• Title/Summary/Keyword: CCl$_4$

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A Spectroscopic Study on Singlet Oxygen Production from Different Reaction Paths Using Solid Inorganic Peroxides as Starting Materials

  • Li, Qingwei;Chen, Fang;Zhao, Weili;Xu, Mingxiu;Fang, Benjie;Zhang, Yuelong;Duo, Liping;Jin, Yuqi;Sang, Fengting
    • Bulletin of the Korean Chemical Society
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    • v.28 no.10
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    • pp.1656-1660
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    • 2007
  • Using solid inorganic peroxides (including Li2O2, Na2O2, SrO2 and BaO2) as starting materials, three reaction paths for singlet oxygen (1O2) production were developed and studied. Their 1O2 emission spectra in the near- IR region and visible region from these reaction paths were simultaneously recorded by a near-IR sensitive Optical Multichannel Analyzer and a visible sensitive Optical Spectrum Analyzer, respectively. The comparison of their 1O2 emission spectra indicated that: (1) in term of the efficiency for 1O2 production, the gasliquid- solid reaction path (in which Cl2 or HCl and H2O reacted with the solid inorganic peroxides suspension in CCl4) was prior to the gas-solid reaction path (in which Cl2 or HCl reacted with the solid inorganic peroxides suspension in CCl4), but was inferior to the gas-liquid reaction path (in which Cl2 or HCl reacted with the solid inorganic peroxides solution in H2O or D2O); (2) the alkali metal peroxides (such as Li2O2 and Na2O2) was prior to the alkaline earth metal peroxides (such as SrO2 and BaO2) as the solid reactants, and Cl2 was favorable than HCl as the gas reactant in efficiency for 1O2 production in these reaction paths.

Performance Analysis of Hybrid DS/SFH-CDMA MFSK Signal with CCI Canceller and Convolution Code Techniques in Mobile Communication Multipath Interference Channels (이동통신 다중 경로 간섭 채널에서 CCI Canceller와 컨벌루션 부호화 기법에 의한 하이브리드 DS / SFH-CDMA MFSK 신호의 성능 해석)

  • 임태길;강희조;이권현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.3
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    • pp.221-231
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    • 1997
  • This paper presents an analysis of a hybrid direct-sequence/slow frequency hopped code division multiple access(DS/SFH-CDMA) system employing noncoherent M-ary frequency shift keying(MFSK) modulation in a multiple m-distribution fading environment. Multipath interfer- ence(MPI) and multiuser interference(MUI) is taken into accout and the spectral efficiency is calculated for uncoded as well as simple channel coding systems. The predetection multipath CCI canceller in conjunction with convolution coding is employed for improving the bit error rate(BER) performance. The BER of noncoherent hybrid system is obtained using a Gaussian interference approximation. From the results, we know that the error performance more deteriorates as the depth of fading becomes deeper. The DS part of the modulation combats the multipath interference, whereas the FH part is a predetection against large multiuser interference. It is shown that, for the con- sidered types of a channel coding, the use of a predetection coding is still essential for obtained a satisfactory bit error performance. The results show that the capacity of the DS/SFG-CDMA MFSK communication system increases in proportion to the length of PN code sequence in the presence of AWGN and MUI. In m-distribution fading environment the capacity increases in proportion to the fading index. The capacity is increased and error performance is improved when the CCI Canceller and Convolution code technique are adopted, respectively. From the results, it is known that the error performance of $4\times10^{-2}$ by adopting Canceller technique. Also convolutional coding technique is the improvement of error performance attains about $10^{-5}$ in code rate 1/2.

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Immune-triggering effect of the foodborne parasite Kudoa septempunctata through the C-type lectin Mincle in HT29 cells

  • Shin, Ji-Hun;Yang, Jung-Pyo;Seo, Seung-Hwan;Kim, Sang-Gyun;Kim, Eun-Min;Ham, Do-Won;Shin, Eun-Hee
    • BMB Reports
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    • v.53 no.9
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    • pp.478-483
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    • 2020
  • Kudoa septempunctata is a myxozoan parasite that causes food poisoning in individuals consuming olive flounder. The present study aimed to investigate the currently insufficiently elucidated early molecular mechanisms of inflammatory responses in the intestine owing to parasite ingestion. After Kudoa spores were isolated from olive flounder, HT29 cells were exposed to spores identified to be alive using SYTO-9 and propidium iodide staining or to antigens of Kudoa spores (KsAg). IL-1β, IL-8, TNF-α and NFKB1 expression and NF-κB activation were assessed using real-time PCR, cytokine array and western blotting. The immunofluorescence of FITC-conjugated lectins, results of ligand binding assays using Mincle-Fc and IgG-Fc, CLEC4E expressions in response to KsAg stimulation, and Mincle-dependent NF-κB activation were assessed to clarify the early immune-triggering mechanism. Inflammatory cytokines (IL-1β, GM-CSF and TNF-α), chemokines (IL-8, CCL2, CCL5 and CXCL1) and NF-κB activation (pNF-κB/NF-κB) in HT29 cells increased following stimulation by KsAg. The immunofluorescence results of spores and lectins (concanavalin A and wheat germ agglutinin) suggested the importance of Mincle in molecular recognition between Kudoa spores and intestinal cells. Practically, data for Mincle-Fc and KsAg binding affinity, CLEC4E mRNA expression, Mincle immunofluorescence staining and hMincle-dependent NF-κB activation demonstrated the involvement of Mincle in the early immune-triggering mechanism. The present study newly elucidated that the molecular recognition and immune-triggering mechanism of K. septempunctata are associated with Mincle on human intestinal epithelial cells.

Hepatoprotective effect of Paeoniae radix via Nrf2 activation (Nrf2 활성화(活性化)를 통한 작약(芍藥)의 간보호효과(肝保護效果))

  • Lee, Soo Hwan;Jung, Ji Yun;Park, Sang Mi;Jegal, Kyung Hwan;Byun, Sung Hui;Cho, Il Je;Kim, Sang Chan;Kim, Kwang Joong;Kim, Young Woo
    • The Korea Journal of Herbology
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    • v.31 no.1
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    • pp.33-40
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    • 2016
  • Objectives : Liver is one of the largest organs in the human, and has a function of detoxification and energy sensing to prevent severe disease. Paeoniae radix has been used to treat a variety of liver diseases such as hepatitis and chronic hepatic failure. Although P. radix has been used as an medicinal herb for a long time, the effects of P. radix on severe oxidative stress and its action mechanism on the liver was not clearly verified.Methods : This study investigated the protective effects of P. radix extract (PRE), and the underlying mechanism of its action in the liver. tert-butyl hydroperoxide (t-BHP) and carbon tetrachlroride (CCl4) were used to induce oxidative stress in the HepG2 hepatocyte cell line and Sprague-Dawley rats, respectively.Results : t-BHP significantly induced cell death and ROS production in HepG2 cell, as indicated by MTT and FACS analysis. However, pretreatment of PRE inhibited a decrease in cell viability and H2O2 production in the HepG2 cells. PRE also blocked the ability of t-BHP to damage in mitochondrial membrane transition. More importantly, PRE induced Nrf2 activation and antioxidant Phase II enzyme, which may have a role in the effects of PRE. In mice, PRE inhibited the liver damage induced by CCl4.Conclusions : PRE inhibited oxidative stress and hepatic damages as mediated with Nrf2 activation. This study unveil, in part, the effect and mechanism of old medicinal herb, P. radix.

A Study on the Leaching of Heavy Metals by Municipal Solid Waste Landfill Leachate (폐기물 매립지 침출수에 의한 중금속 용출에 관한 연구)

  • Jung, Jong-Gwan;Jang, Won;Park, Young-Suk
    • Journal of Environmental Impact Assessment
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    • v.6 no.1
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    • pp.105-110
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    • 1997
  • Sanitary landfill is a general method as a final disposal of municipal solid waste(MSW), therefore leachate characteristics are very various as lime goes by because of highly concentrated organic acids are contained non biodegradable COD. So it is hard to abide by the mandatory standards of discharge eventhough applying the physicochemical and biological processes to treat the leachate. The process of treating leachate are determined by the degree of removal and components, but they are highly contained organic materials. It is a removal method to use jointly with the physicochemical process if the hard and fast rule is needed. The critical components of material are COD, ammonia, salts and heavy metals in the case of treating biologically. Biological process is to use metabolism of microorganism, therefore it is a desirable condition which heavy metals are not contained, because they acting as an inhibitor of enzyme. Of these are contained, organic decomposition and synthetic function of microorganisms decrease significantly. Consequently, this research paper lays emphasis on the concentration of heavy metals in leachate and for the purpose of forecasting the factors which are affecting the leaching of metalic waste in some degree, experimented the various reacting conditions. 1. When the concentration of heavy metals in leachate is in comparison with the level eluted after reaction, at pH 7.9 the result of reaction for PCB to CCL scrap showed that Zn, Mn, Cu was more eluted 11.6 times, 340.3 times, and 2,705.5 times respectively than the leachate undiluted solution. 2. At the condition of strong acid pH 4.7, the concentration of heavy metals in EM undiluted solution showed that Zn, Mn, Cu was more eluted 26.5 times, 147.3 times, and 3,656.3 times respectively than leachate undiluted solution. 3. When the ratio leachate to EM was 50 vs 50(V/V%), Mn was more eluted 198.7 times than leachate undiluted solution, but Zn and Cu do not show the meaningful results. 4. The color of landfill leachate was black-brown. And fulvic acid that is main ingredient of NBD COD contained, oxygen of 44~50%. For that reason, I estimated that the level of Zn, Mn, Cu was higher than the case of leachate. 5. COD of leachate from general landfill is difficult to remove. Because the solution of heavy metals is improved by the character of leachate(pH & ingredient of oxygen etc.) hence the Mn, Cu, Zn act as disturbing factor, the biochemical treatment is hard. Therefore the type of PCB & CCL scrap, iron, aluminum contained metals need to previously separate from general wastes as much as possible.

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Study on Destruction of Chlorinated Organic Compounds in a Two Stage Molten Carbonate Oxidation System (2단 용융탄산염산화시스템에서 염소유기화합물 분해에 관한 연구)

  • Eun, Hee-Chul;Yang, Hee-Chul;Cho, Yung-Zun;Lee, Han-Soo
    • Korean Chemical Engineering Research
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    • v.46 no.6
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    • pp.1148-1152
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    • 2008
  • Molten carbonate oxidation (MCO) is one of the promising alternative technologies for the treatment of the chlorinated organic compounds because it is capable of trapping chlorine during a destruction of them. In this study, destructions of chlorinated organic compounds ($C_6H_5Cl$, $C_2HCl_3$ and $CCl_4$) and an insulated oil containing PCBs were performed by using the two stage molten carbonate oxidation system. MCO reactor temperature largely affected the destruction of the chlorinated organic compounds. Destruction of the chlorinated organics very efficient in the primary MCO reactor however a significant amount of CO was emitted from the MCO system. This CO emission was gradually decreased by an increase in the primary reactor temperature and oxidizing air feed rate. The HCl emission from the MCO system was below 7 ppm regardless of tested conditions. The chlorine collection efficiencies were in the range of 99.95-99.99%. The destruction of PCBs in the insulated oil was efficient at a temperature above $900^{\circ}C$ and overall destruction efficiency of them was determined as over 99.9999%.

Heterogeneous Photocatalytic Decomposition of Organics in Water Phase ($TiO_2$ 광촉매를 활용한 수용액 내의 유기물질의 광분해반응)

  • Lee, Tai-K.;Kim, Dong-H.;Kim, Kyung-N.;Auh, P. Chung-Moo
    • Solar Energy
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    • v.15 no.2
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    • pp.65-75
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    • 1995
  • We have summarised some important aspects of our recent basic and applied studies in the area of photocatalytic detoxifcation with Degussa P25 titanium dioxide($TiO_2$) being the photocatalyst. Heterogeneousphotocatalytic decompositions of two components such as TCE-chloroform, TCE-phenol and TCE-benzene as well as single component organic, TCE, chloroform and $CCl_4$ were carried out to investigate the effect of additional compound on the TCE decomposition rate. In laboratory experiments, the optimum flow rate of TCE solution was $200cm^3/min$ with annular photoreactor in the presence of 0.1 wt% $TiO_2$ powder under illumination. It was observed that the second compound such as $CHCl_3$, phenol and benzene has a negative effect on the TCE decomposition rate. Result presented that TCE decomposition ratio was increased at low pH in the TCE-phenol two component solution. It could be shown that the photocatalytic reactor exhibits technical feasibility of detoxifying the multicomponent under proper experimental conditions.

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A Study on Methods of Implementation for the NRF Open Access Policy (한국연구재단 오픈액세스 정책 실행방안 연구)

  • Joung, KyoungHee;Lee, Jae Yun;Chung, EunKyung;Choi, Sanghee
    • Journal of the Korean Society for information Management
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    • v.37 no.4
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    • pp.255-286
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    • 2020
  • This study aims to identify the methods of implementation for the 'National Research Foundation of Korea Open Access 2021(Plan)'. This study covers the methods of implementation in the three following core items: 1) developing the details on the amount, method, and procedures of APC support; 2) proposing methods for facilitating the transition of domestic Korean academic journals to open access journals; and 3) developing methods of entrusting papers to open access repositories. APC support should be guaranteed at a reasonable level. The average or median of APC values for the previous three years will be applied to set the upper limit for support each year. APC support will be provided when the paper is published to open access journals or transitioning journals to open access. Hybrid journals or dual access journals are not included. Support for open access publishing of academic journals in Korea during the transition period will be available for open access journals that have registered for CCL in KJCI or journals that have submitted their application for transitioning to open access. Publishing in hybrid, dual access or subscription-based journals must be accompanied by items related to copyright such as embargo. Research results will be used for the detailed implementation plan of 'NRF OA2021 (Plan)'. They will serve as the base data for the rapid, stable, and sustainable implementation of open access policy in NRF, addressing the Korean domestic academic journal publishing environment and the field of international academic communication.

A Case Study on the Converting Journals to Open Access in the field of Library and Information Science and Archival Science in Korea (국내 문헌정보학 및 기록학 분야 학술지 오픈액세스 출판 전환 사례 연구)

  • Kyoung Hee Joung;Jae Yun Lee
    • Journal of the Korean Society for Library and Information Science
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    • v.57 no.2
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    • pp.271-291
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    • 2023
  • The purpose of this study is to analyze the current status and effects of open access conversion of journals from 7 societies that participated in the "Open Access Publication Declaration Academic Societies in the Field of Library and Information Science", and to identify problems and suggest improvement directions. To this end, the study analyzed the current status based on the elements presented in the "Roadmap for Open Access Publishing Conversion of the Library and Information Science Journals in Korea" and analyzed citation rates. The following problems were identified. First, some journals were not applying CCL or were unable to register it accurately with KJCI, and none of the 7 journals were registered with DOAJ. Second, the newly used journal platforms had not yet registered all previous issues after the conversion. Third, there was a tendency for the article processing charges to be partially increased, and there was also a tendency for editorial staff expenses to increase. Fourth, citation indexes after conversion were lower for both journals compared to the previous 4-5 years. This study proposes that joint publication of journals is necessary to solve practical problems jointly with societies while promoting economies of scale and suggests the need for further development of a roadmap.

A Pre-Selection of Candidate Units Using Accentual Characteristic In a Unit Selection Based Japanese TTS System (일본어 악센트 특징을 이용한 합성단위 선택 기반 일본어 TTS의 후보 합성단위의 사전선택 방법)

  • Na, Deok-Su;Min, So-Yeon;Lee, Kwang-Hyoung;Lee, Jong-Seok;Bae, Myung-Jin
    • The Journal of the Acoustical Society of Korea
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    • v.26 no.4
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    • pp.159-165
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    • 2007
  • In this paper, we propose a new pre-selection of candidate units that is suitable for the unit selection based Japanese TTS system. General pre-selection method performed by calculating a context-dependent cost within IP (Intonation Phrase). Different from other languages, however. Japanese has an accent represented as the height of a relative pitch, and several words form a single accentual phrase. Also. the prosody in Japanese changes in accentual phrase units. By reflecting such prosodic change in pre-selection. the qualify of synthesized speech can be improved. Furthermore, by calculating a context-dependent cost within accentual phrase, synthesis speed can be improved than calculating within intonation phrase. The proposed method defines AP. analyzes AP in context and performs pre-selection using accentual phrase matching which calculates CCL (connected context length) of the Phoneme's candidates that should be synthesized in each accentual phrase. The baseline system used in the proposed method is VoiceText, which is a synthesizer of Voiceware. Evaluations were made on perceptual error (intonation error, concatenation mismatch error) and synthesis time. Experimental result showed that the proposed method improved the qualify of synthesized speech. as well as shortened the synthesis time.