WorldWideScience

Sample records for carbon diooxide mixing

  1. Benefits of tree mixes in carbon plantings

    Science.gov (United States)

    Hulvey, Kristin B.; Hobbs, Richard J.; Standish, Rachel J.; Lindenmayer, David B.; Lach, Lori; Perring, Michael P.

    2013-10-01

    Increasingly governments and the private sector are using planted forests to offset carbon emissions. Few studies, however, examine how tree diversity -- defined here as species richness and/or stand composition -- affects carbon storage in these plantings. Using aboveground tree biomass as a proxy for carbon storage, we used meta-analysis to compare carbon storage in tree mixtures with monoculture plantings. Tree mixes stored at least as much carbon as monocultures consisting of the mixture's most productive species and at times outperformed monoculture plantings. In mixed-species stands, individual species, and in particular nitrogen-fixing trees, increased stand biomass. Further motivations for incorporating tree richness into planted forests include the contribution of diversity to total forest carbon-pool development, carbon-pool stability and the provision of extra ecosystem services. Our findings suggest a two-pronged strategy for designing carbon plantings including: (1) increased tree species richness; and (2) the addition of species that contribute to carbon storage and other target functions.

  2. Mixed Solvent Reactive Recrystallization of Sodium Carbonate

    NARCIS (Netherlands)

    Gaertner, R.S.

    2005-01-01

    Investigation of the reactive recrystallization of trona (sodium sesquicarbonate) and sodium bicarbonate to sodium carbonate (soda) in a mixed solvent led to the design of several alternative, less energy consumptive, economically very attractive process routes for the production of soda from all

  3. Carbon Trading in the Policy mix

    International Nuclear Information System (INIS)

    Sijm, J.P.M.; Sorrell, S.

    2003-12-01

    The Kyoto Protocol is stimulating the development of emissions-trading schemes at the national and international levels. These are being introduced alongside existing policy instruments such as carbon taxes and negotiated agreements, leading to complex problems of policy interaction. But the topic of policy interaction remains under-researched. This paper aims to improve understanding of such interactions by examining the conditions under which a cap-and-trade scheme for carbon-dioxide emissions may usefully coexist with carbon/energy taxes, support mechanisms for renewable electricity, and policies to promote energy efficiency. The paper argues that each of these instrument combinations may be acceptable, provided they contribute to either improving the static or dynamic efficiency of the trading scheme, or delivering other valued policy objectives. But, since the coexisting instruments may raise overall abatement costs while contributing nothing further to emission reductions, the objectives and trade-offs within the policy mix must be explicit

  4. Plutonium oxides and uranium and plutonium mixed oxides. Carbon determination

    International Nuclear Information System (INIS)

    Anon.

    Determination of carbon in plutonium oxides and uranium plutonium mixed oxides, suitable for a carbon content between 20 to 3000 ppm. The sample is roasted in oxygen at 1200 0 C, the carbon dioxide produced by combustion is neutralized by barium hydroxide generated automatically by coulometry [fr

  5. Mixed-layer carbon cycling at the Kuroshio Extension Observatory

    Science.gov (United States)

    Fassbender, Andrea J.; Sabine, Christopher L.; Cronin, Meghan F.; Sutton, Adrienne J.

    2017-02-01

    Seven years of data from the NOAA Kuroshio Extension Observatory (KEO) surface mooring, located in the North Pacific Ocean carbon sink region, were used to evaluate drivers of mixed-layer carbon cycling. A time-dependent mass balance approach relying on two carbon tracers was used to diagnostically evaluate how surface ocean processes influence mixed-layer carbon concentrations over the annual cycle. Results indicate that the annual physical carbon input is predominantly balanced by biological carbon uptake during the intense spring bloom. Net annual gas exchange that adds carbon to the mixed layer and the opposing influence of net precipitation that dilutes carbon concentrations make up smaller contributions to the annual mixed-layer carbon budget. Decomposing the biological term into annual net community production (aNCP) and calcium carbonate production (aCaCO3) yields 7 ± 3 mol C m-2 yr-1 aNCP and 0.5 ± 0.3 mol C m-2 yr-1 aCaCO3, giving an annually integrated particulate inorganic carbon to particulate organic carbon production ratio of 0.07 ± 0.05, as a lower limit. Although we find that vertical physical processes dominate carbon input to the mixed layer at KEO, it remains unclear how horizontal features, such as eddies, influence carbon production and export by altering nutrient supply as well as the depth of winter ventilation. Further research evaluating linkages between Kuroshio Extension jet instabilities, eddy activity, and nutrient supply mechanisms is needed to adequately characterize the drivers and sensitivities of carbon cycling near KEO.

  6. Carbon-enhanced metal-poor stars and thermohaline mixing

    NARCIS (Netherlands)

    Stancliffe, R.J.; Glebbeek, E.; Izzard, R.G.; Pols, O.R.

    2007-01-01

    One possible scenario for the formation of carbon-enhanced metal-poor stars is the accretion of carbon-rich material from a binary companion which may no longer visible. It is generally assumed that the accreted material remains on the surface of the star and does not mix with the interior until

  7. Mixed structures in continuously cooled low-carbon automotive steels

    International Nuclear Information System (INIS)

    Khalid, F.A.; Edmonds, D.V.

    1993-01-01

    Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.)

  8. Molten carbonate fuel cell cathode with mixed oxide coating

    Science.gov (United States)

    Hilmi, Abdelkader; Yuh, Chao-Yi

    2013-05-07

    A molten carbonate fuel cell cathode having a cathode body and a coating of a mixed oxygen ion conductor materials. The mixed oxygen ion conductor materials are formed from ceria or doped ceria, such as gadolinium doped ceria or yttrium doped ceria. The coating is deposited on the cathode body using a sol-gel process, which utilizes as precursors organometallic compounds, organic and inorganic salts, hydroxides or alkoxides and which uses as the solvent water, organic solvent or a mixture of same.

  9. Investigation of bioresistant dry building mixes modified by carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Korolev Evgeniy Valer'evich

    2015-04-01

    Full Text Available Dry construction mixes are today a product of high technologies. Depending on the purpose and requirements to the properties it is easy to produce dry construction mixes with different compositions and operating indicators in plant conditions using the necessary modifying additives. Cement, gypsum and other mineral binders are used in the construction mixes. Different types of cement are more heavily used in dry construction mixes. Such dry mixes are believed to be more effective materials comparing to traditional cement-sandy solutions of centralized preparation. The authors present the results of the investigations on obtaining biocidal cement-sand compositions. It was established, that introduction of sodium sulfate into the composition provides obtaining the materials with funginert and fungicide properties. The strength properties of the mixes modified by carbon nanotubes and biocide additive were investigated by mathematical planning methods. The results of the investigations showed that the modification of cement stone structure by carbon nanotubes positively influences their strength and technological properties. Nanomodifying of construction composites by introducing carbon nanotubes may be effectively used at different stages of structure formation of a construction material.

  10. Mixed Carbon Policies Based on Cooperation of Carbon Emission Reduction in Supply Chain

    Directory of Open Access Journals (Sweden)

    Yongwei Cheng

    2017-01-01

    Full Text Available This paper established cooperation decision model for a mixed carbon policy of carbon trading-carbon tax (environmental tax in a two-stage S-M supply chain. For three different cooperative abatement situations, we considered the supplier driven model, the manufacturer driven model, and the equilibrium game model. We investigated the influence of mixed carbon policy with constraint of reduction targets on supply chain price, productivity, profits, carbon emissions reduction rate, and so on. The results showed that (1 high-strength carbon policies do not necessarily encourage enterprises to effectively reduce emissions, and increasing market acceptance of low carbon products or raising the price of carbon quota can promote the benign reduction; (2 perfect competitive carbon market has a higher carbon reduction efficiency than oligarch carbon market, but their optimal level of cooperation is the same and the realized reduction rate is in line with the intensity of carbon policy; (3 the policy sensitivity of the carbon trading mechanism is stronger than the carbon tax; “paid quota mechanism” can subsidize the cost of abatement and improve reduction initiative. Finally, we use a numerical example to solve the optimal decisions under different market situations, validating the effectiveness of model and the conclusions.

  11. Carbon bed mercury emissions control for mixed waste treatment.

    Science.gov (United States)

    Soelberg, Nick; Enneking, Joe

    2010-11-01

    Mercury has various uses in nuclear fuel reprocessing and other nuclear processes, and so it is often present in radioactive and mixed (radioactive and hazardous) wastes. Compliance with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards can require off-gas mercury removal efficiencies up to 99.999% for thermally treating some mixed waste streams. Test programs have demonstrated this level of off-gas mercury control using fixed beds of granular sulfur-impregnated activated carbon. Other results of these tests include (1) the depth of the mercury control mass transfer zone was less than 15-30 cm for the operating conditions of these tests; (2) MERSORB carbon can sorb mercury up to 19 wt % of the carbon mass; and (3) the spent carbon retained almost all (98.3-99.99%) of the mercury during Toxicity Characteristic Leachability Procedure (TCLP) tests, but when even a small fraction of the total mercury dissolves, the spent carbon can fail the TCLP test when the spent carbon contains high mercury concentrations.

  12. Carbon Bed Mercury Emissions Control For Mixed Waste Treatment

    International Nuclear Information System (INIS)

    Soelberg, Nick; Enneking, Joe

    2010-01-01

    Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (both radioactive and hazardous according to the Resource Conservation and Recovery Act) wastes. Depending on regulatory requirements, the mercury in the off-gas must be controlled with sometimes very high efficiencies. Compliance to the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards can require off-gas mercury removal efficiencies up to 99.999% for thermally treating some mixed waste streams. Several test programs have demonstrated this level of off-gas mercury control using fixed beds of granular sulfur-impregnated activated carbon. Other results of these tests include: (a) The depth of the mercury control mass transfer zone was less than 15-30 cm for the operating conditions of these tests, (b) MERSORB(reg s ign) carbon can sorb Hg up to 19 wt% of the carbon mass, and (c) the spent carbon retained almost all (98-99.99%) of the Hg; but when even a small fraction of the total Hg dissolves, the spent carbon can fail the TCLP test when the spent carbon contains high Hg concentrations. Localized areas in a carbon bed that become heated through heat of adsorption, to temperatures where oxidation occurs, are referred to as 'bed hot spots.' Carbon bed hot spots must be avoided in processes that treat radioactive and mixed waste. Key to carbon bed hot spot mitigation are (a) designing for sufficient gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) monitoring and control of inlet gas flowrate, temperature, and composition, (c) monitoring and control of in-bed and bed outlet gas temperatures, and (d) most important, monitoring of bed outlet CO concentrations. An increase of CO levels in the off-gas downstream of the carbon bed to levels about 50-100 ppm higher than the inlet CO concentration indicate CO formation in the bed, caused by carbon bed

  13. Mixing ratios of carbon monoxide in the troposphere

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.C.; Steele, L.P. (Univ. of Colorado, Boulder (United States)); Tans, P.P. (NOAA, Boulder, CO (United States))

    1992-12-20

    Carbon monoxide (CO) mixing ratios were measured in air samples collected weekly at eight locations. The air was collected as part of the CMDL/NOAA cooperative flask sampling program (Climate Monitoring and Diagnostics Laboratory, formerly Geophysical Monitoring for Climatic Change, Air Resources Laboratory/National Oceanic and Atmospheric Administration) at Point Barrow, Alaska, Niwot Ridge, Colorado, Mauna Loa and Cape Kumakahi, Hawaii, Guam, Marianas Islands, Christmas Island, Ascension Island and American Samoa. Half-liter or 3-L glass flasks fitted with glass piston stopcocks holding teflon O rings were used for sample collection. CO levels were determined within several weeks of collection using gas chromatography followed by mercuric oxide reduction detection, and mixing ratios were referenced against the CMDL/NOAA carbon monoxide standard scale. During the period of study (mid-1988 through December 1990) CO levels were greatest in the high latitudes of the northern hemisphere (mean mixing ratio from January 1989 to December 1990 at Point Barrow was approximately 154 ppb) and decreased towards the south (mean mixing ratio at Samoa over a similar period was 65 ppb). Mixing ratios varied seasonally, the amplitude of the seasonal cycle was greatest in the north and decreased to the south. Carbon monoxide levels were affected by both local and regional scale processes. The difference in CO levels between northern and southern latitudes also varied seasonally. The greatest difference in CO mixing ratios between Barrow and Samoa was observed during the northern winter (about 150 ppb). The smallest difference, 40 ppb, occurred during the austral winter. The annually averaged CO difference between 71[degrees]N and 14[degrees]S was approximately 90 ppb in both 1989 and 1990; the annually averaged interhemispheric gradient from 71[degrees]N to 41[degrees]S is estimated as approximately 95 ppb. 66 refs., 5 figs., 5 tabs.

  14. Carbon Nano tubes Based Mixed Matrix Membrane for Gas Separation

    International Nuclear Information System (INIS)

    Sanip, S.M.; Ismail, A.F.; Goh, P.S.; Norrdin, M.N.A.; Soga, T.; Tanemura, M.; Yasuhiko, H.

    2011-01-01

    Carbon nano tubes based mixed matrix membrane (MMM) was prepared by the solution casting method in which the functionalized multi walled carbon nano tubes (f-MWNTs) were embedded into the polyimide membrane and the resulting membranes were characterized. The effect of nominal MWNTs content between 0.5 and 1.0 wt % on the gas separation properties were looked into. The morphologies of the MMM also indicated that at 0.7 % loading of f- MWNTs, the structures of the MMM showed uniform finger-like structures which have facilitated the fast gas transport through the polymer matrix. It may also be concluded that addition of open ended and shortened MWNTs to the polymer matrix can improve its permeability by increasing diffusivity through the MWNTs smooth cavity. (author)

  15. Convective mixing length and the galactic carbon to oxygen ratio

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, A; Peimbert, M [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Astronomia

    1981-01-01

    We have studied chemical evolution models, assuming instantaneous recycling, and considering: a) the effects of mass loss both in massive stars and in intermediate mass stars, and b) the initial mass function of the solar neighbourhood (Serrano 1978). From these models we have derived the yields of carbon and oxygen. It is concluded that the condition C/O approximately 0.58 in the solar neighbourhood can only be satisfied if, during advanced stages of stellar evolution of intermediate mass stars, the ratio of the convective mixing length to the pressure scale height is > approximately 2.

  16. Characterization of Black Carbon Mixing State Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Davidovits, P. [Boston College, Chestnut Hill, MA (United States); Lewis, E. R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Onasch, T. B. [Aerodyne Research, Billerica, MA (United States)

    2016-04-01

    Interpreting the temporal relationship between the scattering and incandescence signals recorded by the Single Particle Soot Photometer (SP2), Sedlacek et al. (2012) reported that 60% of the refractory black carbon containing particles in a plume containing biomass burning tracers exhibited non-core-shell structure. Because the relationship between the rBC (refractory black carbon) incandescence and the scattering signals had not been reported in the peer-reviewed literature, and to further evaluate the initial interpretation by Sedlacek et al., a series of experiments was undertaken to investigate black carbon-containing particles of known morphology using Regal black (RB), a proxy for collapsed soot, as the light-absorbing substance to characterize this signal relationship. Particles were formed by coagulation of RB with either a solid substance (sodium chloride or ammonium sulfate) or a liquid substance (dioctyl sebacate), and by condensation with dioctyl sebacate, the latter experiment forming particles in a core-shell configuration. Each particle type experienced fragmentation (observed as negative lagtimes), and each yielded similar lagtime responses in some instances, confounding attempts to differentiate particle morphology using current SP2 lagtime analysis. SP2 operating conditions, specifically laser power and sample flow rate, which in turn affect the particle heating and dissipation rates, play an important role in the behavior of particles in the SP2, including probability of fragmentation. This behavior also depended on the morphology of the particles and on the thermochemical properties of the non-RB substance. Although these influences cannot currently be unambiguously separated, the SP2 analysis may still provide useful information on particle mixing states and black carbon particle sources. This work was communicated in a 2015 publication (Sedlacek et al. 2015)

  17. Hydrogen role in a carbon-free energy mix

    International Nuclear Information System (INIS)

    2014-02-01

    Among the energy storage technologies under development today, there is today an increasing interest towards the hydrogen-based ones. Hydrogen generation allows to store electricity, while its combustion can supply electrical, mechanical or heat energy. The French Atomic Energy Commission (CEA) started to work on hydrogen technologies at the end of the 1990's in order to reinforce its economical interest. The development of these technologies is one of the 34 French industrial programs presented in September 2013 by the French Minister of productive recovery. This paper aims at identifying the hydrogen stakes in a carbon-free energy mix and at highlighting the remaining technological challenges to be met before reaching an industrial development level

  18. Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

    OpenAIRE

    Chen Kuo-Wei

    2016-01-01

    This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with ...

  19. Effect of carbon on ion beam mixing of Fe-Ti bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, J.P.; Nastasi, M.; Lappalainen, R.; Sickafus, K. (Los Alamos National Lab., NM (USA); Helsinki Univ. (Finland). Dept. of Physics; Los Alamos National Lab., NM (USA))

    1989-01-01

    The influence of implanted carbon on ion beam mixing of a Fe-Ti system was investigated. Carbon was introduced into bilayer samples by implanting {sup 13}C isotopes. The implantation energies were selected to set the mean range of carbon ions in either the iron or titanium layer. The effect of implanted carbon on 400 keV Ar ion mixing in the temperature range from 0 to 300{degree}C was studied using Rutherford backscattering spectroscopy at the energy of 5 MeV. Changes in carbon concentration profiles were probed utilizing the resonance of the nuclear reaction {sup 13}C(p,{gamma}){sup 14}N at the proton energy of 1.748 MeV. The measurements revealed that mixing was not affected by carbon implanted into the titanium layer. However, carbon in the iron layer remarkably retarded mixing at all temperatures investigated. Significant changes in carbon depth distributions were observed only when the sample with implanted carbon in the iron layer was mixed at 300{degree}C. These results are explained in terms of the enhanced mobility of carbon in an evaporated iron film which allows segregation to the interface. At low temperatures, however, vacancy-carbon interaction in iron may have a contribution to the retarded ion beam mixing. 19 refs., 3 figs.

  20. Investigation of bioresistant dry building mixes modified by carbon nanotubes

    OpenAIRE

    Korolev Evgeniy Valer'evich; Erofeev Vladimir Trofimovich; Suraeva Ekaterina Nikolaevna

    2015-01-01

    Dry construction mixes are today a product of high technologies. Depending on the purpose and requirements to the properties it is easy to produce dry construction mixes with different compositions and operating indicators in plant conditions using the necessary modifying additives. Cement, gypsum and other mineral binders are used in the construction mixes. Different types of cement are more heavily used in dry construction mixes. Such dry mixes are believed to be more effective materials co...

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

    OpenAIRE

    Wen-Hsien Tsai; Jui-Chu Chang; Chu-Lun Hsieh; Tsen-Shu Tsaur; Chung-Wei Wang

    2016-01-01

    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 m...

  2. Analysis of refabricated fuel: determination of carbon in uranium plutonium mixed carbide

    International Nuclear Information System (INIS)

    Huwyler, S.

    1977-09-01

    In developing uranium plutonium mixed carbide which represents an advanced fuel for breeder reactors carbon analysis is an important means of determining the stoichiometry. Methods of carbon determination are briefly reviewed. The carbon determination using a LECO WR-12 Carbon Determinator is treated in detail and experience of three years operation communicated. Problems arising from operating the LECO-apparatus in a glove box are discussed. It is pointed out that carbon determination with the LECO-apparatus is a very fast method with good precision and well suited for the routine analysis of mixed carbide fuel. The accuracy of the method is checked by means of a standard. (Auth.)

  3. Mixed resin and carbon fibres surface treatment for preparation of carbon fibres composites with good interfacial bonding strength

    International Nuclear Information System (INIS)

    He, Hongwei; Wang, Jianlong; Li, Kaixi; Wang, Jian; Gu, Jianyu

    2010-01-01

    The objective of this work is to improve the interlaminar shear strength of composites by mixing epoxy resin and modifying carbon fibres. The effect of mixed resin matrix's structure on carbon fibres composites was studied. Anodic oxidation treatment was used to modify the surface of carbon fibres. The tensile strength of multifilament and interlaminar shear strength of composites were investigated respectively. The morphologies of untreated and treated carbon fibres were characterized by scanning electron microscope and X-ray photoelectron spectroscopy. Surface analysis indicates that the amount of carbon fibres chemisorbed oxygen-containing groups, active carbon atom, the surface roughness, and wetting ability increases after treatment. The tensile strength of carbon fibres decreased little after treatment by anodic oxidation. The results show that the treated carbon fibres composites could possess excellent interfacial properties with mixed resins, and interlaminar shear strength of the composites is up to 85.41 MPa. The mechanism of mixed resins and treated carbon fibres to improve the interfacial property of composites is obtained.

  4. Evaluating The Performance of Asphalt Concrete Mixes by Utilizing Carbon Black as Asphalt Modifier

    Directory of Open Access Journals (Sweden)

    Aliaa Faleh Al.ani

    2018-02-01

    Full Text Available Carbon black produced from several factories in Iraq is expected to provide a reinforcing agent for asphalt paving materials. Carbon black has many characteristics that distinguish  it from conventional mineral fillers, as well as their different function in pavement mixtures. Theory and exercise advanced  in the inclusive utilize of carbon black as a reinforcing agent for rubber has led to concept of asphalt reinforcement. The very fine particles of micro filler added in different contents will be dispersed in asphalt cement improving the mechanical properties of asphalt concrete mixes. In this Four percentages rates were utilized; 0, 3, 6, and 9 percent adding to asphalt grade (60-70. Mixes of asphalt concrete were destined at their optimum asphalt content (OAC then experienced to assess their engineering characteristics that contain moisture of damage, permanent deformation, modulus of resilient and characteristics of fatigue. These characteristics have been assessed utilizing indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. Mixtures improved with carbon black were existed to have amended permanent deformation and fatigue characteristics, else exhibited high resilient modulus and lower moisture susceptibility. Result showed that a rate changed from 3 to 9 percent has shown an increase in resilient modulus for increment of carbon black and modulus of resilient for mixes with 9 percent carbon black was 1.4 times that for mixes with 0 percent carbon black. The altering of carbon black from a range (3-9 percent has modified the fatigue property of the asphalt concrete mixes as determined by flexural test, Significantly, to modify the asphalt concrete manner taken the  percent of carbon black 6, and to produce the mixes more durable , higher resistance to distresses by adding the local knowledge.

  5. Isotopic mixing in carbon monoxide catalyzed by zinc oxide

    International Nuclear Information System (INIS)

    Carnisio, G.; Garbassi, F.; Petrini, G.; Parravano, G.

    1978-01-01

    The rate of the isotopic mixing in CO has been studied at 300 0 C, for CO partial pressures from 6 to 100 Torr and a total pressure of 250 Torr on ZnO catalysts. Significant deviations from a first-order rate in p/sub co/ were found. The rate of oxygen exchange between ZnO and gas-phase CO was also measured and the results were employed to calculate the fraction of surface sites active for the CO isotopic mixing. Values on the order of 0.001 were found. The turnover rate and surface collision efficiency varied between 0.7 and 107 min -1 and 0.13 and 2.24 x 10 -8 , respectively. H 2 additions to CO increased the rate of isotopic mixing, whereas the rate of H 2 + D 2 was decreased by the presence of CO. The H 2 + D 2 rate was faster than that of isotopic mixing in CO, but as the ratio p/sub H 2 //p/sub co/ decreased the rates became about equal. It is argued that on ZnO samples, in which the rate of CO isotopic mixing and the rate of ZnO--CO oxygen exchange were influenced in a similar manner by the CO pressure, the isotopic mixing in CO took place via the ZnO oxygen, while oxide oxygen participation was not kinetically significant for ZnO samples in which the two reactions had different kinetics. The crucial factor controlling the path followed by the isotopic mixing in CO seems to be the surface Zn/O ratio, since a close correlation was found between the former and the reaction kinetics of the CO isotopic mixing reaction. Solid-state conditions which may vary the Zn/O surface ratio (foreign additions) are indicated. The implications of these findings to the problem of product selectivity from CO-H 2 mixtures reacting on metal oxide surfaces are discussed

  6. The chlorination kinetics of zirconium dioxide mixed with carbon black

    International Nuclear Information System (INIS)

    Movahedian, A.; Raygan, Sh.; Pourabdoli, M.

    2011-01-01

    In this research, the effects of chlorine gas at different chlorine partial pressures and carbon concentrations on the carbochlorination of zirconia were studied. It was found that in briquettes containing 18.7 %wt carbon, in a chlorine partial pressure range of 0.25-0.75 atm and for a reacted fraction of less than 0.7, the chemical reaction model was dominant for the carbochlorination process of zirconia. The order of reaction into chlorine gas (n) in this situation was 0.57. Moreover, the best weight ratio of carbon to zirconia was 40/60. In this case, the activation energy of the reaction was 209.9 kJ mol -1 in a temperature range of 1023-1223 K, and the dominant model was the chemical reaction model.

  7. Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

    Directory of Open Access Journals (Sweden)

    Chen Kuo-Wei

    2016-01-01

    Full Text Available This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with carbon ash proportion for significant impact. The set density of lightweight brick ameliorates with M3824 additive and CM3 cement mortar for significant impact. Under conditions of technology and economic, the results of this study as reference for market-oriented marketing and commercialization of production.

  8. Carbon emission allowance allocation with a mixed mechanism in air passenger transport.

    Science.gov (United States)

    Qiu, Rui; Xu, Jiuping; Zeng, Ziqiang

    2017-09-15

    Air passenger transport carbon emissions have become a great challenge for both governments and airlines because of rapid developments in the aviation industry in recent decades. In this paper, a mixed mechanism composed of a cap-and-trade mechanism and a carbon tax mechanism is developed to assist governments in allocating carbon emission allowances to airlines operating on the routes. Combined this mixed mechanism with an equilibrium strategy, a bi-level multi-objective model is proposed for an air passenger transport carbon emission allowance allocation problem, in which a government is considered as a leader and the airlines as the followers. An interactive solution approach integrating a genetic algorithm and an interactive evolutionary mechanism is designed to search for satisfactory solutions of the proposed model. A case study is then presented to show its practicality and efficiency in mitigating carbon emissions. Sensitivity analyses under different tradable and taxable levels are also conducted, which can give the government insights as to the tradeoffs between lowering carbon intensity and improving airlines' operations. The computational results demonstrate that the mixed mechanism can assist greatly in carbon emission mitigation for air passenger transport and therefore, it should be established as part of air passenger transport carbon emission policies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Inui, Y. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)]. E-mail: inui@eee.tut.ac.jp; Urata, A. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Ito, N. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Nakajima, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Tanaka, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)

    2006-08-15

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide.

  10. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    International Nuclear Information System (INIS)

    Inui, Y.; Urata, A.; Ito, N.; Nakajima, T.; Tanaka, T.

    2006-01-01

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide

  11. Carbon and nutrient mixed layer dynamics in the Norwegian Sea

    Directory of Open Access Journals (Sweden)

    H. S. Findlay

    2008-10-01

    Full Text Available A coupled carbon-ecosystem model is compared to recent data from Ocean Weather Station M (66° N, 02° E and used as a tool to investigate nutrient and carbon processes within the Norwegian Sea. Nitrate is consumed by phytoplankton in the surface layers over the summer; however the data show that silicate does not become rapidly limiting for diatoms, in contrast to the model prediction and in contrast to data from other temperate locations. The model estimates atmosphere-ocean CO2 flux to be 37 g C m−2 yr−1. The seasonal cycle of the carbonate system at OWS M resembles the cycles suggested by data from other high-latitude ocean locations. The seasonal cycles of calcite saturation state and [CO32-] are similar in the model and in data at OWS M: values range from ~3 and ~120 μmol kg−1 respectively in winter, to ~4 and ~170 μmol kg−1 respectively in summer. The model and data provide further evidence (supporting previous modelling work that the summer is a time of high saturation state within the annual cycle at high-latitude locations. This is also the time of year that coccolithophore blooms occur at high latitudes.

  12. 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.

  13. A study of the mixing state of black carbon in urban zone

    Science.gov (United States)

    Mallet, M.; Roger, J. C.; Despiau, S.; Putaud, J. P.; Dubovik, O.

    2004-02-01

    The knowledge of the mixing state of black carbon particle with other aerosol species is critical for adequate simulations of the direct radiative effect of black carbon particles and its effect on climate. This paper reports the investigation of the mixing state of black carbon aerosol in the urban zone. The study uses a combination of in situ and ground-based remote sensing observations conducted during the ESCOMPTE experiment, which took place in industrialized region in France in summer of 2001. The criteria we used for identifying mixing state relies on the known enhancement of absorption for aerosol composed by internal versus external mixtures of black carbon with weakly absorbing aerosol components. First, using in situ aerosol data, we performed Mie computations and reconstructed the single scattering albedo of aerosol for the two different mixing assumptions: black carbon mixed externally or internally with other aerosol species. Then, we compared the obtained values ωo,int and ωo,ext with the retrievals of ωo from independent AERONET Sun-photometric measurements. The aerosol single scattering albedo (ωo,aer.) derived from the AERONET photometer observations (with the mean value equal to 0.84 ± 0.04) was found to be close to ωo,ext reconstructed from in situ observation under assumptions of external mixture. This similarity between AERONET values and external mixture simulations was observed during all the days studied. Our conclusion on external mixture of black carbon aerosol with other particles in urban zone during ESCOMPTE (close to the pollution source) is coherent with observations made during other independent studies reported in a number of recent publications.

  14. Isopycnal mixing by mesoscale eddies significantly impacts oceanic anthropogenic carbon uptake

    Science.gov (United States)

    Gnanadesikan, Anand; Pradal, Marie-Aude; Abernathey, Ryan

    2015-06-01

    Anthropogenic carbon dioxide uptake varies across Earth System Models for reasons that have remained obscure. When varied within a single model, the lateral eddy mixing coefficient ARedi produces a range of uptake similar to the modeled range. The highest uptake, resulting from a simulation with a constant ARedi of 2400 m2/s, simulates 15% more historical carbon uptake than a model with ARedi = 400 m2/s. A sudden doubling in carbon dioxide produces a 21% range in carbon uptake across the models. Two spatially dependent representations of ARedi produce uptake that lies in the middle of the range of constant values despite predicting very large values in the subtropical gyres. One-dimensional diffusive models of the type used for integrated assessments can be fit to the simulations, with ARedi accounting for a substantial fraction of the effective vertical diffusion. Such models, however, mask significant regional changes in stratification and biological carbon storage.

  15. MATHEMATICAL SIMULATION OF ARGON MIXING PROCESSES AND STEEL SATURATION WITH CARBON IN LADLE

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available The mathematical model for dissolution process of a powder material in steel melt is proposed in the paper. The model permits to take into account mixing hydrodynamics on the basis of the Navier-Stokes equations. One of the industrial out-of-furnace treatment schemes taken as an example demonstrates the opportunities to model a carbon dissolution in a ladle.

  16. High purity samarium oxide from mixed rare earth carbonates

    International Nuclear Information System (INIS)

    Queiroz, Carlos A. da S.; Seneda, Jose A.; Vasconcellos, Mari E. de; Pedreira Filho, Walter dos R.

    2013-01-01

    A simple and economical chemical process for the production of highly pure samarium oxides is discussed. The raw material, which was used in the form of rare earth carbonates was produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography was performed using a strong cationic resin that is typically employed in water treatment processes to fractionate rare earth elements (REE) without the use of retention ions. Under these conditions, 99.9% pure Sm 2 O 3 was eluted using the ammonium salt of ethylenediaminetetraacetic acid (EDTA) at a controlled pH. The EDTA-samarium complex was separated from EDTA and then precipitated as oxalate and fired to samarium oxide. Molecular absorption spectrophotometry was used to monitor the samarium content during the proposed process, and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the samarium oxide. Typical samarium oxide obtained from the proposed procedure contained the following contaminants in micrograms per gram: Sc (20.90); Y (11.80); La (8.4); Ce (4.3); Pr (2.5); Nd (5.1); Eu (94); Gd (114); Tb (3.6); Dy (2.5), Ho (2.3); Er (3.0); Tm (2.3); Yb (38,2); Lu (25.6). The high-purity samarium oxides produced in the present study can be used as an alternative to imported products in research and development applications. (author)

  17. Timescales of carbon turnover in soils with mixed crystalline mineralogies

    Science.gov (United States)

    Khomo, Lesego; Trumbore, Susan; Bern, Carleton R.; Chadwick, Oliver A.

    2017-01-01

    Organic matter-mineral associations stabilize much of the carbon (C) stored globally in soils. Metastable short-range-order (SRO) minerals such as allophane and ferrihydrite provide one mechanism for long-term stabilization of organic matter in young soil. However, in soils with few SRO minerals and a predominance of crystalline aluminosilicate or Fe (and Al) oxyhydroxide, C turnover should be governed by chemisorption with those minerals. Here, we correlate mineral composition from soils containing small amounts of SRO minerals with mean turnover time (TT) of C estimated from radiocarbon (14C) in bulk soil, free light fraction and mineral-associated organic matter. We varied the mineral amount and composition by sampling ancient soils formed on different lithologies in arid to subhumid climates in Kruger National Park (KNP), South Africa. Mineral contents in bulk soils were assessed using chemical extractions to quantify Fe oxyhydroxides and SRO minerals. Because of our interest in the role of silicate clay mineralogy, particularly smectite (2 : 1) and kaolinite (1 : 1), we separately quantified the mineralogy of the clay-sized fraction using X-ray diffraction (XRD) and measured 14C on the same fraction. Density separation demonstrated that mineral associated C accounted for 40-70 % of bulk soil organic C in A and B1 horizons for granite, nephelinite and arid-zone gabbro soils, and > 80 % in other soils. Organic matter strongly associated with the isolated clay-sized fraction represented only 9-47 % of the bulk soil C. The mean TT of C strongly associated with the clay-sized fraction increased with the amount of smectite (2 : 1 clays); in samples with > 40 % smectite it averaged 1020 ± 460 years. The C not strongly associated with clay-sized minerals, including a combination of low-density C, the C associated with minerals of sizes between 2 µm and 2 cm (including Fe oxyhydroxides as coatings), and C removed from clay-sized material by 2 % hydrogen peroxide had

  18. High purity neodymium acetate from mixed rare earth carbonates

    International Nuclear Information System (INIS)

    Queiroz, Carlos A. da Silva; Rocha, Soraya M. Rizzo da; Vasconcellos, Mari E. de; Lobo, Raquel M.; Seneda, Jose A.; Pedreira, Walter dos R.

    2011-01-01

    A simple and economical chemical process for obtaining high purity neodymium acetate is discussed. The raw material in the form rare earth carbonate is produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography technique with a strong cationic resin, proper to water treatment, and without the use of retention ions was used for the fractionating of the rare earth elements (REE). In this way, it was possible to obtain 99.9% pure Nd 2 O 3 in yields greater than or equal 80%, with the elution of the REE using ammonium salt of ethylenediaminetetraacetic acid (EDTA) solution in pH controlled. The complex of EDTA-neodymium was transformed into neodymium oxide, which was subsequently dissolved in acetic acid to obtain the neodymium acetates. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium acetates. The typical neodymium acetates obtained contain the followings contaminants in μg g -1 : Sc(5.1); Y (0.9); La (1.0); Ce (6.1); Pr (34,4); Sm (12.8); Eu (1.1); Gd (15.4); Tb (29.3); Dy (5.2), Ho(7.4); Er (14.6); Tm (0.3); Yb (2.5); Lu (1.0). The high purity neodymium acetates obtained from this procedure have been applied, replacing the imported product, in research and development area on rare earth catalysts. (author)

  19. Timescales of carbon turnover in soils with mixed crystalline mineralogies

    Science.gov (United States)

    Khomo, Lesego; Trumbore, Susan E.; Bern, Carleton R.; Chadwick, Oliver A.

    2017-01-01

    Organic matter–mineral associations stabilize much of the carbon (C) stored globally in soils. Metastable short-range-order (SRO) minerals such as allophane and ferrihydrite provide one mechanism for long-term stabilization of organic matter in young soil. However, in soils with few SRO minerals and a predominance of crystalline aluminosilicate or Fe (and Al) oxyhydroxide, C turnover should be governed by chemisorption with those minerals. Here, we correlate mineral composition from soils containing small amounts of SRO minerals with mean turnover time (TT) of C estimated from radiocarbon (14C) in bulk soil, free light fraction and mineral-associated organic matter. We varied the mineral amount and composition by sampling ancient soils formed on different lithologies in arid to subhumid climates in Kruger National Park (KNP), South Africa. Mineral contents in bulk soils were assessed using chemical extractions to quantify Fe oxyhydroxides and SRO minerals. Because of our interest in the role of silicate clay mineralogy, particularly smectite (2 : 1) and kaolinite (1 : 1), we separately quantified the mineralogy of the clay-sized fraction using X-ray diffraction (XRD) and measured 14C on the same fraction. Density separation demonstrated that mineral associated C accounted for 40–70 % of bulk soil organic C in A and B1 horizons for granite, nephelinite and arid-zone gabbro soils, and > 80 % in other soils. Organic matter strongly associated with the isolated clay-sized fraction represented only 9–47 % of the bulk soil C. The mean TT of C strongly associated with the clay-sized fraction increased with the amount of smectite (2 : 1 clays); in samples with > 40 % smectite it averaged 1020 ± 460 years. The C not strongly associated with clay-sized minerals, including a combination of low-density C, the C associated with minerals of sizes between 2 µm and 2 cm (including Fe oxyhydroxides as coatings), and C removed from clay

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

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2005-01-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  2. Fuel Mix Impacts from Transportation Fuel Carbon Intensity Standards in Multiple Jurisdictions

    Science.gov (United States)

    Witcover, J.

    2017-12-01

    Fuel carbon intensity standards have emerged as an important policy in jurisdictions looking to target transportation greenhouse gas (GHG) emissions for reduction. A carbon intensity standard rates transportation fuels based on analysis of lifecycle GHG emissions, and uses a system of deficits and tradable, bankable credits to reward increased use of fuels with lower carbon intensity ratings while disincentivizing use of fuels with higher carbon intensity ratings such as conventional fossil fuels. Jurisdictions with carbon intensity standards now in effect include California, Oregon, and British Columbia, all requiring 10% reductions in carbon intensity of the transport fuel pool over a 10-year period. The states and province have committed to grow demand for low carbon fuels in the region as part of collaboration on climate change policies. Canada is developing a carbon intensity standard with broader coverage, for fuels used in transport, industry, and buildings. This study shows a changing fuel mix in affected jurisdictions under the policy in terms of shifting contribution of transportation energy from alternative fuels and trends in shares of particular fuel pathways. It contrasts program designs across the jurisdictions with the policy, highlights the opportunities and challenges these pose for the alternative fuel market, and discusses the impact of having multiple policies alongside federal renewable fuel standards and sometimes local carbon pricing regimes. The results show how the market has responded thus far to a policy that incentivizes carbon saving anywhere along the supply chain at lowest cost, in ways that diverged from a priori policy expectations. Lessons for the policies moving forward are discussed.

  3. The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

    Science.gov (United States)

    Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

    2015-08-01

    Three different internal mixing methods (Core-Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20-70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20-50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core-Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC-sulfate aerosol is about -3.18 W/m2 for the external method and -6.91 W/m2 for the internal methods at the surface, and -3.03/-1.56/-1.85 W/m2 for the external/Core-Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause.

  4. Attempts at estimating mixed venous carbon dioxide tension by the single-breath method.

    Science.gov (United States)

    Ohta, H; Takatani, O; Matsuoka, T

    1989-01-01

    The single-breath method was originally proposed by Kim et al. [1] for estimating the blood carbon dioxide tension and cardiac output. Its reliability has not been proven. The present study was undertaken, using dogs, to compare the mixed venous carbon dioxide tension (PVCO2) calculated by the single-breath method with the PVCO2 measured in mixed venous blood, and to evaluate the influence of variations in the exhalation duration and the volume of expired air usually discarded from computations as the deadspace. Among the exhalation durations of 15, 30 and 45 s tested, the 15 s duration was found to be too short to obtain an analyzable O2-CO2 curve, but at either 30 or 45 s, the calculated values of PVCO2 were comparable to the measured PVCO2. A significant agreement between calculated and measured PVCO2 was obtained when the expired gas with PCO2 less than 22 Torr was considered as deadspace gas.

  5. Black carbon mixing state impacts on cloud microphysical properties: effects of aerosol plume and environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ching, Ping Pui; Riemer, Nicole; West, Matthew

    2016-05-27

    Black carbon (BC) is usually mixed with other aerosol species within individual aerosol particles. This mixture, along with the particles' size and morphology, determines the particles' optical and cloud condensation nuclei properties, and hence black carbon's climate impacts. In this study the particle-resolved aerosol model PartMC-MOSAIC was used to quantify the importance of black carbon mixing state for predicting cloud microphysical quantities. Based on a set of about 100 cloud parcel simulations a process level analysis framework was developed to attribute the response in cloud microphysical properties to changes in the underlying aerosol population ("plume effect") and the cloud parcel cooling rate ("parcel effect"). It shows that the response of cloud droplet number concentration to changes in BC emissions depends on the BC mixing state. When the aerosol population contains mainly aged BC particles an increase in BC emission results in increasing cloud droplet number concentrations ("additive effect"). In contrast, when the aerosol population contains mainly fresh BC particles they act as sinks for condensable gaseous species, resulting in a decrease in cloud droplet number concentration as BC emissions are increased ("competition effect"). Additionally, we quantified the error in cloud microphysical quantities when neglecting the information on BC mixing state, which is often done in aerosol models. The errors ranged from -12% to +45% for the cloud droplet number fraction, from 0% to +1022% for the nucleation-scavenged black carbon (BC) mass fraction, from -12% to +4% for the effective radius, and from -30% to +60% for the relative dispersion.

  6. Calcium carbonate-calcium phosphate mixed cement compositions for bone reconstruction.

    Science.gov (United States)

    Combes, C; Bareille, R; Rey, C

    2006-11-01

    The feasibility of making calcium carbonate-calcium phosphate (CaCO(3)-CaP) mixed cements, comprising at least 40% (w/w) CaCO(3) in the dry powder ingredients, has been demonstrated. Several original cement compositions were obtained by mixing metastable crystalline CaCO(3) phases with metastable amorphous or crystalline CaP powders in aqueous medium. The cements set within at most 1 h at 37 degrees C in atmosphere saturated with water. The hardened cement is microporous and exhibits weak compressive strength. The setting reaction appeared to be essentially related to the formation of a highly carbonated nanocrystalline apatite phase by reaction of the metastable CaP phase with part or almost all of the metastable CaCO(3) phase. The recrystallization of metastable CaP varieties led to a final cement consisting of a highly carbonated poorly crystalline apatite analogous to bone mineral associated with various amounts of vaterite and/or aragonite. The presence of controlled amounts of CaCO(3) with a higher solubility than that of the apatite formed in the well-developed CaP cements might be of interest to increase resorption rates in biomedical cement and favors its replacement by bone tissue. Cytotoxicity testing revealed excellent cytocompatibility of CaCO(3)-CaP mixed cement compositions.

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

    Science.gov (United States)

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

    2010-09-15

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

  8. Optics of Water Cloud Droplets Mixed with Black-Carbon Aerosols

    Science.gov (United States)

    Mishchenko, Michael I.; Liu, Li; Cairns, Brian; Mackowski, Daniel W.

    2014-01-01

    We use the recently extended superposition T-matrix method to calculate scattering and absorption properties of micrometer-sized water droplets contaminated by black carbon. Our numerically exact results reveal that, depending on the mode of soot-water mixing, the soot specific absorption can vary by a factor exceeding 6.5. The specific absorption is maximized when the soot material is quasi-uniformly distributed throughout the droplet interior in the form of numerous small monomers. The range of mixing scenarios captured by our computations implies a wide range of remote sensing and radiation budget implications of the presence of black carbon in liquid-water clouds. We show that the popular Maxwell-Garnett effective-medium approximation can be used to calculate the optical cross sections, single-scattering albedo, and asymmetry parameter for the quasi-uniform mixing scenario, but is likely to fail in application to other mixing scenarios and in computations of the elements of the scattering matrix.

  9. Preparation and Characterization of Various Activated Carbons Derived From Mixed Precursors Using Phosphoric Acid

    International Nuclear Information System (INIS)

    Daifullah, A.A.M.; Sharaf El-Deen, S.E.A.; Elkhalafawy, A.; Shehata, F.A.; Mahmoud, W.H.

    2008-01-01

    Rice straw (RS) and rice husk (RH), a low-cost agricultural by-products, have been used as a mixed precursor (i.e., RS mixed with RH in 1:1; 1:3 and 3:1 ratios) for the production of novel carbons using phosphoric acid as chemical activation. The raw materials were impregnated with 50% and 70% H 3 PO 4 followed by activation at 500 degree C. The latter proved to be the most effective in producing active carbon with good adsorptive capacity. The resulting carbons were characterized by elemental analysis, infrared spectroscopy, density, SEM and S BET . In general, the resulting carbons showed reasonable surface areas with mainly micropore structure. The adsorption capacity was demonstrated by the isotherms of methylene blue (MB), phenol and iodine from aqueous solution. The adsorption data was found to conform with the Langmuir equation with the concentration range studied, and the monolayer coverage was determined for each of the samples. It was found that surface area is mainly attributed to micropore volume so that phenol adsorption and iodine number correspond well with surface area determined by nitrogen adsorption

  10. Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

    Science.gov (United States)

    Su, Chao; Chen, Yubo; Wang, Wei; Ran, Ran; Shao, Zongping; Diniz da Costa, João C; Liu, Shaomin

    2014-06-17

    In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects.

  11. Carbon storage as affected by different site preparation techniques two years after mixed forest stand installation

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, F.; Figueiredo, T. de; Martins, A.

    2014-06-01

    Aim of study: This study aims at evaluating the impact of site preparation techniques prior to plantation on carbon storage and distribution in a young mixed stand of Pseudotsuga menziesii (PM) and Castanea sativa (CS). Area of study: The experimental field was established near Macedo de Cavaleiros, Northern Portugal, at 700 m elevation, mean annual temperature 12 degree centigrade and mean annual rainfall 678 mm. Material and methods: The experimental layout includes three replicates, where the different treatments corresponding to different tillage intensities were randomly distributed (high, moderate and slight intensity), in plots with an area of 375 m{sup 2} each. Twenty six months after forest stand installation, samples of herbaceous vegetation (0.49 m{sup 2} quadrat), forest species (8 PM and 8 CS) and mineral soil (at 0-5, 5-15, 15-30 and 30-60 cm depth) were collected in 15 randomly selected points in each treatment, processed in laboratory and analyzed for carbon by elemental carbon analyzer. Main results: The results obtained showed that: (i) more than 90% of the total carbon stored in the system is located in the soil, increasing in depth with tillage intensity; (ii) the contribution of herbaceous vegetation and related roots to the carbon storage is very low; (iii) the amount of carbon per tree is higher in CS than in PM; (iv) the global carbon storage was affected by soil tillage generally decreasing with the increase of tillage intensity. Accordingly, carbon storage capacity as affected by the application of different site preparation techniques should be a decision support tool in afforestation schemes. (Author)

  12. The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

    International Nuclear Information System (INIS)

    Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

    2015-01-01

    Three different internal mixing methods (Core–Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20–70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20–50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core–Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC–sulfate aerosol is about –3.18 W/m 2 for the external method and –6.91 W/m 2 for the internal methods at the surface, and –3.03/–1.56/–1.85 W/m 2 for the external/Core–Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause. - Highlights: • The aerosol optical properties with different mixing

  13. Synthesis of Mixed Carbonates via a Three-Component Coupling of Alcohols, CO2, and Alkyl Halides in the Presence of K2CO3 and Tetrabutylammonium Iodide

    Directory of Open Access Journals (Sweden)

    Yu-Mei Shen

    2002-04-01

    Full Text Available Various mixed carbonates can be conveniently prepared in good yields using the corresponding alcohols, alkyl halides under CO2 atmosphere in the presence of potassium carbonate or sodium carbonate and tetrabutylammonium iodide.

  14. Synthesis of Mixed Carbonates via a Three-Component Coupling of Alcohols, CO2, and Alkyl Halides in the Presence of K2CO3 and Tetrabutylammonium Iodide

    OpenAIRE

    Yu-Mei Shen; Min Shi

    2002-01-01

    Various mixed carbonates can be conveniently prepared in good yields using the corresponding alcohols, alkyl halides under CO2 atmosphere in the presence of potassium carbonate or sodium carbonate and tetrabutylammonium iodide.

  15. Estimating Carbon Dynamics in an Intact Lowland Mixed Dipterocarp Forest Using a Forest Carbon Model

    Directory of Open Access Journals (Sweden)

    Jongyeol Lee

    2017-04-01

    Full Text Available Intact dipterocarp forests in Asia act as crucial carbon (C reservoirs, and it is therefore important to investigate the C dynamics in these forests. We estimated C dynamics, together with net ecosystem production (NEP, in an intact tropical dipterocarp forest of Brunei Darussalam. Fifty-four simulation units (plots; 20 m × 20 m were established and initial C stocks were determined via direct field measurement. The C dynamics were annually simulated with a regression model and the Forest Biomass and Dead organic matter Carbon (FBDC model. The initial C stock (Mg C·ha−1 of biomass, litter, dead wood and mineral soil were 213.1 ± 104.8, 2.0 ± 0.8, 31.3 ± 38.8, and 80.7 ± 15.5, respectively. Their annual changes (Mg C·ha−1·year−1 were 3.2 ± 1.1, 0.2 ± 0.2, −3.7 ± 6.1, and −0.3 ± 1.1, respectively. NEP was −0.6 ± 6.1 Mg C·ha−1·year−1, showing large heterogeneity among the plots. The initial C stocks of biomass and dead wood, biomass turnover rates and dead wood decay rates were elucidated as dominant factors determining NEP in a sensitivity analysis. Accordingly, investigation on those input data can constrain an uncertainty in determining NEP in the intact tropical forests.

  16. Kinetic of formation for single carbon dioxide and mixed carbon dioxide and tetrahydrofuran hydrates in water and sodium chloride aqueous solution

    NARCIS (Netherlands)

    Sabil, K.M.; Duarte, A.R.C.; Zevenbergen, J.F.; Ahmad, M.M.; Yusup, S.; Omar, A.A.; Peters, C.J.

    2010-01-01

    A laboratory-scale reactor system is built and operated to measure the kinetic of formation for single and mixed carbon dioxide-tetrahydrofuran hydrates. The T-cycle method, which is used to collect the kinetic data, is briefly discussed. For single carbon dioxide hydrate, the induction time

  17. Carbon footprint of patient journeys through primary care: a mixed methods approach.

    Science.gov (United States)

    Andrews, Elizabeth; Pearson, David; Kelly, Charlotte; Stroud, Laura; Rivas Perez, Martin

    2013-09-01

    The NHS has a target of cutting its carbon dioxide (CO2) emissions by 80% below 1990 levels by 2050. Travel comprises 17% of the NHS carbon footprint. This carbon footprint represents the total CO2 emissions caused directly or indirectly by the NHS. Patient journeys have previously been planned largely without regard to the environmental impact. The potential contribution of 'avoidable' journeys in primary care is significant. To investigate the carbon footprint of patients travelling to and from a general practice surgery, the issues involved, and potential solutions for reducing patient travel. A mixed methods study in a medium-sized practice in Yorkshire. During March 2012, 306 patients completed a travel survey. GIS maps of patients' travel (modes and distances) were produced. Two focus groups (12 clinical and 13 non-clinical staff) were recorded, transcribed, and analysed using a thematic framework approach. The majority (61%) of patient journeys to and from the surgery were made by car or taxi; main reasons cited were 'convenience', 'time saving', and 'no alternative' for accessing the surgery. Using distances calculated via ArcGIS, the annual estimated CO2 equivalent carbon emissions for the practice totalled approximately 63 tonnes. Predominant themes from interviews related to issues with systems for booking appointments and repeat prescriptions; alternative travel modes; delivering health care; and solutions to reducing travel. The modes and distances of patient travel can be accurately determined and allow appropriate carbon emission calculations for GP practices. Although challenging, there is scope for identifying potential solutions (for example, modifying administration systems and promoting walking) to reduce 'avoidable' journeys and cut carbon emissions while maintaining access to health care.

  18. Distribution and mixing of old and new nonstructural carbon in two temperate trees.

    Science.gov (United States)

    Richardson, Andrew D; Carbone, Mariah S; Huggett, Brett A; Furze, Morgan E; Czimczik, Claudia I; Walker, Jennifer C; Xu, Xiaomei; Schaberg, Paul G; Murakami, Paula

    2015-04-01

    We know surprisingly little about whole-tree nonstructural carbon (NSC; primarily sugars and starch) budgets. Even less well understood is the mixing between recent photosynthetic assimilates (new NSC) and previously stored reserves. And, NSC turnover times are poorly constrained. We characterized the distribution of NSC in the stemwood, branches, and roots of two temperate trees, and we used the continuous label offered by the radiocarbon (carbon-14, (14) C) bomb spike to estimate the mean age of NSC in different tissues. NSC in branches and the outermost stemwood growth rings had the (14) C signature of the current growing season. However, NSC in older aboveground and belowground tissues was enriched in (14) C, indicating that it was produced from older assimilates. Radial patterns of (14) C in stemwood NSC showed strong mixing of NSC across the youngest growth rings, with limited 'mixing in' of younger NSC to older rings. Sugars in the outermost five growth rings, accounting for two-thirds of the stemwood pool, had a mean age  5 yr. Our results are thus consistent with a previously-hypothesized two-pool ('fast' and 'slow' cycling NSC) model structure. These pools appear to be physically distinct. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  19. Role of ocean isopycnal mixing in setting the uptake of anthropogenic carbon

    Science.gov (United States)

    Gnanadesikan, A.; Pradal, M. A. S.; Abernathey, R. P.

    2014-12-01

    The magnitude of the isopycnal stirring coefficient ARedi is poorly constrained from data and varies greatly across Earth System Models. This paper documents the impact of such uncertainty on the oceanic carbon cycle. We compare six spatial representations of ARedi. Four constant values (400, 800, 1200 and 2400 m2/s) are used to explore the difference between using the low values found in many models and the higher values seen in observational estimates. Models are also run with two spatially dependent values of ARedi based on altimetry, one which captures the fully two-dimensional structure of the mixing coefficient, the other of which looks at the zonally averaged structure alone. Under global warming significant changes are seen in the biological pump in convective regions, but these changes are largely locally compensated by changes in preformed DIC. Instead, differences in anthropogenic uptake of carbon are largely centered in the tropics, and can be well described in terms of a relatively simple diffusive approximation. Using ideal age as a tracer can give insight into the expected behavior of the models. The rate of oceanic mixing represents a quantitatively significant uncertainty in future projections of the global carbon cycle, amounting to about 20% of the oceanic uptake.

  20. Carbon capture from natural gas using multi-walled CNTs based mixed matrix membranes.

    Science.gov (United States)

    Hussain, Abid; Farrukh, Sarah; Hussain, Arshad; Ayoub, Muhammad

    2017-12-05

    Most of the polymers and their blends, utilized in carbon capture membranes, are costly, but cellulose acetate (CA) being inexpensive is a lucrative choice. In this research, pure and mixed matrix membranes (MMMs) have been fabricated to capture carbon from natural gas. Polyethylene glycol (PEG) has been utilized in the fabrication of membranes to modify the chain flexibility of polymers. Multi-walled carbon nanotubes (MWCNTs) provide mechanical strength, thermal stability, an extra free path for CO 2 molecules and augment CO 2 /CH 4 selectivity. Membranes of pure CA, CA/PEG blend of different PEG concentrations (5%, 10%, 15%) and CA/PEG/MWCNTs blend of 10% PEG with different MWCNTs concentrations (5%, 10%, 15%) were prepared in acetone using solution casting techniques. Fabricated membranes were characterized using SEM, TGA and tensile testing. Permeation results revealed remarkable improvement in CO 2 /CH 4 selectivity. In single gas experiments, CO 2 /CH 4 selectivity is enhanced 8 times for pure membranes containing 10% PEG and 14 times for MMMs containing 10% MWCNTs. In mix gas experiments, the CO 2 /CH 4 selectivity is increased 13 times for 10% PEG and 18 times for MMMs with 10% MWCNTs. Fabricated MMMs have a tensile strength of 13 MPa and are more thermally stable than CA membranes.

  1. Complexation/encapsulation of green tea polyphenols in mixed calcium carbonate and phosphate micro-particles.

    Science.gov (United States)

    Elabbadi, Amal; Jeckelmann, Nicolas; Haefliger, Olivier P; Ouali, Lahoussine

    2011-01-01

    We used a double-jet mixer to encapsulate water-soluble polyphenols, green tea extract (GTE), with calcium-based inorganic materials. The device mixed calcium chloride solutions with a solution of carbonate and phosphate in the presence of a GTE solution, and formed micro-particles which capture the GTE molecules. The micro-particles were analysed by liquid chromatography coupled to tandem mass spectroscopy to determine the encapsulation yield and loading of the different GTE components. We established correlations between (1) the efficiency of the GTE encapsulation and the composition of the mixed anion solutions and (2) the protonation degree of the ions and the molar ratio of calcium cations and carbonate/phosphate anions. An optimal and reproducible GTE loading of about 40% with an encapsulation yield of 65% was observed for a carbonate/phosphate molar composition of 4 : 1. In addition, our experimental results showed that the process is selective and favours the encapsulation of gallated species which form stronger complexes with calcium cations.

  2. Modeling climate and fuel reduction impacts on mixed-conifer forest carbon stocks in the Sierra Nevada, California

    Science.gov (United States)

    Matthew D. Hurteau; Timothy A. Robards; Donald Stevens; David Saah; Malcolm North; George W. Koch

    2014-01-01

    Quantifying the impacts of changing climatic conditions on forest growth is integral to estimating future forest carbon balance. We used a growth-and-yield model, modified for climate sensitivity, to quantify the effects of altered climate on mixed-conifer forest growth in the Lake Tahoe Basin, California. Estimates of forest growth and live tree carbon stocks were...

  3. Mixed

    Directory of Open Access Journals (Sweden)

    Pau Baya

    2011-05-01

    Full Text Available Remenat (Catalan (Mixed, "revoltillo" (Scrambled in Spanish, is a dish which, in Catalunya, consists of a beaten egg cooked with vegetables or other ingredients, normally prawns or asparagus. It is delicious. Scrambled refers to the action of mixing the beaten egg with other ingredients in a pan, normally using a wooden spoon Thought is frequently an amalgam of past ideas put through a spinner and rhythmically shaken around like a cocktail until a uniform and dense paste is made. This malleable product, rather like a cake mixture can be deformed pulling it out, rolling it around, adapting its shape to the commands of one’s hands or the tool which is being used on it. In the piece Mixed, the contortion of the wood seeks to reproduce the plasticity of this slow heavy movement. Each piece lays itself on the next piece consecutively like a tongue of incandescent lava slowly advancing but with unstoppable inertia.

  4. Numerical modelling of the internal mixing by coagulation of black carbon particles in aircraft exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Ohlsson, S.; Stroem, J. [Stockholm Univ. (Sweden). Dept. of Meteorology

    1997-12-31

    When exhaust gases from an aircraft engine mix with ambient air the humidity may reach water saturation and water droplets will form on the available cloud condensation nuclei (CCN). It is still not resolved if the CCN, on which the cloud droplets form, are mainly particles present in the ambient air or particles emitted by the aircraft. It the exhaust from a jet engine the particles are believed to consist mainly of black carbon (BC) and sulfate. The aim is to study, with the help of a numerical model, how a two-component aerosol (i.e. BC and sulfate) in an exhaust trail may be transformed in terms of hygroscopicity by coagulation mixing and how this may depend on the sulfur content in the fuel. (R.P.) 15 refs.

  5. Numerical modelling of the internal mixing by coagulation of black carbon particles in aircraft exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Ohlsson, S; Stroem, J [Stockholm Univ. (Sweden). Dept. of Meteorology

    1998-12-31

    When exhaust gases from an aircraft engine mix with ambient air the humidity may reach water saturation and water droplets will form on the available cloud condensation nuclei (CCN). It is still not resolved if the CCN, on which the cloud droplets form, are mainly particles present in the ambient air or particles emitted by the aircraft. It the exhaust from a jet engine the particles are believed to consist mainly of black carbon (BC) and sulfate. The aim is to study, with the help of a numerical model, how a two-component aerosol (i.e. BC and sulfate) in an exhaust trail may be transformed in terms of hygroscopicity by coagulation mixing and how this may depend on the sulfur content in the fuel. (R.P.) 15 refs.

  6. Temperature and mixing effects on electrical resistivity of carbon fiber enhanced concrete

    International Nuclear Information System (INIS)

    Chang, Christiana; Song, Gangbing; Gao, Di; Mo, Y L

    2013-01-01

    In this paper, the effect of temperature and mixing procedure on the electrical resistivity of carbon fiber enhanced concrete is investigated. Different compositions of concrete containing varying concentrations of carbon fiber into normal and self-consolidating concrete (SCC) were tested under DC electrical loading over the temperature range −10 to 20 °C. The electrical resistivity of the bulk samples was calculated and compared against temperature. It was observed that there is an inverse exponential relationship between resistivity and temperature which follows the Arrhenius relationship. The bulk resistivity decreased with increasing fiber concentration, though data from SCC indicates a saturation limit beyond which electrical resistivity begins to drop. The activation energy of the bulk electrically conductive concrete was calculated and compared. While SCC exhibited the lowest observed electrical resistance, the activation energy was similar amongst SCC and surfactant enhanced concrete, both of which were lower than fiber dispersed in normal concrete. (paper)

  7. Mechanical performance of styrene-butadiene-rubber filled with carbon nanoparticles prepared by mechanical mixing

    Energy Technology Data Exchange (ETDEWEB)

    Saatchi, M.M. [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of); Shojaei, A., E-mail: akbar.shojaei@sharif.edu [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of)

    2011-09-15

    Highlights: {yields} We compare influence of carbon blacks and carbon nanotube on properties of SBR. {yields} We model mechanical behavior of SBR nanocomposites by the micromechanical model. {yields} Mechanical properties of carbon black/SBR is greatly dominated by bound rubber. {yields} Mechanical properties of SBR/nanotube is governed by big aspect ratio of nanotube. - Abstract: Reinforcement of styrene-butadiene-rubber (SBR) was investigated using two different carbon blacks (CBs) with similar particle sizes, including highly structured CB and conventional CB, as well as multi-walled carbon nanotube (MWCNT) prepared by mechanical mixing. The attempts were made to examine reinforcing mechanism of these two different classes of carbon nanoparticles. Scanning electron microscopy and electrical conductivity measurement were used to investigate morphology. Tensile, cyclic tensile and stress relaxation analyses were performed. A modified Halpin-Tsai model based on the concept of an equivalent composite particle, consisting of rubber bound, occluded rubber and nanoparticle, was proposed. It was found that properties of CB filled SBR are significantly dominated by rubber shell and occluded rubber in which molecular mobility is strictly restricted. At low strains, these rubber constituents can contribute in hydrodynamic effects, leading to higher elastic modulus. However, at higher strains, they contribute in stress hardening resulting in higher elongation at break and higher tensile strength. These elastomeric regions can also influence stress relaxation behaviors of CB filled rubber. For SBR/MWCNT, the extremely great inherent mechanical properties of nanotube along with its big aspect ratio were postulated to be responsible for the reinforcement while their interfacial interaction was not so efficient.

  8. In situ application of activated carbon and biochar to PCB-contaminated soil and the effects of mixing regime

    International Nuclear Information System (INIS)

    Denyes, Mackenzie J.; Rutter, Allison; Zeeb, Barbara A.

    2013-01-01

    The in situ use of carbon amendments such as activated carbon (AC) and biochar to minimize the bioavailability of organic contaminants is gaining in popularity. In the first in situ experiment conducted at a Canadian PCB-contaminated Brownfield site, GAC and two types of biochar were statistically equal at reducing PCB uptake into plants. PCB concentrations in Cucurbita pepo root tissue were reduced by 74%, 72% and 64%, with the addition of 2.8% GAC, Burt's biochar and BlueLeaf biochar, respectively. A complementary greenhouse study which included a bioaccumulation study of Eisenia fetida (earthworm), found mechanically mixing carbon amendments with PCB-contaminated soil (i.e. 24 h at 30 rpm) resulted in shoot, root and worm PCB concentrations 66%, 59% and 39% lower than in the manually mixed treatments (i.e. with a spade and bucket). Therefore, studies which mechanically mix carbon amendments with contaminated soil may over-estimate the short-term potential to reduce PCB bioavailability. Highlights: •Biochar and GAC reduced PCB uptake into plants and earthworms. •Biochar offered additional benefits, including increased plant and earthworm biomass. •BSAF reductions are greater when amendments are mechanically vs. manually mixed. •Mechanically mixing carbon amendments may over-estimate their remediation potential. -- In situ AC and biochar soil amendments perform equally well at reducing PCB uptake, however, laboratory-based mixing methods may exaggerate the sorptive capacities of both amendments

  9. Amine–mixed oxide hybrid materials for carbon dioxide adsorption from CO2/H2 mixture

    Science.gov (United States)

    Ravi, Navin; Aishah Anuar, Siti; Yusuf, Nur Yusra Mt; Isahak, Wan Nor Roslam Wan; Shahbudin Masdar, Mohd

    2018-05-01

    Bio-hydrogen mainly contains hydrogen and high level of carbon dioxide (CO2). High concentration of CO2 lead to a limitation especially in fuel cell application. In this study, the amine-mixed oxide hybrid materials for CO2 separation from bio-hydrogen model (50% CO2:50% H2) have been studied. Fourier-transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) characterizations showed that the amine–mixed oxide hybrid materials successfully adsorbed CO2 physically with no chemical adsorption evidence. The dry gas of CO2/H2 mixture adsorbed physically on amine–CuO–MgO hybrid material. No carbonates were detected after several times of adsorption, which indicated the good recyclability of adsorbents. The adsorbent system of diethanolamine (DEA)/15% CuO–75% MgO showed the highest CO2 adsorption capacity of 21.2 wt% due to the presence of polar substance on MgO surface, which can adsorb CO2 at ambient condition. The alcohol group of DEA can enhance the CO2 solubility on the adsorbent surface. In the 20% CuO–50% MgO adsorbent system, DEA as amine type showed a high CO2 adsorption of 19.4 wt%. The 10% amine loading system showed that the DEA adsorption system provided high CO2 adsorption. The BET analysis confirmed that a high amine loading contributed to the decrease in CO2 adsorption due to the low surface area of the adsorbent system.

  10. Measuring and modeling carbon balance in mountainous Northern Rocky mixed conifer forests

    Science.gov (United States)

    Hudiburg, T. W.; Berardi, D.; Stenzel, J.

    2016-12-01

    Drought and wildfire caused by changing precipitation patterns, increased temperatures, increased fuel loads, and decades of fire suppression are reducing forest carbon uptake from local to continental scales. This trend is especially widespread in Idaho and the intermountain west and has important implications for climate change and forest management options. Given the key role of forests in climate regulation, understanding forest response to drought and the feedbacks to the atmosphere is a key research and policy-relevant priority globally. As temperature, fire, and precipitation regimes continue to change and there is increased risk of forest mortality, measurements and modeling at temporal and spatial scales that are conducive to understanding the impacts and underlying mechanisms of carbon and nutrient cycling become critically important. Until recently, sub-daily measurements of ecosystem carbon balance have been limited in remote, mountainous terrain (e.g Northern Rocky mountain forests). Here, we combine new measurement technology and state-of-the-art ecosystem modeling to determine the impact of drought on the total carbon balance of a mature, mixed-conifer forest in Northern Idaho. Our findings indicate that drought had no impact on aboveground NPP, despite early growing season reductions in soil moisture and fine root biomass compared to non-drought years in the past. Modeled estimates of net ecosystem production (NEP) suggest that a simultaneous reduction in heterotrophic respiration increased the carbon sink for this forest. This has important implications for forest management, such as thinning where the objectives are to increase forest resilience to fire and drought, but may decrease NEP.

  11. Laboratory scale characterizations of the mixing zone for reactive transport in a carbonate system

    International Nuclear Information System (INIS)

    Kassab, M.F.

    2012-01-01

    We have performed laboratory-scale percolation experiments combining hydrodynamic and geochemical reaction processes in a unique setup to study the evolution of permeability induced by dissolution reactions in a natural Carbonate system. First, the key parameters controlling Calcite dissolution due to mixing of two end member solutions representing fresh and sea waters are assessed through typical geochemical modeling. Both solutions are at equilibrium with Calcite and are associated with different values of partial pressure of CO 2 and salinity. Mixing of the two selected end members provides a sub saturated solution with low and moderate ionic strength, high pCO 2 , and high salinity. Modeling results reveal that the maximum sub saturation is expected to occur for mixing ratios of about 15%. The expected dissolved Calcite until equilibrium attains its maximum at a mixing ratio of about 45%. Experimental results indicate that the calcite dissolution rate at a 15% mixing ratio is higher than that observed at 45% mixing ratio. The outlet solution from the sample reactor is always under saturated with respect to Calcite. Permeability of the tested sample displays a rapid decrease during the beginning of injection. It then shows a stable behavior until the end of percolation when the porosity of the sample increases due to dissolution. To understand permeability and porosity evolution obtained from the mixing experiments we perform dissolution experiments under different dissolution regimes by injection of deionized water (DW) and/or DW enriched with CO 2 . It is observed that permeability decreases when DW is injected whereas it increases following injection of DW enriched with CO 2 . The observed global dissolution rate of Calcite is larger for the experiments with DW enriched with CO 2 than for those performed with DW. The observed permeability reduction is due to the clogging of connected pore caused by migration of micro particles detaching from the host porous

  12. Influence of feedstock chemical composition on product formation and characteristics derived from the hydrothermal carbonization of mixed feedstocks.

    Science.gov (United States)

    Lu, Xiaowei; Berge, Nicole D

    2014-08-01

    As the exploration of the carbonization of mixed feedstocks continues, there is a distinct need to understand how feedstock chemical composition and structural complexity influence the composition of generated products. Laboratory experiments were conducted to evaluate the carbonization of pure compounds, mixtures of the pure compounds, and complex feedstocks comprised of the pure compounds (e.g., paper, wood). Results indicate that feedstock properties do influence carbonization product properties. Carbonization product characteristics were predicted using results from the carbonization of the pure compounds and indicate that recovered solids energy contents are more accurately predicted than solid yields and the carbon mass in each phase, while predictions associated with solids surface functional groups are more difficult to predict using this linear approach. To more accurately predict carbonization products, it may be necessary to account for feedstock structure and/or additional feedstock properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Combined electrochemical degradation and activated carbon adsorption treatments for wastewater containing mixed phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Rajkumar, D.; Palanivelu, K.; Balasubramanian, N. [Anna University, Madras (India). Center for Environmental Studies

    2005-01-01

    Electrochemical degradation of mixed phenolic compounds present in coal conversion wastewater was investigated in the presence of chloride as supporting electrolyte. Initially, the degradation experiments were conducted separately with 300 mg/L of individual phenolic compound in the presence of 2500 mg/L chloride using Ti/TiO{sub 2}-RuO{sub 2}-IrO{sub 2} anode at 5.4 A/dm{sup 2} current density. Comparison of the experimental results of the chemical oxygen demand (COD) removal versus charge indicated that the order of decreasing COD removal for various phenolic compounds as catechol {gt} resorcinol {gt} m-cresol {gt} o-cresol {gt} phenol {gt} p-cresol. Degradation of the mixture of phenolic compounds and high-pressure liquid chromatography (HPLC) determinations at various stages of electrolysis showed that phenolic compounds were initially converted into benzoquinone and then to lower molecular weight aliphatic compounds. The COD and the total organic carbon (TOC) removal were 83 and 58.9% after passing 32 Ah/L with energy consumption of 191.6 kWh/kg of COD removal. Experiments were also conducted to remove adsorbable organic halogens (AOX) content in the treated solution using granular activated carbon. The optimum conditions for the removal of AOX was at pH 3.0, 5 mL/min flow rate and 31.2 cm bed height. Based on the investigation, a general scheme of treatment of mixed phenolic compounds by combined electrochemical and activated carbon adsorption treatment is proposed.

  14. Complex resistivity spectra in relation to multiscale pore geometry in carbonates and mixed-siliciclastic rocks

    Science.gov (United States)

    Norbisrath, Jan Henrik

    Carbonate rocks are known to have complex and heterogeneous pore structures, which result from their biogenic origin and strong affinity for diagenetic processes that change their pore structure after burial. The combination of sheer endless variations of precursor biogenic material, depositional environments, and diagenetic effects results in rocks that are interesting to study but intricate to understand. Many schemes to categorize the diversity of carbonate rocks are in use today; most are based on the macropore structure and qualitative thin-section analysis. Many studies, however, acknowledge that micropores have a significant influence on the macroscopic petrophysical rock properties, which are essential to determine reservoir quality. Micropores are, by definition, smaller than the thickness of a thin-section (four major carbonate microporosity types: (1) small intercrystalline, (2) large inter-crystalline, (3) intercement, and (4) micromoldic. Each microporosity type shows a distinct capacity to conduct electrical charge, which largely controls the magnitude and range of cementation factors (m) in rocks with such microporosity type. The BIB-SEM method is also used on a dataset of mixed carbonate-siliciclastic (mudrock) samples with high kerogen and pyrite content. Results show that the nanopore geometry here has little influence on cementation factors, and instead porosity is the main control on m in mudrocks. Cementation factors are crucial for estimates of oil-in-place and water saturation in a wireline application, and a slight change of (assumed) cementation factor can change the interpreter's evaluation from dry hole to discovery. Therefore, accurate determination of cementation factors is a critical task in formation evaluation, similar to accurate estimates of permeability. To achieve this goal, this dissertation utilizes a new approach of using complex resistivity spectra (CRS) to assess the pore geometry and its resulting electrical and fluid flow

  15. Mixed carbonate-siliciclastic sedimentation on a tectonically active margin: Example from the Pliocene of Baja California Sur, Mexico

    Science.gov (United States)

    Dorsey, Rebecca J.; Kidwell, Susan M.

    1999-10-01

    Bioclast-rich, coarse-grained deposits in the Pliocene Loreto basin provide a record of mixed carbonate and siliciclastic sedimentation at the steep hanging-wall margin of this small, fault-controlled basin. Sedimentary facies consist of sand- to gravel-sized carbonate debris mixed with volcaniclastic sand and gravel in a proximal to distal facies tract that includes matrix-rich and matrix-poor shelly conglomerate, impure calcirudite and calcarenite, mixed-composition turbidites, and bioturbated calcarenitic sandstone. Carbonate material was produced by mollusks and other benthic organisms on a narrow, high-energy shelf and mixed with volcaniclastic sand and gravel in cross-shelf channels. These mixtures were transported down a steep subaqueous slope by debris flows, grain flows, and turbidity currents, forming foresets and bottomsets of marine Gilbert-type deltas. This style of mixed carbonate-siliciclastic sedimentation has not been documented in detail elsewhere but should be locally abundant in the stratigraphic record of fault-bounded basins, particularly those with cool or nutrient-rich waters that support relatively few binding and framework-building faunas. Recognition of similar facies in other settings can provide useful insights into ancient conditions of carbonate production, oceanography, climate, and tectonics.

  16. Sequence stratigraphy in a mixed carbonate-silicilastic depositional system (Middle Miocene; Styrian Basin, Austria)

    Science.gov (United States)

    Friebe, J. Georg

    1993-07-01

    The mixed carbonate-siliciclastic Weißenegg (Allo-) Formation records three depositional sequences corresponding approximately to the TB 2.3, TB 2.4 and TB 2.5 global cycles. Sea-level fluctuations were of the order of at least 30 m. Siliciclastic lowstand systems tracts comprise lignite deposits, reworked basement and tidal siltstones (above a tectonically enhanced sequence boundary) as well as coastal sand bars. Coastal sands of the transgressive systems tract contain distinct layers of well cemented nodules. They are interpreted as the first stage in hardground formation and record superimposed minor sea-level fluctuations. Coral patch reefs and rhodolith platforms developed during transgressive phases and were subsequently drowned and/or suffocated by siliciclastics during early highstand. Shallowing upwards siliciclastic parasequences, each terminated by a bank of rhodolith limestone, form the (late) highstand systems tract. The limestone beds record superimposed fourth-order transgressive pulses. Occasionally a carbonate highstand wedge developed. Lowstand carbonate shedding occurred where the top of a platform which suffered incipient drowning during highstand was near sealevel again during the following lowstand. Late highstand delta progradation is common.

  17. Dissolved carbon dynamics in the freshwater-saltwater mixing zone of a coastal river entering the Northern Gulf of Mexico

    Science.gov (United States)

    He, S.; Xu, Y. J.

    2017-12-01

    Estuaries play an important role in the dynamics of dissolved carbon from freshwater to marine systems. This study aims to determine how dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations change along an 88-km long estuarine river with salinity ranging from 0.02 to 29.50. The study is expected to elucidate which processes most likely control carbon dynamics in a freshwater-saltwater mixing system, and to evaluate the net metabolism of this estuary using mixing curves and stable isotope analyses. From November 2014 to February 2016, water samples were collected and in-situ measurements on ambient water conditions were performed during eighteen field trips at six sites from upstream to downstream of the Calcasieu River, which enters the Northern Gulf of Mexico in the southern United States. δ13CDIC and δ13CDOC were measured from May 2015 to February 2017 during five of the field trips. The DIC concentration and δ13CDIC increased rapidly with increasing salinity in the mixing zone. The DIC concentrations appeared to be largely influenced by conservative mixing. The δ13CDIC values were close to those suggested by the conservative mixing model for May 2015, June 2015 and November 2015, but lower than those for July 2015 and February 2016, suggesting that an estuarine river can fluctuate from a balanced to a heterotrophic system (i.e., production/respiration aquatic photosynthesis from carbon produced by terrestrial photosynthesis in a river-ocean continuum. These findings suggest that riverine dissolved carbon undergoes a rapid change in freshwater-saltwater mixing, and that these dynamics should be taken into account in carbon processing and budgeting in the world's estuarine systems.

  18. Sources and mixing state of size-resolved elemental carbon particles in a European megacity: Paris

    Science.gov (United States)

    Healy, R. M.; Sciare, J.; Poulain, L.; Kamili, K.; Merkel, M.; Müller, T.; Wiedensohler, A.; Eckhardt, S.; Stohl, A.; Sarda-Estève, R.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Wenger, J. C.

    2012-02-01

    An Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed to investigate the size-resolved chemical composition of single particles at an urban background site in Paris, France, as part of the MEGAPOLI winter campaign in January/February 2010. ATOFMS particle counts were scaled to match coincident Twin Differential Mobility Particle Sizer (TDMPS) data in order to generate hourly size-resolved mass concentrations for the single particle classes observed. The total scaled ATOFMS particle mass concentration in the size range 150-1067 nm was found to agree very well with the sum of concurrent High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and Multi-Angle Absorption Photometer (MAAP) mass concentration measurements of organic carbon (OC), inorganic ions and black carbon (BC) (R2 = 0.91). Clustering analysis of the ATOFMS single particle mass spectra allowed the separation of elemental carbon (EC) particles into four classes: (i) EC attributed to biomass burning (ECbiomass), (ii) EC attributed to traffic (ECtraffic), (iii) EC internally mixed with OC and ammonium sulfate (ECOCSOx), and (iv) EC internally mixed with OC and ammonium nitrate (ECOCNOx). Average hourly mass concentrations for EC-containing particles detected by the ATOFMS were found to agree reasonably well with semi-continuous quantitative thermal/optical EC and optical BC measurements (r2 = 0.61 and 0.65-0.68 respectively, n = 552). The EC particle mass assigned to fossil fuel and biomass burning sources also agreed reasonably well with BC mass fractions assigned to the same sources using seven-wavelength aethalometer data (r2 = 0.60 and 0.48, respectively, n = 568). Agreement between the ATOFMS and other instrumentation improved noticeably when a period influenced by significantly aged, internally mixed EC particles was removed from the intercomparison. 88% and 12% of EC particle mass was apportioned to fossil fuel and biomass burning respectively using the ATOFMS data

  19. Sources and mixing state of size-resolved elemental carbon particles in a European megacity: Paris

    Directory of Open Access Journals (Sweden)

    R. M. Healy

    2012-02-01

    Full Text Available An Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS was deployed to investigate the size-resolved chemical composition of single particles at an urban background site in Paris, France, as part of the MEGAPOLI winter campaign in January/February 2010. ATOFMS particle counts were scaled to match coincident Twin Differential Mobility Particle Sizer (TDMPS data in order to generate hourly size-resolved mass concentrations for the single particle classes observed. The total scaled ATOFMS particle mass concentration in the size range 150–1067 nm was found to agree very well with the sum of concurrent High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS and Multi-Angle Absorption Photometer (MAAP mass concentration measurements of organic carbon (OC, inorganic ions and black carbon (BC (R2 = 0.91. Clustering analysis of the ATOFMS single particle mass spectra allowed the separation of elemental carbon (EC particles into four classes: (i EC attributed to biomass burning (ECbiomass, (ii EC attributed to traffic (ECtraffic, (iii EC internally mixed with OC and ammonium sulfate (ECOCSOx, and (iv EC internally mixed with OC and ammonium nitrate (ECOCNOx. Average hourly mass concentrations for EC-containing particles detected by the ATOFMS were found to agree reasonably well with semi-continuous quantitative thermal/optical EC and optical BC measurements (r2 = 0.61 and 0.65–0.68 respectively, n = 552. The EC particle mass assigned to fossil fuel and biomass burning sources also agreed reasonably well with BC mass fractions assigned to the same sources using seven-wavelength aethalometer data (r2 = 0.60 and 0.48, respectively, n = 568. Agreement between the ATOFMS and other instrumentation improved noticeably when a period influenced by significantly aged, internally mixed EC particles was removed from the intercomparison. 88% and 12% of EC particle

  20. 1 Mixing state and absorbing properties of black carbon during Arctic haze

    Science.gov (United States)

    Zanatta, Marco; Gysel, Martin; Eleftheriadis, Kosas; Laj, Paolo; Hans-Werner, Jacobi

    2016-04-01

    The Arctic atmosphere is periodically affected by the Arctic haze occurring in spring. One of its particulate components is the black carbon (BC), which is considered to be an important contributor to climate change in the Arctic region. Beside BC-cloud interaction and albedo reduction of snow, BC may influence Arctic climate interacting directly with the solar radiation, warming the corresponding aerosol layer (Flanner, 2013). Such warming depends on BC atmospheric burden and also on the efficiency of BC to absorb light, in fact the light absorption is enhanced by mixing of BC with other atmospheric non-absorbing materials (lensing effect) (Bond et al., 2013). The BC reaching the Arctic is evilly processed, due to long range transport. Aging promote internal mixing and thus absorption enhancement. Such modification of mixing and is quantification after long range transport have been observed in the Atlantic ocean (China et al., 2015) but never investigated in the Arctic. During field experiments conducted at the Zeppelin research site in Svalbard during the 2012 Arctic spring, we investigated the relative precision of different BC measuring techniques; a single particle soot photometer was then used to assess the coating of Arctic black carbon. This allowed quantifying the absorption enhancement induced by internal mixing via optical modelling; the optical assessment of aged black carbon in the arctic will be of major interest for future radiative forcing assessment.Optical characterization of the total aerosol indicated that in 2012 no extreme smoke events took place and that the aerosol population was dominated by fine and non-absorbing particles. Low mean concentration of rBC was found (30 ng m-3), with a mean mass equivalent diameter above 200 nm. rBC concentration detected with the continuous soot monitoring system and the single particle soot photometer was agreeing within 15%. Combining absorption coefficient observed with an aethalometer and rBC mass

  1. Multiple scattering of light by water cloud droplets with external and internal mixing of black carbon aerosols

    International Nuclear Information System (INIS)

    Wang Hai-Hua; Sun Xian-Ming

    2012-01-01

    The mixture of water cloud droplets with black carbon impurities is modeled by external and internal mixing models. The internal mixing model is modeled with a two-layered sphere (water cloud droplets containing black carbon (BC) inclusions), and the single scattering and absorption characteristics are calculated at the visible wavelength of 0.55 μm by using the Lorenz—Mie theory. The external mixing model is developed assuming that the same amount of BC particles are mixed with the water droplets externally. The multiple scattering characteristics are computed by using the Monte Carlo method. The results show that when the size of the BC aerosol is small, the reflection intensity of the internal mixing model is bigger than that of the external mixing model. However, if the size of the BC aerosol is big, the absorption of the internal mixing model will be larger than that of the external mixing model. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  2. Mixed quantum-classical simulations of the vibrational relaxation of photolyzed carbon monoxide in a hemoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, Alexander, E-mail: schubert@irsamc.ups-tlse.fr; Meier, Christoph [Laboratoire Collisions Agrégats et Réactivité, IRSAMC, UMR CNRS 5589, Université Paul Sabatier, 31062 Toulouse (France); Falvo, Cyril [Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay (France)

    2016-08-07

    We present mixed quantum-classical simulations on relaxation and dephasing of vibrationally excited carbon monoxide within a protein environment. The methodology is based on a vibrational surface hopping approach treating the vibrational states of CO quantum mechanically, while all remaining degrees of freedom are described by means of classical molecular dynamics. The CO vibrational states form the “surfaces” for the classical trajectories of protein and solvent atoms. In return, environmentally induced non-adiabatic couplings between these states cause transitions describing the vibrational relaxation from first principles. The molecular dynamics simulation yields a detailed atomistic picture of the energy relaxation pathways, taking the molecular structure and dynamics of the protein and its solvent fully into account. Using the ultrafast photolysis of CO in the hemoprotein FixL as an example, we study the relaxation of vibrationally excited CO and evaluate the role of each of the FixL residues forming the heme pocket.

  3. First-principles study on electron transport properties of carbon-silicon mixed chains

    Science.gov (United States)

    Hu, Wei; Zhou, Qinghua; Liang, Yan; Liu, Wenhua; Wang, Tao; Wan, Haiqing

    2018-03-01

    In this paper, the transport properties of carbon-silicon mixed chains are studied by using the first-principles. We studied five atomic chain models. In these studies, we found that the equilibrium conductances of atomic chains appear to oscillate, the maximum conductance and the minimum conductance are more than twice the difference. Their I-V curves are linear and show the behavior of metal resistance, M5 system and M2 system current ratio is the largest in 0.9 V, which is 3.3, showing a good molecular switch behavior. In the case of bias, while the bias voltage increases, the transmission peaks move from the Fermi level. The resonance transmission peak height is reduced near the Fermi level. In the higher energy range, a large resonance transmission peak reappears, there is still no energy cut-off range.

  4. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin

    2014-08-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, bIm and 2-mbIm in DMF solution at 180 °C. Topological analysis indicated that JUC-160 has a zeolite GIS (gismondine) topology. Study of the gas adsorption and thermal and chemical stability of JUC-160 demonstrated its selective adsorption property for carbon dioxide, high thermal stability, and remarkable chemical resistance to boiling alkaline water and organic solvent for up to one week. © 2014 Elsevier B.V.

  5. A mechanistic model of an upper bound on oceanic carbon export as a function of mixed layer depth and temperature

    Directory of Open Access Journals (Sweden)

    Z. Li

    2017-11-01

    Full Text Available Export production reflects the amount of organic matter transferred from the ocean surface to depth through biological processes. This export is in large part controlled by nutrient and light availability, which are conditioned by mixed layer depth (MLD. In this study, building on Sverdrup's critical depth hypothesis, we derive a mechanistic model of an upper bound on carbon export based on the metabolic balance between photosynthesis and respiration as a function of MLD and temperature. We find that the upper bound is a positively skewed bell-shaped function of MLD. Specifically, the upper bound increases with deepening mixed layers down to a critical depth, beyond which a long tail of decreasing carbon export is associated with increasing heterotrophic activity and decreasing light availability. We also show that in cold regions the upper bound on carbon export decreases with increasing temperature when mixed layers are deep, but increases with temperature when mixed layers are shallow. A meta-analysis shows that our model envelopes field estimates of carbon export from the mixed layer. When compared to satellite export production estimates, our model indicates that export production in some regions of the Southern Ocean, particularly the subantarctic zone, is likely limited by light for a significant portion of the growing season.

  6. Biodegradability of carbon nanotube/polymer nanocomposites under aerobic mixed culture conditions.

    Science.gov (United States)

    Phan, Duc C; Goodwin, David G; Frank, Benjamin P; Bouwer, Edward J; Fairbrother, D Howard

    2018-10-15

    The properties and commercial viability of biodegradable polymers can be significantly enhanced by the incorporation of carbon nanotubes (CNTs). The environmental impact and persistence of these carbon nanotube/polymer nanocomposites (CNT/PNCs) after disposal will be strongly influenced by their microbial interactions, including their biodegradation rates. At the end of consumer use, CNT/PNCs will encounter diverse communities of microorganisms in landfills, surface waters, and wastewater treatment plants. To explore CNT/PNC biodegradation under realistic environmental conditions, the effect of multi-wall CNT (MWCNT) incorporation on the biodegradation of polyhydroxyalkanoates (PHA) was investigated using a mixed culture of microorganisms from wastewater. Relative to unfilled PHA (0% w/w), the MWCNT loading (0.5-10% w/w) had no statistically significant effect on the rate of PHA matrix biodegradation. Independent of the MWCNT loading, the extent of CNT/PNC mass remaining closely corresponded to the initial mass of CNTs in the matrix suggesting a lack of CNT release. CNT/PNC biodegradation was complete in approximately 20 days and resulted in the formation of a compressed CNT mat that retained the shape of the initial CNT/PNC. This study suggests that although CNTs have been shown to be cytotoxic towards a range of different microorganisms, this does not necessarily impact the biodegradation of the surrounding polymer matrix in mixed culture, particularly in situations where the polymer type and/or microbial population favor rapid polymer biodegradation. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Impact of Grain Shape and Multiple Black Carbon Internal Mixing on Snow Albedo: Parameterization and Radiative Effect Analysis

    Science.gov (United States)

    He, Cenlin; Liou, Kuo-Nan; Takano, Yoshi; Yang, Ping; Qi, Ling; Chen, Fei

    2018-01-01

    We quantify the effects of grain shape and multiple black carbon (BC)-snow internal mixing on snow albedo by explicitly resolving shape and mixing structures. Nonspherical snow grains tend to have higher albedos than spheres with the same effective sizes, while the albedo difference due to shape effects increases with grain size, with up to 0.013 and 0.055 for effective radii of 1,000 μm at visible and near-infrared bands, respectively. BC-snow internal mixing reduces snow albedo at wavelengths external mixing, internal mixing enhances snow albedo reduction by a factor of 1.2-2.0 at visible wavelengths depending on BC concentration and snow shape. The opposite effects on albedo reductions due to snow grain nonsphericity and BC-snow internal mixing point toward a careful investigation of these two factors simultaneously in climate modeling. We further develop parameterizations for snow albedo and its reduction by accounting for grain shape and BC-snow internal/external mixing. Combining the parameterizations with BC-in-snow measurements in China, North America, and the Arctic, we estimate that nonspherical snow grains reduce BC-induced albedo radiative effects by up to 50% compared with spherical grains. Moreover, BC-snow internal mixing enhances the albedo effects by up to 30% (130%) for spherical (nonspherical) grains relative to external mixing. The overall uncertainty induced by snow shape and BC-snow mixing state is about 21-32%.

  8. Studies of Carbonization Process on the Production of Durian Peel Biobriquettes with Mixed Biomass Coconut and Palm Shells

    Science.gov (United States)

    Sari, Ellyta; Pasymi; Khatab, Umar; Desmiarti, Reni; Ariansyah, Rian; Hariadi; Sutra

    2018-03-01

    Biobriquettes as alternative energy that can replace the role of kerosene. Biobriquettes made from agricultural waste biomass. Biobriquettes durian peel has been researched and developed continuously to obtain optimal quality in terms of calorific value, compressive strength and duration of ignition. In making durian peel biobriquettes needed other biomass mix to sustain duration of Ignition for biobriquettes durian skin quickly burned out. Stages of making biobriquettes durian skin are: material of drying, carbonization of biomass, grinding, mixing with adhesives, and printing. Carbonization process is a process that is important in obtaining the biomass charcoal. Carbonization is done by means of karbonisator pyrolysis. The purpose of this research is to study the process of carbonization to obtain biobriquettes durian skin that of quality in terms of value compressive strength, calorific value, and duration of ignition. Variations that done was kind mix of biomass,coconut shells and palm shells with the massa ratio 2 : 1, type of adhesive used tapioca powder and banana peels, carbonization of temperature 200°C. 300°C and 400 °C. The results showed that the highest compressive strength of the durian skin with a mixture of coconut shell and adhesive tapioca powder and carbonization temperature of 300 °C namely 12,7 g/cm2. The calorific value of the highest on the mix of skin durian with coconut shells and adhesive banana skin with temperature of carbonization 400 °C ie 6040 cal/g, and duration of ignition highest on a mixture of skin durian with coconut shell and adhesive banana skin at a temperature of carbonization 300 °C is 73 minutes.

  9. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-09-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA

  10. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the UK

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-05-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the UK. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in

  11. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Directory of Open Access Journals (Sweden)

    G. R. McMeeking

    2011-09-01

    Full Text Available Black carbon (BC aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2 measurements of refractory BC (rBC mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA operated by the Facility for Airborne Atmospheric Measurements (FAAM. We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS and used positive matrix factorization to separate hydrocarbon-like (HOA and oxygenated organic aerosols (OOA. We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA did change for

  12. Mixed Matrix Carbon Molecular Sieve and Alumina (CMS-Al2O3) Membranes.

    Science.gov (United States)

    Song, Yingjun; Wang, David K; Birkett, Greg; Martens, Wayde; Duke, Mikel C; Smart, Simon; Diniz da Costa, João C

    2016-07-29

    This work shows mixed matrix inorganic membranes prepared by the vacuum-assisted impregnation method, where phenolic resin precursors filled the pore of α-alumina substrates. Upon carbonisation, the phenolic resin decomposed into several fragments derived from the backbone of the resin matrix. The final stages of decomposition (>650 °C) led to a formation of carbon molecular sieve (CMS) structures, reaching the lowest average pore sizes of ~5 Å at carbonisation temperatures of 700 °C. The combination of vacuum-assisted impregnation and carbonisation led to the formation of mixed matrix of CMS and α-alumina particles (CMS-Al2O3) in a single membrane. These membranes were tested for pervaporative desalination and gave very high water fluxes of up to 25 kg m(-2) h(-1) for seawater (NaCl 3.5 wt%) at 75 °C. Salt rejection was also very high varying between 93-99% depending on temperature and feed salt concentration. Interestingly, the water fluxes remained almost constant and were not affected as feed salt concentration increased from 0.3, 1 and 3.5 wt%.

  13. Carbon dioxide capture from reforming gases using acetic acid-mixed chemical absorbents

    Energy Technology Data Exchange (ETDEWEB)

    Rahmanian, Amin; Zaini, Muhammad Abbas ahmad; Abdullah, Tuan Amran Tuan [Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Johor Bahru (Malaysia)

    2015-07-15

    Carbon dioxide (CO{sub 2}) is a major problem in the production of natural gas as it may contribute to the operational problems such as foaming, corrosion, high solution viscosity, and fouling, thereby decreasing the plant life. The presence of acid gas in natural gas reforming may also result in the increase of transported gas volume and the decrease of heating value. Absorption using aqueous solutions of alkanolamines has been a preferred approach in current industry for CO{sub 2} removal. Concentration of ammonia and DEA affects the CO{sub 2} removal; increasing the absorbents concentration increases the CO{sub 2} removal. On molar basis, DEA shows a greater CO{sub 2} absorption than ammonia. Acetic acid-mixed absorbents display a lower CO{sub 2} removal than the nonmixed ones. Decrease in solubility due to the decrease in solution pH has resulted in a lower CO{sub 2} absorption by acetic acid-mixed absorbents. Liquid flow rate offers only small influence on the absorption of CO{sub 2}, while decreasing the gas flow rate increases the CO{sub 2} removal. On the operational point of view, blend of ammonia and DEA absorbent would be beneficial for CO{sub 2} removal from reforming gases as it could partly solve the problems associated with regeneration and corrosion.

  14. Debates of the Vista 2011 Colloquium 'Towards a low carbon energy mix: which role for nuclear?'

    International Nuclear Information System (INIS)

    Barre, Bertrand; Garribba, Massimo; ); Poyer, Luc; Bigot, Bernard; Ducre, Henri; Giraud, Yves; Wehrling, Yann

    2011-12-01

    During two debates (the first one addresses stakes and challenges at the international level, and the second one addresses the French context), the interveners discuss the evolution of energy mixes at the international level and the share of nuclear energy. They address the conditions under which several energy types are being or can be used within the frame of energy transition, and in a context where the growth of energy consumption is mainly due the development of emerging countries. They discuss how western countries will be able to finance huge investments required by the climate challenge for the development of low carbon energies and energy efficiency in a context of economic recession. They discuss the issue of nuclear energy safety after Fukushima, how the share of nuclear energy could be decreased and whether it is possible, which will be the role of renewable energies, how energy mixes are organised at the international level (different approaches in different countries, differences between France and Germany in a European context). They also address the issues related to the EPR (costs, perspectives)

  15. Hanford/Rocky Flats collaboration on development of supercritical carbon dioxide extraction to treat mixed waste

    International Nuclear Information System (INIS)

    Hendrickson, D.W.; Biyani, R.K.; Brown, C.M.; Teter, W.L.

    1995-11-01

    Proposals for demonstration work under the Department of Energy's Mixed Waste Focus Area, during the 1996 through 1997 fiscal years included two applications of supercritical carbon dioxide to mixed waste pretreatment. These proposals included task RF15MW58 of Rocky Flats and task RL46MW59 of Hanford. Analysis of compatibilities in wastes and work scopes yielded an expectation of substantial collaboration between sites whereby Hanford waste streams may undergo demonstration testing at Rocky Flats, thereby eliminating the need for test facilities at Hanford. This form of collaboration is premised the continued deployment at Rocky Flats and the capability for Hanford samples to be treated at Rocky Flats. The recent creation of a thermal treatment contract for a facility near Hanford may alleviate the need to conduct organic extraction upon Rocky Flats wastes by providing a cost effective thermal treatment alternative, however, some waste streams at Hanford will continue to require organic extraction. Final site waste stream treatment locations are not within the scope of this document

  16. Hanford/Rocky Flats collaboration on development of supercritical carbon dioxide extraction to treat mixed waste

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, D.W.; Biyani, R.K. [Westinghouse Hanford Co., Richland, WA (United States); Brown, C.M.; Teter, W.L. [Kaiser-Hill Co., Golden, CO (United States)

    1995-11-01

    Proposals for demonstration work under the Department of Energy`s Mixed Waste Focus Area, during the 1996 through 1997 fiscal years included two applications of supercritical carbon dioxide to mixed waste pretreatment. These proposals included task RF15MW58 of Rocky Flats and task RL46MW59 of Hanford. Analysis of compatibilities in wastes and work scopes yielded an expectation of substantial collaboration between sites whereby Hanford waste streams may undergo demonstration testing at Rocky Flats, thereby eliminating the need for test facilities at Hanford. This form of collaboration is premised the continued deployment at Rocky Flats and the capability for Hanford samples to be treated at Rocky Flats. The recent creation of a thermal treatment contract for a facility near Hanford may alleviate the need to conduct organic extraction upon Rocky Flats wastes by providing a cost effective thermal treatment alternative, however, some waste streams at Hanford will continue to require organic extraction. Final site waste stream treatment locations are not within the scope of this document.

  17. Enhanced light absorption due to the mixing state of black carbon in fresh biomass burning emissions

    Science.gov (United States)

    Wang, Qiyuan; Cao, Junji; Han, Yongming; Tian, Jie; Zhang, Yue; Pongpiachan, Siwatt; Zhang, Yonggang; Li, Li; Niu, Xinyi; Shen, Zhenxing; Zhao, Zhuzi; Tipmanee, Danai; Bunsomboonsakul, Suratta; Chen, Yang; Sun, Jian

    2018-05-01

    A lack of information on the radiative effects of refractory black carbon (rBC) emitted from biomass burning is a significant gap in our understanding of climate change. A custom-made combustion chamber was used to simulate the open burning of crop residues and investigate the impacts of rBC size and mixing state on the particles' optical properties. Average rBC mass median diameters ranged from 141 to 162 nm for the rBC produced from different types of crop residues. The number fraction of thickly-coated rBC varied from 53 to 64%, suggesting that a majority of the freshly emitted rBC were internally mixed. By comparing the result of observed mass absorption cross-section to that calculated with Mie theory, large light absorption enhancement factors (1.7-1.9) were found for coated particles relative to uncoated cores. These effects were strongly positively correlated with the percentage of coated particles but independent of rBC core size. We suggest that rBC from open biomass burning may have strong impact on air pollution and radiative forcing immediately after their production.

  18. A New Method to Obtain the Black Carbon Mixing State of Biomass and Combustion Aerosols

    Science.gov (United States)

    Irwin, M.; Liu, D.; Joshi, R.; Allan, J. D.; Coe, H.; Flynn, M.; Olfert, J. S.; Broda, K.; Fu, P.; Sun, Y.; Ge, X.; Wang, J.

    2017-12-01

    Black carbon particles (BC) significantly contribute to warming effects in the atmosphere, altering weather systems, and pose significant health risks. These impacts are especially efficient at regional hotspots with high emissions of pollutants, such as in fast-developing megacities. These urban environments have the most population exposure, and improving the understanding of the sources and the processing of pollutants in these environments is critical in guiding policy making. Here we present the results of BC characterization in Beijing during the winter of 2016 (10th Nov-10th Dec), as part of a large joint UK-China field experiment. During this experiment, we successfully gathered 4 weeks of continuous measurements, including several severe pollution events in Beijing. MethodologyThe mixing state of BC, which is how BC is associated with non-BC material (its coating) within a particle, is crucial to determine its lifetime in the atmosphere and also its optical properties. However precisely quantifying the BC mixing state has posed a challenge, in part due to complex particle morphology. We have applied morphology-independent measurements of BC mixing state on a single-particle basis throughout this experiment: mono-dispersed particle mass (MP) is selected using a Centrifugal Particle Mass Analyser (CPMA, Cambustion Ltd) and a single particle soot photometer (SP2, DMT inc.) was used downstream of the CPMA to measure the refractory BC mass (MrBC). The full scan of CPMA masses (21 mass bins covering most of MP) are performed every half hour, following polydispersed particles measured without running CPMA.

  19. Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation

    DEFF Research Database (Denmark)

    Acharya, Bharat Sharma; Rasmussen, Jim; Eriksen, Jørgen

    2012-01-01

    Grasslands are potential carbon sinks to reduce unprecedented increase in atmospheric CO2. Effect of age (1–4-year-old) and management (slurry, grazing multispecies mixture) of a grass phase mixed crop rotation on carbon sequestration and emissions upon cultivation was compared with 17-year...... biomass was highest in 4-year-old grassland, but all 1–4-year-old grasslands were in between the pea field (0.81 ± 0.094 g kg−1 soil) and the 17-year-old grassland (3.17 ± 0.22 g kg−1 soil). Grazed grasslands had significantly higher root biomass than cut grasslands. There was no significant difference...... in the CO2 emissions within 1–4-year-old grasslands. Only the 17-year-old grassland showed markedly higher CO2 emissions (4.9 ± 1.1 g CO2 kg−1 soil). Differences in aboveground and root biomass did not affect CO2 emissions, and slurry application did not either. The substantial increase in root biomass...

  20. Surface Complexation Modeling of Calcite Zeta Potential Measurement in Mixed Brines for Carbonate Wettability Characterization

    Science.gov (United States)

    Song, J.; Zeng, Y.; Biswal, S. L.; Hirasaki, G. J.

    2017-12-01

    We presents zeta potential measurements and surface complexation modeling (SCM) of synthetic calcite in various conditions. The systematic zeta potential measurement and the proposed SCM provide insight into the role of four potential determining cations (Mg2+, SO42- , Ca2+ and CO32-) and CO2 partial pressure in calcite surface charge formation and facilitate the revealing of calcite wettability alteration induced by brines with designed ionic composition ("smart water"). Brines with varying potential determining ions (PDI) concentration in two different CO2 partial pressure (PCO2) are investigated in experiments. Then, a double layer SCM is developed to model the zeta potential measurements. Moreover, we propose a definition for contribution of charged surface species and quantitatively analyze the variation of charged species contribution when changing brine composition. After showing our model can accurately predict calcite zeta potential in brines containing mixed PDIs, we apply it to predict zeta potential in ultra-low and pressurized CO2 environments for potential applications in carbonate enhanced oil recovery including miscible CO2 flooding and CO2 sequestration in carbonate reservoirs. Model prediction reveals that pure calcite surface will be positively charged in all investigated brines in pressurized CO2 environment (>1atm). Moreover, the sensitivity of calcite zeta potential to CO2 partial pressure in the various brine is found to be in the sequence of Na2CO3 > Na2SO4 > NaCl > MgCl2 > CaCl2 (Ionic strength=0.1M).

  1. Influence of litter diversity on dissolved organic matter release and soil carbon formation in a mixed beech forest.

    Science.gov (United States)

    Scheibe, Andrea; Gleixner, Gerd

    2014-01-01

    We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica) and ash (Fraxinus excelsior), characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Park (Thuringia, Germany). Litter was added in pure and mixed treatments with either beech or ash labeled with 13C. We collected soil water in 5 cm mineral soil depth below each treatment biweekly and determined dissolved organic carbon (DOC), δ13C values and anion contents. In addition, we measured carbon concentrations and δ13C values in the organic and mineral soil (collected in 1 cm increments) up to 5 cm soil depth at the end of the experiment. Litter-derived C contributes less than 1% to dissolved organic matter (DOM) collected in 5 cm mineral soil depth. Better decomposable ash litter released significantly more (0.50±0.17%) litter carbon than beech litter (0.17±0.07%). All soil layers held in total around 30% of litter-derived carbon, indicating the large retention potential of litter-derived C in the top soil. Interestingly, in mixed (ash and beech litter) treatments we did not find a higher contribution of better decomposable ash-derived carbon in DOM, O horizon or mineral soil. This suggest that the known selective decomposition of better decomposable litter by soil fauna has no or only minor effects on the release and formation of litter-derived DOM and soil organic matter. Overall our experiment showed that 1) litter-derived carbon is of low importance for dissolved organic carbon release and 2) litter of higher decomposability is faster decomposed, but litter diversity does not influence the carbon flow.

  2. Rotational mixing in carbon-enhanced metal-poor stars with s-process enrichment

    Science.gov (United States)

    Matrozis, E.; Stancliffe, R. J.

    2017-10-01

    Carbon-enhanced metal-poor (CEMP) stars with s-process enrichment (CEMP-s) are believed to be the products of mass transfer from an asymptotic giant branch (AGB) companion, which has long since become a white dwarf. The surface abundances of CEMP-s stars are thus commonly assumed to reflect the nucleosynthesis output of the first AGB stars. We have previously shown that, for this to be the case, some physical mechanism must counter atomic diffusion (gravitational settling and radiative levitation) in these nearly fully radiative stars, which otherwise leads to surface abundance anomalies clearly inconsistent with observations. Here we take into account angular momentum accretion by these stars. We compute in detail the evolution of typical CEMP-s stars from the zero-age main sequence, through the mass accretion, and up the red giant branch for a wide range of specific angular momentum ja of the accreted material, corresponding to surface rotation velocities, vrot, between about 0.3 and 300 kms-1. We find that only for ja ≳ 1017 cm2s-1 (vrot > 20 kms-1, depending on mass accreted) angular momentum accretion directly causes chemical dilution of the accreted material. This could nevertheless be relevant to CEMP-s stars, which are observed to rotate more slowly, if they undergo continuous angular momentum loss akin to solar-like stars. In models with rotation velocities characteristic of CEMP-s stars, rotational mixing primarily serves to inhibit atomic diffusion, such that the maximal surface abundance variations (with respect to the composition of the accreted material) prior to first dredge-up remain within about 0.4 dex without thermohaline mixing or about 0.5-1.5 dex with thermohaline mixing. Even in models with the lowest rotation velocities (vrot ≲ 1 kms-1), rotational mixing is able to severely inhibit atomic diffusion, compared to non-rotating models. We thus conclude that it offers a natural solution to the problem posed by atomic diffusion and cannot be

  3. A conceptual framework to quantify the influence of convective boundary layer development on carbon dioxide mixing ratios

    NARCIS (Netherlands)

    Pino, D.; Vilà-Guerau de Arellano, J.; Peters, W.; Schröter, J.; van Heerwaarden, C. C.; Krol, M. C.

    2012-01-01

    Interpretation of observed diurnal carbon dioxide (CO2) mixing ratios near the surface requires knowledge of the local dynamics of the planetary boundary layer. In this paper, we study the relationship between the boundary layer dynamics and the CO2 budget in convective conditions through a newly

  4. The primary results for the mixed carbon material used for high flux steady-state tokamak operation in China

    International Nuclear Information System (INIS)

    Guo, Q.G.; Li, J.G.; Zhai, G.T.; Liu, L.; Song, J.R.; Zhang, L.F.; He, Y.X.; Chen, J.L.

    2001-01-01

    Several types of carbon mixed materials have been developed in China to be used for high flux steady-state tokamak operation. Performance evaluation of these materials is necessary to determine their applicability as PFCs for high flux steady state. This paper describes the primary results of carbon mixed materials and the effects of dopants on properties are primarily discussed. Test results reveal that bulk boronized graphite has excellent physical and mechanical properties while their thermal conductivity is no more than 73 W/m K due to the formation of a uniform boron-carbon solid solution. In case of multi-element doped graphite, titanium dopant or a decreased boron content is favorable to enhance thermal conductivity. A kind of doped graphite has been developed with thermal conductivity as high as 278 W/m K by optimizing the compositions. Correlations among compositions, microstructure and properties of such doped graphite are discussed

  5. Nonstationary porosity evolution in mixing zone in coastal carbonate aquifer using an alternative modeling approach.

    Science.gov (United States)

    Laabidi, Ezzeddine; Bouhlila, Rachida

    2015-07-01

    In the last few decades, hydrogeochemical problems have benefited from the strong interest in numerical modeling. One of the most recognized hydrogeochemical problems is the dissolution of the calcite in the mixing zone below limestone coastal aquifer. In many works, this problem has been modeled using a coupling algorithm between a density-dependent flow model and a geochemical model. A related difficulty is that, because of the high nonlinearity of the coupled set of equations, high computational effort is needed. During calcite dissolution, an increase in permeability can be identified, which can induce an increase in the penetration of the seawater into the aquifer. The majority of the previous studies used a fully coupled reactive transport model in order to model such problem. Romanov and Dreybrodt (J Hydrol 329:661-673, 2006) have used an alternative approach to quantify the porosity evolution in mixing zone below coastal carbonate aquifer at steady state. This approach is based on the analytic solution presented by Phillips (1991) in his book Flow and Reactions in Permeable Rock, which shows that it is possible to decouple the complex set of equation. This equation is proportional to the square of the salinity gradient, which can be calculated using a density driven flow code and to the reaction rate that can be calculated using a geochemical code. In this work, this equation is used in nonstationary step-by-step regime. At each time step, the quantity of the dissolved calcite is quantified, the change of porosity is calculated, and the permeability is updated. The reaction rate, which is the second derivate of the calcium equilibrium concentration in the equation, is calculated using the PHREEQC code (Parkhurst and Apello 1999). This result is used in GEODENS (Bouhlila 1999; Bouhlila and Laabidi 2008) to calculate change of the porosity after calculating the salinity gradient. For the next time step, the same protocol is used but using the updated porosity

  6. Global zero-carbon energy pathways using viable mixes of nuclear and renewables

    International Nuclear Information System (INIS)

    Hong, Sanghyun; Bradshaw, Corey J.A.; Brook, Barry W.

    2015-01-01

    Highlights: • A proper mix of nuclear power and renewables achieves sustainable energy future. • A high nuclear share provides cost and land effectiveness compared to nuclear-free. • Only-renewable mix will increase negative economic and environmental impacts. • A deployment of advanced reactor technologies is essential to overcome limitations. - Abstract: What are the most viable global pathways for a major expansion of zero-carbon emissions electricity sources given the diversity of regional technical, socio-political and economic constraints? We modelled a range of zero-emissions energy scenarios across nations that were designed to meet projected final energy demand in 2060, and optimised to derive the best globally aggregated results in terms of minimising costs and land use (a surrogate for environmental impacts). We found that a delayed energy transition to a zero-emissions pathway will decrease investment costs (−$3,431 billion), but increase cumulative CO 2 emissions (additional 696 Gt). A renewable-only scenario would convert >7.4% of the global land area to energy production, whereas a maximum nuclear scenario would affect <0.4% of land area, including mining, spent-fuel storage, and buffer zones. Moreover, a nuclear-free pathway would involve up to a 50% greater cumulative capital investment compared to a high nuclear penetration scenario ($73.7 trillion). However, for some nations with a high current share of renewables and a low projected future energy demand (e.g., Norway), pursuit of a higher nuclear share is suboptimal. In terms of the time frame for replacement of fossil fuels, achieving a global nuclear share of about 50% by 2060 would be a technically and economically plausible target if progressing at a pace of the average historical growth of nuclear power penetration in France from 1970 to 1986 (0.28 MWh person −1 year -1 ). For effective climate-change mitigation, a high penetration of nuclear in association with a nationally

  7. Utilization of poly(methyl methacrylate) – carbon nanotube and polystyrene – carbon nanotube in situ polymerized composites as masterbatches for melt mixing

    OpenAIRE

    M. Lahelin; M. Annala; J. Seppala

    2012-01-01

    Carbon nanotubes (CNTs) were melt mixed directly or by using an in situ polymerized masterbatch into a matrix polymer, polystyrene (PS) or poly(methyl methacrylate) (PMMA). The mechanical properties of the composites were mostly determined by the amount of CNTs, and not by the use of directly melt mixed CNTs or the use of the masterbatch. In contrast, the electrical resistivity of the composites was dependent on the manner in which the CNTs were added to the matrix polymer. When there was inc...

  8. Long-term progress prediction for the carbon steel corrosion in diluted artificial seawater with and without zinc / sodium carbonate mixed phosphate

    International Nuclear Information System (INIS)

    Fujii, Kazumi; Ishioka, Shinichi; Iwanami, Masaru; Kaneko, Tetsuji; Tanaka, Norihiko; Kawaharada, Yoshiyuki; Yokoyama, Yutaka; Umehara, Ryuji; Kato, Chiaki; Ueno, Fumiyoshi; Fukaya, Yuichi; Kumaga, Katsuhiko

    2017-01-01

    The Fukushima Daiichi Nuclear Power Plants (1F) were damaged by an unprecedented severe accident in the great east Japan earthquake on 11th, March, 2011, and seawater and fresh water were injected as an emergency countermeasure for the core cooling. The primary containment vessels (PCVs), made of carbon steel, were exposed to seawater and fresh water, and have had the possibility of corrosion. The PCVs of 1F are the most important equipment for the core cooling and removal of the fuel debris, the structural integrity of the PCV must be maintained until decommissioning. Therefore, evaluation of PCV carbon steel corrosion behavior is important, as well as evaluation of corrosion inhibitors as one of the corrosion protection methods. In this study, long-term immersion corrosion tests for up to 10000 hours were performed in diluted artificial seawater simulating 1F with and without zinc / sodium carbonate mixed phosphate. Based on the long-term immersion corrosion test results, diagnosis method of the reduction in plate thickness of the nuclear vessel was examined. The validity of the existing corrosion progress models following parabolic rate law was confirmed. The corrosion progress models were also applicable to the corrosion inhibited condition adding zinc / sodium carbonate mixed phosphate. It was found that the corrosion rate of carbon steel drastically fell down by adding this corrosion inhibitor. (author)

  9. Surface and Adsorption Properties of Activated Carbon Fabric Prepared from Cellulosic Polymer: Mixed Activation Method

    Energy Technology Data Exchange (ETDEWEB)

    Bhati, Surendra; Mahur, J. S.; Choubey, O. N. [Barkatullah Univ., Bhopal (India); Dixit, Mahur Savita [Maulana Azad National Institute of Technology, Bhopla (India)

    2013-02-15

    In this study, activated carbon fabric was prepared from a cellulose-based polymer (viscose rayon) via a combination of physical and chemical activation (mixed activation) processes by means of CO{sub 2} as a gasifying agent and surface and adsorption properties were evaluated. Experiments were performed to investigate the consequence of activation temperature (750, 800, 850 and 925 .deg. C), activation time (15, 30, 45 and 60 minutes) and CO{sub 2} flow rate (100, 200, 300 and 400 mL/min) on the surface and adsorption properties of ACF. The nitrogen adsorption isotherm at 77 K was measured and used for the determination of surface area, total pore volume, micropore volume, mesopore volume and pore size distribution using BET, t-plot, DR, BJH and DFT methods, respectively. It was observed that BET surface area and TPV increase with rising activation temperature and time due to the formation of new pores and the alteration of micropores into mesopores. It was also found that activation temperature dominantly affects the surface properties of ACF. The adsorption of iodine and CCl{sub 4} onto ACF was investigated and both were found to correlate with surface area.

  10. Functionalized carbon nanotubes mixed matrix membranes of polymers of intrinsic microporosity for gas separation.

    Science.gov (United States)

    Khan, Muntazim Munir; Filiz, Volkan; Bengtson, Gisela; Shishatskiy, Sergey; Rahman, Mushfequr; Abetz, Volker

    2012-09-06

    The present work reports on the gas transport behavior of mixed matrix membranes (MMM) which were prepared from multi-walled carbon nanotubes (MWCNTs) and dispersed within polymers of intrinsic microporosity (PIM-1) matrix. The MWCNTs were chemically functionalized with poly(ethylene glycol) (PEG) for a better dispersion in the polymer matrix. MMM-incorporating functionalized MWCNTs (f-MWCNTs) were fabricated by dip-coating method using microporous polyacrylonitrile membrane as a support and were characterized for gas separation performance. Gas permeation measurements show that MMM incorporated with pristine or functionalized MWCNTs exhibited improved gas separation performance compared to pure PIM-1. The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs. The gas permeances of the derived MMM are increased to approximately 50% without sacrificing the selectivity at 2 wt.% of f-MWCNTs' loading. The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity. The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1. The high permeance, selectivity, and long term stability of the fabricated MMM suggest that the reported approach can be utilized in practical gas separation technology.

  11. Surface and Adsorption Properties of Activated Carbon Fabric Prepared from Cellulosic Polymer: Mixed Activation Method

    International Nuclear Information System (INIS)

    Bhati, Surendra; Mahur, J. S.; Choubey, O. N.; Dixit, Mahur Savita

    2013-01-01

    In this study, activated carbon fabric was prepared from a cellulose-based polymer (viscose rayon) via a combination of physical and chemical activation (mixed activation) processes by means of CO 2 as a gasifying agent and surface and adsorption properties were evaluated. Experiments were performed to investigate the consequence of activation temperature (750, 800, 850 and 925 .deg. C), activation time (15, 30, 45 and 60 minutes) and CO 2 flow rate (100, 200, 300 and 400 mL/min) on the surface and adsorption properties of ACF. The nitrogen adsorption isotherm at 77 K was measured and used for the determination of surface area, total pore volume, micropore volume, mesopore volume and pore size distribution using BET, t-plot, DR, BJH and DFT methods, respectively. It was observed that BET surface area and TPV increase with rising activation temperature and time due to the formation of new pores and the alteration of micropores into mesopores. It was also found that activation temperature dominantly affects the surface properties of ACF. The adsorption of iodine and CCl 4 onto ACF was investigated and both were found to correlate with surface area

  12. Indoor and outdoor urban atmospheric CO2: Stable carbon isotope constraints on mixing and mass balance

    International Nuclear Information System (INIS)

    Yanes, Yurena; Yapp, Crayton J.

    2010-01-01

    Research highlights: → 13 C of indoor CO 2 indicates proportion of C 4 -derived carbon in occupants' diet. → Flux balance model for ventilated rooms shows rapid approach to CO 2 steady-state. → From extant indoor CO 2 data more dietary C 4 carbon in American than European diets. → Local outdoor urban CO 2 increase of 17 ppm in ten years, no change in average 13 C. - Abstract: From July to November 2009, concentrations of CO 2 in 78 samples of ambient air collected in 18 different interior spaces on a university campus in Dallas, Texas (USA) ranged from 386 to 1980 ppm. Corresponding δ 13 C values varied from -8.9 per mille to -19.4 per mille. The CO 2 from 22 samples of outdoor air (also collected on campus) had a more limited range of concentrations from 385 to 447 ppm (avg. = 408 ppm), while δ 13 C values varied from -10.1 per mille to -8.4 per mille (avg.=-9.0 per mille). In contrast to ambient indoor and outdoor air, the concentrations of CO 2 exhaled by 38 different individuals ranged from 38,300 to 76,200 ppm (avg. = 55,100 ppm), while δ 13 C values ranged from -24.8 per mille to -17.7 per mille (avg. = -21.8 per mille). The residence times of the total air in the interior spaces of this study appear to have been on the order of 10 min with relatively rapid approaches (∼30 min) to steady-state concentrations of ambient CO 2 gas. Collectively, the δ 13 C values of the indoor CO 2 samples were linearly correlated with the reciprocal of CO 2 concentration, exhibiting an intercept of -21.8 per mille, with r 2 = 0.99 and p 2 data representing 18 interior spaces (with varying numbers of occupants), and the coincidence of the intercept (-21.8 per mille) with the average δ 13 C value for human-exhaled CO 2 demonstrates simple mixing between two inputs: (1) outdoor CO 2 introduced to the interior spaces by ventilation systems, and (2) CO 2 exhaled by human occupants of those spaces. If such simple binary mixing is a common feature of interior spaces, it

  13. Ambient black carbon particle hygroscopic properties controlled by mixing state and composition

    Directory of Open Access Journals (Sweden)

    D. Liu

    2013-02-01

    Full Text Available The wet removal of black carbon aerosol (BC in the atmosphere is a crucial factor in determining its atmospheric lifetime and thereby the vertical and horizontal distributions, dispersion on local and regional scales, and the direct, semi-direct and indirect radiative forcing effects. The in-cloud scavenging and wet deposition rate of freshly emitted hydrophobic BC will be increased on acquisition of more-hydrophilic components by coagulation or coating processes. The lifetime of BC is still subject to considerable uncertainty for most of the model inputs, which is largely due to the insufficient constraints on the BC hydrophobic-to-hydrophilic conversion process from observational field data. This study was conducted at a site along UK North Norfolk coastline, where the BC particles were transported from different regions within Western Europe. A hygroscopicity tandem differential mobility analyser (HTDMA was coupled with a single particle soot photometer (SP2 to measure the hygroscopic properties of BC particles and associated mixing state in real time. In addition, a Soot Particle AMS (SP-AMS measured the chemical compositions of additional material associated with BC particles. The ensemble of BC particles persistently contained a less-hygroscopic mode at a growth factor (gf of around 1.05 at 90% RH (dry diameter 163 nm. Importantly, a more-hygroscopic mode of BC particles was observed throughout the experiment, the gf of these BC particles extended up to ~1.4–1.6 with the minimum between this and the less hygroscopic mode at a gf ~1.25, or equivalent effective hygroscopicity parameter κ ~0.1. The gf of BC particles (gfBC was highly influenced by the composition of associated soluble material: increases of gfBC were associated with secondary inorganic components, and these increases were more pronounced when ammonium nitrate was in the BC particles; however the presence of secondary organic matter suppressed

  14. Crown-To-Rhizosphere Carbon Transfer In A Temperate Mixed Forest

    Science.gov (United States)

    Siegwolf, R. T.; Steinmann, K.; Saurer, M.; Koerner, C.

    2005-12-01

    Flux measurements across a range of (managed) European forests showed that ecosystem respiration amounts up to 80 percent of gross primary production (Janssens et al. 2001), the rest is in large sequestered into biomass. According to Malhi et al. (1999) soil respiration accounts for 60-70 percent of total forest ecosystem respiration. A considerable part is released as CO2 via belowground plant component (autotrophic) and soil micro-organism (heterotrophic) respiration. Recent studies on the autotrophic and heterotrophic respiratory fluxes indicate that the proportion of the autotrophic respiration was most likely underestimated (Hoegberg et al, 2001). Furthermore, highly diverging lengths of time have been estimated between the synthesis of carbohydrates and their availability in the rhizosphere. The goal of the presented study was to i) estimate the transport time for new photosynthates from the leaves to the rhizosphere, ii) determine the spatial distribution of these products, and iii) detect a seasonal course in the autotrophic and heterotrophic respiration of freshly formed assimilates. This study was carried out in a temperate mixed forest (The Swiss Canopy Crane Project in Hofstetten near Basel, Switzerland, cf. Pepin and Koerner 2002, Koerner et al, 2005), exposed to an elevated mean CO2 concentration of 530 ppm. The added CO2 originated from fossil fuel combustion and was depleted in 13C, thus serving as an ideal tracer. Based on the isotopic signature of the soil CO2 it was shown that freshly assimilated carbohydrates were transferred to the rhizosphere within ca. 5 days. The spatial variability was considerable and could mostly be explained with the varying tree population, whereas, the broad-leafed area revealed a more negative d13C value than the conifers. A distinct seasonal course in soil ?13C of the CO2 concentration indicated a seasonal variation in the crown-to-rhizosphere carbon transfer Steinmann et al (2004). Hoegberg P, et al. (2001) Large

  15. Thermal stability and oxidizing properties of mixed alkaline earth-alkali molten carbonates: A focus on the lithium-sodium carbonate eutectic system with magnesium additions

    International Nuclear Information System (INIS)

    Frangini, Stefano; Scaccia, Silvera

    2013-01-01

    Highlights: • TG/DSC analysis was conducted on magnesium-containing eutectic Li/Na eutectic carbonates. • Magnesium influence on the oxygen solubility properties of carbonate was also experimentally determined at 600 °C and 650 °C. • A reproducible partial decarbonation process in premelting region caused formation of magnesium oxycarbonate-like phases. • The acidobase buffering action of magnesium oxycarbonate species could explain the high basic/oxidizing properties of such carbonate melts. • A general correlation between thermal instability in premelting region and basic/oxidizing melt properties was established. - Abstract: A comparative study on thermal behavior and oxygen solubility properties of eutectic 52/48 lithium/sodium carbonate salt containing minor additions of magnesium up to 10 mol% has been made in order to determine whether a general correlation between these two properties can be found or not. Consecutive TG/DSC heating/cooling thermal cycles carried out under alternating CO 2 and N 2 gas flows allowed to assign thermal events observed in the premelting region to a partial decarbonation process of the magnesium-alkali mixed carbonates. The observed decarbonation process at 460 °C is believed to come from initial stage of thermal decomposition of magnesium carbonate resulting in the metastable formation of magnesium oxycarbonate-like phases MgO·2MgCO 3 , in a similar manner as previously reported for lanthanum. Reversible formation and decomposition of the magnesium carbonate phase has been observed under a CO 2 gas atmosphere. The intensity of the decomposition process shows a maximum for a 3 mol% MgO addition that gives also the highest oxygen solubility, suggesting therefore that instability thermal analysis in the premelting region can be considered as providing an effective measure of the basicity/oxidizing properties of alkali carbonate melts with magnesium or, in more general terms, with cations that are strong modifiers of

  16. Mixed Matrix Composite Membranes Containing POSS Molecules for Carbon Dioxide Removal Application

    KAUST Repository

    Rini, Eki Listya

    2011-05-10

    CO2 removal by membrane processes is considerably potential for several applications such as natural gas and synthesis gas purification, enhanced oil recovery application, and carbon dioxide capture in combat against global warming. Dense polymeric membranes are commonly utilized for these type of gas separation applications. Nevertheless, the intrinsic properties of dense polymeric membranes, which commonly characterize by the low gas permeability versus high gas selectivity trade–off or vice versa, is less desirable. In order to meet the increased demand of CO2 removal, a strategy to improve the gas separation performance of a polymeric membrane is investigated in this study. With this regard, mixed matrix membranes in which inorganic non porous fillers are incorporated into a polymeric matrix were prepared to achieve the aforementioned objective. The mixed matrix membranes were prepared from Pebax® block copolymers and PEG POSS® molecules. These hybrid membranes were formed as both dense and multilayer composite membranes. The dense transparent membranes with well–dispersed fillers could be obtained by variation of the solvent mixture. The DSC analyses showed that incorporation of PEG POSS® into Pebax® matrix altered the thermal properties of the matrix. The multilayer composite membranes were then prepared from a PTMSP gutter layer deposited on a PAN porous support and an adjacent hybrid Pebax®/PEG POSS® as the top layer. These hybrid multilayer composite membranes exhibited an enhanced CO2 selectiv4 ity by a factor of two relative to the pure Pebax®. In these hybrid systems, the CO2 separation was presumably enhanced by the high ether oxides content from PEG POSS® that has high affinities for CO2. For particular composition of Pebax® and PEG POSS® concentrations, the PTMSP gutter layer harnessed the CO2 selectivity without losing the CO2 permeation rate. At the same time, these membrane, however, suffered severe adhesion between the gutter layer

  17. 3D carbon/cobalt-nickel mixed-oxide hybrid nanostructured arrays for asymmetric supercapacitors.

    Science.gov (United States)

    Zhu, Jianhui; Jiang, Jian; Sun, Zhipeng; Luo, Jingshan; Fan, Zhanxi; Huang, Xintang; Zhang, Hua; Yu, Ting

    2014-07-23

    The electrochemical performance of supercapacitors relies not only on the exploitation of high-capacity active materials, but also on the rational design of superior electrode architectures. Herein, a novel supercapacitor electrode comprising 3D hierarchical mixed-oxide nanostructured arrays (NAs) of C/CoNi3 O4 is reported. The network-like C/CoNi3 O4 NAs exhibit a relatively high specific surface area; it is fabricated from ultra-robust Co-Ni hydroxide carbonate precursors through glucose-coating and calcination processes. Thanks to their interconnected three-dimensionally arrayed architecture and mesoporous nature, the C/CoNi3 O4 NA electrode exhibits a large specific capacitance of 1299 F/g and a superior rate performance, demonstrating 78% capacity retention even when the discharge current jumps by 100 times. An optimized asymmetric supercapacitor with the C/CoNi3 O4 NAs as the positive electrode is fabricated. This asymmetric supercapacitor can reversibly cycle at a high potential of 1.8 V, showing excellent cycling durability and also enabling a remarkable power density of ∼13 kW/kg with a high energy density of ∼19.2 W·h/kg. Two such supercapacitors linked in series can simultaneously power four distinct light-emitting diode indicators; they can also drive the motor of remote-controlled model planes. This work not only presents the potential of C/CoNi3 O4 NAs in thin-film supercapacitor applications, but it also demonstrates the superiority of electrodes with such a 3D hierarchical architecture. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Fire suppression and fuels treatment effects on mixed-conifer carbon stocks and emissions

    Science.gov (United States)

    M. North; M Hurteau; J Innes

    2009-01-01

    Depending on management, forests can be an important sink or source of carbon that if released as CO2 could contribute to global warming. Many forests in the western United States are being treated to reduce fuels, yet the effects of these treatments on forest carbon are not well understood. We compared the immediate effects of fuels treatments on carbon stocks and...

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

    Science.gov (United States)

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

    2018-02-01

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

  20. Research on Bifurcation and Chaos in a Dynamic Mixed Game System with Oligopolies Under Carbon Emission Constraint

    Science.gov (United States)

    Ma, Junhai; Yang, Wenhui; Lou, Wandong

    This paper establishes an oligopolistic game model under the carbon emission reduction constraint and investigates its complex characteristics like bifurcation and chaos. Two oligopolistic manufacturers comprise three mixed game models, aiming to explore the variation in the status of operating system as per the upgrading of benchmark reward-penalty mechanism. Firstly, we set up these basic models that are respectively distinguished with carbon emission quantity and study these models using different game methods. Then, we concentrate on one typical game model to further study the dynamic complexity of variations in the system status, through 2D bifurcation diagrams and 4D parameter adjustment features based on the bounded rationality scheme for price, and the adaptive scheme for carbon emission. The results show that the carbon emission constraint has significant influence on the status variation of two-oligopolistic game operating systems no matter whether it is stable or chaotic. Besides, the new carbon emission regulation meets government supervision target and achieves the goal of being environment friendly by motivating the system to operate with lower carbon emission.

  1. European transition to a low carbon electricity system using a mix of variable renewable energies: carbon saving trajectories as functions of production and storage capacity.

    Science.gov (United States)

    Francois, Baptiste; Creutin, Jean-Dominique

    2016-04-01

    Today, most of the produced energy is generated from fossil energy sources (i.e. coal, petroleum). As a result, the energy sector is still the main source of greenhouse gas in the atmosphere. For limiting greenhouse gas emission, a transition from fossil to renewable energy is required, increasing gradually the fraction energy coming from variable renewable energy (i.e. solar power, wind power and run-of-the river hydropower, hereafter denoted as VRE). VRE penetration, i.e. the percentage of demand satisfied by variable renewables assuming no storage capacity, is hampered by their variable and un-controllable features. Many studies show that combining different VRE over space smoothes their variability and increases their global penetration by a better match of demand fluctuations. When the demand is not fully supplied by the VRE generation, backup generation is required from stored energy (mostly from dams) or fossil sources, the latter being associated with high greenhouse gas emission. Thus the VRE penetration is a direct indicator of carbon savings and basically depends on the VRE installed capacity, its mix features, and on the installed storage capacity. In this study we analyze the European transition to a low carbon electricity system. Over a selection of representative regions we analyze carbon saving trajectories as functions of VRE production and storage capacities for different scenarios mixing one to three VRE with non-renewables. We show substantial differences between trajectories when the mix of sources is far from the local optimums, when the storage capacity evolves. We bring new elements of reflection about the effect of transport grid features from local independent systems to a European "copper plate". This work is part of the FP7 project COMPLEX (Knowledge based climate mitigation systems for a low carbon economy; Project FP7-ENV-2012 number: 308601; http://www.complex.ac.uk/).

  2. Enhanced solar energy absorption by internally-mixed black carbon in snow grains

    Directory of Open Access Journals (Sweden)

    M. G. Flanner

    2012-05-01

    Full Text Available Here we explore light absorption by snowpack containing black carbon (BC particles residing within ice grains. Basic considerations of particle volumes and BC/snow mass concentrations show that there are generally 0.05–109 BC particles for each ice grain. This suggests that internal BC is likely distributed as multiple inclusions within ice grains, and thus the dynamic effective medium approximation (DEMA (Chýlek and Srivastava, 1983 is a more appropriate optical representation for BC/ice composites than coated-sphere or standard mixing approximations. DEMA calculations show that the 460 nm absorption cross-section of BC/ice composites, normalized to the mass of BC, is typically enhanced by factors of 1.8–2.1 relative to interstitial BC. BC effective radius is the dominant cause of variation in this enhancement, compared with ice grain size and BC volume fraction. We apply two atmospheric aerosol models that simulate interstitial and within-hydrometeor BC lifecycles. Although only ~2% of the atmospheric BC burden is cloud-borne, 71–83% of the BC deposited to global snow and sea-ice surfaces occurs within hydrometeors. Key processes responsible for within-snow BC deposition are development of hydrophilic coatings on BC, activation of liquid droplets, and subsequent snow formation through riming or ice nucleation by other species and aggregation/accretion of ice particles. Applying deposition fields from these aerosol models in offline snow and sea-ice simulations, we calculate that 32–73% of BC in global surface snow resides within ice grains. This fraction is smaller than the within-hydrometeor deposition fraction because meltwater flux preferentially removes internal BC, while sublimation and freezing within snowpack expose internal BC. Incorporating the DEMA into a global climate model, we simulate increases in BC/snow radiative forcing of 43–86%, relative to scenarios that apply external optical properties to all BC. We

  3. Charaterising water-rock interaction in a mixed carbonate-evaporite karstified aquifer system, Qatar

    Science.gov (United States)

    Thirathititham, R.; Whitaker, F.

    2017-12-01

    Qatar is an arid country, most of the rainfall (80 mm/yr) occurring during intense storms. Surface runoff is endorheic and recharge is facilitated by karst features developed over an extended (c.30 Ma) period of exposure of the carbonate bedrock. In December 2016, we sampled a rare intense rainfall event (41 mm over 3 days), after which waters ponded within low-relief terminal depressions prior to infiltration. We compare the chemistry of these recharge waters with that of ground waters from 76 wells distributed across Qatar to understand the nature and spatial distribution of water-rock interaction. Using Cl- as a conservative tracer for seawater mixing, we calculate concentrations of rock-derived Ca2+, Mg2+ and SO42-. During surface detention, rain chemistry is modified by evaporation and interaction with clays and the surface bedrock over days to weeks. However, groundwater chemistry is dominated by subsurface interaction between recharge waters and the karstified Tertiary aquifers. These include the largely dolomitic Paleocene to Lower Eocene Umm er Radhuma (UER) and overlying Lower Eocene Rus, with the Middle Eocene Abarug limestone forming a locally important aquifer in the south west. Away from coastal areas which show clear evidence of salinisation, TDS of groundwaters in the interior of the peninsula increases from north to south. All groundwaters are significantly enriched in SO42-, but this enrichment is marked greater in the south. This likely reflects the presence of a unit of middle Rus gypsum that in the south of the country confines the Lower Rus and UER aquifers, whilst in the north either gypsum was not deposited or has been dissolved. Waters in the Abarug limestone show limited sulfate enrichment and a 1:1 molar ratio of rock-derived SO42-: Ca2+, but across much of the country both SO42- enrichment and SO42-: Ca2+ molar ratio are significantly higher, the latter reaching 2:1 and suggesting an additional sink for Ca2+. The dolomite aquifer waters

  4. Enhanced Solar Energy Absorption by Internally-mixed Black Carbon in Snow Grains

    Energy Technology Data Exchange (ETDEWEB)

    Flanner, M. G.; Liu, Xiaohong; Zhou, Cheng; Penner, Joyce E.; Jiao, C.

    2012-05-30

    Here we explore light absorption by snowpack containing black carbon (BC) particles residing within ice grains. Basic considerations of particle volumes and BC/snow mass concentrations show that there are generally 0:05-109 BC particles for each ice grain. This suggests that internal BC is likely distributed as multiple inclusions within ice grains, and thus the dynamic effective medium approximation (DEMA) (Chylek and Srivastava, 1983) is a more appropriate optical representation for BC/ice composites than coated-sphere or standard mixing approximations. DEMA calculations show that the 460 nm absorption cross-section of BC/ice composites, normalized to the mass of BC, is typically enhanced by factors of 1.8-2.1 relative to interstitial BC. BC effective radius is the dominant cause of variation in this enhancement, compared with ice grain size and BC volume fraction. We apply two atmospheric aerosol models that simulate interstitial and within-hydrometeor BC lifecycles. Although only {approx}2% of the atmospheric BC burden is cloud-borne, 71-83% of the BC deposited to global snow and sea-ice surfaces occurs within hydrometeors. Key processes responsible for within-snow BC deposition are development of hydrophilic coatings on BC, activation of liquid droplets, and subsequent snow formation through riming or ice nucleation by other species and aggregation/accretion of ice particles. Applying deposition fields from these aerosol models in offline snow and sea-ice simulations, we calculate that 32-73% of BC in global surface snow resides within ice grains. This fraction is smaller than the within-hydrometeor deposition fraction because meltwater flux preferentially removes internal BC, while sublimation and freezing within snowpack expose internal BC. Incorporating the DEMA into a global climate model, we simulate increases in BC/snow radiative forcing of 43-86%, relative to scenarios that apply external optical properties to all BC. We show that snow metamorphism

  5. Synthesis of glycerol carbonate by transesterification of glycerol with dimethyl carbonate over MgAl mixed oxide catalysts

    NARCIS (Netherlands)

    Liu, P.; Derchi, M.; Hensen, E.J.M.

    2013-01-01

    A series of hydrotalcite-like layered double hydroxides (LDHx) with different Mg/Al atomic ratios (x = 2–6) were prepared by using the co-precipitation method. Further calcination yields mixed oxides with tunable basicity. The basicity of the calcined LDHx (LDOx) strongly depends on the Mg/Al ratio

  6. Carbon mineralization in surface and subsurface soils in a subtropical mixed forest in central China

    Science.gov (United States)

    Liu, F.; Tian, Q.

    2014-12-01

    About a half of soil carbon is stored in subsurface soil horizons, their dynamics have the potential to significantly affect carbon balancing in terrestrial ecosystems. However, the main factors regulating subsurface soil carbon mineralization are poorly understood. As affected by mountain humid monsoon, the subtropical mountains in central China has an annual precipitation of about 2000 mm, which causes strong leaching of ions and nutrition. The objectives of this study were to monitor subsurface soil carbon mineralization and to determine if it is affected by nutrient limitation. We collected soil samples (up to 1 m deep) at three locations in a small watershed with three soil layers (0-10 cm, 10-30 cm, below 30 cm). For the three layers, soil organic carbon (SOC) ranged from 35.8 to 94.4 mg g-1, total nitrogen ranged from 3.51 to 8.03 mg g-1, microbial biomass carbon (MBC) ranged from 170.6 to 718.4 μg g-1 soil. We measured carbon mineralization with the addition of N (100 μg N/g soil), P (50 μg P/g soil), and liable carbon (glucose labeled by 5 atom% 13C, at five levels: control, 10% MBC, 50% MBC, 100% MBC, 200% MBC). The addition of N and P had negligible effects on CO2 production in surface soil layers; in the deepest soil layer, the addition of N and P decreased CO2 production from 4.32 to 3.20 μg C g-1 soil carbon h-1. Glucose addition stimulated both surface and subsurface microbial mineralization of SOC, causing priming effects. With the increase of glucose addition rate from 10% to 200% MBC, the primed mineralization rate increased from 0.19 to 3.20 μg C g-1 soil carbon h-1 (fifth day of glucose addition). The magnitude of priming effect increased from 28% to 120% as soil layers go deep compare to the basal CO2 production (fifth day of 200% MBC glucose addition, basal CO2 production rate for the surface and the deepest soil was 11.17 and 2.88 μg C g-1 soil carbon h-1). These results suggested that the mineralization of subsurface carbon is more

  7. Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

    KAUST Repository

    Li, Jing; Chen, Fangping; Jin, Guanping; Feng, Xiaoshuang; Li, Xiaoxuan

    2015-01-01

    Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

  8. Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

    KAUST Repository

    Li, Jing

    2015-07-01

    Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

  9. The seasonal cycle of the mixing layer height and its impact on black carbon concentrations in the Kathmandu Valley (Nepal)

    Science.gov (United States)

    Mues, Andrea; Rupakheti, Maheswar; Hoor, Peter; Bozem, Heiko; Münkel, Christoph; Lauer, Axel; Butler, Tim

    2016-04-01

    The properties and the vertical structure of the mixing layer as part of the planetary boundary layer are of key importance for local air quality. They have a substantial impact on the vertical dispersion of pollutants in the lower atmosphere and thus on their concentrations near the surface. In this study, ceilometer measurements taken within the framework of the SusKat project (Sustainable Atmosphere for the Kathmandu Valley) are used to investigate the mixing layer height in the Kathmandu Valley, Nepal. The applied method is based on the assumption that the aerosol concentration is nearly constant in the vertical and distinctly higher within the mixing layer than in the air above. Thus, the height with the steepest gradient within the ceilometer backscatter profile marks the top of the mixing layer. Ceilometer and black carbon (BC) measurements conducted from March 2013 through February 2014 provide a unique and important dataset for the analysis of the meteorological and air quality conditions in the Kathmandu Valley. In this study the mean diurnal cycle of the mixing layer height in the Kathmandu Valley for each season (pre-monsoon, monsoon, post-monsoon and winter season) and its dependency on the meteorological situation is investigated. In addition, the impact of the mixing layer height on the BC concentration is analyzed and compared to the relevance of other important processes such as emissions, horizontal advection and deposition. In all seasons the diurnal cycle is typically characterized by low mixing heights during the night, gradually increasing after sun rise reaching to maximum values in the afternoon before decreasing again. Seasonal differences can be seen particularly in the height of the mixing layer, e.g. from on average 153/1200 m (pre-monsoon) to 241/755 m (monsoon season) during the night/day, and the duration of enhanced mixing layer heights during daytime (around 12 hours (pre-monsoon season) to 8 hours (winter)). During the monsoon

  10. A modified Wyllie equation for the relationship between porosity and sonic velocity of mixed sediments and carbonates from the Caribbean Sea

    DEFF Research Database (Denmark)

    Lind, Ida

    1997-01-01

    Continuous drill cores from the Caribbean Sea of up to 1 km thick mixed sediments and carbonates were recovered by Ocean Drilling Program Leg 165. The sediments range in porosity from 10% to 80% and in carbonate content from 20% to 95%. Unconfined P-wave velocities from this material were measured...

  11. Thermo-mechanical characterization of epoxy nanocomposites with different carbon nanotube distributions obtained by solvent aided and direct mixing.

    Directory of Open Access Journals (Sweden)

    M. Zarrelli

    2012-07-01

    Full Text Available Two different routes, namely solvent aided dispersion and direct mixing, were employed to disperse Multi-Walled Carbon Nanotubes (MWNTs into a mono-component epoxy system used as matrix for advanced composites. In the first route, MWCNTs were diluted in three different solvents (acetone, sodium dodecyl sulfate and ethanol and then mixed with the matrix by tip sonication. In the second case, carbonaceous nanoparticles were added directly into the hosting system and dispersion was carried out by using three different techniques (mechanical stirring, magnetic agitation and tip sonication. The effects of the solvents and agitation energy were investigated by optical microscopy at micron level, in order assess the more efficient dispersion procedure for the considered epoxy system. It was demonstrated that parameters associated with direct mixing rather than solvent solubility govern MWCNT dispersion. Optical analysis of the nanocomposite morphology evidenced a very low density of MWCNTs micron sized aggregates in the case of direct mixed tip sonicated samples if compared to those obtained by solution aided dispersion. In addition, nanocomposites obtained by sonication showed the lowest density of MWCNTs micron sized aggregates, also when compared with mechanically and magnetically stirred system. Dynamic Mechanical Analysis (DMA and Thermo-Mechanical Analysis (TMA results confirm the final result that among the considered direct mixing techniques, the direct tip sonication represents the most efficient route for MWCNT dispersion. Moreover, the mixing temperature of the hosting matrix system represents a fundamental feature in enhancing the MWCNT de-bundling and dispersion. Small X-ray Scattering analysis revealed that a nanosized structure of nanotubes is formed in the case of the tip sonicated samples that is heuristically correlated with both the maximum enhancement of mechanical modulus and the maximum reduction of thermal expansion coefficients.

  12. Effects of internal mixing and aggregate morphology on optical properties of black carbon using a discrete dipole approximation model

    Directory of Open Access Journals (Sweden)

    B. V. Scarnato

    2013-05-01

    Full Text Available According to recent studies, internal mixing of black carbon (BC with other aerosol materials in the atmosphere alters its aggregate shape, absorption of solar radiation, and radiative forcing. These mixing state effects are not yet fully understood. In this study, we characterize the morphology and mixing state of bare BC and BC internally mixed with sodium chloride (NaCl using electron microscopy and examine the sensitivity of optical properties to BC mixing state and aggregate morphology using a discrete dipole approximation model (DDSCAT. DDSCAT is flexible in simulating the geometry and refractive index of particle aggregates. DDSCAT predicts a higher mass absorption coefficient (MAC, lower single scattering albedo (SSA, and higher absorption Angstrom exponent (AAE for bare BC aggregates that are lacy rather than compact. Predicted values of SSA at 550 nm range between 0.16 and 0.27 for lacy and compact aggregates, respectively, in agreement with reported experimental values of 0.25 ± 0.05. The variation in absorption with wavelength does not adhere precisely to a power law relationship over the 200 to 1000 nm range. Consequently, AAE values depend on the wavelength region over which they are computed. The MAC of BC (averaged over the 200–1000 nm range is amplified when internally mixed with NaCl (100–300 nm in radius by factors ranging from 1.0 for lacy BC aggregates partially immersed in NaCl to 2.2 for compact BC aggregates fully immersed in NaCl. The SSA of BC internally mixed with NaCl is higher than for bare BC and increases with the embedding in the NaCl. Internally mixed BC SSA values decrease in the 200–400 nm wavelength range, a feature also common to the optical properties of dust and organics. Linear polarization features are also predicted in DDSCAT and are dependent on particle size and morphology. This study shows that DDSCAT predicts complex morphology and mixing state dependent aerosol optical properties that have

  13. Carbon dioxide selective mixed matrix composite membrane containing ZIF-7 nano-fillers

    KAUST Repository

    Li, Tao; Pan, Yichang; Peinemann, Klaus-Viktor; Lai, Zhiping

    2013-01-01

    Mixed matrix materials made from selective inorganic fillers and polymers are very attractive for the manufacturing of gas separation membranes. But only few of these materials could be manufactured into high-performance asymmetric or composite

  14. Rigid Polyurethane Nanocomposites Prepared by Direct Incorporation: Effects of Nanoclay, Carbon Nanotubes and Mixing Speed on Physical and Morphological Properties

    Science.gov (United States)

    Ramadhoni, Benni; Ujianto, Onny; Nadapdap, Maxwell

    2018-03-01

    Rigid polyurethane (PU) nanocomposites were fabricated via solution mixing of PU, nanoclay and multiwalled carbon nanotubes (MWCNT) according to full factorial DoE. The nanoclay and MWCNT concentration as well as mixing speed were varied. The effects of controlled variables on reduced compressive strength, fire retardancy, hardness and morphological properties were analized. In general, the results showed that incorporation of nanofillers into PU matrix successfully elevated nanocomposites performance. The properties changed from -12% to 45% for reduced compressive strength, 9% to 30% for reduced fire retardancy and -32% to 101% for reduced hardness. The results suggested that the improvements were affected by nanoclay dispersion that acted as nucleating agent which resulted in smaller close cells of PU structures.

  15. Parallel measurements of organic and elemental carbon dry (PM1, PM2.5) and wet (rain, snow, mixed) deposition into the Baltic Sea.

    Science.gov (United States)

    Witkowska, Agnieszka; Lewandowska, Anita; Falkowska, Lucyna M

    2016-03-15

    Parallel studies on organic and elemental carbon in PM1 and PM2.5 aerosols and in wet deposition in various forms of its occurrence were conducted in the urbanised coastal zone of the Baltic Sea. The carbon load introduced into the sea water was mainly affected by the form of precipitation. Dry deposition load of carbon was on average a few orders of magnitude smaller than wet deposition. The suspended organic carbon was more effectively removed from the air with rain than snow, while an inverse relationship was found for elemental carbon. However the highest flux of water insoluble organic carbon was recorded in precipitation of a mixed nature. The atmospheric cleaning of highly dissolved organic carbon was observed to be the most effective on the first day of precipitation, while the hydrophobic elemental carbon was removed more efficiently when the precipitation lasted longer than a day. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Determination of carbon-14 environmental samples by mixing 14CO2 with a liquid scintillator

    International Nuclear Information System (INIS)

    Garcia Sanz, M.R.; Gomez, V.; Heras, M.C.; Beltran, M.A.

    1990-01-01

    A method for the determination of Carbon-14 ( 14 CO 2 ) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO 2 ) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discused and compared. The method of collection of atmospheric samples is also described. (Author)

  17. Determination of Carbon-14 in environmental samples by mixing 14CO2 with a liquid scintillator

    International Nuclear Information System (INIS)

    Garcia, M. R.; Gomez, V.; Heras, M. C.; Beltran, M. A.

    1990-01-01

    A method for the determination of Carbon-14 (14CO2) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO2) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discussed and compared. The method of collection of atmospheric samples is also described. (Author) 10 refs

  18. Investigation of plasma interaction with carbon based and mixed materials related to next-generation fusion devices

    International Nuclear Information System (INIS)

    Guseva, M.I.; Martynenko, Yu.V.; Korshunov, S.N.

    2003-01-01

    Carbon-carbon composites, tungsten and beryllium are considered at present as candidate-materials for International Thermonuclear Experimental Reactor (ITER). The presence of various materials, as the divertor and the first wall components, will unavoidably result in the formation of mixed layers on the surfaces of plasma facing components. In this review, processes of plasma interaction with these materials and layers formed by mixing of the materials are considered. Mixed W-Be and W-C layers were prepared by deposition of two species atoms upon a substrate under simultaneous sputtering of two targets by 20 keV Ar + -ions. The thickness of the deposited mixed layers was 100-500 nm. The most important processes investigated here are: a) erosion at threshold energies and at various temperatures, b) erosion at plasma disruption, c) surface modification at normal operation regime and disruption, d) the influence of the surface modification on material erosion, e) erosion product formation at plasma disruption (dust creation), f) hydrogen isotopes retention in materials. An experimental method of determination of sputtering yield under ion bombardment in the near-threshold energy range has been developed. The method is based on the use of special regimes of field ion microscopic analysis. The method has been used for measurement of the sputtering yield of C-C composite, technically pure tungsten, tungsten oxide and mixed W-C layer on the tungsten by deuterium ions. The energy dependences of the sputtering yield of those materials by deuterium ions at energies ranging from 10 to 500 eV was investigated. Temperature dependences of pure and B-doped C-C composites erosion by deuterium ions were investigated. Material erosion was studied in a steady state plasma at the LENTA facility with parameters close to those expected at normal operation of ITER, and in the MKT plasma accelerator simulating plasma disruption. Surface modifications of graphite materials and tungsten

  19. Utilization of poly(methyl methacrylate – carbon nanotube and polystyrene – carbon nanotube in situ polymerized composites as masterbatches for melt mixing

    Directory of Open Access Journals (Sweden)

    M. Lahelin

    2012-10-01

    Full Text Available Carbon nanotubes (CNTs were melt mixed directly or by using an in situ polymerized masterbatch into a matrix polymer, polystyrene (PS or poly(methyl methacrylate (PMMA. The mechanical properties of the composites were mostly determined by the amount of CNTs, and not by the use of directly melt mixed CNTs or the use of the masterbatch. In contrast, the electrical resistivity of the composites was dependent on the manner in which the CNTs were added to the matrix polymer. When there was increased interfacial adhesion between the components, as for PS and the CNTs, the use of directly melt mixed CNTs gave better resistivity results. Without strong interactions between the CNTs and the matrix, as with PMMA and CNTs, the use of a tailored masterbatch had a significant effect on properties of the final composites. The molecular weight and viscosity of masterbatches can be varied and when the PMMA-masterbatch had optimized viscosity with respect to the PMMA matrix, electrical resistivity of the final composites decreased noticeably.

  20. Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation

    NARCIS (Netherlands)

    Porada, S.; Hamelers, H.V.M.; Bryjak, M.; Presser, V.; Biesheuvel, P.M.; Weingarth, D.

    2014-01-01

    Capacitive technologies, such as capacitive deionization and energy harvesting based on mixing energy (“capmix” and “CO2 energy”), are characterized by intermittent operation: phases of ion electrosorption from the water are followed by system regeneration. From a system application point of view,

  1. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin; Xue, Ming; Song, Qingshan; Chen, Siru; Pan, Ying; Qiu, Shilun

    2014-01-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, b

  2. Black carbon physical properties and mixing state in the European megacity Paris

    Directory of Open Access Journals (Sweden)

    M. Laborde

    2013-06-01

    Full Text Available Aerosol hygroscopicity and refractory black carbon (rBC properties were characterised during wintertime at a suburban site in Paris, one of the biggest European cities. Hygroscopic growth factor (GF frequency distributions, characterised by distinct modes of more-hygroscopic background aerosol and non- or slightly hygroscopic aerosol of local (or regional origin, revealed an increase of the relative contribution of the local sources compared to the background aerosol with decreasing particle size. BC-containing particles in Paris were mainly originating from fresh traffic emissions, whereas biomass burning only gave a minor contribution. The mass size distribution of the rBC cores peaked on average at an rBC core mass equivalent diameter of DMEV ~ 150 nm. The BC-containing particles were moderately coated (coating thickness Δcoat ~ 33 nm on average for rBC cores with DMEV = 180–280 nm and an average mass absorption coefficient (MAC of ~ 8.6 m2 g−1 at the wavelength λ = 880 nm was observed. Different time periods were selected to investigate the properties of BC-containing particles as a function of source and air mass type. The traffic emissions were found to be non-hygroscopic (GF ≈ 1.0, and essentially all particles with a dry mobility diameter (D0 larger than D0 = 110 nm contained an rBC core. rBC from traffic emissions was further observed to be uncoated within experimental uncertainty (Δcoat ~ 2 nm ± 10 nm, to have the smallest BC core sizes (maximum of the rBC core mass size distribution at DMEV ~ 100 nm and to have the smallest MAC (~ 7.3 m2g−1 at λ = 880 nm. The biomass burning aerosol was slightly more hygroscopic than the traffic emissions (with a distinct slightly-hygroscopic mode peaking at GF ≈ 1.1–1.2. Furthermore, only a minor fraction (≤ 10% of the slightly-hygroscopic particles with 1.1 ≤ GF ≤ 1.2 (and D0 = 265 nm contained a detectable rBC core. The BC-containing particles from biomass burning were

  3. REE in the Griqualand-West carbonates - evidence for seawater/fresh water mixing?

    International Nuclear Information System (INIS)

    Danielson, A.

    1990-01-01

    The investigated sample material is derived from the carbonate buildup of the Transvaal Supergoup in an area between Schmitsdrift and Griquatown and Danielskuil and Douglas. Out of the stratigraphic sequence samples from seven formations have been analyzed. The studied material represents a wide range of environmental settings, from platform margin up to intertidal conditions. Various stages of dolomitization are present. 1 ref., 1 fig

  4. Factors influencing organic-horizon carbon pools in mixed-species stands of central Maine, USA

    Science.gov (United States)

    Joshua J. Puhlick; Shawn Fraver; Ivan J. Fernandez; Aaron R. Weiskittel; Laura S. Kenefic; Randy Kolka; Marie-Cecile Gruselle

    2016-01-01

    The overall goal of this study was to evaluate the correlation of multiple abiotic and biotic factors with organic-horizon (O-horizon) carbon (C) content on the Penobscot Experimental Forest in central Maine, USA. O-horizon samples were collected and their associated depths were recorded from stands managed with a range of silvicultural and harvesting treatments (i.e...

  5. Energy footprint and carbon emission reduction using off-the-grid solar-powered mixing for lagoon treatment.

    Science.gov (United States)

    Jiang, Yuyuan; Bebee, Brian; Mendoza, Alvaro; Robinson, Alice K; Zhang, Xiaying; Rosso, Diego

    2018-01-01

    Mixing is the driver for the energy footprint of water resource recovery in lagoons. With the availability of solar-powered equipment, one potential measure to decrease the environmental impacts of treatment is to transition to an off-the-grid treatment. We studied the comparative scenarios of an existing grid-powered mixer and a solar-powered mixer. Testing was conducted to monitor the water quality, and to guarantee that the effluent concentrations were maintained equally between the two scenarios. Meanwhile, the energy consumption was recorded with the electrical energy monitor by the wastewater treatment utility, and the carbon emission changes were calculated using the emission intensity of the power utility. The results show that after the replacement, both energy usage and energy costs were significantly reduced, with the energy usage having decreased by 70% and its cost by 47%. Additionally, carbon-equivalent emission from electricity importation dropped by 64%, with an effect on the overall carbon emissions (i.e., including all other contributions from the process) decreasing from 3.8% to 1.5%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Carbon dioxide selective mixed matrix composite membrane containing ZIF-7 nano-fillers

    KAUST Repository

    Li, Tao

    2013-01-01

    Mixed matrix materials made from selective inorganic fillers and polymers are very attractive for the manufacturing of gas separation membranes. But only few of these materials could be manufactured into high-performance asymmetric or composite membranes. We report here the first mixed matrix composite membrane made of commercially available poly (amide-b-ethylene oxide) (Pebax®1657, Arkema) mixed with the nano-sized zeolitic imidazole framework ZIF-7. This hybrid material has been successfully deposited as a thin layer (less than 1μm) on a porous polyacrylonitrile (PAN) support. An intermediate gutter layer of PTMSP was applied to serve as a flat and smooth surface for coating to avoid polymer penetration into the porous support. Key features of this work are the preparation and use of ultra-small ZIF-7 nano-particles (around 30-35nm) and the membrane processability of Pebax®1657. SEM pictures show that excellent adhesion and almost ideal morphology between the two phases has been obtained simply by mixing the as-synthesized ZIF-7 suspension into the Pebax®1657 dope, and no voids or clusters can be observed. The performance of the composite membrane is characterized by single gas permeation measurement of CO2, N2 and CH4. Both, permeability (PCO2 up to 145barrer) and gas selectivity (CO2/N2 up to 97 and CO2/CH4 up to 30) can be increased at low ZIF- loading. The CO2/CH4 selectivity can be further increased to 44 with the filler loading of 34wt%, but the permeability is reduced compared to the pure Pebax®1657 membrane. Polymer chain rigidification at high filler loading is supposed to be a reason for the reduced permeability. The composite membranes prepared in this work show better performance in terms of permeance and selectivity when compared with asymmetric mixed matrix membranes described in the recent literature. Overall, the ZIF 7/Pebax mixed matrix membranes show a high performance for CO2 separation from methane and other gas streams. They are easy to

  7. Separation of cannabinoids on three different mixed-mode columns containing carbon/nanodiamond/amine-polymer superficially porous particles.

    Science.gov (United States)

    Hung, Chuan-Hsi; Zukowski, Janusz; Jensen, David S; Miles, Andrew J; Sulak, Clayton; Dadson, Andrew E; Linford, Matthew R

    2015-09-01

    Three mixed-mode high-performance liquid chromatography columns packed with superficially porous carbon/nanodiamond/amine-polymer particles were used to separate mixtures of cannabinoids. Columns evaluated included: (i) reversed phase (C18 ), weak anion exchange, 4.6 × 33 mm, 3.6 μm, and 4.6 × 100 mm, 3.6 μm, (ii) reversed phase, strong anion exchange (quaternary amine), 4.6×33 mm, 3.6 μm, and (iii) hydrophilic interaction liquid chromatography, 4.6 × 150 mm, 3.6 μm. Different selectivities were achieved under various mobile phase and stationary phase conditions. Efficiencies and peak capacities were as high as 54 000 N/m and 56, respectively. The reversed phase mixed-mode column (C18 ) retained tetrahydrocannabinolic acid strongly under acidic conditions and weakly under basic conditions. Tetrahydrocannabinolic acid was retained strongly on the reversed phase, strong anion exchange mixed-mode column under basic polar organic mobile phase conditions. The hydrophilic interaction liquid chromatography column retained polar cannabinoids better than the (more) neutral ones under basic conditions. A longer reversed phase (C18 ) mixed-mode column (4.6 × 100 mm) showed better resolution for analytes (and a contaminant) than a shorter column. Fast separations were achieved in less than 5 min and sometimes 2 min. A real world sample (bubble hash extract) was also analyzed by gradient elution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Forecasting carbon dioxide emissions based on a hybrid of mixed data sampling regression model and back propagation neural network in the USA.

    Science.gov (United States)

    Zhao, Xin; Han, Meng; Ding, Lili; Calin, Adrian Cantemir

    2018-01-01

    The accurate forecast of carbon dioxide emissions is critical for policy makers to take proper measures to establish a low carbon society. This paper discusses a hybrid of the mixed data sampling (MIDAS) regression model and BP (back propagation) neural network (MIDAS-BP model) to forecast carbon dioxide emissions. Such analysis uses mixed frequency data to study the effects of quarterly economic growth on annual carbon dioxide emissions. The forecasting ability of MIDAS-BP is remarkably better than MIDAS, ordinary least square (OLS), polynomial distributed lags (PDL), autoregressive distributed lags (ADL), and auto-regressive moving average (ARMA) models. The MIDAS-BP model is suitable for forecasting carbon dioxide emissions for both the short and longer term. This research is expected to influence the methodology for forecasting carbon dioxide emissions by improving the forecast accuracy. Empirical results show that economic growth has both negative and positive effects on carbon dioxide emissions that last 15 quarters. Carbon dioxide emissions are also affected by their own change within 3 years. Therefore, there is a need for policy makers to explore an alternative way to develop the economy, especially applying new energy policies to establish a low carbon society.

  9. Deposition of titanium carbide films from mixed carbon and titanium plasma streams

    International Nuclear Information System (INIS)

    Delplancke-Ogletree, M.; Monteiro, O.R.

    1997-01-01

    Dual source metal plasma immersion ion implantation and deposition was used to deposit Ti x C y films over a wide range of Ti:C composition. This technique is well adapted for this purpose and allows one to tailor the microstructure and properties of the films. We investigated the variation of the composition, bonding states, and structure as functions of the deposition conditions. Excess carbon and contamination oxygen are incorporated in the TiC lattice interstitially and substitutionally, respectively. The wear mechanism of a stoichiometric TiC film was investigated and compared to that of a diamondlike carbon film. TiC fails by wear and microcrack propagation. copyright 1997 American Vacuum Society

  10. Stirring Up the Biological Pump: Vertical Mixing and Carbon Export in the Southern Ocean

    Science.gov (United States)

    Stukel, Michael R.; Ducklow, Hugh W.

    2017-09-01

    The biological carbon pump (BCP) transports organic carbon from the surface to the ocean's interior via sinking particles, vertically migrating organisms, and passive transport of organic matter by advection and diffusion. While many studies have quantified sinking particles, the magnitude of passive transport remains poorly constrained. In the Southern Ocean weak thermal stratification, strong vertical gradients in particulate organic matter, and weak vertical nitrate gradients suggest that passive transport from the euphotic zone may be particularly important. We compile data from seasonal time series at a coastal site near Palmer Station, annual regional cruises in the Western Antarctic Peninsula (WAP), cruises throughout the broader Southern Ocean, and SOCCOM (Southern Ocean Carbon and Climate Observations and Modeling) autonomous profiling floats to estimate spatial and temporal patterns in vertical gradients of nitrate, particulate nitrogen (PN), and dissolved organic carbon. Under a steady state approximation, the ratio of ∂PN/∂z to ∂NO3-/∂z suggests that passive transport of PN may be responsible for removing 46% (37%-58%) of the nitrate introduced into the surface ocean of the WAP (with dissolved organic matter contributing an additional 3-6%) and for 23% (19%-28%) of the BCP in the broader Southern Ocean. A simple model parameterized with in situ nitrate, PN, and primary production data suggested that passive transport was responsible for 54% of the magnitude of the BCP in the WAP. Our results highlight the potential importance of passive transport (by advection and diffusion) of organic matter in the Southern Ocean but should only be considered indicative of high passive transport (rather than conclusive evidence) due to our steady state assumptions.

  11. Upgrading of glycerol from biodiesel synthesis with dimethyl carbonate on reusable Sr–Al mixed oxide catalysts

    International Nuclear Information System (INIS)

    Algoufi, Y.T.; Akpan, U.G.; Kabir, G.; Asif, M.; Hameed, B.H.

    2017-01-01

    Highlights: • Catalytic transesterification with dimethyl carbonate (DMC) converts glycerol into glycerol carbonate (GLC). • DMC and Sr_x–Al catalysts affect the reaction mechanisms that convert glycerol into GLC. • The morphology and textural structure of Sr_x–Al catalysts perpetuate catalytic activity. • The atomic ratio of Sr/Al has a unique effect on Sr–Al catalytic activity. • Sr_0_._5–Al catalyst exhibits limited leaching after five reaction cycles. - Abstract: The high demand for renewable energy has led to the upsurge of methanol-assisted biodiesel synthesis. Therefore, glycerol as a byproduct entered the waste stream given the oversupply of biodiesel to the market. The dimethyl carbonate (DMC)-assisted transesterification of glycerol on a catalyst has been a popular approach for converting glycerol into valuable glycerol carbonate (GLC). The synthesis of GLC from the DMC-assisted transesterification of glycerol on mixed oxide catalysts (Sr_x–Al) with different Sr/Al ratios was examined in this study. A glycerol conversion of 99.4% and a GLC yield of 100% were achieved in a catalyst with Sr/Al = 0.5 (Sr_0_._5–Al). Both values are higher than those in catalysts synthesized with Sr/Al = 0.25 and 0.75. The Sr_0_._5–Al catalyst withstood five transesterification reaction cycles without a serious deactivation induced by the leaching of active SrO. Therefore, the Sr_0_._5–Al catalyst is suitable for consecutive uses in the DMC-assisted transesterification of glycerol with DMC into GLC.

  12. Stratigraphic framework of sediment-starved sand ridges on a mixed siliciclastic/carbonate inner shelf; west-central Florida

    Science.gov (United States)

    Edwards, J.H.; Harrison, S.E.; Locker, S.D.; Hine, A.C.; Twichell, D.C.

    2003-01-01

    Seismic reflection profiles and vibracores have revealed that an inner shelf, sand-ridge field has developed over the past few thousand years situated on an elevated, broad bedrock terrace. This terrace extends seaward of a major headland associated with the modern barrier-island coastline of west-central Florida. The overall geologic setting is a low-energy, sediment-starved, mixed siliciclastic/carbonate inner continental shelf supporting a thin sedimentary veneer. This veneer is arranged in a series of subparallel, shore-oblique, and to a minor extent, shore-parallel sand ridges. Seven major facies are present beneath the ridges, including a basal Neogene limestone gravel facies and a blue-green clay facies indicative of dominantly authigenic sedimentation. A major sequence boundary separates these older units from Holocene age, organic-rich mud facies (marsh), which grades upward into a muddy sand facies (lagoon or shallow open shelf/seagrass meadows). Cores reveal that the muddy shelf facies is either in sharp contact or grades upward into a shelly sand facies (ravinement or sudden termination of seagrass meadows). The shelly sand facies grades upward to a mixed siliciclastic/carbonate facies, which forms the sand ridges themselves. This mixed siliciclastic/carbonate facies differs from the sediment on the beach and shoreface, suggesting insignificant sediment exchange between the offshore ridges and the modern coastline. Additionally, the lack of early Holocene, pre-ridge facies in the troughs between the ridges suggests that the ridges themselves do not migrate laterally extensively. Radiocarbon dating has indicated that these sand ridges can form relatively quickly (???1.3 ka) on relatively low-energy inner shelves once open-marine conditions are available, and that frequent, high-energy, storm-dominated conditions are not necessarily required. We suggest that the two inner shelf depositional models presented (open-shelf vs. migrating barrier-island) may

  13. The diversification value of nuclear power as part of a utility technology mix when gas and carbon prices are uncertain

    International Nuclear Information System (INIS)

    Roques, Fabien A.; Nuttall, William J.; Newbery, David M.; Neufville, Richard de; Connors, Stephen

    2005-01-01

    Despite recent revived interest, the prospects for new nuclear power investment in liberalized electricity industries without government support do not seem promising. The objective of this paper is twofold. First it aims to identify the specific features of nuclear power technology that makes it an unattractive choice. The second objective is to estimate the value to a utility of a nuclear investment as a hedge against uncertain gas and carbon prices. A stylized 5-plant Real Option utility model shows that while the nuclear option value represents about 18% of the net present value (NPV) of the nuclear plant investment in the case where electricity and gas prices are uncorrelated, it reduces to nearly zero for correlation factors between electricity and gas price greater than 30%. These results suggest that the private diversification incentives in electricity markets might not be aligned with the social value of a diverse fuel-mix at the country level. (Author)

  14. Effect of Graphene Oxide Mixed Epoxy on Mechanical Properties of Carbon Fiber/Acrylonitrile-Butadiene-Styrene Composites.

    Science.gov (United States)

    Wang, Cuicui; Ge, Heyi; Ma, Xiaolong; Liu, Zhifang; Wang, Ting; Zhang, Jingyi

    2018-04-01

    In this study, the watersoluble epoxy resin was prepared via the ring-opening reaction between diethanolamine and epoxy resin. The modified resin mixed with graphene oxide (GO) as a sizing agent was coated onto carbon fiber (CF) and then the GO-CF reinforced acrylonitrile-butadienestyrene (ABS) composites were prepared. The influences of the different contents of GO on CF and CF/ABS composite were explored. The combination among epoxy, GO sheets and maleic anhydride grafted ABS (ABSMA) showed a synergistic effect on improving the properties of GO-CF and GO-CF/ABS composite. The GO-CF had higher single tensile strength than the commercial CF. The maximum ILSS of GO-CF/ABS composite obtained 19.2% improvement as compared with that of the commercial CF/ABS composite. Such multiscale enhancement method and the synergistic reinforced GO-CF/ABS composite show good prospective applications in many industry areas.

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

    Science.gov (United States)

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

    2014-01-01

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

  16. Thermoeconomic Optimization of Cascade Refrigeration System Using Mixed Carbon Dioxide and Hydrocarbons at Low Temperature Circuit

    Directory of Open Access Journals (Sweden)

    Nasruddin Nasruddin

    2016-12-01

    Full Text Available Many applications and industrial processes require very low cooling temperature, such as cold storage in the biomedical field, requiring temperature below -80 °C. However,single-cycle refrigeration systems can only achieve the effective cooling temperature of -40 °C and, also, the performance of the cycle will decrease drastically for cooling temperatures lower than -35°C. Currently, most of cascade refrigeration systems use refrigerants that have ozone depletion potential (ODP and global warming potential (GWP, therefore, in this study, a cascade system is simulated using a mixture of environmentally friendly refrigerants, namely, carbon dioxide and a hydrocarbon (propane, ethane or ethylene as the refrigerant of the low temperature circuit. A thermodynamic analysis is performed to determine the optimal composition of the mixture of carbon dioxide and hydrocarbons in the scope of certain operating parameters. In addition, an economic analysis was also performed to determine the annual cost to be incurred from the cascade refrigeration system. The multi-objective/thermoeconomic optimization points out optimal operating parameter values of the system, to addressing both exergy efficiency and its relation to the costs to be incurred.

  17. Charged Nanowire-Directed Growth of Amorphous Calcium Carbonate Nanosheets in a Mixed Solvent for Biomimetic Composite Films.

    Science.gov (United States)

    Liu, Yangyi; Liu, Lei; Chen, Si-Ming; Chang, Fu-Jia; Mao, Li-Bo; Gao, Huai-Ling; Ma, Tao; Yu, Shu-Hong

    2018-04-19

    Bio-inspired mineralization is an effective way for fabricating complicated inorganic materials, which inspires us to develop new methods to synthesize materials with fascinating properties. In this article, we report that the charged tellurium nanowires (TeNWs) can be used as bio-macromolecule analogues to direct the formation of amorphous calcium carbonate (ACC) nanosheets (ACCNs) in a mixed solvent. The effects of surface charges and the concentration of the TeNWs on the formation of ACCNs have been investigated. Particularly, the produced ACCNs can be functionalized by Fe3O4 nanoparticles to produce magnetic ACC/Fe3O4 hybrid nanosheets, which can be used to construct ACC/Fe3O4 composite films through a self-evaporation process. Moreover, sodium alginate-ACC nanocomposite films with remarkable toughness and good transmittance can also be fabricated by using such ACCNs as nanoscale building blocks. This mineralization approach in a mixed solvent using charged tellurium nanowires as bio-macromolecule analogues provides a new way for the synthesis of ACCNs, which can be used as nanoscale building blocks for fabrication of biomimetic composite films.

  18. Substrate Effect on Carbon/Ceramic Mixed Matrix Membrane Prepared by a Vacuum-Assisted Method for Desalination

    Directory of Open Access Journals (Sweden)

    Yingjun Song

    2018-05-01

    Full Text Available This work investigates the effect of various membrane substrates and coating conditions on the formation of carbon/ceramic mixed matrix membranes for desalination application. The substrates were impregnated with phenolic resin via a vacuum-assisted method followed by carbonization under an inert gas. Substrates with pore sizes of 100 nm required a single impregnation step only, where short vacuum times (<120 s resulted in low quality membranes with defects. For vacuum times of ≥120 s, high quality membranes with homogeneous impregnation were prepared leading to high salt rejection (>90% and high water fluxes (up to 25 L m−2 h−1. The increase in water flux as a function of the vacuum time confirms the vacuum etching effect resulting from the vacuum-assisted method. Substrates with pore sizes of 140 nm required two impregnation steps. These pores were too large for the ceramic inter-particle space to be filled with phenolic resin via a single step. In the second impregnation step, increasing the concentration of the phenolic resin resulted in membranes with lower water fluxes. These results indicate that thicker films were formed by increasing the phenolic resin concentration. In the case of substrates with pores of 600 nm, these pores were too large and inter-particle space filling with phenolic resin was not attained.

  19. Preparation of Multi-walled Carbon Nano tubes/ Natural Rubber Composite by Wet Mixing Method

    International Nuclear Information System (INIS)

    Azira Abdul Aziz; Azira Abdul Aziz; Che Su Mat Saad; Mohamad Rusop Mahmood

    2011-01-01

    Natural rubber/multi-walled carbon nano tubes (Nr/MWCNTs) nanocomposite is formed by incorporating nano tubes in a polymer solution and subsequently evaporating the solvent. Using this technique, nano tubes will be dispersed homogeneously in the NR matrix in an attempt to increase the mechanical properties of these nano composites. Mechanical test results show an increase in the tensile strength for up to 19 times in relation to pure NR. In addition to mechanical testing, the morphology of the MWNTs into NR was studied by Field Emission Scanning Electron Microscopy (FESEM) in order to understand the morphology of the resulting system. Slight shift noted from Raman analyses from each different wt. % of MWCNTs with the NR due to the stress transfer that indicates reinforcement of the nano tubes. (author)

  20. Electrochemical Treatment of Wastewater Containing Mixed Reactive Dyes Using Carbon Nanotube Modified Cathode Electrodes

    Directory of Open Access Journals (Sweden)

    Nader Djafarzadeh

    2016-11-01

    Full Text Available Nowadays, advanced electrochemical oxidation processes are promising methods for the treatment of wastewaters containing organic dyes. One of these methods is the Electro-Fenton (EF technique in which an electrical current is applied to the cathode and anode electrodes to promote electrochemical reactions that generate hydroxyl radicals which mineralize organic pollutants and remove them from wastewater. To carry out the Electro-Fenton process iIn this work, the carbon paper (CP electrode was initially modified with carbon nanotubes (CNT to produce the CP-CNT electrode which was used as the cathode to remove a mixture of organic dyestuff (containing Reactive Blue 69, Reactive Red 195, and Reactive Yellow 84 from wastewaters. Comparison of the two types of cathode electrodes (i.e., CNT and the modified CP-CNT showed that the CP-CNT outperformed the CP electrode. The EF process was employed to treat 500 ml of a mixture of dyes (50 mg/L of each dye containing sodium soulfate and Fe+3 ions. The results revealed that the highest color removal efficiency was achieved when a current of 300 mA was applied for 210 min. COD measurments were used to calculate the effective current and power consumption. It was found that the 300 mA current applied over a period of 210 min yielded the highest effective current and the lowest power consumption. The amount of dyes mineralized by the EF process in the dye solution indicated that 78% of the initial COD had been removed under the above conditions. It may be concluded that the Electro-Fenton process can be successfully used for the treatment of wastewaters containing mixtures of dye pollutants. Cathode electrode type, electrical current, and electrolysis duration were identified as the parameters affecting the process.

  1. Carbonization

    Energy Technology Data Exchange (ETDEWEB)

    Hennebutte, H G; Goutal, E

    1921-07-04

    Materials such as coal, peat, or schist are subjected to a rising temperature in successive stages in apparatus in which the distillation products are withdrawn at each stage. For example in a three-stage process, the acid products of the first or low-temperature stage are fixed in a suitable reagent, the basic products from a second or higher-temperature stage are absorbed in an acid reagent, hydrocarbons being retained by solvents, while the third are subjected to a pyrogenation process carried out in a closed vessel. Wherein the material is subjected in stages to a rising temperature, the gasified products being withdrawn at each stage, and are prevented as far as possible from mixing with the carbonized products.

  2. Tackling Carbon Emission with Nature: Effectiveness of Indigenous Microalgae Mixed Culture

    Directory of Open Access Journals (Sweden)

    Chik M. Nazry

    2016-01-01

    Full Text Available Marine microalgae species was isolated and identified from its native condition of sea water discharge canals at the TNB Janamanjung Sdn Bhd’s coal-fired power station. The species was expected to be a robust one based on the prevalent harsh upstream conditions and processes the survived ones endured. The isolation involves streaking-plating method as well as serial dilution and liquid media culture propagation. Morphological and molecular identification were both carried out before satisfactory identification of Chlorella sp. be made. This species was later mixed with marine Isochrysis sp. with varying volumetric proportions and cultured in five separate air-lift bubbling column photobioreactors, as part of the experiment to determine which optimum volumetric culture ratio is best to fix CO2 from the power plant. Results indicate that a more dominant ratio of Chlorella sp. 75% and Isochrysis sp. 25% by volume provide gives a better growth profile and indicates a better CO2 fixation rates.

  3. Selective conversion of carbon monoxide to hydrogen by anaerobic mixed culture.

    Science.gov (United States)

    Liu, Yafeng; Wan, Jingjing; Han, Sheng; Zhang, Shicheng; Luo, Gang

    2016-02-01

    A new method for the conversion of CO to H2 was developed by anaerobic mixed culture in the current study. Higher CO consumption rate was obtained by anaerobic granular sludge (AGS) compared to waste activated sludge (WAS) at 55 °C and pH 7.5. However, H2 was the intermediate and CH4 was the final product. Fermentation at pH 5.5 by AGS inhibited CH4 production, while the lower CO consumption rate (50% of that at pH 7.5) and the production of acetate were found. Fermentation at pH 7.5 with the addition of chloroform achieved efficient and selective conversion of CO to H2. Stable and efficient H2 production was achieved in a continuous reactor inoculated with AGS, and gas recirculation was crucial to increase the CO conversion efficiency. Microbial community analysis showed that high abundance (44%) of unclassified sequences and low relative abundance (1%) of known CO-utilizing bacteria Desulfotomaculum were enriched in the reactor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Impact of Sundarban mangrove biosphere on the carbon dioxide and methane mixing ratios at the NE Coast of Bay of Bengal, India

    International Nuclear Information System (INIS)

    Mukhopadhyay, S.K.; Biswas, H.; De, T.K.; Jana, T.K.; Sen, B.K.; Sen, S.

    2002-01-01

    Diurnal and seasonal variations in carbon dioxide and methane fluxes between Sundarban biosphere and atmosphere were measured using micrometeorological method during 1998-2000. Study of the diurnal variation of micrometeorological conditions in the atmosphere was found to be necessary to determine the duration of neutral stability when flux estimation was reliable. Neutral stability of the atmosphere occurred in the limited micrometeorological conditions, when friction velocity ranged between 0.360 and 0.383ms -1 . The value of drag coefficient (1.62-20.6) x 10 3 obtained at variable wind speed could be deemed specific for this particular surface. 58.2% drop of carbon dioxide and 63.4% drop of methane in the atmosphere at 1m height were observed during day time, between dawn and early evening. Diurnal variations in methane and carbon dioxide mixing ratios showed a positive correlation with Richardson's number (Ri). This environment acted as a net source for carbon dioxide and methane. The mixing ratios of methane were found to vary between 1.42 and 2.07ppmv, and that of carbon dioxide, between 324.3 and 528.7ppmv during the study period. The biosphere-atmosphere flux of carbon dioxide ranged between - 3.29 and 34.4mgm -2 s -1 , and that of methane, between - 4.53 and 8.88μgm -2 s -1 . The overall annual estimate of carbon dioxide and methane fluxes from this ecosystem to atmosphere were estimated to be 694Tgyr -1 and 184Ggyr -1 , respectively. Considerable variations in mixing ratios of carbon dioxide and methane at the NE coast of Bay of Bengal were observed due to the seasonal variations of their fluxes from the biosphere to the atmosphere. The composition was inferred by fitting model prediction to measurements. (Author)

  5. Transformation of carbon tetrachloride and chloroform by trichloroethene respiring anaerobic mixed cultures and supernatant.

    Science.gov (United States)

    Vickstrom, Kyle E; Azizian, Mohammad F; Semprini, Lewis

    2017-09-01

    Carbon tetrachloride (CT) and chloroform (CF) were transformed in batch reactor experiments conducted with anaerobic dechlorinating cultures and supernatant (ADC + S) harvested from continuous flow reactors. The Evanite (EV) and Victoria/Stanford (VS) cultures, capable of respiring trichloroethene (TCE), 1,2-cis-dichloroethene (cDCE), and vinyl chloride (VC) to ethene (ETH), were grown in continuous flow reactors receiving an influent feed of saturated TCE (10 mM; 60 mEq) and formate (45 mM; 90 mEq) but no CT or CF. Cells and supernatant were harvested from the chemostats and inoculated into batch reactors at the onset of each experiment. CT transformation was complete following first order kinetics with CF, DCM and CS 2 as the measurable transformation products, representing 20-40% of the original mass of CT, with CO 2 likely the unknown transformation product. CF was transformed to DCM and likely CO 2 at an order of magnitude rate lower than CT, while DCM was not further transformed. An analytical first order model including multiple key reactions effectively simulated CT transformation, product formation and transformation, and provided reasonable estimates of transformation rate coefficients. Biotic and abiotic treatments indicated that CT was mainly transformed via abiotic processes. However, the presence of live cells was associated with the transformation of CF to DCM. In biotic tests both TCE and CT were simultaneously transformed, with TCE transformed to ETH and approximately 15-53% less CF formed via CT transformation. A 14-day exposure to CF (CF max  = 1.4 μM) reduced all rates of chlorinated ethene respiration by a factor of 10 or greater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Meteorological controls on the diurnal variability of carbon monoxide mixing ratio at a mountaintop monitoring site in the Appalachian Mountains

    Directory of Open Access Journals (Sweden)

    Temple R. Lee

    2015-05-01

    Full Text Available The variability of trace gases such as carbon monoxide (CO at surface monitoring stations is affected by meteorological forcings that are particularly complicated over mountainous terrain. A detailed understanding of the impact of meteorological forcings on trace gas variability is challenging, but is vital to distinguish trace gas measurements affected by local pollutant sources from measurements representative of background mixing ratios. In the present study, we investigate the meteorological and CO characteristics at Pinnacles (38.61 N, 78.35 W, 1017 m above mean sea level, a mountaintop monitoring site in northwestern Virginia, USA, in the Appalachian Mountains, from 2009 to 2012, and focus on understanding the dominant meteorological forcings affecting the CO variability on diurnal timescales. The annual mean diurnal CO cycle shows a minimum in the morning between 0700 and 0900 LST and a maximum in the late afternoon between 1600 and 2000 LST, with a mean (median daily CO amplitude of 39.2±23.7 ppb (33.2 ppb. CO amplitudes show large day-to-day variability. The largest CO amplitudes, in which CO mixing ratios can change >100 ppb in <3 h, occur in the presence of synoptic disturbances. Under fair weather conditions, local- to regional-scale transport processes are found to be more important drivers of the diurnal CO variability. On fair weather days with northwesterly winds, boundary layer dilution causes a daytime CO decrease, resembling the variability observed atop tall towers in flat terrain. Fair weather days with a wind shift from the northwest to the south are characterised by an afternoon CO increase and resemble the variability observed at mountaintops influenced by the vertical transport of polluted air from adjacent valleys.

  7. Predicting mixed-gas adsorption equilibria on activated carbon for precombustion CO2 capture.

    Science.gov (United States)

    García, S; Pis, J J; Rubiera, F; Pevida, C

    2013-05-21

    We present experimentally measured adsorption isotherms of CO2, H2, and N2 on a phenol-formaldehyde resin-based activated carbon, which had been previously synthesized for the separation of CO2 in a precombustion capture process. The single component adsorption isotherms were measured in a magnetic suspension balance at three different temperatures (298, 318, and 338 K) and over a large range of pressures (from 0 to 3000-4000 kPa). These values cover the temperature and pressure conditions likely to be found in a precombustion capture scenario, where CO2 needs to be separated from a CO2/H2/N2 gas stream at high pressure (~1000-1500 kPa) and with a high CO2 concentration (~20-40 vol %). Data on the pure component isotherms were correlated using the Langmuir, Sips, and dual-site Langmuir (DSL) models, i.e., a two-, three-, and four-parameter model, respectively. By using the pure component isotherm fitting parameters, adsorption equilibrium was then predicted for multicomponent gas mixtures by the extended models. The DSL model was formulated considering the energetic site-matching concept, recently addressed in the literature. Experimental gas-mixture adsorption equilibrium data were calculated from breakthrough experiments conducted in a lab-scale fixed-bed reactor and compared with the predictions from the models. Breakthrough experiments were carried out at a temperature of 318 K and five different pressures (300, 500, 1000, 1500, and 2000 kPa) where two different CO2/H2/N2 gas mixtures were used as the feed gas in the adsorption step. The DSL model was found to be the one that most accurately predicted the CO2 adsorption equilibrium in the multicomponent mixture. The results presented in this work highlight the importance of performing experimental measurements of mixture adsorption equilibria, as they are of utmost importance to discriminate between models and to correctly select the one that most closely reflects the actual process.

  8. Effect of regional grid mix, driving patterns and climate on the comparative carbon footprint of gasoline and plug-in electric vehicles in the United States

    Science.gov (United States)

    Yuksel, Tugce; Tamayao, Mili-Ann M.; Hendrickson, Chris; Azevedo, Inês M. L.; Michalek, Jeremy J.

    2016-04-01

    We compare life cycle greenhouse gas (GHG) emissions from several light-duty passenger gasoline and plug-in electric vehicles (PEVs) across US counties by accounting for regional differences due to marginal grid mix, ambient temperature, patterns of vehicle miles traveled (VMT), and driving conditions (city versus highway). We find that PEVs can have larger or smaller carbon footprints than gasoline vehicles, depending on these regional factors and the specific vehicle models being compared. The Nissan Leaf battery electric vehicle has a smaller carbon footprint than the most efficient gasoline vehicle (the Toyota Prius) in the urban counties of California, Texas and Florida, whereas the Prius has a smaller carbon footprint in the Midwest and the South. The Leaf is lower emitting than the Mazda 3 conventional gasoline vehicle in most urban counties, but the Mazda 3 is lower emitting in rural Midwest counties. The Chevrolet Volt plug-in hybrid electric vehicle has a larger carbon footprint than the Prius throughout the continental US, though the Volt has a smaller carbon footprint than the Mazda 3 in many urban counties. Regional grid mix, temperature, driving conditions, and vehicle model all have substantial implications for identifying which technology has the lowest carbon footprint, whereas regional patterns of VMT have a much smaller effect. Given the variation in relative GHG implications, it is unlikely that blunt policy instruments that favor specific technology categories can ensure emission reductions universally.

  9. Effect of regional grid mix, driving patterns and climate on the comparative carbon footprint of gasoline and plug-in electric vehicles in the United States

    International Nuclear Information System (INIS)

    Yuksel, Tugce; Michalek, Jeremy J; Tamayao, Mili-Ann M; Hendrickson, Chris; Azevedo, Inês M L

    2016-01-01

    We compare life cycle greenhouse gas (GHG) emissions from several light-duty passenger gasoline and plug-in electric vehicles (PEVs) across US counties by accounting for regional differences due to marginal grid mix, ambient temperature, patterns of vehicle miles traveled (VMT), and driving conditions (city versus highway). We find that PEVs can have larger or smaller carbon footprints than gasoline vehicles, depending on these regional factors and the specific vehicle models being compared. The Nissan Leaf battery electric vehicle has a smaller carbon footprint than the most efficient gasoline vehicle (the Toyota Prius) in the urban counties of California, Texas and Florida, whereas the Prius has a smaller carbon footprint in the Midwest and the South. The Leaf is lower emitting than the Mazda 3 conventional gasoline vehicle in most urban counties, but the Mazda 3 is lower emitting in rural Midwest counties. The Chevrolet Volt plug-in hybrid electric vehicle has a larger carbon footprint than the Prius throughout the continental US, though the Volt has a smaller carbon footprint than the Mazda 3 in many urban counties. Regional grid mix, temperature, driving conditions, and vehicle model all have substantial implications for identifying which technology has the lowest carbon footprint, whereas regional patterns of VMT have a much smaller effect. Given the variation in relative GHG implications, it is unlikely that blunt policy instruments that favor specific technology categories can ensure emission reductions universally. (letter)

  10. The carbon balance of reducing wildfire risk and restoring process: an analysis of 10-year post-treatment carbon dynamics in a mixed-conifer forest

    Science.gov (United States)

    Morgan L. Wiechmann; Matthew D. Hurteau; Malcolm P. North; George W. Koch; Lucie Jerabkova

    2015-01-01

    Forests sequester carbon from the atmosphere, helping mitigate climate change. In fire-prone forests, burn events result in direct and indirect emissions of carbon. High fire-induced tree mortality can cause a transition from a carbon sink to source, but thinning and prescribed burning can reduce fire severity and carbon loss when wildfire occurs. However, treatment...

  11. Study of the Bioremediation of Atrazine under Variable Carbon and Nitrogen Sources by Mixed Bacterial Consortium Isolated from Corn Field Soil in Fars Province of Iran

    Science.gov (United States)

    Nasseri, Simin; Hashemi, Hassan

    2013-01-01

    Atrazine herbicide that is widely used in corn production is frequently detected in water resources. The main objectives of this research were focused on assessing the effects of carbon and nitrogen sources on atrazine biodegradation by mixed bacterial consortium and by evaluating the feasibility of using mixed bacterial consortium in soil culture. Shiraz corn field soil with a long history of atrazine application has been explored for their potential of atrazine biodegradation. The influence of different carbon compounds and the effect of nitrogen sources and a different pH (5.5–8.5) on atrazine removal efficiency by mixed bacterial consortium in liquid culture were investigated. Sodium citrate and sucrose had the highest atrazine biodegradation rate (87.22%) among different carbon sources. Atrazine biodegradation rate decreased more quickly by the addition of urea (26.76%) compared to ammonium nitrate. Based on the data obtained in this study, pH of 7.0 is optimum for atrazine biodegradation. After 30 days of incubation, the percent of atrazine reduction rates were significantly enhanced in the inoculated soils (60.5%) as compared to uninoculated control soils (12%) at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with mixed bacterial consortium may enhance the rate of atrazine degradation in a highly polluted soil. PMID:23533452

  12. Study of the Bioremediation of Atrazine under Variable Carbon and Nitrogen Sources by Mixed Bacterial Consortium Isolated from Corn Field Soil in Fars Province of Iran

    Directory of Open Access Journals (Sweden)

    Mansooreh Dehghani

    2013-01-01

    Full Text Available Atrazine herbicide that is widely used in corn production is frequently detected in water resources. The main objectives of this research were focused on assessing the effects of carbon and nitrogen sources on atrazine biodegradation by mixed bacterial consortium and by evaluating the feasibility of using mixed bacterial consortium in soil culture. Shiraz corn field soil with a long history of atrazine application has been explored for their potential of atrazine biodegradation. The influence of different carbon compounds and the effect of nitrogen sources and a different pH (5.5–8.5 on atrazine removal efficiency by mixed bacterial consortium in liquid culture were investigated. Sodium citrate and sucrose had the highest atrazine biodegradation rate (87.22% among different carbon sources. Atrazine biodegradation rate decreased more quickly by the addition of urea (26.76% compared to ammonium nitrate. Based on the data obtained in this study, pH of 7.0 is optimum for atrazine biodegradation. After 30 days of incubation, the percent of atrazine reduction rates were significantly enhanced in the inoculated soils (60.5% as compared to uninoculated control soils (12% at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with mixed bacterial consortium may enhance the rate of atrazine degradation in a highly polluted soil.

  13. Electrochemical performance of mixed crystallographic phase nanotubes and nanosheets of titania and titania-carbon/silver composites for lithium-ion batteries

    International Nuclear Information System (INIS)

    Das, Shyamal K.; Bhattacharyya, Aninda J.

    2011-01-01

    Highlights: → Carbon wired TiO 2 nanotubes as anode for lithium ion batteries. → Mixed phase nanotubes show higher energy and power density than titania nanosheets. → Lithium storage and phase stabilization influenced by morphology of carbon coating. - Abstract: The role of homogeneity in ex situ grown conductive coatings and dimensionality in the lithium storage properties of TiO 2 is discussed here. TiO 2 nanotube and nanosheet comprising of mixed crystallographic phases of anatase and TiO 2 (B) have been synthesized by an optimized hydrothermal method. Surface modifications of TiO 2 nanotube are realized via coating the nanotube with Ag nanoparticles and amorphous carbon. The first discharge cycle capacity (at current rate = 10 mA g -1 ) for TiO 2 nanotube and nanosheet were 355 mAh g -1 and 225 mAh g -1 , respectively. The conductive surface coating stabilized the titania crystallographic structure during lithium insertion-deinsertion processes via reduction in the accessibility of lithium ions to the trapping sites. The irreversible capacity is beneficially minimized from 110 mAh g -1 for TiO 2 nanotubes to 96 mAh g -1 and 57 mAh g -1 respectively for Ag and carbon modified TiO 2 nanotubes. The homogeneously coated amorphous carbon over TiO 2 renders better lithium battery performance than randomly distributed Ag nanoparticles coated TiO 2 due to efficient hopping of electrons.

  14. Carbon nanotube-like materials in the exhaust from a diesel engine using gas oil/ethanol mixing fuel with catalysts and sulfur.

    Science.gov (United States)

    Suzuki, Shunsuke; Mori, Shinsuke

    2017-08-01

    Particulate matter from a diesel engine, including soot and carbon nanomaterials, was collected on a sampling holder and the structure of the materials was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). As a result of employing gas oil/ethanol mixing fuel with sulfur and ferrocene/molybdenum as catalyst sources, formation of carbon nanotubes (CNT)-like materials in addition to soot was observed in the exhaust gas from a diesel engine. It was revealed that CNT-like materials were included among soot in our system only when the following three conditions were satisfied simultaneously: high ethanol fraction in fuel, high sulfur loading, and presence of catalyst sources in fuel. This study confirmed that if at least one of these three conditions was not satisfied, CNT-like materials were not observed in the exhaust from a diesel engine. These experimental results shown in this work provide insights into understanding CNT-like material formation mechanism in a diesel engine. Recent papers reported that carbon nanotube-like materials were included in the exhaust gas from engines, but conditions for carbon nanotube-like material formation have not been well studied. This work provides the required conditions for carbon nanotube-like material growth in a diesel engine, and this will be helpful for understanding the carbon nanotube-like material formation mechanism and taking countermeasures to preventing carbon nanotube-like material formation in a diesel engine.

  15. The impacts of policy mix for resolving overcapacity in heavy chemical industry and operating national carbon emission trading market in China

    International Nuclear Information System (INIS)

    Li, Wei; Lu, Can; Ding, Yi; Zhang, Yan-Wu

    2017-01-01

    Highlights: •A STIRPAT embed dynamic CGE model is utilized to evaluate the whole impact. •Economy and trade increased slightly under scenario shock. •Global carbon emission reduction rate ranges from 3.33% to 7.46%. •Carbon emission peaks in 2022, 2024, 2026 beyond simulating scenarios. •Energy intensity decreases 19.58–23.71% upon 2020 in contrast with 2015. -- Abstract: In place to reduce greenhouse gas emission efficiently and accomplish carbon emission peak destination ahead of 2030, a variety of policy-based interventions grounded in optimizing energy structure and boosting emission mitigation have been put forward to target carbon-and resource-intensive enterprises across China. Both defusing overcapacity in heavy chemical industry and constructing national carbon trading market are recently attached with a stronger significant importance. A STIRPAT (Stochastic Impacts by Regression on Population, Affluence, and Technology) embed dynamic CGE (computable general equilibrium) model is applied in this study to evaluate the simulation effects focusing on China’s economy, energy, and household lifestyle. We devise nine scenarios in terms of the two aforementioned mitigation strategies. The results indicate that, the optimal policy mix, balancing economic improvement, energy mix readjustment, and emission reduction to the maximize value, is founded to be declining the proportion of heavy chemical industry capacity with an annual average level of 3%, 1%, 1%, stipulating carbon price in 5.8 dollar/ton, 11.6 dollar/ton, 14.5 dollar/ton, and distributing annual carbon allowance as 3.5 billion ton, 7 billion ton, 9 billion ton during 2017–2020, 2021–2025, and 2026–2030 respectively.

  16. [Dynamics of total organic carbon (TOC) in hydrological processes in coniferous and broad-leaved mixed forest of Dinghushan].

    Science.gov (United States)

    Yin, Guangcai; Zhou, Guoyi; Zhang, Deqiang; Wang, Xu; Chu, Guowei; Liu, Yan

    2005-09-01

    The total flux and concentration of total organic carbon (TOC) in hydrological processes in coniferous and broad-leaved mixed forest of Dinghushan were measured from July 2002 to July 2003. The results showed that the TOC input by precipitation was 41.80 kg x hm(-2) x yr(-1), while its output by surface runoff and groundwater (soil solution at 50 cm depth) was 17.54 and 1.80 kg x hm(-2) x yr(-1), respectively. The difference between input and output was 22.46 kg x hm(-2) x yr(-1), indicating that the ecosystem TOC was in positive balance. The monthly variation of TOC flux in hydrological processes was very similar to that in precipitation. The mean TOC concentration in precipitation was 3.64 mg x L(-1), while that in throughfall and stemflow increased 6.10 and 7.39 times after rain passed through the tree canopies and barks. The mean TOC concentration in surface runoff and in soil solution at 25 and 50 cm depths was 12.72, 7.905 and 3.06 mg x L(-1), respectively. The monthly TOC concentration in throughfall and stemflow had a similar changing tendency, showing an increase at the beginning of growth season (March), a decrease after September, and a little increase in December. The TOC concentration in runoff was much higher during high precipitation months. No obvious monthly variation was observed in soil solution TOC concentration (25 and 50 cm below the surface). Stemflow TOC concentration differed greatly between different tree species. The TOC concentration in precipitation, throughfall, and soil solution (25 and 50 cm depths) decreased with increasing precipitation, and no significant relationship existed between the TOC concentrations in stemflow, surface runoff and precipitation. The TOC concentrations in the hydrological processes fluctuated with precipitation intensity, except for that in stemflow and soil solutions.

  17. Self-immobilization of acidogenic mixed consortia on mesoporous material (SBA-15) and activated carbon to enhance fermentative hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, S. Venkata; Mohanakrishna, G.; Sarma, P.N. [Bioengineering and Environmental Centre, Indian Institute of Chemical Technology, Hyderabad 500607 (India); Reddy, S. Sreevardhan; Raju, B. David; Rao, K.S. Rama [Catalysis and Physical Chemistry Division, Indian Institute of Chemical Technology, Hyderabad 500607 (India)

    2008-11-15

    The influence of self-immobilization of enriched acidogenic mixed consortia on fermentative hydrogen (H{sub 2}) production was studied on different supporting materials [SBA-15 (mesoporous) and activated carbon (granular; GAC and powder; PAC)] using chemical wastewater as substrate. Batch fermentation experiments were performed with same substrate at different organic loading rates (OLRs) under acidophilic microenvironment (pH 5.5) and room temperature (28 {+-} 2 C). Experimental data evidenced the effectiveness of attached growth on both the H{sub 2} yields and substrate degradation efficiency, particularly at higher loading rates. Among the three materials evaluated, immobilization on SBA-15 material showed comparatively effective performance in enhancing both H{sub 2} yield and substrate degradation. Suspended growth (SG-control) culture showed inhibition in terms of both H{sub 2} production and substrate degradation especially at applied higher loading rates. Immobilization on SBA-15 resulted in nine times higher H{sub 2} production (7.29 mol/kg COD{sub R}-day at OLR of 0.83 kg COD/m{sup 3}-day) than the lowest yield observed (suspended growth at OLR of 2.55 kg COD/m{sup 3}-day). Maximum substrate degradation rate (SDR) of 0.96 kg COD/m{sup 3}-day (OLR 2.55 kg COD/m{sup 3}-day) was also observed with SBA-15 immobilization, which is 1.62 times higher than the lowest substrate degradation observed with SG-control experiments with the same OLR. Attached growth on GAC and PAC also showed remarkable improvement in the process performance at higher OLRs compared to SG-control. (author)

  18. Water soluble organic carbon in aerosols (PM1, PM2.5, PM10) and various precipitation forms (rain, snow, mixed) over the southern Baltic Sea station.

    Science.gov (United States)

    Witkowska, Agnieszka; Lewandowska, Anita U

    2016-12-15

    In the urbanized coastal zone of the Southern Baltic, complex measurements of water soluble organic carbon (WSOC) were conducted between 2012 and 2015, involving atmospheric precipitation in its various forms (rain, snow, mixed) and PM1, PM2.5 and PM10 aerosols. WSOC constituted about 60% of the organic carbon mass in aerosols of various sizes. The average concentration of WSOC was equal to 2.6μg∙m -3 in PM1, 3.6μg∙m -3 in PM2.5 and 4.4μg∙m -3 in PM10. The lowest concentration of WSOC was noted in summer as a result of effective removal of this compound with rainfall. The highest WSOC concentrations in PM2.5 and PM10 aerosols were measured in spring, which should be associated with developing vegetation on land and in the sea. On the other hand, the highest WSOC concentrations in PM1 occurred in winter at low air temperatures and greatest atmospheric stability, when there were increased carbon emissions from fuel combustion in the communal-utility sector and from transportation. WSOC concentrations in precipitation were determined by its form. Mixed precipitation turned out to be the richest in soluble organic carbon (5.1mg·dm -3 ), while snow contained the least WSOC (1.7mg·dm -3 ). Snow and rain cleaned carbon compounds from the atmosphere more effectively when precipitation lasted longer than 24h, while in the case of mixed precipitation WSOC was removed most effectively within the first 24h. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Transfer-free synthesis of graphene-like atomically thin carbon films on SiC by ion beam mixing technique

    Science.gov (United States)

    Zhang, Rui; Chen, Fenghua; Wang, Jinbin; Fu, Dejun

    2018-03-01

    Here we demonstrate the synthesis of graphene directly on SiC substrates at 900 °C using ion beam mixing technique with energetic carbon cluster ions on Ni/SiC structures. The thickness of 7-8 nm Ni films was evaporated on the SiC substrates, followed by C cluster ion bombarding. Carbon cluster ions C4 were bombarded at 16 keV with the dosage of 4 × 1016 atoms/cm2. After thermal annealing process Ni silicides were formed, whereas C atoms either from the decomposition of the SiC substrates or the implanted contributes to the graphene synthesis by segregating and precipitating process. The limited solubility of carbon atoms in silicides, involving SiC, Ni2Si, Ni5Si2, Ni3Si, resulted in diffusion and precipitation of carbon atoms to form graphene on top of Ni and the interface of Ni/SiC. The ion beam mixing technique provides an attractive production method of a transfer-free graphene growth on SiC and be compatible with current device fabrication.

  20. Chloride pyrometallurgy of uranium ore. 2. Selective extraction of uranium using the mixed gas of chlorine and oxygen in the presence of activated carbon

    International Nuclear Information System (INIS)

    Taki, Tomihiro; Komoto, Shigetoshi; Otomura, Keiichiro; Takenaka, Toshihide; Sato, Nobuaki; Fujino, Takeo.

    1996-01-01

    Selective extraction of uranium from a phosphate ore was studied by using the mixed gas of Cl 2 and O 2 . On heating the ore and carbon mixture in Cl 2 , the volatilized chloride of uranium is accompanied by iron, aluminum, phosphorus and silicon chlorides. The addition of O 2 gas effectively lowered the volatilization ratios of aluminum, phosphorus and silicon. The ratio decreased with increasing oxygen flow rate up to 50 ml/min at 1,223 K (Cl 2 : 100 ml/min, O 2 +N 2 : 400 ml/min). The volatilization ratio of uranium was almost unchanged at 90% up to 50 ml/min O 2 (carbon amount: 15 wt%). The effect of the other parameters, i.e. Cl 2 flow rate, carbon amount, reaction temperature and time was examined. (author)

  1. Contrasting effects of temperature and winter mixing on the seasonal and inter-annual variability of the carbonate system in the Northeast Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    C. Dumousseaud

    2010-05-01

    Full Text Available Future climate change as a result of increasing atmospheric CO2 concentrations is expected to strongly affect the oceans, with shallower winter mixing and consequent reduction in primary production and oceanic carbon drawdown in low and mid-latitudinal oceanic regions. Here we test this hypothesis by examining the effects of cold and warm winters on the carbonate system in the surface waters of the Northeast Atlantic Ocean for the period between 2005 and 2007. Monthly observations were made between the English Channel and the Bay of Biscay using a ship of opportunity program. During the colder winter of 2005/2006, the maximum depth of the mixed layer reached up to 650 m in the Bay of Biscay, whilst during the warmer (by 2.6 ± 0.5 °C winter of 2006/2007 the mixed layer depth reached only 300 m. The inter-annual differences in late winter concentrations of nitrate (2.8 ± 1.1 μmol l−1 and dissolved inorganic carbon (22 ± 6 μmol kg−1, with higher concentrations at the end of the colder winter (2005/2006, led to differences in the dissolved oxygen anomaly and the chlorophyll α-fluorescence data for the subsequent growing season. In contrast to model predictions, the calculated air-sea CO2 fluxes (ranging from +3.7 to −4.8 mmol m−2 d−1 showed an increased oceanic CO2 uptake in the Bay of Biscay following the warmer winter of 2006/2007 associated with wind speed and sea surface temperature differences.

  2. Effect of polymer type on characterization and filtration performances of multi-walled carbon nanotubes (MWCNT)-COOH-based polymeric mixed matrix membranes.

    Science.gov (United States)

    Sengur-Tasdemir, Reyhan; Mokkapati, Venkata R S S; Koseoglu-Imer, Derya Y; Koyuncu, Ismail

    2018-05-01

    Multi-walled carbon nanotubes (MWCNTs) can be used for the fabrication of mixed matrix polymeric membranes that can enhance filtration perfomances of the membranes by modifying membrane surface properties. In this study, detailed characterization and filtration performances of MWCNTs functionalized with COOH group, blended into polymeric flat-sheet membranes were investigated using different polymer types. Morphological characterization was carried out using atomic force microscopy, scanning electron microscopy and contact angle measurements. For filtration performance tests, protein, dextran, E. coli suspension, Xanthan Gum and real activated sludge solutions were used. Experimental data and analyses revealed that Polyethersulfone (PES) + MWCNT-COOH mixed matrix membranes have superior performance abilities compared to other tested membranes.

  3. Optimization of mixing process and effect of multi-walled carbon nanotubes on tensile properties of unsaturated polyester resin in composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Van-Tho; Yum, Young-Jin [University of Ulsan, Ulsan (Korea, Republic of)

    2017-04-15

    Multi-walled carbon nanotubes (MWCNTs) were mixed with Unsaturated polyester resin (UPR) using the stir method at high temperatures. The mixing temperature and hardener ratio were optimized based on compression properties and the exothermic temperature. In the experiment, 60 °C and 1 wt.% of Methyl ethyl ketone peroxide (MEKP) were chosen for the mixing condition and catalyst concentration, respectively. MWCNTs with different weight fractions (0.05, 0.1, 0.2 and 0.3 wt.%) were dispersed to investigate the effect of MWCNTs on tensile properties of the UPR, and it was found that 0.1 wt.% of MWCNTs showed the best performance in this range of fiber weight fraction due to a higher strength (42.14 %), modulus (14.33 %) and fracture strain (37.17 %) than pure UPR. The state of dispersion and arrangement of fibers were examined by a Field emission Scanning electron microscope (FE-SEM) according to fracture surfaces. Similarly, the FE-SEM also showed better results with 0.1 wt.% of MWCNTs mixed in the UPR.

  4. Optimization Forest Thinning Measures for Carbon Budget in a Mixed Pine-Oak Stand of the Qingling Mountains, China: A Case Study

    Directory of Open Access Journals (Sweden)

    Lin Hou

    2016-11-01

    Full Text Available Forest thinning is a silviculture treatment for sustainable forest management. It may promote growth of the remaining individuals by decreasing stand density, reducing competition, and increasing light and nutrient availability to increase carbon sequestration in the forest ecosystem. However, the action also increases carbon loss simultaneously by reducing carbon and other nutrient inputs as well as exacerbating soil CO2 efflux. To achieve a maximum forest carbon budget, the central composite design with two independent variables (thinning intensity and thinning residual removal rate was explored in a natural pine-oak mixed stand in the Qinling Mountains, China. The net primary productivity of living trees was estimated and soil CO2 efflux was stimulated by the Yasso07 model. Based on two years observation, the preliminary results indicated the following. Evidently chemical compounds of the litter of the tree species affected soil CO2 efflux stimulation. The thinning residual removal rate had a larger effect than thinning intensity on the net ecosystem productivity. When the selective thinning intensity and residual removal rate was 12.59% and 66.62% concurrently, the net ecosystem productivity reached its maximum 53.93 t·ha−1·year−1. The lower thinning intensity and higher thinning residual removal rated benefited the net ecosystem productivity.

  5. Tree Stress and Mortality from Emerald Ash Borer Does Not Systematically Alter Short-Term Soil Carbon Flux in a Mixed Northeastern U.S. Forest

    Directory of Open Access Journals (Sweden)

    Jaclyn Hatala Matthes

    2018-01-01

    Full Text Available Invasive insect pests are a common disturbance in temperate forests, but their effects on belowground processes in these ecosystems are poorly understood. This study examined how aboveground disturbance might impact short-term soil carbon flux in a forest impacted by emerald ash borer (Agrilus planipennis Fairmaire in central New Hampshire, USA. We anticipated changes to soil moisture and temperature resulting from tree mortality caused by emerald ash borer, with subsequent effects on rates of soil respiration and methane oxidation. We measured carbon dioxide emissions and methane uptake beneath trees before, during, and after infestation by emerald ash borer. In our study, emerald ash borer damage to nearby trees did not alter soil microclimate nor soil carbon fluxes. While surprising, the lack of change in soil microclimate conditions may have been a result of the sandy, well-drained soil in our study area and the diffuse spatial distribution of canopy ash trees and subsequent canopy light gaps after tree mortality. Overall, our results indicate that short-term changes in soil carbon flux following insect disturbances may be minimal, particularly in forests with well-drained soils and a mixed-species canopy.

  6. Some problems associated with the analysis and interpretation of mixed carbonate and quartz beach sands, illustrated by examples from North-West Ireland

    Science.gov (United States)

    Carter, R. W. G.

    1982-09-01

    Mixes of carbonate and quartz sands, which are commonly encountered in Recent coastal sediments, require careful analysis if they are to be correctly interpreted. Grain-size data fall into multimodal or segmented zig-zag distributions which may require some kind of component separation if they are to be summarised by conventional statistics, and before they can be assigned to a particular hydrodynamic depositional process or environment. Unfortunately, separation techniques are only spasmodically applied, usually without due regard to the consequences. Such artificially filtered or truncated distributions are of little subsequent use. Using a range of samples from two beaches in NW Ireland, where carbonate proportions range from nearly zero to over sixty percent, the interrelationships of the two dominant components were examined. Where only a small carbonate proportion is incorporated into a large quartz one, predictable modifications of the size-curve are apparent. However, the components are more independent if mixtures are near equal. The occurrence of a number of distinctive combinations of simple straight lines and complex zig-zag curves probably reflects the relatively dynamic nature of the carbonate fraction.

  7. The single-particle mixing state and cloud scavenging of black carbon: a case study at a high-altitude mountain site in southern China

    Science.gov (United States)

    Zhang, Guohua; Lin, Qinhao; Peng, Long; Bi, Xinhui; Chen, Duohong; Li, Mei; Li, Lei; Brechtel, Fred J.; Chen, Jianxin; Yan, Weijun; Wang, Xinming; Peng, Ping'an; Sheng, Guoying; Zhou, Zhen

    2017-12-01

    In the present study, a ground-based counterflow virtual impactor (GCVI) was used to sample cloud droplet residual (cloud RES) particles, while a parallel PM2.5 inlet was used to sample cloud-free or cloud interstitial (cloud INT) particles. The mixing state of black carbon (BC)-containing particles and the mass concentrations of BC in the cloud-free, RES and INT particles were investigated using a single-particle aerosol mass spectrometer (SPAMS) and two aethalometers, respectively, at a mountain site (1690 m a. s. l. ) in southern China. The measured BC-containing particles were extensively internally mixed with sulfate and were scavenged into cloud droplets (with number fractions of 0.05-0.45) to a similar (or slightly lower) extent as all the measured particles (0.07-0.6) over the measured size range of 0.1-1.6 µm. The results indicate the preferential activation of larger particles and/or that the production of secondary compositions shifts the BC-containing particles towards larger sizes. BC-containing particles with an abundance of both sulfate and organics were scavenged less than those with sulfate but limited organics, implying the importance of the mixing state on the incorporation of BC-containing particles into cloud droplets. The mass scavenging efficiency of BC with an average of 33 % was similar for different cloud events independent of the air mass. This is the first time that both the mixing state and cloud scavenging of BC in China have been reported. Our results would improve the knowledge on the concentration, mixing state, and cloud scavenging of BC in the free troposphere.

  8. Seasonality of Leaf Carbon Isotopic Composition and Leaf Water Isotopic Enrichment in a Mixed Evergreen Forest in Southern California

    Science.gov (United States)

    Santiago, L. S.; Sickman, J. O.; Goulden, M.; DeVan, C.; Pasquini, S. C.; Pivovaroff, A. L.

    2011-12-01

    Leaf carbon isotopic composition and leaf water isotopic enrichment reflect physiological processes and are important for linking local and regional scale processes to global patterns. We investigated how seasonality affects the isotopic composition of bulk leaf carbon, leaf sugar carbon, and leaf water hydrogen under a Mediterranean climate. Leaf and stem samples were collected monthly from four tree species (Calocedrus decurrens, Pinus lambertiana, Pinus ponderosa, and Quercus chrysolepis) at the James San Jacinto Mountain Reserve in southern California. Mean monthly bulk leaf carbon isotopic composition varied from -34.5 % in P. ponderosa to -24.7 % in P. lambertiana and became more depleted in 13C from the spring to the summer. Mean monthly leaf sugar varied from -29.3 % in P. ponderosa to -21.8 % in P. lambertiana and was enriched in 13C during the winter, spring and autumn, but depleted during the mid-summer. Leaf water hydrogen isotopic composition was 28.4 to 68.8 % more enriched in deuterium than source water and this enrichment was greater as seasonal drought progressed. These data indicate that leaf carbon and leaf water hydrogen isotopic composition provide sensitive measures that connect plant physiological processes to short-term climatic variability.

  9. Inflammability of magnesium and its alloys in carbon dioxide either pure or mixed with water vapour, air or oxygen

    International Nuclear Information System (INIS)

    Baque, P.; Chevilliard, C.; Darras, R.

    1964-01-01

    Whereas low contents of metallic additions have only a small influence on the temperature at which magnesium begins to burn in carbon dioxide, an increase in the specific surface area of the samples is likely to reduce it considerably, the self-heating phenomena being then more pronounced. On the other hand, the exact nature of the surrounding atmosphere is a very important factor; thus the temperature at which ignition begins increases with increasing carbon dioxide pressure, decreases very rapidly when the moisture content of this gas increases up to 3000 v.p.m., and decreases regularly when the partial pressure of air or oxygen increases. (authors) [fr

  10. Carbon molecular sieve membrane from a microporous spirobisindane-based polyimide precursor with enhanced ethylene/ethane mixed-gas selectivity

    KAUST Repository

    Salinas, Octavio

    2017-01-13

    Ethylene is typically produced by steam cracking of various hydrocarbon feedstocks. The gaseous products are then separated in a demethanizer followed by a deethanizer unit and finally sent to a C splitter for the final purification step. Cryogenic distillation of ethylene from ethane is the most energy-intensive unit operation process in the chemical industry. Therefore, the development of more energy-efficient processes for ethylene purification is highly desirable. Membrane-based separation has been proposed as an alternative option for replacement or debottlenecking of C splitters but current polymer membrane materials exhibit insufficient mixed-gas CH/CH selectivity (<7) to be technically and economically attractive. In this work, a highly selective carbon molecular sieve (CMS) membrane derived from a novel spirobisindane-based polyimide of intrinsic microporosity (PIM-6FDA) was developed and characterized. PIM-6FDA showed a single-stage degradation process under an inert nitrogen atmosphere which commenced at ∼480 °C. The CMS formed by pyrolysis at 800 °C had a diffusion/size-sieving-controlled morphology with a mixed-gas (50% CH/50% CH) ethylene/ethane selectivity of 15.6 at 20 bar feed pressure at 35 °C. The mixed-gas ethylene/ethane selectivity is the highest reported value for CMS-type membranes to date.

  11. Ecosystem-Atmosphere Exchange of Carbon, Water and Energy over a Mixed Deciduous Forest in the Midwest

    Energy Technology Data Exchange (ETDEWEB)

    Danilo Dragoni; Hans Peter Schmid; C.S.B. Grimmond; J.C. Randolph; J.R. White

    2012-12-17

    During the project period we continued to conduct long-term (multi-year) measurements, analysis, and modeling of energy and mass exchange in and over a deciduous forest in the Midwestern United States, to enhance the understanding of soil-vegetation-atmosphere exchange of carbon. At the time when this report was prepared, results from nine years of measurements (1998 - 2006) of above canopy CO2 and energy fluxes at the AmeriFlux site in the Morgan-Monroe State Forest, Indiana, USA (see Table 1), were available on the Fluxnet database, and the hourly CO2 fluxes for 2007 are presented here (see Figure 1). The annual sequestration of atmospheric carbon by the forest is determined to be between 240 and 420 g C m-2 a-1 for the first ten years. These estimates are based on eddy covariance measurements above the forest, with a gap-filling scheme based on soil temperature and photosynthetically active radiation. Data gaps result from missing data or measurements that were rejected in qua)lity control (e.g., during calm nights). Complementary measurements of ecological variables (i.e. inventory method), provided an alternative method to quantify net carbon uptake by the forest, partition carbon allocation in each ecosystem components, and reduce uncertainty on annual net ecosystem productivity (NEP). Biometric datasets are available on the Fluxnext database since 1998 (with the exclusion of 2006). Analysis for year 2007 is under completion.

  12. Post-fire management regimes affect carbon sequestration and storage in a Sierra Nevada mixed conifer forest

    Science.gov (United States)

    Elizabeth M. Powers; John D. Marshall; Jianwei Zhang; Liang Wei

    2013-01-01

    Forests mitigate climate change by sequestering CO2 from the atmosphere and accumulating it in biomass storage pools. However, in dry conifer forests, fire occasionally returns large quantities of CO2 to the atmosphere. Both the total amount of carbon stored and its susceptibility to loss may be altered by post-fire land...

  13. Effects of carbon sources on the enrichment of halophilic polyhydroxyalkanoate-storing mixed microbial culture in an aerobic dynamic feeding process

    Science.gov (United States)

    Cui, You-Wei; Zhang, Hong-Yu; Lu, Peng-Fei; Peng, Yong-Zhen

    2016-08-01

    Microbial polyhydroxyalkanoate (PHA) production serves as a substitute for petroleum-based plastics. Enriching mixed microbial cultures (MMCs) with the capacity to store PHA is a key precursor for low-cost PHA production. This study investigated the impact of carbon types on enrichment outcomes. Three MMCs were separately fed by acetate sodium, glucose, and starch as an enriching carbon source, and were exposed to long-term aerobic dynamic feeding (ADF) periods. The PHA production capacity, kinetics and stoichiometry of the enrichments, the PHA composition, and the microbial diversity and community composition were explored to determine carbon and enrichment correlations. After 350-cycle enriching periods under feast-famine (F-F) regimes, the MMCs enriched by acetate sodium and glucose contained a maximum PHA content of 64.7% and 60.5% cell dry weight (CDW). The starch-enriched MMC only had 27.3% CDW of PHA. High-throughput sequencing revealed that non-PHA bacteria survived alongside PHA storing bacteria, even under severe F-F selective pressure. Genus of Pseudomonas and Stappia were the possible PHA accumulating bacteria in acetate-enriched MMC. Genus of Oceanicella, Piscicoccus and Vibrio were found as PHA accumulating bacteria in glucose-enriched MMC. Vibrio genus was the only PHA accumulating bacteria in starch-enriched MMC. The community diversity and composition were regulated by the substrate types.

  14. Mixed bi-material electrodes based on LiMn2O4 and activated carbon for hybrid electrochemical energy storage devices

    International Nuclear Information System (INIS)

    Cericola, Dario; Novak, Petr; Wokaun, Alexander; Koetz, Ruediger

    2011-01-01

    Highlights: → Bi-material electrodes for electrochemical hybrid devices were characterized. → Bi-material electrodes have higher specific charge than capacitor electrodes. → Bi-material electrodes have better rate capability than battery electrodes. → Bi-material systems outperform batteries and capacitors in pulsed applications. - Abstract: The performance of mixed bi-material electrodes composed of the battery material, LiMn 2 O 4 , and the electrochemical capacitor material, activated carbon, for hybrid electrochemical energy storage devices is investigated by galvanostatic charge/discharge and pulsed discharge experiments. Both, a high and a low conductivity lithium-containing electrolyte are used. The specific charge of the bi-material electrode is the linear combination of the specific charges of LiMn 2 O 4 and activated carbon according to the electrode composition at low discharge rates. Thus, the specific charge of the bi-material electrode falls between the specific charge of the activated carbon electrode and the LiMn 2 O 4 battery electrode. The bi-material electrodes have better rate capability than the LiMn 2 O 4 battery electrode. For high current pulsed applications the bi-material electrodes typically outperform both the battery and the capacitor electrode.

  15. An 8-year, high-resolution reanalysis of atmospheric carbon dioxide mixing ratios based on OCO-2 and GOSAT-ACOS retrievals

    Science.gov (United States)

    Weir, B.; Chatterjee, A.; Ott, L. E.; Pawson, S.

    2017-12-01

    This talk presents an overview of results from the GEOS-Carb reanalysis of retrievals of average-column carbon dioxide (XCO2) from the Orbiting Carbon Observatory 2 (OCO-2) and Greenhouse Gases Observing Satellite (GOSAT) satellite missions. The reanalysis is a Level 3 (L3) product: a collection of 3D fields of carbon dioxide (CO2) mixing ratios every 6 hours beginning in April 2009 going until the present on a grid with a 0.5 degree horizontal resolution and 72 vertical levels from the surface to 0.01 hPa. Using an assimilation methodology based on the Goddard Earth Observing System (GEOS) atmospheric data assimilation system (ADAS), the L3 fields are weighted averages of the two satellite retrievals and predictions from the GEOS general circulation model driven by assimilated meteorology from the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2). In places and times where there are a dense number of soundings, the observations dominate the predicted mixing ratios, while the model is used to fill in locations with fewer soundings, e.g., high latitudes and the Amazon. Blending the satellite observations with model predictions has at least two notable benefits. First, it provides a bridge for evaluating the satellite retrievals and their uncertainties against a heterogeneous collection of observations including those from surface sites, towers, aircraft, and soundings from the Total Carbon Column Observing Network (TCCON). Extensive evaluations of the L3 reanalysis clearly demonstrate both the strength and the deficiency of the satellite retrievals. Second, it is possible to estimate variables from the reanalysis without introducing bias due to spatiotemporal variability in sounding coverage. For example, the assimilated product provides robust estimates of the monthly CO2 global growth rate. These monthly growth rate estimates show significant differences from estimates based on in situ observations, which have sparse coverage

  16. A Mixed-Mode (I-II) Fracture Criterion for AS4/8552 Carbon/Epoxy Composite Laminate

    Science.gov (United States)

    Karnati, Sidharth Reddy

    A majority of aerospace structures are subjected to bending and stretching loads that introduce peel and shear stresses between the plies of a composite laminate. These two stress components cause a combination of mode I and II fracture modes in the matrix layer of the composite laminate. The most common failure mode in laminated composites is delamination that affects the structural integrity of composite structures. Damage tolerant designs of structures require two types of materials data: mixed-mode (I-II) delamination fracture toughness that predicts failure and delamination growth rate that predicts the life of the structural component. This research focuses determining mixed-mode (I-II) fracture toughness under a combination of mode I and mode II stress states and then a fracture criterion for AS4/8552 composite laminate, which is widely used in general aviation. The AS4/8552 prepreg was supplied by Hexcel Corporation and autoclave fabricated into a 20-ply unidirectional laminate with an artificial delamination by a Fluorinated Ethylene Propylene (FEP) film at the mid-plane. Standard split beam specimens were prepared and tested in double cantilever beam (DCB) and end notched flexure modes to determine mode I (GIC) and II (GIIC) fracture toughnesses, respectively. The DCB specimens were also tested in a modified mixed-mode bending apparatus at GIIm /GT ratios of 0.18, 0.37, 0.57 and 0.78, where GT is total and GIIm is the mode II component of energy release rates. The measured fracture toughness, GC, was found to follow the locus a power law equation. The equation was validated for the present and literature experimental data.

  17. Effective enhancement of gas separation performance in mixed matrix membranes using core/shell structured multi-walled carbon nanotube/graphene oxide nanoribbons

    Science.gov (United States)

    Xue, Qingzhong; Pan, Xinglong; Li, Xiaofang; Zhang, Jianqiang; Guo, Qikai

    2017-02-01

    Novel core/shell structured multi-walled carbon nanotube/graphene oxide nanoribbons (MWCNT@GONRs) nanohybrids were successfully prepared using a modified chemical longitudinal unzipping method. Subsequently, the MWCNT@GONRs nanohybrids were used as fillers to enhance the gas separation performance of polyimide based mixed matrix membranes (MMMs). It is found that MMMs concurrently exhibited higher gas selectivity and higher gas permeability compared to pristine polyimide. The high gas selectivity could be attributed to the GONRs shell, which provided a selective barrier and large gas adsorbed area, while the high gas permeability resulted from the hollow structured MWCNTs core with smooth internal surface, which acted as a rapid transport channel. MWCNT@GONRs could be promising candidates to improve gas separation performance of MMMs due to the unique microstructures, ease of synthesis and low filling loading.

  18. Ground-based measurement of column-averaged mixing ratios of methane and carbon dioxide in the Sichuan Basin of China by a desktop optical spectrum analyzer

    Science.gov (United States)

    Qin, Xiu-Chun; Nakayama, Tomoki; Matsumi, Yutaka; Kawasaki, Masahiro; Ono, Akiko; Hayashida, Sachiko; Imasu, Ryoichi; Lei, Li-Ping; Murata, Isao; Kuroki, Takahiro; Ohashi, Masafumi

    2018-01-01

    Remote sensing of the atmospheric greenhouse gases, methane (CH4) and carbon dioxide (CO2), contributes to the understanding of global warming and climate change. A portable ground-based instrument consisting of a commercially available desktop optical spectrum analyzer and a small sun tracker has been applied to measure the column densities of atmospheric CH4 and CO2 at Yanting observation station in a mountainous paddy field of the Sichuan Basin from September to November 2013. The column-averaged dry-air molar mixing ratios, XCH4/XCO2, are compared with those retrieved by satellite observations in the Sichuan Basin and by ground-based network observations in the same latitude zone as the Yanting observation station.

  19. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing.

    Science.gov (United States)

    Liapis, Ioannis; Papayianni, Ioanna

    2015-01-01

    Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. The Effect of the Interannual Variability of the OH Sink on the Interannual Variability of the Atmospheric Methane Mixing Ratio and Carbon Stable Isotope Composition

    Science.gov (United States)

    Guillermo Nuñez Ramirez, Tonatiuh; Houweling, Sander; Marshall, Julia; Williams, Jason; Brailsford, Gordon; Schneising, Oliver; Heimann, Martin

    2013-04-01

    The atmospheric hydroxyl radical concentration (OH) varies due to changes in the incoming UV radiation, in the abundance of atmospheric species involved in the production, recycling and destruction of OH molecules and due to climate variability. Variability in carbon monoxide emissions from biomass burning induced by El Niño Southern Oscillation are particularly important. Although the OH sink accounts for the oxidation of approximately 90% of atmospheric CH4, the effect of the variability in the distribution and strength of the OH sink on the interannual variability of atmospheric methane (CH4) mixing ratio and stable carbon isotope composition (δ13C-CH4) has often been ignored. To show this effect we simulated the atmospheric signals of CH4 in a three-dimensional atmospheric transport model (TM3). ERA Interim reanalysis data provided the atmospheric transport and temperature variability from 1990 to 2010. We performed simulations using time dependent OH concentration estimations from an atmospheric chemistry transport model and an atmospheric chemistry climate model. The models assumed a different set of reactions and algorithms which caused a very different strength and distribution of the OH concentration. Methane emissions were based on published bottom-up estimates including inventories, upscaled estimations and modeled fluxes. The simulations also included modeled concentrations of atomic chlorine (Cl) and excited oxygen atoms (O(1D)). The isotopic signal of the sources and the fractionation factors of the sinks were based on literature values, however the isotopic signal from wetlands and enteric fermentation processes followed a linear relationship with a map of C4 plant fraction. The same set of CH4emissions and stratospheric reactants was used in all simulations. Two simulations were done per OH field: one in which the CH4 sources were allowed to vary interannually, and a second where the sources were climatological. The simulated mixing ratios and

  1. Sorption Characteristics of Mixed Molecules of Glutaraldehyde from Water on Mesoporous Acid-Amine Modified Low-Cost Activated Carbon: Mechanism, Isotherm, and Kinetics

    Directory of Open Access Journals (Sweden)

    Mukosha Lloyd

    2015-01-01

    Full Text Available The environmental discharge of inefficiently treated waste solutions of the strong biocide glutaraldehyde (GA from hospitals has potential toxic impact on aquatic organisms. The adsorption characteristics of mixed polarized monomeric and polymeric molecules of GA from water on mesoporous acid-amine modified low-cost activated carbon (AC were investigated. It was found that the adsorption strongly depended on pH and surface chemistry. In acidic pH, the adsorption mechanism was elaborated to involve chemical sorption of mainly hydroxyl GA monomeric molecules on acidic surface groups, while in alkaline pH, the adsorption was elaborated to involve both chemical and physical sorption of GA polymeric forms having mixed functional groups (aldehyde, carboxyl, and hydroxyl on acidic and amine surface groups. The optimum pH of adsorption was about 12 with significant contribution by cooperative adsorption, elucidated in terms of hydrogen bonding and aldol condensation. Freundlich and Dubinin-Radushkevich models were fitted to isotherm data. The adsorption kinetics was dependent on initial concentration and temperature and described by the Elovich model. The adsorption was endothermic, while the intraparticle diffusion model suggested significant contribution by film diffusion. The developed low-cost AC could be used to supplement the GA alkaline deactivation process for efficient removal of residual GA aquatic toxicity.

  2. Transesterification of Jatropha oil with dimethyl carbonate to produce fatty acid methyl ester over reusable Ca–La–Al mixed-oxide catalyst

    International Nuclear Information System (INIS)

    Syamsuddin, Y.; Murat, M.N.; Hameed, B.H.

    2015-01-01

    Highlights: • Transesterification of Jatropha oil over CaO-based catalyst. • Physicochemical properties of the synthesized catalyst. • Best reaction condition for FAME synthesis. • The catalyst showed high activity and stability for transesterification with Jatropha oil. - Abstract: Jatropha oil (JO) was transesterified with dimethyl carbonate (DMC) to produce fatty acid methyl ester (FAME) over synthesized Ca–La–Al mixed-oxide catalyst. The influence of different parameters on transesterification of Jatropha oil was investigated in a batch reactor. These parameters included reaction temperature (110–160 °C), reaction time (30–240 min), DMC-to-oil molar ratio (4:1–18:1) and catalyst loading amount (1–10 wt.%, based on the oil weight). The mixed-oxide catalyst with a molar ratio of 6:2:1 (Ca–La–Al) showed high catalytic activity for FAME synthesis. More than 90% of FAME was obtained under the following reaction conditions: 150 °C, reaction temperature; 180 min, reaction time; 15:1, DMC-to-oil molar ratio; and 7 wt.% amount of catalyst loading. The catalyst also exhibited high stability and could be reused for up to five cycles with less than 5% yield reduction per cycle.

  3. Film fabrication of Fe or Fe3O4 nanoparticles mixed with palmitic acid for vertically aligned carbon nanotube growth using Langmuir-Blodgett technique

    Science.gov (United States)

    Nakamura, Kentaro; Kuriyama, Naoki; Takagiwa, Shota; Sato, Taiga; Kushida, Masahito

    2016-03-01

    Vertically aligned carbon nanotubes (VA-CNTs) were studied as a new catalyst support for polymer electrolyte fuel cells (PEFCs). Controlling the number density and the diameter of VA-CNTs may be necessary to optimize PEFC performance. As the catalyst for CNT growth, we fabricated Fe or Fe3O4 nanoparticle (NP) films by the Langmuir-Blodgett (LB) technique. The catalyst Fe or Fe3O4 NPs were widely separated by mixing with filler molecules [palmitic acid (C16)]. The number density of VA-CNTs was controlled by varying the ratio of catalyst NPs to C16 filler molecules. The VA-CNTs were synthesized from the catalyst NP-C16 LB films by thermal chemical vapor deposition (CVD) using acetylene gas as the carbon source. The developing solvents used in the LB technique and the hydrogen reduction conditions of CVD were optimized to improve the VA-CNT growth rate. We demonstrate that the proposed method can independently control both the density and the diameter of VA-CNTs.

  4. Integrating terrestrial through aquatic processing of water, carbon and nitrogen over hot, cold and lukewarm moments in mixed land use catchments

    Science.gov (United States)

    Band, L. E.; Lin, L.; Duncan, J. M.

    2017-12-01

    A major challenge in understanding and managing freshwater volumes and quality in mixed land use catchments is the detailed heterogeneity of topography, soils, canopy, and inputs of water and biogeochemicals. The short space and time scale dynamics of sources, transport and processing of water, carbon and nitrogen in natural and built environments can have a strong influence on the timing and magnitude of watershed runoff and nutrient production, ecosystem cycling and export. Hydroclimate variability induces a functional interchange of terrestrial and aquatic environments across their transition zone with the temporal and spatial expansion and contraction of soil wetness, standing and flowing water over seasonal, diurnal and storm event time scales. Variation in sources and retention of nutrients at these scales need to be understood and represented to design optimal mitigation strategies. This paper discusses the conceptual framework used to design both simulation and measurement approaches, and explores these dynamics using an integrated terrestrial-aquatic watershed model of coupled water-carbon-nitrogen processes at resolutions necessary to resolve "hot spot/hot moment" phenomena in two well studied catchments in Long Term Ecological Research sites. The potential utility of this approach for design and assessment of urban green infrastructure and stream restoration strategies is illustrated.

  5. Ecomorphological and taphonomic gradients in clypeasteroid-dominated echinoid assemblages along a mixed siliciclastic-carbonate shelf from the early Miocene of northern Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    Andrea Mancosu

    2017-09-01

    Full Text Available Clypeasteroid echinoids are widespread and abundant within Miocene sedimentary sequences of the Mediterranean area within both siliciclastic and carbonate deposits. Herein, three clypeasteroid-dominated echinoid assemblages from the mixed siliciclastic-carbonate succession of the Mores Formation (lower Miocene cropping out within the Porto Torres Basin (northern Sardinia are described. These assemblages were compared to previously described clypeasteroid-bearing deposits from the Miocene of northern Sardinia with the purpose of investigating their palaeoecology and taphonomy along a shelf gradient. These goals are accomplished by various methods including (i logging sedimentary facies, (ii analysing the functional morphology of sea urchin skeletons, (iii comparing the relative abundance of taxa and taphonomic features, and (iv studying associated fauna, flora, and trace fossils. The clypeasteroid-bearing deposits differ greatly with respect to echinoid diversity, accompanying fauna and flora, sedimentological signatures, and taphonomic features. They also show variations in depositional environments and the mechanism of formation of the deposits. Three different shelf settings are distinguished: littoral, inner sublittoral, and outer sublittoral environments. Furthermore, an ecomorphological gradient along the shelf is recognized with respect to echinoid taxa and their morphologies. This gradient ranges from shallow water to a moderately deep shelf and is interpreted with respect to both abiotic and biotic factors as well as the taphonomy of the echinoid tests.

  6. Separation of carbon dioxide from flue gas by mixed matrix membranes using dual phase microporous polymeric constituents.

    Science.gov (United States)

    Sekizkardes, Ali K; Kusuma, Victor A; Dahe, Ganpat; Roth, Elliot A; Hill, Lawrence J; Marti, Anne; Macala, Megan; Venna, Surendar R; Hopkinson, David

    2016-09-27

    This study presents the fabrication of a new mixed matrix membrane using two microporous polymers: a polymer of intrinsic microporosity PIM-1 and a benzimidazole linked polymer, BILP-101, and their CO 2 separation properties from post-combustion flue gas. 17, 30 and 40 wt% loadings of BILP-101 into PIM-1 were tested, resulting in mechanically stable films showing very good interfacial interaction due to the inherent H-bonding capability of the constituent materials. Gas transport studies showed that BILP-101/PIM-1 membranes exhibit high CO 2 permeability (7200 Barrer) and selectivity over N 2 (15). The selected hybrid membrane was further tested for CO 2 separation using actual flue gas from a coal-fired power plant.

  7. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing

    International Nuclear Information System (INIS)

    Liapis, Ioannis; Papayianni, Ioanna

    2015-01-01

    Highlights: • Addition of 10% perlite decreases specific weight of the slag by approx. 7.5%. • Slag-crucible interaction and thin coating layer result in variations in XRF. • XRD shows high glass content and smaller crystalline sizes due to rapid cooling. • SEM shows higher homogeneity and lower crystallisation for SiO 2 /CaO-rich samples. • Physical properties (LA, PSV, AAV) of modified slag show limited deterioration. - Abstract: Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector

  8. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing

    Energy Technology Data Exchange (ETDEWEB)

    Liapis, Ioannis, E-mail: iliapis@sidenor.vionet.gr [AEIFOROS SA, 12th km Thessaloniki-Veroia Rd, PO Box 59, 57008 Ionia, Thessaloniki (Greece); Papayianni, Ioanna [Laboratory of Building Materials, Department of Civil Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2015-02-11

    Highlights: • Addition of 10% perlite decreases specific weight of the slag by approx. 7.5%. • Slag-crucible interaction and thin coating layer result in variations in XRF. • XRD shows high glass content and smaller crystalline sizes due to rapid cooling. • SEM shows higher homogeneity and lower crystallisation for SiO{sub 2}/CaO-rich samples. • Physical properties (LA, PSV, AAV) of modified slag show limited deterioration. - Abstract: Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector.

  9. Spatiotemporal variation of radon and carbon dioxide concentrations in an underground quarry: coupled processes of natural ventilation, barometric pumping and internal mixing.

    Science.gov (United States)

    Perrier, Frédéric; Richon, Patrick

    2010-04-01

    Radon-222 and carbon dioxide concentrations have been measured during several years at several points in the atmosphere of an underground limestone quarry located at a depth of 18 m in Vincennes, near Paris, France. Both concentrations showed a seasonal cycle. Radon concentration varied from 1200 to 2000 Bq m(-3) in summer to about 800-1400 Bq m(-3) in winter, indicating winter ventilation rates varying from 0.6 to 2.5 x 10(-6) s(-1). Carbon dioxide concentration varied from 0.9 to 1.0% in summer, to about 0.1-0.3% in winter. Radon concentration can be corrected for natural ventilation using temperature measurements. The obtained model also accounts for the measured seasonal variation of carbon dioxide. After correction, radon concentrations still exhibit significant temporal variation, mostly associated with the variation of atmospheric pressure, with coupling coefficients varying from -7 to -26 Bq m(-3) hPa(-1). This variation can be accounted for using a barometric pumping model, coupled with natural ventilation in winter, and including internal mixing as well. After correction, radon concentrations exhibit residual temporal variation, poorly correlated between different points, with standard deviations varying from 3 to 6%. This study shows that temporal variation of radon concentrations in underground cavities can be understood to a satisfactory level of detail using non-linear and time-dependent modelling. It is important to understand the temporal variation of radon concentrations and the limitations in their modelling to monitor the properties of natural or artificial underground settings, and to be able to assess the existence of new processes, for example associated with the preparatory phases of volcanic eruptions or earthquakes. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Spatiotemporal variation of radon and carbon dioxide concentrations in an underground quarry: coupled processes of natural ventilation, barometric pumping and internal mixing

    International Nuclear Information System (INIS)

    Perrier, Frederic; Richon, Patrick

    2010-01-01

    Radon-222 and carbon dioxide concentrations have been measured during several years at several points in the atmosphere of an underground limestone quarry located at a depth of 18 m in Vincennes, near Paris, France. Both concentrations showed a seasonal cycle. Radon concentration varied from 1200 to 2000 Bq m -3 in summer to about 800-1400 Bq m -3 in winter, indicating winter ventilation rates varying from 0.6 to 2.5 x 10 -6 s -1 . Carbon dioxide concentration varied from 0.9 to 1.0% in summer, to about 0.1-0.3% in winter. Radon concentration can be corrected for natural ventilation using temperature measurements. The obtained model also accounts for the measured seasonal variation of carbon dioxide. After correction, radon concentrations still exhibit significant temporal variation, mostly associated with the variation of atmospheric pressure, with coupling coefficients varying from -7 to -26 Bq m -3 hPa -1 . This variation can be accounted for using a barometric pumping model, coupled with natural ventilation in winter, and including internal mixing as well. After correction, radon concentrations exhibit residual temporal variation, poorly correlated between different points, with standard deviations varying from 3 to 6%. This study shows that temporal variation of radon concentrations in underground cavities can be understood to a satisfactory level of detail using non-linear and time-dependent modelling. It is important to understand the temporal variation of radon concentrations and the limitations in their modelling to monitor the properties of natural or artificial underground settings, and to be able to assess the existence of new processes, for example associated with the preparatory phases of volcanic eruptions or earthquakes.

  11. Pliocene-Lower Pleistocene shallow-water mixed siliciclastics and carbonates (Yanigua and Los Haitises formations) in eastern Hispaniola (Dominican Republic)

    Science.gov (United States)

    Braga, Juan C.; Díaz de Neira, Alberto; Lasseur, Eric; Mediato, José; Aguirre, Julio; Abad, Manuel; Hernaiz-Huerta, Pedro P.; Monthel, Jacques; Pérez-Valera, Fernando; Lopera, Eusebio

    2012-07-01

    The virtually unfolded sedimentary cover of the Cordilleras Central and Oriental in the eastern Dominican Republic (eastern Hispaniola, tropical North Atlantic) largely consists of Pliocene to Early Pleistocene mixed siliciclastics and carbonates. These deposits have been grouped into two laterally interfingering mapping units, the Yanigua and Los Haitises formations. The former (mainly siliciclastics) comprises marl, marly limestone, and minor conglomerate, sandstone, lignite, and carbonaceous clay and crops out closest to the basement. The Los Haitises Formation mainly consists of limestone and intercalating beds of marly limestone and marl. Lithological mapping at the 1:50,000 scale and facies analysis of twelve measured sections and of additional fourteen outcrops suggest that these deposits mainly formed on a shallow-water marine platform fringing the precursor reliefs of the Cordillera Oriental and the southeastern end of the Cordillera Central. Only a limited proportion of sediment formed in floodplains and marshes. Marl and marly limestone dominated the inner platform sediments. Terrigenous mud decreased away from the emergent basement and carbonate sedimentation dominated the more external platform. Corals, molluscs, echinoids, foraminifers, bryozoans, coralline algae, and Halimeda are the main components with varying amounts of carbonate mud. The platform was generally a low-energy environment with seagrass patches. In the inner platform, corals grew as isolated colonies or as small patch reefs dominated by Porites in marly and bioclastic substrates. Branching corals (Stylophora and Acropora) grew in extensive carpets in more distal areas. At least in the last stage of its development (Early Pleistocene), the platform was rimmed by a reef barrier similar to the Holocene Caribbean barrier reefs, with Acropora gr. palmata, A. cervicornis, Porites, Montastrea, Siderastrea, and Diploria as the main reef builders.

  12. Characterization of the products attained from a thermal treatment of a mix of zinc-carbon and alkaline batteries.

    Science.gov (United States)

    Kuo, Yi-Ming; Lin, Chitsan; Wang, Jian-Wen; Huang, Kuo-Lin; Tsai, Cheng-Hsien; Wang, Chih-Ta

    2016-01-01

    This study applies a thermal separation process (TSP) to recover Fe, Mn, and Zn from hazardous spent zinc-carbon and alkaline batteries. In the TSP, the batteries were heated together with a reducing additive and the metals in batteries, according to their boiling points and densities, were found to move into three major output materials: slag, ingot (mainly Fe and Mn), and particulate (particularly Zn). The slag well encapsulated the heavy metals of interest and can be recycled for road pavement or building materials. The ingot had high levels of Fe (522,000 mg/kg) and Mn (253,000 mg/kg) and can serve as an additive for stainless steel-making processes. The particulate phase had a Zn level of 694,000 mg/kg which is high enough to be directly sold for refinement. Overall, the TSP effectively recovered valuable metals from the hazardous batteries.

  13. Foliar photochemical processes and carbon metabolism under favourable and adverse winter conditions in a Mediterranean mixed forest, Catalonia (Spain)

    Science.gov (United States)

    Sperlich, D.; Chang, C. T.; Peñuelas, J.; Gracia, C.; Sabaté, S.

    2014-10-01

    Evergreen trees in the Mediterranean region must cope with a wide range of environmental stresses from summer drought to winter cold. The mildness of Mediterranean winters can periodically lead to favourable environmental conditions above the threshold for a positive carbon balance, benefitting evergreen woody species more than deciduous ones. The comparatively lower solar energy input in winter decreases the foliar light saturation point. This leads to a higher susceptibility to photoinhibitory stress especially when chilly (Arbutus unedo L.). Therefore, we collected twigs from the field during a period of mild winter conditions and after a sudden cold period. After both periods, the state of the photosynthetic machinery was tested in the laboratory by estimating the foliar photosynthetic potential with CO2 response curves in parallel with chlorophyll fluorescence measurements. The studied evergreen tree species benefited strongly from mild winter conditions by exhibiting extraordinarily high photosynthetic potentials. A sudden period of frost, however, negatively affected the photosynthetic apparatus, leading to significant decreases in key physiological parameters such as the maximum carboxylation velocity (Vc, max), the maximum photosynthetic electron transport rate (Jmax), and the optimal fluorometric quantum yield of photosystem II (Fv/Fm). The responses of Vc, max and Jmax were highly species specific, with Q. ilex exhibiting the highest and P. halepensis the lowest reductions. In contrast, the optimal fluorometric quantum yield of photosystem II (Fv/Fm) was significantly lower in A. unedo after the cold period. The leaf position played an important role in Q. ilex showing a stronger winter effect on sunlit leaves in comparison to shaded leaves. Our results generally agreed with the previous classifications of photoinhibition-tolerant (P. halepensis) and photoinhibition-avoiding (Q. ilex) species on the basis of their susceptibility to dynamic

  14. Zeolite Combined with Alum and Polyaluminum Chloride Mixed with Agricultural Slurries Reduces Carbon Losses in Runoff from Grassed Soil Boxes.

    Science.gov (United States)

    Murnane, J G; Brennan, R B; Fenton, O; Healy, M G

    2016-11-01

    Carbon (C) losses from agricultural soils to surface waters can migrate through water treatment plants and result in the formation of disinfection by-products, which are potentially harmful to human health. This study aimed to quantify total organic carbon (TOC) and total inorganic C losses in runoff after application of dairy slurry, pig slurry, or milk house wash water (MWW) to land and to mitigate these losses through coamendment of the slurries with zeolite (2.36-3.35 mm clinoptilolite) and liquid polyaluminum chloride (PAC) (10% AlO) for dairy and pig slurries or liquid aluminum sulfate (alum) (8% AlO) for MWW. Four treatments under repeated 30-min simulated rainfall events (9.6 mm h) were examined in a laboratory study using grassed soil runoff boxes (0.225 m wide, 1 m long; 10% slope): control soil, unamended slurries, PAC-amended dairy and pig slurries (13.3 and 11.7 kg t, respectively), alum-amended MWW (3.2 kg t), combined zeolite and PAC-amended dairy (160 and 13.3 kg t zeolite and PAC, respectively) and pig slurries (158 and 11.7 kg t zeolite and PAC, respectively), and combined zeolite and alum-amended MWW (72 and 3.2 kg t zeolite and alum, respectively). The unamended and amended slurries were applied at net rates of 31, 34, and 50 t ha for pig and dairy slurries and MWW, respectively. Significant reductions of TOC in runoff compared with unamended slurries were measured for PAC-amended dairy and pig slurries (52 and 56%, respectively) but not for alum-amended MWW. Dual zeolite and alum-amended MWW significantly reduced TOC in runoff compared with alum amendment only. We conclude that use of PAC-amended dairy and pig slurries and dual zeolite and alum-amended MWW, although effective, may not be economically viable to reduce TOC losses from organic slurries given the relatively low amounts of TOC measured in runoff from unamended slurries compared with the amounts applied. Copyright © by the American Society of Agronomy, Crop Science Society of

  15. Atmospheric carbon tetrachloride in rural background and industry surrounded urban areas in Northern Iberian Peninsula: Mixing ratios, trends, and potential sources

    International Nuclear Information System (INIS)

    Blas, Maite de; Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen; Navazo, Marino; Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley

    2016-01-01

    Latest investigations on atmospheric carbon tetrachloride (CTC) are focused on its ozone depleting potential, adverse effects on the human health, and radiative efficiency and Global Warming Potential as a greenhouse gas. CTC mixing ratios have been thoroughly studied since its restriction under the Montreal Protocol, mostly in remote areas with the aim of reporting long-term trends after its banning. The observed decrease of the CTC background mixing ratio, however, was not as strong as expected. In order to explain this behavior CTC lifetime should be adjusted by estimating the relative significance of its sinks and by identifying ongoing potential sources. Looking for possible sources, CTC was measured with high-time resolution in two sites in Northern Spain, using auto-GC systems and specifically developed acquisition and processing methodologies. The first site, Bilbao, is an urban area influenced by the surrounding industry, where measurements were performed with GC–MSD for a one-year period (2007–2008). The second site, at Valderejo Natural Park (VNP), is a rural background area where measurements were carried out with GC-FID and covering CTC data a nonsuccessive five-year period (2003–2005, 2010–2011, and 2014–2015 years). Median yearly CTC mixing ratios were slightly higher in the urban area (120 pptv) than in VNP (80–100 pptv). CTC was reported to be well mixed in the atmosphere and no sources were noticed to impact the rural site. The observed long-term trend in VNP was in agreement with the estimated global CTC emissions. In the urban site, apart from industrial and commercial CTC sources, chlorine-bleach products used as cleaning agents were reported as promotors of indoor sources. - Highlights: • A methodology was developed to measure CTC using GC-MSD and GC-FID. • CTC ongoing sources were noticed in an industry surrounded urban area. • No noticeable nearby CTC sources impacted the rural site. • Long-term CTC trend in agreement

  16. Atmospheric carbon tetrachloride in rural background and industry surrounded urban areas in Northern Iberian Peninsula: Mixing ratios, trends, and potential sources

    Energy Technology Data Exchange (ETDEWEB)

    Blas, Maite de, E-mail: maite.deblas@ehu.eus [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain); Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain); Navazo, Marino [University College of Engineering of Vitoria-Gasteiz, University of the Basque Country UPV/EHU (Spain); Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain)

    2016-08-15

    Latest investigations on atmospheric carbon tetrachloride (CTC) are focused on its ozone depleting potential, adverse effects on the human health, and radiative efficiency and Global Warming Potential as a greenhouse gas. CTC mixing ratios have been thoroughly studied since its restriction under the Montreal Protocol, mostly in remote areas with the aim of reporting long-term trends after its banning. The observed decrease of the CTC background mixing ratio, however, was not as strong as expected. In order to explain this behavior CTC lifetime should be adjusted by estimating the relative significance of its sinks and by identifying ongoing potential sources. Looking for possible sources, CTC was measured with high-time resolution in two sites in Northern Spain, using auto-GC systems and specifically developed acquisition and processing methodologies. The first site, Bilbao, is an urban area influenced by the surrounding industry, where measurements were performed with GC–MSD for a one-year period (2007–2008). The second site, at Valderejo Natural Park (VNP), is a rural background area where measurements were carried out with GC-FID and covering CTC data a nonsuccessive five-year period (2003–2005, 2010–2011, and 2014–2015 years). Median yearly CTC mixing ratios were slightly higher in the urban area (120 pptv) than in VNP (80–100 pptv). CTC was reported to be well mixed in the atmosphere and no sources were noticed to impact the rural site. The observed long-term trend in VNP was in agreement with the estimated global CTC emissions. In the urban site, apart from industrial and commercial CTC sources, chlorine-bleach products used as cleaning agents were reported as promotors of indoor sources. - Highlights: • A methodology was developed to measure CTC using GC-MSD and GC-FID. • CTC ongoing sources were noticed in an industry surrounded urban area. • No noticeable nearby CTC sources impacted the rural site. • Long-term CTC trend in agreement

  17. A Mixed Matrix Membrane of Poly (4-methyl-1-pentyne Filled with MIL 53 Particles and Its Application in Carbon Dioxide and Nitrogen Separation

    Directory of Open Access Journals (Sweden)

    Reza Abedini

    2016-05-01

    Full Text Available The performance of poly (4-metyl-1-pentyne as mixed matrix membrane (MMM mixed with MIL 53 particles was studied to separate mixtures of carbon dioxide and nitrogen. MIL 53 particles was added to the polymer matrix with 10, 20 and 30 weight percentages. The adsorption of CO2 and N2 gases by MIL 53 was evaluated and the adsorption data was analyzed by Langmuir equation. Structure and thermal/mechanical properties of prepared membranes were characterized by means of FTIR, SEM, TGA and elongation test. Moreover, the gas permeation properties of membranes were studied by measuring the permeation of pure CO2 and N2. Furthermore, for accurate understanding of the gas permeation properties of the membranes, diffusion and solution coefficient of gases in neat membrane and MMMs were calculated using modified time-lag method. The results from TGA analysis showed that the degradation temperature of MMMs was enhanced and increased to 348ºC for membrane containing 30 wt% of MIL 53. The SEM images also illustrated a relatively uniform dispersion of particles with proper polymer/filler interfaces in the polymer matrix. The gas permeation results revealed that the permeability of both gases (especially CO2 increased with increasing MIL 53 loading, in which the permeability of CO2 increased from 98.74 Barrer in neat membrane to 217.65 Barrer in MMM containing 30 wt% filler. Moreover, calculation of CO2/N2 selectivity depicted that the selectivity enhanced from 16.66 to 22.70. Finally, the performance of MMMs was compared with Robeson’s upper bound in CO2/N2 separation and results showed that the MMM having 30 wt% of MIL 53 took over the Robeson bound.

  18. Laser synthesis of a copper–single-walled carbon nanotube nanocomposite via molecular-level mixing and non-equilibrium solidification

    International Nuclear Information System (INIS)

    Tu, Jay F; Rajule, Nilesh; Molian, Pal; Liu, Yi

    2016-01-01

    A copper–single-walled carbon nanotube (Cu–SWCNT) metal nanocomposite could be an ideal material if it can substantially improve the strength of copper while preserving the metal’s excellent thermal and electrical properties. However, synthesis of such a nanocomposite is highly challenging, because copper and SWCNTs do not form intermetallic compounds and are insoluble; as a result, there are serious issues regarding wettability and fine dispersion of SWCNTs within the copper matrix. In this paper we present a novel wet process, called the laser surface implantation process (LSI), to synthesize Cu–SWCNT nanocomposites by mixing SWCNTs into molten copper. The LSI process includes drilling several microholes on a copper substrate, filling the microholes with SWCNTs suspended in solution, and melting the copper substrate to create a micro-well of molten copper. The molten copper advances radially outward to engulf the microholes with pre-deposited SWCNTs to form the Cu–SWCNT implant upon solidification. Rapid and non-equilibrium solidification is achieved due to copper’s excellent heat conductivity, so that SWCNTs are locked in position within the copper matrix without agglomerating into large clusters. This wet process is very different from the typical dry processes used in powder metallurgy. Very high hardness improvement, up to 527% over pure copper, was achieved, confirmed by micro-indentation tests, with only a 0.23% SWCNT volume fraction. The nanostructure of the nanocomposite was characterized by TEM imaging, energy-dispersive x-ray spectroscopy mapping and spectroscopy measurements. The SWCNTs were found to be finely dispersed within the copper matrix with cluster sizes in the range of nanometers, achieving the goal of molecular-level mixing. (paper)

  19. Mixed ion-exchanger chemically modified carbon paste ion-selective electrodes for determination of triprolidine hydrochloride

    Directory of Open Access Journals (Sweden)

    Yousry M. Issa

    2010-01-01

    Full Text Available Triprolidine hydrochloride (TpCl ion-selective carbon paste electrodes were constructed using Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA as ion-exchangers. The two electrodes revealed Nernstian responses with slopes of 58.4 and 58.1 mV decade−1 at 25 °C in the ranges 6 × 10−6–1 × 10−2 and 2 × 10−5–1 × 10−2 M for Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA, respectively. The potentials of these electrodes were independent of pH in the ranges of 2.5–7.0 and 4.5–7.0, and detection limits were 6 × 10−6 and 1 × 10−5 M for Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA, respectively. The electrodes showed a very good selectivity for TpCl with respect to a large number of inorganic cations and compounds. The standard addition, potentiometric titration methods and FIA were applied to the determination of TpCl in pure solutions and pharmaceutical preparations. The results obtained were in close agreement with those found by the official method. The mean recovery values were 100.91% and 97.92% with low coefficient of variation values of 0.94%, and 0.56% in pure solutions, 99.82% and 98.53% with coefficient of variation values of 2.20%, and 0.73% for Actifed tablet and Actifed syrup, respectively, using the Tp-TPB/Tp-CoN electrode, and 98.85%, and 99.18% with coefficient of variation values of 0.48% and 0.85% for Actifed tablet and Actifed syrup, respectively, using the Tp-TPB/Tp-PTA electrode.

  20. Mixed-species allometric equations and estimation of aboveground biomass and carbon stocks in restoring degraded landscape in northern Ethiopia

    Science.gov (United States)

    Mokria, Mulugeta; Mekuria, Wolde; Gebrekirstos, Aster; Aynekulu, Ermias; Belay, Beyene; Gashaw, Tadesse; Bräuning, Achim

    2018-02-01

    Accurate biomass estimation is critical to quantify the changes in biomass and carbon stocks following the restoration of degraded landscapes. However, there is lack of site-specific allometric equations for the estimation of aboveground biomass (AGB), which consequently limits our understanding of the contributions of restoration efforts in mitigating climate change. This study was conducted in northwestern Ethiopia to develop a multi-species allometric equation and investigate the spatial and temporal variation of C-stocks following the restoration of degraded landscapes. We harvested and weighed 84 trees from eleven dominant species from six grazing exclosures and adjacent communal grazing land. We observed that AGB correlates significantly with diameter at stump height D 30 (R 2 = 0.78 P < 0.01), and tree height H (R 2 = 0.41, P < 0.05). Our best model, which includes D 30 and H as predictors explained 82% of the variations in AGB. This model produced the lowest bias with narrow ranges of errors across different diameter classes. Estimated C-stock showed a significant positive correlation with stem density (R 2 = 0.80, P < 0.01) and basal area (R 2 = 0.84, P < 0.01). At the watershed level, the mean C-stock was 3.8 (±0.5) Mg C ha-1. Plot-level C-stocks varied between 0.1 and 13.7 Mg C ha-1. Estimated C-stocks in three- and seven-year-old exclosures exceeded estimated C-stock in the communal grazing land by 50%. The species that contribute most to C-stocks were Leucaena sp. (28%), Calpurnia aurea (21%), Euclea racemosa (20.9%), and Dodonaea angustifolia (15.8%). The equations developed in this study allow monitoring changes in C-stocks and C-sequestration following the implementation of restoration practices in northern Ethiopia over space and time. The estimated C-stocks can be used as a reference against which future changes in C-stocks can be compared.

  1. Direct in situ measurement of Carbon Allocation to Mycorrhizal Fungi in a California Mixed-Conifer Forest

    Science.gov (United States)

    Allen, M.

    2012-04-01

    Mycorrhizal fungi consume fixed C in ecosystems in exchange for soil resources. We used sensor and observation platforms belowground to quantify belowground dynamics in a California mixed-conifer ecosystem. We directly observed growth and mortality of mycorrhizal fungi in situ on a daily basis using an automated minirhizotron. We measured soil CO2, T and soil moisture at 5-min intervals into the soil profile. These data are coupled with sensors measuring eddy flux of water and CO2, sapflow for water fluxes and C fixation activity, and photographs for leaf phenology. We used DayCent modeling for net primary productivity (NPP) and measured NPP of rhizomorphs, and fungal hyphae. In an arbuscular mycorrhizal (AM) meadow, NPP was 141g/m2/y, with a productivity of fine root NPP of 76.5g C/m2/y, an estimated 10 percent of which is AM fungal C (7.7 g/m2/y). Extramatrical AM hyphal peak standing crop was 4.4g/m2, with a lifespan of 46 days, with active hyphae persisting for 240 days per year. The extramatrical AM fungal hyphal C was 22.9g/m2/y, for a total net allocation to AM fungi of 30.5 C/m2/y, or 22 percent of the estimated NPP. In the ectomycorrhizal (EM) forest, root standing crop (200g C/m2/y) and rhizomorph (2mg C/m2/y) was 33 percent of the NPP (600g C/m2/y). EM fungal hyphae standing crop was 18g/m2/y, with a 48day lifespan, persisting throughout the year, or 59 g C/m2/y. EM root tips and rhizomorph life spans were nearly a year. Assuming that EM fungi represent 40 percent of the fine root EM NPP (of 200g C/m2/y) or 80g C/m2/y, most of the rhizomorph (in the mineral soil) mass being EM (or 2mg C), and 57 percent of the soil fungal NPP or 80 g C/m2/y, then the EM NPP is 139 C/m2/y, or 23 percent of the estimated NPP (600g C/m2/y). As an independent check on the allocation of C, we applied the Hobbie and Hobbie isotopic fractionation d15N model to C allocation. Using d15N of Chantarellus sp. (10.6) and Rhizopogon sp. (9.1), with a leaf d15N of -4.9, we estimated

  2. Strategies for efficiently selecting PHA producing mixed microbial cultures using complex feedstocks: Feast and famine regime and uncoupled carbon and nitrogen availabilities.

    Science.gov (United States)

    Oliveira, Catarina S S; Silva, Carlos E; Carvalho, Gilda; Reis, Maria A

    2017-07-25

    Production of polyhydroxyalkanoates (PHAs) by open mixed microbial cultures (MMCs) has been attracting increasing interest as an alternative technology to PHA production by pure cultures, due to the potential for lower costs associated with the use of open systems (eliminating the requirement for sterile conditions) and the utilisation of cheap feedstock (industrial and agricultural wastes). Such technology relies on the efficient selection of an MMC enriched in PHA-accumulating organisms. Fermented cheese whey, a protein-rich complex feedstock, has been used previously to produce PHA using the feast and famine regime for selection of PHA accumulating cultures. While this selection strategy was found efficient when operated at relatively low organic loading rate (OLR, 2g-CODL -1 d -1 ), great instability and low selection efficiency of PHA accumulating organisms were observed when higher OLR (ca. 6g-CODL -1 d -1 ) was applied. High organic loading is desirable as a means to enhance PHA productivity. In the present study, a new selection strategy was tested with the aim of improving selection for high OLR. It was based on uncoupling carbon and nitrogen supply and was implemented and compared with the conventional feast and famine strategy. For this, two selection reactors were fed with fermented cheese whey applying an OLR of ca. 8.5g-CODL -1 (with 3.8g-CODL -1 resulting from organic acids and ethanol), and operated in parallel under similar conditions, except for the timing of nitrogen supplementation. Whereas in the conventional strategy nitrogen and carbon substrates were added simultaneously at the beginning of the cycle, in the uncoupled substrates strategy, nitrogen addition was delayed to the end of the feast phase (i.e. after exogenous carbon was exhausted). The two different strategies selected different PHA-storing microbial communities, dominated by Corynebacterium and a Xantomonadaceae, respectively with the conventional and the new approaches. The new

  3. Mixed-carbon-coated LiMn_0_._4Fe_0_._6PO_4 nanopowders with excellent high rate and low temperature performances for lithium-ion batteries

    International Nuclear Information System (INIS)

    Zou, Bang-Kun; Wang, He-Yang; Qiang, Zi-Yue; Shao, Yu; Sun, Xin; Wen, Zhao-Yin; Chen, Chun-Hua

    2016-01-01

    Graphical abstract: Ascorbic acid acts as both an antioxidant and a surfactant to form organic groups (first carbon source) on the surface of as-solvothermal products, in which the −OH (or H_2O) groups of glucose (second carbon source) are closely bonded to the surface to form a uniform adsorption layer. Uniform mixed-carbon-coated LiMn_0_._4Fe_0_._6PO_4 nanopowders are formed after calcination, which demonstrate excellent electrochemical performances. - Highlights: • Ascorbic acid acts as both an antioxidant and a first-time carbon coating source. • Reaction mechanisms of the synthesis are carefully studied. • Mixed-carbon-coated LiMn_0_._4Fe_0_._6PO_4 nanopowders process excellent high rate and low temperature performances. - Abstract: A novel solvothermal approach with ascorbic acid as both an antioxidant and a first-time carbon coating source is developed to synthesize LiMn_0_._4Fe_0_._6PO_4 nano-particles with a uniform particle size distribution around 150 nm. A calcination step for the second-time carbon coating and further crystallization is adopted following the solvothermal step. The structures and electrochemical properties of the obtained samples are studied by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, Fourier transformation infrared, Infrared carbon-sulfur analyzer and galvanostatic cell cycling. Ascorbic acid plays a crucial role in the formation of uniform carbon layer and nano-particles. Compared with single-carbon-coated LiMn_0_._4Fe_0_._6PO_4 without adding ascorbic acid, the mixed-carbon-coated LiMn_0_._4Fe_0_._6PO_4 shows much better electrochemical performance. It can deliver specific capacities of 154.8 and 128.5 mAh g"−"1 at 1C and 20C, respectively, at 25 °C. Even at −20 °C, its specific capacities are 106.6 and 68.8 mAh g"−"1 at 0.2C and 5C, respectively.

  4. Development and Characterization of Defect-Free Matrimid® Mixed-Matrix Membranes Containing Activated Carbon Particles for Gas Separation

    Directory of Open Access Journals (Sweden)

    Fynn Weigelt

    2018-01-01

    Full Text Available In this work, mixed-matrix membranes (MMMs for gas separation in the form of thick films were prepared via the combination of the polymer Matrimid® 5218 and activated carbons (AC. The AC particles had a mean particle size of 1.5 μm and a mean pore diameter of 1.9 nm. The films were prepared by slow solvent evaporation from casting solutions in chloroform, which had a varying polymer–AC ratio. It was possible to produce stable films with up to a content of 50 vol % of AC. Thorough characterization experiments were accomplished via differential scanning calorimetry and thermogravimetric analysis, while the morphology of the MMMs was also investigated via scanning electron microscopy. The gas transport properties were revealed by employing time-lag measurements for different pure gases as well as sorption balance experiments for the filler particles. It was found that defect free Matrimid® MMMs with AC were prepared and the increase of the filler content led to a higher effective permeability for different gases. The single gas selectivity αij of different gas pairs maintained stable values with the increase of AC content, regardless of the steep increase in the effective permeability of the pure gases. Estimation of the solubilities and the diffusivities of the Matrimid®, AC, and MMMs allowed for the explanation of the increasing permeabilities of the MMMs, with the increase of AC content by modelling.

  5. Integrating seawater desalination and wastewater reclamation forward osmosis process using thin-film composite mixed matrix membrane with functionalized carbon nanotube blended polyethersulfone support layer.

    Science.gov (United States)

    Choi, Hyeon-Gyu; Son, Moon; Choi, Heechul

    2017-10-01

    Thin-film composite mixed matrix membrane (TFC MMM) with functionalized carbon nanotube (fCNT) blended in polyethersulfone (PES) support layer was synthesized via interfacial polymerization and phase inversion. This membrane was firstly tested in lab-scale integrating seawater desalination and wastewater reclamation forward osmosis (FO) process. Water flux of TFC MMM was increased by 72% compared to that of TFC membrane due to enhanced hydrophilicity. Although TFC MMM showed lower water flux than TFC commercial membrane, enhanced reverse salt flux selectivity (RSFS) of TFC MMM was observed compared to TFC membrane (15% higher) and TFC commercial membrane (4% higher), representing membrane permselectivity. Under effluent organic matter (EfOM) fouling test, 16% less normalized flux decline of TFC MMM was observed compared to TFC membrane. There was 8% less decline of TFC MMM compared to TFC commercial membrane due to fCNT effect on repulsive foulant-membrane interaction enhancement, caused by negatively charged membrane surface. After 10 min physical cleaning, TFC MMM displayed higher recovered normalized flux than TFC membrane (6%) and TFC commercial membrane (4%); this was also supported by visualized characterization of fouling layer. This study presents application of TFC MMM to integrated seawater desalination and wastewater reclamation FO process for the first time. It can be concluded that EfOM fouling of TFC MMM was suppressed due to repulsive foulant-membrane interaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. CORAL ASSEMBLAGES AND BIOCONSTRUCTIONS ADAPTED TO THE DEPOSITIONAL DYNAMICS OF A MIXED CARBONATE-SILICICLASTIC SETTING: THE CASE STUDY OF THE BURDIGALIAN BONIFACIO BASIN (SOUTH CORSICA

    Directory of Open Access Journals (Sweden)

    MARCO BRANDANO

    2016-03-01

    Full Text Available Coral bioconstructions associated with mixed carbonate-siliciclastic settings are known to be strongly controlled by coastal morphology and paleotopography. A striking example is represented by the different types of coral bioconstructions and coral-rich deposits of the Cala di Labra Formation deposited in the coastal environment of the Bonifacio Basin (Corsica, France during the Early Miocene. Detailed mapping on photomosaics allowed accurate documentation of the internal organization of coral deposits as well as lateral and vertical facies relationships. Four types of coral bioconstructions (CB  and one reworked coral deposits (RCD have been recognized. The CB are represented by sigmoidal cluster reefs, coral carpets and skeletal conglomerates rich in corals. The RCD occurs in lens-shaped bodies intercalated within clinoforms composed of bioclastic floatstones and coarse packstones. The investigated bioconstructions can be contextualised in a coastal environment. In the upper shoreface corals developed in association with the oyster Hyotissa, above bioclastic conglomerates sourced by ephemeral streams and erosion of the granitic coastline. In the lower shoreface corals formed sigmoidal bioconstructions interpreted as cluster reefs, whereas  coral carpets developed during a relative sea-level rise related to the middle Burdigalian transgressive phase. The reworked coral deposits can be interpreted as lobe-shaped deposits of coarse-grained bioclastic submarine fans formed at the base of the depositional slope of an infralittoral prograding wedge system.

  7. Impact of modified diamond-like carbon coatings on the spatial organization and disinfection of mixed-biofilms composed of Escherichia coli and Pantoea agglomerans industrial isolates.

    Science.gov (United States)

    Gomes, L C; Deschamps, J; Briandet, R; Mergulhão, F J

    2018-07-20

    This work investigated the effects of diamond-like carbon (DLC) coatings on the architecture and biocide reactivity of dual-species biofilms mimicking food processing contaminants. Biofilms were grown using industrial isolates of Escherichia coli and Pantoea agglomerans on bare stainless steel (SST) and on two DLC surface coatings (a-C:H:Si:O designated by SICON® and a-C:H:Si designated by SICAN) in order to evaluate their antifouling activities. Quantification and spatial organization in single- and dual-species biofilms were examined by confocal laser scanning microscopy (CLSM) using a strain specific labelling procedure. Those assays revealed that the E. coli isolate exhibited a higher adhesion to the modified surfaces and a decreased susceptibility to disinfectant in presence of P. agglomerans than alone in axenic culture. While SICON® reduced the short-term growth of E. coli in axenic conditions, both DLC surfaces increased the E. coli colonization in presence of P. agglomerans. However, both modified surfaces triggered a significantly higher log reduction of E. coli cells within mixed-species biofilms, thus the use of SICON® and SICAN surfaces may be a good approach to facilitate the disinfection process in critical areas of food processing plants. This study presents a new illustration of the importance of interspecies interactions in surface-associated community functions, and of the need to evaluate the effectiveness of hygienic strategies with relevant multi-species consortia. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Radiolytic synthesis of carbon-supported PtRu nanoparticles using high-energy electron beam: effect of pH control on the PtRu mixing state and the methanol oxidation activity

    International Nuclear Information System (INIS)

    Ohkubo, Yuji; Kageyama, Satoru; Seino, Satoshi; Nakagawa, Takashi; Kugai, Junichiro; Nitani, Hiroaki; Ueno, Koji; Yamamoto, Takao A.

    2013-01-01

    Electrode catalysts composed of carbon-supported PtRu nanoparticles (PtRu/C) for use as a direct methanol fuel cell anode were synthesized by the reduction of precursor ions in an aqueous solution via irradiation with a high-energy electron beam. The effect of pH control in the precursor solution on the PtRu mixing state and the methanol oxidation activity was studied in order to enhance the catalytic activity for methanol oxidation. The PtRu/C structures were characterized by transmission electron microscopy, inductively coupled plasma atomic emission spectrometry, X-ray fluorescence spectrometry, and X-ray diffraction and X-ray absorption fine structure techniques. The methanol oxidation activity was evaluated by linear sweep voltammetry. The initial pH of the precursor solution has little influence on the average grain size for the metal particles (approximately 3.5 nm) on the carbon particle supports, but the dispersibility of the metal particles, PtRu mixing state, and methanol oxidation activity differed. The maintenance of a low pH in the precursor solution gave the best dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles, whereas, a high pH gave the best PtRu mixing state and the highest oxidation current although a low dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles was obtained. The PtRu mixing state strongly correlated with the methanol oxidation current. In addition, a high pH was more effective for PtRu mixing when using an electron beam irradiation reduction method, because the complexation reaction of the chelating agents was improved, which resulted in an enhancement of the catalytic activity for methanol oxidation.

  9. Radiolytic synthesis of carbon-supported PtRu nanoparticles using high-energy electron beam: effect of pH control on the PtRu mixing state and the methanol oxidation activity

    Energy Technology Data Exchange (ETDEWEB)

    Ohkubo, Yuji, E-mail: okubo@mit.eng.osaka-u.ac.jp; Kageyama, Satoru; Seino, Satoshi; Nakagawa, Takashi; Kugai, Junichiro [Osaka University, Graduate School of Engineering (Japan); Nitani, Hiroaki [High Energy Accelerator Research Organization (KEK), Institute of Materials Structure Science (Japan); Ueno, Koji [Japan Electron Beam Irradiation Service Ltd (Japan); Yamamoto, Takao A. [Osaka University, Graduate School of Engineering (Japan)

    2013-05-15

    Electrode catalysts composed of carbon-supported PtRu nanoparticles (PtRu/C) for use as a direct methanol fuel cell anode were synthesized by the reduction of precursor ions in an aqueous solution via irradiation with a high-energy electron beam. The effect of pH control in the precursor solution on the PtRu mixing state and the methanol oxidation activity was studied in order to enhance the catalytic activity for methanol oxidation. The PtRu/C structures were characterized by transmission electron microscopy, inductively coupled plasma atomic emission spectrometry, X-ray fluorescence spectrometry, and X-ray diffraction and X-ray absorption fine structure techniques. The methanol oxidation activity was evaluated by linear sweep voltammetry. The initial pH of the precursor solution has little influence on the average grain size for the metal particles (approximately 3.5 nm) on the carbon particle supports, but the dispersibility of the metal particles, PtRu mixing state, and methanol oxidation activity differed. The maintenance of a low pH in the precursor solution gave the best dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles, whereas, a high pH gave the best PtRu mixing state and the highest oxidation current although a low dispersibility of the PtRu nanoparticles supported on the surface of the carbon particles was obtained. The PtRu mixing state strongly correlated with the methanol oxidation current. In addition, a high pH was more effective for PtRu mixing when using an electron beam irradiation reduction method, because the complexation reaction of the chelating agents was improved, which resulted in an enhancement of the catalytic activity for methanol oxidation.

  10. Carbon balance of a partially harvested mixed conifer forest following mountain pine beetle attack and its comparison to a clear-cut

    Directory of Open Access Journals (Sweden)

    A. Mathys

    2013-08-01

    Full Text Available The recent mountain pine beetle (MPB outbreak has had an impact on the carbon (C cycling of lodgepole pine forests in British Columbia. This study examines how partial harvesting as a forest management response to MPB infestation affects the net ecosystem production (NEP of a mixed conifer forest (MPB-09 in Interior BC. MPB-09 is a 70-year-old stand that was partially harvested in 2009 after it had been attacked by MPB. Using the eddy-covariance technique, the C dynamics of the stand were studied over two years and compared to an adjacent clear-cut (MPB-09C over the summertime. The annual NEP at MPB-09 increased from −108 g C m−2 in 2010 to −57 g C m−2 in 2011. The increase of NEP was due to the associated increase in annual gross ecosystem photosynthesis (GEP from 812 g C m−2 in 2010 to 954 g C m−2 in 2011, exceeding the increase in annual respiration (Re from 920 g C m−2 to 1011 g C m−2 during the two years. During the four month period between June and September 2010, NEP at MPB-09C was −103 g C m−2, indicating high C losses in the clear-cut. MPB-09 was a C sink during the growing season of both years, increasing from 9 g C m−2 in 2010 to 47 g C m−2 in 2011. The increase of NEP in the partially harvested stand amounted to a recovery corresponding to a 26% increase in the maximum assimilation rate in the second year. This study shows that retaining the healthy residual forest can result in higher C sequestration of MPB-attacked stands compared to clear-cut harvesting.

  11. The Use of Mixed Effects Models for Obtaining Low-Cost Ecosystem Carbon Stock Estimates in Mangroves of the Asia-Pacific

    Science.gov (United States)

    Bukoski, J. J.; Broadhead, J. S.; Donato, D.; Murdiyarso, D.; Gregoire, T. G.

    2016-12-01

    Mangroves provide extensive ecosystem services that support both local livelihoods and international environmental goals, including coastal protection, water filtration, biodiversity conservation and the sequestration of carbon (C). While voluntary C market projects that seek to preserve and enhance forest C stocks offer a potential means of generating finance for mangrove conservation, their implementation faces barriers due to the high costs of quantifying C stocks through measurement, reporting and verification (MRV) activities. To streamline MRV activities in mangrove C forestry projects, we develop predictive models for (i) biomass-based C stocks, and (ii) soil-based C stocks for the mangroves of the Asia-Pacific. We use linear mixed effect models to account for spatial correlation in modeling the expected C as a function of stand attributes. The most parsimonious biomass model predicts total biomass C stocks as a function of both basal area and the interaction between latitude and basal area, whereas the most parsimonious soil C model predicts soil C stocks as a function of the logarithmic transformations of both latitude and basal area. Random effects are specified by site for both models, and are found to explain a substantial proportion of variance within the estimation datasets. The root mean square error (RMSE) of the biomass C model is approximated at 24.6 Mg/ha (18.4% of mean biomass C in the dataset), whereas the RMSE of the soil C model is estimated at 4.9 mg C/cm 3 (14.1% of mean soil C). A substantial proportion of the variation in soil C, however, is explained by the random effects and thus the use of the SOC model may be most valuable for sites in which field measurements of soil C exist.

  12. [Values of mixed venous oxygen saturation and difference of mixed venous-arterial partial pressure of carbon dioxide in monitoring of oxygen metabolism and treatment after open-heart operation].

    Science.gov (United States)

    Pan, Chuanliang; Zhang, Haiying; Liu, Jianping

    2014-10-01

    To explore the clinic values of early goal directed treatment (EGDT) with the target of mixed venous oxygen saturation (SvO₂) and difference of mixed venous-arterial partial pressure of carbon dioxide (Pv-aCO₂) in monitoring of oxygen metabolism and treatment for patients post open-heart operation. A prospective study was conducted. The adult patients admitted to Third People's Hospital of Chengdu from December 2011 to March 2014 with SvO₂2 mmol/L when admitted in intensive care unit (ICU) were selected on whom elective open-heart operation and pulmonary artery catheter examination were done. All patients received EGDT with the target of SvO₂≥0.65 and Pv-aCO₂<6 mmHg (1 mmHg=0.133 kPa) and were divided into three groups by the values of SvO₂and Pv-aCO₂at 6-hour after ICU admission: A group with SvO₂≥0.65 and Pv-aCO₂<6 mmHg, B group with SvO₂≥0.65 and Pv-aCO₂≥6 mmHg, and C group with SvO₂<0.65. Then the changes and prognosis of the patients in different groups were observed. 103 cases were included, 44 in A group, 31 in B group and 28 in C group. The acute physiology and chronic health evaluation II (APACHEII) score in group A were significantly lower than that in group B or C at 6, 24, 48 and 72 hours (T6, T24, T48, T72) of ICU admission (T6: 11.4 ± 5.8 vs. 13.9 ± 5.4, 13.7 ± 6.4; T24: 8.8 ± 3.7 vs. 10.8 ± 4.8, 11.8 ± 5.4; T48: 8.7 ± 4.1 vs. 9.6 ± 4.2, 10.2 ± 5.1; T72: 7.5 ± 3.4 vs. 8.6 ± 2.9, 9.2 ± 4.2, all P<0.05), and the sequential organ failure assessment (SOFA) showed the same tendency (T6: 6.5 ± 4.3 vs. 8.0 ± 3.8, 9.1 ± 4.5; T24: 6.6 ±3.6 vs. 8.6 ± 3.9, 8.5 ± 3.3; T48: 5.2 ± 3.4 vs. 7.0 ± 3.6, 7.6 ± 5.1; T72: 4.6 ± 2.4 vs. 5.8 ± 2.5, 6.8 ± 3.5, all P<0.05). The values of blood lactic acid (mmol/L) in group A and B were significant lower than that in group C at T6, T24, T48 and T72 (T6: 1.60 ± 0.95, 2.20 ± 1.02 vs. 2.55 ± 1.39; T24: 2.26 ± 1.26, 2.70 ± 1.36 vs. 3.34 ± 2.36; T48: 2.01 ± 1.15, 2.17

  13. High pressure pure- and mixed-gas separation of CO2/CH4 by thermally-rearranged and carbon molecular sieve membranes derived from a polyimide of intrinsic microporosity

    KAUST Repository

    Swaidan, Raja

    2013-11-01

    Natural gas sweetening, one of the most promising venues for the growth of the membrane gas separation industry, is dominated by polymeric materials with relatively low permeabilities and moderate selectivities. One strategy towards improving the gas transport properties of a polymer is enhancement of microporosity either by design of polymers of intrinsic microporosity (PIMs) or by thermal treatment of polymeric precursors. For the first time, the mixed-gas CO2/CH4 transport properties are investigated for a complete series of thermally-rearranged (TR) (440°C) and carbon molecular sieve (CMS) membranes (600, 630 and 800°C) derived from a polyimide of intrinsic microporosity (PIM-6FDA-OH). The pressure dependence of permeability and selectivity is reported up to 30bar for 1:1, CO2:CH4 mixed-gas feeds at 35°C. The TR membrane exhibited ~15% higher CO2/CH4 selectivity relative to pure-gas feeds due to reductions in mixed-gas CH4 permeability reaching 27% at 30bar. This is attributed to increased hindrance of CH4 transport by co-permeation of CO2. Interestingly, unusual increases in mixed-gas CH4 permeabilities relative to pure-gas values were observed for the CMS membranes, resulting in up to 50% losses in mixed-gas selectivity over the applied pressure range. © 2013 Elsevier B.V.

  14. Effect of microwave irradiation on hydrogen sorption properties of hand mixed MgH{sub 2} – 10 wt.% carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Awad, A.S. [Université de Bordeaux, ICMCB-CNRS, 87 Avenue du Dr Schweitzer, F-33600 Pessac (France); LCPM/PR2N, Université Libanaise, Faculté des Sciences 2, 90656 Jdeidet El Matn (Lebanon); Nakhl, M.; Zakhour, M. [LCPM/PR2N, Université Libanaise, Faculté des Sciences 2, 90656 Jdeidet El Matn (Lebanon); Santos, S.F.; Souza, F.L. [Universidade Federal do ABC, Avenida dos Estados 5001, 09210-580 Santo André – SP (Brazil); Bobet, J.-L., E-mail: jean-louis.bobet@u-bordeaux.fr [Université de Bordeaux, ICMCB-CNRS, 87 Avenue du Dr Schweitzer, F-33600 Pessac (France)

    2016-08-15

    The effect of microwave (MW) irradiation on the hydrogen sorption properties of magnesium powder is explored in the present work. MgH{sub 2} – 10 wt.% CFs (CFs = Carbons Fibers) was prepared by hand mixing, dehydrogenated under microwave irradiation for 20 s and then hydrogenated/dehydrogenated at about 300 °C – 1 MPa and 330 °C–0.03 MPa to investigate the effect of microwave irradiation on the solid/gas sorption properties. It has to be noted that the hydrogen absorption capacity and sorption kinetics of the MgH{sub 2} – 10 wt.% CFs mixture increased after dehydriding under MW irradiation. The MgH{sub 2} – 10 wt.% CFs mixture dehydrogenated by microwave irradiation can absorb about 5.8 wt.% and 5.3 wt.% H at 330 and 300 °C, respectively, within 2 h while the as-prepared MgH{sub 2} – 10 wt.% CFs mixture absorb only 4.6 wt.% H within the same duration. It is also demonstrated that MgH{sub 2} – 10 wt.% CFs mixture dehydrogenated by microwave irradiation exhibited good hydrogen desorption properties and, as an example, a microwave irradiated sample could release 5.8 wt.% H within 1 h at 330 °C in comparison to the as-prepared MgH{sub 2} – 10 wt.% CFs mixture which desorbed 4.4 wt.% H within 3 h. Scanning electron microscopy (SEM) images revealed that the particle sizes of the MW dehydrogenated mixture decreased after several solid/gas sorption cycles. This contribute to the improvement of hydrogen storage properties of the microwaves dehydrogenated MgH{sub 2} – 10 wt.% CFs mixture. In addition, the hydrogenated MgH{sub 2} – 10 wt.% CFs mixture show reproducible and better microwave-assisted dehydriding reaction during second microwaves cycle. - Highlights: • Dehydriding reaction of MgH{sub 2} by microwave method. • Effect of microwaves treatment on the hydrogen sorption properties of Mg. • Effect of discontinuous microwaves irradiation.

  15. Quantifying Fire's Impacts on Total and Pyrogenic Carbon Stocks in Mixed-Conifer Forests: Results from Pre- and Post-Fire Measurements in Active Wildfire Incidents

    Science.gov (United States)

    Miesel, J. R.; Reiner, A. L.; Ewell, C. M.; Sanderman, J.; Maestrini, B.; Adkins, J.

    2016-12-01

    Widespread US fire suppression policy has contributed to an accumulation of vegetation in many western forests relative to historic conditions, and these changes can exacerbate wildfire severity and carbon (C) emissions. Serious concern exists about positive feedbacks between wildfire emissions and global climate; however, fires not only release C from terrestrial to atmospheric pools, they also create "black" or pyrogenic C (PyC) which contributes to longer-term C stability. Our objective was to quantify wildfire impacts on aboveground and belowground total C and PyC stocks in California mixed-conifer forests. We worked with incident management teams to access five active wildfires to establish and measure plots within days before and after fire. We measured pre- and post-fire aboveground forest structure and woody fuels to calculate aboveground biomass, biomass C, and PyC, and we collected pre- and post-fire forest floor and 0-5 cm mineral soil samples to measure belowground C and PyC stocks. Our preliminary results show that fire had minimal impact on the number of trees per hectare, whereas C losses from the tree layer occurred via consumption of foliage, and PyC gain occurred in tree bark. Fire released 54% to 100% of surface fuel C. In the forest floor layer, we observed 33 to 100% C loss, whereas changes in PyC stocks ranged from 100% loss to 186% gain relative to pre-fire samples. In general, fire had minimal to no impact on 0-5 cm mineral soil C. We will present relationships between total C, PyC and post-fire C and N dynamics in one of the five wildfire sites. Our data are unique because they represent nearly immediate pre- and post-fire measurements in major wildfires in a widespread western U.S. forest type. This research advances understanding of the role of fire on forest C fluxes and C sequestration potential as PyC.

  16. FACIES PARTITIONING AND SEQUENCE STRATIGRAPHY OF A MIXED SILICICLASTIC-CARBONATE RAMP STACK IN THE GELASIAN OF SICILY (S ITALY: A POTENTIAL MODEL FOR ICEHOUSE, DISTALLY-STEEPENED HETEROZOAN RAMPS

    Directory of Open Access Journals (Sweden)

    FRANCESCO MASSARI

    2012-11-01

    Full Text Available The Gelasian succession of the Capodarso area (Enna-Caltanissetta basin, Sicily, Italy consists of an offlapping stack of cycles composed of siliciclastic units passing to carbonate heterozoan, clino-stratified wedges, developed from a growing positive tectonic structure. Identification of a number of facies tracts, based on sedimentary facies, biofacies and taphofacies, provided important information about the differentiation and characterisation of systems tracts and key stratal surfaces of sequence stratigraphy. The bulk of carbonate wedges are interpreted as representing the rapid falling-stage progradation of distally steepened ramps. The inferred highest rate of carbonate production during forced regressions was concomitant with active downramp resedimentation by storm-driven downwelling flows, leading to storing of most carbonate sediment on the ramp slope as clino-beds of the prograding bodies. Comparison of the Capodarso ramps with other icehouse carbonate ramps, with particular regard to the Mediterranean Plio-Pleistocene, provides clues for defining some common features. These are inferred to include: (1 brief, rapid episodes of progradation concomitant with orbitally-forced sea-level changes, resulting in limited ramp width; (2 preferential fostering of growth and downramp resedimentation of heterozoan carbonates during glacial hemicycles marked by enhanced atmospheric and marine circulation; (3 building out from positive features of entirely submerged distally-steepened ramps with storm-wave-graded profile and distinctive clinoforms; (4 ramp stacks generally consisting of mixed clastic-carbonate sequences showing an ordered spectrum of distinct frequencies; (5 rapid, continuous changes in environmental parameters, leading to the short-lived persistence of faunal communities, climax communities generally having insufficient time to form. 

  17. Effect of fiber angle orientation and stacking sequence on mixed mode fracture toughness of carbon fiber reinforced plastics: Numerical and experimental investigations

    International Nuclear Information System (INIS)

    Naghipour, P.; Bartsch, M.; Chernova, L.; Hausmann, J.; Voggenreiter, H.

    2010-01-01

    This paper focuses on the effect of fiber orientation and stacking sequence on the progressive mixed mode delamination failure in composite laminates using fracture experiments and finite element (FE) simulations. Every laminate is modelled numerically combining damageable layers with defined fiber orientations and cohesive zone interface elements, subjected to mixed mode bending. The numerical simulations are then calibrated and validated through experiments, conducted following standardized mixed mode delamination tests. The numerical model is able to successfully capture the experimentally observed effects of fiber angle orientations and variable stacking sequences on the global load-displacement response and mixed mode inter-laminar fracture toughness of the various laminates. For better understanding of the failure mechanism, fracture surfaces of laminates with different stacking sequences are also studied using scanning electron microscopy (SEM).

  18. Sneutrino mixing

    International Nuclear Information System (INIS)

    Grossman, Y.

    1997-10-01

    In supersymmetric models with nonvanishing Majorana neutrino masses, the sneutrino and antisneutrino mix. The conditions under which this mixing is experimentally observable are studied, and mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are analyzed

  19. Long term carbon dioxide exchange above a mixed forest in the Belgian Ardennes: evaluation of different approaches to deduce total ecosystem respiration from Eddy covariance measurements

    Science.gov (United States)

    Jérôme, Elisabeth; Aubinet, Marc; Heinesch, Bernard

    2010-05-01

    The general aim of this research is to analyze inter annual variability of carbon dioxide (CO2) fluxes exchanged by a mixed forest located at the Vielsalm experimental site in Belgium. At this site, CO2 flux measurements started in 1996 and are still going on. Thirteen complete years of measurements are thus available. Net Ecosystem Exchange (NEE) inter annual variability may be driven by gross primary productivity (GPP) or Total Ecosystem Respiration (TER), which should thus be both quantified. Using flux partitioning methods, TER is deduced from NEE measurements. GPP is then obtained by subtracting TER from NEE. Initially, a robust estimation of TER is required. This work seeks to compare two independent approaches to assess TER in order to quantify the implications on inter-annual variability. The comparison was performed on twelve complete years. TER estimates can be deduced by extrapolating to the whole day NEE measurements taken during selected night or day periods. In both case, the extrapolation is performed by using a respiration response to temperature. The first approach, referred as the night-time approach, consisted in calculating TER using a temperature response function derived from night-time data sets (Reichstein et al., 2005). The second approach, referred as the daytime approach, consisted in assessing TER from the intercept of the NEE/Photosynthetically Photon Flux Density (PPFD) response (Wohlfahrt et al., 2005). For each approach, different modalities were compared: the use of long term (annual) or short term (15 days) data sets for the night-time approach and the use of different types of regression for the daytime approach. In addition, the impact of the temperature choice was studied for each of the approaches. For the night-time approach, main results showed that air temperature sensitivity of ecosystem respiration derived from annual data did not reflect the short-term air temperature sensitivity. Vielsalm is a summer active ecosystem

  20. Thermodynamical, kinetic and structural properties of simple and mixed complexes of zirconium (IV) with the hydroxyl and carbonate ions. Study by potentiometry, Raman spectroscopy and NMR spectroscopy

    International Nuclear Information System (INIS)

    Veyland, A.

    1999-01-01

    Most of zirconium production is used by the nuclear industry for the cladding of nuclear fuels and for the storage of radioactive wastes. The aim of this work is the qualitative and quantitative study of the complexes made by zirconium with the hydroxyl and carbonate ions in order to evaluate the long-term pollution risks linked with the corrosion of confinement containers. The zirconium(IV)/hydroxyl system is studied by proto-metry and follows a protocol which reduces the local over-concentrations of reagent and the precipitation of zirconium hydroxide. In potassium nitrate environment and in a pH range of 1.5 to 3.5, three soluble species are evidenced: Zr(OH) 3 + , Zr 2 (OH) 7 + and Zr(OH) 4 . Their apparent constant of formation and the solubility product of zirconium hydroxide are determined with 4 ionic forces. Using these results, the corresponding thermodynamic constants are calculated by applying the theory of specific interactions. The formation of zirconium (IV) hydroxo-carbonate complexes is evidenced by proto-metry and 17 O and 13 C NMR. The number of carbonates fixed by zirconium varies from 0 to 4. The dialysis indicates that the degree of poly-condensation of species is an inverse function of the number of complex carbonates. The Raman polarized spectra and the 13 C NMR results demonstrate for all complexes the bidentate character of the complexation mode of the carbonates. The dynamical study made by 13 C NMR of the exchange between complexed carbonates of the tetra-carbonate-zirconate ion and free carbonates in solution allows to determine the kinetic constants and the corresponding velocity law. An associative mechanism is proposed, in agreement with the results obtained by mass spectroscopy with electro-spray ionization. These new thermodynamical and kinetic data allow to model the speciation of zirconium in natural waters. (J.S.)

  1. [Effects of selective cutting on the carbon density and net primary productivity of a mixed broadleaved-Korean pine forest in Northeast China].

    Science.gov (United States)

    Liu, Qi; Cai, Hui-Ying; Jin, Guang-Ze

    2013-10-01

    To accurately quantify forest carbon density and net primary productivity (NPP) is of great significance in estimating the role of forest ecosystems in global carbon cycle. By using the forest inventory and allometry approaches, this paper measured the carbon density and NPP of the virgin broadleaved-Korean pine (Pinus koraiensis) forest and of the broadleaved-Korean pine forest after 34 years selective-cutting (the cutting intensity was 30%, and the cutting trees were in large diameter class). The total carbon density of the virgin and selective-cutting broadleaved-Korean pine forests was (397.95 +/- 93.82) and (355.61 +/- 59.37) t C x hm(-2), respectively. In the virgin forest, the carbon density of the vegetation, debris, and soil accounted for 31.0%, 3.1%, and 65.9% of the total carbon pool, respectively; in the selective-cutting forest, the corresponding values were 31.7%, 2.9%, and 65.4%, respectively. No significant differences were observed in the total carbon density and the carbon density of each component between the two forests. The total NPP of the virgin and selective-cutting forests was (36.27 +/- 0.36) and (6.35 +/- 0.70) t C x hm(-2) x a(-1), among which, the NPP of overstory, understory, and fine roots in virgin forest and selective-cutting forest accounted for 60.3%, 2.0%, and 37.7%, and 66.1%, 2.0%, and 31.2%, respectively. No significant differences were observed in the total NPP and the contribution rate of each component between the two forests. However, the ratios of the needle and broadleaf NPPs of the virgin and selective-cutting forests were 47.24:52.76 and 20.48:79.52, respectively, with a significant difference. The results indicated that the carbon density and NPP of the broadleaved-Korean pine forest after 34 years selective-cutting recovered to the levels of the virgin broadleaved-Korean pine forest.

  2. Enhanced adsorption of chromium onto activated carbon by microwave-assisted H{sub 3}PO{sub 4} mixed with Fe/Al/Mn activation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuanyuan [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Yue, Qinyan, E-mail: qyyue58@aliyun.com [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Mao, Yanpeng [School of Energy and Power Engineering, Shandong University, Jinan 250100 (China); Gao, Baoyu; Gao, Yuan; Huang, Lihui [Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China)

    2014-01-30

    Highlights: • FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} were used as the assisted activator to produce carbons. • Doping with MnCl{sub 2} was favorable for the enlargement of activated carbon. • The assisted activator had good performance for holding more fixed carbon. • The maximum adsorption capacities followed the order of AC-Fe > AC-Al > AC-Mn > AC. • The XPS analysis was used to confirm the adsorption/transformation mechanism. -- Abstract: FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} were used as the assisted activation agent in activated carbon preparation by H{sub 3}PO{sub 4} activation using microwave heating method. The physico-chemical properties of activated carbons were investigated by scanning electron microscope (SEM), N{sub 2} adsorption/desorption, Boehm's titration, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). To investigate the adsorption performances of chromium onto these newly developed activated carbons, a batch of experiments were performed under different adsorption conditions: solution pH, initial Cr(VI) ion concentration, contact time and co-existing ions. The results suggested that carbon with MnCl{sub 2} as assisted activation agent displayed the highest BET surface area (1332 m{sup 2}/g) and the highest pore volume (1.060 cm{sup 3}/g). FeCl{sub 3}, AlCl{sub 3} and MnCl{sub 2} had successfully improved Cr(VI) adsorption and activated carbon with FeCl{sub 3} as assisted activation agent exhibited the best uptake capacity. To study the transformation of Cr(VI) in adsorption process, total chromium in the aqueous solution was also recorded. The ratio of the amount of Cr(VI) to Cr(III) on each adsorbent was explained by XPS analysis results. Both the co-existing salts (Na{sub 2}SO{sub 4} and NaNO{sub 3}) demonstrated promoted effects on Cr(VI) removal by four carbons. The pseudo-second-order model and Freundlich equation displayed a good correlation with

  3. Revised (Mixed-Effects) Estimation for Forest Burning Emissions of Gases and Smoke, Fire/Emission Factor Typology, and Potential Remote Sensing Classification of Types for Ozone and Black-Carbon Simulation

    Science.gov (United States)

    Chatfield, Robert B.; Segal Rozenhaimer, M.

    2014-01-01

    We summarize recent progress (a) in correcting biomass burning emissions factors deduced from airborne sampling of forest fire plumes, (b) in understanding the variability in reactivity of the fresh plumes sampled in ARCTAS (2008), DC3 (2012), and SEAC4RS (2013) airborne missions, and (c) in a consequent search for remotely sensed quantities that help classify forest-fire plumes. Particle properties, chemical speciation, and smoke radiative properties are related and mutually informative, as pictures below suggest (slopes of lines of same color are similar). (a) Mixed-effects (random-effects) statistical modeling provides estimates of both emission factors and a reasonable description of carbon-burned simultaneously. Different fire plumes will have very different contributions to volatile organic carbon reactivity; this may help explain differences of free NOx(both gas- and particle-phase), and also of ozone production, that have been noted for forest-fire plumes in California. Our evaluations check or correct emission factors based on sequential measurements (e.g., the Normalized Ratio Enhancement and similar methods). We stress the dangers of methods relying on emission-ratios to CO. (b) This work confirms and extends many reports of great situational variability in emissions factors. VOCs vary in OH reactivity and NOx-binding. Reasons for variability are not only fuel composition, fuel condition, etc., but are confused somewhat by rapid transformation and mixing of emissions. We use "unmixing" (distinct from mixed-effects) statistics and compare briefly to approaches like neural nets. We focus on one particularly intense fire the notorious Yosemite Rim Fire of 2013. In some samples, NOx activity was not so suppressed by binding into nitrates as in other fires. While our fire-typing is evolving and subject to debate, the carbon-burned delta(CO2+CO) estimates that arise from mixed effects models, free of confusion by background-CO2 variation, should provide a

  4. Mixed alcohols production from syngas

    International Nuclear Information System (INIS)

    Stevens, R.R.; Conway, M.M.

    1988-01-01

    A process is described for selectively producing mixed alcohols from synthesis gas comprising contacting a mixture of hydrogen and carbon monoxide with a catalytic amount of a catalyst containing components of (1) a catalytically active metal of molybdenum or tungsten, in free or combined form; (2) a cocatalytic metal or cobalt or nickel in free or combined form; and (3) a Fischer-Tropsch promoter of an alkali or alkaline earth series metal, in free or combined form; the components combined by dry mixing, mixing as a wet paste, wet impregnation, and then sulfided, the catalyst excluding rhodium, ruthenium and copper, at a pressure of at least about 500 psig and under conditions sufficient to form the mixed alcohols in at least 20 percent CO/sub 2/ free carbon selectivity, the mixed alcohols containing a C/sub 1/ to C/sub 2-5/ alcohol weight ratio of less than about 1:1

  5. Free atmospheric CO2 enrichment increased above ground biomass but did not affec symbiotic N2-fixation and soil carbon dynamics in a mixed deciduous stand in Wales

    NARCIS (Netherlands)

    Hoosbeek, M.R.; Lukac, M.; Velthorst, E.J.; Smith, A.R.; Godbold, D.

    2011-01-01

    Through increases in net primary production (NPP), elevated CO2 is hypothesized to increase the amount of plant litter entering the soil. The fate of this extra carbon on the forest floor or in mineral soil is currently not clear. Moreover, increased rates of NPP can be maintained only if forests

  6. Electrochemical characterization of mixed self-assembled films of water-soluble single-walled carbon nanotube-poly(m-aminobenzene sulfonic acid) and Iron(II) tetrasulfophthalocyanine

    CSIR Research Space (South Africa)

    Agboola, BO

    2010-09-01

    Full Text Available The redox activities of water-soluble iron(II) tetrasulfophthalocyanine (FeTSPc) and single-walled carbon nanotube-poly(m-aminobenzene sulfonic acid) (SWCNT-PABS) adsorbed on a gold surface precoated with a self-assembled monolayer (SAM) of 2...

  7. Alternative solution model for the ternary carbonate system CaCO3 - MgCO3 - FeCO3 - II. Calibration of a combined ordering model and mixing model

    Science.gov (United States)

    McSwiggen, P.L.

    1993-01-01

    Earlier attempts at solution models for the ternary carbonate system have been unable to adequately accommodate the cation ordering which occurs in some of the carbonate phases. The carbonate solution model of this study combines a Margules type of interaction model with a Bragg-Williams type of ordering model. The ordering model determines the equilibrium state of order for a crystal, from which the cation distribution within the lattice can be obtained. The interaction model addresses the effect that mixing different cation species within a given cation layer has on the total free energy of the system. An ordering model was derived, based on the Bragg-Williams approach; it is applicable to ternary systems involving three cations substituting on two sites, and contains three ordering energy parameters (WCaMg, WCaFe, and WCaMgFe). The solution model of this study involves six Margules-type interaction parameters (W12, W21, W13, W31, W23, and W32). Values for the two sets of energy parameters were calculated from experimental data and from compositional relationships in natural assemblages. ?? 1993 Springer-Verlag.

  8. Trends in the specific carbon dioxide emissions of the german fuel mix; Entwicklung der spezifischen Kohlendioxid-Emissionen des deutschen Strommix

    Energy Technology Data Exchange (ETDEWEB)

    Machat, Marcus; Werner, Kathrin

    2007-04-15

    The specific emission factor of the German fuel mix is calculated from the direct CO2 emissions of electric power generation and from the net electric power available for end use consumption. The emission factor was reduced between 1990 and 2005, owing to higher efficiencies of modernized power plants and to a bigger share of renewable energy sources. The brochure, published by the Federal Environmental Office, presents trends and diagrams.

  9. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  10. Carbon doped lanthanum aluminate (LaAlO{sub 3}:C) UV thermoluminescent properties synthesized by solid state reaction with three different mixing methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Alves, N., E-mail: neire.radiologia@yahoo.com.br, E-mail: farialo@cdtn.br [Universidade Federal do Estado de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Ferraz, W.B.; Faria, L.O., E-mail: ferrazw@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    In this work we discuss the thermoluminescent (TL) response for LaAlO{sub 3}:C crystals grown by using three different combinations of Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and carbon atoms during the synthesis process. Recently, LaAlO{sub 3} single crystals, co-doped with Ce{sup 3+} and Dy{sup 3+} rare earth trivalent ions and grown under hydrothermal conditions, have been reported to show high thermoluminescent response (TL) when exposed to low levels of ultraviolet radiation (UVR). However, undoped LaAlO{sub 3} synthesized by solid state reaction method from the 1:1 mixture of aluminum and lanthanum oxide under reducing atmosphere revealed to have still higher thermoluminescent sensitivity to UV photon fields than the co-doped with Ce{sup 3+} and Dy{sup 3+}. It is well known that carbon doped aluminum oxide monocrystals have excellent TL and photoluminescent response properties for X-rays, UV and gamma radiation fields. Thus, we conducted three different syntheses of LaAlO{sub 3} by the solid state reaction method, doping the mixture with carbon. The lanthanum aluminate polycrystals were synthesized from the 1:1 mixture of aluminum and lanthanum oxide, adding 0.1wt.% carbon and annealed at 1700°C for two hours in hydrogen atmosphere. The X-ray diffraction analysis revealed the formation of rhombohedral LaAlO{sub 3} crystallographic phase, however a small percentage (15%) of Al{sub 2}O{sub 3} has been also identified. The UV-Vis absorbance spectra were obtained and F and F{sup +}- center were ascribed. The UV irradiations were carried out using a commercial 8W UV lamp. Thermoluminescence measurements were performed at a Harshaw 4500 TL reader. All compositions investigated have shown high TL sensitivity to UVR. (author)

  11. Carbon doped lanthanum aluminate (LaAlO3:C) UV thermoluminescent properties synthesized by solid state reaction with three different mixing methodologies

    International Nuclear Information System (INIS)

    Alves, N.

    2017-01-01

    In this work we discuss the thermoluminescent (TL) response for LaAlO 3 :C crystals grown by using three different combinations of Al 2 O 3 , La 2 O 3 and carbon atoms during the synthesis process. Recently, LaAlO 3 single crystals, co-doped with Ce 3+ and Dy 3+ rare earth trivalent ions and grown under hydrothermal conditions, have been reported to show high thermoluminescent response (TL) when exposed to low levels of ultraviolet radiation (UVR). However, undoped LaAlO 3 synthesized by solid state reaction method from the 1:1 mixture of aluminum and lanthanum oxide under reducing atmosphere revealed to have still higher thermoluminescent sensitivity to UV photon fields than the co-doped with Ce 3+ and Dy 3+ . It is well known that carbon doped aluminum oxide monocrystals have excellent TL and photoluminescent response properties for X-rays, UV and gamma radiation fields. Thus, we conducted three different syntheses of LaAlO 3 by the solid state reaction method, doping the mixture with carbon. The lanthanum aluminate polycrystals were synthesized from the 1:1 mixture of aluminum and lanthanum oxide, adding 0.1wt.% carbon and annealed at 1700°C for two hours in hydrogen atmosphere. The X-ray diffraction analysis revealed the formation of rhombohedral LaAlO 3 crystallographic phase, however a small percentage (15%) of Al 2 O 3 has been also identified. The UV-Vis absorbance spectra were obtained and F and F + - center were ascribed. The UV irradiations were carried out using a commercial 8W UV lamp. Thermoluminescence measurements were performed at a Harshaw 4500 TL reader. All compositions investigated have shown high TL sensitivity to UVR. (author)

  12. A study of the oriented composites with the conductive segregated structure obtained via solid-phase processing of the UHMWPE reactor powder mixed with the carbon nanofillers

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Oleg V. [Moscow Institute of Physics and Technology (State University,) Institutskiy per., Dolgoprudny, Moscow Region, 141700 (Russian Federation); N.S. Enikolopov Institute of Synthetic Polymer Materials of RAS, Profsoyuznaya st., Moscow, 117393 (Russian Federation); Kechek’yan, Alexander S.; Shevchenko, Vitaly G.; Kurkin, Tikhon S.; Golubev, Evgeny K.; Ozerin, Alexander N. [N.S. Enikolopov Institute of Synthetic Polymer Materials of RAS, Profsoyuznaya st., Moscow, 117393 (Russian Federation); Karpushkin, Evgeny A.; Sergeev, Vladimir G. [Moscow State University, Chemical Department, Leninskie Gori, Moscow, 119234 (Russian Federation)

    2016-05-18

    Electrically conductive oriented polymer nano-composites of different compositions, based on the reactor powder of ultra-high-molecular-weight polyethylene (UHMWPE) with a special morphology, filled with particles of nanostructured graphite (NG), multi-walled carbon nanotubes (MWCNTs), and electrically conductive carbon black (CB), were investigated. Polymer composites were obtained via compaction of the mechanical mixture of the polymer and filler powder, followed by uniaxial deformation of the material under homogeneous shear (HS) conditions (all of the processing stages were conducted at room temperature). Resulted composites possess a high tensile strength, high level of the electrical conductivity and low percolation threshold, owing it to the formation of the segregated conductive structure, The influence of the type of nanosized carbon filler, degree of the deformation under HS condition, temperature and etc. on the electrical conductivity and mechanical properties of strengthened conductive composites oriented under homogeneous shear conditions was investigated. Changes in the electrical conductivity of oriented composite materials during reversible “tension–shrinkage” cycles along the orientation axis direction were studied. A theoretical approach, describing the process of transformation of the conductive system as a response on polymer phase deformation and volume change, was proposed, based on the data received from the analysis of the conductivity behavior during the uniaxial deformation and thermal treatment of composites.

  13. Composite photocatalyst containing Eosin Y and multiwalled carbon nanotubes loaded with CuO/NiO: Mixed metal oxide as an active center of H2 evolution from water

    International Nuclear Information System (INIS)

    Kang Shizhao; Chen Lili; Li Xiangqing; Mu Jin

    2012-01-01

    A composite photocatalyst containing Eosin Y as a sensitizer, multiwalled carbon nanotubes as a supporter material or electron transfer channel, and CuO/NiO as an active center of H 2 evolution from water was fabricated and characterized with X-ray photoelectron spectroscopy and transmission electron microscope. Meanwhile, photocatalytic hydrogen evolution from water over this catalyst was explored using triethanolamine as a sacrificial reagent under visible irradiation. A rate of H 2 evolution of approximately 1.0 mmol g -1 h -1 was achieved under optimal conditions. Furthermore, for practical purposes, the photocatalytic hydrogen evolution was studied as a function of content of CuO/NiO, mass ratio of CuO to NiO, pH of solution, concentration of triethanolamine and dosage of Eosin Y, respectively. The results show that mixed metal oxides are a kind of promising active centers of H 2 evolution from water in the photocatalytic system studied.

  14. Composite photocatalyst containing Eosin Y and multiwalled carbon nanotubes loaded with CuO/NiO: Mixed metal oxide as an active center of H2 evolution from water

    Science.gov (United States)

    Kang, Shi-Zhao; Chen, Lili; Li, Xiangqing; Mu, Jin

    2012-06-01

    A composite photocatalyst containing Eosin Y as a sensitizer, multiwalled carbon nanotubes as a supporter material or electron transfer channel, and CuO/NiO as an active center of H2 evolution from water was fabricated and characterized with X-ray photoelectron spectroscopy and transmission electron microscope. Meanwhile, photocatalytic hydrogen evolution from water over this catalyst was explored using triethanolamine as a sacrificial reagent under visible irradiation. A rate of H2 evolution of approximately 1.0 mmol g-1 h-1 was achieved under optimal conditions. Furthermore, for practical purposes, the photocatalytic hydrogen evolution was studied as a function of content of CuO/NiO, mass ratio of CuO to NiO, pH of solution, concentration of triethanolamine and dosage of Eosin Y, respectively. The results show that mixed metal oxides are a kind of promising active centers of H2 evolution from water in the photocatalytic system studied.

  15. New flash mixing

    International Nuclear Information System (INIS)

    Sackmann, I.

    1980-01-01

    It was found that even for stars evolved away from the red giant branch, a new mixing of nucleo-synthesis products from the hydrogen-burning shells into surface layers was possible, from the penetration of the contaminated intershell region with the H- and He-ionization convection zones. This is due to the helium shell flash driving an immense expansion of an inner carbon pocket, namely, by a factor of 12,000 in radius, a drop in density of about 10 12 , and a cooling of inner pockets normally near 10 8 K to 23,000 K. The surface would be enriched in carbon ( 12 C), helium ( 4 He), and s-process elements, but not significantly in nitrogen ( 14 N), oxygen ( 16 O), or the isotope 13 C. This new type of mixing might provide the missing clue for FG Sagittae. Such a mixing had been suggested by the observations of FG Sagittae, but had been unexplainable by theory up to now

  16. Mixed parentage

    DEFF Research Database (Denmark)

    Bang Appel, Helene; Singla, Rashmi

    2016-01-01

    Despite an increase in cross border intimate relationships and children of mixed parentage, there is little mention or scholarship about them in the area of childhood and migrancy in the Nordic countries. The international literature implies historical pathologisation, contestation and current...... of identity formation in the . They position themselves as having an “in-between” identity or “ just Danes” in their every day lives among friends, family, and during leisure activities. Thus a new paradigm is evolving away- from the pathologisation of mixed children, simplified one-sided categories...

  17. Tritium, carbon-14, and iodine-129 as indicators for localized vertical recharge along an anticline in the Columbia River Basalts using a decay-corrected mixing model

    Energy Technology Data Exchange (ETDEWEB)

    Hall, S.H.; Johnson, V.G.; Early, T.O.

    1987-11-01

    Tritium, /sup 14/C, and /sup 129/I in groundwater samples are used to demonstrate vertical recharge and measure flow velocity in the fractured and faulted Umtanum Ridge-Gable Mountain acticline, within the Columbia River Basalts, at a sampling site about 6 mi northeast of the proposed high-level nuclear waste repository at the Hanford Site, Washington State. Mixing model calculations yield an apparent downward migration rate of 15 to 19 ft/yr through a sequence of aquifers in the Wanapum Basalt that range in depth from 698 to 1373 ft. Estimates of the vertical flow rate in the overlying Saddle Mountains Basalt are somewhat higher. Hydrographs from neighboring wells, hydrostatic heads, pump test data, and the chemical composition of groundwater samples from the sampling well are consistent with interaquifer communication. Some hydrologic evidence from aquifers in this region suggests that, in the past, flow may have been upward. This possible reversal of flow may be associated with water table mounding in the unconfined aquifer, caused by waste disposal activities at the Hanford Site since World War II. 17 refs., 12 figs., 3 tabs.

  18. Tritium, carbon-14, and iodine-129 as indicators for localized vertical recharge along an anticline in the Columbia River Basalts using a decay-corrected mixing model

    International Nuclear Information System (INIS)

    Hall, S.H.; Johnson, V.G.; Early, T.O.

    1987-11-01

    Tritium, 14 C, and 129 I in groundwater samples are used to demonstrate vertical recharge and measure flow velocity in the fractured and faulted Umtanum Ridge-Gable Mountain acticline, within the Columbia River Basalts, at a sampling site about 6 mi northeast of the proposed high-level nuclear waste repository at the Hanford Site, Washington State. Mixing model calculations yield an apparent downward migration rate of 15 to 19 ft/yr through a sequence of aquifers in the Wanapum Basalt that range in depth from 698 to 1373 ft. Estimates of the vertical flow rate in the overlying Saddle Mountains Basalt are somewhat higher. Hydrographs from neighboring wells, hydrostatic heads, pump test data, and the chemical composition of groundwater samples from the sampling well are consistent with interaquifer communication. Some hydrologic evidence from aquifers in this region suggests that, in the past, flow may have been upward. This possible reversal of flow may be associated with water table mounding in the unconfined aquifer, caused by waste disposal activities at the Hanford Site since World War II. 17 refs., 12 figs., 3 tabs

  19. Mixed Movements

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2010-01-01

    levels than those related to building, and this exploration is a special challenge and competence implicit artistic development work. The project Mixed Movements generates drawing-material, not primary as representation, but as a performance-based media, making the body being-in-the-media felt and appear...... as possible operational moves....

  20. Lateral Mixing

    Science.gov (United States)

    2014-09-30

    negative (right panel c) and the kinetic energy dissipation is larger than that expected from meterological forcing alone (right panel a). This is...10.1002/grl.50919. Shcherbina, A. et al., 2014, The LatMix Summer Campaign: Submesoscale Stirring in the Upper Ocean., Bull. American Meterological

  1. Free atmospheric CO2 enrichment increased above ground biomass but did not affect symbiotic N2-fixation and soil carbon dynamics in a mixed deciduous stand in Wales

    Directory of Open Access Journals (Sweden)

    A. R. Smith

    2011-02-01

    Full Text Available Through increases in net primary production (NPP, elevated CO2 is hypothesized to increase the amount of plant litter entering the soil. The fate of this extra carbon on the forest floor or in mineral soil is currently not clear. Moreover, increased rates of NPP can be maintained only if forests can escape nitrogen limitation. In a Free atmospheric CO2 Enrichment (FACE experiment near Bangor, Wales, 4 ambient and 4 elevated [CO2] plots were planted with patches of Betula pendula, Alnus glutinosa and Fagus sylvatica on a former arable field. After 4 years, biomass averaged for the 3 species was 5497 (se 270 g m−2 in ambient and 6450 (se 130 g m−2 in elevated [CO2] plots, a significant increase of 17% (P = 0.018. During that time, only a shallow L forest floor litter layer had formed due to intensive bioturbation. Total soil C and N contents increased irrespective of treatment and species as a result of afforestation. We could not detect an additional C sink in the soil, nor were soil C stabilization processes affected by elevated [CO2]. We observed a decrease of leaf N content in Betula and Alnus under elevated [CO2], while the soil C/N ratio decreased regardless of CO2 treatment. The ratio of N taken up from the soil and by N2-fixation in Alnus was not affected by elevated [CO2]. We infer that increased nitrogen use efficiency is the mechanism by which increased NPP is sustained under elevated [CO2] at this site.

  2. effects of mixed of mixed of mixed alkaline earth oxides in potash

    African Journals Online (AJOL)

    eobe

    Si, P) are network formers, and that materials whose. Nigerian ... made by mixing sand (SiO2), potassium carbonates. (K2Co3) .... The edges of the glass were grounded using ..... surface energies of minerals; theoritical estimate for oxides ...

  3. Mixed quantum-classical molecular dynamics study of the hydroxyl stretch in methanol/carbon-tetrachloride mixtures II: excited state hydrogen bonding structure and dynamics, infrared emission spectrum, and excited state lifetime.

    Science.gov (United States)

    Kwac, Kijeong; Geva, Eitan

    2012-03-08

    We present a mixed quantum-classical molecular dynamics study of the hydrogen-bonding structure and dynamics of a vibrationally excited hydroxyl stretch in methanol/carbon-tetrachloride mixtures. The adiabatic Hamiltonian of the quantum-mechanical hydroxyl is diagonalized on-the-fly to obtain the ground and first-excited adiabatic energy levels and wave functions which depend parametrically on the instantaneous configuration of the classical degrees of freedom. The dynamics of the classical degrees of freedom are determined by Hellmann-Feynman forces obtained by taking the expectation value of the force with respect to the ground or excited vibrational wave functions. Polarizable force fields are used which were previously shown to reproduce the experimental infrared absorption spectrum rather well, for different isotopomers and over a wide composition range [Kwac, K.; Geva, E. J. Phys. Chem. B 2011, 115, 9184]. We show that the agreement of the absorption spectra with experiment can be further improved by accounting for the dependence of the dipole moment derivatives on the configuration of the classical degrees of freedom. We find that the propensity of a methanol molecule to form hydrogen bonds increases upon photoexcitation of its hydroxyl stretch, thereby leading to a sizable red-shift of the corresponding emission spectrum relative to the absorption spectrum. Treating the relaxation from the first excited to the ground state as a nonadiabatic process, and calculating its rate within the framework of Fermi's golden rule and the harmonic-Schofield quantum correction factor, we were able to predict a lifetime which is of the same order of magnitude as the experimental value. The experimental dependence of the lifetime on the transition frequency is also reproduced. Nonlinear mapping relations between the hydroxyl transition frequency and bond length in the excited state and the electric field along the hydroxyl bond axis are established. These mapping relations

  4. Mixed hemi/ad-micelles coated magnetic nanoparticles for the entrapment of hemoglobin at the surface of a screen-printed carbon electrode and its direct electrochemistry and electrocatalysis.

    Science.gov (United States)

    Amiri-Aref, Mohaddeseh; Raoof, Jahan Bakhsh; Kiekens, Filip; De Wael, Karolien

    2015-12-15

    An efficient procedure for the physical entrapment of proteins within a biocompatible matrix and their immobilization on electrode surfaces is of utmost importance in the fabrication of biosensors. In this work, the magnetic entrapment of hemoglobin (Hb) at the surface of a screen-printed carbon electrode (SPCE), through mixed hemi/ad-micelles (MHAM) array of positively charged surfactant supported iron oxide magnetic nanoparticles (Mag-NPs), is reported. The Hb/MHAM@Mag-NPs biocomposite is captured at SPCE by a super magnet (Hb/MHAM@Mag-NPs/SPCE). To gain insight in the configuration of the mixed hemi/ad-micelles of CTAB at Mag-NPs, zeta-potential measurements were performed. The entrapment of Hb at MHAM@Mag-NPs was confirmed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FT-IR). Direct electron transfer of the Hb intercalated into the composite film showed a pair of well-defined quasi-reversible redox peak at formal potential of -0.255 V vs. Ag/AgCl corresponding to heme Fe(III)/Fe(II) redox couple. It shows that the MHAM@Mag-NPs composite could increase the adsorption ability for Hb, thus provides a facile direct electron transfer between the Hb and the substrate. The proposed biosensor showed excellent electrocatalytic activity to the H2O2 reduction in the wide concentration range from 5.0 to 300.0 µM obtained by amperometric measurement. The Michaelis-Menten constant (Km) value of Hb at the modified electrode is 55.4 µM, showing its high affinity. Magnetic entrapment offers a promising design for fast, convenient and effective immobilization of protein within a few minutes for determination of the target molecule in low sample volume at disposable cost-effective SPCE. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Parity mixing

    International Nuclear Information System (INIS)

    Adelberger, E.G.

    1975-01-01

    The field of parity mixing in light nuclei bears upon one of the exciting and active problems of physics--the nature of the fundamental weak interaction. It is also a subject where polarization techniques play a very important role. Weak interaction theory is first reviewed to motivate the parity mixing experiments. Two very attractive systems are discussed where the nuclear physics is so beautifully simple that the experimental observation of tiny effects directly measures parity violating (PV) nuclear matrix elements which are quite sensitive to the form of the basic weak interaction. Since the measurement of very small analyzing powers and polarizations may be of general interest to this conference, some discussion is devoted to experimental techniques

  6. A Cambrian mixed carbonate-siliciclastic platform in SW Gondwana: evidence from the Western Sierras Pampeanas (Argentina) and implications for the early Paleozoic paleogeography of the proto-Andean margin

    Science.gov (United States)

    Ramacciotti, Carlos D.; Casquet, César; Baldo, Edgardo G.; Galindo, Carmen; Pankhurst, Robert J.; Verdecchia, Sebastián O.; Rapela, Carlos W.; Fanning, Mark

    2018-05-01

    The Western Sierras Pampeanas (WSP) of Argentina record a protracted geological history from the Mesoproterozoic assembly of the Rodinia supercontinent to the early Paleozoic tectonic evolution of SW Gondwana. Two well-known orogenies took place at the proto-Andean margin of Gondwana in the Cambrian and the Ordovician, i.e., the Pampean (545-520 Ma) and Famatinian (490-440 Ma) orogenies, respectively. Between them, an extensive continental platform was developed, where mixed carbonate-siliciclastic sedimentation occurred. This platform was later involved in the Famatinian orogeny when it underwent penetrative deformation and metamorphism. The platform apparently extended from Patagonia to northwestern Argentina and the Eastern Sierras Pampeanas, and has probable equivalents in SW Africa, Peru, and Bolivia. The WSP record the outer (deepest) part of the platform, where carbonates were deposited in addition to siliciclastic sediments. Detrital zircon U-Pb SHRIMP ages from clastic metasedimentary successions and Sr-isotope compositions of marbles from the WSP suggest depositional ages between ca. 525 and 490 Ma. The detrital zircon age patterns further suggest that clastic sedimentation took place in two stages. The first was sourced mainly from re-working of the underlying Neoproterozoic metasedimentary rocks and the uplifted core of the early Cambrian Pampean orogen, without input from the Paleoproterozoic Río de la Plata craton. Sediments of the second stage resulted from the erosion of the still emerged Pampean belt and the Neoproterozoic Brasiliano orogen in the NE with some contribution from the Río de la Plata craton. An important conclusion is that the WSP basement was already part of SW Gondwana in the early Cambrian, and not part of the exotic Precordillera/Cuyania terrane, as was previously thought.

  7. Apparatus for producing carbon-coated nanoparticles and carbon nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Perry, W. Lee; Weigle, John C.; Phillips, Jonathan

    2015-10-20

    An apparatus for producing carbon-coated nano- or micron-scale particles comprising a container for entraining particles in an aerosol gas, providing an inlet for carbon-containing gas, providing an inlet for plasma gas, a proximate torch for mixing the aerosol gas, the carbon-containing gas, and the plasma gas, bombarding the mixed gases with microwaves, and providing a collection device for gathering the resulting carbon-coated nano- or micron-scale particles. Also disclosed is a method and apparatus for making hollow carbon nano- or micro-scale spheres.

  8. Atributos físicos e carbono orgânico em solo sob cerrado convertido para pastagem e sistema misto / Physical attributes and organic carbon in soil under brazilian Savannah converted to pasture and mixed system

    Directory of Open Access Journals (Sweden)

    Thalita Mendes Resende

    2015-12-01

    Full Text Available The pasture is an important economic activity in the brazilian Savannah. From the 1970s and 1980s, the implementation of the programs to improve the productivity of pastures, was introduced grasses, especially Brachiaria. When handled properly, the pasture is an efficient method to contribute to carbon sequestration and to the mitigation of concentrations of greenhouse gases in the atmosphere, which are dependent to the time of the land-use and the properties of each soil type. The microregion of Uberlandia in Triangulo Mineiro (MG is traditionally linked to the pasture. However, the geological and natural soil conditions and climate are factors that can accelerate soil degradation when pasture is not handled properly. The objective of this article was to compare the changes of soil properties and the incorporation of C in covered areas [1] natural brazilian Savannah, [2] mixed system initially converted to agricultural use and the last 15 years of pasture, and [3] pasture cultivated with 30 years of implantation. The results show the influence of the land use on organic matter dynamics, and evaluate the potential degradation of soil by the activity, management and time of land use.

  9. Composite photocatalyst containing Eosin Y and multiwalled carbon nanotubes loaded with CuO/NiO: Mixed metal oxide as an active center of H{sub 2} evolution from water

    Energy Technology Data Exchange (ETDEWEB)

    Kang Shizhao [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Chen Lili [Key Laboratory for Ultrafine Materials of the Ministry of Education, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Li Xiangqing [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Mu Jin, E-mail: mujin@sit.edu.cn [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China)

    2012-06-01

    A composite photocatalyst containing Eosin Y as a sensitizer, multiwalled carbon nanotubes as a supporter material or electron transfer channel, and CuO/NiO as an active center of H{sub 2} evolution from water was fabricated and characterized with X-ray photoelectron spectroscopy and transmission electron microscope. Meanwhile, photocatalytic hydrogen evolution from water over this catalyst was explored using triethanolamine as a sacrificial reagent under visible irradiation. A rate of H{sub 2} evolution of approximately 1.0 mmol g{sup -1} h{sup -1} was achieved under optimal conditions. Furthermore, for practical purposes, the photocatalytic hydrogen evolution was studied as a function of content of CuO/NiO, mass ratio of CuO to NiO, pH of solution, concentration of triethanolamine and dosage of Eosin Y, respectively. The results show that mixed metal oxides are a kind of promising active centers of H{sub 2} evolution from water in the photocatalytic system studied.

  10. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    Venezky, Dina; Wessells, Stephen

    2010-01-01

    Carbon dioxide is a dangerous volcanic gas. When carbon dioxide seeps from the ground, it normally mixes with the air and dissipates rapidly. However, because carbon dioxide gas is heavier than air, it can collect in snowbanks, depressions, and poorly ventilated enclosures posing a potential danger to people and other living things. In this experiment we show how carbon dioxide gas displaces oxygen as it collects in low-lying areas. When carbon dioxide, created by mixing vinegar and baking soda, is added to a bowl with candles of different heights, the flames are extinguished as if by magic.

  11. Study of the catalytic activity of mixed non-stoichiometric uranium-thorium oxides in carbon monoxide oxidation; Etude de l'activite catalytique des oxydes mixtes d'uranium et de thorium non stoechiometriques dans l'oxydation du monoxyde de carbone

    Energy Technology Data Exchange (ETDEWEB)

    Brau, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-06-01

    The aim of this work has been to study the catalytic properties of non-stoichiometric uranium-thorium oxides having the general formula U{sub x}Th{sub 1-x}O{sub 2+y}, for the oxidation of carbon monoxide. The preparation of pure, homogeneous, isotropic solids having good structural stability and a surface area as high as possible calls for a strict control of the conditions of preparation of these oxides right from the preparation of 'mother salts': the mixed oxalates U{sub x}Th{sub 1-x}(C{sub 2}O{sub 4}){sub 2}, 2H{sub 2}O. A study has been made of their physico-chemical properties (overall and surface chemical constitution, texture, structure, electrical conductivity), as well as of their adsorption properties with respect to gaseous species occurring in the catalytic reaction. This analysis has made it possible to put forward a reaction mechanism based on successive oxidations and reductions of the active surface by the reactants. A study of the reactions kinetics has confirmed the existence of this oxidation-reduction mechanism which only occurs for oxides having a uranium content of above 0.0014. The carbon dioxide produced by the reaction acts as an inhibitor by blocking the sites on which carbon monoxide can be adsorbed. These non-stoichiometric mixed oxides are a particularly clear example of catalysis by oxygen exchange between the solid and the gas phase. (author) [French] Ce travail a pour but l'etude des proprietes catalytiques des oxydes mixtes d'uranium et de thorium non stoechiometriques de formule generale U{sub x}Th{sub 1-x}O{sub 2+y} dans l'oxydation du monoxyde de carbone. L'obtention de solides purs, homogenes, isotropes, de bonne stabilite structurale et d'aire specifique aussi elevee que possible, exige de controler rigoureusement les conditions de preparation de ces oxydes des l'elaboration de leurs 'ascendants': les oxalates mixtes U{sub x}Th{sub 1-x}(C{sub 2}O{sub 4}){sub 2}, 2H{sub 2}O. Leurs proprietes physico-chimiques (composition

  12. Methods of analyzing carbon nanostructures, methods of preparation of analytes from carbon nanostructures, and systems for analyzing carbon nanostructures

    KAUST Repository

    Da Costa, Pedro Miquel Ferreira Joaquim

    2016-09-09

    Provided herein is a method determining the concentration of impurities in a carbon material, comprising: mixing a flux and a carbon material to form a mixture, wherein the carbon material is selected from the group consisting of graphene, carbon nanotubes, fullerene, carbon onions, graphite, carbon fibers, and a combination thereof; heating the mixture using microwave energy to form fused materials; dissolution of the fused materials in an acid mixture; and measuring the concentration of one or more impurities.

  13. Use of the Single Particle Soot Photometer (SP2) as a pre-filter for ice nucleation measurements: effect of particle mixing state and determination of SP2 conditions to fully vaporize refractory black carbon

    Science.gov (United States)

    Schill, Gregory P.; DeMott, Paul J.; Levin, Ezra J. T.; Kreidenweis, Sonia M.

    2018-05-01

    -rich mineral dust, and brown carbon INPs, respectively. The original size distribution and ice nucleation efficiency of all non-rBC proxies were unaffected by the SP2 laser. Furthermore, the ice nucleation efficiencies of all proxies were not affected when externally mixed with rBC. These proxies, however, always show a reduction in ice-nucleating ability when internally mixed with rBC. We end this work with recommendations for users who wish to use the SP2 as a pre-filter to remove large rBC particles from an aerosol stream.

  14. Determination of 222Rn in water by absorption in polydimethylsiloxane mixed with activated carbon and gamma-ray spectrometry: An example application in the radon budget of Paterno submerged sinkhole (Central Italy)

    International Nuclear Information System (INIS)

    Voltaggio, M.; Spadoni, M.

    2013-01-01

    Highlights: ► Polydimethylsiloxane and Activated Carbon were used as passive gas accumulator. ► Water-impermeable properties of PDMS combine with adsorptive properties of AC. ► PDMS–AC accumulators can be used to study 222 Rn in water. ► Measured 222 Rn specific activity in PDMS–AC matches the theoretical results. ► We used PDMS–AC in the radon budget of a submerged sinkhole. - Abstract: Passive gas accumulators made of polydimethylsiloxane (PDMS) mixed with activated C (AC) were studied to measure their efficiency for sampling Rn in water. In this composite the water-impermeable properties of PDMS act synergistically with adsorptive properties of AC, even when the accumulators are immersed in water for many days. A series of tests where cylindrical shaped PDMS–AC disks were exposed to different 222 Rn-enriched waters showed that measured 222 Rn specific activity matches the theoretical results coming from the equation that describes the process of internal diffusion integrated with the Rn decay term. The linear relationship between 222 Rn in water and the accumulation process in PDMS–AC, the influence of temperature and the different sensitivity of the composite and its components were also studied and discussed. The high Rn volumetric enrichment factor in PDMS–AC disks respect to water resulted in about 206: 1, so lowering detection limits for 222 Rn in water to 20 Bq m −3 when the total activity of Rn progeny in disks is measured by high resolution gamma-ray spectrometry. The use of PDMS–AC accumulators was tested at the Paterno submerged sinkhole, in central Italy. This study allowed the production of a detailed synchronous vertical profile of the Rn content in the middle of the lake and to define the Rn balance by assessing the discharge rate of submerged springs and the average residence time of the lake water

  15. Carbon fuel particles used in direct carbon conversion fuel cells

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  16. Carbon Fuel Particles Used in Direct Carbon Conversion Fuel Cells

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2008-10-21

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  17. Convective mixing in helium white dwarfs

    International Nuclear Information System (INIS)

    Vauclair, G.; Fontaine, G.

    1979-01-01

    The conditions under which convective mixing episodes take place between the helium envelopes and the underlying carbon layers in helium-rich white dwarfs are investigated. It is found that, for essentially any value of the initial helium content less than the maximum mass a helium convection zone can have, mixing does occur, and leads, in the vast majority of cases, to an almost pure carbon superficial composition. Mixing products that show only traces of carbon while retaining helium-dominated envelopes are possible only if the initial helium content is quite close to the maximum possible mass of the helium convection zone. In the presence of turbulence, this restriction could be relaxed, however, and the helium-rich lambda4670 stars may possibly be explained in this fashion

  18. Carbon isotopes in mollusk shell carbonates

    Science.gov (United States)

    McConnaughey, Ted A.; Gillikin, David Paul

    2008-10-01

    Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δ13C reflects the local mix of C3 and C4 plants consumed. Shell δ13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell δ13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell δ13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

  19. Promoting effect of active carbons on methanol dehydrogenation on sodium carbonate - hydrogen spillover

    OpenAIRE

    Su, S.; Prairie, M.; Renken, A.

    1993-01-01

    Methanol dehydrogenation to formaldehyde was conducted in a fixed-bed flow reactor with sodium carbonate catalyst mixed with active carbons or transition metals. The additives promoted the reaction rate at 880-970 K without modifying formaldehyde selectivity. This effect increases with increasing carbon content in the carbon-carbonate mixture. Activation energy of methanol conversion is the same for the mixture and the carbonate alone. Temperature-programmed desorption experiments showed that...

  20. Mix for production of heavy concretes

    International Nuclear Information System (INIS)

    Skvara, F.; Halen, S.; Kolar, K.; Novotny, J.; Zadak, Z.; Zezulka, J.

    1981-01-01

    The mix consists of 76 to 99.79 wt.% of cement clay of a specific area of 150 to 3000 m 2 /kg, of heavy aggregate (in a ratio of 1 part of cement clay to more than 1 part of the heavy aggregate) and of 0.1 to 8 wt.% of lignosulphonic acid salt. The mix also contains 0.1 to 8 wt.% of boric acid, 0.01 to 8 wt.% of a carbonate or a hydrogen carbonate of an alkali metal. (H.S.)

  1. Mixed Connective Tissue Disease

    Science.gov (United States)

    Mixed connective tissue disease Overview Mixed connective tissue disease has signs and symptoms of a combination of disorders — primarily lupus, scleroderma and polymyositis. For this reason, mixed connective tissue disease ...

  2. Fluid mixing III

    International Nuclear Information System (INIS)

    Harnby, N.

    1988-01-01

    Covering all aspects of mixing, this work presents research and developments in industrial applications, flow patterns and mixture analysis, mixing of solids into liquids, and mixing of gases into liquids

  3. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  4. Manufacturing sector carbon dioxide emissions in nine OECD countries 1973--87: A Divisia index decomposition to changes in fuel mix, emission coefficients, industry structure, energy intensities, and international structure

    International Nuclear Information System (INIS)

    Torvanger, A.

    1990-11-01

    In this paper the reduction in energy-related manufacturing carbon dioxide emissions for nine OECD countries in the period 1973 to 1987 is analyzed. Carbon dioxide emissions are estimated from energy use data. The emphasis is on carbon dioxide intensities, defined as emissions divided by value added. The overall manufacturing carbon dioxide intensity for the nine OECD countries was reduced by 42% in the period 1973--1987. Five fuels are specified together with six subsectors of manufacturing. Carbon dioxide emissions are estimated from fossil fuel consumption, employing emissions coefficients for gas, oil and solids. In addition, electricity consumption is specified. For electricity use an emission coefficient index is calculated from the shares of fossil fuels, nuclear power and hydro power used to generate electricity, and the efficiency in electricity generation from these energy sources. A Divisia index approach is used to sort out the contribution to reduced carbon dioxide intensity from different components. The major finding is that the main contribution to reduced carbon dioxide intensity is from the general reduction in manufacturing energy intensity, most likely driven by economic growth and increased energy prices, giving incentives to invest in new technology and new industrial processes. There is also a significant contribution from reduced production in the most carbon dioxide intensive subsectors, and a contribution from higher efficiency in electricity generation together with a larger nuclear power share at the expense of oil. 19 refs., 5 figs., 11 tabs

  5. Mixing ratio sensor of alcohol mixed fuel

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Shigeru; Matsubara, Yoshihiro

    1987-08-07

    In order to improve combustion efficiency of an internal combustion engine using gasoline-alcohol mixed fuel and to reduce harmful substance in its exhaust gas, it is necessary to control strictly the air-fuel ratio to be supplied and the ignition timing and change the condition of control depending upon the mixing ratio of the mixed fuel. In order to detect the mixing ratio of the mixed fuel, the above mixing ratio has so far been detected by casting a ray of light to the mixed fuel and utilizing a change of critical angle associated with the change of the composition of the fluid of the mixed fuel. However, in case when a light emitting diode is used for the light source above, two kinds of sensors are further needed. Concerning the two kinds of sensors above, this invention offers a mixing ratio sensor for the alcohol mixed fuel which can abolish a temperature sensor to detect the environmental temperature by making a single compensatory light receiving element deal with the compensation of the amount of light emission of the light emitting element due to the temperature change and the compensation of the critical angle caused by the temperature change. (6 figs)

  6. Continuous mixing of solids

    NARCIS (Netherlands)

    Raouf, M.S.

    1963-01-01

    The most important literature on theoretical aspects of mixing solids was reviewed.

    Only when the mixed materials showed no segregation it was possible to analyse the mixing process quantitatively. In this case the mixture could be described by the 'χ' Square test. Longitudinal mixing could be

  7. European mixed forests

    DEFF Research Database (Denmark)

    Bravo-Oviedo, Andres; Pretzsch, Hans; Ammer, Christian

    2014-01-01

    Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material...... and Methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any...... density in mixed forests, (iii) conversion of monocultures to mixed-species forest and (iv) economic valuation of ecosystem services provided by mixed forests. Research highlights: The definition is considered a high-level one which encompasses previous attempts to define mixed forests. Current fields...

  8. Determination of Carbon-14 in environmental samples by mixing 14CO{sub 2} with a liquid scintillator; Determinacion de carbono-14 en muestras ambientales por incorporacion de 14CO{sub 2} a un centelleador liquido

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. R.; Gomez, V.; Heras, M. C.; Beltran, M. A.

    1990-07-01

    A method for the determination of Carbon-14 (14CO2) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO2) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discussed and compared. The method of collection of atmospheric samples is also described. (Author) 10 refs.

  9. Mixing ratio sensor for alcohol mixed fuel

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Shigeru; Matsubara, Yoshihiro

    1987-08-24

    In order to improve the combustion efficiency of an internal combustion engine using gasoline-alcohol mixed fuel and to reduce harmful substance in its exhaust gas, it is necessary to control strictly the air-fuel ratio to be supplied and the ignition timing. In order to detect the mixing ratio of the mixed fuel, a mixing ratio sensor has so far been proposed to detect the above mixing ratio by casting a ray of light to the mixed fuel and utilizing a change of critical angle associated with the change of the composition of the fluid of the mixed fuel. However, because of the arrangement of its transparent substance in the fuel passage with the sealing material in between, this sensor invited the leakage of the fluid due to deterioration of the sealing material, etc. and its cost became high because of too many parts to be assembled. In view of the above, in order to reduce the number of parts, to lower the cost of parts and the assembling cost and to secure no fluid leakage from the fuel passage, this invention formed the above fuel passage and the above transparent substance both concerning the above mixing ratio sensor in an integrated manner using light transmitting resin. (3 figs)

  10. Mixing-Structure Relationship in Jet-Stirred Reactors

    KAUST Repository

    Ayass, Wassim W.; Nasir, Ehson Fawad; Farooq, Aamir; Sarathy, Mani

    2016-01-01

    of these geometrical parameters on mixing. The mixing was studied at ambient conditions using laser absorption spectroscopy to follow the exit concentration of a tracer gas, carbon dioxide, after a step change in its input flow. The results indicate that the use of a

  11. Method of producing carbon coated nano- and micron-scale particles

    Science.gov (United States)

    Perry, W. Lee; Weigle, John C; Phillips, Jonathan

    2013-12-17

    A method of making carbon-coated nano- or micron-scale particles comprising entraining particles in an aerosol gas, providing a carbon-containing gas, providing a plasma gas, mixing the aerosol gas, the carbon-containing gas, and the plasma gas proximate a torch, bombarding the mixed gases with microwaves, and collecting resulting carbon-coated nano- or micron-scale particles.

  12. Arctic Mixed Layer Dynamics

    National Research Council Canada - National Science Library

    Morison, James

    2003-01-01

    .... Over the years we have sought to understand the heat and mass balance of the mixed layer, marginal ice zone processes, the Arctic internal wave and mixing environment, summer and winter leads, and convection...

  13. SPORT MARKETING MIX STRATEGIES

    OpenAIRE

    Alexandru Lucian MIHAI

    2013-01-01

    This paper presents a brief overview of a significant element of the sport marketing management model called the marketing mix. The marketing mix is crucial because it defines the sport business, and much of the sport marketer’s time is spent on various functions within the marketing mix. The marketing mix is the strategic combination of the product, price, place and promotion elements. These elements are typically called the four Ps of marketing. Decisions and strategies for each are importa...

  14. THE MARKETING MIX OPTIMIZATION

    OpenAIRE

    SABOU FELICIA

    2014-01-01

    The paper presents the marketing mix and the necessity of the marketing mix optimization. In the marketing mix a particularly important issue is to choose the best combination of its variables, this lead to the achievement objectives, in time. Choosing the right marketing mix is possible only by reporting information to some clear benchmarks, these criteria a related to the objective of the company at the time of analyze. The study shows that the companies must give a great importance to opti...

  15. Mixed methods research.

    Science.gov (United States)

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  16. Mixing vane grid spacer

    International Nuclear Information System (INIS)

    Patterson, J.F.; Galbraith, K.P.

    1978-01-01

    An improved mixing vane grid spacer having enhanced flow mixing capability by virtue of mixing vanes being positioned at welded intersecting joints of the spacer wherein each mixing vane has an opening or window formed therein substantially directly over the welded joint to provide improved flow mixing capability is described. Some of the vanes are slotted, depending on their particular location in the spacers. The intersecting joints are welded by initially providing consumable tabs at and within each window, which are consumed during the welding of the spacer joints

  17. Anthropogenic Forcing of Carbonate and Organic Carbon Preservation in Marine Sediments.

    Science.gov (United States)

    Keil, Richard

    2017-01-03

    Carbon preservation in marine sediments, supplemented by that in large lakes, is the primary mechanism that moves carbon from the active surficial carbon cycle to the slower geologic carbon cycle. Preservation rates are low relative to the rates at which carbon moves between surface pools, which has led to the preservation term largely being ignored when evaluating anthropogenic forcing of the global carbon cycle. However, a variety of anthropogenic drivers-including ocean warming, deoxygenation, and acidification, as well as human-induced changes in sediment delivery to the ocean and mixing and irrigation of continental margin sediments-all work to decrease the already small carbon preservation term. These drivers affect the cycling of both carbonate and organic carbon in the ocean. The overall effect of anthropogenic forcing in the modern ocean is to decrease delivery of carbon to sediments, increase sedimentary dissolution and remineralization, and subsequently decrease overall carbon preservation.

  18. MIXED AND MIXING SYSTEMS WORLDWIDE: A PREFACE

    Directory of Open Access Journals (Sweden)

    Seán Patrick Donlan

    2012-09-01

    Full Text Available This issue of the Potchefstroom Electronic Law Journal (South Africa sees thepublication of a selection of articles derived from the Third International Congress ofthe World Society of Mixed Jurisdiction Jurists (WSMJJ. That Congress was held atthe Hebrew University of Jerusalem, Israel in the summer of 2011. It reflected athriving Society consolidating its core scholarship on classical mixed jurisdictions(Israel, Louisiana, the Philippines, Puerto Rico, Quebec, Scotland, and South Africawhile reaching to new horizons (including Cyprus, Hong Kong and Macau, Malta,Nepal, etc. This publication reflects in microcosm the complexity of contemporaryscholarship on mixed and plural legal systems. This complexity is, of course, wellunderstoodby South African jurists whose system is derived both from the dominantEuropean traditions as well as from African customary systems, including both thosethat make up part of the official law of the state as well as those non-state norms thatcontinue to be important in the daily lives of many South Africans.

  19. integrated vertical photobioreactor system for carbon dioxide

    African Journals Online (AJOL)

    Astri Nugroho

    2013-07-02

    Jul 2, 2013 ... efficient system for converting carbon dioxide (CO2) into biomass. The use of ... often been thought to achieve the most efficient mixing and the best ... such process a photobioreactor is designed. Photobioreactor is a device ...

  20. MARKETING MIX THEORETICAL ASPECTS

    OpenAIRE

    Margarita Išoraitė

    2016-01-01

    Aim of article is to analyze marketing mix theoretical aspects. The article discusses that marketing mix is one of the main objectives of the marketing mix elements for setting objectives and marketing budget measures. The importance of each element depends not only on the company and its activities, but also on the competition and time. All marketing elements are interrelated and should be seen in the whole of their actions. Some items may have greater importance than others; it depends main...

  1. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, William K.; Dahlin, David C.; Nilsen, David N.; Walters, Richard P.; Turner, Paul C.

    2000-01-01

    The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation, and the DOE National Energy Technology Laboratory. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. This slurry is reacted with supercritical carbon dioxide (CO2) to produce magnesite (MgCO3). The CO2 is dissolved in water to form carbonic acid (H2CO3), which dissociates to H+ and HCO3 -. The H+ reacts with the mineral, liberating Mg2+ cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO2 pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185?C and a partial pressure of CO2 (PCO2) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction

  2. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, W.K.; Dahlin, D.C.; Nilsen, D.N.; Walters, R.P.; Turner, P.C.

    2000-07-01

    The Albany Research Center (ARC) of the US Department of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite and member (mg{sub 2}SiO{sub 4})], or serpentine [Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}]. This slurry is reacted with supercritical carbon dioxide (CO{sub 2}) to produce magnesite (MgCO{sub 3}). The CO{sub 2} is dissolved in water to form carbonic acid (H{sub 2}CO{sub 3}), which dissociates to H{sup +} and HCO{sub 3}{sup {minus}}. The H{sup +} reacts with the mineral, liberating Mg{sup 2+} cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO{sub 2} pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185 C and a partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction conditions, have achieved roughly 83% conversion of heat treated serpentine

  3. Protocol Fuel Mix reporting

    International Nuclear Information System (INIS)

    2002-07-01

    The protocol in this document describes a method for an Electricity Distribution Company (EDC) to account for the fuel mix of electricity that it delivers to its customers, based on the best available information. Own production, purchase and sale of electricity, and certificates trading are taken into account. In chapter 2 the actual protocol is outlined. In the appendixes additional (supporting) information is given: (A) Dutch Standard Fuel Mix, 2000; (B) Calculation of the Dutch Standard fuel mix; (C) Procedures to estimate and benchmark the fuel mix; (D) Quality management; (E) External verification; (F) Recommendation for further development of the protocol; (G) Reporting examples

  4. Mixed waste management options

    International Nuclear Information System (INIS)

    Owens, C.B.; Kirner, N.P.

    1992-01-01

    Currently, limited storage and treatment capacity exists for commercial mixed waste streams. No commercial mixed waste disposal is available, and it has been estimated that if and when commercial mixed waste disposal becomes available, the costs will be high. If high disposal fees are imposed, generators may be willing to apply extraordinary treatment or regulatory approaches to properly dispose of their mixed waste. This paper explores the feasibility of several waste management scenarios and management options. Existing data on commercially generated mixed waste streams are used to identify the realm of mixed waste known to be generated. Each waste stream is evaluated from both a regulatory and technical perspective in order to convert the waste into a strictly low-level radioactive or a hazardous waste. Alternative regulatory approaches evaluated in this paper include a delisting petition) no migration petition) and a treatability variance. For each waste stream, potentially available treatment options are identified that could lead to these variances. Waste minimization methodology and storage for decay are also considered. Economic feasibility of each option is discussed broadly. Another option for mixed waste management that is being explored is the feasibility of Department of Energy (DOE) accepting commercial mixed waste for treatment, storage, and disposal. A study has been completed that analyzes DOE treatment capacity in comparison with commercial mixed waste streams. (author)

  5. Mixed Waste Management Facility

    International Nuclear Information System (INIS)

    Brummond, W.; Celeste, J.; Steenhoven, J.

    1993-08-01

    The DOE has developed a National Mixed Waste Strategic Plan which calls for the construction of 2 to 9 mixed waste treatment centers in the Complex in the near future. LLNL is working to establish an integrated mixed waste technology development and demonstration system facility, the Mixed Waste Management Facility (MWMF), to support the DOE National Mixed Waste Strategic Plan. The MWMF will develop, demonstrate, test, and evaluate incinerator-alternatives which will comply with regulations governing the treatment and disposal of organic mixed wastes. LLNL will provide the DOE with engineering data for design and operation of new technologies which can be implemented in their mixed waste treatment centers. MWMF will operate under real production plant conditions and process samples of real LLNL mixed waste. In addition to the destruction of organic mixed wastes, the development and demonstration will include waste feed preparation, material transport systems, aqueous treatment, off-gas treatment, and final forms, thus making it an integrated ''cradle to grave'' demonstration. Technologies from offsite as well as LLNL's will be tested and evaluated when they are ready for a pilot scale demonstration, according to the needs of the DOE

  6. Mixing of solids in different mixing devices

    Indian Academy of Sciences (India)

    INGRID BAUMAN, DUŠKA ´CURI ´C and MATIJA BOBAN ... whose main cause is the difference in particle size, density shape and resilience. ..... Gyebis J, Katai F 1990 Determination and randomness in mixing of particulate solids, Chem.

  7. Experimental study of a RF plasma source with helicon configuration in the mix Ar/H_2. Application to the chemical etching of carbon materials surfaces in the framework of the plasma-wall interactions studies of ITER's divertor

    International Nuclear Information System (INIS)

    Bieber, T.

    2012-01-01

    The issue of the interaction wall-plasma is important in thermonuclear devices. The purpose of this work is to design a very low pressure atomic plasma source in order to study chemical etching of carbon surfaces in the same conditions as edge plasma in tokamaks. The experimental work has consisted in 2 stages: first, the characterisation of the new helicon configuration reactor developed for this research and secondly the atomic hydrogen source used for the chemical etching. The first chapter recalls what thermonuclear fusion is. The helicon configuration reactor as well as its diagnostics (optical emission spectroscopy, laser induced fluorescence - LIF, and Langmuir probe) are described in the second chapter. The third chapter deals with the different coupling modes (RF power and plasma) identified in pure argon plasmas and how they are obtained by setting experimental parameters such as injected RF power, magnetic fields or pressure. The fourth chapter is dedicated to the study of the difference in behavior between the electronic density and the relative density of metastable Ar"+ ions. The last chapter presents the results in terms of mass losses of the carbon material surfaces obtained with the atomic hydrogen source. (A.C.)

  8. Characteristics, stratigraphic architecture, and time framework of multi-order mixed siliciclastic and carbonate depositional sequences, outcropping Cisco Group (Late Pennsylvanian and Early Permian), Eastern Shelf, north-central Texas, USA

    Science.gov (United States)

    Yang, Wan; Kominz, Michelle A.

    2003-01-01

    The Cisco Group on the Eastern Shelf of the Midland Basin is composed of fluvial, deltaic, shelf, shelf-margin, and slope-to-basin carbonate and siliciclastic rocks. Sedimentologic and stratigraphic analyses of 181 meter-to-decimeter-scale depositional sequences exposed in the up-dip shelf indicated that the siliciclastic and carbonate parasequences in the transgressive systems tracts (TST) are thin and upward deepening, whereas those in highstand systems tracts (HST) are thick and upward shallowing. The sequences can be subdivided into five types on the basis of principal lithofacies, and exhibit variable magnitude of facies shift corresponding to variable extents of marine transgression and regression on the shelf. The sequence stacking patterns and their regional persistence suggest a three-level sequence hierarchy controlled by eustasy, whereas local and regional changes in lithology, thickness, and sequence type, magnitude, and absence were controlled by interplay of eustasy, differential shelf subsidence, depositional topography, and pattern of siliciclastic supply. The outcropping Cisco Group is highly incomplete with an estimated 6-11% stratigraphic completeness. The average duration of deposition of the major (third-order) sequences is estimated as 67-102 ka on the up-dip shelf and increases down dip, while the average duration of the major sequence boundaries (SB) is estimated as 831-1066 ka and decreases down dip. The nondepositional and erosional hiatus on the up-dip shelf was represented by lowstand deltaic systems in the basin and slope.

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

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

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

  10. Skeletal carbonate on the continental shelf: SEM evidence of early diagenetic alteration of the 1% of shells that persist for millennia in the mixed layer and thus enter the permanent record

    Science.gov (United States)

    Kidwell, S. M.; Tomasovych, A.; Alexander, C. R., Jr.

    2016-02-01

    An extensive program of dating aragonitic bivalve shells from the mixed-layer of the southern California shelf using AMS-calibrated amino-acid racemization has revealed strongly right-skewed shell-age frequency distributions: the median age of shells (2-7 mm) is quite young, generally <100 y, but the distribution includes a long tail of old shells 2550 to 11,900 y (Tomasovych et al. 2014 Geology). Modeling indicates that shells experience a high initial disintegration rate λ1 ( decadal half-lives) but shift abruptly, within the first 500 y, to a 100-fold lower disintegration rate λ2 ( millennial half-lives) at sequestration rate τ (burial and/or diagenetic stabilization). Although this drop permits the accrual of a long tail of very old shells, <1% of shells survive the first phase. In the fossil record, proxy geochemical and ecological data are extracted from such survivors, and so understanding the mechanisms of shell persistence in the mixed layer is critical to confident paleoenvironmental inference. We have hypothesized that permanent diagenetic stabilization within the mixed layer, which Pb-210 shows is 4-17 cm thick on this shelf, may be necessary to ensure that shells do not revert to λ1 after temporary sequestration in pockets of favorable porewater. Our new SEM of shells of known, AMS-calibrated post-mortem age shows that macroscopic (10x) variation in shell color and luster is related to (1) loss of inter-crystallite organic matrix, probably by microbial maceration (chalky phase; within a few years post-mortem), (2) development of a surficial skim-coat of large, complexly interdigitating "jigsaw" crystallites, consistent with Ostwald ripening (shells re-acquire luster; patches develop within 10s y and coalesce over 100s to k y), and (3) development of a consistently fine-grained, apparently penetrative fabric, suggesting replacement of the original microstructure by a novel authigenic phase (gray stain; shells ≥ 5 ka). Electron back

  11. Music Mixing Surface

    DEFF Research Database (Denmark)

    Gelineck, Steven; Büchert, Morten; Andersen, Jesper

    2013-01-01

    This paper presents a multi-touch based interface for mixing music. The goal of the interface is to provide users with a more intuitive control of the music mix by implementing the so-called stage metaphor control scheme, which is especially suitable for multi-touch surfaces. Specifically, we...

  12. Warm Mix Asphalt

    Science.gov (United States)

    2009-04-17

    State of Alaska State of Alaska - Warm Mix Project Warm Mix Project: Location - Petersburg, Alaska which is Petersburg, Alaska which is located in the heart of Southeast Alaska located in the heart of Southeast Alaska's Inside Passage at the tip of M...

  13. The Mixed language Debate

    DEFF Research Database (Denmark)

    A range of views on mixed languages and their connections to phenomena such as secret languages, massive borrowing, codeswitching and codemixing, and thier origin.......A range of views on mixed languages and their connections to phenomena such as secret languages, massive borrowing, codeswitching and codemixing, and thier origin....

  14. Soil respiration response to prescribed burning and thinning in mixed-conifer and hardwood forests

    Science.gov (United States)

    Amy Concilio; Siyan Ma; Qinglin Li; James LeMoine; Jiquan Chen; Malcolm North; Daryl Moorhead; Randy Jensen

    2005-01-01

    The effects of management on soil carbon efflux in different ecosystems are still largely unknown yet crucial to both our understanding and management of global carbon flux. To compare the effects of common forest management practices on soil carbon cycling, we measured soil respiration rate (SRR) in a mixed-conifer and hardwood forest that had undergone various...

  15. Passive Mixing inside Microdroplets

    Directory of Open Access Journals (Sweden)

    Chengmin Chen

    2018-04-01

    Full Text Available Droplet-based micromixers are essential units in many microfluidic devices for widespread applications, such as diagnostics and synthesis. The mixers can be either passive or active. When compared to active methods, the passive mixer is widely used because it does not require extra energy input apart from the pump drive. In recent years, several passive droplet-based mixers were developed, where mixing was characterized by both experiments and simulation. A unified physical understanding of both experimental processes and simulation models is beneficial for effectively developing new and efficient mixing techniques. This review covers the state-of-the-art passive droplet-based micromixers in microfluidics, which mainly focuses on three aspects: (1 Mixing parameters and analysis method; (2 Typical mixing element designs and the mixing characters in experiments; and, (3 Comprehensive introduction of numerical models used in microfluidic flow and diffusion.

  16. ADVANCED MIXING MODELS

    International Nuclear Information System (INIS)

    Lee, S; Richard Dimenna, R; David Tamburello, D

    2008-01-01

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four dual-nozzle jet mixers located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The work described in this report establishes the basis for further development of the theory leading to the identified mixing indicators, the benchmark analyses demonstrating their consistency with widely accepted correlations, and the application of those indicators to SRS waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. If shorter mixing times can be shown to support Defense Waste Processing Facility (DWPF) or other feed requirements, longer pump lifetimes can be achieved with associated operational cost and

  17. ADVANCED MIXING MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Richard Dimenna, R; David Tamburello, D

    2008-11-13

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four dual-nozzle jet mixers located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The work described in this report establishes the basis for further development of the theory leading to the identified mixing indicators, the benchmark analyses demonstrating their consistency with widely accepted correlations, and the application of those indicators to SRS waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. If shorter mixing times can be shown to support Defense Waste Processing Facility (DWPF) or other feed requirements, longer pump lifetimes can be achieved with associated operational cost and

  18. Preparation, physical-chemical characterisation and cytocompatibility of calcium carbonate cements

    OpenAIRE

    Combes, Christèle; Miao, Baoji; Bareille, Reine; Rey, Christian

    2006-01-01

    The feasibility of calcium carbonate cements involving the recrystallisation of metastable calcium carbonate varieties has been demonstrated. Calcium carbonate cement compositions presented in this paper can be prepared straightforwardly by simply mixing water (liquid phase) with two calcium carbonate phases (solid phase) which can be easily obtained by precipitation. An original cement composition was obtained by mixing amorphous calcium carbonate and vaterite with an aqueous medium. The cem...

  19. Mercury emissions control technologies for mixed waste thermal treatment

    International Nuclear Information System (INIS)

    Chambers, A.; Knecht, M.; Soelberg, N.; Eaton, D.

    1997-01-01

    EPA has identified wet scrubbing at low mercury feedrates, as well as carbon adsorption via carbon injection into the offgas or via flow through fixed carbon beds, as control technologies that can be used to meet the proposed Maximum Achievable Control Technology (MACT) rule limit for mercury emissions from hazardous waste incinerators. DOE is currently funding demonstrations of gold amalgamation that may also control mercury to the desired levels. Performance data from a variety of sources was reviewed to determine ranges of achievable mercury control. Preliminary costs were estimated for using these technologies to control mercury emissions from mixed waste incineration. Mercury emissions control for mixed waste incineration may need to be more efficient than for incineration of other hazardous wastes because of higher mercury concentrations in some mixed waste streams. However, mercury control performance data for wet scrubbing and carbon adsorption is highly variable. More information is needed to demonstrate control efficiencies that are achievable under various design and operating conditions for wet scrubbing, carbon adsorption, and gold amalgamation technologies. Given certain assumptions made in this study, capital costs, operating costs, and lifecycle costs for carbon injection, carbon beds, and gold amalgamation generally vary for different assumed mercury feedrates and for different offgas flowrates. Assuming that these technologies can in fact provide the necessary mercury control performance, each of these technologies may be less costly than the others for certain mercury feedrates and the offgas flowrates

  20. ADVANCED MIXING MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Dimenna, R; Tamburello, D

    2011-02-14

    The process of recovering and processing High Level Waste (HLW) the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four mixers (pumps) located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are typically set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The focus of the present work is to establish mixing criteria applicable to miscible fluids, with an ultimate goal of addressing waste processing in HLW tanks at SRS and quantifying the mixing time required to suspend sludge particles with the submersible jet pump. A single-phase computational fluid dynamics (CFD) approach was taken for the analysis of jet flow patterns with an emphasis on the velocity decay and the turbulent flow evolution for the farfield region from the pump. Literature results for a turbulent jet flow are reviewed, since the decay of the axial jet velocity and the evolution of the jet flow patterns are important phenomena affecting sludge suspension and mixing operations. The work described in this report suggests a basis for further development of the theory leading to the identified mixing indicators, with benchmark analyses demonstrating their consistency with widely accepted correlations. Although the indicators are somewhat generic in nature, they are applied to Savannah River Site (SRS) waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in

  1. Highly thermal conductive carbon fiber/boron carbide composite material

    International Nuclear Information System (INIS)

    Chiba, Akio; Suzuki, Yasutaka; Goto, Sumitaka; Saito, Yukio; Jinbo, Ryutaro; Ogiwara, Norio; Saido, Masahiro.

    1996-01-01

    In a composite member for use in walls of a thermonuclear reactor, if carbon fibers and boron carbide are mixed, since they are brought into contact with each other directly, boron is reacted with the carbon fibers to form boron carbide to lower thermal conductivity of the carbon fibers. Then, in the present invention, graphite or amorphous carbon is filled between the carbon fibers to provide a fiber bundle of not less than 500 carbon fibers. Further, the surface of the fiber bundle is coated with graphite or amorphous carbon to suppress diffusion or solid solubilization of boron to carbon fibers or reaction of them. Then, lowering of thermal conductivity of the carbon fibers is prevented, as well as the mixing amount of the carbon fiber bundles with boron carbide, a sintering temperature and orientation of carbon fiber bundles are optimized to provide a highly thermal conductive carbon fiber/boron carbide composite material. In addition, carbide or boride type short fibers, spherical graphite, and amorphous carbon are mixed in the boron carbide to prevent development of cracks. Diffusion or solid solubilization of boron to carbon fibers is reduced or reaction of them if the carbon fibers are bundled. (N.H.)

  2. THE MARKETING MIX OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    SABOU FELICIA

    2014-02-01

    Full Text Available ing mix a particularly important issue is to choose the best combination of its variables, this lead to the achievement objectives, in time. Choosing the right marketing mix is possible only by reporting information to some clear benchmarks, these criteria a related to the objective of the company at the time of analyze. The study shows that the companies must give a great importance to optimize the marketing mix, because of how its combines and integrates company policies relating to the product, price, distribution and promotion, depends the success or the failure on its market. The practice has shown that if an element of the marketing mix is wrong implemented, marketing strategies and programs do not achieve their objectives, and the company can not generate the expected profit. To optimize the marketing mix, companies should consider the following issues: the resources (materials, financial and human, which will be properly allocated to all the elements of the marketing mix, the specific marketing tools and the relationship of interdependence of all the methods and tools used to optimize the marketing mix.

  3. The mixing of fluids

    International Nuclear Information System (INIS)

    Ottino, J.M.

    1989-01-01

    What do the eruption of Krakatau, the manufacture of puff pastry and the brightness of stars have in common? Each involves some aspect of mixing. Mixing also plays a critical role in modern technology. Chemical engineers rely on mixing to ensure that substances react properly, to produce polymer blends that exhibit unique properties and to disperse drag-reducing agents in pipelines. Yet in spite of its of its ubiquity in nature and industry, mixing is only imperfectly under-stood. Indeed, investigators cannot even settle on a common terminology: mixing is often referred to as stirring by oceanographers and geophysicists, as blending by polymer engineers and as agitation by process engineers. Regardless of what the process is called, there is little doubt that it is exceedingly complex and is found in a great variety of systems. In constructing a theory of fluid mixing, for example, one has to take into account fluids that can be miscible or partially miscible and reactive or inert, and flows that are slow and orderly or very fast and turbulent. It is therefore not surprising that no single theory can explain all aspect of mixing in fluids and that straightforward computations usually fail to capture all the important details. Still, both physical experiments and computer simulations can provide insight into the mixing process. Over the past several years the authors and his colleague have taken both approaches in an effort to increase understanding of various aspect of the process-particularly of mixing involving slow flows and viscous fluids such as oils

  4. Evaluation of carbon storage in soil and plant biomass of primary ...

    African Journals Online (AJOL)

    Carbon sequestration in a forest ecosystem is an important determinant of the local and regional carbon stock. This study monitored forest types and carbon storage in both biomass and soil within primary mixed deciduous forests (PMDF) and secondary mixed deciduous forests (SMDF). One study plot measuring 50 x 50 m ...

  5. Modelling (vapour + liquid) and (vapour + liquid + liquid) equilibria of {water (H2O) + methanol (MeOH) + dimethyl ether (DME) + carbon dioxide (CO2)} quaternary system using the Peng-Robinson EoS with Wong-Sandler mixing rule

    International Nuclear Information System (INIS)

    Ye Kongmeng; Freund, Hannsjoerg; Sundmacher, Kai

    2011-01-01

    Highlights: → Phase behaviour modelling of H 2 O-MeOH-DME under pressurized CO 2 (anti-solvent) using PRWS. → PRWS-UNIFAC-PSRK has better performance than PRWS-UNIFAC-Lby in general. → Reliable to extend the VLE and VLLE phase behaviour from binary to multicomponent systems. → Successful prediction of the VLE and VLLE of binary, ternary, and quaternary systems. → Potential to apply the model for designing new DME separation process. - Abstract: The (vapour + liquid) equilibria (VLE) and (vapour + liquid + liquid) equilibria (VLLE) binary data from literature were correlated using the Peng-Robinson (PR) equation of state (EoS) with the Wong-Sandler mixing rule (WS). Two group contribution activity models were used in the PRWS: UNIFAC-PSRK and UNIFAC-Lby. The systems were successfully extrapolated from the binary systems to ternary and quaternary systems. Results indicate that the PRWS-UNIFAC-PSRK generally displays a better performance than the PRWS-UNIFAC-Lby.

  6. Guidelines for mixed waste minimization

    International Nuclear Information System (INIS)

    Owens, C.

    1992-02-01

    Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization

  7. The research of a method for determination of total carbon, combination carbon and free carbon in beryllium metal

    International Nuclear Information System (INIS)

    Yang Xingzhong; Zhu Xiaohong

    1996-02-01

    A method for determination of total carbon, combination carbon and free carbon in beryllium metal with LECO CS-344 carbon/sulphur determinant has been studied. Tungsten-copper mixed pellets are used as flux to the determination of total carbon. Ratio of weight of the flux to the sample is greater than 20:1. Good analytical results are got. By this method the relative standard deviation is <10% when the content of total carbon in the range of 0.050%∼0.080% in beryllium. A standard steel sample of carbon is added into beryllium, the recoveries are 94%∼106%. For determination of free carbon, the sample are decomposed with 3 mol/L HCl, filtered and followed determination. By this method the relative standard deviation is ≤10% when the content of free carbon in the range of 0.006%∼0.020% in beryllium. the balance of total carbon and free carbon is equal to combination carbon. The method is used to determine the sample of content of total carbon in the range of 0.050%∼1.00%, free carbon in the range of 0.006%∼0.500% in metal beryllium. (6 refs., 1 fig., 13 tabs.)

  8. Idealized mixing impacts

    International Nuclear Information System (INIS)

    Peterson, R.A.

    1999-01-01

    The dispersion of tetraphenylborate in continuous stirred tank reactors plays a significant role in the utility achieved from the tetraphenylborate. Investigating idealized mixing of the materials can illuminate how this dispersion occurs

  9. SPORT MARKETING MIX STRATEGIES

    Directory of Open Access Journals (Sweden)

    Alexandru Lucian MIHAI

    2013-06-01

    Full Text Available This paper presents a brief overview of a significant element of the sport marketing management model called the marketing mix. The marketing mix is crucial because it defines the sport business, and much of the sport marketer’s time is spent on various functions within the marketing mix. The marketing mix is the strategic combination of the product, price, place and promotion elements. These elements are typically called the four Ps of marketing. Decisions and strategies for each are important for the marketer. Information for making educated decisions involving the four Ps comes from the marketing research involving primarily the four Cs - consumer, competitor, company and climate. A critical decision and one of the greatest challenges for the sport business is how to strategically combine the four Ps to best satisfy the consumer, meet company objectives, enhance market position, and enhance competitive advantages.

  10. Balanço de carbono e nutrientes em plantio puro e misto de espécies florestais nativas no sudeste da Bahia Carbon and nutrient balance in pure and mixed stands of native tree species in Southeastern Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Antonio Carlos da Gama-Rodrigues

    2008-06-01

    plantation systems of forest species native in the Atlantic Forest. The plantation systems consisted of 22 year-old mixed stand and pure stands of six hardwood species (Peltogyne angustiflora, Centrolobium robustum, Arapatiella psilophylla, Sclerolobium chrysophyllum, Cordia trichotoma, Macrolobium latifolium native to the southeastern region of Bahia, Brazil, that were evaluated from August 1994 through July 1995. As references, the study included a natural forest and a 40-year-old, naturally regenerating secondary forest. Total stocks of carbon and nutrients in the soil-plant-litter systems varied among species in pure stands, but the capacity of accumulation of these elements in the mixed stands was greater than in the pure stands. The intensity of biochemical cycling of all studied nutrients in mixed stands was greater than the average values observed for pure stands. A similar result was obtained for biogeochemical cycling, with exception of Ca. The C, P, K balances were negative for all forest species, whereas the N balance was positive. The Ca balance was only positive in the pure stand of Sclerolobium chrysophyllum, and the Mg balance was negative only in the pure stands of Centrolobium robustum and Macrolobium latifolium. The most negative balances were found for P, K and Ca. The mean carbon and nutrient balances in the mixed-tree stands were similar to those in pure stands. The biochemical and biogeochemical cycling in mixed-tree stands was more efficient and the balance more equilibrated than in pure stands. Therefore, mixed-tree stands proved to be the best plantation system, in view of the more efficient biochemical and biogeochemical cycling and better balanced of carbon and nutrients.

  11. MARKETING MIX IN SPORT

    OpenAIRE

    Srećko Novaković; Slobodan Živkucin

    2011-01-01

    Marketing mix'' along the term of life cycle has robbed the trademark for the conception of marketing and the market direction of company, corporations and institutions. Essence marketing-mixa is in the simultaneous determining of the target market group of consumer (the buyer) or stays the public and specially prepared and the coordinated impact of elements mixa, and this is the product, price, distributions and graduation ceremonies. Given that is mix combinations of verified variables, com...

  12. Mixed Reality Systems

    OpenAIRE

    Dieter Müller

    2009-01-01

    Currently one of the most challenging aspects of human computer interaction design is the integration of physical and digital worlds in a single environment. This fusion involves the development of "Mixed Reality Systems”, including various technologies from the domains of augmented and virtual reality. In this paper I will present related concepts and discuss lessons learned from our own research and prototype development. Our recent work involves the use of mixed reality (as opposed to ‘pur...

  13. Features of neutrino mixing

    Science.gov (United States)

    Chiu, S. H.; Kuo, T. K.

    2018-03-01

    The elements (squared) of the neutrino mixing matrix are found to satisfy, as functions of the induced mass, a set of differential equations. They show clearly the dominance of pole terms when the neutrino masses "cross." Using the known vacuum mixing parameters as initial conditions, it is found that these equations have very good approximate solutions, for all values of the induced mass. The results are applicable to long baseline experiments.

  14. Carbon/carbon composite materials

    International Nuclear Information System (INIS)

    Thebault, J.; Orly, P.

    2006-01-01

    Carbon/carbon composites are singular materials from their components, their manufacturing process as well as their characteristics. This paper gives a global overview of these particularities and applications which make them now daily used composites. (authors)

  15. Hydraulic jett mixing

    International Nuclear Information System (INIS)

    Ackerman, J.R.

    1989-01-01

    Efficient mixing of reactants into a waste stream has always been a problem in that there has been no mixer capable of combining all the elements of enhanced mixing into a single piece of equipment. Through the development of a mixing system for the mining industry to treat acid mine water containing heavy metals, a versatile new hydraulic jetting static mixer has been developed that has no moving parts and a clean bore with no internal components. This paper reports that the main goal of the development of the hydraulic jett mixer was to reduce the size of the tankage required for an acid mine drainage (AMD) treatment plant through development of a static mixing device that could coincidentally aerate the treatment flow. This process equipment being developed would simultaneously adjust the pH and oxidize the metals allowing formation of the hydroxide sludges required for sedimentation and removal of the metals from the treatment stream. In effect, the device eliminates two reaction tanks, the neutralization/mixing tank and the aeration tank

  16. Charm mixing at LHCb

    CERN Document Server

    Di Canto, Angelo

    2013-01-01

    We report a measurement of the time-dependent ratio of $D^0\\to K^+\\pi^-$ to $D^0\\to K^-\\pi^+$ decay rates in $D^{*+}$-tagged events using 1.0\\,fb$^{-1}$ of integrated luminosity recorded by the LHCb experiment. We measure the mixing parameters $x'^2=(-0.9\\pm1.3)\\times10^{-4}$, $y'=(7.2\\pm2.4)\\times10^{-3}$ and the ratio of doubly-Cabibbo-suppressed to Cabibbo-favored decay rates $R_D=(3.52\\pm0.15)\\times10^{-3}$. The result excludes the no-mixing hypothesis with a probability corresponding to 9.1 standard deviations and represents the first observation of charm mixing from a single measurement

  17. Mixed waste: Proceedings

    International Nuclear Information System (INIS)

    Moghissi, A.A.; Blauvelt, R.K.; Benda, G.A.; Rothermich, N.E.

    1993-01-01

    This volume contains the peer-reviewed and edited versions of papers submitted for presentation a the Second International Mixed Waste Symposium. Following the tradition of the First International Mixed Waste Symposium, these proceedings were prepared in advance of the meeting for distribution to participants. The symposium was organized by the Mixed Waste Committee of the American Society of Mechanical Engineers. The topics discussed at the symposium include: stabilization technologies, alternative treatment technologies, regulatory issues, vitrification technologies, characterization of wastes, thermal technologies, laboratory and analytical issues, waste storage and disposal, organic treatment technologies, waste minimization, packaging and transportation, treatment of mercury contaminated wastes and bioprocessing, and environmental restoration. Individual abstracts are catalogued separately for the data base

  18. Mixed waste: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Moghissi, A.A.; Blauvelt, R.K.; Benda, G.A.; Rothermich, N.E. [eds.] [Temple Univ., Philadelphia, PA (United States). Dept. of Environmental Safety and Health

    1993-12-31

    This volume contains the peer-reviewed and edited versions of papers submitted for presentation a the Second International Mixed Waste Symposium. Following the tradition of the First International Mixed Waste Symposium, these proceedings were prepared in advance of the meeting for distribution to participants. The symposium was organized by the Mixed Waste Committee of the American Society of Mechanical Engineers. The topics discussed at the symposium include: stabilization technologies, alternative treatment technologies, regulatory issues, vitrification technologies, characterization of wastes, thermal technologies, laboratory and analytical issues, waste storage and disposal, organic treatment technologies, waste minimization, packaging and transportation, treatment of mercury contaminated wastes and bioprocessing, and environmental restoration. Individual abstracts are catalogued separately for the data base.

  19. Bimaximal fermion mixing from the quark and leptonic mixing matrices

    International Nuclear Information System (INIS)

    Ohlsson, Tommy

    2005-01-01

    In this Letter, we show how the mixing angles of the standard parameterization add when multiplying the quark and leptonic mixing matrices, i.e., we derive explicit sum rules for the quark and leptonic mixing angles. In this connection, we also discuss other recently proposed sum rules for the mixing angles assuming bimaximal fermion mixing. In addition, we find that the present experimental and phenomenological data of the mixing angles naturally fulfill our sum rules, and thus, give rise to bilarge or bimaximal fermion mixing

  20. Ageing of Dry Cement Mixes for Finishing Purposes

    Directory of Open Access Journals (Sweden)

    Bronius VEKTARIS

    2013-09-01

    Full Text Available Dry building mixes, stored in the air, absorb water vapor and CO2 gas and ageing because properties of binding materials, mostly Portland cement, deteriorate after its prehydration and carbonation. In this paper the ageing singularities of dry cement mixes for finishing purposes and additives for retarding this process has been determinated. Ordinary and quickly hardening Portland cements absorb H2O and CO2 more than white cement – about 70 % – 75 % and 30 % – 38 % per month of innitial mass, respectively. White cement is more resistant to prehydration and carbonation, because it contains less C3A, C4AF and alkali, characterized initial activity. Dry mixes with white cement, although slower, but still worse after stored. Influence of routine dry mortar mixes ingredients and additives (methyl cellulose, pigments, sand and lime on prehydration properties of the mixes for finishing purpose is not substantial. Significant positive influence comes from the addition of fatty acid salts (zinc stearate or sodium oleate. The dry cement mixes for finishing purpose has been recomended to hydrophobisate with one of these additives, adding about 1 % by weight of cement during preducing mixes. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5243

  1. Ageing of Dry Cement Mixes for Finishing Purposes

    Directory of Open Access Journals (Sweden)

    Bronius VEKTARIS

    2013-09-01

    Full Text Available Dry building mixes, stored in the air, absorb water vapor and CO2 gas and ageing because properties of binding materials, mostly Portland cement, deteriorate after its prehydration and carbonation. In this paper the ageing singularities of dry cement mixes for finishing purposes and additives for retarding this process has been determinated. Ordinary and quickly hardening Portland cements absorb H2O and CO2 more than white cement – about 70 % – 75 % and 30 % – 38 % per month of innitial mass, respectively. White cement is more resistant to prehydration and carbonation, because it contains less C3A, C4AF and alkali, characterized initial activity. Dry mixes with white cement, although slower, but still worse after stored. Influence of routine dry mortar mixes ingredients and additives (methyl cellulose, pigments, sand and lime on prehydration properties of the mixes for finishing purpose is not substantial. Significant positive influence comes from the addition of fatty acid salts (zinc stearate or sodium oleate. The dry cement mixes for finishing purpose has been recomended to hydrophobisate with one of these additives, adding about 1 % by weight of cement during preducing mixes. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5243

  2. Mixed language programming

    International Nuclear Information System (INIS)

    Burow, Burkhard D.

    1996-01-01

    Computing in the next millennium will be using software from this millennium. Programming languages evolve and new ones continue to be created. The use of legacy code demonstrates why some present and future applications may span programming languages. Even a completely new application may mix programming languages, if it allows its components to be more conveniently expressed. Given the need, mixed language programming should be easy and robust. By resolving a variety of difficulties, the well established cfortran.h package provides, the desired convenient interface across the C and Fortran programming languages, as demonstrated using CERN's Book. (author)

  3. Turbulence and Interfacial Mixing

    Energy Technology Data Exchange (ETDEWEB)

    Glimm, James; Li, Xiaolin

    2005-03-15

    The authors study mix from analytical and numerical points of view. These investigations are linked. The analytical studies (in addition to laboratory experiments) provide bench marks for the direct simulation of mix. However, direct simulation is too detailed to be useful and to expensive to be practical. They also consider averaged equations. Here the major issue is the validation of the closure assumptions. They appeal to the direct simulation methods for this step. They have collaborated with several NNSA teams; moreover, Stony Brook alumni (former students, faculty and research collaborators) presently hold staff positions in NNSA laboratories.

  4. Mixed Reality Systems

    Directory of Open Access Journals (Sweden)

    Dieter Müller

    2009-11-01

    Full Text Available Currently one of the most challenging aspects of human computer interaction design is the integration of physical and digital worlds in a single environment. This fusion involves the development of "Mixed Reality Systems”, including various technologies from the domains of augmented and virtual reality. In this paper I will present related concepts and discuss lessons learned from our own research and prototype development. Our recent work involves the use of mixed reality (as opposed to ‘pure’ virtual reality techniques to support seamless collaborative work between remote and hands-on laboratories.

  5. Carbonate aquifers

    Science.gov (United States)

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

    2012-01-01

    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  6. Optimizing the strategic patient mix

    NARCIS (Netherlands)

    Vanberkel, P.T.; Boucherie, Richardus J.; Hans, Elias W.; Hurink, Johann L.

    In this paper we address the decision of choosing a patient mix for a hospital that leads to the most beneficial treatment case mix. We illustrate how capacity, case mix and patient mix decisions are interrelated and how understanding this complex relationship is crucial for achieving the maximum

  7. In situ enhanced soil mixing. Innovative technology summary report

    International Nuclear Information System (INIS)

    1996-02-01

    In Situ Enhanced Soil Mixing (ISESM) is a treatment technology that has been demonstrated and deployed to remediate soils contaminated with volatile organic compounds (VOCs). The technology has been developed by industry and has been demonstrated with the assistance of the U.S. Department of Energy's Office of Science and Technology and the Office of Environmental Restoration. The technology is particularly suited to shallow applications, above the water table, but can be used at greater depths. ISESM technologies demonstrated for this project include: (1) Soil mixing with vapor extraction combined with ambient air injection. [Contaminated soil is mixed with ambient air to vaporize volatile organic compounds (VOCs). The mixing auger is moved up and down to assist in removal of contaminated vapors. The vapors are collected in a shroud covering the treatment area and run through a treatment unit containing a carbon filter or a catalytic oxidation unit with a wet scrubber system and a high efficiency particulate air (HEPA) filter.] (2) soil mixing with vapor extraction combined with hot air injection [This process is the same as the ambient air injection except that hot air or steam is injected.] (3) soil mixing with hydrogen peroxide injection [Contaminated soil is mixed with ambient air that contains a mist of diluted hydrogen peroxide (H 2 O 2 ) solution. The H 2 O 2 solution chemically oxidizes the VOCs to carbon dioxide (CO 2 ) and water.] (4) soil mixing with grout injection for solidification/stabilization [Contaminated soil is mixed as a cement grout is injected under pressure to solidify and immobilize the contaminated soil in a concrete-like form.] The soils are mixed with a single-blade auger or with a combination of augers ranging in diameter from 3 to 12 feet

  8. Measurement of carbon activity of sodium using nickel tabs and the Harwell Carbon Meter - Preliminary experience

    International Nuclear Information System (INIS)

    Blundell, A.; Thorley, A.W.

    1980-01-01

    Carbon can have an important effect on the mechanical properties of certain constructional materials likely to be used in the LMFBRs. Transfer of carbon will occur between the metal and the sodium at any particular location to bring the chemical potential of carbon in both components to the sam: value. Thus, in a mixed system containing austenitic stainless steel and unstabilized ferritic steel, carbon could be transferred by the sodium from the high carbon activity ferritic to the lower activity austenitic steel. Loss of carbon from the unstabilized ferritic steel leads to a weaker, more ductile material, while carburization of the stainless steel could lead to its embrittlement. Similarly carbon entering the coolant in the form of oil from leaking mechanical pumps could have similar effects on the mechanical property of stainless steels. In the light of these possibilities it is essential to measure the carbon activity of the sodium so that its effect on materials properties can be predicted

  9. Measurement of carbon activity of sodium using nickel tabs and the Harwell Carbon Meter - Preliminary experience

    Energy Technology Data Exchange (ETDEWEB)

    Blundell, A; Thorley, A W [UKAEA, Risley, Warrington, Cheshire (United Kingdom)

    1980-05-01

    Carbon can have an important effect on the mechanical properties of certain constructional materials likely to be used in the LMFBRs. Transfer of carbon will occur between the metal and the sodium at any particular location to bring the chemical potential of carbon in both components to the sam: value. Thus, in a mixed system containing austenitic stainless steel and unstabilized ferritic steel, carbon could be transferred by the sodium from the high carbon activity ferritic to the lower activity austenitic steel. Loss of carbon from the unstabilized ferritic steel leads to a weaker, more ductile material, while carburization of the stainless steel could lead to its embrittlement. Similarly carbon entering the coolant in the form of oil from leaking mechanical pumps could have similar effects on the mechanical property of stainless steels. In the light of these possibilities it is essential to measure the carbon activity of the sodium so that its effect on materials properties can be predicted.

  10. Molten salt destruction process for mixed wastes

    International Nuclear Information System (INIS)

    Upadhye, R.S.; Wilder, J.G.; Karlsen, C.E.

    1993-04-01

    We are developing an advanced two-stage process for the treatment of mixed wastes, which contain both hazardous and radioactive components. The wastes, together with an oxidant gas, such as air, are injected into a bed of molten salt comprising a mixture of sodium-, potassium-, and lithium-carbonates, with a melting point of about 580 degree C. The organic constituents of the mixed waste are destroyed through the combined effect of pyrolysis and oxidation. Heteroatoms. such as chlorine, in the mixed waste form stable salts, such as sodium chloride, and are retained in the melt. The radioactive actinides in the mixed waste are also retained in the melt because of the combined action of wetting and partial dissolution. The original process, consists of a one-stage unit, operated at 900--1000 degree C. The advanced two-stage process has two stages, one for pyrolysis and one for oxidation. The pyrolysis stage is designed to operate at 700 degree C. The oxidation stage can be operated at a higher temperature, if necessary

  11. Sylgard® Mixing Study

    Energy Technology Data Exchange (ETDEWEB)

    Bello, Mollie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Welch, Cynthia F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Goodwin, Lynne Alese [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Keller, Jennie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-08-22

    Sylgard® 184 and Sylgard® 186 silicone elastomers form Dow Corning® are used as potting agents across the Nuclear Weapons Complex. A standardized mixing procedure is required for filled versions of these products. The present study is a follow-up to a mixing study performed by MST-7 which established the best mixing procedure to use when adding filler to either 184 or 186 base resins. The most effective and consistent method of mixing resin and curing agent for three modified silicone elastomer recipes is outlined in this report. For each recipe, sample size, mixing type, and mixing time was varied over 10 separate runs. The results show that the THINKY™ Mixer gives reliable mixing over varying batch sizes and mixing times. Hand Mixing can give improved mixing, as indicated by reduced initial viscosity; however, this method is not consistent.

  12. Glueball-meson mixing

    Energy Technology Data Exchange (ETDEWEB)

    Vento, Vicente [Consejo Superior de Investigaciones Cientificas, Departamento de Fisica Teorica y Instituto de Fisica Corpuscular, Universidad de Valencia, Burjassot (Spain)

    2016-01-15

    Calculations in unquenched QCD for the scalar glueball spectrum have confirmed previous results of Gluodynamics finding a glueball at ∝1750 MeV. I analyze the implications of this discovery from the point of view of glueball-meson mixing in light of the experimental scalar spectrum. (orig.)

  13. Mixed-Initiative Clustering

    Science.gov (United States)

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  14. Mixing Over Rough Topography

    Science.gov (United States)

    2017-10-25

    www.apl.washington.edu/ people /profile.php?last_name=Gregg&first_name=Mike LONG-TERM GOALS To understand quantify diapycnal mixing in the ocean...ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) Office of Naval Research ONR 875 North Randolph Street Arlington, VA 22203-1995 11

  15. Mixed Lubricated Line Contacts

    NARCIS (Netherlands)

    Faraon, I.C.

    2005-01-01

    The present work deals with friction in mixed lubricated line contacts. Components in systems are becoming smaller and due to, for instance power transmitted, partial contact may occur. In industrial applications, friction between the moving contacting surfaces cannot be avoided, therefore it is

  16. Against Mixed Epistemology

    Directory of Open Access Journals (Sweden)

    Joe Milburn

    2015-05-01

    Full Text Available http://dx.doi.org/10.5007/1808-1711.2015v19n2p183 We can call any reductive account of knowledge that appeals to both safety and ability conditions a mixed account of knowledge. Examples of mixed accounts of knowledge include Pritchard’s (2012 Anti-Luck Virtue Epistemology, Kelp’s (2013 Safe-Apt account of knowledge, and Turri’s (2011 Ample belief account of knowledge. Mixed accounts of knowledge are motivated by well-known counterexamples to pure safety and pure ability accounts of knowledge. It is thought that by combining both safety and ability conditions we can give an extensionally adequate reductive account of knowledge. In this paper I argue that the putative counterexamples to pure safety and pure ability accounts of knowledge fail to motivate mixed accounts of knowledge. In particular, I argue that if the putative counterexamples are problematic for safety accounts they are problematic for ability accounts and vice-versa. The reason for this, I argue, is that the safety condition and ability condition should be understood as alternative expressions of the same intuition — that knowledge must come from a reliable source.

  17. Gas adsorption and gas mixture separations using mixed-ligand MOF material

    Science.gov (United States)

    Hupp, Joseph T [Northfield, IL; Mulfort, Karen L [Chicago, IL; Snurr, Randall Q [Evanston, IL; Bae, Youn-Sang [Evanston, IL

    2011-01-04

    A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.

  18. Linear C32H66 hydrocarbon in the mixed state with C10H22 ...

    Indian Academy of Sciences (India)

    Unknown

    S R Research Laboratory for Studies in Crystallization Phenomena, 10-1-96, ... mixed state with certain shorter chain length homologues (SMOLLENCs), estimated ... Methods. Five hydrocarbons of even carbon numbers, C10, C12, C14, C16 ...

  19. Effects of mixed substrates on growth and vitamin production by ...

    African Journals Online (AJOL)

    The effects of mixed carbon sources on growth and production of vitamins E and A by Euglena gracilis cells were investigated in batch culture. The cells were grown mixotrophically in glucose (G), ethanol (E) and a mixture of glucose and ethanol (EG). Cell growth was measured by counting the cell number with microscope, ...

  20. Substrate inhibition kinetics of phenol degradation by binary mixed ...

    African Journals Online (AJOL)

    Steady states of a continuous culture with an inhibitory substrate were used to estimate kinetic parameters under substrate limitation (chemo stat operation). Mixed cultures of an indigenous Pseudomonas fluorescence and Pseudomonas aeruginosa were grown in continuous culture on phenol as the sole source of carbon ...

  1. Estimating foliar biochemistry from hyperspectral data in mixed forest canopy

    DEFF Research Database (Denmark)

    Huber Gharib, Silvia; Kneubühler, Mathias; Psomas, Achilleas

    2008-01-01

    data to estimate the foliar concentration of nitrogen, carbon and water in three mixed forest canopies in Switzerland. With multiple linear regression models, continuum-removed and normalized HyMap spectra were related to foliar biochemistry on an individual tree level. The six spectral wavebands used...

  2. Materials dependence of mixed gas plasticization behavior in asymmetric membranes

    NARCIS (Netherlands)

    Visser, Tymen; Masetto, N.; Wessling, Matthias

    2007-01-01

    The mass transport of asymmetric membranes for the separation of carbon dioxide/methane mixtures is determined by competitive sorption and plasticization. With increasing feed pressure in mixed gas experiments, the selectivity decreases due to both effects. Distinction whether one or the other

  3. Energetics of binary mixed culture of Pseudomonas aeruginosa and ...

    African Journals Online (AJOL)

    Bioenergetic analysis of the growth of the binary mixed culture (Pseudomonas aeruginosa and Pseudomonas fluorescence) on phenol chemostat culture was carried out. The data were checked for consistency using carbon and available electron balances. When more than the minimum number of variables are measured, ...

  4. Improvement of acid protease production by a mixed culture of ...

    African Journals Online (AJOL)

    The synthesis of acid protease by Aspergillus oryzae AS3042 was enhanced significantly with the mixed culture of Aspergillus niger SL-09 using solid-state fermentation technique. The influence of carbon sources, nitrogen sources and the addition of phytic acid on acid protease production were investigated. The enzyme ...

  5. Metabolic modeling of mixed substrate uptake for polyhydroxyalkanoate (PHA) production

    NARCIS (Netherlands)

    Jiang, Y.; Hebly, M.; Kleerebezem, R.; Muyzer, G.; van Loosdrecht, M.C.M.

    2011-01-01

    Polyhydroxyalkanoate (PHA) production by mixed microbial communities can be established in a two-stage process, consisting of a microbial enrichment step and a PHA accumulation step. In this study, a mathematical model was constructed for evaluating the influence of the carbon substrate composition

  6. [Organic carbon and carbon mineralization characteristics in nature forestry soil].

    Science.gov (United States)

    Yang, Tian; Dai, Wei; An, Xiao-Juan; Pang, Huan; Zou, Jian-Mei; Zhang, Rui

    2014-03-01

    Through field investigation and indoor analysis, the organic carbon content and organic carbon mineralization characteristics of six kinds of natural forest soil were studied, including the pine forests, evergreen broad-leaved forest, deciduous broad-leaved forest, mixed needle leaf and Korean pine and Chinese pine forest. The results showed that the organic carbon content in the forest soil showed trends of gradual decrease with the increase of soil depth; Double exponential equation fitted well with the organic carbon mineralization process in natural forest soil, accurately reflecting the mineralization reaction characteristics of the natural forest soil. Natural forest soil in each layer had the same mineralization reaction trend, but different intensity. Among them, the reaction intensity in the 0-10 cm soil of the Korean pine forest was the highest, and the intensities of mineralization reaction in its lower layers were also significantly higher than those in the same layers of other natural forest soil; comparison of soil mineralization characteristics of the deciduous broad-leaved forest and coniferous and broad-leaved mixed forest found that the differences of litter species had a relatively strong impact on the active organic carbon content in soil, leading to different characteristics of mineralization reaction.

  7. Metal-doped single-walled carbon nanotubes and production thereof

    Science.gov (United States)

    Dillon, Anne C.; Heben, Michael J.; Gennett, Thomas; Parilla, Philip A.

    2007-01-09

    Metal-doped single-walled carbon nanotubes and production thereof. The metal-doped single-walled carbon nanotubes may be produced according to one embodiment of the invention by combining single-walled carbon nanotube precursor material and metal in a solution, and mixing the solution to incorporate at least a portion of the metal with the single-walled carbon nanotube precursor material. Other embodiments may comprise sputter deposition, evaporation, and other mixing techniques.

  8. Carbon-On-Carbon Manufacturing

    Science.gov (United States)

    Mungas, Gregory S. (Inventor); Buchanan, Larry (Inventor); Banzon, Jr., Jose T. (Inventor)

    2017-01-01

    The presently disclosed technology relates to carbon-on-carbon (C/C) manufacturing techniques and the resulting C/C products. One aspect of the manufacturing techniques disclosed herein utilizes two distinct curing operations that occur at different times and/or using different temperatures. The resulting C/C products are substantially non-porous, even though the curing operation(s) substantially gasify a liquid carbon-entrained filler material that saturates a carbon fabric that makes up the C/C products.

  9. Increased topsoil carbon stock across China's forests.

    Science.gov (United States)

    Yang, Yuanhe; Li, Pin; Ding, Jinzhi; Zhao, Xia; Ma, Wenhong; Ji, Chengjun; Fang, Jingyun

    2014-08-01

    Biomass carbon accumulation in forest ecosystems is a widespread phenomenon at both regional and global scales. However, as coupled carbon-climate models predicted, a positive feedback could be triggered if accelerated soil carbon decomposition offsets enhanced vegetation growth under a warming climate. It is thus crucial to reveal whether and how soil carbon stock in forest ecosystems has changed over recent decades. However, large-scale changes in soil carbon stock across forest ecosystems have not yet been carefully examined at both regional and global scales, which have been widely perceived as a big bottleneck in untangling carbon-climate feedback. Using newly developed database and sophisticated data mining approach, here we evaluated temporal changes in topsoil carbon stock across major forest ecosystem in China and analysed potential drivers in soil carbon dynamics over broad geographical scale. Our results indicated that topsoil carbon stock increased significantly within all of five major forest types during the period of 1980s-2000s, with an overall rate of 20.0 g C m(-2) yr(-1) (95% confidence interval, 14.1-25.5). The magnitude of soil carbon accumulation across coniferous forests and coniferous/broadleaved mixed forests exhibited meaningful increases with both mean annual temperature and precipitation. Moreover, soil carbon dynamics across these forest ecosystems were positively associated with clay content, with a larger amount of SOC accumulation occurring in fine-textured soils. In contrast, changes in soil carbon stock across broadleaved forests were insensitive to either climatic or edaphic variables. Overall, these results suggest that soil carbon accumulation does not counteract vegetation carbon sequestration across China's forest ecosystems. The combination of soil carbon accumulation and vegetation carbon sequestration triggers a negative feedback to climate warming, rather than a positive feedback predicted by coupled carbon-climate models

  10. Porous carbons

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. Carbon in dense as well as porous solid form is used in a variety of applications. Activated porous carbons are made through pyrolysis and activation of carbonaceous natural as well as synthetic precursors. Pyrolysed woods replicate the structure of original wood but as such possess very low surface areas and ...

  11. Carbon photonics

    Energy Technology Data Exchange (ETDEWEB)

    Konov, V I [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-11-30

    The properties of new carbon materials (single-crystal and polycrystalline CVD diamond films and wafers, single-wall carbon nanotubes and graphene) and the prospects of their use as optical elements and devices are discussed. (optical elements of laser devices)

  12. Carbon payments and low-cost conservation.

    Science.gov (United States)

    Crossman, Neville D; Bryan, Brett A; Summers, David M

    2011-08-01

    A price on carbon is expected to generate demand for carbon offset schemes. This demand could drive investment in tree-based monocultures that provide higher carbon yields than diverse plantings of native tree and shrub species, which sequester less carbon but provide greater variation in vegetation structure and composition. Economic instruments such as species conservation banking, the creation and trading of credits that represent biological-diversity values on private land, could close the financial gap between monocultures and more diverse plantings by providing payments to individuals who plant diverse species in locations that contribute to conservation and restoration goals. We studied a highly modified agricultural system in southern Australia that is typical of many temperate agriculture zones globally (i.e., has a high proportion of endangered species, high levels of habitat fragmentation, and presence of non-native species). We quantified the economic returns from agriculture and from carbon plantings (monoculture and mixed tree and shrubs) under six carbon-price scenarios. We also identified high-priority locations for restoration of cleared landscapes with mixed tree and shrub carbon plantings. Depending on the price of carbon, direct annual payments to landowners of AU$7/ha/year to $125/ha/year (US$6-120/ha/year) may be sufficient to augment economic returns from a carbon market and encourage tree plantings that contribute more to the restoration of natural systems and endangered species habitats than monocultures. Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market. Overall, however, less carbon is sequestered by mixed native tree and shrub plantings. © 2011 Society for Conservation Biology.

  13. Ocean uptake of carbon dioxide

    International Nuclear Information System (INIS)

    Peng, Tsung-Hung; Takahashi, Taro

    1993-01-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0 2 include carbon chemistry, distribution of alkalinity, pCO 2 and total concentration of dissolved C0 2 , sea-air pCO 2 difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0 2 uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0 2 from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0 2 fertilization is a potential candidate for such missing carbon sinks

  14. Unitarity constraints on trimaximal mixing

    International Nuclear Information System (INIS)

    Kumar, Sanjeev

    2010-01-01

    When the neutrino mass eigenstate ν 2 is trimaximally mixed, the mixing matrix is called trimaximal. The middle column of the trimaximal mixing matrix is identical to tribimaximal mixing and the other two columns are subject to unitarity constraints. This corresponds to a mixing matrix with four independent parameters in the most general case. Apart from the two Majorana phases, the mixing matrix has only one free parameter in the CP conserving limit. Trimaximality results in interesting interplay between mixing angles and CP violation. A notion of maximal CP violation naturally emerges here: CP violation is maximal for maximal 2-3 mixing. Similarly, there is a natural constraint on the deviation from maximal 2-3 mixing which takes its maximal value in the CP conserving limit.

  15. Renormalization of fermion mixing

    International Nuclear Information System (INIS)

    Schiopu, R.

    2007-01-01

    Precision measurements of phenomena related to fermion mixing require the inclusion of higher order corrections in the calculation of corresponding theoretical predictions. For this, a complete renormalization scheme for models that allow for fermion mixing is highly required. The correct treatment of unstable particles makes this task difficult and yet, no satisfactory and general solution can be found in the literature. In the present work, we study the renormalization of the fermion Lagrange density with Dirac and Majorana particles in models that involve mixing. The first part of the thesis provides a general renormalization prescription for the Lagrangian, while the second one is an application to specific models. In a general framework, using the on-shell renormalization scheme, we identify the physical mass and the decay width of a fermion from its full propagator. The so-called wave function renormalization constants are determined such that the subtracted propagator is diagonal on-shell. As a consequence of absorptive parts in the self-energy, the constants that are supposed to renormalize the incoming fermion and the outgoing antifermion are different from the ones that should renormalize the outgoing fermion and the incoming antifermion and not related by hermiticity, as desired. Instead of defining field renormalization constants identical to the wave function renormalization ones, we differentiate the two by a set of finite constants. Using the additional freedom offered by this finite difference, we investigate the possibility of defining field renormalization constants related by hermiticity. We show that for Dirac fermions, unless the model has very special features, the hermiticity condition leads to ill-defined matrix elements due to self-energy corrections of external legs. In the case of Majorana fermions, the constraints for the model are less restrictive. Here one might have a better chance to define field renormalization constants related by

  16. Renormalization of fermion mixing

    Energy Technology Data Exchange (ETDEWEB)

    Schiopu, R.

    2007-05-11

    Precision measurements of phenomena related to fermion mixing require the inclusion of higher order corrections in the calculation of corresponding theoretical predictions. For this, a complete renormalization scheme for models that allow for fermion mixing is highly required. The correct treatment of unstable particles makes this task difficult and yet, no satisfactory and general solution can be found in the literature. In the present work, we study the renormalization of the fermion Lagrange density with Dirac and Majorana particles in models that involve mixing. The first part of the thesis provides a general renormalization prescription for the Lagrangian, while the second one is an application to specific models. In a general framework, using the on-shell renormalization scheme, we identify the physical mass and the decay width of a fermion from its full propagator. The so-called wave function renormalization constants are determined such that the subtracted propagator is diagonal on-shell. As a consequence of absorptive parts in the self-energy, the constants that are supposed to renormalize the incoming fermion and the outgoing antifermion are different from the ones that should renormalize the outgoing fermion and the incoming antifermion and not related by hermiticity, as desired. Instead of defining field renormalization constants identical to the wave function renormalization ones, we differentiate the two by a set of finite constants. Using the additional freedom offered by this finite difference, we investigate the possibility of defining field renormalization constants related by hermiticity. We show that for Dirac fermions, unless the model has very special features, the hermiticity condition leads to ill-defined matrix elements due to self-energy corrections of external legs. In the case of Majorana fermions, the constraints for the model are less restrictive. Here one might have a better chance to define field renormalization constants related by

  17. Experiments in mixed reality

    Science.gov (United States)

    Krum, David M.; Sadek, Ramy; Kohli, Luv; Olson, Logan; Bolas, Mark

    2010-01-01

    As part of the Institute for Creative Technologies and the School of Cinematic Arts at the University of Southern California, the Mixed Reality lab develops technologies and techniques for presenting realistic immersive training experiences. Such experiences typically place users within a complex ecology of social actors, physical objects, and collections of intents, motivations, relationships, and other psychological constructs. Currently, it remains infeasible to completely synthesize the interactivity and sensory signatures of such ecologies. For this reason, the lab advocates mixed reality methods for training and conducts experiments exploring such methods. Currently, the lab focuses on understanding and exploiting the elasticity of human perception with respect to representational differences between real and virtual environments. This paper presents an overview of three projects: techniques for redirected walking, displays for the representation of virtual humans, and audio processing to increase stress.

  18. Marketing-Mix

    OpenAIRE

    Huppertz, Matthias; Schneider, Andreas Dirk

    2006-01-01

    Der Marketing-Mix mit seinen 4Ps zur operativen Marketingplanung ist innerhalb des Marketing-Managements die nächste Stufe nach der Marktanalyse in dem die strategische Marketingplanung erarbeitet wurde. Die strategische Marketingplanung befasst sich mit der Analyse des Zielmarktes und der grundsätzlichen Zielrichtung des Unternehmens. Auf Basis der gewonnenen Erkenntnisse wird in der Phase der operativen Marketingplanung versucht, die Unternehmensaktivitäten am Zielmarkt des Unternehmens aus...

  19. Stability of mixing layers

    Science.gov (United States)

    Tam, Christopher; Krothapalli, A

    1993-01-01

    The research program for the first year of this project (see the original research proposal) consists of developing an explicit marching scheme for solving the parabolized stability equations (PSE). Performing mathematical analysis of the computational algorithm including numerical stability analysis and the determination of the proper boundary conditions needed at the boundary of the computation domain are implicit in the task. Before one can solve the parabolized stability equations for high-speed mixing layers, the mean flow must first be found. In the past, instability analysis of high-speed mixing layer has mostly been performed on mean flow profiles calculated by the boundary layer equations. In carrying out this project, it is believed that the boundary layer equations might not give an accurate enough nonparallel, nonlinear mean flow needed for parabolized stability analysis. A more accurate mean flow can, however, be found by solving the parabolized Navier-Stokes equations. The advantage of the parabolized Navier-Stokes equations is that its accuracy is consistent with the PSE method. Furthermore, the method of solution is similar. Hence, the major part of the effort of the work of this year has been devoted to the development of an explicit numerical marching scheme for the solution of the Parabolized Navier-Stokes equation as applied to the high-seed mixing layer problem.

  20. MARKETING MIX IN SPORT

    Directory of Open Access Journals (Sweden)

    Srećko Novaković

    2011-03-01

    Full Text Available Marketing mix'' along the term of life cycle has robbed the trademark for the conception of marketing and the market direction of company, corporations and institutions. Essence marketing-mixa is in the simultaneous determining of the target market group of consumer (the buyer or stays the public and specially prepared and the coordinated impact of elements mixa, and this is the product, price, distributions and graduation ceremonies. Given that is mix combinations of verified variables, companies he use in order to would achieve are wished the scope sales on the target market. In the wider context significant influence of environment on the chosen structure marketing-mixa have not only technological, economic and competitive services already and socially-owned, legislative, legal and political services. From those reasons chant the marketing -mixa occasionally replaces expression are coordinated term acts on the market. Elements marketing-mix-and at sport marketings same are as well as at marketings every other activity. They contain the sportively product and the service, appreciate the sport product and services, distribution of sport product and services and the promotion of sport product and services.

  1. Mixing of solids

    CERN Document Server

    Weinekötter, Ralf

    2000-01-01

    This book is a welcome edition to the Particle Technology Series, formerly Powder Technology Series. It is the second book in the series which describes powder mixing and we make no excuses for that. The topic of powder mixing is fundamental to powder technology and is one which always aroses interest. That will not change. As powder products become more complex they will pose new mixing problems. The solutions lie in the intelligent use of equipment, an understanding of powder properties and a good knowledge of basic statistics. The authors of this book have presented those three ingredients with great clarity. The book is based on long experience and deep thought, I have enjoyed reading it and am pleased to recommend it. Delft University of Technology, NL-Delft, July 1999 Brian Scarlett, Series Editor IX VII Foreword to the English Edition In response to many enquiries from industrial organisations and institutes involved with the technology of processing bulk materials, we are pleased to present the Englis...

  2. Mixing, entropy and competition

    International Nuclear Information System (INIS)

    Klimenko, A Y

    2012-01-01

    Non-traditional thermodynamics, applied to random behaviour associated with turbulence, mixing and competition, is reviewed and analysed. Competitive mixing represents a general framework for the study of generic properties of competitive systems and can be used to model a wide class of non-equilibrium phenomena ranging from turbulent premixed flames and invasion waves to complex competitive systems. We demonstrate consistency of the general principles of competition with thermodynamic description, review and analyse the related entropy concepts and introduce the corresponding competitive H-theorem. A competitive system can be characterized by a thermodynamic quantity—competitive potential—which determines the likely direction of evolution of the system. Contested resources tend to move between systems from lower to higher values of the competitive potential. There is, however, an important difference between conventional thermodynamics and competitive thermodynamics. While conventional thermodynamics is constrained by its zeroth law and is fundamentally transitive, the transitivity of competitive thermodynamics depends on the transitivity of the competition rules. Intransitivities are common in the real world and are responsible for complex behaviour in competitive systems. This work follows ideas and methods that have originated from the analysis of turbulent combustion, but reviews a much broader scope of issues linked to mixing and competition, including thermodynamic characterization of complex competitive systems with self-organization. The approach presented here is interdisciplinary and is addressed to the general educated readers, whereas the mathematical details can be found in the appendices. (comment)

  3. Company Marketing Mix

    OpenAIRE

    Vyroubalová, Klára

    2015-01-01

    Tématem této bakalářské práce je ,,Marketingový mix společnosti SKITECH, s. r. o.“ Práce se zabývá vypracováním marketingového mixu a navrţením lyţařských produktů skiareálu. Předpokladem pro vytvoření marketingového mixu je provedení SWOT analýzy a analýzy konkurence. Na základě těchto výsledků budou stanoveny vize a cíle skiareálu a návrhy jednotlivých produktů. V závěrečné části je aplikován marketingový mix na konkrétní produkt. This thesis deals with the marketing mix of the SKITECH c...

  4. Stable carbon, nitrogen and sulfur isotopes in non-carbonate fractions of cold-seep carbonates

    Science.gov (United States)

    Feng, Dong; Peng, Yongbo; Peckmann, Jörn; Roberts, Harry; Chen, Duofu

    2017-04-01

    Sulfate-driven anaerobic oxidation of methane (AOM) supports chemosynthesis-based communities and limits the release of methane from marine sediments. This process promotes the formation of carbonates close to the seafloor along continental margins. The geochemical characteristics of the carbonate minerals of these rocks are increasingly understood, questions remain about the geochemical characteristics of the non-carbonate fractions. Here, we report stable carbon, nitrogen and sulfur isotope patterns in non-carbonate fractions of seep carbonates. The authigenic carbonates were collected from three modern seep provinces (Black Sea, Gulf of Mexico, and South China Sea) and three ancient seep deposits (Marmorito, northern Italy, Miocene; SR4 deposit of the Lincoln Creek Formation and Whiskey Creek, western Washington, USA, Eocene to Oligocene). The δ13C values of non-carbonate fractions range from ˜-25‰ to -80‰ VPDB. These values indicate that fossil methane mixed with varying amounts of pelagic organic matter is the dominant source of carbon in these fractions. The relatively small offset between the δ34S signatures of the non-carbonate fractions and the respective sulfide minerals suggests that locally produced hydrogen sulfide is the main source of sulfur in seep environments. The δ15N values of the non-carbonate fractions are generally lower than the corresponding values of deep-sea sediments, suggesting that organic nitrogen is mostly of a local origin. This study reveals the potential of using δ13C, δ15N, δ34S values to discern seep and non-seep deposits. In cases where δ13Ccarbonate values are only moderately low due to mixing processes and lipid biomarkers have been erased in the course of burial, it is difficult to trace back AOM owing to the lack of other records. This problem is even more pronounced when authigenic carbonate is not available in ancient seep environments. Acknowledgments: The authors thank BOEM and NOAA for their years' support

  5. Carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The document identifies the main sources of carbon monoxide (CO) in the general outdoor atmosphere, describes methods of measuring and monitoring its concentration levels in the United Kingdom, and discusses the effects of carbon monoxide on human health. Following its review, the Panel has put forward a recommendation for an air quality standard for carbon monoxide in the United Kingdom of 10 ppm, measured as a running 8-hour average. The document includes tables and graphs of emissions of CO, in total and by emission source, and on the increase in blood levels of carboxyhaemoglobin with continuing exposure to CO. 11 refs., 4 figs., 4 tabs.

  6. The Value of Mixed Methods Research: A Mixed Methods Study

    Science.gov (United States)

    McKim, Courtney A.

    2017-01-01

    The purpose of this explanatory mixed methods study was to examine the perceived value of mixed methods research for graduate students. The quantitative phase was an experiment examining the effect of a passage's methodology on students' perceived value. Results indicated students scored the mixed methods passage as more valuable than those who…

  7. Carbon-14 as an hydrology tool

    International Nuclear Information System (INIS)

    Garcia y G, E.; Albarran B, R.

    1977-01-01

    Carbon-14 and tritium results from the action of cosmic radiation and of nuclear tests also. In general carbon-14 resulting from nuclear arms tests is of no interest from the hydrological point-of view, as tritium is a more efficient marker of juvenile waters through having a much shorter disintegration period. Radioactive carbon oxidizes and forms carbon dioxide which mixes with atmospheric carbon dioxide and enters the global carbon cycle. Use of carbon-14 in the dating of subterranean waters is based on the fact that the carbon dioxide found in the soil zone is of biologic origin arising from the respiration and decomposition of plant roots. Therefore it contains carbon-14 taken from the atmosphere by the plants. This carbon dioxide of biogenic origin is dissolved in infiltrating water and is borne along towards the water bearing strata. Its carbon-14 content decrease through radioactive loss and the fractional remainder of the original contents indicates the time which has passed since it left the supply zone in the soil, that is, the time passed since it filtrated the water. (author)

  8. Cornell Mixing Zone Expert System

    Science.gov (United States)

    This page provides an overview Cornell Mixing Zone Expert System water quality modeling and decision support system designed for environmental impact assessment of mixing zones resulting from wastewater discharge from point sources

  9. Warm mix asphalt : final report.

    Science.gov (United States)

    2014-11-01

    The performance of pavements constructed using warm mix asphalt (WMA) technology were : compared to the performance of conventional hot mix asphalt (HMA) pavements placed on the : same project. Measurements of friction resistance, rutting/wear, ride ...

  10. Calcium Carbonate

    Science.gov (United States)

    ... Calcium is needed by the body for healthy bones, muscles, nervous system, and heart. Calcium carbonate also ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

  11. Lagrangian Studies of Lateral Mixing

    Science.gov (United States)

    2017-09-19

    Final Technical 3. DATES COVERED (From - To) 01/01/2009 – 12/31/2015 4. TITLE AND SUBTITLE Lagrangian Studies of Lateral Mixing 5a. CONTRACT NUMBER...public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Lateral Mixing Experiment (LATMIX) focused on mixing and...anomalies. LATMIX2 targeted the wintertime Gulf Stream, where deep mixed layers, strong lateral density gradients (Gulf Stream north wall) and the

  12. The resilience of paradigm mixes

    DEFF Research Database (Denmark)

    Daugbjerg, Carsten; Farsund, Arild Aurvåg; Langhelle, Oluf

    2017-01-01

    This paper argues that a policy regime based on a paradigm mix may be resilient when challenged by changing power balances and new agendas. Controversies between the actors can be contained within the paradigm mix as it enables them to legitimize different ideational positions. Rather than engaging...... context changed. The paradigm mix proved sufficiently flexible to accommodate food security concerns and at the same time continue to take steps toward further liberalization. Indeed, the main players have not challenged the paradigm mix....

  13. The Effect of Rubber Mixing Process on The Curing Characteristics of Natural Rubber

    Directory of Open Access Journals (Sweden)

    Abu Hasan

    2013-04-01

    Full Text Available This research is aimed at studying the relationship between rubber mixing processes and curing characteristics of natural rubber. The curing characteristic analysis was carried out through a natural rubber formula having been masticated and mixed, followed by curing. As many as four mastication methods were finely applied; each respected four sequences of rubber mixing process. In the first method, rubber was masticated for 5 minutes and then rubber chemicals and carbon black N 330 were  simultaneously added. In the second and the third methods, rubber was masticated for 1 minute and then carbon blacks and rubber chemicals were also simultaneously added but using different type of fillers. In the fourth method, rubber was masticated for 3 minutes and then rubber chemicals and carbon black were subsequently added. The additions of rubber chemicals and carbon blacks to the masticated rubber were distinguished by the sequence and time allocated for each mixing process. The carbon blacks were added in two stages by which 10 phr was added first and the remaining 40 phr was added later along with oil. In another method, ratios of the carbon blacks addition (as done in the first  and the second stages were 20:30, 30:20, and 40:10. The examination results showed that rubber mixing process gave an impact on the changes of curing characteristics. They were much affected by the method of carbon black addition. The mixing temperature also had an effect on both curing time and curing rate in which the higher the mixing temperature, the lower the curing time and curing rate. Vulcanization temperature also affected the curing time and curing rate in which the higher the vulcanization temperature, the lower the curing time and the higher the curing rate. Lastly, particle size of carbon black also gave an impact on the curing time and curing rate in which the smaller the particle size, the lower the curing time and the higher the curing rate.

  14. Evaluation of Carbon sequestration in pure and mixed Plantations of ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2Associate Prof., Faculty of Forest Sciences, Sari University of Agricultural Sciences and Natural Resources, ... The deputy of Natural Resources and Watershed Alborz Province, I. R. Iran ... income derived from the timber production and from.

  15. Rubber mixing process and its relationship with bound rubber and crosslink density

    Science.gov (United States)

    Hasan, A.; Rochmadi; Sulistyo, H.; Honggokusumo, S.

    2017-06-01

    This research studied the relationship between bound rubber and crosslink density based on rubber mixing process. Bound rubber was obtained after natural rubber was masticated and mixed with rubber chemicals and filler while crosslink density was collected after rubber compound was vulcanized. Four methods are used and each method refers to four ways of incorporating carbon black during mixing. The first method, after rubber was masticated for 5 minutes, the addition of rubber chemicals and filler was done simultaneously. Rubber was masticated for 1 minute and continued mixing of rubber chemicals and filler where mixing was different from first method. This was the second method. The third method was the same as the second method but the filler used N 660 while in the second method N 330. The last method is not the same as the first and second, the rubber is only masticated for 3 minutes and then mixed with filler and followed by rubber chemicals sequentially. The results showed that bound rubber and crosslink density were influenced by mixing and mastication process. Bound rubber dropped and crosslink density was relatively stable in the first three mixing methods for increasing carbon black at the beginning of the mixing process. Bound rubber and crosslink density stated opposite results in the fourth mixing method. The higher the bound rubber the lower the crosslink density. Without regard to mixing methods, there is a non-linear relationship between bound rubber formation and crosslink density determination

  16. Mixing properties of quantum systems

    International Nuclear Information System (INIS)

    Narnhofer, H.; Thirring, W.

    1988-01-01

    We generalize the classical notion of topological mixing for automorphisms of C * -algebras in two ways. We show that for Galilean invariant Fermi systems the weaker form of mixing is satisfied. With some additional requirement on the range of the interaction we can also demonstrate the stronger mixing property. (Author)

  17. Infiltrated carbon foam composites

    Science.gov (United States)

    Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

    2012-01-01

    An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

  18. B Lifetimes and Mixing

    International Nuclear Information System (INIS)

    Evans, Harold G.

    2009-01-01

    The Tevatron experiments, CDF and D0, have produced a wealth of new B-physics results since the start of Run II in 2001. We've observed new B-hadrons, seen new effects, and increased many-fold the precision with which we know the properties of b-quark systems. In these proceedings, we will discuss two of the most fruitful areas in the Tevatron B-physics program: lifetimes and mixing. We'll examine the experimental issues driving these analyses, present a summary of the latest results, and discuss prospects for the future.

  19. Transition mixing among baryons

    International Nuclear Information System (INIS)

    Faiman, D.

    1976-01-01

    A degenerate perturbation theory model for mass splitting within the 70,1 - baryon multiplet is proposed. It is found that dominance of the lowest-lying two-body 56x35 intermediate states produces mixing angles in fair approximation to those previously deduced from SU(6)sub(W) analysis of decay data. The prediction of the couplings of all hitherto undetected members of the multiplet and of mass were made. The results call into question the nature of Λ (1405). (author)

  20. Mixed dimers, ch. 7

    International Nuclear Information System (INIS)

    Deursen, A.P.J. van; Reuss, J.

    1976-01-01

    An attempt has been made to detect mixed dimers in nozzle beams of mixtures; NeAr and HeNe dimers were observed with sufficient intensity to determine the total collision cross section. A similar attempt for H 2 Ar was partially hampered by the circumstance that the corresponding HAr + ion must be detected on the wing of the thousand times larger Ar + peak. The search for H 2 He, H 2 Ne and HeAr dimers was not successful, due to masking ion peaks, H 5 + for HHe + , 21 Ne + for H 20 Ne + , and CO 2 + for HeAr + . (Auth.)

  1. Mixed Interaction Spaces

    DEFF Research Database (Denmark)

    Lykke-Olesen, Andreas; Eriksson, E.; Hansen, T.R.

    In this paper, we describe a new interaction technique for mobile devices named Mixed Interaction Space that uses the camera of the mobile device to track the position, size and rotation of a fixed-point. In this demonstration we will present a system that uses a hand-drawn circle, colored object...... or a person’s face as a fixed-point to determine the location of the device. We use these features as a 4 dimensional input vector to a set of different applications....

  2. MixedNotes

    DEFF Research Database (Denmark)

    Jokela, Tero; Lucero, Andrés

    2014-01-01

    Affinity Diagramming is a technique to organize and make sense of qualitative data. It is commonly used in Contextual Design and HCI research. However, preparing notes for and building an Affinity Diagram remains a laborious process, with a wide variety of different approaches and practices....... In this paper, we present MixedNotes, a novel technique to prepare physical paper notes for Affinity Diagramming, and a software tool to support this technique. The technique has been tested with large real-life Affinity Diagrams with overall positive results....

  3. Coloring mixed hypergraphs

    CERN Document Server

    Voloshin, Vitaly I

    2002-01-01

    The theory of graph coloring has existed for more than 150 years. Historically, graph coloring involved finding the minimum number of colors to be assigned to the vertices so that adjacent vertices would have different colors. From this modest beginning, the theory has become central in discrete mathematics with many contemporary generalizations and applications. Generalization of graph coloring-type problems to mixed hypergraphs brings many new dimensions to the theory of colorings. A main feature of this book is that in the case of hypergraphs, there exist problems on both the minimum and th

  4. Gadolinium DTPA-monoamide complexes incorporated into mixed micelles as possible MRI contrast agents

    OpenAIRE

    Parac-Vogt, Tatjana; Kimpe, Kristof; Laurent, Sophie; Pierart, Corinne; Vander Elst, Luce; Muller, Robert N.; Binnemans, Koen

    2004-01-01

    Four monoamide derivatives of Gd-DTPA with alkyl chains consisting of 12, 14, 16, or 18 carbon atoms were synthesized. The gadolinium(III) complexes with chain lengths of 14, 16 or 18 carbon atoms were efficiently incorporated into mixed micelles whereas the complex with a chain length of 12 carbon atoms was not incorporated into a micellar structure. The size distribution of the micelles was measured by photon correlation spectroscopy. The mean sizes of the micelles for all the complexes lay...

  5. System equivalent model mixing

    Science.gov (United States)

    Klaassen, Steven W. B.; van der Seijs, Maarten V.; de Klerk, Dennis

    2018-05-01

    This paper introduces SEMM: a method based on Frequency Based Substructuring (FBS) techniques that enables the construction of hybrid dynamic models. With System Equivalent Model Mixing (SEMM) frequency based models, either of numerical or experimental nature, can be mixed to form a hybrid model. This model follows the dynamic behaviour of a predefined weighted master model. A large variety of applications can be thought of, such as the DoF-space expansion of relatively small experimental models using numerical models, or the blending of different models in the frequency spectrum. SEMM is outlined, both mathematically and conceptually, based on a notation commonly used in FBS. A critical physical interpretation of the theory is provided next, along with a comparison to similar techniques; namely DoF expansion techniques. SEMM's concept is further illustrated by means of a numerical example. It will become apparent that the basic method of SEMM has some shortcomings which warrant a few extensions to the method. One of the main applications is tested in a practical case, performed on a validated benchmark structure; it will emphasize the practicality of the method.

  6. Wave mixing spectroscopy

    International Nuclear Information System (INIS)

    Smith, R.W.

    1980-08-01

    Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr +3 :LaF 3 verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the 3 H 4 , 3 H 6 , and 3 P 0 levels of the praseodymium ions

  7. Mixed RIA standard

    International Nuclear Information System (INIS)

    Talan, P.; Mucha, J.; Krizan, J.

    1986-01-01

    For the radioimmunoassay of digoxin, 3,5,3'-triiodothyronine, 17β-estradiol, progesterone, testosterone and α 1 -fetoprotein a mixed standard was prepared of these substances in a gamma globulin solution at a concentration of 0.8 to 1.4 wt.% in an aqueous buffer at pH within the range of 6 - 9. The standard contains digoxin at a concentration of 10 -4 to 10 nmol/l, 17β-estradiol at 10 -4 to 2 nmol/l, progesteron at 10 -4 to 100 nmol/l, testosterone at 1o -4 to 21 nmol/l, and α 1 -fetoprotein at 10 -4 to 10 nmol/l with at least two of these substances having concentrations higher than 10 -3 nmol/l. Examples are given of the preparation of the mixed standard with different concentrations of the components. The use of the standard has the following advantages: it is labor saving, reduces the risk of failure in the manufacture of RIA kits, eliminates mistakes in the selection of kits for the determination of different substances and allows a more economical use of material. (E.S.)

  8. Isospin mixing in light nuclei

    International Nuclear Information System (INIS)

    Ludwig, E.J.; Clegg, T.B.; Fauber, R.E.; Karwowski, H.J.; Mooney, T.M.; Thompson, W.J.

    1985-01-01

    This program has provided accurate measurements of isospin mixing (ΔT = 1,2) in proton elastic scattering on even-even target nuclei up to A = 40. In order to improve experimental results and to test the hypothesis that isospin mixing is dominated by mixing in the target ground state (as opposed to mixing in the compound system) the authors have undertaken to (1) extend the proton scattering results to additional T = 3/2 states in certain compound systems and (2) examine processes which can proceed by only isotensor mixing (ΔT = 2) in order to isolate the effects of that contribution

  9. Enthalpy generation from mixing in hohlraum-driven targets

    Science.gov (United States)

    Amendt, Peter; Milovich, Jose

    2016-10-01

    The increase in enthalpy from the physical mixing of two initially separated materials is analytically estimated and applied to ICF implosions and gas-filled hohlraums. Pressure and temperature gradients across a classical interface are shown to be the origin of enthalpy generation from mixing. The amount of enthalpy generation is estimated to be on the order of 100 Joules for a 10 micron-scale annular mixing layer between the solid deuterium-tritium fuel and the undoped high-density carbon ablator of a NIF-scale implosion. A potential resonance is found between the mixing layer thickness and gravitational (Cs2/ g) and temperature-gradient scale lengths, leading to elevated enthalpy generation. These results suggest that if mixing occurs in current capsule designs for the National Ignition Facility, the ignition margin may be appreciably eroded by the associated enthalpy of mixing. The degree of enthalpy generation from mixing of high- Z hohlraum wall material and low- Z gas fills is estimated to be on the order of 100 kJ or more for recent NIF-scale hohlraum experiments, which is consistent with the inferred missing energy based on observed delays in capsule implosion times. Work performed under the auspices of Lawrence Livermore National Security, LLC (LLNS) under Contract No. DE-AC52-07NA27344.

  10. Carbon sequestration.

    Science.gov (United States)

    Lal, Rattan

    2008-02-27

    Developing technologies to reduce the rate of increase of atmospheric concentration of carbon dioxide (CO2) from annual emissions of 8.6PgCyr-1 from energy, process industry, land-use conversion and soil cultivation is an important issue of the twenty-first century. Of the three options of reducing the global energy use, developing low or no-carbon fuel and sequestering emissions, this manuscript describes processes for carbon (CO2) sequestration and discusses abiotic and biotic technologies. Carbon sequestration implies transfer of atmospheric CO2 into other long-lived global pools including oceanic, pedologic, biotic and geological strata to reduce the net rate of increase in atmospheric CO2. Engineering techniques of CO2 injection in deep ocean, geological strata, old coal mines and oil wells, and saline aquifers along with mineral carbonation of CO2 constitute abiotic techniques. These techniques have a large potential of thousands of Pg, are expensive, have leakage risks and may be available for routine use by 2025 and beyond. In comparison, biotic techniques are natural and cost-effective processes, have numerous ancillary benefits, are immediately applicable but have finite sink capacity. Biotic and abiotic C sequestration options have specific nitches, are complementary, and have potential to mitigate the climate change risks.

  11. Frontogenesis and turbulent mixing

    Science.gov (United States)

    Zhang, S.; Chen, F.; Shang, Q.

    2017-12-01

    A hydrological investigation was conducted in the shelf of eastern Hainan island during July 2012. With the in-situ measurements from four cross-shelf sections and satellite data, the submesoscale process of the fronts are discussed in this paper, the seasonal variation characteristics of thermal front, the three-dimensional structure, dynamic characteristics of frontal and mixed characteristics in the shelf sea of eastern Hainan island. It's obviously that the thermal front has a seasonal variation: the front is strongest in winter, and decreased gradually in spring and summer. However, it fade and disappear in fall. The core region of the front also changes with the seasons, it moved southward gradually from mainly distributed in the upwelling zone and the front center is not obvious in summer. it is a typical upwelling front in summer, the near shore is compensated with the underlying low-temperature and high-sale water , while the offshore is the high-temperature and low-salinity shelf water. The thermal front distribution is located in the 100m isobaths. The frontal intensity is reduced with increasing depth, and position goes to offshore. Subsurface temperature front is significantly higher in the surface of the sea, which may cause by the heating of nearshore sea surface water and lead to the weakening horizontal temperature gradient. Dynamic characteristics of the front has a great difference in both sides. The O(1) Rossby number is positive on the dense side and negative on the light side. The maximum of along-frontal velocity is 0.45m/s and the stretching is strengthened by strong horizontal shear, also is the potential vorticity, which can trace the cross front Ekman transport. We obtained the vertical velocity with by quasi-geostrophic omega equation and grasped the ageostrophic secondary circulation. The magnitude of frontal vertical velocity is O(10-5) and causes downwelling on the dense side and upwelling on the light side, which constitute the

  12. Distribution of Carbon Dioxide Produced by People in a Room:

    DEFF Research Database (Denmark)

    Naydenov, Kiril Georgiev; Baránková, Petra; Sundell, Jan

    2004-01-01

    Carbon dioxide exhaled by people can be used as a tracer gas for air change measurements in homes. Good mixing of tracer gas with room air is a necessary condition to obtain accurate results. However, the use of fans to ensure mixing is inconvenient. The natural room distribution of metabolic CO2...

  13. Mixed plasma-facing materials research at INEEL

    International Nuclear Information System (INIS)

    Anderl, R.A.; Longhurst, G.R.; Pawelko, R.J.

    2001-01-01

    Mixed-materials research at the Idaho National Engineering and Environmental Laboratory (INEEL) has focused on Be-C and W-C systems. The purpose of this work was to investigate hydrogen isotope retention in these systems. Plasma-mixed material layers using carbon coated Be and W specimens that were heat-treated and tungsten carbide specimens prepared by chemical vapor deposition (CVD) were simulated. Hydrogen isotope retention was investigated by means of thermal desorption spectroscopy (TDS) measurements on deuterium implanted samples

  14. The three pillar strategy for power generation mix - An analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kehlhofer, Rolf; Hatt, Stefan

    2010-09-15

    Low carbon intensity, load following capability and least cost production are the requirements for a successful energy generation mix. This paper presents an analysis of an optimized mix of technologies 'fulfilling the above criteria' based on the energy production portfolio of a number of key countries. The subjects covered include: - comparison of different production technologies (including future costs of emissions) - grid requirements for flexible and dispatchable variable production capabilities - possibilities and limitations of energy production from renewables - why improved overall energy efficiency leads to higher consumption of electricity.

  15. Mixed Partnering and Parenting

    DEFF Research Database (Denmark)

    Singla, Rashmi

    relationship is formed across two socially significant groups: ethnic, religious, region/caste, thus the present study has broad relevance. This proposal delineates the demographic details, intervention process of two ethnically mixed- marriage cases. Cases’ analyses are combined with relevant results from...... an empirical study (Singla, 2015) about intermarried couples to present lessons for counselling and psychotherapy good practices. The couples in the two cases and ten in-depth interviews based empirical study are formed across ethnic/religious borders - one partner is native Danish and the other originates...... from South Asia (India, Pakistan). Cultural historical psychology forms the background of the theoretical framework of the study, while a combination of intersectionality (Moodley, 2011), everyday life perspective and transnationalism forms the foreground. The lessons learnt for counselling...

  16. Radioactive mixed waste disposal

    International Nuclear Information System (INIS)

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste

  17. Marketing mix and competitiveness

    Directory of Open Access Journals (Sweden)

    Anđelković Slobodan

    2007-01-01

    Full Text Available Competitiveness cannot simply be viewed as a country's ability to export or generate trade surpluses, since these can be brought about at least temporarily by means of artificially lowering the exchange rate and/or compressing domestic expenditures, as has been done in recent years by many DC that have tried to adjust to diminished resource availability. Authors standpoint is that international competitiveness requires creating comparative advantage where it does not exist, and requires action on several levels including an emerging consensus on the importance of macroeconomic policy, role and accountability of the government as well as the imperative of developing and internalizing technology body of knowledge for achieving competitiveness. Particular attention is given to the role and impact of marketing instruments marketing mix.

  18. Neutrino masses and mixing

    International Nuclear Information System (INIS)

    Fogli, G.

    1998-01-01

    The paper presents an analysis of the solar neutrino problem in terms of both Mikheyev-Smirnov-Wolfenstein (MSW) and vacuum neutrino oscillations, with the inclusion of the data collected by the SuperKamiokande experiment during 306.3 days of operation. In particular, the observed energy spectrum of the recoil electrons from 8 B neutrino scattering is discussed in detail and used to constrain the mass-mixing parameter space. Going to the atmospheric neutrino anomaly, the paper performs both a two- and three-flavor analysis of the most recent SuperKamiokande atmospheric neutrino data. The variations of the zenith distributions of ν events in the presence of flavor oscillations are investigated. It is seen that fits to the SK data, with and without the addition of the CHOOZ constrains, strongly limit the parameter space. Detailed bounds in triangle graphs are reported

  19. Mixed Map Labeling

    Directory of Open Access Journals (Sweden)

    Maarten Löffler

    2016-12-01

    Full Text Available Point feature map labeling is a geometric visualization problem, in which a set of input points must be labeled with a set of disjoint rectangles (the bounding boxes of the label texts. It is predominantly motivated by label placement in maps but it also has other visualization applications. Typically, labeling models either use internal labels, which must touch their feature point, or external (boundary labels, which are placed outside the input image and which are connected to their feature points by crossing-free leader lines. In this paper we study polynomial-time algorithms for maximizing the number of internal labels in a mixed labeling model that combines internal and external labels. The model requires that all leaders are parallel to a given orientation θ ∈ [0, 2π, the value of which influences the geometric properties and hence the running times of our algorithms.

  20. MixFit

    DEFF Research Database (Denmark)

    Haller, Toomas; Leitsalu, Liis; Fischer, Krista

    2017-01-01

    Ancestry information at the individual level can be a valuable resource for personalized medicine, medical, demographical and history research, as well as for tracing back personal history. We report a new method for quantitatively determining personal genetic ancestry based on genome-wide data....... Numerical ancestry component scores are assigned to individuals based on comparisons with reference populations. These comparisons are conducted with an existing analytical pipeline making use of genotype phasing, similarity matrix computation and our addition-multidimensional best fitting by Mix......Fit. The method is demonstrated by studying Estonian and Finnish populations in geographical context. We show the main differences in the genetic composition of these otherwise close European populations and how they have influenced each other. The components of our analytical pipeline are freely available...

  1. Application of laser-induced breakdown spectroscopy in carbon ...

    Indian Academy of Sciences (India)

    in carbon sequestration research and development ... design and use of fibre optics make it a suitable technique for real-time ... The currently available methods typically ... Subsequent analysis of the radiation gives qualitative and quantitative ... The soil samples were finely ground, filtered, mixed with carbon powder in.

  2. Acoustic Velocity Data for Clay Bearing Carbonate Rocks

    DEFF Research Database (Denmark)

    Lind, Ida; Shogenova, Alla

    1998-01-01

    Two sets of acoustic data on carbonates were combined to span the porosity interval from below 5% to more than 75%: dolomite and limestone of Paleozoic age from Estonia and mixed sediments from the Caribbean. The carbonate content of the samples ranges from less than 50% to 100%, and it was attem...

  3. Mixed twistor D-modules

    CERN Document Server

    Mochizuki, Takuro

    2015-01-01

    We introduce mixed twistor D-modules and establish their fundamental functorial properties. We also prove that they can be described as the gluing of admissible variations of mixed twistor structures. In a sense, mixed twistor D-modules can be regarded as a twistor version of M. Saito's mixed Hodge modules. Alternatively, they can be viewed as a mixed version of the pure twistor D-modules studied by C. Sabbah and the author. The theory of mixed twistor D-modules is one of the ultimate goals in the study suggested by Simpson's Meta Theorem, and it would form a foundation for the Hodge theory of holonomic D-modules which are not necessarily regular singular.  .

  4. Authoring Immersive Mixed Reality Experiences

    Science.gov (United States)

    Misker, Jan M. V.; van der Ster, Jelle

    Creating a mixed reality experience is a complicated endeavour. From our practice as a media lab in the artistic domain we found that engineering is “only” a first step in creating a mixed reality experience. Designing the appearance and directing the user experience are equally important for creating an engaging, immersive experience. We found that mixed reality artworks provide a very good test bed for studying these topics. This chapter details three steps required for authoring mixed reality experiences: engineering, designing and directing. We will describe a platform (VGE) for creating mixed reality environments that incorporates these steps. A case study (EI4) is presented in which this platform was used to not only engineer the system, but in which an artist was given the freedom to explore the artistic merits of mixed reality as an artistic medium, which involved areas such as the look and feel, multimodal experience and interaction, immersion as a subjective emotion and game play scenarios.

  5. Electrical conductivity of short carbon fibers and carbon black-reinforced chloroprene rubber

    International Nuclear Information System (INIS)

    Khoshniat, A. R.; MirAli, M.; Hemmati, M.; Afshar Taromi, F.; Katbab, A.

    2002-01-01

    Elastomers and plastics are intrinsically insulating materials, but by addition of some conductive particles such as conductive carbon black, carbon fibers and metals, they can change to conductive form. Conductivity of these composites are due to formation of the lattices of conductive filler particles in polymer chains. In this report, conductivity of chloroprene rubber filled with carbon black and carbon fibers as a function of temperature and pressure are studied. Electrical conductivity of chloroprene in a function of temperature and pressure are studied. Electrical conductivity of chloroprene in the presence of carbon black with proper mixing conditions increases to the conductivity level of semiconductors and even in the presence of carbon fibers it increases to the level of a conductor material. Meanwhile, the sensitivity of this compound to heat and pressure rises. Thus these composites have found various applications in the manufacture of heat and pressure sensitive sensors

  6. Determining Σ-Λ mixing

    Energy Technology Data Exchange (ETDEWEB)

    Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Najjar, J. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe (Japan); Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Zanotti, J.M. [Adelaide Univ. (Australia). CSSM, School of Chemistry and Physics

    2014-12-15

    SU2 isospin breaking effects in baryon octet (and decuplet) masses are due to a combination of up and down quark mass differences and electromagnetic effects. These mass differences are small. Between the Sigma and Lambda the mass splitting is much larger, but this is mostly due to their different wavefunctions. However there is now also mixing between these states. We determine the QCD mixing matrix and hence find the mixing angle and mass splitting.

  7. Mixed methods for telehealth research.

    Science.gov (United States)

    Caffery, Liam J; Martin-Khan, Melinda; Wade, Victoria

    2017-10-01

    Mixed methods research is important to health services research because the integrated qualitative and quantitative investigation can give a more comprehensive understanding of complex interventions such as telehealth than can a single-method study. Further, mixed methods research is applicable to translational research and program evaluation. Study designs relevant to telehealth research are described and supported by examples. Quality assessment tools, frameworks to assist in the reporting and review of mixed methods research, and related methodologies are also discussed.

  8. Bilan CarboneR - Implementation

    International Nuclear Information System (INIS)

    Wolff, Aurelie

    2015-01-01

    Bilan Carbone TM , a method for calculating greenhouse gas emissions, was developed to help companies and territorial authorities estimate emissions from their activities or on their territories. After validating the audit perimeter and determining the emission categories to be taken into account, activity data is collected and greenhouse gas emissions are calculated using the tool. Besides accounting greenhouse gas emissions at any given time, the inventory evaluates impact on climate and energy dependence. This helps organizations deal with their emissions by classifying them, implementing action plans to reduce emissions and starting a dynamic process taking into account carbon in their strategic decisions

  9. Effect of Multiwalled Carbon Nanotubes on the Properties of EPDM/NBR Dissimilar Elastomer Blends

    NARCIS (Netherlands)

    Hoikkanen, M.; Poikelispää, M.; Das, A.; Honkanen, M.; Dierkes, Wilma K.; Vuorinen, J.

    2015-01-01

    In the presence of multiwalled carbon nanotubes (MWCNT), polar nitrile-butadiene rubber (NBR) and nonpolar ethylene propylene diene rubber (EPDM) blends were prepared following a melt mixing method. For the preparation of MWCNT filled EPDM/NBR blends, two mixing methods were used: direct mixing and

  10. Effect of doping of multi-walled carbon nanotubes on phenolic based carbon fiber reinforced nanocomposites

    International Nuclear Information System (INIS)

    Saeed, Sadaf; Hakeem, Saira; Faheem, Muhammad; Alvi, Rashid Ahmed; Farooq, Khawar; Hussain, Syed Tajammul; Ahmad, Shahid Nisar

    2013-01-01

    We report on the effect of multi-walled carbon nanotubes (MWCNTs) on different properties of phenolic resin. A low content of MWCNTs (∼ 0.05 wt%) was mixed in phenolic resin and a stable dispersion was achieved by ultrasonication, followed by melt mixing. After curing the characterization of these composites was done by using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infra-red spectroscopy (FTIR). The thermal and ablative properties of carbon fiber reinforced MWCNTs-phenolic nanocomposites were also studied. The addition of MWCNTs showed improvement in thermal stability and ablation properties.

  11. Thin TaC layer produced by ion mixing

    DEFF Research Database (Denmark)

    Barna, Árpád; Kotis, László; Pécz, Béla

    2012-01-01

    in strongly asymmetric ion mixing; the carbon was readily transported to the Ta layer, while the reverse process was much weaker. Because of the asymmetrical transport the C/TaC interface remained sharp independently from the applied fluence. The carbon transported to the Ta layer formed Ta......Ion-beam mixing in C/Ta layered systems was investigated. C 8nm/Ta 12nm and C 20nm/Ta 19nm/C 20nm layer systems were irradiated by Ga+ ions of energy in the range of 2–30keV. In case of the 8nm and 20nm thick C cover layers applying 5–8keV and 20–30keV Ga+ ion energy, respectively resulted...

  12. A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

    Directory of Open Access Journals (Sweden)

    Waris Obitayo

    2012-01-01

    Full Text Available The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.

  13. A gaseous measurement system for carbon-14 dioxide and carbon-14 methane: An analytical methodology to be applied in the evaluation of the carbon-14 dioxide and carbon-14 methane produced via microbial activity in volcanic tuff

    International Nuclear Information System (INIS)

    Dolan, M.M.

    1987-01-01

    The objectives of this study were to develop a gaseous measurement system for the carbon-14 dioxide and carbon-14 methane produced via microbial activity or geochemical action on leachate in tuff; to determine the trapping efficiency of the system for carbon-14 dioxide; to determine the trapping efficiency of the system for carbon-14 methane; to apply the experimentally determined factors regarding the system's trapping efficiency for carbon-14 dioxide and carbon-14 methane to a trapping algorithm to determine the activity of the carbon-14 dioxide and carbon-14 methane in a mixed sample; to determine the minimum detectable activity of the measurement process in picocuries per liter; and to determine the lower limit or detection of the measurement process in counts per minute

  14. Mixing ventilation guide on mixing air distribution design

    CERN Document Server

    Kandzia, Claudia; Kosonen, Risto; Krikor Melikov, Arsen; Nielsen, Peter Vilhelm

    2013-01-01

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection of air diffusers and exhaust openings.

  15. Mixing Ventilation. Guide on mixing air distribution design

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  16. [Characteristics of carbon storage of Inner Mongolia forests: a review].

    Science.gov (United States)

    Yang, Hao; Hu, Zhong-Min; Zhang, Lei-Ming; Li, Sheng-Gong

    2014-11-01

    Forests in Inner Mongolia account for an important part of the forests in China in terms of their large area and high living standing volume. This study reported carbon storage, carbon density, carbon sequestration rate and carbon sequestration potential of forest ecosystems in Inner Mongolia using the biomass carbon data from the related literature. Through analyzing the data of forest inventory and the generalized allometric equations between volume and biomass, previous studies had reported that biomass carbon storage of the forests in Inner Mongolia was about 920 Tg C, which was 12 percent of the national forest carbon storage, the annual average growth rate was about 1.4%, and the average of carbon density was about 43 t · hm(-2). Carbon storage and carbon density showed an increasing trend over time. Coniferous and broad-leaved mixed forest, Pinus sylvestris var. mongolica forest and Betula platyphylla forest had higher carbon sequestration capacities. Carbon storage was reduced due to human activities such as thinning and clear cutting. There were few studies on carbon storage of the forests in Inner Mongolia with focus on the soil, showing that the soil car- bon density increased with the stand age. Study on the carbon sequestration potential of forest ecosystems was still less. Further study was required to examine dynamics of carbon storage in forest ecosystems in Inner Mongolia, i. e., to assess carbon storage in the forest soils together with biomass carbon storage, to compute biomass carbon content of species organs as 45% in the allometric equations, to build more species-specific and site-specific allometric equations including root biomass for different dominant species, and to take into account the effects of climate change on carbon sequestration rate and carbon sequestration potential.

  17. Company Communication Mix

    OpenAIRE

    Švecová, Michaela

    2015-01-01

    Predmetom bakalárskej práce “Komunikačný mix podniku” je analýza súčasného stavu komunikačného mixu vybraného podniku a návrh nového. Práca je rozdelená na teoretickú a praktickú časť. Teoretická časť pojednáva o význame marketingovej komunikácie, popisuje a porovnáva jednotlivé nástroje komunikačného mixu. Úvod praktickej časti popisuje vybranú spoločnosť. Hlavná časť analyzuje a hodnotí súčasné nástroje propagácie. Následuje realizovaný výskum zameraný na spokojnosť zákazníkov. Záverečná ča...

  18. Ocean bio-geophysical modeling using mixed layer-isopycnal general circulation model coupled with photosynthesis process

    Digital Repository Service at National Institute of Oceanography (India)

    Nakamoto, S.; Saito, H.; Muneyama, K.; Sato, T.; PrasannaKumar, S.; Kumar, A.; Frouin, R.

    -chemical system that supports steady carbon circulation in geological time scale in the world ocean using Mixed Layer-Isopycnal ocean General Circulation model with remotely sensed Coastal Zone Color Scanner (CZCS) chlorophyll pigment concentration....

  19. Growth of microbial mixed cultures under anaerobic, alkaline conditions

    International Nuclear Information System (INIS)

    Wenk, M.

    1993-09-01

    Cement and concrete are the most important engineered barrier materials in a repository for low- and intermediate-level waste and thus represent the most significant component of the total disposal inventory. Based on the chemical composition of the concrete used in the repository and the groundwater fluxes in the modelled host rock, it is to be expected that the pH in the near vicinity of the repository could exceed a value of 10.5 for more than a million years. The groundwater in the repository environment also has a limited carbon concentration. Since microorganisms will be present in a repository and can even find suitable living conditions within the waste itself, investigations were carried out in order to establish the extent to which microbial activity is possible under the extreme conditions of the repository near-field. For the investigations, alkalophilic cultures were enriched from samples from alkaline habitats and from Valanginian Marl. Anaerobic bacteria with fermentative, sulfate-reducing and methanogenic metabolism were selected. The growth and activity of the mixed cultures were studied under alkaline conditions and the dependence on pH and carbon concentration determined. All the mixed cultures investigated are alkalophilic. The optimum growth range for the cultures is between pH 9.0 and pH 10.0. The activity limit for the fermentative mixed culture is at pH 12, for the sulfate-reducers at pH 11 and for the methanogens at pH 10.5. Given the limited supply of carbon, the mixed cultures can only grow under slightly alkaline conditions. Only the fermentative cultures are capable of surviving with limited carbon supply at pH 13. (author) 24 figs., 18 tabs., 101 refs

  20. Mixing core material into the envelopes of red grants

    International Nuclear Information System (INIS)

    Deupree, R.G.

    1986-01-01

    A discussion is presented of calculations of four core helium flashes in red giant stars. The starting point for these calculations is a point source explosion on the polar axis of a two-dimensional finite difference grid. The amount of residue of the core helium flash mixed into and above the hydrogen shell is calculated at four temperatures for the elements carbon, oxygen, neon, magnesium, silicon, and sulfur. 7 refs., 1 tab

  1. A cosmic cake mix

    International Nuclear Information System (INIS)

    Grady, Monica; Wright, Ian

    1990-01-01

    Meteorites are the best evidence we have of how the Solar System began. Some types of meteorite have remained almost unchanged since then, unlike rocks on Earth which have been melted and recrystallised into entirely different forms. For many years, cosmologists relied on meteorites to help them reconstruct the complex processes which took place in the earliest part of Solar System history. More recently, researchers have begun to come across puzzling anomalies in the chemical make up of some types of meteorite. Now they have realised that components of these meteorites are the remnants of much older processes that went on even before the Solar System existed. It has been found that some carbon-based meteorites of the chondrite type contain inert gases that pre-date the formation of the Solar System. Thus the theory that the Solar System had been formed from a homogeneous cloud of gas and dust was replaced by the idea that the gas and dust cloud contained traces of material still labelled by where they had come from -supernova, nova or red giantstar. New discoveries and new theories of meteorites are discussed. (author)

  2. Tough ceramic coatings: Carbon nanotube reinforced silica sol-gel

    Science.gov (United States)

    López, A. J.; Rico, A.; Rodríguez, J.; Rams, J.

    2010-08-01

    Silica coatings reinforced with carbon nanotubes were produced via sol-gel route using two mixing techniques of the sol-gel precursors, mechanical and ultrasonic mixing, and dip-coating as deposition process on magnesium alloy substrates. Effective incorporation and distribution of 0.1 wt.% of carbon nanotubes in the amorphous silica matrix of the coatings were achieved using both techniques. Fabrication procedure determines the morphological aspects of the coating. Only mechanical mixing process produced coatings dense and free of defects. Nanoindentation technique was used to examine the influence of the fabrication process in the mechanical features of the final coatings, i.e. indentation fracture toughness, Young's modulus and hardness. A maximum toughening effect of about 24% was achieved in silica coatings reinforced with carbon nanotubes produced by the mechanical mixing route. Scanning electron microscopy investigation revealed that the toughening of these reinforced coatings was mainly due to bridging effect of the reinforcement.

  3. Carbonizing process

    Energy Technology Data Exchange (ETDEWEB)

    1923-11-22

    In the downward distillation of coal, shale, lignite, or the like, the heat is generated by the combustion of liquid or gaseous fuel above the charge the zone of carbonization thus initiated travelling downwards through the charge. The combustible gases employed are preferably those resulting from the process but gases such as natural gas may be employed. The charge is in a moistened and pervious state the lower parts being maintained at a temperature not above 212/sup 0/F until influenced by contact with the carbonization zone and steam may be admitted to increase the yield of ammonia. The combustible gases may be supplied with insufficient air so as to impart to them a reducing effect.

  4. Neutrino mixing in SO(10)

    International Nuclear Information System (INIS)

    Milton, K.; Hama, S.; Nandi, S.; Tanaka, K.

    1980-01-01

    Neutrino mixing angles were computed in terms of upquark mass ratios in a grand unified field theory based on the gauge group SO(10) supplemented by a discrete symmetry. Only large ν/sub μ/ - ν/sub tau/ mixing were found

  5. Mixed-Media File Systems

    NARCIS (Netherlands)

    Bosch, H.G.P.

    1999-01-01

    This thesis addresses the problem of implementing mixed-media storage systems. In this work a mixed-media file system is defined to be a system that stores both conventional (best-effort) file data and real-time continuous-media data. Continuous-media data is usually bulky, and servers storing and

  6. Mixed Waste Working Group report

    International Nuclear Information System (INIS)

    1993-01-01

    The treatment of mixed waste remains one of this country's most vexing environmental problems. Mixed waste is the combination of radioactive waste and hazardous waste, as defined by the Resource Conservation and Recovery Act (RCRA). The Department of Energy (DOE), as the country's largest mixed waste generator, responsible for 95 percent of the Nation's mixed waste volume, is now required to address a strict set of milestones under the Federal Facility Compliance Act of 1992. DOE's earlier failure to adequately address the storage and treatment issues associated with mixed waste has led to a significant backlog of temporarily stored waste, significant quantities of buried waste, limited permanent disposal options, and inadequate treatment solutions. Between May and November of 1993, the Mixed Waste Working Group brought together stakeholders from around the Nation. Scientists, citizens, entrepreneurs, and bureaucrats convened in a series of forums to chart a course for accelerated testing of innovative mixed waste technologies. For the first time, a wide range of stakeholders were asked to examine new technologies that, if given the chance to be tested and evaluated, offer the prospect for better, safer, cheaper, and faster solutions to the mixed waste problem. In a matter of months, the Working Group has managed to bridge a gap between science and perception, engineer and citizen, and has developed a shared program for testing new technologies

  7. Mixing in a Microfluid Device

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Deryabin, Mikhail

    Mixing of fluids in microchannels cannot rely on turbulence since the flow takes place at extremly low Reynolds numbers. Various active and passive devices have been developed to induce mixing in microfluid flow devices. We describe here a model of an active mixer where a transverse periodic flow...

  8. Mixed-Methods Research Methodologies

    Science.gov (United States)

    Terrell, Steven R.

    2012-01-01

    Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

  9. Thermochemistry of mixed explosives

    International Nuclear Information System (INIS)

    Janney, J.L.; Rogers, R.N.

    1982-01-01

    In order to predict thermal hazards of high-energy materials, accurate kinetics constants must be determined. Predictions of thermal hazards for mixtures of high-energy materials require measurements on the mixtures, because interactions among components are common. A differential-scanning calorimeter (DSC) can be used to observe rate processes directly, and isothermal methods enable detection of mechanism changes. Rate-controlling processes will change as components of a mixture are depleted, and the correct depletion function must be identified for each specific stage of a complex process. A method for kinetics measurements on mixed explosives can be demonstrated with Composition B is an approximately 60/40 mixture of RDX and TNT, and is an important military explosive. Kinetics results indicate that the mator process is the decomposition of RDX in solution in TNT with a perturbation caused by interaction between the two components. It is concluded that a combination of chemical kinetics and experimental self-heating procedures provides a good approach to the production of predictive models for thermal hazards of high-energy materials. Systems involving more than one energy-contributing component can be studied. Invalid and dangerous predictive models can be detected by a failure of agreement between prediction and experiment at a specific size, shape, and density. Rates of thermal decomposition for Composition B appear to be modeled adequately for critical-temperature predictions with the following kinetics constants: E = 180.2 kJ mole -1 and Z = 4.62 X 10 16 s -1

  10. Carbon aerogels

    International Nuclear Information System (INIS)

    Berthon-Fabry, S.; Achard, P.

    2003-06-01

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

  11. Mixing-Structure Relationship in Jet-Stirred Reactors

    KAUST Repository

    Ayass, Wassim W.

    2016-05-26

    In this study, measurements were performed to assess the overall mixing in jet-stirred reactors (JSRs) passively agitated by feed nozzles. The reactor diameter, nozzle shape, and nozzle diameter were varied to determine the effects of these geometrical parameters on mixing. The mixing was studied at ambient conditions using laser absorption spectroscopy to follow the exit concentration of a tracer gas, carbon dioxide, after a step change in its input flow. The results indicate that the use of a JSR of diameter D = 40 mm, having inclined or crossed nozzles of diameter d = 1 mm is recommended for low residence times up to 0.4 sec, while at moderate/high residence times 0.5-5 sec the use of a JSR of D = 56 mm and d = 0.3 mm having crossed nozzles is suggested.

  12. Electrochemical treatment of mixed (hazardous and radioactive) wastes

    International Nuclear Information System (INIS)

    Dziewinski, J.; Zawodzinski, C.; Smith, W.H.

    1995-01-01

    Electrochemical treatment technologies for mixed hazardous waste are currently under development at Los Alamos National Laboratory. For a mixed waste containing toxic components such as heavy metals and cyanides in addition to a radioactive component, the toxic components can be removed or destroyed by electrochemical technologies allowing for recovery of the radioactive component prior to disposal of the solution. Mixed wastes with an organic component can be treated by oxidizing the organic compound to carbon dioxide and then recovering the radioactive component. The oxidation can be done directly at the anode or indirectly using an electron transfer mediator. This work describes the destruction of isopropanol, acetone and acetic acid at greater than 90% current efficiency using cobalt +3 or silver +2 as the electron transfer mediator. Also described is the destruction of cellulose based cheesecloth rags with electrochemically generated cobalt +3, at an overall efficiency of approximately 20%

  13. Probabilistic broadcasting of mixed states

    International Nuclear Information System (INIS)

    Li Lvjun; Li Lvzhou; Wu Lihua; Zou Xiangfu; Qiu Daowen

    2009-01-01

    It is well known that the non-broadcasting theorem proved by Barnum et al is a fundamental principle of quantum communication. As we are aware, optimal broadcasting (OB) is the only method to broadcast noncommuting mixed states approximately. In this paper, motivated by the probabilistic cloning of quantum states proposed by Duan and Guo, we propose a new way for broadcasting noncommuting mixed states-probabilistic broadcasting (PB), and we present a sufficient condition for PB of mixed states. To a certain extent, we generalize the probabilistic cloning theorem from pure states to mixed states, and in particular, we generalize the non-broadcasting theorem, since the case that commuting mixed states can be exactly broadcast can be thought of as a special instance of PB where the success ratio is 1. Moreover, we discuss probabilistic local broadcasting (PLB) of separable bipartite states

  14. Multi-Wave Mixing Processes

    CERN Document Server

    Zhang, Yanpeng

    2009-01-01

    "Multi-Wave Mixing Processes - From Ultrafast Polarization Beats to Electromagnetically Induced Transparency" discusses the interactions of efficient multi-wave mixing (MWM) processes enhanced by atomic coherence in multilevel atomic systems. It covers topics in five major areas: attosecond and femtosecond polarization beats of four-wave mixing (FWM) processes; heterodyne detection of FWM, six-wave mixing (SWM) and eight-wave mixing (EWM) processes; Raman and Rayleigh enhanced polarization beats; coexistence and interactions of MWM processes via electromagnetically induced transparency(EIT); multi-dressing MWM processes. The book is intended for researchers, advanced undergraduate and graduate students in Nonlinear Optics. Dr. Yanpeng Zhang is a professor at the Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University. Dr. Min Xiao is a professor of Physics at University of Arkansas, Fayetteville, U.S.A.

  15. Remediating the INEL's buried mixed waste tanks

    International Nuclear Information System (INIS)

    Kuhns, D.J.; Matthern, G.E.; Reese, C.L.

    1996-01-01

    The Idaho National Engineering Laboratory (INEL), formerly the National Reactor Testing Station (NRTS), encompasses 890 square miles and is located in southeast Idaho. In 1949, the United States Atomic Energy Commission, now the Department of Energy (DOE), established the NRTS as a site for the building and testing of nuclear facilities. Wastes generated during the building and testing of these nuclear facilities were disposed within the boundaries of the site. These mixed wastes, containing radionuclides and hazardous materials, were often stored in underground tanks for future disposal. The INEL has 11 buried mixed waste storage tanks regulated under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) ranging in size from 400 to 50,000 gallons. These tanks are constructed of either stainless or carbon steel and are located at 3 distinct geographic locations across the INEL. These tanks have been grouped based on their similarities in an effort to save money and decrease the time required to complete the necessary remediation. Environmental Restoration and Technology Development personnel are teaming in an effort to address the remediation problem systematically

  16. Carbon cycle

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, J; Halbritter, G; Neumann-Hauf, G

    1982-05-01

    This report contains a review of literature on the subjects of the carbon cycle, the increase of the atmospheric CO/sub 2/ concentration and the possible impacts of an increased CO/sub 2/ concentration on the climate. In addition to this survey, the report discusses the questions that are still open and the resulting research needs. During the last twenty years a continual increase of the atmospheric carbon dioxide concentration by about 1-2 ppm per years has been observed. In 1958 the concentration was 315 ppm and this increased to 336 ppm in 1978. A rough estimate shows that the increase of the atmospheric carbon dioxide concentration is about half of the amount of carbon dioxide added to the atmosphere by the combustion of fossil fuels. Two possible sinks for the CO/sub 2/ released into the atmosphere are known: the ocean and the biota. The role of the biota is, however, unclear, since it can act both as a sink and as a source. Most models of the carbon cycle are one-dimensional and cannot be used for accurate predictions. Calculations with climate models have shown that an increased atmospheric CO/sub 2/ concentration leads to a warming of the earth's surface and lower atmosphere. Calculations show that a doubling of the atmospheric CO/sub 2/-concentration would lead to a net heating of the lower atmosphere and earth's surface by a global average of about 4 W m/sup -2/. Greater uncertainties arise in estimating the change in surface temperature resulting from this change in heating rate. It is estimated that the global average annual surface temperature would change between 1.5 and 4.5 K. There are, however, latitudinal and seasonal variations of the impact of increased CO/sub 2/ concentration. Other meteorological variables (e.g. precipitation, wind speed etc.) would also be changed. It appears that the impacts of the other products of fossil fuel combustion are unlikely to counteract the impacts of CO/sub 2/ on the climate.

  17. Mediated electrochemical oxidation of mixed wastes

    International Nuclear Information System (INIS)

    Chiba, Z.

    1993-04-01

    The Mediated Electrochemical Oxidation (MEO) process was studied for destroying low-level combustible mixed wastes at Rocky Flats Plant. Tests were performed with non-radioactive surrogate materials: Trimsol for contaminated cutting oils, and reagent-grade cellulose for contaminated cellulosic wastes. Extensive testing was carried out on Trimsol in both small laboratory-scale apparatus and on a large-scale system incorporating an industrial-size electrochemical cell. Preliminary tests were also carried out in the small-scale system with cellulose. Operating and system parameters that were studied were: use of a silver-nitric acid versus a cobalt-sulfuric acid system, effect of electrolyte temperature, effect of acid concentration, and effect of current density. Destruction and coulombic efficiencies were calculated using data obtained from continuous carbon dioxide monitors and total organic carbon (TOC) analysis of electrolyte samples. For Trimsol, the best performance was achieved with the silver-nitrate system at high acid concentrations, temperatures, and current densities. Destruction efficiencies of 99% or greater, and coulombic efficiencies up to 70% were obtained. For the cellulose, high destruction efficiencies and reasonable coulombic efficiencies were obtained for both silver-nitrate and cobalt-sulfate systems

  18. Turbidity Current Head Mixing

    Science.gov (United States)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    coastal diffusion using image analysis. Applied Scientific Research 59,.191-204. 1998. [5] J.M. Redondo. Turbulent mixing in the Atmosphere and Ocean. Fluid Physics. 584-597. World Scientific. New York. 1994

  19. Compressibility effects on turbulent mixing

    Science.gov (United States)

    Panickacheril John, John; Donzis, Diego

    2016-11-01

    We investigate the effect of compressibility on passive scalar mixing in isotropic turbulence with a focus on the fundamental mechanisms that are responsible for such effects using a large Direct Numerical Simulation (DNS) database. The database includes simulations with Taylor Reynolds number (Rλ) up to 100, turbulent Mach number (Mt) between 0.1 and 0.6 and Schmidt number (Sc) from 0.5 to 1.0. We present several measures of mixing efficiency on different canonical flows to robustly identify compressibility effects. We found that, like shear layers, mixing is reduced as Mach number increases. However, data also reveal a non-monotonic trend with Mt. To assess directly the effect of dilatational motions we also present results with both dilatational and soleniodal forcing. Analysis suggests that a small fraction of dilatational forcing decreases mixing time at higher Mt. Scalar spectra collapse when normalized by Batchelor variables which suggests that a compressive mechanism similar to Batchelor mixing in incompressible flows might be responsible for better mixing at high Mt and with dilatational forcing compared to pure solenoidal mixing. We also present results on scalar budgets, in particular on production and dissipation. Support from NSF is gratefully acknowledged.

  20. Chlorophyll modulation of mixed layer thermodynamics in a mixed ...

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    in a mixed-layer isopycnal General Circulation Model – An ... three dimensional ocean circulation theory combined with solar radiation transfer process. 1. .... temperature decrease compared with simulation without chlorophyll (bottom panel).

  1. Carbons and carbon supported catalysts in hydroprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, Edward

    2009-07-01

    This book is a comprehensive summary of recent research in the field and covers all areas of carbons and carbon materials. The potential application of carbon supports, particularly those of carbon black (CB) and activated carbon (AC) in hydroprocessing catalysis are covered. Novel carbon materials such as carbon fibers and carbon nano tubes (CNT) are also covered, including the more recent developments in the use of fullerenes in hydroprocessing applications. Although the primary focus of this book is on carbons and carbon supported catalysts, it also identifies the difference in the effect of carbon supports compared with the oxidic supports, particularly that of the Al{sub 2}O{sub 3}. The difference in catalyst activity and stability was estimated using both model compounds and real feeds under variable conditions. The conditions applied during the preparation of carbon supported catalysts are also comprehensively covered and include various methods of pretreatment of carbon supports to enhance catalyst performance. The model compounds results consistently show higher hydrodesulfurization and hydrodeoxygenation activities of carbon supported catalysts than that of the Al{sub 2}O{sub 3} supported catalysts. Also, the deactivation of the former catalysts by coke deposition was much less evident. Chapter 6.3.1.3 is on carbon-supported catalysts: coal-derived liquids.

  2. [Marketing mix in health service].

    Science.gov (United States)

    Ameri, Cinzia; Fiorini, Fulvio

    2015-01-01

    The marketing mix is the combination of the marketing variables that a firm employs with the purpose to achieve the expected volume of business within its market. In the sale of goods, four variables compose the marketing mix (4 Ps): Product, Price, Point of sale and Promotion. In the case of providing services, three further elements play a role: Personnel, Physical Evidence and Processes (7 Ps). The marketing mix must be addressed to the consumers as well as to the employees of the providing firm. Furthermore, it must be interpreted as employees ability to satisfy customers (interactive marketing).

  3. Generalized, Linear, and Mixed Models

    CERN Document Server

    McCulloch, Charles E; Neuhaus, John M

    2011-01-01

    An accessible and self-contained introduction to statistical models-now in a modernized new editionGeneralized, Linear, and Mixed Models, Second Edition provides an up-to-date treatment of the essential techniques for developing and applying a wide variety of statistical models. The book presents thorough and unified coverage of the theory behind generalized, linear, and mixed models and highlights their similarities and differences in various construction, application, and computational aspects.A clear introduction to the basic ideas of fixed effects models, random effects models, and mixed m

  4. Carbon classified?

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    2012-01-01

    . Using an actor- network theory (ANT) framework, the aim is to investigate the actors who bring together the elements needed to classify their carbon emission sources and unpack the heterogeneous relations drawn on. Based on an ethnographic study of corporate agents of ecological modernisation over...... a period of 13 months, this paper provides an exploration of three cases of enacting classification. Drawing on ANT, we problematise the silencing of a range of possible modalities of consumption facts and point to the ontological ethics involved in such performances. In a context of global warming...

  5. Carbon Footprints

    OpenAIRE

    Rahel Aichele; Gabriel Felbermayr

    2011-01-01

    Lässt sich der Beitrag eines Landes zum weltweiten Klimaschutz an der Veränderung seines CO2-Ausstoßes messen, wie es im Kyoto-Abkommen implizit unterstellt wird? Oder ist aufgrund der Bedeutung des internationalen Güterhandels der Carbon Footprint – der alle CO2-Emissionen erfasst, die durch die Absorption (d.h. Konsum und Investitionen) eines Landes entstehen – das bessere Maß? Die Autoren erstellen eine Datenbank mit den Footprints von 40 Ländern für den Zeitraum 1995–2007. Die deskriptive...

  6. Vibrationally Excited Carbon Monoxide Produced via a Chemical Reaction Between Carbon Vapor and Oxygen

    Science.gov (United States)

    Jans, Elijah R.; Eckert, Zakari; Frederickson, Kraig; Rich, Bill; Adamovich, Igor V.

    2017-06-01

    Measurements of the vibrational distribution function of carbon monoxide produced via a reaction between carbon vapor and molecular oxygen has shown a total population inversion on vibrational levels 4-7. Carbon vapor, produced using an arc discharge to sublimate graphite, is mixed with an argon oxygen flow. The excited carbon monoxide is vibrationally populated up to level v=14, at low temperatures, T=400-450 K, in a collision-dominated environment, 15-20 Torr, with total population inversions between v=4-7. The average vibrational energy per CO molecule formed by the reaction is 0.6-1.2 eV/molecule, which corresponds to 10-20% of the reaction enthalpy. Kinetic modeling of the flow reactor, including state specific vibrational processes, was performed to infer the vibrational distribution of the products of the reaction. The results show viability of developing of a new chemical CO laser from the reaction of carbon vapor and oxygen.

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  8. Minimal modification to tribimaximal mixing

    International Nuclear Information System (INIS)

    He Xiaogang; Zee, A.

    2011-01-01

    We explore some ways of minimally modifying the neutrino mixing matrix from tribimaximal, characterized by introducing at most one mixing angle and a CP violating phase thus extending our earlier work. One minimal modification, motivated to some extent by group theoretic considerations, is a simple case with the elements V α2 of the second column in the mixing matrix equal to 1/√(3). Modifications by keeping one of the columns or one of the rows unchanged from tribimaximal mixing all belong to the class of minimal modification. Some of the cases have interesting experimentally testable consequences. In particular, the T2K and MINOS collaborations have recently reported indications of a nonzero θ 13 . For the cases we consider, the new data sharply constrain the CP violating phase angle δ, with δ close to 0 (in some cases) and π disfavored.

  9. Mixed Fluid Conditions: Capillary Phenomena

    KAUST Repository

    Santamarina, Carlos; Sun, Zhonghao

    2017-01-01

    Mixed fluid phenomena in porous media have profound implications on soil-atmosphere interaction, energy geotechnology, environmental engineering and infrastructure design. Surface tension varies with pressure, temperature, solute concentration

  10. Mixed methods research for TESOL

    CERN Document Server

    Brown, James; Farr, Fiona

    2014-01-01

    Defining and discussing the relevance of theoretical and practical issues involved in mixed methods research. Covering the basics of research methodology, this textbook shows you how to choose and combine quantitative and qualitative research methods to b

  11. Is the tribimaximal mixing accidental?

    International Nuclear Information System (INIS)

    Abbas, Mohammed; Smirnov, A. Yu.

    2010-01-01

    The tribimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on the structure of the neutrino mass matrix and on the underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM-mass relations. As a result, the mass matrix may have an 'anarchical' structure with random values of elements or it may have some symmetry that differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain 'flavor alignment' as well as hierarchical matrices with a two-component structure, where the dominant and subdominant contributions have different symmetries. This opens up new approaches to understanding the lepton mixing.

  12. Raman Scattering in a New Carbon Material

    Science.gov (United States)

    Voronov, O. A.; Street, K. W., Jr.

    2010-01-01

    Samples of a new carbon material, Diamonite-B, were fabricated under high pressure from a commercial carbon black--identified as mixed fullerenes. The new material is neither graphite-like nor diamond-like, but exhibits electrical properties close to graphite and mechanical properties close to diamond. The use of Raman spectroscopy to investigate the vibrational dynamics of this new carbon material and to provide structural characterization of its short-, medium- and long-range order is reported. We also provide the results of investigations of these samples by high-resolution electron microscopy and X-ray diffraction. Hardness, electrical conductivity, thermal conductivity and other properties of this new material are compared with synthetic graphite-like and diamond-like materials, two other phases of synthetic bulk carbon.

  13. Enhanced solubilization of curcumin in mixed surfactant vesicles.

    Science.gov (United States)

    Kumar, Arun; Kaur, Gurpreet; Kansal, S K; Chaudhary, Ganga Ram; Mehta, S K

    2016-05-15

    Self-assemblies of equimolar double and single chain mixed ionic surfactants, with increasing numbers of carbon atoms of double chain surfactant, were analyzed on the basis of fluorescence and conductivity results. Attempts were also made to enhance the solubilization of curcumin in aqueous equimolar mixed surfactant systems. Mixed surfactant assembly was successful in retarding the degradation of curcumin in alkaline media (only 25-28 40% degraded in 10h at pH 13). Fluorescence spectroscopy and fluorescence quenching methods were employed to predict the binding position and mechanism of curcumin with self-assemblies. Results indicate that the interactions take place according to both dynamic and static quenching mechanisms and curcumin was distributed in a palisade layer of mixed aggregates. Antioxidant activity (using DPPH radical) and biocompatibility (using calf-thymus DNA) of curcumin-loaded mixed surfactant formulations were also evaluated. The prepared systems improved the stability, solubility and antioxidant activity of curcumin and additionally are biocompatible. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Estimating the Biodegradation Kinetics by Mixed Culture Degrading Pyrene (Pyr

    Directory of Open Access Journals (Sweden)

    B. S. U. Ibn Abubakar

    2017-02-01

    Full Text Available Biodegradation and kinetics of Pyrene (Pyr degradation by a mixed culture previously isolated from hydrocarbon-polluted soil were conducted. Preliminary investigation on environmental factors affecting the degradation of Pyr such as temperature, pH and concentrations of Pyr was performed. These factors were optimised and established in aqueous experiments. In order to develop kinetics of Pyr degradation, an optimum temperature of 30oC and pH of 7.0 was used. Biodegradation kinetics was carried out, at first, using higher concentration between (100-700 ppm as sole source of carbon in mineral salt medium (MSM supplemented with 0.1% yeast extract. The result indicated that a range of concentration between (100-700 ppm inhibits the performance of the mixed culture. A concentration range between (10-100 ppm did not inhibit the growth of the mixed culture. A First-order rate constant, k was higher (0.0487 mg/lh with a substrate concentration of 20 ppm than other concentrations. The average degradation rate constant is 0.0029 mg/Lh for all the concentrations tested. This indicated that the mixed culture could degrade over 0.0696 ppm of Pyr per day. It also confirmed that kinetics of microbial degradation was partially fitted into Monod model. The data can be used to estimate biodegradation of Pyr by a mixed culture and preliminarily estimation of degradation rates.

  15. Can small zooplankton mix lakes?

    OpenAIRE

    Simoncelli, S.; Thackeray, S.J.; Wain, D.J.

    2017-01-01

    The idea that living organisms may contribute to turbulence and mixing in lakes and oceans (biomixing) dates to the 1960s, but has attracted increasing attention in recent years. Recent modeling and experimental studies suggest that marine organisms can enhance turbulence as much as winds and tides in oceans, with an impact on mixing. However, other studies show opposite and contradictory results, precluding definitive conclusions regarding the potential importance of biomixing. For lakes, on...

  16. Mix-and-match holography

    KAUST Repository

    Peng, Yifan; Dun, Xiong; Sun, Qilin; Heidrich, Wolfgang

    2017-01-01

    target images into pairs of front and rear phase-distorting surfaces. Different target holograms can be decoded by mixing and matching different front and rear surfaces under specific geometric alignments. Our approach, which we call mixWe derive a detailed image formation model for the setting of holographic projection displays, as well as a multiplexing method based on a combination of phase retrieval methods and complex matrix factorization. We demonstrate several application scenarios in both simulation and physical prototypes.

  17. Promocja a marketing-mix

    OpenAIRE

    Cyrson, Edward F.

    1994-01-01

    Many companies have often forgotten that promotion is an element of marketing-mix. Therelore their promotional campain has not always been as effective as it could be. In designing and developing marketing communication one should consider all elements of marketing-mix as well as all promotional tools. They together create a promotional system in which all the elements are Mutually reinforcing and give the system the most efficient and effective power. The major thrust of promo...

  18. AECL's mixed waste management program

    International Nuclear Information System (INIS)

    Peori, R.; Hulley, V.

    2006-01-01

    Every nuclear facility has it, they wish that they didn't but they have generated and do possess m ixed waste , and until now there has been no permanent disposition option; it has been for the most been simply maintained in interim storage. The nuclear industry has been responsibly developing permanent solutions for solid radioactive waste for over fifty years and for non-radioactive, chemically hazardous waste, for the last twenty years. Mixed waste (radioactive and chemically hazardous waste) however, because of its special, duo-hazard nature, has been a continuing challenge. The Hazardous Waste and Segregation Program (HW and SP) at AECL's CRL has, over the past ten years, been developing solutions to deal with their own in-house mixed waste and, as a result, have developed solutions that they would like to share with other generators within the nuclear industry. The main aim of this paper is to document and describe the early development of the solutions for both aqueous and organic liquid wastes and to advertise to other generators of this waste type how these solutions can be implemented to solve their mixed waste problems. Atomic Energy of Canada Limited (AECL) and in particular, CRL has been satisfactorily disposing of mixed waste for the last seven years. CRL has developed a program that not only disposes of mixed waste, but offers a full service mixed waste management program to customers within Canada (that could eventually include U.S. sites as well) that has developed the experience and expertise to evaluate and optimize current practices, dispose of legacy inventories, and set up an efficient segregation system to reduce and effectively manage, both the volumes and expense of, the ongoing generation of mixed waste for all generators of mixed waste. (author)

  19. Trading forest carbon

    Science.gov (United States)

    The nature of carbon in forests is discussed from the perspective of carbon trading. Carbon inventories, specifically in the area of land use and forestry are reviewed for the Pacific Northwest. Carbon turnover in forests is discussed as it relates to carbon sequestration. Scient...

  20. Overview of mixed waste issues

    International Nuclear Information System (INIS)

    Piciulo, P.L.; Bowerman, B.S.; Kempf, C.R.; MacKenzie, D.R.; Siskind, B.

    1986-01-01

    Based on BNL's study it was concluded that there are LLWs which contain chemically hazardous components. Scintillation liquids may be considered an EPA listed hazardous waste and are, therefore, potential mixed wastes. Since November, 1985 no operating LLW disposal site will accept these wastes for disposal. Unless such wastes contain de minimis quantities of radionuclides, they cannot be disposed of at an EPA an EPA permitted site. Currently generators of LSC wastes can ship de minimis wastes to be burned at commercial facilities. Oil wastes will also eventually be an EPA listed waste and thus will have to be considered a potential radioactive mixed wasted unless NRC establishes de minimis levels of radionuclides below which oils can be managed as hazardous wastes. Regarding wastes containing lead metal there is some question as to the extent of the hazard posed by lead disposed in a LLW burial trench. Chromium-containing wastes would have to be tested to determine whether they are potential mixed wastes. There may be other wastes that are mixed wastes; the responsibility for determining this rests with the waste generator. It is believed that there are management options for handling potential mixed wastes but there is no regulatory guidance. BNL has identified and evaluated a variety of treatment options for the management of potential radioactive mixed wastes. The findings of that study showed that application of a management option with the purpose of addressing EPA concern can, at the same time, address stabilization and volume reduction concerns of NRC

  1. Mixed waste treatment using the ChemChar thermolytic detoxification technique

    Energy Technology Data Exchange (ETDEWEB)

    Kuchynka, D. [Mirage Systems, Sunnyvale, CA (United States)

    1995-10-01

    The diversity of mixed waste matrices contained at Department of Energy sites that require treatment preclude a single, universal treatment technology capable of handling sludges, solids, heterogeneous debris, aqueous and organic liquids and soils. This report describes the ChemChar thermolytic detoxification process. The process is a thermal, chemically reductive technology that converts the organic portion of mixed wastes to a synthesis gas, while simultaneously absorbing volatile inorganics on a carbon-based char.

  2. Argonne National Laboratory's photo-oxidation organic mixed waste treatment system - installation and startup testing

    International Nuclear Information System (INIS)

    Shearer, T.L.; Nelson, R.A.; Torres, T.; Conner, C.; Wygmans, D.

    1997-01-01

    This paper describes the installation and startup testing of the Argonne National Laboratory (ANL-E) Photo-Oxidation Organic Mixed Waste Treatment System. This system will treat organic mixed (i.e., radioactive and hazardous) waste by oxidizing the organics to carbon dioxide and inorganic salts in an aqueous media. The residue will be treated in the existing radwaste evaporators. The system is installed in the Waste Management Facility at the ANL-E site in Argonne, Illinois. 1 fig

  3. Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

    Science.gov (United States)

    Marinov, I.; Gnanadesikan, A.

    2011-02-01

    The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation result in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

  4. New Hampshire binder and mix review.

    Science.gov (United States)

    2012-08-01

    This review was initiated to compare relative rut testing and simple performance tests (now known as Asphalt Mix : Performance Tests) for the New Hampshire inch mix with 15% Recycled Asphalt Pavement (RAP). The tested mixes were : made from ...

  5. Performance life of HMA mixes : final report.

    Science.gov (United States)

    2016-01-01

    A number of hot mix asphalt (HMA) types, such as permeable friction course (PFC), stone mastic asphalts : (SMA), performance design mixes and conventional dense graded mixes are currently used to construct or overlay : roads. One of the important inp...

  6. Mixed-mode modelling mixing methodologies for organisational intervention

    CERN Document Server

    Clarke, Steve; Lehaney, Brian

    2001-01-01

    The 1980s and 1990s have seen a growing interest in research and practice in the use of methodologies within problem contexts characterised by a primary focus on technology, human issues, or power. During the last five to ten years, this has given rise to challenges regarding the ability of a single methodology to address all such contexts, and the consequent development of approaches which aim to mix methodologies within a single problem situation. This has been particularly so where the situation has called for a mix of technological (the so-called 'hard') and human­ centred (so-called 'soft') methods. The approach developed has been termed mixed-mode modelling. The area of mixed-mode modelling is relatively new, with the phrase being coined approximately four years ago by Brian Lehaney in a keynote paper published at the 1996 Annual Conference of the UK Operational Research Society. Mixed-mode modelling, as suggested above, is a new way of considering problem situations faced by organisations. Traditional...

  7. Flexural Properties of Activated Carbon Filled Epoxy Nano composites

    International Nuclear Information System (INIS)

    Khalil, H.P.S.A.; Khalil, H.P.S.A.; Alothman, O.Y.; Paridah, M.T.; Zainudin, E.S.

    2014-01-01

    Activated carbon (AC) filled epoxy nano composites obtained by mixing the desired amount of nano AC viz., bamboo stem, oil palm empty fruit bunch, and coconut shell from agricultural biomass with the epoxy resin. Flexural properties of activated carbons filled epoxy nano composites with 1 %, and 5 % filler loading were measured. In terms of flexural strength and modulus, a significant increment was observed with addition of 1 % vol and 5 % vol nano-activated carbon as compared to neat epoxy. The effect of activated carbon treated by two chemical agents (potassium hydroxide and phosphoric acid) on the flexural properties of epoxy nano composites were also investigated. Flexural strength of activated carbon-bamboo stem, activated carbon-oil palm, and activated carbon-coconut shell reinforced epoxy nano composites showed almost same value in case of 5 % potassium hydroxide activated carbon. Flexural strength of potassium hydroxide activated carbon-based epoxy nano composites was higher than phosphoric acid activated carbon. The flexural toughness of both the potassium hydroxide and phosphoric acid activated carbon reinforced composites range between 0.79 - 0.92 J. It attributed that developed activated carbon filled epoxy nano composites can be used in different applications. (author)

  8. Different rays of sunlight: Understanding information disclosure and carbon transparency

    International Nuclear Information System (INIS)

    Matisoff, Daniel C.

    2013-01-01

    This study assesses the effectiveness of two types information disclosure programs – state-based mandatory carbon reporting programs and the voluntary Carbon Disclosure Project, which uses investor pressure to push firms to disclose carbon emissions and carbon management strategies. I match firms in each program to control groups of firms that have not participated in each program. Using panel data methods and a difference in differences specification, I measure the impact of each program on plant-level carbon emissions, plant-level carbon intensity, and plant level output. I find that neither program has generated an impact on plant-level carbon emissions, emissions intensity, or output. Placing this study in contrast with others that demonstrate improvements from mandatory information disclosure, these results suggest that how information is reported to stakeholders has important implications for program effectiveness. - Highlights: ► This article evaluates the Carbon Disclosure Project and state carbon reporting requirements. ► Evaluation is conducted with propensity score matching and difference-in-differences. ► State Disclosure Programs fail to lead power plants to reduce carbon dioxide emissions. ► The Carbon Disclosure Project leads to decreases in carbon emissions and electricity output. ► Information disclosure and transparency may be important part of policy mix but have limitations

  9. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Education Centers Carbon Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, ... Install one and check its batteries regularly. View Information About CO Alarms Other CO Topics Safety Tips ...

  10. Global Carbon Budget 2017

    NARCIS (Netherlands)

    Le Quere, Corinne; Andrew, Robbie M.; Friedlingstein, Pierre; Sitch, Stephen; Pongratz, Julia; Manning, Andrew C.; Korsbakken, Jan Ivar; Peters, Glen P.; Canadell, Josep G.; Jackson, Robert B.; Boden, Thomas A.; Tans, Pieter P.; Andrews, Oliver D.; Arora, Vivek K.; Bakker, Dorothee C. E.; Barbero, Leticia; Becker, Meike; Betts, Richard A.; Bopp, Laurent; Chevallier, Frederic; Chini, Louise P.; Ciais, Philippe; Cosca, Catherine E.; Cross, Jessica; Currie, Kim; Gasser, Thomas; Harris, Ian; Hauck, Judith; Haverd, Vanessa; Houghton, Richard A.; Hunt, Christopher W.; Hurtt, George; Ilyina, Tatiana; Jain, Atul K.; Kato, Etsushi; Kautz, Markus; Keeling, Ralph F.; Goldewijk, Kees Klein; Koertzinger, Arne; Landschuetzer, Peter; Lefevre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lima, Ivan; Lombardozzi, Danica; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M. S.; Munro, David R.; Nabel, Julia E. M. S.; Nakaoka, Shin-ichiro; Nojiri, Yukihiro; Padin, X. Antonio; Peregon, Anna; Pfeil, Benjamin; Pierrot, Denis; Poulter, Benjamin; Rehder, Gregor; Reimer, Janet; Roedenbeck, Christian; Schwinger, Jorg; Seferian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Tian, Hanqin; Tilbrook, Bronte; Tubiello, Francesco N.; van der Laan-Luijkx, Ingrid T.; van der Werf, Guido R.; van Heuven, Steven; Viovy, Nicolas; Vuichard, Nicolas; Walker, Anthony P.; Watson, Andrew J.; Wiltshire, Andrew J.; Zaehle, Soenke; Zhu, Dan

    2018-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere - the "global carbon budget" - is important to better understand the global carbon cycle, support the development of climate policies, and project

  11. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Education Safety Education Centers Carbon Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, also known as CO, is called the " ...

  12. Flexible and conductive waste tire-derived carbon/polymer composite paper as pseudocapacitive electrode

    Science.gov (United States)

    Naskar, Amit K.; Paranthaman, Mariappan Parans; Boota, Muhammad; Gogotsi, Yury

    2018-04-10

    A method of making a supercapacitor from waste tires, includes the steps of providing rubber pieces and contacting the rubber pieces with a sulfonation bath to produce sulfonated rubber; pyrolyzing the sulfonated rubber to produce a tire-derived carbon composite comprising carbon black embedded in rubber-derived carbon matrix comprising graphitized interface portions; activating the tire-derived carbon composite by contacting the tire-derived carbon composite with a specific surface area-increasing composition to increase the specific surface area of the carbon composite to provide an activated tire-derived carbon composite; and, mixing the activated tire-derived carbon composite with a monomer and polymerizing the monomer to produce a redox-active polymer coated, activated tire-derived carbon composite. The redox-active polymer coated, activated tire-derived carbon composite can be formed into a film. An electrode and a supercapacitor are also disclosed.

  13. Carbon dioxide problem: solution by technical countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Bach, W

    1978-02-15

    A rough assessment indicates that anthropogenic influences might raise the mean global surface temperature by 0.8 to 1.2 C in 2000 AD and by 2 to 4 C in 2050 AD. The rapidly increasing levels of atmospheric carbon dioxide are largely responsible for this warming trend. A variety of measures for the reduction of carbon dioxide emissions is presented. One promising approach is to work out a world-wide energy mix that can counteract a temperature increase. (In German)

  14. The carbonate complexation of plutonium(IV)

    International Nuclear Information System (INIS)

    Hobart, D.E.; Palmer, P.D.; Newton, T.W.

    1985-01-01

    Plutonium(IV) carbonate complexes are expected to be of particular importance in typical groundwaters at the Yucca Mountain site of the candidate nuclear waste repository being studied by the Nevada Nuclear Waste Storage Investigations Project. The chemistry of these complexes is also important in the areas of nuclear fuel reprocessing and purification, actinide separations, and environmental studies. This report describes initial experiments performed to determine the identity and equilibrium quotients of plutonium(IV) carbonate complexes. These experiments were performed at pH values between 7.2 and 9.6 using a spectrophotometric method. In addition, a brief review of the published literature on Pu(IV) carbonate complexes is presented. Since Pu(IV) exhibits low solubility in the near-neutral pH range, a complex-competition reaction where citrate ligands compete with carbonate ions for the plutonium will be employed. This will permit us to study the pure carbonate system; study the mixed carbonate/citrate system, and confirm and extend the literature work on the pure citrate system. The current experiments have demonstrated the existence of at least three distinct species in the pH region studied. This work will continue in the extended study of the pure citrate system, followed by the investigation of the citrate/carbonate complex/competition reaction. 9 refs., 4 figs., 2 tabs

  15. Optimal Energy Mix with Renewable Portfolio Standards in Korea

    Directory of Open Access Journals (Sweden)

    Zong Woo Geem

    2016-05-01

    Full Text Available Korea is a heavily energy-dependent country whose primary energy consumption ranks ninth in the world. However, at the same time, it promised to reduce carbon emission and planned to use more renewable energy. Thus, the objective of this study is to propose an optimal energy mix planning model in electricity generation from various energy sources, such as gas, coal, nuclear, hydro, wind, photovoltaic, and biomass, which considers more renewable and sustainable portions by imposing governmental regulation named renewable portfolio standard (RPS. This optimization model minimizes various costs such as construction cost, operation and management cost, fuel cost, and carbon emission cost while satisfying minimal demand requirement, maximal annual installation potential, and renewable portfolio standard constraints. Results showed that this optimization model could successfully generate energy mix plan from 2012 to 2030 while minimizing the objective costs and satisfying all the constraints. Therefore, this optimization model contributes more efficient and objective method to the complex decision-making process with a sustainability option. This proposed energy mix model is expected to be applied not only to Korea, but also to many other countries in the future for more economical planning of their electricity generation while affecting climate change less.

  16. Making Activated Carbon by Wet Pressurized Pyrolysis

    Science.gov (United States)

    Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

    2006-01-01

    A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

  17. Integral Ring Carbon-Carbon Piston

    Science.gov (United States)

    Northam, G. Burton (Inventor)

    1999-01-01

    An improved structure for a reciprocating internal combustion engine or compressor piston fabricate from carbon-carbon composite materials is disclosed. An integral ring carbon-carbon composite piston, disclosed herein, reduces the need for piston rings and for small clearances by providing a small flexible, integral component around the piston that allows for variation in clearance due to manufacturing tolerances, distortion due to pressure and thermal loads, and variations in thermal expansion differences between the piston and cylinder liner.

  18. Managing a mixed waste program

    International Nuclear Information System (INIS)

    Koch, J.D.

    1994-01-01

    IT Corporation operates an analytical laboratory in St. Louis capable of analyzing environmental samples that are contaminated with both chemical and radioactive materials. Wastes generated during these analyses are hazardous in nature; some are listed wastes others exhibit characteristic hazards. When the original samples contain significant quantities of radioactive material, the waste must be treated as a mixed waste. A plan was written to document the waste management program describing the management of hazardous, radioactive and mixed wastes. This presentation summarizes the methods employed by the St. Louis facility to reduce personnel exposures to the hazardous materials, minimize the volume of mixed waste and treat the materials prior to disposal. The procedures that are used and the effectiveness of each procedure will also be discussed. Some of the lessons that have been learned while dealing with mixed wastes will be presented as well as the solutions that were applied. This program has been effective in reducing the volume of mixed waste that is generated. The management program also serves as a method to manage the costs of the waste disposal program by effectively segregating the different wastes that are generated

  19. Mixed waste, preparing for 1996

    International Nuclear Information System (INIS)

    Duke, D.L.

    1995-01-01

    The Environmental Protection Agency has recently approved an extension to the enforcement policy for the storage of restricted mixed waste. Under this policy, EPA assigns a reduced enforcement priority to violations of the 40CFR268.50 prohibition on storage of restricted waste. Eligibility for the lower enforcement priority afforded by the policy is subject to specified conditions. The recent extension is for a two year period, and agency personnel have advised that it may be difficult to extend the enforcement policy again. This paper reviews anticipated changes in mixed waste treatment and disposal capabilities. Types of mixed waste that may be generated, or in storage, at commercial nuclear power plants are identified. This information is evaluated to determine if the two year extension in the storage enforcement policy will be adequate for the nuclear power industry to treat or dispose of the mixed waste inventories that are identified, and if not, where potential problem areas may reside. Recommendations are then made on mixed waste management strategies

  20. Penelitian pengaruh campuran carbon black dan china clay terhadap sifat tegangan putus dan kekerasan karet vulkanisat

    Directory of Open Access Journals (Sweden)

    Supraptiningsih Supraptiningsih

    1999-07-01

    Full Text Available It has been done a research of the influence of mixed carbon black and hardness properties on the vulcanization of rubber. It has been made with additive of carbon black and china clay mixed, in total variation. The result is seen that total variation of carbon black and china clay not influence to tensile strength, but their interacton can do it. The hardness of vulcanization of rubber will be influence by total variation of carbon black china clay anad their interaction.