $Cu(In,Ga)_3Se_5$ is easily formed in a wide range of Cu content as long as the Cu/(In+Ga) ratio is held below 0.5. The optical band gap of $Cu_{0.3}(In_{0.65}Ga_{0.35})_3Se_5$ composition was found to be 1.35eV. As the Cu/(In+Ga) ratio was decreased further below 0.5, the grain size became smaller and the band gap increased. Unlike the $Cu(In,Ga)Se_2$ solar cell, an external supply of Na with $Na_2S$ deposition further increased the cell efficiency of the $Cu(In,Ga)_3Se_5$ solar cell, indicating that more Na is necessary, in addition to the Na supply from the soda lime glass, to suppress deep level defects in the $Cu(In,Ga)_3Se_5$ film. The cell efficiency of $CdS/Cu(In,Ga)_3Se_5$ was improved from 8.8 to 11.2% by incorporating Na with $Na_2S$ deposition on the CIGS film. The fill factor was significantly improved by the Na incorporation, due to a decrease of deep-level defects.

염 환경에서 질소공급에 따른 4종 콩과식물의 생장반응과 무기이온양상의 비교 (Comparison of Patterns of Mineral Ions and Growth Responses of 4 Legume Plants by Nitrogen Applications under Saline Conditions)

  • 배정진;추연식;송승달
    • 생명과학회지
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    • 제13권4호
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    • pp.473-480
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    • 2003
  • 공생적 질소고정에 의해서 생장에 필요한 질소를 공급받는 콩과식물이 염분 스트레스하에서 보이는 생장반응 및 무기이온 양상을 규명하기 위해 대표적인 콩과식물 4종(대두, 팥, 긴강남차, 자귀나무)을 질소고정균을 접종한 다음, 무질소구와 질소공급구(2.5 mM $NH_4NO_3$)로 나누어서 0, 10, 40 및 100 mM NaCl을 처리하였으며, 식물의 생장반응 그리고 무기이온 및 총질소함량을 정량적으로 분석하였다. 대두, 팥 및 자귀나무의 경우, 40 mM NaCl 이상의 염처리에 의해 현저한 생장저해를 보였으나, 긴강남차는 100 mM NaCl 까지 정상적인 생장을 보였다. 무기이온에 대해서도 대두, 팥 및 자귀나무는 현저한 생장저해현상을 보였던 40 mM NaCl 이상의 처리구에서는 과도한 $Na^+$$Cl^+$이온의 축적양상을 보였으나, 긴강남차의 경우 염 농도의 증가에도 불구하고 체내 일정한 무기이온함량을 유지하였다. 4종 콩과식물은 공생적 질소고정에 전적으로 의존하는 식물보다 외부에서 질소를 공급한 경우 체내 일정한 이온함량을 유지하였다. 질소양상에 있어, 대두와 팥은 염 농도가 증가함에 따라 총질소함량이 점차 감소한 반면 긴강남차와 자귀나무는 염 구배에 따라 총질소함량(특히 불용성질소)이 점차 증가하는 양상을 보였다. 대두와 팥에서 총질소함량은 감소하였지만 아미노산 함량은 증가하여 높은 가용성/불용성 질소비를 나타내었다. 다소 예외는 있지만 조사된 4종 콩과식물에서 부가적인 질소공급은 생장의 증가는 물론 특정이온 및 고농도 염에 의한 독성효과를 완화시킴으로써 염에 대한 내성을 증가시키는 것으로 생각된다.

SCM 기법에 의한 비정형 콘크리트 패널의 공급관리 모델 기초연구 (Basic Study of Distribution Management Model of the Free-Form Concrete Panels)

  • 조원현;나영주;김선국
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.115-116
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    • 2016
  • Numerous of free-form buildings come up with external appearances using various types of free-form panels. If the panel types produced, transport and installation order and maintenance history are not properly managed, it is difficult to complete a given project successfully. For free-form building projects that satisfy 5 factors (proper time, place, price, product and quantity), a supply chain management technique is applied for distribution management of free-form concrete panels. In addition, the study listed the whole production process of free-form concrete panels and any necessary information, and suggested a basic model for the management. The study result will be a great help in effective distribution management of free-form panels for free-form building projects.

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연근해 어선용 해수냉각장치의 열부하특성 (Heat Load Characteristics of Sea Water Cooling Apparatus on Inshore Fishing Boat)

  • 한인근;문춘근;김재돌;윤정인
    • Journal of Advanced Marine Engineering and Technology
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    • 제25권6호
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    • pp.1317-1323
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    • 2001
  • The circumstance is giving the blow against fishermen with the incoming-decreasing and the difficulty of crew's supply & demand and management. In addition, the depression of the external situation like the departure of WTO system and the plan of EEZ proclaim is forcing fishery into improving their fishing condition. By this international and domestic circumstance, development of the sea water cooling apparatus for fish hold storage is demanded sincerely. First of all, we Investigated load characteristics which based on development of sea water cooling system and optimum fish hold storage. The experimental results is as follows. In creasing the speed of compressor and mass blew rate of refrigerant, the temperature of NaCl solution is low. And the load characteristics experiment on fish hold storage outlet is as fellows. As time goes by, increasing the mass flow rate of NaCl solution, temperature difference between inlet and outlet is small in a model of fish hold storage. These results provide many useful informations applicable to an actual design of sea water cooling system and optimum fish hold storage.

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염처리가 수도잎의 신장 및 광합성능에 미치는 영향 (Effects of Salinity on Leaf Growth and Photosynthesis in Rice)

  • Lee, Kang-Sae
    • 한국작물학회지
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    • 제36권1호
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    • pp.22-33
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    • 1991
  • 간장이 다른 수도 2품종에 대하여 NaCl, KCl, Mannitol을 처리하고 잎의 신장과 광합성능의 반응을 조사하였다. 그리고 염처리에 의하여 잎의 신장이 일시적으로 정지하고 신장률이 둔화되는 현상 및 높은 농도에서 광합성능이 저하되는 원인에 대하여 고찰하였다.

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염분 환경하에서 4종 콩과식물의 생장, 아미노산 및 질소함량에 미치는 질소원의 영향 (Effects of Nitrogen Application on the Patterns of Amino Acids, Nitrogen Contents and Growth Response of Four Legume Plants under Saline Conditions)

  • 배정진;추연식;김진아;노광수;송종석;송승달
    • The Korean Journal of Ecology
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    • 제26권3호
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    • pp.135-142
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    • 2003
  • 콩과식물의 염분 내성에 대한 질소원의 영향을 규명하기 위하여 4종 콩과식물을 선택하여 100 mM까지의 NaCl을 처리하였다. 염-민감성 종으로 알려진 대두와 팥은 염분 농도가 증가함에 따라 총 질소 함량이 점차 감소하는 반면, 아미노산 함량은 현저히 증가(100 mM NaCl 처리된 대두 무질소구의 경우 대조구의 4.7배)하여 높은 가용성/불용성 질소 비를 보였다. 대조적으로 염분 내성을 보이는 긴강남차와 자귀나무는 아미노산을 거의 함유하지 않았으며, 염 구배에 따라 총 질소 함량(특히 불용성 질소)이 점차 증가하는 양상을 보였다. 대두와 팥은 아미노산 중 asparagine (Asn)을 다량으로 함유하였으며, Asn은 이들 식물의 대표적인 질소의 수송 및 저장형태로서 염분 환경하에서 이들 식물의 세포질 내 삼투조절에 관여하는 것으로 생각된다. 염 환경에서 대두의 생장에 대한 질소원 및 농도의 영향은 5 mM NH₄NO₃-N 처리구에서 가장 높은 건물함량(10mM NaCl 처리구의 지상부건물함량의 경우 대조구의 약 1.5배)을 보였고, NH₄-N을 공급한 식물의 경우 질소를 공급하지 않은 대조구보다 생장이 저해되었으며, 처리 15일 이후 40과 80 mM NaCl 처리구에서 모두 고사하였다. 따라서 대두의 생장은 NH₄-N, 대조구, NO₃-N, NH₄NO₃-N의 순으로 질소공급량이 증가할수록 염에 대한 저항성이 증가하는 것으로 나타났다.

흰쥐의 구속 stress 에 의한 catecholamine 의 변화 (Variation of Catecholamine Content in Rat Vline under the Immo bilization Stress)

  • 김형석
    • 환경위생공학
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    • 제6권2호
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    • pp.59-68
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    • 1991
  • The word of stress was wsed in the field of physics as a external force from 17th century, but the meaning of this stress had chafed to the internal and exteral demand fort the human body in medical area. All the stumulants which make stress was called as j stressor. When animals get stress blucose excreted from liver to adapt for the emergent state ant some related hormone secrete convert protein and lipid to glucose for the purpose of energy supply to muscle. As a results heart rate, blood pressure, respiration rate are increased and musclse are strengthed. These physiolgical reactions ate controlled by autonomic nerve system under the control of hyothalamus in brain. Autonomic nerve system and endocrinary system are react harmoiously to stress reaction. According to the stress reaction, adrenomedullary system are stimulated, and epinephrine, morepinephrine are exceted. Author experimented the effect of the immobilizational stress to rat by analyzing the variaition of catecholamine secrction, the Na concentration and the effect of the antistresf effect by Panax Ginseng which is a traditional Korean herb medicine. The concentration of the norepinephrine, epinephrin, and dopamin in normal rat are 1 578 ng/ml, 0.365 ng/ml, and 0.731 ng/ml respectively, but in the immobilyzed stress groIn the concentration were increased to 1.915 ng.ml, 0.854 ng/ml, and 2,361 ng/ml which she the high show the higher concentration of catecholamine to stressor.

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극저준위 백그라운드 감마선 측정시스템의 성능시험 (Performance Test of the Ultralow Background Gamma-Ray Measurement System)

  • 나원우;이영길
    • Journal of Radiation Protection and Research
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    • 제22권3호
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    • pp.219-226
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    • 1997
  • 환경시료 및 Swipe시료에서 방출되는 감마선을 측정 분석하기 위하여 극저준위 백그라운드 감마선 측정시스템을 설치하였다. 본 측정시스템은 백그라운드를 저감하기 위해 극저방사능 물질로 구성된 수동적 차폐방법, 우주선 영향을 차단하기 위한 역동시 측정법, 그리고 공기중 방사성 핵종인 라돈가스를 시스템 내부에서 제거하는 방법 등을 적용하고 있다. 적용된 백그라운드 저감법에 대한 성능시험 결과, 실험실 조건의 백그라운드 준위가 관심 대상 에너지 영역($50\;keV{\sim}2\;MeV$)에서 $10^{-2}$ order 정도로 저감되었다. 그리고 미신고 핵활동을 탐지하기 위한 관심 대상 핵종의 감마선 에너지 영역에서 평가된 시스템의 최소검출하한(MDA)값은 환경시료 분석에 적합한 것으로 평가되었다. 그러나 저에너지 영역에서는 여전히 우주선에 의한 중성자 영향이 백그라운드 요인으로 작용하고 있는 것으로 분석되었다.

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