• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2789-2802
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• 2020

Small Modular Reactors (SMRs) are attracting wide attention due to their outstanding performance, extensive studies have been carried out for lead-based fast reactors (LFRs) that cooled with Lead or Lead-bismuth (LBE), and small modular natural circulation LFR is one of the promising candidates for SMRs and LFRs development. One of the challenges for the design small modular natural circulation LFR is to master the natural circulation thermal-hydraulic performance in the reactor primary circuit, while the natural circulation characteristics is a coupled thermal-hydraulic problem of the core thermal power, the primary loop layout and the operating state of secondary cooling system etc. Thus, accurate predicting the natural circulation LFRs thermal-hydraulic features are highly required for conducting reactor operating condition evaluate and Thermal hydraulic design optimization. In this study, a thermal-hydraulic analysis code is developed for small modular natural circulation LFRs, which is based on several mathematical models for natural circulation originally. A small modular natural circulation LBE cooled fast reactor named URANUS developed by Korea is chosen to assess the code's capability. Comparisons are performed to demonstrate the accuracy of the code by the calculation results of MARS, and the key thermal-hydraulic parameters agree fairly well with the MARS ones. As a typical application case, steady-state analyses were conducted to have an assessment of thermal-hydraulic behavior under nominal condition, and several parameters affecting natural circulation were evaluated. What's more, two characteristics parameters that used to analyze natural circulation LFRs natural circulation capacity were established. The analyses show that the core thermal power, thermal center difference and flow resistance is the main factors affecting the reactor natural circulation. Improving the core thermal power, increasing the thermal center difference and decreasing the flow resistance can significantly increase the reactor mass flow rate. Characteristics parameters can be used to quickly evaluate the natural circulation capacity of natural circulation LFR under normal operating conditions.

• Korean journal of food and cookery science
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• v.25 no.6
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• pp.703-711
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• 2009

Arabica coffee is classified for trading according to the New York Board of Trade(NYBOT) green coffee classification. NYBOT's grading system is based on classification derived from a defect count on a 300 g sample. In the present study, green and roasted coffees were investigated for possible correlations between the content of defective beans and sensory characteristics. Sensory evaluation was performed by expert tasters used by the Specialty Coffee Association of America(SCAA) cupping method. For green coffee, the percentage of defective beans increased. as the coffee grade decreased. Black and sour beans were not found in the NY2 grade coffee out of all natural, pulped natural, and washed coffee samples. Sour and insect damage were found in more natural coffee samples as the green coffee grade decreased. Green and broken beans were found in more washed coffee samples as the green coffee grade decreased. Flavor, clean, uniformity, aftertaste, and overall sensory characteristics were significantly different among the NY2, NY3/4 and NY4/5 grade coffee in all natural, pulped natural and washed coffee samples. The natural coffee in the NY2 sample presented the highest body characteristic. The pulped natural coffee in the NY2 sample presented the highest sweetness and balance characteristics. The washed coffee in the NY2 sample presented the highest acidity and flavor characteristics. In conclusion, the percentage of defective beans increased as sensory characteristics decreased.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.5
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• pp.1-17
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• 2014

Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.) under natural room temperature and to analyze differences between alternative and natural conditions for a practical application. Fifteen cultivars of KB were evaluated in the study. Daily and cumulative germination pattern were measured and analyzed on a daily basis. Differences were observed in germination percentage, germination pattern, days to the first germination and days to 75% germination. Germination percentage was variable with cultivars at the end of study. It was 75.75 to 90.25% under natural condition. There were considerable variations in early germination characteristics and germination pattern among KB cultivars according to germination conditions. The first germination in all entries tested was initiated between 6 and 9 DAS (days after seeding) under ISTA (International Seed Testing Association) condition. But it was observed between 9 and 12 DAS under natural condition, being 3 to 5 days later as compared with ISTA condition. On the first date of a germinating process, the germination rate was 0.25% to 25.00% under ISTA condition, while 0.50% to 13.25% under natural condition. Days to the 75% germination were 15.08 to 28.80 DAS under ISTA condition and 17.78 to 28.75 DAS under natural condition. Midnight II, Excursion and Midnight were the fastest cultivars under ISTA condition, while Odyssey the fastest one under natural condition. Regardless of germination condition, the slowest cultivar was Voyager II, being over 4 weeks to 75% germination percentage. For the most cultivars, days to 75% germination under natural room temperature condition were 1 to 8 days slower than under ISTA condition. From this study information on differences in germination characteristics and pattern among cultivars would be usefully applied for KB establishment such as golf course construction. Prior to on-site seeding, a comprehensive germination test is practically recommended due to a possible decline in germination capability during domestic distribution and storage after import.

• Fashion & Textile Research Journal
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• v.14 no.1
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• pp.64-74
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• 2012

The purpose of this study was to find purchase appraisal standard and post-purchase satisfaction for natural dyeing products. The data used for this study were collected from the women in their from 20's to 50's who are living in the regions of Busan, Ulsan, and Gyeongnam in Korea. The questionnaire of 537 copies was used for a statistical analysis. To analyze data, 2-test, t-test, Cronbach's a test, factor analysis, ANOVA, Duncan test, regression analysis, etc. were carried out. A used statistical package was SPSS 14.0. The analysis results were as follows. The purchase appraisal standards for natural dyeing products were identified as practicality and reliability, suitability of use, symbolic property of status, design property, and convenience of buying. As the analysis result for purchase appraisal standard according to the demographic characteristics, the purchase appraisal standard according to most demographic characteristics showed significant difference. The factors of post-purchase satisfaction for natural dyeing products were verified as product modification and durability, design and price, hygienic property and product quality. As the analysis results of post-purchase satisfaction for natural dyeing products according to demographic characteristics, the post-purchase satisfaction according to demographic characteristics showed significant difference. The factors affecting post-purchase satisfaction were verified as product quality, kinds of item, color change, product lifespan, color change, etc. Consequently, because the purchase appraisal standard of natural dyeing product is very various, it is necessary to enhance post-purchase satisfaction of natural dyeing products by reflecting these factors in advance at the product development stage.

• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.393-401
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• 2011

Natural Curcumin belongs to Zingiber Officinale Roscoe was known to possess natural odor, natural taste, natural color, and other pharmaceutical & chemical characteristics. Natural Curcumin extract was made to use ethanol as a solvent was to show a yellow color having state of solid powder and an active component. Natural Curcumin extract tested pharmaceutical & chemical experiment to dilute in curcumin 1%-water solution. Curcumin extract tested antimicrobial experiment using microbe, and tested dye experiment using fiber. Some conclusions in the result of characteristics experiment was obtained as follow. The result of antimicrobial experiment showed that the growth of staphylococcus aureus (ATCC-001) and aspergillus niger (ATCC-002) as microbes decreased according to passage of time. This phenomenon could know that Curcumin compoment showed influence to antimicrobial effect. Also, the result of dye experiment showed that cotton and sick with fiber dyeing dyed in direction of dark yellow color. This phenomenon could know that Curcumin extract showed influence to dyeing effect in observation of optical electron microscope(OEM.) The result of instrument analysis ascertained inorganic components of K(53.300ppm), Na(1.150ppm), Ca(0.711ppm), Ti(0.351ppm), Li(0.256ppm), Cu(0.233ppm) etcs from Curcumin component with ICP/OES, and ascertained organic components of propanoic acid(1.859), benzene(10.814), phenol(14.194) etcs from Curcumin component with GC/MSD.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.568-572
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• 2001

An industrial vibratory conveyor system is devised for large-scale feeding by the low-power, using natural frequency of the system. The important thing in this system is to determine the natural frequency and to drive by it. The purpose of this study is to build up reliance on the system with changing of element parameters for vibration characteristics of balancing type vibratory conveyor by using F.E.M. modeling. For investigating the natural frequency, modal testing is performed by using impact hammer, accelerometer and LMS/Vibration Analysis System. Experimental results are compared with F.E.M results. The results of the comparisons within the errors of less than 2 percent can verify the reliability of the F.E.M. analysis of the system. Also we can verify that the characteristics of natural frequency have linearly decreased(-6%) as adding the mass($50{\sim}600kg$). We can find that controlling driving frequency is necessary for triggering the natural frequency, but natural frequency is less affected by adding the mass on the balancing weight.

• The Research Journal of the Costume Culture
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• v.24 no.6
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• pp.777-787
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• 2016

This study was carried out in order to provide useful data for planning fabrics of summer eco-friendly fashion products. The fabrics used in this study were four cellulose fibers: cotton, cotton/mulberry blended, flax, and flax/lyocell blended. Dyeing with natural indigo was carried out under three different reducing conditions (i.e., general, eclectic, and eco-friendly) that have different reducing agent and pH levels, and hydrosulfite and glucose were used as a reducing agent. The dye uptake (K/S value) of fabrics dyed with natural indigo by a reducing condition was the highest at 660nm. Regardless of the fabrics, dye uptake was the highest under the general reducing condition and the lowest under the eco-friendly reducing condition. Under different reducing conditions, the dye uptake of natural indigo fabrics with the maximum absorption wavelength indicated a difference. The colorfastness of cellulose fabrics that were dyed with natural indigo had a rate of 4 to 5 except for rubbing fastness, which indicated good colorfastness. Additionally, natural indigo-dyed cotton and flax fabrics had good antibiosis. When the color characteristics of fabrics dyed with natural indigo were measured, all of the three reducing conditions created purple blue (PB) colors, and the color characteristics of dyed fabrics by reducing condition and fabric showed significant differences.

• Journal of the Korean Society of Costume
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• v.60 no.10
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• pp.16-27
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• 2010

Business Casual has been launched because of 'Friday Wear' in the 1990s and in Korea, the business casual has been settled under the influence of the five-day work week. The idea of business casual is that 'Business' and 'Casual wear' are combined. It is the attire that people should wear the jacket for formality and people can wear both on or off duty. As a result of the analysis, based on this, of the characteristics of men's business casual appeared in Seoul collections from 2009 till now, they can be classified in 'Classic & Traditional business casual', 'Modern business casual', 'Natural business casual', 'Feminine business casual' and 'Sporty business casual'. As a result of the analysis of the design characteristics of the Korean men's business casual and the trend, based on the content of the analysis of Seoul Collection, 'Classical Classic & the Traditional', 'Modern of the Contemporary design', 'Natural of the Natural design' and 'the Sporty business casual of the Separate Coordination' including jeans, have presented themselves. Also, as a result of the analysis of Korean business men's business casual according to the classification of the design characteristics in Chapter III, 'Classic & Traditional business casual' account for the majority and then 'Sporty', 'Modern' and 'Natural business casual' account for the rest in order. 'Feminine business casual' hasn't presented itself. As a result of the comparative analysis of the design characteristics in Chapter III & IV, Korean business men's business casual has been concentrated on 'Classical & Traditional' and the design characteristics have not appeared in variety. There has been no such audacious attempt, and items, the characteristics of coordination, colors and materials are not in variety compared to the collection. Meanwhile, as a result of the subsistent characteristics of Koran business men's business casual, the characteristics of business men's business casual can be said to represent themselves in "Separate Coordination with the previous items of formal suits".

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.94-97
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• 2007

This study aims to find the characteristics of damage and states of natural disasters at Gimhae, Gyeongsangnam-do from 1985 to 2004. Using the data of Statistical yearbook of calamities issued by the National Emergency Management Agency and Annual Climatological Report issued by the Korea Meteorological Administration. we have analyzed the cause, elements, and vulnerable regions for natural disasters. Major causes of natural disaster at Gimhae are four, such as a heavy rain, heavy rain typhoon, typhoon, storm snow, and storm. The cause of disaster recorded the most amount of damage is typhoon. The areas of Hallim-myeon, Sangdong-myeon, and Saengnim-myeon are classified the vulnerable region for the natural disasters in Gimhae. Therefore, it seems necessary to build natural disaster mitigation plan each cause of disaster to control water resources and to reduce damage for these areas.

• Journal of the Korean institute of surface engineering
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• v.26 no.6
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• pp.334-340
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• 1993

The physico-chemical properties and characteristics after thermal treatment of natural zeolite from Kampo area were studied. The physico-chemical properties of natural zeolite were studied by investigating chemical composition, x-ray diffraction pattern(XRD), scanning electronic microscope(SEM), infrared spec-tra(IR), thermal analysis(TA), and cation exchange capacity(C.E.C.), and the characteristics of natural zeo-lite after thermal treatment from $400^{\circ}C$ to $900^{\circ}C$ were compared with the natural zeolite. This study showed that clinoptilolite was the predominant costituent in natural zeolite, and the natural zeolite contained a little amount of quartz and feldspar as impurities. Zeolite mineral was seen to develop slowly by the natural alternation of volcanic ash considering the almost amorphous crystal structure. The more temperature of ther-mal treatment increased, the more adsorption capacity decreased, considering the fact that the hydroxy peak diminished on infrared spectra, and that cation exchange capacity also decreased distinctly.