• 제목/요약/키워드: single grain

검색결과 572건 처리시간 0.028초

전자빔 증착기로 제작한 태양전지용 $CuInS_2$ 박막특성 (Properties of $CuInS_2$ thin film Solar Cell Fabricated by Electron beam Evaporator)

  • 양현훈;김영준;정운조;박중윤;박계춘
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.379-380
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    • 2005
  • Single phase $CuInS_2$ thin film with a highest diffraction peak (112) at a diffraction angle ($2\Theta$) of $27.7^{\circ}$ was well made by SEL method at annealing temperature of $250^{\circ}C$ and annealing hour of 60 min in vacuum of $10^{-3}$ Torr or in S ambience for an hour. And the peak of diffraction intensity at miller index (112) of $CuInS_2$ thin film annealed in S ambience was shown a little higher about 11 % than in only vacuum. Single phase $CuInS_2$ thin films were appeared from 0.85 to 1.26 of Cu/In composition ratio and sulfur composition ratios of $CuInS_2$ thin films fabricated in S ambience were all over 50 atom%. Also when $CuInS_2$ composition ratio was 1.03, $CuInS_2$ thin film with chalcopyrite structure had the highest XRD peak (112). The largest lattice constant of a and grain size of $CuInS_2$ thin film in S ambience was 5.63 ${\AA}$ and 1.2 ${\mu}m$ respectively. And the films in S ambience were all p-conduction type with resistivities of around $10^{-1}{\Omega}cm$.

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CeO2 완충층의 결정성장 특성 및 금속 유기물 증착법으로 제조된 초전도 YBCO층에 미치는 영향 (Texture Development of CeO2 Buffer Layer and its Effect on Superconducting MOD-YBCO Films)

  • 정국채;김영국
    • 대한금속재료학회지
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    • 제47권10호
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    • pp.681-685
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    • 2009
  • $CeO_2$ buffer layers have been deposited on YSZ single crystal substrates via a radio-frequency sputtering method. We focused on the texture development of $CeO_2$ with out-of-plane alignment and its effects on a superconducting YBCO layer, which was deposited by metal organic deposition. $CeO_2$ layers were grown epitaxially on single crystal YSZ substrates and subsequent YBCO layers were also grown epitaxially from $CeO_2$ layers. It was observed that the intensity of $CeO_2$(200) decreased with deposition temperature. ${\theta}-2{\theta}$ scan FWHM values of $CeO_2$(200) were inversely proportional to the peak intensities of $CeO_2$(200). The sample with the lowest $CeO_2$(200) intensity and poor out-of-plane alignment showed a strong reaction with the MOD-YBCO layer resulting in a thicker $BaCeO_3$ layer. The texture and superconducting property of the YBCO layer were affected indirectly by the formation of a $BaCeO_3$ layer at the interface between the $CeO_2$ and YBCO layers.

Ag 중간층 두께에 따른 ZnO 박막의 광학적, 전기적 특성 연구 (Effect of Ag interlayer on the optical and electrical properties of ZnO thin films)

  • 김현진;장진규;최재욱;이연학;허성보;공영민;김대일
    • 한국표면공학회지
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    • 제55권2호
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    • pp.91-95
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    • 2022
  • ZnO single layer (60 nm thick) and ZnO with Ag interlayer (ZnO/Ag/ZnO; ZAZ) films were deposited on the glass substrates by using radio frequency (RF) and direct current (DC) magnetron sputter to evaluate the effectiveness of Ag interlayer on the optical visible transmittance and the conductivity of the films. In the ZAZ films, the thickness of ZnO layers was kept at 30 nm, while the Ag thickness was varied as 5, 10, 15 and 20 nm. In X-ray diffraction (XRD) analysis, ZnO films show the (002) diffraction peak and ZAZ films also show the weak ZnO (002) peak and Ag (111) diffraction peak. As a thickness of Ag interlayer increased to 20 nm, the grain size of the Ag films enlarged to 11.42 nm and the optical band gap also increased from 4.15 to 4.22 eV with carrier concentration increasing from 4.9 to 10.5×1021 cm-3. In figure of merit measurements, the ZAZ films with a 10 nm thick Ag interlayer showed the higher figure of merit of 4.0×10-3 Ω-1 than the ZnO single layer and another ZAZ films. From the experimental result, it is assumed that the Ag interlayer enhanced effectively the opto-electrical performance of the ZAZ films.

전단벽의 전단성능 예측 모형 (Theoretical Models for Predicting Racking Resistance of Shear Walls)

  • 장상식
    • Journal of the Korean Wood Science and Technology
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    • 제30권4호
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    • pp.96-105
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    • 2002
  • 전단벽은 현대식 경골목조건축에서 바람이나 지진 등에 의한 측방하중에 대한 저항력을 제공하는 가장 중요한 요소 중의 하나이다. 전단벽에서 건물에 전달된 측방하중은 벽의 스터드와 덮개재료 사이의 못접합부를 통하여 덮개재료로 전달되고 덮개재료에 전달된 하중은 판재의 면전단력에 의하여 지지된다. 따라서 실제 전단벽에서 측방하중에 대한 저항력을 결정하는 가장 중요한 요소는 못접합부라고 할 수 있을 것이다. 이 연구에서는 스터드와 판재 사이의 못접합부에 대한 강성 및 강도를 측정하였으며 이 값들은 전단벽의 찌그러짐 저항력을 예측하는 이론모형의 입력자료로 사용되었다. 이론모형의 예측치의 정확성을 검증하기 위하여 판재 한 장으로 구성된 전단벽의 전단시험을 수행하였다. 못접합부의 강성은 스터드 부재의 섬유방향에 의하여 영향을 받았으나 판재의 방향은 거의 영향을 미치지 않는 것으로 나타났다. 전단하중 하에서 못접합부나 전단벽의 거동은 3개의 직선구간으로 나나낼 수 있었으며 이론모형 I보다 이론모형 II의 예측치가 더 정확하였다.

단일연소관 이중추력 로켓모터의 내탄도성능 분석법 연구 (Study on Internal Ballistic Performance Analysis for Single-chamber Dual-thrust Rocket Motors)

  • 권혁민
    • 한국추진공학회지
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    • 제24권4호
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    • pp.1-11
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    • 2020
  • 본 연구에서는 추진제 연소면적을 조절하여 이중추력 프로파일을 구현하는 단일연소관 이중추력 로켓모터의 내탄도성능 분석 방법을 제시한다. 천이 구간에서의 연소속도 보정계수 및 비추력의 점진적 변화를 고려하며 성능 예측에 필요한 변수를 획득할 수 있는 분석법을 제시하고, 해당 분석법을 적용한 결과와 천이 구간 내 변화를 고려하지 않는, 기존 연구의 분석법을 적용한 결과를 비교함으로써 새로 제시하는 분석법에서 개선된 부분을 확인한다. 추진제 초기 온도 또는 배치 조건이 다른 네 가지의 시험 조건에 대하여 제시하는 분석법을 이용해 내탄도 변수를 획득하고, 이를 이용하여 각 시험 조건별로 성능 예측을 수행한다. 해당 예측 결과는 실제 연소시험 결과와 잘 일치하며, 따라서 본 연구의 분석법을 기반으로 설계 형상이 동일한 이중추력 모터의 성능 예측이 가능함을 확인할 수 있다.

"제민요술(齊民要術)"에 수록된 식품조리 가공법 연구보고 (I) -술- (A Study on the Cooking and Processing Methods Presented in CHE MIN YO SUL(Chinese Book of Husbandary) -Wines-)

  • 윤서석;윤숙경;조후종;이효지;안명수;안숙자;서혜경;윤덕인;임희수
    • 한국식생활문화학회지
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    • 제5권3호
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    • pp.349-359
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    • 1990
  • This study was carried out to understand and analyze the cooking and processing methods presented in CHE MIN YO SUL, Chinese books of husbandary was written in sixth century. This book was composed of two parts-part I is Agricultural production and part II is product-Utilization. Especially, wines and yeast(NU RUK) written in part II were studied at this study paper. Most of yeast was made of barley and wheat. These materials had been prepared as raw, steamed, and roasted state by proper ratio with kinds of yeast and then fermented as dough state. Occasionally, various kinds of soup made from cocklebur, leaves of mulberry tree, wormwood etc. put into yeast dough. Yeast doughs were shaped round and square with or without hole in the center, made in July of the lunar calendar and fermented for 3 or 4 weeks. There were 43 kinds of wines in this book. Most of them were made of all kinds of cereals grown at that time-rice, waxy rice, millet, waxy millet etc. These cereals had been steaming or cooking gruel with grain or powder state and then fermented with yeast. These wines were prepared by single or double brewing methods and the kinds of double brewing wines were more than single brewing wines by two times. There were none of wines made from fruit and distilled wines. Generally, single brewing wines were not made in Apr., Nov., Dec., of the lunar calendar and double brewing wines were not made in Aug., Oct., Nov., of the lunar calendar. And ripenning periods of wine brewing were various, from 1 day to 7 months for single brewing, from 2 days to 8 months for double brewing.

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New Approaches for Overcoming Current Issues of Plasma Sputtering Process During Organic-electronics Device Fabrication: Plasma Damage Free and Room Temperature Process for High Quality Metal Oxide Thin Film

  • Hong, Mun-Pyo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.100-101
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    • 2012
  • The plasma damage free and room temperature processedthin film deposition technology is essential for realization of various next generation organic microelectronic devices such as flexible AMOLED display, flexible OLED lighting, and organic photovoltaic cells because characteristics of fragile organic materials in the plasma process and low glass transition temperatures (Tg) of polymer substrate. In case of directly deposition of metal oxide thin films (including transparent conductive oxide (TCO) and amorphous oxide semiconductor (AOS)) on the organic layers, plasma damages against to the organic materials is fatal. This damage is believed to be originated mainly from high energy energetic particles during the sputtering process such as negative oxygen ions, reflected neutrals by reflection of plasma background gas at the target surface, sputtered atoms, bulk plasma ions, and secondary electrons. To solve this problem, we developed the NBAS (Neutral Beam Assisted Sputtering) process as a plasma damage free and room temperature processed sputtering technology. As a result, electro-optical properties of NBAS processed ITO thin film showed resistivity of $4.0{\times}10^{-4}{\Omega}{\cdot}m$ and high transmittance (>90% at 550 nm) with nano- crystalline structure at room temperature process. Furthermore, in the experiment result of directly deposition of TCO top anode on the inverted structure OLED cell, it is verified that NBAS TCO deposition process does not damages to the underlying organic layers. In case of deposition of transparent conductive oxide (TCO) thin film on the plastic polymer substrate, the room temperature processed sputtering coating of high quality TCO thin film is required. During the sputtering process with higher density plasma, the energetic particles contribute self supplying of activation & crystallization energy without any additional heating and post-annealing and forminga high quality TCO thin film. However, negative oxygen ions which generated from sputteringtarget surface by electron attachment are accelerated to high energy by induced cathode self-bias. Thus the high energy negative oxygen ions can lead to critical physical bombardment damages to forming oxide thin film and this effect does not recover in room temperature process without post thermal annealing. To salve the inherent limitation of plasma sputtering, we have been developed the Magnetic Field Shielded Sputtering (MFSS) process as the high quality oxide thin film deposition process at room temperature. The MFSS process is effectively eliminate or suppress the negative oxygen ions bombardment damage by the plasma limiter which composed permanent magnet array. As a result, electro-optical properties of MFSS processed ITO thin film (resistivity $3.9{\times}10^{-4}{\Omega}{\cdot}cm$, transmittance 95% at 550 nm) have approachedthose of a high temperature DC magnetron sputtering (DMS) ITO thin film were. Also, AOS (a-IGZO) TFTs fabricated by MFSS process without higher temperature post annealing showed very comparable electrical performance with those by DMS process with $400^{\circ}C$ post annealing. They are important to note that the bombardment of a negative oxygen ion which is accelerated by dc self-bias during rf sputtering could degrade the electrical performance of ITO electrodes and a-IGZO TFTs. Finally, we found that reduction of damage from the high energy negative oxygen ions bombardment drives improvement of crystalline structure in the ITO thin film and suppression of the sub-gab states in a-IGZO semiconductor thin film. For realization of organic flexible electronic devices based on plastic substrates, gas barrier coatings are required to prevent the permeation of water and oxygen because organic materials are highly susceptible to water and oxygen. In particular, high efficiency flexible AMOLEDs needs an extremely low water vapor transition rate (WVTR) of $1{\times}10^{-6}gm^{-2}day^{-1}$. The key factor in high quality inorganic gas barrier formation for achieving the very low WVTR required (under ${\sim}10^{-6}gm^{-2}day^{-1}$) is the suppression of nano-sized defect sites and gas diffusion pathways among the grain boundaries. For formation of high quality single inorganic gas barrier layer, we developed high density nano-structured Al2O3 single gas barrier layer usinga NBAS process. The NBAS process can continuously change crystalline structures from an amorphous phase to a nano- crystalline phase with various grain sizes in a single inorganic thin film. As a result, the water vapor transmission rates (WVTR) of the NBAS processed $Al_2O_3$ gas barrier film have improved order of magnitude compared with that of conventional $Al_2O_3$ layers made by the RF magnetron sputteringprocess under the same sputtering conditions; the WVTR of the NBAS processed $Al_2O_3$ gas barrier film was about $5{\times}10^{-6}g/m^2/day$ by just single layer.

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사료작물-벼 작부체계가 조생종 벼의 생육과 미질 특성 및 토양의 화학적 특성에 미치는 영향 (Effects of Forage-Rice Cropping Systems on the Growth and Grain Quality of Early Maturing Rice Cultivars and Soil Chemical Properties in Paddy Fields in Southern Korea)

  • 오서영;오성환;서종호;최지수
    • 한국작물학회지
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    • 제66권4호
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    • pp.297-306
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    • 2021
  • 본 연구에서는 사료작물-벼 2모작 작부체계에 적합한 벼 품종을 선발하고자, 사료작물 중 재배면적이 가장 많은 이탈리안라이그라스와 귀리를 연계한 2모작 작부체계에서 토양특성, 조생종 벼의 생육 특성과 미질의 변화를 조사하였다. 벼 앞그루로 겨울철에 휴경하였을 때보다 사료작물을 재배하였을 때 논 토양 내 pH가 다소 낮아지고 T-N, K, Ca, Na 함량이 높았으며 유기물과 유효인산(Av. P2O5) 함량은 다소 감소하였다. 이는 겨울철 사료작물 재배로 인해 논 토양의 화학적 특성이 개선될 수 있음을 보여준다. 출수기에 해담쌀을 제외한 3종의 조생종 벼에서는 간장, 수장, 수수, 엽색도가 대체로 벼 단작에 비해 사료작물-벼 재배답에서 높게 나타났다. 그러나 해담쌀은 간장과 엽색도가 차이가 없고, 수장이 다소 짧아졌지만 수수는 오히려 증가하는 양상을 보였다. 그리고, 수확기에 백미수량이 2모작 작부체계에서 다른 3종은 다소 감소하지만 해담쌀은 차이를 보이지 않았다. 그리고, 완전미의 비율은 사료작물-벼 2모작 재배 시 다소 높았으며, 특히 조평과 해담쌀에서 높았다. 백미의 단백질 함량은 벼 단작에 비해 사료작물-벼 재배에서 높았고, 아밀로스 함량은 벼 단작과 같거나 그보다 다소 낮았다. Toyo 식미치는 사료작물-벼 작부체계에서 대체로 감소하였으며, 호화온도는 모든 품종에서 작부체계별로는 통계적으로 유의미한 차이를 보이지 않았다. 그럼에도 불구하고, 해담쌀은 2모작 작부체계에서도 다른 품종에 비하여 호화온도가 낮으면서 Toyo 식미치값이 높아서, 식미도 가장 양호한 것으로 나타났다. 더욱이 그 생장은 작부체계에 따라 차이가 없으나 수수는 오히려 2모작 작부체계에서 증가하여 백미수량 감소가 없는 것으로 나타나, 해담쌀이 사료작물과 연계한 논 기반 작부체계에 최적의 품종으로 보인다.

Sintering Effects on Fe/Mo Ordering and Magnetoresistance in Double Perovskite Sr2FeMoO6

  • Kim, J;Park, B.J;Lee, B.W
    • Journal of Magnetics
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    • 제9권1호
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    • pp.9-12
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    • 2004
  • We have investigated sintering effects on Fe/Mo ordering and magnetoresistance (MR) in double perovskite-reflection lines due to $Sr_2FeMoO_6$ (SFMO). Polycrystalline samples have been prepared by the conventional solid-state reaction by sintering in a stream of 5% $H_2/Ar$ gas. All samples are single phase and exhibit a series of superstructurecation ordering at Fe and Mo sites. As sintering temperature increases from 900 to $1300^{\circ}C$, the degree of Fe/Mo ordering increases from 82 to 92%, magnetization (15 K, 7 kOe) increases from 1.6 to 2.7 ${\mu}_B/f.u.,$ and Curie temperature increases at a rate of 4.3 K/% with the increase of Fe/Mo ordering ratio. The magnitude of MR measured at 5 K is 19% for sample prepared at $1000^{\circ}C$ with magnetic fields of 7 kOe. The observed MR is proportional to the square of magnetization indicating that the MR feature in SFMO is explained by the spin-polarized tunneling at grain boundaries.

Chemical, Physical Sensory Properties of Expanded Extrudates from Pork Meat-Defatted by Soy Flour-Corn Starch Blends, With or Without Ingredients Derived from Onion, Carrot and Oat

  • Jennifer J. Jamora;Rhee, Ki-Soon;Rhee, Khee-Choon
    • Preventive Nutrition and Food Science
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    • 제6권3호
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    • pp.158-162
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    • 2001
  • Blends of pork meat (20%), defatted soy flour (25%), and corn starch (48.61~53.71%) were prepared with or without additional non-meat ingredients, i.e., onion powder (1%), alone or in combination with carrot powder (1.5%) or extract (1.5%), or defatted oat flour (5%). All blends were formulated for 22.78% moisture, with water added where necessary. They were extruded using a laboratory single-screw extruder at 16$0^{\circ}C$ profess temperature and 170 rpm screw speed. The additional ingredients generally decreased product expansion and increased bulk density and shear force. When the product with no additional ingredient and the product with onion powder were evaluated by trained sensory panelists, \"grain complex\" was the most intense flavor note for both. With 1 % onion powder in feed, a distinct \"onion\" flavor note was detectable in extrudates. All the products may be considered \"healthful\" based on nutrient profiles.t; based on nutrient profiles.

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