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Electrochemical Performances of Lithium-air Cell with Carbon Materials

  • Park, C.K.;Park, S.B.;Lee, S.Y.;Lee, H.;Jang, H.;Cho, W.I.
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3221-3224
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    • 2010
  • This study investigates the requirements of lithium-air cathodes, which directly influence discharge capacity. The cathodes of Li-air cell are made by using five different carbon materials, such as Ketjen black EC600JD, Super P, Ketjen black EC300JD, Denka black, and Ensaco 250G. The Ketjen black EC600JD provides discharge capacity of 2600 mAh/g per carbon weight, while that of Ensaco 250G shows only 579 mAh/g. To figure out the differences of discharge capacity from carbon materials, their surface area and pore volume are analyzed. These are found out to be the critical factors in determining discharge capacity. Furthermore, carbon loading on Ni foam and amounts of electrolyte are significant factors that affect discharge capacity. In order to investigate catalyst effect, electrolytic manganese dioxide (EMD) is incorporated and delivered 4307 mAh/g per carbon weight. This infers that EMD facilitates to break $O_2$ interactions and leads to enhance discharge capacity.

SRF LINAC FOR FUTURE EXTENSION OF THE PEFP

  • Kim, Han-Sung;Kwon, Hyeok-Jung;Seol, Kyung-Tae;Jang, Ji-Ho;Cho, Yong-Sub
    • Nuclear Engineering and Technology
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    • v.46 no.2
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    • pp.247-254
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    • 2014
  • A study on the superconducting RF linac is underway in order to increase the beam energy up to 1 GeV by extending the Proton Engineering Frontier Project (PEFP) 100-MeV linac. The operating frequency of the PEFP superconducting linac (SCL) is 700 MHz, which is determined by the fact that the frequency of the existing normal conducting linac is 350 MHz. A preliminary study on the beam dynamics showed that two types of cavities with geometrical betas of 0.50 and 0.74 could cover the entire energy range from 100 MeV to 1 GeV. An inductive output tube (IOT) based RF system is under consideration as a high-power RF source for the SCL due to its low operating voltage and high efficiency. As a prototyping activity for a reduced beta cavity, a five-cell cavity with a geometrical beta of 0.42 was designed and fabricated. A vertical test of the prototype cavity at low temperatures was performed to check the performance of the cavity. The design study and the prototyping activity for the PEFP SCL will be presented in this paper.

Introduction to the Intelligent Excavating System: Concept design of Intuitive Operator Control Unit (지능형 굴삭시스템 개발: 직감형 원격제어 시스템 개념설계)

  • Yu, Byung-Gab;Lee, Seung-Yeol;Lee, Sang-Ho;Yu, Seok-Jong;Yu, Bo-Hyun;Jang, June-Hyun;Han, Chang-Soo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.68-73
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    • 2007
  • Civil engineering construction work has always been accompanied by a high proportion of tasks that are either dangerous or unpleasant or both. Enhancing the general working environment and boosting safety levels are critical issues for the industry. In addition to that, the industry has been slow to utilize automation & robot technology, and there is substantial scope for the use of technology th boost efficiency, cut costs and improve quality levels in construction. In a bid to address this issue, Ministry of Construction & Transportation launched a five-year project in 2003 entitled Development of Intelligent Excavating System. The aim of the project is to use telecommunications and robotics technology to minimize inefficiencies and eliminate the dangerous and unpleasant aspects of tile construction process through the development of specific applications such as IT-equipped construction machinery and advanced construction management systems. In this paper, the project introduces on the research and development content related to multi-disciplinary, a intuitive operator control unit(Robot Technology) included.

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Present State and Statistical Analysis of Stone Cultural Heritage by National Appointment in Republic of Korea (국내 국가지정 석조문화재의 현황과 통계분석)

  • Jun, Byung-kyu;Han, Min-su;Lee, Jang-jon;Song, Chi-young
    • 보존과학연구
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    • s.27
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    • pp.43-61
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    • 2006
  • In this study stone heritages of 533 which is to be investigated through the five years for national treasures and treasures from 2001 to 2005 have been analyzed by statistics for types of stone heritages and rocks, level of alteration in order to make full use of guiding principle in conservation management of stone heritages. The ratio of stone pagoda as a percentage of 34.5% in the stone heritages much higher than others and that is composed of granite(83.0%) in the igneous rock. In the weathering index of surface, a 37.5% of the national treasures were classified with the level 4 and46.3% of the treasure were the level 3 according to state. The present condition of organism distribution take up 30.6% for the level 3 and 22.1% for level 1. In structural stability index, a 40.6%of the national treasures and a 54.2% of treasure were ranked level 3.

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Application of a solid-phase fluorescence immunoassay to determine ampicillin residues in muscle tissue of olive flounder (Paralichthys olivaceus)

  • Jung, Won Chul;Ha, Ji Young;Chung, Hee Sik;Heo, Sung Hyeok;Kim, Suk;Lee, Hu Jang
    • Korean Journal of Veterinary Research
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    • v.46 no.3
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    • pp.291-294
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    • 2006
  • $Parallux^{TM}$, a solid-phase fluorescence immunoassay(SPFIA) developed for antibiotics residue detection in milk, was applied for analysis of fish muscle. The recommended therapeutic dose of ampicillin(100 mg/kg body weight, withdrawal period 7 days) was orally administered to a group of 25 olive flounders(Paralichthys olivaceus) for consecutive five days. Muscle was sampled after drug treatment 1st, 2nd, 3rd, 4th and 5th day. The concentration of ampicillin in muscle, determined by SPFIA, was compared with that of internal standard(10 ppb as ampicillin). The absorbance ratio of sample to internal standard(Bs/Bo) was employed as an index to determine the muscle residue in olive flounder. To investigate the recovery rate, the standard solutions were added to muscle samples to give final concentrations in muscle of 10 and 50 ng/ml. The recovery rates of all spiked samples were > 89% of the spiked value. Ampicillin was detected in muscle of fishes treated until the 3rd day of withdrawal period. The present study showed that the SPFIA can be easily adopted in predicting tissue residues for ampicillin in farmed fishes.

Consideration of the Effectiveness of Moxibustion and Acupuncture for the Treatment of Fetal Breech Presentation (태아 둔위의 침구치료에 대한 효용성 고찰)

  • Kang, Kiwan;Lee, Eun;Lee, Seungho;Jang, Insoo
    • Korean Journal of Acupuncture
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    • v.30 no.1
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    • pp.16-20
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    • 2013
  • Objectives : The objective of this study is to report the efficacy of acupuncture and moxibustion for the treatment of fetal breech presentation. Methods : We searched papers in PubMed, using the keywords "breech and moxibustion" and "breech and acupuncture". Search range includes randomized clinical trials(RCTs), controlled clinical trials(CCTs), case reports, and case series. Each original article must have an abstract in English. Finally, 7 RCTs from 102 were included in this review. Results : As a result of analyzing the 7 RCTs, five trials hold that moxibustion or acupuncture at BL67 has been shown to produce a positive effect for the correction of breech presentation and the other two trials indicated no beneficial effect. However, one of the latter could not come to a conclusion owing to the unsatisfactory compliance record of the participants. Conclusions : Acupuncture and moxibustion may be effective to correct fetal breech presentation. In this regard, the related clinical researches are worth to be conducted.

Comparison of the Antibacterial Activity of Domestic Cirsium japonicum Collected from Different Regions (지역별 국내 자생 엉겅퀴 추출물의 항균 활성)

  • Jang, Miran;Park, Hyejin;Hong, Eunyeong;Kim, Gun-Hee
    • Korean journal of food and cookery science
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    • v.30 no.3
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    • pp.278-283
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    • 2014
  • This study was investigated the antibacterial activities of Cirsium japonicum from extracts five regions(Chungnam, Gyeonggi, Gangwon, Jeju and Jeonnam) extract against six food-borne pathogenes(Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella enterica and Vibrio vulnificus) using the broth dilution and agar diffusion method. At concentrations between 0 and $750{\mu}g/mL$ the extracts showed an antibacterial effect against all tested bacteria. The antibacterial activities of Cirsium japonicum from Jeju and Gangwon are stronger than others. The minimum inhibitory concentration(MIC) values against the six bacteria ranged from 93.75 to $750{\mu}g/mL$. In time killing assay(cell growth curves), the tested bacteria inactivated upon exposure to the extracts for 24h. At the 24h exposure to the extracts, all bacteria were inhibited to over 70% for growth. In particular, Bacillus subtilis, Salmonella enterica and Vibrio vulnificus conveyed an inhibition of growth to almost complete. It is anticipated that Cirsium japonicum extracts may have greater potential as natural food preservatives.

A Study on the Valuation of Real Estate Using the Applies Real Option Model Considering Population Structure Changes (실물옵션 기법을 응용한 부동산 가치평가 연구: 인구구조 변화를 고려하여)

  • Gu, Seung Hwan;Ping, Wang;Jang, Seong Yong
    • Korean Management Science Review
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    • v.31 no.1
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    • pp.17-26
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    • 2014
  • This study presents a new real estate value analysis model considering the changes in the population structure. We propose a new model that takes advantage of the binomial option model one of the techniques of real options and considers the changes in the population structure. The real estate market price data of Seoul city from year 2001 to 2012 were extracted and the correlation analysis between real estate prices and changes in the population structure was performed. The result shows that they have positive correlation with one year time lag. The coefficient between the real estate prices and demographic changes was estimated using the OLS analysis and included in the traditional binomial option model to calculate the value of the property. It is assumed for the future price prediction that real estate invested in Seoul in January, 2013 will be sold within five years. Analysis result shows that the values of real estate in September of 2013 were predicted as 583.5 million won in the new model and as 582.4 million won in the traditional model. This reflects that the new model considering the change of population change gives better realistic performance than the traditional one.

Sea Buckthorn (Hippophae rhamnoides L.) Leaf Extracts Protect Neuronal PC-12 Cells from Oxidative Stress

  • Cho, Chi Heung;Jang, Holim;Lee, Migi;Kang, Hee;Heo, Ho Jin;Kim, Dae-Ok
    • Journal of Microbiology and Biotechnology
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    • v.27 no.7
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    • pp.1257-1265
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    • 2017
  • The present study was carried out to investigate the antioxidative and neuroprotective effects of sea buckthorn (Hippophae rhamnoides L.) leaves (SBL) harvested at different times. Reversed-phase high-performance liquid chromatography analysis revealed five major phenolic compounds: ellagic acid, gallic acid, isorhamnetin, kaempferol, and quercetin. SBL harvested in August had the highest total phenolic and flavonoid contents and antioxidant capacity. Treatment of neuronal PC-12 cells with the ethyl acetate fraction of SBL harvested in August increased their viability and membrane integrity and reduced intracellular oxidative stress in a dose-dependent manner. The relative populations of both early and late apoptotic PC-12 cells were decreased by treatment with the SBL ethyl acetate fraction, based on flow cytometry analysis using annexin V-FITC/PI staining. These findings suggest that SBL can serve as a good source of antioxidants and medicinal agents that attenuate oxidative stress.

Washout resistance of fast-setting pozzolan cement under various root canal irrigants

  • Jang, Ga-Yeon;Park, Su-Jung;Heo, Seok-Mo;Yu, Mi-Kyung;Lee, Kwang-Won;Min, Kyung-San
    • Restorative Dentistry and Endodontics
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    • v.38 no.4
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    • pp.248-252
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    • 2013
  • Objectives: Fast-setting pozzolan cement (Endocem, Maruchi) was recently developed. The aim of this study was to investigate the effects of various root canal irrigants on the washout of Endocem in comparison to the previously marketed mineral trioxide aggregate (ProRoot; Dentsply) in a furcal perforation model. Materials and Methods: ProRoot and Endocem were placed into acrylic molds on moist Oasis. Each mold was then immediately exposed to either physiologic saline, 2.5% sodium hypochlorite (NaOCl), or 2% chlorhexidine (CHX) under gentle shaking for five minutes. Washout testing was performed by scoring scanning electron microscope (SEM) images. Results: Endocem exhibited higher washout resistance compared to ProRoot, especially in the NaOCl group. Conclusions: These results suggest that Endocem can be considered a useful repair material for furcal perforation, especially in a single-visit scenario.