• 센서학회지
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• 제8권2호
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• pp.95-101
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• 1999

반도체 센서(p-MOSFET)가 이온화 방사선에 노출되면 산화층내에 전자-정공이 생성되고, 이들 중에서 이동도가 낮은 정공은 이동중 산화층내에 트랩(trap)되어 센서의 출력 특성을 변화시킨다. 본 논문에서는 p-MOSFET를 방사선 누적선량 모니터링 센서로 활용하기 위해 국산 및 일산의 상용 p-MOSFET를 Co-60 $\gamma$선원을 갖춘 고준위 조사시설에서 조사한 후 출력특성의 변화를 분석하였다. 방사선 조사실험 결과 p-MOSFET는 조사된 누적 방사선량에 비례하여 문턱전압(threshold voltage, $V_T$)이 변화됨과 이 변화에는 선형적 특성을 지님을 알 수 있었다. 본 논문의 결과를 통하여 저가의 상용 p-MOSFET를 이용한 우수한 성능의 방사선 누적선량 모니터링 센서를 개발할 수 있음을 확인하였다.

• Korean Chemical Engineering Research
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• 제46권6호
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• pp.1057-1062
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• 2008

기존 2탑 유동층 공정의 단점을 극복하기 위해 두 개의 기포유동층, 고체분사노즐, 상승관 및 고체재순환관으로 구성된 신개념 2탑 유동층 공정을 적용한 3 kW 매체순환식 가스연소기를 개발하였다. 본 연구에서는 3 kW급 매체순환식 가스연소기에서 고체순환속도에 미치는 고체분사노즐 유속, 유동화속도, 고체층 높이, 고체유입구의 단면적, 층 온도 등의 영향을 고찰하였다. 고체순환속도는 고체층 높이가 증가하고 고체유입구의 단면적이 증가할수록 증가하는 경향을 나타내었으며 유동화속도와 온도의 영향은 크지 않았다. 장기연속운전 가능성을 검토하기 위해 50시간까지 고체순환 장기연속운전을 실증하였다. 두 유동층과 고체재순환관의 압력강하 값이 안정적으로 유지되어 고체순환이 원활하고 안정적으로 유지되는 것을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.93-93
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• 2003

Photoluminescence(PL) properties of Silicon nanocrystals (nc-Si) as a function of temperature is reported to consider the mechanism of PL. Nc-Si has been made by $Si^+$ ion-implantation into thermal $SiO_2$ and subsequent annealing. And after gold had been diffused at the same samples above, the resultant PL spectra has been compared to the PL spectra from the non-gold doped nc-Si. PL peak energy variation from nc-Si is same with the variation of energy bandgap of bulk silicon as temperature changes from 6 K to room temperature. This result may mean nc-Si is still indirect transition material like bulk silicon. Gold doped nc-Si reveals short peak wavelength of PL spectrum than gold undoped one. PL peak shift through gold doing process shows clearly the PL mechanism is not from defect or interface states. PL intensity increases from 6K to a certain temperature and then decrease to room temperature. This characteristic with temperature shows that phonon have a role for the luminescence as theory explains that electron and hole can be recombined radiatively by phonon's assist in nc-Si, which is almost impossible in bulk silicon. Therefore luminescence is observed in nc-Si constructed less than a few of unit cell and the peak energy of luminescence can be higher than the bulk bandgap energy by the bandgap widening effect occurs in nanostructure.

• 대한본초학회지
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• 제26권4호
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• pp.139-147
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• 2011

Objectives : The aim of this study is to research an anti-thrombus effect by Diospyros Kaki Calyx. Methods : The healthy human plasma were gained and used in vitro study such as factor X activity (FXa) inhibition, prothrombinase inhibition, prothrombin time (PT) and activated partial thromboplastin time. Fifteen SD rats were divided into three groups ; intact control group (orally administrated with distilled water 5ml/kg) and two experimental group treated with extract of diospyros kaki calyx (EKC). Experimental rats were orally 600 mg/kg concentration of EKC and 200 mg/kg concentration of EKC. After an hour from administration, we anesthetized rats and made arteriovenous (AV) shunt rat models to study weight of thrombus, took whole blood to study content of thromboxane B2 and blood clotting time. Results : In vitro, EKC significantly increased inhibitory activity of FXa, prothrombinase compared with intact control group ($^*P$ <0.05). PT and aPTT were increased in EKC treated (600 mg/kg) group compared with intact control group ($^*P$ <0.05). In vivo, blood clotting time of experiment group treated with EKC 600 mg/kg were significantly increased compare with that of intact control group (p<0.05) and content of thromboxane B2 was significantly decreased in group treated with EKC 600 mg/kg in serum. The weight of thrombus were significantly reduced in group treated with EKC 600 mg/kg compared with intact control group (p<0.05). But in vivo experiment study, those parameters of group treated with EKC 200 mg/kg were relatively decreased compared with those of intact control group without statistical significance. Conclusions : EKC has an antithrombic activity because of inhibition internal course such as FXa and prothrombin. And EKC inhibited a hole blood clotting in vivo experiment by low content of thromboxane B2.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1680-1686
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• 2009

삼각 분리 막대형 차압 유량계 압력 탭의 가공 조건에 따른 유량 특성을 연구하였다. 삼각 분리 막대탭 차압 유량계에 가공한 압력 탭의 크기는 1.0 mm 또는 1.5 mm로 하였다. 압력 탭의 개수는 5개 또는 17개로 가공하였다. 삼각 분리 막대탭 차압 유량계와 층류유량계를 직결한 후 유량 특성을 검정하였다. 삼각 분리 막대탭 차압 유량계의 질량 유량을 무차원 파라미터 H를 사용하여 나타내었다. H는 TSB 유량계에서의 배압, 기체 온도, 유량계 상류압과 하류압 간의 차압을 포함하는 무차원 파라미터이다. TSB 유량계의 질량 유량과 H 간에는 선형적 관계를 보였다. 압력 탭의 개수 보다는 압력 탭의 직경이 TSB 차압유량계의 유량 특성에 더 큰 영향을 미쳤다.

• 한국전산구조공학회논문집
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• 제30권2호
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• pp.145-151
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• 2017

콘크리트 구조물 또는 암석의 해체 공정에서 소음, 진동, 분진 등의 발생을 초래하는 기존의 발파공법을 대신하여 비폭성 파쇄제의 이용을 고려할 수 있다. 본 연구는 유한한 정사각형 콘크리트 구조물을 대상으로 하여 비폭성 파쇄제의 팽창이 준정적으로 균열을 발생, 진전시키는 과정을 유한요소해석으로 예측하고 기존 문헌에 보고된 실험결과와 비교함으로써 해석결과의 정확성을 검증하였다. 또한 비폭성 파쇄제 및 천공 홀의 배치에 따른 영향을 최소요구팽창압 관점에서 분석하였다. 더 나아가서 비폭성 파쇄제가 채워지지 않은 천공 홀이 비폭성 파쇄 공정에 미치는 영향을 분석하고, 분리 조각의 수를 증가시켜 파쇄도를 향상시키기 위한 비폭성 파쇄제 및 천공 홀의 효과적인 배치에 대하여 고찰하였다.

• 한국재료학회지
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• 제14권4호
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• pp.235-238
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• 2004

The LT-MBE (low temperature molecular beam epitaxy) allows to dope GaAs with Mn over its solubility limit. A 75 urn thick GaMnAs layers are grown on a low temperature grown LT-GaAs buffer layer at a substrate temperature of $260^{\circ}C$ by varying Mn contents ranged from 0.03 to 0.05. The typical growth rate for GaMnAs layer is fixed at 0.97 $\mu\textrm{m}$/h and the V/III ratio is varied from 25 to 34. The electrical and magnetic properties are investigated by Hall effect and superconducting quantum interference device(SQUID) measurements, respectively. Double crystal X-ray diffraction(DCXRD) is also performed to investigate the crystallinity of GaMnAs layers. The $T_{c}$ of the $Ga_{l-x}$ /$Mn_{x}$ As films grown by LT-MBE are enhanced from 38 K to 65 K as x increases from 0.03 into 0.05 whereas the $T_{c}$ becomes lower to 45 K when the V/III ratio increases up to 34 at the same composition of x=0.05. This means that the ferromagnetic exchange coupling between Mn-ion and a hole is affected by the growth condition of the enhanced V/III ratio in which the excess-As and As-antisite defects may be easily incorporated into GaMnAs layer.

• 한국식품조리과학회지
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• 제21권3호
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• pp.326-338
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• 2005

The purpose of this study was to investigate the effect of isolate soybean protein (ISP) and rice flour on the characteristics of rice noodles. As the levels of ISP and rice flour increased, water binding capacity, swelling power of rice noodle increased. In RVA, pasting temperature, Set back showed an increasing tendency with peak viscosity, holding viscosity, break down, final viscosity of rice noodle increased as the level of rice flour by decreasing. Peak time was not significant. The weight, water absorption and volume of the cooked noodles were decreased. The turbidity of rice noodle increased. The Hunter color L, a-values of the dried rice noodle decreased. Cooked rice noodle quality increased with by decreasing the level of rice flour level. B-values of dried rice noodle and cooked rice noodle increased. Texture profile analysis of cooked rice noodle showed an increase of hardness. Adhesiveness, cohesiveness of cooked rice noodles decreased with by decreasing the level of ISP and rice flour. Gumminess, springiness, chewiness were increased. Sensory evaluation, showed gloss was increased. Hardness and chewiness of the cooked ice noodles were increased. Adhesiveness was not significant. Color and overall- acceptability were increased. Relationship between sensory and mechanical examinations (The overall quality of sensory examination for gloss) had a negative correlation with the mechanical examination for b-value (p.0.05). Mechanical examination for b-value had a positive correlation of sensory evaluation for hardness, chewiness, which had negative correlation of sensory evaluation for color. Scanning Electron, Microscopes observation of rice noodle was showed that the size of the hole grown was increased with by increasing the level of rice flour. From the above results, the most advisable mixture ratio of rice noodle evaluation was can be derived as follows: 171g rice flour, 114g wheat flour, 15g soybean protein isolate, 120ml water, and 6g salt.

• 한국지역지리학회지
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• 제11권6호
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• pp.517-529
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• 2005

연간 1,600여만 명이 찾는 대구 앞산에는 10여 개의 골짜기가 분포하며, 골짜기를 따라 이어지는 등산로에서는 다양한 지형 관찰이 가능하다. 본 연구에서는 탐방객들의 접근성과 지형자원 볼거리 면에서 세 곳의 골짜기(고산골.안지랑골.달비골)를 대상으로 지오투어리즘(geo-tourism) 관점에서 지형관찰 학습장 및 탐방로를 조성하여 보았다. 1) 앞산에서 볼 수 있는 대표적인 지형은 하식애, 풍화동굴, 수직암벽, 건열화석, 연흔화석, 습곡지형, 판상절리지형, 너덜지대, 선상지, 돌개구멍, 단층선, 가마솥바위, 주상절리지형, 변성암 등이다. 2) 앞산에서 볼 수 있는 지형을 대상으로 일반인도 이해할 수 있을 정도 수준의 설명문을 개발하였다. 3) 탐방객들의 학습효과를 높이기 위하여 골짜기별, 탐방객 체류 시간별로 아홉 가지의 지형관찰 탐방로를 개발하였다.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.957-967
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• 2018

A novel $g-C_3N_4$/ZnO/stellerite (CNZOS) hybrid photocatalyst, which was synthesized by coupled hydro thermal-thermal polymerization processing, was applied as an efficient visible-light-driven photocatalyst against Staphylococcus aureus. The optimum synthesized hybrid photocatalyst showed a sandwich structure morphology with layered $g-C_3N_4$ (doping amount: 40 wt%) deposited onto micron-sized ZnO/stellerite particles (ZnO average diameter: ~18 nm). It had a narrowing band gap (2.48 eV) and enlarged specific surface area ($23.05m^2/g$). The semiconductor heterojunction effect from ZnO to $g-C_3N_4$ leads to intensive absorption of the visible region and rapid separation of the photogenerated electron-hole pairs. In this study, CNZOS showed better photocatalytic disinfection efficiency than $g-C_3N_4/ZnO$ powders. The disinfection mechanism was systematically investigated by scavenger-quenching methods, indicating the important role of $H_2O_2$ in both systems. Furthermore, $h^+$ was demonstrated as another important radical in oxidative inactivation of the CNZOS system. In respect of the great disinfection efficiency and practicability, the CNZOS heterojunction photocatalyst may offer many disinfection applications.