• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.53-55
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• 2014

Offshore 에서의 oil & gas 생산은 해상이라는 환경으로 인한 고유의 특성 때문에 항상 다수의 변수들에 영향을 받으며, 막대한 비용이 소요되기 때문에 비용을 최소화하며, 비용 대비 수익을 최대화시키기 위한 optimal design이 필수이다. 본 논문은 가상의 offshore plant와 이에서 생산된 oil의 수요지들을 설정하여 시장수요에 따른 offshore 생산의 최적화 문제를 연구대상으로 하며, 다수의 offshore oil fields를 보유한 major oil company가 당면할 수 있는 offshore production에 관한 문제를 일반화하여 정의하고, 이윤을 극대화시킬 수 있는 최적화 모형을 혼합정수계획모형(mixed integer programming)으로 정식화 하였다. 최적화 모형의 해는 Microsoft office excel solver를 통해 구하였으며 그 계산실험의 결과를 요약하여 보고한다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.11
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• pp.897-903
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• 2002

The periodic high vibration has been occurred one or two times a day for a 500 MW large steam turbine during 5 months. This abnormal vibration was caused by the rubbing between the rotor and the carbide accumulated on the seal tooth of oil deflector. It was found that the accumulated carbide was insulation material installed on the HIP casing from the examination of the chemical composition. Also, this paper presents the mechanism of the periodic high vibration and the proper method to eliminate this vibration problem. This result would be good practice to find the solution of similar high vibration in the steam turbines for power plant as well as industrial rotating machineries.

• Natural Product Sciences
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• v.25 no.2
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• pp.81-91
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• 2019

Marrubium vulgare, plant species belonging to Marrubium genus, is widespread in the Mediterranean areas, introduced elsewhere and also cultivated in many countries. Its oil is recognized to possess a considerable biological activities with varied chemical composition. This paper aims to overview the chemical composition and biological activities of M. vulgare essential oil's considered as a medicinal plant, widely used in folk medicine overall the world. In essential oils of M. vulgare, germacrene D, ${\beta}$-caryophyllene, ${\beta}$-bisabolene, bicyclogermacrene and carvacrol are generally considered as either mains or minor constituents and each species presents its own composition. Sesquiterpenoids were the dominant fraction while monoterpenoids were present in appreciable or in trace amount. Oxygenated fractions dominated in monoterpenes however, hydrocarbon fraction overpowered in sesquiterpenes. These oils are biologically active, they exhibit an antioxidant and antimicrobial activities and other activities. Due to the variability of composition of essential oil, further studies are necessary, particularly regarding their chemical's which may cause an important change in the biological activities of oils and probably defined different chemotype.

• Food Science and Preservation
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• v.31 no.3
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• pp.333-345
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• 2024

This study aims to provide an overview of the research on the chemical composition, nutritional value, biological activities, and potential applications of Camellia oleifera seeds. Camellia oleifera Abel. (Theaceae) is a type of woody plant found in various regions, including China, Japan, India, and Southeast Asia. This plant is highly valued for its cooking oil, as the oil extracted from its seeds contains many unsaturated fatty acids (90%), mainly oleic acid (80%), and various biologically active compounds. Oil derived from C. oleifera seeds has been shown to possess numerous health benefits, such as reducing low-density lipoproteins cholesterol levels, preventing cardiovascular diseases and cancer, and regulating blood pressure. Apart from its oil, the seeds of C. oleifera also contain remarkable biological compounds that offer additional health advantages. Despite these promising attributes, C. oleifera has yet to be widely recognized as a potential source of raw materials for pharmaceutical purposes. This lack of popularity and awareness has hindered further exploration of its pharmaceutical benefits and other uses. Through this article, we hope everyone can better understand this plant and have more practical applications in the future.

• Natural Product Sciences
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• v.7 no.4
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• pp.120-123
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• 2001

To develop systems for economic production of useful essential oil compounds, callus was induced from the seedlings of Agastache rugosa and cultured on MS medium. The volatile oil fraction was extracted from the callus and investigated by mean of GC-MS. The composition of the oil was compared with that of the mother plant. As a result, sixty five compounds including ferruginol were identified in the essential oil fraction. The main component of the oil from the leaves of Agastache rugosa was methyl chavichol (53.6%). Methyl jasmonate and jasmonic acid were added to the culturing cell suspension, separately and the composition of induced oil were compared. The oils from cultured cells treated with jasmonates showed considerably different patterns. Especially, the peak of estragole was found in callus oil after treatment with methyl jasmonate as though the amount was limited to 0.58%. In general, the TIC pattern of GC-MS of the callus oil became more similar to the oil from the leaves after elicitation.

• Journal of the Korean Society of Tobacco Science
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• v.25 no.1
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• pp.7-11
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• 2003

Repellencies of herb plants and essential oils against alate Myzus persicae were investigated in a insect cage, a screen house, and a tobacco field. Numbers of nymphs deposited by alate or apterous Myzur persicae were lower on rosemary(Rosmarinus officinalis), silver thyme (Thymus vulgaris), and lemon balm(Melissa of fcianazis). Rosemary and silver thyme show little repellency against alate Myzus persicae on a nearby tobacco plant Rosemary oil, peppermint (Mentha piperita) oil, and ginger oil showed repellency against alate Myzus persicae, but spearmint (Mentha spicata) oil and lavender oil showed little repellency in a screen house. Rosemary oil, ginger oil, peppermint oil, lavender oil, and spearmint oil showed repellency against alate Myzus persicae in a tobacco field, but there was no significant difference among oils.

• Natural Product Sciences
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• v.23 no.4
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• pp.235-238
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• 2017

Colorado potato beetle is a most destructive insect pest of potato throughout the world. Although utilization of chemical insecticides is a main method for management of this pest, their negative side-effects such as threat to humans and the environmental pollution prompted researchers to search for natural alternatives. Recently plant essential oils with low or without side-effects against noun-targeted organisms and with high availability were considered as safe bio-pesticides. In the present study, toxicity of essential oil of Iranian lemongrass, Cymbopogon citratus Stapf, was evaluated against 3th instar larvae and adults of Colorado potato beetle by a leaf dipping method. Results displayed essential oil had notable toxicity against both larvae and adults after 24 and 48 h exposure times. Probit analysis revealed $LC_{50}$ values (lethal concentration to kill 50% of population) with 95% confidence limits were 10.32 (9.17 - 11.72) and 7.76 (6.80 - 8.74) ${\mu}l/ml$ for larvae and 6.27 (4.82 - 8.15) and 4.35 (3.24 - 5.62) ${\mu}l/ml$ for adults after 24 and 48 h, respectively. Based on regression analysis, a positive correlation between log concentration of essential oil and insect mortality was achieved. Results indicated C. citratus essential oil can be candidate as a natural alternative to the harmful chemical insecticides in the management of Colorado potato beetle.

• Research in Plant Disease
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• v.18 no.1
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• pp.1-9
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• 2012

A total of 20 agricultural organic materials including inorganic compounds, plant oils and plant extracts were used in the study for assessing the control efficacy on pepper diseases. Among inorganic compounds, only copper hydroxide showed inhibitory effect on both Phytophthora capsici causing Phytophthora blight and Colletotrichum acutatum causing anthracnose. Phosphorous acid inhibited the growth of P. capsici on PDA, and Sulfur/quicklime had it on that of C. acutatum. Plant essential oil, rosemary oil, and rapeseed oil among plant oils and plant extract of Japanese apricot/ginkgo nut inhibited the mycelial growth of the two pathogens. In the screening using pepper plant seedlings, the control efficacy on Phytophthora blight in 6-leaf stage of seedling was superior to that in 4-leaf stage of seedling. A protective effect on Phytophthora blight was displayed by copper hydroxide, sulfur/quicklime, water soluble calcium, phosphorous acid, plant essential oil, and cloves extract. When C. acutatum was inoculated by the non-wound method, copper hydroxide and rapeseed oil showed excellent protective activities with control values of 91.3% and 82.6%, respectively. However, copper hydroxide did not show any activity, when C. acutatum was inoculated after wounding pepper fruits. All organic materials never showed the curative effect on Phytophthora blight and anthracnose in pepper seedling assay and fruit assay.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.865-875
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• 2018

Selection of optimum reaction conditions during deoxygenation process of palm oil is essential factor to obtain the maximum yield of bio-jet fuel. In this context, the deoxygenation of palm oil was carried out in a fixed bed reactor with an internal diameter of 1 inch loaded with a 1 wt.% $Pt/Al_2O_3$ catalyst. The composition of the organic liquid product(OLP), which can be utilized as a transportation fuel through the upgrading process, was analyzed by a gas chromatography method. The palm oil/hydrogen ratio and hydrogen pressure in the feed affected the decarboxylation(DCB) and hydrodeoxygenation(HDO) reactions, resulting in a change in the composition of the OLP. As the reaction temperature increased, the continuous cracking reaction of the deoxygenation product was promoted and the product composition in the $C_5{\sim}C_{14}$ region was increased. Thus, the results can help to understand the characteristics of deoxidation reaction of palm oil as well as the subsequent process, hydro-upgrading, to obtain the maximum yield of bio-jet fuel.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.491-494
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• 2007

Recently Gas & Oil plant construction projects are increasing in the world. The EPC (Engineering, Procurement and Construction) company, which participate in the plant projects, should possess the pertinent engineering license and procurement skill to create high added-value. It is because the procurement is very substantial to cover 70% of the total project cost. Nonetheless, there exist various risks involved in the procurement process due to the characteristics of the construction projects with long duration and complicated process as well as the procured goods or services subjected to various logistics. The objective of this paper is to analyze proper process in the procurement and to identify various information and document. Also to analyze procurement process, the principal data are derived from the interview with experts and specialty contractors of plant project. The result of this study would widely be used as a guide to the procurement personnel in forecasting the risks in advance.