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Sample records for gas basis biomethane

  1. Life cycle greenhouse gas impacts of ethanol, biomethane and limonene production from citrus waste

    NASA Astrophysics Data System (ADS)

    Pourbafrani, Mohammad; McKechnie, Jon; MacLean, Heather L.; Saville, Bradley A.

    2013-03-01

    The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA

  2. A feasibility study on the bioconversion of CO2 and H2 to biomethane by gas sparging through polymeric membranes.

    PubMed

    Díaz, I; Pérez, C; Alfaro, N; Fdz-Polanco, F

    2015-06-01

    In this study, the potential of a pilot hollow-fiber membrane bioreactor for the conversion of H2 and CO2 to CH4 was evaluated. The system transformed 95% of H2 and CO2 fed at a maximum loading rate of 40.2 [Formula: see text] and produced 0.22m(3) of CH4 per m(3) of H2 fed at thermophilic conditions. H2 mass transfer to the liquid phase was identified as the limiting step for the conversion, and kLa values of 430h(-1) were reached in the bioreactor by sparging gas through the membrane module. A simulation showed that the bioreactor could upgrade biogas at a rate of 25m(3)/mR(3)d, increasing the CH4 concentration from 60 to 95%v. This proof-of-concept study verified that gas sparging through a membrane module can efficiently transfer H2 from gas to liquid phase and that the conversion of H2 and CO2 to biomethane is feasible on a pilot scale at noteworthy load rates. PMID:25770473

  3. Performance and microbial community analysis of the anaerobic reactor with coke oven gas biomethanation and in situ biogas upgrading.

    PubMed

    Wang, Wen; Xie, Li; Luo, Gang; Zhou, Qi; Angelidaki, Irini

    2013-10-01

    A new method for simultaneous coke oven gas (COG) biomethanation and in situ biogas upgrading in anaerobic reactor was developed in this study. The simulated coke oven gas (SCOG) (92% H2 and 8% CO) was injected directly into the anaerobic reactor treating sewage sludge through hollow fiber membrane (HFM). With pH control at 8.0, the added H2 and CO were fully consumed and no negative effects on the anaerobic degradation of sewage sludge were observed. The maximum CH4 content in the biogas was 99%. The addition of SCOG resulted in enrichment and dominance of homoacetogenetic genus Treponema and hydrogenotrophic genus Methanoculleus in the liquid, which indicated that H2 were converted to methane by both direct (hydrogenotrophic methanogenesis) and indirect (homoacetogenesis+aceticlastic methanogenesis) pathways in the liquid. However, the aceticlasitic genus Methanosaeta was dominant for archaea in the biofilm on the HFM, which indicated indirect (homoacetogenesis+aceticlastic methanogenesis) H2 conversion pathway on the biofilm. PMID:23941705

  4. Analysis on Reduction of Greenhouse Gas Emissions by the Introduction of a Bio-methane Production Plant Using Dairy Cow Slurry as the Main Ingredient, and Management Balance of the Plant

    NASA Astrophysics Data System (ADS)

    Ohkubo, Takashi; Hideshima, Yoshiaki; Shudo, Yukoh; Ohmiya, Kazuhiko

    A study was conducted on a system to refine biogas generated from a biogas plant, which uses cow slurry as its main ingredient, and use the bio-methane as a regional energy supply source. Based on the data obtained by the demonstrative operation of the biogas plant and bio-methane production experiments, a bio-methane production plant that can process waste from 1,000 dairy cows was assumed, and optimization of plant operation was attempted using the linear programming method with maximum environmental friendliness (reduction of greenhouse gas emissions) and economic efficiency (management balance of the plant) as the target functions. The results revealed that plant operation methods varied according to the target of optimization. Environmental friendliness and economic efficiency were in a trade-off relationship with each other, but in the case where the greatest importance was placed on economic efficiency, greenhouse gas emissions were equivalent to that in the case where the greatest importance was placed on environmental friendliness itself. However, the values of economic efficiency were negative in both cases, indicating that it is difficult to make the plant management economically feasible under the current circumstances. To make the plant management balance positive, it is necessary to take measures, such as reduction of plant construction costs and exemption from interest costs. In addition, as a future direction for such regional bio-methane use, a micro grid system with a dispersed power source using bio-methane as raw fuel was presented.

  5. H2A Biomethane Model Documentation and a Case Study for Biogas From Dairy Farms

    SciTech Connect

    Saur, G.; Jalalzadeh, A.

    2010-12-01

    The new H2A Biomethane model was developed to estimate the levelized cost of biomethane by using the framework of the vetted original H2A models for hydrogen production and delivery. For biomethane production, biogas from sources such as dairy farms and landfills is upgraded by a cleanup process. The model also estimates the cost to compress and transport the product gas via the pipeline to export it to the natural gas grid or any other potential end-use site. Inputs include feed biogas composition and cost, required biomethane quality, cleanup equipment capital and operations and maintenance costs, process electricity usage and costs, and pipeline delivery specifications.

  6. Life cycle assessment of biomethane use in Argentina.

    PubMed

    Morero, Betzabet; Groppelli, Eduardo; Campanella, Enrique A

    2015-04-01

    Renewable substitutes for natural gas, such as biogas, require adequate treatment to remove impurities. This paper presents the life cycle and environmental impact of upgrading biogas using absorption-desorption process with three different solvents: water, diglycolamine and polyethylene glycol dimethyl ether. The results showed that water produces a minor impact in most of the considered categories, and an economic analysis showed that water is the most feasible solvent for obtaining the lowest payback period. This analysis includes three different sources for biogas production and two end uses for biomethane. The use of different wastes as sources results in different environmental impacts depending on the type of energy used in the anaerobic digestion. The same situation occurs when considering the use of biomethane as a domestic fuel or for power generation. Using energy from biogas to replace conventional energy sources in production and upgrading biogas significantly reduce the environmental impacts of processes. PMID:25700340

  7. The potential of bio-methane as bio-fuel/bio-energy for reducing greenhouse gas emissions: a qualitative assessment for Europe in a life cycle perspective.

    PubMed

    Tilche, Andrea; Galatola, Michele

    2008-01-01

    Anaerobic digestion is a well known process that (while still capable of showing new features) has experienced several waves of technological development. It was "born" as a wastewater treatment system, in the 1970s showed promise as an alternative energy source (in particular from animal waste), in the 1980s and later it became a standard for treating organic-matter-rich industrial wastewater, and more recently returned to the market for its energy recovery potential, making use of different biomasses, including energy crops. With the growing concern around global warming, this paper looks at the potential of anaerobic digestion in terms of reduction of greenhouse gas (GHG) emissions. The potential contribution of anaerobic digestion to GHG reduction has been computed for the 27 EU countries on the basis of their 2005 Kyoto declarations and using life cycle data. The theoretical potential contribution of anaerobic digestion to Kyoto and EU post-Kyoto targets has been calculated. Two different possible biogas applications have been considered: electricity production from manure waste, and upgraded methane production for light goods vehicles (from landfill biogas and municipal and industrial wastewater treatment sludges). The useful heat that can be produced as by-product from biogas conversion into electricity has not been taken into consideration, as its real exploitation depends on local conditions. Moreover the amount of biogas already produced via dedicated anaerobic digestion processes has also not been included in the calculations. Therefore the overall gains achievable would be even higher than those reported here. This exercise shows that biogas may considerably contribute to GHG emission reductions in particular if used as a biofuel. Results also show that its use as a biofuel may allow for true negative GHG emissions, showing a net advantage with respect to other biofuels. Considering also energy crops that will become available in the next few years as a

  8. Waste-to-biomethane Concept Application: A Case Study of Valmiera City in Latvia

    NASA Astrophysics Data System (ADS)

    Barisa, Aiga; Dzene, Ilze; Rosa, Marika; Dobraja, Kristine

    2015-12-01

    The current needs of sustainable urban development are rising. As the transport sector expands, emissions continue to rise. Due to their negative impact on human health and the environment, air quality requirements are becoming more and more stringent. At the same time, the amount of waste is increasing. Europe Union policies attempt to relieve the pressure that these two stressors place on urban systems as they themselves expand. Today different solutions are available to decrease greenhouse gas emissions, increase air quality and improve waste management systems. Among them, waste-to-biomethane for use in urban systems deserves more attention. The paper focuses on application of the concept of waste-to-biomethane and the case study of Valmiera is evaluated. The results show that the application of the waste-to-biomethane strategy can contribute to a complete substitution of diesel fuel in urban buses and gives savings of around 1,000 tCO2/year. The price of the biomethane was found to be the most sensitive input factor. It is suggested that it should not exceed 0.40 EUR/Nm3 for a fuel conversion project of a fleet of 10 vehicles. Such a price can be ensured, if dry fermentation technology is chosen for biogas production. However, from the sustainability perspective, wet fermentation is more preferable due to the introduction of a source-separated organic waste management system in the region and higher gas yields. Introduction of this alternative requires additional funds which is a question of policy-level decisions.

  9. Structural basis for Gas6–Axl signalling

    PubMed Central

    Sasaki, Takako; Knyazev, Pjotr G; Clout, Naomi J; Cheburkin, Yuri; Göhring, Walter; Ullrich, Axel; Timpl, Rupert; Hohenester, Erhard

    2006-01-01

    Receptor tyrosine kinases of the Axl family are activated by the vitamin K-dependent protein Gas6. Axl signalling plays important roles in cancer, spermatogenesis, immunity, and platelet function. The crystal structure at 3.3 Å resolution of a minimal human Gas6/Axl complex reveals an assembly of 2:2 stoichiometry, in which the two immunoglobulin-like domains of the Axl ectodomain are crosslinked by the first laminin G-like domain of Gas6, with no direct Axl/Axl or Gas6/Gas6 contacts. There are two distinct Gas6/Axl contacts of very different size, both featuring interactions between edge β-strands. Structure-based mutagenesis, protein binding assays and receptor activation experiments demonstrate that both the major and minor Gas6 binding sites are required for productive transmembrane signalling. Gas6-mediated Axl dimerisation is likely to occur in two steps, with a high-affinity 1:1 Gas6/Axl complex forming first. Only the minor Gas6 binding site is highly conserved in the other Axl family receptors, Sky/Tyro3 and Mer. Specificity at the major contact is suggested to result from the segregation of charged and apolar residues to opposite faces of the newly formed β-sheet. PMID:16362042

  10. A Critical Assessment of Microbiological Biogas to Biomethane Upgrading Systems.

    PubMed

    Rittmann, Simon K-M R

    2015-01-01

    Microbiological biogas upgrading could become a promising technology for production of methane (CH(4)). This is, storage of irregular generated electricity results in a need to store electricity generated at peak times for use at non-peak times, which could be achieved in an intermediate step by electrolysis of water to molecular hydrogen (H(2)). Microbiological biogas upgrading can be performed by contacting carbon dioxide (CO(2)), H(2) and hydrogenotrophic methanogenic Archaea either in situ in an anaerobic digester, or ex situ in a separate bioreactor. In situ microbiological biogas upgrading is indicated to require thorough bioprocess development, because only low volumetric CH(4) production rates and low CH(4) fermentation offgas content have been achieved. Higher volumetric production rates are shown for the ex situ microbiological biogas upgrading compared to in situ microbiological biogas upgrading. However, the ex situ microbiological biogas upgrading currently suffers from H(2) gas liquid mass transfer limitation, which results in low volumetric CH(4) productivity compared to pure H(2)/CO(2) conversion to CH(4). If waste gas utilization from biological and industrial sources can be shown without reduction in volumetric CH(4) productivity, as well as if the aim of a single stage conversion to a CH(4) fermentation offgas content exceeding 95 vol% can be demonstrated, ex situ microbiological biogas upgrading with pure or enrichment cultures of methanogens could become a promising future technology for almost CO(2)-neutral biomethane production. PMID:26337846

  11. Modelling a demand driven biogas system for production of electricity at peak demand and for production of biomethane at other times.

    PubMed

    O'Shea, R; Wall, D; Murphy, J D

    2016-09-01

    Four feedstocks were assessed for use in a demand driven biogas system. Biomethane potential (BMP) assays were conducted for grass silage, food waste, Laminaria digitata and dairy cow slurry. Semi-continuous trials were undertaken for all feedstocks, assessing biogas and biomethane production. Three kinetic models of the semi-continuous trials were compared. A first order model most accurately correlated with gas production in the pulse fed semi-continuous system. This model was developed for production of electricity on demand, and biomethane upgrading. The model examined a theoretical grass silage digester that would produce 435kWe in a continuous fed system. Adaptation to demand driven biogas required 187min to produce sufficient methane to run a 2MWe combined heat and power (CHP) unit for 60min. The upgrading system was dispatched 71min following CHP shutdown. Of the biogas produced 21% was used in the CHP and 79% was used in the upgrading system. PMID:27240240

  12. Thermo-Acidic Pretreatment of Beach Macroalgae from Rügen to Optimize Biomethane Production—Double Benefit with Simultaneous Bioenergy Production and Improvement of Local Beach and Waste Management

    PubMed Central

    Barbot, Yann Nicolas; Thomsen, Laurenz; Benz, Roland

    2015-01-01

    Eutrophication is a phenomenon which can rapidly generate masses of marine macroalgae, particularly in areas with high nutrient pollution. Washed ashore, this biomass impairs coastal tourism and negatively affects the coastal ecosystem. The present study evaluates the biochemical methane potential (BMP) of a macroalgae mix (Rügen-Mix, RM (RM = Rügen-Mix)) originating from Rügen, Germany. To improve biomethane recovery, thermo-acidic pretreatment was applied to the biomass prior to biomethanation to disintegrate the biomass macrostructure. Acid hydrolysis was successfully triggered with 0.2 M industry-grade HCl at 80 °C for a 2 h period, increasing biomethane recovery by +39%, with a maximum BMP of 121 mL·g−1 volatile solids (VS). To reduce the necessity for input material, HCl was replaced by the acidic waste product flue gas condensate (FGC). Improved performance was achieved by showing an increase in biomethane recovery of +24% and a maximum BMP of 108 mL·g−1 VS. Continuous anaerobic digestion trials of RM were conducted for three hydraulic retention times, showing the feasibility of monodigestion. The biomethane recovery was 60 mL and 65 mL·g−1 VS·d−1 for thermophilic and mesophilic operation, respectively. The quality of biomethanation performance aligned to the composition of the source material which exhibited a low carbon/nitrogen ratio and an increased concentration of sulfur compounds. PMID:26404327

  13. Thermo-Acidic Pretreatment of Beach Macroalgae from Rügen to Optimize Biomethane Production--Double Benefit with Simultaneous Bioenergy Production and Improvement of Local Beach and Waste Management.

    PubMed

    Barbot, Yann Nicolas; Thomsen, Laurenz; Benz, Roland

    2015-09-01

    Eutrophication is a phenomenon which can rapidly generate masses of marine macroalgae, particularly in areas with high nutrient pollution. Washed ashore, this biomass impairs coastal tourism and negatively affects the coastal ecosystem. The present study evaluates the biochemical methane potential (BMP) of a macroalgae mix (Rügen-Mix, RM (RM = Rügen-Mix)) originating from Rügen, Germany. To improve biomethane recovery, thermo-acidic pretreatment was applied to the biomass prior to biomethanation to disintegrate the biomass macrostructure. Acid hydrolysis was successfully triggered with 0.2 M industry-grade HCl at 80 °C for a 2 h period, increasing biomethane recovery by +39%, with a maximum BMP of 121 mL·g(-1) volatile solids (VS). To reduce the necessity for input material, HCl was replaced by the acidic waste product flue gas condensate (FGC). Improved performance was achieved by showing an increase in biomethane recovery of +24% and a maximum BMP of 108 mL·g(-1) VS. Continuous anaerobic digestion trials of RM were conducted for three hydraulic retention times, showing the feasibility of monodigestion. The biomethane recovery was 60 mL and 65 mL·g(-1) VS·d(-1) for thermophilic and mesophilic operation, respectively. The quality of biomethanation performance aligned to the composition of the source material which exhibited a low carbon/nitrogen ratio and an increased concentration of sulfur compounds. PMID:26404327

  14. Pilot plant for biomethanation of dairy-industry wastes

    SciTech Connect

    Ghosh, S.; Fukushi, K.; Liu, T.

    1994-12-31

    This project was undertaken to demonstrate the application of two-phase anaerobic digestion (TPAD) for simultaneous stabilization and biomethanation of high-COD cheese-waste-dairy-manure mixtures by a pilot-plant operation in Wellsville, Utah. The TPAD system exhibited a total COD (TCOD) reduction of up to 97% with feed COD concentration of 60,000 to 45,000 mg/l. The TCOD reduction decreased as the variability as well as the strength of the feed increased. A quick surge of the feed TCOD concentration to 125,000 mg/l effected a large drop in TCOD reduction, but the integrity of the methane digester, which produced 78 {approximately}87 mol% methane-content gas, was measured and TPAD system performance could be restored to normal levels by diluting the feed to obtain TCOD concentrations below 70,000 mg/l. The TPAD system exhibited a methane yield of 0.27 m{sup 3}/kg TCOD charged (0.36 m{sup 3}/kg TCOD removed).

  15. Site-specific economic and ecological analysis of enhanced production, upgrade and feed-in of biomethane from organic wastes.

    PubMed

    Lindorfer, J; Schwarz, M M

    2013-01-01

    The present study analyses the cost structure and ecological performance of biomethane production and feed-in from organic wastes and manure in a site-specific approach for Upper Austria. The theoretically available quantities of biowaste and manure can feed representative biogas plant capacities resulting in relatively high biomethane full costs in the natural gas grid of at least 9.0 €-cents/kWh, which shows strong economies of scale when feed-in flows of methane from 30 to 120 Nm(3)/h are considered. From the ecological point of view small plant capacities are to be preferred since the environmental effect, i.e. the global warming potential (up to -22% of CO(2eq)), is lower in comparison to higher capacities as a consequence of reduced transport in the evaluated scenarios. To enforce the combined energetic use of the biowaste fraction, co-operation between compost facility, gas grid and biogas plant operators is necessary to use existing infrastructure, logistics and knowledge to promote the production, upgrade and feed-in of biomethane from biowastes at attractive locations in Upper Austria and in the whole of Europe. PMID:23202576

  16. Impact of biological treatments of bio-waste for nutrients, energy and bio-methane recovery in a life cycle perspective.

    PubMed

    Di Maria, Francesco; Micale, Caterina; Contini, Stefano; Morettini, Emanuela

    2016-06-01

    Composting of the source-segregated organic fraction of municipal solid waste was compared in a life cycle perspective with conventional anaerobic digestion (AD), aimed at electricity substitution, and with AD aimed at biogas upgrading into bio-methane. Three different uses of the bio-methane were considered: injection in the natural gas grid for civil heating needs; use as fuel for high efficiency co-generation; use as fuel for vehicles. Scenarios with biogas upgrading showed quite similar impact values, generally higher than those of composting and conventional AD, for which there was a lower impact. A decisive contribution to the higher impact of the scenarios with bio-methane production was by the process for biogas upgrading. In any case the substitution of natural gas with bio-methane resulted in higher avoided impacts compared to electricity substitution by conventional AD. The uncertainty analysis confirmed the positive values for eutrophication, acidification and particulate matter. Large uncertainty was determined for global warming and photochemical ozone formation. PMID:27095293

  17. Biomethane as an Environment-Friendly Fuel for Municipal Transport

    NASA Astrophysics Data System (ADS)

    Papacz, Władysław J.

    2012-09-01

    An idea to replace the conventional engine fuel with biomethane has been described. The effects of such a swap have been analysed for municipal transport buses in Warsaw. The replacement has been shown to result in a significant reduction of toxic exhaust emissions and in economic savings. The analysis results have been presented in the form of tables and graphs.

  18. Safety basis For activities in double-shell tanks with flammable gas concerns

    SciTech Connect

    Schlosser, R.L.

    1996-02-05

    This is full revision to Revision 0 of this report. The purpose of this report is to provide a summary of analyses done to support activities performed for double shell tanks. These activities are encompassed by the flammable gas Unreviewed Safety Question (USQ). The basic controls required to perform these activities involve the identification, elimination and/or control of ignition sources and monitoring for flammable gases. Controls are implemented through the Interim Safety Basis (ISB), IOSRs, and OSDs. Since this report only provides a historical compendium of issues and activities, it is not to be used as a basis to perform USQ screenings and evaluations. Furthermore, these analyses and others in process will be used as the basis for developing the Flammable Gas Topical Report for the ISB Upgrade.

  19. Safety basis for selected activities in single-shell tanks with flammable gas concerns. Revision 1

    SciTech Connect

    Schlosser, R.L.

    1996-02-05

    This is full revision to Revision 0 of this report. The purpose of this report is to provide a summary of analyses done to support activities performed for single-shell tanks. These activities are encompassed by the flammable gas Unreviewed Safety Question (USQ). The basic controls required to perform these activities involve the identification, elimination and/or control of ignition sources and monitoring for flammable gases. Controls are implemented through the Interim Safety Basis (ISB), IOSRs, and OSDs. Since this report only provides a historical compendium of issues and activities, it is not to be used as a basis to perform USQ screenings and evaluations. Furthermore, these analyses and others in process will be used as the basis for developing the Flammable Gas Topical Report for the ISB Upgrade.

  20. Biohydrogen and biomethane production sustained by untreated matrices and alternative application of compost waste.

    PubMed

    Arizzi, Mariaconcetta; Morra, Simone; Pugliese, Massimo; Gullino, Maria Lodovica; Gilardi, Gianfranco; Valetti, Francesca

    2016-10-01

    Biohydrogen and biomethane production offers many advantages for environmental protection over the fossil fuels or the existing physical-chemical methods for hydrogen and methane synthesis. The aim of this study is focused on the exploitation of several samples from the composting process: (1) a mixture of waste vegetable materials ("Mix"); (2) an unmatured compost sample (ACV15); and (3) three types of green compost with different properties and soil improver quality (ACV1, ACV2 and ACV3). These samples were tested for biohydrogen and biomethane production, thus obtaining second generation biofuels and resulting in a novel possibility to manage renewable waste biomasses. The ability of these substrates as original feed during dark fermentation was assayed anaerobically in batch, in glass bottles, in order to determine the optimal operating conditions for hydrogen and/or methane production using "Mix" or ACV1, ACV2 or ACV3 green compost and a limited amount of water. Hydrogen could be produced with a fast kinetic in the range 0.02-2.45mLH2g(-1)VS, while methane was produced with a slower kinetic in the range 0.5-8mLCH4g(-1)VS. It was observed that the composition of each sample influenced significantly the gas production. It was also observed that the addition of different water amounts play a crucial role in the development of hydrogen or methane. This parameter can be used to push towards the alternative production of one or another gas. Hydrogen and methane production was detected spontaneously from these matrices, without additional sources of nutrients or any pre-treatment, suggesting that they can be used as an additional inoculum or feed into single or two-stage plants. This might allow the use of compost with low quality as soil improver for alternative and further applications. PMID:27422046

  1. Simulation of rarefied gas flows on the basis of the Boltzmann kinetic equation solved by applying a conservative projection method

    NASA Astrophysics Data System (ADS)

    Dodulad, O. I.; Kloss, Yu. Yu.; Potapov, A. P.; Tcheremissine, F. G.; Shuvalov, P. V.

    2016-06-01

    Flows of a simple rarefied gas and gas mixtures are computed on the basis of the Boltzmann kinetic equation, which is solved by applying various versions of the conservative projection method, namely, a two-point method for a simple gas and gas mixtures with a small difference between the molecular masses and a multipoint method in the case of a large mass difference. Examples of steady and unsteady flows are computed in a wide range of Mach and Knudsen numbers.

  2. Biomethane Production as an Alternative Bioenergy Source from Codigesters Treating Municipal Sludge and Organic Fraction of Municipal Solid Wastes

    PubMed Central

    Ersahin, M. Evren; Yangin Gomec, Cigdem; Dereli, R. Kaan; Arikan, Osman; Ozturk, Izzet

    2011-01-01

    Energy recovery potential of a mesophilic co-digester treating OFMSW and primary sludge at an integrated biomethanization plant was investigated based on feasibility study results. Since landfilling is still the main solid waste disposal method in Turkey, land scarcity will become one of the most important obstacles. Restrictions for biodegradable waste disposal to sanitary landfills in EU Landfill Directive and uncontrolled long-term contamination with gas emissions and leachate necessitate alternative management strategies due to rapid increase in MSW production. Moreover, since energy contribution from renewable resources will be required more in the future with increasing oil prices and dwindling supplies of conventional energy sources, the significance of biogas as a renewable fuel has been increased in the last decade. Results indicated that almost 93% of annual total cost can be recovered if 100% renewable energy subsidy is implemented. Besides, considering the potential revenue when replacing transport fuels, about 26 heavy good vehicles or 549 cars may be powered per year by the biogas produced from the proposed biomethanization plant (PE = 100,000; XPS = 61 g TS/PE·day; XSS-OFMSW = 50 g TS/PE·day). PMID:21274432

  3. Biomethane production system: Energetic analysis of various scenarios.

    PubMed

    Wu, Bin; Zhang, Xiangping; Bao, Di; Xu, Yajing; Zhang, Suojiang; Deng, Liyuan

    2016-04-01

    The energy consumption models of biomethane production system were established, which are more rigorous and universal than the empirical data reported by previous biomethane system energetic assessment work. The energy efficiencies of different scenarios considering factors such as two digestion modes, two heating modes of digester, with or without heat exchange between slurry and feedstock, and four crude biogas upgrading technologies were evaluated. Results showed the scenario employing thermophilic digestion and high pressure water scrubbing technology, with heat exchange between feedstock and slurry, and heat demand of digester supplied by the energy source outside the system has the highest energy efficiency (46.5%) and lowest energy consumption (13.46 MJth/Nm(3) CH4), while scenario employing mesophilic digestion and pressure swing adsorption technology, without heat exchange and heat demand of digester supplied by combusting the biogas produced inside the system has the lowest energy efficiency (15.8%) and highest energy consumption (34.90 MJth/Nm(3) CH4). PMID:26855289

  4. Characterization of anaerobic consortia coupled lignin depolymerization with biomethane generation.

    PubMed

    Wu, Yi-Rui; He, Jianzhong

    2013-07-01

    Two sediment-free microbial consortia (LI3 and LP3) were established to depolymerize lignin under anaerobic conditions. During depolymerizing high molecular weight lignin to low molecular weight molecules, the two cultures produced biomethane up to 151.7 and 113.0 mL g(-1) total lignin. Furthermore, LI3 and LP3 could also utilize the biomass - oil palm empty fruit bunch fiber (OPEFB) to produce 190.6 and 195.6 mL methaneg(-1) total lignin in OPEFB, and at the same time improve the bioavailability of lignocellulosic matters for further enzymatic hydrolysis. The microbial community analysis by denature gradient gel electrophoresis (DGGE) and the high-density 16S rDNA gene microarray (PhyloChip) exhibited that Methanomethylovorans sp. (LI3) and Methanoculleus sp. (LP3) were the main methanogens present, and phylum Firmicutes and Bacteroidetes were mainly involved in the lignin depolymerization. The established microbial consortia with both lignin depolymerization and biomethane production provide profound application on the environmental friendly pretreatment of lignocellulosic materials. PMID:23639408

  5. Leachate from market refuse and biomethanation study.

    PubMed

    Mukherjee, S N; Kumar, Sunil

    2007-12-01

    The market place is considered to be an important centre of daily life of campus community. In India, as in Europe and the USA, other forms of shopping have emerged significantly and now predominate, for instance department stores and supermarkets. Though, it is suffered from poor waste management, but the place could be a potential source for obtaining non-conventional energy. The present study examined the quality of market waste management of the Indian Institute of Technology Campus along with the feasibility of biogas production from leachate generated in the waste. Solid wastes from different storage locations of the market place were collected and analyzed. The characteristics of solid wastes were found to be degradable in nature. The wastes, composed of 85% of vegetable origin, were placed in a container and water was added to to generate leachate. The self-purification efficiency of leachate was also studied in the Indian environment and compared with research findings in the USA under an identical moisture application rate. Leachate characterization was investigated both under saturated and submerged conditions. The treatability of leachate was studied in a laboratory-scale up-flow anaerobic filter with hollow burnt clay rings as packing media. It was observed that 4,000-6,000 mg/l would be the optimum range of inlet chemical oxygen demand (COD) concentration for leachate treatment because of the inhibitory effect of ammonia, sulphide, volatile fatty acids and toxic metals in high concentrations at higher strengths of leachate. The gas production rate was found to be at a maximum at 38 degrees C and containing 70-75% methane. From experimental data, it was revealed that 83% COD was removed with input COD concentration of 5,475 mg/l at 2 days hydraulic retention time with biogas yield coefficients of 0.61. The present study also investigated the removal efficiency of chloride, ammonia, sulphide and nitrate. PMID:17505906

  6. Modular High Temperature Gas-Cooled Reactor Safety Basis and Approach

    SciTech Connect

    David Petti; Jim Kinsey; Dave Alberstein

    2014-01-01

    Various international efforts are underway to assess the safety of advanced nuclear reactor designs. For example, the International Atomic Energy Agency has recently held its first Consultancy Meeting on a new cooperative research program on high temperature gas-cooled reactor (HTGR) safety. Furthermore, the Generation IV International Forum Reactor Safety Working Group has recently developed a methodology, called the Integrated Safety Assessment Methodology, for use in Generation IV advanced reactor technology development, design, and design review. A risk and safety assessment white paper is under development with respect to the Very High Temperature Reactor to pilot the Integrated Safety Assessment Methodology and to demonstrate its validity and feasibility. To support such efforts, this information paper on the modular HTGR safety basis and approach has been prepared. The paper provides a summary level introduction to HTGR history, public safety objectives, inherent and passive safety features, radionuclide release barriers, functional safety approach, and risk-informed safety approach. The information in this paper is intended to further the understanding of the modular HTGR safety approach. The paper gives those involved in the assessment of advanced reactor designs an opportunity to assess an advanced design that has already received extensive review by regulatory authorities and to judge the utility of recently proposed new methods for advanced reactor safety assessment such as the Integrated Safety Assessment Methodology.

  7. Co-digestion of Whey with Glycerin in an AnSBBR for Biomethane Production.

    PubMed

    Lovato, G; Ratusznei, S M; Rodrigues, J A D; Zaiat, M

    2016-01-01

    This study aimed to evaluate the co-digestion of cheese whey and glycerin in an anaerobic sequencing batch biofilm reactor (AnSBBR) with recirculation of the liquid phase applied to biomethane production. The applied volumetric organic load (AVOL) in all conditions was 7.5 kgCOD m(-3) day(-1). The feeding time was equal to half of the cycle time. The best condition for co-digestion was the wastewater with 75 % of cheese whey and 25 % of glycerin (chemical oxygen demand (COD) basis); it achieved a productivity of 101.8 molCH4 m(-3) day(-1) and a yield of 13.3 molCH4 kgCOD(-1) with 89 % of COD removal. This represents an increase of productivity of almost 9 and 30 % when compared to the anaerobic digestion of cheese whey and glycerin alone, respectively. The co-digestion proposed is a promising solution for both pollutants with the advantage of high energy production. A first-order kinetic model was fitted efficiently to the process. PMID:26400495

  8. The physiological basis of pulmonary gas exchange: implications for clinical interpretation of arterial blood gases.

    PubMed

    Wagner, Peter D

    2015-01-01

    The field of pulmonary gas exchange is mature, with the basic principles developed more than 60 years ago. Arterial blood gas measurements (tensions and concentrations of O₂ and CO₂) constitute a mainstay of clinical care to assess the degree of pulmonary gas exchange abnormality. However, the factors that dictate arterial blood gas values are often multifactorial and complex, with six different causes of hypoxaemia (inspiratory hypoxia, hypoventilation, ventilation/perfusion inequality, diffusion limitation, shunting and reduced mixed venous oxygenation) contributing variably to the arterial O₂ and CO₂ tension in any given patient. Blood gas values are then usually further affected by the body's abilities to compensate for gas exchange disturbances by three tactics (greater O₂ extraction, increasing ventilation and increasing cardiac output). This article explains the basic principles of gas exchange in health, mechanisms of altered gas exchange in disease, how the body compensates for abnormal gas exchange, and based on these principles, the tools available to interpret blood gas data and, quantitatively, to best understand the physiological state of each patient. This understanding is important because therapeutic intervention to improve abnormal gas exchange in any given patient needs to be based on the particular physiological mechanisms affecting gas exchange in that patient. PMID:25323225

  9. Comparison of biomethane production and digestate characterization for selected agricultural substrates in Italy.

    PubMed

    Carchesio, M; Tatàno, F; Lancellotti, I; Taurino, R; Colombo, E; Barbieri, L

    2014-01-01

    Starting from (but not limited to) their importance in the Italian context, three agricultural substrates, two of fruit origin (grape seeds and plum stones) and one of herbaceous origin (woad), were comparatively tested for both biomethane production and digestate characterization. The anaerobic digestion tests showed that grape seeds had the highest net methane production of 253.0 NmL g volatile solids (VS)(-1), followed by plum stones, whose best resulting net methane production was 174.7 NmL gVS(-1), and finally by woad with a net methane production of 153.1 NmL gVS(-1). Interestingly, the best methane productions of the fruit substrates were obtained with different substrate to inoculum ratios (on a VS basis), 1:1 for grape seeds but 2:1 for plum stones. On the other hand, a three-month ageing of woad caused a limited reduction of methane production. The estimation of obtained degrees of conversion, carried out on a chemical oxygen demand (COD) basis for the specific tests achieving the respective best methane productions, gave values of 48%, 31%, and 33% for grape seeds, plum stones, and woad, respectively. The estimated degrees of conversion were evaluated along with the respective methane productions and substrate COD/VS ratios. The comparison of Fourier transform infrared (FT-IR) spectra and differential thermal analysis (DTA) profiles, carried out for selected digestates in pairs, revealed some distinctive differences in the relative intensities or presence and absence of particular peaks in the FT-IR spectra and in the relative intensities of the exothermic peaks or horizontal curve shifting of the DTA profiles. PMID:25145174

  10. Ecoengineering high rate anaerobic digestion systems: analysis of improved syntrophic biomethanation catalysts.

    PubMed

    Thiele, J H; Wu, W M; Jain, M K; Zeikus, J G

    1990-04-25

    High performance biomethanation granules with operational specific COD removal rates of 7 kg COD removed/kg SS/d were obtained by ecoengineering conventional, granular, UASB digester sludge using a designed protocol of starvation and selection on a defined volatile fatty acid (VFA) based mineral medium. Addition of low (0.15 mM) sulfate levels to this VFA medium increased the maximum shock-load COD removal rate of the ecoengineered biomethanation granules to 9 kg COD/kg SS/d with specific acetate, propionate, and butyrate removal rates of 111, 28, and 64 mol/g SS/d. Addition of moderate (26 mM) calcium levels inhibited growth and altered the structure of granules. The general cellular, growth, stability, and performance features of these ecoengineered granules are described and discussed in relation to their use as improved biomethanation starter cultures. PMID:18588244

  11. Screening of biomethane production potential from dominant microalgae.

    PubMed

    Fermoso, Fernando G; Beltran, Carolina; Jimenez, Antonia; Fernández, María José; Rincón, Bárbara; Borja, Rafael; Jeison, David

    2016-10-14

    The use of microalgae for biomethane production has been considerably increasing during the recent years. In this study, four dominant species belonging to the genera Scenedesmus, Chlorella, Dunaliella and Nostoc were selected. The influence of different genera with several morphological, structural and physicochemical characteristics on methane production was assessed in biochemical methane potential (BMP) tests. The ultimate methane yield values were 332 ± 24, 211 ± 2, 63 ± 17 and 28 ± 10 mL CH4/g VSadded for Scenedesmus obliquus, Chlorella sorokiniana, Dunaliella salina and Nostoc sp., respectively. The highest methane production was achieved by microalga species that had no complex cell wall or wall basically composed by proteins and simple sugars such as in S. obliquus, whereas lower methane yields were found for D. salina and Nostoc sp., due to the salinity effects and cell wall composition in terms of complex polysaccharide and glycolipid layers, respectively. Kinetic constant values obtained in the BMP tests ranged between 1.00 ± 0.08 and 0.097 ± 0.005 days(-1) for D. salina and S. obliquus, respectively. PMID:27409043

  12. Structural Basis for the Inhibition of Gas Hydrates by α-Helical Antifreeze Proteins.

    PubMed

    Sun, Tianjun; Davies, Peter L; Walker, Virginia K

    2015-10-20

    Kinetic hydrate inhibitors (KHIs) are used commercially to inhibit gas hydrate formation and growth in pipelines. However, improvement of these polymers has been constrained by the lack of verified molecular models. Since antifreeze proteins (AFPs) act as KHIs, we have used their solved x-ray crystallographic structures in molecular modeling to explore gas hydrate inhibition. The internal clathrate water network of the fish AFP Maxi, which extends to the protein's outer surface, is remarkably similar to the {100} planes of structure type II (sII) gas hydrate. The crystal structure of this water web has facilitated the construction of in silico models for Maxi and type I AFP binding to sII hydrates. Here, we have substantiated our models with experimental evidence of Maxi binding to the tetrahydrofuran sII model hydrate. Both in silico and experimental evidence support the absorbance-inhibition mechanism proposed for KHI binding to gas hydrates. Based on the Maxi crystal structure we suggest that the inhibitor adsorbs to the gas hydrate lattice through the same anchored clathrate water mechanism used to bind ice. These results will facilitate the rational design of a next generation of effective green KHIs for the petroleum industry to ensure safe and efficient hydrocarbon flow. PMID:26488661

  13. Effect of lipase addition on hydrolysis and biomethane production of Chinese food waste.

    PubMed

    Meng, Ying; Li, Sang; Yuan, Hairong; Zou, Dexun; Liu, Yanping; Zhu, Baoning; Li, Xiujin

    2015-03-01

    The lipase obtained from Aspergillums niger was applied to promote the hydrolysis of food waste for achieving high biomethane production. Two strategies of lipase additions were investigated. One (Group A) was to pre-treat food waste to pre-decompose lipid to fatty acids before anaerobic digestion, and another one (Group B) was to add lipase to anaerobic digester directly to degrade lipid inside digester. The lipase was used at the concentrations of 0.1%, 0.5%, and 1.0% (w/v). The results showed that Group A achieved higher biomethane production, TS and VS reductions than those of Group B. At 0.5% lipase concentration, Group A obtained experimental biomethane yield of 500.1 mL/g VS(added), 4.97-26.50% higher than that of Group B. The maximum Bd of 73.8% was also achieved in Group A. Therefore, lipase pre-treatment strategy is recommended. This might provide one of alternatives for efficient biomethane production from food waste and mitigating environmental impact associated. PMID:25575204

  14. Technical Basis for Gas-Phase Vadose Zone Remediation Technologies at Hanford: A Review - 12186

    SciTech Connect

    Truex, M.J.; Oostrom, M.; Szecsody, J.E.; Strickland, C.E.; Chronister, G.B.; Benecke, M.W.

    2012-07-01

    In situ vadose zone remediation approaches are being evaluated as potential options to mitigate the transport of inorganic and radionuclide contaminants from the vadose zone to the groundwater. Some of the candidate approaches are based on changing the contaminant or subsurface conditions in a way that slows downward migration of the contaminants through the vadose zone using amendments delivered in the gas-phase. Two promising approaches that have undergone testing at Hanford include soil desiccation to address technetium-99 contamination and ammonia-induced sequestration of uranium. For soil desiccation, a dry gas is injected to desiccate a targeted portion of the subsurface and thereby decrease contaminant movement by removing moisture and decreasing the hydraulic conductivity of the desiccated zone. Ammonia-induced sequestration of uranium relies on changing the pore water chemistry, primarily through pH changes, to induce dissolution and precipitation processes that decrease the amount of mobile uranium in the vadose zone. (authors)

  15. Microalgae Production from Power Plant Flue Gas: Environmental Implications on a Life Cycle Basis

    SciTech Connect

    Kadam, K. L.

    2001-06-22

    Power-plant flue gas can serve as a source of CO{sub 2} for microalgae cultivation, and the algae can be cofired with coal. This life cycle assessment (LCA) compared the environmental impacts of electricity production via coal firing versus coal/algae cofiring. The LCA results demonstrated lower net values for the algae cofiring scenario for the following using the direct injection process (in which the flue gas is directly transported to the algae ponds): SOx, NOx, particulates, carbon dioxide, methane, and fossil energy consumption. Carbon monoxide, hydrocarbons emissions were statistically unchanged. Lower values for the algae cofiring scenario, when compared to the burning scenario, were observed for greenhouse potential and air acidification potential. However, impact assessment for depletion of natural resources and eutrophication potential showed much higher values. This LCA gives us an overall picture of impacts across different environmental boundaries, and hence, can help in the decision-making process for implementation of the algae scenario.

  16. Development of self-contained mobile technological CO2 GDL on the basis of gas-turbine engine

    NASA Astrophysics Data System (ADS)

    Ikonnikov, Valerii K.; Maliavine, V. P.; Plotnikov, V. A.; Feofilaktov, V. A.

    1996-03-01

    Cw carbon-dioxide lasers with the output power of 15 kW have been used in such modern technological processes as welding, cutting and surface hardening. However there arise the problems which require the increase of power up to 50 kW. As an example, to disassemble some nuclear reactors it is necessary to cut plates made of special types of stainless steel up to 330 mm thick. The work of Gorny et al. gives a simple formula representing the thickness of the cut metal h versus the absorbed laser beam power W, its diameter d, cutting rate v, gas flow rate through the cut area G and thermophysical characteristics of metal. We show substitution of well-known constants for stainless steel into the formula. Plots of this dependence are given for cutting rate of 0.1 and 0.3 cm/s with different gas flow rates. It follows from the plots that, first, in order to increase cut depth, a simultaneous increase of power and gas flow rate G are required and secondly, with regard for the losses, power should equal 30 divided by 100 kW. The experience of the developments of high power cw CO and carbon dioxide lasers shows that the least mass and overall dimensions as well as the best operation characteristics with the power level of 30 kW and more refer to gas-dynamic lasers (GDL) due to the following advantages: (1) direct transformation of the portion of thermal energy into the coherent IR radiation; (2) absence of high-power electric sources; (3) absence of additional ejectors; (4) relative easiness in maintenance; and (5) application of compact aircraft units and devices with completed service life. The purpose of this paper is to consider the possibility of the creation of mobile self-contained technological gas-dynamic carbon- dioxide laser (SCT GDL) on the basis of gas-turbine engine (GTE).

  17. Acoustic diagnosis of gas insulated substations; A theoretical and experimental basis

    SciTech Connect

    Lundgaard, L.E.; Runde, M. ); Skyberg, B. )

    1990-10-01

    Loose particles and discharges inside the ducts of a gas insulated substation (GIS) are considered hazardous to the insulation system. These irregularities or flaws can be detected by using acoustic sensors placed on the enclosure. An elementary review of sound propagation in the GIS, together with corresponding experimental results are presented. By using ultrasonic acoustic emission sensors an excellent sensitivity to discharges and moving particles is obtained. The method offers possibilities for a quantification of the flaws, and thereby for a risk analysis. However, the degree of certainty of such an analysis is still low, especially for particles.

  18. The Potential Field of Carbon Bodies as a Basis for Sorption Properties of Barrier Gas Systems

    NASA Astrophysics Data System (ADS)

    Bubenchikov, A. M.; Bubenchikov, M. A.; Potekaev, A. I.; Libin, É. E.; Khudobina, Yu. P.

    2015-11-01

    A modification of the Lennard-Jones potential allowed us, via integration over the volume of the bodies of different shapes, to determine the integral action (potential energy barrier) generated by the distributed force centers. The body generating the potential barrier was a carbon plate and the test particles overcoming this barrier were atoms or molecules of a number of gases (hydrogen, helium and methane). When considering the transit of particles (gas atoms or molecules) over this barrier, use was made of the energy barrier wave theory and the potential of a continuous body was used as a barrier. In so doing, the Schrödinger equation was integrated numerically for the molecular density. This integration yielded the expected wave pattern of the process of transit and reflection of the molecules, so a phase averaging procedure had to be applied. By varying the parameters of the layer containing force centers - field sources, the dimensions and density of the carbon plate possessing high selectivity towards separation of gas mixture containing helium, hydrogen and methane were determined. The data obtained provide an interpretation of the sorption properties of barrier carbon systems capable of filtering or separating gases.

  19. The physical basis for absorption of light. [effects on wave functions of gas molecules and atoms

    NASA Technical Reports Server (NTRS)

    Pickett, H. M.

    1979-01-01

    The effects of light absorption on the wave functions of gas-phase molecules and atoms are investigated by high resolution spectral measurements of radiation emerging from a sample. A Stark-modulated sample of methyl fluoride was irradiated at the 102 GHz rotational transition and the emergent radiation was resolved by means of a spectrum analyzer. For signal oscillator frequencies below or above the molecular resonance by one modulation frequency, the amplitudes of the upper and lower modulation sidebands are found to be of nonuniform intensity, which is inconsistent with amplitude modulation. Emission due to polarization is, however, calculated to be consistent with the results observed, indicating that light absorption should be considered as a subtractive stimulated emission.

  20. Technical basis for extending storage of the UK's advanced gas-cooled reactor fuel

    SciTech Connect

    Hambley, D.I.

    2013-07-01

    The UK Nuclear Decommissioning Agency has recently declared a date for cessation of reprocessing of oxide fuel from the UK's Advanced Gas-cooled Reactors (AGRs). This will fundamentally change the management of AGR fuel: from short term storage followed by reprocessing to long term fuel storage followed, in all likelihood, by geological disposal. In terms of infrastructure, the UK has an existing, modern wet storage asset that can be adapted for centralised long term storage of dismantled AGR fuel under the required pond water chemistry. No AGR dry stores exist, although small quantities of fuel have been stored dry as part of experimental programmes in the past. These experimental programmes have shown concerns about corrosion rates.

  1. Standardized elemental basis for gas-turbine engine heat exchangers is the key factor for their cost reduction

    NASA Astrophysics Data System (ADS)

    Soudarev, A. V.; Soudarev, B. V.; Kondratiev, V. V.; Lazarev, M. V.

    2001-07-01

    The competitiveness of the small gas turbine units (GTUs) (Ne<300 kW) in the world power market is dependent on both the maintenance expenses and the capital costs of production. Reduction in the maintenance expenditures could be achieved by increasing the plant efficiency. This task could be solved by some methods: increasing the cycle inlet temperature TIT, getting the cycle more complex (use of heat regeneration and compressed air intermediate cooling), cutting the power consumption on heat-stressed parts cooling. Putting the above into effect is linked with introduction of novel structural materials, a sharp increase in the mass-size values and the plant manufacture expenditures, in particular, at provision of its self-regulation. In connection with the above, the development of the combined metal-ceramic airheaters and standardization of the elemental basis of the metal gas-gas heat exchangers will promote reduction in the expenditures of the maintenance and the manufacture of the small-size independent power GTEs.

  2. An ecological perspective of the energy basis of sustainable Bolivian natural resources: Forests and natural gas

    NASA Astrophysics Data System (ADS)

    Izursa, Jose-Luis

    National Industrialization Scenario. Using two different levels of increment for each scenario, the outcomes of six variables were analyzed: soil, wood, natural gas, assets, money and debt. It was found that if the country doubles its use of natural resources to generate finished products, this will build more assets for Bolivia, and represent more income for the country and a better rate of emergy per person.

  3. Life cycle assessment of biohydrogen and biomethane production and utilisation as a vehicle fuel.

    PubMed

    Patterson, Tim; Esteves, Sandra; Dinsdale, Richard; Guwy, Alan; Maddy, Jon

    2013-03-01

    Environmental burdens for the production and utilisation of biomethane vehicle fuel or a biohydrogen/biomethane blend produced from food waste or wheat feed, based on data from two different laboratory experiments, have been compared. For food waste treated by batch processes the two stage system gave high hydrogen yields (84.2l H2kg(-1) VS added) but a lower overall energy output than the single stage system. Reduction in environmental burdens compared with diesel was achieved, supported by the diversion of waste from landfill. For wheat feed, the semi continuously fed two stage process gave low hydrogen yields (7.5l H2kg(-1) VS added) but higher overall energy output. The process delivers reduction in fossil fuel burdens, and improvements in process efficiencies will lead to reduction in CO2 burdens compared with diesel. The study highlights the importance of understanding and optimising biofuel production parameters according to the feedstock utilised. PMID:23353037

  4. Improvement of gaseous energy recovery from sugarcane bagasse by dark fermentation followed by biomethanation process.

    PubMed

    Kumari, Sinu; Das, Debabrata

    2015-10-01

    The aim of the present study was to enhance the gaseous energy recovery from sugarcane bagasse. The two stage (biohydrogen and biomethanation) batch process was considered under mesophilic condition. Alkali pretreatment (ALP) was used to remove lignin from sugarcane bagasse. This enhanced the enzymatic digestibility of bagasse to a great extent. The maximum lignin removal of 60% w/w was achieved at 0.25 N NaOH concentration (50°C, 30 min). The enzymatic hydrolysis efficiency was increased to about 2.6-folds with alkali pretreated sugarcane bagasse as compared to untreated one. The maximum hydrogen and methane yields from the treated sugarcane bagasse by biohydrogen and biomethanation processes were 93.4 mL/g-VS and 221.8 mL/g-VS respectively. This process resulted in significant increase in energy conversion efficiency (44.8%) as compared to single stage hydrogen production process (5.4%). PMID:26210150

  5. GHG emission factors for bioelectricity, biomethane, and bioethanol quantified for 24 biomass substrates with consequential life-cycle assessment.

    PubMed

    Tonini, Davide; Hamelin, Lorie; Alvarado-Morales, Merlin; Astrup, Thomas Fruergaard

    2016-05-01

    Greenhouse gas (GHG) emission savings from biofuels dramatically depend upon the source of energy displaced and the effects induced outside the energy sector, for instance land-use changes (LUC). Using consequential life-cycle assessment and including LUC effects, this study provides GHG emission factors (EFs) for bioelectricity, biomethane, and bioethanol produced from twenty-four biomasses (from dedicated crops to residues of different origin) under a fossil and a non-fossil energy system. Accounting for numerous variations in the pathways, a total of 554 GHG EFs were quantified. The results showed that, important GHG savings were obtained with residues and seaweed, both under fossil and non-fossil energy systems. For high-yield perennial crops (e.g. willow and Miscanthus), GHG savings were achieved only under fossil energy systems. Biofuels from annual crops and residues that are today used in the feed sector should be discouraged, as LUC GHG emissions exceeded any GHG savings from displacing conventional energy sources. PMID:26938807

  6. Comparison of different pretreatments for the production of bioethanol and biomethane from corn stover and switchgrass.

    PubMed

    Papa, G; Rodriguez, S; George, A; Schievano, A; Orzi, V; Sale, K L; Singh, S; Adani, F; Simmons, B A

    2015-05-01

    In this study the efficiency of mild ionic liquid (IL) pretreatment and pressurized hot water (PHW) is evaluated and compared in terms of bioethanol and biomethane yields, with corn stover (CS) and switchgrass (SG) as model bioenergy crops. Both feedstocks pretreated with the IL 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] at 100°C for 3h exhibited lower glucose yield that those treated with harsher pretreatment conditions previously used. Compared to PHW, IL pretreatment demonstrated higher bioethanol yields; moreover IL pretreatment enhanced biomethane production. Taking into consideration both bioethanol and biomethane productions, results indicated that when using IL pretreatment, the total energy produced per kg of total solids was higher compared to untreated biomasses. Specifically energy produced from CS and SG was +18.6% and +34.5% respectively, as compared to those obtained by hot water treatment, i.e. +2.3% and +23.4% for CS and SG, respectively. PMID:25725408

  7. Using feature objects aided strategy to evaluate the biomethane production of food waste and corn stalk anaerobic co-digestion.

    PubMed

    Zhou, Qi; Yuan, Hairong; Liu, Yanping; Zou, Dexun; Zhu, Baoning; Chufo, Wachemo A; Jaffar, Muhammad; Li, Xiujin

    2015-03-01

    Feature objects aided strategy was used to predict and evaluate the biomethane production of food waste and corn stalk anaerobic co-digestion. The kinetics of co-digestion and mono-digestion of food waste and/or corn stalk was also analyzed. The results indicated that the compositions of food waste and corn stalk were significantly different. The anaerobic digestion of three feature objects at different mixing ratios showed the different biomethane yields and kinetic constants. Food waste and corn stalk co-digestion enhanced the digestion rate and achieved 22.48% and 41.55% higher biomethane production than those of food waste and corn stalk mono-digestion, respectively. PMID:25575585

  8. The biostimulation of anaerobic digestion with (semi)conductive ferric oxides: their potential for enhanced biomethanation.

    PubMed

    Baek, Gahyun; Kim, Jaai; Cho, Kyungjin; Bae, Hyokwan; Lee, Changsoo

    2015-12-01

    The effect of biostimulation with ferric oxides, semiconductive ferric oxyhydroxide, and conductive magnetite on the anaerobic digestion of dairy wastewater was examined in a batch mode. The reactors supplemented with ferric oxyhydroxide (R2) and magnetite (R3) showed significantly enhanced biomethanation performance compared with the control (R1). The removal of chemical oxygen demand (COD) after 30 days was 31.9, 59.3, and 82.5% in R1, R2, and R3, respectively. The consumed COD was almost fully recovered as biogas in R2 and R3, while only 79% was recovered in R1. The total energy production as biogas was accordingly 32.2, 71.0, and 97.7 kJ in R1, R2, and R3, respectively. The reactors also differed in the acid formation profile with more propionate and butyrate found in R1 and more acetate found in R3. The enhanced biomethanation seems to be associated with variations in the bacterial community structure supposedly induced by the ferric oxides added. In contrast, no evident variation was observed in the archaeal community structure among the reactors. The potential electric syntrophy formed between Methanosaeta concilii-like methanogens and electroactive iron-reducing bacteria, particularly Trichococcus, was likely responsible for the enhanced performance. The stimulated growth of fermentative iron reducers may also have contributed by altering the metabolic characteristics of the bacterial communities to produce more favorable acidogenic products for methanogenesis. The overall results suggest the potential of biostimulation with (semi)conductive ferric oxides to enhance the rate and efficiency of the biomethanation of organic wastes. This seems to be potentially attractive, as increasing attention is being paid to the energy self-sufficiency of waste/wastewater treatment processes today. PMID:26272096

  9. Biomethane production in an AnSBBR treating wastewater from biohydrogen process.

    PubMed

    Lullio, T G; Souza, L P; Ratusznei, S M; Rodrigues, J A D; Zaiat, M

    2014-11-01

    An anaerobic sequencing batch reactor containing immobilized biomass (AnSBBR) was used to produce biomethane by treating the effluent from another AnSBBR used to produce biohydrogen from glucose- (AR-EPHG) and sucrose-based (AR-EPHS) wastewater. In addition, biomethane was also produced from sucrose-based synthetic wastewater (AR-S) in a single AnSBBR to compare the performance of biomethane production in two steps (acidogenic and methanogenic) in relation to a one-step operation. The system was operated at 30 °C and at a fixed stirring rate of 300 rpm. For AR-EPHS treatment, concentrations were 1,000, 2,000, 3,000, and 4,000 mg chemical oxygen demand (COD) L(-1) and cycle lengths were 6 and 8 h. The applied volumetric organic loads were 2.15, 4.74, 5.44, and 8.22 g COD L(-1) day(-1). For AR-EPHG treatment, concentration of 4,000 mg COD L(-1) and 4-h cycle length (7.21 g COD L(-1) day(-1)) were used. For AR-S treatment, concentration was 4,000 mg COD L(-1) day(-1) and cycle lengths were 8 (7.04 g COD L(-1) day(-1)) and 12 h (4.76 g COD L(-1) day(-1)). The condition of 8.22 g COD L(-1) day(-1) (AR-EPHS) showed the best performance with respect to the following parameters: applied volumetric organic load of 7.56 g COD L(-1) day(-1), yield between produced methane and removed organic material of 0.016 mol CH4 g COD(-1), CH4 content in the produced biogas of 85 %, and molar methane productivity of 127.9 mol CH4 m(-3) day(-1). In addition, a kinetic study of the process confirmed the trend that, depending on the biodegradability characteristics of the wastewaters used, the two-step treatment (acidogenic for biohydrogen production and methanogenic for biomethane production) has potential advantages over the single-step process. PMID:25149460

  10. Effect of enzymatic pretreatment of various lignocellulosic substrates on production of phenolic compounds and biomethane potential.

    PubMed

    Schroyen, Michel; Vervaeren, Han; Vandepitte, Hanne; Van Hulle, Stijn W H; Raes, Katleen

    2015-09-01

    Pretreatment of lignocellulosic biomass is necessary to enhance the hydrolysis, which is the rate-limiting step in biogas production. Laccase and versatile peroxidase are enzymes known to degrade lignin. Therefore, the impact of enzymatic pretreatment was studied on a variety of biomass. A significant higher release in total phenolic compounds (TPC) was observed, never reaching the inhibiting values for anaerobic digestion. The initial concentration of TPC was higher in the substrates containing more lignin, miscanthus and willow. The anaerobic digestion of these two substrates resulted in a significant lower biomethane production (68.8-141.7 Nl/kg VS). Other substrates, corn stover, flax, wheat straw and hemp reached higher biomethane potential values (BMP), between 241 and 288 Nl/kg VS. Ensilaged maize reached 449 Nl/kg VS, due to the ensilation process, which can be seen as a biological and acid pretreatment. A significant relation (R(2) = 0.89) was found between lignin content and BMP. PMID:26094196

  11. Biomethane production and physicochemical characterization of anaerobically digested teff (Eragrostis tef) straw pretreated by sodium hydroxide.

    PubMed

    Chufo, Akiber; Yuan, Hairong; Zou, Dexun; Pang, Yunzhi; Li, Xiujin

    2015-04-01

    The biogas production potential and biomethane content of teff straw through pretreatment by NaOH was investigated. Different NaOH concentrations (1%, 2%, 4% and 6%) were used for each four solid loadings (50, 65, 80 and 95 g/L). The effects of NaOH as pretreatment factor on the biodegradability of teff straw, changes in main compositions and enhancement of anaerobic digestion were analyzed. The result showed that, using 4% NaOH for pretreatment in 80 g/L solid loading produced 40.0% higher total biogas production and 48.1% higher biomethane content than the untreated sample of teff straw. Investigation of changes in chemical compositions and physical microstructure indicated that there was 4.3-22.1% total lignocellulosic compositions removal after three days pretreatment with NaOH. The results further revealed that NaOH pretreatment changed the structural compositions and lignin network, and improved biogas production from teff straw. PMID:25656865

  12. Electroporation of Chlorella vulgaris to enhance biomethane production.

    PubMed

    Garoma, Temesgen; Shackelford, Trevor

    2014-10-01

    This research investigated the feasibility of using electroporation (EP) as a pretreatment method for algal biomass used as feedstock for anaerobic digestion. The results showed that pretreating algal biomass with EP significantly improved the soluble COD (SCOD), increasing it to more than 830% at 28 kWh/m(3) treatment intensity (TI). Besides TI, culture conditions also affected the performance of the EP process. On the basis of SCOD, a sample pH of 7.0 and cell concentration of 13.2g/L were found to be optimal for the EP process. Despite a direct relationship between TI and ionic strength (IS), SCOD decreased with increasing IS. At 35 kWh/m(3) TI, bio-CH4 production increased by as high as 110%. It was also observed that lower TI levels resulted in high rates of gain per energy input compared to higher degrees of treatment. PMID:25066903

  13. Development of biological coal gasification (MicGAS process). Final report, May 1, 1990--May 31, 1995

    SciTech Connect

    1998-12-31

    ARCTECH has developed a novel process (MicGAS) for direct, anaerobic biomethanation of coals. Biomethanation potential of coals of different ranks (Anthracite, bitumious, sub-bitumious, and lignites of different types), by various microbial consortia, was investigated. Studies on biogasification of Texas Lignite (TxL) were conducted with a proprietary microbial consortium, Mic-1, isolated from hind guts of soil eating termites (Zootermopsis and Nasutitermes sp.) and further improved at ARCTECH. Various microbial populations of the Mic-1 consortium carry out the multi-step MicGAS Process. First, the primary coal degraders, or hydrolytic microbes, degrade the coal to high molecular weight (MW) compounds. Then acedogens ferment the high MW compounds to low MW volatile fatty acids. The volatile fatty acids are converted to acetate by acetogens, and the methanogens complete the biomethanation by converting acetate and CO{sub 2} to methane.

  14. Optimization of gas condensate Field A development on the basis of "reservoir - gathering facilities system" integrated model

    NASA Astrophysics Data System (ADS)

    Demidova, E. A.; Maksyutina, O. V.

    2015-02-01

    It is known that many gas condensate fields are challenged with liquid loading and condensate banking problems. Therefore, gas production is declining with time. In this paper hydraulic fracturing treatment was considered as a method to improve the productivity of wells and consequently to exclude the factors that lead to production decline. This paper presents the analysis of gas condensate Field A development optimization with the purpose of maintaining constant gas production at the 2013 level for 8 years taking into account mentioned factors . To optimize the development of the filed, an integrated model was created. The integrated model of the field implies constructing the uniform model of the field consisting of the coupling models of the reservoir, wells and surface facilities. This model allowed optimizing each of the elements of the model separately and also taking into account the mutual influence of these elements. Using the integrated model, five development scenarios were analyzed and an optimal scenario was chosen. The NPV of this scenario equals 7,277 mln RUR, cumulative gas production - 12,160.6 mln m3, cumulative condensate production - 1.8 mln tons.

  15. Solid-state voltammetry and polymer electrolyte plasticization as a basis for an electrochemical gas chromatographic detector

    SciTech Connect

    Parcher, J.F.; Barbour, C.J.; Murray, R.W. )

    1989-03-15

    A new type of electrochemical gas chromatographic (ECGC) detector is described. The detector consists of a film of polymer electrolyte, PEO{sub 16}/LiCF{sub 3}SO{sub 3}, coating a microelectrode-based electrochemical cell and in contact with the effluent stream of a gas chromatograph. The PEO{sub 16}/LiCF{sub 3}SO{sub 3} polymer acts as an ionically conducting but physically rigid medium. Currents passed at the microelectrode/polymer interface depend on reactions of electroactive solutes dissolved in and diffusing through the polymer phase. These currents respond to the presence of sample components in the gas phase through their sorption into, and plasticization of, the PEO polymer phase. The polymer plasticization results in larger diffusion coefficients for the electroactive solutes and, consequently, larger microelectrode currents. Several forms of electrochemical potential control are examined as are the effects of chosen electroactive probe, probe concentration, polymer film thickness, and gaseous sample concentration and sorption. Faster detector responses are obtained with thin PEO{sub 16}/LiCF{sub 3}SO{sub 3} films and faster diffusing electroactive probes. The detector responds linearly to small quantities of sample but exponentially to large sample concentrations. The detector is unusual in that it is most sensitive to later-eluting components of a sample mixture; this effect results from the connection between the degree of sample component sorption or partition into the polymer electrolyte and the resulting degree of polymer plasticization and transport rate enhancement.

  16. Application of two-phase flow modeling as a basis for scheduling corrosion maintenance activities in wet sour gas pipelines

    SciTech Connect

    Richardson, D.; Bich, N.N.

    1997-08-01

    Pipeline failures attributed to internal corrosion in the oil and gas producing industry have not been decreasing despite the many corrosion mitigation, monitoring and inspection programs implemented. This paper describes how preliminary investigations for evaluating the susceptibility of internal corrosion for wet sour gas pipelines have been based on integrating the latest knowledge in fluid flow and sour gas corrosion mechanisms. It is anticipated future efforts to correlate the onset of slug flow regime with historical corrosion and inspection data may lead to development of an improved criteria for predicting the onset of corrosive water traps and for triggering appropriate maintenance activities. This paper provides details of two corrosion failure Case Studies where application of flow modeling has improved the understanding of the operating hazards that contributed to the formation of a corrosive environment leading to high-rate initiation and growth of localized pitting corrosion. Preliminary analysis indicates slug flow pattern, and long water residence time of water within stagnant traps increases the likelihood of pitting corrosion.

  17. An analysis of tank and pump pit flammable gas data in support of saltwater pumping safety basis simplification

    SciTech Connect

    MCCAIN, D.J.

    2000-07-26

    Hanford Site high-level waste tanks are interim stabilized by pumping supernatant and interstitial waste liquids to double-shell tanks (DSTs) through a saltwell pump (SWP). The motor to this SWP is located atop the tank, inside a pump pit. A pumping line extends down from the pump motor into the well area, located in the salt/sludge solids in the tank below. Pumping of these wastes is complicated by the fact that some of the wastes generate and retain potentially hazardous amounts of hydrogen, nitrous oxide, and ammonia. Monitoring of flammable gas concentrations during saltwell pumping activities has shown that one effect of pumping is acceleration in the release of accumulated hydrogen. A second effect is that of a temporarily increased hydrogen concentration in both the dome space and pump pit. There is a safety concern that the hydrogen concentration during saltwell pumping activities might approach the lower flammability limit (LFL) in either the tank dome space or the pump pit. The current Final Safety Analysis Report (FSAR) (CHG 2000) for saltwell pumping requires continuous flammable gas monitoring in both the pump pit and the tank vapor space during saltwell pumping. The FSAR also requires that portable exhauster fans be available by most of the passively ventilated tanks to be saltwell pumped in the event that additional air flow is required to dilute the headspace concentration of flammable gases to acceptable levels. The first objective of this analysis is to review the need for an auxiliary exhauster. Since the purpose of the exhauster is to diffuse unacceptably high flammable gas concentrations, discovery of an alternate method of accomplishing the same task may provide cost savings. The method reviewed is that of temporarily stopping the saltwell pumps. This analysis also examines the typical hydrogen concentration peaks and the rates of increase in hydrogen levels already witnessed in tanks during saltwell pumping activities. The historical data

  18. Microbial Ecophysiology of Whey Biomethanation: Comparison of Carbon Transformation Parameters, Species Composition, and Starter Culture Performance in Continuous Culture

    PubMed Central

    Chartrain, M.; Bhatnagar, L.; Zeikus, J. G.

    1987-01-01

    Changes in lactose concentration and feed rate altered bacterial growth and population levels in a whey-processing chemostat. The bacterial population and methane production levels increased in relation to increased lactose concentrations comparable to those in raw whey (6%) and converted over 96% of the substrate to methane, carbon dioxide, and cells. Sequential increases in the chemostat dilution rate demonstrated excellent biomethanation performance at retention times as low as 25 h. Retention times shorter than 25 h caused prevalent bacterial populations and methane production to decrease, and intermediary carbon metabolites accumulated in the following order: acetate, butyrate, propionate, lactate, ethanol, and lactose. Bacterial species dominated in the chemostat as a function of their enhanced substrate uptake and growth kinetic properties. The substrate uptake kinetic properties displayed by the mixed chemostat population were equivalent to those of individual species measured in pure culture, whereas the growth kinetic properties of species in mixed culture were better than those measured in pure culture. A designed starter culture consisting of Leuconostoc mesenteroides, Desulfovibrio vulgaris, Methanosarcina barkeri, and Methanobacterium formicicum displayed biomethanation performance, which was similar to that of a diverse adapted mixed-culture inoculum, in a continuous contact digestor system to which 10 g of dry whey per liter was added. Preserved starter cultures were developed and used as inocula for the start-up of a continuous anaerobic digestion process that was effective for biomethanation of raw whey at a retention time of 100 h. Images PMID:16347341

  19. Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements

    PubMed Central

    Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

    2015-01-01

    This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469

  20. Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements.

    PubMed

    Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

    2015-01-01

    This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L(-1)·d(-1) of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%-62.2% higher than with NaOH-pretreatment alone and 22.2%-56.3% higher than with untreated corn stover. The best combination was obtained 5-9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469

  1. Estimating Gas and Rock Outburst Risk on the Basis of Knowledge and Experience - The Expert System Based on Fuzzy Logic

    NASA Astrophysics Data System (ADS)

    Skoczylas, Norbert

    2014-03-01

    The Author endeavored to consult some of the Polish experts who deal with assessing and preventing outburst hazards as to their knowledge and experience. On the basis of this knowledge, an expert system, based on fuzzy logic, was created. The system allows automatic assessment of outburst hazard. The work was completed in two stages. The first stage involved researching relevant sources and rules concerning outburst hazard, and, subsequently, determining a number of parameters measured or observed in the mining industry that are potentially connected with the outburst phenomenon and can be useful when estimating outburst hazard. Then, the Author contacted selected experts who are actively involved in preventing outburst hazard, both in the industry and science field. The experts were anonymously surveyed, which made it possible to select the parameters which are the most essential in assessing outburst hazard. The second stage involved gaining knowledge from the experts by means of a questionnaire-interview. Subjective opinions on estimating outburst hazard on the basis of the parameters selected during the first stage were then systematized using the structures typical of the expert system based on fuzzy logic. Autor współpracował z polskimi ekspertami związanymi z badaniami i zwalczaniem zagrożenia wyrzutowego. W wyniku współpracy pozyskał ich wiedzę i doświadczenie, na bazie której stworzył system ekspercki, oparty na logice rozmytej. System umożliwia automatyczną ocenę zagrożenia wyrzutowego. Prace przebiegały w dwóch etapach. Pierwszy etap polegał na określeniu istotnych parametrów mierzonych, bądź obserwowanych w górnictwie, które mają silny związek ze stanem zagrożenia wyrzutowego. Następnie wybrana grupa ekspertów dokonała oceny stanu zagrożenia wyrzutowego, bazując na parametrach które w pierwszym etapie uznane zostały za najistotniejsze. Pozwoliło to zbudować system ekspercki na bazie logiki rozmytej, który okre

  2. Effect of protective release coatings on the basis of superdispersersed zirconium oxide powder on the formation of gas defects in bronze casting

    NASA Astrophysics Data System (ADS)

    Martyushev, Nikita V.; Risto, Nikolay A.

    2014-10-01

    This paper investigates the use of nanopowders in the composition of foundry coatings when casting leaded tin bronzes. Influence of the composition of the applied protective coating on surface finish is studied. The effects of the coatings of the following compositions are compared: non-stick coating (a mixture of low-dispersed chromium oxide powder and heat-treated vegetable oil); non-stick lubricant ASPF-2/RgU on the basis of low- dispersed graphite powder and heat-treated vegetable oil; patent #2297300 (a mixture of superdispersed zirconium dioxide powder with industrial oil). It is demonstrated that application of foundry coatings containing superdispersed metal oxide powders with low thermal conductivity makes it possible to significantly reduce irregularities and eliminate gas porosity on the surface of tin-leaded bronze castings.

  3. Numerical modeling of the sound propagation through a rarefied gas in a semi-infinite space on the basis of linearized kinetic equation.

    PubMed

    Sharipov, Felix; Kalempa, Denize

    2008-10-01

    The sound propagation through a rarefied gas is investigated on the basis of the linearized kinetic equation. A plate oscillating in the direction normal to its own plane is considered as a sound wave source. It is assumed a fully established oscillation so that the solution of the kinetic equation depends on time harmonically, while its dependence on the spatial coordinates is obtained numerically. The problem is solved over a wide range of the oscillation speed parameter defined as a ratio of the intermolecular collision frequency to the sound frequency. In order to evaluate the influence of the momentum and energy accommodation coefficients on the solution of the problem, the Cercignani-Lampis scattering kernel is applied as the boundary condition. An analysis of wave characteristics near the source surface shows that they are significantly different from those far from the surface even if the oscillation is slow, i.e., the solution is not harmonic in the space. PMID:19062839

  4. Enhanced biohydrogen and subsequent biomethane production from sugarcane bagasse using nano-titanium dioxide pretreatment.

    PubMed

    Jafari, Omid; Zilouei, Hamid

    2016-08-01

    Nano-titanium dioxide (nanoTiO2) under ultraviolet irradiation (UV) followed by dilute sulfuric acid hydrolysis of sugarcane bagasse was used to enhance the production of biohydrogen and biomethane in a consecutive dark fermentation and anaerobic digestion. Different concentrations of 0.001, 0.01, 0.1 and 1g nanoTiO2/L under different UV times of 30, 60, 90 and 120min were used. Sulfuric acid (2%v/v) at 121°C was used for 15, 30 and 60min to hydrolyze the pretreated bagasse. For acidic hydrolysis times of 15, 30 and 60min, the highest total free sugar values were enhanced by 260%, 107%, and 189%, respectively, compared to samples without nanoTiO2 pretreatment. The highest hydrogen production samples for the same acidic hydrolysis times showed 88%, 127%, and 25% enhancement. The maximum hydrogen production of 101.5ml/g VS (volatile solids) was obtained at 1g nanoTiO2/L and 120min UV irradiation followed by 30min acid hydrolysis. PMID:27208737

  5. A Review on the Valorization of Macroalgal Wastes for Biomethane Production.

    PubMed

    Barbot, Yann Nicolas; Al-Ghaili, Hashem; Benz, Roland

    2016-01-01

    The increased use of terrestrial crops for biofuel production and the associated environmental, social and ethical issues have led to a search for alternative biomass materials. Terrestrial crops offer excellent biogas recovery, but compete directly with food production, requiring farmland, fresh water and fertilizers. Using marine macroalgae for the production of biogas circumvents these problems. Their potential lies in their chemical composition, their global abundance and knowledge of their growth requirements and occurrence patterns. Such a biomass industry should focus on the use of residual and waste biomass to avoid competition with the biomass requirements of the seaweed food industry, which has occurred in the case of terrestrial biomass. Overabundant seaweeds represent unutilized biomass in shallow water, beach and coastal areas. These eutrophication processes damage marine ecosystems and impair local tourism; this biomass could serve as biogas feedstock material. Residues from biomass processing in the seaweed industry are also of interest. This is a rapidly growing industry with algae now used in the comestible, pharmaceutical and cosmetic sectors. The simultaneous production of combustible biomethane and disposal of undesirable biomass in a synergistic waste management system is a concept with environmental and resource-conserving advantages. PMID:27338422

  6. Anaerobic Co-Digestion of Microalgae Scenedesmus sp. and TWAS for Biomethane Production.

    PubMed

    Garoma, Temesgen; Nguyen, Don

    2016-01-01

    The paper investigated the feasibility of biomethane (bio-CH4) production from the anaerobic co-digestion of the microalgae Scenedesmus quadricauda (S. quadricauda) and thickened waste activated sludge (TWAS). The concept was tested in bench-scale anaerobic digesters by varying the proportions of volatile solids (VS) loading from S. quadricauda and TWAS and two critical operational parameters, temperature and alkalinity. The CH(4) production for the various S. quadricauda and TWAS proportions ranged from 234 to 318 mL/g of chemical oxygen demand (COD) digested and 329 to 530 mL/g of VS digested at 35 °C. The reductions in total solids (TS), COD, and VS ranged from 25 to 44%, 46 to 53%, and 40 to 53%, respectively. Temperature had a significant effect on CH(4) production, lower temperatures greatly reduced CH(4) production. No significant difference in CH(4) production was observed for experiments conducted at alkalinity levels of 70, 1630, and 3200 mg/L as CaCO(3). PMID:26803022

  7. Use of a marine microbial community as inoculum for biomethane production.

    PubMed

    Fistarol, Giovana O; Rosato, Mario; Thompson, Fabiano L; do Valle, Rogerio de A B; Garcia-BlairsyReina, Guillermo; Salomon, Paulo S

    2016-01-01

    Marine substrates are prominent candidates for the production of biofuels, especially for biogas, which is a well-established technology that accepts different types of substrates for its production. However, the use of marine substrates in bioreactors may cause inhibition of methanogenic bacteria due to the addition of seasalts. Here, we explore a simple and economically viable way to circumvent the problem of inoculum inhibition. Based on the current knowledge of the diversity of microorganisms in marine sediments, we tested the direct use of methanogenic bacteria from an anoxic marine environment as inoculum for biomethane production. Both marine and freshwater substrates were added to this inoculum. No pretreatment (that may have enhanced methane production, but would have made the process more expensive) was applied either to the inoculum or to the substrates. For comparison, the same substrates were added to a standard inoculum (cow manure). Both the marine inoculum and cow manure produced methane by anaerobic digestion of the substrates added. The highest methane production (0.299 m(3) kg VS(-1)) was obtained by adding marine microalgae biomass (Chlorella sp. and Synechococcus sp.) to the marine inoculum. No inhibitory effects were observed due to differences in salinity between the inocula and substrates. Our results indicate the potential of using both marine inoculum and substrates for methane production. PMID:26227555

  8. A Review on the Valorization of Macroalgal Wastes for Biomethane Production

    PubMed Central

    Barbot, Yann Nicolas; Al-Ghaili, Hashem; Benz, Roland

    2016-01-01

    The increased use of terrestrial crops for biofuel production and the associated environmental, social and ethical issues have led to a search for alternative biomass materials. Terrestrial crops offer excellent biogas recovery, but compete directly with food production, requiring farmland, fresh water and fertilizers. Using marine macroalgae for the production of biogas circumvents these problems. Their potential lies in their chemical composition, their global abundance and knowledge of their growth requirements and occurrence patterns. Such a biomass industry should focus on the use of residual and waste biomass to avoid competition with the biomass requirements of the seaweed food industry, which has occurred in the case of terrestrial biomass. Overabundant seaweeds represent unutilized biomass in shallow water, beach and coastal areas. These eutrophication processes damage marine ecosystems and impair local tourism; this biomass could serve as biogas feedstock material. Residues from biomass processing in the seaweed industry are also of interest. This is a rapidly growing industry with algae now used in the comestible, pharmaceutical and cosmetic sectors. The simultaneous production of combustible biomethane and disposal of undesirable biomass in a synergistic waste management system is a concept with environmental and resource-conserving advantages. PMID:27338422

  9. Suitability of different containers for the sampling and storage of biogas and biomethane for the determination of the trace-level impurities--A review.

    PubMed

    Arrhenius, Karine; Brown, Andrew S; van der Veen, Adriaan M H

    2016-01-01

    The traceable and accurate measurement of biogas impurities is essential in order to robustly assess compliance with the specifications for biomethane being developed by CEN/TC408. An essential part of any procedure aiming to determinate the content of impurities is the sampling and the transfer of the sample to the laboratory. Key issues are the suitability of the sample container and minimising the losses of impurities during the sampling and analysis process. In this paper, we review the state-of-the-art in biogas sampling with the focus on trace impurities. Most of the vessel suitability studies reviewed focused on raw biogas. Many parameters need to be studied when assessing the suitability of vessels for sampling and storage, among them, permeation through the walls, leaks through the valves or physical leaks, sorption losses and adsorption effects to the vessel walls, chemical reactions and the expected initial concentration level. The majority of these studies looked at siloxanes, for which sampling bags, canisters, impingers and sorbents have been reported to be fit-for-purpose in most cases, albeit with some limitations. We conclude that the optimum method requires a combination of different vessels to cover the wide range of impurities commonly found in biogas, which have a wide range of boiling points, polarities, water solubilities, and reactivities. The effects from all the parts of the sampling line must be considered and precautions must be undertaken to minimize these effects. More practical suitability tests, preferably using traceable reference gas mixtures, are needed to understand the influence of the containers and the sampling line on sample properties and to reduce the uncertainty of the measurement. PMID:26703250

  10. Biomethane production from vinasse in upflow anaerobic sludge blanket reactors inoculated with granular sludge.

    PubMed

    Barros, Valciney Gomes de; Duda, Rose Maria; Oliveira, Roberto Alves de

    2016-01-01

    The main objective of this study was to evaluate the anaerobic conversion of vinasse into biomethane with gradual increase in organic loading rate (OLR) in two upflow anaerobic sludge blanket (UASB) reactors, R1 and R2, with volumes of 40.5 and 21.5L in the mesophilic temperature range. The UASB reactors were operated for 230 days with a hydraulic detection time (HDT) of 2.8d (R1) and 2.8-1.8d (R2). The OLR values applied in the reactors were 0.2-7.5gtotalCOD (Ld)(-1) in R1 and 0.2-11.5gtotalCOD (Ld)(-1) in R2. The average total chemical oxygen demand (totalCOD) removal efficiencies ranged from 49% to 82% and the average conversion efficiencies of the removed totalCOD into methane were 48-58% in R1 and 39-65% in R2. The effluent recirculation was used for an OLR above 6gtotalCOD (Ld)(-1) in R1 and 8gtotalCOD (Ld)(-1) in R2 and was able to maintain the pH of the influent in R1 and R2 in the range from 6.5 to 6.8. However, this caused a decrease for 53-39% in the conversion efficiency of the removed totalCOD into methane in R2 because of the increase in the recalcitrant COD in the influent. The largest methane yield values were 0.181 and 0.185 (L) CH4 (gtotalCOD removed)(-1) in R1 and R2, respectively. These values were attained after 140 days of operation with an OLR of 5.0-7.5gtotalCOD (Ld)(-1) and totalCOD removal efficiencies around 70 and 80%. PMID:27289246

  11. Biohydrogen, biomethane and bioelectricity as crucial components of biorefinery of organic wastes: a review.

    PubMed

    Poggi-Varaldo, Héctor M; Munoz-Paez, Karla M; Escamilla-Alvarado, Carlos; Robledo-Narváez, Paula N; Ponce-Noyola, M Teresa; Calva-Calva, Graciano; Ríos-Leal, Elvira; Galíndez-Mayer, Juvencio; Estrada-Vázquez, Carlos; Ortega-Clemente, Alfredo; Rinderknecht-Seijas, Noemí F

    2014-05-01

    the inverse cascade. Finally, biohydrogen, biomethane and bioelectricity could contribute to significant improvements for solid organic waste management in agricultural regions, as well as in urban areas. PMID:24742981

  12. Reducing Greenhouse Gas Emissions in Grassland Ecosystems of the Central Lithuania: Multi-Criteria Evaluation on a Basis of the ARAS Method

    PubMed Central

    Balezentiene, Ligita; Kusta, Albinas

    2012-01-01

    N2O, CH4, and CO2 are potential greenhouse gas (GHG) contributing to climate change; therefore, solutions have to be sought to reduce their emission from agriculture. This work evaluates GHG emission from grasslands submitted to different mineral fertilizers during vegetation period (June–September) in two experimental sites, namely, seminatural grassland (8 treatments of mineral fertilizers) and cultural pasture (intensively managed) in the Training Farm of the Lithuanian University of Agriculture. Chamber method was applied for evaluation of GHG emissions on the field scale. As a result, soil chemical composition, compactness, temperature, and gravimetric moisture as well as biomass yield of fresh and dry biomass and botanical composition, were assessed during the research. Furthermore, a simulation of multi-criteria assessment of sustainable fertilizers management was carried out on a basis of ARAS method. The multicriteria analysis of different fertilizing regimes was based on a system of environmental and productivity indices. Consequently, agroecosystems of cultural pasture (N180P120K150) and seminatural grassland fertilizing rates N180P120K150 and N60P40K50 were evaluated as the most sustainable alternatives leading to reduction of emissions between biosphere-atmosphere and human-induced biogenic pollution in grassland ecosystems, thus contributing to improvement of countryside environment. PMID:22645463

  13. Phenotypic plasticity of gas exchange pattern and water loss in Scarabaeus spretus (Coleoptera: Scarabaeidae): deconstructing the basis for metabolic rate variation.

    PubMed

    Terblanche, John S; Clusella-Trullas, Susana; Chown, Steven L

    2010-09-01

    Investigation of gas exchange patterns and modulation of metabolism provide insight into metabolic control systems and evolution in diverse terrestrial environments. Variation in metabolic rate in response to environmental conditions has been explained largely in the context of two contrasting hypotheses, namely metabolic depression in response to stressful or resource-(e.g. water) limited conditions, or elevation of metabolism at low temperatures to sustain life in extreme conditions. To deconstruct the basis for metabolic rate changes in response to temperature variation, here we undertake a full factorial study investigating the longer- and short-term effects of temperature exposure on gas exchange patterns. We examined responses of traits of gas exchange [standard metabolic rate (SMR); discontinuous gas exchange (DGE) cycle frequency; cuticular, respiratory and total water loss rate (WLR)] to elucidate the magnitude and form of plastic responses in the dung beetle, Scarabaeus spretus. Results showed that short- and longer-term temperature variation generally have significant effects on SMR and WLR. Overall, acclimation to increased temperature led to a decline in SMR (from 0.071+/-0.004 ml CO(2) h(-1) in 15 degrees C-acclimated beetles to 0.039+/-0.004 ml CO(2) h(-1) in 25 degrees C-acclimated beetles measured at 20 degrees C) modulated by reduced DGE frequency (15 degrees C acclimation: 0.554+/-0.027 mHz, 20 degrees C acclimation: 0.257+/-0.030 mHz, 25 degrees C acclimation: 0.208+/-0.027 mHz recorded at 20 degrees C), reduced cuticular WLRs (from 1.058+/-0.537 mg h(-1) in 15 degrees C-acclimated beetles to 0.900+/-0.400 mg h(-1) in 25 degrees C-acclimated beetles measured at 20 degrees C) and reduced total WLR (from 4.2+/-0.5 mg h(-1) in 15 degrees C-acclimated beetles to 3.1+/-0.5 mg h(-1) in 25 degrees C-acclimated beetles measured at 25 degrees C). Respiratory WLR was reduced from 2.25+/-0.40 mg h(-1) in 15 degrees C-acclimated beetles to 1.60+/-0.40 mg h

  14. Effect of cobalt supplementation and fractionation on the biological response in the biomethanization of Olive Mill Solid Waste.

    PubMed

    Pinto-Ibieta, F; Serrano, A; Jeison, D; Borja, R; Fermoso, F G

    2016-07-01

    Due to the low trace metals concentration in the Olive Mill Solid Waste (OMSW), a proposed strategy to improve its biomethanization is the supplementation of key metals to enhance the microorganism activity. Among essential trace metals, cobalt has been reported to have a crucial role in anaerobic degradation. This study evaluates the effect of cobalt supplementation to OMSW, focusing on the connection between fractionation of cobalt in the system and the biological response. The highest biological responses was found in a range from 0.018 to 0.035mg/L of dissolved cobalt (0.24-0.65mg total cobalt/L), reaching improvements up to 23% and 30% in the methane production rate and the methane yield coefficient, respectively. It was found that the dissolved cobalt fraction is more accurately related with the biological response than the total cobalt. The total cobalt is distorted by the contribution of dissolved and non-dissolved inert fractions. PMID:26998798

  15. The effect of storage conditions on microbial community composition and biomethane potential in a biogas starter culture.

    PubMed

    Hagen, Live Heldal; Vivekanand, Vivekanand; Pope, Phillip B; Eijsink, Vincent G H; Horn, Svein J

    2015-07-01

    A new biogas process is initiated by adding a microbial community, typically in the form of a sample collected from a functional biogas plant. This inoculum has considerable impact on the initial performance of a biogas reactor, affecting parameters such as stability, biogas production yields and the overall efficiency of the anaerobic digestion process. In this study, we have analyzed changes in the microbial composition and performance of an inoculum during storage using barcoded pyrosequencing of bacterial and archaeal 16S ribosomal RNA (rRNA) genes, and determination of the biomethane potential, respectively. The inoculum was stored at room temperature, 4 and -20 °C for up to 11 months and cellulose was used as a standard substrate to test the biomethane potential. Storage up to 1 month resulted in similar final methane yields, but the rate of methane production was reduced by storage at -20 °C. Longer storage times resulted in reduced methane yields and slower production kinetics for all storage conditions, with room temperature and frozen samples consistently giving the best and worst performance, respectively. Both storage time and temperature affected the microbial community composition and methanogenic activity. In particular, fluctuations in the relative abundance of Bacteroidetes were observed. Interestingly, a shift from hydrogenotrophic methanogens to methanogens with the capacity to perform acetoclastic methanogensis was observed upon prolonged storage. In conclusion, this study suggests that biogas inocula may be stored up to 1 month with low loss of methanogenic activity, and identifies bacterial and archaeal species that are affected by the storage. PMID:25947246

  16. Development of biological coal gasification (MicGAS Process)

    SciTech Connect

    Walia, D.S.; Srivastava, K.C.

    1994-10-01

    The overall goal of the project is to develop an advanced, clean coal biogasification (MicGAS) Process. The objectives of the research during FY 1993--94 were to: (1) enhance kinetics of methane production (biogasification, biomethanation) from Texas lignite (TxL) by the Mic-1 consortium isolated and developed at ARCTECH, (2) increase coal solids loading, (3) optimize medium composition, and (4) reduce retention time. A closer analysis of the results described here indicate that biomethanation of TxL at >5% solids loading is feasible through appropriate development of nutrient medium and further adaptation of the microorganisms involved in this process. Further understanding of the inhibitory factors and some biochemical manipulations to overcome those inhibitions will hasten the process considerably. Results are discussed on the following: products of biomethanation and enhance of methane production including: bacterial adaptation; effect of nutrient amendment substitutes; effects of solids loading; effect of initial pH of the culture medium; effect of hydrogen donors and carbon balance.

  17. Experimental and life cycle assessment analysis of gas emission from mechanically–biologically pretreated waste in a landfill with energy recovery

    SciTech Connect

    Di Maria, Francesco Sordi, Alessio; Micale, Caterina

    2013-11-15

    Highlights: • Bio-methane landfill emissions from different period (0, 4, 8, 16 weeks) MTB waste have been evaluated. • Electrical energy recoverable from landfill gas ranges from 11 to about 90 kW h/tonne. • Correlation between oxygen uptake, energy recovery and anaerobic gas production shows R{sup 2} ranging from 0.78 to 0.98. • LCA demonstrate that global impact related to gaseous emissions achieve minimum for 4 week of MBT. - Abstract: The global gaseous emissions produced by landfilling the Mechanically Sorted Organic Fraction (MSOF) with different weeks of Mechanical Biological Treatment (MBT) was evaluated for an existing waste management system. One MBT facility and a landfill with internal combustion engines fuelled by the landfill gas for electrical energy production operate in the waste management system considered. An experimental apparatus was used to simulate 0, 4, 8 and 16 weeks of aerobic stabilization and the consequent biogas potential (Nl/kg) of a large sample of MSOF withdrawn from the full-scale MBT. Stabilization achieved by the waste was evaluated by dynamic oxygen uptake and fermentation tests. Good correlation coefficients (R{sup 2}), ranging from 0.7668 to 0.9772, were found between oxygen uptake, fermentation and anaerobic test values. On the basis of the results of several anaerobic tests, the methane production rate k (year{sup −1}) was evaluated. k ranged from 0.436 to 0.308 year{sup −1} and the bio-methane potential from 37 to 12 N m{sup 3}/tonne, respectively, for the MSOF with 0 and 16 weeks of treatment. Energy recovery from landfill gas ranged from about 11 to 90 kW h per tonne of disposed MSOF depending on the different scenario investigated. Life cycle analysis showed that the scenario with 0 weeks of pre-treatment has the highest weighted global impact even if opposite results were obtained with respect to the single impact criteria. MSOF pre-treatment periods longer than 4 weeks showed rather negligible variation

  18. Evaluating biomethane production from anaerobic mono- and co-digestion of food waste and floatable oil (FO) skimmed from food waste.

    PubMed

    Meng, Ying; Li, Sang; Yuan, Hairong; Zou, Dexun; Liu, Yanping; Zhu, Baoning; Chufo, Akiber; Jaffar, Muhammad; Li, Xiujin

    2015-06-01

    Batch anaerobic digestion was employed to investigate the performance of the floatable oil (FO) skimmed from food waste (FW) and the effect of different FO concentrations (5, 10, 20, 30, 40 and 50g/L) on biomethane production and system stability. FO and FO+FW were mono-digested and co-digested. The results showed that FO and FO+FW could be well anaerobically converted to biomethane in appropriate loads. For the mono-digestions of FO, the biomethane yield, TS and VS reduction achieved 607.7-846.9mL/g, 69.7-89% and 84.5-92.8%, respectively, when FO concentration was 5-40g/L. But the mono-digestion appeared instability when FO concentration was 50g/L. For the co-digestions of FW+FO, TS and VS reductions reached 70.7-86.1% and 87.5-91.4%, respectively, when FO concentration was 5-30g/L. However, the inhibition occurred when FO concentrations increased to 40-50g/L. The maximal FO loads of 40g/L and 30g/L were hence suggested for efficient mono-digestions and co-digestions of FO and FO+FW. PMID:25746472

  19. Bio-hydrogen and bio-methane potentials of skim latex serum in batch thermophilic two-stage anaerobic digestion.

    PubMed

    Jariyaboon, Rattana; O-Thong, Sompong; Kongjan, Prawit

    2015-12-01

    Anaerobic digestion by two-stage process, containing hydrogen-producing (acidogenic) first stage and methanogenic second stage, has been proposed to degrade substrates which are difficult to be treated by single stage anaerobic digestion process. This research was aimed to evaluate the bio-hydrogen and the bio-methane potentials (BHP and BMP) of skim latex serum (SLS) by using sequential batch hydrogen and methane cultivations at thermophilic conditions (55°C) and with initial SLS concentrations of 37.5-75.0% (v/v). The maximal 1.57 L H2/L SLS for BHP and 12.2L CH4/L SLS for BMP were both achieved with 60% (v/v) SLS. The dominant hydrogen-producing bacteria in the H2 batch reactor were Thermoanaerobacterium sp. and Clostrdium sp. Meanwhile, the CH4 batch reactor was dominated by the methanogens Methanosarcina mazei and Methanothermobacter defluvii. The results demonstrate that SLS can be degraded by conversion to form hydrogen and methane, waste treatment and bioenergy production are thus combined. PMID:26386423

  20. The effect of seasonal variation on biomethane production from seaweed and on application as a gaseous transport biofuel.

    PubMed

    Tabassum, Muhammad Rizwan; Xia, Ao; Murphy, Jerry D

    2016-06-01

    Biomethane produced from seaweed may be used as a transport biofuel. Seasonal variation will have an effect on this industry. Laminaria digitata, a typical Irish brown seaweed species, shows significant seasonal variation both in proximate, ultimate and biochemical composition. The characteristics in August were optimal with the lowest level of ash (20% of volatile solids), a C:N ratio of 32 and the highest specific methane yield measured at 327LCH4kgVS(-1), which was 72% of theoretical yield. The highest yield per mass collected of 53m(3)CH4t(-1) was achieved in August, which is 4.5 times higher than the lowest value, obtained in December. A seaweed cultivation area of 11,800ha would be required to satisfy the 2020 target for advanced biofuels in Ireland, of 1.25% renewable energy supply in transport (RES-T) based on the optimal gross energy yield obtained in August (200GJha(-1)yr(-1)). PMID:26970924

  1. Biomethanation of vegetable market waste in an anaerobic baffled reactor: Effect of effluent recirculation and carbon mass balance analysis.

    PubMed

    Gulhane, Madhuri; Khardenavis, Anshuman A; Karia, Sneha; Pandit, Prabhakar; Kanade, Gajanan S; Lokhande, Satish; Vaidya, Atul N; Purohit, Hemant J

    2016-09-01

    In the present study, feasibility of biomethanation of vegetable market waste in a 4-chambered anaerobic baffled reactor (ABR) was investigated at 30d hydraulic retention time and organic loading rate of 0.5gVS/L/d for one year. Indicators of process stability viz., butyrate/acetate and propionate/acetate ratios were consistent with phase separation in the different chambers, which remained unaltered even during recirculation of effluent. Chemical oxygen demand (COD) and volatile solids (VS) removal efficiencies were observed to be consistently high (above 90%). Corresponding biogas and methane yields of 0.7-0.8L/g VS added/d and 0.42-52L/g VS added/d respectively were among the highest reported in case of AD of vegetable waste in an ABR. Process efficiency of the ABR for vegetable waste methanation, which is indicated by carbon recovery factor showed that, nearly 96.7% of the input carbon considered for mass balance was accounted for in the product. PMID:27133362

  2. Well-to-Wheels analysis of landfill gas-based pathways and their addition to the GREET model.

    SciTech Connect

    Mintz, M.; Han, J.; Wang, M.; Saricks, C.; Energy Systems

    2010-06-30

    Today, approximately 300 million standard cubic ft/day (mmscfd) of natural gas and 1600 MW of electricity are produced from the decomposition of organic waste at 519 U.S. landfills (EPA 2010a). Since landfill gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, compressed natural gas (CNG) produced from LFG consumes up to 185,000 Btu of fossil fuel and generates from 1.5 to 18.4 kg of carbon dioxide-equivalent (CO{sub 2}e) emissions per million Btu of fuel on a 'well-to-wheel' (WTW) basis. This compares with approximately 1.1 million Btu and 78.2 kg of CO{sub 2}e per million Btu for CNG from fossil natural gas and 1.2 million Btu and 97.5 kg of CO{sub 2}e per million Btu for petroleum gasoline. Because of the additional energy required for liquefaction, LFG-based liquefied natural gas (LNG) requires more fossil fuel (222,000-227,000 Btu/million Btu WTW) and generates more GHG emissions (approximately 22 kg CO{sub 2}e /MM Btu WTW) if grid electricity is used for the liquefaction process. However, if some of the LFG is used to generate electricity for gas cleanup and liquefaction (or compression, in the case of CNG), vehicle fuel produced from LFG can have no fossil fuel input and only minimal GHG emissions (1.5-7.7 kg CO{sub 2}e /MM Btu) on a WTW basis. Thus, LFG-based natural gas can be one of the lowest GHG-emitting fuels for light- or heavy-duty vehicles. This report discusses the size and scope of biomethane resources from landfills and the pathways by which those resources can be turned into and utilized as vehicle fuel. It includes characterizations of the LFG stream and the processes used to convert low-Btu LFG into high-Btu renewable natural gas (RNG); documents the conversion efficiencies and losses of those processes, the choice of processes modeled in GREET, and other assumptions used to construct GREET pathways; and presents GREET results by pathway stage. GREET estimates of well-to-pump (WTP), pump

  3. Surfactants in anaerobic digestion of cheese whey, poultry waste, and cattle dung for improved biomethanation

    SciTech Connect

    Desai, M.; Madamwar, D.

    1994-05-01

    To obtain enriched methane content and improve the anaerobic digestion of a mixture of cattle dung, poultry waste and cheese whey, with enriched methane content, the effect of various surfactants was studied. Among the surfactants tested, Tween 80 and sodium lauryl sulphate showed the maximum enhancement in gas production as well as methane content, indicating better process performance. The Tween 80 dosed digester (300 {mu}L/L) produced about 3.5 L gas/L of digester/d with 70% methane. Results also indicated increased percent COD reduction in the presence of Tween 80. 13 refs., 2 figs.

  4. Regularities of heat transfer in the gas layers of a steam boiler furnace flame. Part II. Gas layer radiation laws and the procedure for calculating heat transfer in furnaces, fire boxes, and combustion chambers developed on the basis of these laws

    NASA Astrophysics Data System (ADS)

    Makarov, A. N.

    2014-10-01

    The article presents the results stemming from the scientific discovery of laws relating to radiation from the gas layers generated during flame combustion of fuel and when electric arc burns in electric-arc steel-melting furnaces. The procedure for calculating heat transfer in electric-arc and torch furnaces, fire-boxes, and combustion chambers elaborated on the basis of this discovery is described.

  5. Ammonia-LCFA synergetic co-inhibition effect in manure-based continuous biomethanation process.

    PubMed

    Wang, Han; Fotidis, Ioannis A; Angelidaki, Irini

    2016-06-01

    In the current study it has been hypothesized that, when organic loading of an anaerobic reactor is increased, the additional cell biomass biosynthesis would capture more ammonia nitrogen and thereby reduce the ammonia toxicity. Therefore, the alleviation of the toxicity of high ammonia levels using lipids (glycerol trioleate-GTO) or carbohydrates (glucose-GLU) as co-substrates in manure-based thermophilic continuous stirred-tank reactors (R(GTO) and R(GLU), respectively) was tested. At 5gNH4(+)-NL(-1), relative methane production of R(GTO) and R(GLU), was 10.5% and 41% compared to the expected uninhibited production, respectively. At the same time control reactor (R(CTL)), only fed with manure, reached 32.7% compared to the uninhibited basis production. Therefore, it seems that using lipids to counteract the ammonia effect in CSTR reactors creates an "ammonia-LCFA (long chain fatty acids) synergetic co-inhibition" effect. Moreover, co-digestion with glucose in R(GLU) was more robust to ammonia toxicity compared to R(CTL). PMID:26985628

  6. Environmental assessment of two different crop systems in terms of biomethane potential production.

    PubMed

    Bacenetti, Jacopo; Fusi, Alessandra; Negri, Marco; Guidetti, Riccardo; Fiala, Marco

    2014-01-01

    The interest in renewable energy sources has gained great importance in Europe due to the need to reduce fossil energy consumption and greenhouse gas emissions, as required by the Renewable Energy Directive (RED) of the European Parliament. The production of energy from energy crops appears to be consistent with RED. The environmental impact related to this kind of energy primarily originates from crop cultivation. This research aimed to evaluate the environmental impact of different crop systems for biomass production: single and double crop. The environmental performances of maize and maize plus wheat were assessed from a life cycle perspective. Two alternative scenarios considering different yields, crop management, and climatic conditions, were also addressed. One normal cubic metre of potential methane was chosen as a functional unit. Methane potential production data were obtained through lab experimental tests. For both of the crop systems, the factors that have the greatest influence on the overall environmental burden are: fertilizer emissions, diesel fuel emissions, diesel fuel production, and pesticide production. Notwithstanding the greater level of methane potential production, the double crop system appears to have the worse environmental performance with respect to its single crop counterpart. This result is due to the bigger quantity of inputs needed for the double crop system. Therefore, the greater amount of biomass (silage) obtained through the double crop system is less than proportional to the environmental burden that results from the bigger quantity of inputs requested for double crop. PMID:23994820

  7. [Optimization on slow-release inhibition of biomethane and the kinetics model of diffusion].

    PubMed

    Zhang, Li-jie; Zhao, Tian-tao; Zhao, You-cai; Deng, Yu-ping

    2010-07-01

    The diffusion mechanism of acetylene,which can inhibit the activity of methanogens, was studied. Paraffin wax and rosin were used as matrix of slow-release and calcium carbide was used as inhibition material. Based on the T. Higuchi equation and the characteristics of slow-release inhibitors, a mechanism model was derived. Moreover, the effective diffusion coefficients (De) can be acquired by this model. During the diffusion process, the reaction heat of calcium carbide and water could make acetylene gas expansion and caused the slow-release inhibitors expansion if the hardness of the slow-release inhibitors is inadequate. The hardness and compactness were enhanced and the effective diffusion coefficients reached 2.2849 x 10(-8) cm2/min (R2 = 0.9901) when the mass faction of rosin was 20% and the mass ratio of matrix to calcium carbide was 1/1. Hence,the mitigation the methane generation with municipal solid waste (MSW) can be achieved by the technology of slow-release inhibition. PMID:20825047

  8. Upgraded biogas from municipal solid waste for natural gas substitution and CO{sub 2} reduction – A case study of Austria, Italy, and Spain

    SciTech Connect

    Starr, Katherine; Villalba, Gara; Gabarrell, Xavier

    2015-04-15

    Highlights: • Biogas can be upgraded to create biomethane, a substitute to natural gas. • Biogas upgrading was applied to landfills and anaerobic digestors in 3 countries. • Up to 0.6% of a country’s consumption of natural gas could be replaced by biomethane. • Italy could save 46% of the national CO{sub 2} emissions attributed to the waste sector. • Scenarios were created to increase biomethane production. - Abstract: Biogas is rich in methane and can be further purified through biogas upgrading technologies, presenting a viable alternative to natural gas. Landfills and anaerobic digestors treating municipal solid waste are a large source of such biogas. They therefore offer an attractive opportunity to tap into this potential source of natural gas while at the same time minimizing the global warming impact resulting from methane emissions in waste management schemes (WMS) and fossil fuel consumption reduction. This study looks at the current municipal solid waste flows of Spain, Italy, and Austria over one year (2009), in order to determine how much biogas is generated. Then it examines how much natural gas could be substituted by using four different biogas upgrading technologies. Based on current waste generation rates, exploratory but realistic WMS were created for each country in order to maximize biogas production and potential for natural gas substitution. It was found that the potential substitution of natural gas by biogas resulting from the current WMS seems rather insignificant: 0.2% for Austria, 0.6% for Italy and 0.3% for Spain. However, if the WMS is redesigned to maximize biogas production, these figures can increase to 0.7% for Austria, 1% for Italy and 2% for Spain. Furthermore, the potential CO{sub 2} reduction as a consequence of capturing the biogas and replacing fossil fuel can result in up to a 93% reduction of the annual national waste greenhouse gas emissions of Spain and Italy.

  9. Basis selection in LOBPCG

    NASA Astrophysics Data System (ADS)

    Hetmaniuk, U.; Lehoucq, R.

    2006-10-01

    The purpose of our paper is to discuss basis selection for Knyazev's locally optimal block preconditioned conjugate gradient (LOBPCG) method. An inappropriate choice of basis can lead to ill-conditioned Gram matrices in the Rayleigh-Ritz analysis that can delay convergence or produce inaccurate eigenpairs. We demonstrate that the choice of basis is not merely related to computing in finite precision arithmetic. We propose a representation that maintains orthogonality of the basis vectors and so has excellent numerical properties.

  10. NREL Biomethane GIS Data

    DOE Data Explorer

    Milbrandt, Anelia

    2016-06-15

    This dataset contains information about the biomass resources generated by county in the United States. It includes the following feedstock categories: crop residues, forest residues, primary mill residues, secondary mill residues, and urban wood waste. The estimates are based on county-level statistics and/or point-source data gathered from the U.S. Department of Agriculture (USDA), USDA Forest Service, EPA and other organizations, which are further processed using relevant assumptions and conversions.

  11. BIOMETHANE FOR TRANSPORTATION

    EPA Science Inventory

    During phase I of this project we designed and built two different small-scale biogas refineries. The first design used a caustic absorption system. Our initial results showed an increase in CH4 (methane) content from 60.50 Mol% in the raw biogas to 93.62 Mol% in th...

  12. Experimental and life cycle assessment analysis of gas emission from mechanically-biologically pretreated waste in a landfill with energy recovery.

    PubMed

    Di Maria, Francesco; Sordi, Alessio; Micale, Caterina

    2013-11-01

    The global gaseous emissions produced by landfilling the Mechanically Sorted Organic Fraction (MSOF) with different weeks of Mechanical Biological Treatment (MBT) was evaluated for an existing waste management system. One MBT facility and a landfill with internal combustion engines fuelled by the landfill gas for electrical energy production operate in the waste management system considered. An experimental apparatus was used to simulate 0, 4, 8 and 16weeks of aerobic stabilization and the consequent biogas potential (Nl/kg) of a large sample of MSOF withdrawn from the full-scale MBT. Stabilization achieved by the waste was evaluated by dynamic oxygen uptake and fermentation tests. Good correlation coefficients (R(2)), ranging from 0.7668 to 0.9772, were found between oxygen uptake, fermentation and anaerobic test values. On the basis of the results of several anaerobic tests, the methane production rate k (year(-1)) was evaluated. k ranged from 0.436 to 0.308year(-1) and the bio-methane potential from 37 to 12Nm(3)/tonne, respectively, for the MSOF with 0 and 16weeks of treatment. Energy recovery from landfill gas ranged from about 11 to 90kWh per tonne of disposed MSOF depending on the different scenario investigated. Life cycle analysis showed that the scenario with 0weeks of pre-treatment has the highest weighted global impact even if opposite results were obtained with respect to the single impact criteria. MSOF pre-treatment periods longer than 4weeks showed rather negligible variation in the global impact of system emissions. PMID:23910244

  13. Evaluation of anaerobic co-digestion of dairy manure with food wastes via bio-methane potential assay and CSTR reactor.

    PubMed

    Ye, Yulin; Zamalloa, Carlos; Lin, Hongjian; Yan, Mi; Schmidt, David; Hu, Bo

    2015-01-01

    The introduction of food wastes into anaerobic digestion (AD) brings a promising scenario of increasing feedstock availability and overall energy production from AD. This study evaluated the biodegradability and methane potential from co-digestion of two typical food wastes, kitchen waste and chicken fat, with dairy manure. For single substrate, the bio-methane potential assays showed that kitchen waste had the highest methane yield of 352 L-CH4 kg(-1)-VS added, 92% more than dairy manure alone. Chicken fat at the same Volatile Solid (VS) level (2 g L(-1)) inhibited bio-methane production. Addition of kitchen waste and chicken fat to a VS percentage of up to 40% improved overall methane yield by 44% and 34%, respectively. Synergistic effect was observed when either combining two or three substrates as AD feedstock, possibly as a result of increased biodegradability of organic materials in chicken fat and kitchen waste compared with dairy manure. Addition of chicken fat improved methane yield more than kitchen waste. However, addition of chicken fat VS over 0.8 g L(-1) should be cautiously done because it may cause reactor failure due to decrease in pH. The maximum methane yield was 425 L-CH4 kg(-1)-VS, achieved at a VS ratio of 2:2:1 for kitchen waste, chicken fat, and dairy manure. Results from batch AD experiment demonstrated that supplementing dairy manure to chicken fat and/or kitchen waste improved alkalinity of substrate due to the inclusion of more titratable bases in dairy manure, and therefore stabilized the methanogenesis and substantially improved biogas yield. A mixture of substrates of kitchen waste, chicken fat, and dairy manure at a ratio of 1:1:3 was fed to a continuously stirred tank reactor operated at organic loading rates of 3.28, 6.55, and 2.18 g-COD L(-1)-day (hydraulic retention time of 20, 10, and 30 days, respectively) under mesophilic condition, and methane production rate reached 0.65, 0.95, and 0.34 L-CH4 L(-1)-reactor-day. PMID:25602155

  14. Safety Basis Report

    SciTech Connect

    R.J. Garrett

    2002-01-14

    As part of the internal Integrated Safety Management Assessment verification process, it was determined that there was a lack of documentation that summarizes the safety basis of the current Yucca Mountain Project (YMP) site characterization activities. It was noted that a safety basis would make it possible to establish a technically justifiable graded approach to the implementation of the requirements identified in the Standards/Requirements Identification Document. The Standards/Requirements Identification Documents commit a facility to compliance with specific requirements and, together with the hazard baseline documentation, provide a technical basis for ensuring that the public and workers are protected. This Safety Basis Report has been developed to establish and document the safety basis of the current site characterization activities, establish and document the hazard baseline, and provide the technical basis for identifying structures, systems, and components (SSCs) that perform functions necessary to protect the public, the worker, and the environment from hazards unique to the YMP site characterization activities. This technical basis for identifying SSCs serves as a grading process for the implementation of programs such as Conduct of Operations (DOE Order 5480.19) and the Suspect/Counterfeit Items Program. In addition, this report provides a consolidated summary of the hazards analyses processes developed to support the design, construction, and operation of the YMP site characterization facilities and, therefore, provides a tool for evaluating the safety impacts of changes to the design and operation of the YMP site characterization activities.

  15. Co-generation of biohydrogen and biomethane through two-stage batch co-fermentation of macro- and micro-algal biomass.

    PubMed

    Ding, Lingkan; Cheng, Jun; Xia, Ao; Jacob, Amita; Voelklein, Markus; Murphy, Jerry D

    2016-10-01

    Aquatic micro-algae can be used as feedstocks for gaseous biofuel production via biological fermentation. However, micro-algae usually have low C/N ratios, which are not advantageous for fermentation. In this study, carbon-rich macro-algae (Laminaria digitata) mixed with nitrogen-rich micro-algae (Chlorella pyrenoidosa and Nannochloropsis oceanica) were used to maintain a suitable C/N ratio of 20 for a two-stage process combining hydrogen and methane fermentation. Co-fermentation of L. digitata and micro-algae facilitated hydrolysis and acidogenesis, resulting in hydrogen yields of 94.5-97.0mL/gVS; these values were 15.5-18.5% higher than mono-fermentation using L. digitata. Through the second stage of methane co-fermentation, a large portion of energy remaining in the hydrogenogenic effluents was recovered in the form of biomethane. The two-stage batch co-fermentation markedly increased the energy conversion efficiencies (ECEs) from 4.6-6.6% during the hydrogen fermentation to 57.0-70.9% in the combined hydrogen and methane production. PMID:27371795

  16. Study on the bio-methane yield and microbial community structure in enzyme enhanced anaerobic co-digestion of cow manure and corn straw.

    PubMed

    Wang, Xuemei; Li, Zifu; Zhou, Xiaoqin; Wang, Qiqi; Wu, Yanga; Saino, Mayiani; Bai, Xue

    2016-11-01

    The use of enzymes to improve anaerobic co-digestion (AcoD) of cow manure and corn straw was explored in this study, including cellulase pretreatment and direct additions of amylase and protease. The effects of enzymes on microbial community structure were investigated though PCR-DGGE method. Results showed that AcoD with amylase achieved the highest methane yield of 377.63ml·CH4/g·VS, which was an increase of 110.79%. The methane increment consumed the amylase of 4.18×10(-5)g/ml·CH4. Enzymes mainly affected the bacteria in the hydrolysis stage rather than the bacteria in the hydrogenesis and acetogenesis stage and the archaea in the methanogenesis stage. However, the experimental results demonstrated that enzymes had no negative influence on microbial communities; the predominant microbial communities were similar. Therefore, AcoD with amylase was an effective way to improve the bio-methane yield of cow manure and corn straw. PMID:27484671

  17. Basis of Articulation.

    ERIC Educational Resources Information Center

    Kelz, Heinrich

    This article intends to shed light on the somewhat nebulous term "basis of articulation," which is used frequently in Eastern European phonetic and linguistic literature but highly neglected in contemporary American literature. In a historical approach, it is shown how the term originated and developed, how it is defined by various authors, and…

  18. Biomethanation of a mixture of salty cheese whey and poultry waste or cattle dung - a study of effect of temperature and retention time

    SciTech Connect

    Patel, C.; Madamwar, D.

    1996-08-01

    This paper describes the results of a study aimed at improving the efficiency of anaerobic digestion of salty cheese whey in combination with poultry waste or cattle dung. Best results were obtained when salty cheese whey was mixed with poultry waste in the ratio of 7:3, or cattle dung in the ratio of 1:1, both on dry weight basis giving maximum gas production of 1.2 L/L of digester/d with enriched methane content of 64% and 1.3 L/L of digester/d having methane content of 63% respectively. Various conditions such as temperature and retention time have been optimized for maximum process performance. 16 refs., 3 figs.

  19. Tegoprens in anaerobic digestion of a mixture of cheese whey, poultry waste, and cattle dung for improved biomethanation

    SciTech Connect

    Patel, C.; Sastry, V.; Madamwar, D.

    1996-01-01

    To obtain enriched methane content and improve the anaerobic digestion of a mixture of cattle dung, poultry waste, and cheese whey, the effect of various doses of Tegoprens: T-3012, T-3099, T-5842, T-5843, T-5851, T-5852 has been studied, in bench-scale digesters. Among them, Tegoprens 3022 showed more than a 45% increase in gas production with higher methane content. 18 refs., 1 fig.

  20. CONTINUOUS GAS ANALYZER

    DOEpatents

    Katz, S.; Weber, C.W.

    1960-02-16

    A reagent gas and a sample gas are chemically combined on a continuous basis in a reaction zone maintained at a selected temperature. The reagent gas and the sample gas are introduced to the reaction zone at preselected. constant molar rates of flow. The reagent gas and the selected gas in the sample mixture combine in the reaction zone to form a product gas having a different number of moles from the sum of the moles of the reactants. The difference in the total molar rates of flow into and out of the reaction zone is measured and indicated to determine the concentration of the selected gas.

  1. Anaerobic digestion of agricultural and other substrates--implications for greenhouse gas emissions.

    PubMed

    Pucker, J; Jungmeier, G; Siegl, S; Pötsch, E M

    2013-06-01

    The greenhouse gas (GHG) emissions, expressed in carbon dioxide equivalents (CO2-eq), of different Austrian biogas systems were analyzed and evaluated using life-cycle assessment (LCA) as part of a national project. Six commercial biogas plants were investigated and the analysis included the complete process chain: viz., the production and collection of substrates, the fermentation of the substrates in the biogas plant, the upgrading of biogas to biomethane (if applicable) and the use of the biogas or biomethane for heat and electricity or as transportation fuel. Furthermore, the LCA included the GHG emissions of construction, operation and dismantling of the major components involved in the process chain, as well as the use of by-products (e.g. fermentation residues used as fertilizers). All of the biogas systems reduced GHG emissions (in CO2-eq) compared with fossil reference systems. The potential for GHG reduction of the individual biogas systems varied between 60% and 100%. Type of feedstock and its reference use, agricultural practices, coverage of storage tanks for fermentation residues, methane leakage at the combined heat and power plant unit and the proportion of energy used as heat were identified as key factors influencing the GHG emissions of anaerobic digestion processes. PMID:23739470

  2. Opportunities for Switzerland to Contribute to the Production of Algal Biofuels: the Hydrothermal Pathway to Bio-Methane.

    PubMed

    Bagnoud-Velásquez, Mariluz; Refardt, Dominik; Vuille, François; Ludwig, Christian

    2015-01-01

    Microalgae have a significant potential to be a sustainable source of fuel and thus are of interest in the transition to a sustainable energy system, in particular for resource-dependent countries such as Switzerland. Independence of fossil fuels, considerable reduction of CO(2) emissions, and abandoning nuclear energy may be possible with an integrated system approach including the sourcing of biofuels from different types of biomass. Today, a full carbon-to-fuel conversion is possible, and has been recently demonstrated with an advanced hydrothermal technology. The potential to develop algal biofuels is viewed as high thanks to the possibility they offer to uncouple bioenergy from food production. Nevertheless, technological breakthroughs must take place before commercial production becomes a reality, especially to meet the necessary cost savings and efficiency gains in the algae cultivation structure. In addition, an integrated management of waste resources to promote the nutrient recovery appears today as imperative to further improve the economic viability and the environmental sustainability of algal production. We provide here a review that includes the global technological status of both algae production and their conversion into biofuels in order to understand first the added value of algal energy in general before we focus on the potential of algae to contribute specifically to the Swiss energy system to the horizon 2050. In this respect, the hydrothermal conversion pathway of microalgal biomass into synthetic natural gas (SNG) is emphasized, as research into this technology has received considerable attention in Switzerland during the last decade. In addition, SNG is a particularly relevant fuel in the Swiss context due to the existing gas grid and to the opportunity it offers to cover a wide spectrum of energy applications, in particular cogeneration of heat and electricity or use as a transport fuel in the growing gas car fleet. PMID:26598406

  3. Radioactive Waste Management Basis

    SciTech Connect

    Perkins, B K

    2009-06-03

    The purpose of this Radioactive Waste Management Basis is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE Manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

  4. WEST Physics Basis

    NASA Astrophysics Data System (ADS)

    Bourdelle, C.; Artaud, J. F.; Basiuk, V.; Bécoulet, M.; Brémond, S.; Bucalossi, J.; Bufferand, H.; Ciraolo, G.; Colas, L.; Corre, Y.; Courtois, X.; Decker, J.; Delpech, L.; Devynck, P.; Dif-Pradalier, G.; Doerner, R. P.; Douai, D.; Dumont, R.; Ekedahl, A.; Fedorczak, N.; Fenzi, C.; Firdaouss, M.; Garcia, J.; Ghendrih, P.; Gil, C.; Giruzzi, G.; Goniche, M.; Grisolia, C.; Grosman, A.; Guilhem, D.; Guirlet, R.; Gunn, J.; Hennequin, P.; Hillairet, J.; Hoang, T.; Imbeaux, F.; Ivanova-Stanik, I.; Joffrin, E.; Kallenbach, A.; Linke, J.; Loarer, T.; Lotte, P.; Maget, P.; Marandet, Y.; Mayoral, M. L.; Meyer, O.; Missirlian, M.; Mollard, P.; Monier-Garbet, P.; Moreau, P.; Nardon, E.; Pégourié, B.; Peysson, Y.; Sabot, R.; Saint-Laurent, F.; Schneider, M.; Travère, J. M.; Tsitrone, E.; Vartanian, S.; Vermare, L.; Yoshida, M.; Zagorski, R.; Contributors, JET

    2015-06-01

    With WEST (Tungsten Environment in Steady State Tokamak) (Bucalossi et al 2014 Fusion Eng. Des. 89 907-12), the Tore Supra facility and team expertise (Dumont et al 2014 Plasma Phys. Control. Fusion 56 075020) is used to pave the way towards ITER divertor procurement and operation. It consists in implementing a divertor configuration and installing ITER-like actively cooled tungsten monoblocks in the Tore Supra tokamak, taking full benefit of its unique long-pulse capability. WEST is a user facility platform, open to all ITER partners. This paper describes the physics basis of WEST: the estimated heat flux on the divertor target, the planned heating schemes, the expected behaviour of the L-H threshold and of the pedestal and the potential W sources. A series of operating scenarios has been modelled, showing that ITER-relevant heat fluxes on the divertor can be achieved in WEST long pulse H-mode plasmas.

  5. Genetic basis of hyperlysinemia

    PubMed Central

    2013-01-01

    Background Hyperlysinemia is an autosomal recessive inborn error of L-lysine degradation. To date only one causal mutation in the AASS gene encoding α-aminoadipic semialdehyde synthase has been reported. We aimed to better define the genetic basis of hyperlysinemia. Methods We collected the clinical, biochemical and molecular data in a cohort of 8 hyperlysinemia patients with distinct neurological features. Results We found novel causal mutations in AASS in all affected individuals, including 4 missense mutations, 2 deletions and 1 duplication. In two patients originating from one family, the hyperlysinemia was caused by a contiguous gene deletion syndrome affecting AASS and PTPRZ1. Conclusions Hyperlysinemia is caused by mutations in AASS. As hyperlysinemia is generally considered a benign metabolic variant, the more severe neurological disease course in two patients with a contiguous deletion syndrome may be explained by the additional loss of PTPRZ1. Our findings illustrate the importance of detailed biochemical and genetic studies in any hyperlysinemia patient. PMID:23570448

  6. Genetic basis of autoimmunity

    PubMed Central

    Marson, Alexander; Housley, William J.; Hafler, David A.

    2015-01-01

    Autoimmune diseases affect up to approximately 10% of the population. While rare Mendelian autoimmunity syndromes can result from monogenic mutations disrupting essential mechanisms of central and peripheral tolerance, more common human autoimmune diseases are complex disorders that arise from the interaction between polygenic risk factors and environmental factors. Although the risk attributable to most individual nucleotide variants is modest, genome-wide association studies (GWAS) have the potential to provide an unbiased view of biological pathways that drive human autoimmune diseases. Interpretation of GWAS requires integration of multiple genomic datasets including dense genotyping, cis-regulatory maps of primary immune cells, and genotyped studies of gene expression in relevant cell types and cellular conditions. Improved understanding of the genetic basis of autoimmunity may lead to a more sophisticated understanding of underlying cellular phenotypes and, eventually, novel diagnostics and targeted therapies. PMID:26030227

  7. Biomethanation of Syngas Using Anaerobic Sludge: Shift in the Catabolic Routes with the CO Partial Pressure Increase.

    PubMed

    Sancho Navarro, Silvia; Cimpoia, Ruxandra; Bruant, Guillaume; Guiot, Serge R

    2016-01-01

    Syngas generated by thermal gasification of biomass or coal can be steam reformed and purified into methane, which could be used locally for energy needs, or re-injected in the natural gas grid. As an alternative to chemical catalysis, the main components of the syngas (CO, CO2, and H2) can be used as substrates by a wide range of microorganisms, to be converted into gas biofuels, including methane. This study evaluates the carboxydotrophic (CO-consuming) methanogenic potential present in an anaerobic sludge from an upflow anaerobic sludge bed (UASB) reactor treating waste water, and elucidates the CO conversion routes to methane at 35 ± 3°C. Kinetic activity tests under CO at partial pressures (pCO) varying from 0.1 to 1.5 atm (0.09-1.31 mmol/L in the liquid phase) showed a significant carboxydotrophic activity potential for growing conditions on CO alone. A maximum methanogenic activity of 1 mmol CH4 per g of volatile suspended solid and per day was achieved at 0.2 atm of CO (0.17 mmol/L), and then the rate decreased with the amount of CO supplied. The intermediary metabolites such as acetate, H2, and propionate started to accumulate at higher CO concentrations. Inhibition experiments with 2-bromoethanesulfonic acid (BES), fluoroacetate, and vancomycin showed that in a mixed culture CO was converted mainly to acetate by acetogenic bacteria, which was further transformed to methane by acetoclastic methanogens, while direct methanogenic CO conversion was negligible. Methanogenesis was totally blocked at high pCO in the bottles (≥1 atm). However it was possible to achieve higher methanogenic potential under a 100% CO atmosphere after acclimation of the sludge to CO. This adaptation to high CO concentrations led to a shift in the archaeal population, then dominated by hydrogen-utilizing methanogens, which were able to take over acetoclastic methanogens, while syntrophic acetate oxidizing (SAO) bacteria oxidized acetate into CO2 and H2. The disaggregation of the

  8. Biomethanation of Syngas Using Anaerobic Sludge: Shift in the Catabolic Routes with the CO Partial Pressure Increase

    PubMed Central

    Sancho Navarro, Silvia; Cimpoia, Ruxandra; Bruant, Guillaume; Guiot, Serge R.

    2016-01-01

    Syngas generated by thermal gasification of biomass or coal can be steam reformed and purified into methane, which could be used locally for energy needs, or re-injected in the natural gas grid. As an alternative to chemical catalysis, the main components of the syngas (CO, CO2, and H2) can be used as substrates by a wide range of microorganisms, to be converted into gas biofuels, including methane. This study evaluates the carboxydotrophic (CO-consuming) methanogenic potential present in an anaerobic sludge from an upflow anaerobic sludge bed (UASB) reactor treating waste water, and elucidates the CO conversion routes to methane at 35 ± 3°C. Kinetic activity tests under CO at partial pressures (pCO) varying from 0.1 to 1.5 atm (0.09–1.31 mmol/L in the liquid phase) showed a significant carboxydotrophic activity potential for growing conditions on CO alone. A maximum methanogenic activity of 1 mmol CH4 per g of volatile suspended solid and per day was achieved at 0.2 atm of CO (0.17 mmol/L), and then the rate decreased with the amount of CO supplied. The intermediary metabolites such as acetate, H2, and propionate started to accumulate at higher CO concentrations. Inhibition experiments with 2-bromoethanesulfonic acid (BES), fluoroacetate, and vancomycin showed that in a mixed culture CO was converted mainly to acetate by acetogenic bacteria, which was further transformed to methane by acetoclastic methanogens, while direct methanogenic CO conversion was negligible. Methanogenesis was totally blocked at high pCO in the bottles (≥1 atm). However it was possible to achieve higher methanogenic potential under a 100% CO atmosphere after acclimation of the sludge to CO. This adaptation to high CO concentrations led to a shift in the archaeal population, then dominated by hydrogen-utilizing methanogens, which were able to take over acetoclastic methanogens, while syntrophic acetate oxidizing (SAO) bacteria oxidized acetate into CO2 and H2. The disaggregation of the

  9. HTGR Fuel performance basis

    SciTech Connect

    Shamasundar, B.I.; Stansfield, O.M.; Jensen, D.D.

    1982-05-01

    The safety characteristics of the high-temperature gas-cooled reactor (HTGR) during normal and accident conditions are determined in part by HTGR fuel performance. During normal operation, less than 0.1% fuel failure occurs, primarily from defective particles. This low fuel failure fraction limits circulating activity to acceptable levels. During severe accidents, the radiological consequence is influenced by high-temperature fuel particle behavior. An empirical fuel failure model, supported by recent experimental data, is presented. The onset of significant fuel particle failure occurs at temperatures in excess of 1600/sup 0/C, and complete fuel failure occurs at 2660/sup 0/C. This indicates that the fuel is more retentive at higher temperatures than previously assumed. The more retentive nature of the fuel coupled with the high thermal capacitance of the core results in slow release of fission products from the core during severe accidents.

  10. Estimated CO2, SO2 and H2S emission to the atmosphere from the 2011 El Hierro submarine eruption (Canary Islands) on the basis of helicopter gas surveys

    NASA Astrophysics Data System (ADS)

    Barrancos, J.; Padilla, G.; Padrón, E.; Hernández, P. A.; Calvo, D.; Marquez, A.; Pérez, N. M.; Melian, G.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Hernández, I.

    2012-04-01

    An accurate estimation of SO2 emission rates is an important issue to elucidate the activity of volcanoes, moreover the monitoring of its temporal evolution might help to predict a possible eruption and thus, save the loss of human's lives in cities nearby volcanoes. In the lasts years new instruments have been developed and improved, in order to be more portable, cheaper and lighter. The miniDOAS consist of a small spectrometer with a lens for collecting scattered UV light, and are controlled/powered via USB with a laptop. Recently, new technical developments have allowed monitoring the emission of other gas species such as CO2, H2S, etc from volcanic plumes by means of portable multisensor system. With both devices we were able to evaluate the SO2 emission rates and the molar ratios of major volcanic gas components, respectively. Multiplying the observed SO2 emission rate times the observed (gas)i/SO2 mass ratios (CO2/SO2 and H2S/SO2) allowed us to estimate other volatiles emission rates. Between November 11, 2011, and January 16, 2012, and as a consequence of the submarine volcanic eruption started on October 10, 2011, south off shore El Hierro, Canary Islands, a regularly monitoring of the volcanic plume from the submarine volcano has been performed with remote sensors, always depending of helicopter availability. The instruments are mounted aboard on a helicopter belonged to the Helicopter Unit of Spanish Civil Guard. The SO2 flux measured during this period showed a maximum SO2 emission of 109 ± 19 t/d on November 6, just two days before the occurrence of a intense bubbling at the sea surface on November 8, producing a water, gas and ash column of about 15 meters over the sea surface. That day, CO2 and H2S emission also reached the maximum measured, with 5400 t/d and 3.6 t/d, respectively. Since then, SO2, CO2 and H2S emission rates have declined to values close to detection limit (~ 2 t/d for SO2). These results report the first SO2 emission rates measured

  11. Basis Selection for Wavelet Regression

    NASA Technical Reports Server (NTRS)

    Wheeler, Kevin R.; Lau, Sonie (Technical Monitor)

    1998-01-01

    A wavelet basis selection procedure is presented for wavelet regression. Both the basis and the threshold are selected using cross-validation. The method includes the capability of incorporating prior knowledge on the smoothness (or shape of the basis functions) into the basis selection procedure. The results of the method are demonstrated on sampled functions widely used in the wavelet regression literature. The results of the method are contrasted with other published methods.

  12. Production of Renewable Natural Gas from Waste Biomass

    NASA Astrophysics Data System (ADS)

    Kumar, Sachin; Suresh, S.; Arisutha, S.

    2013-03-01

    Biomass energy is expected to make a major contribution to the replacement of fossil fuels. Methane produced from biomass is referred to as bio-methane, green gas, bio-substitute natural gas or renewable natural gas (RNG) when it is used as a transport fuel. Research on upgrading of the cleaned producer gas to RNG is still ongoing. The present study deals with the conversion of woody biomass into fuels, RNG using gasifier. The various effects of parameters like temperature, pressure, and tar formation on conversion were also studied. The complete carbon conversion was observed at 480 °C and tar yield was significantly less. When biomass was gasified with and without catalyst at about 28 s residence time, ~75 % (w/w) and 88 % (w/w) carbon conversion for without and with catalyst was observed. The interest in RNG is growing; several initiatives to demonstrate the thermal-chemical conversion of biomass into methane and/or RNG are under development.

  13. Geographic patterns of carbon dioxide emissions from fossil-fuel burning, hydraulic cement production, and gas flaring on a one degree by one degree grid cell basis: 1950 to 1990

    SciTech Connect

    Brenkert, A.L.; Andres, R.J.; Marland, G.; Fung, I. |; Matthews, E. |

    1997-03-01

    Data sets of one degree latitude by one degree longitude carbon dioxide (CO{sub 2}) emissions in units of thousand metric tons of carbon (C) per year from anthropogenic sources have been produced for 1950, 1960, 1970, 1980 and 1990. Detailed geographic information on CO{sub 2} emissions can be critical in understanding the pattern of the atmospheric and biospheric response to these emissions. Global, regional and national annual estimates for 1950 through 1992 were published previously. Those national, annual CO{sub 2} emission estimates were based on statistics on fossil-fuel burning, cement manufacturing and gas flaring in oil fields as well as energy production, consumption and trade data, using the methods of Marland and Rotty. The national annual estimates were combined with gridded one-degree data on political units and 1984 human populations to create the new gridded CO{sub 2} emission data sets. The same population distribution was used for each of the years as proxy for the emission distribution within each country. The implied assumption for that procedure was that per capita energy use and fuel mix is uniform over a political unit. The consequence of this first-order procedure is that the spatial changes observed over time are solely due to changes in national energy consumption and nation-based fuel mix. Increases in emissions over time are apparent for most areas.

  14. Determination of organic priority pollutants and emerging compounds in wastewater and snow samples using multiresidue protocols on the basis of microextraction by packed sorbents coupled to large volume injection gas chromatography-mass spectrometry analysis.

    PubMed

    Prieto, A; Schrader, S; Moeder, M

    2010-09-17

    This paper describes the development and validation of a new procedure for the simultaneous determination of 41 multi-class priority and emerging organic pollutants in water samples using microextraction by packed sorbent (MEPS) followed by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). Apart from method parameter optimization the influence of humic acids as matrix components on the extraction efficiency of MEPS procedure was also evaluated. The list of target compounds includes polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), phthalate esters (PEs), nonylphenols (NPs), bisphenol A (BPA) and selected steroid hormones. The performance of the new at-line microextraction-LVI-GC-MS protocol was compared to standard solid-phase extraction (SPE) and LVI-GC-MS analysis. LODs for 100 mL samples (SPE) ranged from 0.2 to 736 ng L(-1) were obtained. LODs for 800 microL of sample (MEPS) were between 0.2 and 266 ng L(-1). In the case of MEPS methodology even a sample volume of only 800 microL allowed to detect the target compounds. These results demonstrate the high sensitivity of both procedures which permitted to obtain good recoveries (>75%) for all cases. The precision of the methods, calculated as relative standard deviation (RSD) was below 21% for all compounds and both methodologies. Finally, the developed methods were applied to the determination of target analytes in various samples, including snow and wastewater. PMID:20719318

  15. 26 CFR 1.705-1 - Determination of basis of partner's interest.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... for depletion allowable under section 611 for any partnership oil and gas property to the extent the..., and (iii) The excess of the deductions for depletion over the basis of the depletable property, unless the property is an oil or gas property the basis of which has been allocated to partners under...

  16. 26 CFR 1.705-1 - Determination of basis of partner's interest.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... for depletion allowable under section 611 for any partnership oil and gas property to the extent the..., and (iii) The excess of the deductions for depletion over the basis of the depletable property, unless the property is an oil or gas property the basis of which has been allocated to partners under...

  17. 26 CFR 1.705-1 - Determination of basis of partner's interest.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... for depletion allowable under section 611 for any partnership oil and gas property to the extent the..., and (iii) The excess of the deductions for depletion over the basis of the depletable property, unless the property is an oil or gas property the basis of which has been allocated to partners under...

  18. Recirculating rotary gas compressor

    DOEpatents

    Weinbrecht, John F.

    1992-01-01

    A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

  19. Recirculating rotary gas compressor

    DOEpatents

    Weinbrecht, J.F.

    1992-02-25

    A positive displacement, recirculating Roots-type rotary gas compressor is described which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits which return compressed discharge gas to the compressor housing, where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor. 12 figs.

  20. Noble gas fractionation during subsurface gas migration

    NASA Astrophysics Data System (ADS)

    Sathaye, Kiran J.; Larson, Toti E.; Hesse, Marc A.

    2016-09-01

    Environmental monitoring of shale gas production and geological carbon dioxide (CO2) storage requires identification of subsurface gas sources. Noble gases provide a powerful tool to distinguish different sources if the modifications of the gas composition during transport can be accounted for. Despite the recognition of compositional changes due to gas migration in the subsurface, the interpretation of geochemical data relies largely on zero-dimensional mixing and fractionation models. Here we present two-phase flow column experiments that demonstrate these changes. Water containing a dissolved noble gas is displaced by gas comprised of CO2 and argon. We observe a characteristic pattern of initial co-enrichment of noble gases from both phases in banks at the gas front, followed by a depletion of the dissolved noble gas. The enrichment of the co-injected noble gas is due to the dissolution of the more soluble major gas component, while the enrichment of the dissolved noble gas is due to stripping from the groundwater. These processes amount to chromatographic separations that occur during two-phase flow and can be predicted by the theory of gas injection. This theory provides a mechanistic basis for noble gas fractionation during gas migration and improves our ability to identify subsurface gas sources after post-genetic modification. Finally, we show that compositional changes due to two-phase flow can qualitatively explain the spatial compositional trends observed within the Bravo Dome natural CO2 reservoir and some regional compositional trends observed in drinking water wells overlying the Marcellus and Barnett shale regions. In both cases, only the migration of a gas with constant source composition is required, rather than multi-stage mixing and fractionation models previously proposed.

  1. 26 CFR 1.612-1 - Basis for allowance of cost depletion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... included in the basis for cost depletion of oil and gas property the amounts of capitalized drilling and... 26 Internal Revenue 7 2013-04-01 2013-04-01 false Basis for allowance of cost depletion. 1.612-1... depletion. (a) In general. The basis upon which the deduction for cost depletion under section 611 is to...

  2. 26 CFR 1.612-1 - Basis for allowance of cost depletion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... included in the basis for cost depletion of oil and gas property the amounts of capitalized drilling and... 26 Internal Revenue 7 2014-04-01 2013-04-01 true Basis for allowance of cost depletion. 1.612-1... depletion. (a) In general. The basis upon which the deduction for cost depletion under section 611 is to...

  3. 26 CFR 1.612-1 - Basis for allowance of cost depletion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... included in the basis for cost depletion of oil and gas property the amounts of capitalized drilling and... 26 Internal Revenue 7 2012-04-01 2012-04-01 false Basis for allowance of cost depletion. 1.612-1... depletion. (a) In general. The basis upon which the deduction for cost depletion under section 611 is to...

  4. The Basis Code Development System

    Energy Science and Technology Software Center (ESTSC)

    1994-03-15

    BASIS9.4 is a system for developing interactive computer programs in Fortran, with some support for C and C++ as well. Using BASIS9.4 you can create a program that has a sophisticated programming language as its user interface so that the user can set, calculate with, and plot, all the major variables in the program. The program author writes only the scientific part of the program; BASIS9.4 supplies an environment in which to exercise that scientificmore » programming which includes an interactive language, an interpreter, graphics, terminal logs, error recovery, macros, saving and retrieving variables, formatted I/O, and online documentation.« less

  5. B Plant interim safety basis

    SciTech Connect

    Chalk, S.E.

    1996-09-01

    This interim safety basis (ISB-008) replaces the B Plant Safety Analysis Report, WHC-SD-WM-SAR-013, Rev. 2 (WHC 1993a). ISB-008 uses existing accident analyses, modified existing accident analyses, and new accident analyses to prove that B Plant remains within the safety envelope for transition, deactivation, standby, and shutdown activities. The analyses in ISB-008 are in accordance with the most current requirements for analytical approach, risk determination, and configuration management. This document and supporting accident analyses replace previous design-basis documents.

  6. Enhanced anaerobic digestion of food waste by thermal and ozonation pretreatment methods.

    PubMed

    Ariunbaatar, Javkhlan; Panico, Antonio; Frunzo, Luigi; Esposito, Giovanni; Lens, Piet N L; Pirozzi, Francesco

    2014-12-15

    Treatment of food waste by anaerobic digestion can lead to an energy production coupled to a reduction of the volume and greenhouse gas emissions from this waste type. According to EU Regulation EC1774/2002, food waste should be pasteurized/sterilized before or after anaerobic digestion. With respect to this regulation and also considering the slow kinetics of the anaerobic digestion process, thermal and chemical pretreatments of food waste prior to mesophilic anaerobic digestion were studied. A series of batch experiments to determine the biomethane potential of untreated as well as pretreated food waste was carried out. All tested conditions of both thermal and ozonation pretreatments resulted in an enhanced biomethane production. The kinetics of the anaerobic digestion process were, however, accelerated by thermal pretreatment at lower temperatures (<120 °C) only. The best result of 647.5 ± 10.6 mlCH4/gVS, which is approximately 52% higher as compared to the specific biomethane production of untreated food waste, was obtained with thermal pretreatment at 80 °C for 1.5 h. On the basis of net energy calculations, the enhanced biomethane production could cover the energy requirement of the thermal pretreatment. In contrast, the enhanced biomethane production with ozonation pretreatment is insufficient to supply the required energy for the ozonator. PMID:25169646

  7. GASB's Basis of Accounting Project.

    ERIC Educational Resources Information Center

    Kovlak, Daniel L.

    1986-01-01

    In July 1984, the Governmental Accounting Standards Board began its "Measurement Focus/Basis of Accounting" project, which addresses measurement issues and revenue and expenditure recognition problems involving governmental funds. This article explains the project's background, alternatives discussed by the board, and tentative conclusions and…

  8. A Molecular Basis of Cancer.

    ERIC Educational Resources Information Center

    Weinberg, Robert A.

    1983-01-01

    Discusses the molecular basis of cancer, focusing on genetics of the disease. Indicates that human cancers are initiated by oncogenes (altered versions of normal genes) and that in one case the critical alteration is a single point mutation that changes one amino acid in the protein encoded by the gene. (JN)

  9. Grobner Basis Representations of Sudoku

    ERIC Educational Resources Information Center

    Taalman, Laura; Arnold, Elizabeth; Lucas, Stephen

    2010-01-01

    This paper uses Grobner bases to explore the inherent structure of Sudoku puzzles and boards. In particular, we develop three different ways of representing the constraints of Sudoku puzzles with a system of polynomial equations. In one case, we explicitly show how a Grobner basis can be used to obtain a more meaningful representation of the…

  10. Detection of Gaseous Plumes using Basis Vectors

    SciTech Connect

    Chilton, Lawrence; Walsh, Stephen

    2009-05-01

    Detecting and identifying weak gaseous plumes using thermal imaging data is complicated by many factors. There are several methods currently being used to detect plumes. They can be grouped into two categories: those that use a chemical spectral library and those that don’t. The approaches that use chemical libraries include least squares methods and physics-based approaches. They are "optimal" only if the plume chemical is actually in the search set but risk missing chemicals not in the library. The methods that don’t use a chemical spectral library are based on a statistical or data analytical transformation applied to the data. These include principle components, independent components, entropy, Fourier transform, and others. These methods do not explicitly take advantage of the physics of the signal formulation process and therefore don’t exploit all available information in the data. This paper presents initial results of employing basis vectors as a tool for plume detection. It describes the standard generalized least squares approach using gas spectra, presents the detection approach using basis vectors, and compares detection images resulting from applying both methods to synthetic hyperspectral images.

  11. Authorization basis requirements comparison report

    SciTech Connect

    Brantley, W.M.

    1997-08-18

    The TWRS Authorization Basis (AB) consists of a set of documents identified by TWRS management with the concurrence of DOE-RL. Upon implementation of the TWRS Basis for Interim Operation (BIO) and Technical Safety Requirements (TSRs), the AB list will be revised to include the BIO and TSRs. Some documents that currently form part of the AB will be removed from the list. This SD identifies each - requirement from those documents, and recommends a disposition for each to ensure that necessary requirements are retained when the AB is revised to incorporate the BIO and TSRs. This SD also identifies documents that will remain part of the AB after the BIO and TSRs are implemented. This document does not change the AB, but provides guidance for the preparation of change documentation.

  12. Perceptual basis for reactive teleoperation.

    SciTech Connect

    Park, Y. S.; Ewing, T. F.; Boyle, J. M.; Yule, T. J.

    2001-08-28

    To enhance task performance in partially structured environment, enhancement of teleoperation was proposed by introducing autonomous behaviors. Such autonomy is implemented based on reactive robotic architecture, where reactive motor agents that directly couples sensory inputs and motor actions become the building blocks. To this end, presented in this paper is a perceptual basis for the motor agents. The perceptual basis consists of perceptual agents that extracts environmental information from a structured light vision system and provide action oriented perception for the corresponding motor agents. Rather than performing general scene reconstruction, a perceptual agent directly provides the motion reference for the motor behavior. Various sensory mechanisms--sensor fission, fusion, and fashion--becomes basic building blocks of the perception process. Since perception is a process deeply intertwined with the motor actions, active perception may also incorporate motor behaviors as an integral perceptual process.

  13. Hanford Generic Interim Safety Basis

    SciTech Connect

    Lavender, J.C.

    1994-09-09

    The purpose of this document is to identify WHC programs and requirements that are an integral part of the authorization basis for nuclear facilities that are generic to all WHC-managed facilities. The purpose of these programs is to implement the DOE Orders, as WHC becomes contractually obligated to implement them. The Hanford Generic ISB focuses on the institutional controls and safety requirements identified in DOE Order 5480.23, Nuclear Safety Analysis Reports.

  14. Performance Basis for Airborne Separation

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    2008-01-01

    Emerging applications of Airborne Separation Assistance System (ASAS) technologies make possible new and powerful methods in Air Traffic Management (ATM) that may significantly improve the system-level performance of operations in the future ATM system. These applications typically involve the aircraft managing certain components of its Four Dimensional (4D) trajectory within the degrees of freedom defined by a set of operational constraints negotiated with the Air Navigation Service Provider. It is hypothesized that reliable individual performance by many aircraft will translate into higher total system-level performance. To actually realize this improvement, the new capabilities must be attracted to high demand and complexity regions where high ATM performance is critical. Operational approval for use in such environments will require participating aircraft to be certified to rigorous and appropriate performance standards. Currently, no formal basis exists for defining these standards. This paper provides a context for defining the performance basis for 4D-ASAS operations. The trajectory constraints to be met by the aircraft are defined, categorized, and assessed for performance requirements. A proposed extension of the existing Required Navigation Performance (RNP) construct into a dynamic standard (Dynamic RNP) is outlined. Sample data is presented from an ongoing high-fidelity batch simulation series that is characterizing the performance of an advanced 4D-ASAS application. Data of this type will contribute to the evaluation and validation of the proposed performance basis.

  15. Retained gas inventory comparison

    SciTech Connect

    BARTON, W.B.

    1999-05-18

    Gas volume data derived from four different analytical methods were collected and analyzed for comparison to volumes originally used in the technical basis for the Basis for Interim Operations (BIO). The original volumes came from Hodgson (1996) listed in the reference section of this document. Hodgson (1996) screened all 177 single and double-shell tanks for the presence of trapped gas in waste via two analytical methods: Surface Level Rise (SLR), and Barometric Pressure Effect (BPE). More recent gas volume projections have been calculated using different analytical techniques along with updates to the parameters used as input to the SLR and BPE models. Gas volumes derived from new analytical instruments include those as measured by the Void Fraction Instrument (VFI) and Retained Gas Sampler (RGS). The results of this comparison demonstrate that the original retained gas volumes of Hodgson (1996) used as a technical basis in developing the BIO were conservative, and were conservative from a safety analysis standpoint. These results represent only comparisons to the original reported volumes using the limited set of newly acquired data that is available.

  16. The Basis version of LASNEX

    NASA Astrophysics Data System (ADS)

    Dubois, P. F.

    1990-10-01

    We have made major changes to the computer science aspects of our laser fusion simulation program LASNEX. LASNEX is now using the Basis system, a FORTRAN development system developed over the last six years at Lawrence Livermore National Laboratory. This has given users greatly increased power and flexibility. We have eliminated all non-standard usage and macros, enabling us to begin the port of LASNEX to workstations. At the same time, we have completely redone the system used to maintain the source and create new versions of LASNEX, resulting in major gains in capability and productivity.

  17. The Basis version of LASNEX

    SciTech Connect

    Dubois, P.F.

    1990-10-26

    We have made major changes to the computer science aspects of our laser fusion simulation program LASNEX. LASNEX is now using the Basis system, a Fortran development system developed over the last six years at Lawrence Livermore National Laboratory. This has given users greatly increased power and flexibility. We have eliminated all non-standard usage and macros, enabling us to begin the port of LASNEX to workstations. At the same time, we have completely redone the system used to maintain the source and create new versions of LASNEX, resulting in major gains in capability and productivity. 5 refs.

  18. Value basis for conservation policy

    SciTech Connect

    Leiss, W.

    1981-01-01

    This paper is a case study in attempting to apply a particular value (caring) to the domain of social policy, specifically resource conservation policy. The argument is that our consumer society erodes the social basis for the development by individuals of a sense of well-being and personal identity, and that a conservation ethic based on the concept of caring could provide a foundation in practical morality and public policy for a viable sense of well-being. Conservation, then, goes beyond eliminating wasteful consumption to encompass a public commitment that can further economic and social goals. 11 references.

  19. Nitrogen cycle: Basis of life; Stickstoffkreislaeufe: basis des lebens

    SciTech Connect

    Haunold, E.

    1992-10-01

    About 200 species of bacteria and blue algae yearly fix 175 Mio t of nitrogen from the air. This input of nitrogen into the compartment land - sea occurs by means of the enzyme nitrogenase. Within this process of biological nitrogen fixation (BNF) elemental nitrogen is transformed to bound organic nitrogen. All other living organisms depend on bound nitrogen. BNF is nowadays strongly supported by the technical nitrogen fixation (TNF) according to the Haber-Bosch-process. The technically fixed fertilizer nitrogen will soon reach 100 Mio t/a. With the rain additionally 200 Mio t of N/a are washed in as NH3, NH4 or NOx. The inputs are balanced by the outputs of the same magnitude, which occur as the result of mineralization of organic matter, ammonia volatilization and denitrification. The nitrogen cycles thus constitute the basis for life.

  20. PARFUME Theory and Model basis Report

    SciTech Connect

    Darrell L. Knudson; Gregory K Miller; G.K. Miller; D.A. Petti; J.T. Maki; D.L. Knudson

    2009-09-01

    The success of gas reactors depends upon the safety and quality of the coated particle fuel. The fuel performance modeling code PARFUME simulates the mechanical, thermal and physico-chemical behavior of fuel particles during irradiation. This report documents the theory and material properties behind vari¬ous capabilities of the code, which include: 1) various options for calculating CO production and fission product gas release, 2) an analytical solution for stresses in the coating layers that accounts for irradiation-induced creep and swelling of the pyrocarbon layers, 3) a thermal model that calculates a time-dependent temperature profile through a pebble bed sphere or a prismatic block core, as well as through the layers of each analyzed particle, 4) simulation of multi-dimensional particle behavior associated with cracking in the IPyC layer, partial debonding of the IPyC from the SiC, particle asphericity, and kernel migration (or amoeba effect), 5) two independent methods for determining particle failure probabilities, 6) a model for calculating release-to-birth (R/B) ratios of gaseous fission products that accounts for particle failures and uranium contamination in the fuel matrix, and 7) the evaluation of an accident condition, where a particle experiences a sudden change in temperature following a period of normal irradiation. The accident condi¬tion entails diffusion of fission products through the particle coating layers and through the fuel matrix to the coolant boundary. This document represents the initial version of the PARFUME Theory and Model Basis Report. More detailed descriptions will be provided in future revisions.

  1. The Gas Laws

    ERIC Educational Resources Information Center

    Raman, V. V.

    1973-01-01

    Inquires into the individual names and dates which are associated with the various perfect gas laws on the basis of published and historically researched works. Indicates the presence of eight features in giving a scientist credit for a scientific discovery. (CC)

  2. 10 CFR 830.202 - Safety basis.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Safety basis. 830.202 Section 830.202 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.202 Safety basis. (a) The contractor... in the safety basis any changes, conditions, or hazard controls directed by DOE....

  3. 10 CFR 830.202 - Safety basis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Safety basis. 830.202 Section 830.202 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.202 Safety basis. (a) The contractor... in the safety basis any changes, conditions, or hazard controls directed by DOE....

  4. 10 CFR 830.202 - Safety basis.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Safety basis. 830.202 Section 830.202 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.202 Safety basis. (a) The contractor... in the safety basis any changes, conditions, or hazard controls directed by DOE....

  5. 10 CFR 830.202 - Safety basis.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Safety basis. 830.202 Section 830.202 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.202 Safety basis. (a) The contractor... in the safety basis any changes, conditions, or hazard controls directed by DOE....

  6. Cryoresistive gas insulated line

    NASA Astrophysics Data System (ADS)

    Hidaka, K.; Matsumoto, S.; Kouno, T.

    An insulation strength of more than 16 kV mm -1 has been realized using nitrogen gas at 133 K and 0.4 MPa with the application of a.c. and impulse voltages. A cryoresistive gas insulated line (CRGIL) using nitrogen gas is proposed on the basis of the measured insulation strength. An efficient method for use of the cooling heat of liquefied natural gas is also proposed so that no refrigerator is required and the cost of cooling is reduced. The CRGIL has the advantages of having a large current carrying capacity, small power loss and small capacitance. Moreover, a given transmission capacity is achieved by a CRGIL whose rated voltage is about half that in a conventional gas insulated line.

  7. Internal dosimetry technical basis manual

    SciTech Connect

    Not Available

    1990-12-20

    The internal dosimetry program at the Savannah River Site (SRS) consists of radiation protection programs and activities used to detect and evaluate intakes of radioactive material by radiation workers. Examples of such programs are: air monitoring; surface contamination monitoring; personal contamination surveys; radiobioassay; and dose assessment. The objectives of the internal dosimetry program are to demonstrate that the workplace is under control and that workers are not being exposed to radioactive material, and to detect and assess inadvertent intakes in the workplace. The Savannah River Site Internal Dosimetry Technical Basis Manual (TBM) is intended to provide a technical and philosophical discussion of the radiobioassay and dose assessment aspects of the internal dosimetry program. Detailed information on air, surface, and personal contamination surveillance programs is not given in this manual except for how these programs interface with routine and special bioassay programs.

  8. The Chemical Basis of Pharmacology

    PubMed Central

    2010-01-01

    Molecular biology now dominates pharmacology so thoroughly that it is difficult to recall that only a generation ago the field was very different. To understand drug action today, we characterize the targets through which they act and new drug leads are discovered on the basis of target structure and function. Until the mid-1980s the information often flowed in reverse: investigators began with organic molecules and sought targets, relating receptors not by sequence or structure but by their ligands. Recently, investigators have returned to this chemical view of biology, bringing to it systematic and quantitative methods of relating targets by their ligands. This has allowed the discovery of new targets for established drugs, suggested the bases for their side effects, and predicted the molecular targets underlying phenotypic screens. The bases for these new methods, some of their successes and liabilities, and new opportunities for their use are described. PMID:21058655

  9. Chemical basis for minimal cognition.

    PubMed

    Hanczyc, Martin M; Ikegami, Takashi

    2010-01-01

    We have developed a simple chemical system capable of self-movement in order to study the physicochemical origins of movement. We propose how this system may be useful in the study of minimal perception and cognition. The system consists simply of an oil droplet in an aqueous environment. A chemical reaction within the oil droplet induces an instability, the symmetry of the oil droplet breaks, and the droplet begins to move through the aqueous phase. The complement of physical phenomena that is then generated indicates the presence of feedback cycles that, as will be argued, form the basis for self-regulation, homeostasis, and perhaps an extended form of autopoiesis. We discuss the result that simple chemical systems are capable of sensory-motor coupling and possess a homeodynamic state from which cognitive processes may emerge. PMID:20586578

  10. The scientific basis of flotation

    SciTech Connect

    Ives, K.J.

    1984-01-01

    The practical art of flotation, used for about 100 years in mineral processing, has an underlying science. This book describes this scientific basis, by commencing with the surface properties of fine particles in water, and the physical and hydrodynamic behaviour of bubbles. The book integrates the physical, chemical, hydrodynamic and process engineering aspects of flotation, which is not found in existing publications. The contents include: introduction; the froth flotation process; past, present and future-in brief; physics and hydrodynamics of bubbles; thin films, contact angles, wetting. Some aspects of the physical chemistry of solid/water interfaces; experimental techniques in flotation; flotation in mineral processing; engineering aspects of flotation in the minerals industry; flotation machines, circuits and their simulation; and flotation in water treatment. wastewater treatment.

  11. The neurological basis of occupation.

    PubMed

    Gutman, Sharon A; Schindler, Victoria P

    2007-01-01

    The purpose of the present paper was to survey the literature about the neurological basis of human activity and its relationship to occupation and health. Activities related to neurological function were organized into three categories: those that activate the brain's reward system; those that promote the relaxation response; and those that preserve cognitive function into old age. The results from the literature review correlating neurological evidence and activities showed that purposeful and meaningful activities could counter the effects of stress-related diseases and reduce the risk for dementia. Specifically, it was found that music, drawing, meditation, reading, arts and crafts, and home repairs, for example, can stimulate the neurogical system and enhance health and well-being, Prospective research studies are needed to examine the effects of purposeful activities on reducing stress and slowing the rate of cognitive decline. PMID:17623380

  12. The Genetic Basis of Hydrocephalus.

    PubMed

    Kousi, Maria; Katsanis, Nicholas

    2016-07-01

    Studies of syndromic hydrocephalus have led to the identification of >100 causative genes. Even though this work has illuminated numerous pathways associated with hydrocephalus, it has also highlighted the fact that the genetics underlying this phenotype are more complex than anticipated originally. Mendelian forms of hydrocephalus account for a small fraction of the genetic burden, with clear evidence of background-dependent effects of alleles on penetrance and expressivity of driver mutations in key developmental and homeostatic pathways. Here, we synthesize the currently implicated genes and inheritance paradigms underlying hydrocephalus, grouping causal loci into functional modules that affect discrete, albeit partially overlapping, cellular processes. These in turn have the potential to both inform pathomechanism and assist in the rational molecular classification of a clinically heterogeneous phenotype. Finally, we discuss conceptual methods that can lead to enhanced gene identification and dissection of disease basis, knowledge that will potentially form a foundation for the design of future therapeutics. PMID:27145913

  13. Detection of Gaseous Plumes using Basis Vectors.

    PubMed

    Chilton, Lawrence; Walsh, Stephen

    2009-01-01

    Detecting and identifying weak gaseous plumes using thermal imaging data is complicated by many factors. There are several methods currently being used to detect plumes. They can be grouped into two categories: those that use a chemical spectral library and those that don't. The approaches that use chemical libraries include physics-based least squares methods (matched filter). They are "optimal" only if the plume chemical is actually in the search library but risk missing chemicals not in the library. The methods that don't use a chemical spectral library are based on a statistical or data analytical transformation applied to the data. These include principle components, independent components, entropy, Fourier transform, and others. These methods do not explicitly take advantage of the physics of the signal formulation process and therefore don't exploit all available information in the data. This paper describes generalized least squares detection using gas spectra, presents a new detection method using basis vectors, and compares detection images resulting from applying both methods to synthetic hyperspectral data. PMID:22412306

  14. Detection of Gaseous Plumes using Basis Vectors

    PubMed Central

    Chilton, Lawrence; Walsh, Stephen

    2009-01-01

    Detecting and identifying weak gaseous plumes using thermal imaging data is complicated by many factors. There are several methods currently being used to detect plumes. They can be grouped into two categories: those that use a chemical spectral library and those that don't. The approaches that use chemical libraries include physics-based least squares methods (matched filter). They are “optimal” only if the plume chemical is actually in the search library but risk missing chemicals not in the library. The methods that don't use a chemical spectral library are based on a statistical or data analytical transformation applied to the data. These include principle components, independent components, entropy, Fourier transform, and others. These methods do not explicitly take advantage of the physics of the signal formulation process and therefore don't exploit all available information in the data. This paper describes generalized least squares detection using gas spectra, presents a new detection method using basis vectors, and compares detection images resulting from applying both methods to synthetic hyperspectral data. PMID:22412306

  15. 26 CFR 1.1367-1 - Adjustments to basis of shareholder's stock in an S corporation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... described in section 1367(a)(2)(D) and the oil and gas depletion deduction described in section 1367(a)(2)(E... section 1367(a)(2)(D), and the oil and gas depletion deduction described in section 1367(a)(2)(E); and (4...). The increase in basis described in section 1367(a)(1)(C) for the excess of the deduction for...

  16. 26 CFR 1.1367-2 - Adjustments to basis of indebtedness to shareholder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., and certain oil and gas depletion deductions) exceed the basis of a shareholder's stock in the... oil and gas depletion deductions—there is no nonseparately computed loss) is $10,000. Corporation S...(a)(1) (relating to income items and excess deduction for depletion) exceed the items described...

  17. 26 CFR 1.1367-1 - Adjustments to basis of shareholder's stock in an S corporation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... expenses described in section 1367(a)(2)(D) and the oil and gas depletion deduction described in section... section 1367(a)(2)(D), and the oil and gas depletion deduction described in section 1367(a)(2)(E); and (4...). The increase in basis described in section 1367(a)(1)(C) for the excess of the deduction for...

  18. 26 CFR 1.1367-2 - Adjustments to basis of indebtedness to shareholder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., and certain oil and gas depletion deductions) exceed the basis of a shareholder's stock in the... oil and gas depletion deductions—there is no nonseparately computed loss) is $10,000. Corporation S...(a)(1) (relating to income items and excess deduction for depletion) exceed the items described...

  19. 26 CFR 1.1367-2 - Adjustments to basis of indebtedness to shareholder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., and certain oil and gas depletion deductions) exceed the basis of a shareholder's stock in the... oil and gas depletion deductions—there is no nonseparately computed loss) is $10,000. Corporation S...(a)(1) (relating to income items and excess deduction for depletion) exceed the items described...

  20. 26 CFR 1.1367-1 - Adjustments to basis of shareholder's stock in an S corporation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... expenses described in section 1367(a)(2)(D) and the oil and gas depletion deduction described in section... section 1367(a)(2)(D), and the oil and gas depletion deduction described in section 1367(a)(2)(E); and (4...). The increase in basis described in section 1367(a)(1)(C) for the excess of the deduction for...

  1. BASIS Set Exchange (BSE): Chemistry Basis Sets from the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL) Basis Set Library

    DOE Data Explorer

    Feller, D; Schuchardt, Karen L.; Didier, Brett T.; Elsethagen, Todd; Sun, Lisong; Gurumoorthi, Vidhya; Chase, Jared; Li, Jun

    The Basis Set Exchange (BSE) provides a web-based user interface for downloading and uploading Gaussian-type (GTO) basis sets, including effective core potentials (ECPs), from the EMSL Basis Set Library. It provides an improved user interface and capabilities over its predecessor, the EMSL Basis Set Order Form, for exploring the contents of the EMSL Basis Set Library. The popular Basis Set Order Form and underlying Basis Set Library were originally developed by Dr. David Feller and have been available from the EMSL webpages since 1994. BSE not only allows downloading of the more than 500 Basis sets in various formats; it allows users to annotate existing sets and to upload new sets. (Specialized Interface)

  2. Structural basis of metal hypersensitivity.

    PubMed

    Wang, Yang; Dai, Shaodong

    2013-03-01

    Metal hypersensitivity is a common immune disorder. Human immune systems mount the allergic attacks on metal ions through skin contacts, lung inhalation and metal-containing artificial body implants. The consequences can be simple annoyances to life-threatening systemic illness. Allergic hyper-reactivities to nickel (Ni) and beryllium (Be) are the best-studied human metal hypersensitivities. Ni-contact dermatitis affects 10 % of the human population, whereas Be compounds are the culprits of chronic Be disease (CBD). αβ T cells (T cells) play a crucial role in these hypersensitivity reactions. Metal ions work as haptens and bind to the surface of major histocompatibility complex (MHC) and peptide complex. This modifies the binding surface of MHC and triggers the immune response of T cells. Metal-specific αβ T cell receptors (TCRs) are usually MHC restricted, especially MHC class II (MHCII) restricted. Numerous models have been proposed, yet the mechanisms and molecular basis of metal hypersensitivity remain elusive. Recently, we determined the crystal structures of the Ni and Be presenting human MHCII molecules, HLA-DR52c (DRA*0101, DRB3*0301) and HLA-DP2 (DPA1*0103, DPB1*0201). These structures revealed unusual features of MHCII molecules and shed light on how metal ions are recognized by T cells. PMID:22983897

  3. The autoimmune basis of narcolepsy.

    PubMed

    Mahlios, Josh; De la Herrán-Arita, Alberto K; Mignot, Emmanuel

    2013-10-01

    Narcolepsy is a neurological disorder characterized by excessive daytime sleepiness, cataplexy, hypnagonic hallucinations, sleep paralysis, and disturbed nocturnal sleep patterns. Narcolepsy is caused by the loss of hypocretin (orexin)-producing neurons in the lateral hypothalamus. Evidence, such as a strong association with HLA DQB1*06:02, strongly suggests an autoimmune basis targeting hypocretin neurons. Genome-wide association studies have strengthened the association between narcolepsy and immune system gene polymorphisms, including the identification of polymorphisms in the T cell receptor alpha locus, TNFSF4 (also called OX40L), Cathepsin H (CTSH) the purinergic receptor P2RY11, and the DNA methyltransferase DNMT1. Recently, attention has been raised regarding a spike in cases of childhood narcolepsy in 2010 following the 2009 H1N1 pandemic (pH1N1) in China and vaccination with Pandemrix, an adjuvanted H1N1 vaccine that was used in Europe. How the immune system may be involved in disease initiation and/or progression remains a challenge to researchers. Potential immunological pathways that could lead to the specific elimination of hypocretin producing neurons include molecular mimicry or bystander activation, and are likely a combination of genetic and environmental factors, such as upper airway infections. PMID:23725858

  4. Advanced Fuel Cycle Cost Basis

    SciTech Connect

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2008-03-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  5. Advanced Fuel Cycle Cost Basis

    SciTech Connect

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert

    2007-04-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 26 cost modules—24 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, and high-level waste.

  6. Advanced Fuel Cycle Cost Basis

    SciTech Connect

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2009-12-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  7. Structural basis of metal hypersensitivity

    PubMed Central

    Wang, Yang

    2014-01-01

    Metal hypersensitivity is a common immune disorder. Human immune systems mount the allergic attacks on metal ions through skin contacts, lung inhalation and metal-containing artificial body implants. The consequences can be simple annoyances to life-threatening systemic illness. Allergic hyper-reactivities to nickel (Ni) and beryllium (Be) are the best-studied human metal hypersensitivities. Ni-contact dermatitis affects 10 % of the human population, whereas Be compounds are the culprits of chronic Be disease (CBD). αβ T cells (T cells) play a crucial role in these hypersensitivity reactions. Metal ions work as haptens and bind to the surface of major histocompatibility complex (MHC) and peptide complex. This modifies the binding surface of MHC and triggers the immune response of T cells. Metal-specific αβ T cell receptors (TCRs) are usually MHC restricted, especially MHC class II (MHCII) restricted. Numerous models have been proposed, yet the mechanisms and molecular basis of metal hypersensitivity remain elusive. Recently, we determined the crystal structures of the Ni and Be presenting human MHCII molecules, HLA-DR52c (DRA*0101, DRB3*0301) and HLA-DP2 (DPA1*0103, DPB1*0201). These structures revealed unusual features of MHCII molecules and shed light on how metal ions are recognized by T cells. PMID:22983897

  8. Molecular basis for color vision.

    PubMed

    Yoshizawa, T

    1994-05-01

    Amino acid sequences of four kinds of chicken cone pigments and two kinds of nocturnal gecko visual pigment were determined. Calculations of amino acid identities indicate that gecko pigments should be cone pigments. A phylogenetic tree of visual pigments constructed demonstrated that cone pigments evolved earlier than rod pigments (rhodopsins), indicating that daylight vision including color vision appeared earlier than twilight vision. The divergence of cone pigments to rhodopsins would be caused by replacing basic amino acid residues to acidic ones according to net charge calculations. A comparison between chicken rhodopsin and cone pigments (chicken green and red) displayed that the cone pigments are faster in regeneration from 11-cis retinal and opsin, faster in formation of meta II-intermediate and shorter in lifetime of meta II-intermediate than rhodopsin. These facts would partly explain the rapid dark adaptation, the rapid light response and the low photosensitivity of cones compared with rods. In comparison with di- and tri-chromatic color visions, chicken tetra-chromatic vision was discussed on the basis of both absorption spectra of cone pigments and filtering effect of oil droplets. PMID:8011932

  9. [Neural basis of procedural memory].

    PubMed

    Mochizuki-Kawai, Hiroko

    2008-07-01

    Procedural memory is acquired by trial and error. Our daily life is supported by a number of procedural memories such as those for riding bicycle, typing, reading words, etc. Procedural memory is divided into 3 types; motor, perceptual, and cognitive. Here, the author reviews the cognitive and neural basis of procedural memory according to these 3 types. It is reported that the basal ganglia or cerebellum dysfunction causes deficits in procedural memory. Compared with age-matched healthy participants, patients with Parkinson disease (PD), Huntington disease (HD) or spinocerebellar degeneration (SCD) show deterioration in improvements in motor-type procedural memory tasks. Previous neuroimaging studies have reported that motor-type procedural memory may be supported by multiple brain regions, including the frontal and parietal regions as well as the basal ganglia (cerebellum); this was found with a serial reaction time task (SRT task). Although 2 other types of procedural memory are also maintained by multiple brain regions, the related cerebral areas depend on the type of memory. For example, it was suggested that acquisition of the perceptual type of procedural memory (e.g., ability to read mirror images of words) might be maintained by the bilateral fusiform region, while the acquisition of cognitive procedural memory might be supported by the frontal, parietal, or cerebellar regions as well as the basal ganglia. In the future, we need to cleary understand the neural "network" related to the procedural memory. PMID:18646622

  10. Basis Document for Sludge Stabilization

    SciTech Connect

    RISENMAY, H.R.

    2001-06-18

    DOE-RL recently issued Safety Evaluation Report (SER) amendments to the PFP Final Safety Analysis Report, HNF-SD-CP-SAR-021 Rev. 2. The Justification for Continued Operations for 2736-ZB and plutonium oxides in BTCs Safety Basis change (letter DOE-RL ABD-074) was approved by one of the SERs. Also approved by SER was the revised accident analysis for Magnesium Hydroxide Precipitation Process (MHPP) gloveboxes HC-230C-3 and HC-230C-5 containing increased glovebox inventories and corresponding increases in seismic release consequence. Numerous implementing documents require revision and issuance to implement the SER approvals. The SER authorizing plutonium oxides into BTCs specifically limited the SER authorization scope to ''pure or clean oxides, i.e., 85 wt% or grater Pu, in this feed change'' (SER Section 3.0 Base Information paragraph 4 [page 11]). Comprehensive USQ Evaluation PFP-2001-12 addressed the packaging of Pu alloy metals into BTCs, and the packaging of Pu alloy oxides (powders) into food pack cans and determined that the activities did not represent an USQ. The same information used to make the PFP-2001-12 negative USQ determination is applicable to packaging Pu alloy powders (DOES NOT INCLUDE STABILIZED MHPP MATERIALS OR OXIDES OF MOLYBDATES) into BTCs. Information from USQ Evaluation PFP-2001-12 is included in this USQ Evaluation for packaging of relatively pure Pu oxides and Pu alloy oxides into BTCs.

  11. Vascular basis of mucosal color

    PubMed Central

    Kleinheinz, Johannes; Büchter, André; Fillies, Thomas; Joos, Ulrich

    2005-01-01

    Background Besides the color of the teeth the color of the alveolar gingiva plays a crucial role in esthetic rehabilitation in dento-alveolar treatment. Whereas nowadays the color of the teeth can be determined exactly and individually, the specific influence of the red color of the gingiva on treatment has not been assessed yet. The aim of this study was to evaluate the vascularization as the basis for gingival esthetics. Methods Standardized photographs of defined areas of the alveolar gingiva in operated and non-operated patients were taken and assigned to groups with same characteristics after color comparisons. In addition, histologic and immunohistologic analyses of gingival specimens were performed for qualitative and quantitative assessment of vessels and vascularization. Finally, colors and number of vessels were correlated. Results Our results demonstrated three different constellations of colors of the alveolar gingiva in healthy patients. The operated patients could not be grouped because of disparate depiction. There was a clear correlation between color and vessel number in the alveolar gingiva. Conclusion Our investigations revealed the connections between vascularization and gingival color. Recommendations for specific change or even selection of colors based on the results cannot be given, but the importance of vascularly based incision lines was demonstrated. PMID:16270929

  12. Structural basis of spectrin elasticity

    SciTech Connect

    Shen, B.W.; Stevens, F.J.; Luthi, U.; Goldin, S.B.

    1991-10-17

    A new model of human erythrocyte {alpha}-spectrin is proposed. The secondary structure of human erythrocyte {alpha}-spectrin and its folding into a condensed structure that can convert reversibly in situ, into an elongated configuration is predicted from its deduced protein sequence. Results from conformational and amphipathicity analyses suggest that {alpha}-spectrin consists mainly of short amphipathicity helices interconnected by flexible turns and/or coils. The distribution of charges and amphipathicity of the helices can facilitate their folding into stable domains of 4 and 3 helices surrounding a hydrophobic core. The association between adjacent four- and three-helix domains further organize them into recurring seven-helix motifs that might constitute the basic structural units of the extended {alpha}-spectrin. The elongated spectrin molecule packs, in a sinusoidal fashion, through interactions between neighboring motifs into a compact structure. We suggest that the reversible extension and contraction of this sigmoidally packed structure is the molecular basis of the mechanism by which spectrin contributes to the elasticity of the red cell membrane.

  13. Structural basis of hereditary coproporphyria

    PubMed Central

    Lee, Dong-Sun; Flachsová, Eva; Bodnárová, Michaela; Demeler, Borries; Martásek, Pavel; Raman, C. S.

    2005-01-01

    Hereditary coproporphyria is an autosomal dominant disorder resulting from the half-normal activity of coproporphyrinogen oxidase (CPO), a mitochondrial enzyme catalyzing the antepenultimate step in heme biosynthesis. The mechanism by which CPO catalyzes oxidative decarboxylation, in an extraordinary metal- and cofactor-independent manner, is poorly understood. Here, we report the crystal structure of human CPO at 1.58-Å resolution. The structure reveals a previously uncharacterized tertiary topology comprising an unusually flat seven-stranded β-sheet sandwiched by α-helices. In the biologically active dimer (KD = 5 × 10-7 M), one monomer rotates relative to the second by ≈40° to create an intersubunit interface in close proximity to two independent enzymatic sites. The unexpected finding of citrate at the active site allows us to assign Ser-244, His-258, Asn-260, Arg-262, Asp-282, and Arg-332 as residues mediating substrate recognition and decarboxylation. We favor a mechanism in which oxygen serves as the immediate electron acceptor, and a substrate radical or a carbanion with substantial radical character participates in catalysis. Although several mutations in the CPO gene have been described, the molecular basis for how these alterations diminish enzyme activity is unknown. We show that deletion of residues (392-418) encoded by exon six disrupts dimerization. Conversely, harderoporphyria-causing K404E mutation precludes a type I β-turn from retaining the substrate for the second decarboxylation cycle. Together, these findings resolve several questions regarding CPO catalysis and provide insights into hereditary coproporphyria. PMID:16176984

  14. Structural basis of hereditary coproporphyria.

    PubMed

    Lee, Dong-Sun; Flachsová, Eva; Bodnárová, Michaela; Demeler, Borries; Martásek, Pavel; Raman, C S

    2005-10-01

    Hereditary coproporphyria is an autosomal dominant disorder resulting from the half-normal activity of coproporphyrinogen oxidase (CPO), a mitochondrial enzyme catalyzing the antepenultimate step in heme biosynthesis. The mechanism by which CPO catalyzes oxidative decarboxylation, in an extraordinary metal- and cofactor-independent manner, is poorly understood. Here, we report the crystal structure of human CPO at 1.58-A resolution. The structure reveals a previously uncharacterized tertiary topology comprising an unusually flat seven-stranded beta-sheet sandwiched by alpha-helices. In the biologically active dimer (K(D) = 5 x 10(-7) M), one monomer rotates relative to the second by approximately 40 degrees to create an intersubunit interface in close proximity to two independent enzymatic sites. The unexpected finding of citrate at the active site allows us to assign Ser-244, His-258, Asn-260, Arg-262, Asp-282, and Arg-332 as residues mediating substrate recognition and decarboxylation. We favor a mechanism in which oxygen serves as the immediate electron acceptor, and a substrate radical or a carbanion with substantial radical character participates in catalysis. Although several mutations in the CPO gene have been described, the molecular basis for how these alterations diminish enzyme activity is unknown. We show that deletion of residues (392-418) encoded by exon six disrupts dimerization. Conversely, harderoporphyria-causing K404E mutation precludes a type I beta-turn from retaining the substrate for the second decarboxylation cycle. Together, these findings resolve several questions regarding CPO catalysis and provide insights into hereditary coproporphyria. PMID:16176984

  15. Gas sensing in nematodes.

    PubMed

    Carrillo, M A; Hallem, E A

    2015-01-01

    Nearly all animals are capable of sensing changes in environmental oxygen (O2) and carbon dioxide (CO2) levels, which can signal the presence of food, pathogens, conspecifics, predators, or hosts. The free-living nematode Caenorhabditis elegans is a powerful model system for the study of gas sensing. C. elegans detects changes in O2 and CO2 levels and integrates information about ambient gas levels with other internal and external cues to generate context-appropriate behavioral responses. Due to its small nervous system and amenability to genetic and genomic analyses, the functional properties of its gas-sensing microcircuits can be dissected with single-cell resolution, and signaling molecules and natural genetic variations that modulate gas responses can be identified. Here, we discuss the neural basis of gas sensing in C. elegans, and highlight changes in gas-evoked behaviors in the context of other sensory cues and natural genetic variations. We also discuss gas sensing in other free-living nematodes and parasitic nematodes, focusing on how gas-sensing behavior has evolved to mediate species-specific behavioral requirements. PMID:24906953

  16. Positive basis for surface skein algebras

    PubMed Central

    Thurston, Dylan Paul

    2014-01-01

    We show that the twisted SL2 skein algebra of a surface has a natural basis (the bracelets basis) that is positive, in the sense that the structure constants for multiplication are positive integers. PMID:24982193

  17. 10 CFR 830.202 - Safety basis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Safety basis. 830.202 Section 830.202 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT Safety Basis Requirements § 830.202 Safety basis. (a) The contractor responsible for a hazard category 1, 2, or 3 DOE nuclear facility must establish and maintain the safety...

  18. Conjoined twins: theoretical embryologic basis.

    PubMed

    Spencer, R

    1992-06-01

    A theoretical basis for the embryology of conjoined twins was formulated from clinical experience with ten cases and extensive review of pertinent embryologic and clinical literature, including over 500 cases. Regarding the age old question of fusion or fission, it is concluded that there is no known embryologic process by which conjoined twins can be formed by fission but firm evidence to support fusion in all cases. Whether the fusion occurs between embryos on one embryonic disc or on two is of no consequence since they are all monovular. Intact ectoderm will not fuse to intact ectoderm, and all seven types of conjoined twins are explained by seven possible sites of union in the early embryo. One new term is proposed: parapagus, from the Greek para, meaning "side," combined with pagus, meaning "fixed"; this is the group formerly called dicephalus or diprosopos. These anterolaterally united parapagus twins must result from two nearly parallel notochords in close proximity; craniopagi and pygopagi from fusion at the cranial and caudal neuropores, respectively; cephalopagi and ischiopagi from union at the pharyngeal and cloacal membranes, respectively; thoracopagi from merging of the cardiac anlage; and omphalopagi from fusion of the umbilicus or of the edges of two embryonic discs in any area not including the above sites. Parasitic twins result from embryonic death of one twin, leaving various portions of the body vascularized by the surviving autosite. The rarity of cases (2) not easily explained by the above theories, and the nearly 6% of twins with two umbilical cords arising from the placenta would seem to support these conclusions. Should one wish to learn the methods of a conjurer, he might vainly watch the latter's customary repertoire, and, so long as everything went smoothly, might never obtain a clue to the mysterious performance, baffled by the precision of the manipulations and the complexity of the apparatus; if, however, a single error were made in

  19. Hydrodynamic gas mixture separation

    SciTech Connect

    Stolyarov, A.A.

    1982-02-10

    The separation of gas mixtures is the basis of many chemical, petrochemical, and gas processes. Classical separation methods (absorption, adsorption, condensation, and freezing) require cumbersome and complex equipment. No adequate solution is provided by the cheapening and simplification of gas-processing apparatus and separation methods by hydration and diffusion. For example, an apparatus for extracting helium from natural gas by diffusion has a throughput of gas containing 0.45% helium of 117,000 m/sup 3//h and in the first stage has teflon membranes working at a pressure difference of 63.3x10/sup 5/ Pa of area 79,000 m/sup 2/, and the specific cost of the apparatus was 8500 dollars per m/sup 3//h of helium. Therefore, vigorous studies are being conducted on new ways of efficient separation of gas mixtures that are cheaper and simpler. Here we consider a novel method of physically essentially reversible separation of gas mixtures, which involves some features of single-phase supersonic flows.

  20. Authorization basis for the 209-E Building

    SciTech Connect

    TIFFANY, M.S.

    1999-02-23

    This Authorization Basis document is one of three documents that constitute the Authorization Basis for the 209-E Building. Per the U.S. Department of Energy, Richland Operations Office (RL) letter 98-WSD-074, this document, the 209-E Building Preliminary Hazards Analysis (WHC-SD-WM-TI-789), and the 209-E Building Safety Evaluation Report (97-WSD-074) constitute the Authorization Basis for the 209-E Building. This Authorization Basis and the associated controls and safety programs will remain in place until safety documentation addressing deactivation of the 209-E Building is developed by the contractor and approved by RL.

  1. Estimating the CCSD basis-set limit energy from small basis sets: basis-set extrapolations vs additivity schemes

    SciTech Connect

    Spackman, Peter R.; Karton, Amir

    2015-05-15

    Coupled cluster calculations with all single and double excitations (CCSD) converge exceedingly slowly with the size of the one-particle basis set. We assess the performance of a number of approaches for obtaining CCSD correlation energies close to the complete basis-set limit in conjunction with relatively small DZ and TZ basis sets. These include global and system-dependent extrapolations based on the A + B/L{sup α} two-point extrapolation formula, and the well-known additivity approach that uses an MP2-based basis-set-correction term. We show that the basis set convergence rate can change dramatically between different systems(e.g.it is slower for molecules with polar bonds and/or second-row elements). The system-dependent basis-set extrapolation scheme, in which unique basis-set extrapolation exponents for each system are obtained from lower-cost MP2 calculations, significantly accelerates the basis-set convergence relative to the global extrapolations. Nevertheless, we find that the simple MP2-based basis-set additivity scheme outperforms the extrapolation approaches. For example, the following root-mean-squared deviations are obtained for the 140 basis-set limit CCSD atomization energies in the W4-11 database: 9.1 (global extrapolation), 3.7 (system-dependent extrapolation), and 2.4 (additivity scheme) kJ mol{sup –1}. The CCSD energy in these approximations is obtained from basis sets of up to TZ quality and the latter two approaches require additional MP2 calculations with basis sets of up to QZ quality. We also assess the performance of the basis-set extrapolations and additivity schemes for a set of 20 basis-set limit CCSD atomization energies of larger molecules including amino acids, DNA/RNA bases, aromatic compounds, and platonic hydrocarbon cages. We obtain the following RMSDs for the above methods: 10.2 (global extrapolation), 5.7 (system-dependent extrapolation), and 2.9 (additivity scheme) kJ mol{sup –1}.

  2. 42 CFR 408.1 - Statutory basis.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Statutory basis. 408.1 Section 408.1 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM PREMIUMS FOR SUPPLEMENTARY MEDICAL INSURANCE General Provisions § 408.1 Statutory basis. (a) This part implements certain provisions of sections...

  3. 21 CFR 120.9 - Legal basis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Legal basis. 120.9 Section 120.9 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS General Provisions § 120.9 Legal basis. Failure of a processor to have and...

  4. 42 CFR 409.1 - Statutory basis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Statutory basis. 409.1 Section 409.1 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM HOSPITAL INSURANCE BENEFITS Hospital Insurance Benefits: General Provisions § 409.1 Statutory basis. This part is based on the identified provisions...

  5. Stimulus Overselectivity: Empirical Basis and Diagnostic Methods

    ERIC Educational Resources Information Center

    Cipani, Ennio

    2012-01-01

    This paper presents the empirical basis for the phenomena known as stimulus overselectivity. Stimulus overselectivity involves responding on the basis of a restricted range of elements or features that are discriminative for reinforcement. The manner in which such a response pattern impedes the skill acquisition in children is identified. A…

  6. 42 CFR 460.2 - Basis.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Basis. 460.2 Section 460.2 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Basis,...

  7. 42 CFR 460.2 - Basis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Basis. 460.2 Section 460.2 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Basis,...

  8. 42 CFR 460.2 - Basis.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Basis. 460.2 Section 460.2 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Basis,...

  9. 42 CFR 460.2 - Basis.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Basis. 460.2 Section 460.2 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Basis,...

  10. 42 CFR 460.2 - Basis.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Basis. 460.2 Section 460.2 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Basis,...

  11. 14 CFR 1203.100 - Legal basis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...”), and the standards for such classification, are established by the “the Order” (E.O. 12958, 3 CFR, 1996... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Legal basis. 1203.100 Section 1203.100....100 Legal basis. (a) Executive Order 12958 (hereinafter referred to as “the Order”)....

  12. 47 CFR 64.2317 - Unbundled basis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... publisher may request that a carrier unbundle subscriber list information on any basis for the purpose of... directory publisher requests and no other listings, products, or services; or (2) Subscriber list... internal systems do not permit it unbundle subscriber list information on the basis a directory...

  13. 47 CFR 64.2317 - Unbundled basis.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... publisher may request that a carrier unbundle subscriber list information on any basis for the purpose of... directory publisher requests and no other listings, products, or services; or (2) Subscriber list... internal systems do not permit it unbundle subscriber list information on the basis a directory...

  14. 47 CFR 64.2317 - Unbundled basis.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... publisher may request that a carrier unbundle subscriber list information on any basis for the purpose of... directory publisher requests and no other listings, products, or services; or (2) Subscriber list... internal systems do not permit it unbundle subscriber list information on the basis a directory...

  15. 47 CFR 64.2317 - Unbundled basis.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... publisher may request that a carrier unbundle subscriber list information on any basis for the purpose of... directory publisher requests and no other listings, products, or services; or (2) Subscriber list... internal systems do not permit it unbundle subscriber list information on the basis a directory...

  16. 47 CFR 64.2317 - Unbundled basis.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... publisher may request that a carrier unbundle subscriber list information on any basis for the purpose of... directory publisher requests and no other listings, products, or services; or (2) Subscriber list... internal systems do not permit it unbundle subscriber list information on the basis a directory...

  17. Two petroleum systems in the Sacramento Basin, California - A basis for new discoveries

    SciTech Connect

    Magoon, L.B. ); Castano, J.R. ); Lillis, P. ); Mackevett, N.H.; Naeser, N. )

    1994-04-01

    The Sacramento basin is a north-trending fore-arc basin that contains Lat Jurassic to Holocene sedimentary rocks that become thicker to the south and are overpressured at depth. The basin fill is about 300 km long, 80 km wide, and as much as 16 km thick. Two petroleum systems occur in the Sacramento basin. The Dobbins-Forbes( ) gas system, which contained about 2.25 tcf (10[sup 12]ft[sup 3]) of recoverable gas, underlies the Winters-Domingine( ) gas system, which contained about 6.89 tcf of recoverable gas. Gas migrated laterally and to the north as much as 200 km in the Dobbins-Forbes( ) system, whereas in the Winters-Domingine( ) system, gas first migrated vertically and then crossed the Midland fault to the east for up to 40 km. For both systems, depth of gas production from reservoir rocks of Lake Cretaceous to Oligocene in different trap types is less than 3 km. By applying the petroleum-system concept and information about the geology and geochemistry available for this province, this study- provides a new testable hypthesis for the origin, migration, and accumulation of gas in the Sacramento basin. By reinterpreting some of the natural gas information, gas wetness, gas-oil ratio, vectors of migration, hydrocarbon volume, and thermal history, two petroleum systems are identified. Understanding of the origin of known accumulations in this province provides a basis for new plays that should lead to discoveries with substantial reserves.

  18. Gas gangrene

    MedlinePlus

    Tissue infection - Clostridial; Gangrene - gas; Myonecrosis; Clostridial infection of tissues; Necrotizing soft tissue infection ... Gas gangrene is most often caused by bacteria called Clostridium perfringens. It also can be caused by ...

  19. Energy balance, greenhouse gas emissions, and profitability of thermobarical pretreatment of cattle waste in anaerobic digestion.

    PubMed

    Budde, Jörn; Prochnow, Annette; Plöchl, Matthias; Suárez Quiñones, Teresa; Heiermann, Monika

    2016-03-01

    In this study modeled full scale application of thermobarical hydrolysis of less degradable feedstock for biomethanation was assessed in terms of energy balance, greenhouse gas emissions, and economy. Data were provided whether the substitution of maize silage as feedstock for biogas production by pretreated cattle wastes is beneficial in full-scale application or not. A model device for thermobarical treatment has been suggested for and theoretically integrated in a biogas plant. The assessment considered the replacement of maize silage as feedstock with liquid and/or solid cattle waste (feces, litter, and feed residues from animal husbandry of high-performance dairy cattle, dry cows, and heifers). The integration of thermobarical pretreatment is beneficial for raw material with high contents of organic dry matter and ligno-cellulose: Solid cattle waste revealed very short payback times, e.g. 9 months for energy, 3 months for greenhouse gases, and 3 years 3 months for economic amortization, whereas, in contrast, liquid cattle waste did not perform positive replacement effects in this analysis. PMID:26709050

  20. Gas separating

    DOEpatents

    Gollan, Arye

    1988-01-01

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  1. Gas separating

    DOEpatents

    Gollan, Arye Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  2. Gas evolution from geopressured brines

    SciTech Connect

    Matthews, C.S.

    1980-06-01

    The process of gas evolution from geopressured brine is examined using as a basis the many past studies of gas evolution from liquids in porous media. A discussion of a number of speculations that have been made concerning gas evolution from geopressured brines is provided. According to one, rapid pressure reduction will cause methane gas to evolve as when one opens a champagne bottle. It has been further speculated that evolved methane gas would migrate up to form an easily producible cap. As a result of detailed analyses, it can be concluded that methane gas evolution from geopressured brines is far too small to ever form a connected gas saturation except very near to the producing well. Thus, no significant gas cap could ever form. Because of the very low solubility of methaned in brine, the process of methane gas evolution is not at all analogous to evolution of carbon dioxide from champagne. A number of other speculations and questions on gas evolution are analyzed, and procedures for completing wells and testing geopressured brine reservoirs are discussed, with the conclusion that presently used procedures will provide adequate data to enable a good evaluation of this resource.

  3. 21 CFR 120.9 - Legal basis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... CONSUMPTION HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS General Provisions § 120.9 Legal basis. Failure of a processor to have and to implement a Hazard Analysis and Critical Control Point (HACCP... implementation of its HACCP system....

  4. 21 CFR 120.9 - Legal basis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... CONSUMPTION HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS General Provisions § 120.9 Legal basis. Failure of a processor to have and to implement a Hazard Analysis and Critical Control Point (HACCP... implementation of its HACCP system....

  5. Nonlocality of orthogonal product basis quantum states

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Chao; Gao, Fei; Tian, Guo-Jing; Cao, Tian-Qing; Wen, Qiao-Yan

    2014-08-01

    In this paper, we mainly study the local indistinguishability of mutually orthogonal product basis quantum states in the high-dimensional quantum systems. In the Hilbert space of 3⊗3, Walgate and Hardy [Phys. Rev. Lett. 89, 147901 (2002), 10.1103/PhysRevLett.89.147901] presented a very simple proof for nonlocality of nine orthogonal product basis quantum states which are given by Bennett et al. [Phys. Rev. A 59, 1070 (1999), 10.1103/PhysRevA.59.1070]. In the quantum system of d⊗d, where d is odd, we construct d2 orthogonal product basis quantum states and prove these states are locally indistinguishable. Then we are able to construct some locally indistinguishable product basis quantum states in the multipartite systems. All these results reveal the phenomenon of "nonlocality without entanglement."

  6. THEORETICAL BASIS FOR MODELING ELEMENT CYCLING

    EPA Science Inventory

    A biophysical basis for modeling element cycling is described. The scheme consists of element cycles, organisms necessary to completely catalyze all the component reactions, and higher organisms as structurally complex systems and as subsystems of more complex ecosystems, all to ...

  7. Basic Achievement Skills Individual Screener (BASIS).

    ERIC Educational Resources Information Center

    Ysseldyke, James E.

    1985-01-01

    Reviews the behaviors sampled, test administration, scoring, norms, reliability, and validity of the Basic Achievement Skills Individual Screener (BASIS), an individually administered test that measures skill development in reading, mathematics, spelling, and writing. (BL)

  8. Elements of gas contracts

    SciTech Connect

    O`Neal, J.

    1995-12-01

    The gas marketing scene has taken on a new look from the days of the {open_quotes}Long Term{close_quotes} or {open_quotes}Life of Lease{close_quotes} Contracts. In the past natural gas was of ten sold direct from the wellhead or a producer-owned facility to a pipeline company at a flat rate price and the only parties involved were producer or seller and buyer. Today, the parties involved in the marketing process might include a gathering entity to gather gas at a central point and provide gathering, compression and/or dehydration services; multiple pipeline companies for transportation; sales representatives or marketing brokers to negotiate a sale of the available gas on a monthly basis; and purchasers or end users. New terms have also been introduced in the process such as: {open_quotes}LDC{close_quotes} (local distribution company), {open_quotes}FERC Order 636{close_quotes}, {open_quotes}Price Delivered-to-Pipeline{close_quotes} and the various {open_quotes}levels of Service{close_quotes} under Gas Sales and Purchase Agreements. Four common levels of service are: {open_quotes}Firm{close_quotes}, {open_quotes}Baseload{close_quotes}, {open_quotes}Swing{close_quotes} and {open_quotes}Baseload/Operational{close_quotes}. It is evident that current marketing plans often require a separate contract for each service or commitment. Contract contents vary greatly, but most contain the following elements.

  9. Nanoplasmonics simulations at the basis set limit through completeness-optimized, local numerical basis sets

    SciTech Connect

    Rossi, Tuomas P. Sakko, Arto; Puska, Martti J.; Lehtola, Susi; Nieminen, Risto M.

    2015-03-07

    We present an approach for generating local numerical basis sets of improving accuracy for first-principles nanoplasmonics simulations within time-dependent density functional theory. The method is demonstrated for copper, silver, and gold nanoparticles that are of experimental interest but computationally demanding due to the semi-core d-electrons that affect their plasmonic response. The basis sets are constructed by augmenting numerical atomic orbital basis sets by truncated Gaussian-type orbitals generated by the completeness-optimization scheme, which is applied to the photoabsorption spectra of homoatomic metal atom dimers. We obtain basis sets of improving accuracy up to the complete basis set limit and demonstrate that the performance of the basis sets transfers to simulations of larger nanoparticles and nanoalloys as well as to calculations with various exchange-correlation functionals. This work promotes the use of the local basis set approach of controllable accuracy in first-principles nanoplasmonics simulations and beyond.

  10. Nanoplasmonics simulations at the basis set limit through completeness-optimized, local numerical basis sets.

    PubMed

    Rossi, Tuomas P; Lehtola, Susi; Sakko, Arto; Puska, Martti J; Nieminen, Risto M

    2015-03-01

    We present an approach for generating local numerical basis sets of improving accuracy for first-principles nanoplasmonics simulations within time-dependent density functional theory. The method is demonstrated for copper, silver, and gold nanoparticles that are of experimental interest but computationally demanding due to the semi-core d-electrons that affect their plasmonic response. The basis sets are constructed by augmenting numerical atomic orbital basis sets by truncated Gaussian-type orbitals generated by the completeness-optimization scheme, which is applied to the photoabsorption spectra of homoatomic metal atom dimers. We obtain basis sets of improving accuracy up to the complete basis set limit and demonstrate that the performance of the basis sets transfers to simulations of larger nanoparticles and nanoalloys as well as to calculations with various exchange-correlation functionals. This work promotes the use of the local basis set approach of controllable accuracy in first-principles nanoplasmonics simulations and beyond. PMID:25747068

  11. DEVELOPMENT OF A MATHEMATICAL BASIS FOR RELATING SLUDGE PROPERTIES TO FGD-SCRUBBER OPERATING VARIABLES

    EPA Science Inventory

    The report gives results of research to investigate prospects for increasing the size of calcium sulfite sludge particles in flue gas desulfurization systems. The approach included four work packages: a literature survey and development of a mathematical basis for predicting calc...

  12. 26 CFR 1.743-1 - Optional adjustment to basis of partnership property.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Asset 2. (5) Depletion. Where an adjustment is made under section 743(b) to the basis of partnership property subject to depletion, any depletion allowance is determined separately for each partner, including... partnerships that hold oil and gas properties that are depleted at the partner level under section...

  13. 26 CFR 1.743-1 - Optional adjustment to basis of partnership property.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Asset 2. (5) Depletion. Where an adjustment is made under section 743(b) to the basis of partnership property subject to depletion, any depletion allowance is determined separately for each partner, including... partnerships that hold oil and gas properties that are depleted at the partner level under section...

  14. 26 CFR 1.743-1 - Optional adjustment to basis of partnership property.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Asset 2. (5) Depletion. Where an adjustment is made under section 743(b) to the basis of partnership property subject to depletion, any depletion allowance is determined separately for each partner, including... partnerships that hold oil and gas properties that are depleted at the partner level under section...

  15. Gas vesicles.

    PubMed Central

    Walsby, A E

    1994-01-01

    The gas vesicle is a hollow structure made of protein. It usually has the form of a cylindrical tube closed by conical end caps. Gas vesicles occur in five phyla of the Bacteria and two groups of the Archaea, but they are mostly restricted to planktonic microorganisms, in which they provide buoyancy. By regulating their relative gas vesicle content aquatic microbes are able to perform vertical migrations. In slowly growing organisms such movements are made more efficiently than by swimming with flagella. The gas vesicle is impermeable to liquid water, but it is highly permeable to gases and is normally filled with air. It is a rigid structure of low compressibility, but it collapses flat under a certain critical pressure and buoyancy is then lost. Gas vesicles in different organisms vary in width, from 45 to > 200 nm; in accordance with engineering principles the narrower ones are stronger (have higher critical pressures) than wide ones, but they contain less gas space per wall volume and are therefore less efficient at providing buoyancy. A survey of gas-vacuolate cyanobacteria reveals that there has been natural selection for gas vesicles of the maximum width permitted by the pressure encountered in the natural environment, which is mainly determined by cell turgor pressure and water depth. Gas vesicle width is genetically determined, perhaps through the amino acid sequence of one of the constituent proteins. Up to 14 genes have been implicated in gas vesicle production, but so far the products of only two have been shown to be present in the gas vesicle: GvpA makes the ribs that form the structure, and GvpC binds to the outside of the ribs and stiffens the structure against collapse. The evolution of the gas vesicle is discussed in relation to the homologies of these proteins. Images PMID:8177173

  16. Influence of basis sets and electron correlation on theoretically predicted infrared intensities

    SciTech Connect

    Miller, M.D. ); Jensen, F. ); Chapman, O.L.; Houk, K.N. )

    1989-06-01

    A systematic study of the effects of basis sets and electron correlation on calculated infrared intensities has been performed with ab initio molecular orbital calculations and Moeller-Plesset perturbation theory. Absolute IR intensities of hydrogen fluoride, hydroxy radical, carbon monoxide, hydrogen cyanide, and formaldehyde have been calculated with basis sets ranging from 3-21G to 6-311++G(2dd{prime},2pp{prime}) and with electron correlation corrections up through MP4(SDTQ). A basis set with polarization and diffuse functions is necessary to obtain reasonably accurate intensities. Electron correlation significantly improves the agreement between experimental and calculated values. Except for carbon monoxide, the intensities calculated at the MP4 level compare favorably with experimental intensities, the errors being less than the measured difference between those obtained from inert-gas matrices at low temperature and those reported for the gas phase.

  17. Gas separating

    DOEpatents

    Gollan, A.Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  18. Gas separating

    DOEpatents

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  19. Gas magnetometer

    DOEpatents

    Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

    2016-05-03

    Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.

  20. Full Waveform Inversion with Optimal Basis Functions

    NASA Astrophysics Data System (ADS)

    Sun, Gang; Chang, Qianshun; Sheng, Ping

    2003-03-01

    Based on the approach suggested by Tarantola, and Gauthier etal., we show that the alternate use of the step (linear) function basis and the block function (quasi-δ function) basis can give accurate full waveform inversion results for the layered acoustic systems, starting from a uniform background. Our method is robust against additive white noise (up to 20% of the signal) and can resolve layers that are comparable to or smaller than a wavelength in thickness. The physical reason for the success of our approach is illustrated through a simple example.

  1. The Q field, a variable quaternion basis

    SciTech Connect

    Efremov, A.P.

    1986-06-01

    The author introduces the concept of the Q field as a 2 x 2 matrix representation of the variable basis of vectors satisfying the rule of multiplication of quaternion imaginary numbers and as an element of the group of transformations of the basis preserving the invariance of this multiplication rule. The rule for projecting such matrices on a given direction is determined with the help of the characteristic functions of the matrices-vectors of the Q field. The differential structure of Q fields is studied and the theory developed is illustrated by an example of a model-topological classification of particles according to the magnitude of their spin.

  2. Heavy quarkonium in a holographic basis

    NASA Astrophysics Data System (ADS)

    Li, Yang; Maris, Pieter; Zhao, Xingbo; Vary, James P.

    2016-07-01

    We study the heavy quarkonium within the basis light-front quantization approach. We implement the one-gluon exchange interaction and a confining potential inspired by light-front holography. We adopt the holographic light-front wavefunction (LFWF) as our basis function and solve the non-perturbative dynamics by diagonalizing the Hamiltonian matrix. We obtain the mass spectrum for charmonium and bottomonium. With the obtained LFWFs, we also compute the decay constants and the charge form factors for selected eigenstates. The results are compared with the experimental measurements and with other established methods.

  3. Chemical basis of rough and smooth variation in mycobacteria.

    PubMed Central

    Belisle, J T; Brennan, P J

    1989-01-01

    Rough and smooth colony variants of Mycobacterium kansasii were compared with respect to surface glycolipid composition. Thin-layer chromatography of the native glycolipid antigens, gas chromatography of the constituent sugars, and in situ probing with an appropriate monoclonal antibody by colony dot blot enzyme-linked immunosorbent assay and immunogold labeling demonstrated that all M. kansasii strains of smooth colony morphology contain on their surfaces the recently described trehalose-containing lipooligosaccharides, whereas all rough variants were devoid of such surface antigens. Yet all strains, rough and smooth, contained another glycolipid, the M. kansasii-specific phenolic glycolipid. Previous studies by others had shown that the rough forms of M. kansasii persist longer than smooth variants in experimentally infected mice. Therefore, this study may provide some insight into the question of the chemical basis of pathogenesis in certain mycobacteria. Images PMID:2722755

  4. Improved gas mixtures for gas-filled particle detectors

    DOEpatents

    Christophorou, L.G.; McCorkle, D.L.; Maxey, D.V.; Carter, J.G.

    Improved binary and tertiary gas mixture for gas-filled particle detectors are provided. The components are chosen on the basis of the principle that the first component is one gas or mixture of two gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a gas (Ar) having a very small cross section at and below about 0.5 eV; whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electron field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.

  5. Gas mixtures for gas-filled radiation detectors

    DOEpatents

    Christophorou, Loucas G.; McCorkle, Dennis L.; Maxey, David V.; Carter, James G.

    1982-01-05

    Improved binary and ternary gas mixtures for gas-filled radiation detectors are provided. The components are chosen on the basis of the principle that the first component is one molecular gas or mixture of two molecular gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a noble gas having a very small cross section at and below about 1.0 eV, whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electric field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.

  6. Improved gas mixtures for gas-filled radiation detectors

    DOEpatents

    Christophorou, L.G.; McCorkle, D.L.; Maxey, D.V.; Carter, J.G.

    1980-03-28

    Improved binary and ternary gas mixtures for gas-filled radiation detectors are provided. The components are chosen on the basis of the principle that the first component is one molecular gas or mixture of two molecular gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a noble gas having a very small cross section at and below about 1.0 eV, whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electric field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.

  7. Gas mixtures for gas-filled particle detectors

    DOEpatents

    Christophorou, Loucas G.; McCorkle, Dennis L.; Maxey, David V.; Carter, James G.

    1980-01-01

    Improved binary and tertiary gas mixtures for gas-filled particle detectors are provided. The components are chosen on the basis of the principle that the first component is one gas or mixture of two gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a gas (Ar) having a very small cross section at and below aout 0.5 eV, whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electron field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.

  8. Natural gas imports and exports, third quarter report 2000

    SciTech Connect

    2000-12-01

    The Office of Natural Gas and Petroleum Import and Export Activities prepares quarterly reports showing natural gas import and export activity. Companies are required to file quarterly reports. Attachments show the percentage of takes to maximum firm contract levels and the weighted average per unit price for each of the long-term importers during the 5 most recent quarters, volumes and prices of gas purchased by long-term importers and exporters during the past 12 months, volume and price data for gas imported on a short-term or spot market basis, and the gas exported on a short-term or spot market basis to Canada and Mexico.

  9. Natural gas imports and exports, fourth quarter report 1999

    SciTech Connect

    2000-03-01

    The Office of Natural Gas and Petroleum Import and Export Activities prepares quarterly reports showing natural gas import and export activity. Companies are required to file quarterly reports. Attachments show the percentage of takes to maximum firm contract levels and the weighted average per unit price for each of the long-term importers during the five most recent quarters, volumes and prices of gas purchased by long-term importers and exporters during the past 12 months, volume and price data for gas imported on a short-term or spot market basis, and the gas exported on a short-term or spot market basis to Canada and Mexico.

  10. Natural gas imports and exports, first quarter report 2000

    SciTech Connect

    2000-06-01

    The Office of Natural Gas and Petroleum Import and Export Activities prepares quarterly reports showing natural gas import and export activity. Companies are required to file quarterly reports. Attachments show the percentage of takes to maximum firm contract levels and the weighted average per unit price for each of the long-term importers during the 5 most recent reporting quarters, volumes and prices of gas purchased by long-term importers and exporters during the past 12 months, volume and price data for gas imported on a short-term or spot market basis, and the gas exported on a short-term or spot market basis to Canada and Mexico.

  11. Gas Chromatography.

    ERIC Educational Resources Information Center

    Karasek, Francis W.; And Others

    1984-01-01

    This review covers fundamental developments in gas chromatography during 1982 and 1983. Literature is considered under these headings: columns; liguid phases; solid supports; sorption processes and solvents; open tubular column gas chromatography; instrumentation; high-resolution columns and applications; other techniques; qualitative and…

  12. 340 waste handling facility interim safety basis

    SciTech Connect

    VAIL, T.S.

    1999-04-01

    This document presents an interim safety basis for the 340 Waste Handling Facility classifying the 340 Facility as a Hazard Category 3 facility. The hazard analysis quantifies the operating safety envelop for this facility and demonstrates that the facility can be operated without a significant threat to onsite or offsite people.

  13. The neural basis of phantom limb pain.

    PubMed

    Flor, Herta; Diers, Martin; Andoh, Jamila

    2013-07-01

    A recent study suggests that brain changes in amputees may be pain-induced, questioning maladaptive plasticity as a neural basis of phantom pain. These findings add valuable information on cortical reorganization after amputation. We suggest further lines of research to clarify the mechanisms that underlie phantom pain. PMID:23608362

  14. THE METABOLIC BASIS OF ARSENIC TOXICITY

    EPA Science Inventory

    The Metabolic Basis of Arsenic Toxicity

    David J. Thomas, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC

    Methylati...

  15. A reduced basis localized orthogonal decomposition

    NASA Astrophysics Data System (ADS)

    Abdulle, Assyr; Henning, Patrick

    2015-08-01

    In this work we combine the framework of the Reduced Basis method (RB) with the framework of the Localized Orthogonal Decomposition (LOD) in order to solve parametrized elliptic multiscale problems. The idea of the LOD is to split a high dimensional Finite Element space into a low dimensional space with comparably good approximation properties and a remainder space with negligible information. The low dimensional space is spanned by locally supported basis functions associated with the node of a coarse mesh obtained by solving decoupled local problems. However, for parameter dependent multiscale problems, the local basis has to be computed repeatedly for each choice of the parameter. To overcome this issue, we propose an RB approach to compute in an "offline" stage LOD for suitable representative parameters. The online solution of the multiscale problems can then be obtained in a coarse space (thanks to the LOD decomposition) and for an arbitrary value of the parameters (thanks to a suitable "interpolation" of the selected RB). The online RB-LOD has a basis with local support and leads to sparse systems. Applications of the strategy to both linear and nonlinear problems are given.

  16. 42 CFR 489.1 - Statutory basis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Statutory basis. 489.1 Section 489.1 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION PROVIDER AGREEMENTS AND SUPPLIER APPROVAL General Provisions § 489.1 Statutory...

  17. The Emotional and Moral Basis of Rationality

    ERIC Educational Resources Information Center

    Boostrom, Robert

    2013-01-01

    This chapter explores the basis of rationality, arguing that critical thinking tends to be taught in schools as a set of skills because of the failure to recognize that choosing to think critically depends on the prior development of stable sentiments or moral habits that nourish a rational self. Primary among these stable sentiments are the…

  18. 42 CFR 488.800 - Statutory basis.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Statutory basis. 488.800 Section 488.800 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Alternative Sanctions for...

  19. 47 CFR 10.1 - Basis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM General Information § 10.1 Basis. The rules in this part are issued pursuant to the authority contained in the Warning, Alert, and... of June 26, 2006, Public Alert and Warning System, 71 FR 36975, June 26, 2006....

  20. 47 CFR 10.1 - Basis.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... FEDERAL COMMUNICATIONS COMMISSION GENERAL WIRELESS EMERGENCY ALERTS General Information § 10.1 Basis. The rules in this part are issued pursuant to the authority contained in the Warning, Alert, and Response..., 2006, Public Alert and Warning System, 71 FR 36975, June 26, 2006....

  1. 47 CFR 10.1 - Basis.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM General Information § 10.1 Basis. The rules in this part are issued pursuant to the authority contained in the Warning, Alert, and... of June 26, 2006, Public Alert and Warning System, 71 FR 36975, June 26, 2006....

  2. 47 CFR 10.1 - Basis.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... FEDERAL COMMUNICATIONS COMMISSION GENERAL WIRELESS EMERGENCY ALERTS General Information § 10.1 Basis. The rules in this part are issued pursuant to the authority contained in the Warning, Alert, and Response..., 2006, Public Alert and Warning System, 71 FR 36975, June 26, 2006....

  3. 47 CFR 10.1 - Basis.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM General Information § 10.1 Basis. The rules in this part are issued pursuant to the authority contained in the Warning, Alert, and... of June 26, 2006, Public Alert and Warning System, 71 FR 36975, June 26, 2006....

  4. 29 CFR 541.605 - Fee basis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... payment meets the minimum amount of salary required for exemption under these regulations, the amount paid... artist paid $250 for a picture that took 20 hours to complete meets the minimum salary requirement for... Salary Requirements § 541.605 Fee basis. (a) Administrative and professional employees may be paid on...

  5. The molecular basis of positional information.

    PubMed

    Summerbell, D; Smith, J C; Maden, M

    1991-01-01

    Embryologists have dreamed of their own particular philosophers stone for 100 years. During that time they have repeatedly demonstrated the likely existence of signalling molecules or morphogens that control the pattern of development in the embryo. Now at last seems possible that some of these morphogens may have been identified. We review current evidence for the molecular basis of positional information. PMID:1768796

  6. Technical basis document for external events

    SciTech Connect

    OBERG, B.D.

    2003-03-22

    This document supports the Tank Farms Documented Safety Analysis and presents the technical basis for the frequencies of externally initiated accidents. The consequences of externally initiated events are discussed in other documents that correspond to the accident that was caused by the external event. The external events include aircraft crash, vehicle accident, range fire, and rail accident.

  7. The molecular basis of peanut allergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut allergens can trigger a potent and sometimes dangerous immune response in an increasing number of people. The molecular structures of these allergens form the basis for understanding this response. This review describes the currently known peanut allergen structures, and discusses how modif...

  8. 42 CFR 478.12 - Statutory basis.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Statutory basis. 478.12 Section 478.12 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) QUALITY IMPROVEMENT ORGANIZATIONS RECONSIDERATIONS AND APPEALS Utilization and Quality Control...

  9. 45 CFR 144.200 - Basis.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Basis. 144.200 Section 144.200 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS REQUIREMENTS RELATING TO... frequency with which such reports are to be made. This section of the statute also provides that...

  10. PRELIMINARY SELECTION OF MGR DESIGN BASIS EVENTS

    SciTech Connect

    J.A. Kappes

    1999-09-16

    The purpose of this analysis is to identify the preliminary design basis events (DBEs) for consideration in the design of the Monitored Geologic Repository (MGR). For external events and natural phenomena (e.g., earthquake), the objective is to identify those initiating events that the MGR will be designed to withstand. Design criteria will ensure that radiological release scenarios resulting from these initiating events are beyond design basis (i.e., have a scenario frequency less than once per million years). For internal (i.e., human-induced and random equipment failures) events, the objective is to identify credible event sequences that result in bounding radiological releases. These sequences will be used to establish the design basis criteria for MGR structures, systems, and components (SSCs) design basis criteria in order to prevent or mitigate radiological releases. The safety strategy presented in this analysis for preventing or mitigating DBEs is based on the preclosure safety strategy outlined in ''Strategy to Mitigate Preclosure Offsite Exposure'' (CRWMS M&O 1998f). DBE analysis is necessary to provide feedback and requirements to the design process, and also to demonstrate compliance with proposed 10 CFR 63 (Dyer 1999b) requirements. DBE analysis is also required to identify and classify the SSCs that are important to safety (ITS).