• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.403-409
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• 2007

This study was carried out to recommend the systematic improving practice for the effective operation of septic tank, and the evaluation of its BOD and nutrient removal efficiency depending on process, the survey of characteristics of FRP material, and the suggestion of optimum septic tank model within sewage treatment area. The average BOD concentration and BOD removal efficiency of septic tank which was carried out the cleaning periodically in 63.9 mg/L and 77.8%, shows good quality better than the septic tank which was not carried out the cleaning regularly. Maximum load of tensile, flexural and compressive strength increased in proportion to its thickness, and the contents standard 25% of glass fiber required upgrade over than 30%. Configuration and performance for the optimum of the septic tank suggests that over $0.75m^3$ of the effective total volume, adding to over $0.25m^3$ a man for more than 5 men of the treated person, retention time should be within one day. Improving plans about facility and materials quality of the septic tank have an obligation that protective wall ought to install on the concrete bottom and side faces to prevent crumble or transform from loading of the ground or upper part of the structure on the tank setting. And it is eliminated the uneffective resisting pressure and it keeps off circulate imperfect products by strengthening of the test methods such as stretching strength, pressing strength, glass fiber contents and thickness.

• Journal of Korean Public Health Nursing
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• v.10 no.2
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• pp.51-60
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• 1996

This study was conducted to provide basic knowledges of effective environmental control of patients with allergic rhinitis. From July to October 1995, 58 dust samples Were drawn from the bedrooms of patients with allergic rhinitis who were registerd at an allergy clinic of a hospital. Those samples were examined for the amount of house mite allergens & dusts. The data were analysed by using ANOVA and Pearson correiation coefficients. The results were as follows : 1. As for the amount of house mite allergens in terms of environmental factors, the amount of house mite allergens of using washing water temperature of bedding above than $55^{\circ}C$ was significantly lower than that of below $54^{\circ}C$. Other environmental factors such as type of house, area of bed room floor, bed in bedroom, bedroom cleaning by vacuum cleaner, days after bedding washing, relative humidity of bedroom were relate to the amount of house mite allergens. 2. As for the amount of dusts in terms of environmental factors, the amount of dusts of days of days after bedding washing more than 15 days was significantly lower than thant of less than 15days. Other environmental factors such as type of house, area of bedroom floor, bed in bedroom, bedroom cleaning by vacuum cleaner, was hing water taemperature of bedding, relative humidity of bedroom were not relate to the amount of dusts. 3. There was a significant positive correlation between the amount of house mite allergens and the amount of dusts. It may be conclusively said. the amount of dusts and house mite allergens were closely associated with the washing temperature and days after washing of bedding. Hence. intensive instruction for the methods of bedding washing was needs of the patients with allergic rhinitis.

• Journal of The Korea Institute of Healthcare Architecture
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• v.26 no.3
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• pp.7-16
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• 2020

Purpose: As communicable disease, COVID-19, pandemic strikes over the world, it is critically bewared that air travel possibly be a major pass way to deliver the infectious disease virus. Especially the airplane could be an unique environment to cultivate the virus spreaders. In order to keep the continuous safe airway as well as the industry, related international associations and organizations have been published the guidelines for the prevention and control the infectious disease through the all aspects of aviation. By reviewing the guidelines, focusing on the in-flight infection prevention and control, this study would not only inform a summary of the international guidelines but also provide an essential and general consideration for related research or guideline study. Methods: Guidelines of 5 major countries are reviewed, which has been seriously influenced by COVID-19 : U.S., Canada, E.U., Australia and China. The items of the guidelines are re-categorized as its similarity and structure by applicable cases. Results: The result of this study shows that each guideline seems to share a major structure and issue such as identifying sick traveler, sick passenger care, and cleaning even though that of China has a different since it used to consider the flight conditions based on 3 levels of infection risk. For sick passenger care, the guidelines includes crew safety, service level, sick passenger isolation, and cleaning. Implications: A published guideline as a public manual could be to prevent and control the in-flight infection efficiently and promptly. It also could provide a confidence of knowledge and educate for all users to prepare the in-flight emergency as well.

• Journal of Environmental Health Sciences
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• v.14 no.2
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• pp.1-12
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• 1988

Airborne dust and asbestos fiber concentrations were determined in subway stations located in Seoul area. Two stations, such as Eulchiro 4-Ka Station of Line #2, constructed during a period of 1980-1984 and Hyehwa Station of Line #4, opened in 1985, were selected. The results of the study are as follows. 1. Daily time-weighted average (TWA) concentrations of airborne dusts from 07:00 to 20:00 hours in Line #2 and Line #4 were 0.43$\pm$0.08 mg/m$^3$ and 0.37$\pm$0.12 mg/m$^3$, respectively. Thus, the dust levels in Line #2 were significantly higher than the levels in Line #4 (p < 0.05). 2. Dust levels in the morning (07:00-11:00 hours), noon (11:00-16:00 hours) and in the evening (16:00-20:00 hours) in Line #2 were 0.47$\pm$0.17 mg/m$^3$, 0.37$\pm$0.08 mg/m$^3$, and 0.46$\pm$0.07 mg/m$^3$ respectively. Thus, dust levels in the morning and evening (i.e., during rush hours) were significantly higher than levels in the noon (p < 0.02). However, there was no such difference in dust levels by time in Line #4. 3. Airborne total dust concentrations were well below the occupational health standard of 10 mg/m$^3$, however, the levels were exceeding the ambient air standard recommended by the Korean Environment Administration. 4. All of airborne asbestos fiber concentrations were equal to or below 0.005 fibers/cc. The levels are within both occupational health standards and U.S. EPA criteria. 5. A consideration should be given to the improvements of cleaning methods (such as use of vacuum cleaning instead of brushing) and the existing ventilation (such as more air change and filtration of supply air) for a reduction of dust levels. 6. It is recommended that routine monitoring of airborne dusts and asbestos fibers be conducted because more dusts and asbestos fibers can be produced in the air due to the deterioration of facilities by age and water damage in future.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.2
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• pp.256-265
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• 2009

The purpose of this study is to check color change, color fastness, increase wt., antibiosis, and UV-protection efficiency depending on gallnut concentrations and mordanting methods, when silk fabrics dye with gromwell according to pH. This results will contribute in developing of natural mordant with multi function. The results are as follows. ${\lambda}_{max}$ of Gallnut extracts was near 299 nm. When gallnut was used as a mordant, at all pH levels, pre-mordanted fabrics had red color and post-mordanted ones had red-purple color which was closed to natural color of gromwell. Brightness of post-mordanted fabrics was higher than that of pre-mordanted fabrics. In the case of chroma, pre-mordanted fabrics was higher than post-mordanted fabrics. There was no significant difference of color, brightness, and chroma depending on gallnut concentration. As mordanting concentration increased, fabric weight gradually went up and increase weight reached maximum $17{\sim}19%$. At all pH levels, color fastness improved by pre-mordanting and post-mordanting, and it showed the maximum $4{\sim}5$ grade of wet fastness and 5 grade of dry cleaning. Antibiosis of silk fabric was improved by gromwell dyeing and synthetic tannin mordanting. Antibiosis of gallnut extracts was excellent. The color fastness and antibiosis were preserved after 10 cycle dry cleaning. UV-protection efficiency was excellent by dyeing with gromwell and mordanting with gallnut.

• Journal of Biosystems Engineering
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• v.40 no.1
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• pp.10-18
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• 2015

Purpose: The study was conducted to investigate the proper working conditions like the mesh size of the concave and the chaffer angle of the oscillating sieve, and the fan speed of the head-feeding rice combine for foxtail millet harvesting. Methods: The study aimed to determine the harvesting conditions for the rice combine harvester at a 0.5 m/s working speed and at $40^{\circ}$ and $55^{\circ}$ sieve chaffer angles. The harvesting loss of the foxtail millet based on the speed of the fan and the oscillating speed of the sieve was measured at three levels of fan speed and oscillating sieve speed. Results: The threshing rates of different foxtail millet varieties were 64.1~83.5% at a mesh size of 7 mm of the concave. In experimental foxtail millet harvesting, the optimal operating condition of the rice combine harvester included a $40^{\circ}$ sieve chaffer angle and a 4.8 Hz oscillating sieve (cleaning shoe) frequency. The grain loss was found to be lower at a $40^{\circ}$ than at a $55^{\circ}$ sieve chaffer angle. In field harvesting using the combine harvester, the lowest harvesting grain loss rate of the foxtail millet varieties ranged between 0.2~0.5% at a 7 mm mesh concave, $40^{\circ}$ chaffer angle, 4.8 Hz sieve frequency, and a 20 m/s fan speed at an engine speed of 2,000 revolutions per minute (RPM). Conclusions: Findings showed that foxtail millet could be harvested using the combine harvester.

• Fashion & Textile Research Journal
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• v.15 no.5
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• pp.825-833
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• 2013

In this study, the dyeing properties of Phellodendron amurense on cotton and silk fabrics were evaluated to establish a scientific database of dyeing methods using natural dyes with the ultimate aim of facilitating the practical use of these dyes. The optimal thickener and dyeing concentrations depending on the thickener type were identified when dyeing with P. amurense, and the fabric color, color fastness, and antibiosis were examined for various thickeners, fabrics, and mordants. The results were as follows.: The optimal concentrations of thickeners when dyeing on cotton and silk fabrics were CMC 3% (w/w), Mayprogum 7% (w/w), and Indalka 9% (w/w). The optimal concentration of P. amurense was 25% (w/w), irrespective of the type of thickener. To maintain the hue unique to P. amurense, thickening with Mayprogum or Indalka and mordanting with Al was effective for cotton, while thickening with Mayprogum or Indalka and mordanting with Al or thickening with CMC and mordanting with gallnut was effective for silk. The dry-cleaning fastness and abrasion resistance of cotton fabrics dyed with P. amurense were excellent at the 4-5 level. Gallnut was effective for washing fastness and perspiration fastness against color degradation, and FFC was effective for light fastness. The washing fastness, dry-cleaning fastness, abrasion resistance, and perspiration fastness of silk fabrics dyed with P. amurense were excellent at level 4, except for washing and perspiration fastness, and FFC was effective for the improvement of light fastness. Dyeing cotton and silk fabrics with P. amurense thus yielded antibiosis and excellent washing fastness.

• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.123-131
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• 2014

Whole amount of waste water, approximately 921.6 liter, for cleaning a ready mixed concrete truck should be used to produce concrete as a mixing water or cleaning water. Recycling water for concrete mixing contains solids, which cause decrease in slump, air and compressive strengths, so it may influence on poor concrete quality. Therefore, it has been maintained to use recycling water with less than 3 percent of solids. Since no evaluation system has been constructed to directly reflect on variability of recycling water from ready mixed concrete plants, it is necessary to develop "Automatic recycling solid measuring system" for quality controls in real time. In this research, sensors measuring waste water concentration in ultrasonic and inductance methods were developed, and automatic system using the sensors were established. The accuracy of measurement sensors developed for recycling water based on various conditions of concentration was proved, and application limits were evaluated. Also, concentration of recycling water using sensors developed from ready mixed concrete plant was measured, and curing method verified the accuracy of the sensors. Moreover, measurement sensors for recycling water in various locations were installed to evaluate the effects on measuring method and spots. The automatic measuring system for recycling water concentration, which is developed in the research, will contribute to improve concrete quality safety through reliable solids maintenance.

• Journal of Surface Science and Engineering
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• v.34 no.1
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• pp.62-67
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• 2001

Green technology is being developed up to a point that is feasible not only in an environmental sense, but also in an economical viewpoint. This paper introduces two case studies that applied $CO_2$ technology into nuclear industry. 1) Nuclear laundry : A laundry machine that uses liquid and supercritical $CO_2$ as a solvent for decontamination of contaminated working dresses in nuclear power plants was developed. The machine consists of a 16 liter reactor, a recovery system with compressors, and storage tanks. All $CO_2$ used in cleaning is fully recovered and reused in next cleaning, resulting in no production of secondary nuclear waste. Decontamination factor is still lower than that in the methods currently used in the plant. Nuclear laundry using $CO_2$ looks promising with technical improvements-surfactants and mechanical agitation. 2) $CO_2$ nozzle decontamination : An adjustable nozzle for controlling the size of dry ice snow was developed. Using the developed nozzle, a surface decontamination device was made. Human oils like fingerprints on glass were easy to remove. Decontamination ability was tested using a contaminated pump-housing surface. About 40 to 80% of radioactivity was removed. This device is effective in surface-decontamination of any electrical devices like detector, controllers which cannot be cleaned in aqueous solution.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.11-15
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• 2013

In order to find a sanitary logistic way to handle library books, papers and environmental sources contacting the books were tested in their microbial contamination load and methods to decontaminate the books were investigated. Generally bacterial load of inner book pages was very low, but increased when contaminated with liquid such as saliva. In contrast, their lateral ends showed much higher bacterial contamination presumably due to dry dust contamination on there. As operations to improve the sanitary book conditions, turbulent air blow was found to be workable for reducing dry dusty contamination and 280 nm ultra-violet (UV) light emitting diode (LED) was so for decontaminating wet surface contamination. Microbial inactivation by the UV LED could be realized with irradiation for more than 5 minutes at 2 cm distance. Air blow of 5.5 m/s for 0.5~1 minute could reduce the dusty contamination on a model book surface.