WorldWideScience

Sample records for replica carbon production

  1. Standard practice for production and evaluation of field metallographic replicas

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice covers recognized methods for the preparation and evaluation of cellulose acetate or plastic film replicas which have been obtained from metallographically prepared surfaces. It is designed for the evaluation of replicas to ensure that all significant features of a metallographically prepared surface have been duplicated and preserved on the replica with sufficient detail to permit both LM and SEM examination with optimum resolution and sensitivity. 1.2 This practice may be used as a controlling document in commercial situations. 1.3 The values stated in SI units are to be regarded as the standard. Inch-pound units given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  2. Are Bosonic Replicas Faulty?

    CERN Document Server

    Osipov, Vladimir Al

    2007-01-01

    Motivated by the ongoing discussion about a seeming asymmetry in the performance of fermionic and bosonic replicas, we present an exact, nonperturbative approach to zero-dimensional replica field theories belonging to the broadly interpreted "beta=2" Dyson symmetry class. We then utilise the formalism developed to demonstrate that the bosonic replicas do correctly reproduce the microscopic spectral density in the QCD inspired chiral Gaussian unitary ensemble. This disproves the myth that the bosonic replica field theories are intrinsically faulty.

  3. Hierarchical control of porous silica by pH adjustment: Alkyl polyamines as surfactants for bimodal silica synthesis and its carbon replica

    Science.gov (United States)

    Abellán, G.; Carrillo, A. I.; Linares, N.; Serrano, E.; García-Martínez, J.

    2009-08-01

    Bimodal macro-mesoporous silica networks have been prepared in a simple one-pot synthesis using an inexpensive tetramine surfactant and tetraethoxysilane as a silica precursor. These novel materials show high pore volumes and templated mesopores (average pore size 3.0 nm) embedded in 20 nm thick walls forming interparticle large meso/macropores. The judicious control of the pH during the silica formation allows for the precise control of the interparticle condensation, likely due to the change in the interaction between the tetramine surfactant and the silica precursors. Finally, a highly porous carbon replica with bimodal porosity was prepared by using the bimodal silica as a hard sacrificial template. The microstructure of the silica template was accurately transferred to the carbon material obtaining high surface areas (up to 1300 m 2 g -1) and total pore volumes ≥2 cm 3 g -1.

  4. Production of carbon nanotubes

    Science.gov (United States)

    Journet, C.; Bernier, P.

    Carbon nanostructures such as single-walled and multi-walled nanotubes (SWNTs and MWNTs) or graphitic polyhedral nanoparticles can be produced using various methods. Most of them are based on the sublimation of carbon under an inert atmosphere, such as the electric arc discharge process, the laser ablation method, or the solar technique. But chemical methods can also be used to synthesize these kinds of carbon materials: the catalytic decomposition of hydrocarbons, the production by electrolysis, the heat treatment of a polymer, the low temperature solid pyrolysis, or the in situ catalysis.

  5. Nanocasting of carbon films with interdigitated bimodal three-dimensionally ordered mesopores by template-replica coassembly.

    Science.gov (United States)

    Tian, Zheng; Snyder, Mark A

    2014-10-21

    Carbon films with interdigitated bimodal three-dimensionally ordered mesoporosity (ib3DOm) are realized by a scalable nanoreplication process that removes the common need plaguing hard-templating strategies for multistep prefabrication of porous sacrificial templates. Specifically, evaporation-induced convective codeposition of size-tunable (ca. 20-50 nm) silica nanoparticles with a surrogate molecular carbon precursor (glucose), followed by carbonization and template etching, leads to remarkably ordered, crack-free mesoporous carbon films of tunable thickness (ca. 100-1000 nm) and pore size. Association of the molecular carbon precursor with the assembling pore forming particles is found to transition the system among three distinct film morphologies (collapsed, ib3DOm C, disordered), thereby establishing a pseudophase behavior controlled by silica solids content and incipient glucose concentration. Namely, a parametric window wherein ib3DOm C films can be realized is identified, with a diffuse lower phase boundary associated with collapsing carbon films, and a more distinct order-to-disorder transition encountered at higher glucose concentrations. Mechanistic insight suggests that glucose association with the lysine-silica nanoparticle surface modulates the lattice spacing, d, of the periodically ordered mesopores in the coassembled films, with the onset of the order-to-disorder transition occurring at a critical normalized lattice spacing, dc/D ∼ 1.16. This appears to apply across the phase space associated with D = 50 nm silica particles and to translate among other phase spaces associated with smaller particles (e.g., 30 nm). We briefly demonstrate the robustness of the codeposition process for realizing ib3DOm C films on rough FTO glass substrates and show that, in this form, these materials hold potential as low-cost alternatives to costly platinum electrodes for dye-sensitized solar cells.

  6. Crystal Ball Replica

    Science.gov (United States)

    Ajamian, John

    2016-09-01

    The A2 collaboration of the Institute for Nuclear Physics of Johannes Gutenberg University performs research on (multiple) meson photoproduction and nucleon structure and dynamics using a high energy polarized photon beam at specific targets. Particles scattered from the target are detected in the Crystal Ball, or CB. The CB is composed of 672 NaI crystals that surround the target and can analyze particle type and energy of ejected particles. Our project was to create a replica of the CB that could display what was happening in real time on a 3 Dimensional scale replica. Our replica was constructed to help explain the physics to the general public, be used as a tool when calibrating each of the 672 NaI crystals, and to better analyze the electron showering of particles coming from the target. This poster will focus on the hardware steps necessary to construct the replica and wire the 672 programmable LEDS in such a way that they can be mapped to correspond to the Crystal Ball elements. George Washington NSF Grant.

  7. Hyper-V Replica essentials

    CERN Document Server

    Krstevski, Vangel

    2013-01-01

    a in various deployment scenarios.Hyper-V Replica Essentials is for Windows Server administrators who want to improve their system availability and speed up disaster recovery. You will need experience in Hyper-V deployment because Hyper-V Replica is built in the Hyper-V platform.

  8. Reducing carbon dioxide to products

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

    2014-09-30

    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  9. T2K Replica Target Hadron Production Measurements in NA61/SHINE and T2K Neutrino Flux Predictions

    CERN Document Server

    AUTHOR|(SzGeCERN)710687

    Accelerator based neutrino experiments generate their neutrino beams by impinging high energy protons on thick targets. The neutrino beam predictions are thus based on modeling the interactions of the beam protons inside the targets. Different hadronic models can be used with different accuracies depending on the energy range of the incident protons and on the target material. Nevertheless, none of the models can be seen as perfectly describing all different interactions. In order to reach high precision neutrino flux predictions, it is thus mandatory to be able to test and constrain the models with hadron production measurements. The T2K experiment in Japan uses the ancillary NA61/SHINE facility at CERN to constrain the production of hadrons resulting from the interactions of proton beam particles impinging on a 90cm long graphite target. Data taken by NA61/SHINE with a 30 GeV proton beam on a thin (4% interaction length) graphite target have been recorded in 2007 and 2009. They have been analysed and extens...

  10. Replica trick for rare samples

    Science.gov (United States)

    Rizzo, Tommaso

    2014-05-01

    In the context of disordered systems with quenched Hamiltonians I address the problem of characterizing rare samples where the thermal average of a specific observable has a value different from the typical one. These rare samples can be selected through a variation of the replica trick which amounts to replicating the system and dividing the replicas intwo two groups containing, respectively, M and -M replicas. Replicas in the first (second) group experience a positive (negative) small field O (1/M) conjugate to the observable considered and the M →∞ limit is to be taken in the end. Applications to the random-field Ising model and to the Sherrington-Kirkpatrick model are discussed.

  11. Minimizing activated carbons production cost

    Energy Technology Data Exchange (ETDEWEB)

    Stavropoulos, G.G.; Zabaniotou, A.A. [Department of Chemical Engineering, Aristotle University of Thessaloniki, Univ. P. O. Box 1520, 54006, Thessaloniki (Greece)

    2009-07-15

    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)

  12. Computer simulation study of in-zeolites templated carbon replicas: structural and adsorption properties for hydrogen storage application; simulation numerique de repliques de zeolithes en carbone: structures et proprietes d'adsorption en vue d'une application au stockage d'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Roussel, T

    2007-05-15

    Hydrogen storage is the key issue to envisage this gas for instance as an energy vector in the field of transportation. Porous carbons are materials that are considered as possible candidates. We have studied well-controlled microporous carbon nano-structures, carbonaceous replicas of meso-porous ordered silica materials and zeolites. We realized numerically (using Grand Canonical Monte Carlo Simulations, GCMC) the atomic nano-structures of the carbon replication of four zeolites: AlPO{sub 4}-5, silicalite-1, and Faujasite (FAU and EMT). The faujasite replicas allow nano-casting of a new form of carbon crystalline solid made of tetrahedrally or hexagonally interconnected single wall nano-tubes. The pore size networks are nano-metric giving these materials optimized hydrogen molecular storage capacities (for pure carbon phases). However, we demonstrate that these new carbon forms are not interesting for room temperature efficient storage compared to the void space of a classical gas cylinder. We showed that doping with an alkaline element, such as lithium, one could store the same quantities at 350 bar compared to a classical tank at 700 bar. This result is a possible route to achieve interesting performances for on-board docking systems for instance. (author)

  13. Replica trick and string winding

    Science.gov (United States)

    Prudenziati, Andrea; Trancanelli, Diego

    2017-07-01

    We apply the replica trick to compute the entropy of a cylinder amplitude in string theory. We focus on the contribution from nonperturbative winding modes and impose tadpole cancellation to understand the correct prescription for integrating over moduli. Choosing the entangling surface to cut longitudinally over the whole length of the cylinder, we obtain an answer that is interpreted as the entropy of a density matrix. We recast this result in target space language, in both the open and closed string picture.

  14. Replica trick and string winding

    CERN Document Server

    Prudenziati, Andrea

    2016-01-01

    We apply the replica trick to compute the entropy of a cylinder amplitude in string theory. We focus on the contribution from non-perturbative winding modes and impose tadpole cancellation to understand the correct prescription for integrating over moduli. Choosing the entangling surface to cut longitudinally over the whole length of the cylinder, we obtain an answer that is interpreted as the entropy of a density matrix. We recast this result in target space language, both in the open and closed string picture.

  15. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

    Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.

    2008-01-01

    This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o......C) has often been used. The article shows that the carbon dioxide production per hpu increases with increasing respiration quotient. As the respiration quotient increases with body mass for growing animals, the carbon dioxide production per heat production unit also increases with increased body mass...

  16. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

    Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.

    2008-01-01

    This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o......C) has often been used. The article shows that the carbon dioxide production per hpu increases with increasing respiration quotient. As the respiration quotient increases with body mass for growing animals, the carbon dioxide production per heat production unit also increases with increased body mass...

  17. A carbon sink pathway increases carbon productivity in cyanobacteria.

    Science.gov (United States)

    Oliver, John W K; Atsumi, Shota

    2015-05-01

    The burning of fossil reserves, and subsequent release of carbon into the atmosphere is depleting the supply of carbon-based molecules used for synthetic materials including plastics, oils, medicines, and glues. To provide for future society, innovations are needed for the conversion of waste carbon (CO2) into organic carbon useful for materials. Chemical production directly from photosynthesis is a nascent technology, with great promise for capture of CO2 using sunlight. To improve low yields, it has been proposed that photosynthetic capacity can be increased by a relaxation of bottlenecks inherent to growth. The limits of carbon partitioning away from growth within the cell and the effect of partitioning on carbon fixation are not well known. Here we show that expressing genes in a pathway between carbon fixation and pyruvate increases partitioning to 2,3-butanediol (23BD) and leads to a 1.8-fold increase in total carbon yield in the cyanobacterium Synechococcus elongatus PCC 7942. Specific 2,3-butanediol production increases 2.4-fold. As partitioning increases beyond 30%, it leads to a steep decline in total carbon yield. The data suggests a local maximum for carbon partitioning from the Calvin Benson cycle that is scalable with light intensity.

  18. File-based replica management

    CERN Document Server

    Kunszt, Peter Z; Stockinger, Heinz; Stockinger, Kurt

    2005-01-01

    Data replication is one of the best known strategies to achieve high levels of availability and fault tolerance, as well as minimal access times for large, distributed user communities using a world-wide Data Grid. In certain scientific application domains, the data volume can reach the order of several petabytes; in these domains, data replication and access optimization play an important role in the manageability and usability of the Grid. In this paper, we present the design and implementation of a replica management Grid middleware that was developed within the EDG project left bracket European Data Grid Project (EDG), http://www.eu-egee.org right bracket and is designed to be extensible so that user communities can adjust its detailed behavior according to their QoS requirements.

  19. Overview of the carbon products consortium (CPC)

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, C.L. [West Virginia Univ., Morgantown, WV (United States)

    1996-08-01

    The Carbon Products Consortium (CPC) is an industry, university, government cooperative research team which has evolved over the past seven years to produce and evaluate coal-derived feedstocks for carbon products. The members of the Carbon Products Consortium are UCAR Carbon Company, Koppers Industries, CONOCO, Aluminum Company of America, AMOCO Polymers, and West Virginia University. The Carbon and Insulation Materials Technology Group at Oak Ridge National Laboratory, Fiber Materials Inc., and BASF Corporation are affiliates of the CPC. The initial work on coal-derived nuclear graphites was supported by a grant to WVU, UCAR Carbon, and ORNL from the U.S. DOE New Production Reactor program. More recently, the CPC program has been supported through the Fossil Energy Materials program and through PETC`s Liquefaction program. The coal processing technologies involve hydrogenation, extraction by solvents such as N-methyl pyrolidone and toluene, material blending, and calcination. The breadth of carbon science expertise and manufacturing capability available in the CPC enables it to address virtually all research and development issues of importance to the carbon products industry.

  20. Alumina Carbon Refractory Products for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ 1 Scope This standard specifies the classification.techni-cal requirements,test methods,inspection rules,packing,marking,transportation,storage and quality certificate of alumina carbon refractory products for continuous casting.

  1. PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Dady Dadyburjor; Philip R. Biedler; Chong Chen; L. Mitchell Clendenin; Manoj Katakdaunde; Elliot B. Kennel; Nathan D. King; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2004-08-31

    This Department of Energy National Energy Technology Laboratory sponsored project developed carbon products, using mildly hydrogenated solvents to extract the organic portion of coal to create synthetic pitches, cokes, carbon foam and carbon fibers. The focus of this effort was on development of lower cost solvents, milder hydrogenation conditions and improved yield in order to enable practical production of these products. This technology is needed because of the long-term decline in production of domestic feedstocks such as petroleum pitch and coal tar pitch. Currently, carbon products represents a market of roughly 5 million tons domestically, and 19 million tons worldwide. Carbon products are mainly derived from feedstocks such as petroleum pitch and coal tar pitch. The domestic supply of petroleum pitch is declining because of the rising price of liquid fuels, which has caused US refineries to maximize liquid fuel production. As a consequence, the long term trend has a decline in production of petroleum pitch over the past 20 years. The production of coal tar pitch, as in the case of petroleum pitch, has likewise declined significantly over the past two decades. Coal tar pitch is a byproduct of metallurgical grade coke (metcoke) production. In this industry, modern metcoke facilities are recycling coal tar as fuel in order to enhance energy efficiency and minimize environmental emissions. Metcoke production itself is dependent upon the production requirements for domestic steel. Hence, several metcoke ovens have been decommissioned over the past two decades and have not been replaced. As a consequence sources of coal tar are being taken off line and are not being replaced. The long-term trend is a reduction in coal tar pitch production. Thus import of feedstocks, mainly from Eastern Europe and China, is on the rise despite the relatively large transportation cost. To reverse this trend, a new process for producing carbon products is needed. The process must be

  2. Integrated electricity and carbon monoxide production

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, J.

    1994-03-23

    In a process for the production of carbon monoxide and electric power in an IGCC with the removal of sulphur compounds, between the outlet of quenched gas from a partial oxidation unit and a fuel inlet to a combined cycle gas turbine there is a permeable membrane unit to separate a non-permeable stream, which is utilised as a source of carbon monoxide, and a permeate stream, which is used as fuel for the gas turbine of the combined cycle unit. (author)

  3. Replica symmetry breaking for anisotropic magnets with quenched disorder

    Science.gov (United States)

    Kogan, E.; Kaveh, M.

    2017-01-01

    We study critical behaviour of a magnet with cubic anisotropy and quenched scalar disorder which is taken into account by replica method. We derive to first order in ε approximation the renormalization group equations taking into account possible replica symmetry breaking. We study the stability of the replica symmetric fixed points with respect to perturbations without (in general case) replica symmetry. However, we find that if a fixed point is stable with respect to replica symmetric deviations, it is also stable with respect to deviations without replica symmetry.

  4. Replica symmetric spin glass field theory

    Energy Technology Data Exchange (ETDEWEB)

    Temesvari, T. [Research Group for Theoretical Physics of the Hungarian Academy of Sciences, Eoetvoes University, Pazmany Peter setany 1/A, H-1117 Budapest (Hungary)]. E-mail: temtam@helios.elte.hu

    2007-06-18

    A new powerful method to test the stability of the replica symmetric spin glass phase is proposed by introducing a replicon generator function g(v). Exact symmetry arguments are used to prove that its extremum is proportional to the inverse spin glass susceptibility. By the idea of independent droplet excitations a scaling form for g(v) can be derived, whereas it can be exactly computed in the mean field Sherrington-Kirkpatrick model. It is shown by a first order perturbative treatment that the replica symmetric phase is unstable down to dimensions d < or approx. 6, and the mean field scaling function proves to be very robust. Although replica symmetry breaking is escalating for decreasing dimensionality, a mechanism caused by the infrared divergent replicon propagator may destroy the mean field picture at some low enough dimension.

  5. Replica symmetric spin glass field theory

    Science.gov (United States)

    Temesvári, T.

    2007-06-01

    A new powerful method to test the stability of the replica symmetric spin glass phase is proposed by introducing a replicon generator function g(v). Exact symmetry arguments are used to prove that its extremum is proportional to the inverse spin glass susceptibility. By the idea of independent droplet excitations a scaling form for g(v) can be derived, whereas it can be exactly computed in the mean field Sherrington-Kirkpatrick model. It is shown by a first order perturbative treatment that the replica symmetric phase is unstable down to dimensions d≲6, and the mean field scaling function proves to be very robust. Although replica symmetry breaking is escalating for decreasing dimensionality, a mechanism caused by the infrared divergent replicon propagator may destroy the mean field picture at some low enough dimension.

  6. Replica Fourier Transform: Properties and applications

    Directory of Open Access Journals (Sweden)

    A. Crisanti

    2015-02-01

    Full Text Available The Replica Fourier Transform is the generalization of the discrete Fourier Transform to quantities defined on an ultrametric tree. It finds use in conjunction of the replica method used to study thermodynamics properties of disordered systems such as spin glasses. Its definition is presented in a systematic and simple form and its use illustrated with some representative examples. In particular we give a detailed discussion of the diagonalization in the Replica Fourier Space of the Hessian matrix of the Gaussian fluctuations about the mean field saddle point of spin glass theory. The general results are finally discussed for a generic spherical spin glass model, where the Hessian can be computed analytically.

  7. Two phase decision algorithm of replica allocation

    Institute of Scientific and Technical Information of China (English)

    Zuo Chaoshu; Liu Xinsong; Wang Zheng; Li Yi

    2006-01-01

    In distributed parallel server system, location and redundancy of replicas have great influence on availability and efficiency of the system. In order to improve availahility and efficiency of the system, two phase decision algorithm of replica allocation is proposed. The algorithm which makes use of auto-regression model dynamically predicts the future count of READ and WRITE operation, and then determines location and redundancy of replicas by considering availability, CPU and bands of the network. The algorithm can not only ensure the requirement of availability, but also reduce the system resources consumed by all the operations in a great scale. Analysis and test show that communication complexity and time complexity of the algorithm satisfy O( n ), resource optimizing scale increases with the increase of READ count.

  8. Generalized gravitational entropy without replica symmetry

    Science.gov (United States)

    Camps, Joan; Kelly, William R.

    2015-03-01

    We explore several extensions of the generalized entropy construction of Lewkowycz and Maldacena, including a formulation that does not rely on preserving replica symmetry in the bulk. We show that an appropriately general ansatz for the analytically continued replica metric gives us the flexibility needed to solve the gravitational field equations beyond general relativity. As an application of this observation we study EinsteinGauss-Bonnet gravity with a small Gauss-Bonnet coupling and derive the condition that the holographic entanglement entropy must be evaluated on a surface which extremizes the Jacobson-Myers entropy. We find that in both general relativity and Einstein-Gauss-Bonnet gravity replica symmetry breaking terms are permitted by the field equations, suggesting that they do not generically vanish.

  9. Generalized gravitational entropy without replica symmetry

    CERN Document Server

    Camps, Joan

    2014-01-01

    We explore several extensions of the generalized entropy construction of Lewkowycz and Maldacena, including a formulation that does not rely on preserving replica symmetry in the bulk. We show that an appropriately general ansatz for the analytically continued replica metric gives us the flexibility needed to solve the gravitational field equations beyond general relativity. As an application of this observation we study Einstein-Gauss-Bonnet gravity with a small Gauss-Bonnet coupling and derive the condition that the holographic entanglement entropy must be evaluated on a surface which extremizes the Jacobson-Myers entropy. We find that in both general relativity and Einstein-Gauss-Bonnet gravity replica symmetry breaking terms are permitted by the field equations, suggesting that they do not generically vanish.

  10. New PHA products using unrelated carbon sources.

    Science.gov (United States)

    Matias, Fernanda; de Andrade Rodrigues, Maria Filomena

    2011-10-01

    Polyhydroxyalkanoates (PHA) are natural polyesters stored by a wide range of bacteria as carbon source reserve. Due to its chemical characteristics and biodegradability PHA can be used in chemical, medical and pharmaceutical industry for many human purposes. Over the past years, few Burkholderia species have become known for production of PHA. Aside from that, these bacteria seem to be interesting for discovering new PHA compositions which is important to different industrial applications. In this paper, we introduce two new strains which belong either to Burkholderia cepacia complex (Bcc) or genomovar-type, Burkholderia cepacia SA3J and Burkholderia contaminans I29B, both PHA producers from unrelated carbon sources. The classification was based on 16S rDNA and recA partial sequence genes and cell wall fatty acids composition. These two strains were capable to produce different types of PHA monomers or precursors. Unrelated carbon sources were used for growth and PHA accumulation. The amount of carbon source evaluated, or mixtures of them, was increased with every new experiment until it reaches eighteen carbon sources. As first bioprospection experiments staining methods were used with colony fluorescent dye Nile Red and the cell fluorescent dye Nile Blue A. Gas chromatography analysis coupled to mass spectrometry was used to evaluate the PHA composition on each strain cultivated on different carbon sources. The synthesized polymers were composed by short chain length-PHA (scl-PHA), especially polyhydroxybutyrate, and medium chain length-PHA (mcl-PHA) depending on the carbon source used.

  11. A simple asynchronous replica-exchange implementation

    CERN Document Server

    Bussi, Giovanni

    2008-01-01

    We discuss the possibility of implementing asynchronous replica-exchange (or parallel tempering) molecular dynamics. In our scheme, the exchange attempts are driven by asynchronous messages sent by one of the computing nodes, so that different replicas are allowed to perform a different number of time-steps between subsequent attempts. The implementation is simple and based on the message-passing interface (MPI). We illustrate the advantages of our scheme with respect to the standard synchronous algorithm and we benchmark it for a model Lennard-Jones liquid on an IBM-LS21 blade center cluster.

  12. Integrating Steel Production with Mineral Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Klaus Lackner; Paul Doby; Tuncel Yegulalp; Samuel Krevor; Christopher Graves

    2008-05-01

    The objectives of the project were (i) to develop a combination iron oxide production and carbon sequestration plant that will use serpentine ores as the source of iron and the extraction tailings as the storage element for CO2 disposal, (ii) the identification of locations within the US where this process may be implemented and (iii) to create a standardized process to characterize the serpentine deposits in terms of carbon disposal capacity and iron and steel production capacity. The first objective was not accomplished. The research failed to identify a technique to accelerate direct aqueous mineral carbonation, the limiting step in the integration of steel production and carbon sequestration. Objective (ii) was accomplished. It was found that the sequestration potential of the ultramafic resource surfaces in the US and Puerto Rico is approximately 4,647 Gt of CO2 or over 500 years of current US production of CO2. Lastly, a computer model was developed to investigate the impact of various system parameters (recoveries and efficiencies and capacities of different system components) and serpentinite quality as well as incorporation of CO2 from sources outside the steel industry.

  13. Carbon nanotube mass production: principles and processes.

    Science.gov (United States)

    Zhang, Qiang; Huang, Jia-Qi; Zhao, Meng-Qiang; Qian, Wei-Zhong; Wei, Fei

    2011-07-18

    Our society requires new materials for a sustainable future, and carbon nanotubes (CNTs) are among the most important advanced materials. This Review describes the state-of-the-art of CNT synthesis, with a focus on their mass-production in industry. At the nanoscale, the production of CNTs involves the self-assembly of carbon atoms into a one-dimensional tubular structure. We describe how this synthesis can be achieved on the macroscopic scale in processes akin to the continuous tonne-scale mass production of chemical products in the modern chemical industry. Our overview includes discussions on processing methods for high-purity CNTs, and the handling of heat and mass transfer problems. Manufacturing strategies for agglomerated and aligned single-/multiwalled CNTs are used as examples of the engineering science of CNT production, which includes an understanding of their growth mechanism, agglomeration mechanism, reactor design, and process intensification. We aim to provide guidelines for the production and commercialization of CNTs. Although CNTs can now be produced on the tonne scale, knowledge of the growth mechanism at the atomic scale, the relationship between CNT structure and application, and scale-up of the production of CNTs with specific chirality are still inadequate. A multidisciplinary approach is a prerequisite for the sustainable development of the CNT industry. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Properties and degradability of hydrothermal carbonization products.

    Science.gov (United States)

    Eibisch, Nina; Helfrich, Mirjam; Don, Axel; Mikutta, Robert; Kruse, Andrea; Ellerbrock, Ruth; Flessa, Heinz

    2013-09-01

    Biomass carbonized via hydrothermal carbonization (HTC) yields a liquid and a carbon (C)-rich solid called hydrochar. In soil, hydrochars may act as fertilizers and promote C sequestration. We assumed that the chemical composition of the raw material (woodchips, straw, grass cuttings, or digestate) determines the properties of the liquid and solid HTC products, including their degradability. Additionally, we investigated whether easily mineralizable organic components adsorbed on the hydrochar surface influence the degradability of the hydrochars and could be removed by repetitive washing. Carbon mineralization was measured as CO production over 30 d in aerobic incubation experiments with loamy sand. Chemical analysis revealed that most nutrients were preferably enriched in the liquid phase. The C mineralization of hydrochars from woodchips (2% of total C added), straw (3%), grass (6%), and digestate (14%) were dependent on the raw material carbonized and were significantly lower (by 60-92%; < 0.05) than the mineralization of the corresponding raw materials. Washing of the hydrochars significantly decreased mineralization of digestate-hydrochar (up to 40%) but had no effect on mineralization rates of the other three hydrochars. Variations in C mineralization between different hydrochars could be explained by multiple factors, including differences in the O/C-H/C ratios, C/N ratios, lignin content, amount of oxygen-containing functional groups, and pH. In contrast to the solids, the liquid products were highly degradable, with 61 to 89% of their dissolved organic C being mineralized within 30 d. The liquids may be treated aerobically (e.g., for nutrient recovery).

  15. New PHA products using unrelated carbon sources

    Directory of Open Access Journals (Sweden)

    Fernanda Matias

    2011-12-01

    Full Text Available Polyhydroxyalkanoates (PHA are natural polyesters stored by a wide range of bacteria as carbon source reserve. Due to its chemical characteristics and biodegradability PHA can be used in chemical, medical and pharmaceutical industry for many human purposes. Over the past years, few Burkholderia species have become known for production of PHA. Aside from that, these bacteria seem to be interesting for discovering new PHA compositions which is important to different industrial applications. In this paper, we introduce two new strains which belong either to Burkholderia cepacia complex (Bcc or genomovar-type, Burkholderia cepacia SA3J and Burkholderia contaminans I29B, both PHA producers from unrelated carbon sources. The classification was based on 16S rDNA and recA partial sequence genes and cell wall fatty acids composition. These two strains were capable to produce different types of PHA monomers or precursors. Unrelated carbon sources were used for growth and PHA accumulation. The amount of carbon source evaluated, or mixtures of them, was increased with every new experiment until it reaches eighteen carbon sources. As first bioprospection experiments staining methods were used with colony fluorescent dye Nile Red and the cell fluorescent dye Nile Blue A. Gas chromatography analysis coupled to mass spectrometry was used to evaluate the PHA composition on each strain cultivated on different carbon sources. The synthesized polymers were composed by short chain length-PHA (scl-PHA, especially polyhydroxybutyrate, and medium chain length-PHA (mcl-PHA depending on the carbon source used.

  16. Graphene nanoribbons production from flat carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Melo, W. S.; Guerini, S.; Diniz, E. M., E-mail: eduardo.diniz@ufma.br [Departamento de Física, Universidade Federal do Maranhão, São Luís - MA 65080-805 (Brazil)

    2015-11-14

    Graphene nanoribbons are of great interest for pure and applied sciences due to their unique properties which depend on the nanoribbon edges, as, for example, energy gap and antiferromagnetic coupling. Nevertheless, the synthesis of nanoribbons with well-defined edges remains a challenge. To collaborate with this subject, here we propose a new route for the production of graphene nanoribbons from flat carbon nanotubes filled with a one-dimensional chain of Fe atoms by first principles calculations based on density functional theory. Our results show that Fe-filled flat carbon nanotubes are energetically more stable than non flattened geometries. Also we find that by hydrogenation or oxygenation of the most curved region of the Fe-filled flat armchair carbon nanotube, it occurred a spontaneous production of zigzag graphene nanoribbons which have metallic or semiconducting behavior depending on the edge and size of the graphene nanoribbon. Such findings can be used to create a new method of synthesis of regular-edge carbon nanoribbons.

  17. Product carbon footprint developments and gaps

    DEFF Research Database (Denmark)

    Kronborg Jensen, Jesper

    2012-01-01

    to the existing literature of green supply chain management. Findings - The multiple initiatives for standardization each improve the understanding of standardized methods of conducting PCF. At the same time, however, important differences exist between the standards in terms of the modelling framework to be used......Purpose - Over the last decade, multiple initiatives have been undertaken to learn how to capture the carbon footprint of a supply chain at a product level. The purpose of this paper is to focus on the process of standardization to secure consistency of product carbon footprinting (PCF......) and to outline how the current developments in PCF support the need for a standardized method to measure and report environmental performance in supply chains. Design/methodology/approach - This paper is based on a literature review and a review of international standards for PCF which brings knowledge of PCF...

  18. Technique for production of graphite-carbon products

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, A.N.; Bentsianovskaya, I.A.; Filatova, V.A.; Nabokov, V.S.; Nestor, V.P.; Zil' bergleyt, I.M.

    1982-01-01

    The technique for producing carbon-graphite products that includes filtration under a pressure of 0.1-015 MPa (through graphite stock) of an aqueous carbon material with the addition of surfactant, drying, and subsequent thermal treatment, is simplified and made less lengthy. Oxidized graphite is utilized with a prior addition of 1-10% water-soluble organic substance into the suspension -molasses, hemicellulose, sugar or polyacrylamide. A 0.03-1.5% suspension of oxidized graphite is utilized, with a particle size of 0.02-0.1 mkm. Thermal processing is done in a carbon fill, at a rate of 10-20 degrees/hour to 700-800/sup 0/, maintained 2-3 hours.

  19. Catalysts for Efficient Production of Carbon Nanotubes

    Science.gov (United States)

    Sun, Ted X.; Dong, Yi

    2009-01-01

    Several metal alloys have shown promise as improved catalysts for catalytic thermal decomposition of hydrocarbon gases to produce carbon nanotubes (CNTs). Heretofore almost every experiment on the production of carbon nanotubes by this method has involved the use of iron, nickel, or cobalt as the catalyst. However, the catalytic-conversion efficiencies of these metals have been observed to be limited. The identification of better catalysts is part of a continuing program to develop means of mass production of high-quality carbon nanotubes at costs lower than those achieved thus far (as much as $100/g for purified multi-wall CNTs or $1,000/g for single-wall CNTs in year 2002). The main effort thus far in this program has been the design and implementation of a process tailored specifically for high-throughput screening of alloys for catalyzing the growth of CNTs. The process includes an integral combination of (1) formulation of libraries of catalysts, (2) synthesis of CNTs from decomposition of ethylene on powders of the alloys in a pyrolytic chemical-vapor-decomposition reactor, and (3) scanning- electron-microscope screening of the CNTs thus synthesized to evaluate the catalytic efficiencies of the alloys. Information gained in this process is put into a database and analyzed to identify promising alloy compositions, which are to be subjected to further evaluation in a subsequent round of testing. Some of these alloys have been found to catalyze the formation of carbon nano tubes from ethylene at temperatures as low as 350 to 400 C. In contrast, the temperatures typically required for prior catalysts range from 550 to 750 C.

  20. RRS: Replica Registration Service for Data Grids

    Energy Technology Data Exchange (ETDEWEB)

    Shoshani, Arie; Sim, Alex; Stockinger, Kurt

    2005-07-15

    Over the last few years various scientific experiments and Grid projects have developed different catalogs for keeping track of their data files. Some projects use specialized file catalogs, others use distributed replica catalogs to reference files at different locations. Due to this diversity of catalogs, it is very hard to manage files across Grid projects, or to replace one catalog with another. In this paper we introduce a new Grid service called the Replica Registration Service (RRS). It can be thought of as an abstraction of the concepts for registering files and their replicas. In addition to traditional single file registration operations, the RRS supports collective file registration requests and keeps persistent registration queues. This approach is of particular importance for large-scale usage where thousands of files are copied and registered. Moreover, the RRS supports a set of error directives that are triggered in case of registration failures. Our goal is to provide a single uniform interface for various file catalogs to support the registration of files across multiple Grid projects, and to make Grid clients oblivious to the specific catalog used.

  1. Production of activated carbon from TCR char

    Science.gov (United States)

    Stenzel, Fabian; Heberlein, Markus; Klinner, Tobias; Hornung, Andreas

    2016-04-01

    The utilization of char for adsorptive purposes is known since the 18th century. At that time the char was made of wood or bones and used for decoloration of fluids. In the 20th century the production of activated carbon in an industrial scale was started. The today's raw materials for activated carbon production are hard coal, peat, wood or coconut shells. All these materials entail costs especially the latter. Thus, the utilization of carbon rich residues (biomass) is an interesting economic opportunity because it is available for no costs or even can create income. The char is produced by thermo-catalytic reforming (TCR®). This process is a combination of an intermediate pyrolysis and subsequently a reforming step. During the pyrolysis step the material is decomposed in a vapor and a solid carbon enriched phase. In the second step the vapor and the solid phase get in an intensive contact and the quality of both materials is improved via the reforming process. Subsequently, the condensables are precipitated from the vapor phase and a permanent gas as well as oil is obtained. Both are suitable for heat and power production which is a clear advantage of the TCR® process. The obtained biochar from the TCR® process has special properties. This material has a very low hydrogen and oxygen content. Its stability is comparable to hard coal or anthracite. Therefore it consists almost only of carbon and ash. The latter depends from input material. Furthermore the surface structure and area can be influenced during the reforming step. Depending from temperature and residence time the number of micro pores and the surface area can be increased. Preliminary investigations with methylene blue solution have shown that a TCR® char made of digestate from anaerobic digestion has adsorptive properties. The decoloration of the solution was achieved. A further influencing factor of the adsorption performance is the particle size. Based on the results of the preliminary tests a

  2. Special steel production on common carbon steel production line

    Science.gov (United States)

    Pi, Huachun; Han, Jingtao; Hu, Haiping; Bian, Ruisheng; Kang, Jianjun; Xu, Manlin

    2004-06-01

    The equipment and technology of small bar tandem rolling line of Shijiazhuang Iron & Steel Co. in China has reached the 90's international advanced level in the 20th century, but products on the line are mostly of common carbon steel. Currently there are few steel plants in China to produce 45 steel bars for cold drawing, which is a kind of shortage product. Development of 45 steel for cold drawing has a wide market outlook in China. In this paper, continuous cooling transformation (CCT) curve of 45 steel for cold drawing used for rolling was set out first. According to the CCT curve, we determined some key temperature points such as Ac3 temperature and Ac1 temperature during the cooling procedure and discussed the precipitation microstructure at different cooling rate. Then by studying thermal treatment process of 45 steel bars for cold drawing, the influence of cooling time on microstructure was analyzed and the optimum cooling speed has been found. All results concluded from the above studies are the basis of regulating controlled cooling process of 45 steel bars for cold drawing. Finally, the feasible production process of 45 steel bars for cold drawing on common carbon steel production line combined with the field condition was recommended.

  3. Catalytic carbon membranes for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Damle, A.S.; Gangwal, S.K.

    1992-01-01

    Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

  4. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2003-03-01

    The program efforts are focused on technology and system optimization for cost reduction, commercial design development, and prototype system field trials. The program is designed to advance the carbonate fuel cell technology from full-size field test to the commercial design. FuelCell Energy, Inc. (FCE) is in the later stage of the multiyear program for development and verification of carbonate fuel cell based power plants supported by DOE/NETL with additional funding from DOD/DARPA and the FuelCell Energy team. FCE has scaled up the technology to full-size and developed DFC{reg_sign} stack and balance-of-plant (BOP) equipment technology to meet product requirements, and acquired high rate manufacturing capabilities to reduce cost. FCE has designed submegawatt (DFC300A) and megawatt (DFC1500 and DFC3000) class fuel cell products for commercialization of its DFC{reg_sign} technology. A significant progress was made during the reporting period. The reforming unit design was optimized using a three-dimensional stack simulation model. Thermal and flow uniformities of the oxidant-In flow in the stack module were improved using computational fluid dynamics based flow simulation model. The manufacturing capacity was increased. The submegawatt stack module overall cost was reduced by {approx}30% on a per kW basis. An integrated deoxidizer-prereformer design was tested successfully at submegawatt scale using fuels simulating digester gas, coal bed methane gas and peak shave (natural) gas.

  5. Improved production efficiency in cattle to reduce their carbon ...

    African Journals Online (AJOL)

    Improved production efficiency in cattle to reduce their carbon footprint for beef ... is the second most important greenhouse gas (GHG) after carbon dioxide (CO2). ... to climate change, since enteric fermentation is responsible for 28% of global ...

  6. Photobiological hydrogen production and carbon dioxide sequestration

    Science.gov (United States)

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

  7. Novel algorithm for distributed replicas management based on dynamic programming

    Institute of Scientific and Technical Information of China (English)

    Wang Tao; Lu Xianliang; Hou Mengshu

    2006-01-01

    Replicas can improve the data reliability in distributed system. However, the traditional algorithms for replica management are based on the assumption that all replicas have the uniform reliability, which is inaccurate in some actual systems. To address such problem, a novel algorithm is proposed based on dynamic programming to manage the number and distribution of replicas in different nodes. By using Markov model, replicas management is organized as a multi-phase process, and the recursion equations are provided. In this algorithm, the heterogeneity of nodes, the expense for maintaining replicas and the engaged space have been considered. Under these restricted conditions, this algorithm realizes high data reliability in a distributed system. The results of case analysis prove the feasibility of the algorithm.

  8. An Adaptive Replica Allocation Algorithm in Mobile Ad Hoc Networks

    Institute of Scientific and Technical Information of China (English)

    JingZheng; JinshuSu; KanYang

    2004-01-01

    In mobile ad hoc networks (MANET), nodes move freely and the distribution of access requests changes dynamically. Replica allocation in such a dynamic environment is a significant challenge. In this paoer, a dynamic adaptive replica allocation algorithm that can adapt to the nodes motion is proposed to minimize the communication cost of object access. When changes occur in the access requests of the object or the network topology, each replica node collects access requests from its neighbors and makes decisions locally to expand replica to neighbors or to relinquish the replica. The algorithm dynamically adapts the replica allocation scheme to a local optimal one. Simulation results show that our algorithms efficiently reduce the communication cost of object access in MANET environment.

  9. Method for production of carbon nanofiber mat or carbon paper

    Science.gov (United States)

    Naskar, Amit K.

    2015-08-04

    Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

  10. Method for production of carbon nanofiber mat or carbon paper

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K.

    2015-08-04

    Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

  11. An Arbitrary 2D Structured Replica Control Protocol

    OpenAIRE

    Basmadjian, Robert; Meer, Hermann,

    2011-01-01

    Traditional replication protocols that logically arrange the replicas into a specific structure have reasonable availability, lower communication cost as well as system load than those that do not require any logical organisation of replicas. We propose in this paper the A2DS protocol: a single protocol that, unlike the existing proposed protocols, can be adapted to any 2D structure. Its read operation is carried out on any replica of every level of the structure whereas write operations are ...

  12. Exchange frequency in replica exchange molecular dynamics

    Science.gov (United States)

    Sindhikara, Daniel; Meng, Yilin; Roitberg, Adrian E.

    2008-01-01

    The effect of the exchange-attempt frequency on sampling efficiency is studied in replica exchange molecular dynamics (REMD). We show that sampling efficiency increases with increasing exchange-attempt frequency. This conclusion is contrary to a commonly expressed view in REMD. Five peptides (1-21 residues long) are studied with a spectrum of exchange-attempt rates. Convergence rates are gauged by comparing ensemble properties between fixed length test REMD simulations and longer reference simulations. To show the fundamental correlation between exchange frequency and convergence time, a simple model is designed and studied, displaying the same basic behavior of much more complex systems.

  13. Reliability of the impression replica technique.

    Science.gov (United States)

    Falk, Anders; Vult von Steyern, Per; Fransson, Håkan; Thorén, Margareta Molin

    2015-01-01

    The aim of this study was to evaluate the reliability of the impression replica technique with a four-unit zirconia fixed dental prosthesis (FDP). Marginal and internal fit were measured by repeatedly placing the FDP on an epoxy cast using light-body silicone material corresponding to cement. All measured marginal and internal fit points showed varying values. The greatest variations were seen at the most distal margin (33 μm) and at the distal abutment of the FDP (77 μm). The results showed that the technique gives moderate variations and is a useful method to evaluate marginal and internal fit.

  14. Carbon production in comet West 1975n

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, P.D.; Brune, W.H.

    1976-10-01

    Ultraviolet spectra of comet West at moderate resolution in the wavelength range 1200--3200 A were obtained with scanning spectrophotometers aboard an Aerobee 200 rocket launched 1976 March 5.49. The principal emission features observed are lines of C, O, and C/sup +/ and bands of OH, CO, CO/sup +/, and CO/sub 2//sup +/. Estimates of the production rates of OH (and thus H/sub 2/O), C, CO, and O are 9.6, 3.1, 4.2, and 11 (all in units of 10/sup 29/ s/sup -1/), respectively. These rates are consistent with photodissociation of H/sub 2/O and CO from a source in which the CO is one-third as abundant as water. The C I (/sup 1/D--/sup 1/P/sup 0/) line at 1931 A indicates that a large fraction of the carbon is produced in the metastable /sup 1/D state. While CO/sub 2/ cannot be definitively excluded, the spectroscopic evidence favors CO as the major carbon constituent of the comet. (AIP)

  15. Carbon footprints and carbon stocks reveal climate-friendly coffee production

    OpenAIRE

    Rikxoort, Henk; Schroth, Götz; Läderach, Peter; Rodríguez-Sánchez, Beatriz

    2014-01-01

    International audience; Coffee production is impacting the climate by emitting greenhouse gasses. Coffee production is also vulnerable to climate change. As a consequence, the coffee sector is interested in climate-friendly forms of coffee production, but there is no consensus of what exactly this implies. Therefore, we studied two aspects of the climate impact of coffee production: the standing carbon stocks in the production systems and the product carbon footprint, which measures the green...

  16. Vertices from replica in a random matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Brezin, E [Laboratoire de Physique Theorique, Ecole Normale Superieure, 24 rue Lhomond 75231, Paris Cedex 05 (France); Hikami, S [Department of Basic Sciences, University of Tokyo, Meguro-ku, Komaba, Tokyo 153 (Japan)

    2007-11-09

    Kontsevich's work on Airy matrix integrals has led to explicit results for the intersection numbers of the moduli space of curves. In a subsequent work Okounkov rederived these results from the edge behavior of a Gaussian matrix integral. In our work we consider the correlation functions of vertices in a Gaussian random matrix theory, with an external matrix source. We deal with operator products of the form <{pi}{sub i=1}{sup n}1/N tr M{sup k{sub i}}>, in a 1/N expansion. For large values of the powers k{sub i}, in an appropriate scaling limit relating large k's to large N, universal scaling functions are derived. Furthermore, we show that the replica method applied to characteristic polynomials of the random matrices, together with a duality exchanging N and the number of points, provides a new way to recover Kontsevich's results on these intersection numbers.

  17. Spin Glass Field Theory with Replica Fourier Transforms

    Science.gov (United States)

    Pimentel, Iveta R.; De Dominicis, Cirano

    We develop a field theory for spin glasses using Replica Fourier Transforms (RFT). We present the formalism for the case of replica symmetry and the case of replica symmetry breaking on an ultrametric tree, with the number of replicas n and the number of replica symmetry breaking steps R generic integers. We show how the RFT applied to the two-replica fields allows to construct a new basis which block-diagonalizes the four-replica mass-matrix, into the replicon, anomalous and longitudinal modes. The eigenvalues are given in terms of the mass RFT and the propagators in the RFT space are obtained by inversion of the block-diagonal matrix. The formalism allows to express any i-replica vertex in the new RFT basis and hence enables to perform a standard perturbation expansion. We apply the formalism to calculate the contribution of the Gaussian fluctuations around the Parisi's solution for the free-energy of an Ising spin glass.

  18. RESEARCH OF LIMY AND CARBONATE SYSTEM OF SUGAR PRODUCTION

    Directory of Open Access Journals (Sweden)

    N. G. Kulneva

    2012-01-01

    Full Text Available Influence of рН and temperature on activity of suspension of lime and carbonate in sugar production is investigated. Possibility of decrease in a consumption of reagents on purification of production sugar solutions is established.

  19. Product carbon footprints and their uncertainties in comparative decision contexts.

    Directory of Open Access Journals (Sweden)

    Patrik J G Henriksson

    Full Text Available In response to growing awareness of climate change, requests to establish product carbon footprints have been increasing. Product carbon footprints are life cycle assessments restricted to just one impact category, global warming. Product carbon footprint studies generate life cycle inventory results, listing the environmental emissions of greenhouse gases from a product's lifecycle, and characterize these by their global warming potentials, producing product carbon footprints that are commonly communicated as point values. In the present research we show that the uncertainties surrounding these point values necessitate more sophisticated ways of communicating product carbon footprints, using different sizes of catfish (Pangasius spp. farms in Vietnam as a case study. As most product carbon footprint studies only have a comparative meaning, we used dependent sampling to produce relative results in order to increase the power for identifying environmentally superior products. We therefore argue that product carbon footprints, supported by quantitative uncertainty estimates, should be used to test hypotheses, rather than to provide point value estimates or plain confidence intervals of products' environmental performance.

  20. Product carbon footprints and their uncertainties in comparative decision contexts.

    Science.gov (United States)

    Henriksson, Patrik J G; Heijungs, Reinout; Dao, Hai M; Phan, Lam T; de Snoo, Geert R; Guinée, Jeroen B

    2015-01-01

    In response to growing awareness of climate change, requests to establish product carbon footprints have been increasing. Product carbon footprints are life cycle assessments restricted to just one impact category, global warming. Product carbon footprint studies generate life cycle inventory results, listing the environmental emissions of greenhouse gases from a product's lifecycle, and characterize these by their global warming potentials, producing product carbon footprints that are commonly communicated as point values. In the present research we show that the uncertainties surrounding these point values necessitate more sophisticated ways of communicating product carbon footprints, using different sizes of catfish (Pangasius spp.) farms in Vietnam as a case study. As most product carbon footprint studies only have a comparative meaning, we used dependent sampling to produce relative results in order to increase the power for identifying environmentally superior products. We therefore argue that product carbon footprints, supported by quantitative uncertainty estimates, should be used to test hypotheses, rather than to provide point value estimates or plain confidence intervals of products' environmental performance.

  1. Intensification to reduce the carbon footprint of smallholder milk production

    NARCIS (Netherlands)

    Udo, Henk; Weiler, Viola; Modupeore, Ogun; Viets, Theo; Oosting, Simon

    2016-01-01

    Will the intensification of cattle-keeping lower the carbon footprint of milk production in resource-poor environments? The authors included the multiple functions of cattle in carbon footprint estimates of milk production in farming systems with different degrees of intensification in Kenya. The

  2. Fret Replica Inspection Laser Scanner (FRILS)

    Energy Technology Data Exchange (ETDEWEB)

    Kretz, S.; Hanley, K., E-mail: steve.kretz@opg.com, E-mail: kelly.hanley@opg.com [Ontario Power Generation, Inspection Maintenance and Commercial Services, Pickering, Ontario (Canada)

    2008-07-01

    In the stress analysis of flaws and artifacts found in pressure tubes, it is crucial to have detailed knowledge of the flaw geometry. Fuel channel inspections by ultrasonic or eddy current inspection methods alone cannot provide the complete required geometry information. Replicas, which are a negative impression of surface pressure tube indications, are scanned with a laser system which will provide the additional detail required. FRILS was initially developed in 1993 to establish in-house capability of profiling indications on the inside diameter surface of pressure tubes. The need of this profiling was initially a response to the discovery of fuel bundle bearing pad fretting (FBBPF) caused by flow induced fuel bundle vibration. The benefits of the system were soon realized as a tool for profiling debris type indications. Although the primary use of FRILS is to profile FBBBF and Debris Fretting, since its inception the FRILS inspection system has become an instrumental tool in flaw assessment for: Fuel Bundle Bearing Pad Frets (FBBPF); Debris Frets; Scratches; Crevice Corrosion; Oxide Jacking; Areas of surface roughness; and, Weld Profiling. Replicas are collected via acquisition from tooling on both the Channel and Gauging Apparatus for Reactors (CIGAR) and the Advanced Non-Destructive Examination (ANDE) systems. The ANDE system is a high speed data acquisition system which includes both an ultrasonic inspection tool and a replication tool. Although both of these tools were designed to be delivered with the UDM, the platform for these tools was built with flexibility allowing for adoption to other delivery systems. These tools were based on the experience of the CIGAR inspection system. The CIGAR system has also undergone many system upgrades resulting in reduced inspection times. The FRILS system - Fret Replication Inspection Laser Scanner system was developed and has been upgraded to meet the demands of the improved inspection and replication systems. FRILS

  3. Carbon dioxide free production of hydrogen

    Science.gov (United States)

    Stoppel, L.; Fehling, T.; Geißler, T.; Baake, E.; Wetzel, T.

    2017-07-01

    The present report summarizes the theoretical modelling and experimental investigation results of the study on the direct thermal methane cracking. This work is a part of the LIMTECH-Project (Liquid Metal Technologies) funded of Helmholtz Alliance and was carried out from 2012 to 2017. The Project-part B5 “CO2-free production of hydrogen” focused on experimental testing and particularly on modelling the novel methane cracking method based on liquid metal technology. The new method uses a bubble column reactor, filled with liquid metal, where both the chemical reaction of methane decomposition and the separation of gas fraction from solid carbon occur. Such reactor system was designed and built in the liquid metal laboratory (KALLA) at KIT. The influences of liquid metal temperature distribution in reactor and feed gas flow rate on methane conversion ratio were investigated experimentally at the temperature range from 930°C to 1175 °C and methane flow rate at the reactor inlet from 50 to 200 mLn/min. In parallel with experimental investigations, a thermochemical model, giving insight in the influence of the above mentioned parameters has been developed at KIT and a CFD model was developed at LUH to get an overview about the bubble dynamics in the reaction system. The influence of different bubble sizes and shapes, multi-inlet coalescence effects as well as the potential of electromagnetic stirring have been investigated.

  4. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yixin [McGill Univ., Montreal, QC (Canada)

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  5. PRODUCTION AND SCREENING OF CARBON PRODUCTS PRECURSORS FROM COAL

    Energy Technology Data Exchange (ETDEWEB)

    Caulton L. Irwin

    2001-05-31

    The authors have examined effects of blending a raw coal extract (EXT) with an extracted coal-tar pitch (ECTP). Previous reports were concerned with the addition of 15 wt% EXT, or less, on the physical characteristics of the blend and on the development of optical texture following carbonization. Two additional blends of ECTP and EXT were prepared at the 30 and 50 wt% EXT content using a procedure already described. The characteristics of the blends are presented. The density for these blended materials is not much different than the density for the blends reported earlier. The softening point temperature for the 30 wt% EXT increased to over 200 C while the softening point temperature for the 50 wt% EXT blend was too high to be determined by the Mettler method. Coke yields approximately follow the law of mixtures. The optical texture of the green cokes for the 30 and 50 wt% EXT blends is shown. Though the optical texture of the green cokes was not significantly affected where the level of EXT is 15 wt% or less, larger proportions of EXT exert a marked reduction in anisotropy. The co-processing of coal with petroleum residues or other heavy hydrocarbons at elevated temperature and pressure has received considerable attention in the research community as a means to upgrade simultaneously coal and byproducts. Heavy hydrocarbons can function as sources of hydrogen, as well as performing as a medium for dissolution and dispersion of coal fragments. However, the focus of much of the prior research has been on developing fuels, distillable liquids, or synthetic crudes. Comparatively little effort has been deliberately directed toward the production of heavier, non-distillable materials which could perform as binder and extender pitches, impregnants, or feedstocks for cokes and other carbons.

  6. 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

  7. Asynchronous replica exchange software for grid and heterogeneous computing

    Science.gov (United States)

    Gallicchio, Emilio; Xia, Junchao; Flynn, William F.; Zhang, Baofeng; Samlalsingh, Sade; Mentes, Ahmet; Levy, Ronald M.

    2015-11-01

    Parallel replica exchange sampling is an extended ensemble technique often used to accelerate the exploration of the conformational ensemble of atomistic molecular simulations of chemical systems. Inter-process communication and coordination requirements have historically discouraged the deployment of replica exchange on distributed and heterogeneous resources. Here we describe the architecture of a software (named ASyncRE) for performing asynchronous replica exchange molecular simulations on volunteered computing grids and heterogeneous high performance clusters. The asynchronous replica exchange algorithm on which the software is based avoids centralized synchronization steps and the need for direct communication between remote processes. It allows molecular dynamics threads to progress at different rates and enables parameter exchanges among arbitrary sets of replicas independently from other replicas. ASyncRE is written in Python following a modular design conducive to extensions to various replica exchange schemes and molecular dynamics engines. Applications of the software for the modeling of association equilibria of supramolecular and macromolecular complexes on BOINC campus computational grids and on the CPU/MIC heterogeneous hardware of the XSEDE Stampede supercomputer are illustrated. They show the ability of ASyncRE to utilize large grids of desktop computers running the Windows, MacOS, and/or Linux operating systems as well as collections of high performance heterogeneous hardware devices.

  8. Asynchronous Replica Exchange Software for Grid and Heterogeneous Computing

    Science.gov (United States)

    Gallicchio, Emilio; Xia, Junchao; Flynn, William F.; Zhang, Baofeng; Samlalsingh, Sade; Mentes, Ahmet; Levy, Ronald M.

    2015-01-01

    Parallel replica exchange sampling is an extended ensemble technique often used to accelerate the exploration of the conformational ensemble of atomistic molecular simulations of chemical systems. Inter-process communication and coordination requirements have historically discouraged the deployment of replica exchange on distributed and heterogeneous resources. Here we describe the architecture of a software (named ASyncRE) for performing asynchronous replica exchange molecular simulations on volunteered computing grids and heterogeneous high performance clusters. The asynchronous replica exchange algorithm on which the software is based avoids centralized synchronization steps and the need for direct communication between remote processes. It allows molecular dynamics threads to progress at different rates and enables parameter exchanges among arbitrary sets of replicas independently from other replicas. ASyncRE is written in Python following a modular design conducive to extensions to various replica exchange schemes and molecular dynamics engines. Applications of the software for the modeling of association equilibria of supramolecular and macromolecular complexes on BOINC campus computational grids and on the CPU/MIC heterogeneous hardware of the XSEDE Stampede supercomputer are illustrated. They show the ability of ASyncRE to utilize large grids of desktop computers running the Windows, MacOS, and/or Linux operating systems as well as collections of high performance heterogeneous hardware devices. PMID:27103749

  9. Response Time Optimization for Replica Selection Service in Data Grids

    Directory of Open Access Journals (Sweden)

    Husni H.E. AL-Mistarihi

    2008-01-01

    Full Text Available Problem Statement: Data Grid architecture provides a scalable infrastructure for grid services in order to manage data files and their corresponding replicas that were distributed across the globe. The grid services are designed to support a variety of data grid applications (jobs and projects. Replica selection is a high-level service that chooses a replica location from among many distributed replicas with the minimum response time for the users' jobs. Estimating the response time accurately in the grid environment is not an easy task. The current systems expose high response time in selecting the required replicas because the response time is estimated by considering the data transfer time only. Approach: We proposed a replica selection system that selects the best replica location for the users' running jobs in a minimum response time that can be estimated by considering new factors besides the data transfer time, namely, the storage access latency and the replica requests that waiting in the storage queue. Results: The performance of the proposed system was compared with a similar system that exists in the literature namely, SimpleOptimiser. The simulation results demonstrated that our system performed better than the SimpleOptimiser on an average of 6%. Conclusions: The proposed system can select the best replica location in a lesser response time than the SimpleOptimise. The efficiency of the proposed system is 6% higher than the SimpleOptimise. The efficiency level has a high impact on the quality of service that is perceived by grid users in a data grid environment where the data files are relatively big. For example, the data files produced from the scientific applications are of the size hundreds of Terabytes.

  10. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2005-03-01

    The program was designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE, formerly Energy Research Corporation) from an early state of development for stationary power plant applications. The current program efforts were focused on technology and system development, and cost reduction, leading to commercial design development and prototype system field trials. FCE, in Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations, or at distributed locations near the customers such as hospitals, schools, universities, hotels and other commercial and industrial applications. FCE has designed three different fuel cell power plant models (DFC300A, DFC1500 and DFC3000). FCE's power plants are based on its patented DFC{reg_sign} technology, where a hydrocarbon fuel is directly fed to the fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to the existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating and air conditioning. Several sub-MW power plants based on the DFC design are currently operating in Europe, Japan and the US. Several one-megawatt power plant design was verified by operation on natural gas at FCE. This plant is currently installed at a customer site in King County, WA under another US government program and is currently in operation. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and

  11. Forest and wood products role in carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Sampson, R.N.

    1997-12-31

    An evaluation of the use of U.S. forests and forest products for carbon emission mitigation is presented. The current role of forests in carbon sequestration is described in terms of regional differences and forest management techniques. The potential for increasing carbon storage by converting marginal crop and pasture land, increasing timberland growth, reducing wildfire losses, and changing timber harvest methods is examined. Post-harvest carbon flows, environmental impacts of wood products, biomass energy crops, and increased use of energy-conserving trees are reviewed for their potential in reducing or offsetting carbon emissions. It is estimated that these techniques could offset 20 to 40 percent of the carbon emitted annually in the U.S. 39 refs., 5 tabs.

  12. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2002-02-01

    The carbonate fuel cell promises highly efficient, cost-effective and environmentally superior power generation from pipeline natural gas, coal gas, biogas, and other gaseous and liquid fuels. FuelCell Energy, Inc. has been engaged in the development of this unique technology, focusing on the development of the Direct Fuel Cell (DFC{reg_sign}). The DFC{reg_sign} design incorporates the unique internal reforming feature which allows utilization of a hydrocarbon fuel directly in the fuel cell without requiring any external reforming reactor and associated heat exchange equipment. This approach upgrades waste heat to chemical energy and thereby contributes to a higher overall conversion efficiency of fuel energy to electricity with low levels of environmental emissions. Among the internal reforming options, FuelCell Energy has selected the Indirect Internal Reforming (IIR)--Direct Internal Reforming (DIR) combination as its baseline design. The IIR-DIR combination allows reforming control (and thus cooling) over the entire cell area. This results in uniform cell temperature. In the IIR-DIR stack, a reforming unit (RU) is placed in between a group of fuel cells. The hydrocarbon fuel is first fed into the RU where it is reformed partially to hydrogen and carbon monoxide fuel using heat produced by the fuel cell electrochemical reactions. The reformed gases are then fed to the DIR chamber, where the residual fuel is reformed simultaneously with the electrochemical fuel cell reactions. FuelCell Energy plans to offer commercial DFC power plants in various sizes, focusing on the subMW as well as the MW-scale units. The plan is to offer standardized, packaged DFC power plants operating on natural gas or other hydrocarbon-containing fuels for commercial sale. The power plant design will include a diesel fuel processing option to allow dual fuel applications. These power plants, which can be shop-fabricated and sited near the user, are ideally suited for distributed power

  13. Solubility Products of M(II) - Carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Grauer, Rolf; Berner, Urs [ed.

    1999-01-01

    Many solubility data for M(II) carbonates commonly compiled in tables are contradictory and sometimes obviously wrong. The quality of such data has been evaluated based on the original publications and reliable solubility constants have been selected for the carbonates of Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb with the help of cross-comparisons. (author) translated from a PSI internal report written in German in 1994 (TM-44-94-05). 5 figs., 1 tab., 68 refs.

  14. Process for the production of sodium carbonate anhydrate

    NARCIS (Netherlands)

    Oosterhof, H.; Van Rosmalen, G.M.; Witkamp, G.J.; De Graauw, J.

    2000-01-01

    The invention is directed to a process for the production of sodium carbonate-anhydrate having a bulk density of at least 800 kg/m<3>, said process comprising: providing a suspension of solid sodium carbonate and/or solid sodium bicarbonate and/or solid double salts at least comprising one of

  15. SRF Cavity Surface Topography Characterization Using Replica Techniques

    Energy Technology Data Exchange (ETDEWEB)

    C. Xu, M.J. Kelley, C.E. Reece

    2012-07-01

    To better understand the roll of topography on SRF cavity performance, we seek to obtain detailed topographic information from the curved practical cavity surfaces. Replicas taken from a cavity interior surface provide internal surface molds for fine Atomic Force Microscopy (AFM) and stylus profilometry. In this study, we confirm the replica resolution both on surface local defects such as grain boundary and etching pits and compare the surface uniform roughness with the aid of Power Spectral Density (PSD) where we can statistically obtain roughness parameters at different scales. A series of sampling locations are at the same magnetic field chosen at the same latitude on a single cell cavity to confirm the uniformity. Another series of sampling locations at different magnetic field amplitudes are chosen for this replica on the same cavity for later power loss calculation. We also show that application of the replica followed by rinsing does not adversely affect the cavity performance.

  16. Hamiltonian replica-exchange in GROMACS: a flexible implementation

    OpenAIRE

    Bussi, Giovanni

    2013-01-01

    A simple and general implementation of Hamiltonian replica exchange for the popular molecular-dynamics software GROMACS is presented. In this implementation, arbitrarily different Hamiltonians can be used for the different replicas without incurring in any significant performance penalty. The implementation was validated on a simple toy model - alanine dipeptide in water - and applied to study the rearrangement of an RNA tetraloop, where it was used to compare recently proposed force-field co...

  17. Hamiltonian replica-exchange in GROMACS: a flexible implementation

    CERN Document Server

    Bussi, Giovanni

    2013-01-01

    A simple and general implementation of Hamiltonian replica exchange for the popular molecular-dynamics software GROMACS is presented. In this implementation, arbitrarily different Hamiltonians can be used for the different replicas without incurring in any significant performance penalty. The implementation was validated on a simple toy model - alanine dipeptide in water - and applied to study the rearrangement of an RNA tetraloop, where it was used to compare recently proposed force-field corrections.

  18. Elastomer and resin replicas for sem observation of metallic materials

    OpenAIRE

    Palin-Luc, Thierry; Sellier, E.; D?Errico, F.; Vanhaeren, M.

    2002-01-01

    International audience; The replica technique is often used to study damage evolution at the surface of specimens or industrial components and understand the physicial phenomena responsible for fatigue crack initiation before failure. Replicas are usually made from acetate cellulose film. This paper presents an alternative technique generally used by archaeologists to study lithic use-wear and bone modification. A mold is made from a dental elastomer (silicon based impression material) and a ...

  19. JavaFIRE: A Replica and File System for Grids

    Science.gov (United States)

    Petek, Marko; da Silva Gomes, Diego; Resin Geyer, Claudio Fernando; Santoro, Alberto; Gowdy, Stephen

    2012-12-01

    The work is focused on the creation of a replica and file transfers system for Computational Grids inspired on the needs of the High Energy Physics (HEP). Due to the high volume of data created by the HEP experiments, an efficient file and dataset replica system may play an important role on the computing model. Data replica systems allow the creation of copies, distributed between the different storage elements on the Grid. In the HEP context, the data files are basically immutable. This eases the task of the replica system, because given sufficient local storage resources any dataset just needs to be replicated to a particular site once. Concurrent with the advent of computational Grids, another important theme in the distributed systems area that has also seen some significant interest is that of peer-to-peer networks (p2p). P2p networks are an important and evolving mechanism that eases the use of distributed computing and storage resources by end users. One common technique to achieve faster file download from possibly overloaded storage elements over congested networks is to split the files into smaller pieces. This way, each piece can be transferred from a different replica, in parallel or not, optimizing the moments when the network conditions are better suited to the transfer. The main tasks achieved by the system are: the creation of replicas, the development of a system for replicas transfer (RFT) and for replicas location (RLS) with a different architecture that the one provided by Globus and the development of a system for file transfer in pieces on computational grids with interfaces for several storage elements. The RLS uses a p2p overlay based on the Kademlia algorithm.

  20. Injection Compression Molding of Replica Molds for Nanoimprint Lithography

    Directory of Open Access Journals (Sweden)

    Keisuke Nagato

    2014-03-01

    Full Text Available As a breakthrough in the cost and durability of molds for nanoimprint lithography (NIL, replica molds are fabricated by injection compression molding (ICM. ICM is commonly used for optical disks such as DVDs or Blu-ray disks and is also a practical fabrication method for nanostructures. In this paper, I successfully demonstrated the fabrication of cycloolefin polymer replica molds with structures smaller than 60 nm by ICM. Furthermore, ultraviolet (UV-NIL using these replica molds was demonstrated. UV-cured resist was replicated over an area of 60 mm diameter. The degree of replication by UV-NIL in the first usage of each replica mold had good repeatability. Because ICM is a high-throughput, low-cost process, the replica mold can be disposed of after a certain time for UV-NIL. This method leads to a high-integrity UV-NIL process of patterned media because multiple large-area replica molds can be fabricated simultaneously.

  1. Bayesian ensemble refinement by replica simulations and reweighting.

    Science.gov (United States)

    Hummer, Gerhard; Köfinger, Jürgen

    2015-12-28

    We describe different Bayesian ensemble refinement methods, examine their interrelation, and discuss their practical application. With ensemble refinement, the properties of dynamic and partially disordered (bio)molecular structures can be characterized by integrating a wide range of experimental data, including measurements of ensemble-averaged observables. We start from a Bayesian formulation in which the posterior is a functional that ranks different configuration space distributions. By maximizing this posterior, we derive an optimal Bayesian ensemble distribution. For discrete configurations, this optimal distribution is identical to that obtained by the maximum entropy "ensemble refinement of SAXS" (EROS) formulation. Bayesian replica ensemble refinement enhances the sampling of relevant configurations by imposing restraints on averages of observables in coupled replica molecular dynamics simulations. We show that the strength of the restraints should scale linearly with the number of replicas to ensure convergence to the optimal Bayesian result in the limit of infinitely many replicas. In the "Bayesian inference of ensembles" method, we combine the replica and EROS approaches to accelerate the convergence. An adaptive algorithm can be used to sample directly from the optimal ensemble, without replicas. We discuss the incorporation of single-molecule measurements and dynamic observables such as relaxation parameters. The theoretical analysis of different Bayesian ensemble refinement approaches provides a basis for practical applications and a starting point for further investigations.

  2. Effects of Globalisation on Carbon Footprints of Products

    DEFF Research Database (Denmark)

    Herrmann, Ivan Tengbjerg; Hauschild, Michael Zwicky

    2009-01-01

    Outsourcing of production from the industrialised countries to the newly industrialised economies holds the potential to increase wealth in both places, but what are the environmental costs of the globalised manufacturing systems? This paper looks into the changes in carbon footprint...... of manufactured products when production is moved from United Kingdom or Denmark to China and uses environmental input-output analysis to calculate the carbon footprint in the bilateral trade between these countries. The results show that differences between the European and Chinese production systems can lead...

  3. Briquetting and carbonization of biomass products for the sustainable productions of activated carbons

    Science.gov (United States)

    Khorasgani, Nasrin B.; Karimibavani, Bahareh; Alamir, Mohammed; Alzahrani, Naif; McClain, Amy P.; Asmatulu, Ramazan

    2017-04-01

    One of the most environmental concerns is the climate change because of the greenhouse gasses, such as CO2, N2O, CH4, and fluorinated gases. The big majority of CO2 is coming from burning of fossil fuels to generate steam, heat and power. In order to address some of the major environmental concerns of fossil fuels, a number of different alternatives for renewable energy sources have been considered, including sunlight, wind, rain, tides and geothermal heat and biomass. In the present study, two different biomass products (three leaves and grasses) were collected from the local sources, cleaned, chopped, and mixed with corn starch as a binder prior to the briquetting process at different external loads in a metallic mold. A number of tests, including drop, ignition and mechanical compression were conducted on the prepared briquettes before and after stabilizations and carbonization processes at different conditions. The test results indicated that briquetting pressure and carbonizations are the primary factors to produce stable and durable briquettes for various industrial applications. Undergraduate students have been involved in every step of the project and observed all the details of the process during the laboratory studies, as well as data collection, analysis and presentation. This study will be useful for the future trainings of the undergraduate engineering students on the renewable energy and related technologies.

  4. Capacity and production planning with carbon emission constraints

    DEFF Research Database (Denmark)

    Govindan, Kannan; Song, Shuang; Xu, Lei

    2017-01-01

    This paper builds a two-stage, stochastic model to study capacity expansion problem in logistics under cap-and-trade and carbon tax regulations. The optimal capacity expansion and production decisions are obtained, and the effects of carbon emission regulations on capacity expansion are studied....... Through analytical study and a real case numerical analysis, we find that the carbon tax exhibits different impacts on optimal capacity expansion decisions in low tax rate and high tax rate, and the volatility of capacity investment cost has a larger impact on optimal capacity expansion than...... that of production cost....

  5. Future productivity and carbon storage limited by terrestrial nutrient availability

    Science.gov (United States)

    Wieder, William R.; Cleveland, Cory C.; Smith, W. Kolby; Todd-Brown, Katherine

    2015-06-01

    The size of the terrestrial sink remains uncertain. This uncertainty presents a challenge for projecting future climate-carbon cycle feedbacks. Terrestrial carbon storage is dependent on the availability of nitrogen for plant growth, and nitrogen limitation is increasingly included in global models. Widespread phosphorus limitation in terrestrial ecosystems may also strongly regulate the global carbon cycle, but explicit considerations of phosphorus limitation in global models are uncommon. Here we use global state-of-the-art coupled carbon-climate model projections of terrestrial net primary productivity and carbon storage from 1860-2100 estimates of annual new nutrient inputs from deposition, nitrogen fixation, and weathering; and estimates of carbon allocation and stoichiometry to evaluate how simulated CO2 fertilization effects could be constrained by nutrient availability. We find that the nutrients required for the projected increases in net primary productivity greatly exceed estimated nutrient supply rates, suggesting that projected productivity increases may be unrealistically high. Accounting for nitrogen and nitrogen-phosphorus limitation lowers projected end-of-century estimates of net primary productivity by 19% and 25%, respectively, and turns the land surface into a net source of CO2 by 2100. We conclude that potential effects of nutrient limitation must be considered in estimates of the terrestrial carbon sink strength through the twenty-first century.

  6. Replica Fourier Tansforms on Ultrametric Trees, and Block-Diagonalizing Multi-Replica Matrices

    Science.gov (United States)

    de Dominicis, C.; Carlucci, D. M.; Temesvári, T.

    1997-01-01

    The analysis of objects living on ultrametric trees, in particular the block-diagonalization of 4-replica matrices M^{α β;γ^δ}, is shown to be dramatically simplified through the introduction of properly chosen operations on those objects. These are the Replica Fourier Transforms on ultrametric trees. Those transformations are defined and used in the present work. On montre que l'analyse d'objets vivant sur un arbre ultramétrique, en particulier, la diagonalisation par blocs d'une matrice M^{α β;γ^δ} dépendant de 4-répliques, se simplifie de façon dramatique si l'on introduit les opérations appropriées sur ces objets. Ce sont les Transformées de Fourier de Répliques sur un arbre ultramétrique. Ces transformations sont définies et utilisées dans le présent travail.

  7. Management options to reduce the carbon footprint of livestock products

    DEFF Research Database (Denmark)

    Hermansen, John Erik; Kristensen, Troels

    2011-01-01

    conclude that the most important mitigation options include - better feed conversion at the system level, - use of feeds that increase soil carbon sequestration versus carbon emission, - ensure that the manure produced substitutes for synthetic fertilizer, and - use manure for bio-energy production......Livestock products carry a large carbon footprint compared with other foods, and thus there is a need to focus on how to reduce it. The major contributing factors are emissions related to feed use and manure handling as well as the nature of the land required to produce the feed in question. We can....... Basically, it is important to make sure that all beneficial interactions in the livestock system are optimized instead of focusing only on animal productivity. There is an urgent need to arrive at a sound framework for considering the interaction between land use and carbon footprints of foods....

  8. Management options to reduce the carbon footprint of livestock products

    DEFF Research Database (Denmark)

    Hermansen, John Erik; Kristensen, Troels

    2011-01-01

    conclude that the most important mitigation options include - better feed conversion at the system level, - use of feeds that increase soil carbon sequestration versus carbon emission, - ensure that the manure produced substitutes for synthetic fertilizer, and - use manure for bio-energy production......Livestock products carry a large carbon footprint compared with other foods, and thus there is a need to focus on how to reduce it. The major contributing factors are emissions related to feed use and manure handling as well as the nature of the land required to produce the feed in question. We can....... Basically, it is important to make sure that all beneficial interactions in the livestock system are optimized instead of focusing only on animal productivity. There is an urgent need to arrive at a sound framework for considering the interaction between land use and carbon footprints of foods....

  9. Carbon Footprint Analysis for a GRAPE Production Case Study

    Science.gov (United States)

    Sirca, C.; Marras, S.; Masia, S.; Duce, P.; Zara, P.; Spano, D.

    2013-12-01

    Agriculture activities can play a double role in emitting or sequestering carbon from the atmosphere. Mitigation of greenhouse gas (GHG) emissions in agriculture is one of the most urgent research subjects in the framework of enhancing environmental stewardship. However, little is known about the role of the agriculture in the global carbon balance, since most of the studies applied the Eddy Covariance technique in natural or semi-natural ecosystems to investigate their role in mitigate the anthropogenic carbon release. The application of the Eddy Covariance technique in agricultural systems could greatly improve our knowledge about their role on the global carbon budget and help in modeling the related processes. In addition, there is a growing request from producers, trade companies, and customers on the assessment of the environmental impact of a production process related to agricultural high quality products. In recent years, particular attention was put on the estimation of GHG emissions deriving from productive processes. In this context, a useful tool is the Life Cycle Assessment (LCA), which represents a methodology to estimate GHG emissions related to the entire life cycle of a product. The Carbon Footprint (CF) analysis represents a subset of the LCA, which only considers CO2 emissions with an impact on climate change. With respect to the wine industry, most of studies focused on the CF analysis related to the wine making process in the cellar, while a few studies analyzed the GHG emissions related to the grape production. The aim of this work was to quantify the CO2 emissions due to the grape production and emphasize the double role of a vineyard as a carbon sink or source. An Eddy Covariance station was set up in a representative vineyard located in the Mediterranean Basin (Sardinia, Italy) to measure the net carbon exchange between the surface and the atmosphere. The CF analysis was also conducted to compute the carbon balance of the grape production

  10. Net carbon flux in organic and conventional olive production systems

    Science.gov (United States)

    Saeid Mohamad, Ramez; Verrastro, Vincenzo; Bitar, Lina Al; Roma, Rocco; Moretti, Michele; Chami, Ziad Al

    2014-05-01

    Agricultural systems are considered as one of the most relevant sources of atmospheric carbon. However, agriculture has the potentiality to mitigate carbon dioxide mainly through soil carbon sequestration. Some agricultural practices, particularly fertilization and soil management, can play a dual role in the agricultural systems regarding the carbon cycle contributing to the emissions and to the sequestration process in the soil. Good soil and input managements affect positively Soil Organic Carbon (SOC) changes and consequently the carbon cycle. The present study aimed at comparing the carbon footprint of organic and conventional olive systems and to link it to the efficiency of both systems on carbon sequestration by calculating the net carbon flux. Data were collected at farm level through a specific and detailed questionnaire based on one hectare as a functional unit and a system boundary limited to olive production. Using LCA databases particularly ecoinvent one, IPCC GWP 100a impact assessment method was used to calculate carbon emissions from agricultural practices of both systems. Soil organic carbon has been measured, at 0-30 cm depth, based on soil analyses done at the IAMB laboratory and based on reference value of SOC, the annual change of SOC has been calculated. Substracting sequestrated carbon in the soil from the emitted on resulted in net carbon flux calculation. Results showed higher environmental impact of the organic system on Global Warming Potential (1.07 t CO2 eq. yr-1) comparing to 0.76 t CO2 eq. yr-1 in the conventional system due to the higher GHG emissions caused by manure fertilizers compared to the use of synthetic foliar fertilizers in the conventional system. However, manure was the main reason behind the higher SOC content and sequestration in the organic system. As a resultant, the organic system showed higher net carbon flux (-1.7 t C ha-1 yr-1 than -0.52 t C ha-1 yr-1 in the conventional system reflecting higher efficiency as a

  11. In situ Diagnostics During Carbon Nanotube Production by Laser Ablation

    Science.gov (United States)

    Arepalli, Sivaram

    1999-01-01

    The preliminary results of spectral analysis of the reaction zone during the carbon nanotube production by laser ablation method indicate synergetic dependence on dual laser setup. The emission spectra recorded from different regions of the laser ablated plume at different delay times from the laser pulses are used to map the temperatures of C2 and C3. These are compared with Laser Induced Fluorescence (LIF) spectra also obtained during production to model the growth mechanism of carbon nanotubes. Experiments conducted to correlate the spectral features with nanotube yields as a function of different production parameters will be discussed.

  12. Production of activated carbon from rice husk Vietnam

    Science.gov (United States)

    Korobochkin, V. V.; Tu, N. V.; Hieu, N. M.

    2016-09-01

    This work is dedicated to the production of activated carbon from rice husk from Delta of the Red River in Viet Nam. At the first stage, carbonization of a rice husk was carried out to obtain material containing 43.1% carbon and 25 % silica with a specific surface area of 51.5 m2/g. After separating of silica (the second stage), the specific surface area of the product increased to 204 m2/g and the silica content decreased to 1.23% by weight as well. The most important stage in the formation of the porous structure of the material is the activation. The products with the high specific surface area in the range of 800-1345 m2/g were obtained by activation of carbonized product with water vapour or carbon dioxide at temperatures of 700 °C and 850 °C, with varying the flow rate of the activating agent and activation time. The best results were achieved by activation of carbon material with water vapour at the flow rate of 0.08 dm3/min per 500 g of material and the temperature of 850 °C.

  13. Create a Consortium and Develop Premium Carbon Products from Coal

    Energy Technology Data Exchange (ETDEWEB)

    Frank Rusinko; John Andresen; Jennifer E. Hill; Harold H. Schobert; Bruce G. Miller

    2006-01-01

    The objective of these projects was to investigate alternative technologies for non-fuel uses of coal. Special emphasis was placed on developing premium carbon products from coal-derived feedstocks. A total of 14 projects, which are the 2003 Research Projects, are reported herein. These projects were categorized into three overall objectives. They are: (1) To explore new applications for the use of anthracite in order to improve its marketability; (2) To effectively minimize environmental damage caused by mercury emissions, CO{sub 2} emissions, and coal impounds; and (3) To continue to increase our understanding of coal properties and establish coal usage in non-fuel industries. Research was completed in laboratories throughout the United States. Most research was performed on a bench-scale level with the intent of scaling up if preliminary tests proved successful. These projects resulted in many potential applications for coal-derived feedstocks. These include: (1) Use of anthracite as a sorbent to capture CO{sub 2} emissions; (2) Use of anthracite-based carbon as a catalyst; (3) Use of processed anthracite in carbon electrodes and carbon black; (4) Use of raw coal refuse for producing activated carbon; (5) Reusable PACs to recycle captured mercury; (6) Use of combustion and gasification chars to capture mercury from coal-fired power plants; (7) Development of a synthetic coal tar enamel; (8) Use of alternative binder pitches in aluminum anodes; (9) Use of Solvent Extracted Carbon Ore (SECO) to fuel a carbon fuel cell; (10) Production of a low cost coal-derived turbostratic carbon powder for structural applications; (11) Production of high-value carbon fibers and foams via the co-processing of a low-cost coal extract pitch with well-dispersed carbon nanotubes; (12) Use of carbon from fly ash as metallurgical carbon; (13) Production of bulk carbon fiber for concrete reinforcement; and (14) Characterizing coal solvent extraction processes. Although some of the

  14. Characterization of Nb SRF cavity materials by white light interferometry and replica techniques

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chen [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); The Applied Science Department, The College of William and Mary, Williamsburg, VA 23185 (United States); Reece, Charles [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Kelley, Michael, E-mail: mkelley@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); The Applied Science Department, The College of William and Mary, Williamsburg, VA 23185 (United States)

    2013-06-01

    Much work has shown that the topography of the interior surface is an important contributor to the performance of Nb superconducting radiofrequency (SRF) accelerator cavities. Micron-scale topography is implicated in non-linear loss mechanisms that limit the useful accelerating gradient range and impact cryogenic cost. Aggressive final chemical treatments in cavity production seek to reliably obtain “smoothest” surfaces with superior performance. Process development suffers because the cavity interior surface cannot be viewed directly without cutting out pieces, rendering the cavities unavailable for further study. Here we explore replica techniques as an alternative, providing imprints of cavity internal surface that can be readily examined. A second matter is the topography measurement technique used. Atomic force microscopy (AFM) has proven successful, but too time intensive for routine use in this application. We therefore introduce white light interferometry (WLI) as an alternative approach. We examined real surfaces and their replicas, using AFM and WLI. We find that the replica/WLI is promising to provide the large majority of the desired information, recognizing that a trade-off is being made between best lateral resolution (AFM) and the opportunity to examine much more surface area (WLI).

  15. Hamiltonian replica exchange molecular dynamics using soft-core interactions.

    Science.gov (United States)

    Hritz, Jozef; Oostenbrink, Chris

    2008-04-14

    To overcome the problem of insufficient conformational sampling within biomolecular simulations, we have developed a novel Hamiltonian replica exchange molecular dynamics (H-REMD) scheme that uses soft-core interactions between those parts of the system that contribute most to high energy barriers. The advantage of this approach over other H-REMD schemes is the possibility to use a relatively small number of replicas with locally larger differences between the individual Hamiltonians. Because soft-core potentials are almost the same as regular ones at longer distances, most of the interactions between atoms of perturbed parts will only be slightly changed. Rather, the strong repulsion between atoms that are close in space, which in many cases results in high energy barriers, is weakened within higher replicas of our proposed scheme. In addition to the soft-core interactions, we proposed to include multiple replicas using the same Hamiltonian/level of softness. We have tested the new protocol on the GTP and 8-Br-GTP molecules, which are known to have high energy barriers between the anti and syn conformation of the base with respect to the sugar moiety. During two 25 ns MD simulations of both systems the transition from the more stable to the less stable (but still experimentally observed) conformation is not seen at all. Also temperature REMD over 50 replicas for 1 ns did not show any transition at room temperature. On the other hand, more than 20 of such transitions are observed in H-REMD using six replicas (at three different Hamiltonians) during 6.8 ns per replica for GTP and 12 replicas (at six different Hamiltonians) during 8.7 ns per replica for 8-Br-GTP. The large increase in sampling efficiency was obtained from an optimized H-REMD scheme involving soft-core potentials, with multiple simulations using the same level of softness. The optimization of the scheme was performed by fast mimicking [J. Hritz and C. Oostenbrink, J. Chem. Phys. 127, 204104 (2007)].

  16. Low carbon fuel and chemical production from waste gases

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, S.; Liew, F.M.; Daniell, J.; Koepke, M. [LanzaTech, Ltd., Auckland (New Zealand)

    2012-07-01

    LanzaTech has developed a gas fermentation platform for the production of alter native transport fuels and commodity chemicals from carbon monoxide, hydrogen and carbon dioxide containing gases. LanzaTech technology uses these gases in place of sugars as the carbon and energy source for fermentation thereby allowing a broad spectrum of resources to be considered as an input for product synthesis. At the core of the Lanzatech process is a proprietary microbe capable of using gases as the only carbon and energy input for product synthesis. To harness this capability for the manufacture of a diverse range of commercially valuable products, the company has developed a robust synthetic biology platform to enable a variety of novel molecules to be synthesised via gas fermentation. LanzaTech initially focused on the fermentation of industrial waste gases for fuel ethanol production. The company has been operating pilot plant that uses direct feeds of steel making off gas for ethanol production for over 24 months. This platform technology has been further successfully demonstrated using a broad range of gas inputs including gasified biomass and reformed natural gas. LanzaTech has developed the fermentation, engineering and control systems necessary to efficiently convert gases to valuable products. A precommercial demonstration scale unit processing steel mill waste gases was commissioned in China during the 2{sup nd} quarter of 2012. Subsequent scale-up of this facility is projected for the 2013 and will represent the first world scale non-food based low carbon ethanol project. More recently LanzaTech has developed proprietary microbial catalysts capable of converting carbon dioxide in the presence of hydrogen directly to value added chemicals, where-in CO{sub 2} is the sole source of carbon for product synthesis. Integrating the LanzaTech technology into a number of industrial facilities, such as steel mills, oil refineries and other industries that emit Carbon bearing

  17. The production, storage, and flow of carbon in Amazonian forests

    Science.gov (United States)

    Malhi, Yadvinder; Saatchi, Sassan; Girardin, Cecile; Aragão, Luiz E. O. C.

    The carbon stores and dynamics of tropical forests are the subject of major international scientific and policy attention. Research associated with the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) has generated substantial advances in our understanding of the cycling of carbon at selected forest sites in Brazilian Amazonia and generated new insights into how these processes may vary across the wider Amazonian region. Here we report on aspects of this new understanding. We present, in particular, a comprehensive synthesis of carbon cycling in three focal LBA sites (Manaus, Tapajõs, and Caxiuanã), drawing on studies of productivity, litterfall, respiration, physiology, and ecosystem fluxes. These studies are placed in the context of the wider Amazonian region by utilizing the results of the Amazon Forest Inventory Network (RAINFOR) and other forest plots. We discuss the basin-wide distribution of forest biomass derived by combining these plots and a suite of satellite data, and examine the dynamics of carbon cycling in the context of regional carbon stores in the forest. Particular attention is drawn to the strong relationship between forest productivity and turnover, which suggests that higher levels of forest productivity increase forest dynamism rather than forest biomass. We conclude by discussing what the scientific priorities should be for a synthetic region-wide understanding of the carbon dynamics and stores of Amazonian forests.

  18. The production of phytolith-occluded carbon in China's forests: implications to biogeochemical carbon sequestration.

    Science.gov (United States)

    Song, Zhaoliang; Liu, Hongyan; Li, Beilei; Yang, Xiaomin

    2013-09-01

    The persistent terrestrial carbon sink regulates long-term climate change, but its size, location, and mechanisms remain uncertain. One of the most promising terrestrial biogeochemical carbon sequestration mechanisms is the occlusion of carbon within phytoliths, the silicified features that deposit within plant tissues. Using phytolith content-biogenic silica content transfer function obtained from our investigation, in combination with published silica content and aboveground net primary productivity (ANPP) data of leaf litter and herb layer in China's forests, we estimated the production of phytolith-occluded carbon (PhytOC) in China's forests. The present annual phytolith carbon sink in China's forests is 1.7 ± 0.4 Tg CO2  yr(-1) , 30% of which is contributed by bamboo because the production flux of PhytOC through tree leaf litter for bamboo is 3-80 times higher than that of other forest types. As a result of national and international bamboo afforestation and reforestation, the potential of phytolith carbon sink for China's forests and world's bamboo can reach 6.8 ± 1.5 and 27.0 ± 6.1 Tg CO2  yr(-1) , respectively. Forest management practices such as bamboo afforestation and reforestation may significantly enhance the long-term terrestrial carbon sink and contribute to mitigation of global climate warming. © 2013 John Wiley & Sons Ltd.

  19. Analysis on Availability of the Carbon Element in Alcohol Production

    Institute of Scientific and Technical Information of China (English)

    郭素荣; 蒋大和; 寇刘秀; 陆雍森

    2006-01-01

    According to the concept of circular economy, the mass integration of alcohol production was investigated though the analysis of the carbon element contained in raw material cassava. Through the mass integration, the distillage wastewater turned into carbon resource and produced a great deal of by-product biogas while its chemical oxygen demand (COD) was reduced from 50000 mg/L to not more than 300 mg/L, the local secondary effluent standards, and other by-products such as CO2 (liquidized) and fusel oil were recovered. In the way, the consumption of raw material was only 2.2 tons cassava to produce 1 ton alcohol (96%, ψ) in the case study, much lower than the average level 2.92 t/t in China. The carbon element balance for production of alcohol was made through testing the concentrations of the carbon element of all mass flows. The results showed that the mass integration helped the availability of the carbon element increased from 44.74% to 64.75%.

  20. JV Task 90 - Activated Carbon Production from North Dakota Lignite

    Energy Technology Data Exchange (ETDEWEB)

    Steven Benson; Charlene Crocker; Rokan Zaman; Mark Musich; Edwin Olson

    2008-03-31

    The Energy & Environmental Research Center (EERC) has pursued a research program for producing activated carbon from North Dakota lignite that can be competitive with commercial-grade activated carbon. As part of this effort, small-scale production of activated carbon was produced from Fort Union lignite. A conceptual design of a commercial activated carbon production plant was drawn, and a market assessment was performed to determine likely revenue streams for the produced carbon. Activated carbon was produced from lignite coal in both laboratory-scale fixed-bed reactors and in a small pilot-scale rotary kiln. The EERC was successfully able to upgrade the laboratory-scale activated carbon production system to a pilot-scale rotary kiln system. The activated carbon produced from North Dakota lignite was superior to commercial grade DARCO{reg_sign} FGD and Rheinbraun's HOK activated coke product with respect to iodine number. The iodine number of North Dakota lignite-derived activated carbon was between 600 and 800 mg I{sub 2}/g, whereas the iodine number of DARCO FGD was between 500 and 600 mg I{sub 2}/g, and the iodine number of Rheinbraun's HOK activated coke product was around 275 mg I{sub 2}/g. The EERC performed both bench-scale and pilot-scale mercury capture tests using the activated carbon made under various optimization process conditions. For comparison, the mercury capture capability of commercial DARCO FGD was also tested. The lab-scale apparatus is a thin fixed-bed mercury-screening system, which has been used by the EERC for many mercury capture screen tests. The pilot-scale systems included two combustion units, both equipped with an electrostatic precipitator (ESP). Activated carbons were also tested in a slipstream baghouse at a Texas power plant. The results indicated that the activated carbon produced from North Dakota lignite coal is capable of removing mercury from flue gas. The tests showed that activated carbon with the greatest

  1. Carbon dioxide production during mechanical ventilation

    DEFF Research Database (Denmark)

    Henneberg, S; Söderberg, D; Groth, T

    1987-01-01

    studied CO2 production (VCO2) and oxygen consumption (VO2) in mechanically ventilated ICU patients, where CO2 stores were altered by: a) changing minute ventilation by 15%, b) reducing body temperature, and c) changing the level of sedation. Expired gases went through a mixing chamber and were analyzed...

  2. Magneto-carbonization method for production of carbon fiber, and high performance carbon fibers made thereby

    Energy Technology Data Exchange (ETDEWEB)

    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%.

  3. Biological productivity and carbon cycling in the Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Primary production, bacterial production, particulate organic carbon fluxes and organic carbon burial rates were quantified during the summer period of 1999 in the Arctic Ocean via 14C uptake, 3H uptake, 234Th/238U disequilibrium and 210Pbex dating, respectively. The integrated primary production in the water column was as high as 197 mmolC/(m2@d) in the Chukchi shelf and was 3.8 mmolC/(m2@d) in the Canada Basin. These rates are higher than those reported previously. The ratios of bacterial production to primary production in the study region were higher than 0.5, indicating that microbial activity is not depressed but important in cold Arctic waters. 234Th/238U disequilibria were evident at the station in the Canada Basin. The presence of significant 234Th deficiency suggested that scavenging and removal processes are also important to biogeochemical cycles of trace elements in the Arctic Ocean. Particulate organic carbon export flux was estimated to be 1.0 mmolC/(m2@d). Measurements of sediment excess 210Pb profile in the Chukchi shelf allowed us to estimate the amount of organic carbon buried in the bottom sediment, which ranged from 25 to 35 mmolC/(m2@d) and represented about 59%-82% of the mean primary production in the euphotic zone. Overall, our results indicated that the Arctic Ocean has active carbon cycling and is not a biological desert as previously believed. Therefore, the Arctic Ocean may play an important role in the global carbon cycle and climate change.

  4. Carbon nano structures: Production and characterization

    Science.gov (United States)

    Beig Agha, Rosa

    L'objectif de ce memoire est de preparer et de caracteriser des nanostructures de carbone (CNS -- Carbon Nanostructures, en licence a l'Institut de recherche sur l'hydrogene, Quebec, Canada), un carbone avec un plus grand degre de graphitisation et une meilleure porosite. Le Chapitre 1 est une description generale des PEMFCs (PEMFC -- Polymer Electrolyte Membrane Fuel Cell) et plus particulierement des CNS comme support de catalyseurs, leur synthese et purification. Le Chapitre 2 decrit plus en details la methode de synthese et la purification des CNS, la theorie de formation des nanostructures et les differentes techniques de caracterisation que nous avons utilises telles que la diffraction aux rayons-X (XRD -- X-ray diffraction), la microscopie electronique a transmission (TEM -- transmission electron microscope ), la spectroscopie Raman, les isothermes d'adsorption d'azote a 77 K (analyse BET, t-plot, DFT), l'intrusion au mercure, et l'analyse thermogravimetrique (TGA -- thermogravimetric analysis). Le Chapitre 3 presente les resultats obtenus a chaque etape de la synthese des CNS et avec des echantillons produits a l'aide d'un broyeur de type SPEXRTM (SPEX/CertiPrep 8000D) et d'un broyeur de type planetaire (Fritsch Pulverisette 5). La difference essentielle entre ces deux types de broyeur est la facon avec laquelle les materiaux sont broyes. Le broyeur de type SPEX secoue le creuset contenant les materiaux et des billes d'acier selon 3 axes produisant ainsi des impacts de tres grande energie. Le broyeur planetaire quant a lui fait tourner et deplace le creuset contenant les materiaux et des billes d'acier selon 2 axes (plan). Les materiaux sont donc broyes differemment et l'objectif est de voir si les CNS produits ont les memes structures et proprietes. Lors de nos travaux nous avons ete confrontes a un probleme majeur. Nous n'arrivions pas a reproduire les CNS dont la methode de synthese a originellement ete developpee dans les laboratoires de l'Institut de

  5. Calcium Carbonate Production by Coccolithophorid Alge in Long Term Carbon Dioxide Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    V. J. Fabry

    2006-09-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  6. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    V.J. Fabry

    2004-10-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds or bioreactors to abate CO{sub 2} emissions from power plants.

  7. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM CARBON DIOXIDE SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    V. J. Fabry

    2003-10-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds or bioreactors to abate CO{sub 2} emissions from power plants.

  8. CALCIUM CARBONATE PRODUCTION BY COCCOLITHAPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    V. J.Fabry

    2004-01-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  9. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    V.J. Fabry

    2004-04-26

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids single-celled, marine algae that are the major global producers of calcium carbonate to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  10. Time evolution of the autocorrelation function in dynamical replica theory

    Science.gov (United States)

    Sakata, A.

    2013-04-01

    Asynchronous dynamics given by the master equation in the Sherrington-Kirkpatrick (SK) spin-glass model is studied based on dynamical replica theory (DRT) with an extension to take into account the autocorrelation function. The dynamical behaviour of the system is approximately described by dynamical equations of the macroscopic quantities: magnetization, energy contributed by randomness and the autocorrelation function. The dynamical equations under the replica symmetry assumption are derived by introducing the subshell equipartitioning assumption and exploiting the replica method. The obtained dynamical equations are compared with Monte Carlo simulations, and it is demonstrated that the proposed formula describes well the time evolution of the autocorrelation function in some parameter regions. The study offers a reasonable description of the autocorrelation function in the SK spin-glass system.

  11. Carbon footprint and ammonia emissions of California beef production systems.

    Science.gov (United States)

    Stackhouse-Lawson, K R; Rotz, C A; Oltjen, J W; Mitloehner, F M

    2012-12-01

    Beef production is a recognized source of greenhouse gas (GHG) and ammonia (NH(3)) emissions; however, little information exists on the net emissions from beef production systems. A partial life cycle assessment (LCA) was conducted using the Integrated Farm System Model (IFSM) to estimate GHG and NH(3) emissions from representative beef production systems in California. The IFSM is a process-level farm model that simulates crop growth, feed production and use, animal growth, and the return of manure nutrients back to the land to predict the environmental impacts and economics of production systems. Ammonia emissions are determined by summing the emissions from animal housing facilities, manure storage, field applied manure, and direct deposits of manure on pasture and rangeland. All important sources and sinks of methane, nitrous oxide, and carbon dioxide are predicted from primary and secondary emission sources. Primary sources include enteric fermentation, manure, cropland used in feed production, and fuel combustion. Secondary emissions occur during the production of resources used on the farm, which include fuel, electricity, machinery, fertilizer, and purchased animals. The carbon footprint is the net exchange of all GHG in carbon dioxide equivalent (CO(2)e) units per kg of HCW produced. Simulated beef production systems included cow-calf, stocker, and feedlot phases for the traditional British beef breeds and calf ranch and feedlot phases for Holstein steers. An evaluation of differing production management strategies resulted in ammonia emissions ranging from 98 ± 13 to 141 ± 27 g/kg HCW and carbon footprints of 10.7 ± 1.4 to 22.6 ± 2.0 kg CO(2)e/kg HCW. Within the British beef production cycle, the cow-calf phase was responsible for 69 to 72% of total GHG emissions with 17 to 27% from feedlot sources. Holstein steers that entered the beef production system as a by-product of dairy production had the lowest carbon footprint because the emissions

  12. Production Scale-Up or Activated Carbons for Ultracapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Steven D. Dietz

    2007-01-10

    Transportation use accounts for 67% of the petroleum consumption in the US. Electric and hybrid vehicles are promising technologies for decreasing our dependence on petroleum, and this is the objective of the FreedomCAR & Vehicle Technologies Program. Inexpensive and efficient energy storage devices are needed for electric and hybrid vehicle to be economically viable, and ultracapacitors are a leading energy storage technology being investigated by the FreedomCAR program. The most important parameter in determining the power and energy density of a carbon-based ultracapacitor is the amount of surface area accessible to the electrolyte, which is primarily determined by the pore size distribution. The major problems with current carbons are that their pore size distribution is not optimized for liquid electrolytes and the best carbons are very expensive. TDA Research, Inc. (TDA) has developed methods to prepare porous carbons with tunable pore size distributions from inexpensive carbohydrate based precursors. The use of low-cost feedstocks and processing steps greatly lowers the production costs. During this project with the assistance of Maxwell Technologies, we found that an impurity was limiting the performance of our carbon and the major impurity found was sulfur. A new carbon with low sulfur content was made and found that the performance of the carbon was greatly improved. We also scaled-up the process to pre-production levels and we are currently able to produce 0.25 tons/year of activated carbon. We could easily double this amount by purchasing a second rotary kiln. More importantly, we are working with MeadWestvaco on a Joint Development Agreement to scale-up the process to produce hundreds of tons of high quality, inexpensive carbon per year based on our processes.

  13. Tracking urban carbon footprints from production and consumption perspectives

    Science.gov (United States)

    Lin, Jianyi; Hu, Yuanchao; Cui, Shenghui; Kang, Jiefeng; Ramaswami, Anu

    2015-05-01

    Cities are hotspots of socio-economic activities and greenhouse gas emissions. The aim of this study was to extend the research range of the urban carbon footprint (CF) to cover emissions embodied in products traded among regions and intra-city sectors. Using Xiamen City as a study case, the total urban-related emissions were evaluated, and the carbon flows among regions and intra-city sectors were tracked. Then five urban CF accountings were evaluated, including purely geographic accounting (PGA), community-wide infrastructure footprint (CIF), and consumption-based footprint (CBF) methods, as well as the newly defined production-based footprint (PBF) and purely production footprint (PPF). Research results show that the total urban-related emissions of Xiamen City in 2010 were 55.2 Mt CO2e/y, of which total carbon flow among regions or intra-city sectors accounted for 53.7 Mt CO2e/y. Within the total carbon flow, import and export respectively accounted for 59 and 65%, highlighting the importance of emissions embodied in trade. By regional trade balance, North America and Europe were the largest net carbon exported-to regions, and Mainland China and Taiwan the largest net carbon imported-from regions. Among intra-sector carbon flows, manufacturing was the largest emission-consuming sector of the total urban carbon flow, accounting for 77.4, and 98% of carbon export was through industrial products trade. By the PBF, PPF, CIF, PGA and CBF methods, the urban CFs were respectively 53.7 Mt CO2e/y, 44.8 Mt CO2e/y, 28.4 Mt CO2e/y, 23.7 Mt CO2e/y, and 19.0 Mt CO2e/y, so all of the other four CFs were higher than the CBF. All of these results indicate that urban carbon mitigation must consider the supply chain management of imported goods, the production efficiency within the city, the consumption patterns of urban consumers, and the responsibility of the ultimate consumers outside the city.

  14. Improvements in Production of Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Balzano, Leandro; Resasco, Daniel E.

    2009-01-01

    A continuing program of research and development has been directed toward improvement of a prior batch process in which single-walled carbon nanotubes are formed by catalytic disproportionation of carbon monoxide in a fluidized-bed reactor. The overall effect of the improvements has been to make progress toward converting the process from a batch mode to a continuous mode and to scaling of production to larger quantities. Efforts have also been made to optimize associated purification and dispersion post processes to make them effective at large scales and to investigate means of incorporating the purified products into composite materials. The ultimate purpose of the program is to enable the production of high-quality single-walled carbon nanotubes in quantities large enough and at costs low enough to foster the further development of practical applications. The fluidized bed used in this process contains mixed-metal catalyst particles. The choice of the catalyst and the operating conditions is such that the yield of single-walled carbon nanotubes, relative to all forms of carbon (including carbon fibers, multi-walled carbon nanotubes, and graphite) produced in the disproportionation reaction is more than 90 weight percent. After the reaction, the nanotubes are dispersed in various solvents in preparation for end use, which typically involves blending into a plastic, ceramic, or other matrix to form a composite material. Notwithstanding the batch nature of the unmodified prior fluidized-bed process, the fluidized-bed reactor operates in a continuous mode during the process. The operation is almost entirely automated, utilizing mass flow controllers, a control computer running software specific to the process, and other equipment. Moreover, an important inherent advantage of fluidized- bed reactors in general is that solid particles can be added to and removed from fluidized beds during operation. For these reasons, the process and equipment were amenable to

  15. Fractographic ceramic failure analysis using the replica technique

    Science.gov (United States)

    Scherrer, Susanne S.; Quinn, Janet B.; Quinn, George D.; Anselm Wiskott, H. W.

    2007-01-01

    Objectives To demonstrate the effectiveness of in vivo replicas of fractured ceramic surfaces for descriptive fractography as applied to the analysis of clinical failures. Methods The fracture surface topography of partially failed veneering ceramic of a Procera Alumina molar and an In Ceram Zirconia premolar were examined utilizing gold-coated epoxy poured replicas viewed using scanning electron microscopy. The replicas were inspected for fractographic features such as hackle, wake hackle, twist hackle, compression curl and arrest lines for determination of the direction of crack propagation and location of the origin. Results For both veneering ceramics, replicas provided an excellent reproduction of the fractured surfaces. Fine details including all characteristic fracture features produced by the interaction of the advancing crack with the material's microstructure could be recognized. The observed features are indicators of the local direction of crack propagation and were used to trace the crack's progression back to its initial starting zone (the origin). Drawbacks of replicas such as artifacts (air bubbles) or imperfections resulting from inadequate epoxy pouring were noted but not critical for the overall analysis of the fractured surfaces. Significance The replica technique proved to be easy to use and allowed an excellent reproduction of failed ceramic surfaces. It should be applied before attempting to remove any failed part remaining in situ as the fracture surface may be damaged during this procedure. These two case studies are intended as an introduction for the clinical researcher in using qualitative (descriptive) fractography as a tool for understanding fracture processes in brittle restorative materials and, secondarily, to draw conclusions as to possible design inadequacies in failed restorations. PMID:17270267

  16. Photochemical production of carbon disulphide in seawater

    Science.gov (United States)

    Xie, Huixiang; Moore, Robert M.; Miller, William L.

    1998-03-01

    It is generally accepted that the ocean is an important source for atmospheric CS2, which makes a major contribution to the formation of COS in the atmosphere. The processes producing CS2 in seawater, however, are essentially unknown. We report for the first time to our knowledge that marine photochemical reactions are identified as a significant source for oceanic CS2. Apparent quantum yield spectra of CS2 production were obtained using water samples collected in the northeast Atlantic. Results indicate that it is mainly UV solar radiation (290-340 nm) which is responsible for CS2 photoproduction. The photoproduction rate of CS2 is positively correlated with absorbance at 350 nm, suggesting that the reactions are mediated by chromophoric dissolved organic matter (CDOM). Laboratory irradiations have confirmed that cysteine and cystine are efficient precursors of CS2 and that OH radicals are likely to be important intermediates. Both the field survey and laboratory work point to similar mechanisms for photochemical production of CS2 and COS in marine waters. A CS2 production rate of 0.49 Tg yr-1 for the world oceans has been estimated using the quantum yield spectra from this work and the sea surface light field provided by Leifer [1988]. This estimate is of the same order of magnitude as the present estimate of the CS2 flux from the ocean to the atmosphere based on surface saturation and wind speed.

  17. Using Carbon Isotopes in Cenozoic Soil Carbonates to Quantify Primary Productivity from Mid-Latitude Regions

    Science.gov (United States)

    Caves, J. K.; Kramer, S. H.; Ibarra, D. E.; Chamberlain, C. P.

    2015-12-01

    The carbon isotope composition of pedogenic carbonates (δ13Ccarb) from paleosols has been extensively used as a proxy to estimate atmospheric pCO2 over the Phanerozoic. However, a number of other factors - including the concentration of plant-respired CO2 and the isotopic composition of both atmospheric and plant-respired carbon - influence the δ13C of pedogenic carbonates. For example, δ13Ccarb records from the mid-latitudes in central Asia and western North America show increasing trends in δ13Ccarb despite decreasing pCO2 during the late Cenozoic, which suggests that other factors play an important role in determining the isotopic composition of pedogenic carbonates. Instead, we suggest that these records are primarily recording changes in primary productivity rather than changes in atmospheric pCO2 and therefore propose a novel use of paleosol carbonate records to understand paleo-ecosystem dynamics. Here, we compile existing paleosol carbonate records, and present three new records from Wyoming, to estimate soil respiration and primary productivity in western North America during the Paleogene and early Neogene. We observe both an overall increase in δ13Ccarb after the early Eocene, and spatially heterogeneous δ13Ccarb values across western US basins. We combine this δ13Ccarb data with compilations of atmospheric pCO2 to estimate soil respiration and plant productivity. The long-term increase in δ13Ccarb indicates a decrease in plant productivity as conditions became more arid across much of the western US, congruent with both records of regional uplift and of global cooling. Furthermore, significant spatial heterogeneity in δ13Ccarb indicates that regional factors, such as the presence of paleolakes and/or local paleotopography may have provided a second-order control on local and regional productivity. Thus, our results provide a first-order estimate linking changes in primary productivity with regional tectonics and global climatic change.

  18. A Carbon Arc Apparatus For Production Of Nanotubes In Microgravity

    Science.gov (United States)

    Alford, J. M.; Mason, G. R.; Feikema, D. A.

    2003-01-01

    Although many methods are available for production of single-walled carbon nanotubes (SWNTs), the conventional carbon arc process remains the most popular due to its simplicity and large production rate. However, high temperatures inside the carbon arc generate strong buoyancy driven convection, and it is hypothesized that the non-uniform environment created by this flow will have large effects on the growth and morphology of SWNTs produced by the arc process. Indeed, using normal gravity experiments, Marin et al. have demonstrated that changes in the buoyant convection plume produced by altering the arc electrode orientation can be used to change the diameter distribution of the SWNTs produced; an effect they attribute to changes in the temperature of the local nanotube growth environment. While these experiments present convincing evidence that buoyant convection has a strong effect on nanotube growth, normal gravity experiments are severely limited in scope. The ideal way to study the effect of buoyancy on SWNT production is to remove it completely. Toward this goal, a microgravity carbon arc reactor has been designed for use in the NASA Glenn 2.2 and 5 second drop towers. Although simple in principle, conventional carbon arc machines, which generally employ large reaction chambers and require heavy duty welding power supplies capable of supplying kilowatts of power, are not suitable for microgravity experiments. Here we describe a miniature carbon arc machine for SWNT production that fits into a conventional drop rig for use on the NASA Glenn 2.2 and 5 second drop towers, but that has a performance (production rate) that is better than most large ground-based machines.

  19. Simulating Replica Exchange: Markov State Models, Proposal Schemes, and the Infinite Swapping Limit.

    Science.gov (United States)

    Zhang, Bin W; Dai, Wei; Gallicchio, Emilio; He, Peng; Xia, Junchao; Tan, Zhiqiang; Levy, Ronald M

    2016-08-25

    Replica exchange molecular dynamics is a multicanonical simulation technique commonly used to enhance the sampling of solvated biomolecules on rugged free energy landscapes. While replica exchange is relatively easy to implement, there are many unanswered questions about how to use this technique most efficiently, especially because it is frequently the case in practice that replica exchange simulations are not fully converged. A replica exchange cycle consists of a series of molecular dynamics steps of a set of replicas moving under different Hamiltonians or at different thermodynamic states followed by one or more replica exchange attempts to swap replicas among the different states. How the replica exchange cycle is constructed affects how rapidly the system equilibrates. We have constructed a Markov state model of replica exchange (MSMRE) using long molecular dynamics simulations of a host-guest binding system as an example, in order to study how different implementations of the replica exchange cycle can affect the sampling efficiency. We analyze how the number of replica exchange attempts per cycle, the number of MD steps per cycle, and the interaction between the two parameters affects the largest implied time scale of the MSMRE simulation. The infinite swapping limit is an important concept in replica exchange. We show how to estimate the infinite swapping limit from the diagonal elements of the exchange transition matrix constructed from MSMRE "simulations of simulations" as well as from relatively short runs of the actual replica exchange simulations.

  20. Molten carbonate fuel cell product design improvement

    Energy Technology Data Exchange (ETDEWEB)

    P. Voyentzie; T. Leo; A. Kush; L. Christner; G. Carlson; C. Yuh

    1998-12-20

    Drawing on the manufacture, field test, and post-test experience of the sixteen Santa Clara Demonstration Project (SCDP) stacks, ERC is finalizing the next generation commercial entry product design. The second generation cells are 50% larger in area, 40% lighter on equal geometric area basis, and 30% thinner than the earlier design. These improvements have resulted in doubling of the full-height stack power. A low-cost and high-strength matrix has also been developed for improving product ruggedness. The low-cost advanced cell design incorporating these improvements has been refined through six short stack tests. Power production per cell of two times the SCDP maximum power operation, over ten thermal cycles, and overall operating flexibility with respect to load and thermal changes have been demonstrated in these short stack tests. An internally insulated stack enclosure has been designed and fabricated to eliminate the need for an inert gas environment during operation. ERC has acquired the capability for testing 400kW full-height direct fuel ceil (DFC) stack and balance-of-plant equipment. With the readiness of the power plant test facility, the cell package design, and the stack module, full-height stack testing has begun. The first full- height stack incorporating the post-SCDP second generation design was completed. The stack reached a power level of 253 kW, setting a world record for the highest power production from the advanced fuel cell system. Excellent performance uniformity at this power level affirmed manufacturing reproducibility of the components at the factory. This unoptimized small size test has achieved pipeline natural gas to DC electricity conversion efficiency of 47% (based on lower heating value - LHV) including the parasitic power consumed by the BOP equipment; that should translate to more than 50% efficiency in commercial operation, before employing cogeneration. The power plant system also operated smoothly. With the success of this

  1. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

    OpenAIRE

    Talhelm, Alan F.; Pregitzer, Kurt S.; Kubiske, Mark E.; Zak, Donald R.; Campany, Courtney E.; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F.

    2014-01-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 d...

  2. Sequestration of carbon dioxide with hydrogen to useful products

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael W. W.; Kelly, Robert M.; Hawkins, Aaron B.; Menon, Angeli Lal; Lipscomb, Gina Lynette Pries; Schut, Gerrit Jan

    2017-03-07

    Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

  3. Assessment of carbon pools in production forest, Pahang, Malaysia

    Science.gov (United States)

    Azian, M.; Nizam, M. S.; Samsudin, M.; Ismail, P.

    2016-11-01

    Forest is one of the main sources of carbon stock. Forest plays a key role in sustainable management by providing different aspects of forest ecosystem such as source of timber products, provide of clean water, food sources, etc. A study was conducted to assess carbon pools in selected production forest of Pahang, Malaysia. There are five main types of carbon pools that are recognized available in the forest, i.e. aboveground biomass (AGB), belowground biomass (BGB), deadwood, litter and soil; that these components of carbon pools can accumulate and release carbon into the atmosphere. Five sites with different years of logging period representing status of the forest were selected (i.e. before logging (PU), immediate after logging (P0), after 10 (P10), 20 (P20) and 30 (P30) years of logging). Twenty plots of 0.25 ha (50 m × 50 m) each were established with a total sampling area of 1.0 ha at each site. All trees with ≥10 cm diameter at breast height (dbh) were tagged, identified and measured. Soil at 0-30 cm, litter and dead wood were sampled and collected in every each of sub-plots to determine and assess carbon stocks within sites. The results indicated that AGB carbon had highest portion of carbon compared to soil, BGB, deadwood and litter, which comprised about 63% of the total carbon pools. It was followed by soil and BGB that comprised about 22% and 13%, respectively. Deadwood and litter contributes the same percentage which is about 1%. In terms of status of the forest, AGB contained the highest carbon which is range from 110.49 tC ha-1 to 164.49 tC ha-1 compared with soil (33.72 tC ha-1 to 68.51 tC ha-1), BGB tC ha-1 to 34 tC ha-1), deadwood (1.57 tC ha-1 to 5.55 tC ha-1) and litter (1.42 tC ha-1 to 2.19 tC ha-1). Results from this study will be very helpful as baseline of carbon storage in different status of forest from before harvesting to logged-over forest and the impact of harvesting on the carbon stock in Pahang and Peninsular Malaysia as a whole.

  4. Improving the process of I carbonation in sugar production

    Directory of Open Access Journals (Sweden)

    V. A. Golybin

    2016-01-01

    Full Text Available Of the total effect of the removal of non-sugars 30–36 % achieved in modern schemes extract purification, a large proportion removed by adsorption of calcium carbonate particles formed in the process of carbonation. To improve the efficiency of the purification steps juice we have proposed a two-stage carbonation I cleaned juice. Holding two stages I saturation at high pH juice is justified in view of the efficiency of adsorption treatment with calcium carbonate. To quantify the proposed option saturation performed laboratory research on plant juices derived from beet varying quality, with the definition of quality indicators to be cleansed juice at all stages of processing the raw juice in warm preliming, the combined main liming, I and II carbonation. Indicators were evaluated for juice in the sugar industry accepted methods. In comparison with the standard version of the proposed two-stage version of I carbonation with intermediate filtration improves filtration performance carbonated juice on 24–26 %, reduce the color of the purified juice to 17–23 %, the content of calcium in the 22–24 %, improve the overall treatment effect 16–19 % (relative. Improving the quality of the purified juice ensures the production of white sugar of standard quality, an increase in the cleaning effect of diffusion juice reduces the loss of sucrose in the molasses and increases the yield of the final commercial product. The proposed version of the separation processes of thermochemical conversion of non-sugars will create conditions for maximum removal by adsorption of their decay products, particularly dyes.

  5. Method for creating high carbon content products from biomass oil

    Science.gov (United States)

    Parker, Reginald; Seames, Wayne

    2012-12-18

    In a method for producing high carbon content products from biomass, a biomass oil is added to a cracking reactor vessel. The biomass oil is heated to a temperature ranging from about 100.degree. C. to about 800.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to crack the biomass oil. Tar is separated from the cracked biomass oil. The tar is heated to a temperature ranging from about 200.degree. C. to about 1500.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to reduce the tar to a high carbon content product containing at least about 50% carbon by weight.

  6. Roll-to-Roll production of carbon nanotubes based supercapacitors

    Science.gov (United States)

    Zhu, Jingyi; Childress, Anthony; Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Carbon nanomaterials provide an excellent platform for electrochemical double layer capacitors (EDLCs). However, current industrial methods for producing carbon nanotubes are expensive and thereby increase the costs of energy storage to more than 10 Wh/kg. In this regard, we developed a facile roll-to-roll production technology for scalable manufacturing of multi-walled carbon nanotubes (MWNTs) with variable density on run-of-the-mill kitchen Al foils. Our method produces MWNTs with diameter (heights) between 50-100 nm (10-100 μm), and a specific capacitance as high as ~ 100 F/g in non-aqueous electrolytes. In this talk, the fundamental challenges involved in EDLC-suitable MWNT growth, roll-to-roll production, and device manufacturing will be discussed along with electrochemical characteristics of roll-to-roll MWNTs. Research supported by NSF CMMI Grant1246800.

  7. Trade, production fragmentation, and China's carbon dioxide emissions

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Pei, Jiansuo; Yang, Cuihong

    2012-01-01

    An input-output framework is adopted to estimate China's carbon dioxide (CO2) emissions as generated by its exports in 2002. More than one half of China's exports are related to international production fragmentation. These processing exports generate relatively little value added but also relativel

  8. Field windbreaks for bioenergy production and carbon sequestration

    Science.gov (United States)

    Tree windbreaks are a multi-benefit land use with the ability to mitigate climate change by modifying the local microclimate for improved crop growth and sequestering carbon in soil and biomass. Agroforestry practices are also being considered for bioenergy production by direct combustion or produci...

  9. Thermal conversion of municipal solid waste via hydrothermal carbonization: comparison of carbonization products to products from current waste management techniques.

    Science.gov (United States)

    Lu, Xiaowei; Jordan, Beth; Berge, Nicole D

    2012-07-01

    Hydrothermal carbonization (HTC) is a novel thermal conversion process that may be a viable means for managing solid waste streams while minimizing greenhouse gas production and producing residual material with intrinsic value. HTC is a wet, relatively low temperature (180-350 °C) thermal conversion process that has been shown to convert biomass to a carbonaceous residue referred to as hydrochar. Results from batch experiments indicate HTC of representative waste materials is feasible, and results in the majority of carbon (45-75% of the initially present carbon) remaining within the hydrochar. Gas production during the batch experiments suggests that longer reaction periods may be desirable to maximize the production of energy-favorable products. If using the hydrochar for applications in which the carbon will remain stored, results suggest that the gaseous products from HTC result in fewer g CO(2)-equivalent emissions than the gases associated with landfilling, composting, and incineration. When considering the use of hydrochar as a solid fuel, more energy can be derived from the hydrochar than from the gases resulting from waste degradation during landfilling and anaerobic digestion, and from incineration of food waste. Carbon emissions resulting from the use of the hydrochar as a fuel source are smaller than those associated with incineration, suggesting HTC may serve as an environmentally beneficial alternative to incineration. The type and extent of environmental benefits derived from HTC will be dependent on hydrochar use/the purpose for HTC (e.g., energy generation or carbon storage). Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Replica calibration artefacts for optical 3D scanning of micro parts

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Carmignato, S.; Cantatore, Angela

    2009-01-01

    This work deals with development of calibration artefacts produced by using hard replica materials, achieving high quality geometrical reproduction of suitable reference artefacts, high stability, and high surface cooperativeness. An investigation was carried out using a replica material for dental...

  11. Clean Hydrogen Production. Carbon Dioxide Free Alternatives. Project Phisico2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Fierro, J. L.; Gonzalez, C.; Serrano, D.; Penelas, G.; Romero, M.; Marcos, M. J.; Rodriguez, C.

    2006-07-01

    The main goal of the PHISICO2 project, funded and promoted by Comunidad de Madrid, is the evaluation and optimisation of three different processes for the clean hydrogen production without carbon dioxide emission. Solar energy and associated Technologies are proposed to be jointly employed with the aim of improving the process efficiency and reducing the production costs. As a transition to the non-fossil fuel hydrogen economy, the thermocatalytic CO2-free production of hydrogen from natural gas will be considered. One of the most promising alternatives of this process is to develop a cheap and stable carbon-based catalyst able to efficiently decompose methane into a CO2-free hydrogen stream and solid carbon. Thus, not only pure hydrogen can be obtained through but also carbon with specific properties and commercial value can be produced. Another option to be explored is the splitting of water by means of solar light by means of two different approaches: (i) photodissociation promoted by semiconductor catalysts and (ii) thermochemical cycles in which a specific mixed oxide is first thermally reduced by sunlight and then reoxidized by steam in a second step with the parallel production of hydrogen. Indeed, option (i) implies necessarily the development of semiconductors with appropriate band-gap able to decompose water into hydrogen and oxygen in an efficient manner. Another critical issue will be the development of a strategy/concept that allows efficient separation of hydrogen and oxygen within the cell. In option (ii), the development of stable ferrites which act as the redox element of the cycle is also an important challenge. Finally, a 5 kW prototype solar engine water splitting, based on the mentioned thermochemical cycle, will developed and tested using concentrated solar light as an energy source. Moreover, thermodynamic and kinetic studies, reactor design, process optimisation, economical studies and comparison with conventional hydrogen production systems

  12. Data-Replicas Scheduler for Heterogeneous MapReduce Cluster

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2013-05-01

    Full Text Available Large scale data processing has rapidly increased in nowadays. MapReduce programming model, which is firstly mentioned in functional languages, appeared in distributed system and perform excellently in large scale data processing since 2006. Hadoop, which is the most popular framework of open-sourced MapReduce runtime environment, supplies reliable, scalable and distributed system processing large scale data across clusters of computers using this virtue programming model. In this system, files are split into many blocks and all blocks are replicated over several computers in clusters. To process these blocks efficiently, each job runs parallel and is divided into many tasks which deals with a file block. In order to fully take advantage of network bandwidth these systems, data locality is paid more and more attentions. Considering the existence of data-replica blocks, we propose a data-replicas scheduler which includes task scheduling and data allocation. The data-replicas scheduler takes fully advantage of data replicas in local Data node, reduce the costs of data transfer and improve the system performance. The results of experiments show that our scheduler not only improves the CPU ratio, but also reduces the packets that transfer in the network.

  13. Replicas in Caravaggio's paintings: the correct use of scientific analysis

    Science.gov (United States)

    Diana, Maurizio; Moioli, Pietro; Seccaroni, Claudio

    1998-05-01

    Painting techniques and materials employed by Caravaggio are analyzed by X-ray fluorescence and radiography of unquestioned genuine works and compared to replicas of his earlier work. This approach is important in the attribution of recently discovered paintings and copies from the XVII century.

  14. Replica-Based High-Performance Tuple Space Computing

    DEFF Research Database (Denmark)

    Andric, Marina; De Nicola, Rocco; Lluch Lafuente, Alberto

    2015-01-01

    We present the tuple-based coordination language RepliKlaim, which enriches Klaim with primitives for replica-aware coordination. Our overall goal is to offer suitable solutions to the challenging problems of data distribution and locality in large-scale high performance computing. In particular,...

  15. Biogenic carbon fluxes from global agricultural production and consumption

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Julie; West, Tristram O.; Le Page, Yannick LB; Kyle, G. Page; Zhang, Xuesong; Collatz, George; Imhoff, Marc L.

    2015-10-01

    Quantification of biogenic carbon fluxes from agricultural lands is needed to generate comprehensive bottom-up estimates of net carbon exchange for global and regional carbon monitoring. We estimated global agricultural carbon fluxes associated with annual crop net primary production (NPP), harvested biomass, and consumption of biomass by humans and livestock. These estimates were combined for a single estimate of net carbon exchange (NCE) and spatially distributed to 0.05 degree resolution using MODIS satellite land cover data. Global crop NPP in 2011 was estimated at 5.25 ± 0.46 Pg C yr-1, of which 2.05 ± 0.05 Pg C yr-1 was harvested and 0.54 Pg C yr-1 was collected from crop residues for livestock fodder. Total livestock feed intake in 2011 was 2.42 ± 0.21 Pg C yr-1, of which 2.31 ± 0.21 Pg C yr-1 was emitted as CO2, 0.07 ± 0.01 Pg C yr-1 was emitted as CH4, and 0.04 Pg C yr-1 was contained within milk and egg production. Livestock grazed an estimated 1.27 Pg C yr-1 in 2011, which constituted 52.4% of total feed intake. Global human food intake was 0.57 ± 0.03 Pg C yr-1 in 2011, the majority of which is respired as CO2. Completed global cropland carbon budgets accounted for the ultimate use of ca. 80% of harvested biomass. The spatial distribution of these fluxes may be used for global carbon monitoring, estimation of regional uncertainty, and for use as input to Earth system models.

  16. Production and characterization of granular activated carbon from activated sludge

    Directory of Open Access Journals (Sweden)

    Z. Al-Qodah

    2009-03-01

    Full Text Available In this study, activated sludge was used as a precursor to prepare activated carbon using sulfuric acid as a chemical activation agent. The effect of preparation conditions on the produced activated carbon characteristics as an adsorbent was investigated. The results indicate that the produced activated carbon has a highly porous structure and a specific surface area of 580 m²/g. The FT-IR analysis depicts the presence of a variety of functional groups which explain its improved adsorption behavior against pesticides. The XRD analysis reveals that the produced activated carbon has low content of inorganic constituents compared with the precursor. The adsorption isotherm data were fitted to three adsorption isotherm models and found to closely fit the BET model with R² equal 0.948 at pH 3, indicating a multilayer of pesticide adsorption. The maximum loading capacity of the produced activated carbon was 110 mg pesticides/g adsorbent and was obtained at this pH value. This maximum loading was found experimentally to steeply decrease as the solution pH increases. The obtained results show that activated sludge is a promising low cost precursor for the production of activated carbon.

  17. Synthetic fossilization of soft biological tissues and their shape-preserving transformation into silica or electron-conductive replicas.

    Science.gov (United States)

    Townson, Jason L; Lin, Yu-Shen; Chou, Stanley S; Awad, Yasmine H; Coker, Eric N; Brinker, C Jeffrey; Kaehr, Bryan

    2014-12-08

    Structural preservation of complex biological systems from the subcellular to whole organism level in robust forms, enabling dissection and imaging while preserving 3D context, represents an enduring grand challenge in biology. Here we report a simple immersion method for structurally preserving intact organisms via conformal stabilization within silica. This self-limiting process, which we refer to as silica bioreplication, occurs by condensation of water-soluble silicic acid proximally to biomolecular interfaces throughout the organism. Conformal nanoscopic silicification of all biomolecular features imparts structural rigidity enabling the preservation of shape and nano-to-macroscale dimensional features upon drying to form a biocomposite and further high temperature oxidative calcination to form silica replicas or reductive pyrolysis to form electrically conductive carbon replicas of complete organisms. The simplicity and generalizability of this approach should facilitate efforts in biological preservation and analysis and could enable the development of new classes of biomimetic composite materials.

  18. Impact of bioenergy production on carbon storage and soil functions

    Science.gov (United States)

    Prays, Nadia; Franko, Uwe

    2016-04-01

    An important renewable energy source is methane produced in biogas plants (BGPs) that convert plant material and animal excrements to biogas and a residue (BGR). If the plant material stems from crops produced specifically for that purpose, a BGP have a 'footprint' that is defined by the area of arable land needed for the production of these energy crops and the area for distributing the BGRs. The BGR can be used to fertilize these lands (reducing the need for carbon and nitrogen fertilizers), and the crop land can be managed to serve as a carbon sink, capturing atmospheric CO2. We focus on the ecological impact of different BGPs in Central Germany, with a specific interest in the long-term effect of BGR-fertilization on carbon storage within the footprint of a BGP. We therefore studied nutrient fluxes using the CANDY (CArbon and Nitrogen Dynamics) model, which processes site-specific information on soils, crops, weather, and land management to compute stocks and fluxes of carbon and nitrogen for agricultural fields. We used CANDY to calculated matter fluxes within the footprints of BGPs of different sizes, and studied the effect of the substrate mix for the BGP on the carbon dynamics of the soil. This included the land requirement of the BGR recycling when used as a fertilizer: the footprint of a BGP required for the production of the energy crop generally differs from its footprint required to take up its BGR. We demonstrate how these findings can be used to find optimal cropping choices and land management for sustainable soil use, maintaining soil fertility and other soil functions. Furthermore, site specific potentials and limitations for agricultural biogas production can be identified and applied in land-use planning.

  19. Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation

    Science.gov (United States)

    Zhang, Xiao; Li, Xueqian; Zhang, Du; Su, Neil Qiang; Yang, Weitao; Everitt, Henry O.; Liu, Jie

    2017-01-01

    Photocatalysis has not found widespread industrial adoption, in spite of decades of active research, because the challenges associated with catalyst illumination and turnover outweigh the touted advantages of replacing heat with light. A demonstration that light can control product selectivity in complex chemical reactions could prove to be transformative. Here, we show how the recently demonstrated plasmonic behaviour of rhodium nanoparticles profoundly improves their already excellent catalytic properties by simultaneously reducing the activation energy and selectively producing a desired but kinetically unfavourable product for the important carbon dioxide hydrogenation reaction. Methane is almost exclusively produced when rhodium nanoparticles are mildly illuminated as hot electrons are injected into the anti-bonding orbital of a critical intermediate, while carbon monoxide and methane are equally produced without illumination. The reduced activation energy and super-linear dependence on light intensity cause the unheated photocatalytic methane production rate to exceed the thermocatalytic rate at 350 °C. PMID:28230100

  20. Mechanisms of Carbon Nanotube Production by Laser Ablation Process

    Science.gov (United States)

    Scott, Carl D.; Arepalli, Sivaram; Nikolaev, Pavel; Smalley, Richard E.; Nocholson, Leonard S. (Technical Monitor)

    2000-01-01

    We will present possible mechanisms for nanotube production by laser oven process. Spectral emission of excited species during laser ablation of a composite graphite target is compared with that of laser irradiated C60 vapor. The similarities in the transient and spectral data suggest that fullerenes are intermediate precursors for nanotube formation. The confinement of the ablation products by means of a 25-mm diameter tube placed upstream of the target seems to improve the production and purity of nanotubes. Repeated laser pulses vaporize the amorphous/graphitic carbon and possibly catalyst particles, and dissociate fullerenes yielding additional feedstock for SWNT growth.

  1. Mineral carbonation of phosphogypsum waste for production of useful carbonate and sulfate salts

    Directory of Open Access Journals (Sweden)

    Hannu-Petteri eMattila

    2015-11-01

    Full Text Available Phosphogypsum (CaSO4·2H2O waste is produced in large amounts during phosphoric acid (H3PO4 production. Minor quantities are utilized in construction or agriculture, while most of the material is stockpiled, creating an environmental challenge to prevent pollution of natural waters. In principle, the gypsum waste could be used to capture several hundred Mt of carbon dioxide (CO2. For example, when gypsum is converted to ammonium sulfate ((NH42SO4 with ammonia (NH3 and CO2, also solid calcium carbonate (CaCO3 is generated. The ammonium sulfate can be utilized as a fertilizer or in other mineral carbonation processes that use magnesium silicate-based rock as feedstock, while calcium carbonate has various uses as e.g. filler material. The reaction extent of the described process was studied by thermodynamic modeling and experimentally as a function of reactant concentrations and temperature. Other essential properties such as purity and quality of the solid products are also followed. Conversion efficiencies of >95% calcium from phosphogypsum to calcium carbonate are obtained. Scalenohedral, rhombohedral and prismatic calcite particles can be produced, though the precipitates contain certain contaminants such as rare earth metals and sulfur from the gypsum. A reverse osmosis membrane cartridge is also tested as an alternative and energy-efficient method of concentrating the ammonium sulfate salt solution instead of the traditional evaporation of the process solution.

  2. Environmental remediation and conversion of carbon dioxide (CO(2)) into useful green products by accelerated carbonation technology.

    Science.gov (United States)

    Lim, Mihee; Han, Gi-Chun; Ahn, Ji-Whan; You, Kwang-Suk

    2010-01-01

    This paper reviews the application of carbonation technology to the environmental industry as a way of reducing carbon dioxide (CO(2)), a green house gas, including the presentation of related projects of our research group. An alternative technology to very slow natural carbonation is the co-called 'accelerated carbonation', which completes its fast reaction within few hours by using pure CO(2). Carbonation technology is widely applied to solidify or stabilize solid combustion residues from municipal solid wastes, paper mill wastes, etc. and contaminated soils, and to manufacture precipitated calcium carbonate (PCC). Carbonated products can be utilized as aggregates in the concrete industry and as alkaline fillers in the paper (or recycled paper) making industry. The quantity of captured CO(2) in carbonated products can be evaluated by measuring mass loss of heated samples by thermo-gravimetric (TG) analysis. The industrial carbonation technology could contribute to both reduction of CO(2) emissions and environmental remediation.

  3. Spontaneous versus explicit replica symmetry breaking in the theory of disordered systems

    Science.gov (United States)

    Mouhanna, D.; Tarjus, G.

    2010-05-01

    We investigate the relation between spontaneous and explicit replica symmetry breaking in the theory of disordered systems. On general ground, we prove the equivalence between the replicon operator associated with the stability of the replica-symmetric solution in the standard replica scheme and the operator signaling a breakdown of the solution with analytic field dependence in a scheme in which replica symmetry is explicitly broken by applied sources. This opens the possibility to study, via the recently developed functional renormalization group, unresolved questions related to spontaneous replica symmetry breaking and spin-glass behavior in finite-dimensional disordered systems.

  4. CREAT A CONSORTIUM AND DEVELOP PREMIUM CARBON PRODUCTS FROM COAL

    Energy Technology Data Exchange (ETDEWEB)

    John M. Andresen

    2003-08-01

    The Consortium for Premium Carbon Products from Coal, with funding from the U.S. Department of Energy's National Energy Technology Laboratory and matching funds from industry and academic institutions continued to excel in developing innovative technologies to use coal and coal-derived feedstocks to produce premium carbon product. During Budget Period 5, eleven projects were supported and sub-contracted were awarded to seven organizations. The CPCPC held two meetings and one tutorial at various locations during the year. Budget Period 5 was a time of growth for CPCPC in terms of number of proposals and funding requested from members, projects funded and participation during meetings. Although the membership was stable during the first part of Budget Period 5 an increase in new members was registered during the last months of the performance period.

  5. The role of carbonic anhydrase in hepatic glucose production.

    Science.gov (United States)

    Ismail, Ibrahim Salihu

    2016-12-14

    Considerable efforts are being made daily to discover novel therapeutic targets to better understand the mechanism for designing drugs in treating diabetes. Inhibition of hepatic gluconeogenesis by metformin remains the first line of oral therapy for managing type 2 diabetes. The link between rise in blood lactate level and reduction of hepatic glucose production with metformin usage remains to be determined. Carbonic anhydrase is proposed to be the link connecting blood lactate accumulation and inhibition of hepatic gluconeogenesis and thus could serve as a new therapeutic target for reducing hepatic glucose production. Understanding the link between rise in blood lactate level and the role of carbonic anhydrase in lactate uptake will be essential towards the development of a promising new antidiabetic medication.

  6. Natural Product Polyamines That Inhibit Human Carbonic Anhydrases

    Directory of Open Access Journals (Sweden)

    Rohan A. Davis

    2014-01-01

    Full Text Available Natural product compound collections have proven an effective way to access chemical diversity and recent findings have identified phenolic, coumarin, and polyamine natural products as atypical chemotypes that inhibit carbonic anhydrases (CAs. CA enzymes are implicated as targets of variable drug therapeutic classes and the discovery of selective, drug-like CA inhibitors is essential. Just two natural product polyamines, spermine and spermidine, have until now been investigated as CA inhibitors. In this study, five more complex natural product polyamines 1–5, derived from either marine sponge or fungi, were considered for inhibition of six different human CA isozymes of interest in therapeutic drug development. All compounds share a simple polyamine core fragment, either spermine or spermidine, yet display substantially different structure activity relationships for CA inhibition. Notably, polyamines 1–5 were submicromolar inhibitors of the cancer drug target CA IX, this is more potent than either spermine or spermidine.

  7. Bulk scale production of carbon nanofibers in an economical way

    Science.gov (United States)

    Rajarao, Ravindra; Bhat, Badekai Ramachandra

    2012-12-01

    An economical route for the scalable production of carbon nanofibers (CNFs) on a sodium chloride support has been developed. CNFs have been synthesized by chemical vapor deposition (CVD) method by using metal formate as catalyst precursors at 680°C. Products were characterized by SEM, TEM, Raman spectroscopy and XRD method. By thermal analysis, the purity of the as grown products and purified products were determined. This method avoids calcination and reduction process which was employed in commercial catalysts such as metal oxide or nitrate. The problems such as detrimental effect, environmental and even cost have been overcome by using sodium chloride as support. The yield of CNFs up to 7800 wt.% relative to the nickel catalyst has been achieved in the growth time of 15 min. The advantage of this synthesis technique is the simplicity and use of easily available low cost precursors.

  8. Ratio of Pion Kaon Production in Proton Carbon Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Andrey V. [Harvard Univ., Cambridge, MA (United States)

    2007-05-01

    The ratio of pion-kaon production by 120 GeV/c protons incident on carbon target is presented. The data was recorded with the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory. Production ratios of K++, K--, K-/K+, and π-+ are measured in 24 bins in longitudinal momentum from 20 to 90 GeV/c and transverse momentum up to 2 GeV/c. The measurement is compared to existing data sets, particle production Monte Carlo results from FLUKA-06, parametrization of proton-beryllium data at 400/450 GeV/c, and ratios measured by the MINOS experiment on the NuMI target.

  9. 40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.

    Science.gov (United States)

    2010-07-01

    ... resulting from the production of calcium carbonate by the milk of lime process and by the recovery process... calcium carbonate production subcategory. 415.300 Section 415.300 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of...

  10. 78 FR 15376 - Determinations: Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea

    Science.gov (United States)

    2013-03-11

    ... COMMISSION Determinations: Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea On the basis... Korea and the antidumping duty orders on corrosion-resistant carbon steel flat products from Germany and... Corrosion-Resistant Carbon Steel Flat Products from Germany and Korea: Investigation Nos. 701-TA-350 and...

  11. Apparatus for hydrogen and carbon production via carbon aerosol-catalyzed dissociation of hydrocarbons

    Science.gov (United States)

    Muradov, Nazim Z. (Inventor); Smith, Franklyn (Inventor); Tabatabaie-Raissi, Ali (Inventor)

    2012-01-01

    A novel process and apparatus is disclosed for sustainable, continuous production of hydrogen and carbon by catalytic dissociation or decomposition of hydrocarbons at elevated temperatures using in-situ generated carbon particles. Carbon particles are produced by decomposition of carbonaceous materials in response to an energy input. The energy input can be provided by at least one of a non-oxidative and oxidative means. The non-oxidative means of the energy input includes a high temperature source, or different types of plasma, such as, thermal, non-thermal, microwave, corona discharge, glow discharge, dielectric barrier discharge, or radiation sources, such as, electron beam, gamma, ultraviolet (UV). The oxidative means of the energy input includes oxygen, air, ozone, nitrous oxide (NO.sub.2) and other oxidizing agents. The method, apparatus and process of the present invention is applicable to any gaseous or liquid hydrocarbon fuel and it produces no or significantly less CO.sub.2 emissions compared to conventional processes.

  12. ATLAS Replica Management in Rucio: Replication Rules and Subscriptions

    CERN Document Server

    Barisits, M; The ATLAS collaboration; Garonne, V; Lassnig, M; Stewart, G; Beermann, T; Vigne, R; Goossens, L; Nairz, A; Molfetas, A

    2014-01-01

    The ATLAS Distributed Data Management system stores more than 150PB of physics data across 120 sites globally. To cope with the anticipated ATLAS workload of the coming decade, Rucio, the next-generation data management system has been developed. Replica management, as one of the keys aspects of the system, has to satisfy critical performance requirements in order to keep pace with the experiment’s high rate of continual data generation. The challenge lies in meeting these performance objectives while still giving the system users and applications a powerful toolkit to control their data workflows. In this work we present the concept, design and implementation of the replica management in Rucio. We will specifically introduce the workflows behind replication rules, their formal language definition, weighting and site selection. Furthermore we will present the subscription component, which offers functionality for users to proclaim interest in data that has not been created yet. This contribution describes t...

  13. ATLAS Replica Management in Rucio: Replication Rules and Subscriptions

    CERN Document Server

    Barisits, M; The ATLAS collaboration; Garonne, V; Lassnig, M; Stewart, G; Beermann, T; Vigne, R; Goossens, L; Nairz, A; Molfetas, A

    2013-01-01

    The ATLAS Distributed Data Management system stores more than 150PB of physics data across 120 sites globally. To cope with the anticipated ATLAS workload of the coming decade, Rucio, the next-generation data management system has been developed. Replica management, as one of the keys aspects of the system, has to satisfy critical performance requirements in order to keep pace with the experiment’s high rate of continual data generation. The challenge lies in meeting these performance objectives while still giving the system users and applications a powerful toolkit to control their data workflows. In this work we present the concept, design and implementation of the replica management in Rucio. We will specifically introduce the workflows behind replication rules, their formal language definition, weighting and site selection. Furthermore we will present the subscription component, which offers functionality for users to proclaim interest in data that has not been created yet. This contribution describes t...

  14. An adaptive range-query optimization technique with distributed replicas

    Institute of Scientific and Technical Information of China (English)

    Sayar Ahmet; Pierce Marlon; Fox C.Geoffrey

    2014-01-01

    Replication is an approach often used to speed up the execution of queries submitted to a large dataset. A compile-time/run-time approach is presented for minimizing the response time of 2-dimensional range when a distributed replica of a dataset exists. The aim is to partition the query payload (and its range) into subsets and distribute those to the replica nodes in a way that minimizes a client’s response time. However, since query size and distribution characteristics of data (data dense/sparse regions) in varying ranges are not known a priori, performing efficient load balancing and parallel processing over the unpredictable workload is difficult. A technique based on the creation and manipulation of dynamic spatial indexes for query payload estimation in distributed queries was proposed. The effectiveness of this technique was demonstrated on queries for analysis of archived earthquake-generated seismic data records.

  15. Carbon Footprint of Tree Nuts Based Consumer Products

    Directory of Open Access Journals (Sweden)

    Roberto Volpe

    2015-11-01

    Full Text Available This case study shows results of a calculation of carbon footprint (CFP resulting from the production of nuts added value products for a large consumer market. Nuts consumption is increasing in the world and so is the consumer awareness of the environmental impact of goods, hence the calculation of greenhouse gas (GHG emissions of food production is of growing importance for producers. Calculation of CO2eq emissions was performed for all stages of the production chain to the final retail point for flour, grains, paste, chocolate covered nuts and spreadable cream produced from almonds, pistachios and hazelnuts grown and transformed in Italy and for peanuts grown in Argentina and transformed in Italy. Data from literature was used to evaluate CFP of raw materials, emissions from transport and packing were calculated using existing models, while emissions deriving from transformation were calculated empirically by multiplying the power of production lines (electrical and/or thermal by its productivity. All values were reported in kg of CO2 equivalent for each kg of packed product (net weight. Resulting values ranged between 1.2 g of CO2/kg for a 100 g bag of almond to 4.8 g of CO2/kg for the 100 g bag of chocolate covered almond. The calculation procedure can be well used for similar cases of large consumer food productions.

  16. Replica symmetry breaking in cold atoms and spin glasses

    Science.gov (United States)

    Rotondo, P.; Tesio, E.; Caracciolo, S.

    2015-01-01

    We consider a system composed by N atoms trapped within a multimode cavity, whose theoretical description is captured by a disordered multimode Dicke model. We show that in the resonant, zero-field limit the system exactly realizes the Sherrington-Kirkpatrick model. Upon a redefinition of the temperature, the same dynamics is realized in the dispersive, strong-field limit. This regime also gives access to spin-glass observables which can be used to detect replica symmetry breaking.

  17. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Madhavi Nallani-Chakravartula; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2006-03-27

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the development of continuous processes for hydrogenation as well as continuous production of carbon foam and coke.

  18. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2005-06-08

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the development of continuous processes for hydrogenation as well as continuous production of carbon foam and coke.

  19. Environmental Remediation and Conversion of Carbon Dioxide (CO2 into Useful Green Products by Accelerated Carbonation Technology

    Directory of Open Access Journals (Sweden)

    Kwang-Suk You

    2010-01-01

    Full Text Available This paper reviews the application of carbonation technology to the environmental industry as a way of reducing carbon dioxide (CO2, a green house gas, including the presentation of related projects of our research group. An alternative technology to very slow natural carbonation is the co-called ‘accelerated carbonation’, which completes its fast reaction within few hours by using pure CO2. Carbonation technology is widely applied to solidify or stabilize solid combustion residues from municipal solid wastes, paper mill wastes, etc. and contaminated soils, and to manufacture precipitated calcium carbonate (PCC. Carbonated products can be utilized as aggregates in the concrete industry and as alkaline fillers in the paper (or recycled paper making industry. The quantity of captured CO2 in carbonated products can be evaluated by measuring mass loss of heated samples by thermo-gravimetric (TG analysis. The industrial carbonation technology could contribute to both reduction of CO2 emissions and environmental remediation.

  20. The production of carbon nanotubes from carbon dioxide: challenges and opportunities

    Institute of Scientific and Technical Information of China (English)

    Geoffrey S. Simate; Sunny E. Iyuke; Sehliselo Ndlovu; Clarence S. Yah; Lubinda F. Walubita

    2010-01-01

    Recent advances in the production of carbon nanotubes (CNTs) are reviewed with an emphasis on the use of carbon dioxide (CO2) as a sole source of carbon. Compared to the most widely used carbon precursors such as graphite, methane, acetylene, ethanol, ethylene,and coal-derived hydrocarbons, CO2 is competitively cheaper with relatively high carbon yield content. However, CNT synthesis from CO2 is a newly emerging technology, and hence it needs to be explored further. A theoretical and analytical comparison of the currently existing CNT-CO2 synthesis techniques is given including a review of some of the process parameters (i.e., temperature, pressure, catalyst, etc.) that affect the CO2 reduction rate. Such analysis indicates that there is still a fundamental need to further explore the following aspects so as to realize the full potential of CO2 based CNT technology: (1) the CNT-CO2 synthesis and formation mechanism,(2) catalytic effects of transitional metals and mechanisms, (3) utilization of metallocenes in the CNT-CO2 reactions, (4) applicability of ferrite-organometallic compounds in the CNT-CO2 synthesis reactions, and (5) the effects of process parameters such as temperature,etc.

  1. A new technology for production of high thickness carbon/carbon composites for launchers application

    Science.gov (United States)

    Albano, Marta; Delfini, Andrea; Pastore, Roberto; Micheli, Davide; Marchetti, Mario

    2016-11-01

    Carbon-Carbon (C/C) composites are known for their extraordinary stability and excellent mechanical properties, almost unchanged at high temperatures. Among the several advanced applications, C/C based materials can be used in engines as nozzle throat section for launchers. In particular, the main feature for such employment is the material high resistance in extreme thermal environment. On the other hand, large-size items are required for this kind of purposes, thus introducing criticalities in terms of material uniformity and final overall properties. Up to now, there no standard for the production of high thickness C/C structures. In this paper a novel manufacturing method is analyzed, following each phase of the process, from the carbon fiber preform design and preparation to the carbon densification by chemical vapor infiltration method. Five preforms of large dimensions with different characteristics have been manufactured and infiltrated. The realized prototypes have been then analyzed by means of mechanical, physical and morphological tests. Aim of the results of this preliminary work is to establish a set of guidelines for a well-defined high thickness C/C production method.

  2. Replica inference approach to unsupervised multiscale image segmentation.

    Science.gov (United States)

    Hu, Dandan; Ronhovde, Peter; Nussinov, Zohar

    2012-01-01

    We apply a replica-inference-based Potts model method to unsupervised image segmentation on multiple scales. This approach was inspired by the statistical mechanics problem of "community detection" and its phase diagram. Specifically, the problem is cast as identifying tightly bound clusters ("communities" or "solutes") against a background or "solvent." Within our multiresolution approach, we compute information-theory-based correlations among multiple solutions ("replicas") of the same graph over a range of resolutions. Significant multiresolution structures are identified by replica correlations manifest by information theory overlaps. We further employ such information theory measures (such as normalized mutual information and variation of information), thermodynamic quantities such as the system entropy and energy, and dynamic measures monitoring the convergence time to viable solutions as metrics for transitions between various solvable and unsolvable phases. Within the solvable phase, transitions between contending solutions (such as those corresponding to segmentations on different scales) may also appear. With the aid of these correlations as well as thermodynamic measures, the phase diagram of the corresponding Potts model is analyzed at both zero and finite temperatures. Optimal parameters corresponding to a sensible unsupervised segmentations appear within the "easy phase" of the Potts model. Our algorithm is fast and shown to be at least as accurate as the best algorithms to date and to be especially suited to the detection of camouflaged images.

  3. An Update on Natural Products with Carbonic Anhydrase Inhibitory Activity.

    Science.gov (United States)

    Karioti, Anastasia; Carta, Fabrizio; Supuran, Claudiu T

    2016-01-01

    Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the fundamental reaction of CO2 hydration in all living organisms, being actively involved in the regulation of a plethora of patho/physiological processes. They represent a typical example of enzyme convergent evolution, as six genetically unrelated families of such enzymes were described so far. It is more than 70 years that synthetic compounds, mainly sulfonamides, have been used in clinical practice as diuretics and systemic acting antiglaucoma drugs. Recent studies using natural product libraries and isolated constituents from natural sources (such as fungi and plants) have disclosed novel chemotypes possessing carbonic anhydrase inhibition activities. These natural sources offer new opportunities in the search for new and more effective carbonic anhydrase inhibitors, and may serve as new leads for the design and development of future drugs. This review will discuss the most recent advances in the search of naturally occurring products and their synthetic derivatives that inhibit the CAs and their mechanisms of action at molecular level. Plant extracts are not considered in the present review.

  4. Solar production of catalytic filamentous carbon by thermal decomposition of hydrocarbons and carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, V.A.; Kuvshinov, G.G.; Mogilnykh, Yu.I. [Boreskov Institute of Catalysis, Novosibirsk (Russian Federation); Reller, A. [University of Hamburg (Germany); Steinfeld, A.; Weidenkaff, A.; Meier, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Concentrated solar radiation was used as the clean source of process heat for the production of Catalytic Filamentous Carbon (CFC) by thermal decomposition of gaseous hydrocarbons and by CO disproportionation in the presence of small metal catalyst particles. Depending on the catalyst, two different types of CFC, namely nano tubes and nano fibers, were obtained in solar experiments at the PSI solar furnace. (author) 2 figs., 1 tab., 7 refs.

  5. Production of carbon molecular sieves from illinois coals. An assessment

    Science.gov (United States)

    Lizzio, Anthony A.; Rostam-Abadi, Massoud

    1991-01-01

    Chars were produced from an Illinois No. 2 bituminous coal under various pyrolysis and activation conditions and tested for their molecular sieve properties. The amount of N2 compared to the amount of CO2 adsorbed by each char was used as a preliminary indicator of its molecular sieve properties. This relatively simple, but apparently useful test was confirmed by successfully characterizing the well-known molecular sieve properties of a commercial zeolite and molecular sieve carbon. In addition, coal chars having relatively high surface areas (800-1800 m2/g) were produced and tested for their molecular sieving capabilities. These carbon materials, which have high adsorption capacities and relatively narrow pore size distributions, should be ideal candidates for the commercial production of CMS.

  6. Facile preparation of hierarchically porous carbon using diatomite as both template and catalyst and methylene blue adsorption of carbon products.

    Science.gov (United States)

    Liu, Dong; Yuan, Peng; Tan, Daoyong; Liu, Hongmei; Wang, Tong; Fan, Mingde; Zhu, Jianxi; He, Hongping

    2012-12-15

    Hierarchically porous carbons were prepared using a facile preparation method in which diatomite was utilized as both template and catalyst. The porous structures of the carbon products and their formation mechanisms were investigated. The macroporosity and microporosity of the diatomite-templated carbons were derived from replication of diatom shell and structure-reconfiguration of the carbon film, respectively. The macroporosity of carbons was strongly dependent on the original morphology of the diatomite template. The macroporous structure composed of carbon plates connected by the pillar- and tube-like macropores resulted from the replication of the central and edge pores of the diatom shells with disk-shaped morphology, respectively. And another macroporous carbon tubes were also replicated from canoe-shaped diatom shells. The acidity of diatomite dramatically affected the porosity of the carbons, more acid sites of diatomite template resulted in higher surface area and pore volume of the carbon products. The diatomite-templated carbons exhibited higher adsorption capacity for methylene blue than the commercial activated carbon (CAC), although the specific surface area was much smaller than that of CAC, due to the hierarchical porosity of diatomite-templated carbons. And the carbons were readily reclaimed and regenerated. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Calcium carbonate production response to future ocean warming and acidification

    Directory of Open Access Journals (Sweden)

    A. J. Pinsonneault

    2012-06-01

    Full Text Available Anthropogenic carbon dioxide (CO2 emissions are acidifying the ocean, affecting calcification rates in pelagic organisms, and thereby modifying the oceanic carbon and alkalinity cycles. However, the responses of pelagic calcifying organisms to acidification vary widely between species, contributing uncertainty to predictions of atmospheric CO2 and the resulting climate change. At the same time, ocean warming caused by rising CO2 is expected to drive increased growth rates of all pelagic organisms, including calcifiers. It thus remains unclear whether anthropogenic CO2 emissions will ultimately increase or decrease pelagic calcification rates. Here, we assess the importance of this uncertainty by introducing a dependence of calcium carbonate (CaCO3 production on calcite saturation state (ΩCaCO3 in an intermediate complexity coupled carbon-climate model. In a series of model simulations, we examine the impact of several variants of this dependence on global ocean carbon cycling between 1800 and 3500 under two different CO2 emissions scenarios. Introducing a calcification-saturation state dependence has a significant effect on the vertical and surface horizontal alkalinity gradients, as well as on the removal of alkalinity from the ocean through CaCO3 burial. These changes result in an additional oceanic uptake of carbon when calcification depends on ΩCaCO3 (of up to 270 Pg C, compared to the case where calcification does not depend on acidification. In turn, this response causes a reduction of global surface air temperature of up to 0.4 °C in year 3500. Different versions of the model produced varying results, and narrowing this range of uncertainty will require better understanding of both temperature and acidification effects on pelagic calcifiers. Nevertheless, our results suggest that alkalinity observations can be used

  8. Calcium carbonate production response to future ocean warming and acidification

    Directory of Open Access Journals (Sweden)

    A. J. Pinsonneault

    2011-12-01

    Full Text Available Anthropogenic carbon dioxide (CO2 emissions are acidifying the ocean, affecting calcification rates in pelagic organisms and thereby modifying the oceanic alkalinity cycle. However, the responses of pelagic calcifying organisms to acidification vary widely between species, contributing uncertainty to predictions of atmospheric CO2 and the resulting climate change. Meanwhile, ocean warming caused by rising CO2 is expected to drive increased growth rates of all pelagic organisms, including calcifiers. It thus remains unclear whether anthropogenic CO2 will ultimately increase or decrease the globally-integrated pelagic calcification rate. Here, we assess the importance of this uncertainty by introducing a variable dependence of calcium carbonate (CaCO3 production on calcite saturation state (ΩCaCO3 in the University of Victoria Earth System Climate Model, an intermediate complexity coupled carbon-climate model. In a series of model simulations, we examine the impact of this parameterization on global ocean carbon cycling under two CO2 emissions scenarios, both integrated to the year 3500. The simulations show a significant sensitivity of the vertical and surface horizontal alkalinity gradients to the parameterization, as well as the removal of alkalinity from the ocean through CaCO3 burial. These sensitivities result in an additional oceanic uptake of carbon when calcification depends on ΩCaCO3 (of up to 13 % of total carbon emissions, compared to the case where calcification is insensitive to acidification. In turn, this response causes a reduction of global surface air temperature of up to 0.4 °C in year 3500, a 13 % reduction in the amplitude of warming. Narrowing these uncertainties will require better understanding of both temperature and acidification effects on pelagic calcifiers. Preliminary examination suggests that

  9. Connexin composition in apposed gap junction hemiplaques revealed by matched double-replica freeze-fracture replica immunogold labeling.

    Science.gov (United States)

    Rash, John E; Kamasawa, Naomi; Davidson, Kimberly G V; Yasumura, Thomas; Pereda, Alberto E; Nagy, James I

    2012-06-01

    Despite the combination of light-microscopic immunocytochemistry, histochemical mRNA detection techniques and protein reporter systems, progress in identifying the protein composition of neuronal versus glial gap junctions, determination of the differential localization of their constituent connexin proteins in two apposing membranes and understanding human neurological diseases caused by connexin mutations has been problematic due to ambiguities introduced in the cellular and subcellular assignment of connexins. Misassignments occurred primarily because membranes and their constituent proteins are below the limit of resolution of light microscopic imaging techniques. Currently, only serial thin-section transmission electron microscopy and freeze-fracture replica immunogold labeling have sufficient resolution to assign connexin proteins to either or both sides of gap junction plaques. However, freeze-fracture replica immunogold labeling has been limited because conventional freeze fracturing allows retrieval of only one of the two membrane fracture faces within a gap junction, making it difficult to identify connexin coupling partners in hemiplaques removed by fracturing. We now summarize progress in ascertaining the connexin composition of two coupled hemiplaques using matched double-replicas that are labeled simultaneously for multiple connexins. This approach allows unambiguous identification of connexins and determination of the membrane "sidedness" and the identities of connexin coupling partners in homotypic and heterotypic gap junctions of vertebrate neurons.

  10. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Quentin C. Berg; Stephen P. Carpenter; Dady Dadyburjor; Jason C. Hissam; Manoj Katakdaunde; Liviu Magean; Abha Saddawi; Alfred H. Stiller; John W. Zondlo

    2006-03-07

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the development of carbon electrodes for Direct Carbon Fuel Cells (DCFC), and on carbon foam composites used in ballistic armor, as well as the hydrotreatment of solvents used in the basic solvent extraction process. A major goal is the production of 1500 pounds of binder pitch, corresponding to about 3000 pounds of hydrotreated solvent.

  11. Operation Mechanism of Farmers’ Professional Cooperatives from the Point of Low-Carbon Agricultural Products

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    We firstly take a look at internal logic of cluster development of low-carbon agricultural products.In combination with operation features of farmers’ professional cooperatives and actual requirements for cluster development of low-carbon agricultural products;we elaborate establishing benefit allocation mechanism,bearing education and training functions,forming low-carbon value,building low-carbon identification system,as well as realizing low-carbon value.According to these situations,we systematically analyze operation mechanism of farmers’ professional cooperatives suitable for cluster development of low-carbon agricultural products.To promote cluster development of low-carbon agricultural products,we put forward following suggestions,including government guidance and encouragement,social acceptance and active cooperation,and integration into global low-carbon development system to share benefit of low-carbon development.

  12. Phase heterogeneity in carbonate production by marine fish influences their roles in sediment generation and the inorganic carbon cycle.

    Science.gov (United States)

    Salter, Michael A; Harborne, Alastair R; Perry, Chris T; Wilson, Rod W

    2017-04-10

    Marine teleost fish are important carbonate producers in neritic and oceanic settings. However, the fates of the diverse carbonate phases (i.e., mineral and amorphous forms of CaCO3) they produce, and their roles in sediment production and marine inorganic carbon cycling, remain poorly understood. Here we quantify the carbonate phases produced by 22 Bahamian fish species and integrate these data with regional fish biomass data from The Bahamas to generate a novel platform-scale production model that resolves these phases. Overall carbonate phase proportions, ordered by decreasing phase stability, are: ~20% calcite, ~6% aragonite, ~60% high-Mg calcite, and ~14% amorphous carbonate. We predict that these phases undergo differing fates, with at least ~14% (amorphous carbonate) likely dissolving rapidly. Results further indicate that fisheries exploitation in The Bahamas has potentially reduced fish carbonate production by up to 58% in certain habitats, whilst also driving a deviation from natural phase proportions. These findings have evident implications for understanding sedimentary processes in shallow warm-water carbonate provinces. We further speculate that marked phase heterogeneity may be a hitherto unrecognised feature of fish carbonates across a wide range of neritic and oceanic settings, with potentially major implications for understanding their role in global marine inorganic carbon cycling.

  13. Production of carbon molecular sieves from palm shell through carbon deposition from methane

    Directory of Open Access Journals (Sweden)

    Mohammadi Maedeh

    2011-01-01

    Full Text Available The possibility of production of carbon molecular sieve (CMS from palm shell as a waste lignocellulosic biomass was investigated. CMS samples were prepared through heat treatment processes including carbonization, physiochemical activation and chemical vapor deposition (CVD from methane. Methane was pyrolyzed to deposit fine carbon on the pore mouth of palm shell-based activated carbon to yield CMS. All the deposition experiments were performed at 800 ºC, while the methane flow rate (100, 200, 300 mL min-1 CH4 diluted in 500 mL min-1 N2 and deposition time (30 to 60 min were the investigated parameters. The textural characteristics of the CMSs were assessed by N2 adsorption. The largest BET surface area (752 m2 g-1, micropore surface area (902.2 m2 g-1 and micropore volume (0.3466 cm3 g-1 was obtained at the CH4 flow rate of 200 mL min-1 and deposition time of 30 min. However, prolonging the deposition time to 45 min yielded in a micropouros CMS with a narrow pore size distribution.

  14. High surface area carbon and process for its production

    Science.gov (United States)

    Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

    2016-12-13

    Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

  15. Life Cycle Analysis of Carbon Flow and Carbon Footprint of Harvested Wood Products of Larix principis-rupprechtii in China

    Directory of Open Access Journals (Sweden)

    Fei Lun

    2016-03-01

    Full Text Available Larix principis-rupprechtii is a native tree species in North China with a large distribution; and its harvested timbers can be used for producing wood products. This study focused on estimating and comparing carbon flows and carbon footprints of different harvested wood products (HWPs from Larix principis-ruppechtii based on the life cycle analysis (from seedling cultivation to HWP final disposal. Based on our interviews and surveys, the system boundary in this study was divided into three processes: the forestry process, the manufacturing process, and the use and disposal process. By tracking carbon flows of HWPs along the entire life cycle, we found that, for one forest rotation period, a total of 26.81 tC/ha sequestered carbon was transferred into these HWPs, 66.2% of which were still stored in the HWP when the rotation period had ended; however, the HWP carbon storage decreased to 0.25 tC/ha (only 0.9% left in the 100th year after forest plantation. The manufacturing process contributed more than 90% of the total HWP carbon footprint, but it was still smaller than the HWP carbon storage. In terms of the carbon storage and the carbon footprint, construction products had the largest net positive carbon balance compared to furniture and panel products. In addition, HWP are known to have a positive impact on global carbon mitigation because they can store parts of the sequestered carbon for a certain period of time and they have a substitution effect on carbon mitigation. Furthermore, there still exist great opportunities for carbon mitigation from HWPs through the use of cleaner energy and increasing the utilization efficiency of wood fuel.

  16. One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production

    Energy Technology Data Exchange (ETDEWEB)

    Zeikus, J.G.; Jain, M.

    1993-12-31

    The project deals with understanding the fundamental biochemical mechanisms that physiologically control and regulate carbon and electron flow in anaerobic chemosynthetic bacteria that couple metabolism of single carbon compounds and hydrogen to the production of organic acids (formic, acetic, butyric, and succinic) or methane. The authors compare the regulation of carbon dioxide and hydrogen metabolism by fermentation, enzyme, and electron carrier analysis using Butyribacterium methylotrophicum, Anaeroblospirillum succiniciproducens, Methanosarcina barkeri, and a newly isolated tri-culture composed of a syntrophic butyrate degrader strain IB, Methanosarcina mazei and Methanobacterium formicicum as model systems. To understand the regulation of hydrogen metabolism during butyrate production or acetate degradation, hydrogenase activity in B. methylotrophicum or M. barkeri is measured in relation to growth substrate and pH; hydrogenase is purified and characterized to investigate number of hydrogenases; their localization and functions; and, their sequences are determined. To understand the mechanism for catabolic CO{sub 2} fixation to succinate the PEP carboxykinase enzyme and gene of A. succiniciproducens are purified and characterized. Genetically engineered strains of Escherichia coli containing the phosphoenolpyruvate (PEP) carboxykinase gene are examined for their ability to produce succinate in high yield. To understand the mechanism of fatty acid degradation by syntrophic acetogens during mixed culture methanogenesis formate and hydrogen production are characterized by radio tracer studies. It is intended that these studies provide strategies to improve anaerobic fermentations used for the production of organic acids or methane and, new basic understanding on catabolic CO{sub 2} fixation mechanisms and on the function of hydrogenase in anaerobic bacteria.

  17. Production of carbon molecular sieves from Illinois coal

    Science.gov (United States)

    Lizzio, A.A.; Rostam-Abadi, M.

    1993-01-01

    Carbon molecular sieves (CMS) have become an increasingly important class of adsorbents for application in the separation of gas molecules that vary in size and shape. A study is in progress at the Illinois State Geological Survey to determine whether Illinois basin coals are suitable feedstocks for the production of CMS and to evaluate their potential application in gas separation processes of commercial importance. Chars were prepared from Illinois coal in a fixed-bed reactor under a wide range of heat treatment and activation conditions. The effects of various coal/char pretreatments, including coal demineralization, preoxidation, char activation, and carbon deposition, on the molecular sieve properties of the chars were also investigated. Chars with commercially significant BET surface areas of 1500 m2/g were produced by chemical activation using potassium hydroxide as the activant. These high-surface-area (HSA) chars had more than twice the adsorption capacity of commercial carbon and zeolite molecular sieves. The kinetics of adsorption of various gases, e.g., N2, O2, CO2, CH4, CO and H2, on these chars at 25??C was measured. The O2/N2 molecular sieve properties of one char prepared without chemical activation were similar to those of a commercial CMS. On the other hand, the O2/N2 selectivity of the HSA char was comparable to that of a commercial activated carbon, i.e., essentially unity. Carbon deposition, using methane as the cracking gas, increased the O2/N2 selectivity of the HSA char, but significantly decreased its adsorption capacity. Several chars showed good potential for efficient CO2/CH4 separation; both a relatively high CO2 adsorption capacity and CO2/CH4 selectivity were achieved. The micropore size distribution of selected chars was estimated by equilibrium adsorption of carbon dioxide, n-butane and iso-butane at O??C. The extent of adsorption of each gas corresponded to the effective surface area contained in pores with diameters greater than 3

  18. DEVELOPMENT OF CARBON PRODUCTS FROM LOW-RANK COALS

    Energy Technology Data Exchange (ETDEWEB)

    Edwin S. Olson

    2001-07-01

    The goal of this project is to facilitate the production of carbon fibers from low-rank coal (LRC) tars. To this end, the effect of demineralization on the tar yields and composition was investigated using high-sodium and high-calcium lignites commonly mined in North Dakota. These coals were demineralized by ion exchange with ammonium acetate and by cation dissolution with nitric acid. Two types of thermal processing were investigated for obtaining suitable precursors for pitch and fiber production. Initially, tars were produced by simple pyrolysis of the set of samples at 650 C. Since these experiments produced little usable material from any of the samples, the coals were heated at moderate temperatures (380 and 400 C) in tetralin solvent to form and extract the plastic material (metaplast) that forms at these temperatures.

  19. Catalytic carbon membranes for hydrogen production. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Damle, A.S.; Gangwal, S.K.

    1992-01-01

    Commercial carbon composite microfiltration membranes may be modified for gas separation applications by providing a gas separation layer with pores in the 1- to 10-nm range. Several organic polymeric precursors and techniques for depositing a suitable layer were investigated in this project. The in situ polymerization technique was found to be the most promising, and pure component permeation tests with membrane samples prepared with this technique indicated Knudsen diffusion behavior. The gas separation factors obtained by mixed-gas permeation tests were found to depend strongly on gas temperature and pressure indicating significant viscous flow at high-pressure conditions. The modified membranes were used to carry out simultaneous water gas shift reaction and product hydrogen separation. These tests indicated increasing CO conversions with increasing hydrogen separation. A simple process model was developed to simulate a catalytic membrane reactor. A number of simulations were carried out to identify operating conditions leading to product hydrogen concentrations over 90 percent. (VC)

  20. Sustainable production of green feed from carbon dioxide and hydrogen.

    Science.gov (United States)

    Landau, Miron V; Vidruk, Roxana; Herskowitz, Moti

    2014-03-01

    Carbon dioxide hydrogenation to form hydrocarbons was conducted on two iron-based catalysts, prepared according to procedures described in the literature, and on a new iron spinel catalyst. The CO2 conversion measured in a packed-bed reactor was limited to about 60% because of excessive amounts of water produced in this process. Switching to a system of three packed-bed reactors in series with interim removal of water and condensed hydrocarbons increased CO2 conversion to as much as 89%. The pure spinel catalyst displayed a significantly higher activity and selectivity than those of the other iron catalysts. This process produces a product called green feed, which is similar in composition to the product of a high-temperature, iron-based Fischer–Tropsch process from syngas. The green feed can be readily converted into renewable fuels by well-established technologies.

  1. Spatial Estimation of Timber Production and Carbon in Harvested Wood Products Using Remote Sensing

    Science.gov (United States)

    Ling, P. Y.; Baiocchi, G.; Huang, C.

    2014-12-01

    Accurate estimation of the annual production of different kinds of timbers at different locations has many science and policy implications. For example, timber type information is needed for accurate estimation of the amount and life cycle of carbon stored in the harvested wood product (HWP) pool, and possible transport of carbon in wood products through trade. Several attempts have been made to estimate the carbon storage in the HWP, regardless which approach to use, information of the annual timber production are required. A statistic model has been developed to estimate the annual roundwood production at the county level. The inputs of the model includes forest disturbance area calculated using the VCT algorithm derived from the Landsat time series stack, a forest type map, and timber product output (TPO) data collected from wood processing mills by the USFS. The model is applied to North Carolina, a state with a large forestry sector and where harvesting and logging are a primary forest disturbance type. Ten-fold cross validation were done to the preliminary estimation for each type of HWP. The root mean square errors range between 13.6 and 31.5 for hardwood types; and between 1.3 and 55.6 for softwood types. The model is empirical as it depends on the local information on forest disturbance, forest types, and the amount of the roundwood output. However, the approach of the model can be used to apply to other areas with the local information provided. The result can be served as a starting point in spatial estimation of carbon storage in HWP.

  2. Photorespiration and carbon limitation determine productivity in temperate seagrasses.

    Directory of Open Access Journals (Sweden)

    Pimchanok Buapet

    Full Text Available The gross primary productivity of two seagrasses, Zostera marina and Ruppia maritima, and one green macroalga, Ulva intestinalis, was assessed in laboratory and field experiments to determine whether the photorespiratory pathway operates at a substantial level in these macrophytes and to what extent it is enhanced by naturally occurring shifts in dissolved inorganic carbon (DIC and O2 in dense vegetation. To achieve these conditions in laboratory experiments, seawater was incubated with U. intestinalis in light to obtain a range of higher pH and O2 levels and lower DIC levels. Gross photosynthetic O2 evolution was then measured in this pretreated seawater (pH, 7.8-9.8; high to low DIC:O2 ratio at both natural and low O2 concentrations (adjusted by N2 bubbling. The presence of photorespiration was indicated by a lower gross O2 evolution rate under natural O2 conditions than when O2 was reduced. In all three macrophytes, gross photosynthetic rates were negatively affected by higher pH and lower DIC. However, while both seagrasses exhibited significant photorespiratory activity at increasing pH values, the macroalga U. intestinalis exhibited no such activity. Rates of seagrass photosynthesis were then assessed in seawater collected from the natural habitats (i.e., shallow bays characterized by high macrophyte cover and by low DIC and high pH during daytime and compared with open baymouth water conditions (where seawater DIC is in equilibrium with air, normal DIC, and pH. The gross photosynthetic rates of both seagrasses were significantly higher when incubated in the baymouth water, indicating that these grasses can be significantly carbon limited in shallow bays. Photorespiration was also detected in both seagrasses under shallow bay water conditions. Our findings indicate that natural carbon limitations caused by high community photosynthesis can enhance photorespiration and cause a significant decline in seagrass primary production in shallow

  3. Photorespiration and carbon limitation determine productivity in temperate seagrasses.

    Science.gov (United States)

    Buapet, Pimchanok; Rasmusson, Lina M; Gullström, Martin; Björk, Mats

    2013-01-01

    The gross primary productivity of two seagrasses, Zostera marina and Ruppia maritima, and one green macroalga, Ulva intestinalis, was assessed in laboratory and field experiments to determine whether the photorespiratory pathway operates at a substantial level in these macrophytes and to what extent it is enhanced by naturally occurring shifts in dissolved inorganic carbon (DIC) and O2 in dense vegetation. To achieve these conditions in laboratory experiments, seawater was incubated with U. intestinalis in light to obtain a range of higher pH and O2 levels and lower DIC levels. Gross photosynthetic O2 evolution was then measured in this pretreated seawater (pH, 7.8-9.8; high to low DIC:O2 ratio) at both natural and low O2 concentrations (adjusted by N2 bubbling). The presence of photorespiration was indicated by a lower gross O2 evolution rate under natural O2 conditions than when O2 was reduced. In all three macrophytes, gross photosynthetic rates were negatively affected by higher pH and lower DIC. However, while both seagrasses exhibited significant photorespiratory activity at increasing pH values, the macroalga U. intestinalis exhibited no such activity. Rates of seagrass photosynthesis were then assessed in seawater collected from the natural habitats (i.e., shallow bays characterized by high macrophyte cover and by low DIC and high pH during daytime) and compared with open baymouth water conditions (where seawater DIC is in equilibrium with air, normal DIC, and pH). The gross photosynthetic rates of both seagrasses were significantly higher when incubated in the baymouth water, indicating that these grasses can be significantly carbon limited in shallow bays. Photorespiration was also detected in both seagrasses under shallow bay water conditions. Our findings indicate that natural carbon limitations caused by high community photosynthesis can enhance photorespiration and cause a significant decline in seagrass primary production in shallow waters.

  4. Burners and combustion apparatus for carbon nanomaterial production

    Science.gov (United States)

    Alford, J. Michael; Diener, Michael D.; Nabity, James; Karpuk, Michael

    2007-10-09

    The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

  5. Biomimetic zinc oxide replica with structural color using butterfly (Ideopsis similis) wings as templates.

    Science.gov (United States)

    Zhang, Wang; Zhang, Di; Fan, Tongxiang; Ding, Jian; Gu, Jiajun; Guo, Qixin; Ogawa, Hiroshi

    2006-09-01

    Nano-structured colorful zinc oxide (ZnO) replicas were produced using the wings of the Ideopsis similis butterfly as templates. The ZnO replicas we obtained exhibit iridescence, which was clearly observed under an optical microscope (OM). Field emission scanning electron microscope analysis shows that all the microstructure details are maintained faithfully in the ZnO replica. A computer model was established to simulate the diffraction spectral results, which agreed well with the OM images.

  6. Managing Commercial Tree Species for Timber Production and Carbon Sequestration: Management Guidelines and Financial Returns

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Kronrad

    2006-09-19

    A carbon credit market is developing in the United States. Information is needed by buyers and sellers of carbon credits so that the market functions equitably and efficiently. Analyses have been conducted to determine the optimal forest management regime to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. Because the potential of a forest ecosystem to sequester carbon depends on the tree species, site quality and management regimes utilized, analyses have determined how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities, discount rates, prices of carbon credits and other economic variables. The effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, the amount of carbon that can be sequestered, and the amount of timber products produced has been determined.

  7. Carbon footprint of Canadian dairy products: calculations and issues.

    Science.gov (United States)

    Vergé, X P C; Maxime, D; Dyer, J A; Desjardins, R L; Arcand, Y; Vanderzaag, A

    2013-09-01

    The Canadian dairy sector is a major industry with about 1 million cows. This industry emits about 20% of the total greenhouse gas (GHG) emissions from the main livestock sectors (beef, dairy, swine, and poultry). In 2006, the Canadian dairy herd produced about 7.7 Mt of raw milk, resulting in about 4.4 Mt of dairy products (notably 64% fluid milk and 12% cheese). An integrated cradle-to-gate model (field to processing plant) has been developed to estimate the carbon footprint (CF) of 11 Canadian dairy products. The on-farm part of the model is the Unified Livestock Industry and Crop Emissions Estimation System (ULICEES). It considers all GHG emissions associated with livestock production but, for this study, it was run for the dairy sector specifically. Off-farm GHG emissions were estimated using the Canadian Food Carbon Footprint calculator, (cafoo)(2)-milk. It considers GHG emissions from the farm gate to the exit gate of the processing plants. The CF of the raw milk has been found lower in western provinces [0.93 kg of CO2 equivalents (CO2e)/L of milk] than in eastern provinces (1.12 kg of CO2e/L of milk) because of differences in climate conditions and dairy herd management. Most of the CF estimates of dairy products ranged between 1 and 3 kg of CO2e/kg of product. Three products were, however, significantly higher: cheese (5.3 kg of CO2e/kg), butter (7.3 kg of CO2e/kg), and milk powder (10.1 kg of CO2e/kg). The CF results depend on the milk volume needed, the co-product allocation process (based on milk solids content), and the amount of energy used to manufacture each product. The GHG emissions per kilogram of protein ranged from 13 to 40 kg of CO2e. Two products had higher values: cream and sour cream, at 83 and 78 kg of CO2e/kg, respectively. Finally, the highest CF value was for butter, at about 730 kg of CO2e/kg. This extremely high value is due to the fact that the intensity indicator per kilogram of product is high and that butter is almost exclusively

  8. Method of carbon dioxide-free hydrogen production from hydrocarbon decomposition over metal salts

    Energy Technology Data Exchange (ETDEWEB)

    Erlebacher, Jonah; Gaskey, Bernard

    2017-10-03

    A process to decompose methane into carbon (graphitic powder) and hydrogen (H.sub.2 gas) without secondary production of carbon dioxide, employing a cycle in which a secondary chemical is recycled and reused, is disclosed.

  9. Replica location mechanism in data grid based on ED-Chord

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A peer-to-peer hierarchical replica location mechanism(PRLM)was designed for data grids to provide better load balancing capability and scalability.Global replica indexes of the PRLM are organized based on even distributed Chord(ED-Chord)structure.The locality can optimize queries on local replica indexes of virtual organizations.ED-Chord protocol collects the node identifiers information using a distributed method and assigns optimal identifiers for new nodes to make them more uniformly distributed in the entire identifier space.Theoretical analysis and simulations show that PRLM provides good performance,scalability and load balancing capability for replica location in data grids.

  10. Replica Analysis for Portfolio Optimization with Single-Factor Model

    Science.gov (United States)

    Shinzato, Takashi

    2017-06-01

    In this paper, we use replica analysis to investigate the influence of correlation among the return rates of assets on the solution of the portfolio optimization problem. We consider the behavior of an optimal solution for the case where the return rate is described with a single-factor model and compare the findings obtained from our proposed methods with correlated return rates with those obtained with independent return rates. We then analytically assess the increase in the investment risk when correlation is included. Furthermore, we also compare our approach with analytical procedures for minimizing the investment risk from operations research.

  11. REPLICA ORNSTEIN-ZERNIKE EQUATIONS FOR POSITIONALLY FROZEN HEISENBERG SYSTEMS

    Directory of Open Access Journals (Sweden)

    E.Lomba

    2003-01-01

    Full Text Available We present the formulation of the Replica Ornstein-Zernike equations for a model of positionally frozen disordered Heisenberg spin system. The results are obtained for various models, one in which the particle positions correspond to a frozen hard sphere fluid, another system in which the configurations are generated by a random insertion of hard spheres, a system of randomly distributed spins, and finally a system corresponding to a soft sphere fluid quenched at high and low temperatures. We will see that the orientational structure of the spin system is fairly well reproduced by the integral equation which, however, does not correctly account for the critical behaviour.

  12. Advances in Production and Applications of Carbon Nanotubes.

    Science.gov (United States)

    Jia, Xilai; Wei, Fei

    2017-02-01

    Recent decades have witnessed many breakthroughs in research on carbon nanotubes (CNTs), particularly regarding controllable synthesis, production scale-up, and application advances for this material. This sp (2)-bonded nanocarbon uniquely combines extreme mechanical strength, exceptionally high electrical conductivity, as well as many other superior properties, making it highly attractive for fundamental research and industrial applications. Synthesis and mass production form the solid basis for high-volume applications of CNTs. During recent decades, CNT production capacity has reached more than thousands of tons per year, greatly decreasing the price of CNTs. Although the unique physiochemical properties of an individual CNT are stated repeatedly, manifestation of such unique properties in a macroscopic material, e.g., realization of high-strength CNT fibers, remains a great challenge. If such challenges are solved, many critical applications will be enabled. Herein we review the critical progress in the development of synthesis and scaled-up production methods for CNTs, and discuss advances in their applications. Scientific problems and technological challenges are discussed together.

  13. Produção de interleucina-10 na gestação reduz a taxa de replicação do HIV-1 em culturas de linfócitos maternos Interleukin-10 production during pregnancy reduces HIV-1 replicaction in cultures of maternal lymphocytes

    Directory of Open Access Journals (Sweden)

    Bruno Monção Paolino

    2005-07-01

    Full Text Available OBJETIVO: avaliar a proliferação de células T e a produção de citocinas em gestantes infectadas pelo HIV-1 e seu impacto na replicação viral in vitro. MÉTODOS: sangue periférico de 12 gestantes infectadas pelo HIV-1 e de seus neonatos, bem como de 10 gestantes HIV-1 negativas, foi colhido e a quantidade de linfócitos TCD4+ e TCD8+ periféricos foi avaliada por citometria de fluxo. Para obter plasma ou células mononucleares periféricas (PBMC, as amostras foram centrifugadas na ausência ou presença de um gradiente de Ficoll-Hypaque, respectivamente. As PBMC foram mantidas em cultura por sete dias na presença de fito-hemaglutinina mais IL-2 recombinante e a resposta linfoproliferativa de células T foi analisada pelo método de exclusão em azul de Trypan. Em alguns experimentos, as culturas foram mantidas na presença adicional de anticorpo anti-IL-10. Os plasmas e sobrenadantes das culturas de PBMC ativadas foram submetidos à análise da produção de citocinas, pelo método ELISA indireto, e a carga viral, detectada pelo RT-PCR. RESULTADOS: independente da carga viral plasmática, a resposta linfoproliferativa em culturas de células obtidas de gestantes infectadas pelo HIV foi inferior às amostras normais [4,2±0,37 vs 2,4±0,56 (x 10(6 células/mL; pPURPOSE: to evaluate T cell proliferation and cytokine production in HIV-1-infected pregnant women and their impact on in vitro virus replication. METHODS: peripheral blood from 12 HIV-1-infected pregnant women and from their neonates was collected. As control, 10 samples from non-infected pregnants were also colleted. The CD4+ and CD8+ T cell counts were assayed by flow cytometry. Peripheral blood mononuclear cells (PBMC and plasma were obtained by centrifugation with and without Ficoll-Hypaque gradient, respectively. The freshly purified PBMC were kept in cultures for seven days with PHA plus r-IL-2, and the lymphoproliferative response was assayed by Trypan blue dye exclusion

  14. Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum

    Energy Technology Data Exchange (ETDEWEB)

    Ho, C.S.; Smith, M.D.

    1986-01-01

    The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

  15. Diamond Opal-Replica Photonic Crystals and Graphitic Metallic Photonic Band Gap Structures: Fabrication and Properties

    Science.gov (United States)

    Zakhidov, A. A.; Baughman, R. H.; Iqbal, Z.; Khayrullin, I. I.; Ralchenko, V. G.

    1998-03-01

    We demonstrate a new method for the formation of photonic bandgap crystals that operate at optical wavelengths. This method involves the templating of a self-assempled SiO2 lattice with diamond, graphite, or amorphous forms of carbon, followed by the removal of the original SiO2 lattice matrix by chemical means. Such carbon opal replicas are the "air type" of photonic crystal (where air replaces silica spheres) that are most favourable for photonic bandgap formation. Surprisingly, the structure of the original opal lattice having a typical cubic lattice dimension of 250 nm) is reliably replicated down to the nanometer scale using either a diamond, graphite, or amorphous carbon templated material. The optical properties of these photonic bandgap crystals are reported and compared with both theory and experimental results on other types of opal-derived lattices that we have investigated. The graphitic reverse opal is the first example of a network type metallic photonic crystal for the optical domain, for which a large photonic bandgap have been predicted.

  16. Carbon dioxide production during cardiopulmonary bypass: pathophysiology, measure and clinical relevance.

    Science.gov (United States)

    Ranucci, Marco; Carboni, Giovanni; Cotza, Mauro; de Somer, Filip

    2017-01-01

    Carbon dioxide production during cardiopulmonary bypass derives from both the aerobic metabolism and the buffering of lactic acid produced by tissues under anaerobic conditions. Therefore, carbon dioxide removal monitoring is an important measure of the adequacy of perfusion and oxygen delivery. However, routine monitoring of carbon dioxide removal is not widely applied. The present article reviews the main physiological and pathophysiological sources of carbon dioxide, the available techniques to assess carbon dioxide production and removal and the clinically relevant applications of carbon dioxide-related variables as markers of the adequacy of perfusion during cardiopulmonary bypass.

  17. Production and detection of carbon dioxide on Iapetus

    Science.gov (United States)

    Palmer, Eric E.; Brown, Robert H.

    2011-04-01

    Cassini VIMS detected carbon dioxide on the surface of Iapetus during its insertion orbit. We evaluated the CO 2 distribution on Iapetus and determined that it is concentrated almost exclusively on Iapetus' dark material. VIMS spectra show a 4.27-μm feature with an absorption depth of 24%, which, if it were in the form of free ice, requires a layer 31 nm thick. Extrapolating for all dark material on Iapetus, the total observable CO 2 would be 2.3 × 10 8 kg. Previous studies note that free CO 2 is unstable at 10 AU over geologic timescales. Carbon dioxide could, however, be stable if trapped or complexed, such as in inclusions or clathrates. While complexed CO 2 has a lower thermal volatility, loss due to photodissociation by UV radiation and gravitational escape would occur at a rate of 2.6 × 10 7 kg year -1. Thus, Iapetus' entire inventory of surface CO 2 could be lost within a few decades. The high loss/destruction rate of CO 2 requires an active source. We conducted experiments that generated CO 2 by UV radiation of simulated icy regolith under Iapetus-like conditions. The simulated regolith was created by flash-freezing degassed water, crushing it into sub-millimeter sized particles, and then mixing it with isotopically labeled amorphous carbon ( 13C) dust. These samples were placed in a vacuum chamber and cooled to temperatures between 50 K and 160 K. The samples were irradiated with UV light, and the products were measured using a mass spectrometer, from which we measured 13CO 2 production at a rate of 2.0 × 10 12 mol s -1. Extrapolating to Iapetus and adjusting for the solar UV intensity and Iapetus' surface area, we calculated that CO 2 production for the entire surface would be 1.1 × 10 7 kg year -1, which is only a factor of two less than the loss rate. As such, UV photochemical generation of CO 2 is a plausible source of the detected CO 2.

  18. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2005-08-11

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the facility modifications for continuous hydrotreating, as well as developing improved protocols for producing synthetic pitches.

  19. RESEARCH ON CARBON PRODUCTS FROM COAL USING AN EXTRACTIVE PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo; Chong Chen; Brian Bland; David Fenton

    2002-03-31

    This report presents the results of a one-year effort directed at the exploration of the use of coal as a feedstock for a variety of industrially-relevant carbon products. The work was basically divided into three focus areas. The first area dealt with the acquisition of laboratory equipment to aid in the analysis and characterization of both the raw coal and the coal-derived feedstocks. Improvements were also made on the coal-extraction pilot plant which will now allow larger quantities of feedstock to be produced. Mass and energy balances were also performed on the pilot plant in an attempt to evaluate the scale-up potential of the process. The second focus area dealt with exploring hydrogenation conditions specifically aimed at testing several less-expensive candidate hydrogen-donor solvents. Through a process of filtration and vacuum distillation, viable pitch products were produced and evaluated. Moreover, a recycle solvent was also isolated so that the overall solvent balance in the system could be maintained. The effect of variables such as gas pressure and gas atmosphere were evaluated. The pitch product was analyzed and showed low ash content, reasonable yield, good coking value and a coke with anisotropic optical texture. A unique plot of coke yield vs. pitch softening point was discovered to be independent of reaction conditions or hydrogen-donor solvent. The third area of research centered on the investigation of alternate extraction solvents and processing conditions for the solvent extraction step. A wide variety of solvents, co-solvents and enhancement additives were tested with varying degrees of success. For the extraction of raw coal, the efficacy of the alternate solvents when compared to the benchmark solvent, N-methyl pyrrolidone, was not good. However when the same coal was partially hydrogenated prior to solvent extraction, all solvents showed excellent results even for extractions performed at room temperature. Standard analyses of the

  20. Replica approach to mean-variance portfolio optimization

    Science.gov (United States)

    Varga-Haszonits, Istvan; Caccioli, Fabio; Kondor, Imre

    2016-12-01

    We consider the problem of mean-variance portfolio optimization for a generic covariance matrix subject to the budget constraint and the constraint for the expected return, with the application of the replica method borrowed from the statistical physics of disordered systems. We find that the replica symmetry of the solution does not need to be assumed, but emerges as the unique solution of the optimization problem. We also check the stability of this solution and find that the eigenvalues of the Hessian are positive for r  =  N/T  portfolio and T the length of the time series used to estimate the covariance matrix. At the critical point r  =  1 a phase transition is taking place. The out of sample estimation error blows up at this point as 1/(1  -  r), independently of the covariance matrix or the expected return, displaying the universality not only of the critical exponent, but also the critical point. As a conspicuous illustration of the dangers of in-sample estimates, the optimal in-sample variance is found to vanish at the critical point inversely proportional to the divergent estimation error.

  1. Generating Scaled Replicas of Real-World Complex Networks

    CERN Document Server

    Staudt, Christian L; Safro, Ilya; Gutfraind, Alexander; Meyerhenke, Henning

    2016-01-01

    Research on generative models plays a central role in the emerging field of network science, studying how statistical patterns found in real networks can be generated by formal rules. During the last two decades, a variety of models has been proposed with an ultimate goal of achieving comprehensive realism for the generated networks. In this study, we (a) introduce a new generator, termed ReCoN; (b) explore how models can be fitted to an original network to produce a structurally similar replica, and (c) aim for producing much larger networks than the original exemplar. In a comparative experimental study, we find ReCoN often superior to many other state-of-the-art network generation methods. Our design yields a scalable and effective tool for replicating a given network while preserving important properties at both micro- and macroscopic scales and (optionally) scaling the replica by orders of magnitude in size. We recommend ReCoN as a general practical method for creating realistic test data for the enginee...

  2. High surface area carbon and process for its production

    Energy Technology Data Exchange (ETDEWEB)

    Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

    2016-12-13

    Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

  3. MEDIA OPTIMIZATION FOR BIOPROTEINS PRODUCTION FROM CHEAPER CARBON SOURCE

    Directory of Open Access Journals (Sweden)

    P. JAMAL

    2008-08-01

    Full Text Available There are high demands for animal and human food supply especially protein, which is an important dietary component. Agricultural wastes, cheap carbon sources- which are rich and have high energy, can be used for producing the value added bioprotein. A lab scale study was carried out to optimize the media composition for bioprotein production from a cheaper carbon source - wheat flour using potential strain, which was selected earlier by screening different microorganisms. The performance of the selected strain was enhanced by media optimization with varied substrate concentration, nitrogen sources and nutrient supplementation according to the central composite design from STATISTICA software. Statistical optimization was carried out to evaluate the polynomial regression model through effect of linear, quadratic and interaction of the factors. The maximum biomass produced was 21.89 g/L with optimum fermentation conditions of wheat flour (4 g/L, nitrogen concentration (0.5 g/L, nutrient concentration (0.1 g/L, and four days of fermentation.

  4. Electrochemical device for converting carbon dioxide to a reaction product

    Energy Technology Data Exchange (ETDEWEB)

    Masel, Richard I.; Chen, Qingmei; Liu, Zengcai; Kutz, Robert

    2016-11-01

    An electrochemical device converts carbon dioxide to a reaction product. The device includes an anode and a cathode, each comprising a quantity of catalyst. The anode and cathode each has reactant introduced thereto. A polymer electrolyte membrane is interposed between the anode and the cathode. At least a portion of the cathode catalyst is directly exposed to gaseous carbon dioxide during electrolysis. The average current density at the membrane is at least 20 mA/cm.sup.2, measured as the area of the cathode gas diffusion layer that is covered by catalyst, and CO selectivity is at least 50% at a cell potential of 3.0 V. In some embodiments, the polymer electrolyte membrane comprises a polymer in which a constituent monomer is (p-vinylbenzyl)-R, where R is selected from the group consisting of imidazoliums, pyridiniums and phosphoniums. In some embodiments, the polymer electrolyte membrane is a Helper Membrane comprising a polymer containing an imidazolium ligand, a pyridinium ligand, or a phosphonium ligand.

  5. Establishment of the carbon label mechanism of coal chemical products based oncarbon footprint

    Directory of Open Access Journals (Sweden)

    Wu Bishan

    Full Text Available ABSTRACT After redefining the carbon footprint and carbon label, the paper analyzesthe significance of the carbon labels under the background of the low carbon economy development, and establishes the concept of model of the carbon labels mechanism to chemical products. At the same time, the paper quantitatively studies carbon label data sourceof three kinds of coal chemical industry power products, which are fromhaving not CCS technologies of supercritical boiler of coal, using CCS technologies of supercritical boiler of coal and adopting CCS and IGCC technologies to power generation in CCI. Based on the three kinds of differences, the paper puts forward of establishing the carbon labels mechanism of chemical products under the low carbon consumption.

  6. Improving Jet Reactor Configuration for Production of Carbon Nanotubes

    Science.gov (United States)

    Povitsky, Alex

    2000-01-01

    The jet mixing reactor has been proposed for the industrial production of fullerene carbon nanotubes. Here we study the flowfield of this reactor using the SIMPLER algorithm. Hot peripheral jets are used to enhance heating of the central jet by mixing with the ambiance of reactor. Numerous configurations of peripheral jets with various number of jets, distance between nozzles, angles between the central jet and a peripheral jets, and twisted configuration of nozzles are considered. Unlike the previous studies of jet mixing, the optimal configuration of peripheral jets produces strong non-uniformity of the central jet in a cross-section. The geometrical shape of reactor is designed to obtain a uniform temperature of a catalyst.

  7. Lactulose production from cheese whey using recyclable catalyst ammonium carbonate.

    Science.gov (United States)

    Seo, Yeong Hwan; Sung, Mina; Han, Jong-In

    2016-04-15

    Ammonium carbonate ((NH4)2CO3) was used as an alkaline catalyst of lactulose production from cheese whey. Maximum yield of 29.6% was obtained at reaction time of 28.44 min, (NH4)2CO3 of 0.76% at 97°C. During reaction, (NH4)2CO3 was fully decomposed to NH3 and CO2, and these gases were recovered. To boost up NH3 recovery, various methods such as heating, aeration, and pH adjustment were applied. The optimal condition for the purpose of NH3 retrieval was temperature of up to 60°C alongside aeration. Easy separation and recovery make (NH4)2CO3 a catalyst alternative to common alkaline chemicals especially for the weak alkaline reaction.

  8. Carbon disulphide production in laboratory cultures of marine phytoplankton

    Science.gov (United States)

    Xie, Huixiang; Scarratt, Michael G.; Moore, Robert M.

    Carbon disulphide (CS 2) data were collected from axenic monocultures of six species of marine phytoplankton. The tested species included Chaetoceros calcitrans, Phaeodactylum tricornutum, Phaeocystis sp., Porphyridium purpureum, Synechococcus sp. and Isochrysis sp. For a period of between two weeks and forty days, substantial accumulation of CS 2 was found in the cultures of C. calcitrans, P. tricornutum and Phaeocystis sp., whereas the change of CS 2 concentration in the remaining cultures was insignificant. C. calcitrans had a potential for CS 2 production about 10 times higher than P. tricornutum or Phaeocystis sp. The formation of the compound was strongly dependent on the physiological state of the cultured species. More investigation is needed to elucidate the mechanisms responsible for the formation of this sulphur compound in these cultures.

  9. Mass Production of Carbon Nanofibers Using Microwave Technology.

    Science.gov (United States)

    Mubarak, N M; Abdullah, E C; Sahu, J N; Jayakumar, N S; Ganesan, P

    2015-12-01

    Carbon nanotubes (CNFs) were produced by gas phase single stage microwave assisted chemical vapour deposition (MA-CVD) using ferrocene as a catalyst and acetylene (C2H2) and hydrogen (H2) as precursor gases. The effect of the process parameters such as microwave power, radiation time, and gas ratio of C2H2/H2 was investigated. The CNFs were characterized using scanning and transmission electron microscopy (TEM), and by thermogravimetric analysis (TGA). Results reveal that the optimized conditions for CNF production were 1000 W reaction power, 35 min radiation time, and 0.8 gas ratio of C2H2/H2. TEM analyses revealed that the uniformly dispersed CNFs diameters ranging from 115-131 nm. The TGA analysis showed that the purity of CNF produced was 93%.

  10. Behavioural responses of dogs to asymmetrical tail wagging of a robotic dog replica.

    Science.gov (United States)

    Artelle, K A; Dumoulin, L K; Reimchen, T E

    2011-03-01

    Recent evidence suggests that bilateral asymmetry in the amplitude of tail wagging of domestic dogs (Canis familiaris) is associated with approach (right wag) versus withdrawal (left wag) motivation and may be the by-product of hemispheric dominance. We consider whether such asymmetry in motion of the tail, a crucial appendage in intra-specific communication in all canids, provides visual information to a conspecific leading to differential behaviour. To evaluate this, we experimentally investigated the approach behaviour of free-ranging dogs to the asymmetric tail wagging of a life-size robotic dog replica. Our data, involving 452 separate interactions, showed a significantly greater proportion of dogs approaching the model continuously without stopping when the tail wagged to the left, compared with a right wag, which was more likely to yield stops. While the results indicate that laterality of a wagging tail provides behavioural information to conspecifics, the responses are not readily integrated into the predicted behaviour based on hemispheric dominance.

  11. Replica exchange molecular dynamics optimization of tensor network states for quantum many-body systems.

    Science.gov (United States)

    Liu, Wenyuan; Wang, Chao; Li, Yanbin; Lao, Yuyang; Han, Yongjian; Guo, Guang-Can; Zhao, Yong-Hua; He, Lixin

    2015-03-01

    Tensor network states (TNS) methods combined with the Monte Carlo (MC) technique have been proven a powerful algorithm for simulating quantum many-body systems. However, because the ground state energy is a highly non-linear function of the tensors, it is easy to get stuck in local minima when optimizing the TNS of the simulated physical systems. To overcome this difficulty, we introduce a replica-exchange molecular dynamics optimization algorithm to obtain the TNS ground state, based on the MC sampling technique, by mapping the energy function of the TNS to that of a classical mechanical system. The method is expected to effectively avoid local minima. We make benchmark tests on a 1D Hubbard model based on matrix product states (MPS) and a Heisenberg J1-J2 model on square lattice based on string bond states (SBS). The results show that the optimization method is robust and efficient compared to the existing results.

  12. Carbon footprint of dairy goat milk production in New Zealand.

    Science.gov (United States)

    Robertson, Kimberly; Symes, Wymond; Garnham, Malcolm

    2015-07-01

    The aim of this study was to assess the cradle-to-farm gate carbon footprint of indoor and outdoor dairy goat farming systems in New Zealand, identifying hotspots and discussing variability and methodology. Our study was based on the International Organization for Standardization standards for life cycle assessment, although only results for greenhouse gas emissions are presented. Two functional units were included: tonnes of CO2-equivalents (CO2e) per hectare (ha) and kilograms of CO2e per kilogram of fat- and protein-corrected milk (FPCM). The study covered 5 farms, 2 farming systems, and 3yr. Two methods for the calculation of enteric methane emissions were assessed. The Lassey method, as used in the New Zealand greenhouse gas inventory, provided a more robust estimate of emissions from enteric fermentation and was used in the final calculations. The alternative dry matter intake method was shown to overestimate emissions due to use of anecdotal assumptions around actual consumption of feed. Economic allocation was applied to milk and co-products. Scenario analysis was performed on the allocation method, nitrogen content of manure, manure management, and supplementary feed choice. The average carbon footprint for the indoor farms (n=3) was 11.05 t of CO2e/ha and 0.81kg of CO2e/kg of FPCM. For the outdoor farms (n=2), the average was 5.38 t of CO2e/ha and 1.03kg of CO2e/kg of FPCM. The average for all 5 farms was 8.78 t of CO2e/ha and 0.90kg of CO2e/kg of FPCM. The results showed relatively high variability due to differences in management practices between farms. The 5 farms covered 10% of the total dairy goat farms but may not be representative of an average farm. Methane from enteric fermentation was a major emission source. The use of supplementary feed was highly variable but an important contributor to the carbon footprint. Nitrous oxide can contribute up to 18% of emissions. Indoor goat farming systems produced milk with a significantly higher carbon

  13. Carbon footprint calculation of Finnish greenhouse products; Kasvihuonetuotteiden ilmastovaikutuslaskenta. Loppuraportti

    Energy Technology Data Exchange (ETDEWEB)

    Yrjaenaeinen, H.; Silvenius, F.; Kaukoranta, T.; Naekkilae, J.; Saerkkae, L.; Tuhkanen, E.-M.

    2013-02-01

    This report presents the results of climate impact calculations for five products produced in Finnish greenhouses: tomatoes, cucumbers, salad crops, tulips and Elatior begonias. The study employed 16 greenhouses for the investigation; two greenhouses each for the tulips and the begonias and four each for the tomatoes, cucumbers and salad crops. Based on these calculations a greenhouse gas calculator was developed for greenhouse cultivators. The calculator is available at internet in www.kauppapuutarhaliitto.fi {yields} hiilijalanjaelki. In terms of environmental impacts this study concentrated on the climate impacts of the investigated products, and the calculations were made for the most significant greenhouse gases: carbon dioxide, methane and nitrous oxide. The following processes were included in the system boundaries: plant growing, manufacturing of lime, fertilizers and pesticides, manufacturing and disposal of pots, carbon dioxide production, irrigation, lighting, thermal curtains and cooling systems, the production and use of electricity and heat energy, distribution of products by the growers, other transportation, end-of-life and recycling. Processes excluded from the study were: distribution by other actors, retail functions, the consumer stage, and maintenance and manufacturing of infrastructure. The study used MTT's calculation model for the climate impact of food products excluding distribution and retail processes. The greenhouses selected for the study had some variation in their energy profiles and growing seasons. In addition, scenarios were created for different energy sources by using the average figures from this study. Monthly energy consumption values were also obtained from a number of the greenhouses and these were used to assess the variations in climate impact for different seasons. According to the results of the study the use of energy is the most significant source of climate impact of greenhouse products. In the tomato farms the

  14. The Carbon Reduction Effect of the Trade of Paper Products in China

    Institute of Scientific and Technical Information of China (English)

    Feng; FENG; Heliang; HUANG; Pei; ZHANG; Siying; CHEN

    2015-01-01

    Through using the data of import and export trading of China’s paper products in 2012,we utilize the method of volume source biomass equation and net primary productivity( NPP) to calculate the carbon reduction effect of papermaking raw materials trade,and utilize the method of IPCC guidelines for inventories to calculate the carbon emission effect of paper and paper products trade. The results show that the distinctive characteristics of China’s paper products trade has resulted in the dual effects on the domestic carbon emissions. On the one hand,large imports of paper-making raw materials make China reduce domestic forest felling,with the effect of carbon emission reduction. On the other hand,net exports of paper and paper products increase the domestic carbon emissions,with the effect of carbon emission. The carbon emission reduction effect of China’s paper-making raw materials trade is obvious and up to 19. 0211 million tons. This is equal to the total volume of 180. 5709 million cubic meters forest’s annual carbon sequestration. The carbon emission effect of paper and paper products trade is only 0. 5136 million tons,which is not significant compared with the former. In general,China’s paper product trade causes the significant effect on carbon emission reduction.

  15. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests.

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-08-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2 ) and tropospheric ozone (O3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3 . Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r(2) = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m(-2) ) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆NPP/∆N) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2 . Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content.

  16. Three-dimensional nanometrology of microstructures by replica molding and large-range atomic force microscopy

    DEFF Research Database (Denmark)

    Stöhr, Frederik; Michael-Lindhard, Jonas; Simons, Hugh

    2015-01-01

    We have used replica molding and large-range atomic force microscopy to characterize the threedimensional shape of high aspect ratio microstructures. Casting inverted replicas of microstructures using polydimethylsiloxane (PDMS) circumvents the inability of AFM probes to measure deep and narrow c...

  17. Finite size corrections in the random energy model and the replica approach

    Science.gov (United States)

    Derrida, Bernard; Mottishaw, Peter

    2015-01-01

    We present a systematic and exact way of computing finite size corrections for the random energy model, in its low temperature phase. We obtain explicit (though complicated) expressions for the finite size corrections of the overlap functions. In its low temperature phase, the random energy model is known to exhibit Parisi's broken symmetry of replicas. The finite size corrections given by our exact calculation can be reproduced using replicas if we make specific assumptions about the fluctuations (with negative variances!) of the number and sizes of the blocks when replica symmetry is broken. As an alternative we show that the exact expression for the non-integer moments of the partition function can be written in terms of coupled contour integrals over what can be thought of as ‘complex replica numbers’. Parisi's one step replica symmetry breaking arises naturally from the saddle point of these integrals without making any ansatz or using the replica method. The fluctuations of the ‘complex replica numbers’ near the saddle point in the imaginary direction correspond to the negative variances we observed in the replica calculation. Finally our approach allows one to see why some apparently diverging series or integrals are harmless.

  18. A Novel General Chemistry Laboratory: Creation of Biomimetic Superhydrophobic Surfaces through Replica Molding

    Science.gov (United States)

    Verbanic, Samuel; Brady, Owen; Sanda, Ahmed; Gustafson, Carolina; Donhauser, Zachary J.

    2014-01-01

    Biomimetic replicas of superhydrophobic lotus and taro leaf surfaces can be made using polydimethylsiloxane. These replicas faithfully reproduce the microstructures of the leaves' surface and can be analyzed using contact angle goniometry, self-cleaning experiments, and optical microscopy. These simple and adaptable experiments were used to…

  19. A Novel General Chemistry Laboratory: Creation of Biomimetic Superhydrophobic Surfaces through Replica Molding

    Science.gov (United States)

    Verbanic, Samuel; Brady, Owen; Sanda, Ahmed; Gustafson, Carolina; Donhauser, Zachary J.

    2014-01-01

    Biomimetic replicas of superhydrophobic lotus and taro leaf surfaces can be made using polydimethylsiloxane. These replicas faithfully reproduce the microstructures of the leaves' surface and can be analyzed using contact angle goniometry, self-cleaning experiments, and optical microscopy. These simple and adaptable experiments were used to…

  20. Fabrication of free-standing replicas of fragile, laminar, chitinous biotemplates.

    Science.gov (United States)

    Lakhtakia, Akhlesh; Martín-Palma, Raúl J; Motyka, Michael A; Pantano, Carlo G

    2009-09-01

    The conformal-evaporated-film-by-rotation technique, followed by the dissolution of chitin in an aqueous solution of orthophosphoric acid, can be used to fabricate free-standing replicas of fragile, laminar, chitinous biotemplates. This novel approach was demonstrated using butterfly wings as biotemplates and GeSeSb chalcogenide glass for replicas.

  1. An integrated new product development framework - an application on green and low-carbon products

    Science.gov (United States)

    Lin, Chun-Yu; Lee, Amy H. I.; Kang, He-Yau

    2015-03-01

    Companies need to be innovative to survive in today's competitive market; thus, new product development (NPD) has become very important. This research constructs an integrated NPD framework for developing new products. In stage one, customer attributes (CAs) and engineering characteristics (ECs) for developing products are collected, and fuzzy interpretive structural modelling (FISM) is applied to understand the relationships among these critical factors. Based on quality function deployment (QFD), a house of quality is then built, and fuzzy analytic network process (FANP) is adopted to calculate the relative importance of ECs. In stage two, fuzzy failure mode and effects analysis (FFMEA) is applied to understand the potential failures of the ECs and to determine the importance of ECs with respect to risk control. In stage three, a goal programming (GP) model is constructed to consider the outcome from the FANP-QFD, FFMEA and other objectives, in order to select the most important ECs. Due to pollution and global warming, environmental protection has become an important topic. With both governments and consumers developing environmental consciousness, successful green and low-carbon NPD provides an important competitive advantage, enabling the survival or renewal of firms. The proposed framework is implemented in a panel manufacturing firm for designing a green and low-carbon product.

  2. Snapshot prediction of carbon productivity, carbon and protein content in a Southern Ocean diatom using FTIR spectroscopy.

    Science.gov (United States)

    Sackett, Olivia; Petrou, Katherina; Reedy, Brian; Hill, Ross; Doblin, Martina; Beardall, John; Ralph, Peter; Heraud, Philip

    2016-02-01

    Diatoms, an important group of phytoplankton, bloom annually in the Southern Ocean, covering thousands of square kilometers and dominating the region's phytoplankton communities. In their role as the major food source to marine grazers, diatoms supply carbon, nutrients and energy to the Southern Ocean food web. Prevailing environmental conditions influence diatom phenotypic traits (for example, photophysiology, macromolecular composition and morphology), which in turn affect the transfer of energy, carbon and nutrients to grazers and higher trophic levels, as well as oceanic biogeochemical cycles. The paucity of phenotypic data on Southern Ocean phytoplankton limits our understanding of the ecosystem and how it may respond to future environmental change. Here we used a novel approach to create a 'snapshot' of cell phenotype. Using mass spectrometry, we measured nitrogen (a proxy for protein), total carbon and carbon-13 enrichment (carbon productivity), then used this data to build spectroscopy-based predictive models. The models were used to provide phenotypic data for samples from a third sample set. Importantly, this approach enabled the first ever rate determination of carbon productivity from a single time point, circumventing the need for time-series measurements. This study showed that Chaetoceros simplex was less productive and had lower protein and carbon content during short-term periods of high salinity. Applying this new phenomics approach to natural phytoplankton samples could provide valuable insight into understanding phytoplankton productivity and function in the marine system.

  3. Parametric Study of Carbon Nanotube Production by Laser Ablation Process

    Science.gov (United States)

    Arepalli, Sivaram; Nikolaev, Pavel; Holmes, William; Hadjiev, Victor; Scott, Carl

    2002-01-01

    Carbon nanotubes form a new class of nanomaterials that are presumed to have extraordinary mechanical, electrical and thermal properties. The single wall nanotubes (SWNTs) are estimated to be 100 times stronger than steel with 1/6th the weight; electrical carrying capacity better than copper and thermal conductivity better than diamond. Applications of these SWNTs include possible weight reduction of aerospace structures, multifunctional materials, nanosensors and nanoelectronics. Double pulsed laser vaporization process produces SWNTs with the highest percentage of nanotubes in the output material. The normal operating conditions include a green laser pulse closely followed by an infrared laser pulse. Lasers ab late a metal-containing graphite target located in a flow tube maintained in an oven at 1473K with argon flow of 100 sccm at a 500 Torr pressure. In the present work a number of production runs were carried out, changing one operating condition at a time. We have studied the effects of nine parameters, including the sequencing of the laser pulses, pulse separation times, laser energy densities, the type of buffer gas used, oven temperature, operating pressure, flow rate and inner flow tube diameters. All runs were done using the same graphite target. The collected nanotube material was characterized by a variety of analytical techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman and thermo gravimetric analysis (TGA). Results indicate trends that could be used to optimize the process and increase the efficiency of the production process.

  4. Regulation of ROS Production and Vascular Function by Carbon Monoxide

    Directory of Open Access Journals (Sweden)

    Yoon Kyung Choi

    2012-01-01

    Full Text Available Carbon monoxide (CO is a gaseous molecule produced from heme by heme oxygenase (HO. CO interacts with reduced iron of heme-containing proteins, leading to its involvement in various cellular events via its production of mitochondrial reactive oxygen species (ROS. CO-mediated ROS production initiates intracellular signal events, which regulate the expression of adaptive genes implicated in oxidative stress and functions as signaling molecule for promoting vascular functions, including angiogenesis and mitochondrial biogenesis. Therefore, CO generated either by exogenous delivery or by HO activity can be fundamentally involved in regulating mitochondria-mediated redox cascades for adaptive gene expression and improving blood circulation (i.e., O2 delivery via neovascularization, leading to the regulation of mitochondrial energy metabolism. This paper will highlight the biological effects of CO on ROS generation and cellular redox changes involved in mitochondrial metabolism and angiogenesis. Moreover, cellular mechanisms by which CO is exploited for disease prevention and therapeutic applications will also be discussed.

  5. Soil Carbon Dioxide Production and Surface Fluxes: Subsurface Physical Controls

    Science.gov (United States)

    Risk, D.; Kellman, L.; Beltrami, H.

    Soil respiration is a critical determinant of landscape carbon balance. Variations in soil temperature and moisture patterns are important physical processes controlling soil respiration which need to be better understood. Relationships between soil respi- ration and physical controls are typically addressed using only surface flux data but other methods also exist which permit more rigorous interpretation of soil respira- tion processes. Here we use a combination of subsurface CO_{2} concentrations, surface CO_{2} fluxes and detailed physical monitoring of the subsurface envi- ronment to examine physical controls on soil CO_{2} production at four climate observatories in Eastern Canada. Results indicate that subsurface CO_{2} produc- tion is more strongly correlated to the subsurface thermal environment than the surface CO_{2} flux. Soil moisture was also found to have an important influence on sub- surface CO_{2} production, particularly in relation to the soil moisture - soil profile diffusivity relationship. Non-diffusive profile CO_{2} transport appears to be im- portant at these sites, resulting in a de-coupling of summertime surface fluxes from subsurface processes and violating assumptions that surface CO_{2} emissions are the result solely of diffusion. These results have implications for the study of soil respiration across a broad range of terrestrial environments.

  6. Hamiltonian replica-exchange simulations with adaptive biasing of peptide backbone and side chain dihedral angles.

    Science.gov (United States)

    Ostermeir, Katja; Zacharias, Martin

    2014-01-15

    A Hamiltonian Replica-Exchange Molecular Dynamics (REMD) simulation method has been developed that employs a two-dimensional backbone and one-dimensional side chain biasing potential specifically to promote conformational transitions in peptides. To exploit the replica framework optimally, the level of the biasing potential in each replica was appropriately adapted during the simulations. This resulted in both high exchange rates between neighboring replicas and improved occupancy/flow of all conformers in each replica. The performance of the approach was tested on several peptide and protein systems and compared with regular MD simulations and previous REMD studies. Improved sampling of relevant conformational states was observed for unrestrained protein and peptide folding simulations as well as for refinement of a loop structure with restricted mobility of loop flanking protein regions.

  7. Influence of carbon source on alpha-amylase production by Aspergillus oryzae

    DEFF Research Database (Denmark)

    Carlsen, Morten; Nielsen, Jens

    2001-01-01

    The influence of the carbon source on a-amylase production by Aspergillus oryzae was quantified in carbon-limited chemostat cultures. The following carbon sources were investigated: maltose, maltodextrin (different chain lengths), glucose, fructose, galactose, sucrose, glycerol, mannitol and acet......The influence of the carbon source on a-amylase production by Aspergillus oryzae was quantified in carbon-limited chemostat cultures. The following carbon sources were investigated: maltose, maltodextrin (different chain lengths), glucose, fructose, galactose, sucrose, glycerol, mannitol...... and acetate. A. oryzae did not grow on galactose as the sole carbon source, but galactose was co-metabolized together with glucose. Relative to that on low glucose concentration (below 10 mg/l), productivity was found to be higher during growth on maltose and maltodextrins, whereas it was lower during growth...

  8. Dutch (organic) agriculture, carbon sequestration and energy production

    NARCIS (Netherlands)

    Burgt, van der G.J.H.M.; Staps, S.; Timmermans, B.

    2010-01-01

    Carbon sequestration in soils is often mentioned in the discussions about climate changes. In this paper the opportunities for carbon sequestration in Dutch agriculture are discussed at farm and national level. Farm internal carbon sources are already completely used in livestock farming. The effect

  9. Yarn spun from carbon nanotube forests: Production, structure, properties and applications

    Institute of Scientific and Technical Information of China (English)

    Menghe Miao

    2013-01-01

    The discovery ofdrawable carbon nanotube forests opened up the possibility of constructing a wide range of pure carbon nanotube macrostructures and sparked interests in developing applications from these structures,especially pure carbon nanotube yarns.This review examines the various facets of the drawable carbon nanotube forests,synthesis and drawability,and their resulting yarns,structure,production,properties and applications.The structure,formation and properties of carbon nanotube yarns are compared with those of conventional textile yarns in order to obtain a better understanding of the science,structural mechanics and processing technology involved in carbon nanotube yarns.

  10. Replica analysis for the duality of the portfolio optimization problem

    Science.gov (United States)

    Shinzato, Takashi

    2016-11-01

    In the present paper, the primal-dual problem consisting of the investment risk minimization problem and the expected return maximization problem in the mean-variance model is discussed using replica analysis. As a natural extension of the investment risk minimization problem under only a budget constraint that we analyzed in a previous study, we herein consider a primal-dual problem in which the investment risk minimization problem with budget and expected return constraints is regarded as the primal problem, and the expected return maximization problem with budget and investment risk constraints is regarded as the dual problem. With respect to these optimal problems, we analyze a quenched disordered system involving both of these optimization problems using the approach developed in statistical mechanical informatics and confirm that both optimal portfolios can possess the primal-dual structure. Finally, the results of numerical simulations are shown to validate the effectiveness of the proposed method.

  11. Nontrivial Critical Fixed Point for Replica-Symmetry-Breaking Transitions

    Science.gov (United States)

    Charbonneau, Patrick; Yaida, Sho

    2017-05-01

    The transformation of the free-energy landscape from smooth to hierarchical is one of the richest features of mean-field disordered systems. A well-studied example is the de Almeida-Thouless transition for spin glasses in a magnetic field, and a similar phenomenon—the Gardner transition—has recently been predicted for structural glasses. The existence of these replica-symmetry-breaking phase transitions has, however, long been questioned below their upper critical dimension, du=6 . Here, we obtain evidence for the existence of these transitions in d

  12. Searching near-replicas of images via clustering

    Science.gov (United States)

    Chang, Edward Y.; Li, Chen; Wang, James Z.; Mork, Peter; Wiederhold, Gio

    1999-08-01

    Internet piracy has been one of the major concerns for Web publishing. In this study we present a system, RIME, that we have prototyped for detecting unauthorized image copying on the WWW. To speed up the copy detection, RIME uses a new clustering/hashing approach that first clusters similar images on adjacent disk cylinders and then builds indexes to access the clusters made in this way. Searching for the replicas of an image often takes just one IO to loop up the location of the cluster containing similar objects and one sequential file IO to read in this cluster. Our experimental results show that RIME can detect images copies both more efficiently and effectively than the traditional content- based image retrieval systems that use tree-like structures to index images. In addition, RIME copes well with image format conversion, resampling, requantization and geometric transformation.

  13. Replica exchange Monte Carlo applied to hard spheres.

    Science.gov (United States)

    Odriozola, Gerardo

    2009-10-14

    In this work a replica exchange Monte Carlo scheme which considers an extended isobaric-isothermal ensemble with respect to pressure is applied to study hard spheres (HSs). The idea behind the proposal is expanding volume instead of increasing temperature to let crowded systems characterized by dominant repulsive interactions to unblock, and so, to produce sampling from disjoint configurations. The method produces, in a single parallel run, the complete HS equation of state. Thus, the first order fluid-solid transition is captured. The obtained results well agree with previous calculations. This approach seems particularly useful to treat purely entropy-driven systems such as hard body and nonadditive hard mixtures, where temperature plays a trivial role.

  14. Scalable replica-exchange framework for Wang-Landau sampling.

    Science.gov (United States)

    Vogel, Thomas; Li, Ying Wai; Wüst, Thomas; Landau, David P

    2014-08-01

    We investigate a generic, parallel replica-exchange framework for Monte Carlo simulations based on the Wang-Landau method. To demonstrate its advantages and general applicability for massively parallel simulations of complex systems, we apply it to lattice spin models, the self-assembly process in amphiphilic solutions, and the adsorption of molecules on surfaces. While of general current interest, the latter phenomena are challenging to study computationally because of multiple structural transitions occurring over a broad temperature range. We show how the parallel framework facilitates simulations of such processes and, without any loss of accuracy or precision, gives a significant speedup and allows for the study of much larger systems and much wider temperature ranges than possible with single-walker methods.

  15. Scalable replica-exchange framework for Wang-Landau sampling

    Science.gov (United States)

    Vogel, Thomas; Li, Ying Wai; Wüst, Thomas; Landau, David P.

    2014-08-01

    We investigate a generic, parallel replica-exchange framework for Monte Carlo simulations based on the Wang-Landau method. To demonstrate its advantages and general applicability for massively parallel simulations of complex systems, we apply it to lattice spin models, the self-assembly process in amphiphilic solutions, and the adsorption of molecules on surfaces. While of general current interest, the latter phenomena are challenging to study computationally because of multiple structural transitions occurring over a broad temperature range. We show how the parallel framework facilitates simulations of such processes and, without any loss of accuracy or precision, gives a significant speedup and allows for the study of much larger systems and much wider temperature ranges than possible with single-walker methods.

  16. Scalable replica-exchange framework for Wang Landau sampling

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Thomas [University of Georgia, Athens, GA; Li, Ying Wai [ORNL; Wuest, Thomas [Swiss Federal Research Institute, Switzerland; Landau, David P [University of Georgia, Athens, GA

    2014-01-01

    We investigate a generic, parallel replica-exchange framework for Monte Carlo simulations based on the Wang Landau method. To demonstrate its advantages and general applicability for massively parallel simulations of complex systems, we apply it to lattice spin models, the self-assembly process in amphiphilic solutions, and the adsorption of molecules on surfaces. While of general, current interest, the latter phenomena are challenging to study computationally because of multiple structural transitions occurring over a broad temperature range. We show how the parallel framework facilitates simulations of such processes and, without any loss of accuracy or precision, gives a significant speedup and allows for the study of much larger systems and much wider temperature ranges than possible with single-walker methods.

  17. Beyond Virtual Replicas: 3D Modeling and Maltese Prehistoric Architecture

    Directory of Open Access Journals (Sweden)

    Filippo Stanco

    2013-01-01

    Full Text Available In the past decade, computer graphics have become strategic for the development of projects aimed at the interpretation of archaeological evidence and the dissemination of scientific results to the public. Among all the solutions available, the use of 3D models is particularly relevant for the reconstruction of poorly preserved sites and monuments destroyed by natural causes or human actions. These digital replicas are, at the same time, a virtual environment that can be used as a tool for the interpretative hypotheses of archaeologists and as an effective medium for a visual description of the cultural heritage. In this paper, the innovative methodology and aims and outcomes of a virtual reconstruction of the Borg in-Nadur megalithic temple, carried out by Archeomatica Project of the University of Catania, are offered as a case study for a virtual archaeology of prehistoric Malta.

  18. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Dady B. Dadyburjor; Mark E. Heavner; Manoj Katakdaunde; Liviu Magean; J. Joshua Maybury; Alfred H. Stiller; Joseph M. Stoffa; John W. Zondlo

    2006-08-01

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, and porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, hydrotreatment of solvent was completed in preparation for pitch fabrication for graphite electrodes. Coal digestion has lagged but is expected to be complete by next quarter. Studies are reported on coal dissolution, pitch production, foam synthesis using physical blowing agents, and alternate coking techniques.

  19. Sustainability: The capacity of smokeless biomass pyrolysis for energy production, global carbon capture and sequestration

    Science.gov (United States)

    Application of modern smokeless biomass pyrolysis for biochar and biofuel production is potentially a revolutionary approach for global carbon capture and sequestration at gigatons of carbon (GtC) scales. A conversion of about 7% of the annual terrestrial gross photosynthetic product (120 GtC y-1) i...

  20. Production and carbon allocation in a clonal Eucalyptus plantation with water and nutrient manipulations

    Science.gov (United States)

    Jose Luiz Stape; Dan Binkley; Michael G. Ryan

    2008-01-01

    We examined resource limitations on growth and carbon allocation in a fast-growing, clonal plantation of Eucalyptus grandis urophylla in Brazil by characterizing responses to annual rainfall, and response to irrigation and fertililization for 2 years. Productivity measures included gross primary production (GPP), total belowground carbon allocation (...

  1. Greenhouse gas emissions in milk and dairy product chains: Improving the carbon footprint of dairy products

    Energy Technology Data Exchange (ETDEWEB)

    Flysjoe, A.M.

    2012-11-01

    The present PhD project has focused on some of the most critical methodological aspects influencing GHG emission estimates of milk and dairy products and how the methodology can be improved. In addition, the Carbon Footprint (CF) for different types of dairy products has been analysed. Based on these results, mitigation options have been identified along the entire dairy value chain. The key methodological challenges analysed in the present study are: estimation of CH{sub 4} and N{sub 2}O emissions, assessment of CO{sub 2} emissions from land use change (LUC), co-product handling, and definition of the functional unit. Estimates of the biogenic emissions CH{sub 4} and N{sub 2}O are associated with large uncertainties due to the complexity and natural variation in biological processes. Accounting for these variations resulted in a {+-}30-50% variation in the CF for milk in Sweden and New Zealand (excluding emissions from LUC). The inclusion of emissions from LUC can drastically affect the CF of dairy products, and different models can even provide contradictory results. Thus, it is suggested that emissions associated with LUC are reported separately and that underlying assumptions are clearly explained. Accounting for the by-product beef is decisive for the CF of milk, and when designing future strategies for the dairy sector, milk and meat production needs to be addressed in an integrated approach. It is shown that an increase in milk yield per cow does not necessarily result in a lower CF of milk, when taking into account the alternative production of the by-product beef. This demonstrates that it is important to investigate interactions between different product chains, i.e. to apply system thinking. The CF of dairy products from Arla Foods analysed in the present study range from: 1.2-5.5 kg CO{sub 2}e per kg fresh dairy products, 7.3-10.9 kg CO{sub 2}e per kg butter and butter blends, 4.5-9.9 kg CO{sub 2}e per kg cheese, and 1.0-17.4 kg CO{sub 2}e per kg milk

  2. New natural product carbonic anhydrase inhibitors incorporating phenol moieties.

    Science.gov (United States)

    Karioti, Anastasia; Ceruso, Mariangela; Carta, Fabrizio; Bilia, Anna-Rita; Supuran, Claudiu T

    2015-11-15

    Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the fundamental reaction of CO2 hydration in all living organisms, being actively involved in the regulation of a plethora of patho/physiological conditions. They represent a typical example of enzyme convergent evolution, as six genetically unrelated families of such enzymes were described so far. The need to find selective CA inhibitors (CAIs) triggered the investigation of natural product libraries, which proved to be a valid source of agents with such an activity, as demonstrated for the phenols, polyamines and coumarins. Herein we report an in vitro inhibition study of human (h) CA isoforms hCAs I, II, IV, VII and XII with a panel of natural polyphenols including flavones, flavonols, flavanones, flavanols, isoflavones and depsides, some of which extracted from Quercus ilex and Salvia miltiorrhiza. Several of the investigated derivatives showed interesting inhibition activity and selectivities for inhibiting some important isoforms over the off-target ones hCA I and II.

  3. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-01-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3. Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r2 = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m−2) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (ΔNPP/ΔN) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2. Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. PMID:24604779

  4. Calcium carbonate synthesis with prescribed properties based on liquid waste of soda production

    Directory of Open Access Journals (Sweden)

    E.O. Mikhailova

    2016-09-01

    Full Text Available A promising direction in solving of environmental problems of soda industry is the development of low-waste resource-saving technologies, which consist in recycling of valuable waste components with obtaining the commercial products. Aim: The aim is to establish the optimal conditions for obtaining calcium carbonate with prescribed properties from liquid waste of soda production. Materials and Methods: Chemically deposited calcium carbonate is used as filler and should have certain physical and chemical properties. To obtain a product of prescribed quality the process of calcium carbonate deposition was performed of still waste liquid, that is the waste of calcium carbonate production and contain significant amount of calcium ions, and excessive production of the purified stock solution of sodium bicarbonate, which is composed of carbonate and hydrocarbonate ions. Results: The dependence of bulk density and specific surface area of calcium carbonate sediments and degree of deposition from such technological parameters are established: method of mixing the stock solutions, the concentration and molar ratio of reactants, temperature and reaction time. Conclusions: The optimal mode of deposition process is determined and the concept of production of calcium carbonate is developed. The quality of calcium carbonate meets the modern requirements of high dispersion, low bulk density and evolved specific surface of the product.

  5. Modeling of HiPco Process for Carbon Nanotube Production

    Science.gov (United States)

    Gokcen, T.; Dateo, C. E.; Meyyappan, M.; Colbert, D. T.; Smith, D. T.; Smith, K.; Smalley, R. E.; Arnold, James O. (Technical Monitor)

    2000-01-01

    High-pressure carbon monoxide (HiPco) reactor, developed at Rice University, is used to produce single-walled carbon nanotubes (SWNT) from gas-phase reactions of iron carbonyl and nickel carbonyl in carbon monoxide at high pressures (10 - 100 atm). Computational modeling is used to better understand the HiPco process. In the present model, decomposition of the precursor, metal cluster formation and growth, and carbon nanotube growth are addressed. Decomposition of precursor molecules is necessary to initiate metal cluster formation. The metal clusters serve as catalysts for carbon nanotube growth. Diameter of metal clusters and number of atoms in these clusters are some of the essential information for predicting carbon nanotube formation and growth, which is then modeled by Boudouard reaction (2CO ---> C(s) + CO2) with metal catalysts. The growth kinetic model is integrated with a two-dimensional axisymmetric reactor flow model to predict reactor performance.

  6. Production of activated carbon from a new precursor: Molasses

    Science.gov (United States)

    Legrouri, K.; Ezzine, M.; Ichcho, S.; Hannache, H.; Denoyel, R.; Pailler, R.; Naslain, R.

    2005-03-01

    Activated carbon has been prepared from molasses, a natural precursor of vegetable origin resulting from the sugar industry in Morocco. The preparation of the activated carbon from the molasses has been carried out by impregnation of the precursor with sulfuric acid, followed by carbonization. The adsorption capacity, the BET surface area, and the pore volume of the activated carbon were determined. The micropore volume was assessed by Dubinin- Radushkevich (DR) equation. The activated materials are mainly microporous and show the type I isotherm of the Brunauer classification for nitrogen adsorption. The activation in steam yielded a carbon that contains both micropores and supermicropores. Analysis of the nitrogen isotherm by BET and DR methods established that most of obtained carbons are highly microporous, with high surface areas (≥ 1200 m2/g) and very low mesoporosity.

  7. Application of thermal analysis techniques in activated carbon production

    Science.gov (United States)

    Donnals, G.L.; DeBarr, J.A.; Rostam-Abadi, M.; Lizzio, A.A.; Brady, T.A.

    1996-01-01

    Thermal analysis techniques have been used at the ISGS as an aid in the development and characterization of carbon adsorbents. Promising adsorbents from fly ash, tires, and Illinois coals have been produced for various applications. Process conditions determined in the preparation of gram quantities of carbons were used as guides in the preparation of larger samples. TG techniques developed to characterize the carbon adsorbents included the measurement of the kinetics of SO2 adsorption, the performance of rapid proximate analyses, and the determination of equilibrium methane adsorption capacities. Thermal regeneration of carbons was assessed by TG to predict the life cycle of carbon adsorbents in different applications. TPD was used to determine the nature of surface functional groups and their effect on a carbon's adsorption properties.

  8. Internal structure analysis of particle-double network gels used in a gel organ replica

    Science.gov (United States)

    Abe, Mei; Arai, Masanori; Saito, Azusa; Sakai, Kazuyuki; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    In recent years, the fabrication of patient organ replicas using 3D printers has been attracting a great deal of attention in medical fields. However, the cost of these organ replicas is very high as it is necessary to employ very expensive 3D printers and printing materials. Here we present a new gel organ replica, of human kidney, fabricated with a conventional molding technique, using a particle-double network hydrogel (P-DN gel). The replica is transparent and has the feel of a real kidney. It is expected that gel organ replicas produced this way will be a useful tool for the education of trainee surgeons and clinical ultrasonography technologists. In addition to developing a gel organ replica, the internal structure of the P-DN gel used is also discussed. Because the P-DN gel has a complex structure comprised of two different types of network, it has not been possible to investigate them internally in detail. Gels have an inhomogeneous network structure. If it is able to get a more uniform structure, it is considered that this would lead to higher strength in the gel. In the present study we investigate the structure of P-DN gel, using the gel organ replica. We investigated the internal structure of P-DN gel using Scanning Microscopic Light Scattering (SMILS), a non-contacting and non-destructive.

  9. Fabrication of the replica templated from butterfly wing scales with complex light trapping structures

    Science.gov (United States)

    Han, Zhiwu; Li, Bo; Mu, Zhengzhi; Yang, Meng; Niu, Shichao; Zhang, Junqiu; Ren, Luquan

    2015-11-01

    The polydimethylsiloxane (PDMS) positive replica templated twice from the excellent light trapping surface of butterfly Trogonoptera brookiana wing scales was fabricated by a simple and promising route. The exact SiO2 negative replica was fabricated by using a synthesis method combining a sol-gel process and subsequent selective etching. Afterwards, a vacuum-aided process was introduced to make PDMS gel fill into the SiO2 negative replica, and the PDMS gel was solidified in an oven. Then, the SiO2 negative replica was used as secondary template and the structures in its surface was transcribed onto the surface of PDMS. At last, the PDMS positive replica was obtained. After comparing the PDMS positive replica and the original bio-template in terms of morphology, dimensions and reflectance spectra and so on, it is evident that the excellent light trapping structures of butterfly wing scales were inherited by the PDMS positive replica faithfully. This bio-inspired route could facilitate the preparation of complex light trapping nanostructure surfaces without any assistance from other power-wasting and expensive nanofabrication technologies.

  10. Thermocatalytic process for CO.sub.2-free production of hydrogen and carbon from hydrocarbons

    Science.gov (United States)

    Muradov, Nazim Z.

    2011-08-23

    A novel process and apparatus are disclosed for sustainable CO.sub.2-free production of hydrogen and carbon by thermocatalytic decomposition (dissociation, pyrolysis, cracking) of hydrocarbon fuels over carbon-based catalysts in the absence of air and/or water. The apparatus and thermocatalytic process improve the activity and stability of carbon catalysts during the thermocatalytic process and produce both high purity hydrogen (at least, 99.0 volume %) and carbon, from any hydrocarbon fuel, including sulfurous fuels. In a preferred embodiment, production of hydrogen and carbon is achieved by both internal and external activation of carbon catalysts. Internal activation of carbon catalyst is accomplished by recycling of hydrogen-depleted gas containing unsaturated and aromatic hydrocarbons back to the reactor. External activation of the catalyst can be achieved via surface gasification with hot combustion gases during catalyst heating. The process and apparatus can be conveniently integrated with any type of fuel cell to generate electricity.

  11. Feasibility study of production of radioactive carbon black or carbon nanotubes in cyclotron facilities for nanobioscience applications.

    Science.gov (United States)

    Abbas, K; Simonelli, F; Holzwarth, U; Cydzik, I; Bulgheroni, A; Gibson, N; Kozempel, J

    2013-03-01

    A feasibility study regarding the production of radioactive carbon black and nanotubes has been performed by proton beam irradiation. Experimental and theoretical excitation functions of the nuclear reaction (nat)C(p,x)(7)Be in the proton energy range 24-38 MeV are reported, with an acceptable agreement. We have demonstrated that sufficient activities of (7)Be radioisotope can be produced in carbon black and nanotube that would facilitate studies of their possible impact on human and environment.

  12. Techno-economic evaluation of different CO2-based processes for dimethyl carbonate production

    DEFF Research Database (Denmark)

    Kongpanna, Pichayapan; Pavarajarn, Varong; Gani, Rafiqul

    2015-01-01

    ; and (4) synthesis from ethylene carbonate. The processes avoid the use of toxic chemicals such as phosgene, CO and NO that are required in conventional DMC production processes. From preliminary thermodynamic analysis, the yields of DMC are found to have the following order (higher to lower): ethylene......In this work, several chemical processes for production of dimethyl carbonate (DMC) based on CO2 utilization are evaluated. Four CO2-based processes for production of DMC are considered: (1) direct synthesis from CO2 and methanol; (2) synthesis from urea; (3) synthesis from propylene carbonate...... carbonate route > urea route > propylene carbonate route > direct synthesis from CO2. Therefore, only the urea and ethylene carbonate routes are further investigated by comparing their performances with the commercial BAYER process on the basis of kg of DMC produced at a specific purity. The ethylene...

  13. Disequilibrium δ18O values in microbial carbonates as a tracer of metabolic production of dissolved inorganic carbon

    Science.gov (United States)

    Thaler, Caroline; Millo, Christian; Ader, Magali; Chaduteau, Carine; Guyot, François; Ménez, Bénédicte

    2017-02-01

    both disequilibrium effects are triggered by the metabolic production of CO2, which is common in many microbially-mediated carbonation processes, leads us to propose that metabolically-induced offsets from isotopic equilibrium in microbial carbonates may be more common than previously considered. Therefore, precaution should be taken when using the oxygen isotope signature of microbial carbonates for diagenetic and paleoenvironmental reconstructions.

  14. Carbon footprint assessment for a local branded pure milk product: a lifecycle based approach

    Directory of Open Access Journals (Sweden)

    Rui ZHAO

    Full Text Available Abstract This paper provides a simplified life cycle based assessment for a local branded pure milk product, to measure its related carbon footprint, including production of raw milk, dairy processing, transportation of milk product and disposal of packaging waste. The results show that the total carbon footprint of the pure milk is 1120g CO2/L. The production of raw milk is identified as the major contributor to the carbon footprint. This contribution has amounted to 843 g of CO2 per liter of pure milk, accounted for 75.27% of the total carbon footprint. The carbon footprint of product transportation is 38 g of CO2 per liter, which accounts for 3.39% of the total. The carbon footprint related to the dairy processing and disposal of waste packaging is 173 g of CO2 per liter and 66 g of CO2 per liter, accounting for 15.45% and 5.89% of the total, respectively. The carbon footprint assessment intends to help dairy enterprises identify the intensive sectors of carbon emissions, and provides insight into improvement of product environmental performances.

  15. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Chong Chen; Dady Dadyburjor; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2005-07-13

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. The Hydrotreatment Facility is being prepared for trials with coal liquids. Raw coal tar distillate trials have been carried out by heating coal tar in the holding tank in the Hydrotreatment Facility. The liquids are centrifuged to warm the system up in preparation for the coal liquids. The coal tar distillate is then recycled to keep the centrifuge hot. In this way, the product has been distilled such that a softening point of approximately 110 C is reached. Then an ash test is conducted.

  16. Methane cracking over commercial carbons for hydrogen production

    Directory of Open Access Journals (Sweden)

    J. Sarada Prasad, Vivek Dhand, V. Himabindu Y. Anjaneyulu

    2010-07-01

    Full Text Available A bench scale unit has been designed and developed indigenously for producing hydrogen from methane in the presence of a catalyst. Five number carbon samples (two carbon blacks and three activated carbons of different origin procured from Indian market have been investigated in the bench scale unit with stainless steel continuous fixed bed reactor at a constant temperature of 850 0C and space velocity (VHSV of 1.62 Lit/hr.g. Among all the five samples, activated carbon produced from coconut shells with BET surface area of 1185 m2/g showed promising activity with a sustainability factor (R1/R0 of 0.33 and initial activity (R0 of 0.623 mmol/min.g of catalyst. Accumulated carbon yield (over a period of four hours of the above catalyst is 564 mg/g of catalyst.

  17. Combined hydrogen production and storage with subsequent carbon crystallization.

    Science.gov (United States)

    Lueking, Angela D; Gutierrez, Humberto R; Fonseca, Dania A; Narayanan, Deepa L; Van Essendelft, Dirk; Jain, Puja; Clifford, Caroline E B

    2006-06-21

    We provide evidence of low-temperature hydrogen evolution and possible hydrogen trapping in an anthracite coal derivative, formed via reactive ball milling with cyclohexene. No molecular hydrogen is added to the process. Raman-active molecular hydrogen vibrations are apparent in samples at atmospheric conditions (300 K, 1 bar) for samples prepared 1 year previously and stored in ambient air. Hydrogen evolves slowly at room temperature and is accelerated upon sample heating, with a first increase in hydrogen evolution occurring at approximately 60 degrees C. Subsequent chemical modification leads to the observation of crystalline carbons, including nanocrystalline diamond surrounded by graphene ribbons, other sp2-sp3 transition regions, purely graphitic regions, and a previously unidentified crystalline carbon form surrounded by amorphous carbon. The combined evidence for hydrogen trapping and carbon crystallization suggests hydrogen-induced crystallization of the amorphous carbon materials, as metastable hydrogenated carbons formed via the high-energy milling process rearrange into more thermodynamically stable carbon forms and molecular hydrogen.

  18. Caribbean-wide decline in carbonate production threatens coral reef growth.

    Science.gov (United States)

    Perry, Chris T; Murphy, Gary N; Kench, Paul S; Smithers, Scott G; Edinger, Evan N; Steneck, Robert S; Mumby, Peter J

    2013-01-01

    Global-scale deteriorations in coral reef health have caused major shifts in species composition. One projected consequence is a lowering of reef carbonate production rates, potentially impairing reef growth, compromising ecosystem functionality and ultimately leading to net reef erosion. Here, using measures of gross and net carbonate production and erosion from 19 Caribbean reefs, we show that contemporary carbonate production rates are now substantially below historical (mid- to late-Holocene) values. On average, current production rates are reduced by at least 50%, and 37% of surveyed sites were net erosional. Calculated accretion rates (mm year(-1)) for shallow fore-reef habitats are also close to an order of magnitude lower than Holocene averages. A live coral cover threshold of ~10% appears critical to maintaining positive production states. Below this ecological threshold carbonate budgets typically become net negative and threaten reef accretion. Collectively, these data suggest that recent ecological declines are now suppressing Caribbean reef growth potential.

  19. Synthetic Strategies toward Natural Products Containing Contiguous Stereogenic Quaternary Carbon Atoms.

    Science.gov (United States)

    Büschleb, Martin; Dorich, Stéphane; Hanessian, Stephen; Tao, Daniel; Schenthal, Kyle B; Overman, Larry E

    2016-03-18

    Strategies for the total synthesis of complex natural products that contain two or more contiguous stereogenic quaternary carbon atoms in their intricate structures are reviewed with 12 representative examples. Emphasis has been put on methods to create quaternary carbon stereocenters, including syntheses of the same natural product by different groups, thereby showcasing the diversity of thought and individual creativity. A compendium of selected natural products containing two or more contiguous stereogenic quaternary carbon atoms and key reactions in their total or partial syntheses is provided in the Supporting Information.

  20. Carbon emissions from U.S. ethylene production under climate change policies.

    Science.gov (United States)

    Ruth, Matthias; Amato, Anthony D; Davidsdottir, Brynhildur

    2002-01-15

    This paper presents the results from a dynamic computer model of U.S. ethylene production, designed to explore implications of alternative climate change policies for the industry's energy use and carbon emissions profiles. The model applies to the aggregate ethylene industry but distinguishes its main cracker types, fuels used as feedstocks and for process energy, as well as the industry's capital vintage structure and vintage-specific efficiencies. Results indicate that policies which increase the cost of carbon of process energy-such as carbon taxes or carbon permit systems-are relatively blunt instruments for cutting carbon emissions from ethylene production. In contrast, policies directly affecting the relative efficiencies of new to old capital-such as R&D stimuli or accelerated depreciation schedules-may be more effective in leveraging the industry's potential for carbon emissions reductions.

  1. Hydrogen production using thermocatalytic decomposition of methane on Ni30/activated carbon and Ni30/carbon black.

    Science.gov (United States)

    Srilatha, K; Viditha, V; Srinivasulu, D; Ramakrishna, S U B; Himabindu, V

    2016-05-01

    Hydrogen is an energy carrier of the future need. It could be produced from different sources and used for power generation or as a transport fuel which mainly in association with fuel cells. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional fuels. Thermocatalytic decomposition (TCD) of methane is one of the most advantageous processes, which will meet the future demand, hence an attractive route for COx free environment. The present study deals with the production of hydrogen with 30 wt% of Ni impregnated in commercially available activated carbon and carbon black catalysts (samples coded as Ni30/AC and Ni30/CB, respectively). These combined catalysts were not attempted by previous studies. Pure form of hydrogen is produced at 850 °C and volume hourly space velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts. The analysis (X-ray diffraction (XRD)) of the catalysts reveals moderately crystalline peaks of Ni, which might be responsible for the increase in catalytic life along with formation of carbon fibers. The activity of carbon black is sustainable for a longer time compared to that of activated carbon which has been confirmed by life time studies (850 °C and 54 sccm of methane).

  2. The production of precipitated calcium carbonate from industrial gypsum wastes

    CSIR Research Space (South Africa)

    De Beer, Morris

    2014-05-01

    Full Text Available Precipitated calcium carbonate is a material of great interest due to its large range of applications. Although there are extensive reserves of limestone worldwide, very few deposits are of sufficient quality to provide raw materials for specialised...

  3. Natural Gas Based Electricity Production and Low Carbon Technology Options

    Science.gov (United States)

    Concerns regarding air quality, global climate change, and the national energy security impacts of the intensive use of fossil fuels and their environmental impacts in the power generation sector have raised interest in alternative low carbon electricity generation technology and...

  4. Natural Gas Based Electricity Production and Low Carbon Technology Options

    Science.gov (United States)

    Concerns regarding air quality, global climate change, and the national energy security impacts of the intensive use of fossil fuels and their environmental impacts in the power generation sector have raised interest in alternative low carbon electricity generation technology and...

  5. Application of Replica Technique and SEM in Accuracy Measurement of Ceramic Crowns

    Science.gov (United States)

    Trifkovic, B.; Budak, I.; Todorovic, A.; Hodolic, J.; Puskar, T.; Jevremovic, D.; Vukelic, D.

    2012-01-01

    The paper presents a comparative study of the measuring values of the marginal gap related to the ceramic crowns made by dental CAD/CAM system using the replica technique and SEM. The study was conducted using three experimental groups, which consisted of ceramic crowns manufactured by the Cerec CAD/CAM system. The scanning procedure was carried out using three specialized dental 3D digitization systems from the Cerec family - two types of extraoral optical scanning systems and an intraoral optical scanner. Measurements of the marginal gap were carried out using the replica technique and SEM. The comparison of aggregate values of the marginal gap using the replica technique showed a statistically significant difference between the systems. The measured values of marginal gaps of ceramic crowns using the replica technique were significantly lower compared to those measured by SEM. The results indicate that the choice of technique for measuring the accuracy of ceramic crowns influences the final results of investigation.

  6. Automated magnification calibration in transmission electron microscopy using Fourier analysis of replica images.

    NARCIS (Netherlands)

    Laak, J.A.W.M. van der; Dijkman, H.B.P.M.; Pahlplatz, M.M.M.

    2006-01-01

    The magnification factor in transmission electron microscopy is not very precise, hampering for instance quantitative analysis of specimens. Calibration of the magnification is usually performed interactively using replica specimens, containing line or grating patterns with known spacing. In the pre

  7. Accelerating the convergence of replica exchange simulations using Gibbs sampling and adaptive temperature sets

    CERN Document Server

    Vogel, Thomas

    2015-01-01

    We recently introduced a novel replica-exchange scheme in which an individual replica can sample from states encountered by other replicas at any previous time by way of a global configuration database, enabling the fast propagation of relevant states through the whole ensemble of replicas. This mechanism depends on the knowledge of global thermodynamic functions which are measured during the simulation and not coupled to the heat bath temperatures driving the individual simulations. Therefore, this setup also allows for a continuous adaptation of the temperature set. In this paper, we will review the new scheme and demonstrate its capability. The method is particularly useful for the fast and reliable estimation of the microcanonical temperature T(U) or, equivalently, of the density of states g(U) over a wide range of energies.

  8. Process Reengineering of Cold Chain Logistics of Agricultural Products Based on Low-carbon Economy

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Through the process analysis of cold chain logistics of agricultural products,we find that cold chain logistics of agricultural products contradict the development model of low-carbon economy to some extent.We apply the development idea of low-carbon economy,introduce the thirdparty logistics companies,establish distribution center of cold chain logistics of agricultural products,and strengthen information sharing,to reengineer the process of cold chain logistics of agricultural products in China.The results show that applying low-carbon economy to process reengineering of cold chain logistics of agricultural products,has advantages of increasing added value of products,promoting scale merit and abating lag,plays a role in promoting emission reduction,high efficiency and environmental protection in the process of cold chain logistics of agricultural products in China.

  9. Rapid prototyping of replica knee implants for in vitro testing

    Directory of Open Access Journals (Sweden)

    Verjans Mark

    2016-09-01

    Full Text Available The understanding of the complex biomechanics of the knee is a key for an optimal implant design. To easily investigate the influence of prosthetic designs on knee biomechanics a rapid prototyping workflow for knee implants has been developed and evaluated. Therefore, different manufacturing technologies and post-treatment methods have been examined and overall seven different replica knee implants were manufactured. For evaluation, the manufacturing properties such as surface accuracy and roughness were determined and kinematic behaviour was investigated in a novel knee testing rig. It was carried out that PolyJet-Modelling with a sanded surface resulted in changed kinematic patterns compared to a usual CoCr-UHMWPE implant. However, fused deposition modelling using ABS and subsequent surface smoothening with acetone vapor showed the lowest roughness of the manufactured implants and only minor kinematic differences. For this reason this method constitutes a promising approach towards an optimal implant design for improved patient-satisfaction and long lifetime of the implant. Finally the workflow is not only limited to the knee.

  10. Critiques, replicas and proposals for the New Urbanism Vision

    Directory of Open Access Journals (Sweden)

    Alaide Retana

    2014-03-01

    Full Text Available The new urbanism (NU is a vision of planning and urban design emerged in 1993, which finds its basis in the design of traditional communities. This trend has had various criticisms and replicas, which were reviewed in relation to urban sprawl, transportation, re-densifying, mix of uses of land, design, gentrification, pedestrianization and safety, which were analyzed in the neighborhood of Santa Barbara in Toluca, Mexico. This area was chosen for being traditional and forming part of the historical center of the city, which even though it was not designed under the guidelines of the NU, it has the quality of traditional, from which the NU would theoretically has taken its essence. The objective of this analysis is to establish whether the NU has the essence of a traditional Mexican neighborhood, as well as to check if the criticisms of the NU are informed when applied to a space belonging to a Mexican historic center that has been abandoned by problems of insecurity and degradation. The general conclusion is that the traditional neighborhoods have provided design elements to the NU, which will refute some of the criticisms, however, proposals for NU in neighborhoods of his-toric centers have to be based on the community, the architecture and existing urbanism, since these elements are those that give the identity.

  11. Continuous Production of Carbon Nanotubes by Using Moving Bed Reactor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    High-quality carbon nanotubes were continuously produced by using moving bed reactor. The studies of scanning electron microscopy and transmission electron microscopy reveal their homogeneity both in inner (~ 10 nm) and outer diameter (20-40 nm) of the tubes. The studies of X-ray photoelectron spectroscopy and the oxidation of carbon nanotubes in air demonstrate that the tubes have good graphitic degree.

  12. Production of single-walled carbon nanotube grids

    Science.gov (United States)

    Hauge, Robert H; Xu, Ya-Qiong; Pheasant, Sean

    2013-12-03

    A method of forming a nanotube grid includes placing a plurality of catalyst nanoparticles on a grid framework, contacting the catalyst nanoparticles with a gas mixture that includes hydrogen and a carbon source in a reaction chamber, forming an activated gas from the gas mixture, heating the grid framework and activated gas, and controlling a growth time to generate a single-wall carbon nanotube array radially about the grid framework. A filter membrane may be produced by this method.

  13. 78 FR 4385 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic of Korea: Preliminary...

    Science.gov (United States)

    2013-01-22

    ... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic...- length carbon-quality steel plate products (CTL plate) from the Republic of Korea (Korea). The period of... Review of the Antidumping Duty Order on Certain Cut-to- Length Carbon-Quality Steel Plate Products from...

  14. 75 FR 29976 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Extension of the Final...

    Science.gov (United States)

    2010-05-28

    ... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy... antidumping duty order on certain cut-to-length carbon-quality steel plate products from Italy. See Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Preliminary Results of Antidumping Duty...

  15. 75 FR 55745 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results...

    Science.gov (United States)

    2010-09-14

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea) for the period of... preliminary results of the instant administrative review. See Corrosion-Resistant Carbon Steel Flat Products...

  16. 77 FR 24221 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission...

    Science.gov (United States)

    2012-04-23

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission... countervailing duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion- resistant carbon steel flat products from Germany and Korea would be likely to lead...

  17. 77 FR 72827 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Final...

    Science.gov (United States)

    2012-12-06

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic... on certain corrosion- resistant carbon steel flat products (``CORE'') from Germany and the Republic... Reviews'' section of this notice. \\1\\ Corrosion-Resistant Carbon Steel Flat Products From Germany and the...

  18. 78 FR 55057 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2013-09-09

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea... antidumping duty order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea.... See Corrosion-Resistant Carbon Steel Flat Products from Germany and the Republic of Korea: Revocation...

  19. 77 FR 301 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year...

    Science.gov (United States)

    2012-01-04

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year Reviews Concerning the Countervailing Duty Order on Corrosion-Resistant Carbon Steel Flat Products From Korea and the Antidumping Duty Orders on Corrosion-Resistant Carbon Steel Flat Products From Germany and...

  20. 76 FR 3613 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2011-01-20

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... review of the countervailing duty (CVD) order on corrosion-resistant carbon steel flat products (CORE..., 2008. See Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Preliminary...

  1. 77 FR 31877 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five...

    Science.gov (United States)

    2012-05-30

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five... duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion- resistant carbon steel flat products from Germany and Korea would be likely to lead to...

  2. Bioenergy by-products as soil amendments? Implications for carbon sequestration and greenhuise gas emissions

    NARCIS (Netherlands)

    Cayuela, M.L.; Oenema, O.; Kuikman, P.J.; Bakker, R.R.; Groenigen, van J.W.

    2010-01-01

    An important but little understood aspect of bioenergy production is its overall impact on soil carbon (C) and nitrogen (N) cycling. Increased energy production from biomass will inevitably lead to higher input of its by-products to the soil as amendments or fertilizers. However, it is still unclear

  3. The Environmental Impact of Industrial Bamboo Products: Life-cycle Assessment and Carbon Sequestration

    NARCIS (Netherlands)

    Vogtlander, J.G.; Van der Lugt, P.

    2014-01-01

    This report gives a Life-Cycle Assessment (LCA) and carbon footprint analysis on a selection of industrial bamboo products. The LCA is made for cradle-to-gate, plus the end-of-life stages of the bamboo products. For end-of-life it is assumed that 90% of the bamboo products are incinerated in an elec

  4. Mangrove production and carbon sinks: A revision of global budget estimates

    Science.gov (United States)

    Bouillon, S.; Borges, A.V.; Castaneda-Moya, E.; Diele, K.; Dittmar, T.; Duke, N.C.; Kristensen, E.; Lee, S.-Y.; Marchand, C.; Middelburg, J.J.; Rivera-Monroy, V. H.; Smith, T. J.; Twilley, R.R.

    2008-01-01

    Mangrove forests are highly productive but globally threatened coastal ecosystems, whose role in the carbon budget of the coastal zone has long been debated. Here we provide a comprehensive synthesis of the available data on carbon fluxes in mangrove ecosystems. A reassessment of global mangrove primary production from the literature results in a conservative estimate of ???-218 ?? 72 Tg C a-1. When using the best available estimates of various carbon sinks (organic carbon export, sediment burial, and mineralization), it appears that >50% of the carbon fixed by mangrove vegetation is unaccounted for. This unaccounted carbon sink is conservatively estimated at ??? 112 ?? 85 Tg C a-1, equivalent in magnitude to ??? 30-40% of the global riverine organic carbon input to the coastal zone. Our analysis suggests that mineralization is severely underestimated, and that the majority of carbon export from mangroves to adjacent waters occurs as dissolved inorganic carbon (DIC). CO2 efflux from sediments and creek waters and tidal export of DIC appear to be the major sinks. These processes are quantitatively comparable in magnitude to the unaccounted carbon sink in current budgets, but are not yet adequately constrained with the limited published data available so far. Copyright 2008 by the American Geophysical Union.

  5. Mangrove production and carbon sinks: a revision of global budget estimates

    NARCIS (Netherlands)

    Bouillon, S.; Borges, A.V.; Castañeda-Moya, E.; Diele, K.; Dittmar, T.; Duke, N.C.; Kristensen, E.; Lee, S.; Marchand, C.; Middelburg, J.J.; Rivera-Monroy, V.H.; Smith III, T.; Twilley, R.R.

    2008-01-01

    Mangrove forests are highly productive but globally threatened coastal ecosystems, whose role in the carbon budget of the coastal zone has long been debated. Here we provide a comprehensive synthesis of the available data on carbon fluxes in mangrove ecosystems. A reassessment of global mangrove pri

  6. The use of carbon sorbents and sorption technologies for cleaning water systems of petroleum products

    Directory of Open Access Journals (Sweden)

    Л.І. Павлюх

    2008-01-01

    Full Text Available  Sorbtional properties of carbonic sorbents on the base of pine sawdust in the processes of purification of water mediums and complicated technological solution from petroleum products and phosphorus compounds are investigated. The possibility of carbonic sorbents modification by halogen organic compounds to increase the degree of purification of water ecosystems is analyzed.

  7. Conformational sampling enhancement of replica exchange molecular dynamics simulations using swarm particle intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Kamberaj, Hiqmet, E-mail: hkamberaj@ibu.edu.mk [Department of Computer Engineering, International Balkan University, Tashko Karadza 11A, Skopje (Macedonia, The Former Yugoslav Republic of)

    2015-09-28

    In this paper, we present a new method based on swarm particle social intelligence for use in replica exchange molecular dynamics simulations. In this method, the replicas (representing the different system configurations) are allowed communicating with each other through the individual and social knowledge, in additional to considering them as a collection of real particles interacting through the Newtonian forces. The new method is based on the modification of the equations of motion in such way that the replicas are driven towards the global energy minimum. The method was tested for the Lennard-Jones clusters of N = 4,  5, and 6 atoms. Our results showed that the new method is more efficient than the conventional replica exchange method under the same practical conditions. In particular, the new method performed better on optimizing the distribution of the replicas among the thermostats with time and, in addition, ergodic convergence is observed to be faster. We also introduce a weighted histogram analysis method allowing analyzing the data from simulations by combining data from all of the replicas and rigorously removing the inserted bias.

  8. Design of replica bit line control circuit to optimize power for SRAM

    Science.gov (United States)

    Pengjun, Wang; Keji, Zhou; Huihong, Zhang; Daohui, Gong

    2016-12-01

    A design of a replica bit line control circuit to optimize power for SRAM is proposed. The proposed design overcomes the limitations of the traditional replica bit line control circuit, which cannot shut off the word line in time. In the novel design, the delay of word line enable and disable paths are balanced. Thus, the word line can be opened and shut off in time. Moreover, the chip select signal is decomposed, which prevents feedback oscillations caused by the replica bit line and the replica word line. As a result, the switch power caused by unnecessary discharging of the bit line is reduced. A 2-kb SRAM is fully custom designed in an SMIC 65-nm CMOS process. The traditional replica bit line control circuit and the new replica bit line control circuit are used in the designed SRAM, and their performances are compared with each other. The experimental results show that at a supply voltage of 1.2 V, the switch power consumption of the memory array can be reduced by 53.7%. Project supported by the Zhejiang Provincial Natural Science Foundation of China (No. LQ14F040001), the National Natural Science Foundation of China (Nos. 61274132, 61234002, 61474068), and the K. C. Wong Magna Fund in Ningbo University.

  9. GHG emissions of green coffee production : toward a standard methodology for carbon footprinting : report

    NARCIS (Netherlands)

    Sevenster, M.; Verhagen, A.

    2010-01-01

    In this project, the scope for product specific rules for carbon footprinting of (green) coffee is investigated and a proposal is drafted for further work toward actual definition and implementation of such a standard.

  10. Production of activated carbons from waste tire--process design and economical analysis.

    Science.gov (United States)

    Ko, Danny C K; Mui, Edward L K; Lau, Ken S T; McKay, Gordon

    2004-01-01

    The process design and economic analysis of process plants to produce activated carbons from waste tires and coal have been performed. The potential range of products from each process has been considered, namely for waste tire--pyro-gas, active carbon, carbon black and pyro-oil; for coal--pyro-gas and active carbons. Sensitivity analyses have been carried out on the main process factors; these are product price, production capacity, total production cost, capital investment and the tipping fee. Net present values for the two plants at various discount factors have been determined and the internal rates of return have been determined as 27.4% and 18.9% for the waste tire plant and the coal plant, respectively.

  11. Operation Mechanism of Farmers’ Professional Cooperatives from the Point of Low-Carbon Agricultural Products

    OpenAIRE

    2012-01-01

    We firstly take a look at internal logic of cluster development of low-carbon agricultural products. In combination with operation features of farmers’ professional cooperatives and actual requirements for cluster development of low-carbon agricultural products; we elaborate establishing benefit allocation mechanism, bearing education and training functions, forming low-carbon value, building low-carbon identification system, as well as realizing low-carbon value. According to these situati...

  12. Carbonate Production by Benthic Communities on Shallow Coralgal Reefs of Abrolhos Bank, Brazil.

    Directory of Open Access Journals (Sweden)

    Vanessa Moura Dos Reis

    Full Text Available The abundance of reef builders, non-builders and the calcium carbonate produced by communities established in Calcification Accretion Units (CAUs were determined in three Abrolhos Bank shallow reefs during the period from 2012 to 2014. In addition, the seawater temperature, the irradiance, and the amount and composition of the sediments were determined. The inner and outer reef arcs were compared. CAUs located on the inner reef shelf were under the influence of terrigenous sediments. On the outer reefs, the sediments were composed primarily of marine biogenic carbonates. The mean carbonate production in shallow reefs of Abrolhos was 579 ± 98 g m-2 y-1. The builder community was dominated by crustose coralline algae, while the non-builder community was dominated by turf. A marine heat wave was detected during the summer of 2013-2014, and the number of consecutive days with a temperature above or below the summer mean was positively correlated with the turf cover increase. The mean carbonate production of the shallow reefs of Abrolhos Bank was greater than the estimated carbonate production measured for artificial structures on several other shallow reefs of the world. The calcimass was higher than the non-calcareous mass, suggesting that the Abrolhos reefs are still in a positive carbonate production balance. Given that marine heat waves produce an increase of turf cover on the shallow reefs of the Abrolhos, a decrease in the cover represented by reef builders and shifting carbonate production are expected in the near future.

  13. Carbonate Production by Benthic Communities on Shallow Coralgal Reefs of Abrolhos Bank, Brazil

    Science.gov (United States)

    dos Reis, Vanessa Moura; Karez, Cláudia Santiago; Mariath, Rodrigo; de Moraes, Fernando Coreixas; de Carvalho, Rodrigo Tomazetto; Brasileiro, Poliana Silva; Bahia, Ricardo da Gama; Lotufo, Tito Monteiro da Cruz; Ramalho, Laís Vieira; de Moura, Rodrigo Leão; Francini-Filho, Ronaldo Bastos; Pereira-Filho, Guilherme Henrique; Thompson, Fabiano Lopes; Bastos, Alex Cardoso; Salgado, Leonardo Tavares; Amado-Filho, Gilberto Menezes

    2016-01-01

    The abundance of reef builders, non-builders and the calcium carbonate produced by communities established in Calcification Accretion Units (CAUs) were determined in three Abrolhos Bank shallow reefs during the period from 2012 to 2014. In addition, the seawater temperature, the irradiance, and the amount and composition of the sediments were determined. The inner and outer reef arcs were compared. CAUs located on the inner reef shelf were under the influence of terrigenous sediments. On the outer reefs, the sediments were composed primarily of marine biogenic carbonates. The mean carbonate production in shallow reefs of Abrolhos was 579 ± 98 g m-2 y-1. The builder community was dominated by crustose coralline algae, while the non-builder community was dominated by turf. A marine heat wave was detected during the summer of 2013–2014, and the number of consecutive days with a temperature above or below the summer mean was positively correlated with the turf cover increase. The mean carbonate production of the shallow reefs of Abrolhos Bank was greater than the estimated carbonate production measured for artificial structures on several other shallow reefs of the world. The calcimass was higher than the non-calcareous mass, suggesting that the Abrolhos reefs are still in a positive carbonate production balance. Given that marine heat waves produce an increase of turf cover on the shallow reefs of the Abrolhos, a decrease in the cover represented by reef builders and shifting carbonate production are expected in the near future. PMID:27119151

  14. Estimate of carbonate production by scleractinian corals at Luhuitou fringing reef, Sanya, China

    Institute of Scientific and Technical Information of China (English)

    SHI Qi; ZHAO MeiXia; ZHANG QiaoMin; YU KeFu; CHEN TianRan; LI Shu; WANG HanKui

    2009-01-01

    Carbonate production by scleractinian corals not only maintains coral reef growth, but also represents an important source of atmospheric carbon dioxide. In this paper the carbonate production by scler-actinian corals at Luhuitou fringing reef, Sanya, Hainan Island, China, is investigated with an ecological census-based method. Averaged carbonate production is 1.16±0.55 kg·m-2·a-1 and 3.52±1.32 kg·m-2·a-1 on the reef flat and reef slope, respectively, depending on the composition and distribution of corals and the intergeneric difference of skeletal growth. In response to the rapidly increasing hu-man impacts, coral carbonate production has decreased by 80%-89% at this fringing reef since the 1960s; as a result, the reef accretion rate declined and became lower than the rate of sea level rise. Further development of the Luhuitou fringing reef will switch significantly from lateral extension sea-wards to vertical growth, reflecting a response of coral reef bio-geomorphic process to strong human impacts under the background of global sea level rise. In addition, decrease in coral carbonate pro-duction reduced CO2 release from this fringing reef. In the future, it is likely that the role played by coral reefs, especially of fringing reefs, in the ocean and even in the global carbon cycle will be modified or weakened by the increasing human impacts.

  15. Carbonate Production by Benthic Communities on Shallow Coralgal Reefs of Abrolhos Bank, Brazil.

    Science.gov (United States)

    Reis, Vanessa Moura Dos; Karez, Cláudia Santiago; Mariath, Rodrigo; de Moraes, Fernando Coreixas; de Carvalho, Rodrigo Tomazetto; Brasileiro, Poliana Silva; Bahia, Ricardo da Gama; Lotufo, Tito Monteiro da Cruz; Ramalho, Laís Vieira; de Moura, Rodrigo Leão; Francini-Filho, Ronaldo Bastos; Pereira-Filho, Guilherme Henrique; Thompson, Fabiano Lopes; Bastos, Alex Cardoso; Salgado, Leonardo Tavares; Amado-Filho, Gilberto Menezes

    2016-01-01

    The abundance of reef builders, non-builders and the calcium carbonate produced by communities established in Calcification Accretion Units (CAUs) were determined in three Abrolhos Bank shallow reefs during the period from 2012 to 2014. In addition, the seawater temperature, the irradiance, and the amount and composition of the sediments were determined. The inner and outer reef arcs were compared. CAUs located on the inner reef shelf were under the influence of terrigenous sediments. On the outer reefs, the sediments were composed primarily of marine biogenic carbonates. The mean carbonate production in shallow reefs of Abrolhos was 579 ± 98 g m-2 y-1. The builder community was dominated by crustose coralline algae, while the non-builder community was dominated by turf. A marine heat wave was detected during the summer of 2013-2014, and the number of consecutive days with a temperature above or below the summer mean was positively correlated with the turf cover increase. The mean carbonate production of the shallow reefs of Abrolhos Bank was greater than the estimated carbonate production measured for artificial structures on several other shallow reefs of the world. The calcimass was higher than the non-calcareous mass, suggesting that the Abrolhos reefs are still in a positive carbonate production balance. Given that marine heat waves produce an increase of turf cover on the shallow reefs of the Abrolhos, a decrease in the cover represented by reef builders and shifting carbonate production are expected in the near future.

  16. Human skulls with turquoise inlays: pre hispanic origin or replicas?; Craneos humanos con teselas de turquesa: origen prehispanico o replicas?

    Energy Technology Data Exchange (ETDEWEB)

    Silva V, Y. [FIME-UANL, Pedro A. del Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon (Mexico); Castillo M, M.T.; Bautista M, J.P. [DRPMZA/INAH. Direccion de Registro Publico de Monumentos y Zonas Arqueologicas, Victoria 110, Copilco El Bajo, 04340 Mexico D.F. (Mexico); Arenas A, J. [IFUNAM, Circuito de la Investigacion Cientifica s/n, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)]. e-mail: ysilva@fisica.unam.mx

    2006-07-01

    The lack of archaeological context determining if the manufacture of two human skulls adorned with turquoise inlays have pre-Columbian origin or not (replicas), led to perform other studies. Under these conditions, besides orthodox methodology commonly used to assign chronology and cultural aspects as form, style, decoration, iconography, etc., it was necessary to obtain more results based on the use of characterization techniques. The techniques employed were Scanning Electron Microscopy (SEM), X-Ray Energy Dispersive Spectroscopy (EDS), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR), in order to determine the manufacture techniques and chemical composition of the materials used for the cementant. SEM analysis showed the presence of zones composed by Ca, O, C and Al. In some cases Mg, Cl, Fe and Pb were identified. High concentration of Cu was present in all samples, due to residues of turquoise inlays (CuAI{sub 6}(PO{sub 4}){sub 4}(OH){sub 8}(H{sub 2}O){sub 4}) with which the skulls were decorated. In the cementant was identified the Ca as base element of the cementant, as well as particles < 100 nm with irregular morphology and other amorphous zones. FTIR spectrums indicated the presence of organic substances that could be used as agglutinating in the cementant. The current work shows a progress identifying involved techniques in the manufacturing of two human skulls with turquoise inlays. (Author)

  17. Methane Production and Carbon Capture by Hydrate Swapping

    DEFF Research Database (Denmark)

    Mu, Liang; von Solms, Nicolas

    2016-01-01

    gas molecules in the structural lattice. In this work, we quantitatively investigate the swapping behavior from injection of pure carbon dioxide and the (CO2 + N2) binary gas mixture through artificial hydrate-bearing sandstone samples by use of a core-flooding experimental apparatus. A total of 13...... of pure carbon dioxide in swapping methane from its hydrate phase; the methane recovery efficiency in brine water systems is enhanced relative to pure water systems. The replenishment of a fresh (CO2 + N2) gas mixture into the vapor phase can be considered as an efficient extraction method because 46...... in small hydrate cages, as long as the equilibrium formation pressure of (CO2 + N2) binary gas hydrate is below that of methane hydrate, even though adding nitrogen to carbon dioxide reduces the thermodynamic driving force for the formation of a new hydrate. When other conditions are similar, the methane...

  18. TNSA and ponderomotive plasma production in enriched carbon polyethylene foils

    Science.gov (United States)

    Torrisi, L.; Cutroneo, M.; Ullschmied, J.

    2017-04-01

    Proton and carbon ion acceleration in a target-normal-sheath-acceleration regime produced by a laser intensity of 1016 W/cm2 was investigated using thin polyethylene foils. Measurements performed at the PALS facility in Prague demonstrate forward ion acceleration above 1 MeV per charge state. The ion acceleration is higher in thinner polymeric foils. In order to increase the emission yield of the proton and carbon ions, the target thickness should be enhanced, but this choice reduces drastically the ion acceleration. The use of highly absorbing stuff, such as carbon nanotubes embedded inside a polymer, enhances the ion acceleration but results in a broad ion energy distribution and a low amount of the highly accelerated ion species.

  19. Low Carbon-Oriented Optimal Reliability Design with Interval Product Failure Analysis and Grey Correlation Analysis

    OpenAIRE

    Yixiong Feng; Zhaoxi Hong; Jin Cheng; Likai Jia; Jianrong Tan

    2017-01-01

    The problem of large amounts of carbon emissions causes wide concern across the world, and it has become a serious threat to the sustainable development of the manufacturing industry. The intensive research into technologies and methodologies for green product design has significant theoretical meaning and practical value in reducing the emissions of the manufacturing industry. Therefore, a low carbon-oriented product reliability optimal design model is proposed in this paper: (1) The related...

  20. Comparing Carbon and Water Footprints for Beef Cattle Production in Southern Australia

    OpenAIRE

    2011-01-01

    Stand-alone environmental indicators based on life cycle assessment (LCA), such as the carbon footprint and water footprint, are becoming increasingly popular as a means of directing sustainable production and consumption. However, individually, these metrics violate the principle of LCA known as comprehensiveness and do not necessarily provide an indication of overall environmental impact. In this study, the carbon footprints for six diverse beef cattle production systems in southern Austral...

  1. Optimizing root system architecture in biofuel crops for sustainable energy production and soil carbon sequestration.

    Science.gov (United States)

    To, Jennifer Pc; Zhu, Jinming; Benfey, Philip N; Elich, Tedd

    2010-09-08

    Root system architecture (RSA) describes the dynamic spatial configuration of different types and ages of roots in a plant, which allows adaptation to different environments. Modifications in RSA enhance agronomic traits in crops and have been implicated in soil organic carbon content. Together, these fundamental properties of RSA contribute to the net carbon balance and overall sustainability of biofuels. In this article, we will review recent data supporting carbon sequestration by biofuel crops, highlight current progress in studying RSA, and discuss future opportunities for optimizing RSA for biofuel production and soil carbon sequestration.

  2. Sustainability Concept in Decision-Making: Carbon Tax Consideration for Joint Product Mix Decision

    Directory of Open Access Journals (Sweden)

    Wen-Hsien Tsai

    2016-11-01

    Full Text Available Carbon emissions are receiving greater scrutiny in many countries due to international forces to reduce anthropogenic global climate change. Carbon taxation is one of the most common carbon emission regulation policies, and companies must incorporate it into their production and pricing decisions. Activity-based costing (ABC and the theory of constraints (TOC have been applied to solve product mix problems; however, a challenging aspect of the product mix problem involves evaluating joint manufactured products, while reducing carbon emissions and environmental pollution to fulfill social responsibility. The aim of this paper is to apply ABC and TOC to analyze green product mix decision-making for joint products using a mathematical programming model and the joint production data of pharmaceutical industry companies for the processing of active pharmaceutical ingredients (APIs in drugs for medical use. This paper illustrates that the time-driven ABC model leads to optimal joint product mix decisions and performs sensitivity analysis to study how the optimal solution will change with the carbon tax. Our findings provide insight into ‘sustainability decisions’ and are beneficial in terms of environmental management in a competitive pharmaceutical industry.

  3. Empirical Research on China’s Carbon Productivity Decomposition Model Based on Multi-Dimensional Factors

    Directory of Open Access Journals (Sweden)

    Jianchang Lu

    2015-04-01

    Full Text Available Based on the international community’s analysis of the present CO2 emissions situation, a Log Mean Divisia Index (LMDI decomposition model is proposed in this paper, aiming to reflect the decomposition of carbon productivity. The model is designed by analyzing the factors that affect carbon productivity. China’s contribution to carbon productivity is analyzed from the dimensions of influencing factors, regional structure and industrial structure. It comes to the conclusions that: (a economic output, the provincial carbon productivity and energy structure are the most influential factors, which are consistent with China’s current actual policy; (b the distribution patterns of economic output, carbon productivity and energy structure in different regions have nothing to do with the Chinese traditional sense of the regional economic development patterns; (c considering the regional protectionism, regional actual situation need to be considered at the same time; (d in the study of the industrial structure, the contribution value of industry is the most prominent factor for China’s carbon productivity, while the industrial restructuring has not been done well enough.

  4. Enhanced production of green tide algal biomass through additional carbon supply.

    Directory of Open Access Journals (Sweden)

    Pedro H de Paula Silva

    Full Text Available Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2 enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3 (- as a carbon source for photosynthesis will benefit from CO2 enrichment. This study quantified the HCO3 (- affinity of three green tide algal species, Cladophora coelothrix, Cladophora patentiramea and Chaetomorpha linum, targeted for biomass and bioenergy production. Subsequently, we quantified productivity and carbon, nitrogen and ash content in response to CO2 enrichment. All three species had similar high pH compensation points (9.7-9.9, and grew at similar rates up to pH 9, demonstrating HCO3 (- utilization. Algal cultures enriched with CO2 as a carbon source had 30% more total Ci available, supplying twenty five times more CO2 than the control. This higher Ci significantly enhanced the productivity of Cladophora coelothrix (26%, Chaetomorpha linum (24% and to a lesser extent for Cladophora patentiramea (11%, compared to controls. We demonstrated that supplying carbon as CO2 can enhance the productivity of targeted green tide algal species under intensive culture, despite their clear ability to utilise HCO3 (-.

  5. Thermal Oxidation of Tail Gases from the Production of Oil-furnace Carbon Black

    Directory of Open Access Journals (Sweden)

    Bosak, Z.

    2009-01-01

    Full Text Available This paper describes the production technology of oil-furnace carbon black, as well as the selected solution for preventing the emissions of this process from contaminating the environment.The products of industrial oil-furnace carbon black production are different grades of carbon black and process tail gases. The qualitative composition of these tail gases during the production of oil-furnace carbon black are: carbon(IV oxide, carbon(II oxide, hydrogen, methane, hydrogen sulfide, nitrogen, oxygen, and water vapor.The quantitative composition and lower caloric value of process tail gases change depending on the type of feedstock used in the production, as well as the type of process. The lower caloric value of process tail gases is relatively small with values ranging between 1500 and 2300 kJ m–3.In the conventional production of oil-furnace carbon black, process tail gases purified from carbon black dust are freely released into the atmosphere untreated. In this manner, the process tail gases pollute the air in the town of Kutina, because their quantitative values are much higher than the prescribed emissions limits for hydrogen sulfide and carbon(II oxide. A logical solution for the prevention of such air pollution is combustion of the process tail gases, i. e. their thermal oxidation. For this purpose, a specially designed flare system has been developed. Consuming minimum amounts of natural gas needed for oxidation, the flare system is designed to combust low caloric process tail gases with 99 % efficiency. Thus, the toxic and flammable components of the tail gases (hydrogen sulfide, hydrogen, carbon(II oxide, methane and other trace hydrocarbons would be transformed into environmentally acceptable components (sulfur(IV oxide, water, carbon(IV oxide and nitrogen(IV oxide, which are in compliance with the emissions limit values prescribed by law.Proper operation of this flare system in the production of oil-furnace carbon black would solve

  6. Methane and carbon dioxide ratio in excreted air for quantification of the methane production from ruminants

    DEFF Research Database (Denmark)

    Madsen, Jørgen; Bjerg, Bjarne Schmidt; Hvelplund, Torben

    2010-01-01

    This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH4) production from animals by using the CH4 and carbon dioxide (CO2) concentrations in air near the animals combined with an estimation of the total CO2 production from information on intake of metab......This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH4) production from animals by using the CH4 and carbon dioxide (CO2) concentrations in air near the animals combined with an estimation of the total CO2 production from information on intake...

  7. Brief Analysis on the Production & Operation Situation of Chinese Carbon Black Industry in the First Half Year

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    At present, there are about 120 carbon black manufacturing enterprises in China with the production capacity of 3.41 million tons, accounting for 78% of the total production capacity of the country, in which there are 31 carbon black enterprises with the production capacity of over 50,000 tons. Compared with the international carbon black industry, our carbon black industry has a low intensification.

  8. An ingenious replica templated from the light trapping structure in butterfly wing scales

    Science.gov (United States)

    Han, Zhiwu; Niu, Shichao; Yang, Meng; Zhang, Junqiu; Yin, Wei; Ren, Luquan

    2013-08-01

    Although the physical mechanism of light trapping property of butterfly wings is well understood, it remains a challenge to create artificial replicas of these natural functional structures. Here, we synthesized a SiO2 inverse replica of a light trapping structure in butterfly wing scales using a method combining a sol-gel process and subsequent selective etching. First, the reflectance spectrum was taken to measure the reflectivity. Then, FESEM and TEM were used to observe the coupling structure of scales and the replicas. Afterwards, assisted by SEM and TEM data, 3D optimized models of the structures and fabrication process were generated by software. Finally, the parametric comparisons of the morphologies and structures between the original template and the inverse SiO2 replica were carefully conducted, and it was found that the original structures of bio-templates were well inherited by the structures of the inverse replica. This work would open up possibilities for an extensive study of mimicking novel bio-inspired functional materials, and the reported biomimetic technique confirms the feasibility of extending the functional structures in butterfly wings to particular optical devices in the field of space exploration, space equipment, photoelectrical devices and photo-induced sensors.Although the physical mechanism of light trapping property of butterfly wings is well understood, it remains a challenge to create artificial replicas of these natural functional structures. Here, we synthesized a SiO2 inverse replica of a light trapping structure in butterfly wing scales using a method combining a sol-gel process and subsequent selective etching. First, the reflectance spectrum was taken to measure the reflectivity. Then, FESEM and TEM were used to observe the coupling structure of scales and the replicas. Afterwards, assisted by SEM and TEM data, 3D optimized models of the structures and fabrication process were generated by software. Finally, the parametric

  9. Integrated carbon analysis of biomass production on fallow agricultural land and product substitution in Sweden - Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Dornburg, Veronika; Eggers, Thies; Gustavsson, Leif [Mid Sweden Univ., Oestersund (Sweden). Ecotechnology

    2006-07-15

    An important option in the Swedish context to reduce its net emissions of carbon dioxide (CO{sub 2}) is the increased use of biomass for energy and material substitution. On fallow agricultural land additional production of biomass would be possible. We analyse biomass production systems based on Norway spruce, hybrid poplar and willow hybrids and the use of this biomass to replace fossil energy and energy intensive material systems. The highest biomass production potential is for willow in southern Sweden. Fertilisation management of spruce could shorten the rotation lengths by about 17%. The fertilised production of Norway spruce with use of harvested timber for construction and use of remaining woody biomass for heat and power production gives the largest reductions of carbon emissions per hectare under the assumptions made. The use of willow for heat and power and of fertilised spruce for a wood product mix lead to the highest fossil primary energy savings in our scenarios. Spruce cultivations can achieve considerable carbon emission reductions in the long term, but willow and poplar might be a good option when fossil energy savings and carbon emission reductions should be achieved in the short term.

  10. Joint production of timber, carbon, and wildlife habitat in the Canadian boreal plains

    Energy Technology Data Exchange (ETDEWEB)

    McCarney, G.R.; Adamowicz, W.L. [Alberta Univ., Edmonton, AB (Canada). Dept. of Rural Economy; Armstrong, G.W. [Alberta Univ., Edmonton, AB (Canada). Dept. of Renewable Resources

    2008-06-15

    The relationships between forest carbon management, sustained timber yield, and the maintenance of wildlife habitats in the Canadian Boreal plain region were investigated. The aim of the study was to provide an estimation of the costs and challenges faced by forest managers in Canada's Boreal mixedwood region. The study used a model that previously analyzed the joint production of timber supplies and wildlife habitats using a natural disturbance model. A carbon budget model was used to separate biomass and dead organic matter carbon pools for individual forest cover types. An extensive marginal cost analysis of the production trade-offs between timber, carbon, and wildlife habitat was conducted. Results were used to demonstrate the potential for cost thresholds in timber supply and carbon sequestration. Thresholds were linked to switch-points in multiple use and specialized land management practices. Results showed that the optimal allocation of sequestered carbon across forest cover type differed with habitat constraints versus timber and carbon management alone. Results indicated that national policy discussions concerning carbon market regulations may wish to consider the potential for thresholds in production cost. Benefits of the management approach were influenced by ecological parameters, harvest flow regulations, and financial incentives for timber supply. 54 refs., 1 tab., 7 figs.

  11. Sustainable Production of Cannabinoids with Supercritical Carbon Dioxide Technologies

    NARCIS (Netherlands)

    Perrotin-Brunel, H.

    2011-01-01

    This thesis concerns the production of natural compounds from plant material for pharmaceutical and food applications. It describes the production (extraction and isolation) of cannabinoids, the active components present in cannabis. Many cannabinoids have medicinal properties but not all cannabinoi

  12. Production and characterization of activated carbon from a ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... activating it in high temperatures (800 - 1000°C) in an oxidizing environment. At this .... sample has displayed typical coal behavior. It has lost water content up ..... Adsorption of Copper and Cadmium Ions by Activated Carbon ...

  13. Production of carbon nanotubes by the magnetron DC sputtering method

    NARCIS (Netherlands)

    Antonenko, SV; Mal'tsev, SN

    2005-01-01

    Carbon films containing multiwall nanotubes were produced by the magnetron de sputtering method. A graphite disc with Y and Ni catalyst plates was used as a target. The structural and morphological properties of the films were investigated using a JEM 2000EXII transmission electron microscope. The f

  14. Carbon dioxide concentration in Mediterranean greenhouses : how much lost production?

    NARCIS (Netherlands)

    Stanghellini, C.; Incrocci, L.; Gazquez, J.C.; Dimauro, B.

    2008-01-01

    In the absence of artificial supply of carbon dioxide in the greenhouse environment, the CO2 absorbed in the process of photosynthesis must ultimately come from the external ambient through the ventilation openings. This requires that the CO2 concentration within the house must be lower than the ext

  15. Carbon pools and flux in U.S. forest products

    Science.gov (United States)

    Linda S. Heath; Richard A. Birdsey; Clark Row; Andrew J. Plantinga

    1996-01-01

    Increasing recognition that anthropogenic CO2 and other greenhouse gas emissions may effect climate change has prompted research studies on global carbon (C) budgets and international agreements for action. At the United Nations Conference on Environment and Development in 1992, world leaders and citizens gathered and initiated the Framework...

  16. Interannual stability of organic to inorganic carbon production on a coral atoll

    Science.gov (United States)

    Kwiatkowski, Lester; Albright, Rebecca; Hosfelt, Jessica; Nebuchina, Yana; Ninokawa, Aaron; Rivlin, Tanya; Sesboüé, Marine; Wolfe, Kennedy; Caldeira, Ken

    2016-04-01

    Ocean acidification has the potential to adversely affect marine calcifying organisms, with substantial ocean ecosystem impacts projected over the 21st century. Characterizing the in situ sensitivity of calcifying ecosystems to natural variability in carbonate chemistry may improve our understanding of the long-term impacts of ocean acidification. We explore the potential for intensive temporal sampling to isolate the influence of carbonate chemistry on community calcification rates of a coral reef and compare the ratio of organic to inorganic carbon production to previous studies at the same location. Even with intensive temporal sampling, community calcification displays only a weak dependence on carbonate chemistry variability. However, across three years of sampling, the ratio of organic to inorganic carbon production is highly consistent. Although further work is required to quantify the spatial variability associated with such ratios, this suggests that these measurements have the potential to indicate the response of coral reefs to ongoing disturbance, ocean acidification, and climate change.

  17. Microbial methane production associated with carbon steel corrosion in a Nigerian oil field

    Directory of Open Access Journals (Sweden)

    Jaspreet eMand

    2016-01-01

    Full Text Available Microbially influenced corrosion (MIC in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC.

  18. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Philip L. Biedler; Chong Chen; Dady Dadyburjor; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2005-04-13

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. A process has been developed which results in high quality binder pitch suitable for use in graphite electrodes or carbon anodes. A detailed description of the protocol is given by Clendenin. Briefly, aromatic heavy oils are hydro-treated under mild conditions in order to increase their ability to dissolve coal. An example of an aromatic heavy oil is Koppers Carbon Black Base (CBB) oil. CBB oil has been found to be an effective solvent and acceptably low cost (i.e., significantly below the market price for binder pitch, or about $280 per ton at the time of this writing). It is also possible to use solvents derived from hydrotreated coal and avoid reliance on coke oven recovery products completely if so desired.

  19. Microbial Methane Production Associated with Carbon Steel Corrosion in a Nigerian Oil Field.

    Science.gov (United States)

    Mand, Jaspreet; Park, Hyung S; Okoro, Chuma; Lomans, Bart P; Smith, Seun; Chiejina, Leo; Voordouw, Gerrit

    2015-01-01

    Microbially influenced corrosion (MIC) in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC.

  20. A Comparison of Carbon Footprint and Production Cost of Different Pasta Products Based on Whole Egg and Pea Flour

    Directory of Open Access Journals (Sweden)

    Antonia Nette

    2016-03-01

    Full Text Available Feed and food production are inter alia reasons for high greenhouse gas emissions. Greenhouse gas emissions could be reduced by the replacement of animal components with plant components in processed food products, such as pasta. The main components currently used for pasta are semolina, and water, as well as additional egg. The hypothesis of this paper is that the substitution of whole egg with plant-based ingredients, for example from peas, in such a product might lead to reduced greenhouse gas emissions (GHG and thus a reduced carbon footprint at economically reasonable costs. The costs and carbon footprints of two pasta types, produced with egg or pea protein, are calculated. Plant protein–based pasta products proved to cause 0.57 kg CO2 equivalents (CO2eq (31% per kg pasta less greenhouse gas emissions than animal-based pasta, while the cost of production increases by 10% to 3.00 €/kg pasta.

  1. Organic carbon production, mineralization and preservation on the Peruvian margin

    Directory of Open Access Journals (Sweden)

    A. W. Dale

    2014-09-01

    Full Text Available Carbon cycling in Peruvian margin sediments (11° S and 12° S was examined at 16 stations from 74 m on the inner shelf down to 1024 m water depth by means of in situ flux measurements, sedimentary geochemistry and modeling. Bottom water oxygen was below detection limit down to ca. 400 m and increased to 53 μM at the deepest station. Sediment accumulation rates and benthic dissolved inorganic carbon fluxes decreased rapidly with water depth. Particulate organic carbon (POC content was lowest on the inner shelf and at the deep oxygenated stations (< 5% and highest between 200 and 400 m in the oxygen minimum zone (OMZ, 15–20%. The organic carbon burial efficiency (CBE was unexpectedly low on the inner shelf (< 20% when compared to a global database, for reasons which may be linked to the frequent ventilation of the shelf by oceanographic anomalies. CBE at the deeper oxygenated sites was much higher than expected (max. 81%. Elsewhere, CBEs were mostly above the range expected for sediments underlying normal oxic bottom waters, with an average of 51 and 58% for the 11° S and 12° S transects, respectively. Organic carbon rain rates calculated from the benthic fluxes alluded to a very efficient mineralization of organic matter in the water column, with a Martin curve exponent typical of normal oxic waters (0.88 ± 0.09. Yet, mean POC burial rates were 2–5 times higher than the global average for continental margins. The observations at the Peruvian margin suggest that a lack of oxygen does not affect the degradation of organic matter in the water column but promotes the preservation of organic matter in marine sediments.

  2. Production of activated carbons from pyrolysis of waste tires impregnated with potassium hydroxide.

    Science.gov (United States)

    Teng, H; Lin, Y C; Hsu, L Y

    2000-11-01

    Activated carbons were produced from waste tires using a chemical activation method. The carbon production process consisted of potassium hydroxide (KOH) impregnation followed by pyrolysis in N2 at 600-900 degrees C for 0-2 hr. The activation method can produce carbons with a surface area (SA) and total pore volume as high as 470 m2/g and 0.57 cm3/g, respectively. The influence of different parameters during chemical activation, such as pyrolysis temperature, holding time, and KOH/tire ratio, on the carbon yield and the surface characteristics was explored, and the optimum preparation conditions were recommended. The pore volume of the resulting carbons generally increases with the extent of carbon gasified by KOH and its derivatives, whereas the SA increases with degree of gasification to reach a maximum value, and then decreases upon further gasification.

  3. Reduced carbon emission estimates from fossil fuel combustion and cement production in China

    Science.gov (United States)

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J.; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J.; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A.; Feng, Kuishuang; Peters, Glen P.; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-01

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = +/-7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

  4. Reduced carbon emission estimates from fossil fuel combustion and cement production in China.

    Science.gov (United States)

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A; Feng, Kuishuang; Peters, Glen P; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-20

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

  5. Carbon sequestration in the trees, products and soils of forest plantations: an analysis using UK examples.

    Science.gov (United States)

    Dewar, R C; Cannell, M G

    1992-07-01

    A carbon-flow model for managed forest plantations was used to estimate carbon storage in UK plantations differing in Yield Class (growth rate), thinning regime and species characteristics. Time-averaged, total carbon storage (at equilibrium) was generally in the range 40-80 Mg C ha(-1) in trees, 15-25 Mg C ha(-1) in above- and belowground litter, 70-90 Mg C ha(-1) in soil organic matter and 20-40 Mg C ha(-1) in wood products (assuming product lifetime equalled rotation length). The rate of carbon storage during the first rotation in most plantations was in the range 2-5 Mg C ha(-1) year(-1).A sensitivity analysis revealed the following processes to be both uncertain and critical: the fraction of total woody biomass in branches and roots; litter and soil organic matter decomposition rates; and rates of fine root turnover. Other variables, including the time to canopy closure and the possibility of accelerated decomposition after harvest, were less critical. The lifetime of wood products was not critical to total carbon storage because wood products formed only a modest fraction of the total.The average increase in total carbon storage in the tree-soil-product system per unit increase in Yield Class (m(3) ha(-1) year(-1)) for unthinned Picea sitchensis (Bong.) Carr. plantations was 5.6 Mg C ha(-1). Increasing the Yield Class from 6 to 24 m(3) ha(-1) year(-1) increased the rate of carbon storage in the first rotation from 2.5 to 5.6 Mg C ha(-1) year(-1) in unthinned plantations. Thinning reduced total carbon storage in P. sitchensis plantations by about 15%, and is likely to reduce carbon storage in all plantation types.If the objective is to store carbon rapidly in the short term and achieve high carbon storage in the long term, Populus plantations growing on fertile land (2.7 m spacing, 26-year rotations, Yield Class 12) were the best option examined. If the objective is to achieve high carbon storage in the medium term (50 years) without regard to the initial rate

  6. 77 FR 58512 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2012-09-21

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... conducting an administrative review of the countervailing duty (CVD) order on corrosion-resistant carbon... Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Notice of Extension of...

  7. 77 FR 44213 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea...

    Science.gov (United States)

    2012-07-27

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic... certain corrosion-resistant carbon steel flat products (``CORE'') from Germany and the Republic of Korea..., Director, Office 3, on ``Sunset Reviews of the Antidumping Duty Orders on Corrosion-Resistant Carbon Steel...

  8. 76 FR 54209 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2011-08-31

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... conducting an administrative review of the countervailing duty (CVD) order on corrosion-resistant carbon... CORE from Korea with regard to Dongbu and POSCO. See Corrosion-Resistant Carbon Steel Flat Products...

  9. 78 FR 16832 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Revocation...

    Science.gov (United States)

    2013-03-19

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic... corrosion-resistant carbon steel flat products (``CORE'') from Germany and the Republic of Korea (``Korea...-Year (``Sunset'') Review, 77 FR 85 (January 3, 2012). \\2\\ See Corrosion-Resistant Carbon Steel Flat...

  10. 78 FR 16247 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea; Final Results of...

    Science.gov (United States)

    2013-03-14

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... antidumping duty order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea... section entitled ``Final Results of Review.'' \\1\\ See Certain Corrosion-Resistant Carbon Steel Flat...

  11. 76 FR 77775 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-12-14

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea... countervailing duty order on corrosion-resistant carbon steel flat products from the Republic of Korea covering the period January 1, 2009, through December 31, 2009. See Corrosion-Resistant Carbon Steel Flat...

  12. 77 FR 13093 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2012-03-05

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... administrative review of the countervailing duty (``CVD'') order on corrosion-resistant carbon steel flat... Review'' below. \\1\\ See Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea...

  13. Short Term Electric Production Technology Switching Under Carbon Cap and Trade

    Directory of Open Access Journals (Sweden)

    Donald F. Larson

    2012-10-01

    Full Text Available This study examines fuel switching in electricity production following the introduction of the European Union’s Emissions Trading System (EU ETS for greenhouse gas emissions. A short-run restricted cost equation is estimated with carbon permits, high-carbon fuels, and low carbon fuels as variable inputs. Shadow values and substitution elasticities for carbon-free energy resources from nuclear, hydroelectric and renewable sources are imputed from the cost equation. The empirical analysis examines 12 European countries using monthly data on fuel use, prices, and electricity generation during the first phase of the European Emissions Trading System. Despite low emission permit prices, this study finds statistically significant substitution between fossil fuels and carbon free sources of energy for electric power production. Significant substitution between fossil fuels and nuclear energy also was found. Still, while 18 of the 20 substitution elasticities are statistically significant, they are all less than unity, consistent with limited substitution. Overall, these results suggest that prices for carbon emission permits relative to prices for carbon and carbon free sources of energy do matter but that electric power producers have limited operational flexibility in the short-run to satisfy greenhouse gas emission limits.

  14. Economic Evaluations for the Carbon Dioxide-involved Production of High-value Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Hyun; Lee, Dong Woog; Jang, Se Gyu; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo [KEPCO Research Institute, Daejon (Korea, Republic of); Choi, Jong Shin [Korea East-West Power Co. LTD, Seoul (Korea, Republic of)

    2014-06-15

    Economic evaluation of the manufacturing technology of high-value chemicals through the carbonation reaction of carbon dioxide contained in the flue gas was performed, and analysis of the IRR (Internal Rate of Return) and whole profit along the production plan of the final product was conducted. Through a carbonation reaction with sodium hydroxide that is generated from electrolysis and by using carbon dioxide in the combustion gas that is generated in the power plant, it is possible to get a high value products such as sodium bicarbonate compound and also to reduce the carbon dioxide emission simultaneously. The IRR (Internal Rate of Return) and NPV (Net Present Value) methods were used for the economic evaluation of the process which could handle carbon dioxide of 100 tons per day in the period of the 20 years of plant operation. The results of economic evaluation showed that the IRR of baseline case of technology was 67.2% and the profit that obtained during the whole operation period (20 years) was 346,922 million won based on NPV value. When considering ETS due to the emissions trading enforcement that will be activated in 2015, the NPV was improved to a 6,000 million won. Based on this results, it could be concluded that this CO2 carbonation technology is an cost-effective technology option for the reduction of greenhouse gas.

  15. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; R. Michael Bergen; Stephen P. Carpenter; Dady Dadyburjor; Manoj Katakdaunde; Liviu Magean; Alfred H. Stiller; W. Morgan Summers; John W. Zondlo

    2006-05-12

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, coking and composite fabrication continued using coal-derived samples. These samples were tested in direct carbon fuel cells. Methodology was refined for determining the aromatic character of hydro treated liquid, based on Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR). Tests at GrafTech International showed that binder pitches produced using the WVU solvent extraction protocol can result in acceptable graphite electrodes for use in arc furnaces. These tests were made at the pilot scale.

  16. Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

    Directory of Open Access Journals (Sweden)

    Burmistrz Piotr

    2016-01-01

    Full Text Available The analysis of Carbon Footprint (CF for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ. The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA.

  17. Characteristics of lignin precipitated with organic acids as a source for valorisation carbon products

    CSIR Research Space (South Africa)

    Namane, M

    2015-06-01

    Full Text Available biomass derived industries. It’s richness in carbon appropriates it for far more than the industry is currently utilizing it for, therefore production of high value products (and energy) from lignin could be a significant step towards appreciating...

  18. Life Cycle Assessment as a Tool to Enhance the Environmental Performanceof Carbon Nanotube Products: A Review

    Science.gov (United States)

    The importance of evaluating the environmental performance of emerging carbon nanotube (CNT) products from a life cycle perspective is emphasized in this work. Design, development and deployment of CNT products offer many potential benefits to society, but not without negative im...

  19. Occupational Exposure to Multi-Walled Carbon Nanotubes During Commercial Production Synthesis and Handling

    NARCIS (Netherlands)

    Kuijpers, Eelco; Bekker, Cindy; Fransman, Wouter; Brouwer, Derk; Tromp, Peter; Vlaanderen, Jelle; Godderis, Lode; Hoet, Peter; Lan, Qing; Silverman, Debra; Vermeulen, Roel; Pronk, Anjoeka

    2016-01-01

    The world-wide production of carbon nanotubes (CNTs) has increased substantially in the last decade, leading to occupational exposures. There is a paucity of exposure data of workers involved in the commercial production of CNTs. The goals of this study were to assess personal exposure to multi-wall

  20. Natural carbon isotopes used to study methane consumption and production in soil

    DEFF Research Database (Denmark)

    Ambus, Per; Andersen, Bertel Lohmann; Kemner, Marianne;

    2002-01-01

    Changes in the isotopic composition of carbon can be used to reveal simultaneous occurrence of methane production and oxidation in soil. The method is conducted in laboratory jar experiments as well as in the field by using flux chambers. Simultaneous occurrence of production and oxidation...

  1. Life Cycle Assessment as a Tool to Enhance the Environmental Performanceof Carbon Nanotube Products: A Review

    Science.gov (United States)

    The importance of evaluating the environmental performance of emerging carbon nanotube (CNT) products from a life cycle perspective is emphasized in this work. Design, development and deployment of CNT products offer many potential benefits to society, but not without negative im...

  2. Carbon-10: Example of cyclotron production of positron emitters as an open research field

    DEFF Research Database (Denmark)

    Alves, F.; Lima, J.J.P.; Nickles, R.J.

    2007-01-01

    This paper supports the thesis that significant improvement of PET output response to clinical questions can be achieved by innovation in radionuclide production. Moreover, that development can be performed with the resources available at a clinical centre. Carbon-10 production parameters studies...

  3. Electrobiocommodities: powering microbial production of fuels and commodity chemicals from carbon dioxide with electricity

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, DR; Nevin, KP

    2013-06-01

    Electricity can be an energy source for microbially catalyzed production of fuels and other organic commodities from carbon dioxide. These electrobiocommodities (E-BCs) can be produced directly via electrode-to-microbe electron transfer or indirectly with electrochemically generated electron donors such as H-2 or formate. Producing E-BCs may be a more efficient and environmentally sustainable strategy for converting solar energy to biocommodities than approaches that rely on biological photosynthesis. A diversity of microbial physiologies could potentially be adapted for E-BC production, but to date acetogenic microorganisms are the only organisms shown to covert electrically generated low potential electrons and carbon dioxide into multi-carbon organic products with high recovery of electrons in product. Substantial research and development will be required for E-BC commercialization.

  4. Improving farming practices reduces the carbon footprint of spring wheat production.

    Science.gov (United States)

    Gan, Yantai; Liang, Chang; Chai, Qiang; Lemke, Reynald L; Campbell, Con A; Zentner, Robert P

    2014-11-18

    Wheat is one of the world's most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging -256 kg CO2 eq ha(-1) per year. For each kg of wheat grain produced, a net 0.027-0.377 kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production.

  5. DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliot B. Kennel; Philip L. Biedler; Chong Chen; Dady Dadyburjor; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2005-06-23

    The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. There are a number of parameters which are important for the production of acceptable cokes, including purity, structure, density, electrical resistivity, thermal conductivity etc. From the standpoint of a manufacturer of graphite electrodes such as GrafTech, one of the most important parameters is coefficient of thermal expansion (CTE). Because GrafTech material is usually fully graphitized (i.e., heat treated at 3100 C), very high purity is automatically achieved. The degree of graphitization controls properties such as CTE, electrical resistivity, thermal conductivity, and density. Thus it is usually possible to correlate these properties using a single parameter. CTE has proven to be a useful index for the quality of coke. Pure graphite actually has a slightly negative coefficient of thermal expansion, whereas more disordered carbon has a positive coefficient.

  6. Assessment of hydro/oleophobicity for shark skin replica with riblets.

    Science.gov (United States)

    Kim, Tae Wan

    2014-10-01

    The shark skin has a unique skin structure which enables the shark to swim faster and more efficiently due to an intriguing three-dimensional rib pattern. Shark skin has also known as having functional performances such as self cleaning and anti-fouling as well as excellent drag reduction due to a hierarchical structure built up by micro grooves and nano-long chain mucus drag reduction interface around the shark body. In this study, the wetting properties for the biomimetic surfaces that replicate shark skin are assessed. First of all, the shark skin replicas are obtained using the micro molding technique directly from a shark skin template. The quantitative replication precision of the shark skin replicas is evaluated comparing with the geometry of shark skin template using 3D and 2D surface profiles are measured. Then contact angles in the conditions of solid-air-water, solid-air-oil and solid-water-oil interfaces are evaluated for shark skin replicas. The effect of Teflon coating on the wetting properties of shark skin replicas is also observed. The results show the shark skin replica by the micro molding technique gives better effect on the wetting performance, and the micro riblets on shark skin improve the wettability feature.

  7. Impact of gas products around the anode on the performance of a direct carbon fuel cell using a carbon/carbonate slurry

    Science.gov (United States)

    Watanabe, Hirotatsu; Umehara, Daisuke; Hanamura, Katsunori

    2016-10-01

    This paper investigates the impact of gas products around the anode on cell performance via an in situ observation. In a direct carbon fuel cell used this study, the anode is inserted into the carbon/carbonate slurry. The current-voltage (I-V) curves are measured before and after a long discharge in the constant current discharge mode. An in situ observation shows that the anode is almost completely covered by gas bubbles when the voltage becomes nearly 0 V in the constant current discharge at 40 mA/cm2; this indicates that gas products such as CO2 prevent the carbon particles and ions from reaching the anode. Meanwhile, the long discharge at 20 mA/cm2 is achieved for 30 min, even though the anode is covered by the CO2 bubbles at 15 min. The I-V curves at 1 min after the termination of the long discharge at 20 mA/cm2 are lower than those prior to the long discharge. The overpotential significantly increases at higher current densities, where mass transport becomes the limiting process. The cell performance is significantly influenced by the gas products around the anode.

  8. Carbonic anhydrase in Escherichia coli. A product of the cyn operon.

    Science.gov (United States)

    Guilloton, M B; Korte, J J; Lamblin, A F; Fuchs, J A; Anderson, P M

    1992-02-25

    The product of the cynT gene of the cyn operon in Escherichia coli has been identified as a carbonic anhydrase. The cyn operon also includes the gene cynS, encoding the enzyme cyanase. Cyanase catalyzes the reaction of cyanate with bicarbonate to give ammonia and carbon dioxide. The carbonic anhydrase was isolated from an Escherichia coli strain overexpressing the cynT gene and characterized. The purified enzyme was shown to contain 1 Zn2+/subunit (24 kDa) and was found to behave as an oligomer in solution; the presence of bicarbonate resulted in partial dissociation of the oligomeric enzyme. The kinetic properties of the enzyme are similar to those of carbonic anhydrases from other species, including inhibition by sulfonamides and cyanate. The amino acid sequence shows a high degree of identity with the sequences of two plant carbonic anhydrases. but not with animal and algal carbonic anhydrases. Since carbon dioxide formed in the bicarbonate-dependent decomposition of cyanate diffuses out of the cell faster than it would be hydrated to bicarbonate, the apparent function of the induced carbonic anhydrase is to catalyze hydration of carbon dioxide and thus prevent depletion of cellular bicarbonate.

  9. Water availability limits tree productivity, carbon stocks, and carbon residence time in mature forests across the western US

    Science.gov (United States)

    Berner, Logan T.; Law, Beverly E.; Hudiburg, Tara W.

    2017-01-01

    Water availability constrains the structure and function of terrestrial ecosystems and is projected to change in many parts of the world over the coming century. We quantified the response of tree net primary productivity (NPP), live biomass (BIO), and mean carbon residence time (CRT = BIO / NPP) to spatial variation in water availability in the western US. We used forest inventory measurements from 1953 mature stands (> 100 years) in Washington, Oregon, and California (WAORCA) along with satellite and climate data sets covering the western US. We summarized forest structure and function in both domains along a 400 cm yr-1 hydrologic gradient, quantified with a climate moisture index (CMI) based on the difference between precipitation and reference evapotranspiration summed over the water year (October-September) and then averaged annually from 1985 to 2014 (CMIwy). Median NPP, BIO, and CRT computed at 10 cm yr-1 intervals along the CMIwy gradient increased monotonically with increasing CMIwy across both WAORCA (rs = 0.93-0.96, p changes over the western US, though these data sets tended to plateau in the wettest areas, suggesting that additional efforts are needed to better quantify NPP and BIO from satellites in high-productivity, high-biomass forests. Our results illustrate that long-term average water availability is a key environmental constraint on tree productivity, carbon storage, and carbon residence time in mature forests across the western US, underscoring the need to assess potential ecosystem response to projected warming and drying over the coming century.

  10. Propellant and Terrestrial Fuel Production from Atmospheric Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Build and test in a relevant environment a Mars propellant production plant of an appropriate scale for an initial demonstration on Mars. It will produce sufficient...

  11. Greater soil carbon stocks and faster turnover rates with increasing agricultural productivity

    Science.gov (United States)

    Sanderman, Jonathan; Creamer, Courtney; Baisden, W. Troy; Farrell, Mark; Fallon, Stewart

    2017-01-01

    Devising agricultural management schemes that enhance food security and soil carbon levels is a high priority for many nations. However, the coupling between agricultural productivity, soil carbon stocks and organic matter turnover rates is still unclear. Archived soil samples from four decades of a long-term crop rotation trial were analyzed for soil organic matter (SOM) cycling-relevant properties: C and N content, bulk composition by nuclear magnetic resonance (NMR) spectroscopy, amino sugar content, short-term C bioavailability assays, and long-term C turnover rates by modeling the incorporation of the bomb spike in atmospheric 14C into the soil. After > 40 years under consistent management, topsoil carbon stocks ranged from 14 to 33 Mg C ha-1 and were linearly related to the mean productivity of each treatment. Measurements of SOM composition demonstrated increasing amounts of plant- and microbially derived SOM along the productivity gradient. Under two modeling scenarios, radiocarbon data indicated overall SOM turnover time decreased from 40 to 13 years with increasing productivity - twice the rate of decline predicted from simple steady-state models or static three-pool decay rates of measured C pool distributions. Similarly, the half-life of synthetic root exudates decreased from 30.4 to 21.5 h with increasing productivity, indicating accelerated microbial activity. These findings suggest that there is a direct feedback between accelerated biological activity, carbon cycling rates and rates of carbon stabilization with important implications for how SOM dynamics are represented in models.

  12. Low Carbon-Oriented Optimal Reliability Design with Interval Product Failure Analysis and Grey Correlation Analysis

    Directory of Open Access Journals (Sweden)

    Yixiong Feng

    2017-03-01

    Full Text Available The problem of large amounts of carbon emissions causes wide concern across the world, and it has become a serious threat to the sustainable development of the manufacturing industry. The intensive research into technologies and methodologies for green product design has significant theoretical meaning and practical value in reducing the emissions of the manufacturing industry. Therefore, a low carbon-oriented product reliability optimal design model is proposed in this paper: (1 The related expert evaluation information was prepared in interval numbers; (2 An improved product failure analysis considering the uncertain carbon emissions of the subsystem was performed to obtain the subsystem weight taking the carbon emissions into consideration. The interval grey correlation analysis was conducted to obtain the subsystem weight taking the uncertain correlations inside the product into consideration. Using the above two kinds of subsystem weights and different caution indicators of the decision maker, a series of product reliability design schemes is available; (3 The interval-valued intuitionistic fuzzy sets (IVIFSs were employed to select the optimal reliability and optimal design scheme based on three attributes, namely, low carbon, correlation and functions, and economic cost. The case study of a vertical CNC lathe proves the superiority and rationality of the proposed method.

  13. Production of O/1S/ from photodissociation of carbon dioxide.

    Science.gov (United States)

    Lawrence, G. M.

    1972-01-01

    The production efficiency was measured with the aid of a method based on the detection of the OI (5577 A) 'green' line. A sodium salicylate screen was used to monitor the intensity of the photons. Measurements at each of several individual wavelengths are conducted. The relative production efficiencies are shown in a graph. The absolute scale for the efficiency was determined in essentially the same way as in the Cameron band work reported by Lawrence (1972).

  14. Utilization of compressed natural gas for the production of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Kim-Yang Lee; Wei-Ming Yeoh; Siang-Piao Chai; Abdul Rahman Mohamed

    2012-01-01

    The present work aims at utilizing compressed natural gas (CNG) as carbon source for the synthesis of carbon nanotubes (CNTs) over CoO-MoO/Al2O3 catalyst via catalytic chemical vapor deposition (CCVD) method.The as-produced carbonaceous product was characterized by thermal gravimetric analyzer (TGA),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and Raman spectroscopy.The experimental finding shows that CNTs were successfully produced from CNG while carbon nanofibers (CNFs) were formed as the side products.In addition,the catalytic activity and lifetime were found sustained and prolonged,as compared with using high purity methane as carbon source.The present study suggests an alternative route which can effectively produce CNTs and CNFs using low cost CNG.

  15. Renewable phenols production by catalytic microwave pyrolysis of Douglas fir sawdust pellets with activated carbon catalysts.

    Science.gov (United States)

    Bu, Quan; Lei, Hanwu; Wang, Lu; Wei, Yi; Zhu, Lei; Liu, Yupeng; Liang, Jing; Tang, Juming

    2013-08-01

    The effects of different activated carbon (AC) catalysts based on various carbon sources on products yield and chemical compositions of upgraded pyrolysis oils were investigated using microwave pyrolysis of Douglas fir sawdust pellets. Results showed that high amounts of phenols were obtained (74.61% and 74.77% in the upgraded bio-oils by DARCO MRX (wood based) and DARCO 830 (lignite coal based) activated carbons, respectively). The catalysts recycling test of the selected catalysts indicated that the carbon catalysts can be reused for at least 3-4 times and produced high concentrations of phenol and phenolic compounds. The chemical reaction mechanism for phenolics production during microwave pyrolysis of biomass was analyzed.

  16. Solar-Driven Hydrogen Peroxide Production Using Polymer-Supported Carbon Dots as Heterogeneous Catalyst

    Science.gov (United States)

    Gogoi, Satyabrat; Karak, Niranjan

    2017-10-01

    Safe, sustainable, and green production of hydrogen peroxide is an exciting proposition due to the role of hydrogen peroxide as a green oxidant and energy carrier for fuel cells. The current work reports the development of carbon dot-impregnated waterborne hyperbranched polyurethane as a heterogeneous photo-catalyst for solar-driven production of hydrogen peroxide. The results reveal that the carbon dots possess a suitable band-gap of 2.98 eV, which facilitates effective splitting of both water and ethanol under solar irradiation. Inclusion of the carbon dots within the eco-friendly polymeric material ensures their catalytic activity and also provides a facile route for easy catalyst separation, especially from a solubilizing medium. The overall process was performed in accordance with the principles of green chemistry using bio-based precursors and aqueous medium. This work highlights the potential of carbon dots as an effective photo-catalyst.

  17. The NOAA Carbon America Program A Focus on Products for Decision- Support

    Science.gov (United States)

    Butler, J. H.; Hofmann, D. J.; Tans, P. P.; Peters, W.; Andrews, A. E.; Sweeny, C.; Montzka, S. A.

    2006-12-01

    If society is to manage or reduce carbon emissions in the future, reliable and accurate information on atmospheric carbon dioxide levels for verification of emission reductions will be needed on local, regional, and global scales. The current global carbon dioxide observing network operated by NOAA/ESRL provides a foundation for monitoring and understanding carbon dioxide. For example, atmospheric measurements in Europe suggest that emissions inventories of methane are substantial underestimates. An expanded U.S. Carbon Cycle Atmospheric Observing System is being implemented. Carbon America will consist of approximately 24 aircraft and 12 tall towers obtaining concentrations of carbon gases and other trace species. This observing system needs to be capable of quantitative attribution of all major contributors to the carbon budget of the continent, both manmade and natural. Successful mitigation strategies need independent and credible assessments of their efficacy. Managing carbon emissions will require the involvement of industry, financial markets, and governments at all levels. Without good information, governments will be slow to act, private investments will likely be less than optimal, and financial markets will not develop as they might need to. The atmospheric data and the methods used to derive sources and sinks will be fully open and available in up-to-date form to scientists, the general public, and policymakers. This presentation will provide an overview of NOAA`s role in the North American Carbon Program, our current accomplishments, our plans for the future network, and the currently expected products, services, and information that derive from these and other associated studies. Today's products, while useful, will be eclipsed by those of tomorrow, which will focus heavily on regional emissions expressed on seasonal or shorter time-scales, and will provide needed information for improved predictions in the future.

  18. Production of Carbon Nanofibers Using a CVD Method with Lithium Fluoride as a Supported Cobalt Catalyst

    Directory of Open Access Journals (Sweden)

    S. A. Manafi

    2008-02-01

    Full Text Available Carbon nanofibers (CNFs have been synthesized in high yield (>70% by catalytic chemical vapor deposition (CCVD on Co/LiF catalyst using acetylene as carbon source. A novel catalyst support (LiF is reported for the first time as an alternative for large-scale production of carbon nanofibers while purification process of nanofibers is easier. In our experiment, the sealed furnace was heated at 700∘C for 0.5 hour (the heating rate was 10∘C/min and then cooled to room temperature in the furnace naturally. Catalytic chemical vapor deposition is of interest for fundamental understanding and improvement of commercial synthesis of carbon nanofibers (CNFs. The obtained sample was sequentially washed with ethanol, dilutes acid, and distilled water to remove residual impurities, amorphous carbon materials, and remaining of catalyst, and then dried at 110∘C for 24 hours. The combined physical characterization through several techniques, such as high-resolution transmission electron microscope (TEM, scanning electron microscope (SEM, thermogarvimetric analysis (TGA, and zeta-sizer and Raman spectroscopy, allows determining the geometric characteristic and the microstructure of individual carbon nanofibers. Catalytic chemical vapor deposition is of interest for fundamental understanding and improvement of commercial synthesis of carbon nanofibers (CNFs. As a matter of fact, the method of CCVD guarantees the production of CNFs for different applications.

  19. Biorefineries of carbon dioxide: From carbon capture and storage (CCS) to bioenergies production.

    Science.gov (United States)

    Cheah, Wai Yan; Ling, Tau Chuan; Juan, Joon Ching; Lee, Duu-Jong; Chang, Jo-Shu; Show, Pau Loke

    2016-09-01

    Greenhouse gas emissions have several adverse environmental effects, like pollution and climate change. Currently applied carbon capture and storage (CCS) methods are not cost effective and have not been proven safe for long term sequestration. Another attractive approach is CO2 valorization, whereby CO2 can be captured in the form of biomass via photosynthesis and is subsequently converted into various form of bioenergy. This article summarizes the current carbon sequestration and utilization technologies, while emphasizing the value of bioconversion of CO2. In particular, CO2 sequestration by terrestrial plants, microalgae and other microorganisms are discussed. Prospects and challenges for CO2 conversion are addressed. The aim of this review is to provide comprehensive knowledge and updated information on the current advances in biological CO2 sequestration and valorization, which are essential if this approach is to achieve environmental sustainability and economic feasibility.

  20. Seagrass productivity: the effect of light on carbon uptake

    Energy Technology Data Exchange (ETDEWEB)

    Williams, S.L.; McRoy, C.P.

    1982-08-01

    Productivity, as estimated by /sup 14/C uptake, was determined as a function of irradiance for six North American seagrasses (Thalassia testudinum Banks ex. Koenig, Syringodium filiforme Kuetz, Halodule wrightii Aschers., Halophila engelmanni Aschers., Phyllospadix scouleri Hook and Ruppia maritima L.s.l.) from temperature, subtropical and tropical environments. Light versus productivity curves were typical of those of aquatic plants. Seagrasses achieved high rates of uptake (up to 17.31 mg C (g dry)-1 h-1) and exhibited high saturation irradiances (greater than or equal to 40% surface irradiance). Within each environment half-saturation and saturation irradiances were similar, indicating no competition for light in the production systems of the various species. Between environments maximum productivity and saturation irradiances changed as a function of the differing irradiance. When rates were normalized for ambient irradiance, there were no differences in maximum rates, except for plants from Texas. In the subtropics and tropics where several species co-exist in the same seagrass bed, two types of responses occurred, corresponding to climax versus colonizer species. The difference in the responses appeared in the initial and maximum rates and in sensitivity to high irradiance. Productivity of seagrasses can be estimated, with certain limitations, from light measurements using the equations of Michaelis-Menten and Steele. (Refs. 35).

  1. Study of particle production in hadron-nucleus interactions for neutrino experiments

    CERN Document Server

    Palczewski, Tomasz Jan

    The dissertation presents a study of hadron product ion in the NA61/SHINE large acceptance spectrometer at CERN SPS. The differential cross se ctions were obtained for the production of negatively charged pions, neutral Kaons, and Lam bdas from the proton-Carbon interactions at 31 GeV/c. Methods of particle yields extraction from proton Carbon interactions were developed. An analysis chain of global correction m ethod (h- method) was established for the thin carbon target and as well for T2K replica targ et and compared to the results obtained with full particle identification. The h- method permits to cover larger phase space region not otherwise accessible. In addition, a full chain of V 0 analysis was prepared to obtain neutral Kaon and Lambda results in polar angle and momentum variables (p, θ ). Results on the differential production cross sections and mean mul tiplicities in production processes for negatively charge...

  2. Method for production of polymer and carbon nanofibers from water-soluble polymers.

    Science.gov (United States)

    Spender, Jonathan; Demers, Alexander L; Xie, Xinfeng; Cline, Amos E; Earle, M Alden; Ellis, Lucas D; Neivandt, David J

    2012-07-11

    Nanometer scale carbon fibers (carbon nanofibers) are of great interest to scientists and engineers in fields such as materials science, composite production, and energy storage due to their unique chemical, physical, and mechanical properties. Precursors currently used for production of carbon nanofibers are primarily from nonrenewable resources. Lignin is a renewable natural polymer existing in all high-level plants that is a byproduct of the papermaking process and a potential feedstock for carbon nanofiber production. The work presented here demonstrates a process involving the rapid freezing of an aqueous lignin solution, followed by sublimation of the resultant ice, to form a uniform network comprised of individual interconnected lignin nanofibers. Carbonization of the lignin nanofibers yields a similarly structured carbon nanofiber network. The methodology is not specific to lignin; nanofibers of other water-soluble polymers have been successfully produced. This nanoscale fibrous morphology has not been observed in traditional cryogel processes, due to the relatively slower freezing rates employed compared to those achieved in this study.

  3. Production of long chain alkyl esters from carbon dioxide and electricity by a two-stage bacterial process

    DEFF Research Database (Denmark)

    Lehtinen, Tapio; Efimova, Elena; Tremblay, Pier-Luc

    2017-01-01

    Microbial electrosynthesis (MES) is a promising technology for the reduction of carbon dioxide into value-added multicarbon molecules. In order to broaden the product profile of MES processes, we developed a two-stage process for microbial conversion of carbon dioxide and electricity into long...... in an aerobic bioprocess. In this proof-of-principle study, we demonstrate for the first time the bacterial production of long alkyl esters (wax esters) from carbon dioxide and electricity as the sole sources of carbon and energy. The process holds potential for the efficient production of carbon...

  4. Eroding forest carbon sinks following thinning for combined fire prevention and bioenergy production

    Science.gov (United States)

    Hudiburg, T. W.; Law, B. E.; Luyssaert, S.

    2010-12-01

    Temperate forest annual net uptake of CO2 from the atmosphere is equivalent to ~16% of the annual fossil fuel emissions in the United States. Mitigation strategies to reduce emissions of carbon dioxide have lead to investigation of alternative sources of energy including forest biomass. The prospect of forest derived bioenergy has led to implementation of new forest management strategies based on the assumption that they will reduce total CO2 emissions to the atmosphere by simultaneously reducing the risk of wildfire and substituting for fossil fuels. Using Forest Inventory Analysis (FIA) plot data, regional supplemental plot data, and remote sensing products we determined the carbon stocks and fluxes of West Coast forests under current and proposed management scenarios for a 20 year treatment period. Varying biofuels thinning treatments designed to meet multiple objectives emphasizing fire prevention, economic gain, or energy production were applied to determine the resulting net carbon balance and bioenergy potential. Contrary to the management objectives, we find that increased removals result in substantial decreases in forest carbon stocks and Net Biome Production (NBP) and increased emissions. Thinning forests for energy production is not carbon neutral. Emissions are estimated to increase over the 20-year period because preventive thinning removals exceed the CO2 that would have been emitted due to wildfires, fossil fuel inputs are required for harvest and manufacturing, and use of woody biomass in short-lived products emits large quantities of CO2 to the atmosphere. It has the net effect of releasing otherwise sequestered carbon to the atmosphere, which may effectively reduce ongoing carbon uptake by forests and as a result, increase net greenhouse gas emissions, undermining the objective of greenhouse gas reductions over the next several decades.

  5. Laser ablation process for single-walled carbon nanotube production

    Science.gov (United States)

    Arepalli, Sivaram

    2004-01-01

    Different types of lasers are now routinely used to prepare single-walled carbon nanotubes. The original method developed by researchers at Rice University used a "double-pulse laser oven" process. Several researchers have used variations of the lasers to include one-laser pulse (green or infrared), different pulse widths (ns to micros as well as continuous wave), and different laser wavelengths (e.g., CO2, or free electron lasers in the near to far infrared). Some of these variations are tried with different combinations and concentrations of metal catalysts, buffer gases (e.g., helium), oven temperatures, flow conditions, and even different porosities of the graphite targets. This article is an attempt to cover all these variations and their relative merits. Possible growth mechanisms under these different conditions will also be discussed.

  6. Entropy generation in Gaussian quantum transformations: applying the replica method to continuous-variable quantum information theory

    Science.gov (United States)

    Gagatsos, Christos N.; Karanikas, Alexandros I.; Kordas, Georgios; Cerf, Nicolas J.

    2016-02-01

    In spite of their simple description in terms of rotations or symplectic transformations in phase space, quadratic Hamiltonians such as those modelling the most common Gaussian operations on bosonic modes remain poorly understood in terms of entropy production. For instance, determining the quantum entropy generated by a Bogoliubov transformation is notably a hard problem, with generally no known analytical solution, while it is vital to the characterisation of quantum communication via bosonic channels. Here we overcome this difficulty by adapting the replica method, a tool borrowed from statistical physics and quantum field theory. We exhibit a first application of this method to continuous-variable quantum information theory, where it enables accessing entropies in an optical parametric amplifier. As an illustration, we determine the entropy generated by amplifying a binary superposition of the vacuum and a Fock state, which yields a surprisingly simple, yet unknown analytical expression.

  7. Acceleration of Lateral Equilibration in Mixed Lipid Bilayers Using Replica Exchange with Solute Tempering.

    Science.gov (United States)

    Huang, Kun; García, Angel E

    2014-10-14

    The lateral heterogeneity of cellular membranes plays an important role in many biological functions such as signaling and regulating membrane proteins. This heterogeneity can result from preferential interactions between membrane components or interactions with membrane proteins. One major difficulty in molecular dynamics simulations aimed at studying the membrane heterogeneity is that lipids diffuse slowly and collectively in bilayers, and therefore, it is difficult to reach equilibrium in lateral organization in bilayer mixtures. Here, we propose the use of the replica exchange with solute tempering (REST) approach to accelerate lateral relaxation in heterogeneous bilayers. REST is based on the replica exchange method but tempers only the solute, leaving the temperature of the solvent fixed. Since the number of replicas in REST scales approximately only with the degrees of freedom in the solute, REST enables us to enhance the configuration sampling of lipid bilayers with fewer replicas, in comparison with the temperature replica exchange molecular dynamics simulation (T-REMD) where the number of replicas scales with the degrees of freedom of the entire system. We apply the REST method to a cholesterol and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayer mixture and find that the lateral distribution functions of all molecular pair types converge much faster than in the standard MD simulation. The relative diffusion rate between molecules in REST is, on average, an order of magnitude faster than in the standard MD simulation. Although REST was initially proposed to study protein folding and its efficiency in protein folding is still under debate, we find a unique application of REST to accelerate lateral equilibration in mixed lipid membranes and suggest a promising way to probe membrane lateral heterogeneity through molecular dynamics simulation.

  8. Resource Efficiency and Carbon Footprint Minimization in Manufacture of Plastic Products

    Directory of Open Access Journals (Sweden)

    K. Sabaliauskaitė

    2014-03-01

    Full Text Available Efficient resource management, waste prevention, as well as renewable resource consumption promote sustainable production and lower greenhouse gas emissions to the environment when manufacturing plastic products.The paper presents the analysis of the efficiency of resources and the potential of carbon footprint minimization in manufacture of plastic products by means of implementation of wood-plastic composite (WPC production. The analysis was performed using life cycle assessment and material flow analysis methodology. To devise the solution for better management of resources and minimization of carbon footprint, the environmental impacts of polyvinyl chloride (PVC and WPC wall panels through their life cycle were assessed, as well as the detailed material flow analyses of the PVC and WPC in production stages were carried out.The life cycle assessment has revealed that carbon footprints throughout life cycle of 1 kg of WPC wall panel are 37 % lower than those of the same weight of PVC wall panel product. Both products have a major impact on the environment during their production phase, while during this phase WPC wall panel has 35 % smaller carbon footprint and even 47 % smaller during disposal stages than those of the PVC wall panel.The results of material flow analysis have shown that recycling and reuse of production spoilage reduce the need of PVC secondary resources for PVC panels and primary WPC resources for WPC panel production.For better resource efficiency, the conceptual model of material flow management has been proposed. As WPC products are made of primary WPC granules, which are imported from abroad, the model suggests to produce the WPC granules at the company using collected PVC secondary materials (PVC stocks. It would lower environmental costs and environmental impact, increase the efficiency of resources, and diminish dependence on suppliers.DOI: http://dx.doi.org/10.5755/j01.erem.67.1.6587

  9. Resource Efficiency and Carbon Footprint Minimization in Manufacture of Plastic Products

    Directory of Open Access Journals (Sweden)

    Kamilė Sabaliauskaitė

    2014-04-01

    Full Text Available Efficient resource management, waste prevention, as well as renewable resource consumption promote sustainable production and lower greenhouse gas emissions to the environment when manufacturing plastic products. The paper presents the analysis of the efficiency of resources and the potential of carbon footprint minimization in manufacture of plastic products by means of implementation of wood-plastic composite (WPC production. The analysis was performed using life cycle assessment and material flow analysis methodology. To devise the solution for better management of resources and minimization of carbon footprint, the environmental impacts of polyvinyl chloride (PVC and WPC wall panels through their life cycle were assessed, as well as the detailed material flow analyses of the PVC and WPC in production stages were carried out. The life cycle assessment has revealed that carbon footprint throughout life cycle of 1 kg of WPC wall panel is 37 % lower than those of the same weight of PVC wall panel product. Both products have a major impact on the environment during their production phase, while during this phase WPC wall panel has 35 % smaller carbon footprint and even 47 % smaller during disposal stages than those of the PVC wall panel. The results of material flow analysis have shown that recycling and reuse of production spoilage reduce the need of PVC secondary resources for PVC panels and primary WPC resources for WPC panel production. For better resource efficiency, the conceptual model of material flow management has been proposed. As WPC products are made of primary WPC granules, which are imported from abroad, the model suggests to produce the WPC granules at the company using collected PVC secondary materials (PVC stocks. It would lower environmental costs and environmental impact, increase the efficiency of resources, and diminish dependence on suppliers.

  10. 75 FR 16504 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2010-04-01

    ... existence and availability of substitute products; and the level of competition among the Domestic Like... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... countervailing duty order on certain hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel...

  11. 77 FR 45576 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...

    Science.gov (United States)

    2012-08-01

    ... Fair Value, and Affirmative Critical Circumstances, In Part: Certain Lined Paper Products From the... Than Fair Value: Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China, 66... Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary Results of...

  12. 77 FR 21527 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic of Korea: Final...

    Science.gov (United States)

    2012-04-10

    ... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic... certain cut-to-length carbon-quality steel plate products from the Republic of Korea. The review covers...-Quality Steel Plate Products From the Republic of Korea: Preliminary Results of Antidumping Duty...

  13. 75 FR 47777 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Final Results of...

    Science.gov (United States)

    2010-08-09

    ... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Final...-quality steel plate products from Italy. The review covers one manufacturer/exporter, Evraz Palini Bertoli... certain cut-to-length carbon-quality steel plate products (CTL plate) from Italy. See Certain Cut-to...

  14. 78 FR 29113 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic of Korea: Final...

    Science.gov (United States)

    2013-05-17

    ... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic... order on certain cut-to-length carbon-quality steel plate products from the Republic of Korea. For these...-quality steel plate products from the Republic of Korea (Korea).\\1\\ The period of review is February 1...

  15. Modeling of the HiPco process for carbon nanotube production. II. Reactor-scale analysis

    Science.gov (United States)

    Gokcen, Tahir; Dateo, Christopher E.; Meyyappan, M.

    2002-01-01

    The high-pressure carbon monoxide (HiPco) process, developed at Rice University, has been reported to produce single-walled carbon nanotubes from gas-phase reactions of iron carbonyl in carbon monoxide at high pressures (10-100 atm). Computational modeling is used here to develop an understanding of the HiPco process. A detailed kinetic model of the HiPco process that includes of the precursor, decomposition metal cluster formation and growth, and carbon nanotube growth was developed in the previous article (Part I). Decomposition of precursor molecules is necessary to initiate metal cluster formation. The metal clusters serve as catalysts for carbon nanotube growth. The diameter of metal clusters and number of atoms in these clusters are some of the essential information for predicting carbon nanotube formation and growth, which is then modeled by the Boudouard reaction with metal catalysts. Based on the detailed model simulations, a reduced kinetic model was also developed in Part I for use in reactor-scale flowfield calculations. Here this reduced kinetic model is integrated with a two-dimensional axisymmetric reactor flow model to predict reactor performance. Carbon nanotube growth is examined with respect to several process variables (peripheral jet temperature, reactor pressure, and Fe(CO)5 concentration) with the use of the axisymmetric model, and the computed results are compared with existing experimental data. The model yields most of the qualitative trends observed in the experiments and helps to understanding the fundamental processes in HiPco carbon nanotube production.

  16. H{sub 2} production from methane pyrolysis over commercial carbon catalysts: Kinetic and deactivation study

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, D.P.; Botas, J.A. [Chemical and Environmental Technology Department, ESCET, Rey Juan Carlos University, C/Tulipan s/n, 28933 Mostoles (Spain); IMDEA Energia, C/Tulipan s/n, 28933 Mostoles (Spain); Guil-Lopez, R. [Chemical and Environmental Technology Department, ESCET, Rey Juan Carlos University, C/Tulipan s/n, 28933 Mostoles (Spain)

    2009-05-15

    Hydrogen production from catalytic methane decomposition (DeCH{sub 4}) is a simple process to produce high purity hydrogen with no formation of carbon oxides (CO or CO{sub 2}). However, to completely avoid those emissions, the catalyst must not be regenerated. Therefore, it is necessary to use inexpensive catalysts, which show low deactivation during the process. Use of carbon materials as catalysts fulfils these requirements. Methane decomposition catalysed by a number of commercial carbons has been studied in this work using both constant and variable temperature experiments. The results obtained showed that the most active catalyst at short reaction times was activated carbon, but it underwent a fast deactivation due to the deposition of the carbon formed from methane cracking. On the contrary, carbon blacks, and especially the CB-bp sample, present high reaction rates for methane decomposition at both short and long reaction times. Carbon nanotubes exhibit a relatively low activity in spite of containing significant amounts of metals. The initial loss of activity observed with the different catalysts is attributed mainly to the blockage of their micropores due to the deposition of the carbon formed during the reaction. (author)

  17. Acetate production enhancement from carbon dioxide reduction by using modified cathode materials in microbial electrosynthesis

    DEFF Research Database (Denmark)

    Aryal, Nabin; Halder, Arnab; Zhang, Minwei

    in the bioelectrochemical System (BES). The MES reactor can power with the solar photovoltaic system and harvest light energy to multi-carbon compounds to make it artificial photosynthesis system. Nevertheless, chemical production rate should be optimized for the commercialization of MES technology. Interestingly, it has......Microbial electrosynthesis (MES) is one of the emerging biosustainable technologies for the biological conversion of carbon dioxide to the value-added chemical precursor. The electro autotrophic bacteria fix CO2 via Wood-Ljungdahl pathway, accepting the electron derived from the cathode...... been demonstrated that the productivity was enhanced with the modified cathode surfaces by improving microbe-electrode electron transfer. Here, we have tested the different cathode materials for the improvement of acetate production from carbon dioxide and their behavior for the biofilm formation...

  18. Effect of Different Carbon Source on Expression of Carotenogenic Genes and Astaxanthin Production in Xanthophyllomyces dendrorhous

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-10-01

    Full Text Available The present research gives an insight into astaxanthin production, as well as transcription differences of four key carotenogenic genes, in Xanthophyllomyces dendrorhous when cultured with various carbon sources and soybean oil as co-substrates. Glucose was found to be the carbon source with best culture growth and astaxanthin production and the addition of 2% (v/v soybean oil resulted in even higher astaxanthin producing. In addition, four carotenogenic genes encoding geranylgeranyl diphosphate synthase (crtE, phytoene desaturase (crtl, phytoene synthase lycopene cyclase(crtYB, and astaxanthin synthetase (ast, respectively, were demonstrated to be associated with different transcription levels under various substrates. The present study suggests the effectiveness of manipulating the metabolic regulation by using different carbon sources, in order to improve the production of astaxanthin.

  19. Microbial primary production on an Arctic glacier is insignificant in comparison with allochthonous organic carbon input.

    Science.gov (United States)

    Stibal, Marek; Tranter, Martyn; Benning, Liane G; Rehák, Josef

    2008-08-01

    Cryoconite holes are unique freshwater environments on glacier surfaces, formed when solar-heated dark debris melts down into the ice. Active photoautotrophic microorganisms are abundant within the holes and fix inorganic carbon due to the availability of liquid water and solar radiation. Cryoconite holes are potentially important sources of organic carbon to the glacial ecosystem, but the relative magnitudes of autochthonous microbial primary production and wind-borne allochthonous organic matter brought are unknown. Here, we compare an estimate of annual microbial primary production in 2006 on Werenskioldbreen, a Svalbard glacier, with the organic carbon content of cryoconite debris. There is a great disparity between annual primary production (4.3 mug C g(-1) year(-1)) and the high content of organic carbon within the debris (1.7-4.5%, equivalent to 8500-22 000 mug C g(-1) debris). Long-term accumulation of autochthonous organic matter is considered unlikely due to ablation dynamics and the surface hydrology of the glacier. Rather, it is more likely that the majority of the organic matter on Werenskioldbreen is allochthonous. Hence, although glacier surfaces can be a significant source of organic carbon for glacial environments on Svalbard, they may be reservoirs rather than oases of high productivity.

  20. Characterization of cellulase production by carbon sources in two ...

    African Journals Online (AJOL)

    user7

    2013-11-27

    Nov 27, 2013 ... Green Chemical Technology of College of Heilongjiang Province, Harbin, ... acted on these inducers, analysis of reaction products by high ... trolled by complicated metabolic process. ... cellulase yield as well as to design screen model which ... synthesis of cellulase can be induced by many oligomeric.

  1. Low Carbon Technology Options for the Natural Gas Electricity Production

    Science.gov (United States)

    The ultimate goal of this task is to perform environmental and economic analysis of natural gas based power production technologies (different routes) to investigate and evaluate strategies for reducing emissions from the power sector. It is a broad research area. Initially, the...

  2. Low Carbon Technology Options for the Natural Gas Electricity Production

    Science.gov (United States)

    The ultimate goal of this task is to perform environmental and economic analysis of natural gas based power production technologies (different routes) to investigate and evaluate strategies for reducing emissions from the power sector. It is a broad research area. Initially, the...

  3. Replica exchange simulations of the three-dimensional Ising spin glass: static and dynamic properties

    Science.gov (United States)

    Yucesoy, Burcu; Machta, Jonathan; Katzgraber, Helmut G.

    2012-02-01

    We present the results of a large-scale numerical study of the equilibrium three-dimensional Ising spin glass with Gaussian disorder. Using replica exchange (parallel tempering) Monte Carlo, we measure various static, as well as dynamical quantities, such as the autocorrelation times and round-trip times for the replica exchange Monte Carlo method. The correlation between static and dynamic observables for 5000 disorder realizations (N <=10^3 spins) down to very low temperatures (T 0.2Tc) is examined. Our results show that autocorrelation times are directly correlated with the roughness of the free energy landscape. We also discuss the size dependence of several static quantities.

  4. Implementation of replica-exchange umbrella sampling in the DFTB + semiempirical quantum chemistry package

    Science.gov (United States)

    Ito, Shingo; Irle, Stephan; Okamoto, Yuko

    2016-07-01

    The replica-exchange umbrella sampling (REUS) method combines replica-exchange and umbrella sampling methods and allows larger conformational sampling than conventional simulation methods. This method has been used in many studies to understand docking mechanisms and the functions of molecules. However, REUS has not been combined with quantum chemical codes. Therefore, we implemented the REUS simulation technique in the DFTB + quantum chemistry code utilizing approximate density functional theory. We performed REUS simulations of an intra-molecular proton transfer reaction of malonaldehyde and a formation of a phthalocyanine from four phthalonitriles and one iron atom to validate the reliability of our implemented REUS-DFTB + combination.

  5. Nickel replicas as calibration reference standards for industrial surface texture instruments

    DEFF Research Database (Denmark)

    Sammatini-Malberg, Maria-Pia

    The present report is a documentation of measurements carried out at DTU on Nickel replicas. The research is performed in the frame of the project with contract SMT4-CT97-2176 with title: Calibration Standards for Surface Topography Measuring Systems down to Nanometric Scale.......The present report is a documentation of measurements carried out at DTU on Nickel replicas. The research is performed in the frame of the project with contract SMT4-CT97-2176 with title: Calibration Standards for Surface Topography Measuring Systems down to Nanometric Scale....

  6. Farm and product carbon footprints of China's fruit production--life cycle inventory of representative orchards of five major fruits.

    Science.gov (United States)

    Yan, Ming; Cheng, Kun; Yue, Qian; Yan, Yu; Rees, Robert M; Pan, Genxing

    2016-03-01

    Understanding the environmental impacts of fruit production will provide fundamental information for policy making of fruit consumption and marketing. This study aims to characterize the carbon footprints of China's fruit production and to figure out the key greenhouse gas emissions to cut with improved orchard management. Yearly input data of materials and energy in a full life cycle from material production to fruit harvest were obtained via field visits to orchards of five typical fruit types from selected areas of China. Carbon footprint (CF) was assessed with quantifying the greenhouse gas emissions associated with the individual inputs. Farm and product CFs were respectively predicted in terms of land use and of fresh fruit yield. Additionally, product CFs scaled by fruit nutrition value (vitamin C (Vc) content) and by the economic benefit from fruit production were also evaluated. The estimated farm CF ranged from 2.9 to 12.8 t CO2-eq ha(-1) across the surveyed orchards, whereas the product CF ranged from 0.07 to 0.7 kg CO2-eq kg(-1) fruit. While the mean product CFs of orange and pear were significantly lower than those of apple, banana, and peach, the nutrition-scaled CF of orange (0.5 kg CO2-eq g(-1) Vc on average) was significantly lower than others (3.0-5.9 kg CO2-eq g(-1) Vc). The income-scaled CF of orange and pear (1.20 and 1.01 kg CO2-eq USD(-1), respectively) was higher than apple, banana, and peach (0.87~0.39 kg CO2-eq USD(-1)). Among the inputs, synthetic nitrogen fertilizer contributed by over 50 % to the total greenhouse gas (GHG) emissions, varying among the fruit types. There were some tradeoffs in product CFs between fruit nutrition value and fruit growers' income. Low carbon production and consumption policy and marketing mechanism should be developed to cut down carbon emissions from fruit production sector, with balancing the nutrition value, producer's income, and climate change mitigation.

  7. Activated carbon from pyrolysis of brewer's spent grain: Production and adsorption properties.

    Science.gov (United States)

    Vanreppelen, Kenny; Vanderheyden, Sara; Kuppens, Tom; Schreurs, Sonja; Yperman, Jan; Carleer, Robert

    2014-07-01

    Brewer's spent grain is a low cost residue generated by the brewing industry. Its chemical composition (high nitrogen content 4.35 wt.%, fibres, etc.) makes it very useful for the production of added value in situ nitrogenised activated carbon. The composition of brewer's spent grain revealed high amounts of cellulose (20.8 wt.%), hemicellulose (48.78 wt.%) and lignin (11.3 wt.%). The fat, ethanol extractives and ash accounted for 8.17 wt.%, 4.7 wt.% and 3.2 wt.%, respectively. Different activated carbons were produced in a lab-scale pyrolysis/activation reactor by applying several heat and steam activation profiles on brewer's spent grain. Activated carbon yields from 16.1 to 23.6 wt.% with high N-contents (> 2 wt.%) were obtained. The efficiency of the prepared activated carbons for phenol adsorption was studied as a function of different parameters: pH, contact time and carbon dosage relative to two commercial activated carbons. The equilibrium isotherms were described by the non-linear Langmuir and Freundlich models, and the kinetic results were fitted using the pseudo-first-order model and the pseudo-second-order model. The feasibility of an activated carbon production facility (onsite and offsite) that processes brewer's spent grain for different input feeds is evaluated based on a techno-economic model for estimating the net present value. Even though the model assumptions start from a rather pessimistic scenario, encouraging results for a profitable production of activated carbon using brewer's spent grain are obtained.

  8. Solid olive waste in environmental cleanup: oil recovery and carbon production for water purification.

    Science.gov (United States)

    El-Hamouz, Amer; Hilal, Hikmat S; Nassar, Nashaat; Mardawi, Zahi

    2007-07-01

    A potentially-economic three-fold strategy, to use solid olive wastes in water purification, is presented. Firstly, oil remaining in solid waste (higher than 5% of waste) was recovered by the Soxhlet extraction technique, which can be useful for the soap industry. Secondly, the remaining solid was processed to yield relatively high-surface area active carbon (AC). Thirdly, the resulting carbon was employed to reversibly adsorb chromate ions from water, aiming to establish a water purification process with reusable AC. The technique used here enabled oil recovery together with the production of a clean solid, suitable for making AC. This process also has the advantage of low production cost.

  9. Carbon stars and galactic chemical evolution: production of s-elements and wind heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    De Laverny, P [Observatoire de la Cote d' Azur, Dept. Cassiopee, UMR 6202, Nice (France)], E-mail: laverny@oca.eu

    2008-12-15

    Cool carbon stars found on the asymptotic giant branch are characterized by their production of specific chemical species and by strong but complex winds. This is illustrated below by (i) discussing their production of s-elements in the Milky Way and in neighbour satellite galaxies and (ii) describing the strong heterogeneities observed in the massive dusty circumstellar envelope of the nearby carbon star IRC+10216. Some similarities existing between the inner clumpy envelope of IRC+10216 with the dusty clumps recently detected around the more evolved variable stars of R Coronae Borealis type are also discussed.

  10. Linear extension rates and gross carbonate production of Acropora cervicornis at Coral Gardens, Belize.

    Science.gov (United States)

    Peeling, E.; Greer, L.; Lescinsky, H.; Humston, R.; Wirth, K. R.; Baums, I. B.; Curran, A.

    2014-12-01

    Branching Acropora coral species have fast growth and carbonate production rates, and thus have functioned as important reef-building species throughout the Pleistocene and Holocene. Recently, net carbonate production (kg CaCO3 m-2 year-1) has been recognized as an important measure of reef health, especially when monitoring endangered species, such as Acropora cervicornis. This study examines carbonate production in a thriving population of A. cervicornis at the Coral Gardens reef in Belize. Photographic surveys were conducted along five transects of A. cervicornis-dominated reefs from 2011-2014. Matching photographs from 2013 and 2014 were scaled to 1 m2 and compared to calculate 84 individual A. cervicornis linear extension rates across the reef. Linear extension rates averaged 12.4 cm/yr and were as high as 17 cm/yr in some areas of the reef. Carbonate production was calculated two ways. The first followed the standard procedure of multiplying percent live coral cover, by the linear extension rate and skeletal density. The second used the number of live coral tips per square meter in place of percent live coral multiplied by the average cross-sectional area of the branches. The standard method yielded a carbonate production rate of 113 kg CaCO3 m-2 year-1 for the reef, and the tip method yielded a rate of 6 kg m-2 year-1. We suggest that the tip method is a more accurate measure of production, because A. cervicornis grows primarily from the live tips, with only limited radial growth and resheeting over dead skeleton. While this method omits the contributions of radial growth and resheeting, and is therefore somewhat of an underestimate, our future work will quantify these aspects of growth in a more complete carbonate budget. Still, our estimate suggests a carbonate production rate per unit area of A. cervicornis that is on par with other Caribbean coral species, rather than two orders of magnitude higher as reported by Perry et al (2013). Although gross coral

  11. Carbon Footprint Analysis for Mechanization of Maize Production Based on Life Cycle Assessment: A Case Study in Jilin Province, China

    Directory of Open Access Journals (Sweden)

    Haina Wang

    2015-11-01

    Full Text Available The theory on the carbon footprint of agriculture can systematically evaluate the carbon emissions caused by artificial factors from the agricultural production process, which is the theoretical basis for constructing low-carbon agriculture and has important guiding significance for realizing low-carbon agriculture. Based on farm production survey data from Jilin Province in 2014, this paper aims to obtain a clear understanding of the carbon footprint of maize production through the following method: (1 one ton of maize production was evaluated systematically by using the Life Cycle Assessment (LCA; (2 the carbon emissions of the whole system were estimated based on field measurement data, (3 using the emission factors we estimated Jilin’s carbon footprint for the period 2006–2013, and forecasted it for the period from 2014 to 2020 using the grey system model GM (1, 1.

  12. Algal biomass production and carbon fixation from flue gas

    Institute of Scientific and Technical Information of China (English)

    WANG Ling; ZHU Jing

    2016-01-01

    Algal biofuel has established as one of renewable energy. In this study, Nannochloropsis salina was cultured to test feasibility of biomass production and CO2 fixation from flue gas. Firstly, cultivation was conducted under different light intensity. Results showed that the highest dry biomass of 1.25±0.061 g/L was achieved at light intensity of 10klux, while the highest total lipids was 33.677±1.9% at light intensity of 15klux. The effect of mercury on algae growth was also investigated, the algae growth was serious limited at the presence of mercury, and there was no any difference at the range of 10-50 ug/m3. These results provide useful information for algal biomass production and CO2 fixation from flue gas.

  13. Production of carbon-rich presolar grains from massive stars

    CERN Document Server

    Pignatari, M; Timmes, F X; de Boer, R J; Thielemann, F -K; Fryer, C; Heger, A; Herwig, F; Hirschi, R

    2013-01-01

    About a year after core collapse supernova, dust starts to condense in the ejecta. In meteorites, a fraction of C-rich presolar grains (e.g., silicon carbide (SiC) grains of Type-X and low density graphites) are identified as relics of these events, according to the anomalous isotopic abundances. Several features of these abundances remain unexplained and challenge the understanding of core-collapse supernovae explosions and nucleosynthesis. We show, for the first time, that most of the measured C-rich grain abundances can be accounted for in the C-rich material from explosive He burning in core-collapse supernovae with high shock velocities and consequent high temperatures. The inefficiency of the $^{12}$C($\\alpha$,$\\gamma$)$^{16}$O reaction relative to the rest of the $\\alpha$-capture chain at $T > 3.5\\times10^8 \\mathrm{K}$ causes the deepest He-shell material to be carbon rich and silicon rich, and depleted in oxygen. The isotopic ratio predictions in part of this material, defined here as the C/Si zone, a...

  14. On the Application of Replica Molding Technology for the Indirect Measurement of Surface and Geometry of Micromilled Components

    DEFF Research Database (Denmark)

    Baruffi, Federico; Parenti, Paolo; Cacciatore, Francesco

    2017-01-01

    the replica molding technology. The method consists of obtaining a replica of the feature that is inaccessible for standard measurement devices and performing its indirect measurement. This paper examines the performance of a commercial replication media applied to the indirect measurement of micromilled...

  15. Technoeconomical analysis of the co-production of hydrogen energy and carbon materials

    Science.gov (United States)

    Guerra, Zuimdie

    HECAM (Hydrogen Energy and Carbon Materials) is a new energy production strategy. The main paradigm of HECAM is that energy extracted from the carbon in hydrocarbon fuels is not worth the production of carbon dioxide. The hydrocarbon fuel is heated in an oxygen free environment and it is chemically decomposed by the heat into gases (mostly hydrogen and methane), small quantities of liquid (light oil and tar), and a solid residue containing carbon and ash (char or coke). More quantities of hydrocarbons will need to be used, but less carbon dioxide will be produced. HECAM is going to compete with steam methane reforming (SMR) to produce hydrogen. HECAM with thermocatalytic decomposition of methane and efficient sensible heat recovery has a production cost per gigajoule of hydrogen about 9% higher than SMR, but will produce about half the carbon dioxide emissions that SMR produces. If HECAM with efficient sensible heat recovery is used to produce electricity in a power plant, it will have a comparable electricity production cost and carbon dioxide emissions to a natural gas combined cycle (NGCC) power plant. The byproduct coke is not a waste residue, but a valuable co-product. Uses for the byproduct coke material may be carbon sequestration, mine land restoration, additive to enhance agricultural soils, low sulfur and mercury content heating fuel for power plants, new construction materials, or carbon-base industrial materials. This study investigated the use of byproduct coke for new construction materials. HECAM concrete substitute (HCS) materials will have a comparable cost with concrete when the cost of the raw materials is $65 per metric ton of HCS produced. HECAM brick substitute (HBS) materials will have 20% higher cost per brick than clay bricks. If the HECAM byproduct coke can be formed into bricks as a product of the HECAM process, the manufacture of HBS bricks will be cheaper and may be cost competitive with clay bricks. The results of this analysis are

  16. Greenhouse gas and carbon profile of the u.s. Forest products industry value chain.

    Science.gov (United States)

    Heath, Linda S; Maltby, Van; Miner, Reid; Skog, Kenneth E; Smith, James E; Unwin, Jay; Upton, Brad

    2010-05-15

    A greenhouse gas and carbon accounting profile was developed for the U.S. forest products industry value chain for 1990 and 2004-2005 by examining net atmospheric fluxes of CO(2) and other greenhouse gases (GHGs) using a variety of methods and data sources. Major GHG emission sources include direct and indirect (from purchased electricity generation) emissions from manufacturing and methane emissions from landfilled products. Forest carbon stocks in forests supplying wood to the industry were found to be stable or increasing. Increases in the annual amounts of carbon removed from the atmosphere and stored in forest products offset about half of the total value chain emissions. Overall net transfers to the atmosphere totaled 91.8 and 103.5 TgCO(2)-eq. in 1990 and 2005, respectively, although the difference between these net transfers may not be statistically significant. Net transfers were higher in 2005 primarily because additions to carbon stored in forest products were less in 2005. Over this same period, energy-related manufacturing emissions decreased by almost 9% even though forest products output increased by approximately 15%. Several types of avoided emissions were considered separately and were collectively found to be notable relative to net emissions.

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

    Science.gov (United States)

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

    2016-04-01

    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 productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is < 2000 mm yr-1 (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall < 2000 mm yr-1.

  18. Production and characterization of carbonized sorbent products optimized for anionic contaminants

    Science.gov (United States)

    Viglasova, Eva; Fristak, Vladimir; Galambos, Michal; Hood-Nowotny, Rebecca; Soja, Gerhard

    2017-04-01

    Processing conditions, production methods and feedstock characteristics have been shown to affect the final sorption properties of biochar-based sorbents that have been produced in pyrolysis reactors. The content of O-containing carboxyl, phenolic and hydroxyl functional groups on the biochar surfaces plays a crucial role in sorption chemistry of hazardous materials. The sorption process can be affected by the presence of non-carbonized fractions in biochar matter as well. All these characteristics indicate that biochar shows good potential as a new tool in removal and separation technologies of various pollutants from waste water or contaminated soils. The sorption potential of wood-based biochars for cationic forms of heavy metals has been studied intensively and has already led to successful pilot applications in the field. However, anionic compounds (e.g. phosphate, nitrate, sulphate, As-, Cr-compounds) do not sorb well to unmodified biochar and need specific surface modification of biochar. Based on this fact, we try to obtain data about the sorptive separation of anionic forms of various contaminants from model aqueous solutions by different types of biochar-derived sorbents, or mineral-enriched biochar-derived sorbents. An important part of this research is the assesment of the effects of varying process parameters during biomass carbonisation, the role of biomass feedstock and pre-and/or post-treatment of the biochars onto sorption processes. We specify the most appropriate application strategies with biochar for remediation purposes of waste water or contaminated waters with elevated toxic metal concentrations that might compromise the quality of surface waters. The main aim of research is the preparation of modified biochar sorbent, the characterization of its surface and the investigation about new possibilities of modified biochar sorbent applications for sorption of various contaminants, mainly their anionic forms (e.g. phosphates, nitrates, arsenates

  19. Modeling of the HiPco process for carbon nanotube production. I. Chemical kinetics

    Science.gov (United States)

    Dateo, Christopher E.; Gokcen, Tahir; Meyyappan, M.

    2002-01-01

    A chemical kinetic model is developed to help understand and optimize the production of single-walled carbon nanotubes via the high-pressure carbon monoxide (HiPco) process, which employs iron pentacarbonyl as the catalyst precursor and carbon monoxide as the carbon feedstock. The model separates the HiPco process into three steps, precursor decomposition, catalyst growth and evaporation, and carbon nanotube production resulting from the catalyst-enhanced disproportionation of carbon monoxide, known as the Boudouard reaction: 2 CO(g)-->C(s) + CO2(g). The resulting detailed model contains 971 species and 1948 chemical reactions. A second model with a reduced reaction set containing 14 species and 22 chemical reactions is developed on the basis of the detailed model and reproduces the chemistry of the major species. Results showing the parametric dependence of temperature, total pressure, and initial precursor partial pressures are presented, with comparison between the two models. The reduced model is more amenable to coupled reacting flow-field simulations, presented in the following article.

  20. Joint Optimal Production Planning for Complex Supply Chains Constrained by Carbon Emission Abatement Policies

    Directory of Open Access Journals (Sweden)

    Longfei He

    2014-01-01

    Full Text Available We focus on the joint production planning of complex supply chains facing stochastic demands and being constrained by carbon emission reduction policies. We pick two typical carbon emission reduction policies to research how emission regulation influences the profit and carbon footprint of a typical supply chain. We use the input-output model to capture the interrelated demand link between an arbitrary pair of two nodes in scenarios without or with carbon emission constraints. We design optimization algorithm to obtain joint optimal production quantities combination for maximizing overall profit under regulatory policies, respectively. Furthermore, numerical studies by featuring exponentially distributed demand compare systemwide performances in various scenarios. We build the “carbon emission elasticity of profit (CEEP” index as a metric to evaluate the impact of regulatory policies on both chainwide emissions and profit. Our results manifest that by facilitating the mandatory emission cap in proper installation within the network one can balance well effective emission reduction and associated acceptable profit loss. The outcome that CEEP index when implementing Carbon emission tax is elastic implies that the scale of profit loss is greater than that of emission reduction, which shows that this policy is less effective than mandatory cap from industry standpoint at least.

  1. Brazilian natural fiber (jute as raw material for activated carbon production

    Directory of Open Access Journals (Sweden)

    CARLA F.S. ROMBALDO

    2014-12-01

    Full Text Available Jute fiber is the second most common natural cellulose fiber worldwide, especially in recent years, due to its excellent physical, chemical and structural properties. The objective of this paper was to investigate: the thermal degradation of in natura jute fiber, and the production and characterization of the generated activated carbon. The production consisted of carbonization of the jute fiber and activation with steam. During the activation step the amorphous carbon produced in the initial carbonization step reacted with oxidizing gas, forming new pores and opening closed pores, which enhanced the adsorptive capacity of the activated carbon. N2 gas adsorption at 77K was used in order to evaluate the effect of the carbonization and activation steps. The results of the adsorption indicate the possibility of producing a porous material with a combination of microporous and mesoporous structure, depending on the parameters used in the processes, with resulting specific surface area around 470 m2.g–1. The thermal analysis indicates that above 600°C there is no significant mass loss.

  2. Production of long chain alkyl esters from carbon dioxide and electricity by a two-stage bacterial process.

    Science.gov (United States)

    Lehtinen, Tapio; Efimova, Elena; Tremblay, Pier-Luc; Santala, Suvi; Zhang, Tian; Santala, Ville

    2017-11-01

    Microbial electrosynthesis (MES) is a promising technology for the reduction of carbon dioxide into value-added multicarbon molecules. In order to broaden the product profile of MES processes, we developed a two-stage process for microbial conversion of carbon dioxide and electricity into long chain alkyl esters. In the first stage, the carbon dioxide is reduced to organic compounds, mainly acetate, in a MES process by Sporomusa ovata. In the second stage, the liquid end-products of the MES process are converted to the final product by a second microorganism, Acinetobacter baylyi in an aerobic bioprocess. In this proof-of-principle study, we demonstrate for the first time the bacterial production of long alkyl esters (wax esters) from carbon dioxide and electricity as the sole sources of carbon and energy. The process holds potential for the efficient production of carbon-neutral chemicals or biofuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Predicting long-term carbon mineralization and trace gas production from thawing permafrost of Northeast Siberia.

    Science.gov (United States)

    Knoblauch, Christian; Beer, Christian; Sosnin, Alexander; Wagner, Dirk; Pfeiffer, Eva-Maria

    2013-04-01

    The currently observed Arctic warming will increase permafrost degradation followed by mineralization of formerly frozen organic matter to carbon dioxide (CO2 ) and methane (CH4 ). Despite increasing awareness of permafrost carbon vulnerability, the potential long-term formation of trace gases from thawing permafrost remains unclear. The objective of the current study is to quantify the potential long-term release of trace gases from permafrost organic matter. Therefore, Holocene and Pleistocene permafrost deposits were sampled in the Lena River Delta, Northeast Siberia. The sampled permafrost contained between 0.6% and 12.4% organic carbon. CO2 and CH4 production was measured for 1200 days in aerobic and anaerobic incubations at 4 °C. The derived fluxes were used to estimate parameters of a two pool carbon degradation model. Total CO2 production was similar in Holocene permafrost (1.3 ± 0.8 mg CO2 -C gdw(-1) aerobically, 0.25 ± 0.13 mg CO2 -C gdw(-1) anaerobically) as in 34 000-42 000-year-old Pleistocene permafrost (1.6 ± 1.2 mg CO2 -C gdw(-1) aerobically, 0.26 ± 0.10 mg CO2 -C gdw(-1) anaerobically). The main predictor for carbon mineralization was the content of organic matter. Anaerobic conditions strongly reduced carbon mineralization since only 25% of aerobically mineralized carbon was released as CO2 and CH4 in the absence of oxygen. CH4 production was low or absent in most of the Pleistocene permafrost and always started after a significant delay. After 1200 days on average 3.1% of initial carbon was mineralized to CO2 under aerobic conditions while without oxygen 0.55% were released as CO2 and 0.28% as CH4 . The calibrated carbon degradation model predicted cumulative CO2 production over a period of 100 years accounting for 15.1% (aerobic) and 1.8% (anaerobic) of initial organic carbon, which is significantly less than recent estimates. The multiyear time series from the incubation experiments helps to more reliably constrain projections of future

  4. Bicarbonate-based Integrated Carbon Capture and Algae Production System with alkalihalophilic cyanobacterium.

    Science.gov (United States)

    Chi, Zhanyou; Xie, Yuxiao; Elloy, Farah; Zheng, Yubin; Hu, Yucai; Chen, Shulin

    2013-04-01

    An extremely alkalihalophilic cyanobacteria Euhalothece ZM001 was tested in the Bicarbonate-based Integrated Carbon Capture and Algae Production System (BICCAPS), which utilize bicarbonate as carbon source for algae culture and use the regenerated carbonate to absorb CO2. Culture conditions including temperature, inoculation rate, medium composition, pH, and light intensity were investigated. A final biomass concentration of 4.79 g/L was reached in tissue flask culture with 1.0 M NaHCO3/Na2CO3. The biomass productivity of 1.21 g/L/day was achieved under optimal conditions. When pH increased from 9.55 to 10.51, 0.256 M of inorganic carbon was consumed during the culture process. This indicated sufficient carbon can be supplied as bicarbonate to the culture. This study proved that a high biomass production rate can be achieved in a BICCAPS. This strategy can also lead to new design of photobioreactors that provides an alternative supply of CO2 to sparging.

  5. Effects of anthropogenic fragmentation on primary productivity and soil carbon storage in temperate mountain grasslands.

    Science.gov (United States)

    Cojoc, Emilia Ionela; Postolache, Carmen; Olariu, Bogdan; Beierkuhnlein, Carl

    2016-11-01

    Habitat fragmentation is one of the most severe anthropogenic pressures exerted on ecosystem's biodiversity. Empirical studies to date focused with an overriding interest on the effects of habitat loss or habitat fragmentation per se on species richness patterns detrimental to biogeochemical processes. To account for changes in ecosystem fluxes, we investigated how anthropogenic fragmentation affects primary productivity and carbon storage in temperate mountain grasslands. A field study was conducted to assess the influence of grassland isolation on soil carbon stocks, N availability, species biomass, and plant functional groups distribution. We tested the hypothesis that increased isolation of grassland, within the land cover, decreases soil carbon stocks, and available N nutrient as well as aboveground biomass. Soil carbon concentration decreased with isolation but increased near the forest edge. We found significant differences in aboveground biomass distribution and relative contribution of plant functional groups between isolation conditions. The magnitude of edge effect on carbon stocks, N availability, and primary productivity intensified with increasing isolation as a consequence of the additive influence of edges. Our study reveals that the potential creation of artificially isolated patches diminished primary productivity, N availability, and C stocks. However, in highly managed landscapes, grazing pressure is an additional factor that changes biomass and nutrients patterns. We emphasize that spatial configuration of the landscape has a major role in modulating ecological flows and ecosystem service supply, in addition to changes in species richness.

  6. Continuous production of carbon nanotubes and diamond films by swirled floating catalyst chemical vapour deposition method

    Directory of Open Access Journals (Sweden)

    S.E. Iyuke

    2010-01-01

    Full Text Available Various techniques for the synthesis of carbon nanotubes (CNTs are being developed to meet an increasing demand as a result of their versatile applications. Swirled floating catalyst chemical vapour deposition (SFCCVD is one of these techniques. This method was used to synthesise CNTs on a continuous basis using acetylene gas as a carbon source, ferrocene dissolved in xylene as a catalyst precursor, and both hydrogen and argon as carrier gases. Transmission electron microscopy analyses revealed that a mixture of single and multi-wall carbon nanotubes and other carbon nanomaterials were produced within the pyrolytic temperature range of 900–1 100°C and acetylene flow rate range of 118–370 ml min–1. Image comparison of raw and purified products showed that low contents of iron particles and amorphous carbon were contained in the synthesised carbon nanotubes. Diamond films were produced at high ferrocene concentration, hydrogen flow rate and pyrolysis temperatures, while carbon nanoballs were formed and attached to the surface of theCNTs at low ferrocene content and low pyrolysis temperature.

  7. Ancient low–molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw

    Science.gov (United States)

    Drake, Travis W.; Wickland, Kimberly P.; Spencer, Robert G. M.; McKnight, Diane M.; Striegl, Robert G.

    2015-01-01

    Northern permafrost soils store a vast reservoir of carbon, nearly twice that of the present atmosphere. Current and projected climate warming threatens widespread thaw of these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized permafrost OC in dissolved and particulate forms can enter streams and rivers, which are important processors of OC and conduits for carbon dioxide (CO2) to the atmosphere. Here, we demonstrate that ancient dissolved organic carbon (DOC) leached from 35,800 y B.P. permafrost soils is rapidly mineralized to CO2. During 200-h experiments in a novel high–temporal-resolution bioreactor, DOC concentration decreased by an average of 53%, fueling a more than sevenfold increase in dissolved inorganic carbon (DIC) concentration. Eighty-seven percent of the DOC loss to microbial uptake was derived from the low–molecular-weight (LMW) organic acids acetate and butyrate. To our knowledge, our study is the first to directly quantify high CO2 production rates from permafrost-derived LMW DOC mineralization. The observed DOC loss rates are among the highest reported for permafrost carbon and demonstrate the potential importance of LMW DOC in driving the rapid metabolism of Pleistocene-age permafrost carbon upon thaw and the outgassing of CO2 to the atmosphere by soils and nearby inland waters.

  8. Carbon-rich dust production in metal-poor galaxies in the Local Group

    CERN Document Server

    Sloan, G C; Lagadec, E; van Loon, J Th; Kraemer, K E; McDonald, I; Groenewegen, M A T; Wood, P R; Bernard-Salas, J; Zijlstra, A A

    2012-01-01

    We have observed a sample of 19 carbon stars in the Sculptor, Carina, Fornax, and Leo I dwarf spheroidal galaxies with the Infrared Spectrograph on the Spitzer Space Telescope. The spectra show significant quantities of dust around the carbon stars in Sculptor, Fornax, and Leo I, but little in Carina. Previous comparisons of carbon stars with similar pulsation properties in the Galaxy and the Magellanic Clouds revealed no evidence that metallicity affected the production of dust by carbon stars. However, the more metal-poor stars in the current sample appear to be generating less dust. These data extend two known trends to lower metallicities. In more metal-poor samples, the SiC dust emission weakens, while the acetylene absorption strengthens. The bolometric magnitudes and infrared spectral properties of the carbon stars in Fornax are consistent with metallicities more similar to carbon stars in the Magellanic Clouds than in the other dwarf spheroidals in our sample. A study of the carbon budget in these sta...

  9. Waste oil shale ash as a novel source of calcium for precipitated calcium carbonate: Carbonation mechanism, modeling, and product characterization

    Energy Technology Data Exchange (ETDEWEB)

    Velts, O., E-mail: olga.velts@ttu.ee [Laboratory of Inorganic Materials, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086 (Estonia); Laboratory of Separation Technology, Lappeenranta University of Technology, P.O. Box 20, Lappeenranta FI-53851 (Finland); Uibu, M.; Kallas, J.; Kuusik, R. [Laboratory of Inorganic Materials, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086 (Estonia)

    2011-11-15

    Highlights: {yields} A method for converting oil shale waste ash into precipitated CaCO{sub 3} is elucidated. {yields} We discuss the mechanism of hazardous alkaline ash leachates carbonation. {yields} We report a model describing precipitation of CaCO{sub 3} from multi-ionic ash leachates. {yields} Model enables simulation of reactive species concentration profiles. {yields} Product contained {approx}96% CaCO{sub 3} with 4-10 {mu}m size calcite or/and vaterite particles. - Abstract: In this paper, a method for converting lime-containing oil shale waste ash into precipitated calcium carbonate (PCC), a valuable commodity is elucidated. The mechanism of ash leachates carbonation was experimentally investigated in a stirred semi-batch barboter-type reactor by varying the CO{sub 2} partial pressure, gas flow rate, and agitation intensity. A consistent set of model equations and physical-chemical parameters is proposed to describe the CaCO{sub 3} precipitation process from oil shale ash leachates of complex composition. The model enables the simulation of reactive species (Ca{sup 2+}, CaCO{sub 3}, SO{sub 4}{sup 2-}, CaSO{sub 4}, OH{sup -}, CO{sub 2}, HCO{sub 3}{sup -}, H{sup +}, CO{sub 3}{sup 2-}) concentration profiles in the liquid, gas, and solid phases as well as prediction of the PCC formation rate. The presence of CaSO{sub 4} in the product may also be evaluated and used to assess the purity of the PCC product. A detailed characterization of the PCC precipitates crystallized from oil shale ash leachates is also provided. High brightness PCC (containing up to {approx}96% CaCO{sub 3}) with mean particle sizes ranging from 4 to 10 {mu}m and controllable morphology (such as rhombohedral calcite or coexisting calcite and spherical vaterite phases) was obtained under the conditions studied.

  10. Carbon Balance and Contribution of Harvested Wood Products in China Based on the Production Approach of the Intergovernmental Panel on Climate Change

    Directory of Open Access Journals (Sweden)

    Chunyi Ji

    2016-11-01

    Full Text Available The carbon sequestration of harvested wood products (HWP plays an important role in climate mitigation. Accounting the carbon contribution of national HWP carbon pools has been listed as one of the key topics for negotiation in the United Nations Framework Convention on Climate Change. On the basis of the revised Production Approach of the Intergovernmental Panel on Climate Change (2013 (IPCC, this study assessed the accounting of carbon stock and emissions from the HWP pool in China and then analyzed its balance and contribution to carbon mitigation from 1960 to 2014. Research results showed that the accumulated carbon stock in China’s HWP carbon pool increased from 130 Teragrams Carbon (TgC in 1960 to 705.6 TgC in 2014. The annual increment in the carbon stock rose from 3.2 TgC in 1960 to 45.2 TgC in 2014. The category of solid wood products accounted for approximately 95% of the annual amount. The reduction in carbon emissions was approximately twelve times that of the emissions from the HWP producing and processing stage during the last decade. Furthermore, the amount of carbon stock and emission reduction increased from 23 TgC in 1960 to 76.1 TgC in 2014. The annual contribution of HWP could compensate for approximately 2.9% of the national carbon dioxide emissions in China.

  11. Modelling black spruce primary production and carbon allocation in the Quebec boreal forest

    Science.gov (United States)

    Gennaretti, Fabio; Guiot, Joel; Berninger, Frank; Boucher, Etienne; Gea-Izquierdo, Guillermo

    2017-04-01

    Boreal ecosystems are crucial carbon stores that must be urgently quantified and preserved. Their future evolution is extremely important for the global carbon budget. Here, we will show the progresses achieved with the MAIDEN forest ecophysiological model in simulating carbon fluxes of black spruce (Picea mariana (Mill.) B.S.P.) forests, the most representative ecosystem of the North American boreal biome. Starting from daily minimum-maximum air temperature, precipitation and CO2 atmospheric concentration, MAIDEN models the phenological (5 phenological phases are simulated each year) and meteorological controls on gross primary production (GPP) and carbon allocation to stem. The model is being calibrated on eddy covariance and tree-ring data. We will discuss the model's performance and the modifications introduced in MAIDEN to adapt the model to temperature sensitive forests of the boreal region.

  12. Energy efficiency, low-carbon energy production, and economic growth in CIS countries

    Science.gov (United States)

    Vazim, A.; Kochetkova, O.; Azimzhamov, I.; Shvagrukova, E.; Dmitrieva, N.

    2016-09-01

    The paper studies the peculiarities of energy efficiency increase in national economy and decrease of carbon dioxide emission for CIS countries. The conditions that allow achieving parameters of sustainable development are determined according to indexes of GDP energy intensity and carbon intensity. Focusing on the indexes of GDP energy intensity and carbon intensity dynamics as well as on carbon intensity of energy production, a real movement towards implementation of program conditions presented by international organizations is analyzed, namely, economic conversion to the model of sustainable development. The examples demonstrate both the presence of significant differences between 12 countries and the lack of fatality in these differences. At determining dependencies linear models are preferred to non-linear ones, with the explanation of reasons in each particular case. Attention to success of these countries may help to understand the advantages of conversion to the model of sustainable development and also it helps to decrease demands in terms of costs for this conversion.

  13. ENHANCED HYDROGEN ECONOMICS VIA COPRODUCTION OF FUELS AND CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Kennel, Elliot B; Bhagavatula, Abhijit; Dadyburjor, Dady; Dixit, Santhoshi; Garlapalli, Ravinder; Magean, Liviu; Mukkha, Mayuri; Olajide, Olufemi A; Stiller, Alfred H; Yurchick, Christopher L

    2011-03-31

    This Department of Energy National Energy Technology Laboratory sponsored research effort to develop environmentally cleaner projects as a spin-off of the FutureGen project, which seeks to reduce or eliminate emissions from plants that utilize coal for power or hydrogen production. New clean coal conversion processes were designed and tested for coproducing clean pitches and cokes used in the metals industry as well as a heavy crude oil. These new processes were based on direct liquefaction and pyrolysis techniques that liberate volatile liquids from coal without the need for high pressure or on-site gaseous hydrogen. As a result of the research, a commercial scale plant for the production of synthetic foundry coke has broken ground near Wise, Virginia under the auspices of Carbonite Inc. This plant will produce foundry coke by pyrolyzing a blend of steam coal feedstocks. A second plant is planned by Quantex Energy Inc (in Texas) which will use solvent extraction to coproduce a coke residue as well as crude oil. A third plant is being actively considered for Kingsport, Tennessee, pending a favorable resolution of regulatory issues.

  14. Carbonate phosphonium salts as catalysts for the transesterification of dialkyl carbonates with diols. The competition between cyclic carbonates and linear dicarbonate products.

    Science.gov (United States)

    Selva, Maurizio; Caretto, Alessio; Noè, Marco; Perosa, Alvise

    2014-06-28

    At 90-120 °C, in the presence of methylcarbonate and bicarbonate methyltrioctylphosphonium salts as catalysts ([P8881][A]; [A] = MeOCO2 and HOCO2), the transesterification of non-toxic dimethyl- and diethyl-carbonate (DMC and DEC, respectively) with 1,X-diols (2 ≤ X ≤ 6) proceeds towards the formation of cyclic and linear products. In particular, 1,2-propanediol and ethylene glycol afford propylene- and ethylene-carbonate with selectivity and yields up to 95 and 90%, respectively; while, the reaction of DMC with higher diols such 1,3-butanediol, 2-methyl-1,3-propanediol, 1,3-propanediol, 2,2-dimethyl, 1,3-propanediol, 1,4-butanediol and 1,6-hexanediol produce linear C8-C10 dicarbonates of general formula MeOC(O)O∼∼∼OC(O)OMe as the almost exclusive products. Of note, these dicarbonate derivatives are not otherwise accessible in good yields by other conventional base catalyzed methods. Among 1,3-diols, the only exception was 2-methyl 2,4-pentandiol that yields the corresponding cyclic carbonate, i.e. 4,4,6-trimethyl-1,3-dioxan-2-one. In no one case, polycarbonates are observed. Such remarkable differences of product distributions are ascribed to the structure (branching and relative position of OH groups) of diols and to the role of cooperative (nucleophilic and electrophilic) catalysis which has been proved for onium salts. The investigated carbonate salts are not only effective in amounts as low as 0.5 mol%, but they are highly stable and recyclable.

  15. Potential methane production in thawing permafrost is constrained by methanogenic population size, carbon density, and substrate

    Science.gov (United States)

    Liebner, S.; Lehr, C.; Wagner, D.; Obu, J.; Lantuit, H.; Fritz, M.

    2016-12-01

    The release of carbon from newly thawed permafrost is estimated to add between 0.05 and 0.39 °C to the simulated global mean surface air temperature by the year 2300. The release of the potent greenhouse gas CH4 following permafrost thaw is thereby of particular concern. Models simulated a contribution of CH4 to the radiative forcing from thawing permafrost of up to 40% for the maximum extent of thermokarst (1). Batch experiments on thawed permafrost samples, however, have rendered the contribution of anaerobically produced carbon and in particular of CH4 to be surprisingly weak (2) and CH4 production which is realized through methanogenic archaea was reported to be low and associated with long lag phases . This leads to the hypotheses that initial methanogenic population sizes and/or substrates are limiting factors in permafrost. The objective of this study is to identify constraints for CH4 production in thawing permafrost. We analyzed several low Arctic permafrost cores of up to 3 m depth of different land cover types, sediment properties, age and stratigraphy for methanogenic abundance, potential methane production and predictors of both. We found that methanogenic population size and substrate pool are constraints on methane production but unlike expected, they do not fully explain low CH4 production rates in thawing permafrost. Even when both, population size and substrate concentrations, were large, the potential production of CH4 was still comparably low. Furthermore we show that the potential production of CH4 in thawing permafrost is a function of the methanogenic population size if substrate is not the limiting factor and that the methanogenic population size in turn is a function of the carbon density. Based on our study we propose that on the long term after permafrost has thawed, growth and community shifts within the methanogenic population will occur which potentially will increase methane production by orders of magnitude. 1. Schneider von

  16. Co-production of carbonic anhydrase and phycobiliproteins by Spirulina sp. and Synechococcus nidulans.

    Science.gov (United States)

    Ores, Joana da Costa; Amarante, Marina Campos Assumpção de; Kalil, Susana Juliano

    2016-11-01

    The aim of this work was to study the co-production of the carbonic anhydrase, C-phycocyanin and allophycocyanin during cyanobacteria growth. Spirulina sp. LEB 18 demonstrated a high potential for simultaneously obtaining the three products, achieving a carbonic anhydrase (CA) productivity of 0.97U/L/d and the highest C-phycocyanin (PC, 5.9μg/mL/d) and allophycocyanin (APC, 4.3μg/mL/d) productivities. In the extraction study, high extraction yields were obtained from Spirulina using an ultrasonic homogenizer (CA: 25.5U/g; PC: 90mg/g; APC: 70mg/g). From the same biomass, it was possible to obtain three biomolecules that present high industrial value.

  17. Carbonate and carbon fluctuations in the Eastern Arabian Sea over 140 ka: Implications on productivity changes?

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.; Naidu, P.D.; Haake, B.G.; Schiebel, R.

    orientation. ARTICLE IN PRESS Table1 Core depth, age, stable oxygen isotope data, linear sedimenta- tion rate (LSR), and calcite and organic carbon concentration ofsedimentcoreSL-1 Depth (cm) Age (kaBP) d 18 O (%) LSR (cm/ka) CaCO 3 (%) C org (%) 1 0.49 47....96 0.50 225 44.00 30.85 0.38 230 45.00 C00.49 5.02 33.34 0.49 235 45.99 32.38 0.73 240 46.99 C00.24 5.02 38.10 0.56 Table1(continued) Depth (cm) Age (kaBP) d 18 O (%) LSR (cm/ka) CaCO 3 (%) C org (%) 245 47.98 45.24 0.48 250 48.98 C00.50 5.02 45.10 0...

  18. Methane catalytic decomposition over ordered mesoporous carbons: A promising route for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Botas, J.A.; Serrano, D.P. [Department of Chemical and Environmental Technology, ESCET, Rey Juan Carlos University, c/ Tulipan s/n, 28933 Mostoles, Madrid (Spain); IMDEA Energia, c/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Guil-Lopez, R.; Pizarro, P.; Gomez, G. [Department of Chemical and Environmental Technology, ESCET, Rey Juan Carlos University, c/ Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2010-09-15

    Methane decomposition offers an interesting route for the CO{sub 2}-free hydrogen production. The use of carbon catalysts, in addition to lowering the reaction temperature, presents a number of advantages, such as low cost, possibility of operating under autocatalytic conditions and feasibility of using the produced carbons in non-energy applications. In this work, a novel class of carbonaceous materials, having an ordered mesoporous structure (CMK-3 and CMK-5), has been checked as catalysts for methane decomposition, the results obtained being compared to those corresponding to a carbon black sample (CB-bp) and two activated carbons, presenting micro- (AC-mic) and mesoporosity (AC-mes), respectively. Ordered mesoporous carbons, and especially CMK-5, possess a remarkable activity and stability for the hydrogen production through that reaction. Under both temperature programmed and isothermal experiments, CMK-5 has shown to be a superior catalyst for methane decomposition than the AC-mic and CB-bp materials. Likewise, the catalytic activity of CMK-5 is superior to that of AC-mes in spite of the presence of mesoporosity and a high surface area in the latter. The remarkable stability of the CMK-5 catalyst is demonstrated by the high amount of carbon deposits that can be formed on this sample. This result has been assigned to the growth of the carbon deposits from methane decomposition towards the outer part of the catalyst particles, avoiding the blockage of the uniform mesopores present in CMK-5. Thus, up to 25 g of carbon deposits have been formed per gram of CMK-5, while the latter still retains a significant catalytic activity. (author)

  19. Hydrogen and Carbon Black Production from Thermal Decomposition of Sub-Quality Natural Gas

    Directory of Open Access Journals (Sweden)

    M. Javadi

    2010-03-01

    Full Text Available The objective of this paper is computational investigation of the hydrogen and carbon black production through thermal decomposition of waste gases containing CH4 and H2S, without requiring a H2S separation process. The chemical reaction model, which involves solid carbon, sulfur compounds and precursor species for the formation of carbon black, is based on an assumed Probability Density Function (PDF parameterized by the mean and variance of mixture fraction and β-PDF shape. The effects of feedstock mass flow rate and reactor temperature on hydrogen, carbon black, S2, SO2, COS and CS2 formation are investigated. The results show that the major factor influencing CH4 and H2S conversions is reactor temperature. For temperatures higher than 1100° K, the reactor CH4 conversion reaches 100%, whilst H2S conversion increases in temperatures higher than 1300° K. The results reveal that at any temperature, H2S conversion is less than that of CH4. The results also show that in the production of carbon black from sub-quality natural gas, the formation of carbon monoxide, which is occurring in parallel, play a very significant role. For lower values of feedstock flow rate, CH4 mostly burns to CO and consequently, the production of carbon black is low. The results show that the yield of hydrogen increases with increasing feedstock mass flow rate until the yield reaches a maximum value, and then drops with further increase in the feedstock mass flow rate.

  20. Biotechnological Production of Docosahexaenoic Acid Using Aurantiochytrium limacinum: Carbon Sources Comparison And Growth Characterization

    Directory of Open Access Journals (Sweden)

    Sergi Abad

    2015-12-01

    Full Text Available Aurantiochytrium limacinum, a marine heterotrophic protist/microalga has shown interesting yields of docosahexaenoic acid (DHA when cultured with different carbon sources: glucose, pure and crude glycerol. A complete study in a lab-scale fermenter allowed for the characterization and comparison of the growth kinetic parameters corresponding to each carbon source. Artificial Marine Medium (AMM with glucose, pure and crude glycerol offered similar biomass yields. The net growth rates (0.10–0.12 h−1, biomass (0.7–0.8 g cells/g Substrate and product (0.14–0.15 g DHA/g cells yields, as well as DHA productivity were similar using the three carbon sources. Viable potential applications to valorize crude glycerol are envisioned to avoid an environmental problem due to the excess of byproduct.

  1. CHARACTERIZATION OF PRODUCTION-INDUCED DEFECTS IN CARBON FIBER REINFORCED THERMOPLASTIC TECHNOLOGY

    OpenAIRE

    Fischer, Frederic; Mezakeu Tongnan, Yannick; Beyrle, Matthias; Gerngroß, Tobias; Kupke, Michael

    2015-01-01

    Advanced thermoplastic composites such as carbon fibre reinforced polyetheretherketone (CF-PEEK) have a great potential for efficient processing. Along the production chain certain manufacturing steps may cause slight, superficial flaws or mere optical effects without greater impact on performance whereas others may lead to severe changes of the final part properties. These production–induced defects can arise already in the early stages of the production chain and may hence cause significant...

  2. Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) Users’ Manual and Technical Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Qin, Zhangcai [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Mueller, Steffen [Univ. of Illinois, Chicago, IL (United States). Energy Resources Center; Kwon, Ho-young [International Food Policy Research Institute (IFPRI), Washington, DC (United States); Wander, Michelle M. [Univ. of Illinois at Urbana Champaign, Urbana, IL (United States). Dept. of Natural Resources; Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

    2016-09-01

    The $\\underline{C}$arbon $\\underline{C}$alculator for $\\underline{L}$and $\\underline{U}$se Change from $\\underline{B}$iofuels Production (CCLUB) calculates carbon emissions from land use change (LUC) for four different ethanol production pathways including corn grain ethanol and cellulosic ethanol from corn stover, Miscanthus, and switchgrass. This document discusses the version of CCLUB released September 30, 2014 which includes corn and three cellulosic feedstocks: corn stover, Miscanthus, and switchgrass.

  3. Method to assess the carbon footprint at product level in the dairy industry

    DEFF Research Database (Denmark)

    Flysjö, Anna Maria; Thrane, Mikkel; Hermansen, John Erik

    2014-01-01

    associated with raw milk are allocated based on a weighted fat and protein content (1:1.4). Data from the dairy company Arla Foods give 1.1, 8.1, 6.5, 7.4 and 1.2 kg carbon dioxide equivalents per kg of fresh dairy product, butter and butter blend, cheese, milk powder and whey based product, and other...

  4. Studying the Early Stages of Protein Aggregation Using Replica Exchange Molecular Dynamics Simulations.

    Science.gov (United States)

    Shea, Joan-Emma; Levine, Zachary A

    2016-01-01

    The simulation of protein aggregation poses several computational challenges due to the disparate time and lengths scales that are involved. This chapter focuses on the use of atomistically detailed simulations to probe the initial steps of aggregation, with an emphasis on the Tau peptide as a model system, run under a replica exchange molecular dynamics protocol.

  5. Enhanced conformational sampling of carbohydrates by Hamiltonian replica-exchange simulation.

    Science.gov (United States)

    Mishra, Sushil Kumar; Kara, Mahmut; Zacharias, Martin; Koca, Jaroslav

    2014-01-01

    Knowledge of the structure and conformational flexibility of carbohydrates in an aqueous solvent is important to improving our understanding of how carbohydrates function in biological systems. In this study, we extend a variant of the Hamiltonian replica-exchange molecular dynamics (MD) simulation to improve the conformational sampling of saccharides in an explicit solvent. During the simulations, a biasing potential along the glycosidic-dihedral linkage between the saccharide monomer units in an oligomer is applied at various levels along the replica runs to enable effective transitions between various conformations. One reference replica runs under the control of the original force field. The method was tested on disaccharide structures and further validated on biologically relevant blood group B, Lewis X and Lewis A trisaccharides. The biasing potential-based replica-exchange molecular dynamics (BP-REMD) method provided a significantly improved sampling of relevant conformational states compared with standard continuous MD simulations, with modest computational costs. Thus, the proposed BP-REMD approach adds a new dimension to existing carbohydrate conformational sampling approaches by enhancing conformational sampling in the presence of solvent molecules explicitly at relatively low computational cost.

  6. Combining Elastic Network Analysis and Molecular Dynamics Simulations by Hamiltonian Replica Exchange.

    Science.gov (United States)

    Zacharias, Martin

    2008-03-01

    Coarse-grained elastic network models (ENM) of proteins can be used efficiently to explore the global mobility of a protein around a reference structure. A new Hamiltonian-replica exchange molecular dynamics (H-RexMD) method has been designed that effectively combines information extracted from an ENM analysis with atomic-resolution MD simulations. The ENM analysis is used to construct a distance-dependent penalty (flooding or biasing) potential that can drive the structure away from its current conformation in directions compatible with the ENM model. Various levels of the penalty or biasing potential are added to the force field description of the MD simulation along the replica coordinate. One replica runs at the original force field. By focusing the penalty potential on the relevant soft degrees of freedom the method avoids the rapid increase of the replica number with increasing system size to cover a desired temperature range in conventional (temperature) RexMD simulations. The application to domain motions in lysozyme of bacteriophage T4 and to peptide folding indicates significantly improved conformational sampling compared to conventional MD simulations.

  7. Nickel replicas as calibration reference standards for industrial surface texture instruments

    DEFF Research Database (Denmark)

    Sammatini-Malberg, Maria-Pia

    The present report is a documentation of measurements carried out at DTU on Nickel replicas. The research is performed in the frame of the project with contract SMT4-CT97-2176 with title: Calibration Standards for Surface Topography Measuring Systems down to Nanometric Scale....

  8. Investigation of the Airflow inside Realistic and Semi-Realistic Replicas of Human Airways

    Directory of Open Access Journals (Sweden)

    Lizal Frantisek

    2015-01-01

    Full Text Available Measurement of velocity in human lungs during breathing cycle is a challenging task for researchers, since the measuring location is accessible only with significant difficulties. A special measuring rig consisting of optically transparent replica of human lungs, breathing simulator, particle generator and Laser-Doppler anemometer was developed and used for investigation of the velocity in specific locations of lungs during simulated breathing cycle. Experiments were performed on two different replicas of human lungs in corresponding measuring points to facilitate the analysis of the influence of the geometry and its simplification on the flow. The analysis of velocity course and turbulence intensity revealed that special attention should be devoted to the modelling of vocal cords position during breathing, as the position of laryngeal jet created by vocal cords significantly influences velocity profiles in trachea. The shapes of velocity courses during expiration proved to be consistent for both replicas; however magnitudes of peak expiratory velocity differ between the corresponding measuring points in both the replicas.

  9. Exploring Replica-Exchange Wang-Landau sampling in higher-dimensional parameter space

    Science.gov (United States)

    Valentim, Alexandra; Rocha, Julio C. S.; Tsai, Shan-Ho; Li, Ying Wai; Eisenbach, Markus; Fiore, Carlos E.; Landau, David P.

    2015-09-01

    We considered a higher-dimensional extension for the replica-exchange Wang- Landau algorithm to perform a random walk in the energy and magnetization space of the two-dimensional Ising model. This hybrid scheme combines the advantages of Wang-Landau and Replica-Exchange algorithms, and the one-dimensional version of this approach has been shown to be very efficient and to scale well, up to several thousands of computing cores. This approach allows us to split the parameter space of the system to be simulated into several pieces and still perform a random walk over the entire parameter range, ensuring the ergodicity of the simulation. Previous work, in which a similar scheme of parallel simulation was implemented without using replica exchange and with a different way to combine the result from the pieces, led to discontinuities in the final density of states over the entire range of parameters. From our simulations, it appears that the replica-exchange Wang-Landau algorithm is able to overcome this difficulty, allowing exploration of higher parameter phase space by keeping track of the joint density of states.

  10. Exploring Replica-Exchange Wang-Landau sampling in higher-dimensional parameter space

    Energy Technology Data Exchange (ETDEWEB)

    Valentim, Alexandra [University of Georgia, Athens, GA; Rocha, Julio C. S. [Universidade Federal de Minas Gerais; Tsai, Shan-Ho [University of Georgia, Athens, GA; Li, Ying Wai [ORNL; Eisenbach, Markus [ORNL; Fiore, Carlos E [University of Sao Paulo, BRAZIL; Landau, David P [University of Georgia, Athens, GA

    2015-01-01

    We considered a higher-dimensional extension for the replica-exchange Wang-Landau algorithm to perform a random walk in the energy and magnetization space of the two-dimensional Ising model. This hybrid scheme combines the advantages of Wang-Landau and Replica-Exchange algorithms, and the one-dimensional version of this approach has been shown to be very efficient and to scale well, up to several thousands of computing cores. This approach allows us to split the parameter space of the system to be simulated into several pieces and still perform a random walk over the entire parameter range, ensuring the ergodicity of the simulation. Previous work, in which a similar scheme of parallel simulation was implemented without using replica exchange and with a different way to combine the result from the pieces, led to discontinuities in the final density of states over the entire range of parameters. From our simulations, it appears that the replica-exchange Wang-Landau algorithm is able to overcome this diculty, allowing exploration of higher parameter phase space by keeping track of the joint density of states.

  11. Exploring Replica-Exchange Wang-Landau sampling in higher-dimensional parameter space

    CERN Document Server

    Valentim, Alexandra; Tsai, Shan-Ho; Li, Ying Wai; Eisenbach, Markus; Fiore, Carlos E; Landau, David P

    2015-01-01

    We considered a higher-dimensional extension for the replica-exchange Wang-Landau algorithm to perform a random walk in the energy and magnetization space of the two-dimensional Ising model. This hybrid scheme combines the advantages of Wang-Landau and Replica-Exchange algorithms, and the one-dimensional version of this approach has been shown to be very efficient and to scale well, up to several thousands of computing cores. This approach allows us to split the parameter space of the system to be simulated into several pieces and still perform a random walk over the entire parameter range, ensuring the ergodicity of the simulation. Previous work, in which a similar scheme of parallel simulation was implemented without using replica exchange and with a different way to combine the result from the pieces, led to discontinuities in the final density of states over the entire range of parameters. From our simulations, it appears that the replica-exchange Wang-Landau algorithm is able to overcome this difficulty,...

  12. Fast Optimal Replica Placement with Exhaustive Search Using Dynamically Reconfigurable Processor

    Directory of Open Access Journals (Sweden)

    Hidetoshi Takeshita

    2011-01-01

    Full Text Available This paper proposes a new replica placement algorithm that expands the exhaustive search limit with reasonable calculation time. It combines a new type of parallel data-flow processor with an architecture tuned for fast calculation. The replica placement problem is to find a replica-server set satisfying service constraints in a content delivery network (CDN. It is derived from the set cover problem which is known to be NP-hard. It is impractical to use exhaustive search to obtain optimal replica placement in large-scale networks, because calculation time increases with the number of combinations. To reduce calculation time, heuristic algorithms have been proposed, but it is known that no heuristic algorithm is assured of finding the optimal solution. The proposed algorithm suits parallel processing and pipeline execution and is implemented on DAPDNA-2, a dynamically reconfigurable processor. Experiments show that the proposed algorithm expands the exhaustive search limit by the factor of 18.8 compared to the conventional algorithm search limit running on a Neumann-type processor.

  13. Low-Carbon Fuel and Chemical Production by Anaerobic Gas Fermentation.

    Science.gov (United States)

    Daniell, James; Nagaraju, Shilpa; Burton, Freya; Köpke, Michael; Simpson, Séan Dennis

    World energy demand is expected to increase by up to 40% by 2035. Over this period, the global population is also expected to increase by a billion people. A challenge facing the global community is not only to increase the supply of fuel, but also to minimize fossil carbon emissions to safeguard the environment, at the same time as ensuring that food production and supply is not detrimentally impacted. Gas fermentation is a rapidly maturing technology which allows low carbon fuel and commodity chemical synthesis. Unlike traditional biofuel technologies, gas fermentation avoids the use of sugars, relying instead on gas streams rich in carbon monoxide and/or hydrogen and carbon dioxide as sources of carbon and energy for product synthesis by specialized bacteria collectively known as acetogens. Thus, gas fermentation enables access to a diverse array of novel, large volume, and globally available feedstocks including industrial waste gases and syngas produced, for example, via the gasification of municipal waste and biomass. Through the efforts of academic labs and early stage ventures, process scale-up challenges have been surmounted through the development of specialized bioreactors. Furthermore, tools for the genetic improvement of the acetogenic bacteria have been reported, paving the way for the production of a spectrum of ever-more valuable products via this process. As a result of these developments, interest in gas fermentation among both researchers and legislators has grown significantly in the past 5 years to the point that this approach is now considered amongst the mainstream of emerging technology solutions for near-term low-carbon fuel and chemical synthesis.

  14. Methane production by Methanothermobacter thermautotrophicus to recover energy from carbon dioxide sequestered in geological reservoirs.

    Science.gov (United States)

    Kawaguchi, Hideo; Sakuma, Takahiro; Nakata, Yuiko; Kobayashi, Hajime; Endo, Keita; Sato, Kozo

    2010-07-01

    To recover energy from carbon dioxide sequestered in geological reservoirs, the geochemical effects of acidic and substrate- and nutrient-limiting conditions on methane production by the hydrogenotrophic methanogen Methanothermobacter thermautotrophicus were investigated in a simulated deep saline aquifer environment using formation water media retrieved from petroleum reservoirs.

  15. Regional impacts of climate change and elevated carbon dioxide on forest productivity

    Science.gov (United States)

    Jennifer C. Jenkins; David W. Kicklighter; John D. Aber

    2000-01-01

    Net primary production (NPP) is defined as the rate at which carbon (C) is accumulated by autotrophs and is expressed as the difference between gross photosynthesis and autotrophic respiration. NPP is the resource providing for the growth and reproduction of all heterotrophs on Earth; as a result, it determines the planet's carrying capacity (Vitousek et al., 1986...

  16. Lignin depolymerisation in supercritical carbon dioxide/acetone/water fluid for the production of aromatic chemicals

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Teunissen, W.; Dam, van J.E.G.; Jong, de E.; Gellerstedt, G.; Scott, E.L.; Sanders, J.P.M.

    2012-01-01

    Valorisation of lignin plays a key role in further development of lignocellulosic biorefinery processes the production of biofuels and bio-based materials. In the present study, organosolv hardwood and wheat straw lignins were converted in a supercritical fluid consisting of carbon dioxide/acetone/w

  17. Linking carbon stock change from land-use change to consumption of agricultural products: Alternative perspectives

    NARCIS (Netherlands)

    Goh, Chun Sheng; Wicke, Birka; Faaij, André; Bird, David Neil; Schwaiger, Hannes; Junginger, Martin

    2016-01-01

    Abstract Agricultural expansion driven by growing demand has been a key driver for carbon stock change as a consequence of land-use change (CSC-LUC). However, its relative role compared to non-agricultural and non-productive drivers, as well as propagating effects were not clearly addressed. This st

  18. Forbs enhance productivity of unfertilised grass-clover leys and support low-carbon bioenergy

    DEFF Research Database (Denmark)

    Cong, Wen-Feng; Jing, Jingying; Rasmussen, Jim

    2017-01-01

    achieved the 60% reduction in GHG emissions compared to fossil fuel, whereas all fertilised mixtures did not meet the 60% reduction target. These findings suggest that including competitive forbs such as plantain in grass-clover mixtures enhances productivity, supporting low-carbon footprint bioenergy...

  19. Managing forests because carbon matters: integrating energy, products, and land management policy

    Science.gov (United States)

    Robert W. Malmsheimer; James L. Bowyer; Jeremy S. Fried; Edmund Gee; Robert Izlar; Reid A. Miner; Ian A. Munn; Elaine Oneil; William C. Stewart

    2011-01-01

    The United States needs many different types of forests: some managed for wood products plus other benefits, and some managed for nonconsumptive uses and benefits. The objective of reducing global greenhouse gases (GHG) requires increasing carbon storage in pools other than the atmosphere. Growing more forests and keeping forests as forests are only part of the...

  20. The influence of carbon sources and morphology on nystatin production by Streptomyces noursei

    DEFF Research Database (Denmark)

    Jonsbu, E.; Mcintyre, Mhairi; Nielsen, Jens

    2002-01-01

    Carbon source nutrition and morphology were examined during cell growth and production of nystatin by Streptomyces noursei ATCC 11455. This strain was able to utilise glucose, fructose, glycerol and soluble starch for cell growth, but failed to grow on media supplemented with galactose, xylose...

  1. Greenhouse gas and carbon profile of the U.S. forest products industry value chain

    Science.gov (United States)

    Linda S. Heath; Van Maltby; Reid Miner; Kenneth E. Skog; James E. Smith; Jay Unwin; Brad Upton

    2010-01-01

    A greenhouse gas and carbon accounting profile was developed for the U.S. forest products industry value chain for 1990 and 2004-2005 by examining net atmospheric fluxes of CO2 and other greenhouse gases (GHGs) using a variety of methods and data sources. Major GHG emission sources include direct and indirect (from purchased electricity...

  2. Assessing the environmental impact of energy production from hydrochar generated via hydrothermal carbonization of food wastes.

    Science.gov (United States)

    Berge, Nicole D; Li, Liang; Flora, Joseph R V; Ro, Kyoung S

    2015-09-01

    Although there are numerous studies suggesting hydrothermal carbonization is an environmentally advantageous process for transformation of wastes to value-added products, a systems level evaluation of the environmental impacts associated with hydrothermal carbonization and subsequent hydrochar combustion has not been conducted. The specific objectives of this work are to use a life cycle assessment approach to evaluate the environmental impacts associated with the HTC of food wastes and the subsequent combustion of the generated solid product (hydrochar) for energy production, and to understand how parameters and/or components associated with food waste carbonization and subsequent hydrochar combustion influence system environmental impact. Results from this analysis indicate that HTC process water emissions and hydrochar combustion most significantly influence system environmental impact, with a net negative GWP impact resulting for all evaluated substituted energy-sources except biomass. These results illustrate the importance of electricity production from hydrochar particularly when it is used to offset coal-based energy sources. HTC process water emissions result in a net impact to the environment, indicating a need for developing appropriate management strategies. Results from this analysis also highlight a need for additional exploration of liquid and gas-phase composition, a better understanding of how changes in carbonization conditions (e.g., reaction time and temperature) influence metal and nutrient fate, and the exploration of liquid-phase treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Measurements of π{sup ±} differential yields from the surface of the T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, N.; Ajaz, M.; Blondel, A.; Bravar, A.; Debieux, S.; Haesler, A.; Korzenev, A.; Ravonel, M. [University of Geneva, Geneva (Switzerland); Aduszkiewicz, A.; Dominik, W.; Kuich, M.; Matulewicz, T.; Posiadala-Zezula, M. [University of Warsaw, Warsaw (Poland); Ali, Y. [Jagiellonian University, Cracow (Poland); COMSATS Institute of Information Technology, Department of Physics, Islamabad (Pakistan); Andronov, E.; Feofilov, G.A.; Igolkin, S.; Kondratiev, V.P.; Seryakov, A.; Vechernin, V.V.; Vinogradov, L. [St. Petersburg State University, Saint Petersburg (Russian Federation); Anticic, T.; Kadija, K.; Susa, T. [Ruder Boskovic Institute, Zagreb (Croatia); Antoniou, N.; Christakoglou, P.; Davis, N.; Diakonos, F.; Kapoyannis, A.; Panagiotou, A.D.; Vassiliou, M. [University of Athens, Athens (Greece); Baatar, B.; Bunyatov, S.A.; Kolesnikov, V.I.; Krasnoperov, A.; Lyubushkin, V.V.; Malakhov, A.I.; Matveev, V.; Melkumov, G.L.; Tereshchenko, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Bay, F.; Di Luise, S.; Rubbia, A.; Sgalaberna, D. [ETH Zuerich, Zuerich (Switzerland); Bluemer, J.; Dembinski, H.; Engel, R.; Herve, A.E.; Mathes, H.J.; Roth, M.; Szuba, M.; Ulrich, R.; Unger, M.; Veberic, D. [Karlsruhe Institute of Technology, Karlsruhe (Germany); Bogomilov, M.; Kolev, D.; Tsenov, R. [University of Sofia, Faculty of Physics, Sofia (Bulgaria); Brandin, A.; Selyuzhenkov, I.; Taranenko, A. [National Research Nuclear University ' ' MEPhI' ' (Moscow Engineering Physics Institute), Moscow (Russian Federation); Brzychczyk, J.; Larsen, D.; Planeta, R.; Richter-Was, E.; Staszel, P.; Wyszynski, O. [Jagiellonian University, Cracow (Poland); Busygina, O.; Golubeva, M.; Guber, F.; Ivashkin, A.; Kurepin, A.; Sadovsky, A. [Institute for Nuclear Research, Moscow (Russian Federation); Cirkovic, M.; Manic, D.; Puzovic, J. [University of Belgrade, Belgrade (Serbia); Czopowicz, T.; Dynowski, K.; Grebieszkow, K.; Mackowiak-Pawlowska, M.; Maksiak, B.; Sarnecki, R.; Slodkowski, M.; Tefelska, A.; Tefelski, D. [Warsaw University of Technology, Warsaw (Poland); Deveaux, M.; Koziel, M.; Renfordt, R.; Stroebele, H. [University of Frankfurt, Frankfurt (Germany); Dumarchez, J.; Robert, A. [LPNHE, University of Paris VI and VII, Paris (France); Ereditato, A.; Hierholzer, M.; Nirkko, M.; Pistillo, C.; Redij, A. [University of Bern, Bern (Switzerland); Fodor, Z. [Wigner Research Centre for Physics of the Hungarian Academy of Sciences, Budapest (Hungary); University of Wroclaw, Wroclaw (Poland); Garibov, A. [National Nuclear Research Center, Baku (Azerbaijan); Gazdzicki, M. [University of Frankfurt, Frankfurt (Germany); Jan Kochanowski University in Kielce, Kielce (Poland); Grzeszczuk, A.; Kaptur, E.; Kisiel, J.; Kowalski, S.; Pulawski, S.; Schmidt, K.; Wilczek, A. [University of Silesia, Katowice (Poland); Hasegawa, T.; Kobayashi, T.; Nakadaira, T.; Nishikawa, K.; Sakashita, K.; Sekiguchi, T.; Shibata, M.; Tada, M.; Friend, M. [Institute for Particle and Nuclear Studies, Tsukuba (Japan); Johnson, S.R.; Marino, A.D.; Rumberger, B.T.; Zimmerman, E.D. [University of Colorado, Boulder (United States); Kowalik, K.; Rondio, E.; Stepaniak, J. [National Centre for Nuclear Research, Warsaw (Poland); Laszlo, A.; Marton, K.; Vesztergombi, G. [Wigner Research Centre for Physics of the Hungarian Academy of Sciences, Budapest (Hungary); Lewicki, M.; Naskret, M.; Turko, L. [University of Wroclaw, Wroclaw (Poland); Marcinek, A. [Jagiellonian University, Cracow (Poland); University of Wroclaw, Wroclaw (PL); Messerly, B.; Nagai, Y.; Paolone, V. [University of Pittsburgh, Pittsburgh (US); Mills, G.B.; Yarritu, K. [Los Alamos National Laboratory, Los Alamos (US); Morozov, S.; Petukhov, O. [Institute for Nuclear Research, Moscow (RU); National Research Nuclear University ' ' MEPhI' ' (Moscow Engineering Physics Institute), Moscow (RU); Mrowczynski, S.; Rybczynski, M.; Seyboth, P.; Stefanek, G.; Wlodarczyk, Z.; Wojtaszek-Szwarc, A. [Jan Kochanowski University in Kielce, Kielce (PL); Pavin, M. [Ruder Boskovic Institute, Zagreb (HR); LPNHE, University of Paris VI and VII, Paris (FR); Popov, B.A. [LPNHE, University of Paris VI and VII, Paris (FR); Joint Institute for Nuclear Research, Dubna (RU); Rauch, W. [Fachhochschule Frankfurt, Frankfurt (DE); Roehrich, D. [University of Bergen, Bergen (NO); Rustamov, A. [National Nuclear Research Center, Baku (AZ); University of Frankfurt, Frankfurt (DE); Zambelli, L. [LPNHE, University of Paris VI and VII, Paris (FR); Institute for Particle and Nuclear Studies, Tsukuba (JP); Galymov, V. [IPNL, University of Lyon, Villeurbanne (FR); Hartz, M. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba (JP); TRIUMF, Vancouver, BC (CA); Hiraki, T.; Ichikawa, A.; Kubo, H.; Matsuoka, K.; Murakami, A.; Nakaya, T.; Suzuki, K. [Kyoto University, Department of Physics, Kyoto (JP); Tzanov, M. [Louisiana State University, Department of Physics and Astronomy, Baton Rouge, LA (US); Yu, M. [York University, Department of Physics and Astronomy, Toronto, ON (CA); Collaboration: NA61/SHINE Collaboration

    2016-11-15

    Measurements of particle emission from a replica of the T2K 90 cm-long carbon target were performed in the NA61/SHINE experiment at CERN SPS, using data collected during a high-statistics run in 2009. An efficient use of the long-target measurements for neutrino flux predictions in T2K requires dedicated reconstruction and analysis techniques. Fully-corrected differential yields of π{sup ±}-mesons from the surface of the T2K replica target for incoming 31 GeV/c protons are presented. A possible strategy to implement these results into the T2K neutrino beam predictions is discussed and the propagation of the uncertainties of these results to the final neutrino flux is performed. (orig.)

  4. Measurements of charged pion differential yields from the surface of the T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS

    CERN Document Server

    Abgrall, N; Ajaz, M; Ali, Y; Andronov, E; Anticic, T; Antoniou, N; Baatar, B; Bay, F; Blondel, A; Blümer, J; Bogomilov, M; Brandin, A; Bravar, A; Brzychczyk, J; Bunyatov, S A; Busygina, O; Christakoglou, P; Cirkovic, M; Czopowicz, T; Davis, N; Debieux, S; Dembinski, H; Deveaux, M; Diakonos, F; Di Luise, S; Dominik, W; Dumarchez, J; Dynowski, K; Engel, R; Ereditato, A; Feofilov, G A; Fodor, Z; Garibov, A; Gazdzicki, M; Golubeva, M; Grebieszkow, K; Grzeszczuk, A; Guber, F; Haesler, A; Hasegawa, T; Hervé, A E; Hierholzer, M; Igolkin, S; Ivashkin, A; Johnson, S R; Kadija, K; Kapoyannis, A; Kaptur, E; Kisiel, J; Kobayashi, T; Kolesnikov, V I; Kolev, D; Kondratiev, V P; Korzenev, A; Kowalik, K; Kowalski, S; Koziel, M; Krasnoperov, A; Kuich, M; Kurepin, A; Larsen, D; László, A; Lewicki, M; Lyubushkin, V V; Mackowiak-Pawłowska, M; Maksiak, B; Malakhov, A I; Manic, D; Marcinek, A; Marino, A D; Marton, K; Mathes, H -J; Matulewicz, T; Matveev, V; Melkumov, G L; Messerly, B; Mills, G B; Morozov, S; Mrówczynski, S; Nagai, Y; Nakadaira, T; Naskret, M; Nirkko, M; Nishikawa, K; Panagiotou, A D; Paolone, V; Pavin, M; Petukhov, O; Pistillo, C; Płaneta, R; Popov, B A; Posiadała-Zezula, M; Puławski, S; Puzovic, J; Rauch, W; Ravonel, M; Redij, A; Renfordt, R; Richter-Was, E; Robert, A; Röhrich, D; Rondio, E; Roth, M; Rubbia, A; Rumberger, B T; Rustamov, A; Rybczynski, M; Sadovsky, A; Sakashita, K; Sarnecki, R; Schmidt, K; Sekiguchi, T; Selyuzhenkov, I; Seryakov, A; Seyboth, P; Sgalaberna, D; Shibata, M; Słodkowski, M; Staszel, P; Stefanek, G; Stepaniak, J; Ströbele, H; Šuša, T; Szuba, M; Tada, M; Taranenko, A; Tefelska, A; Tefelski, D; Tereshchenko, V; Tsenov, R; Turko, L; Ulrich, R; Unger, M; Vassiliou, M; Veberic, D; Vechernin, V V; Vesztergombi, G; Vinogradov, L; Wilczek, A; Włodarczyk, Z; Wojtaszek-Szwarc, A; Wyszynski, O; Yarritu, K; Zambelli, L; Zimmerman, E D; Friend, M; Galymov, V; Hartz, M; Hiraki, T; Ichikawa, A; Kubo, H; Matsuoka, K; Murakami, A; Nakaya, T; Suzuki, K; Tzanov, M; Yu, M

    2016-01-01

    Measurements of particle emission from a replica of the T2K 90 cm-long carbon target were performed in the NA61/SHINE experiment at CERN SPS, using data collected during a high-statistics run in 2009. An efficient use of the long-target measurements for neutrino flux predictions in T2K requires dedicated reconstruction and analysis techniques. Fully-corrected differential yields of charged pions from the surface of the T2K replica target for incoming 31 GeV/c protons are presented. A possible strategy to implement these results into the T2K neutrino beam predictions is discussed and the propagation of the uncertainties of these results to the final neutrino flux is performed

  5. Measurements of π ^± differential yields from the surface of the T2K replica target for incoming 31 GeV/ c protons with the NA61/SHINE spectrometer at the CERN SPS

    Science.gov (United States)

    Abgrall, N.; Aduszkiewicz, A.; Ajaz, M.; Ali, Y.; Andronov, E.; Antićić, T.; Antoniou, N.; Baatar, B.; Bay, F.; Blondel, A.; Blümer, J.; Bogomilov, M.; Brandin, A.; Bravar, A.; Brzychczyk, J.; Bunyatov, S. A.; Busygina, O.; Christakoglou, P.; Ćirković, M.; Czopowicz, T.; Davis, N.; Debieux, S.; Dembinski, H.; Deveaux, M.; Diakonos, F.; Di Luise, S.; Dominik, W.; Dumarchez, J.; Dynowski, K.; Engel, R.; Ereditato, A.; Feofilov, G. A.; Fodor, Z.; Garibov, A.; Gaździcki, M.; Golubeva, M.; Grebieszkow, K.; Grzeszczuk, A.; Guber, F.; Haesler, A.; Hasegawa, T.; Hervé, A. E.; Hierholzer, M.; Igolkin, S.; Ivashkin, A.; Johnson, S. R.; Kadija, K.; Kapoyannis, A.; Kaptur, E.; Kisiel, J.; Kobayashi, T.; Kolesnikov, V. I.; Kolev, D.; Kondratiev, V. P.; Korzenev, A.; Kowalik, K.; Kowalski, S.; Koziel, M.; Krasnoperov, A.; Kuich, M.; Kurepin, A.; Larsen, D.; László, A.; Lewicki, M.; Lyubushkin, V. V.; Maćkowiak-Pawłowska, M.; Maksiak, B.; Malakhov, A. I.; Manić, D.; Marcinek, A.; Marino, A. D.; Marton, K.; Mathes, H.-J.; Matulewicz, T.; Matveev, V.; Melkumov, G. L.; Messerly, B.; Mills, G. B.; Morozov, S.; Mrówczyński, S.; Nagai, Y.; Nakadaira, T.; Naskręt, M.; Nirkko, M.; Nishikawa, K.; Panagiotou, A. D.; Paolone, V.; Pavin, M.; Petukhov, O.; Pistillo, C.; Płaneta, R.; Popov, B. A.; Posiadała-Zezula, M.; Puławski, S.; Puzović, J.; Rauch, W.; Ravonel, M.; Redij, A.; Renfordt, R.; Richter-Wąs, E.; Robert, A.; Röhrich, D.; Rondio, E.; Roth, M.; Rubbia, A.; Rumberger, B. T.; Rustamov, A.; Rybczynski, M.; Sadovsky, A.; Sakashita, K.; Sarnecki, R.; Schmidt, K.; Sekiguchi, T.; Selyuzhenkov, I.; Seryakov, A.; Seyboth, P.; Sgalaberna, D.; Shibata, M.; Słodkowski, M.; Staszel, P.; Stefanek, G.; Stepaniak, J.; Ströbele, H.; Šuša, T.; Szuba, M.; Tada, M.; Taranenko, A.; Tefelska, A.; Tefelski, D.; Tereshchenko, V.; Tsenov, R.; Turko, L.; Ulrich, R.; Unger, M.; Vassiliou, M.; Veberič, D.; Vechernin, V. V.; Vesztergombi, G.; Vinogradov, L.; Wilczek, A.; Włodarczyk, Z.; Wojtaszek-Szwarc, A.; Wyszyński, O.; Yarritu, K.; Zambelli, L.; Zimmerman, E. D.; Friend, M.; Galymov, V.; Hartz, M.; Hiraki, T.; Ichikawa, A.; Kubo, H.; Matsuoka, K.; Murakami, A.; Nakaya, T.; Suzuki, K.; Tzanov, M.; Yu, M.

    2016-11-01

    Measurements of particle emission from a replica of the T2K 90 cm-long carbon target were performed in the NA61/SHINE experiment at CERN SPS, using data collected during a high-statistics run in 2009. An efficient use of the long-target measurements for neutrino flux predictions in T2K requires dedicated reconstruction and analysis techniques. Fully-corrected differential yields of π ^± -mesons from the surface of the T2K replica target for incoming 31 GeV/ c protons are presented. A possible strategy to implement these results into the T2K neutrino beam predictions is discussed and the propagation of the uncertainties of these results to the final neutrino flux is performed.

  6. [Effects of mixed carbon sources on glucose oxidase production by recombinant Pichia pastoris].

    Science.gov (United States)

    Shen, Yina; Gu, Lei; Zhang, Juan; Chen, Jian; Du, Guocheng

    2013-07-01

    Glucose oxidase (GOD) is an important industrial enzyme with many potential applications. In order to increase the production and productivity of GOD by recombinant Pichia pastoris GS115, we investigated the feeding strategies of mixed carbon sources during induction phase, based on results of the optimization of initial cell and methanol concentration on GOD production. The optimal initial cell and methanol concentration were 100 g/L and 18 g/L. During induction phase, the mixed-carbon-sources strategies showed that glycerol, sorbitol or mannitol co-feeding with methanol could enhance GOD production. With mannitol co-feeding (20:1(W/W)), the maximum GOD production and maximum GOD productivity reached 711.3 U/mL and 4.60 U/(mL x h) after an induction period of 156 h. Compared to the control, the enhancements of GOD production and productivity were 66.3% and 67.9%, respectively. Meanwhile, we found an appropriate mannitol co-feeding strategy that would not inhibit the expression of promote. The activity of alcohol oxidase was 8.8 U/g, which was enhanced by 69.2% compared to the control (5.2 U/g). We can use the same optimization process to improve the production of other proteins from recombinant Pichia pastoris by changing the fermentation parameters.

  7. Biomass production and carbon sequestration potential in poplar plantations with different management patterns.

    Science.gov (United States)

    Fang, S; Xue, J; Tang, L

    2007-11-01

    Biomass production and carbon storage in short-rotation poplar plantations over 10 years were evaluated at the Hanyuan Forestry Farm, Baoying County, China. Experimental treatments applied in a split-plot design included four planting densities (1111, 833, 625 and 500 stems ha(-1)) and three poplar clones (NL-80351, I-69 and I-72). Based on the model of total biomass production developed, total plantation biomass production was significantly different in the plantations. The ranking of the plantation biomass production by planting density was 1111>833 more more than 625>500 stems ha(-1), and by components was stem>root>or=branch>leaf for all plantations. At 10 years, the highest total biomass in the plantation of 1111 stems ha(-1) reached about 146 t ha(-1), which was 5.3%, 11.6% and 24.2% higher than the plantations of 833, 625 and 500 stems ha(-1), respectively. The annual increment of biomass production over 10 years differed significantly among initial planting densities and stand ages (pplantation carbon storage by planting density was similar to that of total biomass production. At age 10, the highest total plantation carbon storage in the plantation of 1111 stems ha(-1) reached about 72.0 t ha(-1), which was 5.4%, 11.9% and 24.8% higher than in the plantations of 833, 625 and 500 stems ha(-1), respectively. The annual carbon storage increment over 10 years differed significantly among initial planting densities and stand ages (pplantations. The results suggest that biomass production and carbon storage potential were highest for planting densities of 1111 and 833 stems ha(-1) grown over 5- and 6-year cutting cycles, respectively. If 3- or 4-year cutting cycles are used, the planting density should be higher than 1111 stems ha(-1) (e.g., 1667 or 2500 stems ha(-1)). Based on the mean annual carbon storage for the plantation of 625 stems ha(-1), as an estimation, the mean carbon storage in the biomass of poplar plantations (excluding leaves) amounts to 3.75x10

  8. Is carbon monoxide-mediated cyclic guanosine monophosphate production responsible for low blood pressure in neonatal respiratory distress syndrome?

    NARCIS (Netherlands)

    van Bel, F; Latour, [No Value; Vreman, HJ; Wong, RJ; Stevenson, DK; Steendijk, P; Egberts, J; Krediet, TG

    Infant respiratory distress syndrome (RDS) involves inflammatory processes, causing an increased expression of inducible heme oxygenase with subsequent production of carbon monoxide (CO). We hypothesized that increased production of CO during RDS might be responsible for increased plasma levels of

  9. RESTORING SUSTAINABLE FORESTS ON APPALACHIAN MINED LANDS FOR WOOD PRODUCTS, RENEWABLE ENERGY, CARBON SEQUESTRATION, AND OTHER ECOSYSTEM SERVICES

    Energy Technology Data Exchange (ETDEWEB)

    J. Burger; J. Galbraith; T. Fox; G. Amacher; J. Sullivan; C. Zipper

    2003-12-18

    The overall purpose of this project is to evaluate the biological and economic feasibility of restoring high-quality forests on mined land, and to measure carbon sequestration and wood production benefits that would be achieved from forest restoration procedures. In this quarterly report, we present a preliminary comparison of the carbon sequestration benefits for two forest types used to convert abandoned grasslands for carbon sequestration. Annual mixed hardwood benefits, based on total stand carbon volume present at the end of a given year, range from a minimum of $0/ton of carbon to a maximum of $5.26/ton of carbon (low prices). White pine benefits based on carbon volume range from a minimum of $0/ton of carbon to a maximum of $18.61/ton of carbon (high prices). The higher maximum white pine carbon payment can primarily be attributed to the fact that the shorter rotation means that payments for white pine carbon are being made on far less cumulative carbon tonnage than for that of the long-rotation hardwoods. Therefore, the payment per ton of white pine carbon needs to be higher than that of the hardwoods in order to render the conversion to white pine profitable by the end of a rotation. These carbon payments may seem appealingly low to the incentive provider. However, payments (not discounted) made over a full rotation may add up to approximately $17,493/ha for white pine (30-year rotation), and $18,820/ha for mixed hardwoods (60-year rotation). The literature suggests a range of carbon sequestration costs, from $0/ton of carbon to $120/ton of carbon, although the majority of studies suggest a cost below $50/ ton of carbon, with van Kooten et al. (2000) suggesting a cutoff cost of $20/ton of carbon sequestered. Thus, the ranges of carbon payments estimated for this study fall well within the ranges of carbon sequestration costs estimated in previous studies.

  10. Significance of the carbonization of volatile pyrolytic products on the properties of activated carbons from phosphoric acid activation of lignocellulosic material

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Songlin; Yang, Jianxiao; Cai, Xuan [Faculty of Chemical Engineering, Nanjing Forestry University, Nanjing 210037 (China); Liu, Junli [Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042 (China)

    2009-07-15

    Two series of activated carbons derived from China fir (Cunninghamia lanceolata) wood impregnated with phosphoric acid were prepared in a cylindrical container that was kept in a closed state covered with a lid (the covered case) or in an open state. The effects of the carbonization of volatile pyrolytic products of starting materials on the properties of activated carbon were investigated in the process of phosphoric acid activation. Elemental analysis and SEM observation showed that both activating in the covered case and increasing the mass of starting material used favored the carbonization of volatile pyrolytic products. An investigation of N{sub 2} adsorption isotherms revealed that the carbonization of volatile pyrolytic products significantly enhanced mesopore development in the final carbons, especially pores with a size range from 2.5 to 30 nm, with little influence on micropores, and therefore produced a large increase in the adsorption capacity to Vitamin B12 (with a molecular size of 2.09 nm). Activated carbons with highly developed mesopores could be obtained in the covered case. The carbonization mechanism of volatiles was discussed and two different carbonization pathways (in solid and gas phases) were proposed during phosphoric acid activation. (author)

  11. CARBON COATED (CARBONOUS) CATALYST IN EBULLATED BED REACTOR FOR PRODUCTION OF OXYGENATED CHEMICALS FROM SYNGAS/CO2

    Energy Technology Data Exchange (ETDEWEB)

    Peizheng Zhou

    2001-10-26

    There are a number of exothermic chemical reactions which might benefit from the temperature control and freedom from catalyst fouling provided by the ebullated bed reactor technology. A particularly promising area is production of oxygenated chemicals, such as alcohols and ethers, from synthesis gas, which can be economically produced from coal or biomass. The ebullated bed operation requires that the small-diameter ({approx}1/32 inch) catalyst particles have enough mechanical strength to avoid loss by attrition. However, all of the State Of The Art (SOTA) catalysts and advanced catalysts for the purpose are low in mechanical strength. The patented carbon-coated catalyst technology developed in our laboratory converts catalyst particles with low mechanical strength to strong catalysts suitable for ebullated bed application. This R&D program is concerned with the modification on the mechanical strength of the SOTA and advanced catalysts so that the ebullated bed technology can be utilized to produce valuable oxygenated chemicals from syngas/CO{sub 2} efficiently and economically. The objective of this R&D program is to study the technical and economic feasibility of selective production of high-value oxygenated chemicals from synthesis gas and CO{sub 2} mixed feed in an ebullated bed reactor using carbon-coated catalyst particles.

  12. CARBON COATED (CARBONOUS) CATALYST IN EBULLATED BED REACTOR FOR PRODUCTION OF OXYGENATED CHEMICALS FROM SYNGAS/CO2

    Energy Technology Data Exchange (ETDEWEB)

    Peizheng Zhou

    2000-11-17

    There are a number of exothermic chemical reactions which might benefit from the temperature control and freedom from catalyst fouling provided by the ebullated bed reactor technology. A particularly promising area is production of oxygenated chemicals, such as alcohols and ethers, from synthesis gas, which can be economically produced from coal or biomass. The ebullated bed operation requires that the small-diameter ({approx} 1/32 inch) catalyst particles have enough mechanical strength to avoid loss by attrition. However, all of the State Of The Art (SOTA) catalysts and advanced catalysts for the purpose are low in mechanical strength. The patented carbon-coated catalyst technology developed in our laboratory converts catalyst particles with low mechanical strength to strong catalysts suitable for ebullated bed application. This R&D program is concerned with the modification on the mechanical strength of the SOTA and advanced catalysts so that the ebullated bed technology can be utilized to produce valuable oxygenated chemicals from syngas/CO{sub 2} efficiently and economically. The objective of this R&D program is to study the technical and economic feasibility of selective production of high-value oxygenated chemicals from synthesis gas and CO{sub 2} mixed feed in an ebullated bed reactor using carbon-coated catalyst particles.

  13. Gas-phase production of single-walled carbon nanotubes from carbon monoxide: a review of the hipco process

    Science.gov (United States)

    Nikolaev, Pavel

    2004-01-01

    The latest process for producing large quantities of single-walled carbon nanotubes (SWNTs) to emerge from the Rice University, dubbed HiPco, is living up to its promise. The current production rates approach 450 mg/h (or 10 g/day), and nanotubes typically have no more than 7 mol % of iron impurities. Second-generation HiPco apparatus can run continuously for 7-10 days at a time. In the HiPco process nanotubes grow in high-pressure, high-temperature flowing CO on catalytic clusters of iron. Catalyst is formed in situ by thermal decomposition of iron pentacarbonyl, which is delivered intact within a cold CO flow and then rapidly mixed with hot CO in the reaction zone. Upon heating, the Fe(CO)5 decomposes into atoms that condense into larger clusters. SWNTs nucleate and grow on these particles in the gas phase via CO disproportionation: CO + CO --> CO2 + C (SWNT), catalyzed by the Fe surface. The concentration of CO2 produced in this reaction is equal to that of carbon and can therefore serve as a useful real-time feedback parameter. It was used to study and optimize SWNT production as a function of temperature, pressure, and Fe(CO)5 concentration. The results of the parametric study are in agreement with current understanding of the nanotube formation mechanism.

  14. Chemical production from waste carbon monoxide: its potential for energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    Rohrmann, C.A.; Schiefelbein, G.F.; Molton, P.M.; Li, C.T.; Elliott, D.C.; Baker, E.G.

    1977-11-01

    Results of a study of the potential for energy conservation by producing chemicals from by-product or waste carbon monoxide (CO) from industrial sources are summarized. Extensive compilations of both industrial sources and uses for carbon monoxide were developed and included. Reviews of carbon monoxide purification and concentration technology and preliminary economic evaluations of carbon monoxide concentration, pipeline transportation and utilization of CO in the synthesis of ammonia and methanol are included. Preliminary technical and economic feasibility studies were made of producing ammonia and methanol from the by-product CO produced by a typical elemental phosphorus plant. Methanol synthesis appears to be more attractive than ammonia synthesis when using CO feedstock because of reduced water gas shift and carbon dioxide removal requirements. The economic studies indicate that methanol synthesis from CO appears to be competitive with conventional technology when the price of natural gas exceeds $0.82/million Btu, while ammonia synthesis from CO is probably not competitive until the price of natural gas exceeds $1.90/million Btu. It is concluded that there appears to be considerable potential for energy conservation in the chemical industry, by collecting CO rather than flaring it, and using it to make major chemicals such as ammonia and methanol.

  15. Soluble microbial products in pilot-scale drinking water biofilters with acetate as sole carbon source.

    Science.gov (United States)

    Zhang, Ying; Ye, Chengsong; Gong, Song; Wei, Gu; Yu, Xin; Feng, Lin

    2013-04-01

    A comprehensive study on formation and characteristics of soluble microbial products (SMP) during drinking water biofiltration was made in four parallel pilot-scale ceramic biofilters with acetate as the substrate. Excellent treatment performance was achieved while microbial biomass and acetate carbon both declined with the depth of filter. The SMP concentration was determined by calculating the difference between the concentration of dissolved organic carbon (DOC), biodegradable dissolved organic carbon (BDOC) and acetate carbon. The results revealed that SMP showed an obvious increase from 0 to 100 cm depth of the filter. A rising specific ultraviolet absorbance (SUVA) was also found, indicating that benzene or carbonyl might exist in these compounds. SMP produced during this drinking water biological process were proved to have weak mutagenicity and were not precursors of by-products of chlorination disinfection. The volatile parts of SMP were half-quantity analyzed and most of them were dicarboxyl acids, others were hydrocarbons or benzene with 16-17 carbon atoms.

  16. Synthesis and characterization of carbon cryogel microspheres from lignin-furfural mixtures for biodiesel production.

    Science.gov (United States)

    Zainol, Muzakkir Mohammad; Amin, Nor Aishah Saidina; Asmadi, Mohd

    2015-08-01

    The aim of this work was to study the potential of biofuel and biomass processing industry side-products as acid catalyst. The synthesis of carbon cryogel from lignin-furfural mixture, prepared via sol-gel polycondensation at 90°C for 0.5h, has been investigated for biodiesel production. The effect of lignin to furfural (L/F) ratios, lignin to water (L/W) ratios and acid concentration on carbon cryogel synthesis was studied. The carbon cryogels were characterized and tested for oleic acid conversion. The thermally stable amorphous spherical carbon cryogel has a large total surface area with high acidity. Experimental results revealed the optimum FAME yield and oleic acid conversion of 91.3wt.% and 98.1wt.%, respectively were attained at 65°C for 5h with 5wt.% catalyst loading and 20:1 methanol to oleic acid molar ratio. Therefore, carbon cryogel is highly potential for heterogeneous esterification of free fatty acid to biodiesel.

  17. Carbon Calculator for Land Use Change from Biofuels Production (CCLUB). Users' Manual and Technical Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States); Qin, Zhangcai [Argonne National Lab. (ANL), Argonne, IL (United States); Mueller, Steffen [Univ. of Illinois at Chicago, Chicago, IL (United States); Kwon, Ho-young [International Food Policy Research Institute (IFPRI), Washington, DC (United States); Wander, Michelle M. [Univ. of Illinois, Urbana-Champaign, IL (United States); Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-09-01

    The Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) calculates carbon emissions from land use change (LUC) for four different ethanol production pathways including corn grain ethanol and cellulosic ethanol from corn stover, Miscanthus, and switchgrass. This document discusses the version of CCLUB released September 30, 2014 which includes corn and three cellulosic feedstocks: corn stover, Miscanthus, and switchgrass.

  18. 76 FR 4291 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Partial Rescission of...

    Science.gov (United States)

    2011-01-25

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... administrative review of the countervailing duty order on corrosion- resistant carbon steel flat products from... ] requests for administrative review and partial revocation of the countervailing duty order on corrosion...

  19. 76 FR 69703 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Extension of...

    Science.gov (United States)

    2011-11-09

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...) published a notice of initiation of the administrative review of the antidumping duty order on corrosion... results of this review. See Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of...

  20. 77 FR 25141 - Corrosion-Resistant Carbon Steel Flat Products From Germany and South Korea: Extension of Time...

    Science.gov (United States)

    2012-04-27

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and South Korea... of the antidumping duty (AD) orders on corrosion-resistant carbon steel flat products (CORE) from... Countervailing Duty Operations, Office 3, regarding ``Sunset Reviews of the Antidumping Duty Orders on Corrosion...

  1. 78 FR 19210 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2013-03-29

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...) has completed its administrative review of the countervailing duty (CVD) order on corrosion-resistant...\\ See Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

  2. 75 FR 77615 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Extension of...

    Science.gov (United States)

    2010-12-13

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...) published a notice of initiation of the administrative review of the antidumping duty order on corrosion... results of this review. See Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of...

  3. Short and Long Term Impacts of Forest Bioenergy Production on Atmospheric Carbon Dioxide Emissions

    Science.gov (United States)

    Hudiburg, T.; Law, B. E.; Luyssaert, S.; Thornton, P. E.

    2011-12-01

    Temperate forest annual net uptake of CO2 from the atmosphere is equivalent to ~16% of the annual fossil fuel emissions in the United States. Mitigation strategies to reduce emissions of carbon dioxide have lead to investigation of alternative sources of energy including forest biomass. The prospect of forest derived bioenergy has led to implementation of new forest management strategies based on the assumption that they will reduce total CO2 emissions to the atmosphere by simultaneously reducing the risk of wildfire and substituting for fossil fuels. The benefit of managing forests for bioenergy substitution of fossil fuels versus potential carbon sequestration by reducing harvest needs to be evaluated. This study uses a combination of Federal Forest Inventory data (FIA), remote sensing, and a coupled carbon-nitrogen ecosystem process model (CLM4-CN) to predict net atmospheric CO2 emissions from forest thinning for bioenergy production in Oregon under varying future management and climate scenarios. We use life-cycle assessment (LCA) incorporating both the forest and forest product sinks and sources of carbon dioxide. Future modeled results are compared with a reduced harvest scenario to determine the potential for increased carbon sequestration in forest biomass. We find that Oregon forests are a current strong sink of 7.5 ± 1.7 Tg C yr-1 or 61 g C m-2 yr-1. (NBP; NEP minus removals from fire and harvest). In the short term, we find that carbon dynamics following harvests for fire prevention and large-scale bioenergy production lead to 2-15% higher emissions over the next 20 years compared to current management, assuming 100% effectiveness of fire prevention. Given the current sink strength, analysis of the forest sector in Oregon demonstrates that increasing harvest levels by all practices above current business-as-usual levels increases CO2 emissions to the atmosphere as long as the region's sink persists. In the long-term, we find that projected changes in

  4. Experimental operation of the production line for carbon fiber-reinforced plastic

    Energy Technology Data Exchange (ETDEWEB)

    Boldin, V.M.; Denezhkin, N.M.; Krivoshchekova, N.P.; Krotova, Z.S.; Yermakov, V.F.

    1979-01-01

    Verifications of the quality of the manufactured tubings established that in physical-mechanical indicators the carbon fiber-reinforced plastic corresponds to the requirements which are made for the material of the timbering rising, operated in the zone of intensive manifestation of mine pressure, and exposed to the effect of a stream of coal transmitted through it. Average data are presented for physical-mechanical properties of the carbon fiber-reinforced plastic according to samples manufactured from the tubings. In 1974-1978 the production line produced over 130,000 tubings, or 6600m of timbering to two type-sizes with inner diameter of 850 and 1090 mm. Experimental operation of the production line indicated that as a whole it is efficient, simple and convenient to operate, and guarantees safe working conditions of the service personnel. Verification and pinpointing of the production parameters for making timbering, as well as generalization of the experience of operating the line made it possible to plan a production line with maximum mechanization and automation of the operations of the production process and increase its productivity two-fold. The production line will be put into operation in 1980 in the experimental shop TsEMM No 4 of the production association ''Prokop'yevskugol'.''

  5. Nutrient and temperature controls on modern carbonate production: An example from the Gulf of California, Mexico

    Science.gov (United States)

    Halfar, Jochen; Godinez-Orta, Lucio; Mutti, Maria; Valdez-Holguín, José E.; Borges, Jose M.

    2004-03-01

    In addition to salinity and temperature, nutrient concentrations in surface waters are known to have a significant impact on distribution of carbonate-producing biota, but have never been quantitatively evaluated against different temperatures along a latitudinal transect. The western coast of the Gulf of California, Mexico, presents a natural laboratory for investigating the influence of oceanographic parameters such as salinity, temperature, and chlorophyll a, a proxy for nutrients, on the composition of a range of modern heterozoan and photozoan carbonate environments along a north-south latitudinal gradient spanning the entire warm-temperate realm (29°N 23°N). Chlorophyll a, measured in situ at half-hour resolution, is highly variable throughout the year due to short-term upwelling, and increases significantly from the southern to northern Gulf of California. Salinity, in contrast, fluctuates little and remains at an average of 35‰. From south to north, carbonate production ranges from oligotrophic-mesotrophic, coral reef dominated shallow-water areas (minimum temperature 18.6 °C) through mesotrophic-eutrophic, red algal dominated, inner-shelf carbonate production in the central gulf (minimum temperature 16 °C), and to molluscan-bryozoan, eutrophic inner- to outer-shelf environments (minimum temperature 13.7 °C). The Gulf of California data, supplemented with oceanographic and compositional information from a database compiled from a spectrum of modern carbonate systems worldwide, demonstrates the significance of nutrient control in the formation of heterozoan, photozoan, and transitional heterozoan-photozoan carbonate systems and serves as a basis for more accurately interpreting fossil carbonates.

  6. Electro-osmotic-based catholyte production by Microbial Fuel Cells for carbon capture.

    Science.gov (United States)

    Gajda, Iwona; Greenman, John; Melhuish, Chris; Santoro, Carlo; Li, Baikun; Cristiani, Pierangela; Ieropoulos, Ioannis

    2015-12-01

    In Microbial Fuel Cells (MFCs), the recovery of water can be achieved with the help of both active (electro-osmosis), and passive (osmosis) transport pathways of electrolyte through the semi-permeable selective separator. The electrical current-dependent transport, results in cations and electro-osmotically dragged water molecules reaching the cathode. The present study reports on the production of catholyte on the surface of the cathode, which was achieved as a direct result of electricity generation using MFCs fed with wastewater, and employing Pt-free carbon based cathode electrodes. The highest pH levels (>13) of produced liquid were achieved by the MFCs with the activated carbon cathodes producing the highest power (309 μW). Caustic catholyte formation is presented in the context of beneficial cathode flooding and transport mechanisms, in an attempt to understand the effects of active and passive diffusion. Active transport was dominant under closed circuit conditions and showed a linear correlation with power performance, whereas osmotic (passive) transport was governing the passive flux of liquid in open circuit conditions. Caustic catholyte was mineralised to a mixture of carbonate and bicarbonate salts (trona) thus demonstrating an active carbon capture mechanism as a result of the MFC energy-generating performance. Carbon capture would be valuable for establishing a carbon negative economy and environmental sustainability of the wastewater treatment process.

  7. Eco-Materials Made From Industrial By-Products and Carbon Dioxide

    Science.gov (United States)

    Goto, S.

    2007-03-01

    The eco-materials made from steel-making slag and carbon dioxide are introduced. Steel-making slag is one of industrial by-products and it has been wanted to be used in more beneficial way. Carbon dioxide is also wanted to be decreased the emission for green house effects. The materials made with steel-making slag by carbonation have very high strength and very high durability for hydration and abrasion. Mechanisms of carbonation reaction is discussed, in which the effects of water content, temperature, porosity of compacts, gas content and pressure, etc. are discussed. The compressive strength was obtained about 100 MPa at a porosity of 10 volume %these carbonated blocks have higher abrasion resistance than hydrated cement pastes. The most benefit in this process is no energy is required for the reaction except that of grinding, handling and/or transportation of materials. The exhaust gas from plant will be available for the source of carbon dioxide. Lastly, Marine block, matrix of glass fiber reinforced concrete, and artificial aggregate are introduced as application examples.

  8. Culture strategies for lipid production using acetic acid as sole carbon source by Rhodosporidium toruloides.

    Science.gov (United States)

    Huang, Xiang-Feng; Liu, Jia-Nan; Lu, Li-Jun; Peng, Kai-Ming; Yang, Gao-Xiang; Liu, Jia

    2016-04-01

    Rhodosporidium toruloides AS 2.1389 was tested using different concentrations of acetic acid as a low-cost carbon source for the production of microbial lipids, which are good raw materials for biodiesel production. It grew and had higher lipid contents in media containing 4-20 g/L acetic acid as the sole carbon source, compared with that in glucose-containing media under the same culture conditions. At acetic acid concentrations as high as 20 g/L and the optimal carbon-to-nitrogen ratio (C/N) of 200 in a batch culture, the highest biomass production was 4.35 g/L, with a lipid content of 48.2%. At acetic acid concentrations as low as 4 g/L, a sequencing batch culture (SBC) with a C/N of 100 increased biomass production to 4.21 g/L, with a lipid content of 38.6%. These results provide usable culture strategies for lipid production by R. toruloides AS 2.1389 when using diverse waste-derived volatile fatty acids.

  9. Analysis of Possibility of Yeast Production Increase at Maintained Carbon Dioxide Emission Level

    Science.gov (United States)

    Włodarczyk, Barbara; Włodarczyk, Paweł P.

    2016-12-01

    Main parameters polluting of technological wastewater (dregs from decantation and thicken of the wort) from yeast industry are: nitrogen, potassium and COD. Such wastewater are utilized mostly on agricultural fields. Unfortunately, these fields can only accept a limited amount of wastes. The basic parameter limiting there the amount of wastewater is nitrogen. When capacity of the production is large sewages are often pretreated at an evaporator station. However, due to the fairly high running costs of the evaporator station currently such a solution is applied only to a small amount of wastes (just to meet legal requirements). Replacement of the earth gas with a biomass being supplied to the evaporator station from the agricultural fields will both allow to maintain the carbon dioxide emission level and enable the production growth. Moreover, the biomass growing on the agricultural fields being fertilized with the wastewater coming from the yeast production allows consequently to utilize the greater volume of wastewater. Theoretically, the possible increase in the yeasts production, with maintaining the carbon dioxide emission level, can reach even 70%. Therefore, the solution presented in this paper combines both intensification of the yeasts production and maintaining the carbon dioxide emission level.

  10. Analysis of Possibility of Yeast Production Increase at Maintained Carbon Dioxide Emission Level

    Directory of Open Access Journals (Sweden)

    Włodarczyk Barbara

    2016-12-01

    Full Text Available Main parameters polluting of technological wastewater (dregs from decantation and thicken of the wort from yeast industry are: nitrogen, potassium and COD. Such wastewater are utilized mostly on agricultural fields. Unfortunately, these fields can only accept a limited amount of wastes. The basic parameter limiting there the amount of wastewater is nitrogen. When capacity of the production is large sewages are often pretreated at an evaporator station. However, due to the fairly high running costs of the evaporator station currently such a solution is applied only to a small amount of wastes (just to meet legal requirements. Replacement of the earth gas with a biomass being supplied to the evaporator station from the agricultural fields will both allow to maintain the carbon dioxide emission level and enable the production growth. Moreover, the biomass growing on the agricultural fields being fertilized with the wastewater coming from the yeast production allows consequently to utilize the greater volume of wastewater. Theoretically, the possible increase in the yeasts production, with maintaining the carbon dioxide emission level, can reach even 70%. Therefore, the solution presented in this paper combines both intensification of the yeasts production and maintaining the carbon dioxide emission level.

  11. Removal of the Fermentation Inhibitor, Furfural, Using Activated Carbon in Cellulosic-Ethanol Production

    KAUST Repository

    Zhang, Kuang

    2011-12-21

    Ethanol can be produced from lignocellulosic biomass through fermentation; however, some byproducts from lignocellulosics, such as furfural compounds, are highly inhibitory to the fermentation and can substantially reduce the efficiency of ethanol production. In this study, commercial and polymer-derived activated carbons were utilized to selectively remove the model fermentation inhibitor, furfural, from water solution during bioethanol production. The oxygen functional groups on the carbon surface were found to influence the selectivity of sorbents between inhibitors and sugars during the separation. After inhibitors were selectively removed from the broth, the cell growth and ethanol production efficiency was recovered noticeably in the fermentation. A sorption/desorption cycle was designed, and the sorbents were regenerated in a fixed-bed column system using ethanol-containing standard solution. Dynamic mass balance was obtained after running four or five cycles, and regeneration results were stable even after twenty cycles. © 2011 American Chemical Society.

  12. Techno-economics of carbon preserving butanol production using a combined fermentative and catalytic approach.

    Science.gov (United States)

    Nilsson, Robert; Bauer, Fredric; Mesfun, Sennai; Hulteberg, Christian; Lundgren, Joakim; Wännström, Sune; Rova, Ulrika; Berglund, Kris Arvid

    2014-06-01

    This paper presents a novel process for n-butanol production which combines a fermentation consuming carbon dioxide (succinic acid fermentation) with subsequent catalytic reduction steps to add hydrogen to form butanol. Process simulations in Aspen Plus have been the basis for the techno-economic analyses performed. The overall economy for the novel process cannot be justified, as production of succinic acid by fermentation is too costly. Though, succinic acid price is expected to drop drastically in a near future. By fully integrating the succinic acid fermentation with the catalytic conversion the need for costly recovery operations could be reduced. The hybrid process would need 22% less raw material than the butanol fermentation at a succinic acid fermentation yield of 0.7g/g substrate. Additionally, a carbon dioxide fixation of up to 13ktonnes could be achieved at a plant with an annual butanol production of 10ktonnes.

  13. Corrosion Products and Formation Mechanism During Initial Stage of Atmospheric Corrosion of Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    XIAO Kui; DONG Chao-fang; LI Xiao-gang; WANG Fu-ming

    2008-01-01

    The formation and development of corrosion products on carbon steel surface during the initial stage of atmospheric corrosion in a laboratory simulated environment have been studied by scanning electron microscopy (SEM)and Raman spectroscopy.The results showed that two different shapes of corrosion products,that is,ring and chain,were formed in the initial stage of corrosion.MnS clusters were found in the nuclei of corrosion products at the active local corrosion sites.The ring-shaped products were composed of lepidocrocite (γ-FeOOH) and maghemite(γ-Fe2 O3) transformed from lepidocrocite.The chain-type products were goethite (α-FeOOH).A formation mechanism of the corrosion products is proposed.

  14. Production of extracellular proteases by Mucor circinelloides using D-glucose as carbon source / substrate

    Directory of Open Access Journals (Sweden)

    Andrade Vânia Sousa

    2002-01-01

    Full Text Available Recently, some Mucorales species have been reported as protease producers. The production of extracellular proteases by Mucor circinelloides using glucose as substrate was studied. Experiments were carried out with different D-glucose concentrations (40, 60 and 80 g/L. Biomass, pH and protease activity were determined. Although biomass production had reached best yields for the medium containing D-glucose in a concentration of 80 g/L, the enzymatic production was higher when the substrate concentration was reduced to 40 g/L. The yield factor for product on cell growth and the yield factor for product on carbon substrate were higher when the microorganism grew in medium containing 40 g/L glucose. The kinetics parameters suggest that this strain seems to be promising as an alternative microorganism for protease production.

  15. Hydrogen and Carbon Black Production from the Degradation of Methane by Thermal Plasma

    Directory of Open Access Journals (Sweden)

    Leila Cottet

    2014-05-01

    Full Text Available Methane gas (CH4 is the main inducer of the so called greenhouse gases effect. Recent scientific research aims to minimize the accumulation of this gas in the atmosphere and to develop processes capable of producing stable materials with added value. Thermal plasma technology is a promising alternative to these applications, since it allows obtaining H2 and solid carbon from CH4, without the parallel formation of byproducts such as CO2 and NOx. In this work, CH4 was degraded by thermal plasma in order to produce hydrogen (H2 and carbon black. The degradation efficiency of CH4, selectivity for H2 production as well as the characterization of carbon black were studied. The best results were obtained in the CH4 flow rate of 5 L min-1 the degradation percentage and the selectivity for H2 production reached 98.8 % and 48.4 %, respectively. At flow rates of less than 5 L min-1 the selectivity for H2 production increases and reaches 91.9 %. The carbon black has obtained amorphous with hydrophobic characteristics and can be marketed to be used in composite material, and can also be activated chemically and/or physically and used as adsorbent material.

  16. Potential effects of organic carbon production on ecosystems and drinking water quality

    Directory of Open Access Journals (Sweden)

    Larry R. Brown

    2003-10-01

    Full Text Available Restoration of tidal wetlands in the Sacramento-San Joaquin Delta (Delta is an important component of the Ecosystem Restoration Program of the CALFED Bay-Delta Program (CALFED. CALFED is a collaborative effort among state and federal agencies to restore the ecological health and improve water management of the Delta and San Francisco Bay (Bay. Tidal wetland restoration is intended to provide valuable habitat for organisms and to improve ecosystem productivity through export of various forms of organic carbon, including both algae and plant detritus. However, the Delta also provides all or part of the drinking water for over 22 million Californians. In this context, increasing sources of organic carbon may be a problem because of the potential increase in the production of trihalomethanes and other disinfection by-products created during the process of water disinfection. This paper reviews the existing information about the roles of organic carbon in ecosystem function and drinking water quality in the Bay-Delta system, evaluates the potential for interaction, and considers major uncertainties and potential actions to reduce uncertainty. In the last 10 years, substantial progress has been made on the role of various forms of organic carbon in both ecosystem function and drinking water quality; however, interactions between the two have not been directly addressed. Several ongoing studies are beginning to address these interactions, and the results from these studies should reduce uncertainty and provide focus for further research.

  17. Allochthonous Carbon--a Major Driver of Bacterioplankton Production in the Subarctic Northern Baltic Sea.

    Science.gov (United States)

    Figueroa, D; Rowe, O F; Paczkowska, J; Legrand, C; Andersson, A

    2016-05-01

    Heterotrophic bacteria are, in many aquatic systems, reliant on autochthonous organic carbon as their energy source. One exception is low-productive humic lakes, where allochthonous dissolved organic matter (ADOM) is the major driver. We hypothesized that bacterial production (BP) is similarly regulated in subarctic estuaries that receive large amounts of riverine material. BP and potential explanatory factors were measured during May-August 2011 in the subarctic Råne Estuary, northern Sweden. The highest BP was observed in spring, concomitant with the spring river-flush and the lowest rates occurred during summer when primary production (PP) peaked. PLS correlations showed that ∼60% of the BP variation was explained by different ADOM components, measured as humic substances, dissolved organic carbon (DOC) and coloured dissolved organic matter (CDOM). On average, BP was threefold higher than PP. The bioavailability of allochthonous dissolved organic carbon (ADOC) exhibited large spatial and temporal variation; however, the average value was low, ∼2%. Bioassay analysis showed that BP in the near-shore area was potentially carbon limited early in the season, while BP at seaward stations was more commonly limited by nitrogen-phosphorus. Nevertheless, the bioassay indicated that ADOC could contribute significantly to the in situ BP, ∼60%. We conclude that ADOM is a regulator of BP in the studied estuary. Thus, projected climate-induced increases in river discharge suggest that BP will increase in subarctic coastal areas during the coming century.

  18. Treatment of aqueous phase of bio-oil by granular activated carbon and evaluation of biogas production.

    Science.gov (United States)

    Shanmugam, Saravanan R; Adhikari, Sushil; Wang, Zhouhang; Shakya, Rajdeep

    2017-01-01

    Hydrothermal liquefaction of wet biomass such as algae is a promising thermochemical process for the production of bio-oil. Bio-oil aqueous phase generated during liquefaction process is rich in complex organics and can be utilized for biogas production following its pre-treatment with granular activated carbon. In our study, use of 30% activated carbon resulted in higher chemical oxygen demand (COD) reduction (53±0.3%) from aqueous phase. Higher CH4 production (84±12mL/gCOD) was also observed in 30% carbon-treated aqueous phase fed cultures, whereas only 32±6mLCH4/gCOD was observed in control (non-carbon treated) cultures. The results from this study indicate that almost 67±0.3% initial COD of aqueous phase can be reduced using a combination of both carbon treatment and biogas production. This study shows that aqueous phase can be utilized for CH4 production.

  19. Stellar production rates of carbon and its abundance in the universe

    CERN Document Server

    Oberhummer, Heinz; Schlattl, H; Oberhummer, Heinz; Csoto, Attila; Schlattl, Helmut

    2000-01-01

    The bulk of the carbon in our universe is produced in the triple-alpha process in helium-burning red giant stars. We calculated the change of the triple-alpha reaction rate in a microscopic 12-nucleon model of the C-12 nucleus and looked for the effects of minimal variations of the strengths of the underlying interactions. Stellar model calculations were performed with the alternative reaction rates. Here, we show that outside a narrow window of 0.5 and 4% of the values of the strong and Coulomb forces, respectively, the stellar production of carbon or oxygen is reduced by factors of 30 to 1000.

  20. Production of carbon nanofibers in high yields using a sodium chloride support.

    Science.gov (United States)

    Geng, Junfeng; Kinloch, Ian A; Singh, Charanjeet; Golovko, Vladimir B; Johnson, Brian F G; Shaffer, Milo S P; Li, Yali; Windle, Alan H

    2005-09-08

    A new route for the highly convenient scalable production of carbon nanofibers on a sodium chloride support has been developed. Since the support is nontoxic and soluble in water, it can be easily removed without damage to the nanofibers and the environment. Nanofiber yields of up to 6500 wt % relative to the nickel catalyst have been achieved in a growth time of 15 min. Electron microscopy (SEM, TEM) and thermal gravimetric analysis (TGA) indicated that the catalytically grown carbon had relatively little thermal over-growth and possessed either a herringbone or a semi-ordered nanostructure, depending on the growth conditions.

  1. A microalgae residue based carbon solid acid catalyst for biodiesel production.

    Science.gov (United States)

    Fu, Xiaobo; Li, Dianhong; Chen, Jie; Zhang, Yuanming; Huang, Weiya; Zhu, Yi; Yang, Jun; Zhang, Chengwu

    2013-10-01

    Biodiesel production from microalgae is recognized as one of the best solutions to deal with the energy crisis issues. However, after the oil extraction from the microalgae, the microalgae residue was generally discarded or burned. Here a novel carbon-based solid acid catalyst derived from microalgae residue by in situ hydrothermal partially carbonization were synthesized. The obtained catalyst was characterized and subjected to both the esterification of oleic acid and transesterification of triglyceride to produce biodiesel. The catalyst showed high catalytic activity and can be regenerated while its activity can be well maintained after five cycles.

  2. Study on the production of alternative fuels by carbon dioxide hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Kyu Sung; Han, Sang Do; Kim, Jong Won; Kim, Youn Soon; Seo, Ji Mi [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

    1995-12-01

    The technologies of the fuel production from carbon dioxide by catalytic hydrogenation were surveyed. For the catalytic hydrogenation we made the lab-scale reaction apparatus and carried out some experiments with various catalysts like CuO/ZnO/Al{sub 2}O{sub 3}, Raney nickel and other commercial catalysts. In this year, the third year of the project, the experiments to find optimum catalysts and obtain the good conditions of carbon dioxide were performed followed by second year. And also the processes of the methanol synthesis was investigated simultaneously. (author). 58 refs., 58 figs., 28 tabs.

  3. Simple method for mass production of polypyrrole/carbon nanotubes hybrid artificial muscle

    Directory of Open Access Journals (Sweden)

    Marcelo R. dos Santos

    2014-07-01

    Full Text Available Large scale preparation of hybrid electrical actuators represents an important step for the production of low cost devices. Interfacial polymerization of polypyrrole in the presence of multi-walled carbon nanotubes represents a simple technique in which strong interaction between components is established, providing composite materials with potential applications as actuators due to the synergistic interaction between the individual components, i.e., fast response of carbon nanotubes, high strain of polypyrrole, and diversity in the available geometry of resulting samples.

  4. Modeled Climate and Disturbance Impacts to Carbon Sequestration of Recent Interior Boreal Alaska Ecosystem Productivity Declines

    Science.gov (United States)

    Neigh, C. S.; Carvalhais, N.; Collatz, G. J.; Tucker, C. J.

    2010-12-01

    Terrestrial Higher Northern Latitude Boreal ecosystems over the past half century have and are expected to incur substantial future climate warming altering long-term biophysical processes that mediate carbon sink status. Boreal ecosystems are one of the primary terrestrial pools with high organic and mineral soil carbon concentrations due to reduced decomposition from extended periods below freezing. Direct impacts of changing local to regional climate have altered Interior Alaska disturbance regimes shifting patterns of net primary production (NPP), soil heterotrophic respiration (Rh), net ecosystem production (NEP = NPP - Rh) and net biome production (NBP = NEP - De) which includes disturbance events (De). We investigated ecosystem dynamics with a satellite remote sensing driven model accounting for fine-scale heterogeneous events observed from multi temporal-spectral index vectors derived from Landsat. Our intent was to elucidate local to regional processes which have resulted in negative trends observed from the NOAA series of Advanced Very High Resolution Radiometers (AVHRR) over the past decade. The Carnegie-Ames-Stanford approach (CASA) model was run with changing fractional burned area to simulate bi-monthly patterns of net plant carbon fixation, biomass and nutrient allocation, litterfall, soil nitrogen mineralization, combustion emissions, and microbial CO2 production. Carbon reallocation was based on fire disturbances identified with remote sensing data (Landsat, IKONOS, and aerial photography) and disturbance perimeter maps from land management agencies. Warming coupled with insect and fire disturbance emissions reduced interior Boreal forest recalcitrant carbon pools for which losses greatly exceed the North Slope Tundra sink. Our multi spatial-temporal approach confirms substantial forested NPP declines in Landsat and AVHRR while distinguishing abiotic and biophysical disturbance frequency impacts upon NBP.

  5. Potential for improving the carbon footprint of butter and blend products

    DEFF Research Database (Denmark)

    Flysjö, Anna Maria

    2011-01-01

    on the price paid for raw milk to dairy farmers. The CF (expressed as carbon dioxide equivalents, CO2e) for 1 kg of butter or blend (assuming no product waste at consumer) ranged from 5.2 kg (blend with 60% fat content) to 9.3 kg of CO2e (butter in 250-g tub). When including product waste at the consumer level......To reduce the environmental impact of a product efficiently, it is crucial to consider the entire value chain of the product; that is, to apply life cycle thinking, to avoid suboptimization and identify the areas where the largest potential improvements can be made. This study analyzed the carbon...... footprint (CF) of butter and dairy blend products, with the focus on fat content and size and type of packaging (including product waste at the consumer level). The products analyzed were butter with 80% fat in 250-g wrap, 250-g tub, and 10-g mini tub, and blends with 80% and 60% fat in 250-g tubs. Life...

  6. Sustainability of meat production beyond carbon footprint: a synthesis of case studies from grazing systems in Uruguay.

    Science.gov (United States)

    Picasso, Valentín D; Modernel, Pablo D; Becoña, Gonzalo; Salvo, Lucía; Gutiérrez, Lucía; Astigarraga, Laura

    2014-11-01

    Livestock production has been challenged as a large contributor to climate change, and carbon footprint has become a widely used measure of cattle environmental impact. This analysis of fifteen beef grazing systems in Uruguay quantifies the range of variation of carbon footprint, and the trade-offs with other relevant environmental variables, using a partial life cycle assessment (LCA) methodology. Using carbon footprint as the primary environmental indicator has several limitations: different metrics (GWP vs. GTP) may lead to different conclusions, carbon sequestration from soils may drastically affect the results, and systems with lower carbon footprint may have higher energy use, soil erosion, nutrient imbalance, pesticide ecotoxicity, and impact on biodiversity. A multidimensional assessment of sustainability of meat production is therefore needed to inform decision makers. There is great potential to improve grazing livestock systems productivity while reducing carbon footprint and other environmental impacts, and conserving biodiversity.

  7. Hamiltonian replica-permutation method and its applications to an alanine dipeptide and amyloid-β(29-42) peptides.

    Science.gov (United States)

    Itoh, Satoru G; Okumura, Hisashi

    2013-11-05

    We propose the Hamiltonian replica-permutation method (RPM) (or multidimensional RPM) for molecular dynamics and Monte Carlo simulations, in which parameters in the Hamiltonian are permuted among more than two replicas with the Suwa-Todo algorithm. We apply the Coulomb RPM, which is one of realization of the Hamiltonian RPM, to an alanine dipeptide and to two amyloid-β(29-42) molecules. The Hamiltonian RPM realizes more efficient sampling than the Hamiltonian replica-exchange method. We illustrate the protein misfolding funnel of amyloid-β(29-42) and reveal its dimerization pathways.

  8. Monitoring changes in soil carbon resulting from intensive production, a non-traditional agricultural methodology.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Brian P.

    2013-03-01

    New Mexico State University and a group of New Mexico farmers are evaluating an innovative agricultural technique they call Intensive Production (IP). In contrast to conventional agricultural practice, IP uses intercropping, green fallowing, application of soil amendments and soil microbial inocula to sequester carbon as plant biomass, resulting in improved soil quality. Sandia National Laboratories role was to identify a non-invasive, cost effective technology to monitor soil carbon changes. A technological review indicated that Laser Induced Breakdown Spectroscopy (LIBS) best met the farmers objectives. Sandia partnered with Los Alamos National Laboratory (LANL) to analyze farmers test plots using a portable LIBS developed at LANL. Real-time LIBS field sample analysis was conducted and grab samples were collected for laboratory comparison. The field and laboratory results correlated well implying the strong potential for LIBS as an economical field scale analytical tool for analysis of elements such as carbon, nitrogen, and phosphate.

  9. A review of production methods of carbon nanotube and graphene thin films for electrothermal applications

    Science.gov (United States)

    Janas, D.; Koziol, K. K.

    2014-02-01

    Electrothermal materials transform electric energy into heat due to the Joule effect. To date, resistive wires made of heavy metal alloys have primarily been used as the heat source in many appliances surrounding us. Recent discoveries in the field of carbon nanostructures revealed that they can offer a spectrum of advantages over the traditional materials. We review the production methods of thin films composed of carbon nanotubes or graphene and depict how they can be used as conductive coatings for electrothermal applications. We screen all reports from the field up to now and highlight the features of designed nanoheaters. A particular focus is placed on the analysis of general findings of how to tune their electrothermal properties, why carbon nanostructure devices operate the way they do and in what aspects they are superior to the currently available materials on the market.

  10. Effect of carbon and nitrogen sources on carotenoids production by native strain of Aurantiochytrium Ch25

    Directory of Open Access Journals (Sweden)

    Mahdiye Esmizade

    2016-09-01

    Full Text Available Introduction: Microorganisms produce carotenoids as a part of their response to environmental stresses. Carotenoids have many applications in human health, such as antioxidant, anti-cancer, light protection activity and as a precursor for hormones. Materials and methods: In this study, the effect of different carbon and nitrogen sources was evaluated on carotenoids production by native Aurantiochytrium strain. The effects of different carbon and nitrogen sources were studied on biomass and carotenoid production. Then, carotenoids were extracted and analyzed by TLC, spectrophotometry and HPLC methods. Results: Results showed that glycerol is the best carbon source for production of high carotenoids content. Selected medium contained: glycerol (1.5% v/v, peptone (1g/l, yeast extract (1g/l and 50% of sea water. Total carotenoids content was 134.8 µg/g CDW in this medium. TLC analysis showed that the extracted carotenoid is included: beta-carotene, astaxanthin monoester, astaxanthin diester and free astaxanthin. The results of HPLC analysis showed presence of astaxanthin, canthaxanthin, echinenone and β-carotene in the carotenoid extract. Discussion and conclusion: In this research, production of carotenoids was investigated in native strain of Aurantiochytrium and carotenoids profile was included astaxanthin, canthaxanthin, β-carotene and echinenone.

  11. Productivity, carbon utilization, and energy content of mass in scalable microalgae systems.

    Science.gov (United States)

    Murray, Kyle E; Shields, Jeremy A; Garcia, Nicholas D; Healy, Frank G

    2012-06-01

    This study was designed to examine carbon utilization within scalable microalgae production systems. Neochloris oleoabundans was produced in replicated troughs containing BG11 nutrient formulation. Atmospheric CO(2) was supplemented with ∼5% CO(2) or with NaHCO(3), and the pH of troughs receiving NaHCO(3) was adjusted with HCl or H(3)PO(4). Peak biomass concentrations reached 950, 1140, or 850 mg L(-1) and biomass productivities of 109, 96, and 74 mg L(-1) day(-1) were achieved in the CO(2), NaHCO(3):HCl and NaHCO(3):H(3)PO(4) troughs, respectively. The highest productivity is expected in a scaled-up continuous batch process of the CO(2) supplemented system, which was projected to yield 8948 L lipids ha(-1)yr(-1). Carbon utilization in the CO(2), NaHCO(3):HCl and NaHCO(3):H(3)PO(4) systems was ∼0.5, 15.5, and 12.9%, while the energy content of the combustible biomass was 26.7, 13.2, and 15.4 MJ kg(-1), respectively. Techno-economic analyses of microalgal production systems should consider efficiencies and cost-benefit of various carbon sources.

  12. Ground cover rice production system facilitates soil carbon and nitrogen stocks at regional scale

    Directory of Open Access Journals (Sweden)

    M. Liu

    2015-02-01

    Full Text Available Rice production is increasingly challenged by irrigation water scarcity, however covering paddy rice soils with films (ground cover rice production system: GCRPS can significantly reduce water demand as well as overcome temperature limitations at the beginning of the vegetation period resulting in increased grain yields in colder regions of rice production with seasonal water shortages. It has been speculated that the increased soil aeration and temperature under GCRPS may result in losses of soil organic carbon and nitrogen stocks. Here we report on a regional scale experiment, conducted by sampling paired adjacent Paddy and GCRPS fields at 49 representative sites in the Shiyan region, which is typical for many mountainous areas across China. Parameters evaluated included soil C and N stocks, soil physical and chemical properties, potential carbon mineralization rates, fractions of soil organic carbon and stable carbon isotopic composition of plant leaves. Furthermore, root biomass was quantified at maximum tillering stage at one of our paired sites. Against expectations the study showed that: (1 GCRPS significantly increased soil organic C and N stocks 5–20 years following conversion of production systems, (2 there were no differences between GCRPS and Paddy in soil physical and chemical properties for the various soil depths with the exception of soil bulk density, (3 GCRPS had lower mineralization potential for soil organic C compared with Paddy over the incubation period, (4 GCRPS showed lower δ15N in the soils and plant leafs indicating less NH3 volatilization in GCRPS than in Paddy; and (5 GCRPS increased yields and root biomass in all soil layers down to 40 cm depth. Our results suggest that GCRPS is an innovative rice production technique that not only increases yields using less irrigation water, but that it also is environmentally beneficial due to increased soil C and N stocks at regional scale.

  13. Techniques of replica symmetry breaking and the storage problem of the McCulloch-Pitts neuron

    Science.gov (United States)

    Györgyi, G.

    2001-02-01

    In this article we review the framework for spontaneous replica symmetry breaking. Subsequently that is applied to the example of the statistical mechanical description of the storage properties of a McCulloch-Pitts neuron, i.e., simple perceptron. It is shown that in the neuron problem, the general formula that is at the core of all problems admitting Parisi's replica symmetry breaking ansatz with a one-component order parameter appears. The details of Parisi's method are reviewed extensively, with regard to the wide range of systems where the method may be applied. Parisi's partial differential equation and related differential equations are discussed, and the Green function technique is introduced for the calculation of replica averages, the key to determining the averages of physical quantities. The Green function of the Fokker-Planck equation due to Sompolinsky turns out to play the role of the statistical mechanical Green function in the graph rules for replica correlators. The subsequently obtained graph rules involve only tree graphs, as appropriate for a mean-field-like model. The lowest order Ward-Takahashi identity is recovered analytically and shown to lead to the Goldstone modes in continuous replica symmetry breaking phases. The need for a replica symmetry breaking theory in the storage problem of the neuron has arisen due to the thermodynamical instability of formerly given solutions. Variational forms for the neuron's free energy are derived in terms of the order parameter function x( q), for different prior distribution of synapses. Analytically in the high temperature limit and numerically in generic cases various phases are identified, among them is one similar to the Parisi phase in long-range interaction spin glasses. Extensive quantities like the error per pattern change slightly with respect to the known unstable solutions, but there is a significant difference in the distribution of non-extensive quantities like the synaptic overlaps and the

  14. Investigation on the micromilled surface characterization through replica technology

    DEFF Research Database (Denmark)

    Baruffi, Federico; Parenti, P.; Cacciatore, F.

    2016-01-01

    . This represents an open issue that, in some cases, can be tackled by adopting the replication technology. The method consists in obtaining the replicated surface and performing its measurement using suitable measuring systems. This paper evaluates the actual performance of a commercial replication product...

  15. METABOLIC ENGINEERING OF CORYNEBACTERIUM GLUTAMICUM AIMED AT ALTERNATIVE CARBON SOURCES AND NEW PRODUCTS

    Directory of Open Access Journals (Sweden)

    Ahmed Zahoor

    2012-10-01

    Full Text Available Corynebacterium glutamicum is well known as the amino acid-producing workhorse of fermentation industry, being used for multi-million-ton scale production of glutamate and lysine for more than 60 years. However, it is only recently that extensive research has focused on engineering it beyond the scope of amino acids. Meanwhile, a variety of corynebacterial strains allows access to alternative carbon sources and/or allows production of a wide range of industrially relevant compounds. Some of these efforts set new standards in terms of titers and productivities achieved whereas others represent a proof-of-principle. These achievements manifest the position of C. glutamicum as an important industrial microorganism with capabilities far beyond the traditional amino acid production. In this review we focus on the state of the art of metabolic engineering of C. glutamicum for utilization of alternative carbon sources, (e.g. coming from wastes and unprocessed sources, and construction of C. glutamicum strains for production of new products such as diamines, organic acids and alcohols.

  16. Evaluation of Physarum polycephalum plasmodial growth and lipid production using rice bran as a carbon source.

    Science.gov (United States)

    Tran, Hanh; Stephenson, Steven; Pollock, Erik

    2015-08-01

    The myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production. The present study evaluated the use of rice bran as a carbon source and determined the medium components for optimum growth and lipid production for this organism. Optimization of medium components by response surface methodology showed that rice bran and yeast extract had significant influences on lipid and biomass production. The optimum medium consisted of 37.5 g/L rice bran, 0.79 g/L yeast extract and 12.5 g/L agar, and this yielded 7.5 g/L dry biomass and 0.9 g/L lipid after 5 days. The biomass and lipid production profiles revealed that these parameters increased over time and reached their maximum values (10.5 and 1.26 g/L, respectively) after 7 days. Physarum polycephalum growth decreased on the spent medium but using the latter increased total biomass and lipid concentrations to 14.3 and 1.72 g/L, respectively. An effective method for inoculum preparation was developed for biomass and lipid production by P. polycephalum on a low-cost medium using rice bran as the main carbon source. These results also demonstrated the feasibility of scaling up and reusing the medium for additional biomass and lipid production.

  17. Occupational Exposure to Multi-Walled Carbon Nanotubes During Commercial Production Synthesis and Handling.

    Science.gov (United States)

    Kuijpers, Eelco; Bekker, Cindy; Fransman, Wouter; Brouwer, Derk; Tromp, Peter; Vlaanderen, Jelle; Godderis, Lode; Hoet, Peter; Lan, Qing; Silverman, Debra; Vermeulen, Roel; Pronk, Anjoeka

    2016-04-01

    The world-wide production of carbon nanotubes (CNTs) has increased substantially in the last decade, leading to occupational exposures. There is a paucity of exposure data of workers involved in the commercial production of CNTs. The goals of this study were to assess personal exposure to multi-walled carbon nanotubes (MWCNTs) during the synthesis and handling of MWCNTs in a commercial production facility and to link these exposure levels to specific activities. Personal full-shift filter-based samples were collected, during commercial production and handling of MWCNTs, R&D activities, and office work. The concentrations of MWCNT were evaluated on the basis of EC concentrations. Associations were studied between observed MWCNT exposure levels and location and activities. SEM analyses showed MWCNTs, present as agglomerates ranging between 200 nm and 100 µm. Exposure levels of MWCNTs observed in the production area during the full scale synthesis of MWCNTs (N = 23) were comparable to levels observed during further handling of MWCNTs (N = 19): (GM (95% lower confidence limit-95% upper confidence limit)) 41 μg m(-3) (20-88) versus 43 μg m(-3) (22-86), respectively. In the R&D area (N = 11) and the office (N = 5), exposure levels of MWCNTs were significantly (P production area, whereas increased exposure levels in the R&D area were related to handling of MWCNTs powder.

  18. A replica technique for extracting precipitates from neutron-irradiated or thermal-aged vanadium alloys for TEM analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, K., E-mail: fukumoto@u-fukui.ac.jp; Iwasaki, M.

    2014-06-01

    A carbon replica technique has been developed to extract precipitates from vanadium alloys. Using this technique, precipitation phases can be extracted from neutron-irradiated or thermal-aged V–4Cr–4Ti alloys. Precipitate identification using EDS X-ray analysis and electron diffraction was facilitated. Only NaCl type of Ti(OCN) precipitate was formed in the thermal-aged V–4Cr–4Ti alloys at 600 °C for 20 h and cation sub-lattice was only occupied by Ti atoms. However, the thin plate of precipitates with NaCl type of crystallographic structure could be seen in the V–4Cr–4Ti alloys irradiated at 593 °C in the JOYO fast reactor. The precipitate contained chromium and vanadium atoms on the cation sub-lattice as well as titanium atoms. It is considered that the phase of MX type (M = Ti, V, Cr and X = O, N, C) is a metastable phase under neutron irradiation.

  19. A replica technique for extracting precipitates from neutron-irradiated or thermal-aged vanadium alloys for TEM analysis

    Science.gov (United States)

    Fukumoto, K.; Iwasaki, M.

    2014-06-01

    A carbon replica technique has been developed to extract precipitates from vanadium alloys. Using this technique, precipitation phases can be extracted from neutron-irradiated or thermal-aged V-4Cr-4Ti alloys. Precipitate identification using EDS X-ray analysis and electron diffraction was facilitated. Only NaCl type of Ti(OCN) precipitate was formed in the thermal-aged V-4Cr-4Ti alloys at 600 °C for 20 h and cation sub-lattice was only occupied by Ti atoms. However, the thin plate of precipitates with NaCl type of crystallographic structure could be seen in the V-4Cr-4Ti alloys irradiated at 593 °C in the JOYO fast reactor. The precipitate contained chromium and vanadium atoms on the cation sub-lattice as well as titanium atoms. It is considered that the phase of MX type (M = Ti, V, Cr and X = O, N, C) is a metastable phase under neutron irradiation.

  20. A New Global LAI Product and Its Use for Terrestrial Carbon Cycle Estimation

    Science.gov (United States)

    Chen, J. M.; Liu, R.; Ju, W.; Liu, Y.

    2014-12-01

    For improving the estimation of the spatio-temporal dynamics of the terrestrial carbon cycle, a new time series of the leaf area index (LAI) is generated for the global land surface at 8 km resolution from 1981 to 2012 by combining AVHRR and MODIS satellite data. This product differs from existing LAI products in the following two aspects: (1) the non-random spatial distribution of leaves with the canopy is considered, and (2) the seasonal variation of the vegetation background is included. The non-randomness of the leaf spatial distribution in the canopy is considered using the second vegetation structural parameter named clumping index (CI), which quantifies the deviation of the leaf spatial distribution from the random case. Using the MODIS Bidirectional Reflectance Distribution Function product, a global map of CI is produced at 500 m resolution. In our LAI algorithm, CI is used to convert the effective LAI obtained from mono-angle remote sensing into the true LAI, otherwise LAI would be considerably underestimated. The vegetation background is soil in crop, grass and shrub but includes soil, grass, moss, and litter in forests. Through processing a large volume of MISR data from 2000 to 2010, monthly red and near-infrared reflectances of the vegetation background is mapped globally at 1 km resolution. This new LAI product has been validated extensively using ground-based LAI measurements distributed globally. In carbon cycle modeling, the use of CI in addition to LAI allows for accurate separation of sunlit and shaded leaves as an important step in terrestrial photosynthesis and respiration modeling. Carbon flux measurements over 100 sites over the globe are used to validate an ecosystem model named Boreal Ecosystem Productivity Simulator (BEPS). The validated model is run globally at 8 km resolution for the period from 1981 to 2012 using the LAI product and other spatial datasets. The modeled results suggest that changes in vegetation structure as quantified