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        검색결과 171

        141.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        Since biodiesel as bioenergy is defined as ester compounds formed by esterification of animal/vegetable oils, in this study three vegetable cooking oils (market, waste and refined waste ones) were esterified by reactions of alkali catalyst and immobilized enzyme. The fatty acid composition of the formed ester compounds was analyzed to investigate the feasibility of biodiesel production. By lipolysis (i.e, hydrolysis of Triglyceride (TG)), all three vegetable oils used in this study were found to produce Diglyceride (DG), Monoglyceride (MD) and Fatty acid ethylester (FAEE). However, the amount of produced FAEE (which can be used as an energy source) was in the increasing order of market cooking oil, waste one and refined waste one. With NaOH catalyst, FAEE was produced about 24.92, 17.63 and 11.31 % for the respective oils while adding Lipozyme TL produced FAEE about 43.54, 38.16 and 24.47 %, respectively. This indicates that enzyme catalyst is more effective than alkali one for transesterification. In addition, it was found that the composition of fatty acids produced by hydrolysis of TG was unchanged with alkali and immobilized enzyme reactions. Thus it can be expected that stable conditions remain in the course of mixing with gasoline whose composition is similar to that of the fatty acids.
        142.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        Recent studies have shown that alum addition to litter results in many environmental and economic advantages, such as reductions in metal runoff, lower ammonia emission and improved poultry performance. However, no research has been conducted to evaluate the effects of different types of alum on soluble metals in poultry litter. The objective of this study was conducted to investigate changes in soluble metal from poultry litter with different types of aluminum sulfate (alum) under laboratory condition. The treatments used in this study, which were mixed in the upper 1 cm of litter or sprayed onto the litter surface, were 4 g alum, 8 g alum, 8.66 g liquid alum, 17.3 g liquid alum, 11.2 g A7 (high acid alum), and 22.4 g A7 (high acid alum)/100 g litter. Applying different types of alum to poultry litter reduced (P<0.05) concentrations of soluble Fe (9 to 54%), Cu (9 to 49%) and Zn (11 to 40%), relative to untreated litter, whereas it increased Ca and Mg (P<0.05). Mean soluble Fe and Cu levels in poultry litter from different types of alum decreased in the order: 22.4 g A7 (54% and 49%) > 17.3 g liquid alum (48% and 42%) > 8 g alum (48% and 31%) > 4 g alum (28% and 10%) > 8.6 g liquid alum (10% and 9%) > 11.2 g A7 (8.6% and 9%). Additionally, the high reduction in soluble Zn concentration was 4 g alum (40%), followed by 8 g alum (26%), 22.4 g A7 (25%), 17.3 g liquid alum (23%), 8.66 g liquid alum (18%), and 11.2 g A7 (11%), respectively. In conclusion, the current studies suggest that treating poultry litter with different types of alum can be applied to reduce soluble metal (Fe, Cu, and Zn) and to develop a production to merchandise for poultry litter that would result in reduction in pollutants from these materials. Furthermore, in order to improve environmental management in the poultry industry, the use of alum, liquid alum and high acid alum all should be provided a valid means of reducing negative environmental impact.
        144.
        2008.08 KCI 등재 서비스 종료(열람 제한)
        Drawing on Herzberg's two-factor theory, this article suggests that visitors to rural tourism base their overall evaluation with an experience on their consideration of two types of aspects referred to as either 'motivators' and 'hygienes' by using the critical incident technique. 233 critical incidents described by 121 participants are categorized into three exclusive factors which are named as experiential factor, cognitive factor, and affective factor. The application of Herzberg's two-factor theory to rural tourism suggests 'satisfiers' to come from the experience-activity itself, experiential factor. While more peripheral elements constitute 'dissatisfiers', cognitive factor. The paper provides the advancement and broad application of Herzberg's theory to further understand rural tourists satisfaction.
        145.
        2008.06 KCI 등재 서비스 종료(열람 제한)
        Recently, rural leisure by urban dwellers has been recognized as a catalyst for regional development or restoration. The federal government implemented several regional planning policies attempting to address this phenomenon in the late nineties. However, most of these policies focused on supply-centered planning, which caused a diverse set of problems relating to the sustainability and economic validity of the planning. Instead, this study focuses on the re-visitation one of the demand variables, with the intention of analyzing the character of rural leisure demand and its re-visitation choice attributes. For these reasons, this study investigates the character of current rural leisure demand, and develops functional equations about urban people who visit rural areas, using logit model. The results of this study can be summarized as follow: Urban people are visiting rural areas from nearby cities or metropolitan areas that are within 3 hours driving distance, and over 80% of rural visitors are one-day visitors. Therefore, most of their visitation activities should be understood as rural leisure, including rural tourism. In addition, the likelihood of the rural tourist to make a return visit is influenced by their transportation means, product purchasing, staying period and travel time. The results of such rural leisure demand can provide information for regional planning strategies, such as selection of target market, type of market segments, improvement of recognition level, activity program price, facility and space planning, produce sale and connection with tour site.
        148.
        2007.02 KCI 등재 서비스 종료(열람 제한)
        한국의 전통적인 민간 약재로 사용되어져온 흰민들레의 잎절편체로 부터 기관형성을 통한 재분화를 시도하였다. 잎 절편체를 BA (0-4mg/L)와 2,4-D (0-1mg/L)가 혼합 첨가된 MS 기본 배지에 치상하여 배양한 결과, 배양 3주후부터 신초가 발생되었다. 신초 분화율은 2mg/L BA 첨가된 조건에서 가장 높았으며, 배양 4주째 4mg/L BA 첨가된 조건에서는 캘러스가 유기되었다. 잎령에 따른 부정아 형성율, 발생빈도, 건량, 생중량을 조사한 결과, 발아 후 7주된 잎 절편체에서 평균 11.5개의 신초를 형성하였다. 유도된 신초는 0.5mg/L NAA가 첨가된 배지에서 발근되었으며, 화분에 옮겨 완전한 식물체로 재분화 되었다.
        149.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        오늘날에 항만부진동의 문제는 대형선박이 입출항하는 항만의 설계에서 가장 현저한 인자로 작용한다. 연안 항만에서 탄성체의 삭으로 계류하고 있는 대형 선박은 장주기파랑과 계류시스템간의 공진으로 인해 종종 이탈되기도 한다. 특히, 장주기 파랑의 증폭비가 현저해지면 화물의 하역에 장애를 가져오며 계류삭이 절단되는 경우도 발생한다 이중 국내에서 부진동의 문제가 가장 현저하게 나타난 항만은 포항신항이며, 이에 따른 문제가 도선사 협회나 지역해양수산청으로부터 보고되고 있다. 그러나 이 항만에서 부진동을 야기하는 장주기 파랑의 내습을 막는 것은 어렵다. 더구나 정부는 이미 포항신항에서 발생하고 있는 이러한 문제점을 해결하지 않고 영일만의 입구에서 신항만 건설을 이미착수해놓고 있다. 본 연구는 영일만 입구의 4.1km에 달하는 방파제 건설과 신항만 계획을 반영하여 이들이 항만 부진동에 어떠한 변화를 가져오는 것인가에 대해 다룬다. 사용한 수치기법은 확장완경사방정식을 사용한 표준형식을 갖춘 것으로 수치실험결과를 이전 연구를 통해 이루어진 관측치와 비교하였으며, 이것이 어느 수준까지의 토론으로 이끌어 낼 것이며 장래 항만개발에 변화를 가져올 것으로 본다.
        150.
        2004.01 KCI 등재 서비스 종료(열람 제한)
        An author has been known that A-type zeolite supported with silver ions has excellent antibacterial activity. However, it is no research of concern in the antibacterial activity of eluted silver ions. This study tested the elution of silver ions from A-type zeolite silver ions in deionized distilled water and NaNO3 aqueous solution. In NaNO3 aqueous solution of 74mM to 588mM, it was found that the concentration of silver ions and electric conductivity increased with the increasing concentration of sodium ions, and equilibrated at 15 min, and the ion exchange equilibrium coefficient, k, is 1.3×10-3. However, deionized distilled water is not equilibrated to pass 6 months. A-type zeolite sodium ions showed no antibacterial activity. It was found that antibacterial activity was exhibited even at the concentration of 10 nM of eluted silver ions, and E-coli died with the incorporation of 2.43×108 Ag ion/cell. antibacterial activity of A-type zeolite silver ions were mainly attributed to hydroxyl radical.
        152.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        It is claimed in the literature (e.g., Suh 1990, Sohn 1995, etc.) that an NPI freezes the scope relation between a quantifier (QP) and negation: a QP to the left of an NPI scopes over negation and a QP to the right of an NPI scopes under negation. (A QP scopes over or under negation when no NPI is around.) The scope freezing effect induced by NPIs has been accounted for by (often tacitly made) assumptions that (i) NPIs are in the scope of negation; (ii) the negation scope is NegP; and (iii) NPIs are licensed at the SPEC of NegP. This paper first provides sets of data showing that the so-called scope freezing effect is not a well established generalization. Once the scope freezing effect turns out to be an illusion, theories based on the generalization should be reconsidered. Thus, this paper discusses some related issues and leads to the following conclusions: (i) NegP does not necessarily indicate the negation scope: (ii) NPIs may be located outside of negation scope at least in some environments, where they have a Free Choice reading; and (iii) contra Sells (2001), the NPI distribution in Korean cannot be captured in terms of the `command` relation but in terms of the `government` relation based on Chung`s (1995) typology of negation licensing.
        154.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        대황(Rheum undulatum L.)의 형질전환된 뿌리의 기내(in vitro)배양으로부터 quinone계 알칼로이드 물질인 anthraquinone의 생산성을 확인하고자 하였다. 형질전환된 뿌리로부터 anthraquinone의 생산에 있어서 배지, 초기 pH, 탄소원의 농도, 광 그리고 elicitors의 영향을 조사 하였다. 형질전환된 뿌리는 6% sucrose와 0.5 mg/l GA3 그리고 50 mg/l chitosan이 첨가된 WPM 배지에 치상한 후 16/8의 광조건(16μmol m2s1)하에서 배양시 0.18 mg(생중량)의 anthraquinone의 생산성을 보여주었다. 이와같은 함량은 재배근의 약 1.3배에 해당된다.
        155.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        수입 한약재의 기원식물에 대한 논란으로 야기된 사회문제 해결의 기초 자료로 제공하고자 본초강목에 수록된 약재의 기원식물을 찾아 Engler 체계로 정리하였다. 본 연구의 자료는 본초강목에서 식물성 약재를 다루고 있는 초부, 곡부, 채부, 과부, 목부 중에서 곡부에 수록된 약재 210 품목을 대상으로 하였으며 편의상 각 품목마다 임의의 번호를 부여하였다. 210 품목 중 기원식물을 정립한 것은 193 품목으로 이를 Engler 분류체계로 정리한 결과, 4문 5강 3아강 28목 17아목 46과 95속 100종 11변종 1품종으로 총 112종류의 식물로 정리되었다. 112종류의 식물을 문별로 비교해 보면 Angiospermae가 107종류로 95.53%, Gymnospermae가 3종류로 2.70%, Phaeophyta와 Fungi가 각각 1종류로 0.90%를 차지하는 것으로 나타났다. 210 품목중 사별반(祀鼈飯)을 포함한 17 품목은 그 기원을 정립할 수 없었다.
        157.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        소 배반포로부터 배아주 (embryonic stem, ES) 유사세포를 분리하기 위해서는 영양외배엽 (trophectoderm, TE) 세포를 제거하는 것이 효과적이다. 따라서 본 실험은 효과적으로 TE를 제거하기 위한 calcium ionophore A23187 (CIPA) 처리조건을 확립하고, 분리해낸 ES 유사세포의 in vitro 다능성 (pluripotency)을 검증하고자 수행하였다. CIPA 농도 및 처리시간을 달리 하였을 때 50 M에서
        158.
        1999.04 KCI 등재 서비스 종료(열람 제한)
        To verify the accuracy of the numerical experiment of Part I, measurements at the matured rice canopy located around Junam reservoir were performed at August 14, 1995. According to the measured data, the foliage temperature recorded the highest value, and the ground temperature was the lowest around noon, and these results coincided with those of the numerical experiment using the combined model of Part I. From the estimation using measured data, the maximum value of the latent heat flux was 380 Wm2, the highest value among energy balance terms, and the energy redistribution ratio of the latent heat flux was averaged as 0.5, the highest values among redistribution ratios. These results are the same as those of the numerical experiment in tendency, but they reveals a little lower in the absolute values than those from the numerical experiment.
        159.
        1999.04 KCI 등재 서비스 종료(열람 제한)
        To estimate the thermal effect of the vegetation canopy on the surface sublayer environment numerically, we used the combined model of Pielke's1) single layer model for vegetation and Deardorff's2) Force restore method(FRM) for soil layer. Application of present combined model to three surface conditions, ie., unsaturated bare soil, saturated bare soil and saturated vegetation canopy, showed followings; The diurnal temperature range of saturated vegetation canopy is only 20K, while saturated bare soil and unsaturated bare soil surface are 30K, 35K, respectively. The maximum temperature of vegetation canopy occurs at noon, about 2 hours earlier than that of the non-vegetation cases. The peak latent heat fluxes of vegetation canopy is simulated as a 600Wm2 a at 1300 LST. They have higher values during afternoon than beforenoon. Furthermore, the energy redistribution ratios to latent heat fluxes also increased in the late afternoon. Therefore, oasis effect driving from the vegetation canopy is reinforced during late afternoon compared with the non-vegetated conditions.
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