• Title/Summary/Keyword: Carbon-11

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Preparation and Application of Functional Carbon Whisker Membrane for Separation Process

  • Bae, Sang-Dae;Son, Hee-Jong;Jung, Chul-Woo
    • Journal of Environmental Science International
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    • v.17 no.11
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    • pp.1235-1241
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    • 2008
  • Membrane separation is extensively used for water/wastewater treatment because of its efficiency separation processes. However, particles in the feed water can deposit and accumulate on the membrane surface to created cake layer. As a consequence, the selectivity of the membrane and flux through the membrane are decreased, which is called fouling/blocking phenomenon. In order to solve fouling problem, we developed a novel membrane named Carbon Whisker Membrane (CWM) which contains vapor-grown carbon fibers/whiskers on the surface of the membrane and a layer of carbon film coated on the ceramic substrate. We firstly employed polymethyl methacrylate (PMMA) as a testing material to investigate the fouling mechanism. The results suggested that Carbon Whiskers on the surface of the membrane can prevent the directly contact between the membrane body and particles so that the fouling/blocking could not occurred easily compared to the membrane without carbon whiskers. We also researched the relationship with the diameter, density of carbon whisker on the membrane surface and total flux of solutions. Finally, we will be able to control the diameter and density of carbon whiskers on the membrane and existence of carbon whiskers on the membrane, it is important factor, might be prevent fouling/blocking in the water treatment.

Environmental Performance, Carbon Emission Disclosure, and Carbon Emission Intensity on Cost of Equity Capital: An Empirical Study in Indonesia

  • MARSELITA, Octa;Lindrianasari, Lindrianasari;ALVIA, Liza;EVANA, Einde
    • The Journal of Industrial Distribution & Business
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    • v.12 no.11
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    • pp.9-16
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    • 2021
  • Purpose: Carbon emissions have now become a major concern around the world, especially for the government and private sector. Unfortunately, in Indonesia, disclosure related to company carbon emissions is still done voluntarily. This research aims to provide empirical evidence on the effect of environmental performance, carbon emission disclosure, and carbon emission intensity on the cost of equity capital. Research design, data, and methodology: This research uses secondary data with a sample consisting of Indonesia companies that are sensitive to the environment and listed on the Indonesia Stock Exchange in 2017-2019. The analytical tool used in this research was multiple regression models. Result: The study found a carbon emission disclosure had a significant positive effect on the cost of equity capital. Carbon emission intensity and company size had a significant negative effect on the cost of equity capital. Meanwhile, environmental performance did not have a significant effect on the cost of equity capital. Conclusion: Therefore, the results of this research are expected to provide feedback to the company's stakeholders that environmental performance and carbon emissions are some of the points seen by investors in making investment decisions.

Potential of Activated Carbon Derived from Local Common Reed in the Refining of Raw Cane Sugar

  • D-Abdullah, Ibrahim;Girgis, Badie S.;Tmerek, Yassin M.;Badawy, Elsaid H.
    • Carbon letters
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    • v.11 no.3
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    • pp.192-200
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    • 2010
  • Common reed (Fragmites australis), a local invasive grass, was investigated as a possible feedstock for the production of activated carbon. Dried crushed stems were subjected to impregnation with phosphoric acid (30, 40 and 50%) followed by pyrolysis at $400{\sim}500^{\circ}C$ with final washing and drying. Obtained carbons were characterized by determining: carbon yield, ash content, slurry pH, textural properties and capacity to remove color bodies from factory-grade sugar liquor. Produced carbons possessed surface area up to 700 $m^2/g$, total pore volumes up to 0.37 $cm^3/g$, and proved to be microporous in nature. Decolorization of hot sugar liquor at $80^{\circ}C$ showed degrees of color removal of 60 up to 77% from initial color of 1100~1300 ICU, at a carbon dose of 1.0 g/100 ml liquor. No correlation seems to hold between synthesis conditions and % R but depends on the degree of microporosity. A commercial activated carbon N showed a comparative better color removal capacity of 91%. Common reed proved to be a viable carbon precursor for production of good adsorbing carbon suitable for decolorization in the sugar industry, as well as in other environmental remediation processes.

Properties of Carbon Pastes Prepared with Mixing Ratios of Nano Carbon and Graphite Flakes

  • Kim, Kwangbae;Song, Ohsung
    • Korean Journal of Materials Research
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    • v.28 no.11
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    • pp.615-619
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    • 2018
  • To produce carbon electrodes for use in perovskite solar cells, electrode samples are prepared by mixing various weight ratios of 35 nm nano carbon(NC) and $1{\mu}m$ graphite flakes(GF), GF/(NC+GF) = 0, 0.5, 0.7, and 1, in chlorobenzene(CB) solvent with a $ZrO_2$ binder. The carbon electrodes are fabricated as glass/FTO/carbon electrode devices for microstructure characterization using transmission electron microscopy, optical microscopy, and a field emission scanning electron microscopy. The electrical characterization is performed with a four-point probe and a multi tester. The microstructure characterization shows that an electrode with excellent attachment to the substrate and no surface cracks at weight ratios above 0.5. The electrical characterization results show that the sheet resistance is <$70{\Omega}/sq$ and the interface resistance is <$70{\Omega}$ at weight ratios of 0.5 and 0.7. Therefore, a carbon paste electrode with microstructure and electrical properties similar to those of commercial carbon electrodes is proposed with an appropriate mixing ratio of NC and GF containing a CB solvent and $ZrO_2$.

Consecutive automated production of carbon-11 labeled radiopharmaceuticals by sharing 11C-methylation reagent from one 11C-synthetic module

  • Park, Hyun Sik;Lee, Hong Jin;An, Hyun Ho;Moon, Byung Seok;Lee, Byung Chul;Kim, Sang Eun
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.2 no.2
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    • pp.123-131
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    • 2016
  • Increasing clinical demand for carbon-11 labeled radiopharmaceuticals has triggered technological advances in fields of radiochemistry and automated modules. Even though carbon-11 has a short half-life ($t_{1/2}=20.4min$), the consecutive second production of carbon-11 labeled radiopharmaceutical in one $^{11}C$-synthetic module should be delayed at least over 4 h to avoid the high radiation exposure. We herein aimed to produce two different carbon-11 labeled radiopharmaceuticals ([$^{11}C$]PIB and [$^{11}C$]methionine) by sharing of [$^{11}C$]methylation source in one $^{11}C$-synthetic module. The synthesis of $^{11}C$-labeling reagents ($[^{11}C]CH_3I$ or $[^{11}C]CH_3OTf$) is fully automated using the commercial TRACERlab $FX_{C-pro}$ module and is readily adaptable to $^{11}C$-labeling reactor for [$^{11}C$]PIB as well as another $^{11}C$-labeling apparatus for [$^{11}C$]methionine via the three-way valve. After completing the [$^{11}C$]PIB production, the re-synthesized $[^{11}C]CH_3I$ was passed through the three-way valve connected the polyetheretherketone (PEEK) line and loaded into the C18 Sep-Pak cartridge including the methionine precursor. The labeled product [^${11}C$]methionine was purified by a simple cartridge separation and reformulated into saline. The radiochemical yield of [$^{11}C$]PIB and [$^{11}C$]methionine were $5.3{\pm}0.6%$ and $18.7{\pm}0.8%$ (n.d.c.), respectively, with over 97% of radiochemical purity. The specific activity of [$^{11}C$]PIB was over $110GBq/{\mu}mol$. Total production time of two radiopharmaceuticals needs about 2 h from $1^{st}$ beam irradiation including quality control tests. Final [$^{11}C$]PIB and [$^{11}C$]methionine were satisfied all quality control test standards.

Dehydrogenation of Ethylbenzene with Carbon Dioxide as Soft Oxidant over Supported Vanadium-Antimony Oxide Catalyst

  • Hong, Do-Young;Vislovskiy, Vladislav P.;Park, Sang-Eon;Park, Min-Seok;Yoo, Jin-S.;Chang, Jong-San
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1743-1748
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    • 2005
  • This work presents that carbon dioxide, which is a main contributor to the global warming effect, could be utilized as a selective oxidant in the oxidative dehydrogenation of ethylbenzene. The dehydrogenation of ethylbenzene over alumina-supported vanadium-antimony oxide catalyst has been studied under different atmospheres such as inert nitrogen, steam, oxygen or carbon dioxide as diluent or oxidant. Among them, the addition of carbon dioxide gave the highest styrene yield (up to 82%) and styrene selectivity (up to 97%) along with stable activity. Carbon dioxide could play a beneficial role of a selective oxidant in the improvement of the catalytic behavior through the oxidative pathway.