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        검색결과 242

        141.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The esterification of free fatty acid in Jatropha oil added by propylene glycol using p-TSA catalyst was done, and then the transesterification of Jatropha oil added by 1.0vol% GMS as an emulsifier using TMAH, and mixed catalyst(60wt%-TMAH+ 40wt%-KOH) respectively was followed at 60℃. The esterification conversion at the 1:8 molar ratio of free fatty acid to methanol using 8.0wt% p-TSA was 94.7% within 60min. The overall conversion at the 1:8 molar ratio of Jatropha oil to methanol and 60℃ using mixed catalyst was 95.4%. The kinematic viscosity of Biodiesel using TMAH and mixed catalyst in 24h met the ASTM D-6751 above 30℃, and showed a little more than its criterion.
        4,000원
        142.
        2008.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to reduce the bycatch of young fishes and other species in the octopus(Octopus vulagris, Octopus dolfleini) trap fishery on the East Sea, Korea. We carried out field experiments and tank experiments to verify the fishing efficiency and bycatch with the different 8 types of trap. 4 of them had mesh size 20, 35, 55 respectively and 75mm, 2 of them with escape ring of diameter 30mm and 50mm and 2 of them with escape device. The gap was 20 and 40mm respectively. The mesh sizes of the traps with ring and frame were 20mm. The traps with mesh size 20 and 35mm were not reasonable because it could fish under 300g octopus as bycatch which is not permitted by the Korean fisheries regulations. The catch number of octopus over 300g by traps with escape ring of diameter 30mm was 53. The catch of trap with mesh size 20mm was 54. The catch of trap with mesh size 35mm was 53. There is no significant difference among them. The catch number of octopus over 500g that is fishermen's favorite one was 46 in the trap with escap ring. The diameter of was 30 mm and the catch of trap with mesh size 20mm was more 3 catch and the catch of trap with mesh size 35mm had 6 more catch. Fishermen wanted to catch over 500g octopus because the octopuses had commercial value. The traps with escape ring can be replaceable with he traps with mesh size 20 or 35mm because the trap is suitable to conserve the octopus resources and keep the fishermen's fishing substantiality.
        4,000원
        143.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The transesterifications of beef tallow and the mixture of beef tallow and rapeseed oil were conducted at 65℃ respectively using TMAH, NaOH and their mixed catalysts. The reactants were emulsified with 1vol% emulsifier and propylene glycol. The overall conversion of beef tallow was 95% at such optimum conditions as the 1:8 of molar ratio and 0.8 wt% TMAH. The overall conversion of mixed fat at the 1:8 of molar ratio and mixed catalyst of 70 wt% TMAH 30 wt% NaOH was close to 97% which appeared at 0.8 wt% TMAH in 80min. And the kinematic viscosity of biodiesel mixture using the mixed catalyst was 6.5mm2/s at 40℃.
        4,000원
        144.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국중부 지역에 서식하는 수리부엉이(Bubo bubo)의 먹이를 확인하고 서식 환경에 따른 먹이습성을 파악하기 위하여 사냥흔적 및 먹이 잔존물 82개, 소화되지 않은 먹이 덩어리인 펠릿(pellet) 55개를 각각 분석하였다. 그 결과 조류, 포유류 및 곤충으로 구성된 총 150개체의 먹이가 확인되었으며, 그 중 조류의 이용 빈도(56.67%) 및 생물량(78.04%)이 가장 높았다. 집쥐류(Rattus spp.), 꿩(Phasianus colchicus), 등줄쥐(Apodemus agrarius)를 흔히 이용하였으나, 생물량 측면에서 꿩이 가장 중요한 먹이로 나타났다. 척추동물을 기준으로 한 수리부엉이 먹이의 평균 생물량은 503.3g으로서 비교적 다양한 크기의 먹이를 포식하였으나, 개활지 보다 산림지역에서 더 크고 다양한 먹이를 이용하였다. 산림지역에서는 꿩과 원앙(Aix galericulata) 등의 조류를 많이 포식하였으나, 특정 분류군을 선호하기 보다 적정 크기의 먹이를 선호하는 양상을 보였다. 반면 개활지에서는 소형의 특정 포유류(설치류)에 의존하면서 큰 생물량을 가진 꿩 등의 조류를 일부 이용하는 기회주의적인 먹이습성을 보였다.
        4,000원
        146.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The esterification of palmitic acid in rapeseed oil and methanol emulsified by propylene glycol with PTSA(p-toluene sulfonic acid) was followed by the transesterification of rapeseed oil into biodiesel with 1(w/v)% GMS(glycerol monostearate) as an emulsifier using TMAH(tetramethyl ammonium hydroxide) catalysts at 60℃. The former reaction was optimized at the 1:20 of molar ratio of oil to methanol and 5wt% PTSA, and the latter was optimized at the 1:8 of molar ratio of oil to methanol and 0.8wt% TMAH. The overall conversion into biodiesel was 98% after 60min of reaction time at the 1:8 of molar ratio, 0.8wt% TMAH and 60℃. TMAH was a good catalyst to control the viscosity of biodiesel mixture.
        4,000원
        149.
        2006.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was planned to investigate the current using status of agricultural products in school food service both produced in Korea and imported from other countries and the dieticians' perception on using those. A total of 723 dieticians of 442 elementary schools and 381 middle high schools were surveyed in July, 2003 to perform the purposes of the study. A high using rate (93.4%) for Korean agricultural products was investigated. As for meat such as pork and chicken except beef and eggs, the using rate of Korean agricultural products was high. Almost 100% of vegetables and fruits, except tropical fruits such as banana, kiwi, orange and pineapple supplied for school food service were also Korean products. As for nuts and edible oil, the rate of using for Korean agricultural products was comparatively lower than those of other food items due to the price gap. Most dieticians rated the quality of the products produced in Korea higher than that of the imported products in the aspects of their freshness, taste, and safety. But they found no difference in the package condition of the products produced in Korea and of those imported from other countries. This result suggests that the package system should be improved for the agricultural products produced in Korea.
        4,300원
        150.
        2006.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The transesterification of vegetable oils into Biodiesel at 60℃ was performed on the rotary viscometer. The overall yield(%) of fatty acid methyl ester from canola oil at optimum conditions was 95%. The viscosities of fatty acid methyl esters were predicted by Orrick and Erbarr's model. The overall yield increased as the viscosities of fatty acid methyl esters decreased. The limiting molar ratio of methanol to oil appeared to be 1:5. The content of sodium hydroxide as the optimum catalyst appeared to be 0.5wt%.
        4,000원
        151.
        2006.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The behavior patterns of common octopus, Octopus minor to a cylindric trap were examined in the water tank using a video camera in order to know entering mechanism to the trap and to improve it. Fishing efficiency by 2 kinds of traps(A: 3 entrances, B: 2 entrances) was investigated in the coastal area of Deugryang Bay from May to July, 2005. Common octopus tends to approach by swimming more than walking towards trap. When they approached to the trap, they showed much more behaviors that sate at the around than upper part of it. Approaching behaviors of common octopus was more vigorous at nighttime than daytime on the trap, they showed the most vigorous action between 2 am and 4 am of the day. The rate of staying 30 seconds over around the trap was 41.5% in the nighttime. CPUE(g/trap) of common octopus caught by A type trap was 21.4% higher than the B type trap but there was no difference on the significance level of 5% by the ANOVA. Catch rate of common octopus and by-catch species caught by the A type trap were 97.2%, three and 98.7%, two for B type trap, respectively.
        4,000원
        154.
        2005.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The mesh selectivity of drum net traps for Buccinum opisoplectum Dall caught in the eastern sea of Korea was described. Several experiments were conducted between July 2003 and March 2004 and the data obtained from the experiment was fitted by SELECT (Share Each Length class's Catch Total) model with unequal fishing and sampling efforts. The selection curve was determined to be 'estimated fishing efficiency' by model deviance rather than AIC. However the fishing efficiency between 20mm and 35mm mesh size did not seem to be different. The L50 lengths of the selectivity for the 55mm and 75mm mesh size were 65.4mm and 96.0mm, respectively.
        4,000원
        155.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bio-diesel as fatty acid methyl ester was derived from such oils as soybean, peanut and canola oil by lipase catalyzed continuous trans-esterification. So the activation of lipase(Novozym - 435) was kept to be up to 4:1, the limiting molar ratio of methanol to oil under one-step addition of methanol due to the miscibility of oil and methanol through the static mixer for 4hrs and the elimination of glycerol on the surface of lipase by 7wt% silica gel. Therefore the overall yield of fatty acid methyl ester from soybean oil appeared to be 98% at 50·C of reaction temperature under two-steps addition of methanol with 2×2:1 of methanol to oil molar ratio at an interval of 5.5hrs, 7wt% of lipase, 24 number of mixer elements, 0.2ml/min of flow rate and 7wt% of silica gel.
        4,000원
        156.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        157.
        2004.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        동해안의 연안성 어족인 빨간횟대에 대해 망목크기 등을 달리한 8종류의 장구형 통발을 사용하여, 2003년 6월부터 12월까지 총 6차례에 걸쳐 어선 2척을 용선하여 조업한 어획실험으로부터 망목선택성 곡선을 구하여 합리적인 자원관리에 대한 기초 자료를 구하고자 하였다. 망목 크기가 20mm와 35mm인 두 통발의 빨간횟대 어획물로부터 체장에 따른 어획비율의 차이에 대해 특별한 경향을 발견할 수 없었다. 망목 크기가 20mm와 55mm인 두 통발의 경우에 대해 SELECT방법을 이용하여 equal split model 과 estimated split model을 적용한 결과, AIC 값이 적은 전자가 더 적절한 모델이므로, 빨간횟대의 경우는 이들 두 통발에 대한 입망률의 차이는 없는 것으로 나타났다. 망목 55mm의 통발에서 SELECT 모델로 구한 50% 어획될 빨간횟대의 전장은 22.0cm였다. 망목 크기가 20mm, 35mm, 55mm인 통발의 어획 자료에 Kitahara의 방법으로 logistic식을 적용하여 추정된 선택성 곡선식은 와 같았고, 현재 규정 망목 크기인 35mm 장구형 통발에 대해 50% 어획될 빨간횟대의 전장은 21.4cm이었다.
        4,000원
        158.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        159.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구의 목적은 첫째, 항만국 통제의 의의 및 시행배경과 이론을 고찰하고, 둘째, 항만국 통제와 관련된 국제협약관계를 고찰하며, 셋째, 항만국 통제에 대한 국제비교와 우리나라 해운기업의 사례를 분석하며, 마지막으로 이러한 분석결과를 토대로 항만국 통제에 대한 우리나라 해운기업의 대응방안을 제시하는데 있다.
        4,800원
        160.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 연직하중을 받는 평면 케이블의 처짐 형상을 결정하는 기법을 제안하였다. 케이블의 일반정리에 의하여 케이블의 처짐 형상을 구하는 경우 임의의 한 점에서 처짐이 기지값으로 주어져야 하지만, 본 연구에서는 이러한 처짐값이 주어지지 않는 일반적인 경우에 대하여 케이블의 정리와 기하학적 적합조건식을 토대로 케이블의 처짐 형상을 반복계산에 의해 결정하는 기법을 제시하였다. 또한, 본 기법은 케이블의 신장을 고려하는 경우에도 적용이 가능하도록 확장하였다. 본 연구의 기법으로 케이블의 신장이 발생하지 않는 경우에 대한 해석과 신장이 발생하는 경우에 대한 실내 모형실험 및 해석을 수행한 결과 제안한 기법이 타당한 것으로 판명되었다.
        4,200원