• 한국수소및신에너지학회논문집
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• 제31권6호
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• pp.530-545
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• 2020

This paper reviews and summarizes the fuel-cell-related studies those have been recently published in major Korean Citation Index journals, aiming at analyzing the research trend in fuel cell technologies. Six major journals are selected for the literature survey; 57 papers are chosen for the detailed analysis through a screening examination on the total 1,040 papers published during between 2018 and 2020. Papers are classified into six technical categories, such as i) electrode, ii) electrolyte, iii) bipolar plate and stack, iv) fuel cell system, v) balance of plant, and vi) diagnosis-related studies, and summarized by the experts in the relevant area. Through this paper, we provide a comprehensive review on the recent trends and progress in fuel-cell-related research work in Korea.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.405-411
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• 2010

A 5kW class SOFC cogeneration system consisted of a hot box part, a cold BOP (balance of plant) part, and a hot water reservoir. The hot box part contained a stack, a fuel reformer, a catalytic combustor, and heat exchangers. A cold BOP part was composed of blowers, pumps, a water trap, and system control units. A 5kW stack was designed to integrate 2 sub-modules. In this paper, the 5kW class SOFC system was operated using 2 short stacks connected in parallel to test the sub-module and the system. A short stack had 15 cells with $15{\times}15 cm^2$ area. When a natural gas was used, the total power was about 1.38 kW at 120A. Because the sub-modules were connected in parallel and current was loaded using a DC load, voltages of sub-modules were same and the currents were distributed according to the resistance of sub-modules. The voltage of the first stack was 11.46 V at 61A and the voltage of the second stack was 11.49V at 59A.

• 신재생에너지
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• 제3권2호
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• pp.60-67
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• 2007

This paper describes the design and integration of the wind-fuel cell hybrid system. The hybrid system components included a wind turbine, an electrolyzer (for generation of H2), a PEMFC (Proton Exchange Membrane Fuel Cell), hydrogen storage tank and BOP (Balance of Plant) system. The energy input is entirely provided by a wind turbine. A DC-DC converter controls the power input to the electrolyzer, which produces hydrogen and oxygen form water. The hydrogen used the fuel for the PEMFC. Hydrogen may be produced and stored in high pressure tank by hydrogen gas booster system. Wind conditions are changing with time of day, season and year. So, wind power is a variable energy source. The main purpose with these WT-FC hybrid system is to store hydrogen by electrolysis of water when wind conditions are good and release the stored hydrog en to supply the fuelcell when wind is low.

• BMB Reports
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• 제45권6호
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• pp.342-347
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• 2012

Plant mitochondria possess alternative respiratory pathways mediated by the type II NAD(P)H dehydrogenases and alternative oxidases. Here, E3 SUMO ligase was shown to regulate alternative respiratory pathways and to participate in the maintenance of carbon and nitrogen balance in Arabidopsis. The transcript abundance of the type II NAD(P)H dehydrogenases NDA2 and NDB2 and alternative oxidases AOX1a and AOX1d genes was low in siz1-2 mutants compared to that in wild-type. The addition of nitrate or ammonium resulted in a decrease or an increase in the expression of the same gene families, respectively, in both wild-type and siz1-2 mutants. The amount of free sugar (glucose, fructose and sucrose) was lower in siz1-2 mutants than that in wild-type. These results indicate that low nitrate reductase activity due to the AtSIZ1 mutation is correlated with an overall decrease in alternative respiration and with a low carbohydrate content to maintain the carbon to nitrogen ratio in siz1-2 mutants.

• 동아시아식생활학회지
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• 제7권1호
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• pp.13-20
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• 1997

This study was designed to determine the effects of protein sources on the curation of gastric ulceration, protein metabolism, and nitrogen balance in rats with gastric ulcer induce by restraint and water immersion stress. After the rats were fed 10% casein diet for 3 weeks, four groups of the rats were forced in 5$\times$5$\times$15cm plexiglass cage. The restraint and water immersion stress was carried at 20$\pm$2$^{\circ}C$ for 8-hour. The other one group(control group) was not exposed to stress. After stress 4 kinds of different diets containing 20% protein were given for 5 days. The protein sources were casein, whey protein, soy protein, gluten. The control group was fed to 10% casein diet. The results were as follows ; the weights of rats were not different among the diet groups During the experiment period follows ; the weights of rats were not different among the diet groups during the experiment period (for 5 days). The ulcer index of rats fed 10% gluten and soy protein diet was significantly higher than those of casein and whey protein diet groups(p<0.05). The level of serum albumin was not significantly different among diet groups. But hematocrit and the level of $\alpha$-amino-N, BU and UUN of plant protein diet groups were higher than animal diet groups, the urinary hydroxyproline of soy protein group was the highest and the whey protein was the lowest. The digestibility and BV of nitrogen of gluten diet group were significantly higher than those of casein and whey protein diet groups(p<0.05). The animal proteins had more curative effects of ulcer than plant animals. The results of this study provide useful information concerning diet therapy for the patients with gastrointestinal diseases and the field of enteral diet materials.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.643-650
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• 2009

Two metabolism trials were conducted with 24 wether lambs to investigate the effects of feeding crab meal and other protein supplements on N utilization, digestibility and Ca and P balance in sheep. The lambs (avg. BW, 25 kg) were randomly allotted to eight diets in each of two trials. The supplements were: i) none, negative control (NC); ii) soybean meal (SBM), control; iii) supplement based on industrial byproducts of both plant and animal origin (IPA); iv) experimental supplement based on byproducts of animal origin (ESA); v) hydrolyzed supplement No 4. (HESA); vi) commercial supplement based on animal protein (CS), $Pro-Lak^{(R)}$ vii) crab meal (CM); and viii) urea (U). The supplements supplied 33% of the total dietary N (CP, 9.8%; DM basis). Lambs fed the NC diet had lower (p<0.05) DM and OM digestibility. Lower (p<0.05) apparent absorption of N was recorded for the lambs fed the HESA and NC diets. Sheep fed CM had lower Ca absorption compared to SBM. Highest (p<0.05) P absorption was observed for lambs fed CS and CM and lowest for U and NC diets. Sheep fed CM had higher (p<0.05) total VFA concentration (65.7 ${\mu}mol/ml$), compared to those fed ESA, CS, and NC diets (47.3, 49.8, and 49.5 ${\mu}mol/ml$, respectively). Highest (p<0.05) ruminal $NH_3$ N (29.6 mg/dl) was observed in lambs fed the U diet, while those fed the NC diet had the lowest (p<0.05) average value (7.66 mg/dl). Lambs fed the U diet had the highest (p<0.05) blood urea N (10.67 mg/dl). The present study showed that N utilization of diets supplemented with experimental supplements based on feather meal and blood meal; commercial supplement based on animal protein, $Prolak^{(R)}$ supplement based on plant protein and blood meal; and crab meal are comparable with that of soybean meal.

• 한국해양학회지:바다
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• 제29권1호
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• pp.28-41
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• 2024

탄소수지는 다양한 환경조건에서 식물의 생리적 상태를 평가할 수 있는 중요한 지표 중 하나이다. 우리 동해 연안에 분포하는 새우말의 수온 변화(5-30℃)에 따른 광합성률과 호흡률을 측정하여, 전체 식물 탄소수지의 계절적 변동을 추정하였다. 수온 처리에 따라 최대총광합성률은 유의한 차이를 보였지만, 광합성 효율은 유의한 차이를 보이지 않았다. 새우말의 최대총광합성률은 수온이 상승함에 따라 증가하여 20℃에서 최대값(101.65 μmol O₂ g^-1 DW h^-1)을 보인 후 30℃에서 급격히 감소하였다. 수온 변화에 따른 새우말의 포화광도, 보상광도와 호흡률은 모두 유의한 차이를 보였다. 새우말의 포화광도는 20-25℃까지(121.59-124.50 μmol photons m^-2 s^-1) 증가하다가 30℃에서 급격히 감소하였다. 보상광도와 호흡률은 수온이 증가할수록 점차 증가하였다. 최대총광합성률과 호흡률의 비율은 5℃에서 가장 높았고, 30℃에서 급격히 감소하였다. 광합성 매개변수, 호흡률 및 생체량을 통해서 추정된 새우말 전체 식물의 탄소수지는 겨울과 봄에 증가하고, 여름과 가을에 감소하는 뚜렷한 계절적 경향을 보였으며, 봄에 생장이 가장 활발하고, 수온이 가장 높은 시기에 급격히 감소하는 새우말의 생장 패턴과 일치하였다. 새우말은 늦여름부터 겨울까지 음의 탄소수지를, 봄에서 초여름까지 양의 탄소수지를 보였다. 기후 변화에 의한 지속적인 수온 상승은 우리 동해 연안 암반생태계에 분포하는 잘피생육지의 구조와 기능에 영향을 미칠 것으로 판단된다.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.539-548
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• 2010

Potassium ($K^+$) is one of the most abundant cations in higher plant. It comprises about 10% of plant dry weight and it plays roles in numerous functions such as osmo- and turgor regulation, charge balance of plasma membrane and control of stomata and organ movement. Several potassium transporters and potassium channels regulate $K^+$ homeostasis in response to $K^+$ uptake systems. In this review, we describe the biological, biochemical and physiological characteristics of shaker like potassium channels in higher plant. Especially, we searched the rice genome databases and analysized expressed genes, genome structures and protein domain characteristics of shaker like potassium channels.

• Journal of the Korean Wood Science and Technology
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• 제36권4호
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• pp.102-108
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• 2008

현재 메인 주립대학에서는 펄프용 목재 성분 중 헤미셀룰로오스 추출 기술에 관한 연구개발이 한창 진행 중이다. 펄프의 수율 향상과 용액 회수에 필요한 유기 및 무기물 사용을 줄이고 새로운 바이오 물질 생산에 필요한 도입부 추가 공정이 연구의 핵심이다. 바이오 물질 중 경제적으로 상용 가능한 에탄올 생산(pilot-scale)에 있어 전 처리되지 않은 기질, 전 처리된 기질 및 펄핑 선 추출액의 화학적 성분분석은 아주 중요한 공정이다. HPLC (High Performance Liquid Chromatography)를 이용한 펄프목재 성분분석 결과, H-column으로 분석한 총 물질수지(total analytical mass balance)는 전 처리되지 않은 칩의 경우 100.6%, 전 처리된 목재 칩은 100.3%, 그리고 펄핑 선 추출액은 81.6%의 결과를 보였다. 한편, P-column으로 분석한 결과, 전 처리되지 않은 기질, 전 처리된 기질, 그리고 선 추출액은 각각, 97.8%, 97.4%, 그리고 80.7%로 나타났다. 총 물질수지가 100%를 넘거나 부족한 수치는 분석해석 중 발생한 약간의 오류로 보인다. 펄프-바이오리파이너리(Biorefinery) 공정을 통해 생성된 기질(substrate) 각각의 정확한 성분분석 결과는 에탄올 상용화 공정에 필요한 중요한 자료가 될 것으로 기대한다.

• 한국수소및신에너지학회논문집
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• 제29권5호
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• pp.466-472
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• 2018

The investigation of cryogenic liquid pool spreading is an essential procedure to assess the hazard of cryogenic liquid usage. In this experimental study, to measure the evaporation velocity when the pool is spreading, liquid nitrogen was continuously released onto unconfined concrete ground. Almost all of the reported results are based on a non-spreading pool in which cryogenic liquid is instantaneously poured onto bounded ground for a very short period of time. A simultaneous measurement of the pool location using thermocouples and of the pool mass using a digital balance was carried out to measure the evaporation velocity and the pool radius. A greater release flow rate was found to result in a greater average evaporation velocity, and the evaporation velocity decreased with the spreading time and the pool radius.