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        검색결과 56

        21.
        1993.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        열경화성 에폭시 수지의 물성 중 담약성을 개선하기 위해 새로운 반응성첨가제 succinonitrile(SN)을 Diglycidy1 ether of bisphenol A(DGEBA(-4,4'-methylene dianiline(MDA)계에 도입하여 현재 널리 사용되고 있는 유리섬유 복합재료에 매트릭스로 사용될 경우에 있어서 파괴되는 거동을 미시적으로 고찰하였다. 그 결과 post debond friction 에너지가 파괴 거동을 주도하고 있으며, 다음으로 pull-out에너지 그리고 debonding 에너지 순으로 나타났다. 따라서 파괴 거동에 미치고 있는 중요한 요인은 섬유와 매트릭스 간의 경계면 전단 응력이 크게 좌우함을 알 수 있었으며, 이때 반응성 첨가제 SN은 전단응력을 떨어뜨리는 것으로 고찰되었다.
        4,000원
        22.
        1992.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Diglycidyl ether of bisphenol A (DGEBA)와 경화제로서 4, 4'-methylene dianiline(MDA) 에 반응성 첨가제 succinonitrile(SN)을 첨가한 새로운 계를 Differential Scanning Calorimetry (DSC)로 이용하여 30˚C부터 350˚C의 온도 범위에서 승온적 진행 방범(dynamic run method)으로 얻은 값을 가지고 최대 반응속도에서의 온도에 승온속도가 미치는 영향을 해석 할 수 있는 kissinger식을 적용하여 경화반응 속도론을 연구하였다. SN을 첨가한 DGEBA/MDA계의 활성화에너지 (Ea)와 pre-exponential factor(A) 그리고, SN이 첨가될 때 에폭시와 아민과의 반응속도 상수 k를 구하였다.
        4,000원
        23.
        1992.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Succinonitrile을 첨가한 새로운 에폭시 수지, diglycidyl ether of bisphenol A(DGEBA)/4, 4'-methylene dianiline(MDA)/succinonitrile(SN)계의 역학적 성질을 충격 저항실험과 응력 변형실험을 통하여 곁화반응 특성과 반응기구를 근거로 하여 고찰하였다. DGEBA/MDA계에 각각 다른 succinonitrile의 함량을 포함하는 계를 80˚C에서 1.5시간 동안 경화시킨 후 완전히 경화를 이루기 위하여 150˚C에서 1시간 동안 경화시킨 후 시험한 결과 Succinonitrile의 함량이 증가함에 따라 본 계의 충격강도는 점차적으로 증가하였으나 인장강도는 감소하였다. 그리고 Young률은 거의 일정하게 나타났으며, 신도는 succinonitrile의 함량이 10phr에서 최대값을 보였다. 본 실험으고부터 얻은 결과는 succinonitrile이 첨가됨으로써 주 사슬간의 결합길이가 연장되었기 때문임을 알았고, 적당량의 succinonitrile을 첨가함으로 에폭시 수지의 유연성이 개선됨을 알 수 있었다.
        4,000원
        24.
        2020.09 KCI 등재 서비스 종료(열람 제한)
        In a four-wheel independent drive platform, four wheels and motors are connected directly, and the rotation of the motors generates the power of the platform. It uses a skid steering system that steers based on the difference in rotational power between wheel motors. The platform can control the speed of each wheel individually and has excellent mobility on dirt roads. However, the difficulty of the straight-running is caused due to torque distribution variation in each wheel’s motor, and the direction of rotation of the wheel, and moving direction of the platform, and the difference of the platform’s target direction. This paper describes an algorithm to detect the slip generated on each wheel when a four-wheel independent drive platform is traveling in a harsh environment. When the slip is detected, a compensation control algorithm is activated to compensate the torque of the motor mounted on the platform to improve the trajectory tracking performance of the platform. The four-wheel independent drive platform developed for this study verified the algorithm. The wheel slip detection and the compensation control algorithm of the platform are expected to improve the stability of trajectory tracking.
        25.
        2019.10 서비스 종료(열람 제한)
        한국시설안전공단은 국민과 국가 주요 시설물의 안전확보를 위하여 정밀안전진단 등 시설안전 및 건설공사 안전관리 등 건설안전 임무를 수행하고 있다. 특히 점검 및 진단의 부실 예방 및 보고서의 내실화를 위하여 ‘02년도부터 시특법에 평가제도가 도입된 후 현재까지 시행되고 있다. 평가대상은 시특법 제11조의2에 따라 제출된 1·2종 점검 및 진단 실시결과를 동법 시행령 제14조에 따라 선정하고 있다. 본 고는 교량 시설물의 보고서 평가사례를 제시하여 점검·진단 시 간과하기 쉬운 사항들을 실시자가 파악함으로써 부실 예방 및 보고서 작성의 내실을 기하는데 그 목적이 있다.
        26.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 가교 분자를 사용하여 0.7 kPa에서 17.7 kPa까지 다양한 강도를 갖는 콜라겐 겔을 성공적으로 제조하였다. 가교된 콜라겐 겔에 다공성 기공을 도입하고 진피세포를 내부에 담지하여, 겔 강도에 따른 세포 성장 및 거동을 확인하였다. 상대적으로 강도가 높은 겔에서 진피세포의 프로콜라겐 생합성이 47 ng에서 32 ng까지 감소하는 것을 확인하였다. 이렇게 제조된 인공피부 진피에 아데노신을 처리하였을 때, 특정 강도를 갖는 콜라겐 겔에서 프로콜라겐 생합성이 감소하는 것을 확인하였다. 반면에 기능성 펩타이드를 처리하였을 때 는 프로콜라겐 생합성이 콜라겐 겔의 강도에 크게 영향을 받지 않는 것을 확인할 수 있었다. 이러한 결과는 강도가 제어된 인공피부 제조 및 응용, 나아가 다양한 조직공학 분야의 기반 기술로 활용 가능하리라 기대된다.
        27.
        2018.04 KCI 등재 서비스 종료(열람 제한)
        The study was performed to explore the molecular changes in the vegetative stage (3-and 5-leaf) of sorghum under waterlogging stress. A total of 74 differentially expressed protein spots were analyzed using LTQ-FT-ICR MS. Among them, 12 proteins were up-regulated and 3 proteins were down-regulated. Mass spectrometry (MS) results showed that about 50% of the proteins involved in various metabolic processes. The level of protein expression of malate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase related to carbohydrate metabolic process increased in both 3 and 5-leaf stage under waterlogging stress. These proteins are known to function as antistress agents against waterlogging stress. The expression of oxygen-evolving enhancer protein 1 protein related to photosynthesis was slightly increased in the treated group than in the control group, however the expression level was increased in the 5-leaf stage compared to the 3-leaf stage. Probable phospholipid hydroperoxide glutathione peroxidase protein and superoxide dismutase protein related to response to oxidative stress showed the highest expression level in 5-leaf stage treatment. This suggests that the production of reactive oxygen species by the waterlogging stress was the most abundant in the 5-leaf treatment group, and the expression of the antioxidant defense protein was increased.
        28.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        Yellow alkaline noodles were prepared with various Korean wheat cultivars including different protein and amylose contents and made from two types of noodle machines. Korean food companies and restaurants generally used noodle machine made in Korea, whereas research institutes mainly practiced with noodle machine made in Japan. Noodle dough sheet from Korean machine showed 5% higher water absorption and 30 min shorter resting period than the noodle dough from Japanese machine because of the difference of size and weight of roller in two types of the machines. In 15 Korean wheat cultivars, thickness of noodle dough sheet was positively correlated with protein content and mixograph water absorption regardless of both types of the machines. Cooked noodles from Korean machine showed higher hardness and lower springiness than noodles from Japanese noodle machine, but difference in cohesiveness of cooked noodles was not found between two different noodle machines. In the three Korean wheat cultivars with different protein content, thickness of noodle dough sheet was also positively correlated with protein content, SDS sedimentation volume and mixing time of mixograph in both types of the machines. The more protein content increased, the more hardness of cooked noodles increased regardless of both types of the machines. However, springiness and cohesiveness of cooked noodles were not significantly correlated with protein content. In waxy and partial waxy wheat cultivars, lightness of noodle dough sheet from Korean noodle machine positively correlated with amylose content. Amylose content and setback in pasting properties were positively correlated with hardness, springiness, and cohesiveness of cooked noodles while both damaged starch and breakdown were negatively correlated with those.
        29.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        Mixolab is suitable to evaluate mixograph and farinograph for testing dough rheology and amylopgraph for properties of starch pasting with a view to analyze protein and starch quality at the same time. Mixolab analysis revealed that water absorption and dough development time of Korean wheat cultivars were similar to it of soft wheats and flour while dough stability and protein weakening of Korean wheat cultivars were similar to it of hard wheat and strong flour. Also, starch properties of Korean wheat cultivars showed similar properties of hard wheats. There was a significantly positive correlation between mixolab and mixograph in the water absorption of dough, whereas no correlation was observed between them in dough development time and stability. Furthermore, maximum viscosity of starch and breakdown in amylopgraph were correlated to stabilities of pasting and cooking and setback in mixolab. Resultantly, in mixolab, properties of dough and protein highly and positively correlated to loaf volume, hardness of noodles, and size of cookies i.e. diameter. Moreover, positive correlation was identified between viscoelasticity of noodles and properties of protein, pasting, and setback in mixolab.
        30.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        This study was executed to establish a basis of evaluation of starch properties of Korean wheat cultivars e.g. damaged starch, swelling, and pasting properties for Korean wheat breeding program. Damaged starch is critical evaluation factor for flour milling related industry because it influences water absorption and color of dough for processing quality and preference of end-use products. The present results revealed that there was significantly high positive correlation between the results of damaged starch analysis by amperometric (SD-matic) and enzymatic (Megazyme assay) methods. Evaluation of damaged starch must be considered as one factor to evaluate properties of starch due to its accuracy and a stable efficiency for the wheat breeding program. Properties of swelling and pasting of dough were important for cooking time and texture. Nevertheless, it was impossible to evaluate starch extracted from flour in the wheat breeding program i.e. small amount of flour or small number of spikes Comparison of results of evaluation of properties of swelling and pasting with starch or flour, the evaluation using flour positively correlated with the other evaluation using starch. In addition, swelling evaluation must be considered to apply for the wheat breeding program because the result of evaluation of swelling property, which possible to evaluate with low efficiency, and the quantity of a sample is highly under positive correlation with paste peak viscosity. In the future, studies using NIR (Near Infrared) analysis must be necessary to evaluate starch properties with grains in early generation lines for improvement of wheat breeding program.
        31.
        2016.10 서비스 종료(열람 제한)
        3 tests are performed to analyze the specific performance and pullout strength of an anchor bolt which has a greater contact area with the concrete. In the case of connecting bar which connect the non-symmetric nuts together, the pullout strength greatly increased than the normal bolt cases.
        32.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        Genetic variations of γ-/ω-gliadin and Spa (storage protein activator) in 40 Korean wheat cultivars were evaluated to provide genetic information for improving end-use quality in wheat breeding programs. Korean wheat cultivars were classified into 13 patterns at the Gli-1 locus based on the allelic variation using A-PAGE (acidic-polyacrylamide gel electrophoresis). Seven, five, and six alleles were identified at Gli-A1, Gli-B1, and Gli-D1 loci, respectively. Allele-specific PCR markers for γ-gliadin corresponded to specific allele at Gli-1 loci on A-PAGE, which Gli-A1f, Gli-A1h and Gli-A1l alleles corresponded to GliA1.2, Gli-B1h and Gli-B1f alleles corresponded to GliB1.2 and Gli-D1f, Gli-D1m and Gli-D1o alleles corresponded to GliD1.1. DNA markers for γ-45 and γ-42 also corresponded to the γ-gliadin patterns around 40kDa on A-PAGE, except in Sukang, Ol and Joongmo2003. However, allelic specific PCR markers for ω5-gliadin did not correspond to that of A-PAGE. Three alleles were identified at Spa-A1 locus, whereas there was no variation at Spa-B1 and Spa-D1 loci.
        33.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        Developing rice lines with various amylose contents is necessary to diverse usages of rice in terms of raw materials for processed food production, and thereby to promote rice consumption in Korea. A rice mutant line, ‘Namil(SA)-dull1’ was established through sodium azide mutagenesis on ‘Namil’, a non-glutinous Korean Japonica rice cultivar. Namil(SA)-dull1’ had dull endosperm characteristics and the evaluated amylose content was 12.2%. A total of 94 F2 progenies from a cross between ‘Namil(SA)-dull1’ and ‘Milyang23’, a non-glutinous Tongil-type rice cultivar, was used for genetic studies on the endosperm amylose content. Association analyses, between marker genotypes of 53 SSR anchor markers and evaluated amylose contents of each 94 F2:3 seeds, initially localized rice chromosome 6 as the harboring place for the modified allele(s) directing low amylose content of ‘Namil(SA)-dull1’. By increasing SSR marker density on the putative chromosomal region followed by association analyses, the target region was narrowed down 0.94 Mbp segment, expanding from 28.95 Mbp to 29.89 Mbp, on rice chromosome 6 pseudomolecule. Among the SSR loci, RM7555 explained 84.2% of total variation of amylose contents in the F2 population. Further physical mapping on the target region directing low amylose content of ‘Namil(SA)-dull1’ would increase the breeding efficiency in developing promising rice cultivars with various endosperm characteristics.
        34.
        2015.10 서비스 종료(열람 제한)
        12 tests are performed to analyze the specific performance and pullout strength of an anchor bolt against which has a greater contact area with the concrete. In the case of unsymmetric nut, the pullout average strength at the side registers over 14% stronger in comparison with normal bolts.
        35.
        2015.09 KCI 등재 서비스 종료(열람 제한)
        The roots of Platycodon grandiflorum species either dried or fresh, are used as an ingredient in salads and traditional cuisine in Korea. To interpret the root proteins, a systematical and targeting analysis were carried out from diploid and tetraploid roots. Two dimensional gels stained with CBB, a total of 39 differential expressed proteins were identified from the diploid root under in vivo condition using image analysis by Progenesis Same Spot software. Out of total differential expressed spots, 39 differential expressed protein spots (≥ 1.5-fold) were analyzed using LTQ-FTICR mass spectrometry. Except two proteins, the rest of the identified proteins were confirmed as down-regulated such as Isocitrate dehydrogenase, Proteasome subunit alpha type-2-B. However, the most of the identified proteins from the explants were mainly associated with the oxidoreductase activity, nucleic acid binding, transferase activity and catalytic activity. The exclusive protein profile may provide insight clues for better understanding the characteristics of proteins and metabolic activity in various explants of the economically important medicinal plant Platycodon grandiflorum.
        36.
        2015.09 KCI 등재 서비스 종료(열람 제한)
        Buckwheat sprouts are a vegetable; a functional food should provide health benefit and enhance performance as high nutritionally important substances. Buckwheat noodles are the major buckwheat food in Japan, Korea and China. In addition, Buckwheat as preventive medicine has undergone a great advancement in the last decade. Comparison of the functional properties distribution and utilization in tatary buckwheat is required of understanding the metabolites. The study was conducted to identify the sorts of phenolic compounds and metabolites in tatary buckwheat seedling at 4, 7, and 10 days seedling under the different combinations of lightemitting diode (LED) such as blue, red, mix (red, blue, and white), dark, and natural lights in stem and leaves. After breaking the dormancy, buckwheat seeds were grown in culture room under lights for 14 hrs and the dark condition for 10 hrs, at 25ºC for 10 days. Length of buckwheat was gradually increased under all of the conditions. Using HPLC, rutin was highest at 7 days under mix and natural light in stem and leaf, respectively. Quercetin was highest at 4 and 7 days under natural light in both. Chlorogenic acid was highest at 7 days under mix and natural in stem and leaf, respectively. Taken Together, this study indicates that phenolic compounds and metabolites present in those plants could be helpful for the human health and nutritional additive.
        37.
        2015.07 서비스 종료(열람 제한)
        기상조건의 변화로 우리나라에 벼멸구의 발생이 점차 증가하며 피해가 커지고 있다. 이에 다양한 벼멸구 저항성 유전자를 가진 벼 품종의 육성이 필요하다. 국내 육성 자포니카 벼 품종 중 벼멸구 저항성 품종은 Bph18 유전자를 가진 ‘안미’를 제외하고 모두 bph2(‘화청’, ‘하남’, ‘다청’, ‘친농’, ‘친들’) 유전자를 가지고 있다. 유묘검정 결과 bph2 유전자를 가진 품종은 벼멸구 흡즙에 중도저항성을 보인 후 4주 이상 지나며 고사되는 반면, ‘안미(Bph18)’는 계속해서 강한 저항성 반응을 나타낸다. 인공교배를 통해 Bph18 유전자를 가진 계통을 육성하였다. 빠른 DNA 마커 검정을 위해 12번 염색체의 Bph18 유전자와 연관된 마커를 검색하여 PCR 후 전기영동을 수행한 결과 RM3331이 저항성 유전자별 밴드의 위치가 다른 증폭 반응을 보였다. 각 계통에 대한 밴드분석 결과 벼멸구 저항성 유전자가 없는 ‘TN1’과 ‘호평’은 위치가 다른 밴드를 보였는데 이는 인디카와 자포니카의 유전적 백그라운드의 차이로 프라이머의 증폭 부위가 달라 발생한 것으로 추측된다. Bph18 유전자를 가진 ‘익산562호’와 Bph1 유전자를 가진 ‘청청벼’, ‘Mudgo’, ‘IR09N379’의 밴드 위치가 같은 것은 두 유전자가 중복되어 위치해 있기 때문인 것으로 보인다. 따라서 RM3331로 생성된 PCR 산물의 크기는 제한효소 처리없이 2% agarose gel로 분석이 가능한 간편성을 가지고 있지만, 저항성 유전자가 중복되어 있는 Bph18과 Bph1 유전자를 구분하기는 어려우며 벼멸구 저항성 유전자를 가지고 있지 않은 계통과의 구분에 선택적으로 사용하는 것이 적합할 것으로 보인다.
        38.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        본 연구는 국내 조생종 벼 품종들과 농촌진흥청 국립식량과학원에서 육성된 자포니카(Oryza sativa L. ssp. Japonica)의 조생 다수성 품종인 남일 돌연변이 계통인 중모1024의 등숙기 고온내성을 비교 평가하여 등숙기 고온내성의 기초 자료를 얻고자 수행하였다. 본 연구를 통하여 국내 조생종 벼 품종들 중 대봉, 운광, 및 만안과 돌연변이 계통인 중모1024가 고온에서 상대적으로 양호한 고온내성을 가지고 있는 것으로 평가되었으며. 특히 중모1024는 다른 공시품종들에 비하여 상당히 양호한 고온내성을 가진 것으로 평가되었다. 본 연구의 주요 결과는 등숙기간 동안 고온에 의하여 현미의 길이와 너비가 감소하였으며, 현미 너비의 감소율이 현미 길이의 감소율에 비하여 평균 4배 이상 높았다. 이러한 결과로 보아, 등숙기간 동안 고온에 의하여 현미의 길이보다는 너비가 더 많은 영향을 받는다고 사료된다. 등숙기간 동안 고온에 의해 가장 문제가 되는 완전미율과 미숙립율을 공시품종들간 비교 평가한 결과, 상대적으로 중모1024, 태봉, 운광 및 만안이 고온에서 높은 현미완전미율을 보였으며, 상대적으로 적온에서 낮은 현미완전미율을 보인 품종들이 상대적으로 고온에 의한 현미완전미율 감소율이 적온에서 높은 현미완전미율을 보인 품종들에 비해 낮았다. 또한, 다른 공시품종들에 비하여 고온내성이 양호한 중모1024는 고온에서도 좋은 쌀 외관품위와 안정적 수확성 향상을 위한 육종모재로서 유용형질을 교배를 통해 고품질 벼의 보완을 위해 이전할 수 있는 것이 용이할 것으로 사료된다.
        39.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the effect of pre-germination soaking on germination in 90 Korean soybean varieties and identification of protein in seeds of 7 soybean varieties. The results obtained that germination rate of soybean seeds was decreased as amount of soaking water and soaking duration in number of days. Difference in germination rate of soybean seeds was significant at three days soaking with water volume of 90 ml. Water absorption of seeds was rapidly increased during the first 6 hours, followed by slow increase until 24 hours and then decreased 24 to 48 hours after soaking soybean varieties for bean sprout soaked the lowest amount of water, while soybean varieties for cooking with rice showed the lowest seed water content. Dissolved oxygen (DO) in soaking water was rapidly decreased during the first 3 hours after soaking, and then slowly decreased. Soybean varieties for vegetable and early maturity showed the lowest DO during early soaking periods, but showed higher DO after 24 hours than other groups of soybean varieties. Electrical conductivity and Total Dissolved Solid (TDS) were increased as number of soaking days increased. Soybean varieties for vegetable and early maturity showed the highest electrical conductivity and TDS, followed by those for sauce and paste or cooking with rice, while showed the lowest electrical conductivity and TDS, varieties for bean sprout. Among 90 Korean soybean varieties, varieties which showed the highest germination rate were Jangsu-kong for sauce and paste, Sobaegnamul-kong for bean sprout, Seonheuk-kong for cooking with rice, Seunnokkong for vegetable and early maturity. On the ather hand varieties which showed the lowest germination rate were Iksan and Songhak-kong for sauce and paste, Pangsa-kong for bean sprout, Jinyeul-kong for cooking with rice, Sinlok-kong for vegetable and early maturity. Germination rates of soybean seeds were higher when electrical conductivity, TDS and water absorption of seeds were lower. There were negative correlations between electrical conductivity, TDS and water absorption of seeds and germination rate, while there were positive correlations among electrical conductivity, TDS and soybean seed weight.
        40.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        Soybean is very useful crop to supply vegetable protein for human. However, cultivation arear of this economically important crop is gradually diminished in upland field. Hence, cultivation area of soybean is increased in paddy field. During the growth duration of soybean, excessive moisture injury is serious problem for sustainable production and supply. We investigated protein expression according to different period of seed soaking and germination after seed soaking. For comparison on expression of protein according to different condition, we performed two-dimensional electrophoresis. After electrophoresis analysis, we selected differentially expressed protein spots according to different condition such as soaking period and germination after soaking to identify protein function by using MALDI-TOF. Results revealed that pattern of expression of protein according to soaking period and germination after soaking were generally not different in major spots. However, degree of expression of protein in some protein spots was increased in accordance with decrease of soaking period. Especially, in Hwangkeum-Kong, Danyeop-Kon, and Pecking, the degree of expression of protein was remarkably increased for 4 days after soaking. But, according to germination after soaking, degree of expression of protein in germinated seeds of all cultivars was higher than un-germinated seeds. In results of MALDI-TOF analysis, specific proteins were identified by different soaking period such as Allergen Gly m Bd 28K, P24 oleosin isoform B. Also, in accordance with germination, degree of protein expression of the related protein, Gibberellin was increased in un-germinated seeds of Iksan-Kong. In ungerminated seeds of Sinpaldal-kong, proteins were identified as down-regulated by soaking such as ATP binding and Inhibitor II', proteinase.
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