• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.628-634
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• 2006

This study was performed to investigate the quality of pre-processed vegetables used in school and institutional food-services. Pre-processed food materials (carrot, potato, and cabbage) frequently used in food-service were collected from 14 various processing company sources. The sensory and physico-chemical qualities of the pre-processed food materials were determined using sensory and instrumental analysis. For the physico-chemical analysis of the food materials, pH, total acidity, hardness, Hunter colorimeter value, reducing sugar and vitamin C content were determined. For the sensory quality evaluation, 15 panelist were trained and consensus was reached on the quality standards of the preprocessed materials (carrot, potato, and cabbage). Finally, appearance, color, texture, off-odor/taste, and overall quality were determined. In the physico-chemical analysis, there were no significant differences among samples collected from various processing companies. In sensory quality evaluations, the color quality of pre-processed potato was lower than that of other materials. From the coefficient correlations and partial least squares regression analysis between sensory and instrumental data, pH, total acidity, colorimeter values, and hardness were considered important components in assessing the quality of pre-processed vegetables.

• Resources Recycling
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• v.25 no.1
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• pp.48-59
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• 2016

The earth has been warming due to $CO_2$ gas emissions from fossil fuel cars and a ship. So the hydrogen fuel cell vehicle(FCV) using hydrogen as a fossil fuel alternative energy is in the spotlight. Hyundai Motor Company of Korea and a car companies of the US, Japan, Germany is developing a FCV a competitive. Obtained hydrogen as a by-product of the coke plant, oil refineries, chemical plants of steel mill, coal is reacted with steam at high temperatures, methane gas, manufacture of high purity hydrogen Methane Steam Reforming and hydrogen detachable reforming method using the Pressure Swing Adsorption or Membrane Reforming technical or decomposition of water to produce electricity. Hydrogen is the electronic industry, metal and chemical industries, which are used as rocket fuel, etc. are used in factories, hospitals, home of the fuel Ene.Farm system or FCV. And a method of storing hydrogen is to store liquid hydrogen and a method for compressing normal hydrogen to the hydrogen container, by storing the latest hydride or Organic chemical hydride method is used to carry the hydrogen station. Korea is currently 13 hydrogen stations in place and in operation, plans to install a further 43 places.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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• pp.156-163
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• 2012

Objectives: The aim of the present study was undertaken to investigate the association between communication for chemical hazard information and characteristics of occupational safety and health managers. Subjects and Methods: We surveyed 78 occupational safety and health managers(64 male and 14 female) in 78 chemical manufacturing plants. Data were obtained using a self-reported questionnaire about size and type of company, products, communication system for chemicals and work-related characteristics of occupational safety and health managers. All analyses in this study were performed using SPSS program 12.0. Results: 64.1% of the study participants were occupational health managers aged 39.3 years on average and were graduated from college and university around 90%. 30.0% and of them were majoring in chemistry (engineering chemistry), 18.0% occupational health, 16% nursing and 30.0% others. Occupational safety managers were aged 39.4 years on average, 42.9% of them were majoring in chemistry (engineering chemistry), 21.4% environmental engineering, 10.7% occupational safety and 25% others. 86% of occupational health managers and 71.4% of occupational safety managers were classified as office job. Over 94% of the hazards information for chemicals were delivered by occupational safety and health managers, but about 28.2% workers preferred outside experts who have a profound knowledge about occupational safety and health and understandable. Occupational safety and health managers and workers had difficulties in understanding toxicological information, hazards identification, stability/reactivity, composition/information on ingredients, physical/chemical properties and ecological information. On multiple logistic regression analysis for the 16 heading of material safety data sheet, content of material safety data sheet was significantly associated with education level (odds ratio=0.286, 95% confidence interval=0.105-0.780). The hazard identification (odds ratio=3.947, 95% confidence interval=1.092-14.271) and toxicological information (odds ratio=0.841, 95% confidence interval=0.705-0.998) were significantly associated with type of occupation. Conclusions: This finding implies that the education level, type of occupation and speciality of occupational safety and health managers may affects hazards information delivery.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1817-1826
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• 2022

After the hydrogen fluoride leak in Gumi in 2012, the government has been systemizing the disaster management system, such as responding to and managing chemical accidents. In particular, the Ministry of the Interior and Safety (MOIS) is in charge of evacuation of residents following chemical accidents based on the Framework Act on Management of Disaster and Safety. In this study, an application plan was presented to support and utilize the decision-making support for evacuation of residents after a chemical accident using the chemical accident investigation equipment of the National Disaster Management Research Institute (NDMI). In the equipment operation system for scientific information collection due to chemical accidents, the roles and purpose of use of long/short distance measurement equipment were presented according to regular and emergency situations. Using the data acquired through long/short distance measurement equipment, it can be used as basic data for resident evacuation decision-making by monitoring whether chemicals are detected in an emergency and managing data on detected substances by company in a regular situation. As a result of measuring chemical substances in order to verify on-site usability by equipment only for the regular operation system, it was confirmed that real-time detection of chemical substances is possible with long distance measuring equipment. In addition, it was confirmed that it was necessary to check the measurable distance and range of the equipment in the future. In the case of short distance measurement equipment, hydrocarbon-based substances were mainly detected, and it was confirmed that it was measured at a higher level in Ulsan-Mipo National Industrial Complex than in Onsan National Industrial Complex. It is expected that it can be used as basic data to support decision-making in the event of chemical accidents through continuous data construction in the future.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.145-145
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• 1997

Recent progress of electric technology requires new piezoelectric crystals having superior properties such as zero temperature coefficients and large electromechanical coupling factors. We have developed a series of new leading chandidates, La$_3$Ga5SiO14(langasite, LGS), La3Nb0.5Ga5.5O14(LNG), La3Ta0.5O14(LTG), to satisfy those requirements. High quality LGS, LNG and LTG single crystals, with dimensions of 2 inches in diameter, were successfully grown by the Czochralski method at a pulling rate of 1mm/h. Since no variation of chemical composition was observed when whole melt in a crucible was crystallized, congruency of these compositions was confirmed. Physical constants such as elastic constants, dielectric constants and piezoelectric constants were measured. Filters and oscillators made of grown LGS, LNG and LTG single crystals showed superior properties such as three times wider passband than that of quartz, low insertion loss and easy processing, Langasite family crystals were shown to be superior materials to other known materials such as quartz, LiTaO$_3$, $\alpha$-AlPO$_4$ and Li$_2$B$_4$O7.

• Journal of Korean Academy of Nursing
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• v.39 no.4
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• pp.549-561
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• 2009

Purpose: Work-related stress and risk factors among Korean employees were identified in this study. Methods: Data were obtained from employees aged 20 to 64 using the Korean Working Conditions Survey 2006 (KWCS). Multiple logistic regression analysis using SAS version 9.1 was performed to examine risk factors of work-related stress by gender. Results: The age-adjusted prevalence of work-related stress among male and female employees was 18.4% and 15.1% respectively. After adjustments for multiple variables among both male and female employees, there was a significant relationship between work-related stress and risk factors including education, company size, work time, ergonomic risks, biological chemical risks, and job demands. The significant variables for male employees were housework load, occupational class, and shift work, and for female employees, type of employment. Conclusion: There is a need to develop and support intensive stress management programs nationally giving consideration to work-related stress associated with working time, physical working environment, and job demands. Based on gender specific approaches, for male employes, stress management programs should be developed with consideration being given to occupational class and shift work. For stress management programs for female employees, consideration needs to be given to permanent employment status, specifically those in small companies.

• Journal of Environmental Science International
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• v.14 no.11
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• pp.1027-1033
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• 2005

The treatment of styrene vapor was carried out using the biofilter packed with loess/polyurethane composite during continuous operation of 74 days. The microorganisms were adapted within 2-3 days under the experimental conditions of inlet concentration and empty bed contact time (EBCT). At 200 sec of EBCT, the removal efficiency of styrene was 100\% with 200 ppmv of inlet concentration, while $92\%$ with 400 ppmv of inlet concentration. The biofilter showed the stable removal efficiencies of over $74\%$ under the EBCT range from 300 to 75 sec at the 150 ppmv of inlet styrene concentration. The maximum capacity of styrene removal for the biofilter packed with loess/polyurethane was $29g/m^3/hr$. During continuous operation of 74 days, pH of the drain water changed slightly and the pressure drop through the biofilter column was below $45\;mmH_2O/m$.

• Journal of the Korean Society of Combustion
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• v.13 no.2
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• pp.33-41
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• 2008

The high permeability of the gas in the molten iron of the dripping zone of the blast furnace is a major factor in achieving the stable operation of a furnace with high productivity. Basic studies of the liquid flow behavior in a packed bed are necessary to grasp the effect of various operational changes on conditions in the dropping zone. Molten iron and slag together playa critical role in the lower zone, transporting mass and energy, while impairing and redistributing the gas flow. In turn, molten iron and slag undergo physical and chemical changes, and are redistributed radially as they descend to the hearth. In this research, mathematical formulations are derived for the gas and the liquid. The solid phase is fixed with constant porosity. The information for the molten iron and slag includes the hold-up, velocity, pressure, and information related to the areas of interaction between the gas and the liquid, and the solid and the liquid. Predictable results include the velocity, pressure and temperature distribution. Additional parameters include the packed particle size and the air blast rate.

• Biomolecules & Therapeutics
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• v.2 no.3
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• pp.236-243
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• 1994

A splenocyte culture system supplemented with liver microsomes was developed to detect immunotoxic chemicals which require metabolic activation using cyclophosphamide as a positive standard. When liver microsomes were added to splenocyte cultures isolated from female B6C3Fl mice, the proliferation of splenocytes by lipopolysaccharide (LPS) was increased and the proliferation by concanavalin A (Con A) was decreased. However, when compared with each corresponding control, cyclophophamide was successfully activated to metabolites capable of suppressing Iymphoproliferative responses. This suppression was clearly dependent upon the amounts of microsomes added and/or the concentration of cyclophosphamide exposed. In these cultures, the proliferation of splenocytes was suppressed when the cells were exposed to cyclophosphamide on the day of culture initiation. On the other hand, microsome was responsible for the increase in LPS mitogenicity and NADPH was responsible for the decrease in Con A mitogenicity. Finally, our present culture system was compared with the hepatocyte-splenocyte coculture system which we had developed earlier. We found that the hepatocyte-splenocyte coculture was better able to activate cyclophosphamide to metabolites capable of suppressing the antibody response to sheep erythrocytes. Although our present culture system was relatively poor to activate cyclophosphamide in cultures for antibody response, it will be useful as a simple screening method to detect suppression of certain in vitro immunotoxic parameters like LPS mitogenicity by chemicals which require metabolism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.3106-3111
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• 2010

In this study, a comparative study was performed between one- and two-stage refrigeration system to cool the natural gas temperature down to $-40^{\circ}C$ using propane as a chilling medium. As a thermodynamic model, Peng-Robinson equation of state equation was applied and PRO/II with PROVISION release 8.3 at Invensys company was utilized for the simulation of the refrigeration system. Through this study, optimization work showed that two-stage refrigeration system was proven to save about 33.5% refrigeration power consumption compared to the one-stage refrigeration cycle.