• 한국세라믹학회지
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• 제53권6호
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• pp.647-651
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• 2016

SiC films were prepared on glassy carbon substrates by laser chemical vapor deposition under a high pressure of $10^4Pa$ using a diode laser (wavelength = 808 nm) and a polysilaethylene precursor. (111)-oriented SiC films were formed at a deposition temperature ($T_{dep}$) range of 1150 - 1422 K. At $T_{dep}=1262K$, the SiC film with a high Lotgering factor of above 0.96 showed an exhibited pyramid-like surface morphology and flower-like grains. The highest deposition rate ($R_{dep}$) was $220{\mu}m\;h^{-1}$ at $T_{dep}=1262K$.

• 태양에너지
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• 제6권2호
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• pp.3-14
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• 1986

It is desirable to collect the solar thermal energy at relatively high temperature in order to minimize the size of thermal storage system and to enlarge the scope of solar thermal energy utilization. In this study, to develop a solar collector that has both advantages of collecting solar thermal energy at high temperature and fixing conveniently the collector system for long term period, a cylindrical parabolique concentrating solar collector (M.C.P.C.S.C) was designed, which has several rows of parabolique reflectors and thin thickness such as the flat-plate solar collector, maintaining the optical form of concentrating solar collector. The thermal performance of the M.C.P.C.S.C. newly designed in this study was analysed theoretically and experimentally. The results are summarized as follows: 1) prediction equation for outlet temperature, $T_o$, of heat transfer fluid and for the thermal efficiency, ${\eta}$, of the collector were derived as; o $$T_o=[C+B1_n(\frac{I_c(t)}{pv^3})]T_i$$ o $${\eta}=\frac{A}{A_c}\dot{m}[(C-1)+B1_n(E{\cdot}di^6\frac{I_c(t)}{\dot{m}^3})]\frac{T_i}{I_c(t)}$$ 2) When the insolation on the tilted solar collector surface, $I_c$, was $900-950W/m^2$ and the heat transfer fluid was not circulated in tubular absorber, the maximum temperature on the absorber surface was $100-118^{\circ}C$, this result suggested that the heat transfer fluid could be heated up to $98-116^{\circ}C$. The maximum temperature on the absorber surface was decreased with the increase of the collector shape factor, $L_p/L_w$ 3) There was a good agreement between the experimental and theoretical value of solar collector efficiency, ${\eta}$, which was proportional to the collector shape factor, $L_p/L_w$ 4) It is desirable to continue the study on the relationship between the collector shape factor, $L_p/L_w$, and the thermal efficiency of solar collector.

• 생명과학회지
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• 제19권5호
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• pp.664-670
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• 2009

지방분해와 열생산에 관여한다고 알려진 ADRB3 유전자의 염기서열 분석을 통하여 한국인에서 호발하는 유전자 다형성 부위를 먼저 확인한 후 이 유전자 다형성들과 HDL-C와의 연관성에 대하여 조사하고자 2006년 5월에서 12월 사이에 부산지역의 일개 대학병원에서 건강진단을 받은 991명을 대상으로 신장, 체중, 체질량지수, 허리둘레, 고밀도 지단백 콜레스테롤, 중성지방, 공복 혈당을 측정하였으며, 대상자들의 혈액에서 DNA를 분리하여 ADRB3 유전자에서 흔히 발생하는 유전자다형성 부위를 확인하였다. 연구결과 한국인에서 ADRB3 유전자의 intron2 +3893T>C의 변이를 처음으로 발견하였으며 열성 대립형질의 발현빈도는 0.164이었다. Exon1의 +188T>C와 intron2의 +3893T>C의 열성 대립형질인 C형이 있을 경우 HDL-C의 농도가 낮았다. 따라서 ADRB 유전자 다형성은 HDL-C과 관련이 있을 것으로 생각된다.

• 한국응용과학기술학회지
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• 제27권3호
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• pp.290-299
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• 2010

The bioactive effects of ethanol extracts from fly maggot (ME) on reduction of plasma lipids levels in rats fed high-fat diets (Expt. Ⅰ), and on liver function recovery of hepatotoxicity rats by intraperitoneal injection of carbon tetrachloride ($CCl_4$) or by orally administration of alcohol (Expt. II) were investigated. In expt. I, twenty seven, male rat SDS(sprague dawley strain) were randomly assigned to three treated groups, including normal control group, HF (group with high fat diets which have no extracts) and HFE (HF plus orally administered doses of ME extract at 5.0 mg/100g of body weight). In expt. II, forty five, male rats (SDS) were randomly assigned to each of the five groups: T1 (control), T2 (intraperitoneal injection of $CCl_4$), T3 (intraperitoneal injection of $CCl_4$ after orally administered with ME), T4 (orally administered with combination of ME and alcohol), T5 (orally administration of ME after orally administered with alcohol). There were significant decreases in plasma (TAG), (TC), (LDL-C) in the HFE group with orally administered doses of ME at 5.0 mg/100g of body weight, respectively, however, the (HDL-C) were significantly increased in HFE group as compared to HF group with high fat diets which have no extracts (p<0.05). The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), ${\gamma}$-glutamyl transferse(${\gamma}$-GTP) and bilirubin were highest in T2 or T3, and high in order T4 or T5, and lowest in T1 except for bilirubin which has same with T4, T5 (p<0.05). The high recovery of liver damage by $CCl_4$ from the light microscopic appearance was observed in rats (T3) with extracts, and also high in T4 than T5 by orally administrated with alcohol. In conclusion, the ethanol extracts from fly maggot may have a bioactive effects to prevent for human lipids disorder and alcoholic disease.

• 한국습지학회지
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• 제18권3호
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• pp.286-291
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• 2016

고농도의 암모니아 함유 공장 폐수를 대상으로 마이크로버블이 발생되는 장치를 이용하여 암모니아 탈기에 의한 처리 가능성을 평가하였다. 기존 처리장은 pH를 12.5로 유지하면서 반응 조내의 온도를 $30^{\circ}C$에서 $70^{\circ}C$로 상승시켜 72시간 동안 고온 탈기 시켰을 경우 T-N의 제거효율은 70.3%에서 90.5%로 증가하였다. 온도를 $30^{\circ}C$로 유지하면서 유입수의 T-N 농도가 9,120~12,955 mg/L인 폐수를 20시간 동안 마이크로버블에 의한 지속적인 접촉으로 상온 탈기 시킨 결과 T-N 제거율을 90.5~91.9%로 확보하였으며, 운전기간 동안의 pH는 12.3에서 10.1로 소폭 감소하였다.

• 한국전기전자재료학회논문지
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• 제17권11호
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• pp.1186-1191
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• 2004

ZnO varistor ceramics which were fabricated with variation of added of 0.5～1.0 mol% Co$_3$O$_4$, were sintered at 1150 $^{\circ}C$. In the specimen added 0.7 mol% Co$_3$O$_4$, sintered density was 6.03 g/㎤ and electrical properties were superior to any other compositions. The nonlinear coefficient a and clamping voltage ratio were 83 and 1.35, respectively. But, endurance surge current in the specimen added 0.5 mol% Co$_3$O$_4$ was 7000 A/$\textrm{cm}^2$, and deviation of varistor voltage was Δ-3.23 %. As P.C.T and T.C.T environmental test were succeed in all specimens, and deviation of varistor voltage in the specimen added 0.6 mol% Co$_3$O$_4$ was Δ-0.81 %. All specimens showed good leakage current property on the High Temperature Continuous Load Test(HTCLT) for 1000 hr at 85 $^{\circ}C$ and variation rate of the varistor voltage below Δ-2.0 %.

• Preventive Nutrition and Food Science
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• 제2권4호
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• pp.333-337
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• 1997

Trans-cinnamic acid-4-hydroxylase(tC4H) is the first cytochrome P450-dependent monooxygenase of the phenylpropanoid pathway. The roots of avocado seedlings were wounded and examined to determine whether the tC4H would be activated in response to wounding and/or whether tC4H activity be modulated by the application of exogenous p-coumarate. At the specified length of times, the wounded and treated roots were either frozen in liquid nitrogen or used immediately to extract microsomal proteins. The microsomal proteins were subjected to immunoblot analysis using polyclonal antibodies against CYP73 of tC4H gene. In this study, tC4H was induced in wounded roots sealed in bags within 6 hours, and in low level({TEX}$10^{-8}${/TEX}M) of p-coumarate solution within 24 hours, whereas the olution without p-coumarate and high levels of p-coumarate solution repressed tC4H induction in wounded roots. These results indicate that tC4H is induced by wounding in the root of avocado, and is inhibited by the application of exogenous p-coumarate.

• Progress in Superconductivity
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• 제4권2호
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• pp.121-126
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• 2003

The single layer direct-coupled YBCO SQUID magnetometers have been fabricated and characterized for the purpose of the measurement of weak magnetic signals in unshielded environment. Two types of magnetometers have been designed and fabricated using 10 mm$\times$ 10 mm substrates. We could operate the conventional 3-mm-wide solid pickup loop magnetometers more stably than the 12-parallel-line pickup loop magnetometers in laboratory environment. We developed a first-order electronic gradiometer system using the SQUID sensors with axial displacement of 80 mm without any mechanical alignment of magnetometers. The system with a software filter using calculation of discrete Fourier transform could record clearly weak pulse signal of 100 pT in a magnetically disturbed environment.

• E2M - 전기 전자와 첨단 소재
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• 제9권6호
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• pp.600-604
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• 1996

High-T$_{c}$, superconducting wire is very important element for the application of electrical power systems. But it is very difficult to develope the long high T, wire with excellent properties. BiSrCaCuO multi-layer tapes are fabricated by a rolling method and pressing method sintered for several step at 840.deg. C. The critical current densities of 637 filament multi-layer tapes sintering 100 hours fabricated by the rolling method and pressing method are 1.3*10$^{4}$ A/cm$^{2}$ and 5.5*10$^{3}$ A/cm$^{2}$. The critical cur-rent densites of multi-layer tapes made by rolling method are found to be better than those fabricated by the powder-in-tube method and pressing process. As result, the rolling method is the best way to fabricated the multi-layer filament.t.

• 대한기계학회논문집A
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• 제35권6호
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• pp.609-617
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• 2011

최근 효율을 높이기 위한 플랜드의 환경이 고온, 고압으로 변화함에 따라 열하중과 기계하중을 동시에 반영한 균열 평가는 플랜트의 건전성을 위하여 반드시 필요하다. C(t)-적분은 고온 균열 평가에 있어서 천이 크리프 상태의 균열을 평가하는 중요한 요소이다. 열하중과 기계하중이 동시에 작용하는 환경에서의 C(t)-적분을 예측하는 것은 복잡하며 하중조건이 달라지는 경우에는 더욱더 복잡해진다. 본 논문에서는 열하중과 기계하중의 하중조건이 달라지는 여러 조건에 대한 C(t)-적분 평가식을 제시하였다.