• Korean Journal of Veterinary Research
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• v.10 no.2
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• pp.73-80
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• 1970

This report summarized the results of the post-mortem diagnosis oil the 1,785 fowl live and dead during the calender year of 1966 to 1968. The disease incidences in order were; leucosis complex(21.9%) newcastle disease (10.4%), coccidiosis (6.6%) and mismanagement(3.9%). There were also a number of other diseases common to tb,e poultry flocks such as avian mycoplasmosis, pullorum disease and, nutritional disorder etc.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.127-133
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• 1996

The development of high resolution capillary columns and a large variety of different detectors led to a strong position of gas chromatography in instrumental analysis. Every effort has been made to solve sophisticated separation problems by column switching. Nowadays, several systems are commercially available for this purpose. The principle and the capabilities of multidimensional gas chromatography(MDGC) are illustrated by different applications in the field of modern flavor and essential oil research.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.194-201
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• 2015

A lubricant used in the transport sector have been developed for the purpose of improving vehicle performance. To improve the engine oil for some terrible conditions, various studies have been conducted to improve vehicle performance. There are limitations in development of lubricant for the economic point, but various additives have beed developed in the technical point. Recently, government tried to prohibit reckless use of additives in base oil because of the environmental issues. The institutionalized quality standards of the additives has been estabilished. In this study, physicochemical properties and environmental effect of vehicle engine oils in domestic sector were investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3761-3767
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• 2009

This study was investigated to determine the combustion characteristics, decomposition efficiency, and the flue gas concentrations after combustion in the high temperature reactor($1,250{\sim}1,400^{\circ}C$, 1 atm) for the liquid wastes(waste oil and waste solvent) generated from the industrial complex. The concentration of nitrogen oxide(NOx) is decreased and the synthetic gas is increased when the mass ratio of $O_2$/waste is about 1.53 because the reaction condition was changed to reduction state. And BTEXs(benzene, toluene, ethylbenzene, xylene) are decomposed more than 99.99%. If the highly concentrated liquid waste (waste oil and waste solvent) is treated under the operating conditions suggested by this study, our treatment method for the liquid waste was found to be proper because of the contaminants emission concentration is very low. In addition, the synthetic gas after combustion can be used as an alternative fuel.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.809-813
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• 1999

D phase emulsification has been developed and elucidated the emulsification mechanism by using phase diagrams. The process of D phase emulsification begins with the formation of isotropic surfactant solution, follows by formation of oil-in-surfactant (O/D) gel emulsion by dispersion of octamethylcyclotetra siloxane(OMCS) in the surfactant solution. Polyols were essential components for this experiments. To understand the function of polyols, the solution behaviors of nonionic surfactant/oil/water/polyol systems were investigated by the ternany phase diagrams of polyoxyethylene oleyl ether/OMCS/propylene glycol(PG) aqueous solutions. The solubility of oil in the isotropic surfactant phase was increased with the addition of PG. D phase emulsion was formed in the range of 70~90% of OMCS and 2.0~3.0 dyne/cm of interfacial tension and the structure was homogenious spherical and O/W type and its diameter was about $10{\mu}m$.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.75-81
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• 2017

Objectives : The present study was designed to investigate effects of mixed extracts (9:1, v/v) of Hwangryunhaedoktang, Chamaecyparis obtusa essential oil. We evaluated the antimicrobial and antioxidant activity by manufacturing mixed extracts as the materials for functional medicinal herb cosmetics. Methods : We performed antimicrobial were tested microbes (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Candida albicans, Propionibacterium acnes) by disc diffusion method and measure clear zone. Antioxidant activities were measured by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. Results : Antimicrobial activities of mixed extracts against S. epidermideis, P. acnes, S. aureus, E. coli, and Candida. A were $10.9{\pm}3.0mm$, $16.9{\pm}2.0mm$, $9.2{\pm}2.0mm$, $10.3{\pm}1.0mm$, $11.8{\pm}3.0mm$ respectively. The Chamaecyparis obtusa essential oil had the highest antimicrobial activities against S. epidermideis, P. acnes, S. aureus, E. coli, and Candia. A and clear zone of microbes ware $16.7{\pm}3.0mm$, $28.8{\pm}0.2mm$, $15.9{\pm}2.0mm$, $11.5{\pm}1.0mm$, $16.3{\pm}3.0mm$. Hwangryunhaedoktang extract showed antimicrobial activity but only P. acnes and S. aureus The antioxidant activities of the mixed extracts were tested through the evaluation of DPPH radical scavenging activity. The 100 % mixed extracts were found to have 90 % DPPH radical scavenging activity. The mixed extracts was presented similar antioxidant activities compared with that of ascorbic acid. As a result, A mixture extract is expected to have antimicrobial effects and free radical scavenging activity was found. Conclusions : Accordingly, It can be concluded that mixed extracts has the potential to cosmetic material.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.8.1-8.10
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• 2012

Objectives: The goal was to model and quantify the atmospheric concentrations of volatile organic compounds (VOCs) as the result of the Hebei Spirit oil spill, and to predict whether the exposure levels were abnormally high or not. Methods: We developed a model for calculating the airborne concentration of VOCs that are produced in an oil spill accident. The model was applied to a practical situation, namely the Hebei Spirit oil spill. The accuracy of the model was verified by comparing the results with previous observation data. The concentrations were compared with the currently used air quality standards. Results: Evaporation was found to be 10- to 1,000-fold higher than the emissions produced from a surrounding industrial complex. The modeled concentrations for benzene failed to meet current labor environmental standards, and the concentration of benzene, toluene, orthometa- para-xylene were higher than the values specified by air quality standards and guideline values on the ocean. The concentrations of total VOCs were much higher than indoor environmental criteria for the entire Taean area for a few days. Conclusions: The extent of airborne exposure was clearly not the same as that for normal conditions.

• Earthquakes and Structures
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• v.20 no.1
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• pp.109-122
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• 2021

Significant progress in the oil and gas industry advances the application of pipeline into an intelligent era, which poses rigorous requirements on pipeline safety, reliability, and maintainability, especially when crossing seismic zones. In general, strike-slip faults are prone to induce large deformation leading to local buckling and global rupture eventually. To evaluate the performance and safety of pipelines in this situation, numerical simulations are proved to be a relatively accurate and reliable technique based on the built-in physical models and advanced grid technology. However, the computational cost is prohibitive, so one has to wait for a long time to attain a calculation result for complex large-scale pipelines. In this manuscript, an efficient and accurate surrogate model based on machine learning is proposed for strain demand prediction of buried X80 pipelines subjected to strike-slip faults. Specifically, the support vector regression model serves as a surrogate model to learn the high-dimensional nonlinear relationship which maps multiple input variables, including pipe geometries, internal pressures, and strike-slip displacements, to output variables (namely tensile strains and compressive strains). The effectiveness and efficiency of the proposed method are validated by numerical studies considering different effects caused by structural sizes, internal pressure, and strike-slip movements.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.379-389
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• 2000

This study was focused on the investigation for the heavy metal contamination of soils derived from Yoecheon Industrial Complex in Chonnam Province. Total 201 soil samples including farmland, paddy, forest and playground soils were collected, extracted by 0.1N HCl and analyzed for Cd, Cu, Cr, Fe, Mn and Zn using AAS. Most pH values in soils were weak acidic ranges of 4-6, while some of them were over 8.0. Concentrations of Cd, Cu, Fe and Zn in the soils tend to be relatively high around the Au-Ag mine area, railroad stations and oil station, however, those of Cr, Mn and Pb show high at the northside of Pohang Steel Co (POSCO). Cadmium-Zn couples, and Cd-Zn and Zn-Cr couples have relatively good correlations in the farmland soils and paddy soils, respectively. Concentrations of Cd, Fe and Zn with depth tend to be higher in the top soils than in the bottom soils, but those of Cu and Pb do not show regular variations with depth.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.25-31
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• 2007

In a petrochemical complex, large amount of hydrogen is produced as a by-product and used as a fuel in petrochemical and oil refinery plants. By recycling this byproduct hydrogen as a raw material, the value of hydrogen can be greatly improved. This paper proposes a design methodology for optimal hydrogen recycle network between plants in petrochemical complex by analyzing the hydrogen pinch, required cost and constraints.