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        검색결과 677

        203.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        legumes and rye on paddy field at the experimental field of Jeollanam-Do Agricultural Research and Extension Services from 2004 to 2008. The five treatments used in this experiment were rye mono (C.V. Koolgrazer), rye+chinese milk vetch mixture, rye+crimson clover (C.V. Linkarus) mixture, rye+forage pea (C.V. Austrian pea) mixture, rye+hairy vetch (C.V. Oregon Common) mixture. The dry matter (DM) percentage at harvest was 23. 0~25.3%. The DM percentage among rye single and mixture treatments were similar. The yields of fresh and crude protein (CP) were high in Italian ryegrass (IRG)+Forage pea mixtures as a 50,370 kg and 1,177 kg per ha. And the yields of dry matter were high in IRG+forage pea was at mixtures as a 12,390 kg/ha. The Av. P2O5 in IRG+forage pea mixture was 85 ㎎/㎏. In conclusion, the mixture cultivation of rye and forage pea was very effective
        4,000원
        205.
        2010.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Changes in surface morphology and roughness of dc sputtered ZnO:Al/Ag back reflectors by varying the deposition temperature and their influence on the performance of flexible silicon thin film solar cells were systematically investigated. By increasing the deposition temperature from 25˚C to 500˚C, the grain size of Ag thin films increased from 100 nm to 1000 nm and the grain size distribution became irregular, which resulted in an increment of surface roughness from 6.6 nm to 46.6 nm. Even after the 100 nm thick ZnO:Al film deposition, the surface morphology and roughness of the ZnO:Al/Ag double structured back reflectors were the same as those of the Ag layers, meaning that the ZnO:Al films were deposited conformally on the Ag films without unnecessary changes in the surfacefeatures. The diffused reflectance of the back reflectors improved significantly with the increasing grain size and surface roughness of the Ag films, and in particular, an enhanced diffused reflectance in the long wavelength over 800 nm was observed in the Ag back reflectors deposited at 500˚C, which had an irregular grain size distribution of 200-1000 nm and large surface roughness. The improved light scattering properties on the rough ZnO:Al/Ag back reflector surfaces led to an increase of light trapping in the solar cells, and this resulted in a noticeable improvement in the Jsc values from 9.94 mA/cm2 for the flat Ag back reflector at 25˚C to 13.36 mA/cm2 for the rough one at 500˚C. A conversion efficiency of 7.60% (Voc = 0.93, Jsc = 13.36 mA/cm2, FF = 61%) was achieved in the flexible silicon thin film solar cells at this moment.
        4,000원
        208.
        2010.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Adsorption of a water molecule on a Si (001) surface and its dissociation were studied using density functional theory to study the distribution of -OH fragments on the Si surface. The Si (001) surface was composed of Si dimers, which buckle in a zigzag pattern below the order-disorder transition temperature to reduce the surface energy. When a water molecule approached the Si surface, the O atom of the water molecule favored the down-buckled Si atom, and the H atom of the water molecule favored the up-buckled Si atom. This is explained by the attractions between the negatively charged O of the water and the positively charged down-buckled Si atom and between the positively charged H of the water and the negatively charged up-buckled Si atom. Following the adsorption of the first water molecule on the surface, a second water molecule adsorbed on either the inter-dimer or intra-dimer site of the Si dimer. The dipole-dipole interaction of the two adsorbed water molecules led to the formation of the water dimer, and the dissociation of the water molecules occurred easily below the order-disorder transition temperature. Therefore, the 1/2 monolayer of -OH on the water-terminated Si (001) surface shows a regular distribution. The results shed light on the atomic layer deposition process of alternate gate dielectric materials, such as HfO2.
        4,000원
        209.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 방화곤충에 의해 유전자변형 작물로부터 비변형작물로의 유전자 이동이 일어날 수 있는가를 조사하기 위한 프로토콜을 개발하는 것이다. 이를 위해 제초제저항성 형질전환 콩과 재배콩인 태광콩, 그리고 G. soja 시험구에서 발생하는 곤충상을 sweeping법으로 조사하였으며, 이들 시험구에서 화분매개 가능성을 가진 방화벌의 시간대별 출현빈도 및 부위별 화분 부착율을 조사하였다. 또한 채집한 서양종꿀벌로부터 부착된 화분을 이용, 핵산을 추출하고 PCR 증폭 가능성 여부를 분석하였다. 그 결과, 유전자변형 콩과 비변형 콩 사이의 곤충상에는 시기별로 유의성 있는 차이는 없는 것으로 조사되었다. 개화기 콩 꽃에서 서양종꿀벌의 출현빈도는 정오에 가장 높은 것으로 나타났다. 이들이 수확한 화분으로부터 핵산을 추출하여 PCR 을 수행하였을 때 lectin 유전자가 증폭된 것으로 보아 이들 화분은 콩으로부터 유래한 것임을 확인하였다.
        4,000원
        210.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        벼는 세계 인구의 절반이상의 안정적 식량으로 가장 중요한 식량자원이라고 할 수 있으며, 미래의 품종육종을 위해 사라져가는 재래종 자원과 벼생산에 영향을 미칠 생물적, 무생물적 스트레스에 조화를 이룰 수 있는 근연야생종을 보존하고자 1977년 국제미작연구소내에 종자은행을 설립하였다. 현재 123개국으로부터 109,000여점의 유전자원을 확보하여 보존하고 있으며, 야생종 자원도 5,000여점 포함되어있다. T.T. Chang GRC에 새로 도입된 종자는 IRRI내의 SHU(Seed Health Unit)에서 검역을 마친 후 증식을 수행할 수 있다. 증식은 주로 건기에 실시하며 생태형, 원산지, 광감수성 유무 등을 고려하여 파종기와 수확기를 달리함으로서 충실한 종자를 확보하는데 주력하고 있다. 증식된 벼 종자는 건조를 거쳐 active collection 과 base collection 으로 나누어 보존하며, 안전중복보존을 위하여 제3국인 스발바르국제저장고와 미국의 국립유전자원보존센터에도 보존하고 있다. 보존자원의 종자량, 발아율 모니터링을 통하여 갱신을 결정한다. 보존된 자원은 연구목적으로 분양 및 교환을 통하여 활용된다. 유전자원의 정보관리는 GRIMS(Genetic Resources Information Management System)로 운영되고 있다.
        4,000원
        211.
        2010.09 구독 인증기관 무료, 개인회원 유료
        This study was carried out between 2008 and 2009 in four dairy farms to investigate the effect of feeding of whole crop barley silage on the reproductive performance of Holstein heifers. Two diets, mixed hay or whole crop barley silage separately from concentrate were fed 6-month old Holstein heifers (=37). In control group (=CON), heifers (n=16) were fed 6 kg (/head) mixed hay and 4 kg (/head) commercial diet. In whole crop barley silage group (=WBS), heifers (n=21) were fed 10 kg (/head) whole crop barley silage, 4 kg (/head) mixed hay and 2 kg (/head) commercial diet. To manage body weight gain, the body condition score of heifers were measured every month. The results obtained were as follows: 1. Body weight in CON and WBS heifers at 13-, 14-, 15- and 17-month old were 340±17.9 and 342±13.6 kg, 356±15.7 and 366±14.7 kg, 382±13.1 and 387±14.4 kg, and 429±15.0 and 417±10.3 kg, respectively. 2. Body condition score in CON and WBS heifers at 9-, 12-, 15- and 17-month old were 2.88±0.04 and 2.80±0.04, 2.88±0.04 and 2.80±0.04, 2.89±0.08 and 3.00±0.07, and 2.89±0.08 and 3.00±0.07, respectively. 3. Average age of sexual maturity in CON and WBS heifers were 437.3±9.9days and 939.6±12.5days, WBS group heifers were significantly shorter (p<0.05) than CON group heifers. 4. First-service conception rates in CON or WBS group were 81.3% (13/16) and 66.7% (14/21), respectively, and cumulative conception rate to 2nd artificial insemination were 87.5% for CON and 85.7% for WBS group. Conception rate was not different between treatments
        4,000원
        212.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        농업유전자원의 그동안 활용상황을 리뷰를 통하여 살펴보고 금후의 적극적인 활용방안을 모색하기 위하여 해방후 한국 농업의 시대적 변천에 따른 농업특성과 유전자원의 활용 상황, 국가농업유전자원은행의 역할과 금후 유전자원의 활용 전망에 대하여 검토하여 본 바를 요약하면 다음과 같다. 1. 해방이후 우리나라 농업의 시대적 변천상황은 1960년대 이전은 자급형 영세농업의 시대로서 한국고유 재래종 위주 재배에서 외국품종 도입 및 국내품종 육성초기의 시대였고, 1960~1970년대는 국가적 식량문제 해결시대로서 통일벼 육성·보급 재배에 따라 다수성 품종육성을 위한 유전자원의 필요성이 대두되었고, 1980~1990년대는 농산물 소비 다양화시대로서 엽채류, 과채류의 이용성 증가로 4계절 재배가 가능한 원예작물의 육성 및 보급이 이루어졌으며, 2000년대 이후는 고부가 가치 농업을 추구하는 시대로 변천하였으며 시대적 변천에 의한 고품질, 기능성 작물재배가 증가함에 따라 다양한 형질의 유전자원 및 수출경쟁력 있는 품종을 요구하고 있다. 2. 농촌진흥청은 국가 농업유전자원 종합관리를 위하여 농업유전자원 관리기관 91개소를 지정운영 하는 등 국내외적으로 역할을 확대하고 있으며, 식물종자유전자원을 중기 및 장기보존 각각 50만점 저장이 가능한 첨단시설을 갖추고 현재 종자자원 16만점을 보존하고 있으며, 이들 유전자원을 활용하여 2,477품종을 개발하여 보급하였다. 3. 국가 농업유전자원은행의 주요 역할을 요약하면, 국내 보존유전자원을 체계적으로 관리하고 국제적 흐름에 대응할 수 있도록 하는 국가 농업유전자원의 종합관리가 첫 번째 역할이고, 두 번째는 국가 유전자원은행(Genebank) 사업으로 국내외로부터 현재 및 미래가치에 의한 유용한 유전자원의 다양성 확보, 확보한 유전자원의 증식 및 특성평가, 안전한 보존관리 및 분양서비스에 의한 활용이며, 세 번째는 유전자원 관련 기술개발 연구로서 다양성 분석, 종자수명 및 보존기술, 증식 및 특성평가 기술, 기능성 및 유용 유전자 이용을 위한 탐색기술 개발 연구 등이고, 네 번째는 국내외 협력체계를 구축하여 관련분야 및 국제적으로 대응하는 역할로서 국가를 대표하고 국격을 높이는 주요 기능을 하여야 한다. 4. 농업유전자원의 금후 활용전망을 살펴보면 경쟁력 있는 최고의 농산물 생산에 지속적으로 기여할 것이고, 안정적인 식량공급과 국민의 참살이 수요를 충족하는 기본자원으로 활용되며, 농촌환경 생태계를 건전하고 윤택하게 보존하는데 활용되고, 에너지, 신물질, 신소재 등 차세대 성장동력원 창출의 원천 자원이 될 것이다.
        4,000원
        215.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Substantial efforts have been made to manipulate ruminal environment in a hope to enhance ruminal fermentation efficiency for better ruminant productivity. Some of examples are methane inhibitors, antibiotics, microbial enzymes, fatty acids and/or lipid feeding, buffering agents, ionophores and probiotics. Of these efforts, the non-ionic surfactant (NIS) has been known for its stimulation to release enzymes from a range of anaerobic microbes. A series of studies were conducted 1) to evaluate NIS diluted with water and ethanol on in vitro ruminal fermentation and 2) to determine the influence of diluted NIS on digestibility of feedstuffs. In first experiment (Exp. 1), NIS was diluted with water or ethanol to measure its effects on in vitro microbial growth, ruminal enzyme activities and gas production by mixed ruminal microbial culture. The NIS was diluted with water or ethanol separately in a 1:5 ratio (w/v). Water and ethanol-diluted NIS with wheat flour were added with rice straw-based mixed ruminal microbial cultures at the rate of 2 ㎎ NIS/16 ㎖ McDougall buffer plus 4 ml ruminal fluid solution. The mixed ruminal microbial culture was run without any NIS addition as control. Addition of NIS either diluted with water or ethanol has significantly reduced the gas production in mixed ruminal microbial culture at 12 and 24 h of incubation. At 48 h post incubation, gas production was the highest with the addition of ethanol diluted NIS followed by water-diluted NIS and control. Carboxy methyl cellulase activity in rice straw-based mixed ruminal bacterial culture was significantly higher with the addition of ethanol-diluted NIS compared with the addition of water-diluted NIS and control at 24 and 72 h post incubation. In second in vitro experiment (Exp. 2), effects of addition of ethanol diluted NIS on dry matter (DM) digestibility of alfalfa hay, gas production, pH and cellular growth in mixed ruminal microbial culture were examined. Alfalfa hay based mixed ruminal microbial culture without any NIS addition was run as a control. The pH of mixed ruminal microbial culture was significantly lower than control at all post incubation sampling hours. In vitro DM digestibility of alfalfa hay was significantly higher with the addition of NIS compared with control. Gas production was significantly less with NIS addition compared with control at all post incubation sampling hours. Microbial growth in mixed ruminal microbial culture was significantly increased with the addition of NIS compared to control.
        4,000원
        218.
        2010.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A fiber fraction (Aloe cellulose), the by-product obtained from Aloe vera gel processing was freeze dried and investigated for in vitro glucose/ bile acid retarding effects of powdered sample (100 mesh) comparing with commercial α-cellulose as a reference sample. We also examined the effectiveness of physiological functionality such as the antiobesity and anti-constipation on Sprague-Dawley (SD) rat. The Aloe cellulose powders during in vitro dialysis experiment for 2 hours exhibited the glucose and bile acid retarding index of 20.32-35.2% and 53.13-28.30%, respectively. Especially, freeze dried aloe cellulose showed the 2.5 and 1.2-6 times higher effect on in vitro glucose and bile acid retardation than those of α-cellulose. These relatively good retarding effects on glucose and bile acid diffusion suggest a potential of preventing from diabetes and arteriosclerosis of some extent. Also, the results from animal experiments on SD rats fed a high-fat diet for 4 weeks suggested that Aloe cellulose might be used as a novel dietary fiber showing an effective anti-obesity and anti-constipation effect.
        4,000원