• Korean Journal of Plant Resources
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• v.35 no.4
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• pp.428-434
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• 2022

Glycyrrhizae Radix is an herbal medicine vulnerable to fungi. So there are regulations on mycotoxins. Therefore, in this study, the affect of various drying methods and additional gamma irradiation (10 kGy) was studied to suppress the microbial generation of Glycyrrhizae Radix. As a result of detecting and comparing microorganisms using the dry film method for samples prepared by each of natural, hot air, freezing, microwave drying and gamma irradiation, the affect of reducing microorganisms by microwave drying and gamma irradiation was confirmed. There was no statistically significant change in the content of the active compounds between the treatment groups.

• Tribology and Lubricants
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• v.40 no.3
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• pp.103-110
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• 2024

Gas foil thrust bearings (GFTBs) are oil-free self-acting hydrodynamic bearings that support axial loads with a low friction during airborne operation. They need solid lubricants to reduce dry-friction between the runner and top foil and minimize local wears on their surfaces during start-up and shutdown processes. In this study, we evaluate the lift-off speeds and load capacity performance of a GFTB with Polytetrafluoroethylene (PTFE) surface coating by measuring drag torques during a series of experimental tests at increasing ambient temperatures of 25, 75 and 110℃. An electric heat gun provides hot air to the test GFTB operating in the closed booth to increase the ambient temperature. Test results show that the increasing ambient temperature delays the lift-off speed and decreases the load capacity of the test GFTB. An early developed prediction tool well predicts the measured drag torques at 60 krpm. After all tests, post inspections of the surface coating of the top foil are conducted. Scanning electron microscope (SEM) images imply that abrasive wear and oxidation wear are dominant during the tests at 25℃ and 110℃, respectively. A quantitative energy dispersive spectroscopy (EDS) microanalysis reveals that the weight percentages of carbon, oxygen, and nitrogen decrease, while that of fluorine increases significantly during the highest-temperature tests. The study demonstrates that the increasing ambient temperature noticeably deteriorates the static performances and degrades the surface coating of the test GFTB.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.22-30
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• 2013

This study aims to measure the thermal comfort effects of urban street trees. As the usual dry bulb air temperature does not indicate properly how the average pedestrian feels the heat of a typical summer day under the strong sunshine, we adopted the Wet Bulb Globe Temperature(WBGT). WBGT involves black globe temperature to measure the direct radiation of sun beams on our bodies, for example our heads. We measured temperatures on very sunny and hot summer days, August 3, 4, and 7, 2012, on the urban streets of Seoul, Korea. Wet bulb, globe, and dry bulb temperatures were measured under direct sunlight from 1 O'clock to 5 O'clock pm. Globe and dry bulb temperatures were measured under street tree shades nearby during the same hours. Then the WBGTs were calculated with the formulae, one for sunny outdoor spaces, and the other for shaded outdoor spaces or indoor. The results are compared with the Korean Standards Association(KS A ISO 7243). The major findings were: 1) On very sunny and hot summer days in Seoul, street tree shades lower the WBGT about 1 to 4 degrees, 2) during the hours of 3 and 4 O'clock in the afternoon, the WBGT under the tree shades are about 3 to 4 degrees lower compared to those under sunshines(approx. 29 to 32 degrees respectively), 3) This difference makes a major thermal comfort for urban pedestrians because senior citizens or weak persons are recommended to move indoor, and even healthy people are recommended stop outdoor sports and take rests in the shades when WBGT is about 32. On the other hand, if the WBGT is around 29, or 3 degrees lower, slower walking, light works or sports are allowable, 4) On site questionnaire survey confirms the thermal comforts under the tree shades, and we even could not get survey subjects on the sunny parts of the sidewalks, 5) We strongly recommend change of guidelines for urban street trees from "one row of street trees on 6m~8m intervals" to "street trees to make continuous shades".

• Journal of Families and Better Life
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• v.23 no.2 s.74
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• pp.107-125
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• 2005

Each ethnic group has a different cultural background and has developed its own culture in the name of a tradition. The interaction between different cultures is ever increasing through the process of acculturation or culture contact The purpose of this study is to provide baseline information about domestic living of Korean immigrants in Australia and Australians for a larger cross-cultural study project. As the first step, the usage of domestic space and seating styles of 52 Korean households in Melbourne were analyzed. Ethnographic research was conducted, utilizing a questionnaire. The findings of this research are as follows: 1. The most popular type of Living-Dining-Kitchen arrangement was the one which the kitchen is separated from the living and dining area. The level of satisfaction was the highest when the living room, dining room, and kitchen were all separated. 2. A laundry room was indispensable for Koreans in Australia, and they wanted to dry laundry and do ironing in there. Most people were satisfied with the toilet separated from the bathroom A drain hole on the floor of the bathroom was not indispensable for most Korean-Australians. 3. Korean-Australians tend to engage in various activities in their individual rooms, and they estimated that the size of most rooms were small. They also wanted to renovate the house to expand the rooms. 4. The seating style of Korean-Australians was mostly chair-seating. Yet, they often made beds on the floor for guests, and made kimchi sitting on the floor. Also, when they were relaxing, they were using both chair-seating and floor-seating. 5. Korean-Australians were not very satisfied with the use of floor carpets because of the dust collected on the carpets, and the difficulty to clean. It may be related to their preferred floor seating style, as well. 6. Almost all Korean-Australians take off their shoes inside of the house for hygienic reasons. They had a shoes cabinet at the entrance inside of the house. 7. The most popular heating system was ducted heating. The level of satisfaction about this was moderate because hot air contains lots of dust and it makes rooms very dry. Many were using electric blankets and their desired heating system was Ondol (heated floor). 8. Korean-Australians thought that the living room was the most important place for the family, and believed it should be decorated well to entertain guests. They also pointed out that the lighting was not bright enough in general.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.105-112
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• 2016

The drying test was carried on the globular type cow manure pellet for use in solid fuel applications. The globular type cow manure pellet fuel was sorted according to size by rotatory sieves. The three kind of drying methods such as convection hot-air drying method, infrared ray drying method and superheated steam method were used to dry the globular type cow manure pellet. Among the three kind of drying methods, superheated steam method of dry time was the shortest. The apparent specific gravity and low calorific value of dried cow manure pelltes was about $250{\sim}350kg/m^3$ and above 3,000 kcal/kg respectively. The smaller the particle size of cow manure pellets, the less drying time was required. The time was required very less for drying smaller particle size cow manure pellet when compared to larger size. In the case of the same drying condition, it has been found that reducing the particle size of cow manure fuel pellet is an important factor for shortening the drying time of the livestock manure pellet.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.241-247
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• 1990

In order to develop a type of instant tea cassia tora seed, changes of constiuent amounts before and after roasting $(3{\pm}0.5min\;at\;170{\pm}5^{\circ}C)$ effective extracting solvent and it's optimum concentration, dehydration method and sensory scores were investigated. Moisture, lipid, reducing sugar, emodin and rhein were decreased by roasting, whereas protein, and total sugar of cassia tora increased. Color intensity and extracting efficacy were also increased. Of three kinds of solvent (water, methanol and ethanol), ethanol was highest in redness and yellowness of exeracts, and filtrate yield. Effective extracting concentration of ethanol for cassia tora was 50%(V/V). Freeze dry product(FDP) and spary dry product(SDP) showed coffee and aloe-like smell, coffee like brown color, rapid soluble in cold and hot water, and fast caking in air during storage. Free sugar contents were high in order of raffinose>fructose >glucose>maltose>sucrose Metallic contents were high in order of sodium>calcium>potassium>magnesium>iron. In sensory score for color, taste and aroma, FDP and SDP were both above 8.0 point, however, of them FDP more or less higher than SDP In addion, score in developing value as an instant tea was above 8.0 point (valuable).

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.986-993
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• 1994

As a part of development of traditional foods, mugwort boogag and dry laver boogag were fried insoybean oil, and BHA or tocopherol-added soybean oil. They were wrapped up in opp vinyl film, and preserved at $4^{\circ}C(RH{\;}40{\pm}5%){\;}and{\;}25^{\circ}C(RH{\;}80{\pm}5%)$. During the storage of bobogags, acid value, peroxide value, and TBA value were investigated. Changes of sensory evaluation and texture profile were also examined. Boogags were manufactured by washing the raw materials. drying in the shade, mixing them with glutinous rice flour, and hot-air drying up it to 13 % of moisture contents after dryed it up to 80% of moisture contents on dry table for 23days, in order. These boogags were packaged to manufacture goods with dryed state or fried at $160^{\circ}C$ for 10 sec. Acid value, peroxide value, and TBA value of boogags which preserved at $4^{\circ}C$ generally appeared lower than at $25^{\circ}C$. As storage time goes by, moisture contents of bobogagas preserved at $25^{\circ}C$ increased and its quality were gradually deteriorated. When the boogags were fried in BHA(0.01%) and tocopherol (0.01%) added soybean oil, changes of acid value, peroxide value, TBA value were generally low. During the storage of bobogagas antioxidant effect of BHA was higher than that of tocopherol. Texture was inclined to decrease as storage time goes, by that of boogags preserved at $4^{\circ}C$ was a little more satisfactory. Hardness was also high.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.921-925
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• 2007

In order to optimize microbial safety and preservation in quality retention of rice flour, commercial hot-air dry (HT, 65/15 min) and microwave dry (MT, 700 watt/30 sec) treatments were developed, and in this study, natural microflora present in rice flour exposed to different storage temperature and periods were monitored. Changes in color (E) appeared to be less on the MT rice flour than on the rice flour. Effectiveness of the MT treatment showed reduction rates for total aerobic bacteria (2.62 log CFU/g), yeasts, and molds (0.37 log CFU/g). Total aerobic bacteria showed similar growth patterns of all the treatments during storage; however, the MT treatment inhibited the growth of this organism in rice flour. In conclusion, the MT treatment was found to be a suitable drying method to substitute the HT treatment in terms of quality of rice flour and microbial safety.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.2
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• pp.179-184
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• 2020

Elasticity and softness of the skin depend on the level of moisture present in the stratum corneum, which is known to be affected by various environmental changes, such as cold and hot winds and dry environments. However, not many studies have been conducted on changes in skin moisture and the degree of recovery due to individual skin differences. In the present study, we aimed to investigate the effect of warm air heating on skin hydration levels and develop moisturizing formulas to improve lowered skin hydration levels. In order to deliver warm air heating condition, heating dryer (40 ℃, 6 m/s, 30 cm apart from forearm) was applied into inner forearm of healthy subjects (male: 10, female: 39, age: 25 - 63) Among 49 subjects, 26 subjects showed significantly lowered skin hydration levels until 30 min after warm air heating exposure (lowered group). In addition, moisturizing cream with high water holding capacity was applied to forearm of 10 subjects in lowered group for 3 weeks and skin hydration levels after warm air heating were significantly improved at the levels of before application of warm air heating. From this study, we found out that there is a skin type that skin hydration levels are significantly decreased under warm air heating condition (dehydrated skin) and this dehydrated skin can be improved by moisturizing formulas with high water holding capacity.

• Corrosion Science and Technology
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• v.10 no.4
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• pp.109-117
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• 2011

The Korean Peninsula is located in the middle latitude of the northern hemisphere and has a clear 4-seasons and shows the typical temperate climate. Because of seasonal winds, it is cold and dry by a northwestern wind in the winter and it is hot and humid by a southeast wind in the summer. Also, temperature difference between the winter and the summer is large and it shows a rainy season from June to July but recently this regular trend may be greatly changed by an unusual weather phenomena. Since the Peninsula is east high west low type, the climate is complicated too. Because these geographical and climate characteristics can affect the properties of corrosion of metals and alloys, a systematic research on atmospheric corrosion in the Peninsula is required to understand and control the corrosion behavior of the industrial facilities. This paper analyzed the atmospheric corrosion factors for several environments in the Korean Peninsula and categorized the corrosivity of atmospheric corrosion of metals and alloys on the base of the related ISO standards. Annual pH values of rain showed the range of 4.5~5.5 in Korean Peninsula from 1999 to 2009 and coastal area showed relatively the low pH's rain. Annual $SO_2$ concentrations is reduced with time and its concentrations of every major cities were below the air quality standard, but $NO_2$concentration revealed a steady state and its concentration of Seoul has been over air quality standard. In 2007, $SO_2$classes of each sites were in $P_0{\sim}P_1$, and chloride classes were in $S_0{\sim}S_1$, and TOW classes were in ${\tau}_3{\sim}{\tau}_4$.That is, $SO_2$ and chloride classes were low but TOW class was high in Korean Peninsula. On the base of these environmental classes, corrosivity of carbon steel, zinc, copper, aluminium can be calculated that carbon steel was in C2-C3 classes and it was classified as low-medium, and zinc, copper, and aluminium showed C3 class and it was classified as medium.