• Journal of Ecology and Environment
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• v.46 no.3
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• pp.161-171
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• 2022

Background: Epilobium hirsutum L. is designated as an endangered plant in South Korea located in Asia, due to the destruction of its habitats through the development of wetlands. Therefore, in this study, in order to find a light condition suitable for the growth and ecophysiological responses of Epilobium hirsutum L., those of this plant under treatment with various light qualities in a smart farm were measured. Results: In order to examine the changes in the physiological and growth responses of Epilobium hirsutum L. according to the light qualities, the treatment with light qualities of the smart farm was carried out using the red light: blue light irradiation time ratios of 1:1, 1:1/2, and 1:1/5 and a red light: blue light: white light irradiation time ratio of 1:1:1. As a result, the ecophysiological responses (difference between leaf temperature and atmospheric temperature, transpiration rate, net photosynthetic rate, intercellular CO₂ partial pressure, photosynthetic quantum efficiency) to light qualities appeared differently according to the treatments with light qualities. The increase in the blue light ratio increased the difference between the leaf temperature and the atmospheric temperature and the photosynthetic quantum efficiency and decreased the transpiration rate and the intercellular CO₂ partial pressure. On the other hand, the white light treatment increased the transpiration rate and intercellular CO₂ partial pressure and decreased the temperature difference between the leaf temperature and the ambient temperature and photosynthetic quantum efficiency. Conclusions: The light condition suitable for the propagation by the stolons, which are the propagules of Epilobium hirsutum L., in the smart farm, is red, blue and white mixed light with high net photosynthetic rates and low difference between leaf temperature and atmospheric temperature.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.34-37
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• 2017

In recent emerging industry, Display field becomes bigger and bigger, and also semiconductor technology becomes high density integration. In Flat Panel Display, there is an issue that electrostatic phenomenon results in fine dust adsorption as electrostatic capacity increases due to bigger size. Destruction of high integrated circuit and pattern deterioration occur in semiconductor and this causes the problem of weakening of thermal resistance. In order to solve this sort of electrostatic failure in this process, Soft X-ray ionizer is mainly used. Soft X-ray Ionizer does not only generate electrical noise and minute particle but also is efficient to remove electrostatic as it has a wide range of ionization. X-ray Generating efficiency has an effect on soft X-ray Ionizer affects neutralizing performance. There exist variable factors such as type of anode, thickness, tube voltage etc., and it takes a lot of time and financial resource to find optimal performance by manufacturing with actual X-ray tube source. MCNPX (Monte Carlo N-Particle Extended) is used for simulation to solve this kind of problem, and optimum efficiency of X-ray generation is anticipated. In this study, X-ray generation efficiency was measured according to target material thickness using MCNPX under the conditions that tube voltage is 5 keV, 10 keV, 15 keV and the target Material is Tungsten(W), Gold(Au), Silver(Ag). At the result, Gold(Au) shows optimum efficiency. In Tube voltage 5 keV, optimal target thickness is $0.05{\mu}m$ and Largest energy of Light flux appears $2.22{\times}10^8$ x-ray flux. In Tube voltage 10 keV, optimal target Thickness is $0.18{\mu}m$ and Largest energy of Light flux appears $1.97{\times}10^9$ x-ray flux. In Tube voltage 15 keV, optimal target Thickness is $0.29{\mu}m$ and Largest energy of Light flux appears $4.59{\times}10^9$ x-ray flux.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.27-34
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• 2023

Using ammonia as fuel for solid oxide fuel (SOFC) cells has become an attractive topic nowadays due to its high efficiency, environmental friendliness, and ease of storage and transportation. Several configurations of ammonia-fed SOFC systems have been proposed and investigated, demonstrating high electrical efficiency. However, to further enhance efficiency, it is crucial to understand the inefficient components of the system. The exergy concept is well-suited for this purpose, making exergetic analysis essential for ammonia-fed SOFC systems. This study conducts an exergetic analysis for three selected systems: a simple fuel cell system (FC), an anode off-gas recirculation system (RC-FC), and a recirculation system with water removal (RC-WR-FC). The results reveal that the exergetic efficiencies of the FC, RC-FC, and RC-WR-FC are 48.7%, 51.6%, and 58.4%, respectively. In all three systems, the SOFC stack is the main source of exergy destruction. However, other components with relatively low exergetic efficiency, such as the burner, air heat exchanger, and cooler/condenser, offer greater opportunities for improvement.

• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.29-38
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• 2010

Batch tests were carried out to examine the influence of the presence of soil and Fe(II) sorption capacity of soil on the ferrous catalyzed sodium persulfate oxidation for the destruction of organic pollutants in the application of in-situ chemical oxidation. Laboratory column tests were also conducted to investigate the transport of oxidant and catalyst in contaminated groundwater. Test results proved that Fe(II) was adsorbed on soil surface, and thus soil behaved as a heterogeneous catalyst, enhancing the naphthalene removal rate up to 50%. Column tests that were conducted with and without dissolved Fe(II) showed that naphthalene removal ratio were 24% and 25%, respectively. The removal efficiency was not enhanced with dissolved Fe(II), since the dissolved Fe(II) flew out of the column as the oxidant progressively injected into the column saturated with Fe(II). It indicates that the injected oxidant could not interact with dissolved Fe(II). But target organic pollutant was degraded in soil column system, implying that sulfate radical was produced by the reaction of dissolved persulfate with Fe(II) adsorbed on soil.

• Journal of the Korean Society of Costume
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• v.55 no.4 s.94
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• pp.79-94
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• 2005

The goal of this research, contorted from the perspective of media aesthetics, is to uncover the ways how mechanical/cybersensual fashion products express aesthetic characteristics of cybernetics, by comparing them with digital products designed by an application of cybernetics. The other goal is to provide a cultural and design framework of cybernetics as d digital-environmental medium for fashion in which hightech and human sensibilities are fused. The results urged to explore two new contrasting perceptual possibilities for an understanding of digital technology application: negative and positive feedbacks. Cybernetic optimism, centered on technological dimensions, focuses on a concept of fashion that emphasize instrumental aspects-efficiency and convenience. In contrast, cybernetic pessimism focuses on digital fashion that expresses environmental destruction and the loss of human identity. A comparative analysis of the aesthetics of expression in digital fashion design and digital industrial products from a cybernetic perspective showed that in digital environment society, the combination of negative and positive feedbacks resulted in design products in which internal and external aspects of beauty complemented each other.

• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.99-106
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• 1992

To prevent food-poisoning outbreaks by Vibrio vulnificus the antimicrobial efficacy of grapefruit seed extract (GFSE) was examined. Minimal inhibitory concentration (in vitro) for the microorganism was found to be 50∼100 ppm. Transmission electron micrographs of Vibrio vulnificus showed the biocidal action of this natural antimicrobial agent would be related to specific respiratory effect coupled with the destruction of permeable function of microbial cell membrane. After Anguilla japonica GFSE-injected to the body was incubated in the seawater contaminated by Vibrio vulnifiucs the fish meats were taken up, mixed with control diet and used as a diet in the feeding experiment. In this experiment the effect of GFSE treated with fish muscle on body weight, protein efficiency ratio, serum enzymes and serum blood components of broiler chicks was investigated. It is proved from this study that there is neither Vibriosis nor toxicity associated with GFSE itself an fish meats treated with it when it is injected to the fish body at a level of 250 ppm or less.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.3
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• pp.287-296
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• 2013

To decompose carbon dioxide, which is a representative greenhouse gas, a plasma torch was designed and manufactured. To examine the characteristics of carbon dioxide decomposition via plasma discharge, a case wherein pure carbon dioxide was supplied and a case wherein methane and/or $TiCl_4$ were injected as additives were investigated and compared. The carbon dioxide and methane conversion rate, energy decomposition efficiency, produced gas concentration, carbon monoxide and hydrogen selectivity, carbon-black and $TiO_2$ were also investigated. The maximum carbon dioxide conversion rate was 28.9% when pure carbon dioxide was supplied; 44.6% when $TiCl_4$ was injected as am additive; and 100% percent when methane was injected as an additive. Therefore, this could be explained that the methane injection showed the highest carbon dioxide decomposition. Furthermore, the carbon-black and $TiO_2$ were compared with each commercial materials through XRD and SEM. It was found that the carbon-black that was produced in this study is similar for commercial materials. It was found that the $TiO_2$ that was produced in this study is suitable for photocatalyst and pigment because it has mixed anataze and rutile.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1051-1060
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• 2008

The use of the coal ash for surcharge material, in a view of the environmental aspect, can decrease amount of the reclamation through recycling waste materials as well as prevent a destruction of the ecosystem attributed to sand picking. In addition, it can reduce both unit cost of material and construction expenses. In this study, new construction material as alternative surcharge material using coal ash, which is by-product from thermoelectric power plant, were developed. Mixing ratios of fly ash and bottom ash derived from the coal ash in Samchunpo thermoelectric power plants were determined. Furthermore, mixing conditions depending on the ratios of the cement and gypsum used for chemical additive were determined too. Uniaxial compression strength tests were conducted at different mixing conditions and Design graph of optimum mixing ratio at each required strength for economic efficiency is indicated in this paper.

• KIEAE Journal
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• v.8 no.2
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• pp.31-40
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• 2008

As horizontal expansion of a city reaches the uppermost limit, on the ground of perpendicular expansion and efficiency of land use, skyscrapers go on increasing in number. However, skyscrapers which were newly built in Korea have many problems such as consumption of enormous amounts of energy, destruction of natural environment, and traffic jam. And from now on, environment-friendly development of skyscraper is urgently needed. Therefore, in this study, we tried to find the planning elements and estimation indexes to improve the environment-friendly quality of high-rise residential architecture by investigating environment-friendly skyscraper certification in Korea and the other countries. For that reason, we investigated the application ratios of 10 cases in Korea. And the results showed that the application ratios of environment-friendly estimation indexes were lower than 50% and the environment-friendly quality of skyscrapers in Korea was generally low. Therefore, based on these planning elements and estimation indexes, we tried to establish the guideline of improvement direction for environment-friendly development of high-rise residential architecture in Korea.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.1
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• pp.65-72
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• 2012

Rankine cycle using ammonia-water mixture as a working fluid has attracted much attention, since it may be a very useful device to extract power from low-temperature heat source. In this work, the thermodynamic performance of regenerative ammonia-water Rankine cycle is thoroughly investigated based on the second law of thermodynamics and exergy analysis, when the energy source is low-temperature heat source in the form of sensible energy. In analyzing the power cycle, several key system parameters such as ammonia mass concentration in the mixture and turbine inlet pressure are studied to examine their effects on the system performance including exergy destructions or anergies of system components, efficiencies based on the first and second laws of thermodynamics. The results show that as the ammonia concentration increases, exergy exhaust increases but exergy destruction at the heat exchanger increases. The second-law efficiency has an optimum value with respect to the ammonia concentration.