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Sample records for gas reduction scenarios

  1. A modeling comparison of deep greenhouse gas emissions reduction scenarios by 2030 in California

    DOE PAGES

    Yeh, Sonia; Yang, Christopher; Gibbs, Michael; ...

    2016-10-21

    California aims to reduce greenhouse gas (GHG) emissions to 40% below 1990 levels by 2030. We compare six energy models that have played various roles in informing the state policymakers in setting climate policy goals and targets. These models adopt a range of modeling structures, including stock-turnover back-casting models, a least-cost optimization model, macroeconomic/macro-econometric models, and an electricity dispatch model. Results from these models provide useful insights in terms of the transformations in the energy system required, including efficiency improvements in cars, trucks, and buildings, electrification of end-uses, low- or zero-carbon electricity and fuels, aggressive adoptions of zero-emission vehicles (ZEVs),more » demand reduction, and large reductions of non-energy GHG emissions. Some of these studies also suggest that the direct economic costs can be fairly modest or even generate net savings, while the indirect macroeconomic benefits are large, as shifts in employment and capital investments could have higher economic returns than conventional energy expenditures. These models, however, often assume perfect markets, perfect competition, and zero transaction costs. They also do not provide specific policy guidance on how these transformative changes can be achieved. Greater emphasis on modeling uncertainty, consumer behaviors, heterogeneity of impacts, and spatial modeling would further enhance policymakers' ability to design more effective and targeted policies. Here, this paper presents an example of how policymakers, energy system modelers and stakeholders interact and work together to develop and evaluate long-term state climate policy targets. Lastly, even though this paper focuses on California, the process of dialogue and interactions, modeling results, and lessons learned can be generally adopted across different regions and scales.« less

  2. A modeling comparison of deep greenhouse gas emissions reduction scenarios by 2030 in California

    SciTech Connect

    Yeh, Sonia; Yang, Christopher; Gibbs, Michael; Roland-Holst, David; Greenblatt, Jeffery; Mahone, Amber; Wei, Dan; Brinkman, Gregory; Cunningham, Joshua; Eggert, Anthony; Haley, Ben; Hart, Elaine; Williams, Jim

    2016-10-21

    California aims to reduce greenhouse gas (GHG) emissions to 40% below 1990 levels by 2030. We compare six energy models that have played various roles in informing the state policymakers in setting climate policy goals and targets. These models adopt a range of modeling structures, including stock-turnover back-casting models, a least-cost optimization model, macroeconomic/macro-econometric models, and an electricity dispatch model. Results from these models provide useful insights in terms of the transformations in the energy system required, including efficiency improvements in cars, trucks, and buildings, electrification of end-uses, low- or zero-carbon electricity and fuels, aggressive adoptions of zero-emission vehicles (ZEVs), demand reduction, and large reductions of non-energy GHG emissions. Some of these studies also suggest that the direct economic costs can be fairly modest or even generate net savings, while the indirect macroeconomic benefits are large, as shifts in employment and capital investments could have higher economic returns than conventional energy expenditures. These models, however, often assume perfect markets, perfect competition, and zero transaction costs. They also do not provide specific policy guidance on how these transformative changes can be achieved. Greater emphasis on modeling uncertainty, consumer behaviors, heterogeneity of impacts, and spatial modeling would further enhance policymakers' ability to design more effective and targeted policies. Here, this paper presents an example of how policymakers, energy system modelers and stakeholders interact and work together to develop and evaluate long-term state climate policy targets. Lastly, even though this paper focuses on California, the process of dialogue and interactions, modeling results, and lessons learned can be generally adopted across different regions and scales.

  3. Greenhouse Gas Mitigation Options in ISEEM Global Energy Model: 2010-2050 Scenario Analysis for Least-Cost Carbon Reduction in Iron and Steel Sector

    SciTech Connect

    Karali, Nihan; Xu, Tengfang; Sathaye, Jayant

    2013-12-01

    The goal of the modeling work carried out in this project was to quantify long-term scenarios for the future emission reduction potentials in the iron and steel sector. The main focus of the project is to examine the impacts of carbon reduction options in the U.S. iron and steel sector under a set of selected scenarios. In order to advance the understanding of carbon emission reduction potential on the national and global scales, and to evaluate the regional impacts of potential U.S. mitigation strategies (e.g., commodity and carbon trading), we also included and examined the carbon reduction scenarios in China’s and India’s iron and steel sectors in this project. For this purpose, a new bottom-up energy modeling framework, the Industrial Sector Energy Efficiency Modeling (ISEEM), (Karali et al. 2012) was used to provide detailed annual projections starting from 2010 through 2050. We used the ISEEM modeling framework to carry out detailed analysis, on a country-by-country basis, for the U.S., China’s, and India’s iron and steel sectors. The ISEEM model applicable to iron and steel section, called ISEEM-IS, is developed to estimate and evaluate carbon emissions scenarios under several alternative mitigation options - including policies (e.g., carbon caps), commodity trading, and carbon trading. The projections will help us to better understand emission reduction potentials with technological and economic implications. The database for input of ISEEM-IS model consists of data and information compiled from various resources such as World Steel Association (WSA), the U.S. Geological Survey (USGS), China Steel Year Books, India Bureau of Mines (IBM), Energy Information Administration (EIA), and recent LBNL studies on bottom-up techno-economic analysis of energy efficiency measures in the iron and steel sector of the U.S., China, and India, including long-term steel production in China. In the ISEEM-IS model, production technology and manufacturing details are

  4. Midwestern Greenhouse Gas Reduction Accord

    SciTech Connect

    2007-07-01

    The Midwestern Greenhouse Gas Reduction Acccord, or Midwestern Greenhouse gas Accord (MGA), is a regional agreement by governors of the states in the US Midwest and one Canadian province to reduce greenhouse gas emissions to combat climate change. Signatories to the accord include the US states of Minnesota, Wisconsin, Illinois, Indiana, Iowa, Michigan, Kansas, Ohio and South Dakota, and the Canadian Province of Manitoba. The accord, signed on November 15, 2007, established the Midwestern Greenhouse Gas Reduction Program, which aims to: establish greenhouse gas reduction targets and timeframes consistent with MGA member states' targets; develop a market-based and multi-sector cap-and-trade mechanism to help achieve those reduction targets; establish a system to enable tracking, management, and crediting for entities that reduce greenhouse gas emissions; and develop and implement additional steps as needed to achieve the reduction targets, such as a low-carbon fuel standards and regional incentives and funding mechanisms. The GHG registry will be managed by the Climate Registry, which manages the registry for other US state schemes. One of the first actions was to convene an Energy Security under Climate Stewardship Platform to guide future development of the Midwest's energy economy.

  5. Natural gas network resiliency to a "shakeout scenario" earthquake.

    SciTech Connect

    Ellison, James F.; Corbet, Thomas Frank,; Brooks, Robert E.

    2013-06-01

    A natural gas network model was used to assess the likely impact of a scenario San Andreas Fault earthquake on the natural gas network. Two disruption scenarios were examined. The more extensive damage scenario assumes the disruption of all three major corridors bringing gas into southern California. If withdrawals from the Aliso Canyon storage facility are limited to keep the amount of stored gas within historical levels, the disruption reduces Los Angeles Basin gas supplies by 50%. If Aliso Canyon withdrawals are only constrained by the physical capacity of the storage system to withdraw gas, the shortfall is reduced to 25%. This result suggests that it is important for stakeholders to put agreements in place facilitating the withdrawal of Aliso Canyon gas in the event of an emergency.

  6. Greenhouse Gas Reductions: SF6

    ScienceCinema

    Anderson, Diana

    2016-07-12

    Argonne National Laboratory is leading the way in greenhouse gas reductions, particularly with the recapture and recycling of sulfur hexafluoride (SF6). SF6 is a gas used in industry as an anti-arcing agent. It is an extremely potent greenhouse gas — one pound of SF6 is equivalent to 12 tons of carbon dioxide. While the U.S. does not currently regulate SF6 emissions, Argonne is proactively and voluntarily recovering and recycling to reduce SF6 emissions. Argonne saves over 16,000 tons of SF6 from being emitted into the atmosphere each year, and by recycling the gas rather than purchasing it new, we save taxpayers over $208,000 each year.

  7. Strategies for cost-effective carbon reductions: A sensitivity analysis of alternative scenarios

    SciTech Connect

    Gumerman, Etan; Koomey, Jonathan G.; Brown, Marilyn

    2001-07-11

    Analyses of alternative futures often present results for a limited set of scenarios, with little if any sensitivity analysis to identify the factors affecting the scenario results. This approach creates an artificial impression of certainty associated with the scenarios considered, and inhibits understanding of the underlying forces. This paper summarizes the economic and carbon savings sensitivity analysis completed for the Scenarios for a Clean Energy Future study (IWG, 2000). Its 19 sensitivity cases provide insight into the costs and carbon-reduction impacts of a carbon permit trading system, demand-side efficiency programs, and supply-side policies. Impacts under different natural gas and oil price trajectories are also examined. The results provide compelling evidence that policy opportunities exist to reduce carbon emissions and save society money.

  8. The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Ross, Stephanie; Jones, Lucile

    2013-01-01

    The Science Application for Risk Reduction (SAFRR) tsunami scenario depicts a hypothetical but plausible tsunami created by an earthquake offshore from the Alaska Peninsula and its impacts on the California coast. The tsunami scenario is a collaboration between the U.S. Geological Survey (USGS), the California Geological Survey (CGS), the California Governor’s Office of Emergency Services (Cal OES), the National Oceanic and Atmospheric Administration (NOAA), other Federal, State, County, and local agencies, private companies, and academic and other institutions. This document presents evidence for past tsunamis, the scientific basis for the source, likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental and ecological impacts, social vulnerability, emergency management and evacuation challenges, and policy implications for California associated with this hypothetical tsunami. We also discuss ongoing mitigation efforts by the State of California and new communication products. The intended users are those who need to make mitigation decisions before future tsunamis, and those who will need to make rapid decisions during tsunami events. The results of the tsunami scenario will help managers understand the context and consequences of their decisions and how they may improve preparedness and response. An evaluation component will assess the effectiveness of the scenario process for target stakeholders in a separate report to improve similar efforts in the future.

  9. Impact of greenhouse gas emissions reduction in Indonesia: NO2

    NASA Astrophysics Data System (ADS)

    Susandi, A.

    2004-12-01

    In this study, we develop scenarios of total air pollution from fossil fuel consumption and its impacts for the 21st century, using an inter-temporal general equilibrium model MERGE. The Model for Evaluating the Regional and Global Effects of greenhouse gas reduction policies (MERGE) is used to project energy consumption and production. We use the base scenarios from IPCC (2000). These scenarios assume that no measures are undertaken to control greenhouse gas emissions. We extend the IPCC scenarios with mitigation scenarios, estimating the air pollution impacts of greenhouse gas emission reduction. The MERGE model was extended to analyze emissions of nitrogen dioxide (NO2), their concentrations, impacts on human health, and economic valuation. To estimate of nitrogen dioxide (NO2) impacts on respiratory symptoms, we calculated the NO2 concentration as derived from nitrogen oxide (NOx). In the baseline scenario, the concentrations of NO2 are rising to 2,263 μg/m3 in 2100. If the Organisation for Economic Co-operation and Development (OECD) countries reduce their emissions, respiratory symptoms among adult's associated with NO2 case would reach the highest to 65,741% of adult population cases by the end of century. If all countries reduce their emission in the future, the total health problem cost associated with NO2 will lower 35% of GDP than in the baseline scenario during the century.

  10. Quantification of the Potential Gross Economic Impacts of Five Methane Reduction Scenarios

    SciTech Connect

    Keyser, David; Warner, Ethan; Curley, Christina

    2015-04-23

    Methane (CH4) is a potent greenhouse gas that is released from the natural gas supply chain into the atmosphere as a result of fugitive emissions1 and venting2 . We assess five potential CH4 reduction scenarios from transmission, storage, and distribution (TS&D) using published literature on the costs and the estimated quantity of CH4 reduced. We utilize cost and methane inventory data from ICF (2014) and Warner et al. (forthcoming) as well as data from Barrett and McCulloch (2014) and the American Gas Association (AGA) (2013) to estimate that the implementation of these measures could support approximately 85,000 jobs annually from 2015 to 2019 and reduce CH4 emissions from natural gas TS&D by over 40%. Based on standard input/output analysis methodology, measures are estimated to support over $8 billion in GDP annually over the same time period and allow producers to recover approximately $912 million annually in captured gas.

  11. Technology and Greenhouse Gas Emissions: An IntegratedScenario Analysis

    SciTech Connect

    Koomey, J.G.; Latiner, S.; Markel, R.J.; Marnay, C.; Richey, R.C.

    1998-09-01

    This report describes an analysis of possible technology-based scenarios for the U.S. energy system that would result in both carbon savings and net economic benefits. We use a modified version of the Energy Information Administration's National Energy Modeling System (LBNL-NEMS) to assess the potential energy, carbon, and bill savings from a portfolio of carbon saving options. This analysis is based on technology resource potentials estimated in previous bottom-up studies, but it uses the integrated LBNL-NEMS framework to assess interactions and synergies among these options. The analysis in this paper builds on previous estimates of possible "technology paths" to investigate four major components of an aggressive greenhouse gas reduction strategy: (1) the large scale implementation of demand-side efficiency, comparable in scale to that presented in two recent policy studies on this topic; (2) a variety of "alternative" electricity supply-side options, including biomass cofiring, extension of the renewable production tax credit for wind, increased industrial cogeneration, and hydropower refurbishment. (3) the economic retirement of older and less efficient existing fossil-find power plants; and (4) a permit charge of $23 per metric ton of carbon (1996 $/t),l assuming that carbon trading is implemented in the US, and that the carbon permit charge equilibrates at this level. This level of carbon permit charge, as discussed later in the report, is in the likely range for the Clinton Administration's position on this topic.

  12. Application of dispersion modeling to indoor gas release scenarios.

    PubMed

    Rasouli, F; Williams, T A

    1995-03-01

    Many complex models are available to study the dispersion of contaminants or ventilation effectiveness in indoor spaces. Because of the computationally complex numerical schemes employed, most of these models require mainframe computers or workstations. However, simple design tools or guidelines are needed, in addition to complicated models. A dispersion model based on the basic governing equations was developed and uses an analytical solution. Because the concentration is expressed by an analytical solution, the grid size and time steps are user definable. A computer program was used to obtain numerical results and to obtain release history from a thermodynamic source model. The model can be used to estimate three-dimensional spatial and temporal variations in concentrations resulting from transient gas releases in an enclosure. The model was used to study a gas release scenario from a pressurized cylinder into a large ventilated building, in this case, a transit parking and fueling facility.

  13. Advancing Greenhouse Gas Reductions through Affordable Housing

    EPA Pesticide Factsheets

    James City County, Virginia, is an EPA Climate Showcase Community. EPA’s Climate Showcase Communities Program helps local governments and tribal nations pilot innovative, cost-effective and replicable community-based greenhouse gas reduction projects.

  14. Non-Profit Greenhouse Gas Reductions Program

    EPA Pesticide Factsheets

    Baltimore City, Maryland, is an EPA Climate Showcase Community. EPA’s Climate Showcase Communities Program helps local governments and tribal nations pilot innovative, cost-effective and replicable community-based greenhouse gas reduction projects.

  15. Greenhouse Gas Reductions for Marginalized Communities

    EPA Pesticide Factsheets

    Honolulu, Hawaii, is an EPA Climate Showcase Community. EPA’s Climate Showcase Communities Program helps local governments and tribal nations pilot innovative, cost-effective and replicable community-based greenhouse gas reduction projects.

  16. Modified Chaplygin gas inspired inflationary model in braneworld scenario

    NASA Astrophysics Data System (ADS)

    Jawad, Abdul; Rani, Shamaila; Mohsaneen, Sidra

    2016-05-01

    We investigate the modified Chaplygin gas inspired inflationary regime in the brane-world framework in the presence of standard and tachyon scalar fields. We consider the intermediate inflationary scenario and construct the slow-roll parameters, e-folding numbers, spectral index, scalar and tensor power spectra, tensor to scalar ratio for both scalar field models. We develop the ns - N and r - N planes and concluded that ns˜eq96^{+0.5}_{-0.5} and r≤0.0016 for N˜eq60^{+5}_{-5} in both cases of scalar field models as well as for all values of m. These constraints are consistent with observational data such as WMAP7, WMAP9 and Planck data.

  17. Bibliography of greenhouse-gas reduction strategies

    SciTech Connect

    Tompkins, M.M.; Mintz, M.M.

    1995-03-01

    A bibliography of greenhouse-gas reduction strategies has been compiled to assist the Climate change Action Plan Task Force in their consideration of strategies to reduce greenhouse-gas emissions from personal motor vehicles. The document contains a summary of the literature, including it major directions and implications; and annotated listing of 32 recent pertinent documents; and a listing of a larger group of related reports.

  18. Train noise reduction scenarios for compliance with future noise legislation

    NASA Astrophysics Data System (ADS)

    Leth, S.

    2003-10-01

    The Technical Specification for Interoperability (TSI) for high-speed trains on the European market includes limits on noise emission. These and other future restrictions on exterior noise of high-speed and intercity trains will require that train manufacturers implement noise control measures early in the design phase. A fundamental problem faced by manufacturers during the design process is determining how much noise reduction is required for each of the various noise sources on the train in order to achieve an optimal balance. To illustrate this process, estimates are presented of the contributions from different sources on existing Bombardier trains, based on measured data, numerical calculations and empirical formulae. In addition, methods of achieving the required noise reductions for different sources are briefly discussed along with targets for future exterior noise emission. Measurement results presented demonstrate the importance of track quality in noise emission. Noise restrictions, including future legislation, must give proper recognition to this important parameter.

  19. Scenarios for exercising technical approaches to verified nuclear reductions

    SciTech Connect

    Doyle, James

    2010-01-01

    Presidents Obama and Medvedev in April 2009 committed to a continuing process of step-by-step nuclear arms reductions beyond the new START treaty that was signed April 8, 2010 and to the eventual goal of a world free of nuclear weapons. In addition, the US Nuclear Posture review released April 6, 2010 commits the US to initiate a comprehensive national research and development program to support continued progress toward a world free of nuclear weapons, including expanded work on verification technologies and the development of transparency measures. It is impossible to predict the specific directions that US-RU nuclear arms reductions will take over the 5-10 years. Additional bilateral treaties could be reached requiring effective verification as indicated by statements made by the Obama administration. There could also be transparency agreements or other initiatives (unilateral, bilateral or multilateral) that require monitoring with a standard of verification lower than formal arms control, but still needing to establish confidence to domestic, bilateral and multilateral audiences that declared actions are implemented. The US Nuclear Posture Review and other statements give some indication of the kinds of actions and declarations that may need to be confirmed in a bilateral or multilateral setting. Several new elements of the nuclear arsenals could be directly limited. For example, it is likely that both strategic and nonstrategic nuclear warheads (deployed and in storage), warhead components, and aggregate stocks of such items could be accountable under a future treaty or transparency agreement. In addition, new initiatives or agreements may require the verified dismantlement of a certain number of nuclear warheads over a specified time period. Eventually procedures for confirming the elimination of nuclear warheads, components and fissile materials from military stocks will need to be established. This paper is intended to provide useful background information

  20. Scenario analysis to vehicular emission reduction in Beijing-Tianjin-Hebei (BTH) region, China.

    PubMed

    Guo, Xiurui; Fu, Liwei; Ji, Muse; Lang, Jianlei; Chen, Dongsheng; Cheng, Shuiyuan

    2016-09-01

    Motor vehicle emissions are increasingly becoming one of the important factors affecting the urban air quality in China. It is necessary and useful to policy makers to demonstrate the situation given the relevant pollutants reduction measures are taken. This paper predicted the reduction potentials of conventional pollutants (PM10, NOx, CO, HC) under different control strategies and policies in the Beijing-Tianjin-Hebei (BTH) region during 2011-2020. There are the baseline and 5 control scenarios designed, which presented the different current and future possible vehicular emissions control measures. Future population of different kinds of vehicles were predicted based on the Gompertz model, and vehicle kilometers travelled estimated as well. After that, the emissions reduction under the different scenarios during 2011-2020 could be estimated using emission factors and activity level data. The results showed that, the vehicle population in the BTH region would continue to grow up, especially in Tianjin and Hebei. Comparing the different scenarios, emission standards updating scenario would achieve a substantial reduction and keep rising up for all the pollutants, and the scenario of eliminating high-emission vehicles can reduce emissions more effectively in short-term than in long-term, especially in Beijing. Due to the constraints of existing economical and technical level, the reduction effect of promoting new energy vehicles would not be significant, especially given the consideration of their lifetime impact. The reduction effect of population regulation scenario in Beijing cannot be ignorable and would keep going up for PM10, CO and HC, excluding NOx. Under the integrated scenario considering all the control measures it would achieve the maximum reduction potential of emissions, which means to reduce emissions of PM10, NOx, CO, HC, by 56%, 59%, 48%, 52%, respectively, compared to BAU scenario for the whole BTH region in 2020.

  1. SAFRR (Science Application for Risk Reduction) Tsunami Scenario--Executive Summary and Introduction: Chapter A in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Ross, Stephanie L.; Jones, Lucile M.; Miller, Kevin H.; Porter, Keith A.; Wein, Anne; Wilson, Rick I.; Bahng, Bohyun; Barberopoulou, Aggeliki; Borrero, Jose C.; Brosnan, Deborah M.; Bwarie, John T.; Geist, Eric L.; Johnson, Laurie A.; Kirby, Stephen H.; Knight, William R.; Long, Kate; Lynett, Patrick; Mortensen, Carl E.; Nicolsky, Dmitry J.; Perry, Suzanne C.; Plumlee, Geoffrey S.; Real, Charles R.; Ryan, Kenneth; Suleimani, Elena; Thio, Hong Kie; Titov, Vasily V.; Whitmore, Paul M.; Wood, Nathan J.

    2013-01-01

    The Science Application for Risk Reduction (SAFRR) tsunami scenario depicts a hypothetical but plausible tsunami created by an earthquake offshore from the Alaska Peninsula and its impacts on the California coast. The tsunami scenario is a collaboration between the U.S. Geological Survey (USGS), the California Geological Survey, the California Governor’s Office of Emergency Services (Cal OES), the National Oceanic and Atmospheric Administration (NOAA), other Federal, State, County, and local agencies, private companies, and academic and other institutions. This document presents evidence for past tsunamis, the scientific basis for the source, likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental and ecological impacts, social vulnerability, emergency management and evacuation challenges, and policy implications for California associated with this hypothetical tsunami. We also discuss ongoing mitigation efforts by the State of California and new communication products. The intended users are those who need to make mitigation decisions before future tsunamis, and those who will need to make rapid decisions during tsunami events. The results of the tsunami scenario will help managers understand the context and consequences of their decisions and how they may improve preparedness and response. An evaluation component will assess the effectiveness of the scenario process for target stakeholders in a separate report to improve similar efforts in the future.

  2. Detection and Appraisal of Gas Hydrates: Indian Scenario

    NASA Astrophysics Data System (ADS)

    Sain, K.

    2009-04-01

    Gas hydrates, found in shallow sediments of permafrost and outer continental margins, are crystalline form of methane and water. The carbon within global gas hydrates is estimated two times the carbon contained in world-wide fossil fuels. It is also predicted that 15% recovery of gas hydrates can meet the global energy requirement for the next 200 years. Several parameters like bathymetry, seafloor temperature, sediment thickness, rate of sedimentation and total organic carbon content indicate very good prospect of gas hydrates in the vast offshore regions of India. Methane stored in the form of gas hydrates within the Indian exclusive economic zone is estimated to be few hundred times the country's conventional gas reserve. India produces less than one-third of her oil requirement and gas hydrates provide great hopes as a viable source of energy in the 21st century. Thus identification and quantitative assessment of gas hydrates are very important. By scrutiny and reanalysis of available surface seismic data, signatures of gas hydrates have been found out in the Kerala-Konkan and Saurashtra basins in the western margin, and Krishna-Godavari, Mahanadi and Andaman regions in the eastern margin of India by mapping the bottom simulating reflector or BSR based on its characteristic features. In fact, the coring and drilling in 2006 by the Indian National Gas Hydrate Program have established the ground truth in the eastern margin. It has become all the more important now to identify further prospective regions with or without BSR; demarcate the lateral/areal extent of gas hydrate-bearing sediments and evaluate their resource potential in both margins of India. We have developed various approaches based on seismic traveltime tomography; waveform inversion; amplitude versus offset (AVO) modeling; AVO attributes; seismic attributes and rock physics modeling for the detection, delineation and quantification of gas-hydrates. The blanking, reflection strength, instantaneous

  3. Advancing Development and Greenhouse Gas Reductions in Vietnam's Wind Sector

    SciTech Connect

    Bilello, D.; Katz, J.; Esterly, S.; Ogonowski, M.

    2014-09-01

    Clean energy development is a key component of Vietnam's Green Growth Strategy, which establishes a target to reduce greenhouse gas (GHG) emissions from domestic energy activities by 20-30 percent by 2030 relative to a business-as-usual scenario. Vietnam has significant wind energy resources, which, if developed, could help the country reach this target while providing ancillary economic, social, and environmental benefits. Given Vietnam's ambitious clean energy goals and the relatively nascent state of wind energy development in the country, this paper seeks to fulfill two primary objectives: to distill timely and useful information to provincial-level planners, analysts, and project developers as they evaluate opportunities to develop local wind resources; and, to provide insights to policymakers on how coordinated efforts may help advance large-scale wind development, deliver near-term GHG emission reductions, and promote national objectives in the context of a low emission development framework.

  4. Variable modified Chaplygin gas in the holographic dark energy scenario

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Surajit; Debnath, Ujjal

    2012-07-01

    The holographic principle emerged in the context of black-holes, where it was noted that a local quantum field theory can not fully describe the black holes [1]. Some long standing debates regarding the time evolution of a system, where a black hole forms and then evaporates, played the key role in the development of the holographic principle [2,3,4]. The Chaplygin gas is characterized by an exotic equation of state p=-B/ρ. where B is a positive constant. Role of Chaplygin gas in the accelerated universe has been studied by several authors. The above mentioned equation of state has been modified to p=-B/ρ^{α}, where α lies between 0 and 1. This equation has been further modified to p=-A+B/ρ^{α}. This is called the modified Chaplygin gas. Debnath [5] introduced a variable modified Chaplygin gas by considering B as a function of scale factor a. In this work, we have considered that the universe is filled with normal matter and variable modified Chaplygin gas. Also we have considered the interaction between normal matter and variable modified Chaplygin gas in FRW universe. Then we have considered a correspondence between the holographic dark energy density and interacting variable modified Chaplygin gas energy density. Then we have reconstructed the potential of the scalar field which describes the variable modified Chaplygin cosmology References: [1] K. Enqvist, S. Hannested and M. S. Sloth, JCAP 2, 004 (2005). [2] L. Thorlocius, hep-th/0404098. [3] G. T. Hooft, gr-qc/9310026. [4] L. Susskind, J. Math. Phys. 36, 6377 (1995). [5] U. Debnath, Astrophys. Space Sci. 312, 295 (2007).

  5. Lifecycle greenhouse gas implications of US national scenarios for cellulosic ethanol production

    NASA Astrophysics Data System (ADS)

    Scown, Corinne D.; Nazaroff, William W.; Mishra, Umakant; Strogen, Bret; Lobscheid, Agnes B.; Masanet, Eric; Santero, Nicholas J.; Horvath, Arpad; McKone, Thomas E.

    2012-03-01

    The Energy Independence and Security Act of 2007 set an annual US national production goal of 39.7 billion l of cellulosic ethanol by 2020. This paper explores the possibility of meeting that target by growing and processing Miscanthus × giganteus. We define and assess six production scenarios in which active cropland and/or Conservation Reserve Program land are used to grow to Miscanthus. The crop and biorefinery locations are chosen with consideration of economic, land-use, water management and greenhouse gas (GHG) emissions reduction objectives. Using lifecycle assessment, the net GHG footprint of each scenario is evaluated, providing insight into the climate costs and benefits associated with each scenario’s objectives. Assuming that indirect land-use change is successfully minimized or mitigated, the results suggest two major drivers for overall GHG impact of cellulosic ethanol from Miscanthus: (a) net soil carbon sequestration or emissions during Miscanthus cultivation and (b) GHG offset credits for electricity exported by biorefineries to the grid. Without these factors, the GHG intensity of bioethanol from Miscanthus is calculated to be 11-13 g CO2-equivalent per MJ of fuel, which is 80-90% lower than gasoline. Including soil carbon sequestration and the power-offset credit results in net GHG sequestration up to 26 g CO2-equivalent per MJ of fuel.

  6. Prospects for a nicotine-reduction strategy in the cigarette endgame: Alternative tobacco harm reduction scenarios.

    PubMed

    Kozlowski, Lynn T

    2015-06-01

    Some major national and international tobacco control organisations favour mandating a reduction in nicotine content of cigarettes to non-addictive levels as a tobacco control tool. Reducing nicotine content, it is argued, will make tobacco smoking less attractive. The 2009 U.S. Food and Drug Administration's regulation of cigarettes appears to have the power to reduce nicotine to non-addictive levels provided it is not taken to zero. A consideration of the U.S. context, however, raises doubts about (a) whether this will ever be practicable and (b), if practicable, how long it will take to implement. Current versions of the nicotine-reducing strategy propose the systematic, incentivised use of less harmful nicotine/tobacco products as elements of the mandatory cigarette nicotine-reduction strategy. Time will tell if and when mandatory nicotine reduction in tobacco cigarettes will occur and what impact it might have on smoking prevalence. The question posed here is "Why wait?" Resources used in implementing reduction in nicotine content have an opportunity cost. In the meantime, nicotine-maintaining harm reduction strategies can have nearer term effects on tobacco use as an individual and a public health issue.

  7. Mortality, greenhouse gas emissions and consumer cost impacts of combined diet and physical activity scenarios: a health impact assessment study

    PubMed Central

    Monsivais, Pablo; Jones, Nicholas RV; Brand, Christian; Woodcock, James

    2017-01-01

    Objective To quantify changes in mortality, greenhouse gas (GHG) emissions and consumer costs for physical activity and diet scenarios. Design For the physical activity scenarios, all car trips from <1 to <8 miles long were progressively replaced with cycling. For the diet scenarios, the study population was assumed to increase fruit and vegetable (F&V) consumption by 1–5 portions of F&V per day, or to eat at least 5 portions per day. Health effects were modelled with the comparative risk assessment method. Consumer costs were based on fuel cost savings and average costs of F&V, and GHG emissions to fuel usage and F&V production. Setting Working age population for England. Participants Data from the Health Survey for England, National Travel Survey and National Diet and Nutrition Survey. Primary outcomes measured Changes in premature deaths, consumer costs and GHG emissions stratified by age, gender and socioeconomic status (SES). Results Premature deaths were reduced by between 75 and 7648 cases per year for the physical activity scenarios, and 3255 and 6187 cases per year for the diet scenarios. Mortality reductions were greater among people of medium and high SES in the physical activity scenarios, whereas people with lower SES benefited more in the diet scenarios. Similarly, transport fuel costs fell more for people of high SES, whereas diet costs increased most for the lowest SES group. Net GHG emissions decreased by between 0.2 and 10.6 million tons of carbon dioxide equivalent (MtCO2e) per year for the physical activity scenarios and increased by between 1.3 and 6.3 MtCO2e/year for the diet scenarios. Conclusions Increasing F&V consumption offers the potential for large health benefits and reduces health inequalities. Replacing short car trips with cycling offers the potential for net benefits for health, GHG emissions and consumer costs.

  8. Recent observational constraints on generalized Chaplygin gas in UDME scenario

    NASA Astrophysics Data System (ADS)

    Thakur, P.

    2017-03-01

    Recent observational predictions suggest that our Universe is passing through an accelerating phase in the recent past. This acceleration may be realized with the negatively pressured dark energy. Generalized Chaplygin gas may be suitable to describe the evolution of the Universe as a candidate of unified dark matter energy (UDME) model. Its EoS parameters are constrained using (i) dimensionless age parameter ( H 0 t 0) and (ii) the observed Hubble ( H( z)- z) data (OHD) + baryon acoustic oscillation (BAO) data + cosmic microwave background (CMB) shift data + supernovae (Union2.1) data. Dimensionless age parameter puts loose bounds on the EoS parameters. Best-fit values of the EoS parameters H 0, A s and α ( A s and α are defined in the energy density for generalized Chaplygin gas (GCG) and in EoS) are then determined from OHD + BAO + CMB + Union2.1 data and contours are drawn to obtain their allowed range of values. The present age of the Universe ( t 0) and the present Hubble parameter ( H 0) have been estimated with 1 σ confidence level. Best-fit values of deceleration parameter ( q), squared sound speed (cs2) and EoS parameter ( ω) of this model are then determined. It is seen that GCG satisfactorily accommodates an accelerating phase and structure formation phase.

  9. Emissions from residential combustion considering end-uses and spatial constraints: Part II, emission reduction scenarios

    NASA Astrophysics Data System (ADS)

    Winijkul, Ekbordin; Bond, Tami C.

    2016-01-01

    Cooking, heating, and other activities in the residential sector are major sources of indoor and outdoor air pollution, especially when solid fuels are used to provide energy. Because of their deleterious effects on the atmosphere and human health, multinational strategies to reduce emissions have been proposed. This study examines the effects of some possible policies, considering realistic factors that constrain mitigation: end-uses, spatial constraints involving proximity to forest or electricity, existing technology, and assumptions about user behavior. Reduction scenarios are applied to a year-2010, spatially distributed baseline of emissions of particulate matter, black carbon, organic carbon, nitrogen oxides, methane, non-methane hydrocarbons, carbon monoxide, and carbon dioxide. Scenarios explored are: (1) cleanest current stove, where we assume that existing technology in each land type is applied to burn existing fuels; (2) stove standards, where we assume that stoves are designed to meet performance standards; and (3) clean fuels, where users adopt the cleanest fuels plausible in each land type. We assume that people living in forest access areas continue to use wood regardless of available fuels, so the clean-fuels scenario leads to a reduction in emissions of 18-25%, depending on the pollutant, across the study region. Cleaner stoves preferentially affect land types with forest access, where about half of the fuel is used; emission reductions range from 25 to 82%, depending on the pollutant. If stove performance standards can be met, particulate matter emissions are reduced by 62% for the loosest standards and 95% for the tightest standards, and carbon monoxide is reduced by 40% and 62% for the loosest and tightest standards. Reductions in specific regions and countries depend on the existing fuel mixture and the population division among land types, and are explored for Latin America, Africa, East Asia, South Asia, and Southeast Asia.

  10. Scenario analysis for nutrient emission reduction in the European inland waters

    NASA Astrophysics Data System (ADS)

    Bouraoui, F.; Thieu, V.; Grizzetti, B.; Britz, W.; Bidoglio, G.

    2014-12-01

    Despite a large body of legislation, high nutrient loads are still emitted in European inland waters. In the present study we evaluate a set of alternative scenarios aiming at reducing nitrogen and phosphorus emissions from anthropogenic activities to all European Seas. In particular, we tested the full implementation of the European Urban Waste Water Directive, which controls emissions from point source. In addition, we associated the full implementation of this Directive with a ban of phosphorus-based laundry detergents. Then we tested two human diet scenarios and their impacts on nutrient emissions. We also developed a scenario based on an optimal use of organic manure. The impacts of all our scenarios were evaluated using a statistical model of nitrogen and phosphorus fate (GREEN) linked to an agro-economic model (CAPRI). We show that the ban of phosphorus-based laundry detergents coupled with the full implementation of the Urban Waste Water Directive is the most effective approach for reducing phosphorus emissions from human based activities. Concerning nitrogen, the highest reductions are obtained with the optimized use of organic manure.

  11. Energy, greenhouse gas, and cost reductions for municipal recycling systems.

    PubMed

    Chester, Mikhail; Martin, Elliot; Sathaye, Nakul

    2008-03-15

    Curbside recycling programs can be more cost-effective than landfilling and lead to environmental benefits from the recovery of materials. Significant reductions in energy and emissions are derived from the decrease of energy-intensive production with virgin materials. In many cities, competing priorities can lead to limited consideration given to system optimal collection and processing strategies that can drive down costs and increase revenue while simultaneously reducing system energy consumption and greenhouse gas (GHG) emissions. We evaluate three alterations to a hypothetical California city's recycling network to discern the conditions under which the changes.constitute system improvements to cost, energy, and emissions. The system initially operates with a collection zoning scheme that does not mitigate the impact of seasonal variations in consumer tonnage. In addition, two collection organizations operate redundantly, collecting recyclables from different customer types on the same street network. Finally, the system is dual stream, meaning recyclables are separated at the curbside. In some scenarios, this practice can limit the consumer participation rate leading to lower collection quantities. First, we evaluate a "business as usual" (BAU) scenario and find that the system operates at a $1.7 M/yr loss but still avoids a net 18.7 GJ and 1700 kg of greenhouse gas equivalent (GGE) per ton of material recycled. Second, we apply an alternative zoning scheme for collection that creates a uniform daily pickup demand throughout the year reducing costs by $0.2 M/yr, energy by 30 MJ/ton, and GHG emissions by 2 kg GGE/ton. Next, the two collection organizations are consolidated into a single entity further reducing vehicle fleet size and weekly vehicle miles traveled resulting in savings from BAU of $0.3 M/yr, 100 MJ/ton, and 8 kg GGE/ton. Lastly, we evaluate a switch to a single-stream system (where recyclables are commingled). We showthat single-stream recycling

  12. Alaska earthquake source for the SAFRR tsunami scenario: Chapter B in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Kirby, Stephen; Scholl, David; von Huene, Roland; Wells, Ray

    2013-01-01

    Tsunami modeling has shown that tsunami sources located along the Alaska Peninsula segment of the Aleutian-Alaska subduction zone have the greatest impacts on southern California shorelines by raising the highest tsunami waves for a given source seismic moment. The most probable sector for a Mw ~ 9 source within this subduction segment is between Kodiak Island and the Shumagin Islands in what we call the Semidi subduction sector; these bounds represent the southwestern limit of the 1964 Mw 9.2 Alaska earthquake rupture and the northeastern edge of the Shumagin sector that recent Global Positioning System (GPS) observations indicate is currently creeping. Geological and geophysical features in the Semidi sector that are thought to be relevant to the potential for large magnitude, long-rupture-runout interplate thrust earthquakes are remarkably similar to those in northeastern Japan, where the destructive Mw 9.1 tsunamigenic earthquake of 11 March 2011 occurred. In this report we propose and justify the selection of a tsunami source seaward of the Alaska Peninsula for use in the Tsunami Scenario that is part of the U.S. Geological Survey (USGS) Science Application for Risk Reduction (SAFRR) Project. This tsunami source should have the potential to raise damaging tsunami waves on the California coast, especially at the ports of Los Angeles and Long Beach. Accordingly, we have summarized and abstracted slip distribution from the source literature on the 2011 event, the best characterized for any subduction earthquake, and applied this synoptic slip distribution to the similar megathrust geometry of the Semidi sector. The resulting slip model has an average slip of 18.6 m and a moment magnitude of Mw = 9.1. The 2011 Tohoku earthquake was not anticipated, despite Japan having the best seismic and geodetic networks in the world and the best historical record in the world over the past 1,500 years. What was lacking was adequate paleogeologic data on prehistoric earthquakes

  13. Low-Carbon Watershed Management: Potential of Greenhouse Gas Reductions from Wastewater Treatment in Rural Vietnam

    PubMed Central

    Mohan, Geetha; Jian, Pu; Takemoto, Kazuhiko; Fukushi, Kensuke

    2016-01-01

    Currently in many cities and rural areas of Vietnam, wastewater is discharged to the environment without any treatment, which emits considerable amount of greenhouse gas (GHG), particularly methane. In this study, four GHG emission scenarios were examined, as well as the baseline scenario, in order to verify the potential of GHG reduction from domestic wastewater with adequate treatment facilities. The ArcGIS and ArcHydro tools were employed to visualize and analyze GHG emissions resulting from discharge of untreated wastewater, in rural areas of Vu Gia Thu Bon river basin, Vietnam. By applying the current IPCC guidelines for GHG emissions, we found that a reduction of GHG emissions can be achieved through treatment of domestic wastewater in the studied area. Compared with baseline scenario, a maximum 16% of total GHG emissions can be reduced, in which 30% of households existing latrines are substituted by Japanese Johkasou technology and other 20% of domestic wastewater is treated by conventional activated sludge. PMID:27699202

  14. Transformative Reduction of Transportation Greenhouse Gas Emissions. Opportunities for Change in Technologies and Systems

    SciTech Connect

    Vimmerstedt, Laura; Brown, Austin; Newes, Emily; Markel, Tony; Schroeder, Alex; Zhang, Yimin; Chipman, Peter; Johnson, Shawn

    2015-04-30

    The transportation sector is changing, influenced by concurrent, ongoing, dynamic trends that could dramatically affect the future energy landscape, including effects on the potential for greenhouse gas emissions reductions. Battery cost reductions and improved performance coupled with a growing number of electric vehicle model offerings are enabling greater battery electric vehicle market penetration, and advances in fuel cell technology and decreases in hydrogen production costs are leading to initial fuel cell vehicle offerings. Radically more efficient vehicles based on both conventional and new drivetrain technologies reduce greenhouse gas emissions per vehicle-mile. Net impacts also depend on the energy sources used for propulsion, and these are changing with increased use of renewable energy and unconventional fossil fuel resources. Connected and automated vehicles are emerging for personal and freight transportation systems and could increase use of low- or non-emitting technologies and systems; however, the net effects of automation on greenhouse gas emissions are uncertain. The longstanding trend of an annual increase in transportation demand has reversed for personal vehicle miles traveled in recent years, demonstrating the possibility of lower-travel future scenarios. Finally, advanced biofuel pathways have continued to develop, highlighting low-carbon and in some cases carbon-negative fuel pathways. We discuss the potential for transformative reductions in petroleum use and greenhouse gas emissions through these emerging transportation-sector technologies and trends and present a Clean Transportation Sector Initiative scenario for such reductions, which are summarized in Table ES-1.

  15. Maximizing Greenhouse Gas Emissions Reductions through Food Waste Diversion

    EPA Pesticide Factsheets

    Humboldt County, California, is an EPA Climate Showcase Community. EPA’s Climate Showcase Communities Program helps local governments and tribal nations pilot innovative, cost-effective and replicable community-based greenhouse gas reduction projects.

  16. Combined Effects of Nutrient Load Reduction and Climate Scenarios for the Baltic Sea Basin

    NASA Astrophysics Data System (ADS)

    Donnelly, Chantal; Strömqvist, Johan; Dahné, Joel; Arheimer, Berit

    2010-05-01

    A Baltic Sea Action Plan was approved in 2007 by the countries surrounding the Baltic Sea to improve the ecological status of this sea. An important part of this plan is reduction of nutrient inflows from the Baltic Sea basin into the sea. Required nutrient reductions have been apportioned to the countries within the basin and these countries are now planning the remedial measures required to meet the plan's requirements. An important factor that remains to be considered, however, is how well the planned nutrient reductions improve nutrient inflows into the Baltic Sea in a changed future climate. A high resolution, process based hydrological and nutrient flux model was set up for the entire Baltic Sea catchment area using the HYPE (Hydrological Predictions for the Environment) model. The HYPE model introduces the ability to model detailed hydrological processes at high resolution simultaneously and homogenously across many river basins. When using a modelling tool to assess water resources and their quality for a basin entailing several political entities, it is an advantage that the methods and data used are homogenous across such political boundaries. Readily available, regional and global databases were used to set up the model inputs including topography, precipitation, temperature, land use, soil-type, and nutrients from atmospheric, agricultural, industrial and urban wastewaster sources, over the entire model domain. Daily river runoff data from the Baltex and GRDC databases was used to calibrate and validate the parameters describing runoff processes, while monthly and seasonal data from the European Environment Agency's WISE database were used to calibrate and validate the water quality parameters in the model. The model application is able to reproduce measured daily flow variations and magnitude in both large and small waterways across the model domain, and measured seasonal variation and overall magnitude of nutrient fluxes to the Baltic Sea. Total

  17. Carbothermal Reduction of Quartz in Different Gas Atmospheres

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Zhang, Guangqing; Tang, Kai; Ostrovski, Oleg; Tronstad, Ragnar

    2015-01-01

    This article examines the influence of gas atmosphere on the synthesis of silicon carbide by carbothermal reduction of quartz. The quartz was crushed to <70 μm, uniformly mixed with graphite and pressed into pellets. Reduction was studied in isothermal and temperature-programmed reduction experiments in a tube reactor in argon, hydrogen and Ar-H2 gas mixtures. The concentrations of CO, CO2, and CH4 in the off gas were measured online using an infrared gas analyzer. The samples after reduction were characterized by X-ray diffraction, scanning electron microscope, and LECO analyzer. The carbothermal reduction of quartz in hydrogen was faster than in argon. Formation of silicon carbide started at 1573 K (1300 °C) in argon, and 1473 K (1200 °C) in hydrogen. Synthesis of silicon carbide in hydrogen was close to completion in 270 minutes at 1673 K (1400 °C), 140 minutes at 1773 K (1500 °C), and 70 minutes at 1873 K (1600 °C). Faster carbothermal reduction rate in hydrogen was attributed to the involvement of hydrogen in the reduction reactions by directly reducing silica and/or indirectly, by reacting with graphite to form methane as an intermediate reductant.

  18. Public-policy issues associated with the SAFRR Tsunami Scenario: Chapter M in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Johnson, Laurie; Real, Chuck

    2013-01-01

    The SAFRR (Science Application for Risk Reduction) tsunami scenario simulates a tsunami generated by a hypothetical magnitude 9.1 earthquake that occurs offshore of the Alaska Peninsula (Kirby and others, 2013). In addition to the work performed by the authors on public-policy issues associated with the SAFRR tsunami scenario, this section of the scenario also reflects the policy discussions of the State of California’s Tsunami Policy Work Group, a voluntary advisory body formed in October 2011, which operates under the California Natural Resources Agency (CNRA), Department of Conservation, and is charged with identifying, evaluating, and making recommendations to resolve issues that are preventing full and effective implementation of tsunami hazard mitigation and risk reduction throughout California’s coastal communities. It also presents the analyses of plans and hazard policies of California’s coastal counties, incorporated cities, and major ports performed by the staff of the California Geological Survey (CGS) and Lauren Prehoda, Office of Environmental and Government Affairs, California Department of Conservation. It also draws on the policy framework and assessment prepared for the ARkStorm Pacific Coast winter storm and catastrophic flooding (Topping and others, 2010).

  19. Scenario Analysis of the Impact on Drinking Water Intakes from Bromide in the Discharge of Treated Oil and Gas Wastewater

    EPA Pesticide Factsheets

    EPA scientists created different scenarios for conventional commercial wastewater treatment plants that treat oil and gas wastewaters to evaluate the impact from bromide in discharges by the CWTP plants.

  20. Evaluation of Reformer Produced Synthesis Gas for Emissions Reductions in Natural Gas Reciprocating Engines

    SciTech Connect

    Mark V. Scotto; Mark A. Perna

    2010-05-30

    Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) has developed a system that produces synthesis gas from air and natural gas. A near-term application being considered for this technology is synthesis gas injection into reciprocating engines for reducing NOx emissions. A proof of concept study using bottled synthesis gas and a two-stroke reciprocating engine showed that injecting small amounts of highflammables content synthesis gas significantly improved combustion stability and enabled leaner engine operation resulting in over 44% reduction in NOx emissions. The actual NOx reduction that could be achieved in the field is expected to be engine specific, and in many cases may be even greater. RRFCS demonstrated that its synthesis gas generator could produce synthesis gas with the flammables content that was successfully used in the engine testing. An economic analysis of the synthesis gas approach estimates that its initial capital cost and yearly operating cost are less than half that of a competing NOx reduction technology, Selective Catalytic Reduction. The next step in developing the technology is an integrated test of the synthesis gas generator with an engine to obtain reliability data for system components and to confirm operating cost. RRFCS is actively pursuing opportunities to perform the integrated test. A successful integrated test would demonstrate the technology as a low-cost option to reduce NOx emissions from approximately 6,000 existing two-stroke, natural gas-fired reciprocating engines used on natural gas pipelines in North America. NOx emissions reduction made possible at a reasonable price by this synthesis gas technology, if implemented on 25% of these engines, would be on the order of 25,000 tons/year.

  1. Evaluation of Reformer Produced Synthesis Gas for Emissions Reductions in Natural Gas Reciprocating Engines

    SciTech Connect

    Mark Scotto

    2010-05-30

    Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) has developed a system that produces synthesis gas from air and natural gas. A near-term application being considered for this technology is synthesis gas injection into reciprocating engines for reducing NO{sub x} emissions. A proof of concept study using bottled synthesis gas and a two-stroke reciprocating engine showed that injecting small amounts of high-flammable content synthesis gas significantly improved combustion stability and enabled leaner engine operation resulting in over 44% reduction in NO{sub x} emissions. The actual NO{sub x} reduction that could be achieved in the field is expected to be engine specific, and in many cases may be even greater. RRFCS demonstrated that its synthesis gas generator could produce synthesis gas with the flammable content that was successfully used in the engine testing. An economic analysis of the synthesis gas approach estimates that its initial capital cost and yearly operating cost are less than half that of a competing NO{sub x} reduction technology, Selective Catalytic Reduction. The next step in developing the technology is an integrated test of the synthesis gas generator with an engine to obtain reliability data for system components and to confirm operating cost. RRFCS is actively pursuing opportunities to perform the integrated test. A successful integrated test would demonstrate the technology as a low-cost option to reduce NO{sub x} emissions from approximately 6,000 existing two-stroke, natural gas-fired reciprocating engines used on natural gas pipelines in North America. NO{sub x} emissions reduction made possible at a reasonable price by this synthesis gas technology, if implemented on 25% of these engines, would be on the order of 25,000 tons/year.

  2. Influences on Adoption of Greenhouse Gas Reduction Targets among US States, 1998-2008.

    PubMed

    Cale, Tabitha M; Reams, Margaret A

    2013-01-01

    While the United States has not established federal regulations for greenhouse gas (GHG) reduction targets, many US states have adopted their own standards and guidelines. In this study we examine state adoption of targets for GHG reductions during the ten-year period of 1998-2008, and identify factors that explain variation in target adoption. Potential influences are drawn from research from the public policy formulation and diffusion literature, and from studies specific to climate policy adoption. Potential influences on GHG reduction efforts among US states include socioeconomic attributes of residents, political and ideological orientations of citizens and state government, interest group activities, environmental pressures, and proximity to other states that have adopted GHG reduction targets. The findings of the multinomial logistic regression analysis indicate that states are more likely to adopt GHG reduction targets if they share a border with another state with a similar climate program and if their citizens are more ideologically liberal. Other factors including socioeconomic resources and interest group activities were not found to be associated with policy adoption. The findings yield insights into the conditions under which states are more likely to take action to reduce GHG's, and are relevant both to state policy makers and residents with an interest in climate planning, and for researchers attempting to estimate future greenhouse gas reduction scenarios.

  3. Characterizing the emission implications of future natural gas production and use in the U.S. and Rocky Mountain region: A scenario-based energy system modeling approach

    NASA Astrophysics Data System (ADS)

    McLeod, Jeffrey

    The recent increase in U.S. natural gas production made possible through advancements in extraction techniques including hydraulic fracturing has transformed the U.S. energy supply landscape while raising questions regarding the balance of environmental impacts associated with natural gas production and use. Impact areas at issue include emissions of methane and criteria pollutants from natural gas production, alongside changes in emissions from increased use of natural gas in place of coal for electricity generation. In the Rocky Mountain region, these impact areas have been subject to additional scrutiny due to the high level of regional oil and gas production activity and concerns over its links to air quality. Here, the MARKAL (MArket ALlocation) least-cost energy system optimization model in conjunction with the EPA-MARKAL nine-region database has been used to characterize future regional and national emissions of CO 2, CH4, VOC, and NOx attributed to natural gas production and use in several sectors of the economy. The analysis is informed by comparing and contrasting a base case, business-as-usual scenario with scenarios featuring variations in future natural gas supply characteristics, constraints affecting the electricity generation mix, carbon emission reduction strategies and increased demand for natural gas in the transportation sector. Emission trends and their associated sensitivities are identified and contrasted between the Rocky Mountain region and the U.S. as a whole. The modeling results of this study illustrate the resilience of the short term greenhouse gas emission benefits associated with fuel switching from coal to gas in the electric sector, but also call attention to the long term implications of increasing natural gas production and use for emissions of methane and VOCs, especially in the Rocky Mountain region. This analysis can help to inform the broader discussion of the potential environmental impacts of future natural gas production

  4. Intertemporal Regulatory Tasks and Responsibilities for Greenhouse Gas Reductions

    ERIC Educational Resources Information Center

    Deason, Jeffrey A.; Friedman, Lee S.

    2010-01-01

    Jurisdictions are in the process of establishing regulatory systems to control greenhouse gas emissions. Short-term and sometimes long-term emissions reduction goals are established, as California does for 2020 and 2050, but little attention has yet been focused on annual emissions targets for the intervening years. We develop recommendations for…

  5. Institutionalizing a Greenhouse Gas Emission Reduction Target at Yale

    ERIC Educational Resources Information Center

    Rauch, Jason N.; Newman, Julie

    2009-01-01

    Purpose: The purpose of this paper is to analyze the development and implementation of how a greenhouse gas GHG reduction target at Yale University has resulted in broad and long-term institutional commitment. Design/methodology/approach: Interviews are conducted with key individuals representing those most directly involved in developing and…

  6. NO(x) reduction additives for aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Adelman, Henry G.; Menees, Gene P.; Cambier, Jean-Luc

    1993-01-01

    The reduction of oxides of nitrogen (NO(x)) emissions from aircraft gas turbine engines is a vital part of the NASA High Speed Research Program. Emissions reductions are critical to the feasibility of future High Speed Civil Transports which operate at supersonic speeds in the stratosphere. It is believed that large fleets of such aircraft using conventional gas turbine engines would emit levels of NO(x) that would be harmful to the stratospheric ozone layer. Previous studies have shown that NO(x) emissions can be reduced from stationary powerplant exhausts by the addition of additives such as ammonia to the exhaust gases. Since the exhaust residence times, pressures and temperatures may be different for aircraft gas turbines, a study has been made of additive effectiveness for high speed, high altitude flight.

  7. The best MSW treatment option by considering greenhouse gas emissions reduction: a case study in Georgia.

    PubMed

    Tayyeba, Omid; Olsson, Monika; Brandt, Nils

    2011-08-01

    The grave concern over climate change and new economic incentives such as the clean development mechanism (CDM) have given more weight to the potential of projects for reducing greenhouse gas (GHG) emissions. In the Adjara solid waste management project, even though the need for reductions in GHG emissions is acknowledged, it is not one of the key factors for selecting the most appropriate treatment method. This study addresses the benefit of various solid waste treatment methods that could be used in the Adjara project in terms of reducing GHG emissions. Seven different options for solid waste treatment are examined: open dumping as the baseline case, four options for landfill technology (no provision of landfill gas capture, landfill gas capture with open flare system, with enclosed flare system and with electricity generation), composting and anaerobic digestion with electricity production. CDM methodologies were used to quantify the amount of reductions for the scenarios. The study concludes sanitary landfill with capture and burning of landfill gas by an enclosed flare system could satisfy the requirements, including GHG reduction potential. The findings were tested for uncertainty and sensitivity by varying the data on composition and amount of waste and were found to be robust.

  8. Reactive greenhouse gas scenarios: Systematic exploration of uncertainties and the role of atmospheric chemistry

    NASA Astrophysics Data System (ADS)

    Prather, Michael J.; Holmes, Christopher D.; Hsu, Juno

    2012-05-01

    Knowledge of the atmospheric chemistry of reactive greenhouse gases is needed to accurately quantify the relationship between human activities and climate, and to incorporate uncertainty in our projections of greenhouse gas abundances. We present a method for estimating the fraction of greenhouse gases attributable to human activities, both currently and for future scenarios. Key variables used to calculate the atmospheric chemistry and budgets of major non-CO2 greenhouse gases are codified along with their uncertainties, and then used to project budgets and abundances under the new climate-change scenarios. This new approach uses our knowledge of changing abundances and lifetimes to estimate current total anthropogenic emissions, independently and possibly more accurately than inventory-based scenarios. We derive a present-day atmospheric lifetime for methane (CH4) of 9.1 ± 0.9 y and anthropogenic emissions of 352 ± 45 Tg/y (64% of total emissions). For N2O, corresponding values are 131 ± 10 y and 6.5 ± 1.3 TgN/y (41% of total); and for HFC-134a, the lifetime is 14.2 ± 1.5 y.

  9. Impacts of Emission Reduction Scenarios on Regional Climate and Local Air Quality for the 2008 Beijing Olympic Games

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Smith, J. A.; Wang, Z.; Fast, J. D.; Chapman, E. G.; Wu, Q.; Baeck, M.; Michel, A. P.; Yeung, J.; Gustafson, W. I.

    2009-05-01

    Beijing implemented a long term emission reduction program in 2001 when it won the bid to host the 2008 Summer Olympic Games. During the summer of 2008 Beijing increased its emission reduction effort by integrating short term strategies such as temporally shutting down factories, freezing constructions, and automobile control. Taking advantage of emission reduction measures, numerical simulation experiments are being carried out with the Weather Research and Forecasting model with chemistry module (WRF-Chem) to examine aerosol-cloud-precipitation interactions in the Beijing metropolitan region during the period of the 2008 Olympic Games. Analyses of TRMM 3B42V6 and MODIS Terra L3C5 datasets show that August 2008 was a period of above average precipitation and below average aerosol loadings, relative to observations during the past 10 years. This study is based on numerical simulations with two emission scenarios, business as usual scenario and reduced emission scenario, to examine the impacts of emission reduction measures on regional climate and local air quality in the Beijing metropolitan region, as well as the role of cloud and precipitation processes in controlling the regional distribution of aerosols. Both of the high- resolution emission inventories were developed by the Institute of Atmospheric Physics, China, to represent the effects of emission reduction policies for the Olympic period. Intercomparisons with in-situ measurements are used to assess the capability for modeling aerosol-cloud-precipitation interactions on a regional scale. Analyses center on assessing "microphysical" and "stability" hypotheses linking aerosols to cloud and precipitation processes and examining the relative roles of precipitation processes, regional transport processes and emission reduction scenarios in producing the favorable air quality conditions during the Olympic period.

  10. Transient Climate Impacts for Scenarios of Aerosol Emissions from Asia: A Story of Coal versus Gas

    NASA Astrophysics Data System (ADS)

    Grandey, B. S.; Cheng, H.; Wang, C.

    2014-12-01

    Projections of anthropogenic aerosol emissions are uncertain. In Asia, it is possible that emissions may increase if business continues as usual, with economic growth driving an increase in coal burning. But it is also possible that emissions may decrease rapidly due to the widespread adoption of cleaner technology or a shift towards non-coal fuels, such as natural gas. In this study, the transient climate impacts of three aerosol emissions scenarios are investigated: an RCP4.5 (Representative Concentration Pathway 4.5) control; a scenario with reduced Asian anthropogenic aerosol emissions; and a scenario with enhanced Asian anthropogenic aerosol emissions. A coupled atmosphere-ocean configuration of CESM (Community Earth System Model), including CAM5 (Community Atmosphere Model version 5), is used. Enhanced Asian aerosol emissions are found to delay global mean warming by one decade at the end of the century. Aerosol-induced suppression of the East Asian and South Asian summer monsoon precipitation occurs. The enhanced Asian aerosol emissions also remotely impact precipitation in other parts of the world: over the Sahel, West African monsoon precipitation is suppressed; and over Australia, austral summer monsoon precipitation is enhanced. These remote impacts on precipitation are associated with a southward shift of the ITCZ. The aerosol-induced sea surface temperature (SST) response appears to play an important role in the precipitation changes over South Asia and Australia, but not over East Asia. These results indicate that energy production in Asia, through the consequent aerosol emissions and associated radiative effects, might significantly influence future climate both locally and globally.

  11. Non-Kyoto Radiative Forcing in Long-Run Greenhouse Gas Emissions and Climate Change Scenarios

    SciTech Connect

    Rose, Steven K.; Richels, Richard G.; Smith, Steven J.; Riahi, Keywan; Stefler, Jessica; Van Vuuren, Detlef

    2014-04-27

    Climate policies designed to achieve climate change objectives must consider radiative forcing from the Kyoto greenhouse gas, as well as other forcing constituents, such as aerosols and tropospheric ozone. Net positive forcing leads to global average temperature increases. Modeling of non-Kyoto forcing is a relatively new component of climate management scenarios. Five of the nineteen models in the EMF-27 Study model both Kyoto and non-Kyoto forcing. This paper describes and assesses current non-Kyoto radiative forcing modeling within these integrated assessment models. The study finds negative forcing from aerosols masking significant positive forcing in reference non-climate policy projections. There are however large differences across models in projected non-Kyoto emissions and forcing, with differences stemming from differences in relationships between Kyoto and non-Kyoto emissions and fundamental differences in modeling structure and assumptions. Air pollution and non-Kyoto forcing decline in the climate policy scenarios. However, non-Kyoto forcing appears to be influencing mitigation results, including allowable carbon dioxide emissions, and further evaluation is merited. Overall, there is substantial uncertainty related to non-Kyoto forcing that must be considered.

  12. THE ANALYSIS OF GREENHOUSE GAS REDUCTION TARGETS IN JAPAN USING A COMPUTABLE GENERAL EQUILIBRIUM MODEL

    NASA Astrophysics Data System (ADS)

    Namazu, Michiko; Fujimori, Shinichiro; Matsuoka, Yuzuru

    In this study, a recursive dynamic Computable General Equilibrium (CGE) model which can deal with Greenhouse Gas (GHG) constraint is applied to Japan. Based on several references, Japan's emissions reduction targets are determined as 25% reduction from 1990 level by 2020 and 80% reduction from 2005 level by 2050 in this study. Several cases with different scenarios for nuclear power plant, international emissions trading, and CO2 Capture and Strage (CCS) technology are simulated using the CGE model. By comparison among the results of each case, the effects, especially economic effects are evaluated and analyzed quantitatively. The results show that the most important counter measure to achieve GHG emissions reduction targets in Japan is whether Japan joins international emissions trading or not. In a no-trading case, in which GHG emissions constraints are imposed and Japan does not participate to the trading, GHG reduction costs reach 2,560 USD/tCO2-eq,yr (2005 price) in 2050. In addition, Gross Domestic Product (GDP) decreases 3.8% compared with a counter measure case in which GHG constraints are imposed but the emissions trading is allowed. The results also show that in case Japan targets no nuclear power plants in 2050, CCS technology and emissions trading are able to make up for the gap resulted from the nuclear power decrease. About the speed of CCS technology introduction, the share of power plants with CCS technology is changed depended on the speed; however, GDP and GHG reduction costs do not affected so much.

  13. [Synergistic emission reduction of chief air pollutants and greenhouse gases-based on scenario simulations of energy consumptions in Beijing].

    PubMed

    Xie, Yuan-bo; Li, Wei

    2013-05-01

    It is one of the common targets and important tasks for energy management and environmental control of Beijing to improve urban air quality while reducing the emissions of greenhouse gases (GHG). Here, based on the interim and long term developmental planning and energy structure of the city, three energy consumption scenarios in low, moderate and high restrictions were designed by taking the potential energy saving policies and environmental targets into account. The long-range energy alternatives planning (LEAP) model was employed to predict and evaluate reduction effects of the chief air pollutants and GHG during 2010 to 2020 under the three given scenarios. The results showed that if urban energy consumption system was optimized or adjusted by exercising energy saving and emission reduction and pollution control measures, the predicted energy uses will be reduced by 10 to 30 million tons of coal equivalents by 2020. Under the two energy scenarios with moderate and high restrictions, the anticipated emissions of SO2, NOx, PM10, PM2.5, VOC and GHG will be respectively reduced to 71 to 100.2, 159.2 to 218.7, 89.8 to 133.8, 51.4 to 96.0, 56.4 to 74.8 and 148 200 to 164 700 thousand tons. Correspondingly, when compared with the low-restriction scenario, the reducing rate will be 53% to 67% , 50% to 64% , 33% to 55% , 25% to 60% , 41% to 55% and 26% to 34% respectively. Furthermore, based on a study of synergistic emission reduction of the air pollutants and GHG, it was proposed that the adjustment and control of energy consumptions shall be intensively developed in the three sectors of industry, transportation and services. In this way the synergistic reduction of the emissions of chief air pollutants and GHG will be achieved; meanwhile the pressures of energy demands may be deliberately relieved.

  14. Economic impacts of the SAFRR tsunami scenario in California: Chapter H in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Wein, Anne; Rose, Adam; Sue Wing, Ian; Wei, Dan

    2013-01-01

    This study evaluates the hypothetical economic impacts of the SAFRR (Science Application for Risk Reduction) tsunami scenario to the California economy. The SAFRR scenario simulates a tsunami generated by a hypothetical magnitude 9.1 earthquake that occurs offshore of the Alaska Peninsula (Kirby and others, 2013). Economic impacts are measured by the estimated reduction in California’s gross domestic product (GDP), the standard economic measure of the total value of goods and services produced. Economic impacts are derived from the physical damages from the tsunami as described by Porter and others (2013). The principal physical damages that result in disruption of the California economy are (1) about $100 million in damages to the twin Ports of Los Angeles (POLA) and Long Beach (POLB), (2) about $700 million in damages to marinas, and (3) about $2.5 billion in damages to buildings and contents (properties) in the tsunami inundation zone on the California coast. The study of economic impacts does not include the impacts from damages to roads, bridges, railroads, and agricultural production or fires in fuel storage facilities because these damages will be minimal with respect to the California economy. The economic impacts of damage to other California ports are not included in this study because detailed evaluation of the physical damage to these ports was not available in time for this report. The analysis of economic impacts is accomplished in several steps. First, estimates are made for the direct economic impacts that result in immediate business interruption losses in individual sectors of the economy due to physical damage to facilities or to disruption of the flow of production units (commodities necessary for production). Second, the total economic impacts (consisting of both direct and indirect effects) are measured by including the general equilibrium (essentially quantity and price multiplier effects) of lost production in other sectors by ripple

  15. Modeling of Future-Year Emissions Control Scenarios for the Lower Fraser Valley: Impacts of Natural Gas and Propane Vehicle Technologies.

    NASA Astrophysics Data System (ADS)

    Hedley, M.; Jiang, W.; McLaren, R.; Singleton, D. L.

    1998-10-01

    The MC2-CALGRID photochemical modeling system is used to simulate the impact of two fuel substitution scenarios on ozone levels for a future year in the Lower Fraser Valley of British Columbia, Canada. The relative impacts of selected natural gas and propane vehicle technologies are compared for the year 2005. The chosen natural gas technology imposes large reductions in nonmethane hydrocarbon emissions with moderate reductions in nitrogen oxide emissions, while the propane technology greatly lowers nitrogen oxide emissions with only small changes to nonmethane hydrocarbon emissions.The model results showed that replacing the entire light-duty gasoline car and truck fleet with the selected natural gas vehicle technology in the year 2005 in the Canadian portion of the Lower Fraser Valley yielded significant benefits in terms of reducing potential exposures to elevated ozone levels in suburban and rural areas. Sites closer to the urban core were less affected. For the propane fuel substitution, benefits were realized in terms of lowering ozone concentrations and ozone exposures in the rural areas. Within the urban and suburban areas, ozone exposures tended to increase. The exposures to peroxyacetyl nitrate were universally smaller in the alternative fuel scenarios.The nature of an effective control strategy for the Lower Fraser Valley is discussed, and it is suggested that in addition to the propane fuel substitution, moderate controls on the primary NOx sources in conjunction with moderate nonmethane hydrocarbon controls could be the preferred route to lower ozone exposures.

  16. Up to what point is loss reduction environmentally friendly?: The LCA of loss reduction scenarios in drinking water networks.

    PubMed

    Pillot, Julie; Catel, Laureline; Renaud, Eddy; Augeard, Bénédicte; Roux, Philippe

    2016-11-01

    In a context of increasing water shortage all over the world, water utilities must minimise losses in their distribution networks and draw up water loss reduction action plans. While leak reduction is clearly an important part of sustainable water management, its impacts have to be reconsidered in a broader objective of environmental protection than strictly the avoided losses in cubic metres of water. Reducing the volume of water abstracted reduces also environmental impacts associated to water production (the operation and infrastructure needed for abstraction, treatment, supply). In the mean time, activities for reducing water losses generate their own environmental impacts, notably as a result of the work, equipment, and infrastructures used for this purpose. In this study, Life Cycle Assessment (LCA) was used to assess and compare two sets of environmental impacts: those resulting from the production and supply of water which will never reach subscribers, and those caused by water loss reduction activities. This information can then be used to establish whether or not there is a point beyond which loss reduction is no longer effective in reducing the environmental impacts of drinking water supply. Results show that the improvement actions that start from a low water supply efficiency are clearly beneficial for ecosystems, human health and preservation of resources. When seeking to improve the efficiency beyond certain values (about 65%), the uncertainty makes it impossible to conclude for an environmental benefit on all impact categories.

  17. Ecosystem Services in Lakes of the Northeastern United States: Upstream Benefits from Estuarine Nitrogen Reduction Scenarios

    EPA Science Inventory

    Reduction of nitrogen inputs to estuaries can be achieved by the control of agricultural, atmospheric, and urban sources. We use the USGS MRB1 SPARROW model to estimate reductions necessary to reduce nitrogen loads to estuaries by 10%. If only agricultural inputs are reduced, ...

  18. Survey of inlet noise reduction concepts for gas turbine engines

    NASA Technical Reports Server (NTRS)

    Lansing, D. L.; Chestnutt, D.

    1976-01-01

    An overview is given of advanced concepts for the suppression of noise in the inlets of gas turbine engines. Inlet geometric and operating parameters are presented and design criteria for suppression methods are discussed. Noise suppression concepts are described, the directions of current research are reviewed. Problem areas requiring further work are indicated. Well established approaches to inlet noise reduction - namely, acoustic liners and high subsonic Mach number inlets which are the focus of considerable current research activity are considered along with the acoustic absorption and watet vapor injection.

  19. Benefits of improved municipal solid waste management on greenhouse gas reduction in Luangprabang, Laos.

    PubMed

    Vilaysouk, Xaysackda; Babel, Sandhya

    2017-03-16

    Climate change is a consequence of greenhouse gas emissions. Greenhouse gas (GHG) emissions from the waste sector contribute to 3% of total anthropogenic emissions. In this study, applicable solutions for municipal solid waste (MSW) management in Luangprabang (LPB) and Laos were examined. Material flow analysis of MSW was performed to estimate the amount of MSW generated in 2015. Approximately 29,419 tonnes of MSW is estimated for 2015. Unmanaged landfilling was the main disposal method, while MSW open burning was also practiced to some extent. The International Panel on Climate Change 2006 model and the Atmospheric Brown Clouds Emission Inventory Manual were used to estimate GHG emissions from existing MSW management, and total emissions are 33,889 tonnes/year carbon dioxide-equivalents (CO2-eq). Three scenarios were developed in order to reduce GHG emissions and environmental problems. Improvement of the MSW management by expanding MSW collection services, introducing composting and recycling, and avoiding open burning, can be considered as solutions to overcome the problems for LPB. The lowest GHG emissions are achieved in the scenario where composting and recycling are proposed, with the total GHG emissions reduction by 18,264 tonnes/year CO2-eq.

  20. Small-scale, partial-equilibrium model of natural gas markets: responses to alternative deregulation scenarios and oil price changes

    SciTech Connect

    Green, D.J.

    1984-04-01

    A small scale model of natural gas markets explains regulated gas prices using past changes in residual fuel oil prices. The study examines three different accelerated, complete wellhead gas decontrol scenarios to find the impact of current law, immediate decontrol, and accelerated decontrol. It finds that accelerated decontrol simply shifts price increases forward with minor impact, while the revenue transfers are fairly substantial. A windfall profits tax could capture much of this transfer, but the revenues from such a tax would decrease sharply by the end of the period. 23 references, 4 figures, 8 tables.

  1. Sensitive gas chromatographic detection of acetaldehyde and acetone using a reduction gas detector

    NASA Technical Reports Server (NTRS)

    O'Hara, Dean; Singh, Hanwant B.

    1988-01-01

    The response of a newly available mercuric oxide Reduction Gas Detector (RGD-2) to subpicomole and larger quantities of acetaldehyde and acetone is tested. The RGD-2 is found to be capable of subpicomole detection for these carbonyls and is more sensitive than an FID (Flame Ionization Detector) by an order of magnitude. Operating parameters can be further optimized to make the RGD-2 some 20-40 times more sensitive than an FID. The detector is linear over a wide range and is easily adapted to a conventional gas chromatograph (GC). Such a GC-RGD-2 system should be suitable for atmospheric carbonyl measurements in clean as well as polluted environments.

  2. The SAFRR tsunami scenario-physical damage in California: Chapter E in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Porter, Keith; Byers, William; Dykstra, David; Lim, Amy; Lynett, Patrick; Ratliff, Jaime; Scawthorn, Charles; Wein, Anne; Wilson, Rick

    2013-01-01

    his chapter attempts to depict a single realistic outcome of the SAFRR (Science Application for Risk Reduction) tsunami scenario in terms of physical damage to and recovery of various aspects of the built environment in California. As described elsewhere in this report, the tsunami is generated by a hypothetical magnitude 9.1 earthquake seaward of the Alaska Peninsula on the Semidi Sector of the Alaska–Aleutian Subduction Zone, 495 miles southwest of Anchorage, at 11:50 a.m. Pacific Daylight Time (PDT) on Thursday March 27, 2014, and arriving at the California coast between 4:00 and 5:40 p.m. (depending on location) the same day. Although other tsunamis could have locally greater impact, this source represents a substantial threat to the state as a whole. One purpose of this chapter is to help operators and users of coastal assets throughout California to develop emergency plans to respond to a real tsunami. Another is to identify ways that operators or owners of these assets can think through options for reducing damage before a future tsunami. A third is to inform the economic analyses for the SAFRR tsunami scenario. And a fourth is to identify research needs to better understand the possible consequences of a tsunami on these assets. The asset classes considered here include the following: Piers, cargo, buildings, and other assets at the Ports of Los Angeles and Long Beach Large vessels in the Ports of Los Angeles and Long Beach Marinas and small craft Coastal buildings Roads and roadway bridges Rail, railway bridges, and rolling stock Agriculture Fire following tsunami Each asset class is examined in a subsection of this chapter. In each subsection, we generally attempt to offer a historical review of damage. We characterize and quantify the assets exposed to loss and describe the modes of damage that have been observed in past tsunamis or are otherwise deemed likely to occur in the SAFRR tsunami scenario. Where practical, we offer a mathematical model of the

  3. Reduction of acetone to isopropanol using producer gas fermenting microbes.

    PubMed

    Ramachandriya, Karthikeyan D; Wilkins, Mark R; Delorme, Marthah J M; Zhu, Xiaoguang; Kundiyana, Dimple K; Atiyeh, Hasan K; Huhnke, Raymond L

    2011-10-01

    Gasification-fermentation is an emerging technology for the conversion of lignocellulosic materials into biofuels and specialty chemicals. For effective utilization of producer gas by fermenting bacteria, tar compounds produced in the gasification process are often removed by wet scrubbing techniques using acetone. In a preliminary study using biomass generated producer gas scrubbed with acetone, an accumulation of acetone and subsequent isopropanol production was observed. The effect of 2 g/L acetone concentrations in the fermentation media on growth and product distributions was studied with "Clostridium ragsdalei," also known as Clostridium strain P11 or P11, and Clostridium carboxidivorans P7 or P7. The reduction of acetone to isopropanol was possible with "C. ragsdalei," but not with P7. In P11 this reaction occurred rapidly when acetone was added in the acidogenic phase, but was 2.5 times slower when added in the solventogenic phase. Acetone at concentrations of 2 g/L did not affect the growth of P7, but ethanol increased by 41% and acetic acid concentrations decreased by 79%. In the fermentations using P11, growth was unaffected and ethanol concentrations increased by 55% when acetone was added in the acidogenic phase. Acetic acid concentrations increased by 19% in both the treatments where acetone was added. Our observations indicate that P11 has a secondary alcohol dehydrogenase that enables it to reduce acetone to isopropanol, while P7 lacks this enzyme. P11 offers an opportunity for biological production of isopropanol from acetone reduction in the presence of gaseous substrates (CO, CO₂, and H₂).

  4. Integrated catchment modeling for nutrient reduction: scenarios showing impacts, potential, and cost of measures.

    PubMed

    Arheimer, Berit; Löwgren, Marianne; Pers, Bodil Charlotta; Rosberg, Jörgen

    2005-11-01

    A hydrological-based model (HBV-NP) was applied to a catchment (1900 km2) in the southern part of Sweden. Careful characterization of the present load situation and the potential for improved treatment or reduced soil leaching were analyzed. Several scenarios were modeled to find strategies to reach the Swedish environmental goals of reducing anthropogenic nitrogen load by 30% and phosphorus load by 20%. It was stated that the goals could be reached by different approaches that would affect different polluters and social sectors. However, no single measure was enough by itself. Instead, a combination of measures was necessary to achieve the goals. The nitrogen goal was the most difficult to attain. In order to be cost-effective, these measures should be applied to areas contributing the most to the net loading of the sea. This strategy could reduce the costs by 70%-80% when compared with implementing the measures in the entire catchment. Integrated catchment models may thus be helpful tools for reducing costs in environmental control programs.

  5. Greenhouse gas emissions during plantation stage of palm oil-based biofuel production addressing different land conversion scenarios in Malaysia.

    PubMed

    Kusin, Faradiella Mohd; Akhir, Nurul Izzati Mat; Mohamat-Yusuff, Ferdaus; Awang, Muhamad

    2017-02-01

    The environmental impacts with regard to agro-based biofuel production have been associated with the impact of greenhouse gas (GHG) emissions. In this study, field GHG emissions during plantation stage of palm oil-based biofuel production associated with land use changes for oil palm plantation development have been evaluated. Three different sites of different land use changes prior to oil palm plantation were chosen; converted land-use (large and small-scales) and logged-over forest. Field sampling for determination of soil N-mineralisation and soil organic carbon (SOC) was undertaken at the sites according to the age of palm, i.e. <5 years (immature), 5-20 and >21 years (mature oil palms). The field data were incorporated into the estimation of nitrous oxide (N2O) and the resulting CO2-eq emissions as well as for estimation of carbon stock changes. Irrespective of the land conversion scenarios, the nitrous oxide emissions were found in the range of 6.47-7.78 kg N2O-N/ha resulting in 498-590 kg CO2-eq/ha. On the other hand, the conversion of tropical forest into oil palm plantation has resulted in relatively higher GHG emissions (i.e. four times higher and carbon stock reduction by >50%) compared to converted land use (converted rubber plantation) for oil palm development. The conversion from previously rubber plantation into oil palm plantation would increase the carbon savings (20% in increase) thus sustaining the environmental benefits from the palm oil-based biofuel production.

  6. Modeling for the SAFRR Tsunami Scenario-generation, propagation, inundation, and currents in ports and harbors: Chapter D in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    ,

    2013-01-01

    This U.S. Geological Survey (USGS) Open-File report presents a compilation of tsunami modeling studies for the Science Application for Risk Reduction (SAFRR) tsunami scenario. These modeling studies are based on an earthquake source specified by the SAFRR tsunami source working group (Kirby and others, 2013). The modeling studies in this report are organized into three groups. The first group relates to tsunami generation. The effects that source discretization and horizontal displacement have on tsunami initial conditions are examined in section 1 (Whitmore and others). In section 2 (Ryan and others), dynamic earthquake rupture models are explored in modeling tsunami generation. These models calculate slip distribution and vertical displacement of the seafloor as a result of realistic fault friction, physical properties of rocks surrounding the fault, and dynamic stresses resolved on the fault. The second group of papers relates to tsunami propagation and inundation modeling. Section 3 (Thio) presents a modeling study for the entire California coast that includes runup and inundation modeling where there is significant exposure and estimates of maximum velocity and momentum flux at the shoreline. In section 4 (Borrero and others), modeling of tsunami propagation and high-resolution inundation of critical locations in southern California is performed using the National Oceanic and Atmospheric Administration’s (NOAA) Method of Splitting Tsunami (MOST) model and NOAA’s Community Model Interface for Tsunamis (ComMIT) modeling tool. Adjustments to the inundation line owing to fine-scale structures such as levees are described in section 5 (Wilson). The third group of papers relates to modeling of hydrodynamics in ports and harbors. Section 6 (Nicolsky and Suleimani) presents results of the model used at the Alaska Earthquake Information Center for the Ports of Los Angeles and Long Beach, as well as synthetic time series of the modeled tsunami for other selected

  7. Simulation and evaluation of pollution load reduction scenarios for water environmental management: a case study of inflow river of Taihu Lake, China.

    PubMed

    Zhang, Ruibin; Qian, Xin; Zhu, Wenting; Gao, Hailong; Hu, Wei; Wang, Jinhua

    2014-09-09

    In the beginning of the 21st century, the deterioration of water quality in Taihu Lake, China, has caused widespread concern. The primary source of pollution in Taihu Lake is river inflows. Effective pollution load reduction scenarios need to be implemented in these rivers in order to improve the water quality of Taihu Lake. It is important to select appropriate pollution load reduction scenarios for achieving particular goals. The aim of this study was to facilitate the selection of appropriate scenarios. The QUAL2K model for river water quality was used to simulate the effects of a range of pollution load reduction scenarios in the Wujin River, which is one of the major inflow rivers of Taihu Lake. The model was calibrated for the year 2010 and validated for the year 2011. Various pollution load reduction scenarios were assessed using an analytic hierarchy process, and increasing rates of evaluation indicators were predicted using the Delphi method. The results showed that control of pollution from the source is the optimal method for pollution prevention and control, and the method of "Treatment after Pollution" has bad environmental, social and ecological effects. The method applied in this study can assist for environmental managers to select suitable pollution load reduction scenarios for achieving various objectives.

  8. A scenario analysis of the life cycle greenhouse gas emissions of a new residential area

    NASA Astrophysics Data System (ADS)

    Säynäjoki, Antti; Heinonen, Jukka; Junnila, Seppo

    2012-09-01

    While buildings are often credited as accounting for some 40% of the global greenhouse gas (GHG) emissions, the construction phase is typically assumed to account for only around one tenth of the overall emissions. However, the relative importance of construction phase emissions is quickly increasing as the energy efficiency of buildings increases. In addition, the significance of construction may actually be much higher when the temporal perspective of the emissions is taken into account. The construction phase carbon spike, i.e. high GHG emissions in a short time associated with the beginning of the building’s life cycle, may be high enough to question whether new construction, no matter how energy efficient the buildings are, can contribute to reaching the greenhouse gas mitigation goals of the near future. Furthermore, the construction of energy efficient buildings causes more GHG emissions than the construction of conventional buildings. On the other hand, renovating the current building stock together with making energy efficiency improvements might lead to a smaller construction phase carbon spike and still to the same reduced energy consumption in the use phase as the new energy efficient buildings. The study uses a new residential development project in Northern Europe to assess the overall life cycle GHG emissions of a new residential area and to evaluate the influence of including the temporal allocation of the life cycle GHG emissions in the assessment. In the study, buildings with different energy efficiency levels are compared with a similar hypothetical area of buildings of the average existing building stock, as well as with a renovation of an area with average buildings from the 1960s. The GHG emissions are modeled with a hybrid life cycle assessment. The study suggests that the carbon payback time of constructing new residential areas is several decades long even when using very energy efficient buildings compared to utilizing the current

  9. Population vulnerability and evacuation challenges in California for the SAFRR tsunami scenario: Chapter I in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Wood, Nathan; Ratliff, Jamie; Peters, Jeff; Shoaf, Kimberley

    2013-01-01

    The SAFRR tsunami scenario models the impacts of a hypothetical yet plausible tsunami associated with a magnitude 9.1 megathrust earthquake east of the Alaska Peninsula. This report summarizes community variations in population vulnerability and potential evacuation challenges to the tsunami. The most significant public-health concern for California coastal communities during a distant-source tsunami is the ability to evacuate people out of potential inundation zones. Fatalities from the SAFRR tsunami scenario could be low if emergency managers can implement an effective evacuation in the time between tsunami generation and arrival, as well as keep people from entering tsunami-prone areas until all-clear messages can be delivered. This will be challenging given the estimated 91,956 residents, 81,277 employees, as well as numerous public venues, dependent-population facilities, community-support businesses, and high-volume beaches that are in the 79 incorporated communities and 17 counties that have land in the scenario tsunami-inundation zone. Although all coastal communities face some level of threat from this scenario, the highest concentrations of people in the scenario tsunami-inundation zone are in Long Beach, San Diego, Newport Beach, Huntington Beach, and San Francisco. Communities also vary in the prevalent categories of populations that are in scenario tsunami-inundation zones, such as residents in Long Beach, employees in San Francisco, tourists at public venues in Santa Cruz, and beach or park visitors in unincorporated Los Angeles County. Certain communities have higher percentages of groups that may need targeted outreach and preparedness training, such as renters, the very young and very old, and individuals with limited English-language skills or no English-language skills at all. Sustained education and targeted evacuation messaging is also important at several high-occupancy public venues in the scenario tsunami-inundation zone (for example, city

  10. Quantifying climate change mitigation potential in Great Plains wetlands for three greenhouse gas emission scenarios

    USGS Publications Warehouse

    Byrd, Kristin B.; Ratliff, Jamie L.; Wein, Anne; Bliss, Norman B.; Sleeter, Benjamin M.; Sohl, Terry L.; Li, Zhengpeng

    2015-01-01

    We examined opportunities for avoided loss of wetland carbon stocks in the Great Plains of the United States in the context of future agricultural expansion through analysis of land-use land-cover (LULC) change scenarios, baseline carbon datasets and biogeochemical model outputs. A wetland map that classifies wetlands according to carbon pools was created to describe future patterns of carbon loss and potential carbon savings. Wetland avoided loss scenarios, superimposed upon LULC change scenarios, quantified carbon stocks preserved under criteria of carbon densities or land value plus cropland suitability. Up to 3420 km2 of wetlands may be lost in the region by 2050, mainly due to conversion of herbaceous wetlands in the Temperate Prairies where soil organic carbon (SOC) is highest. SOC loss would be approximately 0.20 ± 0.15 megagrams of carbon per hectare per year (MgC ha−1 yr−1), depending upon tillage practices on converted wetlands, and total ecosystem carbon loss in woody wetlands would be approximately 0.81 ± 0.41 MgC ha−1 yr−1, based on biogeochemical model results. Among wetlands vulnerable to conversion, wetlands in the Northern Glaciated Plains and Lake Agassiz Plains ecoregions exhibit very high mean SOC and on average, relatively low land values, potentially creating economically competitive opportunities for avoided carbon loss. This mitigation scenarios approach may be adapted by managers using their own preferred criteria to select sites that best meet their objectives. Results can help prioritize field-based assessments, where site-level investigations of carbon stocks, land value, and consideration of local priorities for climate change mitigation programs are needed.

  11. Real Gas: CFD Prediction Methodology Flow Physics for Entry Capsule Mission Scenarios

    NASA Technical Reports Server (NTRS)

    Deiwert, George S.

    1997-01-01

    Mission and concept studies for space exploration are described for the purpose of identifying flow physics for entry capsule mission scenarios. These studies are a necessary precursor to the development and application of CFD prediction methodology for capsule aerothermodynamics. The scope of missions considered includes manned and unmanned cislunar missions, missions to the minor planets, and missions to the major planets and other celestial objects in the solar system.

  12. Carbothermic Reduction of Chromite Ore Under Different Flow Rates of Inert Gas

    NASA Astrophysics Data System (ADS)

    Chakraborty, Dolly; Ranganathan, S.; Sinha, S. N.

    2010-02-01

    The reduction of chromite ore with carbon has been studied extensively in many laboratories. Inert gases have been used in these investigations to control the experimental conditions. However, little information is available in the literature on the influence of the gas flow rate on the rate of reduction. Experiments were carried out to study the influence of the flow rate of inert gas on the reducibility of chromite ore. The experiments showed that the rate of reduction increased with the increasing flow rate of argon up to an optimum flow rate. At higher flow rates, the rate of reduction decreased. The influence of the proportion of reductant on the extent of reduction depended on the rate of flow rate of inert gas. The experimental results are interpreted on the basis of a model that postulates that the mechanism of reduction changes with the flow rate of argon.

  13. DEROCS: A computer program to simulate offshore oil and natural gas development scenarios and onshore service base requirements

    USGS Publications Warehouse

    Marcus, Philip A.; Smith, E.T.; Robinson, S.R.; Wong, A.T.

    1977-01-01

    The FORTRAN IV (H) computer program, DEROCS, constructs Outer Continental Shelf (OCS) resource development scenarios and quantifies the requirements for and impacts of the operation of the onshore service bases necessary to support offshore oil and gas operations. The acronym DEROCS stands for 'Development of Energy Resources of the Outer Continental Shelf.' The user may specify the number, timing, and amounts of offshore oil and natural gas finds, onshore service base locations, and multiplier relationships between offshore development activities and onshore land, supply, labor and facility requirements. The program determines schedules of platform installation, development drilling, production from platforms, and well workover, and calculates on a yearly basis the requirements for and impacts of the operation of the onshore service bases demanded by offshore activities. We present two examples of program application.

  14. Gas-phase mercury reduction to measure total mercury in the flue gas of a coal-fired boiler.

    PubMed

    Meischen, Sandra J; Van Pelt, Vincent J; Zarate, Eugene A; Stephens, Edward A

    2004-01-01

    Gaseous elemental and total (elemental + oxidized) mercury (Hg) in the flue gas from a coal-fired boiler was measured by a modified ultraviolet (UV) spectrometer. Challenges to Hg measurement were the spectral interferences from other flue gas components and that UV measures only elemental Hg. To eliminate interference from flue gas components, a cartridge filled with gold-coated sand removed elemental Hg from a flue gas sample. The Hg-free flue gas was the reference gas, eliminating the spectral interferences. To measure total Hg by UV, oxidized Hg underwent a gas-phase, thermal-reduction in a quartz cell heated to 750 degrees C. Simultaneously, hydrogen was added to flash react with the oxygen present forming water vapor and preventing Hg re-oxidation as it exits the cell. Hg concentration results are in parts per billion by volume Hg at the flue gas oxygen concentration. The modified Hg analyzer and the Ontario Hydro method concurrently measured Hg at a field test site. Measurements were made at a 700-MW steam turbine plant with scrubber units and selective catalytic reduction. The flue gas sampled downstream of the selective catalytic reduction contained 2100 ppm SO2 and 75 ppm NOx. Total Hg measured by the Hg analyzer was within 20% of the Ontario Hydro results.

  15. Effects of Temperature and Gas Composition on Reduction and Swelling of Magnetite Concentrates

    NASA Astrophysics Data System (ADS)

    Kapelyushin, Yury; Sasaki, Yasushi; Zhang, Jianqiang; Jeong, Sunkwang; Ostrovski, Oleg

    2016-08-01

    The gaseous reduction of magnetite ore concentrates was studied using CO-CO2 and CO-CO2-H2 gas mixtures at different temperatures and gas compositions. The reduction of magnetite ore by CO-CO2 gas mixture was examined at temperatures 973 K to 1173 K (700 °C to 900 °C) at CO/CO2 ratio 80/20, and at varied CO/CO2 ratio from 60/40 to 85/15 at 1023 K (750 °C). In the reduction of magnetite ore by CO-CO2-H2 gas mixture, temperature was 1173 K (800 °C) and hydrogen content changed from 5 to 25 vol pct at constant CO/CO2 ratio of 80/20. Reduction of magnetite ore did not go to completion in both CO-CO2 and CO-CO2-H2 gas mixtures. Addition of H2 to the CO-CO2 gas mixture accelerated the reduction in the first 10 to 30 minutes of reaction. However, the degree of reduction by gas containing 5 to 25 vol pct H2 after 60 to 120 minutes of reaction was in the range 60 to 65 pct, while the degree of reduction by CO-CO2 gas (80 vol pct CO) after 120 minutes of reaction was close to 70 pct. Significant swelling of magnetite ore pellets was observed in the reduction by CO-CO2 gas mixture. Addition of H2 to the CO-CO2 gas mixture decreased swelling. Swelling of magnetite ore during the reduction was attributed to the breakout of iron layer caused by the increase of the inner pressure in the voids at the wüstite/iron phase boundary.

  16. Effectiveness in the use of natural gas for the reduction of atmospheric emissions: case study--industrial sector in the metropolitan region of Santiago, Chile.

    PubMed

    Corvalán, Roberto M; Galecio, Javier I; Salim, José A

    2003-08-01

    The purpose of this investigation was to quantify the potential of natural gas to reduce emissions from stationary combustion sources by analyzing the case study of the metropolitan region of Santiago, Chile. For such purposes, referential base scenarios have been defined that represent with and without natural gas settings. The method to be applied is an emission estimate based on emission factors. The results for this case study reveal that stationary combustion sources that replaced their fuel reduced particulate matter (PM) emissions by 61%, sulfur oxides (SOx) by 91%, nitrogen oxides (NOx) by 40%, and volatile organic compounds (VOC) by 10%. Carbon monoxide (CO) emissions were reduced by 1%. As a result of this emission reduction, in addition to reductions caused by other factors, such as a shift to cleaner fuels other than natural gas, technological improvements, and sources which are not operative, emission reduction goals set forth by the environmental authorities were broadly exceeded.

  17. SAFRR tsunami scenario: impacts on California ecosystems, species, marine natural resources, and fisheries: Chapter G in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Brosnan, Deborah; Wein, Anne; Wilson, Rick; Ross, Stephanie; Jones, Lucile

    2014-01-01

    We evaluate the effects of the SAFRR Tsunami Scenario on California’s ecosystems, species, natural resources, and fisheries. We discuss mitigation and preparedness approaches that can be useful in Tsunami planning. The chapter provides an introduction to the role of ecosystems and natural resources in tsunami events (Section 1). A separate section focuses on specific impacts of the SAFRR Tsunami Scenario on California’s ecosystems and endangered species (Section 2). A section on commercial fisheries and the fishing fleet (Section 3) documents the plausible effects on California’s commercial fishery resources, fishing fleets, and communities. Sections 2 and 3 each include practical preparedness options for communities and suggestions on information needs or research. Our evaluation indicates that many low-lying coastal habitats, including beaches, marshes and sloughs, rivers and waterways connected to the sea, as well as nearshore submarine habitats will be damaged by the SAFRR Tsunami Scenario. Beach erosion and complex or high volumes of tsunami-generated debris would pose major challenges for ecological communities. Several endangered species and protected areas are at risk. Commercial fisheries and fishing fleets will be affected directly by the tsunami and indirectly by dependencies on infrastructure that is damaged. There is evidence that in some areas intact ecosystems, notably sand dunes, will act as natural defenses against the tsunami waves. However, ecosystems do not provide blanket protection against tsunami surge. The consequences of ecological and natural resource damage are estimated in the millions of dollars. These costs are driven partly by the loss of ecosystem services, as well as cumulative and follow-on impacts where, for example, increased erosion during the tsunami can in turn lead to subsequent damage and loss to coastal properties. Recovery of ecosystems, natural resources and fisheries is likely to be lengthy and expensive

  18. Reduction of aircraft gas turbine engine pollutant emissions

    NASA Technical Reports Server (NTRS)

    Diehl, L. A.

    1978-01-01

    To accomplish simultaneous reduction of unburned hydrocarbons, carbon monoxide, and oxides of nitrogen, required major modifications to the combustor. The modification most commonly used was a staged combustion technique. While these designs are more complicated than production combustors, no insurmountable operational difficulties were encountered in either high pressure rig or engine tests which could not be resolved with additional normal development. The emission reduction results indicate that reductions in unburned hydrocarbons were sufficient to satisfy both near and far-termed EPA requirements. Although substantial reductions were observed, the success in achieving the CO and NOx standards was mixed and depended heavily on the engine/engine cycle on which it was employed. Technology for near term CO reduction was satisfactory or marginally satisfactory. Considerable doubt exists if this technology will satisfy all far-term requirements.

  19. Greenhouse gas emission reductions from domestic anaerobic digesters linked with sustainable sanitation in rural China.

    PubMed

    Dhingra, Radhika; Christensen, Erick R; Liu, Yang; Zhong, Bo; Wu, Chang-Fu; Yost, Michael G; Remais, Justin V

    2011-03-15

    Anaerobic digesters provide clean, renewable energy (biogas) by converting organic waste to methane, and are a key part of China's comprehensive rural energy plan. Here, experimental and modeling results are used to quantify the net greenhouse gas (GHG) reduction from substituting a household anaerobic digester for traditional energy sources in Sichuan, China. Tunable diode laser absorption spectroscopy and radial plume mapping were used to estimate the mass flux of fugitive methane emissions from active digesters. Using household energy budgets, the net improvement in GHG emissions associated with biogas installation was estimated using global warming commitment (GWC) as a consolidated measure of the warming effects of GHG emissions from cooking. In all scenarios biogas households had lower GWC than nonbiogas households, by as much as 54%. Even biogas households with methane leakage exhibited lower GWC than nonbiogas households, by as much as 48%. Based only on the averted GHG emissions over 10 years, the monetary value of a biogas installation was conservatively estimated at US$28.30 ($16.07 ton(-1) CO(2)-eq), which is available to partly offset construction costs. The interaction of biogas installation programs with policies supporting improved stoves, renewable harvesting of biomass, and energy interventions with substantial health cobenefits are discussed.

  20. Greenhouse gas emission reductions from domestic anaerobic digesters linked with sustainable sanitation in rural China

    PubMed Central

    DHINGRA, RADHIKA; CHRISTENSEN, ERICK R.; LIU, YANG; ZHONG, BO; WU, CHANG-FU; YOST, MICHAEL G.; REMAIS, JUSTIN V.

    2013-01-01

    Anaerobic digesters provide clean, renewable energy (biogas) by converting organic waste to methane, and are a key part of China's comprehensive rural energy plan. Here, experimental and modeling results are used to quantify the net greenhouse gas (GHG) reduction from substituting a household anaerobic digester for traditional energy sources in Sichuan, China. Tunable diode laser absorption spectroscopy and radial plume mapping were used to estimate the mass flux of fugitive methane emissions from active digesters. Using household energy budgets, the net improvement in GHG emissions associated with biogas installation was estimated using global warming commitment (GWC) as a consolidated measure of the warming effects of GHG emissions from cooking. In all scenarios biogas households had lower GWC than non-biogas households, by as much as 54%. Even biogas households with methane leakage exhibited lower GWC than non-biogas households, by as much as 48%. Based only on the averted GHG emissions over 10 years, the monetary value of a biogas installation was conservatively estimated at US$28.30 ($16.07 ton−1 CO2-eq.), which is available to partly offset construction costs. The interaction of biogas installation programs with policies supporting improved stoves, renewable harvesting of biomass, and energy interventions with substantial health co-benefits, are discussed. PMID:21348471

  1. A perspective on cost-effectiveness of greenhouse gas reduction solutions in water distribution systems

    NASA Astrophysics Data System (ADS)

    Hendrickson, Thomas P.; Horvath, Arpad

    2014-01-01

    Water distribution systems (WDSs) face great challenges as aging infrastructures require significant investments in rehabilitation, replacement, and expansion. Reducing environmental impacts as WDSs develop is essential for utility managers and policy makers. This study quantifies the existing greenhouse gas (GHG) footprint of common WDS elements using life-cycle assessment (LCA) while identifying the greatest opportunities for emission reduction. This study addresses oversights of the related literature, which fails to capture several WDS elements and to provide detailed life-cycle inventories. The life-cycle inventory results for a US case study utility reveal that 81% of GHGs are from pumping energy, where a large portion of these emissions are a result of distribution leaks, which account for 270 billion l of water losses daily in the United States. Pipe replacement scheduling is analyzed from an environmental perspective where, through incorporating leak impacts, a tool reveals that optimal replacement is no more than 20 years, which is in contrast to the US average of 200 years. Carbon abatement costs (CACs) are calculated for different leak reduction scenarios for the case utility that range from -130 to 35 t-1 CO2(eq). Including life-cycle modeling in evaluating pipe materials identified polyvinyl chloride (PVC) and cement-lined ductile iron (DICL) as the Pareto efficient options, however; utilizing PVC presents human health risks. The model developed for the case utility is applied to California and Texas to determine the CACs of reducing leaks to 5% of distributed water. For California, annual GHG savings from reducing leaks alone (3.4 million tons of CO2(eq)) are found to exceed California Air Resources Board’s estimate for energy efficiency improvements in the state’s water infrastructure.

  2. Carbothermal Reduction of Quartz with Carbon from Natural Gas

    NASA Astrophysics Data System (ADS)

    Li, Fei; Tangstad, Merete

    2017-01-01

    Carbothermal reaction between quartz and two different carbons originating from natural gas were investigated in this paper. One of two carbons is the commercial carbon black produced from natural gas in a medium thermal production process. The other carbon is obtained from natural gas cracking at 1273 K (1000 °C) deposited directly on the quartz pellet. At the 1923 K (1650 °C) and CO atmosphere, the impact of carbon content, pellet structure, gas transfer, and heating rate are investigated in a thermo-gravimetric furnace. The reaction process can be divided into two steps: an initial SiC-producing step followed by a SiO-producing step. Higher carbon content and increased gas transfer improves the reaction rate of SiC-producing step, while the thicker carbon coating in carbon-deposited pellet hinders reaction rate. Better gas transfer of sample holder improves reaction rate but causes more SiO loss. Heating rate has almost no influence on reaction. Mass balance analysis shows that mole ratios between SiO2, free carbon, and SiC in the SiC-producing step and SiO-producing step in CO and Ar fit the reaction SiO2(s) + 3 C(s) = SiC(s) + 2 CO(g). SiC-particle and SiC-coating formation process in mixed pellet and carbon-deposited pellet are proposed. SiC whiskers formed in the voids of these two types of pellets.

  3. Carbothermal Reduction of Quartz with Carbon from Natural Gas

    NASA Astrophysics Data System (ADS)

    Li, Fei; Tangstad, Merete

    2017-04-01

    Carbothermal reaction between quartz and two different carbons originating from natural gas were investigated in this paper. One of two carbons is the commercial carbon black produced from natural gas in a medium thermal production process. The other carbon is obtained from natural gas cracking at 1273 K (1000 °C) deposited directly on the quartz pellet. At the 1923 K (1650 °C) and CO atmosphere, the impact of carbon content, pellet structure, gas transfer, and heating rate are investigated in a thermo-gravimetric furnace. The reaction process can be divided into two steps: an initial SiC-producing step followed by a SiO-producing step. Higher carbon content and increased gas transfer improves the reaction rate of SiC-producing step, while the thicker carbon coating in carbon-deposited pellet hinders reaction rate. Better gas transfer of sample holder improves reaction rate but causes more SiO loss. Heating rate has almost no influence on reaction. Mass balance analysis shows that mole ratios between SiO2, free carbon, and SiC in the SiC-producing step and SiO-producing step in CO and Ar fit the reaction SiO2(s) + 3 C(s) = SiC(s) + 2 CO(g). SiC-particle and SiC-coating formation process in mixed pellet and carbon-deposited pellet are proposed. SiC whiskers formed in the voids of these two types of pellets.

  4. Scenarios for Deep Carbon Emission Reductions from Electricity by 2050 in Western North America using the Switch Electric Power Sector Planning Model: California's Carbon Challenge Phase II, Volume II

    SciTech Connect

    Nelson, James; Mileva, Ana; Johnston, Josiah; Kammen, Daniel; Wei, Max; Greenblatt, Jeffrey

    2014-01-01

    This study used a state-of-the-art planning model called SWITCH for the electric power system to investigate the evolution of the power systems of California and western North America from present-day to 2050 in the context of deep decarbonization of the economy. Researchers concluded that drastic power system carbon emission reductions were feasible by 2050 under a wide range of possible futures. The average cost of power in 2050 would range between $149 to $232 per megawatt hour across scenarios, a 21 to 88 percent increase relative to a business-as-usual scenario, and a 38 to 115 percent increase relative to the present-day cost of power. The power system would need to undergo sweeping change to rapidly decarbonize. Between present-day and 2030 the evolution of the Western Electricity Coordinating Council power system was dominated by implementing aggressive energy efficiency measures, installing renewable energy and gas-fired generation facilities and retiring coal-fired generation. Deploying wind, solar and geothermal power in the 2040 timeframe reduced power system emissions by displacing gas-fired generation. This trend continued for wind and solar in the 2050 timeframe but was accompanied by large amounts of new storage and long-distance high-voltage transmission capacity. Electricity storage was used primarily to move solar energy from the daytime into the night to charge electric vehicles and meet demand from electrified heating. Transmission capacity over the California border increased by 40 - 220 percent by 2050, implying that transmission siting, permitting, and regional cooperation will become increasingly important. California remained a net electricity importer in all scenarios investigated. Wind and solar power were key elements in power system decarbonization in 2050 if no new nuclear capacity was built. The amount of installed gas capacity remained relatively constant between present-day and 2050, although carbon capture and sequestration was

  5. Anode shroud for off-gas capture and removal from electrolytic oxide reduction system

    DOEpatents

    Bailey, James L.; Barnes, Laurel A.; Wiedmeyer, Stanley G.; Williamson, Mark A.; Willit, James L.

    2014-07-08

    An electrolytic oxide reduction system according to a non-limiting embodiment of the present invention may include a plurality of anode assemblies and an anode shroud for each of the anode assemblies. The anode shroud may be used to dilute, cool, and/or remove off-gas from the electrolytic oxide reduction system. The anode shroud may include a body portion having a tapered upper section that includes an apex. The body portion may have an inner wall that defines an off-gas collection cavity. A chimney structure may extend from the apex of the upper section and be connected to the off-gas collection cavity of the body portion. The chimney structure may include an inner tube within an outer tube. Accordingly, a sweep gas/cooling gas may be supplied down the annular space between the inner and outer tubes, while the off-gas may be removed through an exit path defined by the inner tube.

  6. NO x Reduction in the Iron Ore Sintering Process with Flue Gas Recirculation

    NASA Astrophysics Data System (ADS)

    Yu, Zhiyuan; Fan, Xiaohui; Gan, Min; Chen, Xuling; Lv, Wei

    2017-02-01

    Flue gas recirculation (FGR) has been implemented for exhaust gas emissions reduction in iron ore sintering. However, the mechanism of NO x reduction through FGR is still unclear. In this paper, the laboratory pot-grate sintering test showed a 30% reduction in gas flow and 15.51% reduction in NO x emissions achieved with a 30% FGR ratio, and the sinter indexes almost matched those of the conventional process. In the sinter zone, NO-CO catalytic reduction occurs in the range of 500-900°C. When the sinter temperature is 700°C, the highest nitrogen reduction ratio (NRR) achieved is 8%; however, the NO x reduction is inhibited as the post-combustion of CO starts when the temperature increases beyond 700°C. NO x in the flue gas is mainly a product of the fuel combustion in the combustion zone, as the nitrogen conversion rate reaches 50-60%, because the N-containing intermediates exist during the fuel combustion. The existence of NO in the FGR gas inhibits the NO x generation from the fuel combustion, and the NO elimination—through the NO-carbon reaction—is significant in the combustion zone. The NRR in the combustion zone reaches a range of 18-20%.

  7. DEMONSTRATION BULLETIN: GAS-PHASE CHEMICAL REDUCTION - ECO LOGIC INTERNATIONAL, INC.

    EPA Science Inventory

    The patented Eco Logic Process employs a gas-phase reduction reaction of hydrogen with organic and chlorinated organic compounds at elevated temperatures to convert aqueous and oily hazardous contaminants into a hydrocarbon-rich gas product. After passing through a scrubber, the ...

  8. Projected changes of rainfall seasonality and dry spells in a high greenhouse gas emissions scenario

    NASA Astrophysics Data System (ADS)

    Pascale, Salvatore; Lucarini, Valerio; Feng, Xue; Porporato, Amilcare; ul Hasson, Shabeh

    2016-02-01

    In this diagnostic study we analyze changes of rainfall seasonality and dry spells by the end of the twenty-first century under the most extreme IPCC5 emission scenario (RCP8.5) as projected by twenty-four coupled climate models contributing to Coupled Model Intercomparison Project 5 (CMIP5). We use estimates of the centroid of the monthly rainfall distribution as an index of the rainfall timing and a threshold-independent, information theory-based quantity such as relative entropy (RE) to quantify the concentration of annual rainfall and the number of dry months and to build a monsoon dimensionless seasonality index (DSI). The RE is projected to increase, with high inter-model agreement over Mediterranean-type regions—southern Europe, northern Africa and southern Australia—and areas of South and Central America, implying an increase in the number of dry days up to 1 month by the end of the twenty-first century. Positive RE changes are also projected over the monsoon regions of southern Africa and North America, South America. These trends are consistent with a shortening of the wet season associated with a more prolonged pre-monsoonal dry period. The extent of the global monsoon region, characterized by large DSI, is projected to remain substantially unaltered. Centroid analysis shows that most of CMIP5 projections suggest that the monsoonal annual rainfall distribution is expected to change from early to late in the course of the hydrological year by the end of the twenty-first century and particularly after year 2050. This trend is particularly evident over northern Africa, southern Africa and western Mexico, where more than 90 % of the models project a delay of the rainfall centroid from a few days up to 2 weeks. Over the remaining monsoonal regions, there is little inter-model agreement in terms of centroid changes.

  9. New scenarios for hard-core interactions in a hadron resonance gas

    NASA Astrophysics Data System (ADS)

    Satarov, L. M.; Vovchenko, V.; Alba, P.; Gorenstein, M. I.; Stoecker, H.

    2017-02-01

    The equation of state of baryon-symmetric hadronic matter with hard-sphere interactions is studied. It is assumed that mesons M are pointlike, but baryons B and antibaryons B ¯ have the same hard-core radius rB. Three possibilities are considered: (1) the B B and B B ¯ interactions are the same; (2) baryons do not interact with antibaryons; (3) the B B ¯ , M B , and M B ¯ interactions are negligible. By choosing the parameter rB=0.3 -0.6 fm, we calculate the nucleon to pion ratio as a function of temperature and perform the fit of hadron yields measured in central Pb+Pb collisions at √{sN N}=2.76 TeV . New nontrivial effects in the interacting hadron resonance gas at temperatures 150 -200 MeV are found.

  10. Life-cycle analysis of energy use, greenhouse gas emissions, and water consumption in the 2016 MYPP algal biofuel scenarios

    SciTech Connect

    Frank, Edward; Pegallapati, Ambica K.; Davis, Ryan; Markham, Jennifer; Coleman, Andre; Jones, Sue; Wigmosta, Mark S.; Zhu, Yunhua

    2016-06-16

    The Department of Energy (DOE) Bioenergy Technologies Office (BETO) Multi-year Program Plan (MYPP) describes the bioenergy objectives pursued by BETO, the strategies for achieving those objectives, the current state of technology (SOT), and a number of design cases that explore cost and operational performance required to advance the SOT towards middle and long term goals (MYPP, 2016). Two options for converting algae to biofuel intermediates were considered in the MYPP, namely algal biofuel production via lipid extraction and algal biofuel production by thermal processing. The first option, lipid extraction, is represented by the Combined Algae Processing (CAP) pathway in which algae are hydrolyzed in a weak acid pretreatment step. The treated slurry is fermented for ethanol production from sugars. The fermentation stillage contains most of the lipids from the original biomass, which are recovered through wet solvent extraction. The process residuals after lipid extraction, which contain much of the original mass of amino acids and proteins, are directed to anaerobic digestion (AD) for biogas production and recycle of N and P nutrients. The second option, thermal processing, comprises direct hydrothermal liquefaction (HTL) of the wet biomass, separation of aqueous, gas, and oil phases, and treatment of the aqueous phase with catalytic hydrothermal gasification (CHG) to produce biogas and to recover N and P nutrients. The present report describes a life cycle analysis of energy use and greenhouse gas (GHG) emissions of the CAP and HTL options for the three scenarios just described. Water use is also reported. Water use during algal biofuel production comes from evaporation during cultivation, discharge to bleed streams to control pond salinity (“blowdown”), and from use during preprocessing and upgrading. For scenarios considered to date, most water use was from evaporation and, secondarily, from bleed streams. Other use was relatively small at the level of

  11. Pre-converted nitric oxide gas in catalytic reduction system

    DOEpatents

    Hsiao, M.C.; Merritt, B.T.; Penetrante, B.M.; Vogtlin, G.E.

    1999-04-06

    A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO{sub 2} in the presence of O{sub 2}. The second stage serves to convert NO{sub 2} to environmentally benign gases that include N{sub 2}, CO{sub 2}, and H{sub 2}O. By preconverting NO to NO{sub 2} in the first stage, the efficiency of the second stage for NO{sub x} reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO{sub 2} in the presence of O{sub 2} and includes platinum/alumina, e.g., Pt/Al{sub 2}O{sub 3} catalyst. A flow of hydrocarbons (C{sub x}H{sub y}) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO{sub 2} from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO{sub 2} to N{sub 2}, CO{sub 2}, and H{sub 2}O, and includes a {gamma}-Al{sub 2}O{sub 3}. The hydrocarbons and NO{sub x} are simultaneously reduced while passing through the second catalyst. 9 figs.

  12. Pre-converted nitric oxide gas in catalytic reduction system

    DOEpatents

    Hsiao, Mark C.; Merritt, Bernard T.; Penetrante, Bernardino M.; Vogtlin, George E.

    1999-01-01

    A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO.sub.2 in the presence of O.sub.2. The second stage serves to convert NO.sub.2 to environmentally benign gases that include N2, CO2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO.sub.2 in the presence of O.sub.2 and includes platinum/alumina, e.g., Pt/Al.sub.2 O.sub.3 catalyst. A flow of hydrocarbons (C.sub.x H.sub.y) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO.sub.2 from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO.sub.2 to N2, CO2, and H.sub.2 O, and includes a gamma-alumina .gamma.-Al.sub.2 O.sub.3. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the second catalyst.

  13. Enhancement of carbon dioxide reduction and methane production by an obligate anaerobe and gas dissolution device.

    PubMed

    Kim, Seungjin; Choi, Kwangkeun; Kim, Jong-Oh; Chung, Jinwook

    2016-01-25

    The use of gas dissolution devices to improve the efficiency of H2 dissolution has enhanced CO2 reduction and CH4 production. In addition, the nutrients that initially existed in anaerobic sludge were exhausted over time, and the activities of anaerobic microorganisms declined. When nutrients were artificially injected, CO2 reduction and CH4 production rates climbed. Thus, assuming that the activity of the obligatory anaerobic microorganisms is maintained, a gas dissolution device will further enhance the efficiency of CO2 reduction and CH4 production.

  14. Study for Reduction of Outgassing Property of Adsorbed Water Gas for Improved Surface Finished Titanium Material

    NASA Astrophysics Data System (ADS)

    Takeda, Masatoshi; Kurisu, Hiroki; Uchida, Takashi; Yamamoto, Setsuo; Ishizawa, Katsunobu; Nomura, Takeru; Eda, Takahiro; Murashige, Nobuyuki

    This paper addresses the development of the surface finishing for a titanium material and the study for the reduction of outgassing property of adsorbed water (H2O) molecules. Developed surface finishing is composed of the buffing for the reduction of the surface roughness and improved chemical polishing for the thick surface oxide layer compared with the chemical polishing so far. The surface roughness of the surface finished titanium material is reduced 35% and the thickness of the surface oxide layer increases by 30%. The total amount of thermal desorbed H2O gas for the new surface finished titanium is reduced 30%. It is considered that the origin for the decrease of the amount of desorption H2O gas is the reduction of the adsorption sites due to the decrease of the surface roughness and the reduction of adsorption energy of H2O gas due to the strong surface oxidation for a titanium material.

  15. Deep Reductions in Greenhouse Gas Emissions from the California Transportation Sector: Dynamics in Vehicle Fleet and Energy Supply Transitions to Achieve 80% Reduction in Emissions from 1990 Levels by 2050

    NASA Astrophysics Data System (ADS)

    Leighty, Wayne Waterman

    California's "80in50" target for reducing greenhouse gas emissions to 80 percent below 1990 levels by the year 2050 is based on climate science rather than technical feasibility of mitigation. As such, it raises four fundamental questions: is this magnitude of reduction in greenhouse gas emissions possible, what energy system transitions over the next 40 years are necessary, can intermediate policy goals be met on the pathway toward 2050, and does the path of transition matter for the objective of climate change mitigation? Scenarios for meeting the 80in50 goal in the transportation sector are modelled. Specifically, earlier work defining low carbon transport scenarios for the year 2050 is refined by incorporating new information about biofuel supply. Then transition paths for meeting 80in50 scenarios are modelled for the light-duty vehicle sub-sector, with important implications for the timing of action, rate of change, and cumulative greenhouse gas emissions. One aspect of these transitions -- development in the California wind industry to supply low-carbon electricity for plug-in electric vehicles -- is examined in detail. In general, the range of feasible scenarios for meeting the 80in50 target is narrow enough that several common themes are apparent: electrification of light-duty vehicles must occur; continued improvements in vehicle efficiency must be applied to improving fuel economy; and energy carriers must de-carbonize to less than half of the carbon intensity of gasoline and diesel. Reaching the 80in50 goal will require broad success in travel demand reduction, fuel economy improvements and low-carbon fuel supply, since there is little opportunity to increase emission reductions in one area if we experience failure in another. Although six scenarios for meeting the 80in50 target are defined, only one also meets the intermediate target of reducing greenhouse gas emissions to 1990 levels by the year 2020. Furthermore, the transition path taken to reach any

  16. Comparison of green-house gas emission reductions and landfill gas utilization between a landfill system and an incineration system.

    PubMed

    Haibin Han; Jisheng Long; Shude Li; Guangren Qian

    2010-04-01

    Electricity generation and greenhouse gas (GHG) reductions were researched by making comparisons between municipal solid waste (MSW) landfill and incineration systems with three different electricity generation efficiencies - 10%, 21%, and 24.7%. For MSW landfill systems, it is shown that the total electricity generation is 198,747 MWh, and the total GHG emission reduction is 1,386,081 tonne CO( 2) during a 21-year operation period. For incineration systems, the total electricity generation is 611,801 MWh, and the total GHG emission reduction is 1,339,158 tonne CO(2) during a 10-year operation period even if the electricity generation efficiency is only 10%. It is also shown that electricity generation increases quicker than the GHG emission reductions with the increase of electricity generation efficiency. However, incineration systems show great superiority in LFG utilisation and GHG emission reductions.

  17. Tsunami mitigation and preparedness activities in California: Chapter L in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Wilson, Rick; Miller, Kevin H.

    2013-01-01

    scenario-specific, tsunami evacuation “playbook” maps and guidance in-harbor hazard maps and offshore safety zones for potential boat evacuation during future distant source events; “probability-based” products for land-use planning under the California Seismic Hazard Mapping Act; and an expansion of real-time and post-tsunami field reconnaissance teams and information sharing through a state-wide clearinghouse. The state tsunami program has benefitted greatly from participation in the SAFRR tsunami scenario process, and hopes to continue this relationship with the U.S. Geological Survey to help improve tsunami preparedness in California.

  18. The economics of biomass for power and greenhouse gas reduction

    NASA Astrophysics Data System (ADS)

    Cameron, Jay Brooker

    The power cost and optimum plant size for power plants using straw fuel in western Canada was determined. The optimum size for agricultural residues is 450 MW (the largest single biomass unit judged feasible in this study), and the power cost is 50.30 MWh-1. If a larger biomass boiler could be built, the optiμm project size for straw would be 628 MW. For a market power price of 40 MWh-1 the cost of the GHG credit generated by a straw-fired plant is 11 tonne-1 CO2. Straw was evaluated as a possible supplement to the primary coal fuel at the Genesee power station in order to reduce the greenhouse gas (GHG) emissions intensity. Cofiring straw at the Genesee power station does not compete favorably with other GHG abatement technologies, even the lowest cost option is estimated at 22 tonne-1 CO2. The cost of transporting wood chips by truck and by pipeline as a water slurry is determined. The pipeline would be economical at large capacity (>0.5 M dry tonnes per year for a one way pipeline, and >1.25 M dry tonnes per year for a two way pipeline that returns the carrier fluid to the pipeline inlet), and at medium to long distances (>75 km (one way) and >470 km (two way) at a capacity of 2 M dry tonnes per year). Pipelining was determined to be unsuitable for combustion applications. Pipeline transport of corn is evaluated against a range of truck transport costs. At 20% solids, pipeline transport of corn stover costs less than trucking at capacities in excess of 1.4 M dry tonnes/yr when compared to a mid range of truck transport. Pipelining of corn stover gives the opportunity to conduct simultaneous transport and saccharification (STS) but would require a source of waste heat at the pipeline inlet in order to be economical. Transport of corn stover in multiple pipelines offers the opportunity to develop a large ethanol fermentation plant, avoiding some of the diseconomies of scale that arise from smaller plants whose capacities are limited by issues of truck congestion

  19. Carbothermal Reduction of Quartz in Methane-Hydrogen-Argon Gas Mixture

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Zhang, Guangqing; Tang, Kai; Ostrovski, Oleg; Tronstad, Ragnar

    2015-10-01

    Synthesis of silicon carbide (SiC) by carbothermal reduction of quartz in a CH4-H2-Ar gas mixture was investigated in a laboratory fixed-bed reactor in the temperature range of 1573 K to 1823 K (1300 °C to 1550 °C). The reduction process was monitored by an infrared gas analyser, and the reduction products were characterized by LECO, XRD, and SEM. A mixture of quartz-graphite powders with C/SiO2 molar ratio of 2 was pressed into pellets and used for reduction experiments. The reduction was completed within 2 hours under the conditions of temperature at or above 1773 K (1500 °C), methane content of 0.5 to 2 vol pct, and hydrogen content ≥70 vol pct. Methane partially substituted carbon as a reductant in the SiC synthesis and enhanced the reduction kinetics significantly. An increase in the methane content above 2 vol pct caused excessive carbon deposition which had a detrimental effect on the reaction rate. Hydrogen content in the gas mixture above 70 vol pct effectively suppressed the cracking of methane.

  20. EAF Gas Waste Heat Utilization and Discussion of the Energy Conservation and CO2 Emissions Reduction

    NASA Astrophysics Data System (ADS)

    Yang, Ling-zhi; Zhu, Rong; Ma, Guo-hong

    2016-02-01

    As a large number of energy was taken away by the high temperature furnace gas during the EAF smelting process, a huge economic and environmental benefits would obtained to recycle and utilize. In this paper, the energy of the EAF was analyzed theoretically with the hot metal ratio of 50%. Combined with the utilization of the gas waste heat during the scrap preheating, electricity generation, production of steam and production of coal gas processes, the effect of the energy saving and emission was calculated with comprehensive utilization of the high temperature furnace gas. An optimal scheme for utilization of the waste heat was proposed based on the calculation. The results show that the best way for energy saving and carbon reduction is the production of coal gas, while the optimal scheme for waste heat utilization is combined the production of coal gas with the scrap preheating, which will save 170 kWh/t of energy and decrease 57.88 kg/t of carbon emission. As hot metal ratio in EAF steelmaking is often more than 50%, which will produce more EAF gas waste heat, optimizing EAF gas waste heat utilization will have more obvious effect on energy saving and emission reduction.

  1. Landfill Gas Energy, A Guide to Developing and Implementing Greenhouse Gas Reduction Programs

    EPA Pesticide Factsheets

    This guide describes how local governments and communities can achieve energy, environmental, health, and economic benefits by using landfill gas (LFG) recovered from municipal solid waste landfills as a source of renewable energy.

  2. Formamide reaction network in gas phase and solution via a unified theoretical approach: Toward a reconciliation of different prebiotic scenarios

    PubMed Central

    Pietrucci, Fabio; Saitta, Antonino Marco

    2015-01-01

    Increasing experimental and theoretical evidence points to formamide as a possible hub in the complex network of prebiotic chemical reactions leading from simple precursors like H2, H2O, N2, NH3, CO, and CO2 to key biological molecules like proteins, nucleic acids, and sugars. We present an in-depth computational study of the formation and decomposition reaction channels of formamide by means of ab initio molecular dynamics. To this aim we introduce a new theoretical method combining the metadynamics sampling scheme with a general purpose topological formulation of collective variables able to track a wide range of different reaction mechanisms. Our approach is flexible enough to discover multiple pathways and intermediates starting from minimal insight on the systems, and it allows passing in a seamless way from reactions in gas phase to reactions in liquid phase, with the solvent active role fully taken into account. We obtain crucial new insight into the interplay of the different formamide reaction channels and into environment effects on pathways and barriers. In particular, our results indicate a similar stability of formamide and hydrogen cyanide in solution as well as their relatively facile interconversion, thus reconciling experiments and theory and, possibly, two different and competing prebiotic scenarios. Moreover, although not explicitly sought, formic acid/ammonium formate is produced as an important formamide decomposition byproduct in solution. PMID:26598679

  3. Gas souring by thermochemical sulfate reduction at 140{degrees}C

    SciTech Connect

    Worden, R.H.; Smalley, P.C.; Oxtoby, N.H.

    1995-06-01

    Natural gas in the Permian-Triassic Khuff Formation of Abu Dhabi contains variable amounts of H{sub 2}S. Gas souring occurred through thermochemical sulfate reduction of anhydrite by hydrocarbon gases. Sour gas is observed only in reservoirs hotter than a critical reaction temperature: 140{degrees}C. Petrographic examination of core from a wide depth range showed that the anhydrite reactant has been replaced by calcite reaction product only in samples deeper than 4300 m. Gas composition data show that only reservoirs deeper than 4300 m contain large quantities of H{sub 2}S (i.e., >10%). At present-day geothermal gradients, 4300 m is equivalent to 140{degrees}C. Fluid inclusion analysis of calcite reaction product has shown that calcite growth only became significant at temperatures greater than 140{degrees}C. Thus, three independent indicators all show that 140{degrees}C is the critical temperature above which gas souring by thermochemical sulfate reduction begins. The previously suggested lower temperature thresholds for other sour gas provinces (80-130{degrees}C) derive from gas composition data that may not allow adequately either for the reservoir temperature history or for the migration of gas generated at higher temperatures into present traps. Conversely, published proposals for higher threshold temperature (180-200{degrees}C) derive from short duration experimental data that are not easily extrapolated to geologically realistic temperatures and time scales. Therefore, the temperature of 140{degrees}C derived from our study of the Khuff Formation may be the best estimate of temperature required for in-situ thermochemical sulfate reduction to produce the high H{sub 2}S concentrations encountered in deep carbonate gas reservoirs.

  4. 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.

  5. Portal venous gas and cardiopulmonary arrest during pneumatic reduction of an ileocolic intussusception.

    PubMed

    Ryan, Mark L; Fields, Jonathan M; Sola, Juan E; Neville, Holly L

    2011-04-01

    We present the case of an 8-month-old infant with a small bowel obstruction secondary to an ileocolic intussusception without a pathologic lead point. During pneumatic reduction, the patient went into cardiopulmonary arrest, at which point portal venous gas (PVG) was visualized on radiography. Here we present-to our knowledge-the first reported case of PVG secondary to pneumatic reduction of an intussusception along with a review of the literature regarding known complications of pneumatic reduction and the etiologies of PVG.

  6. Simulation of drag reduction in superhydrophobic microchannels based on parabolic gas-liquid interfaces

    NASA Astrophysics Data System (ADS)

    Li, Chunxi; Zhang, Shuo; Xue, Quanxi; Ye, Xuemin

    2016-10-01

    Based on the given parabolic gas-liquid interfaces, a two-dimensional fluid flow in superhydrophobic microchannels is numerically simulated with the steady volume of fluid model in the laminar regime. The influence of several crucial parameters on drag reduction effect is discussed. The results indicate that the superhydrophobic microchannel containing rectangular cavities displays significant drag reduction effect. With increasing inlet velocity, the pressure drop reduction decreases slightly. Augments in the pressure drop reduction tend to be large with the increase of the cavity fraction or the decrease of the channel height. The results also reveal that the variation of the normalized slip length with the cavity fraction tends to be more dramatic when the channel height is smaller. As the parabolic height of the gas-liquid interface is enlarged, both the pressure drop reduction and the normalized slip length decrease linearly, while fRe increases linearly. The impact of the cavity depth on the normalized slip length, fRe, and the pressure drop reduction is minimal supposing the depth of the cavity is greater than 40% of its width. The drag reduction effect corresponding to the dovetail cavity model is the best, and the consequence of the rectangular, trapezoidal, and triangular cavity models sequentially worsens.

  7. COMPARISON OF WEST GERMAN AND U.S. FLUE GAS DESULFURIZATION AND SELECTIVE CATALYTIC REDUCTION COSTS

    EPA Science Inventory

    The report documents a comparison of the actual cost retrofitting flue gas desulfurization (FGD) and selective catalytic reduction (SCR) on Federal Republic of German (FRG) boilers to cost estimating procedures used in the U.S. to estimate the retrofit of these controls on U.S. b...

  8. ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE THERMAL DESORPTION UNIT - APPLICATIONS ANALYSIS REPORT

    EPA Science Inventory

    ELI ECO Logic International, Inc.'s Thermal Desorption Unit (TDU) is specifically designed for use with Eco Logic's Gas Phase Chemical Reduction Process. The technology uses an externally heated bath of molten tin in a hydrogen atmosphere to desorb hazardous organic compounds fro...

  9. Tapping Landfill Gas to Provide Significant Energy Savings and Greenhouse Gas Reductions - Case Study

    SciTech Connect

    2013-04-30

    BroadRock Renewables, LLC built two high efficiency electricity generating facilities that utilize landfill gas in California and Rhode Island. The two projects received a total of $25 million in U.S. Department of Energy funding from the American Recovery and Reinvestment Act (ARRA) of 2009. Private-sector cost share for the projects totaled approximately $186 million.

  10. Power plant emissions: particulate matter-related health damages and the benefits of alternative emission reduction scenarios

    SciTech Connect

    Schneider, C.

    2004-06-15

    This report estimates the avoidable health effects of each of a series of alternative regulatory scenarios for power plants, focusing on the adverse human health effects due to exposure to fine particulate matter (PM2.5) This report uses the same analytical methods that the U.S. Environmental Protection Agency used in 2003 to prepare an analysis of the potential health effects of the proposed Clear Skies Act (EPA 2003). This report conducts an analysis of the impacts in 2010 and 2020 of three policy alternatives to the proposed Clear Skies Act, The Jeffords/Lieberman/Collins 'The Clean Power Act', S. 366, and the EPA August 2001 Straw Proposal (one of several alternatives EPA analyzed prior to the announcement of the Clear Skies Initiative in 2002). The report also examines the health impacts associated with the total emissions from coal fired electricity generating units in 2010. Chapter 2 describes the emissions inventory estimates, and the changes in the emissions associated with each scenario analyzed. Chapter 3 describes the methods used to estimate changes in particulate matter concentrations. Chapter 4 describes general issues arising in estimating and valuing changes in adverse health effects associated with changes in particulate matter. Chapter 5 describes in some detail the methods used for estimating and valuing adverse health effects, and Chapter 6 presents the results of these analyses. Chapter 7 presents estimates of the impact of these alternative policy options on the PM non-attainment status. 117 refs., 21 figs., 32 tabs., 3 apps.

  11. Rate of the reduction of the iron oxides in red mud by hydrogen and converted gas

    NASA Astrophysics Data System (ADS)

    Teplov, O. A.; Lainer, Yu. A.

    2013-01-01

    The drying and gas reduction of the iron oxides in the red mud of bauxite processing are studied. It is shown that at most 25% of aluminum oxide are fixed by iron oxides in this red mud, and the other 75% are fixed by sodium aluminosilicates. A software package is developed to calculate the gas reduction of iron oxides, including those in mud. Small hematite samples fully transform into magnetite in hydrogen at a temperature below 300°C and a heating rate of 500 K/h, and complete reduction of magnetite to metallic iron takes place below 420°C. The densification of a thin red mud layer weakly affects the character and temperature range of magnetizing calcination, and the rate of reduction to iron decreases approximately twofold and reduction covers a high-temperature range (above 900°C). The substitution of a converted natural gas for hydrogen results in a certain delay in magnetite formation and an increase in the temperature of the end of reaction to 375°C. In the temperature range 450-550°C, the transformation of hematite into magnetite in red mud pellets 1 cm in diameter in a converted natural gas is 30-90 faster than the reduction of hematite to iron in hydrogen. The hematite-magnetite transformation rate in pellets is almost constant in the temperature range under study, and reduction occurs in a diffusion mode. At a temperature of ˜500°C, the reaction layer thickness of pellets in a shaft process is calculated to be ˜1 m at a converted-gas flow rate of 0.1 m3/(m2 s) and ˜2.5 m at a flow rate of 0.25 m3/(m2 s). The specific capacity of 1 m2 of the shaft cross section under these conditions is 240 and 600 t/day, respectively. The use of low-temperature gas reduction processes is promising for the development of an in situ optimum red mud utilization technology.

  12. Biological reduction of chlorate in a gas-lift reactor using hydrogen as an energy source.

    PubMed

    Kroon, A G M; van Ginkel, C G

    2004-01-01

    Chlorate release into the environment occurs with its manufacture and use. Biological reduction of chlorate offers an attractive option to decrease this release. A hydrogen gas-lift reactor with microorganisms attached to pumice particles was used for the treatment of wastewater containing high concentrations of chlorate. The microorganisms used chlorate as an electron acceptor and hydrogen gas as a reducing agent. After a start-up period of only a few weeks, chlorate reduction rates of 3.2 mmol L(-1) h(-1) were achieved during continuous operation. During this period, a hydrogen consumption rate of 14.5 mmol L(-1) h(-1) was observed. Complete removal of chlorate was maintained at hydraulic retention times of 6 h. This study clearly demonstrates the potential of hydrogen gas-lift bioreactors for the treatment of chlorate-containing waste streams.

  13. Effective methods of reduction of nitrogen oxides concentration during the natural gas combustion.

    PubMed

    Zajemska, Monika; Musiał, Dorota; Poskart, Anna

    2014-01-01

    This paper contains experimental research of NOx reduction in the combustion process with the primary methods, which were applied separately and in combined systems. In addition, the pulsation disturbance (PD) was applied, that is the gas stream was disturbed to increase the intensity of reagents mixing. An experimental stand was built to determine an influence of the following primary methods: air staging, reburning and flue gas recirculation on a reduction of NOx concentration. Experiments were carried out in three combinations: air staging with reburning, reburning with recirculation and air staging with recirculation. In all these cases, the PD was simultaneously applied. Researches were carried out in a quartz combustion chamber with laboratory equipment enabled to measure all the thermal and the chemical parameters of the process. The simultaneous application of primary methods causes additional increase in NOx reduction in certain systems.

  14. Strengthening Borehole Configuration from the Retaining Roadway for Greenhouse Gas Reduction: A Case Study

    PubMed Central

    Xue, Fei; Zhang, Nong; Feng, Xiaowei; Zheng, Xigui; Kan, Jiaguang

    2015-01-01

    A monitoring trial was carried out to investigate the effect of boreholes configuration on the stability and gas production rate. These boreholes were drilled from the retaining roadway at longwall mining panel 1111(1) of the Zhuji Coalmine, in China. A borehole camera exploration device and multiple gas parameter measuring device were adopted to monitor the stability and gas production rate. Research results show that boreholes 1~8 with low intensity and thin casing thickness were broken at the depth of 5~10 m along the casing and with a distance of 2~14 m behind the coal face, while boreholes 9~11 with a special thick-walled high-strength oil casing did not fracture during the whole extraction period. The gas extraction volume is closely related to the boreholes stability. After the stability of boreholes 9~11 being improved, the average gas flow rate increased dramatically 16-fold from 0.13 to 2.21 m3/min, and the maximum gas flow rate reached 4.9 m3/min. Strengthening boreholes configuration is demonstrated to be a good option to improve gas extraction effect. These findings can make a significant contribution to the reduction of greenhouse gas emissions from the coal mining industry. PMID:25633368

  15. Global Crop Yield Reductions due to Surface Ozone Exposure: Crop Production Losses and Economic Damage in 2000 and 2030 under Two Future Scenarios of O3 Pollution

    NASA Astrophysics Data System (ADS)

    Avnery, S.; Mauzerall, D. L.; Liu, J.; Horowitz, L. W.

    2011-12-01

    Field studies demonstrate that exposure to elevated concentrations of surface ozone (O3) may cause substantial reductions in the agricultural yields of many crops. As emissions of O3 precursors rise in many parts of the world over the next few decades, yield reductions from O3 exposure may increase the challenges of feeding a global population projected to grow from approximately 6 to 8 billion people between 2000 and 2030. This study estimates global yield reductions of three key staple crops (soybean, maize, and wheat) due to surface ozone exposure in 2000 and 2030 according to two trajectories of O3 pollution: the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) A2 and B1 storylines, which represent upper- and lower-boundary projections, respectively, of most O3 precursor emissions in 2030. Our results indicate that year 2000 O3-induced global yield reductions ranged, depending on the O3 exposure metric used, from 3.9-15% for wheat, 8.5-14% for soybean, and 2.2-5.5% for maize. Global crop production losses totaled 79-121 million metric tons, worth 11-18 billion annually (USD2000). In the 2030-A2 scenario we find global O3-induced yield loss of wheat to be 5.4-26% (a further reduction in yield of +1.5-10% from year 2000 values), 15-19% for soybean (reduction of +0.9-11%), and 4.4-8.7% for maize (reduction of +2.1-3.2%) depending on the metric used, with total global agricultural losses worth 17-35 billion USD2000 annually (an increase of +6-17 billion in losses from 2000). Under the 2030-B1 scenario, we project less severe but still substantial reductions in yields: 4.0-17% for wheat (a further decrease in yield of +0.1-1.8% from 2000), 9.5-15% for soybean (decrease of +0.7-1.0%), and 2.5-6.0% for maize (decrease of+ 0.3-0.5%), with total losses worth 12-21 billion annually (an increase of +$1-3 billion in losses from 2000). Because our analysis uses crop data from the year 2000, which likely underestimates agricultural

  16. Environmental Distributions of Benzo[a]pyrene in China: Current and Future Emission Reduction Scenarios Explored Using a Spatially Explicit Multimedia Fate Model.

    PubMed

    Zhu, Ying; Tao, Shu; Price, Oliver R; Shen, Huizhong; Jones, Kevin C; Sweetman, Andrew J

    2015-12-01

    SESAMe v3.0, a spatially explicit multimedia fate model with 50 × 50 km(2) resolution, has been developed for China to predict environmental concentrations of benzo[a]pyrene (BaP) using an atmospheric emission inventory for 2007. Model predictions are compared with environmental monitoring data obtained from an extensive review of the literature. The model performs well in predicting multimedia concentrations and distributions. Predicted concentrations are compared with guideline values; highest values with some exceedances occur mainly in the North China Plain, Mid Inner Mongolia, and parts of three northeast provinces, Xi'an, Shanghai, and south of Jiangsu province, East Sichuan Basin, middle of Guizhou and Guangzhou. Two potential future scenarios have been assessed using SESAMe v3.0 for 2030 as BaP emission is reduced by (1) technological improvement for coal consumption in energy production and industry sectors in Scenario 1 (Sc1) and (2) technological improvement and control of indoor biomass burning for cooking and indoor space heating and prohibition of open burning of biomass in 2030 in Scenario 2 (Sc2). Sc2 is more efficient in reducing the areas with exceedance of guideline values. Use of SESAMe v3.0 provides insights on future research needs and can inform decision making on options for source reduction.

  17. Can Switching from Coal to Shale Gas Bring Net Carbon Reductions to China?

    PubMed

    Qin, Yue; Edwards, Ryan; Tong, Fan; Mauzerall, Denise L

    2017-03-07

    To increase energy security and reduce emissions of air pollutants and CO2 from coal use, China is attempting to duplicate the rapid development of shale gas that has taken place in the United States. This work builds a framework to estimate the lifecycle greenhouse gas (GHG) emissions from China's shale gas system and compares them with GHG emissions from coal used in the power, residential, and industrial sectors. We find the mean lifecycle carbon footprint of shale gas is about 30-50% lower than that of coal in all sectors under both 20 year and 100 year global warming potentials (GWP20 and GWP100). However, primarily due to large uncertainties in methane leakage, the upper bound estimate of the lifecycle carbon footprint of shale gas in China could be approximately 15-60% higher than that of coal across sectors under GWP20. To ensure net GHG emission reductions when switching from coal to shale gas, we estimate the breakeven methane leakage rates to be approximately 6.0%, 7.7%, and 4.2% in the power, residential, and industrial sectors, respectively, under GWP20. We find shale gas in China has a good chance of delivering air quality and climate cobenefits, particularly when used in the residential sector, with proper methane leakage control.

  18. Risk-based decision making for staggered bioterrorist attacks : resource allocation and risk reduction in "reload" scenarios.

    SciTech Connect

    Lemaster, Michelle Nicole; Gay, David M.; Ehlen, Mark Andrew; Boggs, Paul T.; Ray, Jaideep

    2009-10-01

    Staggered bioterrorist attacks with aerosolized pathogens on population centers present a formidable challenge to resource allocation and response planning. The response and planning will commence immediately after the detection of the first attack and with no or little information of the second attack. In this report, we outline a method by which resource allocation may be performed. It involves probabilistic reconstruction of the bioterrorist attack from partial observations of the outbreak, followed by an optimization-under-uncertainty approach to perform resource allocations. We consider both single-site and time-staggered multi-site attacks (i.e., a reload scenario) under conditions when resources (personnel and equipment which are difficult to gather and transport) are insufficient. Both communicable (plague) and non-communicable diseases (anthrax) are addressed, and we also consider cases when the data, the time-series of people reporting with symptoms, are confounded with a reporting delay. We demonstrate how our approach develops allocations profiles that have the potential to reduce the probability of an extremely adverse outcome in exchange for a more certain, but less adverse outcome. We explore the effect of placing limits on daily allocations. Further, since our method is data-driven, the resource allocation progressively improves as more data becomes available.

  19. Reduction of NOx and PM in marine diesel engine exhaust gas using microwave plasma

    NASA Astrophysics Data System (ADS)

    Balachandran, W.; FInst, P.; Manivannan, N.; Beleca, R.; Abbod, M.

    2015-10-01

    Abatement of NOx and particulate matters (PM) of marine diesel exhaust gas using microwave (MW) non-thermal plasma is presented in this paper. NOx mainly consist of NO and less concentration of NO2 in a typical two stoke marine diesel engine and microwave plasma generation can completely remove NO. MW was generated using two 2kW microwave sources and a saw tooth passive electrode. Passive electrode was used to generate high electric field region within microwave environment where high energetic electrons (1-3eV) are produced for the generation of non-thermal plasma (NTP). 2kW gen-set diesel exhaust gas was used to test our pilot-scale MW plasma reactor. The experimental results show that almost 100% removal of NO is possible for the exhaust gas flow rate of 60l/s. It was also shown that MW can significantly remove soot particles (PM, 10nm to 365nm) entrained in the exhaust gas of 200kW marine diesel engine with 40% engine load and gas flow rate of 130l/s. MW without generating plasma showed reduction up to 50% reduction of PM and with the plasma up to 90% reduction. The major challenge in these experiments was that igniting the desired plasma and sustaining it with passive electrodes for longer period (10s of minutes) as it required fine tuning of electrode position, which was influenced by many factors such as gas flow rate, geometry of reactor and MW power.

  20. Improving greenhouse gas reduction calculations for bioenergy systems: Incremental life cycle analysis

    NASA Astrophysics Data System (ADS)

    Ney, Richard A.

    There are many scales that can be employed to calculate net greenhouse gas emissions from bioenergy systems, ranging from single point source (stack gas) measurement, to full, multi-layered life cycle analyses considering all of the inputs and outputs throughout the economy. At an appropriate scale within these extremes, a method can be selected to support verification activities related to project-based trading of greenhouse gas emissions. The boundaries of the analysis must be carefully selected in order to meet the twin goals of the verification activity: (1) to meet scientific standards for emission balance quantification; and (2) to meet cost-effectiveness criteria of the emission trading community. The Incremental Life Cycle Analysis (ILCA) methodology is proposed and implemented for the quantification of greenhouse gas emission reductions arising from substitution of switchgrass for coal in electricity generation. The method utilizes an incremental progression through the fuel life cycle, evaluating each level of the life cycle for the quality the emission estimate produced. The method also reviews the scientific uncertainty underlying emission estimation procedures so that areas of relative weakness can be targeted and improved. The ILCA methodology is applied to the Chariton Valley Biomass Project (CVBP) for case study and evaluation. The CVBP is seeking to replace coal combustion in an existing 650-MW generation facility with switchgrass, cofired at a rate of 5 percent switchgrass to 95 percent coal. When the project reaches full capacity, the ILCA estimates that 239 pounds of carbon dioxide-equivalent (CO2-eq) emissions will be reduced and/or removed from the atmosphere for every million Btu of switchgrass utilized, generating annual greenhouse gas reductions of 305,000 tons CO2-eq, leading to revenue for the project totaling over $1.5 million annually through trading of greenhouse gas emission reduction credits.

  1. Simultaneous Measurement of Acetylene Reduction and Respiratory Gas Exchange of Attached Root Nodules 1

    PubMed Central

    Winship, Lawrence J.; Tjepkema, John D.

    1982-01-01

    A method was developed for the simultaneous measurement of acetylene reduction, carbon dioxide evolution and oxygen uptake by individual root nodules of intact nitrogen-fixing plants (Alnus rubra Bong.). The nodules were enclosed in a temperature-controlled leak-tight cuvette. Assay gas mixtures were passed through the cuvette at a constant, known flow rate and gas exchange was measured by the difference between inlet and outlet gas compositions. Gas concentrations were assayed by a combination of an automated gas chromatograph and a programmable electronic integrator. Carbon dioxide and ethylene evolution were determined with a coefficient of variation which was less than 2%, whereas the coefficient of variation for oxygen uptake measurements was less than 5%. Nodules subjected to repeated removal from and reinsertion into the cuvette and to long exposures of 10% v/v acetylene showed no irreversible decline in respiration or acetylene reduction. This system offers long-term stability and freedom from disturbance artifacts plus the ability to monitor continuously, rapidly and specifically the changes in root nodule activity caused by environmental perturbation. PMID:16662496

  2. Gas-based reduction of vanadium titano-magnetite concentrate: behavior and mechanisms

    NASA Astrophysics Data System (ADS)

    Sui, Yu-lei; Guo, Yu-feng; Jiang, Tao; Xie, Xiao-lin; Wang, Shuai; Zheng, Fu-qiang

    2017-01-01

    The reduction of vanadium titano-magnetite pellets by H2-CO at temperatures from 850 to 1050°C was investigated in this paper. The influences of pre-oxidation treatment, reduction temperature, and V_{H_2} + V_{CO} on the metallization degree were studied. The results showed that pre-oxidation played a substantial role in the reduction of vanadium titano-magnetite pellets. During the reduction process, the metallization degree increased with increasing temperature and increasing V_{H_2} V_{CO}. The phase transformation of pre-oxidized vanadium titano-magnetite pellets during the reduction process under an H2 atmosphere and a CO atmosphere was discussed, and the reduced samples were analyzed by scanning electron microscopy (SEM) in conjunction with back scatter electron (BSE) imaging. The results show that the difference in thermodynamic reducing ability between H2 and CO is not the only factor that leads to differences in the reduction results obtained using different atmospheres. Some of Fe3- x Ti x O4 cannot be reduced under a CO atmosphere because of the densification of particles' structure and because of the enrichment of Mg in unreacted cores. By contrast, a loose structure of particles was obtained when the pellets were reduced under an H2 atmosphere and this structure decreased the resistance to gas diffusion. Moreover, the phenomenon of Mg enrichment in unreacted cores disappeared during H2 reduction. Both the lower resistance to gas diffusion and the lack of Mg enrichment facilitated the reduction of vanadium titano-magnetite.

  3. Breakdown voltage reduction by field emission in multi-walled carbon nanotubes based ionization gas sensor

    SciTech Connect

    Saheed, M. Shuaib M.; Muti Mohamed, Norani; Arif Burhanudin, Zainal

    2014-03-24

    Ionization gas sensors using vertically aligned multi-wall carbon nanotubes (MWCNT) are demonstrated. The sharp tips of the nanotubes generate large non-uniform electric fields at relatively low applied voltage. The enhancement of the electric field results in field emission of electrons that dominates the breakdown mechanism in gas sensor with gap spacing below 14 μm. More than 90% reduction in breakdown voltage is observed for sensors with MWCNT and 7 μm gap spacing. Transition of breakdown mechanism, dominated by avalanche electrons to field emission electrons, as decreasing gap spacing is also observed and discussed.

  4. Experimental and Modeling Study on Reduction of Hematite Pellets by Hydrogen Gas

    NASA Astrophysics Data System (ADS)

    Kazemi, Mania; Pour, Mohsen Saffari; Sichen, Du

    2017-04-01

    Gaseous reduction by hydrogen was performed for three types of hematite pellets, two from industry and one prepared in the laboratory. The reduction mechanisms of the pellets were studied based on the morphologies of the partially reduced samples. Two mechanisms were found, the mechanisms of the two types of industrial pellets being very similar. The degree of reduction was followed as a function of time for each type of pellets. On the basis of the reaction mechanism of the industrial pellets, a mathematical model was developed. As a pioneer effort, the model combined the computational fluid dynamics approach for the flow and mass transfer in the gas phase with model of gas diffusion in the solid phase as well as the description of the chemical reaction at the reaction sites. The calculation results agreed well with the experimentally obtained reduction curves. The present work also emphasized the importance of evaluation of the reduction mechanisms and the properties of different types of iron ore pellets prior to developing a process model. While the present approach has established a good foundation for the dynamic modeling of the shaft reactor, more efforts are required to accomplish a realistic process model.

  5. Experimental and Modeling Study on Reduction of Hematite Pellets by Hydrogen Gas

    NASA Astrophysics Data System (ADS)

    Kazemi, Mania; Pour, Mohsen Saffari; Sichen, Du

    2017-01-01

    Gaseous reduction by hydrogen was performed for three types of hematite pellets, two from industry and one prepared in the laboratory. The reduction mechanisms of the pellets were studied based on the morphologies of the partially reduced samples. Two mechanisms were found, the mechanisms of the two types of industrial pellets being very similar. The degree of reduction was followed as a function of time for each type of pellets. On the basis of the reaction mechanism of the industrial pellets, a mathematical model was developed. As a pioneer effort, the model combined the computational fluid dynamics approach for the flow and mass transfer in the gas phase with model of gas diffusion in the solid phase as well as the description of the chemical reaction at the reaction sites. The calculation results agreed well with the experimentally obtained reduction curves. The present work also emphasized the importance of evaluation of the reduction mechanisms and the properties of different types of iron ore pellets prior to developing a process model. While the present approach has established a good foundation for the dynamic modeling of the shaft reactor, more efforts are required to accomplish a realistic process model.

  6. Simulating the Effect of Alternative Climate Change Scenarios on Pollutant Loading Reduction Requirements for Meeting Water Quality Standards Under USEPA's Total Maximum Daily Load Program

    NASA Astrophysics Data System (ADS)

    Gronewold, A. D.; Alameddine, I.; Anderson, R.; Wolpert, R.; Reckhow, K.

    2008-12-01

    The United States Environmental Protection Agency (USEPA) total maximum daily load (TMDL) program requires that individual states assess the condition of surface waters and identify those which fail to meet ambient water quality standards. Waters failing to meet those standards must have a TMDL assessment conducted to determine the maximum allowable pollutant load which can enter the water without violating water quality standards. While most of the nearly 30,000 TMDL assessments completed since 1995 use mechanistic or empirical water quality models to forecast water quality conditions under alternative pollutant loading reduction scenarios, few, if any, also simulate water quality conditions under alternative climate change scenarios. As a result, model-based loading reduction requirements (which serve as the cornerstone for implementing water resource management plans, and initiating environmental management infrastructure projects), believed to improve water quality in impaired waters and reinstate their designated use, may misrepresent the actual required reduction when future climate change scenarios are considered. For example, recent research indicates a potential long term future increase in both the number of days between, and the intensity of, individual precipitation events. In coastal terrestrial and aquatic ecosystems, such climate conditions could lead to an increased accumulation of pollutants on the landscape between precipitation events, followed by a washoff event with a relatively high pollutant load. On the other hand, anticipated increases in average temperature and evaporation rate might not only reduce effective rainfall rates (resulting in less energy for transporting pollutants from the landscape) but also reduce the tidal exchange ratio in shallow estuaries (many of which are valuable recreational, commercial, and aesthetic natural resources). Here, we develop and apply a comprehensive watershed-scale model for simulating water quality in

  7. Determination of greenhouse gas emission reductions from sewage sludge anaerobic digestion in China.

    PubMed

    Liu, H-T; Kong, X-J; Zheng, G-D; Chen, C-C

    2016-01-01

    Sewage sludge is a considerable source of greenhouse gas (GHG) emission in the field of organic solid waste treatment and disposal. In this case study, total GHG emissions from sludge anaerobic digestion, including direct and indirect emissions as well as replaceable emission reduction due to biogas being reused instead of natural gas, were quantified respectively. The results indicated that no GHG generation needed to be considered during the anaerobic digestion process. Indirect emissions were mainly from electricity and fossil fuel consumption on-site and sludge transportation. Overall, the total GHG emission owing to relative subtraction from anaerobic digestion rather than landfill, and replaceable GHG reduction caused by reuse of its product of biogas, were quantified to be 0.7214 (northern China) or 0.7384 (southern China) MgCO2 MgWS(-1) (wet sludge).

  8. Determination of gas phase protein ion densities via ion mobility analysis with charge reduction.

    PubMed

    Maisser, Anne; Premnath, Vinay; Ghosh, Abhimanyu; Nguyen, Tuan Anh; Attoui, Michel; Hogan, Christopher J

    2011-12-28

    We use a charge reduction electrospray (ESI) source and subsequent ion mobility analysis with a differential mobility analyzer (DMA, with detection via both a Faraday cage electrometer and a condensation particle counter) to infer the densities of single and multiprotein ions of cytochrome C, lysozyme, myoglobin, ovalbumin, and bovine serum albumin produced from non-denaturing (20 mM aqueous ammonium acetate) and denaturing (1 : 49.5 : 49.5, formic acid : methanol : water) ESI. Charge reduction is achieved through use of a Po-210 radioactive source, which generates roughly equal concentrations of positive and negative ions. Ions produced by the source collide with and reduce the charge on ESI generated drops, preventing Coulombic fissions, and unlike typical protein ESI, leading to gas-phase protein ions with +1 to +3 excess charges. Therefore, charge reduction serves to effectively mitigate any role that Coulombic stretching may play on the structure of the gas phase ions. Density inference is made via determination of the mobility diameter, and correspondingly the spherical equivalent protein volume. Through this approach it is found that for both non-denaturing and denaturing ESI-generated ions, gas-phase protein ions are relatively compact, with average densities of 0.97 g cm(-3) and 0.86 g cm(-3), respectively. Ions from non-denaturing ESI are found to be slightly more compact than predicted from the protein crystal structures, suggesting that low charge state protein ions in the gas phase are slightly denser than their solution conformations. While a slight difference is detected between the ions produced with non-denaturing and denaturing ESI, the denatured ions are found to be much more dense than those examined previously by drift tube mobility analysis, in which charge reduction was not employed. This indicates that Coulombic stretching is typically what leads to non-compact ions in the gas-phase, and suggests that for gas phase

  9. Fundamental limits on gas-phase chemical reduction of NOx in a plasma

    SciTech Connect

    Penetrante, B.M.; Hsiao, M.C.; Merritt, B.T.; Vogtlin, G.E.

    1997-12-31

    In the plasma, the electrons do not react directly with the NOx molecules. The electrons collide mainly with the background gas molecules like N{sub 2}, O{sub 2} and H{sub 2}O. Electron impact on these molecules result partly in dissociation reactions that produce reactive species like N, O and OH. The NOx in the engine exhaust gas initially consist mostly of NO. The ground state nitrogen atom, N, is the only species that could lead to the chemical reduction of NO to N{sub 2}. The O radical oxidizes NO to NO{sub 2} leaving the same amount of NOx. The OH radical converts NO{sub 2} to nitric acid. Acid products in the plasma can easily get adsorbed on surfaces in the plasma reactor and in the pipes. When undetected, the absence of these oxidation products can often be mistaken for chemical reduction of NOx. In this paper the authors will examine the gas-phase chemical reduction of NOx. They will show that under the best conditions, the plasma can chemically reduce 1.6 grams of NOx per brake-horsepower-hour [g(NOx)/bhp-hr] when 5% of the engine output energy is delivered to the plasma.

  10. Estimates of associated outdoor particulate matter health risk and costs reductions from alternative building, ventilation and filtration scenarios.

    PubMed

    Sultan, Zuraimi M

    2007-05-01

    Although many studies have reported calculations of outdoor particulate matter (PM) associated externalities using ambient data, there is little information on the role buildings, their ventilation and filtration play. This study provides the framework to evaluate the health risk and cost reduction of building, ventilation and filtration strategies from outdoor PM pollution on a nationwide level and applied it to a case study in Singapore. Combining Indoor Air Quality (IAQ) and time weighted exposure models, with established concentration-response functions and monetary valuation methods, mortality and morbidity effects of outdoor PM on the population of Singapore under different building, ventilation and filtration strategies were estimated. Different interventions were made to compare the effects from the current building conditions. The findings demonstrate that building protection effect reduced approximately half the attributable health cases amounting to US$17.7 billion due to PM pollution when compared to levels computed using outdoor data alone. For residential buildings, nationwide adoption of natural ventilation from current state is associated with 28% higher cases of mortality and 13 to 38% higher cases for different morbidities, amounting to US$6.7 billion. The incurred cost is negligible compared to energy costs of air-conditioning. However, nationwide adoption of closed residence and air-conditioning are associated with outcomes including fewer mortality (10 and 6% respectively), fewer morbidities (8 and 4% respectively) and economic savings of US$1.5 and 0.9 billion respectively. The related savings were about a factor of 9 the energy cost for air-conditioning. Nationwide adoption of mechanical ventilation and filtration from current natural ventilation in schools is associated with fewer asthma hospital admissions and exacerbations; although the economic impact is not substantial. Enhanced workplace filtration reduces the mortality and morbidity

  11. Immobilization conditions of ketoreductase on enantioselective reduction in a gas-solid bioreactor.

    PubMed

    Nagayama, Kazuhito; Spiess, Antje C; Büchs, Jochen

    2010-05-01

    The immobilization conditions of commercial ketoreductase for continuous enantioselective reduction in the gas-phase reaction were investigated with respect to the immobilization efficiency (residual activity and protein loading) and the gas-phase reaction efficiency (initial reaction rate, half-life, and enantioselectivity). For the analyses, ketoreductase was first immobilized by physical deposition on glass supports and the reduction of 2-butanone to (S)-2-butanol with the concomitant regeneration of NADH by 2-propanol was used as a model reaction. The optimal conditions of enzyme immobilization were obtained using an absolute pressure of 100 hPa for drying, a pH between 6.5 and 7.0, and a buffer concentration of 50 mM. The buffer concentration in particular had a strong effect on both the enzyme activity and enantioselectivity. Under optimal immobilization conditions, the thermostability of ketoreductase in the gas-phase system was enhanced compared to the aqueous-phase system, while the enantioselectivity was successfully maintained at a level identical to that of the native enzyme. These results indicate that the gas-phase reaction has a great potential for industrial production of chiral compounds, but requires careful optimization of immobilization conditions for the reaction to progress effectively.

  12. Hg2+ reduction and re-emission from simulated wet flue gas desulfurization liquors.

    PubMed

    Wo, Jingjing; Zhang, Meng; Cheng, Xiaoya; Zhong, Xiaohang; Xu, Jiang; Xu, Xinhua

    2009-12-30

    In this study, considering that Hg(2+) in wet flue gas desulfurization (FGD) systems can easily be reduced and then released into atmosphere, causing secondary pollution, the researches about Hg(2+) reduction and Hg(0) re-emission mechanism were carried out. The effects of several experimental parameters on the reduction were studied, including initial pH, temperature, and concentrations of Cl(-) and S(IV). Our experimental results indicated that Cl(-) had a restraining effect on the Hg(2+) reduction and Hg(0) re-emission, after 24h reaction, only 20.5% of Hg(2+) was reduced with 100mM Cl(-) in simulated desulfurization solution. Cl(-) can slow Hg(2+) reduction and Hg(0) re-emissions dramatically through changing reaction mechanism, with formation of new intermediate: ClHgSO(3)(-), which can decompose to Hg(0), but much more slowly than Hg(SO(3))(2)(2-) or HgSO(3). Simulating the conditions of the practical application (initial pH 5, T=50 degrees C, S(IV)=5 mM, Cl(-)=100 mM), we also found that Ca(2+), NO(3)(-), F(-), etc. all had obvious effects on reduction rates. Based on the material balance and characteristic of the reactants, the reduction emission mechanism of Hg(2+) has been established, providing theoretical basis for industrial application of mercury control in wet FGD systems.

  13. Fundamental study of reduction graphene oxide by sodium borohydride for gas sensor application

    NASA Astrophysics Data System (ADS)

    Muda, M. R.; Ramli, Muhammad M.; Isa, Siti S. Mat; Jamlos, M. F.; Murad, S. A. Z.; Norhanisah, Z.; Isa, M. Mohamad; Kasjoo, S. R.; Ahmad, N.; Nor, N. I. M.; Khalid, N.

    2017-03-01

    The efficient reduction of graphene oxide (rGO) was performed using Sodium Borohydride (NaBH4). These reduction approaches remove the majority of the oxygen-containing functional groups at the basal plane and surface of graphene oxide sheets. Structural and physiochemical properties of the GO were investigated with help of Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), and Ultraviolet-Visible-Near infrared (UV-Vis-NIR). The effects of the chemical reduction on a GO surface were analyzed using a Semiconductor Parameter Analyzer (SPA) in order to obtain the electrical resistance measurement. It was found that the resistance of reduced graphene oxide was greatly reduced when compared to the condition of before reduction process. Then, the formation of uniform thin film of rGO sheets was produced using vacuum filtration method in order to fabricate a gas sensor. In this project, plastic was used as a substrate. The sensor was then being exposed to NO2 gas at room temperature in order to demonstrate the sensing ability of rGO.

  14. Microbial reduction of sulfate injected to gas condensate plumes in cold groundwater

    NASA Astrophysics Data System (ADS)

    Van Stempvoort, Dale R.; Armstrong, James; Mayer, Bernhard

    2007-07-01

    Despite a rapid expansion over the past decade in the reliance on intrinsic bioremediation to remediate petroleum hydrocarbon plumes in groundwater, significant research gaps remain. Although it has been demonstrated that bacterial sulfate reduction can be a key electron accepting process in many petroleum plumes, little is known about the rate of this reduction process in plumes derived from crude oil and gas condensates at cold-climate sites (mean temperature < 10 °C), and in complex hydrogeological settings such as silt/clay aquitards. In this field study, sulfate was injected into groundwater contaminated by gas condensate plumes at two petroleum sites in Alberta, Canada to enhance in-situ bioremediation. In both cases the groundwater near the water table had low temperature (6-9 °C). Monitoring data had provided strong evidence that bacterial sulfate reduction was a key terminal electron accepting process (TEAP) in the natural attenuation of dissolved hydrocarbons at these sites. At each site, water with approximately 2000 mg/L sulfate and a bromide tracer was injected into a low-sulfate zone within a condensate-contaminant plume. Monitoring data collected over several months yielded conservative estimates for sulfate reduction rates based on zero-order kinetics (4-6 mg/L per day) or first-order kinetics (0.003 and 0.01 day - 1 ). These results favor the applicability of in-situ bioremediation techniques in this region, under natural conditions or with enhancement via sulfate injection.

  15. Reduction of gas flow into a hollow cathode ion source for a neutral beam injector

    NASA Astrophysics Data System (ADS)

    Tanaka, Shigeru; Akiba, Masato; Arakawa, Yoshihiro; Horiike, Hiroshi; Sakuraba, Junji

    1982-07-01

    Experimental studies have been made on the reduction of the gas flow rate into ion sources which utilize a hollow cathode. The electron emitter of the hollow cathode was a barium oxide impregnated porous tungsten tube. The hollow cathode was mounted to a circular or a rectangular bucket source and the following results were obtained. There was a tendency for the minimum gas flow rate for the stable source operation to decrease with increasing orifice diameter of the hollow cathode up to 10 mm. A molybdenum button with an appropriate diameter set in front of the orifice reduced the minimum gas flow rate to one half of that without button. An external magnetic field applied antiparallel to the field generated by the heater current stabilized the discharges and reduced the minimum gas flow rate to one half of that without field. Combination of the button and the antiparallel field reduced the minimum gas flow rate from the initial value (9.5 Torr 1/s) to 2.4 Torr 1/s. The reason for these effects was discussed on the basis of the theory for arc starvation.

  16. Reduction of prostate intrafraction motion using gas-release rectal balloons

    SciTech Connect

    Su Zhong; Zhao Tianyu; Li Zuofeng; Hoppe, Brad; Henderson, Randy; Mendenhall, William; Nichols, R. Charles; Marcus, Robert; Mendenhall, Nancy

    2012-10-15

    Purpose: To analyze prostate intrafraction motion using both non-gas-release (NGR) and gas-release (GR) rectal balloons and to evaluate the ability of GR rectal balloons to reduce prostate intrafraction motion. Methods: Twenty-nine patients with NGR rectal balloons and 29 patients with GR balloons were randomly selected from prostate patients treated with proton therapy at University of Florida Proton Therapy Institute (Jacksonville, FL). Their pretreatment and post-treatment orthogonal radiographs were analyzed, and both pretreatment setup residual error and intrafraction-motion data were obtained. Population histograms of intrafraction motion were plotted for both types of balloons. Population planning target-volume (PTV) margins were calculated with the van Herk formula of 2.5{Sigma}+ 0.7{sigma} to account for setup residual errors and intrafraction motion errors. Results: Pretreatment and post-treatment radiographs indicated that the use of gas-release rectal balloons reduced prostate intrafraction motion along superior-inferior (SI) and anterior-posterior (AP) directions. Similar patient setup residual errors were exhibited for both types of balloons. Gas-release rectal balloons resulted in PTV margin reductions from 3.9 to 2.8 mm in the SI direction, 3.1 to 1.8 mm in the AP direction, and an increase from 1.9 to 2.1 mm in the left-right direction. Conclusions: Prostate intrafraction motion is an important uncertainty source in radiotherapy after image-guided patient setup with online corrections. Compared to non-gas-release rectal balloons, gas-release balloons can reduce prostate intrafraction motion in the SI and AP directions caused by gas buildup.

  17. Assessing the co-benefits of greenhouse gas reduction: health benefits of particulate matter related inspection and maintenance programs in Bangkok, Thailand.

    PubMed

    Li, Ying; Crawford-Brown, Douglas J

    2011-04-15

    Since the 1990s, the capital city of Thailand, Bangkok has been suffering from severe ambient particulate matter (PM) pollution mainly attributable to its wide use of diesel-fueled vehicles and motorcycles with poor emission performance. While the Thai government strives to reduce emissions from transportation through enforcing policy measures, the link between specific control policies and associated health impacts is inadequately studied. This link is especially important in exploring the co-benefits of greenhouse gas emissions reductions, which often brings reduction in other pollutants such as PM. This paper quantifies the health benefits potentially achieved by the new PM-related I/M programs targeting all diesel vehicles and motorcycles in the Bangkok Metropolitan Area (BMA). The benefits are estimated by using a framework that integrates policy scenario development, exposure assessment, exposure-response assessment and economic valuation. The results indicate that the total health damage due to the year 2000 PM emissions from vehicles in the BMA was equivalent to 2.4% of Thailand's GDP. Under the business-as-usual (BAU) scenario, total vehicular PM emissions in the BMA will increase considerably over time due to the rapid growth in vehicle population, even if the fleet average emission rates are projected to decrease over time as the result of participation of Thailand in post-Copenhagen climate change strategies. By 2015, the total health damage is estimated to increase by 2.5 times relative to the year 2000. However, control policies targeting PM emissions from automobiles, such as the PM-oriented I/M programs, could yield substantial health benefits relative to the BAU scenario, and serve as co-benefits of greenhouse gas control strategies. Despite uncertainty associated with the key assumptions used to estimate benefits, we find that with a high level confidence, the I/M programs will produce health benefits whose economic impacts considerably outweigh

  18. Development of natural gas injection technology for NO sub x reduction from municipal waste combustors

    SciTech Connect

    Abbasi, H.A.; Khinkis, M.J. ); Penterson, C.A.; Zone, F. ); Dunnette, R. ); Nakazato, K. ); Duggan, P.A.; Linz, D.G. )

    1991-01-01

    Natural gas injection (NGI) technology for reducing NO{sub x} emissions from municipal waste combustors (MWCs) is being developed. The approach involves the injection of natural gas, together with recirculated flue gases (for mixing), above the grate to provide reducing combustion conditions that promote the destruction of NO{sub x} precursors, as well as NO{sub x}. Extensive development testing was subsequently carried out in a 2.5 {times} 10{sup 6} Btu/h (0.7 MWth) pilot-scale MWC firing actual MSW. Both tests, using simulated combustion products and actual MSW, showed that 50% to 70% NO{sub x} reduction could be achieved. These results were used to define the key operating parameters. A full-scale system has been designed and retrofitted to a 100-ton/day Riley/Takuma mass burn system at the Olmsted County Waste-to-Energy facility. The system was designed to provide variation in the key parameters to not only optimize the process for the Olmsted unit, but also to acquire design data for MWCs of other sizes and designs. Extensive testing was conducted to December 1990 and January 1991 to evaluate the effectiveness of NGI. This paper concentrates on the METHANE de-NO{sub x} system retrofit and testing. The results show simultaneous reductions of 60% in NO{sub x}, 50% in CO, and 40% in excess air requirement with natural gas injection. 4 refs., 5 figs., 1 tab.

  19. Importance sampling variance reduction for the Fokker-Planck rarefied gas particle method

    NASA Astrophysics Data System (ADS)

    Collyer, B. S.; Connaughton, C.; Lockerby, D. A.

    2016-11-01

    The Fokker-Planck approximation to the Boltzmann equation, solved numerically by stochastic particle schemes, is used to provide estimates for rarefied gas flows. This paper presents a variance reduction technique for a stochastic particle method that is able to greatly reduce the uncertainty of the estimated flow fields when the characteristic speed of the flow is small in comparison to the thermal velocity of the gas. The method relies on importance sampling, requiring minimal changes to the basic stochastic particle scheme. We test the importance sampling scheme on a homogeneous relaxation, planar Couette flow and a lid-driven-cavity flow, and find that our method is able to greatly reduce the noise of estimated quantities. Significantly, we find that as the characteristic speed of the flow decreases, the variance of the noisy estimators becomes independent of the characteristic speed.

  20. Adjustment of the flue gas path in small combustion appliances with regard to particulate matter reduction

    NASA Astrophysics Data System (ADS)

    Sulovcová, Katarína; Jandačka, Jozef; Nosek, Radovan

    2014-08-01

    Concentration of solid particles in ambient atmosphere is increasing in many countries nowadays. Particulate matter pollution in higher concentration has harmful impact on human and animal health. Source of particulate matter are not only industry and traffic. Small heat sources with biomass combustion, especially during winter heating season, are also significant producer of particulate matter emission. There is a huge importance to decrease quantities of solid particles which are getting into the atmosphere in every region of their production in order to decrease environmental pollution and improve air quality. The ability of flue gas emission elimination can influence future using of biomass combustion. Therefore effective and affordable solutions are searching for. The paper deals with the reduction of particulate matter in small heat source with biomass combustion by modification of geometric parameters in flue gas path.

  1. From "farm to fork" strawberry system: current realities and potential innovative scenarios from life cycle assessment of non-renewable energy use and green house gas emissions.

    PubMed

    Girgenti, Vincenzo; Peano, Cristiana; Baudino, Claudio; Tecco, Nadia

    2014-03-01

    In this study, we analysed the environmental profile of the strawberry industry in Northern Italy. The analysis was conducted using two scenarios as reference systems: strawberry crops grown in unheated plastic tunnels using currently existing cultivation techniques, post-harvest management practices and consumption patterns (scenario 1) and the same strawberry cultivation chain in which some of the materials used were replaced with bio-based materials (scenario 2). In numerous studies, biodegradable polymers have been shown to be environmentally friendly, thus potentially reducing environmental impacts. These materials can be recycled into carbon dioxide and water through composting. Many materials, such as Mater-BI® and PLA®, are also derived from renewable resources. The methodology chosen for the environmental analysis was a life cycle assessment (LCA) based on a consequential approach developed to assess a product's overall environmental impact from the production system to its usage and disposal. In the field stage, a traditional mulching film (non-biodegradable) could be replaced with a biodegradable product. This change would result in waste production of 0 kg/ha for the bio-based product compared to 260 kg/ha of waste for polyethylene (PE). In the post-harvest stage, the issue addressed was the use and disposal of packaging materials. The innovative scenario evaluated herein pertains to the use of new packaging materials that increase the shelf life of strawberries, thereby decreasing product losses while increasing waste management efficiency at the level of a distribution platform and/or sales outlet. In the event of product deterioration or non-sale of the product, the packaging and its contents could be collected together as organic waste without any additional processes because the packaging is compostable according to EN13432. Scenario 2 would achieve reductions of 20% in the global warming potential and non-renewable energy impact categories.

  2. Alternative technologies for the reduction of greenhouse gas emissions from palm oil mills in Thailand.

    PubMed

    Kaewmai, Roihatai; H-Kittikun, Aran; Suksaroj, Chaisri; Musikavong, Charongpun

    2013-01-01

    Alternative methodologies for the reduction of greenhouse gas (GHG) emissions from crude palm oil (CPO) production by a wet extraction mill in Thailand were developed. The production of 1 t of CPO from mills with biogas capture (four mills) and without biogas capture (two mills) in 2010 produced GHG emissions of 935 kg carbon dioxide equivalent (CO2eq), on average. Wastewater treatment plants with and without biogas capture produced GHG emissions of 64 and 47% of total GHG emission, respectively. The rest of the emissions mostly originated from the acquisition of fresh fruit bunches. The establishment of a biogas recovery system must be the first step in the reduction of GHG emissions. It could reduce GHG emissions by 373 kgCO2eq/t of CPO. The main source of GHG emission of 163 kgCO2eq/t of CPO from the mills with biogas capture was the open pond used for cooling of wastewater before it enters the biogas recovery system. The reduction of GHG emissions could be accomplished by (i) using a wastewater-dispersed unit for cooling, (ii) using a covered pond, (iii) enhancing the performance of the biogas recovery system, and (iv) changing the stabilization pond to an aerated lagoon. By using options i-iv, reductions of GHG emissions of 216, 208, 92.2, and 87.6 kgCO2eq/t of CPO, respectively, can be achieved.

  3. Mechanisms of gas exchange response to lung volume reduction surgery in severe emphysema.

    PubMed

    Cremona, George; Barberà, Joan A; Barbara, Joan A; Melgosa, Teresa; Appendini, Lorenzo; Roca, Josep; Casadio, Caterina; Donner, Claudio F; Rodriguez-Roisin, Roberto; Wagner, Peter D

    2011-04-01

    Lung volume reduction surgery (LVRS) improves lung function, respiratory symptoms, and exercise tolerance in selected patients with chronic obstructive pulmonary disease, who have heterogeneous emphysema. However, the reported effects of LVRS on gas exchange are variable, even when lung function is improved. To clarify how LVRS affects gas exchange in chronic obstructive pulmonary disease, 23 patients were studied before LVRS, 14 of whom were again studied afterwards. We performed measurements of lung mechanics, pulmonary hemodynamics, and ventilation-perfusion (Va/Q) inequality using the multiple inert-gas elimination technique. LVRS improved arterial Po₂ (Pa(O₂)) by a mean of 6 Torr (P = 0.04), with no significant effect on arterial Pco₂ (Pa(CO₂)), but with great variability in both. Lung mechanical properties improved considerably more than did gas exchange. Post-LVRS Pa(O₂) depended mostly on its pre-LVRS value, whereas improvement in Pa(O(2)) was explained mostly by improved Va/Q inequality, with lesser contributions from both increased ventilation and higher mixed venous Po(2). However, no index of lung mechanical properties correlated with Pa(O₂). Conversely, post-LVRS Pa(CO₂) bore no relationship to its pre-LVRS value, whereas changes in Pa(CO₂) were tightly related (r² = 0.96) to variables, reflecting decrease in static lung hyperinflation (intrinsic positive end-expiratory pressure and residual volume/total lung capacity) and increase in airflow potential (tidal volume and maximal inspiratory pressure), but not to Va/Q distribution changes. Individual gas exchange responses to LVRS vary greatly, but can be explained by changes in combinations of determining variables that are different for oxygen and carbon dioxide.

  4. Estimates of solid waste disposal rates and reduction targets for landfill gas emissions

    NASA Astrophysics Data System (ADS)

    Powell, Jon T.; Townsend, Timothy G.; Zimmerman, Julie B.

    2016-02-01

    Landfill disposal of municipal solid waste represents one of the largest anthropogenic global methane emission sources, and recent policy approaches have targeted significant reductions of these emissions to combat climate change in the US (ref. ). The efficacy of active gas collection systems in the US was examined by analysing performance data, including fire occurrence, from more than 850 landfills. A generalized linear model showed that the operating status of a landfill--open and actively receiving waste or closed--was the most significant predictor of collection system performance. Gas collection systems at closed landfills were statistically significantly more efficient (p < 0.001) and on average 17 percentage points more efficient than those at open landfills, but open landfills were found to represent 91% of all landfill methane emissions. These results demonstrate the clear need to target open landfills to achieve significant near-term methane emission reductions. This observation is underscored by landfill disposal rates in the US significantly exceeding previously reported national estimates, with this study reporting 262 million tonnes in the year 2012 compared with 122 million tonnes in 2012 as estimated by the US Environmental Protection Agency.

  5. Greenhouse Emission Reductions and Natural Gas Vehicles: A Resource Guide on Technology Options and Project Development

    SciTech Connect

    Orestes Anastasia; NAncy Checklick; Vivianne Couts; Julie Doherty; Jette Findsen; Laura Gehlin; Josh Radoff

    2002-09-01

    Accurate and verifiable emission reductions are a function of the degree of transparency and stringency of the protocols employed in documenting project- or program-associated emissions reductions. The purpose of this guide is to provide a background for law and policy makers, urban planners, and project developers working with the many Greenhouse Gas (GHG) emission reduction programs throughout the world to quantify and/or evaluate the GHG impacts of Natural Gas Vehicle (NGVs). In order to evaluate the GHG benefits and/or penalties of NGV projects, it is necessary to first gain a fundamental understanding of the technology employed and the operating characteristics of these vehicles, especially with regard to the manner in which they compare to similar conventional gasoline or diesel vehicles. Therefore, the first two sections of this paper explain the basic technology and functionality of NGVs, but focus on evaluating the models that are currently on the market with their similar conventional counterparts, including characteristics such as cost, performance, efficiency, environmental attributes, and range. Since the increased use of NGVs, along with Alternative Fuel Vehicle (AFVs) in general, represents a public good with many social benefits at the local, national, and global levels, NGVs often receive significant attention in the form of legislative and programmatic support. Some states mandate the use of NGVs, while others provide financial incentives to promote their procurement and use. Furthermore, Federal legislation in the form of tax incentives or procurement requirements can have a significant impact on the NGV market. In order to implement effective legislation or programs, it is vital to have an understanding of the different programs and activities that already exist so that a new project focusing on GHG emission reduction can successfully interact with and build on the experience and lessons learned of those that preceded it. Finally, most programs

  6. Reduction in greenhouse gas emissions from sewage sludge aerobic compost in China.

    PubMed

    Liu, H-t; Zheng, H-x; Chen, T-b; Zheng, G-d; Gao, D

    2014-01-01

    Sewage sludge is an important contributor to greenhouse gas (GHG) emissions and the carbon budget of organic solid waste treatment and disposal. In this case study, total GHG emissions from an auto-control sludge compost system, including direct and indirect emissions and replaceable reduction due to sludge compost being reused as fertilizer, were quantified. The results indicated that no methane generation needed to be considered in the carbon debit because of the advantages of auto-control for monitoring and maintenance of appropriate conditions during the composting process. Indirect emissions were mainly from electricity and fossil fuel consumption, including sludge transportation and mechanical equipment use. Overall, the total carbon replaceable emission reduction owing to sludge being treated by composting rather than landfill, and reuse of its compost as fertilizer instead of chemical fertilizer, were calculated to be 0.6204 tCO2e t(-1) relative to baseline. Auto-control compost can facilitate obtaining certified emission reduction warrants, which are essential to accessing financial support with the authentication by the Clean Development Mechanism.

  7. Role of natural gas in meeting an electric sector emissions reduction strategy and effects on greenhouse gas emissions

    EPA Science Inventory

    With advances in natural gas extraction technologies, there is an increase in availability of domestic natural gas, and natural gas is gaining a larger share of use as a fuel in electricity production. At the power plant, natural gas is a cleaner burning fuel than coal, but unce...

  8. CFD methods for the reduction of reactive gas emission from a paper laminating machine.

    PubMed

    Horvath, Andras; Jordan, Christian; Forstner, Gerhard; Altacher, Peter; Harasek, Michael

    2007-06-18

    In cooperation with the world's second largest manufacturer of beverage cartons (SIG Combibloc) for liquid foodstuffs an innovative off-take for neutralisation of reactive gas in a paper laminating machine was constructed. A great challenge during engineering work was ensuring a high concentration of the reactive gas where needed and at the same time minimising work place impact in a machine basically without housing. Preliminary 2D-models of the machine geometry proved to be insufficient in describing all the governing flow phenomena. A simplified 3D-geometry containing all important parts of the complex machinery was necessary for accurate predictions. It was found that the driving force of air movement and transport of reactive gas (which acts as an adhesive agent) from the reaction zone in the interior of the laminating machine to the outside is a boundary flow caused by the rapid movement of carton material and rotating cylinders. A physically correct simulation result of the boundary flow is a premise for correct prediction of air flow in and around the machinery. Lacking experimental data (due to an inaccessible geometry) a worst case scenario was constructed by generating a grid and using turbulence models that maximised mass transport in the boundary layer region and thus emission of (tracer)gas from the machine. CFD simulations were done using the geometry preprocessor Gambit, and the finite volume solver Fluent. The results of the analysis of the emission paths from the machine were surprising and led to the construction of an effective off-take relatively far away from the emission source. The chosen position ensures low disturbance of highly sensitive flow patterns inside the machine and diffusive mixing, dilution and contamination of the surroundings. The effect of the new off-take is an immediate and significant rise in air quality in the vicinity of the laminating machine and ensures maximum allowed concentration in the plant area. The product

  9. Achieving Realistic Energy and Greenhouse Gas Emission Reductions in U.S. Cities

    NASA Astrophysics Data System (ADS)

    Blackhurst, Michael F.

    2011-12-01

    In recognizing that energy markets and greenhouse gas emissions are significantly influences by local factors, this research examines opportunities for achieving realistic energy greenhouse gas emissions from U.S. cities through provisions of more sustainable infrastructure. Greenhouse gas reduction opportunities are examined through the lens of a public program administrator charged with reducing emissions given realistic financial constraints and authority over emissions reductions and energy use. Opportunities are evaluated with respect to traditional public policy metrics, such as benefit-cost analysis, net benefit analysis, and cost-effectiveness. Section 2 summarizes current practices used to estimate greenhouse gas emissions from communities. I identify improved and alternative emissions inventory techniques such as disaggregating the sectors reported, reporting inventory uncertainty, and aligning inventories with local organizations that could facilitate emissions mitigation. The potential advantages and challenges of supplementing inventories with comparative benchmarks are also discussed. Finally, I highlight the need to integrate growth (population and economic) and business as usual implications (such as changes to electricity supply grids) into climate action planning. I demonstrate how these techniques could improve decision making when planning reductions, help communities set meaningful emission reduction targets, and facilitate CAP implementation and progress monitoring. Section 3 evaluates the costs and benefits of building energy efficiency are estimated as a means of reducing greenhouse gas emissions in Pittsburgh, PA and Austin, TX. Two policy objectives were evaluated: maximize GHG reductions given initial budget constraints or maximize social savings given target GHG reductions. This approach explicitly evaluates the trade-offs between three primary and often conflicting program design parameters: initial capital constraints, social savings

  10. Discrete velocity computations with stochastic variance reduction of the Boltzmann equation for gas mixtures

    SciTech Connect

    Clarke, Peter; Varghese, Philip; Goldstein, David

    2014-12-09

    We extend a variance reduced discrete velocity method developed at UT Austin [1, 2] to gas mixtures with large mass ratios and flows with trace species. The mixture is stored as a collection of independent velocity distribution functions, each with a unique grid in velocity space. Different collision types (A-A, A-B, B-B, etc.) are treated independently, and the variance reduction scheme is formulated with different equilibrium functions for each separate collision type. The individual treatment of species enables increased focus on species important to the physics of the flow, even if the important species are present in trace amounts. The method is verified through comparisons to Direct Simulation Monte Carlo computations and the computational workload per time step is investigated for the variance reduced method.

  11. Greenhouse gas and criteria emission benefits through reduction of vessel speed at sea.

    PubMed

    Khan, M Yusuf; Agrawal, Harshit; Ranganathan, Sindhuja; Welch, William A; Miller, J Wayne; Cocker, David R

    2012-11-20

    Reducing emissions from ocean-going vessels (OGVs) as they sail near populated areas is a widely recognized goal, and Vessel Speed Reduction (VSR) is one of several strategies that is being adopted by regulators and port authorities. The goal of this research was to measure the emission benefits associated with greenhouse gas and criteria pollutants by operating OGVs at reduced speed. Emissions were measured from one Panamax and one post-Panamax class container vessels as their vessel speed was reduced from cruise to 15 knots or below. VSR to 12 knots yielded carbon dioxide (CO(2)) and nitrogen oxides (NO(x)) emissions reductions (in kg/nautical mile (kg/nmi)) of approximately 61% and 56%, respectively, as compared to vessel cruise speed. The mass emission rate (kg/nmi) of PM(2.5) was reduced by 69% with VSR to 12 knots alone and by ~97% when coupled with the use of the marine gas oil (MGO) with 0.00065% sulfur content. Emissions data from vessels while operating at sea are scarce and measurements from this research demonstrated that tidal current is a significant parameter affecting emission factors (EFs) at lower engine loads. Emissions factors at ≤20% loads calculated by methodology adopted by regulatory agencies were found to underestimate PM(2.5) and NO(x) by 72% and 51%, respectively, when compared to EFs measured in this study. Total pollutant emitted (TPE) in the emission control area (ECA) was calculated, and emission benefits were estimated as the VSR zone increased from 24 to 200 nmi. TPE(CO2) and TPE(PM2.5) estimated for large container vessels showed benefits for CO(2) (2-26%) and PM(2.5) (4-57%) on reducing speeds from 15 to 12 knots, whereas TPE(CO2) and TPE(PM2.5) for small and medium container vessels were similar at 15 and 12 knots.

  12. Case study of selective catalytic reduction system start-up on digester gas fired combustion turbines

    SciTech Connect

    Conway, V.O.; Min, S.W.; Adams, G.M.

    1997-12-31

    In August 1989, the South Coast Air Quality Management District (SCAQMD) adopted Rule 1134 which imposed strict NO{sub x} emission limits on stationary, non-utility, combustion turbines. The rule was technology-forcing for the owners and operators of digester gas fired combustion turbines since it established a NO{sub x} emission limit of 9 parts per million by volume at 15 percent oxygen. The County Sanitation Districts of Los Angeles County (Districts), operators of three 6.5 MW digester gas fired turbines, elected to retrofit the turbines with selective catalytic reduction (SCR) systems to achieve compliance with the SCAQMD rule. After four years and costs in excess of four million dollars, the Districts continue to work on achieving system performance goals. This case study provides a brief history of the development of Rule 1134 and the motivation behind the strict NO{sub x} limits. The Districts` rationale in choosing SCR systems as a means of attaining compliance is presented along with a discussion of the physical site constraints which resulted in a less than optimum retrofit installation of the SCR systems. SCR system performance problems are examined including what was suspected to be poisoning of the catalyst by potassium in the turbine exhaust gas. The major actions undertaken by the Districts, its contractor and subcontractors to bring the turbines into compliance are also presented including optimizing exhaust flow distribution through the catalyst reactor, optimizing the ammonia mixing in the exhaust duct, optimizing water injection rates, installing intake combustion air evaporative cooling systems, reactivating the catalyst with resistant coatings, and undertaking structural retrofits to prevent distortion of the reactor house caused by thermal expansion. The case study concludes with a brief summary of the SCR systems` final physical configuration and performance and an update on the pending regulation changes.

  13. Impacts of Vehicle Weight Reduction via Material Substitution on Life-Cycle Greenhouse Gas Emissions.

    PubMed

    Kelly, Jarod C; Sullivan, John L; Burnham, Andrew; Elgowainy, Amgad

    2015-10-20

    This study examines the vehicle-cycle and vehicle total life-cycle impacts of substituting lightweight materials into vehicles. We determine part-based greenhouse gas (GHG) emission ratios by collecting material substitution data and evaluating that alongside known mass-based GHG ratios (using and updating Argonne National Laboratory's GREET model) associated with material pair substitutions. Several vehicle parts are lightweighted via material substitution, using substitution ratios from a U.S. Department of Energy report, to determine GHG emissions. We then examine fuel-cycle GHG reductions from lightweighting. The fuel reduction value methodology is applied using FRV estimates of 0.15-0.25, and 0.25-0.5 L/(100km·100 kg), with and without powertrain adjustments, respectively. GHG breakeven values are derived for both driving distance and material substitution ratio. While material substitution can reduce vehicle weight, it often increases vehicle-cycle GHGs. It is likely that replacing steel (the dominant vehicle material) with wrought aluminum, carbon fiber reinforced plastic (CRFP), or magnesium will increase vehicle-cycle GHGs. However, lifetime fuel economy benefits often outweigh the vehicle-cycle, resulting in a net total life-cycle GHG benefit. This is the case for steel replaced by wrought aluminum in all assumed cases, and for CFRP and magnesium except for high substitution ratio and low FRV.

  14. Reduction of the Powerful Greenhouse Gas N2O in the South-Eastern Indian Ocean

    PubMed Central

    Raes, Eric J.; Bodrossy, Levente; Van de Kamp, Jodie; Holmes, Bronwyn; Hardman-Mountford, Nick; Thompson, Peter A.; McInnes, Allison S.; Waite, Anya M.

    2016-01-01

    Nitrous oxide (N2O) is a powerful greenhouse gas and a key catalyst of stratospheric ozone depletion. Yet, little data exist about the sink and source terms of the production and reduction of N2O outside the well-known oxygen minimum zones (OMZ). Here we show the presence of functional marker genes for the reduction of N2O in the last step of the denitrification process (nitrous oxide reductase genes; nosZ) in oxygenated surface waters (180–250 O2 μmol.kg-1) in the south-eastern Indian Ocean. Overall copy numbers indicated that nosZ genes represented a significant proportion of the microbial community, which is unexpected in these oxygenated waters. Our data show strong temperature sensitivity for nosZ genes and reaction rates along a vast latitudinal gradient (32°S-12°S). These data suggest a large N2O sink in the warmer Tropical waters of the south-eastern Indian Ocean. Clone sequencing from PCR products revealed that most denitrification genes belonged to Rhodobacteraceae. Our work highlights the need to investigate the feedback and tight linkages between nitrification and denitrification (both sources of N2O, but the latter also a source of bioavailable N losses) in the understudied yet strategic Indian Ocean and other oligotrophic systems. PMID:26800249

  15. Impacts of Vehicle Weight Reduction via Material Substitution on Life-Cycle Greenhouse Gas Emissions

    SciTech Connect

    Kelly, Jarod C.; Sullivan, John L.; Burnham, Andrew; Elgowainy, Amgad

    2015-10-20

    This study examines the vehicle-cycle impacts associated with substituting lightweight materials for those currently found in light-duty passenger vehicles. We determine part-based energy use and greenhouse gas (GHG) emission ratios by collecting material substitution data from both the literature and automotive experts and evaluating that alongside known mass-based energy use and GHG emission ratios associated with material pair substitutions. Several vehicle parts, along with full vehicle systems, are examined for lightweighting via material substitution to observe the associated impact on GHG emissions. Results are contextualized by additionally examining fuel-cycle GHG reductions associated with mass reductions relative to the baseline vehicle during the use phase and also determining material pair breakeven driving distances for GHG emissions. The findings show that, while material substitution is useful in reducing vehicle weight, it often increases vehicle-cycle GHGs depending upon the material substitution pair. However, for a vehicle’s total life cycle, fuel economy benefits are greater than the increased burdens associated with the vehicle manufacturing cycle, resulting in a net total life-cycle GHG benefit. The vehicle cycle will become increasingly important in total vehicle life-cycle GHGs, since fuel-cycle GHGs will be gradually reduced as automakers ramp up vehicle efficiency to meet fuel economy standards.

  16. Reduction of the Powerful Greenhouse Gas N2O in the South-Eastern Indian Ocean.

    PubMed

    Raes, Eric J; Bodrossy, Levente; Van de Kamp, Jodie; Holmes, Bronwyn; Hardman-Mountford, Nick; Thompson, Peter A; McInnes, Allison S; Waite, Anya M

    2016-01-01

    Nitrous oxide (N2O) is a powerful greenhouse gas and a key catalyst of stratospheric ozone depletion. Yet, little data exist about the sink and source terms of the production and reduction of N2O outside the well-known oxygen minimum zones (OMZ). Here we show the presence of functional marker genes for the reduction of N2O in the last step of the denitrification process (nitrous oxide reductase genes; nosZ) in oxygenated surface waters (180-250 O2 μmol.kg(-1)) in the south-eastern Indian Ocean. Overall copy numbers indicated that nosZ genes represented a significant proportion of the microbial community, which is unexpected in these oxygenated waters. Our data show strong temperature sensitivity for nosZ genes and reaction rates along a vast latitudinal gradient (32°S-12°S). These data suggest a large N2O sink in the warmer Tropical waters of the south-eastern Indian Ocean. Clone sequencing from PCR products revealed that most denitrification genes belonged to Rhodobacteraceae. Our work highlights the need to investigate the feedback and tight linkages between nitrification and denitrification (both sources of N2O, but the latter also a source of bioavailable N losses) in the understudied yet strategic Indian Ocean and other oligotrophic systems.

  17. Electrification of the transportation sector offers limited country-wide greenhouse gas reductions

    NASA Astrophysics Data System (ADS)

    Meinrenken, Christoph J.; Lackner, Klaus S.

    2014-03-01

    Compared with conventional propulsion, plugin and hybrid vehicles may offer reductions in greenhouse gas (GHG) emissions, regional air/noise pollution, petroleum dependence, and ownership cost. Comparing only plugins and hybrids amongst themselves, and focusing on GHG, relative merits of different options have been shown to be more nuanced, depending on grid-carbon-intensity, range and thus battery manufacturing and weight, and trip patterns. We present a life-cycle framework to compare GHG emissions for three drivetrains (plugin-electricity-only, gasoline-only-hybrid, and plugin-hybrid) across driving ranges and grid-carbon-intensities, for passenger cars, vans, buses, or trucks (well-to-wheel plus storage manufacturing). Parameter and model uncertainties are quantified via sensitivity analyses. We find that owing to the interplay of range, GHG/km, and portions of country-wide kms accessible to electrification, GHG reductions achievable from plugins (whether electricity-only or hybrids) are limited even when assuming low-carbon future grids. Furthermore, for policy makers considering GHG from electricity and transportation sectors combined, plugin technology may in fact increase GHG compared to gasoline-only-hybrids, regardless of grid-carbon-intensity.

  18. Current advances of integrated processes combining chemical absorption and biological reduction for NO x removal from flue gas.

    PubMed

    Zhang, Shihan; Chen, Han; Xia, Yinfeng; Liu, Nan; Lu, Bi-Hong; Li, Wei

    2014-10-01

    Anthropogenic nitrogen oxides (NO x ) emitted from the fossil-fuel-fired power plants cause adverse environmental issues such as acid rain, urban ozone smoke, and photochemical smog. A novel chemical absorption-biological reduction (CABR) integrated process under development is regarded as a promising alternative to the conventional selective catalytic reduction processes for NO x removal from the flue gas because it is economic and environmentally friendly. CABR process employs ferrous ethylenediaminetetraacetate [Fe(II)EDTA] as a solvent to absorb the NO x following microbial denitrification of NO x to harmless nitrogen gas. Meanwhile, the absorbent Fe(II)EDTA is biologically regenerated to sustain the adequate NO x removal. Compared with conventional denitrification process, CABR not only enhances the mass transfer of NO from gas to liquid phase but also minimize the impact of oxygen on the microorganisms. This review provides the current advances of the development of the CABR process for NO x removal from the flue gas.

  19. Contribution of cooperative sector recycling to greenhouse gas emissions reduction: A case study of Ribeirão Pires, Brazil

    SciTech Connect

    King, Megan F.; Gutberlet, Jutta

    2013-12-15

    Highlights: • Cooperative recycling achieves environmental, economic and social objectives. • We calculate GHG emissions reduction for a recycling cooperative in São Paulo, Brazil. • The cooperative merits consideration as a Clean Development Mechanism (CDM) project. • A CDM project would enhance the achievements of the recycling cooperative. • National and local waste management policies support the recycling cooperative. - Abstract: Solid waste, including municipal waste and its management, is a major challenge for most cities and among the key contributors to climate change. Greenhouse gas emissions can be reduced through recovery and recycling of resources from the municipal solid waste stream. In São Paulo, Brazil, recycling cooperatives play a crucial role in providing recycling services including collection, separation, cleaning, stocking, and sale of recyclable resources. The present research attempts to measure the greenhouse gas emission reductions achieved by the recycling cooperative Cooperpires, as well as highlight its socioeconomic benefits. Methods include participant observation, structured interviews, questionnaire application, and greenhouse gas accounting of recycling using a Clean Development Mechanism methodology. The results show that recycling cooperatives can achieve important energy savings and reductions in greenhouse gas emissions, and suggest there is an opportunity for Cooperpires and other similar recycling groups to participate in the carbon credit market. Based on these findings, the authors created a simple greenhouse gas accounting calculator for recyclers to estimate their emissions reductions.

  20. Hot gas in the cold dark matter scenario: X-ray clusters from a high-resolution numerical simulation

    NASA Technical Reports Server (NTRS)

    Kang, Hyesung; Cen, Renyue; Ostriker, Jeremiah P.; Ryu, Dongsu

    1994-01-01

    A new, three-dimensional, shock-capturing hydrodynamic code is utilized to determine the distribution of hot gas in a standard cold dark matter (CDM) model of the universe. Periodic boundary conditions are assumed: a box with size 85 h(exp -1) Mpc having cell size 0.31 h(exp -1) Mpc is followed in a simulation with 270(exp 3) = 10(exp 7.3) cells. Adopting standard parameters determined from COBE and light-element nucleosynthesis, sigma(sub 8) = 1.05, omega(sub b) = 0.06, and assuming h = 0.5, we find the X-ray-emitting clusters and compute the luminosity function at several wavelengths, the temperature distribution, and estimated sizes, as well as the evolution of these quantities with redshift. We find that most of the total X-ray emissivity in our box originates in a relatively small number of identifiable clusters which occupy approximately 10(exp -3) of the box volume. This standard CDM model, normalized to COBE, produces approximately 5 times too much emission from clusters having L(sub x) is greater than 10(exp 43) ergs/s, a not-unexpected result. If all other parameters were unchanged, we would expect adequate agreement for sigma(sub 8) = 0.6. This provides a new and independent argument for lower small-scale power than standard CDM at the 8 h(exp -1) Mpc scale. The background radiation field at 1 keV due to clusters in this model is approximately one-third of the observed background, which, after correction for numerical effects, again indicates approximately 5 times too much emission and the appropriateness of sigma(sub 8) = 0.6. If we have used the observed ratio of gas to total mass in clusters, rather than basing the mean density on light-element nucleosynthesis, then the computed luminosity of each cluster would have increased still further, by a factor of approximately 10. The number density of clusters increases to z approximately 1, but the luminosity per typical cluster decreases, with the result that evolution in the number density of bright

  1. Hot gas in the cold dark matter scenario: X-ray clusters from a high-resolution numerical simulation

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung; Cen, Renyue; Ostriker, Jeremiah P.; Ryu, Dongsu

    1994-06-01

    A new, three-dimensional, shock-capturing hydrodynamic code is utilized to determine the distribution of hot gas in a standard cold dark matter (CDM) model of the universe. Periodic boundary conditions are assumed: a box with size 85 h-1 Mpc having cell size 0.31 h-1 Mpc is followed in a simulation with 2703 = 107.3 cells. Adopting standard parameters determined from COBE and light-element nucleosynthesis, sigma8 = 1.05, omegab = 0.06, and assuming h = 0.5, we find the X-ray-emitting clusters and compute the luminosity function at several wavelengths, the temperature distribution, and estimated sizes, as well as the evolution of these quantities with redshift. We find that most of the total X-ray emissivity in our box originates in a relatively small number of identifiable clusters which occupy approximately 10-3 of the box volume. This standard CDM model, normalized to COBE, produces approximately 5 times too much emission from clusters having Lx is greater than 1043 ergs/s, a not-unexpected result. If all other parameters were unchanged, we would expect adequate agreement for sigma8 = 0.6. This provides a new and independent argument for lower small-scale power than standard CDM at the 8 h-1 Mpc scale. The background radiation field at 1 keV due to clusters in this model is approximately one-third of the observed background, which, after correction for numerical effects, again indicates approximately 5 times too much emission and the appropriateness of sigma8 = 0.6. If we have used the observed ratio of gas to total mass in clusters, rather than basing the mean density on light-element nucleosynthesis, then the computed luminosity of each cluster would have increased still further, by a factor of approximately 10. The number density of clusters increases to z approximately 1, but the luminosity per typical cluster decreases, with the result that evolution in the number density of bright clusters is moderate in this redshift range, showing a broad peak near z = 0

  2. Health And Economic Impact Of Greenhouse Gas Emissions Reduction In Indonesia: SO2

    NASA Astrophysics Data System (ADS)

    Susandi, A.

    2004-12-01

    The objective of this study is to assess Indonesia's air quality. This comprised an assessment of Indonesia's air pollution levels and their impact on the development of health and the economics. Estimates are given of concentrations of one of the major pollutants: sulfur dioxide (SO2). Emissions are estimated for Indonesian region, based on energy consumption, derived from the MERGE simulation model. The air pollution levels projection for the year 2000 to the year 2100 are based on the IPCC scenarios, extended with some mitigation scenarios for the energy sector. If the Organisation for Economic Co-operation and Development (OECD) countries reduce their emissions, Indonesian oil consumption increases, and the emissions of SO2 are higher than in the baseline scenario. Health problems increase substantially, peaking to the middle of century in the A1B and B1 scenarios, and rising to the end of century in the A2 and B2 scenarios, while the health problem costs will be the highest during the middle of century in the A1B and B1 scenarios and toward the end of century in the A2 and B2 scenarios. With international trade in emission permits, Indonesia would be higher than in the baseline scenario, since more and more oil and coal using in domestic sources of energy, followed by higher of health problem cases and higher of health problem costs. The total cases of health problem are higher 18.5% than in the baseline scenario. If all countries reduce their emission, including Indonesia, the total concentrations of SO2 are lower than previous scenarios. The cases of health problem associated with SO2 are lower than in the baseline scenario and follow by the lower of the health problem costs. The costs of health problem associated with SO2 are to 35% lower than in the baseline scenario during the simulation period.

  3. MELTER OFF-GAS FLAMMABILITY ASSESSMENT FOR DWPF ALTERNATE REDUCTANT FLOWSHEET OPTIONS

    SciTech Connect

    Choi, A.

    2011-07-08

    Glycolic acid and sugar are being considered as potential candidates to substitute for much of the formic acid currently being added to the Defense Waste Processing Facility (DWPF) melter feed as a reductant. A series of small-scale melter tests were conducted at the Vitreous State Laboratory (VSL) in January 2011 to collect necessary data for the assessment of the impact of these alternate reductants on the melter off-gas flammability. The DM10 melter with a 0.021 m{sup 2} melt surface area was run with three different feeds which were prepared at SRNL based on; (1) the baseline formic/nitric acid flowsheet, (2) glycolic/formic/nitric acid flowsheet, and (3) sugar/formic/nitric acid flowsheet - these feeds will be called the baseline, glycolic, and sugar flowsheet feeds, respectively, hereafter. The actual addition of sugar to the sugar flowsheet feed was made at VSL before it was fed to the melter. For each feed, the DM10 was run under both bubbled (with argon) and non-bubbled conditions at varying melter vapor space temperatures. The goal was to lower its vapor space temperature from nominal 500 C to less than 300 C at 50 C increments and maintain steady state at each temperature at least for one hour, preferentially for two hours, while collecting off-gas data including CO, CO{sub 2}, and H{sub 2} concentrations. Just a few hours into the first test with the baseline feed, it was discovered that the DM10 vapor space temperature would not readily fall below 350 C simply by ramping up the feed rate as the test plan called for. To overcome this, ambient air was introduced directly into the vapor space through a dilution air damper in addition to the natural air inleakage occurring at the operating melter pressure of -1 inch H{sub 2}O. A detailed description of the DM10 run along with all the data taken is given in the report issued by VSL. The SRNL personnel have analyzed the DM10 data and identified 25 steady state periods lasting from 32 to 92 minutes for all

  4. RE-ENTRAINMENT AND DISPERSION OF EXHAUSTS FROM INDOOR RADON REDUCTION SYSTEMS: ANALYSIS OF TRACER GAS DATA

    EPA Science Inventory

    Tracer gas studies were conducted around four model houses in a wind tunnel, and around one house in the field, to quantify re-entrainment and dispersion of exhaust gases released from residential indoor radon reduction systems. Re-entrainment tests in the field suggest that acti...

  5. Contribution of cooperative sector recycling to greenhouse gas emissions reduction: a case study of Ribeirão Pires, Brazil.

    PubMed

    King, Megan F; Gutberlet, Jutta

    2013-12-01

    Solid waste, including municipal waste and its management, is a major challenge for most cities and among the key contributors to climate change. Greenhouse gas emissions can be reduced through recovery and recycling of resources from the municipal solid waste stream. In São Paulo, Brazil, recycling cooperatives play a crucial role in providing recycling services including collection, separation, cleaning, stocking, and sale of recyclable resources. The present research attempts to measure the greenhouse gas emission reductions achieved by the recycling cooperative Cooperpires, as well as highlight its socioeconomic benefits. Methods include participant observation, structured interviews, questionnaire application, and greenhouse gas accounting of recycling using a Clean Development Mechanism methodology. The results show that recycling cooperatives can achieve important energy savings and reductions in greenhouse gas emissions, and suggest there is an opportunity for Cooperpires and other similar recycling groups to participate in the carbon credit market. Based on these findings, the authors created a simple greenhouse gas accounting calculator for recyclers to estimate their emissions reductions.

  6. Save water to save carbon and money: developing abatement costs for expanded greenhouse gas reduction portfolios.

    PubMed

    Stokes, Jennifer R; Hendrickson, Thomas P; Horvath, Arpad

    2014-12-02

    The water-energy nexus is of growing interest for researchers and policy makers because the two critical resources are interdependent. Their provision and consumption contribute to climate change through the release of greenhouse gases (GHGs). This research considers the potential for conserving both energy and water resources by measuring the life-cycle economic efficiency of greenhouse gas reductions through the water loss control technologies of pressure management and leak management. These costs are compared to other GHG abatement technologies: lighting, building insulation, electricity generation, and passenger transportation. Each cost is calculated using a bottom-up approach where regional and temporal variations for three different California water utilities are applied to all alternatives. The costs and abatement potential for each technology are displayed on an environmental abatement cost curve. The results reveal that water loss control can reduce GHGs at lower cost than other technologies and well below California's expected carbon trading price floor. One utility with an energy-intensive water supply could abate 135,000 Mg of GHGs between 2014 and 2035 and save--rather than spend--more than $130/Mg using the water loss control strategies evaluated. Water loss control technologies therefore should be considered in GHG abatement portfolios for utilities and policy makers.

  7. Economic assessment and energy model scenarios of municipal solid waste incineration and gas turbine hybrid dual-fueled cycles in Thailand.

    PubMed

    Udomsri, Seksan; Martin, Andrew R; Fransson, Torsten H

    2010-07-01

    Finding environmentally benign methods related to sound municipal solid waste (MSW) management is of highest priority in Southeast Asia. It is very important to study new approaches which can reduce waste generation and simultaneously enhance energy recovery. One concrete example of particular significance is the concept of hybrid dual-fuel power plants featuring MSW and another high-quality fuel like natural gas. The hybrid dual-fuel cycles provide significantly higher electrical efficiencies than a composite of separate single-fuel power plant (standalone gas turbine combined cycle and MSW incineration). Although hybrid versions are of great importance for energy conversion from MSW, an economic assessment of these systems must be addressed for a realistic appraisal of these technologies. This paper aims to further examine an economic assessment and energy model analysis of different conversion technologies. Energy models are developed to further refine the expected potential of MSW incineration with regards to energy recovery and environmental issues. Results show that MSW incineration can play role for greenhouse gas reduction, energy recovery and waste management. In Bangkok, the electric power production via conventional incineration and hybrid power plants can cover 2.5% and 8% of total electricity consumption, respectively. The hybrid power plants have a relative short payback period (5 years) and can further reduce the CO(2) levels by 3% in comparison with current thermal power plants.

  8. Economic assessment and energy model scenarios of municipal solid waste incineration and gas turbine hybrid dual-fueled cycles in Thailand

    SciTech Connect

    Udomsri, Seksan; Martin, Andrew R.; Fransson, Torsten H.

    2010-07-15

    Finding environmentally benign methods related to sound municipal solid waste (MSW) management is of highest priority in Southeast Asia. It is very important to study new approaches which can reduce waste generation and simultaneously enhance energy recovery. One concrete example of particular significance is the concept of hybrid dual-fuel power plants featuring MSW and another high-quality fuel like natural gas. The hybrid dual-fuel cycles provide significantly higher electrical efficiencies than a composite of separate single-fuel power plant (standalone gas turbine combined cycle and MSW incineration). Although hybrid versions are of great importance for energy conversion from MSW, an economic assessment of these systems must be addressed for a realistic appraisal of these technologies. This paper aims to further examine an economic assessment and energy model analysis of different conversion technologies. Energy models are developed to further refine the expected potential of MSW incineration with regards to energy recovery and environmental issues. Results show that MSW incineration can play role for greenhouse gas reduction, energy recovery and waste management. In Bangkok, the electric power production via conventional incineration and hybrid power plants can cover 2.5% and 8% of total electricity consumption, respectively. The hybrid power plants have a relative short payback period (5 years) and can further reduce the CO{sub 2} levels by 3% in comparison with current thermal power plants.

  9. Calculation of energy recovery and greenhouse gas emission reduction from palm oil mill effluent treatment by an anaerobic granular-sludge process.

    PubMed

    Show, K Y; Ng, C A; Faiza, A R; Wong, L P; Wong, L Y

    2011-01-01

    Conventional aerobic and low-rate anaerobic processes such as pond and open-tank systems have been widely used in wastewater treatment. In order to improve treatment efficacy and to avoid greenhouse gas emissions, conventional treatment can be upgraded to a high performance anaerobic granular-sludge system. The anaerobic granular-sludge systems are designed to capture the biogas produced, rendering a potential for claims of carbon credits under the Kyoto Protocol for reducing emissions of greenhouse gases. Certified Emission Reductions (CERs) would be issued, which can be exchanged between businesses or bought and sold in international markets at the prevailing market prices. As the advanced anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they render more carbon credits than other conventional anaerobic systems. In addition to efficient waste degradation, the carbon credits can be used to generate revenue and to finance the project. This paper presents a scenario on emission avoidance based on a methane recovery and utilization project. An example analysis on emission reduction and an overview of the global emission market are also outlined.

  10. NOx Reduction with Natural Gas for Lean Large-Bore Engine Applications Using Lean NOx Trap Aftertreatment

    SciTech Connect

    Parks, JE

    2005-02-11

    Large-bore natural gas engines are used for distributed energy and gas compression since natural gas fuel offers a convenient and reliable fuel source via the natural gas pipeline and distribution infrastructure. Lean engines enable better fuel efficiency and lower operating costs; however, NOx emissions from lean engines are difficult to control. Technologies that reduce NOx in lean exhaust are desired to enable broader use of efficient lean engines. Lean NOx trap catalysts have demonstrated greater than 90% NOx reduction in lean exhaust from engines operating with gasoline, diesel, and natural gas fuels. In addition to the clean nature of the technology, lean NOx traps reduce NOx with the fuel source of the engine thereby eliminating the requirement for storage and handling of secondary fuels or reducing agents. A study of lean NOx trap catalysts for lean natural gas engines is presented here. Testing was performed on a Cummins C8.3G (CG-280) engine on a motor dynamometer. Lean NOx trap catalysts were tested for NOx reduction performance under various engine operating conditions, and the utilization of natural gas as the reductant fuel source was characterized. Engine test results show that temperature greatly affects the catalytic processes involved, specifically methane oxidation and NOx storage on the lean NOx trap. Additional studies on a bench flow reactor demonstrate the effect of precious metal loading (a primary cost factor) on lean NOx trap performance at different temperatures. Results and issues related to the potential of the lean NOx trap technology for large-bore engine applications will be discussed.

  11. Reductions in greenhouse gas (GHG) generation and energy consumption in wastewater treatment plants.

    PubMed

    Yerushalmi, L; Ashrafi, O; Haghighat, F

    2013-01-01

    Greenhouse gas (GHG) emission and energy consumption by on-site and off-site sources were estimated in two different wastewater treatment plants that used physical-chemical or biological processes for the removal of contaminants, and an anaerobic digester for sludge treatment. Physical-chemical treatment processes were used in the treatment plant of a locomotive repair factory that processed wastewater at 842 kg chemical oxygen demand per day. Approximately 80% of the total GHG emission was related to fossil fuel consumption for energy production. The emission of GHG was reduced by 14.5% with the recovery of biogas that was generated in the anaerobic digester and its further use as an energy source, replacing fossil fuels. The examined biological treatment system used three alternative process designs for the treatment of effluents from pulp and paper mills that processed wastewater at 2,000 kg biochemical oxygen demand per day. The three designs used aerobic, anaerobic, or hybrid aerobic/anaerobic biological processes for the removal of carbonaceous contaminants, and nitrification/denitrification processes for nitrogen removal. Without the recovery and use of biogas, the aerobic, anaerobic, and hybrid treatment systems generated 3,346, 6,554 and 7,056 kg CO(2)-equivalent/day, respectively, while the generated GHG was reduced to 3,152, 6,051, and 6,541 kg CO(2)-equivalent/day with biogas recovery. The recovery and use of biogas was shown to satisfy and exceed the energy needs of the three examined treatment plants. The reduction of operating temperature of the anaerobic digester and anaerobic reactor by 10°C reduced energy demands of the treatment plants by 35.1, 70.6 and 62.9% in the three examined treatment systems, respectively.

  12. Anaerobic oxidation of methane associated with sulfate reduction in a natural freshwater gas source

    PubMed Central

    Timmers, Peer HA; Suarez-Zuluaga, Diego A; van Rossem, Minke; Diender, Martijn; Stams, Alfons JM; Plugge, Caroline M

    2016-01-01

    The occurrence of anaerobic oxidation of methane (AOM) and trace methane oxidation (TMO) was investigated in a freshwater natural gas source. Sediment samples were taken and analyzed for potential electron acceptors coupled to AOM. Long-term incubations with 13C-labeled CH4 (13CH4) and different electron acceptors showed that both AOM and TMO occurred. In most conditions, 13C-labeled CO2 (13CO2) simultaneously increased with methane formation, which is typical for TMO. In the presence of nitrate, neither methane formation nor methane oxidation occurred. Net AOM was measured only with sulfate as electron acceptor. Here, sulfide production occurred simultaneously with 13CO2 production and no methanogenesis occurred, excluding TMO as a possible source for 13CO2 production from 13CH4. Archaeal 16S rRNA gene analysis showed the highest presence of ANME-2a/b (ANaerobic MEthane oxidizing archaea) and AAA (AOM Associated Archaea) sequences in the incubations with methane and sulfate as compared with only methane addition. Higher abundance of ANME-2a/b in incubations with methane and sulfate as compared with only sulfate addition was shown by qPCR analysis. Bacterial 16S rRNA gene analysis showed the presence of sulfate-reducing bacteria belonging to SEEP-SRB1. This is the first report that explicitly shows that AOM is associated with sulfate reduction in an enrichment culture of ANME-2a/b and AAA methanotrophs and SEEP-SRB1 sulfate reducers from a low-saline environment. PMID:26636551

  13. Implications of the recent reductions in natural gas prices for emissions of CO2 from the US power sector.

    PubMed

    Lu, Xi; Salovaara, Jackson; McElroy, Michael B

    2012-03-06

    CO(2) emissions from the US power sector decreased by 8.76% in 2009 relative to 2008 contributing to a decrease over this period of 6.59% in overall US emissions of greenhouse gases. An econometric model, tuned to data reported for regional generation of US electricity, is used to diagnose factors responsible for the 2009 decrease. More than half of the reduction is attributed to a shift from generation of power using coal to gas driven by a recent decrease in gas prices in response to the increase in production from shale. An important result of the model is that, when the cost differential for generation using gas rather than coal falls below 2-3 cents/kWh, less efficient coal fired plants are displaced by more efficient natural gas combined cycle (NGCC) generation alternatives. Costs for generation using NGCC decreased by close to 4 cents/kWh in 2009 relative to 2008 ensuring that generation of electricity using gas was competitive with coal in 2009 in contrast to the situation in 2008 when gas prices were much higher. A modest price on carbon could contribute to additional switching from coal to gas with further savings in CO(2) emissions.

  14. Near-Roadway Air Pollution and Coronary Heart Disease: Burden of Disease and Potential Impact of a Greenhouse Gas Reduction Strategy in Southern California

    PubMed Central

    Ghosh, Rakesh; Lurmann, Frederick; Perez, Laura; Penfold, Bryan; Brandt, Sylvia; Wilson, John; Milet, Meredith; Künzli, Nino; McConnell, Rob

    2015-01-01

    Background Several studies have estimated the burden of coronary heart disease (CHD) mortality from ambient regional particulate matter ≤ 2.5 μm (PM2.5). The burden of near-roadway air pollution (NRAP) generally has not been examined, despite evidence of a causal link with CHD. Objective We investigated the CHD burden from NRAP and compared it with the PM2.5 burden in the California South Coast Air Basin for 2008 and under a compact urban growth greenhouse gas reduction scenario for 2035. Methods We estimated the population attributable fraction and number of CHD events attributable to residential traffic density, proximity to a major road, elemental carbon (EC), and PM2.5 compared with the expected disease burden if the population were exposed to background levels of air pollution. Results In 2008, an estimated 1,300 CHD deaths (6.8% of the total) were attributable to traffic density, 430 deaths (2.4%) to residential proximity to a major road, and 690 (3.7%) to EC. There were 1,900 deaths (10.4%) attributable to PM2.5. Although reduced exposures in 2035 should result in smaller fractions of CHD attributable to traffic density, EC, and PM2.5, the numbers of estimated deaths attributable to each of these exposures are anticipated to increase to 2,500, 900, and 2,900, respectively, due to population aging. A similar pattern of increasing NRAP-attributable CHD hospitalizations was estimated to occur between 2008 and 2035. Conclusion These results suggest that a large burden of preventable CHD mortality is attributable to NRAP and is likely to increase even with decreasing exposure by 2035 due to vulnerability of an aging population. Greenhouse gas reduction strategies developed to mitigate climate change offer unexploited opportunities for air pollution health co-benefits. Citation Ghosh R, Lurmann F, Perez L, Penfold B, Brandt S, Wilson J, Milet M, Künzli N, McConnell R. 2016. Near-roadway air pollution and coronary heart disease: burden of disease and potential

  15. The Coanda effect in gas-dynamic noise control. [pressure reduction by silencers

    NASA Technical Reports Server (NTRS)

    Vasilescu, G.

    1974-01-01

    The principle types of silencers are discussed for gas dynamic noise of free steam and gas expansions, as well as the results of research in gas dynamics of jets and applied acoustics. Gas dynamic noise attenuation by means of the Coanda effect is due to fluid decompression in a Coanda ejector of the external type, where a structural change takes place in the acoustic frequency spectrum and in its direction, as well as a substantial decrease in the fluid's velocity, temperature and concentration. This process is continued in the second phase with absorption of the acoustic waves by means of an active structure.

  16. Effects of Lung Volume Reduction Surgery on Gas Exchange and Breathing Pattern During Maximum Exercise

    PubMed Central

    Criner, Gerard J.; Belt, Patricia; Sternberg, Alice L.; Mosenifar, Zab; Make, Barry J.; Utz, James P.; Sciurba, Frank

    2009-01-01

    Background: The National Emphysema Treatment Trial studied lung volume reduction surgery (LVRS) for its effects on gas exchange, breathing pattern, and dyspnea during exercise in severe emphysema. Methods: Exercise testing was performed at baseline, and 6, 12, and 24 months. Minute ventilation (V̇e), tidal volume (Vt), carbon dioxide output (V̇co2), dyspnea rating, and workload were recorded at rest, 3 min of unloaded pedaling, and maximum exercise. Pao2, Paco2, pH, fraction of expired carbon dioxide, and bicarbonate were also collected in some subjects at these time points and each minute of testing. There were 1,218 patients enrolled in the study (mean [± SD] age, 66.6 ± 6.1 years; mean, 61%; mean FEV1, 0.77 ± 0.24 L), with 238 patients participating in this substudy (mean age, 66.1 ± 6.8 years; mean, 67%; mean FEV1, 0.78 ± 0.25 L). Results: At 6 months, LVRS patients had higher maximum V̇e (32.8 vs 29.6 L/min, respectively; p = 0.001), V̇co2, (0.923 vs 0.820 L/min, respectively; p = 0.0003), Vt (1.18 vs 1.07 L, respectively; p = 0.001), heart rate (124 vs 121 beats/min, respectively; p = 0.02), and workload (49.3 vs 45.1 W, respectively; p = 0.04), but less breathlessness (as measured by Borg dyspnea scale score) [4.4 vs 5.2, respectively; p = 0.0001] and exercise ventilatory limitation (49.5% vs 71.9%, respectively; p = 0.001) than medical patients. LVRS patients with upper-lobe emphysema showed a downward shift in Paco2 vs V̇co2 (p = 0.001). During exercise, LVRS patients breathed slower and deeper at 6 months (p = 0.01) and 12 months (p = 0.006), with reduced dead space at 6 months (p = 0.007) and 24 months (p = 0.006). Twelve months after patients underwent LVRS, dyspnea was less in patients with upper-lobe emphysema (p = 0.001) and non–upper-lobe emphysema (p = 0.007). Conclusion: During exercise following LVRS, patients with severe emphysema improve carbon dioxide elimination and dead space, breathe slower and deeper, and report less dyspnea

  17. Prospects for energy efficiency improvement and reduction of emissions and life cycle costs for natural gas vehicles

    NASA Astrophysics Data System (ADS)

    Kozlov, A. V.; Terenchenko, A. S.; Luksho, V. A.; Karpukhin, K. E.

    2017-01-01

    This work is devoted to the experimental investigation of the possibilities to reduce greenhouse gas emissions and to increase energy efficiency of engines that use natural gas as the main fuel and the analysis of economic efficiency of use of dual fuel engines in vehicles compared to conventional diesel. The results of experimental investigation of a 190 kW dual-fuel engine are presented; it is shown that quantitative and qualitative working process control may ensure thermal efficiency at the same level as that of the diesel engine and in certain conditions 5...8% higher. The prospects for reduction of greenhouse gas emissions have been assessed. The technical and economic evaluation of use of dual fuel engines in heavy-duty vehicles has been performed, taking into account the total life cycle. It is shown that it is possible to reduce life cycle costs by two times.

  18. ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE REACTOR SYSTEM - APPLICATIONS ANALYSIS REPORT

    EPA Science Inventory

    The ELI Eco Logic International Inc. (Eco Logic) process thermally separates organics, then chemically reduces them in a hydrogen atmosphere, converting them to a reformed gas that consists of light hydrocarbons and water. A scrubber treats the reformed gas to remove hydrogen chl...

  19. New chemical additive to enhance reduction of oil carryover in gas

    SciTech Connect

    Khatib, Z.I.

    1998-12-31

    Foaming and fouling in glycol contactors and/or in amine treating systems are frequent problems in gas treatment processes due to the entrainment of liquid and solid aerosols in the gas stream. Entrainment of these aerosols leads also to mechanical damage of turbines and/or unscheduled shutdown of compressor units. A new chemical additive was developed and applied in the gas stream. The additive was successful in preventing the dissemination of the oil and/or condensate carryover into aerosol sizes, thereby enhancing the performance of coalescer filters and scrubbers.

  20. An investigation of gas separation membranes for reduction of thermal treatment emissions

    SciTech Connect

    Stull, D.M.; Logsdon, B.W.; Pellegrino, J.J.

    1994-05-16

    Gas permeable membranes were evaluated for possible use as air pollution control devices on a fluidized bed catalytic incineration unit. The unit is a candidate technology for treatment of certain mixed hazardous and radioactive wastes at the Rocky Flats Plant. Cellulose acetate and polyimide membranes were tested to determine the permeance of typical off-gas components such as carbon dioxide, nitrogen, and oxygen. Multi-component permeation studies included gas mixtures containing light hydrocarbons. Experiments were also conducted to discover information about potential membrane degradation in the presence of organic compounds.

  1. Evaluation of Drag Reduction via Superhydrophobic Surfaces and Active Gas Replenishment in a Fully-developed Turbulent Flow

    NASA Astrophysics Data System (ADS)

    Gose, James W.; Golovin, Kevin; Ceccio, Steven L.; Perlin, Marc; Tuteja, Anish

    2014-11-01

    The development of superhydrophobic surfaces (SHS) for skin-friction drag reduction in the laminar regime has shown great promise. A team led by the University of Michigan is examining the potential of similar SHS in high-speed naval applications. Specifically, we have developed a recirculating facility to investigate the reduction of drag along robustly engineered SHS in a fully-developed turbulent boundary layer flow. The facility can accommodate both small and large SHS samples in a test section 7 mm (depth) × 100 mm (span) × 1200 mm (length). Coupled with an 11.2 kilowatt pump and a 30:1 contraction, the facility is capable of producing an average flow velocity of 20 m/s, yielding a height based (7 mm) Reynolds number of 140,000. The SHS tested were designed for large-scale application. The present investigation shows skin-friction drag reduction for various sprayable and chemically developed SHS that were applied over a 100 mm (span) × 1100 mm (length) area. The drag measurement methods include pressure drop across the test specimen and PIV measured boundary layers. Additional SHS investigations include the implementation of active gas replenishment, providing an opportunity to replace gas-pockets that would otherwise be disrupted in traditional passive SHS due to high shear stress and turbulent pressure fluctuations. Gas is evenly distributed through a 90 mm (span) × 600 mm (length) sintered porous media with pore sizes of 10 to 100 microns. The impact of the active gas replenishment is being evaluated with and without SHS.

  2. A predictive mechanism for mercury oxidation on selective catalytic reduction catalysts under coal-derived flue gas

    SciTech Connect

    Stephen Niksa; Naoki Fujiwara

    2005-12-15

    This paper introduces a predictive mechanism for elemental mercury (Hg{sup 0}) oxidation on selective catalytic reduction (SCR) catalysts in coal-fired utility gas cleaning systems, given the ammonia (NH{sub 3})/nitric oxide (NO) ratio and concentrations of Hg{sup 0} and HCl at the monolith inlet, the monolith pitch and channel shape, and the SCR temperature and space velocity. A simple premise connects the established mechanism for catalytic NO reduction to the Hg{sup 0} oxidation behavior on SCRs: that hydrochloric acid (HCl) competes for surface sites with NH{sub 3} and that Hg{sup 0} contacts these chlorinated sites either from the gas phase or as a weakly adsorbed species. This mechanism explicitly accounts for the inhibition of Hg{sup 0} oxidation by NH{sub 3}, so that the monolith sustains two chemically distinct regions. In the inlet region, strong NH{sub 3} adsorption minimizes the coverage of chlorinated surface sites, so NO reduction inhibits Hg{sup 0} oxidation. But once NH{sub 3} has been consumed, the Hg{sup 0} oxidation rate rapidly accelerates, even while the HCl concentration in the gas phase is uniform. Factors that shorten the length of the NO reduction region factors that enhance surface chlorination, promote Hg{sup 0} oxidation. This mechanism accurately interprets the reported tendencies for greater extents of Hg{sup 0} oxidation on honeycomb monoliths with smaller channel pitches and hotter temperatures and the tendency for lower extents of Hg{sup 0} oxidation for hotter temperatures on plate monoliths. The mechanism reproduces the reported extents of Hg{sup 0} oxidation on a single catalyst for four coals that generated HCl concentrations from 8 to 241 ppm, which covers the entire range encountered in the U.S. utility industry. Similar performance is also demonstrated for full-scale SCRs with diverse coal types and operating conditions. 28 refs., 5 figs., 3 tabs.

  3. FROM THE COLOR-MAGNITUDE DIAGRAM OF {omega} CENTAURI AND (SUPER-)ASYMPTOTIC GIANT BRANCH STELLAR MODELS TO A GALACTIC PLANE PASSAGE GAS PURGING CHEMICAL EVOLUTION SCENARIO

    SciTech Connect

    Herwig, Falk; VandenBerg, Don A.; Navarro, Julio F.; Ferguson, Jason; Paxton, Bill E-mail: vandenbe@uvic.ca E-mail: paxton@kitp.ucsb.edu

    2012-10-01

    We have investigated the color-magnitude diagram of {omega} Centauri and find that the blue main sequence (bMS) can be reproduced only by models that have a helium abundance in the range Y = 0.35-0.40. To explain the faint subgiant branch of the reddest stars ('MS-a/RG-a' sequence), isochrones for the observed metallicity ([Fe/H] Almost-Equal-To -0.7) appear to require both a high age ({approx}13 Gyr) and enhanced CNO abundances ([CNO/Fe] Almost-Equal-To 0.9). Y Almost-Equal-To 0.35 must also be assumed in order to counteract the effects of high CNO on turnoff colors and thereby to obtain a good fit to the relatively blue turnoff of this stellar population. This suggests a short chemical evolution period of time (<1 Gyr) for {omega} Cen. Our intermediate-mass (super-)asymptotic giant branch (AGB) models are able to reproduce the high helium abundances, along with [N/Fe] {approx}2 and substantial O depletions if uncertainties in the treatment of convection are fully taken into account. These abundance features distinguish the bMS stars from the dominant [Fe/H] Almost-Equal-To -1.7 population. The most massive super-AGB stellar models (M{sub ZAMS} {>=} 6.8 M{sub Sun }, M{sub He,core} {>=} 1.245 M{sub Sun }) predict too large N enhancements, which limit their role in contributing to the extreme populations. In order to address the observed central concentration of stars with He-rich abundance, we show here quantitatively that highly He- and N-enriched AGB ejecta have particularly efficient cooling properties. Based on these results and on the reconstruction of the orbit of {omega} Cen with respect to the Milky Way, we propose the Galactic plane passage gas purging scenario for the chemical evolution of this cluster. The bMS population formed shortly after the purging of most of the cluster gas as a result of the passage of {omega} Cen through the Galactic disk (which occurs today every {approx}40 Myr for {omega} Cen) when the initial mass function of the dominant

  4. Learning from global emissions scenarios

    NASA Astrophysics Data System (ADS)

    O'Neill, Brian C.; Nakicenovic, Nebojsa

    2008-10-01

    Scenarios of global greenhouse gas emissions have played a key role in climate change analysis for over twenty years. Currently, several research communities are organizing to undertake a new round of scenario development in the lead-up to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). To help inform this process, we assess a number of past efforts to develop and learn from sets of global greenhouse gas emissions scenarios. We conclude that while emissions scenario exercises have likely had substantial benefits for participating modeling teams and produced insights from individual models, learning from the exercises taken as a whole has been more limited. Model comparison exercises have typically focused on the production of large numbers of scenarios while investing little in assessing the results or the production process, perhaps on the assumption that later assessment efforts could play this role. However, much of this assessment potential remains untapped. Efforts such as scenario-related chapters of IPCC reports have been most informative when they have gone to extra lengths to carry out more specific comparison exercises, but in general these assessments do not have the remit or resources to carry out the kind of detailed analysis of scenario results necessary for drawing the most useful conclusions. We recommend that scenario comparison exercises build-in time and resources for assessing scenario results in more detail at the time when they are produced, that these exercises focus on more specific questions to improve the prospects for learning, and that additional scenario assessments are carried out separately from production exercises. We also discuss the obstacles to better assessment that might exist, and how they might be overcome. Finally, we recommend that future work include much greater emphasis on understanding how scenarios are actually used, as a guide to improving scenario production.

  5. Greenhouse Gas Emission Reduction Due to Improvement of Biodegradable Waste Management System

    NASA Astrophysics Data System (ADS)

    Bendere, R.; Teibe, I.; Arina, D.; Lapsa, J.

    2014-12-01

    To reduce emissions of greenhouse gas (GHG) from landfills, the European Union (EU) Landfill Directive 1999/31/EC requires that there be a progressive decrease in the municipal biodegradable waste disposal. The main problem of waste management (WM) in Latvia is its heavy dependence on the waste disposal at landfills. The poorly developed system for the sorted municipal waste collection and the promotion of landfilling as a major treatment option led to the disposal of 84% of the total collected municipal waste in 2012, with a high biodegradable fraction. In Latvia, the volume of emissions due to activities of the WM branch was 5.23% (632.6 CO2 eq.) of the total GHG emissions produced in the National economy in 2010 (12 097 Gg CO2 eq., except the land use, land-use change and forestry). Having revised the current situation in the management of biodegradable waste in Latvia, the authors propose improvements in this area. In the work, analysis of environmental impact was carried out using Waste Management Planning System (WAMPS) software in the WM modelling scenarios. The software computes the emissions, energy and turnover of waste streams for the processes within the WM system such as waste collection and transportation, composting, anaerobic digestion, and the final disposal (landfilling or incineration). The results of WAMPS modelling are presented in four categories associated with the environmental impact: acidification, global warming, eutrophication and photo-oxidant formation, each characterised by a particular emission. These categories cover an integrated WM system, starting with the point when products turn to waste which is then thrown into the bin for waste at its generation source, and ending with the point where the waste transforms either into useful material (recycled material, biogas or compost) or contributes to emissions into environment after the final disposal at a landfill or an incineration plant Rakstā veikts pašvaldības bioloģiski no

  6. Assessing carbon stocks, carbon sequestration, and greenhouse-gas fluxes in ecosystems of the United States under present conditions and future scenarios

    USGS Publications Warehouse

    Zhu, Zhi-Liang; Stackpoole, Sarah

    2011-01-01

    The Energy Independence and Security Act of 2007 (EISA) requires the U.S. Department of the Interior (DOI) to develop a methodology and conduct an assessment of carbon storage, carbon sequestration, and greenhouse-gas (GHG) fluxes in the Nation's ecosystems. The U.S. Geological Survey (USGS) has developed and published the methodology (U.S. Geological Survey Scientific Investigations Report 2010-5233) and has assembled an interdisciplinary team of scientists to conduct the assessment over the next three to four years, commencing in October 2010. The assessment will fulfill specific requirements of the EISA by (1) quantifying, measuring, and monitoring carbon sequestration and GHG fluxes using national datasets and science tools such as remote sensing, and biogeochemical and hydrological models, (2) evaluating a range of management and restoration activities for their effects on carbon-sequestration capacity and the reduction of GHG fluxes, and (3) assessing effects of climate change and other controlling processes (including wildland fires) on carbon uptake and GHG emissions from ecosystems.

  7. [Noise in intensive care units. Noise reduction by modification of gas humidification].

    PubMed

    Berg, P W; Stuttmann, R; Doehn, M

    1997-10-01

    Today, noise pollution is an evident and ubiquitous problem even in intensive care units. Noise can disturb the physiological and psychological balance in patients and staff. Especially intubated patients and those breathing spontaneously through a T-piece are exposed to the noise emitted by the nebuliser used to humidity the respiratory gas. This may make patients feel uncomfortable. To reduce noise pollution in the ICU a modified T-piece has been developed and investigated. In order to heat and humidity the respiratory gas a Conchaterm III unit (Kendall company) and a thermo flow cylinder (De Vilbiss company) is necessary. While respiratory gas is flowing, water is sucked out of the heated thermoflow cylinder and nebulised according to the Venturi-Bernoulli principle. To adjust the oxygen concentration of the respiratory gas a plastic ring must be turned to either close (98% oxygen) or open a valve allowing room air to mix (40% oxygen). Noise pollution of the unit varies with admixture of room air. With a new device--a special oxygen-air mixing chamber--the oxygen concentration of the respiratory gas can be adjusted outside the thermoflow cylinder, hardly producing any noise pollution. Therefore the principle of nebulisation could be changed to humidification. A thermoflow cylinder without the nebulisation unit allows the respiratory gas to flow through the thermoflow cylinder over heated and evaporating water, hardly causing any noise pollution. In both types of T-pieces the temperature of the respiratory gas is controlled and corrected by the Conchaterm unit. As the result of these modifications, noise pollution has been reduced from 70 dB(A) to 55 dB(A). In the modified T-piece, the quality of humidification has been evaluated with a fresh gas flow of 22 l/min and at a gas temperature of 37 degrees C, not only collecting condensed water but also lost water. The modified T-piece allows a physiological humidification of the respiratory gas. The modified T

  8. Emergency management response to a warning-level Alaska-source tsunami impacting California: Chapter J in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Miller, Kevin M.; Long, Kate

    2013-01-01

    This chapter is directed towards two audiences: Firstly, it targets nonemergency management readers, providing them with insight on the process and challenges facing emergency managers in responding to tsunami Warning, particularly given this “short fuse” scenario. It is called “short fuse” because there is only a 5.5-hour window following the earthquake before arrival of the tsunami within which to evaluate the threat, disseminate alert and warning messages, and respond. This action initiates a period when crisis communication is of paramount importance. An additional dynamic that is important to note is that within 15 minutes of the earthquake, the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS) will issue alert bulletins for the entire Pacific Coast. This is one-half the time actually presented by recent tsunamis from Japan, Chile, and Samoa. Second, the chapter provides emergency managers at all levels with insights into key considerations they may need to address in order to augment their existing plans and effectively respond to tsunami events. We look at emergency management response to the tsunami threat from three perspectives:“Top Down” (Threat analysis and Alert/Warning information from the Federal agency charged with Alert and Warning) “Bottom Up” (Emergency management’s Incident Command approach to responding to emergencies and disasters based on the needs of impacted local jurisdictions) “Across Time” (From the initiating earthquake event through emergency response) We focus on these questions: What are the government roles, relationships, and products that support Tsunami Alert and Warning dissemination? (Emergency Planning and Preparedness.) What roles, relationships, and products support emergency management response to Tsunami Warning and impact? (Engendering prudent public safety response.) What are the key emergency management activities, considerations, and challenges brought

  9. Joint implementation as a financing instrument for global reductions in greenhouse gas emissions

    SciTech Connect

    Metz, B.

    1995-11-01

    Joint implementation is based on the idea of cost-effectiveness by providing parties with the opportunity to partially off-set their own emissions with cheaper reductions achieved elsewhere. Joint implementation can be defined as realization of reduction emissions by one investor on the territory of another. Joint implementation could contribute to the North-South cooperation that is embedded in the Climate Convention.

  10. Effect of additives on Hg2+ reduction and precipitation inhibited by sodium dithiocarbamate in simulated flue gas desulfurization solutions.

    PubMed

    Lu, Rongjie; Hou, Jiaai; Xu, Jiang; Tang, Tingmei; Xu, Xinhua

    2011-11-30

    Mercury (II) (Hg(2+)) ion can be reduced by aqueous S(IV) (sulfite and/or bisulfite) species, which leads to elemental mercury (Hg(0)) emissions in wet flue gas desulfurization (FGD) systems. Numerous reports have demonstrated the high trapping efficiency of sodium dithiocarbamate over heavy metals. In this paper, a novel sodium dithiocarbamate, DTCR, was utilized as a precipitator to control Hg(2+) reduction and Hg(0) emission against S(IV) in FGD solutions. Results indicated that Hg(2+) reduction efficiency decreased dramatically while precipitation rate peaked at around 91.0% in consistence with the increment of DTCR dosage. Initial pH and temperature had great inhibitory effects on Hg(2+) reduction: the Hg(2+) removal rate gradually increased and reached a plateau along with the increment of temperature and initial pH value. Chloride played a key role in Hg(2+) reduction and precipitation reactions. When Cl(-) concentration increased from 0 to 150 mM, Hg(2+) removal rate dropped from 93.84% to 86.05%, and the Hg(2+) reduction rate remained at a low level (<7.8%). SO(4)(2-), NO(3)(-) and other common metal ions would affect the efficiency of Hg(2+) reduction and precipitation reactions in the simulated desulfurization solutions: Hg(2+) removal rate could always be above 90%, while Hg(2+) reduction rate was maintained at below 10%. The predominance of DTCR over aqueous S(IV), indicated by the results above, has wide industrial applications in FGD systems.

  11. Reduction behavior of zinc ferrite in EAF-dust recycling with CO gas as a reducing agent.

    PubMed

    Wu, Chia-Cheng; Chang, Fang-Chih; Chen, W-S; Tsai, Min-Shing; Wang, Ya-Nang

    2014-10-01

    EAF-dust containing metal oxides can be regarded as an important source for zinc and iron. In this study, the reduction behavior of zinc ferrite with CO gas as a reducing agent under different temperatures was investigated to develop a new process for the recovery of zinc and iron from EAF-dust. The results of the phase studies with synthetic franklinite show that zinc substituted wustite, and spinel with low zinc content formed at lower temperatures from 450 to 850 °C due to incomplete zinc-iron-separation. Zinc ferrite was completely reduced to metallic zinc and iron at 950 °C. After evaporation and condensation, metallic zinc was collected in the form of zinc powder while iron, the reduction residue, was obtained in the form of direct reduced iron (DRI). The mass balance indicates a high zinc recovery ratio of over 99%. The new treatment process by thermal reduction with CO gas as a reducing agent achieved higher recovery and metallization grade of both zinc and iron from EAF-dust at lower temperatures than other commercial processes. The metallic products can be used directly as semi-products or as raw materials for refinery.

  12. Reduction of Prostate Motion by Removal of Gas in Rectum During Radiotherapy

    SciTech Connect

    Ogino, Ichiro Uemura, Hiroji; Inoue, Tomio; Kubota, Yoshinobu; Nomura, Kazuto R.T.T.; Okamoto, Naoyuki

    2008-10-01

    Purpose: To evaluate the prostate and seminal vesicle motion in patients during both simulation and radiotherapy by rectal gas removal. Methods and Materials: A total of 34 patients were treated in a whole pelvic radiotherapy (WPRT) arm and 42 patients in a non-WPRT arm. Of the 76 patients, 42 (26 in the non-WPRT arm and 16 in the WPRT arm) were instructed to insert their index finger and wash their rectums to evacuate their rectal gas. In addition to the planning computed tomography scan, three subsequent computed tomography scans were obtained during RT. The organs were outlined on each computed tomography image. Changes in the position of the prostate and seminal vesicles were analyzed using the center of mass (COM) coordinate system. The time trend, overall variations, systematic variations, and random variations were analyzed. Results: The average cross-sectional area in the rectal gas removal group was significantly smaller than in all patients and in the WPRT arm. The vector of the prostate and seminal vesicle displacement for the rectal gas removal group was significantly smaller than in all patients. With rectal gas removal, the 95% confidence limit of the prostate displacement vector was reduced by 2.3 mm in the non-WPRT arm and 2.9 mm in the WPRT arm. The 95% confidence limit of the seminal vesicle displacement vector was reduced by 0.3 mm in the non-WPRT arm and 4.4 mm in the WPRT arm. Conclusions: Using rectal gas removal, the cross-sectional area could be decreased, resulting in reduced motion and margins for the prostate and seminal vesicles. This is especially important for WPRT patients who require RT to the prostate, seminal vesicles, and pelvic lymph nodes.

  13. Greenhouse gas reduction and improved sustainability of animal husbandry using amino acids in swine, poultry feeds.

    PubMed

    Tsujimoto, Susumu; Takagi, Tomo; Osada, Takashi; Ogino, Akifumi

    2013-05-01

    In Annex 1 countries, nitrous oxide (N2 O) emissions from swine and poultry excreta have been calculated and the N2 O reduction potential of each country by using amino acids in feed could also be calculated, then a comparison made among the countries. The N2 O reduction rates were approximately 25% for these Annex 1 countries and amino acids were able to make a large contribution to that reduction. Greenhouse gases (GHG) which are N2 O combined with methane (CH4 ) were estimated to reduce by 24.8% in Japan when amino acids were introduced into the feed, but only a 7.2% reduction was estimated in France. Purification, which is mainly used for manure treatment in Japan, emits much more N2 O and less CH4 , whereas the liquid system which is mainly used in France emits more CH4 and less N2 O based on the emission factors from the United Nations Framework Convention on Climate Change data base. Changing the French manure treatment system to the Japanese style with amino acids in feed would reduce GHG emissions by 23.4%. Reduction of the arable land use in Japan by changing crop formulations supported by adding amino acids to feed was also quantified as about 10% and led to an increase in the production of meat using the same arable land area.

  14. Biological sulfate reduction using gas-lift reactors fed with hydrogen and carbon dioxide as energy and carbon source

    SciTech Connect

    Houten, R.T. van; Hulshoff Pol, L.W.; Lettinga, G. . Dept. of Environmental Technology)

    1994-08-20

    Feasibility and engineering aspects of biological sulfate reduction in gas-lift reactors were studied. Hydrogen and carbon dioxide were used as energy and carbon source. Attention was paid to biofilm formation, sulfide toxicity, sulfate conversion rate optimization, and gas-liquid mass transfer limitations. Sulfate-reducing bacteria formed stable biofilms on pumice particles. Biofilm formation was not observed when basalt particles were used. However, use of basalt particles led to the formation of granules of sulfate-reducing biomass. The sulfate-reducing bacteria, grown on pumice, easily adapted to free H[sub 2]S concentrations up to 450 mg/L. Biofilm growth rate then equilibrated biomass loss rate. These high free H[sub 2]S concentrations caused reversible inhibition rather than acute toxicity. When free H[sub 2]S concentrations were kept below 450 mg/L, a maximum sulfate conversion rate of 30 g SO[sub 4][sup 2[minus

  15. Effect of liming on sulfate transformation and sulfur gas emissions in degraded vegetable soil treated by reductive soil disinfestation.

    PubMed

    Meng, Tianzhu; Zhu, Tongbin; Zhang, Jinbo; Cai, Zucong

    2015-10-01

    Reductive soil disinfestation (RSD), namely amending organic materials and mulching or flooding to create strong reductive status, has been widely applied to improve degraded soils. However, there is little information available about sulfate (SO4(2-)) transformation and sulfur (S) gas emissions during RSD treatment to degraded vegetable soils, in which S is generally accumulated. To investigate the effects of liming on SO4(2-) transformation and S gas emissions, two SO4(2-)-accumulated vegetable soils (denoted as S1 and S2) were treated by RSD, and RSD plus lime, denoted as RSD0 and RSD1, respectively. The results showed that RSD0 treatment reduced soil SO4(2-) by 51% and 61% in S1 and S2, respectively. The disappeared SO4(2-) was mainly transformed into the undissolved form. During RSD treatment, hydrogen sulfide (H2S), carbonyl sulfide (COS), and dimethyl sulfide (DMS) were detected, but the total S gas emission accounted for <0.006% of total S in both soils. Compared to RSD0, lime addition stimulated the conversion of SO4(2-) into undissolved form, reduced soil SO4(2-) by 81% in S1 and 84% in S2 and reduced total S gas emissions by 32% in S1 and 57% in S2, respectively. In addition to H2S, COS and DMS, the emissions of carbon disulfide, methyl mercaptan, and dimethyl disulfide were also detected in RSD1 treatment. The results indicated that RSD was an effective method to remove SO4(2-), liming stimulates the conversion of dissolved SO4(2-) into undissolved form, probably due to the precipitation with calcium.

  16. Greenhouse gas reductions through enhanced use of residues in the life cycle of Malaysian palm oil derived biodiesel.

    PubMed

    Hansen, Sune Balle; Olsen, Stig Irving; Ujang, Zaini

    2012-01-01

    This study identifies the potential greenhouse gas (GHG) reductions, which can be achieved by optimizing the use of residues in the life cycle of palm oil derived biodiesel. This is done through compilation of data on existing and prospective treatment technologies as well as practical experiments on methane potentials from empty fruit bunches. Methane capture from the anaerobic digestion of palm oil mill effluent was found to result in the highest GHG reductions. Among the solid residues, energy extraction from shells was found to constitute the biggest GHG savings per ton of residue, whereas energy extraction from empty fruit bunches was found to be the most significant in the biodiesel production life cycle. All the studied waste treatment technologies performed significantly better than the conventional practices and with dedicated efforts of optimized use in the palm oil industry, the production of palm oil derived biodiesel can be almost carbon neutral.

  17. Direct reduction of carbon dioxide to formate in high-gas-capacity ionic liquids at post-transition-metal electrodes.

    PubMed

    Watkins, John D; Bocarsly, Andrew B

    2014-01-01

    As an approach to combat the increasing emissions of carbon dioxide in the last 50 years, the sequestration of carbon dioxide gas in ionic liquids has become an attractive research area. Ionic liquids can be made that possess incredibly high molar absorption and specificity characteristics for carbon dioxide. Their high carbon dioxide solubility and specificity combined with their high inherent electrical conductivity also creates an ideal medium for the electrochemical reduction of carbon dioxide. Herein, a lesser studied ionic liquid, 1-ethyl-3-methylimidazolium trifluoroacetate, was used as both an effective carbon dioxide capture material and subsequently as an electrochemical matrix with water for the direct reduction of carbon dioxide into formate at indium, tin, and lead electrodes in good yield (ca. 3 mg h(-1) cm(-2)).

  18. Potential of municipal solid waste for renewable energy production and reduction of greenhouse gas emissions in South Korea.

    PubMed

    Ryu, Changkook

    2010-02-01

    Energy from waste (EfW) for nonrecyclable wastes is a suitable method of waste management and is important for renewable energy production. South Korea currently recycles 57% of household waste and landfills 26%. The remaining 17% is incinerated, mainly for heat production. In this study, the potential for energy production and reduction of corresponding greenhouse gas (GHG) emissions from municipal solid waste (MSW) in Korea was estimated without accounting for the lifecycle impact of waste management. The properties of the MSW were established from data available in national-scale waste surveys and reports. The potential of EfW for GHG emission reduction was calculated considering (1) the direct release of anthropogenic carbon, nitrous oxide (N2O), and methane (CH4); and (2) the reduction in indirect GHG emissions by fossil fuel displacement. CH4 emissions from landfilling were also estimated from biogenic carbon in waste. Applying the resulting emission factors to various EfW cases suggests that the current level of GHG emissions is significant but can be substantially reduced by increased use of EfW. A net reduction in GHG emissions can be achieved only by EfW with combined heat and power (CHP).

  19. The SAFRR Tsunami Scenario

    USGS Publications Warehouse

    Porter, K.; Jones, Lucile M.; Ross, Stephanie L.; Borrero, J.; Bwarie, J.; Dykstra, D.; Geist, Eric L.; Johnson, L.; Kirby, Stephen H.; Long, K.; Lynett, P.; Miller, K.; Mortensen, Carl E.; Perry, S.; Plumlee, G.; Real, C.; Ritchie, L.; Scawthorn, C.; Thio, H.K.; Wein, Anne; Whitmore, P.; Wilson, R.; Wood, Nathan J.; Ostbo, Bruce I.; Oates, Don

    2013-01-01

    The U.S. Geological Survey and several partners operate a program called Science Application for Risk Reduction (SAFRR) that produces (among other things) emergency planning scenarios for natural disasters. The scenarios show how science can be used to enhance community resiliency. The SAFRR Tsunami Scenario describes potential impacts of a hypothetical, but realistic, tsunami affecting California (as well as the west coast of the United States, Alaska, and Hawaii) for the purpose of informing planning and mitigation decisions by a variety of stakeholders. The scenario begins with an Mw 9.1 earthquake off the Alaska Peninsula. With Pacific basin-wide modeling, we estimate up to 5m waves and 10 m/sec currents would strike California 5 hours later. In marinas and harbors, 13,000 small boats are damaged or sunk (1 in 3) at a cost of $350 million, causing navigation and environmental problems. Damage in the Ports of Los Angeles and Long Beach amount to $110 million, half of it water damage to vehicles and containerized cargo. Flooding of coastal communities affects 1800 city blocks, resulting in $640 million in damage. The tsunami damages 12 bridge abutments and 16 lane-miles of coastal roadway, costing $85 million to repair. Fire and business interruption losses will substantially add to direct losses. Flooding affects 170,000 residents and workers. A wide range of environmental impacts could occur. An extensive public education and outreach program is underway, as well as an evaluation of the overall effort.

  20. Economic Potential of Greenhouse Gas Emission Reductions: Comparative Role for Soil Sequestration in Agriculture and Forestry

    SciTech Connect

    Mccarl, Bruce A.; Schneider, Uwe; Murray, Brian; Williams, Jimmy; Sands, Ronald D.

    2001-05-14

    This paper examines the relative contribution of agricultural and forestry activities in an emission reduction program, focusing in part on the relative desirability of sequestration in forests and agricultural soils. The analysis considers the effects of competition for land and other resources between agricultural activities, forestry activities and traditional production. In addition, the paper examines the influence of saturation and volatility.

  1. Model study of the impact of biogenic emission on regional ozone and the effectiveness of emission reduction scenarios over eastern China

    NASA Astrophysics Data System (ADS)

    Han, Zhiwei; Ueda, Hiromasa; Matsuda, Kazuhide

    2005-02-01

    The impact of biogenic emission on regional ozone and emission control scenarios has been numerically studied through a series of sensitivity model simulations. A typical episode with elevated ozone over eastern China from 12 to 16 August 2001 was investigated by using a tropospheric chemistry and transport model (TCTM), driven by a non-hydrostatic mesoscale model MM5. The meteorological conditions during this period were characterized by high-pressure systems associated with low wind speeds, high temperatures and clear skies. Afternoon ozone concentrations exceeding 80 parts per billion (ppb) occurred over broad areas of eastern China. There is a generally good agreement between simulation and observation, indicating that the TCTM is able to represent major physical and chemical processes of tropospheric ozone and well reproduce the diurnal and day-to-day variability associated with synoptic conditions. The sensitivity analysis reveals a significant influence of biogenic hydrocarbons on regional ozone. Ozone levels are apparently enhanced by biogenic emission over large areas of eastern China. The largest increase up to 30 ppb in daytime average concentration is found in portions of the middle reaches of the Yangtze River, Yangtze Delta and northeast China. However, the response of ozone to biogenic emission varies spatially, showing more sensitivity in polluted areas than that in clean rural areas. The regimes limited by nitrogen oxides (NOx) and volatile organic carbon (VOC) in eastern China are further investigated with respect to biogenic emission. Ozone shows a clear tendency to shift from VOC limitation to NOx limitation as it moves from urban and industrial areas to rural areas. Most of the rural areas in southern China tend to be NOx limited, whereas most of the northern parts of China appear to be VOC limited. By considering biogenic emission, ozone tends to become more NOx limited and less VOC limited, both in extent and intensity, over eastern china

  2. Advanced Exploration Systems Logistics Reduction and Repurposing Trash-to-Gas and Heat Melt Compactor KSC

    NASA Technical Reports Server (NTRS)

    Caraccio, Anne J.; Layne, Andrew; Hummerick, Mary

    2013-01-01

    Topics covered: 1. Project Structure 2. "Trash to Gas" 3. "Smashing Trash! The Heat Melt Compactor" 4. "Heat Melt Compaction as an Effective Treatment for Eliminating Microorganisms from Solid Waste" Thermal degradation of trash reduces volume while creating water, carbon dioxide and ash. CO2 can be fed to Sabatier reactor for CH4 production to fuel LOX/LCH4 ascent vehicle. Optimal performance: HFWS, full temperature ramp to 500-600 C. Tar challenges exist. Catalysis: Dolomag did eliminate allene byproducts from the product stream. 2nd Gen Reactor Studies. Targeting power, mass, time efficiency. Gas separation, Catalysis to reduce tar formation. Microgravity effects. Downselect in August will determine where we should spend time optimizing the technology.

  3. Greenhouse gas emission reduction and environmental quality improvement from implementation of aerobic waste treatment systems in swine farms.

    PubMed

    Vanotti, M B; Szogi, A A; Vives, C A

    2008-01-01

    Trading of greenhouse gas (GHG) emission reductions is an attractive approach to help producers implement cleaner treatment technologies to replace current anaerobic lagoons. Our objectives were to estimate greenhouse gas (GHG) emission reductions from implementation of aerobic technology in USA swine farms. Emission reductions were calculated using the approved United Nations framework convention on climate change (UNFCCC) methodology in conjunction with monitoring information collected during full-scale demonstration of the new treatment system in a 4360-head swine operation in North Carolina (USA). Emission sources for the project and baseline manure management system were methane (CH4) emissions from the decomposition of manure under anaerobic conditions and nitrous oxide (N2O) emissions during storage and handling of manure in the manure management system. Emission reductions resulted from the difference between total project and baseline emissions. The project activity included an on-farm wastewater treatment system consisting of liquid-solid separation, treatment of the separated liquid using aerobic biological N removal, chemical disinfection and soluble P removal using lime. The project activity was completed with a centralized facility that used aerobic composting to process the separated solids. Replacement of the lagoon technology with the cleaner aerobic technology reduced GHG emissions 96.9%, from 4972 tonnes of carbon dioxide equivalents (CO2-eq) to 153 tonnes CO2-eq/year. Total net emission reductions by the project activity in the 4360-head finishing operation were 4776.6 tonnes CO2-eq per year or 1.10 tonnes CO2-eq/head per year. The dollar value from implementation of this project in this swine farm was US$19,106/year using current Chicago Climate Exchange trading values of US$4/t CO2. This translates into a direct economic benefit to the producer of US$1.75 per finished pig. Thus, GHG emission reductions and credits can help compensate for the

  4. Carrier dynamics and the role of surface defects: Designing a photocatalyst for gas-phase CO2 reduction

    DOE PAGES

    Hoch, Laura B.; Szymanski, Paul; Ghuman, Kulbir Kaur; ...

    2016-11-28

    In2O3-x(OH)y nanoparticles have been shown to function as an effective gas-phase photocatalyst for the reduction of CO2 to CO via the reverse water–gas shift reaction. Their photocatalytic activity is strongly correlated to the number of oxygen vacancy and hydroxide defects present in the system. To better understand how such defects interact with photogenerated electrons and holes in these materials, we have studied the relaxation dynamics of In2O3-x(OH)y nanoparticles with varying concentration of defects using two different excitation energies corresponding to above-band-gap (318-nm) and near-band-gap (405-nm) excitations. Our results demonstrate that defects play a significant role in the excited-state, charge relaxationmore » pathways. Higher defect concentrations result in longer excited-state lifetimes, which are attributed to improved charge separation. This correlates well with the observed trends in the photocatalytic activity. These results are further supported by density-functional theory calculations, which confirm the positions of oxygen vacancy and hydroxide defect states within the optical band gap of indium oxide. This enhanced understanding of the role these defects play in determining the optoelectronic properties and charge carrier dynamics can provide valuable insight toward the rational development of more efficient photocatalytic materials for CO2 reduction.« less

  5. Effect of Precursor Selection on the Photocatalytic Performance of Indium Oxide Nanomaterials for Gas-Phase CO 2 Reduction

    DOE PAGES

    Hoch, Laura B.; He, Le; Qiao, Qiao; ...

    2016-06-01

    Nonstoichiometric indium oxide nanoparticles, In2O3–x(OH)y, have been shown to function as active photocatalysts for gas-phase CO2 reduction under simulated solar irradiation. We demonstrate that the choice of starting material has a strong effect on the photocatalytic activity of indium oxide nanoparticles. We also examine three indium oxide materials prepared via the thermal decomposition of either indium(III) hydroxide or indium(III) nitrate and correlate their stability and photocatalytic activity to the number and type of defect present in the material. Furthermore, we use 13CO2 isotope-tracing experiments to clearly identify the origins of the observed carbon-containing products. Significantly, we find that the oxidizingmore » nature of the precursor anion has a substantial impact on the defect formation within the sample. Our study demonstrates the importance of surface defects in designing an active heterogeneous photocatalyst and provides valuable insight into key parameters for the precursor design, selection, and performance optimization of materials for gas-phase CO2 reduction.« less

  6. Solvent-Induced Reductive Activation in Gas Phase [Bi(CO2)n]- Clusters

    NASA Astrophysics Data System (ADS)

    Thompson, Michael C.; Ramsay, Jacob Sondergaard; Weber, J. Mathias

    2016-06-01

    We report infrared photodissociation spectra of [Bi(CO2)n]- (n=2-9) cluster anions. We determine the charge carrier geometry by comparing calculated vibrational frequencies based on density functional theory to the experimental spectra. The vibrational frequencies and the charge carrier geometry depend strongly on the solvation environment present in the cluster. We discuss the interaction of bismuth and CO_2 in the presence of an excess electron in the context of heterogeneous catalytic reduction of CO_2.

  7. Aqueous nitrite ion determination by selective reduction and gas phase nitric oxide chemiluminescence

    NASA Technical Reports Server (NTRS)

    Dunham, A. J.; Barkley, R. M.; Sievers, R. E.; Clarkson, T. W. (Principal Investigator)

    1995-01-01

    An improved method of flow injection analysis for aqueous nitrite ion exploits the sensitivity and selectivity of the nitric oxide (NO) chemilluminescence detector. Trace analysis of nitrite ion in a small sample (5-160 microL) is accomplished by conversion of nitrite ion to NO by aqueous iodide in acid. The resulting NO is transported to the gas phase through a semipermeable membrane and subsequently detected by monitoring the photoemission of the reaction between NO and ozone (O3). Chemiluminescence detection is selective for measurement of NO, and, since the detection occurs in the gas-phase, neither sample coloration nor turbidity interfere. The detection limit for a 100-microL sample is 0.04 ppb of nitrite ion. The precision at the 10 ppb level is 2% relative standard deviation, and 60-180 samples can be analyzed per hour. Samples of human saliva and food extracts were analyzed; the results from a standard colorimetric measurement are compared with those from the new chemiluminescence method in order to further validate the latter method. A high degree of selectivity is obtained due to the three discriminating steps in the process: (1) the nitrite ion to NO conversion conditions are virtually specific for nitrite ion, (2) only volatile products of the conversion will be swept to the gas phase (avoiding turbidity or color in spectrophotometric methods), and (3) the NO chemiluminescence detector selectively detects the emission from the NO + O3 reaction. The method is free of interferences, offers detection limits of low parts per billion of nitrite ion, and allows the analysis of up to 180 microL-sized samples per hour, with little sample preparation and no chromatographic separation. Much smaller samples can be analyzed by this method than in previously reported batch analysis methods, which typically require 5 mL or more of sample and often need chromatographic separations as well.

  8. Dynamic gas temperature measurements using a personal computer for data acquisition and reduction

    NASA Technical Reports Server (NTRS)

    Fralick, Gustave C.; Oberle, Lawrence G.; Greer, Lawrence C., III

    1993-01-01

    This report describes a dynamic gas temperature measurement system. It has frequency response to 1000 Hz, and can be used to measure temperatures in hot, high pressure, high velocity flows. A personal computer is used for collecting and processing data, which results in a much shorter wait for results than previously. The data collection process and the user interface are described in detail. The changes made in transporting the software from a mainframe to a personal computer are described in appendices, as is the overall theory of operation.

  9. Reduction of VOCs in flue gas from coal combustion by electron beam treatment

    NASA Astrophysics Data System (ADS)

    Chmielewski, A. G.; Ostapczuk, A.; Zimek, Z.; Licki, J.; Kubica, K.

    2002-03-01

    Coal combustion is one of the biggest sources of VOCs, which are emitted with various concentrations, polynuclear aromatic hydrocarbons (PAH) are known as the most dangerous, and among them, e.g. benzo(a)pyrene C 20H 12, benzo(g,h,I)perylene C 22H 12 or dibenzo(a,h)anthracene C 22H 14 are the most toxic according to EPA. Recent years have brought new regulations concerning PAH emission, and European countries have signed an international treaty, covering PAH emission. Tests at the pilot plant constructed at a coal-fired power station were performed with the purpose of estimating the influence of electron beam on VOCs present in flue gas, during SO 2 and NO x removal. The influence of electron beam on the global toxicity factor of flue gas has been analysed. In the presence of ammonia, the concentrations of some PAHs were lower than that without ammonia. The removal efficiencies have been ranged from 40% up to 98%.

  10. Reduction of VOC emissions by a membrane-based gas absorption process.

    PubMed

    Li, Rui; Xu, Jun; Wang, Lianjun; Li, Jiansheng; Sun, Xiuyun

    2009-01-01

    A membrane-based gas absorption (MGA) process was evaluated for the removal of volatile organic compounds (VOCs) based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine (NFM) as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison.

  11. Reduction of gaseous pollutant emissions from gas turbine combustors using hydrogen-enriched jet fuel

    NASA Technical Reports Server (NTRS)

    Clayton, R. M.

    1976-01-01

    Recent progress in an evaluation of the applicability of the hydrogen enrichment concept to achieve ultralow gaseous pollutant emission from gas turbine combustion systems is described. The target emission indexes for the program are 1.0 for oxides of nitrogen and carbon monoxide, and 0.5 for unburned hydrocarbons. The basic concept utilizes premixed molecular hydrogen, conventional jet fuel, and air to depress the lean flammability limit of the mixed fuel. This is shown to permit very lean combustion with its low NOx production while simulataneously providing an increased flame stability margin with which to maintain low CO and HC emission. Experimental emission characteristics and selected analytical results are presented for a cylindrical research combustor designed for operation with inlet-air state conditions typical for a 30:1 compression ratio, high bypass ratio, turbofan commercial engine.

  12. Nitrogen oxides reduction by carbonaceous materials and carbon dioxide separation using regenerative metal oxides from fossil fuel based flue gas

    NASA Astrophysics Data System (ADS)

    Gupta, Himanshu

    The ever-growing energy demands due to rising global population and continuing lifestyle improvements has placed indispensable emphasis on fossil fuels. Combustion of fossil fuels leads to the emission of harmful gaseous pollutants such as oxides of sulfur (SOx) and nitrogen (NOx), carbon dioxide (CO2), mercury, particulate matter, etc. Documented evidence has proved that this air pollution leads to adverse environmental health. This dissertation focuses on the development of technologies for the control of NOx and CO2 emissions. The first part of the thesis (Chapters 2--6) deals with the development of carbon based post combustion NOx reduction technology called CARBONOX process. High temperature combustion oxidizes both atmospheric nitrogen and organic nitrogen in coal to nitric oxide (NO). The reaction rate between graphite and NO is slow and requires high temperature (>900°C). The presence of metallic species in coal char catalyzes the reaction. The reaction temperature is lowered in the presence of oxygen to about 600--850°C. Chemical impregnation, specifically sodium compounds, further lowers the reaction temperature to 350--600°C. Activated high sodium lignite char (HSLC) provided the best performance for NO reduction. The requirement of char for NOx reduction is about 8--12 g carbon/g NO reduced in the presence of 2% oxygen in the inlet gas. The second part of this dissertation (chapter 7--8) focuses on the development of a reaction-based process for the separation of CO2 from combustion flue gas. Certain metal oxides react with CO2 forming metal carbonates under flue gas conditions. They can be calcined separately to yield CO2. Calcium oxide (CaO) has been identified as a viable metal oxide for the carbonation-calcination reaction (CCR) scheme. CaO synthesized from naturally occurring precursors (limestone and dolomite) attained 45--55% of their stoichiometric conversion due to the susceptibility of their microporous structure. High surface area

  13. Preparation of cobalt nanoparticles by hydrogen reduction of cobalt chloride in the gas phase

    SciTech Connect

    Jang, Hee Dong; Hwang, Dae Won; Kim, Dong Pyo; Kim, Heon Chang; Lee, Byung Yoon; Jeong, In Bum

    2004-01-03

    Cobalt nanoparticles were produced by the hydrogen reduction of cobalt chloride vapor in a multistage tubular aerosol flow reactor. Reaction zone temperature, preheating temperature, mole fractions of CoCl{sub 2} and H{sub 2}, and residence time were considered as key process variables for the control of particle size and size distribution. Ranging from 50 to 78 nm in average diameter, cobalt nanoparticles with narrow size distributions were synthesized throughout our experiments. All of the considered process variables affected the particle size and size distribution in the synthesis of cobalt nanoparticles. As the reaction zone temperature and the CoCl{sub 2} mole fraction increased, the average particle diameter increased. But the average particle diameter decreased as the residence time of reactants increased.

  14. Wear reduction in ceramic bearings by surface generated pyrolytic carbon continuously replenished by ethylene gas

    NASA Technical Reports Server (NTRS)

    Lauer, J. L.; Davis, L. C.

    1993-01-01

    Sliding tests with a pin-on-disc tribometer and both sliding and rolling tests with a modified four-ball tester at bulk temperatures of about 500 C and contact pressures of about 2.2 GPa have demonstrated up to 80% reductions of friction and wear with silicon nitride surfaces when a stream of ethylene is directed into the conjunction region. The effects are even more pronounced when the ethylene is prenucleated by a flow over a coil of nichrome wire electrically heated to about 800 C and located about 30 cm upstream of the exit nozzle. Steel and Ni-plated steel are lubricated by this method even more efficiently at lower temperatures.

  15. Prediction and Mitigation of the Effects of Catastrophic Fire on Water Supplies: Science for Risk Reduction and Planning for Future Scenarios

    NASA Astrophysics Data System (ADS)

    Martin, D. A.; Tindall, J.

    2008-12-01

    geology. Ash affects the hydraulic properties and behavior of soils in burned watersheds while it still mantles the hillslopes, but it is easily delivered to water bodies by rain and wind as a flush of material that affects water chemistry and properties like turbidity and temperature. A third thrust is to identify watersheds that are critical to the function of municipal water supplies and infrastructure to determine their vulnerability to fire and post-fire effects. This information can be used to prioritize areas for fuel treatments or land management practices to minimize the probability of high severity fire and hence the effects of post-fire runoff. Scientific studies are providing crucial information about such topics as changes in soil erodibility, infiltration and runoff after fire, and the effects of vegetation recovery. Even in watersheds where land management actions are limited by topography or land use designation, such as wilderness areas, knowledge of the potential response of burned areas allows water providers to develop rapid-response and long-term plans based on scientific data and tools. Some climate change models are predicting hotter, drier temperatures in certain areas of the United States and a higher probability of larger, more severe wildfires. These predictions have a direct bearing on the potential risk of impairment of water supplies by post-fire runoff and erosion. In an era when water availability and quality are of utmost importance, careful scientific studies focused on the effects of wildland fire on water supplies will continue to inform public policy and decision making on topics of vulnerability and risk reduction.

  16. Sustainability and Energy Development: Influences of Greenhouse Gas Emissions Reduction Options on Water Use in Energy Production

    SciTech Connect

    D. Craig Cooper; Gerald Sehlke

    2012-01-01

    Climate change mitigation strategies cannot be evaluated solely in terms of energy cost and greenhouse gas (GHG) mitigation potential. Maintaining GHGs at a 'safe' level will require fundamental change in the way we approach energy production, and a number of environmental, economic, and societal factors will come into play. Water is an essential component of energy production, and water resource constraints (e.g., insufficient supplies and competing ecological and anthropogenic needs) will limit our options for producing energy and for reducing GHG emissions. This study evaluates these potential constraints from a global perspective by revisiting the 'climate wedges' proposal of Pacala and Sokolow [1], and evaluating the potential water impacts of the 'wedges' associated with energy production. Results indicate that there is a range of water impacts, with some options reducing water demand while others increase water demand. Mitigation options that improve energy conversion and end-use efficiency have the greatest potential for reducing water resources impacts. These options provide 'win-win-win' scenarios for reducing GHG emissions, lowering energy costs and reducing water demand. Thet may merit higher priority than alternative options that emphasize deploying new low-carbon energy facilities or modifying existing facilities with energy intensive GHG mitigation technologies to reduce GHG emissions. While the latter can reduce GHG emissions, they will typically increase energy costs and water impacts.

  17. Public Review Draft: A Method for Assessing Carbon Stocks, Carbon Sequestration, and Greenhouse-Gas Fluxes in Ecosystems of the United States Under Present Conditions and Future Scenarios

    USGS Publications Warehouse

    Bergamaschi, Brian A.; Bernknopf, Richard; Clow, David; Dye, Dennis; Faulkner, Stephen; Forney, William; Gleason, Robert; Hawbaker, Todd; Liu, Jinxun; Liu, Shu-Guang; Prisley, Stephen; Reed, Bradley; Reeves, Matthew; Rollins, Matthew; Sleeter, Benjamin; Sohl, Terry; Stackpoole, Sarah; Stehman, Stephen; Striegl, Robert G.; Wein, Anne; Zhu, Zhi-Liang; Zhu, Zhi-Liang

    2010-01-01

    The Energy Independence and Security Act of 2007 (EISA), Section 712, authorizes the U.S. Department of the Interior to develop a methodology and conduct an assessment of the Nation's ecosystems focusing on carbon stocks, carbon sequestration, and emissions of three greenhouse gases (GHGs): carbon dioxide, methane, and nitrous oxide. The major requirements include (1) an assessment of all ecosystems (terrestrial systems, such as forests, croplands, wetlands, shrub and grasslands; and aquatic ecosystems, such as rivers, lakes, and estuaries), (2) an estimation of annual potential capacities of ecosystems to increase carbon sequestration and reduce net GHG emissions in the context of mitigation strategies (including management and restoration activities), and (3) an evaluation of the effects of controlling processes, such as climate change, land use and land cover, and wildlfires. The purpose of this draft methodology for public review is to propose a technical plan to conduct the assessment. Within the methodology, the concepts of ecosystems, carbon pools, and GHG fluxes used for the assessment follow conventional definitions in use by major national and international assessment or inventory efforts. In order to estimate current ecosystem carbon stocks and GHG fluxes and to understand the potential capacity and effects of mitigation strategies, the method will use two time periods for the assessment: 2001 through 2010, which establishes a current ecosystem GHG baseline and will be used to validate the models; and 2011 through 2050, which will be used to assess future potential conditions based on a set of projected scenarios. The scenario framework is constructed using storylines of the Intergovernmental Panel on Climate Change (IPCC) Special Report Emission Scenarios (SRES), along with initial reference land-use and land-cover (LULC) and land-management scenarios. An additional three LULC and land-management mitigation scenarios will be constructed for each

  18. Combustion efficiency: Greenhouse gas emission reductions from the power generation sector

    SciTech Connect

    Kane, R.; South, D.W.; Fish, A.L.

    1993-12-31

    Concern for the possibility of an enhanced greenhouse effect and global climate change (GCC) has often been associated with energy use in general, and fossil fuel combustion in particular, because of associated emissions of CO{sub 2} and other greenhouse gases (GHG). Therefore, energy policies play a significant role in determining greenhouse gas emissions. The generation of electricity and power from more efficient fossil energy technologies provides an opportunity to significantly lower GHG emissions, together with other pollutants. The U.S. government oversees a broad-based program to facilitate the development, demonstration, and deployment of these technologies. Advanced fossil technologies offer other benefits as well, in that they permit continued use of widely available fuels such as coal. An international perspective is critical for assessing the role of these fuels, since countries differ in terms of their ability to maximize these benefits. Often, new technologies are considered the domain of industrialized countries. Yet more efficient technologies may have their greatest potential - to concurrently permit the utilization of indigenous fuels and to lower global GHG emissions in developing countries, especially those in the Asia-Pacific region.

  19. Greenhouse Gas Reductions From Rice Cultivation And The California Cap-and-Trade Market

    NASA Astrophysics Data System (ADS)

    Parkhurst, R.; Salas, W.; Nichols, L.

    2014-12-01

    The California Air Resources Board is developing a compliance offset protocol for rice cultivation practices. This protocol contains three different activities that growers can take to reduce the generation of methane associated with rice cultivation - dry seeding, early drainage, and alternate wetting and drying of fields. All of these practices have been developed using the latest science and have been shown to reduce methane generation without impacting yield. Methane is the second largest anthropogenic source of greenhouse gas (GHG) emissions, accounting for 9% of all U.S. GHG emissions from human activities. Methane is also important because it is more than 20 times more potent a GHG than carbon dioxide. The rice cultivation protocol is important because it will be the first crop-based protocol considered as a part of California's cap-and-trade program. This session will discuss the latest developments with the protocol from stakeholders involved in the creation of the protocol. We invite you to hear lessons learnt from this experience in order to apply similar approaches to other regions/countries and crops.

  20. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage

    PubMed Central

    Mehboob, Farrakh; van Gelder, Antonie H.; Rijpstra, W. Irene C.; Damsté, Jaap S. Sinninghe; Stams, Alfons J. M.

    2010-01-01

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5–0.8 μm in diameter, and 2–8 μm in length, growing as single cells or in pairs. The cells grew optimally at 37°C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H2/CO2 to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO2. The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts. PMID:20680263

  1. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

    PubMed

    Balk, Melike; Mehboob, Farrakh; van Gelder, Antonie H; Rijpstra, W Irene C; Damsté, Jaap S Sinninghe; Stams, Alfons J M

    2010-09-01

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

  2. Combustion generated noise in gas turbine combustors. [engine noise/noise reduction

    NASA Technical Reports Server (NTRS)

    Strahle, W. C.; Shivashankara, B. N.

    1974-01-01

    Experiments were conducted to determine the noise power and spectra emitted from a gas turbine combustor can exhausting to the atmosphere. Limited hot wire measurements were made of the cold flow turbulence level and spectra within the can. The fuels used were JP-4, acetone and methyl alcohol burning with air at atmospheric pressure. The experimental results show that for a fixed fuel the noise output is dominated by the airflow rate and not the fuel/air ratio. The spectra are dominated by the spectra of the cold flow turbulence spectra which were invariant with airflow rate in the experiments. The effect of fuel type on the noise power output was primarily through the heat of combustion and not the reactivity. A theory of combustion noise based upon the flame radiating to open surroundings is able to reasonably explain the observed results. A thermoacoustic efficiency for noise radiation as high as .00003 was observed in this program for JP-4 fuel. Scaling rules are presented for installed configurations.

  3. Emission reduction potential of using gas-to-liquid and dimethyl ether fuels on a turbocharged diesel engine.

    PubMed

    Xinling, Li; Zhen, Huang

    2009-03-15

    A study of engine performance characteristics and both of regulated (CO, HC, NO(x), and smoke) and unregulated (ultrafine particle number, mass concentrations and size distribution) emissions for a turbocharged diesel engine fueled with conventional diesel, gas-to-liquid (GTL) and dimethyl ether (DME) fuels respectively at different engine loads and speeds have been carried out. The results indicated that fuel components significantly affected the engine performance and regulated/unregulated emissions. GTL exhibited almost the same power and torque output as diesel, while improved fuel economy. GTL significantly reduced regulated emissions with average reductions of 21.2% in CO, 15.7% in HC, 15.6% in NO(x) and 22.1% in smoke in comparison to diesel, as well as average reductions in unregulated emissions of total ultrafine particle number (N(tot)) and mass (M(tot)) emissions by 85.3% and 43.9%. DME can significantly increase torque and power, compared with the original diesel engine, as well as significantly reduced regulated emissions of 40.1% in HC, 48.2% in NO(x) and smoke free throughout all the engine conditions. However, N(tot) for DME is close to that for diesel. The reason is that the accumulation mode particle number emissions for DME are very low due to the characteristics of oxygen content and no C-C bond, which promotes the processes of nucleation and condensation of the semi-volatile compounds in the exhaust gas, as a result, a lot of nucleation mode particles produce.

  4. Study of Eu{sup 3+} → Eu{sup 2+} reduction in BaAl{sub 2}O{sub 4}:Eu prepared in different gas atmospheres

    SciTech Connect

    Rezende, Marcos V. dos S.; Valerio, Mário E.G.; Jackson, Robert A.

    2015-01-15

    Highlights: • The effect of different gas atmospheres on the Eu reduction process was studied. • The Eu reduction was monitored analyzing XANES region at the Eu L{sub III}-edge. • Hydrogen reducing agent are the most appropriate gas for Eu{sup 2+} stabilization. • Only a part of the Eu ions can be stabilized in the divalent state. • A model of Eu reduction process is proposed. - Abstract: The effect of different gas atmospheres such as H{sub 2}(g), synthetic air, carbon monoxide (CO) and nitrogen (N{sub 2}) on the Eu{sup 3+} → Eu{sup 2+} reduction process during the synthesis of Eu-doped BaAl{sub 2}O{sub 4} was studied using synchrotron radiation. The Eu{sup 3+} → Eu{sup 2+} reduction was monitored analyzing XANES region when the sample are excited at the Eu L{sub III}-edge. The results show that the hydrogen reducing agent are the most appropriate gas for Eu{sup 2+} stabilization in BaAl{sub 2}O{sub 4} and that only a part of the Eu ions can be stabilized in the divalent state. A model of Eu reduction process, based on the incorporation of charge compensation defects, is proposed.

  5. Global sources of non-CO2 greenhouse gas emissions: regional trends, uncertainties and options for emission reductions

    NASA Astrophysics Data System (ADS)

    Olivier, J. G.; van Aardenne, J. A.; Peters, J. A.

    2005-05-01

    An overview will be presented of sources and trends of global emissions of direct non-CO2 greenhouse gases CH4, N2O and the fluorinated gases HFCs, PFCs and SF6, which are addressed in the Kyoto protocol. Special attention will be given to regional source trends, estimated uncertainties and most recent global emission trends. In addition, the most significant options for emission reductions will be discussed in view of medium term emission scenarios that were meant to illustrate future trends without the effects climate policy. For estimating the recent global emission trends a special approach was used to compile fast annual updates of the EDGAR global emission inventories, based on the more detailed previous version. We present an overview of the approaches used for this `Fast Track' for the different source sectors. Results are presented for 1995-2002 for various anthropogenic sources at regional scales including an estimate of the accuracies achieved. A similar overview will be provided for the emissions of the ozone precursors NOx, CO and NMVOC and of black carbon. Tropospheric ozone and black carbon are both greenhouse gases, which are not considered in the Kyoto protocol, but in industrialised countries the emissions that cause them are often part of environmental policy on local and regional air quality.

  6. Quantifying the fuel use and greenhouse gas reduction potential of electric and hybrid vehicles.

    SciTech Connect

    Singh, M.; Wang, M.; Hazard, N.; Lewis, G.; Energy Systems; Northeast Sustainable Energy Association; Univ. of Michigan

    2000-01-01

    Since 1989, the Northeast Sustainable Energy Association (NESEA) has organized the American Tour de Sol in which a wide variety of participants operate electric vehicles (EVs) and hybrid electric vehicles (HEVs) for several hundred miles under various roadway conditions (e.g., city center and highway). The event offers a unique opportunity to collect on-the-road energy efficiency data for these EVs and HEVs as well as comparable gasoline-fueled conventional vehicles (CVs) that are driven under the same conditions. NESEA and Argonne National Laboratory (ANL) collaborated on collecting and analyzing vehicle efficiency data during the 1998 and 1999 NESEA American Tour de Sols. Using a transportation fuel-cycle model developed at ANL with data collected on vehicle fuel economy from the two events as well as electric generation mix data from the utilities that provided the electricity to charge the EVs on the two Tours, we estimated full fuel-cycle energy use and GHG emissions of EVs and CVs. This paper presents the data, methodology, and results of this study, including the full fuel-cycle energy use and GHG emission reduction potential of the EVs operating on the Tour.

  7. Tuning graphene for energy and environmental applications: Oxygen reduction reaction and greenhouse gas mitigation

    NASA Astrophysics Data System (ADS)

    Haque, Enamul; Sarkar, Shuranjan; Hassan, Mahbub; Hossain, Md. Shahriar; Minett, Andrew I.; Dou, Shi Xue; Gomes, Vincent G.

    2016-10-01

    Porous nitrogen-doped graphene samples were synthesized and tuned via pyrolysis of solid nitrogen precursor dimethyl-aminoterephthalate with graphene oxide as template. Our investigations show that the extent of thermal treatment, total concentration of nitrogen and the nature of nitrogen moieties play important roles in enhancing oxygen reduction reaction (ORR) and CO2 uptake. N-doped graphene synthesized at 650 °C (NG-650) with specific BET surface area of 278 m2/g, exhibits enhanced CO2 sorption capacity of 4.43 mmol/g (at 298 K, 1 bar) with exceptional selectivity (CO2:N2 = 42) and cyclic regeneration stability. In contrast, nitrogen-doped graphene synthesized at 750 °C (NG-750) demonstrated excellent catalytic activity for ORR via favourable 4e- transfer, performance stability with tests conducted up to 5000 cycles, and is unaffected by methanol cross-over effect. Thus, NG-750 shows potential to replace metal-based electrodes for fuel cell application. The comparative results for ORR with non-doped and nitrogen-doped graphene electrodes showed that graphitic nitrogen sites play vital role in enhancing catalytic activity.

  8. CO2 Reduction Effect of the Utilization of Waste Heat and Solar Heat in City Gas System

    NASA Astrophysics Data System (ADS)

    Okamura, Tomohito; Matsuhashi, Ryuji; Yoshida, Yoshikuni; Hasegawa, Hideo; Ishitani, Hisashi

    We evaluate total energy consumption and CO2 emissions in the phase of the city gas utilization system from obtaining raw materials to consuming the product. First, we develop a simulation model which calculates CO2 emissions for monthly and hourly demands of electricity, heats for air conditioning and hot-water in a typical hospital. Under the given standard capacity and operating time of CGS, energy consumption in the equipments is calculated in detail considering the partial load efficiency and the control by the temperature of exhaust heat. Then, we explored the optimal size and operation of city gas system that minimizes the life cycle CO2 emissions or total cost. The cost-effectiveness is compared between conventional co-generation, solar heat system, and hybrid co-generation utilizing solar heat. We formulate a problem of mixed integer programming that includes integral parameters that express the state of system devices such as on/off of switches. As a result of optimization, the hybrid co-generation can reduce annual CO2 emissions by forty-three percent compared with the system without co-generation. Sensitivity for the scale of CGS on CO2 reduction and cost is also analyzed.

  9. The conversion of grassland to acacia forest as an effective option for net reduction in greenhouse gas emissions.

    PubMed

    de Godoi, Stefânia Guedes; Neufeld, Ângela Denise Hubert; Ibarr, Mariana Alves; Ferreto, Décio Oscar Cardoso; Bayer, Cimélio; Lorentz, Leandro Homrich; Vieira, Frederico Costa Beber

    2016-03-15

    This study aimed to evaluate the effect of forestation with leguminous Acacia mearnsii De Wild in native grasslands on the soil greenhouse (GHG) fluxes and their main driving factors. The experiment was conducted in the Brazilian Pampa over the period of one year in a six-year-old Acacia plantation, evaluating four treatments: Acacia (AM), Acacia with litter periodically removed (A-l), Acacia after harvest (AH) and native grassland (NG) (reference treatment). Air samples were obtained by the static chamber method, and gas concentrations were evaluated by gas chromatography. Soil and climate factors were monitored. The accumulated fluxes of methane (CH4) and nitrous oxide (N2O) were statistically similar between the soils in the AM and NG treatments, which tended to oxidize CH4 (-1445 and -1752 g C-CH4 ha(-1) yr(-1), respectively) and had low emission of N2O (242 and 316 g N-N2O ha(-1) yr(-1)), most likely influenced by the low water-filled pore space and the low content of mineral N in the soil. However, the soil in the AH treatment presented higher emissions of both gases, totaling 1889 g C-CH4 ha(-1) yr(-1) and 1250 g N-N2O ha(-1) yr(-1). Afforestation neither significantly affected the total organic C stocks nor their lability, keeping the C management index for the forested area similar to that in the NG treatment. The conversion from grassland to Acacia forest represents an effective option for mitigating the net reduction in greenhouse gas emissions, which is basically determined by C accumulation in biomass and wood products.

  10. Reduction of regulated and unregulated exhaust gas emission components from diesel engines running with rapeseedmethylester using oxidation catalyst technologies

    SciTech Connect

    May, H.; Huettenberger, P.

    1996-12-31

    Up to now all engine research was based on engines, which are adapted to Diesel fuel but not to vegetableoilmethylester (VME). Caused by the special climate conditions in Europe rapeseed and sunflowers, in the US soya-beans and in the tropical countries palm trees are the favorable plants for vegetable oil production. The physical and chemical properties of Diesel fuel and VME are quite different. Therefore an engine adaption and redesign to VME is a suitable way of further reduction of noxious and climate-influencing emissions. To prove the effectiveness of the emission reduction the European test-cycle ECE/EUDC, the US-FTP 75 test for passenger cars and the European 13-stage-test-cycle for heavy duty-truck-engines has been used with and without an oxidation catalyst in each case. The results of the exhaust gas measurement both concerning regulated and unregulated components are shown. A comparison between engines fueled with fossil diesel fuel and rapeseedmethylester (RME) is given.

  11. Selective autocatalytic reduction of NO from sintering flue gas by the hot sintered ore in the presence of NH3.

    PubMed

    Chen, Wangsheng; Luo, Jing; Qin, Linbo; Han, Jun

    2015-12-01

    In this paper, the selective autocatalytic reduction of NO by NH3 combined with multi-metal oxides in the hot sintered ore was studied, and the catalytic activity of the hot sintered ore was investigated as a function of temperature, NH3/NO ratio, O2 content, H2O and SO2. The experimental results indicated that the hot sintered ore, when combined with NH3, had a maximum denitration efficiency of 37.67% at 450 °C, 3000 h(-1) gas hourly space velocity (GHSV) and a NH3/NO ratio of 0.4/1. Additionally, it was found that O2 played an important role in removing NOx. However, high O2 content had a negative effect on NO reduction. H2O was found to promote the denitration efficiency in the absence of SO2, while SO2 inhibited the catalytic activity of the sintered ore. In the presence of H2O and SO2, the catalytic activity of the sintered ore was dramatically suppressed.

  12. A rotating two-phase gas/liquid flow for pressure reduction in underwater plasma arc welding

    SciTech Connect

    Steinkamp, H.; Creutz, M.; Mewes, D.; Bartzsch, J.

    1994-12-31

    Plasma arc welding processes are used in off-shore industry for the construction and maintenance in the wet surrounding of underwater structures and pipelines. In greater water depth the density of the plasma gas increase because of the greater hydrostatic pressure. This causes an increase of the conductive heat losses to the wet surrounding. To keep up the energy flux to the workpiece a pressure reduction is favorable against the surrounding. To keep up the energy flux to the workpiece a pressure reduction is favorable against the surrounding. The plasma arc has to burn in a locally dry area. This requirement can be fulfilled by a rotating disc placed above the workpiece. In the gap between the lower end of the cylinder and the workpiece a rotating two-phase flow is maintained. The flow around the rotating disc is experimentally investigated. The rotating disc is placed above the surface of the workpiece which is simulated by a flat plate. Water is forced out of the cylinder due to centrifugal forces set up by the rotating disc and flat plate. The velocity distribution in the flow is measured by Laser-Doppler-Anemometry. The phase distribution in the two-phase flow in the gap is measured by local electrical probes. The static pressure in the gaseous atmosphere is reduced in comparison to the hydrostatic pressure of the surrounding water. The pressure reduction is given by the void fraction, the phase distribution and the volume flow rates of both phases in the gap as well as by the speed of revolution and the design of the disc and the work surface. Apart from the investigations on the fluid dynamics, the method to reduce the pressure was technically proved. Experiments were carried out under water with a plasma MIG welder.

  13. Evaluation of Efficiency Activities in the Industrial Sector Undertaken in Response to Greenhouse Gas Emission Reduction Targets

    SciTech Connect

    Price, Lynn; de la Rue du Can, Stephane; Lu, Hongyou; Horvath, Arpad

    2010-05-21

    The 2006 California Global Warming Solutions Act calls for reducing greenhouse gas (GHG) emissions to 1990 levels by 2020. Meeting this target will require action from all sectors of the California economy, including industry. The industrial sector consumes 25% of the energy used and emits 28% of the carbon dioxide (CO{sub 2}) produced in the state. Many countries around the world have national-level GHG reduction or energy-efficiency targets, and comprehensive programs focused on implementation of energy efficiency and GHG emissions mitigation measures in the industrial sector are essential for achieving their goals. A combination of targets and industry-focused supporting programs has led to significant investments in energy efficiency as well as reductions in GHG emissions within the industrial sectors in these countries. This project has identified program and policies that have effectively targeted the industrial sector in other countries to achieve real energy and CO{sub 2} savings. Programs in Ireland, France, The Netherlands, Denmark, and the UK were chosen for detailed review. Based on the international experience documented in this report, it is recommended that companies in California's industrial sector be engaged in a program to provide them with support to meet the requirements of AB32, The Global Warming Solution Act. As shown in this review, structured programs that engage industry, require members to evaluate their potential efficiency measures, plan how to meet efficiency or emissions reduction goals, and provide support in achieving the goals, can be quite effective at assisting companies to achieve energy efficiency levels beyond those that can be expected to be achieved autonomously.

  14. A method for assessing carbon stocks, carbon sequestration, and greenhouse-gas fluxes in ecosystems of the United States under present conditions and future scenarios

    USGS Publications Warehouse

    Bergamaschi, Brian A.; Bernknopf, Richard; Clow, David; Dye, Dennis; Faulkner, Stephen; Forney, William; Gleason, Robert; Hawbaker, Todd; Liu, Jinxun; Liu, Shu-Guang; Prisley, Stephen; Reed, Bradley; Reeves, Matthew; Rollins, Matthew; Sleeter, Benjamin; Sohl, Terry; Stackpoole, Sarah; Stehman, Stephen; Striegl, Robert; Wein, Anne; Zhu, Zhi-Liang; Zhu, Zhi-Liang

    2010-01-01

    he Energy Independence and Security Act of 2007 (EISA), Section 712, mandates the U.S. Department of the Interior to develop a methodology and conduct an assessment of the Nation’s ecosystems, focusing on carbon stocks, carbon sequestration, and emissions of three greenhouse gases (GHGs): carbon dioxide, methane, and nitrous oxide. The major requirements include (1) an assessment of all ecosystems (terrestrial systems, such as forests, croplands, wetlands, grasslands/shrublands; and aquatic ecosystems, such as rivers, lakes, and estuaries); (2) an estimate of the annual potential capacities of ecosystems to increase carbon sequestration and reduce net GHG emissions in the context of mitigation strategies (including management and restoration activities); and (3) an evaluation of the effects of controlling processes, such as climate change, land-use and land-cover change, and disturbances such as wildfires.The concepts of ecosystems, carbon pools, and GHG fluxes follow conventional definitions in use by major national and international assessment or inventory efforts. In order to estimate current ecosystem carbon stocks and GHG fluxes and to understand the potential capacity and effects of mitigation strategies, the method will use two time periods for the assessment: 2001 through 2010, which establishes a current ecosystem carbon and GHG baseline and will be used to validate the models; and 2011 through 2050, which will be used to assess potential capacities based on a set of scenarios. The scenario framework will be constructed using storylines of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES), along with both reference and enhanced land-use and land-cover (LULC) and land-management parameters. Additional LULC and land-management mitigation scenarios will be constructed for each storyline to increase carbon sequestration and reduce GHG fluxes in ecosystems. Input from regional experts and stakeholders will be

  15. The Use of Cryogenically Cooled 5A Molecular Sieves for Large Volume Reduction of Tritiated Hydrogen Gas

    SciTech Connect

    Antoniazzi, A.B.; Bartoszek, F.E.; Sherlock, A.M.

    2006-07-01

    A commercial hydrogen isotope separation system based on gas chromatography (AGC-ISS) has been built. The system operates in two modes: stripping and volume reduction. The purpose of the stripping mode is to reduce a large volume of tritiated hydrogen gas to a small volume of tritium rich hydrogen gas. The results here illustrate the effectiveness of the AGC-ISS in the stripping and volume reduction phases. Column readiness for hydrogen isotope separation is confirmed by room temperature air separation tests. Production runs were initially carried out using natural levels of deuterium (110-160 ppm) in high purity hydrogen. After completion of the deuterium/hydrogen runs the system began operations with tritiated hydrogen. The paper presents details of the AGC-ISS design and results of tritium tests. The heart of the AGC-ISS consists of two packed columns (9 m long, 3.8 cm OD) containing 5A molecular sieve material of 40/60 mesh size. Each column has 5 individually controlled heaters along the length of the column and is coiled around an inverted inner dewar. The coiled column and inner dewar are both contained within an outer dewar. In this arrangement liquid nitrogen, used to cryogenically cool the columns, flows into and out off the annular space defined by the two dewars, allowing for alternate heating and cooling cycles. Tritiated hydrogen feed is injected in batch quantities. The batch size is variable with the maximum quantity restricted by the tritium concentration in the exhausted hydrogen. The stripping operations can be carried out in full automated mode or in full manual mode. The average cycle time between injections is about 75 minutes. To date, the maximum throughput achieved is 10.5 m{sup 3}/day. A total of 37.8 m{sup 3} of tritiated hydrogen has been processed during commissioning. The system has demonstrated that venting of >99.95% of the feed gas is possible while retaining 99.98% of the tritium. At a maximum tritium concentration of {approx}7 GBq

  16. Nitrous Oxides Ozone Destructiveness Under Different Climate Scenarios

    NASA Technical Reports Server (NTRS)

    Kanter, David R.; McDermid, Sonali P.

    2016-01-01

    Nitrous oxide (N2O) is an important greenhouse gas and ozone depleting substance as well as a key component of the nitrogen cascade. While emissions scenarios indicating the range of N2O's potential future contributions to radiative forcing are widely available, the impact of these emissions scenarios on future stratospheric ozone depletion is less clear. This is because N2O's ozone destructiveness is partially dependent on tropospheric warming, which affects ozone depletion rates in the stratosphere. Consequently, in order to understand the possible range of stratospheric ozone depletion that N2O could cause over the 21st century, it is important to decouple the greenhouse gas emissions scenarios and compare different emissions trajectories for individual substances (e.g. business-as-usual carbon dioxide (CO2) emissions versus low emissions of N2O). This study is the first to follow such an approach, running a series of experiments using the NASA Goddard Institute for Space Sciences ModelE2 atmospheric sub-model. We anticipate our results to show that stratospheric ozone depletion will be highest in a scenario where CO2 emissions reductions are prioritized over N2O reductions, as this would constrain ozone recovery while doing little to limit stratospheric NOx levels (the breakdown product of N2O that destroys stratospheric ozone). This could not only delay the recovery of the stratospheric ozone layer, but might also prevent a return to pre-1980 global average ozone concentrations, a key goal of the international ozone regime. Accordingly, we think this will highlight the importance of reducing emissions of all major greenhouse gas emissions, including N2O, and not just a singular policy focus on CO2.

  17. Anaerobic Co-digestion for Enhanced Renewable Energy and Green House Gas Emission Reduction

    SciTech Connect

    Navaratnam, Navaneethan; Zitomer, Daniel

    2012-05-01

    The need to develop renewable energy is important for replacing fossil fuel, which is limited in quantity and also tends to increase in price over time. The addition of high strength organic wastes in municipal anaerobic digesters is growing and tends to increase renewable energy production. In addition, conversion of wastes to energy significantly reduces uncontrolled greenhouse gas emissions. Co-digestion of municipal sludge with any combination of wastes can result in synergistic, antagonistic or neutral outcomes. The objectives of this study were to identify potential co-digestates, determine synergistic, antagonistic and neutral effects, determine economic benefits, quantify performance of bench scale co-digesters, identify influence of co-digestion on microbial communities and implement appropriate co-digestion, if warranted, after full-scale testing. A market study was used to identify promising co-digestates. Most promising wastes were determined by biochemical methane potential (BMP) and other testing followed by a simple economic analysis. Performance was investigated using bench-scale digesters receiving synthetic primary sludge with and without co-digestates. Denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction (qPCR) analyses were performed on the gene encoding the α subunit of methyl coenzyme M reductase (mcrA) to compare methanogen communities among the digesters. One significant band contributing to the greatest difference in banding patterns was excised, cloned, amplified and sequenced. Full- scale co-digestion was conducted using the most promising co-digestate at South Shore Wastewater Reclamation Facility (Oak Creek, WI). Over 80 wastes were identified from 54 facilities within 160 km of an existing municipal digester. A simple economic comparison identified the greatest benefits for seven co-digestates. Methane production rates of two co- digester systems increased by 105% and 66% in comparison to a control

  18. Upgraded biogas from municipal solid waste for natural gas substitution and CO2 reduction--a case study of Austria, Italy, and Spain.

    PubMed

    Starr, Katherine; Villalba, Gara; Gabarrell, Xavier

    2015-04-01

    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 CO2 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.

  19. Physical And Technical Energy Problems. Factors of Greenhouse Gas Emissions Reduction in the Road Transport of Latvia / Siltumnīcefekta Gāzu Emisiju Samazināšanas Faktori Autotransportā Latvijā

    NASA Astrophysics Data System (ADS)

    Grackova, L.; Klavs, G.

    2013-02-01

    The admissible scenarios are considered as related to reduction in the greenhouse gas emissions from the road transport in Latvia by 2020. All of the scenarios are analysed, and the proofs are presented for the possibility to reduce such emissions as well as the energy consumption through a more extensive use of efficient cars and biofuel. Izmantojot scenāriju modelēšanas pieeju un COPERT IV modeli, novērtēts siltumnīcefekta gāzu emisiju samazināšanas potenciāls autotransportā Latvijā līdz 2020. gadam. Modelēšanas rezultāti un analīze ļauj secināt, ka neskatoties uz sagaidāmo automašīnu skaita palielināšanos, jaunu energoefektīvu automašīnu ar augstākiem izmešu standartiem izmantošana un biodegvielas piemaisījuma palielināšana autotransportā izmantojamā degvielā ļauj ierobežot siltumnīcefekta gāzu emisiju pieaugumu.

  20. Next Generation Safeguards Initiative: Analysis of Probability of Detection of Plausible Diversion Scenarios at Gas Centrifuge Enrichment Plants Using Advanced Safeguards

    SciTech Connect

    Hase, Kevin R.; Hawkins Erpenbeck, Heather; Boyer, Brian D.

    2012-07-10

    Over the last decade, efforts by the safeguards community, including inspectorates, governments, operators and owners of centrifuge facilities, have given rise to new possibilities for safeguards approaches in enrichment plants. Many of these efforts have involved development of new instrumentation to measure uranium mass and uranium-235 enrichment and inspection schemes using unannounced and random site inspections. We have chosen select diversion scenarios and put together a reasonable system of safeguards equipment and safeguards approaches and analyzed the effectiveness and efficiency of the proposed safeguards approach by predicting the probability of detection of diversion in the chosen safeguards approaches. We analyzed the effect of redundancy in instrumentation, cross verification of operator instrumentation by inspector instrumentation, and the effects of failures or anomalous readings on verification data. Armed with these esults we were able to quantify the technical cost benefit of the addition of certain instrument suites and show the promise of these new systems.

  1. Characterization of the synthesis of N,N-dimethyltryptamine by reductive amination using gas chromatography ion trap mass spectrometry.

    PubMed

    Brandt, Simon D; Moore, Sharon A; Freeman, Sally; Kanu, Abu B

    2010-07-01

    The present study established an impurity profile of a synthetic route to the hallucinogenic N,N-dimethyltryptamine (DMT). The synthesis was carried out under reductive amination conditions between tryptamine and aqueous formaldehyde in the presence of acetic acid followed by reduction with sodium cyanoborohydride. Analytical characterization of this synthetic route was carried out by gas chromatography ion trap mass spectrometry using electron- and chemical-ionization modes. Methanol was employed as a liquid CI reagent and the impact of stoichiometric modifications on side-products formation was also investigated. Tryptamine 1, DMT 2, 2-methyltetrahydro-β-carboline (2-Me-THBC, 3), N-methyl-N-cyanomethyltryptamine (MCMT, 4), N-methyltryptamine (NMT, 5), 2-cyanomethyl-tetrahydro-β-carboline (2-CM-THBC, 6) and tetrahydro-β-carboline (THBC, 7) have been detected under a variety of conditions. Replacement of formaldehyde solution with paraformaldehyde resulted in incomplete conversion of the starting material whereas a similar replacement of sodium cyanoborohydride with sodium borohydride almost exclusively produced THBC instead of the expected DMT. Compounds 1 to 7 were quantified and the limits of detection were 28.4, 87.7, 21.5, 23.4, 41.1, 36.6, and 34.9 ng mL(-1), respectively. The limits of quantification for compounds 1 to 7 were 32.4, 88.3, 25.4, 24.6, 41.4, 39.9, and 37.0 µg mL(-1), respectively. Linearity was observed in the range of 20.8-980 µg mL(-1) with correlation coefficients > 0.99. The application holds great promise in the area of forensic chemistry where development of reliable analytical methods for the detection, identification, and quantification of DMT are crucial and also in pharmaceutical analysis where DMT might be prepared for use in human clinical studies.

  2. Greenhouse Gas and Criteria Air Pollutant Emission Reductions from Forest Fuel Treatment Projects in Placer County, California

    NASA Astrophysics Data System (ADS)

    Saah, D. S.; Moritz, M.; Ganz, D. J.; Stine, P. A.; Moody, T.

    2010-12-01

    Years of successful fire suppression activities have left forests unnaturally dense, overstocked, and with high hazardous fuel loads. Wildfires, particularly those of high severity, may dramatically reduce carbon stocks and convert forested lands from carbon sinks to decades-long carbon sources . Forest resource managers are currently pursuing fuels reduction and mitigation strategies to reduce wildfire risk and maintain carbon stocks. These projects include selective thinning and removal of trees and brush to return forest ecosystems to more natural stocking levels, resulting in a more fire-resilient forest that in theory would retain higher carry capacity for standing above ground carbon. Resource managers are exploring the possibility of supporting these local forest management projects by offering greenhouse gas (GHG) offsets to project developers that require GHG emissions mitigation. Using robust field data, this research project modeled three types of carbon benefits that could be realized from forest management: 1. Fuels treatments in the study area were shown to reduce the GHG and Criteria Air Pollutant emissions from wildfires by decreasing the probability, extent, and severity of fires and the corresponding loss in forest carbon stocks; 2. Biomass utilization from fuel treatment was shown to reduce GHG and Criteria Air Pollutant emissions over the duration of the fuels treatment project compared to fossil fuel energy. 3. Management and thinning of forests in order to stimulate growth, resulting in more rapid uptake of atmospheric carbon and approaching a carbon carrying capacity stored in a forest ecosystem under prevailing environmental conditions and natural disturbance regimes.

  3. Health Cobenefits and Transportation-Related Reductions in Greenhouse Gas Emissions in the San Francisco Bay Area

    PubMed Central

    Woodcock, James; Co, Sean; Ostro, Bart; Fanai, Amir; Fairley, David

    2013-01-01

    Objectives. We quantified health benefits of transportation strategies to reduce greenhouse gas emissions (GHGE). Methods. Statistics on travel patterns and injuries, physical activity, fine particulate matter, and GHGE in the San Francisco Bay Area, California, were input to a model that calculated the health impacts of walking and bicycling short distances usually traveled by car or driving low-emission automobiles. We measured the change in disease burden in disability-adjusted life years (DALYs) based on dose–response relationships and the distributions of physical activity, particulate matter, and traffic injuries. Results: Increasing median daily walking and bicycling from 4 to 22 minutes reduced the burden of cardiovascular disease and diabetes by 14% (32 466 DALYs), increased the traffic injury burden by 39% (5907 DALYS), and decreased GHGE by 14%. Low-carbon driving reduced GHGE by 33.5% and cardiorespiratory disease burden by less than 1%. Conclusions: Increased physical activity associated with active transport could generate a large net improvement in population health. Measures would be needed to minimize pedestrian and bicyclist injuries. Together, active transport and low-carbon driving could achieve GHGE reductions sufficient for California to meet legislative mandates. PMID:23409903

  4. Effect of sulfide removal on sulfate reduction at pH 5 in a hydrogen fed gas-lift bioreactor.

    PubMed

    Bijmans, Martijn F M; Dopson, Mark; Ennin, Frederick; Lens, Piet N L; Buisman, Cees J N

    2008-11-01

    Biotechnological treatment of sulfate- and metal-ionscontaining acidic wastewaters from mining and metallurgical activities utilizes sulfate-reducing bacteria to produce sulfide that can subsequently precipitate metal ions. Reducing sulfate at a low pH has several advantages above neutrophilic sulfate reduction. This study describes the effect of sulfide removal on the reactor performance and microbial community in a high-rate sulfidogenic gas-lift bioreactor fed with hydrogen at a controlled internal pH of 5. Under sulfide removal conditions, 99% of the sulfate was converted at a hydraulic retention time of 24 h, reaching a volumetric activity as high as 51 mmol sulfate/l/d. Under nonsulfide removal conditions, <25% of the sulfate was converted at a hydraulic retention time of 24 h reaching volumetric activities of <13mmol sulfate/l/d. The absence of sulfide removal at a hydraulic retention time of 24 h resulted in an average H2S concentration of 18.2 mM (584 mg S/l). The incomplete sulfate removal was probably due to sulfide inhibition. Molecular phylogenetic analysis identified 11 separate 16S rRNA bands under sulfide stripping conditions, whereas under nonsulfide removal conditions only 4 separate 16S rRNA bands were found. This shows that a less diverse population was found in the presence of a high sulfide concentration.

  5. Potential of solar domestic hot water systems in rural areas for greenhouse gas emission reduction in Poland

    SciTech Connect

    Skowronski, P.; Wisniewski, G.

    1996-09-01

    Application of solar energy for preparing domestic hot water is one of the easiest methods of utilization of this energy. At least part of the needs for warm tap water could be covered by solar systems. At present, mainly coal is used for water heating at dwellings in rural areas in Poland. Warm tap water consumption will increase significantly in the future as standards of living are improved. This can result in the growth of electricity use and an increase in primary fuel consumption. Present and future methods of warm sanitary water generation in rural areas in Poland is discussed, and associated greenhouse gas (GHG) emissions are estimated. It is predicted that the emission of CO{sub 2} and NOx will increase. The emission of CO and CH{sub 4} will decrease because of changes in the structure of the final energy carriers used. The economic and market potentials of solar energy for preparing warm water in rural areas are discussed. It is estimated that solar systems can meet 30%-45% of the energy demand for warm water generation in rural areas at a reasonable cost, with a corresponding CO{sub 2} emission reduction. The rate of realization of the economic potential of solar water heaters depends on subsidies for the installation of equipment. 13 refs., 9 tabs.

  6. Joint carbon footprint assessment and data envelopment analysis for the reduction of greenhouse gas emissions in agriculture production.

    PubMed

    Rebolledo-Leiva, Ricardo; Angulo-Meza, Lidia; Iriarte, Alfredo; González-Araya, Marcela C

    2017-03-22

    Operations management tools are critical in the process of evaluating and implementing action towards a low carbon production. Currently, a sustainable production implies both an efficient resource use and the obligation to meet targets for reducing greenhouse gas (GHG) emissions. The carbon footprint (CF) tool allows estimating the overall amount of GHG emissions associated with a product or activity throughout its life cycle. In this paper, we propose a four-step method for a joint use of CF assessment and Data Envelopment Analysis (DEA). Following the eco-efficiency definition, which is the delivery of goods using fewer resources and with decreasing environmental impact, we use an output oriented DEA model to maximize production and reduce CF, taking into account simultaneously the economic and ecological perspectives. In another step, we stablish targets for the contributing CF factors in order to achieve CF reduction. The proposed method was applied to assess the eco-efficiency of five organic blueberry orchards throughout three growing seasons. The results show that this method is a practical tool for determining eco-efficiency and reducing GHG emissions.

  7. Polar Low genesis over the North Pacific under different global warming scenarios

    NASA Astrophysics Data System (ADS)

    Chen, Fei; von Storch, Hans; Zeng, Lili; Du, Yan

    2014-12-01

    Following an earlier climatological study of North Pacific Polar Lows by employing dynamical downscaling of NCEP1 reanalysis in the regional climate model COSMO-CLM, the characteristics of Polar Low genesis over the North Pacific under different global warming scenarios are investigated. Simulations based on three scenarios from the Special Report on Emissions Scenarios were conducted using a global climate model (ECHAM5) and used to examine systematic changes in the occurrence of Polar Lows over the twenty first century. The results show that with more greenhouse gas emissions, global air temperature would rise, and the frequency of Polar Lows would decrease. With sea ice melting, the distribution of Polar Low genesis shows a northward shift. In the scenarios with stronger warming there is a larger reduction in the number of Polar Lows.

  8. Sensitivity of future continental United States water deficit projections to general circulation models, the evapotranspiration estimation method, and the greenhouse gas emission scenario

    NASA Astrophysics Data System (ADS)

    Chang, Seungwoo; Graham, Wendy D.; Hwang, Syewoon; Muñoz-Carpena, Rafael

    2016-08-01

    Projecting water deficit under various possible future climate scenarios depends on the choice of general circulation model (GCM), reference evapotranspiration (ET0) estimation method, and Representative Concentration Pathway (RCP) trajectory. The relative contribution of each of these factors must be evaluated in order to choose an appropriate ensemble of future scenarios for water resources planning. In this study variance-based global sensitivity analysis and Monte Carlo filtering were used to evaluate the relative sensitivity of projected changes in precipitation (P), ET0, and water deficit (defined here as P-ET0) to choice of GCM, ET0 estimation method, and RCP trajectory over the continental United States (US) for two distinct future periods: 2030-2060 (future period 1) and 2070-2100 (future period 2). A total of 9 GCMs, 10 ET0 methods, and 3 RCP trajectories were used to quantify the range of future projections and estimate the relative sensitivity of future projections to each of these factors. In general, for all regions of the continental US, changes in future precipitation are most sensitive to the choice of GCM, while changes in future ET0 are most sensitive to the choice of ET0 estimation method. For changes in future water deficit, the choice of GCM is the most influential factor in the cool season (December-March), and the choice of ET0 estimation method is most important in the warm season (May-October) for all regions except the Southeast US, where GCMs and ET0 have approximately equal influence throughout most of the year. Although the choice of RCP trajectory is generally less important than the choice of GCM or ET0 method, the impact of RCP trajectory increases in future period 2 over future period 1 for all factors. Monte Carlo filtering results indicate that particular GCMs and ET0 methods drive the projection of wetter or drier future conditions much more than RCP trajectory; however, the set of GCMs and ET0 methods that produce wetter or

  9. Alternative Geothermal Power Production Scenarios

    DOE Data Explorer

    Sullivan, John

    2014-03-14

    The information given in this file pertains to Argonne LCAs of the plant cycle stage for a set of ten new geothermal scenario pairs, each comprised of a reference and improved case. These analyses were conducted to compare environmental performances among the scenarios and cases. The types of plants evaluated are hydrothermal binary and flash and Enhanced Geothermal Systems (EGS) binary and flash plants. Each scenario pair was developed by the LCOE group using GETEM as a way to identify plant operational and resource combinations that could reduce geothermal power plant LCOE values. Based on the specified plant and well field characteristics (plant type, capacity, capacity factor and lifetime, and well numbers and depths) for each case of each pair, Argonne generated a corresponding set of material to power ratios (MPRs) and greenhouse gas and fossil energy ratios.

  10. Effect of temperature on reduction of CaSO{sub 4} oxygen carrier in chemical-looping combustion of simulated coal gas in a fluidized bed reactor

    SciTech Connect

    Song, Q.L.; Xiao, R.; Deng, Z.Y.; Shen, L.H.; Xiao, J.; Zhang, M.Y.

    2008-12-15

    Chemical-looping combustion (CLC) is a promising combustion technology for gaseous and solid fuel with efficient use of energy and inherent separation of CO{sub 2}. The concept of a coal-fueled CLC system using, calcium sulfate (CaSO{sub 4}) as oxygen carrier is proposed in this study. Reduction tests of CaSO{sub 4} oxygen carrier with simulated coal gas were performed in a laboratory-scale fluidized bed reactor in the temperature range of 890-950{degree}C. A high concentration of CO{sub 2} was obtained at the initial reduction period. CaSO{sub 4} oxygen carrier exhibited high reactivity initially and decreased gradually at the late period of reduction. The sulfur release during the reduction of CaSO{sub 4} as oxygen carrier was also observed and analyzed. H{sub 2} and CO{sub 2} conversions were greatly influenced by reduction temperature. The oxygen carrier conversion and mass-based reaction rates during the reduction at typical temperatures were compared. Higher temperatures would enhance reaction rates and result in high conversion of oxygen carrier. An XRD patterns study indicated that CaS was the dominant product of reduction and the variation of relative intensity with temperature is in agreement with the solid conversion. ESEM analysis indicated that the surface structure of oxygen carrier particles changed significantly from impervious to porous after reduction. EDS analysis also demonstrated the transfer of oxygen from the oxygen carrier to the fuel gas and a certain amount of sulfur loss and CaO formation on the surface at higher temperatures. The reduction kinetics of CaSO{sub 4} oxygen carrier was explored with the shrinking unreacted-core model. The apparent kinetic parameters were obtained, and the kinetic equation well predicted the experimental data. Finally, some basic considerations on the use of CaSO{sub 4} oxygen carrier in a CLC system for solid fuels were discussed.

  11. Inventories and scenarios of nitrous oxide emissions

    NASA Astrophysics Data System (ADS)

    Davidson, Eric A.; Kanter, David

    2014-10-01

    Effective mitigation for N2O emissions, now the third most important anthropogenic greenhouse gas and the largest remaining anthropogenic source of stratospheric ozone depleting substances, requires understanding of the sources and how they may increase this century. Here we update estimates and their uncertainties for current anthropogenic and natural N2O emissions and for emissions scenarios to 2050. Although major uncertainties remain, ‘bottom-up’ inventories and ‘top-down’ atmospheric modeling yield estimates that are in broad agreement. Global natural N2O emissions are most likely between 10 and 12 Tg N2O-N yr-1. Net anthropogenic N2O emissions are now about 5.3 Tg N2O-N yr-1. Gross anthropogenic emissions by sector are 66% from agriculture, 15% from energy and transport sectors, 11% from biomass burning, and 8% from other sources. A decrease in natural emissions from tropical soils due to deforestation reduces gross anthropogenic emissions by about 14%. Business-as-usual emission scenarios project almost a doubling of anthropogenic N2O emissions by 2050. In contrast, concerted mitigation scenarios project an average decline of 22% relative to 2005, which would lead to a near stabilization of atmospheric concentration of N2O at about 350 ppb. The impact of growing demand for biofuels on future projections of N2O emissions is highly uncertain; N2O emissions from second and third generation biofuels could remain trivial or could become the most significant source to date. It will not be possible to completely eliminate anthropogenic N2O emissions from agriculture, but better matching of crop N needs and N supply offers significant opportunities for emission reductions.

  12. Increased Use of Natural Gas for Power Generation in the U.S. and the Resulting Reductions in Emissions of CO2, NOx and SO2

    NASA Astrophysics Data System (ADS)

    De Gouw, J. A.; Parrish, D. D.; Trainer, M.

    2013-12-01

    Over the past decades, natural gas has increasingly replaced coal as a fuel for electrical power generation in the U.S. As a result, there have been significant reductions in the emissions of carbon dioxide (CO2), nitrogen oxides (NOx) and sulfur dioxide (SO2). Power plant emissions are continuously measured at the stack using continuous emissions monitoring systems (CEMS) required by the EPA. Previous studies using airborne measurements have shown these CEMS measurements to be accurate. Here, we use annual emissions since 1995 from all point sources included in the CEMS database to quantify the changes in CO2, NOx and SO2 emissions that have resulted from the changing use of fuels and technologies for power generation. In 1997, 83% of electrical power in the CEMS database was generated from coal-fired power plants. In 2012, the contribution from coal had decreased to 59%, and natural gas contributed 34% of the electrical power. Natural gas-fired power plants, in particular those equipped with combined cycle technology, emit less than 50% of CO2 per kWh produced compared to coal-fired plants. As a result of the increased use of natural gas, total CO2 emissions from U.S. power plants have decreased since 2008. In addition, natural gas-fired power plants emit less NOx and far less SO2 per kWh produced than coal-fired power plants. The increased use of natural gas has therefore led to significant emissions reductions of NOx and SO2 in addition to those obtained from the implementation of emissions control systems on coal-fired power plants. The increased use of natural gas for power generation has led to significant reductions in CO2 emissions as well as improvements in U.S. air quality. We will illustrate these points with examples from airborne measurements made using the NOAA WP-3D aircraft in the Southeastern U.S. in 2013 as part of the NOAA Southeast Nexus (SENEX) study. The emissions reductions from U.S. power plants due to the increased use of natural gas will

  13. Utilization of Common Automotive Three-Way NO{sub x} Reduction Catalyst for Managing Off- Gas from Thermal Treatment of High-Nitrate Waste - 13094

    SciTech Connect

    Foster, Adam L.; Ki Song, P.E.

    2013-07-01

    Studsvik's Thermal Organic Reduction (THOR) steam reforming process has been tested and proven to effectively treat radioactive and hazardous wastes streams with high nitrate contents to produce dry, stable mineral products, while providing high conversion (>98%) of nitrates and nitrites directly to nitrogen gas. However, increased NO{sub x} reduction may be desired for some waste streams under certain regulatory frameworks. In order to enhance the NO{sub x} reduction performance of the THOR process, a common Three-Way catalytic NO{sub x} reduction unit was installed in the process gas piping of a recently completed Engineering Scale Technology Demonstration (ESTD). The catalytic DeNO{sub x} unit was located downstream of the main THOR process vessel, and it was designed to catalyze the reduction of residual NO{sub x} to nitrogen gas via the oxidation of the hydrogen, carbon monoxide, and volatile organic compounds that are inherent to the THOR process gas. There was no need for auxiliary injection of a reducing gas, such as ammonia. The unit consisted of four monolith type catalyst sections positioned in series with a gas mixing section located between each catalyst section. The process gas was monitored for NO{sub x} concentration upstream and downstream of the catalytic DeNO{sub x} unit. Conversion efficiencies ranged from 91% to 97% across the catalytic unit, depending on the composition of the inlet gas. Higher concentrations of hydrogen and carbon monoxide in the THOR process gas increased the NO{sub x} reduction capability of the catalytic DeNO{sub x} unit. The NO{sub x} destruction performance of THOR process in combination with the Three-Way catalytic unit resulted in overall system NO{sub x} reduction efficiencies of greater than 99.9% with an average NO{sub x} reduction efficiency of 99.94% for the entire demonstration program. This allowed the NO{sub x} concentration in the ESTD exhaust gas to be maintained at less than 40 parts per million (ppm), dry

  14. Scenario projections for future market potentials of biobased bulk chemicals.

    PubMed

    Dornburg, Veronika; Hermann, Barbara G; Patel, Martin K

    2008-04-01

    Three scenario projections for future market potentials of biobased bulk chemicals produced by means of white biotechnology are developed for Europe (EU-25) until the year 2050, and potential nonrenewable energy savings, greenhouse gas emission reduction, and land use consequences are analyzed. These scenarios assume benign, moderate, and disadvantageous conditions for biobased chemicals. The scenario analysis yields a broad range of values for the possible market development of white biotechnology chemicals, that is, resulting in a share of white biotechnology chemicals relative to all organic chemicals of about 7 (or 5 million tonnes), 17.5 (or 26 million tonnes), or 38% (or 113 million tonnes) in 2050. We conclude that under favorable conditions, white biotechnology enables substantial savings of nonrenewable energy use (NREU) and greenhouse gas (GHG) emissions compared to the energy use of the future production of all organic chemicals from fossil resources. Savings of NREU reach up to 17% for starch crops and up to 31% for lignocellulosic feedstock by 2050, and saving percentages for GHG emissions are in a similar range. Parallel to these environmental benefits, economic advantages of up to 75 billion Euro production cost savings arise.

  15. Sulfur cycling of intertidal Wadden Sea sediments (Konigshafen, Island of Sylt, Germany): sulfate reduction and sulfur gas emission

    NASA Astrophysics Data System (ADS)

    Kristensen, E.; Bodenbender, J.; Jensen, M. H.; Rennenberg, H.; Jensen, K. M.

    2000-05-01

    Sulfate reduction rates (SRR t) and reduced inorganic sulfur pools (RIS) in Wadden Sea sediment as well as sulfur gas emissions directly to the atmosphere were measured at intervals of 2 to 12 months from 1991 to 1994. Three stations were chosen in the intertidal embayment, Königshafen, representing the range of sediments found in the Wadden Sea: Organic-poor coarse sand, organic-poor and Arenicola marina inhabited medium sand, and organic-rich muddy sand. Maximum SRR t were 2 to 5 times higher in muddy sand than in the sandy sediments. The depth-integrated SRR t varied 12 to 13-fold on a seasonal basis at the three stations. Although temperature controls biochemical processes, the overall control is more complex due to the simultaneous influence of other seasonal factors such as availability of organic matter and oxidation level of surface sediment. The sedimentary RIS pools were low due to iron limitation and contained only 30% acid volatile sulfur (AVS). Muddy sand had up to an order of magnitude more RIS than the two sandy sediments. The turnover of RIS was rapid (turnover time from ˜1 to 32 h), fastest during summer and at the sandy stations. The emission of S-gases was dominated by H 2S during summer (45-67% of the total), and was highest in muddy and lowest in coarse sand. H 2S was less important in early spring (3-49% of the total). Other sulfur gases, such as COS, DMS and CS 2, each accounted for less than 20% of the total sulfur emissions with no specific temporal and spatial pattern. Due to the low content of metals in the sediment, the reduced sulfur pools are cycled rapidly with chemical and biological reoxidation at oxic-anoxic boundaries as a major sink. Thus, the emissions of H 2S account for less than 1‰ of the sulfide produced.

  16. Scenarios for Benefits Analysis of Energy Research, Development,Demonstration and Deployment

    SciTech Connect

    Gumerman, Etan; Marnay, Chris

    2005-09-07

    For at least the last decade, evaluation of the benefits of research, development, demonstration, and deployment (RD3) by the U.S. Department of Energy has been conducted using deterministic forecasts that unrealistically presume we can precisely foresee our future 10, 25,or even 50 years hence. This effort tries, in a modest way, to begin a process of recognition that the reality of our energy future is rather one rife with uncertainty. The National Energy Modeling System (NEMS) is used by the Department of Energy's Office of Energy Efficiency and Renewable Energy (EE) and Fossil Energy (FE) for their RD3 benefits evaluation. In order to begin scoping out the uncertainty in these deterministic forecasts, EE and FE designed two futures that differ significantly from the basic NEMS forecast. A High Fuel Price Scenario and a Carbon Cap Scenario were envisioned to forecast alternative futures and the associated benefits. Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) implemented these scenarios into its version of NEMS,NEMS-LBNL, in late 2004, and the Energy Information Agency created six scenarios for FE in early 2005. The creation and implementation of the EE-FE scenarios are explained in this report. Both a Carbon Cap Scenario and a High Fuel Price Scenarios were implemented into the NEMS-LBNL. EIA subsequently modeled similar scenarios using NEMS. While the EIA and LBNL implementations were in some ways rather different, their forecasts do not significantly diverge. Compared to the Reference Scenario, the High Fuel Price Scenario reduces energy consumption by 4 percent in 2025, while in the EIA fuel price scenario (known as Scenario 4) reduction from its corresponding reference scenario (known as Scenario 0) in 2025 is marginal. Nonetheless, the 4 percent demand reduction does not lead to other cascading effects that would significantly differentiate the two scenarios. The LBNL and EIA carbon scenarios were mostly identical. The only major difference

  17. Selective catalytic reduction system and process for control of NO.sub.x emissions in a sulfur-containing gas stream

    DOEpatents

    Sobolevskiy, Anatoly

    2015-08-11

    An exhaust gas treatment process, apparatus, and system for reducing the concentration of NOx, CO and hydrocarbons in a gas stream, such as an exhaust stream (29), via selective catalytic reduction with ammonia is provided. The process, apparatus and system include a catalytic bed (32) having a reducing only catalyst portion (34) and a downstream reducing-plus-oxidizing portion (36). Each portion (34, 36) includes an amount of tungsten. The reducing-plus-oxidizing catalyst portion (36) advantageously includes a greater amount of tungsten than the reducing catalyst portion (36) to markedly limit ammonia salt formation.

  18. Reduction of dioxin emission by a multi-layer reactor with bead-shaped activated carbon in simulated gas stream and real flue gas of a sinter plant.

    PubMed

    Hung, Pao Chen; Lo, Wei Chiao; Chi, Kai Hsien; Chang, Shu Hao; Chang, Moo Been

    2011-01-01

    A laboratory-scale multi-layer system was developed for the adsorption of PCDD/Fs from gas streams at various operating conditions, including gas flow rate, operating temperature and water vapor content. Excellent PCDD/F removal efficiency (>99.99%) was achieved with the multi-layer design with bead-shaped activated carbons (BACs). The PCDD/F removal efficiency achieved with the first layer adsorption bed decreased as the gas flow rate was increased due to the decrease of the gas retention time. The PCDD/F concentrations measured at the outlet of the third layer adsorption bed were all lower than 0.1 ng I-TEQ Nm⁻³. The PCDD/Fs desorbed from BAC were mainly lowly chlorinated congeners and the PCDD/F outlet concentrations increased as the operating temperature was increased. In addition, the results of pilot-scale experiment (real flue gases of an iron ore sintering plant) indicated that as the gas flow rate was controlled at 15 slpm, the removal efficiencies of PCDD/F congeners achieved with the multi-layer reactor with BAC were better than that in higher gas flow rate condition (20 slpm). Overall, the lab-scale and pilot-scale experiments indicated that PCDD/F removal achieved by multi-layer reactor with BAC strongly depended on the flow rate of the gas stream to be treated.

  19. Catalytic activity of oxidized (combusted) oil shale for removal of nitrogen oxides with ammonia as a reductant in combustion gas streams, Part 1

    SciTech Connect

    Reynolds, J.G.; Taylor, R.W.; Morris, C.J.

    1992-06-10

    Oxidized oil shale from the combustor in the LLNL hot recycle solids oil shale retorting process has been studied as a catalyst for removing nitrogen oxides from laboratory gas streams using NH{sub 3} as areductant. Combusted Green River oil shale heated at 10{degrees}C/min in an Ar/O{sub 2}/NO/NH{sub 3} mixture ({approximately}93%/6%/2000 ppm/4000 ppm) with a gas residence time of {approximately}0.6 sec exhibited NO removal between 250 and 500{degrees}C, with maximum removal of 70% at {approximately}400{degrees}C. Under isothermal conditions with the same gas mixture, the maximum NO removal was found to be {approximately}64%. When CO{sub 2} was added to the gas mixture at {approximately}8%, the NO removal dropped to {approximately}50%. However, increasing the gas residence time to {approximately}1.2 sec, increased NO removal to 63%. These results are not based on optimized process conditions, but indicate oxidized (combusted) oil shale is an effective catalyst for NO removal from combustion gas streams using NH{sub 3} as the reductant.

  20. Approach of UV nanoimprint lithography using template with gas-permeable and gaseous adsorption for reduction of air-trapping issue

    NASA Astrophysics Data System (ADS)

    Takei, Satoshi; Sugino, Naoto; Kameda, Takao; Nakajima, Shinya; Hanabata, Makoto

    2016-10-01

    In this paper, we studied a novel approach, UV nanoimprint lithography using glucose-based template with gaspermeable and gaseous adsorption for reduction of air-trapping issue. The air-trapping issue in UV nanoimprint lithography resist is a cause of pattern failure in resist or UV curable materials. The results of 180 nm dense line patterning of UV curable patterning materials containing acetone in UV nanoimprint lithography using glucose-based template with gas-permeable and gaseous adsorption were effected to reduce the pattern failure as compared with that of the poly(dimethylsiloxane) without gas-permeable and gaseous adsorption as the reference. The proposed UV nanoimprint lithography using glucose-based template with gas-permeable and gaseous adsorption is one of the most promising processes ready to be investigated for mass-production of photomask applications.

  1. Investigation into the effects of vermiculite on NOx reduction and additives on sooting and exhaust infrared signature from a gas-turbine combustor. Master's thesis

    SciTech Connect

    Engel, K.R.

    1990-09-01

    An experimental investigation was conducted to determine the feasibility of using catalytic reduction of NOX emissions from a typical jet engine combustor in the test cell environment. A modified T-63 combustor in combination with an instrumented 21 foot augmentation tube containing a vermiculite catalyst was used. Several methods for containing the vermiculite were attempted. Both vermiculite and vermiculite which had been coated with thiourea were used. Up to 19% reduction in NOX concentrations was obtained using the vermiculite coated with thiourea, however the pressure loss across the catalyst bed was measured to be 36 in. H2O. The techniques used proved ineffective and unacceptable for gas turbine engine test cell applications. Tests were conducted using both Wynn's 15/590 and Catane TM (ferrocene) fuel supplements in order to determine their effectiveness for soot reduction and whether or not the exhaust plume could be changed.

  2. Arctic Planning Scenarios: Scenario #2 - Safety and Security Scenario

    DTIC Science & Technology

    2011-07-01

    Narcotics are traded in bulk with cocaine & ecstasy going west and heroin going east; The US land border is now sealed behind a physical fence...nationale, 2011 Abstract …….. With the change in Northern climate over the past decade, current policy and media discussions have focused on...characterize legislation and policy on the Arctic, with a view to developing scenarios for future planning. This report presents one of two

  3. Reduction of Sn-Bearing Iron Concentrate with Mixed H2/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

    NASA Astrophysics Data System (ADS)

    You, Zhixiong; Li, Guanghui; Wen, Peidan; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    2017-02-01

    The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H2/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H2, 28.5 vol pct CO, and 66.5 vol pct CO2 (CO/(CO + CO2) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H2, 50 vol pct CO (CO/(CO + CO2) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.

  4. Dark current reduction of Ge photodetector by GeO₂ surface passivation and gas-phase doping.

    PubMed

    Takenaka, Mitsuru; Morii, Kiyohito; Sugiyama, Masakazu; Nakano, Yoshiaki; Takagi, Shinichi

    2012-04-09

    We have investigated the dark current of a germanium (Ge) photodetector (PD) with a GeO₂ surface passivation layer and a gas-phase-doped n+/p junction. The gas-phase-doped PN diodes exhibited a dark current of approximately two orders of magnitude lower than that of the diodes formed by a conventional ion implantation process, indicating that gas-phase doping is suitable for low-damage PN junction formation. The bulk leakage (Jbulk) and surface leakage (Jsurf) components of the dark current were also investigated. We have found that GeO₂ surface passivation can effectively suppress the dark current of a Ge PD in conjunction with gas-phase doping, and we have obtained extremely low values of Jbulk of 0.032 mA/cm² and Jsurf of 0.27 μA/cm.

  5. Ferric iron-bearing sediments as a mineral trap for CO2 sequestration: Iron reduction using sulfur-bearing waste gas

    USGS Publications Warehouse

    Palandri, J.L.; Kharaka, Y.K.

    2005-01-01

    We present a novel method for geologic sequestration of anthropogenic CO2 in ferrous carbonate, using ferric iron present in widespread redbeds and other sediments. Iron can be reduced by SO2 that is commonly a component of flue gas produced by combustion of fossil fuel, or by adding SO2 or H2S derived from other industrial processes to the injected waste gas stream. Equilibrium and kinetically controlled geochemical simulations at 120 bar and 50 and 100 ??C with SO2 or H2S show that iron can be transformed almost entirely to siderite thereby trapping CO2, and simultaneously, that sulfur can be converted predominantly to dissolved sulfate. If there is an insufficient amount of sulfur-bearing gas relative to CO2 as for typical flue gas, then some of the iron is not reduced, and some of the CO2 is not sequestered. If there is an excess of sulfur-bearing gas, then complete iron reduction is ensured, and some of the iron precipitates as pyrite or other solid iron sulfide, depending on their relative precipitation kinetics. Gas mixtures with insufficient sulfur relative to CO2 can be used in sediments containing Ca, Mg, or other divalent metals capable of precipitating carbonate minerals. For quartz arenite with an initial porosity of 21% and containing 0.25 wt.% Fe2O3, approximately 0.7 g of CO2 is sequestered per kg of rock, and the porosity decrease is less than 0.03%. Sequestration of CO2 using ferric iron has the advantage of disposing of SO2 that may already be present in the combustion gas. ?? 2005 Published by Elsevier B.V.

  6. Impact on water surface due to deepwater gas blowouts.

    PubMed

    Premathilake, Lakshitha T; Yapa, Poojitha D; Nissanka, Indrajith D; Kumarage, Pubudu

    2016-11-15

    This paper presents a study on the impact of underwater gas blowouts near the ocean surface, which has a greater relevance to assess Health, Safety, and Environmental risks. In this analysis the gas flux near the surface, reduction of bulk density, and gas surfacing area are studied for different scenarios. The simulations include a matrix of scenarios for different release depths, release rates, and initial bubble size distributions. The simulations are carried out using the MEGADEEP model, for a location in East China Sea. Significant changes in bulk density and gas surface flux near the surface are observed under different release conditions, which can pose a potential threat for cleanup and rescue operations. Furthermore, the effect of hydrate formation on gas surfacing is studied for much greater release depths. The type of outcomes of this study is important to conduct prior risk assessments and contingency planning for underwater gas blowouts.

  7. Scenario development in China's electricity sector

    SciTech Connect

    Steenhof, P.A.; Fulton, W.

    2007-07-15

    The continuing growth of China's electricity sector will affect global environmental and economic sustainability due to its impacts on greenhouse gas emissions and global resource depletion. In 2005, the generation of electricity in China resulted in the emissions of 2290 million metric tonnes of carbon dioxide (approximately 53% of the nation's total) and required 779 million metric tonnes of coal (approximately 50% of China's total coal consumption). These figures are expected to increase with China's economic growth. In order to gauge the range in which fuel consumption and CO{sub 2} emissions could grow a scenario-based conceptual model has been developed by the authors (published in this journal). The application and analysis of this shows that under a business as usual (BAU) scenario, electricity generation could contribute upwards of 56% of China's energy related greenhouse gas emissions by 2020. Meanwhile, consumption of coal will also increase, growing to nearly 60% of total national demand by 2020. However, variations in a number of key drivers could produce significant deviation from the BAU scenario. With accelerated economic output, even with greater technological advances and greater potential to bring natural gas on stream, carbon dioxide emissions would rise 10% above the BAU. Alternatively, in a scenario where China's economy grows at a tempered pace, less investment would be available for advanced technologies, developing natural gas infrastructure, or nuclear energy. In this scenario, reduced economic growth and electricity demand would thereby be countered by reduced efficiency and a higher contribution of coal.

  8. Dual-tree complex wavelet transform and SVD based acoustic noise reduction and its application in leak detection for natural gas pipeline

    NASA Astrophysics Data System (ADS)

    Yu, Xuchao; Liang, Wei; Zhang, Laibin; Jin, Hao; Qiu, Jingwei

    2016-05-01

    During the last decades, leak detection for natural gas pipeline has become one of the paramount concerns of pipeline operators and researchers across the globe. However, acoustic wave method has been proved to be an effective way to identify and localize leakage for gas pipeline. Considering the fact that noises inevitably exist in the acoustic signals collected, noise reduction should be enforced on the signals for subsequent data mining and analysis. Thus, an integrated acoustic noise reduction method based on DTCWT and SVD is proposed in this study. The method is put forward based on the idea that noise reduction strategy should match the characteristics of the noisy signal. According to previous studies, it is known that the energy of acoustic signals collected under leaking condition is mainly concentrated in low-frequency portion (0-100 Hz). And ultralow-frequency component (0-5 Hz), which is taken as the characteristic frequency band in this study, can propagate a relatively longer distance and be captured by sensors. Therefore, in order to filter the noises and to reserve the characteristic frequency band, DTCWT is taken as the core to conduct multilevel decomposition and refining for acoustic signals and SVD is employed to eliminate noises in non-characteristic bands. Both simulation and field experiments show that DTCWT-SVD is an excellent method for acoustic noise reduction. At the end of this study, application in leakage localization shows that it becomes much easier and a little more accurate to estimate the location of leak hole after noise reduction by DTCWT-SVD.

  9. Greenhouse gas and air pollutant emission reduction potentials of renewable energy--case studies on photovoltaic and wind power introduction considering interactions among technologies in Taiwan.

    PubMed

    Kuo, Yu-Ming; Fukushima, Yasuhiro

    2009-03-01

    To achieve higher energy security and lower emission of greenhouse gases (GHGs) and pollutants, the development of renewable energy has attracted much attention in Taiwan. In addition to its contribution to the enhancement of reliable indigenous resources, the introduction of renewable energy such as photovoltaic (PV) and wind power systems reduces the emission of GHGs and air pollutants by substituting a part of the carbon- and pollutant-intensive power with power generated by methods that are cleaner and less carbon-intensive. To evaluate the reduction potentials, consequential changes in the operation of different types of existing power plants have to be taken into account. In this study, a linear mathematical programming model is constructed to simulate a power mix for a given power demand in a power market sharing a cost-minimization objective. By applying the model, the emission reduction potentials of capacity extension case studies, including the enhancement of PV and wind power introduction at different scales, were assessed. In particular, the consequences of power mix changes in carbon dioxide, nitrogen oxides, sulfur oxides, and particulates were discussed. Seasonally varying power demand levels, solar irradiation, and wind strength were taken into account. In this study, we have found that the synergetic reduction of carbon dioxide emission induced by PV and wind power introduction occurs under a certain level of additional installed capacity. Investigation of a greater variety of case studies on scenario development with emerging power sources becomes possible by applying the model developed in this study.

  10. Greenhouse gas scenario in Indian continent

    NASA Astrophysics Data System (ADS)

    Singh, T. N.

    1999-12-01

    Global climate change depicts energy exchange balance between the earth and atmosphere and the space. The balance is affected by human activities -- burning of fuel -- fossil or biological generating carbon dioxide, nitrous oxide or trace gases. Accumulation of these gases in the atmosphere may follow intensification of green house effect and cause global sea warming. Warming may affect agriculture, forestry, water resources and rising or falling of levels. The burning of fuel is for the generation of commercial energy -- electricity, household energy -- cooking, heating or burning of bushes, waste product and biomass. The world population distribution reveals heavy tilt in terms of growth rate and the cumulative figure. Nearly 80% of the world population is in the developing economy with only 20% resource available to them. The energy demand in five major Asian developing economy for the year 1990 is summarized.

  11. Dissimilatory reduction of FeIII (EDTA) with microorganisms in the system of nitric oxide removal from the flue gas by metal chelate absorption.

    PubMed

    Ma, Bi-yao; Li, Wei; Jing, Guo-hua; Shi, Yao

    2004-01-01

    In the system of nitric oxide removal from the flue gas by metal chelate absorption, it is an obstacle that ferrous absorbents are easily oxidized by oxygen in the flue gas to ferric counterparts, which are not capable of binding NO. By adding iron metal or electrochemical method, FeIII(EDTA) can be reduced to FeII(EDTA). However, there are various drawbacks associated with these techniques. The dissimilatory reduction of FeIII(EDTA) with microorganisms in the system of nitric oxide removal by metal chelate absorption was investigated. Ammonium salt instead of nitrate was used as the nitrogen source, as nitrates inhibited the reduction of FeIII due to the competition between the two electron acceptors. Supplemental glucose and lactate stimulated the formation of FeII more than ethanol as the carbon sources. The microorganisms cultured at 50 degrees C were not very sensitive to the other experimental temperature, the reduction percentage of FeIII varied little with the temperature range of 30-50 degrees C. Concentrated Na2CO3 solution was added to adjust the solution pH to an optimal pH range of 6-7. The overall results revealed that the dissimilatory ferric reducing microorganisms present in the mix-culture are probably neutrophilic, moderately thermophilic FeIII reducers.

  12. Nuclear Security Futures Scenarios.

    SciTech Connect

    Keller, Elizabeth James Kistin; Warren, Drake Edward; Hayden, Nancy Kay; Passell, Howard D.; Malczynski, Leonard A.; Backus, George A.

    2017-01-01

    This report provides an overview of the scenarios used in strategic futures workshops conducted at Sandia on September 21 and 29, 2016. The workshops, designed and facilitated by analysts in Center 100, used scenarios to enable thought leaders to think collectively about the changing aspects of global nuclear security and the potential implications for the US Government and Sandia National Laboratories.

  13. Review of Tools for Energy Use and Greenhouse Gas Reduction Applicable to Small- and Medium-Sized Communities

    EPA Science Inventory

    Considerable attention has already been given to ways of assessing and reducing transportation energy use and greenhouse gas emissions in large cities. This presentation provides a review of what tools, if any, may be used to assess and reduce transportation energy use and green...

  14. Optimization of Wastewater Lift Stations for Reduction of Energy Usage and Greenhouse Gas Emissions (WERF Report INFR3R11)

    EPA Science Inventory

    One of the major contributions of Greenhouse Gas (GHG) emissions from water resource recovery facilities results from the energy used by the pumping regime of the lift stations. This project demonstrated an energy-efficient control method of lift station system operation that uti...

  15. Exposure scenarios for workers.

    PubMed

    Marquart, Hans; Northage, Christine; Money, Chris

    2007-12-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate considerations of both human health and the environment. Specific aspects are relevant for worker exposure. Gathering information on the uses of the chemical is an important step in developing an Exposure Scenario. In-house information at manufacturers is an important source. Downstream users can contribute information through direct contact or through their associations. Relatively simple approaches (Tier 1 tools, such as the ECETOC Targeted Risk Assessment and the model EASE) can be used to develop broad Exposure Scenarios that cover many use situations. These approaches rely on the categorisation of just a few determinants, including only a small number of risk management measures. Such approaches have a limited discriminatory power and are rather conservative. When the hazard of the substance or the complexity of the exposure situation require a more in-depth approach, further development of the Exposure Scenarios with Tier 2 approaches is needed. Measured data sets of worker exposure are very valuable in a Tier 2 approach. Some downstream user associations have attempted to build Exposure Scenarios based on measured data sets. Generic Tier 2 tools for developing Exposure Scenarios do not exist yet. To enable efficient development of the worker exposure part of Exposure Scenarios a further development of Tier 1 and Tier 2 tools is needed. Special attention should be given to user friendliness and to the validity (boundaries) of the approaches. The development of standard worker exposure descriptions or full Exposure Scenarios by downstream user branches in cooperation with manufacturers and importers is recommended.

  16. Mars base buildup scenarios

    SciTech Connect

    Blacic, J.D.

    1985-01-01

    Two surface base build-up scenarios are presented in order to help visualize the mission and to serve as a basis for trade studies. In the first scenario, direct manned landings on the Martian surface occur early in the missions and scientific investigation is the main driver and rationale. In the second scenario, early development of an infrastructure to exploite the volatile resources of the Martian moons for economic purposes is emphasized. Scientific exploration of the surface is delayed at first, but once begun develops rapidly aided by the presence of a permanently manned orbital station.

  17. Partitioning of mercury, arsenic, selenium, boron, and chloride in a full-scale coal combustion process equipped with selective catalytic reduction, electrostatic precipitation, and flue gas desulfurization systems

    SciTech Connect

    Chin-Min Cheng; Pauline Hack; Paul Chu; Yung-Nan Chang; Ting-Yu Lin; Chih-Sheng Ko; Po-Han Chiang; Cheng-Chun He; Yuan-Min Lai; Wei-Ping Pan

    2009-09-15

    A full-scale field study was carried out at a 795 MWe coal-fired power plant equipped with selective catalytic reduction (SCR), an electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD) systems to investigate the distribution of selected trace elements (i.e., mercury, arsenic, selenium, boron, and chloride) from coal, FGD reagent slurry, makeup water to flue gas, solid byproduct, and wastewater streams. Flue gases were collected from the SCR outlet, ESP inlet, FGD inlet, and stack. Concurrent with flue gas sampling, coal, bottom ash, economizer ash, and samples from the FGD process were also collected for elemental analysis. By combining plant operation parameters, the overall material balances of selected elements were established. The removal efficiencies of As, Se, Hg, and B by the ESP unit were 88, 56, 17, and 8%, respectively. Only about 2.5% of Cl was condensed and removed from flue gas by fly ash. The FGD process removed over 90% of Cl, 77% of B, 76% of Hg, 30% of Se, and 5% of As. About 90% and 99% of the FGD-removed Hg and Se were associated with gypsum. For B and Cl, over 99% were discharged from the coal combustion process with the wastewater. Mineral trona (trisodium hydrogendicarbonate dehydrate, Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O) was injected before the ESP unit to control the emission of sulfur trioxide (SO{sub 3}). By comparing the trace elements compositions in the fly ash samples collected from the locations before and after the trona injection, the injection of trona did not show an observable effect on the partitioning behaviors of selenium and arsenic, but it significantly increased the adsorption of mercury onto fly ash. The stack emissions of mercury, boron, selenium, and chloride were for the most part in the gas phase. 47 refs., 3 figs., 11 tabs.

  18. Suppression of Fusarium wilt of cucumber by ammonia gas fumigation via reduction of Fusarium population in the field.

    PubMed

    Zhao, Jun; Mei, Zhong; Zhang, Xu; Xue, Chao; Zhang, Chenzhi; Ma, Tengfei; Zhang, Shusheng

    2017-02-23

    Cucumber plants subjected to consecutive monoculture for 9 years were found to suffer from severe Fusarium wilt disease, caused by the soil-borne fungus Fusarium oxysporum f. sp. Cucumerinum J. H. Owen. In the present study, greenhouse experiments were performed to evaluate the influence of ammonia gas fumigation on Fusarium wilt suppression, fungal abundance and fungal community composition. Results showed that ammonia gas fumigation remarkably reduced disease incidence from 80% to 27%, resulting in a four-fold increase in yield, compared to the control. Total fungal abundance declined dramatically after fumigation and reached the lowest level at day 32, at 243 times lower than the control. Moreover, fumigation significantly increased soil fungal diversity, though it also decreased considerably coinciding with cucumber growth. Fumigation also significantly altered soil fungal community composition, relative to the control. Fusarium was strongly inhibited by fumigation in both relative abundance (3.8 times lower) and targeted quantification (a decrease of 167 fold). Collectively, the application of ammonia gas fumigation to control Fusarium wilt of cucumber resulted in a re-assembly of the fungal community to resemble that of a non-disease conducive consortium. Additional strategies, such as bioorganic fertilizer application, may still be required to develop sustainable disease suppression following fumigation.

  19. Suppression of Fusarium wilt of cucumber by ammonia gas fumigation via reduction of Fusarium population in the field

    PubMed Central

    Zhao, Jun; Mei, Zhong; Zhang, Xu; Xue, Chao; Zhang, Chenzhi; Ma, Tengfei; Zhang, Shusheng

    2017-01-01

    Cucumber plants subjected to consecutive monoculture for 9 years were found to suffer from severe Fusarium wilt disease, caused by the soil-borne fungus Fusarium oxysporum f. sp. Cucumerinum J. H. Owen. In the present study, greenhouse experiments were performed to evaluate the influence of ammonia gas fumigation on Fusarium wilt suppression, fungal abundance and fungal community composition. Results showed that ammonia gas fumigation remarkably reduced disease incidence from 80% to 27%, resulting in a four-fold increase in yield, compared to the control. Total fungal abundance declined dramatically after fumigation and reached the lowest level at day 32, at 243 times lower than the control. Moreover, fumigation significantly increased soil fungal diversity, though it also decreased considerably coinciding with cucumber growth. Fumigation also significantly altered soil fungal community composition, relative to the control. Fusarium was strongly inhibited by fumigation in both relative abundance (3.8 times lower) and targeted quantification (a decrease of 167 fold). Collectively, the application of ammonia gas fumigation to control Fusarium wilt of cucumber resulted in a re-assembly of the fungal community to resemble that of a non-disease conducive consortium. Additional strategies, such as bioorganic fertilizer application, may still be required to develop sustainable disease suppression following fumigation. PMID:28230182

  20. GLOBAL ALTERNATIVE FUTURE SCENARIOS

    EPA Science Inventory

    One way to examine possible future outcomes for environmental protection is through the development and analysis of alternative future scenarios. This type of assessment postulates two or more different paths that social and environmental development might take, using correspond...

  1. Emission scenarios: Explaining differences

    NASA Astrophysics Data System (ADS)

    Iyer, Gokul; Edmonds, James

    2017-01-01

    Carbon dioxide emission scenarios rely on a number of assumptions about how societies will develop in the future, creating uncertainty in projections. Now, research reveals the sensitivity of emission estimates to some of these assumptions.

  2. Reduction of carbon dioxide gas formation at the anode of a direct methanol fuel cell using chemically enhanced solubility

    NASA Astrophysics Data System (ADS)

    Lundin, Michael D.; McCready, Mark J.

    The production of CO 2 gas at the DMFC anode leads to dramatic increases in pumping power requirements and reduced power output because of mass transfer limitations as bubble trains form in the channels of larger stacks. Experimental observations taken in a 5 cm 2 DMFC test cell operated at 60 °C, 1 atm, and with a methanol/water fuel flow rates of 5-10 cm 3 min -1 indicate that the rate of bubble formation can be reduced by increasing the fuel flow because more liquid is available for the CO 2 to dissolve in. Further observations indicate that KOH and LiOH added to the fuel eliminates CO 2 gas formation in situ at low concentrations because of the greatly increased solubility that results. A mathematical model for the volumetric rate of CO 2 gas production that includes effects of temperature and solubility is developed and extended to include the effects of hydroxide ions in solution. The model is used to predict the onset location of gas formation in the flow field as well as the void fraction at any point in the flow field. Predictions from the model agree very well with our experiments. Model predictions explain differences in the initial location of bubble formation for fuel solutions pre-saturated with CO 2 as opposed to CO 2-free solutions. Experiments with KOH and LiOH added to fuel solutions confirm the validity of the model extension that includes solubility that is enhanced by chemical reaction. Experiments with LiOH, KOH, and ammonium hydroxide show that the long-term durability of standard Pt-Ru/Nafion ®/Pt membrane electrode assemblies is compromised because of the presence of lithium, potassium, and ammonium cations that interact with the Nafion ® membrane and result in increasing the ohmic limitations of the polymer electrolyte membrane. Experiments with Ca(OH) 2, while reducing gas formation, precipitate the product CaCO 3 out of solution too rapidly for downstream filtering, blocking channels in the flow field.

  3. Carrier dynamics and the role of surface defects: Designing a photocatalyst for gas-phase CO2 reduction

    SciTech Connect

    Hoch, Laura B.; Szymanski, Paul; Ghuman, Kulbir Kaur; He, Le; Liao, Kristine; Qiao, Qiao; Reyes, Laura M.; Zhu, Yimei; El-Sayed, Mostafa A.; Singh, Chandra Veer; Ozin, Geoffrey A.

    2016-11-28

    In2O3-x(OH)y nanoparticles have been shown to function as an effective gas-phase photocatalyst for the reduction of CO2 to CO via the reverse water–gas shift reaction. Their photocatalytic activity is strongly correlated to the number of oxygen vacancy and hydroxide defects present in the system. To better understand how such defects interact with photogenerated electrons and holes in these materials, we have studied the relaxation dynamics of In2O3-x(OH)y nanoparticles with varying concentration of defects using two different excitation energies corresponding to above-band-gap (318-nm) and near-band-gap (405-nm) excitations. Our results demonstrate that defects play a significant role in the excited-state, charge relaxation pathways. Higher defect concentrations result in longer excited-state lifetimes, which are attributed to improved charge separation. This correlates well with the observed trends in the photocatalytic activity. These results are further supported by density-functional theory calculations, which confirm the positions of oxygen vacancy and hydroxide defect states within the optical band gap of indium oxide. This enhanced understanding of the role these defects play in determining the optoelectronic properties and charge carrier dynamics can provide valuable insight toward the rational development of more efficient photocatalytic materials for CO2 reduction.

  4. Effect of Precursor Selection on the Photocatalytic Performance of Indium Oxide Nanomaterials for Gas-Phase CO 2 Reduction

    SciTech Connect

    Hoch, Laura B.; He, Le; Qiao, Qiao; Liao, Kristine; Reyes, Laura M.; Zhu, Yimei; Ozin, Geoffrey A.

    2016-06-01

    Nonstoichiometric indium oxide nanoparticles, In2O3–x(OH)y, have been shown to function as active photocatalysts for gas-phase CO2 reduction under simulated solar irradiation. We demonstrate that the choice of starting material has a strong effect on the photocatalytic activity of indium oxide nanoparticles. We also examine three indium oxide materials prepared via the thermal decomposition of either indium(III) hydroxide or indium(III) nitrate and correlate their stability and photocatalytic activity to the number and type of defect present in the material. Furthermore, we use 13CO2 isotope-tracing experiments to clearly identify the origins of the observed carbon-containing products. Significantly, we find that the oxidizing nature of the precursor anion has a substantial impact on the defect formation within the sample. Our study demonstrates the importance of surface defects in designing an active heterogeneous photocatalyst and provides valuable insight into key parameters for the precursor design, selection, and performance optimization of materials for gas-phase CO2 reduction.

  5. Experimental and modeling study of the effects of multicomponent gas additives on selective non-catalytic reduction process.

    PubMed

    Cao, Qingxi; Wu, Shaohua; Lui, Hui; Liu, Dunyu; Qiu, Penghua

    2009-08-01

    The influence of multicomponent additives on NO reduction by selective non-catalytic reduction process has been investigated experimentally in an electricity-heated tube reactor. The multicomponent additives are composed of two species of CO, CH(4) and H(2), and the molar ratio of their two components varies from 1/3 to 3/1. The results show that all the investigated additives could decrease the optimal temperature for NO reduction effectively, but the contributions of their components are different. The performance of multicomponent additive composed of CO and CH(4) depends mainly on CH(4) component. The function of CO component is shifting the temperature window for NO reduction to lower temperature slightly and narrowing the temperature window a little. The temperature window with multicomponent additive composed of H(2) and CH(4) is distinct from that with its each component, so both H(2) and CH(4) component make important contributions. While the fraction of CO is no more than that of H(2) in multicomponent additives composed of them, the performance of multicomponent additives is dominated by H(2) component; while the fraction of CO becomes larger, the influence of CO component becomes notable. Qualitatively the modeling results using a detailed chemical kinetic mechanism exhibit the same characteristics of the temperature window shift as observed experimentally. By reaction mechanism analysis, the distinct influences of CO, CH(4) or H(2) component on the property of multicomponent additive are mainly caused by the different production rates of (*)OH radical in their own oxidation process.

  6. O-atom transport catalysis by atomic cations in the gas phase: reduction of N2O by CO.

    PubMed

    Blagojevic, Voislav; Orlova, Galina; Bohme, Diethard K

    2005-03-16

    Atomic cations (26), M+, have been shown to lie within a thermodynamic window for O-atom transport catalysis of the reduction of N2O by CO and have been checked for catalytic activity at room temperature with kinetic measurements using an inductively-coupled plasma/selected-ion flow tube (ICP/SIFT) tandem mass spectrometer. Only 10 of these 26 atomic cations were seen to be catalytic: Ca+, Fe+, Ge+, Sr+, Ba+, Os+, Ir+, Pt+, Eu+, and Yb+. The remaining 16 cations that lie in the thermodynamic window (Cr+, Mn+, Co+, Ni+, Cu+, Se+, Mo+, Ru+, Rh+, Sn+, Te+, Re+, Pb+, Bi+, Tm+, and Lu+) react too slowly at room temperature either in the formation of MO+ or in its reduction by CO. Many of these reactions are known to be spin forbidden and a few actually may lie outside the thermodynamic window. A new measure of efficiency is introduced for catalytic cycles that allows the discrimination between catalytic cations on the basis of the efficiencies of the two legs of the catalytic cycle. Also, a potential-energy landscape is computed for the reduction of N2O by CO catalyzed by Fe+(6D) that vividly illustrates the operation of an ionic catalyst.

  7. Transportation Energy Futures Series. Effects of Travel Reduction and Efficient Driving on Transportation. Energy Use and Greenhouse Gas Emissions

    SciTech Connect

    Porter, C. D.; Brown, A.; DeFlorio, J.; McKenzie, E.; Tao, W.; Vimmerstedt, L.

    2013-03-01

    Since the 1970s, numerous transportation strategies have been formulated to change the behavior of drivers or travelers by reducing trips, shifting travel to more efficient modes, or improving the efficiency of existing modes. This report summarizes findings documented in existing literature to identify strategies with the greatest potential impact. The estimated effects of implementing the most significant and aggressive individual driver behavior modification strategies range from less than 1% to a few percent reduction in transportation energy use and GHG emissions. Combined strategies result in reductions of 7% to 15% by 2030. Pricing, ridesharing, eco-driving, and speed limit reduction/enforcement strategies are widely judged to have the greatest estimated potential effect, but lack the widespread public acceptance needed to accomplish maximum results. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  8. Transportation Energy Futures Series: Effects of Travel Reduction and Efficient Driving on Transportation: Energy Use and Greenhouse Gas Emissions

    SciTech Connect

    Porter, C. D.; Brown, A.; DeFlorio, J.; McKenzie, E.; Tao, W.; Vimmerstedt, L.

    2013-03-01

    Since the 1970s, numerous transportation strategies have been formulated to change the behavior of drivers or travelers by reducing trips, shifting travel to more efficient modes, or improving the efficiency of existing modes. This report summarizes findings documented in existing literature to identify strategies with the greatest potential impact. The estimated effects of implementing the most significant and aggressive individual driver behavior modification strategies range from less than 1% to a few percent reduction in transportation energy use and GHG emissions. Combined strategies result in reductions of 7% to 15% by 2030. Pricing, ridesharing, eco-driving, and speed limit reduction/enforcement strategies are widely judged to have the greatest estimated potential effect, but lack the widespread public acceptance needed to accomplish maximum results. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    Commercially available activated carbon (AC) powders from different precursor materials (peat, coconut shell, coal, and hardwood) were treated with ammonia gas at 700 °C to improve their performance as oxygen reduction catalysts in neutral pH solutions used in microbial fuel cells (MFCs). The ammonia treated ACs exhibited better catalytic performance in rotating ring-disk electrode tests than their untreated precursors, with the bituminous based AC most improved, with an onset potential of Eonset = 0.12 V (untreated, Eonset = 0.08 V) and n = 3.9 electrons transferred in oxygen reduction (untreated, n = 3.6), and the hardwood based AC (treated, Eonset = 0.03 V, n = 3.3; untreated, Eonset = -0.04 V, n = 3.0). Ammonia treatment decreased oxygen content by 29-58%, increased nitrogen content to 1.8 atomic %, and increased the basicity of the bituminous, peat, and hardwood ACs. The treated coal based AC cathodes had higher maximum power densities in MFCs (2450 ± 40 mW m-2) than the other AC cathodes or a Pt/C cathode (2100 ± 1 mW m-2). These results show that reduced oxygen abundance and increased nitrogen functionalities on the AC surface can increase catalytic performance for oxygen reduction in neutral media.

  10. Analyzer for measurement of nitrogen oxide concentration by ozone content reduction in gas using solid state chemiluminescent sensor

    NASA Astrophysics Data System (ADS)

    Chelibanov, V. P.; Ishanin, G. G.; Isaev, L. N.

    2014-05-01

    Role of nitrogen oxide in ambient air is described and analyzed. New method of nitrogen oxide concentration measurement in gas phase is suggested based on ozone concentration measurement with titration by nitrogen oxide. Research of chemiluminescent sensor composition is carried out on experimental stand. The sensor produced on the base of solid state non-activated chemiluminescent composition is applied as ozone sensor. Composition is put on the surface of polymer matrix with developed surface. Sensor compositions includes gallic acid with addition of rodamine-6G. Model of interaction process between sensor composition and ozone has been developed, main products appeared during reaction are identified. The product determining the speed of luminescense appearance is found. This product belongs to quinone class. Then new structure of chemiluminescent composition was suggested, with absence of activation period and with high stability of operation. Experimental model of gas analyzer was constructed and operation algorithm was developed. It was demonstrated that developed NO measuring instrument would be applied for monitoring purposes of ambient air. This work was partially financially supported by Government of Russian Federation, Grant 074-U01

  11. Formation of new bioactive organic nitrites and their identification with gas chromatography-mass spectrometry and liquid chromatography coupled to nitrite reduction.

    PubMed

    Nilsson, Kristofer F; Lundgren, Michael; Agvald, Per; Adding, L Christofer; Linnarsson, Dag; Gustafsson, Lars E

    2011-08-01

    Nitric oxide (NO) donors, notably organic nitrates and nitrites are used therapeutically but tolerance develops rapidly, making the use of e.g. nitroglycerin difficult. NO donation in the pulmonary vascular bed might be useful in critically ill patients. Organic nitrites are not associated with tachyphylaxis but may induce methaemoglobinemia and systemic hypotension which might hamper their use. We hypothesised that new lung-selective NO donors can be identified by utilizing exhaled NO as measure for pulmonary NO donation and systemic arterial pressure to monitor hypotension and tolerance development. Solutions of alcohols and carbohydrates were reacted with NO gas and administered to ventilated rabbits for evaluation of in vivo NO donation. Chemical characterization was made by liquid chromatography with on-line nitrite reduction (LC-NO) and by gas chromatography-mass spectrometry (GC-MS). In vivo experiments showed that the hydroxyl-containing compounds treated with NO gas yielded potent NO donors, via nitrosylation to organic nitrites. Analyses by LC-NO showed that the reaction products were able to release NO in vitro. In GC-MS the reaction products were determined to be the organic nitrites, where some are new chemical entities. Non-polar donors preferentially increased exhaled NO with less effect on systemic blood pressure whereas more polar molecules had larger effects on systemic blood pressure and less on exhaled NO. We conclude that new organic nitrites suitable for intravenous administration are produced by reacting NO gas and certain hydroxyl-containing compounds in aqueous solutions. Selectivity of different organic nitrites towards the pulmonary and systemic circulation, respectively, may be determined by molecular polarity.

  12. Scenarios for gluino coannihilation

    DOE PAGES

    Ellis, John; Evans, Jason L.; Luo, Feng; ...

    2016-02-11

    In this article, we study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parametermore » space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in particular, as well as the appearance of other dark matter (co)annihilation processes. Nevertheless, LSP masses mX ≲ 8TeV with the correct dark matter density are quite possible. In the case of pure gravity mediation with additional vector-like supermultiplets, changes to the anomaly-mediated gluino mass and the threshold effects associated with these states can make the gluino almost degenerate with the LSP, and we find a similar upper bound.« less

  13. Scenarios for gluino coannihilation

    SciTech Connect

    Ellis, John; Evans, Jason L.; Luo, Feng; Olive, Keith A.

    2016-02-11

    In this article, we study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parameter space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in particular, as well as the appearance of other dark matter (co)annihilation processes. Nevertheless, LSP masses mX ≲ 8TeV with the correct dark matter density are quite possible. In the case of pure gravity mediation with additional vector-like supermultiplets, changes to the anomaly-mediated gluino mass and the threshold effects associated with these states can make the gluino almost degenerate with the LSP, and we find a similar upper bound.

  14. To what extent can zero tillage lead to a reduction in greenhouse gas emissions from temperate soils?

    PubMed Central

    Mangalassery, Shamsudheen; Sjögersten, Sofie; Sparkes, Debbie L.; Sturrock, Craig J.; Craigon, Jim; Mooney, Sacha J.

    2014-01-01

    Soil tillage practices have a profound influence on the physical properties of soil and the greenhouse gas (GHG) balance. However there have been very few integrated studies on the emission of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and soil biophysical and chemical characteristics under different soil management systems. We recorded a significantly higher net global warming potential under conventional tillage systems (26–31% higher than zero tillage systems). Crucially the 3-D soil pore network, imaged using X-ray Computed Tomography, modified by tillage played a significant role in the flux of CO2 and CH4. In contrast, N2O flux was determined mainly by microbial biomass carbon and soil moisture content. Our work indicates that zero tillage could play a significant role in minimising emissions of GHGs from soils and contribute to efforts to mitigate against climate change. PMID:24699273

  15. Status of flue-gas treatment technologies for combined SO[sub 2]/NO[sub x] reduction

    SciTech Connect

    Livengood, C.D. . Energy Systems Div.); Markussen, J.M. )

    1993-01-01

    Enactment of the Clean Air Act Amendments and passage of state legislation leading to more stringent nitrogen oxides (NO.) regulations have fueled research and development efforts on the technologies for the combined control of sulfur dioxide (SO[sub 2]) and NO[sub x]. The integrated removal of both SO[sub 2] and NO[sub x] in a single system can offer significant advantages over the use of several separate processes, including such factors as reduced system complexity, better operability, and lower costs. This paper reviews the status of a number of integrated flue-gas-cleanup systems that have reached a significant stage of development, focusing on post-combustion processes that have been tested or are ready for testing at the pilot scale or larger. A brief process description, a summary of the development status and performance achieved to date, pending commercialization issues, and process economics (when available) are given for each technology.

  16. Natural gas vehicles : Status, barriers, and opportunities.

    SciTech Connect

    Rood Werpy, M.; Santini, D.; Burnham, A.; Mintz, M.; Energy Systems

    2010-11-29

    In the United States, recent shale gas discoveries have generated renewed interest in using natural gas as a vehicular fuel, primarily in fleet applications, while outside the United States, natural gas vehicle use has expanded significantly in the past decade. In this report for the U.S. Department of Energy's Clean Cities Program - a public-private partnership that advances the energy, economic, and environmental security of the U.S. by supporting local decisions that reduce petroleum use in the transportation sector - we have examined the state of natural gas vehicle technology, current market status, energy and environmental benefits, implications regarding advancements in European natural gas vehicle technologies, research and development efforts, and current market barriers and opportunities for greater market penetration. The authors contend that commercial intracity trucks are a prime area for advancement of this fuel. Therefore, we examined an aggressive future market penetration of natural gas heavy-duty vehicles that could be seen as a long-term goal. Under this scenario using Energy Information Administration projections and GREET life-cycle modeling of U.S. on-road heavy-duty use, natural gas vehicles would reduce petroleum consumption by approximately 1.2 million barrels of oil per day, while another 400,000 barrels of oil per day reduction could be achieved with significant use of natural gas off-road vehicles. This scenario would reduce daily oil consumption in the United States by about 8%.

  17. Plenary Lecture 3: Food and the planet: nutritional dilemmas of greenhouse gas emission reductions through reduced intakes of meat and dairy foods.

    PubMed

    Millward, D Joe; Garnett, Tara

    2010-02-01

    Legally-binding legislation is now in place to ensure major reductions in greenhouse gas emissions in the UK. Reductions in intakes of meat and dairy products, which account for approximately 40% of food-related emissions, are an inevitable policy option. The present paper assesses, as far as is possible, the risk to nutritional status of such a policy in the context of the part played by these foods in overall health and well-being and their contribution to nutritional status for the major nutrients that they supply. Although meat may contribute to saturated fat intakes and a higher BMI, moderate meat consumption within generally-healthy population groups has no measurable influence on morbidity or mortality. However, high consumption of red and processed meat has been associated with increased risk of colo-rectal cancer and recent advice is to reduce intakes to a maximum of 70 g/d. Such reductions in meat and haem-Fe intake are unlikely to influence Fe status in functional terms. However, overall protein intakes would probably fall, with the potential for intakes to be less than current requirements for the elderly. Whether it is detrimental to health is uncertain and controversial. Zn intakes are also likely to fall, raising questions about child growth that are currently unanswerable. Milk and dairy products, currently specifically recommended for young children and pregnant women, provide 30-40% of dietary Ca, iodine, vitamin B12 and riboflavin. Population groups with low milk intakes generally show low intakes and poor status for each of these nutrients. Taken together it would appear that the reductions in meat and dairy foods, which are necessary to limit environmental damage, do pose serious nutritional challenges for some key nutrients. These challenges can be met, however, by improved public health advice on alternative dietary sources and by increasing food fortification.

  18. Attractive scenario writing.

    PubMed

    Takahashi, Yuzo; Oku, Sachiko Alexandra

    2009-05-01

    This article describes the key steps of scenario writing to facilitate problem-based learning discussion to aid student learning of basic medical science in combination with clinical medicine. The scenario has to amplify and deepen the students' thinking so that they can correlate findings from the case and knowledge from textbooks. This can be achieved in three ways: (1) a comparison of cases; (2) demonstrating a scientific link between symptoms and basic medicine; and (3) introducing a personal and emotional aspect to the scenario. A comparison of two cases enables us to shed light on the pathological differences and think about the underlying biological mechanisms. These include: (a) a comparison of two cases with similar symptoms, but different diseases; (b) a comparison of two cases with different symptoms, but the same cause; and (c) a comparison of two cases, with an easy case, followed by a complicated case. The scenarios may be disclosed in a sequence to show a scientific link between symptoms of the patient and basic medicine, which may help to cultivate a physician with a scientific mind. Examples are given by the relationship between: (a) symptoms, pathology and morphology; and (b) symptoms, pathology and physiology. When the scenario is written in such a way that students are personally and/or emotionally involved in the case, they will be more motivated in learning as if involved in the case themselves. To facilitate this, the scenario can be written in the first-person perspective. Examples include "I had a very bad headache, and vomited several times...", and "I noticed that my father was screaming at night...". The description of the events may be in chronological order with actual time, which makes students feel as if they are really the primary responding person.

  19. The Effect of Natural Gas Supply on US Renewable Energy and Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Shearer, C.; Bistline, J.; Inman, M.; Davis, S. J.

    2014-12-01

    Increased use of natural gas has been promoted as a means of decarbonizing the US power sector, because of superior generator efficiency and lower CO2 emissions per unit of electricity than coal. We model the effect of different gas supplies on the US power sector and greenhouse gas (GHG) emissions. Across a range of climate policies, we find that more abundant natural gas decreases use of both coal and renewable energy technologies in the future. Without a climate policy, overall energy use also increases as the gas supply increases. With reduced deployment of lower-carbon renewable energies and increased electricity consumption, the effect of higher gas supplies on GHG emissions is small: cumulative emissions 2013-2055 in our high gas supply scenario are 2% less than in our low gas supply scenario, when there are no new climate policies and a methane leakage rate of 1.5% is assumed. Assuming leakage rates of 0 or 3% does not substantially alter this finding. In our results, only climate policies bring about a significant reduction in future CO2 emissions within the US electricity sector. Our results suggest that without strong limits on GHG emissions or policies that explicitly encourage renewable energy, more abundant natural gas may actually slow the process of decarbonization, primarily by delaying deployment of renewable energy technologies.

  20. New Method for Super Hydrophobic Treatment of Gas Diffusion Layers for Proton Exchange Membrane Fuel Cells Using Electrochemical Reduction of Diazonium Salts.

    PubMed

    Thomas, Yohann R J; Benayad, Anass; Schroder, Maxime; Morin, Arnaud; Pauchet, Joël

    2015-07-15

    The purpose of this article is to report a new method for the surface functionalization of commercially available gas diffusion layers (GDLs) by the electrochemical reduction of diazonium salt containing hydrophobic functional groups. The method results in superhydrophobic GDLs, over a large area, without pore blocking. An X-ray photoelectron spectroscopy study based on core level spectra and chemical mapping has demonstrated the successful grafting route, resulting in a homogeneous distribution of the covalently bonded hydrophobic molecules on the surface of the GDL fibers. The result was corroborated by contact angle measurement, showing similar hydrophobicity between the grafted and PTFE-modified GDLs. The electrochemically modified GDLs were tested in proton exchange membrane fuel cells under automotive, wet, and dry conditions and demonstrated improved performance over traditional GDLs.

  1. Arctic shipping emissions inventories and future scenarios

    NASA Astrophysics Data System (ADS)

    Corbett, J. J.; Lack, D. A.; Winebrake, J. J.; Harder, S.; Silberman, J. A.; Gold, M.

    2010-10-01

    This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050) scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow), aerosols, and gaseous emissions including carbon dioxide. We quantify ship emissions scenarios which are expected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. A first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase global warming potential due to Arctic ships' CO2 emissions (~42 000 gigagrams) by some 17% to 78%. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  2. Identifying sensitive sources and key control handles for the reduction of greenhouse gas emissions from wastewater treatment.

    PubMed

    Sweetapple, Christine; Fu, Guangtao; Butler, David

    2014-10-01

    This research investigates the effects of adjusting control handle values on greenhouse gas emissions from wastewater treatment, and reveals critical control handles and sensitive emission sources for control through the combined use of local and global sensitivity analysis methods. The direction of change in emissions, effluent quality and operational cost resulting from variation of control handles individually is determined using one-factor-at-a-time sensitivity analysis, and corresponding trade-offs are identified. The contribution of each control handle to variance in model outputs, taking into account the effects of interactions, is then explored using a variance-based sensitivity analysis method, i.e., Sobol's method, and significant second order interactions are discovered. This knowledge will assist future control strategy development and aid an efficient design and optimisation process, as it provides a better understanding of the effects of control handles on key performance indicators and identifies those for which dynamic control has the greatest potential benefits. Sources with the greatest variance in emissions, and therefore the greatest need to monitor, are also identified. It is found that variance in total emissions is predominantly due to changes in direct N2O emissions and selection of suitable values for wastage flow rate and aeration intensity in the final activated sludge reactor is of key importance. To improve effluent quality, costs and/or emissions, it is necessary to consider the effects of adjusting multiple control handles simultaneously and determine the optimum trade-off.

  3. (Per)chlorate reduction by the thermophilic bacterium Moorella perchloratireducens sp. nov., isolated from underground gas storage.

    PubMed

    Balk, Melike; van Gelder, Ton; Weelink, Sander A; Stams, Alfons J M

    2008-01-01

    A thermophilic bacterium, strain An10, was isolated from underground gas storage with methanol as a substrate and perchlorate as an electron acceptor. Cells were gram-positive straight rods, 0.4 to 0.6 mum in diameter and 2 to 8 mum in length, growing as single cells or in pairs. Spores were terminal with a bulged sporangium. The temperature range for growth was 40 to 70 degrees C, with an optimum at 55 to 60 degrees C. The pH optimum was around 7. The salinity range for growth was between 0 and 40 g NaCl liter(-1) with an optimum at 10 g liter(-1). Strain An10 was able to grow on CO, methanol, pyruvate, glucose, fructose, cellobiose, mannose, xylose, and pectin. The isolate was able to respire with (per)chlorate, nitrate, thiosulfate, neutralized Fe(III) complexes, and anthraquinone-2,6-disulfonate. The G+C content of the DNA was 57.6 mol%. On the basis of 16S rRNA analysis, strain An10 was most closely related to Moorella thermoacetica and Moorella thermoautotrophica. The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell extracts. Strain An10 is the first thermophilic and gram-positive bacterium with the ability to use (per)chlorate as a terminal electron acceptor.

  4. Accelerated reduction in SO₂ emissions from the U.S. power sector triggered by changing prices of natural gas.

    PubMed

    Lu, Xi; McElroy, Michael B; Wu, Gang; Nielsen, Chris P

    2012-07-17

    Emissions of sulfur dioxide (SO(2)) from the U.S. power sector decreased by 24% in 2009 relative to 2008. The Logarithmic Mean Divisia Index (LMDI) approach was applied to isolate the factors responsible for this decrease. It is concluded that 15% of the decrease can be attributed to the drop in demand for electricity triggered by the economic recession, and 28% can be attributed to switching of fuel from coal to gas responding to the decrease in prices for the latter. The largest factor in the decrease, close to 57%, resulted from an overall decline in emissions per unit of power generated from coal. This is attributed in part to selective idling of older, less efficient coal plants that generally do not incorporate technology for sulfur removal, and in part to continued investments by the power sector in removal equipment in response to the requirements limiting emissions imposed by the U.S. Environmental Protection Agency (U.S. EPA). The paper argues further that imposition of a modest tax on emissions of carbon would have ancillary benefits in terms of emissions of SO(2).

  5. Sustainability and energy development: influences of greenhouse gas emission reduction options on water use in energy production.

    PubMed

    Cooper, D Craig; Sehlke, Gerald

    2012-03-20

    Climate change mitigation strategies cannot be evaluated solely in terms of energy cost and greenhouse gas (GHG) mitigation potential. Maintaining GHGs at a "safe" level will require fundamental change in the way we approach energy production, and a number of environmental, economic, and societal factors will come into play. Water is an essential component of energy production, and water resource constraints will limit our options for meeting society's growing demand for energy while also reducing GHG emissions. This study evaluates these potential constraints from a global perspective by revisiting the climate wedges proposal of Pacala and Socolow (Science2004, 305 (5686), 968-972) and evaluating the potential water-use impacts of the wedges associated with energy production. GHG mitigation options that improve energy conversion or use efficiency can simultaneously reduce GHG emissions, lower energy costs, and reduce energy impacts on water resources. Other GHG mitigation options (e.g., carbon capture and sequestration, traditional nuclear, and biofuels from dedicated energy crops) increase water requirements for energy. Achieving energy sustainability requires deployment of alternatives that can reduce GHG emissions, water resource impacts, and energy costs.

  6. Biomass Scenario Model

    SciTech Connect

    2015-09-01

    The Biomass Scenario Model (BSM) is a unique, carefully validated, state-of-the-art dynamic model of the domestic biofuels supply chain which explicitly focuses on policy issues, their feasibility, and potential side effects. It integrates resource availability, physical/technological/economic constraints, behavior, and policy. The model uses a system dynamics simulation (not optimization) to model dynamic interactions across the supply chain.

  7. Mapping gas-phase organic reactivity and concomitant secondary organic aerosol formation: chemometric dimension reduction techniques for the deconvolution of complex atmospheric data sets

    NASA Astrophysics Data System (ADS)

    Wyche, K. P.; Monks, P. S.; Smallbone, K. L.; Hamilton, J. F.; Alfarra, M. R.; Rickard, A. R.; McFiggans, G. B.; Jenkin, M. E.; Bloss, W. J.; Ryan, A. C.; Hewitt, C. N.; MacKenzie, A. R.

    2015-07-01

    Highly non-linear dynamical systems, such as those found in atmospheric chemistry, necessitate hierarchical approaches to both experiment and modelling in order to ultimately identify and achieve fundamental process-understanding in the full open system. Atmospheric simulation chambers comprise an intermediate in complexity, between a classical laboratory experiment and the full, ambient system. As such, they can generate large volumes of difficult-to-interpret data. Here we describe and implement a chemometric dimension reduction methodology for the deconvolution and interpretation of complex gas- and particle-phase composition spectra. The methodology comprises principal component analysis (PCA), hierarchical cluster analysis (HCA) and positive least-squares discriminant analysis (PLS-DA). These methods are, for the first time, applied to simultaneous gas- and particle-phase composition data obtained from a comprehensive series of environmental simulation chamber experiments focused on biogenic volatile organic compound (BVOC) photooxidation and associated secondary organic aerosol (SOA) formation. We primarily investigated the biogenic SOA precursors isoprene, α-pinene, limonene, myrcene, linalool and β-caryophyllene. The chemometric analysis is used to classify the oxidation systems and resultant SOA according to the controlling chemistry and the products formed. Results show that "model" biogenic oxidative systems can be successfully separated and classified according to their oxidation products. Furthermore, a holistic view of results obtained across both the gas- and particle-phases shows the different SOA formation chemistry, initiating in the gas-phase, proceeding to govern the differences between the various BVOC SOA compositions. The results obtained are used to describe the particle composition in the context of the oxidised gas-phase matrix. An extension of the technique, which incorporates into the statistical models data from anthropogenic (i

  8. Mapping gas-phase organic reactivity and concomitant secondary organic aerosol formation: chemometric dimension reduction techniques for the deconvolution of complex atmospheric datasets

    NASA Astrophysics Data System (ADS)

    Wyche, K. P.; Monks, P. S.; Smallbone, K. L.; Hamilton, J. F.; Alfarra, M. R.; Rickard, A. R.; McFiggans, G. B.; Jenkin, M. E.; Bloss, W. J.; Ryan, A. C.; Hewitt, C. N.; MacKenzie, A. R.

    2015-01-01

    Highly non-linear dynamical systems, such as those found in atmospheric chemistry, necessitate hierarchical approaches to both experiment and modeling in order, ultimately, to identify and achieve fundamental process-understanding in the full open system. Atmospheric simulation chambers comprise an intermediate in complexity, between a classical laboratory experiment and the full, ambient system. As such, they can generate large volumes of difficult-to-interpret data. Here we describe and implement a chemometric dimension reduction methodology for the deconvolution and interpretation of complex gas- and particle-phase composition spectra. The methodology comprises principal component analysis (PCA), hierarchical cluster analysis (HCA) and positive least squares-discriminant analysis (PLS-DA). These methods are, for the first time, applied to simultaneous gas- and particle-phase composition data obtained from a comprehensive series of environmental simulation chamber experiments focused on biogenic volatile organic compound (BVOC) photooxidation and associated secondary organic aerosol (SOA) formation. We primarily investigated the biogenic SOA precursors isoprene, α-pinene, limonene, myrcene, linalool and β-caryophyllene. The chemometric analysis is used to classify the oxidation systems and resultant SOA according to the controlling chemistry and the products formed. Furthermore, a holistic view of results across both the gas- and particle-phases shows the different SOA formation chemistry, initiating in the gas-phase, proceeding to govern the differences between the various BVOC SOA compositions. The results obtained are used to describe the particle composition in the context of the oxidized gas-phase matrix. An extension of the technique, which incorporates into the statistical models data from anthropogenic (i.e. toluene) oxidation and "more realistic" plant mesocosm systems, demonstrates that such an ensemble of chemometric mapping has the potential to be

  9. International Experience with Key Program Elements of IndustrialEnergy Efficiency or Greenhouse Gas Emissions Reduction Target-SettingPrograms

    SciTech Connect

    Price, Lynn; Galitsky, Christina; Kramer, Klaas Jan

    2008-02-02

    Target-setting agreements, also known as voluntary ornegotiated agreements, have been used by a number of governments as amechanism for promoting energy efficiency within the industrial sector. Arecent survey of such target-setting agreement programs identified 23energy efficiency or GHG emissions reduction voluntary agreement programsin 18 countries. International best practice related to target-settingagreement programs calls for establishment of a coordinated set ofpolicies that provide strong economic incentives as well as technical andfinancial support to participating industries. The key program elementsof a target-setting program are the target-setting process,identification of energy-saving technologies and measures usingenergy-energy efficiency guidebooks and benchmarking as well as byconducting energy-efficiency audits, development of an energy-savingsaction plan, development and implementation of energy managementprotocols, development of incentives and supporting policies, monitoringprogress toward targets, and program evaluation. This report firstprovides a description of three key target-setting agreement programs andthen describes international experience with the key program elementsthat comprise such programs using information from the three keytarget-setting programs as well as from other international programsrelated to industrial energy efficiency or GHG emissionsreductions.

  10. Plasma Source Development for Effective Dissociation and Abatement of Perfluorinated Compounds for the Reduction of Gas Emissions

    NASA Astrophysics Data System (ADS)

    Mahoney, Leonard J.

    2001-10-01

    Perfluorinated gas compounds (PFCs) are widely used in the semiconductor industry for etching process and for cleaning of chemical vapor deposition (CVD) systems. However, most of these compounds have very high infrared adsorbance strengths and long life times (i.e. several times greater than carbon dioxide). Thus their emissions can strongly contribute to global warming if left unabated. To reduce PFC emissions, the industry has adopted high power density, sub-atmospheric plasma sources to completely dissociate F-bearing compounds at the point of use or to completely convert PFC emissions within the post process exhaust stream. Many electrodeless plasma sources have been applied including microwave, conventional inductive, and ferrite-based inductive plasma devices. As a general scaling rule, most all of these devices provide effective electric field strengths on the order 1-10 V/cm and power densities of 0.1-10 W/cm3 into electronegative discharges at pressures ranging from 0.1-100 Torr. To explore one contemporary example, we examine the properties a ferrite-based, inductively-coupled plasma source as applied to typical processes used in CVD chamber clean and PFC-based etching processes. Along with the operational properties of this device, we examine mass spectroscopy measurements of residual gases from the source when used to (1) fully dissociate high flows of pure NF3 and mixtures of C3F8/O2 and (2) abate moderate flows of CF4, C2F6 and SF6 in combination with O2 or H2O vapor. Also, we review select plasma engineering topics related to these PFC abatement approaches whose study would greatly advance the performance and cost effectiveness of plasma abatement technology within the industry.

  11. Nitrate reduction

    DOEpatents

    Dziewinski, Jacek J.; Marczak, Stanislaw

    2000-01-01

    Nitrates are reduced to nitrogen gas by contacting the nitrates with a metal to reduce the nitrates to nitrites which are then contacted with an amide to produce nitrogen and carbon dioxide or acid anions which can be released to the atmosphere. Minor amounts of metal catalysts can be useful in the reduction of the nitrates to nitrites. Metal salts which are formed can be treated electrochemically to recover the metals.

  12. Simulating post-wildfire forest trajectories under alternative climate and management scenarios

    NASA Astrophysics Data System (ADS)

    Azpeleta, Alicia; Fule, Peter; Shive, Kristen; Sieg, Carolyn; Sanchez-Meador, Andrew; Strom, Barbara

    2013-04-01

    To assess post-fire vegetation recovery under the influence of climate change, we applied the Climate-Forest Vegetation Simulator (Climate-FVS), a new version of a widely used forest management model, to compare alternative climate and management scenarios in a severely burned multi-species forest of Arizona, U.S.A. The incorporation of seven combinations of General Circulation Models (GCM) and emissions scenarios altered long-term (100 years) projections of future forest condition compared to a No Climate Change (NCC) scenario, which forecast a gradual increase to high levels of forest density and carbon storage. In contrast, emissions scenarios that included continued high greenhouse gas releases led to near-complete deforestation by 2111. GCM-emissions scenario combinations that were less severe reduced forest structure and carbon storage relative to NCC. Fuel reduction treatments that had been applied prior to the severe wildfire did have persistent effects, especially under NCC, but were overwhelmed by increasingly severe climate change. We tested six management strategies aimed at sustaining future forests: prescribed burning at 5, 10, or 20-year intervals, thinning 40% or 60% of stand basal area, and no-treatment. Severe climate change led to deforestation under all management regimes, but important differences emerged under the moderate scenarios: treatments that included regular prescribed burning fostered low density, wildfire-resistant forests composed of the naturally dominant species, ponderosa pine. Non-fire treatments under moderate climate change were forecast to become dense and susceptible to severe wildfire, with a shift to dominance by sprouting species. Current U.S.A. management requires modeling of future scenarios but does not mandate consideration of climate change effects. However, this study showed substantial differences in model outputs depending on climate and management actions. Managers should incorporate climate change into the

  13. Transportation Energy Futures Series: Alternative Fuel Infrastructure Expansion: Costs, Resources, Production Capacity, and Retail Availability for Low-Carbon Scenarios

    SciTech Connect

    Melaina, W.; Heath, Garvin; Sandor, Debra; Steward, Darlene; Vimmerstedt, Laura; Warner, Ethan; Webster, Karen W.

    2013-04-01

    The petroleum-based transportation fuel system is complex and highly developed, in contrast to the nascent low-petroleum, low-carbon alternative fuel system. This report examines how expansion of the low-carbon transportation fuel infrastructure could contribute to deep reductions in petroleum use and greenhouse gas (GHG) emissions across the U.S. transportation sector. Three low-carbon scenarios, each using a different combination of low-carbon fuels, were developed to explore infrastructure expansion trends consistent with a study goal of reducing transportation sector GHG emissions to 80% less than 2005 levels by 2050.These scenarios were compared to a business-as-usual (BAU) scenario and were evaluated with respect to four criteria: fuel cost estimates, resource availability, fuel production capacity expansion, and retail infrastructure expansion.

  14. Sequential quantification of methyl mercury in biological materials by selective reduction in the presence of mercury(II), using two gas liquid separators

    NASA Astrophysics Data System (ADS)

    Monteiro, Alcicléa da Conceição Pereira; de Andrade, Ly Santabaia N.; Luna, Aderval S.; de Campos, Reinaldo Calixto

    2002-12-01

    The present procedure is based on the sequential selective reduction of mercury(II) and methyl mercury using two gas-liquid separators in series. Cold vapor atomic absorption spectrometry was used for detection. Mercury(II) is reduced by a 0.01% m/v sodium tetrahydroborate solution and driven to the absorption cell in the first separator. The methyl mercury species is reduced by the same reductant but at a 0.3% m/v concentration, and in the presence of iron(III) chloride. Parameters such as argon flow rate, and the NaBH 4 and dithiophosphoric acid diacyl ester concentrations were optimized. At the optimized conditions, and using aqueous standards for calibration, the corresponding limits of detection (3σ b, n=10) were 400 and 600 ng l -1 for mercury(II) and methyl mercury, respectively. The sample throughput was 12 h -1. The procedure was used for the determination of methyl mercury in dogfish liver and dogfish muscle certified reference materials, and good concordance between found and certified values was observed.

  15. Computer program of data reduction procedures for facilities using CO2-N2-O2-Ar equilibrium real-gas mixtures

    NASA Technical Reports Server (NTRS)

    Miller, C. G., III

    1972-01-01

    Data reduction procedures for determining free-stream and post-normal-shock flow conditions are presented. These procedures are applicable to flows of CO2, N2, O2, Ar, or mixtures of these gases and include the effects of dissociation and ionization. The assumption of thermochemical equilibrium free-stream and post-normal-shock flow is made. Although derived primarily to meet the immediate needs of an expansion tube of a hot gas radiation research facility, these procedures are applicable to any supersonic or hypersonic test facility using these gases or mixtures thereof. The data reduction procedures are based on combinations of three of the following flow parameters measured in the immediate vicinity of the test section: (1) stagnation pressure behind normal shock, (2) free-stream static pressure, (3) stagnation-point heat-transfer rate, (4) free-stream velocity, and (5) free-stream density. Thus, these procedures do not depend explicitly upon measured or calculated upstream flow parameters. The procedures are incorporated into a single computer program written in FORTRAN IV language. A listing of this computer program is presented, along with a description of the inputs required and a sample of the data printout.

  16. Scenarios of global mercury emissions from anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Rafaj, P.; Bertok, I.; Cofala, J.; Schöpp, W.

    2013-11-01

    This paper discusses the impact of air quality and climate policies on global mercury emissions in the time horizon up to 2050. Evolution of mercury emissions is based on projections of energy consumption for a scenario without any global greenhouse gas mitigation efforts, and for a 2 °C climate policy scenario, which assumes internationally coordinated action to mitigate climate change. The assessment takes into account current air quality legislation in each country, as well as provides estimates of maximum feasible reductions in mercury through 2050. Results indicate significant scope for co-benefits of climate policies for mercury emissions. Atmospheric releases of mercury from anthropogenic sources under the global climate mitigation regime are reduced in 2050 by 45% when compared to the case without climate measures. Around one third of world-wide co-benefits for mercury emissions by 2050 occur in China. An annual Hg-abatement of about 800 tons is estimated for the coal combustion in power sector if the current air pollution legislation and climate policies are adopted in parallel.

  17. Greenhouse gas reduction by recovery and utilization of landfill methane and CO{sub 2} technical and market feasibility study, Boului Landfill, Bucharest, Romania. Final report, September 30, 1997--September 19, 1998

    SciTech Connect

    Cook, W.J.; Brown, W.R.; Siwajek, L.; Sanders, W.I.; Botgros, I.

    1998-09-01

    The project is a landfill gas to energy project rated at about 4 megawatts (electric) at startup, increasing to 8 megawatts over time. The project site is Boului Landfill, near Bucharest, Romania. The project improves regional air quality, reduces emission of greenhouse gases, controls and utilizes landfill methane, and supplies electric power to the local grid. The technical and economic feasibility of pre-treating Boului landfill gas with Acrion`s new landfill gas cleanup technology prior to combustion for power production us attractive. Acrion`s gas treatment provides several benefits to the currently structured electric generation project: (1) increase energy density of landfill gas from about 500 Btu/ft{sup 3} to about 750 Btu/ft{sup 3}; (2) remove contaminants from landfill gas to prolong engine life and reduce maintenance;; (3) recover carbon dioxide from landfill gas for Romanian markets; and (4) reduce emission of greenhouse gases methane and carbon dioxide. Greenhouse gas emissions reduction attributable to successful implementation of the landfill gas to electric project, with commercial liquid CO{sub 2} recovery, is estimated to be 53 million metric tons of CO{sub 2} equivalent of its 15 year life.

  18. Reduction of Salmonella enterica on alfalfa seeds with acidic electrolyzed oxidizing water and enhanced uptake of acidic electrolyzed oxidizing water into seeds by gas exchange.

    PubMed

    Stan, Silvia D; Daeschel, Mark A

    2003-11-01

    Alfalfa sprouts have been implicated in several salmonellosis outbreaks in recent years. The disinfectant effects of acidic electrolyzed oxidizing (EO) water against Salmonella enterica both in an aqueous system and on artificially contaminated alfalfa seeds were determined. The optimum ratio of seeds to EO water was determined in order to maximize the antimicrobial effect of EO water. Seeds were combined with EO water at ratios (wt/vol) of 1:4, 1:10, 1:20, 1:40, and 1:100, and the characteristics of EO water (pH, oxidation reduction potential [ORP], and free chlorine concentration) were determined. When the ratio of seeds to EO water was increased from 1:4 to 1:100, the pH decreased from 3.82 to 2.63, while the ORP increased from +455 to +1,073 mV. EO water (with a pH of 2.54 to 2.38 and an ORP of +1,083 to +1,092 mV) exhibited strong potential for the inactivation of S. enterica in an aqueous system (producing a reduction of at least 6.6 log CFU/ml). Treatment of artificially contaminated alfalfa seeds with EO water at a seed-to-EO water ratio of 1:100 for 15 and 60 min significantly reduced Salmonella populations by 2.04 and 1.96 log CFU/g, respectively (P < 0.05), while a Butterfield's buffer wash decreased Salmonella populations by 0.18 and 0.23 log CFU/g, respectively. After treatment, EO water was Salmonella negative by enrichment with or without neutralization. Germination of seeds was not significantly affected (P > 0.05) by treatment for up to 60 min in electrolyzed water. The uptake of liquid into the seeds was influenced by the internal gas composition (air, N2, or O2) of seeds before the liquid was added.

  19. Perceptions of Health Co-Benefits in Relation to Greenhouse Gas Emission Reductions: A Survey among Urban Residents in Three Chinese Cities

    PubMed Central

    Gao, Jinghong; Xu, Guozhang; Ma, Wenjun; Zhang, Yong; Woodward, Alistair; Vardoulakis, Sotiris; Kovats, Sari; Wilkinson, Paul; He, Tianfeng; Lin, Hualiang; Liu, Tao; Gu, Shaohua; Wang, Jun; Li, Jing; Yang, Jun; Liu, Xiaobo; Li, Jing; Wu, Haixia; Liu, Qiyong

    2017-01-01

    Limited information is available on the perceptions of stakeholders concerning the health co-benefits of greenhouse gas (GHG) emission reductions. The purpose of this study was to investigate the perceptions of urban residents on the health co-benefits involving GHG abatement and related influencing factors in three cities in China. Beijing, Ningbo and Guangzhou were selected for this survey. Participants were recruited from randomly chosen committees, following quotas for gender and age in proportion to the respective population shares. Chi-square or Fisher’s exact tests were employed to examine the associations between socio-demographic variables and individuals’ perceptions of the health co-benefits related to GHG mitigation. Unconditional logistic regression analysis was performed to investigate the influencing factors of respondents’ awareness about the health co-benefits. A total of 1159 participants were included in the final analysis, of which 15.9% reported that they were familiar with the health co-benefits of GHG emission reductions. Those who were younger, more educated, with higher family income, and with registered urban residence, were more likely to be aware of health co-benefits. Age, attitudes toward air pollution and governmental efforts to improve air quality, suffering from respiratory diseases, and following low carbon lifestyles are significant predictors of respondents’ perceptions on the health co-benefits. These findings may not only provide information to policy-makers to develop and implement public welcome policies of GHG mitigation, but also help to bridge the gap between GHG mitigation measures and public engagement as well as willingness to change health-related behaviors. PMID:28335404

  20. Perceptions of Health Co-Benefits in Relation to Greenhouse Gas Emission Reductions: A Survey among Urban Residents in Three Chinese Cities.

    PubMed

    Gao, Jinghong; Xu, Guozhang; Ma, Wenjun; Zhang, Yong; Woodward, Alistair; Vardoulakis, Sotiris; Kovats, Sari; Wilkinson, Paul; He, Tianfeng; Lin, Hualiang; Liu, Tao; Gu, Shaohua; Wang, Jun; Li, Jing; Yang, Jun; Liu, Xiaobo; Li, Jing; Wu, Haixia; Liu, Qiyong

    2017-03-13

    Limited information is available on the perceptions of stakeholders concerning the health co-benefits of greenhouse gas (GHG) emission reductions. The purpose of this study was to investigate the perceptions of urban residents on the health co-benefits involving GHG abatement and related influencing factors in three cities in China. Beijing, Ningbo and Guangzhou were selected for this survey. Participants were recruited from randomly chosen committees, following quotas for gender and age in proportion to the respective population shares. Chi-square or Fisher's exact tests were employed to examine the associations between socio-demographic variables and individuals' perceptions of the health co-benefits related to GHG mitigation. Unconditional logistic regression analysis was performed to investigate the influencing factors of respondents' awareness about the health co-benefits. A total of 1159 participants were included in the final analysis, of which 15.9% reported that they were familiar with the health co-benefits of GHG emission reductions. Those who were younger, more educated, with higher family income, and with registered urban residence, were more likely to be aware of health co-benefits. Age, attitudes toward air pollution and governmental efforts to improve air quality, suffering from respiratory diseases, and following low carbon lifestyles are significant predictors of respondents' perceptions on the health co-benefits. These findings may not only provide information to policy-makers to develop and implement public welcome policies of GHG mitigation, but also help to bridge the gap between GHG mitigation measures and public engagement as well as willingness to change health-related behaviors.

  1. Evolving practices in environmental scenarios: a new scenario typology

    NASA Astrophysics Data System (ADS)

    Wilkinson, Angela; Eidinow, Esther

    2008-10-01

    A new approach to scenarios focused on environmental concerns, changes and challenges, i.e. so-called 'environmental scenarios', is necessary if global environmental changes are to be more effectively appreciated and addressed through sustained and collaborative action. On the basis of a comparison of previous approaches to global environmental scenarios and a review of existing scenario typologies, we propose a new scenario typology to help guide scenario-based interventions. This typology makes explicit the types of and/or the approaches to knowledge ('the epistemologies') which underpin a scenario approach. Drawing on previous environmental scenario projects, we distinguish and describe two main types in this new typology: 'problem-focused' and 'actor-centric'. This leads in turn to our suggestion for a third type, which we call 'RIMA'—'reflexive interventionist or multi-agent based'. This approach to scenarios emphasizes the importance of the involvement of different epistemologies in a scenario-based process of action learning in the public interest. We suggest that, by combining the epistemologies apparent in the previous two types, this approach can create a more effective bridge between longer-term thinking and more immediate actions. Our description is aimed at scenario practitioners in general, as well as those who work with (environmental) scenarios that address global challenges.

  2. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by- product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, June 11, 1992--September 11, 1992

    SciTech Connect

    Sublette, K.L.

    1992-12-31

    Based on the work described simultaneous SO{sub 2}/No{sub x} removal from flue gas based on direct contact of the gas with SRB and T. denitrificans co-cultures or cultures-in-series has been eliminated as a viable process concept at this time. The technical reasons are as follows: (1) NO inhibition of SO{sub 2} reduction by D. desulfuricans - Although the NO concentrations used in the experiments described above are somewhat higher than that found in a typical flue gas, it is quite possible that at lower NO concentrations (or partial pressures) the inhibiting effects will simply take longer to become apparent. (2) Nitrate suppression of NO removal - As noted previously, the cultivation of T. denitrificans in a microbial flue gas treatment system (either one or two stages) would require sulfide-limiting conditions. Therefore, the electron acceptor must be in excess, requiring nitrate in the T. denitrificans process culture. As shown in experiments described above, nitrate significantly suppresses the removal of NO from a feed gas making simultaneous SO{sub 2}/NO{sub x} removal impractical by microbial means. (3) O{sub 2} inhibition of SO{sub 2} and NO reduction - It has been demonstrated that D. desulfuricans working cultures are tolerant of up to 1.7% O{sub 2} in the feed gas. However, further increases in the O{sub 2} partial pressure in the feed gas resulted in O{sub 2} inhibition of SO{sub 2} reduction. These inhibiting levels of O{sub 2} are comparable to those concentrations found in flue gases (3). Therefore, in any process in which raw flue gas contacts a D. desulfuricans culture marginal stability at best can be expected.

  3. Microbial reduction of SO[sub 2] and NO[sub x] as a means of by- product recovery/disposal from regenerable processes for the desulfurization of flue gas

    SciTech Connect

    Sublette, K.L.

    1992-01-01

    Based on the work described simultaneous SO[sub 2]/No[sub x] removal from flue gas based on direct contact of the gas with SRB and T. denitrificans co-cultures or cultures-in-series has been eliminated as a viable process concept at this time. The technical reasons are as follows: (1) NO inhibition of SO[sub 2] reduction by D. desulfuricans - Although the NO concentrations used in the experiments described above are somewhat higher than that found in a typical flue gas, it is quite possible that at lower NO concentrations (or partial pressures) the inhibiting effects will simply take longer to become apparent. (2) Nitrate suppression of NO removal - As noted previously, the cultivation of T. denitrificans in a microbial flue gas treatment system (either one or two stages) would require sulfide-limiting conditions. Therefore, the electron acceptor must be in excess, requiring nitrate in the T. denitrificans process culture. As shown in experiments described above, nitrate significantly suppresses the removal of NO from a feed gas making simultaneous SO[sub 2]/NO[sub x] removal impractical by microbial means. (3) O[sub 2] inhibition of SO[sub 2] and NO reduction - It has been demonstrated that D. desulfuricans working cultures are tolerant of up to 1.7% O[sub 2] in the feed gas. However, further increases in the O[sub 2] partial pressure in the feed gas resulted in O[sub 2] inhibition of SO[sub 2] reduction. These inhibiting levels of O[sub 2] are comparable to those concentrations found in flue gases (3). Therefore, in any process in which raw flue gas contacts a D. desulfuricans culture marginal stability at best can be expected.

  4. Electron Transfer Reduction of the Diazirine Ring in Gas-Phase Peptide Ions. On the Peculiar Loss of [NH4O] from Photoleucine

    NASA Astrophysics Data System (ADS)

    Marek, Aleš; Shaffer, Christopher J.; Pepin, Robert; Slováková, Kristina; Laszlo, Kenneth J.; Bush, Matthew F.; Tureček, František

    2015-03-01

    Electron transfer to gas-phase peptide ions with diazirine-containing amino acid residue photoleucine (L*) triggers diazirine ring reduction followed by cascades of residue-specific radical reactions. Upon electron transfer, substantial fractions of (GL*GGR +2H)+● cation-radicals undergo elimination of [NH4O] radicals and N2H2 molecules from the side chain. The side-chain dissociations are particularly prominent on collisional activation of long-lived (GL*GGR +2H)+● cation-radicals formed by electron transfer dissociation of noncovalent peptide-18-crown-6-ether ion complexes. The ion dissociation products were characterized by multistage tandem mass spectrometry (MSn) and ion mobility measurements. The elimination of [NH4O] was elucidated with the help of 2H, 15 N, and 18O-labeled peptide ions and found to specifically involve the amide oxygen of the N-terminal residue. The structures, energies, and electronic states of the peptide radical species were elucidated by a combination of near-UV photodissociation experiments and electron structure calculations combining ab initio and density functional theory methods. Electron transfer reaching the ground electronic states of charge reduced (GL*GGR +2H)+● cation-radicals was found to reduce the diazirine ring. In contrast, backbone N - Cα bond dissociations that represent a 60%-75% majority of all dissociations because of electron transfer are predicted to occur from excited electronic states.

  5. Gas entrapment and microbial N2O reduction reduce N2O emissions from a biochar-amended sandy clay loam soil

    PubMed Central

    Harter, Johannes; Guzman-Bustamante, Ivan; Kuehfuss, Stefanie; Ruser, Reiner; Well, Reinhard; Spott, Oliver; Kappler, Andreas; Behrens, Sebastian

    2016-01-01

    Nitrous oxide (N2O) is a potent greenhouse gas that is produced during microbial nitrogen transformation processes such as nitrification and denitrification. Soils represent the largest sources of N2O emissions with nitrogen fertilizer application being the main driver of rising atmospheric N2O concentrations. Soil biochar amendment has been proposed as a promising tool to mitigate N2O emissions from soils. However, the underlying processes that cause N2O emission suppression in biochar-amended soils are still poorly understood. We set up microcosm experiments with fertilized, wet soil in which we used 15N tracing techniques and quantitative polymerase chain reaction (qPCR) to investigate the impact of biochar on mineral and gaseous nitrogen dynamics and denitrification-specific functional marker gene abundance and expression. In accordance with previous studies our results showed that biochar addition can lead to a significant decrease in N2O emissions. Furthermore, we determined significantly higher quantities of soil-entrapped N2O and N2 in biochar microcosms and a biochar-induced increase in typical and atypical nosZ transcript copy numbers. Our findings suggest that biochar-induced N2O emission mitigation is based on the entrapment of N2O in water-saturated pores of the soil matrix and concurrent stimulation of microbial N2O reduction resulting in an overall decrease of the N2O/(N2O + N2) ratio. PMID:28008997

  6. Gas entrapment and microbial N2O reduction reduce N2O emissions from a biochar-amended sandy clay loam soil

    NASA Astrophysics Data System (ADS)

    Harter, Johannes; Guzman-Bustamante, Ivan; Kuehfuss, Stefanie; Ruser, Reiner; Well, Reinhard; Spott, Oliver; Kappler, Andreas; Behrens, Sebastian

    2016-12-01

    Nitrous oxide (N2O) is a potent greenhouse gas that is produced during microbial nitrogen transformation processes such as nitrification and denitrification. Soils represent the largest sources of N2O emissions with nitrogen fertilizer application being the main driver of rising atmospheric N2O concentrations. Soil biochar amendment has been proposed as a promising tool to mitigate N2O emissions from soils. However, the underlying processes that cause N2O emission suppression in biochar-amended soils are still poorly understood. We set up microcosm experiments with fertilized, wet soil in which we used 15N tracing techniques and quantitative polymerase chain reaction (qPCR) to investigate the impact of biochar on mineral and gaseous nitrogen dynamics and denitrification-specific functional marker gene abundance and expression. In accordance with previous studies our results showed that biochar addition can lead to a significant decrease in N2O emissions. Furthermore, we determined significantly higher quantities of soil-entrapped N2O and N2 in biochar microcosms and a biochar-induced increase in typical and atypical nosZ transcript copy numbers. Our findings suggest that biochar-induced N2O emission mitigation is based on the entrapment of N2O in water-saturated pores of the soil matrix and concurrent stimulation of microbial N2O reduction resulting in an overall decrease of the N2O/(N2O + N2) ratio.

  7. Reductant injection and mixing system

    SciTech Connect

    Reeves, Matt; Henry, Cary A.; Ruth, Michael J.

    2016-02-16

    A gaseous reductant injection and mixing system is described herein. The system includes an injector for injecting a gaseous reductant into an exhaust gas stream, and a mixer attached to a surface of the injector. The injector includes a plurality of apertures through which the gaseous reductant is injected into an exhaust gas stream. The mixer includes a plurality of fluid deflecting elements.

  8. Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

    SciTech Connect

    Inman, D.; Vimmerstedt, L.; Bush, B.; Peterson, S.

    2014-04-01

    Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

  9. Long-term projections and acclimatization scenarios of temperature-related mortality in Europe.

    PubMed

    Ballester, Joan; Robine, Jean-Marie; Herrmann, François Richard; Rodó, Xavier

    2011-06-21

    The steady increase in greenhouse gas concentrations is inducing a detectable rise in global temperatures. The sensitivity of human societies to warming temperatures is, however, a transcendental question not comprehensively addressed to date. Here we show the link between temperature, humidity and daily numbers of deaths in nearly 200 European regions, which are subsequently used to infer transient projections of mortality under state-of-the-art high-resolution greenhouse gas scenario simulations. Our analyses point to a change in the seasonality of mortality, with maximum monthly incidence progressively shifting from winter to summer. The results also show that the rise in heat-related mortality will start to completely compensate the reduction of deaths from cold during the second half of the century, amounting to an average drop in human lifespan of up 3-4 months in 2070-2100. Nevertheless, projections suggest that human lifespan might indeed increase if a substantial degree of adaptation to warm temperatures takes place.

  10. Repository preclosure accident scenarios

    SciTech Connect

    Yook, H.R.; Arbital, J.G.; Keeton, J.M.; Mosier, J.E.; Weaver, B.S.

    1984-09-01

    Waste-handling operations at a spent-fuel repository were investigated to identify operational accidents that could occur. The facility was subdivided, through systems engineering procedures, into individual operations that involve the waste and one specific component of the waste package, in one specific area of the handling facility. From this subdivision approximately 600 potential accidents involving waste package components were identified and then discussed. Supporting descriptive data included for each accident scenario are distance of drop, speed of collision, weight of package component, and weight of equipment involved. The energy of impact associated with each potential accident is calculated to provide a basis for comparison of the relative severities of all the accidents. The results and conclusions suggest approaches to accident consequence mitigation through waste package and facility design. 35 figures, 9 tables.

  11. USGS Multi-Hazards Winter Storm Scenario

    NASA Astrophysics Data System (ADS)

    Cox, D. A.; Jones, L. M.; Perry, S. C.

    2008-12-01

    The USGS began an inter-disciplinary effort, the Multi Hazards Demonstration Project (MHDP), in 2007 to demonstrate how hazards science can improve a community's resiliency to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages the user community in setting research goals and directs efforts towards research products that can be applied to loss reduction and improved resiliency. The first public product of the MHDP was the ShakeOut Earthquake Scenario published in May 2008. It detailed the realistic outcomes of a hypothetical, but plausible, magnitude 7.8 earthquake on the San Andreas Fault in southern California. Over 300 scientist and experts contributed to designing the earthquake and understanding the impacts of such a disaster, including the geotechnical, engineering, social, cultural, environmental, and economic consequences. The scenario advanced scientific understanding and exposed numerous vulnerabilities related to emergency response and lifeline continuity management. The ShakeOut Scenario was the centerpiece of the Nation's largest-ever emergency response exercise in November 2008, dubbed "The Great Southern California ShakeOut" (www.shakeout.org). USGS Multi-Hazards is now preparing for its next major public project, a Winter Storm Scenario. Like the earthquake scenario, experts will be brought together to examine in detail the possibility, cost and consequences of a winter storm disaster including floods, landslides, coastal erosion and inundation; debris flows; biologic consequences like extirpation of endangered species; physical damages like bridge scour, road closures, dam failure, property loss, and water system collapse. Consideration will be given to the vulnerabilities associated with a catastrophic disruption to the water supply to southern California; the resulting impacts on ground water pumping, seawater intrusion, water supply degradation, and land subsidence; and a

  12. Considering the Role of Natural Gas in the Deep Decarbonization of the U.S. Electricity Sector. Natural Gas and the Evolving U.S. Power Sector Monograph Series: Number 2

    SciTech Connect

    Cole, Wesley; Beppler, Ross; Zinaman, Owen; Logan, Jeffrey

    2016-02-12

    Natural gas generation in the U.S. electricity sector has grown substantially in recent years, while the sector's carbon dioxide (CO2) emissions have generally declined. This relationship highlights the concept of natural gas as a potential enabler of a transition to a lower-carbon future. This work considers that concept by using the National Renewable Energy Laboratory (NREL) Renewable Energy Deployment System (ReEDS) model. ReEDS is a long-term capacity expansion model of the U.S. electricity sector. We examine the role of natural gas within the ReEDS modeling framework as increasingly strict carbon emission targets are imposed on the electricity sector. In addition to various natural gas price futures, we also consider scenarios that emphasize a low-carbon technology in order to better understand the role of natural gas if that low-carbon technology shows particular promise. Specifically, we consider scenarios with high amounts of energy efficiency (EE), low nuclear power costs, low renewable energy (RE) costs, and low carbon capture and storage (CCS) costs. Within these scenarios we find that requiring the electricity sector to lower CO2 emissions over time increases near-to-mid-term (through 2030) natural gas generation (see Figure 1 - left). The long-term (2050) role of natural gas generation in the electricity sector is dependent on the level of CO2 emission reduction required. Moderate reductions in long-term CO2 emissions have relatively little impact on long-term natural gas generation, while more stringent CO2 emission limits lower long-term natural gas generation (see Figure 1 - right). More stringent carbon targets also impact other generating technologies, with the scenarios considered here seeing significant decreases in coal generation, and new capacity of nuclear and renewable energy technologies over time. Figure 1 also demonstrates the role of natural gas in the context of scenarios where a specific low-carbon technology is advantaged. In 2030

  13. Emissions implications of future natural gas production and use in the U.S. and in the Rocky Mountain region.

    PubMed

    McLeod, Jeffrey D; Brinkman, Gregory L; Milford, Jana B

    2014-11-18

    Enhanced prospects for natural gas production raise questions about the balance of impacts on air quality, as increased emissions from production activities are considered alongside the reductions expected when natural gas is burned in place of other fossil fuels. This study explores how trends in natural gas production over the coming decades might affect emissions of greenhouse gases (GHG), volatile organic compounds (VOCs) and nitrogen oxides (NOx) for the United States and its Rocky Mountain region. The MARKAL (MARKet ALlocation) energy system optimization model is used with the U.S. Environmental Protection Agency's nine-region database to compare scenarios for natural gas supply and demand, constraints on the electricity generation mix, and GHG emissions fees. Through 2050, total energy system GHG emissions show little response to natural gas supply assumptions, due to offsetting changes across sectors. Policy-driven constraints or emissions fees are needed to achieve net reductions. In most scenarios, wind is a less expensive source of new electricity supplies in the Rocky Mountain region than natural gas. U.S. NOx emissions decline in all the scenarios considered. Increased VOC emissions from natural gas production offset part of the anticipated reductions from the transportation sector, especially in the Rocky Mountain region.

  14. Quantifying N2O reduction to N2 based on N2O isotopocules - validation with independent methods (helium incubation and 15N gas flux method)

    NASA Astrophysics Data System (ADS)

    Lewicka-Szczebak, Dominika; Augustin, Jürgen; Giesemann, Anette; Well, Reinhard

    2017-02-01

    Stable isotopic analyses of soil-emitted N2O (δ15Nbulk, δ18O and δ15Nsp = 15N site preference within the linear N2O molecule) may help to quantify N2O reduction to N2, an important but rarely quantified process in the soil nitrogen cycle. The N2O residual fraction (remaining unreduced N2O, rN2O) can be theoretically calculated from the measured isotopic enrichment of the residual N2O. However, various N2O-producing pathways may also influence the N2O isotopic signatures, and hence complicate the application of this isotopic fractionation approach. Here this approach was tested based on laboratory soil incubations with two different soil types, applying two reference methods for quantification of rN2O: helium incubation with direct measurement of N2 flux and the 15N gas flux method. This allowed a comparison of the measured rN2O values with the ones calculated based on isotopic enrichment of residual N2O. The results indicate that the performance of the N2O isotopic fractionation approach is related to the accompanying N2O and N2 source processes and the most critical is the determination of the initial isotopic signature of N2O before reduction (δ0). We show that δ0 can be well determined experimentally if stable in time and then successfully applied for determination of rN2O based on δ15Nsp values. Much more problematic to deal with are temporal changes of δ0 values leading to failure of the approach based on δ15Nsp values only. For this case, we propose here a dual N2O isotopocule mapping approach, where calculations are based on the relation between δ18O and δ15Nsp values. This allows for the simultaneous estimation of the N2O-producing pathways' contribution and the rN2O value.

  15. Mission Scenario Development Workbench

    NASA Technical Reports Server (NTRS)

    Kordon, Mark; Baker, John; Gilbert, John; Hanks, David; Mandutianu, Dan; Hooper, David

    2006-01-01

    The Mission Scenario Development Workbench (MSDW) is a multidisciplinary performance analysis software tool for planning and optimizing space missions. It provides a number of new capabilities that are particularly useful for planning the surface activities on other planets. MSDW enables rapid planning of a space mission and supports flight system and scientific-instrumentation trades. It also provides an estimate of the ability of flight, ground, and science systems to meet high-level mission goals and provides means of evaluating expected mission performance at an early stage of planning in the project life cycle. In MSDW, activity plans and equipment-list spreadsheets are integrated with validated parameterized simulation models of spacecraft systems. In contrast to traditional approaches involving worst-case estimates with large margins, the approach embodied in MSDW affords more flexibility and more credible results early in the lifecycle through the use of validated, variable- fidelity models of spacecraft systems. MSDW is expected to help maximize the scientific return on investment for space missions by understanding early the performance required to have a successful mission while reducing the risk of costly design changes made at late stages in the project life cycle.

  16. Arctic shipping emissions inventories and future scenarios

    NASA Astrophysics Data System (ADS)

    Corbett, J. J.; Lack, D. A.; Winebrake, J. J.; Harder, S.; Silberman, J. A.; Gold, M.

    2010-04-01

    The Arctic is a sensitive region in terms of climate change and a rich natural resource for global economic activity. Arctic shipping is an important contributor to the region's anthropogenic air emissions, including black carbon - a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow. These emissions are projected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. To understand the impacts of these increased emissions, scientists and modelers require high-resolution, geospatial emissions inventories that can be used for regional assessment modeling. This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050) scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. Short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing; a first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing due to Arctic ships by at least 17% compared to warming from these vessels' CO2 emissions (~42 000 gigagrams). The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  17. Hydrological Sensitivity of Land Use Scenarios for Climate Mitigation

    NASA Astrophysics Data System (ADS)

    Boegh, E.; Friborg, T.; Hansen, K.; Jensen, R.; Seaby, L. P.

    2014-12-01

    Bringing atmospheric concentration to 550 ppm CO2 or below by 2100 will require large-scale changes to global and national energy systems, and potentially the use of land (IPCC, 2013) The Danish government aims at reducing greenhouse gas emissions (GHG) by 40 % in 1990-2020 and energy consumption to be based on 100 % renewable energy by 2035. By 2050, GHG emissions should be reduced by 80-95 %. Strategies developed to reach these goals require land use change to increase the production of biomass for bioenergy, further use of catch crops, reduced nitrogen inputs in agriculture, reduced soil tillage, afforestation and establishment of permanent grass fields. Currently, solar radiation in the growing season is not fully exploited, and it is expected that biomass production for bioenergy can be supported without reductions in food and fodder production. Impacts of climate change on the hydrological sensitivity of biomass growth and soil carbon storage are however not known. The present study evaluates the hydrological sensitivity of Danish land use options for climate mitigation in terms of crop yields (including straw for bioenergy) and net CO2 exchange for wheat, barley, maize and clover under current and future climate conditions. Hydrological sensitivity was evaluated using the agrohydrological model Daisy. Simulations during current climate conditions were in good agreement with measured dry matter, crop nitrogen content and eddy covariance fluxes of water vapour and CO2. Climate scenarios from the European ENSEMBLES database were downscaled for simulating water, nitrogen and carbon balance for 2071-2100. The biomass potential generally increase, but water stress also increases in strength and extends over a longer period, thereby increasing sensitivity to water availability. The potential of different land use scenarios to maximize vegetation cover and biomass for climate mitigation is further discussed in relation to impacts on the energy- and water balance.

  18. Generating moment matching scenarios using optimization techniques

    SciTech Connect

    Mehrotra, Sanjay; Papp, Dávid

    2013-05-16

    An optimization based method is proposed to generate moment matching scenarios for numerical integration and its use in stochastic programming. The main advantage of the method is its flexibility: it can generate scenarios matching any prescribed set of moments of the underlying distribution rather than matching all moments up to a certain order, and the distribution can be defined over an arbitrary set. This allows for a reduction in the number of scenarios and allows the scenarios to be better tailored to the problem at hand. The method is based on a semi-infinite linear programming formulation of the problem that is shown to be solvable with polynomial iteration complexity. A practical column generation method is implemented. The column generation subproblems are polynomial optimization problems; however, they need not be solved to optimality. It is found that the columns in the column generation approach can be efficiently generated by random sampling. The number of scenarios generated matches a lower bound of Tchakaloff's. The rate of convergence of the approximation error is established for continuous integrands, and an improved bound is given for smooth integrands. Extensive numerical experiments are presented in which variants of the proposed method are compared to Monte Carlo and quasi-Monte Carlo methods on both numerical integration problems and stochastic optimization problems. The benefits of being able to match any prescribed set of moments, rather than all moments up to a certain order, is also demonstrated using optimization problems with 100-dimensional random vectors. Here, empirical results show that the proposed approach outperforms Monte Carlo and quasi-Monte Carlo based approaches on the tested problems.

  19. Generating moment matching scenarios using optimization techniques

    DOE PAGES

    Mehrotra, Sanjay; Papp, Dávid

    2013-05-16

    An optimization based method is proposed to generate moment matching scenarios for numerical integration and its use in stochastic programming. The main advantage of the method is its flexibility: it can generate scenarios matching any prescribed set of moments of the underlying distribution rather than matching all moments up to a certain order, and the distribution can be defined over an arbitrary set. This allows for a reduction in the number of scenarios and allows the scenarios to be better tailored to the problem at hand. The method is based on a semi-infinite linear programming formulation of the problem thatmore » is shown to be solvable with polynomial iteration complexity. A practical column generation method is implemented. The column generation subproblems are polynomial optimization problems; however, they need not be solved to optimality. It is found that the columns in the column generation approach can be efficiently generated by random sampling. The number of scenarios generated matches a lower bound of Tchakaloff's. The rate of convergence of the approximation error is established for continuous integrands, and an improved bound is given for smooth integrands. Extensive numerical experiments are presented in which variants of the proposed method are compared to Monte Carlo and quasi-Monte Carlo methods on both numerical integration problems and stochastic optimization problems. The benefits of being able to match any prescribed set of moments, rather than all moments up to a certain order, is also demonstrated using optimization problems with 100-dimensional random vectors. Here, empirical results show that the proposed approach outperforms Monte Carlo and quasi-Monte Carlo based approaches on the tested problems.« less

  20. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, March 11, 1993--June 11, 1993

    SciTech Connect

    Sublette, K.L.

    1993-11-01

    There are two basic approaches to addressing the problem of SO{sub 2} and NO{sub x} emissions: (1) desulfurize (and denitrogenate) the feedstock prior to or during combustion; or (2) scrub the resultant SO{sub 2} and oxides of nitrogen from the boiler flue gases. The flue gas processing alternative has been addressed in this project via microbial reduction of SO{sub 2} and NO{sub x} by sulfate-reducing bacteria

  1. Scenarios Based on Shared Socioeconomic Pathway Assumptions

    NASA Astrophysics Data System (ADS)

    Edmonds, J.

    2013-12-01

    A set of new scenarios is being developed by the international scientific community as part of a larger program that was articulated in Moss, et al. (2009), published in Nature. A long series of meetings including climate researchers drawn from the climate modeling, impacts, adaptation and vulnerability (IAV) and integrated assessment modeling (IAM) communities have led to the development of a set of five Shared Socioeconomic Pathways (SSPs), which define the state of human and natural societies at a macro scale over the course of the 21st century without regard to climate mitigation or change. SSPs were designed to explore a range of possible futures consistent with greater or lesser challenges to mitigation and challenges to adaptation. They include a narrative storyline and a set of quantified measures--e.g. demographic and economic profiles--that define the high-level state of society as it evolves over the 21st century under the assumption of no significant climate feedback. SSPs can be used to develop quantitative scenarios of human Earth systems using IAMs. IAMs produce information about greenhouse gas emissions, energy systems, the economy, agriculture and land use. Each set of SSPs will have a different human Earth system realization for each IAM. Five groups from the IAM community have begun to explore the implications of SSP assumptions for emissions, energy, economy, agriculture and land use. We report the quantitative results of initial experiments from those groups. A major goal of the Moss, et al. strategy was to enable the use of CMIP5 climate model ensemble products for IAV research. CMIP5 climate scenarios used four Representative Concentration Pathway (RCP) scenarios, defined in terms of radiative forcing in the year 2100: 2.6, 4.5, 6.0, and 8.5 Wm-2. There is no reason to believe that the SSPs will generate year 2100 levels of radiative forcing that correspond to the four RCP levels, though it is important that at least one SSP produce a

  2. Student Rights and Responsibilities Scenarios.

    ERIC Educational Resources Information Center

    Peterson, Ludwig A.; And Others

    To stimulate interest in student's rights and responsibilities, this resource contains incomplete scenarios dealing with the consequences of knowing and not knowing the law, as it is applied to modern practical situations. The scenarios can be used in high school courses such as government, social problems, history, psychology, and business law.…

  3. Futures Scenario in Science Learning

    ERIC Educational Resources Information Center

    Lloyd, David; Vanderhout, Annastasia; Lloyd, Lisa; Atkins, David

    2010-01-01

    In this article we describe our experiences in developing futures scenarios in two science contexts, space science and atmospheric science/climate change. Futures scenario writing can develop scientific literacy by connecting science learning to students' lifeworlds--past, present and future. They also provide a synthesising mechanism for…

  4. Role of the Freight Sector in Future Climate Change Mitigation Scenarios.

    PubMed

    Muratori, Matteo; Smith, Steven J; Kyle, Page; Link, Robert; Mignone, Bryan K; Kheshgi, Haroon S

    2017-03-21

    The freight sector's role is examined using the Global Change Assessment Model (GCAM) for a range of climate change mitigation scenarios and future freight demand assumptions. Energy usage and CO2 emissions from freight have historically grown with a correlation to GDP, and there is limited evidence of near-term global decoupling of freight demand from GDP. Over the 21(st) century, greenhouse gas (GHG) emissions from freight are projected to grow faster than passenger transportation or other major end-use sectors, with the magnitude of growth dependent on the assumed extent of long-term decoupling. In climate change mitigation scenarios that apply a price to GHG emissions, mitigation of freight emissions (including the effects of demand elasticity, mode and technology shifting, and fuel substitution) is more limited than for other demand sectors. In such scenarios, shifting to less-emitting transportation modes and technologies is projected to play a relatively small role in reducing freight emissions in GCAM. By contrast, changes in the supply chain of liquid fuels that reduce the fuel carbon intensity, especially deriving from large-scale use of biofuels coupled to carbon capture and storage technologies, are responsible for the majority of freight emissions mitigation, followed by price-induced reduction in freight demand services.

  5. Scenarios for Low Carbon and Low Water Electric Power Plant Operations: Implications for Upstream Water Use.

    PubMed

    Dodder, Rebecca S; Barnwell, Jessica T; Yelverton, William H

    2016-11-01

    Electric sector water use, in particular for thermoelectric operations, is a critical component of the water-energy nexus. On a life cycle basis per unit of electricity generated, operational (e.g., cooling system) water use is substantially higher than water demands for the fuel cycle (e.g., natural gas and coal) and power plant manufacturing (e.g., equipment and construction). However, could shifting toward low carbon and low water electric power operations create trade-offs across the electricity life cycle? We compare business-as-usual with scenarios of carbon reductions and water constraints using the MARKet ALlocation (MARKAL) energy system model. Our scenarios show that, for water withdrawals, the trade-offs are minimal: operational water use accounts for over 95% of life cycle withdrawals. For water consumption, however, this analysis identifies potential trade-offs under some scenarios. Nationally, water use for the fuel cycle and power plant manufacturing can reach up to 26% of the total life cycle consumption. In the western United States, nonoperational consumption can even exceed operational demands. In particular, water use for biomass feedstock irrigation and manufacturing/construction of solar power facilities could increase with high deployment. As the United States moves toward lower carbon electric power operations, consideration of shifting water demands can help avoid unintended consequences.

  6. Fertilizer Emission Scenario Tool for crop management system scenarios

    EPA Pesticide Factsheets

    The Fertilizer Emission Scenario Tool for CMAQ is a high-end computer interface that simulates daily fertilizer application information for any gridded domain. It integrates the Weather Research and Forecasting model and CMAQ.

  7. Renewable energy scenario in India: Opportunities and challenges

    NASA Astrophysics Data System (ADS)

    Sen, Souvik; Ganguly, Sourav; Das, Ayanangshu; Sen, Joyjeet; Dey, Sourav

    2016-10-01

    Majority of the power generation in India is carried out by conventional energy sources, coal and fossil fuels being the primary ones, which contribute heavily to greenhouse gas emission and global warming. The Indian power sector is witnessing a revolution as excitement grips the nation about harnessing electricity from various renewable energy sources. Electricity generation from renewable sources is increasingly recognized to play an important role for the achievement of a variety of primary and secondary energy policy goals, such as improved diversity and security of energy supply, reduction of local pollutant and global greenhouse gas emissions, regional and rural development, and exploitation of opportunities for fostering social cohesion, value addition and employment generation at the local and regional level. This focuses the solution of the energy crisis on judicious utilization of abundant the renewable energy resources, such as biomass, solar, wind, geothermal and ocean tidal energy. This paper reviews the renewable energy scenario of India as well as extrapolates the future developments keeping in view the consumption, production and supply of power. Research, development, production and demonstration have been carried out enthusiastically in India to find a feasible solution to the perennial problem of power shortage for the past three decades. India has obtained application of a variety of renewable energy technologies for use in different sectors too. There are ample opportunities with favorable geology and geography with huge customer base and widening gap between demand and supply. Technological advancement, suitable regulatory policies, tax rebates, efficiency improvement in consequence to R&D efforts are the few pathways to energy and environment conservation and it will ensure that these large, clean resource bases are exploited as quickly and cost effectively as possible. This paper gives an overview of the potential renewable energy resources

  8. Data reduction analysis and application technique development for atmospheric trace gas constituents derived from remote sensors on satellite or airborne platforms

    NASA Technical Reports Server (NTRS)

    Casas, J. C.; Campbell, S. A.

    1981-01-01

    The applicability of the gas filter correlation radiometer (GFCR) to the measurement of tropospheric carbon monoxide gas was investigated. An assessment of the GFRC measurement system to a regional measurement program was conducted through extensive aircraft flight-testing of several versions of the GFRC. Investigative work in the following areas is described: flight test planning and coordination, acquisition of verifying CO measurements, determination and acquisition of supporting meteorological data requirements, and development of supporting computational software.

  9. Environmental implications of United States coal exports: a comparative life cycle assessment of future power system scenarios.

    PubMed

    Bohnengel, Barrett; Patiño-Echeverri, Dalia; Bergerson, Joule

    2014-08-19

    Stricter emissions requirements on coal-fired power plants together with low natural gas prices have contributed to a recent decline in the use of coal for electricity generation in the United States. Faced with a shrinking domestic market, many coal companies are taking advantage of a growing coal export market. As a result, U.S. coal exports hit an all-time high in 2012, fueled largely by demand in Asia. This paper presents a comparative life cycle assessment of two scenarios: a baseline scenario in which coal continues to be burned domestically for power generation, and an export scenario in which coal is exported to Asia. For the coal export scenario we focus on the Morrow Pacific export project being planned in Oregon by Ambre Energy that would ship 8.8 million tons of Powder River Basin (PRB) coal annually to Asian markets via rail, river barge, and ocean vessel. Air emissions (SOx, NOx, PM10 and CO2e) results assuming that the exported coal is burned for electricity generation in South Korea are compared to those of a business as usual case in which Oregon and Washington's coal plants, Boardman and Centralia, are retrofitted to comply with EPA emissions standards and continue their coal consumption. Findings show that although the environmental impacts of shipping PRB coal to Asia are significant, the combination of superior energy efficiency among newer South Korean coal-fired power plants and lower emissions from U.S. replacement of coal with natural gas could lead to a greenhouse gas reduction of 21% in the case that imported PRB coal replaces other coal sources in this Asian country. If instead PRB coal were to replace natural gas or nuclear generation in South Korea, greenhouse gas emissions per unit of electricity generated would increase. Results are similar for other air emissions such as SOx, NOx and PM. This study provides a framework for comparing energy export scenarios and highlights the importance of complete life cycle assessment in

  10. Alternative scenarios utilizing nonterrestrial resources

    NASA Technical Reports Server (NTRS)

    Eldred, Charles H.; Roberts, Barney B.

    1992-01-01

    A collection of alternative scenarios that are enabled or substantially enhanced by the utilization of nonterrestrial resources is provided. We take a generalized approach to scenario building so that our report will have value in the context of whatever goals are eventually chosen. Some of the topics covered include the following: lunar materials processing; asteroid mining; lunar resources; construction of a large solar power station; solar dynamic power for the space station; reduced gravity; mission characteristics and options; and tourism.

  11. Methods for Developing Emissions Scenarios for Integrated Assessment Models

    SciTech Connect

    Prinn, Ronald; Webster, Mort

    2007-08-20

    The overall objective of this research was to contribute data and methods to support the future development of new emissions scenarios for integrated assessment of climate change. Specifically, this research had two main objectives: 1. Use historical data on economic growth and energy efficiency changes, and develop probability density functions (PDFs) for the appropriate parameters for two or three commonly used integrated assessment models. 2. Using the parameter distributions developed through the first task and previous work, we will develop methods of designing multi-gas emission scenarios that usefully span the joint uncertainty space in a small number of scenarios. Results on the autonomous energy efficiency improvement (AEEI) parameter are summarized, an uncertainty analysis of elasticities of substitution is described, and the probabilistic emissions scenario approach is presented.

  12. Modeling framework for exploring emission impacts of alternative future scenarios

    NASA Astrophysics Data System (ADS)

    Loughlin, D. H.; Benjey, W. G.; Nolte, C. G.

    2010-11-01

    This article presents an approach for creating anthropogenic emission scenarios that can be used to simulate future regional air quality. The approach focuses on energy production and use since these are principal sources of air pollution. We use the MARKAL model to characterize alternative realizations of the US energy system through 2050. Emission growth factors are calculated for major energy system categories using MARKAL, while growth factors from non-energy sectors are based on economic and population projections. The SMOKE model uses these factors to grow a base-year 2002 inventory to future years through 2050. The approach is demonstrated for two emission scenarios: Scenario 1 extends current air regulations through 2050, while Scenario 2 applies a hypothetical policy that limits carbon dioxide (CO2) emissions from the energy system. Although both scenarios show significant reductions in air pollutant emissions through time, these reductions are more pronounced in Scenario 2, where the CO2 policy results in the adoption of technologies with lower emissions of both CO2 and traditional air pollutants. The methodology is expected to play an important role in investigations of linkages among emission drivers, climate and air quality by the U.S. EPA and others.

  13. Assessing global fossil fuel availability in a scenario framework

    SciTech Connect

    Bauer, Nico; Hilaire, Jérôme; Brecha, Robert J.; Edmonds, Jae; Jiang, Kejun; Kriegler, Elmar; Rogner, Hans-Holger; Sferra, Fabio

    2016-06-01

    This study assesses global, long-term economic availability of coal, oil and gas within the Shared Socio-economic Pathway (SSP) scenario framework considering alternative assumptions as to highly uncertain future developments of technology, policy and the economy. Diverse sets of trajectories are formulated varying the challenges to mitigation and adaptation of climate change. The potential CO2 emissions from fossil fuels make it a crucial element subject to deep uncertainties. The analysis is based on a well-established data set of cost-quantity combinations that assumes favorable techno-economic developments, but ignores additional constraints on the extraction sector. This study significantly extends that analysis to include alternative assumptions for the fossil fuel sector consistent with the SSP scenario families and applies these filters to the original data set, thus resulting in alternative cumulative fossil fuel availability curves. In a Middle-of-the-Road scenario, low cost fossil fuels embody carbon consistent with a RCP6.0 emission profile, if all the CO2 were emitted freely during the 21st century. In scenarios with high challenges to mitigation, the assumed embodied carbon in low-cost fossil fuels can trigger a RCP8.5 scenario; low mitigation challenges scenarios are still consistent with a RCP4.5 scenario.

  14. Earthquake resistant construction of gas and liquid fuel pipeline systems serving, or regulated by, the Federal government. Earthquake hazard reduction series No. 67

    SciTech Connect

    Yokel, F.Y.; Mathey, R.G.

    1992-07-01

    The vulnerability of gas and liquid fuel pipeline systems to damage in past earthquakes, as well as available standards and technologies that can protect these facilities against earthquake damage are reviewed. An overview is presented of measures taken by various Federal Agencies to protect pipeline systems under their jurisdiction against earthquake hazards. It is concluded that the overall performance of pipeline systems in past earthquakes was relatively good, however, older pipelines and above-ground storage tanks were damaged in many earthquakes. Standards and regulations for liquid fuel pipelines contain only general references to seismic loads. Standards and regulations for above-ground fuel storage tanks and for liquefied natural gas facilities contain explicit seismic design provisions. It is recommended that a guideline for earthquake resistant design of gas and liquid fuel pipeline systems be prepared for Federal Agencies to ensure a uniform approach to the protection of these systems.

  15. Development of Greenhouse Gas Mitigation Options for Alberta's Energy Sector

    NASA Astrophysics Data System (ADS)

    Subramanyam, Veena

    Alberta is the third largest economy in Canada and is expected to grow significantly in the coming decade. The energy sector plays a major role in Alberta's economy. The objective of this research is to develop various greenhouse gas (GHG) mitigations scenarios in the energy demand and supply sectors for the Province of Alberta. This is done through an energy-environment planning and forecasting tool called Long Range Energy Alternative Planning system model (LEAP). By using LEAP, a sankey diagram for energy and emission flows for the Province of Alberta has been developed. A reference case also called as business-as-usual scenario was developed for a study period of 25 years (2005-2030). The GHG mitigation scenarios encompassed various demand and supply side scenarios. In the energy conversion sector, mitigation scenarios for renewable power generation and inclusion of supercritical, ultra-supercritical and integrated gasification combined cycle (IGCC) plants were investigated. In the oil and gas sector, GHG mitigation scenarios with carbon capture and sequestration (CCS) option were considered. In Alberta's residential and commercial sector 4-6 MT of CO2 equivalents per year of GHG mitigation could be achieved with efficiency improvement. In the industrial sector up to 40 MT of CO2 equivalents per year of GHG reduction could be achieved with efficiency improvement. In the energy conversion sector large GHG mitigation potential lies in the oil and gas sector and also in power plants with carbon capture and storage (CCS) option. The total GHG mitigation possible in the supply side option is between 20--70 MT CO2 equivalents per year.

  16. Understanding the contribution of non-carbon dioxide gases in deep mitigation scenarios

    SciTech Connect

    Gernaat, David; Calvin, Katherine V.; Lucas, Paul; Luderer, Gunnar; Otto, Sander; Rao, Shilpa; Strefler, Jessica; Van Vuuren, Detlef

    2015-07-01

    The combined 2010 emissions of methane (CH4), nitrous oxide (N2O) and the fluorinated gasses (F-gas) account for about 20-30% of total emissions and about 30% of radiative forcing. At the moment, most studies looking at reaching ambitious climate targets project the emission of carbon dioxide (CO2) to be reduced to zero (or less) by the end of the century. As for non-CO2 gases, the mitigation potential seem to be more constrained, we find that by the end of the century in the current deep mitigation scenarios non-CO2 emissions could form the lion’s share of remaining greenhouse gas emissions. In order to support effective climate policy strategies, in this paper we provide a more in-depth look at the role of non-CO2¬ emission sources (CH4, N2O and F-gases) in achieving deep mitigation targets (radiative forcing target of 2.8 W/m2 in 2100). Specifically, we look at the sectorial mitigation potential and the remaining non-CO2 emissions. By including a set of different models, we provide some insights into the associated uncertainty. Most of the remaining methane emissions in 2100 in the climate mitigation scenario come from the livestock sector. Strong reductions are seen in the energy supply sector across all models. For N2O, less reduction potential is seen compared to methane and the sectoral differences are larger between the models. The paper shows that the assumptions on remaining non-CO2 emissions are critical for the feasibility of reaching ambitious climate targets and the associated costs.

  17. Polyethylene recycling: Waste policy scenario analysis for the EU-27.

    PubMed

    Andreoni, Valeria; Saveyn, Hans G M; Eder, Peter

    2015-08-01

    This paper quantifies the main impacts that the adoption of the best recycling practices together with a reduction in the consumption of single-use plastic bags and the adoption of a kerbside collection system could have on the 27 Member States of the EU. The main consequences in terms of employment, waste management costs, emissions and energy use have been quantified for two scenarios of polyethylene (PE) waste production and recycling. That is to say, a "business as usual scenario", where the 2012 performances of PE waste production and recycling are extrapolated to 2020, is compared to a "best practice scenario", where the best available recycling practices are modelled together with the possible adoption of the amended Packaging and Packaging Waste Directive related to the consumption of single-use plastic bags and the implementation of a kerbside collection system. The main results show that socio-economic and environmental benefits can be generated across the EU by the implementation of the best practice scenario. In particular, estimations show a possible reduction of 4.4 million tonnes of non-recycled PE waste, together with a reduction of around €90 million in waste management costs in 2020 for the best practice scenario versus the business as usual scenario. An additional 35,622 jobs are also expected to be created. In environmental terms, the quantity of CO2 equivalent emissions could be reduced by around 1.46 million tonnes and the net energy requirements are expected to increase by 16.5 million GJ as a consequence of the reduction in the energy produced from waste. The main analysis provided in this paper, together with the data and the model presented, can be useful to identify the possible costs and benefits that the implementation of PE waste policies and Directives could generate for the EU.

  18. High fidelity chemistry and radiation modeling for oxy -- combustion scenarios

    NASA Astrophysics Data System (ADS)

    Abdul Sater, Hassan A.

    To account for the thermal and chemical effects associated with the high CO2 concentrations in an oxy-combustion atmosphere, several refined gas-phase chemistry and radiative property models have been formulated for laminar to highly turbulent systems. This thesis examines the accuracies of several chemistry and radiative property models employed in computational fluid dynamic (CFD) simulations of laminar to transitional oxy-methane diffusion flames by comparing their predictions against experimental data. Literature review about chemistry and radiation modeling in oxy-combustion atmospheres considered turbulent systems where the predictions are impacted by the interplay and accuracies of the turbulence, radiation and chemistry models. Thus, by considering a laminar system we minimize the impact of turbulence and the uncertainties associated with turbulence models. In the first section of this thesis, an assessment and validation of gray and non-gray formulations of a recently proposed weighted-sum-of-gray gas model in oxy-combustion scenarios was undertaken. Predictions of gas, wall temperatures and flame lengths were in good agreement with experimental measurements. The temperature and flame length predictions were not sensitive to the radiative property model employed. However, there were significant variations between the gray and non-gray model radiant fraction predictions with the variations in general increasing with decrease in Reynolds numbers possibly attributed to shorter flames and steeper temperature gradients. The results of this section confirm that non-gray model predictions of radiative heat fluxes are more accurate than gray model predictions especially at steeper temperature gradients. In the second section, the accuracies of three gas-phase chemistry models were assessed by comparing their predictions against experimental measurements of temperature, species concentrations and flame lengths. The chemistry was modeled employing the Eddy

  19. Medical Scenarios Relevant to Spaceflight

    NASA Technical Reports Server (NTRS)

    Bacal, Kira; Hurs, Victor; Doerr, Harold

    2004-01-01

    The Medical Operational Support Team (MOST) was tasked by the JSC Space Medicine and Life Sciences Directorate (SLSD) to incorporate medical simulation into 1) medical training for astronaut-crew medical officers (CMO) and medical flight control teams and 2) evaluations of procedures and resources required for medical care aboard the International Space Station (ISS). Development of evidence-based medical scenarios that mimic the physiology observed during spaceflight will be needed for the MOST to complete these two tasks. The MOST used a human patient simulator, the ISS-like resources in the Medical Simulation Laboratory (MSL), and evidence from space operations, military operations and medical literature to develop space relevant medical scenarios. These scenarios include conditions concerning airway management, Advanced Cardiac Life Support (ACLS) and mitigating anaphylactic symptoms. The MOST has used these space relevant medical scenarios to develop a preliminary space medical training regimen for NASA flight surgeons, Biomedical Flight Controllers (Biomedical Engineers; BME) and CMO-analogs. This regimen is conducted by the MOST in the MSL. The MOST has the capability to develop evidence-based space-relevant medical scenarios that can help SLSD I) demonstrate the proficiency of medical flight control teams to mitigate space-relevant medical events and 2) validate nextgeneration medical equipment and procedures for space medicine applications.

  20. Evaluating the risk-reduction benefits of wind energy

    SciTech Connect

    Brower, M.C.; Bell, K.; Bernow, S.; Duckworth, M.; Spinney P.

    1996-12-31

    This paper presents preliminary results of a study to evaluate the risk-reduction benefits of wind power for a case study utility system using decision analysis techniques. The costs and risks of two alternative decisions-whether to build a 400 MW gas-fired combined cycle plant or a 1600 MW wind plant in 2003-were compared through computer simulations as fuel prices, environmental regulatory costs, wind and conventional power plant availability, and load growth were allowed to vary. Three different market scenarios were examined: traditional regulation, a short-term power pool, and fixed-price contracts of varying duration. The study concludes that, from the perspective of ratepayers, wind energy provides a net levelized risk-reduction benefit of $3.4 to $7.8/MWh under traditional regulation, and less in the other scenarios. From the perspective of the utility plant owners, wind provides a significant risk benefit in the unregulated market scenarios but none in a regulated market. The methodology and findings should help inform utility resource planning and industry restructuring efforts. 2 figs., 3 tabs.

  1. On strategies for reducing greenhouse gas emissions.

    PubMed

    Bolin, B; Kheshgi, H S

    2001-04-24

    Equity is of fundamental concern in the quest for international cooperation to stabilize greenhouse gas concentrations by the reduction of emissions. By modeling the carbon cycle, we estimate the global CO(2) emissions that would be required to stabilize the atmospheric concentration of CO(2) at levels ranging from 450 to 1,000 ppm. These are compared, on both an absolute and a per-capita basis, to scenarios for emissions from the developed and developing worlds generated by socio-economic models under the assumption that actions to mitigate greenhouse gas emissions are not taken. Need and equity have provided strong arguments for developing countries to request that the developed world takes the lead in controlling its emissions, while permitting the developing countries in the meantime to use primarily fossil fuels for their development. Even with major and early control of CO(2) emissions by the developed world, limiting concentration to 450 ppm implies that the developing world also would need to control its emissions within decades, given that we expect developing world emissions would otherwise double over this time. Scenarios leading to CO(2) concentrations of 550 ppm exhibit a reduction of the developed world's per-capita emission by about 50% over the next 50 years. Even for the higher stabilization levels considered, the developing world would not be able to use fossil fuels for their development in the manner that the developed world has used them.

  2. Haunted Quantum Entanglement: Two Scenarios

    NASA Astrophysics Data System (ADS)

    Snyder, Douglas

    2010-04-01

    Two haunted quantum entanglement scenarios are proposed that are very close to the haunted measurement scenario in that: 1) the entity that is developing as a which-way marker is effectively restored to its state prior to its being fixed as a w-w marker, and 2) the entity for which the developing w-w marker provides information is restored to its state before it interacted with the entity which subsequent to the interaction begins developing as a w-w marker. In the hqe scenarios, the loss of developing w-w information through 1 relies on the loss of a developing entanglement. In scenario 1, the photon initially emitted in one of two micromaser cavities and developing into a w-w marker is effectively lost through the injection of classical microwave radiation into both of the microwave cavities after the atom initially emits the photon into one of the micromaser cavities, exits the cavity system, and before this atom reaches the 2 slit screen. The atom is restored in both of the two new scenarios to its original state before it emitted a photon by an rf coil situated at the exit of the micromaser cavity system. In scenario 2, the cavity system and everything from the atom source forward to the cavity system is enclosed in an evacuated box. After the atom that emits the photon exits the cavity system and before it reaches the 2 slit screen, the cavity system opens (and the photon escapes in the evacuated box) and then the box is opened and the photon escapes into the environment.

  3. Gas-assisted growth of boron-doped nickel nanotube arrays: rapid synthesis, growth mechanisms, tunable magnetic properties, and super-efficient reduction of 4-nitrophenol.

    PubMed

    Li, Xiang-Zi; Wu, Kong-Lin; Ye, Yin; Wei, Xian-Wen

    2013-05-07

    Highly ordered noncrystalline boron-doped nickel nanotube arrays are rapidly synthesized within 150 s by template-based electroless deposition. The as-prepared nanotubes have tunable magnetic properties and exhibit super efficient catalytic activity (∼70 s) for the reduction of 4-nitrophenol.

  4. Underground infrastructure damage for a Chicago scenario

    SciTech Connect

    Dey, Thomas N; Bos, Rabdall J

    2011-01-25

    Estimating effects due to an urban IND (improvised nuclear device) on underground structures and underground utilities is a challenging task. Nuclear effects tests performed at the Nevada Test Site (NTS) during the era of nuclear weapons testing provides much information on how underground military structures respond. Transferring this knowledge to answer questions about the urban civilian environment is needed to help plan responses to IND scenarios. Explosions just above the ground surface can only couple a small fraction of the blast energy into an underground shock. The various forms of nuclear radiation have limited penetration into the ground. While the shock transmitted into the ground carries only a small fraction of the blast energy, peak stresses are generally higher and peak ground displacement is lower than in the air blast. While underground military structures are often designed to resist stresses substantially higher than due to the overlying rocks and soils (overburden), civilian structures such as subways and tunnels would generally only need to resist overburden conditions with a suitable safety factor. Just as we expect the buildings themselves to channel and shield air blast above ground, basements and other underground openings as well as changes of geology will channel and shield the underground shock wave. While a weaker shock is expected in an urban environment, small displacements on very close-by faults, and more likely, soils being displaced past building foundations where utility lines enter could readily damaged or disable these services. Immediately near an explosion, the blast can 'liquefy' a saturated soil creating a quicksand-like condition for a period of time. We extrapolate the nuclear effects experience to a Chicago-based scenario. We consider the TARP (Tunnel and Reservoir Project) and subway system and the underground lifeline (electric, gas, water, etc) system and provide guidance for planning this scenario.

  5. Climate-change scenario for the Columbia River basin. Forest Service research paper

    SciTech Connect

    Ferguson, S.A.

    1997-04-01

    This work describes the method used to generate a climate-change scenario for the Columbia River basin. The scenario considers climate patterns that may change if the atmospheric concentration of carbon dioxide (CO2), or its greenhouse gas equivalent, were to double over pre-Industrial Revolution values. A composite approach was taken to generate a climate scenario that considers knowledge of current regional climate controls, available output from general circulation and regional climate models, and observed changes in climate.

  6. Performance of gas turbines in Russia under the changing climatic conditions

    NASA Astrophysics Data System (ADS)

    Klimenko, V. V.; Klimenko, A. V.; Kasilova, E. V.; Rekunenko, E. S.; Tereshin, A. G.

    2016-10-01

    The impact of the expected climatic changes on the performance of gas turbine units (GTU) as part of the power industry and gas pipeline network in Russia is considered. Long-term estimates of changes in the average annual air temperature throughout the country are made based on the authors' model. The calculations using the efficiency value of gas turbine units as a function of the ambient air temperature show that climatic changes will significantly deteriorate the operational efficiency of gas-turbine equipment in practically all of Russia's regions. Based on publicly available statistical data, we assessed the installed capacity of gas-turbine power stations (including combined-cycle power plants) and gas-turbine drive of gas pipeline network. Three development scenarios have been considered for gas turbine power in the national electric power industry, differing in the rates of new facilities' commissioning. Integrated estimates have been made of the increase in gas consumption in Russia's gas pipeline network and power industry resulting from climatic changes by 2030 and 2050. It is shown that the total increase in the annual gas consumption associated with a reduction in the efficiency of gas turbine units due to climate warming by 2030 could reach approximately 130000 tce (of which approximately 90000 tce in the gas pipeline network and 40000 tce in the electric power industry) and more than 170000 tce (120000 and 50000 tce, respectively) by 2050. Should more optimistic scenarios be implemented for the development of the electric power industry, this effect will increase 1.5-2.0 times by 2050. Despite high absolute values, the increase in GTU fuel expenditures due to higher ambient temperatures resulting from climate change in Russia will only amount to a fraction of a percent of the total gas consumption and will be two orders of magnitude lower than the savings in space heating.

  7. The Rational Design of a Single-Component Photocatalyst for Gas-Phase CO2 Reduction Using Both UV and Visible Light.

    PubMed

    Hoch, Laura B; Wood, Thomas E; O'Brien, Paul G; Liao, Kristine; Reyes, Laura M; Mims, Charles A; Ozin, Geoffrey A

    2014-12-01

    The solar-to-chemical energy conversion of greenhouse gas CO2 into carbon-based fuels is a very important research challenge, with implications for both climate change and energy security. Herein, the key attributes of hydroxides and oxygen vacancies are experimentally identified in non-stoichiometric indium oxide nanoparticles, In2O3-x(OH)y, that function in concert to reduce CO2 to CO under simulated solar irradiation.

  8. Valve for gas centrifuges

    DOEpatents

    Hahs, C.A.; Rurbage, C.H.

    1982-03-17

    The invention is pneumatically operated valve assembly for simulatenously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two on the lines so closed. The value assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  9. Ultra-Perfect Sorting Scenarios

    NASA Astrophysics Data System (ADS)

    Ouangraoua, Aïda; Bergeron, Anne; Swenson, Krister M.

    Perfection has been used as a criteria to select rearrangement scenarios since 2004. However, there is a fundamental bias towards extant species in the original definition: ancestral species are not bound to perfection. Here we develop a new theory of perfection that takes an egalitarian view of species, and apply it to the complex evolution of mammal chromosome X.

  10. Future Scenarios and Environmental Education

    ERIC Educational Resources Information Center

    Kopnina, Helen

    2014-01-01

    This article explores a number of questions about visions of the future and their implications for environmental education (EE). If the future were known, what kind of actions would be needed to maintain the positive aspects and reverse the negative ones? How could these actions be translated into the aims of EE? Three future scenarios are…

  11. Space resources. Volume 1: Scenarios

    NASA Technical Reports Server (NTRS)

    Mckay, Mary Fae (Editor); Mckay, David S. (Editor); Duke, Michael B. (Editor)

    1992-01-01

    A number of possible future paths for space exploration and development are presented. The topics covered include the following: (1) the baseline program; (2) alternative scenarios utilizing nonterrestrial resources; (3) impacts of sociopolitical conditions; (4) common technologies; and issues for further study.

  12. Particle production in Ekpyrotic scenarios

    SciTech Connect

    Hipólito-Ricaldi, W.S.; Brandenberger, Robert; Ferreira, Elisa G.M.; Graef, L.L.

    2016-11-09

    We consider Parker particle production in the Ekpyrotic scenario (in particular in the New Ekpyrotic model) and show that the density of particles produced by the end of the phase of Ekpyrotic contraction can be sufficient to lead to a hot state of matter after the bounce. Hence, no separate reheating mechanism is necessary.

  13. Human Factor Investigation of Waste Processing System During the HI-SEAS 4 Month Mars Analog Mission in Support of NASA's Logistic Reduction and Repurposing Project: Trash to Gas

    NASA Technical Reports Server (NTRS)

    Caraccio, Anne; Hintze, Paul; Miles, John D.

    2014-01-01

    NASAs Logistics Reduction and Repurposing (LRR) project is a collaborative effort in which NASA is tasked with reducing total logistical mass through reduction, reuse and recycling of various wastes and components of long duration space missions and habitats. Trash to Gas (TtG) is a sub task to LRR with efforts focused on development of a technology that converts wastes generated during long duration space missions into high-value products such as methane, water for life support, raw material production feedstocks, and other energy sources. The reuse of discarded materials is a critical component to reducing overall mission mass. The 120 day Hawaii Space Exploration and Analog Simulation provides a unique opportunity to answer questions regarding crew interface and system analysis for designing and developing future flight-like versions of a TtG system. This paper will discuss the human factors that would affect the design of a TtG or other waste processing systems. An overview of the habitat, utility usage, and waste storage and generation is given. Crew time spent preparing trash for TtG processing was recorded. Gas concentrations were measured near the waste storage locations and at other locations in the habitat. In parallel with the analog mission, experimental processing of waste materials in a TtG reactor was performed in order to evaluate performance with realistic waste materials.

  14. Human Factor Investigation of Waste Processing System During the HI-SEAS 4-month Mars Analog Mission in Support of NASA's Logistic Reduction and Repurposing Project: Trash to Gas

    NASA Technical Reports Server (NTRS)

    Caraccio, Anne; Hintze, Paul E.; Miles, John D.

    2014-01-01

    NASA's Logistics Reduction and Repurposing (LRR) project is a collaborative effort in which NASA is tasked with reducing total logistical mass through reduction, reuse and recycling of various wastes and components of long duration space missions and habitats. Trash to Gas (TtG) is a sub task to LRR with efforts focused on development of a technology that converts wastes generated during long duration space missions into high-value products such as methane, water for life support, raw material production feedstocks, and other energy sources. The reuse of discarded materials is a critical component to reducing overall mission mass. The 120 day Hawaii Space Exploration and Analog Simulation provides a unique opportunity to answer questions regarding crew interface and system analysis for designing and developing future flight-like versions of a TtG system. This paper will discuss the human factors that would affect the design of a TtG or other waste processing systems. An overview of the habitat, utility usage, and waste storage and generation is given. Crew time spent preparing trash for TtG processing was recorded. Gas concentrations were measured near the waste storage locations and at other locations in the habitat. In parallel with the analog mission, experimental processing of waste materials in a TtG reactor was performed in order to evaluate performance with realistic waste materials.

  15. Revised scenario for human missions to Mars

    NASA Astrophysics Data System (ADS)

    Salotti, Jean Marc

    2012-12-01

    We present a revised version of our scenario for human missions to Mars. The idea is to take into consideration the difficulties and constraints for entry, descent and landing by splitting the heavy vehicle into two smaller ones. The standard capsule shape is thus possible for aerocapture and landing on Mars. It is suggested to use the largest possible diameter such that the ballistic coefficient is minimized and the lift to drag ratio is kept small. The maneuvers for the descent and landing are then simplified and the risks are minimized. The scenario has been modified to cope with the new constraints. Different options have been taken into account. It is possible to land a small Mars ascent vehicle or to reuse the habitat lander for Mars ascent. All options perform as well as the others for the criterion of the initial mass in low Earth orbit. However, reusing the habitat lander allows a significant reduction of the size of the Earth return vehicle, which otherwise requires a huge launching capability.

  16. The Asymptotic Safety Scenario in Quantum Gravity.

    PubMed

    Niedermaier, Max; Reuter, Martin

    2006-01-01

    The asymptotic safety scenario in quantum gravity is reviewed, according to which a renormalizable quantum theory of the gravitational field is feasible which reconciles asymptotically safe couplings with unitarity. The evidence from symmetry truncations and from the truncated flow of the effective average action is presented in detail. A dimensional reduction phenomenon for the residual interactions in the extreme ultraviolet links both results. For practical reasons the background effective action is used as the central object in the quantum theory. In terms of it criteria for a continuum limit are formulated and the notion of a background geometry self-consistently determined by the quantum dynamics is presented. Self-contained appendices provide prerequisites on the background effective action, the effective average action, and their respective renormalization flows.

  17. Comparing the greenhouse gas emissions from three alternative waste combustion concepts.

    PubMed

    Vainikka, Pasi; Tsupari, Eemeli; Sipilä, Kai; Hupa, Mikko

    2012-03-01

    Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO(2)-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

  18. Risk reduction in road and rail LPG transportation by passive fire protection.

    PubMed

    Paltrinieri, Nicola; Landucci, Gabriele; Molag, Menso; Bonvicini, Sarah; Spadoni, Gigliola; Cozzani, Valerio

    2009-08-15

    The potential reduction of risk in LPG (Liquefied Petroleum Gas) road transport due to the adoption of passive fire protections was investigated. Experimental data available for small scale vessels fully engulfed by a fire were extended to real scale road and rail tankers through a finite elements model. The results of mathematical simulations of real scale fire engulfment scenarios that may follow accidents involving LPG tankers proved the effectiveness of the thermal protections in preventing the "fired" BLEVE (Boiling Liquid Expanding Vapour Explosion) scenario. The presence of a thermal coating greatly increases the "time to failure", providing a time lapse that in the European experience may be considered sufficient to allow the start of effective mitigation actions by fire brigades. The results obtained were used to calculate the expected reduction of individual and societal risk due to LPG transportation in real case scenarios. The analysis confirmed that the introduction of passive fire protections turns out in a significant reduction of risk, up to an order of magnitude in the case of individual risk and of about 50% if the expectation value is considered. Thus, the adoption of passive fire protections, not compulsory in European regulations, may be an effective technical measure for risk reduction, and may contribute to achieve the control of "major accidents hazards" cited by the European legislation.

  19. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, September 11, 1992--December 11, 1992

    SciTech Connect

    Sublette, K.L.

    1992-12-31

    With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans and have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.

  20. Addressing an Uncertain Future Using Scenario Analysis

    SciTech Connect

    Siddiqui, Afzal S.; Marnay, Chris

    2006-12-15

    The Office of Energy Efficiency and Renewable Energy (EERE) has had a longstanding goal of introducing uncertainty into the analysis it routinely conducts in compliance with the Government Performance and Results Act (GPRA) and for strategic management purposes. The need to introduce some treatment of uncertainty arises both because it would be good general management practice, and because intuitively many of the technologies under development by EERE have a considerable advantage in an uncertain world. For example, an expected kWh output from a wind generator in a future year, which is not exposed to volatile and unpredictable fuel prices, should be truly worth more than an equivalent kWh from an alternative fossil fuel fired technology. Indeed, analysts have attempted to measure this value by comparing the prices observed in fixed-price natural gas contracts compared to ones in which buyers are exposed to market prices (see Bolinger, Wiser, and Golove and (2004)). In addition to the routine reasons for exploring uncertainty given above, the history of energy markets appears to have exhibited infrequent, but troubling, regime shifts, i.e., historic turning points at which the center of gravity or fundamental nature of the system appears to have abruptly shifted. Figure 1 below shows an estimate of how the history of natural gas fired generating costs has evolved over the last three decades. The costs shown incorporate both the well-head gas price and an estimate of how improving generation technology has gradually tended to lower costs. The purpose of this paper is to explore scenario analysis as a method for introducing uncertainty into EERE's forecasting in a manner consistent with the preceding observation. The two questions are how could it be done, and what is its academic basis, if any. Despite the interest in uncertainty methods, applying them poses some major hurdles because of the heavy reliance of EERE on forecasting tools that are deterministic in

  1. Exploring NASA Human Spaceflight and Pioneering Scenarios

    NASA Technical Reports Server (NTRS)

    Zapata, Edgar; Wilhite, Alan

    2015-01-01

    The life cycle cost analysis of space exploration scenarios is explored via a merger of (1) scenario planning, separating context and (2) modeling and analysis of specific content. Numerous scenarios are presented, leading to cross-cutting recommendations addressing life cycle costs, productivity, and approaches applicable to any scenarios. Approaches address technical and non-technical factors.

  2. North American Natural Gas Markets

    SciTech Connect

    Not Available

    1988-12-01

    This report sunnnarizes the research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group's findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models.

  3. Coal to gas substitution using coal?!

    NASA Astrophysics Data System (ADS)

    Kempka, Thomas; Schlüter, Ralph

    2010-05-01

    Substitution of carbon-intensive coal with less carbon-intensive natural gas for energy production is discussed as one main pillar targeting reduction of antrophogenic greenhouse gas emissions by means of climate change mitigation. Other pillars are energy efficiency, renewable energies, carbon capture and storage as well as further development of nuclear energy. Taking into account innovative clean coal technologies such as UCG-CCS (underground coal gasification with carbon capture and storage), in which coal deposits are developed using directional drilling technologies and subsequently converted into a synthesis gas of high calorific value, the coupled conceptual approach can provide a synergetic technology for coal utilization and mitigation of carbon emissions. This study aims at the evaluation of UCǴ s carbon mitigation potentials and the review of the economical boundary conditions. The analytical models applied within this study are based on data available from world-wide UCG projects and extensive laboratory studies. In summary, scenarios considering costs and carbon storage potentials are economically feasible and thus competitive with less carbon-intensive energy generation technologies such as natural gas. Thus, coal to gas substitution can be one of the coal based options.

  4. Gas intrusion into SPR caverns

    SciTech Connect

    Hinkebein, T.E.; Bauer, S.J.; Ehgartner, B.L.; Linn, J.K.; Neal, J.T.; Todd, J.L.; Kuhlman, P.S.; Gniady, C.T.; Giles, H.N.

    1995-12-01

    The conditions and occurrence of gas in crude oil stored in Strategic Petroleum Reserve, SPR, caverns is characterized in this report. Many caverns in the SPR show that gas has intruded into the oil from the surrounding salt dome. Historical evidence and the analyses presented here suggest that gas will continue to intrude into many SPR caverns in the future. In considering why only some caverns contain gas, it is concluded that the naturally occurring spatial variability in salt permeability can explain the range of gas content measured in SPR caverns. Further, it is not possible to make a one-to-one correlation between specific geologic phenomena and the occurrence of gas in salt caverns. However, gas is concluded to be petrogenic in origin. Consequently, attempts have been made to associate the occurrence of gas with salt inhomogeneities including anomalies and other structural features. Two scenarios for actual gas intrusion into caverns were investigated for consistency with existing information. These scenarios are gas release during leaching and gas permeation through salt. Of these mechanisms, the greater consistency comes from the belief that gas permeates to caverns through the salt. A review of historical operating data for five Bryan Mound caverns loosely supports the hypothesis that higher operating pressures reduce gas intrusion into caverns. This conclusion supports a permeability intrusion mechanism. Further, it provides justification for operating the caverns near maximum operating pressure to minimize gas intrusion. Historical gas intrusion rates and estimates of future gas intrusion are given for all caverns.

  5. Chlorine dioxide gas from an aqueous solution: reduction of Salmonella in wounds on tomato fruit and movement to sinks in a treatment chamber.

    PubMed

    Mahovic, Michael; Bartz, Jerry A; Schneider, Keith R; Tenney, Joel D

    2009-05-01

    Chlorine dioxide (ClO2) off-gassed from an aqueous solution and reacted incrementally with potassium iodide solutions (sinks). After 30 min, 45% of the initial dose was detected as chlorite ion in the sink, whereas 35% of the initial dose was still in the source. Aqueous solutions of ClO2 can be used as a source of ClO2 gas in various laboratory experiments involving treatment of fruits or vegetables. Movement from source to sink is continuous, which precludes the development of large headspace concentrations and the need for a tight chamber seal. When the source solution has dissipated, the chamber can be opened safely as there is little free ClO2 remaining in the headspace. In tests with whole, wound-inoculated tomato fruit, at both green and pink stages of ripeness, the control of Salmonella enterica serotype Typhimurium in wounds varied with the weight of gas used. The number of viable cells of Typhimurium recovered was reduced by > 5 log units when > or = 0.5 mg of ClO2 was applied to three pieces of fruit during a 2-h treatment.

  6. Problem of intensity reduction of acoustic fields generated by gas-dynamic jets of motors of the rocket-launch vehicles at launch

    NASA Astrophysics Data System (ADS)

    Vorobyov, A. M.; Abdurashidov, T. O.; Bakulev, V. L.; But, A. B.; Kuznetsov, A. B.; Makaveev, A. T.

    2015-04-01

    The present work experimentally investigates suppression of acoustic fields generated by supersonic jets of the rocket-launch vehicles at the initial period of launch by water injection. Water jets are injected to the combined jet along its perimeter at an angle of 0° and 60°. The solid rocket motor with the rocket-launch vehicles simulator case is used at tests. Effectiveness of reduction of acoustic loads on the rocket-launch vehicles surface by way of creation of water barrier was proved. It was determined that injection angle of 60° has greater effectiveness to reduce pressure pulsation levels.

  7. Health in the New Scenarios for Climate Change Research

    PubMed Central

    Ebi, Kristie L.

    2013-01-01

    The climate change research community is developing a toolkit for creating new scenarios to explore and evaluate the extensive uncertainties associated with future climate change and development pathways. Components of the toolkit include pathways for greenhouse gas emissions over this century and their associated magnitude and pattern of climate change; descriptions of a range of possible socioeconomic development pathways, including qualitative narratives and quantitative elements; and climate change policies to achieve specific levels of radiative forcing and levels of adaptive capacity. These components are combined within a matrix architecture to create a scenario. Five reference socioeconomic development pathways have been described along axes describing increasing socioeconomic and environmental challenges to adaptation and to mitigation. This paper extends these global pathways to describe their possible consequences for public health and health care, and considers the additional elements that could be added to increase the relevance of the new scenarios to address a wider range of policy relevant questions than previously possible. PMID:24452253

  8. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection.

    PubMed

    Barber, Larry B; Hladik, Michelle L; Vajda, Alan M; Fitzgerald, Kevin C; Douville, Chris

    2015-10-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m(3) d(-1) design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration=2.7 μg L(-1); n=5) and 10 HDBPs (mean total concentration=4.5 μg L(-1)), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration=1.4 μg L(-1)) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative proportions of

  9. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection

    USGS Publications Warehouse

    Barber, Larry B.; Hladik, Michelle; Vajda, Alan M.; Fitzgerald, Kevin C.; Douville, Chris

    2015-01-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m3 d−1 design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration = 2.7 μg L−1; n=5) and 10 HDBPs (mean total concentration = 4.5 μg L−1), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration = 1.4 μg L−1) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative

  10. On the origin of asteroids. [early solar system scenario

    NASA Technical Reports Server (NTRS)

    Cameron, A. G. W.

    1979-01-01

    A general scenario is described for the early history of the solar system. The primitive solar nebula is formed from the infall of gas from a collapsing interstellar cloud fragment. It becomes repeatedly unstable against collapse to form giant gaseous protoplanets. In the course of protoplanet evolution the center of the protoplanet enters a thermodynamic regime in which common rocky minerals become liquids; convection brings solids to the central region where a substantial fraction of them rain out to form a protoplanetary core. In the inner solar system protoplanetary envelopes are tidally stripped away, thus injecting into the solar nebula large equantities of chondrules and inclusions. Late in the development of the solar nebula, after most of the gas has disappeared, turbulence dies out and the small solids settle into a thin layer at midplane of the nebula. Gravitational instabilities in this layer form asteroidal and cometary bodies. Some further consequences of this scenario are discussed.

  11. Acetone butanol ethanol (ABE) production from concentrated substrate: reduction in substrate inhibition by fed-batch technique and product inhibition by gas stripping.

    PubMed

    Ezeji, T C; Qureshi, N; Blaschek, H P

    2004-02-01

    Acetone butanol ethanol (ABE) was produced in an integrated fed-batch fermentation-gas stripping product-recovery system using Clostridium beijerinckii BA101, with H(2) and CO(2) as the carrier gases. This technique was applied in order to eliminate the substrate and product inhibition that normally restricts ABE production and sugar utilization to less than 20 g l(-1) and 60 g l(-1), respectively. In the integrated fed-batch fermentation and product recovery system, solvent productivities were improved to 400% of the control batch fermentation productivities. In a control batch reactor, the culture used 45.4 g glucose l(-1) and produced 17.6 g total solvents l(-1) (yield 0.39 g g(-1), productivity 0.29 g l(-1) h(-1)). Using the integrated fermentation-gas stripping product-recovery system with CO(2) and H(2) as carrier gases, we carried out fed-batch fermentation experiments and measured various characteristics of the fermentation, including ABE production, selectivity, yield and productivity. The fed-batch reactor was operated for 201 h. At the end of the fermentation, an unusually high concentration of total acids (8.5 g l(-1)) was observed. A total of 500 g glucose was used to produce 232.8 g solvents (77.7 g acetone, 151.7 g butanol, 3.4 g ethanol) in 1 l culture broth. The average solvent yield and productivity were 0.47 g g(-1) and 1.16 g l(-1) h(-1), respectively.

  12. Designing Asteroid Impact Scenario Trajectories

    NASA Astrophysics Data System (ADS)

    Chodas, Paul

    2016-05-01

    In order to study some of the technical and geopolitical issues of dealing with an asteroid on impact trajectory, a number of hypothetical impact scenarios have been presented over the last ten years or so. These have been used, for example, at several of the Planetary Defense Conferences (PDCs), as well as in tabletop exercises with the Federal Emergency Management Agency (FEMA), along with other government agencies. The exercise at the 2015 PDC involved most of the attendees, consisted of seven distinct steps (“injects”), and with all the presentations and discussions, took up nearly 10 hours of conference time. The trajectory for the PDC15 scenario was entirely realistic, and was posted ahead of the meeting. It was made available in the NEO Program’s Horizons ephemeris service so that users could , for example, design their own deflection missions. The simulated asteroid and trajectory had to meet numerous very exacting requirements: becoming observable on the very first day of the conference, yet remaining very difficult to observe for the following 7 years, and far enough away from Earth that it was out of reach of radar until just before impact. It had to be undetectable in the past, and yet provide multiple perihelion opportunities for deflection in the future. It had to impact in a very specific region of the Earth, a specific number of years after discovery. When observations of the asteroid are simulated to generate an uncertainty region, that entire region must impact the Earth along an axis that cuts across specific regions of the Earth, the “risk corridor”. This is important because asteroid deflections generally move an asteroid impact point along this corridor. One scenario had a requirement that the asteroid pass through a keyhole several years before impact. The PDC15 scenario had an additional constraint that multiple simulated kinetic impactor missions altered the trajectory at a deflection point midway between discovery and impact

  13. Ozone concentrations and damage for realistic future European climate and air quality scenarios

    NASA Astrophysics Data System (ADS)

    Hendriks, Carlijn; Forsell, Nicklas; Kiesewetter, Gregor; Schaap, Martijn; Schöpp, Wolfgang

    2016-11-01

    Ground level ozone poses a significant threat to human health from air pollution in the European Union. While anthropogenic emissions of precursor substances (NOx, NMVOC, CH4) are regulated by EU air quality legislation and will decrease further in the future, the emissions of biogenic NMVOC (mainly isoprene) may increase significantly in the coming decades if short-rotation coppice plantations are expanded strongly to meet the increased biofuel demand resulting from the EU decarbonisation targets. This study investigates the competing effects of anticipated trends in land use change, anthropogenic ozone precursor emissions and climate change on European ground level ozone concentrations and related health and environmental impacts until 2050. The work is based on a consistent set of energy consumption scenarios that underlie current EU climate and air quality policy proposals: a current legislation case, and an ambitious decarbonisation case. The Greenhouse Gas-Air Pollution Interactions and Synergies (GAINS) integrated assessment model was used to calculate air pollutant emissions for these scenarios, while land use change because of bioenergy demand was calculated by the Global Biosphere Model (GLOBIOM). These datasets were fed into the chemistry transport model LOTOS-EUROS to calculate the impact on ground level ozone concentrations. Health damage because of high ground level ozone concentrations is projected to decline significantly towards 2030 and 2050 under current climate conditions for both energy scenarios. Damage to plants is also expected to decrease but to a smaller extent. The projected change in anthropogenic ozone precursor emissions is found to have a larger impact on ozone damage than land use change. The increasing effect of a warming climate (+2-5 °C across Europe in summer) on ozone concentrations and associated health damage, however, might be higher than the reduction achieved by cutting back European ozone precursor emissions. Global

  14. Integrated Analysis of Market Transformation Scenarios with HyTrans

    SciTech Connect

    Greene, David L; Leiby, Paul Newsome; Bowman, David Charles

    2007-06-01

    This report presents alternative visions of the transition of light-duty vehicle transportation in the United States from petroleum to hydrogen power. It is a supporting document to the U.S. Department of Energy's Summary Report, "Analysis of the Transition to a Hydrogen Economy and the Potential Hydrogen Infrastructure Requirements" (U.S. DOE, 2007). Three alternative early transition scenarios were analyzed using a market simulation model called HyTrans. The HyTrans model simultaneously represents the behavior of fuel suppliers, vehicle manufacturers and consumers, explicitly recognizing the importance of fuel availability and the diversity of vehicle choices to consumers, and dependence of fuel supply on the existence of market demand. Competitive market outcomes are simulated by means of non-linear optimization of social surplus through the year 2050. The three scenarios specify different rates and geographical distributions of market penetration for hydrogen fuel cell vehicles from 2012 through 2025. Scenario 1 leads to 2 million vehicles on U.S. roads by 2025, while Scenarios 2 and 3 result in 5 million and 10 million FCVs in use by 2025, respectively. The HyTrans model "costs out" the transition scenarios and alternative policies for achieving them. It then tests whether the scenarios, together with the achievement of the DOE's technology goals for fuel cell vehicles and hydrogen infrastructure technologies could lead to a sustainable transition to hydrogen powered transportation. Given the achievement of DOE's ambitious technology goals, all three scenarios appear to lead to a sustainable transition to hydrogen. In the absence of early transition deployment effort, no transition is likely to begin before 2045. The cumulative costs of the transition scenarios to the government range from $8 billion to $45 billion, depending on the scenario, the policies adopted and the degree of cost-sharing with industry. In the absence of carbon constraining policies, the

  15. Impacts of potential CO2-reduction policies on air quality in the United States.

    PubMed

    Trail, Marcus A; Tsimpidi, Alexandra P; Liu, Peng; Tsigaridis, Kostas; Hu, Yongtao; Rudokas, Jason R; Miller, Paul J; Nenes, Athanasios; Russell, Armistead G

    2015-04-21

    Impacts of emissions changes from four potential U.S. CO2 emission reduction policies on 2050 air quality are analyzed using the community multiscale air quality model (CMAQ). Future meteorology was downscaled from the Goddard Institute for Space Studies (GISS) ModelE General Circulation Model (GCM) to the regional scale using the Weather Research Forecasting (WRF) model. We use emissions growth factors from the EPAUS9r MARKAL model to project emissions inventories for two climate tax scenarios, a combined transportation and energy scenario, a biomass energy scenario and a reference case. Implementation of a relatively aggressive carbon tax leads to improved PM2.5 air quality compared to the reference case as incentives increase for facilities to install flue-gas desulfurization (FGD) and carbon capture and sequestration (CCS) technologies. However, less capital is available to install NOX reduction technologies, resulting in an O3 increase. A policy aimed at reducing CO2 from the transportation sector and electricity production sectors leads to reduced emissions of mobile source NOX, thus reducing O3. Over most of the U.S., this scenario leads to reduced PM2.5 concentrations. However, increased primary PM2.5 emissions associated with fuel switching in the residential and industrial sectors leads to increased organic matter (OM) and PM2.5 in some cities.

  16. Landfill Gas Energy Benefits Calculator

    EPA Pesticide Factsheets

    This page contains the LFG Energy Benefits Calculator to estimate direct, avoided, and total greenhouse gas reductions, as well as environmental and energy benefits, for a landfill gas energy project.

  17. Safety evaluation of MHTGR licensing basis accident scenarios

    SciTech Connect

    Kroeger, P.G.

    1989-04-01

    The safety potential of the Modular High-Temperature Gas Reactor (MHTGR) was evaluated, based on the Preliminary Safety Information Document (PSID), as submitted by the US Department of Energy to the US Nuclear Regulatory Commission. The relevant reactor safety codes were extended for this purpose and applied to this new reactor concept, searching primarily for potential accident scenarios that might lead to fuel failures due to excessive core temperatures and/or to vessel damage, due to excessive vessel temperatures. The design basis accident scenario leading to the highest vessel temperatures is the depressurized core heatup scenario without any forced cooling and with decay heat rejection to the passive Reactor Cavity Cooling System (RCCS). This scenario was evaluated, including numerous parametric variations of input parameters, like material properties and decay heat. It was found that significant safety margins exist, but that high confidence levels in the core effective thermal conductivity, the reactor vessel and RCCS thermal emissivities and the decay heat function are required to maintain this safety margin. Severe accident extensions of this depressurized core heatup scenario included the cases of complete RCCS failure, cases of massive air ingress, core heatup without scram and cases of degraded RCCS performance due to absorbing gases in the reactor cavity. Except for no-scram scenarios extending beyond 100 hr, the fuel never reached the limiting temperature of 1600/degree/C, below which measurable fuel failures are not expected. In some of the scenarios, excessive vessel and concrete temperatures could lead to investment losses but are not expected to lead to any source term beyond that from the circulating inventory. 19 refs., 56 figs., 11 tabs.

  18. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Final report

    SciTech Connect

    Sublette, K.L.

    1994-03-01

    The main objective of this research was to investigate microorganisms capable of fossil fuel flue gas desulfurization and denitrification. The study used municipal sewage sludge as a carbon and energy source for SO{sub 2}-reducing cultures. The individual tasks developed a consortium of sulfate-reducing bacteria, investigated the design parameters for a continuous process, preformed a cost analysis, and screened sulfate-reducing bacteria. In the investigation of microbial reduction of NO{sub x} to nitrogen, tasks included screening denitrifying bacteria for NO and NO{sub 2} activity, developing optimum NO-reducing cultures, and investigating design parameters for a continuous system. This final report reviews the work previous to the current project, describes project objectives and the specific work plan, and reports results from the work completed during the previous reporting periods.

  19. The reduction of gas phase air toxics from combustion and incineration sources using the GE-MITSUI-BE activated coke process

    SciTech Connect

    Olson, D.G.

    1995-12-31

    The dry desulfurization, denitrification and air toxics removal process using activated coke (AC) was originally researched and developed during the 1960s by Bergbau Forschung (BF), now called Deutsche Montan Technologies. Mitsui Mining Company (MMC) signed a licensing agreement with BF in 1982 to investigate, test and adapt the system to the facilities in Japan. Japanese regulations are stricter than in the U.S. toward SO{sub x}/NO{sub x} pollutants, as well as flyash emissions from the utility industry, oil refineries and other industries. This process is installed on flour coal-fired boilers and Fluidized Catalytic Cracker (FCC) units. These plants were constructed by MCC in Japan and Uhde GmbH in Germany. General Electric Environmental Systems, Inc. (GEESI) signed a license agreement in 1992 with MMC and Mitsui and Company, Ltd. of Tokyo. Under this agreement, GEESI will market, design, fabricate and install the Mitsui-BF press for flue gas cleaning applications in North America. MMC also developed a technology to produce AC used in the dry DeSO{sub x}/DeNO{sub x}/Air Toxics removal process based on their own metallurgical coke manufacturing technology. This paper provides information on the details of MMC`s AC used in the dry DeSO{sub x}/DeNO{sub x}/Air Toxics removal process.

  20. Demonstration of natural gas reburn for NO{sub x} emissions reduction at Ohio Edison Company`s cyclone-fired Niles Plant Unit Number 1

    SciTech Connect

    Borio, R.W.; Lewis, R.D.; Koucky, R.W.; Lookman, A.A.; Manos, M.G.; Corfman, D.W.; Waddingham, A.L.; Johnson, S.A.

    1996-04-01

    Electric utility power plants account for about one-third of the NO{sub x} and two-thirds of the SO{sub 2} emissions in the US cyclone-fired boilers, while representing about 9% of the US coal-fired generating capacity, emit about 14% of the NO{sub x} produced by coal-fired utility boilers. Given this background, the Environmental Protection Agency, the Gas Research Institute, the Electric Power Research Institute, the Pittsburgh Energy Technology Center, and the Ohio Coal Development Office sponsored a program led by ABB Combustion Engineering, Inc. (ABB-CE) to demonstrate reburning on a cyclone-fired boiler. Ohio Edison provided Unit No. 1 at their Niles Station for the reburn demonstration along with financial assistance. The Niles Unit No. 1 reburn system was started up in September 1990. This reburn program was the first full-scale reburn system demonstration in the US. This report describes work performed during the program. The work included a review of reburn technology, aerodynamic flow model testing of reburn system design concepts, design and construction of the reburn system, parametric performance testing, long-term load dispatch testing, and boiler tube wall thickness monitoring. The report also contains a description of the Niles No. 1 host unit, a discussion of conclusions and recommendations derived from the program, tabulation of data from parametric and long-term tests, and appendices which contain additional tabulated test results.

  1. Spent fuel receipt scenarios study

    SciTech Connect

    Ballou, L.B.; Montan, D.N.; Revelli, M.A.

    1990-09-01

    This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs.

  2. Europa Explorer Operational Scenarios Development

    NASA Technical Reports Server (NTRS)

    Lock, Robert E.; Pappalardo, Robert T.; Clark, Karla B.

    2008-01-01

    In 2007, NASA conducted four advanced mission concept studies for outer planets targets: Europa, Ganymede, Titan and Enceladus. The studies were conducted in close cooperation with the planetary science community. Of the four, the Europa Explorer Concept Study focused on refining mission options, science trades and implementation details for a potential flagship mission to Europa in the 2015 timeframe. A science definition team (SDT) was appointed by NASA to guide the study. A JPL-led engineering team worked closely with the science team to address 3 major focus areas: 1) credible cost estimates, 2) rationale and logical discussion of radiation risk and mitigation approaches, and 3) better definition and exploration of science operational scenario trade space. This paper will address the methods and results of the collaborative process used to develop Europa Explorer operations scenarios. Working in concert with the SDT, and in parallel with the SDT's development of a science value matrix, key mission capabilities and constraints were challenged by the science and engineering members of the team. Science goals were advanced and options were considered for observation scenarios. Data collection and return strategies were tested via simulation, and mission performance was estimated and balanced with flight and ground system resources and science priorities. The key to this successful collaboration was a concurrent development environment in which all stakeholders could rapidly assess the feasibility of strategies for their success in the full system context. Issues of science and instrument compatibility, system constraints, and mission opportunities were treated analytically and objectively leading to complementary strategies for observation and data return. Current plans are that this approach, as part of the system engineering process, will continue as the Europa Explorer Concept Study moves toward becoming a development project.

  3. Estimating the health benefits from natural gas use in transport and heating in Santiago, Chile.

    PubMed

    Mena-Carrasco, Marcelo; Oliva, Estefania; Saide, Pablo; Spak, Scott N; de la Maza, Cristóbal; Osses, Mauricio; Tolvett, Sebastián; Campbell, J Elliott; Tsao, Tsao Es Chi-Chung; Molina, Luisa T

    2012-07-01

    Chilean law requires the assessment of air pollution control strategies for their costs and benefits. Here we employ an online weather and chemical transport model, WRF-Chem, and a gridded population density map, LANDSCAN, to estimate changes in fine particle pollution exposure, health benefits, and economic valuation for two emission reduction strategies based on increasing the use of compressed natural gas (CNG) in Santiago, Chile. The first scenario, switching to a CNG public transportation system, would reduce urban PM2.5 emissions by 229 t/year. The second scenario would reduce wood burning emissions by 671 t/year, with unique hourly emission reductions distributed from daily heating demand. The CNG bus scenario reduces annual PM2.5 by 0.33 μg/m³ and up to 2 μg/m³ during winter months, while the residential heating scenario reduces annual PM2.5 by 2.07 μg/m³, with peaks exceeding 8 μg/m³ during strong air pollution episodes in winter months. These ambient pollution reductions lead to 36 avoided premature mortalities for the CNG bus scenario, and 229 for the CNG heating scenario. Both policies are shown to be cost-effective ways of reducing air pollution, as they target high-emitting area pollution sources and reduce concentrations over densely populated urban areas as well as less dense areas outside the city limits. Unlike the concentration rollback methods commonly used in public policy analyses, which assume homogeneous reductions across a whole city (including homogeneous population densities), and without accounting for the seasonality of certain emissions, this approach accounts for both seasonality and diurnal emission profiles for both the transportation and residential heating sectors.

  4. Determining air quality and greenhouse gas impacts of hydrogen infrastructure and fuel cell vehicles.

    PubMed

    Stephens-Romero, Shane; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald; Samuelsen, Scott

    2009-12-01

    Adoption of hydrogen infrastructure and hydrogen fuel cell vehicles (HFCVs) to replace gasoline internal combustion engine (ICE) vehicles has been proposed as a strategy to reduce criteria pollutant and greenhouse gas (GHG) emissions from the transportation sector and transition to fuel independence. However, it is uncertain (1) to what degree the reduction in criteria pollutants will impact urban air quality, and (2) how the reductions in pollutant emissions and concomitant urban air quality impacts compare to ultralow emission gasoline-powered vehicles projected for a future year (e.g., 2060). To address these questions, the present study introduces a "spatially and temporally resolved energy and environment tool" (STREET) to characterize the pollutant and GHG emissions associated with a comprehensive hydrogen supply infrastructure and HFCVs at a high level of geographic and temporal resolution. To demonstrate the utility of STREET, two spatially and temporally resolved scenarios for hydrogen infrastructure are evaluated in a prototypical urban airshed (the South Coast Air Basin of California) using geographic information systems (GIS) data. The well-to-wheels (WTW) GHG emissions are quantified and the air quality is established using a detailed atmospheric chemistry and transport model followed by a comparison to a future gasoline scenario comprised of advanced ICE vehicles. One hydrogen scenario includes more renewable primary energy sources for hydrogen generation and the other includes more fossil fuel sources. The two scenarios encompass a variety of hydrogen generation, distribution, and fueling strategies. GHG emissions reductions range from 61 to 68% for both hydrogen scenarios in parallel with substantial improvements in urban air quality (e.g., reductions of 10 ppb in peak 8-h-averaged ozone and 6 mug/m(3) in 24-h-averaged particulate matter concentrations, particularly in regions of the airshed where concentrations are highest for the gasoline scenario).

  5. Green analyzer for the measurement of total arsenic in drinking water: electrochemical reduction of arsenate to arsine and gas phase chemiluminescence with ozone.

    PubMed

    Sengupta, Mrinal K; Sawalha, Maather F; Ohira, Shin-Ichi; Idowu, Ademola D; Dasgupta, Purnendu K

    2010-05-01

    We describe matrix-isolated, reaction chemistry based measurement of arsenic in water down to submicrograms per liter levels in a system that requires only air, water, electricity, and dilute sulfuric acid, the bulk of the latter being recycled. Gas phase chemiluminescence (GPCL) measurement of arsenic is made in an automated batch system with arsenic in situ electroreduced to arsine that is reacted with ozone to emit light. The ozone is generated from oxygen that is simultaneously anodically produced. Of 22 different electrode materials studied, graphite was chosen as the cathode. As(V) is reduced much less efficiently to AsH(3) than As(III). Prereducing all As to As(III) is difficult in the field and tedious. Oxidizing all As to As(V) is simple (e.g., with NaOCl) but greatly reduces subsequent conversion to AsH(3) and hence sensitivity. The rate of the AsH(3)-O(3) GPCL reaction and hence signal intensity increases with [O(3)]. Using oxygen to feed the ozonizer produces higher [O(3)] and substantial signal enhancement. This makes it practical to measure all arsenic as As(V). The system exhibits an LOD (S/N = 3) for total arsenic as As(V) of 0.36 microg/L (5 mL sample). Comparison of total As results in native and spiked water samples with those from inductively coupled plasma mass spectrometry (ICPMS) and other techniques show high correlation (r(2) = 0.9999) and near unity slopes.

  6. Impacts of reductions in emissions of multipollutants over 2005-2030 on regional air quality and climate

    NASA Astrophysics Data System (ADS)

    Liao, H.; Yang, Y.; Chang, W.; Shindell, D. T.; Faluvegi, G.

    2011-12-01

    Many societal activities lead to emissions to the atmosphere that affect both air quality and climate. We examine how particular policies may be able to provide benefits in both these areas using three coupled global chemistry-climate models (CACTUS, GISS-PUCCINI, and NCAR-CESM). The anthropogenic emissions for years 2005 and 2030 are taken from the datasets generated by the International Institute for Applied Systems Analysis (IIASA) GAINS (Greenhouse gas-Air pollution Interactions and Synergies) model. The 2030 emissions scenarios include (1) a reference scenario, (2) a low GWP scenario, and (3) the lowest emissions scenario. The reference scenario assumes that all agreed air pollution policies are being implemented, and the other two scenarios have additional reductions in emissions based on a selected set of measures. We firstly evaluate the model predictions for 2005, and then investigate the simulated year 2030 concentrations of ozone, sulfate, black carbon, and organic carbon, aerosol optical depth, as well as year 2030 radiative forcing relative to 2005. Both direct and indirect radiative forcings of aerosols are considered. Our model results suggest that taking measures to reduce emissions in China can reduce year 2030 PM2.5 concentrations in China by 20-60% and help to mitigate near-term regional climate change.

  7. Regional allocation of biomass to U.S. energy demands under a portfolio of policy scenarios.

    PubMed

    Mullins, Kimberley A; Venkatesh, Aranya; Nagengast, Amy L; Kocoloski, Matt

    2014-01-01

    The potential for widespread use of domestically available energy resources, in conjunction with climate change concerns, suggest that biomass may be an essential component of U.S. energy systems in the near future. Cellulosic biomass in particular is anticipated to be used in increasing quantities because of policy efforts, such as federal renewable fuel standards and state renewable portfolio standards. Unfortunately, these independently designed biomass policies do not account for the fact that cellulosic biomass can equally be used for different, competing energy demands. An integrated assessment of multiple feedstocks, energy demands, and system costs is critical for making optimal decisions about a unified biomass energy strategy. This study develops a spatially explicit, best-use framework to optimally allocate cellulosic biomass feedstocks to energy demands in transportation, electricity, and residential heating sectors, while minimizing total system costs and tracking greenhouse gas emissions. Comparing biomass usage across three climate policy scenarios suggests that biomass used for space heating is a low cost emissions reduction option, while biomass for liquid fuel or for electricity becomes attractive only as emissions reduction targets or carbon prices increase. Regardless of the policy approach, study results make a strong case for national and regional coordination in policy design and compliance pathways.

  8. Scenarios for coastal vulnerability assessment

    USGS Publications Warehouse

    Nicholls, Robert J.; Woodroffe, Colin D.; Burkett, Virginia; Hay, John; Wong, Poh Poh; Nurse, Leonard; Wolanski, Eric; McLusky, Donald S.

    2011-01-01

    Coastal vulnerability assessments tend to focus mainly on climate change and especially on sea-level rise. Assessment of the influence of nonclimatic environmental change or socioeconomic change is less well developed and these drivers are often completely ignored. Given that the most profound coastal changes of the twentieth century due to nonclimate drivers are likely to continue through the twenty-first century, this is a major omission. It may result in not only overstating the importance of climate change but also overlooking significant interactions of climate change and other drivers. To support the development of policies relating to climate change and coastal management, integrated assessments of climatic change in coastal areas are required, including the effects of all the relevant drivers. This chapter explores the development of scenarios (or "plausible futures") of relevant climate and nonclimate drivers that can be used for coastal analysis, with an emphasis on the nonclimate drivers. It shows the importance of analyzing the impacts of climate change and sea-level rise in a broader context of coastal change and all its drivers. This will improve the analysis of impacts, key vulnerabilities, and adaptation needs and, hence, inform climate and coastal policy. Stakeholder engagement is important in the development of scenarios, and the underlying assumptions need to be explicit, transparent, and open to scientific debate concerning their uncertainties/realism and likelihood.

  9. Comparing the greenhouse gas emissions from three alternative waste combustion concepts

    SciTech Connect

    Vainikka, Pasi; Tsupari, Eemeli; Sipilae, Kai; Hupa, Mikko

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Significant GHG reductions are possible by efficient WtE technologies. Black-Right-Pointing-Pointer CHP and high power-to-heat ratio provide significant GHG savings. Black-Right-Pointing-Pointer N{sub 2}O and coal mine type are important in LCA GHG emissions of FBC co-combustion. Black-Right-Pointing-Pointer Substituting coal and fuel oil by waste is beneficial in electricity and heat production. Black-Right-Pointing-Pointer Substituting natural gas by waste may not be reasonable in CHP generation. - Abstract: Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO{sub 2}-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

  10. Scenario Development for the Southwestern United States

    NASA Astrophysics Data System (ADS)

    Mahmoud, M.; Gupta, H.; Stewart, S.; Liu, Y.; Hartmann, H.; Wagener, T.

    2006-12-01

    The primary goal of employing a scenario development approach for the U.S. southwest is to inform regional policy by examining future possibilities related to regional vegetation change, water-leasing, and riparian restoration. This approach is necessary due to a lack of existing explicit water resources application of scenarios to the entire southwest region. A formal approach for scenario development is adopted and applied towards water resources issues within the arid and semi-arid regions of the U.S. southwest following five progressive and reiterative phases: scenario definition, scenario construction, scenario analysis, scenario assessment, and risk management. In the scenario definition phase, the inputs of scientists, modelers, and stakeholders were collected in order to define and construct relevant scenarios to the southwest and its water sustainability needs. From stakeholder-driven scenario workshops and breakout sessions, the three main axes of principal change were identified to be climate change, population development patterns, and quality of information monitoring technology. Based on the extreme and varying conditions of these three main axes, eight scenario narratives were drafted to describe the state of each scenario's respective future and the events which led to it. Events and situations are described within each scenario narrative with respect to key variables; variables that are both important to regional water resources (as distinguished by scientists and modelers), and are good tracking and monitoring indicators of change. The current phase consists of scenario construction, where the drafted scenarios are re-presented to regional scientists and modelers to verify that proper key variables are included (or excluded) from the eight narratives. The next step is to construct the data sets necessary to implement the eight scenarios on the respective computational models of modelers investigating vegetation change, water-leasing, and riparian

  11. Computational Study of Scenarios Regarding Explosion Risk Mitigation

    NASA Astrophysics Data System (ADS)

    Vlasin, Nicolae-Ioan; Mihai Pasculescu, Vlad; Florea, Gheorghe-Daniel; Cornel Suvar, Marius

    2016-10-01

    Exploration in order to discover new deposits of natural gas, upgrading techniques to exploit these resources and new ways to convert the heat capacity of these gases into industrial usable energy is the research areas of great interest around the globe. But all activities involving the handling of natural gas (exploitation, transport, combustion) are subjected to the same type of risk: the risk to explosion. Experiments carried out physical scenarios to determine ways to reduce this risk can be extremely costly, requiring suitable premises, equipment and apparatus, manpower, time and, not least, presenting the risk of personnel injury. Taking in account the above mentioned, the present paper deals with the possibility of studying the scenarios of gas explosion type events in virtual domain, exemplifying by performing a computer simulation of a stoichiometric air - methane explosion (methane is the main component of natural gas). The advantages of computer-assisted imply are the possibility of using complex virtual geometries of any form as the area of deployment phenomenon, the use of the same geometry for an infinite number of settings of initial parameters as input, total elimination the risk of personnel injury, decrease the execution time etc. Although computer simulations are hardware resources consuming and require specialized personnel to use the CFD (Computational Fluid Dynamics) techniques, the costs and risks associated with these methods are greatly diminished, presenting, in the same time, a major benefit in terms of execution time.

  12. The ShakeOut Scenario

    USGS Publications Warehouse

    Jones, Lucile M.; Bernknopf, Richard; Cox, Dale; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Perry, Suzanne; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne

    2008-01-01

    This is the initial publication of the results of a cooperative project to examine the implications of a major earthquake in southern California. The study comprised eight counties: Imperial, Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura. Its results will be used as the basis of an emergency response and preparedness exercise, the Great Southern California ShakeOut, and for this purpose we defined our earthquake as occurring at 10:00 a.m. on November 13, 2008. As members of the southern California community use the ShakeOut Scenario to plan and execute the exercise, we anticipate discussion and feedback. This community input will be used to refine our assessment and will lead to a formal publication in early 2009. Our goal in the ShakeOut Scenario is to identify the physical, social and economic consequences of a major earthquake in southern California and in so doing, enable the users of our results to identify what they can change now?before the earthquake?to avoid catastrophic impact after the inevitable earthquake occurs. To do so, we had to determine the physical damages (casualties and losses) caused by the earthquake and the impact of those damages on the region?s social and economic systems. To do this, we needed to know about the earthquake ground shaking and fault rupture. So we first constructed an earthquake, taking all available earthquake research information, from trenching and exposed evidence of prehistoric earthquakes, to analysis of instrumental recordings of large earthquakes and the latest theory in earthquake source physics. We modeled a magnitude (M) 7.8 earthquake on the southern San Andreas Fault, a plausible event on the fault most likely to produce a major earthquake. This information was then fed forward into the rest of the ShakeOut Scenario. The damage impacts of the scenario earthquake were estimated using both HAZUS-MH and expert opinion through 13 special studies and 6 expert panels, and fall into four

  13. Superclustering in the explosion scenario

    NASA Technical Reports Server (NTRS)

    Weinberg, David H.; Ostriker, Jeremiah P.; Dekel, Avishai

    1989-01-01

    A simple toy model is used to study the spatial distribution of rich clusters in a generic type of explosion scenario. The model, parameterized by the distribution of shell radii and the filling factor, places spherical shells at random and identifies each 'knot' as a cluster. The resulting cluster correlation function is close to a power law extending to the diameter of the largest spheres. Richer clusters form at the intersections of bigger shells and so have stronger correlations. Typical shell radii and filling factors are required to produce the observed number density of clusters. Models with a power-law radius distribution also reproduce the richness distribution of clusters in the Abell catalog. Supercluster multiplicity functions, void probabilities, number counts, topology statistics, and velocity correlations confirm the presence of strong superclustering and quantify the non-Gaussian nature of the model.

  14. Radiation Detection Computational Benchmark Scenarios

    SciTech Connect

    Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

    2013-09-24

    Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for

  15. Low-Carbon Natural Gas for Transportation: Well-to-Wheels Emissions and Potential Market Assessment in California

    SciTech Connect

    Penev, Michael; Melaina, Marc; Bush, Brian; Muratori, Matteo; Warner, Ethan; Chen, Yuche

    2016-12-01

    This report improves on the understanding of the long-term technology potential of low-carbon natural gas (LCNG) supply pathways by exploring transportation market adoption potential through 2035 in California. Techno-economic assessments of each pathway are developed to compare the capacity, cost, and greenhouse gas (GHG) emissions of select LCNG production pathways. The study analyzes the use of fuel from these pathways in light-, medium-, and heavy-duty vehicle applications. Economic and life-cycle GHG emissions analysis suggest that landfill gas resources are an attractive and relatively abundant resource in terms of cost and GHG reduction potential, followed by waste water treatment plants and biomass with gasification and methanation. Total LCNG production potential is on the order of total natural gas demand anticipated in a success scenario for future natural gas vehicle adoption by 2035 across light-, medium-, and heavy-duty vehicle markets (110 trillion Btu/year).

  16. Decadal application of WRF/chem for regional air quality and climate modeling over the U.S. under the representative concentration pathways scenarios. Part 2: Current vs. future simulations

    NASA Astrophysics Data System (ADS)

    Yahya, Khairunnisa; Campbell, Patrick; Zhang, Yang

    2017-03-01

    Following a comprehensive model evaluation, this Part II paper presents projected changes in future (2046-2055) climate, air quality, and their interactions under the RCP4.5 and RCP8.5 scenarios using the Weather, Research and Forecasting model with Chemistry (WRF/Chem). In general, both WRF/Chem RCP4.5 and RCP8.5 simulations predict similar increases on average (∼2 °C) for 2-m temperature (T2) but different spatial distributions of the projected changes in T2, 2-m relative humidity, 10-m wind speed, precipitation, and planetary boundary layer height, due to differences in the spatial distributions of projected emissions, and their feedbacks into climate. Future O3 mixing ratios will decrease for most parts of the U.S. under the RCP4.5 scenario but increase for all areas under the RCP8.5 scenario due to higher projected temperature, greenhouse gas concentrations and biogenic volatile organic compounds (VOC) emissions, higher O3 values for boundary conditions, and disbenefit of NOx reduction and decreased NO titration over VOC-limited O3 chemistry regions. Future PM2.5 concentrations will decrease for both RCP4.5 and RCP8.5 scenarios with different trends in projected concentrations of individual PM species. Total cloud amounts decrease under both scenarios in the future due to decreases in PM and cloud droplet number concentration thus increased radiation. Those results illustrate the impacts of carbon policies with different degrees of emission reductions on future climate and air quality. The WRF/Chem and WRF simulations show different spatial patterns for projected changes in T2 for future decade, indicating different impacts of prognostic and prescribed gas/aerosol concentrations, respectively, on climate change.

  17. SELECTIVE CATALYTIC REDUCTION MERCURY FIELD SAMPLING PROJECT

    EPA Science Inventory

    A lack of data still exists as to the effect of selective catalytic reduction (SCR), selective noncatalytic reduction (SNCR), and flue gas conditioning on the speciation and removal of mercury (Hg) at power plants. This project investigates the impact that SCR, SNCR, and flue gas...

  18. Environmental assessment of low-organic waste landfill scenarios by means of life-cycle assessment modelling (EASEWASTE).

    PubMed

    Manfredi, Simone; Christensen, Thomas H; Scharff, Heijo; Jacobs, Joeri

    2010-02-01

    The environmental performance of two low-organic waste landfill scenarios ('low-organic-energy' and 'low-organic-flare') was developed and compared with two household waste landfill scenarios ('household-energy' and 'household-flare') by means of LCA-modelling. The LCA-modelling was made for 1 tonne of wet waste landfilled and the environmental aspects were evaluated for a 100-year period after disposal. The data utilized in the LCA-calculations to model the first 10-20 years of landfilling of the two low-organic waste scenarios make extensive use of site-specific data from the Nauerna Landfill (The Netherlands), but average data from other comparable, existing landfills were used too. As data from full-scale landfills do not cover more than 30-40 years of landfilling, data from laboratory simulations and accelerated tests of limited scale were also utilized. The life-cycle impact assessments show that the low-organic waste scenarios achieved better environmental performance than the household waste scenarios with regard to both ordinary and toxicity-related environmental impact categories. This indicates that the reduction of organic matter accepted at landfills (as prescribed by the European Union Landfill Directive: Council Directive 1999/31/EC, EU, Brussels, 1999) can be a successful approach to decrease the environmental loads in several impact categories in comparison with landfilling of waste with significant organic content. However, when utilization of landfill gas is accounted for in the life-cycle impact assessment calculation, the small gas generation in low-organic waste landfills reduced the actual potential for energy generation and therefore the environmental savings obtained were reduced proportionally. Groundwater pollution from input of leachate was also evaluated and the WHO (Guidelines for Drinking-water Quality; WHO, Geneva, 2006) guideline for drinking water quality was assumed as reference. The results show that low-organic waste landfills

  19. Assessment of Co-benefits of vehicle emission reduction measures for 2015-2020 in the Pearl River Delta region, China.

    PubMed

    Liu, Yong-Hong; Liao, Wen-Yuan; Lin, Xiao-Fang; Li, Li; Zeng, Xue-Lan

    2017-04-01

    Vehicle emissions have become one of the key factors affecting the urban air quality and climate change in the Pearl River Delta (PRD) region, so it is important to design policies of emission reduction based on quantitative Co-benefits for air pollutants and greenhouse gas (GHG). Emissions of air pollutants and GHG by 2020 was predicted firstly based on the no-control scenario, and five vehicle emissions reduction scenarios were designed in view of the economy, technology and policy, whose emissions reduction were calculated. Then Co-benefits between air pollutants and GHG were quantitatively analyzed by the methods of coordinate system and cross-elasticity. Results show that the emissions reduction effects and the Co-benefits of different measures vary greatly in 2015-2020. If no control scheme was applied, most air pollutants and GHG would increase substantially by 20-64% by 2020, with the exception of CO, VOC and PM2.5. Different control measures had different reduction effects for single air pollutant and GHG. The worst reduction measure was Eliminating Motorcycles with average reducing rate 0.09% for air pollutants and GHG, while the rate from Updated Emission Standard was 41.74%. Eliminating Yellow-label Vehicle scenario had an obvious reduction effect for every single pollutant in the earlier years, but Co-benefits would descent to zero in later by 2020. From the perspective of emission reductions and co-control effect, Updated Emission Standard scenario was best for reducing air pollutants and GHG substantially (tanα=1.43 and Els=1.77).

  20. Transportation Energy Futures Series: Alternative Fuel Infrastructure Expansion: Costs, Resources, Production Capacity, and Retail Availability for Low-Carbon Scenarios

    SciTech Connect

    Melaina, M. W.; Heath, G.; Sandor, D.; Steward, D.; Vimmerstedt, L.; Warner, E.; Webster, K. W.

    2013-04-01

    Achieving the Department of Energy target of an 80% reduction in greenhouse gas emissions by 2050 depends on transportation-related strategies combining technology innovation, market adoption, and changes in consumer behavior. This study examines expanding low-carbon transportation fuel infrastructure to achieve deep GHG emissions reductions, with an emphasis on fuel production facilities and retail components serving light-duty vehicles. Three distinct low-carbon fuel supply scenarios are examined: Portfolio: Successful deployment of a range of advanced vehicle and fuel technologies; Combustion: Market dominance by hybridized internal combustion engine vehicles fueled by advanced biofuels and natural gas; Electrification: Market dominance by electric drive vehicles in the LDV sector, including battery electric, plug-in hybrid, and fuel cell vehicles, that are fueled by low-carbon electricity and hydrogen. A range of possible low-carbon fuel demand outcomes are explored in terms of the scale and scope of infrastructure expansion requirements and evaluated based on fuel costs, energy resource utilization, fuel production infrastructure expansion, and retail infrastructure expansion for LDVs. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored transportation-related strategies for abating GHGs and reducing petroleum dependence.

  1. Environmental impacts of high penetration renewable energy scenarios for Europe

    NASA Astrophysics Data System (ADS)

    Berrill, Peter; Arvesen, Anders; Scholz, Yvonne; Gils, Hans Christian; Hertwich, Edgar G.

    2016-01-01

    The prospect of irreversible environmental alterations and an increasingly volatile climate pressurises societies to reduce greenhouse gas emissions, thereby mitigating climate change impacts. As global electricity demand continues to grow, particularly if considering a future with increased electrification of heat and transport sectors, the imperative to decarbonise our electricity supply becomes more urgent. This letter implements outputs of a detailed power system optimisation model into a prospective life cycle analysis framework in order to present a life cycle analysis of 44 electricity scenarios for Europe in 2050, including analyses of systems based largely on low-carbon fossil energy options (natural gas, and coal with carbon capture and storage (CCS)) as well as systems with high shares of variable renewable energy (VRE) (wind and solar). VRE curtailments and impacts caused by extra energy storage and transmission capabilities necessary in systems based on VRE are taken into account. The results show that systems based largely on VRE perform much better regarding climate change and other impact categories than the investigated systems based on fossil fuels. The climate change impacts from Europe for the year 2050 in a scenario using primarily natural gas are 1400 Tg CO2-eq while in a scenario using mostly coal with CCS the impacts are 480 Tg CO2-eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120-140 Tg CO2-eq. Impacts arising as a result of wind and solar variability do not significantly compromise the climate benefits of utilising these energy resources. VRE systems require more infrastructure leading to much larger mineral resource depletion impacts than fossil fuel systems, and greater land occupation impacts than systems based on natural gas. Emissions and resource requirements from wind power are smaller than from solar power.

  2. Overview of a new scenario framework for climate change research

    NASA Astrophysics Data System (ADS)

    Ebi, K. L.

    2013-12-01

    The scientific community is developing new integrated global, regional, and sectoral scenarios to facilitate interdisciplinary research and assessment to explore the range of possible future climates and related physical changes; the risks these could pose to human and natural systems, particularly how these changes could interact with social, economic, and environmental development pathways; the degree to which mitigation and adaptation policies can avoid and reduce the risks; the costs and benefits of various policy mixes; residual impacts under alternative pathways; and the relationship with sustainable development. Developing new scenarios for use in impacts, adaptation, and mitigation research requires more than emissions of greenhouse gases and resulting climate change. Scenarios also require assumptions about socioeconomic development, including a narrative, and qualitative and quantitative assumptions about development patterns. An insight recently gained is that the magnitude and extent of greenhouse gas emissions is relatively independent of demographic and socioeconomic development; that is, multiple demographic and socioeconomic development pathways can lead to any particular emission scenario. A relatively wealthy world with high population density could have low greenhouse gas emissions because of policies that encourage energy efficiency and sufficient low emission technology. The opposite also is plausible. Therefore, demographic and socioeconomic development pathways can be described separately from the Representative Concentration Pathways and then combined using a matrix architecture into a broader range of scenarios than was possible with the SRES. Shared Socioeconomic Pathways (SSPs) define the state of human and natural societies at a macro scale. To encompass a wide range of possible development pathways, five SSPs are defined along two axes describing worlds with increasing socioeconomic challenges to mitigation (y-axis) and adaptation (x

  3. Hyperspectral Anomaly Detection in Urban Scenarios

    NASA Astrophysics Data System (ADS)

    Rejas Ayuga, J. G.; Martínez Marín, R.; Marchamalo Sacristán, M.; Bonatti, J.; Ojeda, J. C.

    2016-06-01

    We have studied the spectral features of reflectance and emissivity in the pattern recognition of urban materials in several single hyperspectral scenes through a comparative analysis of anomaly detection methods and their relationship with city surfaces with the aim to improve information extraction processes. Spectral ranges of the visible-near infrared (VNIR), shortwave infrared (SWIR) and thermal infrared (TIR) from hyperspectral data cubes of AHS sensor and HyMAP and MASTER of two cities, Alcalá de Henares (Spain) and San José (Costa Rica) respectively, have been used. In this research it is assumed no prior knowledge of the targets, thus, the pixels are automatically separated according to their spectral information, significantly differentiated with respect to a background, either globally for the full scene, or locally by image segmentation. Several experiments on urban scenarios and semi-urban have been designed, analyzing the behaviour of the standard RX anomaly detector and different methods based on subspace, image projection and segmentation-based anomaly detection methods. A new technique for anomaly detection in hyperspectral data called DATB (Detector of Anomalies from Thermal Background) based on dimensionality reduction by projecting targets with unknown spectral signatures to a background calculated from thermal spectrum wavelengths is presented. First results and their consequences in non-supervised classification and extraction information processes are discussed.

  4. Realities of leprosy control: updating scenarios.

    PubMed

    Gonçalves, Aguinaldo

    2013-09-01

    In the light of successive therapeutical difficulties for leprosy control, the application of drug therapy combination over the last decades has brought about an expectation of cure for leprosy patients and also for the elimination of this illness as a Public Health problem. However, there has been a progressive reduction in the prevalence of leprosy, but without any apparent impact on transmission, which has led to recognized need for solid assessment of respective epidemiological evidence as grounds for interventions to solve the problem. In this regard, here we present a retroanalytical qualitative and quantitative study, combined with a prospective diachronic approach, based on the association of documental review techniques and analysis of content, involving the following phases in succession: assembly of an operational scheme, execution of search strategy, application of criteria, selection of studies, data extraction and processing, implementation of analysis plan and preparation of final text. The appropriate execution of the procedures, as applied, allows us to obtain and discuss the identification of three main scenarios: the elimination of the illness as a public health problem (Neglected Illness); therapeutic aspects (Resistance; Relapse; Non-Adherence; Persistence) and complexity (complications and physical incapacities). The conclusions that have been reached indicate,mainly, that the reality of leprosy control with the use of combination drug therapy, still needs to be handled with care, even more so as this is just a fragment of the set of people once under medical attention, which also correspond to a parcel of the set of people affected by the ailment.

  5. Realistic Ground Motion Scenarios: Methodological Approach

    SciTech Connect

    Nunziata, C.; Peresan, A.; Romanelli, F.; Vaccari, F.; Zuccolo, E.; Panza, G. F.

    2008-07-08

    The definition of realistic seismic input can be obtained from the computation of a wide set of time histories, corresponding to possible seismotectonic scenarios. The propagation of the waves in the bedrock from the source to the local laterally varying structure is computed with the modal summation technique, while in the laterally heterogeneous structure the finite difference method is used. The definition of shear wave velocities within the soil cover is obtained from the non-linear inversion of the dispersion curve of group velocities of Rayleigh waves, artificially or naturally generated. Information about the possible focal mechanisms of the sources can be obtained from historical seismicity, based on earthquake catalogues and inversion of isoseismal maps. In addition, morphostructural zonation and pattern recognition of seismogenic nodes is useful to identify areas prone to strong earthquakes, based on the combined analysis of topographic, tectonic, geological maps and satellite photos. We show that the quantitative knowledge of regional geological structures and the computation of realistic ground motion can be a powerful tool for a preventive definition of the seismic hazard in Italy. Then, the formulation of reliable building codes, based on the evaluation of the main potential earthquakes, will have a great impact on the effective reduction of the seismic vulnerability of Italian urban areas, validating or improving the national building code.

  6. Valve for gas centrifuges

    DOEpatents

    Hahs, Charles A.; Burbage, Charles H.

    1984-01-01

    The invention is a pneumatically operated valve assembly for simultaneously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two of the lines so closed. The valve assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  7. Energy conservation and CO2 emission reductions due to recycling in Brazil.

    PubMed

    Pimenteira, C A P; Pereira, A S; Oliveira, L B; Rosa, L P; Reis, M M; Henriques, R M

    2004-01-01

    The present paper aims to make the energy saving potential provided by waste recycling in Brazil evident by pointing out more specifically the benefits regarding climate change mitigation. In this case, based on the energy saved due to the recycling process of an exogenous amount of waste, we have built two scenarios in order to show the potential for indirectly avoiding CO2 emissions in the country as a result of the recycling process. According to the scenario, 1 Mt and 3.5 Mt of CO2, respectively, would be avoided per year due to solid waste recycling. The international context for greenhouse gas emissions reduction, such as the United Nations Framework Convention on Climate Change and its Kyoto Protocol has been taken into account.

  8. Web Based Tool for Mission Operations Scenarios

    NASA Technical Reports Server (NTRS)

    Boyles, Carole A.; Bindschadler, Duane L.

    2008-01-01

    A conventional practice for spaceflight projects is to document scenarios in a monolithic Operations Concept document. Such documents can be hundreds of pages long and may require laborious updates. Software development practice utilizes scenarios in the form of smaller, individual use cases, which are often structured and managed using UML. We have developed a process and a web-based scenario tool that utilizes a similar philosophy of smaller, more compact scenarios (but avoids the formality of UML). The need for a scenario process and tool became apparent during the authors' work on a large astrophysics mission. It was noted that every phase of the Mission (e.g., formulation, design, verification and validation, and operations) looked back to scenarios to assess completeness of requirements and design. It was also noted that terminology needed to be clarified and structured to assure communication across all levels of the project. Attempts to manage, communicate, and evolve scenarios at all levels of a project using conventional tools (e.g., Excel) and methods (Scenario Working Group meetings) were not effective given limitations on budget and staffing. The objective of this paper is to document the scenario process and tool created to offer projects a low-cost capability to create, communicate, manage, and evolve scenarios throughout project development. The process and tool have the further benefit of allowing the association of requirements with particular scenarios, establishing and viewing relationships between higher- and lower-level scenarios, and the ability to place all scenarios in a shared context. The resulting structured set of scenarios is widely visible (using a web browser), easily updated, and can be searched according to various criteria including the level (e.g., Project, System, and Team) and Mission Phase. Scenarios are maintained in a web-accessible environment that provides a structured set of scenario fields and allows for maximum

  9. Calculation of greenhouse gas emissions of jatropha oil and jatropha biodiesel as alternative fuels for electricity production in Côte d'Ivoire

    NASA Astrophysics Data System (ADS)

    Atta, Pascal Atta; N'guessan, Yao; Morin, Celine; Voirol, Anne Jaecker; Descombes, Georges

    2017-02-01

    The electricity in Côte d'Ivoire is mainly produced from fossil energy sources. This causes damages on environment due to greenhouse gas emissions (GHG). The aim of this paper is to calculate the greenhouse gas (GHG) emissions of jatropha oil and jatropha biodiesel as alternative fuels for electricity production in Côte d'Ivoire by using Life Cycle Assessment (LCA) methodology. The functional unit in this LCA is defined as 1 kWh of electricity produced by the combustion of jatropha oil or jatropha biodiesel in the engine of a generator. Two scenarios, called short chain and long chain, were examined in this LCA. The results show that 0.132 kg CO2 equivalent is emitted for the scenario 1 with jatropha oil as an alternative fuel against 0.6376 kg CO2 equivalent for the scenario 2 with jatropha biodiesel as an alternative fuel. An 87 % reduction of kg CO2 equivalent is observed in scenario 1 and a 37 % reduction of kg CO2 equivalent is observed in the scenario 2, when compared with a Diesel fuel.

  10. Innovations in science and scenarios for assessment.

    PubMed

    Kunkel, Kenneth E; Moss, Richard; Parris, Adam

    Scenarios for the Third National Climate Assessment (NCA3) were produced for physical climate and sea level rise with substantial input from disciplinary and regional experts. These scenarios underwent extensive review and were published as NOAA Technical Reports. For land use/cover and socioeconomic conditions, scenarios already developed by other agencies were specified for use in the NCA3. Efforts to enhance participatory scenario planning as an assessment activity were pursued, but with limited success. Issues and challenges included the timing of availability of scenarios, the need for guidance in use of scenarios, the need for approaches to nest information within multiple scales and sectors, engagement and collaboration of end users in scenario development, and development of integrated scenarios. Future assessments would benefit from an earlier start to scenarios development, the provision of training in addition to guidance documents, new and flexible approaches for nesting information, ongoing engagement and advice from both scientific and end user communities, and the development of consistent and integrated scenarios.

  11. Innovations in science and scenarios for assessment

    SciTech Connect

    Kunkel, Kenneth E.; Moss, Richard; Parris, Adam

    2015-08-29

    Scenarios for the Third National Climate Assessment (NCA3) were produced for physical climate and sea level rise with substantial input from disciplinary and regional experts. These scenarios underwent extensive review and were published as NOAA Technical Reports. For land use/cover and socioeconomic conditions, scenarios already developed by other agencies were specified for use in the NCA3. Efforts to enhance participatory scenario planning as an assessment activity were pursued, but with limited success. Issues and challenges included the timing of availability of scenarios, the need for guidance in use of scenarios, the need for approaches to nest information within multiple scales and sectors, engagement and collaboration of end users in scenario development, and development of integrated scenarios. Future assessments would benefit from an earlier start to scenarios development, the provision of training in addition to guidance documents, new and flexible approaches for nesting information, ongoing engagement and advice from both scientific and end user communities, and the development of consistent and integrated scenarios.

  12. Identifying regions vulnerable to habitat degradation under future irrigation scenarios

    NASA Astrophysics Data System (ADS)

    Terrado, Marta; Sabater, Sergi; Acuña, Vicenç

    2016-11-01

    The loss and degradation of natural habitats is a primary cause of biodiversity decline. The increasing impacts of climate and land use change affect water availability, ultimately decreasing agricultural production. Areas devoted to irrigation have been increased to compensate this reduction, causing habitat and biodiversity losses, especially in regions undergoing severe water stress. These effects might intensify under global change, probably contributing to a decrease in habitat quality. We selected four European river basins across a gradient of water scarcity and irrigation agriculture. The habitat quality in the basins was assessed as a function of habitat suitability and threats under current and future global change scenarios of irrigation. Results revealed that the most threatened regions under future scenarios of global change were among those suffering of water scarcity and with bigger areas devoted to irrigation. Loss of habitat quality reached 10% in terrestrial and 25% in aquatic ecosystems under climate change scenarios involving drier conditions. The aquatic habitats were the most degraded in all scenarios, since they were affected by threats from both the terrestrial and the aquatic parts of the basin. By identifying in advance the regions most vulnerable to habitat and biodiversity loss, our approach can assist decision makers in deciding the conservation actions to be prioritized for mitigation and adaptation to the effects of climate change, particularly front the development of irrigation plans.

  13. In situ measurements of microbially-catalyzed nitrification and nitrate reduction rates in an ephemeral drainage channel receiving water from coalbed natural gas discharge, Powder River Basin, Wyoming, USA

    USGS Publications Warehouse

    Harris, S.H.; Smith, R.L.

    2009-01-01

    Nitrification and nitrate reduction were examined in an ephemeral drainage channel receiving discharge from coalbed natural gas (CBNG) production wells in the Powder River Basin, Wyoming. CBNG co-produced water typically contains dissolved inorganic nitrogen (DIN), primarily as ammonium. In this study, a substantial portion of discharged ammonium was oxidized within 50??m of downstream transport, but speciation was markedly influenced by diel fluctuations in dissolved oxygen (> 300????M). After 300??m of transport, 60% of the initial DIN load had been removed. The effect of benthic nitrogen-cycling processes on stream water chemistry was assessed at 2 locations within the stream channel using acrylic chambers to conduct short-term (2-6??h), in-stream incubations. The highest ambient DIN removal rates (2103????mol N m- 2 h- 1) were found at a location where ammonium concentrations > 350????M. This occurred during light incubations when oxygen concentrations were highest. Nitrification was occurring at the site, however, net accumulation of nitrate and nitrite accounted for < 12% of the ammonium consumed, indicating that other ammonium-consuming processes were also occurring. In dark incubations, nitrite and nitrate consumption were dominant processes, while ammonium was produced rather than consumed. At a downstream location nitrification was not a factor and changes in DIN removal rates were controlled by nitrate reduction, diel fluctuations in oxygen concentration, and availability of electron donor. This study indicates that short-term adaptation of stream channel processes can be effective for removing CBNG DIN loads given sufficient travel distances, but the long-term potential for nitrogen remobilization and nitrogen saturation remain to be determined.

  14. Estimating Policy-Driven Greenhouse Gas Emissions Trajectories in California: The California Greenhouse Gas Inventory Spreadsheet (GHGIS) Model

    SciTech Connect

    Greenblatt, Jeffery B.

    2013-10-10

    A California Greenhouse Gas Inventory Spreadsheet (GHGIS) model was developed to explore the impact of combinations of state policies on state greenhouse gas (GHG) and regional criteria pollutant emissions. The model included representations of all GHG- emitting sectors of the California economy (including those outside the energy sector, such as high global warming potential gases, waste treatment, agriculture and forestry) in varying degrees of detail, and was carefully calibrated using available data and projections from multiple state agencies and other sources. Starting from basic drivers such as population, numbers of households, gross state product, numbers of vehicles, etc., the model calculated energy demands by type (various types of liquid and gaseous hydrocarbon fuels, electricity and hydrogen), and finally calculated emissions of GHGs and three criteria pollutants: reactive organic gases (ROG), nitrogen oxides (NOx), and fine (2.5 ?m) particulate matter (PM2.5). Calculations were generally statewide, but in some sectors, criteria pollutants were also calculated for two regional air basins: the South Coast Air Basin (SCAB) and the San Joaquin Valley (SJV). Three scenarios were developed that attempt to model: (1) all committed policies, (2) additional, uncommitted policy targets and (3) potential technology and market futures. Each scenario received extensive input from state energy planning agencies, in particular the California Air Resources Board. Results indicate that all three scenarios are able to meet the 2020 statewide GHG targets, and by 2030, statewide GHG emissions range from between 208 and 396 MtCO2/yr. However, none of the scenarios are able to meet the 2050 GHG target of 85 MtCO2/yr, with emissions ranging from 188 to 444 MtCO2/yr, so additional policies will need to be developed for California to meet this stringent future target. A full sensitivity study of major scenario assumptions was also performed. In terms of criteria pollutants

  15. The narcissistic scenarios of parenthood.

    PubMed

    Manzano, J; Palacio Espasa, F; Zilkha, N

    1999-06-01

    The authors begin by pointing out that Freud always considered parent-child relations in terms of the child's psychic development and took little account of the parents' experience of the relationship and its psychic effects on them. They recall Freud's distinction between the anaclitic and narcissistic modes of relationship and show how these are unconsciously embodied and enacted in varying proportions in the cases observed in their own clinical practice of therapeutic consultations with parents and young children. After a review of the relevant psychoanalytic literature, the authors present their concept of the narcissistic scenarios of parenthood, which include parental projection on to the child, parental counter-identification, a specific aim and a relational dynamic that is acted out. Depending on the individual situation, the effects may help to structure the developing psyche or, if the narcissistic element is excessive, they may be pathological. The authors consider the literature on the application of psychoanalysis to therapeutic interventions with parents and children, stressing the technical importance of establishing a therapeutic focus. These ideas are illustrated by a detailed case history showing the interaction between a mother and a 4-year-old girl and how it was modified by a short therapy. The differences between interpretation in this situation and in the classical psychoanalytic setting are explained, and the paper ends with some comments on the transmission of psychic elements from generation to generation.

  16. Agricultural Baseline (BL0) scenario

    SciTech Connect

    Davis, Maggie R.; Hellwinckel, Chad M; Eaton, Laurence; Turhollow, Anthony; Brandt, Craig; Langholtz, Matthew H.

    2016-07-13

    Scientific reason for data generation: to serve as the reference case for the BT16 volume 1 agricultural scenarios. The agricultural baseline runs from 2015 through 2040; a starting year of 2014 is used. Date the data set was last modified: 02/12/2016 How each parameter was produced (methods), format, and relationship to other data in the data set: simulation was developed without offering a farmgate price to energy crops or residues (i.e., building on both the USDA 2015 baseline and the agricultural census data (USDA NASS 2014). Data generated are .txt output files by year, simulation identifier, county code (1-3109). Instruments used: POLYSYS (version POLYS2015_V10_alt_JAN22B) supplied by the University of Tennessee APAC The quality assurance and quality control that have been applied: • Check for negative planted area, harvested area, production, yield and cost values. • Check if harvested area exceeds planted area for annuals. • Check FIPS codes.

  17. Renormalization-group improved inflationary scenarios

    NASA Astrophysics Data System (ADS)

    Pozdeeva, E. O.; Vernov, S. Yu.

    2017-03-01

    The possibility to construct an inflationary scenario for renormalization-group improved potentials corresponding to the Higgs sector of quantum field models is investigated. Taking into account quantum corrections to the renormalization-group potential which sums all leading logs of perturbation theory is essential for a successful realization of the inflationary scenario, with very reasonable parameters values. The scalar electrodynamics inflationary scenario thus obtained are seen to be in good agreement with the most recent observational data.

  18. Transportation accident scenarios for commercial spent fuel

    SciTech Connect

    Wilmot, E L

    1981-02-01

    A spectrum of high severity, low probability, transportation accident scenarios involving commercial spent fuel is presented together with mechanisms, pathways and quantities of material that might be released from spent fuel to the environment. These scenarios are based on conclusions from a workshop, conducted in May 1980 to discuss transportation accident scenarios, in which a group of experts reviewed and critiqued available literature relating to spent fuel behavior and cask response in accidents.

  19. Recent and future trends in synthetic greenhouse gas radiative forcing

    NASA Astrophysics Data System (ADS)

    Rigby, M.; Prinn, R. G.; O'Doherty, S.; Miller, B. R.; Ivy, D.; Mühle, J.; Harth, C. M.; Salameh, P. K.; Arnold, T.; Weiss, R. F.; Krummel, P. B.; Steele, L. P.; Fraser, P. J.; Young, D.; Simmonds, P. G.

    2014-04-01

    Atmospheric measurements show that emissions of hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons are now the primary drivers of the positive growth in synthetic greenhouse gas (SGHG) radiative forcing. We infer recent SGHG emissions and examine the impact of future emissions scenarios, with a particular focus on proposals to reduce HFC use under the Montreal Protocol. If these proposals are implemented, overall SGHG radiative forcing could peak at around 355 mW m-2 in 2020, before declining by approximately 26% by 2050, despite continued growth of fully fluorinated greenhouse gas emissions. Compared to "no HFC policy" projections, this amounts to a reduction in radiative forcing of between 50 and 240 mW m-2 by 2050 or a cumulative emissions saving equivalent to 0.5 to 2.8 years of CO2 emissions at current levels. However, more complete reporting of global HFC emissions is required, as less than half of global emissions are currently accounted for.

  20. The Spatial and Temporal Consumptive Water Use Impacts of Rapid Shale Gas Development and Use in Texas

    NASA Astrophysics Data System (ADS)

    Pacsi, A. P.; Allen, D.

    2013-12-01

    Over the past several years, the development of shale gas resources has proceeded rapidly in many areas of the United States, and this shale gas development requires the use of millions of gallons of water, per well, for hydraulic fracturing. Recent life cycle assessments of natural gas from shale formations have calculated the potential for water use reduction when water use is integrated along the entire natural gas supply chain, if the shale gas is used in natural-gas power plants to displace coal-fired electricity generation. Actual grid operation, however, is more complicated and would require both that sufficient unused natural gas generation capacity exists for the displacement of coal-fired power generation and that the natural gas price is low enough that the switching is financially feasible. In addition, water savings, which would occur mainly from a reduction in the cooling water demand at coal-fired power plants, may occur in different regions and at different times than water used in natural gas production. Thus, consumptive water impacts may be spatial and temporally disparate, which is not a consideration in current life-cycle literature. The development of shale gas resources in Texas in August 2008 through December 2009 was chosen as a case study for characterizing this phenomenon since Texas accounted for two-thirds of the shale gas produced in the United States during this period and since the price of natural gas for electricity generation dropped significantly over the episode. Changes to the Texas self-contained electric grid (ERCOT) for a scenario with actual natural gas production and prices was estimated using a constrained grid model, rather than assuming that natural gas generation would displace coal-fired power plant usage. The actual development scenario was compared to an alternative development scenario in which natural gas prices remained elevated throughout the episode. Upstream changes in water consumption from lignite (coal

  1. The Reductive Dehydration of Cellulose by Solid/Gas Reaction with TiCl4 at Low Temperature: A Cheap, Simple, and Green Process for Preparing Anatase Nanoplates and TiO2 /C Composites.

    PubMed

    Plumejeau, Sandrine; Rivallin, Matthieu; Brosillon, Stephan; Ayral, André; Heux, Laurent; Boury, Bruno

    2016-11-21

    Metal oxides and metal oxide/carbon composites are entering the development of new technologies and should therefore to be prepared by sustainable chemistry processes. Therefore, a new aspect of the reactivity of cellulose is presented through its solid/gas reaction with vapour of titanium(IV) chloride in anhydrous conditions at low temperature (80 °C). This reaction leads to two transformations both for cellulose and titanium(IV) chloride. A reductive dehydration of cellulose is seen at the lowest temperature ever reported and results in the formation of a carbonaceous fibrous solid as the only carbon-containing product. Simultaneously, the in situ generation of water leads to the formation of titanium dioxide with an unexpected nanoplate morphology (ca. 50 nm thickness) and a high photocatalytic activity. We present the evidence showing the evolution of the cellulose and the TiO2 nanostructure formation, along with its photocatalytic activity. This low-temperature process avoids any other reagents and is among the greenest processes for the preparation of anatase and also for TiO2 /carbon composites. The anisotropic morphology of TiO2 questions the role of the cellulose on the growing process of these nanoparticles.

  2. MIOSAT Mission Scenario and Design

    NASA Astrophysics Data System (ADS)

    Agostara, C.; Dionisio, C.; Sgroi, G.; di Salvo, A.

    2008-08-01

    MIOSAT ("Mssione Ottica su microSATellite") is a low-cost technological / scientific microsatellite mission for Earth Observation, funded by Italian Space Agency (ASI) and managed by a Group Agreement between Rheinmetall Italia - B.U. Spazio - Contraves as leader and Carlo Gavazzi Space as satellite manufacturer. Several others Italians Companies, SME and Universities are involved in the development team with crucial roles. MIOSAT is a microsatellite weighting around 120 kg and placed in a 525 km altitude sun-synchronuos circular LEO orbit. The microsatellite embarks three innovative optical payloads: Sagnac multi spectral radiometer (IFAC-CNR), Mach Zehender spectrometer (IMM-CNR), high resolution pancromatic camera (Selex Galileo). In addition three technological experiments will be tested in-flight. The first one is an heat pipe based on Marangoni effect with high efficiency. The second is a high accuracy Sun Sensor using COTS components and the last is a GNSS SW receiver that utilizes a Leon2 processor. Finally a new generation of 28% efficiency solar cells will be adopted for the power generation. The platform is highly agile and can tilt along and cross flight direction. The pointing accuracy is in the order of 0,1° for each axe. The pointing determination during images acquisition is <0,02° for the axis normal to the boresight and 0,04° for the boresight. This paper deals with MIOSAT mission scenario and definition, highlighting trade-offs for mission implementation. MIOSAT mission design has been constrained from challenging requirements in terms of satellite mass, mission lifetime, instrument performance, that have implied the utilization of satellite agility capability to improve instruments performance in terms of S/N and resolution. The instruments provide complementary measurements that can be combined in effective ways to exploit new applications in the fields of atmosphere composition analysis, Earth emissions, antropic phenomena, etc. The Mission

  3. From Scenarios to Test Implementations Via Promela

    NASA Astrophysics Data System (ADS)

    Ulrich, Andreas; Alikacem, El-Hachemi; Hallal, Hesham H.; Boroday, Sergiy

    We report on a tool for generating executable concurrent tests from scenarios specified as message sequence charts. The proposed approach features three steps: 1) Deriving a MSC test implementation from a MSC scenario, 2) Mapping the test implementation into a Promela model, 3) Generating executable test scripts in Java. The generation of an intermediate Promela model allows for model-checking to inspect the test implementation for properties like soundness, fault detection power as well as for consistency checking between different test scenarios. Moreover decoupling the executable test scripts from the scenario specification makes it possible to use different backend code generators to support other scripting languages when needed.

  4. National housing and impervious surface scenarios for integrated climate impact assessments.

    PubMed

    Bierwagen, Britta G; Theobald, David M; Pyke, Christopher R; Choate, Anne; Groth, Philip; Thomas, John V; Morefield, Philip

    2010-12-07

    Understanding the impacts of climate change on people and the environment requires an understanding of the dynamics of both climate and land use/land cover changes. A range of future climate scenarios is available for the conterminous United States that have been developed based on widely used international greenhouse gas emissions storylines. Climate scenarios derived from these emissions storylines have not been matched with logically consistent land use/cover maps for the United States. This gap is a critical barrier to conducting effective integrated assessments. This study develops novel national scenarios of housing density and impervious surface cover that are logically consistent with emissions storylines. Analysis of these scenarios suggests that combinations of climate and land use/cover can be important in determining environmental conditions regulated under the Clean Air and Clean Water Acts. We found significant differences in patterns of habitat loss and the distribution of potentially impaired watersheds among scenarios, indicating that compact development patterns can reduce habitat loss and the number of impaired watersheds. These scenarios are also associated with lower global greenhouse gas emissions and, consequently, the potential to reduce both the drivers of anthropogenic climate change and the impacts of changing conditions. The residential housing and impervious surface datasets provide a substantial first step toward comprehensive national land use/land cover scenarios, which have broad applicability for integrated assessments as these data and tools are publicly available.

  5. Traditional formation scenarios fail to explain 4:3 mean motion resonances

    NASA Astrophysics Data System (ADS)

    Rein, Hanno; Payne, Matthew J.; Veras, Dimitri; Ford, Eric B.

    2012-10-01

    At least two multi-planetary systems in a 4:3 mean motion resonance have been found by radial velocity surveys.1 These planets are gas giants and the systems are only stable when protected by a resonance. Additionally the Kepler mission has detected at least four strong candidate planetary systems with a period ratio close to 4:3. This paper investigates traditional dynamical scenarios for the formation of these systems. We systematically study migration scenarios with both N-body and hydrodynamic simulations. We investigate scenarios involving the in situ formation of two planets in resonance. We look at the results from finely tuned planet-planet scattering simulations with gas disc damping. Finally, we investigate a formation scenario involving isolation-mass embryos. Although the combined planet-planet scattering and damping scenario seems promising, none of the above scenarios is successful in forming enough systems in 4:3 resonance with planetary masses similar to the observed ones. This is a negative result but it has important implications for planet formation. Previous studies were successful in forming 2:1 and 3:2 resonances. This is generally believed to be evidence of planet migration. We highlight the main differences between those studies and our failure in forming a 4:3 resonance. We also speculate on more exotic and complicated ideas. These results will guide future investigators towards exploring the above scenarios and alternative mechanisms in a more general framework.

  6. Scenario analysis of fertilizer management practices for N2O mitigation from corn systems in Canada.

    PubMed

    Abalos, Diego; Smith, Ward N; Grant, Brian B; Drury, Craig F; MacKell, Sarah; Wagner-Riddle, Claudia

    2016-12-15

    Effective management of nitrogen (N) fertilizer application by farmers provides great potential for reducing emissions of the potent greenhouse gas nitrous oxide (N2O). However, such potential is rarely achieved because our understanding of what practices (or combination of practices) lead to N2O reductions without compromising crop yields remains far from complete. Using scenario analysis with the process-based model DNDC, this study explored the effects of nine fertilizer practices on N2O emissions and crop yields from two corn production systems in Canada. The scenarios differed in: timing of fertilizer application, fertilizer rate, number of applications, fertilizer type, method of application and use of nitrification/urease inhibitors. Statistical analysis showed that during the initial calibration and validation stages the simulated results had no significant total error or bias compared to measured values, yet grain yield estimations warrant further model improvement. Sidedress fertilizer applications reduced yield-scaled N2O emissions by c. 60% compared to fall fertilization. Nitrification inhibitors further reduced yield-scaled N2O emissions by c. 10%; urease inhibitors had no effect on either N2O emissions or crop productivity. The combined adoption of split fertilizer application with inhibitors at a rate 10% lower than the conventional application rate (i.e. 150kgNha(-1)) was successful, but the benefits were lower than those achieved with single fertilization at sidedress. Our study provides a comprehensive assessment of fertilizer management practices that enables policy development regarding N2O mitigation from agricultural soils in Canada.

  7. Getting to necessary and sufficient-developing accident scenarios for risk assessment

    SciTech Connect

    Mahn, J.A.

    1996-05-01

    This paper presents a simple, systematic approach for developing accident scenarios using generic accident types. Result is a necessary and sufficient set of accident scenarios that can be used to establish the safety envelope for a facility or operation. Us of this approach along with the methodology of SAND95-0320 will yield more consistent accident analyses between facilities and provide a sound basis for allocating limited risk reduction resources.

  8. Modeling the vulnerability of hydroelectricity generation under drought scenarios

    NASA Astrophysics Data System (ADS)

    Yan, E.; Tidwell, V. C.; Bizjack, M.; Espinoza, V.; Jared, A.

    2015-12-01

    Hydroelectricity generation highly relies on in-stream and reservoir water availability. The western US has recently experienced increasingly sever, frequent, and prolonged droughts resulting in significant water availability issues. A large number of hydropower plants in Western Electricity Coordinating Council (WECC) are located in California River Basin and Pacific Northwest River Basin. In supporting the WECC's long-term transmission planning, a drought impact analysis was performed with a series of data and modeling tools. This presentation will demonstrate a case study for California River Basin, which has recently experienced one of the worst droughts in its history. The purpose of this study is to evaluate potential risk for hydroelectricity generation due to projected drought scenarios in the medium-term (through the year of 2030). On the basis of historical droughts and the projected drought year for 2020-2030, three drought scenarios were identified. The hydrologic model was constructed and calibrated to simulate evapotranspiration, streamflow, soil moisture, irrigation as well as reservoir storage and discharge based on various dam operation rules and targets under three drought scenarios. The model also incorporates the projected future water demand in 2030 (e.g. municipal, agricultural, electricity generation). The projected monthly reservoir discharges were used to predict the monthly hydropower generation for hydropower plants with a capacity greater than 50 MW in California River Basin for each drought scenario. The results from this study identify spatial distribution of vulnerable hydropower plants and watersheds as well as the level of potential reduction of electricity generation under various drought scenarios and provide valuable insights into future mitigation strategies and long-term planning.

  9. Uncertainty in Integrated Assessment Scenarios

    SciTech Connect

    Mort Webster

    2005-10-17

    trends from a model for uncertainty projections. The probability distributions of these critical model drivers, and the resulting uncertainty in projections from a range of models, can provide the basis of future emission scenario set designs.

  10. Global emissions of mercury to the atmosphere in 2005 and their 2020 scenarios

    NASA Astrophysics Data System (ADS)

    Pacyna, Jozef M.; Pacyna, Elisabeth G.; Sundseth, Kyrre; Munthe, John; Wilson, Simon; Leaner, Joy

    2010-05-01

    About the three quarters of the total anthropogenic emissions of mercury in the year 2005 estimated to be 1930 tonnes comes from sources where mercury is emitted as a by-product, and the rest is emitted during various applications of mercury. The largest emissions of Hg to the global atmosphere occur from combustion of fossil fuels, mainly coal in utility, industrial, and residential boilers (almost 47 %), followed by artisanal mining (almost 17 %), non-ferrous metal production, including gold production (13.5%) and cement production (about 9.5 %). Doing nothing for the improvement of the Hg emission reductions (so-called Status Quo - SQ scenario) will cause an increase of the emissions in 2020 by almost 100 % compared to the 2020 Extended Emission Control (EXEC) emission reduction scenario. Even larger increase is estimated when the 2020 SQ scenario of Hg emissions is compared with the 2020 Maximum Feasible Technical Reduction (MFTR) emission reduction scenario. The EXEC scenario assumes economic progress at a rate dependent on the future development of industrial technologies and emission control technologies, i.e. mercury-reducing technology currently generally employed throughout Europe and North America would be implemented elsewhere. It further assumes that emissions control measures currently implemented or committed to in Europe to reduce mercury emission to air or water would be implemented around the world. The MFTR scenario assumes implementation of all solutions/ measures leading to the maximum degree of reduction of mercury emissions and its loads discharged to any environment; cost is taken into account but only as a secondary consideration. Emissions of Hg in various industrial sectors, such as cement production and metal manufacturing in the year 2020 can be 2 to 3 times larger if nothing will be done to improve emission control in comparison with the EXEC scenario.

  11. Harm reduction

    PubMed Central

    Normand, Jacques; Li, Jih-Heng; Thomson, Nicholas; Jarlais, Don Des

    2014-01-01

    The “Harm Reduction” session was chaired by Dr. Jacques Normand, Director of the AIDS Research Program of the U.S. National Institute on Drug Abuse. The three presenters (and their presentation topics) were: Dr. Don Des Jarlais (High Coverage Needle/Syringe Programs for People Who Inject Drugs in Low and Middle Income Countries: A Systematic Review), Dr. Nicholas Thomson (Harm Reduction History, Response, and Current Trends in Asia), and Dr. Jih-Heng Li (Harm Reduction Strategies in Taiwan). PMID:25278732

  12. Interplay between oxygen demand reactions and kinetic gas-water transfer in porous media.

    PubMed

    Oswald, Sascha E; Griepentrog, Marco; Schirmer, Mario; Balcke, Gerd U

    2008-08-01

    Gas-water phase transfer associated with the dissolution of trapped gas in porous media is a key process that occurs during pulsed gas sparging operations in contaminated aquifers. Recently, we applied a numerical model that was experimentally validated for abiotic situations, where multi-species kinetic inter-phase mass transfer and dissolved gas transport occurred during pulsed gas penetration-dissolution events [Balcke, G.U., Meenken, S., Hoefer, C. and Oswald, S.E., 2007. Kinetic gas-water transfer and gas accumulation in porous media during pulsed oxygen sparging. Environmental Science & Technology 41(12), 4428-4434]. Here we extend the model by using a reactive term to describe dissolved oxygen demand reactions via the formation of a reaction product, and to study the effects of such an aerobic degradation process on gas-water mass transfer and dissolution of trapped gas in porous media. As a surrogate for microbial oxygen reduction, first-order oxygen demand reactions were based on the measured oxidation of alkaline pyrogallol in column experiments. This reaction allows for adjusting the rate to values close to expected biodegradation rates and detection of the reaction product. The experiments and model consistently demonstrated accelerated oxygen gas-water mass transfer with increasing oxygen demand rates associated with an influence on the partitioning of other gases. Thus, as the oxygen demand accelerates, less gas phase residues, consisting mainly of nitrogen, are observed, which is in general beneficial to the performance of field biosparging operations. Model results additionally predict how oxygen demand influences oxygen mass transfer for a range of biodegradation rates. A typical field case scenario was simulated to illustrate the observed coupling of oxygen consumption and gas bubble dissolution. The model provides a tool to improve understanding of trapped gas behavior in porous media and contributes to a model-assisted biosparging.

  13. Future Forest Cover Change Scenarios with Implications for Landslide Risk: An Example from Buzau Subcarpathians, Romania

    NASA Astrophysics Data System (ADS)

    Malek, Žiga; Boerboom, Luc; Glade, Thomas

    2015-11-01

    This study focuses on future forest cover change in Buzau Subcarpathians, a landslide prone region in Romania. Past and current trends suggest that the area might expect a future increase in deforestation. We developed spatially explicit scenarios until 2040 to analyze the spatial pattern of future forest cover change and potential changes to landslide risk. First, we generated transition probability maps using the weights of evidence method, followed by a cellular automata allocation model. We performed expert interviews, to develop two future forest management scenarios. The Alternative scenario (ALT) was defined by 67 % more deforestation than the Business as Usual scenario (BAU). We integrated the simulated scenarios with a landslide susceptibility map. In both scenarios, most of deforestation was projected in areas where landslides are less likely to occur. Still, 483 (ALT) and 276 (BAU) ha of deforestation were projected on areas with a high-landslide occurrence likelihood. Thus, deforestation could lead to a local-scale increase in landslide risk, in particular near or adjacent to forestry roads. The parallel process of near 10 % forest expansion until 2040 was projected to occur mostly on areas with high-landslide susceptibility. On a regional scale, forest expansion could so result in improved slope stability. We modeled two additional scenarios with an implemented landslide risk policy, excluding high-risk zones. The reduction of deforestation on high-risk areas was achieved without a drastic decrease in the accessibility of the areas. Together with forest expansion, it could therefore be used as a risk reduction strategy.

  14. Future Forest Cover Change Scenarios with Implications for Landslide Risk: An Example from Buzau Subcarpathians, Romania.

    PubMed

    Malek, Žiga; Boerboom, Luc; Glade, Thomas

    2015-11-01

    This study focuses on future forest cover change in Buzau Subcarpathians, a landslide prone region in Romania. Past and current trends suggest that the area might expect a future increase in deforestation. We developed spatially explicit scenarios until 2040 to analyze the spatial pattern of future forest cover change and potential changes to landslide risk. First, we generated transition probability maps using the weights of evidence method, followed by a cellular automata allocation model. We performed expert interviews, to develop two future forest management scenarios. The Alternative scenario (ALT) was defined by 67% more deforestation than the Business as Usual scenario (BAU). We integrated the simulated scenarios with a landslide susceptibility map. In both scenarios, most of deforestation was projected in areas where landslides are less likely to occur. Still, 483 (ALT) and 276 (BAU) ha of deforestation were projected on areas with a high-landslide occurrence likelihood. Thus, deforestation could lead to a local-scale increase in landslide risk, in particular near or adjacent to forestry roads. The parallel process of near 10% forest expansion until 2040 was projected to occur mostly on areas with high-landslide susceptibility. On a regional scale, forest expansion could so result in improved slope stability. We modeled two additional scenarios with an implemented landslide risk policy, excluding high-risk zones. The reduction of deforestation on high-risk areas was achieved without a drastic decrease in the accessibility of the areas. Together with forest expansion, it could therefore be used as a risk reduction strategy.

  15. Evaluation Framework for Dependable Mobile Learning Scenarios

    ERIC Educational Resources Information Center

    Bensassi, Manel; Laroussi, Mona

    2014-01-01

    The goal of the dependability analysis is to predict inconsistencies and to reveal ambiguities and incompleteness in the designed learning scenario. Evaluation, in traditional learning design, is generally planned after the execution of the scenario. In mobile learning, this stage becomes too difficult and expensive to apply due to the complexity…

  16. Scenario Planning at College of Marin.

    ERIC Educational Resources Information Center

    College of Marin, Kentfield, CA.

    This article reviews the scenario planning process implemented at the College of Marin (California). Scenario planning is a creative process in which a group of people who share a common fate develop stories about different ways their future might unfold, and use these stories to make decisions about what path to take. The Global Business Network…

  17. Multimedia Scenario in a Primary School

    ERIC Educational Resources Information Center

    Nulden, Urban; Ward, Bodil

    2002-01-01

    Multimedia as an educational technology tool is used throughout the educational system. In this article we present a research project where multimedia scenario was used to initiate a discussion about Internet use among students and teachers at a primary school. Multimedia scenario is the use of large screen multimedia to initiate and facilitate…

  18. Architectures for Developing Multiuser, Immersive Learning Scenarios

    ERIC Educational Resources Information Center

    Nadolski, Rob J.; Hummel, Hans G. K.; Slootmaker, Aad; van der Vegt, Wim

    2012-01-01

    Multiuser immersive learning scenarios hold strong potential for lifelong learning as they can support the acquisition of higher order skills in an effective, efficient, and attractive way. Existing virtual worlds, game development platforms, and game engines only partly cater for the proliferation of such learning scenarios as they are often…

  19. Molecular Diagnostic Analysis of Outbreak Scenarios

    ERIC Educational Resources Information Center

    Morsink, M. C.; Dekter, H. E.; Dirks-Mulder, A.; van Leeuwen, W. B.

    2012-01-01

    In the current laboratory assignment, technical aspects of the polymerase chain reaction (PCR) are integrated in the context of six different bacterial outbreak scenarios. The "Enterobacterial Repetitive Intergenic Consensus Sequence" (ERIC) PCR was used to analyze different outbreak scenarios. First, groups of 2-4 students determined optimal…

  20. Writing clinical scenarios for clinical science questions.

    PubMed

    Smith, Phil Em; Mucklow, John C

    2016-04-01

    Written knowledge assessments for physicians in training typically involve multiple-choice questions that use a clinical scenario in a single-best-answer format. The Royal College of Physicians Part 1 MRCP(UK) examination includes basic sciences themes that are challenging to assess through a clinical scenario. A realistic clinical setting based on everyday clinical practice and integral to the question is the clearest demonstration that the knowledge being assessed is clinically relevant. However, without special attention to detail, the scenario in a clinical science question can appear redundant or artificial. Reading unnecessary material frustrates candidates and threatens the reputation of the assessment. In this paper we discuss why a clinical scenario is important for basic science questions and offer advice on setting realistic and plausible clinical scenarios for such questions.

  1. Waste Reduction.

    ERIC Educational Resources Information Center

    Bray, Marilyn; And Others

    1996-01-01

    Presents activities that focus on waste reduction in the school and community. The ideas are divided into grade level categories. Sample activities include Techno-Trash, where children use tools to take apart broken appliances or car parts, then reassemble them or build new creations. Activities are suggested for areas including language arts and…

  2. North American Natural Gas Markets. Volume 1

    SciTech Connect

    Not Available

    1988-12-01

    This report sunnnarizes the research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group`s findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models.

  3. Natural Gas Exports from Iran

    EIA Publications

    2012-01-01

    This assessment of the natural gas sector in Iran, with a focus on Iran’s natural gas exports, was prepared pursuant to section 505 (a) of the Iran Threat Reduction and Syria Human Rights Act of 2012 (Public Law No: 112-158). As requested, it includes: (1) an assessment of exports of natural gas from Iran; (2) an identification of the countries that purchase the most natural gas from Iran; (3) an assessment of alternative supplies of natural gas available to those countries; (4) an assessment of the impact a reduction in exports of natural gas from Iran would have on global natural gas supplies and the price of natural gas, especially in countries identified under number (2); and (5) such other information as the Administrator considers appropriate.

  4. Analysis of Long-range Clean Energy Investment Scenarios forEritrea, East Africa

    SciTech Connect

    Van Buskirk, Robert D.

    2004-05-07

    We discuss energy efficiency and renewable energy investments in Eritrea from the strategic long-term economic perspective of meeting Eritrea's sustainable development goals and reducing greenhouse gas emissions. Energy efficiency and renewable energy are potentially important contributors to national productive capital accumulation, enhancement of the environment, expansion of energy services, increases in household standard of living, and improvements in health. In this study we develop a spreadsheet model for calculating some of the national benefits and costs of different levels of investment in energy efficiency and renewable energy. We then present the results of the model in terms of investment demand and investment scenario curves. These curves express the contribution that efficiency and renewable energy projects can make in terms of reduced energy sector operating expenses, and reduced carbon emissions. We provide demand and supply curves that show the rate of return, the cost of carbon emissions reductions vs. supply, and the evolution of the marginal carbon emissions per dollar of GDP for different investment levels and different fuel-type subsectors.

  5. Downscaling climate change scenarios in an urban land use change model.

    PubMed

    Solecki, William D; Oliveri, Charles

    2004-08-01

    The objective of this paper is to describe the process through which climate change scenarios were downscaled in an urban land use model and the results of this experimentation. The land use models (Urban Growth Model [UGM] and the Land Cover Deltatron Model [LCDM]) utilized in the project are part of the SLEUTH program which uses a probabilistic cellular automata protocol. The land use change scenario experiments were developed for the 31-county New York Metropolitan Region (NYMR) of the US Mid-Atlantic Region. The Intergovernmental Panel on Climate Change (IPCC), regional greenhouse gas (GHG) emissions scenarios (Special Report on Emissions Scenarios (SRES) A2 and B2 scenarios) were used to define the narrative scenario conditions of future land use change. The specific research objectives of the land use modeling work involving the SLEUTH program were threefold: (1) Define the projected conversion probabilities and the amount of rural-to-urban land use change for the NYMR as derived by the UGM and LCDM for the years 2020 and 2050, as defined by the pattern of growth for the years 1960-1990; (2) Down-scale the IPCC SRES A2 and B2 scenarios as a narrative that could be translated into alternative growth projections; and, (3) Create two alternative future growth scenarios: A2 scenario which will be associated with more rapid land conversion than found in initial projections, and a B2 scenario which will be associated with a slower level of land conversion. The results of the modeling experiments successfully illustrate the spectrum of possible land use/land cover change scenarios for the years 2020 and 2050. The application of these results into the broader scale climate and health impact study is discussed, as is the general role of land use/land cover change models in climate change studies and associated environmental management strategies.

  6. Impacts, effectiveness and regional inequalities of the GeoMIP G1 to G4 solar radiation management scenarios

    NASA Astrophysics Data System (ADS)

    Yu, Xiaoyong; Moore, John C.; Cui, Xuefeng; Rinke, Annette; Ji, Duoying; Kravitz, Ben; Yoon, Jin-Ho

    2015-06-01

    We evaluate the effectiveness and the regional inequalities of solar radiation management (SRM) in compensating for simultaneous changes in temperature and precipitation caused by increased greenhouse gas concentrations. We analyze the results from Earth System Models under four Geoengineering Model Intercomparison Project (GeoMIP) experiments with a modified form of the Residual Climate Response approach. Each experiment produces 50 model yrs of simulations: 13 models completed experiment G1 (offsetting 4 × CO2 via solar reduction); 12 models completed experiment G2 (offsetting CO2 that increased by 1% per year); 3 models completed experiment G3 (offsetting increasing radiative forcing under RCP4.5 with increasing stratospheric aerosol); and 7 models completed experiment G4 (injection of 5 Tg SO2 a- 1 into the stratosphere). The regional inequalities in temperature and precipitation compensation for experiments G1, G3 and G4 are significantly different from their corresponding noise backgrounds for most models, but for G2 they are not significantly different from noise. Differences in the regional inequalities and the actual effectiveness among the four SRM scenarios are not significant for many models. However, in more than half of the models, the effectiveness for temperature in the solar dimming geoengineering scenarios (G1 and G2) is significantly higher than that in the SO2 geoengineering scenarios (G3 and G4). The effectiveness of the four SRM experiments in compensating for temperature change is considerably higher than for precipitation. The methodology used highlights that a large across-model variation in the treatment of key geoengineering processes (such as stratospheric aerosols) and the quantification of damage caused by climate change creates significant uncertainties in any strategies to achieve optimal compensation effectiveness across different regions.

  7. Scenario Analysis on Global Hydropower Development Paths and Their Contribution to GHG Mitigation Utilizing a Dynamic CGE Model

    NASA Astrophysics Data System (ADS)

    Qian, Z.; Hanasaki, N.; Fujimori, S.; Masaki, Y.; Hijioka, Y.

    2015-12-01

    Currently, hydropower accounts for 16% of the worldwide electricity power supply and 86% of the total renewable electricity energy source due to its low cost, low greenhouse gas (GHG) emission, and relatively high reliability. It is well known that the global hydropower has not yet been fully developed, but the future paths of development and corresponding contribution to GHG mitigation in each region combined with socioeconomic activities are less known. Here we investigated following three questions. How much will hydropower generation increase in the future? Will hydropower generation reach the economically exploitable capability (EEC)? If this will be the case, when and where will it occur? How much GHG emission will be reduced by adding new hydropower? In order to address these questions, we used the AIM/CGE model, a dynamic computable general equilibrium model to quantify the global hydropower development paths and corresponding GHG mitigation contribution for 17 regions in the world associated with a socio-economic scenario termed SSP2. We compared two scenarios with different assumptions on EEC. One is BAU which takes EEC from the report of "World Energy Resources", the other is FIX_BAU which fix EEC at the current hydropower generation amount throughout the research period (2005-2100) or no additional installation of hydropower plants. The comparison between two scenarios indicated that promoting hydropower development contributed to GHG emission reduction globally but the magnitude varied by region. For example we found that in North Africa, hydropower development grew fast because of the rapid economic development, but it reached EEC as soon as in 2040 because of limitation in EEC due to its climatic and geographical conditions. Conversely, in Brazil, it grew steadily and did not reach its abundant EEC. Consequently, GHG mitigation contribution of North Africa is far less than Brazil. This research provides important information for policy makers to

  8. Tritium Emissions Reduction Facility

    SciTech Connect

    Wieneke, R.E.; Bowser, R.P.; Hedley, W.H.; Kissner, T.J.; Lamberger, P.H.; Morgan, F.G.; Van Patten, J.F.; Williams, M.A.

    1988-01-01

    The Tritium Emissions Reduction Facility (TERF) will be a system for the continuous processing of tritium containing gases collected from various operations at Mound. The basis of the system operation will be the oxidation of elemental hydrogen isotopes and organic molecules at elevated temperatures on precious metal catalyst beds, and the adsorption of the resulting oxide (water) on molecular sieve dryers. The TERF will be expected to handle from 400,000 to 1,000,000 curies of tritium per year in the process gas stream and release no more than 200 curies per year to the atmosphere. Consequently, the TERF will need to convert and capture tritium at low concentrations in gas efficiently and reliably. 5 refs., 2 figs.

  9. Combined effects Na and SO2 in flue gas on Mn-Ce/TiO2 catalyst for low temperature selective catalytic reduction of NO by NH3 simulated by Na2SO4 doping

    NASA Astrophysics Data System (ADS)

    Zhou, Aiyi; Yu, Danqing; Yang, Liu; Sheng, Zhongyi

    2016-08-01

    A series of Mn-Ce/TiO2 catalysts were synthesized through an impregnation method and used for low temperature selective catalytic reduction (SCR) of NOx with ammonia (NH3). Na2SO4 was added into the catalyst to simulate the combined effects of alkali metal and SO2 in the flue gas. Experimental results showed that Na2SO4 had strong and fluctuant influence on the activity of Mn-Ce/TiO2, because the effect of Na2SO4 included pore occlusion and sulfation effect simultaneously. When Na2SO4 loading content increased from 0 to 1 wt.%, the SCR activities of Na2SO4-doped catalysts decreased greatly. With further increasing amount of Na2SO4, however, the catalytic activity increased gradually. XRD results showed that Na2SO4 doping could induce the crystallization of MnOx phases, which were also confirmed by TEM and SEM results. BET results showed that the surface areas decreased and a new bimodal mesoporous structure formed gradually with the increasing amount of Na2SO4. XPS results indicated that part of Ce4+ and Mn3+ were transferred to Ce3+ and Mn4+ due to the sulfation after Na2SO4 deposition on the surface of the catalysts. When the doped amounts of Na2SO4 increased, NH3-TPD results showed that the Lewis acid sites decreased and the Brønsted acid sites of Mn-Ce/TiO2 increased quickly, which could be considered as another reason for the observed changes in the catalytic activity. The decreased Mn and Ce atomic concentration, the changes of their oxidative states, and the variation in acidic properties on the surface of Na2SO4-doped catalysts could be the reasons for the fluctuant changes of the catalytic activity.

  10. Aluminum reduction cell electrode

    DOEpatents

    Payne, John R.

    1983-09-20

    The invention is directed to an anode-cathode structure for an electrolytic cell for the reduction of alumina wherein the structure is comprised of a carbon anode assembly which straddles a wedge-shaped refractory hard metal cathode assembly having steeply sloped cathodic surfaces, each cathodic surface being paired in essentially parallel planar relationship with an anode surface. The anode-cathode structure not only takes into account the structural weakness of refractory hard metal materials but also permits the changing of the RHM assembly during operation of the cell. Further, the anode-cathode structure enhances the removal of anode gas from the interpolar gap between the anode and cathode surfaces.

  11. Disruption mitigation by injection of small quantities of noble gas in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Pautasso, G.; Bernert, M.; Dibon, M.; Duval, B.; Dux, R.; Fable, E.; Fuchs, J. C.; Conway, G. D.; Giannone, L.; Gude, A.; Herrmann, A.; Hoelzl, M.; McCarthy, P. J.; Mlynek, A.; Maraschek, M.; Nardon, E.; Papp, G.; Potzel, S.; Rapson, C.; Sieglin, B.; Suttrop, W.; Treutterer, W.; The ASDEX Upgrade Team; The EUROfusion MST1 Team

    2017-01-01

    The most recent experiments of disruption mitigation by massive gas injection in ASDEX Upgrade have concentrated on small—relatively to the past—quantities of noble gas injected, and on the search for the minimum amount of gas necessary for the mitigation of the thermal loads on the divertor and for a significant reduction of the vertical force during the current quench. A scenario for the generation of a long-lived runaway electron beam has been established; this allows the study of runaway current dissipation by moderate quantities of argon injected. This paper presents these recent results and discusses them in the more general context of physical models and extrapolation, and of the open questions, relevant for the realization of the ITER disruption mitigation system.

  12. Scripting Scenarios for the Human Patient Simulator

    NASA Technical Reports Server (NTRS)

    Bacal, Kira; Miller, Robert; Doerr, Harold

    2004-01-01

    The Human Patient Simulator (HPS) is particularly useful in providing scenario-based learning which can be tailored to fit specific scenarios and which can be modified in realtime to enhance the teaching environment. Scripting these scenarios so as to maximize learning requires certain skills, in order to ensure that a change in student performance, understanding, critical thinking, and/or communication skills results. Methods: A "good" scenario can be defined in terms of applicability, learning opportunities, student interest, and clearly associated metrics. Obstacles to such a scenario include a lack of understanding of the applicable environment by the scenario author(s), a desire (common among novices) to cover too many topics, failure to define learning objectives, mutually exclusive or confusing learning objectives, unskilled instructors, poor preparation , disorganized approach, or an inappropriate teaching philosophy (such as "trial by fire" or education through humiliation). Results: Descriptions of several successful teaching programs, used in the military, civilian, and NASA medical environments , will be provided, along with sample scenarios. Discussion: Simulator-based lessons have proven to be a time- and cost-efficient manner by which to educate medical personnel. Particularly when training for medical care in austere environments (pre-hospital, aeromedical transport, International Space Station, military operations), the HPS can enhance the learning experience.

  13. Reduction Corporoplasty

    PubMed Central

    Hakky, Tariq S.; Martinez, Daniel; Yang, Christopher; Carrion, Rafael E.

    2015-01-01

    Objective Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism. Introduction Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. Materials and Methods: We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement. Results The patient tolerated the procedure well and has resolution of his corporal disfigurement. Conclusions Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement. PMID:26005988

  14. Scenarios for low carbon and low water electric power plant ...

    EPA Pesticide Factsheets

    In the water-energy nexus, water use for the electric power sector is critical. Currently, the operational phase of electric power production dominates the electric sector's life cycle withdrawal and consumption of fresh water resources. Water use associated with the fuel cycle and power plant equipment manufacturing phase is substantially lower on a life cycle basis. An outstanding question is: how do regional shifts to lower carbon electric power mixes affect the relative contribution of the upstream life cycle water use? To test this, we examine a range of scenarios comparing a baseline with scenarios of carbon reduction and water use constraints using the MARKet ALlocation (MARKAL) energy systems model with ORD's 2014 U.S. 9-region database (EPAUS9r). The results suggest that moving toward a low carbon and low water electric power mix may increase the non-operational water use. In particular, power plant manufacturing water use for concentrating solar power, and fuel cycle water use for biomass feedstock, could see sharp increases under scenarios of high deployment of these low carbon options. Our analysis addresses the following questions. First, how does moving to a lower carbon electricity generation mix affect the overall regional electric power water use from a life cycle perspective? Second, how does constraining the operational water use for power plants affect the mix, if at all? Third, how does the life cycle water use differ among regions under

  15. Modeling the greenhouse gas budget of straw returning in China: feasibility of mitigation and countermeasures.

    PubMed

    Lu, Fei; Wang, Xiao-Ke; Han, Bing; Ouyang, Zhi-Yun; Zheng, Hua

    2010-05-01

    Straw returning is considered to be one of the most promising carbon sequestration measures in China's cropland. A compound model, namely "Straw Returning and Burning Model-Expansion" (SRBME), was built to estimate the net mitigation potential, economic benefits, and air pollutant reduction of straw returning. Three scenarios, that is, baseline, "full popularization of straw returning (FP)," and "full popularization of straw returning and precision fertilization (FP + P)," were set to reflect popularization of straw returning. The results of the SRBME indicated that (1) compared with the soil carbon sequestration of 13.37 Tg/yr, the net mitigation potentials, which were 6.328 Tg/yr for the FP scenario and 9.179 Tg/yr for the FP + P scenario, had different trends when the full budget of the greenhouse gases was considered; (2) when the feasibility in connection with greenhouse gas (GHG) mitigation, economic benefits, and environmental benefits was taken into consideration, straw returning was feasible in 15 provinces in the FP scenario, with a total net mitigation potential of 7.192 TgCe/yr and the total benefits of CNY 1.473 billion (USD 216.6 million); (3) in the FP + P scenario, with the implementation of precision fertilization, straw returning was feasible in 26 provinces with a total net mitigation potential of 10.39 TgCe/yr and the total benefits of CNY 5.466 billion (USD 803.8 million); (4) any extent of change in the treatment of straw from being burnt to being returned would contribute to air pollution reduction; (5) some countermeasures, such as CH(4) reduction in rice paddies, precision fertilization, financial support, education and propaganda, would promote the feasibility of straw returning as a mitigation measure.

  16. Interactive specification acquisition via scenarios: A proposal

    NASA Technical Reports Server (NTRS)

    Hall, Robert J.

    1992-01-01

    Some reactive systems are most naturally specified by giving large collections of behavior scenarios. These collections not only specify the behavior of the system, but also provide good test suites for validating the implemented system. Due to the complexity of the systems and the number of scenarios, however, it appears that automated assistance is necessary to make this software development process workable. Interactive Specification Acquisition Tool (ISAT) is a proposed interactive system for supporting the acquisition and maintenance of a formal system specification from scenarios, as well as automatic synthesis of control code and automated test generation. This paper discusses the background, motivation, proposed functions, and implementation status of ISAT.

  17. Vocational training: the case scenario workshop.

    PubMed

    Winter-Moore, P H

    2001-01-01

    This article describes the procedure for conducting a workshop for a vocational training group, using six clinical case scenarios harvested from the vocational training group's own experience. During the session, the main group (which includes trainers) breaks up into smaller groups to discuss the management of each case, then a spokesperson presents the management solutions back to the re-assembled larger group: further interaction and discussion then takes place. This article discusses six typical case scenarios from a recent workshop. The case scenario workshop is an exciting way to encourage discussion and interaction with all parties involved.

  18. Common Criteria Based Security Scenario Verification

    NASA Astrophysics Data System (ADS)

    Ohnishi, Atsushi

    Software is required to comply with the laws and standards of software security. However, stakeholders with less concern regarding security can neither describe the behaviour of the system with regard to security nor validate the system’s behaviour when the security function conflicts with usability. Scenarios or use-case specifications are common in requirements elicitation and are useful to analyze the usability of the system from a behavioural point of view. In this paper, the authors propose both (1) a scenario language based on a simple case grammar and (2) a method to verify a scenario with rules based on security evaluation criteria.

  19. Design of climate scenarios with application to agriculture and forestry in central and eastern north America. Final report

    SciTech Connect

    Lamb, P.J.; Richman, M.B.

    1996-06-01

    A research program supported by a USEPA cooperative agreement concentrated on statistical and climatological issues related to designing climate scenarios useful for agricultural and forestry in central and eastern North America. Results can be categorized into the areas of statistical techniques for scenario development and evaluation, climate system research, and data set development. A review of the meteorological use of clustering algorithms and an extensive comparison of cluster methods was undertaken. The last major methodological research was development of target analysis, which allows direct incorporation of climate scenarios into a data reduction and pattern matching algorithm. This was tested successfully on GCM output for realistic climate scenarios.

  20. Overview of the ARkStorm scenario

    USGS Publications Warehouse

    Porter, Keith; Wein, Anne; Alpers, Charles; Baez, Allan; Barnard, Patrick L.; Carter, James; Corsi, Alessandra; Costner, James; Cox, Dale; Das, Tapash; Dettinger, Mike; Done, James; Eadie, Charles; Eymann, Marcia; Ferris, Justin; Gunturi, Prasad; Hughes, Mimi; Jarrett, Robert; Johnson, Laurie; Le-Griffin, Hanh Dam; Mitchell, David; Morman, Suzette; Neiman, Paul; Olsen, Anna; Perry, Suzanne; Plumlee, Geoffrey; Ralph, Martin; Reynolds, David; Rose, Adam; Schaefer, Kathleen; Serakos, Julie; Siembieda, William; Stock, Jonathan; Strong, David; Wing, Ian Sue; Tang, Alex; Thomas, Pete; Topping, Ken; Wills, Chris; Jones, Lucile

    2011-01-01

    The U.S. Geological Survey, Multi Hazards Demonstration Project (MHDP) uses hazards science to improve resiliency of communities to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages emergency planners, businesses, universities, government agencies, and others in preparing for major natural disasters. The project also helps to set research goals and provides decision-making information for loss reduction and improved resiliency. The first public product of the MHDP was the ShakeOut Earthquake Scenario published in May 2008. This detailed depiction of a hypothetical magnitude 7.8 earthquake on the San Andreas Fault in southern California served as the centerpiece of the largest earthquake drill in United States history, involving over 5,000 emergency responders and the participation of over 5.5 million citizens. This document summarizes the next major public project for MHDP, a winter storm scenario called ARkStorm (for Atmospheric River 1,000). Experts have designed a large, scientifically realistic meteorological event followed by an examination of the secondary hazards (for example, landslides and flooding), physical damages to the built environment, and social and economic consequences. The hypothetical storm depicted here would strike the U.S. West Coast and be similar to the intense California winter storms of 1861 and 1862 that left the central valley of California impassible. The storm is estimated to produce precipitation that in many places exceeds levels only experienced on average once every 500 to 1,000 years. Extensive flooding results. In many cases flooding overwhelms the state's flood-protection system, which is typically designed to resist 100- to 200-year runoffs. The Central Valley experiences hypothetical flooding 300 miles long and 20 or more miles wide. Serious flooding also occurs in Orange County, Los Angeles County, San Diego, the San Francisco Bay area, and other

  1. Multi-period natural gas market modeling Applications, stochastic extensions and solution approaches

    NASA Astrophysics Data System (ADS)

    Egging, Rudolf Gerardus

    This dissertation develops deterministic and stochastic multi-period mixed complementarity problems (MCP) for the global natural gas market, as well as solution approaches for large-scale stochastic MCP. The deterministic model is unique in the combination of the level of detail of the actors in the natural gas markets and the transport options, the detailed regional and global coverage, the multi-period approach with endogenous capacity expansions for transportation and storage infrastructure, the seasonal variation in demand and the representation of market power according to Nash-Cournot theory. The model is applied to several scenarios for the natural gas market that cover the formation of a cartel by the members of the Gas Exporting Countries Forum, a low availability of unconventional gas in the United States, and cost reductions in long-distance gas transportation. 1 The results provide insights in how different regions are affected by various developments, in terms of production, consumption, traded volumes, prices and profits of market participants. The stochastic MCP is developed and applied to a global natural gas market problem with four scenarios for a time horizon until 2050 with nineteen regions and containing 78,768 variables. The scenarios vary in the possibility of a gas market cartel formation and varying depletion rates of gas reserves in the major gas importing regions. Outcomes for hedging decisions of market participants show some significant shifts in the timing and location of infrastructure investments, thereby affecting local market situations. A first application of Benders decomposition (BD) is presented to solve a large-scale stochastic MCP for the global gas market with many hundreds of first-stage capacity expansion variables and market players exerting various levels of market power. The largest problem solved successfully using BD contained 47,373 variables of which 763 first-stage variables, however using BD did not result in

  2. FUTURE SCENARIOS OF CHANGE IN WILDLIFE HABITAT

    EPA Science Inventory

    Studies in Pennsylvania, Iowa, California, and Oregon show varying losses of terrestrial wildlife habitat in scenarios based on