WorldWideScience

Sample records for pan-based activated carbon

  1. Asymmetric Electrodes Constructed with PAN-Based Activated Carbon Fiber in Capacitive Deionization

    Directory of Open Access Journals (Sweden)

    Mingzhe Li

    2014-01-01

    Full Text Available Capacitive deionization (CDI method has drawn much attention for its low energy consumption, low pollution, and convenient manipulation. Activated carbon fibers (ACFs possess high adsorption ability and can be used as CDI electrode material. Herein, two kinds of PAN-based ACFs with different specific surface area (SSA were used for the CDI electrodes. The CDI performance was investigated; especially asymmetric electrodes’ effect was evaluated. The results demonstrated that PAN-based ACFs showed a high electrosorption rate (complete electrosorption in less than half an hour and moderate electrosorption capacity (up to 0.2 mmol/g. CDI experiments with asymmetric electrodes displayed a variation in electrosorption capacity between forward voltage and reverse voltage. It can be attributed to the electrical double layer (EDL overlap effect and inner pore potential; thus the ions with smaller hydrated ionic radius can be adsorbed more easily.

  2. Development and characterization of polyacrylonitrile (PAN based carbon hollow fiber membrane

    Directory of Open Access Journals (Sweden)

    Syed Mohd Saufi

    2002-11-01

    Full Text Available This paper reports the development and characterization of polyacrylonitrile (PAN based carbon hollow fiber membrane. Nitrogen was used as an inert gas during pyrolysis of the PAN hollow fiber membrane into carbon membrane. PAN membranes were pyrolyzed at temperature ranging from 500oC to 800oC for 30 minutes of thermal soak time. Scanning Electron Microscope (SEM, Fourier Transform Infrared Spectroscopy (FTIR and gas sorption analysis were applied to characterize the PAN based carbon membrane. Pyrolysis temperature was found to significantly change the structure and properties of carbon membrane. FTIR results concluded that the carbon yield still could be increased by pyrolyzing PAN membranes at temperature higher than 800oC since the existence of other functional group instead of CH group. Gas adsorption analysis showed that the average pore diameter increased up to 800oC.

  3. Properties and Structure of In Situ Transformed PAN-Based Carbon Fibers

    Directory of Open Access Journals (Sweden)

    Jingjing Cao

    2018-06-01

    Full Text Available Carbon fibers in situ prepared during the hot-pressed sintering in a vacuum is termed in situ transformed polyacrylonitrile-based (PAN-based carbon fibers, and the fibrous precursors are the pre-oxidized PAN fibers. The properties and structure of in situ transformed PAN-based carbon fibers are investigated by Nano indenter, SEM, TEM, XRD, and Raman. The results showed that the microstructure of the fiber surface layer was compact, while the core was loose, with evenly-appearing microvoids. The elastic modulus and nanohardness of the fiber surface layer (303.87 GPa and 14.82 GPa were much higher than that of the core (16.57 GPa and 1.54 GPa, and its interlayer spacing d002 and crystallinity were about 0.347 nm and 0.97 respectively. It was found that the preferred orientation of the surface carbon layers with ordered carbon atomic arrangement tended to be parallel to the fiber axis, whereas the fiber core in the amorphous region exhibited a random texture and the carbon atomic arrangement was in a disordered state. It indicates that the in situ transformed PAN-based carbon fibers possess significantly turbostratic structure and anisotropy.

  4. Activated carbon fiber obtained from textile PAN fiber to electrodes for supercapacitor

    International Nuclear Information System (INIS)

    Silva, Elen Leal da; Marcuzzo, Jossano Saldanha; Baldan, Mauricio Ribeiro; Cuna, Andres; Rodrigues, Aline Castilho; Goncalves, Emerson Sarmento

    2016-01-01

    Full text: Supercapacitors are devices for electrical energy storage with application in distribution power generation, electric vehicles, electronic equipment, among others. Current challenges in the development of supercapacitors focuses on making an increasing on system density of energy. An increase of energy accumulated in the supercapacitor electrode can be achieved by developing materials with high specific electrical capacitance and low electrical resistance. Furthermore, it is expected that the electrode material present a simple procedure for obtaining, low cost and environmentally friendly. Carbon fibers are interesting materials for use as a supercapacitor electrode. Among them are carbon fibers from polyacrylonitrile (PAN). In this work were studied activated carbon fibers obtained from textile polyacrylonitrile (ACF-PAN) with deposition of Fe particles aiming to use as active material of supercapacitor electrodes. ACFPAN and ACF-PAN-Fe were characterized by textural analysis, x-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive x-ray (SEM-EDX), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). The behavior of the activated carbon fibers as a supercapacitor electrode was evaluated by galvanostatic charge and discharge curves, cyclic voltammetry and a electrochemical impedance using a symmetrical two-electrode Swagelok®-type cell and sulfuric acid as electrolyte. ACF-PAN had a high specific surface area, which makes it an interesting material for electrodes of supercapacitors. The electrical capacitance for the ACF-PAN is 96 F/g and ACF-PAN-Fe is 106 F/g both at a current density of 0.30 A/g. This increase in electrical capacitance can be related to the presence of iron oxides which are deposited on the activated carbon fiber. (author)

  5. Microstructure study of PAN-pitch-based carbon-carbon composite

    International Nuclear Information System (INIS)

    Lee, K.J.; Chen, Z.Y.

    2003-01-01

    Scanning electron microscopy (SEM), polarized light microscopy (PLM), and transmission electron microscopy (TEM) techniques have been used to characterize the normal surface and flank surface microstructure of a two-dimensional polyacrylonitrile (PAN)-based fiber reinforced mesophase pitch-based matrix carbon-carbon (C-C) composite. Optical and SEM results indicate that the mesophase pitch appears generally well bonded to the fibers, as well as internal pores and cracks exist in both interbundle and intrabundle regions. TEM shows that matrix platelets were highly parallel to the fiber axis. Numerous microcracks, parallel to the fiber axis, were formed along fiber-matrix interface and within the matrix. The selected-area diffraction (SAD) patterns show that a random orientation of basal planes in the transverse fiber of flank surface and the domain near the fiber surface exhibited a better alignment

  6. Nitrogen-doped porous carbon monoliths from polyacrylonitrile (PAN) and carbon nanotubes as electrodes for supercapacitors

    Science.gov (United States)

    Wang, Yanqing; Fugetsu, Bunshi; Wang, Zhipeng; Gong, Wei; Sakata, Ichiro; Morimoto, Shingo; Hashimoto, Yoshio; Endo, Morinobu; Dresselhaus, Mildred; Terrones, Mauricio

    2017-01-01

    Nitrogen-doped porous activated carbon monoliths (NDP-ACMs) have long been the most desirable materials for supercapacitors. Unique to the conventional template based Lewis acid/base activation methods, herein, we report on a simple yet practicable novel approach to production of the three-dimensional NDP-ACMs (3D-NDP-ACMs). Polyacrylonitrile (PAN) contained carbon nanotubes (CNTs), being pre-dispersed into a tubular level of dispersions, were used as the starting material and the 3D-NDP-ACMs were obtained via a template-free process. First, a continuous mesoporous PAN/CNT based 3D monolith was established by using a template-free temperature-induced phase separation (TTPS). Second, a nitrogen-doped 3D-ACM with a surface area of 613.8 m2/g and a pore volume 0.366 cm3/g was obtained. A typical supercapacitor with our 3D-NDP-ACMs as the functioning electrodes gave a specific capacitance stabilized at 216 F/g even after 3000 cycles, demonstrating the advantageous performance of the PAN/CNT based 3D-NDP-ACMs. PMID:28074847

  7. Nitrogen-doped porous carbon monoliths from polyacrylonitrile (PAN) and carbon nanotubes as electrodes for supercapacitors.

    Science.gov (United States)

    Wang, Yanqing; Fugetsu, Bunshi; Wang, Zhipeng; Gong, Wei; Sakata, Ichiro; Morimoto, Shingo; Hashimoto, Yoshio; Endo, Morinobu; Dresselhaus, Mildred; Terrones, Mauricio

    2017-01-11

    Nitrogen-doped porous activated carbon monoliths (NDP-ACMs) have long been the most desirable materials for supercapacitors. Unique to the conventional template based Lewis acid/base activation methods, herein, we report on a simple yet practicable novel approach to production of the three-dimensional NDP-ACMs (3D-NDP-ACMs). Polyacrylonitrile (PAN) contained carbon nanotubes (CNTs), being pre-dispersed into a tubular level of dispersions, were used as the starting material and the 3D-NDP-ACMs were obtained via a template-free process. First, a continuous mesoporous PAN/CNT based 3D monolith was established by using a template-free temperature-induced phase separation (TTPS). Second, a nitrogen-doped 3D-ACM with a surface area of 613.8 m 2 /g and a pore volume 0.366 cm 3 /g was obtained. A typical supercapacitor with our 3D-NDP-ACMs as the functioning electrodes gave a specific capacitance stabilized at 216 F/g even after 3000 cycles, demonstrating the advantageous performance of the PAN/CNT based 3D-NDP-ACMs.

  8. Microstructural characterization of PAN based carbon fiber reinforced nylon 6 polymer composites

    Science.gov (United States)

    Munirathnamma, L. M.; Ningaraju, S.; Kumar, K. V. Aneesh; Ravikumar, H. B.

    2018-04-01

    Microstructural characterization of nylon 6/polyacrolonitrile based carbon fibers (PAN-CFs) of 10 to 40 wt% has been performed by positron lifetime technique (PLT). The positron lifetime parameters viz., o-Ps lifetime (τ3), o-Ps intensity (I3) and fractional free volume (Fv) of nylon 6/PAN-CF composites are correlated with the mechanical properties viz., Tensile strength and Young's modulus. The Fv show negative deviation with the reinforcement of 10 to 40 wt% of PAN-CF from the linear additivity relation. The negative deviation in nylon 6/PAN-CF composite suggests the induced molecular packing due to the chemical interaction between the polymeric chains of nylon 6 and PAN-CF. This is evident from Fourier Transform Infrared Spectrometry (FTIR) studies. The FTIR results suggests that observed negative deviation in PALS results of nylon 6/PAN-CF reinforced polymer composites is due to the induced chemical interaction at N-H-O sites. The improved tensile strength (TS) and Young's modulus (YM) in nylon 6/PAN-CF reinforced polymer composites is due to AS4C (surface treated and epoxy coated) PAN-CF has shown highest adhesion level due to better stress transfer between nylon 6 and PAN-CF.

  9. Assessing Toxicity of Obscurant Grade Pan-Based Carbon Fiber Aquatic Species Chronic Tests

    National Research Council Canada - National Science Library

    Chester, N. A; Haley, M. V; Kumas, C. W; Checkai, R. T

    2004-01-01

    ...). Use of polyacrylonitrile (PAN)-based carbon fiber in the module will provide user-capability for delivering large area obscurant screens in the millimeter wave-range of the electromagnetic spectrum while maintaining...

  10. Metal adsorption process in activated carbon fiber from textile PAN fiber aim electrode production

    International Nuclear Information System (INIS)

    Rodrigues, Aline Castilho; Goncalves, Emerson Sarmento; Silva, Elen Leal da; Marcuzzo, Jossano Saldanha; Baldan, Mauricio Ribeiro; Cuna, Andres

    2016-01-01

    Full text: Carbon fibers have a variety of applications in industry and have been increasingly studied to explore their various characteristics. Studies show that the activated carbon fiber has been effective in removing small contaminants as well as activated carbon, because of its characteristic porosity. Other studies relate carbonaceous materials to the electrical conductivity devices application. This work is based on the use of an activated carbon fiber from textile polyacrylonitrile (PAN) for metallic ion adsorption from aqueous solution. Consequently, it improves the electrical characteristics and this fact show the possibility to use this material as electrode. The work was performed by adsorption process in saline solution (NO 3 Ag and ClPd) and activated carbon fiber in felt form as adsorbent. The metal adsorption on activated carbon fiber was characterized by textural analysis, x-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive x-ray (SEM-EDX), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). It was observed that activated carbon fiber showed good adsorption capacity for the metals used. At the end of the process, the activated carbon fiber samples gained about 15% by weight, related to metallic fraction incorporated into the fiber and the process of adsorption does not changed the structural, morphological and chemistry inertness of the samples. The results indicate the feasibility of this metal incorporation techniques activated carbon fiber for the production of electrodes facing the electrochemical area. (author)

  11. Metal adsorption process in activated carbon fiber from textile PAN fiber aim electrode production

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Aline Castilho; Goncalves, Emerson Sarmento, E-mail: alinerodrigues_1@msn.com [Instituto Tecnologico Aeroespacial (ITA), Sao Jose dos Campos, SP (Brazil); Silva, Elen Leal da; Marcuzzo, Jossano Saldanha; Baldan, Mauricio Ribeiro [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Cuna, Andres [Faculdade de Quimica, Universidad de la Republica (Uruguay)

    2016-07-01

    Full text: Carbon fibers have a variety of applications in industry and have been increasingly studied to explore their various characteristics. Studies show that the activated carbon fiber has been effective in removing small contaminants as well as activated carbon, because of its characteristic porosity. Other studies relate carbonaceous materials to the electrical conductivity devices application. This work is based on the use of an activated carbon fiber from textile polyacrylonitrile (PAN) for metallic ion adsorption from aqueous solution. Consequently, it improves the electrical characteristics and this fact show the possibility to use this material as electrode. The work was performed by adsorption process in saline solution (NO{sub 3}Ag and ClPd) and activated carbon fiber in felt form as adsorbent. The metal adsorption on activated carbon fiber was characterized by textural analysis, x-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive x-ray (SEM-EDX), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). It was observed that activated carbon fiber showed good adsorption capacity for the metals used. At the end of the process, the activated carbon fiber samples gained about 15% by weight, related to metallic fraction incorporated into the fiber and the process of adsorption does not changed the structural, morphological and chemistry inertness of the samples. The results indicate the feasibility of this metal incorporation techniques activated carbon fiber for the production of electrodes facing the electrochemical area. (author)

  12. PAN-based carbon fiber negative electrodes for structural lithium-ion batteries

    OpenAIRE

    Hellqvist Kjell, Maria; Jacques, Eric; Zenkert, Dan; Behm, Mårten; Lindbergh, Göran

    2011-01-01

    Several grades of commercially-available polyacrylonitrile (PAN)-based carbon fibers have been studied for structural lithium-ion batteries to understand how the sizing, different lithiation rates and number of fibers per tow affect the available reversible capacity, when used as both current collector and electrode, for use in structural batteries. The study shows that at moderate lithiation rates, 100 mA g-1, most of the carbon fibers display a reversible capacity close to or above 100 mAh ...

  13. Influence of thermal treatment on porosity formation on carbon fiber from textile PAN

    Directory of Open Access Journals (Sweden)

    Jossano Saldanha Marcuzzo

    2012-01-01

    Full Text Available Activated carbon fibers (ACFs are known as an excellent adsorbent material due to their particular characteristics such as their high speed adsorption rate and for being easy to handle. The ACFs are commercially manufactured from carbon fibers (CF which receive an additional activation process and can be produced from celluloses, phenolic resin, pitch and Polyacrylonitrile (PAN. In the present work, the oxidized 5.0 dtex textile PAN fiber was carbonized to CFs formation. During the carbonization process in different heating rates, the topographic features changes on fibers were monitored in order to determine the best carbonization condition for CFs production to be used as raw material for ACF. Different heating rates and maximum temperature of treatment were tested and the results indicated that it is possible to produce poorly activated carbon fiber, directly from oxidized textile PAN fiber, by one single step production process.

  14. Influence of thermal treatment on porosity formation on carbon fiber from textile PAN

    Directory of Open Access Journals (Sweden)

    Jossano Saldanha Marcuzzo

    2013-02-01

    Full Text Available Activated carbon fibers (ACFs are known as an excellent adsorbent material due to their particular characteristics such as their high speed adsorption rate and for being easy to handle. The ACFs are commercially manufactured from carbon fibers (CF which receive an additional activation process and can be produced from celluloses, phenolic resin, pitch and Polyacrylonitrile (PAN. In the present work, the oxidized 5.0 dtex textile PAN fiber was carbonized to CFs formation. During the carbonization process in different heating rates, the topographic features changes on fibers were monitored in order to determine the best carbonization condition for CFs production to be used as raw material for ACF. Different heating rates and maximum temperature of treatment were tested and the results indicated that it is possible to produce poorly activated carbon fiber, directly from oxidized textile PAN fiber, by one single step production process.

  15. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    International Nuclear Information System (INIS)

    Li, Bin; Feng, Yi; Qian, Gang; Zhang, Jingcheng; Zhuang, Zhong; Wang, Xianping

    2013-01-01

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose

  16. Catalytic oxidation of NO to NO2 on activated carbon

    International Nuclear Information System (INIS)

    Zhancheng Guo; Yusheng Xie

    2001-01-01

    Catalytic oxidation of NO to NO 2 over activated carbons PAN-ACF, pitch-ACF and coconut-AC at room temperature (30 o C) were studied to develop a method based on oxidative removal of NO from flue gases. For a dry gas, under the conditions of a gas space flow rate 1500 h -1 in the presence of oxygen of 2-20% in volume concentration, the activated coconut carbon with a surface area 1200 m 2 /g converted about 81-94% of NO with increasing oxygen concentration, the pitch based activated carbon fiber with a surface area 1000 m 2 /g about 44-75%, and the polyacrylonitrile-based activated carbon fiber with a surface area 1810 m 2 /g about 25-68%. The order of activity of the activated carbons was PAN-ACF c P NO P O2 β (F/W), where β is 0.042, 0.16, 0.31 for the coconut-AC, the pitch-ACF and the PAN-ACF respectively, and k c is 0.94 at 30 o C. (author)

  17. Electroadsorption desalination with carbon nanotube/PAN-based carbon fiber felt composites as electrodes.

    Science.gov (United States)

    Liu, Yang; Zhou, Junbo

    2014-01-01

    The chemical vapor deposition method is used to prepare CNT (carbon nanotube)/PCF (PAN-based carbon fiber felt) composite electrodes in this paper, with the surface morphology of CNT/PCF composites and electroadsorption desalination performance being studied. Results show such electrode materials with three-dimensional network nanostructures having a larger specific surface area and narrower micropore distribution, with a huge number of reactive groups covering the surface. Compared with PCF electrodes, CNT/PCF can allow for a higher adsorption and desorption rate but lower energy consumption; meanwhile, under the condition of the same voltage change, the CNT/PCF electrodes are provided with a better desalination effect. The study also found that the higher the original concentration of the solution, the greater the adsorption capacity and the lower the adsorption rate. At the same time, the higher the solution's pH, the better the desalting; the smaller the ions' radius, the greater the amount of adsorption.

  18. Effect of anodic surface treatment on PAN-based carbon fiber and its relationship to the fracture toughness of the carbon fiber-reinforced polymer composites

    DEFF Research Database (Denmark)

    Sarraf, Hamid; Skarpova, Ludmila

    2008-01-01

    The effect of anodic surface treatment on the polyacrylonitrile (PAN)-based carbon fibers surface properties and the mechanical behavior of the resulting carbon fiber-polymer composites has been studied in terms of the contact angle measurements of fibers and the fracture toughness of composites...... in the fiber surface nature and the mechanical interfacial properties between the carbon fiber and epoxy resin matrix of the resulting composites, i.e., the fracture toughness. We suggest that good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices...

  19. Surface Properties of PAN-based Carbon Fibers Modified by Electrochemical Oxidization in Organic Electrolyte Systems

    Directory of Open Access Journals (Sweden)

    WU Bo

    2016-09-01

    Full Text Available PAN-based carbon fibers were modified by electrochemical oxidization using fatty alcohol polyoxyethylene ether phosphate (O3P, triethanolamine (TEOA and fatty alcohol polyoxyethylene ether ammonium phosphate (O3PNH4 as organic electrolyte respectively. Titration analysis, single fiber fracture strength measurement and field emission scanning electron microscopy (FE-SEM were used to evaluate the content of acidic functional group on the surface, mechanical properties and surface morphology of carbon fiber. The optimum process of electrochemical treatment obtained is at 50℃ for 2min and O3PNH4 (5%, mass fraction as the electrolyte with current density of 2A/g. In addition, the surface properties of modified carbon fibers were characterized by X-ray photoelectron spectroscopy (XPS and single fiber contact angle test. The results show that the hydrophilic acidic functional groups on the surface of carbon fiber which can enhance the surface energy are increased by the electrochemical oxidation using O3PNH4 as electrolyte, almost without any weakening to the mechanical properties of carbon fiber.

  20. Immobilization of CoCl2 (cobalt chloride) on PAN (polyacrylonitrile) composite nanofiber mesh filled with carbon nanotubes for hydrogen production from hydrolysis of NaBH4 (sodium borohydride)

    International Nuclear Information System (INIS)

    Li, Fang; Arthur, Ernest Evans; La, Dahye; Li, Qiming; Kim, Hern

    2014-01-01

    Composite nanofiber sheets containing multiwalled carbon nanotubes and cobalt chloride dispersed in PAN (polyacrylonitrile) were produced by an electrospinning technique. The synthesized PAN/CoCl 2 /CNTs composite nanofiber was used as the catalyst for hydrogen production from the hydrolysis of sodium borohydride. FT-IR characterization showed that the pretreated CNTs possess different organic functional groups which help improve the compatibility between CNTs and PAN organic polymer. SEM (scanning electron microscopy), TEM (transmission electron microscopy) and EDX (energy-dispersive X-ray technique) were used to characterize the composite nanofiber and it was found that CNTs can be coaxially dispersed into the PAN nanofiber. During the hydrolysis of NaBH 4 , this PAN/CoCl 2 /CNTs composite nanofiber exhibited higher catalytic activity compared to the composite without CNTs doping. Kinetic analysis of NaBH 4 hydrolysis shows that the reaction of NaBH 4 hydrolysis based on this catalyst can be ascribed to the first-order reaction and the activation energy of the catalyst was approximately 52.857 kJ/mol. Meanwhile, the composite nanofiber catalyst shows excellent stability and reusability in the recycling experiment. - Highlights: • Composite nanofiber sheets were prepared via electrospinning. • PAN (polyacrylonitrile)/CoCl 2 (cobalt chloride)/CNTs (carbon nanotubes) nanofiber was used as the catalyst for hydrogen production. • CNTs can be coaxially dispersed into the PAN nanofiber. • PAN/CoCl 2 /CNTs composite nanofiber exhibited higher catalytic activity. • The composite nanofiber catalyst shows excellent stability and reusability

  1. CdS loaded on coal based activated carbon nanofibers with enhanced photocatalytic property

    Science.gov (United States)

    Guo, Jixi; Guo, Mingxi; Jia, Dianzeng; Song, Xianli; Tong, Fenglian

    2016-08-01

    The coal based activated carbon nanofibers (CBACFs) were prepared by electrospinning a mixture of polyacrylonitrile (PAN) and acid treated coal. Cadmium sulfide (CdS) nanoparticles loaded on CBACFs were fabricated by solvothermal method. The obtained samples were characterized by FESEM, TEM, and XRD. The results reveal that the CdS nanoparticles are homogeneously dispersed on the surfaces of CBACFs. The CdS/CBACFs nanocomposites exhibited higher photoactivity for photodegradation of methyl blue (MB) under visible light irradiation than pure CdS nanoparticles. CBACFs can be used as low cost support materials for the preparation of nanocomposites with high photocatalytic activity.

  2. 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.

  3. 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.

  4. Advanced stabilization of PAN fibers for fabrication of carbon fibers by e-beam irradiation

    International Nuclear Information System (INIS)

    Jeun, Joon Pyo; Kim, Du Young; Shin, Hye Kyoung; Kang, Phil Hyun; Park, Jung Ki

    2012-01-01

    In recent years, the carbon fiber industry has been growing rapidly to meet the demand from efferent industries such as aerospace, military, turbine blades, light weight cylinders and pressure vessels. Generally, carbon fibers are manufactured by a controlled pyrolysis of stabilized precursor fiber such as polyacrylonitrile (PAN). In the stabilization step, the linear PAN molecules are first converted to cyclic structure. However, cyclization is a very complicated process and there are still differences of opinion on the reaction mechanisms. Photo-induced crosslinking and stabilization of PAN via ion beam, X-ray, gamma ray and UV irradiation has been reported in the literature. However, the process required a long stabilization time. In this work, a new and highly effective method of pretreatment PAN precursor fiber was described. The effect of the e-beam on the stabilization process of the fibers was investigated using differential scanning calorimeter (DSC) and X-ray diffraction (XRD) measurement

  5. Investigation of needleless electrospun PAN nanofiber mats

    Science.gov (United States)

    Sabantina, Lilia; Mirasol, José Rodríguez; Cordero, Tomás; Finsterbusch, Karin; Ehrmann, Andrea

    2018-04-01

    Polyacrylonitrile (PAN) can be spun from a nontoxic solvent (DMSO, dimethyl sulfoxide) and is nevertheless waterproof, opposite to the biopolymers which are spinnable from aqueous solutions. This makes PAN an interesting material for electrospinning nanofiber mats which can be used for diverse biotechnological or medical applications, such as filters, cell growth, wound healing or tissue engineering. On the other hand, PAN is a typical base material for producing carbon nanofibers. Nevertheless, electrospinning PAN necessitates convenient spinning parameters to create nanofibers without too many membranes or agglomerations. Thus we have studied the influence of spinning parameters on the needleless electrospinning process of PAN dissolved in DMSO and the resulting nanofiber mats.

  6. Does pan diameter influence carbon monoxide levels during heating of water to boiling point with a camping stove?

    Science.gov (United States)

    Leigh-Smith, Simon; Stevenson, Richard; Watt, Martin; Watt, Ian; McFadyen, Angus; Grant, Stan

    2004-01-01

    To determine whether pan diameter influences carbon monoxide (CO) concentration during heating of water to boiling point with a camping stove. The hypothesis was that increasing pan diameter increases CO concentration because of greater flame dispersal and a larger flame. This was a randomized, prospective study. A Coleman Dual Fuel 533 stove was used to heat pans of water to boiling point, with CO concentration monitored every 30 seconds for 5 minutes. The stove was inside a partially ventilated 200-L cardboard box model that was inside an environmental chamber at -6 degrees C. Water temperature, water volume, and flame characteristics were all standardized. Ten trials were performed for each of 2 pan diameters (base diameters of 165 mm [small] and 220 mm [large]). There was a significant difference (P = .002) between the pans for CO levels at each measurement interval from 60 seconds onward. These differences were markedly larger after 90 seconds, with a mean difference of 185 ppm (95% CI 115, 276 ppm) for all the results from 120 seconds onwards. This study has shown that there is significantly higher CO production with a large-diameter pan compared with a small-diameter pan. These findings were evident by using a camping stove to heat water to boiling point when a maximum blue flame was present throughout. Thus, in enclosed environments it is recommended that small-diameter pans be used in an attempt to prevent high CO levels.

  7. 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.

  8. Process Optimization and Emperical Modelling for Electrospun Polyacrylonitrile (PAN) Nanofiber Precursor of Carbon nanofibers

    NARCIS (Netherlands)

    Gu, S.Y.; Gu, S.; Ren, J.; Vancso, Gyula J.

    2005-01-01

    Ultrafine fibers were spun from polyacrylonitrile (PAN)/N,N-dimethyl formamide (DMF) solution as a precursor of carbon nanofibers using a homemade electrospinning set-up. Fibers with diameter ranging from 200 nm to 1200 nm were obtained. Morphology of fibers and distribution of fiber diameter were

  9. Carbon-fiber composite molecular sieves for gas separation

    Energy Technology Data Exchange (ETDEWEB)

    Jagtoyen, M.; Derbyshire, F. [Univ. of Kentucky, Lexington, KY (United States)

    1996-08-01

    This report describes continuing work on the activation and characterization of formed carbon fiber composites. The composites are produced at the Oak Ridge National Laboratory (ORNL) and activated at the Center for Applied Energy Research (CAER) using steam, CO{sub 2}, or O{sub 2} at different conditions of temperature and time, and with different furnace configurations. The general aims of the project are to produce uniformly activated samples with controlled pore structures for specialist applications such as gas separation and water treatment. In previous work the authors reported that composites produced from isotropic pitch fibers weighing up to 25g can be uniformly activated through the appropriate choice of reaction conditions and furnace configurations. They have now succeeded in uniformly activating composites of dimensions up to 12 x 7 x 6 cm, or up to about 166 gram - a scale-up factor of about six. Part of the work has involved the installation of a new furnace that can accommodate larger composites. Efforts were made to achieve uniform activation in both steam and CO{sub 2}. The authors have also succeeded in producing materials with very uniform and narrow pore size distributions by using a novel method involving low temperature oxygen chemisorption in combination with heat treatment in N{sub 2} at high temperatures. Work has also started on the activation of PAN based carbon fibers and fiber composites with the aim of producing composites with wide pore structures for use as catalyst supports. So far activation of the PAN fiber composites supplied by ORNL has been difficult which is attributed to the low reactivity of the PAN fibers. As a result, studies are now being made of the activation of the PAN fibers to investigate the optimum carbonization and activation conditions for PAN based fibers.

  10. Cross-linked PAN-based thin-film composite membranes for non-aqueous nanofiltration

    KAUST Repository

    Pérez-Manríquez, Liliana

    2015-01-01

    A new approach on the development of cross-linked PAN based thin film composite (TFC) membranes for non-aqueous application is presented in this work. Polypropylene backed neat PAN membranes fabricated by phase inversion process were cross-linked with hydrazine to get excellent solvent stability toward dimethylformamide (DMF). By interfacial polymerization a selective polyamide active layer was coated over the cross-linked PAN using N,N′-diamino piperazine (DAP) and trimesoyl chloride (TMC) as monomers. Permeation and molecular weight cut off (MWCO) experiments using various dyes were done to evaluate the performance of the membranes. Membranes developed by such method show excellent solvent stability toward DMF with a permeance of 1.7 L/m2 h bar and a molecular weight cut-off of less than 600 Da.

  11. Experimental and metabolic modeling evidence for a folate-cleaving side-activity of ketopantoate hydroxymethyltransferase (PanB

    Directory of Open Access Journals (Sweden)

    Jennifer eThiaville

    2016-03-01

    Full Text Available Tetrahydrofolate (THF and its one-carbon derivatives, collectively termed folates, are essential cofact¬ors, but are inherently unstable. While it is clear that chemical oxidation can cleave folates or damage their pterin precursors, very little is known about enzymatic damage to these molec-ules or about whether the folate biosynthesis pathway responds adaptively to damage to its end-pro¬¬ducts. The presence of a duplication of the gene encoding the folate biosynthesis enzyme 6-hydr¬oxymethyl-7,8-dihydropterin pyrophosphokinase (FolK in many sequenced bacterial gen-omes combined with a strong chromosomal clustering of the folK gene with panB, encoding the 5,10-methylene-THF-dependent enzyme ketopantoate hydroxymethyltransferase, led us to infer that PanB has a side activity that cleaves 5,10-methylene-THF, yielding a pterin product that is recycled by FolK. Genetic and metabolic analyses of Escherichia coli strains showed that over-expression of PanB leads to accumulation of the likely folate cleavage product 6-hydroxy¬methyl-pterin and other pterins in cells and medium, and – unexpectedly – to a 46% increase in total fol-ate content. In silico modeling of the folate bio¬syn¬thesis pathway showed that these observations are consistent with the in vivo cleavage of 5,10-methylene-THF by a side-activity of PanB, with FolK-mediated recycling of the pterin cleavage product, and with regulation of folate biosynth-esis by folates or their damage products.

  12. Scaffold-based pan-agonist design for the PPARα, PPARβ and PPARγ receptors.

    Directory of Open Access Journals (Sweden)

    Li-Song Zhang

    Full Text Available As important members of nuclear receptor superfamily, Peroxisome proliferator-activated receptors (PPAR play essential roles in regulating cellular differentiation, development, metabolism, and tumorigenesis of higher organisms. The PPAR receptors have 3 identified subtypes: PPARα, PPARβ and PPARγ, all of which have been treated as attractive targets for developing drugs to treat type 2 diabetes. Due to the undesirable side-effects, many PPAR agonists including PPARα/γ and PPARβ/γ dual agonists are stopped by US FDA in the clinical trials. An alternative strategy is to design novel pan-agonist that can simultaneously activate PPARα, PPARβ and PPARγ. Under such an idea, in the current study we adopted the core hopping algorithm and glide docking procedure to generate 7 novel compounds based on a typical PPAR pan-agonist LY465608. It was observed by the docking procedures and molecular dynamics simulations that the compounds generated by the core hopping and glide docking not only possessed the similar functions as the original LY465608 compound to activate PPARα, PPARβ and PPARγ receptors, but also had more favorable conformation for binding to the PPAR receptors. The additional absorption, distribution, metabolism and excretion (ADME predictions showed that the 7 compounds (especially Cpd#1 hold high potential to be novel lead compounds for the PPAR pan-agonist. Our findings can provide a new strategy or useful insights for designing the effective pan-agonists against the type 2 diabetes.

  13. 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.

  14. Cathode spot movements along the carbon fibres in carbon/carbon composites

    International Nuclear Information System (INIS)

    Zhang Chengyu; Qiao Shengru; Yang Zhimao; Ding Bingjun

    2007-01-01

    The cathode spot movements on a polyacrilonitrile (PAN)-based carbon felt reinforced C/C composite and a three dimensional PAN-based carbon fibre reinforced C/C composite (3D-C/C) were investigated by a scanning electron microscope and a digital high-speed video camera. It was found that the carbon fibres have a higher ability to withstand the vacuum arc erosion than the carbon matrix. The cathode spot walks on the matrix, rather than on the carbon fibres. The cathode spot motion is controlled by the architecture of carbon fibres in C/C. The cathode spots move along the carbon fibres by a step-by-step manner rather than a random walk. The cathode spot tracks spread over a wide zone on the 3D-C/C surface parallel to the carbon fibre. The average arc spreading velocity is estimated to be about 0.9 m s -1 and the transient arc spreading velocity is in the range of 0.54-4.5 m s -1

  15. Electrochemical behavior of pitch-based activated carbon fibers for electrochemical capacitors

    International Nuclear Information System (INIS)

    Lee, Hye-Min; Kwac, Lee-Ku; An, Kay-Hyeok; Park, Soo-Jin; Kim, Byung-Joo

    2016-01-01

    Highlights: • Electrode materials for electrochemical capacitors were developed using pitch-based activated carbon fibers with steam activation. • Activated carbon fibers showed enhanced specific surface area from 1520 to 3230 m 2 /g. • The increase in the specific capacitance of the samples was determined by charged pore structure during charging and discharging. - Abstract: In the present study, electrode materials for electrochemical capacitors were developed using pitch-based activated carbon fibers with steam activation. The surface and structural characteristics of activated carbon fibers were observed using scanning electron microscopy and X-ray diffraction, respectively. Pore characteristics were investigated using N 2 /77 K adsorption isotherms. The activated carbon fibers were applied as electrodes for electrical double-layer capacitors and analyzed in relation to the activation time. The specific surface area and total pore volume of the activated carbon fibers were determined to be 1520–3230 m 2 /g and 0.61–1.87 cm 3 /g, respectively. In addition, when the electrochemical characteristics were analyzed, the specific capacitance was confirmed to have increased from 1.1 F/g to 22.5 F/g. From these results, it is clear that the pore characteristics of pitch-based activated carbon fibers changed considerably in relation to steam activation and charge/discharge cycle; therefore, it was possible to improve the electrochemical characteristics of the activated carbon fibers.

  16. Electrically controllable artificial PAN muscles

    Science.gov (United States)

    Salehpoor, Karim; Shahinpoor, Mohsen; Mojarrad, Mehran

    1996-02-01

    Artificial muscles made with polyacrylonitrile (PAN) fibers are traditionally activated in electrolytic solution by changing the pH of the solution by the addition of acids and/or bases. This usually consumes a considerable amount of weak acids or bases. Furthermore, the synthetic muscle (PAN) itself has to be impregnated with an acid or a base and must have an appropriate enclosure or provision for waste collection after actuation. This work introduces a method by which the PAN muscle may be elongated or contracted in an electric field. We believe this is the first time that this has been achieved with PAN fibers as artificial muscles. In this new development the PAN muscle is first put in close contact with one of the two platinum wires (electrodes) immersed in an aqueous solution of sodium chloride. Applying an electric voltage between the two wires changes the local acidity of the solution in the regions close to the platinum wires. This is because of the ionization of sodium chloride molecules and the accumulation of Na+ and Cl- ions at the negative and positive electrode sites, respectively. This ion accumulation, in turn, is accompanied by a sharp increase and decrease of the local acidity in regions close to either of the platinum wires, respectively. An artificial muscle, in close contact with the platinum wire, because of the change in the local acidity will contract or expand depending on the polarity of the electric field. This scheme allows the experimenter to use a fixed flexible container of an electrolytic solution whose local pH can be modulated by an imposed electric field while the produced ions are basically trapped to stay in the neighborhood of a given electrode. This method of artificial muscle activation has several advantages. First, the need to use a large quantity of acidic or alkaline solutions is eliminated. Second, the use of a compact PAN muscular system is facilitated for applications in active musculoskeletal structures. Third, the

  17. Radiochemical neutron activation analysis for trace elements of basic ingredients of pan

    International Nuclear Information System (INIS)

    Zaidi, J.H.; Arif, M.; Fatima, I; Qureshi, I.H.

    2002-01-01

    Extensive use of pan, by one-tenth of world's population, entails the evaluation of trace element contents in its ingredients. Radiochemical neutron activation analysis (RNAA) was developed and successfully employed to determine the concentration of 36 trace elements (essential, toxic and nonessential) in its four basic ingredients, leaf of betel pepper, betel nut, catechu and lime. The radiochemical separation methodology has significantly improved the detection limits of most of these elements due to suppression of Compton background. Base-line values of certain toxic and essential elements in these ingredients is provided. The daily intake of essential and toxic elements through pan was estimated and compared with the recommended values. The cumulative intake of Mn is four times higher than the recommended value and that of toxic elements is well below the tolerance limits. (author)

  18. Cell-type-specific activation of mitogen-activated protein kinases in PAN-induced progressive renal disease in rats

    International Nuclear Information System (INIS)

    Park, Sang-Joon; Jeong, Kyu-Shik

    2004-01-01

    We examined the time-course activation and the cell-type specific role of MAP kinases in puromycin aminonucleoside (PAN)-induced renal disease. The maximal activation of c-Jun-NH 2 -terminal kinase (JNK), extracellular signal regulated kinase (ERK), and p38 MAP kinase was detected on Days 52, 38, and 38 after PAN-treatment, respectively. p-JNK was localized in mesangial and proximal tubular cells at the early renal injury. It was expressed, therefore, in the inflammatory cells of tubulointerstitial lesions. While, p-ERK was markedly increased in the glomerular regions and macrophages p-p38 was observed in glomerular endothelial cells, tubular cells, and some inflammatory cells. The results show that the activation of MAP kinases in the early renal injury by PAN-treatment involves cellular changes such as cell proliferation or apoptosis in renal native cells. The activation of MAP kinases in infiltrated inflammatory cells and fibrotic cells plays an important role in destructive events such as glomerulosclerosis and tubulointerstitial fibrosis

  19. PanFP: pangenome-based functional profiles for microbial communities.

    Science.gov (United States)

    Jun, Se-Ran; Robeson, Michael S; Hauser, Loren J; Schadt, Christopher W; Gorin, Andrey A

    2015-09-26

    For decades there has been increasing interest in understanding the relationships between microbial communities and ecosystem functions. Current DNA sequencing technologies allows for the exploration of microbial communities in two principle ways: targeted rRNA gene surveys and shotgun metagenomics. For large study designs, it is often still prohibitively expensive to sequence metagenomes at both the breadth and depth necessary to statistically capture the true functional diversity of a community. Although rRNA gene surveys provide no direct evidence of function, they do provide a reasonable estimation of microbial diversity, while being a very cost-effective way to screen samples of interest for later shotgun metagenomic analyses. However, there is a great deal of 16S rRNA gene survey data currently available from diverse environments, and thus a need for tools to infer functional composition of environmental samples based on 16S rRNA gene survey data. We present a computational method called pangenome-based functional profiles (PanFP), which infers functional profiles of microbial communities from 16S rRNA gene survey data for Bacteria and Archaea. PanFP is based on pangenome reconstruction of a 16S rRNA gene operational taxonomic unit (OTU) from known genes and genomes pooled from the OTU's taxonomic lineage. From this lineage, we derive an OTU functional profile by weighting a pangenome's functional profile with the OTUs abundance observed in a given sample. We validated our method by comparing PanFP to the functional profiles obtained from the direct shotgun metagenomic measurement of 65 diverse communities via Spearman correlation coefficients. These correlations improved with increasing sequencing depth, within the range of 0.8-0.9 for the most deeply sequenced Human Microbiome Project mock community samples. PanFP is very similar in performance to another recently released tool, PICRUSt, for almost all of survey data analysed here. But, our method is unique

  20. Impacts of 2°C global warming on primary production and soil carbon storage capacity at pan-European level

    Directory of Open Access Journals (Sweden)

    Abdulla Sakalli

    2017-08-01

    Full Text Available Atmospheric CO2 has been dramatically increasing since beginning of the industrial time (i.e. 1860, being one of the main driver for climate change at regional and global level. The change in CO2 concentration in the atmosphere, together with that of temperature, precipitation and/or so radiation, can influence the biogeochemical cycles in all ecosystems. In this study, we investigate the combined effect of CO2 concentration and six climate variables on carbon uptake, i.e., gross primary production (GPP and carbon storage, i.e, soil carbon (SoilC in terrestrial biosphere by using the Community Land Model (CLM vers. 4.5 and evaluate the model’s results against available observation data. We also analysed the change in carbon uptake and storage under a 2°C global mean warming. Results show that the model performed reasonably well for GPP and SoilC at pan-European scale. We also found a positive correlation between GPP, precipitation and surface wind, and a negative correlation between GPP and surface downwelling longwave radiation (rlds. Under a 2°C global warming, GPP and SoilC show an increase, an average, of about 20%, and 5% at pan-European scale, respectively. However, our results indicate that CLM4.5 may need improvements particularly in carbon-nitrogen interaction and carbon accumulation in soil.

  1. Optimization of Preparation Program for Biomass Based Porous Active Carbon by Response Surface Methodology Based on Adsorptive Property

    Directory of Open Access Journals (Sweden)

    ZHANG Hao

    2017-06-01

    Full Text Available With waste walnut shell as raw material, biomass based porous active carbon was made by microwave oven method. The effects of microwave power, activation time and mass fraction of phosphoric acid on adsorptive property of biomass based porous active carbon in the process of physical activation of active carbon precursor were studied by response surface method and numerical simulation method, the preparation plan of biomass based porous active carbon was optimized, and the optimal biomass based porous active carbon property was characterized. The results show that three factors affect the adsorptive property of biomass based porous active carbon, but the effect of microwave power is obviously more significant than that of mass fraction of phosphoric acid, and the effect of mass fraction of phosphoric acid is more significant than that of activation time. The optimized preparation conditions are:microwave power is 746W, activation time is 11.2min and mass fraction of phosphoric acid is 85.9% in the process of physical activation of activated carbon precursor by microwave heating method. For the optimal biomass based porous active carbon, the adsorption value of iodine is 1074.57mg/g, adsorption value of methylene blue is 294.4mL/g and gain rate is 52.1%.

  2. Adsorptive removal of hydrophobic organic compounds by carbonaceous adsorbents: a comparative study of waste-polymer-based, coal-based activated carbon, and carbon nanotubes.

    Science.gov (United States)

    Lian, Fei; Chang, Chun; Du, Yang; Zhu, Lingyan; Xing, Baoshan; Liu, Chang

    2012-01-01

    Adsorption of the hydrophobic organic compounds (HOCs) trichloroethylene (TCE), 1,3-dichlorobenzene (DCB), 1,3-dinitrobenzene (DNB) and gamma-hexachlorocyclohexane (HCH) on five different carbonaceous materials was compared. The adsorbents included three polymer-based activated carbons, one coal-based activated carbon (F400) and multiwalled carbon nanotubes (MWNT). The polymer-based activated carbons were prepared using KOH activation from waste polymers: polyvinyl chloride (PVC), polyethyleneterephthalate (PET) and tire rubber (TR). Compared with F400 and MWNT, activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs, attributed to their extremely large hydrophobic surface area (2700 m2/g) and highly mesoporous structures. Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect. In contrast, due to the molecular sieving effect, their adsorption on HCH was lower. MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.

  3. Adsorption of volatile organic compounds by pecan shell- and almond shell-based granular activated carbons.

    Science.gov (United States)

    Bansode, R R; Losso, J N; Marshall, W E; Rao, R M; Portier, R J

    2003-11-01

    The objective of this research was to determine the effectiveness of using pecan and almond shell-based granular activated carbons (GACs) in the adsorption of volatile organic compounds (VOCs) of health concern and known toxic compounds (such as bromo-dichloromethane, benzene, carbon tetrachloride, 1,1,1-trichloromethane, chloroform, and 1,1-dichloromethane) compared to the adsorption efficiency of commercially used carbons (such as Filtrasorb 200, Calgon GRC-20, and Waterlinks 206C AW) in simulated test medium. The pecan shell-based GACs were activated using steam, carbon dioxide or phosphoric acid. An almond shell-based GAC was activated with phosphoric acid. Our results indicated that steam- or carbon dioxide-activated pecan shell carbons were superior in total VOC adsorption to phosphoric acid-activated pecan shell or almond shell carbons, inferring that the method of activation selected for the preparation of activated carbons affected the adsorption of VOCs and hence are factors to be considered in any adsorption process. The steam-activated, pecan shell carbon adsorbed more total VOCs than the other experimental carbons and had an adsorption profile similar to the two coconut shell-based commercial carbons, but had greater adsorption than the coal-based commercial carbon. All the carbons studied adsorbed benzene more effectively than the other organics. Pecan shell, steam-activated and acid-activated GACs showed higher adsorption of 1,1,1-trichloroethane than the other carbons studied. Multivariate analysis was conducted to group experimental carbons and commercial carbons based on their physical, chemical, and adsorptive properties. The results of the analysis conclude that steam-activated and acid-activated pecan shell carbons clustered together with coal-based and coconut shell-based commercial carbons, thus inferring that these experimental carbons could potentially be used as alternative sources for VOC adsorption in an aqueous environment.

  4. Poultry litter-based activated carbon for removing heavy metal ions in water.

    Science.gov (United States)

    Guo, Mingxin; Qiu, Guannan; Song, Weiping

    2010-02-01

    Utilization of poultry litter as a precursor material to manufacture activated carbon for treating heavy metal-contaminated water is a value-added strategy for recycling the organic waste. Batch adsorption experiments were conducted to investigate kinetics, isotherms, and capacity of poultry litter-based activated carbon for removing heavy metal ions in water. It was revealed that poultry litter-based activated carbon possessed significantly higher adsorption affinity and capacity for heavy metals than commercial activated carbons derived from bituminous coal and coconut shell. Adsorption of metal ions onto poultry litter-based carbon was rapid and followed Sigmoidal Chapman patterns as a function of contact time. Adsorption isotherms could be described by different models such as Langmuir and Freundlich equations, depending on the metal species and the coexistence of other metal ions. Potentially 404 mmol of Cu2+, 945 mmol of Pb2+, 236 mmol of Zn2+, and 250-300 mmol of Cd2+ would be adsorbed per kg of poultry litter-derived activated carbon. Releases of nutrients and metal ions from litter-derived carbon did not pose secondary water contamination risks. The study suggests that poultry litter can be utilized as a precursor material for economically manufacturing granular activated carbon that is to be used in wastewater treatment for removing heavy metals.

  5. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  6. Adsorptive removal of hydrophobic organic compounds by carbonaceous adsorbents: A comparative study of waste-polymer-based,coal-based activated carbon, and carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Fei Lian; Chun Chang; Yang Du; Lingyan Zhu; Baoshan Xing; Chang Liu

    2012-01-01

    Adsorption of the hydrophobic organic compounds (HOCs) trichloroethylene (TCE),1,3-dichlorobenzene (DCB),1,3-dinitrobenzene (DNB) and γ-hexachlorocyclohexane (HCH) on five different carbonaceous materials was compared.The adsorbents included three polymer-based activated carbons,one coal-based activated carbon (F400) and multiwalled carbon nanotubes (MWNT).The polymerbased activated carbons were prepared using KOH activation from waste polymers:polyvinyl chloride (PVC),polyethyleneterephthalate (PET) and tire rubber (TR).Compared with F400 and MWNT,activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs,attributed to their extremely large hydrophobic surface area (2700 m2/g) and highly mesoporous structures.Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect.In contrast,due to the molecular sieving effect,their adsorption on HCH was lower.MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.

  7. A high-throughput screen against pantothenate synthetase (PanC identifies 3-biphenyl-4-cyanopyrrole-2-carboxylic acids as a new class of inhibitor with activity against Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Anuradha Kumar

    Full Text Available The enzyme pantothenate synthetase, PanC, is an attractive drug target in Mycobacterium tuberculosis. It is essential for the in vitro growth of M. tuberculosis and for survival of the bacteria in the mouse model of infection. PanC is absent from mammals. We developed an enzyme-based assay to identify inhibitors of PanC, optimized it for high-throughput screening, and tested a large and diverse library of compounds for activity. Two compounds belonging to the same chemical class of 3-biphenyl-4- cyanopyrrole-2-carboxylic acids had activity against the purified recombinant protein, and also inhibited growth of live M. tuberculosis in manner consistent with PanC inhibition. Thus we have identified a new class of PanC inhibitors with whole cell activity that can be further developed.

  8. A high-throughput screen against pantothenate synthetase (PanC) identifies 3-biphenyl-4-cyanopyrrole-2-carboxylic acids as a new class of inhibitor with activity against Mycobacterium tuberculosis.

    Science.gov (United States)

    Kumar, Anuradha; Casey, Allen; Odingo, Joshua; Kesicki, Edward A; Abrahams, Garth; Vieth, Michal; Masquelin, Thierry; Mizrahi, Valerie; Hipskind, Philip A; Sherman, David R; Parish, Tanya

    2013-01-01

    The enzyme pantothenate synthetase, PanC, is an attractive drug target in Mycobacterium tuberculosis. It is essential for the in vitro growth of M. tuberculosis and for survival of the bacteria in the mouse model of infection. PanC is absent from mammals. We developed an enzyme-based assay to identify inhibitors of PanC, optimized it for high-throughput screening, and tested a large and diverse library of compounds for activity. Two compounds belonging to the same chemical class of 3-biphenyl-4- cyanopyrrole-2-carboxylic acids had activity against the purified recombinant protein, and also inhibited growth of live M. tuberculosis in manner consistent with PanC inhibition. Thus we have identified a new class of PanC inhibitors with whole cell activity that can be further developed.

  9. Using TES retrievals to investigate PAN in North American biomass burning plumes

    Science.gov (United States)

    Fischer, Emily V.; Zhu, Liye; Payne, Vivienne H.; Worden, John R.; Jiang, Zhe; Kulawik, Susan S.; Brey, Steven; Hecobian, Arsineh; Gombos, Daniel; Cady-Pereira, Karen; Flocke, Frank

    2018-04-01

    Peroxyacyl nitrate (PAN) is a critical atmospheric reservoir for nitrogen oxide radicals, and plays a lead role in their redistribution in the troposphere. We analyze new Tropospheric Emission Spectrometer (TES) PAN observations over North America from July 2006 to July 2009. Using aircraft observations from the Colorado Front Range, we demonstrate that TES can be sensitive to elevated PAN in the boundary layer (˜ 750 hPa) even in the presence of clouds. In situ observations have shown that wildfire emissions can rapidly produce PAN, and PAN decomposition is an important component of ozone production in smoke plumes. We identify smoke-impacted TES PAN retrievals by co-location with NOAA Hazard Mapping System (HMS) smoke plumes. Depending on the year, 15-32 % of cases where elevated PAN is identified in TES observations (retrievals with degrees of freedom (DOF) > 0.6) overlap smoke plumes during July. Of all the retrievals attempted in the July 2006 to July 2009 study period, 18 % is associated with smoke . A case study of smoke transport in July 2007 illustrates that PAN enhancements associated with HMS smoke plumes can be connected to fire complexes, providing evidence that TES is sufficiently sensitive to measure elevated PAN several days downwind of major fires. Using a subset of retrievals with TES 510 hPa carbon monoxide (CO) > 150 ppbv, and multiple estimates of background PAN, we calculate enhancement ratios for tropospheric average PAN relative to CO in smoke-impacted retrievals. Most of the TES-based enhancement ratios fall within the range calculated from in situ measurements.

  10. Afro-Americans and Early Pan-Africanism

    Science.gov (United States)

    Contee, Clarence G.

    1970-01-01

    History of the Pan-African movement, the roles of W.E.B.Du Bois and Marcus Garvey in the movement activities, and the shift to African based leadership of the movement in the 1940's are discussed. (KG)

  11. Biotechnology humic acids-based electrospun carbon nanofibers as cost-efficient electrodes for lithium-ion batteries

    International Nuclear Information System (INIS)

    Zhao, Pin-Yi; Guo, Yan; Yu, Bao-Jun; Zhang, Jie; Wang, Cheng-Yang

    2016-01-01

    Bio-based, cost-effective carbon nanofibers are fabricated from polyacrylonitrile (PAN) – refined biotechnology humic acids (RB) via simple eletrospinning after stabilization and carbonization. The influence of PAN/RB mass ratios and heat-treatment temperatures (HTTs) on structure and morphology is systematically studied. Excitingly, a first discharge/charge capacity of 937.9/613.4 mAh g −1 (coulombic efficiency of 65.4%) is achieved at 20 mA g −1 for PB7/3-800 in lithium-ion batteries (LIBs). Meanwhile, a charge capacity of 348.2 mAh g −1 (about 89% retention ratio) remains even after 100 cycles at 0.1 A g −1 . It is demonstrated that biomass humic acids can be applied as a promising precursor to fabricate high performance, low-cost, as well as “green” carbon electrode material for LIBs.

  12. SWEPP PAN assay system uncertainty analysis: Active mode measurements of solidified aqueous sludge waste

    International Nuclear Information System (INIS)

    Blackwood, L.G.; Harker, Y.D.; Meachum, T.R.

    1997-12-01

    The Idaho National Engineering and Environmental Laboratory is being used as a temporary storage facility for transuranic waste generated by the US Nuclear Weapons program at the Rocky Flats Plant (RFP) in Golden, Colorado. Currently, there is a large effort in progress to prepare to ship this waste to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. In order to meet the TRU Waste Characterization Quality Assurance Program Plan nondestructive assay compliance requirements and quality assurance objectives, it is necessary to determine the total uncertainty of the radioassay results produced by the Stored Waste Examination Pilot Plant (SWEPP) Passive Active Neutron (PAN) radioassay system. This paper is one of a series of reports quantifying the results of the uncertainty analysis of the PAN system measurements for specific waste types and measurement modes. In particular this report covers active mode measurements of weapons grade plutonium-contaminated aqueous sludge waste contained in 208 liter drums (item description codes 1, 2, 7, 800, 803, and 807). Results of the uncertainty analysis for PAN active mode measurements of aqueous sludge indicate that a bias correction multiplier of 1.55 should be applied to the PAN aqueous sludge measurements. With the bias correction, the uncertainty bounds on the expected bias are 0 ± 27%. These bounds meet the Quality Assurance Program Plan requirements for radioassay systems

  13. PAN-SHARPENING APPROACHES BASED ON UNMIXING OF MULTISPECTRAL REMOTE SENSING IMAGERY

    Directory of Open Access Journals (Sweden)

    G. Palubinskas

    2016-06-01

    Full Text Available Model based analysis or explicit definition/listing of all models/assumptions used in the derivation of a pan-sharpening method allows us to understand the rationale or properties of existing methods and shows a way for a proper usage or proposal/selection of new methods ‘better’ satisfying the needs of a particular application. Most existing pan-sharpening methods are based mainly on the two models/assumptions: spectral consistency for high resolution multispectral data (physical relationship between multispectral and panchromatic data in a high resolution scale and spatial consistency for multispectral data (so-called Wald’s protocol first property or relationship between multispectral data in different resolution scales. Two methods, one based on a linear unmixing model and another one based on spatial unmixing, are described/proposed/modified which respect models assumed and thus can produce correct or physically justified fusion results. Earlier mentioned property ‘better’ should be measurable quantitatively, e.g. by means of so-called quality measures. The difficulty of a quality assessment task in multi-resolution image fusion or pan-sharpening is that a reference image is missing. Existing measures or so-called protocols are still not satisfactory because quite often the rationale or assumptions used are not valid or not fulfilled. From a model based view it follows naturally that a quality assessment measure can be defined as a combination of error model residuals using common or general models assumed in all fusion methods. Thus in this paper a comparison of the two earlier proposed/modified pan-sharpening methods is performed. Preliminary experiments based on visual analysis are carried out in the urban area of Munich city for optical remote sensing multispectral data and panchromatic imagery of the WorldView-2 satellite sensor.

  14. Using TES retrievals to investigate PAN in North American biomass burning plumes

    Directory of Open Access Journals (Sweden)

    E. V. Fischer

    2018-04-01

    Full Text Available Peroxyacyl nitrate (PAN is a critical atmospheric reservoir for nitrogen oxide radicals, and plays a lead role in their redistribution in the troposphere. We analyze new Tropospheric Emission Spectrometer (TES PAN observations over North America from July 2006 to July 2009. Using aircraft observations from the Colorado Front Range, we demonstrate that TES can be sensitive to elevated PAN in the boundary layer (∼ 750 hPa even in the presence of clouds. In situ observations have shown that wildfire emissions can rapidly produce PAN, and PAN decomposition is an important component of ozone production in smoke plumes. We identify smoke-impacted TES PAN retrievals by co-location with NOAA Hazard Mapping System (HMS smoke plumes. Depending on the year, 15–32 % of cases where elevated PAN is identified in TES observations (retrievals with degrees of freedom (DOF > 0.6 overlap smoke plumes during July. Of all the retrievals attempted in the July 2006 to July 2009 study period, 18 % is associated with smoke . A case study of smoke transport in July 2007 illustrates that PAN enhancements associated with HMS smoke plumes can be connected to fire complexes, providing evidence that TES is sufficiently sensitive to measure elevated PAN several days downwind of major fires. Using a subset of retrievals with TES 510 hPa carbon monoxide (CO > 150 ppbv, and multiple estimates of background PAN, we calculate enhancement ratios for tropospheric average PAN relative to CO in smoke-impacted retrievals. Most of the TES-based enhancement ratios fall within the range calculated from in situ measurements.

  15. Machine Learning Detects Pan-cancer Ras Pathway Activation in The Cancer Genome Atlas

    Directory of Open Access Journals (Sweden)

    Gregory P. Way

    2018-04-01

    Full Text Available Summary: Precision oncology uses genomic evidence to match patients with treatment but often fails to identify all patients who may respond. The transcriptome of these “hidden responders” may reveal responsive molecular states. We describe and evaluate a machine-learning approach to classify aberrant pathway activity in tumors, which may aid in hidden responder identification. The algorithm integrates RNA-seq, copy number, and mutations from 33 different cancer types across The Cancer Genome Atlas (TCGA PanCanAtlas project to predict aberrant molecular states in tumors. Applied to the Ras pathway, the method detects Ras activation across cancer types and identifies phenocopying variants. The model, trained on human tumors, can predict response to MEK inhibitors in wild-type Ras cell lines. We also present data that suggest that multiple hits in the Ras pathway confer increased Ras activity. The transcriptome is underused in precision oncology and, combined with machine learning, can aid in the identification of hidden responders. : Way et al. develop a machine-learning approach using PanCanAtlas data to detect Ras activation in cancer. Integrating mutation, copy number, and expression data, the authors show that their method detects Ras-activating variants in tumors and sensitivity to MEK inhibitors in cell lines. Keywords: Gene expression, machine learning, Ras, NF1, KRAS, NRAS, HRAS, pan-cancer, TCGA, drug sensitivity

  16. Food protection activities of the Pan American Health Organization.

    Science.gov (United States)

    1994-03-01

    One of the most widespread health problems in the Caribbean and Latin America is contaminated food and foodborne illness. The Pan American Health Organization (PAHO) has been a major force in activities to strengthen food protection. The program within the regional Program of Technical Cooperation is administered by the Veterinary Public Health program and under the guidance of the Pan American Institute for Food protection and Zoonoses in Buenos Aires, Argentina. A food action plan for 1986-90 was established at the 1986 Pan American Sanitary Conference, and extended to cover 1991-95. Program activities during the 1990s covered cholera, epidemiologic surveillance, street food vendors, shellfish poisoning, meat, national programs, information systems, air catering, food irradiation, and tourism. The action plan for 1991-95 promoted greater political support and cooperation within and between related sectors and institutions, management, and education. The aims were to organize national integrated programs, to strengthen laboratory services, to strengthen inspection services, to establish epidemiologic surveillance systems, and to promote food protection through community participation. Program activities included the initiatives of the Veterinary Public Health Program in 1991 to distribute literature on the transmission of cholera by foods. Studies were conducted in Bolivia, Colombia, and Peru on food contamination. Microbiologists received training on standard methods for detecting Vibrio cholerae in foods. A working group of experts from 10 countries examined the issues and produced a guide for investigating the incidence of foodborne disease. PAHO has contributed to the formation of an Inter-American Network for Epidemiologic Surveillance of Foodborne Diseases. PAHO has worked to improve hygienic practices among street food vendors. Seminars on paralytic shellfish poisoning were conducted in 1990; the outcome was a network working to strengthen national

  17. Pecan shell-based granular activated carbon for treatment of chemical oxygen demand (COD) in municipal wastewater.

    Science.gov (United States)

    Bansode, R R; Losso, J N; Marshall, W E; Rao, R M; Portier, R J

    2004-09-01

    The present investigation was undertaken to compare the adsorption efficiency of pecan shell-based granular activated carbon with the adsorption efficiency of the commercial carbon Filtrasorb 200 with respect to uptake of the organic components responsible for the chemical oxygen demand (COD) of municipal wastewater. Adsorption efficiencies for these two sets of carbons (experimental and commercial) were analyzed by the Freundlich adsorption model. The results indicate that steam-activated and acid-activated pecan shell-based carbons had higher adsorption for organic matter measured as COD, than carbon dioxide-activated pecan shell-based carbon or Filtrasorb 200 at all the carbon dosages used during the experiment. The higher adsorption may be related to surface area as the two carbons with the highest surface area also had the highest organic matter adsorption. These results show that granular activated carbons made from agricultural waste (pecan shells) can be used with greater effectiveness for organic matter removal from municipal wastewater than a coal-based commercial carbon. Copyright 2004 Elsevier Ltd.

  18. Superficial Velocity Effects on HZ-PAN and AgZ-PAN for Kr/Xe Capture

    Energy Technology Data Exchange (ETDEWEB)

    Welty, Amy Keil [Idaho National Lab. (INL), Idaho Falls, ID (United States); Garn, Troy Gerry [Idaho National Lab. (INL), Idaho Falls, ID (United States); Greenhalgh, Mitchell Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-04-01

    Nearly all previous testing of HZ-PAN and AgZ-PAN was conducted at the same flow rate in order to maintain consistency among tests. This testing was sufficient for sorbent capacity determinations, but did not ensure that sorbents were capable of functioning under a range of flow regimes. Tests were conducted on both HZ-PAN and AgZ-PAN at superficial velocities between 20 and 700 cm/min. For HZ-PAN, Kr capacity increased from 60 mmol/kg to 110 mmol/kg as superficial velocity increased from 21 to 679 cm/min. Results for AgZ-PAN were similar, with capacity ranging from 72 to 124 mmol/kg over the same range of superficial. These results are promising for scaling up to process flows, demonstrating flexibility to operate in a broad range of superficial velocities while maintaining sorbent capacity. While preparing for superficial velocity testing it was also discovered that AgZ-PAN Xe capacity, previously observed to diminish over time, could be recovered with increased desorption temperature. Further, a substantial Xe capacity increase was observed. Previous room temperature capacities in the range of 22-25 mmol Xe/kg AgZ-PAN were increased to over 60 mmol Xe/kg AgZ-PAN. While this finding has not yet been fully explored to optimize activation and desorption temperatures, it is encouraging.

  19. Form gene clustering method about pan-ethnic-group products based on emotional semantic

    Science.gov (United States)

    Chen, Dengkai; Ding, Jingjing; Gao, Minzhuo; Ma, Danping; Liu, Donghui

    2016-09-01

    The use of pan-ethnic-group products form knowledge primarily depends on a designer's subjective experience without user participation. The majority of studies primarily focus on the detection of the perceptual demands of consumers from the target product category. A pan-ethnic-group products form gene clustering method based on emotional semantic is constructed. Consumers' perceptual images of the pan-ethnic-group products are obtained by means of product form gene extraction and coding and computer aided product form clustering technology. A case of form gene clustering about the typical pan-ethnic-group products is investigated which indicates that the method is feasible. This paper opens up a new direction for the future development of product form design which improves the agility of product design process in the era of Industry 4.0.

  20. Preparation and performance of biofouling resistant PAN/chitosan hollow fiber membranes.

    Science.gov (United States)

    Shanthana Lakshmi, D; Jaiswar, Santlal; Saxena, Mayank; Tasselli, Franco; Raval, Hiren D

    2017-07-01

    The preparation of polyacrylonitrile (PAN) hollow fiber (HF) membranes has been carried out by dry-jet wet spinning. PAN HF membranes were coated with chitosan biopolymers 2 wt% by dip coating and further crosslinked by chemical reagents (Tri sodium polyphosphate). PAN HF (Virgin) and PAN/chitosan coated membrane were characterized by SEM and tested for water flux. Proteins Pepsin, Albumin, and Clay of 1000 ppm concentration were tested for separation efficiency. In addition, bacterial species Escherichia coli and Bacillus subtilis were tested for fouling control efficiency and found out that PAN/chitosan membranes were quite superior to virgin PAN fibers. The adhesion of bacterial cells on the surface of the hollow fiber membranes assessed through alcian blue staining and SEM analysis. It was observed that PAN/chitosan membranes (310A and 310C) possessed best antibacterial activities (based on SEM results), qualifying them as a very promising candidates for anti-biofouling coatings.

  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. PanCanadian Energy Corporation 2001 progress report : Voluntary challenge and registry Inc

    International Nuclear Information System (INIS)

    2001-10-01

    With extensive exploration and production activities stretching across Canada and reaching into the Gulf of Mexico, PanCanadian Energy Corporation is one of Canada's largest producers and marketers of crude oil, natural gas and natural gas liquids. PanCanadian is a committed supporter of the Climate Change Voluntary Challenge and Registry (VCR) program, whose aim is the reduction of greenhouse gas emissions. Through geological sequestration, improved operational efficiencies, research, public policy input, employee education, and regular reporting to external stakeholders, PanCanadian remains committed to greenhouse gas management. To date, the reductions amount to 2.5 million tonnes per year plus 103,000 net tonnes injected into the Weyburn project during 2000. The start-up of the Weyburn carbon dioxide injection project was the major focus of the efforts in 2000, along with improvements in the measurement processes used to prepare the reports. Assistance in the formulation of provincial and national strategies was provided. In section 1 of the document, a statement concerning senior management support was provided, and section 2 detailed the base year quantification. In section 3, the projection was discussed, followed by the targets in section 4. The measures to achieve targets were reviewed in section 5, and the results achieved were examined in section 6. Education, training and awareness were dealt with in section 7. 8 tabs., 3 figs

  3. Metallurgical and acoustical characterization of a hydroformed, 304 stainless steel, Caribbean-style musical pan

    International Nuclear Information System (INIS)

    Murr, L.E.; Gaytan, S.M.; Lopez, M.I.; Bujanda, D.E.; Martinez, E.Y.; Whitmyre, G.; Price, H.

    2008-01-01

    We report herein the metallurgical and acoustical characterization of hydroformed 304 stainless steel, Caribbean pans. These pans were fully tuned to chromatic tones and compared to a manufactured, low-carbon, Caribbean steel pan standard. Hydroformed platforms had a Vickers microindentation hardness of HV 345, which was reduced by annealing during pan fabrication to HV 270. Skirts welded to the hydroformed head had a microindentation hardness of HV 440. Microstructural characterization by light optical metallography and transmission electron microscopy illustrated microstructures (including grain structures) characteristic of these pan microindentation hardnesses

  4. Preparation and Characterization of Carbon Nanotubes-Based Composite Electrodes for Electric Double Layer Capacitors

    International Nuclear Information System (INIS)

    Seo, Min Kang; Park, Soo Jin

    2012-01-01

    In this work, we prepared activated multi-walled carbon nanotubes/polyacrylonitrile (A-MWCNTs/C) composites by film casting and activation method. Electrochemical properties of the composites were investigated in terms of serving as MWCNTs-based electrode materials for electric double layer capacitors (EDLCs). As a result, the A-MWCNTs/C composites had much higher BET specific surface area, and pore volume, and lower volume ratio of micropores than those of pristine MWCNTs/PAN ones. Furthermore, some functional groups were added on the surface of the A-MWCNTs/C composites. The specific capacitance of the A-MWCNTs/C composites was more than 4.5 times that of the pristine ones at 0.1 V discharging voltage owing to the changes of the structure and surface characteristics of the MWCNTs by activation process

  5. Optimization of Pan Bread Prepared with Ramie Powder and Preservation of Optimized Pan Bread Treated by Gamma Irradiation during Storage

    International Nuclear Information System (INIS)

    Lee, H.J.; Joo, N.M.

    2012-01-01

    This study was conducted to develop an optimal composite recipe for pan bread with ramie powder that has high sensory approval with all age groups and to estimate the DPPH radical scavenging activity and the pan bread shelf life after gamma irradiation. The sensory evaluation results showed significant differences in flavor (p less than 0.05), appearance (p less than 0.01), color (p less than 0.01), moistness (p less than 0.01), and overall quality (p less than 0.05) based on the amount of ramie powder added. As a result, the optimum formulations by numerical and graphical methods were calculated to be as follows: ramie powder 2.76 g (0.92%) and water 184.7 mL. Optimized pan bread with ramie powder and white pan bread were irradiated with gamma-rays at doses of 0, 10, 15, and 20 kGy. The total bacterial growth increased with the longer storage time and the least amount of ramie powder added. Consequently, these results suggest that the addition of ramie powder to pan bread provides added value to the bread in terms of increased shelf life

  6. Pan-pan Girls: Humiliating Liberation in Postwar Japanese Literature

    Directory of Open Access Journals (Sweden)

    Rumi Sakamoto

    2010-09-01

    Full Text Available This paper looks at some literary representations of the ‘pan-pan girls’ in postwar Japan. ‘Pan-pan’ is a derogatory term for street prostitutes who (mostly served the soldiers of the occupying forces. Immediately after World War II, the Japanese government established the RAA (Recreation Amusement Association and employed several thousand women to provide sexual services for foreign soldiers, ostensibly to protect Japanese women of middle and upper classes from rape and other violence. When the RAA was closed down in 1946 due to the US concern over widespread VD, many of the women who lost their jobs went out on the street and became private and illegal prostitutes – the pan-pan girls. With their red lipstick, cigarettes, nylon stockings and high-heel shoes, often holding onto the arms of tall, uniformed American GIs, the ‘pan-pan girls’ became a symbol of the occupation, and have been textually reproduced throughout the postwar period. This paper analyses the images and representations of the ‘pan-pan girls’ in postwar Japanese literature, to consider how the ‘pan-pan girls’ have functioned as a metaphor for the occupation and contributed to the public memory construction of the occupation. I identify some major codes of representations (victimisation, humiliation, and national trauma; eroticism and decadence; sexual freedom and materialism and argue that the highly gendered and sexualised bodies of the ‘pan-pan girls’ have continued to allow simplistic and selective remembering of the occupation at the expense of recalling the pivotal role of Japanese patriarchy in the postwar period.

  7. Enhanced CO2 Adsorption on Activated Carbon Fibers Grafted with Nitrogen-Doped Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Yu-Chun Chiang

    2017-05-01

    Full Text Available In this paper, multiscale composites formed by grafting N-doped carbon nanotubes (CNs on the surface of polyamide (PAN-based activated carbon fibers (ACFs were investigated and their adsorption performance for CO2 was determined. The spaghetti-like and randomly oriented CNs were homogeneously grown onto ACFs. The pre-immersion of cobalt(II ions for ACFs made the CNs grow above with a large pore size distribution, decreased the oxidation resistance, and exhibited different predominant N-functionalities after chemical vapor deposition processes. Specifically, the CNs grafted on ACFs with or without pre-immersion of cobalt(II ions were characterized by the pyridine-like structures of six-member rings or pyrrolic/amine moieties, respectively. In addition, the loss of microporosity on the specific surface area and pore volume exceeded the gain from the generation of the defects from CNs. The adsorption capacity of CO2 decreased gradually with increasing temperature, implying that CO2 adsorption was exothermic. The adsorption capacities of CO2 at 25 °C and 1 atm were between 1.53 and 1.92 mmol/g and the Freundlich equation fit the adsorption data well. The isosteric enthalpy of adsorption, implying physical adsorption, indicated that the growth of CNTs on the ACFs benefit CO2 adsorption.

  8. Lactobacillus brevis-based bioingredient inhibits Aspergillus niger growth on pan bread

    Directory of Open Access Journals (Sweden)

    Mariaelena Di Biase

    2014-11-01

    Full Text Available Bread shelf life is generally compromised by fungi mainly belonging to Aspergillus and Penicillium genera, which colonise the surface of the product within few days from the production. The aim of this study was to select a Lactobacillus brevis-based bioingredient (LbBio able to inhibit the growth of Aspergillus niger ITEM5132 on pan bread in order to prolong its shelf life. Four LbBio formulations, obtained by growing a selected L. brevis strain in a flour-based medium containing different carbon sources or acid precursors (fructose, LbBio1; fructose and maltose, LbBio2; α-chetoglutaric acid, LbBio3; short-chain fructooligosaccharides, LbBio4, were evaluated for their content of organic acids (lactic, acetic, propionic, phenyllactic, 4-hydroxy-phenyllactic, valeric, isovaleric acids. The LbBio formulations were applied in yeast-leavened bread during bread-making trials and the resulting products were inoculated after baking with A. niger spore’s suspension and the fungal growth was monitored during storage (25°C for 6 days. The formulation showing the highest inhibitory activity was separated by ultra-filtration method, and whole and fractions obtained were evaluated for their in vitro activity. The fraction showing the highest activity was further separated by gel-filtration and the resulting products were investigated for their protein content and in vitro inhibition. The results from the bread-making trials performed using different formulations of LbBio showed a delay in fungal growth (1 day respect to the bread not containing the bioingredient (control or including calcium propionate (0.3% w/w. The formulation LbBio2, prepared with fructose and maltose 1% (w/vol, contained the highest amount of total organic acids, including phenyllactic and hydroxyl-phenyllactic acids, and reduced the visual spoilage of bread. This formulation was separated by ultra-filtration and fractions containing metabolites with molecular weight higher than 30 k

  9. Study on adsorption performance of coal based activated carbon to radioactive iodine and stable iodine

    International Nuclear Information System (INIS)

    Zhou, Junbo; Hao, Shan; Gao, Liping; Zhang, Youchen

    2014-01-01

    Highlights: • The impregnated coal-based activated carbons as adsorbent for removing methyl iodide. • The coal-based activated carbons to remove stable iodine. • Iodine residues are under 0.5 μg/ml after adsorption treatment. • The decontamination factor is much higher than 1000. - Abstract: Nuclear power plant, nuclear reactors and nuclear powered ship exhaust contains a large amount of gaseous radioactive iodine, and can damage to the workplace and the surrounding environment. The quantitative test to remove methyl iodide and the qualitative test for removing stable iodine were investigated using the impregnated coal-based activated carbons and coal-based activated carbons as adsorbents. The research conducted in this work shows that iodine residues were under 0.5 μg/ml after adsorption treatment and the decontamination factor of the coal-based activated carbon for removing the stable iodine was more than 1000, which can achieve the purpose of removing harmful iodine, and satisfy the requirement of gaseous waste treatment of nuclear powered vessel and other nuclear plants

  10. Nanocomposites based on hierarchical porous carbon fiber@vanadium nitride nanoparticles as supercapacitor electrodes.

    Science.gov (United States)

    Ran, Fen; Wu, Yage; Jiang, Minghuan; Tan, Yongtao; Liu, Ying; Kong, Lingbin; Kang, Long; Chen, Shaowei

    2018-03-28

    In this study, a hybrid electrode material for supercapacitors based on hierarchical porous carbon fiber@vanadium nitride nanoparticles is fabricated using the method of phase-separation mediated by the PAA-b-PAN-b-PAA tri-block copolymer. In the phase-separation procedure, the ionic block copolymer self-assembled on the surface of carbon nanofibers, and is used to adsorb NH 4 VO 3 . Thermal treatment at controlled temperatures under an NH 3  : N 2 atmosphere led to the formation of vanadium nitride nanoparticles that are distributed uniformly on the nanofiber surface. By changing the PAN to PAA-b-PAN-b-PAA ratio in the casting solution, a maximum specific capacitance of 240.5 F g -1 is achieved at the current density of 0.5 A g -1 with good rate capability at a capacitance retention of 72.1% at 5.0 A g -1 in an aqueous electrolyte of 6 mol L -1 KOH within the potential range of -1.10 to 0 V (rN/A = 1.5/1.0). Moreover, an asymmetric supercapacitor is assembled by using the hierarchical porous carbon fiber@vanadium nitride as the negative electrode and Ni(OH) 2 as the positive electrode. Remarkably, at the power density of 400 W kg -1 , the supercapacitor device delivers a better energy density of 39.3 W h kg -1 . It also shows excellent electrochemical stability, and thus might be used as a promising energy-storage device.

  11. The Effect of CO2 Activation on the Electrochemical Performance of Coke-Based Activated Carbons for Supercapacitors.

    Science.gov (United States)

    Lee, Hye-Min; Kim, Hong-Gun; An, Kay-Hyeok; Kim, Byung-Joo

    2015-11-01

    The present study developed electrode materials for supercapacitors by activating coke-based activated carbons with CO2. For the activation reaction, after setting the temperature at 1,000 degrees C, four types of activated carbons were produced, over an activation time of 0-90 minutes and with an interval of 30 minutes as the unit. The electrochemical performance of the activated carbons produced was evaluated to examine the effect of CO2 activation. The surface structure of the porous carbons activated through CO2 activation was observed using a scanning electron microscope (SEM). To determine the N2/77 K isothermal adsorption characteristics, the Brunauer-Emmett-Teller (BET) equation and the Barrett-Joyner-Halenda (BJH) equation were used to analyze the pore characteristics. In addition, charge and discharge tests and cyclic voltammetry (CV) were used to analyze the electrochemical characteristics of the changed pore structure. According to the results of the experiments, the N2 adsorption isotherm curves of the porous carbons produced belonged to Type IV in the International Union of Pore and Applied Chemistry (IUPAC) classification and consisted of micropores and mesopores, and, as the activation of CO2 progressed, micropores decreased and mesopores developed. The specific surface area of the porous carbons activated by CO2 was 1,090-1,180 m2/g and thus showed little change, but those of mesopores were 0.43-0.85 cm3/g, thus increasing considerably. In addition, when the electrochemical characteristics were analyzed, the specific capacity was confirmed to have increased from 13.9 F/g to 18.3 F/g. From these results, the pore characteristics of coke-based activated carbons changed considerably because of CO2 activation, and it was therefore possible to increase the electrochemical characteristics.

  12. Analyses of the soil surface dynamic of South African Kalahari salt pans based on hyperspectral and multitemporal data

    Science.gov (United States)

    Milewski, Robert; Chabrillat, Sabine; Behling, Robert; Mielke, Christian; Schleicher, Anja Maria; Guanter, Luis

    2016-04-01

    -reweighted Multivariate Alteration Detection (iMAD) method to identify and investigate surface changes based on Landsat archive imagery covering the period 1984-2015. For the complete Landsat time series, a total of 130 bi-temporal change maps have been derived and are compiled to produce a change magnitude map, which indicates different regions of activity and stability of the pan surface. Then radiometric geometric and atmospheric correction of Hyperion data were performed using the pre-processing chain of Rogass et al. (2014). Based on field spectroscopy and XRD analysis of soil samples, one of the main evaporite minerals of the pan soil could be identified as gypsum. Different approaches based on spectral features were tested and validated against reference samples to find the most suitable approach for estimating the gypsum content from the Hyperion data. Major challenges were the influence of water vapour absorption bands close to major gypsum absorption feature as well as low signal-to-noise ratio of Hyperion in the SWIR wavelength. A best method was determined that allow to determine Gypsum content with R² of 0.7 and relative RMSE of 0.14. Results reveal a variable spatial distribution of different mineralogy and in particular gypsum content within the pan, which seems to be associated with varying dynamic of the pan surface.

  13. Nitrogen-Rich Polyacrylonitrile-Based Graphitic Carbons for Hydrogen Peroxide Sensing

    Directory of Open Access Journals (Sweden)

    Brandon Pollack

    2017-10-01

    Full Text Available Catalytic substrate, which is devoid of expensive noble metals and enzymes for hydrogen peroxide (H2O2, reduction reactions can be obtained via nitrogen doping of graphite. Here, we report a facile fabrication method for obtaining such nitrogen doped graphitized carbon using polyacrylonitrile (PAN mats and its use in H2O2 sensing. A high degree of graphitization was obtained with a mechanical treatment of the PAN fibers embedded with carbon nanotubes (CNT prior to the pyrolysis step. The electrochemical testing showed a limit of detection (LOD 0.609 µM and sensitivity of 2.54 µA cm−2 mM−1. The promising sensing performance of the developed carbon electrodes can be attributed to the presence of high content of pyridinic and graphitic nitrogens in the pyrolytic carbons, as confirmed by X-ray photoelectron spectroscopy. The reported results suggest that, despite their simple fabrication, the hydrogen peroxide sensors developed from pyrolytic carbon nanofibers are comparable with their sophisticated nitrogen-doped graphene counterparts.

  14. Structural stability of PAN fiber under high electron beam radiation doses

    International Nuclear Information System (INIS)

    Pino, Eddy S.; Machado, Luci D.B.; Arruda, Clarissa P. Zelinschi de; Carvalho, Alvaro A. Silva de; Giovedi, Claudia

    2009-01-01

    Fiber-reinforced composite are an important class of engineering material. A relevant task of composite technology in order to produce materials for structures of high mechanical performance is to obtain the best carbon fiber. One of the main ways to produce carbon fibers of high Young's modulus and tensile strength is to use as starting material polyacrylonitrile (PAN) fibers which after a rigorous and carefully thermal process become carbon fibers. Since some chemical modifications produced in the thermal treatment can be induced by ionizing radiation, the aim of this paper is to evaluate the effect of high electron beam (EB) doses on a commercial PAN fiber in order to evaluate the use of this technology as an alternative treatment to improve the properties and characteristics of the produced carbon fiber. The doses applied were: 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 MGy. The irradiation effects induced on the PAN fiber were evaluated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetry (TG). FTIR obtained data have shown that the main functional groups remain practically unchanged in the non-irradiated and irradiated samples. The single DSC exothermic peak obtained for non-irradiated sample, becomes a double peak after the irradiation, presenting lower initial and higher final temperatures for exothermic DSC curves. The enthalpy involved in the chemical reaction decreases for irradiated samples as compared with the non-irradiated PAN fiber. TG data have shown that irradiated samples start a decomposition process at lower temperatures compared to the non-irradiated sample. (author)

  15. High Mass-Loading of Sulfur-Based Cathode Composites and Polysulfides Stabilization for Rechargeable Lithium/Sulfur Batteries

    International Nuclear Information System (INIS)

    Hara, Toru; Konarov, Aishuak; Mentbayeva, Almagul; Kurmanbayeva, Indira; Bakenov, Zhumabay

    2015-01-01

    Although sulfur has a high theoretical gravimetric capacity, 1672 mAh/g, its insulating nature requires a large amount of conducting additives: this tends to result in a low mass-loading of active material (sulfur), and thereby, a lower capacity than expected. Therefore, an optimal choice of conducting agents and of the method for sulfur/conducting-agent integration is critically important. In this paper, we report that the areal capacity of 4.9 mAh/cm 2 was achieved at sulfur mass loading of 4.1 mg/cm 2 by casting sulfur/polyacrylonitrile/ketjenblack (S/PAN/KB) cathode composite into carbon fiber paper. This is the highest value among published/reported ones even though it does not contain expensive nanosized carbon materials such as carbon nanotubes, graphene, or graphene derivatives, and competitive enough with the conventional LiCoO 2 -based cathodes (e.g., LiCoO 2 , <20 mg/cm 2 corresponding to <2.8 mAh/cm 2 ). Furthermore, the combination of sulfur/PAN-based composite and PAN-based carbon fiber paper enabled the sulfur-based composite to be used even in carbonate-based electrolyte solution that many lithium/sulfur battery researchers avoid the use of it because of severer irreversible active material loss than in electrolyte solutions without carbonate-based solutions, and even at the highest mass-loading ever reported (the more sulfur is loaded, the more decomposed sulfides deposit at an anode surface).

  16. 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)

  17. Tobacco Stem-Based Activated Carbons for High Performance Supercapacitors

    Science.gov (United States)

    Xia, Xiaohong; Liu, Hongbo; Shi, Lei; He, Yuede

    2012-09-01

    Tobacco stem-based activated carbons (TS-ACs) were prepared by simple KOH activation and their application as electrodes in the electrical double layer capacitor (EDLC) performed successfully. The BET surface area, pore volume, and pore size distribution of the TS-ACs were evaluated based on N2 adsorption isotherms at 77 K. The surface area of the obtained activated carbons varies over a wide range (1472.8-3326.7 m2/g) and the mesoporosity was enhanced significantly as the ratio of KOH to tobacco stem (TS) increased. The electrochemical behaviors of series TS-ACs were characterized by means of galvanostatic charging/discharging, cyclic voltammetry, and impedance spectroscopy. The correlation between electrochemical properties and pore structure was investigated. A high specific capacitance value as 190 F/g at 1 mA/cm2 was obtained in 1 M LiPF6-EC/DMC/DEC electrolyte solution. Furthermore, good performance is also achieved even at high current densities. A development of new use for TS into a valuable energy storage material is explored.

  18. Effect of carbon microfiber materials on sensitivity of adenosine and hydroxyadenine at carbon microfiber sensors

    Directory of Open Access Journals (Sweden)

    K.M.M. Abou El-Nour

    2015-07-01

    Full Text Available The relationship between the sensitivity measurements and microfiber electrodes made from different carbon microfiber materials, such as polyacrylonitrile (PAN T650 and PAN HCB and Pitch P25 was established in this work. The different microfiber electrodes were nanostructured by an electrochemical pretreatment method. Sensitivity of adenosine (ADO and 2,8-dihydroxyadenine (2,8-DHA was measured at different carbon microfiber sensors made from different carbon microfiber materials. Sensitivity of PAN microfiber electrodes for ADO and 2,8-DHA determinations measured at 500 V s−1 vs. SCE is higher than that measured at Pitch P25 microfiber electrodes due to more defects in PAN microfiber electrodes. Adsorption of ADO and 2,8-DHA is greater at PAN HCB electrodes. High conductivity of PAN fibers correlates with sensitivity determinations of the investigated analytes.

  19. Pan Eurasian EXperiment (PEEX) - towards a new multinational environment and climate research effort in Eurasia

    Science.gov (United States)

    Petäjä, Tuukka; Kulmala, Markku; Lappalainen, Hanna; Sipilä, Mikko; Sorvari, Sanna; Alekseychik, Pavel; Paramonov, Mikhail; Kerminen, Veli-Matti; Zilitinkevich, Sergej

    2013-04-01

    Boreal forests are a substantial source of greenhouse gases, biogenic volatile organic compounds (BVOCs) and natural aerosols, the critical atmospheric components related to climate change processes. A large fraction of boreal forests of the world is situated in Siberian region. Representative measurements of carbon dioxide (CO2) and methane (CH4) concentrations, BVOC emissions and aerosols production from Siberian are of special importance when estimating global budgets of climate change relevant factors. The scope of a new concept of the Pan Eurasian Experiment (PEEX) is to set up a process for planning of a large-scale, long-term, coordinated observations and modeling experiment in the Pan Eurasian region, especially to cover ground base, airborne and satellite observations together with global and regional models to find out different forcing and feedback mechanisms in the changing climate. University of Helsinki together with Finnish Meteorological institute are organizing the Pan-Eurasian Experiment and to gather all the European and Russian key players in the field of climate and Earth system science to plan the future research activities in the Pan-Eurasian region. In the European scale PEEX is part of the JPI Climate Fast Track Activity 1.3. "Changing cryosphere in the climate system - from observations to climate modeling". PEEX research topics are closely related the NordForsk's Top Research Initiative CRAICC - Cryosphere - atmosphere interaction in the changing Arctic climate. PEEX is also a central part of the ongoing the Finnish Cultural Foundation - Earth System modeling Working Group activity (2012-2013). PEEX scientific aims and future actions to develop Pan Eurasian research infrastructure can be linked to several EC and ESA funded activities aiming to develop next generation research infrastructures and data products: EU-FP7-ACTRIS-I3-project (Aerosols, Clouds, and Trace gases Research InfraStructure Network-project 2011-2015); ICOS a research

  20. Physical and chemical properties of selected agricultural byproduct-based activated carbons and their ability to adsorb geosmin

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.; Losso, J.N.; Rao, R.M. [Louisiana State University Agricultural Center, Baton Rouge, LA (United States). Department of Food Science; Marshall, W.E. [USDA-ARS, Southern Regional Research Center, New Orleans, LA (United States)

    2002-09-01

    The objectives of this study were to evaluate selected physical and chemical properties of agricultural byproduct-based activated carbons made from pecan shells and sugarcane bagasse, and compare those properties to a commercial coal-based activated carbon as well as to compare the adsorption efficiency of these carbons for geosmin. Comparison of the physical and chemical properties of pecan shell- and bagasse-based carbons to the commercial carbon, Calgon Filtrasorb 400, showed that pecan shell carbon, but not the bagasse carbon, compared favorably to Filtrasorb 400, especially in terms of surface area, bulk density, ash and attrition. A carbon dosage study done in a model system showed the amount of geosmin adsorbed to be greater for Filtrasorb 400 and the bagasse-based carbon at low carbon concentrations than for the pecan shell carbons, but geosmin adsorption was similar in all carbons at higher carbon dosages. Application of the Freundlich isotherm model to the adsorption data showed that carbons made by steam activation of pecan shells or sugarcane bagasse had geosmin adsorption characteristics most like those of the commercial carbon. In terms of physical, chemical and adsorptive properties, steam-activated pecan shell carbon most resembled the commercial carbon and has the potential to replace Filtrasorb 400 in applications involving removal of geosmin from aqueous environments. (author)

  1. Catalytic and peroxidase-like activity of carbon based-AuPd bimetallic nanocomposite produced using carbon dots as the reductant

    International Nuclear Information System (INIS)

    Yang, Liuqing; Liu, Xiaoying; Lu, Qiujun; Huang, Na; Liu, Meiling; Zhang, Youyu; Yao, Shouzhuo

    2016-01-01

    In this report, carbon-based AuPd bimetallic nanocomposite (AuPd/C NC) was synthesized using carbon dots (C-dots) as the reducing agent and stabilizer by a simple green sequential reduction strategy, without adding other agents. The as synthesized AuPd/C NC showed good catalytic activity and peroxidase-like property. The structure and morphology of these nanoparticles were clearly characterized by UV–Vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The AuPd/C NC catalyst exhibits noticeably higher catalytic activity than Pd and Au nanoparticles in catalysis reduction of 4-nitrophenol (4-NP). Moreover, based on the high peroxidase-like property of AuPd/C NC, a new colorimetric detection method for hydrogen peroxide (H 2 O 2 ) has been designed using 3,3′,5,5′-tetramethyl-benzidine (TMB) as the substrate, which provides a simple and sensitive means to detect H 2 O 2 in wide linear range of 5 μM–500 μM and 500 μM–4 mM with low detection limit of 1.6 μM (S/N = 3). Therefore, the facile synthesis strategy for bimetallic nanoparticles by the mild reductant of carbon dot will provide some new thoughts for preparing of carbon-based metal nanomaterials and expand their application in catalysis and analytical chemistry areas. - Highlights: • Carbon-based AuPd bimetallic nanocomposite was synthesized using carbon dots. • The green sequential reduction strategy synthesis method is simple, green, convenient and effective. • The as synthesized AuPd/C NC showed good catalytic activity and peroxidase-like activity. • The AuPd/C NC exhibits noticeably higher catalytic activity in reduction of 4-nitrophenol. • A new colorimetric detection method for hydrogen peroxide based on AuPd/C NC was proposed.

  2. Catalytic and peroxidase-like activity of carbon based-AuPd bimetallic nanocomposite produced using carbon dots as the reductant

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liuqing [Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081 (China); Liu, Xiaoying [College of Science, Science and Technological Innovation Platform, Hunan Agricultural University, Hunan, Changsha 410128 (China); Lu, Qiujun; Huang, Na [Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081 (China); Liu, Meiling, E-mail: liumeilingww@126.com [Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081 (China); Zhang, Youyu; Yao, Shouzhuo [Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education, China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081 (China)

    2016-08-03

    In this report, carbon-based AuPd bimetallic nanocomposite (AuPd/C NC) was synthesized using carbon dots (C-dots) as the reducing agent and stabilizer by a simple green sequential reduction strategy, without adding other agents. The as synthesized AuPd/C NC showed good catalytic activity and peroxidase-like property. The structure and morphology of these nanoparticles were clearly characterized by UV–Vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The AuPd/C NC catalyst exhibits noticeably higher catalytic activity than Pd and Au nanoparticles in catalysis reduction of 4-nitrophenol (4-NP). Moreover, based on the high peroxidase-like property of AuPd/C NC, a new colorimetric detection method for hydrogen peroxide (H{sub 2}O{sub 2}) has been designed using 3,3′,5,5′-tetramethyl-benzidine (TMB) as the substrate, which provides a simple and sensitive means to detect H{sub 2}O{sub 2} in wide linear range of 5 μM–500 μM and 500 μM–4 mM with low detection limit of 1.6 μM (S/N = 3). Therefore, the facile synthesis strategy for bimetallic nanoparticles by the mild reductant of carbon dot will provide some new thoughts for preparing of carbon-based metal nanomaterials and expand their application in catalysis and analytical chemistry areas. - Highlights: • Carbon-based AuPd bimetallic nanocomposite was synthesized using carbon dots. • The green sequential reduction strategy synthesis method is simple, green, convenient and effective. • The as synthesized AuPd/C NC showed good catalytic activity and peroxidase-like activity. • The AuPd/C NC exhibits noticeably higher catalytic activity in reduction of 4-nitrophenol. • A new colorimetric detection method for hydrogen peroxide based on AuPd/C NC was proposed.

  3. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

    Khavarian, Mehrnoush; Chai, Siang-Piao; Mohamed, Abdul Rahman

    2013-07-01

    The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity.

  4. 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).

  5. Hierarchical activated mesoporous phenolic-resin-based carbons for supercapacitors.

    Science.gov (United States)

    Wang, Zhao; Zhou, Min; Chen, Hao; Jiang, Jingui; Guan, Shiyou

    2014-10-01

    A series of hierarchical activated mesoporous carbons (AMCs) were prepared by the activation of highly ordered, body-centered cubic mesoporous phenolic-resin-based carbon with KOH. The effect of the KOH/carbon-weight ratio on the textural properties and capacitive performance of the AMCs was investigated in detail. An AMC prepared with a KOH/carbon-weight ratio of 6:1 possessed the largest specific surface area (1118 m(2) g(-1)), with retention of the ordered mesoporous structure, and exhibited the highest specific capacitance of 260 F g(-1) at a current density of 0.1 A g(-1) in 1 M H2 SO4 aqueous electrolyte. This material also showed excellent rate capability (163 F g(-1) retained at 20 A g(-1)) and good long-term electrochemical stability. This superior capacitive performance could be attributed to a large specific surface area and an optimized micro-mesopore structure, which not only increased the effective specific surface area for charge storage but also provided a favorable pathway for efficient ion transport. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Antitumor activity of pan-HER inhibitors in HER2-positive gastric cancer.

    Science.gov (United States)

    Yoshioka, Takahiro; Shien, Kazuhiko; Namba, Kei; Torigoe, Hidejiro; Sato, Hiroki; Tomida, Shuta; Yamamoto, Hiromasa; Asano, Hiroaki; Soh, Junichi; Tsukuda, Kazunori; Nagasaka, Takeshi; Fujiwara, Toshiyoshi; Toyooka, Shinichi

    2018-04-01

    Molecularly targeted therapy has enabled outstanding advances in cancer treatment. Whereas various anti-human epidermal growth factor receptor 2 (HER2) drugs have been developed, trastuzumab is still the only anti-HER2 drug presently available for gastric cancer. In this study, we propose novel treatment options for patients with HER2-positive gastric cancer. First, we determined the molecular profiles of 12 gastric cancer cell lines, and examined the antitumor effect of the pan-HER inhibitors afatinib and neratinib in those cell lines. Additionally, we analyzed HER2 alteration in 123 primary gastric cancers resected from Japanese patients to clarify possible candidates with the potential to respond to these drugs. In the drug sensitivity analysis, both afatinib and neratinib produced an antitumor effect in most of the HER2-amplified cell lines. However, some cells were not sensitive to the drugs. When the molecular profiles of the cells were compared based on the drug sensitivities, we found that cancer cells with lower mRNA expression levels of IGFBP7, a tumor suppressor gene that inhibits the activation of insulin-like growth factor-1 receptor (IGF-1R), were less sensitive to pan-HER inhibitors. A combination therapy consisting of pan-HER inhibitors and an IGF-1R inhibitor, picropodophyllin, showed a notable synergistic effect. Among 123 clinical samples, we found 19 cases of HER2 amplification and three cases of oncogenic mutations. In conclusion, afatinib and neratinib are promising therapeutic options for the treatment of HER2-amplified gastric cancer. In addition to HER2 amplification, IGFBP7 might be a biomarker of sensitivity to these drugs, and IGF-1R-targeting therapy can overcome drug insensitiveness in HER2-amplified gastric cancer. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  7. Performance of electrodes synthesized with polyacrylonitrile-based carbon nanofibers for application in electrochemical sensors and biosensors.

    Science.gov (United States)

    Adabi, Mahdi; Saber, Reza; Faridi-Majidi, Reza; Faridbod, Farnoush

    2015-03-01

    The purpose of this work was to investigate the performance of electrodes synthesized with Polyacrylonitrile-based carbon nanofibers (PAN-based CNFs). The homogenous PAN solutions with different concentrations were prepared and electrospun to acquire PAN nanofibers and then CNFs were fabricated by heat treatment. The effective parameters for the production of electrospun CNF electrode were investigated. Scanning electron microscopy (SEM) was used to characterize electrospun nanofibers. Cyclic voltammetry was applied to investigate the changes of behavior of electrospun CNF electrodes with different diameters. The structure of CNFs was also evaluated via X-ray diffraction (XRD) and Raman spectroscopy. The results exhibited that diameter of nanofibers reduced with decreasing polymer concentration and applied voltage and increasing tip-to-collector distance, while feeding rate did not have significant effect on nanofiber diameter. The investigations of electrochemical behavior also demonstrated that cyclic voltammetric response improved as diameter of CNFs electrode decreased. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Experience with ATLAS MySQL PanDA database service

    International Nuclear Information System (INIS)

    Smirnov, Y; Wlodek, T; Hover, J; Smith, J; Wenaus, T; Yu, D; De, K; Ozturk, N

    2010-01-01

    The PanDA distributed production and analysis system has been in production use for ATLAS data processing and analysis since late 2005 in the US, and globally throughout ATLAS since early 2008. Its core architecture is based on a set of stateless web services served by Apache and backed by a suite of MySQL databases that are the repository for all PanDA information: active and archival job queues, dataset and file catalogs, site configuration information, monitoring information, system control parameters, and so on. This database system is one of the most critical components of PanDA, and has successfully delivered the functional and scaling performance required by PanDA, currently operating at a scale of half a million jobs per week, with much growth still to come. In this paper we describe the design and implementation of the PanDA database system, its architecture of MySQL servers deployed at BNL and CERN, backup strategy and monitoring tools. The system has been developed, thoroughly tested, and brought to production to provide highly reliable, scalable, flexible and available database services for ATLAS Monte Carlo production, reconstruction and physics analysis.

  9. Experience with ATLAS MySQL PanDA database service

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Y; Wlodek, T; Hover, J; Smith, J; Wenaus, T; Yu, D [Physics Department, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); De, K; Ozturk, N [Department of Physics, University of Texas at Arlington, Arlington, TX, 76019 (United States)

    2010-04-01

    The PanDA distributed production and analysis system has been in production use for ATLAS data processing and analysis since late 2005 in the US, and globally throughout ATLAS since early 2008. Its core architecture is based on a set of stateless web services served by Apache and backed by a suite of MySQL databases that are the repository for all PanDA information: active and archival job queues, dataset and file catalogs, site configuration information, monitoring information, system control parameters, and so on. This database system is one of the most critical components of PanDA, and has successfully delivered the functional and scaling performance required by PanDA, currently operating at a scale of half a million jobs per week, with much growth still to come. In this paper we describe the design and implementation of the PanDA database system, its architecture of MySQL servers deployed at BNL and CERN, backup strategy and monitoring tools. The system has been developed, thoroughly tested, and brought to production to provide highly reliable, scalable, flexible and available database services for ATLAS Monte Carlo production, reconstruction and physics analysis.

  10. Facile preparation of nitrogen-doped hierarchical porous carbon with high performance in supercapacitors

    International Nuclear Information System (INIS)

    Yan, Kun; Kong, Ling-Bin; Shen, Kui-Wen; Dai, Yan-Hua; Shi, Ming; Hu, Bing; Luo, Yong-Chun; Kang, Long

    2016-01-01

    Graphical abstract: Preparing and activating process of nitrogen-doped hierarchical porous carbon (NHPC). - Highlights: • The well-defined PAN-b-PMMA copolymer was synthesized by atom transfer radical polymerization with narrow molecular weight distribution. • Nitrogen-doped hierarchical porous structure (NHPC) was prepared through a simple carbonization procedure of PAN-b-PMMA precursor. • NHPC possessed hierarchical porous structure with high BET surface area of 257 m"2 g"−"1 and DFT mesopore size of 14.61 nm. • Effects of activation conditions on supercapacitive behavior were systematically studied. - Abstract: The nitrogen-doped hierarchical porous carbon (NHPC) material was successfully prepared through a simple carbonization procedure of well-defined diblock copolymer precursor containing nitrogen-enriched carbon source, i.e., polyacrylonitrile (PAN), and asacrificial block, i.e., polymethylmethacrylate (PMMA). PAN-b-PMMA diblock copolymer was synthesized by atom transfer radical polymeriation (ATRP) with narrow molecular weight distribution. The as-obtained NHPC possessed nitrogen-doped hierarchical porous structure with high BET surface area of 257 m"2 g"−"1 and Nonlocal density functional theory (NLDFT) mesopore size of 14.61 nm. Surface activated nitrogen-doped hierarchical porous carbon (A-NHPC) materials were obtained by subsequent surface activation with HNO_3 solution. The effects of activation conditions on supercapacitive behavior were systematically studied, a maximum specific capacitance of 314 F g"−"1 at a current density of 0.5 A g"−"1 was achieved in 2 M KOH aqueous electrolyte. Simultaneously, it exhibited excellent rate capability of 67.8% capacitance retention as the current density increased from 0.5 to 20 A g"−"1 and superior cycling performance of 90% capacitance retention after 10,000 cycles at the current density of 2 A g"−"1.

  11. Facile preparation of nitrogen-doped hierarchical porous carbon with high performance in supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Kun [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); Kong, Ling-Bin, E-mail: konglb@lut.cn [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China); Shen, Kui-Wen; Dai, Yan-Hua; Shi, Ming; Hu, Bing [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); Luo, Yong-Chun; Kang, Long [School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China)

    2016-02-28

    Graphical abstract: Preparing and activating process of nitrogen-doped hierarchical porous carbon (NHPC). - Highlights: • The well-defined PAN-b-PMMA copolymer was synthesized by atom transfer radical polymerization with narrow molecular weight distribution. • Nitrogen-doped hierarchical porous structure (NHPC) was prepared through a simple carbonization procedure of PAN-b-PMMA precursor. • NHPC possessed hierarchical porous structure with high BET surface area of 257 m{sup 2} g{sup −1} and DFT mesopore size of 14.61 nm. • Effects of activation conditions on supercapacitive behavior were systematically studied. - Abstract: The nitrogen-doped hierarchical porous carbon (NHPC) material was successfully prepared through a simple carbonization procedure of well-defined diblock copolymer precursor containing nitrogen-enriched carbon source, i.e., polyacrylonitrile (PAN), and asacrificial block, i.e., polymethylmethacrylate (PMMA). PAN-b-PMMA diblock copolymer was synthesized by atom transfer radical polymeriation (ATRP) with narrow molecular weight distribution. The as-obtained NHPC possessed nitrogen-doped hierarchical porous structure with high BET surface area of 257 m{sup 2} g{sup −1} and Nonlocal density functional theory (NLDFT) mesopore size of 14.61 nm. Surface activated nitrogen-doped hierarchical porous carbon (A-NHPC) materials were obtained by subsequent surface activation with HNO{sub 3} solution. The effects of activation conditions on supercapacitive behavior were systematically studied, a maximum specific capacitance of 314 F g{sup −1} at a current density of 0.5 A g{sup −1} was achieved in 2 M KOH aqueous electrolyte. Simultaneously, it exhibited excellent rate capability of 67.8% capacitance retention as the current density increased from 0.5 to 20 A g{sup −1} and superior cycling performance of 90% capacitance retention after 10,000 cycles at the current density of 2 A g{sup −1}.

  12. Fuel and energy saving in open pan furnace used in jaggery making through modified juice boiling/concentrating pans

    International Nuclear Information System (INIS)

    Anwar, S.I.

    2010-01-01

    In this paper the concept of fins has been used for heating purpose for improving efficiency of open pan jaggery making furnace. Pan is the integral part of these furnaces where boiling/concentration of sugarcane juice take place. Parallel fins were provided to the bottom of main pan and gutter pan of IISR Lucknow 2-pan furnace. Choice for type of fins was based on movement of flames and hot flue gases generated due to combustion of bagasse. Fins helped in more heat transfer to the sugarcane juice being concentrated. Considerable improvement in heat utilization efficiency (9.44%) was observed which resulted in saving of fuel and energy (31.34%).

  13. Oxygen reduction activity of N-doped carbon-based films prepared by pulsed laser deposition

    Science.gov (United States)

    Hakoda, Teruyuki; Yamamoto, Shunya; Kawaguchi, Kazuhiro; Yamaki, Tetsuya; Kobayashi, Tomohiro; Yoshikawa, Masahito

    2010-12-01

    Carbon-based films with nitrogen species on their surface were prepared on a glassy carbon (GC) substrate for application as a non-platinum cathode catalyst for polymer electrolyte fuel cells. Cobalt and carbon were deposited in the presence of N 2 gas using a pulsed laser deposition method and then the metal Co was removed by HCl-washing treatment. Oxygen reduction reaction (ORR) activity was electrochemically determined using a rotating disk electrode system in which the film samples on the GC substrate were replaceable. The ORR activity increased with the temperature of the GC substrate during deposition. A carbon-based film prepared at 600 °C in the presence of N 2 at 66.7 Pa showed the highest ORR activity among the tested samples (0.66 V vs. NHE). This film was composed of amorphous carbons doped with pyridine type nitrogen atoms on its surface.

  14. Microstructure and surface properties of lignocellulosic-based activated carbons

    Science.gov (United States)

    González-García, P.; Centeno, T. A.; Urones-Garrote, E.; Ávila-Brande, D.; Otero-Díaz, L. C.

    2013-01-01

    Low cost activated carbons have been produced via chemical activation, by using KOH at 700 °C, from the bamboo species Guadua Angustifolia and Bambusa Vulgaris Striata and the residues from shells of the fruits of Castanea Sativa and Juglans Regia as carbon precursors. The scanning electron microscopy micrographs show the conservation of the precursor shape in the case of the Guadua Angustifolia and Bambusa Vulgaris Striata activated carbons. Transmission electron microscopy analyses reveal that these materials consist of carbon platelet-like particles with variable length and thickness, formed by highly disordered graphene-like layers with sp2 content ≈ 95% and average mass density of 1.65 g/cm3 (25% below standard graphite). Textural parameters indicate a high porosity development with surface areas ranging from 850 to 1100 m2/g and average pore width centered in the supermicropores range (1.3-1.8 nm). The electrochemical performance of the activated carbons shows specific capacitance values at low current density (1 mA/cm2) as high as 161 F/g in the Juglans Regia activated carbon, as a result of its textural parameters and the presence of pseudocapacitance derived from surface oxygenated acidic groups (mainly quinones and ethers) identified in this activated carbon.

  15. Neutron scattering investigation of carbon/carbon composites

    International Nuclear Information System (INIS)

    Prem, M.; Krexner, G.; Peterlik, H.

    2005-01-01

    Full text: Carbon/Carbon (C/C) composites, built up from bi-directionally woven fabrics from PAN based carbon fibers, pre-impregnated with phenolic resin followed by pressure curing and carbonization at 1000 o C and a final heat treatment at either 1800 o C or 2400 o C, were investigated by means of small-angle as well as wideangle elastic neutron scattering. Sample orientations arranging the carbon fibers parallel and perpendicular to the incoming beam were examined. Structural features of the composites, i.e. of the fibers as well as the inherently existing pores, are presented and the influence of the heat treatment on the structural properties is discussed. (author)

  16. Microstructure and surface properties of lignocellulosic-based activated carbons

    International Nuclear Information System (INIS)

    González-García, P.; Centeno, T.A.; Urones-Garrote, E.; Ávila-Brande, D.; Otero-Díaz, L.C.

    2013-01-01

    Highlights: ► Activated carbons were produced by KOH activation at 700 °C. ► The observed nanostructure consists of highly disordered graphene–like layers with sp 2 bond content ≈ 95%. ► Textural parameters show high surface area (≈ 1000 m 2 /g) and pore width of 1.3–1.8 nm. ► Specific capacitance reaches values as high as 161 F/g. - Abstract: Low cost activated carbons have been produced via chemical activation, by using KOH at 700 °C, from the bamboo species Guadua Angustifolia and Bambusa Vulgaris Striata and the residues from shells of the fruits of Castanea Sativa and Juglans Regia as carbon precursors. The scanning electron microscopy micrographs show the conservation of the precursor shape in the case of the Guadua Angustifolia and Bambusa Vulgaris Striata activated carbons. Transmission electron microscopy analyses reveal that these materials consist of carbon platelet–like particles with variable length and thickness, formed by highly disordered graphene–like layers with sp 2 content ≈ 95% and average mass density of 1.65 g/cm 3 (25% below standard graphite). Textural parameters indicate a high porosity development with surface areas ranging from 850 to 1100 m 2 /g and average pore width centered in the supermicropores range (1.3–1.8 nm). The electrochemical performance of the activated carbons shows specific capacitance values at low current density (1 mA/cm 2 ) as high as 161 F/g in the Juglans Regia activated carbon, as a result of its textural parameters and the presence of pseudocapacitance derived from surface oxygenated acidic groups (mainly quinones and ethers) identified in this activated carbon.

  17. ATLAS BigPanDA Monitoring

    CERN Document Server

    Padolski, Siarhei; The ATLAS collaboration; Klimentov, Alexei; Korchuganova, Tatiana

    2017-01-01

    BigPanDA monitoring is a web based application which provides various processing and representation of the Production and Distributed Analysis (PanDA) system objects states. Analyzing hundreds of millions of computation entities such as an event or a job BigPanDA monitoring builds different scale and levels of abstraction reports in real time mode. Provided information allows users to drill down into the reason of a concrete event failure or observe system bigger picture such as tracking the computation nucleus and satellites performance or the progress of whole production campaign. PanDA system was originally developed for the Atlas experiment and today effectively managing more than 2 million jobs per day distributed over 170 computing centers worldwide. BigPanDA is its core component commissioned in the middle of 2014 and now is the primary source of information for ATLAS users about state of their computations and the source of decision support information for shifters, operators and managers. In this wor...

  18. ATLAS BigPanDA Monitoring

    CERN Document Server

    Padolski, Siarhei; The ATLAS collaboration

    2017-01-01

    BigPanDA monitoring is a web-based application that provides various processing and representation of the Production and Distributed Analysis (PanDA) system objects states. Analysing hundreds of millions of computation entities such as an event or a job BigPanDA monitoring builds different scale and levels of abstraction reports in real time mode. Provided information allows users to drill down into the reason of a concrete event failure or observe system bigger picture such as tracking the computation nucleus and satellites performance or the progress of whole production campaign. PanDA system was originally developed for the Atlas experiment and today effectively managing more than 2 million jobs per day distributed over 170 computing centers worldwide. BigPanDA is its core component commissioned in the middle of 2014 and now is the primary source of information for ATLAS users about state of their computations and the source of decision support information for shifters, operators and managers. In this work...

  19. The carbon fiber development for uranium centrifuges: a Brazilian cooperative research

    International Nuclear Information System (INIS)

    Queiroz, Paulo Cesar Beltrao de; Zouain, Desiree Moraes

    2009-01-01

    This paper analyzes both the carbon fiber-based development for uranium centrifuges and the research project that supports its development effort over time. The carbon fiber-based engineering properties make it a valuable supply for high technologic products. Nevertheless, its fabrication occurs only in few developed countries and there is no production in Brazil. In addition, the carbon fiber-based products have dual applications: they can be used by the civilian and military industry. Therefore, there are international restrictions related to its use and applications that justify the internal development. Moreover, the Brazilian Navy centrifuges for uranium enrichment were developed using carbon-fiber which contains polyacrylonitrile (PAN) as an imported raw material. The PAN properties of low weight, high tensile strength increase the isotopic separation efficiency. The Brazilian financial scenario surrounded by the international uncertain economy shows that combined creative project solutions are more effective. Therefore, the Navy's Technological Center in Sao Paulo (CTMSP), the University of Campinas (UNICAMP), the University of Sao Paulo (USP), the RADICIFIBRAS Company, and the Brazilian FINEP agency, which is responsible for the project financial support, established a partnership aiming the development of a domestic PAN-based carbon fiber industry. The innovative project solutions adopted and the results of this partnership are presented here. (author)

  20. Adsorption of lignite-derived humic acids on coal-based mesoporous activated carbons.

    Science.gov (United States)

    Lorenc-Grabowska, Ewa; Gryglewicz, Grazyna

    2005-04-15

    The adsorption by a coal-based mesoporous activated carbon of humic acids (HAs) isolated from two Polish lignites was studied. For comparison, a commercial Aldrich humic acid was also included into this study. The differences in chemical structure and functional groups of HAs were determined by elemental analysis and infrared spectroscopy DRIFT. Two activated carbons used differed in terms of mesopore volume, mesopore size distribution, and chemical properties of the surface. The kinetics of adsorption of HAs have been discussed using three kinetic models, i.e., the first-order Lagergren model, the pseudo-second-order model, and the intraparticle diffusion model. It was found that the adsorption of HAs from alkaline solution on mesoporous activated carbon proceeds according to the pseudo-second-order model. The correlation coefficients were close to 1. The intraparticle diffusion of HA molecules within the carbon particle was identified to be the rate-limiting step. Comparing the two activated carbons, the carbon with a higher volume of pores with widths of 10-50 nm showed a greater removal efficiency of HA. An increase in the Freundlich adsorption capacity with decreasing carbon content of HA was observed. Among the HAs studied, S-HA shows characteristics indicating the highest contribution of small-size fraction. The S-HA was removed by both activated carbons to the highest extent. The effect of pH solution on the adsorption of HA was examined over the range pH 5.4-12.2. It was found that the extent of adsorption decreased with decreasing pH of the solution.

  1. Stability of the Gel Electrolyte PAN : EC : PC : LICF3SO3 towards Lithium

    DEFF Research Database (Denmark)

    Perera, Kumudu; Dissanayake, M.A.K.L.; Skaarup, Steen

    2006-01-01

    The stability of the gel electrolyte consisting of polyacrylonitrile (PAN), ethylene carbonate (EC), propylene carbonate (PC) and lithium trifluoromethanesulfonate (LiCF3SO3 – LiTF) towards metallic lithium was investigated using the time evolution of impedance plots. Symmetric cells of the form Li...... / PAN : EC : PC: LiTF / Li were assembled and impedance data were collected at room temperature for one week. A clear indication of growth of a resistive layer could be seen. The electrolyte resistance remained constant. The growth of the passivation layer became constant after first two days...

  2. Towards a holistic review of Pan-Africanism: linking the idea and the movement.

    Science.gov (United States)

    Young, Kurt B

    2010-01-01

    This article explores two general approaches to defining Pan-Africanism. Traditional Pan-Africanism reflects definitions of Pan-Africanism that begin with the assumption that distinctions must be made between early "ideas" of group identification with Africa versus modern organizational activities. However, holistic approaches emphasize the interconnectivity of Pan-African ideas and concrete activities. This discussion explores these approaches and their implications for contemporary analyses of Pan-Africanism. The essay concludes that the holistic line is best suited for developing a new model in Pan-Africanism.

  3. Multimolecular tracers of terrestrial carbon transfer across the pan-Arctic: 14C characteristics of sedimentary carbon components and their environmental controls

    Science.gov (United States)

    Feng, Xiaojuan; Gustafsson, Örjan; Holmes, R. Max; Vonk, Jorien E.; van Dongen, Bart E.; Semiletov, Igor P.; Dudarev, Oleg V.; Yunker, Mark B.; Macdonald, Robie W.; Wacker, Lukas; Montluçon, Daniel B.; Eglinton, Timothy I.

    2015-11-01

    Distinguishing the sources, ages, and fate of various terrestrial organic carbon (OC) pools mobilized from heterogeneous Arctic landscapes is key to assessing climatic impacts on the fluvial release of carbon from permafrost. Through molecular 14C measurements, including novel analyses of suberin- and/or cutin-derived diacids (DAs) and hydroxy fatty acids (FAs), we compared the radiocarbon characteristics of a comprehensive suite of terrestrial markers (including plant wax lipids, cutin, suberin, lignin, and hydroxy phenols) in the sedimentary particles from nine major arctic and subarctic rivers in order to establish a benchmark assessment of the mobilization patterns of terrestrial OC pools across the pan-Arctic. Terrestrial lipids, including suberin-derived longer-chain DAs (C24,26,28), plant wax FAs (C24,26,28), and n-alkanes (C27,29,31), incorporated significant inputs of aged carbon, presumably from deeper soil horizons. Mobilization and translocation of these "old" terrestrial carbon components was dependent on nonlinear processes associated with permafrost distributions. By contrast, shorter-chain (C16,18) DAs and lignin phenols (as well as hydroxy phenols in rivers outside eastern Eurasian Arctic) were much more enriched in 14C, suggesting incorporation of relatively young carbon supplied by runoff processes from recent vegetation debris and surface layers. Furthermore, the radiocarbon content of terrestrial markers is heavily influenced by specific OC sources and degradation status. Overall, multitracer molecular 14C analysis sheds new light on the mobilization of terrestrial OC from arctic watersheds. Our findings of distinct ages for various terrestrial carbon components may aid in elucidating fate of different terrestrial OC pools in the face of increasing arctic permafrost thaw.

  4. Managing the impact of gold panning activities within the context of integrated water resources management planning in the Lower Manyame Sub-Catchment, Zambezi Basin, Zimbabwe

    Science.gov (United States)

    Zwane, Nonhlanhla; Love, David; Hoko, Zvikomborero; Shoko, Dennis

    Riverbed alluvial gold panning activities are a cause for degradation of river channels and banks as well as water resources, particularly through accelerated erosion and siltation, in many areas of Zimbabwe. The lower Manyame sub-catchment located in the Northern part of the country is one such area. This study analysed the implications of cross-sectoral coordination of the management of panning and its impacts. This is within the context of conflicts of interests and responsibilities. A situational analysis of different stakeholders from sectors that included mining, environment, water, local government and water users who were located next to identified panning sites, as well as panners was carried out. Selected sites along the Dande River were observed to assess the environmental effects. The study determined that all stakeholder groups perceived siltation and river bank degradation as the most severe effect of panning on water resources, yet there were divergent views with regards to coordination of panning management. The Water Act of 1998 does not give enough power to management institutions including the Lower Manyame Sub-catchment Council to protect water resources from the impacts of panning, despite the fact that the activities affect the water resource base. The Mines and Minerals Act of 1996 remains the most powerful legislation, while mining sector activities adversely affect environmental resources. Furthermore, complexities were caused by differences in the definition of water resources management boundaries as compared to the overall environmental resources management boundaries according to the Environmental Management Act (EMA) of 2000, and by separate yet parallel water and environmental planning processes. Environmental sector institutions according to the EMA are well linked to local government functions and resource management is administrative, enhancing efficient coordination.

  5. Fabrication of an aluminum, Caribbean-style, musical pan: Metallurgical and acoustical characterization

    International Nuclear Information System (INIS)

    Murr, L.E.; Esquivel, E.V.; Lawrie, S.C.; Lopez, M.I.; Lair, S.L.; Soto, K.F.; Gaytan, S.M.; Bujanda, D.; Kerns, R.G.; Guerrero, P.A.; Flores, J.A.

    2006-01-01

    We report herein the first development and fabrication of a 6061 aluminum alloy pan and compare its tuning and acoustic spectra for selected notes with a standard low-carbon steel Caribbean pan fabricated from a 210-L barrel. The experimental aluminum alloy pan was completely manufactured by welding a 1.68-mm-thick head sheet to a 9-mm 2 aluminum alloy hoop, sinking the head by pneumatic hammering and welding a 1.15-mm-thick aluminum alloy side or skirt to the hoop. This experimental pan was 0.66 m in diameter, in contrast to the 210-L steel barrel standard, which had a diameter of 0.57 m. Chromatic tones were observed for most rim notes on the aluminum alloy pan, but the highest octave range notes at the pan bottom were not tuned. Microstructural characterization by light optical metallography and transmission electron microscopy illustrated the necessity for high dislocation densities and associated hardness in order to stabilize the notes and to assure their chromatic tuning

  6. 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)

  7. Activated Biomass-derived Graphene-based Carbons for Supercapacitors with High Energy and Power Density.

    Science.gov (United States)

    Jung, SungHoon; Myung, Yusik; Kim, Bit Na; Kim, In Gyoo; You, In-Kyu; Kim, TaeYoung

    2018-01-30

    Here, we present a facile and low-cost method to produce hierarchically porous graphene-based carbons from a biomass source. Three-dimensional (3D) graphene-based carbons were produced through continuous sequential steps such as the formation and transformation of glucose-based polymers into 3D foam-like structures and their subsequent carbonization to form the corresponding macroporous carbons with thin graphene-based carbon walls of macropores and intersectional carbon skeletons. Physical and chemical activation was then performed on this carbon to create micro- and meso-pores, thereby producing hierarchically porous biomass-derived graphene-based carbons with a high Brunauer-Emmett-Teller specific surface area of 3,657 m 2  g -1 . Owing to its exceptionally high surface area, interconnected hierarchical pore networks, and a high degree of graphitization, this carbon exhibited a high specific capacitance of 175 F g -1 in ionic liquid electrolyte. A supercapacitor constructed with this carbon yielded a maximum energy density of 74 Wh kg -1 and a maximum power density of 408 kW kg -1 , based on the total mass of electrodes, which is comparable to those of the state-of-the-art graphene-based carbons. This approach holds promise for the low-cost and readily scalable production of high performance electrode materials for supercapacitors.

  8. Comparative study of selenite adsorption on carbon based adsorbents and activated alumina.

    Science.gov (United States)

    Jegadeesan, G; Mondal, K; Lalvani, S B

    2003-08-01

    The sorption characteristics of carbon-based adsorbents such as activated carbon and chitin for the removal of selenite, Se (IV), an anionic, hazardous contaminant, are compared with those of alpha and gamma alumina. Batch experiments were conducted to determine the influence of pH, concentration of adsorbate, adsorbent loading and temperature on the sorption characteristics of the adsorbents. Generally, low pH of the solution resulted in favorable selenium removal. With the exception of activated carbon, uptakes decreased with increase in temperature. In comparison, chitin was found to be far less effective for the removal of Se (IV) from aqueous solutions. The data also showed that gamma alumina provided higher selenium removal percentages (99%) compared to alpha alumina (94%), activated carbon (87%) and chitin (49%). The selenite removal was found to decrease with increasing initial Se (IV) concentration in the solution. Adsorption capacities of the adsorbents are reported in terms of their Langmuir adsorption isotherms. The adsorption capacity (on unit mass basis) of the adsorbents for selenite is in the order: chitin (specific area (sa) = 9.58 m2 g(-1)) activated carbon (sa = 96.37 m2 g(-1)) < alpha alumina (sa = 6 m2 g(-1)) < gamma alumina (sa = 150 m2 g(-1)).

  9. Developing a Competency-Based Pan-European Accreditation Framework for Health Promotion

    Science.gov (United States)

    Battel-Kirk, Barbara; Van der Zanden, Gerard; Schipperen, Marielle; Contu, Paolo; Gallardo, Carmen; Martinez, Ana; Garcia de Sola, Silvia; Sotgiu, Alessandra; Zaagsma, Miriam; Barry, Margaret M.

    2012-01-01

    Background: The CompHP Pan-European Accreditation Framework for Health Promotion was developed as part of the CompHP Project that aimed to develop competency-based standards and an accreditation system for health promotion practice, education, and training in Europe. Method: A phased, multiple-method approach was employed to facilitate consensus…

  10. Preparation of mesoporous carbon from fructose using zinc-based activators

    Directory of Open Access Journals (Sweden)

    Tutik Setianingsih

    2015-07-01

    Full Text Available Mesoporous carbons were synthesized from fructose using activators of zinc silicate (ZS, zinc borate (ZB, and zinc borosilicate (ZBS. The synthesis involves 3 steps, including caramelization of sugar, carbonization of caramel, and washing of carbon to separate the activator from the carbon. The solid products were characterized by N2 gas adsorption-desorption, X-ray diffraction, FTIR spectrophotometry, and Transmission Electron Microscopy. The pore characterizations of the carbons indicate that in ZBS system, ZB may have the role as mesopore size controller, whereas silica component may improve porosity created by ZB without changing the size. This role of ZB may be connected to it’s performance as catalyst of caramelization and it’s crystalinity, as supported by measurement of caramel intermediete and characterization of the activators with X-ray diffraction. The infrared spectra confirms that the carbons’s surfaces have C=O, C-O, and O-H functional groups. The XRD patterns of the carbons show that all activators create the turbotratic carbons.

  11. Analysis of the Microstructure and Oxidation Behavior of Some Commercial Carbon Fibers

    International Nuclear Information System (INIS)

    Kim, Dae Ho; Kim, Bohye; Yang, Kap Seung; Im, Hun Kook; Bang, Yun Hyuk; Kim, Sung Ryong

    2011-01-01

    The relationship between the microstructure, mechanical properties, and oxidation behavior of pitch-, polyacrylonitrile (PAN)-, and Rayon-based carbon fibers (CFs) has been studied in detail. Three types of carbon fiber were exposed to isothermal oxidation in air and the weight change was measured by thermogravimetric analyzer (TGA) apparatus. After activation energy was gained according to the conversion at reacting temperature, the value of specific surface area and the surface morphology was compared, and the reaction mechanism of oxidation affecting development of pores of carbon fibers was examined. This study will lead to a new insight into the relationship between the microstructure and mechanical properties of carbon fibers

  12. High-performance all-solid-state flexible supercapacitors based on two-step activated carbon cloth

    Science.gov (United States)

    Jiang, Shulan; Shi, Tielin; Zhan, Xiaobin; Long, Hu; Xi, Shuang; Hu, Hao; Tang, Zirong

    2014-12-01

    A simple and effective strategy is proposed to activate carbon cloth for the fabrication of flexible and high-performance supercapacitors. Firstly, the carbon cloth surface is exfoliated as nanotextures through wet chemical treatment, then an annealing process is applied at H2/N2 atmosphere to reduce the surface oxygen functional groups which are mainly introduced from the first step. The activated carbon cloth electrode shows excellent wettablity, large surface area and delivers remarkable electrochemical performance. A maximum areal capacitance of 485.64 mF cm-2 at the current density of 2 mA cm-2 is achieved for the activated carbon cloth electrode, which is considerably larger than the resported results for carbon cloth. Furthermore, the flexible all-solid-state supercapacitor, which is fabricated based on the activated carbon cloth electrodes, shows high areal capacitance, superior cycling stability as well as stable electrochemical performance even under constant bending or twisting conditions. An areal capacitance of 161.28 mF cm-2 is achieved at the current density of 12.5 mA cm-2, and 104% of its initial capacitance is retained after 30,000 charging/discharging cycles. This study would also provide an effective way to boost devices' electrochemical performance by accommodating other active materials on the activated carbon cloth.

  13. ATLAS Global Shares Implementation in the PanDA Workload Management System

    CERN Document Server

    Barreiro Megino, Fernando Harald; The ATLAS collaboration

    2018-01-01

    PanDA (Production and Distributed Analysis) is the workload management system for ATLAS across the Worldwide LHC Computing Grid. While analysis tasks are submitted to PanDA by over a thousand users following personal schedules (e.g. PhD or conference deadlines), production campaigns are scheduled by a central Physics Coordination group based on the organization’s calendar. The Physics Coordination group needs to allocate the amount of Grid resources dedicated to each activity, in order to manage sharing of CPU resources among various parallel campaigns and to make sure that results can be achieved in time for important deadlines. While dynamic and static shares on batch systems have been around for a long time, we are trying to move away from local resource partitioning and manage shares at a global level in the PanDA system. The global solution is not straightforward, given different requirements of the activities (number of cores, memory, I/O and CPU intensity), the heterogeneity of Grid resources (site/H...

  14. Synthesis of polyacrylonitrile (PAN) with different stereoregularity by urea radiation inclusion polymerization and its application to carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

    Fujikura, Yoshiaki; Minakawa, Masaaki [Yamagata Univ., Yonezawa (Japan). Faculty of Engineering; Makuuchi, Keizo; Matsuo, Masaru; Yoshii, Fumio

    1998-01-01

    Application to carbon fiber started in this Year. In this paper, a spinning and calcination process are explained. Fiber was obtained by wet spinning of the PAN solution. Ten solvents were tested and the results proved that dimethyl sulfoxide (DMSO) was the best solvent. Glycerine was used as a coagulating bath. The thin fiber (10 to 50 denier) was produced under the conditions of about 20wt% concentration at about 110degC. Heat-treat temperature was about 270 to 275degC. The viscosity-tacticity relationship and T{sub sol} vs. inverse tacticity were shown in the paper. (S.Y.)

  15. Effect of surface modification on carbon fiber and its reinforced phenolic matrix composite

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Hua [Key Laboratory for Liquid phase chemical oxidation Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Carbon Fibre Engineering Research Center, Faculty of Materials Science, Shandong University, Jinan 250061 (China); Wang Chengguo, E-mail: sduwangchg@gmail.com [Carbon Fibre Engineering Research Center, Faculty of Materials Science, Shandong University, Jinan 250061 (China); Zhang Shan; Lin Xue [Carbon Fibre Engineering Research Center, Faculty of Materials Science, Shandong University, Jinan 250061 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer We used very simple and effective modification method to treat PAN-based carbon fiber by liquid oxidation and coupling agent. Black-Right-Pointing-Pointer Carbon fiber surface functional groups were analyzed by LRS and XPS. Black-Right-Pointing-Pointer Proper treatment of carbon fiber can prove an effective way to increase composite's performance. Black-Right-Pointing-Pointer Carbon fiber surface modifications by oxidation and APS could strengthen fiber activity and enlarge surface area as well as its roughness. - Abstract: In this work, polyacrylonitrile (PAN)-based carbon fiber were chemically modified with H{sub 2}SO{sub 4}, KClO{sub 3} and silane coupling agent ({gamma}-aminopropyltriethoxysilane, APS), and carbon fiber reinforced phenolic matrix composites were prepared. The structural and surface characteristics of the carbon fiber were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), laser Raman scattering (LRS) and Fourier transform infrared spectroscopy (FTIR). Single fiber mechanical properties, specific surface area, composite impact properties and interfacial shear strength (ILSS) were researched to indicate the effects of surface modification on fibers and the interaction between modified fiber surface and phenolic matrix. The results showed that carbon fiber surface modification by oxidation and APS can strengthen fiber surface chemical activity and enlarge the fiber surface area as well as its roughness. When carbon fiber (CF) is oxidized treatment, the oxygen content as well as the O/C ratio will be obviously increased. Oxygen functional groups increase with oxidation time increasing. Carbon fiber treated with APS will make C-O-R content increase and O-C=O content decrease due to surface reaction. Proper treatment of carbon fiber with acid and silane coupling agent prove an effective way to increase the interfacial adhesion and improve the mechanical and outdoor

  16. Effect of surface modification on carbon fiber and its reinforced phenolic matrix composite

    International Nuclear Information System (INIS)

    Yuan Hua; Wang Chengguo; Zhang Shan; Lin Xue

    2012-01-01

    Highlights: ► We used very simple and effective modification method to treat PAN-based carbon fiber by liquid oxidation and coupling agent. ► Carbon fiber surface functional groups were analyzed by LRS and XPS. ► Proper treatment of carbon fiber can prove an effective way to increase composite's performance. ► Carbon fiber surface modifications by oxidation and APS could strengthen fiber activity and enlarge surface area as well as its roughness. - Abstract: In this work, polyacrylonitrile (PAN)-based carbon fiber were chemically modified with H 2 SO 4 , KClO 3 and silane coupling agent (γ-aminopropyltriethoxysilane, APS), and carbon fiber reinforced phenolic matrix composites were prepared. The structural and surface characteristics of the carbon fiber were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), laser Raman scattering (LRS) and Fourier transform infrared spectroscopy (FTIR). Single fiber mechanical properties, specific surface area, composite impact properties and interfacial shear strength (ILSS) were researched to indicate the effects of surface modification on fibers and the interaction between modified fiber surface and phenolic matrix. The results showed that carbon fiber surface modification by oxidation and APS can strengthen fiber surface chemical activity and enlarge the fiber surface area as well as its roughness. When carbon fiber (CF) is oxidized treatment, the oxygen content as well as the O/C ratio will be obviously increased. Oxygen functional groups increase with oxidation time increasing. Carbon fiber treated with APS will make C-O-R content increase and O-C=O content decrease due to surface reaction. Proper treatment of carbon fiber with acid and silane coupling agent prove an effective way to increase the interfacial adhesion and improve the mechanical and outdoor performance of the resulting fiber/resin composites.

  17. Carbon nanofibers obtained from electrospinning process

    Science.gov (United States)

    Bovi de Oliveira, Juliana; Müller Guerrini, Lília; Sizuka Oishi, Silvia; Rogerio de Oliveira Hein, Luis; dos Santos Conejo, Luíza; Cerqueira Rezende, Mirabel; Cocchieri Botelho, Edson

    2018-02-01

    In recent years, reinforcements consisting of carbon nanostructures, such as carbon nanotubes, fullerenes, graphenes, and carbon nanofibers have received significant attention due mainly to their chemical inertness and good mechanical, electrical and thermal properties. Since carbon nanofibers comprise a continuous reinforcing with high specific surface area, associated with the fact that they can be obtained at a low cost and in a large amount, they have shown to be advantageous compared to traditional carbon nanotubes. The main objective of this work is the processing of carbon nanofibers, using polyacrylonitrile (PAN) as a precursor, obtained by the electrospinning process via polymer solution, with subsequent use for airspace applications as reinforcement in polymer composites. In this work, firstly PAN nanofibers were produced by electrospinning with diameters in the range of (375 ± 85) nm, using a dimethylformamide solution. Using a furnace, the PAN nanofiber was converted into carbon nanofiber. Morphologies and structures of PAN and carbon nanofibers were investigated by scanning electron microscopy, Raman Spectroscopy, thermogravimetric analyses and differential scanning calorimeter. The resulting residual weight after carbonization was approximately 38% in weight, with a diameters reduction of 50%, and the same showed a carbon yield of 25%. From the analysis of the crystalline structure of the carbonized material, it was found that the material presented a disordered structure.

  18. ATLAS BigPanDA Monitoring and Its Evolution

    CERN Document Server

    Wenaus, Torre; The ATLAS collaboration; Korchuganova, Tatiana

    2016-01-01

    BigPanDA is the latest generation of the monitoring system for the Production and Distributed Analysis (PanDA) system. The BigPanDA monitor is a core component of PanDA and also serves the monitoring needs of the new ATLAS Production System Prodsys-2. BigPanDA has been developed to serve the growing computation needs of the ATLAS Experiment and the wider applications of PanDA beyond ATLAS. Through a system-wide job database, the BigPanDA monitor provides a comprehensive and coherent view of the tasks and jobs executed by the system, from high level summaries to detailed drill-down job diagnostics. The system has been in production and has remained in continuous development since mid 2014, today effectively managing more than 2 million jobs per day distributed over 150 computing centers worldwide. BigPanDA also delivers web-based analytics and system state views to groups of users including distributed computing systems operators, shifters, physicist end-users, computing managers and accounting services. Provi...

  19. 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.

  20. Adsorption of iodine from COIL waste gas on soaked coal-based activated carbon

    Science.gov (United States)

    Zhou, Junbo; Hao, Shan; Gao, Liping

    2014-04-01

    The chemical oxygen-iodine laser (COIL) has wide application prospects in military, industrial and medical treatment fields as a second generation gas chemical laser to follow the first HF/DF chemical laser. However, a COIL releases large amounts of gas, such as helium, oxygen, chlorine and iodine. Chlorides have a serious corrosive effect on the system, especially iodine vapor crystallization, which seriously endangers the normal use of vacuum systems, and radioactive methyl iodide, which is hazardous to operators and pollutes the environment. The use of soaked coal-based activated carbon as an adsorbent for removing methyl iodine is proposed, while it is proposed that coal-based activated carbon is an effective adsorbent for removing stable iodine. The research conducted in this work shows that iodine residues are less than 0.5 μg ml-1 after the adsorption treatment and the decontamination factor of the coal-based activated carbon for removing stable iodine is more than 1000. Using this method can achieve the purpose of removing harmful iodine, satisfy the requirements for engineering applications, and also be applied to other nuclear power plant flue gas treatments.

  1. Adaptability and selectivity of human peroxisome proliferator-activated receptor (PPAR) pan agonists revealed from crystal structures

    International Nuclear Information System (INIS)

    Oyama, Takuji; Toyota, Kenji; Waku, Tsuyoshi; Hirakawa, Yuko; Nagasawa, Naoko; Kasuga, Jun-ichi; Hashimoto, Yuichi; Miyachi, Hiroyuki; Morikawa, Kosuke

    2009-01-01

    The structures of the ligand-binding domains (LBDs) of human peroxisome proliferator-activated receptors (PPARα, PPARγ and PPARδ) in complexes with a pan agonist, an α/δ dual agonist and a PPARδ-specific agonist were determined. The results explain how each ligand is recognized by the PPAR LBDs at an atomic level. Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor family, which is defined as transcriptional factors that are activated by the binding of ligands to their ligand-binding domains (LBDs). Although the three PPAR subtypes display different tissue distribution patterns and distinct pharmacological profiles, they all are essentially related to fatty-acid and glucose metabolism. Since the PPARs share similar three-dimensional structures within the LBDs, synthetic ligands which simultaneously activate two or all of the PPARs could be potent candidates in terms of drugs for the treatment of abnormal metabolic homeostasis. The structures of several PPAR LBDs were determined in complex with synthetic ligands, derivatives of 3-(4-alkoxyphenyl)propanoic acid, which exhibit unique agonistic activities. The PPARα and PPARγ LBDs were complexed with the same pan agonist, TIPP-703, which activates all three PPARs and their crystal structures were determined. The two LBD–ligand complex structures revealed how the pan agonist is adapted to the similar, but significantly different, ligand-binding pockets of the PPARs. The structures of the PPARδ LBD in complex with an α/δ-selective ligand, TIPP-401, and with a related δ-specific ligand, TIPP-204, were also determined. The comparison between the two PPARδ complexes revealed how each ligand exhibits either a ‘dual selective’ or ‘single specific’ binding mode

  2. Concentration of uranium on TiO-PAN and NaTiO-PAN composite absorbers

    International Nuclear Information System (INIS)

    Motl, Alois; Sebesta, Ferdinand; John, Jan; Spendlikova, Irena; Nemec, Mojmir

    2013-01-01

    finely divided inorganic absorbers. The general procedure for the preparation of the resulting inorganic-organic composite absorbers enables preparation of suitably grained composite absorbers. The contents of active component may reach up to 90% (W/W) in dry residue. The aim of this study was to verify possibility of extraction of uranium with TiO-PAN and NaTiO-PAN composite absorbers, to compare properties of these two absorbers and to conclude whether they are prospective for uranium collection from surface and/or waste waters. Hydrated titanium oxide (TiO) and sodium titanate (NaTiO) -the active components of the composite materials-were prepared from industrial intermediate from production of titanium white. Standard procedure was used to prepare the TiO-PAN and NaTiO-PAN composite absorbers. In the experiments, distilled and tap water were used to compare the influence of the water hardness. pH of the effluent was also measured during the process. The results showed that practical sorption capacity (10% break-through) from tap water containing 2.3 μg U.mL -1 measured at flow rate of 100 BV.h -1 was ∼ 4.6 mg and ∼1.5 mg of uranium per ml of swollen TiO-PAN and NaTiO-PAN absorber, respectively. The maximum flow rates are 60 BV.h -1 and 60-100 BV.h -1 for TiO-PAN and NaTiO-PAN absorbers, respectively, depending on the concentration of uranium (2.3-230 mg U.L -1 ). Elution of uranium and regeneration of the absorber may be accomplished by 0.1 mol.L -1 or stronger solutions of hydrochloric acid for both the absorbers. Hence, TiO-PAN and NaTiO-PAN composite absorbers were proved to be applicable for extraction of uranium from aqueous solutions. With respect to the measured practical sorption capacity, TiO-PAN composite absorber is more suitable for the uranium collection from surface and/or waste water. (author)

  3. Solid-phase extraction of iridium from soil and water samples by using activated carbon cloth prior to its spectrophotometric determination.

    Science.gov (United States)

    Ozkantar, Nebiye; Yilmaz, Erkan; Soylak, Mustafa; Tuzen, Mustafa

    2015-08-01

    A solid-phase extraction method for separation and preconcentration of Ir(IV) ion by using activated carbon cloth (ACC) has been presented. Ir(IV) as their 1-(2-pyridylazo) 2-naphtol (PAN) chelate was adsorbed on ACC at pH 2.0 and was eluted from ACC with acidic dimethylformamide (DMF). The Ir(IV) concentration was determined at 536 nm as Ir(IV)-PAN complex by using UV-vis spectrophotometer. The analytical parameters including pH, sample and eluent flow rates, amount of PAN, eluent type, concentration, and sample volume were optimized. The effects of foreign ions on the recoveries of iridium were also investigated. The preconcentration factor was calculated as 60. The limit of detection (LOD) and the limit of quantification (LOQ) of the method were found as 0.039 and 0.129 μg L(-1), respectively. The method was applied to soil and water samples for iridium determination.

  4. Surface modification of polyacrylonitrile-based carbon fiber and its interaction with imide

    International Nuclear Information System (INIS)

    Xu Bing; Wang Xiaoshu; Lu Yun

    2006-01-01

    In this work, sized polyacrylonitrile (PAN)-based carbon fibers were chemically modified with nitric acid and maleic anhydride (MA) in order to improve the interaction between carbon fiber surface and polyimide matrix. Bismaleimide (BMI) was selected as a model compound of polyimide to react with modified carbon fiber. The surface characteristic changing after modification and surface reaction was investigated by element analysis (EA), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and surface enhanced Raman scattering (SERS). The results indicated that the modification of carbon fiber surface with MA might follow the Diels Alder reaction mechanism. In the surface reaction between modified fibers and BMI, among the various surface functional groups, the hydroxyl group provided from phenolic hydroxyl group and bridged structure on carbon fiber may be the most effective group reacted with imide structure. The results may shed some light on the design of the appropriate surface structure, which could react with polyimide, and the manufacture of the carbon fiber-reinforced polyimide matrix composites

  5. Thermal and radiochemical degradation of some PAN copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Jipa, S. [INCDIE, ICPE CA, 313 Splaiul Unirii, P.O. Box 149, Bucharest 030138 (Romania); ' Valachia' University of Targoviste, 18-22 Unirii Av., Targoviste 130082 (Romania); Zaharescu, T. [' Valachia' University of Targoviste, 18-22 Unirii Av., Targoviste 130082 (Romania)], E-mail: traian_zaharescu@yahoo.com; Setnescu, R. [INCDIE, ICPE CA, 313 Splaiul Unirii, P.O. Box 149, Bucharest 030138 (Romania); ' Valachia' University of Targoviste, 18-22 Unirii Av., Targoviste 130082 (Romania); Dragan, E.S.; Dinu, M.V. [' Petru Poni' Institute of Macromolecular Chemistry, Iasi 700487 (Romania)

    2008-12-01

    Polyacrylonitrile (PAN) and some copolymers of acrylonitrile with divinylbenzene (AN-DVB) were investigated by the characterization of their thermal and radiation stabilities. The contribution of DVB to the thermal stability of PAN by the modification in the amount of unsaturated hydrocarbon between 6 and 20% was revealed by the evaluation of oxidation induction periods and required activation energies. The exposure of these materials to the action of {gamma}-radiation points out the higher stability of copolymers (AN-DVB) in comparison to the relative stability of PAN.

  6. Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF6 electrolyte

    International Nuclear Information System (INIS)

    Azam, M.A.; Jantan, N.H.; Dorah, N.; Seman, R.N.A.R.; Manaf, N.S.A.; Kudin, T.I.T.; Yahya, M.Z.A.

    2015-01-01

    Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF 6 non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g −1 . - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, among others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g −1 at a scan rate of 1 mV s −1

  7. Selection of pecan shell-based activated carbons for removal of organic and inorganic impurities from water.

    Science.gov (United States)

    Niandou, Mohamed A S; Novak, Jeffrey M; Bansode, Rishipal R; Yu, Jianmei; Rehrah, Djaafar; Ahmedna, Mohamed

    2013-01-01

    Activated carbons are a byproduct from pyrolysis and have value as a purifying agent. The effectiveness of activated carbons is dependent on feedstock selection and pyrolysis conditions that modify their surface properties. Therefore, pecan shell-based activated carbons (PSACs) were prepared by soaking shells in 50% (v/v) HPO or 25 to 50% of KOH-NaHCO followed by pyrolysis at 400 to 700°C under a N atmosphere. Physically activated PSACs were produced by pyrolysis at 700°C under N followed by activation with steam or CO at 700 to 900°C. Physicochemical, surface, and adsorption properties of the PSACs were compared with two commercially available activated carbons. The average mass yield of PSACs with respect to the initial mass of the biomass was about 20 and 34% for physically activated and chemically activated carbons, respectively. Acid-activated carbons exhibited higher surface area, higher bulk density, and lower ash content compared with steam- or CO-activated carbons and the two commercial products. Base activation led to the development of biochar with moderate to high surface area with surface charges suitable for adsorption of anionic species. Regardless of the activation method, PSACs had high total surface area ranging from 400 to 1000 m g, better pore size distribution, and more surface charges than commercial samples. Our results also showed that PSACs were effective in removing inorganic contaminants such as Cu and NO as well as organic contaminants such as atrazine and metolachlor. This study showed that pyrolysis conditions and activation had a large influence on the PSAC's surface characteristics, which can limit its effectiveness as a custom sorbent for targeted water contaminants. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. PanJen

    DEFF Research Database (Denmark)

    Jensen, Cathrine Ulla; Panduro, Toke Emil

    functional transformations, driven by an a priori and theory-based hypothesis. The plots and model fit metrics enable users to make an informed choice of how to specify the functional form the regression. We show that the PanJen ranking outperforms the Box-Tidwell transformation, especially in the presence...... of inefficiency, heteroscedasticity or endogeneity....

  9. Strategies for enhancing electrochemical activity of carbon-based electrodes for all-vanadium redox flow batteries

    International Nuclear Information System (INIS)

    Flox, Cristina; Skoumal, Marcel; Rubio-Garcia, Javier; Andreu, Teresa; Morante, Juan Ramón

    2013-01-01

    Highlights: ► Improved reactions at the positive electrode in all-vanadium redox flow batteries. ► Graphene-derived and PAN-modified electrodes have been successfully prepared. ► Modification with bimetallic CuPt 3 nanocubes yielded the best catalytic behavior. ► N and O-containing groups enhances the vanadium flow battery performance. - Abstract: Two strategies for improving the electroactivity towards VO 2+ /VO 2 + redox pair, the limiting process in all-vanadium redox flow batteries (VFBs), were presented. CuPt 3 nanoparticles supported onto graphene substrate and nitrogen and oxygen polyacrylonitrile (PAN)-functionalized electrodes materials have been evaluated. The morphology, composition, electrochemical properties of all electrodes prepared was characterized with field emission-scanning electrode microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy and cell charge–discharge test. The presence of the CuPt 3 nanocubes and nitrogen and oxygen functionalities enhance the electrocatalytic activity of the electrodes materials accelerating the oxygen and electron transfer processes. The battery performance was also evaluated using PAN-functionalized electrodes exhibiting a high of energy efficiency of 84% (at current density 20 mA cm −2 ) up to 30th cycle, indicating a promising alternative for improving the VFB

  10. Balanced pan-PPAR activator bezafibrate in combination with statin: comprehensive lipids control and diabetes prevention?

    Directory of Open Access Journals (Sweden)

    Tenenbaum Alexander

    2012-11-01

    Full Text Available Abstract All fibrates are peroxisome proliferators-activated receptors (PPARs-alpha agonists with ability to decrease triglyceride and increase high density lipoprotein- cholesterol (HDL-C. However, bezafibrate has a unique characteristic profile of action since it activates all three PPAR subtypes (alpha, gamma and delta at comparable doses. Therefore, bezafibrate operates as a pan-agonist for all three PPAR isoforms. Selective PPAR gamma agonists (thiazolidinediones are used to treat type 2 diabetes mellitus (T2DM. They improve insulin sensitivity by up-regulating adipogenesis, decreasing free fatty acid levels, and reversing insulin resistance. However, selective PPAR gamma agonists also cause water retention, weight gain, peripheral edema, and congestive heart failure. The expression of PPAR beta/ delta in essentially all cell types and tissues (ubiquitous presence suggests its potential fundamental role in cellular biology. PPAR beta/ delta effects correlated with enhancement of fatty acid oxidation, energy consumption and adaptive thermogenesis. Together, these data implicate PPAR beta/delta in fuel combustion and suggest that pan-PPAR agonists that include a component of PPAR beta/delta activation might offset some of the weight gain issues seen with selective PPAR gamma agonists, as was demonstrated by bezafibrate studies. Suggestively, on the whole body level all PPARs acting as one orchestra and balanced pan-PPAR activation seems as an especially attractive pharmacological goal. Conceptually, combined PPAR gamma and alpha action can target simultaneously insulin resistance and atherogenic dyslipidemia, whereas PPAR beta/delta properties may prevent the development of overweight. Bezafibrate, as all fibrates, significantly reduced plasma triglycerides and increased HDL-C level (but considerably stronger than other major fibrates. Bezafibrate significantly decreased prevalence of small, dense low density lipoproteins particles, remnants

  11. Balanced pan-PPAR activator bezafibrate in combination with statin: comprehensive lipids control and diabetes prevention?

    Science.gov (United States)

    Tenenbaum, Alexander; Fisman, Enrique Z

    2012-11-14

    All fibrates are peroxisome proliferators-activated receptors (PPARs)-alpha agonists with ability to decrease triglyceride and increase high density lipoprotein- cholesterol (HDL-C). However, bezafibrate has a unique characteristic profile of action since it activates all three PPAR subtypes (alpha, gamma and delta) at comparable doses. Therefore, bezafibrate operates as a pan-agonist for all three PPAR isoforms. Selective PPAR gamma agonists (thiazolidinediones) are used to treat type 2 diabetes mellitus (T2DM). They improve insulin sensitivity by up-regulating adipogenesis, decreasing free fatty acid levels, and reversing insulin resistance. However, selective PPAR gamma agonists also cause water retention, weight gain, peripheral edema, and congestive heart failure. The expression of PPAR beta/ delta in essentially all cell types and tissues (ubiquitous presence) suggests its potential fundamental role in cellular biology. PPAR beta/ delta effects correlated with enhancement of fatty acid oxidation, energy consumption and adaptive thermogenesis. Together, these data implicate PPAR beta/delta in fuel combustion and suggest that pan-PPAR agonists that include a component of PPAR beta/delta activation might offset some of the weight gain issues seen with selective PPAR gamma agonists, as was demonstrated by bezafibrate studies. Suggestively, on the whole body level all PPARs acting as one orchestra and balanced pan-PPAR activation seems as an especially attractive pharmacological goal. Conceptually, combined PPAR gamma and alpha action can target simultaneously insulin resistance and atherogenic dyslipidemia, whereas PPAR beta/delta properties may prevent the development of overweight. Bezafibrate, as all fibrates, significantly reduced plasma triglycerides and increased HDL-C level (but considerably stronger than other major fibrates). Bezafibrate significantly decreased prevalence of small, dense low density lipoproteins particles, remnants, induced

  12. Effectiveness of KNIFC-PAN Resin in Absorbing Radiocesium in Seawater

    International Nuclear Information System (INIS)

    Nurrul Assyikeen Mohd Jaffary; Abdul Kadir Ishak; Zal Uyun Wan Mahmood; Wo, Y.M.; Norfaizal Mohamed; Mohd Tarmizi Ishak

    2016-01-01

    The effectiveness of KNiFC-PAN absorber, potassium-nickel hexacyanoferrate (II) (KNiFC) bound into modified polyacrylonitrile (PAN) have been tested for capability in absorbing radiocesium in seawater samples. The efficiency of the KNiFC-PAN were measured by the different activity of the radiocesium measured using Hyper Pure Germanium Detector (HPGe) in initial spiked seawater and eluent seawater after passed through 5 ml of KNiFC absorber. Study showed 87 % effectiveness of the KNiFC-PAN in absorbing radiocesium. Further study conducted to illustrate relation between spiked seawater and activity measured for 5 ml of KniFC passed through spiked seawater in packed column. This study suggested this relative 15L cubitainer method can be used to monitor the radiocesium in emergency situation for the fast and reliable result. (author)

  13. Application of polyacrylonitrile-based polymer electrolytes in rechargeable lithium batteries

    DEFF Research Database (Denmark)

    Perera, K.S.; Dissanayake, M.A.K.L.; Skaarup, Steen

    2008-01-01

    Polyacrylonitrile (PAN)-based polymer electrolytes have obtained considerable attention due to their fascinating characteristics such as appreciable ionic conductivity at ambient temperatures and mechanical stability. This study is based on the system PAN-ethylene carbonate (EC)-propylene carbona...

  14. Kinetic studies on carbon dioxide capture using lignocellulosic based activated carbon

    International Nuclear Information System (INIS)

    Rashidi, Nor Adilla; Yusup, Suzana; Hameed, Bassim H.

    2013-01-01

    CO 2 (Carbon dioxide) emissions are one of the greenhouse gases that cause global warming. The power generation industry is one of the main emitters of CO 2 , and the emissions are expected to increase in the coming years as there seems to be no abatement in the consumption of fossil fuels for the production of electricity. Thus, there is a need for CO 2 adsorption technologies to mitigate the emissions. However, there are several disadvantages associated with the current adsorption technologies. One of the issues is corrosion and the need for specialized equipment. Therefore, alternative and more sustainable materials are sought after to improve the viability of the adsorption technology. In this study, several types of agricultural wastes were used as activated carbon precursors for CO 2 adsorption process in a TGA (thermogravimetric analyser). The adsorption was also modelled through a pseudo-first order and second order model, Elovich's kinetic model, and an intra-particle diffusion model. From the correlation coefficient, it was found that pseudo-second order model was well-fitted with the kinetic data. In addition, activation energy below than 42 kJ/mol confirmed that the physisorption process occurred. - Highlights: • Utilization of lignocellulosic wastes for production of activated carbon. • Single CO 2 activation that yields good adsorptive capacity of adsorbent. • Activation temperature has the most prominent effect on adsorptive properties. • CO 2 adsorption capacity reduces with increasing of adsorption temperature. • Pseudo-second order kinetic model shows best fits to the experimental data

  15. A PanDA backend for the ganga analysis interface

    International Nuclear Information System (INIS)

    Vanderster, D C; Elmsheuser, J; Walker, R; Liko, D; Maeno, T; Wenaus, T; Nilsson, P

    2010-01-01

    Ganga provides a uniform interface for running ATLAS user analyses on a number of local, batch, and grid backends. PanDA is a pilot-based production and distributed analysis system developed and used extensively by ATLAS. This work presents the implementation and usage experiences of a PanDA backend for Ganga. Built upon reusable application libraries from GangaAtlas and PanDA, the Ganga PanDA backend allows users to run their analyses on the worldwide PanDA resources, while providing the ability for users to develop simple or complex analysis workflows in Ganga. Further, the backend allows users to submit and manage 'personal' PanDA pilots: these pilots run under the user's grid certificate and provide a secure alternative to shared pilot certificates while enabling the usage of local resource allocations.

  16. Beyond Slurry-Cast Supercapacitor Electrodes: PAN/MWNT Heteromat-Mediated Ultrahigh Capacitance Electrode Sheets

    Science.gov (United States)

    Lee, Jung Han; Kim, Jeong A.; Kim, Ju-Myung; Lee, Sun-Young; Yeon, Sun-Hwa; Lee, Sang-Young

    2017-01-01

    Supercapacitors (SCs) have garnered considerable attention as an appealing power source for forthcoming smart energy era. An ultimate challenge facing the SCs is the acquisition of higher energy density without impairing their other electrochemical properties. Herein, we demonstrate a new class of polyacrylonitrile (PAN)/multi-walled carbon tube (MWNT) heteromat-mediated ultrahigh capacitance electrode sheets as an unusual electrode architecture strategy to address the aforementioned issue. Vanadium pentoxide (V2O5) is chosen as a model electrode material to explore the feasibility of the suggested concept. The heteromat V2O5 electrode sheets are produced through one-pot fabrication based on concurrent electrospraying (for V2O5 precursor/MWNT) and electrospinning (for PAN nanofiber) followed by calcination, leading to compact packing of V2O5 materials in intimate contact with MWNTs and PAN nanofibers. As a consequence, the heteromat V2O5 electrode sheets offer three-dimensionally bicontinuous electron (arising from MWNT networks)/ion (from spatially reticulated interstitial voids to be filled with liquid electrolytes) conduction pathways, thereby facilitating redox reaction kinetics of V2O5 materials. In addition, elimination of heavy metallic foil current collectors, in combination with the dense packing of V2O5 materials, significantly increases (electrode sheet-based) specific capacitances far beyond those accessible with conventional slurry-cast electrodes.

  17. Phase 2 report on the evaluation of polyacrylonitrile (PAN) as a binding polymer for absorbers used to treat liquid radioactive wastes

    International Nuclear Information System (INIS)

    Sebesta, F.; John, J.; Motl, A.

    1996-05-01

    The performance of PAN-based composite absorbers was evaluated in dynamic experiments at flow rates ranging from 25--100 bed volumes (BV) per hour. Composite absorbers with active components of ammonium molybdophosphate (AMP) PAN and K-Co ferrocyanide (KCoFC) PAN were used for separating Cs from a 1 M HNO 3 + 1 M NaNO 3 + 2 x 10 -5 M CsCl acidic simulant solution. KCoFC-PAN and two other FC-based composite absorbers were tested for separating Cs from alkaline simulant solutions containing 0.01 M to 1 M NaOH and 1 M NaNO 3 + x x 10 -4 M CsCl. The efficiency of the Cs sorption on the AMP-PAN absorber from acidic simulant solutions was negatively influenced by the dissolution of the AMP active component. At flow rates of 50 BV/hr, the decontamination factor of about 10 3 could be maintained for treatment of 380 BV of the feed. With the KCoFC-PAN absorber, the decontamination factor of about 10 3 could be maintained for a feed volume as great as 1,800 BV. In alkaline simulant solutions, significant decomposition of the active components was observed, and the best performance was exhibited by the KCoFC-PAN absorber. Introductory experiments confirmed that Cs may be washed out of the composite absorbers. Regeneration of both absorbers for repetitive use was also found to be possible. The main result of the study is that PAN was proven to be a versatile polymer capable of forming porous composite absorbers with a large number of primary absorbers. The composite absorbers proved to be capable of withstanding the harsh acidic and alkaline conditions and significant radiation doses that may be expected in the treatment of US DOE wastes. A field demonstration is proposed as a follow-on activity

  18. JUSCELINO KUBITSCHEK AND THE PAN-AMERICAN OPERATION (1956-1961

    Directory of Open Access Journals (Sweden)

    Silvana Aline Soares Simon

    2012-09-01

    Full Text Available This article aims to analyse Juscelino Kubitschek’s period, which had the national development as an important characteristic, based on the association with foreign capital. In terms of foreign policy, the period between 1954 and 1958 was characterized by the return to autonomy and active bargaining against the United States. This situation changed at the end of this period, when there were difficulties in attracting foreign investment and there was a slowdown in growth, with the launch of Pan-American Operation. It was a multilateral initiative and showed a new phase of the Brazilian diplomacy, which would culminate in the Independent Foreign Policy. Keywords: Brazilian Foreign Policy, Juscelino Kubitschek, National Development, Pan American Operation, Relationship with the United States.

  19. 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

  20. Design, synthesis and identification of silicon-containing HCV NS5A inhibitors with pan-genotype activity.

    Science.gov (United States)

    Liu, Baomin; Gai, Kuo; Qin, Hui; Liu, Xushi; Cao, Yuan; Lu, Qin; Lu, Dandan; Chen, Deyang; Shen, Hengqiao; Song, Wei; Zhang, Yang; Wang, Xiaojin; Xu, Hongjiang; Zhang, Yinsheng

    2018-03-25

    Modification of a HCV NS5A inhibitor, ombitasvir, led to the identification of 10d with improved pan-genotype NS5A inhibition and better pharmacokinetic properties. The key structural changes to ombitasvir include bioisosteric replacement of carbon with silicon atom. Compared with ombitasvir, the activity of anti-HCV genotypes (GT 1 to 6) of 10d is increased to some extent, especially the inhibitory activity against genotype 3a and 6a is increased by more than seven times, and the dog's in vivo pharmacokinetics properties were also superior to ombitasvir. Further drug evaluation showed that 10d was similar to ombitasvir on plasma protein binding and liver distribution profiles, with no cytotoxicity and no inhibitory effect on both CYP 450 and hERG ligand binding. However, permeability assay results indicated that 10d was not the substrate of P-gp or BCRP transporter, which is different from that of ombitasvir. The results of a 14-day repeat-dose toxicity study identified no toxicity with 10d. Our findings in preclinical tests suggest that the silicon-containing compound 10d could be worthy of continued study as a potential drug candidate. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  1. Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF{sub 6} electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Azam, M.A., E-mail: asyadi@utem.edu.my [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Jantan, N.H.; Dorah, N.; Seman, R.N.A.R.; Manaf, N.S.A. [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Kudin, T.I.T. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); Yahya, M.Z.A. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); National Defence University of Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia)

    2015-09-15

    Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF{sub 6} non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g{sup −1}. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, among others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g{sup −1} at a scan rate of 1 mV s{sup −1}.

  2. Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors

    Science.gov (United States)

    Barzegar, Farshad; Dangbegnon, Julien K.; Bello, Abdulhakeem; Momodu, Damilola Y.; Johnson, A. T. Charlie; Manyala, Ncholu

    2015-09-01

    This article is focused on polymer based gel electrolyte due to the fact that polymers are cheap and can be used to achieve extended potential window for improved energy density of the supercapacitor devices when compared to aqueous electrolytes. Electrochemical characterization of a symmetric supercapacitor devices based on activated carbon in different polyvinyl alcohol (PVA) based gel electrolytes was carried out. The device exhibited a maximum energy density of 24 Wh kg-1 when carbon black was added to the gel electrolyte as conductive additive. The good energy density was correlated with the improved conductivity of the electrolyte medium which is favorable for fast ion transport in this relatively viscous environment. Most importantly, the device remained stable with no capacitance lost after 10,000 cycles.

  3. Poly(3,4-ethylenedioxythiophene-co-(5-amino-2-naphthalenesulfonic acid)) (PEDOT-PANS) film modified glassy carbon electrode for selective detection of dopamine in the presence of ascorbic acid and uric acid

    International Nuclear Information System (INIS)

    Balamurugan, A.; Chen Shenming

    2007-01-01

    Poly(3,4-ethylenedioxythiophene-co-(5-amino-2-naphthalenesulfonic acid)) (PEDOT-PANS) film modified glassy carbon electrode was prepared by electrochemical polymerization technique. The properties of modified electrode was studied. It was found that the electrochemical properties of modified electrode was very much dependent on the experimental conditions, such as monomer oxidation potential and pH. The modified electrode surface was characterized by scanning electron microscopy (SEM). The PEDOT-PANS film modified electrode shows electrocatalytic activity toward oxidation of dopamine (DA) in acetate buffer solution (pH 5.0) and results in a marked enhancement of the current response. The linear sweep voltammetric (LSV) peak heights are linear with DA concentration from 2 x 10 -6 to 1 x 10 -5 M. The detection limit is 5 x 10 -7 M. More over, the interferences of ascorbic acid (AA) and uric acid (UA) were effectively diminished. This work provides a simple and easy approach for selective determination of dopamine in the presence of ascorbic acid and uric acid

  4. Pan-sharpening via compressed superresolution reconstruction and multidictionary learning

    Science.gov (United States)

    Shi, Cheng; Liu, Fang; Li, Lingling; Jiao, Licheng; Hao, Hongxia; Shang, Ronghua; Li, Yangyang

    2018-01-01

    In recent compressed sensing (CS)-based pan-sharpening algorithms, pan-sharpening performance is affected by two key problems. One is that there are always errors between the high-resolution panchromatic (HRP) image and the linear weighted high-resolution multispectral (HRM) image, resulting in spatial and spectral information lost. The other is that the dictionary construction process depends on the nontruth training samples. These problems have limited applications to CS-based pan-sharpening algorithm. To solve these two problems, we propose a pan-sharpening algorithm via compressed superresolution reconstruction and multidictionary learning. Through a two-stage implementation, compressed superresolution reconstruction model reduces the error effectively between the HRP and the linear weighted HRM images. Meanwhile, the multidictionary with ridgelet and curvelet is learned for both the two stages in the superresolution reconstruction process. Since ridgelet and curvelet can better capture the structure and directional characteristics, a better reconstruction result can be obtained. Experiments are done on the QuickBird and IKONOS satellites images. The results indicate that the proposed algorithm is competitive compared with the recent CS-based pan-sharpening methods and other well-known methods.

  5. 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.

  6. Removal of lead (II) from metal plating effluents using sludge based activated carbon as adsorbent.

    Science.gov (United States)

    Raju, P; Saseetharan, M K

    2010-01-01

    A novel adsorbent was prepared from waste sludge obtained from a sugar mill for removing heavy metals from industrial wastewater. The adsorption studies were carried out in batch and continuous modes for both sugar mill sludge based carbon and commercial carbon. In batch studies, experiments were conducted at ambient temperature to assess the influence of the parameters such as pH, adsorbent dose, contact time and equilibrium concentration. Adsorption data for the prepared carbon was found to satisfy both the Freundlich and Langmuir isotherms. Column studies were carried out to delineate the effect of varying depth of carbon at constant flow rate. The breakthrough curves were drawn to establish the mechanism. The result shows that the sludge based activated carbon can be used as an alternative for commercial carbon.

  7. Supercapacitor Electrode Based on Activated Carbon Wool Felt

    Directory of Open Access Journals (Sweden)

    Ana Claudia Pina

    2018-04-01

    Full Text Available An electrical double-layer capacitor (EDLC is based on the physical adsorption/desorption of electrolyte ions onto the surface of electrodes. Due to its high surface area and other properties, such as electrochemical stability and high electrical conductivity, carbon materials are the most widely used materials for EDLC electrodes. In this work, we study an activated carbon felt obtained from sheep wool felt (ACF’f as a supercapacitor electrode. The ACF’f was characterized by elemental analysis, scanning electron microscopy (SEM, textural analysis, and X-ray photoelectron spectroscopy (XPS. The electrochemical behaviour of the ACF’f was tested in a two-electrode Swagelok®-type, using acidic and basic aqueous electrolytes. At low current densities, the maximum specific capacitance determined from the charge-discharge curves were 163 F·g−1 and 152 F·g−1, in acidic and basic electrolytes, respectively. The capacitance retention at higher current densities was better in acidic electrolyte while, for both electrolytes, the voltammogram of the sample presents a typical capacitive behaviour, being in accordance with the electrochemical results.

  8. Carbon felt and carbon fiber - A techno-economic assessment of felt electrodes for redox flow battery applications

    Science.gov (United States)

    Minke, Christine; Kunz, Ulrich; Turek, Thomas

    2017-02-01

    Carbon felt electrodes belong to the key components of redox flow batteries. The purpose of this techno-economic assessment is to uncover the production costs of PAN- and rayon-based carbon felt electrodes. Raw material costs, energy demand and the impact of processability of fiber and felt are considered. This innovative, interdisciplinary approach combines deep insights into technical, ecologic and economic aspects of carbon felt and carbon fiber production. Main results of the calculation model are mass balances, cumulative energy demands (CED) and the production costs of conventional and biogenic carbon felts supplemented by market assessments considering textile and carbon fibers.

  9. Silica decorated on porous activated carbon nanofiber composites for high-performance supercapacitors

    Science.gov (United States)

    Kim, So Yeun; Kim, Bo-Hye

    2016-10-01

    A hybrid of silica decorated on porous activated carbon nanofibers (ACNFs) is fabricated in the form of a web via electrospinning and an activation process as an electrode material for electrochemical capacitors in an organic electrolyte. The introduction of PhSiH3 (PS) into the polyacrylonitrile (PAN) solution induces a porous ACNF structure containing silica nanoparticles (NPs) via the spontaneous sol-gel process of PS by steam in the subsequent physical activation process. These inorganic-organic hybrid composites of porous ACNF containing silica NPs show superior specific capacitance and energy density in electrochemical tests, along with good rate capability and excellent cycle life in an organic electrolyte, which is attributed to the combination of ACNF's high surface area and silica's hydrophilicity. The electrochemical performance decreases with increasing PS concentration, and this trend is consistent with the specific surface area results, which reveal the rapid formation of a double layer.

  10. Moisture condensation behavior of hierarchically carbon nanotube-grafted carbon nanofibers.

    Science.gov (United States)

    Park, Kyu-Min; Lee, Byoung-Sun; Youk, Ji Ho; Lee, Jinyong; Yu, Woong-Reol

    2013-11-13

    Hierarchical micro/nanosurfaces with nanoscale roughness on microscale uneven substrates have been the subject of much recent research interest because of phenomena such as superhydrophobicity. However, an understanding of the effect of the difference in the scale of the hierarchical entities, i.e., nanoscale roughness on microscale uneven substrates as opposed to nanoscale roughness on (a larger) nanoscale uneven surface, is still lacking. In this study, we investigated the effect of the difference in scale between the nano- and microscale features. We fabricated carbon nanotube-grafted carbon nanofibers (CNFs) by dispersing a catalyst precursor in poly (acrylonitrile) (PAN) solution, electrospinning the PAN/catalyst precursor solution, carbonization of electrospun PAN nanofibers, and direct growth of carbon nanotubes (CNTs) on the CNFs. We investigated the relationships between the catalyst concentrations, the size of catalyst nanoparticles on CNFs, and the sizes of CNFs and CNTs. Interestingly, the hydrophobic behavior of micro/nano and nano/nano hierarchical surfaces with water droplets was similar; however a significant difference in the water condensation behavior was observed. Water condensed into smaller droplets on the nano/nano hierarchical surface, causing it to dry much faster.

  11. Evaluation of polyacrylonitrile (PAN) as a binding polymer for absorbers used to treat liquid radioactive wastes

    International Nuclear Information System (INIS)

    Sebesta, F.; John, J.; Motl, A.; Stamberg, K.

    1995-11-01

    The chemical and radiation stability of polyacrylonitrile (PAN) in the form of beads (B-PAN), similar to the beads of composite absorbers, and one selected composite absorber (ammonium molybdophosphate, the active component in PAN binder [AMP-PAN], a prospective candidate for the treatment of acidic wastes) were studied. Aqueous 1M HNO 3 + 1M NaNO 3 , 1M NaOH + 1M NaNO 3 , and 1M NaOH were chosen as simulants of DOE acidic and alkaline wastes. In addition,radiation stability was determined indistilled water. The chemical stability of B-PAN and AMP-PAN beads was tested for a period up to one month of contact with the solution at ambient temperature. The radiation stability of the beads was checked in a radiation dose range 10 3 --10 6 Gy (10 5 --10 8 rads). In acidic solutions the stability of PAN binder was proved not to be limited by either chemical or radiation decomposition. PAN binder may thus be used for preparing composite absorbers for treatment of acid wastes from DOE facilities. The same conclusion is valid for alkaline solutions with pH up to 13. In highly alkaline solutions (concentration of NAOH higher than I M) and in the presence of NaNO 3 , the stability of the tested polyacrylonitrile polymer was sufficient for applications not extending over 10 days. Cross-linking of the polymer caused by ionizing radiation was found to have a positive influence on chemical stability. This effect enables a longer period of applicability of PAN-based composite absorbers. Because of the high sorption rate achievable with PAN-based absorbers, the stability achieved is sufficient for most applications in the DOE complex. The chemical stability of binding polymer may also be further improved by testing another, more suitable type of polymer from the broad family of polyacrylonitrile polymers

  12. Performance of electrodes synthesized with polyacrylonitrile-based carbon nanofibers for application in electrochemical sensors and biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Adabi, Mahdi [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Saber, Reza [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Faridi-Majidi, Reza, E-mail: refaridi@sina.tums.ac.ir [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Faridbod, Farnoush [Science and Technology in Medicine (RCSTIM), Tehran University of Medical Sciences, Tehran, Iran. (Iran, Islamic Republic of)

    2015-03-01

    The purpose of this work was to investigate the performance of electrodes synthesized with Polyacrylonitrile-based carbon nanofibers (PAN-based CNFs). The homogenous PAN solutions with different concentrations were prepared and electrospun to acquire PAN nanofibers and then CNFs were fabricated by heat treatment. The effective parameters for the production of electrospun CNF electrode were investigated. Scanning electron microscopy (SEM) was used to characterize electrospun nanofibers. Cyclic voltammetry was applied to investigate the changes of behavior of electrospun CNF electrodes with different diameters. The structure of CNFs was also evaluated via X-ray diffraction (XRD) and Raman spectroscopy. The results exhibited that diameter of nanofibers reduced with decreasing polymer concentration and applied voltage and increasing tip-to-collector distance, while feeding rate did not have significant effect on nanofiber diameter. The investigations of electrochemical behavior also demonstrated that cyclic voltammetric response improved as diameter of CNFs electrode decreased. - Highlights: • Electrospun CNFs can be directly used as working electrode. • Cyclic voltammetric response improved as diameter of CNFs electrode decreased. • The diameter of nanofibers reduced with decreasing polymer concentration. • The diameter of nanofibers reduced with decreasing applied voltage. • The diameter of nanofibers reduced with increasing tip-to-collector distance.

  13. Performance of electrodes synthesized with polyacrylonitrile-based carbon nanofibers for application in electrochemical sensors and biosensors

    International Nuclear Information System (INIS)

    Adabi, Mahdi; Saber, Reza; Faridi-Majidi, Reza; Faridbod, Farnoush

    2015-01-01

    The purpose of this work was to investigate the performance of electrodes synthesized with Polyacrylonitrile-based carbon nanofibers (PAN-based CNFs). The homogenous PAN solutions with different concentrations were prepared and electrospun to acquire PAN nanofibers and then CNFs were fabricated by heat treatment. The effective parameters for the production of electrospun CNF electrode were investigated. Scanning electron microscopy (SEM) was used to characterize electrospun nanofibers. Cyclic voltammetry was applied to investigate the changes of behavior of electrospun CNF electrodes with different diameters. The structure of CNFs was also evaluated via X-ray diffraction (XRD) and Raman spectroscopy. The results exhibited that diameter of nanofibers reduced with decreasing polymer concentration and applied voltage and increasing tip-to-collector distance, while feeding rate did not have significant effect on nanofiber diameter. The investigations of electrochemical behavior also demonstrated that cyclic voltammetric response improved as diameter of CNFs electrode decreased. - Highlights: • Electrospun CNFs can be directly used as working electrode. • Cyclic voltammetric response improved as diameter of CNFs electrode decreased. • The diameter of nanofibers reduced with decreasing polymer concentration. • The diameter of nanofibers reduced with decreasing applied voltage. • The diameter of nanofibers reduced with increasing tip-to-collector distance

  14. Fabrication of novel micro-nano carbonous composites based on self-made hollow activated carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Kong Yuxia; Qiu Tingting [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Qiu Jun, E-mail: qiujun@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Key Laboratory of Advanced Civil Engineering Materials of Education of Ministry, Shanghai 201804 (China)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Hollow pipe and porous HACF with solid carbon net framework structure were successfully prepared by template method. Black-Right-Pointing-Pointer CNTs were grown successfully on the self-made HACF substrate by CVD techniques. Black-Right-Pointing-Pointer A novel tree-like micro-nano carbonous structure CNTs/HACF was fabricated. Black-Right-Pointing-Pointer The formation mechanism of micro phase HACF and nano phase CNTs were respectively discussed. - Abstract: The hollow activated carbon fibers (HACF) were prepared by using commercial polypropylene hollow fiber (PPHF) as the template, and phenol-formaldehyde resin (PF) as carbon precursors. Final HACF was formed through the thermal decomposition and carbonization of PF at 700 Degree-Sign C under the nitrogen atmosphere, and activation at 800 Degree-Sign C with carbon dioxide as the activating agent, consecutively. Then, carbon nanotubes (CNTs) were grown by chemical vapor deposition (CVD) techniques using the as-grown porous HACF as substrate. The growth process was achieved by pyrolyzing ethanol steam at 700 Degree-Sign C using nickel as catalyst. Finally, CNTs was grown successfully on the substrate, and a novel tree-like micro-nano carbonous structure CNTs/HACF was fabricated. The as-grown HACF and micro-nano CNTs/HACF were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TG), respectively. Moreover, the formation mechanisms were also discussed.

  15. Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors

    Directory of Open Access Journals (Sweden)

    Farshad Barzegar

    2015-09-01

    Full Text Available This article is focused on polymer based gel electrolyte due to the fact that polymers are cheap and can be used to achieve extended potential window for improved energy density of the supercapacitor devices when compared to aqueous electrolytes. Electrochemical characterization of a symmetric supercapacitor devices based on activated carbon in different polyvinyl alcohol (PVA based gel electrolytes was carried out. The device exhibited a maximum energy density of 24 Wh kg−1 when carbon black was added to the gel electrolyte as conductive additive. The good energy density was correlated with the improved conductivity of the electrolyte medium which is favorable for fast ion transport in this relatively viscous environment. Most importantly, the device remained stable with no capacitance lost after 10,000 cycles.

  16. Effects of peroxyacetyl nitrate (PAN) on vegetation. I. Herbaceous plants PAN injury symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Nouchi, I.; Iijima, T.; Oodaira, T.

    1975-01-01

    A series of exposure experiments were conducted in a controlled-atmosphere exposure chamber equipped with artificial light apparatus, using PAN synthesized from ultraviolet irradiation of ethyl nitrite vapor in oxygen. Exposures of 6 approx. 16 hours and 10 pphm PAN caused serious damage like caving with glazing or bronzing in caved lesions to the lower surface of younger leaves. Leaves of white-flowered petunia were found to be most sensitive to PAN and were damaged even by a 3 pphm exposure. Microscopic examinations showed that the PAN characteristically caused injuries of spongy cells and that these cells collapsed and turned brown. Leaf injury symptoms on herbaceous plants caused by synthesized PAN in the exposure experiments were found to be quite similar to those seen in the field under high oxidant emergence. Therefore, it seems that the said type of injuries to leaf beet, kidney bean, and head lettuce observed in the field were caused by PAN. 21 references. 4 figures, 3 tables.

  17. Performance of Lithium Polymer Cells with Polyacrylonitrile based Electrolyte

    DEFF Research Database (Denmark)

    Perera, Kumudu; Dissanayake, M.A.K.L.; Skaarup, Steen

    2006-01-01

    The performance of lithium polymer cells fabricated with Polyacrylonitrile (PAN) based electrolytes was studied using cycling voltammetry and continuous charge discharge cycling. The electrolytes consisted of PAN, ethylene carbonate (EC), propylene carbonate (PC) and lithium...... trifluoromethanesulfonate (LiCF3SO3 – LiTF). The polymer electrode material was polypyrrole (PPy) doped with dodecyl benzene sulfonate (DBS). The cells were of the form, Li / PAN : EC : PC : LiCF3SO3 / PPy : DBS. Polymer electrodes of three different thicknesses were studied using cycling at different scan rates. All cells...

  18. Carbon-Based Supercapacitors Produced by Activation of Graphene

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Y.; Su, D.; Murali, S.; Stoller, M.D.; Ganesh, K.J.; Cai, W.; Ferreira, P.J.; Pirkle, A.; Wallace, R.M.; Cychosz, K.A., Thommes, M.; Stach, E.A.; Ruoff, R.S.

    2011-06-24

    Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp{sup 2}-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

  19. Carbon-Based Supercapacitors Produced by Activation of Graphene

    Science.gov (United States)

    Zhu, Yanwu; Murali, Shanthi; Stoller, Meryl D.; Ganesh, K. J.; Cai, Weiwei; Ferreira, Paulo J.; Pirkle, Adam; Wallace, Robert M.; Cychosz, Katie A.; Thommes, Matthias; Su, Dong; Stach, Eric A.; Ruoff, Rodney S.

    2011-06-01

    Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp2-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

  20. Carbon-based Supercapacitors Produced by Activation of Graphene

    Energy Technology Data Exchange (ETDEWEB)

    Y Zhu; S Murali; M Stoller; K Ganesh; W Cai; P Ferreira; A Pirkle; R Wallace; K Cychosz; et al.

    2011-12-31

    Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp{sup 2}-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

  1. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    International Nuclear Information System (INIS)

    Liu Qingsong; Zheng Tong; Li Nan; Wang Peng; Abulikemu, Gulizhaer

    2010-01-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N 2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N 2 adsorption, acid-base titration, point of zero charge (pH pzc ) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH pzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  2. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Liu Qingsong; Zheng Tong; Li Nan [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Wang Peng, E-mail: pwang73@vip.sina.com [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Abulikemu, Gulizhaer [State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2010-03-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N{sub 2} atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N{sub 2} adsorption, acid-base titration, point of zero charge (pH{sub pzc}) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH{sub pzc} value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  3. Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

    Science.gov (United States)

    Liu, Qing-Song; Zheng, Tong; Li, Nan; Wang, Peng; Abulikemu, Gulizhaer

    2010-03-01

    Modification of bamboo-based activated carbon was carried out in a microwave oven under N 2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N 2 adsorption, acid-base titration, point of zero charge (pH pzc) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH pzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

  4. Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

    NARCIS (Netherlands)

    Wagner, Fabien H.; Hérault, Bruno; Bonal, Damien; Stahl, Clément; Anderson, Liana O.; Baker, Timothy R.; Becker, Gabriel Sebastian; Beeckman, Hans; Boanerges Souza, Danilo; Botosso, Paulo Cesar; Bowman, David M.J.S.; Bräuning, Achim; Brede, Benjamin; Brown, Foster Irving; Camarero, Jesus Julio; Camargo, Plínio Barbosa; Cardoso, Fernanda C.G.; Carvalho, Fabrício Alvim; Castro, Wendeson; Chagas, Rubens Koloski; Chave, Jérome; Chidumayo, Emmanuel N.; Clark, Deborah A.; Costa, Flavia Regina Capellotto; Couralet, Camille; Silva Mauricio, Da Paulo Henrique; Dalitz, Helmut; Castro, De Vinicius Resende; Freitas Milani, De Jaçanan Eloisa; Oliveira, De Edilson Consuelo; Souza Arruda, De Luciano; Devineau, Jean-Louis; Drew, David M.; Dünisch, Oliver; Durigan, Giselda; Elifuraha, Elisha; Fedele, Marcio; Ferreira Fedele, Ligia; Figueiredo Filho, Afonso; Finger, César Augusto Guimarães; Franco, Augusto César; Freitas Júnior, João Lima; Galvão, Franklin; Gebrekirstos, Aster; Gliniars, Robert; Lima De Alencastro Graça, Paulo Maurício; Griffiths, Anthony D.; Grogan, James; Guan, Kaiyu; Homeier, Jürgen; Kanieski, Maria Raquel; Kho, Lip Khoon; Koenig, Jennifer; Kohler, Sintia Valerio; Krepkowski, Julia; Lemos-filho, José Pires; Lieberman, Diana; Lieberman, Milton Eugene; Lisi, Claudio Sergio; Longhi Santos, Tomaz; López Ayala, José Luis; Maeda, Eduardo Eijji; Malhi, Yadvinder; Maria, Vivian R.B.; Marques, Marcia C.M.; Marques, Renato; Maza Chamba, Hector; Mbwambo, Lawrence; Melgaço, Karina Liana Lisboa; Mendivelso, Hooz Angela; Murphy, Brett P.; O'Brien, Joseph J.; Oberbauer, Steven F.; Okada, Naoki; Pélissier, Raphaël; Prior, Lynda D.; Roig, Fidel Alejandro; Ross, Michael; Rossatto, Davi Rodrigo; Rossi, Vivien; Rowland, Lucy; Rutishauser, Ervan; Santana, Hellen; Schulze, Mark; Selhorst, Diogo; Silva, Williamar Rodrigues; Silveira, Marcos; Spannl, Susanne; Swaine, Michael D.; Toledo, José Julio; Toledo, Marcos Miranda; Toledo, Marisol; Toma, Takeshi; Tomazello Filho, Mario; Valdez Hernández, Juan Ignacio; Verbesselt, Jan; Vieira, Simone Aparecida; Vincent, Grégoire; Volkmer De Castilho, Carolina; Volland, Franziska; Worbes, Martin; Zanon, Magda Lea Bolzan; Aragão, Luiz E.O.C.

    2016-01-01

    The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68

  5. Analysis list: pan [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available pan Embryo,Larvae,Pupae + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target.../pan.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/pan.5.tsv http://dbarchive.biosciencedbc.jp.../kyushu-u/dm3/target/pan.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/pan.Embryo.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/colo/pan.Larvae.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/colo/pan.Pupae.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Embryo.gml,http://dbarchive.bioscience

  6. Evaluation of water balance parameters from isotopic measurements in evaporation pans

    International Nuclear Information System (INIS)

    Allison, G.B.

    1979-01-01

    The evaluation of the parameters governing the isotopic composition of evaporating water bodies was attempted by means of evaporation pans. The instability of the meteorological conditions, however, makes it virtually impossible to evaluate the atmospheric relative humidity and its isotopic composition with pans. Pans are only suitable to obtain seasonal trends of the isotopic composition of the net evaporated water. For this, a technique based on two pans is also proposed. (author)

  7. ADSORPTION PROPERTIES OF NICKEL-BASED MAGNETIC ACTIVATED CARBON PREPARED BY PD-FREE ELECTROLESS PLATING

    Directory of Open Access Journals (Sweden)

    Boyang Jia

    2011-02-01

    Full Text Available Nickel-based magnetic activated carbon was synthesized from coconut shell activated carbon by electroless plating with palladium-free activation. The effect of plating solution volume on metallic ratio and adsorption capacity were evaluated. The effect of metallic ratio on specific area, pore volume, and magnetic properties were investigated. The morphologies of activated carbon before and after plating were observed by SEM, and the composition of the layer was analyzed by EDS analysis. The results showed that the metallic ratio was increased with the increase of the plating solution volume. The magnetic activated carbon showed high adsorption capacity for methylene blue and a high iodine number. Those values reached 142.5 mg/g and 1035 mg/g, respectively. The specific area and pore volume decreased from 943 m2/g to 859 m2/g and 0.462 ml/g to 0.417 ml/g, respectively. And the layer was more compact and continuous when the metallic ratio reached 16.37 wt.%. In the layer, there was about 97 wt.% nickel and 3 wt.% phosphorus, which indicates that the layer was a low-phosphorus one. At the same time, magnetism was enhanced, making the product suitable for some special applications.

  8. Structure and functionality of PVdF/PAN based, composite proton conducting membranes

    International Nuclear Information System (INIS)

    Martinelli, A.; Navarra, M.A.; Matic, A.; Panero, S.; Jacobsson, P.; Boerjesson, L.; Scrosati, B.

    2005-01-01

    We have investigated new poly-vinylidene fluoride/poly-acrylonitrile (PVdF/PAN) based proton conducting membranes by means of vibrational spectroscopy. We find that a complete phase inversion occurs during the preparation procedure, when the gelling solvents are replaced by an acidic solution, providing the proton conducting property. The uptake of acid is promoted both by the presence of PAN and the ceramic filler, Al 2 O 3 . No particular interaction between the polymer matrix and the acidic solution could be detected, supporting the picture of an inert matrix entrapping a liquid component. However, the dissociation degree of the acid is decreased due to the spatial confinement in the membrane. By comparing the dissociation degree and the actual amount of acid in the membrane to the conductivity, we conclude that the limiting factor for the conductivity is the long-range mobility of the protons, which is governed by the morphology of the membrane

  9. Adsorption of phenol by activated carbon: Influence of activation methods and solution pH

    International Nuclear Information System (INIS)

    Beker, Ulker; Ganbold, Batchimeg; Dertli, Halil; Guelbayir, Dilek Duranoglu

    2010-01-01

    Cherry stone based activated carbon derived from a canning industry was evaluated for its ability to remove phenol from an aqueous solution in a batch process. A comparative adsorption on the uptake of phenol by using commercial activated carbon (Chemviron CPG-LF), and two non-functional commercial polymeric adsorbents (MN-200 and XAD-2) containing a styrene-divinylbenzene macroporous hyperreticulated network have been also examined. Equilibrium studies were conducted in 25 mg L -1 initial phenol concentrations, 6.5-9 solution pH and at temperature of 30 deg. C. The experimental data were analyzed by the Langmuir and Freundlich isotherm models. Besides, the cherry stone based activated carbons were carried out by using zinc chloride and KOH activation agents at different chemical ratios (activating agent/precursor), to develop carbons with well-developed porosity. The cherry stone activated carbon prepared using KOH as a chemical agent showed a high surface area. According to the results, activated carbons had excellent adsorptive characteristics in comparison with polymeric sorbents and commercial activated carbon for the phenol removal from the aqueous solutions.

  10. Removal Of Labeled ALPHA-Fetoprotein (AFP) Using Rice Husk-Based Activated Carbon

    International Nuclear Information System (INIS)

    ABDEL-MOUHTY, N.R.

    2009-01-01

    Biomass agricultural waste materials, rice husk (RH) or saw dust (SD), were used for the preparation of activated carbons. RH was activated by chemical activation using phosphoric acid or potassium hydroxide. The prepared activated carbons were characterized and used for the adsorption of labeled alpha-fetoprotein ( 125 I-AFP) from the lab waste of iodine labeled alpha-fetoprotein tracer. The effects of various factors, e.g. carbon type, carbon dosage, temperature, particle size of carbon, effect of different waste volumes on the adsorption capacity, were quantitatively determined. Desorption of activated carbon was also investigated. From the experimental results, it was found that SDK had the lowest ability for adsorption of 125I-AFP and the highest uptake was 83% by carbon RHH. The amount of adsorption accomplished per unit weight of a solid adsorbent was greater, the more finely divided and the more porous the solid. 0.5 g for RHH carbon was found to be optimum dose of adsorbent for the removal of 125I-AFP. The optimum volume of waste with 0.5 g dose of RHH was 15 ml. The increased adsorption with temperature may be due to the increase of the intra-particle diffusion rate of sorbate ions into the pores at higher temperature as diffusion is an endothermic process.

  11. Surface functionalization of carbon nanofibers by sol-gel coating of zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Shao Dongfeng [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Changzhou Textile Garment Institute, Changzhou 213164 (China); Wei Qufu [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)], E-mail: qfwei@jiangnan.edu.cn; Zhang Liwei; Cai Yibing; Jiang Shudong [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)

    2008-08-15

    In this paper the functional carbon nanofibers were prepared by the carbonization of ZnO coated PAN nanofibers to expand the potential applications of carbon nanofibers. Polyacrylonitrile (PAN) nanofibers were obtained by electrospinning. The electrospun PAN nanofibers were then used as substrates for depositing the functional layer of zinc oxide (ZnO) on the PAN nanofiber surfaces by sol-gel technique. The effects of coating, pre-oxidation and carbonization on the surface morphology and structures of the nanofibers were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM), respectively. The results of SEM showed a significant increase of the size of ZnO nanograins on the surface of nanofibers after the treatments of coating, pre-oxidation and carbonization. The observations by SEM also revealed that ZnO nanoclusters were firmly and clearly distributed on the surface of the carbon nanofibers. FTIR examination also confirmed the deposition of ZnO on the surface of carbon nanofibers. The XRD analysis indicated that the crystal structure of ZnO nanograins on the surface of carbon nanofibers.

  12. Real-Time Acquisition of High Quality Face Sequences from an Active Pan-Tilt-Zoom Camera

    DEFF Research Database (Denmark)

    Haque, Mohammad A.; Nasrollahi, Kamal; Moeslund, Thomas B.

    2013-01-01

    -based real-time high-quality face image acquisition system, which utilizes pan-tilt-zoom parameters of a camera to focus on a human face in a scene and employs a face quality assessment method to log the best quality faces from the captured frames. The system consists of four modules: face detection, camera...... control, face tracking, and face quality assessment before logging. Experimental results show that the proposed system can effectively log the high quality faces from the active camera in real-time (an average of 61.74ms was spent per frame) with an accuracy of 85.27% compared to human annotated data.......Traditional still camera-based facial image acquisition systems in surveillance applications produce low quality face images. This is mainly due to the distance between the camera and subjects of interest. Furthermore, people in such videos usually move around, change their head poses, and facial...

  13. PanViz: interactive visualization of the structure of functionally annotated pangenomes

    DEFF Research Database (Denmark)

    Pedersen, Thomas Lin; Nookaew, Intawat; Wayne Ussery, David

    2017-01-01

    with gene ontology based navigation of gene groups. Furthermore it allows for rich and complex visual querying of gene groups in the pangenome. PanViz visualizations require no external programs and are easily sharable, allowing for rapid pangenome analyses. PanViz is written entirely in Java......PanViz is a novel, interactive, visualization tool for pangenome analysis. PanViz allows visualization of changes in gene group (groups of similar genes across genomes) classification as different subsets of pangenomes are selected, as well as comparisons of individual genomes to pangenomes......Script and is available on https://github.com/thomasp85/PanViz A companion R package that facilitates the creation of PanViz visualizations from a range of data formats is released through Bioconductor and is available at https://bioconductor.org/packages/PanVizGenerator CONTACT: thomasp85@gmail...

  14. Pan-ebolavirus and Pan-filovirus Mouse Monoclonal Antibodies: Protection against Ebola and Sudan Viruses.

    Science.gov (United States)

    Holtsberg, Frederick W; Shulenin, Sergey; Vu, Hong; Howell, Katie A; Patel, Sonal J; Gunn, Bronwyn; Karim, Marcus; Lai, Jonathan R; Frei, Julia C; Nyakatura, Elisabeth K; Zeitlin, Larry; Douglas, Robin; Fusco, Marnie L; Froude, Jeffrey W; Saphire, Erica Ollmann; Herbert, Andrew S; Wirchnianski, Ariel S; Lear-Rooney, Calli M; Alter, Galit; Dye, John M; Glass, Pamela J; Warfield, Kelly L; Aman, M Javad

    2016-01-01

    The unprecedented 2014-2015 Ebola virus disease (EVD) outbreak in West Africa has highlighted the need for effective therapeutics against filoviruses. Monoclonal antibody (MAb) cocktails have shown great potential as EVD therapeutics; however, the existing protective MAbs are virus species specific. Here we report the development of pan-ebolavirus and pan-filovirus antibodies generated by repeated immunization of mice with filovirus glycoproteins engineered to drive the B cell responses toward conserved epitopes. Multiple pan-ebolavirus antibodies were identified that react to the Ebola, Sudan, Bundibugyo, and Reston viruses. A pan-filovirus antibody that was reactive to the receptor binding regions of all filovirus glycoproteins was also identified. Significant postexposure efficacy of several MAbs, including a novel antibody cocktail, was demonstrated. For the first time, we report cross-neutralization and in vivo protection against two highly divergent filovirus species, i.e., Ebola virus and Sudan virus, with a single antibody. Competition studies indicate that this antibody targets a previously unrecognized conserved neutralizing epitope that involves the glycan cap. Mechanistic studies indicated that, besides neutralization, innate immune cell effector functions may play a role in the antiviral activity of the antibodies. Our findings further suggest critical novel epitopes that can be utilized to design effective cocktails for broad protection against multiple filovirus species. Filoviruses represent a major public health threat in Africa and an emerging global concern. Largely driven by the U.S. biodefense funding programs and reinforced by the 2014 outbreaks, current immunotherapeutics are primarily focused on a single filovirus species called Ebola virus (EBOV) (formerly Zaire Ebola virus). However, other filoviruses including Sudan, Bundibugyo, and Marburg viruses have caused human outbreaks with mortality rates as high as 90%. Thus, cross

  15. 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)

  16. Electrochemically Active Polymeric Hollow Fibers based on Poly(ether- b -amide)/Carbon Nanotubes

    KAUST Repository

    Cuevas, Carolina

    2017-09-18

    A simple and effective method to incorporate catalytic activity to a hollow fiber membrane is reported. Polyetherimide hollow fiber membranes were coated with a solution containing carboxyl-functionalized multi-walled carbon nanotubes and poly(ether-b-amide). Electron microscopy images confirmed the presence of a layer of percolating carbon nanotubes on the surface of the membranes. Cyclic voltammetry and linear swept voltammetry experiments showed that these membranes are able to drive the reactions of hydrogen evolution, and oxygen reduction, making them a cheaper, and greener substitute for platinum based cathodes in microbial bioelectrochemical systems. Water flux and molecular weight cut off experiments indicated that the electrochemically active coating layer does not affect the ultrafiltration performance of the membrane.

  17. Electrochemically Active Polymeric Hollow Fibers based on Poly(ether- b -amide)/Carbon Nanotubes

    KAUST Repository

    Cuevas, Carolina; Kim, Dooli; Katuri, Krishna; Saikaly, Pascal; Nunes, Suzana Pereira

    2017-01-01

    A simple and effective method to incorporate catalytic activity to a hollow fiber membrane is reported. Polyetherimide hollow fiber membranes were coated with a solution containing carboxyl-functionalized multi-walled carbon nanotubes and poly(ether-b-amide). Electron microscopy images confirmed the presence of a layer of percolating carbon nanotubes on the surface of the membranes. Cyclic voltammetry and linear swept voltammetry experiments showed that these membranes are able to drive the reactions of hydrogen evolution, and oxygen reduction, making them a cheaper, and greener substitute for platinum based cathodes in microbial bioelectrochemical systems. Water flux and molecular weight cut off experiments indicated that the electrochemically active coating layer does not affect the ultrafiltration performance of the membrane.

  18. [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.

  19. Real-Time Penetrating Particle Analyzer (PAN)

    Science.gov (United States)

    Wu, X.; Ambrosi, G.; Bertucci, B.

    2018-02-01

    The PAN can measure penetrating particles with great precision to study energetic particles, solar activities, and the origin and propagation of cosmic rays. The real-time monitoring of penetrating particles is crucial for deep space human travel.

  20. HOW TO PAN-SHARPEN IMAGES USING THE GRAM-SCHMIDT PAN-SHARPEN METHOD – A RECIPE

    Directory of Open Access Journals (Sweden)

    T. Maurer

    2013-05-01

    Full Text Available Since its publication in 1998 (Laben and Brower, 2000, the Gram-Schmidt pan-sharpen method has become one of the most popular algorithms to pan-sharpen multispectral (MS imagery. It outperforms most other pan-sharpen methods in both maximizing image sharpness and minimizing color distortion. It is, on the other hand, also more complex and computationally expensive than most other methods, as it requires forward and backward transforming the entire image. Another complication is the lack of a clear recipe of how to compute the sensor dependent MS to Pan weights that are needed to compute the simulated low resolution pan band. Estimating them from the sensor’s spectral sensitivity curves (in different ways, or using linear regression or least square methods are typical candidates which can include other degrees of freedom such as adding a constant offset or not. As a result, most companies and data providers do it somewhat differently. Here we present a solution to both problems. The transform coefficients can be computed directly and in advance from the MS covariance matrix and the MS to Pan weights. Once the MS covariance matrix is computed and stored with the image statistics, any small section of the image can be pan-sharpened on the fly, without having to compute anything else over the entire image. Similarly, optimal MS to Pan weights can be computed directly from the full MS-Pan covariance matrix, guaranteeing optimal image quality and consistency.

  1. Optimization of microwave-assisted durian seed based activated carbon preparation conditions for methylene blue dye removal

    Science.gov (United States)

    Ahmad, Mohd Azmier; Hamid, Siti Ruqayyah Ab.; Yusop, Mohamad Firdaus Mohamad; Aziz, Hamidi Abdul

    2017-10-01

    Due to easy access and relatively high fixed carbon content of 26.13% in its raw form, durian seed based activated carbon (DSAC) was produced via microwave heating. For activation stage, physiochemical approach consist of carbon dioxide (CO2) gasification and potassium hydroxide (KOH) as chemical activator were employed. Three most influential preparation variables on adsorption performance and yield of activated carbon (AC), which is radiation power, radiation time and KOH impregnation ratio (IR) were optimized with the help of response surface methodology (RSM). The optimization result revealed that 440W, 4.0 minutes and 0.55 of radiation power, radiation time and IR respectively, were needed to remove 80.23% of methylene blue (MB) dye and to obtain 25.77% of DSAC's yield. High Brunauer-Emmet-Teller (BET) surface area, total pore volume and average pore size of 852.30m2/g, 0.465cm3/g and 3.74nm respectively, were obtained on optimized DSAC.

  2. Mechanochemically Activated, Calcium Oxide-Based, Magnesium Oxide-Stabilized Carbon Dioxide Sorbents.

    Science.gov (United States)

    Kurlov, Alexey; Broda, Marcin; Hosseini, Davood; Mitchell, Sharon J; Pérez-Ramírez, Javier; Müller, Christoph R

    2016-09-08

    Carbon dioxide capture and storage (CCS) is a promising approach to reduce anthropogenic CO2 emissions and mitigate climate change. However, the costs associated with the capture of CO2 using the currently available technology, that is, amine scrubbing, are considered prohibitive. In this context, the so-called calcium looping process, which relies on the reversible carbonation of CaO, is an attractive alternative. The main disadvantage of naturally occurring CaO-based CO2 sorbents, such as limestone, is their rapid deactivation caused by thermal sintering. Here, we report a scalable route based on wet mechanochemical activation to prepare MgO-stabilized, CaO-based CO2 sorbents. We optimized the synthesis conditions through a fundamental understanding of the underlying stabilization mechanism, and the quantity of MgO required to stabilize CaO could be reduced to as little as 15 wt %. This allowed the preparation of CO2 sorbents that exceed the CO2 uptake of the reference limestone by 200 %. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. O pan das ánimas

    OpenAIRE

    Antón, Fina; Mandianes Castro, Manuel

    1996-01-01

    O pan, ademais de cumprir una función alimenticia de primeira orde, está revestido dunha significación simbólica importante. O pan durante a vida axuda a pasa-los límites, a da-lo paso, a integrarse entre os cristiáns por cousa do bautismo e a integrarse no grupo dos homes e mulleres co adaxo da boda, pero o pan axuda, sobre todo, a pasa-lo río Xordán, que é, sen dúbida o límite que separa este mundo do outro; a serpe e as ánimas constitúen un límite e o pan facilita o seu paso. O pan está in...

  4. Nitrogen-enriched bituminous coal-based active carbons as materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    R. Pietrzak; K. Jurewicz; P. Nowicki; K. Babel; H. Wachowska [A. Mickiewicz University, Poznan (Poland). Laboratory of Coal Chemistry and Technology

    2010-11-15

    The paper presents the results of a study on obtaining N-enriched active carbons from bituminous coal and on testing its use as an electrode material in supercapacitors. The coal was carbonised, activated with KOH and ammoxidised by a mixture of ammonia and air at the ratio 1:3 at 300{sup o}C or 350{sup o}C, at different stages of the production, that is, at those of precursor, carbonisate, and active carbon. The products were microporous N-enriched active carbon samples of well-developed surface area reaching from 1577 to 2510 m{sup 2}/g and containing 1.0 to 8.5 wt% of nitrogen. The XPS measurements have shown that in the active carbons enriched in nitrogen at the stage of precursor and at the stage of carbonisate, the dominant nitrogen species are the N-5 groups, while in the samples ammoxidised at the last stage of the treatment the dominant nitrogen species are the surface groups of imines and/or nitriles, probably accompanied by amines and amides. The paper reports the results of a comprehensive study of the effect of the structure and chemical composition of a series of active carbon samples of different properties on their capacity performance in water solutions of H{sub 2}SO{sub 4} or KOH, with the behaviour of positive and negative electrodes analysed separately. 33 refs., 7 figs., 8 tabs.

  5. Design of an Enterobacteriaceae Pan-genome Microarray Chip

    DEFF Research Database (Denmark)

    Lukjancenko, Oksana; Ussery, David

    2010-01-01

    -density microarray chip has been designed, using 116 Enterobacteriaceae genome sequences, taking into account the enteric pan-genome. Probes for the microarray were checked in silico and performance of the chip, based on experimental strains from four different genera, demonstrate a relatively high ability...... to distinguish those strains on genus, species, and pathotype/serovar levels. Additionally, the microarray performed well when investigating which genes were found in a given strain of interest. The Enterobacteriaceae pan-genome microarray, based on 116 genomes, provides a valuable tool for determination...

  6. Surface modification of carbon fibers and its effect on the fiber–matrix interaction of UHMWPE based composites

    International Nuclear Information System (INIS)

    Chukov, D.I.; Stepashkin, A.A.; Gorshenkov, M.V.; Tcherdyntsev, V.V.; Kaloshkin, S.D.

    2014-01-01

    Highlights: • Both chemical and thermal treatments of UKN 5000 carbon fibers allow one to obtain well-developed surface. • The changes of structure and properties of VMN-4 fibers after both thermal and chemical oxidation are insignificant due to more perfect initial structure of these fibers. • The oxidative treatment of carbon fibers allows one to improve the interfacial interaction in the UHMWPE-based composites. • The oxidative treatment of the fibers allows one to a triple increase of Young’s modulus of the modified fibers reinforced UHMWPE composites. -- Abstract: The PAN-based carbon fibers (CF) were subjected to thermal and chemical oxidation under various conditions. The variation in the surface morphology of carbon fibers after surface treatment was analyzed by scanning electron microscopy (SEM). It was found that the tensile strength of carbon fibers changed after surface modification. The interaction between the fibers and the matrix OF ultra-high molecular weight polyethylene (UHMWPE) was characterized by the Young modulus of produced composites. It was shown that the Young modulus of composites reinforced with modified carbon fibers was significantly higher than that of composites reinforced with non-modified fibers

  7. High energy (MeV) ion-irradiated π-conjugated polyaniline: Transition from insulating state to carbonized conducting state

    International Nuclear Information System (INIS)

    Park, S.K.; Lee, S.Y.; Lee, C.S.; Kim, H.M.; Joo, J.; Beag, Y.W.; Koh, S.K.

    2004-01-01

    High energy (MeV) C 2+ , F 2+ , and Cl 2+ ions were irradiated onto π-conjugated polyaniline emeraldine base (PAN-EB) samples. The energy of an ion beam was controlled to a range of 3-4.5 MeV, with the ion dosage varying from 1x10 12 to 1x10 16 ions/cm 2 . The highest dc conductivity (σ dc ) at room temperature was measured to be ∼60 S/cm for 4.5 MeV Cl 2+ ion-irradiated PAN-EB samples with a dose of 1x10 16 ions/cm 2 . We observed the transition of high energy ion-irradiated PAN-EB samples from insulating state to conducting state as a function of ion dosage based on σ dc and its temperature dependence. The characteristic peaks of the Raman spectrum of the PAN-EB samples were reduced, while the D-peak (disordered peak) and the G peak (graphitic peak) appeared as the ion dose increased. From the analysis of the D and G peaks of the Raman spectra of the systems compared to multiwalled carbon nanotubes, ion-irradiated graphites, and annealed carbon films, the number of the clusters of hexagon rings with conducting sp 2 -bonded carbons increased with ion dosage. We also observed the increase in the size of the nanocrystalline graphitic domain of the systems with increasing ion dosage. The intensity of normalized electron paramagnelic resonance signal also increased in correlation with ion dose. The results of this study demonstrate that π-conjugated pristine PAN-EB systems changed from insulating state to carbonized conducting state through high energy ion irradiation with high ion dosage

  8. Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

    Science.gov (United States)

    Fabien H. Wagner; Bruno Herault; Damien Bonal; Clement Stahl; Liana O. Anderson; Timothy R. Baker; Gabriel Sebastian Becker; Hans Beeckman; Danilo Boanerges Souza; Paulo Cesar Botosso; David M. J. S. Bowman; Achim Brauning; Benjamin Brede; Foster Irving Brown; Jesus Julio Camarero; Plinio Barbosa Camargo; Fernanda C. G. Cardoso; Fabricio Alvim Carvalho; Wendeson Castro; Rubens Koloski Chagas; Jerome Chave; Emmanuel N. Chidumayo; Deborah A. Clark; Flavia Regina Capellotto Costa; Camille Couralet; Paulo Henrique da Silva Mauricio; Helmut Dalitz; Vinicius Resende de Castro; Jacanan Eloisa de Freitas Milani; Edilson Consuelo de Oliveira; Luciano de Souza Arruda; Jean-Louis Devineau; David M. Drew; Oliver Dunisch; Giselda Durigan; Elisha Elifuraha; Marcio Fedele; Ligia Ferreira Fedele; Afonso Figueiredo Filho; Cesar Augusto Guimaraes Finger; Augusto Cesar Franco; Joao Lima Freitas Junior; Franklin Galvao; Aster Gebrekirstos; Robert Gliniars; Paulo Mauricio Lima de Alencastro Graca; Anthony D. Griffiths; James Grogan; Kaiyu Guan; Jurgen Homeier; Maria Raquel Kanieski; Lip Khoon Kho; Jennifer Koenig; Sintia Valerio Kohler; Julia Krepkowski; Jose Pires Lemos-Filho; Diana Lieberman; Milton Eugene Lieberman; Claudio Sergio Lisi; Tomaz Longhi Santos; Jose Luis Lopez Ayala; Eduardo Eijji Maeda; Yadvinder Malhi; Vivian R. B. Maria; Marcia C. M. Marques; Renato Marques; Hector Maza Chamba; Lawrence Mbwambo; Karina Liana Lisboa Melgaco; Hooz Angela Mendivelso; Brett P. Murphy; Joseph O' Brien; Steven F. Oberbauer; Naoki Okada; Raphael Pelissier; Lynda D. Prior; Fidel Alejandro Roig; Michael Ross; Davi Rodrigo Rossatto; Vivien Rossi; Lucy Rowland; Ervan Rutishauser; Hellen Santana; Mark Schulze; Diogo Selhorst; Williamar Rodrigues Silva; Marcos Silveira; Susanne Spannl; Michael D. Swaine; Jose Julio Toledo; Marcos Miranda Toledo; Marisol Toledo; Takeshi Toma; Mario Tomazello Filho; Juan Ignacio Valdez Hernandez; Jan Verbesselt; Simone Aparecida Vieira; Gregoire Vincent; Carolina Volkmer de Castilho; Franziska Volland; Martin Worbes; Magda Lea Bolzan Zanon; Luiz E. O. C. Aragao

    2016-01-01

    The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter...

  9. 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

  10. Removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution using rice husk-based activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Mohd F., E-mail: faisalt@petronas.com.my; Shaharun, Maizatul S. [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia); Shuib, Anis Suhaila, E-mail: anisuha@petronas.com.my; Borhan, Azry [Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia)

    2014-10-24

    An attempt was made to investigate the potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Rice husk-based activated carbon was prepared via treatment of rice husk with NaOH followed by the carbonization process at 400°C for 2 hours. Three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon, were analyzed for their morphological characteristics using field-emission scanning electron microscope/energy dispersive X-ray (FESEM/EDX). These samples were also analyzed for their carbon, hydrogen, nitrogen, oxygen and silica contents using CHN elemental analyzer and FESEM/EDX. The porous properties of rice husk-based activated carbon were determined by Brunauer-Emmett-Teller (BET) surface area analyzer, and its surface area and pore volume were 255 m{sup 2}/g and 0.17 cm{sup 2}/g, respectively. The adsorption studies for the removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution were carried out at a fixed initial concentration of metal ion (150 ppm) with variation amount of adsorbent (rice husk-based activated carbon) as a function of varied contact time at room temperature. The concentration of each metal ion was analyzed using atomic absorption spectrophotometer (AAS). The results obtained from adsorption studies indicate the potential of rice husk as an economically promising precursor for the preparation of activated carbon for removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Isotherm and kinetic model analyses suggested that the experimental data of adsorption studies fitted well with Langmuir, Freundlich and second-order kinetic models.

  11. Removal of an endocrine disrupting chemical (17 alpha-ethinyloestradiol) from wastewater effluent by activated carbon adsorption: Effects of activated carbon type and competitive adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Ifelebuegu, A.O.; Lester, J.N.; Churchley, J.; Cartmell, E. [Cranfield University, Cranfield (United Kingdom). School of Water Science

    2006-12-15

    Granular activated carbon has been extensively used for the adsorption of organic micropollutants for potable water production. In this study the removal of an endocrine disrupting chemical from wastewater final effluent by three types of granular activated carbon (wood, coconut and coal based) has been investigated in batch adsorption experiments and correlated with the removal of chemical oxygen demand (COD), total organic carbon (TOC) and ultraviolet absorbance (UV). The results obtained demonstrated 17 alpha-ethinyloestradiol (EE2) removals of 98.6%, 99.3%, and 96.4% were achieved by the coal based (ACo), coconut based (ACn) and wood based (AWd) carbons respectively at the lowest dose of carbon (0.1 gl{sup -1}). The other adsorbates investigated all exhibited good removal. At an equilibrium concentration of 7 mgl{sup -1} the COD adsorption capacities were 3.16 mg g{sup -1}, 4.8 mg g{sup -1} and 7.1 mg g{sup -1} for the wood, coconut and coal based carbons respectively. Overall, the order of removal efficiency of EE2 and the other adsorbates for the three activated carbons was ACn {gt} ACo {gt} AWd. The adsorption capacities of the carbons were found to be reduced by the effects of other competing adsorbates in the wastewater effluent.

  12. REMOVAL OF IMIDACLOPRID USING ACTIVATED CARBON ...

    African Journals Online (AJOL)

    KEY WORDS: Chemical activation, Adsorption, Activated carbon, Pesticide ..... density solvent based dispersive liquid–liquid microextraction for quantitative extraction of ... El-Hamouz, A.; Hilal, H.S.; Nassar, N.; Mardawi, Z. Solid olive waste in ...

  13. 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.)

  14. Exploring the emotional appeal of green and social Europe myths among pan-European Union organisations

    DEFF Research Database (Denmark)

    Lynggaard, Kennet

    2017-01-01

    : (1) pan-EU NGOs are receptive to political myths, including in the short term; (2) pan-EU NGOs contribute to the reproduction of myths, especially already-institutionalised myths and myths that resonate with their sectoral activities; and (3) pan-EU NGOs strategically use political myths to justify...

  15. Development of carbon/carbon composite control rod for HTTR. 1. Preparation of elements and their fracture tests

    International Nuclear Information System (INIS)

    Eto, Motokuni; Ishiyama, Shintaro; Ugachi, Hirokazu

    1996-08-01

    For the High Temperature Engineering Test Reactor(HTTR) the control rod sleeve is made of Alloy 800H for which a particular process is imposed when the reactor needs to be scrammed. The less restricted operation of the reactor would be attained if there would be the control rod more resistant to high temperature and neutron irradiation. This report summarizes the results which have been obtained as of March 1996 in the course of the development of the C/C composite control rod. Materials used were pitch- or PAN-based fiber-reinforced 2-dimensional carbon composites, from which preforms of the elements of a control rod were fabricated. The preforms were carbonized at 1000degC after being impregnated with pitch. Then they were graphitized at 3000degC, followed by a purification treatment with halogen. The elements included the pellet holder, lace truck and pin. The pin was fabricated by the fiber laminating technique. A control rod is to consist of pellet holders which are connected by the lace trucks with pins. Various strength tests were carried out on these elements. An irradiation of the elements made of PAN-based material was performed in JRR-3 at 900±50degC to a neutron fluence of 1x10 25 n/m 2 (E>29fJ). As for the strength tests on the elements, there were some differences between PAN- and pitch-based composites: In general, elements made of PAN-based composite showed the more plastic behavior before they fractured, whereas those of pitch-based material behaved in the more brittle manner. Fracture tests of the irradiated elements showed that fracture load and fracture displacement enough for assuring the integrity of the control rod structure were maintained even after the irradiation. It was also found that if the applied load was parallel to the fiber felt plane both fracture load and strain increased, whereas the load increase and strain decrease were observed for the applied load against the plane. (J.P.N.)

  16. Development of carbon/carbon composite control rod for HTTR. 1. Preparation of elements and their fracture tests

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Motokuni; Ishiyama, Shintaro; Ugachi, Hirokazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-08-01

    For the High Temperature Engineering Test Reactor(HTTR) the control rod sleeve is made of Alloy 800H for which a particular process is imposed when the reactor needs to be scrammed. The less restricted operation of the reactor would be attained if there would be the control rod more resistant to high temperature and neutron irradiation. This report summarizes the results which have been obtained as of March 1996 in the course of the development of the C/C composite control rod. Materials used were pitch- or PAN-based fiber-reinforced 2-dimensional carbon composites, from which preforms of the elements of a control rod were fabricated. The preforms were carbonized at 1000degC after being impregnated with pitch. Then they were graphitized at 3000degC, followed by a purification treatment with halogen. The elements included the pellet holder, lace truck and pin. The pin was fabricated by the fiber laminating technique. A control rod is to consist of pellet holders which are connected by the lace trucks with pins. Various strength tests were carried out on these elements. An irradiation of the elements made of PAN-based material was performed in JRR-3 at 900{+-}50degC to a neutron fluence of 1x10{sup 25} n/m{sup 2} (E>29fJ). As for the strength tests on the elements, there were some differences between PAN- and pitch-based composites: In general, elements made of PAN-based composite showed the more plastic behavior before they fractured, whereas those of pitch-based material behaved in the more brittle manner. Fracture tests of the irradiated elements showed that fracture load and fracture displacement enough for assuring the integrity of the control rod structure were maintained even after the irradiation. It was also found that if the applied load was parallel to the fiber felt plane both fracture load and strain increased, whereas the load increase and strain decrease were observed for the applied load against the plane. (J.P.N.)

  17. Facile preparation of well-combined lignin-based carbon/ZnO hybrid composite with excellent photocatalytic activity

    Science.gov (United States)

    Wang, Huan; Qiu, Xueqing; Liu, Weifeng; Yang, Dongjie

    2017-12-01

    In this work, a novel lignin-based carbon/ZnO (LC/ZnO) hybrid composite with excellent photocatalytic performance was prepared through a convenient and environment friendly method using alkali lignin (AL) as carbon source. The morphological, microstructure and optical properties of the as-prepared LC/ZnO hybrid composite was characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), Raman and UV-vis. The resulting LC/ZnO hybrid is composed of highly dispersed ZnO nanoparticles embedded on a lignin-based carbon nanosheet, showing excellent photogenerated electrons and holes separation and migration efficiency. The photocatalytic activity of LC/ZnO was much higher than the pure ZnO. The LC/ZnO hybrid composite showed different photocatalytic mechanism for degradation of negative methyl orange (MO) and positive Rhodamine B (RhB). It showed that h+ was the main photocatalytic active group during the degradation of MO, ·O2- and ·OH were the photocatalytic active groups during degradation of RhB. This reported photocatalyst with selective degradation of positive and negative organic dyes may have a great application prospect for photoelectric conversion and catalytic materials. Results of this work were of practical importance for high-valued utilization of lignin for carbon materials.

  18. Preparation and Electrochemical Properties of Silver Doped Hollow Carbon Nanofibers

    Directory of Open Access Journals (Sweden)

    LI Fu

    2016-11-01

    Full Text Available Silver doped PAN-based hollow carbon nanofibers were prepared combining co-electrospinning with in situ reduction technique subsequently heat treatment to improve the electrochemical performances of carbon based supercapacitor electrodes. The morphology, structure and electrochemical performances of the resulted nanofiber were studied. The results show that the silver nanoparticles can be doped on the surface of hollow carbon nanofibers and the addition of silver favors the improvement of the electrochemical performances, exhibiting the enhanced reversibility of electrode reaction and the capacitance and the reduced charge transfer impedance.

  19. Catalytic Effect of Activated Carbon and Activated Carbon Fiber in Non-Equilibrium Plasma-Based Water Treatment

    Science.gov (United States)

    Zhang, Yanzong; Zheng, Jingtang; Qu, Xianfeng; Yu, Weizhao; Chen, Honggang

    2008-06-01

    Catalysis and regeneration efficiency of granular activated carbon (GAC) and activated carbon fiber (ACF) were investigated in a non-equilibrium plasma water treatment reactor with a combination of pulsed streamer discharge and GAC or ACF. The experimental results show that the degradation efficiency of methyl orange (MO) by the combined treatment can increase 22% (for GAC) and 24% (for ACF) respectively compared to pulsed discharge treatment alone, indicating that the combined treatment has a synergetic effect. The MO degradation efficiency by the combined treatment with pulsed discharge and saturated GAC or ACF can increase 12% and 17% respectively compared to pulsed discharge treatment alone. Both GAC and ACF show catalysis and the catalysis of ACF is prominent. Meanwhile, the regeneration of GAC and ACF are realized in this process. When H2O2 is introduced into the system, the utilization efficiency of ozone and ultraviolet light is improved and the regeneration efficiency of GAC and ACF is also increased.

  20. Catalytic Effect of Activated Carbon and Activated Carbon Fiber in Non-Equilibrium Plasma-Based Water Treatment

    International Nuclear Information System (INIS)

    Zhang Yanzong; Zheng Jingtang; Qu Xianfeng; Yu Weizhao; Chen Honggang

    2008-01-01

    Catalysis and regeneration efficiency of granular activated carbon (GAC) and activated carbon fiber (ACF) were investigated in a non-equilibrium plasma water treatment reactor with a combination of pulsed streamer discharge and GAC or ACF. The experimental results show that the degradation efficiency of methyl orange (MO) by the combined treatment can increase 22% (for GAC) and 24% (for ACF) respectively compared to pulsed discharge treatment alone, indicating that the combined treatment has a synergetic effect. The MO degradation efficiency by the combined treatment with pulsed discharge and saturated GAC or ACF can increase 12% and 17% respectively compared to pulsed discharge treatment alone. Both GAC and ACF show catalysis and the catalysis of ACF is prominent. Meanwhile, the regeneration of GAC and ACF are realized in this process. When H 2 O 2 is introduced into the system, the utilization efficiency of ozone and ultraviolet light is improved and the regeneration efficiency of GAC and ACF is also increased.

  1. Results of a European interlaboratory comparison on CO2 sorption on activated carbon and coals

    Science.gov (United States)

    Gensterblum, Yves; Busch, Andreas; Krooss, Bernhard; de Weireld, Guy; Billemont, Pierre; van Hemert, Patrick; Wolf, Karl-Heinz

    2013-04-01

    -laboratory comparison of high pressure CO2 sorption isotherms. I: Activated carbon" Carbon 47 ( 2009 ) 2958 -2969 Goodman, A.L., Busch, A., Duffy, G., Fitzgerald, J.E., Gasem, K.A.M., Gensterblum, Y., Krooss, B.M., Levy, J., Ozdemir, E., Pan, Z., Robinson, Jr., R.L., Schroeder, K., Sudibandriyo, M., White, C. (2004). An Inter-laboratory Comparison of CO2 Isotherms Measured on Argonne Premium Coal Samples. Energy and Fuels 18, 1175-1182. Goodman, A.L., Busch, A., Day, S., Duffy, G.J., Fitzgerald, J.E., Gasem, K.A.M., Gensterblum, Y., Hartman, C., Krooss, B.M., Pan, Z., Pratt, T., Robinson, Jr., R.L., Romanov, V., Sakurovs, R., Schroeder, K., Sudibandriyo, M., White, C.M. (2007) "Inter-laboratory Comparison II: CO2 Isotherms Measured on Moisture-Equilibrated Argonne Premium Coals at 55oC and 15 MPa", International Journal of Coal Geology 72, 153-164.

  2. Publishing datasets with eSciDoc and panMetaDocs

    Science.gov (United States)

    Ulbricht, D.; Klump, J.; Bertelmann, R.

    2012-04-01

    Currently serveral research institutions worldwide undertake considerable efforts to have their scientific datasets published and to syndicate them to data portals as extensively described objects identified by a persistent identifier. This is done to foster the reuse of data, to make scientific work more transparent, and to create a citable entity that can be referenced unambigously in written publications. GFZ Potsdam established a publishing workflow for file based research datasets. Key software components are an eSciDoc infrastructure [1] and multiple instances of the data curation tool panMetaDocs [2]. The eSciDoc repository holds data objects and their associated metadata in container objects, called eSciDoc items. A key metadata element in this context is the publication status of the referenced data set. PanMetaDocs, which is based on PanMetaWorks [3], is a PHP based web application that allows to describe data with any XML-based metadata schema. The metadata fields can be filled with static or dynamic content to reduce the number of fields that require manual entries to a minimum and make use of contextual information in a project setting. Access rights can be applied to set visibility of datasets to other project members and allow collaboration on and notifying about datasets (RSS) and interaction with the internal messaging system, that was inherited from panMetaWorks. When a dataset is to be published, panMetaDocs allows to change the publication status of the eSciDoc item from status "private" to "submitted" and prepare the dataset for verification by an external reviewer. After quality checks, the item publication status can be changed to "published". This makes the data and metadata available through the internet worldwide. PanMetaDocs is developed as an eSciDoc application. It is an easy to use graphical user interface to eSciDoc items, their data and metadata. It is also an application supporting a DOI publication agent during the process of

  3. 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

  4. Use of cyclic voltammetry and electrochemical impedance spectroscopy for determination of active surface area of modified carbon-based electrodes

    International Nuclear Information System (INIS)

    Souza, Leticia Lopes de

    2011-01-01

    Carbon-based electrodes as well the ion exchange electrodes among others have been applied mainly in the treatment of industrial effluents and radioactive wastes. Carbon is also used in fuel cells as substrate for the electrocatalysts, having high surface area which surpasses its geometric area. The knowledge of the total active area is important for the determination of operating conditions of an electrochemical cell with respect to the currents to be applied (current density). In this study it was used two techniques to determine the electrochemical active surface area of glassy carbon, electrodes and ion exchange electrodes: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experiments were carried out with KNO 3 0.1 mol.L -1 solutions in a three-electrode electrochemical cell: carbon-based working electrode, platinum auxiliary electrode and Ag/AgCl reference electrode. The glassy carbon and porous carbon electrodes with geometric areas of 3.14 x 10 -2 and 2.83 X 10 -1 cm 2 , respectively, were used. The ion exchange electrode was prepared by mixing graphite, carbon, ion exchange resin and a binder, and this mixture was applied in three layers on carbon felt, using a geometric area of 1.0 cm 2 during the experiments. The capacitance (Cd) of the materials was determined by EIS using Bode diagrams. The value of 172 μF.cm -2 found for the glassy carbon is consistent with the literature data (∼ 200 μF.cm'- 2 ). By VC, varying the scan rate from 0.2 to 2.0 mV.s-1, the capacitance CdS (S = active surface area) in the region of the electric double layer (EDL) of each material was determined. By EIS, the values of C d , 3.0 x 10 -5 μF.cm'- 2 and 11 x 10 3 μF.cm-2, were found for the porous carbon and ion exchange electrodes, respectively, which allowed the determination of active surface areas as 3.73 x 106 cm 2 and 4.72 cm 2 . To sum up, the combined use of EIS and CV techniques is a valuable tool for the calculation of active surface

  5. FLUORIDE SORPTION USING MORRINGA INDICA-BASED ACTIVATED CARBON

    Directory of Open Access Journals (Sweden)

    G. Karthikeyan, S. Siva Ilango

    2007-01-01

    Full Text Available Batch adsorption experiments using activated carbon prepared from Morringa Indica bark were conducted to remove fluoride from aqueous solution. A minimum contact time of 25 min was required for optimum fluoride removal. The influence of adsorbent, dose, pH, co-ions (cations and anions on fluoride removal by the activated carbon has been experimentally verified. The adsorption of fluoride was studied at 30 C, 40 C and 50 C. The kinetics of adsorption and adsorption isotherms at different temperatures were studied. The fluoride adsorption obeyed both Langmuir and Freundlich isotherms and followed a pseudo first order kinetic model. The thermodynamic studies revealed that the fluoride adsorption by Morringa Indica is an endothermic process indicating an increase in sorption rate at higher temperatures. The negative values of G indicate the spontaneity of adsorption. SEM and XRD studies confirmed the surface morphological characteristics of the adsorbent and the deposition of fluoride on the surface of the material.

  6. 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

  7. Inter- and Intraspecific Variations in the Pectoral Muscles of Common Chimpanzees (Pan troglodytes), Bonobos (Pan paniscus), and Humans (Homo sapiens).

    Science.gov (United States)

    Potau, J M; Arias-Martorell, J; Bello-Hellegouarch, G; Casado, A; Pastor, J F; de Paz, F; Diogo, R

    2018-01-01

    We have analyzed anatomic variations in the pectoralis major and pectoralis minor muscles of common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) and compared them to anatomic variations in these muscles in humans (Homo sapiens) . We have macroscopically dissected these muscles in six adult Pan troglodytes , five Pan paniscus of ages ranging from fetus to adult, and five adult Homo sapiens . Although Pan troglodytes are thought to lack a separate pectoralis abdominis muscle, we have identified this muscle in three of the Pan troglodytes ; none of the Pan paniscus , however, had this muscle. We have also found deep supernumerary fascicles in the pectoralis major of two Pan troglodytes and all five Pan paniscus . In all six Pan troglodytes , the pectoralis minor was inserted at the supraspinatus tendon, while, in Pan paniscus and Homo sapiens , it was inserted at the coracoid process of the scapula. Some of the anatomic features and variations of these muscles in common chimpanzees and bonobos are similar to those found in humans, therefore enhancing our knowledge of primate comparative anatomy and evolution and also shedding light on several clinical issues.

  8. Inter- and Intraspecific Variations in the Pectoral Muscles of Common Chimpanzees (Pan troglodytes, Bonobos (Pan paniscus, and Humans (Homo sapiens

    Directory of Open Access Journals (Sweden)

    J. M. Potau

    2018-01-01

    Full Text Available We have analyzed anatomic variations in the pectoralis major and pectoralis minor muscles of common chimpanzees (Pan troglodytes and bonobos (Pan paniscus and compared them to anatomic variations in these muscles in humans (Homo sapiens. We have macroscopically dissected these muscles in six adult Pan troglodytes, five Pan paniscus of ages ranging from fetus to adult, and five adult Homo sapiens. Although Pan troglodytes are thought to lack a separate pectoralis abdominis muscle, we have identified this muscle in three of the Pan troglodytes; none of the Pan paniscus, however, had this muscle. We have also found deep supernumerary fascicles in the pectoralis major of two Pan troglodytes and all five Pan paniscus. In all six Pan troglodytes, the pectoralis minor was inserted at the supraspinatus tendon, while, in Pan paniscus and Homo sapiens, it was inserted at the coracoid process of the scapula. Some of the anatomic features and variations of these muscles in common chimpanzees and bonobos are similar to those found in humans, therefore enhancing our knowledge of primate comparative anatomy and evolution and also shedding light on several clinical issues.

  9. 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.

  10. Equilibrium and kinetic study for the adsorption of p-nitrophenol from wastewater using olive cake based activated carbon

    International Nuclear Information System (INIS)

    Abdel-Ghani, N. T.; Rawash, E. S. A.; El-Chaghaby, G. A.

    2016-01-01

    The present work was carried out to evaluate the removal of p-nitrophenol by adsorption onto olive cake based activated carbon having a BET surface area of 672 m²/g. The batch adsorption experimental results indicated that the equilibrium time for nitrophenol adsorption by olive cake-based activated carbon was 120 minutes. The adsorption data was modeled by equilibrium and kinetic models. The pseudo- first and second order as well as the Elovichkinetic models were applied to fit the experimental data and the intra particle diffusion model was assessed for describing the mechanism of adsorption. The data were found to be best fitted to the pseudo-second order model with a correlation coefficient (R2=0.986). The intra particle diffusion mechanism also showed a good fit to the experimental data, showing two distinct linear parts assuming that more than one step could be involved in the adsorption of nitrophenol by the activated carbon. The equilibrium study was performed using three models including Langmuir, Freundlich and Temkin. The results revealed that the Temkin equilibrium model is the best model fitting the experimental data (R2=0.944). The results of the present study proved the efficiency of using olive cake based activated carbon as a novel adsorbent for the removal of nitrophenol from aqueous solution.

  11. Activated carbons employed to remove ionic liquids from aqueous solutions

    International Nuclear Information System (INIS)

    Hassan, S.; Farooq, A.; Ahmad, M.A.; Irfan, N.; Tufail, M.

    2011-01-01

    Imidazolium and pyridinium based ionic liquids (ILs) have been separated from aqueous solutions by adsorption using a raw Chinese activated carbon (CAC), a bleached Chinese activated carbon (BAC) and an acid treated Chinese activated carbon (AAC) as adsorbent. Adsorption isotherms data of ionic liquids on activated carbons has been obtained. The influence of both cations and anions was analyzed by studying three different ILs. The role of surface chemistry of the adsorbent was also examined using activated carbons modified by oxidative treatments. The BET surface area of activated carbons was measured by nitrogen adsorption. The results of this work indicate that activated carbon is an attractive adsorbent to remove ionic liquids from water streams. It has also been demonstrated that the adsorption of hydrophilic ionic liquids can be improved by modifying the amount and nature of oxygen groups on the activated carbon surface specially by increasing basic groups. The adsorption data for isotherms was studied at acidic, neutral and basic pH values. (author)

  12. Highly Crumpled All-Carbon Transistors for Brain Activity Recording.

    Science.gov (United States)

    Yang, Long; Zhao, Yan; Xu, Wenjing; Shi, Enzheng; Wei, Wenjing; Li, Xinming; Cao, Anyuan; Cao, Yanping; Fang, Ying

    2017-01-11

    Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.

  13. The influence of activating agents on the performance of rice husk-based carbon for sodium lauryl sulfate and chrome (Cr) metal adsorptions

    Science.gov (United States)

    Arneli; Safitri, Z. F.; Pangestika, A. W.; Fauziah, F.; Wahyuningrum, V. N.; Astuti, Y.

    2017-02-01

    This research aims to study the influence of activating agents to produce rice husk based-carbon with high adsorption capacity and efficiency for either hazardous organic molecules or heavy metals which are unfriendly for the environment. Firstly, rice husk was burned by pyrolysis at different temperatures to produce rice husk-based carbon. To improve its ability as an adsorbent, carbon was treated with activating agents, namely, H3PO4 and KOH at room and high temperature (420 °C). The performance of carbon was then tested by contacting it with surfactant (SLS). Finally, the surfactant-modified active carbon was applied for chrome metal removal. The result shows that activation of carbon using phosphate acid (H3PO4) was more effective than potassium hydroxide (KOH) conducted at high temperature to adsorb sodium lauryl sulfate (SLS) and chrome metal with the adsorption capacity 1.50 mgg-1 and 0.375 mgg-1, respectively.

  14. Characterization and organic electric-double-layer-capacitor application of KOH activated coal-tar-pitch-based carbons: Effect of carbonization temperature

    Science.gov (United States)

    Choi, Poo Reum; Lee, Eunji; Kwon, Soon Hyung; Jung, Ji Chul; Kim, Myung-Soo

    2015-12-01

    The present study reports the influence of pre-carbonization on the properties of KOH-activated coal tar pitch (CTP). The change of crystallinity and pore structure of pre-carbonized CTPs as well as their activated carbons (ACs) as function of pre-carbonization temperature are investigated. The crystallinity of pre-carbonized CTPs increases with increasing the carbonization temperature up to 600 °C, but a disorder occurs during the carbonization around 700 °C and an order happens gradually with increasing the carbonization temperatures in range of 800-1000 °C. The CTPs pre-carbonized at high temperatures are more difficult to be activated with KOH than those pre-carbonized at low temperatures due to the increase of micro-crystalline size and the decrease of surface functional groups. The micro-pores and meso-pores are well developed at around 1.0 nm and 2.4 nm, respectively, as the ACs are pre-carbonized at temperatures of 500-600 °C, exhibiting high specific capacitances as electrode materials for electric double layer capacitor (EDLC). Although the specific surface area (SSA) and pore volume of ACs pre-carbonized at temperatures of 900-1000 °C are extraordinary low (non-porous) as compared to those of AC pre-carbonized at 600 °C, their specific capacitances are comparable to each other. The large specific capacitances with low SSA ACs can be attributed to the structural change resulting from the electrochemical activation during the 1st charge above 2.0 V.

  15. How Well Does Carbon Handle Stress? - A Brief Overview of Carbons in Structural Applications

    Science.gov (United States)

    2004-06-09

    strong-- PAN fibers… or weak-- aerogel be stiff—pitch carbon fibers...or flexible--Grafoil 4 A2705V2004. Approved for public release; distribution...distribution unlimited Carbon Fiber Reinforcement Aeronautics • Carbon-epoxy and carbon-phenolic are used in military aircraft . 39 A2705V2004. Approved...performance aircraft Gossamer Albatross Gossamer Penguin Voyager 40 A2705V2004. Approved for public release; distribution unlimited Carbon Fiber

  16. Preparation of Ag/HBP/PAN Nanofiber Web and Its Antimicrobial and Filtration Property

    Directory of Open Access Journals (Sweden)

    Li-Rong Yao

    2016-01-01

    Full Text Available To widen the application of nanofibers web in the field of medical health materials, a new Ag/amino-terminated hyperbranched polymer (HBP/polyacrylonitrile (PAN nanofiber web with excellent antimicrobial activity and filtration property was produced with Ag/HBP dispersion solution and PAN nanofiber. Ag/HBP dispersion solution was prepared with HBP as reducer and stabilizer, and Ag/HBP/PAN nanofiber was prepared by modifying electrospun PAN nanofiber with Ag/HBP aqueous solution. The characterization results showed that spherical Ag nanoparticles were prepared and they had a narrow distribution in HBP aqueous solution. The results of Ag/HBP/PAN nanofiber characterized with SEM and EDS showed that the content of silver nanoparticles on the surface of PAN nanofiber was on the increase when the treating temperature rose. The bacterial reduction rates of HBP-treated PAN nanofiber against S. aureus and E. coli were about 89%, while those of the Ag/HBP/PAN nanofiber against S. aureus and E. coli were 99.9% and 99.96%, respectively, due to the cooperative effects from the amino groups in HBP and Ag nanoparticles. Moreover, the small pores and high porosity in Ag/HBP/PAN nanofiber web resulted in high filtration efficiency (99.9% for removing smaller particles (0.1 μm~0.7 μm, which was much higher than that of the gauze mask.

  17. Satellite Based Cropland Carbon Monitoring System

    Science.gov (United States)

    Bandaru, V.; Jones, C. D.; Sedano, F.; Sahajpal, R.; Jin, H.; Skakun, S.; Pnvr, K.; Kommareddy, A.; Reddy, A.; Hurtt, G. C.; Izaurralde, R. C.

    2017-12-01

    Agricultural croplands act as both sources and sinks of atmospheric carbon dioxide (CO2); absorbing CO2 through photosynthesis, releasing CO2 through autotrophic and heterotrophic respiration, and sequestering CO2 in vegetation and soils. Part of the carbon captured in vegetation can be transported and utilized elsewhere through the activities of food, fiber, and energy production. As well, a portion of carbon in soils can be exported somewhere else by wind, water, and tillage erosion. Thus, it is important to quantify how land use and land management practices affect the net carbon balance of croplands. To monitor the impacts of various agricultural activities on carbon balance and to develop management strategies to make croplands to behave as net carbon sinks, it is of paramount importance to develop consistent and high resolution cropland carbon flux estimates. Croplands are typically characterized by fine scale heterogeneity; therefore, for accurate carbon flux estimates, it is necessary to account for the contribution of each crop type and their spatial distribution. As part of NASA CMS funded project, a satellite based Cropland Carbon Monitoring System (CCMS) was developed to estimate spatially resolved crop specific carbon fluxes over large regions. This modeling framework uses remote sensing version of Environmental Policy Integrated Climate Model and satellite derived crop parameters (e.g. leaf area index (LAI)) to determine vertical and lateral carbon fluxes. The crop type LAI product was developed based on the inversion of PRO-SAIL radiative transfer model and downscaled MODIS reflectance. The crop emergence and harvesting dates were estimated based on MODIS NDVI and crop growing degree days. To evaluate the performance of CCMS framework, it was implemented over croplands of Nebraska, and estimated carbon fluxes for major crops (i.e. corn, soybean, winter wheat, grain sorghum, alfalfa) grown in 2015. Key findings of the CCMS framework will be presented

  18. Precision Photometry and Astrometry from Pan-STARRS

    Science.gov (United States)

    Magnier, Eugene A.; Pan-STARRS Team

    2018-01-01

    The Pan-STARRS 3pi Survey has been calibrated with excellent precision for both astrometry and photometry. The Pan-STARRS Data Release 1, opened to the public on 2016 Dec 16, provides photometry in 5 well-calibrated, well-defined bandpasses (grizy) astrometrically registered to the Gaia frame. Comparisons with other surveys illustrate the high quality of the calibration and provide tests of remaining systematic errors in both Pan-STARRS and those external surveys. With photometry and astrometry of roughly 3 billion astronomical objects, the Pan-STARRS DR1 has substantial overlap with Gaia, SDSS, 2MASS and other surveys. I will discuss the astrometric tie between Pan-STARRS DR1 and Gaia and show comparisons between Pan-STARRS and other large-scale surveys.

  19. The ATLAS PanDA Monitoring System and its Evolution

    CERN Document Server

    Klimentov, A; The ATLAS collaboration; Potekhin, M; Wenaus, T

    2011-01-01

    The PanDA (Production and Distributed Analysis) Workload Management System is used for ATLAS distributed production and analysis worldwide. The needs of ATLAS global computing imposed challenging requirements on PanDA design in areas such as scalability, robustness, automation, diagnostics, and usability for both production shifters and analysis users. Important to meeting these and other requirements is a comprehensive monitoring system. Through a system-wide job database, the PanDA monitor provides a comprehensive and coherent view of the system and job execution, from high level summaries to detailed drill-down job diagnostics. It is (like the rest of PanDA) an Apache-based Python application backed by Oracle. The presentation layer is HTML code generated on the fly in the Python application which is also responsible for managing database queries. However, this approach is lacking in user interface flexibility, simplicity of communication with external systems, and ease of maintenance. We decided to migrat...

  20. The ATLAS PanDA Monitoring System and its Evolution

    CERN Document Server

    Klimentov, A; The ATLAS collaboration; Potekhin, M; Wenaus, T

    2010-01-01

    The PanDA (Production and Distributed Analysis) Workload Management System is used for ATLAS distributed production and analysis worldwide. The needs of ATLAS global computing imposed challenging requirements on PanDA design in areas such as scalability, robustness, automation, diagnostics, and usability for both production shifters and analysis users. Important to meeting these and other requirements is a comprehensive monitoring system. Through a system-wide job database, the PanDA monitor provides a comprehensive and coherent view of the system and job execution, from high level summaries to detailed drill-down job diagnostics. It is (like the rest of PanDA) an Apache-based Python application backed by Oracle. The presentation layer is HTML code generated on the fly in the Python application which is also responsible for managing database queries. However, this approach is lacking in user interface flexibility, simplicity of communication with external systems, and ease of maintenance. We decided to migrat...

  1. Minimizing activated carbons production cost

    International Nuclear Information System (INIS)

    Stavropoulos, G.G.; Zabaniotou, A.A.

    2009-01-01

    A detailed economic evaluation of activated carbons production process from various raw materials is undertaken using the conventional economic indices (ROI, POT, and NPV). The fundamental factors that affect production cost were taken into account. It is concluded that for an attractive investment in activated carbons production one should select the raw material with the highest product yield, adopt a chemical activation production scheme and should base product price on product-surface area (or more generally on product adsorption capacity for the adsorbate in consideration). A raw material that well meets the above-mentioned criteria is petroleum coke but others are also promising (charcoals, and carbon black). Production cost then can be optimized by determining its minimum value of cost that results from the intercept between the curves of plant capacity and raw material cost - if any. Taking into account the complexity of such a techno-economic analysis, a useful suggestion could be to start the evaluations from a plant capacity corresponding to the break-even point, i. e. the capacity at which income equals production cost. (author)

  2. Design, realization and testing of an adsorption refrigerator based on activated carbon/ethanol working pair

    International Nuclear Information System (INIS)

    Frazzica, A.; Palomba, V.; Dawoud, B.; Gullì, G.; Brancato, V.; Sapienza, A.; Vasta, S.; Freni, A.; Costa, F.; Restuccia, G.

    2016-01-01

    Highlights: • Development of a lab-scale adsorption refrigerator. • Optimization of working pair and adsorber configuration through experimental activity. • Experimental testing of the prototype under real working boundary conditions. - Abstract: In the present paper design, realization and testing of a novel small scale adsorption refrigerator prototype based on activated carbon/ethanol working pair is described. Firstly, experimental activity has been carried out for identification of the best performing activated carbon available on the market, through the evaluation of the achievable thermodynamic performance both under air conditioning and refrigeration conditions. Once identified the best performing activated carbon, the design of the adsorber was developed by experimental dynamic performance analysis, carried out by means of the Gravimetric-Large Temperature Jump (G-LTJ) apparatus available at CNR ITAE lab. Finally, the whole 0.5 kW refrigerator prototype was designed and built. First experimental results both under reference air conditioning and refrigeration cycles have been reported, to check the achievable performance. High Specific Cooling Powers (SCPs), 95 W/kg and 50 W/kg, for air conditioning and refrigeration respectively, were obtained, while the COP ranged between 0.09 and 0.11, thus showing an improvement of the current state of the art.

  3. Pan-tropical monitoring of deforestation

    International Nuclear Information System (INIS)

    Achard, F; DeFries, R; Eva, H; Hansen, M; Mayaux, P; Stibig, H-J

    2007-01-01

    This paper reviews the technical capabilities for monitoring deforestation from a pan-tropical perspective in response to the United Nations Framework Convention on Climate Change (UNFCCC) process, which is studying the technical issues surrounding the ability to reduce greenhouse gas emissions from deforestation in developing countries. The successful implementation of such policies requires effective forest monitoring systems that are reproducible, provide consistent results, meet standards for mapping accuracy, and can be implemented from national to pan-tropical levels. Remotely sensed data, supported by ground observations, are crucial to such efforts. Recent developments in global to regional monitoring of forests can contribute to reducing the uncertainties in estimates of emissions from deforestation. Monitoring systems at national levels in developing countries can also benefit from pan-tropical and regional observations, mainly by identifying hot spots of change and prioritizing areas for monitoring at finer spatial scales. A pan-tropical perspective is also required to ensure consistency between different national monitoring systems. Data sources already exist to determine baseline periods in the 1990s as historical reference points. Key requirements for implementing such monitoring programs, both at pan-tropical and at national scales, are international commitment of resources to increase capacity, coordination of observations to ensure pan-tropical coverage, access to free or low-cost data, and standardized, consensus protocols for data interpretation and analysis

  4. Isotopic composition of atmospheric moisture from pan water evaporation measurements.

    Science.gov (United States)

    Devi, Pooja; Jain, Ashok Kumar; Rao, M Someshwer; Kumar, Bhishm

    2015-01-01

    A continuous and reliable time series data of the stable isotopic composition of atmospheric moisture is an important requirement for the wider applicability of isotope mass balance methods in atmospheric and water balance studies. This requires routine sampling of atmospheric moisture by an appropriate technique and analysis of moisture for its isotopic composition. We have, therefore, used a much simpler method based on an isotope mass balance approach to derive the isotopic composition of atmospheric moisture using a class-A drying evaporation pan. We have carried out the study by collecting water samples from a class-A drying evaporation pan and also by collecting atmospheric moisture using the cryogenic trap method at the National Institute of Hydrology, Roorkee, India, during a pre-monsoon period. We compared the isotopic composition of atmospheric moisture obtained by using the class-A drying evaporation pan method with the cryogenic trap method. The results obtained from the evaporation pan water compare well with the cryogenic based method. Thus, the study establishes a cost-effective means of maintaining time series data of the isotopic composition of atmospheric moisture at meteorological observatories. The conclusions drawn in the present study are based on experiments conducted at Roorkee, India, and may be examined at other regions for its general applicability.

  5. Present and past microbial life in continental salt pan sediments in Southern Africa

    Science.gov (United States)

    Genderjahn, Steffi; Mangelsdorf, Kai; Alawi, Mashal; Kallmeyer, Jens; Wagner, Dirk

    2015-04-01

    The southwestern African region is characterized by strong climate variability. To get a better understanding on the climate evolution and environmental condition in Namibia and South Africa, terrestrial climate archives are investigated. Since there are almost no lakes, continental salt pans represent the only terrestrial geoarchives with the potential to preserve climate signals during sediment deposition. Climate has a strong impact on the salt pan ecosystem, causing adaptation of salt pan microorganisms to varying temperature, precipitation and salinity conditions. To reconstruct climate variability during the Holocene, the composition, diversity and abundance of indigenous microbial communities with depth and related to different soil parameters are investigated. We are using a combined approach of microbiological and lipid biomarker analyses to demonstrate the response of the microbial communities due to environmental changes. For microbiological analyses outcrops were conducted or short cores (0-100 cm) were drilled at four different salt pans in Aminuis, Koes and Witpan region having rather different geochemical properties. The current work focused on changes within the microbial communities due to the impact of long-term climate variation and the associated environmental changes and is part of the project 'Signals of climate and landscape change preserved in southern African GeoArchives' in the scope of the SPACES program, which is funded by the German Federal Ministry of Education and Research (BMBF). For a quantitative characterization of microbial communities molecular techniques such as polymerase chain reaction (PCR) and real-time quantitative PCR (qPCR) based on the 16S rRNA genes are used. Moreover, 454 sequencing technique is utilized to describe the diversity and abundance of microorganisms in detail. Soil parameters are described by standard soil scientific methods. Furthermore, microbial lipid biomarker analyses were done to characterize living

  6. Estrategias mundiales en la reducción de sal/sodio en el pan

    OpenAIRE

    Mónica Valverde Guillén; Jennifer Picado Pérez

    2013-01-01

    Objetivo: Proporcionar información sobre las acciones mundiales en la reducción de sal/sodio en el pan para generar datos útiles en la implementación de estrategias que busquen la disminución del consumo de sal/sodio a partir de productos panificados. Método: Se realizó una búsqueda de información en las bases de datos de Binass, PubMed, Scielo e instituciones gubernamentales. Las palabras claves fueron: contenido de sodio en el pan, menos sodio en pan, acciones para reducir sal en el pan, co...

  7. Surface structural evolvement in the conversion of polyacrylonitrile precursors to carbon fibers

    International Nuclear Information System (INIS)

    Qian, Xin; Zou, Ruifen; OuYang, Qin; Wang, Xuefei; Zhang, Yonggang

    2015-01-01

    Highlights: • The characteristic striated topography of PAN precursors resulted from the wet spinning process could pass down to carbon fibers. • The ridges and grooves monitored became much more well-defined after the thermo-oxidation. • Both the depth and the width of longitudinal grooves decreased after the carbonization. • Carbon, nitrogen, oxygen and silicon were the governing elements on the fiber surface. - Abstract: Surface structural evolvement in the conversion of polyacrylonitrile (PAN) precursors to carbon fibers was investigated through scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). SEM results showed that the characteristic striated topography of PAN precursors resulted from the wet spinning process could pass down to carbon fibers. The fiber diameter gradually decreased from 11.3 μm to 5.5 μm and the corresponding density increased from 1.18 g/cm 3 to 1.80 g/cm 3 in the conversion of PAN precursors to carbon fibers. The ridges and grooves monitored by AFM became much more well-defined after the thermo-oxidation. However, the original longitudinal grooves were destroyed and both the depth and the width of longitudinal grooves decreased after the carbonization. XPS results revealed that carbon, nitrogen, oxygen and silicon were the governing elements on the fiber surface. The −C−C functional groups was the dominant groups and the relative contents of −C=O and −COO groups gradually increased in the process of thermo-oxidation and carbonization

  8. Functionalized polymer-based spherical activated carbon for liquid and gas phase applications

    International Nuclear Information System (INIS)

    Schrage, Christian; Modrow, Antje; Fichtner, Sven; Giebelhausen, Jann Michael; Boehringer, Bertram

    2014-01-01

    Polymer-based spherical activated carbon (PBSAC) can be functionalized through the integration of reactive compounds. This offers new fields of applications for this adsorbent material. Impregnated PBSAC can be used as broadband sorbent material for respiratory protection, and for removal of certain metals from water, while the integration of nitrogen leads to a material suitable for the clean-up of gases. Functionalization through oxidation or integration of nitrogen atoms enables the concentration of valuable resources like uranium or gold.

  9. The ATLAS PanDA Pilot in Operation

    International Nuclear Information System (INIS)

    Nilsson, P; De, K; Stradling, A; Caballero, J; Maeno, T; Wenaus, T

    2011-01-01

    The Production and Distributed Analysis system (PanDA) was designed to meet ATLAS requirements for a data-driven workload management system capable of operating at LHC data processing scale. Submitted jobs are executed on worker nodes by pilot jobs sent to the grid sites by pilot factories. This paper provides an overview of the PanDA pilot system and presents major features added in light of recent operational experience, including multi-job processing, advanced job recovery for jobs with output storage failures, gLExec based identity switching from the generic pilot to the actual user, and other security measures. The PanDA system serves all ATLAS distributed processing and is the primary system for distributed analysis; it is currently used at over 100 sites worldwide. We analyze the performance of the pilot system in processing real LHC data on the OSG, EGI and Nordugrid infrastructures used by ATLAS, and describe plans for its evolution.

  10. Effect of impregnation pressure and time on the porosity, structure and properties of polyacrylonitrile-fiber based carbon composites

    Energy Technology Data Exchange (ETDEWEB)

    Venugopalan, Ramani, E-mail: rvg@barc.gov.in [Powder Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Roy, Mainak, E-mail: mainak73@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Thomas, Susy [High Pressure Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Patra, A.K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sathiyamoorthy, D. [Powder Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2013-02-15

    Carbon–carbon composites may find applications in critical parts of advanced nuclear reactors. A series of carbon–carbon composites were prepared using polyacrylonitrile (PAN) based carbon fibers. The materials were densified by impregnating two-dimensional (2D) preforms with liquid phenol formaldehyde resin at different pressures and for different periods of time and then carbonizing those by slowly heating at 1000 °C. Effects of the processing parameters on the structure of the composites were extensively studied. The study showed conclusively that open porosity decreased with increasing impregnation pressure, whereas impregnation time had lesser effect. Matrix–resin bonding also improved at higher pressure. d{sub 002} spacing decreased and ordering along c-axis increased with concomitant increase in sp{sup 2}-carbon fraction at higher impregnation pressures. The fiber reinforced composites exhibited short range ordering of carbon atoms and satisfied structural conditions (d{sub 002} values) of amorphous carbon according to the turbostratic model for non-graphitic carbon materials. The composites had pellet-density of ∼85% of the theoretical value, low thermal expansion and negligible neutron-poisoning. They maintained structural integrity and retained disordered nature even on heat-treatment at ca. 1800 °C.

  11. Sorption Kinetics for the Removal of Cadmium and Zinc onto Palm Kernel Shell Based Activated Carbon

    Directory of Open Access Journals (Sweden)

    Muhammad Muhammad

    2010-12-01

    Full Text Available The kinetics and mechanism of cadmium and zinc adsorption on palm kernel shell based activated carbons (PKSAC have been studied. A series of batch laboratory studies were conducted in order to investigate the suitability of palm kernel shell based activated carbon (PKSAC for the removal of cadmium (cadmium ions and zinc (zinc ions from their aqueous solutions. All batch experiments were carried out at pH 7.0 and a constant temperature of 30+-1°C using an incubator shaker that operated at 150 rpm. The kinetics investigated includes the pseudo first order, the pseudo-second order and the intraparticle diffusion models. The pseudo-second order model correlate excellently the experimental data, suggesting that chemisorption processes could be the rate-limiting step. Keywords: adsorption, cadmium, kinetics, palm kernel shell, zinc

  12. Fluoride sorption using Cynodon dactylon based activated carbon

    Directory of Open Access Journals (Sweden)

    Alagumuthu G.

    2011-01-01

    Full Text Available This study deals the application of Cynodon dactylon based thermally activated carbon for fluoride toxicity. The batch adsorption techniques was followed at neutral pH as the functions of contact time, adsorbent dose, adsorbate concentration, temperature and the effect of co-anions. The data indicate that the prepared adsorbent surface sites are heterogeneous in nature and that fits into a heterogeneous site-binding model. The present system followed the Redlich-Peterson isotherm as well as Langmuir adsorption isotherm model. Lagergren pseudo-first-order, pseudo-second-order, intra particle diffusion and Elovich kinetics were modeled to describe the adsorption rate of fluoride and determined as this scheme followed pseudo-second-order kinetics. The calculated enthalpy change, ΔH°, and entropy change, ΔS°, for the adsorption process are +8.725 kJ/mol and +0.033 J/mol K respectively and shows endothermic experience. Instrumental analysis of XRD, FTIR and SEM gives the idea about the fluoride binding ability of adsorbent.

  13. Inter- and Intraspecific Variations in the Pectoral Muscles of Common Chimpanzees (Pan troglodytes), Bonobos (Pan paniscus), and Humans (Homo sapiens)

    OpenAIRE

    Potau, J. M.; Arias-Martorell, J.; Bello-Hellegouarch, G.; Casado, A.; Pastor, J. F.; de Paz, F.; Diogo, R.

    2018-01-01

    We have analyzed anatomic variations in the pectoralis major and pectoralis minor muscles of common chimpanzees (Pan\\ud troglodytes) and bonobos(Pan paniscus) and compared them to anatomic variations in these muscles in humans(Homo sapiens). We\\ud have macroscopically dissected these muscles in six adult Pan troglodytes, five Pan paniscus of ages ranging from fetus to adult, and\\ud five adult Homo sapiens. Although Pan troglodytes are thought to lack a separate pectoralis abdominis muscle, we...

  14. Catalytic reduction of hexaminecobalt(III) by pitch-based spherical activated carbon (PBSAC)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu; Mao, Yan-Peng; Zhu, Hai-Song; Cheng, Jing-Yi; Long, Xiang-Li; Yuan, Wei-Kang [State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai (China)

    2010-07-15

    The wet ammonia (NH{sub 3}) desulfurization process can be retrofitted to remove nitric oxide (NO) and sulfur dioxide (SO{sub 2}) simultaneously by adding soluble cobalt(II) salt into the aqueous ammonia solution. Activated carbon is used as a catalyst to regenerate hexaminecobalt(II), Co(NH{sub 3}){sub 6}{sup 2+}, so that NO removal efficiency can be maintained at a high level for a long time. In this study, the catalytic performance of pitch-based spherical activated carbon (PBSAC) in the simultaneous removal of NO and SO{sub 2} with this wet ammonia scrubbing process has been studied systematically. Experiments have been performed in a batch stirred cell to test the catalytic characteristics of PBSAC in the catalytic reduction of hexaminecobalt(III), Co(NH{sub 3}){sub 6}{sup 3+}. The experimental results show that PBSAC is a much better catalyst in the catalytic reduction of Co(NH{sub 3}){sub 6}{sup 3+} than palm shell activated carbon (PSAC). The Co(NH{sub 3}){sub 6}{sup 3+} reduction reaction rate increases with PBSAC when the PBSAC dose is below 7.5 g/L. The Co(NH{sub 3}){sub 6}{sup 3+} reduction rate increases with its initial concentration. Best Co(NH{sub 3}){sub 6}{sup 3+} conversion is gained at a pH range of 2.0-6.0. A high temperature is favorable to such reaction. The intrinsic activation energy of 51.00 kJ/mol for the Co(NH{sub 3}){sub 6}{sup 3+} reduction catalyzed by PBSAC has been obtained. The experiments manifest that the simultaneous elimination of NO and SO{sub 2} by the hexaminecobalt solution coupled with catalytic regeneration of hexaminecobalt(II) can maintain a NO removal efficiency of 90% for a long time. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  15. Brief review: Preparation techniques of biomass based activated carbon monolith electrode for supercapacitor applications

    Science.gov (United States)

    Taer, Erman; Taslim, Rika

    2018-02-01

    The synthesis of activated carbon monolith electrode made from a biomass material using the hydrolytic pressure or the pelletization technique of pre-carbonized materials is one of standard reported methods. Several steps such as pre-carbonization, milling, chemical activation, hydraulic press, carbonization, physical activation, polishing and washing need to be accomplished in the production of electrodes by this method. This is relatively a long process that need to be simplified. In this paper we present the standard method and proceed with the introduction to several alternative methods in the synthesis of activated carbon monolith electrodes. The alternative methods were emphasized on the selection of suitable biomass materials. All of carbon electrodes prepared by different methods will be analyzed for physical and electrochemical properties. The density, degree of crystallinity, surface morphology are examples for physical study and specific capacitance was an electrochemical properties that has been analysed. This alternative method has offered a specific capacitance in the range of 10 to 171 F/g.

  16. Pan-specific MHC class I predictors: A benchmark of HLA class I pan-specific prediction methods

    DEFF Research Database (Denmark)

    Zhang, Hao; Lundegaard, Claus; Nielsen, Morten

    2009-01-01

    not previously been compared using independent evaluation sets. Results: A diverse set of quantitative peptide binding affinity measurements was collected from IEDB, together with a large set of HLA class I ligands from the SYFPEITHI database. Based on these data sets, three different pan-specific HLA web...

  17. Protolytic carbon film technology

    Energy Technology Data Exchange (ETDEWEB)

    Renschler, C.L.; White, C.A.

    1996-04-01

    This paper presents a technique for the deposition of polyacrylonitrile (PAN) on virtually any surface allowing carbon film formation with only the caveat that the substrate must withstand carbonization temperatures of at least 600 degrees centigrade. The influence of processing conditions upon the structure and properties of the carbonized film is discussed. Electrical conductivity, microstructure, and morphology control are also described.

  18. Design of activated carbon/activated carbon asymmetric capacitors

    Science.gov (United States)

    Piñeiro-Prado, Isabel; Salinas-Torres, David; Ruiz Rosas, Ramiro; Morallon, Emilia; Cazorla-Amoros, Diego

    2016-03-01

    Supercapacitors are energy storage devices that offer a high power density and a low energy density in comparison with batteries. Their limited energy density can be overcome by using asymmetric configuration in mass electrodes, where each electrode works within their maximum available potential window, rendering the maximum voltage output of the system. Such asymmetric capacitors must be optimized through careful electrochemical characterization of the electrodes for accurate determination of the capacitance and the potential stability limits. The results of the characterization are then used for optimizing mass ratio of the electrodes from the balance of stored charge. The reliability of the design largely depends on the approach taken for the electrochemical characterization. Therefore, the performance could be lower than expected and even the system could break down, if a well thought out procedure is not followed. In this work, a procedure for the development of asymmetric supercapacitors based on activated carbons is detailed. Three activated carbon materials with different textural properties and surface chemistry have been systematically characterized in neutral aqueous electrolyte. The asymmetric configuration of the masses of both electrodes in the supercapacitor has allowed to cover a higher potential window, resulting in an increase of the energy density of the three devices studied when compared with the symmetric systems, and an improved cycle life.

  19. Design of activated carbon/activated carbon asymmetric capacitors

    Directory of Open Access Journals (Sweden)

    Isabel ePiñeiro-Prado

    2016-03-01

    Full Text Available Supercapacitors are energy storage devices that offer a high power density and a low energy density in comparison with batteries. Their limited energy density can be overcome by using asymmetric configuration in mass electrodes, where each electrode works within their maximum available potential window, rendering the maximum voltage output of the system. Such asymmetric capacitors must be optimized through careful electrochemical characterization of the electrodes for accurate determination of the capacitance and the potential stability limits. The results of the characterization are then used for optimizing mass ratio of the electrodes from the balance of stored charge. The reliability of the design largely depends on the approach taken for the electrochemical characterization. Therefore, the performance could be lower than expected and even the system could break down, if a well thought out procedure is not followed.In this work, a procedure for the development of asymmetric supercapacitors based on activated carbons is detailed. Three activated carbon materials with different textural properties and surface chemistry have been systematically characterized in neutral aqueous electrolyte. The asymmetric configuration of the masses of both electrodes in the supercapacitor has allowed to cover a higher potential window, resulting in an increase of the energy density of the three devices studied when compared with the symmetric systems, and an improved cycle life.

  20. COMPARATIVE EVALUATION OF COMMERCIAL AND SEWAGE SLUDGE BASED ACTIVATED CARBONS FOR THE REMOVAL OF TEXTILE DYES FROM AQUEOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    S. Sreedhar Reddy, B. Kotaiah

    2006-10-01

    Full Text Available The sorption of dyes from aqueous solutions on to sludge-based activated carbon have been studied and compared with commercial activated carbon. Adsorption parameters for the Langmuir and Freundlich isotherms were determined and the effects of effluent pH, adsorbent dosage, contact time and initial dye concentration were studied. A pseudo-second order kinetic model has been proposed to correlate the experimental data.

  1. The effects of O-MWNTs on the performances of PVA-CS-O-MWNTs/PAN pervaporation membrane

    Directory of Open Access Journals (Sweden)

    Yan Xi

    2017-08-01

    Full Text Available Oxidized multi-wall carbon nanotubes(O-MWNTs were used as inorganic nanofillers and added in the coating solution of polyvinyl alcohol (PVA-chitosan (CS mixtures,and the PVA-CS-O-MWNTs/PAN hollow fiber membranes were prepared by the dip-coating method for the pervaporation separation of methanol (MeOH/dimethyl carbonate (DMC mixture.The process conditions including the O-MWNTs amount,heat treatment temperature,and feed temperature were investigated in detail.The results indicate that the addition of O-MWNTs can enhance the permeation flux,hydrophilicity and mechanical properties of PVA-CS-O-MWNTs/PAN membranes.The preferable conditions are that O-MWNTs amount,heat treatment temperature,feed temperature,and the concentration of MeOH are 0.1%,80℃,40℃ and 70%,respectively.Thus,the permeation fluxand MeOHselectivity can attain 210 g·m-2·h-1and 7.82,respectively.

  2. The ATLAS PanDA Monitoring System and its Evolution

    Science.gov (United States)

    Klimentov, A.; Nevski, P.; Potekhin, M.; Wenaus, T.

    2011-12-01

    The PanDA (Production and Distributed Analysis) Workload Management System is used for ATLAS distributed production and analysis worldwide. The needs of ATLAS global computing imposed challenging requirements on the design of PanDA in areas such as scalability, robustness, automation, diagnostics, and usability for both production shifters and analysis users. Through a system-wide job database, the PanDA monitor provides a comprehensive and coherent view of the system and job execution, from high level summaries to detailed drill-down job diagnostics. It is (like the rest of PanDA) an Apache-based Python application backed by Oracle. The presentation layer is HTML code generated on the fly in the Python application which is also responsible for managing database queries. However, this approach is lacking in user interface flexibility, simplicity of communication with external systems, and ease of maintenance. A decision was therefore made to migrate the PanDA monitor server to Django Web Application Framework and apply JSON/AJAX technology in the browser front end. This allows us to greatly reduce the amount of application code, separate data preparation from presentation, leverage open source for tools such as authentication and authorization mechanisms, and provide a richer and more dynamic user experience. We describe our approach, design and initial experience with the migration process.

  3. The ATLAS PanDA Monitoring System and its Evolution

    International Nuclear Information System (INIS)

    Klimentov, A; Nevski, P; Wenaus, T; Potekhin, M

    2011-01-01

    The PanDA (Production and Distributed Analysis) Workload Management System is used for ATLAS distributed production and analysis worldwide. The needs of ATLAS global computing imposed challenging requirements on the design of PanDA in areas such as scalability, robustness, automation, diagnostics, and usability for both production shifters and analysis users. Through a system-wide job database, the PanDA monitor provides a comprehensive and coherent view of the system and job execution, from high level summaries to detailed drill-down job diagnostics. It is (like the rest of PanDA) an Apache-based Python application backed by Oracle. The presentation layer is HTML code generated on the fly in the Python application which is also responsible for managing database queries. However, this approach is lacking in user interface flexibility, simplicity of communication with external systems, and ease of maintenance. A decision was therefore made to migrate the PanDA monitor server to Django Web Application Framework and apply JSON/AJAX technology in the browser front end. This allows us to greatly reduce the amount of application code, separate data preparation from presentation, leverage open source for tools such as authentication and authorization mechanisms, and provide a richer and more dynamic user experience. We describe our approach, design and initial experience with the migration process.

  4. 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.

  5. 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

  6. Peter Pan-demien

    DEFF Research Database (Denmark)

    Holm, Claus

    2009-01-01

    Ungdommelig opførsel er moderne. I gamle dage skulle vi blive voksne. I dag skal selv gamle mænd og kvinder holde sig unge. Peter Pan-panikken er i os, og en af vores væsentligste sociale lidelser er umodenhed.......Ungdommelig opførsel er moderne. I gamle dage skulle vi blive voksne. I dag skal selv gamle mænd og kvinder holde sig unge. Peter Pan-panikken er i os, og en af vores væsentligste sociale lidelser er umodenhed....

  7. PanDA Pilot Submission using Condor-G: Experience and Improvements

    International Nuclear Information System (INIS)

    Zhao Xin; Hover, John; Wlodek, Tomasz; Wenaus, Torre; Frey, Jaime; Tannenbaum, Todd; Livny, Miron

    2011-01-01

    PanDA (Production and Distributed Analysis) is the workload management system of the ATLAS experiment, used to run managed production and user analysis jobs on the grid. As a late-binding, pilot-based system, the maintenance of a smooth and steady stream of pilot jobs to all grid sites is critical for PanDA operation. The ATLAS Computing Facility (ACF) at BNL, as the ATLAS Tier1 center in the US, operates the pilot submission systems for the US. This is done using the PanDA 'AutoPilot' scheduler component which submits pilot jobs via Condor-G, a grid job scheduling system developed at the University of Wisconsin-Madison. In this paper, we discuss the operation and performance of the Condor-G pilot submission at BNL, with emphasis on the challenges and issues encountered in the real grid production environment. With the close collaboration of Condor and PanDA teams, the scalability and stability of the overall system has been greatly improved over the last year. We review improvements made to Condor-G resulting from this collaboration, including isolation of site-based issues by running a separate Gridmanager for each remote site, introduction of the 'Nonessential' job attribute to allow Condor to optimize its behavior for the specific character of pilot jobs, better understanding and handling of the Gridmonitor process, as well as better scheduling in the PanDA pilot scheduler component. We will also cover the monitoring of the health of the system.

  8. A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide.

    Science.gov (United States)

    Anthonysamy, Shahreen Binti Izwan; Afandi, Syahidah Binti; Khavarian, Mehrnoush; Mohamed, Abdul Rahman Bin

    2018-01-01

    Various types of carbon-based and non-carbon-based catalyst supports for nitric oxide (NO) removal through selective catalytic reduction (SCR) with ammonia are examined in this review. A number of carbon-based materials, such as carbon nanotubes (CNTs), activated carbon (AC), and graphene (GR) and non-carbon-based materials, such as Zeolite Socony Mobil-5 (ZSM-5), TiO 2 , and Al 2 O 3 supported materials, were identified as the most up-to-date and recently used catalysts for the removal of NO gas. The main focus of this review is the study of catalyst preparation methods, as this is highly correlated to the behaviour of NO removal. The general mechanisms involved in the system, the Langmuir-Hinshelwood or Eley-Riedeal mechanism, are also discussed. Characterisation analysis affecting the surface and chemical structure of the catalyst is also detailed in this work. Finally, a few major conclusions are drawn and future directions for work on the advancement of the SCR-NH 3 catalyst are suggested.

  9. Damage of plants due to peroxyacyl nitrates (PAN)

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, H.; Terakado, K.

    1974-02-01

    In Japan plant damages began to resemble those due to PAN about 1972. Exposure experiments with artifically synthesized PAN in an environment simulation room determined the concentration of PAN and its duration to examine the relationship between these data in the field and crop damage. Synthesized PAN created by irradiating a mixture of ethyl nitrate and oxygen with ultraviolet light gave results similar to those seen in fields. From the end of April to the end of November, damages to petunias seemingly due to PAN appeared 15 times. The symptoms differed with the variety of petunia. After 14 experiments in fields from September 20 to November 30 with a continuous determination of the environmental concentration of PAN, damages to petunia were confirmed on 6 days when the maximum PAN concentration range was 3.0-6.7 ppb. The duration of concentrations higher than 3 ppb was 2-13 hr. The most serious damage appeared on September 20 when a concentration of more than 5 ppb continued for 7 hours. No damage appeared with a long continuation (6-12 hr) of a lower concentration of PAN of 2 ppb. Inter-varietal grafting showed that the symptoms and the degree of damage due to PAN were influenced only by the physiological specificity of the aerial portion of the plant. Leaves which are most affected by PAN differed with the variety of petunia.

  10. Optimizing Neighbor Discovery for Ad hoc Networks based on the Bluetooth PAN Profile

    DEFF Research Database (Denmark)

    Kuijpers, Gerben; Nielsen, Thomas Toftegaard; Prasad, Ramjee

    2002-01-01

    IP layer neighbor discovery mechanisms rely highly on broadcast/multicast capabilities of the underlying link layer. The Bluetooth personal area network (PAN) profile has no native link layer broadcast/multicast capabilities and can only emulate this by repeatedly unicast link layer frames....... This paper introduces a neighbor discovery mechanism that utilizes the resources in the Bluetooth PAN profile more efficient. The performance of the new mechanism is investigated using a IPv6 network simulator and compared with emulated broadcasting. It is shown that the signaling overhead can...

  11. A spatial neural fuzzy network for estimating pan evaporation at ungauged sites

    Directory of Open Access Journals (Sweden)

    C.-H. Chung

    2012-01-01

    Full Text Available Evaporation is an essential reference to the management of water resources. In this study, a hybrid model that integrates a spatial neural fuzzy network with the kringing method is developed to estimate pan evaporation at ungauged sites. The adaptive network-based fuzzy inference system (ANFIS can extract the nonlinear relationship of observations, while kriging is an excellent geostatistical interpolator. Three-year daily data collected from nineteen meteorological stations covering the whole of Taiwan are used to train and test the constructed model. The pan evaporation (Epan at ungauged sites can be obtained through summing up the outputs of the spatially weighted ANFIS and the residuals adjusted by kriging. Results indicate that the proposed AK model (hybriding ANFIS and kriging can effectively improve the accuracy of Epan estimation as compared with that of empirical formula. This hybrid model demonstrates its reliability in estimating the spatial distribution of Epan and consequently provides precise Epan estimation by taking geographical features into consideration.

  12. A synthesis of light absorption properties of the Pan-Arctic Ocean: application to semi-analytical estimates of dissolved organic carbon concentrations from space

    Science.gov (United States)

    Matsuoka, A.; Babin, M.; Doxaran, D.; Hooker, S. B.; Mitchell, B. G.; Bélanger, S.; Bricaud, A.

    2013-11-01

    The light absorption coefficients of particulate and dissolved materials are the main factors determining the light propagation of the visible part of the spectrum and are, thus, important for developing ocean color algorithms. While these absorption properties have recently been documented by a few studies for the Arctic Ocean (e.g., Matsuoka et al., 2007, 2011; Ben Mustapha et al., 2012), the datasets used in the literature were sparse and individually insufficient to draw a general view of the basin-wide spatial and temporal variations in absorption. To achieve such a task, we built a large absorption database at the pan-Arctic scale by pooling the majority of published datasets and merging new datasets. Our results showed that the total non-water absorption coefficients measured in the Eastern Arctic Ocean (EAO; Siberian side) are significantly higher than in the Western Arctic Ocean (WAO; North American side). This higher absorption is explained by higher concentration of colored dissolved organic matter (CDOM) in watersheds on the Siberian side, which contains a large amount of dissolved organic carbon (DOC) compared to waters off North America. In contrast, the relationship between the phytoplankton absorption (aφ(λ)) and chlorophyll a (chl a) concentration in the EAO was not significantly different from that in the WAO. Because our semi-analytical CDOM absorption algorithm is based on chl a-specific aφ(λ) values (Matsuoka et al., 2013), this result indirectly suggests that CDOM absorption can be appropriately derived not only for the WAO but also for the EAO using ocean color data. Derived CDOM absorption values were reasonable compared to in situ measurements. By combining this algorithm with empirical DOC vs. CDOM relationships, a semi-analytical algorithm for estimating DOC concentrations for coastal waters at the Pan-Arctic scale is presented and applied to satellite ocean color data.

  13. Investigations of carbon nanotubes and polyacrylonitrile composites for flexible textronics

    Science.gov (United States)

    Sowiński, J.; Wróblewski, G.; Janczak, D.; Jakubowska, M.

    2017-08-01

    Thin composite layers based on polyacrylonitrile (PAN) and carbon nanotubes (CNT) were fabricated by means of spray coating with pneumatic atomization. Research was conducted to achieve transparent and flexible electrodes. Prepared suspensions in different proportions of functional phase provided good dispersion quality of CNTs and the stability. The carbon nanotubes were dispersed in dimethylformamide and then added to polyacrylonitrile solution. Suspension was sprayed onto Polyethylene terephthalate (PET) foil. After thermal treatment, samples were mechanically and electrically tested. Thanks to carbon nanomaterials used in prepared coatings, high electrical conductivity and mechanical resistance was observed. Use of a polyacrylonitrile guarantee the flexibility of electrodes and high potential in integration with polyacrylonitrile based fabrics.

  14. A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback: The PCN Incubation-Panarctic Thermal (PInc-PanTher) Scaling Approach

    Science.gov (United States)

    Koven, C. D.; Schuur, E.; Schaedel, C.; Bohn, T. J.; Burke, E.; Chen, G.; Chen, X.; Ciais, P.; Grosse, G.; Harden, J. W.; Hayes, D. J.; Hugelius, G.; Jafarov, E. E.; Krinner, G.; Kuhry, P.; Lawrence, D. M.; MacDougall, A.; Marchenko, S. S.; McGuire, A. D.; Natali, S.; Nicolsky, D.; Olefeldt, D.; Peng, S.; Romanovsky, V. E.; Schaefer, K. M.; Strauss, J.; Treat, C. C.; Turetsky, M. R.

    2015-12-01

    We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a 3-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100.

  15. The future of PanDA in ATLAS distributed computing

    Science.gov (United States)

    De, K.; Klimentov, A.; Maeno, T.; Nilsson, P.; Oleynik, D.; Panitkin, S.; Petrosyan, A.; Schovancova, J.; Vaniachine, A.; Wenaus, T.

    2015-12-01

    Experiments at the Large Hadron Collider (LHC) face unprecedented computing challenges. Heterogeneous resources are distributed worldwide at hundreds of sites, thousands of physicists analyse the data remotely, the volume of processed data is beyond the exabyte scale, while data processing requires more than a few billion hours of computing usage per year. The PanDA (Production and Distributed Analysis) system was developed to meet the scale and complexity of LHC distributed computing for the ATLAS experiment. In the process, the old batch job paradigm of locally managed computing in HEP was discarded in favour of a far more automated, flexible and scalable model. The success of PanDA in ATLAS is leading to widespread adoption and testing by other experiments. PanDA is the first exascale workload management system in HEP, already operating at more than a million computing jobs per day, and processing over an exabyte of data in 2013. There are many new challenges that PanDA will face in the near future, in addition to new challenges of scale, heterogeneity and increasing user base. PanDA will need to handle rapidly changing computing infrastructure, will require factorization of code for easier deployment, will need to incorporate additional information sources including network metrics in decision making, be able to control network circuits, handle dynamically sized workload processing, provide improved visualization, and face many other challenges. In this talk we will focus on the new features, planned or recently implemented, that are relevant to the next decade of distributed computing workload management using PanDA.

  16. Base Carbone. Documentation about the emission factors of the Base CarboneR database

    International Nuclear Information System (INIS)

    2014-01-01

    The Base Carbone R is a public database of emission factors as required for carrying out carbon accounting exercises. It is administered by ADEME, but its governance involves many stakeholders and it can be added to freely. The articulation and convergence of environmental regulations requires data homogenization. The Base Carbone R proposes to be this centralized data source. Today, it is the reference database for article 75 of the Grenelle II Act. It is also entirely consistent with article L1341-3 of the French Transport Code and the default values of the European emission quotas exchange system. The data of the Base Carbone R can be freely consulted by all. Furthermore, the originality of this tool is that it enables third parties to propose their own data (feature scheduled for February 2015). These data are then assessed for their quality and transparency, then validated or refused for incorporation in the Base Carbone R . Lastly, a forum (planned for February 2015) will enable users to ask questions about the data, or to contest the data. The administration of the Base Carbone R is handled by ADEME. However, its orientation and the data that it contains are validated by a governance committee incorporating various public and private stakeholders. Lastly, transparency is one of the keystones of the Base Carbone R . Documentation details the hypotheses underlying the construction of all the data in the base, and refers to the studies that have enabled their construction. This document brings together the different versions of the Base Carbone R documentation: the most recent version (v11.5) and the previous versions (v11.0) which is shared in 2 parts dealing with the general case and with the specific case of overseas territories

  17. Preparation of oil palm empty fruit bunch-based activated carbon for removal of 2,4,6-trichlorophenol: Optimization using response surface methodology

    International Nuclear Information System (INIS)

    Hameed, B.H.; Tan, I.A.W.; Ahmad, A.L.

    2009-01-01

    The effects of three preparation variables: CO 2 activation temperature, CO 2 activation time and KOH:char impregnation ratio (IR) on the 2,4,6-trichlorophenol (2,4,6-TCP) uptake and carbon yield of the activated carbon prepared from oil palm empty fruit bunch (EFB) were investigated. Based on the central composite design, two quadratic models were developed to correlate the three preparation variables to the two responses. The activated carbon preparation conditions were optimized using response surface methodology by maximizing both the 2,4,6-TCP uptake and activated carbon yield within the ranges studied. The optimum conditions for preparing activated carbon from EFB for adsorption of 2,4,6-TCP were found as follows: CO 2 activation temperature of 814 deg. C, CO 2 activation time of 1.9 h and IR of 2.8, which resulted in 168.89 mg/g of 2,4,6-TCP uptake and 17.96% of activated carbon yield. The experimental results obtained agreed satisfactorily with the model predictions. The activated carbon prepared under optimum conditions was mesoporous with BET surface area of 1141 m 2 /g, total pore volume of 0.6 cm 3 /g and average pore diameter of 2.5 nm. The surface morphology and functional groups of the activated carbon were respectively determined from the scanning electron microscopy and Fourier transform infrared analysis.

  18. Role of activated carbon on micropollutans degradation by different radiation processes

    Directory of Open Access Journals (Sweden)

    Inmaculada Velo Gala

    2015-04-01

    Full Text Available The objective of this study was to analyse the influence of the presence of activated carbon on radiation processes. The triiodinated contrast medium diatrizoate was chosen as the contaminant model. We selected four commercial activated carbons and sixteen gamma radiation-modified carbons derived from these. The different advanced oxidation/reduction processes that have been studied were improved through the addition of activated carbon in the UV light and gamma radiating processes. In the UV/activated carbon process, the synergic activity of the activated carbon is enhanced in the samples with higher percentages of surface oxygen, ester/anhydride groups and carbon atoms with sp2 hybridization. Band gap determination of activated carbons revealed that they behave as semiconductor materials and, therefore, as photoactive materials in the presence of UV radiation, given that all band gap values are <4 eV. We also observed that the gamma radiation treatment reduces the band gap values of the activated carbons and that, in a single series of commercial carbons, lower band gap values correspond to higher contaminant removal rate values. We observed that the activity of the reutilized activated carbons is similar to that of the original carbons. Based on these results, we proposed that the activated carbon acts as a photocatalyst, promoting electrons of the valence band to the conduction band and increasing the generation of HO• radicals in the medium. Similarly, there was a synergic effect made by the presence of activated carbon in gamma radiation system, which favours pollutant removal. This synergic effect is independent of the textural but not the chemical characteristics of the activated carbon, observing a higher synergic activity for carbons with a higher surface content of oxygen, specifically quinone groups. We highlight that the synergic effect of the activated carbon requires adsorbent–adsorbate electrostatic interaction and is absent

  19. Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde M.; van Riel, Sarah J.; Saghir, Zaigham

    2015-01-01

    Objectives: Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. Methods: From...... the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were...... used to evaluate risk discrimination. Results: AUCs of 0.826–0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer...

  20. Optimization of activated carbon from sewage sludge using response surface methodology

    International Nuclear Information System (INIS)

    Muhammad Salleh Abustan; Hamidi Abdul Aziz; Mohd Azmier Ahmad

    2010-01-01

    Wastewater sludge cake was used to prepare activated carbon using physical activation method. The effects of three preparation variables; the activation temperature, activation time and carbon dioxide gas flow rate on chemical oxygen demand (COD) and ammonia removal from leachate solutions were investigated. Based on the central composite design (CCD), two quadratic models were developed to correlate the preparation variables to the COD and ammonia removal. From the analysis of variance (ANOVA), the significant factors on each experimental design response were identified. The optimum activated carbon prepared from wastewater sludge cake was obtained by using activation temperature of 510 degree Celsius, activation time of 30 min and carbon dioxide flow rate of 500 ml/ min. The optimum activated carbon showed COD and ammonia removal of 26 and 13 %, respectively. (author)

  1. Panning artifacts in digital pathology images

    Science.gov (United States)

    Avanaki, Ali R. N.; Lanciault, Christian; Espig, Kathryn S.; Xthona, Albert; Kimpe, Tom R. L.

    2017-03-01

    In making a pathologic diagnosis, a pathologist uses cognitive processes: perception, attention, memory, and search (Pena and Andrade-Filho, 2009). Typically, this involves focus while panning from one region of a slide to another, using either a microscope in a traditional workflow or software program and display in a digital pathology workflow (DICOM Standard Committee, 2010). We theorize that during panning operation, the pathologist receives information important to diagnosis efficiency and/or correctness. As compared to an optical microscope, panning in a digital pathology image involves some visual artifacts due to the following: (i) the frame rate is finite; (ii) time varying visual signals are reconstructed using imperfect zero-order hold. Specifically, after pixel's digital drive is changed, it takes time for a pixel to emit the expected amount of light. Previous work suggests that 49% of navigation is conducted in low-power/overview with digital pathology (Molin et al., 2015), but the influence of display factors has not been measured. We conducted a reader study to establish a relationship between display frame rate, panel response time, and threshold panning speed (above which the artifacts become noticeable). Our results suggest visual tasks that involve tissue structure are more impacted by the simulated panning artifacts than those that only involve color (e.g., staining intensity estimation), and that the panning artifacts versus normalized panning speed has a peak behavior which is surprising and may change for a diagnostic task. This is work in progress and our final findings should be considered in designing future digital pathology systems.

  2. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    Energy Technology Data Exchange (ETDEWEB)

    David A. Green; Brian S. Turk; Raghubir P. Gupta; Alejandro Lopez-Ortiz; Douglas P. Harrison; Ya Liang

    2001-07-01

    Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but this could not be confirmed. In the presence of carbon dioxide and water vapor, both the initial reaction rate of sodium carbonate with carbon dioxide and water and the sorbent capacity decreased with increasing temperature, consistent with the results from the previous quarter. Increasing the carbon dioxide concentration at constant temperature and water vapor concentration produced a measurable increase in rate, as did increasing the water vapor concentration at constant carbon dioxide concentration and temperature. Runs conducted with a flatter TGA pan resulted in a higher initial reaction rate, presumably due to improved gas-solid contact, but after a short time, there was no significant difference in the rates measured with the different pans. Analyses of kinetic data suggest that the surface of the sodium carbonate particles may be much hotter than the bulk gas due to the highly exothermic reaction with carbon dioxide and water, and that the rate of heat removal from the particle may control the reaction rate. A material and energy balance was developed for a cyclic carbonation/calcination process which captures about 26 percent of the carbon dioxide present in flue gas available at 250 C.

  3. Heterogeneity of activated carbons in adsorption of aniline from aqueous solutions

    Science.gov (United States)

    Podkościelny, P.; László, K.

    2007-08-01

    The heterogeneity of activated carbons (ACs) prepared from different precursors is investigated on the basis of adsorption isotherms of aniline from dilute aqueous solutions at various pH values. The APET carbon prepared from polyethyleneterephthalate (PET), as well as, commercial ACP carbon prepared from peat were used. Besides, to investigate the influence of carbon surface chemistry, the adsorption was studied on modified carbons based on ACP carbon. Its various oxygen surface groups were changed by both nitric acid and thermal treatments. The Dubinin-Astakhov (DA) equation and Langmuir-Freundlich (LF) one have been used to model the phenomenon of aniline adsorption from aqueous solutions on heterogeneous carbon surfaces. Adsorption-energy distribution (AED) functions have been calculated by using an algorithm based on a regularization method. Analysis of these functions for activated carbons studied provides important comparative information about their surface heterogeneity.

  4. Activated Carbon, Carbon Nanofiber and Carbon Nanotube Supported Molybdenum Carbide Catalysts for the Hydrodeoxygenation of Guaiacol

    Directory of Open Access Journals (Sweden)

    Eduardo Santillan-Jimenez

    2015-03-01

    Full Text Available Molybdenum carbide was supported on three types of carbon support—activated carbon; multi-walled carbon nanotubes; and carbon nanofibers—using ammonium molybdate and molybdic acid as Mo precursors. The use of activated carbon as support afforded an X-ray amorphous Mo phase, whereas crystalline molybdenum carbide phases were obtained on carbon nanofibers and, in some cases, on carbon nanotubes. When the resulting catalysts were tested in the hydrodeoxygenation (HDO of guaiacol in dodecane, catechol and phenol were obtained as the main products, although in some instances significant amounts of cyclohexane were produced. The observation of catechol in all reaction mixtures suggests that guaiacol was converted into phenol via sequential demethylation and HDO, although the simultaneous occurrence of a direct demethoxylation pathway cannot be discounted. Catalysts based on carbon nanofibers generally afforded the highest yields of phenol; notably, the only crystalline phase detected in these samples was Mo2C or Mo2C-ζ, suggesting that crystalline Mo2C is particularly selective to phenol. At 350 °C, carbon nanofiber supported Mo2C afforded near quantitative guaiacol conversion, the selectivity to phenol approaching 50%. When guaiacol HDO was performed in the presence of acetic acid and furfural, guaiacol conversion decreased, although the selectivity to both catechol and phenol was increased.

  5. Adsorption of basic Red 46 using sea mango (Cerbera odollam) based activated carbon

    Science.gov (United States)

    Azmi, Nur Azira Iqlima; Zainudin, Nor Fauziah; Ali, Umi Fazara Md

    2015-05-01

    Sea mango or Cerbera Odollam is another source of carbonaceous material that can be found abundantly in Malaysia. In this research, it is used as a new agricultural source of activated carbon. Sea mango activated carbon was prepared by chemical activation using potassium hydroxide (KOH). The sea mango was soaked in KOH at impregnation ratio of 1:1 and followed by carbonization at temperature of 600°C for 1 hour. The sample was then characterized using Scanning Electron Microscope (SEM) for surface morphology, while Brunauer-Emmett-Teller (BET) was used to study the surface area. The result shown that sea mango activated carbon (SMAC) developed new pores on its surface and the BET surface area measured was 451.87 m2/g. The SMAC performance was then tested for the removal of Basic Red 46 in batch process. The removal of Basic Red 46 (50 mg/L, natural pH, 0.1 g SMAC) was more than 99% in 15 minutes where it reached equilibrium in 30 minutes.

  6. Adsorption of basic Red 46 using sea mango (Cerbera odollam) based activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Azmi, Nur Azira Iqlima; Zainudin, Nor Fauziah [School of Bioprocess Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis (Malaysia); Ali, Umi Fazara Md [School of Environmental Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis (Malaysia)

    2015-05-15

    Sea mango or Cerbera Odollam is another source of carbonaceous material that can be found abundantly in Malaysia. In this research, it is used as a new agricultural source of activated carbon. Sea mango activated carbon was prepared by chemical activation using potassium hydroxide (KOH). The sea mango was soaked in KOH at impregnation ratio of 1:1 and followed by carbonization at temperature of 600°C for 1 hour. The sample was then characterized using Scanning Electron Microscope (SEM) for surface morphology, while Brunauer-Emmett-Teller (BET) was used to study the surface area. The result shown that sea mango activated carbon (SMAC) developed new pores on its surface and the BET surface area measured was 451.87 m{sup 2}/g. The SMAC performance was then tested for the removal of Basic Red 46 in batch process. The removal of Basic Red 46 (50 mg/L, natural pH, 0.1 g SMAC) was more than 99% in 15 minutes where it reached equilibrium in 30 minutes.

  7. Production of activated carbon from cellulosic fibers for environment protection

    International Nuclear Information System (INIS)

    Le Coq, L.; Faur, C.; Le Cloirec, P.; Phan Ngoc, H.

    2005-01-01

    Activated carbon fibers (ACF) have received an increasing attention in recent years as an adsorbent for purifying polluted gaseous and aqueous streams. Their preparation, characterization and application have been reported in many studies [1], which show that the porosity of ACF is dependent on activation conditions, as temperature, time or gas. ACF provide adsorption rates 2 to 50 times higher than Granular Activated Carbon [2], because of their low diameter (∼10 m) providing a larger external surface area in contact with the fluid compared with that of granules. Furthermore, their potential for the removal of various pollutants from water was demonstrated towards micro-organics like phenols [3], pesticides or dyes [4]. Generally, fibrous activated carbons are produced from natural or synthetic precursors by carbonization at 600-1000 C followed by an activation step by CO 2 oe steam at higher temperature [2]. Another way to produce the fibrous activated carbons is chemical activation with H 3 PO 4 , HNO 3 , KOH...[5]. Different types of synthetic or natural fibers have been used as precursors of fibrous activated carbons since 1970: polyacrylonitrile (PAN), polyphenol, rayon, cellulose phosphate, pitch, etc. Each of them has its own applications and limitations. The synthetic fibers being generally expensive, it would be interesting to find out low-cost precursors from local material resources. This work is a part of a research exchange program between the Vietnamese National Center of Natural Sciences and Technology (Vietnam) and the Ecole des Mines de Nantes (Gepea, France), with the aim to find some economical solutions for water treatment. Fibrous activated carbons are produced from natural cellulose fibers, namely jute and coconut fibers, which are abundant in Vietnam as well as in other tropical countries, have a low ash content and a low cost in comparison with synthetic fibers. Two methods are compared to produce activated carbons: 1) a physical

  8. 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

  9. Comparison studies of surface cleaning methods for PAN-based carbon fibers with acetone, supercritical acetone and subcritical alkali aqueous solutions

    International Nuclear Information System (INIS)

    Meng Linghui; Fan Dapeng; Huang Yudong; Jiang Zaixing; Zhang Chunhua

    2012-01-01

    Highlights: ► Cleaning with supercritical acetone is appropriate to wipe off the oxygenated contaminants. ► Cleaning with supercritical acetone causes smaller damage to bulk strength of carbon fibers. ► Cleaning with subcritical alkali aqueous solution can thoroughly remove silicious contaminants. - Abstract: Four kinds of polyacrylonitrile-based carbon fibers were cleaned by three methods and were characterized by X-ray photoelectron spectroscopy, monofilament tensile strength test and atomic force microscopy (AFM). Experimental results of these tests reveal that the method using supercritical acetone or subcritical potassium hydroxide aqueous solution act as the processing medium shows a better cleaning effect compared to the traditional method, Soxhlet extraction with acetone. The method using supercritical acetone is more appropriate to wipe off the oxygenated contaminants on carbon fibers’ surfaces and causes a relatively smaller damage to the bulk strength of each carbon fiber. As far as treating method using the subcritical alkali aqueous solution, it can thoroughly remove silicious contaminants on the surfaces of treated fibers.

  10. Carbon Nanofibrous Materials from Electrospinning: Preparation and Energy Applications

    Science.gov (United States)

    Aboagye, Alex

    Carbon nanofibers with diameters that fall into submicron and nanometer range have attracted growing attention in recent years due to their superior chemical, electrical, and mechanical properties in combination with their unique one-dimensional nanostructures. Unlike catalytic synthesis, electrospinning polyacrylonitrile (PAN) followed by stabilization and carbonization has become a straightforward and convenient route to make continuous carbon nanofibers. The overall objective of this research was the design and production fiber based carbon nanomaterials, investigation of their structures and use in functional applications. Specifically, these carbon nanofibrous materials were employed as electrode material for energy storage and conversion devices such as dye sensitized solar cells and supercapacitors Morphology and structure of the carbon nanofibrous materials were investigated and their performance in corresponding applications were evaluated.

  11. In-silico Metabolome Target Analysis Towards PanC-based Antimycobacterial Agent Discovery.

    Science.gov (United States)

    Khoshkholgh-Sima, Baharak; Sardari, Soroush; Izadi Mobarakeh, Jalal; Khavari-Nejad, Ramezan Ali

    2015-01-01

    Mycobacterium tuberculosis, the main cause of tuberculosis (TB), has still remained a global health crisis especially in developing countries. Tuberculosis treatment is a laborious and lengthy process with high risk of noncompliance, cytotoxicity adverse events and drug resistance in patient. Recently, there has been an alarming rise of drug resistant in TB. In this regard, it is an unmet need to develop novel antitubercular medicines that target new or more effective biochemical pathways to prevent drug resistant Mycobacterium. Integrated study of metabolic pathways through in-silico approach played a key role in antimycobacterial design process in this study. Our results suggest that pantothenate synthetase (PanC), anthranilate phosphoribosyl transferase (TrpD) and 3-isopropylmalate dehydratase (LeuD) might be appropriate drug targets. In the next step, in-silico ligand analysis was used for more detailed study of chemical tractability of targets. This was helpful to identify pantothenate synthetase (PanC, Rv3602c) as the best target for antimycobacterial design procedure. Virtual library screening on the best ligand of PanC was then performed for inhibitory ligand design. At the end, five chemical intermediates showed significant inhibition of Mycobacterium bovis with good selectivity indices (SI) ≥10 according to Tuberculosis Antimicrobial Acquisition & Coordinating Facility of US criteria for antimycobacterial screening programs.

  12. Adsorption Properties of Lignin-derived Activated Carbon Fibers (LACF)

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gallego, Nidia C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thibaud-Erkey, Catherine [United Technologies Research Center (UTRC), East Hartford, CT (United States); Karra, Reddy [United Technologies Research Center (UTRC), East Hartford, CT (United States)

    2016-04-01

    The object of this CRADA project between Oak Ridge National Laboratory (ORNL) and United Technologies Research Center (UTRC) is the characterization of lignin-derived activated carbon fibers (LACF) and determination of their adsorption properties for volatile organic compounds (VOC). Carbon fibers from lignin raw materials were manufactured at Oak Ridge National Laboratory (ORNL) using the technology previously developed at ORNL. These fibers were physically activated at ORNL using various activation conditions, and their surface area and pore-size distribution were characterized by gas adsorption. Based on these properties, ORNL did down-select five differently activated LACF materials that were delivered to UTRC for measurement of VOC adsorption properties. UTRC used standard techniques based on breakthrough curves to measure and determine the adsorption properties of indoor air pollutants (IAP) - namely formaldehyde and carbon dioxide - and to verify the extent of saturated fiber regenerability by thermal treatments. The results are summarized as follows: (1) ORNL demonstrated that physical activation of lignin-derived carbon fibers can be tailored to obtain LACF with surface areas and pore size distributions matching the properties of activated carbon fibers obtained from more expensive, fossil-fuel precursors; (2) UTRC investigated the LACF potential for use in air cleaning applications currently pursued by UTRC, such as building ventilation, and demonstrated their regenerability for CO2 and formaldehyde, (3) Both partners agree that LACF have potential for possible use in air cleaning applications.

  13. Preparation of a Carbon-Based Solid Acid Catalyst by Sulfonating Activated Carbon in a Chemical Reduction Process

    Directory of Open Access Journals (Sweden)

    Xiao-Yan Liu

    2010-10-01

    Full Text Available Sulfonated (SO3H-bearing activated carbon (AC-SO3H was synthesized by an aryl diazonium salt reduction process. The obtained material had a SO3H density of 0.64 mmol·g-1 and a specific surface area of 602 m2·g-1. The catalytic properties of AC-SO3H were compared with that of two commercial solid acid catalysts, Nafion NR50 and Amberlyst-15. In a 10-h esterification reaction of acetic acid with ethanol, the acid conversion with AC-SO3H (78% was lower than that of Amberlyst-15 (86%, which could be attributed to the fact that the SO3H density of the sulfonated carbon was lower than that of Amberlyst-15 (4.60 mmol·g-1. However, AC-SO3H exhibited comparable and even much higher catalytic activities than the commercial catalysts in the esterification of aliphatic acids with longer carbon chains such as hexanoic acid and decanoic acid, which may be due to the large specific surface area and mesoporous structures of the activated carbon. The disadvantage of AC-SO3H is the leaching of SO3H group during the reactions.

  14. Prevalence of oral lesions in pan vendor

    Directory of Open Access Journals (Sweden)

    Prakash Gadodia

    2011-01-01

    Full Text Available Background: Being a portal of entry to various smoking and smokeless tobacco products, oral cavity is prone to deleterious effects. Present study consist of epidemiological survey to elucidate oral lesions in pan vendors. Aims and objectives: To detect oral lesions in pan vendors and compare it with controls. To detect habit pattern and prevalence of OSMF and other lesions in pan vendors as compared to controls- To identify, recognize and evaluate the possible etiology for OSMF, encompassing various chewing and smoking habits. Materials and methods: Study population consist of 170 pan vendors with age ranging from 15 to 55 years and equal number of sex matched controls selected randomly. Results: Prevalence of oral lesions in pan vendors is statistically significantly higher as compared to controls. The habit of arecanut chewing in various forms was present in all cases. The habit of smoking and smokeless tobacco products was present in all cases. Conclusion: Pan vendors are at higher risk for oral lesions than controls. There is increase in relative risk with increase in duration and frequency of habit.

  15. Characterization of proton conducting blend polymer electrolyte using PVA-PAN doped with NH{sub 4}SCN

    Energy Technology Data Exchange (ETDEWEB)

    Premalatha, M. [PG & Research Department of Physics, N.M.S.S.Vellaichamy Nadar College, Madurai-625 019 (India); Materials Research Center, Coimbatore-641 045 (India); Mathavan, T., E-mail: tjmathavan@gmail.com, E-mail: kingslin.genova20@gmail.com [PG & Research Department of Physics, N.M.S.S.Vellaichamy Nadar College, Madurai-625 019 (India); Selvasekarapandian, S. [Materials Research Center, Coimbatore-641 045 (India); Genova, F. Kingslin Mary, E-mail: tjmathavan@gmail.com, E-mail: kingslin.genova20@gmail.com; Umamaheswari, R. [Department of physics, S.F.R College for Women, Sivakasi-626 128 (India)

    2016-05-23

    Polymer electrolytes with proton conductivity based on blend polymer using polyvinyl alcohol (PVA) and poly acrylo nitrile (PAN) doped with ammonium thiocyanate have been prepared by solution casting method using DMF as solvent. The complex formation between the blend polymer and the salt has been confirmed by FTIR Spectroscopy. The amorphous nature of the blend polymer electrolytes have been confirmed by XRD analysis. The highest conductivity at 303 K has been found to be 3.25 × 10{sup −3} S cm{sup −1} for 20 mol % NH{sub 4}SCN doped 92.5PVA:7.5PAN system. The increase in conductivity of the doped blend polymer electrolytes with increasing temperature suggests the Arrhenius type thermally activated process. The activation energy is found to be low (0.066 eV) for the highest conductivity sample.

  16. Understanding mercury binding on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Padak, B.; Wilcox, J. [Stanford University, Stanford, CA (United States)

    2009-10-15

    Understanding the mechanism by which mercury adsorbs on activated carbon is crucial to the design and fabrication of effective capture technologies. In this study, the possible binding mechanism of mercury (Hg) and its species, i.e., HgCl and HgCl{sub 2} on activated carbon is investigated using ab initio-based energetic calculations. The activated carbon surface is modeled by a single graphene layer in which the edge atoms on the upper side are unsaturated in order to simulate the active sites. in some cases, chlorine atoms are placed at the edge sites to examine the effect of chlorine on the binding of Hg, HgCl and HgCl{sub 2}. It has been concluded that both HgCl and HgCl{sub 2} can be adsorbed dissociatively or non-dissociatively. In the case of dissociative adsorption, it is energetically favorable for atomic Hg to desorb and energetically favorable for it to remain on the surface in the Hg{sup 1+} state, HgCl. The Hg{sup 2+}, oxidized compound, HgCl2 was not found to be stable on the surface. The most probable mercury species on the surface was found to be HgCl.

  17. Activated polyaniline-based carbon nanoparticles for high performance supercapacitors

    International Nuclear Information System (INIS)

    Zhou, Jin; Zhu, Tingting; Xing, Wei; Li, Zhaohui; Shen, Honglong; Zhuo, Shuping

    2015-01-01

    Polyaniline (PANI) nanoparticles have been prepared by disperse polymerization of aniline in the presence of poly(4-styrenesulfonate). The PANI nanoparticles are further subjected to pyrolysis treatment and chemical-activation to prepare the activated nitrogen-doped carbon nanoparticles (APCNs). The porosity, structure and nitrogen-doped surface chemistry are analyzed by a varies of means, such as scanning electron microscopy, transition electron microscopy, N 2 sorption, X-ray diffraction and X-ray photoelectron spectroscopy. The capacitive performance of the APCNs materials are test in 6 M KOH electrolyte. Benefitting from the abundant micropores with short length, large specific surface area, hierarchical porosity and heteroatom-doped polar pore surface, the APCNs materials exhibit v exhibit very high specific capacitance up to 341 F g −1 , remarkable power capability and excellent long-term cyclic stability (96.6% after 10 000 cycles). At 40 A g −1 , APCN-2 carbon shows a capacitance of 164 F g −1 , responding to a high energy and power densities of 5.7 Wh kg −1 and 10 000 W kg −1

  18. On the role of the activation procedure of supported hydrotalcites for base catalyzed reactions: Glycerol to glycerol carbonate and self-condensation of acetone

    NARCIS (Netherlands)

    Alvarez, M.G.; Frey, A.M.; Bitter, J.H.; Segarra, A.M.; Jong, de K.P.; Medina, F.

    2013-01-01

    Bulk and carbon nanofiber supported MgAl hydrotalcites have been investigated as solid base catalysts for the synthesis of glycerol carbonate and dicarbonate and for the self-condensation of acetone. The supported materials exhibited a 300 times higher activity compared to bulk activated

  19. Gel Spun PAN/CNT Based Carbon Fibers with Honey-Comb Cross-Section

    Science.gov (United States)

    2013-11-13

    samples were prepared by mounting a single filament on a copper 3-post TEM grid (Omniprobe) and curing in epoxy (Gatan). The carbon fiber was then... Kevlar ® 49 [28], Zylon® [29], T300 [2], IM10 [30], M60J [31], YS-95A [32] were obtained from the data sheets of these fibers from the respective...made contained 60 vol% fibers in epoxy matrix. Fiber compressive strength may be dependent on fiber structure as well as fiber geometry. Kumar et al

  20. Surface modification of coconut shell based activated carbon for the improvement of hydrophobic VOC removal.

    Science.gov (United States)

    Li, Lin; Liu, Suqin; Liu, Junxin

    2011-08-30

    In this study, coconut shell based carbons were chemically treated by ammonia, sodium hydroxide, nitric acid, sulphuric acid, and phosphoric acid to determine suitable modification for improving adsorption ability of hydrophobic volatile organic compounds (VOCs) on granular activated carbons (GAC). The saturated adsorption capacities of o-xylene, a hydrophobic volatile organic compound, were measured and adsorption effects of the original and modified activated carbons were compared. Results showed that GAC modified by alkalis had better o-xylene adsorption capacity. Uptake amount was enhanced by 26.5% and reduced by 21.6% after modification by NH(3)H(2)O and H(2)SO(4), respectively. Compared with the original, GAC modified by acid had less adsorption capacity. Both SEM/EDAX and BET were used to identify the structural characteristics of the tested GAC, while IR spectroscopy and Boehm's titration were applied to analysis the surface functional groups. Relationships between physicochemical characteristics of GAC and their adsorption performances demonstrated that o-xylene adsorption capacity was related to surface area, pore volume, and functional groups of the GAC surface. Removing surface oxygen groups, which constitute the source of surface acidity, and reducing hydrophilic carbon surface favors adsorption capacity of hydrophobic VOCs on carbons. The performances of modified GACs were also investigated in the purification of gases containing complex components (o-xylene and steam) in the stream. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. The next generation PanDA Pilot for and beyond the ATLAS experiment

    CERN Document Server

    Nilsson, Paul; The ATLAS collaboration

    2018-01-01

    The Production and Distributed Analysis system (PanDA) is a pilot-based workload management system that was originally designed for the ATLAS Experiment at the LHC to operate on grid sites. Since the coming LHC data taking runs will require more resources than grid computing alone can provide, the various LHC experiments are engaged in an ambitious program to extend the computing model to include opportunistically used resources such as High Performance Computers (HPCs), clouds and volunteer computers. To this end, PanDA is being extended beyond grids and ATLAS to be used on the new types of resources as well as by other experiments. A new key component is being developed, the next generation PanDA Pilot (Pilot 2). Pilot 2 is a complete rewrite of the original PanDA Pilot which has been used in the ATLAS Experiment for over a decade. The new Pilot architecture follows a component-based approach which improves system flexibility, enables a clear workflow control, evolves the system according to modern function...

  2. Selecting activated carbon for water and wastewater treatability studies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.; Chang, Q.G.; Liu, W.D.; Li, B.J.; Jiang, W.X.; Fu, L.J.; Ying, W.C. [East China University of Chemical Technology, Shanghai (China)

    2007-10-15

    A series of follow-up investigations were performed to produce data for improving the four-indicator carbon selection method that we developed to identify high-potential activated carbons effective for removing specific organic water pollutants. The carbon's pore structure and surface chemistry are dependent on the raw material and the activation process. Coconut carbons have relatively more small pores than large pores; coal and apricot nutshell/walnut shell fruit carbons have the desirable pore structures for removing adsorbates of all sizes. Chemical activation, excessive activation, and/or thermal reactivation enlarge small pores, resulting in reduced phenol number and higher tannic acid number. Activated carbon's phenol, iodine, methylene blue, and tannic acid numbers are convenient indicators of its surface area and pore volume of pore diameters < 10, 10-15, 15-28, and > 28 angstrom, respectively. The phenol number of a carbon is also a good indicator of its surface acidity of oxygen-containing organic functional groups that affect the adsorptive capacity for aromatic and other small polar organics. The tannic acid number is an indicator of carbon's capacity for large, high-molecular-weight natural organic precursors of disinfection by-products in water treatment. The experimental results for removing nitrobenzene, methyl-tert-butyl ether, 4,4-bisphenol, humic acid, and the organic constituents of a biologically treated coking-plant effluent have demonstrated the effectiveness of this capacity-indicator-based method of carbon selection.

  3. High activity carbon sorbents for mercury capture

    Directory of Open Access Journals (Sweden)

    Stavropoulos George G.

    2006-01-01

    Full Text Available High efficiency activated carbons have been prepared for removing mercury from gas streams. Starting materials used were petroleum coke, lignite, charcoal and olive seed waste, and were chemically activated with KOH. Produced adsorbents were primarily characterized for their porosity by N2 adsorption at 77 K. Their mercury retention capacity was characterized based on the breakthrough curves. Compared with typical commercial carbons, they have exhibited considerably enhanced mercury adsorption capacity. An attempt has been made to correlate mercury entrapment and pore structure. It has been shown that physical surface area is increased during activation in contrast to the mercury adsorption capacity that initially increases and tends to decrease at latter stages. Desorption of active sites may be responsible for this behavior.

  4. Archives: Pan African Medical Journal

    African Journals Online (AJOL)

    Items 1 - 28 of 28 ... Archives: Pan African Medical Journal. Journal Home > Archives: Pan African Medical Journal. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 28 of 28 Items ...

  5. Assessment of the aroma impact of major odor-active thiols in pan-roasted white sesame seeds by calculation of odor activity values.

    Science.gov (United States)

    Tamura, Hitoshi; Fujita, Akira; Steinhaus, Martin; Takahisa, Eisuke; Watanabe, Hiroyuki; Schieberle, Peter

    2011-09-28

    Eleven odor-active thiols, namely, 2-methyl-1-propene-1-thiol, (Z)-3-methyl-1-butene-1-thiol, (E)-3-methyl-1-butene-1-thiol, (Z)-2-methyl-1-butene-1-thiol, (E)-2-methyl-1-butene-1-thiol, 2-methyl-3-furanthiol, 3-mercapto-2-pentanone, 2-mercapto-3-pentanone, 4-mercapto-3-hexanone, 3-mercapto-3-methylbutyl formate, and 2-methyl-3-thiophenethiol, recently identified in an extract prepared from white sesame seeds, were quantitated in sesame using stable isotope dilution analyses. For that purpose, the following deuterium-labeled compounds were synthesized and used as internal standards in the quantitation assays: [2H6]-2-methyl-1-propene-1-thiol, [2H3]-(E)- and [2H3]-(Z)-2-methyl-1-butene-1-thiol, [2H3]-2-methyl-3-furanthiol, [2H2]-3-mercapto-2-pentanone, [2H3]-4-mercapto-3-hexanone, [2H6]-3-mercapto-3-methylbutyl formate, and [2H3]-2-methyl-3-thiophenethiol. On the basis of the results obtained, odor activity values (OAVs) were calculated as ratio of the concentration and odor threshold of the individual compounds in cooking oil. According to their high OAVs, particularly the 3-methyl-1-butene-1-thiols (OAV: 2400) and the 2-methyl-1-butene-1-thiols (OAV: 960) were identified as the most odor-active compounds in pan-roasted white sesame seeds. These compounds were therefore suggested to be mainly responsible for the characteristic but rather unstable sulfury aroma of freshly pan-roasted white sesame seeds.

  6. panMetaDocs and DataSync - providing a convenient way to share and publish research data

    Science.gov (United States)

    Ulbricht, D.; Klump, J. F.

    2013-12-01

    In recent years research institutions, geological surveys and funding organizations started to build infrastructures to facilitate the re-use of research data from previous work. At present, several intermeshed activities are coordinated to make data systems of the earth sciences interoperable and recorded data discoverable. Driven by governmental authorities, ISO19115/19139 emerged as metadata standards for discovery of data and services. Established metadata transport protocols like OAI-PMH and OGC-CSW are used to disseminate metadata to data portals. With the persistent identifiers like DOI and IGSN research data and corresponding physical samples can be given unambiguous names and thus become citable. In summary, these activities focus primarily on 'ready to give away'-data, already stored in an institutional repository and described with appropriate metadata. Many datasets are not 'born' in this state but are produced in small and federated research projects. To make access and reuse of these 'small data' easier, these data should be centrally stored and version controlled from the very beginning of activities. We developed DataSync [1] as supplemental application to the panMetaDocs [2] data exchange platform as a data management tool for small science projects. DataSync is a JAVA-application that runs on a local computer and synchronizes directory trees into an eSciDoc-repository [3] by creating eSciDoc-objects via eSciDocs' REST API. DataSync can be installed on multiple computers and is in this way able to synchronize files of a research team over the internet. XML Metadata can be added as separate files that are managed together with data files as versioned eSciDoc-objects. A project-customized instance of panMetaDocs is provided to show a web-based overview of the previously uploaded file collection and to allow further annotation with metadata inside the eSciDoc-repository. PanMetaDocs is a PHP based web application to assist the creation of metadata in

  7. Landscape Changes and a Salt Production Sustainable Approach in the State of Salt Pan Area Decreasing on the Coast of Tianjin, China

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2015-07-01

    Full Text Available Landsat images from 1979, 1988, 1999, 2008, and 2013 were used to analyze the landscape area change of salt pans lying on the coast of Tianjin. While initially (1979–1988, the area of Tianjin’s salt pan increased, later (1988–2013 it declined dramatically. In the first phase (1979–1988 of the studied period the primary roll-in landscape of the salt pan wasbarren land with an area of 60.0 km2. By 1988, the area of Tianjin’s salt pan rose to 457.8 km2. The main roll-out landscape of the salt pan during 1988–2013 was urban, barren land, village/town, harbor, and road whose area amounted to 69.8, 35.9, 27.3, 25.5 and 18.4 km2 respectively. The roll-out barren land will be transformed to construction land ultimately. By 2013, the total loss reached 167.3 km2, which was 36.5% of the salt pan area of Tianjin in 1988. With the development of coastal economy, the salterns with a lower economic value were transformed to and replaced by land use types with a higher economic value. This trend would influence the production of sea salt and the development of sodium hydroxide and sodium carbonate industries. Seawater desalination provides an opportunity for the restoration and compensation of salt production capacity. Based on the theory of circular economy and industrial symbiosis, in this article an industrial symbiosis model for sea salt production and sea water desalination is explored: “mariculture–power plant cooling–seawater desalination–Artemia culture–bromide extraction–sea salt production–salt chemical industry”. Through the application of this process sustainable development of the sea salt production in Tianjin could be achieved.

  8. Relation between interfacial energy and adsorption of organic micropollutants onto activated carbon

    KAUST Repository

    De Ridder, David J.

    2013-03-01

    The adsorption efficacy of 16 pharmaceuticals on six different activated carbons is correlated to the thermodynamic work of adhesion, which was derived following the surface tension component approach. Immersion calorimetry was used to determine the surface tension components of activated carbon, while contact angle measurements on compressed plates were used to determine these for solutes. We found that the acid-base surface tension components of activated carbon correlated to the activated carbon oxygen content. Solute-water interaction correlated well to their solubility, although four solutes deviated from the trend. In the interaction between solute and activated carbon, van der Waals interactions were dominant and explained 65-94% of the total interaction energy, depending on the hydrophobicity of the activated carbon and solute. A reasonable relationship (r2 > 70) was found between the calculated work of adhesion and the experimentally determined activated carbon loading. © 2012 Elsevier Ltd. All rights reserved.

  9. Relation between interfacial energy and adsorption of organic micropollutants onto activated carbon

    KAUST Repository

    De Ridder, David J.; Verliefde, Arne R. D.; Schoutteten, K.; Van Der Linden, Bart Th; Heijman, Sebastiaan G J; Beurroies, Isabelle; Denoyel, Renaud O.; Amy, Gary L.; Van Dijk, Johannis C.

    2013-01-01

    The adsorption efficacy of 16 pharmaceuticals on six different activated carbons is correlated to the thermodynamic work of adhesion, which was derived following the surface tension component approach. Immersion calorimetry was used to determine the surface tension components of activated carbon, while contact angle measurements on compressed plates were used to determine these for solutes. We found that the acid-base surface tension components of activated carbon correlated to the activated carbon oxygen content. Solute-water interaction correlated well to their solubility, although four solutes deviated from the trend. In the interaction between solute and activated carbon, van der Waals interactions were dominant and explained 65-94% of the total interaction energy, depending on the hydrophobicity of the activated carbon and solute. A reasonable relationship (r2 > 70) was found between the calculated work of adhesion and the experimentally determined activated carbon loading. © 2012 Elsevier Ltd. All rights reserved.

  10. 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

  11. ATLAS WORLD-cloud and networking in PanDA

    Science.gov (United States)

    Barreiro Megino, F.; De, K.; Di Girolamo, A.; Maeno, T.; Walker, R.; ATLAS Collaboration

    2017-10-01

    The ATLAS computing model was originally designed as static clouds (usually national or geographical groupings of sites) around the Tier 1 centres, which confined tasks and most of the data traffic. Since those early days, the sites’ network bandwidth has increased at 0(1000) and the difference in functionalities between Tier 1s and Tier 2s has reduced. After years of manual, intermediate solutions, we have now ramped up to full usage of World-cloud, the latest step in the PanDA Workload Management System to increase resource utilization on the ATLAS Grid, for all workflows (MC production, data (re)processing, etc.). We have based the development on two new site concepts. Nuclei sites are the Tier 1s and large Tier 2s, where tasks will be assigned and the output aggregated, and satellites are the sites that will execute the jobs and send the output to their nucleus. PanDA dynamically pairs nuclei and satellite sites for each task based on the input data availability, capability matching, site load and network connectivity. This contribution will introduce the conceptual changes for World-cloud, the development necessary in PanDA, an insight into the network model and the first half-year of operational experience.

  12. Molecular modeling of the microstructure evolution during carbon fiber processing

    Science.gov (United States)

    Desai, Saaketh; Li, Chunyu; Shen, Tongtong; Strachan, Alejandro

    2017-12-01

    The rational design of carbon fibers with desired properties requires quantitative relationships between the processing conditions, microstructure, and resulting properties. We developed a molecular model that combines kinetic Monte Carlo and molecular dynamics techniques to predict the microstructure evolution during the processes of carbonization and graphitization of polyacrylonitrile (PAN)-based carbon fibers. The model accurately predicts the cross-sectional microstructure of the fibers with the molecular structure of the stabilized PAN fibers and physics-based chemical reaction rates as the only inputs. The resulting structures exhibit key features observed in electron microcopy studies such as curved graphitic sheets and hairpin structures. In addition, computed X-ray diffraction patterns are in good agreement with experiments. We predict the transverse moduli of the resulting fibers between 1 GPa and 5 GPa, in good agreement with experimental results for high modulus fibers and slightly lower than those of high-strength fibers. The transverse modulus is governed by sliding between graphitic sheets, and the relatively low value for the predicted microstructures can be attributed to their perfect longitudinal texture. Finally, the simulations provide insight into the relationships between chemical kinetics and the final microstructure; we observe that high reaction rates result in porous structures with lower moduli.

  13. TESTING GUIDELINES FOR TECHNETIUM-99 ADSORPTION ON ACTIVATED CARBON

    International Nuclear Information System (INIS)

    Byrnes, M.E.

    2010-01-01

    CH2M HILL Plateau Remediation Company (CHPRC) is currently evaluating the potential use of activated carbon adsorption for removing technetium-99 from groundwater as a treatment method for the Hanford Site's 200 West Area groundwater pump-and-treat system. The current pump-and-treat system design will include an ion-exchange (IX) system for selective removal of technetium-99 from selected wells prior to subsequent treatment of the water in the central treatment system. The IX resin selected for technetium-99 removal is Purolite A530E. The resin service life is estimated to be approximately 66.85 days at the design technetium-99 loading rate, and the spent resin must be replaced because it cannot be regenerated. The resulting operating costs associated with resin replacement every 66.85 days are estimated at $0.98 million/year. Activated carbon pre-treatment is being evaluated as a potential cost-saving measure to offset the high operating costs associated with frequent IX resin replacement. This document is preceded by the Literature Survey of Technetium-99 Groundwater Pre-Treatment Option Using Granular Activated Carbon (SGW-43928), which identified and evaluated prior research related to technetium-99 adsorption on activated carbon. The survey also evaluated potential operating considerations for this treatment approach for the 200 West Area. The preliminary conclusions of the literature survey are as follows: (1) Activated carbon can be used to selectively remove technetium-99 from contaminated groundwater. (2) Technetium-99 adsorption onto activated carbon is expected to vary significantly based on carbon types and operating conditions. For the treatment approach to be viable at the Hanford Site, activated carbon must be capable of achieving a designated minimum technetium-99 uptake. (3) Certain radionuclides known to be present in 200 West Area groundwater are also likely to adsorb onto activated carbon. (4) Organic solvent contaminants of concern (COCs) will

  14. TESTING GUIDELINES FOR TECHNETIUM-99 ABSORPTION ON ACTIVATED CARBON

    Energy Technology Data Exchange (ETDEWEB)

    BYRNES ME

    2010-09-08

    CH2M HILL Plateau Remediation Company (CHPRC) is currently evaluating the potential use of activated carbon adsorption for removing technetium-99 from groundwater as a treatment method for the Hanford Site's 200 West Area groundwater pump-and-treat system. The current pump-and-treat system design will include an ion-exchange (IX) system for selective removal of technetium-99 from selected wells prior to subsequent treatment of the water in the central treatment system. The IX resin selected for technetium-99 removal is Purolite A530E. The resin service life is estimated to be approximately 66.85 days at the design technetium-99 loading rate, and the spent resin must be replaced because it cannot be regenerated. The resulting operating costs associated with resin replacement every 66.85 days are estimated at $0.98 million/year. Activated carbon pre-treatment is being evaluated as a potential cost-saving measure to offset the high operating costs associated with frequent IX resin replacement. This document is preceded by the Literature Survey of Technetium-99 Groundwater Pre-Treatment Option Using Granular Activated Carbon (SGW-43928), which identified and evaluated prior research related to technetium-99 adsorption on activated carbon. The survey also evaluated potential operating considerations for this treatment approach for the 200 West Area. The preliminary conclusions of the literature survey are as follows: (1) Activated carbon can be used to selectively remove technetium-99 from contaminated groundwater. (2) Technetium-99 adsorption onto activated carbon is expected to vary significantly based on carbon types and operating conditions. For the treatment approach to be viable at the Hanford Site, activated carbon must be capable of achieving a designated minimum technetium-99 uptake. (3) Certain radionuclides known to be present in 200 West Area groundwater are also likely to adsorb onto activated carbon. (4) Organic solvent contaminants of concern (COCs

  15. The next generation of the ATLAS PanDA Monitoring System

    CERN Document Server

    Schovancova, J; The ATLAS collaboration; Klimentov, A; Love, P; Potekhin, M; Wenaus, T

    2014-01-01

    For many years the PanDA Workload Management System has been the basis for distributed production and analysis for the ATLAS experiment at the LHC. Since the start of data taking PanDA usage has ramped up steadily, with up to 1M completed jobs/day in 2013. The associated monitoring data volume has been rising as well, to levels that present a new set of challenges in the areas of database scalability and monitoring system performance and efficiency. Outside of ATLAS, the PanDA system is also being used in projects like AMS, LSST and a few others. It currently undergoes a significant redesign, both of the core server components responsible for workload management, brokerage and data access, and of the monitoring part, which is critically important for efficient execution of the workflow in a way that’s transparent to the user and also provides an effective set of tools for operational support. The new generation of the PanDA Monitoring Service is designed based on a proven, scalable, industry-standard Web Fr...

  16. PanDA Pilot Submission using Condor-G: Experience and Improvements

    CERN Document Server

    Zhao, Xin; The ATLAS collaboration; Wlodek, Tom; Wenaus, Torre; Frey, Jaime; Tannenbaum, Todd; Livny, Miron

    2010-01-01

    PanDA is the workload management system of the ATLAS experiment, used to run production and user analysis jobs on the grid. As a late-binding, pilot-based system, the maintenance of a smooth and steady stream of pilot jobs to all grid sites is critical for PanDA operation. The ATLAS Computing Facility (ACF) at BNL, as the ATLAS Tier 1 center in the US, operates the pilot submission systems for the US. This is done using the PanDA "AutoPilot" scheduler component which submits pilot jobs via Condor-G, a grid job scheduling system developed at the University of Wisconsin-Madison. In this talk, we discuss the operation and performance of the Condor-G pilot submission at BNL, with emphasis on the challenges and issues encountered in the real grid production environment. With the close collaboration of Condor and PanDA teams, the scalability and stability of the overall system has been greatly improved over the last year. We review improvements made to Condor-G resulting from this collaboration, including isolation...

  17. PanDA Pilot Submission using Condor-G: Experience and Improvements

    CERN Document Server

    Zhao, X; The ATLAS collaboration; Wlodek, T; Wenaus, T; Frey, J; Tannenbaum, T; Livny, M

    2011-01-01

    PanDA (Production and Distributed Analysis) is the workload management system of the ATLAS experiment, used to run managed production and user analysis jobs on the grid. As a late-binding, pilot-based system, the maintenance of a smooth and steady stream of pilot jobs to all grid sites is critical for PanDA operation. The ATLAS Computing Facility (ACF) at BNL, as the ATLAS Tier1 center in the US, operates the pilot submission systems for the US. This is done using the PanDA “AutoPilot” scheduler component which submits pilot jobs via Condor-G, a grid job scheduling system developed at the University of Wisconsin-Madison. In this paper, we discuss the operation and performance of the Condor-G pilot submission at BNL, with emphasis on the challenges and issues encountered in the real grid production environment. With the close collaboration of Condor and PanDA teams, the scalability and stability of the overall system has been greatly improved over the last year. We review improvements made to Condor-G resu...

  18. Self-floating graphitic carbon nitride/zinc phthalocyanine nanofibers for photocatalytic degradation of contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tiefeng; Ni, Dongjing; Chen, Xia; Wu, Fei; Ge, Pengfei; Lu, Wangyang, E-mail: luwy@zstu.edu.cn; Hu, Hongguang; Zhu, ZheXin; Chen, Wenxing, E-mail: wxchen@zstu.edu.cn

    2016-11-05

    Highlights: • A facile synthetic strategy to prepare visible-light responsive electrospun nanofibers. • Self-floating nanofiber photocatalyts for the effective utilization of solar. • Possible degradation pathway of RhB and CBZ under visible light and solar irradiation. • Present a method for removing highly hazardous contaminants. - Abstract: The effective elimination of micropollutants by an environmentally friendly method has received extensive attention recently. In this study, a photocatalyst based on polyacrylonitrile (PAN)-supported graphitic carbon nitride coupled with zinc phthalocyanine nanofibers (g-C{sub 3}N{sub 4}/ZnTcPc/PAN nanofibers) was successfully prepared, where g-C{sub 3}N{sub 4}/ZnTcPc was introduced as the catalytic entity and the PAN nanofibers were employed as support to overcome the defects of easy aggregation and difficult recycling. Herein, rhodamine B (RhB), 4-chlorophenol and carbamazepine (CBZ) were selected as the model pollutants. Compared with the typical hydroxyl radical-dominated catalytic system, g-C{sub 3}N{sub 4}/ZnTcPc/PAN nanofibers displayed the targeted adsorption and degradation of contaminants under visible light or solar irradiation in the presence of high additive concentrations. According to the results of the radical scavenging techniques and the electron paramagnetic resonance technology, the degradation of target substrates was achieved by the attack of active species, including photogenerated hole, singlet oxygen, superoxide radicals and hydroxyl radicals. Based on the results of ultra-performance liquid chromatography and mass spectrometry, the role of free radicals on the photocatalytic degradation intermediates was identified and the final photocatalytic degradation products of both RhB and CBZ were some biodegradable small molecules.

  19. CanWEA Pan-Canadian wind integration study paper

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, Martin [GL Garrad Hassan Canada Inc, Ottawa, ON (Canada); Gardner, Paul [GL Garrad Hassan and Partners, Glasgow (United Kingdom); Price, Doug; Le, Don [GL Garrad Hassan America, San Diego, CA (United States)

    2010-07-01

    GL Garrad Hassan has been contracted by CanWEA to undertake a scoping study for a future Pan-Canadian Wide-Scale Wind Integration Study. The scoping study provides the methodology and the rationale on which the actual wind integration study and request for proposals will be based on. Major system operators and owners of each Canadian Province along with experts involved in major US wind integration studies have been consulted and contributed to the decisional process. This paper provides a summary of the factors considered in the study and outline the actual methodology that was adopted for the future Pan-Canadian wind integration study. (orig.)

  20. Pan-European management of electricity portfolios: Risks and opportunities of contract bundling

    International Nuclear Information System (INIS)

    Gampert, Markus; Madlener, Reinhard

    2011-01-01

    Due to the liberalization of energy markets in the European Union, today's European utilities not only focus on electricity supply, but also offer exchange-traded 'structured products' or portfolio management for unbundling financial and physical risk positions. Many utilities are only able to provide these services in their domestic markets. In a globalized economy, the need for a centrally organized pan-European portfolio management has arisen, as it allows a simplified commodity sourcing in combination with an optimized risk management. In this paper, we examine the challenges to be overcome for establishing a European-wide bundling of electricity contracts. For this purpose, a case study based on the business perspective of RWE Supply and Trading in Central and Eastern Europe is carried out. In a first step, we analyze general requirements for a pan-European bundling of electricity contracts. Then, RWE's situation in Europe is examined, based on which we finally propose a concept to meet customer demands in Central and Eastern Europe. - Research highlights: → Analysis of electricity market liberalization in Central and Eastern Europe. → Identification of requirements and problems for pan-European bundling of contracts. → Case study based on RWE Supply and Trading perspective in Central and Eastern Europe. → Model development for pan-European unbundling of financial/physical risk positions.

  1. Compilation of PRF Canyon Floor Pan Sample Analysis Results

    Energy Technology Data Exchange (ETDEWEB)

    Pool, Karl N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Minette, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wahl, Jon H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greenwood, Lawrence R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Deborah S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McNamara, Bruce K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scheele, Randall D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Delegard, Calvin H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brown, Garrett N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clark, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-06-30

    On September 28, 2015, debris collected from the PRF (236-Z) canyon floor, Pan J, was observed to exhibit chemical reaction. The material had been transferred from the floor pan to a collection tray inside the canyon the previous Friday. Work in the canyon was stopped to allow Industrial Hygiene to perform monitoring of the material reaction. Canyon floor debris that had been sealed out was sequestered at the facility, a recovery plan was developed, and drum inspections were initiated to verify no additional reactions had occurred. On October 13, in-process drums containing other Pan J material were inspected and showed some indication of chemical reaction, limited to discoloration and degradation of inner plastic bags. All Pan J material was sealed back into the canyon and returned to collection trays. Based on the high airborne levels in the canyon during physical debris removal, ETGS (Encapsulation Technology Glycerin Solution) was used as a fogging/lock-down agent. On October 15, subject matter experts confirmed a reaction had occurred between nitrates (both Plutonium Nitrate and Aluminum Nitrate Nonahydrate (ANN) are present) in the Pan J material and the ETGS fixative used to lower airborne radioactivity levels during debris removal. Management stopped the use of fogging/lock-down agents containing glycerin on bulk materials, declared a Management Concern, and initiated the Potential Inadequacy in the Safety Analysis determination process. Additional drum inspections and laboratory analysis of both reacted and unreacted material are planned. This report compiles the results of many different sample analyses conducted by the Pacific Northwest National Laboratory on samples collected from the Plutonium Reclamation Facility (PRF) floor pans by the CH2MHill’s Plateau Remediation Company (CHPRC). Revision 1 added Appendix G that reports the results of the Gas Generation Rate and methodology. The scope of analyses requested by CHPRC includes the determination of

  2. The influence of Mn species on the SO2 removal of Mn-based activated carbon catalysts

    International Nuclear Information System (INIS)

    Qu, Yi-Fan; Guo, Jia-Xiu; Chu, Ying-Hao; Sun, Ming-Chao; Yin, Hua-Qiang

    2013-01-01

    Using Mn(NO 3 ) 2 as precursor, a series of Mn-based activated carbon catalysts were prepared by ultrasound-assisted excessive impregnation method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The influences of Mn species and nitric acid pretreatment on the removal role of SO 2 were investigated. MnO and Mn 3 O 4 coexist in catalysts calcined at 650 and 800 °C and exhibit best SO 2 removal ability, whereas Mn 2 O 3 formed in the catalyst calcined at 500 °C and shows poor activity. After treatment by nitric acid, the C=O of activated carbon support increases and the crystal size of MnO decreases, resulting in the enhancement of the catalytic activity. During reaction process, manganese oxides are gradually transferred into MnO 2 . And this change directly results in a decrease of activity. But the SO 2 removal rate has been maintained in the range of 30–40%, indicating that MnO 2 still has a certain SO 2 removal ability.

  3. Effect of the nature the carbon precursor on the physico-chemical characteristics of the resulting activated carbon materials

    International Nuclear Information System (INIS)

    Jimenez, Vicente; Sanchez, Paula; Valverde, Jose Luis; Romero, Amaya

    2010-01-01

    Carbon materials, including amorphous carbon, graphite, carbon nanospheres (CNSs) and different types of carbon nanofibers (CNFs) [platelet, herringbone and ribbon], were chemically activated using KOH. The pore structure of carbon materials was analyzed using N 2 /77 K adsorption isotherms. The presence of oxygen groups was analyzed by temperature programmed desorption in He and acid-base titration. The structural order of the materials was studied by X-ray diffraction and temperature programmed oxidation. The morphology and diameter distribution of CNFs and CNSs were characterized by transmission electron microscopy. The materials were also characterized by temperature-desorption programmed of H 2 and elemental composition. The ways in which the different structures were activated are described, showing the type of pores generated. Relationships between carbon yield, removed carbon, activation degree and graphitic character were also examined. The oxygen content in the form of oxygen-containing surface groups increased after the activation giving qualitative information about them. The average diameter of both CNFs and CNSs was decreased after the activation process as consequence of the changes produced on the material surface.

  4. Effect of the nature the carbon precursor on the physico-chemical characteristics of the resulting activated carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Vicente, E-mail: vicente.jimenez@uclm.es [Facultad de Ciencias Quimicas, Departamento de Ingenieria Quimica, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Sanchez, Paula; Valverde, Jose Luis [Facultad de Ciencias Quimicas, Departamento de Ingenieria Quimica, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Romero, Amaya [Escuela Tecnica Agricola, Departamento de Ingenieria Quimica, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2010-11-01

    Carbon materials, including amorphous carbon, graphite, carbon nanospheres (CNSs) and different types of carbon nanofibers (CNFs) [platelet, herringbone and ribbon], were chemically activated using KOH. The pore structure of carbon materials was analyzed using N{sub 2}/77 K adsorption isotherms. The presence of oxygen groups was analyzed by temperature programmed desorption in He and acid-base titration. The structural order of the materials was studied by X-ray diffraction and temperature programmed oxidation. The morphology and diameter distribution of CNFs and CNSs were characterized by transmission electron microscopy. The materials were also characterized by temperature-desorption programmed of H{sub 2} and elemental composition. The ways in which the different structures were activated are described, showing the type of pores generated. Relationships between carbon yield, removed carbon, activation degree and graphitic character were also examined. The oxygen content in the form of oxygen-containing surface groups increased after the activation giving qualitative information about them. The average diameter of both CNFs and CNSs was decreased after the activation process as consequence of the changes produced on the material surface.

  5. Effect of commercial activated carbons in sulfur cathodes on the electrochemical properties of lithium/sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo; Kim, Icpyo [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Kim, Ki-Won; Nam, Tae-Hyun; Cho, Kwon-Koo; Ahn, Jou-Hyeon [Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Ryu, Ho-Suk [Department of Material and Energy Engineering, Gyeongwoon University, 730, Gangdong-ro, Sandong-myeon, Gumi, Gyeongbuk, 39160 (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of)

    2016-10-15

    Highlights: • The sulfur/activated carbon composite is fabricated using commercial activated carbons. • The sulfur/activated carbon composite with coal shows the best performance. • The Li/S battery has capacities of 1240 mAh g{sup −1} at 1 C and 567 mAh g{sup −1} at 10 C. - Abstract: We prepared sulfur/active carbon composites via a simple solution-based process using the following commercial activated carbon-based materials: coal, coconut shells, and sawdust. Although elemental sulfur was not detected in any of the sulfur/activated carbon composites based on Thermogravimetric analysis, X-ray diffraction, and Raman spectroscopy, Energy-dispersive X-ray spectroscopy results confirmed its presence in the activated carbon. These results indicate that sulfur was successfully impregnated in the activated carbon and that all of the activated carbons acted as sulfur reservoirs. The sulfur/activated carbon composite cathode using coal exhibited the highest discharge capacity and best rate capability. The first discharge capacity at 1 C (1.672 A g{sup −1}) was 1240 mAh g{sup −1}, and a large reversible capacity of 567 mAh g{sup −1} was observed at 10 C (16.72 A g{sup −1}).

  6. Pan-genome and phylogeny of Bacillus cereus sensu lato.

    Science.gov (United States)

    Bazinet, Adam L

    2017-08-02

    Bacillus cereus sensu lato (s. l.) is an ecologically diverse bacterial group of medical and agricultural significance. In this study, I use publicly available genomes and novel bioinformatic workflows to characterize the B. cereus s. l. pan-genome and perform the largest phylogenetic and population genetic analyses of this group to date in terms of the number of genes and taxa included. With these fundamental data in hand, I identify genes associated with particular phenotypic traits (i.e., "pan-GWAS" analysis), and quantify the degree to which taxa sharing common attributes are phylogenetically clustered. A rapid k-mer based approach (Mash) was used to create reduced representations of selected Bacillus genomes, and a fast distance-based phylogenetic analysis of this data (FastME) was performed to determine which species should be included in B. cereus s. l. The complete genomes of eight B. cereus s. l. species were annotated de novo with Prokka, and these annotations were used by Roary to produce the B. cereus s. l. pan-genome. Scoary was used to associate gene presence and absence patterns with various phenotypes. The orthologous protein sequence clusters produced by Roary were filtered and used to build HaMStR databases of gene models that were used in turn to construct phylogenetic data matrices. Phylogenetic analyses used RAxML, DendroPy, ClonalFrameML, PAUP*, and SplitsTree. Bayesian model-based population genetic analysis assigned taxa to clusters using hierBAPS. The genealogical sorting index was used to quantify the phylogenetic clustering of taxa sharing common attributes. The B. cereus s. l. pan-genome currently consists of ≈60,000 genes, ≈600 of which are "core" (common to at least 99% of taxa sampled). Pan-GWAS analysis revealed genes associated with phenotypes such as isolation source, oxygen requirement, and ability to cause diseases such as anthrax or food poisoning. Extensive phylogenetic analyses using an unprecedented amount of data

  7. Radionuclide concentrations in salt pans in the coastal area of Cox's Bazar, Bangladesh

    International Nuclear Information System (INIS)

    Alam, M.N.; Chowdhury, M.I.; Zafar, M.; Kamal, M.; Ghose, S.; Kamal, A.H.M.

    1998-01-01

    Radionuclide concentrations of 226 Ra, 232 Th, 137 Cs, 134 Cs and 40 K in samples of water, soil and salt from three gradients of salt pans (reservoir, condenser and crystalliser) in the coastal area of Cox's Bazar, Bangladesh and in samples of refined salts were measured using γ-spectrometry. The activities of 226 Ra in the salt pans were found to be in the range 3·18±1·02 Bq l -1 in water to 25·17±5·76 Bq kg -1 in soil; 232 Th activities were 2·01±0·89 Bq l -1 in water to 42·33±2·54 Bq kg -1 in soil, and 40 K activities ranged from 109·60±27·77 Bq l -1 in water to 651·89±65·89 Bq kg -1 in soil. No 137 Cs or 134 Cs was found in soil, salt and water from the salt pans investigated. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  8. 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.

  9. Overview of ATLAS PanDA Workload Management

    Science.gov (United States)

    Maeno, T.; De, K.; Wenaus, T.; Nilsson, P.; Stewart, G. A.; Walker, R.; Stradling, A.; Caballero, J.; Potekhin, M.; Smith, D.; ATLAS Collaboration

    2011-12-01

    The Production and Distributed Analysis System (PanDA) plays a key role in the ATLAS distributed computing infrastructure. All ATLAS Monte-Carlo simulation and data reprocessing jobs pass through the PanDA system. We will describe how PanDA manages job execution on the grid using dynamic resource estimation and data replication together with intelligent brokerage in order to meet the scaling and automation requirements of ATLAS distributed computing. PanDA is also the primary ATLAS system for processing user and group analysis jobs, bringing further requirements for quick, flexible adaptation to the rapidly evolving analysis use cases of the early datataking phase, in addition to the high reliability, robustness and usability needed to provide efficient and transparent utilization of the grid for analysis users. We will describe how PanDA meets ATLAS requirements, the evolution of the system in light of operational experience, how the system has performed during the first LHC data-taking phase and plans for the future.

  10. Overview of ATLAS PanDA Workload Management

    International Nuclear Information System (INIS)

    Maeno, T.; De, K.; Wenaus, T.; Nilsson, P.; Stewart, G.A.; Walker, R.; Stradling, A.; Caballero, J.; Potekhin, M.; Smith, D.

    2011-01-01

    The Production and Distributed Analysis System (PanDA) plays a key role in the ATLAS distributed computing infrastructure. All ATLAS Monte-Carlo simulation and data reprocessing jobs pass through the PanDA system. We will describe how PanDA manages job execution on the grid using dynamic resource estimation and data replication together with intelligent brokerage in order to meet the scaling and automation requirements of ATLAS distributed computing. PanDA is also the primary ATLAS system for processing user and group analysis jobs, bringing further requirements for quick, flexible adaptation to the rapidly evolving analysis use cases of the early datataking phase, in addition to the high reliability, robustness and usability needed to provide efficient and transparent utilization of the grid for analysis users. We will describe how PanDA meets ATLAS requirements, the evolution of the system in light of operational experience, how the system has performed during the first LHC data-taking phase and plans for the future.

  11. 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

  12. Evolution of the ATLAS PanDA Production and Distributed Analysis System

    International Nuclear Information System (INIS)

    Maeno, T; Wenaus, T; Fine, V; Potekhin, M; Panitkin, S; De, K; Nilsson, P; Stradling, A; Walker, R; Compostella, G

    2012-01-01

    The PanDA (Production and Distributed Analysis) system has been developed to meet ATLAS production and analysis requirements for a data-driven workload management system capable of operating at LHC data processing scale. PanDA has performed well with high reliability and robustness during the two years of LHC data-taking, while being actively evolved to meet the rapidly changing requirements for analysis use cases. We will present an overview of system evolution including automatic rebrokerage and reattempt for analysis jobs, adaptation for the CernVM File System, support for the multi-cloud model through which Tier-2 sites act as members of multiple clouds, pledged resource management and preferential brokerage, and monitoring improvements. We will also describe results from the analysis of two years of PanDA usage statistics, current issues, and plans for the future.

  13. Granular activated carbons from broiler manure: physical, chemical and adsorptive properties.

    Science.gov (United States)

    Lima, Isabel M; Marshall, Wayne E

    2005-04-01

    Broiler manure produced at large concentrated facilities poses risks to the quality of water and public health. This study utilizes broiler litter and cake as source materials for granular activated carbon production and optimizes conditions for their production. Pelletized manure samples were pyrolyzed at 700 degrees C for 1 h followed by activation in an inert atmosphere under steam at different water flow rates, for a period ranging from 15 to 75 min. Carbon physical and adsorptive properties were dependent on activation time and quantity of steam used as activant, yields varied from 18% to 28%, surface area varied from 253 to 548 m2/g and copper ion adsorption varied from 0.13 to 1.92 mmol Cu2+/g carbon. Best overall performing carbons were steam activated for 45 min at 3 ml/min. Comparative studies with commercial carbons revealed the broiler cake-based carbon as having the highest copper ion efficiency.

  14. Student-Centered Designs of Pan-African Literature Courses

    Science.gov (United States)

    M'Baye, Babacar

    2010-01-01

    A student-centered teaching methodology is an essential ingredient of a successful Pan-African literary course. In this article, the author defines Pan-Africanism and how to go about designing a Pan-African literature course. The author combines reading assignments with journals, film presentations, and lectures in a productive learning…

  15. THE EFFECT OF ACTIVATED CARBON SURFACE MOISTURE ON LOW TEMPERATURE MERCURY ADSORPTION

    Science.gov (United States)

    Experiments with elemental mercury (Hg0) adsorption by activated carbons were performed using a bench-scale fixed-bed reactor at room temperature (27 degrees C) to determine the role of surface moisture in capturing Hg0. A bituminous-coal-based activated carbon (BPL) and an activ...

  16. Surface properties of poly(acrylonitrile) (PAN) precipitation polymerized in supercritical CO2 and the influence of the molecular weight.

    Science.gov (United States)

    Shen, Qing; Gu, Qing-Feng; Hu, Jian-Feng; Teng, Xin-Rong; Zhu, Yun-Feng

    2003-11-15

    In this paper, the surface properties, e.g., the total surface free energy and the related Lifshitz-van der Waals and Lewis acid-base components, of polyacrylonitrile (PAN) precipitation polymerized in supercritical CO(2) have been characterized. Moreover, the influence of molecular weight varying has been also investigated. Results show that the surface properties of PAN resulting from supercritical CO(2) are different from those obtained by the conventional method. Of these data, one important finding is that the supercritical CO(2) PAN seems to decrease the surface free energy with the increased molecular weight. Based on previous recorded NMR spectra of this PAN and especially compared to commercial PAN, such phenomena are discussed and ascribed to an increase of the H-bonds and a reduction of the isotacticity in the supercritical CO(2) condition for PAN.

  17. 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.

  18. HEALTH INITIATIVES IN NATIONAL PAN-AMERICAN SWIMMING FEDERATIONS

    Directory of Open Access Journals (Sweden)

    Clarence Perez Diaz

    Full Text Available ABSTRACT Introduction: National Swimming Federations (NFs supervise a large number of athletes and have the duty to protect their health that implies also the opportunity to improve public health. Objective: 1 To determine if the health professionals, the priorities, activities, and researches of the Pan-American NFs are focused on protecting athletes’ health and promoting the health of the population in general. 2 To determine if the FINA rules, projects and programs are applied. Method: A cross-sectional descriptive survey was carried out among the 45 Pan-American NFs requesting information on the profile of the health professionals (dimension 1; D1, on programs, activities and research to promote health measures (dimension 2; D2, and on the importance of Pan-American NFs for the health of athletes and for the promotion of health in society in general (dimension 3; D3. We performed a similarity study according to the Rogers-Tanimoto coefficient (D1 and D2 and the chi-squared test (χ² (D3. Results: Thirty NFs answered the survey (response rate: 66.6%. For each dimension, the NFs were classified into five groups (A, B, C, D, E. Among the NFs, 33.3% have physicians and 33.3% have physical therapists. In each of the dimensions, Group A accounted for the majority of NFs but their results were lower. The groups with the highest rates in each dimension contained a maximum of two NFs. The health of the elite athletes was ranked as the fourth most important issue. The health of the recreational athletes and the health of the general population had the lowest priority. Drowning prevention programs were the most common. Conclusions: Pan-American NFs have few medical resources and only a few have injury prevention programs for elite athletes. There is a need to improve health promotion programs to achieve relevant social outcomes.

  19. Effect of particulate matrix inhibitors on microstructure and properties of 2-D carbon-carbon composites

    International Nuclear Information System (INIS)

    Tlomak, P.; Takano, Shigeru; Wright, M.A.; Ju, Chien-Ping.

    1991-01-01

    Extended-life applications of structural carbon-carbon (C-C) composites involve multiple periods of operation in high-temperature oxidizing environments and as such require a reliable oxidation protection system (OPS). Advanced OPS's generally consist of an external ceramic coating combined with an in-depth matrix inhibitor. This work investigated the effects produced by particulate inhibitors doped on the matrix on the microstructure of 2D, PAN fiber-pitch matrix C-C's. Boron and zirconium-based particulate inhibitors were added to the matrix material prior to heat treatment. A process was developed to assure a uniform distribution of the inhibitors. Oxidation behavior of such matrix-inhibited composites was evaluated using isothermal oxidation tests. 5 refs

  20. THE PHOTOMETRIC CLASSIFICATION SERVER FOR Pan-STARRS1

    International Nuclear Information System (INIS)

    Saglia, R. P.; Bender, R.; Seitz, S.; Senger, R.; Snigula, J.; Phleps, S.; Wilman, D.; Tonry, J. L.; Burgett, W. S.; Chambers, K. C.; Heasley, J. N.; Kaiser, N.; Magnier, E. A.; Morgan, J. S.; Greisel, N.; Bailer-Jones, C. A. L.; Klement, R. J.; Rix, H.-W.; Smith, K.; Green, P. J.

    2012-01-01

    The Pan-STARRS1 survey is obtaining multi-epoch imaging in five bands (g P1 r P1 i P1 z P1 y P1 ) over the entire sky north of declination –30 deg. We describe here the implementation of the Photometric Classification Server (PCS) for Pan-STARRS1. PCS will allow the automatic classification of objects into star/galaxy/quasar classes based on colors and the measurement of photometric redshifts for extragalactic objects, and will constrain stellar parameters for stellar objects, working at the catalog level. We present tests of the system based on high signal-to-noise photometry derived from the Medium-Deep Fields of Pan-STARRS1, using available spectroscopic surveys as training and/or verification sets. We show that the Pan-STARRS1 photometry delivers classifications and photometric redshifts as good as the Sloan Digital Sky Survey (SDSS) photometry to the same magnitude limits. In particular, our preliminary results, based on this relatively limited data set down to the SDSS spectroscopic limits, and therefore potentially improvable, show that stars are correctly classified as such in 85% of cases, galaxies in 97%, and QSOs in 84%. False positives are less than 1% for galaxies, ≈19% for stars, and ≈28% for QSOs. Moreover, photometric redshifts for 1000 luminous red galaxies up to redshift 0.5 are determined to 2.4% precision (defined as 1.48 × Median|z phot – z spec |/(1 + z)) with just 0.4% catastrophic outliers and small (–0.5%) residual bias. For bluer galaxies up to the same redshift, the residual bias (on average –0.5%) trend, percentage of catastrophic failures (1.2%), and precision (4.2%) are higher, but still interestingly small for many science applications. Good photometric redshifts (to 5%) can be obtained for at most 60% of the QSOs of the sample. PCS will create a value-added catalog with classifications and photometric redshifts for eventually many millions of sources.

  1. 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.

  2. Is Pan-Asian Economic Integration Moving Forward?: Evidence from Pan-Asian Trade Statistics

    OpenAIRE

    Sapkota, Jeet Bahadur; Shuto, Motoko

    2016-01-01

    Asia is growing economically faster than any other region in the world; this led to the shift of the center of gravity of the global economy from the West to the East. However, it is not clear whether the Asian economy is integrating regionally or globally. In the context of the growing efforts of regional or sub-regional pan-Asian integration, it is worthwhile to explore the pan-Asian trade flows regionally as well as globally. Thus, this paper examines the trend and determinants of economic...

  3. Carbon- versus sulphur-based zinc binding groups for carbonic anhydrase inhibitors?

    Science.gov (United States)

    Supuran, Claudiu T

    2018-12-01

    A set of compounds incorporating carbon-based zinc-binding groups (ZBGs), of the type PhX (X = COOH, CONH 2 , CONHNH 2 , CONHOH, CONHOMe), and the corresponding derivatives with sulphur(VI)-based ZBGs (X = SO 3 H, SO 2 NH 2 , SO 2 NHNH 2 , SO 2 NHOH, SO 2 NHOMe) were tested as inhibitors of all mammalian isoforms of carbonic anhydrase (CA, EC 4.2.1.1), CA I-XV. Three factors connected with the ZBG influenced the efficacy as CA inhibitor (CAI) of the investigated compounds: (i) the pKa of the ZBG; (ii) its geometry (tetrahedral, i.e. sulphur-based, versus trigonal, i.e. carbon-based ZBGs), and (iii) orientation of the organic scaffold induced by the nature of the ZBG. Benzenesulphonamide was the best inhibitor of all isoforms, but other ZBGs led to interesting inhibition profiles, although with an efficacy generally reduced when compared to the sulphonamide. The nature of the ZBG also influenced the CA inhibition mechanism. Most of these derivatives were zinc binders, but some of them (sulfonates, carboxylates) may interact with the enzyme by anchoring to the zinc-coordinated water molecule or by other inhibition mechanisms (occlusion of the active site entrance, out of the active site binding, etc.). Exploring structurally diverse ZBGs may lead to interesting new developments in the field of CAIs.

  4. 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.

  5. 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.

  6. Flexible one-dimensional carbon-selenium composite nanofibers with superior electrochemical performance for Li-Se/Na-Se batteries

    Science.gov (United States)

    Zeng, Linchao; Wei, Xiang; Wang, Jiaqing; Jiang, Yu; Li, Weihan; Yu, Yan

    2015-05-01

    A facile strategy is developed to synthesis selenium/carbon composites (Se@CNFs-CNT) by co-heating Se powder and electrospun Polyacrylonitrile (PAN)-CNT nanofibers at 600°Cin a sealed vessel. The Se molecules are chemically bonded and physical encapsulated by carbonized PAN-CNT composite (CNFs-CNT), which leads to prevent the dissolution of polyselenide intermediates in carbonate based electrolyte. When directly used as flexible free-standing cathode material for Li-Se batteries in low cost carbonate-based electrolyte, the Se@CNFs-CNT electrode exhibits improved cyclability (517 mAh g-1 after 500 cycles at 0.5 A g-1) and rate capability (485 mAh g-1 at 1 A g-1). Moreover, when tested as sodium batteries, it maintains a reversible capacity of 410 mAh g-1 after 240 cycles at 0.5 A g-1. The superior electrochemical performance (especially at high rates) of Se@CNFs-CNT is attributed to synergistic effect of the additive of CNT, the well confine of Se in the CNFs-CNT matrix through chemical bonding and the 3D interconnected carbon nanofibers (CNFs). This simple yet efficient process thus provides a promising route towards fabrication of a variety of high performance flexible Li-Se and Na-Se batteries.

  7. 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

  8. Electrospinning of single wall carbon nanotube reinforced aligned fibrils and yarns

    Science.gov (United States)

    Lam, Hoa Le

    Commercial carbon fibers produced from a polyacrylonitrile (PAN) precursor have reached their performance limit. The approach in this study involves the use of single carbon nanotubes (SWNT) with an ultra-high elastic modulus of approximately ˜1 TPa and tensile strength of ˜37 GPa at a breaking strain of ˜6% to reinforce PAN. In order to translate these extraordinary properties to a higher order structure, the need for a media to carry and assemble the SWNT into continuous fibers or yarns is necessary. Effective translation of properties can only be achieved through uniform distribution of SWNT and their alignment in the fiber axis. This has been one of the major challenges since SWNTs tend to agglomerate due to high van der Waals attraction between tubes. It is the goal of this study to develop dispersion technique(s) for the SWNT and process them into aligned fibers utilizing the electrospinning process. The electrospun nanofibers were then characterized by various techniques such as ESEM, Raman microspectroscopy, HRTEM, and tensile testing. Composite nanofibers containing various contents of SWNT up to 10 wt. % with diameter ranging from 40--300 nm were successfully electrospun through varying the polymer concentration and spinning parameters. The inclusion of SWNTs and their alignment in the fiber axis were confirmed by Raman microspectroscopy, polarized Raman and HRETEM. The failure mechanism of the nanofibers was investigated by HRTEM through fiber surface fracture. A two stage rupture mechanism was observed where crazing initiates at a surface defect followed by SWNTs pulling out of the PAN matrix. Such mechanisms consume energy therefore strengthening and toughening the fibers. Mechanical drawing of the fiber prior to heat treatment induced molecular orientation resulting in oriented graphite layers in the carbonized fibers. This study has established a processing base and characterization techniques to support the design and development of SWNT

  9. Functional materials based on carbon nanotubes: Carbon nanotube actuators and noncovalent carbon nanotube modification

    Science.gov (United States)

    Fifield, Leonard S.

    Carbon nanotubes have attractive inherent properties that encourage the development of new functional materials and devices based on them. The use of single wall carbon nanotubes as electromechanical actuators takes advantage of the high mechanical strength, surface area and electrical conductivity intrinsic to these molecules. The work presented here investigates the mechanisms that have been discovered for actuation of carbon nanotube paper: electrostatic, quantum chemical charge injection, pneumatic and viscoelastic. A home-built apparatus for the measurement of actuation strain is developed and utilized in the investigation. An optical fiber switch, the first demonstrated macro-scale device based on the actuation of carbon nanotubes, is described and its performance evaluated. Also presented here is a new general process designed to modify the surface of carbon nanotubes in a non-covalent, non-destructive way. This method can be used to impart new functionalities to carbon nanotube samples for a variety of applications including sensing, solar energy conversion and chemical separation. The process described involves the achievement of large degrees of graphitic surface coverage with polycyclic aromatic hydrocarbons through the use of supercritical fluids. These molecules are bifunctional agents that anchor a desired chemical group to the aromatic surface of the carbon nanotubes without adversely disrupting the conjugated backbone that gives rise the attractive electronic and physical properties of the nanotubes. Both the nanotube functionalization work and the actuator work presented here emphasize how an understanding and control of nanoscale structure and phenomena can be of vital importance in achieving desired performance for active materials. Opportunities for new devices with improved function over current state-of-the-art can be envisioned and anticipated based on this understanding and control.

  10. Preparation and photocatalytic performance of Fe (III)-amidoximated PAN fiber complex for oxidative degradation of azo dye under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yongchun, E-mail: dye@tjpu.edu.cn [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou, 350002 (China); Han, Zhenbang [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); Liu, Chunyan [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou, 350002 (China); Du, Fang [Division of Textile Chemistry and Ecology, School of Textile Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China)

    2010-04-15

    Polyacrylonitrile (PAN) fiber was modified with hydroxylamine hydrochloride to introduce amidoxime groups onto the fiber surface. These amidoxime groups were used to react with Fe (III) ions to prepare Fe (III)-amidoximated PAN fiber complex, which was characterized using SEM, XRD, FTIR, XPS, DMA, and DRS respectively. Then the photocatalytic activity of Fe-AO-PAN was evaluated in the degradation of a typical azo dye, C. I. Reactive Red 195 in the presence of H{sub 2}O{sub 2} under visible light irradiation. Moreover, the effect of the Fe content of Fe-AO-PAN on dye degradation was also investigated. The results indicated that Fe (III) ions can crosslink between the modified PAN fiber chains by the coordination of Fe (III) ions with the amino nitrogen atoms and hydroxyl oxygen atoms of the amidoximation groups to form Fe (III)-amidoximated PAN fiber complex, and the Fe content of which is mainly determined by Fe (III) ions and amidoximation groups. Fe (III)-amidoximated PAN fiber complex is found to be activated in the visible light region. Moreover, Fe (III)-amidoximated PAN fiber complex shows the catalytic activity for dye degradation by H{sub 2}O{sub 2} at pH = 6.0 in the dark, and can be significantly enhanced by increasing light irradiation and Fe content, therefore, it can be used as a new heterogeneous Fenton photocatalyst for the effective decomposition of the dye in water. In addition, ESR spectra confirm that Fe (III)-amidoximated PAN fiber complex can generate more {center_dot}OH radicals from H{sub 2}O{sub 2} under visible light irradiation, leading to dye degradation. A possible mechanism of photocatalysis is proposed.

  11. Spent coffee grounds-based activated carbon preparation for sequestering of malachite green

    Science.gov (United States)

    Lim, Jun-Wei; Lam, Keat-Ying; Bashir, Mohammed J. K.; Yeong, Yin-Fong; Lam, Man-Kee; Ho, Yeek-Chia

    2016-11-01

    The key of reported work was to optimize the fabricating factors of spent coffee grounds-based activated carbon (SCG-bAC) used to sequester Malachite Green (MG) form aqueous solution via adsorption process. The fabricating factors of impregnation ratio with ortho-phosphoric acid, activation temperature and activation time were simultaneously optimized by central composite design (CCD) of response surface methodology (RSM) targeting on maximum removal of MG. At the optimum condition, 96.3% of MG was successfully removed by SCG-bAC at the impregnation ratio with ortho-phosphoric acid of 0.50, activation temperature of 554°C and activation time of 31.4 min. Statistical model that could predict the MG removal percentage was also derived and had been statistically confirmed to be significant. Subsequently, the MG adsorption equilibrium data was found well-fitted to Langmuir isotherm model, indicating the predominance of monolayer adsorption of MG on SCG-bAC surface. To conclude, the findings from the this study unveil the potential of spent coffee grounds as an alternative precursor in fabricating low-cost AC for the treatment of wastewater loaded with MG pollutant.

  12. Improvements for PanDA and intermediate layers

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Gen; Magradze, Erekle; Musheghyan, Haykuhi; Nadal, Jordi; Quadt, Arnulf; Rzehorz, Gerhard [II. Physikalisches Institut, Georg-August-Universitaet Goettingen (Germany)

    2015-07-01

    The PanDA Production and Distributed Analysis system is handling the ATLAS workload management for production and distributed analysis processing. It was designed for analysis as well as production for High Energy Physics. One of the advantages of this pilot based system is, that it has its own integrated monitoring solution. Monitoring is a method used in computing, it means that a certain process is observed and overseen and is usually also protocolled. In the case of a process or system failure, a responsible person should be notified and countermeasures taken. Since PanDA is very versatile, it can also be used to process jobs on a computing Cloud, instead of just using the Grid(WLCG). Cloud computing resources can be provided by private companies, that bill the resources that are actually being used, for example CPU power over time. The advantage of this is obvious if one looks at the cost. They are basically the same, whether a huge task is done on little CPU power over a long time or on plenty of CPU power in a short time. For these reasons, a close monitoring, for example by the PanDA system for the usage of Cloud resources is important.

  13. Development and characterization of highly oriented PAN nanofiber

    Directory of Open Access Journals (Sweden)

    M. Sadrjahani

    2010-12-01

    Full Text Available A simple and non-conventional electrospinning technique was employed for producing highly oriented Polyacrylonitrile (PAN nanofibers. The PAN nanofibers were electrospun from 14 wt% solution of PAN in dimethylformamid (DMF at 11 kv on a rotating drum with various linear speeds from 22.5 m/min to 67.7 m/min. The influence of take up velocity was investigated on the degree of alignment, internal structure and mechanical properties of collected PAN nanofibers. Using an image processing technique, the best degree of alignment was obtained for those nanofibers collected at a take up velocity of 59.5 m/min. Moreover, Raman spectroscopy was used for measuring molecular orientation of PAN nanofibers. Similarly, a maximum chain orientation parameter of 0.25 was determined for nanofibers collected at a take up velocity of 59.5 m/min.

  14. Peroxyacetyl nitrate (PAN and peroxyacetic acid (PAA measurements by iodide chemical ionisation mass spectrometry: first analysis of results in the boreal forest and implications for the measurement of PAN fluxes

    Directory of Open Access Journals (Sweden)

    G. J. Phillips

    2013-02-01

    Full Text Available We describe measurements of peroxyacetyl nitrate (CH3C(OO2NO2, PAN and peroxyacetic acid (CH3C(OOOH, PAA in the Boreal forest using iodide chemical ionization mass spectrometry (ICIMS. The measurements were made during the Hyytiälä United Measurement of Photochemistry and Particles – Comprehensive Organic Particle and Environmental Chemistry (HUMPPA-COPEC-2010 measurement intensive. Mixing ratios of PAN and PAA were determined by measuring the acetate ion signal (CH3C(OO, m/z = 59 resulting from reaction of CH3C(OO2 (from the thermal dissociation of PAN or CH3C(OOOH with iodide ions using alternatively heated and ambient temperature inlet lines. During some periods of high temperature (~ 30 °C and low NOx (< 1 ppbv, PAA mixing ratios were similar to, or exceeded those of PAN and thus contributed a significant fraction of the total acetate signal. PAA is thus a potential interference for ICIMS measurements of PAN, and especially eddy covariance flux measurements in environments where the PAA flux is likely to be a significant proportion of the (short timescale acetate ion variability. Within the range of mixing ratios of NOx measured during HUMPPA-COPEC, the modelled ratio of PAA-to-PAN was found to be sensitive to temperature (through the thermal decomposition rate of PAN and the HO2 mixing ratio, thus providing some constraint to estimates of photochemical activity and oxidation rates in the Boreal environment.

  15. Theromdynamics of carbon in nickel-based multicomponent solid solutions

    International Nuclear Information System (INIS)

    Bradley, D.J.

    1978-04-01

    The activity coefficient of carbon in nickel, nickel-titanium, nickel-titanium-chromium, nickel-titanium-molybdenum and nickel-titanium-molybdenum-chromium alloys has been measured at 900, 1100 and 1215 0 C. The results indicate that carbon obeys Henry's Law over the range studied (0 to 2 at. percent). The literature for the nickel-carbon and iron-carbon systems are reviewed and corrected. For the activity of carbon in iron as a function of composition, a new relationship based on re-evaluation of the thermodynamics of the CO/CO 2 equilibrium is proposed. Calculations using this relationship reproduce the data to within 2.5 percent, but the accuracy of the calibrating standards used by many investigators to analyze for carbon is at best 5 percent. This explains the lack of agreement between the many precise sets of data. The values of the activity coefficient of carbon in the various solid solutions are used to calculate a set of parameters for the Kohler-Kaufman equation. The calculations indicate that binary interaction energies are not sufficient to describe the thermodynamics of carbon in some of the nickel-based solid solutions. The results of previous workers for carbon in nickel-iron alloys are completely described by inclusion of ternary terms in the Kohler-Kaufman equation. Most of the carbon solid solution at high temperatures in nickel and nickel-titantium alloys precipitates from solution on quenching in water. The precipitate is composed of very small particles (greater than 2.5 nm) of elemental carbon. The results of some preliminary thermomigration experiments are discussed and recommendations for further work are presented

  16. Guided Image Filtering-Based Pan-Sharpening Method: A Case Study of GaoFen-2 Imagery

    Directory of Open Access Journals (Sweden)

    Yalan Zheng

    2017-12-01

    Full Text Available GaoFen-2 (GF-2 is a civilian optical satellite self-developed by China equipped with both multispectral and panchromatic sensors, and is the first satellite in China with a resolution below 1 m. Because the pan-sharpening methods on GF-2 imagery have not been a focus of previous works, we propose a novel pan-sharpening method based on guided image filtering and compare the performance to state-of-the-art methods on GF-2 images. Guided image filtering was introduced to decompose and transfer the details and structures from the original panchromatic and multispectral bands. Thereafter, an adaptive model that considers the local spectral relationship was designed to properly inject spatial information back into the original spectral bands. Four pairs of GF-2 images acquired from urban, water body, cropland, and forest areas were selected for the experiments. Both quantitative and visual inspections were used for the assessment. The experimental results demonstrated that for GF-2 imagery acquired over different scenes, the proposed approach consistently achieves high spectral fidelity and enhances spatial details, thereby benefitting the potential classification procedures.

  17. Supporting of some ferrocyanides on polyacrylonitrile (PAN) binding polymer and their application for cesium treatment

    International Nuclear Information System (INIS)

    Someda, H.H.; El Zahhar, A.A.; Shehata, M.K.; El-Naggar, H.A.

    2001-01-01

    Transition metal ferrocyanides were supported on polyacrylonitrile (PAN) as a binding polymer and were used for removal of radiocesium. The sorption capacity were determined for each sorbent and was found to be 1.22 and 0.65 meq/gm for KZnHCF-PAN and KCuHCF-PAN respectively. Different parameters affecting the sorption process were studied as chemical nature of the active solution, presence of competing ions and flow rate of feed solution. The regeneration of the used sorbent was studied using different solutions and also reusing the regenerated sorbent in other cycle up to four cycles (authors)

  18. 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.

  19. Targeting the HER family with Pan-HER effectively overcomes resistance to cetuximab

    Science.gov (United States)

    Iida, Mari; Bahrar, Harsh; Brand, Toni M; Pearson, Hannah E; Coan, John P; Orbuch, Rachel A; Flanigan, Bailey G; Swick, Adam D; Prabakaran, Prashanth; Lantto, Johan; Horak, Ivan D.; Kragh, Michael; Salgia, Ravi; Kimple, Randy J; Wheeler, Deric L

    2016-01-01

    Cetuximab, an antibody against the Epidermal Growth Factor Receptor (EGFR) has shown efficacy in treating head and neck squamous cell carcinoma (HNSCC), metastatic colorectal cancer and non-small cell lung cancer (NSCLC). Despite the clinical success of cetuximab, many patients do not respond to cetuximab. Furthermore, virtually all patients who do initially respond become refractory, highlighting both intrinsic and acquired resistance to cetuximab as significant clinical problems. To understand mechanistically how cancerous cells acquire resistance, we previously developed models of acquired resistance using the H226 NSCLC and UM-SCC1 HNSCC cell lines. Cetuximab-resistant clones showed a robust upregulation and dependency on the HER family receptors EGFR, HER2 and HER3. Here, we examined Pan-HER, a mixture of six antibodies targeting these receptors on cetuximab-resistant clones. In cells exhibiting acquired or intrinsic resistance to cetuximab, Pan-HER treatment decreased all three receptors’ protein levels and down-stream activation of AKT and MAPK. This correlated with decreased cell proliferation in cetuximab-resistant clones. To determine whether Pan-HER had a therapeutic benefit in vivo, we established de novo cetuximab-resistant mouse xenografts and treated resistant tumors with Pan-HER. This regimen resulted in a superior growth delay of cetuximab-resistant xenografts compared to mice continued on cetuximab. Furthermore, intrinsically cetuximab-resistant HNSCC patient-derived xenograft tumors treated with Pan-HER exhibited significant growth delay compared to vehicle/cetuximab controls. These results suggest that targeting HER family receptors simultaneously with Pan-HER is a promising treatment strategy for tumors displaying intrinsic or acquired resistance to cetuximab. PMID:27422810

  20. Synthesis and characterization of carbon nanotube from coconut shells activated carbon

    Science.gov (United States)

    Melati, A.; Hidayati, E.

    2016-03-01

    Carbon nanotubes (CNTs) have been explored in almost every single cancer treatment modality, including drug delivery, lymphatic targeted chemotherapy, photodynamic therapy, and gene therapy. They are considered as one of the most promising nanomaterial with the capability of both detecting the cancerous cells and delivering drugs or small therapeutic molecules to the cells. CNTs have unique physical and chemical properties such as high aspect ratio, ultralight weight, high mechanical strength, high electrical conductivity, and high thermal conductivity. Coconut Shell was researched as active carbon source on 500 - 600°C. These activated carbon was synthesized becomes carbon nanotube and have been proposed as a promising tool for detecting the expression of indicative biological molecules at early stage of cancer. Clinically, biomarkers cancer can be detected by CNT Biosensor. We are using pyrolysis methods combined with CVD process or Wet Chemical Process on 600°C. Our team has successfully obtained high purity, and aligned MWCNT (Multi Wall Nanotube) bundles on synthesis CNT based on coconut shells raw materials. CNTs can be used to cross the mammalian cell membrane by endocytosis or other mechanisms. SEM characterization of these materials have 179 nm bundles on phase 83° and their materials compound known by using FTIR characterization.

  1. Pan Am tar sand bid revealed

    Energy Technology Data Exchange (ETDEWEB)

    Gray, E

    1968-12-16

    Muskeg Oil Co., wholly-owned subsidiary of Pan American Canada Oil Co. Ltd., hopes to expand its proposed initial 8,000 bpd in situ Athabasca tar sand production scheme to an ultimate rate of 60,000 bpd. The Muskeg recovery process involves an in situ combustion technique developed by Pan American and applied successfully in experimental work in the Athabasca area. The underground burning process develops heat in the formation, reduces crude bitumen viscosity, and displaces the bitumen to the producing wells. Core analyses have been used to determine bitumen in place, wherever possible. Values for uncored wells were based on logs, through development of an empirical relationship between formation resistivity measured by focused logging devices and bitumen content determined by core analysis. The proposed recovery process is a 10-acre well spacing with 9-spot configuration. The McMurray Formation will be fractured hydraulically and preheated by a combustion process. The bitumen will be recovered by a combustion displacement process utilizing air and water.

  2. Eddy covariance fluxes of acyl peroxy nitrates (PAN, PPN and MPAN above a Ponderosa pine forest

    Directory of Open Access Journals (Sweden)

    G. M. Wolfe

    2009-01-01

    Full Text Available During the Biosphere Effects on AeRosols and Photochemistry EXperiment 2007 (BEARPEX-2007, we observed eddy covariance (EC fluxes of speciated acyl peroxy nitrates (APNs, including peroxyacetyl nitrate (PAN, peroxypropionyl nitrate (PPN and peroxymethacryloyl nitrate (MPAN, above a Ponderosa pine forest in the western Sierra Nevada. All APN fluxes are net downward during the day, with a median midday PAN exchange velocity of −0.3 cm s−1; nighttime storage-corrected APN EC fluxes are smaller than daytime fluxes but still downward. Analysis with a standard resistance model shows that loss of PAN to the canopy is not controlled by turbulent or molecular diffusion. Stomatal uptake can account for 25 to 50% of the observed downward PAN flux. Vertical gradients in the PAN thermal decomposition (TD rate explain a similar fraction of the flux, suggesting that a significant portion of the PAN flux into the forest results from chemical processes in the canopy. The remaining "unidentified" portion of the net PAN flux (~15% is ascribed to deposition or reactive uptake on non-stomatal surfaces (e.g. leaf cuticles or soil. Shifts in temperature, moisture and ecosystem activity during the summer – fall transition alter the relative contribution of stomatal uptake, non-stomatal uptake and thermochemical gradients to the net PAN flux. Daytime PAN and MPAN exchange velocities are a factor of 3 smaller than those of PPN during the first two weeks of the measurement period, consistent with strong intra-canopy chemical production of PAN and MPAN during this period. Depositional loss of APNs can be 3–21% of the gross gas-phase TD loss depending on temperature. As a source of nitrogen to the biosphere, PAN deposition represents approximately 4–19% of that due to dry deposition of nitric acid at this site.

  3. Localization and regulation of mouse pantothenate kinase 2 [The PanK2 Genes of Mouse and Human Specify Proteins with Distinct Subcellular Locations

    Energy Technology Data Exchange (ETDEWEB)

    Leonardi, Roberta [St. Jude Children' s Research Hospital, Memphis, TN (United States); Zhang, Yong-Mei [St. Jude Children' s Research Hospital, Memphis, TN (United States); Lykidis, Athanasios [DOE Joint Genome Inst., Walnut Creek, CA (United States); Rock, Charles O. [St. Jude Children' s Research Hospital, Memphis, TN (United States); Jackowski, Suzanne [St. Jude Children' s Research Hospital, Memphis, TN (United States)

    2007-09-07

    Coenzyme A (CoA) biosynthesis is initiated by pantothenatekinase (PanK) and CoA levels are controlled through differentialexpression and feedback regulation of PanK isoforms. PanK2 is amitochondrial protein in humans, but comparative genomics revealed thatacquisition of a mitochondrial targeting signal was limited to primates.Human and mouse PanK2 possessed similar biochemical properties, withinhibition by acetylCoA and activation by palmitoylcarnitine. Mouse PanK2localized in the cytosol, and the expression of PanK2 was higher in humanbrain compared to mouse brain. Differences in expression and subcellularlocalization should be considered in developing a mouse model for humanPanK2 deficiency.

  4. Microstructure and mechanical properties of carbon fiber reinforced ...

    Indian Academy of Sciences (India)

    68

    Alumina; composites; carbon fiber reinforcement; sol; mechanical properties. 1. Introduction ... The reinforcement was 3D carbon fiber (T300 3k, ex-PAN carbon fiber ... where f(a/H) = 2.9(a/H)1/2 – 4.6(a/H)3/2 + 21.8(a/H)5/2. – 37.6(a/H)7/2 + ...

  5. 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.

  6. Migration of ATLAS PanDA to CERN

    International Nuclear Information System (INIS)

    Stewart, Graeme Andrew; Klimentov, Alexei; Maeno, Tadashi; Nevski, Pavel; Nowak, Marcin; De Castro Faria Salgado, Pedro Emanuel; Wenaus, Torre; Koblitz, Birger; Lamanna, Massimo

    2010-01-01

    The ATLAS Production and Distributed Analysis System (PanDA) is a key component of the ATLAS distributed computing infrastructure. All ATLAS production jobs, and a substantial amount of user and group analysis jobs, pass through the PanDA system, which manages their execution on the grid. PanDA also plays a key role in production task definition and the data set replication request system. PanDA has recently been migrated from Brookhaven National Laboratory (BNL) to the European Organization for Nuclear Research (CERN), a process we describe here. We discuss how the new infrastructure for PanDA, which relies heavily on services provided by CERN IT, was introduced in order to make the service as reliable as possible and to allow it to be scaled to ATLAS's increasing need for distributed computing. The migration involved changing the backend database for PanDA from MySQL to Oracle, which impacted upon the database schemas. The process by which the client code was optimised for the new database backend is discussed. We describe the procedure by which the new database infrastructure was tested and commissioned for production use. Operations during the migration had to be planned carefully to minimise disruption to ongoing ATLAS offline computing. All parts of the migration were fully tested before commissioning the new infrastructure and the gradual migration of computing resources to the new system allowed any problems of scaling to be addressed.

  7. Effect of Activation Temperature on CO{sub 2} Capture Behaviors of Resorcinol-based Carbon Aerogels

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Cheolwhan; Im, Seungsoon; Park, Soojin [Hanyang Univ., Seoul (Korea, Republic of); Kim, Youngjoo [Inha Univ., Incheon (Korea, Republic of)

    2014-01-15

    In this study, carbon aerogel (CA) was synthesized using a soft-template method, and the optimum conditions for the adsorption of carbon dioxide (CO{sub 2}) by the carbon aerogel were evaluated by controlling the activation temperature. KOH was used as the activation agent at a KOH/CA activation ratio of 4:1. Three types of activated CAs were synthesized at activation temperatures of 800 .deg. C (CA-K-800), 900 .deg. C (CA-K-900), and 1000 .deg. C (CA-K-1000), and their surface and pore characteristics along with the CO{sub 2} adsorption characteristics were examined. The results showed that with the increase in activation temperature from 800 to 900 .deg. C, the total pore volume and specific surface area sharply increased from 1.2165 to 1.2500 cm{sup 3}/g and 1281 to 1526 m{sup 2}/g, respectively. However, the values for both these parameters decreased at temperatures above 1000 .deg. C. The best CO{sub 2} adsorption capacity of 10.9 wt % was obtained for the CA-K-900 sample at 298 K and 1 bar. This result highlights the importance of the structural and textural characteristics of the carbon aerogel, prepared at different activation temperatures on CO{sub 2} adsorption behaviors.

  8. A thermodynamic approach to assess organic solute adsorption onto activated carbon in water

    KAUST Repository

    De Ridder, David J.; Verliefde, Arne R. D.; Heijman, Bas G J; Gelin, Simon; Pereira, Manuel Fernando Ribeiro; Rocha, Raquel P.; Figueiredo, José Luí s M; Amy, Gary L.; Van Dijk, Hans C.

    2012-01-01

    In this paper, the hydrophobicity of 13 activated carbons is determined by various methods; water vapour adsorption, immersion calorimetry, and contact angle measurements. The quantity and type of oxygen-containing groups on the activated carbon were measured and related to the methods used to measure hydrophobicity. It was found that the water-activated carbon adsorption strength (based on immersion calorimetry, contact angles) depended on both type and quantity of oxygen-containing groups, while water vapour adsorption depended only on their quantity. Activated carbon hydrophobicity measurements alone could not be related to 1-hexanol and 1,3-dichloropropene adsorption. However, a relationship was found between work of adhesion and adsorption of these solutes. The work of adhesion depends not only on activated carbon-water interaction (carbon hydrophobicity), but also on solute-water (solute hydrophobicity) and activated carbon-solute interactions. Our research shows that the work of adhesion can explain solute adsorption and includes the effect of hydrogen bond formation between solute and activated carbon. © 2012 Elsevier Ltd. All rights reserved.

  9. A thermodynamic approach to assess organic solute adsorption onto activated carbon in water

    KAUST Repository

    De Ridder, David J.

    2012-08-01

    In this paper, the hydrophobicity of 13 activated carbons is determined by various methods; water vapour adsorption, immersion calorimetry, and contact angle measurements. The quantity and type of oxygen-containing groups on the activated carbon were measured and related to the methods used to measure hydrophobicity. It was found that the water-activated carbon adsorption strength (based on immersion calorimetry, contact angles) depended on both type and quantity of oxygen-containing groups, while water vapour adsorption depended only on their quantity. Activated carbon hydrophobicity measurements alone could not be related to 1-hexanol and 1,3-dichloropropene adsorption. However, a relationship was found between work of adhesion and adsorption of these solutes. The work of adhesion depends not only on activated carbon-water interaction (carbon hydrophobicity), but also on solute-water (solute hydrophobicity) and activated carbon-solute interactions. Our research shows that the work of adhesion can explain solute adsorption and includes the effect of hydrogen bond formation between solute and activated carbon. © 2012 Elsevier Ltd. All rights reserved.

  10. Simplified pilot module development and testing within the ATLAS PanDA Pilot 2.0 Project

    CERN Document Server

    Drizhuk, Daniil; The ATLAS collaboration; Nilsson, Paul

    2016-01-01

    The Production and Distributed Analysis (PanDA) system has been developed to meet ATLAS production and analysis requirements for a data-driven workload management system capable of operating at the LHC data processing scale. The PanDA pilot is one of the major components in the PanDA system. It runs on a worker node and takes care of setting up the environment, fetching and pushing data to storage, getting jobs from the PanDA server and executing them. The original PanDA Pilot was designed over 10 years ago and has since then grown organically. Large parts of the original pilot code base are now getting old and are difficult to maintain. Incremental changes and refactoring have been pushed to the limit, and the time is now right for a fresh start, informed by a decade of experience, with the PanDA Pilot 2.0 Project. To create a testing environment for module development and automated unit and functional testing for next generation pilot tasks, a simple pilot version was developed. It resembles the basic workf...

  11. Stimulation of sulfate-reducing activity at salt-saturation in the salterns of Ribandar, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Kerkar, S.; LokaBharathi, P.A.

    salt pan. Each pans is surrounded by ?bandhs? or mud borders on all four sides to prevent siltation and help regulate the flow of water. In the Ribandar saltern, sea water from the Mandovi estuary enters the creek through a sluice gate at high tide... activity (SRA) in marine ecosystems, especially the coastal regions contributes as much as 50% organic carbon turnover (Jorgensen,1982). Sulphate accounts for 70 - 90% of total respiration in salt marsh sediments, where total sediment respiration rates...

  12. Micro supercapacitors based on a 3D structure with symmetric graphene or activated carbon electrodes

    Science.gov (United States)

    Li, Siwei; Wang, Xiaohong; Xing, Hexin; Shen, Caiwei

    2013-11-01

    This paper presents three-dimensional (3D) micro supercapacitors with thick interdigital electrodes supported and separated by SU-8. Nanoporous carbon materials including graphene and activated carbon (AC) are used as active materials in self-supporting composites to build the electrodes. The SU-8 separators provide mechanical support for thick electrodes and allow a considerable amount of material to be loaded in a limited footprint area. The prototypes have been accomplished by a simple microelectromechanical systems (MEMS) fabrication process and sealed by polydimethylsiloxane (PDMS) caps with ionic liquid electrolytes injected into the electrode area. Electrochemical tests demonstrate that the graphene-based prototype with 100 µm thick electrodes shows good power performance and provides a considerable specific capacitance of about 60 mF cm-2. Two AC-based prototypes show larger capacitance of 160 mF cm-2 and 311 mF cm-2 with 100 µm and 200 µm thick electrodes respectively, because of higher volume density of the material. The results demonstrate that both thick 3D electrode structure and volume capacitance of the electrode material are key factors for high-performance micro supercapacitors, which can be potentially used in specific applications such as power suppliers and storage components for harvesters.

  13. Fabrication of carbon layer coated FE-nanoparticles using an electron beam irradiation

    Science.gov (United States)

    Kim, Hyun Bin; Jeun, Joon Pyo; Kang, Phil Hyun; Oh, Seung-Hwan

    2016-01-01

    A novel synthesis of carbon encapsulated Fe nanoparticles was developed in this study. Fe chloride (III) and polyacrylonitrile (PAN) were used as precursors. The crosslinking of PAN molecules and the nucleation of Fe nanoparticles were controlled by the electron beam irradiation dose. Stabilization and carbonization processes were carried out using a vacuum furnace at 275 °C and 1000 °C, respectively. Micro structures were evaluated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fe nanoparticles were formed with diameters of 100 nm, and the Fe nanoparticles were encapsulated by carbon layers. As the electron beam irradiation dose increased, it was observed that the particle sizes decreased.

  14. Preparing activated carbon from charcoal and investigation of the selective uranium adsorption

    International Nuclear Information System (INIS)

    Kuetahyali, C.; Eral, M.

    2001-01-01

    Preconcentration and separation procedures based on adsorption phenomena are important in nuclear and especially radiation chemistry, industry, medicine and daily life. Adsorption of uranium onto various solids is important from purification, environmental and radioactive waste disposal points of view . The treatment of aqueous nuclear waste solutions containing soluble metal ions requires concentration of the metal ions into smaller volume followed by recovery or secure disposal. For this purpose, many processes are being utilized such as precipitation, ion-exchange, solvent extraction and adsorption on solids etc. Interest in the adsorption of metal ions for recovery purposes has increased manyfold in recent years, because of its simplicity, selectivity and efficiency . The main advantage of adsorption is the separation of trace amount of elements from large volumes of solutions. In recent years, several studies have been made to recover radionuclides by adsorption using natural and synthetic adsorbents. Adsorption on charcoal is one of the most efficient techniques used in water treatment processes for the removal of organics and micropollutants from wastes and drinking waters. Adsorption processes have long been used in the removal of color, odor, and organic pollution. These processes are usually based on the use of activated carbon . Activated carbon consists mainly of carbon and is produced from every carbonaceous material. Activated carbon characterized by its high surface area and its wide distribution of porosity. The textural properties (surface area and porosity) of activated carbons play an important role in determining the capacity of the material in adsorption from aqueous solution. Chemistry of the surface is also important . Generally, activated carbons are mainly microporous, but in addition to micropores they contain meso- and macropores, which are very important in facilitating acces of the adsorbate molecules to the interior of carbon particles

  15. 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)

  16. Activated carbon as a pseudo-reference electrode for electrochemical measurement inside concrete

    NARCIS (Netherlands)

    Abbas, Yawar; Olthuis, Wouter; van den Berg, Albert

    2015-01-01

    The application of Kynol based activated carbon (KAC) as a pseudo-reference electrode for potentiometric measurement inside concrete is presented. Due to its high surface area the activated carbons has a large electrical double layer capacitance (EDLC > 50 F g(-1)) and are used as electrode material

  17. Production of activated carbon from Victorian brown coal and its application in gold recovery

    Energy Technology Data Exchange (ETDEWEB)

    Jobson, G.; Swinbourne, D.

    1985-01-01

    A research grant was awarded by the Coal Council of Victoria to support investigations into the manufacture of a Victorian brown coal-based activated carbon suitable for Carbon-in-Pulp (CIP) gold recovery operations. This project was started on 31.1.84 and was completed by 27.9.85. The general aim of this study was to develop the technology needed for production of an indigenous activated carbon which could be a substitute for the carbons presently imported for use in CIP operations. There was a considerable economic incentive to achieve a carbon based on an inexpensive resource such as Victorian brown coal.

  18. Method for separation of uranium hexafluoride by specially activated carbons

    International Nuclear Information System (INIS)

    Bannasch, W.

    1976-01-01

    The present invention deals with the separation of urainium hexafluoride from gas streams on special activated carbon which can be released during an accident in nuclear plants. Those plants are concerned here in which as a rule uranium hexafluoride is handled in liquid aggregate state. The patent claims deal with the adsorption of UF 6 from gas mixtures in the temperature region of 70-200 0 C and the application of UF 6 adsorbing activated carbon of a certain grain based on petroleum and/or weight % and with a asch content of 4 to 6 weigt % and with a benzol yield of 50-60g benzene /100g activated carbon. (GG) [de

  19. Multi-Column Xe/Kr Separation with AgZ-PAN and HZ-PAN

    International Nuclear Information System (INIS)

    Greenhalgh, Mitchell Randy; Garn, Troy Gerry; Welty, Amy Keil; Watson, Tony Leroy

    2016-01-01

    Previous multi-column xenon/krypton separation tests have demonstrated the capability of separating xenon from krypton in a mixed gas feed stream. The results of this initial testing with AgZ-PAN and HZ-PAN indicated that an excellent separation of xenon from krypton could be achieved. Building upon these initial results, a series of additional multi-column testing were performed in FY-16. The purpose of this testing was to scale up the sorbent beds, test a different composition of feed gas and attempt to improve the accuracy of the analysis of the individual capture columns' compositions. Two Stirling coolers were installed in series to perform this testing. The use of the coolers instead of the cryostat provided two desired improvements, 1) removal of the large dilution due to the internal volume of the cryostat adsorption chamber, and 2) ability to increase the sorbent bed size for scale-up. The AgZ-PAN sorbent, due to its xenon selectivity, was loaded in the first column to capture the xenon while allowing the krypton to flow through and be routed to a second column containing the HZ-PAN for capture and analysis. The gases captured on both columns were sampled with evacuated sample bombs and subsequently analyzed via GC-MS for both krypton and xenon. The results of these tests can be used to develop the scope of future testing and analysis using this test bed for demonstrating the capture and separation of xenon and krypton using sorbents, for demonstrating desorption and regeneration of the sorbents, and for determining compositions of the desorbed gases. They indicate a need for future desorption studies in order to better quantify co-adsorbed species and final krypton purity.

  20. Multi-Column Xe/Kr Separation with AgZ-PAN and HZ-PAN

    Energy Technology Data Exchange (ETDEWEB)

    Greenhalgh, Mitchell Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Garn, Troy Gerry [Idaho National Lab. (INL), Idaho Falls, ID (United States); Welty, Amy Keil [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    Previous multi-column xenon/krypton separation tests have demonstrated the capability of separating xenon from krypton in a mixed gas feed stream. The results of this initial testing with AgZ-PAN and HZ-PAN indicated that an excellent separation of xenon from krypton could be achieved. Building upon these initial results, a series of additional multi-column testing were performed in FY-16. The purpose of this testing was to scale up the sorbent beds, test a different composition of feed gas and attempt to improve the accuracy of the analysis of the individual capture columns’ compositions. Two Stirling coolers were installed in series to perform this testing. The use of the coolers instead of the cryostat provided two desired improvements, 1) removal of the large dilution due to the internal volume of the cryostat adsorption chamber, and 2) ability to increase the sorbent bed size for scale-up. The AgZ-PAN sorbent, due to its xenon selectivity, was loaded in the first column to capture the xenon while allowing the krypton to flow through and be routed to a second column containing the HZ-PAN for capture and analysis. The gases captured on both columns were sampled with evacuated sample bombs and subsequently analyzed via GC-MS for both krypton and xenon. The results of these tests can be used to develop the scope of future testing and analysis using this test bed for demonstrating the capture and separation of xenon and krypton using sorbents, for demonstrating desorption and regeneration of the sorbents, and for determining compositions of the desorbed gases. They indicate a need for future desorption studies in order to better quantify co-adsorbed species and final krypton purity.

  1. Activation of magnesium rich minerals as carbonation feedstock materials for CO2 sequestration

    International Nuclear Information System (INIS)

    Maroto-Valer, M.M.; Kuchta, M.E.; Zhang, Y.; Andresen, J.M.; Fauth, D.J.

    2005-01-01

    Mineral carbonation, the reaction of magnesium-rich minerals such as olivine and serpentine with CO 2 to form stable mineral carbonates, is a novel and promising approach to carbon sequestration. However, the preparation of the minerals prior to carbonation can be energy intensive, where some current studies have been exploring extensive pulverization of the minerals below 37 μm, heat treatment of minerals up to 650 o C, prior separation of CO 2 from flue gases, and carbonation at high pressures, temperatures and long reaction times of up to 125 atm, 185 o C and 6 h, respectively. Thus, the objective of the mineral activation concept is to promote and accelerate carbonation reaction rates and efficiencies through surface activation to the extent that such rigorous reaction conditions were not required. The physical activations were performed with air and steam, while chemical activations were performed with a suite of acids and bases. The parent serpentine, activated serpentines, and carbonation products were characterized to determine their surface properties and assess their potential as carbonation minerals. The results indicate that the surface area of the raw serpentine, which is approximately 8 m 2 /g, can be increased through physical and chemical activation methods to over 330 m 2 /g. The chemical activations were more effective than the physical activations at increasing the surface area, with the 650 o C steam activated serpentine presenting a surface area of only 17 m 2 /g. Sulfuric acid was the most effective acid used during the chemical activations, resulting in surface areas greater than 330 m 2 /g. Several of the samples produced underwent varying degrees of carbonation. The steam activated serpentine underwent a 60% conversion to magnesite at 155 o C and 126 atm in 1 h, while the parent sample only exhibited a 7% conversion. The most promising results came from the carbonation of the extracted Mg(OH) 2 solution, where, based on the amount of

  2. Characterization of water commercial filters based on activated carbon for water treatment of the Tumbes river – Peru

    Directory of Open Access Journals (Sweden)

    Carmen Rosa Silupú García

    2017-09-01

    Full Text Available Comercial activated carbon samples (A, B, C, and D used in filters for the treatment of water were characterized and evaluated in the decontamination of heavy metals present in river water and in the elimination of coliform microorganisms. The carbon samples had microporous and mesoporous structures. Surface areas of between 705 and 906 m2/g were found. The carbons samples were amorphous and the presence of antibacterial agents such as Ag, Cl, Cu, and Si was detected. It was determined that for As and Pb, whose initial concentrations in contaminated water (water of the Tumbes river-Peru were 56.7 and 224.0 μg/L, respectively, the percentage of adsorption was close to 100%. The relationship between point of zero charge pH of the activated carbons and pH of the river water during the experiments plays a determinant role in the adsorption of the analyzed elements. The antibacterial capacity was evaluated satisfactorily against the following strains of fecal gram negative bacteria: Escherichia coli (ATCC® 25922™, Salmonella typhimurium (ATCC® 14028™, and Shigella flexneri (ATCC® 12022™. This ability is based on the surface presence in the carbons of the mentioned antibacterial agents.

  3. The occurrence of large branchiopod crustaceans in perennial pans ...

    African Journals Online (AJOL)

    Pans are isolated, shallow depressions that are endorheic in nature. Because of the natural hydrological functioning of pans, these systems are usually restricted to arid regions and complete desiccation occurs seasonally. In the eastern provinces of South Africa many pans are perennial in nature often remaining inundated ...

  4. An electronic pan/tilt/magnify and rotate camera system

    International Nuclear Information System (INIS)

    Zimmermann, S.; Martin, H.L.

    1992-01-01

    A new camera system has been developed for omnidirectional image-viewing applications that provides pan, tilt, magnify, and rotational orientation within a hemispherical field of view (FOV) without any moving parts. The imaging device is based on the fact that the image from a fish-eye lens, which produces a circular image of an entire hemispherical FOV, can be mathematically corrected using high-speed electronic circuitry. More specifically, an incoming fish-eye image from any image acquisition source is captured in the memory of the device, a transformation is performed for the viewing region of interest and viewing direction, and a corrected image is output as a video image signal for viewing, recording, or analysis. The image transformation device can provide corrected images at frame rates compatible with RS-170 standard video equipment. As a result, this device can accomplish the functions of pan, tilt, rotation, and magnification throughout a hemispherical FOV without the need for any mechanical devices. Multiple images, each with different image magnifications and pan-tilt-rotate parameters, can be obtained from a single camera

  5. Surface chemistry of a viscose-based activated carbon cloth modified by treatment with ammonia and steam

    Energy Technology Data Exchange (ETDEWEB)

    Boudou, J.P. [University of Paris, Paris (France)

    2003-07-01

    The influence of ammonia treatment at 800{sup o}C on the catalytic activity of a viscose-based activated carbon cloth (ACC) was evaluated for the oxidative retention of H{sub 2}S or SO{sub 2} at room temperature. Change in the surface chemistry was observed by X-ray spectroscopy of nitrogen (N1s) and by temperature programmed desorption (TPD). Dynamic adsorption of H{sub 2}S or SO{sub 2} in moist air onto a packed bed of activated carbon cloth was monitored by measurement of the breakthrough curves at room temperature. ACC modified by ammonia showed noteworthy enhanced SO{sub 2} and H{sub 2}S loading relative to the untreated ACC. Improved SO{sub 2} retention rate could be replicated several times after regeneration by washing at room temperature, in contrast to the case with H{sub 2}S. The likely reasons for the behavior of H{sub 2}S and SO{sub 2} on the ammonia-treated ACC are discussed with reference to the recent literature.

  6. Studies of cryocooler based cryosorption pump with activated carbon panels operating at 11K

    International Nuclear Information System (INIS)

    Kasthurirengan, S; Behera, Upendra; Gangradey, Ranjana; Udgata, Swarup; Krishnamoorthy, V

    2012-01-01

    Cryosorption pump is the only solution for pumping helium and hydrogen in fusion reactors. It is chosen because it offers highest pumping speed as well as the only suitable pump for the harsh environments in a tokamak. Towards the development of such cryosorption pumps, the optimal choice of the right activated carbon panels is essential. In order to characterize the performance of the panels with indigenously developed activated carbon, a cryocooler based cryosorption pump with scaled down sizes of panels is experimented. The results are compared with the commercial cryopanel used in a CTI cryosorption (model: Cryotorr 7) pump. The cryopanel is mounted on the cold head of the second stage GM cryocooler which cools the cryopanel down to 11K with first stage reaching about ∼50K. With no heat load, cryopump gives the ultimate vacuum of 2.1E-7 mbar. The pumping speed of different gases such as nitrogen, argon, hydrogen, helium are tested both on indigenous and commercial cryopanel. These studies serve as a bench mark towards the development of better cryopanels to be cooled by liquid helium for use with tokamak.

  7. Synthesis of flexible electrodes based on electrospun carbon nanofibers with Mn_3O_4 nanoparticles for vanadium redox flow battery application

    International Nuclear Information System (INIS)

    Di Blasi, A.; Busaccaa, C.; Di Blasia, O.; Briguglioa, N.; Squadritoa, G.; Antonuccia, V.

    2017-01-01

    Highlights: • Mn_3O_4/CNF electrode is investigated for vanadium redox flow battery application. • The high reversibility is ascribed to the several type of redox couples on the spinel structure. • Cell electrochemical parameters confirm the high reversibility for Mn_3O_4/CNF electrodes. - Abstract: Flexible carbon nanofiber (CNF)-based electrodes and CNF with a 20% of manganese oxide incorporated (Mn_3O_4/CNF) are prepared by using the electrospinning method for vanadium redox flow battery (VRFB) application. A blend consisting of manganese acetate (Mn(OAc)_2) and polyacrilonitrile (PAN) is electrospun and successively subjected to different thermal treatments in which the growth of Mn_3O_4 particles and CNFs occurred together guaranteeing an appropriate electron conductivity for electrodes thus synthesized. Cyclic voltammetry (CV) measurements show an interesting electrocatalytic activity toward the [VO]"2"+/[VO_2]"+ as well as the V"2"+/V"3"+ redox reactions for the Mn_3O_4/CNF electrospun sample. Charge-discharge tests, carried out at 80 mA cm"−"2, show a state of charge (SOC) and a depth of discharge (DoD) of 81% and 73%, respectively, for the cells assembled with Mn_3O_4/CNF electrodes. These data are indicative of a high vanadium active species utilization thanks to the better electrocatalytic activity at high current densities. Furthermore, the cell with Mn_3O_4/CNF shows EE values of about 81% (88% of VE and 92% of CE) vs. 70% (75% of VE and 93% of CE) with respect to a commercial carbon felt (CF) electrode used for comparison. These results are attributable to the higher oxygen species content as well as the improved electron conductivity due to the synergetic effect of the more graphitic carbon and to the structural defects within the Mn_3O_4 spinel structure.

  8. 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

  9. 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

  10. La dionisización del dios Pan

    Directory of Open Access Journals (Sweden)

    Silvia Porres Caballero

    2012-09-01

    Full Text Available Pan is a god peculiar in many respects. In contrast to the other gods of the Greek pantheon, he is not anthropomorphic, but he has the legs, tail and horns of a goat. These features show his age. A god like Pan can only survive in Arcadia, a region that preserves many religious archaisms. However, from 490 BC, when his cult is established in Athens, this god begins to change. In his evolution, Pan becomes increasingly assimilated the god Dionysus. The rapprochement between the two gods left his mark on the mythology, but especially in the cult of Pan. Thus, a god who was worshiped in Arcadia in sanctuaries built by men, in the rest of Greece is worshiped in wild shrines, mainly caves. Out of Arcadia, the grotto also is the place reserved for the mystery cults, including the Dionysian ones. Does not seem a coincidence

  11. Preparation of mesohollow and microporous carbon nanofiber and its application in cathode material for lithium–sulfur batteries

    International Nuclear Information System (INIS)

    Wu, Yuanhe; Gao, Mingxia; Li, Xiang; Liu, Yongfeng; Pan, Hongge

    2014-01-01

    Highlights: • Mesohollow and microporous carbon fibers were prepared via electrospinning and carbonization. • Sulfur (S) incorporated into the porous fibers by thermal heating in 60 wt.%, forming composite. • S fills fully in the micropores and partially in the mesohollows of the carbon fibers. • The composite shows high capacity and capacity retention as cathode material for Li–S batteries. • Mesohollow and microporous structure is effective in improving the property of S cathode. - Abstract: Mesohollow and microporous carbon nanofibers (MhMpCFs) were prepared by a coaxial electrospinning with polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) as outer and inner spinning solutions followed by a carbonization. The carbon fibers were thermal treated with sublimed sulfur to form S/MhMpCFs composite, which was used as cathode material for lithium–sulfur batteries. Electrochemical study shows that the S/MhMpCFs cathode material provides a maximum capacity of 815 mA h/g after several cycles of activation, and the capacity retains 715 mA h/g after 70 cycles, corresponding to a retention of 88%. The electrochemical property of the S/MhMpCFs composite is much superior than the S-incorporated solid carbon fibers prepared from electrospinning of single PAN. The mechanism of the enhanced electrochemical property of the S/MhMpCFs composite is discussed

  12. Identification of novel aroma-active thiols in pan-roasted white sesame seeds.

    Science.gov (United States)

    Tamura, Hitoshi; Fujita, Akira; Steinhaus, Martin; Takahisa, Eisuke; Watanabe, Hiroyuki; Schieberle, Peter

    2010-06-23

    Screening for aroma-active compounds in an aroma distillate obtained from freshly pan-roasted sesame seeds by aroma extract dilution analysis revealed 32 odorants in the FD factor range of 2-2048, 29 of which could be identified. The highest FD factors were found for the coffee-like smelling 2-furfurylthiol, the caramel-like smelling 4-hydroxy-2,5-dimethyl-3(2H)-furanone, the coffee-like smelling 2-thenylthiol (thiophen-2-yl-methylthiol), and the clove-like smelling 2-methoxy-4-vinylphenol. In addition, 9 odor-active thiols with sulfurous, meaty, and/or catty, black-currant-like odors were identified for the first time in roasted sesame seeds. Among them, 2-methyl-1-propene-1-thiol, (Z)-3-methyl-1-butene-1-thiol, (E)-3-methyl-1-butene-1-thiol, (Z)-2-methyl-1-butene-1-thiol, (E)-2-methyl-1-butene-1-thiol, and 4-mercapto-3-hexanone were previously unknown as food constituents. Their structures were confirmed by comparing their mass spectra and retention indices as well as their sensory properties with those of synthesized reference compounds. The relatively unstable 1-alkene-1-thiols represent a new class of food odorants and are suggested as the key contributors to the characteristic, but quickly vanishing, aroma of freshly ground roasted sesame seeds.

  13. Surface chemistry of polyacrylonitrile- and rayon-based activated carbon fibers after post-heat treatment

    International Nuclear Information System (INIS)

    Chiang Yuchun; Lee, C.-Y.; Lee, H.-C.

    2007-01-01

    Polyacrylonitrile- and rayon-based activated carbon fibers (ACFs) subject to heat treatment were investigated by means of elemental analyzer, and X-ray photoelectron spectroscopy (XPS). The total ash content of all ACFs was also analyzed. The adsorption of benzene, carbon tetrachloride and water vapor on ACFs was determined to shed light on the role of surface chemistry on gas adsorption. Results show that different precursors resulted in various elemental compositions and imposed diverse influence upon surface functionalities after heat treatment. The surface of heat-treated ACFs became more graphitic and hydrophobic. Three distinct peaks due to C, N, and O atoms were identified by XPS, and the high-resolution revealed the existence of several surface functionalities. The presence of nitride-like species, aromatic N-imines, or chemisorbed nitrogen oxides was found to be of great advantage to adsorption of water vapor or benzene, but the pyridine-N was not. Unstable complexes on the surface would hinder the fibers from adsorption of carbon tetrachloride. The rise in total ash content or hydrogen composition was of benefit to the access of water vapor. Modifications of ACFs by heat treatment have effectively improved adsorption performance

  14. An assessment methodology for determining pesticides adsorption on granulated activated carbon

    Directory of Open Access Journals (Sweden)

    Barthélemy J.-P.

    2003-01-01

    Full Text Available In many countries, water suppliers add granular activated carbon reactor in the drinking water treatment notably in order to remove pesticides residues. In Europe, their concentrations must lie below the values imposed by the EU directives (98/83/EC. Acouple of years ago, some mini-column tests were developed to improve the use of the activated carbon reactor in relation with lab experiments. Modelling, which was elaborated to predict the lifetime of reactors, did not bring validated results. Nevertheless, this kind of experiment allows us to assess the adsorption performances of an activated carbon for different pesticides. Because of the lack of comparable available results, we have eveloped a standardized methodology based on the experiment in mini-column of granular activated carbon. The main experimental conditions are activated carbon: Filtrasorb 400 (Chemviron Carbon; water: mineral and organic reconstituted water (humic acid concentration: 0,5 mg/l; influent concentration 500 g . l -1 ; activated carbon weight: 200 mg; EBCT (Empty Bed Contact Time: 0.16 min.; linear speed: 0.15 m . s -1 . In these conditions, it appears that diuron is highly adsorbed in comparison with other active substances like chloridazon, atrazine or MCPA. From the ratio of effluent volume for the breakthrough point with respect to diuron, it is suggested that products of which the difference factor ratio is – (a below 0.40: may be reckoned as weakly adsorbed (MCPA; (b from 0.41 to 0.80: may be reckoned as moderately adsorbed (chloridazon and atrazine; (c above 0.80: as highly adsorbed on granular activated carbon. Active substances that are weakly adsorbed and have to be removed from drinking water, may highly reduce the lifetime of an activated carbon bed. This kind of information is particularly useful for water suppliers and for regulatory authorities.

  15. Supercapacitors from Activated Carbon Derived from Granatum.

    Science.gov (United States)

    Wang, Qiannan; Yang, Lin; Wang, Zhao; Chen, Kexun; Zhang, Lipeng

    2015-12-01

    Granatum carbon (GC) as electrode materials for supercapacitors is prepared via the chemical activation with different activating agent such as ZnC2 and KOH with an intention to improve the surface area and their electrochemical performance. The structure and electrochemical properties of GC materials are characterized with N2 adsorption/desorption measurements, scanning electron microscope (SEM), cyclic voltammetry (CV), galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy (EIS). The obtained results show that the specific surface area of the granatum-based activated carbons increased obviously from 573 m2 x g(-1) to 1341 m2 x g(-1) by ZnC2 activation and to 930 m2 x g(-1) by KOH treatment. Furthermore, GCZ also delivers specific capacitance of 195.1 Fx g(-1) at the current density of 0.1 A x g(-1) in 30 wt.% KOH aqueous electrolyte and low capacitance loss of 28.5% when the current density increased by 10 times.

  16. TAILORING ACTIVATED CARBONS FOR ENHANCED REMOVAL OF NATURAL ORGANIC MATTER FROM NATURAL WATERS. (R828157)

    Science.gov (United States)

    Several pathways have been employed to systematically modify two granular activated carbons (GACs), F400 (coal-based) and Macro (wood-based), for examining adsorption of dissolved natural organic matter (DOM) from natural waters. A total of 24 activated carbons with different ...

  17. Carbon nanotube based pressure sensor for flexible electronics

    International Nuclear Information System (INIS)

    So, Hye-Mi; Sim, Jin Woo; Kwon, Jinhyeong; Yun, Jongju; Baik, Seunghyun; Chang, Won Seok

    2013-01-01

    Highlights: • The electromechanical change of vertically aligned carbon nanotubes. • Fabrication of CNT field-effect transistor on flexible substrate. • CNT based FET integrated active pressure sensor. • The integrated device yields an increase in the source-drain current under pressure. - Abstract: A pressure sensor was developed based on an arrangement of vertically aligned carbon nanotubes (VACNTs) supported by a polydimethylsiloxane (PDMS) matrix. The VACNTs embedded in the PDMS matrix were structurally flexible and provided repeated sensing operation due to the high elasticities of both the polymer and the carbon nanotubes (CNTs). The conductance increased in the presence of a loading pressure, which compressed the material and induced contact between neighboring CNTs, thereby producing a dense current path and better CNT/metal contacts. To achieve flexible functional electronics, VACNTs based pressure sensor was integrated with field-effect transistor, which is fabricated using sprayed semiconducting carbon nanotubes on plastic substrate

  18. Carbon nanotube based pressure sensor for flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    So, Hye-Mi [Department of Nano Mechanics, Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon 305-343 (Korea, Republic of); Sim, Jin Woo [Advanced Nano Technology Ltd., Seoul 132-710 (Korea, Republic of); Kwon, Jinhyeong [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Yun, Jongju; Baik, Seunghyun [SKKU Advanced Institute of Nanotechnology (SAINT), Department of Energy Science and School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Chang, Won Seok, E-mail: paul@kimm.re.kr [Department of Nano Mechanics, Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon 305-343 (Korea, Republic of)

    2013-12-15

    Highlights: • The electromechanical change of vertically aligned carbon nanotubes. • Fabrication of CNT field-effect transistor on flexible substrate. • CNT based FET integrated active pressure sensor. • The integrated device yields an increase in the source-drain current under pressure. - Abstract: A pressure sensor was developed based on an arrangement of vertically aligned carbon nanotubes (VACNTs) supported by a polydimethylsiloxane (PDMS) matrix. The VACNTs embedded in the PDMS matrix were structurally flexible and provided repeated sensing operation due to the high elasticities of both the polymer and the carbon nanotubes (CNTs). The conductance increased in the presence of a loading pressure, which compressed the material and induced contact between neighboring CNTs, thereby producing a dense current path and better CNT/metal contacts. To achieve flexible functional electronics, VACNTs based pressure sensor was integrated with field-effect transistor, which is fabricated using sprayed semiconducting carbon nanotubes on plastic substrate.

  19. Electrochemical Performance of Electrospun carbon nanofibers as free-standing and binder-free anodes for Sodium-Ion and Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Jin, Juan; Shi, Zhi-qiang; Wang, Cheng-yang

    2014-01-01

    Highlights: • Electrospun carbon nanofiber webs were prepared by pyrolysis of polyacrylonitrile. • The webs as binder-free and current collector-free electrodes for SIBs and LIBs. • Different layer spacing and pore size for Li and Na lead different electrochemical behavior. • Electrochemical performances of the electrodes were high. - Abstract: A series of hard carbon nanofiber-based electrodes derived from electrospun polyacrylonitrile (PAN) nanofibers (PAN-CNFs) have been fabricated by stabilization in air at about 280 °C and then carbonization in N 2 at heat treatment temperatures (HTT) between 800 and 1500 °C. The electrochemical performances of the binder-free, current collector-free carbon nanofiber-based anodes in lithium-ion batteries and sodium-ion batteries are systematically investigated and compared. We demonstrate the presence of similar alkali metal insertion mechanisms in both cases, but just the differences of the layer spacing and pore size available for lithium and sodium ion lead the discharge capacity delivered at sloping region and plateau region to vary from the kinds of alkali elements. Although the anodes in sodium-ion batteries show poorer rate capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 275 mAh g −1 and similar cycling stability due to the conductive 3-D network, weakly ordered turbostratic structure and a large interlayer spacing between graphene sheets. The feature of high capacity and stable cycling performance makes PAN-CNFs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries

  20. 75 FR 47262 - Federal Consistency Appeal by Pan American Grain Co.

    Science.gov (United States)

    2010-08-05

    ... by Pan American Grain Co. AGENCY: National Oceanic and Atmospheric Administration (NOAA), Department..., closure of the decision record in an administrative appeal filed by Pan American Grain Co. (Pan American..., 2010, Pan American Grain Co. filed notice of an appeal with the Secretary of Commerce (Secretary...

  1. Pan-Tropical Analysis of Climate Effects on Seasonal Tree Growth

    Science.gov (United States)

    Wagner, Fabien; Rossi, Vivien; Aubry-Kientz, Mélaine; Bonal, Damien; Dalitz, Helmut; Gliniars, Robert; Stahl, Clément; Trabucco, Antonio; Hérault, Bruno

    2014-01-01

    Climate models predict a range of changes in tropical forest regions, including increased average temperatures, decreased total precipitation, reduced soil moisture and alterations in seasonal climate variations. These changes are directly related to the increase in anthropogenic greenhouse gas concentrations, primarily CO2. Assessing seasonal forest growth responses to climate is of utmost importance because woody tissues, produced by photosynthesis from atmospheric CO2, water and light, constitute the main component of carbon sequestration in the forest ecosystem. In this paper, we combine intra-annual tree growth measurements from published tree growth data and the corresponding monthly climate data for 25 pan-tropical forest sites. This meta-analysis is designed to find the shared climate drivers of tree growth and their relative importance across pan-tropical forests in order to improve carbon uptake models in a global change context. Tree growth reveals significant intra-annual seasonality at seasonally dry sites or in wet tropical forests. Of the overall variation in tree growth, 28.7% was explained by the site effect, i.e. the tree growth average per site. The best predictive model included four climate variables: precipitation, solar radiation (estimated with extrasolar radiation reaching the atmosphere), temperature amplitude and relative soil water content. This model explained more than 50% of the tree growth variations across tropical forests. Precipitation and solar radiation are the main seasonal drivers of tree growth, causing 19.8% and 16.3% of the tree growth variations. Both have a significant positive association with tree growth. These findings suggest that forest productivity due to tropical tree growth will be reduced in the future if climate extremes, such as droughts, become more frequent. PMID:24670981

  2. Optimization of microwave-assisted rubberwood sawdust based activated carbon preparation conditions for methylene blue removal

    Science.gov (United States)

    Khasri, Azduwin; Ahmad, Mohd Azmier

    2017-10-01

    Optimum preparation conditions of rubberwood sawdust based activated carbon (RSAC) for methylene blue (MB) dye removal was studied. RSAC was produced by applying physiochemical activation method by using potassium hydroxide as a chemical agent which accompanied by carbon dioxide gasification under microwave heating. The effects of microwave power, irradiation time and impregnation ratio on two types of responses namely MB removal and RSAC yield using the center composite design (CCD) were also included in this study. The preparation variables correlation for responses was developed by two quadratic models. Optimum preparation conditions of RSAC were obtained at microwave power, irradiation time and IR of 354 W, 4.5 minutes and 0.98, respectively, which resulted MB removal and yield of 83.79% and 28%, respectively. The average pore diameter, surface area and total pore volume of optimized RSAC were 4.12 nm, 796.33 m2/g and 0.4219 cm3/g, respectively. This sample was found to has well-developed pores on its surface and can be a promising adsorbent for MB removal from aqueous solution.

  3. Exploring Pan-Africanism's theories: from race-based solidarity to political unity and beyond

    Czech Academy of Sciences Publication Activity Database

    Kasanda, Albert

    2016-01-01

    Roč. 28, č. 2 (2016), s. 179-195 ISSN 1369-6815 Institutional support: RVO:67985955 Keywords : solidarity * unity * sovereignty * race * Africa * Afropolitanism * Pan-Africanism * colonization Subject RIV: AA - Philosophy ; Religion Impact factor: 0.917, year: 2016

  4. Application of factorial designs and Doehlert matrix in optimization of experimental variables associated with the preconcentration and determination of vanadium and copper in seawater by inductively coupled plasma optical emission spectrometry

    International Nuclear Information System (INIS)

    Ferreira, Sergio L.C.; Queiroz, Adriana S.; Fernandes, Marcelo S.; Santos, Hilda C. dos

    2002-01-01

    In the present paper a procedure for preconcentration and determination of vanadium and copper in seawater using inductively coupled plasma optical emission spectrometry (ICP OES) is proposed, which is based on solid-phase extraction of vanadium (IV), vanadium (V) and copper (II) ions as 1-(2-pyridylazo)-2-naphthol (PAN) complexes by active carbon. The optimization process was carried out using two-level full factorials and Doehlert matrix designs. Four variables (PAN mass, pH, active carbon mass and shaking time) were regarded as factors in the optimization. Results of the two-level full factorial design 2 4 with 16 runs for vanadium extraction, based on the variance analysis (ANOVA), demonstrated that the factors pH and active carbon mass, besides the interaction (pHxactive carbon mass), are statistically significant. For copper, the ANOVA revealed that the factors PAN mass, pH and active carbon mass and the interactions (PAN massxpH) and (pHxactive carbon mass) are statistically significant. Doehlert designs were applied in order to determine the optimum conditions for extraction. The procedure proposed allowed the determination of vanadium and copper with detection limits (3σ/S) of 73 and 94 ng l -1 , respectively. The precision, calculated as relative standard deviation (R.S.D.), was 1.22 and 1.37% for 12.50 μg l -1 of vanadium and copper, respectively. The preconcentration factor was 80. The recovery achieved for determination of vanadium and copper in the presence of several cations demonstrated that this procedure improved the selectivity required for seawater analysis. The procedure was applied to the determination of vanadium and copper in seawater samples collected in Salvador City, Brazil. Results showed good agreement with other data reported in the literature

  5. 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.

  6. CFD Modelling of Adsorption Behaviour in AGN Tank with Polyethylene Terephthalate Plastic Waste Based Activated Carbon

    Science.gov (United States)

    Yuliusman; Afdhol, M. K.; Sanal, Alristo; Nasruddin

    2018-03-01

    Indonesia imports fuel (fuel oil) in large quantities. Indonesia has reserves of methane gas in the form of natural gas in large numbers but has obstacles in the process of storage. To produce a storage tank to a safe condition then proclaimed to use ANG (Adsorbed Natural Gas) technology. Manufacture of activated PET based activated carbon for storage of natural gas where technology has been widely studied, but still has some shortcomings. Therefore to predict the performance of ANG technology, modeling of ANG tank with Fluent CFD program is done so the condition inside the ANG tank can be known and can be used to increased the performance of ANG technology. Therefore, in this experiment natural gas storage test is done at the ANG tank model using Fluent CFD program. This experiment is begin with preparation tools and material by characterize the natural gas and activated carbon followed by create the mesh and model of ANG tank. The next process is state the characteristic of activated carbon and fluid in this experiment. The last process is run the simulation using the condition that already been stated which is at 27°C and 35 bar during 15 minutes. The result is at adsorption contour we can see that adsorption is higher at the top of the tank because the input of the adsorbent is at the top of the ANG tank so the adsorbate distribution is uneven that cause the adsorbate concentration at the top of the ANG tank is higher than the bottom tank.

  7. A Peptide-Fc Opsonin with Pan-Amyloid Reactivity

    Directory of Open Access Journals (Sweden)

    James S. Foster

    2017-09-01

    Full Text Available There is a continuing need for therapeutic interventions for patients with the protein misfolding disorders that result in systemic amyloidosis. Recently, specific antibodies have been employed to treat AL amyloidosis by opsonizing tissue amyloid deposits thereby inducing cell-mediated dissolution and organ improvement. To develop a pan-amyloid therapeutic agent, we have produced an Fc-fusion product incorporating a peptide, p5, which binds many if not all forms of amyloid. This protein, designated Fcp5, expressed in mammalian cells, forms the desired bivalent dimer structure and retains pan-amyloid reactivity similar to the p5 peptide as measured by immunosorbent assays, immunohistochemistry, surface plasmon resonance, and pulldown assays using radioiodinated Fcp5. Additionally, Fcp5 was capable of opsonizing amyloid fibrils in vitro using a pH-sensitive fluorescence assay of phagocytosis. In mice,125 I-labeled Fcp5 exhibited an extended serum circulation time, relative to the p5 peptide. It specifically bound AA amyloid deposits in diseased mice, as evidenced by biodistribution and microautoradiographic methods, which coincided with an increase in active, Iba-1-positive macrophages in the liver at 48 h postinjection of Fcp5. In healthy mice, no specific tissue accumulation was observed. The data indicate that polybasic, pan-amyloid-targeting peptides, in the context of an Fc fusion, can yield amyloid reactive, opsonizing reagents that may serve as next-generation immunotherapeutics.

  8. Carbon-based nanomaterials: multifunctional materials for biomedical engineering.

    Science.gov (United States)

    Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R; Khademhosseini, Ali

    2013-04-23

    Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), and extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications.

  9. Pan genome of the phytoplankton Emiliania underpins its global distribution.

    Science.gov (United States)

    Read, Betsy A; Kegel, Jessica; Klute, Mary J; Kuo, Alan; Lefebvre, Stephane C; Maumus, Florian; Mayer, Christoph; Miller, John; Monier, Adam; Salamov, Asaf; Young, Jeremy; Aguilar, Maria; Claverie, Jean-Michel; Frickenhaus, Stephan; Gonzalez, Karina; Herman, Emily K; Lin, Yao-Cheng; Napier, Johnathan; Ogata, Hiroyuki; Sarno, Analissa F; Shmutz, Jeremy; Schroeder, Declan; de Vargas, Colomban; Verret, Frederic; von Dassow, Peter; Valentin, Klaus; Van de Peer, Yves; Wheeler, Glen; Dacks, Joel B; Delwiche, Charles F; Dyhrman, Sonya T; Glöckner, Gernot; John, Uwe; Richards, Thomas; Worden, Alexandra Z; Zhang, Xiaoyu; Grigoriev, Igor V

    2013-07-11

    Coccolithophores have influenced the global climate for over 200 million years. These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems. They form blooms that can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering them visible from space. Although coccolithophores export carbon in the form of organic matter and calcite to the sea floor, they also release CO2 in the calcification process. Hence, they have a complex influence on the carbon cycle, driving either CO2 production or uptake, sequestration and export to the deep ocean. Here we report the first haptophyte reference genome, from the coccolithophore Emiliania huxleyi strain CCMP1516, and sequences from 13 additional isolates. Our analyses reveal a pan genome (core genes plus genes distributed variably between strains) probably supported by an atypical complement of repetitive sequence in the genome. Comparisons across strains demonstrate that E. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires. Genome variability within this species complex seems to underpin its capacity both to thrive in habitats ranging from the equator to the subarctic and to form large-scale episodic blooms under a wide variety of environmental conditions.

  10. 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

  11. 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...

  12. Control of Pan-tilt Mechanism Angle using Position Matrix Method

    Directory of Open Access Journals (Sweden)

    Hendri Maja Saputra

    2013-12-01

    Full Text Available Control of a Pan-Tilt Mechanism (PTM angle for the bomb disposal robot Morolipi-V2 using inertial sensor measurement unit, x-IMU, has been done. The PTM has to be able to be actively controlled both manually and automatically in order to correct the orientation of the moving Morolipi-V2 platform. The x-IMU detects the platform orientation and sends the result in order to automatically control the PTM. The orientation is calculated using the quaternion combined with Madwick and Mahony filter methods. The orientation data that consists of angles of roll (α, pitch (β, and yaw (γ from the x-IMU are then being sent to the camera for controlling the PTM motion (pan & tilt angles after calculating the reverse angle using position matrix method. Experiment results using Madwick and Mahony methods show that the x-IMU can be used to find the robot platform orientation. Acceleration data from accelerometer and flux from magnetometer produce noise with standard deviation of 0.015 g and 0.006 G, respectively. Maximum absolute errors caused by Madgwick and Mahony method with respect to Xaxis are 48.45º and 33.91º, respectively. The x-IMU implementation as inertia sensor to control the Pan-Tilt Mechanism shows a good result, which the probability of pan angle tends to be the same with yaw and tilt angle equal to the pitch angle, except a very small angle shift due to the influence of roll angle..

  13. Status and Evolution of ATLAS Workload Management System PanDA

    CERN Document Server

    AUTHOR|(CDS)2067365; The ATLAS collaboration

    2012-01-01

    The ATLAS experiment at the LHC uses a sophisticated workload management system, PanDA, to provide access for thousands of physicists to distributed computing resources of unprecedented scale. This system has proved to be robust and scalable during three years of LHC operations. We describe the design and performance of PanDA in ATLAS. The features which make PanDA successful in ATLAS could be applicable to other exabyte scale scientific projects. We describe plans to evolve PanDA towards a general workload management system for the new BigData initiative announced by the US government. Other planned future improvements to PanDA will also be described

  14. Magneto-carbonization method for production of carbon fiber, and high performance carbon fibers made thereby

    Science.gov (United States)

    Naskar, Amit K.; Ozcan, Soydan; Eberle, Claude C.; Abdallah, Mohamed Gabr; Mackiewicz, Ludtka Gail; Ludtka, Gerard Michael; Paulauskas, Felix Leonard; Rivard, John Daniel Kennedy

    2017-08-08

    Method for the preparation of carbon fiber from fiber precursor, wherein the fiber precursor is subjected to a magnetic field of at least 3 Tesla during a carbonization process. The carbonization process is generally conducted at a temperature of at least 400.degree. C. and less than 2200.degree. C., wherein, in particular embodiments, the carbonization process includes a low temperature carbonization step conducted at a temperature of at least or above 400.degree. C. or 500.degree. C. and less than or up to 1000.degree. C., 1100.degree. C., or 1200.degree. C., followed by a high temperature carbonization step conducted at a temperature of at least or above 1200.degree. C. In particular embodiments, particularly in the case of a polyacrylonitrile (PAN) fiber precursor, the resulting carbon fiber may possess a minimum tensile strength of at least 600 ksi, a tensile modulus of at least 30 Msi, and an ultimate elongation of at least 1.5%.

  15. The influence of Mn species on the SO{sub 2} removal of Mn-based activated carbon catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Yi-Fan [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Guo, Jia-Xiu, E-mail: guojiaxiu@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China); Chu, Ying-Hao [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China); Sun, Ming-Chao [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Yin, Hua-Qiang, E-mail: hqyin@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065 (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065 (China)

    2013-10-01

    Using Mn(NO{sub 3}){sub 2} as precursor, a series of Mn-based activated carbon catalysts were prepared by ultrasound-assisted excessive impregnation method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The influences of Mn species and nitric acid pretreatment on the removal role of SO{sub 2} were investigated. MnO and Mn{sub 3}O{sub 4} coexist in catalysts calcined at 650 and 800 °C and exhibit best SO{sub 2} removal ability, whereas Mn{sub 2}O{sub 3} formed in the catalyst calcined at 500 °C and shows poor activity. After treatment by nitric acid, the C=O of activated carbon support increases and the crystal size of MnO decreases, resulting in the enhancement of the catalytic activity. During reaction process, manganese oxides are gradually transferred into MnO{sub 2}. And this change directly results in a decrease of activity. But the SO{sub 2} removal rate has been maintained in the range of 30–40%, indicating that MnO{sub 2} still has a certain SO{sub 2} removal ability.

  16. 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

  17. SiCO-doped carbon fibers with unique dual superhydrophilicity/superoleophilicity and ductile and capacitance properties.

    Science.gov (United States)

    Lu, Ping; Huang, Qing; Mukherjee, Amiya; Hsieh, You-Lo

    2010-12-01

    Silicon oxycarbide (SiCO) glass-doped carbon fibers with an average diameter of 163 nm were successfully synthesized by electrospinning polymer mixtures of preceramic precursor polyureasilazane (PUS) and carbon precursor polyacrylonitrile (PAN) into fibers then converting to ceramic/carbon hybrid via cross-linking, stabilization, and pyrolysis at temperatures up to 1000 °C. The transformation of PUS/PAN polymer precursors to SiCO/carbon structures was confirmed by EDS and FTIR. Both carbon and SiCO/carbon fibers were amorphous and slightly oxidized. Doping with SiCO enhanced the thermal stability of carbon fibers and acquired new ductile behavior in the SiCO/carbon fibers with significantly improved flexibility and breaking elongation. Furthermore, the SiCO/carbon fibers exhibited dual superhydrophilicity and superoleophilicity with water and decane absorbing capacities of 873 and 608%, respectively. The cyclic voltammetry also showed that SiCO/carbon composite fibers possess better capacitor properties than carbon fibers.

  18. Radioimmunodetection of human pancreatic tumor xenografts using DU-PAN II monoclonal antibody

    International Nuclear Information System (INIS)

    Nakamura, Kayoko; Kubo, Atsushi; Hashimoto, Shozo; Furuuchi, Takayuki; Abe, Osahiko; Takami, Hiroshi.

    1988-01-01

    The potential of DU-PAN II, monoclonal antibody (IgM), which was raised against the human tumor cell line, was evaluated for radioimmunodetection of human pancreatic tumors (PAN-5-JCK and EXP-58) grown in nude mice. 125 I-labeled DU-PAN II was accumulated into PAN-5-JCK producing DU-PAN II antigen with a tumor-to-blood ratio of 2.72 ± 3.00, but it did not localize in EXP-58 because of insufficient DU-PAN II. There was no significant uptake of 125 I-nonimmunized IgM in PAN-5-JCK. These facts indicated the specific tumor uptake of DU-PAN II. Excellent images of the tumor PAN-5-JCK were obtained 3 days after the injection of 125 I-DU-PAN II. Gel chromatography was also investigated with respect to the plasma taken from mice injected with antibody, or incubated with antibody in vitro. The results indicate that circulating antigen affected the tumor uptake of DU-PAN II: The more the tumor grew, the higher the amount of antigen excreted into the blood, leading to the degradation of DU-PAN II before it reached the tumor sites. Consequently, the immunoscintigram of the small tumor was remarkably clear. The catabolism and the radiolysis of the labeled IgM injected are critical points in applying immunoscintigraphy. (author)

  19. 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

  20. 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.

  1. Electricity generation from wetlands with activated carbon bioanode

    Science.gov (United States)

    Sudirjo, E.; Buisman, C. J. N.; Strik, D. P. B. T. B.

    2018-03-01

    Paddy fields are potential non-tidal wetlands to apply Plant Microbial Fuel Cell (PMFC) technology. World widely they cover about 160 million ha of which 13.3 million ha is located in Indonesia. With the PMFC, in-situ electricity is generated by a bioanode with electrochemically active bacteria which use primary the organic matter supplied by the plant (e.g. as rhizodeposits and plant residues). One of limitations when installing a PMFC in a non-tidal wetland is the usage of “expensive” large amounts of electrodes to overcome the poor conductivity of wet soils. However, in a cultivated wetland such as rice paddy field, it is possible to alter soil composition. Adding a conductive carbon material such as activated carbon is believed to improve soil conductivity with minimum impact on plant vitality. The objective of this research was to study the effect of activated carbon as an alternative bioanode material on the electricity output and plants vitality. Lab result shows that activated carbon can be a potential alternative for bioanode material. It can continuously deliver current on average 1.54 A/m3 anode (0.26 A/m2 PGA or 66 mW/m2 PGA) for 98 days. Based on this result the next step is to do a test of this technology in the real paddy fields.

  2. Characterization of coal gasification slag-based activated carbon and its potential application in lead removal.

    Science.gov (United States)

    Xu, Yiting; Chai, Xiaoli

    2018-02-01

    Highly porous activated carbons were prepared from a coal gasification slag (CGS) precursor, by KOH activation to remove Pb 2+ from aqueous solution. The effects of pretreatment methods and activation parameters on the properties of the activated carbon were investigated, such as KOH/CGS mass ratio, activation temperature and activation time. The results showed that the maximum Brunauer-Emmett-Teller surface area and total pore volume with the value of 2481 m 2  g -1 and of 1.711 cc g -1 were obtained at a KOH/CGS ratio of 3.0 by physical mixing, an activation temperature of 750°C and an activation time of 80 min. SEM, FTIR and EA analyses indicated that pronounced pores existed on the exterior surface of the activated samples, and the contents of H and O decreased due to the loss of surface chemical groups during activation. Experimental data for the Pb 2+ adsorption were fitted well by Freundlich equation and a pseudo-second-order model with a maximum experimental adsorption capacity of 141 mg/g. All of the results indicated that CGS could be a promising material to prepare porous activated carbon for Pb 2+ removal from wastewater.

  3. A new two-Dimensional Physical Basis for the Complementary Relation Between Terrestrial and pan Evaporation

    Science.gov (United States)

    Pettijohn, J. C.; Salvucci, G. D.

    2008-12-01

    Archived global measurements of water loss from evaporation pans constitute an important indirect measure of evaporative flux. Historical data from evaporation pans shows a decreasing trend over the last half century, but the relationship between pan evaporation and moisture-limited terrestrial evaporation is complex, leading to ambiguities in the interpretation of this data. Under energy-limited conditions, pan evaporation (Epan) and moisture-limited terrestrial evaporation (E) increase or decrease together, while in moisture- limited conditions these fluxes form a complementary relation in which increases in one rate accompany decreases in the other. This has lead to debate about the meaning of the observed trends in the context of changing climate. Here a two-dimensional numerical model of a wet pan in a drying landscape is used to demonstrate that, over a wide range of realistic atmospheric and surface conditions, the influence that changes in E have on Epan (1) are complementary and linear, (2) do not depend upon surface wind speed, and (3) are strikingly asymmetrical, in that a unit decrease in E causes approximately a five-fold increase in Epan, as found in a recent analysis of daily evaporation from US grasslands (Kahler and Brutsaert, 2006). Previous attempts to explain the CR have been based on one dimensional diffusion and energy balance arguments, leading to analytic solutions based on Penman-type bulk difference equations. But without acknowledging the spatially complex multidimensional humidity and temperature field around the pan, and specifically how these fields change as the contrast between the wet pan and the drying land surface increases, such integrated bulk difference equations are a priori incomplete (they ignore important divergence terms), and thus these explanations must be considered physically incomplete. Results of the present study improve the theoretical foundation of the CR, thus increasing the reliability with which it can be

  4. Supercapacitor Electrode Materials from Highly Porous Carbon Nanofibers with Tailored Pore Distributions

    Science.gov (United States)

    Chathurika Abeykoon, Nimali

    for EDLCs. It also explains the necessity and the advantages of tailored high surface area nanofibers as an electrode materials for supercapacitors. Chapter 2 describes the preparation of high surface area carbon nanofibers using polymer blends containing PAN and PMMA and introduces an effective and simple strategy to improve the surface area of CNFs by using a sacrificial polymer, PMMA. Chapter 3 describes blending of high fractional free volume polymer, 6FDA-DAM: DABA (3:2) into PBI to increase surface area and by using the higher etch rate of 6FDA-DAM: DABA in the blend to optimize pore distribution of CNFs. Chapter 4 introduces a novel approach to increase surface area of CNFs without any physical or chemical activation by using an in situ porogen containing copolymer P(AN-co-IA). The concept developed here avoids unnecessary and complex extra activation steps when fabricating carbon nanofibers which leads to lower char yield and uncontrollable pore sizes. Chapter 5 describes enhancement of surface area by using terpolymer P(AN-VIM-IA) to develop a new precursor. This approach is further advantageous since terpolymer can combine superior electrochemical properties of homopolymer, PAN and P(AN- co-IA) and P(AN-co-VIM). Chapter 6 describes the use of commercially available small molecule compatibilizer 2-MI to tailor pore architecture of carbon fiber derived from the immiscible blend of PBI/6FDD to match with the ion sizes of ionic liquid electrolytes thereby increasing the surface area of the CNFs that is accessible to electrolytes.

  5. Comparing infant and juvenile behavior in bonobos (Pan paniscus) and chimpanzees (Pan troglodytes): a preliminary study.

    Science.gov (United States)

    De Lathouwers, Mieke; Van Elsacker, Linda

    2006-10-01

    The dichotomy between the two Pan species, the bonobo (Pan paniscus) and chimpanzee (Pan troglodytes) has been strongly emphasized until very recently. Given that most studies were primarily based on adult individuals, we shifted the "continuity versus discontinuity" discussion to the infant and juvenile stage. Our aim was to test quantitatively, some conflicting statements made in literature considering species differences between immature bonobos and chimpanzees. On one hand it is suggested that infant bonobos show retardation in motor and social development when compared with chimpanzees. Additionally it is expected that the weaning process is more traumatic to chimpanzee than bonobo infants. But on the other hand the development of behaviors is expected to be very similar in both species. We observed eight mother-infant pairs of each species in several European zoos. Our preliminary research partially confirms that immature chimpanzees seem spatially more independent, spending more time at a larger distance from their mother than immature bonobos. However, the other data do not seem to support the hypothesis that bonobo infants show retardation of motor or social development. The development of solitary play, environmental exploration, social play, non-copulatory mounts and aggressive interactions do not differ between the species. Bonobo infants in general even groom other group members more than chimpanzee infants. We also found that older bonobo infants have more nipple contact than same aged chimpanzees and that the weaning process seems to end later for bonobos than for immature chimpanzee. Additionally, although immature bonobos show in general more signs of distress, our data suggest that the weaning period itself is more traumatic for chimpanzees.

  6. Effect of potassium hydroxide activation in the desulfurization process of activated carbon prepared by sewage sludge and corn straw.

    Science.gov (United States)

    Zeng, Fan; Liao, Xiaofeng; Hu, Hui; Liao, Li

    2018-03-01

    Series sludge straw-based activated carbons were prepared by sewage sludge and corn straw with potassium hydroxide (KOH) activation, and the desulfurization performance of activated carbons was studied. To obtain the best desulfurization performance, the optimum ratio between the raw materials and the activator was investigated. The results showed that when the mass ratio of sewage sludge, corn straw, and KOH was 3:7:2, the activated carbon obtained the best breakthrough and saturation sulfur sorption capacities, which were 12.38 and 5.74 times, respectively, those of samples prepared by the nonactivated raw materials. The appropriate KOH could improve the microporosity and alkaline groups, meanwhile reducing the lactone groups, which were all beneficial to desulfurization performance. The chemical adsorption process of desulfurization can be simplified to four main steps, and the main desulfurization products are elemental sulfur and sulfate. Sewage sludge (SS) and corn straw (CS) both have great production and wide distribution and are readily available in China. Much attention has been paid on how to deal with them effectively. Based on the environment protection idea of waste treatment with waste and resource recycling, low-cost adsorbents were prepared by these processes. The proposed method can be expanded to the municipal solid waste recycling programs and renewable energy plan. Thus, proceeding with the study of preparing activated carbon by SS and straw as a carbon-based dry desulfurization agent could obtain huge social, economic, and environmental benefits.

  7. Preparation of steam activated carbon from rubberwood sawdust (Hevea brasiliensis) and its adsorption kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Prakash Kumar, B.G. [Department of Chemical Engineering, Alagappa College of Technology, Anna University, Chennai 600 025 (India); Shivakamy, K. [Centralised Waste Management Facility, Bhabha Atomic Research Centre, Kalpakkam 603 102 (India); Miranda, Lima Rose [Department of Chemical Engineering, Alagappa College of Technology, Anna University, Chennai 600 025 (India); Velan, M. [Department of Chemical Engineering, Alagappa College of Technology, Anna University, Chennai 600 025 (India)]. E-mail: velan@annauniv.edu

    2006-08-25

    Activated carbon was produced from a biowaste product, rubberwood sawdust (RWSD) using steam in a high temperature fluidized bed reactor. Experiments were carried out to investigate the influence of various process parameters such as activation time, activation temperature, particle size and fluidising velocity on the quality of the activated carbon. The activated carbon was characterized based on its iodine number, methylene blue number, Brauner Emmet Teller (BET) surface area and surface area obtained using the ethylene glycol mono ethyl ether (EGME) retention method. The best quality activated carbon was obtained at an activation time and temperature of 1 h and 750 deg. C for an average particle size of 0.46 mm. The adsorption kinetics shows that pseudo-second-order rate fitted the adsorption kinetics better than pseudo-first-order rate equation. The adsorption capacity of carbon produced from RWSD was found to be 1250 mg g{sup -1} for the Bismark Brown dye. The rate constant and diffusion coefficient for intraparticle transport were determined for steam activated carbon. The characteristic of the prepared activated carbon was found comparable to the commercial activated carbon.

  8. Carbon microelectromechanical systems (C-MEMS) based microsupercapacitors

    KAUST Repository

    Agrawal, Richa

    2015-05-18

    The rapid development in miniaturized electronic devices has led to an ever increasing demand for high-performance rechargeable micropower scources. Microsupercapacitors in particular have gained much attention in recent years owing to their ability to provide high pulse power while maintaining long cycle lives. Carbon microelectromechanical systems (C-MEMS) is a powerful approach to fabricate high aspect ratio carbon microelectrode arrays, which has been proved to hold great promise as a platform for energy storage. C-MEMS is a versatile technique to create carbon structures by pyrolyzing a patterned photoresist. Furthermore, different active materials can be loaded onto these microelectrode platforms for further enhancement of the electrochemical performance of the C-MEMS platform. In this article, different techniques and methods in order to enhance C-MEMS based various electrochemical capacitor systems have been discussed, including electrochemical activation of C-MEMS structures for miniaturized supercapacitor applications, integration of carbon nanostructures like carbon nanotubes onto C-MEMS structures and also integration of pseudocapacitive materials such as polypyrrole onto C-MEMS structures. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  9. Carbon microelectromechanical systems (C-MEMS) based microsupercapacitors

    KAUST Repository

    Agrawal, Richa; Beidaghi, Majid; Chen, Wei; Wang, Chunlei

    2015-01-01

    The rapid development in miniaturized electronic devices has led to an ever increasing demand for high-performance rechargeable micropower scources. Microsupercapacitors in particular have gained much attention in recent years owing to their ability to provide high pulse power while maintaining long cycle lives. Carbon microelectromechanical systems (C-MEMS) is a powerful approach to fabricate high aspect ratio carbon microelectrode arrays, which has been proved to hold great promise as a platform for energy storage. C-MEMS is a versatile technique to create carbon structures by pyrolyzing a patterned photoresist. Furthermore, different active materials can be loaded onto these microelectrode platforms for further enhancement of the electrochemical performance of the C-MEMS platform. In this article, different techniques and methods in order to enhance C-MEMS based various electrochemical capacitor systems have been discussed, including electrochemical activation of C-MEMS structures for miniaturized supercapacitor applications, integration of carbon nanostructures like carbon nanotubes onto C-MEMS structures and also integration of pseudocapacitive materials such as polypyrrole onto C-MEMS structures. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  10. 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

  11. Sulfur dioxide adsorption by activated carbons having different textural and chemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Nilgun Karatepe; Ilkun Orbak; Reha Yavuz; Ayse Ozyuguran [Istanbul Technical University, Istanbul (Turkey). Institute of Energy

    2008-11-15

    Activated carbons from Turkish lignite were prepared with different methods to investigate the influence of physico-chemical characteristics of the carbon materials on the sulfur dioxide (SO{sub 2}) adsorption. The effects of SO{sub 2} concentration, adsorption temperature, and sample particle size on adsorption were investigated using a thermogravimetric analysis system. An intraparticle diffusion model based on Knudsen diffusion and Freundlich isotherm (or Henry isotherm) was applied for predicting the amount of SO{sub 2} adsorbed. The textural and chemical properties of the activated carbon samples, resulted from the effects of activation conditions and demineralization of the carbon precursor, on the SO{sub 2} adsorption were also analyzed. 30 refs., 7 figs., 4 tabs.

  12. 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.

  13. Predictive accuracy of the PanCan lung cancer risk prediction model - external validation based on CT from the Danish Lung Cancer Screening Trial

    International Nuclear Information System (INIS)

    Winkler Wille, Mathilde M.; Dirksen, Asger; Riel, Sarah J. van; Jacobs, Colin; Scholten, Ernst T.; Ginneken, Bram van; Saghir, Zaigham; Pedersen, Jesper Holst; Hohwue Thomsen, Laura; Skovgaard, Lene T.

    2015-01-01

    Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination. AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor. (orig.)

  14. Predictive accuracy of the PanCan lung cancer risk prediction model - external validation based on CT from the Danish Lung Cancer Screening Trial

    Energy Technology Data Exchange (ETDEWEB)

    Winkler Wille, Mathilde M.; Dirksen, Asger [Gentofte Hospital, Department of Respiratory Medicine, Hellerup (Denmark); Riel, Sarah J. van; Jacobs, Colin; Scholten, Ernst T.; Ginneken, Bram van [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Saghir, Zaigham [Herlev Hospital, Department of Respiratory Medicine, Herlev (Denmark); Pedersen, Jesper Holst [Copenhagen University Hospital, Department of Thoracic Surgery, Rigshospitalet, Koebenhavn Oe (Denmark); Hohwue Thomsen, Laura [Hvidovre Hospital, Department of Respiratory Medicine, Hvidovre (Denmark); Skovgaard, Lene T. [University of Copenhagen, Department of Biostatistics, Koebenhavn Oe (Denmark)

    2015-10-15

    Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination. AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor. (orig.)

  15. 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.

  16. Utilization of spent dregs for the production of activated carbon for CO2 adsorption

    Directory of Open Access Journals (Sweden)

    Serafin Jarosław

    2017-06-01

    Full Text Available The objective of this work was preparation of activated carbon from spent dregs for carbon dioxide adsorption. A saturated solution of KOH was used as an activating agent. Samples were carbonized in the furnace at the temperature of 550°C. Textural properties of activated carbons were obtained based on the adsorption-desorption isotherms of nitrogen at −196°C and carbon dioxide at 0°C. The specific surface areas of activated carbons were calculated by the Brunauer – Emmett – Teller equation. The volumes of micropores were obtained by density functional theory method. The highest CO2 adsorption was 9.54 mmol/cm3 at 0°C – and 8.50 mmol/cm3 at 25°C.

  17. 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)

  18. Adsorption of SO2 on bituminous coal char and activated carbon fiber prepared from phenol formaldehyde

    Science.gov (United States)

    DeBarr, Joseph A.; Lizzio, Anthony A.; Daley, Michael A.

    1996-01-01

    Carbon-based materials are used commercially to remove SO2 from coal combustion flue gases. Historically, these materials have consisted of granular activated carbons prepared from lignite or bituminous coal. Recent studies have reported that activated carbon fibers (ACFs) may have potential in this application due to their relatively high SO2 adsorption capacity. In this paper, a comparison of SO2 adsorption for both coal-based carbons and ACFs is presented, as well as ideas on carbon properties that may influence SO2 adsorption

  19. Developing low-cost carbon-based sorbents for Hg capture from flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Perry, R.; Lakatos, J.; Snape, C.E.; Sun, C. [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre

    2005-07-01

    To help reduce the cost of Hg capture from flue gas a number of low-cost carbons are being investigated, including activated tyre char and PFA carbon, in conjunction with some of the pre-treatments that have been found to be effective for commercial actived carbons. Experimental conditions for screening the sorbents have been selected to determine breakthrough capacities rapidly. The unactivated carbons have low breakthrough capacities under the test conditions employed (around 0.1 mg g{sup -1}) but these improve upon steam activation (around 0.25 mg g{sup -1}) but are still lower than those of non-impregnated commercial activated carbons (around 0.4-0.7 mg g{sup -1}), due to their lower surface areas. Comparable improvements to the commercial carbons have been achieved for impregnation treatments, including sulfur and bromine. However, certain gasification chars do have much higher breakthrough capacities than commercial carbons used for flue gas injection. Manganese oxide impregnation with low concentration is particularly effective for the activated and unactivated carbons giving breakthrough capacities comparable to the commercial carbons. Pointers for further increasing breakthrough and equilibrium capacities for carbon-based sorbents are discussed. 7 refs., 1 fig., 3 tabs.

  20. Modification of polystyrene-based activated carbon spheres to improve adsorption of dibenzothiophene

    Science.gov (United States)

    Wang, Qin; Liang, Xiaoyi; Qiao, Wenming; Liu, Chaojun; Liu, Xiaojun; Zhang, Rui; Ling, Licheng

    2009-01-01

    Polystyrene-based activated carbon spheres (PACS) were modified with either air, HNO 3, (NH 4) 2S 2O 8, H 2O 2 or H 2 to improve their adsorption properties of dibenzothiophene (DBT). The texture and surface chemistry of PACS were characterized by N 2 adsorption, scanning electron microscopy (SEM), temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), acid-base titration and elemental analysis. The results showed that HNO 3 and (NH 4) 2S 2O 8 treatments introduced large amount of acidic groups such as carboxylic, lactones and anhydride groups, while air and H 2O 2 had relatively mild effects and introduced a small quantity of phenol, carbonyl and ether groups. In the HNO 3 treatment, the acidic groups might be fixed on the internal and external surface of PACS, which may act as active sites of adsorption, resulting in increase of the adsorption amount by 45%. Whereas H 2O 2 and (NH 4) 2S 2O 8 treatments might fix more oxygen-containing groups on the external surface, which may hinder DBT molecule enter into micropores, leading to rather lower adsorption capacity with the extent of oxidation. So, the concentration, distribution and types of the acidic functional groups are responsible for the removal of DBT.

  1. 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

  2. Carbon Based Nanotechnology: Review

    Science.gov (United States)

    Srivastava, Deepak; Saini, Subhash (Technical Monitor)

    1999-01-01

    This presentation reviews publicly available information related to carbon based nanotechnology. Topics covered include nanomechanics, carbon based electronics, nanodevice/materials applications, nanotube motors, nano-lithography and H2O storage in nanotubes.

  3. Use of grape must as a binder to obtain activated carbon briquettes

    Directory of Open Access Journals (Sweden)

    Deiana A. C.

    2004-01-01

    Full Text Available The results of studies on briquetting activated-carbon-based adsorbent materials, prepared from raw materials from the region of Cuyo, Argentina, are reported in this article. Several steps were carried out to obtain activated-carbon briquettes from Eucalyptus camaldulensis Dehn wood. These steps included carbonization of wood to obtain char; blending of char and a novel binder, i.e., grape must; formation of cylinder-like briquettes by pressure; and activation of the resulting material. The material was activated with steam under different temperatures, activation times, and activating agent flow rates. Impact resistance index, axial compressive strength, tensile strength by diametrical compression, BET area, and pore volume were measured for product characterization. Satisfactory surface areas and mechanical strengths were found in the final products.

  4. Efficient oligonucleotide probe selection for pan-genomic tiling arrays

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2009-09-01

    Full Text Available Abstract Background Array comparative genomic hybridization is a fast and cost-effective method for detecting, genotyping, and comparing the genomic sequence of unknown bacterial isolates. This method, as with all microarray applications, requires adequate coverage of probes targeting the regions of interest. An unbiased tiling of probes across the entire length of the genome is the most flexible design approach. However, such a whole-genome tiling requires that the genome sequence is known in advance. For the accurate analysis of uncharacterized bacteria, an array must query a fully representative set of sequences from the species' pan-genome. Prior microarrays have included only a single strain per array or the conserved sequences of gene families. These arrays omit potentially important genes and sequence variants from the pan-genome. Results This paper presents a new probe selection algorithm (PanArray that can tile multiple whole genomes using a minimal number of probes. Unlike arrays built on clustered gene families, PanArray uses an unbiased, probe-centric approach that does not rely on annotations, gene clustering, or multi-alignments. Instead, probes are evenly tiled across all sequences of the pan-genome at a consistent level of coverage. To minimize the required number of probes, probes conserved across multiple strains in the pan-genome are selected first, and additional probes are used only where necessary to span polymorphic regions of the genome. The viability of the algorithm is demonstrated by array designs for seven different bacterial pan-genomes and, in particular, the design of a 385,000 probe array that fully tiles the genomes of 20 different Listeria monocytogenes strains with overlapping probes at greater than twofold coverage. Conclusion PanArray is an oligonucleotide probe selection algorithm for tiling multiple genome sequences using a minimal number of probes. It is capable of fully tiling all genomes of a species on

  5. On linearity of pan-integral and pan-integrable functions space

    Czech Academy of Sciences Publication Activity Database

    Ouyang, Y.; Li, J.; Mesiar, Radko

    2017-01-01

    Roč. 90, č. 1 (2017), s. 307-318 ISSN 0888-613X Institutional support: RVO:67985556 Keywords : linearity * monotone measure * Pan-integrable space Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 2.845, year: 2016 http://library.utia.cas.cz/separaty/2017/E/mesiar-0477549.pdf

  6. ATLAS World-cloud and networking in PanDA

    CERN Document Server

    Barreiro Megino, Fernando Harald; The ATLAS collaboration; De, Kaushik; Di Girolamo, Alessandro; Walker, Rodney

    2016-01-01

    The ATLAS computing model was originally designed as static clouds (usually national or geographical groupings of sites) around the Tier 1 centers, which confined tasks and most of the data traffic. Since those early days, the sites' network bandwidth has increased at O(1000) and the difference in functionalities between Tier 1s and Tier 2s has reduced. After years of manual, intermediate solutions, we have now ramped up to full usage of World-cloud, the latest step in the PanDA Workload Management System to increase resource utilization on the ATLAS Grid, for all workflows (MC production, data (re)processing, etc.). We have based the development on two new site concepts. Nuclei sites are the Tier 1s and large Tier 2s, where tasks will be assigned and the output aggregated, and satellites are the sites that will execute the jobs and send the output to their nucleus. Nuclei and satellite sites are dynamically paired by PanDA for each task based on the input data availability, capability matching, site load and...

  7. ATLAS WORLD-cloud and networking in PanDA

    CERN Document Server

    AUTHOR|(SzGeCERN)643806; The ATLAS collaboration; De, Kaushik; Di Girolamo, Alessandro; Maeno, Tadashi; Walker, Rodney

    2017-01-01

    The ATLAS computing model was originally designed as static clouds (usually national or geographical groupings of sites) around the Tier 1 centres, which confined tasks and most of the data traffic. Since those early days, the sites' network bandwidth has increased at 0(1000) and the difference in functionalities between Tier 1s and Tier 2s has reduced. After years of manual, intermediate solutions, we have now ramped up to full usage of World-cloud, the latest step in the PanDA Workload Management System to increase resource utilization on the ATLAS Grid, for all workflows (MC production, data (re)processing, etc.). We have based the development on two new site concepts. Nuclei sites are the Tier 1s and large Tier 2s, where tasks will be assigned and the output aggregated, and satellites are the sites that will execute the jobs and send the output to their nucleus. PanDA dynamically pairs nuclei and satellite sites for each task based on the input data availability, capability matching, site load and network...

  8. 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.

  9. Modeling equilibrium adsorption of organic micropollutants onto activated carbon

    KAUST Repository

    De Ridder, David J.

    2010-05-01

    Solute hydrophobicity, polarizability, aromaticity and the presence of H-bond donor/acceptor groups have been identified as important solute properties that affect the adsorption on activated carbon. However, the adsorption mechanisms related to these properties occur in parallel, and their respective dominance depends on the solute properties as well as carbon characteristics. In this paper, a model based on multivariate linear regression is described that was developed to predict equilibrium carbon loading on a specific activated carbon (F400) for solutes reflecting a wide range of solute properties. In order to improve prediction accuracy, groups (bins) of solutes with similar solute properties were defined and solute removals were predicted for each bin separately. With these individual linear models, coefficients of determination (R2) values ranging from 0.61 to 0.84 were obtained. With the mechanistic approach used in developing this predictive model, a strong relation with adsorption mechanisms is established, improving the interpretation and, ultimately, acceptance of the model. © 2010 Elsevier Ltd.

  10. Physico-chemical characteristics of activated carbons based on a copolymer of furfural and mineral raw materials of the Republic of Kazakhstan and their application in extracting gold from industrial solutions

    Directory of Open Access Journals (Sweden)

    Kanagat Kishibayev

    2013-09-01

    Full Text Available Activated carbons are widely used in different industries for cleaning a variety of natural objects from of technogenic pollutants. In the article presents the results of physico-chemical investigations of activated carbons. The investigations on the sorption of gold in cyanide solutions activated sorbent based on furfural and sorbent based on shungit.

  11. Pan-Arctic concentrations of mercury and stable isotope ratios of carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) in marine zooplankton

    Energy Technology Data Exchange (ETDEWEB)

    Pomerleau, Corinne, E-mail: corinne.pomerleau@umanitoba.ca [Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Greenland Institute of Natural Resources, Kivioq 2, Nuuk 3900, Greenland (Denmark); Stern, Gary A.; Pućko, Monika [Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Foster, Karen L. [Foster Environmental, Peterborough, ON K9J 8L2 (Canada); Macdonald, Robie W. [Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, BC V8L 4B2 (Canada); Fortier, Louis [Québec-Océan, Département de Biologie, Université Laval, Québec, QC G1V 0A6 (Canada)

    2016-05-01

    Zooplankton play a central role in marine food webs, dictating the quantity and quality of energy available to upper trophic levels. They act as “keystone” species in transfer of mercury (Hg) up through the marine food chain. Here, we present the first Pan-Arctic overview of total and monomethylmercury concentrations (THg and MMHg) and stable isotope ratios of carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) in selected zooplankton species by assembling data collected between 1998 and 2012 from six arctic regions (Laptev Sea, Chukchi Sea, southeastern Beaufort Sea, Canadian Arctic Archipelago, Hudson Bay and northern Baffin Bay). MMHg concentrations in Calanus spp., Themisto spp. and Paraeuchaeta spp. were found to increase with higher δ{sup 15}N and lower δ{sup 13}C. The southern Beaufort Sea exhibited both the highest THg and MMHg concentrations. Biomagnification of MMHg between Calanus spp. and two of its known predators, Themisto spp. and Paraeuchaeta spp., was greatest in the southern Beaufort Sea. Our results show large geographical variations in Hg concentrations and isotopic signatures for individual species related to regional ecosystem features, such as varying water masses and freshwater inputs, and highlight the increased exposure to Hg in the marine food chain of the southern Beaufort Sea. - Highlights: • Assessment of Pan-Arctic variability in zooplankton Hg concentrations • Increased exposure to Hg in the marine food chain of the southern Beaufort Sea • Zooplankton plays a central role in the Hg pathway within Arctic marine food webs.

  12. High power density supercapacitors based on the carbon dioxide activated D-glucose derived carbon electrodes and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid

    Science.gov (United States)

    Tooming, T.; Thomberg, T.; Kurig, H.; Jänes, A.; Lust, E.

    2015-04-01

    The electrochemical impedance spectroscopy, cyclic voltammetry, constant current charge/discharge and the constant power discharge methods have been applied to establish the electrochemical characteristics of the electrical double-layer capacitor (EDLC) consisting of the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) ionic liquid and microporous carbon electrodes. Microporous carbon material used for preparation of electrodes (GDAC - glucose derived activated carbon), has been synthesised from D-(+)-glucose by the hydrothermal carbonization method, including subsequent pyrolysis, carbon dioxide activation and surface cleaning step with hydrogen. The Brunauer-Emmett-Teller specific surface area (SBET = 1540 m2 g-1), specific surface area calculated using the non-local density functional theory in conjunction with stable adsorption integral equation using splines (SAIEUS) model SSAIEUS = 1820 m2 g-1, micropore surface area (Smicro = 1535 m2 g-1), total pore volume (Vtot = 0.695 cm3 g-1) and the pore size distribution were obtained from the N2 sorption data. The SBET, Smicro and Vtot values have been correlated with the electrochemical characteristics strongly dependent on the carbon activation conditions applied for EDLCs. Wide region of ideal polarizability (ΔV ≤ 3.2 V), very short charging/discharging time constant (2.7 s), and high specific series capacitance (158 F g-1) have been calculated for the optimized carbon material GDAC-10h (activation of GDAC with CO2 during 10 h) in EMImBF4 demonstrating that this system can be used for completing the EDLC with high energy- and power densities.

  13. A Review on Adsorption of Cationic Dyes using Activated Carbon

    Directory of Open Access Journals (Sweden)

    Corda Nikita Chrishel

    2018-01-01

    Full Text Available In this article efficiency of activated carbon as a potent adsorbent of cationic dyes has been reviewed. Non-biodegradable nature of pollutants and their removal in the present generation is a great challenge. Therefore, extensive study on adsorption of these classes of pollutants from water bodies is being carried out. Methylene blue (majorly a dye seen in the effluent streams of textile, printing, paper industries along with some of the commonly used cationic dyes in process industries and their sorption on activated carbon are reviewed here. High cost of commercially activated carbon which is a limitation to its extensive use have paved way for study of adsorption by naturally obtained and extracted activated carbon from agricultural wastes and various other sources. The purpose of this review paper is to summarize the available information on the removal of cationic dyes using naturally extracted and commercially obtained activated carbon. Various parameters such as temperature, initial dye concentration, pH, contact time, adsorbent dosage, particle size, stirring, agitation etc. were studied and the optimum parameters were determined based on the experimental outcomes. Equilibrium data was examined using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich and few other isotherm models. Kinetic studies also have been carried out to find the most suitable way of expressing the adsorption process.

  14. 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)

  15. 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.

  16. 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

  17. 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.

  18. Improvement of the cycling performance of LiCoO2 with assistance of cross-linked PAN for lithium ion batteries

    International Nuclear Information System (INIS)

    Yang, Xinhe; Shen, Lanyao; Wu, Bin; Zuo, Zicheng; Mu, Daobin; Wu, Borong; Zhou, Henghui

    2015-01-01

    Highlights: • Cross-linked PAN coating was prepared without damaging the surface of LiCoO 2 . • The coating layer owns good electronic conductivity and mechanical strength. • The cross-linked PAN coating layer is more sufficient than Al 2 O 3 coating. • It shows much improved cyclability than that of bare and Al 2 O 3 coated LiCoO 2 . - Abstract: LiCoO 2 has been widely used in lithium ion batteries for digital electronic products. However, the limited cycling performance under high cut-off voltage hinders its commercial application. Many metal oxides and/or phosphorus coating have been reported to improve the cycling performance of LiCoO 2 . In this paper, we report on cross-linked PAN coated LiCoO 2 composite as a cathode material for lithium ion batteries. The coating layer was obtained by intermolecular crosslinking of PAN polymer chain by heat treatment at high temperature in air. The air heating process avoids the possible damage arising from the carbon thermal reduction to the surface structure of LiCoO 2 . Electrochemical test indicates that the LiCoO 2 with the cross-linked PAN coating layer shows much improved cycle performance compared with that of bare and Al 2 O 3 coated LiCoO 2 . These findings might also open new avenues to explore polymer coating for other cathode materials of lithium ion batteries

  19. 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)

  20. Preparation and investigation of ion exchange properties of sorbent based on activated carbon BAU and zirconium hydroxide

    International Nuclear Information System (INIS)

    Blokhin, A.A.; Semenov, M.I.; Taushkanov, V.P.; Andronov, E.A.

    1978-01-01

    The method of obtaining the sorbent based on the activated carbon and zirconium hydroxide, performed by carbon soaking by zirconium salt solution, hydrolytic decomposition, being in salt pores by ammonia solution and drying of the obtained sorbet in the air at the temperature of 105-115 deg. The kinetic characteristics of the obtained sorbent in the wide range of pH value of solutions are studied; sodium, chloride, fluoride and phosphate ion sorbtion taken as examples. A high selectivity of the sorbent to phosphate and fluoride ions has been established. The usefullness of the obtained sorbent for extraction of phosphorus microquantities from 1M sodium chloride solution and its concentration at the elution stage is shown

  1. Activated Carbon Preparation and Modification for Adsorption

    Science.gov (United States)

    Cao, Yuhe

    compared to charcoal-based commercial AC (143.8 mg g -1). Based on the adsorption experiments of butanol vapor, we found the chemical properties of the AC surface play an important role in adsorbing molecules. The adsorption of creatinine on active carbons was also studied, which is a toxic compound generated by human. High levels of creatinine in the blood stream is normally caused by malfunction or failure of the kidneys. Activated carbons is taken by the patients orally to reduce creatinine level. In order to figure out whether chemical modification could increase the adsorption capacity of creatinine, AC samples modified by nitric acid hydrothermal modification were assessed for their ability to adsorb creatinine. The pore structure and surface properties of the AC samples were characterized by N 2 adsorption, temperature programmed desorption (TPD), Fourier Transform Infrared spectroscopy (FTIR), and X-ray photoelectron spectrometer (XPS). It indicated that 4M HNO3 hydrothermal modification with 180 °C was an efficient method in improvement of the creatinine adsorption. The improved adsorption capacity can be attributed mainly to an increase in the acidic oxygen-containing functional groups. The adsorption of creatinine over AC may involve an interaction with the acidic oxygen-containing groups on AC. Langmuir and Freundlich adsorption models were applied to describe the experimental isotherm and isotherm constants. Equilibrium data fitted very well to the Freundlich model in the entire saturation range (3.58-59.08 mg L-1 ). The maximum adsorption capacities of AC modified with 180 °C is 62.5 mg g-1 according to the Langmuir model. Pseudo first-order and second-order kinetic models were used to describe the kinetic data and the rate constants were evaluated. The experimental data fitted well to the second-order kinetic model, which indicates that the chemical adsorption was the rate-limiting step, instead of mass transfer. (Abstract shortened by ProQuest.).

  2. 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)

  3. Nuclear security in major public events: the XV Pan American Games and the III Para-Pan American Games in Brazil

    International Nuclear Information System (INIS)

    Mello, Luiz A. de; Monteiro Filho, Joselio S.; Belem, Lilia M.J.; Torres, Luiz F.B.

    2009-01-01

    The organization of a major public event involving large numbers of spectators and participants, presents important security challenges. Taking this into consideration, the Brazilian Nuclear Energy Commission (CNEN) has been requested, by the National Secretary of Public Security/ Ministry of Justice (SENASP/MJ), by the end of 2006, to participate on the security actions to be implemented in both the XV Pan American Games and III Para Pan American Games. The XV Pan American Games 2007 and the III Para Pan American Games were held in Rio de Janeiro, Brazil from 13 to 29 July 2007 and from 12 to 19 August 2007, respectively. Those events had 8700 participants between athletes, coaches and referees from 42 countries. More than 300 competition events were held at 17 different venues and were covered by 4910 professionals from TV, radio and written press. Around 2 million tickets have been sold or distributed and 18,000 volunteers participated on the organization. The participation of CNEN was concentrated on the implementation of specific nuclear and radiological security measures to be applied at those events. This was part of a multi-institutional plan for the security of the Games, coordinated by the National Secretary of Public Security of the Ministry of Justice (SENASP/MJ). The support provided by IAEA under a Cooperation Arrangement with the Brazilian authorities was a key factor for the success of the whole operation. The actions taken and the lessons identified by the Brazilian Nuclear Energy Commission related to nuclear and radiological security for the Pan American Games and for the Para Pan American Games are presented. (author)

  4. 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.)

  5. Development of highly microporous activated carbon from the alcoholic beverage industry organic by-products

    International Nuclear Information System (INIS)

    Nieto-Delgado, C.; Terrones, M.; Rangel-Mendez, J.R.

    2011-01-01

    This work has the aim to employ the agave bagasse, a waste from Tequila and Mescal industries, to obtain a product of high commercial value such as activated carbon. The activated carbon production methodology was based on a chemical activation, by using ZnCl 2 and H 3 PO 4 as activating agent and agave bagasse as a natural source of carbon. The activation temperature (150-450 o C), activation time (0-60 min) and weight ratio of activating agent to precursor (0.2-4) were studied. The produced carbon materials were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and nitrogen physisorption at -196 o C. In addition, the activating agent recovery was evaluated. We were able to obtain highly microporous activated carbons with micropore volumes between 0.24 and 1.20 cm 3 /g and a surface area within 300 and 2139 m 2 /g. These results demonstrated the feasibility to treat the industrial wastes of the Tequila and Mescal industries, being this wastes an excellent precursor to produce highly microporous activated carbons that can be processed at low activation temperatures in short times, with the possibility of recycling the activating agent.

  6. Pan Genome of the Phytoplankton Emiliania Underpins its Global Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Read, Betsy A. [California State Univ. (CalState), San Marcos, CA (United States); Kegel, Jessica [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Klute, Mary J. [Univ. of Alberta, Edmonton, AB (Canada); Kuo, Alan [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Lefebvre, Stephane C. [J. Craig Venter Inst., San Diego, CA (United States); Maumus, Florian [National Institute of Agricultural Research, Versailles (France); Mayer, Christoph [Alexander Koenig Research Museum, Bonn (Germany); Ruhr Univ., Bochum (Germany); Miller, John [Univ. of Maryland, College Park, MD (United States); Monier, Adam [Monterey Bay Aquarium Research Inst., Moss Landing, CA (United States); Salamov, Asaf [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Young, Jeremy [Univ. College London (United Kingdom); Aguilar, Maria [Univ. of Alberta, Edmonton, AB (Canada); Claverie, Jean-Michel [Aix-Marseille Univ. (France); Frickenhaus, Stephan [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Univ. of Bremerhaven (Germany); Gonzalez, Karina [Harvard Medical School, Boston, MA (United States); Herman, Emily K. [Univ. of Alberta, Edmonton, AB (Canada); Lin, Yao-Cheng [Ghent Univ. (Belgium); Napier, Johnathan [Rothamstead Research, Harpenden (United Kingdom); Ogata, Hiroyuki [Aix-Marseille Univ. (France); Sarno, Analissa F. [California State Univ. (CalState), San Marcos, CA (United States); Schmutz, Jeremy [USDOE Joint Genome Inst., Walnut Creek, CA (United States); HudsonAlpha Genome Sequencing Center, Huntsville, AL (United States); Schroeder, Declan [Marine Biological Association of the UK, Plymouth (United Kingdom); de Vargas, Columban [CNRS. Univ. Pierre and Marie Curie (France).; Verret, Frederic [Univ. of Essex, Colchester (United Kingdom); von Dassow, Peter [Pontifical Catholic University of Chile, Santiago (Chile); Valentin, Klaus [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Van de Peer, Yves [Ghent Univ. (Belgium); Wheeler, Glen [Marine Biological Association of the UK, Plymouth (United Kingdom); Plymouth Marine Lab. (United Kingdom); Annotation Consortium, Emiliania huxleyi; Dacks, Joel B. [Univ. of Alberta, Edmonton, AB (Canada); Delwiche, Charles F. [Univ. of Maryland, College Park, MD (United States); Dyhrman, Sonya T. [Woods Hole Oceanographic Inst., MA (United States); Columbia Univ., Palisades, NY (United States); Glockner, Gernot [Univ. of Cologne (Germany); John, Uwe [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Richards, Thomas [National History Museum, London (United Kingdom); Worden, Alexandra Z. [Monterey Bay Aquarium Research Inst., Moss Landing, CA (United States); Zhang, Xiaoyu [California State Univ. (CalState), San Marcos, CA (United States); Grigoriev, Igor V. [USDOE Joint Genome Inst., Walnut Creek, CA (United States)

    2012-06-18

    Coccolithophores have influenced the global climate for over 200 million years1. These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems2. They form blooms that can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering themvisible fromspace3.Although coccolithophores export carbon in the form of organic matter and calcite to the sea floor, they also release CO2 in the calcification process. Hence, they have a complex influence on the carbon cycle, driving either CO2 production or uptake, sequestration and export to the deep ocean4. Here we report the first haptophyte reference genome, from the coccolithophore Emiliania huxleyi strain CCMP1516, and sequences from 13 additional isolates. Our analyses reveal a pan genome (core genes plus genes distributed variably between strains) probably supported by an atypical complement of repetitive sequence in the genome. Comparisons across strains demonstrate thatE. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires. Genome variability within this species complex seems to underpin its capacity both to thrive in habitats ranging from the equator to the subarctic and to form large-scale episodic blooms under a wide variety of environmental conditions.

  7. Dynamic analysis of pan evaporation variations in the Huai River Basin, a climate transition zone in eastern China.

    Science.gov (United States)

    Li, Meng; Chu, Ronghao; Shen, Shuanghe; Islam, Abu Reza Md Towfiqul

    2018-06-01

    Pan evaporation (E pan ), which we examine in this study to better understand atmospheric evaporation demand, represents a pivotal indicator of the terrestrial ecosystem and hydrological cycle, particularly in the Huai River Basin (HRB) in eastern China, where high potential risks of drought and flooding are commonly observed. In this study, we examine the spatiotemporal trend patterns of climatic factors and E pan by using the Mann-Kendall test and the Theil-Sen estimator based on a daily meteorological dataset from 89 weather stations during 1965-2013 in the HRB. Furthermore, the PenPan model is employed to estimate E pan at a monthly time scale, and a differential equation method is applied to quantify contributions from four meteorological variables to E pan trends. The results show that E pan significantly decreased (P<0.001) at an average rate of -8.119mm·a -2 at annual time scale in the whole HRB, with approximately 90% of stations occupied. Meanwhile, the generally higher E pan values were detected in the northern HRB. The values of the aerodynamic components in the PenPan model were much greater than those of the radiative components, which were responsible for the variations in the E pan trend. The significantly decreasing wind speed (u 2 ) was the most dominant factor that controlled the decreasing E pan trend at each time scale, followed by the notable decreasing net radiation (R n ) at the annual time scale also in growing season and summer. However, the second dominant factor shifted to the mean temperature (T a ) during the spring and winter and the vapor pressure deficit (vpd) during the autumn. These phenomena demonstrated a positive link between the significance of climate variables and their control over the E pan trend. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. 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.

  9. Thermal analysis of physical and chemical changes occuring during regeneration of activated carbon

    Directory of Open Access Journals (Sweden)

    Radić Dejan B.

    2017-01-01

    Full Text Available High-temperature thermal process is a commercial way of regeneration of spent granular activated carbon. The paper presents results of thermal analysis conducted in order to examine high-temperature regeneration of spent activated carbon, produced from coconut shells, previously used in drinking water treatment. Results of performed thermogravimetric analysis, derivative thermogravimetric analysis, and differential thermal analysis, enabled a number of hypotheses to be made about different phases of activated carbon regeneration, values of characteristic parameters during particular process phases, as well as catalytic impact of inorganic materials on development of regeneration process. Samples of activated carbon were heated up to 1000°C in thermogravimetric analyser while maintaining adequate oxidizing or reducing conditions. Based on diagrams of thermal analysis for samples of spent activated carbon, temperature intervals of the first intense mass change phase (180-215°C, maximum of exothermic processes (400-450°C, beginning of the second intense mass change phase (635-700°C, and maximum endothermic processes (800-815°C were deter-mined. Analysing and comparing the diagrams of thermal analysis for new, previously regenerated and spent activated carbon, hypothesis about physical and chemical transformations of organic and inorganic adsorbate in spent activated carbon are given. Transformation of an organic adsorbate in the pores of activated carbon, results in loss of mass and an exothermic reaction with oxygen in the vapour phase. The reactions of inorganic adsorbate also result the loss of mass of activated carbon during its heating and endothermic reactions of their degradation at high temperatures.

  10. Porous core-shell carbon fibers derived from lignin and cellulose nanofibrils

    KAUST Repository

    Xu, Xuezhu

    2013-10-01

    This letter reports a method to produce lignin and cellulose nanofibrils (CNFs) based porous core-shell carbon fibers via co-electrospinning followed by controlled carbonization. Lignin formed the shell of the fiber while CNF network formed the porous core. Polyacrylonitrile (PAN) was added to the lignin solution to increase its electrospinability. CNFs were surface acetylated and dispersed in silicon oil to obtain a homogenous dispersion for electrospinning the porous core. Hollow lignin fibers were also electrospun using glycerin as the core material. FT-IR measurements confirmed the CNF acetylation. SEM micrographs showed the core-shell and hollow fiber nanostructures before and after carbonization. The novel carbon fibers synthesized in this study exhibited increased surface area and porosity that are promising for many advanced applications. © 2013 Elsevier B.V.

  11. Porous core-shell carbon fibers derived from lignin and cellulose nanofibrils

    KAUST Repository

    Xu, Xuezhu; Zhou, Jian; Jiang, Long; Lubineau, Gilles; Chen, Ye; Wu, Xiangfa; Piere, Robert

    2013-01-01

    This letter reports a method to produce lignin and cellulose nanofibrils (CNFs) based porous core-shell carbon fibers via co-electrospinning followed by controlled carbonization. Lignin formed the shell of the fiber while CNF network formed the porous core. Polyacrylonitrile (PAN) was added to the lignin solution to increase its electrospinability. CNFs were surface acetylated and dispersed in silicon oil to obtain a homogenous dispersion for electrospinning the porous core. Hollow lignin fibers were also electrospun using glycerin as the core material. FT-IR measurements confirmed the CNF acetylation. SEM micrographs showed the core-shell and hollow fiber nanostructures before and after carbonization. The novel carbon fibers synthesized in this study exhibited increased surface area and porosity that are promising for many advanced applications. © 2013 Elsevier B.V.

  12. Natural gas adsorption on biomass derived activated carbons: A mini review

    Directory of Open Access Journals (Sweden)

    Hamza Usman D.

    2016-01-01

    Full Text Available Activated carbon materials are good candidates for natural gas storage due excellent textural properties that are easy to enhance and modify. Natural gas is much cleaner fuel than coal and other petroleum derivatives. Storage of natural gas on porous sorbents at lower pressure is safer and cheaper compared to compressed and liquefied natural gas. This article reviews some works conducted on natural gas storage on biomass based activated carbon materials. Methane storage capacities and deliveries of the various sorbents were given. The effect of factors such as surface area, pore characteristic, heat of adsorption, packing density on the natural gas storage capacity on the activated carbons are discussed. Challenges, improvements and future directions of natural gas storage on porous carbonaceous materials are highlighted.

  13. 75 FR 61698 - Federal Consistency Appeal by Pan American Grain Co.

    Science.gov (United States)

    2010-10-06

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Federal Consistency Appeal by Pan American Grain Co. AGENCY: National Oceanic and Atmospheric Administration (NOAA), Department... Commerce (Secretary) by Pan American Grain Co. (Pan American) has closed. No additional information, briefs...

  14. Adsorption characteristics of Bisphenol-A on tailored activated carbon in aqueous solutions.

    Science.gov (United States)

    Yan, Liang; Lv, Di; Huang, Xinwen; Shi, Huixiang; Zhang, Geshan

    2016-10-01

    The adsorption behavior of pharmaceuticals and personal care product, Bisphenol-A (BPA), according to four coal-based and four wood-based granular activated carbons modified using outgassing treatment, acidic treatment or alkaline treatment was studied. The adsorption isotherm results indicated that carbon surface acidity played a very important role in the adsorption of BPA. It was found that increasing surface acidity would increase the hydrogen bonding effects and increase adsorption of BPA on activated carbon. The acidic modified sample (F600-A and OLC-A) represented the best adsorption capacity, and the equilibrium adsorption amounts reached 346.42 and 338.55 mg/g, respectively. Further, effects of surface charge and surface basicity were examined. It was found that the adsorbed amount of BPA decreased with the increase of surface charge. Finally, there appeared to be a significant oligomerization phenomenon with BPA molecules onto the surface of activated carbon. OLC and OLC-OG, which have higher micropore percentages, are very effective in hampering the oligomerization of BPA under oxic conditions.

  15. Adsorption of aqueous Cd(II) and Pb(II) on activated carbon nanopores prepared by chemical activation of doum palm shell.

    Science.gov (United States)

    Gaya, Umar Ibrahim; Otene, Emmanuel; Abdullah, Abdul Halim

    2015-01-01

    Non-uniformly sized activated carbons were derived from doum palm shell, a new precursor, by carbonization in air and activation using KOH, NaOH and ZnCl2. The activated carbon fibres were characterised by X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, particle size analysis and evaluated for Cd(II) and Pb(II) removal. The 40-50 nm size, less graphitic, mesoporous NaOH activated carbon yielded high adsorption efficiency, pointing largely to the influence surface area. The performance of the KOH based activated carbon was arguably explained for the first time in terms of crystallinity. The efficiencies of the mesoporous ZnCl2-formulated activated carbon diminished due to the presence of larger particles. Batch adsorption of divalent metals revealed dependence on adsorbent dose, agitation time, pH and adsorbate concentrations with high adsorption efficiencies at optimum operating parameters. The equilibrium profiles fitted Langmuir and Freundlich isotherms, and kinetics favoured pseudo-second order model. The study demonstrated the practicability of the removal of alarming levels of cadmium and lead ions from industrial effluents.

  16. Mesoporous carbon design for ionic liquid-based, double-layer supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Lazzari, M.; Soavi, F.; Mastragostino, M. [Dipartimento di Scienza dei Metalli, Elettrochimica e Tecniche Chimiche, University of Bologna (Italy)

    2010-10-15

    The use of pyrrolidinium-based ionic liquids (ILs) in asymmetric electric double-layer capacitors (AEDLC) with positive and negative carbon electrodes of different weight is a powerful strategy for developing safe, high specific-energy supercapacitors operating at >3.5 V. The preparation and characterisation of ordered (OTC) and disordered (DTC) template carbons, the latter obtained by a fast and low-cost method, are reported. The porosity and capacitance features of the template carbons are discussed in view of their application in IL-based AEDLCs and compared with the properties of aero/cryo/xerogel carbons and a commercial activated carbon. The performance of an N-butyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide-based AEDLC assembled with DTC carbon electrodes operating at 3.9 V featuring high specific energy of 47 Wh kg{sup -1} is then reported. The impact of porosity and surface chemistry of carbons on the electrode capacitive response in IL and on the performance of the IL-based AEDLC in terms of energy, power and weight distribution of module components is discussed. The effect of IL nature and carbon porosity on the time constant of the double-layer charging process was also investigated by voltammetric and impedance studies. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  17. Carbon-Based Nanomaterials: Multi-Functional Materials for Biomedical Engineering

    Science.gov (United States)

    Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R.; Khademhosseini, Ali

    2013-01-01

    Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications. PMID:23560817

  18. Electrocatalytic activity of Pt grown by ALD on carbon nanotubes for Si-based DMFC applications

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte; Dalslet, Bjarke Thomas; Yang, R.B.

    2012-01-01

    in a top-flow ALD reactor at 250°C, using MeCpPtMe3 and O2 as precursors. The anode was tested for the methanol oxidation reaction (MOR) in a three-electrode electrochemical set-up and it showed improved catalytic activity compared to a reference sample of Pt deposited on flat Si. It is demonstrated......We present an anode design for silicon-based direct methanol fuel cell (DMFC) applications. Platinum was deposited conformally by atomic layer deposition (ALD) onto vertically aligned, nitrogendoped multi-walled carbon nanotubes (MWCNTs) grown on porous silicon. The deposition was carried out...... that ALD could be a MEMS compatible deposition technique for Si-based fuel cell applications. © The Electrochemical Society....

  19. The Pan-STARRS1 Surveys

    Science.gov (United States)

    Chambers, Kenneth; Pan-STARRS Team

    2018-01-01

    The Pan-STARRS1 Surveys are complete and the first data release, DR1, is available from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The data include a database of measured attributes of 3 billion objects, stacked images, and metadata of the 3pi Steradian Survey. The DR1 contains all stationary objects with mean and stack photometry registered on the GAIA astrometric frame. DR2 is in preparation and will be released this winter with all the individual epoch images and time domain photometry and forced photometry on the individual epoch images. The characteristics of the Pan-STARRS1 Surveys will be presented, including image quality, depth, cadence, and coverage. Measured attributes include PSF model magnitudes, aperture magnitudes, Kron Magnitudes, radial moments, Petrosian magnitudes, DeVaucoulers, Exponential, and Sersic magnitudes for extended objects. Images include total intensity, variance, and masks.An overview of the Pan-STARRS1 Surveys and data releases will be presented together with a brief description of the data collected since the end of the PS1 Science Consortium surveys, and the plans for the upcoming survey with PS1 and PS2 begining in February 2018.

  20. Porosity and adsorption properties of activated carbon derived from palm oil waste

    International Nuclear Information System (INIS)

    Che Seman Mahmood; Nor Hayati Alias; Choo Thye Foo; Megat Harun Al-Rashid Megat Ahmad

    2004-01-01

    Activated carbon have extensively been used as adsorbents in industry for the removal of pollutant species from gases for the purpose of purification and recovery of chemicals. The adsorption properties of the carbons depend very much on the porosity and type of pore presents which can be generated and controlled during synthesis and activation steps. This paper reports the effect of chemical activation by ZnCl 3 , KOH and nh 4 OH on the porosity of carbon produced from palm oil industry waste. Type of pores will further be validated by the SEM micrograph. The amount of gas adsorbed, the adsorption capacities can also be estimated based on the BET experiments data. The applicability of the produced carbon materials for the removal and exchange of hazardous incinerator gas is discussed. (Author)

  1. PanCoreGen - Profiling, detecting, annotating protein-coding genes in microbial genomes.

    Science.gov (United States)

    Paul, Sandip; Bhardwaj, Archana; Bag, Sumit K; Sokurenko, Evgeni V; Chattopadhyay, Sujay

    2015-12-01

    A large amount of genomic data, especially from multiple isolates of a single species, has opened new vistas for microbial genomics analysis. Analyzing the pan-genome (i.e. the sum of genetic repertoire) of microbial species is crucial in understanding the dynamics of molecular evolution, where virulence evolution is of major interest. Here we present PanCoreGen - a standalone application for pan- and core-genomic profiling of microbial protein-coding genes. PanCoreGen overcomes key limitations of the existing pan-genomic analysis tools, and develops an integrated annotation-structure for a species-specific pan-genomic profile. It provides important new features for annotating draft genomes/contigs and detecting unidentified genes in annotated genomes. It also generates user-defined group-specific datasets within the pan-genome. Interestingly, analyzing an example-set of Salmonella genomes, we detect potential footprints of adaptive convergence of horizontally transferred genes in two human-restricted pathogenic serovars - Typhi and Paratyphi A. Overall, PanCoreGen represents a state-of-the-art tool for microbial phylogenomics and pathogenomics study. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. [Effect of straw-returning on the storage and distribution of different active fractions of soil organic carbon].

    Science.gov (United States)

    Wang, Hul; Wang, Xu-dong; Tian, Xiao-hong

    2014-12-01

    The impacts of straw mulching and returning on the storage of soil dissolved organic carbon (DOC), particulate organic carbon (POC) and mineral associated organic carbon (MOC), and their proportions to the total organic carbon (TOC) were studied based on a field experiment. The results showed that compared to the treatment of wheat straw soil-returning (WR), the storage of TOC and MOC decreased by 4.1% and 9.7% respectively in 0-20 cm soil in the treatment with wheat straw mulching (WM), but the storage of DOC and POC increased by 207.7% and 11.9%, and TOC and POC increased significantly in 20-40 cm soil. Compared to the treatment with maize straw soil-returning (MR), the storage of TOC and MOC in the plough pan soil of the treatment with maize straw mulching (MM) increased by 13.6% and 14.6% , respectively. Compared to the WR-MR treatment, the storage of TOC and MOC in top soil (0-20 icm) significantly decreased by 8.5% and 10.3% respectively in WM-MM treatment. The storage of TOC, and POC in top soil was significantly higher in the treatments with maize straw soil-returning or mulching than that with wheat straw. Compared to the treatment without straw (CK), the storage of TOC in top soil increased by 5.2% to 18.0% in the treatments with straw returning or mulching in the six modes (WM, WR, MM, MR, WM-MM,WR-MR) (Porganic carbon fraction in soil, straw soil-returning had the potential to accumulate stable organic carbon fraction. Considering organic carbon sequestration in cropland in the region of Guanzhong plain, maize straw mulching or soil-returning was better than wheat straw, and wheat straw and maize straw soil-returning (WR-MR) were better than wheat and maize straw mulching (WM-MM).

  3. Observation-based modelling of permafrost carbon fluxes with accounting for deep carbon deposits and thermokarst activity

    Science.gov (United States)

    Schneider von Deimling, T.; Grosse, G.; Strauss, J.; Schirrmeister, L.; Morgenstern, A.; Schaphoff, S.; Meinshausen, M.; Boike, J.

    2015-06-01

    High-latitude soils store vast amounts of perennially frozen and therefore inert organic matter. With rising global temperatures and consequent permafrost degradation, a part of this carbon stock will become available for microbial decay and eventual release to the atmosphere. We have developed a simplified, two-dimensional multi-pool model to estimate the strength and timing of future carbon dioxide (CO2) and methane (CH4) fluxes from newly thawed permafrost carbon (i.e. carbon thawed when temperatures rise above pre-industrial levels). We have especially simulated carbon release from deep deposits in Yedoma regions by describing abrupt thaw under newly formed thermokarst lakes. The computational efficiency of our model allowed us to run large, multi-centennial ensembles under various scenarios of future warming to express uncertainty inherent to simulations of the permafrost carbon feedback. Under moderate warming of the representative concentration pathway (RCP) 2.6 scenario, cumulated CO2 fluxes from newly thawed permafrost carbon amount to 20 to 58 petagrams of carbon (Pg-C) (68% range) by the year 2100 and reach 40 to 98 Pg-C in 2300. The much larger permafrost degradation under strong warming (RCP8.5) results in cumulated CO2 release of 42 to 141 Pg-C and 157 to 313 Pg-C (68% ranges) in the years 2100 and 2300, respectively. Our estimates only consider fluxes from newly thawed permafrost, not from soils already part of the seasonally thawed active layer under pre-industrial climate. Our simulated CH4 fluxes contribute a few percent to total permafrost carbon release yet they can cause up to 40% of total permafrost-affected radiative forcing in the 21st century (upper 68% range). We infer largest CH4 emission rates of about 50 Tg-CH4 per year around the middle of the 21st century when simulated thermokarst lake extent is at its maximum and when abrupt thaw under thermokarst lakes is taken into account. CH4 release from newly thawed carbon in wetland

  4. Observation-based modelling of permafrost carbon fluxes with accounting for deep carbon deposits and thermokarst activity

    Directory of Open Access Journals (Sweden)

    T. Schneider von Deimling

    2015-06-01

    Full Text Available High-latitude soils store vast amounts of perennially frozen and therefore inert organic matter. With rising global temperatures and consequent permafrost degradation, a part of this carbon stock will become available for microbial decay and eventual release to the atmosphere. We have developed a simplified, two-dimensional multi-pool model to estimate the strength and timing of future carbon dioxide (CO2 and methane (CH4 fluxes from newly thawed permafrost carbon (i.e. carbon thawed when temperatures rise above pre-industrial levels. We have especially simulated carbon release from deep deposits in Yedoma regions by describing abrupt thaw under newly formed thermokarst lakes. The computational efficiency of our model allowed us to run large, multi-centennial ensembles under various scenarios of future warming to express uncertainty inherent to simulations of the permafrost carbon feedback. Under moderate warming of the representative concentration pathway (RCP 2.6 scenario, cumulated CO2 fluxes from newly thawed permafrost carbon amount to 20 to 58 petagrams of carbon (Pg-C (68% range by the year 2100 and reach 40 to 98 Pg-C in 2300. The much larger permafrost degradation under strong warming (RCP8.5 results in cumulated CO2 release of 42 to 141 Pg-C and 157 to 313 Pg-C (68% ranges in the years 2100 and 2300, respectively. Our estimates only consider fluxes from newly thawed permafrost, not from soils already part of the seasonally thawed active layer under pre-industrial climate. Our simulated CH4 fluxes contribute a few percent to total permafrost carbon release yet they can cause up to 40% of total permafrost-affected radiative forcing in the 21st century (upper 68% range. We infer largest CH4 emission rates of about 50 Tg-CH4 per year around the middle of the 21st century when simulated thermokarst lake extent is at its maximum and when abrupt thaw under thermokarst lakes is taken into account. CH4 release from newly thawed carbon in

  5. Damage symptoms of plants due to PAN exposure

    Energy Technology Data Exchange (ETDEWEB)

    Nouchi, I; Sawada, T; Ohashi, T; Odaira, T

    1974-11-01

    In order to identify the cause of plant damage which differed from that by ozone, a series of exposure experiments was carried out on Beta vulgaris, Japanese radish, French bean, luthern, tomato, and spinach in a controlled weather room by artificially synthesized PAN (peroxyacetyl nitrate). The damage appeared generally on younger leaves as a lustering and bronzing on the lower surface; there was a specific symptom in which the interveinary part of the lower surface depressed, leaving the veins in relief. At higher concentrations of PAN, damages appeared on the upper surface of leaves, however, bronzing and lustering were clearer during exposure to lower concentrations of PAN. The position of the leaves and the part of a leaf which was damaged were constant in the petunia, morning glory, and tobacco. There was a hyperbolic relationship between the concentration of PAN and the time period of appearance of the damage as was seen during sulfur dioxide and ozone exposures.

  6. Influence of chemical agents on the surface area and porosity of active carbon hollow fibers

    Directory of Open Access Journals (Sweden)

    LJILJANA M. KLJAJEVIĆ

    2011-09-01

    Full Text Available Active carbon hollow fibers were prepared from regenerated polysulfone hollow fibers by chemical activation using: disodium hydrogen phosphate 2-hydrate, disodium tetraborate 10-hydrate, hydrogen peroxide, and diammonium hydrogen phosphate. After chemical activation fibers were carbonized in an inert atmosphere. The specific surface area and porosity of obtained carbons were studied by nitrogen adsorption–desorption isotherms at 77 K, while the structures were examined with scanning electron microscopy and X-ray diffraction. The activation process increases these adsorption properties of fibers being more pronounced for active carbon fibers obtained with disodium tetraborate 10-hydrate and hydrogen peroxide as activator. The obtained active hollow carbons are microporous with different pore size distribution. Chemical activation with phosphates produces active carbon material with small surface area but with both mesopores and micropores. X-ray diffraction shows that besides turbostratic structure typical for carbon materials, there are some peaks which indicate some intermediate reaction products when sodium salts were used as activating agent. Based on data from the electrochemical measurements the activity and porosity of the active fibers depend strongly on the oxidizing agent applied.

  7. 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.

  8. Electrochemical performances and capacity fading behaviors of activated carbon/hard carbon lithium ion capacitor

    International Nuclear Information System (INIS)

    Sun, Xianzhong; Zhang, Xiong; Liu, Wenjie; Wang, Kai; Li, Chen; Li, Zhao; Ma, Yanwei

    2017-01-01

    Highlights: • Three-electrode pouch cell is used to investigate the capacity fading of AC/HC LIC. • the electrode potential swing is critical for the cycleability of a LIC cell. • Different capacity fading behaviors are discussed. • A large-capacity LIC pouch cell has been assembled with a specific energy of 18.1 Wh kg −1 based on the total weight. - Abstract: Lithium ion capacitor (LIC) is one of the most promising electrochemical energy storage devices, which offers rapid charging-discharging capability and long cycle life. We have fabricated LIC pouch cells using an electrochemically-driven lithium pre-doping method through a three-electrode pouch cell structure. The active materials of cathode and anode of LIC cell are activated carbon and pre-lithiated hard carbon, respectively. The electrochemical performances and the capacity fading behaviors of LICs in the voltage range of 2.0 − 4.0 V have been studied. The specific energy and specific power reach 73.6 Wh kg −1 and 11.9 kW kg −1 based on the weight of the active materials in both cathode and anode, respectively. Since the cycling performance is actually determined by hard carbon anode, the anode potential swings are emphasized. The capacity fading of LIC upon cycling is proposed to be caused by the increases of internal resistance and the consumption of lithium stored in anode. Finally, a large-capacity LIC pouch cell has been assembled with a maximum specific energy of 18.1 Wh kg −1 and a maximum specific power of 3.7 kW kg −1 based on the weight of the whole cell.

  9. In-air PIXE for analyzing heavy metals in water boiled in pans

    International Nuclear Information System (INIS)

    Tomita, M.; Haruyama, Y.; Saito, M.

    1993-01-01

    The release rates of heavy metals from pans were measured for boiling water as well as for an acidic solution prior to an investigation on the release or sorption of trace elements due to cooking of food by boiling. The boiled samples were condensed and analyzed by means of in-air PIXE. The release of heavy metals was measured for five kinds of pans. For all pans the release rates were considerably more increased by boiling of a 5% solution of acetic acid. Furthermore it was found that by using the alumina coated aluminum pan (alumina pan) the respective release rates of Fe, Cu and Zn were all less than 50 μg per 100 cm 2 of the pan surface dipped in the solution, and that monitoring of the contents of aluminum in the boiled solution enabled the estimation of the contribution of metal elements from the pan wall. (orig.)

  10. 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.

  11. Highly Efficient Procedure for the Synthesis of Fructone Fragrance Using a Novel Carbon based Acid

    Directory of Open Access Journals (Sweden)

    Xuezheng Liang

    2010-08-01

    Full Text Available The novel carbon based acid has been synthesized via one-step hydrothermal carbonization of furaldehyde and hydroxyethylsulfonic acid. A highly efficient procedure for the synthesis of fructone has been developed using the novel carbon based acid. The results showed that the catalyst possessed high activity for the reaction, giving a yield of over 95%. The advantages of high activity, stability, reusability and low cost for a simple synthesis procedure and wide applicability to various diols and β-keto esters make this novel carbon based acid one of the best choices for the reaction.

  12. The Pan-STARRS1 Survey Data Release

    Science.gov (United States)

    Chambers, Kenneth C.; Pan-STARRS Team

    2017-01-01

    The first Pan-STARRS1 Science Mission is complete and an initial Data Release 1, or DR1, including a database of measured attributes, stacked images, and metadata of the 3PI Survey, will be available from the STScI MAST archive. This release will contain all stationary objects with mean and stack photometry registered on the GAIA astrometric frame.The characteristics of the Pan-STARRS1 Surveys will be presented, including image quality, depth, cadence, and coverage. Measured attributes include PSF model magnitudes, aperture magnitudes, Kron Magnitudes, radial moments, Petrosian magnitudes, DeVaucoulers, Exponential, and Sersic magnitudes for extended objects. Images include total intensity, variance, and masks.An overview of both DR1 and the second data release DR2, to follow in the spring of 2017, will be presented. DR2 will add all time domain data and individual warped images. We will also report on the status of the Pan-STARRS2 Observatory and ongoing science with Pan-STARRS. The science from the PS1 surveys has included results in many t fields of astronomy from Near Earth Objects to cosmology.The Pan-STARRS1 Surveys have been made possible through contributions of the Institute for Astronomy of the University of Hawaii; the Pan-STARRS Project Office; the Max-Planck Society and its participating institutes: the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching; The Johns Hopkins University; Durham University; the University of Edinburgh; Queen's University Belfast; the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated; the National Central University of Taiwan; the Space Telescope Science Institute; the National Aeronautics and Space Administration under Grants No. NNX08AR22G, NNX12AR65G, NNX14AM74G issued through the Planetary Science Division of the NASA Science Mission Directorate; the National Science Foundation under Grant No. AST

  13. Real-Time FPGA-Based Object Tracker with Automatic Pan-Tilt Features for Smart Video Surveillance Systems

    Directory of Open Access Journals (Sweden)

    Sanjay Singh

    2017-05-01

    Full Text Available The design of smart video surveillance systems is an active research field among the computer vision community because of their ability to perform automatic scene analysis by selecting and tracking the objects of interest. In this paper, we present the design and implementation of an FPGA-based standalone working prototype system for real-time tracking of an object of interest in live video streams for such systems. In addition to real-time tracking of the object of interest, the implemented system is also capable of providing purposive automatic camera movement (pan-tilt in the direction determined by movement of the tracked object. The complete system, including camera interface, DDR2 external memory interface controller, designed object tracking VLSI architecture, camera movement controller and display interface, has been implemented on the Xilinx ML510 (Virtex-5 FX130T FPGA Board. Our proposed, designed and implemented system robustly tracks the target object present in the scene in real time for standard PAL (720 × 576 resolution color video and automatically controls camera movement in the direction determined by the movement of the tracked object.

  14. Adsorption/oxidation of sulfur-containing gases on nitrogen-doped activated carbon

    Directory of Open Access Journals (Sweden)

    Liu Qiang

    2016-01-01

    Full Text Available Coconut shell-based activated carbon (CAC was used for the removal of methyl mercaptan (MM. CAC was modified by urea impregnation and calcined at 450°C and 950°C. The desulfurization activity was determined in a fixed bed reactor under room temperature. The results showed that the methyl mercaptan adsorption/oxidation capacity of modified carbon caicined at 950°C is more than 3 times the capacity of original samples. On the other hand, the modified carbon caicined at 950°C also has a high capacity for the simultaneous adsorption/oxidation of methyl mercaptan and hydrogen sulfide.The introduce of basic nitrogen groups siginificantly increases the desulfurization since it can facilitate the electron transfer process between sulfur and oxygen. The structure and chemical properties are characterized using Boehm titration, N2 adsorption-desorption method, thermal analysis and elemental analysis. The results showed that the major oxidation products were dimethyl disulfide and methanesulfonic acid which adsorbed in the activated carbon.

  15. Adsorption characteristics of benzene on biosolid adsorbent and commercial activated carbons.

    Science.gov (United States)

    Chiang, Hung-Lung; Lin, Kuo-Hsiung; Chen, Chih-Yu; Choa, Ching-Guan; Hwu, Ching-Shyung; Lai, Nina

    2006-05-01

    This study selected biosolids from a petrochemical waste-water treatment plant as the raw material. The sludge was immersed in 0.5-5 M of zinc chloride (ZnCl2) solutions and pyrolyzed at different temperatures and times. Results indicated that the 1-M ZnCl2-immersed biosolids pyrolyzed at 500 degrees C for 30 min could be reused and were optimal biosolid adsorbents for benzene adsorption. Pore volume distribution analysis indicated that the mesopore contributed more than the macropore and micropore in the biosolid adsorbent. The benzene adsorption capacity of the biosolid adsorbent was 65 and 55% of the G206 (granular-activated carbon) and BPL (coal-based activated carbon; Calgon, Carbon Corp.) activated carbons, respectively. Data from the adsorption and desorption cycles indicated that the benzene adsorption capacity of the biosolid adsorbent was insignificantly reduced compared with the first-run capacity of the adsorbent; therefore, the biosolid adsorbent could be reused as a commercial adsorbent, although its production cost is high.

  16. Cooked Food Waste-An Efficient and Less Expensive Precursor for the Generation of Activated Carbon.

    Science.gov (United States)

    Krithiga, Thangavelu; Sabina, Xavier Janet; Rajesh, Baskaran; Ilbeygi, Hamid; Shetty, Adka Nityananda; Reddy, Ramanjaneya; Karthikeyan, Jayabalan

    2018-06-01

    Activated carbon was synthesized from cooked food waste, especially dehydrated rice kernels, by chemical activation method using NaOH and KOH as activating agents. It was then characterized by ultimate and proximate analysis, BET surface analysis, XRD, FTIR, Raman and SEM. The XRD patterns and Raman spectra confirmed the amorphous nature of the prepared activated carbons. Ultimate analysis showed an increase in the carbon content after activation of the raw carbon samples. Upon activation with NaOH and KOH, the surface area of the carbon sample was found to have increased from 0.3424 to 539.78 and 306.83 m2g-1 respectively. The SEM images revealed the formation of heterogeneous pores on the surface of the activated samples. The samples were then tested for their adsorption activity using acetic acid and methylene blue. Based on the regression coefficients, the adsorption kinetics of methylene blue dye were fitted with pseudo-second order model for both samples. Similarly, the Freundlich isotherm was found to be a better fit than Langmuir isotherm for both samples. The activity of thus prepared activated carbons was found to be comparable with the commercial carbon.

  17. Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

    NARCIS (Netherlands)

    Wille, M.M.W.; Riel, S.J. van; Saghir, Z.; Dirksen, A.; Pedersen, J.H.; Jacobs, C.; Thomsen, L.H.u.; Scholten, E.T.; Skovgaard, L.T.; Ginneken, B. van

    2015-01-01

    Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models.From the DLCST database, 1,152

  18. 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

  19. An easily accessible carbon material derived from carbonization of polyacrylonitrile ultrathin films: ambipolar transport properties and application in a CMOS-like inverter.

    Science.gov (United States)

    Jiao, Fei; Zhang, Fengjiao; Zang, Yaping; Zou, Ye; Di, Chong'an; Xu, Wei; Zhu, Daoben

    2014-03-04

    Ultrathin carbon films were prepared by carbonization of a solution processed polyacrylonitrile (PAN) film in a moderate temperature range (500-700 °C). The films displayed balanced hole (0.50 cm(2) V(-1) s(-1)) and electron mobilities (0.20 cm(2) V(-1) s(-1)) under ambient conditions. Spectral characterization revealed that the electrical transport is due to the formation of sp(2) hybridized carbon during the carbonization process. A CMOS-like inverter demonstrated the potential application of this material in the area of carbon electronics, considering its processability and low-cost.

  20. Sampling bee communities using pan traps: alternative methods increase sample size

    Science.gov (United States)

    Monitoring of the status of bee populations and inventories of bee faunas require systematic sampling. Efficiency and ease of implementation has encouraged the use of pan traps to sample bees. Efforts to find an optimal standardized sampling method for pan traps have focused on pan trap color. Th...

  1. Reductive dehalogenation of disinfection byproducts by an activated carbon-based electrode system.

    Science.gov (United States)

    Li, Yuanqing; Kemper, Jerome M; Datuin, Gwen; Akey, Ann; Mitch, William A; Luthy, Richard G

    2016-07-01

    Low molecular weight, uncharged, halogenated disinfection byproducts (DBPs) are poorly removed by the reverse osmosis and advanced oxidation process treatment units often applied for further treatment of municipal wastewater for potable reuse. Granular activated carbon (GAC) treatment effectively sorbed 22 halogenated DBPs. Conversion of the GAC to a cathode within an electrolysis cell resulted in significant degradation of the 22 halogenated DBPs by reductive electrolysis at -1 V vs. Standard Hydrogen Electrode (SHE). The lowest removal efficiency over 6 h electrolysis was for trichloromethane (chloroform; 47%) but removal efficiencies were >90% for 13 of the 22 DBPs. In all cases, DBP degradation was higher than in electrolysis-free controls, and degradation was verified by the production of halides as reduction products. Activated carbons and charcoal were more effective than graphite for electrolysis, with graphite featuring poor sorption for the DBPs. A subset of halogenated DBPs (e.g., haloacetonitriles, chloropicrin) were degraded upon sorption to the GAC, even without electrolysis. Using chloropicrin as a model, experiments indicated that this loss was attributable to the partial reduction of sorbed chloropicrin from reducing equivalents in the GAC. Reducing equivalents depleted by these reactions could be restored when the GAC was treated by reductive electrolysis. GAC treatment of an advanced treatment train effluent for potable reuse effectively reduced the concentrations of chloroform, bromodichloromethane and dichloroacetonitrile measured in the column influent to below the method detection limits. Treatment of the GAC by reductive electrolysis at -1 V vs. SHE over 12 h resulted in significant degradation of the chloroform (63%), bromodichloromethane (96%) and dichloroacetonitrile (99%) accumulated on the GAC. The results suggest that DBPs in advanced treatment train effluents could be captured and degraded continuously by reductive electrolysis

  2. 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

  3. 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.

  4. Efficiency of moso bamboo charcoal and activated carbon for adsorbing radioactive iodine

    Energy Technology Data Exchange (ETDEWEB)

    Chien, Chuan-Chi; Huang, Ying-Pin; Wang, Wie-Chieh [ITRI South, Industrial Technology Research Institute, Tainan (China); Chao, Jun-Hsing; Wei, Yuan-Yao [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu (China)

    2011-02-15

    Preventing radioactive pollution is a troublesome problem but an urgent concern worldwide because radioactive substances cause serious health-related hazards to human being. The adsorption method has been used for many years to concentrate and remove radioactive pollutants; selecting an adequate adsorbent is the key to the success of an adsorption-based pollution abatement system. In Taiwan, all nuclear power plants use activated carbon as the adsorbent to treat radiation-contaminated air emission. The activated carbon is entirely imported; its price and manufacturing technology are entirely controlled by international companies. Taiwan is rich in bamboo, which is one of the raw materials for high-quality activated carbon. Thus, a less costly activated carbon with the same or even better adsorptive capability as the imported adsorbent can be made from bamboo. The objective of this research is to confirm the adsorptive characteristics and efficiency of the activated carbon made of Taiwan native bamboo for removing {sup 131}I gas from air in the laboratory. The study was conducted using new activated carbon module assembled for treating {sup 131}I-contaminated air. The laboratory results reveal that the {sup 131}I removal efficiency for a single-pass module is as high as 70%, and the overall efficiency is 100% for four single-pass modules operated in series. The bamboo charcoal and bamboo activated carbon have suitable functional groups for adsorbing {sup 131}I and they have greater adsorption capacities than commercial activated carbons. Main mechanism is for trapping of radioiodine on impregnated charcoal, as a result of surface oxidation. When volatile radioiodine is trapped by potassium iodide-impregnated bamboo charcoal, the iodo-compound is first adsorbed on the charcoal surface, and then migrates to iodide ion sites where isotope exchange occurs. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. The CO2 Abundance in Comets C2012 K1 (PanSTARRS), C2012 K5 (LINEAR), and 290P Jager as Measured with Spitzer

    Science.gov (United States)

    McKay, Adam J.; Kelley, Michael S.P.; Cochran, Anita L.; Bodewits, Dennis; DiSanti, Michael A.; Dello Russo, Neil; Lisse, Carey M.

    2015-01-01

    Carbon dioxide is one of the most abundant ices present in comets and is therefore important for understanding cometary composition and activity. We present analysis of observations of CO2 and [O I] emission in three comets to measure the CO2 abundance and evaluate the possibility of employing observations of [O I] emission in comets as a proxy for CO2. We obtained NIR imaging sensitive to CO2 of comets C/2012 K1 (PanSTARRS), C/2012 K5 (LINEAR), and 290P/Jager with the IRAC instrument on Spitzer. We acquired observations of [O I] emission in these comets with the ARCES echelle spectrometer mounted on the 3.5-m telescope at Apache Point Observatory and observations of OH with the Swift observatory (PanSTARRS) and with Keck HIRES (Jager). The CO2/H2O ratios derived from the Spitzer images are 12.6 +/- 1.3% (PanSTARRS), 28.9 +/- 3.6% (LINEAR), and 31.3 +/- 4.2% (Jager). These abundances are derived under the assumption that contamination from CO emission is negligible. The CO2 abundance for PanSTARRS is close to the average abundance measured in comets at similar heliocentric distance to date, while the abundances measured for LINEAR and Jager are significantly larger than the average abundance. From the coma morphology observed in PanSTARRS and the assumed gas expansion velocity, we derive a rotation period for the nucleus of about 9.2 h. Comparison of H2O production rates derived from ARCES and Swift data, as well as other observations, suggest the possibility of sublimation from icy grains in the inner coma. We evaluate the possibility that the [O I] emission can be employed as a proxy for CO2 by comparing CO2/H2O ratios inferred from the [O I] lines to those measured directly by Spitzer. We find that for PanSTARRS we can reproduce the observed CO2 abundance to an accuracy of approximately 20%. For LINEAR and Jager, we were only able to obtain upper limits on the CO2 abundance inferred from the [O I] lines. These upper limits are consistent with the CO2 abundances

  6. Evolution of the ATLAS PanDA Workload Management System for Exascale Computational Science

    CERN Document Server

    Maeno, T; The ATLAS collaboration; Klimentov, A; Nilsson, P; Oleynik, D; Panitkin, S; Petrosyan, A; Schovancova, J; Vaniachine, A; Wenaus, T; Yu, D

    2013-01-01

    An important foundation underlying the impressive success of data processing and analysis in the ATLAS experiment [1] at the LHC [2] is the Production and Distributed Analysis (PanDA) workload management system [3]. PanDA was designed specifically for ATLAS and proved to be highly successful in meeting all the distributed computing needs of the experiment. However, the core design of PanDA is not experiment specific. The PanDA workload management system is capable of meeting the needs of other data intensive scientific applications. Alpha-Magnetic Spectrometer [4], an astro-particle experiment on the International Space Station, and the Compact Muon Solenoid [5], an LHC experiment, have successfully evaluated PanDA and are pursuing its adoption. In this paper, a description of the new program of work to develop a generic version of PanDA will be given, as well as the progress in extending PanDA's capabilities to support supercomputers and clouds and to leverage intelligent networking. PanDA has demonstrated a...

  7. Evolution of the ATLAS PanDA Workload Management System for Exascale Computational Science

    CERN Document Server

    Maeno, T; The ATLAS collaboration; Klimentov, A; Nilsson, P; Oleynik, D; Panitkin, S; Petrosyan, A; Schovancova, J; Vaniachine, A; Wenaus, T; Yu, D

    2014-01-01

    An important foundation underlying the impressive success of data processing and analysis in the ATLAS experiment [1] at the LHC [2] is the Production and Distributed Analysis (PanDA) workload management system [3]. PanDA was designed specifically for ATLAS and proved to be highly successful in meeting all the distributed computing needs of the experiment. However, the core design of PanDA is not experiment specific. The PanDA workload management system is capable of meeting the needs of other data intensive scientific applications. Alpha-Magnetic Spectrometer [4], an astro-particle experiment on the International Space Station, and the Compact Muon Solenoid [5], an LHC experiment, have successfully evaluated PanDA and are pursuing its adoption. In this paper, a description of the new program of work to develop a generic version of PanDA will be given, as well as the progress in extending PanDA's capabilities to support supercomputers and clouds and to leverage intelligent networking. PanDA has demonstrated a...

  8. PanDA Beyond ATLAS: Workload Management for Data Intensive Science

    CERN Document Server

    Schovancova, J; The ATLAS collaboration; Klimentov, A; Maeno, T; Nilsson, P; Oleynik, D; Panitkin, S; Petrosyan, A; Vaniachine, A; Wenaus, T; Yu, D

    2013-01-01

    The PanDA Production ANd Distributed Analysis system has been developed by ATLAS to meet the experiment's requirements for a data-driven workload management system for production and distributed analysis processing capable of operating at LHC data processing scale. After 7 years of impressively successful PanDA operation in ATLAS there are also other experiments which can benefit from PanDA in the Big Data challenge, with several at various stages of evaluation and adoption. The new project "Next Generation Workload Management and Analysis System for Big Data" is extending PanDA to meet the needs of other data intensive scientific applications in HEP, astro-particle and astrophysics communities, bio-informatics and other fields as a general solution to large scale workload management. PanDA can utilize dedicated or opportunistic computing resources such as grids, clouds, and High Performance Computing facilities, and is being extended to leverage next generation intelligent networks in automated workflow mana...

  9. Grafting of activated carbon cloths for selective adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Gineys, M.; Benoit, R.; Cohaut, N.; Béguin, F.; Delpeux-Ouldriane, S., E-mail: delpeux@cnrs-orleans.fr

    2016-05-01

    Graphical abstract: - Highlights: • A controlled grafting of carboxylic functions on activated carbon fibers. • The carbon material nanotextural properties preservation after grafting. • An identification of the grafting mechanism through ToF SIMS analysis. • A chemical mapping of the grafted surface using ToF SIMS technique and imaging. - Abstract: Chemical functionalization of an activated carbon cloth with 3-aminophthalic acid and 4-aminobenzoic acid groups by the in situ formation of the corresponding diazonium salt in aqueous acidic solution is reported. The nature and amount of selected functions on an activated carbon surface, in particular the grafted density, were determined by potentiometric titration, elemental analysis and X-ray photoelectron spectroscopy (XPS). The nanotextural properties of the modified carbon were explored by gas adsorption. Functionalized activated carbon cloth was obtained at a discrete grafting level while preserving interesting textural properties and a large porous volume. Finally, the grafting homogeneity of the carbon surface and the nature of the chemical bonding were investigated using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) technique.

  10. Activated carbon-supported CuO nanoparticles: a hybrid material for carbon dioxide adsorption

    Science.gov (United States)

    Boruban, Cansu; Esenturk, Emren Nalbant

    2018-03-01

    Activated carbon-supported copper(II) oxide (CuO) nanoparticles were synthesized by simple impregnation method to improve carbon dioxide (CO2) adsorption capacity of the support. The structural and chemical properties of the hybrid material were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (https://www.google.com.tr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCsQFjAC&url=http%3A%2F%2Fwww.intertek.com%2Fanalytical-laboratories%2Fxrd%2F&ei=-5WZVYSCHISz7Aatqq-IAw&usg=AFQjCNFBlk-9wqy49foh8tskmbD-GGbG9g&sig2=eKrhYjO75rl_Id2sLGpq4w&bvm=bv.96952980,d.bGg) (XRD), X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), and Brunauer-Emmett-Teller (BET) analyses. The analyses showed that CuO nanoparticles are well-distributed on the activated carbon surface. The CO2 adsorption behavior of the activated carbon-supported CuO nanoparticles was observed by thermogravimetric analysis (TGA), temperature programmed desorption (TPD), Fourier transform infrared (FTIR), and BET analyses. The results showed that CuO nanoparticle loading on activated carbon led to about 70% increase in CO2 adsorption capacity of activated carbon under standard conditions (1 atm and 298 K). The main contributor to the observed increase is an improvement in chemical adsorption of CO2 due to the presence of CuO nanoparticles on activated carbon.

  11. Microbial biomass carbon and enzyme activities of urban soils in Beijing.

    Science.gov (United States)

    Wang, Meie; Markert, Bernd; Shen, Wenming; Chen, Weiping; Peng, Chi; Ouyang, Zhiyun

    2011-07-01

    To promote rational and sustainable use of soil resources and to maintain the urban soil quality, it is essential to assess urban ecosystem health. In this study, the microbiological properties of urban soils in Beijing and their spatial distribution patterns across the city were evaluated based on measurements of microbial biomass carbon and urease and invertase activities of the soils for the purpose of assessing the urban ecosystem health of Beijing. Grid sampling design, normal Kriging technique, and the multiple comparisons among different land use types were used in soil sampling and data treatment. The inherent chemical characteristics of urban soils in Beijing, e.g., soil pH, electronic conductivity, heavy metal contents, total N, P and K contents, and soil organic matter contents were detected. The size and diversity of microbial community and the extent of microbial activity in Beijing urban soils were measured as the microbial biomass carbon content and the ratio of microbial biomass carbon content to total soil organic carbon. The microbial community health measured in terms of microbial biomass carbon, urease, and invertase activities varied with the organic substrate and nutrient contents of the soils and were not adversely affected by the presence of heavy metals at p urban soils influenced the nature and activities of the microbial communities.

  12. Pollutants removal onto novel activated carbons made from lignocellulosic precursors

    OpenAIRE

    Valente Nabais, Joao; Laginhas, Carlos; Carrott, Manuela; Carrott, Peter; Gomes, Jose; Suhas, Suhas; Ramires, Ana; Roman, Silvia

    2009-01-01

    The adsorption of phenol and mercury from dilute aqueous solutions onto new activated carbons was studied. These included activated carbons produced from novel precursors, namely rapeseed, vine shoots and kenaf, and samples oxidised with nitric acid in liquid phase. The results have shown the significant potential of rapeseed, vine shoots and kenaf for the activated carbon production. The activated carbons produced by carbon dioxide activation were mainly microporous with BET apparent surface...

  13. p-Chlorophenol adsorption on activated carbons with basic surface properties

    Science.gov (United States)

    Lorenc-Grabowska, Ewa; Gryglewicz, Grażyna; Machnikowski, Jacek

    2010-05-01

    The adsorption of p-chlorophenol (PCP) from aqueous solution on activated carbons (ACs) with basic surface properties has been studied. The ACs were prepared by two methods. The first method was based on the modification of a commercial CWZ AC by high temperature treatment in an atmosphere of ammonia, nitrogen and hydrogen. The second approach comprised the carbonization followed by activation of N-enriched polymers and coal tar pitch using CO 2 and steam as activation agent. The resultant ACs were characterized in terms of porous structure, elemental composition and surface chemistry (pH PZC, acid/base titration, XPS). The adsorption of PCP was carried out from an aqueous solution in static conditions. Equilibrium adsorption isotherm was of L2 type for polymer-based ACs, whereas L3-type isotherm was observed for CWZ ACs series. The Langmuir monolayer adsorption capacity was related to the porous structure and the amount of basic sites. A good correlation was found between the adsorption capacity and the volume of micropores with a width water molecule adsorption on the PCP uptake is discussed.

  14. Microbial comparative pan-genomics using binomial mixture models

    Directory of Open Access Journals (Sweden)

    Ussery David W

    2009-08-01

    Full Text Available Abstract Background The size of the core- and pan-genome of bacterial species is a topic of increasing interest due to the growing number of sequenced prokaryote genomes, many from the same species. Attempts to estimate these quantities have been made, using regression methods or mixture models. We extend the latter approach by using statistical ideas developed for capture-recapture problems in ecology and epidemiology. Results We estimate core- and pan-genome sizes for 16 different bacterial species. The results reveal a complex dependency structure for most species, manifested as heterogeneous detection probabilities. Estimated pan-genome sizes range from small (around 2600 gene families in Buchnera aphidicola to large (around 43000 gene families in Escherichia coli. Results for Echerichia coli show that as more data become available, a larger diversity is estimated, indicating an extensive pool of rarely occurring genes in the population. Conclusion Analyzing pan-genomics data with binomial mixture models is a way to handle dependencies between genomes, which we find is always present. A bottleneck in the estimation procedure is the annotation of rarely occurring genes.

  15. Selective Oxidation of Glycerol to Glyceric Acid in Base-Free Aqueous Solution at Room Temperature Catalyzed by Platinum Supported on Carbon Activated with Potassium Hydroxide

    KAUST Repository

    Tan, Hua

    2016-04-18

    Pt supported on KOH-activated mesoporous carbon (K-AMC) was used to catalyze glycerol oxidation under base-free conditions at room temperature. To study the relationship between the carbon surface chemistry and the catalytic performance of the K-AMC-based Pt catalysts, different levels of surface oxygen functional groups (SOFGs) on the AMC supports were induced by thermal treatment at different temperatures under inert or H2 gas. A strong effect of the surface chemistry was observed on AMC-supported Pt catalysts for glycerol oxidation. The presence of carboxylic acid groups impedes the adsorption of glycerol, which leads to the reduction of catalytic activity, whereas the presence of high-desorption-temperature SOFGs, such as phenol, ether, and carbonyl/quinone groups, provide hydrophilicity to the carbon surface that improves the adsorption of glycerol molecules on Pt metal surface, which is beneficial for the catalytic activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Radiological Protection Measurements Implemented during the 16. Pan American and 4. ParaPan American Games: Guadalajara, Mexico, 2011

    International Nuclear Information System (INIS)

    2014-02-01

    Terrorism remains a threat to international stability and security. Often national and international high level public events are the subject of much public interest and receive extensive coverage in the media. In this sense, it is well known that there is a real threat of a terrorist attack in important public events, such as major economic summits, high level political meetings or sporting events. In 1955 and 1975, the 2nd and 7th Pan American Games were organized by the City of Mexico. In 2011, the Pan American Games was the third event of its kind held in Guadalajara, Jalisco. At the national level, the implementation of nuclear security measures in the Pan American Games laid the foundations for a sustainable national nuclear security framework that will continue long after the event. The political decision, the existing legal basis and structure, agency coordination facilitated the incorporation of nuclear security measures. It was also a challenge to integrate all the relevant organizations, provide focus to the threat of terrorism linked to weapons of mass destruction for security games, plan resources and execute the project on time, among other details. For this reason, information and lessons learned that are reported in this document, received in Mexico during the 16th edition of the Pan American Games will be useful for the implementation of nuclear security measures in States with similar situations

  17. Adsorption characteristics of trace levels of bromate in drinking water by modified bamboo-based activated carbons.

    Science.gov (United States)

    Chen, Ho-Wen; Chuang, Yen Hsun; Hsu, Cheng-Feng; Huang, Winn-Jung

    2017-09-19

    This study was undertaken to investigate the adsorption kinetics and isotherms of bromate (BrO 3 - ) on bamboo charcoals that are activated with nitrogen and water vapor. Bamboo-based activated carbon (AC) was dipped in acid and oxidized in a mixture of potassium permanganate and sulfuric acid. Oxidation treatment considerably improved the physicochemical properties of AC, including purity, pore structure and surface nature, significantly enhancing BrO 3 - adsorption capacity. AC with many oxygenated groups and a high mesopore volume exhibited a particularly favorable tendency for BrO 3 - adsorption. Its adsorption of BrO 3 - is best fitted using Langmuir isotherm, and forms a monolayer. A kinetic investigation revealed that the adsorption of BrO 3 - by the ACs involved chemical sorption and was controlled by intra-particle diffusion. The competitive effects of natural organic matter (NOM) on AC were evaluated, and found to reduce the capacity of carbon to adsorb BrO 3 - . Residual dissolved ozone reacted with AC, reducing its capacity to absorb BrO 3 - . Proper dosing and staging of the ozonation processes can balance the ozone treatment efficiency, BrO 3 - formation, and the subsequent removal of BrO 3 - .

  18. A General Methodology for Evaluation of Carbon Sequestration Activities and Carbon Credits

    Energy Technology Data Exchange (ETDEWEB)

    Klasson, KT

    2002-12-23

    A general methodology was developed for evaluation of carbon sequestration technologies. In this document, we provide a method that is quantitative, but is structured to give qualitative comparisons despite changes in detailed method parameters, i.e., it does not matter what ''grade'' a sequestration technology gets but a ''better'' technology should receive a better grade. To meet these objectives, we developed and elaborate on the following concepts: (1) All resources used in a sequestration activity should be reviewed by estimating the amount of greenhouse gas emissions for which they historically are responsible. We have done this by introducing a quantifier we term Full-Cycle Carbon Emissions, which is tied to the resource. (2) The future fate of sequestered carbon should be included in technology evaluations. We have addressed this by introducing a variable called Time-adjusted Value of Carbon Sequestration to weigh potential future releases of carbon, escaping the sequestered form. (3) The Figure of Merit of a sequestration technology should address the entire life-cycle of an activity. The figures of merit we have developed relate the investment made (carbon release during the construction phase) to the life-time sequestration capacity of the activity. To account for carbon flows that occur during different times of an activity we incorporate the Time Value of Carbon Flows. The methodology we have developed can be expanded to include financial, social, and long-term environmental aspects of a sequestration technology implementation. It does not rely on global atmospheric modeling efforts but is consistent with these efforts and could be combined with them.

  19. Modeling boron separation from water by activated carbon, impregnated and unimpregnated

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, M.; Grbavcic, Z. [Belgrade Univ., Belgrade (BA). Faculty of Technology and Metallurgy; Marinovic, V. [Belgrade Univ., Belgrade (BA). Ist. of Technical Science of the Serbian Academy of Science and Arts

    2000-10-01

    The sorption of boron from boric acid water solution by impregnated activated carbon has been studied. Barium, calcium, mannitol, tartaric acid and citric acid were used as chemical active materials. All processes were performed in a chromatographic continuous system at 22{sup 0} C. Experimental results show that activated carbon impregnated with mannitol is effective in removing boron from water. The separation of boron from the wastewater from a factory for producing enameled dishes by activated carbon impregnated with mannitol was also performed. Two models have been applied to describe published and new data on boron sorption by impregnated activated carbon. Both of them are based on the analysis of boron concentration response to the step input function. This led to a mathematical model that quite successfully described impregnation effects on adsorption capacities. [Italian] E' stato studiato l'assorbimento del boro, mediante carbone attivo impregnato, da soluzioni acquose di acido borico. Quali materiali chimici attivi sono stati utilizzati: bario, calcio, mannitolo, acido tartarico ed acido citrico. Tutti i processi sono stati condotti in un sistema cromatografico continuo a 22{sup 0}C. I risultati sperimentali mostrano che il carbone attivo impregnato con mannitolo e' efficace nella rimozione del boro dall'acqua. E' anche stata effettuata la separazione del boro da acque di scarico di un'industria per la produzione di piatti smaltati mediante carbone attivo impregnato con mannitolo. Sono stati applicati due modelli per descrivere i risultati, pubblicati e nuovi, dell'assorbimento del boro mediante carbone attivo impregnato. Entrambi sono basati sull'analisi della risposta alla concentrazione di boro successivamente incrementata a stadi. Cio' porta ad un modello matematico che descrive abbastanza soddisfacentemente gli effetti dell'impregnazione sulla capacita' di assorbimento.

  20. Pan-London tuberculosis services: a service evaluation

    Directory of Open Access Journals (Sweden)

    Belling Ruth

    2012-07-01

    Full Text Available Abstract Background London has the largest proportion of tuberculosis (TB cases of any western European capital, with almost half of new cases drug-resistant. Prevalence varies considerably between and within boroughs with research suggesting inadequate control of TB transmission in London. Economic pressures may exacerbate the already considerable challenges for service organisation and delivery within this context. This paper presents selected findings from an evaluation of London’s TB services’ organisation, delivery, professional workforce and skill mix, intended to support development of a strategic framework for a pan-London TB service. These may also interest health service professionals and managers in TB services in the UK, other European cities and countries and in services currently delivered by multiple providers operating independently. Methods Objectives were: 1 To establish how London’s TB services are structured and delivered in relation to leadership, management, organisation and delivery, coordination, staffing and support; 2 To identify tools/models for calculating skill mix as a basis for identifying skill mix requirements in delivering TB services across London; 3 To inform a strategic framework for the delivery of a pan-London TB service, which may be applicable to other European cities. The multi-method service audit evaluation comprised documentary analysis, semi-structured interviews with TB service users (n = 10, lead TB health professionals and managers (n = 13 representing London’s five sectors and focus groups with TB nurses (n = 8 and non-London network professionals (n = 2. Results Findings showed TB services to be mainly hospital-based, with fewer community-based services. Documentary analysis and professionals’ interviews suggested difficulties with early access to services, low suspicion index amongst some GPs and restricted referral routes. Interviews indicated lack of managed