• Clean Technology
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• v.6 no.1
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• pp.51-60
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• 2000

The soil remediation by non-ionic surfactant solutions ($C_{12}H_{25}O(CH_2CH_2O)_5H$ and Triton X-100) was studied. Depending on the amounts and use of co-surfactants, MPT(phase inversion temperature), dynamic interfacial tension, and the detergency efficiency of the surfactant solutions in soil were investigated. The oils used were kerosene, n-hexadecane, and paraffin oil. With respect to a higher detergency efficiency, a lower interfacial tension and the MPT was very important. The $C_{12}H_{25}O(CH_2CH_2O)_5H$ was better than Triton X-100 on the oil removal from the soil and the effect of oil kinds was kerosene>paraffin $oil{\geq}n-hexadecane$. The co-surfactant, n-dodecanol, reduced the MPT compared to no addition of this, whereas it did not enhance the detergent efficiency.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.341-350
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• 2014

The occurrence of insect pests of Lycium chinense was monitored at 4 organic farms that was cultivated with environment-friendly management at Cheongyang, Chungnam from May, 2012 to September, 2014. Total 4 orders and 18 species occurred in the L. chinense. Among them, 4 major pests and Lepidopteran and Hemipteran insect pests were investigated the occurrence pattern. During the budding, the population density of Myzus persicae was very high in late-May and early-June, and the injury by Lema decempunctata was increased from mid-June. The injuries by Henosepilachna vigintioctomaculata and Hedma lycia sp. were continued throughout the growing season. From the fruit held in late-July, hemipteran insects including Plautia stali and Halyomorpba balys were sucking the fruit, and their injury to L. chinense were gradually increased. In the case of Eriophys macrodonis densities to increase gradually from early July. The population density of E. macrodonis in 2014 was rapidly increased more than 5 times compared with 2012 and 2013. It was supposed that the initial control of mites or the removing of over-wintering density in the past year might be neglected. However, there is a need to more review the factors for the mass occurs.

• Journal of Periodontal and Implant Science
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• v.39 no.3
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• pp.367-373
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• 2009

Purpose: Following tooth extraction caused by severe periodontitis, alveolar ridge dimension lose their original volume. To reduce the alveolar ridge dimension, the ridge preservation technique has been introduced and tested in many clinical studies with membrane alone or membrane plus graft, achieving reduced ridge loss compared to extraction only. The aim of the present clinical study was to compare the post-extraction dimensional changes in the membrane exposure group to non-exposure group during healing period following ridge preservation technique. Methods: Ridge preservation was performed in 44 extraction sites. After extraction, deproteinized bovine bone mineral coated with synthetic oligopeptide (Ossgen-$X15^{(R)}$) or deproteinized bovine bone mineral (Bio-$Oss^{(R)}$) was implanted into the socket. A collagen membrane (Bio-$Gide^{(R)}$) was trimmed to cover the socket completely and applied to the entrance of the socket. Four clinical parameters were compared between baseline and 6 months. Results: During healing period, membrane exposure was observed at 19 sites. At the re-entry, hard newly formed tissue were observed at the ridge preservation site. The grafted socket sites were well preserved in their volume dimension. In both groups, horizontal ridge width was reduced and vertical height was increased. There were not statistically significant differences in horizontal (-1.32 mm vs -1.00 mm) and vertical ridge change (2.24 mm vs 2.37 mm at buccal crest, 1.36 mm vs. 1.53 mm at lingual crest) between two groups. Conclusions: The ridge preservation approach after tooth extraction effectively prevented resorption of hard tissue ridge in spite of membrane exposure during healing period.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.6
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• pp.577-585
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• 2014

Nanorod and particle shape $CeO_2$ were synthesized via hydrothermal process and precipitation method, respectively, and used as supports of Pt catalyst for water gas shift (WGS) reaction. Three different durations (12, 48, and 96h) for hydrothermal process were applied for the preparation of nanorod type $CeO_2$. 1.0 wt% of Pt was loaded on the prepared supports with incipient wetness method prior to the catalytic activity tests that were carried out at a GHSV of $95,541h^{-1}$, and a temperature range of 200 to $360^{\circ}C$. Varying duration of hydrothermal process led to the difference in physical characteristics of $CeO_2$ nanorods, such as aspect ratio, BET surface area, pore diameter, and pore volume. Consequently, the catalytic activities of Pt/$CeO_2$ nanorods were affected by the physical characteristics of the supports and appeared to be in the order of Pt/$CeO_2$(12) > Pt/$CeO_2$(48) > Pt/$CeO_2$(96). The comparison of the catalytic activities and results of the analysis (XPS, XRD, SEM, BET and TPR) for the supports revealed that the activity of the catalysts depends on chemical states of the Pt and the support materials in the temperature range that is lower than $280^{\circ}C$. However, the activity is rather dependent on the physical characteristic of the supports because the increased gas velocity limits the mass transfer of reactants in micropores of the supports.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.1
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• pp.1-8
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• 2017

Cu/Mn/Ce catalysts for water gas shift (WGS) reaction were synthesized by urea-nitrate combustion method with the fixed molar ratio of Cu/Mn as 1:4 and 1:1 with the doping concentration of Ce from 0.3 to 0.8 mol%. The prepared catalysts were characterized with SEM, BET, XRD, XPS, $H_2$-TPR, $CO_2$ TPD, $N_2O$ chemisorption analysis. The catalytic activity tests were carried out at a GHSV of $28,000h^{-1}$ and a temperature range of 200 to $400^{\circ}C$. The Cu/Mn(CM) catalysts formed Cu-Mn mixed oxide of spinel structure ($Cu_{1.5}Mn_{1.5}O_4$) and manganese oxides ($MnO_x$). However, when a small amount of Ce was doped, the growth of $Cu_{1.5}Mn_{1.5}O_4$ was inhibited and the degree of Cu dispersion were increased. Also, the doping of Ce on the CM catalyst reduced the reduction temperature and the base site to induce the active site of the catalyst to be exposed on the catalyst surface. From the XPS analysis, it was confirmed that maintaining the oxidation state of Cu appropriately was a main factor in the WGS reaction. Consequently, Ce as support and dopant in the water gas shift reaction catalysts exhibited the enhanced catalytic activities on CM catalysts. We found that proper amount of Ce by preparing catalysts with different Cu/Mn ratios.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.145-153
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• 2015

$Cr_2O_3/AP$ (ammonium perchlorate) energetic composites were prepared by a method of solvent/anti-solvent. XRD analysis revealed that the crystalline structure of AP in $Cr_2O_3/AP$ composites is the same as that of pure AP. SEM photomicrograph shows that an average size of cuboid $Cr_2O_3/AP$ composites is approximately $2.5{\mu}m$. TGA analysis shows that the addition of submicron $Cr_2O_3$ particles into AP lowers the HTD (high-temperature decomposition) compared to that of neat AP and the activation energy of the $Cr_2O_3/AP$ composites was calculated by the isoconversional Starlink method. Considering changes in the activation energy, the decomposition reaction mechanism of AP was suggested as follows; the decomposition with the formation of nucleation sites renders formation of porous structure in the composites up to conversion of about 0.25 and after further conversion of over 0.3, it seems that decomposition reaction vigorously takes place rather than sublimation of AP.

• Journal of fish pathology
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• v.12 no.2
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• pp.73-81
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• 1999

To study the supplementaing effects of kugija, Lycium chinense, in commercial diet on the immune response of nile tilapia, Oreochromis niloticus, nonspecific immune responses were investigated. The activities of complement and lysozyme were higher in sera of the fish fed diet with kugija than control diet. The effects of kugija on vaccination of fish to Edwardsiella tarda were compared in three different vaccination methods after feeding kugija for ten weeks. Intraperitoneal injection and bath administration with formalin killed cells (FKC) and bath with extracellular products (ECP) after injection of FKC showed differences in immune responses of vaccinated fish. Bath administration with ECP after injection of FKC was more stimulated than any other methods in each of nonspecific and specific responses such as the activities of complement and lysozyme, antibody production and rosette forming cells. Moreover, cumulative mortality was significantly lower in the fish vaccinated with combination FKC and ECP after injection challenge with live E. tarda.

• Korean Journal of Construction Engineering and Management
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• v.5 no.1 s.17
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• pp.99-106
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• 2004

Efficiency and efficient management on maintenance/repair/operation (MRO) phase is getting important with advance in technologies and complex functionalities of building and facility, Using software systems as well as advanced hardware systems in MRO area is spreading along with this trend to take advantage of information technology. Information of building and facility for MRO phase is derived from engineering/procurement/construction (EPC) phase. But most current commercial software systems in EPC and MRO are focusing on their own phase, which arise lack of consistency of information from EPC to MRO phase. But, the information system now used at the MRO phase stop flowing the building and the facilities information and then newly create. Moreover, from an asset management point of view, asset particulars such as the structures and equipments are different the value fluctuation. In order to reflect these information rationally, the construction costs are correctly distributed and the initial price of the asset particulars have to be estimated. In this study, develop the information model which can apply the cost information at the EPC phase to the MRO phase.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.317-325
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• 2010

This study aims to deduct the extensive improvement types of leisure activities of private security agents using PPA technique and to examine the influence of leisure constraint on the index of participation. Through this process, this study consequently will draw the priority list of investment on the policy for improving the welfare status of private security agents. In this study, judgement sampling was applied to 6 security agencies located in Seoul, 2010, and 267 cases were used in the final analysis. Collected data went through factor analysis, reliability analysis, paired t test, PPA analysis, and regression analysis by using SPSSWIN 17.0. The conclusions were drawn as follows. In regard to the reliability, Cronbach's $\alpha$ was over .768. First, there was a difference between the preference rate and the participation rate which are the participation index of the private security agents' leisure activities. concentrate here in leisure types turned out to be fitness activities, walking/jogging, tourism, a day-long travel, and keep up the cood work in leisure types are movies, domestic tourist attractions, dating, eating out, personal relationship, watching sports, reading, karaoke, TV video watching, drinking etc. low priority in leisure types are water sports, hiking, biking, soccer, photography, ball games, sky sports, playing go/janggi, inline skates, and cooking. Second, the leisure constraint affects the participation index of leisure activities. As the personal constraint, and surrounding conscious constraint which are the subordinate factors of the leisure constraint get bigger, the participation index of favored leisure activities become lower. In contrast, when the difficulties such as structural constraint, time and economical constraint are overcome, participation index of leisure activities go on the rise.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.155-155
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• 2011

용융탄산염 연료전지(MCFC)는 $650^{\circ}C$에서 작동하는 고온형 연료전지 시스템이다. 이 시스템은 천연가스 등을 개질하여 생산된 수소를 바로 전기로 생산할 수 있는 시스템으로 열효율이 높으며, 현재 대체 발전시스템으로 각광을 받고 있다. MCFC는 개질방식에 따라 내부개질 방식과 외부개질 방식이 있다. 내부개질 방식은 수소를 생산하는 개질기가 스택내부에 장착된 형식으로 천연가스를 스택내부에서 개질하여 바로 전기를 생산하는 방식이다. 이 내부개질반응에 사용되는 촉매로는 알루미나에 고함량 (약 50 wt.%)으로 담지된 니켈(Ni) 계열촉매이 주로 쓰이고 있다. 이 고함량으로 담지된 촉매는 대부분 높은 활성을 보인다. 비교적 낮은 온도 운전조건 (약 $580{\sim}620^{\circ}C$)을 가지는 MCFC 내부개질에 적용하기 위해서는 활성점인 니켈을 최대한 담지체에 고르게 분산 시켜야한다. 이를 위해서 MgO를 이용하여 촉매의 활성점을 높게 분산시키는 연구를 진행 하였다. 촉매를 제조하는 방법으로 요소(urea)를 이용한 균일용액침전법을 이용하였다. 니켈함량은 50 wt.%로 고정을 한 다음, MgO 양과 $Al_2O_3$ 양을 각각 0 ~ 45 wt.%와 5 ~ 50 wt.%로 조절하면서 촉매를 제조하여 그 특성들을 분석하였다. 물성을 비교하기 위해서, X-선 회절분석 (XRD) 및 TPR, 물리화학흡착 실험을 하였다. 촉매의 활성을 살펴보기 위해서, fresh 상태 및 피독 상태에서 메탄수증기 개질활성 실험을 실시하였다. MgO 함량이 없거나 적은 촉매에서는 높은 BET surface area와 작은 NiO, metallic Ni 결정 크기가 나타났다. 반면 MgO 함량이 높은 촉매에서 낮은 BET surface area와 비교적 큰 NiO, metallic Ni 결정 크기가 나타났다. 또한 XRD 분석에서 MgO 함량이 증가할 수 록 MgO 결정 피크가 명확히 나타났으며, $MgAl_2O_4$ 피크는 나타나지 않았다. TPR 분석에서 촉매들의 환원 피크를 측정한 결과, 저함량의 MgO를 포함한 촉매는 $700^{\circ}C$ 부근에 환원 피크가 관찰되었고 MgO가 고함량인 촉매는 환원 피크가 $400^{\circ}C$ 부근에서 관찰되었다. 촉매의 초기 fresh 상태에서의 활성은 고함량 MgO를 포함한 Ni-90M10A 샘플을 제외하고 모든 촉매가 거의 비슷하게 나타났다. 그러나 $K_2CO_3$ 피독 상태에서는 MgO 함량이 증가할 수 록 활성이 좋지 않았음을 알 수 있었다. 따라서 MgO가 소량 포함된 촉매의 경우 fresh 상태에서는 우수한 물성과 활성을 보이지만, 피독상태에서는 MgO가 포함되지 않은 Ni-$Al_2O_3$ 촉매가 우수한 활성을 보였다.