• 한국식품저장유통학회지
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• 제17권1호
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• pp.139-144
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• 2010

난대성 상록활엽수종의 자원화 및 식품 소재화 탐색을 목적으로 구실잣밤나무(Castanopsis cuspidata var. sieboldii $N_{AKAI}$) 열매(구실잣밤) 추출물의 수율, pH, 당도, 색도, 구성당, 유기산 함량, 페놀 함량 및 항산화활성을 검정하였다. 각 용매에 대한 추출물의 수율은 물 추출물에서 3.6%로 가장 높았고, pH는 6.43의 중성값을 보였으며, 당도는 3.17 $^{\circ}Brix$를 나타내었다. 색도 중 L값은 83.07, a값은 1.49 그리고 b값은 10.48을 나타내었다. 구성당의 조성 및 함량은 fructose 27.11 mg%, glucose 26.29 mg%, galactose 0.86 mg%로 나타났다. 유기산은 총 5종이 동정되었으며, oxalic acid(59.44%), formic acid (23.99%), malic acid (11.24%), citric acid (3.34%), succinic acid (1.99%) 순으로 나타났다. 총 페놀 함량은 물 추출물에서 27.69 mg% 수준으로 가장 높았고, DPPH radical-scavenging 활성은 대조구인 $\alpha$-tocopherol ($SC_{50}\;12.47{\mu}g/mL$)에 비해 낮은 수준이었으나 EtOAc 추출물($SC_{50}\;74.88{\mu}g/mL$)에서 가장 강한 활성을 보였다. 이와 같은 결과를 바탕으로 구실잣밤은 다양한 식품소재 및 기능성 소재로서의 활용성이 기대되었으며, 또 도토리의 대용 및 병용이 가능한 소재로서 실용화 가능성이 확인되었다.

• KEPCO Journal on Electric Power and Energy
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• 제2권3호
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• pp.447-452
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• 2016

It is imperative to develop an effective pathway to depolymerize lignin into liquid fuel that can be used as a bioheavy oil. Lignin can be converted into liquid products either by a solvent-free thermal cracking in the absence air, or thermo-chemical degradation in the presence of suitable solvents and chemicals. Here we show that the solvent-assisted liquefaction has produced promising results in the presence of metal-based catalysts. The supercritical ethanol is an efficient liquefaction solvent, which not only provides better solubility to lignin, but also scavenges the intermediate species. The concentrated sulfuric acid hydrolysis lignin (CSAHL) was completely liquefied in the presence of solid catalysts (Ni, Pd and Ru) with no char formation. The effective deoxy-liquefaction nature associated with scEtOH with aid hydrodeoxygenation catalysts, resulted in significant reduction in oxygen-to-carbon (O/C) molar ratio up to 61%. The decrease in oxygen content and increase in carbon and hydrogen contents increased the calorific value bio-oil, with higher heating value (HHV) of $34.6MJ{\cdot}Kg^{-1}$. The overall process is energetically efficient with 129.8% energy recovery (ER) and 70.8% energy efficiency (EE). The GC-TOF/MS analysis of bio-oil shows that the bio-oil mainly consists of monomeric species such as phenols, esters, furans, alcohols, and traces of aliphatic hydrocarbons. The bio-oil produced has better flow properties, low molecular weight, and high aromaticity.

• 한국분무공학회지
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• 제23권3호
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• pp.136-148
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• 2018

Major countries have tighten their NOx regulation of diesel passenger cars. In the case of the EU, the regulation has been toughen up to 6.25 times since 2000. Despite the regulation the NOx concentration of the ambient has not been reduced proportionally. As these issues, to reduce NOx emission practically, Korea and the EU introduced the real-world driving emission (RDE) regulation and the test method that will be applied after 2017. In this paper, for the regulation to make a soft landing in Korea, 6 diesel passenger cars which met Euro 6a~6d regulation and were equipped with LNT/SCR were tested at a chassis dynamometer with environmental chamber applying the off-cycles (FTP, US06, SC03, HWFET and CADC) and several ambient conditions (-7 and $14^{\circ}C$) as well as certification modes (NEDC, WLTC@ $23^{\circ}C$). The result of the test showed that the ambient temp. and the engine load as a test mode impacted the NOx emission of the cars while the vehicles with SCR emitted NOx lower than with LNT. Additionally, to propose an effective RDE test method, the above result was compared with the results of the other papers which tested RDE using the same cars.

• Nuclear Engineering and Technology
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• 제48권3호
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• pp.773-777
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• 2016

A betavoltaic battery was prepared using radioactive $^{63}Ni$ attached to a three-dimensional single trenched P-N absorber. The optimum thickness of a $^{63}Ni$ layer was determined to be approximately $2{\mu}m$, considering the minimum self-shielding effect of beta particles. Electroplating of radioactive $^{63}Ni$ on a nickel (Ni) foil was carried out at a current density of $20mA/cm^2$. The difference of the short-circuit currents ($I_{sc}$) between the pre- and post-deposition of $^{63}Ni$ (16.65 MBq) on the P-N junction was 5.03 nA, as obtained from the I-V characteristics. An improved design with a sandwich structure was provided for enhancing performance.

• 한국분무공학회지
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• 제22권4호
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• pp.185-189
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• 2017

In Korea, sales of passenger cars using diesel and LPG fuels were continuously increased in recent years. From now on 2030, the registrated vehicles will close in about twenty five million in Korea. From these reason, Investigation on the comparison of exhaust emission characteristics of passenger cars using LPG and Diesel fuel in variation of driving mode and ambient conditions were conducted in this study. Exhaust emission characteristics of test vehicles were measured and analyzed by using chassis dynamometer and emission analyzer. Also, test vehicles were selected on the diesel vehicle with 1.7L engine and LPG vehicle with 2.0L engine. In order to study on emission characteristics according to driving cycles, CVS-75, NEDC, US06, SC03, Cold-FTP and HWFET were applied and the test conditions were set up the cases of A/C on and hot start. From these results, it is revealed that the NOx emission of diesel vehicle was higher than that of LPG vehicle and the case of CO emission shows the opposite patterns. In the HC emission, the emission increasing patterns not showed but the NOx emission of diesel vehicle and CO emission of LPG vehicle were showed the variation patterns according to the various driving modes.

• 한국수소및신에너지학회논문집
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• 제29권5호
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• pp.497-502
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• 2018

In Korea, passenger car and van using LPG fuel including taxi constantly increased due to the high cost of fuel. Recently, the emission standard has continuously tightened in the world. In this investigation was conducted the greenhouse gas emission characteristics of LPG vehicles according to the displacement and weight. Exhaust emission characteristics of 13 test LPG vehicles from about 1.0 L to 3.0 L displacements were measured and analyzed by using chassis dynamometer and emission analyzer. It is revealed that the greenhouse gas emission was showed the increasing tendency as the displacement and curb weight increased. Also, greenhouse gas emission of SC03 driving cycle has highest value and that of HWFET driving cycle shows the lowest value.

• 한국미생물·생명공학회지
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• 제42권2호
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• pp.152-161
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• 2014

The in vitro antimicrobial potential of the unexplored Moringa oleifera seed coat (SC) was evaluated against some Gram-positive and Gram-negative bacteria and yeast pathogens. Antimicrobial studies with various solvent extracts indicated ethyl acetate to be the best extractant, which was used for the rest of the antimicrobial studies as it tested neither toxic nor mutagenic. Gram-positive bacteria including a methicillin resistant Staphylococcus aureus (MRSA) strain were more susceptible with a minimum inhibitory concentration (MIC) range of 0.03-0.04 mg/ml. The antimicrobial pharmacodynamics of the extract exhibited both concentration-dependent and time-dependent killing. Most of the test organisms exhibited a short post antibiotic effect (PAE) except Enterococcus faecalis, Staphylococcus aureus, and Klebsiella pneumoniae 1, which exhibited longer PAEs. Amongst the major phytoconstituents established, flavonoids, diterpenes, triterpenes and cardiac glycosides exhibited inhibitory properties against most of the test organisms. The identified active phytochemicals of the M. oleifera seed coat exhibited antimicrobial potential against a wide range of medically important pathogens including the multidrug-resistant bugs. Hence, the M. oleifera seed coat, which is usually regarded as an agri-residue, could be a source of potential candidates for the development of drugs or drug leads of broad spectrum that includes multidrug-resistant bugs, which are one of the greatest concerns of the $21^{st}$ century.

• 대한건축학회논문집:구조계
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• 제34권2호
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• pp.83-90
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• 2018

This study was conducted to investigate the living environment of semi-basement housing units in multi-household houses. It analyzed measurements of temperature and humidity obtained from the housing units. For this study, temperature and humidity sensors were installed in 10 semi-basement housing units to measure interior temperature and humidity for 13 months. A survey was conducted to get information about the occurrence of dew condensation and mildew and to investigate residents' satisfaction level with the residential environment. According to the result, all the housing units under study had dew condensation and mildew. The average summer temperature of the 10 housing units was $27.84^{\circ}C$, and average humidity was 64.91%RH, while the average winter temperature was $20.6^{\circ}C$, and the average humidity was 40.12%RH. Depending on the condition of each housing unit, deviation was big. Residents' average level of satisfaction with the living condition was 2.03 which shows a low satisfaction (on a scale of 1-5 with 5 being completely satisfied.).

• 자원환경지질
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• 제42권3호
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• pp.177-193
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• 2009

삼광광상은 선캠브리아기 경기육괴의 화강편마암내에 발달된 단열대(NE, NW)를 따라 충진한 8개의 괴상맥으로 구성된 중열수 석영맥광상이다. 이 광상의 광화작용은 여러번의 단열작용에 의해 형성된 두시기의 석영+방해석시기(광화I시기)와 방해석시기(광화II시기)로 구성된다. 광화I시기의 열수작용에 의한 변질작용은 견운모화, 녹니석화, 탄산염화, 황철석화, 규화, 및 점토화작용등이 관찰되며 견운모대는 석영맥과 접촉한 부분에서 녹니석대는 석영맥으로부터 멀어짐에 따라 관찰된다. 견운모대의 모암변질광물은 대부분이 견운모 및 석영이며 일부 일라이트, 탄산염광물, 녹니석으로 구성된다. 녹니석대의 모암변질광물은 주로 녹니석, 석영과 소량 견운모, 탄산염광물 및 녹염석으로 구성된다. 견운모의 Fe/(Fe+Mg) 값은 0.45${\sim}$0.50(0.48$\pm$0.02)이며 백운모-펜자이트족에 해당되고 녹니석의 Fe/(Fe+Mg) 값은 0.74${\sim}$0.81(0.77$\pm$0.03)이고 대부분 브런스비자이트에 해당된다. 견운모와 녹니석에 대한 $Al_{IV}$-FE/(FE+Mg)의 다이어그램은 변질시 같은 광종의 견운모와 녹니석의 형성온도를 나타내는 지시자로써 유용하다. 이것은 계산된 녹니석 단종의 활동도가 $a3(Fe_5Al_2Si_3O_{10}(OH)_6$=0.0275${\sim}$0.0413, $a2(Mg_5Al_2Si_3O_{10}(OH)_6$=1.18E-10${\sim}$7.79E-7, $a1(Mg_6Si_4O_{10}(OH)_6$=4.92E-10${\sim}$9.29E-7로서 삼광광상의 녹니석은 iron-rich 녹니석으로 비교적 고온 (T>450$^{\circ}C$에서 모암과 평형상태에서 온도가 감소함에 따라 형성되었음을 알 수 있다. 모암변질시 ${\alpha}Na^+$, ${\alpha}K^+$, ${\alpha}Ca^{2+}$ 및 ${\alpha}Mg^{2+}$는 각각 ${\alpha}Na^+$=0.0476($400^{\circ}C$), 0.0863($350^{\circ}C$), ${\alpha}K^+$=0.0154($400^{\circ}C$), 0.0231($350^{\circ}C$), ${\alpha}Ca^{2+}$=2.42E-11($400^{\circ}C$), 7.07E-10($350^{\circ}C$), ${\alpha}Mg^{2+}$=1.59E-12($400^{\circ}C$), 1.77E-11($350^{\circ}C$)이며 열수용액의 pH는 5.4${\sim}$6.4($400^{\circ}C$), 5.3${\sim}$5.7($350^{\circ}C$)로서 모암변질시 열수용액는 약산성이었음을 알 수 있다. 모암변질시 이득원소(부화원소)는 $TiO_2$, $Fe_2O_3(T)$,CaO, MnO, MgO, As, Ag, Cu, Zn, Ni, Co, W, V, Br, Cs, Rb, Sc, Bi, Nb, Sb, Se, Sn 및 Lu 등이며 특히 대부분의 광상에서 Ag, As, Zn, Sc, Sb, S,$CO_2$ 등의 원소가 현저하게 증가하므로 중열수 및 천열수 금-은광상의 탐사에 지시원소로서 활용될 수 있을 것이다.

• 한국식품영양과학회지
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• 제36권6호
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• pp.683-688
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• 2007

본 실험은 성숙시기별 복분자딸기 과실부(미숙과 및 중간숙과, 완숙과)를 70% ethanol로 추출하여 항산화 원인 물질로 여겨지는 여러 유효 성분들을 조사한 후 천연 항산화제로서의 개발 가능성을 탐색하고자 하였다. 복분자딸기 100 g당 함유되어 있는 총 폴리페놀 화합물 함량은 완숙과가 4.50g으로 미숙과(2.84 g)와 중간숙과(1.55 g)에 비하여 약 2배정도 함량이 많았으며, DPPH 라디칼 소거능도 복분자딸기 과실이 성숙할수록 높은 활성을 나타냈다. SOD 유사활성도 복분자딸기가 중간숙과 80.05%, 완숙과 95.03%로 과실이 미성숙했던 시기보다 높은 활성을 가지는 것을 알 수 있었다. 100 g당 함유되어 있는 복분자딸기의 비타민 A 함량은 미숙과가 2.37 mg으로 중간숙과와 완숙과에 비하여 높았지만, 비타민 E는 완숙과가 0.9 mg으로 미숙과 0.2 mg에 비하여 높은 함량을 가진 것으로 나타났다. 복분자딸기의 비타민C 함량은 미숙과 28.55 mg, 중간숙과 23.06 mg, 완숙과 30.79 mg으로 과실의 성숙정도와 관계없이 전체적으로 높은 함량을 가지고 있었다. 플라보노이드 함량은 복분자딸기 완숙과가 $49{\mu}m/mg$로 중간숙과($16.4{\mu}m/mg$)와 미숙과($15.4{\mu}m/mg)$에 비하여 과실이 성숙할수록 함량이 크게 증가하였다. 또한 색소성분으로 여러 기능적 역할을 수행하는 안토시아닌은 미숙과일 때 7.89 mg%에 불과하였던 것이 완숙과일때 394.50 mg%로 함량이 크게 증가하였다.