• Progress in Superconductivity
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• v.8 no.2
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• pp.186-192
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• 2007

High $J_c\;YBa_2Cu_3O_{7-x}$ superconducting films have been fabricated $LaAlO_3(100)$ substrate by MOD method using dichloroacetic acid(DCA) as chelating solvent for preparing precursor solution. Heating rate was varied in order to optimize the calcination heat treatment condition in DCA-MOD method. Coated films were calcined at lower temperature up to $500^{\circ}C$ in flowing humid oxygen atmosphere. The heating rate was calcined from $13.3^{\circ}C/min\;to\;0.28^{\circ}C/min$. Conversion heat treatment was performed $800^{\circ}C$ for 2 h in flowing Ar gas containing 1000 ppm oxygen with a humidity of 9.45%. Surface and cross sectional SEM microstructures showed that particle sizes were increased with heating rate at a calcination step. The amount of pores was increased with heating rate in the calcined films. Dense microstructure and sharp texture were developed in an YBCO films after conversion heat treatment. A high critical current density (Jc) of $1.26MA/cm^2$ (@77 K and self-field) was obtained for the YBCO film which was prepared with a heating rate of $0.28^{\circ}C/min$.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.160-165
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• 2005

Schools have significant and serious indoor environmental health problem, of which indoor air quality (IAQ) in school building may affect the health of the students and indirectly affect learning performance. Schools are of special concern when regarding indoor exposure to air pollutants, because students are particularly sensitive to pollutants and spend a significant amount of time in that environment. Therefore researches for improvement of indoor air quality have been developed such as installation of air cleaning device, ventilation system, titanium dioxide(TiO2) coating and so on. However, it is difficult to evaluate the magnitude of improvement of indoor air quality in field study because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. In this study, evaluation of reduction of formaldehyde emission rate in school indoor environments by far-Infrared ray coating material was carried out using mass balance model in indoor environment. we proposed the evaluation method of magnitude of improvement in indoor air quality, considering outdoor level and ventilation. Since simple indoor concentration measurements could not properly evaluate the indoor air quality, outdoor level and ventilation should be considered when evaluate the indoor air quality.

• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.210-214
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• 1997

The experiment was conducted to obtain basic informations on the effects of key environments and fungicides on the sporulation, conidial germination and hitial growth of the hyphae of grape powdery mildew fungus Uncinula necator. Maximum sporulation occurred at RH 75~96% in vitro adiusted with sulfuric acid solution. Conidial germination and initial growth of the hyphae were better at 5% water agar than distilled water, and best at $26^{\circ}C$ and pH 5.0 of the substrates. Germination occurred equally well at light intensity of below 100 lux or dark condition, which was better at water agar supplemented with leaf extract 30% than pure water agar. The water agar supplemented with triazole fungicides reduced conidial germinations and initial growth of the hyphae signifcantly, in proportion to the increase in concentration of the fungicides, but the maguitude of reduction depended on the fungicides. Particularly in myclobutanil, reduction rate was very low as increased in concentration.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.11-21
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• 1999

This objective of this paper is to investigate the evaluation and indiction of human thermal comfort in building environment. The issue of defining the boundaries of acceptable thermal comfort conditions in buildings and urban may have significant implication for building design and also may have urban design by climate considerations. And then it is to apply the thermal comfort condition to environmental design by using passive methods in Korea. Since 1920. architects have conducted studies to measure thermal comfort in houses under hot and humid conditions, while industrial hygienists have studied the effects of temperature and humidity on the performance of factory workers. Thermal comfort can be influenced by many variables. This paper conducted to review the previous researches and the human heat balance equation, and to analyse in order to reveal the meaning and usage of the thermal comfort index in two traditional essays, Fanger's PMV and Gagge's ET* Their comfort indexes compared with each other. They were based on human heat balance equation and psychological and physiological responses in the laboratory tests. The researchers and the architectural engineers using thermal comfort index shall be careful in decided the use of indexes and be necessary to recognize the value concept of the design criteria for thermal comfort. Therefore, The opinion of the authors is that different comfort standards have to apply for each building and urban with different climatic conditions.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.753-761
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• 2014

Growth and flowering of Cymbidium 'Red Fire' and 'Yokihi' plants were examined in a greenhouse with cooling systems in summer, and with night interruption (NI) lighting in winter as a forcing culture system. The greenhouse was divided into two sections with separate cooling controls during the summer season. One section was cooled by a mist system (mist), while the other section was cooled by a shade screen (shade). During the winter, the greenhouse was redivided into three sections within each cooling system. Plants were grown with NI either at a low light intensity of $3-7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(LNI) or a high l ight intensity of $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(HNI) u sing h igh-pressure sodium l amps during the 22:00-02:00 HR. The control plants were grown under 9 h short-day condition. NI for 16 weeks and cooling for 9 weeks were employed twice during the 2 years of the experimental period. The air temperature was approximately $2^{\circ}C$ lower in the mist than in the shade and the relative humidity was 80 ${\pm}5%$ in the mist compared to $55{\pm}5%$ in the shade. The daily light integral in the mist section was 48% higher than in the shade section. The time from initial planting to flowering pseudobulb emergence decreased with both LNI and HNI for both cultivars, regardless of the cooling treatments. Under NI conditions, however, between 60% and 1 00% of plants of both cultivars flowered in the mist, whereas no or 20% of 'Red Fire' or 'Yokihi' plants, respectively, flowered in the shade treatment over 2 years. Plants grown under the mist had bigger pseudobulbs than those grown in the shade under both NI treatments. These results show that commercial use of NI in winter and a mist cooling system in summer would decrease crop production time to 2 years and increase profits in Cymbidium forcing culture.

• Journal of Life Science
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• v.9 no.1
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• pp.44-49
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• 1999

A study was conducted to investigate the possibility of processing seasoned and semi-dried right-eyed flounder (Pseudopleuronects herzensteini) and to examine its quality during storage at $\pm$$3^{\circ}C$ by analyzing the factors such as moisture content, pH, volatile basic nitrogen (VBN), viable cell count and peroxide value (POV). For processing of the seasoned and semi-dried product, optimum conditions of drying temperature and drying time were $20^{\circ}C$ and 4 hrs, respectively, under 50$\pm$5$\%$ of relative humidity and 2 m/sec of air blast speed. The shelf-lives of the products by vacuum-packaging method in nylon/polyethylene/linear low density polyethylene (0.015/0.045/0.040 mm) laminated film bag were 35 and 16 days during storage at $-3^{\circ}C$ and $3^{\circ}C$, respectively.

• Fashion & Textile Research Journal
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• v.22 no.2
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• pp.250-260
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• 2020

The purpose of the present study was to explore the most effective body region and cooling temperature to alleviate heat strain of workers in hot environments. We developed liquid cooling hood, vest, sleeves and socks and applied the water temperatures of 10, 15, 20, and 25℃ through the liquid cooling garments in a hot and humid environment (33℃ air temperature and 70% RH air humidity). A healthy young male participated in a total of 16 experimental trials (four cooling garments × four cooling temperatures) with the following protocol: 10-min rest, 40-min exercise on a treadmill and 10-min recovery. The results showed that rectal temperature, mean skin temperature, and ratings of perceived exertion during exercise; heart rate and diastolic blood pressure during recovery; and total sweat rate were lower for the vest condition than other garment conditions(p < .05). However, there was no differences in mean skin temperature among the four cooling garments when we compared the values converted by covering area(%BSA). When we classified the results by cooling temperature, there were no consistent differences in thermoregulatory and cardiovascular responses among the four temperatures, but 25℃ water temperature was evaluated as being the most ineffective cooling temperature in terms of subjective responses. In conclusion, the results indicated that wearing cooling vest with < 20℃ cooling temperature can alleviate heat strain of workers in hot and humid environments. If the peripheral body regions are cooled with liquid cooling garments, larger cooling area with lower cooling temperature than 10℃ would be effective to reduce heat strain of workers. Further studies with a vaild number of subjects are required.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.45-53
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• 2012

This study was performed to analyze test results on drying shrinkage for concrete specimens mixed with various constituents in concrete mixes. Test variables are coarse aggregate types(Limestone, Sandstone, Granite, Andesite, Gneiss), fine aggregate types(natural sand, crushed sand) and cement amounts(normal strength, high strength). Epoxy coating of(U&V-H(A,B)) was applied onto the specimen surface to simulate diverse volume surface ratios(22.2, 40, 85.7, 150, 200, 300) with different specimen sizes. The experiments had been executed during 1,014 days at a condition of $20^{\circ}C$ and relative humidity of 60% in environmental chambers. Test results showed that shrinkage strain from the specimen equivalent to real pavement decreased to 39% compared to the standard specimen recommended by KS. Test results also showed that shrinkage strain of the specimen mixed with Limestone was 56~76% of that with Sandstone, thus Limestone mix seems to be suitable to the concrete pavement.

• Journal of environmental and Sanitary engineering
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• v.24 no.2
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• pp.17-30
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• 2009

In Iksan city, there have been a lot of complaints caused by offensive odor from residents living near the public environmental infrastructures and the Iksan industrial complex. To solve these problems, it is important to know the present condition of odor pollution level in these areas, the emission characteristics of malodorous gases in temporal and spatial variations in addition to meteorological components, and the facilities of major sources emitting malodorous compounds. The objectives of this study is to make the odor monitoring network for 20 people who lived and worked in areas where the environmental infrastructures and the Iksan industrial complex are located and their neighboring areas for six months from June 1st to October 31st in 2008 in Iksan and to monitor the temporal and regional frequency and characteristics of odor intensity using direct olfactory methods. As a result of odor monitoring, the highest frequency of sensed odor per month and 20 people for six months was found to be 107 in July, followed by 84 in September, 80 in August, 54 in June, 38 in October, respectively. Odor intensity trend showed a regional trend in the decreasing order of Dongsan-dong, Busong-dong, and Palbong-dong. Odor was widely perceived from night through next morning and considered as the sense of excreta, chemicals, sewage, compost, waste, etc. When high odor intensity was sensed, there were constant meteorological characteristics: relative humidity was 80~90%, wind speed was less than 0.5~1 m/sec, and main wind directions were from the east, the southeast, and the south.

• Korean Journal of Medicinal Crop Science
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• v.26 no.5
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• pp.401-407
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• 2018

Background: In Korea, seeds of Panax ginseng C. A. Meyer need to be stored under cold temperature and high humidity condition for months to break physiological dormancy, making storage difficult until spring-sowing. This study was conducted to test the effects of seed storage conditions and seed treatment on the emergence of seedling after spring-sowing in a nursery greenhouse. Methods and Results: After dehiscence, endocarp dried seeds in mild or completely, and wet seeds were stored in $2^{\circ}C$ and $-3.5^{\circ}C$ during winter. Storage at $-3.5^{\circ}C$ resulted in a lower emergence rate (ER) than that at $2^{\circ}C$, and additional cold ($2^{\circ}C$) treatment before or after storage at $-3.5^{\circ}C$ increased the ER. Endocarp dehydration prevented pre-germination at $2^{\circ}C$ storage and increased the ER of seeds stored at $-3.5^{\circ}C$. ER was also dependent on the batch of seeds. However, seed treatments before sowing had only limited effects on ER. Root loss was the main reason for damping-off; prolonged cold storage of seeds increased damping-off, as the detection of pathogens was not high. Conclusions: This study showed that storage conditions such as temperature and moisture content of seeds, affect the ER after spring-sowing and vitality of seedlings, suggesting further attention on seed control for secure seedling stands after spring-sowing.