• Title/Summary/Keyword: Active Carbon

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C$_2H_2$ chemisorption for characterization of carbon black active sites (카본블랙 활성점 연구를 위한 아세틸렌 화학흡착)

  • Lee, Sang-Yup;Kwak, Jung-Hun;Yoon, Ki-June
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.80-83
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    • 2007
  • In order to characterize the catalytically active sites on carbon black, acetylene chemisorption had been examined recently at 773 and 873 K by using a pulse technique. As the inject ion was repeated at 773 K, the adsorbed amount gradually decreased and eventually the adsorption did not occur any more. At 873 K a constant amount of $C_2H_2$ was consumed repeatedly after several injections. Good linear relationships were obtained between the methane decomposition rate at 1123 or 1173 K and the cumulative acetylene adsorption at 773 K or the constant acetylene consumption at 873 K. Reasonable models for the associative acetylene chemisorption at 773 K and the constant acetylene consumption at 873 K on the armchair face at the edges of graphene layers were proposed. The constant consumpt ion may be explained by the "$C_2H_2$-addition-hydrogen- abstract ion (CAHA)" mechanism.

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Effect of Organic Material, Active Carbon and Magnesium on the Growth of Zoysia koreana (잔디생육에 대한 유기물, 활성탄소 및 마그네슘의 효과)

  • Choi, Byung-Ju;Shim, Jai-Sung;Park, Hoon
    • Asian Journal of Turfgrass Science
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    • v.8 no.3
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    • pp.193-199
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    • 1994
  • Effect pf rape seed oil cake compast (OM) active carbon(C) compound fertilizer (NPK) and magnesium sulfate (Mg) application on Zoysia koreana growth by lysimeter of 50cm soil column filled with a low fertility loam. Effect on growth was in order of OM>OM . NPK interaction> NPK . active carbon and Mg were not effective OM . NPK interaction effect was negative on leaf width and root dry matter yield. OM and OM . NPK interaction were most effective on rhizome growth. Their effect did not change the ratio of growth rates between aerial part and rhizome but change that between aerial part and root. Leaf width was most sensitive to the treatments.

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Biosorption of Heavy-metal Ions by Waste Brown Seaweed and Their Derivatives (미역 폐기물 및 미역폐기물 유도체에 의한 중금속이온의 생물흡착)

  • 박권필;김태희;김영숙;차왕석;우명우
    • Journal of Environmental Science International
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    • v.10 no.2
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    • pp.153-158
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    • 2001
  • The biosorption abilities of different parts of waste brown seaweeds and their derivatives to remove heavy metals (Cd, Zn, Pb, Cu, Fe, Ni, Mn) from waste were evaluated. The two parts of waste brown seaweeds (Undaria pinnatifida) were stems and sporophyls, and the brown seaweed derivatives were alginic fibers, active carbon added alginate(AC-alginate) and dealginate. The abilities of the sporophyls to adsorb the heavy metal ions were higher than those of stems, and those of alginates were slightly higher than those of dealginate in single ion solution. With decreasing the size of biosorbents, the velocity and the amount of adsorption increased. The abilities of alginate to remove the heavy metal ions increased in multi-ion solutions by adding active carbon to alginate. The selectivity of these biosorbents(alginate, AC-alginate) to lead ion was highest and to manganese ion was lowest.

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Effects of Source and Mixing Ratio of Topsoil onPhysicoChemical Properties of Green (토양개량제 혼합비율이 Green Topsoil의 물리 화학성에 미치는 영향)

  • 박찬무;한동식;황규석;이용범
    • Asian Journal of Turfgrass Science
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    • v.5 no.2
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    • pp.59-68
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    • 1991
  • This experiment was carried out to investigate the mixing ratio of soil amending materials such as peat perlite, active carbon and zeolite for improvements of physiochemical properties of topsoil, of creeping bentgrass (Agrostis palustris var. Penncross). The results were as followed :1.Appropriate addition of soil improvement material was increased the soil porosity due to the decrease of bulk density. Over supplement of soil improvement material induced the decrease of infiltration of water into soil.2Content of organic matter was increased in treatment of peat and active carbon . Soil reaction was decreased in peat treatment, but increased in perlite, zeolite and active carbon. Exchangeable cation capacity was increased by the addition of all kinds of soil improvement materials used in this experiment.

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Recent advances in carbon-11 chemistry

  • Lu, Yingqing;Lee, Byung Chul;Kim, Sang Eun
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.2 no.1
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    • pp.9-16
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    • 2016
  • Carbon-11 is one of the most sensitive and desirable positron emission tomography radio-isotope, which offers the capacity to be incorporated, through a covalent bond, into biologically active molecules without altering their biological properties. Carbon-11 can be obtained from the cyclotron with two different chemical forms: $[^{11}C]CO_2$ and $[^{11}C]CH_4$. [$^{11}C$]Methyl iodide has been widely used as a highly reactive labelling precursor that can be applied to label carbon-11 with biologically active molecules via alkylation of N-, O-, or S-nucleophiles. A more recent and still challenging labeling method is transition metal mediated $^{11}C$-carbonylation. Advances in organic chemistry, radiochemistry and improved automated techniques greatly encourage researchers to develop more carbon-11 labelled radiotracers for molecular imaging studies. This mini-review will introduce a historical track of carbon-11 chemistry combining with examples and its role in near future.

Active Distribution System Planning Considering Battery Swapping Station for Low-carbon Objective using Immune Binary Firefly Algorithm

  • Shi, Ji-Ying;Li, Ya-Jing;Xue, Fei;Ling, Le-Tao;Liu, Wen-An;Yuan, Da-Ling;Yang, Ting
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.580-590
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    • 2018
  • Active distribution system (ADS) considering distributed generation (DG) and electric vehicle (EV) is an effective way to cut carbon emission and improve system benefits. ADS is an evolving, complex and uncertain system, thus comprehensive model and effective optimization algorithms are needed. Battery swapping station (BSS) for EV service is an essential type of flexible load (FL). This paper establishes ADS planning model considering BSS firstly for the minimization of total cost including feeder investment, operation and maintenance, net loss and carbon tax. Meanwhile, immune binary firefly algorithm (IBFA) is proposed to optimize ADS planning. Firefly algorithm (FA) is a novel intelligent algorithm with simple structure and good convergence. By involving biological immune system into FA, IBFA adjusts antibody population scale to increase diversity and global search capability. To validate proposed algorithm, IBFA is compared with particle swarm optimization (PSO) algorithm on IEEE 39-bus system. The results prove that IBFA performs better than PSO in global search and convergence in ADS planning.

Crystallization Behaviour of PP and Carbon Nanofibre Blends

  • Chatterjee, A.;Deopura, B.L.
    • Fibers and Polymers
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    • v.4 no.3
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    • pp.102-106
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    • 2003
  • Crystallization behaviour of blends of different MFI isotactic polypropylenes (PP), and blends of PP with carbon nanofibre have been investigated by DSC and polarizing optical microscope. Both higher MFI PP component and the carbon nanofibre in the blend influence the nucleation activity of the melt during non-isothermal crystallization. In presence of carbon nanofibre, the sherulitic growth rate is highly disturbed. The calculation of nucleation activity indicates that carbon nanofibres act as active substrate for heterogeneous nucleation.

Electrochemical characteristics of active carbon prepared by chemical activation for anode of lithium ion battery (이차전지 음극용 화학적 활성화법으로 제조된 활성탄의 전기화학적 특성)

  • Lee, Ho-Yong;Kim, Tae-Yeong;Lee, Jong-Dae
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.3
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    • pp.480-487
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    • 2015
  • In this study, several kinds of active carbons with high specific surface area and micro pore structure were prepared from the coconut shell charcoal using chemical activation method. The physical property of prepared active carbon was investigated by experimental variables such as activating chemical agents to char coal ratio, flow rate of inert gas and temperature. It was shown that chemical activation with KOH and NaOH was successfully able to make active carbons with high surface area of $1900{\sim}2500m^2/g$ and mean pore size of 1.85~2.32 nm. The coin cell using water-based binder in the electrolyte of LiPF6 dissolved in mixed organic solvents (EC:DMC:EMC=1:1:1 vol%) showed better capacity than that of oil-based binder. Also, it was found that the coin cell of water-based binder shows an improved cycling performance and coulombic efficiency.

Structure-Activity Relationships Study of Angiotensin Converting Enzyme Inhibitor Captopril Derivatives: Importance of Solution Moleculnr Dynamics Study (Angiotensin 변환 효소 억제제인 Captopril 유도체들의 구조와 활성관계 연구: 수용액상의 분자동력학적 연구의 중요성)

  • 지명환;윤창노;진창배;박종세
    • Biomolecules & Therapeutics
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    • v.2 no.1
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    • pp.34-38
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    • 1994
  • In order to investigate the structure-activity relationships of the stereoisomers of angiotensin converting enzyme inhibitors, captopril and its derivatives were selected as model compounds. In vitro enzymatic activities of them depend on the symmetry at the asymmetric carbons. Especially, the alanyl carbon should have the S configuration to be biologically active. But the demethylated captopril having the achiral carbon also shows the activity although it is less active than captopril. Seven stereoisomers of captopril and its derivatives were chosen and their acidic and ionic forms were used for molecular dynamics simulations. Four computer simulations were practiced for each model compound in order to obtain the good condition for simulation to explain the experimental structure-activity relationships. From the computer simulation results, relativistic movements of three well-known pharmacophoric sites, carboxylate carbon, carbonyl oxygen, and sulfur atoms, were analyzed. Good results were obtained from the aqueous solution molecular dynamics simulation with ionic forms of model compounds. Active model compounds have the pharmacophoric areas of 6.08 to 6.38 $\AA$$^2$and the similarity in the geometrical data. But inactive ones have the largely deviated values of 4.51 to 4.87 $\AA$$^2$from those of active ones.

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Effect of the Feeding Probiotics on the Performance and Meat Quality Characteristics of the Finishing Pigs (생균제, Illite, 활성탄 및 목초액의 첨가가 육성-비육돈의 육질 특성에 미치는 영향)

  • Kim, Hee-Yoon;Kim, Young-Yik
    • Food Science of Animal Resources
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    • v.27 no.1
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    • pp.73-79
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    • 2007
  • We investigated the effects of dietary supplements such as probiotics, illite, active carbon and hardwood vinegar on growth performance and meat quality characteristics in finishing pigs. One hundred fifty pigs ($Landrace{\times}Yorkshire{\times}Duroc$; $32.3{\pm}1.3 kg$ average initial body weight) were used for a 100 day experiment. Pigs were randomly placed into one of five experimented diet groups (control, 0.2% probiotics, 1.0% illite, 1.0% active carbon, and 1.0% hardwood vinegar) and were slaughtered at approximately 110 kg live weight. The addition of 1.0% active carbon and hardwood vinegar caused a decrease in free water while, WHC (water holding capacity) was higher compared with controls. Drip loss in hog flesh was decreased by feeding probiotics, illite, active carbon and hardwood vinegar. Cooking loss was decreased when hogs were fed hardwood vinegar. Lightness ($L^*$) and redness ($a^*$) were no difference between the all treatment groups, yellowness ($b^*$) was higher when feeding active carbon and hardwood vinegar by 1.0%. When hogs were fed hardwood vinegar, drip loss was decreased, and meat color was higher in sensory evaluation of fresh meat. In cooked hog meat, meat color and juiciness were higher in hogs fed hardwood vinegar. These results showed that supplementing hog diets with 1.0% hardwood vinegar may noticeably improve the meat quality of finishing hogs.