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Sample records for super-powdered activated carbon

  1. Influence of various Activated Carbon based Electrode Materials in the Performance of Super Capacitor

    Science.gov (United States)

    Ajay, K. M.; Dinesh, M. N.

    2018-02-01

    Various activated carbon based electrode materials with different surface areas was prepared on stainless steel based refillable super capacitor model using spin coating. Bio Synthesized Activated Carbon (BSAC), Activated Carbon (AC) and Graphite powder are chosen as electrode materials in this paper. Electrode materials prepared using binder solution which is 6% by wt. polyvinylidene difluoride, 94% by wt. dimethyl fluoride. 3M concentrated KOH solution is used as aqueous electrolyte with PVDF thin film as separator. It is tested for electrochemical characterizations and material characterizations. It is observed that the Specific capacitance of Graphite, Biosynthesized active carbon and Commercially available activated carbon are 16.1F g-1, 53.4F g-1 and 107.6F g-1 respectively at 5mV s-1 scan rate.

  2. Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.

    Science.gov (United States)

    Clack, Herek L

    2012-07-03

    The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions.

  3. Acid-base characteristics of powdered-activated-carbon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Reed, B.E. (West Virginia Univ., Morgantown (United States)); Jensen, J.N.; Matsumoto, M.R. (State Univ. of New York, Buffalo (United States))

    Adsorption of heavy metals onto activated carbon has been described using the surface-complex-formation (SCF) model, a chemical equilibrium model. The SCF model requires a knowledge of the amphoteric nature of activated carbon prior to metal adsorption modeling. In the past, a single-diprotic-acid-site model had been employed to describe the amphoteric nature of activated-carbon surfaces. During this study, the amphoteric nature of two powdered activated carbons were investigated, and a three-monoprotic site surface model was found to be a plausible alternative. The single-diprotic-acid-site and two-monoprotic-site models did not describe the acid-base behavior of the two carbons studied adequately. The two-diprotic site was acceptable for only one of the study carbons. The acid-base behavior of activated carbon surfaces seem to be best modeled as a series of weak monoprotic acids.

  4. USING POWDERED ACTIVATED CARBON: A CRITICAL REVIEW

    Science.gov (United States)

    Because the performance of powdered activated carbon (PAC) for uses other than taste and odor control is poorly documented, the purpose of this article is to critically review uses that have been reported (i.e., pesticides and herbicides, synthetic organic chemicals, and trihalom...

  5. MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON

    Science.gov (United States)

    The paper presents a mathematical model of total mercury removed from the flue gas at coal-fired plants equipped with powdered activated carbon (PAC) injection for Mercury control. The developed algorithms account for mercury removal by both existing equipment and an added PAC in...

  6. Characteristics of activated carbon resulted from pyrolysis of the oil palm fronds powder

    Science.gov (United States)

    Maulina, S.; Iriansyah, M.

    2018-02-01

    Activated carbon is the product of a charcoal impregnation process that has a higher absorption capacity and has more benefits than regular char. Therefore, this study aims to cultivate the powder of oil palm fronds into activated carbon that meets the requirements of Standard National Indonesia 06-3730-1995. To do so, the carbonization process of the powder of oil palm fronds was carried out using a pyrolysis reactor for 30 minutes at a temperature of 150 °C, 200 °C, and 250 °C in order to produce activated char. Then, the char was impregnated using Phosphoric Acid activator (H3PO4) for 24 hours. Characteristics of activated carbon indicate that the treatment of char by chemical activation of oil palm fronds powder has an effect on the properties of activated carbon. The activated carbons that has the highest absorption properties to Iodine (822.91 mg/g) were obtained from the impregnation process with 15% concentration of Phosphoric Acid (H3PO4) at pyrolysis temperature of 200 °C. Furthermore, the activation process resulted in activated carbon with water content of 8%, ash content of 4%, volatile matter 39%, and fixed carbon 75%, Iodine number 822.91 mg/g.

  7. The use of Powdered Activated Carbon in reducing the Doc in water treatment plants

    International Nuclear Information System (INIS)

    Nikravesh, S. H.; Etemad-Shahidi, A.; Razeghi, N.

    2003-01-01

    Today as the technology improves and the application of energy and chemicals enhances, the organic pollutants increases in surface waters in which waste waters are discharged into. In order to reduce water-born diseases, necessary actions should be taken to decrease the pollutants. Common methods of surface water treatment are not sufficient anymore. Therefore complementary methods like using activated carbon, aeration, oxidation and reverse osmosis should be used. In this paper the use of powdered activated carbon, Total organic carbon test and jar test in reducing the concentration of organic carbons in water treatment is investigated. Initial experimental results showed large errors in total organic carbon evaluation so dissolved organic carbon was measured instead. The results showed that using the powdered activated carbon in addition to conventional treatment method using ferric chloride, greatly reduces organic pollutants. Adding about 60 mg/lit of powdered activated carbon may reduce dissolved organic carbon up to 90% in optimum conditions. However, different factors like the quality of surface water, experimental errors, instrumental errors and tool errors can influence the experimental results

  8. APPLICATION OF POWDERY ACTIVATED CARBONS FOR REMOVAL IBUPROFEN FROM WATER

    Directory of Open Access Journals (Sweden)

    Alicja Puszkarewicz

    2017-07-01

    Full Text Available The paper presents results of studies on the use of adsorptive properties of selected powdered activated carbons (Norit SA Super and Carbopol MB5 for removal of ibuprofen from water. The tests were performed on non-flow conditions, series depending on the type and dose of powdered adsorbents. The research was carried out on a model solution of ibuprofen at initial concentration C0 = 20 mg/dm3, at 200 C. Froundlich and Langmuir adsorption isotherms were used. Lagergrene kinetic models (PFO and Ho (PSO were used to describe adsorption kinetics. Both carbons exhibited a higher affinity for the adsorbent at a pH above 7. The better adsorbent was the Norit SA Super, for which, the highest adsorption capacity q = 0.448 g/g was achieved with dose D = 35 mg/dm3. The effectiveness of adsorption (decrease of ibuprofen in water was 78%. Total removal of ibuprofen was obtained for a dose of carbon D = 200 mg/dm3. With respect to Carbopol, the highest adsorption capacity (q = 0.353 g / g was achieved at a dose of 30 mg / dm3, resulting in a 53% efficiency. Studies have shown that both tested powdered activated carbons have contributed to effective cleaning of aqueous solutions containing ibuprofen.

  9. Electrochemical properties of Super P carbon black as an anode active material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Gnanamuthu, RM.; Lee, Chang Woo

    2011-01-01

    Highlights: → A novel attempt of Super P carbon black as an anode active material for lithium-ion batteries. → The first discharge capacity was approximately 1256 mAh g -1 and at the end of 20th cycling the capacity was 610 mAh g -1 at 0.1 C rate. → Coulombic efficiency of Super P carbon black electrode was maintained about 84% at the end of cycling. - Abstract: A new approach to investigate upon the electrochemical properties of Super P carbon black anode material is attempted and compared with conventional mesophase pitch-based carbon fibers (MPCFs) anode material for lithium-ion batteries. The prepared Super P carbon black electrodes are characterized using transmission electron microscope (TEM). The assembled 2032-type coin cells are electrochemically characterized by ac impedance spectroscopic and cyclic voltammetric methods. The electrochemical performance of charge and discharge was analyzed using a battery cycler at 0.1 C rate and cut-off potentials of 1.20 and 0.01 V vs. Li/Li + . The electrochemical test illustrates that the discharge capacity corresponding to Li intercalation into the Super P carbon black electrode is higher and coulombic efficiency is maintained approximately 84% at the end of the 20th cycling at room temperature.

  10. Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products.

    Science.gov (United States)

    Crozier, Stephen J; Preston, Amy G; Hurst, Jeffrey W; Payne, Mark J; Mann, Julie; Hainly, Larry; Miller, Debra L

    2011-02-07

    Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g)), total polyphenol content (TP (mg/g)), and total flavanol content (TF (mg/g)). Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit".

  11. Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products

    Science.gov (United States)

    2011-01-01

    Background Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Results Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g)), total polyphenol content (TP (mg/g)), and total flavanol content (TF (mg/g)). Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Conclusions Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit". PMID:21299842

  12. Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products

    Directory of Open Access Journals (Sweden)

    Mann Julie

    2011-02-01

    Full Text Available Abstract Background Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Results Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g, total polyphenol content (TP (mg/g, and total flavanol content (TF (mg/g. Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Conclusions Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit".

  13. Investigation on the rapid degradation of congo red catalyzed by activated carbon powder under microwave irradiation

    International Nuclear Information System (INIS)

    Zhang Zhaohong; Shan Yabo; Wang Jun; Ling Hongjie; Zang Shuliang; Gao Wei; Zhao Zhe; Zhang Huachun

    2007-01-01

    Azo dyestuff-congo red in aqueous solution can be degraded rapidly under microwave irradiation in the presence of activated carbon powder. The results showed that the degradation ratio could reach 87.79% for 25 mL total volume with 50 mg/L congo red and 2.0 g/L activated carbon powder under 1.5 min microwave irradiation. Furthermore, within the same irradiation time, congo red could be degraded fully by increasing addition amount (e.g. 3.6 g/L) of activated carbon powder and the degradation ratio was up to 96.49%. Otherwise, with the same addition amount, congo red also could be degraded completely by prolonging irradiation time (e.g. 2.5 min) and the degradation ratio was up to 97.88%. In addition, the influences of microwave irradiation time, initial concentration of congo red, addition amount and used times of activated carbon powder as well as solution acidity on the degradation were discussed in details adopting UV-vis spectra, FT-IR spectra, ion chromatography, high phase liquid chromatography (HPLC) and TOC analysis technologies. Here, the method using activated carbon powder as catalyst under microwave irradiation shows many advantages including high degradation ratios, short reaction time, low costs, no intermediates and no secondary pollution. Therefore, it may be fit for dealing with various azo dyestuff wastewaters on a large scale

  14. Adsorption of malachite green on groundnut shell waste based powdered activated carbon

    International Nuclear Information System (INIS)

    Malik, R.; Ramteke, D.S.; Wate, S.R.

    2007-01-01

    In the present technologically fast changing situation related to waste management practices, it is desirable that disposal of plant waste should be done in a scientific manner by keeping in view economic and pollution considerations. This is only possible when the plant waste has the potential to be used as raw material for some useful product. In the present study, groundnut shell, an agricultural waste, was used for the preparation of an adsorbent by chemical activation using ZnCl 2 under optimized conditions and its comparative characterisation was conducted with commercially available powdered activated carbon (CPAC) for its physical, chemical and adsorption properties. The groundnut shell based powdered activated carbon (GSPAC) has a higher surface area, iodine and methylene blue number compared to CPAC. Both of the carbons were used for the removal of malachite green dye from aqueous solution and the effect of various operating variables, viz. adsorbent dose (0.1-1 g l -1 ), contact time (5-120 min) and adsorbate concentrations (100-200 mg l -1 ) on the removal of dye, has been studied. The experimental results indicate that at a dose of 0.5 g l -1 and initial concentration of 100 mg l -1 , GSPAC showed 94.5% removal of the dye in 30 min equilibrium time, while CPAC removed 96% of the dye in 15 min. The experimental isotherm data were analyzed using the linearized forms of Freundlich, Langmuir and BET equations to determine maximum adsorptive capacities. The equilibrium data fit well to the Freundlich isotherm, although the BET isotherm also showed higher correlation for both of the carbons. The results of comparative adsorption capacity of both carbons indicate that groundnut shell can be used as a low-cost alternative to commercial powdered activated carbon in aqueous solution for dye removal

  15. Fabricating solid carbon porous electrodes from powders

    Science.gov (United States)

    Kaschmitter, James L.; Tran, Tri D.; Feikert, John H.; Mayer, Steven T.

    1997-01-01

    Fabrication of conductive solid porous carbon electrodes for use in batteries, double layer capacitors, fuel cells, capacitive dionization, and waste treatment. Electrodes fabricated from low surface area (Electrodes having a higher surface area, fabricated from powdered carbon blacks, such as carbon aerogel powder, carbon aerogel microspheres, activated carbons, etc. yield high conductivity carbon compositives with excellent double layer capacity, and can be used in double layer capacitors, or for capacitive deionization and/or waste treatment of liquid streams. By adding metallic catalysts to be high surface area carbons, fuel cell electrodes can be produced.

  16. Direct observation of solid-phase adsorbate concentration profile in powdered activated carbon particle to elucidate mechanism of high adsorption capacity on super-powdered activated carbon.

    Science.gov (United States)

    Ando, Naoya; Matsui, Yoshihiko; Matsushita, Taku; Ohno, Koichi

    2011-01-01

    Decreasing the particle size of powdered activated carbon (PAC) by pulverization increases its adsorption capacities for natural organic matter (NOM) and polystyrene sulfonate (PSS, which is used as a model adsorbate). A shell adsorption mechanism in which NOM and PSS molecules do not completely penetrate the adsorbent particle and instead preferentially adsorb near the outer surface of the particle has been proposed as an explanation for this adsorption capacity increase. In this report, we present direct evidence to support the shell adsorption mechanism. PAC particles containing adsorbed PSS were sectioned with a focused ion beam, and the solid-phase PSS concentration profiles of the particle cross-sections were directly observed by means of field emission-scanning electron microscopy/energy-dispersive X-ray spectrometry (FE-SEM/EDXS). X-ray emission from sulfur, an index of PSS concentration, was higher in the shell region than in the inner region of the particles. The X-ray emission profile observed by EDXS did not agree completely with the solid-phase PSS concentration profile predicted by shell adsorption model analysis of the PSS isotherm data, but the observed and predicted profiles were not inconsistent when the analytical errors were considered. These EDXS results provide the first direct evidence that PSS is adsorbed mainly in the vicinity of the external surface of the PAC particles, and thus the results support the proposition that the increase in NOM and PSS adsorption capacity with decreasing particle size is due to the increase in external surface area on which the molecules can be adsorbed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Fly ash: An alternative to powdered activated carbon for the removal ...

    African Journals Online (AJOL)

    This paper reports the use of powdered activated carbon (PAC) and raw coal fly ash (RFA) in the removal of eosin dye from aqueous solution in batch processes. Operational parameters such as contact time, initial dye concentration, pH and temperature were investigated. Adsorption equilibrium was established in 120 min ...

  18. Assessing the chemical involvement of limestone powder in sodium carbonate activated slag

    NARCIS (Netherlands)

    Yuan, B.; Yu, Q.; Brouwers, H.J.H.

    2017-01-01

    This study aims to investigate the effect of limestone powder (LP) on the reaction of sodium carbonate activated slag. The results show that the incorporated LP up to 30% improves the strength development, especially at advanced curing ages. A slightly accelerated reaction is observed for samples

  19. Study of ageing mechanisms of organic electrolyte super-capacitors based on activated carbons; Recherche des causes du vieillissement de supercondensateurs a electrolyte organique a base de carbones actives

    Energy Technology Data Exchange (ETDEWEB)

    Azais, Ph

    2003-11-15

    The energy which is stored in electrochemical capacitors is proportional to the square of voltage. Consequently, the most attractive super-capacitors are those which operate in organic electrolyte medium, with an electrolyte potential window which theoretically can easily reach more than 3 V. However, even using lower values of voltage, there is a remarkable fading of the electrochemical characteristics with operating time, that is mainly characterized by capacitance loss and resistance increase. On a commercial point of view, these capacitors must be improved in order to reach the expected criterion of long operating life. In the presented work, we will determine some reasons of super-capacitors ageing in organic electrolyte (1 M solution of Et{sub 4}N{sup +} BF{sub 4}{sup -} in acetonitrile) and we will propose a treatment of activated carbon which noticeably improves the performance. A prolonged charging of electrochemical capacitors at 2.5 V, so called floating, results in gases formation and to a noticeable mass uptake of the electrodes. XPS and NMR analysis performed on carefully washed electrodes demonstrated the existence of decomposition products from the electrolyte, which are trapped in the pores of the activated carbon. These products block the pores, limiting the ions access to the active surface that causes the decay of electrochemical performances. Electrolyte decomposition is especially very high when the electrodes are constituted of carbons with a rich surface functionality, i.e. surface oxygenated groups and free radicals. Therefore, activated carbons have been submitted to thermal treatment, both in nitrogen and hydrogen atmosphere, allowing the oxygenated surface functionality to be noticeably depressed. Super-capacitors built with the treated materials have been submitted to floating during more than 2000 hours. Extremely good electrochemical performance are preserved with the electrodes obtained from activated carbons treated under hydrogen

  20. Determination of mercury and copper in water samples by activation analysis using preconcentration on emission spectroscopic carbon powder

    International Nuclear Information System (INIS)

    Nagatsuka, Sumiko; Tanizaki, Yoshiyuki

    1978-01-01

    A simple preconcentration procedure for mercury and copper was examined in the activation analysis of water samples. The preconcentration using pure activated carbon has been reported in several papers. The authors found that the carbon powder for emission spectroscopic analysis showed the high purity equivalent to pure activated carbon. The influence of various parameters in adsorption conditions was studied by radioactive tracers 197 Hg and 64 Cu. It was confirmed that 100% of these elements were adsorbed on carbon powders as pyrrolidine dithiocarbonate complexes at an acidity of pH 6 - 8, the temperature of 50 0 C and the stirring time of 30 minutes. This method was applied to the activation analysis of the river water samples taken from the upper stream area of the Arakawa river and the ground water samples taken from the wells of the environs of Tokyo Megalopolis. The carbon powders which adsorbed these elements were filtered, dried and analyzed by instrumental neutron activation analysis. The Hg concentrations of 0.01 - 0.1 ppb in river water and 0.03 - 1.4 ppb in ground water were obtained as well as the Cu concentrations of 0.3 - 3.0 ppb in ground water. The limits of determination of this method are 0.01 ppb Hg and 0.2 ppb Cu in the case of 1.1 sample of fresh water. (auth.)

  1. The elastic buckling of super-graphene and super-square carbon nanotube networks

    International Nuclear Information System (INIS)

    Li Ying; Qiu Xinming; Yin Yajun; Yang Fan; Fan Qinshan

    2010-01-01

    The super-graphene (SG) and super-square (SS) carbon nanotube network are built by the straight single-walled carbon nanotubes and corresponding junctions. The elastic buckling behaviors of these carbon nanotube networks under different boundary conditions are explored through the molecular structural mechanics method. The following results are obtained: (a) The critical buckling forces of the SG and SS networks decrease as the side lengths or aspect ratios of the networks increase. The continuum plate theory could give good predictions to the buckling of the SS network but not the SG network with non-uniform buckling modes. (b) The carbon nanotube networks are more stable structures than the graphene structures with less carbon atoms.

  2. Autogenous and drying shrinkage of sodium carbonate activated slag altered by limestone powder incorporation

    NARCIS (Netherlands)

    Yuan, B.; Yu, Q.L.; Dainese, E.; Brouwers, H.J.H.

    2017-01-01

    This paper aims to study the shrinkage mechanism of sodium carbonate activated slag containing limestone powder (LP). The workability, pore structure, reaction kinetics and strength development were characterized. The results show that the autogenous shrinkage increases when the dosage of LP is low

  3. Method for making carbon super capacitor electrode materials

    Science.gov (United States)

    Firsich, David W.; Ingersoll, David; Delnick, Frank M.

    1998-01-01

    A method for making near-net-shape, monolithic carbon electrodes for energy storage devices. The method includes the controlled pyrolysis and activation of a pressed shape of methyl cellulose powder with pyrolysis being carried out in two stages; pre-oxidation, preferably in air at a temperature between 200.degree.-250.degree. C., followed by carbonization under an inert atmosphere. An activation step to adjust the surface area of the carbon shape to a value desirable for the application being considered, including heating the carbon shape in an oxidizing atmosphere to a temperature of at least 300.degree. C., follows carbonization.

  4. Treatment of micropollutants in municipal wastewater: Ozone or powdered activated carbon?

    International Nuclear Information System (INIS)

    Margot, Jonas; Kienle, Cornelia; Magnet, Anoÿs; Weil, Mirco; Rossi, Luca; Alencastro, Luiz Felippe de; Abegglen, Christian; Thonney, Denis; Chèvre, Nathalie; Schärer, Michael

    2013-01-01

    Many organic micropollutants present in wastewater, such as pharmaceuticals and pesticides, are poorly removed in conventional wastewater treatment plants (WWTPs). To reduce the release of these substances into the aquatic environment, advanced wastewater treatments are necessary. In this context, two large-scale pilot advanced treatments were tested in parallel over more than one year at the municipal WWTP of Lausanne, Switzerland. The treatments were: i) oxidation by ozone followed by sand filtration (SF) and ii) powdered activated carbon (PAC) adsorption followed by either ultrafiltration (UF) or sand filtration. More than 70 potentially problematic substances (pharmaceuticals, pesticides, endocrine disruptors, drug metabolites and other common chemicals) were regularly measured at different stages of treatment. Additionally, several ecotoxicological tests such as the Yeast Estrogen Screen, a combined algae bioassay and a fish early life stage test were performed to evaluate effluent toxicity. Both treatments significantly improved the effluent quality. Micropollutants were removed on average over 80% compared with raw wastewater, with an average ozone dose of 5.7 mg O 3 l −1 or a PAC dose between 10 and 20 mg l −1 . Depending on the chemical properties of the substances (presence of electron-rich moieties, charge and hydrophobicity), either ozone or PAC performed better. Both advanced treatments led to a clear reduction in toxicity of the effluents, with PAC-UF performing slightly better overall. As both treatments had, on average, relatively similar efficiency, further criteria relevant to their implementation were considered, including local constraints (e.g., safety, sludge disposal, disinfection), operational feasibility and cost. For sensitive receiving waters (drinking water resources or recreational waters), the PAC-UF treatment, despite its current higher cost, was considered to be the most suitable option, enabling good removal of most

  5. Method of producing radioactive carbon powder

    International Nuclear Information System (INIS)

    Imamura, Y.

    1980-01-01

    Carbon powder, placed in a hermetically closed apparatus under vacuum together with radium ore, adsorbs radon gas emanating from the radium ore thus producing a radioactive carbonaceous material, the radioactivity of which is due to the presence of adsorbed radon. The radioactive carbon powder thus obtained has excellent therapeutical efficacy and is suitable for a variety of applications because of the mild radioactivity of radon. Radium ore permits substantially limitlessly repeated production of the radioactive carbon powder

  6. Fabrication and anti-frosting performance of super hydrophobic coating based on modified nano-sized calcium carbonate and ordinary polyacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hao [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China); Tang Liming [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: tanglm@mail.tsinghua.edu.cn; Wu Xiaomin; Dai Wantian [Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Qiu Yipeng [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

    2007-09-15

    Nano-sized calcium carbonate (CaCO{sub 3}) particles were modified by heptadecafluorodecyl trimethoxysilane under acidic water condition. An ordinary polyacrylate prepared via radical copolymerization of methyl methacrylate, butyl acrylate, acrylic acid and {beta}-hydroxyethyl methacrylate was used as the binder to form hydrophobic coatings with the modified CaCO{sub 3}. Super hydrophobic coating with water contact angle of 155{sup o} was obtained from modified CaCO{sub 3} and the polyacrylate at their weight ratio of 8/2 by a simple procedure. Based on surface analysis by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), the super hydrophobicity can be attributed to both the surface microstructure and surface enrichment of fluoroalkyl chains. Due to a low water sliding angle, carbon black powder on super hydrophobic surface was easily removed by rolling water droplet. Furthermore, the anti-frosting performance of different surfaces was investigated, which indicated that the frost formed on superhydrophobic surface was greatly retarded compared with that on bare copper surface. The surface kept super hydrophobicity even after freezing-thawing treatment for 10 times.

  7. Effects of Temperature variations on the Super Fine Powderization of Korean Cultivated Wild Ginseng

    Directory of Open Access Journals (Sweden)

    Jin Ho Kim

    2006-12-01

    Full Text Available Objectives : The aim of this study was to find optimal conditions for producing red ginseng from cultivated wild ginseng using the Turbo Mill. Methods : Characteristics of powdered cultivated wild ginseng based on various temperature settings of the Turbo Mill were observed, and changes in the content was measured by HPLC for various ginsenosides. Results : 1. The diameter of cultivated wild ginseng powder ground by the Turbo Mill was around 10㎛. 2. As the temperature rose, presusre, Specific Mechanical Energy(SME, and density decreased, whileas Water Solubility Index(WSI increased. 3. As the temperature rose, super fine powder showed tendency to turn into dark brown. 4. Measuring content changes by HPLC, there was no detection of ginsenoside Rg3 and ginsenosideRg1, Rb1, and Rh2 concentrations decreased with increase in temperature. Conclusions : Super fine powder of cultivated wild ginseng produced by the Turbo Mill promotes easy absorption of effective ingredients by breaking the cell walls. Using this mechanism to produce red ginseng from cultivated wild ginseng, it yielded less than satisfactory results under the current experiment setup. Furtherresearches are needed to verify more suitable condition for the production of red ginseng.

  8. Super-Hydrophobic Green Corrosion Inhibitor On Carbon Steel

    Science.gov (United States)

    Hassan, H.; Ismail, A.; Ahmad, S.; Soon, C. F.

    2017-06-01

    There are many examples of organic coatings used for corrosion protection. In particular, hydrophobic and super-hydrophobic coatings are shown to give good protection because of their enhanced ability to slow down transport of water and ions through the coating. The purpose of this research is to develop water repellent coating to avoid direct contact between metal and environment corrosive and mitigate corrosion attack at pipeline system. This water repellent characteristic on super-hydrophobic coating was coated by electrodeposition method. Wettability of carbon steel with super-hydrophobic coating (cerium chloride and myristic acid) and oxidized surface was investigated through contact angle and inhibitor performance test. The inhibitor performance was studied in 25% tannin acid corrosion test at 30°C and 3.5% sodium chloride (NaCl). The water contact angle test was determined by placing a 4-μL water droplet of distilled water. It shows that the wettability of contact angle super-hydrophobic with an angle of 151.60° at zero minute can be classified as super-hydrophobic characteristic. By added tannin acid as inhibitor the corrosion protection on carbon steel becomes more consistent. This reveals that the ability of the coating to withstand with the corrosion attack in the seawater at different period of immersions. The results elucidate that the weight loss increased as the time of exposure increased. However, the corrosion rates for uncoated carbon steel is high compared to coated carbon steel. As a conclusion, from both samples it can be seen that the coated carbon steel has less corrosion rated compared to uncoated carbon steel and addition of inhibitor to the seawater provides more protection to resist corrosion attack on carbon steel.

  9. Elemental mercury vapor capture by powdered activated carbon in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Fabrizio Scala; Riccardo Chirone; Amedeo Lancia [Istituto di Ricerche sulla Combustione - CNR, Napoli (Italy)

    2011-06-15

    A bubbling fluidized bed of inert material was used to increase the activated carbon residence time in the reaction zone and to improve its performance for mercury vapor capture. Elemental mercury capture experiments were conducted at 100{sup o}C in a purposely designed 65 mm ID lab-scale pyrex reactor, that could be operated both in the fluidized bed and in the entrained bed configurations. Commercial powdered activated carbon was pneumatically injected in the reactor and mercury concentration at the outlet was monitored continuously. Experiments were carried out at different inert particle sizes, bed masses, fluidization velocities and carbon feed rates. Experimental results showed that the presence of a bubbling fluidized bed led to an increase of the mercury capture efficiency and, in turn, of the activated carbon utilization. This was explained by the enhanced activated carbon loading and gas-solid contact time that establishes in the reaction zone, because of the large surface area available for activated carbon adhesion/deposition in the fluidized bed. Transient mercury concentration profiles at the bed outlet during the runs were used to discriminate between the controlling phenomena in the process. Experimental data have been analyzed in the light of a phenomenological framework that takes into account the presence of both free and adhered carbon in the reactor as well as mercury saturation of the adsorbent. 14 refs., 7 figs.

  10. Freundlich adsorption isotherms of agricultural by-product-based powdered activated carbons in a geosmin-water system

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Chilton [Food and Drug Administration, Dept. of Health and Human Services, Lenexa, KS (United States); Losso, Jack N.; Rao, Ramu M. [Louisiana State Univ. Agricultural Center, Dept. of Food Science, Baton Rouge, LA (United States); Marshall, Wayne E. [USDA-ARS, Southern Regional Research Center, New Orleans, LA (United States)

    2002-11-01

    The present study was designed to model the adsorption of geosmin from water under laboratory conditions using the Freundlich isotherm model. This model was used to compare the efficiency of sugarcane bagasse and pecan shell-based powdered activated carbon to the efficiency of a coal-based commercial activated carbon (Calgon Filtrasorb 400). When data were generated from Freundlich isotherms, Calgon Filtrasorb 400 had greater geosmin adsorption at all geosmin concentrations studied than the laboratory produced steam-activated pecan shell carbon, steam-activated bagasse carbon, and the CO{sub 2}-activated pecan shell carbon. At geosmin concentrations <0.07 {sup {mu}}g/l for the phosphoric acid-activated pecan shell carbon and below 0.08 {sup {mu}}g/l for a commercially produced steam-activated pecan shell carbon obtained from Scientific Carbons, these two carbons had a higher calculated geosmin adsorption than Filtrasorb 400. While the commercial carbon was more efficient than some laboratory prepared carbons at most geosmin concentrations, the results indicate that when the amount of geosmin was below the threshold level of human taste (about 0.10 {sup {mu}}g/l), the phosphoric acid-activated pecan shell carbon and the Scientific Carbons sample were more efficient than Filtrasorb 400 at geosmin removal. (Author)

  11. Ceramic Membrane combined with Powdered Activated Carbon (PAC) or Coagulation for Treatment of Impaired Quality Waters

    KAUST Repository

    Hamad, Juma Z.

    2013-01-01

    and adsorption can remove some organic matter but with a low removal of the biopolymers component which is responsible for fouling. Powdered activated carbon (PAC) accompanied with a LPM maintains good removal of TOrCs. However, enhanced removal of TOr

  12. A Carbon Flux Super Site. New Insights and Innovative Atmosphere-Terrestrial Carbon Exchange Measurements and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Leclerc, Monique Y. [The University of Georgia Research Foundation, Athens, GA (United States)

    2014-11-17

    This final report presents the main activities and results of the project “A Carbon Flux Super Site: New Insights and Innovative Atmosphere-Terrestrial Carbon Exchange Measurements and Modeling” from 10/1/2006 to 9/30/2014. It describes the new AmeriFlux tower site (Aiken) at Savanna River Site (SC) and instrumentation, long term eddy-covariance, sodar, microbarograph, soil and other measurements at the site, and intensive field campaigns of tracer experiment at the Carbon Flux Super Site, SC, in 2009 and at ARM-CF site, Lamont, OK, and experiments in Plains, GA. The main results on tracer experiment and modeling, on low-level jet characteristics and their impact on fluxes, on gravity waves and their influence on eddy fluxes, and other results are briefly described in the report.

  13. Immobilized acclimated biomass-powdered activated carbon for the bioregeneration of granular activated carbon loaded with phenol and o-cresol.

    Science.gov (United States)

    Toh, Run-Hong; Lim, Poh-Eng; Seng, Chye-Eng; Adnan, Rohana

    2013-09-01

    The objectives of the study are to use immobilized acclimated biomass and immobilized biomass-powdered activated carbon (PAC) as a novel approach in the bioregeneration of granular activated carbon (GAC) loaded with phenol and o-cresol, respectively, and to compare the efficiency and rate of the bioregeneration of the phenolic compound-loaded GAC using immobilized and suspended biomasses under varying GAC dosages. Bioregeneration of GAC loaded with phenol and o-cresol, respectively, was conducted in batch system using the sequential adsorption and biodegradation approach. The results showed that the bioregeneration efficiency of GAC loaded with phenol or o-cresol was basically the same irrespective of whether the immobilized or suspended biomass was used. Nonetheless, the duration for bioregeneration was longer under immobilized biomass. The beneficial effect of immobilized PAC-biomass for bioregeneration is the enhancement of the removal rate of the phenolic compounds via adsorption and the shortening of the bioregeneration duration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Preparation of very pure active carbon

    International Nuclear Information System (INIS)

    Sloot, H.A. van der; Hoede, D.; Zonderhuis, J.; Meijer, C.

    1980-02-01

    The preparation of very pure active carbon is described. Starting from polyvinylidene chloride active carbon is prepared by carbonization in a nitrogen atmosphere, grinding, sieving and activation of the powder fraction with CO 2 at 950 0 to approximately 50% burn-off. The concentrations of trace and major elements are reduced to the ppb and ppm level, respectively. In the present set-up 100 g of carbon grains and approximately 50 g of active carbon powder can be produced weekly

  15. CVD carbon powders modified by ball milling

    Directory of Open Access Journals (Sweden)

    Kazmierczak Tomasz

    2015-09-01

    Full Text Available Carbon powders produced using a plasma assisted chemical vapor deposition (CVD methods are an interesting subject of research. One of the most interesting methods of synthesizing these powders is using radio frequency plasma. This method, originally used in deposition of carbon films containing different sp2/sp3 ratios, also makes possible to produce carbon structures in the form of powder. Results of research related to the mechanical modification of these powders have been presented. The powders were modified using a planetary ball mill with varying parameters, such as milling speed, time, ball/powder mass ratio and additional liquids. Changes in morphology and particle sizes were measured using scanning electron microscopy and dynamic light scattering. Phase composition was analyzed using Raman spectroscopy. The influence of individual parameters on the modification outcome was estimated using statistical method. The research proved that the size of obtained powders is mostly influenced by the milling speed and the amount of balls. Powders tend to form conglomerates sized up to hundreds of micrometers. Additionally, it is possible to obtain nanopowders with the size around 100 nm. Furthermore, application of additional liquid, i.e. water in the process reduces the graphitization of the powder, which takes place during dry milling.

  16. Influence of Chemical and Physical Properties of Activated Carbon Powders on Oxygen Reduction and Microbial Fuel Cell Performance

    KAUST Repository

    Watson, Valerie J.; Nieto Delgado, Cesar; Logan, Bruce E.

    2013-01-01

    Commercially available activated carbon (AC) powders made from different precursor materials (coal, peat, coconut shell, hardwood, and phenolic resin) were electrochemically evaluated as oxygen reduction catalysts and tested as cathode catalysts

  17. Preparation of nanosize carbon powders by pulsed wire discharge

    Energy Technology Data Exchange (ETDEWEB)

    Minami, C.; Kinemuchi, Y.; Suzuki, T.; Suematsu, H.; Jiang, W.; Yatsui, K. [Nagaoka Univ. of Technology, Extreme Energy-Density Research Inst., Nagaoka, Niigata (Japan); Hirata, T.; Hatakeyama, R. [Tohoku Univ., Graduate School of Engineering, Sendai, Miyagi (Japan)

    2002-06-01

    Nanosize powders of carbons were tried to be synthesized by pulsed discharge of graphite wires in several kinds of ambient gases. When the wire was discharged in N{sub 2} gas, nanosize powders have been successfully produced. The result of X-ray diffraction analysis indicated that nanosize powders produced in N{sub 2} gas at 750 Torr were amorphous carbon containing glassy carbons, while mass-spectrum analysis demonstrated the production of fullerenes at 600 Torr. If the wire is discharged in Ar gas, dielectric breakdown takes place between electrodes, producing no carbon powders. (author)

  18. The influence of iron oxide nanoparticles upon the adsorption of organic matter on magnetic powdered activated carbon.

    Science.gov (United States)

    Lompe, Kim Maren; Menard, David; Barbeau, Benoit

    2017-10-15

    Combining powdered activated carbon (PAC) with magnetic iron oxides has been proposed in the past to produce adsorbents for natural organic matter (NOM) removal that can be easily separated using a magnetic field. However, the trade-off between the iron oxides' benefits and the reduced carbon content, porosity, and surface area has not yet been investigated systematically. We produced 3 magnetic powdered activated carbons (MPAC) with mass fractions of 10%, 38% and 54% maghemite nanoparticles and compared them to bare PAC and pure nanoparticles with respect to NOM adsorption kinetics and isotherms. While adsorption kinetics were not influenced by the presence of the iron oxide nanoparticles (IONP), as shown by calculated diffusion coefficients from the homogeneous surface diffusion model, nanoparticles reduced the adsorption capacity of NOM due to their lower adsorption capacity. Although the nanoparticles added mesoporosity to the composite materials they blocked intrinsic PAC mesopores at mass fractions >38% as measured by N 2 -adsorption isotherms. Below this mass fraction, the adsorption capacity was mainly dependent on the carbon content in MPAC and mesopore blocking was negligible. If NOM adsorption with MPAC is desired, a highly mesoporous PAC and a low IONP mass fraction should be chosen during MPAC synthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Polyphenol-Retaining Decaffeinated Cocoa Powder Obtained by Supercritical Carbon Dioxide Extraction and Its Antioxidant Activity.

    Science.gov (United States)

    Kobori, Kinji; Maruta, Yuto; Mineo, Shigeru; Shigematsu, Toru; Hirayama, Masao

    2013-10-14

    Cocoa beans contain many functional ingredients such as theobromine and polyphenols, but also contain a relatively high amount of caffeine, which can negatively impact human health. It is therefore desirable to reduce caffeine levels in cocoa powder used to make chocolate or cocoa beverages while retaining functional ingredients. We have established conditions for supercritical carbon dioxide (SCCO₂) extraction that remove 80.1% of the caffeine from cocoa powder while retaining theobromine (94.1%) and polyphenols (84.7%). The antioxidant activity of the decaffeinated cocoa powder (DCP) made with this optimized SCCO₂ extraction method was 85.3% that of non-processed cocoa powder. The total procyanidin and total polyphenol concentrations of the DCPs resulting from various SCCO₂ extractions showed a significant positive correlation with oxygen radical absorbance capacity (ORAC). The correlation coefficient between total polyphenols and ORAC was higher than that between total procyanidins and ORAC; thus, the concentration of total polyphenols might be a greater factor in the antioxidant activity of DCP. These results indicate that we could remove large quantities of caffeine from conventional high-cocoa products while retaining the functional benefits of high polyphenol content. This SCCO₂ extraction method is expected to be applicable high-cocoa products, such as dark chocolate.

  20. Polyphenol-Retaining Decaffeinated Cocoa Powder Obtained by Supercritical Carbon Dioxide Extraction and Its Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Kinji Kobori

    2013-10-01

    Full Text Available Cocoa beans contain many functional ingredients such as theobromine and polyphenols, but also contain a relatively high amount of caffeine, which can negatively impact human health. It is therefore desirable to reduce caffeine levels in cocoa powder used to make chocolate or cocoa beverages while retaining functional ingredients. We have established conditions for supercritical carbon dioxide (SCCO2 extraction that remove 80.1% of the caffeine from cocoa powder while retaining theobromine (94.1% and polyphenols (84.7%. The antioxidant activity of the decaffeinated cocoa powder (DCP made with this optimized SCCO2 extraction method was 85.3% that of non-processed cocoa powder. The total procyanidin and total polyphenol concentrations of the DCPs resulting from various SCCO2 extractions showed a significant positive correlation with oxygen radical absorbance capacity (ORAC. The correlation coefficient between total polyphenols and ORAC was higher than that between total procyanidins and ORAC; thus, the concentration of total polyphenols might be a greater factor in the antioxidant activity of DCP. These results indicate that we could remove large quantities of caffeine from conventional high-cocoa products while retaining the functional benefits of high polyphenol content. This SCCO2 extraction method is expected to be applicable high-cocoa products, such as dark chocolate.

  1. Application of Pre-coated Microfiltration Ceramic Membrane with Powdered Activated Carbon for Natural Organic Matter Removal from Secondary Wastewater Effluent

    KAUST Repository

    Kurniasari, Novita

    2012-12-01

    Ceramic membranes offer more advantageous performances than conventional polymeric membranes. However, membrane fouling caused by Natural Organic Matters (NOM) contained in the feed water is still become a major problem for operational efficiency. A new method of ceramic membrane pre-coating with Powdered Activated Carbon (PAC), which allows extremely contact time for adsorbing aquatic contaminants, has been studied as a pre-treatment prior to ceramic microfiltration membrane. This bench scale study evaluated five different types of PAC (SA Super, G 60, KCU 6, KCU 8 and KCU 12,). The results showed that KCU 6 with larger pore size was performed better compared to other PAC when pre-coated on membrane surface. PAC pre-coating on the ceramic membrane with KCU 6 was significantly enhance NOM removal, reduced membrane fouling and improved membrane performance. Increase of total membrane resistance was suppressed to 96%. The removal of NOM components up to 92%, 58% and 56% for biopolymers, humic substances and building blocks, respectively was achieved at pre-coating dose of 30 mg/l. Adsorption was found to be the major removal mechanism of NOM. Results obtained showed that biopolymers removal are potentially correlated with enhanced membrane performance.

  2. Carbon Sequestration in Olivine and Basalt Powder Packed Beds.

    Science.gov (United States)

    Xiong, Wei; Wells, Rachel K; Giammar, Daniel E

    2017-02-21

    Fractures and pores in basalt could provide substantial pore volume and surface area of reactive minerals for carbonate mineral formation in geologic carbon sequestration. In many fractures solute transport will be limited to diffusion, and opposing chemical gradients that form as a result of concentration differences can lead to spatial distribution of silicate mineral dissolution and carbonate mineral precipitation. Glass tubes packed with grains of olivine or basalt with different grain sizes and compositions were used to explore the identity and spatial distribution of carbonate minerals that form in dead-end one-dimensional diffusion-limited zones that are connected to a larger reservoir of water in equilibrium with 100 bar CO 2 at 100 °C. Magnesite formed in experiments with olivine, and Mg- and Ca-bearing siderite formed in experiments with flood basalt. The spatial distribution of carbonates varied between powder packed beds with different powder sizes. Packed beds of basalt powder with large specific surface areas sequestered more carbon per unit basalt mass than powder with low surface area. The spatial location and extent of carbonate mineral formation can influence the overall ability of fractured basalt to sequester carbon.

  3. Reduction and Removal of Chromium VI in Water by Powdered Activated Carbon

    Directory of Open Access Journals (Sweden)

    Yanan Chen

    2018-02-01

    Full Text Available Cr adsorption on wood-based powdered activated carbon (WPAC was characterized by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS. The highest Cr(VI adsorption (40.04% was obtained under acidic conditions (pH 3, whereas Cr removal at pH 10 was only 0.34%. The mechanism of Cr(VI removal from aqueous solutions by WPAC was based on the reduction of Cr(VI to Cr(III with the concomitant oxidation of C-H and C-OH to C-OH and C=O, respectively, on the surface of WPAC, followed by Cr(III adsorption. Raman spectroscopy revealed a change in the WPAC structure in terms of the D/G band intensity ratio after Cr(VI adsorption. SEM-EDS analysis showed that the oxygen/carbon ratio on the WPAC surface increased from 9.85% to 17.74%. This result was confirmed by XPS measurements, which showed that 78.8% of Cr adsorbed on the WPAC surface was in the trivalent state. The amount of oxygen-containing functional groups on the surface increased due to the oxidation of graphitic carbons to C-OH and C=O groups.

  4. Highly porous activated carbons prepared from carbon rich Mongolian anthracite by direct NaOH activation

    Energy Technology Data Exchange (ETDEWEB)

    Byamba-Ochir, Narandalai [School of Chemical Engineering, Chonnam National University, 77 Yongbong-Ro, Gwangju 61186 (Korea, Republic of); Shim, Wang Geun [Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-Ro, Suncheon, Jeollanam-Do 57922 (Korea, Republic of); Balathanigaimani, M.S., E-mail: msbala@rgipt.ac.in [Department of Chemical Engineering, Rajiv Gandhi Institute of Petroleum Technology, Ratapur Chowk, Rae Bareli, 229316 Uttar Pradesh (India); Moon, Hee, E-mail: hmoon@jnu.ac.kr [School of Chemical Engineering, Chonnam National University, 77 Yongbong-Ro, Gwangju 61186 (Korea, Republic of)

    2016-08-30

    Highlights: • Highly porous carbon materials from Mongolian anthracite by chemical activation. • Cheaper and eco-friendly activation process has been employed. • Activated carbons with graphitic structure and energetically heterogeneous surface. • Surface hydrophobicity and porosity of the activated carbons can be controlled. - Abstract: Highly porous activated carbons (ACs) were prepared from Mongolian raw anthracite (MRA) using sodium hydroxide as an activation agent by varying the mass ratio (powdered MRA/NaOH) as well as the mixing method of chemical agent and powdered MRA. The specific BET surface area and total pore volume of the prepared MRA-based activated carbons (MACs) are in the range of 816–2063 m{sup 2}/g and of 0.55–1.61 cm{sup 3}/g, respectively. The pore size distribution of MACs show that most of the pores are in the range from large micropores to small mesopores and their distribution can be controlled by the mass ratio and mixing method of the activating agent. As expected from the intrinsic property of the MRA, the highly graphitic surface morphology of prepared carbons was confirmed from Raman spectra and transmission electron microscopy (TEM) studies. Furthermore the FTIR and XPS results reveal that the preparation of MACs with hydrophobic in nature is highly possible by controlling the mixing conditions of activating agent and powdered MRA. Based on all the results, it is suggested that the prepared MACs could be used for many specific applications, requiring high surface area, optimal pore size distribution, proper surface hydrophobicity as well as strong physical strength.

  5. Electrical conductivity of compacts of graphene, multi-wall carbon nanotubes, carbon black, and graphite powder

    NARCIS (Netherlands)

    Marinho, B.; Gomes Ghislandi, M.; Tkalya, E.; Koning, C.E.; With, de G.

    2012-01-01

    The electrical conductivity of different carbon materials (multi-walled carbon nanotubes, graphene, carbon black and graphite), widely used as fillers in polymeric matrices, was studied using compacts produced by a paper preparation process and by powder compression. Powder pressing assays show that

  6. Effects of Different Water and Super Plasticizer Amount, Pre-Setting and Curing Regimes on the Behavior of Reactive Powder Concrete

    Directory of Open Access Journals (Sweden)

    M. A. Dashti Rahmatabadi

    2014-12-01

    Full Text Available Reactive Powder Concrete (RPC is an ultra high performance concrete which has superior mechanical and physical properties. The RPC is composed of cement and very fine powders such as crushed quartz (100–600 μm and silica fume with very low water/binder ratio (W/B (less than 0.20 and Super Plasticizer (SP. The RPC has a very high compressive and tensile strength with better durability properties than current high performance concretes. Application of very low water/binder ratio with a high dosage of super plasticizer, different heat curing processes and pre-setting pressure improve mechanical and physical properties of RPC. In this study, the RPC is composed of available materials in Iran. Two different mixing proportions, different water/binder ratios for preparation of samples, different super plasticizer dosages, five different (0, 25, 50, 100 and 150 MPa pre-setting pressure and 7 different curing regimes were used in samples preparation and experiments. Results showed that appropriate water/binder ratio and super plasticizer dosage, higher temperature and pre-setting pressure increase the workability, density and compressive strength of compositions.

  7. The effect of mixed oxidants and powdered activated carbon on the removal of natural organic matter.

    Science.gov (United States)

    Alvarez-Uriarte, Jon I; Iriarte-Velasco, Unai; Chimeno-Alanís, Noemí; González-Velasco, Juan R

    2010-09-15

    Present paper studies the influence of electrochemically generated mixed oxidants on the physicochemical properties of natural organic matter, and especially from the disinfection by-products formation point of view. The study was carried out in a full scale water treatment plant. Results indicate that mixed oxidants favor humic to non-humic conversion of natural organic matter. Primary treatment preferentially removes the more hydrophobic fraction. This converted the non-humic fraction in an important source of disinfection by-products with a 20% contribution to the final trihalomethane formation potential (THMFP(F)) of the finished water. Enhanced coagulation at 40 mg l(-1) of polyaluminium chloride with a moderate mixing intensity (80 rpm) and pH of 6.0 units doubled the removal efficiency of THMFP(F) achieved at full scale plant. However, gel permeation chromatography data revealed that low molecular weight fractions were still hardly removed. Addition of small amounts of powdered activated carbon, 50 mg l(-1), allowed reduction of coagulant dose by 50% whereas removal of THMFP(F) was maintained or even increased. In systems where mixed oxidants are used addition of powdered activated carbon allows complementary benefits by a further reduction in the THMFP(F) compared to the conventional only coagulation-flocculation-settling process. Copyright 2010 Elsevier B.V. All rights reserved.

  8. High-surface-area active carbon

    International Nuclear Information System (INIS)

    O'Grady, T.M.; Wennerberg, A.N.

    1986-01-01

    This paper describes the preparation and properties of a unique active carbon having exceptionally high surface areas, over 2500 m 2 /gm, and extraordinary adsorptive capacities. The carbon is made by a direct chemical activation route in which petroleum coke or other carbonaceous sources are reacted with excess potassium hydroxide at 400 0 to 500 0 C to an intermediate product that is subsequently pyrolyzed at 800 0 to 900 0 C to active carbon containing potassium salts. These are removed by water washing and the carbon is dried to produce a powdered product. A granular carbon can also be made by further processing the powdered carbon by using specialized granulation techniques. Typical properties of the carbon include Iodine Numbers of 3000 to 3600, methylene blue adsorption of 650 to 750 mg/gm, pore volumes of 2.0 to 2.6 cc/gm and less than 3.0% ash. This carbon's high adsorption capacities make it uniquely suited for numerous demanding applications in the medical area, purifications, removal of toxic substances, as catalyst carriers, etc

  9. Decolorization of turbid sugar juice from sugar factory using waste powdered carbon

    Science.gov (United States)

    Aljohani, Hind; Ahmed, Youssef; El-Shafey, Ola; El-Shafey, Shaymaa; Fouad, Rasha; Shoueir, Kamel

    2018-03-01

    Waste management of powdered activated carbon from cyclone of some sugar factories was used for decolorization of sugar mud juice (SMJ) in this study. The presence of powdered activated carbon waste (PACW) was admitted again for their use in SMJ decolorization. The determined specific surface area are typically S BET = 613.887 m2/g and the pore distribution lies in mesoporous domain. Color removal (CR%) and decolorization capacity (DC) of the characterized PACW are similar to those of decolorants used at this time for sugar refining. The CR% with PACW reached 81.03% at pH7.0 and dosed in the amount 0.5 g/50 ml of SMJ. There are two acceptable mechanisms illustrates the attachments between phenols and carboxylate ions. In this paper, we put a simple and rapid dark liquid decolorization by controlling rejected carbon waste, which will be useful for treatment of dark liquid sugar.

  10. Adsorption of N-nitrosodimethylamine precursors by powdered and granular activated carbon.

    Science.gov (United States)

    Hanigan, David; Zhang, Jinwei; Herckes, Pierre; Krasner, Stuart W; Chen, Chao; Westerhoff, Paul

    2012-11-20

    Activated carbon (AC) has been shown to remove precursors of halogenated disinfection byproducts. Granular and powdered activated carbon (GAC, PAC) were investigated for their potential to adsorb N-nitrosodimethylamine (NDMA) precursors from blends of river water and effluent from a wastewater treatment plant (WWTP). At bench scale, waters were exposed to lignite or bituminous AC, either as PAC in bottle point experiments or as GAC in rapid small-scale column tests (RSSCTs). NDMA formation potential (FP) was used as a surrogate for precursor removal. NDMA FP was reduced by 37, 59, and 91% with 3, 8, and 75 mg/L of one PAC, respectively, with a 4-h contact time. In RSSCTs and in full-scale GAC contactors, NDMA FP removal always exceeded that of the bulk dissolved organic carbon (DOC) and UV absorbance at 254 nm. For example, whereas DOC breakthrough exceeded 90% of its influent concentration after 10,000 bed volumes of operation in an RSSCT, NDMA FP was less than 40% of influent concentration after the same bed life of the GAC. At full or pilot scale, high NDMA FP reduction ranging from >60 to >90% was achieved across GAC contactors, dependent upon the GAC bed life and/or use of a preoxidant (chlorine or ozone). In all experiments, NDMA formation was not reduced to zero, which suggests that although some precursors are strongly sorbed, others are not. This is among the first studies to show that AC is capable of adsorbing NDMA precursors, but further research is needed to better understand NDMA precursor chemical properties (e.g., hydrophobicity, molecular size) and evaluate how best to incorporate this finding into full-scale designs and practice.

  11. PREPARATION OF WC-Co POWDER BY DIRECT REDUCTION AND CARBONIZATION

    Institute of Scientific and Technical Information of China (English)

    Zhonglai Yi; Gangqin Shao; Xinglong Duan; Peng Sun; Xiaoliang Shi; Zhen Xiong; Jingkun Guo

    2005-01-01

    A new approach to produce superfine WC-Co powder by direct reduction and carbonization is proposed.Water-soluble salts containing W and Co were used as raw materials. Tungsten and cobalt oxide powder (CoWO4/WO3)was first formed by a spray-pyrolysis technique, which was then mixed with carbon black and converted to WC-Co composite powder at 950℃ for 4 h in N2 atmosphere. The resulting powder has a particle size of 100-300 nm.

  12. Investigation of Structure and Physico-Mechanical Properties of Composite Materials Based on Copper - Carbon Nanoparticles Powder Systems

    Directory of Open Access Journals (Sweden)

    Kovtun V.

    2015-04-01

    Full Text Available Physico-mechanical and structural properties of electrocontact sintered copper matrix- carbon nanoparticles composite powder materials are presented. Scanning electron microscopy revealed the influence of preliminary mechanical activation of the powder system on distribution of carbon nanoparticles in the metal matrix. Mechanical activation ensures mechanical bonding of nanoparticles to the surface of metal particles, thus giving a possibility for manufacture of a composite with high physico-mechanical properties.

  13. Characteristics of powdered activated carbon treated with dielectric barrier discharge for electric double-layer capacitors

    International Nuclear Information System (INIS)

    Tashima, Daisuke; Yoshitama, Hiromu; Sakoda, Tatsuya; Okazaki, Akihito; Kawaji, Takayuki

    2012-01-01

    Highlights: ► The specific capacitance of the EDLCs could be improved by oxygen plasma treatment. ► 15 s treated EDLCs showed a 20% increase in capacitance relative to untreated EDLCs. ► The plasma treatment yields EDLCs that are suitable for high-energy applications. - Abstract: The electrochemical properties of electric double-layer capacitors (EDLCs) made with plasma-treated powdered activated carbon (treated using a dielectric barrier discharge) were examined using cyclic voltammetry (CV), Cole–Cole plots, and X-ray photoelectron spectroscopy (XPS). The dielectric barrier discharge method, which operates at atmospheric pressure, dramatically reduces the processing time and does not require vacuum equipment, making it a more practical alternative than low-pressure plasma treatment. The experimental data indicate that the specific capacitance of the EDLCs could be improved by oxygen plasma treatment. Capacitance of EDLCs made with activated carbon treated for 15 s showed 193.5 F/g that 20% increase in the specific capacitance relative to untreated EDLCs. This result indicates that the plasma treatment yields EDLCs that are suitable for high-energy applications. The enhancement of capacitance was mainly attributed to an increase in the BET surface area of the activated carbon and the creation of carboxyl groups on the surface of the carbon. The carboxyl groups induced oxidation–reduction reactions in the presence of O 2 which was included in the operation gas. In addition, the carboxyl groups improved the penetration of the electrolyte solution into the carbon electrodes.

  14. One-Step Hydrothermal-Electrochemical Route to Carbon-Stabilized Anatase Powders

    Science.gov (United States)

    Tao, Ying; Yi, Danqing; Zhu, Baojun

    2013-04-01

    Black carbon-stabilized anatase particles were prepared by a simple one-step hydrothermal-electrochemical method using glucose and titanium citrate as the carbon and titanium source, respectively. Morphological, chemical, structural, and electrochemical characterizations of these powders were carried out by Raman spectroscopy, Fourier-transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy, and cyclic voltammetry. It was revealed that 200-nm carbon/anatase TiO2 was homogeneously dispersed, and the powders exhibited excellent cyclic performance at high current rates of 0.05 V/s. The powders are interesting potential materials that could be used as anodes for lithium-ion batteries.

  15. Ceramic Membrane combined with Powdered Activated Carbon (PAC) or Coagulation for Treatment of Impaired Quality Waters

    KAUST Repository

    Hamad, Juma Z.

    2013-08-29

    Ceramic membranes (CM) are robust membranes attributed with high production, long life span and stability against critical conditions. While capital costs are high, these are partially offset by lower operation and maintenance costs compared to polymeric membranes. Like any other low-pressure membrane (LPM), CM faces problems of fouling, low removal of organic matter and poor removal of trace organic compounds (TOrCs). Current pretreatment approaches that are mainly based on coagulation and adsorption can remove some organic matter but with a low removal of the biopolymers component which is responsible for fouling. Powdered activated carbon (PAC) accompanied with a LPM maintains good removal of TOrCs. However, enhanced removal of TOrCs to higher level is required. Submicron powdered activated carbon (SPAC), obtained after crushing commercial activated carbon into very fine particle, and novel activated carbon (KCU 6) which is characterized with larger pores and high surface area were employed. A pre-coating approach, which provides intimated contact between PAC and contaminants, was adopted for wastewater and (high DOC) surface water treatment. For seawater, in-line coagulation with iron III chloride was adopted. Both SPAC and KCU 6 showed good removal of biopolymers at a dose of 30 mg/L with > 85 % and 90 %, respectively. A dose of 40 mg/L of SPAC and 30 mg/L KCU 6 pre-coats were successful used in controlling membrane fouling. SPAC is suggested to remove biopolymers by physical means and adsorption while KCU 6 removed biopolymers through adsorption. Both KCU 6 and SPAC attained high removal of TOrCs whereas KCU 6 showed outstanding performance. Out of 29 TOrCs investigated, KCU 6 showed > 87 % TOrCs rejection for 28 compounds. In seawater pretreatment, transparent exopolymer particles (TEP) were found to be an important foulant. TEP promoted both reversible and irreversible fouling. TEP are highly electronegative while alumina CM is positively charged which

  16. Enhancement of antioxidant activity of C-phycocyanin of Spirulina powder treated with supercritical fluid carbon dioxide

    Directory of Open Access Journals (Sweden)

    Monchai Dejsungkranont

    2017-10-01

    Full Text Available The functionality and activity of proteins can be modified by supercritical fluid CO2 (SCFCO2. The objectives of this study were to investigate the possibility of enhanced antioxidant activity of C-phycocyanin (C-PC proteins from light-harvested Spirulina maxima powder using the SCFCO2 pretreatment and to optimize the SCFCO2 pretreatment conditions enhancing the antioxidant activity of C-PC. The Taguchi method was used to determine the optimum conditions for the SCFCO2 pretreatment. The experimental factors were the pretreatment temperature, pressure, pretreatment mode (static, dynamic and conjugated and duration. The optimal conditions of SCFCO2 pretreatment were: 60 °C, 24.13 MPa and 60 min in static batch mode. Using these pretreatment conditions, the maximum antioxidant activity of C-PC from the treated residual biomass was 410.1 μmole trolox/mg, which was 1.7-fold higher than the untreated biomass (control. The factor that most affected the antioxidant activity of C-PC was temperature (59%. A high pretreatment temperature could damage C-PC, but promoted antioxidant activity. Of note is that this work was the first to explore SCFCO2 treatment enhancing the antioxidant activity of C-PC in Spirulina sp. powder. Keywords: Antioxidant activity, C-phycocyanin, Spirulina sp., Supercritical fluid carbon dioxide pretreatment, Taguchi method

  17. Removal of micro pollutants using activated biochars and powdered activated carbon in water

    Science.gov (United States)

    Kim, E.; Jung, C.; Han, J.; Son, A.; Yoon, Y.

    2015-12-01

    Recent studies have suggested that emerging micropollutants containing endocrine disrupting compounds (EDCs); bisphenol A, 17 α-ethinylestradiol, 17 β-estradiol and pharmaceuticals and personal care products (PPCPs); sulfamethoxazole, carbamazepine, ibuprofen, atenolol, benzophenone, benzotriazole, caffeine, gemfibrozil, primidone, triclocarban in water have been linked to ecological impacts, even at trace concentrations (sub ug/L). Adsorption with adsorbent such as activated carbon having a high-binding affinity has been widely used to eliminate various contaminants in the aqueous phase. Recently, an efficient treatment strategy for EDCs and PPCPs has been considered by using cost effective adsorption particularly with biochar in aqueous environmentIn this study, the objective of this study is to determine the removal of 13 target EDCs/PPCPs having different physicochemical properties by a biochar at various water quality conditions (pH (3.5, 7, and 10.5), background ions (NaCl, CaCl2, Na₂SO₄), ionic strength, natural organic matter (NOM)). The activated biochar produced in a laboratory was also characterized by using conventional analytical methods as well as advanced solid-state nuclear magnetic resonance (NMR) techniques, which answer how these properties determine the competitive adsorption characteristics and mechanisms of EDCs and PPCPs.The primary findings suggest that micropollutants can be removed more effectively by the biochar than the commercially available powdered activated carbon. At pH values below the pKa of each compound, the adsorption affinity toward adsorbents increased significantly with the pH, whereas the adsorption affinity decreased significantly at the pH above the pKa values. Na+ did not significantly impact adsorption, while increasing the concentration of Ca2+lead to increase in the adsorption of these micropollutants. NOM adsorption with humic acids on these adsorbents disturbed adsorption capacity of the target compounds as

  18. Super-bridges suspended over carbon nanotube cables

    Science.gov (United States)

    Carpinteri, Alberto; Pugno, Nicola M.

    2008-11-01

    In this paper the new concept of 'super-bridges', i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of ~3. Too large compliance and dynamic self-excited resonances could be avoided by additional strands, rendering the super-bridge anchored as a spider's cobweb. As an example, we have computed the limit main spans of the current existing 19 suspended-deck bridges longer than 1 km assuming them to have substituted their cables with carbon nanotube bundles (thus maintaining the same geometry, with the exception of the length) finding spans of up to ~6.3 km. We thus suggest that the design of the Messina bridge in Italy, which would require a main span of ~3.3 km, could benefit from the use of carbon nanotube bundles. We believe that their use represents a feasible and economically convenient solution. The plausibility of these affirmations is confirmed by a statistical analysis of the existing 100 longest suspended bridges, which follow a Zipf's law with an exponent of 1.1615: we have found a Moore-like (i.e. exponential) law, in which the doubling of the capacity (here the main span) per year is substituted by the factor 1.0138. Such a law predicts that the realization of the Messina bridge using conventional materials will only occur around the middle of the present century, whereas it could be expected in the near future if carbon nanotube bundles were used. A simple cost analysis concludes the paper.

  19. Super-bridges suspended over carbon nanotube cables

    International Nuclear Information System (INIS)

    Carpinteri, Alberto; Pugno, Nicola M

    2008-01-01

    In this paper the new concept of 'super-bridges', i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of ∼3. Too large compliance and dynamic self-excited resonances could be avoided by additional strands, rendering the super-bridge anchored as a spider's cobweb. As an example, we have computed the limit main spans of the current existing 19 suspended-deck bridges longer than 1 km assuming them to have substituted their cables with carbon nanotube bundles (thus maintaining the same geometry, with the exception of the length) finding spans of up to ∼6.3 km. We thus suggest that the design of the Messina bridge in Italy, which would require a main span of ∼3.3 km, could benefit from the use of carbon nanotube bundles. We believe that their use represents a feasible and economically convenient solution. The plausibility of these affirmations is confirmed by a statistical analysis of the existing 100 longest suspended bridges, which follow a Zipf's law with an exponent of 1.1615: we have found a Moore-like (i.e. exponential) law, in which the doubling of the capacity (here the main span) per year is substituted by the factor 1.0138. Such a law predicts that the realization of the Messina bridge using conventional materials will only occur around the middle of the present century, whereas it could be expected in the near future if carbon nanotube bundles were used. A simple cost analysis concludes the paper.

  20. Performance of Submerged Membrane Bioreactor Combined with Powdered Activated Carbon Addition for the Treatment of an Industrial Wastewater

    Directory of Open Access Journals (Sweden)

    Tri Widjaja

    2010-02-01

    Full Text Available Membrane technology is one of the alternative solutions to overcome industrial wastewater treatment developed nowadays. The addition of PAC (Powdered Activated Carbon in the activated sludge using Submerged Membrane Adsorption Hybrid Bioreactor (SMAHBR is expected to increase the organic material removal. The purpose of this study was to determine the performance of submerged membrane bioreactor and activated carbon adsorption capacity of organic materials in wastewater. This study used SIER (Surabaya Industrial Estate Rungkut – Surabaya, Indonesia waste as activated sludge operated at Mixed Liquor Suspended Solid (MLSS concentrations of 8000 and 15000 mg/l, and Chemical Oxygen Demand (COD concentrations of 1500, 2500 mg/l, Sludge Retention Time (SRT of 10;20; and 30 days and activated carbon variables of 0%; 2.5%; 5%; 7.5%; 10%. The results showed that the fouling potential occurred at high MLSS where the COD removal occurred at PAC addition of 10% reaching 91.86%. High Soluble Microbial Product (SMP accumulation (± 10 mg/l occurred in short SRT and high MLSS concentration. PAC addition resulted in decreased microorganisms in the reactor and better effluent of SMAHBR, as a result, the performance of the submerged membrane bioreactor would be restored.

  1. Preparation of granular activated carbons from composite of powder activated carbon and modified β-zeolite and application to heavy metals removal.

    Science.gov (United States)

    Seyedein Ghannad, S M R; Lotfollahi, M N

    2018-03-01

    Heavy metals are continuously contaminating the surface and subsurface water. The adsorption process is an attractive alternative for removing the heavy metals because of its low cost, simple operation, high efficiency, and flexible design. In this study, influences of β-zeolite and Cu-modified β-zeolite on preparation of granular activated carbons (GACs) from a composite of powder activated carbon (PAC), methylcellulose as organic binder, bentonite as inorganic binder, and water were investigated. A number of granular samples were prepared by controlling the weight percentage of binder materials, PAC and zeolites as a reinforcing adsorbent. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction techniques were employed to characterize zeolite, modified zeolite and produced GAC. The produced GACs were used as the adsorbent for removal of Zn +2 , Cd 2+ and Pb 2+ ions from aqueous solutions. The results indicated that the adsorption of metals ions depended on the pH (5.5) and contact time (30 min). Maximum adsorption of 97.6% for Pb 2+ , 95.9% for Cd 2+ and 91.1% for Zn +2 occurred with a new kind of GAC made of Cu-modified β-zeolite. The Zn +2 , Cd 2+ and Pb 2+ ions sorption kinetics data were well described by a pseudo-second order model for all sorbents. The Langmuir and Freundlich isotherm models were applied to analyze the experimental equilibrium data.

  2. Influence of Chemical and Physical Properties of Activated Carbon Powders on Oxygen Reduction and Microbial Fuel Cell Performance

    KAUST Repository

    Watson, Valerie J.

    2013-06-03

    Commercially available activated carbon (AC) powders made from different precursor materials (coal, peat, coconut shell, hardwood, and phenolic resin) were electrochemically evaluated as oxygen reduction catalysts and tested as cathode catalysts in microbial fuel cells (MFCs). AC powders were characterized in terms of surface chemistry and porosity, and their kinetic activities were compared to carbon black and platinum catalysts in rotating disk electrode (RDE) tests. Cathodes using the coal-derived AC had the highest power densities in MFCs (1620 ± 10 mW m-2). Peat-based AC performed similarly in MFC tests (1610 ± 100 mW m-2) and had the best catalyst performance, with an onset potential of Eonset = 0.17 V, and n = 3.6 electrons used for oxygen reduction. Hardwood based AC had the highest number of acidic surface functional groups and the poorest performance in MFC and catalysis tests (630 ± 10 mW m-2, Eonset = -0.01 V, n = 2.1). There was an inverse relationship between onset potential and quantity of strong acid (pKa < 8) functional groups, and a larger fraction of microporosity was negatively correlated with power production in MFCs. Surface area alone was a poor predictor of catalyst performance, and a high quantity of acidic surface functional groups was determined to be detrimental to oxygen reduction and cathode performance. © 2013 American Chemical Society.

  3. Improving the performance of membrane bioreactors by powdered activated carbon dosing with cost considerations.

    Science.gov (United States)

    Yang, W; Paetkau, M; Cicek, N

    2010-01-01

    Effects of powdered activated carbon (PAC) dosing on the overall performance of membrane bioreactors (MBR) were investigated in two bench-scale submerged MBRs. Positive impacts of PAC dosing on membrane fouling and the removal of 17beta-estradiol (E2) and 17alpha-ethyinylestradiol (EE2) were demonstrated over a six-month stable operational period. PAC dosing in the MBR increased the removal rates of E2 and EE2 by 3.4% and 15.8%, respectively. The average soluble extracellular polymeric substances (EPS) and colloidal total organic carbon (TOC) concentrations in the PAC-MBR sludge was 60.1% and 61.8% lower than the control MBR sludge, respectively. Lower soluble EPS and colloidal TOC concentrations in the PAC-MBR sludge resulted in a slower rate of trans-membrane pressure (TMP) increase during MBRs operation, which could prolong the lifespan of membranes. Cost assessment showed that PAC dosing could reduce the operating cost for membrane cleaning and/or membrane replacement by about 25%. The operating cost for PAC dosing could be offset by the benefit from its reducing the cost for membrane maintenance.

  4. A comparison of compacting and caking behaviour of carbonate-based washing powders

    OpenAIRE

    Leaper, M.C.; Leach, V.; Taylor, P.M.; Prime, D.C.

    2013-01-01

    Two types of sodium carbonate powder produced by spray drying (SD) and dry neutralisation (DN) were studied for their compaction properties using a uniaxial compression tester. Dry neutralised sodium carbonate showed a greater resistance to compression and also produced a weaker compact when compressed to 100kPa. Differential Scanning Calorimetry (DSC) showed that both types of powder were predominantly amorphous in nature. Moisture sorption measurements showed that both powders behaved in a ...

  5. Modelling Cr(VI) removal by a combined carbon-activated sludge system

    International Nuclear Information System (INIS)

    Orozco, A. Micaela Ferro; Contreras, Edgardo M.; Zaritzky, Noemi E.

    2008-01-01

    The combined carbon-activated sludge process has been proposed as an alternative to protect the biomass against toxic substances in wastewaters; however, the information about the effect of powdered-activated carbon (PAC) addition in activated sludge reactors for the treatment of wastewaters containing Cr(VI) is limited. The objectives of the present study were: (a) to evaluate the removal of hexavalent chromium by (i) activated sludge microorganisms in aerobic batch reactors, (ii) powdered-activated carbon, and (iii) the combined action of powdered-activated carbon and biomass; (b) to propose mathematical models that interpret the experimental results. Different Cr(VI) removal systems were tested: (S1) biomass (activated sludge), (S2) PAC, and (S3) the combined activated carbon-biomass system. A Monod-based mathematical model was used to describe the kinetics of Cr(VI) removal in the system S1. A first-order kinetics with respect to Cr(VI) and PAC respectively, was proposed to model the removal of Cr(VI) in the system S2. Cr(VI) removal in the combined carbon-biomass system (S3) was faster than both Cr(VI) removal using PAC or activated sludge individually. Results showed that the removal of Cr(VI) using the activated carbon-biomass system (S3) was adequately described by combining the kinetic equations proposed for the systems S1 and S2

  6. Joining of CBN abrasive grains to medium carbon steel with Ag-Cu/Ti powder mixture as active brazing alloy

    International Nuclear Information System (INIS)

    Ding, W.F.; Xu, J.H.; Shen, M.; Su, H.H.; Fu, Y.C.; Xiao, B.

    2006-01-01

    In order to develop new generation brazed CBN grinding wheels, the joining experiments of CBN abrasive grains and medium carbon steel using the powder mixture of Ag-Cu alloy and pure Ti as active brazing alloy are carried out at elevated temperature under high vacuum condition. The relevant characteristics of the special powder mixture, the microstructure of the interfacial region, which are both the key factors for determining the joining behavior among the CBN grains, the filler layer and the steel substrate, are investigated extensively by means of differential thermal analysis (DTA), scanning electron microscope (SEM) and energy dispersion spectrometer (EDS), as well X-ray diffraction (XRD) analysis. The results show that, similar to Ag-Cu-Ti filler alloy, Ag-Cu/Ti powder mixture exhibits good soakage capability to CBN grains during brazing. Moreover, Ti in the powder mixture concentrates preferentially on the surface of the grains to form a layer of needlelike Ti-N and Ti-B compounds by chemical metallurgic interaction between Ti, N and B at high temperature. Additionally, based on the experimental results, the brazing and joining mechanism is deeply discussed in a view of thermodynamic criterion and phase diagram of Ti-B-N ternary system

  7. Comparative studies of industrial grade carbon black powders

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Komal, E-mail: komalchawla.rs@gmail.com; Chauhan, Alok P. S., E-mail: chauhan.alok@gmail.com, E-mail: alok.chauhan@alumni.stonybrook.edu [Department of Physics and Material Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida-201307, UP, India. (India)

    2016-05-06

    Comparative studies of two dissimilar industrial grade Carbon Black (CB) powders (N375 and N405) were conducted. The structure, surface area and particle size are the three important characteristics of CB powder that determine their processability and application as filler in preparing rubber compounds. The powders were characterized for their structure using dibutyl phthalate absorption (DBPA), particle size via laser particle size analyzer and surface area by nitrogen adsorption method. The structural characterization showed that N405 had lower DBPA in comparison to N375, confirming low structure of N405 grade CB powder. It was observed from the particle size analysis that N375 was coarser than N405 grade CB. The total surface area values were determined by the BET method based on the cross sectional area of the nitrogen molecule. N375, a coarse grade CB powder with high structure, depicted less surface area as compared to N405.

  8. Supplementation of Citrus maxima Peel Powder Prevented Oxidative Stress, Fibrosis, and Hepatic Damage in Carbon Tetrachloride (CCl4) Treated Rats.

    Science.gov (United States)

    Chowdhury, Mohammed Riaz Hasan; Sagor, Md Abu Taher; Tabassum, Nabila; Potol, Md Abdullah; Hossain, Hemayet; Alam, Md Ashraful

    2015-01-01

    Citrus maxima peel is rich in natural phenolic compounds and has a long use in the traditional medicine. HPLC-DAD analysis on Citrus maxima peel powder exhibited the presence of various phenolic compounds such as caffeic acid and (-)-epicatechin. To determine the plausible hepatoprotective activity of Citrus maxima peel powder, we used carbon tetrachloride (CCl4) treated rat model. Liver damage in rats was confirmed by measuring the AST, ALT, and ALP enzyme activities. In addition, lipid peroxidation products (MDA), nitric oxide, advanced protein oxidation products level (APOP), and catalase activities were also analyzed along with the histological profiling for the inflammatory cell infiltration, collagen, and iron deposition in liver. Dietary supplementation of Citrus maxima peel powder exhibited significant reduction of serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. Moreover, Citrus maxima peel powder also showed a significant reduction of the oxidative stress markers (MDA, NO, and APOP level) and restored the catalase activity in CCl4 treated rats. Histological examination of the liver section revealed reduced inflammatory cells infiltration, collagen, and iron deposition in CCl4 treated rats. The results from this study demonstrated that Citrus maxima peel powder produced significant hepatoprotective action in CCl4 administered rats.

  9. Supplementation of Citrus maxima Peel Powder Prevented Oxidative Stress, Fibrosis, and Hepatic Damage in Carbon Tetrachloride (CCl4 Treated Rats

    Directory of Open Access Journals (Sweden)

    Mohammed Riaz Hasan Chowdhury

    2015-01-01

    Full Text Available Citrus maxima peel is rich in natural phenolic compounds and has a long use in the traditional medicine. HPLC-DAD analysis on Citrus maxima peel powder exhibited the presence of various phenolic compounds such as caffeic acid and (−-epicatechin. To determine the plausible hepatoprotective activity of Citrus maxima peel powder, we used carbon tetrachloride (CCl4 treated rat model. Liver damage in rats was confirmed by measuring the AST, ALT, and ALP enzyme activities. In addition, lipid peroxidation products (MDA, nitric oxide, advanced protein oxidation products level (APOP, and catalase activities were also analyzed along with the histological profiling for the inflammatory cell infiltration, collagen, and iron deposition in liver. Dietary supplementation of Citrus maxima peel powder exhibited significant reduction of serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. Moreover, Citrus maxima peel powder also showed a significant reduction of the oxidative stress markers (MDA, NO, and APOP level and restored the catalase activity in CCl4 treated rats. Histological examination of the liver section revealed reduced inflammatory cells infiltration, collagen, and iron deposition in CCl4 treated rats. The results from this study demonstrated that Citrus maxima peel powder produced significant hepatoprotective action in CCl4 administered rats.

  10. Larnite powders and larnite/silica aerogel composites as effective agents for CO{sub 2} sequestration by carbonation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A., E-mail: alberto.santos@uca.es [Departamento de Ciencias de la Tierra, Universidad de Cadiz, Puerto Real, 11510 Cadiz (Spain); Ajbary, M.; Morales-Florez, V. [Departamento de Fisica de la Materia Condensada, Universidad de Cadiz, Puerto Real, 11510 Cadiz (Spain); Kherbeche, A. [Universite Sidi Mohamed Ben Abdellah, Ecole Superieure de Technologie, Fes (Morocco); Pinero, M. [Departamento de Fisica Aplicada, Universidad de Cadiz, Puerto Real, 11510 Cadiz (Spain); Esquivias, L. [Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Instituto de Ciencias de Materiales de Sevilla (CSIC), Universidad de Sevilla, 41012 Sevilla (Spain)

    2009-09-15

    This paper presents the results of the carbonation reaction of two sample types: larnite (Ca{sub 2}SiO{sub 4}) powders and larnite/silica aerogel composites, the larnite acting as an active phase in a process of direct mineral carbonation. First, larnite powders were synthesized by the reaction of colloidal silica and calcium nitrate in the presence of ethylene glycol. Then, to synthesize the composites, the surface of the larnite powders was chemically modified with 3-aminopropyltriethoxysilane (APTES), and later this mixture was added to a silica sol previously prepared from tetraethylorthosilicate (TEOS). The resulting humid gel was dried in an autoclave under supercritical conditions for the ethanol. The textures and chemical compositions of the powders and composites were characterized.The carbonation reaction of both types of samples was evaluated by means of X-ray diffraction and thermogravimetric analysis. Both techniques confirm the high efficiency of the reaction at room temperature and atmospheric pressure. A complete transformation of the silicate into carbonate resulted after submitting the samples to a flow of pure CO{sub 2} for 15 min. This indicates that for this reaction time, 1 t of larnite could eliminate about 550 kg of CO{sub 2}. The grain size, porosity, and specific surface area are the factors controlling the reaction.

  11. Pilot-scale removal of pharmaceuticals in municipal wastewater: Comparison of granular and powdered activated carbon treatment at three wastewater treatment plants.

    Science.gov (United States)

    Kårelid, Victor; Larsson, Gen; Björlenius, Berndt

    2017-05-15

    Adsorption with activated carbon is widely suggested as an option for the removal of organic micropollutants including pharmaceutically active compounds (PhACs) in wastewater. In this study adsorption with granular activated carbon (GAC) and powdered activated carbon (PAC) was analyzed and compared in parallel operation at three Swedish wastewater treatment plants with the goal to achieve a 95% PhAC removal. Initially, mapping of the prevalence of over 100 substances was performed at each plant and due to low concentrations a final 22 were selected for further evaluation. These include carbamazepine, clarithromycin and diclofenac, which currently are discussed for regulation internationally. A number of commercially available activated carbon products were initially screened using effluent wastewater. Of these, a reduced set was selected based on adsorption characteristics and cost. Experiments designed with the selected carbons in pilot-scale showed that most products could indeed remove PhACs to the target level, both on total and individual basis. In a setup using internal recirculation the PAC system achieved a 95% removal applying a fresh dose of 15-20 mg/L, while carbon usage rates for the GAC application were much broader and ranged from carbon product. The performance of the PAC products generally gave better results for individual PhACs in regards to carbon availability. All carbon products showed a specific adsorption for a specific PhAC meaning that knowledge of the target pollutants must be acquired before successful design of a treatment system. In spite of different configurations and operating conditions of the different wastewater treatment plants no considerable differences regarding pharmaceutical removal were observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Treatment of coal gasification wastewater by membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system.

    Science.gov (United States)

    Jia, Shengyong; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Fang, Fang; Zhao, Qian

    2014-12-01

    A laboratory-scale membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system was developed to treat coal gasification wastewater to enhance the COD, total phenols (TPh), NH4+ removals and migrate the membrane fouling. Since the MBR–PAC system operated with PAC dosage of 4 g L−1, the maximum removal efficiencies of COD, TPh and NH4+ reached 93%, 99% and 63%, respectively with the corresponding influent concentrations of 2.27 g L−1, 497 mg L−1 and 164 mg N L−1; the PAC extraction efficiencies of COD, TPh and NH4+ were 6%, 3% and 13%, respectively; the transmembrane pressure decreased 34% with PAC after 50 d operation. The results demonstrate that PAC played a key role in the enhancement of biodegradability and mitigation of membrane fouling.

  13. Treatment of coke-oven wastewater with the powdered activated carbon-contact stabilization activated sludge process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Suidan, M.T.; Deady, M.A.; Gee, C.S.

    1983-11-01

    The objective of the study was to determine optimum parameters for the operation of an innovative process train used in the treatment of coke-over wastewater. The treatment process train consisted of a contact-stabilization activated sludge system with powdered activated carbon (PAC) addition, followed by activated sludge nitrification, followed by denitrification in an anoxic filter. The control and operating parameters evaluated during the study were: (a) the average mixed-liquor PAC concentration maintained in the contact-stabilization system, (b) the solids retention time practiced in the contact-stabilization system, and (c) the hydraulic detention time maintained in the contact aeration tank. Three identical treatement process trains were constructed and employed in this study. The coke-oven wastewater used for this investigation was fed to the treatment units at 30% strength. The first part of the study was devoted to determining the interactions between the mixed liquor PAC concentration and the solids retention time in the contact-stabilization tanks. Results showed that optimum overall system performance is attainable when the highest sludge age (30 day) and highest mixed liquor PAC concentration were practiced. During the second phase of the study, all three systems were operated at a 30 day solids retention time while different detention times of 1, 2/3 and 1/3 day were evaluated in the contact tank. PAC addition rates were maintained at the former levels and, consequently, reduced contact times entailed higher mixed liquor carbon concentrations. Once again, the system receiving the highest PAC addition rate of PAC exhibited the best overall performance. This system exhibited no deterioration in process performance as a result of decreased contact detention time. 72 references, 41 figures, 24 tables.

  14. The mid-Cretaceous super plume, carbon dioxide, and global warming

    Science.gov (United States)

    Caldeira, Ken; Rampino, Michael R.

    1991-01-01

    Carbon-dioxide releases associated with a mid-Cretaceous super plume and the emplacement of the Ontong-Java Plateau have been suggested as a principal cause of the mid-Cretaceous global warming. A carbonate-silicate cycle model is developed to quantify the possible climatic effects of these CO2 releases, utilizing four different formulations for the rate of silicate-rock weathering as a function of atmospheric CO2. CO2 emissions resulting from super-plume tectonics could have produced atmospheric CO2 levels from 3.7 to 14.7 times the modern preindustrial value of 285 ppm. Based on the temperature sensitivity to CO2 increases used in the weathering-rate formulations, this would cause a global warming of from 2.8 to 7.7 C over today's glogal mean temperature. Altered continental positions and higher sea level may have been contributed about 4.8 C to mid-Cretaceous warming. Thus, the combined effects of paleogeographic changes and super-plume related CO2 emissions could be in the range of 7.6 to 12.5 C, within the 6 to 14 C range previously estimated for mid-Cretaceous warming. CO2 releases from oceanic plateaus alone are unlikely to have been directly responsible for more than 20 percent of the mid-Cretaceous increase in atmospheric CO2.

  15. Cerebroprotective Actions of Triticum aestivum Linn Powder and Bauhinia purpurea Flower Powder in Surgically Induced Cerebral Infraction in Rats.

    Science.gov (United States)

    Annapurna, Akula; Vishala, Thonangi C; Bitra, Veera R; Rapaka, Deepthi; Shaik, Asmath

    2018-01-01

    The prime objective of this study is to evaluate the cerebroprotective actions of Triticum aestivum (wheatgrass) powder and Bauhinia purpurea flower (dev kanchan) powder against the experimentally induced global ischemia reperfusion injury in rats. In the first phase of the studies, 1 h before the surgical procedure, the Wistar rats were orally served with varied doses of wheatgrass powder (5, 10, 30, and 100 μg/kg) and Bauhinia flower powder (30, 100, 200, and 300 μg/kg), respectively. The ischemia was induced by 30-min bilateral carotid artery occlusion in succession to reperfusion for 4 h. It was proved that the wheatgrass powder and Bauhinia flower powder yielded a significant, dose-dependent cerebroprotection in terms of reduction in cerebral infarct size when compared with the control group. Coming to the second phase of the studies, a certain potential dose of 10 μg/kg of wheatgrass and 200 μg/kg of Bauhinia flower powders was selected keeping the protective action in view, and the animals were treated for 15 days. The major findings of the study are that wheatgrass and Bauhinia flower powders significantly augmented the magnitude of the antioxidant enzymes, viz., super oxide dismutase and catalase, and further reduced the levels of lipid peroxidation. The present study clearly showed that the wheatgrass powder and Bauhinia flower powder possess significant antioxidant properties that may act as a key ingredient in various ayurvedic preparations for the treatment of various diseases like cerebral ischemic reperfusion injury. The wheat grass contains high amount of bioflavonoids, alkaloids, SOD etc which are responsible for anti oxidant activity.The Bauhinia purpurea contains glycosides, flavonoids and also plays a major role in DPPH activity which is responsible for anti oxidant activity.The wheat grass (10 mg/kg) and bauhinia (200 mg/kg) significantly(P bauhinia (200 mg/kg) significantly (P <0.0001) reduced the lipid peroxidation (MDA) and increased SOD

  16. Quantitative measurement of carbon nanotubes released from their composites using thermal carbon analysis

    International Nuclear Information System (INIS)

    Ogura, I; Honda, K; Shigeta, M; Kotake, M; Uejima, M

    2015-01-01

    The ability of thermal carbon analysis to determine CNTs was evaluated in the presence of a polymer (Polystyrene, PS). Samples placed in an Au (Pt) foil boat were measured using a thermal-carbon analyzer, and the results were compared with gravimetric measurements of sample masses obtained using an ultra-microbalance. First, debris from the polymer without CNTs (i.e., PS debris) was analyzed. The amount of PS debris detected in the organic carbon (OC) fraction was found to be in good agreement with the gravimetrically measured mass of the PS debris, while the amount of pyrolyticallygenerated carbon soot detected in the elemental carbon (EC) fraction was negligible. Next, single-wall CNT (AIST/TASC Super-Growth) powder was analyzed, and the amount of the CNT powder detected in the EC fraction was found to be 95-96% of the gravimetrically measured mass of the CNT powder. Subsequently, a mixture of the PS debris and the CNT powder was analyzed, and the amounts of detected OC and EC were found to be comparable to the gravimetrically measured masses of the PS debris and the CNT powder, respectively. Finally, debris from 5 wt% CNT-PS composites was analyzed, and amounts of OC and EC detected were found to be approximately comparable to the estimated masses of the PS and the CNTs in the debris of CNT-PS composite, respectively. The results therefore indicate thermal carbon analysis is capable of determining CNTs in the presence of PS. (paper)

  17. Adsorption of clofibric acid and ketoprofen onto powdered activated carbon: effect of natural organic matter.

    Science.gov (United States)

    Gao, Yaohuan; Deshusses, Marc A

    2011-12-01

    The adsorption of two acidic pharmaceutically active compounds (PhACs), clofibric acid and ketoprofen, onto powdered activated carbon (PAC) was investigated with a particular focus on the influence of natural organic matter (NOM) on the adsorption of the PhACs. Suwannee River humic acids (SRHAs) were used as a substitute for NOM. Batch adsorption experiments were conducted to obtain adsorption kinetics and adsorption isotherms with and without SRHAs in the system. The adsorption isotherms and adsorption kinetics showed that the adsorption ofclofibric acid was not significantly affected by the presence of SRHAs at a concentration of 5 mg (as carbon) L(-1). An adsorption capacity of 70 to 140 mg g(-1) was observed and equilibrium was reached within 48 h. In contrast, the adsorption of ketoprofen was markedly decreased (from about 120 mg g(-1) to 70-100 mg g(-1)) in the presence of SRHAs. Higher initial concentrations of clofibric acid than ketoprofen during testing may explain the different behaviours that were observed. Also, the more hydrophobic ketoprofen molecules may have less affinity for PAC when humic acids (which are hydrophilic) are present. The possible intermolecular forces that could account for the different behaviour of clofibric acid and ketoprofen adsorption onto PAC are discussed. In particular, the relevance of electrostatic forces, electron donor-acceptor interaction, hydrogen bonding and London dispersion forces are discussed

  18. Synthesis of carbon nitride powder by selective etching of TiC0.3N0.7 in chlorine-containing atmosphere at moderate temperature

    International Nuclear Information System (INIS)

    Sui Jian; Lu Jinjun

    2010-01-01

    We reported the synthesis of carbon nitride powder by extracting titanium from single inorganic precursor TiC 0.3 N 0.7 in chlorine-containing atmosphere at ambient pressure and temperature not exceeding 500 deg. C. The TiC 0.3 N 0.7 crystalline structure acted as a template, supplying active carbon and nitrogen atoms for carbon nitride when it was destroyed in chlorination. X-ray diffraction data showed that the obtained carbon nitride powders were amorphous, which was in good agreement with transmission electron microscope analysis. The composition and structure of carbon nitride powders were analyzed by employing Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Results indicated that disorder structure was most likely for the carbon nitride powders and the N content depended greatly on the chlorination temperature. Thermal analysis in flowing N 2 indicated that the mass loss started from 300 deg. C and the complete decomposition occurred at around 650 deg. C, confirming the low thermal stability of the carbon nitride material.

  19. Electrostatic dry powder prepregging of carbon fiber

    Science.gov (United States)

    Throne, James L.; Sohn, Min-Seok

    1990-01-01

    Ultrafine, 5-10 micron polymer-matrix resin powders are directly applied to carbon fiber tows by passing then in an air or nitrogen stream through an electrostatic potential; the particles thus charged will strongly adhere to grounded carbon fibers, and can be subsequently fused to the fiber in a continuously-fed radiant oven. This electrostatic technique derived significant end-use mechanical property advantages from the obviation of solvents, binders, and other adulterants. Additional matrix resins used to produce prepregs to date have been PMR-15, Torlon 40000, and LaRC TPI.

  20. Bioturbation and dissolved organic matter enhance contaminant fluxes from sediment treated with powdered and granular activated carbon.

    Science.gov (United States)

    Kupryianchyk, D; Noori, A; Rakowska, M I; Grotenhuis, J T C; Koelmans, A A

    2013-05-21

    Sediment amendment with activated carbon (AC) is a promising technique for in situ sediment remediation. To date it is not clear whether this technique sufficiently reduces sediment-to-water fluxes of sediment-bound hydrophobic organic chemicals (HOCs) in the presence of bioturbators. Here, we report polychlorobiphenyl (PCB) pore water concentrations, fluxes, mass transfer coefficients, and survival data of two benthic species, for four treatments: no AC addition (control), powdered AC addition, granular AC addition and addition and subsequent removal of GAC (sediment stripping). AC addition decreased mass fluxes but increased apparent mass transfer coefficients because of dissolved organic carbon (DOC) facilitated transport across the benthic boundary layer (BBL). In turn, DOC concentrations depended on bioturbator activity which was high for the PAC tolerant species Asellus aquaticus and low for AC sensitive species Lumbriculus variegatus. A dual BBL resistance model combining AC effects on gradients, DOC facilitated transport and biodiffusion was evaluated against the data and showed how the type of resistance differs with treatment and chemical hydrophobicity. Data and simulations illustrate the complex interplay between AC and contaminant toxicity to benthic organisms and how differences in species tolerance affect mass fluxes from sediment to the water column.

  1. Removal of phenol by powdered activated carbon prepared from coal gasification tar residue.

    Science.gov (United States)

    Wang, Xiong-Lei; Shen, Jun; Niu, Yan-Xia; Wang, Yu-Gao; Liu, Gang; Sheng, Qing-Tao

    2018-03-01

    Coal gasification tar residue (CGTR) is a kind of environmentally hazardous byproduct generated in fixed-bed coal gasification process. The CGTR extracted by ethyl acetate was used to prepare powdered activated carbon (PAC), which is applied later for adsorption of phenol. The results showed that the PAC prepared under optimum conditions had enormous mesoporous structure, and the iodine number reached 2030.11 mg/g, with a specific surface area of 1981 m 2 /g and a total pore volume of 0.92 ml/g. Especially, without loading other substances, the PAC, having a strong magnetism, can be easily separated after it adsorbs phenol. The adsorption of phenol by PAC was studied as functions of contact time, temperature, PAC dosage, solution concentration and pH. The results showed a fast adsorption speed and a high adsorption capacity of PAC. The adsorption process was exothermic and conformed to the Freundlich models. The adsorption kinetics fitted better to the pseudo-second-order model. These results show that CGTR can be used as a potential adsorbent of phenols in wastewater.

  2. Chromium (Ⅵ) removal from aqueous solutions through powdered activated carbon countercurrent two-stage adsorption.

    Science.gov (United States)

    Wang, Wenqiang

    2018-01-01

    To exploit the adsorption capacity of commercial powdered activated carbon (PAC) and to improve the efficiency of Cr(VI) removal from aqueous solutions, the adsorption of Cr(VI) by commercial PAC and the countercurrent two-stage adsorption (CTA) process was investigated. Different adsorption kinetics models and isotherms were compared, and the pseudo-second-order model and the Langmuir and Freundlich models fit the experimental data well. The Cr(VI) removal efficiency was >80% and was improved by 37% through the CTA process compared with the conventional single-stage adsorption process when the initial Cr(VI) concentration was 50 mg/L with a PAC dose of 1.250 g/L and a pH of 3. A calculation method for calculating the effluent Cr(VI) concentration and the PAC dose was developed for the CTA process, and the validity of the method was confirmed by a deviation of <5%. Copyright © 2017. Published by Elsevier Ltd.

  3. Photocatalytic Activity and Characterization of Carbon-Modified Titania for Visible-Light-Active Photodegradation of Nitrogen Oxides

    Directory of Open Access Journals (Sweden)

    Chun-Hung Huang

    2012-01-01

    Full Text Available A variety of carbon-modified titania powders were prepared by impregnation method using a commercial available titania powder, Hombikat UV100, as matrix material while a range of alcohols from propanol to hexanol were used as precursors of carbon sources. Rising the carbon number of alcoholic precursor molecule, the modified titania showed increasing visible activities of NOx photodegradation. The catalyst modified with cyclohexanol exhibited the best activities of 62%, 62%, 59%, and 54% for the total NOx removal under UV, blue, green, and red light irradiation, respectively. The high activity with long wavelength irradiation suggested a good capability of photocatalysis in full visible light spectrum. Analysis of UV-visible spectrum indicated that carbon modification promoted visible light absorption and red shift in band gap. XPS spectroscopic analysis identified the existence of carbonate species (C=O, which increased with the increasing carbon number of precursor molecule. Photoluminescence spectra demonstrated that the carbonate species suppressed the recombination rate of electron-hole pair. As a result, a mechanism of visible-light-active photocatalyst was proposed according to the formation of carbonate species on carbon-modified TiO2.

  4. Super-capacitive electro-chemical performance of polymer blend gel polymer electrolyte (GPE) in carbon-based electrical double-layer capacitors

    International Nuclear Information System (INIS)

    Syahidah, S. Nuur; Majid, S.R.

    2013-01-01

    This study reports on the fabrication and comparative performance characteristics of a symmetrical electrical double-layer capacitor (EDLC) employed gel polymer electrolyte (GPE) assembled between carbon based electrodes. Three cells, A, B and C were fabricated using different composition of active materials (activated or porous carbon), binder (PVdF-HFP) and conductivity enhancer (super-P). The configuration of cell A: 0.9 porous carbon/0.1 PVdF-HFP, cell B: 0.45 activated carbon/0.45 porous carbon/0.1 PVdF-HFP and cell C: 0.8 activated carbon/0.1 super-P/0.1 PVdF-HFP. The GPE, comprising a poly(vinyl pyrrolidone) (PVP)/poly(vinylidene fluoride co-hexafluoroproplyne) (PVdF-HFP) blend complexed with magnesium triflate, Mg(CF 3 SO 3 ) 2 , was prepared by the solution casting technique at 60 °C. The physico-chemical properties of the GPEs were characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), linear sweep voltammetry (LSV) and cyclic voltammetry (CV). The ionic conductivity at the ambient temperature of the GPE is 2.16 × 10 −4 S cm −1 at 7.5 wt.% of Mg(CF 3 SO 3 ) 2 with a ∼2.6 V electro-chemical stability window. At the 1000th cycle, the specific capacitance, C s of cell A is 89 F g −1 while cell B and C are 63 and 49 F g −1 . Cell A shows excellent long-term cyclic stability (less than a 5% decrease in specific capacitance after 1000 cycles). The best operating voltage for cell A is 1.6 V with the specific capacitance 106 F g −1 after 500 cycles

  5. p-Nitrophenol removal by combination of powdered activated carbon adsorption and ultrafiltration - comparison of different operational modes.

    Science.gov (United States)

    Ivancev-Tumbas, Ivana; Hobby, Ralph; Küchle, Benjamin; Panglisch, Stefan; Gimbel, Rolf

    2008-09-01

    Ultrafiltration is classified as a low-pressure membrane technology which effectively removes particulate matter and microorganisms and to a certain extent dissolved organic matter (15-25%) and colour. The technology has been optimized and is becoming competitive compared to conventional processes for larger scale plant capacities. In combination with activated carbon it is an effective barrier regarding the removal of synthetic organic chemicals. Growing interest in ultrafiltration raises the question of better usage of the adsorption capacity of powdered activated carbon (PAC) used in combination with this low-pressure membrane technique. This paper presents a pilot plant study of different PAC dosing procedures within a combined hybrid membrane IN/OUT process for removal of p-nitrophenol (PNP) from water (c(0)=1mg/L) under real case conditions (e.g. usage of the same module for the whole duration of the experiment, backwashing with permeate water, no separate saturation of the membrane with substance without presence of carbon). p-Nitrophenol was chosen as an appropriate test substance to assess the efficiency of different operation modes. Dead-end and cross-flow filtration were compared with respect to different PAC dosing procedures: continuous dosing into a continuously stirred tank reactor (CSTR) in front of the module and direct dosing into the pipe in front of the module (continuous, single-pulse and multi-pulse dosing). There was no advantage in cross-flow mode over dead-end referring to PNP concentration in the permeate. Relating to the carbon dosing procedure, the best results were obtained for continuous PAC addition. The option of dosing directly into the pipe has the advantage of no additional tank being necessary. In the case of single-pulse dosing, the formation of a carbon layer on the membrane surface was assumed and an LDF model applied for a simplified estimation of the "breakthrough behaviour" in the thus formed "PAC filter layer".

  6. Recycling and characterization of carbon fibers from carbon fiber reinforced epoxy matrix composites by a novel super-heated-steam method.

    Science.gov (United States)

    Kim, Kwan-Woo; Lee, Hye-Min; An, Jeong-Hun; Chung, Dong-Chul; An, Kay-Hyeok; Kim, Byung-Joo

    2017-12-01

    In order to manufacture high quality recycled carbon fibers (R-CFs), carbon fiber-reinforced composite wastes were pyrolysed with super-heated steam at 550 °C in a fixed bed reactor for varying reaction times. The mechanical and surface properties of the R-CFs were characterized with a single fiber tensile test, interface shear strength (IFSS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The surface analysis showed that there was no matrix char residue on the fiber surfaces. The tensile strength and IFSS values of the R-CFs were 90% and 115% compared to those of virgin carbon fibers (V-CFs), respectively. The recycling efficiency of the R-CFs from the composites were strongly dependent on the pyrolysis temperature, reaction time, and super-heated steam feeding rate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Assessment of phosphate binding by sevelamer carbonate powder for oral suspension mixed in foods.

    Science.gov (United States)

    Hanus, Martin; Zhorov, Eugene; Brommage, Deborah; Plone, Melissa; Holmes-Farley, Stephen Randall

    2012-01-01

    This study investigated mixing sevelamer carbonate powder with foods and beverages other than water. Food samples, including applesauce, oatmeal, chicken, protein powder, scrambled eggs, ginger ale, and diet ginger ale, were subjected to an in vitro assay, and the difference in the amount of phosphate bound between samples pre-exposed to foods and samples where the drug was exposed to foods concurrently was determined Under these assay conditions, pre-exposure to sevelamer carbonate powder had no effect on the ability to bind phosphate. Clinical testing is needed to further evaluate this finding.

  8. Development and environmental applications of activated carbon cloths

    OpenAIRE

    Cukierman, Ana Lea

    2017-01-01

    Activated carbon cloths have received growing attention because they offer comparative advantages over the traditional powdered or granular forms of this well-known adsorbent, providing further potential uses for technological innovations in several fields. The present article provides an overview of research studies and advances concerned with the development of activated carbon cloths and their use as adsorbent in environmental applications, mostly reported in the last years. The influence ...

  9. Paramagnetic defects in hydrogenated amorphous carbon powders

    International Nuclear Information System (INIS)

    Keeble, D J; Robb, K M; Smith, G M; Mkami, H El; Rodil, S E; Robertson, J

    2003-01-01

    Hydrogenated amorphous carbon materials typically contain high concentrations of paramagnetic defects, the density of which can be quantified by electron paramagnetic resonance (EPR). In this work EPR measurements near 9.5, 94, and 189 GHz have been performed on polymeric and diamond-like hydrogenated amorphous carbon (a-C:H) powder samples. A similar single resonance line was observed at all frequencies for the two forms of a-C:H studied. No contributions to the spectrum from centres with resolved anisotropic g-values as reported earlier were detected. An increase in linewidth with microwave frequency was observed. Possible contributions to this frequency dependence are discussed

  10. Synthesis of high-performance Li2FeSiO4/C composite powder by spray-freezing/freeze-drying a solution with two carbon sources

    Science.gov (United States)

    Fujita, Yukiko; Iwase, Hiroaki; Shida, Kenji; Liao, Jinsun; Fukui, Takehisa; Matsuda, Motohide

    2017-09-01

    Li2FeSiO4 is a promising cathode active material for lithium-ion batteries due to its high theoretical capacity. Spray-freezing/freeze-drying, a practical process reported for the synthesis of various ceramic powders, is applied to the synthesis of Li2FeSiO4/C composite powders and high-performance Li2FeSiO4/C composite powders are successfully synthesized by using starting solutions containing both Indian ink and glucose as carbon sources followed by heating. The synthesized composite powders have a unique structure, composed of Li2FeSiO4 nanoparticles coated with a thin carbon layer formed by the carbonization of glucose and carbon nanoparticles from Indian ink. The carbon layer enhances the electrochemical reactivity of the Li2FeSiO4, and the carbon nanoparticles play a role in the formation of electron-conducting paths in the cathode. The composite powders deliver an initial discharge capacity of 195 and 137 mAh g-1 at 0.1 C and 1 C, respectively, without further addition of conductive additive. The discharge capacity at 1 C is 72 mAh g-1 after the 100th cycle, corresponding to approximately 75% of the capacity at the 2nd cycle.

  11. Effect of powdered activated carbon technology on short-cut nitrogen removal for coal gasification wastewater.

    Science.gov (United States)

    Zhao, Qian; Han, Hongjun; Xu, Chunyan; Zhuang, Haifeng; Fang, Fang; Zhang, Linghan

    2013-08-01

    A combined process consisting of a powdered activated carbon technology (PACT) and short-cut biological nitrogen removal reactor (SBNR) was developed to enhance the removal efficiency of the total nitrogen (TN) from the effluent of an upflow anaerobic sludge bed (UASB) reactor, which was used to treat coal gasification wastewater (CGW). The SBNR performance was improved with the increasing of COD and TP removal efficiency via PACT. The average removal efficiencies of COD and TP in PACT were respectively 85.80% and 90.30%. Meanwhile, the NH3-N to NO2-N conversion rate was achieved 86.89% in SBNR and the total nitrogen (TN) removal efficiency was 75.54%. In contrast, the AOB in SBNR was significantly inhibited without PACT or with poor performance of PACT in advance, which rendered the removal of TN. Furthermore, PAC was demonstrated to remove some refractory compounds, which therefore improved the biodegradability of the coal gasification wastewater. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. CO2 laser cladding of VERSAlloyTM on carbon steel with powder feeding

    International Nuclear Information System (INIS)

    Kim, Jae-Do; Kweon, Jin-Wook

    2007-01-01

    Laser cladding processing with metal powder feeding has been experimented on carbon steel with VERSAlloy TM . A special device for the metal powder feeding was designed and manufactured. By adopting proper cladding parameters, good clad layers and sound metallurgical bonding with the base metal were obtained. Analysis indicates that the micro hardness of clad layer and the heat-affected zone increased with increasing of cladding speed. The experimental results showed that VERSAlloy TM cladded well with carbon steel

  13. production and characterization of activated carbon from leather

    African Journals Online (AJOL)

    dell

    Powdered activated carbon (PAC) was prepared from leather buffing waste, sawdust and lignite by ... soil, air or water. (Baksi et al., 2006; ... anthracite and bituminous coal, lignite, lignocellulosic materials ..... waste water treatment: A review.

  14. Effect of Powdered Activated Carbon to Reduce Fouling in Membrane Bioreactors: A Sustainable Solution. Case Study

    Directory of Open Access Journals (Sweden)

    Giuseppe Mancini

    2013-04-01

    Full Text Available Membrane Bio Reactors (MBRs are mainly used for industrial wastewaters applications where their costs can be more easily afforded. High costs are basically due to energy consumption and membrane cleaning or replacement. Membrane fouling is responsible for reducing treated water production and increasing maintenance as well as operation costs. According to previous researches, the addition of Powdered Activated Carbon (PAC in high dosages could reduce membrane fouling; but such concentrations are economically unsustainable for operative conditions. A MBR pilot plant, fed by mixed liquor of a full-scale activated sludge process from a municipal wastewater treatment plant, was operated dosing low PAC concentrations (0, 2, 5, 10 and 20 mg·L−1, respectively. Experiments were also carried out at two different temperatures corresponding to summer and winter conditions. Results indicated that PAC addition was effective at the low dosages (2 and 5 mg·L−1 by reducing the permeate flux loss (from 16 up to 27%, respectively while higher PAC concentrations turns out in a useless cost increase.

  15. Effect of powdered activated carbon dosage on sludge properties and membrane bioreactor performance in a hybrid MBR-PAC system.

    Science.gov (United States)

    Zhang, Shi; Zuo, Xingtao; Xiong, Juan; Ma, Cong; Hu, Bo

    2017-12-22

    An improved insight into the effect of powdered activated carbon (PAC) on membrane fouling is crucial to the MBR performance. Sludge key property, soluble microbial products (SMP) and transmembrane pressure (TMP) were monitored. The membrane fouling rate in the MBRs was also analyzed based on TMP profile and resistance-in-series model. PAC reduced the membrane filtration resistance and significantly decreased the fouling rate. The sludge filterability was improved by extending the filtration time by almost twofold. PAC affected the SMP release and protein/polysaccharide (carbohydrate) was in a lower ratio. Fourier transform infrared (FTIR) analysis indicated that PAC decreased the impact of organic carbon, and reduced the proteins' and polysaccharides' absorption and deposition on the membrane surface and in the pores. The degree of reversible and irreversible fouling was related to the PAC content added into the MBRs. At the optimum dosage of 2 g/L, the results signified the PAC potential as a mitigation strategy of membrane fouling.

  16. [Ultra-Fine Pressed Powder Pellet Sample Preparation XRF Determination of Multi-Elements and Carbon Dioxide in Carbonate].

    Science.gov (United States)

    Li, Xiao-li; An, Shu-qing; Xu, Tie-min; Liu, Yi-bo; Zhang, Li-juan; Zeng, Jiang-ping; Wang, Na

    2015-06-01

    The main analysis error of pressed powder pellet of carbonate comes from particle-size effect and mineral effect. So in the article in order to eliminate the particle-size effect, the ultrafine pressed powder pellet sample preparation is used to the determination of multi-elements and carbon-dioxide in carbonate. To prepare the ultrafine powder the FRITSCH planetary Micro Mill machine and tungsten carbide media is utilized. To conquer the conglomeration during the process of grinding, the wet grinding is preferred. The surface morphology of the pellet is more smooth and neat, the Compton scatter effect is reduced with the decrease in particle size. The intensity of the spectral line is varied with the change of the particle size, generally the intensity of the spectral line is increased with the decrease in the particle size. But when the particle size of more than one component of the material is decreased, the intensity of the spectral line may increase for S, Si, Mg, or decrease for Ca, Al, Ti, K, which depend on the respective mass absorption coefficient . The change of the composition of the phase with milling is also researched. The incident depth of respective element is given from theoretical calculation. When the sample is grounded to the particle size of less than the penetration depth of all the analyte, the effect of the particle size on the intensity of the spectral line is much reduced. In the experiment, when grounded the sample to less than 8 μm(d95), the particle-size effect is much eliminated, with the correction method of theoretical α coefficient and the empirical coefficient, 14 major, minor and trace element in the carbonate can be determined accurately. And the precision of the method is much improved with RSD element, the fluorescence yield is low and the interference is serious. With the manual multi-layer crystal PX4, coarse collimator, empirical correction, X-ray spectrometer can be used to determine the carbon dioxide in the carbonate

  17. Cyanobacterial Treatment Options: Permanganate and Powdered Activated Carbon

    Science.gov (United States)

    This presentation will begin with a brief overview of drinking water treatment options for cyanobacteria and their toxins. The treatment discussion will focus on the impacts of permanganate addition to suspensions of toxin-producing Microcystis aeruginosa, followed by powdered ac...

  18. Dispersion of carbon nanotubes in hydroxyapatite powder by in situ chemical vapor deposition

    International Nuclear Information System (INIS)

    Li Haipeng; Wang Lihui; Liang, Chunyong; Wang Zhifeng; Zhao Weimin

    2010-01-01

    In the present work, we use chemical vapor deposition of methane to disperse carbon nanotubes (CNTs) within hydroxyapatite (HA) powder. The effect of different catalytic metal particles (Fe, Ni or Co) on the morphological and structural development of the powder and dispersion of CNTs in HA powder was investigated. The results show that the technique is effective in dispersing the nanotubes within HA powder, which simultaneously protects the nanotubes from damage. The results can have important and promising speculations for the processing of CNT-reinforced HA-matrix composites in general.

  19. Purifications of calcium carbonate and molybdenum oxide powders for neutrinoless double beta decay experiment, AMoRE

    International Nuclear Information System (INIS)

    Park, HyangKyu

    2015-01-01

    The AMoRE (Advanced Mo based Rare process Experiment) collaboration is going to use calcium molybdate crystals to search for neutrinoless double beta decay of 100 Mo isotope. In order to make the crystal, we use calcium carbonate and molybdenum oxide powders as raw materials. Therefore it is highly necessary to reduce potential sources for radioactive backgrounds such as U and Th in the powders. In this talk, we will present our studies for purification of calcium carbonate and molybdenum oxide powders

  20. Mechanism and kinetic considerations of TOC removal from the powdered activated carbon ozonation of diclofenac aqueous solutions.

    Science.gov (United States)

    Beltrán, Fernando J; Pocostales, J Pablo; Alvarez, Pedro M; Jaramillo, Josefa

    2009-09-30

    Ozonation of DCF in aqueous solution in the presence of powdered activated carbon (PAC) has been studied for mechanistic and kinetic purposes. The effects of gas flow rate, ozone gas concentration and initial TOC on the TOC elimination rate were then investigated. The use of PAC allows liquid-solid and internal diffusion mass transfer resistances being eliminated. Gas-liquid mass transfer resistance is also eliminated when ozonation is applied to DCF preozonated solutions. In the absence of mass transfer resistances a mechanism of reactions involving homogeneous and heterogeneous steps for TOC removal was proposed. From this mechanism a mathematical model constituted by mass balances of main species in water was established. Considerations about the changing nature of ozonation intermediates, as being promoters or inhibitors of ozone decomposition, is a key point to better predict the experimental concentrations of species present in this system.

  1. Copper-carbon and aluminum-carbon composites fabricated by powder metallurgy processes

    International Nuclear Information System (INIS)

    Silvain, Jean-François; Veillère, Amélie; Lu, Yongfeng

    2014-01-01

    The increase in both power and packing densities in power electronic devices has led to an increase in the market demand for effective heat-dissipating materials, with high thermal conductivity and thermal- expansion coefficient compatible with chip materials still ensuring the reliability of the power modules. In this context, metal matrix composites: carbon fibers and diamond-reinforced copper and aluminum matrix composites among them are considered very promising as a next generation of thermal-management materials in power electronic packages. These composites exhibit enhanced thermal properties compared to pure copper combined with lower density. This article presents the fabrication techniques of copper/carbon fibers and copper/diamond and aluminum/carbon fibers composite films by powder metallurgy and hot pressing. The thermal analyses clearly indicate that interfacial treatments are required in these composites to achieve high thermomechanical properties. Interfaces (through novel chemical and processing methods), when selected carefully and processed properly will form the right chemical/mechanical link between metal and carbon, enhancing all the desired thermal properties while minimizing the deleterious effect.

  2. Mechanochemical synthesis of fluorescent carbon dots from cellulose powders

    Science.gov (United States)

    Chae, Ari; Ram Choi, Bo; Choi, Yujin; Jo, Seongho; Kang, Eun Bi; Lee, Hyukjin; Park, Sung Young; In, Insik

    2018-04-01

    A novel mechanochemical method was firstly developed to synthesize carbon nanodots (CNDs) or carbon nano-onions (CNOs) through high-pressure homogenization of cellulose powders as naturally abundant resource depending on the treatment times. While CNDs (less than 5 nm in size) showed spherical and amorphous morphology, CNOs (10-50 nm in size) presented polyhedral shape, and onion-like outer lattice structure, graphene-like interlattice spacing of 0.36 nm. CNOs showed blue emissions, moderate dispersibility in aqueous media, and high cell viability, which enables efficient fluorescence imaging of cellular media.

  3. Synthesis, characterization and electrochemical performance of core/shell structured carbon coated silicon powders for lithium ion battery negative electrodes

    Directory of Open Access Journals (Sweden)

    Tuğrul Çetinkaya

    2017-06-01

    Full Text Available Surface of nano silicon powders were coated with amorphous carbon by pyrolysis of polyacronitrile (PAN polymer. Microstructural characterization of amorphous carbon coated silicon powders (Si-C were carried out using scanning electron microscopy (SEM and thickness of carbon coating is defined by transmission electron microscopy (TEM. Elemental analyses of Si-C powders were performed using energy dispersive X-ray spectroscopy (EDS. Structural and phase characterization of Si-C composite powders were investigated using X-ray diffractometer (XRD and Raman spectroscopy. Produced Si-C powders were prepared as an electrode on the copper current collector and electrochemical tests were carried out using CR2016 button cells at 200 mA/g constant current density. According to electrochemical test results, carbon coating process enhanced the electrochemical performance by reducing the problems stem from volume change and showed 770 mAh/g discharge capacity after 30 cycles.

  4. Effects of recirculation in a three-tank pilot-scale system for pharmaceutical removal with powdered activated carbon.

    Science.gov (United States)

    Kårelid, Victor; Larsson, Gen; Björlenius, Berndt

    2017-05-15

    The removal of pharmaceutically active compounds by powdered activated carbon (PAC) in municipal wastewater is a promising solution to the problem of polluted recipient waters. Today, an efficient design strategy is however lacking with regard to high-level overall, and specific, substance removal in the large scale. The performance of PAC-based removal of pharmaceuticals was studied in pilot-scale with respect to the critical parameters; contact time and PAC dose using one PAC product selected by screening in bench-scale. The goal was a minimum of 95% removal of the pharmaceuticals present in the evaluated municipal wastewater. A set of 21 pharmaceuticals was selected from an initial 100 due to their high occurrence in the effluent water of two selected wastewater treatment plants (WWTPs) in Sweden, whereof candidates discussed for future EU regulation directives were included. By using recirculation of PAC over a treatment system using three sequential contact tanks, a combination of the benefits of powdered and granular carbon performance was achieved. The treatment system was designed so that recirculation could be introduced to any of the three tanks to investigate the effect of recirculation on the adsorption performance. This was compared to use of the setup, but without recirculation. A higher degree of pharmaceutical removal was achieved in all recirculation setups, both overall and with respect to specific substances, as compared to without recirculation. Recirculation was tested with nominal contact times of 30, 60 and 120 min and the goal of 95% removal could be achieved already at the shortest contact times at a PAC dose of 10-15 mg/L. In particular, the overall removal could be increased even to 97% and 99%, at 60 and 120 min, respectively, when the recirculation point was the first tank. Recirculation of PAC to either the first or the second contact tank proved to be comparable, while a slightly lower performance was observed with recirculation to

  5. Improvement of deposition efficiency and control of hardness for cold-sprayed coatings using high carbon steel/mild steel mixture powder

    International Nuclear Information System (INIS)

    Ogawa, Kazuhiro; Amao, Satoshi; Yokoyama, Nobuyuki; Ootaki, Kousuke

    2011-01-01

    In this study, in order to make high carbon steel coating by cold spray technique, spray conditions such as carrier gas temperature and pressure etc. were investigated. And also, in order to improve deposition efficiency and control coating hardness of cold-sprayed high carbon steel, high carbon and mild steel mixed powder and its mechanical milled powder were developed and were optimized. By using the cold-spray technique, particle deposition of a high carbon steel was successful. Moreover, by applying mixed and mechanical milled powders, the porosity ratio was decreased and deposition efficiency was improved. Furthermore, using these powders, it is possible to control the hardness value. Especially, when using mechanical milled powder, it is very difficult to identify the interface between the coating and the substrate. The bonding between the coating and the substrate is thus considered to be excellent. (author)

  6. Powder metallurgy of turbine disc alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ingesten, N.G. (Dep. of Engineering Metals)

    1981-03-01

    The first part embraced a study of carbide precipitated in IN 100 and astrology powders. The powder was heat treated at temperatures between 950/sup 0/C and 1150/sup 0/C. After aging at 950-1100/sup 0/C the MC-carbides formed during atomization were replaced by M/sub 23/C/sub 6/-carbides. After 1150/sup 0/C treatments the MC carbides were present again. Precipitation comparable with that obtained in HIP:ed specimens was not observed at free particle surfaces. However, powder particles which had agglomerated during atomization often exhibited considerable precipitation at contiguous surfaces. Obviously, contact between the particles must occur if coarse precipitation at particle surfaces is to develop. Reduced PPB-precipitation was obtained by pre-heat- treatment of powder before compaction. It is suggested that the carbon otherwise available for PPB-precipitation forms carbides in the interior of the powder particles. The aim of the second part was to ..gamma..-strengthen a Co-based super-alloy (Co-15Cr-3Mo-5Ti). Here the Ti-addition gives a coherent and ordered ..gamma..-phase Co/sub 3/Ti. However, upon ageing the alloy is unstable in order to increase the stability modifications of the alloy were prepared by: leaving out the Mo-content, adding 10 % Ni and by decreasing the Ti-content to 4.2 %. In addition, the effect of enhanced grain size and of deformation was investigated. Significant reduction of the transformation rate was only obtained by decresing the Ti-content while deformation of the alloy greatly increased the transformation rate.(author).

  7. Impact strength of sintered astaloy CrM powders

    International Nuclear Information System (INIS)

    Kazior, J.; Ploszczak, J.; Nykiel, M.; Pieczonka, T.

    2003-01-01

    In this paper results of a series of impact tests on sintered Astaloy CrM powders alloys modified by boron are presented and discussed. Boron in different forms, i.e. as elemental boron powder, boron carbide B 4 C powder or mixture of boron and carbon elemental powders, was used in different weight percentage to activate sintering of Astaloy CrM powder and to increase hardenability, with aim of increasing impact strength in view of structural applications. (author)

  8. Analysis of low carbon super credit policy efficiency in European Union greenhouse gas emissions

    International Nuclear Information System (INIS)

    Álvarez, Roberto; Zubelzu, Sergio; Díaz, Guzmán; López, Alberto

    2015-01-01

    In this paper we address the current European Union's support policy for BEV (battery electric vehicles) manufacturing under the Super-credit modality, and its actual relationship with the reduction of carbon emissions derived from the use of battery electric vehicles (BEV). Particularly, we have estimated the BEV associated carbon emissions through the method provided by Intergovernmental Panel on Climate Change (IPCC). In this sense, we have employed a BEV model to investigate the BEV emissions by country in the EU according to the regional electricity mix. We additionally have accounted for the particularities of real-world driving, which further affects the results. We have employed a measure of driving aggressiveness by modifying the standard benchmarking driving cycle fostered by the European Union and of necessary application by vehicle manufacturers—the NEDC—to show that BEV emissions are not negligible when compared with internal combustion vehicles; mainly in urban environments. On the whole, in this paper we provide a revision framework of the Super Credits meant to support the increase of the BEV fleet in the European Union. In its current form, the Super-credits support policy is a constant ratio depending on the manufactured internal combustion vehicles. We claim, however, that they should depend on the BEV recipient country instead. By revising the European electricity mix, we demonstrate for instance that countries such as Poland, though indirectly, largely exceed the allowed limits of CO 2 emissions derived from the upstream generation of electricity required to load the BEV. - Highlights: • Super-credit support policy is aimed at promoting the manufacturing of BEV in the EU. • It does not account for upstream electricity generation in the BEV user country. • We analyze the generation emissions ensuing from the use of the BEV in EU countries. • We show that indirect carbon emissions in some countries exceed proposed targets.

  9. Scientific Opinion on the safety evaluation of the active substances, sodium carbonate peroxyhydrate coated with sodium carbonate and sodium silicate, bentonite, sodium chloride, sodium carbonate for use in active food contact materials

    OpenAIRE

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF)

    2013-01-01

    This scientific opinion of the Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety evaluation of the powder mixture of the active substances sodium carbonate peroxyhydrate coated with sodium carbonate and sodium silicate (FCM substance No 1009), bentonite (CAS No 1302-78-9, FCM No 393), sodium chloride (CAS No 7647-14-5, FCM No 985), sodium carbonate (CAS No 497-19-8, FCM No 1008) which are intended to be used as combined oxygen generator and carbon...

  10. Status report of BL08 superHRPD

    International Nuclear Information System (INIS)

    Torii, Shuki

    2010-01-01

    At the end of May in 2008, the first neutron was produced successfully from a spallation neutron source in Japan Proton Accelerator Research Complex (J-PARC). High resolution Bragg reflections were obtained using the Sirius diffractometer chamber at Super High Resolution Powder Diffractometer (SuperHARD) beam line at Materials and Life Science Experimental Facility (MLF). We started up quickly by using the existing Sirius chamber, and had succeeded in achieving resolution as Δd/d=0.035 %, the best among all the entire neutron powder diffractometers in the world. About 300 detectors had been installed in the backward detector bank, and several standard samples had been measured. Simultaneously, we were carrying out basic study to design and construct a new SuperHRPD chamber, and the Sirius chamber had been exchanged for new one in summer of 2009. In the design of a new chamber, a detector solid angle is increased, d-range/Q-range is expanded, and also has options of high-intensity mode and high-resolution mode with incident collimations. (author)

  11. Carbon Co-Deposition During Gas Reduction of Water-Atomized Fe-Cr-Mo Powder

    Directory of Open Access Journals (Sweden)

    Ali B.

    2017-06-01

    Full Text Available The water atomization of iron powder with a composition of Fe-3Cr-0.5Mo (wt.% at 1600°C and 150 bar creates an oxide layer, which in this study was reduced using a mixture of methane (CH4 and argon (Ar gas. The lowest oxygen content was achieved with a 100 cc/min flow rate of CH4, but this also resulted in a co-deposition of carbon due to the cracking of CH4. This carbon can be used directly to create high-quality, sinter hardenable steel, thereby eliminating the need for an additional mixing step prior to sintering. An exponential relationship was found to exist between the CH4 gas flow rate and carbon content of the powder, meaning that its composition can be easily controlled to suit a variety of different applications.

  12. Performance enhancement with powdered activated carbon (PAC) addition in a membrane bioreactor (MBR) treating distillery effluent

    International Nuclear Information System (INIS)

    Satyawali, Yamini; Balakrishnan, Malini

    2009-01-01

    This work investigated the effect of powdered activated carbon (PAC) addition on the operation of a membrane bioreactor (MBR) treating sugarcane molasses based distillery wastewater (spentwash). The 8 L reactor was equipped with a submerged 30 μm nylon mesh filter with 0.05 m 2 filtration area. Detailed characterization of the commercial wood charcoal based PAC was performed before using it in the MBR. The MBR was operated over 200 days at organic loading rates (OLRs) varying from 4.2 to 6.9 kg m -3 d -1 . PAC addition controlled the reactor foaming during start up and enhanced the critical flux by around 23%; it also prolonged the duration between filter cleaning. Operation at higher loading rates was possible and for a given OLR, the chemical oxygen demand (COD) removal was higher with PAC addition. However, biodegradation in the reactor was limited and the high molecular weight compounds were not affected by PAC supplementation. The functional groups on PAC appear to interact with the polysaccharide portion of the sludge, which may reduce its propensity to interact with the nylon mesh.

  13. Enhanced Recyclable Magnetized Palm Shell Waste-Based Powdered Activated Carbon for the Removal of Ibuprofen: Insights for Kinetics and Mechanisms.

    Directory of Open Access Journals (Sweden)

    Kien Tiek Wong

    Full Text Available A novel preparation method of magnetized palm shell waste-based powdered activated carbon (MPPAC, avg. size 112 μm was developed. The prepared MPPAC was assessed by several physicochemical analyses, and batch tests were performed for ibuprofen (IBP removal. Field emission scanning electron microscopy (FESEM and N2 gas isotherms revealed that magnetite and maghemite were homogeneous and deposited mostly on the surface of PPAC without a significant clogging effect on the micropores. Isotherm results showed that 3.8% Fe (w/w impregnated PPAC [MPPAC-Fe(3.8%] had about 2.2-fold higher maximum sorption capacity (157.3 mg g-1 and a 2.5-fold higher sorption density (0.23 mg m-2 than pristine PPAC. Both Fourier-transform infrared spectroscopy (FTIR and isotherm data indicated that the high sorption capacity and density of IBP by MPPAC was primarily attributable to donor-acceptor complexes with the C = O group and dispersive π-π interactions with the carbon surface. Based on kinetic and repeated adsorption tests, pore diffusion was the rate-limiting step, and MPPAC-Fe(3.8% had about 1.9~2.8- and 9.1~15.8-fold higher rate constants than MPPAC-Fe(8.6% and palm shell-waste granular activated carbon (PGAC, avg. size 621 μm, respectively. MPPAC showed almost eight fold greater re-adsorption capacity than PPAC due to a thermal catalytic effect of magnetite/maghemite.

  14. The Potential of Coconut Shell Powder (CSP) and Coconut Shell Activated Carbon (CSAC) Composites as Electromagnetic Interference (EMI) Absorbing Material

    International Nuclear Information System (INIS)

    Siti Nurbazilah Abdul Jabal; Seok, Y.B.; Hoon, W.F.

    2016-01-01

    Agriculture waste is potentially useful as an alternative material to absorb and attenuate electromagnetic interference (EMI). This research highlights the use of coconut shell powder (CSP) and coconut shell activated carbon (CSAC) as raw materials with epoxy resin and amine hardener composite to absorb microwave signals over frequency of 1 - 8 GHz. In order to investigate the suitability of these raw materials as EMI absorbing material, carbon composition of the raw materials is determined through CHNS Elemental Analysis. The surface morphology of the raw materials in term of porosity is investigated by using TM3000 Scanning Electron Microscope (SEM). The complex permittivity of the composites is determined by using high temperature dielectric probe in conjunction with Network Analyzer. From the result, the Carbon% of CSP and CSAC is 46.70 % and 84.28 % respectively. In term of surface morphology, the surface porosity of CSP and CSAC is in the range of 2 μm and 1 μm respectively. For the dielectric properties, the dielectric constant and the dielectric loss factor for CSP and CSAC is 4.5767 and 64.8307 and 1.2144 and 13.8296 respectively. The materials more potentially useful as substitute materials for electromagnetic interference (EMI) absorbing are discussed. (author)

  15. Processing and properties of carbon nanofibers reinforced epoxy powder composites

    International Nuclear Information System (INIS)

    Palencia, C.; Mazo, M. A.; Nistal, A.; Rubio, F.; Rubio, J.; Oteo, J. L.

    2011-01-01

    Commercially available CNFs (diameter 30–300 nm) have been used to develop both bulk and coating epoxy nanocomposites by using a solvent-free epoxy matrix powder. Processing of both types of materials has been carried out by a double-step process consisting in an initial physical premix of all components followed by three consecutive extrusions. The extruded pellets were grinded into powder and sieved. Carbon nanofibers powder coatings were obtained by electrostatic painting of the extruded powder followed by a curing process based in a thermal treatment at 200 °C for 25 min. On the other hand, for obtaining bulk carbon nanofibers epoxy composites, a thermal curing process involving several steps was needed. Gloss and mechanical properties of both nanocomposite coatings and bulk nanocomposites were improved as a result of the processing process. FE-SEM fracture surface microphotographs corroborate these results. It has been assessed the key role played by the dispersion of CNFs in the matrix, and the highly important step that is the processing and curing of the nanocomposites. A processing stage consisted in three consecutive extrusions has reached to nanocomposites free of entanglements neither agglomerates. This process leads to nanocomposite coatings of enhanced properties, as it has been evidenced through gloss and mechanical properties. A dispersion limit of 1% has been determined for the studied system in which a given dispersion has been achieved, as the bending mechanical properties have been increased around 25% compared with the pristine epoxy resin. It has been also demonstrated the importance of the thickness in the nanocomposite, as it involves the curing stage. The complex curing treatment carried out in the case of bulk nanocomposites has reached to reagglomeration of CNFs.

  16. Processing and properties of carbon nanofibers reinforced epoxy powder composites

    Science.gov (United States)

    Palencia, C.; Mazo, M. A.; Nistal, A.; Rubio, F.; Rubio, J.; Oteo, J. L.

    2011-11-01

    Commercially available CNFs (diameter 30-300 nm) have been used to develop both bulk and coating epoxy nanocomposites by using a solvent-free epoxy matrix powder. Processing of both types of materials has been carried out by a double-step process consisting in an initial physical premix of all components followed by three consecutive extrusions. The extruded pellets were grinded into powder and sieved. Carbon nanofibers powder coatings were obtained by electrostatic painting of the extruded powder followed by a curing process based in a thermal treatment at 200 °C for 25 min. On the other hand, for obtaining bulk carbon nanofibers epoxy composites, a thermal curing process involving several steps was needed. Gloss and mechanical properties of both nanocomposite coatings and bulk nanocomposites were improved as a result of the processing process. FE-SEM fracture surface microphotographs corroborate these results. It has been assessed the key role played by the dispersion of CNFs in the matrix, and the highly important step that is the processing and curing of the nanocomposites. A processing stage consisted in three consecutive extrusions has reached to nanocomposites free of entanglements neither agglomerates. This process leads to nanocomposite coatings of enhanced properties, as it has been evidenced through gloss and mechanical properties. A dispersion limit of 1% has been determined for the studied system in which a given dispersion has been achieved, as the bending mechanical properties have been increased around 25% compared with the pristine epoxy resin. It has been also demonstrated the importance of the thickness in the nanocomposite, as it involves the curing stage. The complex curing treatment carried out in the case of bulk nanocomposites has reached to reagglomeration of CNFs.

  17. Fractal analysis of granular activated carbons using isotherm data

    Energy Technology Data Exchange (ETDEWEB)

    Khalili, N.R.; Pan, M. [Illinois Institute of Technology, Chicago, IL (United States). Dept. of Chemical and Environmental Engineering; Sandi, G. [Argonne National Lab., IL (United States)

    1997-08-01

    Utilization of adsorption on solid surfaces was exercised for the first time in 1785. Practical application of unactivated carbon filters, and powdered carbon were first demonstrated in the American water treatment plant, and a municipal treatment plant in New Jersey, in 1883 and 1930, respectively. The use of activated carbon became widespread in the next few decades. At present, adsorption on carbons has a wide spread application in water treatment and removal of taste, odor, removal of synthetic organic chemicals, color-forming organics, and desinfection by-products and their naturally occurring precursors. This paper presents an analysis of the surface fractal dimension and adsorption capacity of a group of carbons.

  18. Effects of process parameters and ash on the adsorption properties of activated carbon from coals

    International Nuclear Information System (INIS)

    Gao, F.; Han, L.

    2013-01-01

    super-activated carbon was prepared from three representative shanxi coals, i.e. datong bituminous coal, yangquan anthracite and jincheng anthracite by KOH activation. The optimum parameters were obtained by comparing CCl/sub 4/ absorption values of activated carbon (ac). In addition, pristine coal and ac were deashed by acid washing, respectively. The effect of ash content on the adsorption properties of ac was studied. the results indicate that CCl/sub 4/ adsorption value of ac from yangquan anthracite with deashing treatment reaches up to 3301 mg/g when the activated temperature, activated time and ratio of alkali to carbon are 1830 degree C, 60 min and 5/1, respectively. (author)

  19. Enhancing anaerobic digestion of poultry blood using activated carbon

    Directory of Open Access Journals (Sweden)

    Maria José Cuetos

    2017-05-01

    Full Text Available The potential of using anaerobic digestion for the treatment of poultry blood has been evaluated in batch assays at the laboratory scale and in a mesophilic semi-continuous reactor. The biodegradability test performed on residual poultry blood was carried out in spite of high inhibitory levels of acid intermediaries. The use of activated carbon as a way to prevent inhibitory conditions demonstrated the feasibility of attaining anaerobic digestion under extreme ammonium and acid conditions. Batch assays with higher carbon content presented higher methane production rates, although the difference in the final cumulative biogas production was not as sharp. The digestion of residual blood was also studied under semi-continuous operation using granular and powdered activated carbon. The average specific methane production was 216 ± 12 mL CH4/g VS. This result was obtained in spite of a strong volatile fatty acid (VFA accumulation, reaching values around 6 g/L, along with high ammonium concentrations (in the range of 6–8 g/L. The use of powdered activated carbon resulted in a better assimilation of C3-C5 acid forms, indicating that an enhancement in syntrophic metabolism may have taken place. Thermal analysis and scanning electron microscopy (SEM were applied as analytical tools for measuring the presence of organic material in the final digestate and evidencing modifications on the carbon surface. The addition of activated carbon for the digestion of residual blood highly improved the digestion process. The adsorption capacity of ammonium, the protection this carrier may offer by limiting mass transfer of toxic compounds, and its capacity to act as a conductive material may explain the successful digestion of residual blood as the sole substrate.

  20. Some Properties of Carbon Fiber Reinforced Magnetic Reactive Powder Concrete Containing Nano Silica

    Directory of Open Access Journals (Sweden)

    Zain El-Abdin Raouf

    2016-08-01

    Full Text Available This study involves the design of 24 mixtures of fiber reinforced magnetic reactive powder concrete containing nano silica. Tap water was used for 12 of these mixtures, while magnetic water was used for the others. The nano silica (NS with ratios (1, 1.5, 2, 2.5 and 3 % by weight of cement, were used for all the mixtures. The results have shown that the mixture containing 2.5% NS gives the highest compressive strength at age 7 days. Many different other tests were carried out, the results have shown that the carbon fiber reinforced magnetic reactive powder concrete containing 2.5% NS (CFRMRPCCNS had higher compressive strength, modulus of rupture, splitting tension, stress in compression and strain in compression than the corresponding values for the carbon fiber reinforced nonmagnetic reactive powder concrete containing the same ratio of NS (CFRNRPCCNS. The percentage increase in these values for CFRMRPCCNS were (22.37, 17.96, 19.44, 6.44 and 25.8 % at 28 days respectively, as compared with the corresponding CFRNRPCCNS mixtures.

  1. High-purity tungsten powder: spheroidizing, properties and use in electronics

    International Nuclear Information System (INIS)

    Kapustin, V.I.; Burov, I.V.

    1999-01-01

    A study was made on the method of spheroidizing of tungsten powder in plasma of super high-frequency (SHF) discharge for formation of matrices, cathodes with regular porous structure. Kinetics of interphase interaction in the basic W-Y 2 O 3 cathode system was investigated. Possibility of using small additions of Re 2 Yintermetallic compound as an activator of emission-active component of cathodes was analyzed, High efficiency of plasma SHF-treatment with the use of laminar plasma flow is shown [ru

  2. Three exciting areas of experimental physical sciences : high temperature superconductors, metal clusters and super molecules of carbon

    International Nuclear Information System (INIS)

    Rao, C.N.

    1992-01-01

    The author has narrated his experience in carrying out research in three exciting areas of physical sciences. These areas are : high temperature superconductors, metal clusters and super molecules of carbon. (M.G.B.)

  3. Bacterial community evolutions driven by organic matter and powder activated carbon in simultaneous anammox and denitrification (SAD) process.

    Science.gov (United States)

    Ge, Cheng-Hao; Sun, Na; Kang, Qi; Ren, Long-Fei; Ahmad, Hafiz Adeel; Ni, Shou-Qing; Wang, Zhibin

    2018-03-01

    A distinct shift of bacterial community driven by organic matter (OM) and powder activated carbon (PAC) was discovered in the simultaneous anammox and denitrification (SAD) process which was operated in an anti-fouling submerged anaerobic membrane bio-reactor. Based on anammox performance, optimal OM dose (50 mg/L) was advised to start up SAD process successfully. The results of qPCR and high throughput sequencing analysis indicated that OM played a key role in microbial community evolutions, impelling denitrifiers to challenge anammox's dominance. The addition of PAC not only mitigated the membrane fouling, but also stimulated the enrichment of denitrifiers, accounting for the predominant phylum changing from Planctomycetes to Proteobacteria in SAD process. Functional genes forecasts based on KEGG database and COG database showed that the expressions of full denitrification functional genes were highly promoted in R C , which demonstrated the enhanced full denitrification pathway driven by OM and PAC under low COD/N value (0.11). Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Improving the performance of an aerobic membrane bioreactor (MBR) treating pharmaceutical wastewater with powdered activated carbon (PAC) addition.

    Science.gov (United States)

    Kaya, Yasemin; Bacaksiz, A Murat; Golebatmaz, Ugur; Vergili, Ilda; Gönder, Z Beril; Yilmaz, Gulsum

    2016-04-01

    In this study, the effects of organic loading rate (OLR) and the addition of powdered activated carbon (PAC) on the performance and membrane fouling of MBR were conducted to treat real pharmaceutical process wastewater. Over 145 days of operation, the MBR system was operated at OLRs ranging from 1 to 2 kg COD m(-3) day(-1) without sludge wasting. The addition of PAC provided an improvement in the flux, despite an increase in the OLR:PAC ratio. The results demonstrated that the hybrid PAC-MBR system maintained a reduced amount of membrane fouling and steadily increased the removal performance of etodolac. PAC addition reduced the deposition of extracellular polymeric substance and organic matter on the membrane surface and resulted an increase in COD removal even at higher OLRs with low PAC addition. Membrane fouling mechanisms were investigated using combined adsorption fouling models. Modified fouling index values and normalized mass transfer coefficient values indicated that predominant fouling mechanism was cake adsorption.

  5. Quantification of arsenic in activated carbon using particle induced X-ray emission

    International Nuclear Information System (INIS)

    Yadav, Nirbhay N.; Maheswaran, Saravanamuthu; Shutthanandan, Vaithiyalingam; Thevuthasan, Suntharampillai; Ngo, Huu H.; Vigneswaran, Saravanamuth

    2006-01-01

    To date, the trace elemental analysis of solids with inhomogeneous internal structure has been limited, particularly in the case of adsorbents. High-energy ion beam based particle induced X-ray emission (PIXE) is an ideal analytical tool suitable for simultaneous quantification of trace elements with high accuracy. In this study, PIXE was used to quantify arsenic in the adsorbents, granular activated carbon (GAC) and powder activated carbon (PAC). Pelletized and unmodified GAC and PAC samples were analyzed along with powder samples deposited on thin teflon filters. These sample preparation methods resulted in samples of various thicknesses and densities. PIXE measurements taken from these samples were compared to results from neutron activation analysis (NAA) and atomic absorption spectroscopy (AAS). There is a good agreement between the values from the NAA and pelletized PIXE measurements and some AAS measurements

  6. Oxygen-induced Decrease in the Equilibrium Adsorptive Capacities of Activated Carbons

    OpenAIRE

    Ovín Ania, María Concepción; Parra Soto, José Bernardo; Pis Martínez, José Juan

    2004-01-01

    Special attention was paid in this work to the role of surface chemistry in the adsorption of phenol and salicylic acid onto activated carbons. To this end, two commercial activated carbons (granular and powdered) were oxidised using ammonium peroxodisulphate [(NH4) 2S2O8] and nitric acid in different concentrations. The structural and chemical properties of the oxidised adsorbents were characterised via nitrogen adsorption isotherms measured at –196 ° C and Boehm titrations. Phenol adsorptio...

  7. MODEL OF HYDRODYNAMIC MIXING OF CARBONIC POWDERS IN VACUUMATOR, USED IN STEEL-MAKING OF RUP “BMZ”

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2005-01-01

    Full Text Available The mathematical model of the mixing and dissolving process of carbonic powder in a system '"vacuumator-bowl” under influence of circulating argon is offered. The spatial distribution of hydrodynamic currents at mixing of carbonic powder, received on the basis of computer calculations is presented. The character of distribution of hydrodynamic speeds of melt (circulating currents in industrial bowl and vacuumator for different time slots of mixing is determined. 

  8. Synthesis of Yttria-stabilized zirconia nanoparticles by decomposition of metal nitrates coated on carbon powder

    International Nuclear Information System (INIS)

    Jiang, S.; Stangle, G.C.; Amarakoon, V.R.; Schulze, W.A.

    1996-01-01

    Weakly agglomerated nanoparticles of yttria-stabilized zirconia (YSZ) were synthesized by a novel process which involved the decomposition of metal nitrates that had been coated on ultrafine carbon black powder, after which the carbon black was gasified. The use of ultrafine, high-surface-area carbon black powder apparently allowed the nanocrystalline oxide particles to form and remain separate from each other, after which the carbon black was gasified at a somewhat higher temperature. As a result, the degree of agglomeration was shown to be relatively low. The average crystallite size and the specific surface area of the as-synthesized YSZ nanoparticles were 5∼6 nm and 130 m 2 /g, respectively, for powder synthesized at 650 degree C. The as-synthesized YSZ nanoparticles had a light brown color and were translucent, which differs distinctly from conventional YSZ particles which are typically white and opaque. The mechanism of the synthesis process was investigated, and indicated that the gasification temperature had a direct effect on the crystallite size of the as-synthesized YSZ nanoparticles. High-density and ultrafine-grained YSZ ceramic articles were prepared by fast-firing, using a dwell temperature of 1250 degree C and a dwell time of two minutes or less. copyright 1996 Materials Research Society

  9. Simultaneous removal of ammonia and N-nitrosamine precursors from high ammonia water by zeolite and powdered activated carbon.

    Science.gov (United States)

    Xue, Runmiao; Donovan, Ariel; Zhang, Haiting; Ma, Yinfa; Adams, Craig; Yang, John; Hua, Bin; Inniss, Enos; Eichholz, Todd; Shi, Honglan

    2018-02-01

    When adding sufficient chlorine to achieve breakpoint chlorination to source water containing high concentration of ammonia during drinking water treatment, high concentrations of disinfection by-products (DBPs) may form. If N-nitrosamine precursors are present, highly toxic N-nitrosamines, primarily N-nitrosodimethylamine (NDMA), may also form. Removing their precursors before disinfection should be a more effective way to minimize these DBPs formation. In this study, zeolites and activated carbon were examined for ammonia and N-nitrosamine precursor removal when incorporated into drinking water treatment processes. The test results indicate that Mordenite zeolite can remove ammonia and five of seven N-nitrosamine precursors efficiently by single step adsorption test. The practical applicability was evaluated by simulation of typical drinking water treatment processes using six-gang stirring system. The Mordenite zeolite was applied at the steps of lime softening, alum coagulation, and alum coagulation with powdered activated carbon (PAC) sorption. While the lime softening process resulted in poor zeolite performance, alum coagulation did not impact ammonia and N-nitrosamine precursor removal. During alum coagulation, more than 67% ammonia and 70%-100% N-nitrosamine precursors were removed by Mordenite zeolite (except 3-(dimethylaminomethyl)indole (DMAI) and 4-dimethylaminoantipyrine (DMAP)). PAC effectively removed DMAI and DMAP when added during alum coagulation. A combination of the zeolite and PAC selected efficiently removed ammonia and all tested seven N-nitrosamine precursors (dimethylamine (DMA), ethylmethylamine (EMA), diethylamine (DEA), dipropylamine (DPA), trimethylamine (TMA), DMAP, and DMAI) during the alum coagulation process. Copyright © 2017. Published by Elsevier B.V.

  10. Effect of Carbon Content on the Properties of Iron-Based Powder Metallurgical Parts Produced by the Surface Rolling Process

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2018-01-01

    Full Text Available In recent years, the rolling densification process has become increasingly widely used to strengthen powder metallurgy parts. The original composition of the rolled powder metallurgy blank has a significant effect on the rolling densification technology. The present work investigated the effects of different carbon contents (0 wt. %, 0.2 wt. %, 0.45 wt. %, and 0.8 wt. % on the rolling densification. The selection of the raw materials in the surface rolling densification process was analyzed based on the pore condition, structure, hardness, and friction performance of the materials. The results show that the 0.8 wt. % carbon content of the surface rolling material can effectively improve the properties of iron-based powder metallurgy parts. The samples with 0.8 wt. % carbon have the highest surface hardness (340 HV0.1 and the lowest surface friction coefficient (0.35. Even if the dense layer depth is 1.13 mm, which is thinner than other samples with low carbon content, it also meets the requirements for powder metallurgy parts such as gears used in the auto industry.

  11. Industrially benign super-compressible piezoresistive carbon foams with predefined wetting properties: from environmental to electrical applications.

    Science.gov (United States)

    Pham, Tung Ngoc; Samikannu, Ajaikumar; Kukkola, Jarmo; Rautio, Anne-Riikka; Pitkänen, Olli; Dombovari, Aron; Lorite, Gabriela Simone; Sipola, Teemu; Toth, Geza; Mohl, Melinda; Mikkola, Jyri-Pekka; Kordas, Krisztian

    2014-11-06

    In the present work electrically conductive, flexible, lightweight carbon sponge materials derived from open-pore structure melamine foams are studied and explored. Hydrophobic and hydrophilic surface properties - depending on the chosen treatment conditions - allow the separation and storage of liquid chemical compounds. Activation of the carbonaceous structures substantially increases the specific surface area from ~4 m(2)g(-1) to ~345 m(2)g(-1), while retaining the original three-dimensional, open-pore structure suitable for hosting, for example, Ni catalyst nanoparticles. In turn the structure is rendered suitable for hydrogenating acetone to 2-propanol and methyl isobutyl ketone as well for growing hierarchical carbon nanotube structures used as electric double-layer capacitor electrodes with specific capacitance of ~40 F/g. Mechanical stress-strain analysis indicates the materials are super-compressible (>70% volume reduction) and viscoelastic with excellent damping behavior (loss of 0.69 ± 0.07), while piezoresistive measurements show very high gauge factors (from ~20 to 50) over a large range of deformations. The cost-effective, robust and scalable synthesis - in conjunction with their fascinating multifunctional utility - makes the demonstrated carbon foams remarkable competitors with other three-dimensional carbon materials typically based on pyrolyzed biopolymers or on covalently bonded graphene and carbon nanotube frameworks.

  12. Chloroanthraquinone as a grafted probe molecule to investigate grafting yield on carbon powder

    International Nuclear Information System (INIS)

    Le Comte, Annaïg; Brousse, Thierry; Bélanger, Daniel

    2016-01-01

    Spontaneous grafting of chloroanthraquinone (ClAQ) groups on Black Pearls carbon by reduction of the corresponding in-situ generated diazonium cations was successfully achieved. The presence of an halogen atom on the quinone molecule allowed the use of different spectroscopic characterization techniques to determine the accurate quinone content of the modified carbon. Electrochemical characterization highlighted that the presence of chlorine atom on the grafted molecule did not affect the electrochemical response or the grafting reaction efficiency. The amount of ClAQ molecules at the carbon surface after grafting was determined by cyclic voltammetry, together with thermogravimetric analysis coupled mass spectroscopy, X-ray photoelectron spectroscopy and elemental analysis. The ClAQ mass loadings estimated from the four techniques are in very good agreement and confirm that the grafted moieties are all electrochemically active and accessible. Finally, the grafting of quinone-type molecule using the reduction of diazonium cations does not affect the electroactivity of the grafted groups and cyclic voltammetry can be considered as a reliable technique to evaluate the mass loading of grafted quinone groups on porous carbon. Thus ClAQ can be used as a grafted probe molecule to investigate grafting yield on carbon powder, and this approach can be extended to functionalized electrodes used in an increasing number of electrochemical energy storage devices.

  13. Study of adsorption properties on lithium doped activated carbon materials

    International Nuclear Information System (INIS)

    Los, S.; Daclaux, L.; Letellier, M.; Azais, P.

    2005-01-01

    A volumetric method was applied to study an adsorption coefficient of hydrogen molecules in a gas phase on super activated carbon surface. The investigations were focused on getting the best possible materials for the energy storage. Several treatments on raw samples were used to improve adsorption properties. The biggest capacities were obtain after high temperature treatment at reduced atmosphere. The adsorption coefficient at 77 K and 2 MPa amounts to 3.158 wt.%. The charge transfer between lithium and carbon surface groups via the doping reaction enhanced the energy of adsorption. It was also found that is a gradual decrease in the adsorbed amount of H 2 molecules due to occupation active sites by lithium ions. (author)

  14. Successive carbon- and boron saturation of KhVG steel in powder mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Alimov, Yu A; Gordienko, S I

    1975-01-01

    Method of successive saturation of KhVG steel with carbon and boron in powder mixtures is described. After carbonization of steel in a charcoal carburator at 930 deg C during 3 hrs a domain of equiaxial large grains is formed there the latter representing carbides of Fe/sub 3/C and (Fe, M)/sub 3/C. The increase of duration of carbonization up to 5 hrs and above results in formation of a cement grid greatly impairing the mechanical properties of the metal. Carbonization is followed by borating in powdered technical boron carbide at 900 deg C for 4 hrs which ensures formation on the sample surface of a borated layer with depth up to 65 mkm covering the carbonized zone. As followed from metallographic and x-ray structural analysis, the borated layer consists of boride needles with complex composition (Fe, Cr, Mn)B. Oil hardening of carbonized KhVG steel from 850 deg C and low-temperature tempering at 180 deg C for 1 hr results in formation in the main metal of martensite-carbide structure and, respectively, in the decrease of the microhardness gradient between the diffusion layers, as compared with borated KhVG steel. Operation tests of strengthened matrices of preforming machines under the conditions of application of dynamic pressing forces up to 1500 kg Fce/cm/sup 2/ demonstrated that the cyclical strength of carboborated coverings is 2.0-3.0 times higher than that of borated ones. The method of carboborating is recommended for strengthening the details of stamp and press tools.

  15. Adsorption uptake of synthetic organic chemicals by carbon nanotubes and activated carbons

    Science.gov (United States)

    Brooks, A. J.; Lim, Hyung-nam; Kilduff, James E.

    2012-07-01

    Carbon nanotubes (CNTs) have shown great promise as high performance materials for adsorbing priority pollutants from water and wastewater. This study compared uptake of two contaminants of interest in drinking water treatment (atrazine and trichloroethylene) by nine different types of carbonaceous adsorbents: three different types of single walled carbon nanotubes (SWNTs), three different sized multi-walled nanotubes (MWNTs), two granular activated carbons (GACs) and a powdered activated carbon (PAC). On a mass basis, the activated carbons exhibited the highest uptake, followed by SWNTs and MWNTs. However, metallic impurities in SWNTs and multiple walls in MWNTs contribute to adsorbent mass but do not contribute commensurate adsorption sites. Therefore, when uptake was normalized by purity (carbon content) and surface area (instead of mass), the isotherms collapsed and much of the CNT data was comparable to the activated carbons, indicating that these two characteristics drive much of the observed differences between activated carbons and CNT materials. For the limited data set here, the Raman D:G ratio as a measure of disordered non-nanotube graphitic components was not a good predictor of adsorption from solution. Uptake of atrazine by MWNTs having a range of lengths and diameters was comparable and their Freundlich isotherms were statistically similar, and we found no impact of solution pH on the adsorption of either atrazine or trichloroethylene in the range of naturally occurring surface water (pH = 5.7-8.3). Experiments were performed using a suite of model aromatic compounds having a range of π-electron energy to investigate the role of π-π electron donor-acceptor interactions on organic compound uptake by SWNTs. For the compounds studied, hydrophobic interactions were the dominant mechanism in the uptake by both SWNTs and activated carbon. However, comparing the uptake of naphthalene and phenanthrene by activated carbon and SWNTs, size exclusion effects

  16. Adsorption uptake of synthetic organic chemicals by carbon nanotubes and activated carbons

    International Nuclear Information System (INIS)

    Brooks, A J; Kilduff, James E; Lim, Hyung-nam

    2012-01-01

    Carbon nanotubes (CNTs) have shown great promise as high performance materials for adsorbing priority pollutants from water and wastewater. This study compared uptake of two contaminants of interest in drinking water treatment (atrazine and trichloroethylene) by nine different types of carbonaceous adsorbents: three different types of single walled carbon nanotubes (SWNTs), three different sized multi-walled nanotubes (MWNTs), two granular activated carbons (GACs) and a powdered activated carbon (PAC). On a mass basis, the activated carbons exhibited the highest uptake, followed by SWNTs and MWNTs. However, metallic impurities in SWNTs and multiple walls in MWNTs contribute to adsorbent mass but do not contribute commensurate adsorption sites. Therefore, when uptake was normalized by purity (carbon content) and surface area (instead of mass), the isotherms collapsed and much of the CNT data was comparable to the activated carbons, indicating that these two characteristics drive much of the observed differences between activated carbons and CNT materials. For the limited data set here, the Raman D:G ratio as a measure of disordered non-nanotube graphitic components was not a good predictor of adsorption from solution. Uptake of atrazine by MWNTs having a range of lengths and diameters was comparable and their Freundlich isotherms were statistically similar, and we found no impact of solution pH on the adsorption of either atrazine or trichloroethylene in the range of naturally occurring surface water (pH = 5.7–8.3). Experiments were performed using a suite of model aromatic compounds having a range of π-electron energy to investigate the role of π–π electron donor–acceptor interactions on organic compound uptake by SWNTs. For the compounds studied, hydrophobic interactions were the dominant mechanism in the uptake by both SWNTs and activated carbon. However, comparing the uptake of naphthalene and phenanthrene by activated carbon and SWNTs, size exclusion

  17. Super-hierarchical porous carbons derived from mixed biomass wastes by a stepwise removal strategy for high-performance supercapacitors

    Science.gov (United States)

    Peng, Lin; Liang, Yeru; Dong, Hanwu; Hu, Hang; Zhao, Xiao; Cai, Yijing; Xiao, Yong; Liu, Yingliang; Zheng, Mingtao

    2018-02-01

    The synthesis and energy storage application of hierarchical porous carbons with size ranging from nano-to micrometres has attracted considerable attention all over the world. Exploring eco-friendly and reliable synthesis of hierarchical porous carbons for supercapacitors with high energy density and high power is still of ongoing challenge. In this work, we report the design and synthesis of super-hierarchical porous carbons with highly developed porosity by a stepwise removal strategy for high-rate supercapacitors. The mixed biomass wastes of coconut shell and sewage sludge are employed as raw material. The as-prepared super-hierarchical porous carbons present high surface areas (3003 m2 g-1), large pore volume (2.04 cm3 g-1), appropriate porosity, and outstanding electrochemical performance. The dependence of electrochemical performance on structural, textural, and functional properties of carbons engineered by various synthesis strategies is investigated in detail. Moreover, the as-assembled symmetrical supercapacitor exhibits high energy density of 25.4 Wh kg-1 at a power density of 225 W kg-1 and retains 20.7 Wh kg-1 even at a very high power of 9000 W kg-1. This work provides an environmentally benign strategy and new insights to efficiently regulate the porosity of hierarchical porous carbons derived from biomass wastes for energy storage applications.

  18. The Measurement of Thermal Conductivities of Silica and Carbon Black Powders at Different pressures by Thermal COnductivity Probe

    Institute of Scientific and Technical Information of China (English)

    X.G.Liang; X.S.Ge; 等

    1992-01-01

    This investigation was done to study the gas filled powder insulation and thermal conductivity probe for the measurent of thermal conductivity of powders.The mathematical analysis showed that the heat capacity of the probe itself and the thermal rsistance between the probe and powder must be considered .The authors developed a slender probe and measured the effective thermal conductivity of sillca and carbon black powders under a variety of conditions.

  19. Removal of cadmium and lead from water by activated carbon

    International Nuclear Information System (INIS)

    Abdel-Shafy, H.I.; Abdel-Sabour, M.F.; El-Gamal, I.M.; Abo-El-Wafa, O.

    1989-01-01

    Adsorption of cadmium and lead from water by carbon was studied using powdered or granular carbon. The studied water artificially contaminated by cadmium and lead amounting to 1 mg/dm 3 each. Batch as well as continuous system were carried out. The batch system was used to determine the time to maintain equilibrium followed by adsorption isotherm. Results obtained by using the powered carbon were found to match with Freundlich's equation where 1/n was 2.12 and 2.096 for Cd and Pb, respectively. Corresponding constants (K) were 4.2·10 -2 and 76.0·10 -2 . The amount of powdered activated carbon required to reduce residual Cd and Pb concentration to 0.01 mg/dm 3 for each are 26.98 and 2.86 mg, respectively. Similar batch system study was carried out for the granular carbon. When granular carbon was used in a continuous system, two different contact times, namely 10 to 20 min were examined. The results obtained showed that increasing the contact time from 10 to 20 min increases the metal to carbon removal efficiency. The overall results indicated that the breakthrough point for either Cd or Pb is the reverse of their adsorption as indicated by K value. (author). 22 refs, 10 figs, 7 tabs

  20. Method of measuring interface area of activated carbons in condensed phase

    Science.gov (United States)

    Dmitriyev, D. S.; Agafonov, D. V.; Kiseleva, E. A.; Mikryukova, M. A.

    2018-01-01

    In this work, we investigated the correlation between the heat of wetting of super-capacitor electrode material (activated carbon) with condensed phases (electrolytes based on homologous series of phosphoric acid esters) and the capacity of the supercapacitor. The surface area of the electrode-electrolyte interface was calculated according to the obtained correlations using the conventional formula for calculating the capacitance of a capacitor.

  1. Carbide Derived Carbon Super Capacitor Application

    Science.gov (United States)

    Appelgate, James; Bauer, Dave; Quirin, James; Lofland, S. E.; Hettinger, J. D.; Heon, M.; Gogotsi, Y.

    2010-02-01

    Supercapacitors can be applied into many different fields from nano-robots to high density energy storage. Growing TiC films from a know recipe and removing the transition metal element, Titanium, by chlorination leaves a carbon film that can then be applied as an electrode in a super capacitor. The problem is when the Titanium is removed from the film the stress induced by this process causes the films to fracture into isolated islands. The islands allow electrons to travel across them every easily, but there is no transfer of electrons from island to island. We present results of an investigation of a technique control the location of the fractures and use them to our benefit. Ideally, we want to create them to fracture in parallel lines. To force these fractures into straight lines we will purchase substrates with thermal SiO2 created on the surface of Si. Using an etching process we will removed a channel of SiO2 the same as the thickness of the TiC film we plan on growing. These channels will allow the fractures to form in a correlated way creating a straight line. )

  2. XAS AND XPS CHARACTERIZATION OF MERCURY BINDING ON BROMINATED ACTIVATED CARBON

    Science.gov (United States)

    Brominated powdered activated carbon sorbents have been shown to e quite effective for mercury capture when injected into the flue gas duct at coal-fired power plants and are especially useful when buring Western low-chlorine subbituminous coals. X-ray absorption spectroscopy (X...

  3. Perfluorooctane sulfonate adsorption on powder activated carbon: Effect of phosphate (P) competition, pH, and temperature.

    Science.gov (United States)

    Qian, Jin; Shen, Mengmeng; Wang, Peifang; Wang, Chao; Li, Kun; Liu, Jingjing; Lu, Bianhe; Tian, Xin

    2017-09-01

    Powdered activated carbon (PAC), as an adsorbent, was applied to remove perfluorooctane sulfonate (PFOS) from aqueous solution. Laboratory batch experiments were performed to investigate the influences of phosphate (P) competition, temperature, and pH for PFOS adsorption onto PAC. The results showed that higher temperature favored PFOS adsorption in single and binary systems. The kinetic data fitted very well to the pseudo second-order kinetic model. Thermodynamically, the endothermic enthalpy of the PFOS adsorption in single and binary systems were 125.07 and 21.25 kJ mol -1 , respectively. The entropy of the PFOS adsorption in single and binary systems were 0.479 and 0.092 kJ mol -1  K -1 , respectively. And the Gibbs constants were negative. These results indicated that the adsorption processes were spontaneous. The adsorption isotherms of PFOS agreed well with the Langmuir model. In the single system, PFOS adsorption decreased with increased pH value. The difference in the amount of PFOS adsorption between the single and binary systems increased at higher pH. Frustrated total internal reflection (FTIR) demonstrated that P competition increased the hydrophilicity of the PAC and the electrostatic repulsion between PFOS and PAC, then the PFOS adsorption amount decreased. It also demonstrated that, at higher temperature, increased PFOS adsorption was mainly due to the higher diffusion rate of PFOS molecules and greater number of active sites opened on the PAC surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Use of submerged anaerobic membrane bioreactor (SAMBR) containing powdered activated carbon (PAC) for the treatment of textile effluents.

    Science.gov (United States)

    Baêta, B E L; Ramos, R L; Lima, D R S; Aquino, S F

    2012-01-01

    This work investigated the use of submerged anaerobic membrane bioreactors (SAMBRs) in the presence and absence of powdered activated carbon (PAC) for the treatment of genuine textile wastewater. The reactors were operated at 35 °C with an HRT of 24 h and the textile effluent was diluted (1:10) with nutrient solution containing yeast extract as the source of the redox mediation riboflavin. The results showed that although both SAMBRs exhibited an excellent performance, the presence of PAC inside SAMBR-1 enhanced reactor stability and removal efficiency of chemical oxygen demand (COD), volatile fatty acids (VFA), turbidity and color. The median removal efficiencies of COD and color in SAMBR-1 were, 90 and 94% respectively; whereas for SAMBR-2 (without PAC) these values were 79 and 86%, In addition, the median values of turbidity and VFA were 8 NTU and 8 mg/L for SAMBR-1 and 14 NTU and 26 mg/L for SAMBR-2, indicating that the presence of PAC inside SAMBR-1 led to the production of an anaerobic effluent of high quality regarding such parameters.

  5. Quantitative detection of powdered activated carbon in wastewater treatment plant effluent by thermogravimetric analysis (TGA).

    Science.gov (United States)

    Krahnstöver, Therese; Plattner, Julia; Wintgens, Thomas

    2016-09-15

    For the elimination of potentially harmful micropollutants, powdered activated carbon (PAC) adsorption is applied in many wastewater treatment plants (WWTP). This holds the risk of PAC leakage into the WWTP effluent and desorption of contaminants into natural water bodies. In order to assess a potential PAC leakage, PAC concentrations below several mg/L have to be detected in the WWTP effluent. None of the methods that are used for water analysis today are able to differentiate between activated carbon and solid background matrix. Thus, a selective, quantitative and easily applicable method is still needed for the detection of PAC residues in wastewater. In the present study, a method was developed to quantitatively measure the PAC content in wastewater by using filtration and thermogravimetric analysis (TGA), which is a well-established technique for the distinction between different solid materials. For the sample filtration, quartz filters with a temperature stability up to 950 °C were used. This allowed for sensitive and well reproducible measurements, as the TGA was not affected by the presence of the filter. The sample's mass fractions were calculated by integrating the mass decrease rate obtained by TGA in specific, clearly identifiable peak areas. A two-step TGA heating method consisting of N2 and O2 atmospheres led to a good differentiation between PAC and biological background matrix, thanks to the reduction of peak overlapping. A linear correlation was found between a sample's PAC content and the corresponding peak areas under N2 and O2, the sample volume and the solid mass separated by filtration. Based on these findings, various wastewater samples from different WWTPs were then analyzed by TGA with regard to their PAC content. It was found that, compared to alternative techniques such as measurement of turbidity or total suspended solids, the newly developed TGA method allows for a quantitative and selective detection of PAC concentrations down to 0

  6. Hepatoprotective activity of Chhit-Chan-Than extract powder against carbon tetrachloride-induced liver injury in rats

    Directory of Open Access Journals (Sweden)

    Yi-Chun Lin

    2014-06-01

    Full Text Available The capability of Chhit-Chan-Than extract powder (CCTEP, 10% aqueous Ocimum gratissimum L. extract to protect against carbon tetrachloride (CCl4-induced oxidative stress and hepatotoxicity in vivo was investigated. Wistar rats were divided into five groups. Group A was a normal control group given only vehicle; Group B, the hepatotoxic group, was injected intraperitoneally twice a week with repeated 8% CCl4/olive oil (0.1 mL/100 g of body weight; Groups C–E, extract-treated groups received CCl4 and different doses of CCTEP (100 mg/kg and 200 mg/kg or silymarin (200 mg/kg of body weight daily by gavage for 8 weeks, respectively. The results showed that the CCl4-induced histopathogical changes may be prevented by CCTEP through reducing the intercellular collogen stack, dropping blood serum alanine aminotransferase and aspartate aminotransferase levels, and restoring the catalase activity and glutathione content. The hepatoprotective properties were further confirmed by the marked improvement in histopathological examination and by quantitative steatosis-fibrosis scoring. The above results suggest that CCTEP is able to prevent the liver inflammation and fibrosis induced by repeated CCl4 administration, and the hepatoprotective effects might be correlated partly with its antioxidant and free radical scavenging effects.

  7. Physicochemical and Antioxidant Activities of Spray-dried Pitaya Fruit Powder

    Science.gov (United States)

    Li, Guopeng; Liu, Yangyang; Lin, Lijing; Li, Jihua

    2018-01-01

    Pitaya commonly known as dragon fruit is very popular in China due to its intense color, constituent minerals, vitamins, and antioxidant properties. In the present study, physiochemical properties and antioxidant activities of fruit powder from two pitaya cultivars (namely red flesh and white flesh) and fruit peel were observed. Compared with the fruit powder of fruit flesh, the fruit powder made from fruit peel showed a higher antioxidant activity. The current study provides insights to produce spray-dried pitaya fruit powders that could potentially be used as functional food ingredients in various food fields.

  8. Prelithiation of silicon-carbon nanotube anodes for lithium ion batteries by stabilized lithium metal powder (SLMP).

    Science.gov (United States)

    Forney, Michael W; Ganter, Matthew J; Staub, Jason W; Ridgley, Richard D; Landi, Brian J

    2013-09-11

    Stabilized lithium metal powder (SLMP) has been applied during battery assembly to effectively prelithiate high capacity (1500-2500 mAh/g) silicon-carbon nanotube (Si-CNT) anodes, eliminating the 20-40% first cycle irreversible capacity loss. Pressure-activation of SLMP is shown to enhance prelithiation and enable capacity matching between Si-CNT anodes and lithium nickel cobalt aluminum oxide (NCA) cathodes in full batteries with minimal added mass. The prelithiation approach enables high energy density NCA/Si-CNT batteries achieving >1000 cycles at 20% depth-of-discharge.

  9. Impedance measurement and modelling of super-capacitors for railway applications

    Energy Technology Data Exchange (ETDEWEB)

    Hammar, A.; Chabas, J. [Societe Nationale des Chemins de fer Francais (SNCF), Dir. de la Recherche, 75 - Paris (France); Coquery, G.; Lallemand, R. [Institut National de Recherche sur les Transports et leur Securite (INRETS), Lab. des Technologies Nouvelles, 94 - Arcueil (France); Rojat, G.; Venet, P. [Lyon-1 Univ. Claude Bernard, CEGELY, 69 - Villeurbanne (France)

    2004-07-01

    Railways and electrical traction systems require high power rates to achieve their operating performances. Systems of power supply based on super-capacitors should offer high power density along with good energy efficiency and expected operating safety. We investigate general behaviours of super-capacitors with two powerful methods of analysis. The first is constant charge/discharge current at high level value (500 A), the second is impedance spectroscopy which leads to the acquisition of a set of parameters that are considered sufficient to describe general properties of super-capacitor, in particular the state of health and the available energy in any operating conditions. An electrical circuit model is defined for super-capacitors based on activated carbon and organic electrolyte. It takes into account the dependence of super-capacitor to voltage and current. The mixture of data of the two methods permits to obtain a representative model for power applications. Matlab/Simulink simulations are shown to verify the validity of the model. (authors)

  10. Textural and chemical properties of zinc chloride activated carbons prepared from pistachio-nut shells

    Energy Technology Data Exchange (ETDEWEB)

    Ting, Yang [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Lua, Aik Chong [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2006-12-10

    The effects of activation temperature on the textural and chemical properties of the activated carbons prepared from pistachio-nut shells using zinc chloride activation under both inert nitrogen gas atmosphere and vacuum condition were studied. Relatively low temperature of 400 deg. C was beneficial for the development of pore structures. Too high an activation temperature would lead to sintering of volatiles and shrinkage of the carbon structure. The microstructures and microcrystallinity of the activated carbons prepared were examined by scanning electron microscope and powder X-ray diffraction techniques, respectively, while Fourier transform infrared spectra determined the changes in the surface functional groups at the various stages of preparation.

  11. Textural and chemical properties of zinc chloride activated carbons prepared from pistachio-nut shells

    International Nuclear Information System (INIS)

    Yang Ting; Lua, Aik Chong

    2006-01-01

    The effects of activation temperature on the textural and chemical properties of the activated carbons prepared from pistachio-nut shells using zinc chloride activation under both inert nitrogen gas atmosphere and vacuum condition were studied. Relatively low temperature of 400 deg. C was beneficial for the development of pore structures. Too high an activation temperature would lead to sintering of volatiles and shrinkage of the carbon structure. The microstructures and microcrystallinity of the activated carbons prepared were examined by scanning electron microscope and powder X-ray diffraction techniques, respectively, while Fourier transform infrared spectra determined the changes in the surface functional groups at the various stages of preparation

  12. Super-activating Quantum Memory with Entanglement

    OpenAIRE

    Guan, Ji; Feng, Yuan; Ying, Mingsheng

    2017-01-01

    Noiseless subsystems were proved to be an efficient and faithful approach to preserve fragile information against decoherence in quantum information processing and quantum computation. They were employed to design a general (hybrid) quantum memory cell model that can store both quantum and classical information. In this Letter, we find an interesting new phenomenon that the purely classical memory cell can be super-activated to preserve quantum states, whereas the null memory cell can only be...

  13. Functionalization of super-aligned carbon nanotube film using hydrogen peroxide solution and its application in copper electrodeposition.

    Science.gov (United States)

    Xiong, Lunqiao; Shuai, Jing; Hou, Zecheng; Zhu, Lin; Li, Wenzhen

    2017-07-15

    In order to make super-aligned carbon nanotubes (SACNT) homogeneously spread in electrolytes, a swift and effective method was devised for surface functionalization of SACNT film by ohmic heating using hydrogen peroxide solution. Controllable generation of defects and notable graft of oxygen functional groups on the sidewall of SACNTs were induced as proven by X-ray photoelectron spectroscopy and Raman spectroscopy. Differently from the harsh wet chemical oxidation, the super-aligned morphology and structural integrity of carbon nanotubes in the SACNT film were found to be well preserved by electron microscopy analysis. The functionalized treatment can remove extraneous material contaminating SACNT film and improve its conductivity. The grafting of polar ionizable groups has been proved to effectively eliminate the agglomeration of SACNTs. When the oxidized SACNT film was used as host material for electrodeposition of copper, the composite film of well-bonded SACNTs and Cu was successfully prepared. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Effect of powdered activated carbon (PAC) on MBR performance and effluent trihalomethane formation: At the initial stage of PAC addition.

    Science.gov (United States)

    Gao, Yue; Ma, Defang; Yue, Qinyan; Gao, Baoyu; Huang, Xia

    2016-09-01

    In this study, the MBR was used to treat municipal wastewater for reuse. Effects of powdered activated carbon (PAC) addition on MBR system in terms of effluent water quality, trihalomethane (THM) formation and membrane organic fouling tendency of MBR sludge supernatant at the initial stage of PAC addition were investigated. Effects of chlorine dose and contact time on THM formation and speciation were also studied. PAC addition enhanced the removal of organic matters, especially aromatic components, which improved the UV254 removal rate from 34% to 83%. PAC addition greatly reduced the membrane organic fouling tendency of MBR sludge supernatant. PAC addition reduced the MBR effluent trihalomethane formation potential (THMFP) from 351.29 to 241.95μg/L, while increased THM formation reactivity by 42%. PAC addition enhanced the formation of higher toxic bromine-containing THMs. High chlorine dose and contact time resulted in higher THM formation but lower proportion of bromine-containing THMs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The use of activated carbons for removing organic matter from groundwater

    Directory of Open Access Journals (Sweden)

    Kaleta Jadwiga

    2017-09-01

    Full Text Available The article presents research results of the introduction of powdery activated carbon to the existing technological system of the groundwater treatment stations in a laboratory, pilot plant and technical scale. The aim of the research was to reduce the content of organic compounds found in the treated water, which create toxic organic chlorine compounds (THM after disinfection with chlorine. Nine types of powdery active carbons were tested in laboratory scale. The top two were selected for further study. Pilot plant scale research was carried out for the filter model using CWZ-30 and Norit Sa Super carbon. Reduction of the organic matter in relation to the existing content in the treated water reached about 30%. Research in technical scale using CWZ-30 carbon showed a lesser efficiency with respect to laboratory and pilot-plant scale studies. The organic matter decreased by 15%. Since filtration is the last process before the individual disinfection, an alternative solution is proposed, i.e. the second stage of filtration with a granular activated carbon bed, operating in combined sorption and biodegradation processes. The results of tests carried out in pilot scale were fully satisfactory with the effectiveness of 70–100%.

  16. Factors causing PAC cake fouling in PAC-MF (powdered activated carbon-microfiltration) water treatment systems.

    Science.gov (United States)

    Zhao, P; Takizawa, S; Katayama, H; Ohgaki, S

    2005-01-01

    Two pilot-scale powdered activated carbon-microfiltration (PAC-MF) reactors were operated using river water pretreated by a biofilter. A high permeate flux (4 m/d) was maintained in two reactors with different particle sizes of PAC. High concentration (20 g/L) in the PAC adsorption zone demonstrated 60-80% of organic removal rates. Analysis on the PAC cake fouling demonstrated that attached metal ions play more important role than organic matter attached on PAC to the increase of PAC cake resistance. Effects of factors which may cause PAC cake fouling in PAC-MF process were investigated and evaluated by batch experiments, further revealing that small particulates and metal ions in raw water impose prominent influence on the PAC cake layer formation. Fe (II) precipitates after being oxidized to Fe (III) during PAC adsorption and thus Fe(ll) colloids display more significant effect than other metal ions. At a high flux, PAC cake layer demonstrated a higher resistance with larger PAC due to association among colloids, metals and PAC particles, and easy migration of small particles in raw water into the void space in the PAC cake layer. Larger PAC possesses much more non-uniform particle size distribution and larger void space, making it easier for small colloids to migrate into the voids and for metal ions to associate with PAC particles by bridge effect, hence speeding up and intensifying the of PAC cake fouling on membrane surface.

  17. Antioxidant and antimicrobial activities of squid ink powder

    OpenAIRE

    Fatimah Zaharah, M.Y.; Rabeta, M.S.

    2017-01-01

    Economic development in Malaysia has led to increasing quantity and complexity of generated waste or by-product. The main objective of this study is to investigate the antioxidant and antimicrobial activities of squid ink powder. The squid ink was collected from fresh squid and dried using freeze dryer before it was ground into powder. The yield of squid ink was 22.82% after freeze-drying which was 69.37g in amount. Proximate composition analysis as well as two total antioxidant activity assa...

  18. Roller compaction: Effect of relative humidity of lactose powder.

    Science.gov (United States)

    Omar, Chalak S; Dhenge, Ranjit M; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

    2016-09-01

    The effect of storage at different relative humidity conditions, for various types of lactose, on roller compaction behaviour was investigated. Three types of lactose were used in this study: anhydrous lactose (SuperTab21AN), spray dried lactose (SuperTab11SD) and α-lactose monohydrate 200M. These powders differ in their amorphous contents, due to different manufacturing processes. The powders were stored in a climatic chamber at different relative humidity values ranging from 10% to 80% RH. It was found that the roller compaction behaviour and ribbon properties were different for powders conditioned to different relative humidities. The amount of fines produced, which is undesirable in roller compaction, was found to be different at different relative humidity. The minimum amount of fines produced was found to be for powders conditioned at 20-40% RH. The maximum amount of fines was produced for powders conditioned at 80% RH. This was attributed to the decrease in powder flowability, as indicated by the flow function coefficient ffc and the angle of repose. Particle Image Velocimetry (PIV) was also applied to determine the velocity of primary particles during ribbon production, and it was found that the velocity of the powder during the roller compaction decreased with powders stored at high RH. This resulted in less powder being present in the compaction zone at the edges of the rollers, which resulted in ribbons with a smaller overall width. The relative humidity for the storage of powders has shown to have minimal effect on the ribbon tensile strength at low RH conditions (10-20%). The lowest tensile strength of ribbons produced from lactose 200M and SD was for powders conditioned at 80% RH, whereas, ribbons produced from lactose 21AN at the same condition of 80% RH showed the highest tensile strength. The storage RH range 20-40% was found to be an optimum condition for roll compacting three lactose powders, as it resulted in a minimum amount of fines in the

  19. Nanocarbon materials obtained of coniferous trees in the composition of black powder

    Directory of Open Access Journals (Sweden)

    Zulkhair Mansurov

    2012-03-01

    Full Text Available Obtained black powders from coniferous wood. The carbon content of up to 90% can be used in warfare, pyrotechnics and industries. In the Republic of Kazakhstan does not produce gunpowder. In the energy-intensive materials laboratory, developed industrial black powders (ordinary, composed of components produced in the republic of Kazakhstan. Sulfur, activated carbon, based on apricot seeds and rice husks, softwood sawdust, which have lower costs than their foreign counterparts.

  20. Structural studies of carbon nanotubes by powder x-ray diffraction at SPring-8 and KEK PF

    CERN Document Server

    Maniwa, Y; Fujiwara, A

    2003-01-01

    Powder X-ray diffraction (XRD) studies on carbon nanotubes (CNTs) using synchrotron radiation are reported. In spite of the observed broad XRD peak profiles of two-dimensional triangular (hexagonal) lattice of single-wall carbon nanotubes (SWNTs), it was shown that useful structural information, such as the tube diameter and its distribution, can be deduced from detailed analysis of the characteristic XRD patterns. In particular, powder-XRD measurements were performed to study the phase transition of encapsulated materials inside SWNTs. In the C sub 7 sub 0 -one dimensional (1D) crystals formed inside SWNTs, importance of one-dimensionality in the C sub 7 sub 0 -molecular dynamics was suggested. It was also shown that water inside SWNTs undergoes a phase transition from liquid to an ice-nanotube structure below -38degC. Conversion process from SWNT to double-wall carbon nanotube (DWNT) was also studied by XRD.

  1. Evaluation of alloying effect on the formation of Ni-Fe nanosized powders by pulsed wire discharge

    International Nuclear Information System (INIS)

    Park, Gyu-Hyeon; Lee, Gwang-Yeob; Kim, Hyeon-Ah; Lee, A-Young; Oh, Hye-Ryeong; Kim, Song-Yi; Kim, Do-Hyang; Lee, Min-Ha

    2016-01-01

    Highlights: • Synthesizing Ni-Fe alloy nano-powder employing Ni-plating layer of Fe wire by PWD process. • The mean particle size is decreased with increasing the charging voltage affecting to the super heating factor (K). • The mean particle size of PWD Ni-Fe nanosized powder is accordance with applied voltage. • Uniformity of mean particel size can be controlled by adjusting charging voltage and super heating factor (K). - Abstract: This study investigates the effects of varying the explosion time and charging voltage of pulsed wire discharge (PWD) on the mean particle size, dispersibility and alloying reliability of powders produced from pure Ni and Ni-plated Fe wires. It was found that with increasing charging voltage, the mean particle size of Ni powders is reduced from 40.11 ± 0.23 to 25.63 ± 0.07 nm, which is attributed to a change in the extent of super heating with particle size. Nanosized powders of Ni-Fe alloy with a mean particle size between 25.91 ± 0.24 and 26.30 ± 0.26 nm were also successfully fabricated and found to consist of particles with a γ-(Ni/Fe) core and FeO shell. The reliability for the optimization of processing parameters to control particle sizes is also evaluated.

  2. Evaluation of alloying effect on the formation of Ni-Fe nanosized powders by pulsed wire discharge

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gyu-Hyeon [Advanced Functional Materials R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Lee, Gwang-Yeob [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Deparment of Advanced Materials Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Hyeon-Ah [Advanced Functional Materials R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Deparment of Advanced Materials Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, A-Young; Oh, Hye-Ryeong; Kim, Song-Yi [Advanced Functional Materials R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Kim, Do-Hyang [Deparment of Advanced Materials Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Min-Ha, E-mail: mhlee1@kitech.re.kr [Advanced Functional Materials R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of)

    2016-10-15

    Highlights: • Synthesizing Ni-Fe alloy nano-powder employing Ni-plating layer of Fe wire by PWD process. • The mean particle size is decreased with increasing the charging voltage affecting to the super heating factor (K). • The mean particle size of PWD Ni-Fe nanosized powder is accordance with applied voltage. • Uniformity of mean particel size can be controlled by adjusting charging voltage and super heating factor (K). - Abstract: This study investigates the effects of varying the explosion time and charging voltage of pulsed wire discharge (PWD) on the mean particle size, dispersibility and alloying reliability of powders produced from pure Ni and Ni-plated Fe wires. It was found that with increasing charging voltage, the mean particle size of Ni powders is reduced from 40.11 ± 0.23 to 25.63 ± 0.07 nm, which is attributed to a change in the extent of super heating with particle size. Nanosized powders of Ni-Fe alloy with a mean particle size between 25.91 ± 0.24 and 26.30 ± 0.26 nm were also successfully fabricated and found to consist of particles with a γ-(Ni/Fe) core and FeO shell. The reliability for the optimization of processing parameters to control particle sizes is also evaluated.

  3. Research on Durability of Recycled Ceramic Powder Concrete

    Science.gov (United States)

    Chen, M. C.; Fang, W.; Xu, K. C.; Xie, L.

    2017-06-01

    Ceramic was ground into powder with 325 mesh and used to prepare for concrete. Basic mechanical properties, carbonation and chloride ion penetration of the concrete tests were conducted. In addition, 6-hour electric fluxes of recycled ceramic powder concrete were measured under loading. The results showed that the age strength of ceramics powder concrete is higher than that of the ordinary concrete and the fly ash concrete. The ceramic powder used as admixture would reduce the strength of concrete under no consideration of its impact factor; under consideration of the impact factor for ceramic powder as admixture, the carbonation resistance of ceramic powder concrete was significantly improved, and the 28 day carbonation depth of the ceramic powder concrete was only 31.5% of ordinary concrete. The anti-chloride-permeability of recycled ceramic powder concrete was excellent.

  4. A coagulation-powdered activated carbon-ultrafiltration - Multiple barrier approach for removing toxins from two Australian cyanobacterial blooms

    International Nuclear Information System (INIS)

    Dixon, Mike B.; Richard, Yann; Ho, Lionel; Chow, Christopher W.K.; O'Neill, Brian K.; Newcombe, Gayle

    2011-01-01

    Cyanobacteria are a major problem for the world wide water industry as they can produce metabolites toxic to humans in addition to taste and odour compounds that make drinking water aesthetically displeasing. Removal of cyanobacterial toxins from drinking water is important to avoid serious illness in consumers. This objective can be confidently achieved through the application of the multiple barrier approach to drinking water quality and safety. In this study the use of a multiple barrier approach incorporating coagulation, powdered activated carbon (PAC) and ultrafiltration (UF) was investigated for the removal of intracellular and extracellular cyanobacterial toxins from two naturally occurring blooms in South Australia. Also investigated was the impact of these treatments on the UF flux. In this multibarrier approach, coagulation was used to remove the cells and thus the intracellular toxin while PAC was used for extracellular toxin adsorption and finally the UF was used for floc, PAC and cell removal. Cyanobacterial cells were completely removed using the UF membrane alone and when used in conjunction with coagulation. Extracellular toxins were removed to varying degrees by PAC addition. UF flux deteriorated dramatically during a trial with a very high cell concentration; however, the flux was improved by coagulation and PAC addition.

  5. Fly ash: An alternative to powdered activated carbon for the removal of eosin dye from aqueous solutions

    Directory of Open Access Journals (Sweden)

    V.O. Njoku

    2013-05-01

    Full Text Available This paper reports the use of powdered activated carbon (PAC and raw coal fly ash (RFA in the removal of eosin dye from aqueous solution in batch processes. Operational parameters such as contact time, initial dye concentration, pH and temperature were investigated. Adsorption equilibrium was established in 120 min for the two adsorbents. Langmuir and Freundlich isotherms were used to fit the adsorption data. Langmuir model gave the best fit in both cases. The adsorption capacities of PAC and RFA were found to be 62.28 mg/g and 43.48 mg/g, respectively. The highest percentage of eosin dye removal for both PAC (98% and RFA (90% was observed at pH 2. Pseudo first-order and pseudo second-order kinetic models were used to fit the adsorption data. Pseudo second-order kinetic model gave the best description of the adsorption of eosin dye onto the two adsorbents. Thermodynamic parameters, ΔH0, ΔS0 and ΔG0 confirmed the physical nature, spontaneity and the endothermic nature of the adsorption process. A regeneration technique and a process calculation for evaluating the adsorbent dose required were carried out. This study has shown that RFA is a good alternative adsorbent in the removal of eosin dye from aqueous solution.

  6. Enhanced coagulation with powdered activated carbon or MIEX secondary treatment: a comparison of disinfection by-product formation and precursor removal.

    Science.gov (United States)

    Watson, Kalinda; Farré, Maria José; Knight, Nicole

    2015-01-01

    The removal of both organic and inorganic disinfection by-product (DBP) precursors prior to disinfection is important in mitigating DBP formation, with halide removal being particularly important in salinity-impacted water sources. A matrix of waters of variable alkalinity, halide concentration and dissolved organic carbon (DOC) concentration were treated with enhanced coagulation (EC) followed by anion exchange (MIEX resin) or powdered activated carbon (PAC) and the subsequent disinfection by-product formation potentials (DBP-FPs) assessed and compared to DBP-FPs for untreated samples. Halide and DOC removal were also monitored for both treatment processes. Bromide and iodide adsorption by MIEX treatment ranged from 0 to 53% and 4-78%, respectively. As expected, EC and PAC treatments did not remove halides. DOC removal by EC/PAC was 70 ± 10%, while EC/MIEX enabled a DOC removal of 66 ± 12%. Despite the halide removals achieved by MIEX, increases in brominated disinfection by-product (Br-DBP) formation were observed relative to untreated samples, when favourable Br:DOC ratios were created by the treatment. However, the increases in formation were less than what was observed for the EC/PAC treated waters, which caused large increases in Br-DBP formation when high Br-DBP-forming water quality conditions occurred. The formation potential of fully chlorinated DBPs decreased after treatment in all cases.

  7. Carbon film electrodes for super capacitor applications

    Science.gov (United States)

    Tan, Ming X.

    1999-01-01

    A microporous carbon film for use as electrodes in energy strorage devices is disclosed, which is made by the process comprising the steps of: (1) heating a polymer film material consisting essentially of a copolymer of polyvinylidene chloride and polyvinyl chloride in an inert atmosphere to form a carbon film; and (2) activating said carbon film to form said microporous carbon film having a density between about 0.7 g/cm.sup.2 and 1 g/cm.sup.2 and a gravimetric capacitance of about between 120 F/g and 315 F/g.

  8. Vapor mercury uptake with sulphur impregnated active carbons derived using sulphur dioxide

    International Nuclear Information System (INIS)

    Tong, S.; Methta, H.; Ahmed, I.; Morris, E.; Fuentes de Maria, L.; Jia, C.Q.

    2008-01-01

    Active carbon adsorption is the primary technology used for removal of vapour mercury from flue gases in coal-fired power plants, municipal solid waste combustors, and other sources. It can be carried out using two different processes, notably injection of powder active carbon into flue gas streams upstream of the particulate collection devices, and filtration with a granular active carbon fixed bed downstream of the flue gas desulphurization units and/or particulate collectors. This paper presented an investigation of vapour mercury uptake performance of laboratory-made sulphur impregnated active carbons (SIACs) using a fixed bed reactor in a temperature range of 25 to 200 degrees Celsius. The materials and methods as well as the properties of activated carbons studied were presented. The experimental set-up was also described. The paper discussed the effects of initial concentration, the flow rate, the loading amount of SIACs, temperature, and the sulphur impregnation on the mercury uptake performance. The study showed that SIACs produced with sulphur dioxide exhibited a more complicated behaviour when temperature was varied, implying a mixed adsorption mechanism. 10 refs., 3 tabs., 8 figs

  9. Superfine powdered activated carbon (S-PAC) coatings on microfiltration membranes: Effects of milling time on contaminant removal and flux.

    Science.gov (United States)

    Amaral, Pauline; Partlan, Erin; Li, Mengfei; Lapolli, Flavio; Mefford, O Thompson; Karanfil, Tanju; Ladner, David A

    2016-09-01

    In microfiltration processes for drinking water treatment, one method of removing trace contaminants is to add powdered activated carbon (PAC). Recently, a version of PAC called superfine PAC (S-PAC) has been under development. S-PAC has a smaller particle size and thus faster adsorption kinetics than conventionally sized PAC. Membrane coating performance of various S-PAC samples was evaluated by measuring adsorption of atrazine, a model micropollutant. S-PACs were created in-house from PACs of three different materials: coal, wood, and coconut shell. Milling time was varied to produce S-PACs pulverized with different amounts of energy. These had different particles sizes, but other properties (e.g. oxygen content), also differed. In pure water the coal based S-PACs showed superior atrazine adsorption; all milled carbons had over 90% removal while the PAC had only 45% removal. With addition of calcium and/or NOM, removal rates decreased, but milled carbons still removed more atrazine than PAC. Oxygen content and specific external surface area (both of which increased with longer milling times) were the most significant predictors of atrazine removal. S-PAC coatings resulted in loss of filtration flux compared to an uncoated membrane and smaller particles caused more flux decline than larger particles; however, the data suggest that NOM fouling is still more of a concern than S-PAC fouling. The addition of calcium improved the flux, especially for the longer-milled carbons. Overall the data show that when milling S-PAC with different levels of energy there is a tradeoff: smaller particles adsorb contaminants better, but cause greater flux decline. Fortunately, an acceptable balance may be possible; for example, in these experiments the coal-based S-PAC after 30 min of milling achieved a fairly high atrazine removal (overall 80%) with a fairly low flux reduction (under 30%) even in the presence of NOM. This suggests that relatively short duration (low energy

  10. Enhanced adsorption of perfluorooctane sulfonate and perfluorooctanoate by bamboo-derived granular activated carbon.

    Science.gov (United States)

    Deng, Shubo; Nie, Yao; Du, Ziwen; Huang, Qian; Meng, Pingping; Wang, Bin; Huang, Jun; Yu, Gang

    2015-01-23

    A bamboo-derived granular activated carbon with large pores was successfully prepared by KOH activation, and used to remove perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from aqueous solution. The granular activated carbon prepared at the KOH/C mass ratio of 4 and activation temperature of 900°C had fast and high adsorption for PFOS and PFOA. Their adsorption equilibrium was achieved within 24h, which was attributed to their fast diffusion in the micron-sized pores of activated carbon. This granular activated carbon exhibited the maximum adsorbed amount of 2.32mmol/g for PFOS and 1.15mmol/g for PFOA at pH 5.0, much higher than other granular and powdered activated carbons reported. The activated carbon prepared under the severe activation condition contained many enlarged pores, favorable for the adsorption of PFOS and PFOA. In addition, the spent activated carbon was hardly regenerated in NaOH/NaCl solution, while the regeneration efficiency was significantly enhanced in hot water and methanol/ethanol solution, indicating that hydrophobic interaction was mainly responsible for the adsorption. The regeneration percent was up to 98% using 50% ethanol solution at 45°C. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. High-performance supercapacitors using a nanoporous current collector made from super-aligned carbon nanotubes

    Science.gov (United States)

    Zhou, Ruifeng; Meng, Chuizhou; Zhu, Feng; Li, Qunqing; Liu, Changhong; Fan, Shoushan; Jiang, Kaili

    2010-08-01

    Nanoporous current collectors for supercapacitors have been fabricated by cross-stacking super-aligned carbon nanotube (SACNT) films as a replacement for heavy conventional metallic current collectors. The CNT-film current collectors have good conductivity, extremely low density (27 µg cm - 2), high specific surface area, excellent flexibility and good electrochemical stability. Nanosized active materials such as NiO, Co3O4 or Mn2O3 nanoparticles can be directly synthesized on the SACNT films by a straightforward one-step, in situ decomposition strategy that is both efficient and environmentally friendly. These composite films can be integrated into a pseudo-capacitor that does not use metallic current collectors, but nevertheless shows very good performance, including high specific capacitance (~500 F g - 1, including the current collector mass), reliable electrochemical stability (<4.5% degradation in 2500 cycles) and a very high rate capability (245 F g - 1 at 155 A g - 1).

  12. High-performance supercapacitors using a nanoporous current collector made from super-aligned carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Ruifeng; Meng Chuizhou; Zhu Feng; Li Qunqing; Liu Changhong; Fan Shoushan; Jiang Kaili, E-mail: JiangKL@tsinghua.edu.cn [Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084 (China)

    2010-08-27

    Nanoporous current collectors for supercapacitors have been fabricated by cross-stacking super-aligned carbon nanotube (SACNT) films as a replacement for heavy conventional metallic current collectors. The CNT-film current collectors have good conductivity, extremely low density (27 {mu}g cm{sup -2}), high specific surface area, excellent flexibility and good electrochemical stability. Nanosized active materials such as NiO, Co{sub 3}O{sub 4} or Mn{sub 2}O{sub 3} nanoparticles can be directly synthesized on the SACNT films by a straightforward one-step, in situ decomposition strategy that is both efficient and environmentally friendly. These composite films can be integrated into a pseudo-capacitor that does not use metallic current collectors, but nevertheless shows very good performance, including high specific capacitance ({approx}500 F g{sup -1}, including the current collector mass), reliable electrochemical stability (<4.5% degradation in 2500 cycles) and a very high rate capability (245 F g{sup -1} at 155 A g{sup -1}).

  13. A comparative study of coagulation, granular- and powdered-activated carbon for the removal of perfluorooctane sulfonate and perfluorooctanoate in drinking water treatment.

    Science.gov (United States)

    Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Suja, Fatihah

    2015-01-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent organic pollutants in the environment and their occurrence causes toxicological effects on humans. We examined different conventional coagulant treatments such as alum, ferric chloride and polyaluminium chloride in removing these compounds. These were then compared with a natural coagulant (Moringa oleifera). We also investigated the powdered-activated carbon (PAC) and granular-activated carbon (GAC) for removing these compounds. At an initial dose of 5 mg/L, polyaluminium chloride led to a higher reduction of PFOS/PFOA compared with alum which in turn was higher than ferric. The removal efficiency increased with the increase in coagulant dose and decrease in pH. M. oleifera was very effective in reducing PFOS and PFOA than conventional coagulants, with a reduction efficiencies of 65% and 72%, respectively, at a dose of 30 mg/L. Both PAC and GAC were very effective in reducing these compounds than coagulations. PAC led to a higher reduction in PFOS and PFOA than GAC due to its greater surface area and shorter internal diffusion distances. The addition of PAC (10 min contact time) with coagulation (at 5 mg/L dosage) significantly increased the removal efficiency, and the maximum removal efficiency was for M. oleifera with 98% and 94% for PFOS and PFOA, respectively. The reduction efficiency of PFOS/PFOA was reduced with the increase in dissolved organic concentration due to the adsorption competition between organic molecules and PFOS/PFOA.

  14. Improving Settling Dynamics of Activated Sludge by Adding Fine Talc Powder

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Larsen, Torben; Clauss, F.

    1996-01-01

    The effect of adding varying mixtures of talc and chlorite powder to activated sludge in order to improve the settling characteristic has been studied. The powder is found to improve the settling velocity of the sludge, strictly by increasing the average density of the sludge floc aggregate. The ....... The settling velocity was measured with a recirculated settling column under different concentrations and turbulence levels. Numerical simulation of a secondary settling tank indicates that adding fine powder will improve the overall performance considerably.......The effect of adding varying mixtures of talc and chlorite powder to activated sludge in order to improve the settling characteristic has been studied. The powder is found to improve the settling velocity of the sludge, strictly by increasing the average density of the sludge floc aggregate...

  15. Two-dimensional distribution of carbon nanotubes in copper flake powders

    Energy Technology Data Exchange (ETDEWEB)

    Tan Zhanqiu; Li Zhiqiang; Fan Genlian; Li Wenhuan; Liu Qinglei; Zhang Wang; Zhang Di, E-mail: lizhq@sjtu.edu.cn, E-mail: zhangdi@sjtu.edu.cn [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2011-06-03

    We report an approach of flake powder metallurgy to the uniform, two-dimensional (2D) distribution of carbon nanotubes (CNTs) in Cu flake powders. It consists of the preparation of Cu flakes by ball milling in an imidazoline derivative (IMD) aqueous solution, surface modification of Cu flakes with polyvinyl alcohol (PVA) hydrosol and adsorption of CNTs from a CNT aqueous suspension. During ball milling, a hydrophobic monolayer of IMD is adsorbed on the surface of the Cu flakes, on top of which a hydrophilic PVA film is adsorbed subsequently. This PVA film could further interact with the carboxyl-group functionalized CNTs and act to lock the CNTs onto the surfaces of the Cu flakes. The CNT volume fraction is controlled easily by adjusting the concentration/volume of CNT aqueous suspension and Cu flake thickness. The as-prepared CNT/Cu composite flakes will serve as suitable building blocks for the self-assembly of CNT/Cu laminated composites that enable the full potential of 2D distributed CNTs to achieve high thermal conductivity.

  16. Two-dimensional distribution of carbon nanotubes in copper flake powders

    International Nuclear Information System (INIS)

    Tan Zhanqiu; Li Zhiqiang; Fan Genlian; Li Wenhuan; Liu Qinglei; Zhang Wang; Zhang Di

    2011-01-01

    We report an approach of flake powder metallurgy to the uniform, two-dimensional (2D) distribution of carbon nanotubes (CNTs) in Cu flake powders. It consists of the preparation of Cu flakes by ball milling in an imidazoline derivative (IMD) aqueous solution, surface modification of Cu flakes with polyvinyl alcohol (PVA) hydrosol and adsorption of CNTs from a CNT aqueous suspension. During ball milling, a hydrophobic monolayer of IMD is adsorbed on the surface of the Cu flakes, on top of which a hydrophilic PVA film is adsorbed subsequently. This PVA film could further interact with the carboxyl-group functionalized CNTs and act to lock the CNTs onto the surfaces of the Cu flakes. The CNT volume fraction is controlled easily by adjusting the concentration/volume of CNT aqueous suspension and Cu flake thickness. The as-prepared CNT/Cu composite flakes will serve as suitable building blocks for the self-assembly of CNT/Cu laminated composites that enable the full potential of 2D distributed CNTs to achieve high thermal conductivity.

  17. Two-dimensional distribution of carbon nanotubes in copper flake powders.

    Science.gov (United States)

    Tan, Zhanqiu; Li, Zhiqiang; Fan, Genlian; Li, Wenhuan; Liu, Qinglei; Zhang, Wang; Zhang, Di

    2011-06-03

    We report an approach of flake powder metallurgy to the uniform, two-dimensional (2D) distribution of carbon nanotubes (CNTs) in Cu flake powders. It consists of the preparation of Cu flakes by ball milling in an imidazoline derivative (IMD) aqueous solution, surface modification of Cu flakes with polyvinyl alcohol (PVA) hydrosol and adsorption of CNTs from a CNT aqueous suspension. During ball milling, a hydrophobic monolayer of IMD is adsorbed on the surface of the Cu flakes, on top of which a hydrophilic PVA film is adsorbed subsequently. This PVA film could further interact with the carboxyl-group functionalized CNTs and act to lock the CNTs onto the surfaces of the Cu flakes. The CNT volume fraction is controlled easily by adjusting the concentration/volume of CNT aqueous suspension and Cu flake thickness. The as-prepared CNT/Cu composite flakes will serve as suitable building blocks for the self-assembly of CNT/Cu laminated composites that enable the full potential of 2D distributed CNTs to achieve high thermal conductivity.

  18. Remarkable improvement of the wear resistance of poly(vinylidene difluoride) by incorporating polyimide powder and carbon nanofibers

    Science.gov (United States)

    Min, Chunying; Liu, Dengdeng; Shen, Chen; Zhang, Qiaqia; Shen, Xiaojuan; Zhang, Kan

    2017-10-01

    Poly(vinylidene difluoride) (PVDF) composites reinforced via adding different fillers have attracted wide attention in the field of dielectric materials, but few have been reported in the tribological area. In this paper, the effect of polyimide (PI) powder and carbon nanofibers (CF) as reinforcement phases on the friction and wear performance of PVDF composites has been investigated. It was found that PI powder enhances the mechanical and tribological properties of PVDF and especially as the content of the PI powder reaches 5 wt%. In addition, CF and PI exhibited synergistic effect on the tribological properties of PVDF. With PVDF containing 5 wt% PI powder and 20 wt% CF, the friction and wear behavior of the PVDF composite showed the best performance. PVDF, PI powder and CF can form a consistent network structure, which prevents the polymer molecular chains from moving or deformation, decreasing the wear loss of PVDF composites.

  19. Antioxidant and antimicrobial activities of squid ink powder

    Directory of Open Access Journals (Sweden)

    Fatimah Zaharah, M.Y.

    2017-10-01

    Full Text Available Economic development in Malaysia has led to increasing quantity and complexity of generated waste or by-product. The main objective of this study is to investigate the antioxidant and antimicrobial activities of squid ink powder. The squid ink was collected from fresh squid and dried using freeze dryer before it was ground into powder. The yield of squid ink was 22.82% after freeze-drying which was 69.37g in amount. Proximate composition analysis as well as two total antioxidant activity assays named 2,2-diphenyl-1-picrylhydrazyl (DPPH assay and Ferric Reducing Antioxidant Power (FRAP assay, and antimicrobial analysis were done on the powdered squid ink. The proximate results of squid ink powder were 4.43 ± 0.29% moisture, 62.46 ± 0.62% protein, 3.96 ± 0.08% fat, and 9.29 ± 0.05% ash. Results of DPPH assay showed that water extraction of squid ink powder has the highest 94.87 ± 4.87%, followed by ethanol 67.57 ± 7.55%, and hexane extract 2.10 ± 1.18%. FRAP assay result presented the same trend with water extraction had the highest value of 929.67 ± 2.31 μmol Fe (II / g of sample extract, followed by ethanol extract 201.00 ± 26.29 μmol Fe (II per gram sample and hexane 79.67 ± 12.66 μmol Fe (II / g of sample extract. Both water and ethanol extract showed antimicrobial properties with inhibition range of 7 to 15 mm, respectively. Fresh squid ink had 1.254 × 103 colony forming unit per gram of sample of microbial content. Squid ink powder had protein as major compound and microbial content was below from standard value of fisheries products as stated in Food Act 1983 and Regulation 1985.

  20. Microstructure and Transparent Super-Hydrophobic Performance of Vacuum Cold-Sprayed Al2O3 and SiO2 Aerogel Composite Coating

    Science.gov (United States)

    Li, Jie; Zhang, Yu; Ma, Kai; Pan, Xi-De; Li, Cheng-Xin; Yang, Guan-Jun; Li, Chang-Jiu

    2018-02-01

    In this study, vacuum cold spraying was used as a simple and fast way to prepare transparent super-hydrophobic coatings. Submicrometer-sized Al2O3 powder modified by 1,1,2,2-tetrahydroperfluorodecyltriethoxysilane and mixed with hydrophobic SiO2 aerogel was employed for the coating deposition. The deposition mechanisms of pure Al2O3 powder and Al2O3-SiO2 mixed powder were examined, and the effects of powder structure on the hydrophobicity and light transmittance of the coatings were evaluated. The results showed that appropriate contents of SiO2 aerogel in the mixed powder could provide sufficient cushioning to the deposition of submicrometer Al2O3 powder during spraying. The prepared composite coating surface showed rough structures with a large number of submicrometer convex deposited particles, characterized by being super-hydrophobic. Also, the transmittance of the obtained coating was higher than 80% in the range of visible light.

  1. Fabricating Super-hydrophobic Polydimethylsiloxane Surfaces by a Simple Filler-Dissolved Process

    Science.gov (United States)

    Lin, Yung-Tsan; Chou, Jung-Hua

    2010-12-01

    The self-cleaning effect of super-hydrophobic surfaces has attracted the attention of researchers. Typical ways of manufacturing super-hydrophobic surfaces include the use of either dedicated equipment or a complex chemical process. In this study, a simple innovative filler-dissolved method is developed using mainly powder salt and rinsing to form hydrophobic surfaces. This method can produce large super-hydrophobic surfaces with porous and micro rib surface structures. It can also be applied to curved surfaces, including flexible membranes. The contact angle of the manufactured artificial hydrophobic surface is about 160°. Furthermore, water droplets roll off the surface readily at a sliding angle of less than 5°, resembling the nonwetting lotus like effect.

  2. Feasibility study for application of the marine coral powder as a novel adsorbent for Volatile Organic Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Alireza Mashkoori

    2015-06-01

    Full Text Available The marine coral has a porous outer surface and it has served in the processes such as water treatment systems, removal of carbon dioxide and adsorption of arsenic. Based on the need for cheap and efficient adsorbents, in sampling, the aim of this study, comparison of the efficiency of marine coral powder and activated charcoal in adsorption of volatile organic hydrocarbons was considered. In this experimental research, a certain concentrations of 8 volatile organic hydrocarbons: (para-Xylene, Chloroform, Carbon tetrachloride, tert-Butanol, Pyridine, Acetone, Ethyl acetate and Diethyl ether was injected into dynamic atmospheric chamber in the NTP (Normal Temperature and Pressure conditions. Air sampling was performed with the tube containing marine coral powder as well as the tube of activated charcoal, based on the standard method of NIOSH (National Institute of Occupational Safety and Health and in the same laboratory conditions. Then samples were injected into the gas Chromatograph apparatus and analytical comparison has been done between the amount of adsorption of hydrocarbons by activated charcoal and coral powder-test and Mann-Whitney were done with SPSS V.20.Findings showed that there was a significant difference between the amount of adsorption of Para-Xylene, carbon tetrachloride, tert-Butanol, Pyridine, acetone and Ethyl acetate hydrocarbons by activated charcoal and coral powder (P<0.05(. The amount of hydrocarbons adsorption by activated charcoal was, more than coral powder significantly (P<0.001. Based on the present research, in sampling of used hydrocarbons, the marine coral powder was less efficient than the activated charcoal, and it is recommended that more works be designed about other techniques such as coating of the marine coral powder in order to the improvement of adsorption capacity for volatile organic hydrocarbons.

  3. Anti-carburizing Coating for Resin Sand Casting of Low Carbon Steel Based on Composite Silicate Powder Containing Zirconium

    Directory of Open Access Journals (Sweden)

    Zhan Chunyi

    2018-01-01

    Full Text Available This paper studied the structure and properties of anticarburizing coating based on composite silicate powder containing zirconium by X-ray diffraction analyzer, thermal expansion tester, digital microscope and other equipment. It is introduced that the application example of the coating in the resin-sand casting of ZG1Cr18Ni9Ti stainless steel impeller. The anti-carburizing effect of the coating on the surface layer of the cast is studied by using direct reading spectrometer and spectrum analyzer. The change of the micro-structure of the coating after casting and cooling is observed by scanning electron microscope. The analysis of anti-carburizing mechanism of the coating is presented. The results indicate that the coating possesses excellent suspension property, brush ability, permeability, levelling property and crackresistance. The coating exhibits high strength and low gas evolution. Most of the coating could be automatically stripped off flakily when the casting was shaken out. The casting possesses excellent surface finish and antimetal penetration effect. The carburizing layer thickness of the stainless steel impeller casting with respect to allowable upper limit of carbon content is about 1mm and maximum carburizing rate is 23.6%. The anticarburizing effect of casting surface is greatly improved than that of zircon powder coating whose maximum carburizing rate is 67.9% and the carburizing layer thickness with respect to allowable upper limit of carbon content is greater than 2mm. The composite silicate powder containing zirconium coating substantially reduces the zircon powder which is expensive and radioactive and mainly dependent on imports. The coating can be used instead of pure zircon powder coating to effectively prevent metal-penetration and carburizing of resin-sand-casting surface of low carbon steel, significantly improve the foundry production environment and reduce the production costs.

  4. Comparison of The Performance of Proton Exchange Membrane Fuel Cell (PEMFC Electrodes with Different Carbon Powder Content and Methods of Manufacture

    Directory of Open Access Journals (Sweden)

    Dedi Rohendi

    2016-11-01

    Full Text Available Carbon powder in the gas diffusion layer (GDL contained in the membrane electrode assembly (MEA has an important role in the flow of electrons and reactant gas. Meanwhile, the method of making the electrode is one of the many studies conducted to determine the most appropriate method to use. Comparative study of the performance of proton exchange membrane fuel cell (PEMFC electrodes with different carbon powder content (vulcan XC-72 in the GDL and methods of manufacture of the electrode between casting and spraying method has been carried out. The spraying method consists of one layer and three layer of catalyst layer (CL. The content of carbon powder in the GDL as much as 3 mg cm-2 has a better performance compared to 1.5 mg cm-2 with an increase of 177.78% current density at 0.6 V. Meanwhile, the manufacture of CL with three-layer spraying method has better performance compared with one-layer spraying and casting method.

  5. Some results of experimental investigation of super-deep penetration into the metal's targets

    International Nuclear Information System (INIS)

    Andilevko, S.K.; Roman, O.V.; Usherenko, S.M.; Shilkin, V.A.

    1994-01-01

    The phenomenon of Super-Deep Penetration (SDP) is briefly presented. Various experimental techniques, including that based on neutron-activated autoradiography (NAAR), for experimentally investigating this phenomenon are described. Results from a number of investigations in which the effect on SDP of initial target temperature, the dependence of the concentration on depth for different powder particles and the use of bimetallic targets, are reviewed. The complicated nature of the SDP process and the need for a wider range of experimental data if it is to be fully understood are discussed. (orig.)

  6. [Use of powder metallurgy for development of implants of Co-Cr-Mo alloy powder].

    Science.gov (United States)

    Dabrowski, J R

    2001-04-01

    This paper discusses the application of powder metallurgy for the development of porous implantation materials. Powders obtained from Co-Cr-Mo alloy with different carbon content by water spraying and grinding, have been investigated. Cold pressing and rotary re-pressing methods were used for compressing the powder. It was found that the sintered materials obtained from water spraying have the most advantageous properties.

  7. Microwave Effect for Glycosylation Promoted by Solid Super Acid in Supercritical Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Takahiko Maeda

    2009-12-01

    Full Text Available The effects of microwave irradiation (2.45 GHz, 200 W on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solution, but enhanced reaction yield when aliphatic acceptors are employed. Interestingly, the use of a phenolic acceptor under the same reaction conditions did not show these promoting effects due to microwave irradiation. In the case of aliphatic diol acceptors, the yield seemed to be dependent on the symmetrical properties of the acceptors. The results suggest that microwave irradiation do not affect the reactivity of the donor nor promoter independently. We conclude that the effect of acceptor structure on glycosylation yield is due to electric delocalization of hydroxyl group and dielectrically symmetric structure of whole molecule.

  8. Surface properties of activated carbon treated by cold plasma heating

    Energy Technology Data Exchange (ETDEWEB)

    Norikazu, Kurano [Shigematsu works Co. Ltd., 267 Yashita, Iwatsuki 3390046 (Japan); Yamada, Hiroshi [Shigematsu works Co. Ltd., 267 Yashita, Iwatsuki 3390046 (Japan); Yajima, Tatsuhiko [Faculty of Engineering, Saitama Institute of Technology, 1690 Fusoiji, Okabe 3690293 (Japan); Sugiyama, Kazuo [Faculty of Engineering, Saitama University, 255 Shimo-okubo, Sakura-Ku, Saitama 3388570 (Japan)]. E-mail: sugi@apc.saitama-u.ac.jp

    2007-03-12

    To modify the surface properties of activated carbon powders, we have applied the cold plasma treatment method. The cold plasma was used to be generated in the evacuated reactor vessel by 2.45 GHz microwave irradiation. In this paper, changes of surface properties such as distribution of acidic functional groups and roughness morphology were examined. By the cold plasma treatment, activated carbons with large specific surface area of ca. 2000 m{sup 2}/g or more could be prepared in a minute. The amount of every gaseous organic compound adsorbed on the unit gram of treated activated carbons was more increased that on the unit gram of untreated carbons. Especially, the adsorbed amount of carbon disulfide was remarkably increased even if it was compared by the amount per unit surface area. These results suggest that the surface property of the sample was modified by the plasma treatment. It became apparent by observing SEM photographs that dust and impure particles in macropores of activated carbons were far more reduced by the plasma treatment than by the conventional heating in an electric furnace under vacuum. In addition, a bubble-like surface morphology of the sample was observed by AEM measurement. The amount of acidic functional groups at the surface was determined by using the Boehm's titration method. Consequently, the increase of lactone groups and the decrease of carboxyl groups were also observed.

  9. Catalytic activity of tungsten carbide-carbon (WC@C) core-shell structured for ethanol electro-oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Singla, Gourav, E-mail: gsinghla@gmail.com; Singh, K., E-mail: kusingh@thapar.edu; Pandey, O.P., E-mail: oppandey@thapar.edu

    2017-01-15

    In this study, carbon coated WC (WC@C) was synthesized through solvothermal reactions in the presence of reducing agent magnesium (Mg) by employing tungsten oxide (WO{sub 3}) as a precursor, acetone (C{sub 3}H{sub 6}O) as a carbon source. The formation of WC@C nano particles is confirmed by X-ray diffraction and Transmission electron microscopy. The thermal stability of the synthesized powder examined in air shows its stability up to 550 °C. In this method, in-situ produced outer carbon layer increase the surface area of materials which is 52.6 m{sup 2} g{sup −1} with pore volume 0.213 cm{sup 3} g{sup −1}. The Electrocatalytic activity of ethanol oxidation on a synthesized sample with and without Pt nano particles have been investigated using cyclic voltammetry (CV). The CV results show the enhancement in oxidation stability of WC@C in acidic media as well as better CO-tolerance for ethanol oxidation after the deposition of Pt nanoparticles as compared to without Pt nano particles. - Highlights: • Tungsten carbide nano powder was synthesized using acetone as carbon source. • In-situ produced outer carbon layer increase the surface area of materials. • Mesoporous WC with surface areas 52.6 m{sup 2}/g obtained. • Pt modified WC powder showed higher electrochemical stability. • Better CO-tolerance for ethanol oxidation after the deposition of Pt nanoparticles.

  10. Microstructural and electrical changes in nickel manganite powder induced by mechanical activation

    International Nuclear Information System (INIS)

    Savic, S.M.; Mancic, L.; Vojisavljevic, K.; Stojanovic, G.; Brankovic, Z.; Aleksic, O.S.; Brankovic, G.

    2011-01-01

    Highlights: → The influence of mechanical activation on microstructure evolution in the nickel manganite powder was investigated as well as electrical properties of the sintered samples. → Structural refinement obtained by Topas-Academic software based on Rietveld analysis showed that the milling process remarkably changed the powder morphology and microstructure. → SEM studies of sintered samples also revealed the strong influence of milling time on ceramics density (increases with milling time). → The electrical properties of ceramic samples are clearly conditioned by terms of synthesis, in our case the time of mechanical activation. → The highest density and higher values of dielectric constant were achieved at the sample activated for 45 min. -- Abstract: Nickel manganite powder synthesized by calcination of a stoichiometric mixture of manganese and nickel oxide was additionally mechanically activated in a high energy planetary ball mill for 5-60 min in order to obtain a pure NiMn 2 O 4 phase. The as-prepared powders were uniaxially pressed into disc shape pellets and then sintered for 60 min at 1200 o C. Changes in the particle morphology induced by mechanical activation were monitored using scanning electron microscopy, while changes in powder structural characteristics were followed using X-ray powder diffraction. The ac impedance spectroscopy was performed on sintered nickel manganite samples at 25 o C, 50 o C and 80 o C. It was shown that mechanical activation intensifies transport processes causing a decrease in the average crystallites size, while longer activation times can lead to the formation of aggregates, defects and increase of lattice microstrains. The observed changes in microstructures were correlated with measured electrical properties in order to define optimal processing conditions.

  11. A CO2 laser based system for the production of nanoscaled powders

    International Nuclear Information System (INIS)

    Kurland, H.-D.; Schindler, K.; Staupendahl, G.; Oestreich, Ch.; Loogk, M.; Mueller, E.

    2002-01-01

    Nowadays the world-wide industrial competition is increasingly determined by the use of new materials which allow optimised and in part totally new qualities of products or the production of more compact components. Thereby the importance of ultrafine ceramic powders with grain sizes of only a few nanometers rises rapidly. These powders show some interesting physical and chemical features which result from the extremely small dimensions of their particles, for example very high specific surfaces, high surface energy or special behaviour in the phase transformation. Their thermodynamic and kinetic (short diffusion lengths) parameters are mirrored in high sintering activities and hence relatively low sintering temperatures as well as very special properties of the sintered materials, especially the possibility of super plasticity. Nanoscaled powders also have a broad potential for the production of thin layers for example in the electronics industry or as part of composite materials with components of lower thermal stability. At present different technologies for the manufacturing of nanoscaled powders are intensively used and developed. In this paper a technique for the production of ceramic nanopowders by evaporation of solid starting materials with CO 2 laser radiation is presented

  12. ELASTO-PLASTIC DEFORMATION OF COMPOSITE POWDERS WITH LAYERED CARBON AND CARBIDE-FORMING ELEMENT COATING

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevsky

    2012-01-01

    Full Text Available Coating structure formation under magnetron spraying of titanium and carbon cathodes and combined cathodes, namely cobalt (EP 131 – nickel, tungsten – carbon have been investigated under conditions of carbide separate synthesis within the temperature range of 650–1200 °C. Usage of cobalt and nickel particles as matrix material leads to their rapid thermal expansion under heating during sintering process in the dilatometer. Subsequent plastic deformation of sintered samples provides obtaining a composite powder material that is a composite with framing structure of cobalt, titanium and tungsten carbides in the coatings.

  13. Analysis of diffuse scattering in neutron powder diagrams. Application to glassy carbon

    International Nuclear Information System (INIS)

    Boysen, H.

    1985-01-01

    From the quantitative analysis of the diffuse scattered intensity in powder diagrams valuable information about the disorder in crystals may be obtained. According to the dimensionality of this disorder (0D, 1D, 2D or 3D corresponding to diffuse peaks, streaks, planes or volume in reciprocal space) a characteristic modulation of the background is observed, which is described by specific functions. These are derived by averaging the appropriate cross sections over all crystallite orientations in the powder and folding with the resolution function of the instrument. If proper account is taken of all proportionality factors different components of the background can be put on one relative scale. The results are applied to two samples of glassy carbon differing in their degree of disorder. The neutron powder patterns contain contributions from 0D (00l peaks due to the stacking of graphitic layers), 1D (hkzeta streaks caused by the random orientation of these layers) and 3D (incoherent scattering, averaged thermal diffuse scattering, multiple scattering). From the fit to the observed data various parameters of the disorder like domain sizes, strains, interlayer distances, amount of incorporated hydrogen, pore sizes etc. are determined. It is shown that the omission of resolution corrections leads to false parameters. (orig.)

  14. Carbon particle induced foaming of molten sucrose for the preparation of carbon foams

    International Nuclear Information System (INIS)

    Narasimman, R.; Vijayan, Sujith; Prabhakaran, K.

    2014-01-01

    Graphical abstract: - Highlights: • An easy method for the preparation of carbon foam from sucrose is presented. • Wood derived activated carbon particles are used to stabilize the molten sucrose foam. • The carbon foams show relatively good mechanical strength. • The carbon foams show excellent CO 2 adsorption and oil absorption properties. • The process could be scaled up for the preparation of large foam bodies. - Abstract: Activated carbon powder was used as a foaming and foam setting agent for the preparation of carbon foams with a hierarchical pore structure from molten sucrose. The rheological measurements revealed the interruption of intermolecular hydrogen bonding in molten sucrose by the carbon particles. The carbon particles stabilized the bubbles in molten sucrose by adsorbing on the molten sucrose–gas interface. The carbon foams obtained at the activated carbon powder to sucrose weight ratios in the range of 0–0.25 had a compressive strength in the range of 1.35–0.31 MPa. The produced carbon foams adsorb 2.59–3.04 mmol/g of CO 2 at 760 mmHg at 273 K and absorb oil from oil–water mixtures and surfactant stabilized oil-in-water emulsions with very good selectivity and recyclability

  15. Super Dielectric Materials

    Directory of Open Access Journals (Sweden)

    Samuel Fromille

    2014-12-01

    Full Text Available Evidence is provided here that a class of materials with dielectric constants greater than 105 at low frequency (<10−2 Hz, herein called super dielectric materials (SDM, can be generated readily from common, inexpensive materials. Specifically it is demonstrated that high surface area alumina powders, loaded to the incipient wetness point with a solution of boric acid dissolved in water, have dielectric constants, near 0 Hz, greater than 4 × 108 in all cases, a remarkable increase over the best dielectric constants previously measured for energy storage capabilities, ca. 1 × 104. It is postulated that any porous, electrically insulating material (e.g., high surface area powders of silica, titania, etc., filled with a liquid containing a high concentration of ionic species will potentially be an SDM. Capacitors created with the first generated SDM dielectrics (alumina with boric acid solution, herein called New Paradigm Super (NPS capacitors display typical electrostatic capacitive behavior, such as increasing capacitance with decreasing thickness, and can be cycled, but are limited to a maximum effective operating voltage of about 0.8 V. A simple theory is presented: Water containing relatively high concentrations of dissolved ions saturates all, or virtually all, the pores (average diameter 500 Å of the alumina. In an applied field the positive ionic species migrate to the cathode end, and the negative ions to the anode end of each drop. This creates giant dipoles with high charge, hence leading to high dielectric constant behavior. At about 0.8 V, water begins to break down, creating enough ionic species to “short” the individual water droplets. Potentially NPS capacitor stacks can surpass “supercapacitors” in volumetric energy density.

  16. Activated carbon/ZnO composites prepared using hydrochars as intermediate and their electrochemical performance in supercapacitor

    International Nuclear Information System (INIS)

    Li, Yueming; Liu, Xi

    2014-01-01

    We report a new methodology to prepare activated carbon and activated carbons/ZnO composites from walnut shell-derived hydrothermal carbons (hydrochars), which were prepared under hydrothermal condition in presence of ZnCl 2 . For this method, activated carbon/ZnO composites were prepared via heat treatment of hydrochars under inert environment and activated carbons were prepared by removing the ZnO in activated carbon/ZnO composites. The chemical structure of walnut shell, hydrochars, activated carbon/ZnO and activated carbon was investigated by Fourier transform infrared spectroscopy, Raman, X-ray powder diffraction, thermogravimetric analysis and N 2 adsorption/desorption measurements. It is found ZnCl 2 plays multiple roles, i.e., helping to remove the oxygen-containing groups during hydrothermal stage, improving the surface area of activated carbon and acting as the precursor of ZnO in heat-treatment stage. The specific surface areas up to 818.9 and 1072.7 m 2  g −1 have been achieved for activated carbon/ZnO composites and activated carbon, respectively. The activated carbon/ZnO as electrode materials for supercapacitors showed that specific capacitance of up to 117.4 F g −1 at a current density of 0.5 A g −1 in KOH aqueous solution can be achieved and keeps stable in 1000 cycles. - Highlights: • Hydrochars as intermediate to prepare activated carbon/ZnO composites. • Activated carbon/ZnO showed excellent electrochemical performance in supercapacitors. • Activated carbon with large surface area can be obtained by removing ZnO

  17. Microstructural and electrical changes in nickel manganite powder induced by mechanical activation

    Energy Technology Data Exchange (ETDEWEB)

    Savic, S.M., E-mail: slavicas@cms.bg.ac.rs [Institute for Multidisciplinary Research-University of Belgrade, Kneza Viseslava 1a, 11030 Belgrade (Serbia); Mancic, L. [Institute of Technical Sciences SASA, Knez Mihailova 35/IV, 11000 Belgrade (Serbia); Vojisavljevic, K. [Institute for Multidisciplinary Research-University of Belgrade, Kneza Viseslava 1a, 11030 Belgrade (Serbia); Stojanovic, G. [Faculty of Technical Sciences University of Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad (Serbia); Brankovic, Z.; Aleksic, O.S.; Brankovic, G. [Institute for Multidisciplinary Research-University of Belgrade, Kneza Viseslava 1a, 11030 Belgrade (Serbia)

    2011-07-15

    Highlights: {yields} The influence of mechanical activation on microstructure evolution in the nickel manganite powder was investigated as well as electrical properties of the sintered samples. {yields} Structural refinement obtained by Topas-Academic software based on Rietveld analysis showed that the milling process remarkably changed the powder morphology and microstructure. {yields} SEM studies of sintered samples also revealed the strong influence of milling time on ceramics density (increases with milling time). {yields} The electrical properties of ceramic samples are clearly conditioned by terms of synthesis, in our case the time of mechanical activation. {yields} The highest density and higher values of dielectric constant were achieved at the sample activated for 45 min. -- Abstract: Nickel manganite powder synthesized by calcination of a stoichiometric mixture of manganese and nickel oxide was additionally mechanically activated in a high energy planetary ball mill for 5-60 min in order to obtain a pure NiMn{sub 2}O{sub 4} phase. The as-prepared powders were uniaxially pressed into disc shape pellets and then sintered for 60 min at 1200 {sup o}C. Changes in the particle morphology induced by mechanical activation were monitored using scanning electron microscopy, while changes in powder structural characteristics were followed using X-ray powder diffraction. The ac impedance spectroscopy was performed on sintered nickel manganite samples at 25 {sup o}C, 50 {sup o}C and 80 {sup o}C. It was shown that mechanical activation intensifies transport processes causing a decrease in the average crystallites size, while longer activation times can lead to the formation of aggregates, defects and increase of lattice microstrains. The observed changes in microstructures were correlated with measured electrical properties in order to define optimal processing conditions.

  18. Stretchable and bendable carbon nanotube on PDMS super-lyophobic sheet for liquid metal manipulation

    International Nuclear Information System (INIS)

    Kim, Daeyoung; Jung, Daewoong; Yoo, Jun Hyeon; Lee, Gil S; Lee, Jeong-Bong; Lee, Yunho; Choi, Wonjae; Yoo, Koangki

    2014-01-01

    We report a vertically-aligned carbon nanotube (CNT) forest on polydimethylsiloxane (PDMS) sheet as a novel widely stretchable and bendable anti-wetting super-lyophobic surface for naturally oxidized gallium-based liquid metals. The vertically-aligned CNT has inherent chemical inertness and a hierarchical texture combining micro/nanoscale roughness; these two characters render the developed sheet as a super-lyophobic substrate against gallium-based liquid metals. The vertically-aligned CNT forest was first grown on Si substrate and then transferred onto a PDMS sheet by imprinting. It was found that the transferred CNT on the PDMS sheet maintained its vertically-aligned nature as well as hierarchical micro/nano surface morphology. It was found that the static contact angles of the gallium-based liquid metal droplet on the CNT on Si and on the CNT on PDMS were both greater than 155° and the contact angle hysteresis on the CNT on Si was 4° and that on the transferred CNT on PDMS was 19°. These measurement results showed that the surface retains a super-lyophobic property before and after the CNT transfer onto PDMS. We tested the CNT on PDMS sheet for its mechanical flexibility using stretching (50% and 100%) and bending (curvature of 0.1 and 0.4 mm −1 ). We carried out a bouncing test and a rolling test on the stretched/bent CNT on the PDMS sheet and the results confirmed that the flexible sheet maintains anti-wetting characteristics under bending or stretching conditions. (paper)

  19. Separation of Th from aqueous solutions using activated carbon

    International Nuclear Information System (INIS)

    Kutahyali, C.; Eral, M.

    2005-01-01

    Since the last century, thorium has been extensively used in a variety of applications. These applications produce various gaseous, liquid and solid wastes containing isotopes of thorium. Liquid wastes are freed into the surface or the underground waters of mines. Solid and liquid wastes are also produced during nuclear fuel production. Direct toxicity of thorium is low due to its stability at ambient temperatures; however thorium fine powder is self-ignitable to thorium oxide. When thorium nitrate enters living organisms it is mainly localized in liver, spleen and marrow and it precipitates in a hydroxide form. Investigations concerning the removal or minimization of the thorium concentration in the waste waters are of considerable importance environmental point of view. Adsorption is an important technique in separation and purification processes. Among many types of adsorbent materials, activated carbons are the most widely used, because of their large adsorptive capacity and low cost. Activated carbons are unique adsorbents because of their extended surface area, microporous structure, high adsorption capacity and high degree of surface reactivity. Separation and purification processes based on adsorption technique are also important in nuclear industry where activated carbon is often used for the separation of metal ions from solutions, due to its selective adsorption, high radiation stability and high purity. The activated carbons used in this study were prepared by the chemical activation of acrylic fiber. The chemical composition of acrylic fiber is a copolymer of acrylonitrile-vinyl acetate is called also poliacrylonitryl fiber. The effects of carbonization conditions resulting activated carbon were examined. Precursor/activating agent (KOH and ZnCl 2 ) ratio and carbonization temperature were investigated for the preparation of adsorbent. Adsorption experiments were carried out by a batch technique. The adsorption of thorium was studied as a function of

  20. Engineering catalytic activity via ion beam bombardment of catalyst supports for vertically aligned carbon nanotube growth

    Science.gov (United States)

    Islam, A. E.; Nikolaev, P.; Amama, P. B.; Zakharov, D.; Sargent, G.; Saber, S.; Huffman, D.; Erford, M.; Semiatin, S. L.; Stach, E. A.; Maruyama, B.

    2015-09-01

    Carbon nanotube growth depends on the catalytic activity of metal nanoparticles on alumina or silica supports. The control on catalytic activity is generally achieved by variations in water concentration, carbon feed, and sample placement on a few types of alumina or silica catalyst supports obtained via thin film deposition. We have recently expanded the choice of catalyst supports by engineering inactive substrates like c-cut sapphire via ion beam bombardment. The deterministic control on the structure and chemistry of catalyst supports obtained by tuning the degree of beam-induced damage have enabled better regulation of the activity of Fe catalysts only in the ion beam bombarded areas and hence enabled controllable super growth of carbon nanotubes. A wide range of surface characterization techniques were used to monitor the catalytically active surface engineered via ion beam bombardment. The proposed method offers a versatile way to control carbon nanotube growth in patterned areas and also enhances the current understanding of the growth process. With the right choice of water concentration, carbon feed and sample placement, engineered catalyst supports may extend the carbon nanotube growth yield to a level that is even higher than the ones reported here, and thus offers promising applications of carbon nanotubes in electronics, heat exchanger, and energy storage.

  1. CLOUDS IN SUPER-EARTH ATMOSPHERES: CHEMICAL EQUILIBRIUM CALCULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mbarek, Rostom; Kempton, Eliza M.-R., E-mail: mbarekro@grinnell.edu, E-mail: kemptone@grinnell.edu [Department of Physics, Grinnell College, Grinnell, IA 50112 (United States)

    2016-08-20

    Recent studies have unequivocally proven the existence of clouds in super-Earth atmospheres. Here we provide a theoretical context for the formation of super-Earth clouds by determining which condensates are likely to form under the assumption of chemical equilibrium. We study super-Earth atmospheres of diverse bulk composition, which are assumed to form by outgassing from a solid core of chondritic material, following Schaefer and Fegley. The super-Earth atmospheres that we study arise from planetary cores made up of individual types of chondritic meteorites. They range from highly reducing to oxidizing and have carbon to oxygen (C:O) ratios that are both sub-solar and super-solar, thereby spanning a range of atmospheric composition that is appropriate for low-mass exoplanets. Given the atomic makeup of these atmospheres, we minimize the global Gibbs free energy of formation for over 550 gases and condensates to obtain the molecular composition of the atmospheres over a temperature range of 350–3000 K. Clouds should form along the temperature–pressure boundaries where the condensed species appear in our calculation. We find that the composition of condensate clouds depends strongly on both the H:O and C:O ratios. For the super-Earth archetype GJ 1214b, KCl and ZnS are the primary cloud-forming condensates at solar composition, in agreement with previous work. However, for oxidizing atmospheres, K{sub 2}SO{sub 4} and ZnO condensates are favored instead, and for carbon-rich atmospheres with super-solar C:O ratios, graphite clouds appear. For even hotter planets, clouds form from a wide variety of rock-forming and metallic species.

  2. Synthesis of ITO Powder by Dry Process and Lifetime Characteristics of the ITO Target Fabricated with its Powder

    Science.gov (United States)

    Takahashi, Seiichiro; Itoh, Hironori; Komatsu, Ryuichi

    Lifetime of an indium tin oxide (ITO) target is an important characteristic in the production of liquid crystal displays (LCDs). Increasing the sintering density of the ITO target is assumed to lead to an increased lifetime. So far, it has been clarified that the carbon concentration in In2O3 powder, the raw material of ITO targets, influences remarkably the target lifetime. In this study, with the aim of reducing the concentration of carbon in In2O3 powder, the synthesis of In2O3 powder containing dissolved Sn by a dry process was performed.

  3. Electrical conductivity of molten carbonate and carbonate-chloride systems coexisting with aluminium oxide powder

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaeva, Elena V. [Institute of High Temperature Electrochemistry, Yekaterinburg (Russian Federation); Ural Federal Univ., Yekaterinburg (Russian Federation); Ural State Economic Univ., Yekaterinburg (Russian Federation); Bovet, Andrey L.; Zakiryanova, Irina D. [Institute of High Temperature Electrochemistry, Yekaterinburg (Russian Federation); Ural Federal Univ., Yekaterinburg (Russian Federation)

    2018-04-01

    The electrical properties of composite electrolytes (suspensions) composed of α-Al{sub 2}O{sub 3} powder and molten carbonate eutectic (Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} or molten carbonate-chloride mixture 0.72(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut}-0.28NaCl have been investigated by AC impedance method. This system shows a dependence of the electrical conductivity upon the temperature and the α-Al{sub 2}O{sub 3} content. The specific electrical conductivity of the α-Al{sub 2}O{sub 3}/(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} system can be adequately described by the Maxwell equation for two-phase heterogeneous materials. The regression equation for the dependence of the specific conductivity of the α-Al{sub 2}O{sub 3}/(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} composite on the aluminium oxide concentration and temperature was obtained.

  4. Super differential forms on super Riemann surfaces

    International Nuclear Information System (INIS)

    Konisi, Gaku; Takahasi, Wataru; Saito, Takesi.

    1994-01-01

    Line integral on the super Riemann surface is discussed. A 'super differential operator' which possesses both properties of differential and of differential operator is proposed. With this 'super differential operator' a new theory of differential form on the super Riemann surface is constructed. We call 'the new differentials on the super Riemann surface' 'the super differentials'. As the applications of our theory, the existency theorems of singular 'super differentials' such as 'super abelian differentials of the 3rd kind' and of a super projective connection are examined. (author)

  5. Effects of grinding on properties of Mg-PSZ ceramics prepared by the surface enrichment of zirconia powders

    International Nuclear Information System (INIS)

    Deb, S.; Das, S.R.

    1995-01-01

    Commercial grade zirconia powders of mean particle size of 3.21 microns were super-ground in wet condition in alcoholic medium in a Planetary Ball-Mill for 12-hours using a zirconia pot as well as balls, in order to avoid contaminations from the grinding media. Sedigraph analysis data show the mean particle sizes within the range of 0.4 to 0.2 micron. The super-ground zirconia powders were then treated with appropriate acid and alkali solutions in order to enrich the surfaces of zirconia powders. The chemical analysis reports depict the enrichment phenomena of the processed zirconia powders. Magnesium oxide of different mole percentages (3 to 9%) have been incorporated to the above super-ground and enriched zirconia powder and green specimens were prepared by pressing with a suitable pressure of 200 MPa to yield the green compaction density of 3.06 gm/cm 3 . The compacted green specimens were sintered without pressure at 1,480 C in air followed by normal cooling. X-ray diffraction patterns of the above sintered and cooled specimens have confirmed the formation of Mg-PSZ ceramics with 40% tetragonal phase. The sintered PSZ-products have shown very good surface properties but at the cost of transverse rupture strength. The effects of grinding were observed on the above Mg-PSZ ceramics which exhibit very little change in the tetragonal phase even after 30-minutes of grinding with a 60-mesh diamond wheel at a normal pressure of 4 kg/cm 2

  6. Activated carbon/ZnO composites prepared using hydrochars as intermediate and their electrochemical performance in supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yueming, E-mail: liyueming@ysu.edu.cn; Liu, Xi

    2014-11-14

    We report a new methodology to prepare activated carbon and activated carbons/ZnO composites from walnut shell-derived hydrothermal carbons (hydrochars), which were prepared under hydrothermal condition in presence of ZnCl{sub 2}. For this method, activated carbon/ZnO composites were prepared via heat treatment of hydrochars under inert environment and activated carbons were prepared by removing the ZnO in activated carbon/ZnO composites. The chemical structure of walnut shell, hydrochars, activated carbon/ZnO and activated carbon was investigated by Fourier transform infrared spectroscopy, Raman, X-ray powder diffraction, thermogravimetric analysis and N{sub 2} adsorption/desorption measurements. It is found ZnCl{sub 2} plays multiple roles, i.e., helping to remove the oxygen-containing groups during hydrothermal stage, improving the surface area of activated carbon and acting as the precursor of ZnO in heat-treatment stage. The specific surface areas up to 818.9 and 1072.7 m{sup 2} g{sup −1} have been achieved for activated carbon/ZnO composites and activated carbon, respectively. The activated carbon/ZnO as electrode materials for supercapacitors showed that specific capacitance of up to 117.4 F g{sup −1} at a current density of 0.5 A g{sup −1} in KOH aqueous solution can be achieved and keeps stable in 1000 cycles. - Highlights: • Hydrochars as intermediate to prepare activated carbon/ZnO composites. • Activated carbon/ZnO showed excellent electrochemical performance in supercapacitors. • Activated carbon with large surface area can be obtained by removing ZnO.

  7. Treatment of oil refinery effluent in a continuous reactor using Powdered Activated Carbon (PAC) in the activated sludge process; Tratamento de efluente de refinaria de petroleo em um reator continuo utilizando carvao ativado em po (CAP) no sistema de lodo ativado

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Lidia; Campos, Juacyara C.; Valle, Alexandre Ornellas do; Souza, Andre Lopes de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2008-07-01

    The process of oil refining generates effluent containing toxic substances as high molecular weight hydrocarbons which have toxicity or are recalcitrant to biological degradation. This study examined the introduction of powdered activated carbon (PAC) in the system of activated sludge used to treat of oil refinery effluent. The process was conducted in two bioreactors continued, with a capacity of 2L: one to monitoring the performance of the activated sludge system without the addition of PAC and another to monitoring the performance of biological treatment using 2,0 g/L of PAC. The degradation of organic matter through activated sludge turned to physical adsorption associated with the addition of CAP promoted the values of COD reduction of 360 to 36 mg / L, which corresponds to an average of 90% of removal. It was also observed the reduction of the values of total organic carbon (TOC) of 285 to 86mg / L, which represents an increase of TOC removal of around 10 percentage points, which, probably, can be the portion of persistent organic matter that is not degraded by the biological system without CAP. (author)

  8. Activated carbon derived from chitosan as air cathode catalyst for high performance in microbial fuel cells

    Science.gov (United States)

    Liu, Yi; Zhao, Yong; Li, Kexun; Wang, Zhong; Tian, Pei; Liu, Di; Yang, Tingting; Wang, Junjie

    2018-02-01

    Chitosan with rich of nitrogen is used as carbon precursor to synthesis activated carbon through directly heating method in this study. The obtained carbon is activated by different amount of KOH at different temperatures, and then prepared as air cathodes for microbial fuel cells. Carbon sample treated with double amount of KOH at 850 °C exhibits maximum power density (1435 ± 46 mW m-2), 1.01 times improved, which ascribes to the highest total surface area, moderate micropore and mesoporous structure and the introduction of nitrogen. The electrochemical impedance spectroscopy and powder resistivity state that carbon treated with double amount of KOH at 850 °C possesses lower resistance. The other electrochemical measurements demonstrate that the best kinetic activity make the above treated sample to show the best oxygen reduction reaction activity. Besides, the degree of graphitization of samples increases with the activated temperature increasing, which is tested by Raman. According to elemental analysis and X-ray photoelectron spectroscopy, all chitosan samples are nitrogen-doped carbon, and high content nitrogen (pyridinic-N) improves the electrochemical activity of carbon treated with KOH at 850 °C. Thus, carbon materials derived from chitosan would be an optimized catalyst for oxygen reduction reaction in microbial fuel cell.

  9. Granular activated carbon for removal of organic matter and turbidity from secondary wastewater.

    Science.gov (United States)

    Hatt, J W; Germain, E; Judd, S J

    2013-01-01

    A range of commercial granular activated carbon (GAC) media have been assessed as pretreatment technologies for a downstream microfiltration (MF) process. Media were assessed on the basis of reduction in both organic matter and turbidity, since these are known to cause fouling in MF membranes. Isotherm adsorption analysis through jar testing with supplementary column trials revealed a wide variation between the different adsorbent materials with regard to organics removal and adsorption kinetics. Comparison with previous work using powdered activated carbon (PAC) revealed that for organic removal above 60% the use of GAC media incurs a significantly lower carbon usage rate than PAC. All GACs tested achieved a minimum of 80% turbidity removal. This combination of turbidity and organic removal suggests that GAC would be expected to provide a significant reduction in fouling of a downstream MF process with improved product water quality.

  10. Scanning transmission electron microscopy analysis of Ge(O)/(graphitic carbon nitride) nanocomposite powder

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, Masahiro [JEOL USA Inc., 11 Dearborn Road, Peabody, MA 01960 (United States); Sompetch, Kanganit [Department of Chemistry and Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sarakonsri, Thapanee, E-mail: tsarakonsri@gmail.com [Department of Chemistry and Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Shiojiri, Makoto [Kyoto Institute of Technology, Kyoto 606-8585 (Japan); School of Science and Engineering, University of Toyama, Toyama 930-8555 (Japan)

    2015-12-15

    Analytical electron microscopy has revealed the structure of particles that were synthesized by chemical reaction of GeO{sub 2} with NaBH{sub 4} in the basic solution including graphitic carbon nitride (g-C{sub 3}N{sub 4}) powders. The g-C{sub 3}N{sub 4} was arranged by recrystallization of melamine at 600 °C under N{sub 2} gas atmosphere. The samples were dried at 60 °C or 180 °C for 4 h. The g-C{sub 3}N{sub 4} was observed as lamellae of several ten nm or less in size and had an amorphous-like structure with a distorted lattice in an area as small as a few hundred pm in size. The reaction product was Ge(O) particles as fine as several nm in size and composed of Ge and O atoms. Most of the particles must be of GeO{sub 2−x} with the amorphous-like structure that has also a distorted lattice in an area of a few hundred pm in size. In the sample dried at 60 °C, the particles were found to be dispersed in a wide area on the g-C{sub 3}N{sub 4} lamella. It is hard to recognize those particles in TEM images. The particles in the sample dried at 180 °C became larger and were easily observed as isolated lumps. Hence, these powders can be regarded as GeO{sub 2}/g-C{sub 3}N{sub 4} or Ge/GeO{sub 2}/g-C{sub 3}N{sub 4} nanocomposites, and expected to be applicable to anode materials for high energy Li-ion batteries due to Ge catalysis effect, accordingly. - Graphical abstract: STEM analysis of Ge(O)/(graphitic carbon nitride) nanocomposite powder. - Highlights: • Graphitic (g)-C{sub 3}N{sub 4} powder was prepared at 600 °C by recrystallization of melamine. • Ge(O) was prepared by chemical reaction in a solution including the g-C{sub 3}N{sub 4} powders. • The products can be regarded as GeO{sub 2}/g-C{sub 3}N{sub 4} or Ge/GeO{sub 2}/g-C{sub 3}N{sub 4} nanocomposites. • GeO{sub 2} was amorphous several-nm particles and g-C{sub 3}N{sub 4} was amorphous lamella of several 10 nm in size. • We expect them to be applicable for high energy Li-ion battery anode

  11. The Specification of Cement Powders for Waste Encapsulation Processes at Sellafield site

    International Nuclear Information System (INIS)

    Angus, M.; Borwick, J.; Cann, G.; Hayes, M.; McLuckie, B.; Jowsey, J.

    2012-01-01

    Requirements are described for Portland Cement (CEM I), Ground Granulated Blast-furnace Slag (GGBS) and Fly Ash (FA) powders used for the encapsulation of Intermediate Level Radioactive Waste (ILW) in UK, with particular reference to Sellafield site encapsulation processes. Differences between the powders used by the UK nuclear industry and the equivalent British and European cement standards are explained. Research over the last 20 years to respond to changes in the performance of these powders is summarised and options for dealing with potential future changes are discussed. These include the use of special blends of GGBS to achieve the desired flow properties or alternatively poly-carboxylate super-plasticizers to produce grouts with consistent performance using cement powders with a wide range of composition. (authors)

  12. Optimization of carbon nanotube powder growth using low pressure floating catalytic chemical vapor deposition

    International Nuclear Information System (INIS)

    Chen, Y.; Sun, Z.; Li, Y.N.; Tay, B.K.

    2006-01-01

    A new approach to synthesize carbon nanotube (CNT) powders has been achieved by using the floating catalyst method below atmospheric pressure. Scanning electron microscopy, Raman spectroscopy and high-resolution transmission electron microscopy were utilized to characterize the CNTs samples. Using ferrocene (FeC 10 H 10 ) as catalyst precursor, cyclohexane (C 6 H 12 ) as carbon source, H 2 as carrier gas and thiophene (C 4 H 4 S) as promoter, it is found that the pressure of 15 kPa, temperature of 650 deg. C and H 2 flow rate of 60 sccm would be the optimization condition for synthesis of high quality CNTs. This method is economical and easily scalable for synthesis of CNTs

  13. Preparation of powders Ag3PO4 and study of their photocatalytic activity

    International Nuclear Information System (INIS)

    Badurova, K.

    2014-01-01

    In our thesis we dealt with preparing powders of Ag 3 PO 4 by using Na 2 HPO 4 ·12H 2 O and Na 3 PO 4 ·12H 2 O as two different precursors. Samples were prepared by precipitation and mechanochemical methods. Photocatalytic efficiency of individual samples was studied by irradiation of suspensions of prepared powders with methylene blue (MB) solution and with phenol solution using source of light similar to solar light. Photocatalytic efficiency was determined via method of determination of total organic carbon (TOC) as the time dependence of phenol concentration and also via monitoring spectrophotometric parameters of solution as the time dependence of MB solution colouring intensity. Effect of sample preparation method on photocatalytic efficiency and morphology of particles was studied. After that, samples were characterised by X-ray powder diffraction method (XRD), scanning electron microscopy (SEM) and Raman spectroscopy (authors)

  14. Polarization-Dependent Measurements of Molecular Super Rotors with Oriented Angular Momenta

    Science.gov (United States)

    Murray, Matthew J.; Toro, Carlos; Liu, Qingnan; Mullin, Amy S.

    2014-05-01

    Controlling molecular motion would enable manipulation of energy flow between molecules. Here we have used an optical centrifuge to investigate energy transfer between molecular super rotors with oriented angular momenta. The polarizable electron cloud of the molecules interacts with the electric field of linearly polarized light that angularly accelerates over the time of the optical pulse. This process drives molecules into high angular momentum states that are oriented with the optical field and have energies far from equilibrium. High resolution transient IR spectroscopy reveals the dynamics of collisional energy transfer for these super excited rotors. The results of this study leads to a more fundamental understanding of energy balance in non-equilibrium environments and the physical and chemical properties of gases in a new regime of energy states. Results will be presented for several super rotor species including carbon monoxide, carbon dioxide, and acetylene. Polarization-dependent measurements reveal the extent to which the super rotors maintain spatial orientation of high angular momentum states.

  15. In vitro adsorption of sodium pentobarbital by SuperChar, USP and Darco G-60 activated charcoals

    International Nuclear Information System (INIS)

    Curd-Sneed, C.D.; Parks, K.S.; Bordelon, J.G.; Stewart, J.J.

    1987-01-01

    This study was designed to examine the in vitro adsorption of sodium pentobarbital by three activated charcoals. Solutions of sodium pentobarbital (20 mM) were prepared in distilled water and in 70% sorbitol (w/v). Radiolabeled ( 14 C) sodium pentobarbital was added to each solution to serve as a concentration marker. Two ml of each drug solution was added to test tubes containing 40 mg of either Darco G-60, USP, or SuperChar activated charcoal. The drug-charcoal mixtures were incubated at 37 degrees C for O, 2.5, 5, 7.5 or 10 min. Equilibrium, indicated by a constant percentage of drug bound for two consecutive time periods, was established immediately for the aqueous mixtures and for Darco G-60 in sorbitol. The time to equilibrium was prolonged for USP (2.5 min) and SuperChar (5 min) in the presence of sorbitol. In the second series of experiments, solutions of sodium pentobarbital (1.25 to 160 mM) were prepared in either distilled water or sorbitol. Amount of drug bound by 10 to 320 mg of activated charcoal within a 10 min incubation period was determined. Scatchard analysis determined maximum binding capacity (Bmax) and dissociation constants (Kd) for each activated charcoal. In water, Bmax (mumoles/gm) was greatest for SuperChar (1141), followed by USP (580) and Darco G-60 (381), while the Kd's did not differ. Sorbitol did not change the Bmax or Kd of USP or Darco G-60, but the additive significantly decreased the Bmax (717) and increased the Kd for SuperChar (3.3 to 10.1 mM). The results suggest that relative binding capacity of activated charcoal is directly proportional to surface area, and that sorbitol significantly reduces sodium pentobarbital binding to SuperChar

  16. Graphene: powder, flakes, ribbons, and sheets.

    Science.gov (United States)

    James, Dustin K; Tour, James M

    2013-10-15

    Graphene's unique physical and electrical properties (high tensile strength, Young's modulus, electron mobility, and thermal conductivity) have led to its nickname of "super carbon." Graphene research involves the study of several different physical forms of the material: powders, flakes, ribbons, and sheets and others not yet named or imagined. Within those forms, graphene can include a single layer, two layers, or ≤10 sheets of sp² carbon atoms. The chemistry and applications available with graphene depend on both the physical form of the graphene and the number of layers in the material. Therefore the available permutations of graphene are numerous, and we will discuss a subset of this work, covering some of our research on the synthesis and use of many of the different physical and layered forms of graphene. Initially, we worked with commercially available graphite, with which we extended diazonium chemistry developed to functionalize single-walled carbon nanotubes to produce graphitic materials. These structures were soluble in common organic solvents and were better dispersed in composites. We developed an improved synthesis of graphene oxide (GO) and explored how the workup protocol for the synthesis of GO can change the electronic structure and chemical functionality of the GO product. We also developed a method to remove graphene layers one-by-one from flakes. These powders and sheets of GO can serve as fluid loss prevention additives in drilling fluids for the oil industry. Graphene nanoribbons (GNRs) combine small width with long length, producing valuable electronic and physical properties. We developed two complementary syntheses of GNRs from multiwalled carbon nanotubes: one simple oxidative method that produces GNRs with some defects and one reductive method that produces GNRs that are less defective and more electrically conductive. These GNRs can be used in low-loss, high permittivity composites, as conductive reinforcement coatings on Kevlar

  17. Exploration of the Role of Heat Activation in Enhancing Serpentine Carbon Sequestration Reactions

    International Nuclear Information System (INIS)

    McKelvy, M.J.; Chizmeshya, A.V.G.; Diefenbacher, J.; Bearat, H.; Wolf, G.

    2005-01-01

    As compared with other candidate carbon sequestration technologies, mineral carbonation offers the unique advantage of permanent disposal via geologically stable and environmentally benign carbonates. The primary challenge is the development of an economically viable process. Enhancing feedstock carbonation reactivity is key. Heat activation dramatically enhances aqueous serpentine carbonation reactivity. Although the present process is too expensive to implement, the materials characteristics and mechanisms that enhance carbonation are of keen interest for further reducing cost. Simultaneous thermogravimetric and differential thermal analysis (TGA/DTA) of the serpentine mineral lizardite was used to isolate a series of heat-activated materials as a function of residual hydroxide content at progressively higher temperatures. Their structure and composition are evaluated via TGA/DTA, X-ray powder diffraction (including phase analysis), and infrared analysis. The meta-serpentine materials that were observed to form ranged from those with longer range ordering, consistent with diffuse stage-2 like interlamellar order, to an amorphous component that preferentially forms at higher temperatures. The aqueous carbonation reaction process was investigated for representative materials via in situ synchrotron X-ray diffraction. Magnesite was observed to form directly at 15 MPa CO 2 and at temperatures ranging from 100 to 125 C. Carbonation reactivity is generally correlated with the extent of meta-serpentine formation and structural disorder.

  18. Annihilation characteristics of positrons in oxide powders in relation to catalytic activities

    International Nuclear Information System (INIS)

    Ito, K.; Ohtsu, Y.; Tanigawa, S.; Enomura, A.; Tsuda, N.

    1982-01-01

    The annihilation chaaracteristics in magnesium oxide powders were studied by the measurements of Doppler broadening of annihilation radiations. MgO powders are well known as a solid base and are utilized as a catalyst for the reactions which start by extracting protons from molecules such as decomposition of alcohol. The isochronal annealing behavior of annihilation characteristics in the process Mg(OH) 2 → MgO was found to correspond just to the change in the number of basic points, specific surface area and catalytic activities in some reactions. From the results of the thermal equilibrium measurements of MgO powders after dehydration, the temperature dependence of S parameter can be considered as the thermal activation process of the escape of positrons from trapped states at surface to form positroniums. The derived value of this activation energy was 0.187 eV. (Auth.)

  19. Sorption activity investigation of ultrafine powders of high temperature melting point compounds in atmospheric pressure conditions

    International Nuclear Information System (INIS)

    Rudneva, V.V.

    2006-01-01

    A study is made in saturation with gas in the air for ultradispersed chromium carbonitride and boride powders synthesized in a nitrogen plasma jet according to three variants: from elements, from oxides, from chromium trichloride. It is established that in the air on temperature increasing the powders adsorb considerable amounts of oxygen and water vapor. This results in surface oxidation of powder particles and a loss in specific combination of properties. Preliminary vacuum heat treatment is shown to decrease sharply the rate of atmospheric gas adsorption. The quantity of adsorbed gases is dependent on a carbon monoxide concentration in a particle surface layer and the availability of adsorption centers. The number of such centers in the layer can be controlled by vacuum heat treatment conditions. The interaction of the powders with atmospheric gases is concluded to be of adsorption-diffusion nature [ru

  20. Production of rare earth polishing powders in Russia

    International Nuclear Information System (INIS)

    Kosynkin, V.D.; Ivanov, E.N.; Kotrekhov, V.A.; Shtutza, M.G.; Grabko, A.I.

    1998-01-01

    Full text: Russia is a potent producer of polishing powders made of rare earth material presented as an extensive and well developed base. Considering the reserves, the facilities predisposition and the polishing agent (cerium dioxide) content the chief mineral source is loparite, apatite and monazite. The production of rare earth polishing powders is based on specially developed continuous technological processes, corrosion-proof equipment, ensuring a high and stable production quality. A special attention is paid to the radiation safety of the powders. The initial material for the rare earth polishing powders based on loparite is the fusion cake of rare earth chlorides obtained at that mineral chlorination. The technology of the polishing powder production from the REE fusion cake includes the following stages: dissolution of the REE fusion cake chlorides; - thorough cleaning of the REE fusion cake chlorides from radioactive and non-rare-earth impurities; chemical precipitation of REE carbonates, obtaining middlings with proper material and granulometric composition, thermal treatment of precipitated carbonates followed with the operations of drying and roasting; classification of roasted oxides, obtaining end products - polishing powders. The production of fluorine-containing powders includes the stage of their fluorination after the stage of carbonate precipitation. The stabilizing doping can be introduced both into the middlings during one of the technological process of powders manufacturing and into the end product. Rare earth polishing powders are manufactured in Russia by the Share Holding Company 'Chepetz Mechanical Plant' (ChMP Co.), the city of Glasov. The plant produces a number of polishing materials, such as; polishing powder Optinol, containing at least 50% by mass of cerium dioxide, used in the mass production of optical and other articles; polishing powder Optinol-10 with doping to improve the sedimentary and aggregate stability of the solid phase

  1. Direct fabrication of ordered mesoporous carbons with super-micropore/small mesopore using mixed triblock copolymers.

    Science.gov (United States)

    Li, Peng; Song, Yan; Tang, Zhihong; Yang, Guangzhi; Yang, Junhe

    2014-01-01

    Ordered mesoporous carbons (OMCs) have been prepared by the strategy of evaporation-induced organic-organic self-assembly method by employing a mixture of amphiphilic triblock copolymers poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) and reverse PPO-PEO-PPO as templates, with soluble in ethanol, low-molecular-weight phenolic resin as precursor, followed by carbonization. It has been found that the as prepared OMCs with porosity that combines super-micropore and small mesopore size distributed from 0.8 to 4 nm, which bridges the pore size from 2 to 3 nm and also for the diversification of the soft-templating synthesis of OMCs. Furthermore, the results showed that the OMCs obtained have mesophase transition from cylindrical p6 mm to centered rectangular c2 mm structure by simply tuning the ratio of PPO-PEO-PPO/PEO-PPO-PEO. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. [The endothelium injuries caused by homocysteine and treatmental effects of Tongxinluo powder].

    Science.gov (United States)

    Liang, Jun-Qing; Wu, Yi-Ling; Xu, Hai-Bo; Zhao, Shao-Hua; Jia, Zhen-Hua; Zhang, Qiu-Yan; Wei, Cong; Dong, Xiao-Wei

    2008-02-01

    To observe the effect of homocysteine (HCY) on the function of endothelium cell, and to discuss the possible mechanisms that Tongxinluo super powder affected. Healthy male Wistar rats were divided into randomly the control group, the model group, the Tongxinluo group. The effect of Ach on isolated rat thoracic aorta in vitro was examined, the microcirculation was observed by microcirculation meter, the activity of SOD and GSH-PX and content of NO, MDA, ET, Ang II, TXA2, PGI2 was detected. Compared with control group, the effect of Ach on isolated rat thoracic aorta in vitro weakened markablely (P homocystein might cause the contracted and dilated function decreased, it might get involved in endothelium disfunction as a result of the massive free radicals production and diastolic-contract factors balance disorder induced by high homocystein. (2) Tongxinluo powder could improve the function of endothelium-dependment dilation induced by high homocystein, that associated with inhibitting the excessive production of free radicals, and improved function of endothelium.

  3. Comparative Study on Carbonated and Non-Carbonated Recycled Aggregate Concrete with Glass Powder as Partial Replacement for OPC

    Directory of Open Access Journals (Sweden)

    Abhishek Patil

    2017-12-01

    Full Text Available Recycled aggregates (RA possess the ability to be recycled, if undesirable properties are counteracted viz, porous mortar attached to it, with high water absorption and low density, this technique, accelerated carbonation can be one such to technique to counteract undesirable properties of RA, replacement of 20% of cement by glass powder assists in reducing w/c ratio[1][6] when used in concrete[2] suppress ASR reaction[1], this paper explains a new possibility of recycling concrete, work done and findings for improvising Recycled aggregate concrete (RAC and exploring the feasibility for use of RA in the near future.

  4. Superheated water pretreatment combined with CO2 activation/regeneration of the exhausted activated carbon used in the treatment of industrial wastewater.

    Science.gov (United States)

    Xiao, Jin; Yu, Bailie; Zhong, Qifan; Yuan, Jie; Yao, Zhen; Zhang, Liuyun

    2017-10-01

    This paper examines a novel method of regenerating saturated activated carbon after adsorption of complex phenolic, polycyclic aromatic hydrocarbons with low energy consumption by using superheated water pretreatment combined with CO 2 activation. The effects of the temperature of the superheated water, liquid-solid ratio, soaking time, activation temperature, activation time, and CO 2 flow rate of regeneration and adsorption of coal-powdered activated carbon (CPAC) were studied. The results show that the adsorption capacity of iodine values on CPAC recovers to 102.25% of the fresh activated carbon, and the recovery rate is 79.8% under optimal experimental conditions. The adsorption model and adsorption kinetics of methylene blue on regenerated activated carbon (RAC) showed that the adsorption process was in accordance with the Langmuir model and the pseudo-second-order kinetics model. Furthermore, the internal diffusion process was the main controlling step. The surface properties, Brunauer-Emmett-Teller (BET) surface area, and pore size distribution were characterized by Fourier transform infrared spectroscopy (FT-IR) and BET, which show that the RAC possesses more oxygen-containing functional groups with a specific surface area of 763.39 m 2 g -1 and a total pore volume of 0.3039 cm 3 g -1 . Micropores account for 79.8% and mesopores account for 20.2%.

  5. Effects of Carbonization Parameters of Moso-Bamboo-Based Porous Charcoal on Capturing Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Pei-Hsing Huang

    2014-01-01

    Full Text Available This study experimentally analyzed the carbon dioxide adsorption capacity of Moso-bamboo- (Phyllostachys edulis- based porous charcoal. The porous charcoal was prepared at various carbonization temperatures and ground into powders with 60, 100, and 170 meshes, respectively. In order to understand the adsorption characteristics of porous charcoal, its fundamental properties, namely, charcoal yield, ash content, pH value, Brunauer-Emmett-Teller (BET surface area, iodine number, pore volume, and powder size, were analyzed. The results show that when the carbonization temperature was increased, the charcoal yield decreased and the pH value increased. Moreover, the bamboo carbonized at a temperature of 1000°C for 2 h had the highest iodine sorption value and BET surface area. In the experiments, charcoal powders prepared at various carbonization temperatures were used to adsorb 1.854% CO2 for 120 h. The results show that the bamboo charcoal carbonized at 1000°C and ground with a 170 mesh had the best adsorption capacity, significantly decreasing the CO2 concentration to 0.836%. At room temperature and atmospheric pressure, the Moso-bamboo-based porous charcoal exhibited much better CO2 adsorption capacity compared to that of commercially available 350-mesh activated carbon.

  6. Powdered activated carbon adsorption of two fishy odorants in water: Trans,trans-2,4-heptadienal and trans,trans-2,4-decadienal.

    Science.gov (United States)

    Li, Xin; Wang, Jun; Zhang, Xiaojian; Chen, Chao

    2015-06-01

    Powdered activated carbon (PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal (HDE) and trans,trans-2,4-decadienal (DDE), was investigated. Both the pseudo first-order and the pseudo second-order kinetic models well described the kinetics curves, and DDE was more readily removed by PAC. In isotherm tests, both Freundlich and Modified Freundlich isotherms fitted the experimental data well. PAC exhibited a higher adsorption capacity for DDE than for HDE, which could be ascribed to the difference in their hydrophobicity. The calculated thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated an exothermic and spontaneous adsorption process. PAC dosage, pH, and natural organic matter (NOM) presence were found to influence the adsorption process. With increasing PAC dosage, the pseudo first-order and pseudo second-order rate constants both increased. The value of pH had little influence on HDE or DDE molecules but altered the surface charge of PAC, and the maximum adsorption capacity occurred at pH9. The presence of NOM, especially the fraction with molecular weight less than 1k Dalton, hindered the adsorption. The study showed that preloaded NOM impaired the adsorption capacity of HDE or DDE more severely than simultaneously fed NOM did. Copyright © 2015. Published by Elsevier B.V.

  7. Effect of Powder-Suspended Dielectric on the EDM Characteristics of Inconel 625

    Science.gov (United States)

    Talla, Gangadharudu; Gangopadhyay, S.; Biswas, C. K.

    2016-02-01

    The current work attempts to establish the criteria for powder material selection by investigating the influence of various powder-suspended dielectrics and machining parameters on various EDM characteristics of Inconel 625 (a nickel-based super alloy) which is nowadays regularly used in aerospace, chemical, and marine industries. The powders include aluminum (Al), graphite, and silicon (Si) that have significant variation in their thermo-physical characteristics. Results showed that powder properties like electrical conductivity, thermal conductivity, density, and hardness play a significant role in changing the machining performance and the quality of the machined surface. Among the three powders, highest material removal rate was observed for graphite powder due to its high electrical and thermal conductivities. Best surface finish and least radial overcut (ROC) were attained using Si powder. Maximum microhardness was found for Si due to its low thermal conductivity and high hardness. It is followed by graphite and aluminum powders. Addition of powder to the dielectric has increased the crater diameter due to expansion of plasma channel. Powder-mixed EDM (PMEDM) was also effective in lowering the density of surface cracks with least number of cracks obtained with graphite powder. X-ray diffraction analysis indicated possible formation of metal carbides along with grain growth phenomenon of Inconel 625 after PMEDM.

  8. Removal of surfactants from water by adsorption on activated carbon and advanced oxidation process; Eliminacion de surfactantes de las aguas mediante adsorcion sobre carbon activado y oxidacion avanzada

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Diaz, J. D.; Sanchez Polo, M.; Rivera Utrilla, J.; Bautista, M. I.

    2007-07-01

    The objective of this study was to analyze the elimination process of surfactants from water, using sodium dode-cilbencenesulfonate (SDBS) as model compound, by means of adsorption on activated carbons as well as different processes of advanced oxidation (O{sub 3}, O{sub 3}/H{sub 2}O{sub 2} and O{sub 3}/activated carbon). Results obtained have shown that the activated carbons used have a high efficiency to eliminate SDBS from waters which was enhanced when the adsorption process was carried out in the presence of bacteria. With regard to the oxidation processes studied, the results have indicated that the efficiency in the elimination of SDBS from water of the system based on the simultaneous use of O{sub 3} and powder activated carbon (PAC) is much higher than those of the other systems studied (O{sub 3},O{sub 3}/H{sub 2}O{sub 2}). (Author) 15 refs.

  9. Carbon nanofibers grafted on activated carbon as an electrode in high-power supercapacitors.

    Science.gov (United States)

    Gryglewicz, Grażyna; Śliwak, Agata; Béguin, François

    2013-08-01

    A hybrid electrode material for high-power supercapacitors was fabricated by grafting carbon nanofibers (CNFs) onto the surface of powdered activated carbon (AC) through catalytic chemical vapor deposition (CCVD). A uniform thin layer of disentangled CNFs with a herringbone structure was deposited on the carbon surface through the decomposition of propane at 450 °C over an AC-supported nickel catalyst. CNF coating was controlled by the reaction time and the nickel content. The superior CNF/AC composite displays excellent electrochemical performance in a 0.5 mol L(-1) solution of K2 SO4 due to its unique structure. At a high scan rate (100 mV s(-1) ) and current loading (20 A g(-1) ), the capacitance values were three- and fourfold higher than those for classical AC/carbon black composites. Owing to this feature, a high energy of 10 Wh kg(-1) was obtained over a wide power range in neutral medium at a voltage of 0.8 V. The significant enhancement of charge propagation is attributed to the presence of herringbone CNFs, which facilitate the diffusion of ions in the electrode and play the role of electronic bridges between AC particles. An in situ coating of AC with short CNFs (below 200 nm) is a very attractive method for producing the next generation of carbon composite materials with a high power performance in supercapacitors working in neutral medium. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Optimized preparation for large surface area activated carbon from date (Phoenix dactylifera L.) stone biomass

    International Nuclear Information System (INIS)

    Danish, Mohammed; Hashim, Rokiah; Ibrahim, M.N. Mohamad; Sulaiman, Othman

    2014-01-01

    The preparation of activated carbon from date stone treated with phosphoric acid was optimized using rotatable central composite design of response surface methodology (RSM). The chemical activating agent concentration and temperature of activation plays a crucial role in preparation of large surface area activated carbons. The optimized activated carbon was characterized using thermogravimetric analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The results showed that the larger surface area of activated carbon from date stone can be achieved under optimum activating agent (phosphoric acid) concentration, 50.0% (8.674 mol L −1 ) and activation temperature, 900 °C. The Brunauer–Emmett–Teller (BET) surface area of optimized activated carbon was found to be 1225 m 2  g −1 , and thermogravimetric analysis revealed that 55.2% mass of optimized activated carbon was found thermally stable till 900 °C. The leading chemical functional groups found in the date stone activated carbon were aliphatic carboxylic acid salt ν(C=O) 1561.22 cm −1 and 1384.52 cm −1 , aliphatic hydrocarbons ν(C–H) 2922.99 cm −1 (C–H sym./asym. stretch frequency), aliphatic phosphates ν(P–O–C) 1054.09 cm −1 , and secondary aliphatic alcohols ν(O–H) 3419.81 cm −1 and 1159.83 cm −1 . - Highlights: • RSM optimization was done for the production of large surface area activated carbon. • Two independent variables with two responses were selected for optimization. • Characterization was done for surface area, morphology and chemical constituents. • Optimized date stone activated carbon achieved surface area 1225 m 2  g −1

  11. Preparation of La{sub 0.75}Sr{sub 0.25}Cr{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} fine powders by carbonate coprecipitation for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Sang Bu; Cho, Pyeong-Seok; Cho, Yoon Ho; Lee, Dokyol; Lee, Jong-Heun [Department of Materials Science and Engineering, Korea University, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea)

    2010-01-01

    A range of La{sub 0.75}Sr{sub 0.25}Cr{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} (LSCM) powders is prepared by the carbonate coprecipitation method for use as anodes in solid oxide fuel cells. The supersaturation ratio (R = [(NH{sub 4}){sub 2}CO{sub 3}]/([La{sup 3+}] + [Sr{sup 2+}] + [Cr{sup 3+}] + [Mn{sup 2+}])) during the coprecipitation determines the relative compositions of La, Sr, Cr, and Mn. The composition of the precursor approaches the stoichiometric one at the supersaturation range of 4 {<=} R {<=} 12.5, whereas Sr and Mn components are deficient at R < 4 and excessive at R = 25. The fine and phase-pure LSCM powders are prepared by heat treatment at very low temperature (1000 C) at R = 7.5 and 12.5. By contrast, the solid-state reaction requires a higher heat-treatment temperature (1400 C). The catalytic activity of the LSCM electrodes is enhanced by using carbonate-derived powders to manipulate the electrode microstructures. (author)

  12. Sorption of carbamazepine by commercial graphene oxides: a comparative study with granular activated carbon and multiwalled carbon nanotubes.

    Science.gov (United States)

    Cai, Nan; Larese-Casanova, Philip

    2014-07-15

    Graphene nanosheet materials represent a potentially new high surface area sorbent for the treatment of endocrine disrupting compounds (EDCs) in water. However, sorption behavior has been reported only for laboratory graphene prepared by a laborious and hazardous graphite exfoliation process. A careful examination of commercially available, clean, high-volume produced graphene materials should reveal whether they are appropriate for sorbent technologies and which physicochemical properties most influence sorption performance. In this study, three commercially available graphene oxide powders of various particle sizes, specific surface areas, and surface chemistries were evaluated for their sorption performance using carbamazepine and nine other EDCs and were compared to that of conventional granular activated carbon (GAC) and multi-walled carbon nanotubes (MWCNTs). Sorption kinetics of carbamazepine on graphene oxide powders was rapid and reversible with alcohol washing, consistent with π-π interactions. The various sorption extents as described by Freundlich isotherms were best explained by available surface area, and only the highest surface area graphene oxide (771 m(2)/g) out-performed GAC and MWCNTs. Increasing pH caused more negative surface charge, a twofold decrease in sorption of anionic ibuprofen, a onefold increase in sorption of cationic atenolol, and no change for neutral carbamazepine, highlighting the role of electrostatic interactions. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Improvement of activated carbons as oxygen reduction catalysts in neutral solutions by ammonia gas treatment and their performance in microbial fuel cells

    KAUST Repository

    Watson, Valerie J.; Nieto Delgado, Cesar; Logan, Bruce E.

    2013-01-01

    Commercially available activated carbon (AC) powders from different precursor materials (peat, coconut shell, coal, and hardwood) were treated with ammonia gas at 700 C to improve their performance as oxygen reduction catalysts in neutral p

  14. Quantitative analysis of mineral powders by DRIFTS: Determination of SrCO3 in superconductor precursor powders

    DEFF Research Database (Denmark)

    Bak, J.; Kindl, B.

    1997-01-01

    An application of diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) has been demonstrated to be able to determine small concentrations, down to the 100-ppm level, of carbonates in powdery superconductor (SPC) precursor samples, The detection of carbonates in SPC precursor powders...

  15. A new technique for the strengthening of aluminum tungsten inert gas weld metals: using carbon nanotube/aluminum composite as a filler metal.

    Science.gov (United States)

    Fattahi, M; Nabhani, N; Rashidkhani, E; Fattahi, Y; Akhavan, S; Arabian, N

    2013-01-01

    The effect of multi-walled carbon nanotube (MWCNT) on the mechanical properties of aluminum multipass weld metal prepared by the tungsten inert gas (TIG) welding process was investigated. High energy ball milling was used to disperse MWCNT in the aluminum powder. Carbon nanotube/aluminum composite filler metal was fabricated for the first time by hot extrusion of ball-milled powders. After welding, the tensile strength, microhardness and MWCNT distribution in the weld metal were investigated. The test results showed that the tensile strength and microhardness of weld metal was greatly increased when using the filler metal containing 1.5 wt.% MWCNT. Therefore, according to the results presented in this paper, it can be concluded that the filler metal containing MWCNT can serve as a super filler metal to improve the mechanical properties of TIG welds of Al and its alloys. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jilin [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Gu, Yunle [School of Material Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Li, Zili [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Wang, Weimin, E-mail: wangwm@hotmail.com [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Fu, Zhengyi [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2013-06-01

    Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH{sub 4} played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B{sub 2}O{sub 3} and KBH{sub 4} as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH{sub 4} played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed.

  17. Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

    International Nuclear Information System (INIS)

    Wang, Jilin; Gu, Yunle; Li, Zili; Wang, Weimin; Fu, Zhengyi

    2013-01-01

    Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH 4 played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B 2 O 3 and KBH 4 as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH 4 played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed

  18. Removal of radio N-nitrosodimethylamine (NDMA from drinking water by coagulation and Powdered Activated Carbon (PAC adsorption

    Directory of Open Access Journals (Sweden)

    C.-K. Choi

    2009-10-01

    Full Text Available The presence of N-nitrosodimethylamine (NDMA in drinking water supplies has raised concern over its removal by common drinking water treatment processes. However, only limited studies have been examined to evaluate the potential removal of NDMA by numerous water treatment technologies within a realistic range (i.e., sub μg/L of NDMA levels in natural water due to analytical availability. In this study, a simple detection method based on scintillation spectroscopy has been used to quantify the concentration of 14C-labeled NDMA at various ratios of sample to scintillation liquid. Without sample pretreatment, the method detection limits are 0.91, 0.98, 1.23, and 1.45 ng/L of NDMA at scintillation intensity ratios of 10:10, 5:15, 15:5, and 2.5:17.5 (sample: scintillation liquid, respectively. The scintillation intensity in all cases is linear (R2>0.99 and is in the range of 0 to 100 ng/L of NDMA. In addition, because scintillation intensity is independent of solution pH, conductivity, and background electrolyte ion types, a separate calibration curve is unnecessary for NDMA samples at different solution conditions. Bench-scale experiments were performed to simulate individual treatment processes, which include coagulation and adsorption by powdered activated carbon (PAC, as used in a drinking water treatment plant, and biosorption, a technique used in biological treatment of waste water. The results show that coagulation and biosorption may not be appropriate mechanisms to remove NDMA (i.e., hydrophilic based on its low octanol-water partitioning coefficient, Log Kow=0.57. However, relatively high removal of NDMA (approximately 50% was obtained by PAC at high PAC dosages and longer contact times.

  19. Electrochemical characteristics and microstructure of activated carbon powder supercapacitors for energy storage

    International Nuclear Information System (INIS)

    Gonsalves, T.C.; Faria, R.N.; Silva, F. M.; Vieira, L.S.; Casini, J.C.S.

    2016-01-01

    In recent years, extensive investigations have concentrated on the study and improvement of supercapacitors electrode materials. The electric devices produced with these materials are used for stored energy over time periods ranging from seconds to several days. The main factor determining the energy storage time of a supercapacitor is its self-discharge rate. This property concerns to the gradual decrease in the electric potential that occurs when the supercapacitor terminals are left unconnected to either a charging circuit or an electric load. Self-discharge is attenuated with a decrease in room temperature and lifetime is enhanced. This paper addresses this aspect and reports the results of a work carried out on a systematic study with supercapacitors with nominal capacitance of 1.0 rated at a DC potential of 5.5 V and 10.0 F at 2,7 V. The specific capacitance, internal resistance and self-discharge of commercial activated carbon electrode supercapacitors have been investigated. Specific capacitances were measured in this study using cyclic voltammetry (CV). Specific capacitances of 44.4 and 66.7 Fg-1 were determined for distinct carbon electrodes supercapacitors. Self-discharge were carried out at room temperature and close to the freezing point. Internal resistances of the supercapacitors were calculated using the discharge curve at room temperature. The microstructures of the electrode material have been investigated using scanning electron microscopy (SEM). (author)

  20. Electrochemical characteristics and microstructure of activated carbon powder supercapacitors for energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, T.C.; Faria, R.N. [Universidade de Sao Paulo (USP), SP (Brazil); Silva, F. M.; Vieira, L.S.; Casini, J.C.S., E-mail: julio.casini@ifro.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Rondonia (IFRO), Calama, RO (Brazil)

    2016-07-01

    In recent years, extensive investigations have concentrated on the study and improvement of supercapacitors electrode materials. The electric devices produced with these materials are used for stored energy over time periods ranging from seconds to several days. The main factor determining the energy storage time of a supercapacitor is its self-discharge rate. This property concerns to the gradual decrease in the electric potential that occurs when the supercapacitor terminals are left unconnected to either a charging circuit or an electric load. Self-discharge is attenuated with a decrease in room temperature and lifetime is enhanced. This paper addresses this aspect and reports the results of a work carried out on a systematic study with supercapacitors with nominal capacitance of 1.0 rated at a DC potential of 5.5 V and 10.0 F at 2,7 V. The specific capacitance, internal resistance and self-discharge of commercial activated carbon electrode supercapacitors have been investigated. Specific capacitances were measured in this study using cyclic voltammetry (CV). Specific capacitances of 44.4 and 66.7 Fg-1 were determined for distinct carbon electrodes supercapacitors. Self-discharge were carried out at room temperature and close to the freezing point. Internal resistances of the supercapacitors were calculated using the discharge curve at room temperature. The microstructures of the electrode material have been investigated using scanning electron microscopy (SEM). (author)

  1. Characterization and observation of water-based nanofluids quench medium with carbon particle content variation

    Science.gov (United States)

    Yahya, S. S.; Harjanto, S.; Putra, W. N.; Ramahdita, G.; Kresnodrianto, Mahiswara, E. P.

    2018-05-01

    Recently, nanofluids have been widely used in heat treatment industries as quench medium with better quenching performance. The thermal conductivity of nanofluids is higher compared to conventional quench medium such as polymer, water, brine, and petroleum-based oil. This characteristic can be achieved by mixing high thermal conductivity particles in nanometer scale with a fluid as base. In this research, carbon powder and distilled water were used as nanoparticles and base respectively. The carbon source used in this research was laboratory grade carbon powder, and activated carbon as a cheaper alternative source. By adjusting the percentage of dispersed carbon particles, thermal conductivity of nanofluids could be controlled as needed. To obtain nanoscale carbon particles, planetary ball mill was used to grind laboratory-grade carbon and active carbon powder to further decrease its particle size. This milling method will provide nanoparticles with lower production cost. Milling speed and duration were set at 500 rpm and 15 hours. Scanning electron microscope (SEM) and Energy Dispersive X-Ray (EDX) were carried out respectively to determine the particle size, material identification, particle morphology. The carbon nanoparticle content in nanofluids quench mediums for this research were varied at 0.1, 0.3, and 0.5 % vol. Furthermore, these mediums were used to quench AISI 1045 carbon steel samples which had been annealed at 1000 °C. Hardness testing and metallography observation were then conducted to check the effect of different quench medium in steel samples. Preliminary characterizations showed that the carbon particle dimension after milling was hundreds of nanometers, or still in sub-micron range. Therefore, the milling process parameters are need to be optimized further. EDX observation in laboratory-grade carbon powder showed that the powder was pure carbon as expected for, but in activated carbon has some impurities. The nanofluid itself, however, was

  2. Activated carbon from biomass

    Science.gov (United States)

    Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

    2013-06-01

    Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

  3. Adsorption of steroid micropollutants on polymer-based spherical activated carbon (PBSAC).

    Science.gov (United States)

    Tagliavini, Matteo; Engel, Fabio; Weidler, Peter Georg; Scherer, Torsten; Schäfer, Andrea Iris

    2017-09-05

    Removal and interaction mechanisms of four different steroid micropollutants, estrone (E1), estradiol (E2), progesterone (P) and testosterone (T) were determined for different types of polymer-based spherical activated carbon (PBSAC). Higher than 90% removal and significantly faster kinetics compared to conventional granular activated carbon (GAC) were observed, while performance was comparable with powdered activated carbon (PAC). No influence of pH in the range 2-12 was determined, while the presence of humic acid (HA) reduced both the removal and the kinetic by up to 20%. PBSAC was characterized in terms of morphology and material properties. The low oxygen content was identified as the main cause for the high performance observed. This was attributed to the enhancement of the hydrophobic effect between PBSAC and hormones and the reduced interactions between PBSAC and water. The ratio of micropollutant size (∼0.8nm) and average pore size (1-2nm) proved ideal for both micropollutant adsorption and HA exclusion. The homogenous size, spherical shape and surface smoothness of PBSAC did not influence adsorption negatively and make PBSAC a very promising sorbent for a vast range of applications, in particular for the removal of micropollutants in water treatment applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. [Study on influence between activated carbon property and immobilized biological activated carbon purification effect].

    Science.gov (United States)

    Wang, Guang-zhi; Li, Wei-guang; He, Wen-jie; Han, Hong-da; Ding, Chi; Ma, Xiao-na; Qu, Yan-ming

    2006-10-01

    By means of immobilizing five kinds of activated carbon, we studied the influence between the chief activated carbon property items and immobilized bioactivated carbon (IBAC) purification effect with the correlation analysis. The result shows that the activated carbon property items which the correlation coefficient is up 0.7 include molasses, abrasion number, hardness, tannin, uniform coefficient, mean particle diameter and effective particle diameter; the activated carbon property items which the correlation coefficient is up 0.5 include pH, iodine, butane and tetrachloride. In succession, the partial correlation analysis shows that activated carbon property items mostly influencing on IBAC purification effect include molasses, hardness, abrasion number, uniform coefficient, mean particle diameter and effective particle diameter. The causation of these property items bringing influence on IBAC purification is that the activated carbon holes distribution (representative activated carbon property item is molasses) provides inhabitable location and adjust food for the dominance bacteria; the mechanical resist-crash property of activated carbon (representative activated carbon property items: abrasion number and hardness) have influence on the stability of biofilm; and the particle diameter size and distribution of activated carbon (representative activated carbon property items: uniform coefficient, mean particle diameter and effective particle diameter) can directly affect the force of water in IBAC filter bed, which brings influence on the dominance bacteria immobilizing on activated carbon.

  5. Effect of carbon on mechanical properties of powder-processed Fe ...

    Indian Academy of Sciences (India)

    The present paper records the results of mechanical tests on iron-phosphorus powder alloys which were made using a hot powder forging technique. In this process mild steel encapsulated powders were hot forged into slabs, hot rolled and annealed to relieve the residual stresses. These alloys were characterized in terms ...

  6. An Asymmetric Supercapacitor Based on Activated Porous Carbon Derived from Walnut Shells and NiCo₂O₄ Nanoneedle Arrays Electrodes.

    Science.gov (United States)

    Wang, Wei; Qi, Jiqiu; Sui, Yanwei; He, Yezeng; Meng, Qingkun; Wei, Fuxiang; Jin, Yunxue

    2018-08-01

    A facile method was utilized to convert a common biomass of walnut shells into activated porous carbon by carbonization and activation with nitricacid treatment. The obtained activated carbon (WSs-2) exhibited excellent electrochemical performance with high specific capacitance of 137 F · g-1 at 1 A · g-1 and super cycling performance of 96% capacitance retention at 5 A · g-1 after 5000 cycles. In addition, NiCo2O4 nanoneedle arrays with good electrochemical properties were successfully prepared by a simple hydrothermal method. An aqueous asymmetric supercapacitor (ASC) device based on WSs-2 and NiCo2O4 was assembled, which delivered 21 Wh · kg-1 at a power density of 424.5 W · kg-1, and maintained 19 Wh · kg-1 at power density of 4254 W · kg-1 as well as excellent cycling stability of 99.3% capacitance retention after 5000 cycles at 4 A · g-1. Through this method, low-cost, environmentally friendly and large-scale carbon materials can be fabricated and applied in supercapacitor electrodes.

  7. Investigation of effective parameters in preparation and controlling lithium fluoride nano size powder

    International Nuclear Information System (INIS)

    Naderi, S.; Sarraf Mamoory, F.; Riahi Noori, N.

    2007-01-01

    In this research, the reaction of LiOH + HF+LiF+H 2 O has been selected and some precipitation parameters such as pH, temperature, time, super saturation, q d agitation type have been studied, and controlled. The morphology, phase analysis and particle size of the resulting powders were analyzed by SEM, XRD and LPSA. Finally, at temperature 2S d ig C , pH of about 2-3, reaction time less than 1 sec, and agitation by ultrasonic bath, the pure nano lithium fluoride powders of about 100 nm were produced

  8. Super-quantum curves from super-eigenvalue models

    Energy Technology Data Exchange (ETDEWEB)

    Ciosmak, Paweł [Faculty of Mathematics, Informatics and Mechanics, University of Warsaw,ul. Banacha 2, 02-097 Warsaw (Poland); Hadasz, Leszek [M. Smoluchowski Institute of Physics, Jagiellonian University,ul. Łojasiewicza 11, 30-348 Kraków (Poland); Manabe, Masahide [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Sułkowski, Piotr [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E. California Blvd, Pasadena, CA 91125 (United States)

    2016-10-10

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  9. Super-quantum curves from super-eigenvalue models

    International Nuclear Information System (INIS)

    Ciosmak, Paweł; Hadasz, Leszek; Manabe, Masahide; Sułkowski, Piotr

    2016-01-01

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  10. Super-quantum curves from super-eigenvalue models

    Science.gov (United States)

    Ciosmak, Paweł; Hadasz, Leszek; Manabe, Masahide; Sułkowski, Piotr

    2016-10-01

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/ β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  11. Determination of carbon content of UO2, (U, Gd)O2 and (U, Pu)O2 powders and sintered pellets - Combustion in a high-frequency induction furnace -Infrared absorption spectrometry

    International Nuclear Information System (INIS)

    2008-01-01

    This International Standard describes a method for determining the carbon content in UO 2 , (U,Gd)O 2 and (U,Pu)O 2 powder and sintered pellets by combustion in an induction furnace and infrared absorption spectroscopy measurement. It is applicable for determining 10 μg/g to 500 μg/g of carbon in UO 2 , (U,Gd)O 2 and (U,Pu)O 2 powder and pellets. The sample is heated to a temperature above 1500 deg. C in an induction furnace, under pure oxygen atmosphere, to convert any carbon compounds to carbon dioxide gas. The resulting carbon dioxide gas is filtered and dried before measurement using infrared spectroscopy to measure the carbon dioxide signal at 2350 cm -1 . The result is converted into the carbon content of the material analysed

  12. Identification and super-resolution imaging of ligand-activated receptor dimers in live cells

    Science.gov (United States)

    Winckler, Pascale; Lartigue, Lydia; Giannone, Gregory; de Giorgi, Francesca; Ichas, François; Sibarita, Jean-Baptiste; Lounis, Brahim; Cognet, Laurent

    2013-08-01

    Molecular interactions are key to many chemical and biological processes like protein function. In many signaling processes they occur in sub-cellular areas displaying nanoscale organizations and involving molecular assemblies. The nanometric dimensions and the dynamic nature of the interactions make their investigations complex in live cells. While super-resolution fluorescence microscopies offer live-cell molecular imaging with sub-wavelength resolutions, they lack specificity for distinguishing interacting molecule populations. Here we combine super-resolution microscopy and single-molecule Förster Resonance Energy Transfer (FRET) to identify dimers of receptors induced by ligand binding and provide super-resolved images of their membrane distribution in live cells. By developing a two-color universal-Point-Accumulation-In-the-Nanoscale-Topography (uPAINT) method, dimers of epidermal growth factor receptors (EGFR) activated by EGF are studied at ultra-high densities, revealing preferential cell-edge sub-localization. This methodology which is specifically devoted to the study of molecules in interaction, may find other applications in biological systems where understanding of molecular organization is crucial.

  13. Self-standing silicon-carbon nanotube/graphene by a scalable in situ approach from low-cost Al-Si alloy powder for lithium ion batteries

    Science.gov (United States)

    Cai, Hongyan; Han, Kai; Jiang, Heng; Wang, Jingwen; Liu, Hui

    2017-10-01

    Silicon/carbon (Si/C) composite shows great potential to replace graphite as lithium-ion battery (LIB) anode owing to its high theoretical capacity. Exploring low-cost scalable approach for synthesizing Si/C composites with excellent electrochemical performance is critical for practical application of Si/C anodes. In this study, we rationally applied a scalable in situ approach to produce Si-carbon nanotube (Si-CNT) composite via acid etching of commercial inexpensive micro-sized Al-Si alloy powder and CNT mixture. In the Si-CNT composite, ∼10 nm Si particles were uniformly deposited on the CNT surface. After combining with graphene sheets, a flexible self-standing Si-CNT/graphene paper was fabricated with three-dimensional (3D) sandwich-like structure. The in situ presence of CNT during acid-etching process shows remarkable two advantages: providing deposition sites for Si atoms to restrain agglomeration of Si nanoparticles after Al removal from Al-Si alloy powder, increasing the cross-layer conductivity of the paper anode to provide excellent conductive contact sites for each Si nanoparticles. When used as binder-free anode for LIBs without any further treatment, in situ addition of CNT especially plays important role to improve the initial electrochemical activity of Si nanoparticles synthesized from low-cost Al-Si alloy powder, thus resulting in about twice higher capacity than Si/G paper anode. The self-standing Si-CNT/graphene paper anode exhibited a high specific capacity of 1100 mAh g-1 even after 100 cycles at 200 mA g-1 current density with a Coulombic efficiency of >99%. It also showed remarkable rate capability improvement compared to Si/G paper without CNT. The present work demonstrates a low-cost scalable in situ approach from commercial micro-sized Al-Si alloy powder for Si-based composites with specific nanostructure. The Si-CNT/graphene paper is a promising anode candidate with high capacity and cycling stability for LIBs, especially for the

  14. Activated carbons and gold

    International Nuclear Information System (INIS)

    McDougall, G.J.; Hancock, R.D.

    1980-01-01

    The literature on activated carbon is reviewed so as to provide a general background with respect to the effect of source material and activation procedure on carbon properties, the structure and chemical nature of the surface of the activated carbon, and the nature of absorption processes on carbon. The various theories on the absorption of gold and silver from cyanide solutions are then reviewed, followed by a discussion of processes for the recovery of gold and silver from cyanide solutions using activated carbon, including a comparison with zinc precipitation

  15. Electrochemical behavior of H3PW12O40/ acid-activated bentonite powders

    Directory of Open Access Journals (Sweden)

    Mojović Zorica

    2012-01-01

    Full Text Available Electrochemical behavior of 12-tungstophosphoric acid (HPW/acid-activated bentonite (AAB powders with various loadings of HPW was investigated. The physicochemical properties of the prepared powders were examined by X-ray powder diffraction, nitrogen adsorption-desorption isotherms, atomic force microscopy and cyclic voltammetry measurements. The results indicated that the prepared powders are composed mainly of oriented domains of large rock blocks, probably resulting from a preferable deposition of bentonite particles having a face-to-face interaction. The particles had a mainly disordered mesoporous structure with a pore volume that varied according to the pore size in the range of 2-50 nm. In addition, the particles had crystallite size between 4.9 and 9.0 nm. The electrocatalytic activities of prepared HPW/Aelectrodes were studied in the oxidation of NO2-ions and the results revealed that the electrodes possessed relatively higher nitrite oxidation currents than Aelectrode. The best electroactivity was observed for HPW3/Aelectrode (AAB+20 wt. % HPW and the limit of detection (3σ was determined as 8 μM.

  16. Carbon activity meter

    International Nuclear Information System (INIS)

    Roy, P.; Krankota, J.L.

    1975-01-01

    A carbon activity meter utilizing an electrochemical carbon cell with gaseous reference electrodes having particular application for measuring carbon activity in liquid sodium for the LMFBR project is described. The electrolyte container is electroplated with a thin gold film on the inside surface thereof, and a reference electrode consisting of CO/CO 2 gas is used. (U.S.)

  17. Impedance spectroscopic analysis of composite electrode from activated carbon/conductive materials/ruthenium oxide for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Taer, E.; Awitdrus,; Farma, R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Physics, Faculty of Mathematics and Natural Sciences, University of Riau, 28293 Pekanbaru, Riau (Indonesia); Deraman, M., E-mail: madra@ukm.my; Talib, I. A.; Ishak, M. M.; Omar, R.; Dolah, B. N. M.; Basri, N. H.; Othman, M. A. R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Kanwal, S. [ICCBS, H.E.J. Research Institute of Chemistry, University of Karachi, 75270 Karachi (Pakistan)

    2015-04-16

    Activated carbon powders (ACP) were produced from the KOH treated pre-carbonized rubber wood sawdust. Different conductive materials (graphite, carbon black and carbon nanotubes (CNTs)) were added with a binder (polivinylidene fluoride (PVDF)) into ACP to improve the supercapacitive performance of the activated carbon (AC) electrodes. Symmetric supercapacitor cells, fabricated using these AC electrodes and 1 molar H{sub 2}SO{sub 4} electrolyte, were analyzed using a standard electrochemical impedance spectroscopy technique. The addition of graphite, carbon black and CNTs was found effective in reducing the cell resistance from 165 to 68, 23 and 49 Ohm respectively, and increasing the specific capacitance of the AC electrodes from 3 to 7, 17, 32 F g{sup −1} respectively. Since the addition of CNTs can produce the highest specific capacitance, CNTs were chosen as a conductive material to produce AC composite electrodes that were added with 2.5 %, 5 % and 10 % (by weight) electro-active material namely ruthenium oxide; PVDF binder and CNTs contents were kept at 5 % by weight in each AC composite produced. The highest specific capacitance of the cells obtained in this study was 86 F g{sup −1}, i.e. for the cell with the resistance of 15 Ohm and composite electrode consists of 5 % ruthenium oxide.

  18. Activated, coal-based carbon foam

    Science.gov (United States)

    Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

    2004-12-21

    An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

  19. Assessment of PCDD/F and PBDD/F Emissions from Coal-fired Power Plants during Injection of Brominated Activated Carbon for Mercury Control

    Science.gov (United States)

    The effect of the injection of brominated powdered activated carbon (Br-PAC) on the emission of brominated and chlorinated dioxins and furans in coal combustion flue gas has been evaluated. The tests were performed at two U.S. Department of Energy (DOE) demonstration sites where ...

  20. Industrial testing of modified clay powders by the ''Permneft''' organization

    Energy Technology Data Exchange (ETDEWEB)

    Matytsyn, V I; Kosivchenko, A M; Ryabchenko, V I; Shishov, V A

    1980-01-01

    VNIIKRneft' has developed a modified clay powder based on Cherkask bentonite with one ton of solution resulting in 20-28 cubic meters of powder per TU 39-08-123-77 formula. The modification stems from the type of bentonite treatment used. Bentonite is used in the amount of 3-5% of the total mass and the treatment involves the use of 0.3% calcium soda, copolymer methacrylic acid with M-14VV methacrylate. These reagents induce processes of change within the clay. The carbonate-nitrate activity serves to penthiatize the clay particles and the reagent solution which accompany the process of coagulation in the polymer structure, and in turn, increases the incidence of viscosity in the newly emerging systems. Tests indicate that the use of modified clay powder enhances drill bit pass-through. The large quantity of drilling solution resulting from one ton of modified clay powder further enhances the practical aspects of this system and reduces overall expenditures for solution treatment and clay powder while permitting the reduction of expenditures for other chemical reagents. Such economic benefits have been confirmed by industrial testing.

  1. Super jackstraws and super waterwheels

    International Nuclear Information System (INIS)

    Cho, Jin-Ho

    2007-01-01

    We construct various new BPS states of D-branes preserving 8 supersymmetries. These include super Jackstraws (a bunch of scattered D- or (p, q)-strings preserving supersymmetries), and super waterwheels (a number of D2-branes intersecting at generic angles on parallel lines while preserving supersymmetries). Super D-Jackstraws are scattered in various dimensions but are dynamical with all their intersections following a common null direction. Meanwhile, super (p, q)-Jackstraws form a planar static configuration. We show that the SO(2) subgroup of SL(2, R), the group of classical S-duality transformations in IIB theory, can be used to generate this latter configuration of variously charged (p, q)-strings intersecting at various angles. The waterwheel configuration of D2-branes preserves 8 supersymmetries as long as the 'critical' Born-Infeld electric fields are along the common direction

  2. Photocatalytic degradation of an azo-dye on TiO2/activated carbon composite material.

    Science.gov (United States)

    Andriantsiferana, C; Mohamed, E F; Delmas, H

    2014-01-01

    A sequential adsorption/photocatalytic regeneration process to remove tartrazine, an azo-dye in aqueous solution, has been investigated. The aim ofthis work was to compare the effectiveness of an adsorbent/photocatalyst composite-TiO2 deposited onto activated carbon (AC) - and a simple mixture of powders of TiO2 and AC in same proportion. The composite was an innovative material as the photocatalyst, TiO2, was deposited on the porous surface ofa microporous-AC using metal-organic chemical vapour deposition in fluidized bed. The sequential process was composed of two-batch step cycles: every cycle alternated a step of adsorption and a step of photocatalytic oxidation under ultra-violet (365 nm), at 25 degreeC and atmospheric pressure. Both steps, adsorption and photocatalytic oxidation, have been investigated during four cycles. For both materials, the cumulated amounts adsorbed during four cycles corresponded to nearly twice the maximum adsorption capacities qmax proving the photocatalytic oxidation to regenerate the adsorbent. Concerning photocatalytic oxidation, the degree of mineralization was higher with the TiO2/AC composite: for each cycle, the value of the total organic carbon removal was 25% higher than that obtained with the mixture powder. These better photocatalytic performances involved better regeneration than higher adsorbed amounts for cycles 2, 3 and 4. Better performances with this promising material - TiO2 deposited onto AC - compared with TiO2 powder could be explained by the vicinity of photocatalytic and AC adsorption sites.

  3. Carbon activation process for increased surface accessibility in electrochemical capacitors

    Science.gov (United States)

    Doughty, Daniel H.; Eisenmann, Erhard T.

    2001-01-01

    A process for making carbon film or powder suitable for double capacitor electrodes having a capacitance of up to about 300 F/cm.sup.3 is disclosed. This is accomplished by treating in aqueous nitric acid for a period of about 5 to 15 minutes thin carbon films obtained by carbonizing carbon-containing polymeric material having a high degree of molecular directionality, such as polyimide film, then heating the treated carbon film in a non-oxidizing atmosphere at a non-graphitizing temperature of at least 350.degree. C. for about 20 minutes, and repeating alternately the nitric acid step and the heating step from 7 to 10 times. Capacitors made with this carbon may find uses ranging from electronic devices to electric vehicle applications.

  4. Catalytic activity of Co/SiO2 and Co/TiO2 nanosized systems in the oxidation of carbon monoxide

    Science.gov (United States)

    Kelyp, A. A.; Smirnova, N. P.; Oleksenko, L. P.; Lutsenko, L. V.; Oranskaya, E. I.; Ripko, A. P.

    2013-06-01

    The effects of the preparation procedure, active component concentration, and conditions of formation of nanosized cobalt-containing systems based on TiO2 and SiO2 mesoporous powders on their catalytic activity in the oxidation of carbon monoxide were studied. The active phase in the systems was cobalt spinel CoCo2O4 found in all samples. High catalytic activity was found in the samples characterized by relatively high contents of surface active centers (cobalt cations with octahedral surroundings).

  5. Nonlinear Super Integrable Couplings of Super Classical-Boussinesq Hierarchy

    Directory of Open Access Journals (Sweden)

    Xiuzhi Xing

    2014-01-01

    Full Text Available Nonlinear integrable couplings of super classical-Boussinesq hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then, its super Hamiltonian structures were established by using super trace identity. As its reduction, nonlinear integrable couplings of the classical integrable hierarchy were obtained.

  6. Quantitative Analysis of Graphene Sheet Content in Wood Char Powders during Catalytic Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Yan-Jia Liou; Wu-Jang Huang

    2013-01-01

    The quantitative characterization of the graphene sheet content in carbon-containing materials is arguable and has not yet been developed.The authors report on a feasible method to characterize graphene sheet content quantitatively in pyrolized carbon materials using an X-ray diffraction (XRD) spectrometer.A direct carbonation at 300 ℃ followed by catalytic pyrolysis (heat-treatment temperature was set at 700-1400 ℃)under a vacuum condition was used for turning wood waste into pyrolized wood char powders.The graphene content in the samples was calculated through an analysis of full width at half maximum (FWHM) of the carbon (100) crystal plane at around 42°-43° in XRD.Results showed that the FWHM and the calculated graphene sheet content of pyrolized wood char powders depended on the heat-treatment temperature,and the FWHM of wood char powder with well-developed graphene sheets (100%) was determined to be 5.0.In addition,the trend to 100% graphene sheet-contained pyrolized carbon powder was obtained at a heattreatment temperature of 2700 ℃.The resistivity of the wood char powder with 100% graphene sheets was predicted to be 0.01 Ω cm,close to our experimental data of 0.012 and 0.006 Ω cm for commercial graphite and graphene products,respectively.

  7. Manufacture of uranium dioxide powder

    International Nuclear Information System (INIS)

    Becker, M.

    1976-01-01

    Uranium dioxide powder is prepared by the AUC (ammonium uranyl carbonate) method. Supplementing the known process steps, the AUC, after separation from the mother liquor, is washed with an ammonium hydrogen carbonate or an NH 4 OH solution and is subsequently post-treated with a liquid which reduces the surface tension of the residual water in an AUC. Such a liquid is, for instance, alcohol

  8. Activated carbon material

    International Nuclear Information System (INIS)

    Evans, A.G.

    1978-01-01

    Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards

  9. Electroactive thermoset shape memory polymer nanocomposite filled with nanocarbon powders

    International Nuclear Information System (INIS)

    Leng, Jinsong; Lan, Xin; Liu, Yanju; Du, Shanyi

    2009-01-01

    This paper concerns an electroactive thermoset styrene-based shape memory polymer (SMP) nanocomposite filled with nanosized (30 nm) carbon powders. With an increase of the incorporated nanocarbon powders of the SMP composite, its glass transition temperature (T g ) decreases and storage modulus increases. Due to the high micro-porosity and homogeneous distributions of nanocarbon powders in the SMP matrix, the SMP composite shows good electrical conductivity with a percolation of about 3.8%. This percolation threshold is slightly lower than that of many other carbon-based conductive polymer composites. Consequently, due to the relatively high electrical conductivity, a sample filled with 10 vol% nanocarbon powders shows a good electroactive shape recovery performance heating by a voltage of 30 V above a transition temperature of 56–69 °C

  10. Formation of nanocrystalline TiC from titanium and different carbon sources by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Jia Haoling [Key Lab of Liquid Structure and Heredity of Materials, Jingshi Road 73, Jinan 250061, Shandong (China); Zhang Zhonghua [Key Lab of Liquid Structure and Heredity of Materials, Jingshi Road 73, Jinan 250061, Shandong (China)], E-mail: zh_zhang@sdu.edu.cn; Qi Zhen [Key Lab of Liquid Structure and Heredity of Materials, Jingshi Road 73, Jinan 250061, Shandong (China); Liu Guodong [School of Materials Science and Engineering, Shandong University, Jingshi Road 73, Jinan 250061 (China); Bian Xiufang [Key Lab of Liquid Structure and Heredity of Materials, Jingshi Road 73, Jinan 250061, Shandong (China)

    2009-03-20

    In this paper, the formation of nanocrystalline TiC from titanium powders and different carbon resources by mechanical alloying (MA) has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental results show that nanocrystalline TiC can be synthesized from Ti powders and different carbon resources (activated carbon, carbon fibres or carbon nanotubes) by MA at room temperature. Titanium and different carbon resources have a significant effect on the Ti-C reaction and the formation of TiC during MA. Moreover, the formation of nanocrystalline TiC is governed by a gradual diffusion reaction mechanism during MA, regardless of different carbon resources.

  11. Adsorption of Reactive Red M-2BE dye from water solutions by multi-walled carbon nanotubes and activated carbon.

    Science.gov (United States)

    Machado, Fernando M; Bergmann, Carlos P; Fernandes, Thais H M; Lima, Eder C; Royer, Betina; Calvete, Tatiana; Fagan, Solange B

    2011-09-15

    Multi-walled carbon nanotubes and powdered activated carbon were used as adsorbents for the successful removal of Reactive Red M-2BE textile dye from aqueous solutions. The adsorbents were characterised by infrared spectroscopy, N(2) adsorption/desorption isotherms and scanning electron microscopy. The effects of pH, shaking time and temperature on adsorption capacity were studied. In the acidic pH region (pH 2.0), the adsorption of the dye was favourable using both adsorbents. The contact time to obtain equilibrium at 298K was fixed at 1h for both adsorbents. The activation energy of the adsorption process was evaluated from 298 to 323K for both adsorbents. The Avrami fractional-order kinetic model provided the best fit to the experimental data compared with pseudo-first-order or pseudo-second-order kinetic adsorption models. For Reactive Red M-2BE dye, the equilibrium data were best fitted to the Liu isotherm model. Simulated dyehouse effluents were used to check the applicability of the proposed adsorbents for effluent treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Properties of Ni-Mo steel prepared from premixed and prealloyed powder in sintered, forged and annealed state

    International Nuclear Information System (INIS)

    Salak, A.; Hrubjak, M.

    Investigated were 2Ni-0.5Mo steel specimens made of premixed powder on the base of Hametag iron and of ATST-A prealloyed powder with graphite additives of 0.3% and 0.8%. In the sintered and forged state, specimens prepared from premixed powder exhibit better strength properties compared with those made of prealloyed ATST-A powder. After annealing, the carbon content has a different bearing on both systems. With premixed powder steel of 0.6% carbon content the tensile strength amounts to 1,800 MPa whilst that of prealloyed steel specimens with 0.2% carbon content is about 1,240 MPa. (author)

  13. Bioturbation and dissolved organic matter enhance contaminant fluxes from sediment treated with powdered and granular activated carbon

    NARCIS (Netherlands)

    Kupryianchyk, D.; Noori, A.; Rakowska, M.I.; Grotenhuis, J.T.C.; Koelmans, A.A.

    2013-01-01

    Sediment amendment with activated carbon (AC) is a promising technique for in situ sediment remediation. To date it is not clear whether this technique sufficiently reduces sediment-to-water fluxes of sediment-bound hydrophobic organic chemicals (HOCs) in the presence of bioturbators. Here, we

  14. Analysing 'super-participation' in online third spaces

    NARCIS (Netherlands)

    Graham, Todd; Wright, Scott; Cantijoch, Marta; Gibson, Rachel; Ward, Stephen

    2014-01-01

    This chapter focuses on our attempts to overcome the methodological challenges of 'super-participation' in online discussion forums, focusing on the participatory patterns and discursive activity of what we call 'super-participants'. Our principal contribution in this area (Graham and Wright 2013)

  15. Physico-chemical properties and solubility behaviour of multi-substituted hydroxyapatite powders containing silicon

    International Nuclear Information System (INIS)

    Sprio, S.; Tampieri, A.; Landi, E.; Sandri, M.; Martorana, S.; Celotti, G.; Logroscino, G.

    2008-01-01

    Hydroxyapatite powders characterized by ionic substitutions both in anionic and cationic sites were successfully prepared by synthesis in aqueous medium. The process parameters were set up to allow the simultaneous substitution of the foreign ions, namely carbonate, magnesium and silicon in the crystallographic site of calcium and phosphorus, keeping in count the competition which arises between atoms destined to occupy the same crystallographic site. The chemico-physical properties of the powders were investigated through several analytical techniques, i.e. X-ray diffraction, infrared spectroscopy, atomic emission spectroscopy and thermo-gravimetric analysis. The results show that the utilization of sodium hydrogen-carbonate as a reactant allows the entering of carbonate into the HA structure, mainly in phosphate position, while sodium is eliminated during the process of the powder washing. The entering of silicon in the HA structure progressively reduces its crystallinity, as also carbonate ions do. Silicate and carbonate ions can enter simultaneously into the HA structure, in biological-like amounts, although they compete for the occupation of the phosphate site; the powder crystallinity is strongly reduced as the content of the two substituting ions increases, so that a limit molar concentration exists where the apatite structure collapses and an amorphous phase forms with the simultaneous formation of crystalline calcium carbonate. Solubility tests, carried out at physiological conditions, reveal an increased calcium release in the HA powders containing silicon compared to the silicon-free HA; the solubility behaviour of the multi-substituted HA powders at physiological conditions makes these materials promising as bioactive bone scaffold, as they are able to continuously supply ions which are essential for the process of bone reconstruction

  16. Biodegradation of thermoplastic starch/eggshell powder composites.

    Science.gov (United States)

    Bootklad, Munlika; Kaewtatip, Kaewta

    2013-09-12

    Thermoplastic starch (TPS) was prepared using compression molding and chicken eggshell was used as a filler. The effect of the eggshell powder (EP) on the properties of TPS was compared with the effect of commercial calcium carbonate (CC). The organic compound on the surface of the eggshell powder acted as a coupling agent that resulted in a strong adhesion between the eggshell powder and the TPS matrix, as confirmed by SEM micrographs. The biodegradation was determined by the soil burial test. The TPS/EP composites were more rapidly degraded than the TPS/CC composites. In addition, the eggshell powder improved the water resistance and thermal stability of the TPS. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. The super-classical-Boussinesq hierarchy and its super-Hamiltonian structure

    International Nuclear Information System (INIS)

    Si-Xing, Tao; Tie-Cheng, Xia

    2010-01-01

    Based on the constructed Lie superalgebra, the super-classical-Boussinesq hierarchy is obtained. Then, its super-Hamiltonian structure is obtained by making use of super-trace identity. Furthermore, the super-classical-Boussinesq hierarchy is also integrable in the sense of Liouville. (general)

  18. Structural Evolution of Q-Carbon and Nanodiamonds

    Science.gov (United States)

    Gupta, Siddharth; Bhaumik, Anagh; Sachan, Ritesh; Narayan, Jagdish

    2018-04-01

    This article provides insights pertaining to the first-order phase transformation involved in the growth of densely packed Q-carbon and nanodiamonds by nanosecond laser melting and quenching of diamond-like carbon (DLC) thin films. DLC films with different sp 3 content were melted rapidly in a controlled way in super-undercooled state and quenched, leading to formation of distinct nanostructures, i.e., nanodiamonds, Q-carbon, and Q-carbon nanocomposites. This analysis provides direct evidence of the dependence of the super-undercooling on the structural evolution of Q-carbon. Finite element heat flow calculations showed that the super-undercooling varies monotonically with the sp 3 content. The phenomenon of solid-liquid interfacial instability during directional solidification from the melt state is studied in detail. The resulting lateral segregation leads to formation of cellular filamentary Q-carbon nanostructures. The dependence of the cell size and wavelength at the onset of instability on the sp 3 content of DLC thin films was modeled based on perturbation theory.

  19. Development of precipitation strengthened brass with Ti and Sn alloying elements additives by using water atomized powder via powder metallurgy route

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shufeng, E-mail: shufengli@hotmail.com [Joining and Welding Research Institute, Osaka University, Osaka (Japan); Imai, Hisashi; Kondoh, Katsuyoshi [Joining and Welding Research Institute, Osaka University, Osaka (Japan); Kojima, Akimichi; Kosaka, Yoshiharu [San-Etsu Metals Co. LTD., 1892 OHTA, Tonami, Toyama (Japan); Yamamoto, Koji; Takahashi, Motoi [Nippon Atomized Metal Powders Corporation, 87-16, Nishi-Sangao, Noda, Chiba (Japan)

    2012-08-15

    Effect of Ti and Sn alloying elements on microstructure and mechanical properties of 60/40 brass has been studied via the powder metallurgy (P/M) route. The water-atomized BS40-0.6Sn1.0Ti (Cu40wt%Zn-0.6wt%Sn1.0wt%Ti) pre-alloyed powder was consolidated at various temperatures within range of 400-600 Degree-Sign C using spark plasma sintering (SPS) and hot extrusion was carried out at 500 Degree-Sign C. Effects of extrusion temperature on microstructure and tensile strength were investigated by employing SEM-EDS/EBSD, TEM, XRD and tensile test. Results indicated that super-saturated solid solution Ti and Sn elements created high chemical potential for a precipitate reaction in rapidly solidified brass powder, which showed significant strengthening effects on the extruded sample consolidated at lower temperature. Solid solubility of Ti in brass matrix decreased with increasing of sintering temperature, thus resulted in degradation of mechanical properties. Consequently, lower hot processing temperature is necessary to obtain excellent mechanical properties for BS40-0.6Sn1.0Ti during sintering and extrusion. An yield strength of 398 MPa and ultimate tensile strength of 615 MPa were achieved, they respectively showed 31.3% and 22.9% higher values than those of extruded Cu40Zn brass. -- Graphical abstract: The Ti and Sn alloying elements additions showed significant grain refinement on Cu40Zn-0.6Sn1.0Ti brass (b) as comparing with that of the conventional Cu40Zn brass (a), detected by electron backscatter diffraction (EBSD) technique. The grain boundaries maps of (a) BS40 (b) BS40-0.6Sn1.0Ti SPS compact sintered at 400 Degree-Sign C reveals by electron backscatter diffraction (EBSD) technique. Highlights: Black-Right-Pointing-Pointer Alloying elements Ti and Sn are proposed as additives in 60/40 brass. Black-Right-Pointing-Pointer Super-saturated Ti in powder creates high chemical potential for precipitation. Black-Right-Pointing-Pointer CuSn{sub 3}Ti{sub 5

  20. Activated carbon derived from harmful aquatic plant for high stable supercapacitors

    Science.gov (United States)

    Li, Jiangfeng; Wu, Qingsheng

    2018-01-01

    Considering cost and environmental protection, the harmful aquatic plant altemanthera philoxeroides derived carbon material with super high specific surface area (2895 m2 g-1) is an ideal electrode material for supercapacitor. The structure and composition of these carbon materials were characterized by SEM, EDS, XPS and BET measurements. The obtained material exhibits a maximum specific capacitance of 275 F g-1 at 0.5 A g-1 and retains a capacitance of 210 F g-1 even at 50 A g-1. In addition, it also shows excellent capacity retention of 5000 cycles at 10 A g-1.

  1. MECHANICAL ALLOYING SYNTHESIS OF FORSTERITE-DIOPSIDE NANOCOMPOSITE POWDER FOR USING IN TISSUE ENGINEERING

    Directory of Open Access Journals (Sweden)

    Sorour Sadeghzade

    2015-03-01

    Full Text Available In present study the pure forsterite-diopside nanocomposite powder was successfully synthesized by the economical method of mechanical alloying and subsequence sintering, for the first time. The starting economical materials were talc (Mg3Si4H2O12, magnesium carbonate (MgCO3 and calcium carbonate (CaCO3 powders. The prepared powder was characterized by thermo gravimetric analysis (TGA, X-ray diffraction (XRD, and scanning electron microscopy (SEM. The results showed preparation of forsterite- diopside nanocomposite powder after 10 h mechanical alloying and sintering at 1200oC for 1 h. The powder crystallite sizes and agglomerated particle sizes were measured about 73 +/- 4 nm and 0.3 - 4 μm, respectively. Absence of enstatite that causes a reduction in mechanical and bioactivity properties of forsterite ceramic, is an important feature of produced powder.

  2. In vitro adsorption study of fluoxetine in activated carbons and activated carbon fibres

    Energy Technology Data Exchange (ETDEWEB)

    Nabais, J.M. Valente; Mouquinho, A.; Galacho, C.; Carrott, P.J.M.; Ribeiro Carrott, M.M.L. [Centro de Quimica de Evora e Departamento de Quimica da Universidade de Evora, Rua Romao Ramalho no. 59, 7000-671 Evora (Portugal)

    2008-05-15

    We study the in vitro adsorption of fluoxetine hydrochloride by different adsorbents in simulated gastric and intestinal fluid, pH 1.2 and 7.5, respectively. The tested materials were two commercial activated carbons, carbomix and maxsorb MSC30, one activated carbon fibre produced in our laboratory and also three MCM-41 samples, also produced by us. Selected samples were modified by liquid phase oxidation and thermal treatment in order to change the surface chemistry without significant modifications to the porous characteristics. The fluoxetine adsorption follows the Langmuir model. The calculated Q{sub 0} values range from 54 to 1112 mg/g. A different adsorption mechanism was found for the adsorption of fluoxetine in activated carbon fibres and activated carbons. In the first case the most relevant factors are the molecular sieving effect and the dispersive interactions whereas in the activated carbons the mechanism seams to be based on the electrostatic interactions between the fluoxetine molecules and the charged carbon surface. Despite the different behaviours most of the materials tested have potential for treating potential fluoxetine intoxications. (author)

  3. Pulsed Neutron Powder Diffraction for Materials Science

    Science.gov (United States)

    Kamiyama, T.

    2008-03-01

    The accelerator-based neutron diffraction began in the end of 60's at Tohoku University which was succeeded by the four spallation neutron facilities with proton accelerators at the High Energy Accelerator Research Organization (Japan), Argonne National Laboratory and Los Alamos Laboratory (USA), and Rutherford Appleton Laboratory (UK). Since then, the next generation source has been pursued for 20 years, and 1MW-class spallation neutron sources will be appeared in about three years at the three parts of the world: Japan, UK and USA. The joint proton accelerator project (J-PARC), a collaborative project between KEK and JAEA, is one of them. The aim of the talk is to describe about J-PARC and the neutron diffractometers being installed at the materials and life science facility of J-PARC. The materials and life science facility of J-PARC has 23 neutron beam ports and will start delivering the first neutron beam of 25 Hz from 2008 May. Until now, more than 20 proposals have been reviewed by the review committee, and accepted proposal groups have started to get fund. Those proposals include five polycrystalline diffractometers: a super high resolution powder diffractometer (SHRPD), a 0.2%-resolution powder diffractometer of Ibaraki prefecture (IPD), an engineering diffractometers (Takumi), a high intensity S(Q) diffractometer (VSD), and a high-pressure dedicated diffractometer. SHRPD, Takumi and IPD are being designed and constructed by the joint team of KEK, JAEA and Ibaraki University, whose member are originally from the KEK powder group. These three instruments are expected to start in 2008. VSD is a super high intensity diffractometer with the highest resolution of Δd/d = 0.3%. VSD can measure rapid time-dependent phenomena of crystalline materials as well as glass, liquid and amorphous materials. The pair distribution function will be routinely obtained by the Fourier transiformation of S(Q) data. Q range of VSD will be as wide as 0.01 Å-1stress mapping inside

  4. Carbon aerogels; Les aerogels de carbone

    Energy Technology Data Exchange (ETDEWEB)

    Berthon-Fabry, S.; Achard, P

    2003-06-15

    The carbon aerogel is a nano-porous material at open porosity, electrical conductor. The aerogels morphology is variable in function of the different synthesis parameters. This characteristic offers to the aerogels a better adaptability to many applications: electrodes (super condensers, fuel cells). The author presents the materials elaboration and their applications. It provides also the research programs: fundamental research, realization of super-condenser electrodes, fuel cells electrodes, gas storage materials and opaque materials for thermal insulation. (A.L.B.)

  5. Optically transparent super-hydrophobic thin film fabricated by reusable polyurethane-acrylate (PUA) mold

    Science.gov (United States)

    Park, J.-S.; Park, J.-H.; Lee, D.-W.

    2018-02-01

    In this paper, we describe a simple manufacturing method for producing an optically transparent super-hydrophobic polymer thin film using a reusable photo-curable polymer mold. Soluble photoresist (PR) molds were prepared with under-exposed and under-baked processes, which created unique hierarchical micro/nano structures. The reverse phase of the PR mold was replicated on the surface of polydimethylsiloxane (PDMS) substrates. The unique patterns on the replicated PDMS molds were successfully transferred back to the UV curable polyurethane-acrylate (PUA) using a laboratory-made UV exposure system. Continuous production of the super-hydrophobic PDMS thin film was demonstrated using the reusable PUA mold. In addition, hydrophobic nano-silica powder was sprayed onto the micro/nano structured PDMS surfaces to further improve hydrophobicity. The fabricated PDMS thin films with hierarchical surface texturing showed a water contact angle  ⩾150°. Excellent optical transmittance within the range of visible light of wavelengths between 400-800 nm was experimentally confirmed using a spectrophotometer. High efficiency of the super-hydrophobic PDMS film in optical transparency was also confirmed using solar panels. The fabricated PUA molds are very suitable for use in roll-to-roll or roll-to-plate systems which allow continuous production of super-hydrophobic thin films with an excellent optical transparency.

  6. Effect of incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder on ACE inhibitory activity in fermented milk by L. plantarum LP69.

    Science.gov (United States)

    Shu, Guowei; Yang, Hui; Chen, He; Zhang, Qiuhong; Tian, Yue

    2015-01-01

    Angiotensin I converting enzyme (ACE) plays an important physiological role in regulating hypertension. Lactic acid bacteria are known to produce ACE inhibitory peptides which can lower hypertension during fermentation. The effect of incubation time (0~36 h), inoculum size (3, 4, 5, 6 and 7%, v/v), temperature (25, 30, 35, 40 and 45°C), sterilization time (5, 10, 15, 20 and 25 min), concentration of goat milk powder (8, 10, 12, 14 and 16%, w/v) and whey powder (0.5, 0.6, 0.7, 0.8 and 0.9%, w/v) on ACE inhibitory peptides fermented from goat milk by Lactobacillus plantarum LP69 was investigated using single factor experiment. The optimal incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder in fermented milk by L. plantarum LP69 was 14 h, 3.0%, 35°C, 20 min, 14% and 0.70% for ACE inhibitory activity and 22 h, 3.0%, 40°C, 25 min, 16% and 0.60% for viable cell counts, respectively. The incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder had a significant influence on ACE inhibitory activity in fermented milk by Lactobacillus plantarum LP69, the results are beneficial for further screening of main factors by using fractional factorial designs.

  7. A super soliton connection

    International Nuclear Information System (INIS)

    Gurses, M.; Oguz, O.

    1985-07-01

    Integrable super non-linear classical partial differential equations are considered. A super s1(2,R) algebra valued connection 1-form is constructed. It is shown that curvature 2-form of this super connection vanishes by virtue of the integrable super equations of motion. A super extension of the AKNS scheme is presented and a class of super extension of the Lax hierarchy and super non-linear Schroedinger equation are found. O(N) extension and the Baecklund transformations of the above super equations are also considered. (author)

  8. Roller compaction: Effect of morphology and amorphous content of lactose powder on product quality.

    Science.gov (United States)

    Omar, Chalak S; Dhenge, Ranjit M; Osborne, James D; Althaus, Tim O; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

    2015-12-30

    The effect of morphology and amorphous content, of three types of lactose, on the properties of ribbon produced using roller compaction was investigated. The three types of lactose powders were; anhydrous SuperTab21AN, α-lactose monohydrate 200 M, and spray dried lactose SuperTab11SD. The morphology of the primary particles was identified using scanning electron microscopy (SEM) and the powder amorphous content was quantified using NIR technique. SEM images showed that 21AN and SD are agglomerated type of lactose whereas the 200 M is a non-agglomerated type. During ribbon production, an online thermal imaging technique was used to monitor the surface temperature of the ribbon. It was found that the morphology and the amorphous content of lactose powders have significant effects on the roller compaction behaviour and on ribbon properties. The agglomerated types of lactose produced ribbon with higher surface temperature and tensile strength, larger fragment size, lower porosity and lesser fines percentages than the non-agglomerated type of lactose. The lactose powder with the highest amorphous content showed to result in a better binding ability between the primary particles. This type of lactose produced ribbons with the highest temperature and tensile strength, and the lowest porosity and amount of fines in the product. It also produced ribbon with more smooth surfaces in comparison to the other two types of lactose. It was noticed that there is a relationship between the surface temperature of the ribbon during production and the tensile strength of the ribbon; the higher the temperature of the ribbon during production the higher the tensile strength of the ribbon. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Study on design of light-weight super-abrasive wheel

    Science.gov (United States)

    Nohara, K.; Yanagihara, K.; Ogawa, M.

    2018-01-01

    Fixed-abrasive tool, also called a grinding wheel, is produced by furnacing abrasive compound which contains abrasive grains and binding powder such as vitrified materials or resins. Fixed-abrasive tool is installed on spindle of grinding machine. And it is given 1,800-2,000 min-1 of spindle rotation for the usage. The centrifugal fracture of the compound of fixed- abrasive tool is one of the careful respects in designing. In recent years, however, super-abrasive wheel as a fixed-abrasive tool has been developed and applied widely. One of the most characteristic respects is that metal is applied for the body of grinding-wheel. The strength to hold abrasive grain and the rigidity of wheel become stronger than those of general grinding wheel, also the lifespan of fixed-abrasive tool becomes longer. The weight of fixed-abrasive tool, however, becomes heavier. Therefore, when the super-abrasive wheel is used, the power consumption of spindle motor becomes larger. It also becomes difficult for the grinding-wheel to respond to sudden acceleration or deceleration. Thus, in order to reduce power consumption in grinding and to obtain quicker frequency response of super-abrasive wheel, the new wheel design is proposed. The design accomplishes 46% weight reduction. Acceleration that is one second quicker than that of conventional grinding wheel is obtained.

  10. Some aspects of barreling in sintered plain carbon steel powder metallurgy preforms during cold upsetting

    Directory of Open Access Journals (Sweden)

    Sumesh Narayan

    2012-04-01

    Full Text Available The present research establishes a relationship of bulged diameter with densification and hydrostatic stress in forming of sintered iron (Fe powder metallurgy preforms cold upset under two different frictional conditions, namely, nil/no and graphite lubricant condition. Sintered plain carbon steel cylindrical preforms with carbon (C contents of 0, 0.35, 0.75 and 1.1% with constant initial theoretical density of 84% and aspect ratio of 0.4 and 0.6 were prepared using a suitable die-set assembly on a 1 MN capacity hydraulic press and sintered for 90 minutes at 1200 °C. Each sintered preform was cold upset under two different frictional constraints. It is seen that the degree of bulging reduces with reducing frictional constraints at the die contact surface. Further, it is found that the bulging ratio changed as a function of relative density and hydrostatic stress, respectively, according to the power law equations.

  11. Crystallization characteristics of ammonium uranyl carbonate (AUC) in ammonium carbonate solutions

    International Nuclear Information System (INIS)

    Kim, T.J.; Jeong, K.C.; Park, J.H.; Chang, I.S.; Choi, C.S.

    1994-01-01

    Ammonium carbonate solutions with an excessive amount of NH 3 were produced in a commercial AUC (ammonium uranyl carbonate) conversion plant. In this study the AUC crystals, precipitated with uranyl nitrate and ammonium carbonate solutions prepared in the laboratory, were characterized to determine the feasibility of recycling ammonium carbonate solution. The AUC crystals were easily agglomerated with the increasing concentration of CO 3 2- and mole ratio of NH 4 + /CO 3 2- in ammonium carbonate solution. Effects of a mixing system for the solution in the AUC crystallizer and the feed location of the solution onthe agglomeration of AUC crystals were also studied along with the effects of agglomerated AUC powders on UO 2 powders. Finally, the feasibility of manufacturing UO 2 fuel with a sintered pellet density of 10.52 g/cm 3 , using the AUC powders generated in this experiment, was demonstrated. (orig.)

  12. Characterization of Activated Carbons from Oil-Palm Shell by CO2 Activation with No Holding Carbonization Temperature

    Directory of Open Access Journals (Sweden)

    S. G. Herawan

    2013-01-01

    Full Text Available Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced.

  13. "Super-quenching" state protects Symbiodinium from thermal stress - Implications for coral bleaching.

    Science.gov (United States)

    Slavov, Chavdar; Schrameyer, Verena; Reus, Michael; Ralph, Peter J; Hill, Ross; Büchel, Claudia; Larkum, Anthony W D; Holzwarth, Alfred R

    2016-06-01

    The global rise in sea surface temperatures causes regular exposure of corals to high temperature and high light stress, leading to worldwide disastrous coral bleaching events (loss of symbiotic dinoflagellates (Symbiodinium) from reef-building corals). Our picosecond chlorophyll fluorescence experiments on cultured Symbiodinium clade C cells exposed to coral bleaching conditions uncovered the transformations of the alga's photosynthetic apparatus (PSA) that activate an extremely efficient non-photochemical "super-quenching" mechanism. The mechanism is associated with a transition from an initially heterogeneous photosystem II (PSII) pool to a homogeneous "spillover" pool, where nearly all excitation energy is transferred to photosystem I (PSI). There, the inherently higher stability of PSI and high quenching efficiency of P(700)(+) allow dumping of PSII excess excitation energy into heat, resulting in almost complete cessation of photosynthetic electron transport (PET). This potentially reversible "super-quenching" mechanism protects the PSA against destruction at the cost of a loss of photosynthetic activity. We suggest that the inhibition of PET and the consequent inhibition of organic carbon production (e.g. sugars) in the symbiotic Symbiodinium provide a trigger for the symbiont expulsion, i.e. bleaching. Copyright © 2016. Published by Elsevier B.V.

  14. Production of palm kernel shell-based activated carbon by direct physical activation for carbon dioxide adsorption.

    Science.gov (United States)

    Rashidi, Nor Adilla; Yusup, Suzana

    2018-05-09

    The feasibility of biomass-based activated carbons has received a huge attention due to their excellent characteristics such as inexpensiveness, good adsorption behaviour and potential to reduce a strong dependency towards non-renewable precursors. Therefore, in this research work, eco-friendly activated carbon from palm kernel shell that has been produced from one-stage physical activation by using the Box-Behnken design of Response Surface Methodology is highlighted. The effect of three input parameters-temperature, dwell time and gas flow rate-towards product yield and carbon dioxide (CO 2 ) uptake at room temperature and atmospheric pressure are studied. Model accuracy has been evaluated through the ANOVA analysis and lack-of-fit test. Accordingly, the optimum condition in synthesising the activated carbon with adequate CO 2 adsorption capacity of 2.13 mmol/g and product yield of 25.15 wt% is found at a temperature of 850 °C, holding time of 60 min and CO 2 flow rate of 450 cm 3 /min. The synthesised activated carbon has been characterised by diverse analytical instruments including thermogravimetric analyser, scanning electron microscope, as well as N 2 adsorption-desorption isotherm. The characterisation analysis indicates that the synthesised activated carbon has higher textural characteristics and porosity, together with better thermal stability and carbon content as compared to pristine palm kernel shell. Activated carbon production via one-step activation approach is economical since its carbon yield is within the industrial target, whereas CO 2 uptake is comparable to the synthesised activated carbon from conventional dual-stage activation, commercial activated carbon and other published data from literature.

  15. Effect of pineapple waste powder on probiotic growth, antioxidant and antimutagenic activities of yogurt.

    Science.gov (United States)

    Sah, B N P; Vasiljevic, T; McKechnie, S; Donkor, O N

    2016-03-01

    Although many fruit by-products are good sources of nutrients, little is known about their prebiotic potential. This research was aimed at establishing the prebiotic effect of pineapple wastes on probiotics including Lactobacillus (L.) acidophilus (ATCC® 4356™), L. casei (ATCC® 393™) and L. paracasei spp. paracasei (ATCC® BAA52™) and the subsequent release of antioxidant and antimutagenic peptides in yogurt during their growth. Oven- and freeze- dried peel and pomace were milled separately into powders and tested for prebiotic activities. The net probiotic growth (1.28-2.14 log cfu/g) in customized MRS broth containing the pineapple powders as a direct carbohydrate source was comparable to MRS broth containing glucose. The powders were also separately added to milk during the manufacturing of yogurt with or without probiotics. An increase (by 0.3-1.4 log cycle) in probiotic populations was observed in the yogurts as a consequence of pineapple powder supplementation. Crude water-soluble peptide extracts, prepared by high-speed centrifugation of the yogurts, displayed remarkable antioxidant activities assessed through in vitro assays, namely scavenging activity of 1,1-diphenyl-2-picrylhydrazyl radicals (IC50 = 0.37-0.19 mg/ml) and hydroxyl radicals (58.52-73.55 %). The peptide extracts also exhibited antimutagenic activities (18.60-32.72 %) as sodium azide inhibitor in the Salmonella mutagenicity test. Together, these results suggest that pineapple by-products exhibited prebiotic properties and could possibly be commercially applied in new functional food formulations.

  16. Effect of Red Pepper ( Powder or Red Pepper Pigment on the Performance and Egg Yolk Color of Laying Hens

    Directory of Open Access Journals (Sweden)

    Huaqiang Li

    2012-11-01

    Full Text Available Two experiments were conducted to study the effects of red pepper (Capsicum frutescens powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of hens with each battery consisting of a row of five cages of hens with two hens per cage (n = 3. In Exp. 2, 180, thirty-wk old, Hyline Brown laying hens, housed similarly to those in Exp. 1, were fed an unsupplemented basal diet as well as treatments in which the basal diet was supplemented with 0.8% red pepper powder processed in a laboratory blender to an average particle size of 300 μm, 0.8% red pepper powder processed as a super fine powder with a vibrational mill (44 μm and finally 0.8% red pepper powder processed as a super fine powder with a vibrational mill but mixed with 5% Na2CO3 either before or after grinding. A diet supplemented with 0.3 ppm carophyll red pigment was also included (n = 3. In both experiments, hens were fed the red pepper powder or pigment for 14 days. After feeding of the powder or pigment was terminated, all hens were fed the basal diet for eight more days to determine if the dietary treatments had any residual effects. In Exp. 1, there were no differences in egg-laying performance, feed consumption or feed conversion ratio due to inclusion of red pepper pigment in the diet. Average egg weight was higher (p0.05. However, compared with the control group, supplementation with all of the red pepper powder treatments increased egg weight (p<0.05. All the red pepper powder treatments also increased (p<0.05 the yolk color score compared with the control. The results of the present study suggest that both red pepper powder and pigment are effective feed additives for improving egg yolk color for laying hens.

  17. Anti-obesity activity of Yamabushitake (Hericium erinaceus) powder in ovariectomized mice, and its potentially active compounds.

    Science.gov (United States)

    Hiraki, Eri; Furuta, Shoko; Kuwahara, Rika; Takemoto, Naomichi; Nagata, Toshiro; Akasaka, Taiki; Shirouchi, Bungo; Sato, Masao; Ohnuki, Koichiro; Shimizu, Kuniyoshi

    2017-07-01

    Hericium erinaceus (H. erinaceus) improves the symptoms of menopause. In this study, using ovariectomized mice as a model of menopause, we investigated the anti-obesity effect of this mushroom in menopause. Mice fed diets containing H. erinaceus powder showed significant decreases in the amounts of fat tissue, plasma levels of total cholesterol, and leptin. To determine the mechanism, groups of mice were respectively fed a diet containing H. erinaceus powder, a diet containing ethanol extract of H. erinaceus, and a diet containing a residue of the extract. As a result, H. erinaceus powder was found to increase fecal lipid levels in excreted matter. Further in vitro investigation showed that ethanol extract inhibited the activity of lipase, and four lipase-inhibitory compounds were isolated from the extract: hericenone C, hericenone D, hericenone F, and hericenone G. In short, we suggest that H. erinaceus has an anti-obesity effect during menopause because it decreases the ability to absorb lipids.

  18. Batch sorption dynamics and equilibrium for the removal of lead ions from aqueous phase using activated carbon developed from coffee residue activated with zinc chloride.

    Science.gov (United States)

    Boudrahem, F; Aissani-Benissad, F; Aït-Amar, H

    2009-07-01

    Lignocellulosic materials are good precursors for the production of activated carbon. In this work, coffee residue has been used as raw material in the preparation of powder activated carbon by the method of chemical activation with zinc chloride for the sorption of Pb(II) from dilute aqueous solutions. The influence of impregnation ratio (ZnCl2/coffee residue) on the physical and chemical properties of the prepared carbons was studied in order to optimize this parameter. The optimum experimental condition for preparing predominantly microporous activated carbons with high pore surface area (890 m2/g) and micropore volume (0.772 cm3/g) is an impregnation ratio of 100%. The developed activated carbon shows substantial capability to sorb lead(II) ions from aqueous solutions and for relative impregnation ratios of 75 and 100%, the maximum uptake is practically the same. Thus, 75% represents the optimal impregnation ratio. Batch experiments were conducted to study the effects of the main parameters such as contact time, initial concentration of Pb(II), solution pH, ionic strength and temperature. The maximum uptake of lead(II) at 25 degrees C was about 63 mg/g of adsorbent at pH 5.8, initial Pb(II) concentration of 10 mg/L, agitation speed of 200 rpm and ionic strength of 0.005 M. The kinetic data were fitted to the models of pseudo-first order and pseudo-second order, and follow closely the pseudo-second order model. Equilibrium sorption isotherms of Pb(II) were analyzed by the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model gives a better fit than the others. Results from this study suggest that activated carbon produced from coffee residue is an effective adsorbent for the removal of lead from aqueous solutions and that ZnCl2 is a suitable activating agent for the preparation of high-porosity carbons.

  19. Electrochemical and anticorrosion performances of zinc-rich and polyaniline powder coatings

    International Nuclear Information System (INIS)

    Meroufel, A.; Deslouis, C.; Touzain, S.

    2008-01-01

    In this work, hydrochloride polyaniline (PANI-Cl) powder was incorporated as a conductive pigment into powder zinc-rich primer (ZRP) formulations in order to enhance the electronic conduction paths between zinc particles inside the coating and the steel substrate (i.e. percolation). Coatings were applied onto steel substrates and immersed in a 3% NaCl solution at ambient temperature. The protective properties and electrochemical behaviour of coatings were investigated by monitoring the free corrosion potential versus time and by using EIS. It was found that corrosion potential remains cathodic and constant for a long time up to 100 days of immersion. From EIS results, it was shown that the coatings exhibit larger impedance values than those observed with liquid or other zinc-rich powder formulations containing carbon black. From Raman spectroscopy results, it may be proposed that zinc particles in contact with PANI-Cl pigments were passivated. Other zinc particles remain still active which ensures the cathodic protection of the substrate. Moreover, coatings exhibit good barrier properties

  20. Effect of Red Pepper (Capsicum frutescens) Powder or Red Pepper Pigment on the Performance and Egg Yolk Color of Laying Hens.

    Science.gov (United States)

    Li, Huaqiang; Jin, Liji; Wu, Feifei; Thacker, Philip; Li, Xiaoyu; You, Jiansong; Wang, Xiaoyan; Liu, Sizhao; Li, Shuying; Xu, Yongping

    2012-11-01

    Two experiments were conducted to study the effects of red pepper (Capsicum frutescens) powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of hens with each battery consisting of a row of five cages of hens with two hens per cage (n = 3). In Exp. 2, 180, thirty-wk old, Hyline Brown laying hens, housed similarly to those in Exp. 1, were fed an unsupplemented basal diet as well as treatments in which the basal diet was supplemented with 0.8% red pepper powder processed in a laboratory blender to an average particle size of 300 μm, 0.8% red pepper powder processed as a super fine powder with a vibrational mill (44 μm) and finally 0.8% red pepper powder processed as a super fine powder with a vibrational mill but mixed with 5% Na2CO3 either before or after grinding. A diet supplemented with 0.3 ppm carophyll red pigment was also included (n = 3). In both experiments, hens were fed the red pepper powder or pigment for 14 days. After feeding of the powder or pigment was terminated, all hens were fed the basal diet for eight more days to determine if the dietary treatments had any residual effects. In Exp. 1, there were no differences in egg-laying performance, feed consumption or feed conversion ratio due to inclusion of red pepper pigment in the diet. Average egg weight was higher (pfeeding red pepper powder did not affect egg-laying performance, feed consumption or feed conversion ratio (p>0.05). However, compared with the control group, supplementation with all of the red pepper powder treatments increased egg weight (pfeed additives for improving egg yolk color for laying hens.

  1. Influence of limestone powder on the reaction kinetics and mechanical properties of sodium carbonate activated slag

    NARCIS (Netherlands)

    Yuan, B.; Yu, Q.; Brouwers, H.J.H.

    2016-01-01

    The effects of limestone powder (LP) on the performance of Portland cement based composites have been extensively studied, considering that LP not only acts as nuclei sites, but that it is also chemically involved in the hydration process, which improves the reaction degree at the early age. In high

  2. Increase of porosity by combining semi-carbonization and KOH activation of formaldehyde resins to prepare high surface area carbons for supercapacitor applications

    Science.gov (United States)

    Heimböckel, Ruben; Kraas, Sebastian; Hoffmann, Frank; Fröba, Michael

    2018-01-01

    A series of porous carbon samples were prepared by combining a semi-carbonization process of acidic polymerized phenol-formaldehyde resins and a following chemical activation with KOH used in different ratios to increase specific surface area, micropore content and pore sizes of the carbons which is favourable for supercapacitor applications. Samples were characterized by nitrogen physisorption, powder X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The results show that the amount of KOH, combined with the semi-carbonization step had a remarkable effect on the specific surface area (up to SBET: 3595 m2 g-1 and SDFT: 2551 m2 g-1), pore volume (0.60-2.62 cm3 g-1) and pore sizes (up to 3.5 nm). The carbons were tested as electrode materials for electrochemical double layer capacitors (EDLC) in a two electrode setup with tetraethylammonium tetrafluoroborate in acetonitrile as electrolyte. The prepared carbon material with the largest surface area, pore volume and pore sizes exhibits a high specific capacitance of 145.1 F g-1 at a current density of 1 A g-1. With a high specific energy of 31 W h kg-1 at a power density of 33028 W kg-1 and a short time relaxation constant of 0.29 s, the carbon showed high power capability as an EDLC electrode material.

  3. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  4. A Feasibility Experiment of a W-powder Target

    CERN Multimedia

    Charitonidis, N; Carreta, O; Densham, C; Davenne, T; Fabich, A; Loveridge, P; Rivkin, L

    2014-01-01

    The development of high‐power targets remains a key R&D activity for future facilities presently under study like the Neutrino Factory, Muon Collider or upgraded high‐ power super beams for long‐baseline neutrino experiments.  The choice of materials to sustain the beam power ranging up to MW levels is not trivial. Granular solid targets have been proposed and are being studied as a candidate for such high‐power target systems. In the recently commissioned HiRadMat facility at CERN, a feasibility  experiment of a tungsten powder target was performed. The experiment was designed to explore for first time the impact of a high‐power proton beam on a static W-powder target in a thimble configuration. The diagnostics of the experiment were based on remote high speed photography as well as on laser‐doppler vibration measurements of the target containers. Results from the experimental findings are presented ...

  5. An investigation of heat exchanger fouling in dust suspension cooling systems using graphite powder and carbon dioxide gas

    International Nuclear Information System (INIS)

    Garton, D.A.; Hawes, R.I.; Rose, P.W.

    1966-01-01

    Some experiments have been performed to study the fouling of heat exchanger surfaces where heat is being transferred from a heated fluid to a cooled surface. The fluid studied was a suspension of 4-5 microns mean diameter graphite powder in carbon dioxide gas at near atmospheric pressures. The solids loading range covered was from 5 to 30 lb. graphite/lb. carbon dioxide, and gas Reynolds numbers from 6000 to 16000. Temperature gradients across the cooler of from 20 to 120 deg. C were obtained. The heat transfer ratio is correlated to show the dependence upon the solids loading ratio of the suspension, the gas Reynolds number and the temperature gradient across the cooler. The results have demonstrated that stringent precautions are necessary to ensure complete dryness of the graphite powder and the loop flow surfaces before any quantitative fouling data can be obtained, as the presence of entrained moisture will accelerate the deposition of material on the cold walls of the heat exchanger and can result in plugging. The heat transfer coefficient showed no obvious dependency upon either the gas Reynolds number or the temperature gradient across the cooler over the range investigated. The measured heat transfer coefficient was considerably lower than that obtained when the heat is transferred from a hot wall to a cooler fluid. At a solids loading of 30 lb, graphite/lb. carbon dioxide, the heat transfer coefficient was only 50% of that for heat transfer from a heated wall. At solids loadings below 7 lb/lb., the heat transfer was less than that for a gas alone. (author)

  6. TiO2 Photocatalyst Nanoparticle Separation: Flocculation in Different Matrices and Use of Powdered Activated Carbon as a Precoat in Low-Cost Fabric Filtration

    Directory of Open Access Journals (Sweden)

    Carlos F. Liriano-Jorge

    2014-01-01

    Full Text Available Separation of photocatalyst nanoparticles is a problem impeding widespread application of photocatalytic oxidation. As sedimentation of photocatalyst particles is facilitated by their flocculation, the influence of common constituents of biologically pretreated wastewaters (NaCl, NaHCO3, and their combination with humic acid sodium salt on flocculation was tested by the pipet method. Results showed that the impact of these substances on TiO2 nanoparticle flocculation is rather complex and strongly affected by pH. When humic acid was present, TiO2 particles did not show efficient flocculation in the neutral and slightly basic pH range. As an alternative to photocatalyst separation by sedimentation, precoat vacuum filtration with powdered activated carbon (PAC over low-cost spunbond polypropylene fabrics was tested in the presence of two PAC types in aqueous NaCl and NaHCO3 solutions as well as in biologically treated greywater and in secondary municipal effluent. PAC concentrations of ≥2 g/L were required in order to achieve a retention of nearly 95% of the TiO2 nanoparticles on the fabric filter when TiO2 concentration was 1 g/L. Composition of the aqueous matrix and PAC type had a slight impact on precoat filtration. PAC precoat filtration represents a potential pretreatment for photocatalyst removal by micro- or ultrafiltration.

  7. Characteristics of activated carbon remove sulfur particles against smog.

    Science.gov (United States)

    Ge, Shengbo; Liu, Zhenling; Furuta, Yuzo; Peng, Wanxi

    2017-09-01

    Sulfur particles, which could cause diseases, were the main powder of smog. And activated carbon had the very adsorption characteristics. Therefore, five sulfur particles were adsorbed by activated carbon and were analyzed by FT-IR. The optimal adsorption time were 120 min of Na 2 SO 3 , 120 min of Na 2 S 2 O 8 , 120 min of Na 2 SO 4 , 120 min of Fe 2 (SO 4 ) 3 and 120 min of S. FT-IR spectra showed that activated carbon had the eight characteristic absorption of S-S stretch, H 2 O stretch, O-H stretch, -C-H stretch, conjugated C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 O stretch or CC stretch, CH 2 bend, C-O stretch and acetylenic C-H bend vibrations at 3850 cm -1 , 3740 cm -1 , 3430 cm -1 , 2920 cm -1 , 1630 cm -1 , 1390 cm -1 , 1110 cm -1 and 600 cm -1 , respectively. For Na 2 SO 3 , the peaks at 2920 cm -1 , 1630 cm -1 , 1390 cm -1 and 1110 cm -1 achieved the maximum at 20 min. For Na 2 S 2 O 8 , the peaks at 3850 cm -1 , 3740 cm -1 and 2920 cm -1 achieved the maximum at 60 min. The peaks at 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 40 min. For Na 2 SO 4 , the peaks at 3430 cm -1 , 2920 cm -1 , 1630 cm -1 , 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 60 min. For Fe 2 (SO 4 ) 3 , the peaks at 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 20 min. For S, the peaks at 1630 cm -1 , 1390 cm -1 and 600 cm -1 achieved the maximum at 120 min. It provided that activated carbon could remove sulfur particles from smog air to restrain many anaphylactic diseases.

  8. Super-Calogero-Moser-Sutherland systems and free super-oscillators: a mapping

    International Nuclear Information System (INIS)

    Ghosh, Pijush K.

    2001-01-01

    We show that the supersymmetric rational Calogero-Moser-Sutherland (CMS) model of A N+1 -type is equivalent to a set of free super-oscillators, through a similarity transformation. We prescribe methods to construct the complete eigenspectrum and the associated eigenfunctions, both in supersymmetry-preserving as well as supersymmetry-breaking phases, from the free super-oscillator basis. Further we show that a wide class of super-Hamiltonians realizing dynamical OSp(2 vertical bar 2) supersymmetry, which also includes all types of rational super-CMS as a small subset, are equivalent to free super-oscillators. We study BC N+1 -type super-CMS model in some detail to understand the subtleties involved in this method

  9. Super Riemann surfaces

    International Nuclear Information System (INIS)

    Rogers, Alice

    1990-01-01

    A super Riemann surface is a particular kind of (1,1)-dimensional complex analytic supermanifold. From the point of view of super-manifold theory, super Riemann surfaces are interesting because they furnish the simplest examples of what have become known as non-split supermanifolds, that is, supermanifolds where the odd and even parts are genuinely intertwined, as opposed to split supermanifolds which are essentially the exterior bundles of a vector bundle over a conventional manifold. However undoubtedly the main motivation for the study of super Riemann surfaces has been their relevance to the Polyakov quantisation of the spinning string. Some of the papers on super Riemann surfaces are reviewed. Although recent work has shown all super Riemann surfaces are algebraic, some areas of difficulty remain. (author)

  10. Rapid synthesis of graphitic carbon nitride powders by metathesis reaction between CaCN2 and C2Cl6

    International Nuclear Information System (INIS)

    Pang Linlin; Bi Jianqiang; Bai Yujun; Qi Yongxin; Zhu Huiling; Wang Chengguo; Wu Jiwei; Lu Chengwei

    2008-01-01

    Carbon nitride powders were rapidly synthesized at low temperature via the chemical metathesis reaction between CaCN 2 and C 2 Cl 6 . X-ray diffraction results confirm the formation of crystalline graphitic carbon nitride. Besides the dominant morphology of nanoparticles, flakes, nanorods, hollow and solid spheres can be observed by transmission electron microscopy. The absorption peaks of C-N, C=N and s-triazine rings, as well as the absence of C≡N peak in the infrared spectra, further verify the formation of graphite-like sp 2 -bonded structure with planar networks. Elemental analysis gives an atomic ratio of N/C around 0.3. X-ray photoelectron spectra exhibit the existence of chemical bonding between C and N

  11. Mechanical activation of ceramic powders and its influence on the quality of the refractory linings

    International Nuclear Information System (INIS)

    Ceganac, Z.; Acimovic, Z.; Andric, Lj.; Petrov, M.; Mihajlovic, S.

    2003-01-01

    In the paper we present results of the investigation of the influence of mechanical activation of ceramic powders-talc and alumina, on the quality of refractory linings for casting applications. It is shown that additional fine grinding of ceramic powders increases the quality of the refractory lining. Grinding and activation of the particles with various granulations contributes to the creation of the homogenous continuous layer of refractory lining on the sand moulds and cores, as well as on the evaporating polystyrene patterns for applications in the Lost foam casting process. Refractory linings obtained within the activation of particles procedure have better adherence to moulds, cores and evaporating patterns. (Original)

  12. BREEDING SUPER-EARTHS AND BIRTHING SUPER-PUFFS IN TRANSITIONAL DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu, E-mail: echiang@astro.berkeley.edu [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720-3411 (United States)

    2016-02-01

    The riddle posed by super-Earths (1–4R{sub ⊕}, 2–20M{sub ⊕}) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ∼0.1–1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4–10R{sub ⊕}, 2–6M{sub ⊕}). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ∼1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.

  13. BREEDING SUPER-EARTHS AND BIRTHING SUPER-PUFFS IN TRANSITIONAL DISKS

    International Nuclear Information System (INIS)

    Lee, Eve J.; Chiang, Eugene

    2016-01-01

    The riddle posed by super-Earths (1–4R ⊕ , 2–20M ⊕ ) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ∼0.1–1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4–10R ⊕ , 2–6M ⊕ ). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ∼1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions

  14. Dust generation in powders: Effect of particle size distribution

    Directory of Open Access Journals (Sweden)

    Chakravarty Somik

    2017-01-01

    Full Text Available This study explores the relationship between the bulk and grain-scale properties of powders and dust generation. A vortex shaker dustiness tester was used to evaluate 8 calcium carbonate test powders with median particle sizes ranging from 2μm to 136μm. Respirable aerosols released from the powder samples were characterised by their particle number and mass concentrations. All the powder samples were found to release respirable fractions of dust particles which end up decreasing with time. The variation of powder dustiness as a function of the particle size distribution was analysed for the powders, which were classified into three groups based on the fraction of particles within the respirable range. The trends we observe might be due to the interplay of several mechanisms like de-agglomeration and attrition and their relative importance.

  15. The Super Patalan Numbers

    OpenAIRE

    Richardson, Thomas M.

    2014-01-01

    We introduce the super Patalan numbers, a generalization of the super Catalan numbers in the sense of Gessel, and prove a number of properties analagous to those of the super Catalan numbers. The super Patalan numbers generalize the super Catalan numbers similarly to how the Patalan numbers generalize the Catalan numbers.

  16. Grassmann, super-Kac-Moody and super-derivation algebras

    International Nuclear Information System (INIS)

    Frappat, L.; Ragoucy, E.; Sorba, P.

    1989-05-01

    We study the cyclic cocycles of degree one on the Grassmann algebra and on the super-circle with N supersymmetries (i.e. the tensor product of the algebra of functions on the circle times a Grassmann algebra with N generators). They are related to central extensions of graded loop algebras (i.e. super-Kac-Moody algebras). The corresponding algebras of super-derivations have to be compatible with the cocycle characterizing the extension; we give a general method for determining these algebras and examine in particular the cases N = 1,2,3. We also discuss their relations with the Ademollo et al. algebras, and examine the possibility of defining new kinds of super-conformal algebras, which, for N > 1, generalize the N = 1 Ramond-Neveu-Schwarz algebra

  17. The Influence of Duration of Mechanical Activation of Titanium Powder on its Morphology, Microstructure, and Microhardness

    Science.gov (United States)

    Ditenberg, I. A.; Korchagin, M. A.; Pinzhin, Yu. P.; Melnikov, V. V.; Tyumentsev, A. N.; Grinyaev, K. V.; Smirnov, I. V.; Radishevskii, V. L.; Tsverova, A. S.; Sukhanov, I. I.

    2017-10-01

    Using the methods of X-ray diffraction analysis and scanning and transmission electron microscopy, an investigation of the influence of duration of mechanical activation on morphology and structure of titanium powder is performed. In the course of processing the following stages of material transformation are revealed: fragmentation of the initial powder, conglomeration, and ovalization of the conglomerates. It is found that when the duration of mechanical activation increases, the characteristic size of coherent scattering regions is significantly decreased, which is accompanied by an increase in the value of microdistortions and intensive fragmentation of the crystal lattice inside powder particles followed by the formation of highly defective nanostructured states. The transformation of microstructure is accompanied by a considerable increase in microhardness.

  18. Super Dielectric Materials.

    Science.gov (United States)

    Fromille, Samuel; Phillips, Jonathan

    2014-12-22

    Evidence is provided here that a class of materials with dielectric constants greater than 10⁵ at low frequency (dielectric materials (SDM), can be generated readily from common, inexpensive materials. Specifically it is demonstrated that high surface area alumina powders, loaded to the incipient wetness point with a solution of boric acid dissolved in water, have dielectric constants, near 0 Hz, greater than 4 × 10⁸ in all cases, a remarkable increase over the best dielectric constants previously measured for energy storage capabilities, ca. 1 × 10⁴. It is postulated that any porous, electrically insulating material (e.g., high surface area powders of silica, titania, etc. ), filled with a liquid containing a high concentration of ionic species will potentially be an SDM. Capacitors created with the first generated SDM dielectrics (alumina with boric acid solution), herein called New Paradigm Super (NPS) capacitors display typical electrostatic capacitive behavior, such as increasing capacitance with decreasing thickness, and can be cycled, but are limited to a maximum effective operating voltage of about 0.8 V. A simple theory is presented: Water containing relatively high concentrations of dissolved ions saturates all, or virtually all, the pores (average diameter 500 Å) of the alumina. In an applied field the positive ionic species migrate to the cathode end, and the negative ions to the anode end of each drop. This creates giant dipoles with high charge, hence leading to high dielectric constant behavior. At about 0.8 V, water begins to break down, creating enough ionic species to "short" the individual water droplets. Potentially NPS capacitor stacks can surpass "supercapacitors" in volumetric energy density.

  19. Lisosan G, a powder of grain, does not interfere with the drug metabolizing enzymes and has a protective role on carbon tetrachloride-induced hepatotoxicity.

    Science.gov (United States)

    Longo, Vincenzo; Chirulli, Vera; Gervasi, Pier Giovanni; Nencioni, Simona; Pellegrini, Michela

    2007-08-01

    Lisosan G is a powder of grain registered as an alimentary integrator. The treatment of rats for 4 days with 0.5 g Lisosan G/kg had no effect on various drug metabolizing enzymes. Experiments in vitro showed that Lisosan G had radical scavenger activity. A confirmation of the antioxidative property of Lisosan G was also confirmed when it was administered in vivo to carbon tetrachloride (CCl(4))-intoxicated rats. The toxicity caused by CCl(4)-treatment of rats was restored to the control levels when the rats were given Lisosan G for 4 days before CCl(4). Lisosan G thus does not interfere with drug metabolizing system but has antioxidant properties and protects against CCl(4)-induced hepatotoxicity.

  20. Ultrafine TaC powders prepared in a high frequency plasma

    International Nuclear Information System (INIS)

    Canteloup, J.; Mocellin, A.

    1976-01-01

    Ultrafine tantalum carbide powders were prepared under conditions allowing higher purities to be achieved than when plasma or chemical vapour deposition techniques are used. The process consists of dissociation-vaporisation of powders in a radio frequency argon plasma followed by quenching of the vapours and collection in an electrostatic precipitator. Physical and chemical properties are given. The presence of excess carbon appears to protect against oxidation and as a dispersing medium for the carbide powders. (U.K.)

  1. Fabrication And Properties Of Silver Based Multiwall Carbon Nanotube Composite Prepared By Spark Plasma Sintering Method

    Directory of Open Access Journals (Sweden)

    Lis M.

    2015-06-01

    Full Text Available The paper presents results of investigations of the obtained nanocomposite materials based on silver with addition of multiwall carbon nanotubes. The powder of carbon nanotubes content from 0.1 to 3 wt. % was produced by application of powder metallurgy methods, through mixing and high-energetic milling, and also chemical methods. Modification of carbon nanotubes included electroless deposition of silver particles on the carbon nanotube active surfaces and chemical reduction with strong reducing agent – sodium borohydride (NaBH4. The obtained powder mixtures were consolidated by SPS – Spark Plasma Sintering method. The formed composites were subjected to tests of relative density, electrical conductivity and electro-erosion properties. Detailed examinations of the structure with application of X-ray microanalysis, with consideration of carbon nanotubes distribution, were also carried out. The effect of manufacturing methods on properties of the obtained composites was observed.

  2. High-performance super capacitors based on activated anthracite with controlled porosity

    Science.gov (United States)

    Lee, Hyun-Chul; Byamba-Ochir, Narandalai; Shim, Wang-Geun; Balathanigaimani, M. S.; Moon, Hee

    2015-02-01

    Mongolian anthracite is chemically activated using potassium hydroxide as an activation agent to make activated carbon materials. Prior to the chemical activation, the chemical agent is introduced by two different methods as follows, (1) simple physical mixing, (2) impregnation. The physical properties such as specific surface area, pore volume, pore size distribution, and adsorption energy distribution are measured to assess them as carbon electrode materials for electric double-layer capacitors (EDLC). The surface functional groups and morphology are also characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses respectively. The electrochemical results for the activated carbon electrodes in 3 M sulfuric acid electrolyte solution indicate that the activated Mongolian anthracite has relatively large specific capacitances in the range of 120-238 F g-1 and very high electrochemical stability, as they keep more than 98% of initial capacitances until 1000 charge/discharge cycles.

  3. The relationship between the addition method of the Ni-activator and the sinterability for the Ni-doped W-powder compact

    International Nuclear Information System (INIS)

    Moon, I.H.; Kim, J.S.

    1984-01-01

    The relationship between the nickel size added to tungsten powder and the sinterability was investigated for the Ni-doped W-powder compact. The Ni-added W-powder compact with various particle size ratios of W to Ni were prepared by mechanical mixing as well as by salt solution and reduction method. In the latter method the size of reduced Ni-particle could be controlled by drying rate of salt solution. The smaller the size of nickel particles added to W was, the activatedly sintered W-powder compact has shown higher sinterability in the initial stage of sintering. The dependence of sinterability on the size of Ni-activator could be partly explained by some physical characteristics of Ni-activator at sintering temperature. (Auth.)

  4. Kinetics, Equilibrium, and Thermodynamic Studies on Adsorption of Methylene Blue by Carbonized Plant Leaf Powder

    Directory of Open Access Journals (Sweden)

    V. Gunasekar

    2013-01-01

    Full Text Available Carbon synthesized from plant leaf powder was employed for the adsorption of methylene blue from aqueous effluent. Effects of pH (2, 4, 6, 8, and 9, dye concentration (50, 100, 150, and 200 mg/dm3, adsorbent dosage (0.5, 1.0, 1.5, and 2.0 g/dm3, and temperature (303, 313, and 323 K were studied. The process followed pseudo-second-order kinetics. Equilibrium data was examined with Langmuir and Freundlich isotherm models and Langmuir model was found to be the best fitting model with high R2 and low chi2 values. Langmuir monolayer adsorption capacity of the adsorbent was found to be 61.22 mg/g. From the thermodynamic analysis, ΔH, ΔG, and ΔS values for the adsorption of MB onto the plant leaf carbon were found out. From the values of free energy change, the process was found out to be feasible process. From the magnitude of ΔH, the process was found to be endothermic physisorption.

  5. Super oxidation and solidification of organic solvents, polycyclic aromatic hydrocarbons and pesticides at an abandoned chemical factory site

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Kevin; Xu, Paul [Suntime Remediation Company, Changzhou, Jiangsu (China); Loo, Walter [Environment and Technology Services, 1323 Horizon Lane, Patterson, CA 95363 (United States)

    2013-07-01

    Large quantities of organic chemical such as VOCs, SVOCs and POPs were found in the soil of land at an abandoned Chemical Plant. Technology of super oxidation was applied to the soil for cleanup. Fenton process was utilized to treat soil contaminated heavily by BHC, benzene, chlorobenzene, dichlorobenzene, hexachlorobenzene, dichloroethane, dichloropropane, trichlorobenzene and dichloroether, etc. Super oxidation was coupled with method of stabilization for this case to enhance the remediation effect, which proved to be successful. Concentration of concerned pollutants was brought down below the national regulation level by approximately 8 folds. To make the treated soil strong and effective layer preventing pollutants breaking through, Iron powder was mixed in the soil, forming PBR (Permeable Barrier Reactor), to lower the risk to human health. The site after enhanced super oxidation above was totally safe to be developed into a residential community and/or commercial area. (authors)

  6. Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Tsai, M F

    2000-01-01

    Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution. Copyright 2000 John Wiley & Sons, Ltd.

  7. Comparison of different drying methods on the physical properties, bioactive compounds and antioxidant activity of raspberry powders.

    Science.gov (United States)

    Si, Xu; Chen, Qinqin; Bi, Jinfeng; Wu, Xinye; Yi, Jianyong; Zhou, Linyan; Li, Zhaolu

    2016-04-01

    Dehydration has been considered as one of the traditional but most effective techniques for perishable fruits. Raspberry powders obtained after dehydration can be added as ingredients into food formulations such as bakery and dairy products. In this study, raspberry powders obtained by hot air drying (HAD), infrared radiation drying (IRD), hot air and explosion puffing drying (HA-EPD), infrared radiation and microwave vacuum drying (IR-MVD) and freeze drying (FD) were compared on physical properties, bioactive compounds and antioxidant activity. Drying techniques affected the physical properties, bioactive compounds and antioxidant activity of raspberry powders greatly. FD led to significantly higher (P drying methods. However, thermal drying techniques, especially combined drying methods, were superior to FD in final total polyphenol content, total flavonoid content and antioxidant activity. The combined drying methods, especially IR-MVD, showed the highest total polyphenol content (123.22 g GAE kg(-1) dw) and total flavonoid content (0.30 g CAE kg(-1) dw). Additionally, IR-MVD performed better in antioxidant activity retention. Overall, combined drying methods, especially IR-MVD, were found to result in better quality of raspberry powders among the thermal drying techniques. IR-MVD could be recommended for use in the drying industry because of its advantages in time saving and nutrient retention. © 2015 Society of Chemical Industry.

  8. Liquid Phase Plasma Synthesis of Iron Oxide Nanoparticles on Nitrogen-Doped Activated Carbon Resulting in Nanocomposite for Supercapacitor Applications.

    Science.gov (United States)

    Lee, Heon; Lee, Won-June; Park, Young-Kwon; Ki, Seo Jin; Kim, Byung-Joo; Jung, Sang-Chul

    2018-03-25

    Iron oxide nanoparticles supported on nitrogen-doped activated carbon powder were synthesized using an innovative plasma-in-liquid method, called the liquid phase plasma (LPP) method. Nitrogen-doped carbon (NC) was prepared by a primary LPP reaction using an ammonium chloride reactant solution, and an iron oxide/NC composite (IONCC) was prepared by a secondary LPP reaction using an iron chloride reactant solution. The nitrogen component at 3.77 at. % formed uniformly over the activated carbon (AC) surface after a 1 h LPP reaction. Iron oxide nanoparticles, 40~100 nm in size, were impregnated homogeneously over the NC surface after the LPP reaction, and were identified as Fe₃O₄ by X-ray photoelectron spectroscopy and X-ray diffraction. NC and IONCCs exhibited pseudo-capacitive characteristics, and their specific capacitance and cycling stability were superior to those of bare AC. The nitrogen content on the NC surface increased the compatibility and charge transfer rate, and the composites containing iron oxide exhibited a lower equivalent series resistance.

  9. Adsorption onto activated carbons in environmental engineering: some trends in water and air treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Le Cloirec, P. [Ecole des Mines de Nantes, UMR CNRS 6144 GEPEA, 44 (France)

    2005-07-01

    Full text of publication follows: Adsorption is commonly used in environmental protection processes and particularly in water and air treatment systems. Organic pollutants in aqueous or gaseous phases are transferred and adsorbed onto porous materials. Activated carbon (powder, grains) treatment is usually carried out and filters are used to eliminate volatile organic compounds (VOC), odors or micropollutants. The main objectives of this paper are to present examples of classical or new activated carbon processes used in drinking water production, wastewater purification or in air treatment in terms of processes, performances and modeling. - Water treatment: Micropollutants such as pesticides, herbicides... are classically removed by activated carbon granular systems in drinking water treatment plants. In order to get a good water quality and to safe money, the breakthrough time has to be accurately determined. Models with mass balance and transfer equations are proposed. However, some difficulties are found especially for complex solutions to get good agreement between experimental data and calculated values. A statistical approach using neural networks is proposed to simulate breakthrough curves. Examples are presented and compared to deterministic models. In order to intensify processes, a combination of ultrafiltration and activated carbon fiber cloth (ACFC) is presented to remove the large spectra of particles and organic molecules present in water. Systems (UF/ACFC) for surface water and industrial colored wastewater are applied and performances are determined as a function of operating conditions. - Air treatment: Activated carbon grain filters are used to control VOC emissions. Due to an exothermic reaction, an increase of local temperature in the reactor is noted and some fire accidents have been reported. For safety technologies, this temperature has to be previously determined. A model is proposed to simulate the breakthrough curves and temperatures

  10. Adsorption onto activated carbons in environmental engineering: some trends in water and air treatment processes

    International Nuclear Information System (INIS)

    Le Cloirec, P.

    2005-01-01

    Full text of publication follows: Adsorption is commonly used in environmental protection processes and particularly in water and air treatment systems. Organic pollutants in aqueous or gaseous phases are transferred and adsorbed onto porous materials. Activated carbon (powder, grains) treatment is usually carried out and filters are used to eliminate volatile organic compounds (VOC), odors or micropollutants. The main objectives of this paper are to present examples of classical or new activated carbon processes used in drinking water production, wastewater purification or in air treatment in terms of processes, performances and modeling. - Water treatment: Micropollutants such as pesticides, herbicides... are classically removed by activated carbon granular systems in drinking water treatment plants. In order to get a good water quality and to safe money, the breakthrough time has to be accurately determined. Models with mass balance and transfer equations are proposed. However, some difficulties are found especially for complex solutions to get good agreement between experimental data and calculated values. A statistical approach using neural networks is proposed to simulate breakthrough curves. Examples are presented and compared to deterministic models. In order to intensify processes, a combination of ultrafiltration and activated carbon fiber cloth (ACFC) is presented to remove the large spectra of particles and organic molecules present in water. Systems (UF/ACFC) for surface water and industrial colored wastewater are applied and performances are determined as a function of operating conditions. - Air treatment: Activated carbon grain filters are used to control VOC emissions. Due to an exothermic reaction, an increase of local temperature in the reactor is noted and some fire accidents have been reported. For safety technologies, this temperature has to be previously determined. A model is proposed to simulate the breakthrough curves and temperatures

  11. Super Normal Vector for Human Activity Recognition with Depth Cameras.

    Science.gov (United States)

    Yang, Xiaodong; Tian, YingLi

    2017-05-01

    The advent of cost-effectiveness and easy-operation depth cameras has facilitated a variety of visual recognition tasks including human activity recognition. This paper presents a novel framework for recognizing human activities from video sequences captured by depth cameras. We extend the surface normal to polynormal by assembling local neighboring hypersurface normals from a depth sequence to jointly characterize local motion and shape information. We then propose a general scheme of super normal vector (SNV) to aggregate the low-level polynormals into a discriminative representation, which can be viewed as a simplified version of the Fisher kernel representation. In order to globally capture the spatial layout and temporal order, an adaptive spatio-temporal pyramid is introduced to subdivide a depth video into a set of space-time cells. In the extensive experiments, the proposed approach achieves superior performance to the state-of-the-art methods on the four public benchmark datasets, i.e., MSRAction3D, MSRDailyActivity3D, MSRGesture3D, and MSRActionPairs3D.

  12. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  13. Carbon aerogels

    International Nuclear Information System (INIS)

    Berthon-Fabry, S.; Achard, P.

    2003-06-01

    The carbon aerogel is a nano-porous material at open porosity, electrical conductor. The aerogels morphology is variable in function of the different synthesis parameters. This characteristic offers to the aerogels a better adaptability to many applications: electrodes (super condensers, fuel cells). The author presents the materials elaboration and their applications. It provides also the research programs: fundamental research, realization of super-condenser electrodes, fuel cells electrodes, gas storage materials and opaque materials for thermal insulation. (A.L.B.)

  14. Research and development of super light water reactors and super fast reactors in Japan

    International Nuclear Information System (INIS)

    Oka, Y.; Morooka, S.; Yamakawa, M.; Ishiwatari, Y.; Ikejiri, S.; Katsumura, Y.; Muroya, Y.; Terai, T.; Sasaki, K.; Mori, H.; Hamamoto, Y.; Okumura, K.; Kugo, T.; Nakatsuka, T.; Ezato, K.; Akasaka, N.; Hotta, A.

    2011-01-01

    Super Light Water Reactors (Super LWR) and Super Fast Reactors (Super FR) are the supercritical- pressure light water cooled reactors (SCWR) that are developed by the research group of University of Tokyo since 1989 and now jointly under development with the researchers of Waseda University, University of Tokyo and other organizations in Japan. The principle of the reactor concept development, the results of the past Super LWR and Super FR R&D as well as the R&D program of the Super FR second phase project are described. (author)

  15. The super W∞ symmetry of the Manin-Radul super KP hierarchy

    International Nuclear Information System (INIS)

    Das, A.; Sin, S.J.

    1991-11-01

    We show that the Manin-Radul super KP hierarchy is invariant under super W ∞ transformations. These transformations are characterized by time dependent flows which commute with the usual flows generated by the conserved quantities of the super KP hierarchy. (author). 16 refs

  16. Sludge Recycle of Wastewater Treatment Plant via its Application as Powdered Activated Carbon for Removal of Methyl Tertiary-Butyl Ether (MTBE from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    MR Zare

    2016-05-01

    Full Text Available Introduction: Nowadays, application of MTBE due to its physical and chemical characteristics including high solubility in water has been increased, resulting in its release into the water resources. On other hand, waste activated sludge derived from municipal wastewater treatment plant (MWTP contains high amount of carbon. Therefore, this study aimed to provide the activated carbon via sludge of MWTP as well as to evaluate its efficiency for MTBE removal. Methods: The effect of some parameters such as kind of activator, pH (2-10, contact time (0-240min, adsorbent dose (2-6g/L and initial concentration of MTBE (20-70mg/L was investigated on MTBE adsorption via activated carbon, after preparation of coal from wastewater sludge and activation of this coal via 3 molar solution of H2PO4,  and KOH as well as 5 molar solution of ZnCl2. MTBE concentration in solution was determined via Gas-Chromatography instrument. The obtained experimental data were modeled by adsorption model of Freundlich and Langmuir. Results: The maximum adsorbed MTBE per gram of activated carbon was obtained when the ZnCL2 was used as an activator; however, there was no statistically significant difference among different activators. In addition, maximum removal efficiency (about 50% was obtained in acidic pH of 4, 6g/L of activated carbon and 20mg/L of MTBE concentration. Results of adsorption isotherm showed that Freundlich adsorption model had a better compliance with the experimental data. Conclusion: Regarding the problems associated with sludge disposal of wastewater treatment plant, recycling of this sludge, as an adsorbent, can eliminate most of these problems. As a result, the economical features with respect to industrial scale application and the efficiency of this substance in removal of other pollutants are recommended to be investigated.

  17. Fabrication of nuclear fuel by powder injection moulding: Study of the binders systems and the de-binding of feedstock containing actinide powder

    International Nuclear Information System (INIS)

    Bricout, J.

    2012-01-01

    Powder Injection Moulding (PIM) is identified as an innovative process for the nuclear fuel fabrication. Technological breakthrough compared to the current process of powder metallurgy, the impact of actinide powder's specificities on the different steps of PIM is performed. Alumina powders simulating actinide powder have been implemented with a reference binders system. Thermal and rheological studies show the injectability and the de-binding of feedstocks with adequate solid loading (≥50 %vol), thanks to the de-agglomeration during the mixing step, which allow to obtain net shape fuel pellet. Specific surface area of powders, acting as a key role in behaviour's feedstocks, has been integrated in analysis models of viscosity prediction according to the shear rate. Also conducted studies on uranium oxide powder show that the selected binders systems, which have a compatible rheological behaviour with PIM process, impact the de-agglomeration of powder and final microstructure of the fuel pellet, consistent with the results obtained on alumina powders. Independent behaviour of binders and uranium oxide powder, showing no adverse chemical reaction against the PIM process, show a residual mass of carbon of about 150 ppm after sintering. Binders system using polystyrene, resistant to radiolysis phenomena and loadable more than 50 %(vol) of actinide powder, shows the promising potential of PIM process for the fuel fabrication. (author) [fr

  18. PREPARATION AND CHARACTERIZATION OF STRONTIUM FLUORIDE POWDERS ACTIVATED BY NEODYMIUM FLUORIDE

    Directory of Open Access Journals (Sweden)

    S. V. Kuznetsov

    2015-07-01

    Full Text Available Subject of Study. The paper deals with preparation processes of ultradisperse, homogeneous powder Sr1-хNdхF2+х (х= 0.003-0.2, with use of ammonium fluoride as the fluorinating agent taken over 114-120 % from stoichiometry. Method. Nitrate of strontium, neodymium nitrate hexahydrate, with the content equal to 99. 99 % of the basic substance and ammonium fluoride were used as the source of substances. Activated powders of strontium fluoride were obtained by the method of deposition from aqueous solutions by washing the precipitate with a solution of ammonium fluoride, taken over 114 - 120% from stoichiometry. The washed precipitate was centrifuged for 5-7 min, dried in the air at 30-350 C. Heat treatment of the dried precipitate was carried out in two stages: the first stage at the temperature of 200- 2500 C for 0.5-1 hour, the second one at 550- 6000 C for 2-3 hours. X-ray analysis of the synthesized samples was carried out on a Bruker D8 Advance diffractometer, radiation Cu K. The size and shape measuring of the particles of activated strontium fluoride was carried out by means of electron microscope Carl Zeiss NVision 40. The content of neodymium in activated powders of strontium fluoride was determined by the method of spectral emission analysis on the device LEA - S500. Chemical analysis for determination of ammonium ion (NH4+ content in the obtained samples was performed by the method of Kjeldahl. Calculations of lattice parameters, size of coherent scattering regions and the values of micro-deformations were carried out by TOPAS program. Main Results. Preparation processes of ultradisperse, homogeneous powder Sr1-хNdхF2+х (х= 0.003-0.2, with use of ammonium fluoride as the fluorinating agent taken over 114-120 % from stoichiometry, provides obtaining the firm solution Sr1-x-yNdx(NH4yF2+x-y of the cubic fluorite structure. It has been found out that the morphology and size of the resulting product depend on the quantity of

  19. The influence of mechanical activation on the morphological changes of Fe/BaTiO_3 powder

    International Nuclear Information System (INIS)

    Kosanović, D.; Obradović, N.; Pavlović, V.P.; Marković, S.; Maričić, A.; Rasić, G.; Vlahović, B.; Pavlović, V.B.; Ristić, M.M.

    2016-01-01

    Highlights: • Fe/BaTiO_3 ceramic was prepared using a solid-state reaction. • Powder mixture of 60% Fe and 40% BaTiO_3 was mechanically activated up to 240 min. • Microstructure was characterized using Powder XRD and SEM. • Thermal stability of the activated samples was investigated using DSC. • Raman spectrum changes with activation, along with atypical resonant scattering. - Abstract: Crystal structure and morphology of mechanically activated nanocrystalline Fe/BaTiO_3 was investigated using a combination of spectroscopic and microscopic methods. These show that mechanical activation led to the creation of new surfaces and the comminution of the initial powder particles. Prolonged milling resulted in formation of larger agglomerates of BaTiO_3 and bimodal particle size distribution, where BaTiO_3 particles were significantly larger than those of iron-containing phases. Milling times of 210 min and above lead to a significant decrease in temperature of the oxidation of iron in the sample, indicating abrupt change in reactivity. Raman spectroscopy analysis has revealed that activation had a pronounced influence on Fe/BaTiO_3 lattice, thereby affecting both the stability of the crystal structure and the phase transition phenomena.

  20. MECHANICAL PROPERTIES AND CORROSION PROTECTION OF CARBON STEEL COATED WITH AN EPOXY BASED POWDER COATING CONTAINING MONTMORILONITE FUNCTIONALIZED WITH SILANE

    OpenAIRE

    Paula Tibola Bertuoli; Veronica Perozzo Frizzo; Diego Piazza; Lisete Cristine Scienza; Ademir José Zattera

    2014-01-01

    In the present work the MMT-Na+ clay was functionalized with 3-aminopropyltriethoxysilane (γ-APS) and incorporated in a commercial formulation epoxy-based powder coating in a proportion of 8 wt% and applied on 1008 carbon steel panels by electrostatic spray. Adhesion, flexibility, impact and corrosion performance in salt spray chamber tests were performed to evaluate the coatings. The presence of clay did not affect the mechanical properties of the film, however greater subcutaneo...

  1. Effect of the both texture and electrical properties of activated carbon on the CO{sub 2} adsorption capacity

    Energy Technology Data Exchange (ETDEWEB)

    Djeridi, W. [Research Laboratory: Engineering Process and Industrial Systems, National school of Engineers of Gabes, University of Gabes, St Omar Ibn Elkhattab, 6029 Gabes (Tunisia); Chimistry laboratory of Provence, University Aix-Marseille I, II, III- CNRS, UMR 6264, Centre de Saint Jerome, 13397 Marseille (France); Ouederni, A. [Research Laboratory: Engineering Process and Industrial Systems, National school of Engineers of Gabes, University of Gabes, St Omar Ibn Elkhattab, 6029 Gabes (Tunisia); Mansour, N.Ben [National Nanotechnology Research Centre, KACST, Riyadh (Saudi Arabia); Llewellyn, P.L. [Chimistry laboratory of Provence, University Aix-Marseille I, II, III- CNRS, UMR 6264, Centre de Saint Jerome, 13397 Marseille (France); Alyamani, A. [National Nanotechnology Research Centre, KACST, Riyadh (Saudi Arabia); El Mir, L., E-mail: djeridiwahid@yahoo.fr [Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Gabes University, Faculty of Sciences in Gabes, Gabes (Tunisia); Al Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Sciences, Department of Physics, 11623 Riyadh (Saudi Arabia)

    2016-01-15

    Highlights: • A series of activated carbon pellet without binder was prepared by chemical activation. • Carbon dioxide storage isotherm at 30 °C and up to 25 bars was measured for the microporous carbon. • Adsorption enthalpies have been correlated with the carbon dioxide uptake. • Pyrolysis temperature effect on the electrical conductivity of the samples. • Impact of the both texture and electrical properties on CO{sub 2} adsorption capacity have been deducted - Abstract: A series of activated carbon pellets (ACP) based on olive stones were studied for CO{sub 2} storage application. The surface area, pore volume, and pore diameter were evaluated from the analysis of N{sub 2} adsorption isotherm data. The characterization of carbon materials was performed by scanning electron microscopy (SEM), the powder X-ray diffraction (PXRD) and transmission electron microscopy (TEM). The adsorption enthalpies were obtained by microcalorimetry. The effect of pyrolysis temperature on textural, electrical conductivity and gas adsorption capacities of the ACP were investigated by adsorbing CO{sub 2} at 303 K in the pressure range of 0–2.3 MPa. In fact the electrical conductivity is strongly affected by the microporosity of the samples and the size of the micropore. It increases when the pore size decreases which affect the CO{sub 2} adsorption. Also with increases temperature the free electrons concentration on the surface increases which affect the interaction of the adsorbed gas molecules.

  2. Nanocrystalline AL2 O2 powders produced by laser induced gas phase reactions

    International Nuclear Information System (INIS)

    Borsella, E.; Botti, S.; Martelli, S.; Zappa, G.; Giorgi, R.; Turt, S.

    1993-01-01

    Nanocrystalline Al 2 O 3 powders were successfully synthesized by a CO 2 laser-driven gas-phase reaction involving trimethylaluminium (Al(CH 3 ) 3 ) and nitrous-oxide (N 2 O). Ethylene (C 2 H 4 ) was added as gas sensitizer. The as-synthesized powder particles showed a considerable carbon contamination and an amorphous-like structure. After thermal treatment at 1200-1400 degrees C, the powder was transformed to hexagonal a-Al 2 O 3 with very low carbon contamination as confirmed by X-ray diffraction, X-ray photo-electron spectroscopy and chemical analysis. The calcinated powders resulted to be spherical single crystal nanoparticles with a mean size of 15-20 nm, as determined by X-ray diffraction, electron microscopy and B.E.T. specific surface measurements. The laser synthesized Al 2 O 3 particles are well suited dispersoids for intermetallic alloy technology

  3. Synthesis of crystalline Ce-activated garnet phosphor powders and technique to characterize their scintillation light yield

    Science.gov (United States)

    Gordienko, E.; Fedorov, A.; Radiuk, E.; Mechinsky, V.; Dosovitskiy, G.; Vashchenkova, E.; Kuznetsova, D.; Retivov, V.; Dosovitskiy, A.; Korjik, M.; Sandu, R.

    2018-04-01

    This work reports on a process of preparation of garnet phosphor powders and a technique for light yield evaluation of strongly light scattering samples. Powders of scintillation compounds could be used as individual materials or as samples for express tests of scintillation properties. However, estimation of their light yield (LY) is complicated by strong light scattering of this kind of materials. Ce3+-activated yttrium-aluminum and gallium-gadolinium-aluminum garnet phosphor powders, Y3Al5O12 (YAG:Ce) and Gd3Ga3Al2O12 (GGAG:Ce), were obtained using a modified coprecipitation technique. Ga tends to residue in mother liquor in ammonia media, but the modification allows to avoid the loss of components. We propose an approach for sample preparation and LY measurement setup with alpha particles excitation, allowing to decrease light scattering influence and to estimate a light yield of powder samples. This approach is used to evaluate the obtained powders.

  4. [Study on absorbing volatile oil with mesoporous carbon].

    Science.gov (United States)

    Yan, Hong-mei; Jia, Xiao-bin; Zhang, Zhen-hai; Sun, E; Yang Nan

    2014-11-01

    Clove oil and turmeric oil were absorbed by mesoporous carbon. The absorption ratio of mesoporous carbon to volatile oil was optimized with the eugenol yield and curcumol yield as criteria Curing powder was characterized by scanning electron microscopy (SEM) and differential scanning calorietry (DSC). The effects of mesoporous carbon on dissolution in vitro and thermal stability of active components were studied. They reached high adsorption rate when the absorption ratio of mesoporous carbon to volatile oil was 1:1. When volatile oil was absorbed, dissolution rate of active components had a little improvement and their thermal stability improved after volatile oil was absorbed by the loss rate decreasing more than 50%. Absorbing herbal volatile oil with mesoporous carbon deserves further studying.

  5. Carbon tetrachloride desorption from activated carbon

    International Nuclear Information System (INIS)

    Jonas, L.A.; Sansone, E.B.

    1981-01-01

    Carbon tetrachloride was desorbed from a granular activated carbon subsequent to its adsorption under various vapor exposure periods. The varied conditions of exposure resulted in a range of partially saturated carbon beds which, when followed by a constant flow rate for desorption, generated different forms of the desorbing concentration versus time curve. A method of analyzing the desorption curves is presented which permits extraction of the various desorbing rates from the different desorption and to relate this to the time required for such regeneration. The Wheeler desorption kinetic equation was used to calculate the pseudo first order desorption rate constant for the carbon. The desorption rate constant was found to increase monotonically with increasing saturation of the bed, permitting the calculation of the maximum desorption rate constant for the carbon at 100% saturation. The Retentivity Index of the carbon, defined as the dimensionless ratio of the adsorption to the desorption rate constant, was found to be 681

  6. Ceria modified activated carbon: an efficient arsenic removal adsorbent for drinking water purification

    Science.gov (United States)

    Sawana, Radha; Somasundar, Yogesh; Iyer, Venkatesh Shankar; Baruwati, Babita

    2017-06-01

    Ceria (CeO2) coated powdered activated carbon was synthesized by a single step chemical process and demonstrated to be a highly efficient adsorbent for the removal of both As(III) and As(V) from water without any pre-oxidation process. The formation of CeO2 on the surface of powdered activated carbon was confirmed by X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. The percentage of Ce in the adsorbent was confirmed to be 3.5 % by ICP-OES. The maximum removal capacity for As(III) and As(V) was found to be 10.3 and 12.2 mg/g, respectively. These values are comparable to most of the commercially available adsorbents. 80 % of the removal process was completed within 15 min of contact time in a batch process. More than 95 % removal of both As(III) and As(V) was achieved within an hour. The efficiency of removal was not affected by change in pH (5-9), salinity, hardness, organic (1-4 ppm of humic acid) and inorganic anions (sulphate, nitrate, chloride, bicarbonate and fluoride) excluding phosphate. Presence of 100 ppm phosphate reduced the removal significantly from 90 to 18 %. The equilibrium adsorption pattern of both As(III) and As(V) fitted well with the Freundlich model with R 2 values 0.99 and 0.97, respectively. The material shows reusability greater than three times in a batch process (arsenic concentration reduced below 10 ppb from 330 ppb) and a life of at least 100 L in a column study with 80 g material when tested under natural hard water (TDS 1000 ppm, pH 7.8, hardness 600 ppm as CaCO3) spiked with 330 ppb of arsenic.

  7. Textural and electronic characteristics of mechanochemically activated composites with nanosilica and activated carbon

    International Nuclear Information System (INIS)

    Gun’ko, V.M.; Zaulychnyy, Ya.V.; Ilkiv, B.I.; Zarko, V.I.; Nychiporuk, Yu.M.; Pakhlov, E.M.; Ptushinskii, Yu.G.; Leboda, R.; Skubiszewska-Zięba, J.

    2011-01-01

    Nanosilicas (A-50, A-300, A-500)/activated carbon (AC, S BET = 1520 m 2 /g) composites were prepared using short-term (5 min) mechanochemical activation (MCA) of powder mixtures in a microbreaker. Smaller silica nanoparticles of A-500 (average diameter d av = 5.5 nm) can more easily penetrate into broad mesopores and macropores of AC microparticles than larger nanoparticles of A-50 (d av = 52.4 nm) or A-300 (d av = 8.1 nm). After MCA of silica/AC, nanopores of non-broken AC nanoparticles remained accessible for adsorbed N 2 molecules. According to ultra-soft X-ray emission spectra (USXES), MCA of silica/AC caused formation of chemical bonds Si-O-C; however, Si-C and Si-Si bonds were practically not formed. A decrease in intensity of OK α band in respect to CK α band of silica/AC composites with diminishing sizes of silica nanoparticles is due to both changes in the surface structure of particles and penetration of a greater number of silica nanoparticles into broad pores of AC microparticles and restriction of penetration depth of exciting electron beam into the AC particles.

  8. Changes in Enzyme Activities Involved in Starch Synthesis and Hormone Concentrations in Superior and Inferior Spikelets and Their Association with Grain Filling of Super Rice

    Directory of Open Access Journals (Sweden)

    Jing FU

    2013-03-01

    Full Text Available The changes in activities of key enzymes involved in sucrose-to-starch conversion and concentrations of hormones in superior and inferior spikelets of super rice were investigated and their association with grain filling was analyzed. Four super rice cultivars, Liangyoupeijiu, IIyou 084, Huaidao 9 and Wujing 15, and two high-yielding and elite check cultivars, Shanyou 63 and Yangfujing 8, were used. The activities of sucrose synthase (SuSase, adenosine diphosphoglucose pyrophosphorylase (AGPase, starch synthase (StSase and starch branching enzyme (SBE, and the concentrations of zeatin + zeatin riboside (Z + ZR, indole-3-acetic acid (IAA and abscisic acid (ABA in superior and inferior spikelets were determined during the grain filling period and their relationships with grain filling rate were analyzed. Maximum grain filling rate, the time reaching the maximum grain-filling rate, mean grain filling rate and brown rice weight for superior spikelets showed a slight difference between the super and check rice cultivars, but were significantly lower in the super rice than in the check rice for inferior spikelets. Changes of enzyme activities and hormone concentrations in grains exhibited single peak curves during the grain filling period. The peak values and the mean activities of SuSase, AGPase, StSase and SBE were lower in inferior spikelets than in superior ones, as well as the peak values and the mean concentrations of Z + ZR and IAA. However, the peak value and the mean concentration of ABA were significantly higher in inferior spikelets than in superior ones and greater in the super rice than in the check rice. The grain filling rate was positively and significantly correlated with the activities of SuSase, AGPase and StSase and the concentrations of Z + ZR and IAA. The results suggested that the low activities of SuSase, AGPase and StSase and the low concentrations of Z + ZR and IAA might be important physiological reasons for the slow grain

  9. Composite carbon foam electrode

    Science.gov (United States)

    Mayer, Steven T.; Pekala, Richard W.; Kaschmitter, James L.

    1997-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivty and power to system energy.

  10. Nanostructured hydroxyapatite powders produced by a flame-based technique

    Energy Technology Data Exchange (ETDEWEB)

    Trommer, R.M., E-mail: rafael_trommer@yahoo.com.br [Ceramic Materials Laboratory, av. Osvaldo Aranha 99/705, 90035190, Porto Alegre, RS (Brazil); Santos, L.A. [Biomaterials Laboratory, av. Bento Goncalves 9500, Campus do Vale Setor IV Predio 74 Sala 123, 91501970, Porto Alegre, RS (Brazil); Bergmann, C.P. [Ceramic Materials Laboratory, av. Osvaldo Aranha 99/705, 90035190, Porto Alegre, RS (Brazil)

    2009-08-01

    In this work we reported the production of hydroxyapatite (HA) powder, one of the most studied calcium phosphates in the bioceramics field, using a cost-effective apparatus, composed by three major components: the atomization device, the pilot and main flames and finally the powder collector system. Calcium acetate and ammonium phosphate, diluted in ethanol and water, were used as salts in the precursor solution. The Ca/P molar ratio in the precursor solution was 1.65, equivalent to biological hydroxyapatite. After its production and collection, HA powder was calcined at 600 deg. C for 2 h. X-ray diffraction analysis pointed to the formation of crystalline hydroxyapatite powders. Carbonate was identified in the powders by Fourier-transform infrared (FTIR) spectroscopy. Scanning electronic microscopy (SEM) showed that the powders were composed of spherical primary particles and secondary aggregates, with the morphology unchanged after calcination. By transmission electronic microscopy (TEM), it was observed that the crystallite size of the primary particles was 24.8 {+-} 5.8 nm, for the calcined powder. The specific surface area was 15.03 {+-} 6.4 and 26.50 {+-} 7.6 m{sup 2}/g, for the as-synthetized and calcined powder respectively.

  11. Adsorption characteristics of activated carbon hollow fibers

    Directory of Open Access Journals (Sweden)

    B. V. Kaludjerović

    2009-01-01

    Full Text Available Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.

  12. Use of cork powder and granules for the adsorption of pollutants: a review.

    Science.gov (United States)

    Pintor, Ariana M A; Ferreira, Catarina I A; Pereira, Joana C; Correia, Patrícia; Silva, Susana P; Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2012-06-15

    Cork powder and granules are the major subproducts of the cork industry, one of the leading economic activities in Portugal and other Mediterranean countries. Many applications have been envisaged for this product, from cork stoppers passing through the incorporation in agglomerates and briquettes to the use as an adsorbent in the treatment of gaseous emissions, waters and wastewaters. This paper aims at reviewing the state of the art on the properties of cork and cork powder and their application in adsorption technologies. Cork biomass has been used on its original form as biosorbent for heavy metals and oils, and is also a precursor of activated carbons for the removal of emerging organic pollutants in water and VOCs in the gas phase. Through this literature review, different potential lines of research not yet explored can be more easily identified. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Reduction of 4-dim self dual super Yang-Mills onto super Riemann surfaces

    International Nuclear Information System (INIS)

    Mendoza, A.; Restuccia, A.; Martin, I.

    1990-05-01

    Recently self dual super Yang-Mills over a super Riemann surface was obtained as the zero set of a moment map on the space of superconnections to the dual of the super Lie algebra of gauge transformations. We present a new formulation of 4-dim Euclidean self dual super Yang-Mills in terms of constraints on the supercurvature. By dimensional reduction we obtain the same set of superconformal field equations which define self dual connections on a super Riemann surface. (author). 10 refs

  14. TOF powder diffractometer on a reactor source

    International Nuclear Information System (INIS)

    Bleif, H.J.; Wechsler, D.; Mezei, F.

    1999-01-01

    Complete text of publication follows. The performance of time-of-flight (TOF) methods on Long Pulse Spallation Sources can be studied at a reactor source. For this purpose a prototype TOF monochromator instrument will be installed at the KFKI reactor in Budapest. The initial setup will be a powder diffractometer with a resolution of δd/d down to 2 x 10 -3 at a wavelength of 1 A. The instrument uses choppers to produce neutron pulses of down to 10 μs FWHM. The optimal neutron source for a chopper instrument is a Long Pulse Spallation Source, but even on a continuous source simulations have shown that this instrument outperforms a conventional crystal monochromator powder diffractometer at high resolution. The main components of the TOF instrument are one double chopper defining the time resolution and two single choppers to select the wavelength range and to prevent frame overlap. For inelastic experiments a further chopper can be added in front of the sample. The neutron guide has a super-mirror coating and a curvature of 3500m. The total flight path is 20m and there are 24 single detectors in backscattering geometry. (author)

  15. Analysis of exergy efficiency of a super-critical compressed carbon dioxide energy-storage system based on the orthogonal method.

    Science.gov (United States)

    He, Qing; Hao, Yinping; Liu, Hui; Liu, Wenyi

    2018-01-01

    Super-critical carbon dioxide energy-storage (SC-CCES) technology is a new type of gas energy-storage technology. This paper used orthogonal method and variance analysis to make significant analysis on the factors which would affect the thermodynamics characteristics of the SC-CCES system and obtained the significant factors and interactions in the energy-storage process, the energy-release process and the whole energy-storage system. Results have shown that the interactions in the components have little influence on the energy-storage process, the energy-release process and the whole energy-storage process of the SC-CCES system, the significant factors are mainly on the characteristics of the system component itself, which will provide reference for the optimization of the thermal properties of the energy-storage system.

  16. Production and characterization of granular activated carbon from activated sludge

    Directory of Open Access Journals (Sweden)

    Z. Al-Qodah

    2009-03-01

    Full Text Available In this study, activated sludge was used as a precursor to prepare activated carbon using sulfuric acid as a chemical activation agent. The effect of preparation conditions on the produced activated carbon characteristics as an adsorbent was investigated. The results indicate that the produced activated carbon has a highly porous structure and a specific surface area of 580 m²/g. The FT-IR analysis depicts the presence of a variety of functional groups which explain its improved adsorption behavior against pesticides. The XRD analysis reveals that the produced activated carbon has low content of inorganic constituents compared with the precursor. The adsorption isotherm data were fitted to three adsorption isotherm models and found to closely fit the BET model with R² equal 0.948 at pH 3, indicating a multilayer of pesticide adsorption. The maximum loading capacity of the produced activated carbon was 110 mg pesticides/g adsorbent and was obtained at this pH value. This maximum loading was found experimentally to steeply decrease as the solution pH increases. The obtained results show that activated sludge is a promising low cost precursor for the production of activated carbon.

  17. Structural and adsorptive properties of activated carbons prepared by carbonization and activation of resins.

    Science.gov (United States)

    Leboda, R; Skubiszewska-Zieba, J; Tomaszewski, W; Gun'ko, V M

    2003-07-15

    Four activated carbons (S1-S4) possessing different structural characteristics were prepared by carbonization of commercial resins (used for ion exchange) and subsequent activation. Their textural parameters were determined on the basis of nitrogen adsorption-desorption at 77.4 K, analyzed by applying several local and overall adsorption isotherm equations. The nature of carbon surface functionalities was analyzed by FTIR spectroscopy. The GC and solid-phase extraction (SPE) techniques were applied to study the influence of the texture of carbonaceous materials on their adsorptive properties. The adsorption efficiency of synthesized carbons with respect to alkylhalides used as probe compounds in the GC measurements varied over a range from 28% (C(2)H(3)Cl(3)/S2) to 85% (CHBr(3)/S1) depending on the type of adsorbates and adsorbents. The concentrating efficiency of these carbons in SPE of explosive materials changed over a larger range from 12% (trinitroglycerin/S4) and 13% (trinitrotoluene/S2) up to 100% (octogen/S1). Active carbon prepared using Zerolite 225x8 as a precursor demonstrated better results than other carbons in two types of adsorption with average values of the efficiency of 75.4% for explosives and 60.8% for alkylhalides.

  18. Calculus super review

    CERN Document Server

    2012-01-01

    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Calculus I Super Review includes a review of functions, limits, basic derivatives, the definite integral, combinations, and permutations. Take the Super Review quizzes to see how much you've learned - and where you need more study. Makes an excellent study aid and textbook companion. Great for self-study!DETAILS- From cover to cover, each in-depth topic review is easy-to-follow and easy-to-grasp - Perfect when preparing for

  19. Adsorption by powders and porous solids principles, methodology and applications

    CERN Document Server

    Rouquerol, Jean; Llewellyn, Philip; Maurin, Guillaume; Sing, Kenneth SW

    2013-01-01

    The declared objective of this book is to provide an introductory review of the various theoretical and practical aspects of adsorption by powders and porous solids with particular reference to materials of technological importance. The primary aim is to meet the needs of students and non-specialists who are new to surface science or who wish to use the advanced techniques now available for the determination of surface area, pore size and surface characterization. In addition, a critical account is given of recent work on the adsorptive properties of activated carbons, oxides, clays and zeolit

  20. Effect of hydrophobicity of pharmaceuticals and personal care products for adsorption on activated carbon: Adsorption isotherms, kinetics and mechanism.

    Science.gov (United States)

    Kaur, Harkirat; Bansiwal, Amit; Hippargi, Girivyankatesh; Pophali, Girish R

    2017-09-11

    Adsorption of three pharmaceuticals and personal care products (PPCPs), namely caffeine, ibuprofen and triclosan on commercial powdered activated carbon was examined in aqueous medium. The contaminants were chosen based on their diverse log K ow (octanol-water partition coefficient) viz. - 0.07 for caffeine, 3.97 for ibuprofen and 4.76 for triclosan to examine the role of hydrophobicity on adsorption process. The adsorbent characterisation was achieved using BET surface area, SEM, pore size distribution studies and FTIR. Influence of mass of PAC, contact time, solution pH and initial concentration on adsorption capacity of PAC was studied. Adsorption isotherms and kinetics were applied to establish the mechanism of adsorption. The kinetics followed pseudo-second order with physisorption occurring through particle diffusion. The Freundlich model fitted best among the isotherm models. The adsorption capacity increased in the order CFN activated carbon.

  1. Multielemental analysis of Brazilian milk powder and bread samples by neutron activation

    International Nuclear Information System (INIS)

    Maihara, V.A.; Vasconcellos, M.B.A.

    1988-01-01

    The concentrations of Na, Cl, Mn, Br, Fe, Zn, Rb, Sb, Sc, Cr, Al and Mg were determined in some types of bread and in some brands of milk powder consumed in the city of Sao Paulo (SP - Brasil), by instrumental neutron activation analysis. Radiochemical separations were carried out by means of retention of 24 Na on hydrated antimony pentoxide (HAP) from a 8N HCl solution, after digestion of the organic matter. Thus the radioisotopes 64 Cu, 69m Zn and 140 La could be determined in the effluent solution. The detection limits of the trace elements analyzed in bread and milk powder samples were determined using the Currie and Girardi criterions. (author) 22 refs.; 2 figs.; 7 tabs

  2. Synthesis of calcium phosphate hydrogel from waste incineration fly ash and bone powder

    International Nuclear Information System (INIS)

    Fukui, Kunihiro; Arimitsu, Naoki; Kidoguchi, Satoshi; Yamamoto, Tetsuya; Yoshida, Hideto

    2009-01-01

    Waste incineration fly ash and bone powder could be successfully recycled into calcium phosphate hydrogel, a type of fast proton conductor. Various properties of the intermediate and calcium phosphate hydrogel from them were characterized and compared with that from calcium carbonate reagent. It was found that the intermediate from the incineration fly ash and calcium phosphate glass was more brittle than that from bone powder and calcium carbonate reagent. The electric conductivity of crystallized hydrogel obtained from all raw materials increases exponentially with temperature. However, the crystallized hydrogel from incineration fly ash has lower electric conductivity and lower crystallinity than that from bone powder and the reagent. Moreover, the difference in electric conductivity between these crystallized hydrogels decreases with temperature. Compared with using the reagent as a raw material, bone powder provides a 25% reduction in the usage of H 3 PO 4 to acquire the crystallized hydrogel which has the highest conductivity. These experimental results suggest that the incineration fly ash and bone powder are useful calcium sources for the synthesis of calcium phosphate hydrogel

  3. 3D Model Studies on the Effect of Bed and Powder Type Upon Radial Static Pressure and Powder Distribution in Metallurgical Shaft Furnaces

    Directory of Open Access Journals (Sweden)

    Panic B.

    2017-09-01

    Full Text Available The flow of gases in metallurgical shaft furnaces has a decisive influence on the course and process efficiency. Radial changes in porosity of the bed cause uneven flow of gas along the radius of the reactor, which sometimes is deliberate and intentional. However, holdup of solid particles in descending packed beds of metallurgical shaft furnaces can lead to unintentional changes in porosity of the bed along the radial reactor. Unintentional changes in porosity often disrupt the flow of gas causing poor performance of the furnace. Such disruptions of flow may occur in the blast furnace due to high level of powder content in gas caused by large amount of coal dust/powder insufflated as fuel substitute. The paper describes the model test results of radial distribution of static pressure and powder hold up within metallurgical reactor. The measurements were carried out with the use of 3D physical model of two-phase flow gas-powder in the moving (descending packed bed. Sinter or blast furnace pellets were used as packed bed while carbon powder or iron powder were used as the powder. Wide diversity within both static pressure distribution and powder distribution along the radius of the reactor were observed once the change in the type of powder occurred.

  4. PRODUCTION OF POROUS POWDER MATERIALS OF SPHERICAL POWDERS OF CORROSION-RESISTANT STEEL

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevskij

    2012-01-01

    Full Text Available Production of porous powder materials from spherical powders of corrosion-resistant steel 12Х18н10Т with formation at low pressures 120–140 mpa in the mold with the subsequent activated sintering became possible due to increase of duration of process of spattering and formation of condensate particles (Si–C or (Mo–Si on surface.

  5. Supermanifolds and super Riemann surfaces

    International Nuclear Information System (INIS)

    Rabin, J.M.

    1986-09-01

    The theory of super Riemann surfaces is rigorously developed using Rogers' theory of supermanifolds. The global structures of super Teichmueller space and super moduli space are determined. The super modular group is shown to be precisely the ordinary modular group. Super moduli space is shown to be the gauge-fixing slice for the fermionic string path integral

  6. Super-resolution binding activated localization microscopy through reversible change of DNA conformation.

    Science.gov (United States)

    Szczurek, Aleksander; Birk, Udo; Knecht, Hans; Dobrucki, Jurek; Mai, Sabine; Cremer, Christoph

    2018-01-01

    Methods of super-resolving light microscopy (SRM) have found an exponentially growing range of applications in cell biology, including nuclear structure analyses. Recent developments have proven that Single Molecule Localization Microscopy (SMLM), a type of SRM, is particularly useful for enhanced spatial analysis of the cell nucleus due to its highest resolving capability combined with very specific fluorescent labeling. In this commentary we offer a brief review of the latest methodological development in the field of SMLM of chromatin designated DNA Structure Fluctuation Assisted Binding Activated Localization Microscopy (abbreviated as fBALM) as well as its potential future applications in biology and medicine.

  7. Effect of agitation speed on adsorption of imidacloprid on activated carbon

    International Nuclear Information System (INIS)

    Zahoor, M.

    2011-01-01

    The adsorptive characteristics of imidacloprid on powdered activated carbon were described. The adsorption experiments were carried out as function of time, initial concentration and agitation speed. The equilibrium data fits well to Langmuir adsorption isotherm, while the kinetic data fits well to Pseudo second order kinetic model. The kinetic experiments were carried out at 200, 250, 300 and 350 rpm and it was found that the equilibrium time increases with increase in initial concentration and decreases with increase in agitation speed. This is due to the increased turbulence and as a consequence, the decrease boundary layer thickness around the adsorbent particles as a result of increasing the degree of mixing. At 300 rpm the adsorption capacity was maximum and beyond this there was no significant increase in adsorption capacity. Weber intra particle diffusion model was used to describe the adsorption mechanism. It was found that both the boundary layer and intra particle diffusion for both adsorbents played important role in the adsorption mechanisms of the adsorbate. The effects of temperature and pH on adsorption were also studied. It was found that the adsorption capacity of the adsorbent decreases with increase in temperature. There was no significant change in adsorption from pH 2 to 8, however at high pH a decrease in adsorption of imidacloprid on activated carbon was observed. (author)

  8. Predicting the occurrence of super-storms

    Directory of Open Access Journals (Sweden)

    N. Srivastava

    2005-11-01

    Full Text Available A comparative study of five super-storms (Dst<-300 nT of the current solar cycle after the launch of SoHO, to identify solar and interplanetary variables that influence the magnitude of resulting geomagnetic storms, is described. Amongst solar variables, the initial speed of a CME is considered the most reliable predictor of the strength of the associated geomagnetic storm because fast mass ejections are responsible for building up the ram pressure at the Earth's magnetosphere. However, although most of the super-storms studied were associated with high speed CMEs, the Dst index of the resulting geomagnetic storms varied between -300 to -472 nT. The most intense storm of 20 November 2003, (Dst ~ -472 nT had its source in a comparatively smaller active region and was associated with a relatively weaker, M-class flare while all other super-storms had their origins in large active regions and were associated with strong X-class flares. However, this superstorm did not show any associated extraordinary solar and interplanetary characteristics. The study also reveals the challenge in the reliable prediction of the magnitude of a geomagnetic storm from solar and interplanetary variables.

  9. Composite supercapacitor electrodes made of activated carbon ...

    Indian Academy of Sciences (India)

    carbon/PEDOT:PSS and activated carbon/doped PEDOT. T S SONIA, P A MINI, ... polymeric anodes for organic photovoltaics, light-emitting diodes (Pingree et al ... looked upon are carbon nanotubes (CNTs), graphene and activated carbon.

  10. Nanowire modified carbon fibers for enhanced electrical energy storage

    Science.gov (United States)

    Shuvo, Mohammad Arif Ishtiaque; (Bill) Tseng, Tzu-Liang; Ashiqur Rahaman Khan, Md.; Karim, Hasanul; Morton, Philip; Delfin, Diego; Lin, Yirong

    2013-09-01

    The study of electrochemical super-capacitors has become one of the most attractive topics in both academia and industry as energy storage devices because of their high power density, long life cycles, and high charge/discharge efficiency. Recently, there has been increasing interest in the development of multifunctional structural energy storage devices such as structural super-capacitors for applications in aerospace, automobiles, and portable electronics. These multifunctional structural super-capacitors provide structures combining energy storage and load bearing functionalities, leading to material systems with reduced volume and/or weight. Due to their superior materials properties, carbon fiber composites have been widely used in structural applications for aerospace and automotive industries. Besides, carbon fiber has good electrical conductivity which will provide lower equivalent series resistance; therefore, it can be an excellent candidate for structural energy storage applications. Hence, this paper is focused on performing a pilot study for using nanowire/carbon fiber hybrids as building materials for structural energy storage materials; aiming at enhancing the charge/discharge rate and energy density. This hybrid material combines the high specific surface area of carbon fiber and pseudo-capacitive effect of metal oxide nanowires, which were grown hydrothermally in an aligned fashion on carbon fibers. The aligned nanowire array could provide a higher specific surface area that leads to high electrode-electrolyte contact area thus fast ion diffusion rates. Scanning Electron Microscopy and X-Ray Diffraction measurements are used for the initial characterization of this nanowire/carbon fiber hybrid material system. Electrochemical testing is performed using a potentio-galvanostat. The results show that gold sputtered nanowire carbon fiber hybrid provides 65.9% higher energy density than bare carbon fiber cloth as super-capacitor.

  11. Deterministic phase measurements exhibiting super-sensitivity and super-resolution

    DEFF Research Database (Denmark)

    Schäfermeier, Clemens; Ježek, Miroslav; Madsen, Lars S.

    2018-01-01

    Phase super-sensitivity is obtained when the sensitivity in a phase measurement goes beyond the quantum shot noise limit, whereas super-resolution is obtained when the interference fringes in an interferometer are narrower than half the input wavelength. Here we show experimentally that these two...

  12. Biological activation of carbon filters.

    Science.gov (United States)

    Seredyńska-Sobecka, Bozena; Tomaszewska, Maria; Janus, Magdalena; Morawski, Antoni W

    2006-01-01

    To prepare biological activated carbon (BAC), raw surface water was circulated through granular activated carbon (GAC) beds. Biological activity of carbon filters was initiated after about 6 months of filter operation and was confirmed by two methods: measurement of the amount of biomass attached to the carbon and by the fluorescein diacetate (FDA) test. The effect of carbon pre-washing on WG-12 carbon properties was also studied. For this purpose, the nitrogen adsorption isotherms at 77K and Fourier transform-infrared (FT-IR) spectra analyses were performed. Moreover, iodine number, decolorizing power and adsorption properties of carbon in relation to phenol were studied. Analysis of the results revealed that after WG-12 carbon pre-washing its BET surface increased a little, the pH value of the carbon water extract decreased from 11.0 to 9.4, decolorizing power remained at the same level, and the iodine number and phenol adsorption rate increased. In preliminary studies of the ozonation-biofiltration process, a model phenol solution with concentration of approximately 10mg/l was applied. During the ozonation process a dose of 1.64 mg O(3)/mg TOC (total organic carbon) was employed and the contact time was 5 min. Four empty bed contact times (EBCTs) in the range of 2.4-24.0 min were used in the biofiltration experiment. The effectiveness of purification was measured by the following parameters: chemical oxygen demand (COD(Mn)), TOC, phenol concentration and UV(254)-absorbance. The parameters were found to decrease with EBCT.

  13. Synthesis of carbon nanotubes and nanotube forests on copper catalyst

    International Nuclear Information System (INIS)

    Kruszka, Bartosz; Terzyk, Artur P; Wiśniewski, Marek; Gauden, Piotr A; Szybowicz, Mirosław

    2014-01-01

    The growth of carbon nanotubes on bulk copper is studied. We show for the first time, that super growth chemical vapor deposition method can be successfully applied for preparation of nanotubes on copper catalyst, and the presence of hydrogen is necessary. Next, different methods of copper surface activation are studied, to improve catalyst efficiency. Among them, applied for the first time for copper catalyst in nanotubes synthesis, sulfuric acid activation is the most promising. Among tested samples the surface modified for 10 min is the most active, causing the growth of vertically aligned carbon nanotube forests. Obtained results have potential importance in application of nanotubes and copper in electronic chips and nanodevices. (paper)

  14. Freeze drying vs microwave drying–methods for synthesis of sinteractive thoria powders

    Energy Technology Data Exchange (ETDEWEB)

    Annie, D.; Chandramouli, V. [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 602103 (India); Anthonysamy, S., E-mail: sas@igcar.gov.in [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 602103 (India); Ghosh, Chanchal; Divakar, R. [Materials Synthesis and Structural Characterization Division, Materials and Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 602103 (India)

    2017-02-15

    Thoria powders were synthesized by oxalate precipitation from an aqueous solution of the nitrate. The filtered precipitates were freeze dried or microwave dried before being calcined at 1073 K. The thoria powders obtained were characterized for crystallite size, specific surface area, bulk density, particle size distribution and residual carbon. Microstructure of the product was studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Sinterability of the synthesized powders was studied by measuring the density of the sintered compacts. Powders that can be consolidated and sintered to densities ∼96% theoretical density (TD) at 1773 K were obtained.

  15. Effects of Lignosulfonate Structure on the Surface Activity and Wettability to a Hydrophobic Powder

    Directory of Open Access Journals (Sweden)

    Yuanyuan Ge

    2014-10-01

    Full Text Available The wettability of a solid material is very important in many applications, such as food, agrochemical formulations, and cosmetics. Wettability can be improved by adding surface active agents, especially biocompatible surfactants derived from biomass. In this work, the surface activity (ability to lower the surface tension of an aqueous solution and wettability toward a hydrophobic powder by a series of sodium lignosulfonates (NaLS synthesized with different degree of sulfonation (QS and weight-average molecular weights (Mw were investigated by measuring the surface tension and contact angle. The results demonstrated NaLS with a larger Mw or lower QS had higher surface activity. Conversely, the wettability of the NaLS aqueous solution toward difenoconazole powder showed a reverse trend, i.e., NaLS with a smaller Mw or higher Qs improved the wettability to difenoconazole. The surface activity and wettability was controlled by the varying densities of the NaLS molecules at the water to air interface or the solid/liquid interface, which was dependent on the molecular structure of NaLS.

  16. Desensitizing nano powders to electrostatic discharge ignition

    International Nuclear Information System (INIS)

    Steelman, Ryan; Daniels, Michael A.

    2015-01-01

    Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

  17. High surface area mesoporous activated carbon-alginate beads for efficient removal of methylene blue.

    Science.gov (United States)

    Nasrullah, Asma; Bhat, A H; Naeem, Abdul; Isa, Mohamed Hasnain; Danish, Mohammed

    2018-02-01

    High surface area mesoporous activated carbon-alginate (AC-alginate) beads were successfully synthesized by entrapping activated carbon powder derived from Mangosteen fruit peel into calcium-alginate beads for methylene blue (MB) removal from aqueous solution. The structure and surface characteristics of AC-alginate beads were analyzed using Fourier transform infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM) and surface area analysis (S BET ), while thermal properties were tested using thermogravimetric analysis (TGA). The effect of AC-alginate dose, pH of solution, contact time, initial concentration of MB solution and temperature on MB removal was elucidated. The results showed that the maximum adsorption capacity of 230mg/g was achieved for 100mg/L of MB solution at pH 9.5 and temperature 25°C. Furthermore, the adsorption of MB on AC-alginate beads followed well pseudo-second order equation and equilibrium adsorption data were better fitted by the Freundlich isotherm model. The findings reveal the feasibility of AC-alginate beads composite to be used as a potential and low cost adsorbent for removal of cationic dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Effect of Heat treatment on Hardness and Corrosion Resistance of Super Cast Iron

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Roun; Kim, Young Sik [Andong National University, Andong (Korea, Republic of)

    2014-07-15

    In fossil-fuel-fired power plants, a variety of pollutants are produced from the combustion of conventional fuels such as coal, oil and gas. Major component of such pollution are ash and corrosive chemicals, which also destroy pumps and piping; by causing erosion/corrosion, pitting, and wear. In order to over come such damage, materials with high hardness and high corrosion resistance are needed. In this work, we melted super-cast-iron with excellent corrosion resistance and high hardness. To elucidate the effect of heat treatment, microstructural analysis, hardness measurement, and corrosion tests were performed. Test results revealed that the super-cast-iron had several tens better corrosion resistance than 316 L stainless steel, and it also had a high surface hardness (> HRC45). High hardness, in spite of its low carbon content (0.74%C), could resulted from a hardening heat treatment to precipitate sufficient Cr{sub 7}C{sub 3} and Cr{sub 2}3C{sub 6}. Also, it was concluded that the excellent corrosion resistance of the super-cast-iron was due to the increase of the relative chromium content by minimizing the carbon content, and by the enhancement of passive film by the addition of Cr, Mo, Cu, and W.

  19. Nitrogen removal from coal gasification wastewater by activated carbon technologies combined with short-cut nitrogen removal process.

    Science.gov (United States)

    Zhao, Qian; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Jia, Shengyong; Fang, Fang

    2014-11-01

    A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal (GAC-PACT-SBNR) was developed to enhance total nitrogen (TN) removal for anaerobically treated coal gasification wastewater with less need for external carbon resources. The TN removal efficiency in SBNR was significantly improved by introducing the effluent from the GAC process into SBNR during the anoxic stage, with removal percentage increasing from 43.8%-49.6% to 68.8%-75.8%. However, the TN removal rate decreased with the progressive deterioration of GAC adsorption. After adding activated sludge to the GAC compartment, the granular carbon had a longer service-life and the demand for external carbon resources became lower. Eventually, the TN removal rate in SBNR was almost constant at approx. 43.3%, as compared to approx. 20.0% before seeding with sludge. In addition, the production of some alkalinity during the denitrification resulted in a net savings in alkalinity requirements for the nitrification reaction and refractory chemical oxygen demand (COD) degradation by autotrophic bacteria in SBNR under oxic conditions. PACT showed excellent resilience to increasing organic loadings. The microbial community analysis revealed that the PACT had a greater variety of bacterial taxons and the dominant species associated with the three compartments were in good agreement with the removal of typical pollutants. The study demonstrated that pre-adsorption by the GAC-sludge process could be a technically and economically feasible method to enhance TN removal in coal gasification wastewater (CGW). Copyright © 2014. Published by Elsevier B.V.

  20. Adsorption of selected pharmaceuticals and an endocrine disrupting compound by granular activated carbon. 2. Model prediction

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Z.; Peldszus, S.; Huck, P.M. [University of Waterloo, Waterloo, ON (Canada). NSERC Chair in Water Treatment

    2009-03-01

    The adsorption of two representative pharmaceutically active compounds (PhACs) naproxen and carbamazepine and one endocrine disrupting compound (EDC) nonylphenol was studied in pilot-scale granular activated carbon (GAC) adsorbers using post-sedimentation (PS) water from a full-scale drinking water treatment plant. The GAC adsorbents were coal-based Calgon Filtrasorb 400 and coconut shell-based PICA CTIF TE. Acidic naproxen broke through fastest while nonylphenol was removed best, which was consistent with the degree to which fouling affected compound removals. Model predictions and experimental data were generally in good agreement for all three compounds, which demonstrated the effectiveness and robustness of the pore and surface diffusion model (PSDM) used in combination with the time-variable parameter approach for predicting removals at environmentally relevant concentrations (i.e., ng/L range). Sensitivity analyses suggested that accurate determination of film diffusion coefficients was critical for predicting breakthrough for naproxen and carbamazepine, in particular when high removals are targeted. Model simulations demonstrated that GAC carbon usage rates (CURs) for naproxen were substantially influenced by the empty bed contact time (EBCT) at the investigated conditions. Model-based comparisons between GAC CURs and minimum CURs for powdered activated carbon (PAC) applications suggested that PAC would be most appropriate for achieving 90% removal of naproxen, whereas GAC would be more suitable for nonylphenol. 25 refs., 4 figs., 1 tab.

  1. Fabrication of carbonate apatite block based on internal dissolution-precipitation reaction of dicalcium phosphate and calcium carbonate.

    Science.gov (United States)

    Daitou, Fumikazu; Maruta, Michito; Kawachi, Giichiro; Tsuru, Kanji; Matsuya, Shigeki; Terada, Yoshihiro; Ishikawa, Kunio

    2010-05-01

    In this study, we investigated a novel method for fabrication of carbonate apatite block without ionic movement between precursor and solution by using precursor that includes all constituent ions of carbonate apatite. A powder mixture prepared from dicalcium phosphate anhydrous and calcite at appropriate Ca/P ratios (1.5, 1.67, and 1.8) was used as starting material. For preparation of specimens, the slurry made from the powder mixture and distilled water was packed in a split stainless steel mold and heat - treated, ranging from 60 degrees C to 100 degrees C up to 48 hours at 100% humidity. It appeared that carbonate apatite could be obtained above 70 degrees C and monophasic carbonate apatite could be obtained from the powder mixture at Ca/P ratio of 1.67. Carbonate content of the specimen was about 5-7%. Diametral tensile strength of the carbonate apatite blocks slightly decreased with increasing treatment temperature. The decrease in diametral tensile strength is thought to be related to the crystal size of the carbonate apatite formed.

  2. Activated carbon for incinerator uses

    International Nuclear Information System (INIS)

    Che Seman Mahmood; Norhayati Alias; Mohd Puad Abu

    2002-01-01

    This paper reports the development of the activated carbon from palm oil kernel shell for use as absorbent and converter for incinerator gas. The procedure is developed in order to prepare the material in bulk quantity and be used in the incinerator. The effect of the use of activating chemicals, physical activation and the preparation parameter to the quality of the carbon products will be discussed. (Author)

  3. Analysis of exergy efficiency of a super-critical compressed carbon dioxide energy-storage system based on the orthogonal method

    Science.gov (United States)

    He, Qing; Liu, Hui; Liu, Wenyi

    2018-01-01

    Super-critical carbon dioxide energy-storage (SC-CCES) technology is a new type of gas energy-storage technology. This paper used orthogonal method and variance analysis to make significant analysis on the factors which would affect the thermodynamics characteristics of the SC-CCES system and obtained the significant factors and interactions in the energy-storage process, the energy-release process and the whole energy-storage system. Results have shown that the interactions in the components have little influence on the energy-storage process, the energy-release process and the whole energy-storage process of the SC-CCES system, the significant factors are mainly on the characteristics of the system component itself, which will provide reference for the optimization of the thermal properties of the energy-storage system. PMID:29634742

  4. SHMUTZ & PROTON-DIAMANT H + Irradiated/Written-Hyper/Super-conductivity(HC/SC) Precognizance/Early Experiments Connections: Wet-Graphite Room-Tc & Actualized MgB2 High-Tc: Connection to Mechanical Bulk-Moduli/Hardness: Diamond Hydrocarbon-Filaments, Disorder, Nano-Powders:C,Bi,TiB2,TiC

    Science.gov (United States)

    Wunderman, Irwin; Siegel, Edward Carl-Ludwig; Lewis, Thomas; Young, Frederic; Smith, Adolph; Dresschhoff-Zeller, Gieselle

    2013-03-01

    SHMUTZ: ``wet-graphite''Scheike-....[Adv.Mtls.(7/16/12)]hyper/super-SCHMUTZ-conductor(S!!!) = ``wet''(?)-``graphite''(?) = ``graphene''(?) = water(?) = hydrogen(?) =ultra-heavy proton-bands(???) = ...(???) claimed room/high-Tc/high-Jc superconductOR ``p''-``wave''/ BAND(!!!) superconductIVITY and actualized/ instantiated MgB2 high-Tc superconductors and their BCS- superconductivity: Tc Siegel[ICMAO(77);JMMM 7,190(78)] connection to SiegelJ.Nonxline-Sol.40,453(80)] disorder/amorphous-superconductivity in nano-powders mechanical bulk/shear(?)-moduli/hardness: proton-irradiated diamond, powders TiB2, TiC,{Siegel[Semis. & Insuls.5:39,47, 62 (79)])-...``VS''/concommitance with Siegel[Phys.Stat.Sol.(a)11,45(72)]-Dempsey [Phil.Mag. 8,86,285(63)]-Overhauser-(Little!!!)-Seitz-Smith-Zeller-Dreschoff-Antonoff-Young-...proton-``irradiated''/ implanted/ thermalized-in-(optimal: BOTH heat-capacity/heat-sink & insulator/maximal dielectric-constant) diamond: ``VS'' ``hambergite-borate-mineral transformable to Overhauser optimal-high-Tc-LiBD2 in Overhauser-(NW-periodic-table)-Land: CO2/CH4-ETERNAL-sequestration by-product: WATER!!!: physics lessons from

  5. Compaction of LiBH4-LiAlH4 nanoconfined in activated carbon nanofibers: Dehydrogenation kinetics, reversibility, and mechanical stability during cycling

    DEFF Research Database (Denmark)

    Plerdsranoy, Praohatsorn; Javadian-Deylami, Seyd Payam; Jensen, Nicholai Daugaard

    2017-01-01

    To enhance volumetric hydrogen capacity for on-board fuel cells, compaction of LiAlH4-LiBH4 nanoconfined in activated carbon nanofibers (ACNF) is for the first time proposed. Loose powders of milled and nanoconfined LiAlH4-LiBH4 samples are compacted under 976 MPa to obtain the pellet samples...... with thickness and diameter of ∼1.20–1.30 and 8.0 mm, respectively. Dehydrogenation temperature of milled LiAlH4-LiBH4 increases from 415 to 434 °C due to compaction, while those of both compacted and loose powder samples of nanoconfined LiAlH4-LiBH4 are lower at comparable temperature of 330–335 °C. Hydrogen...

  6. Blue to Yellow Photoluminescence Emission and Photocatalytic Activity of Nitrogen Doping in TiO2 Powders

    Directory of Open Access Journals (Sweden)

    Gabriela Byzynski

    2015-01-01

    Full Text Available The defects caused by doping are important for understanding the increased photocatalytic activities of TiO2:N in organic reactions and in the evaluation of OH radical production after doping. TiO2:N was therefore synthesized using a modified polymeric method and N doping was performed by calcination with urea. The resulting powders were characterized using field emission scanning electron microscopy, X-ray diffraction, diffuse reflectance spectroscopy, Raman spectroscopy, Fourier transformation infrared spectroscopy, and photoluminescence emission spectroscopy (PL. N doping did not alter the morphology of the nanoparticles, and the anatase phase predominated, with the retention of the rutile phase. The band gap values, superficial areas, and crystallite sizes of the powders decreased after doping. The PL results showed an additional energy level in the TiO2:N band gap structure as a result of TiO2 lattice defects caused by doping. At low N contents, the powders showed continuous emissions from the blue region to the yellow region and a high N content shifted the PL emissions to the red region. These results suggest that the use of these powders could increase the efficiencies of solar cells and water-splitting processes. The photocatalytic activity of the powders under UVC illumination was confirmed for different organic dye molecules. The OH radical production did not change extensively after doping, as shown by experiments with terephthalic acid, and higher photocatalytic efficiencies in Rhodamine-B degradation under UVC illumination were achieved using the doped samples.

  7. High-yield Synthesis of Multiwalled Carbon Nanotube by Mechanothermal Method

    Directory of Open Access Journals (Sweden)

    Manafi SA

    2009-01-01

    Full Text Available Abstract This study reports on the mechanothermal synthesis of multiwalled carbon nanotube (MWCNTs from elemental graphite powder. Initially, high ultra-active graphite powder can be obtained by mechanical milling under argon atmosphere. Finally, the mechanical activation product is heat-treated at 1350°C for 2–4 h under argon gas flow. After heat-treatment, active graphite powders were successfully changed into MWCNTs with high purity. The XRD analyses showed that in the duration 150 h of milling, all the raw materials were changed to the desired materials. From the broadening of the diffraction lines in the XRD patterns, it was concluded that the graphite crystallites were nanosized, and raising the milling duration resulted in the fineness of the particles and the increase of the strain. The structure and morphology of MWCNTs were investigated using scanning electron microscopy (SEM and high-resolution transmission electron microscopy (HRTEM. The yield of MWCNTs was estimated through SEM and TEM observations of the as-prepared samples was to be about 90%. Indeed, mechanothermal method is of interest for fundamental understanding and improvement of commercial synthesis of carbon nanotubes (CNTs. As a matter of fact, the method of mechanothermal guarantees the production of MWCNTs suitable for different applications.

  8. Method for preparing a sinterable uranium dioxide powder

    International Nuclear Information System (INIS)

    Thornton, T.A.; Holaday, V.D. Jr.

    1985-01-01

    This invention provides an improved method for preparing a sinterable uranium dioxide powder for the preparation of nuclear fuel, using microwave radiation in a microwave induction furnace. The starting compound may be uranyl nitrate hexahydrate, ammonium diuranate or ammonium uranyl carbonate. The starting compound is heated in a microwave induction furnace for a period of time sufficient for compound decomposition. The decomposed compound is heated in a microwave induction furnace in a reducing atmosphere for a period of time sufficient to reduce the decomposed compound to uranium dioxide powder

  9. Chemical modification of carbon powders with aminophenyl and aryl-aliphatic amine groups by reduction of in situ generated diazonium cations: Applicability of the grafted powder towards CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Aurelie Grondein; Daniel Belanger [Universite du Quebec a Montreal, Montreal, PQ (Canada). Departement de Chimie

    2011-08-15

    Aminophenyl, p-aminobenzyl and p-aminoethylphenyl groups were grafted at the surface of carbon Vulcan XC72R by spontaneous reduction of the in situ generated diazonium cations from the corresponding amine. X-ray photoelectron spectroscopy and elemental analysis confirmed an amine loading of about 1 mmol/g. The grafting of amine functionalities leads to a decrease of specific surface area from 223 to about 110 m{sup 2}/g with a drastic loss of microporosity. Acid-base properties of the surface are also affected by the modification. Aminophenyl grafted groups make the surface more acidic while aryl-aliphatic amines groups tends to render it more basic. The grafted layer shows in each case a good thermal stability up to 250{sup o}C. The affinity of the modified powder towards CO{sub 2} and N{sub 2} has been evaluated by thermal swing adsorption. The maximum adsorption capacity of CO{sub 2} of modified carbons is lower than the unmodified carbon but the presence of the amine functionalities involves a better selectivity of the material towards CO{sub 2} adsorption in comparison of N{sub 2} adsorption. 53 refs., 9 figs., 3 tabs.

  10. Replacing Chlorine with Hydrogen Chloride as a Possible Reactant for Synthesis of Titanium Carbide Derived Carbon Powders for High-Technology Devices

    International Nuclear Information System (INIS)

    Tallo, Indrek; Thomberg, Thomas; Jänes, Alar; Lust, Enn

    2013-01-01

    Micro- and mesoporous carbide-derived carbons were synthesized from titanium carbide (TiC) powder via gas phase reaction by using different reactants (Cl 2 and HCl) within the temperature range from 700 to 1100 °C. Analysis of XRD results show that TiC-derived carbons (TiC-CDC) consist mainly of graphitic crystallites. The first-order Raman spectra showed the graphite-like absorption peaks at ∼1577 cm 1 and the disorder-induced peaks at ∼1338 cm- 1 . The energy-related properties of supercapacitors based on 1 M (C 2 H 5 ) 3 CH 3 NBF 4 in acetonitrile and carbide-derived carbons (TiC-CDC (Cl 2 ) and TiC-CDC (HCl)) as electrode materials were also investigated using cyclic voltammetry, electrochemical impedance spectroscopy, galvanostatic charge/discharge and constant power methods. The Ragone plots for carbide-derived carbons prepared by using different reactants (Cl 2 , HCl) are quite similar and at high power loads TiC-CDC (Cl 2 ) material synthesized at 900 °C, i.e. materials with optimal porous structure, deliver higher power at constant energy

  11. Flexural Properties of Activated Carbon Filled Epoxy Nano composites

    International Nuclear Information System (INIS)

    Khalil, H.P.S.A.; Khalil, H.P.S.A.; Alothman, O.Y.; Paridah, M.T.; Zainudin, E.S.

    2014-01-01

    Activated carbon (AC) filled epoxy nano composites obtained by mixing the desired amount of nano AC viz., bamboo stem, oil palm empty fruit bunch, and coconut shell from agricultural biomass with the epoxy resin. Flexural properties of activated carbons filled epoxy nano composites with 1 %, and 5 % filler loading were measured. In terms of flexural strength and modulus, a significant increment was observed with addition of 1 % vol and 5 % vol nano-activated carbon as compared to neat epoxy. The effect of activated carbon treated by two chemical agents (potassium hydroxide and phosphoric acid) on the flexural properties of epoxy nano composites were also investigated. Flexural strength of activated carbon-bamboo stem, activated carbon-oil palm, and activated carbon-coconut shell reinforced epoxy nano composites showed almost same value in case of 5 % potassium hydroxide activated carbon. Flexural strength of potassium hydroxide activated carbon-based epoxy nano composites was higher than phosphoric acid activated carbon. The flexural toughness of both the potassium hydroxide and phosphoric acid activated carbon reinforced composites range between 0.79 - 0.92 J. It attributed that developed activated carbon filled epoxy nano composites can be used in different applications. (author)

  12. SHS synthesis of Si-SiC composite powders using Mg and reactants from industrial waste

    Science.gov (United States)

    Chanadee, Tawat

    2017-11-01

    Si-SiC composite powders were synthesized by self-propagating high-temperature synthesis (SHS) using reactants of fly ash-based silica, sawdust-based activated carbon, and magnesium. Fly ash-based silica and sawdust-based activated carbon were prepared from coal mining fly ash and Para rubber-wood sawdust, respectively. The work investigated the effects of the synthesis atmosphere (air and Ar) on the phase and morphology of the SHS products. The SHS product was leached by a two-step acid leaching processes, to obtain the Si-SiC composite powder. The SHS product and SHS product after leaching were characterized by X-ray diffractometry, scanning electron microscopy and energy dispersive X-ray spectrometry. The results indicated that the SHS product synthesized in air consisted of Si, SiC, MgO, and intermediate phases (SiO2, Mg, Mg2SiO4, Mg2Si), whereas the SHS product synthesized in Ar consisted of Si, SiC, MgO and a little Mg2SiO4. The SiC content in the leached-SHS product was higher when Ar was used as the synthesis atmosphere. As well as affecting the purity, the synthesis atmospheres also affected the average crystalline sizes of the products. The crystalline size of the product synthesized in Ar was smaller than that of the product synthesized in air. All of the results showed that fly ash and sawdust could be effective waste-material reactants for the synthesis of Si-SiC composite powders.

  13. Theory of super LIE groups

    International Nuclear Information System (INIS)

    Prakash, M.

    1985-01-01

    The theory of supergravity has attracted increasing attention in the recent years as a unified theory of elementary particle interactions. The superspace formulation of the theory is highly suggestive of an underlying geometrical structure of superspace. It also incorporates the beautifully geometrical general theory of relativity. It leads us to believe that a better understanding of its geometry would result in a better understanding of the theory itself, and furthermore, that the geometry of superspace would also have physical consequences. As a first step towards that goal, we develop here a theory of super Lie groups. These are groups that have the same relation to a super Lie algebra as Lie groups have to a Lie algebra. More precisely, a super Lie group is a super-manifold and a group such that the group operations are super-analytic. The super Lie algebra of a super Lie group is related to the local properties of the group near the identity. This work develops the algebraic and super-analytical tools necessary for our theory, including proofs of a set of existence and uniqueness theorems for a class of super-differential equations

  14. Degradation of metaldehyde in water by nanoparticle catalysts and powdered activated carbon.

    Science.gov (United States)

    Li, Zhuojun; Kim, Jong Kyu; Chaudhari, Vrushali; Mayadevi, Suseeladevi; Campos, Luiza C

    2017-07-01

    Metaldehyde, an organic pesticide widely used in the UK, has been detected in drinking water in the UK with a low concentration (doped titanium dioxide nanocatalyst with different concentrations of carbon (C-1.5, C-40, and C-80) for metaldehyde removal from aqueous solutions by adsorption and oxidation via photocatalysis. PAC was found to be the most effective material which showed almost over 90% removal. Adsorption data were well fitted to the Langmuir isotherm model, giving a q m (maximum/saturation adsorption capacity) value of 32.258 mg g -1 and a K L (Langmuir constant) value of 2.013 L mg -1 . In terms of kinetic study, adsorption of metaldehyde by PAC fitted well with a pseudo-second-order equation, giving the adsorption rate constant k 2 value of 0.023 g mg -1  min -1 , implying rapid adsorption. The nanocatalysts were much less effective in oxidising metaldehyde than PAC with the same metaldehyde concentration and 0.2 g L -1 loading concentration of materials under UV light; the maximum removal achieved by carbon-doped titanium dioxide (C-1.5) nanocatalyst was around 15% for a 7.5 ppm metaldehyde solution. Graphical abstract ᅟ.

  15. Detoxification of Eucheuma spinosum Hydrolysates with Activated Carbon for Ethanol Production by the Salt-Tolerant Yeast Candida tropicalis.

    Science.gov (United States)

    Ra, Chae Hun; Jung, Jang Hyun; Sunwoo, In Young; Kang, Chang Han; Jeong, Gwi-Taek; Kim, Sung-Koo

    2015-06-01

    The objective of this study was to optimize the slurry contents and salt concentrations for ethanol production from hydrolysates of the seaweed Eucheuma spinosum. A monosaccharide concentration of 44.2 g/l as 49.6% conversion of total carbohydrate of 89.1 g/l was obtained from 120 g dw/l seaweed slurry. Monosaccharides from E. spinosum slurry were obtained by thermal acid hydrolysis and enzymatic hydrolysis. Addition of activated carbon at 2.5% (w/v) and the adsorption time of 2 min were used in subsequent adsorption treatments to prevent the inhibitory effect of HMF. The adsorption surface area of the activated carbon powder was 1,400-1,600 m(2)/g and showed selectivity to 5-hydroxymethyl furfural (HMF) from monosaccharides. Candida tropicalis KCTC 7212 was cultured in yeast extract, peptone, glucose, and high-salt medium, and exposed to 80, 90, 100, and 110 practical salinity unit (psu) salt concentrations in the lysates. The 100 psu salt concentration showed maximum cell growth and ethanol production. The ethanol fermentations with activated carbon treatment and use of C. tropicalis acclimated to a high salt concentration of 100 psu produced 17.9 g/l of ethanol with a yield (YEtOH) of 0.40 from E. spinosum seaweed.

  16. Algebra & trigonometry super review

    CERN Document Server

    2012-01-01

    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Algebra and Trigonometry Super Review includes sets and set operations, number systems and fundamental algebraic laws and operations, exponents and radicals, polynomials and rational expressions, equations, linear equations and systems of linear equations, inequalities, relations and functions, quadratic equations, equations of higher order, ratios, proportions, and variations. Take the Super Review quizzes to see how much y

  17. Properies of binder systems containing cement, fly ash, and limestone powder

    Directory of Open Access Journals (Sweden)

    Krittiya Kaewmanee

    2014-10-01

    Full Text Available Fly ash and limestone powder are two major widely available cement replacing materials in Thailand. However, the current utilization of these materials is still not optimized due to limited information on properties of multi-binder systems. This paper reports on the mechanical and durability properties of mixtures containing cement, fly ash, and limestone powder as single, binary, and ternary binder systems. The results showed that a single binder system consisting of only cement gave the best carbonation resistance. A binary binder system with fly ash exhibited superior performances in long-term compressive strength and many durability properties except carbonation and magnesium sulfate resistances, while early compressive strength of a binary binder system with limestone powder was excellent. The ternary binder system, taking the most benefit of selective cement replacing materials, yielded, though not the best, satisfactory performances in almost all properties. Thus, the optimization of binders can be achieved through a multi-binder system.

  18. Thermal analysis studies of ammonium uranyl carbonate

    International Nuclear Information System (INIS)

    Cao Xinsheng; Ma Xuezhong; Wang Fapin; Liu Naixin; Ji Changhong

    1988-01-01

    The simultaneous thermogravimetry and differential thermal analysis of the ammonium uranyl carbonate powder were performed with heat balance in the following atmosphers: Air, Ar and Ar-8%H 2 . The thermogravimetry and differential thermal analysis curves of the ammonium uranyl carbonate powder obtained from different source were reported and discussed

  19. Investigation on the formation of Cu-Fe nano crystalline super-saturated solid solution developed by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, M., E-mail: m.mojtahedi@gmail.com [School of Materials Science and Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Goodarzi, M.; Aboutalebi, M.R. [School of Materials Science and Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Ghaffari, M. [Department of Electrical and Electronics Engineering, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Soleimanian, V. [Department of Physics, Faculty of Science, Shahrekord University, P.O. Box 115, Shahrekord (Iran, Islamic Republic of)

    2013-02-15

    Highlights: Black-Right-Pointing-Pointer The deformation of the mechanically alloyed Cu-Fe powder is anisotropic. Black-Right-Pointing-Pointer The Rietveld method is more proper and results in smaller crystallite size than the Scherer and Williamson-Hall methods. Black-Right-Pointing-Pointer A dual phase super saturated solid solution achieved after 96 h of milling of the mixtures with 30, 50 and 70 wt.% of Iron. Black-Right-Pointing-Pointer A final proportion of approximately 85% FCC and 15% BCC structure obtained in all of the applied compositions. - Abstract: In this study, the formation of super saturated solid solution in the binary Cu-Fe system was investigated. Three powder blends with 30, 50 and 70 wt.% of Fe were milled for different times to 96 h. The variations of lattice parameter and inter-planar spacing were calculated and analyzed using X-ray diffraction analysis (XDA). The anisotropy of lattice deformation in the FCC phase was studied and the obtained results were compared to milled pure Cu powder. Furthermore, crystallite size was calculated using Scherer formula in comparison with Rietveld full profile refinement method. Considering the previous studies about the formation of non-equilibrium FCC and BCC phases, the phase evolution has been discussed and the proportion of each phase was calculated using Rietveld refinement method. Supplementary studies on the evolution of microstructure and formation of solid solution were carried out using high resolution transmission electron microscopy (HRTEM). Finally, high angle annular dark field (HAADF) imaging was utilized to find out the level of homogeneity in the resulting phases. While true alloying takes place in each phase, the final structure consists of both FCC and BCC nano-crystallites.

  20. Phenolic Profiles and Contribution of Individual Compounds to Antioxidant Activity of Apple Powders.

    Science.gov (United States)

    Raudone, Lina; Raudonis, Raimondas; Liaudanskas, Mindaugas; Viskelis, Jonas; Pukalskas, Audrius; Janulis, Valdimaras

    2016-05-01

    Apples (Malus domestica L.) are the most common source of phenolic compounds in northern European diet. Besides pectins, dietary fibers, vitamins, and oligosaccharides they contain phenolic compounds of different classes. Apple powders are convenient functional forms retaining significant amounts of phenolic antioxidants. In this study reducing and radical scavenging profiles of freeze-dried powders of "Aldas,ˮ "Auksis,ˮ "Connel Red,ˮ "Ligol,ˮ "Lodel,ˮ and "Rajkaˮ were determined and phenolic constituents were identified using ultra high-performance liquid chromatography coupled to quadrupole and time-of-flight mass spectrometers. A negative ionization mode was applied and seventeen compounds: phenolic acids (coumaroylquinic, chlorogenic), flavonoids (quercetin derivatives), and procyanidin derivatives (B1, B2, and C1) were identified in all tested apple samples. Total values of Trolox equivalents varied from 7.72 ± 0.32 up to 20.02 ± 0.52 and from 11.10 ± 0.57 up to 21.42 ± 0.75 μmol/g of dry weight of apple powder in FRAP (ferric reducing antioxidant power) and ABTS (2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) postcolumn assays, respectively. The greatest Trolox equivalent values were determined for apples of "Aldasˮ cultivar. Chlorogenic acid and procyanidin C1 were the most significant contributors to total reducing and radical scavenging activity in all apple cultivars tested, therefore they could be considered as markers of antioxidant activity. © 2016 Institute of Food Technologists®

  1. Melting in super-earths.

    Science.gov (United States)

    Stixrude, Lars

    2014-04-28

    We examine the possible extent of melting in rock-iron super-earths, focusing on those in the habitable zone. We consider the energetics of accretion and core formation, the timescale of cooling and its dependence on viscosity and partial melting, thermal regulation via the temperature dependence of viscosity, and the melting curves of rock and iron components at the ultra-high pressures characteristic of super-earths. We find that the efficiency of kinetic energy deposition during accretion increases with planetary mass; considering the likely role of giant impacts and core formation, we find that super-earths probably complete their accretionary phase in an entirely molten state. Considerations of thermal regulation lead us to propose model temperature profiles of super-earths that are controlled by silicate melting. We estimate melting curves of iron and rock components up to the extreme pressures characteristic of super-earth interiors based on existing experimental and ab initio results and scaling laws. We construct super-earth thermal models by solving the equations of mass conservation and hydrostatic equilibrium, together with equations of state of rock and iron components. We set the potential temperature at the core-mantle boundary and at the surface to the local silicate melting temperature. We find that ancient (∼4 Gyr) super-earths may be partially molten at the top and bottom of their mantles, and that mantle convection is sufficiently vigorous to sustain dynamo action over the whole range of super-earth masses.

  2. Predicting the occurrence of super-storms

    Directory of Open Access Journals (Sweden)

    N. Srivastava

    2005-11-01

    Full Text Available A comparative study of five super-storms (Dst<-300 nT of the current solar cycle after the launch of SoHO, to identify solar and interplanetary variables that influence the magnitude of resulting geomagnetic storms, is described. Amongst solar variables, the initial speed of a CME is considered the most reliable predictor of the strength of the associated geomagnetic storm because fast mass ejections are responsible for building up the ram pressure at the Earth's magnetosphere. However, although most of the super-storms studied were associated with high speed CMEs, the Dst index of the resulting geomagnetic storms varied between -300 to -472 nT. The most intense storm of 20 November 2003, (Dst ~ -472 nT had its source in a comparatively smaller active region and was associated with a relatively weaker, M-class flare while all other super-storms had their origins in large active regions and were associated with strong X-class flares. However, this superstorm did not show any associated extraordinary solar and interplanetary characteristics. The study also reveals the challenge in the reliable prediction of the magnitude of a geomagnetic storm from solar and interplanetary variables.

  3. Preparation of Three-Dimensional Graphene Foams Using Powder Metallurgy Templates.

    Science.gov (United States)

    Sha, Junwei; Gao, Caitian; Lee, Seoung-Ki; Li, Yilun; Zhao, Naiqin; Tour, James M

    2016-01-26

    A simple and scalable method which combines traditional powder metallurgy and chemical vapor deposition is developed for the synthesis of mesoporous free-standing 3D graphene foams. The powder metallurgy templates for 3D graphene foams (PMT-GFs) consist of particle-like carbon shells which are connected by multilayered graphene that shows high specific surface area (1080 m(2) g(-1)), good crystallization, good electrical conductivity (13.8 S cm(-1)), and a mechanically robust structure. The PMT-GFs did not break under direct flushing with DI water, and they were able to recover after being compressed. These properties indicate promising applications of PMT-GFs for fields requiring 3D carbon frameworks such as in energy-based electrodes and mechanical dampening.

  4. Activated carbon from peach stones using phosphoric acid activation at medium temperatures.

    Science.gov (United States)

    Kim, Dong-Su

    2004-01-01

    In the present study, the activation features of phosphoric acid have been investigated using waste peach stones as the raw material in the production of granular activated carbon. Thermogravimetry/differential thermal analysis was conducted to characterize the thermal behavior of peach stone and titration method was used to evaluate the adsorption capacity of the produced activated carbon. It was observed that the iodine value of the activated carbon increased with activation temperature. However, temperatures higher than 500 degrees C caused a thermal destruction, which resulted in the decrease of the adsorption capacity. Activation longer than 1.5 h at 500 degrees C resulted in thermal degradation of the porous structure of the activated carbon. The adsorption capacity was enhanced with increasing of amounts of phosphoric acid, however, excessive phosphoric acid caused a decrease in the iodine value. In addition, it was found that the carbon yields generally decreased with activation temperature and activation time. Scanning electron microscopy analysis was conducted to observe the changes in the poros structure of the activated carbon produced in different temperatures. Activation of carbon by phosphoric acid was found to be superior to that by CaCl2 and gas activation. The activated carbon produced from peach stone was applied as an adsorbent in the treatment of synthesized wastewater containing cadmium ion and its adsorption capacity was found to be as good as that of the commercial one.

  5. Laser-induced breakdown spectroscopy measurements of uranium and thorium powders and uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Elizabeth J. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Barefield, James E., E-mail: jbarefield@lanl.gov [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berg, John M. [Manufacturing Engineering and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Clegg, Samuel M.; Havrilla, George J.; Montoya, Velma M.; Le, Loan A.; Lopez, Leon N. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-05-01

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze depleted uranium and thorium oxide powders and uranium ore as a potential rapid in situ analysis technique in nuclear production facilities, environmental sampling, and in-field forensic applications. Material such as pressed pellets and metals, has been extensively studied using LIBS due to the high density of the material and more stable laser-induced plasma formation. Powders, on the other hand, are difficult to analyze using LIBS since ejection and removal of the powder occur in the laser interaction region. The capability of analyzing powders is important in allowing for rapid analysis of suspicious materials, environmental samples, or trace contamination on surfaces since it most closely represents field samples (soil, small particles, debris etc.). The rapid, in situ analysis of samples, including nuclear materials, also reduces costs in sample collection, transportation, sample preparation, and analysis time. Here we demonstrate the detection of actinides in oxide powders and within a uranium ore sample as both pressed pellets and powders on carbon adhesive discs for spectral comparison. The acquired LIBS spectra for both forms of the samples differ in overall intensity but yield a similar distribution of atomic emission spectral lines. - Highlights: • LIBS analysis of mixed actinide samples: depleted uranium oxide and thorium oxide • LIBS analysis of actinide samples in powder form on carbon adhesive discs • Detection of uranium in a complex matrix (uranium ore) as a precursor to analyzing uranium in environmental samples.

  6. Strain-enhanced sintering of iron powders

    Energy Technology Data Exchange (ETDEWEB)

    Amador, D.R.; Torralba, J.M. [Universidad Carlos III de Madrid, Departamento de Ciencias de Materiales e Ingenieria Metalurgica, Leganes, Madrid (Spain); Monge, M.A.; Pareja, R. [Universidad Carlos III de Madrid, Departamento de Fisica, Madrid (Spain)

    2005-02-01

    Sintering of ball-milled and un-milled Fe powders has been investigated using dilatometry, X-ray, density, and positron annihilation techniques. A considerable sintering enhancement is found in milled powders showing apparent activation energies that range between 0.44 and 0.80 eV/at. The positron annihilation results, combined with the evolution of the shrinkage rate with sintering temperature, indicate generation of lattice defects during the sintering process of milled and un-milled powders. The sintering enhancement is attributed to pipe diffusion along the core of moving dislocations in the presence of the vacancy excess produced by plastic deformation. Positron annihilation results do not reveal the presence of sintering-induced defects in un-milled powders sintered above 1200 K, the apparent activation energy being in good agreement with that for grain-boundary diffusion in {gamma}-Fe. (orig.)

  7. SuperB Progress Report: Detector

    Energy Technology Data Exchange (ETDEWEB)

    Grauges, E.; /Barcelona U., ECM; Donvito, G.; Spinoso, V.; /INFN, Bari /Bari U.; Manghisoni, M.; Re, V.; Traversi, G.; /INFN, Pavia /Bergamo U., Ingengneria Dept.; Eigen, G.; Fehlker, D.; Helleve, L.; /Bergen U.; Carbone, A.; Di Sipio, R.; Gabrielli, A.; Galli, D.; Giorgi, F.; Marconi, U.; Perazzini, S.; Sbarra, C.; Vagnoni, V.; Valentinetti, S.; Villa, M.; Zoccoli, A.; /INFN, Bologna /Bologna U. /Caltech /Carleton U. /Cincinnati U. /INFN, CNAF /INFN, Ferrara /Ferrara U. /UC, Irvine /Taras Shevchenko U. /Orsay, LAL /LBL, Berkeley /UC, Berkeley /Frascati /INFN, Legnaro /Orsay, IPN /Maryland U. /McGill U. /INFN, Milan /Milan U. /INFN, Naples /Naples U. /Novosibirsk, IYF /INFN, Padua /Padua U. /INFN, Pavia /Pavia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Caltech /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore /PNL, Richland /Queen Mary, U. of London /Rutherford /INFN, Rome /Rome U. /INFN, Rome2 /Rome U.,Tor Vergata /INFN, Rome3 /Rome III U. /SLAC /Tel Aviv U. /INFN, Turin /Turin U. /INFN, Padua /Trento U. /INFN, Trieste /Trieste U. /TRIUMF /British Columbia U. /Montreal U. /Victoria U.

    2012-02-14

    This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  8. SuperB Progress Report: Detector

    International Nuclear Information System (INIS)

    Grauges, E.; Donvito, G.; Spinoso, V.; Manghisoni, M.; Re, V.; Traversi, G.; Eigen, G.; Fehlker, D.; Helleve, L.; Cheng, C.; Chivukula, A.; Doll, D.; Echenard, B.; Hitlin, D.; Ongmongkolkul, P.; Porter, F.; Rakitin, A.; Thomas, M.; Zhu, R.; Tatishvili, G.; Andreassen, R.; Fabby, C.; Meadows, B.; Simpson, A.; Sokoloff, M.; Tomko, K.; Fella, A.; Andreotti, M.; Baldini, W.; Calabrese, R.; Carassiti, V.; Cibinetto, G.; Cotta Ramusino, A.; Gianoli, A.; Luppi, E.; Munerato, M.; Santoro, V.; Tomassetti, L.; Stoker, D.; Bezshyyko, O.; Dolinska, G.; Arnaud, N.; Beigbeder, C.; Bogard, F.; Breton, D.; Burmistrov, L.; Charlet, D.; Maalmi, J.; Perez Perez, L.; Puill, V.; Stocchi, A.; Tocut, V.; Wallon, S.; Wormser, G.; Brown, D.

    2012-01-01

    This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  9. SuperB Progress Reports Accelerator

    CERN Document Server

    Biagini, Maria Enrica; Boscolo, M; Buonomo, B; Demma, T; Drago, A; Esposito, M; Guiducci, S; Mazzitelli, G; Pellegrino, L; Preger, M A; Raimondi, P; Ricci, R; Rotundo, U; Sanelli, C; Serio, M; Stella, A; Tomassini, S; Zobov, M; Bertsche, K; Brachman, A; Cai, Y; Chao, A; Chesnut, R; Donald, M.H; Field, C; Fisher, A; Kharakh, D; Krasnykh, A; Moffeit, K; Nosochkov, Y; Pivi, M; Seeman, J; Sullivan, M.K; Weathersby, S; Weidemann, A; Weisend, J; Wienands, U; Wittmer, W; Woods, M; Yocky, G; Bogomiagkov, A; Koop, I; Levichev, E; Nikitin, S; Okunev, I; Piminov, P; Sinyatkin, S; Shatilov, D; Vobly, P; Bosi, F; Liuzzo, S; Paoloni, E; Bonis, J; Chehab, R; Le Meur, G; Lepercq, P; Letellier-Cohen, F; Mercier, B; Poirier, F; Prevost, C; Rimbault, C; Touze, F; Variola, A; Bolzon, B; Brunetti, L; Jeremie, A; Baylac, M; Bourrion, O; De Conto, J M; Gomez, Y; Meot, F; Monseu, N; Tourres, D; Vescovi, C; Chanci, A; Napoly, O; Barber, D P; Bettoni, S; Quatraro, D

    2010-01-01

    This report details the present status of the Accelerator design for the SuperB Project. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  10. A study of the oriented composites with the conductive segregated structure obtained via solid-phase processing of the UHMWPE reactor powder mixed with the carbon nanofillers

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Oleg V. [Moscow Institute of Physics and Technology (State University,) Institutskiy per., Dolgoprudny, Moscow Region, 141700 (Russian Federation); N.S. Enikolopov Institute of Synthetic Polymer Materials of RAS, Profsoyuznaya st., Moscow, 117393 (Russian Federation); Kechek’yan, Alexander S.; Shevchenko, Vitaly G.; Kurkin, Tikhon S.; Golubev, Evgeny K.; Ozerin, Alexander N. [N.S. Enikolopov Institute of Synthetic Polymer Materials of RAS, Profsoyuznaya st., Moscow, 117393 (Russian Federation); Karpushkin, Evgeny A.; Sergeev, Vladimir G. [Moscow State University, Chemical Department, Leninskie Gori, Moscow, 119234 (Russian Federation)

    2016-05-18

    Electrically conductive oriented polymer nano-composites of different compositions, based on the reactor powder of ultra-high-molecular-weight polyethylene (UHMWPE) with a special morphology, filled with particles of nanostructured graphite (NG), multi-walled carbon nanotubes (MWCNTs), and electrically conductive carbon black (CB), were investigated. Polymer composites were obtained via compaction of the mechanical mixture of the polymer and filler powder, followed by uniaxial deformation of the material under homogeneous shear (HS) conditions (all of the processing stages were conducted at room temperature). Resulted composites possess a high tensile strength, high level of the electrical conductivity and low percolation threshold, owing it to the formation of the segregated conductive structure, The influence of the type of nanosized carbon filler, degree of the deformation under HS condition, temperature and etc. on the electrical conductivity and mechanical properties of strengthened conductive composites oriented under homogeneous shear conditions was investigated. Changes in the electrical conductivity of oriented composite materials during reversible “tension–shrinkage” cycles along the orientation axis direction were studied. A theoretical approach, describing the process of transformation of the conductive system as a response on polymer phase deformation and volume change, was proposed, based on the data received from the analysis of the conductivity behavior during the uniaxial deformation and thermal treatment of composites.

  11. Electrophoretic deposition of carbon nanotubes on a carbon fiber surface with different index graphitization

    International Nuclear Information System (INIS)

    Almeida, E.C.; Baldan, M.R.; Ferreira, N.G.; Edwards, E.R.

    2009-01-01

    Full text: The purpose of this work is to examine the electrophoretic deposition of carbon nanotubes powder on carbon fibers, produced at different heat treatments temperatures. Besides, a systematic study of the effects of graphitization index from substrate on the structure and morphology of CNTs has been available. Carbon fibers were produced from polyacrylonitrile at three different heat treatments temperatures, 1000, 1500 and 2000 deg C. The carbon fibers microstructure or its graphitization index may be controlled by the heat treatments temperatures. The electrophoretic deposition of carbon nanotubes was obtained with the powder of carbon nanotubes dispersed in water by ultrasonication to obtain dispersions of 0.05 mg/mL. The carbon fibers were immersed in the nanotube dispersion, and a positive potential of 10 V/cm was applied. Morphology and microstructure of carbon nanotubes on carbon fibers were obtained by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. (author)

  12. Removal of cationic surfactant (CTAB from aqueous solution on to activated carbon obtained from corncob.

    Directory of Open Access Journals (Sweden)

    S. M. Yakout

    2009-05-01

    Full Text Available Direct and indirect releases of large quantities of surfactants to the environment may result in serious health and environmental problems. Therefore, surfactants should be removed from water before water is released to the environment or delivered for public use. Using powdered activated carbon (PAC as adsorbent may be an effective technique to remove surfactants. In this study, the removal of surfactants by PAC was investigated and the influencesof the operating parameters on the effectiveness on adsorption rate were studied. Cationic surfactant, Cetyl trimethyl ammonium bromide (CTAB was selected for the experiments. A series of batch experiments were performed to determine the sorption isotherms of surfactants to PAC. The results showed that carbon structure affect mainly on the surfactant adsorption. Surfactant equilibrium data fitted very well to the binary langmuir model. The pseudo first-,second- order and intraparticle diffusion kinetic models were applied. Both, the external mass transfer and intraparticle diffusion mechanisms involve in CTAB sorption.

  13. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

    2003-09-30

    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be

  14. Deformations of super Riemann surfaces

    International Nuclear Information System (INIS)

    Ninnemann, H.

    1992-01-01

    Two different approaches to (Konstant-Leites-) super Riemann surfaces are investigated. In the local approach, i.e. glueing open superdomains by superconformal transition functions, deformations of the superconformal structure are discussed. On the other hand, the representation of compact super Riemann surfaces of genus greater than one as a fundamental domain in the Poincare upper half-plane provides a simple description of super Laplace operators acting on automorphic p-forms. Considering purely odd deformations of super Riemann surfaces, the number of linear independent holomorphic sections of arbitrary holomorphic line bundles will be shown to be independent of the odd moduli, leading to a simple proof of the Riemann-Roch theorem for compact super Riemann surfaces. As a further consequence, the explicit connections between determinants of super Laplacians and Selberg's super zeta functions can be determined, allowing to calculate at least the 2-loop contribution to the fermionic string partition function. (orig.)

  15. Deformations of super Riemann surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ninnemann, H [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    1992-11-01

    Two different approaches to (Konstant-Leites-) super Riemann surfaces are investigated. In the local approach, i.e. glueing open superdomains by superconformal transition functions, deformations of the superconformal structure are discussed. On the other hand, the representation of compact super Riemann surfaces of genus greater than one as a fundamental domain in the Poincare upper half-plane provides a simple description of super Laplace operators acting on automorphic p-forms. Considering purely odd deformations of super Riemann surfaces, the number of linear independent holomorphic sections of arbitrary holomorphic line bundles will be shown to be independent of the odd moduli, leading to a simple proof of the Riemann-Roch theorem for compact super Riemann surfaces. As a further consequence, the explicit connections between determinants of super Laplacians and Selberg's super zeta functions can be determined, allowing to calculate at least the 2-loop contribution to the fermionic string partition function. (orig.).

  16. Promoting effect of active carbons on methanol dehydrogenation on sodium carbonate - hydrogen spillover

    OpenAIRE

    Su, S.; Prairie, M.; Renken, A.

    1993-01-01

    Methanol dehydrogenation to formaldehyde was conducted in a fixed-bed flow reactor with sodium carbonate catalyst mixed with active carbons or transition metals. The additives promoted the reaction rate at 880-970 K without modifying formaldehyde selectivity. This effect increases with increasing carbon content in the carbon-carbonate mixture. Activation energy of methanol conversion is the same for the mixture and the carbonate alone. Temperature-programmed desorption experiments showed that...

  17. Template-mediated, Hierarchical Engineering of Ordered Mesoporous Films and Powders

    Science.gov (United States)

    Tian, Zheng

    Hierarchical control over pore size, pore topology, and meso/mictrostructure as well as material morphology (e.g., powders, monoliths, thin films) is crucial for meeting diverse materials needs among applications spanning next generation catalysts, sensors, batteries, sorbents, etc. The overarching goal of this thesis is to establish fundamental mechanistic insight enabling new strategies for realizing such hierarchical textural control for carbon materials that is not currently achievable with sacrificial pore formation by 'one-pot' surfactant-based 'soft'-templating or multi-step inorganic 'hard-templating. While 'hard'-templating is often tacitly discounted based upon its perceived complexity, it offers potential for overcoming key 'soft'-templating challenges, including bolstering pore stability, accommodating a more versatile palette of replica precursors, realizing ordered/spanning porosity in the case of porous thin films, simplifying formation of bi-continuous pore topologies, and inducing microstructure control within porous replica materials. In this thesis, we establish strategies for hard-templating of hierarchically porous and structured carbon powders and tunable thin films by both multi-step hard-templating and a new 'one-pot' template-replica precursor co-assembly process. We first develop a nominal hard-templating technique to successfully prepare three-dimensionally ordered mesoporous (3DOm) and 3DOm-supported microporous carbon thin films by exploiting our ability to synthesize and assemble size-tunable silica nanoparticles into scalable, colloidal crystalline thin film templates of tunable mono- to multi-layer thickness. This robust thin film template accommodates liquid and/or vapor-phase infiltration, polymerization, and pyrolysis of various carbon sources without pore contraction and/or collapse upon template sacrifice. The result is robust, flexible 3DOm or 3DOm-supported ultra-thin microporous films that can be transferred by stamp

  18. Development of activated carbon pore structure via physical and chemical activation of biomass fibre waste

    International Nuclear Information System (INIS)

    Williams, Paul T.; Reed, Anton R.

    2006-01-01

    Biomass waste in the form of biomass flax fibre, produced as a by-product of the textile industry was processed via both physical and chemical activation to produce activated carbons. The surface area of the physically activated carbons were up to 840 m 2 g -1 and the carbons were of mesoporous structure. Chemical activation using zinc chloride produced high surface area activated carbons up to 2400 m 2 g -1 and the pore size distribution was mainly microporous. However, the process conditions of temperature and zinc chloride concentration could be used to manipulate the surface area and porosity of the carbons to produce microporous, mesoporous and mixed microporous/mesoporous activated carbons. The physically activated carbons were found to be a mixture of Type I and Type IV carbons and the chemically activated carbons were found to be mainly Type I carbons. The development of surface morphology of physically and chemically activated carbons observed via scanning electron microscopy showed that physical activation produced activated carbons with a nodular and pitted surface morphology whereas activated carbons produced through chemical activation had a smooth surface morphology. Transmission electron microscopy analysis could identify mesopore structures in the physically activated carbon and microporous structures in the chemically activated carbons

  19. Black Ink of Activated Carbon Derived From Palm Kernel Cake (PKC)

    Science.gov (United States)

    Selamat, M. H.; Ahmad, A. H.

    2009-06-01

    Recycling the waste from natural plant to produce useful end products will benefit many industries and help preserve the environment. The research reported in this paper is an investigation on the use of the natural waste of palm kernel cake (PKC) to produce carbon residue as a black carbon for pigment source by using pyrolysis process. The activated carbons (AC) is produced in powder form using ball milling process. Rheological spectra in ink is one of quality control process in determining its performance properties. Findings from this study will help expand the scientific knowledge-base for black ink production and formulation base on PKC. Various inks with different weight percentage compositions of AC will be made and tested against its respective rheological properties in order to determine ideal ink printing system. The items in the formulation used comprised of organic and bio-waste materials with added additive to improve the quality of the black ink. Modified Polyurethane was used as binder. The binder's properties highlighted an ideal vehicle to be applied for good black ink opacity performance. The rheological behaviour is a general foundation for ink characterization where the wt% of AC-PKC resulted in different pseudoplastic behaviors, including the Newtonian behavior. The result found that Newtonian field was located in between 2 wt% and 10 wt% of AC-PKC composition with binder. Mass spectroscopy results shown that the carbon content in PKC is high and very suitable for black performance. In the ageing test, the pigment of PKC perform fairly according to the standard pigment of Black carbon (CB) of ferum oxide pigment. The contact angle for substrate's wettability of the ink system shown a good angle proven to be a water resistive coating on paper subtrates; an advantage of the PKC ink pigment performance.

  20. Making Activated Carbon by Wet Pressurized Pyrolysis

    Science.gov (United States)

    Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

    2006-01-01

    A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

  1. Evaluation of single-step steam pyrolysis-activated carbons

    African Journals Online (AJOL)

    Mgina

    Activated carbon has been widely used worldwide as an effective filtration or adsorption ... of producing activated carbon (AC) from local agroforestry residues by ..... impurities from waste water. .... Production of granular activated carbon.

  2. The development of an alternative thermoplastic powder prepregging technique

    Science.gov (United States)

    Ogden, A. L.; Hyer, M. W.; Wilkes, G. L.; Loos, A. C.

    1992-01-01

    An alternative powder prepregging technique is discussed that is based on the deposition of powder onto carbon fibers that have been moistened using an ultrasonic humidifier. The dry fiber tow is initially spread to allow a greater amount of the fiber surface to be exposed to the powder, thus ensuring a significant amount of intimate contact between the fiber and the matrix. Moisture in the form of ultrafine water droplets is then deposited onto the spread fiber tow. The moisture promotes adhesion to the fiber until the powder can be tacked to the fibers by melting. Powdered resin is then sieved onto the fibers and then tacked onto the fibers by quick heating in a convective oven. This study focuses on the production of prepregs and laminates made with LaRC-TPI (thermoplastic polyimide) using this process. Although the process appears to be successful, early evaluation was hampered by poor interfacial adhesion. The adhesion problem, however, seems to be the result of a material system incompatibility, rather than being influenced by the process.

  3. Erosion of common structural materials and the degradation of suspended particles in flowing suspension of graphite powder in carbon dioxide gas

    International Nuclear Information System (INIS)

    Garton, D.A.; Hawes, R.I.; Rose, P.W.

    1968-06-01

    Experiments have been performed to examine the erosion of common materials of construction by a flowing suspension of graphite powder in carbon dioxide gas and the degradation of the graphite powder in the suspension. The suspension was circulated through a stainless steel loop at a pressure of 200 p.s.i.g. and bulk fluid temperature of 100-150 deg. C. No change in the weight of pins of mild steel, stainless steel and zircaloy, which were placed across the flow stream in a region where the velocity approached 100 ft./sec, could be detected after 350 hours of circulation. Examination of micro-photographs of the cross sections of the specimens showed no change in the structure of the metals. Considerable erosion of graphite pins producing a 6% decrease in the weight was observed under similar conditions. Detailed spectrographic analysis of the suspended powder taken at various times during the experiment showed no noticeable increase in the impurity content which could be attributed to erosion of the test specimens. A considerable increase in the tungsten, tin and cobalt concentration was observed and this is attributed to wear of the pump seal surfaces. The mean particle size of the suspended graphite powder was observed to decrease rapidly from 5 microns to 3 microns after only a few hours of circulation in the loop. After this initial period there was little further change in the particle size, the mean diameter being 2.85 microns after 167 hours of circulation. (author)

  4. Super periodic potential

    Science.gov (United States)

    Hasan, Mohammd; Mandal, Bhabani Prasad

    2018-04-01

    In this paper we introduce the concept of super periodic potential (SPP) of arbitrary order n, n ∈I+, in one dimension. General theory of wave propagation through SPP of order n is presented and the reflection and transmission coefficients are derived in their closed analytical form by transfer matrix formulation. We present scattering features of super periodic rectangular potential and super periodic delta potential as special cases of SPP. It is found that the symmetric self-similarity is the special case of super periodicity. Thus by identifying a symmetric fractal potential as special cases of SPP, one can obtain the tunnelling amplitude for a particle from such fractal potential. By using the formalism of SPP we obtain the close form expression of tunnelling amplitude of a particle for general Cantor and Smith-Volterra-Cantor potentials.

  5. Weak hydrogen bonding interactions influence slip system activity and compaction behavior of pharmaceutical powders.

    Science.gov (United States)

    Khomane, Kailas S; Bansal, Arvind K

    2013-12-01

    Markedly different mechanical behavior of powders of polymorphs, cocrystals, hydrate/anhydrate pairs, or structurally similar molecules has been attributed to the presence of active slip planes system in their crystal structures. Presence of slip planes in the crystal lattice allows easier slip under the applied compaction pressure. This allows greater plastic deformation of the powder and results into increased interparticulate bonding area and greater tensile strength of the compacts. Thus, based on this crystallographic feature, tableting performance of the active pharmaceutical ingredients can be predicted. Recently, we encountered a case where larger numbers of CH···O type interactions across the proposed slip planes hinder the slip and thus resist plastic deformation of the powder under the applied compaction pressure. Hence, attention must be given to these types of interactions while identifying slip planes by visualization method. Generally, slip planes are visualized as flat layers often strengthened by a two-dimensional hydrogen-bonding network within the layers or planes. No hydrogen bonding should exist between these layers to consider them as slip planes. Moreover, one should also check the presence of CH···O type interactions across these planes. Mercury software provides an option for visualization of these weak hydrogen bonding interactions. Hence, caution must be exercised while selecting appropriate solid form based on this crystallographic feature. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  6. Preparation and electrocatalytic property of WC/carbon nanotube composite

    International Nuclear Information System (INIS)

    Li Guohua; Ma Chunan; Tang Junyan; Sheng Jiangfeng

    2007-01-01

    Tungsten carbide/carbon nanotube composite was prepared by surface decoration and in situ reduction-carbonization. The samples were characterized by XRD, SEM, EDS, TEM, HRTEM and BET, respectively. The XRD results show that the sample is composed of carbon nanotube, tungsten carbide and tungsten oxide. The EDS results show that the distribution of tungsten oxide is consistent with that of tungsten carbide. SEM, TEM and HRTEM results show that the tungsten carbide nanoparticle with irregular granule grows on the outside surface of carbon nanotube homogenously. The electrocatalytic activity of the sample for p-nitrophenol reduction was tested by a powder microelectrode in a basic solution. The results show that the electrocatalytic activity of the sample is higher than that of granular tungsten carbide, hollow globe tungsten carbide with mesoporosity and carbon nanotube purified. The improvement of the electrocatalytic activity of the sample can be attributed to its components and composite structure. These results indicate that tungsten carbide/carbon nanotube composite is one of the effective ways to improve the electrocatalytic activity of tungsten carbide

  7. A novel method to produce dry geopolymer cement powder

    Directory of Open Access Journals (Sweden)

    H.A. Abdel-Gawwad

    2016-04-01

    Full Text Available Geopolymer cement is the result of reaction of two materials containing aluminosilicate and concentrated alkaline solution to produce an inorganic polymer binder. The alkali solutions are corrosive and often viscous solutions which are not user friendly, and would be difficult to use for bulk production. This work aims to produce one-mix geopolymer mixed water that could be an alternative to Portland cement by blending with dry activator. Sodium hydroxide (SH was dissolved in water and added to calcium carbonate (CC then dried at 80 °C for 8 h followed by pulverization to a fixed particle size to produce the dry activator consisting of calcium hydroxide (CH, sodium carbonate (SC and pirssonite (P. This increases their commercial availability. The dry activator was blended with granulated blast-furnace slag (GBFS to produce geopolymer cement powder and by addition of water; the geopolymerization process is started. The effect of W/C and SH/CC ratio on the physico-mechanical properties of slag pastes was studied. The results showed that the optimum percent of activator and CC content is 4% SH and 5% CC, by the weight of slag, which give the highest physico-mechanical properties of GBFS. The characterization of the activated slag pastes was carried out using TGA, DTG, IR spectroscopy and SEM techniques.

  8. Activation and micropore structure determination of activated carbon-fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Jagtoyen, M.; Derbyshire, F.; Kimber, G. [Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    1997-09-05

    Rigid, high surface area activated carbon fiber composites have been produced with high permeabilities for environmental applications in gas and water purification. These novel monolithic adsorbents can be produced in single pieces to a given size and shape. The project involves a collaboration between the Oak Ridge National Laboratory (ORNL) and the Center for Applied Energy Research (CAER), University of Kentucky. The carbon fiber composites are produced at the ORNL and activated at the CAER using different methods, with the aims of producing a uniform degree of activation, and of closely controlling pore structure and adsorptive properties. The main focus of the present work has been to find a satisfactory means to uniformly activate large samples of carbon fiber composites and produce controlled pore structures. Several environmental applications have been explored for the activated carbon fiber composites. One of these was to evaluate the activated composites for the separation of CH{sub 4}-CO{sub 2} mixtures, and an apparatus was constructed specifically for this purpose. The composites were further evaluated in the cyclic recovery of volatile organics. The activated carbon fiber composites have also been tested for possible water treatment applications by studying the adsorption of sodium pentachlorophenolate, PCP.

  9. Extending Student Knowledge and Interest through Super-Curricular Activities

    Science.gov (United States)

    Zetie, K. P.

    2018-01-01

    Any teacher of physics is likely to consider super-curricular reading as an important strategy for successful students. However, there are many more ways to extend a student's interest in a subject than reading books, and undirected reading (such as providing a long out of date reading list) is not likely to be as helpful as targeted or directed…

  10. A novel activated carbon for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Haijie [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); Liu, Enhui, E-mail: liuenhui99@sina.com.cn [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); Xiang, Xiaoxia; Huang, Zhengzheng; Tian, Yingying; Wu, Yuhu; Wu, Zhilian; Xie, Hui [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer A novel activated carbon was prepared from phenol-melamine-formaldehyde resin. Black-Right-Pointing-Pointer The carbon has large surface area with microporous, and high heteroatom content. Black-Right-Pointing-Pointer Heteroatom-containing functional groups can improve the pseudo-capacitance. Black-Right-Pointing-Pointer Physical and chemical properties lead to the good electrochemical properties. -- Abstract: A novel activated carbon has been prepared by simple carbonization and activation of phenol-melamine-formaldehyde resin which is synthesized by the condensation polymerization method. The morphology, thermal stability, surface area, elemental composition and surface chemical composition of samples have been investigated by scanning electron microscope, thermogravimetry and differential thermal analysis, Brunauer-Emmett-Teller measurement, elemental analysis and X-ray photoelectron spectroscopy, respectively. Electrochemical properties have been studied by cyclic voltammograms, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements in 6 mol L{sup -1} potassium hydroxide. The activated carbon shows good capacitive behavior and the specific capacitance is up to 210 F g{sup -1}, which indicates that it may be a promising candidate for supercapacitors.

  11. Doped-carbon composites, synthesizing methods and applications of the same

    Science.gov (United States)

    Viswanathan, Tito

    2017-05-09

    A method of synthesizing a doped carbon composite includes preparing a solution having a carbon source material and a heteroatom containing additive, evaporating the solution to yield a plurality of powders, and subjecting the plurality of powders to a heat treatment for a duration of time effective to produce the doped carbon composite.

  12. Micro-milling of spent granular activated carbon for its possible reuse as an adsorbent: Remaining capacity and characteristics.

    Science.gov (United States)

    Pan, Long; Takagi, Yuichi; Matsui, Yoshihiko; Matsushita, Taku; Shirasaki, Nobutaka

    2017-05-01

    We milled granular activated carbons (GACs) that had been used for 0-9 years in water treatment plants and produced carbon particles with different sizes and ages: powdered activated carbons (PAC, median diameter 12-42 μm), superfine PAC (SPAC, 0.9-3.5 μm), and submicron-sized SPAC (SSPAC, 220-290 nm). The fact that SPAC produced from 1-year-old GAC and SSPAC from 2-year-old GAC removed 2-methylisoborneol (MIB) from water with an efficiency similar to that of virgin PAC after a carbon contact time of 30 min suggests that spent GAC could be reused for water treatment after being milled. This potential for reuse was created by increasing the equilibrium adsorption capacity via reduction of the carbon particle size and improving the adsorption kinetics. During long-term (>1 year) use in GAC beds, the volume of pores in the carbon, particularly pores with widths of 0.6-0.9 nm, was greatly reduced. The equilibrium adsorption capacities of the carbon for compounds with molecular sizes in this range could therefore decrease with increasing carbon age. Among these compounds, the decreases of capacities were prominent for hydrophobic compounds, including MIB. For hydrophobic compounds, however, the equilibrium adsorption capacities could be increased with decreasing carbon particle size. The iodine number, among other indices, was best correlated with the equilibrium adsorption capacity of the MIB and would be a good index to assess the remaining MIB adsorption capacity of spent carbon. Spent GAC can possibly be reused as SPAC or SSPAC if its iodine number is ≥ 600 mg/g. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Measurement of carbon thermodynamic activity in sodium

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, F A; Zagorulko, Yu I; Kovalev, Yu P; Alekseev, V V [Institute of Physics and Power Engineering, Obninsk (USSR)

    1980-05-01

    The report presents the brief outline on system of carbon activity detecting system in sodium (SCD), operating on the carbon-permeable membrane, of the methods and the results of testing it under the experimental circulating loop conditions. The results of carbon activity sensor calibration with the use of equilibrium samples of XI8H9, Fe -8Ni, Fe -12Mn materials are listed. The behaviour of carbon activity sensor signals in sodium under various transitional conditions and hydrodynamic perturbation in the circulating loop, containing carbon bearing impurities in the sodium flow and their deposits on the surfaces flushed by sodium, are described. (author)

  14. Method of making improved gas storage carbon with enhanced thermal conductivity

    Science.gov (United States)

    Burchell, Timothy D [Oak Ridge, TN; Rogers, Michael R [Knoxville, TN

    2002-11-05

    A method of making an adsorbent carbon fiber based monolith having improved methane gas storage capabilities is disclosed. Additionally, the monolithic nature of the storage carbon allows it to exhibit greater thermal conductivity than conventional granular activated carbon or powdered activated carbon storage beds. The storage of methane gas is achieved through the process of physical adsorption in the micropores that are developed in the structure of the adsorbent monolith. The disclosed monolith is capable of storing greater than 150 V/V of methane [i.e., >150 STP (101.325 KPa, 298K) volumes of methane per unit volume of storage vessel internal volume] at a pressure of 3.5 MPa (500 psi).

  15. New automated pellet/powder assay system

    International Nuclear Information System (INIS)

    Olsen, R.N.

    1975-01-01

    This paper discusses an automated, high precision, pellet/ powder assay system. The system is an active assay system using a small isotopic neutron source and a coincidence detection system. The handling of the pellet powder samples has been automated and a programmable calculator has been integrated into the system to provide control and data analysis. The versatile system can assay uranium or plutonium in either active or passive modes

  16. Active Thermography for the Detection of Defects in Powder Metallurgy Compacts

    International Nuclear Information System (INIS)

    Benzerrouk, Souheil; Ludwig, Reinhold; Apelian, Diran

    2007-01-01

    Active thermography is an established NDE technique that has become the method of choice in many industrial applications which require non-contact access to the parts under test. Unfortunately, when conducting on-line infrared (IR) inspection of powder metallic compacts, complications can arise due the generally low emissivity of metals and the thermally noisy environment typically encountered in manufacturing plants. In this paper we present results of an investigation that explores the suitability of active IR imaging of powder metallurgy compacts for the detection of surface and sub-surface defects in the pre-sinter state and in an on-line manufacturing setting to ensure complete quality assurance. Additional off-line tests can be carried out for statistical quality analyses. In this research, the IR imaging of sub-surface defects is based on a transient instrumentation approach that relies on an electric control system which synchronizes and monitors the thermal response due to an electrically generated heat source. Preliminary testing reveals that this newly developed pulsed thermography system can be employed for the detection of subsurface defects in green-state parts. Practical measurements agree well with theoretical predictions. The inspection approach being developed can be used for the testing of green-state compacts as they exit the compaction press at speeds of up to 1,000 parts per hour

  17. Preparation of U3O8 powder for MTR type fuel from ammonium uranyl carbonate

    International Nuclear Information System (INIS)

    Marcondes, G.H.; Riella, H.G.

    1990-08-01

    In this paper it is described the research done at IPEN-CNEN/SP on the preparation of U 3 O 8 powder from calcination of the AUC, with appropriate characteristics to be used as dispersoid for MTR type fuel. The calcination in air of the AUC leads a U 3 O 8 powder that is further processed to obtain a powder with density and particle size as especifications. The important process parameters are here discussed with the variation AUC calcination temperature and sintering time of the U 3 O 8 powder. (author) [pt

  18. Performance evaluation of carbon nanotube enhanced membranes for SWRO pretreatment application

    KAUST Repository

    Lee, Jieun; Jeong, Sanghyun; Naidu, Gayathri; Ye, Yun; Chen, Vicki; Liu, Zongwen; Vigneswaran, Saravanamuthu

    2016-01-01

    organic matter improved to 66% with fewer amounts of powder activated carbon (PAC) (0.5 g/L) in MWCNT membrane filtration maintaining a high permeate flux of 600 LMH/bar. It was due to the increased porosity (84.5%) and hydrophilicity (52

  19. Study on Quality Aggregate Construction Powder

    International Nuclear Information System (INIS)

    Myat Ko; Kyaw Naing; Thazin Lwin; Khin Mar Tun

    2008-03-01

    This research work deals with a view to promote cement replacement materials i-e aggregate construction powder, also known as building powder or construction powder . It has been used as lime substituent in construction work in Myanmar since 1990's. It is mixed with other construction materials such as cement, sand, etc. and used in plastering, tiling, arranging bricks and smoothing the face of the buildings.This work also deals with some aspects in physical properties of four different aggregate construction powder samples such as Moe Hein, Man Thiri, Shwe Taung and Kyauk Sue. In addition, these four different samples were characterized by using spectroscopic methods such as ED-XRF, AAS, FT-IR and XRD. In support of the finding by the analytical assays of Moe Hein aggregate construction powder, it indicated the percent composition of the presence of SiO2 12.13%, Al2O3 7.40%, Fe2O3 0.94%, CaO 41.00%,MgO 1.50% total sulphur 1.15%, chloride 1.49%, carbonate 43.63% and sulphate 3.44%. The analytical assays of Sin Min cement, Kyant cement, brick powder and pozzolan were also carried out in this research work. The mixing between various ratios of Moe Hein and Kyant cement as well as Sin Min II cement were done and their mechanical strengths such as setting time, tensile strength and compressive strength of each sample were studied. The quality of mixing ratio 50:50 of Moe Hein and Kyant cement was found to be comparable to the ASTM standard type II Protland cement which is for general use.

  20. Algae-Based Carbon Sequestration

    Science.gov (United States)

    Haoyang, Cai

    2018-03-01

    Our civilization is facing a series of environmental problems, including global warming and climate change, which are caused by the accumulation of green house gases in the atmosphere. This article will briefly analyze the current global warming problem and propose a method that we apply algae cultivation to absorb carbon and use shellfish to sequestrate it. Despite the importance of decreasing CO2 emissions or developing carbon-free energy sources, carbon sequestration should be a key issue, since the amount of carbon dioxide that already exists in the atmosphere is great enough to cause global warming. Algae cultivation would be a good choice because they have high metabolism rates and provides shellfish with abundant food that contains carbon. Shellfish’s shells, which are difficult to be decomposed, are reliable storage of carbon, compared to dead organisms like trees and algae. The amount of carbon that can be sequestrated by shellfish is considerable. However, the sequestrating rate of algae and shellfish is not high enough to affect the global climate. Research on algae and shellfish cultivation, including gene technology that aims to create “super plants” and “super shellfish”, is decisive to the solution. Perhaps the baton of history will shift to gene technology, from nuclear physics that has lost appropriate international environment after the end of the Cold War. Gene technology is vital to human survival.

  1. Low Impedance Carbon Adhesive Electrodes with Long Shelf Life.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Reyes, Bersaín A; Burnham, Ken; Pennace, John; Chon, Ki H

    2015-10-01

    A novel electrocardiogram (ECG) electrode film is developed by mixing carbon black powder and a quaternary salt with a visco-elastic polymeric adhesive. Unlike traditional wet gel-based electrodes, carbon/salt/adhesive (CSA) electrodes should theoretically have an infinite shelf life as they do not dehydrate even after a prolonged period of storage. The CSA electrodes are electrically activated for use through the process of electrophoresis. Specifically, the activation procedure involves sending a high voltage and current through the electrode, which results in significant reduction of impedance so that high fidelity ECG signals can be obtained. Using the activation procedure, the ideal concentration of carbon black powder in the mixture with the adhesive was examined. It was determined that the optimum concentration of carbon black which minimized post-activation impedance was 10%. Once the optimal carbon black powder concentration was determined, extensive signal analysis was performed to compare the performance of the CSA electrodes to the standard silver-silver chloride (Ag/AgCl) electrodes. As a part of data analysis, electrode-skin contact impedance of the CSA was measured and compared to the standard Ag/AgCl electrodes; we found consistently lower impedance for CSA electrodes. For quantitative data analysis, we simultaneously collected ECG data with CSA and Ag/AgCl electrodes from 17 healthy subjects. Heart rate variability (HRV) indices and ECG morphological waveforms were calculated to compare CSA and Ag/AgCl electrodes. Non-significant differences for most of the HRV indices between CSA and Ag/AgCl electrodes were found. Of the morphological waveform metrics consisting of R-wave peak amplitude, ST-segment elevation and QT interval, only the first index was found to be significantly different between the two media. The response of CSA electrodes to motion artifacts was also tested, and we found in general no difference in the quality of the ECG signal

  2. Behaviour of waterborne radon in activated carbon filters

    International Nuclear Information System (INIS)

    Haberer, K.; Akkermann-Kubillus, A.

    1999-01-01

    To investigate the behaviour of radon in adsorption/desorption processes in filter systems with different activated carbon types, measurements were focused on adsorption capacity, adsorption velocity, retain capability, interaction with ions (poisoning of active centers) and adsorption of radon daughters. Various activated carbon types derived from hard coal, brown coal, peat and wood, were used in adsorption tests runs with activated carbons which are frequently applied in water treatment facilities. In laboratory tests, water facility filter conditions were simulated using pilot plant columns filled with different carbon types. Finally, a small scale laboratory column was installed at a natural water source with elevated activity. Long-time filter runs were conducted under varying flow rates and with different amounts of the in waterworks wide-spread used activated carbon F-300. The main results observed were: 1. The amount of radioactivity adsorbed depends upon the type of carbon, its granular size and the contact time between the activated carbon and water. The decontamination capacity was between 19% and 94. 2. The DOC-levels of water influences the adsorbable radioactivity due to the poisoning of the active centres of the carbon. The adsorption velocity decreased down to 15%. 3. The maximum decontamination rate of the water under waterworks conditions was 60%. (orig.) [de

  3. Frames in super Hilbert modules

    Directory of Open Access Journals (Sweden)

    Mehdi Rashidi-Kouchi

    2018-01-01

    Full Text Available In this paper, we define super Hilbert module and investigate frames in this space. Super Hilbert modules are  generalization of super Hilbert spaces in Hilbert C*-module setting. Also, we define frames in a super Hilbert module and characterize them by using of the concept of g-frames in a Hilbert C*-module. Finally, disjoint frames in Hilbert C*-modules are introduced and investigated.

  4. Rapid synthesis of graphitic carbon nitride powders by metathesis reaction between CaCN{sub 2} and C{sub 2}Cl{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Pang Linlin [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China); Carbon Fiber Engineering Research Center of Shandong Province, Shandong University, Jinan 250061 (China); Bi Jianqiang [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China); Bai Yujun [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China) and Carbon Fiber Engineering Research Center of Shandong Province, Shandong University, Jinan 250061 (China)], E-mail: byj97@126.com; Qi Yongxin [Carbon Fiber Engineering Research Center of Shandong Province, Shandong University, Jinan 250061 (China); Zhu Huiling [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China); Carbon Fiber Engineering Research Center of Shandong Province, Shandong University, Jinan 250061 (China); Wang Chengguo; Wu Jiwei [Carbon Fiber Engineering Research Center of Shandong Province, Shandong University, Jinan 250061 (China); Lu Chengwei [Department of Equipment, Shandong University of Science and Technology, Jinan 250031 (China)

    2008-12-20

    Carbon nitride powders were rapidly synthesized at low temperature via the chemical metathesis reaction between CaCN{sub 2} and C{sub 2}Cl{sub 6}. X-ray diffraction results confirm the formation of crystalline graphitic carbon nitride. Besides the dominant morphology of nanoparticles, flakes, nanorods, hollow and solid spheres can be observed by transmission electron microscopy. The absorption peaks of C-N, C=N and s-triazine rings, as well as the absence of C{identical_to}N peak in the infrared spectra, further verify the formation of graphite-like sp{sup 2}-bonded structure with planar networks. Elemental analysis gives an atomic ratio of N/C around 0.3. X-ray photoelectron spectra exhibit the existence of chemical bonding between C and N.

  5. Quantifying, Assessing, and Mitigating Methane Emissions from Super-emitters in the Oil and Gas Supply Chain

    Science.gov (United States)

    Lyon, David Richard

    Methane emissions from the oil and gas (O&G) supply chain reduce potential climate benefits of natural gas as a replacement for other fossil fuels that emit more carbon dioxide per energy produced. O&G facilities have skewed emission rate distributions with a small fraction of sites contributing the majority of emissions. Knowledge of the identity and cause of these high emission facilities, referred to as super-emitters or fat-tail sources, is critical for reducing supply chain emissions. This dissertation addresses the quantification of super-emitter emissions, assessment of their prevalence and relationship to site characteristics, and mitigation with continuous leak detection systems. Chapter 1 summarizes the state of the knowledge of O&G methane emissions. Chapter 2 constructs a spatially-resolved emission inventory to estimate total and O&G methane emissions in the Barnett Shale as part of a coordinated research campaign using multiple top-down and bottom-up methods to quantify emissions. The emission inventory accounts for super-emitters with two-phase Monte Carlo simulations that combine site measurements collected with two approaches: unbiased sampling and targeted sampling of super-emitters. More comprehensive activity data and the inclusion of super-emitters, which account for 19% of O&G emissions, produces a emission inventory that is not statistically different than top-down regional emission estimates. Chapter 3 describes a helicopter-based survey of over 8,000 well pads in seven basins with infrared optical gas imaging to assess high emission sources. Four percent of sites are observed to have high emissions with over 90% of observed sources from tanks. The occurrence of high emissions is weakly correlated to site parameters and the best statistical model explains only 14% of variance, which demonstrates that the occurrence of super-emitters is primarily stochastic. Chapter 4 presents a Gaussian dispersion model for optimizing the placement of

  6. ACTIVATED CARBON (CHARCOAL OBTAINING . APPLICATION

    Directory of Open Access Journals (Sweden)

    Florin CIOFU

    2015-05-01

    Full Text Available The activated carbon is a microporous sorbent with a very large adsorption area that can reach in some cases even 1500sqm / gram. Activated carbon is produced from any organic material with high carbon content: coal, wood, peat or moor coal, coconut shells. The granular activated charcoal is most commonly produced by grinding the raw material, adding a suitable binder to provide the desired hardness and shape. Enabling coal is a complete process through which the raw material is fully exposed to temperatures between 600-900 degrees C, in the absence of oxygen, usually in a domestic atmosphere as gases such as nitrogen or argon; as material that results from this process is exposed in an atmosphere of oxygen and steam at a temperature in the interval from 600 - 1200 degrees C.

  7. Synthesis, Characterization, and Photocatalytic Properties of Bamboo Charcoal/TiO2 Composites Using Four Sizes Powder

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2018-04-01

    Full Text Available Visible-light-active bamboo biochar/TiO2 composites were fabricated by the calcination method using C16H36O4Ti as the titanium source and bamboo powder with different sizes as the carbon source. The TiO2 nanoparticles were observed to disperse onto the surface of bamboo biochar fiber. The sizes of the bamboo powder played an important role in the microstructures and the properties of bamboo biochar/TiO2 composites. The bamboo biochar/TiO2 composites displayed the photocatalytic activities both under visible light irradiation and UV irradiation. The adsorption isotherms better fitted Freundlich isotherm models and the photodegradation reactions followed pseudo-first-order kinetics. Bamboo charcoal/TiO2 composites exhibited high stability after up to four cycles. This research could pave the way for high-value applications of biomass in the environmental field.

  8. Super-low dose endotoxin pre-conditioning exacerbates sepsis mortality.

    Science.gov (United States)

    Chen, Keqiang; Geng, Shuo; Yuan, Ruoxi; Diao, Na; Upchurch, Zachary; Li, Liwu

    2015-04-01

    Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditionings with super-low or low dose endotoxin lipopolysaccharide (LPS) cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP). This is in opposite to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET) in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a novel mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

  9. Super-low Dose Endotoxin Pre-conditioning Exacerbates Sepsis Mortality

    Directory of Open Access Journals (Sweden)

    Keqiang Chen

    2015-04-01

    Full Text Available Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditioning with super-low or low dose endotoxin lipopolysaccharide (LPS cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP. This is in contrast to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

  10. Impact of salinity and dispersed oil on adsorption of dissolved aromatic hydrocarbons by activated carbon and organoclay

    Energy Technology Data Exchange (ETDEWEB)

    Younker, Jessica M.; Walsh, Margaret E., E-mail: mwalsh2@dal.ca

    2015-12-15

    Highlights: • Powdered activated carbon (PAC) outperformed organoclay for dissolved aromatics removal • Dispersed oil reduced the adsorption capacity of PAC but not organoclay • Salinity did not affect phenol or naphthalene removal by PAC or BTMA-organoclay • Commercial organoclay had reduced adsorption capacity in saline water due to aggregation • PAC performed better in single solute systems than multi-solute systems - Abstract: Adsorption capacity of phenol and naphthalene by powdered activated carbon (PAC), a commercial organoclay (OC) and a lab synthesized organoclay (BTMA) was studied using batch adsorption experiments under variable feed water quality conditions including single- and multi- solute conditions, fresh water, saline water and oily-and-saline water. Increasing salinity levels was found to reduce adsorption capacity of OC, likely due to destabilization, aggregation and subsequent removal of organoclay from the water column, but did not negatively impact adsorption capacity of PAC or BTMA. Increased dispersed oil concentrations were found to reduce the surface area of all adsorbents. This decreased the adsorption capacity of PAC for both phenol and naphthalene, and reduced BTMA adsorption of phenol, but did not negatively affect naphthalene removals by either organoclay. The presence of naphthalene as a co-solute significantly reduced phenol adsorption by PAC, but had no impact on organoclay adsorption. These results indicated that adsorption by PAC occurred via a surface adsorption mechanism, while organoclay adsorption occurred by hydrophobic or pi electron interactions. In general, PAC was more sensitive to changes in water quality than either of the organoclays evaluated in this study. However, PAC exhibited a higher adsorption capacity for phenol and naphthalene compared to both organoclays even in adverse water quality conditions.

  11. Impact of salinity and dispersed oil on adsorption of dissolved aromatic hydrocarbons by activated carbon and organoclay

    International Nuclear Information System (INIS)

    Younker, Jessica M.; Walsh, Margaret E.

    2015-01-01

    Highlights: • Powdered activated carbon (PAC) outperformed organoclay for dissolved aromatics removal • Dispersed oil reduced the adsorption capacity of PAC but not organoclay • Salinity did not affect phenol or naphthalene removal by PAC or BTMA-organoclay • Commercial organoclay had reduced adsorption capacity in saline water due to aggregation • PAC performed better in single solute systems than multi-solute systems - Abstract: Adsorption capacity of phenol and naphthalene by powdered activated carbon (PAC), a commercial organoclay (OC) and a lab synthesized organoclay (BTMA) was studied using batch adsorption experiments under variable feed water quality conditions including single- and multi- solute conditions, fresh water, saline water and oily-and-saline water. Increasing salinity levels was found to reduce adsorption capacity of OC, likely due to destabilization, aggregation and subsequent removal of organoclay from the water column, but did not negatively impact adsorption capacity of PAC or BTMA. Increased dispersed oil concentrations were found to reduce the surface area of all adsorbents. This decreased the adsorption capacity of PAC for both phenol and naphthalene, and reduced BTMA adsorption of phenol, but did not negatively affect naphthalene removals by either organoclay. The presence of naphthalene as a co-solute significantly reduced phenol adsorption by PAC, but had no impact on organoclay adsorption. These results indicated that adsorption by PAC occurred via a surface adsorption mechanism, while organoclay adsorption occurred by hydrophobic or pi electron interactions. In general, PAC was more sensitive to changes in water quality than either of the organoclays evaluated in this study. However, PAC exhibited a higher adsorption capacity for phenol and naphthalene compared to both organoclays even in adverse water quality conditions.

  12. Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon

    Science.gov (United States)

    Abdullah, N.; Rinaldi, A.; Muhammad, I. S.; Hamid, S. B. Abd.; Su, D. S.; Schlogl, R.

    2009-06-01

    Carbon-carbon composite of activated carbon and carbon nanofibers have been synthesized by growing Carbon nanofiber (CNF) on Palm shell-based Activated carbon (AC) with Ni catalyst. The composites are in an agglomerated shape due to the entanglement of the defective CNF between the AC particles forming a macroscopic body. The macroscopic size will allow the composite to be used as a stabile catalyst support and liquid adsorbent. The preparation of CNT/AC nanocarbon was initiated by pre-treating the activated carbon with nitric acid, followed by impregnation of 1 wt% loading of nickel (II) nitrate solutions in acetone. The catalyst precursor was calcined and reduced at 300° C for an hour in each step. The catalytic growth of nanocarbon in C2H4/H2 was carried out at temperature of 550° C for 2 hrs with different rotating angle in the fluidization system. SEM and N2 isotherms show the level of agglomeration which is a function of growth density and fluidization of the system. The effect of fluidization by rotating the reactor during growth with different speed give a significant impact on the agglomeration of the final CNF/AC composite and thus the amount of CNFs produced. The macrostructure body produced in this work of CNF/AC composite will have advantages in the adsorbent and catalyst support application, due to the mechanical and chemical properties of the material.

  13. In-duct removal of mercury from coal-fired power plant flue gas by activated carbon: assessment of entrained flow versus wall surface contributions

    Energy Technology Data Exchange (ETDEWEB)

    Scala, F.; Chirone, R.; Lancia, A. [CNR, Naples (Italy). Institute for Research on Combustion

    2008-12-15

    In-duct mercury capture efficiency by activated carbon from coal-combustion flue gas was investigated. To this end, elemental mercury capture experiments were conducted at 100 C in a purposely designed 65-mm ID labscale pyrex apparatus operated as an entrained flow reactor. Gas residence times were varied between 0.7 and 2.0 s. Commercial-powdered activated carbon was continuously injected in the reactor and both mercury concentration and carbon elutriation rate were followed at the outlet. Transient mercury concentration profiles at the outlet showed that steady-state conditions were reached in a time interval of 15-20 min, much longer than the gas residence time in the reactor. Results indicate that the influence of the walls is non-negligible in determining the residence time of fine carbon particles in the adsorption zone, because of surface deposition and/or the establishment of a fluid-dynamic boundary layer near the walls. Total mercury capture efficiencies of 20-50% were obtained with carbon injection rates in the range 0.07-0.25 g/min. However, only a fraction of this capture was attributable to free-flowing carbon particles, a significant contribution coming from activated carbon staying near the reactor walls. Entrained bed experiments at lab-scale conditions are probably not properly representative of full-scale conditions, where the influence of wall interactions is lower. Moreover, previously reported entrained flow lab-scale mercury capture data should be reconsidered by taking into account the influence of particle-wall interactions.

  14. Behaviour of natural radionuclides on activated carbon filter

    International Nuclear Information System (INIS)

    Haberer, K.; Akkermann-Kubillus, A.; Dahlheimer, A.

    1998-01-01

    To investigate the behaviour of radon in adsorption/desorption processes at filter systems based on different activated carbon types, measurements were focused on adsorption capacity, adsorption velocity, retain capability, interaction with ions (poisoning of active centers) and adsorption of radon daughters. Various activated carbon types derived from hard coal, brown coal, peat and wood, were used in adsorption tests runs with activated carbons which are applied in water treatment facilities. In laboratory tests, water facility filter conditions were simulated using pilot plant columns filled with different carbon types. A small scale laboratory column was installed at a natural water source with elevated activity. Tests runs were conducted under varying flow rates and with different amounts of carbon. A full-scale waterworks filter system operated for 6 months was investigated for radon decay products adsorbed on the carbon. The main results observed were: 1. The amount of radioactivity adsorbed depends upon the type of carbon, its granular size and the contact time between the activated carbon and water. The decontamination capacity was between 19% and 94%. 2. The DOC-levels of water influences the adsorbable radioactivity due to the poisoning of the active centers of the carbon. The adsorption velocity decreased down to 15%. 3. The maximum decontamination rate of the water under waterworks conditions was 60%. (orig.) [de

  15. MODEL SPECTRA OF THE FIRST POTENTIALLY HABITABLE SUPER-EARTH-Gl581d

    International Nuclear Information System (INIS)

    Kaltenegger, Lisa; Segura, AntIgona; Mohanty, Subhanjoy

    2011-01-01

    Gl581d has a minimum mass of 7 M Earth and is the first detected potentially habitable rocky Super-Earth. Our models confirm that a habitable atmosphere can exist on Gl581d. We derive spectroscopic features for atmospheres assuming an Earth-like composition for this planet, from high-oxygen atmosphere analogous to Earth's to high-CO 2 atmospheres with and without biotic oxygen concentrations. We find that a minimum CO 2 partial pressure of about 7 bar, in an atmosphere with a total surface pressure of 7.6 bar, is needed to maintain a mean surface temperature above freezing on Gl581d. We model transmission and emergent synthetic spectra from 0.4 μm to 40 μm and show where indicators of biological activities in such a planet's atmosphere could be observed by future ground- and space-based telescopes. The model we present here only represents one possible nature-an Earth-like composition-of a planet like Gl581d in a wide parameter space. Future observations of atmospheric features can be used to examine if our concept of habitability and its dependence on the carbonate-silicate cycle is correct, and assess whether Gl581d is indeed a habitable Super-Earth.

  16. The influence of different diffusion pattern to the sub- and super-critical fluid flow in brown coal

    Science.gov (United States)

    Peng, Peihuo

    2018-03-01

    Sub- and super-critical CO2 flowing in nanoscale pores are recently becoming of great interest due to that it is closely related to many engineering applications, such as geological burial and sequestration of carbon dioxide, Enhanced Coal Bed Methane recovery ( ECBM), super-critical CO2 fracturing and so on. Gas flow in nanopores cannot be described simply by the Darcy equation. Different diffusion pattern such as Fick diffusion, Knudsen diffusion, transitional diffusion and slip flow at the solid matrix separate the seepage behaviour from Darcy-type flow. According to the principle of different diffusion pattern, the flow of sub- and super-critical CO2 in brown coal was simulated by numerical method, and the results were compared with the experimental results to explore the contribution of different diffusion pattern and swelling effect in sub- and super-critical CO2 flow in nanoscale pores.

  17. Production of activated carbons from almond shell

    Energy Technology Data Exchange (ETDEWEB)

    Nabais, Joao M. Valente; Laginhas, Carlos Eduardo C.; Carrott, P.J.M.; Ribeiro Carrott, M.M.L. [Evora Univ. (Portugal). Centro de Quimica de Evora

    2011-02-15

    The production of activated carbons from almond shell, using physical activation by CO{sub 2} is reported in this work. The used method has produced activated carbons with apparent BET surface areas and micropore volume as high as 1138 m{sup 2} g{sup -1} and 0.49 cm{sup 3} g{sup -1}, respectively. The activated carbons produced have essentially primary micropores and only a small volume of wider micropores. By FTIR analysis it was possible to identify, in the surface of the activated carbons, several functional groups, namely hydroxyls (free and phenol), ethers, esters, lactones, pyrones and Si-H bonds. By the analysis of the XRD patterns it was possible to calculate the microcrystallites dimensions with height between 1.178 and 1.881 nm and width between 3.106 and 5.917 nm. From the XRD it was also possible to identify the presence of traces of inorganic heteroatoms such as Si, Pb, K, Fe and P. All activated carbons showed basic characteristics with point of zero charge between 9.42 and 10.43. (author)

  18. Analytical SuperSTEM for extraterrestrial materials research

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J P; Dai, Z R

    2009-09-08

    Electron-beam studies of extraterrestrial materials with significantly improved spatial resolution, energy resolution and sensitivity are enabled using a 300 keV SuperSTEM scanning transmission electron microscope with a monochromator and two spherical aberration correctors. The improved technical capabilities enable analyses previously not possible. Mineral structures can be directly imaged and analyzed with single-atomic-column resolution, liquids and implanted gases can be detected, and UV-VIS optical properties can be measured. Detection limits for minor/trace elements in thin (<100 nm thick) specimens are improved such that quantitative measurements of some extend to the sub-500 ppm level. Electron energy-loss spectroscopy (EELS) can be carried out with 0.10-0.20 eV energy resolution and atomic-scale spatial resolution such that variations in oxidation state from one atomic column to another can be detected. Petrographic mapping is extended down to the atomic scale using energy-dispersive x-ray spectroscopy (EDS) and energy-filtered transmission electron microscopy (EFTEM) imaging. Technical capabilities and examples of the applications of SuperSTEM to extraterrestrial materials are presented, including the UV spectral properties and organic carbon K-edge fine structure of carbonaceous matter in interplanetary dust particles (IDPs), x-ray elemental maps showing the nanometer-scale distribution of carbon within GEMS (glass with embedded metal and sulfides), the first detection and quantification of trace Ti in GEMS using EDS, and detection of molecular H{sub 2}O in vesicles and implanted H{sub 2} and He in irradiated mineral and glass grains.

  19. Biogas pre-upgrading by adsorption of trace compounds onto granular activated carbons and an activated carbon fiber-cloth.

    Science.gov (United States)

    Boulinguiez, B; Le Cloirec, P

    2009-01-01

    The study assesses the adsorption onto activated carbon materials of selected volatile organic compounds -VOCs- (dichloromethane, 2-propanol, toluene, siloxane D4) in a biogas matrix composed of methane and carbon dioxide (55:45 v/v). Three different adsorbents are tested, two of them are granular activated carbon (GAC), and the last is an activated carbon fiber-cloth (ACFC). The adsorption isotherm data are fitted by different models by nonlinear regression. The Langmuir-Freundlich model appears to be the adequate one to describe the adsorption phenomena independently of the VOC considered or the adsorbent. The adsorbents present attractive adsorption capacity of the undesirable compounds in biogas atmosphere though the maximum adsorption capacities for a VOC are quite different from each other. The adsorption kinetics are characterized through three coefficients: the initial adsorption coefficient, the external film mass transfer coefficient and the internal diffusion coefficient of Weber. The ACFC demonstrates advanced kinetic yields compared to the granular activated carbon materials whatever VOC is considered. Therefore, pre-upgrading of biogas produced from wastewater sludge or co-digestion system by adsorption onto activated carbon appears worth investigating. Especially with ACFC material that presents correct adsorption capacities toward VOCs and concrete regeneration process opportunity to realize such process.

  20. Preparation and characterisation of activated carbon

    International Nuclear Information System (INIS)

    Badri bin Muhammad; Karen binti Badri; Mohd Zobir bin Hussein; Zulkarnain bin Zainal; W.M. Daud bin W Yunus; Ramli bin Ibrahim

    1994-01-01

    Activated carbon was prepared from Agricultural wastes, such as coconut shell, Palm oil Shell and mangrove trunk by destructive distillation under vakuum. Chemical and Physical properties of the activated carbon were studied and some potentially useful application in the fields of chemistry was also carried out

  1. SuperCDMS Underground Detector Fabrication Facility

    Energy Technology Data Exchange (ETDEWEB)

    Platt, M.; Mahapatra, R.; Bunker, Raymond A.; Orrell, John L.

    2018-03-01

    The SuperCDMS SNOLAB dark matter experiment processes Ge and Si crystals into fully tested phonon and ionization detectors at surface fabrication and test facilities. If not mitigated, it is anticipated that trace-level production of radioisotopes in the crystals due to exposure to cosmic rays at (or above) sea level will result in the dominant source of background events in future dark matter searches using the current SuperCDMS detector technology. Fabrication and testing of detectors in underground facilities shielded from cosmic radiation is one way to directly reduce production of trace levels of radioisotopes, thereby improving experimental sensitivity for the discovery of dark matter beyond the level of the current experiment. In this report, we investigate the cost and feasibility to establish a complete detector fabrication processing chain in an underground location to mitigate cosmogenic activation of the Ge and Si detector substrates. For a specific and concrete evaluation, we explore options for such a facility located at SNOLAB, an underground laboratory in Sudbury, Canada hosting the current and future experimental phases of SuperCDMS.

  2. Carbon nanotubes purification constrains due to large Fe–Ni/Al2O3 ...

    Indian Academy of Sciences (India)

    The phenomenon is due to liquid-like behaviour of the active phase at reaction temperature (700 ◦C) which is higher than both .... purified carbon nanotubes were washed with distilled water .... easy catalyst active phase extraction, followed by “tip-mode” .... racterization of porous solids and powders: surface area, pore.

  3. Production of activated carbon from peanut hill using phosphoric acid and microwave activation

    Directory of Open Access Journals (Sweden)

    Weerawat Clowutimon

    2015-06-01

    Full Text Available The optimum conditions for preparing activated carbon from peanut hulls by phosphoric acid and microwave activation were studied. Factors investigated in this study were temperature of carbonization at 300, 350, 400 and 450๐ C, and time of carbonization at 30, 60 and 90 minutes. The optimum yield was observed that carbonization temperature of 400๐ C and time at 60 minutes, respectively. The yield of charcoal was 39% and the f ix carbon was 69%. Then the charcoal was activated by phosphoric acid and microwave irradiation, respectively. The effect of the weight per volume ratios of charcoal to activating acid (1:1, 1:2 and 2:1(W/V, microwave power at (activated 300, 500 and 700 watts, and activated time (30, 60 and 90 seconds were studied. The results showed that the optimum conditions for activating peanut charcoal were 1:2 (W/V charcoal per activating acid, microwave power 700 watts for 90 seconds. The results yielding maximum surface area by BET method was 303.1 m2 /g and pore volume was 0.140 cm3 /g. An efficiency of maximum iodine adsorption was 418 mg iodine/g activated carbon. Comparing the adsorption efficiency of non- irradiated and irradiated activated carbon, the efficiency of irradiated activated carbon improved up to 31%, due to its larger surface area and pore volume.

  4. Characteristics of Inconel Powders for Powder-Bed Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Quy Bau Nguyen

    2017-10-01

    Full Text Available In this study, the flow characteristics and behaviors of virgin and recycled Inconel powder for powder-bed additive manufacturing (AM were studied using different powder characterization techniques. The results revealed that the particle size distribution (PSD for the selective laser melting (SLM process is typically in the range from 15 μm to 63 μm. The flow rate of virgin Inconel powder is around 28 s·(50 g−1. In addition, the packing density was found to be 60%. The rheological test results indicate that the virgin powder has reasonably good flowability compared with the recycled powder. The inter-relation between the powder characteristics is discussed herein. A propeller was successfully printed using the powder. The results suggest that Inconel powder is suitable for AM and can be a good reference for researchers who attempt to produce AM powders.

  5. Processing and Properties of Distaloy Sa Sintered Alloys with Boron and Carbon

    Directory of Open Access Journals (Sweden)

    Karwan-Baczewska J.

    2015-04-01

    Full Text Available Prealloyed iron-based powders, manufactured in Höganäs Company, are used in the automotive parts industry. The properties and life time of such sintered parts depend, first of all, on their chemical composition, the production method of the prealloyed powder as well as on the technology of their consolidation and sintering. One of simpler and conventional methods aimed at increasing the density in sintered products is the process of activated sintering, performed, for example, by adding boron as elementary boron powder. Under this research project obtained were novel sintered materials, based on prealloyed and diffusion bonded powder, type: Distaloy SA, with the following chemical composition: Fe-1.75% Ni-1.5%Cu- 0.5%Mo with carbon (0.55%; 0.75% and boron (0.2%, 0.4% and 0.6%. Distaloy SA samples alloyed with carbon and boron were manufactured by mixing powders in a Turbula mixer, then compressed using a hydraulic press under a pressure of 600 MPa and sintered in a tube furnace at 1473 K, for a 60 minute time, in the hydrogen atmosphere. After the sintering process, there were performed density and porosity measurements as well as hardness tests and mechanical properties were carried out, too. Eventually, analyzed was the effect of boron upon density, hardness and mechanical properties of novel sintered construction parts made from Distaloy SA powder.

  6. Adsorption and desorption of pertechnetate on activated carbon

    International Nuclear Information System (INIS)

    Dano, M.; Galambos, M.; Rajec, P.; Viglasova, E.; Krajnak, A.; Novak, I.

    2014-01-01

    High surface area, a microporous structure, and a high degree of surface reactivity make activated carbons versatile adsorbents, particularly effective in the adsorption of radionuclides from aqueous solutions. The most important property of activated carbon, the property that determines its usage, is the pore structure. The total number of pores, their shape and size determine the adsorption capacity and even the dynamic adsorption rate of the activated carbon. This report is dedicated to sorption properties of new activated carbon sorbents. (authors)

  7. Volumetric and superficial characterization of carbon activated

    International Nuclear Information System (INIS)

    Carrera G, L.M.; Garcia S, I.; Jimenez B, J.; Solache R, M.; Lopez M, B.; Bulbulian G, S.; Olguin G, M.T.

    2000-01-01

    The activated carbon is the resultant material of the calcination process of natural carbonated materials as coconut shells or olive little bones. It is an excellent adsorbent of diluted substances, so much in colloidal form, as in particles form. Those substances are attracted and retained by the carbon surface. In this work is make the volumetric and superficial characterization of activated carbon treated thermically (300 Centigrade) in function of the grain size average. (Author)

  8. THE STUDY OF IMMUNOMODULATORY AND ANTIMICROBIAL ACTIVITY OF SHIITAKE MUSHROOMS POWDER (Lentinus edodes

    Directory of Open Access Journals (Sweden)

    Bobritskaya L.A.

    2013-12-01

    Full Text Available It was found that Shiitake mushroom powder exhibitedimmunomodulatory effects and it could be used in perspective for immunity correction in the complex therapy for the treatment of various infectious and inflammatory diseases. It had moderate antimicrobial activity against aerobic bacteria (Staphylococcus aureus ATCC 26923, Escherichia coli ATCC 25922, Basillus subtilis ATCC 6633, and fungi (Candida albicans ATCC 653/885.

  9. Straightforward fabrication of black nano silica dusting powder for latent fingerprint imaging

    Science.gov (United States)

    Komalasari, Isna; Krismastuti, Fransiska Sri Herwahyu; Elishian, Christine; Handayani, Eka Mardika; Nugraha, Willy Cahya; Ketrin, Rosi

    2017-11-01

    Imaging of latent fingerprint pattern (aka fingermark) is one of the most important and accurate detection methods in forensic investigation because of the characteristic of individual fingerprint. This detection technique relies on the mechanical adherence of fingerprint powder to the moisture and oily component of the skin left on the surface. The particle size of fingerprint powder is one of the critical parameter to obtain excellent fingerprint image. This study develops a simple, cheap and straightforward method to fabricate Nano size black dusting fingerprint powder based on Nano silica and applies the powder to visualize latent fingerprint. The nanostructured silica was prepared from tetraethoxysilane (TEOS) and then modified with Nano carbon, methylene blue and sodium acetate to color the powder. Finally, as a proof-of-principle, the ability of this black Nano silica dusting powder to image latent fingerprint is successfully demonstrated and the results show that this fingerprint powder provides clearer fingerprint pattern compared to the commercial one highlighting the potential application of the nanostructured silica in forensic science.

  10. SAXS study on activated carbons

    International Nuclear Information System (INIS)

    Bota, A.; Heringer, D.; Mihalffy, T.

    1999-01-01

    SAXS fractal analysis of activated carbons is presented. It gives very useful information about the structural changes of the carbon skeleton. From the fact, that the sequence of the activation and the heat treatment affect the fractal behaviours more drastically than the particle size distribution of the structural units, it follows that all changes in the pore and matrix structure may reduce principally to the bonding of the crystallite units. (K.A.)

  11. (Super Variable Costing-Throughput Costing)

    OpenAIRE

    Çakıcı, Cemal

    2006-01-01

    (Super Variable Costing-Throughput Costing) The aim of this study is to explain the super-variable costing method which is a new subject in cost and management accounting and to show it’s working practicly.Shortly, super-variable costing can be defined as a costing method which is use only direct material costs in calculate of product costs and treats all costs except these (direct labor and overhead) as periad costs or operating costs.By using super-variable costing method, product costs ar...

  12. Novel phase of carbon, ferromagnetism, and conversion into diamond

    International Nuclear Information System (INIS)

    Narayan, Jagdish; Bhaumik, Anagh

    2015-01-01

    We report the discovery of a new phase of carbon (referred to as Q-carbon) and address fundamental issues related to direct conversion of carbon into diamond at ambient temperatures and pressures in air without any need for catalyst and presence of hydrogen. The Q-carbon is formed as result of quenching from super undercooled state by using high-power nanosecond laser pulses. We discuss the equilibrium phase diagram (P vs. T) of carbon and show that by rapid quenching kinetics can shift thermodynamic graphite/diamond/liquid carbon triple point from 5000 K/12 GPa to super undercooled carbon at atmospheric pressure in air. It is shown that nanosecond laser heating of diamond-like amorphous carbon on sapphire, glass, and polymer substrates can be confined to melt carbon in a super undercooled state. By quenching the carbon from the super undercooled state, we have created a new state of carbon (Q-carbon) from which nanodiamond, microdiamond, microneedles, and single-crystal thin films are formed depending upon the nucleation and growth times allowed for diamond formation. The Q-carbon quenched from liquid is a new state of solid carbon with a higher mass density than amorphous carbon and a mixture of mostly fourfold sp 3 (75%–85%) with the rest being threefold sp 2 bonded carbon (with distinct entropy). It is expected to have new and improved mechanical hardness, electrical conductivity, chemical, and physical properties, including room-temperature ferromagnetism (RTFM) and enhanced field emission. Here we present interesting results on RTFM, enhanced electrical conductivity and surface potential of Q-carbon to emphasize its unique properties. The Q-carbon exhibits robust bulk ferromagnetism with estimated Curie temperature of about 500 K and saturation magnetization value of 20 emu g −1 . From the Q-carbon, diamond phase is nucleated and a variety of micro- and nanostructures and large-area single-crystal diamond sheets are grown by allowing growth times

  13. MECHANICAL PROPERTIES AND CORROSION PROTECTION OF CARBON STEEL COATED WITH AN EPOXY BASED POWDER COATING CONTAINING MONTMORILONITE FUNCTIONALIZED WITH SILANE

    Directory of Open Access Journals (Sweden)

    Paula Tibola Bertuoli

    2014-06-01

    Full Text Available In the present work the MMT-Na+ clay was functionalized with 3-aminopropyltriethoxysilane (γ-APS and incorporated in a commercial formulation epoxy-based powder coating in a proportion of 8 wt% and applied on 1008 carbon steel panels by electrostatic spray. Adhesion, flexibility, impact and corrosion performance in salt spray chamber tests were performed to evaluate the coatings. The presence of clay did not affect the mechanical properties of the film, however greater subcutaneous migration was assessed after the completion of salt spray testing, which can compromise the use of paints obtained as primers.

  14. Capacitor with a composite carbon foam electrode

    Science.gov (United States)

    Mayer, Steven T.; Pekala, Richard W.; Kaschmitter, James L.

    1999-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid partides being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy.

  15. Synthesis of battery grade reduced silver powder

    International Nuclear Information System (INIS)

    Qadeer, R.; Hameed, M.; Ikram, S.; Munir, A.

    2002-01-01

    Process for production of battery grade reduced silver powder, an active positive material for zinc-silver oxide batteries, having specific characteristics has been optimized and the synthesized reduced silver powder was characterized. Results reveal that the values of bulk density (1.25 0.1 g/cm3) and activity (73.27 %) of synthesized reduced silver powder lies within the recommended range for use as battery material. It has purity ≥ 98% and contains Fe and Cu as traces in the concentration range of 30 5 ppm and 15 7 ppm respectively. Others determined values of surface and pores parameters are: surface area 2.6 .4 m2/g: pore volume 3.10 cm3/g: pore diameter 0.043 mu m and porosity 20%. XRD studies reveal that reduced silver powder has a cubic structure. (author)

  16. Graphene-enabled electron microscopy and correlated super-resolution microscopy of wet cells.

    Science.gov (United States)

    Wojcik, Michal; Hauser, Margaret; Li, Wan; Moon, Seonah; Xu, Ke

    2015-06-11

    The application of electron microscopy to hydrated biological samples has been limited by high-vacuum operating conditions. Traditional methods utilize harsh and laborious sample dehydration procedures, often leading to structural artefacts and creating difficulties for correlating results with high-resolution fluorescence microscopy. Here, we utilize graphene, a single-atom-thick carbon meshwork, as the thinnest possible impermeable and conductive membrane to protect animal cells from vacuum, thus enabling high-resolution electron microscopy of wet and untreated whole cells with exceptional ease. Our approach further allows for facile correlative super-resolution and electron microscopy of wet cells directly on the culturing substrate. In particular, individual cytoskeletal actin filaments are resolved in hydrated samples through electron microscopy and well correlated with super-resolution results.

  17. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    ... through the compaction formulation process and application. Compaction of powder constituents both active ingredient and excipients is examined to ensure consistent and reproducible disintegration and dispersion profiles...

  18. Sintering of B4C powder obtained by a modified carbo-thermal reaction

    International Nuclear Information System (INIS)

    Rocha, R.M.; Kazumi, M.H.; Goncalves, D.P.; Melo, F.C.L.

    2005-01-01

    Boron carbide is one of the hardest materials and a highly refractory material that is of great interest for structural, electronic and nuclear applications. B 4 C is commercially manufactured by the carbo-thermal reduction of a mixture of boron oxide (B 2 O 3 ) in an batch electric arc furnace process. However the carbo-thermal reaction on the stoichiometric starting composition results an excess carbon residue because of the boron loss in the form of B 2 O 2 . Thus, a modified carbo-thermal reaction is applied with an excess B 2 O 3 to compensate the loss and to obtain stoichiometric powders. The aim of this work is to study the sinterability of this powder with the lower carbon residue acting as sintering additive. Pressureless sintering in the temperatures of 1900 deg. C/30 min and 2100 deg. C/30 min in argon atmosphere were applied. The synthesized powders were analysed by XRD and SEM. Density of 94% of theoretical density was achieved for sample prepared with the powder obtained with 50% B 2 O 3 excess synthesized at 1700 deg. C/15 min. (authors)

  19. Research Advances in High-Yielding Cultivation and Physiology of Super Rice

    Directory of Open Access Journals (Sweden)

    Jing FU

    2012-09-01

    Full Text Available In 1996, China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant types. Today, approximately 80 super rice varieties have been released and some of them show high grain yields of 12–21 t/hm2 in field experiments. The main reasons for the high yields of super rice varieties, compared with those of conventional varieties, can be summarized as follows: more spikelets per panicle and larger sink size (number of spikelets per square meter; larger leaf area index, longer duration of green leaf, greater photosynthetic rate, higher lodging resistance, greater dry matter accumulation before the heading stage, greater remobilization of pre-stored carbohydrates from stems and leaves to grains during the grain-filling period; and larger root system and greater root activity. However, there are two main problems in super rice production: poor grain-filling of the later-flowering inferior spikelets (in contrast to earlier-flowering superior spikelets, and low and unstable seed-setting rate. Here, we review recent research advances in the crop physiology of super rice, focusing on biological features, formation of yield components, and population quality. Finally, we suggest further research on crop physiology of super rice.

  20. Electrically tuned super-capacitors

    OpenAIRE

    Chowdhury, Tazima S.; Grebel, Haim

    2015-01-01

    Fast charging and discharging of large amounts of electrical energy make super-capacitors ideal for short-term energy storage [1-5]. In its simplest form, the super-capacitor is an electrolytic capacitor made of an anode and a cathode immersed in an electrolyte. As for an ordinary capacitor, minimizing the charge separation distance and increasing the electrode area increase capacitance. In super-capacitors, charge separation is of nano-meter scale at each of the electrode interface (the Helm...

  1. Example-Based Super-Resolution Fluorescence Microscopy.

    Science.gov (United States)

    Jia, Shu; Han, Boran; Kutz, J Nathan

    2018-04-23

    Capturing biological dynamics with high spatiotemporal resolution demands the advancement in imaging technologies. Super-resolution fluorescence microscopy offers spatial resolution surpassing the diffraction limit to resolve near-molecular-level details. While various strategies have been reported to improve the temporal resolution of super-resolution imaging, all super-resolution techniques are still fundamentally limited by the trade-off associated with the longer image acquisition time that is needed to achieve higher spatial information. Here, we demonstrated an example-based, computational method that aims to obtain super-resolution images using conventional imaging without increasing the imaging time. With a low-resolution image input, the method provides an estimate of its super-resolution image based on an example database that contains super- and low-resolution image pairs of biological structures of interest. The computational imaging of cellular microtubules agrees approximately with the experimental super-resolution STORM results. This new approach may offer potential improvements in temporal resolution for experimental super-resolution fluorescence microscopy and provide a new path for large-data aided biomedical imaging.

  2. Efficacy of undecylenic acid-zinc undecylenate powder in culture positive tinea pedis.

    Science.gov (United States)

    Chretien, J H; Esswein, J G; Sharpe, L M; Kiely, J J; Lyddon, F E

    1980-01-01

    One hundred fifty-one patients with tinea pedis participated in a double-blind study to assess the efficacy and safety of a powder containing undecylenic acid 2% and zinc undecylenate 20% versus a placebo powder. Patients were assigned to apply twice-daily applications of either active powder or placebo for a period of 4 weeks. Trichophyton rubrum or Trichophyton mentagrophytes were isolated from pretreatment cultures of 85 patients. Of these, 88% treated with active powder had negative cultures after 4 weeks compared with 17% of those treated with placebo powder (p less than 0.001). Fungus was identified in potassium hydroxide (KOH) treated skin scrapings of all 151 patients before treatment. Of those treated with active powder, 80% were KOH negative after 4 weeks compared with 49% of those treated with placebow powder (p = 0.001). Erythema and scaling were significantly improved by therapy with active powder, as were subjective evaluations of itching and burning. There were no side-effects or adverse reactions to undecylenic acid and its zinc salt.

  3. Utilization of Cacao Pod Husk (Theobroma cacao l.) as Activated Carbon and Catalyst in Biodiesel Production Process from Waste Cooking Oil

    Science.gov (United States)

    Rachmat, Devita; Johar Mawarani, Lizda; Dewi Risanti, Doty

    2018-01-01

    Cocoa pod husk (Theobroma cacao l.) is a waste from cocoa beans processing. In this research we employ cocoa pod husk as activated carbon to decrease the value of FFA (Free Fatty Acid) in waste cooking oil and as K2CO3 catalyst in biodiesel production process from waste cooking oil. Cocoa pod husk was crusched and grounded into powder that passed thorugh 60 mesh-screen. As activated carbon, cocoa pod husk was firstly carbonized at three variant temperatures i.e 250°C, 300°C and 350°C. The activation process was done using HCl 2M as activator. Based on the results of XRD and FTIR, the carbonization at all variant temperatures does not cause a significant changes in terms of crystallite structure and water content. The pore of activated carbon started to form in sample that was carbonized at 350°C resulting in pore diameter of 5.14644 nm. This result was supported by the fact that the ability of this activated carbon in reducing the FFA of waste cooking oil was the most pronounced one, i.e. up to 86.7% of FFA. It was found that the performance of cocoa pod husk’s activated carbon in reducing FFA is more effective than esterification using H2SO4 which can only decrease 80.8%. On the other hand, the utilization as K2CO3 catalyst was carried out by carbonization at temperature 650°C and extraction using aquadest solvent. The extraction of cocoa pod husk produced 7.067% K2CO3 catalyst. According to RD results the fraction of K2CO3 compound from the green catalysts is the same as the commercial (SAP, 99%) that is ≥ 60%. From the obtained results, the best yield percentage was obtained using K2CO3 catalyst from cacao pod husk extract, i.e. 73-85%. To cope with biodiesel conversion efficiency, a two-step process consisting pretreatment with activated carbon carbonized at 350°C and esterification with K2CO3 from cocoa pod husk catalyst was developed. This two-step process could reach a high conversion of 85%. From the results it was clear that the produced

  4. Reuse performance of granular-activated carbon and activated carbon fiber in catalyzed peroxymonosulfate oxidation.

    Science.gov (United States)

    Yang, Shiying; Li, Lei; Xiao, Tuo; Zhang, Jun; Shao, Xueting

    2017-03-01

    Recently, activated carbon was investigated as an efficient heterogeneous metal-free catalyst to directly activate peroxymonosulfate (PMS) for degradation of organic compounds. In this paper, the reuse performance and the possible deactivation reasons of granular-activated carbon (GAC) and activated carbon fiber (ACF) in PMS activation were investigated. As results indicated, the reusability of GAC, especially in the presence of high PMS dosage, was relatively superior to ACF in catalyzed PMS oxidation of Acid Orange 7 (AO7), which is much more easily adsorbed by ACF than by GAC. Pre-oxidation experiments were studied and it was demonstrated that PMS oxidation on ACF would retard ACF's deactivation to a big extent. After pre-adsorption with AO7, the catalytic ability of both GAC and ACF evidently diminished. However, when methanol was employed to extract the AO7-spent ACF, the catalytic ability could recover quite a bit. GAC and ACF could also effectively catalyze PMS to degrade Reactive Black 5 (RB5), which is very difficult to be adsorbed even by ACF, but both GAC and ACF have poor reuse performance for RB5 degradation. The original organic compounds or intermediate products adsorbed by GAC or ACF would be possibly responsible for the deactivation.

  5. Microwave absorption properties of a wave-absorbing coating employing carbonyl-iron powder and carbon black

    International Nuclear Information System (INIS)

    Liu Lidong; Duan Yuping; Ma Lixin; Liu Shunhua; Yu Zhen

    2010-01-01

    To prevent serious electromagnetic interference, a single-layer wave-absorbing coating employing complex absorbents composed of carbonyl-iron powder (CIP) and carbon black (CB) with epoxy resin as matrix was prepared. The morphologies of CIP and CB were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The electromagnetic parameters of CIP and CB were measured in the frequency range of 2-18 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss (RL) using arch method. The effects of CIP ratio, CB content and thickness on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, CIP or CB content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of CIP or CB in composites.

  6. Microwave absorption properties of a wave-absorbing coating employing carbonyl-iron powder and carbon black

    Science.gov (United States)

    Liu, Lidong; Duan, Yuping; Ma, Lixin; Liu, Shunhua; Yu, Zhen

    2010-11-01

    To prevent serious electromagnetic interference, a single-layer wave-absorbing coating employing complex absorbents composed of carbonyl-iron powder (CIP) and carbon black (CB) with epoxy resin as matrix was prepared. The morphologies of CIP and CB were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The electromagnetic parameters of CIP and CB were measured in the frequency range of 2-18 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss (RL) using arch method. The effects of CIP ratio, CB content and thickness on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, CIP or CB content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of CIP or CB in composites.

  7. The Adsorption Mechanism of Modified Activated Carbon on Phenol

    Directory of Open Access Journals (Sweden)

    Lin J. Q.

    2016-01-01

    Full Text Available Modified activated carbon was prepared by thermal treatment at high temperature under nitrogen flow. The surface properties of the activated carbon were characterized by Boehm titration, BET and point of zero charge determination. The adsorption mechanism of phenol on modified activated carbon was explained and the adsorption capacity of modified activated carbon for phenol when compared to plain activated carbon was evaluated through the analysis of adsorption isotherms, thermodynamic and kinetic properties. Results shows that after modification the surface alkaline property and pHpzc value of the activated carbon increase and the surface oxygen-containing functional groups decrease. The adsorption processes of the plain and modified carbon fit with Langmuir isotherm equation well, and the maximum adsorption capacity increase from 123.46, 111.11, 103.09mg/g to 192.31, 178.57, 163,93mg/g under 15, 25 and 35°C after modification, respectively. Thermodynamic parameters show that the adsorption of phenol on activated carbon is a spontaneously exothermic process of entropy reduction, implying that the adsorption is a physical adsorption. The adsorption of phenol on activated carbon follows the pseudo-second-order kinetics (R2>0.99. The optimum pH of adsorption is 6~8.

  8. Synthesis of Uranium nitride powders using metal uranium powders

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kim, Dong Joo; Oh, Jang Soo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik

    2012-01-01

    Uranium nitride (UN) is a potential fuel material for advanced nuclear reactors because of their high fuel density, high thermal conductivity, high melting temperature, and considerable breeding capability in LWRs. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. The carbothermic reduction has an advantage in the production of fine powders. However it has many drawbacks such as an inevitable engagement of impurities, process burden, and difficulties in reusing of expensive N 15 gas. Manufacturing concerns issued in the carbothermic reduction process can be solved by changing the starting materials from oxide powder to metals. However, in nitriding process of metal, it is difficult to obtain fine nitride powders because metal uranium is usually fabricated in the form of bulk ingots. In this study, a simple reaction method was tested to fabricate uranium nitride powders directly from uranium metal powders. We fabricated uranium metal spherical powder and flake using a centrifugal atomization method. The nitride powders were obtained by thermal treating those metal particles under nitrogen containing gas. We investigated the phase and morphology evolutions of powders during the nitriding process. A phase analysis of nitride powders was also a part of the present work

  9. Handbook of Super 8 Production.

    Science.gov (United States)

    Telzer, Ronnie, Ed.

    This handbook is designed for anyone interested in producing super 8 films at any level of complexity and cost. Separate chapters present detailed discussions of the following topics: super 8 production systems and super 8 shooting and editing systems; budgeting; cinematography and sound recording; preparing to edit; editing; mixing sound tracks;…

  10. The super-resolution debate

    Science.gov (United States)

    Won, Rachel

    2018-05-01

    In the quest for nanoscopy with super-resolution, consensus from the imaging community is that super-resolution is not always needed and that scientists should choose an imaging technique based on their specific application.

  11. Quality of poultry litter-derived granular activated carbon.

    Science.gov (United States)

    Qiu, Guannan; Guo, Mingxin

    2010-01-01

    Utilization of poultry litter as a source material for generating activated carbon is a value-added and environmentally beneficial approach to recycling organic waste. In this study, the overall quality of poultry litter-derived granular activated carbon was systematically evaluated based on its various physical and chemical properties. Granular activated carbon generated from pelletized poultry litter following a typical steam-activation procedure possessed numerous micropores in the matrix. The product exhibited a mean particle diameter of 2.59 mm, an apparent density of 0.45 g cm(-3), a ball-pan hardness of 91.0, an iodine number of 454 mg g(-1), and a BET surface area of 403 m(2) g(-1). It contained high ash, nitrogen, phosphorus contents and the trace elements Cu, Zn, and As. Most of the nutrients and toxic elements were solidified and solution-unextractable. In general, poultry litter-based activated carbon demonstrated overall quality comparable to that of low-grade commercial activated carbon derived from coconut shell and bituminous coal. It is promising to use poultry litter as a feedstock to manufacture activated carbon for wastewater treatment.

  12. Powder metallurgy techniques in nuclear technology

    International Nuclear Information System (INIS)

    Mardon, P.G.

    1983-01-01

    The nuclear application of conventional powder metallurgy routes is centred on the fabrication of ceramic fuels. The stringent demands in terms of product performance required by the nuclear industry militate against the use of conventional powder metallurgy to produce metallic components such as the fuel cladding. However, the techniques developed in powder metallurgy find widespread application throughout nuclear technology. Illustrations of the use of these techniques are given in the fields of absorber materials, ceramic cladding materials, oxide fuels, cermet fuels, and the disposal of highly active waste. (author)

  13. Cheap carbon sorbents produced from lignite by catalytic pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, B.N.; Schchipko, M.L. [Inst. of Chemistry of Natural Organic Materials, Akademgorodok, Krasnoyarsk (Russian Federation)

    1995-12-01

    Some data are presented describing the new technology of carbon sorbent production from powdered lignite in the installation with fluidized bed of catalyst. It was shown the different types of char products with extended pore structure and high sorption ability can be produced from cheap and accessible lignite of Kansk-Achinsk coal pit in pilot installation with fluidized bed of Al-Cu-Cr oxide catalyst or catalytically active slag materials. In comparison with the conventional technologies of pyrolysis the catalytic pyrolysis allows to increase by 3-5 times the process productivity and to decrease significantly the formation of harmful compounds. The latter is accomplished by complete oxidation of gaseous pyrolysis products in the presence of catalysts and by avoiding the formation of pyrolysis tars - the source of cancerogenic compounds. The technology of cheap powdered sorbent production from lignites makes possible to obtain from lignite during the time of pyrolysis only a few seconds char products with porosity up to 0.6 cm{sup 3} /g, and specific surface area more than 400 m{sup 3} /g. Some methods of powdered chars molding into carbon materials with the different shape were proved for producing of firmness sorbents. Cheap carbon sorbents obtained by thermocatalytic pyrolysis can be successfully used in purification of different industrial pollutants as one-time sorbent or as adsorbents of long-term application with periodic regeneration.

  14. Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

    International Nuclear Information System (INIS)

    Oliver, S. A.; Harris, V. G.; Hamdeh, H. H.; Ho, J. C.

    2000-01-01

    The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn 0.55 2+ Fe 0.18 3+ ) tet [Zr 0.45 2+ Fe 1.82 3+ ] oct O 4 through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe 3+ on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics

  15. The mechanical and thermal characteristics of phenolic foam reinforced with kaolin powder and glass fiber fabric

    Science.gov (United States)

    Xiao, Wenya; Huang, Zhixiong; Ding, Jie

    2017-12-01

    In this work, kaolin powder and glass fiber fabric were added to PF in order to improve its thermal stability and mechanical property. Micro-structures of carbonized PF with kaolin powder were inspected by scanning electron microscopy (SEM) to demonstrate the filler’s pinning effect. SEM results illustrated modified PF had well morphology after high-temperature heat treatment. The Fourier transform infrared spectrometer (FTIR) test was carried out and found that kaolin powder only physically dispersed in PF. The compression test and thermal weight loss test were done on two groups of modified PF (Group A: add powder and fabric; Group B: add powder only). Results showed that all modified PF were better than pure PF, while foams with powder and fabric showed better mechanical characteristic and thermal stability compared with foams with powder only.

  16. Measurement of carbon activity in sodium and steel and the behaviour of carbon-bearing species

    International Nuclear Information System (INIS)

    Rajendran Pillai, S.; Ranganathan, R.; Mathews, C.K.

    1988-01-01

    Carburization or decarburization of structural materials in a sodium system depends on the local differences in carbon activity. The behaviour of carbon-bearing species in sodium influences its carbon activity. In order to understand the behaviour of carbon in these systems, an electrochemical carbon meter was fabricated in our laboratory. The original version of this meter was capable of operating in the temperature range of 850-980 K. Studies are carried out to extend this lower limit of temperature. Employing the carbon meter, experiments were carried out to understand the behaviour of carbon-bearing species. Gas equilibration experiments were also carried out with the same view. A new method for measuring the carbon activity in steels are described which employs the carbon meter. A review on these investigations and the conclusions reached on the behaviour of carbon in fast reactor loops are described

  17. SuperMAG: Present and Future Capabilities

    Science.gov (United States)

    Hsieh, S. W.; Gjerloev, J. W.; Barnes, R. J.

    2009-12-01

    SuperMAG is a global collaboration that provides ground magnetic field perturbations from a long list of stations in the same coordinate system, identical time resolution and with a common baseline removal approach. This unique high quality dataset provides a continuous and nearly global monitoring of the ground magnetic field perturbation. Currently, only archived data are available on the website and hence it targets basic research without any operational capabilities. The existing SuperMAG software can be easily adapted to ingest real-time or near real-time data and provide a now-casting capability. The SuperDARN program has a long history of providing near real-time maps of the northern hemisphere electrostatic potential and as both SuperMAG and SuperDARN share common software it is relatively easy to adapt these maps for global magnetic perturbations. Magnetometer measurements would be assimilated by the SuperMAG server using a variety of techniques, either by downloading data at regular intervals from remote servers or by real-time streaming connections. The existing SuperMAG analysis software would then process these measurements to provide the final calibrated data set using the SuperMAG coordinate system. The existing plotting software would then be used to produce regularly updated global plots. The talk will focus on current SuperMAG capabilities illustrating the potential for now-casting and eventually forecasting.

  18. Characterization of activated carbon produced from urban organic waste

    Directory of Open Access Journals (Sweden)

    Abdul Gani Haji

    2013-10-01

    Full Text Available The difficulties to decompose organic waste can be handled naturally by pyrolisis so it can  decomposes quickly that produces charcoal as the product. This study aims to investigate the characteristics of activated carbon from urban organic waste. Charcoal results of pyrolysis of organic waste activated with KOH 1.0 M at a temperature of 700 and 800oC for 60 to 120 minutes. Characteristics of activated carbon were identified by Furrier Transform Infra Red (FTIR, Scanning Electron Microscopy (SEM, and X-Ray Diffraction (XRD. However, their quality is determined yield, moisture content, ash, fly substances, fixed carbon, and the power of adsorption of iodine and benzene. The identified functional groups on activated carbon, such as OH (3448,5-3436,9 cm-1, and C=O (1639,4 cm-1. In general, the degree and distance between the layers of active carbon crystallites produced activation in all treatments showed no significant difference. The pattern of activated carbon surface topography structure shows that the greater the pore formation in accordance with the temperature increase the more activation time needed. The yield of activated carbon obtained ranged from 72.04 to 82.75%. The results of characterization properties of activated carbon was obtained from 1.11 to 5.41% water, 13.68 to 17.27% substance fly, 20.36 to 26.59% ash, and 56.14 to 62.31% of fixed carbon . Absorption of activated carbon was good enough at 800oC and 120 minutes of activation time, that was equal to 409.52 mg/g of iodine and 14.03% of benzene. Activated carbon produced has less good quality, because only the water content and flying substances that meet the standards.Doi: 10.12777/ijse.5.2.89-94 [How to cite this article: Haji, A.G., Pari, G., Nazar, M., and Habibati.  (2013. Characterization of activated carbon produced from urban organic waste . International Journal of Science and Engineering, 5(2,89-94. Doi: 10.12777/ijse.5.2.89-94

  19. Paracrystalline structure of activated carbons

    Science.gov (United States)

    Szczygielska, A.; Burian, A.; Dore, J. C.

    2001-06-01

    Structural studies by means of neutron diffraction of activated carbons, prepared from a polymer of phenol formaldehyde resin by carbonization and activation processes, with variable porosity, are presented. The neutron scattering data were recorded over the range of the scattering vector Q from 2.5 to 500 nm-1. The structure of activated carbons has been described in terms of disordered graphite-like layers with very weak interlayer correlations. The model has been generated by computer simulations and its validity has been tested by comparison of the experimental and calculated intensity functions. Modelling studies have shown that the model containing 3-4 layers each about 2 nm in diameter accounts for the experimental data and that graphite layers are randomly translated and rotated, according to the turbostratic structure. Near-neighbour carbon-carbon distances of about 0.139 nm and 0.154 nm have been determined. The Debye-Waller factor exp (-Q2σ2/2) with σ = σ0(r)1/2 suggests a paracrystalline structure within a single layer. The value of the interlayer spacing of 0.36 nm has been found from paracrystalline simulations of the layer arrangement in the c-axis direction. The high quality of the experimental data has enabled determination of the coordination numbers, the interatomic distances and their standard deviations using a curve-fitting procedure over the Q-range from 250 nm to 500 nm, providing structural information about short- and intermediate-range ordering.

  20. Combined wet-chemical process to synthesize 65PMN-35PT nanosized powders

    International Nuclear Information System (INIS)

    Santos, Luis P.S.; Longo, Elson; Leite, Edson R.; Camargo, Emerson R.

    2004-01-01

    Columbite MgNb 2 O 6 precursors were synthesized by a wet-chemical method by means of the dissolution of Nb 2 O 5 .5H 2 O and magnesium carbonate in a solution of oxalic acid. Pure 65PMN-35PT powders could be obtained by the columbite method with the use of the partial oxalate and oxidant peroxo methods. Powders were characterized by X-ray diffraction and FT-Raman spectroscopy showing that pure 65PMN-35PT are obtained when the powders are calcined up to 800 deg. C, without any trace of Pb-Nb pyrochlore. Cubic Pb 1,86 Mg 0.24 Nb 1.76 O 6.5 pyrochlore phase is formed by lead loss in the powders calcined at 900 deg. C and higher temperatures as undoubtedly characterized by Raman spectroscopy