• 열병합발전
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• s.37
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• pp.18-21
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• 2004

There are several bearing system at large steam-turbines in thermal power plant. The bearing system is one of the most important parts of rotating machinery. The steam turbine vibrations mainly depend on the bearing oil the shaft alignment condition. This paper describes on the steam turbine abnormal vibration due to the oil whip in terms of the shaft alignment in the thermal power plant.

• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.115-120
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• 1999

This study was carried out to compare the essential oil and its composition, and estragol content at different growth stages in the local collections of A. rugosa. Estragol was the major constituent in essential oil of all collections tested. Estragol content in essential oil was $82.3{\sim}89.1%$ in leaves, $81.1{\sim}89.2%$ in inflorescence, $72.0{\sim}45.2%$ in stem and there was no significant difference among nine local colletions. At full bloom stage, essential oil content was significantly higher than other growth stages and the highest content of estragol in essential oil was appeared at this stage. Especially, the content of essential oil in the inflorescence of Mokpo collection was 3.3%, which was the highest among the collections. Mokpo and Jindo collections produced much more essential oil and estragol than the other collections both at full bloom and ripening stages.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.433-439
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• 2010

This study was performed to investigate repellent effect of plant essential oils against Bemisia tabaci adult. Among the 20 tested oils, wild mint oil repelled B. tabaci adult significantly (>90%) at a dose of $5{\mu}{\ell}$, but the other oils did not. In dose responses (2, 1, 0.5, $0.1{\mu}{\ell}$) to B. tabaci adult, wild mint oil showed repellent response (77.8~65.7%) significantly with dose-dependent manner. Wild mint oil analyzed by GC/MS revealed that the major components of wild mint oil were menthol (56.5%), menthone (29.0%) and menthyl acetate (14.5%), and the active components responsible for the effective repellency proved to be menthol (77.8%) and menthone (75.8%) when treated the proportion found in original oil. However, menthyl acetate did not show significant repellency. Combined constituents of wild mint oil were showed synergistic effect.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_2
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• pp.1081-1091
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• 2020

The most recent issue of offshore plants that produce oil and gas are the decommissioning engineering of aged or discontinued platforms. There are many platforms that are being dismantled in the United States, Europe, and areas in Southeast Asia. In particular, more than 400 old platforms in Southeast Asia (Indonesia, Malaysia) are preparing to dismantle. They are spread out across Southeast Asia with a water level of 50 meters and small-scale of less than 10,000 tons. However, this offshore plant decommissioning market is a very suitable market for small and medium-sized shipyards in Korea to enter with their established equipment and engineers. Platform decommissioning is conducted according to decommissioning procedures. However, there are some difficulties in market advances as no developed case studies or process models are established on how platform structures and components are to be dismantled and how the dismantled material is to be reused and recycled. Therefore, this study presented domestic and foreign regulations on the reuse and recycling of oil and gas producing offshore plant platforms, case analyses on developed decommissioning engineering, platform reuse and recycling guidelines, and platform and pipeline decommissioning processes and methods.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.75-76
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• 2024

The ovicidal effect of plant extract mixture (5%cinnamon extract + 10% citronella oil + 30% citrus oil + 10% derris extract + 20% neem extract + 25% penetrating surfactant) against several major insect pests was tested using the spraying method. In the case of stink bugs, eggs tended to die during hatching. When treated with a plant extract mixture (500-times solution), mortality for Halyomorpha halys, Riptortus clavatus, Eurydema dominulus, Trialeurodes vaprarorium, Bemisia tabaci, Spodoptera exigua, and Agrotis ipsilon reached as high as 100%. Therefore, it is believed that industrialization will be feasible in the future.

• The Korean Journal of Food & Health Convergence
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• v.6 no.3
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• pp.5-21
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• 2020

Bungkang (Syzygium polyanthum) is a medium to tall plant which produces medicinal root-bark, the plant is normally found along inland river bank and produces small white flowers and fruits. Essential oils are among the most interesting components of the plant extracts consisting mostly of monoterpenoid or sesquiterpenoids. They are used as therapeutic agents in ethno, conventional, and complementary alternative medicines. Investigation and evaluation of the essential oil of Syzygium polyanthum as well as the antibacterial, antioxidant and antifungal activity was ascertained. The experiment was performed. 100 chemical constituents were obtained and two pure compound was isolated as Eugenol (1) and Farnesol (2). Significant growth inhibition of Staphylococcus aureus, (ATCCⓒ25923) Klebsiellia pneumonia (ATCCⓒ19155), Salmonella typhi (ATCCⓒ14028) and Escherichia coli (ATCC©25922) and the fungal strains Aspergillus flavin, Aspergillus niger, Candida, tropicalis, and Fusarium oxysporium was observed from the essential oil at concentration of 500 ㎍/mL. Antioxidant potential was observed to be strong of 18.42 ㎍/mL when compared to the control of 15.23 ㎍/mL. The result indicated that the oil obtained from root-bark of Syzygium polyanthum can be considered as an agent for antioxidant, antibacterial and antifungal in pharmaceutical food and cosmetic industries trails.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.298-302
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• 2002

The essential oils were isolated by hydrodistillation and their composition determined capillary GC method with standards. The essential oil content showed significant differences between the two populations on the vegetative organs. The essential oil level of the leaves and roots was considerably higher in the Korean population at full flowering and waxy ripening stage but essential oil content of the roots was significantly higher in the Hungarian taxon at leaf rosette stage. We observed the essential oil accumulation tendency was mianly dependent on plant organs and intra-specific taxon during the vegeation period. Butylidene-phthalide was proved to be the main component of the oil in both population roots (50.9-73.3%), while dimethyl-acetate was showed as a major compound on the over-ground parts (56.7-62.0%). The qualitative composition of the essential oil in the reproductive organs concerning the identified compounds was the same as the vegetative parts with the main component ${\alpha}-phellandrene$ (4.8-28.1%) and butylidene-phtalide (9.7-16.1%), The quantitative composition showed some changes during the ontogenesis phases. Most characteristic ones are the decreasing proportion of dimethyl-acetate (from 7.3% to 1.1%) and the appearance of ${\alpha}-pinene$ (from 0.5% to 1.5%) only after fruit setting in both population.

• Carbon letters
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• v.14 no.4
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• pp.210-217
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• 2013

The synthesis of carbon nanomaterials (CNMs) by a chemical vapor deposition method using three different plant oils as precursors is presented. Because there are four parameters involved in the synthesis of CNM (i.e., the precursor, reaction temperature of the furnace, catalysts, and the carrier gas), each having three variables, it was decided to use the Taguchi optimization method with the 'the larger the better' concept. The best parameter regarding the yield of carbon varied for each type of precursor oil. It was a temperature of $900^{\circ}C$ + Ni as a catalyst for neem oil; $700^{\circ}C$ + Co for karanja oil and $500^{\circ}C$ + Zn as a catalyst for castor oil. The morphology of the nanocarbon produced was also impacted by different parameters. Neem oil and castor oil produced carbon nanotube (CNT) at $900^{\circ}C$; at lower temperatures, sphere-like structures developed. In contrast, karanja oil produced CNTs at all the assessed temperatures. X-ray diffraction and Raman diffraction analyses confirmed that the nanocarbon (both carbon nano beads and CNTs) produced were graphitic in nature.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.797-805
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• 2019

An important problem of offshore plant process piping is equipment accidents due to the removal of fine metal debris and foreign substances in the pipes that deliver fluids such as hydraulic oil, lubricating oil and thermal oil. Temporary flushing equipment to remove debris uses fluid equipment of centrifugal pump and gear pump to prevent equipment accident of offshore platform. The equipment manufacturer requires the shipyard to have a cleanliness rating inside the pipe to meet the international standards ISO4406 and NAS1638 quality levels to prevent damage to the equipment sold. The quality of the internal flushing of pipes conforms to the regulations suggested by the equipment manufacturer. In this paper, three types of electric heater capacity, which is a method of evaporating and removing water inside a pipe during an oil flushing process, were compared. In addition, the study was conducted to remove the flushing oil in the pipe and to improve oil quality.

• Journal of Urban Science
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• v.12 no.2
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• pp.53-64
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• 2023

With the development of the plant industry, there has been an increasing frequency of major accidents both domestically and internationally, emphasizing the importance of plant safety. Therefore, this study aims to investigate measures to enhance the stability of piping, a key component within the plant. Upon examining the piping, erosion, buckling, and fatigue emerged as significant risk factors among various potential hazards, leading to their selection as the primary risk factors in this study. Identifying variables that can collectively mitigate these factors, the study focuses on the material, thickness, and elbow angle of the piping. The reference piping model is established as the pipeline connecting the Skim Tank and IGF within a 300BPD oil sands modular plant in Yeoncheon, Gyeonggi-do. Utilizing the FEA analysis program ANSYS, the study conducts a variable analysis for the identified risk factors. The results of the analysis, through comparison and evaluation, provide evidence of the effectiveness of enhancing stability. It is observed that reducing the elbow angle significantly improves erosion and buckling, while changing to a material with high yield stress most significantly enhances stability when considering fatigue.