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        검색결과 614

        463.
        1985.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The transesterification reaction between ethanolamine and methyl-methacrylate was kinetically investigated in the presence of various metal acetate catalysts at 110℃. The transesterification was found to obey first-order kinetice with respect to the concentration of ethanolamine and methyl-methacrylate, respectively. By the Arrhenius plot, the activation energy has been calculated as 11.9 Kcal with lead acetate catalyst, 14.7 Kcal without catalyst. The reactivities has highest value where the electronegativity and instability constant (Kij) values for the metal acetate catalysts are about 1.6.
        4,000원
        464.
        1985.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The transesterification reaction between diethanolamine and dimethylphthalate was kinetically investigated in the presence of various metal acetate catalysts at 130℃. The reaction was followed by the measurement of distilled methanol from the reaction vessel. The transesterification was found to obey first-order kinetics with respect to the concentration of diethanolamine and dimethylphthalate and catalyst, respectively. The reactivities has highest value where the electronegativity and instability constand (Kij) values for the metal acetate catalysts are about 1.6.
        4,000원
        465.
        1970.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        수도품종명 도열병 저항성 차이와 도체내 성분과의 관계를 구명코저 저항성 품종, 중간정도 품종, 감수성인 품종의 실소 및 당 함량을 비교한 결과를 요약하면 다음과 같다. 1) 전질소, 전당 함량은 저항성인 품종이 감수성인 품종에 비해 전질소는 적고 전당은 많았다. 따라서 C/N 률은 저항성 품종이 감수성인 품종에 비해 높았다. 2) Free amino acid에 있어서는 저항성인 품종이 감수성인 품종에 비해 Glutamine, Valine 그리고 Leucine 과 Iso-leucine함량이 많았다. 3) 각종당액에서 전분합성은 저항성인 품종이 감수성인 품종에 비해 Fructose, Glucose에서는 높았고 Sucrose에서는 낮았으나 Indica type로 저항성인 Zenith에서는 오히려 전분합성이 감수성인 다다조 보다 떨어졌다. 4) 질소비료를 증시하면 전질소함량은 보비보다 증가하는데 그 증가율은 저항성인 품종에서 낮은 경향이었다. 전당은 분벽초기에 감소되며 그 감소율은 저항성인 품종이 더 떨어졌고 분벽최성기에는 오히려 증가하였는데 그 증가율은 저항성인 품종이 높은 경향이었다.
        4,000원
        467.
        2021.01 KCI 등재 서비스 종료(열람 제한)
        The purposes of this study were to evaluate the removal characteristics of COD, Ni, and P and to derive appropriate operating conditions for the plating wastewater according to NaOCl reaction time and pH operating conditions in the BPC unit process during the plating wastewater treatment process. As a results of evaluating the removal characteristics for raw wastewater by each BPC unit process, the removal efficiencies of COD, Ni and P in BPC 1-1 unit process were 72.8%, 99.1%, and 100.0%. Therefore, the proper reaction time of NaOCl was derived as 21.1 minutes. In order to maintain the +800 mV ORP and the reaction time of 20 minutes, the temporary injection and continuous injection of NaOCl in the BPC unit process were 13.7 mL and 18.7 mL, respectively. It was found that the temporary injection method of NaOCl reduced the chemical cost by 36.5% compared to the continuous injection method. Also, Ni showed the highest removal efficiency of 97.8% at pH 10.5. On the other hand, P showed a removal efficiency of 57.4% at pH 10.0.
        468.
        2020.05 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The paper examines the reaction of the Z-Vietnam generation to online TV advertising (TVC), which elements of online TV advertising has a positive influence, which factors do not affect or negatively affect their consumption decisions for the advertised goods. Data for the study was collected from 300 Vietnam’s Generation Z in Ho Chi Minh City through live interviews or questionnaires through Google Docs Forms, with over 30 questions. The six basic factors that influence the reactions of Generation Z consumers are information, entertainment, irritation, credibility, interaction, and advertising value. The research results show that, due to the influence of social media and generational characteristics, most consumers of the Generation Z in Vietnam have a favorable attitude towards online TV advertising, and they appreciate this form of advertising. Information element, irritation, credibility and entertainment have a strong and positive impact on TVC. The other two factors are advertising value and interaction, which does not significantly affect the reaction of this generation. This study needs to be checked and reviewed by subsequent studies on a larger scale and in a wider scope because the study only conducted random sampling on a small scale, did not meet the requirements for representation and generality.
        469.
        2020.04 KCI 등재 서비스 종료(열람 제한)
        To increase electrolysis performance, the applicability of seawater to the iron-fed electro-Fenton process was considered. Three kinds of graphite electrodes (activated carbon fiber-ACF, carbon felt, graphite) and dimensionally stable anode (DSA) electrode were used to select a cathode having excellent hydrogen peroxide generation and organic decomposition ability. The concentration of hydrogen peroxide produced by ACF was 11.2 mg/L and those of DSA, graphite, and carbon felt cathodes were 12.9 ~ 13.9 mg/L. In consideration of durability, the DSA electrode was selected as the cathode. The optimum current density was found to be 0.11 A/cm2, the optimal Fe2+ dose was 10 mg/L, and the optimal ratio of Fe2+ dose and hydrogen peroxide was determined to be 1:1. The optimum air supply for hydrogen peroxide production and Rhodamine B (RhB) degradation was determined to be 1 L/min. The electro-Fenton process of adding iron salt to the electrolysis reaction may be shown to be more advantageous for RhB degradation than when using iron electrode to produce hydrogen peroxide and iron ion, or electro-Fenton reaction with DSA electrode after generating iron ions using an iron electrode.
        470.
        2019.10 KCI 등재 서비스 종료(열람 제한)
        본 연구에서 서로 다른 양성자 에너지를 사용하여 핵반응에 의해 생성된 감마선의 차이를 통해 고에너 지 양성자 Pb(p, nx) 핵반응에서 생성된 동위원소를 식별하는 방법을 제안했다. 한국원자력연구원의 100-M eV 양성자 선형 가속기에서 생성된 고에너지 양성자를 이용하여 실험을 수행 하였다. 양성자 핵반응을 통해 생성된 다양한 핵종에 의해 생성된 감마선은 HPGe 검출기로 구성된 감마선 분광법 시스템을 사용하여 측정되었습니다. 감마선 표준선원은 감마선 검출기의 정확한 에너지교정 및 효율측정을 위해 사용되었습 니다. 제안한 방법을 위하여 동일한 천연 납 시료에 서로 다른 100 및 60 MeV 양성자 에너지빔을 사용하였다. 이 방법은 동일한 시료에서 발생되는 감마선들을 서로 비교함으로써 생성된 핵종들을 확인하는데 매우 효과적임을 알 수 있었다. 이 연구의 결과는 향후 다른 양성자 핵반응 결과를 얻는데도 매우 효과적으로 적용될 것이라 생각된다.
        471.
        2019.07 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to biological treatment of high salinity wastewater using Aerobic Granular Sludge (AGS). In laboratory scale’s experiments research was performed using a sequencing batch reactor, and evaluation of the denitrification reaction in accordance with the injection condition of salinity concentration, surface properties of microorganisms, and sludge precipitability was performed. The results showed that the salinity concentration increased up to 1.5%, and there was no significant difference in the nitrogen removal efficiency; however, it showed a tendency to decrease gradually from 2.0% onward. The specific denitrification rate (SDNR) was 0.052 0.134 mg NO3 --N/mg MLVSS (mixed liquor volatile suspended solid)·day. The MLVSS/MLSS (mixed liquor suspended solid) ratio decreased to 76.2%, and sludge volume index (SVI30) was finally lowered to 57 mL/g. Using an optical microscope, it was also observed that the initial size of the sludge was 0.2 mm, and finally it was formed to 0.8-1.0 mm. Therefore, salinity injection provides favorable conditions for the formation of an AGS, and it was possible to maintain stable granular sludge during long-term operation of the biological treatment system.
        472.
        2018.10 서비스 종료(열람 제한)
        Backgound : Inflammatory bowel diseases (IBDs) are chronic disorders that are characterized by intestinal epithelial inflammation and injury. Currently, the most employed therapies are antibiotics and anti-inflammatory drugs; however, the side effects limit long-term effectiveness. Methods and Results : We evaluated the impact of glucose-lysine Maillard reaction products (Glc-Lys MRPs) on colitis, induced in rats by an administration of 5% dextran sulfate sodium (DSS) in drinking water. Glc-Lys MRPs ameliorate DSS-induced colitis, as determined by a decrease in disease. index activity, colon weight/length ratio, nitric oxide levels in serum, recovery of body weight loss, colon length and serum lysozyme levels. Furthermore, Glc-Lys MRPs increase the glutathione content and the activity of glutathione peroxidase, superoxide dismutase and catalase, and inhibit lipid peroxidation and myeloperoxidase activity in colon tissues. In particular, Glc-Lys MRPs suppress the mRNA level of the inflammatory cytokines and nuclear factor-κB in colon tissues. Conclusion : This study suggests the potential of Glc-Lys MRPs in preventing or treating IBDs.
        473.
        2018.05 서비스 종료(열람 제한)
        The Stockholm Convention was adopted in Sweden in 2001 to protect human health and the environment, including Persistent Organic Pollutants Rotors, such as toxic and bioaccumulative. Currently, there are 28 kinds of materials. This prohibits and limits the production, use, and manufacture of the product. Korea is a party to the Convention and it is necessary to prepare management and treatment plan to cope with POPs trends. In the text, we have discussed HCBD materials. HCBD belongs to halogenated aliphatic unsaturated hydrocarbons. It is a toxic, organic mixture of bioaccumulation. A study on the treatment of waste containing HCBD substance, We decided to treat the waste containing HCBD thermally. So six samples were selected. Waste water treatment sludge, rubber plate, insecticide, tarpaulin, tire rubber, mixed sample. The tire rubber injected HCBD as a technical sample. HCBD analysis showed that 59.345 ~ 18,238.355 ug/kg was detected. For the thermal treatment, we analyzed element. As a result of thermogravimetric analysis, the weight change due to the decomposition of the material started at 200℃. The material decomposition was completed within 800℃. The thermal treatment was performed on a Lab-scale (1kg/hr). After exhaust gas analysis result, HCBD was detected at 0.01 to 0.09 ug/kg. The decomposition rate is estimated to be 99.848 ~ 99.999%. As a result of dioxin analysis in the exhaust gas, the highest concentration was found in the tarpaulins and the emission limit was exceeded. The concentrations of Cd, Pb, Cr, Cu, Ni and Zn in the residues were very low. Considering the decomposition rate of HCBD containing wastes, incineration treatment at 2 ton/hr or more is considered to be possible. And unintentional persistent organic pollutants such as dioxins in the exhaust gas. Therefore, it is considered safe to operate the incineration temperature at more than 1100℃.
        474.
        2018.05 서비스 종료(열람 제한)
        상업적으로 HTS (High Temperature Shift reaction) 반응에서 사용되는 Fe2O3/Cr2O3 촉매는 사용 후 6가 크롬 (Cr6+)의 침출에 따른 환경적/인체적 문제를 일으킬 수 있는 잠재성을 가지고 있어 친환경 크롬-프리 촉매개발을 위한 연구가 활발히 진행되고 있다. 본 연구에서는 크롬을 사용하지 않고 우수한 성능을 나타낼 수 있는 Fe/Al, Fe/Al/Cu, 그리고, Fe/Al/Ni 촉매를 제조하고 성능을 비교 평가하였다. 단계함침법으로 금속산화물(Cu와 Ni)과 알루미늄이 함유된 Fe계 촉매를 제조하고 촉매반응장치를 이용하여 각 촉매의 활성을 분석하였다. 그 결과 Fe/Al/Cu 촉매는 가혹한 조건(COconc. = 38.2%; 천연가스 대비 약 5.7 배 높은 CO 농도)에서도 탁월한 성능(XCO = 84.3% at 400 ℃)을 나타내었다. 이 결과는 Fe/Al/Cu 촉매의 강한 환원력과 활성종인 Fe3O4의 높은 열적 안정성에 기인한 것으로 확인되었다. 또한 강한 소결 저항성을 가진 Fe/Al/Cu 촉매는 400°C에서 100시간 동안 뚜렷한 비활성화를 보이지 않아 높은 안정성을 지닌 것으로 확인되었다.
        475.
        2018.05 서비스 종료(열람 제한)
        본 연구에서는 폐자원 합성가스를 이용한 고온전이반응용 Ce가 첨가된 Cu/γ-Al2O3 촉매의 물리 화학적 특성을 비교 분석하였다. 합성방법에 따른 촉매의 특성을 비교하기 위해 활성물질의 담지 순서를 변경하여 Ce/Cu/γ-Al2O3, Ce-Cu/γ-Al2O3, Cu/Ce/γ-Al2O3, Cu/γ-Al2O3 촉매를 제조하였다. 제조된 촉매 중 Ce/Cu/γ-Al2O3 촉매가 가장 높은 활성도 및 안전성을 나타냈다. 제조된 촉매의 물리-화학적 특성은 XRD, H2-TPR, XPS, Raman, Photoluminescence 등으로 분석하였다. 그리고 CO 전환율에서도 CeO2로 첨가된 모든 Cu/γ-Al2O3 촉매는 Cu/γ-Al2O3보다 높은 CO 전환율을 보였다. 이 연구결과는 CeO2의 첨가가 고온전이반응에서 Cu/γ-Al2O3 촉매의 성능을 향상 시킨 것을 나타낸다. 또한, Ce/Cu/γ-Al2O3 촉매의 높은 촉매 활성은 주로 고농도 산소저장능 및 환원된 Cu종과 관련이 있음을 알 수 있었다.
        476.
        2018.05 서비스 종료(열람 제한)
        본 연구에서는 폐기물가스화 후 생성되는 합성가스의 고순도 수소화를 위해 고온 수성가스전이반응(HT-WGS : High Temperature-Water Gas Shift) 반응용 특정 산화물(CeO2, ZrO2, TiO2 및 Al2O3)에 코발트를 담지한 촉매를 제조하고 그 산화환원특성을 비교 분석하였다. 특정 산화물에 Co를 함침법을 이용하여 담지하여 Co/CeO2, Co/ZrO2, Co/Al2O3, Co/TiO2 촉매를 각각 제조하였다. 제조된 Co 기반 촉매의 물리적 특성 분석은 BET 비표면적과 XRD 분석을 통해 수행하였고 CO 화학흡착과 H2-TPR 분석을 통해 산화환원 특성을 파악하고 동시에 물리-화학적 특성간의 상관관계를 해석하였다. H2-TPR 분석 및 CO 화학흡착 분석 결과, 코발트의 분산이 지지체 산화물의 환원성과 밀접한 상관관계를 가지고 있음을 알 수 있었다. 이 연구 결과는 Co/CeO2가 반응온도 350 ~ 550℃에서 활성 평가한 촉매 중에서 가장 우수한 활성을 나타내었다. 또한, Co/CeO2 촉매가 Co/ZrO2 및 Co/Al2O3 촉매보다 높은 촉매 활성 및 안정성을 나타내었다. Co/CeO2 촉매의 탁월한 활성 및 안정성은 지지체의 환원성과 높은 Co 금속의 분산에 기인하는 것으로 나타났다. 결과적으로 폐기물가스화로부터 생산된 합성가스를 고순도 수소로 전환하기 위한 HT-WGS 반응에서 Co/CeO2 촉매는 매우 유망한 촉매임을 알 수 있었다.
        477.
        2018.04 KCI 등재 서비스 종료(열람 제한)
        양성자가속기연구센터(KOMAC)의 100-MeV 양성자 선형가속기에서 생성된 고에너지 양성자를 사용하여 천연 텅스텐과 핵반응을 일으켰다. 핵반응을 통해 생성된 다양한 핵종으로 부터의 감마선은 HPGe 검출기 감마선 분광시스템을 사용하여 측정하였다. 감마선 표준선원은 에너지 교정 및 검출기의 효율 측정에 사용되었다. 측정된 스펙트럼에서 관찰된 감마선을 분석한 결과 방사성 핵종은 167Re, 178Re, 179Re, 180Re, 181Re, 182Re, 184Re, 172Ta, 174Ta, 178Ta, 182Ta, 184Ta, 175W, 176W, 177W 및 179W 으로 총 16 종류의 핵종이 생성되었다. 이 연구의 결과는 미래의 핵융합, 천체 물리학 및 핵의학 응용 분야에 적용될 것으로 생각된다.
        478.
        2018.03 KCI 등재 서비스 종료(열람 제한)
        Landfill gases (LFGs), which consists of sulfur compounds, odorous substances such as ammonia and amines, and volatile organic compounds (VOCs), is generated during the natural process of bacterial decomposition of organic material contained in municipal solid waste (MSW) landfills. The VOCs in the LFGs cannot be only decomposed easily into the soil after landfilling but they also can cause serious problems for the surrounding atmosphere, soil, and groundwater because of their toxicity. Moreover, VOCs have been identified as precursors of photochemical smog and they are toxic and carcinogenic chemicals. Furthermore, VOCs comprise a low rate of the emissions, but they can cause cancer. Therefore, it is important to evaluate the hazard causing by VOCs in LFGs. This study is aim to identify chemicals in LFGs and the hazardous evaluation by mixing between chemicals in LFGs. The selected landfill site in the study is located in Daejeon. Waste generation data were obtained from the Ministry of Environment (MOE) of South Korea. To evaluate the amount of the selected VOCs (47) among the primary disintegration models, LFGs generation model in LandGEM program was used. For the gas mixing reaction, a program called CRW 4.0 was introduced by the NOAA in the United States was used. As a result, the cumulative capacity of landfills in 2015 was estimated at 7,650,682 tons. Therefore, the total LFGs generation in 2015 was 7.717 × 107m³. Also the LFGs showed almost all the hazardous reactions with NOx and O3 in the atmosphere. As VOCs in LFGs mixed air emissions, we confirmed that toxic potential gases such as phosgene, hydrogen halides, halogenated organics, chlorinated amines and acidic fumes are generated.
        479.
        2018.02 KCI 등재 서비스 종료(열람 제한)
        Background: Angelica gigas, A. sinensis, and A. acutiloba are commercially important in the herbal medicine market, and among them, A. gigas has the highest economic value and price. However, their similar morphological traits are often used for fraud. Despite their importance in herbal medicine, recognition of the differences between Angelica species is currently inadequate. Methods and Results: A multiplex polymerase chain reaction (PCR) method was developed for direct detection and identification of A. gigas, A. sinensis, and A. acutiloba. The gene for the distinction of species was targeted at ITS in the nucleus and trnC-petN gene in chloroplasts. The optimized multiplex PCR in the present study utilized each Angelica species-specific primer pairs. Each primer pair yielded products of 229 base pairs (bp) for A. gigas, 53 bp for A. sinensis, 170 bp for A. acutiloba. Additionally non-specific PCR products were not detected in similar species by species-specific primers. Conclusions: In the present study, a multiplex-PCR assay, successfully assessed the authenticity of Angelica species (A. gigas, A. sinensis, and A. acutiloba). and whole genome amplification (WGA) was performed after DNA extraction to identify, the species in the product. The detection method of raw materials developed in the present study could be applied to herbal medicine and health functional food management.
        480.
        2018.01 KCI 등재 서비스 종료(열람 제한)
        In this study, a lab-scale experiment was conducted to derive the optimal torrefaction conditions for upscaling food waste torrefaction to generate solid fuel. Basic characteristic analyses (a proximate analysis, elemental analysis, calorific value and thermogravimetric analysis) were conducted and further used to develop experimental conditions during upscaling. Based on the characteristics analysis, the experiments were conducted by varying the heating rates by 5, 10 and 15oC/min, varying the torrefaction temperature from 200 to 550oC at an interval of 50oC and varying the torrefaction residence time from 0 to 50 minutes at an interval of 10 minutes. The heating rates were varied and only carried out for the combustion experiments of the torrefied product at a temperature range of 50 to 800oC. The results show that the optimal torrefaction temperature and residence time of food waste torrefaction were 250 ~ 350oC and 30 ~ 40 minutes, respectively.