• Journal of the Korean institute of surface engineering
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• v.37 no.6
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• pp.344-349
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• 2004

Emulsions were formed through putting small quantity of nickel electroplating solution into supercritical carbon dioxide, and then electroplating in the $sc-CO_2$ emulsions was conducted. It is an environmental-friendly technology that can solve the treatment of a large quantity of toxic plating wastewater, which is a big problem in the existing wet plating, and also can reduce secondary waste generation fundamentally. Supercritical carbon dioxide emulsions enhanced by ultrasonic horn were formed by non-ionic surfactant and nickel solution. Plating condition within emulsions was set up as 120bar and $55^{\circ}C$ through measurement of electrical conductivity following the pressure change. Experiments were conducted respectively against supercritical carbon dioxide emulsions electroplating and general chemical electroplating, and then their results were compared and analyzed. As the experiment result utilizing emulsions, plating surface was formed very evenly even with a small quantity of electroplating solution, and fine particles were plated compactly without any pinhole or crack due to hydrogenation, which occurs in general electroplating. Used electroplating solution can be reused through recovery process. Therefore, this technology will be able to be applied as new clean technology in electro-plating.

• Journal of the Korea Institute of Building Construction
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• v.11 no.5
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• pp.452-458
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• 2011

Bamboo is representing environmentally friendly building finishing materials as proven in the former researches. The purpose of this study is to evaluate the application properties of cementitious materials modified with bamboo charcoal as building finish materials. Flow test in fresh condition was conducted to assess the workability. Compressive and bending strength were measured after harding. As the thermal properties, thermal conductivity and density were measured. The properties were surpassing over them in case of using the pine charcoal in every tests. The thermal conductivity of them increased with the modified ratio. After the modified ratio 50%, the thermal conductivity decreased. Insolation and absorption performance is due to the lower density by modification of bamboo charcoal.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.323-327
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• 2000

Microwave-assisted process (2,450MHz), which is known as a more environmental-friendly process with economic advantages than the current extraction methods, was investigated to pre-establish the extraction conditions for soluble ginseng components used for the processing of ginseng products. The extractions of soluble ginseng components showed optimum conditions, such as 60 mesh in particle size, 1 : 10 (g/mL) in the sample to solvent ratio, and less than 100 watts in energy efficiency. Under these conditions using along with 60% ethanol for 5 min, the overall yield of ginseng extracts was about 83%. Most soluble components including saponins were extracted by repeating five times of microwave-assisted extraction.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.6
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• pp.558-563
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• 2020

Hydrogen is attracting attention as an alternative energy source as an eco-friendly fuel without emitting environmental pollutants. In order to use hydrogen as an energy source, technologies such as hydrogen production and storage must be used, and new storage methods are being studied. In this study, the behavior of hydrogen in the storage tank were numerically studied under high-pressure hydrogen discharge conditions in a Type III hydrogen tank. Numerical results were compared with the experimental value and the results were quantitatively analyzed to verify the numerical implementation. With the results of pressure and temperature values under a given discharge condition, the Redich-Kwong gas model showed the adequate models with the smallest error between numerical and experimental results.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.483-488
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• 2021

With continuous emission of environmental pollutants and an increase in greenhouse gases such as carbon dioxide, demand to seek other types of energy sources, alternative energy, was needed. Hydrogen, an eco-friendly energy, is attracting attention as the ultimate alternative energy medium. Hydrogen storage technology has been studied diversely to utilize hydrogen energy. In this study, the gas behavior of hydrogen in the storage tank was numerically examined under charge conditions for the Tpe III hydrogen tank. Numerical results were compared with the experimental results to verify the numerical implementation. In the results of pressure and temperature values under charge condition, the Realizable k-ε model and Reynold stress model were quantitatively matched with the smallest error between numerical and experimental results.

• Research in Plant Disease
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• v.17 no.2
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• pp.148-154
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• 2011

This study was conducted to control the seed borne pathogens (Alternaria spp.) of carrot and to examine the seed germination rate by using 13 environment friendly agricultural materials instead of conventional chemicals for organic cultivation. The growth inhibiting effects on pathogens showed the different responses according to each agricultural material and effective 7 materials against seed borne pathogens were selected. Among 7 materials, the carrot seeds sterilized with plant extracts, Tanger Stop and Land Saver were not germinated at all. The germination rate of seeds sterilized with other materials showed the similar levels with reference chemical (Benlate-T) and non-treated seeds. Infection rates of seeds sterilized with seaweed extract, Bellopper for controlling A. radicina and plant extract, Ssial-100 for A. dauci were similar or low infection rate compared with reference chemical. The germination rate and root length of seeds sterilized with Bellopper and Ssial-100 was similar or superior to those of chemical sterilized seeds. The optimal condition seemed to be a little bit different depending on the concentration of materials. As a result, the sterilization of carrot seeds by using the environment friendly materials could be effectively utilized as a technology to inhibit the infection of seed-borne pathogens.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.61-67
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• 2009

A non-discharged system of sequentially physico-chemical water treatment was used to treat the contaminated water produced from washing system of soils according to full-scale soil washing. After washing the TPH contaminated soils, the remaining concentrations of COD$_{Mn}$, SS, and n-hexane were analyzed for each compartment to estimate the treatment efficiencies of non-discharged system. Three times of sampling events were conducted for 4 different compartments (sediment tank, flocculation tank, oil/water separator, and process-water tank). In addition, soil washing efficiencies and concentrations of each parameter (COD$_{Mn}$, SS, and n-hexane) for process-water tank were analyzed for about 8 months. As results, the average efficiency of soil washing was high to have 95.9%, regardless of the condition of TPH contamination level for soils, as well as the concentrations of COD$_{Mn}$, SS, and n-hexane in the process-water tank were below the regulation limits of the Water Environmental Conserveation Act. Accordingly, the full-scale washing treatment system in this study could make the washing water 100% recycled which lead the system to be environmentally-friendly and economical.

• Journal of Korean Academy of Nursing
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• v.25 no.4
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• pp.641-652
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• 1995

Working as nurses, authors found that some patients were not content with their hospital life. Some patients wanted to move to another ward, and others complained about their ward atmosphere. In spite of patients' discomfort, nurses didn't know what made some patients complain about their ward. So, authors tried to find factors that influence atmosphere of hospital wards of the neurosurgery patients. To know the atmosphere of wards, authors selected five neurosurgery ward of a university hospital in Seoul. Observation took a month. An author observed using molar approach, in the morning, in the day time, and in evening time. Authors used concealment /no intervention technique. An author checked condition of people in the wards, and observed their verbal and nonverbal communication behavior their activities and environmental characteristics, and interpreted their meaning through ethnographic research methodology by Spradly. Authors found there was an important factors that influence the atmosphere of ward. It was a human and his attitude. At least one person who was willing to help others made ward atmosphere better. Helping others physically whenever needed, sup-porting the depressed emotionally, offering foods, or talking to others friendly brought good atmosphere. On the contrary, if everyone was indiffernt to others, the atmosphere became cold. Self-centered or selfish behaviors such as occupying too much area, using the toilet too long, covering other's suction bottle without permission and seeing others delicate or urinate were hurtful. In addition to the attitude of patients and their families, unkindness of medical teams including nurses and doctors and tasteless meal caused bad ward atmosphere. Based on this research finding, authors suggest the followings. A For the better atmosphere of ward 1. Nurses should try to make the ward atmosphere better by introducing new patient to older ones. 2. Every ward should have dividing curtains to keep patient's privacy. 3. All hospital personnel should be kind enough to make patients feel that they are repected. 4. Hospital should serve high quality meals to patients. 5. Patients had better stay with those in the similar condition. B. For the future studies 1. Repeated researches are necessary to check reliability of this results. 2. Researches for patients in different area such as ICU, or hemodialysis unit are necessary.

• Geomechanics and Engineering
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• v.12 no.5
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• pp.831-847
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• 2017

Conventional geotechnical engineering soil binders such as ordinary cement or lime have environmental issues in terms of sustainable development. Thus, environmentally friendly materials have attracted considerable interest in modern geotechnical engineering. Microbial biopolymers are being actively developed in order to improve geotechnical engineering properties such as aggregate stability, strength, and hydraulic conductivity of various soil types. This study evaluates the geotechnical engineering shear behavior of sand treated with xanthan gum biopolymer through laboratory direct shear testing. Xanthan gum-sand mixtures with various xanthan gum content (percent to the mass of sand) and gel phases (initial, dried, and re-submerged) were considered. Xanthan gum content of 1.0% sufficiently improves the inter-particle cohesion of cohesionless sands 3.8 times and more (up to 14 times for dried state) than in the untreated (natural) condition, regardless of the xanthan gum gel condition. In general, the strength of xanthan gum-treated sand shows dependency with the rheology and phase of xanthan gum gels in inter-granular pores, which decreases in order as dried (biofilm state), initial (uniform hydrogel), and re-submerged (swollen hydrogel after drying) states. As xanthan gum hydrogels are pseudo-plastic, both inter-particle friction angle and cohesion of xanthan gum-treated sand decrease with water adsorbed swelling at large strain levels. However, for 2% xanthan gum-treated sands, the re-submerged state shows a higher strength than the initial state due to the gradual and non-uniform swelling behavior of highly concentrated biofilms.

• Journal of Ocean Engineering and Technology
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• v.36 no.5
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• pp.326-339
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• 2022

Recently, not only Korea but also the world has been suffering from problems related to coastal erosion. The hard defense method has been primarily used as a countermeasure against erosion. However, this method is expensive and has environmental implications. Hence, interest in other alternative methods, such as the eco-friendly vegetation method, is increasing. In this study, we aim to analyze the hydraulic characteristic of submerged rigid vegetation according to the cross-sectional change through a hydraulic experiment and numerical simulation. From the hydraulic experiment, the reflection coefficient, transmission coefficient, and energy dissipation coefficient were analyzed according to the density, width, and multi-row arrangement of the vegetation zone. From numerical simulations, the flow field, vorticity distribution, turbulence distribution, and wave distribution around the vegetation zone were analyzed according to the crest depth, width, density, and multi-row arrangement distance of the vegetation zone. The hydraulic experiment results suggest that the transmission coefficient decreased as the density and width of the vegetation zone increased, and the multi-row arrangement condition did not affect the hydraulic characteristics significantly. Moreover, the numerical simulations showed that as the crest depth decreased, the width and density of vegetation increased along with vorticity and turbulence intensity, resulting in increased wave height attenuation performance. Additionally, there was no significant difference in vorticity, turbulence intensity, and wave height attenuation performance based on the multi-row arrangement distance. Overall, in the case of submerged rigid vegetation, the wave energy attenuation performance increased as the density and width of the vegetation zone increased and crest depth decreased. However, the multi-row arrangement condition did not affect the wave energy attenuation performance significantly.