• KIEAE Journal
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• v.8 no.1
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• pp.25-30
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• 2008

This study aims at examining the reduction of indoor air contaminants by plants placed in an indoor space. The effect of reducing the concentration of air contaminants by three species of plants was studied in a full-scale mock-up model. Field measurements were performed using Aglaonema brevispathum, Pachira aquatica and Ficus benjamiana which were verified as air-purifying plants by NASA. Their positions and amount were controlled. Two conditions for the amount of plants(10%, 5%) and positions(sun-shine, scatter) were used in two separate rooms whose dimensions are identical. The concentration of Volatile Organic Compounds(VOCs) was monitored three hours after the plants were placed and three days after the plants were placed. The variations of concentration of Benzene, Toluene, Etylbenzene, Xylene, Stylene and Formaldehyde, which are all known as the major elements of Volatile Organic Compounds were monitored. The more plants were used, the more a reduction of indoor air contaminants occurred. The effect of reducing the concentration of air contaminants increased when the amount of plants increased.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.13-22
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• 2013

This paper reports the investigation of the physical and chemical characteristics of the prepared 3Pt-2MgO-$3ZrO_2$-$2CeO_2/Al_2O_3$ DOC, based on its hydrothermal aging. As a result of impregnating and reducing the $H_2PtCl_6$ $6H_2O$ precursor on a ${\gamma}-Al_2O_3$ basis, it was well dispersed into small particles with the range 2-3nm. This was because the $Al_2O_3$ acted as a barrier to prevent movement of the catalyst particles. For a hydrothermally aged catalyst for 9h at $700^{\circ}C$, its performance when purifying harmful gases decreased compared to a fresh catalyst, but its specific surface area was at the same level. This was because the performance of the catalyst was reduced by the sintering of the precious metal Pt, rather than by washcoat sintering and pore clogging. For an excessively hydrothermally aged catalyst for 9h at $850^{\circ}C$, Pt grew into an approximately 50nm class, formed a cluster compared to a fresh catalyst. The $CeO_2$ promoters also formed clusters among components of the same type, reducing their specific surface area to $114m^2/g$, which was 14% less than a fresh catalyst.

• Journal of the Korean Chemical Society
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• v.35 no.4
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• pp.410-413
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• 1991

A tripledecker sandwichcomplex, bis(${\eta}^5$-cyclopentadienyl)-${\mu}$-(${\eta}^6$-2,3-dialkyl-1,4-dimethyl-1,4-dibora-2,5-cyclohexadiene)dicobalt 1 was synthesized as a starting material. By the reaction of compound 1 with the excess 3-hexyne two kinds of sandwichcomplexes, cyclopentadienyl(${\eta}^6$-2,3-dialkyl-1,4-dimethyl-1,4-dibora-2,5-cyclohexadiene)cobalt 2 and cyclopentadienyl(${\eta}^6$-hexaethyl benzene)cobalt 3 were separated. The complex 3 was decomposed during purifying at RT to give a cyclization product of 3-hexyne, hexaethyl benzene.

• Journal of Magnetics
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• v.22 no.2
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• pp.214-219
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• 2017

Magnetic separators that clean the fluid stream from impurities, protect the installations in numerous industries. This paper introduces a graphical user interface (GUI) which proposes an optimized coil separating magnetic particles with a radius from 1 up to 500 µm. High gradient magnetic fields are employed in an arbitrary user defined fluidic channel which is made of a nonmetallic material. The effects of coil parameters are studied and adjusted to design an optimum coil with a minimum Ohmic loss. In addition, to design the coil scheme based on the particle movements, a mathematical particle-tracing model within the fluid channels has been utilized. In comparison to conventional magnetic separators, this model is reconfigurable by the user, produces a weaker magnetic field, allows for continuous purifying and is easy to install, with high separation efficiency. The presented GUI is simple to use, where the coil's manufacturing limitations can be specified.

• The Korean Journal of Rehabilitation Nursing
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• v.14 no.2
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• pp.118-128
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• 2011

Purpose: The purpose of this study was to explore the experiences of bereavement for main family members who had made and followed DNR decision for their family members. Method: This qualitative study was based on a grounded theory, and used in-depth interview techniques with the bereaved 10 main family members who had been treated and died under DNR order. Results: The causal condition of the family member was 'Releasing', and the main consequent phenomenon were 'Blaming self and ruminating'. The contextual condition was 'The memory of the deceased'. The action/reaction strategy was 'Purifying'. The intervening condition was 'Supporting system', and the consequence was 'Acceptance'. The experience after bereavement of the family member on DNR decision were rational processes that purified themselves and healed the guilt feeling about the decision from reflective assessment and response about DNR decision. Based on this results, the substantive theory 'Reflective self healing' was derived. Conclusion: The main family members in following DNR decision are more likely to have unhealthy emotional condition than others in normal bereavement process. But they overcame the grief of bereavement through reflective self healing process.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.5
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• pp.1-9
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• 2005

This study was conducted to investigate the effect of aquatic plant as a botanical air purification on the indoor air pollution by formaldehyde. Three aquatic plants such as Eichhornia crassipes, Cyperus alternifolius, Echinodorus cordifolius, were selected for this study and they were placed in the artificially contaminated chamber under laboratory condition. The results showed that all three plants could remove the formaldehyde from the contaminated air system effectively. Reduction in the formaldehyde levels by Eichhornia crassipes, which is the floating plant, might be associated with the factors of plant and water. Reduction in the formaldehyde levels by Cyperus helferi and Echinodorus cordifolius, which were emergent plant, was due to the complex effect of plant, soil medium and water. In aquatic plant system, dissolution, microbial degradation in rhizosphere, uptake through root and shoot, sorption to soil and shoot, hydrolysis are known as the main mechanisms of water soluble pollutants in the given system. The advantages of indoor air quality control system using aquatic plants can be; 1) various purifying mechanisms than foliage plants, 2) effective for decontamination of water soluble pollutants; 3) easy for maintenance; 4) diverse application potential. Therefore it was suggested from the results that indoor air control system of aquatic plants should be more effective for reduction of indoor air pollutants.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.65-72
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• 2013

The physical, mechanical, water purification and temperature properties of fiber reinforced porous hwang-toh green roof concrete have been evaluated in this study. The effect of the depending on replacement ratio of blast furnace slag to cement was investigated such that the replacement ratio is varied to 0 % and 30 %. Also, the replacement ratios of hwang-toh were 0, 20 and 30 %. The polyvinyl alcohol fiber was used for the reinforcing fiber. A series of pH test, unit weight, void ratio, compressive strength, after purification and variation of temperature test have been performed to evaluate the performance, water purification effect and temperature properties of the fiber reinforced porous hwang-toh green roof concrete. The test results indicate that the physical and mechanical properties of fiber reinforced porous hwang-toh green roof concrete is affected by the replacement ratio of the blast furnace slag and hwang-toh contents. Results of purifying water showed that the water purification effect of porous hwang-toh green roof concrete is about 40 %. Also, the temperature properties test results indicate the green roof blocks using fiber reinforced porous hwang-toh green roof concrete have insulation and temperature reduction effect.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.185-189
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• 1985

Extracellular $\beta$-galactosidase from the culture broth of L. sporogenes was purified to apparent homogeniety by procedures including ammonium sulfate fractionation, Sephadex G-200 gel filtration, DEAE-Sephadex A-50 ion exchange chromatography, and Hydroxyapatite adsorption chromatography. The purifying procedures resulted in 347-fold purification with the overall yield of 39.5％ The purified enzyme had a specific activity(using ONPG as a substrate) of about 1, 585 units per mg protein. The molecular weight of the enzyme protein was estimated to be 140, 000 by gel filtration on Sephadex G-200, and SDS-polyacrylamide gel electorphoresis showed that the enzyme consisted of two identical subunits with a molecular weight of 72, 000.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.556-561
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• 2017

Serving as an excellent adsorbent and inorganic ion exchanger in the water purification field, zeolite 4A has in this work presented a strong capability for purifying radioactive waste, such as $Sr^{2+}$, $Cs^+$, and $Co^{2+}$ in water. During the processes of decontamination and decommissioning of suspended solids and organics in low-level radioactive wastewater, the purification performance of zeolite 4A has been studied. Under ambient temperature and neutral condition, zeolite 4A absorbed simulated radionuclides such as $Sr^{2+}$, $Cs^+$, and $Co^{2+}$ with an absorption rate of almost 90%. Additionally, in alkaline condition, the adsorption percentage even approached 98.7%. After conducting research on suspended solids and organics of zeolite 4A for the treatment of radionuclides, it was found that the suspended clay was conducive to absorption, whereas the absorption of organics in solution was determined by the species of radionuclides and organics. Therefore, zeolite 4A has considerable potential in the treatment of radioactive wastewater.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1717-1722
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• 2021

This study is devoted to the ability of carbon fiber material samples impregnated with various amounts of barium iodide and triethylenediamine to remove radioactive methyliodide from air streams. The main sorption characteristics of impregnated UVIS® carbon fiber were determined and the use of this material for purifying of technological gas flows at nuclear power plants was evaluated. The methyliodide trapping efficiency by samples impregnated with barium iodide, TEDA, and their mixture was 83.4 ± 0.8%; 93.1 ± 0.6% and 93.5 ± 0.7% respectively, under the same conditions. The study established a significantly higher capacity (8.3 ± 0.07 mg/cm²) of samples impregnated simultaneously with both chemical compounds toward methyliodide. Under the same test conditions, the values of this parameter for the samples impregnated separately with TEDA and BaI₂ were 2.85 ± 0.05 mg/cm² and 0.86 ± 0.04 mg/cm², respectively.