• Journal of Power System Engineering
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• v.19 no.3
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• pp.16-21
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• 2015

Nitrous oxide($N_2O$) concentration in the atmosphere has been constantly increased by the human activities with industrial growth after the industrial revolution. One of factors to increase $N_2O$ concentration in the atmosphere is the $N_2O$ emission caused by the combustion of marine fuel. Especially, a sulfur component included in marine fuel oils is known as increasing the $N_2O$ formation in diesel combustion. Form this point of view, $N_2O$ emission from a ship is not negligible. On the other hand, Exhaust gas recirculation(EGR) that have thermal, chemical and dilution effect is effective method for reducing the NOx emission. In this study, an author investigated $N_2O$ reduction by using EGR on a direct injection diesel engine. The test engine was a 4-stroke diesel engine with maximum output of 12 kW at 2600rpm, and operating condition of the engine was a fixed load of 75%. The experimental oil was a blend-fuel that were adjusted with sulfur ratio of 3.5%, and EGR ratio of 0%, 10%, 20% and 30%. In conclusion, diesel fuel that contained 3.5% sulfur component increased $SO_2$ emission in exhaust gas, and increment of EGR ratio reduced NO emission. Moreover, $N_2O$ emission was decreased as over 50% at EGR ratio of 10% and reduced 100% at EGR ratio of 30% compared with $N_2O$ emission of 0% EGR ratio.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.221-226
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• 2003

Genetic variation of Perilla germplasms was investigated using RAPD markers. Forty-two Perilla frutescens lines and cultivars collected form locals were subjected to RAPD analysis using 220 primers. Among them only 13 primers showed polymorphic bands and these 13 primers provided a total of 144 bands, consist of 115 polymorphic and 29 monomorphic ones. The polymorphic bands were subjected to phylogenetic analysis using UPGMA and maximum parsimony (MP) methods. In the UPGMA method, similarity coefficiency of 42 Perilla frutescens lines and cultivars ranged from 0 to 0.7842. The dendrogram of 42 lines and cultivars obtained through UPGMA method resulted in two major groups, and the similar clustering pattern was found by MP method, suggesting Perilla germplasms utilized in this study truly can be divided into two major groups. Although the two major groups were consistent roughly with their phenotypes (under of node, weight of 1,000 grains, and oil content), in detail, much inconsistency also was present.

• Tribology and Lubricants
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• v.30 no.5
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• pp.303-310
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• 2014

In order to reduce friction and improve reliability, researchers have applied various surface texturing methods to highly sliding machine elements such as mechanical seals and piston rings. Despite extensive theoretical research on surface texturing, previous numerical results are only applicable to isothermal and iso-viscous conditions. Because the lubricant flow pattern of textured bearing surfaces is much more complicated than that for non-textured bearings, the Navier?Stokes equation is more suitable than the Reynolds equation for the former. This study carries out a thermohydrodynamic (THD) lubrication analysis to investigate the lubrication characteristics of a single micro-dimpled parallel thrust bearing cell. The analysis involves using the continuity, Navier?Stokes, energy, temperature?viscosity relation, and heat conduction equations with the commercial computational fluid dynamics (CFD) code FLUENT. This study discretizes these equations using the finite volume method and solves them using the SIMPLE algorithm. The results include finding the streamlines, pressure and temperature distributions, and variations in the friction force and leakage for various dimple radii and depths. Increasing the dimple radius and decreasing the depth causes a recirculation flow to form because of a strong vortex, and the oil temperature greatly increases compared with the non-textured case. The present numerical scheme and results are applicable to THD analysis of various surface-textured sliding bearings and can lead to further study.

• Architectural research
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• v.15 no.3
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• pp.151-158
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• 2013

Offshore oil and gas process plants are exposed to hazardous accidents such as explosion and fire, so that the structural components should resist such accidental loads. Given the possibilities of thousands of different scenarios for the occurrence of an accidental hazard, the best way to predict a reasonable size of a specific accidental load would be the employment of a probabilistic approach. Having the fact that a specific procedure for probabilistic accidental hazard analysis has not yet been established especially for explosion and fire hazards, it is widely accepted that engineers usually take simple and conservative figures in assuming uncertainties inherent in the procedure, resulting either in underestimation or more likely in overestimation in the topside structural design for offshore plants. The variation in the results of a probabilistic approach is determined by the assumptions accepted in the procedures of explosion probability computation, explosion analysis, and structural analysis. A design overpressure load for a sample offshore plant is determined according to the proposed probabilistic approach in this study. CFD analysis results using a Flame Acceleration Simulator, FLACS_v9.1, are utilized to create an overpressure hazard curve. Moreover, the negative impulse and frequency contents of a blast wave are considerably influencing structural responses, but those are completely ignored in a widely used triangular form of blast wave. An idealistic blast wave profile deploying both negative and positive pulses is proposed in this study. A topside process module and piperack with blast wall are 3D FE modeled for structural analysis using LS-DYNA. Three different types of blast wave profiles are applied, two of typical triangular forms having different impulse and the proposed load profile. In conclusion, it is found that a typical triangular blast load leads to overestimation in structural design.

• The Research Journal of the Costume Culture
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• v.28 no.3
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• pp.376-388
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• 2020

The purpose of this study was to analyze the current status and contents of color-related education programs as lifelong education and to determine the necessity of color education and directions for future development. The findings of this study, first show that the general welfare center, which is striving to develop abilities and promote welfare, was opened mainly for professional education, rather than hobby-oriented education. Accordingly, pricing was set at a lower level than the three institutions and centers, but without a variety of programs or hobby-oriented courses. Second, as the purpose of the set-up is to be established, the general welfare center should be considered an area for hobbies along with expertise, and various courses should be opened. Although the department store's cultural center focused on programs for cultural and leisure use and promotion, it is necessary to extend the program to attempt to approach it in a short-term process rather than a one-time class. The lifelong education center established as a subsidiary of the university' was opened as an area for of painting such as oil painting and watercolor and drawing which have much in common school should learn and start basic theory and practice, so there was much difference. Third, if it is changed to a developed form of color-oriented education according to the purpose of each center and institution presented in the results of this research, a good response will be possible to further improve the quality of life and develop professionalism and creativity.

• Polymer(Korea)
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• v.28 no.2
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• pp.103-110
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• 2004

The biodegradable poly($\varepsilon$-caprolactone) (PCL) microcapsules containing tocopherol were prepared by oil-in-water emulsion solvent evaporation method. The features of the microcapsules were investigated in the manufacturing conditions and degradation behaviors. The form and structural feature of the microcapsules were measured by scanning electron microscope and X-ray diffraction, respectively. The surface free energy of the microcapsules was executed using contact angle measurement. As a result, the microcapsules were more stable and spherical with poly(vinyl alcohol) given in a surfactant. The surface free energy and crystallinity of microcapsules were decreased with increasing the core concentration, and degradation of PCL was occurred after 21 days. The release behaviors were examined by Uv/vis. spectrophotometer. It was found that the release rate of the microcapsules was increased with increasing the stirring rate, due to the increased interface between microcapsules and release media.

• The Journal of the Korean Society for Microbiology
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• v.13 no.1
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• pp.25-30
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• 1978

Among clincal isolates, most strains of Serratia marcescens were belonged to nonpigmented form, and several attempts were undertaken for the rapid and simple identification of these strains. Prodigiosin production of non-pigmented strains was uniformly negative in many kinds of solid media as well as in nutrient agar added with various amino acids and thiamine. On blood agar, colonies of S. marcescens turned gradually to grey or dark color by the lapse of incubation period and this characteristic seems to be able to utilize as an indicator for a primary isolation, and also generally paralleled with the results of dehydration of Tween 80 and lipase activity in soy bean oil medium although these reactions were by no means specific to S. marcescens. In order to rule out these non-specific reactions, other tests such as oxidase and sucrose fermentation are required for the final confirmation of this species.

• Mass Spectrometry Letters
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• v.2 no.1
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• pp.1-7
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• 2011

China's rapid economic growth has resulted in significant environmental side effects. Therefore, China has been interested in reducing her dependence on foreign oil and gas by developing technologies needed for hydrogen, in addition to her increasing energy mix of nuclear and renewable energy form, such as solar and wind power. There are three isotopes of hydrogen, i.e. protium (P or H), deuterium (D), and tritium (T). Both deuterium and tritium are important materials in nuclear fuel cycle industry. Tritium is one of the critical radioactive nuclides. Planning for and implementing contamination control as a part of normal operation and maintenance activities is an important function in any hydrogen facility, especially tritium facility. The development of hydrogen isotopes analysis is the key issues in this area. Mass spectrometry (MS) with medium (about 600) and high resolution (> 1,400) is commercially available; however, the routine analysis of hydrogen isotopes is done with low-resolution MS (< 200) in China. This paper summarizes the progress of MS measurement technology for hydrogen isotope abundance in China, focusing on our lab's research program and technical status. An analyzing method has been introduced for accurate measurement of tritium abundance in the H.D.T system by low resolution MAT-253 MS. The quotient of compression ratio coefficient is determined by building up equipment for laboratory-scale preparation of secondary standard gases and by considering the difference in sensitivity between hydrogen isotopes. The results show that the measured value is reproducible within the relative error range of 0.8% for gas samples of different tritium abundance.

• Korean journal of food and cookery science
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• v.6 no.1
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• pp.41-51
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• 1990

A special form of questionaire was prepared and distributed to 502 housewives in seoul from Feb. 8th to 22nd in 1989. The results were as follows: In Cooking methods, they tended to follow in the steps of their mother, and it took about half an hour or an hour to prepare a meal. They cooked fried foods once or twice a month. Whenever they fried foods they need new oil. Followings were details of cooking method mainly used by housewives. Fishes were tended to be roast, vegetables to be dressing and seasoning. Highly milled boiled rice was best preferred as the cheif food, and it was cooked by following procedure; First rice was washed, and steeped in water for the time being. Next, the water was poured out and water was filled again, then rice with the water was boiled. Fish Chige was cooked in the way that fish was put into the boiled soup. Fermented sao-bean paste Chige was cooked using water in which rice had been washed. Hard-boiled beef with soy sauce was made using the method that soy sauce was properly poured after beef was boiled. A Spinach was boiled shightly with salty water. In view of those results, there were many cases that housewives did not only utilize their knowledge about foods in real dietary life, but also fell short of endeaver to do so. They chiefly made use of the cooking methods instructed from their mother or husband's mother. In conclusion, in order to illuminate housewives to have an exact nutritional knowledge about foods and cooking methods getting out of the loss of nutritions, nutritional education program must be provided for housewives.

• Preventive Nutrition and Food Science
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• v.18 no.2
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• pp.150-156
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• 2013

A total of 48 different volatile oils were identified form P. brevitarsis larvae by gas chromatography/mass spectrometry (GC/MS). Acids (48.67%) were detected as the major group in P. brevitarsis larvae comprising the largest proportion of the volatile compounds, followed by esters (19.84%), hydrocarbons (18.90%), alcohols (8.37%), miscellaneous (1.71%), aldehydes (1.35%) and terpenes (1.16%). The major volatile constituents were 9-hexadecenoic acid (16.75%), 6-octadecenoic acid (14.88%) and n-hexadecanoic acid (11.06%). The composition of fatty acid was also determined by GC analysis and 16 fatty acids were identified. The predominant fatty acids were oleic acid ($C_{18:1}$, 64.24%) followed by palmitic acid ($C_{16:0}$, 15.89%), palmitoleic acid ($C_{16:1}$, 10.43%) and linoleic acid ($C_{18:2}$, 4.69%) constituting more than 95% of total fatty acids. The distinguished characteristic of the fatty acid profile of P. brevitarsis larvae was the high proportion of unsaturated fatty acid (80.54% of total fatty acids) versus saturated fatty acids (19.46% of total fatty acids). Furthermore, small but significant amounts of linoleic, linolenic and ${\gamma}$-linolenic acids bestow P. brevitarsis larvae with considerable nutritional value. The novel findings of the present study provide a scientific basis for the comprehensive utilization of the insect as a nutritionally promising food source and a possibility for more effective utilization.