• Analytical Science and Technology
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• v.11 no.4
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• pp.254-259
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• 1998

The adsorption and reduction characteristics of chromium(VI) by oak sawdust were studied. The optimum adsorption condition is obtained from the measurement of the distribution coefficient($K_d$) and adsorption capacity of Cr(VI) on the sawdust by changing pH of the solution. As a result, it was found that pH 2.0 was optimum because $K_d$ of Cr(VI) was maximum and reducing quantity was minimum. By the use of these characteristics of the oak sawdust, the removing of Cr(VI) in industrial waste water was examined.

• Environmental Engineering Research
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• v.7 no.1
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• pp.33-37
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• 2002

The two kinds of pellet-type red-mud adsorbents (bead-type, crushed-type) were from red mud, which is generated as a by-product during the production of aluminum hydroxide from bauxite ore. The adsorption experiments of Pb^{2+} ion in the aqueous solution by these red-mud adsorbents were studied with a continuous adsorption ccolumn. As a result, the crushed-type adsorbent shows better performance in adsorption of Pb^{2+} than the bead-type adsorbent between the two types of the pellet-type adsorbents. The continusous adsorption experiment shows that the pellet-type adsorbents made from red mud have good performance for removal of Pd^{2+}. The breakthrough curves of the red-mud adsorbents were compared with that of activated carbon.

• The Journal of Industrial Distribution & Business
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• v.7 no.1
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• pp.15-17
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• 2016

Purpose - During the past twenty years, China has developed rapidly in economy. Meanwhile China's economic development has brought great many problems. Sustainable development is to achieve coordination in the ecological, economic and social aspects. Among them, the environment and resource issues are the most critical issues which affecting sustainable development in China. With China's rapid economic development, China's ecological environment is facing the most serious threat in water pollution, air pollution, solid waste pollution and the destruction of forests and biodiversity, resulting in a significant loss of the national economy. This research aims to examine whether the tragedy of the commons has hindered the sustainable development of China's economy or not. On the other hand, we try to analyze a solution to improve this situation. Research design, data, and methodology - Theoretical background study, finding optimization models, and data analysis. Results - In the case of a clear definition of property rights, the air will have a market price. The market price will coordinate pollutant emissions. Conclusions - The tragedy of commons has hindered the sustainable development. The model of China's Economic development should be changed.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.333-341
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• 2017

Recently, the earth has shown the limit of environmental capacity. It is also experiencing an environmental crisis with rising energy prices and depletion of coal. Therefore, development of renewable energy is very important solution. However, waste fuel solid are renewable fuels, but they cause environmental problems. In this study, the emission characteristics of hazardous air pollutants were analyzed through measurements at the facilities using solid fuels (SRF, BIO-SRF). Analysis method of PAHs are based on the Korea Standard Methods for Examination. The analysis of PAHs showed that the concentration much higher in Naphthalene, and Benzo(a)pyrene showed at a higher concentration incertain sources. As a result of gas phase and particle phase PAHs, most of Benzo(a)pyrene appeared to be particulate. Through the results of this study will provide basic data for atmospheric environmental management.

• Journal of the Korean Solar Energy Society
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• v.23 no.1
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• pp.29-38
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• 2003

To develope chemical heat pump using available energy sources, solar heat and other kinds of waste thermal energy, we have studied the material and heat transfer rate in the cylindrical bed reactor packed with Calcined Dolomite. Our results from the studies are as follows ; 1 The time needed to complete dehydration reaction at the wall side of the cylindrical reactor(r/rL=0.5) was shorter than that of the center(r/rL=0.0) as much as 12%. 2. Two dimensional (radial and circumferential) partial differential equations, concerning heat and mass transfer rate in the packed bed of calcined Dolomite, are solved numerically to describe the characteristics of the reaction in the cylindrical reactor. The solution reads rate of reaction in the packed bed reactor depends on the temperature and concentration of reactants. These results read the supplied heat transfers from the wall side of the cylinder to the center, dehydration reaction begins at the inner side of the wall of the cylindrical reactor and the dehydration reaction proceeds from the wall side to center of cylinder.

• The Korean Journal of Mycology
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• v.9 no.2
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• pp.49-66
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• 1981

The objectives of this investigation were to produce artificially an antitumor constituent by submerged culture of the mycelium of Coriolus versicolor (Fr.) Quel., to characterize the influence of various modifications of the nutrient and culture conditions with respect to the pro­duction, to determine chemical composition of the antitumor constituent, and to examine effects of the constituent on the immune response of mice. Submerged agitation of the mycelium in flasks containing a nutrient solution showed its adequate growth. Especially the mycelial growth in the medium containing glucose and yeast extract was abundant. The addition of cotton seed flour or ginseng waste to the medium increased the yield of mycelial growth and the production of the antitumor constituent. The replacement of glucose with starch also yielded the adequate growth. The antitumor constituent extracted from the mycelium and isolated from the culture filtrate was a protein-bound polysaccharide. The analyses of this constituent by GLC and amino acid autoanalysis showed that it contained four monosaccharides and fifteen amino acids. The protein-free polysaccharide of the constituent was also found to exert greater antitumor activity against sarcoma-180 in mice than the entire constituent. The antitumor constituent was found to potentiate the immune response of mice against sheep red blood cell. The protein-bound polysaccharide exerted more favorable influence on the immunity than the protein-free moiety.

• Nuclear Engineering and Technology
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• v.21 no.4
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• pp.267-276
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• 1989

A numerical model for nuclide migration through fractured rock media has been developed. Nuclide transport with groundwater in rock fissures and the diffusion of nuclides into rock matrix are considered one-dimensionally . In the safety assessment of the repository for radioactive waste, this one-dimensional model by the finite-difference scheme, which enables us not only to use more realistic boundary conditions but also to model the nonhomogeneous rock medium as the multilayered media, can be used effectively with the analytical mode. The solution by the numerical model will be verified analytically, and then extended to the double-layered rock medium transport model.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.47-53
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• 2013

Silk sericin (SS) has been fabricated into beads using a 1 M LiCl/DMSO solvent and utilized as a heavy metal adsorbent. Among the various heavy metals, we targeted Cr(VI) for adsorption using SS beads and found that its adsorption depended on the coagulant used for the fabrication of the SS beads. When methanol was used as a coagulant, the beads had a better adsorption capacity than when ethanol was used except at pH 1. The adsorption behavior of Cr(VI) on the SS beads followed the BET isotherm. The maximum adsorption capacity was 33.76 mg/g at pH 2. The adsorption of Cr(VI) was confirmed by FT-IR and EDS analyses. Finally, the desorption was carried out using NaOH solution, and it was found that 73.19% of the adsorbed Cr(VI) could be detached.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1471-1480
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• 2020

This research presents a case study on the remediation of a radioactive waste (uranium: U) utilizing a multi-objective fuzzy optimization in an electrocoagulation process for the iron-stainless steel and aluminum-stainless steel anode/cathode systems. The incorporation of the cumulative uncertainty of result, operational cost and energy consumption are essential key elements in determining the feasibility of the developed model equations in satisfying specific maximum contaminant level (MCL) required by stringent environmental regulations worldwide. Pareto-optimal solutions showed that the iron system (0 ㎍/L U: 492 USD/g-U) outperformed the aluminum system (96 ㎍/L U: 747 USD/g-U) in terms of the retained uranium concentration and energy consumption. Thus, the iron system was further carried out in a multi-objective analysis due to its feasibility in satisfying various uranium standard regulatory limits. Based on the 30 ㎍/L MCL, the decision-making process via fuzzy logic showed an overall satisfaction of 6.1% at a treatment time and current density of 101.6 min and 59.9 mA/㎠, respectively. The fuzzy optimal solution reveals the following: uranium concentration - 5 ㎍/L, cumulative uncertainty - 25 ㎍/L, energy consumption - 461.7 kWh/g-U and operational cost based on electricity cost in the United States - 60.0 USD/g-U, South Korea - 55.4 USD/g-U and Finland - 78.5 USD/g-U.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2732-2736
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• 2011

In pH 4.2 HAc-NaAc buffer solution, horseradish peroxidase (HRP) catalyzed $H_2O_2$ oxidation of nanosilver to form $Ag^+$. After centrifugation, $Ag^+$ in the supernatant can be measured by graphite furnace atomic absorption spectrophotometry (GFAAS) at the silver absorption wavelength of 328.1 nm. When HRP concentration increased, the $Ag^+$ concentration in the supernatant increased, and the absorption value enhanced. The HRP concentration in the range of 0.84-50 $ng{\cdot}mL^{-1}$ was linear to the enhanced absorption value (${\Delta}A$), with a regression equation of ${\Delta}A$=0.012C+0.11, correlation coefficient of 0.9988, and detection limit of 0.41 $ng{\cdot}mL^{-1}$ HRP. The proposed GFAAS method was used to detect HRP in waste water samples, with satisfactory results.