• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.107.2-119
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• 1992

Fish pathology is one of the main scientific bases upon which this expansion in aquaculture has been dependent and requires a wide knowledge of the environmental constraints, the physiology and characteristic of the various pathogens, the responses of the host, and the methods by which they may be controlled. The primary disease and parasite problems in aquaculture animals related to viral, bacteria, fungal and protozoan epizootics. Parasitic nematodes, trematodes and cestodes are commonly found in aquaculture animals, but seldom are they present in concentrations sufficient to cause significant problems, When an epizootic does occur and chemical treatment is indicated, the appropriate chemical must be selected an properly applied. We have antibiotics, sulfa, nitrofuran and other chemicals for treatment of fish diseases, Some may be mixed with the feed during formulation, added to the pellets of feed as a surface coating, given in the form of an injection or used as a bath. Even though a drug or chemical has been officially approved for use in aquaculture, the substance should never be used unless there is a clear need, Some of the reasions for this view are as follows: (1) the constant use of antibiotics can leak to the development of resistant strains of bacteria, (2) biofilter efficiency may be impaired or destroyed by chemicals added to closed recirculating water systems, and(3) the injudicious use of chemical can have a damaging effect on the environment as well as on human.

• Journal of Magnetics
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• v.15 no.3
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• pp.123-127
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• 2010

The use of a cooling fan in an induction cooker raises a reliability issue due to the attraction of dust causing a malfunction of the cooling fan and also increases the noise level and power consumption of the device. The purpose of this study is to attempt to solve these problems by molding the Cu coil of an induction cooker with polymer composites that have a low electrical conductivity but a high thermal conductivity. Among the several polymer composites tested in this study, an aluminum nitride-based composite showed the best performance. The results show that the new induction cooker with the molded composite can operate for an extended period of time without the use of a cooling fan. A further advantage of this new type of induction cooker is that the temperature of the substance in the cooking pot increases more rapidly, indicating an increased efficiency of the induction cooker.

• Journal of Korean Academy of Nursing
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• v.40 no.6
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• pp.820-830
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• 2010

Purpose: The purpose was to develop a preliminary scale to measure Korean adolescents' health behaviors through a qualitative approach, to evaluate the scale psychometrically, and to develop a final scale. Methods: Participants were 61 adolescents for qualitative interviews and 1,687 adolescents for the psychometric evaluation. Procedure included content analysis of interviews to identify health behavior categories for Korean adolescents, pre-test to confirm that preliminary scale items were understandable, content validity by an expert panel, development of the web-based computer-assisted survey (CAS), and psychometric analysis to determine reliability and validity of the final scale. Results: A final scale was developed for both paper-and-pencil and CAS. It consisted of 14 health behaviors (72 items), including stress and mental health (10), sleep habits (5), dietary habits (12), weight control (4), physical activity (4), hygiene habits (5), tobacco use (5), substance use (2), alcohol consumption (4), safety (4), sexual behavior (9), computer use (3), health screening (4), and posture (1). Conclusion: The scale's strong points are: 1) Two thirds of the final scale items are Likert scale items, enabling calculation of a health behavior score. 2) The scale is appropriate to Korean culture. 3) The scale focuses on concrete health behaviors, not abstract concepts.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.757-763
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• 2023

Major industrial accidents in which workers die due to fires or explosions while working at chemical substance handling workplaces continue to occur. Among the major industrial accidents that occurred between 2005 and 2021, the accident status by work situation and equipment was analyzed. Through analysis, it was confirmed that storage, reaction, and piping facilities were the main causes of the accident, and a self-checklist for each facility was developed. Verification was conducted through the supply and use groups to evaluate the suitability of the use, duties, and items of the self-checklist. The user group showed higher satisfaction than the supplier group for all three suitability of use, job, and item. In particular, since the inspection items of the self-checklist were organized around the cause of the accident derived through the analysis of actual accident cases, the satisfaction level was high in all groups. It is expected that the self-checklist developed through this study will be useful not only for large companies but also for small and medium-sized chemical industries that lack professional manpower.

• Journal of the Korean Society of School Health
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• v.29 no.3
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• pp.299-309
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• 2016

Purpose: The purpose of this study was to investigate the association between sexual intercourse and experience of alcohol, tobacco, and drugs use among adolescents in South Korea. Methods: This study used the data of the Korea Youth Risk Behavior Web-based Survey from 2010 through 2014. The subjects of this study were 367,562 students (Male 187,610, Female 179,952). The subjects' general characteristics and their sexual experiences according to their general characteristics were analyzed using frequency analysis. The relationship between sexual intercourse and the use of alcohol, tobacco, and drugs was analyzed through multiple logistic regression. The analyses were conducted using SPSS 18.0. Results: According to the study, the significant predictors of sexual intercourse were gender, grade, parents' educational level, residence type, economic status, and substance abuse. Adolescents who had used alcohol, tobacco, and drugs were more likely to have had sexual intercourse than their peers who hadn't use the substances. Conclusion: The results suggest that factors that increase the risk of having premature sex should be managed and prevented systematically. Among the factors, in particular, drinking, smoking, and drug use require intensive management.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.762-768
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• 2004

Chromium has been known to be involved in the glucose metabolism, and hence the utilization of cellular glucose is impaired in the chromium deficiency. Chromium has been recognized as an essential nutrient since the finding of low-molecular-weight Cr-binding substance (LMWCr) as a biological modifier of insulin action. Clinical chromium deficiency associated with glucose intolerance that respond to the administration of chromium. The major impediment to the use of orally administered chromium is poor absorption of trivalent chromium in its inorganic form. Trivalent chromium is more available in yeast md, more recently, as chromium picolinate for oral absorption. The widespread use of these supplements has resulted in controversy regarding chromium's role as a nutrient, its use for treatment of insulin resistance, and its potential toxicity. Most recent evidence strongly supports tile conclusion that there is little fear of toxic reactions from chromium consumption. This report reviews the evidence for the potential toxicity of chromium supplements in contrast with its usefulness as a nutrient or therapeutic agent in the treatment or prevention of insulin resistance.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.323-329
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• 2000

The coupling of an activated sludge reactor with a membrane unit, i.e., Membrane Coupled Activated Sludge (MCAS) system offers several advantages over conventional process. But the major hurdle in the extensive use of this process is the continuous reduction of permeation flux caused by membrane fouling. The aim of this study is to investigate membrane fouling characteristics in the MCAS process. During crossflow ultrafiltration(CFUF) of activated sludge, floc size decreased abruptly at the beginning of operation and thereafter decreased continuously and gradually. The floc size changed from 100~200 to $6{\sim}8{\mu}m$ depending on recirculation velocity. This floc breakage played a key role in rapid increase of $R_c$(cake layer resistance), which led to flux decline. The floc breakage stimulated biomass to release EPS(Extracellular Polymeric Substance) which has been known to be one of the major membrane foul-ants. The amounts of EPS before and after CFUF were 266 and 405(VS mg/MLSS g), respectively. The rise up of EPS concentration was another factor affecting flux decline in MCAS system.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.446-464
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• 2015

Objectives: This study was conducted to evaluate the task-specific hazards of chemicals used by nail technicians in Daegu Metropolitan City. Materials: A total of 30 nail shops located in Daegu City were surveyed to investigate the major tasks and practices performed by nail technicians and the ingredients listed in nail care products used in shops. We also collected instructions for use and material safety data sheets(MSDSs) of nail care products and compared CAS Nos. of ingredients with the lists of chemicals regulated by the Industrial Safety and Health Act(ISHA) and Chemical Substances Control Act(CSCA). Results: A total of 125 chemical ingredients were found in 468 nail care products used at the 30 nail shops. The most frequently found ingredients were ethyl acetate(72%), followed by n-butyl acetate(71.8%), isopropanol(56%), benzophenone(51.1%), nitrocellulose(46.4%) and ethanol(45.3%). Comparing six tasks, the task of manicuring used the most products at 222 products containing 91 ingredients. Among the 125 ingredients, there are 31 chemicals with occupational exposure limits(OEL) designated by the Ministry of Employment and Labor(MoEL), eight categorized as carcinogens, one mutagen and two reproductive toxic chemicals. In terms of carcinogens, formaldehyde was identified as the only confirmed human carcinogen(1A). We found that there was one chemical with a permissible limit, one special management substance, 18 workplace monitoring substances and ten special health diagnosis substances regulated by ISHA. For CSCA, nine poisonous substances, six substances requiring preparation for accidents and one restricted substance were identified. Conclusions: Based on these findings, formaldehyde was identified as one of the chemicals that should most strictly be controlled for the protection of the health of nail technicians and customers. At the same time, it is necessary to distribute materials with detailed hazardous information of nail care products for nail shop technicians.

• Journal of Nutrition and Health
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• v.37 no.9
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• pp.809-816
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• 2004

The purpose of this study was to evaluate the effect of maternal nutritional status and health behaviors on the concentrations of minerals (Zn, Fe, Ca) and the immunological substances (lactoferrin, sIgA, Iysozyme) in breast milk. Breast milk was collected from 193 healthy Korean women from obstetric clinics and postpartum care centers in Seoul. : 99 colostrum (1 - 5 days postpartum), 33 transitional milk (6 - 10 days postpartum), 61 mature milk (11 - 50 days postpartum). The concentrations of minerals and immunological substance were highest in colostrum and decreased with lactational period. Concentrations of Zn and Fe reduced significantly from colostrum to mature milk, however, Ca concentration stayed constant throughout the lactational period. Contents of lactoferrin, sIgA, and lysozyme were significantly lower in mature milk than in colostrum. Mother's nutritional status, assessed by prepregnancy BMI, had an effect only on colostrum, but not on transition and mature milk. Fe concentration of colostrum was significantly lower in underweight (prepregnancy BMI < 18.5) than in overweight mothers (prepregnancy BMI $\geq$ 23.0). Also lower tendency was observed for sIgA and lysozyme contents, even though the difference was not statistically significant. Pregnancy weight gain had no effect on the breast milk component. Since nutritional factors had some effect on colostrum, the health behaviors of mothers providing colostrum were assessed. The mother's behavior of smoking, drinking, morning sickness, parity, disease, nutrient supplement use had no significant effect on the breast milk component, however, Zn, sIgA, and lysozyme were the somewhat affected components by maternal health behavior.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.126-126
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• 2001

The Rhus verniciflua contains alkly(en)-catechol type allergens with a saiurated or unsaturated alkly chain of 15 or 17 carbon atoms. It has been recognized as an extremely active allergen causing skin reactions similar In poison ivy. The allergic contact dermatitis induced by the urushiol is known to be mediated be T lymphocytes whicht specifically recognize the hepten urushiol. Therefore. direct use of this plant as a medicinal purpose might imply a considerable hazard in Korea. In this study, using the established method for the detoxification from the stem bark of Rhus verniciflua, an strong antioxidant substance was isolated and characterized DPPH (diphenypricryl hydrazyl) assay measures hydrogen atom-donating activity and hence provides a measure of free radical scavenging antioxidant activity. DPPH, a purple-colored stable free radical, is reduced to yellow-colored diphenylpicryl hydrazine by antioxidants to deducing agents. Antioxidative effects of the water extract from RV were measured by DPPH assay. Twenty microliters of the extract was added to 1ml of 100mM DPPH solution in ethanol The mixture was shaken and left to stand for 10min at room temperature. The crude water extracts was purified by using HPLC method with a DEAE (anionic type), CN, ODS column. The purified compound remained stable at pH 3.0-6,0, but unstable above pH 6.5. It was stable heat at 10$0^{\circ}C$ for 4 hours, but still had about 80% of residual activity after treatment at 10$0^{\circ}C$ for 5 hours. The elemental composition of the HR-EI mass spectrum at m/z 170.02 was estimated the empirical formula as $C_{7}$ $H_{6}$ $O_{5}$. $C_{10}$ $H_4$ $O_2$N$_1$, $C_{5}$ $H_4$ $O_4$N$_3$, $C_{8}$$H_2O$$_1$N$_4$. In antimicrobial test, no inhibition was observed against Gram-positive and negative bacteria. This compound was stronger than that of commercial antioxidant by DPPH test, such as BHT, BHC at the same concentration (20$\mu$g/ml).ml).