Science.gov

Sample records for gas chromatography-electron impact

  1. DETERMINATION OF ACRYLAMIDE IN RAT SERUM AND SCIATIC NERVE BY GAS CHROMATOGRAPHY-ELECTRON-CAPTURE DETECTION

    EPA Science Inventory

    A modified method for the derivatization and analysis of acrylamide as 2-bromopropenamide by gas chromatography/electron capture detection was validated in serum and sciatic nerve from rats. he method was accurate and precise over the concentration range of 2240 to 74700 ppm (w/v...

  2. Detection of trace levels of triclopyr using capillary gas chromatography-electron-capture negative-ion chemical ionization mass spectrometry.

    PubMed

    Begley, P; Foulger, B E

    1988-04-01

    Triclopyr, after esterification, is shown to be a suitable candidate for detection by gas chromatography-electron-capture negative-ion chemical ionization mass spectrometry forming a characteristic carboxylate anion which offers a high detection sensitivity. A detection limit of 70 fg reaching the ionizer is indicated. Low backgrounds and an absence of chemical interferences are shown for vegetation extracts, using a simple method of extraction and derivatisation. A similar behaviour is demonstrated for 2,4-D and 2,4,5-T. PMID:3379116

  3. Rapid direct analysis to discriminate geographic origin of extra virgin olive oils by flash gas chromatography electronic nose and chemometrics.

    PubMed

    Melucci, Dora; Bendini, Alessandra; Tesini, Federica; Barbieri, Sara; Zappi, Alessandro; Vichi, Stefania; Conte, Lanfranco; Gallina Toschi, Tullia

    2016-08-01

    At present, the geographical origin of extra virgin olive oils can be ensured by documented traceability, although chemical analysis may add information that is useful for possible confirmation. This preliminary study investigated the effectiveness of flash gas chromatography electronic nose and multivariate data analysis to perform rapid screening of commercial extra virgin olive oils characterized by a different geographical origin declared in the label. A comparison with solid phase micro extraction coupled to gas chromatography mass spectrometry was also performed. The new method is suitable to verify the geographic origin of extra virgin olive oils based on principal components analysis and discriminant analysis applied to the volatile profile of the headspace as a fingerprint. The selected variables were suitable in discriminating between "100% Italian" and "non-100% Italian" oils. Partial least squares discriminant analysis also allowed prediction of the degree of membership of unknown samples to the classes examined. PMID:26988501

  4. Quantitative Detection of Trace Explosive Vapors by Programmed Temperature Desorption Gas Chromatography-Electron Capture Detector

    PubMed Central

    Field, Christopher R.; Lubrano, Adam; Woytowitz, Morgan; Giordano, Braden C.; Rose-Pehrsson, Susan L.

    2014-01-01

    The direct liquid deposition of solution standards onto sorbent-filled thermal desorption tubes is used for the quantitative analysis of trace explosive vapor samples. The direct liquid deposition method yields a higher fidelity between the analysis of vapor samples and the analysis of solution standards than using separate injection methods for vapors and solutions, i.e., samples collected on vapor collection tubes and standards prepared in solution vials. Additionally, the method can account for instrumentation losses, which makes it ideal for minimizing variability and quantitative trace chemical detection. Gas chromatography with an electron capture detector is an instrumentation configuration sensitive to nitro-energetics, such as TNT and RDX, due to their relatively high electron affinity. However, vapor quantitation of these compounds is difficult without viable vapor standards. Thus, we eliminate the requirement for vapor standards by combining the sensitivity of the instrumentation with a direct liquid deposition protocol to analyze trace explosive vapor samples. PMID:25145416

  5. PARTICLE BEAM LIQUID CHROMATOGRAPHY-ELECTRON IMPACT MASS SPECTROMETRY OF DYES

    EPA Science Inventory

    A liquid chromatograph was interfaced with a triple quadrupole mass spectrometer by means of a particle beam-type interface. he system was used for the analysis and characterization by electron impact mass spectra of a series of commercial dyes. he pure dyes were separated from t...

  6. Determination of acetanilide herbicides in cereal crops using accelerated solvent extraction, solid-phase extraction and gas chromatography-electron capture detector.

    PubMed

    Zhang, Yaping; Yang, Jun; Shi, Ronghua; Su, Qingde; Yao, Li; Li, Panpan

    2011-07-01

    A method was developed to determine eight acetanilide herbicides from cereal crops based on accelerated solvent extraction (ASE) and solid-phase extraction (SPE) followed by gas chromatography-electron capture detector (GC-ECD) analysis. During the ASE process, the effect of four parameters (temperature, static time, static cycles and solvent) on the extraction efficiency was considered and compared with shake-flask extraction method. After extraction with ASE, four SPE tubes (graphitic carbon black/primary secondary amine (GCB/PSA), GCB, Florisil and alumina-N) were assayed for comparison to obtain the best clean-up efficiency. The results show that GCB/PSA cartridge gave the best recoveries and cleanest chromatograms. The analytical process was validated by the analysis of spiked blank samples. Performance characteristics such as linearity, limit of detection (LOD), limit of quantitation (LOQ), precision and recovery were studied. At 0.05 mg/kg spiked level, recoveries and precision values for rice, wheat and maize were 82.3-115.8 and 1.1-13.6%, respectively. For all the herbicides, LOD and LOQ ranged from 0.8 to 1.7 μg/kg and from 2.4 to 5.3 μg/kg, respectively. The proposed analytical methodology was applied for the analysis of the targets in samples; only three herbicides, propyzamid, metolachlor and diflufenican, were detected in two samples. PMID:21656677

  7. [Analysis of organochlorine pesticides and pyrethroid pesticides in vegetables by gas chromatography-electron capture detection coupled with solid-phase extraction using multiwalled carbon nanotubes as adsorbent].

    PubMed

    Zhao, Haixiang; Jia, Yanxia; Ding, Mingyu; Sun, Dajiang; Zhao, Mengbin

    2011-05-01

    A multi-residue analytical method based on solid-phase extraction (SPE) with multiwalled carbon nanotubes (MWCNTs) as adsorbent was developed. The determination of 6 organochlorine pesticides and 7 pyrethroid pesticides in vegetables (including cucumber, cherry tomato, cabbage, lettuce, purple cabbage, leek, shallot and onion) was carried out by gas chromatography-electron capture detection (GC-ECD). The GC-ECD method used two columns (HP-50 and HP-1) and two ECD detectors. The HP-50 column was used for the analysis and the HP-1 column for validation. The clean-up conditions were optimized. The analytes were extracted by acetonitrile, and the extract was cleaned up by the MWCNTs SPE cartridge. The extract was re-dissolved by hexane, eluted with acetone-hexane (7:3, v/v) from the columns. The recoveries were over 70% for the 11 pesticides in the 13 pesticides. The results indicated that the MWCNTs SPE cartridge was efficient for 8 vegetable samples, because it reduced the contamination of the coloring materials to GC-ECD. The experimental results showed the MWCNTs SPE cartridge can adsorb the coloring materials and the eluant was nearly colorless. PMID:21847981

  8. Analysis of organophosphate flame retardants and plasticisers in water by isotope dilution gas chromatography-electron ionisation tandem mass spectrometry.

    PubMed

    Teo, Tiffany L L; McDonald, James A; Coleman, Heather M; Khan, Stuart J

    2015-10-01

    The widespread use of organophosphate flame retardants (PFRs) in commercial products have led to their increased presence in the environment. In this study, a rapid and reliable analytical method was developed for the analysis of five PFRs in water using gas chromatography tandem mass spectrometry (GC-MS/MS) with electron ionisation (EI) and a run time of 13 min. The PFRs investigated were tributyl phosphate (TBP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCP) and triphenyl phosphate (TPP). Solid phase extraction (SPE) was undertaken to extract and concentrate target analytes from aqueous matrices. All water samples were extracted from a volume of 500 mL. Isotopically labelled compounds were used to account for analytical variability and for accurate quantification by isotope dilution. Method recoveries for all compounds were above 80% in all tested water samples. Method detection limits for all target analytes ranged from 0.3 to 24 ng/L in ultrapure water, tap water, seawater, surface water, secondary effluent and swimming pool water. Validation of this method confirmed satisfactory method stability with less than 1% coefficients of variation, verifying that this approach produced good reproducibility. PMID:26078137

  9. Evaluation of gas chromatography - electron ionization - full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis.

    PubMed

    Mol, Hans G J; Tienstra, Marc; Zomer, Paul

    2016-09-01

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS based residue analysis, including the resolving power (15,000 to 120,000 FWHM at m/z 200), scan rate, dynamic range, selectivity, sensitivity, analyte identification, and utility of existing EI-libraries, are assessed and discussed in detail. The optimum acquisition conditions in full scan mode (m/z 50-500) were a resolving power of 60,000 and an automatic-gain-control target value of 3E6. These conditions provided (i) an optimum mass accuracy: within 2 ppm over a wide concentration range, with/without matrix, enabling the use of ±5 ppm mass extraction windows (ii) adequate scan speed: minimum 12 scans/peak, (iii) an intra-scan dynamic range sufficient to achieve LOD/LOQs ≤0.5 pg in fruit/vegetable matrices (corresponding to ≤0.5 μg kg(-1)) for most pesticides. EI-Orbitrap spectra were consistent over a very wide concentration range (5 orders) with good match values against NIST (EI-quadrupole) spectra. The applicability for quantitative residue analysis was verified by validation of 54 pesticides in three matrices (tomato, leek, orange) at 10 and 50 μg/kg. The method involved a QuEChERS-based extraction with a solvent switch into iso-octane, and 1 μL hot splitless injection into the GC-HRMS system. A recovery between 70 and 120% and a repeatability RSD <10% was obtained in most cases. Linearity was demonstrated for the range ≤5-250 μg kg(-1). The pesticides could be identified according to the applicable EU criteria for GC-HRMS (SANTE/11945/2015). GC-EI-full scan Orbitrap HRMS was found to be highly suited for quantitative pesticide residue analysis. The potential of qualitative screening to extend the scope makes it an attractive alternative to GC

  10. An examination of pentafluorobenzoyl derivatization strategies for the analysis of fatty alcohols using gas chromatography/electron capture negative ion chemical ionization-mass spectrometry.

    PubMed

    Bowden, John A; Ford, David A

    2011-05-15

    Gas chromatography/electron capture negative ion chemical ionization-mass spectrometry (GC/ECNICI-MS) combined with pentafluorobenzoyl derivatization (PFBoyl) is frequently used for the sensitive detection of fatty alcohols (FOH). However, this derivatization technique suffers from a lack of established reaction protocols, time-consuming reactions, and the presence of reagent artifacts or unwanted derivatization by-products which can hinder analyte detection. Here, strategies are presented to reduce the problems associated with PFBoyl-derivatization, including (1) the optimization of reaction conditions (derivatization time and temperature) for a variety of PFBoyl-derivatized FOH, (2) an investigation of microwave-accelerated derivatization (MAD) as a rapid alternative heating mechanism for the PFBoyl-derivatization of FOH, and (3) an analysis of an alternative strategy employing a solvent extraction procedure post-derivatization to reduce the detrimental effects commonly associated with PFBoyl derivatization reagents. The optimal reaction conditions for the PFBoyl-derivatization of FOH were determined to be 60°C for 45 min. The investigation in MAD demonstrated the potential of obtaining comparable PFBoyl-derivatizations to those obtained using traditional heating methods, albeit in a reaction time of 3 min. An examination of several solvents for post-derivatization extraction revealed improved relative response factors in comparison to those obtained without solvent extraction. The best solvents for the PFBoyl-FOH extraction, dichloromethane and tert-butyl methyl ether, were also compared to the no solvent extraction samples with standard response curves and PFBoyl-derivatized FOH in Bligh-Dyer extracted rat plasma. PMID:21094100

  11. Use of green coating (cork) in solid-phase microextraction for the determination of organochlorine pesticides in water by gas chromatography-electron capture detection.

    PubMed

    Dias, Adriana Neves; Simão, Vanessa; Merib, Josias; Carasek, Eduardo

    2015-03-01

    A novel method for the determination of organochlorine pesticides in water samples with extraction using cork fiber and analysis by gas chromatography with electron capture detector was developed. Also, the procedure to extract these pesticides with DVB/Car/PDMS fiber was optimized. The optimization of the variables involved in the extraction of organochlorine pesticides using the aforementioned fibers was carried out by multivariate design. The optimum extraction conditions were sample temperature 75 °C, extraction time 60 min and sodium chloride concentration 10% for the cork fiber and sample temperature 50 °C and extraction time 60 min (without salt) for the DVB/Car/PDMS fiber. The quantification limits for the two fibers varied between 1.0 and 10.0 ng L(-1). The linear correlation coefficients were >0.98 for both fibers. The method applied with the use of the cork fiber provided recovery values between 60.3 and 112.7 and RSD≤25.5 (n=3). The extraction efficiency values for the cork and DVB/Car/PDMS fibers were similar. The results show that cork is a promising alternative as a coating for SPME. PMID:25618687

  12. Determination of phenolic flame-retardants in human plasma using solid-phase extraction and gas chromatography-electron-capture mass spectrometry.

    PubMed

    Thomsen, C; Janák, K; Lundanes, E; Becher, G

    2001-01-01

    A method for determination of phenolic flame-retardants in human plasma utilizing solid-phase extraction (SPE) and gas chromatography with electron-capture mass spectrometric detection (GC-ECMS), has been developed. The plasma lipids were decomposed by application of concentrated sulphuric acid directly on the polystyrene-divinylbenzene SPE column. The method has been validated for 2,4,6-tribromophenol (TriBP), pentabromophenol (PeBP), tetrachlorobisphenol-A (TCBP-A) and tetrabromobisphenol-A (TBBP-A) in the concentration range 1.2-25, 0.4-40, 4-200 and 4-200 pg g(-1) plasma, respectively. The average absolute recovery of the analytes ranged from 51 to 85%. Tetrabromo-o-cresol and chlorotribromobisphenol-A were found suitable as internal standards, and the average recovery of the analytes relative to the internal standards was in the range 93-107%. The repeatability of the method was in the range 4-30% relative standard deviation. The estimated detection limits of TriBP, PeBP, TCBP-A and TBBP-A were 0.3, 0.4, 3.0 and 0.8 pg g(-1) plasma, respectively. The method has been used for analysis of plasma samples from potentially occupationally exposed human individuals. PMID:11204209

  13. Optimization of the determination of polybrominated diphenyl ethers in human serum using solid-phase extraction and gas chromatography-electron capture negative ionization mass spectrometry.

    PubMed

    Covaci, Adrian; Voorspoels, Stefan

    2005-12-01

    A simple, rapid, sensitive and reproducible method based on solid-phase extraction (SPE) and acidified silica clean-up was developed for the measurement of 12 polybrominated diphenyl ethers (PBDEs), including BDE 209, and 2,2',4,4',5,5'-hexabromobiphenyl (BB 153) in human serum. Several solid-phase sorbents (Empore C(18), Isolute Phenyl, Isolute ENV+ and OASIS HLB) were tested and it was found that OASIStrade mark HLB (500 mg) gives the highest absolute recoveries (between 64% and 95%, R.S.D.<17%, n=3) for all tested analytes and internal standards. Removal of co-extracted biogenic materials was performed using a 6 ml disposable cartridge containing (from bottom to top) silica impregnated with sulphuric acid, activated silica and anhydrous sodium sulphate. PBDEs and BB 153 were quantified using a gas chromatograph coupled with a mass spectrometer (MS) operated in electron-capture negative ionization mode. The method limits of quantification (LOQ) ranged between 0.2 and 25 pg/ml serum (0.1 and 4 ng/g lipid weight). LOQs were dependent on the analyte levels in procedural blanks which resulted in the highest LOQs for PBDE congeners found in higher concentrations in blanks (e.g. BDE 47, 99 and 209). The use of OASIS HLB SPE cartridge allowed a good method repeatability (within- and between-day precision<12% for all congeners, except for BDE 209<17%, n=3). The method was applied to serum samples from a random Belgian population. The obtained results were within the range of PBDE levels in other non-exposed population from Europe. PMID:16203180

  14. Hollow fiber liquid-liquid-liquid microextraction followed by solid-phase microextraction and in situ derivatization for the determination of chlorophenols by gas chromatography-electron capture detection.

    PubMed

    Saraji, Mohammad; Ghani, Milad

    2015-10-30

    A method based on the combination of hollow fiber liquid-liquid-liquid microextraction and solid-phase microextraction (SPME) followed by gas chromatography-electron capture detection was developed for the determination of chlorophenols in water and wastewater samples. Silica microstructures fabricated on the surface of a stainless steel wire were coated by an organic solvent and used as a SPME fiber. The analytes were extracted through a hollow fiber membrane containing n-decane from sample solution to an alkaline aqueous acceptor phase. They were then extracted and in situ derivatized on the SPME fiber using acetic anhydride. Experimental parameters such as the type of extraction solvent, acceptor phase NaOH concentration, donor phase HCl concentration, the amount of derivatizing reagent, salt concentration, stirring rate and extraction time were investigated and optimized. The precision of the method for the analytes at 0.02-30μgL(-1) concentration level ranged from 7.1 to 10.2% (as intra-day relative standard deviation) and 6.4 to 9.8% (as inter-day relative standard deviation). The linear dynamic ranges were in the interval of 5-500μgL(-1), 0.05-5μgL(-1), 0.02-1μgL(-1) and 0.001-0.5μgL(-1) for 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol, respectively. The enrichment factors were between 432 and 785. The limits of detection were in the range of 0.0004-1.2μgL(-1). Tap water, well water and wastewater samples were also analyzed to evaluate the method capability for real sample analysis. PMID:26411480

  15. Suitability of magnetic particle immunoassay for the analysis of PBDEs in Hawaiian freshwater fish and crabs in comparison with gas chromatography/electron capture detection-ion trap mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A gas chromatograph/electron capture detector-ion trap mass spectrometer (GC/ECD-ITMS) was used for the determination of polybrominated diphenyl ethers (PBDEs) in freshwater fish and crabs. The samples were also analyzed with an enzyme-linked immunosorbent assay (ELISA). GC/ECD-ITMS results showed...

  16. FUEL GAS ENVIRONMENTAL IMPACT

    EPA Science Inventory

    The report gives results of continued investigation and further definition of the potential environmental and economic benefits of integrated coal gasification/gas cleanup/combined gas and steam cycle power plants. Reported refinements in plant operating characteristics lower hea...

  17. A Novel Method for Profiling and Quantifying Short- and Medium-Chain Chlorinated Paraffins in Environmental Samples Using Comprehensive Two-Dimensional Gas Chromatography-Electron Capture Negative Ionization High-Resolution Time-of-Flight Mass Spectrometry.

    PubMed

    Xia, Dan; Gao, Lirong; Zheng, Minghui; Tian, Qichang; Huang, Huiting; Qiao, Lin

    2016-07-19

    Chlorinated paraffins (CPs) are complex technical mixtures containing thousands of isomers. Analyzing CPs in environmental matrices is extremely challenging. CPs have broad, unresolved profiles when analyzed by one-dimensional gas chromatography (GC). Comprehensive two-dimensional GC (GC×GC) can separate CPs with a high degree of orthogonality. A novel method for simultaneously profiling and quantifying short- and medium-chain CPs, using GC×GC coupled with electron capture negative ionization high-resolution time-of-flight mass spectrometry, was developed. The method allowed 48 CP formula congener groups to be analyzed highly selectively in one injection through accurate mass measurements of the [M - Cl](-) ions in full scan mode. The correlation coefficients (R(2)) for the linear calibration curves for different chlorine contents were 0.982 for short-chain CPs and 0.945 for medium-chain CPs. The method was successfully used to determine CPs in sediment and fish samples. By using this method, with enhanced chromatographic separation and high mass resolution, interferences between CP congeners and other organohalogen compounds, such as toxaphene, are minimized. New compounds, with the formulas C9H14Cl6 and C9H13Cl7, were found in sediment and biological samples for the first time. The method was shown to be a powerful tool for the analysis of CPs in environmental samples. PMID:27183176

  18. NPS Gas Gun for Planar Impact Studies

    NASA Astrophysics Data System (ADS)

    Cheong Ho, Chien; Hixson, Robert

    2009-11-01

    The Naval Postgraduate School (NPS) commissioned a Gas Gun for shock wave studies on 9^th October 2009, by performing the first experiment. The Gas Gun is the key element of NPS Shock Wave Research Program within the Physics Department, where well-characterized planar impacts are essential for obtaining high quality data, to characterize a solid material. This first experiment was very successful, and returned key data on the quality of the impact conditions created. The Gas Gun is designed by SANDIA NATIONAL LABORATORIES, and the NPS spent twelve months fabricating the components of the Gas Gun and six months assembling the Gas Gun. Three inch projectile are launched at velocities up to 0.5 km/s, creating high pressure and temperature states that can be used to characterize the fundamental response of relevant materials to dynamic loading. The projectile is launched from a `wrap around' gas breech where helium gas is pressurized to relatively low pressure. This gas is used to accelerate the projectile down a 3m barrel. Upon impact, the speed of the projectile and the flatness of the impact is measured, via a stepped circular pin array circuit. The next stage of development for the Gas Gun is to integrate a Velocity Interferometer System for Any Reflector (VISAR). The VISAR sees all the waves that flow through the target plate as a result of the impact. This is a key diagnostic for determining material properties under dynamic loading conditions.

  19. Greenhouse gas impacts of natural gas: Influence of deployment choice, methane leak rate, and methane GWP

    NASA Astrophysics Data System (ADS)

    Cohan, D. S.

    2015-12-01

    Growing supplies of natural gas have heightened interest in the net impacts of natural gas on climate. Although its production and consumption result in greenhouse gas emissions, natural gas most often substitutes for other fossil fuels whose emission rates may be higher. Because natural gas can be used throughout the sectors of the energy economy, its net impacts on greenhouse gas emissions will depend not only on the leak rates of production and distribution, but also on the use for which natural gas is substituted. Here, we present our estimates of the net greenhouse gas emissions impacts of substituting natural gas for other fossil fuels for five purposes: light-duty vehicles, transit buses, residential heating, electricity generation, and export for electricity generation overseas. Emissions are evaluated on a fuel cycle basis, from production and transport of each fuel through end use combustion, based on recent conditions in the United States. We show that displacement of existing coal-fired electricity and heating oil furnaces yield the largest reductions in emissions. The impact of compressed natural gas replacing petroleum-based vehicles is highly uncertain, with the sign of impact depending on multiple assumptions. Export of liquefied natural gas for electricity yields a moderate amount of emissions reductions. We further show how uncertainties in upstream emission rates for natural gas and in the global warming potential of methane influence the net greenhouse gas impacts. Our presentation will make the case that how natural gas is deployed is crucial to determining how it will impact climate.

  20. Impacts of gas drilling on human and animal health.

    PubMed

    Bamberger, Michelle; Oswald, Robert E

    2012-01-01

    Environmental concerns surrounding drilling for gas are intense due to expansion of shale gas drilling operations. Controversy surrounding the impact of drilling on air and water quality has pitted industry and lease-holders against individuals and groups concerned with environmental protection and public health. Because animals often are exposed continually to air, soil, and groundwater and have more frequent reproductive cycles, animals can be used as sentinels to monitor impacts to human health. This study involved interviews with animal owners who live near gas drilling operations. The findings illustrate which aspects of the drilling process may lead to health problems and suggest modifications that would lessen but not eliminate impacts. Complete evidence regarding health impacts of gas drilling cannot be obtained due to incomplete testing and disclosure of chemicals, and nondisclosure agreements. Without rigorous scientific studies, the gas drilling boom sweeping the world will remain an uncontrolled health experiment on an enormous scale. PMID:22446060

  1. The greenhouse impact of unconventional gas for electricity generation

    NASA Astrophysics Data System (ADS)

    Hultman, Nathan; Rebois, Dylan; Scholten, Michael; Ramig, Christopher

    2011-10-01

    New techniques to extract natural gas from unconventional resources have become economically competitive over the past several years, leading to a rapid and largely unanticipated expansion in natural gas production. The US Energy Information Administration projects that unconventional gas will supply nearly half of US gas production by 2035. In addition, by significantly expanding and diversifying the gas supply internationally, the exploitation of new unconventional gas resources has the potential to reshape energy policy at national and international levels—altering geopolitics and energy security, recasting the economics of energy technology investment decisions, and shifting trends in greenhouse gas (GHG) emissions. In anticipation of this expansion, one of the perceived core advantages of unconventional gas—its relatively moderate GHG impact compared to coal—has recently come under scrutiny. In this paper, we compare the GHG footprints of conventional natural gas, unconventional natural gas (i.e. shale gas that has been produced using the process of hydraulic fracturing, or 'fracking'), and coal in a transparent and consistent way, focusing primarily on the electricity generation sector. We show that for electricity generation the GHG impacts of shale gas are 11% higher than those of conventional gas, and only 56% that of coal for standard assumptions.

  2. Development of impact design methods for ceramic gas turbine components

    NASA Technical Reports Server (NTRS)

    Song, J.; Cuccio, J.; Kington, H.

    1990-01-01

    Impact damage prediction methods are being developed to aid in the design of ceramic gas turbine engine components with improved impact resistance. Two impact damage modes were characterized: local, near the impact site, and structural, usually fast fracture away from the impact site. Local damage to Si3N4 impacted by Si3N4 spherical projectiles consists of ring and/or radial cracks around the impact point. In a mechanistic model being developed, impact damage is characterized as microcrack nucleation and propagation. The extent of damage is measured as volume fraction of microcracks. Model capability is demonstrated by simulating late impact tests. Structural failure is caused by tensile stress during impact exceeding material strength. The EPIC3 code was successfully used to predict blade structural failures in different size particle impacts on radial and axial blades.

  3. Subsurface banding poultry litter impacts greenhouse gas emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact subsurface banding poultry litter (PL) has on greenhouse gas emissions is limited. Thus, a study was conducted in established bermudagrass pastures located in Coastal Plain and Piedmont regions to determine the effects subsurface applying PL has on soil flux using two different band spaci...

  4. Mitigating oil and gas impacts in coastal wetlands

    USGS Publications Warehouse

    Cahoon, Donald R.; Holmes, Joseph C., Jr.

    1989-01-01

    This abstract refers to technical recommendations for avoiding, minimizing, and restoring (i.e., mitigating) drilling site access impacts related to oil and gas activities in coastal wetlands through regulatory review, drawing mostly from the Louisiana experience. The two standard methods used to access wetland drilling locations are canals and roads, both of which require dredging. Each access method impacts wetland values and functions and each has been implicated directly and indirectly in wetland loss by converting marsh habitat to open water or upland habitat and by altering the local hydrologic regime. However, numerous regulatory management techniques exist and should be employed to avoids minimize, and restore canal and road-dump impacts.

  5. Evaluating the income and employment impacts of gas cooling technologies

    SciTech Connect

    Hughes, P.J.; Laitner, S.

    1995-03-01

    The purpose of this study is to estimate the potential employment and income benefits of the emerging market for gas cooling products. The emphasis here is on exports because that is the major opportunity for the U.S. heating, ventilating, and air-conditioning (HVAC) industry. But domestic markets are also important and considered here because without a significant domestic market, it is unlikely that the plant investments, jobs, and income associated with gas cooling exports would be retained within the United States. The prospects for significant gas cooling exports appear promising for a variety of reasons. There is an expanding need for cooling in the developing world, natural gas is widely available, electric infrastructures are over-stressed in many areas, and the cost of building new gas infrastructure is modest compared to the cost of new electric infrastructure. Global gas cooling competition is currently limited, with Japanese and U.S. companies, and their foreign business partners, the only product sources. U.S. manufacturers of HVAC products are well positioned to compete globally, and are already one of the faster growing goods-exporting sectors of the U.S. economy. Net HVAC exports grew by over 800 percent from 1987 to 1992 and currently exceed $2.6 billion annually (ARI 1994). Net gas cooling job and income creation are estimated using an economic input-output model to compare a reference case to a gas cooling scenario. The reference case reflects current policies, practices, and trends with respect to conventional electric cooling technologies. The gas cooling scenario examines the impact of accelerated use of natural gas cooling technologies here and abroad.

  6. Simultaneous quantification of Δ9-tetrahydrocannabinol, 11-hydroxy-Δ9-tetrahydrocannabinol, and 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid in human plasma using two-dimensional gas chromatography, cryofocusing, and electron impact-mass spectrometry

    PubMed Central

    Lowe, Ross H.; Karschner, Erin L.; Schwilke, Eugene W.; Barnes, Allan J.; Huestis, Marilyn A.

    2009-01-01

    A two-dimensional (2D) gas chromatography/electron impact-mass spectrometry (GC/EI-MS) method for simultaneous quantification of Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), and 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in human plasma was developed and validated. The method employs 2D capillary GC and cryofocusing for enhanced resolution and sensitivity. THC, 11-OH-THC, and THCCOOH were extracted by precipitation with acetonitrile followed by solid-phase extraction. GC separation of trimethylsilyl derivatives of analytes was accomplished with two capillary columns in series coupled via a pneumatic Deans switch system. Detection and quantification were accomplished with a bench-top single quadrupole mass spectrometer operated in electron impact-selected ion monitoring mode. Limits of quantification (LOQ) were 0.125, 0.25 and 0.125 ng/mL for THC, 11-OH-THC, and THCCOOH, respectively. Accuracy ranged from 86.0 to 113.0% for all analytes. Intra- and inter-assay precision, as percent relative standard deviation, was less than 14.1% for THC, 11-OH-THC, and THCCOOH. The method was successfully applied to quantification of THC and its 11-OH-THC and THCCOOH metabolites in plasma specimens following controlled administration of THC. PMID:17640656

  7. Identification of a radical formed in the reaction mixtures of ram seminal vesicle microsomes with arachidonic Acid using high performance liquid chromatography-electron spin resonance spectrometry and high performance liquid chromatography-electron spin resonance-mass spectrometry.

    PubMed

    Minakata, Katsuyuki; Iwahashi, Hideo

    2010-03-01

    The reaction of ram seminal vesicle (RSV) microsomes with arachidonic acid (AA) was examined using electron spin resonance (ESR), high performance liquid chromatography-electron spin resonance spectrometry (HPLC-ESR), and high performance liquid chromatography-electron spin resonance-mass spectrometry (HPLC-ESR-MS) combined use of spin trapping technique. A prominent ESR spectrum (alpha(N) = 1.58 mT and alpha(H)beta = 0.26 mT) was observed in the complete reaction mixture of ram seminal vesicle microsomes with arachidonic acid containing 2.0 mg protein/ml ram seminal vesicle (RSV) microsomal suspension, 0.8 mM arachidonic acid, 0.1 M 4-POBN, and 24 mM tris/HCl buffer (pH 7.4). The ESR spectrum was hardly observed for the complete reaction mixture without the RSV microsomes. The formation of the radical appears to be catalyzed by the microsomal components. In the absence of AA, the intensity of the ESR signal decreased to 16 +/- 15% of the complete reaction mixture, suggesting that the radical is derived from AA. For the complete reaction mixture with boiled microsomes, the intensity of the ESR signal decreased to 49 +/- 4% of the complete reaction mixture. The intensity of the ESR signal of the complete reaction mixture with indomethacin decreased to 74 +/- 20% of the complete reaction mixture, suggesting that cyclooxygenese partly participates in the reaction. A peak was detected on the elution profile of HPLC-ESR analysis of the complete reaction mixture. To determine the structure of the peak, an HPLC-ESR-MS analysis was performed. The HPLC-ESR-MS analysis of the peak showed two prominent ions, m/z 266 and m/z 179, suggesting that the peak is a 4-POBN/pentyl radical adduct. An HPLC-ESR analysis of the authentic 4-POBN/pentyl radical adduct comfirmed the identification. PMID:20216946

  8. Transport of dissolved gas and its ecological impact after a gas release from deepwater.

    PubMed

    Wimalaratne, Malinda R; Yapa, Poojitha D; Nakata, Kisaburo; Premathilake, Lakshitha T

    2015-11-15

    Previous models on simulating gas releases in deepwater were not focused on the dissolved component and its impact on water quality. This paper presents a new model developed for simulating the transport/spread of dissolved methane from an underwater release and its impact on dissolved oxygen in ambient water. Methane dissolves into ambient water from gas phase, direct from hydrate phase, and from dissociating hydrates formed earlier. Dissolved methane affects the dissolved oxygen levels in ambient water due to microbial interaction and possible direct absorption of oxygen into methane bubbles. We use new model simulations of Deepspill field experiments to compare with instantaneous profiles which were unpublished until now. The comparisons are very good with a short time lag, but are within the acceptable discrepancy for models for emergency response and contingency planning. Scenario simulations show the effect on dissolved oxygen due to different methane release situations. PMID:26364205

  9. Atmospheric emissions and air quality impacts from natural gas production and use.

    PubMed

    Allen, David T

    2014-01-01

    The US Energy Information Administration projects that hydraulic fracturing of shale formations will become a dominant source of domestic natural gas supply over the next several decades, transforming the energy landscape in the United States. However, the environmental impacts associated with fracking for shale gas have made it controversial. This review examines emissions and impacts of air pollutants associated with shale gas production and use. Emissions and impacts of greenhouse gases, photochemically active air pollutants, and toxic air pollutants are described. In addition to the direct atmospheric impacts of expanded natural gas production, indirect effects are also described. Widespread availability of shale gas can drive down natural gas prices, which, in turn, can impact the use patterns for natural gas. Natural gas production and use in electricity generation are used as a case study for examining these indirect consequences of expanded natural gas availability. PMID:24498952

  10. Impact of Port Fouad offshore gas project on surrounding environment

    SciTech Connect

    Osman, E.N.M.

    1996-11-01

    EIA study was undertaken to assess the impact of the proposed Port Fouad Gas Development Plant on the surrounding environment. An environmental inventory was undertaken to present the baseline data of the surrounding environment. The surrounding environment of the site can be classified as unpolluted and contains significant natural resources such as Ashtoum El-Gamil Protectorate and Lake Manzala in addition to nearby residential areas such as a touristic village to the east and El-Garabaa Village to the west. The effect of the released wastes on the surrounding environment was evaluated and assessed in accordance with the local- and intentional standard specifications for air and water quality.

  11. Impact damage on shielded gas-filled vessels

    NASA Astrophysics Data System (ADS)

    Schäfer, F.; Schneider, E.; Lambert, M.

    2001-10-01

    This paper gives a summary of the findings from impacts on shielded gas-filled cylindrical aluminium alloy (A12219 T851) and titanium alloy (Ti6A14V) pressure vessels that were performed at the Ernst-Mach-Institute in the frame of an ESA contract. The effect of impacts on shielded vessels with projectiles that have a kinetic energy close to the ballistic limit of the combined system of shield and vessel's front wall was investigated. The shields were single Al-bumper plates, unreinforced MLI and MLI reinforced with 2 layers of Betacloth. The threshold diameters that cause leakage from the vessel's front wall were determined experimentally as a function of shield material and shield spacing. For Al-shielded Al- and Ti-vessels, a safety design factor to avoid leakage is presented based on existing Whipple shield equations.

  12. Ozone impacts of natural gas development in the Haynesville Shale.

    PubMed

    Kemball-Cook, Susan; Bar-Ilan, Amnon; Grant, John; Parker, Lynsey; Jung, Jaegun; Santamaria, Wilson; Mathews, Jim; Yarwood, Greg

    2010-12-15

    The Haynesville Shale is a subsurface rock formation located beneath the Northeast Texas/Northwest Louisiana border near Shreveport. This formation is estimated to contain very large recoverable reserves of natural gas, and during the two years since the drilling of the first highly productive wells in 2008, has been the focus of intensive leasing and exploration activity. The development of natural gas resources within the Haynesville Shale is likely to be economically important but may also generate significant emissions of ozone precursors. Using well production data from state regulatory agencies and a review of the available literature, projections of future year Haynesville Shale natural gas production were derived for 2009-2020 for three scenarios corresponding to limited, moderate, and aggressive development. These production estimates were then used to develop an emission inventory for each of the three scenarios. Photochemical modeling of the year 2012 showed increases in 2012 8-h ozone design values of up to 5 ppb within Northeast Texas and Northwest Louisiana resulting from development in the Haynesville Shale. Ozone increases due to Haynesville Shale emissions can affect regions outside Northeast Texas and Northwest Louisiana due to ozone transport. This study evaluates only near-term ozone impacts, but the emission inventory projections indicate that Haynesville emissions may be expected to increase through 2020. PMID:21086985

  13. The determination of PCBs in Rocky Flats Type IV waste sludge by gas chromatography/electron capture detection. Part 2

    SciTech Connect

    Parish, K.J.; Applegate, D.V.; Postlethwait, P.D.; Boparai, A.S.; Reedy, G.T.

    1994-12-01

    Before disposal, radioactive sludge (Type IV) from Rocky Flats Plant (RFP) must be evaluated for polychlorinated biphenyl (PCB) content. The Type IV sludge consists of organic solvents, degreasers, cutting oils, and transuranic (TRU) waste mixed with calcium silicate (MicroCel E{reg_sign} and Oil Dri{reg_sign} to form a grease or paste-like material. For laboratory testing, a nonradioactive simulated Type 17V RFP sludge was prepared at Argonne National Laboratory-East (ANL-E). This sludge has a composition similar to that expected from field samples. In an earlier effort, a simplified method was developed for extraction, cleanup of extract, and determination of PCBs in samples of simulated sludge spiked with Aroclors 1254 and 1260. The simplified method has now been used to determine the presence and quantities of other Aroclors in the simulated sludge, namely, Aroclors 10 1 6, 1221, 1232, 1242, and 1248. The accuracy and precision of the data for these Aroclors were found to be similar to the data for sludges spiked with Aroclors 1254 and 1260. Since actual sludges may vary in composition, the method was also verified by analyzing another source of Type IV simulated sludge, prepared by Argonne National Laboratory-West (ANL-W).

  14. Determination of PCBs in Rocky Flats Type IV waste sludge by gas chromatography/electron capture detection

    SciTech Connect

    Parish, K.J.; Applegate, D.V.; Boparai, A.S.; Reedy, G.T.

    1993-12-01

    Type IV Rocky Flats Plant (RFP) radioactive sludge samples must be evaluated for polychlorinated biphenyl (PCB) content before disposal. The Type IV sludge consists of organic solvents, degreasers, cutting oils, and transuranic (TRU) waste mixed with calcium silicate (MicroCel E{reg_sign}) and Oil Dri{reg_sign} to form a grease or paste-like material. For laboratory studies a nonradioactive simulated Type IV RFP sludge was prepared having a composition similar to that expected from field samples. A simplified method was developed for extraction, purification and analysis of PCBs using samples of simulated sludge spiked with Aroclors 1254 and 1260 (reports provided to Argonne indicated Aroclors 1254 and 1260 as the most likely PCB contaminants in RFP sludge samples). The developed method was compared to the Environmental Protection Agency (EPA) accepted SW-846 method for analysis of PCBs (Method 8081). The accuracy and precision data were found to be similar for the two methods. The developed method was also tested with samples of simulated sludge spiked with Pu (in solid and solution forms). Reduction of radioactivity in final extract versus in the spike sample ranged from a factor of 10{sup 5} to 10{sup 7}.

  15. TRIDENT flyer plate Impact technique: comparison to gas gun plate impact technique

    SciTech Connect

    Koller, Darcie D; Gray, III, George T; Luo, Sheng-Nian

    2009-03-01

    This report describes the details of a series of plate impact experiments that were conducted on a gas gun in an effort to validate a new technique for plate impact using the TRIDENT laser to launch thin flyers. The diagnostics fielded were VISAR and identical samples and impactors were used on both platforms. All experimenters agree that the VISAR results should have agreed between the two experimental platforms. The VISAR results did not agree across the platforms and experimenters offer explanations and implications for this outcome.

  16. Atmospheric Impacts of Marcellus Shale Gas Activities in Southwestern Pennsylvania

    NASA Astrophysics Data System (ADS)

    Presto, A. A.; Lipsky, E. M.; Saleh, R.; Donahue, N. M.; Robinson, A. L.

    2012-12-01

    Pittsburgh and the surrounding regions of southwestern Pennsylvania are subject to intensive natural gas exploration, drilling, and extraction associated with the Marcellus Shale formation. Gas extraction from the shale formation uses techniques of horizontal drilling followed by hydraulic fracturing. There are significant concerns about air pollutant emissions from the development and production of shale gas, especially methane emissions. We have deployed a mobile monitoring unit to investigate the atmospheric impacts of Marcellus Shale gas activities. The mobile sampling platform is a van with an on-board generator, a high-resolution GPS unit, cameras, and instrumentation for measuring methane, criteria gases (SO2, NOx, CO, O3), PM size distributions (scanning mobility particle sizer), black carbon mass (multi-angle absorption photometer), particle-bound polycyclic aromatic hydrocarbons, volatile organic compounds (gas chromatograph with flame ionization detection), and meteorological data. A major advantage of the mobile sampling unit over traditional, stationary monitors is that it allows us to rapidly visit a variety of sites. Sampling at multiple sites allows us to characterize the spatial variability of pollutant concentrations related to Marcellus activity, particularly methane. Data collected from the mobile sampling unit are combined with GIS techniques and dispersion models to map pollutants related to Marcellus Shale operations. The Marcellus Shale gas activities are a major and variable source of methane. The background methane concentration in Pittsburgh is 2.1 +/- 0.2 ppm. However, two southwestern Pennsylvania counties with the highest density of Marcellus Shale wells, Washington and Greene Counties, have many areas of elevated methane concentration. Approximately 11% of the sampled sites in Washington County and nearly 50% of the sampled sites in Greene County have elevated (>2.3 ppm) methane concentrations, compared to 1.5% of sites with elevated

  17. Review of oil and gas exploitation impacts on grizzly bears

    SciTech Connect

    Schallenberger, A.

    1980-01-01

    It is concluded that available information indicates that impacts of oil and gas exploitation should be considered primarily detrimental for grizzly bears in northwestern Montana. Research has shown that grizzlies tend to react strongly to aircraft, especially helicopters. Marked animals previously captured by aircraft show the greatest reaction. Helicopter disturbance may cause den abandonment. Biologists suggest that road development has contributed to a decline in numbers of bears by accelerating habitat loss and increasing hunting and poaching pressure. Use of river valleys for transportation corridors, campsites, and other activities magnifies the effect of human presence by concentrating it in some of the most vulnerable and essential grizzly habitat. Bear-human conflicts may increase as a result of secondary development such as recreation, logging, livestock grazing, and construction of subdivisions.

  18. Prompt Gas Desorption Due to Ion Impact on Accelerator Structures

    NASA Astrophysics Data System (ADS)

    Vijay, Sagar; Seidl, Peter A.; Faltens, Andy; Lidia, Steven M.

    2011-10-01

    The repetition rate and peak current of high intensity ion accelerators for inertial fusion or other applications may be limited under certain conditions by the desorption of gas molecules and atoms due to stray ions striking the accelerator structure. We have measured the prompt yield of atoms in close proximity to the point of impact of the ions on a surface. Using the 300-keV, K+ ion beam of the Neutralized Drift Compression Experiment (NDCX-I), ions strike a metal target in a 5-10 microsecond bunch. The collector of a Bayert-Alpert style ionization gauge is used to detect the local pressure burst several centimeters away. Pressure transients are observed on a micro-second time scale due to the initial burst of desorbed gas, and on a much longer (~1 second) timescale, corresponding to the equilibration of the pressure after many ``bounces'' of atoms in the vacuum chamber. We report on these time dependent pressure measurements, modeling of the pressure transient, and implications for high-intensity ion accelerators. Work performed under auspices of U.S. DOE by LBNL under Contract DE-AC02-05CH1123.

  19. Impact of compression on gas transport in non-woven gas diffusion layers of high temperature polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Froning, Dieter; Yu, Junliang; Gaiselmann, Gerd; Reimer, Uwe; Manke, Ingo; Schmidt, Volker; Lehnert, Werner

    2016-06-01

    Gas transport in non-woven gas diffusion layers of a high-temperature polymer electrolyte fuel cell was calculated with the Lattice Boltzmann method. The underlying micro structure was taken from two sources. A real micro structure was analyzed in the synchrotron under the impact of a compression mask mimicking the channel/rib structure of a flow field. Furthermore a stochastic geometry model based on synchrotron X-ray tomography studies was applied. The effect of compression is included in the stochastic model. Gas transport in these micro structures was simulated and the impact of compression was analyzed. Fiber bundles overlaying the micro structure were identified which affect the homogeneity of the gas flow. There are significant deviations between the impact of compression on effective material properties for this type of gas diffusion layers and the Kozeny-Carman equation.

  20. The Impact of Diffuse Ionized Gas on Emission-line Ratios and Gas Metallicity Measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Yan, Renbin; MaNGA Team

    2016-01-01

    Diffuse Ionized Gas (DIG) is prevalent in star-forming galaxies. Using a sample of galaxies observed by MaNGA, we demonstrate how DIG in star-forming galaxies impact the measurements of emission line ratios, hence the gas-phase metallicity measurements and the interpretation of diagnostic diagrams. We demonstrate that emission line surface brightness (SB) is a reasonably good proxy to separate HII regions from regions dominated by diffuse ionized gas. For spatially-adjacent regions or regions at the same radius, many line ratios change systematically with emission line surface brightness, reflecting a gradual increase of dominance by DIG towards low SB. DIG could significantly bias the measurement of gas metallicity and metallicity gradient. Because DIG tend to have a higher temperature than HII regions, at fixed metallicity DIG displays lower [NII]/[OII] ratios. DIG also show lower [OIII]/[OII] ratios than HII regions, due to extended partially-ionized regions that enhance all low-ionization lines ([NII], [SII], [OII], [OI]). The contamination by DIG is responsible for a substantial portion of the scatter in metallicity measurements. At different surface brightness, line ratios and line ratio gradients can differ systematically. As DIG fraction could change with radius, it can affect the metallicity gradient measurements in systematic ways. The three commonly used strong-line metallicity indicators, R23, [NII]/[OII], O3N2, are all affected in different ways. To make robust metallicity gradient measurements, one has to properly isolate HII regions and correct for DIG contamination. In line ratio diagnostic diagrams, contamination by DIG moves HII regions towards composite or LINER-like regions.

  1. 75 FR 37749 - White River National Forest, Colorado, Oil and Gas Leasing Environmental Impact Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ... Forest Service White River National Forest, Colorado, Oil and Gas Leasing Environmental Impact Statement... Oil and Gas Leasing and Final EIS and Record of Decision. The proposed revision includes the following: Changing what lands will be available for oil and gas leasing; changing or adding stipulations to...

  2. Numerical Simulation of Debris Cloud Propagation inside Gas-Filled Pressure Vessels under Hypervelocity Impact

    NASA Astrophysics Data System (ADS)

    Gai, F. F.; Pang, B. J.; Guan, G. S.

    2009-03-01

    In the paper SPH methods in AUTODYN-2D is used to investigate the characteristics of debris clouds propagation inside the gas-filled pressure vessels for hypervelocity impact on the pressure vessels. The effect of equation of state on debris cloud has been investigated. The numerical simulation performed to analyze the effect of the gas pressure and the impact condition on the propagation of the debris clouds. The result shows that the increase of gas pressure can reduce the damage of the debris clouds' impact on the back wall of vessels when the pressure value is in a certain range. The smaller projectile lead the axial velocity of the debris cloud to stronger deceleration and the debris cloud deceleration is increasing with increased impact velocity. The time of venting begins to occur is related to the "vacuum column" at the direction of impact-axial. The paper studied the effect of impact velocities on gas shock wave.

  3. Impact design methods for ceramic components in gas turbine engines

    NASA Technical Reports Server (NTRS)

    Song, J.; Cuccio, J.; Kington, H.

    1991-01-01

    Methods currently under development to design ceramic turbine components with improved impact resistance are presented. Two different modes of impact damage are identified and characterized, i.e., structural damage and local damage. The entire computation is incorporated into the EPIC computer code. Model capability is demonstrated by simulating instrumented plate impact and particle impact tests.

  4. Economic impact analysis of the oil and natural gas production NESHAP and the natural gas transmission and storage NESHAP. Final report

    SciTech Connect

    Conner, L.

    1999-05-01

    This report evaluates the impact of the final rule for controls of hazardous air pollutants (HAPs) in the Oil and Natural Gas Production industry and the Natural Gas Transmission and Storage industry. Total social costs are estimated by evaluating costs of compliance with the rule and associated market impacts, including: price changes in the natural gas market, adjustments in quantity produced, small entity impacts, and employment impacts.

  5. The Economic Impact of Shale Gas Production in the U.S

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    Energy is important to our daily lives. A price change of one energy type may influence our consumption choices, commodities prices and industry production. For the United States, shale gas is becoming a promising source of natural gas because of the rapid increase in its reserve and production capacity. Shale gas production is projected to be a large proportion of U.S. gas production, as predicted by Energy Information Administration (EIA). However, besides knowing the big picture, more details are needed before characterizing shale gas as a "game changer." It is interesting to address questions like to what extent the production of shale gas could affect other industries' production, stabilize commodities' prices, and what are the impacts on factor payments, capital returns, labor payments and household consumption. In this study, I use a CGE model to measure the impact on industry and the change in social welfare associated with shale gas production.

  6. Shale gas development impacts on surface water quality in Pennsylvania

    PubMed Central

    Olmstead, Sheila M.; Muehlenbachs, Lucija A.; Shih, Jhih-Shyang; Chu, Ziyan; Krupnick, Alan J.

    2013-01-01

    Concern has been raised in the scientific literature about the environmental implications of extracting natural gas from deep shale formations, and published studies suggest that shale gas development may affect local groundwater quality. The potential for surface water quality degradation has been discussed in prior work, although no empirical analysis of this issue has been published. The potential for large-scale surface water quality degradation has affected regulatory approaches to shale gas development in some US states, despite the dearth of evidence. This paper conducts a large-scale examination of the extent to which shale gas development activities affect surface water quality. Focusing on the Marcellus Shale in Pennsylvania, we estimate the effect of shale gas wells and the release of treated shale gas waste by permitted treatment facilities on observed downstream concentrations of chloride (Cl−) and total suspended solids (TSS), controlling for other factors. Results suggest that (i) the treatment of shale gas waste by treatment plants in a watershed raises downstream Cl− concentrations but not TSS concentrations, and (ii) the presence of shale gas wells in a watershed raises downstream TSS concentrations but not Cl− concentrations. These results can inform future voluntary measures taken by shale gas operators and policy approaches taken by regulators to protect surface water quality as the scale of this economically important activity increases. PMID:23479604

  7. Impact of Gas Heating in Inductively Coupled Plasmas

    NASA Technical Reports Server (NTRS)

    Hash, D. B.; Bose, D.; Rao, M. V. V. S.; Cruden, B. A.; Meyyappan, M.; Sharma, S. P.; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Recently it has been recognized that the neutral gas in inductively coupled plasma reactors heats up significantly during processing. The resulting gas density variations across the reactor affect reaction rates, radical densities, plasma characteristics, and uniformity within the reactor. A self-consistent model that couples the plasma generation and transport to the gas flow and heating has been developed and used to study CF4 discharges. A Langmuir probe has been used to measure radial profiles of electron density and temperature. The model predictions agree well with the experimental results. As a result of these comparisons along with the poorer performance of the model without the gas-plasma coupling, the importance of gas heating in plasma processing has been verified.

  8. Social impacts of earthquakes caused by gas extraction in the Province of Groningen, The Netherlands

    SciTech Connect

    Voort, Nick van der Vanclay, Frank

    2015-01-15

    Gas extraction from the Groningen gasfield in the northern Netherlands has led to localised earthquakes which are projected to become more severe. The social impacts experienced by local residents include: damage to property; declining house prices; concerns about the chance of dykes breaking; feelings of anxiety and insecurity; health issues; and anger. These social and emotional impacts are exacerbated by the increasing distrust Groningen people have towards the national government and the gas company, NAM, a partnership between Shell and ExxonMobil. The earthquakes have reopened discussions about the distribution of benefits from gas production and the extent to which benefits are retained locally. Mitigation of the impacts is attempted, but the lack of trust decreases the effectiveness of the mitigation measures. The extent of this experience of previously-unforeseen, unanticipated impacts suggests that a new social and environmental impact assessment needs to be undertaken, and a new Social Impact Management Plan (SIMP) and Impacts and Benefits Agreement (IBA) developed, so that the project can regain its legitimacy and social licence to operate. In addition to conventional gas, this paper has wider relevance for unconventional gas developments, for example shale gas extraction by hydraulic fracturing methods (fracking). - Highlights: • Gas production in Groningen has caused over 1000 earthquakes. • The induced seismicity has caused many social impacts. • Impacts include building damage, reduced house prices, fear and health issues. • Mitigation measures attempted to date are inadequate. • Distrust towards the national government and operator hinders mitigation efforts. • Gas production in Groningen has lost its social licence to operate.

  9. Impact of Unconventional Gas Technology in the Annual Energy Outlook 2000

    EIA Publications

    2000-01-01

    This paper describes the methodology used in the National Energy Modeling System (NEMS) to represent unconventional gas technologies and their impacts on projections in the Annual Energy Outlook 2000 (AEO2000).

  10. THE IMPACT OF MUNICIPAL SOLID WASTE MANAGEMENT ON GREENHOUSE GAS EMISSIONS IN THE UNITED STATES

    EPA Science Inventory

    Technological advancements in United States (U.S.) municipal solid waste (MSW) disposal and a focus on the environmental advantages of integrated MSW management have greatly reduced the environmental impacts of MSW management, including greenhouse gas (GHG) emissions. This study ...

  11. Impacts of Unconventional Gas Technology in the Annual Energy Outlook 2000

    EIA Publications

    2000-01-01

    This paper describes the methodology used in the National Energy Modeling System (NEMS) to represent unconventional gas technologies and their impacts on projections in the Annual Energy Outlook 2000 (AEO2000).

  12. Impact design methods for ceramic components in gas turbine engines

    SciTech Connect

    Song, J.; Cuccio, J.; Kington, H. . Garrett Auxilliary Power Division)

    1993-01-01

    Garrett Auxiliary Power Division of Allied-Signal Aerospace Company is developing methods to design ceramic turbine components with improved impact resistance. In an ongoing research effort under the DOE/NASA-funded Advanced Turbine Technology Applications Project (ATTAP), two different modes of impact damage have been identified and characterized: local damage and structural damage. Local impact damage to Si[sub 3]N[sub 4] impacted by spherical projectiles usually takes the form of ring and/or radial cracks in the vicinity of the impact point. Baseline data from Si[sub 3]N[sub 4] test bars impacted by 1.588-mm (0.0625-in.) diameter NC-132 projectiles indicates the critical velocity at which the probability of detecting surface cracks is 50 percent equaled 130 m/s (426 ft/sec). A microphysics-based model that assumes damage to be in the form of microcracks has been developed to predict local impact damage. Local stress and strain determine microcrack nucleation and propagation, which in turn alter local stress and strain through modulus degradation. Material damage is quantified by a damage parameter related to the volume fraction of microcracks. The entire computation has been incorporated into the EPIC computer code. Model capability is being demonstrated by simulating instrumented plate impact and particle impact tests. Structural impact damage usually occurs in the form of fast fracture caused by bending stresses that exceed the material strength. The EPIC code has been successfully used to predict radial and axial blade failures from impacts by various size particles. This method is also being used in conjunction with Taguchi experimental methods to investigate the effects of design parameters on turbine blade impact resistance. It has been shown that significant improvement in impact resistance can be achieved by using the configuration recommended by Taguchi methods.

  13. Socioeconomic impacts of outer continental shelf oil and gas development; a bibliography

    USGS Publications Warehouse

    Pattison, Malka L.

    1977-01-01

    The bibliography lists reports which are concerned primarily with the socioeconomic impacts of OCS oil and gas development or which, although not primarily concerned with such impacts, include sections that contain significant discussion of them. Several of the cited reports do not address socioeconomic issues directly, but have been included because of their value in providing a broad picture of OCS oil and gas development and the associated terminology and/or techical aspects. (Sinha - OEIS)

  14. Integrated Analysis of Greenhouse Gas Mitigation Options and Related Impacts

    EPA Science Inventory

    Increased concerns over air pollution (combined with detrimental health effects) and climate change have called for more stringent emission reduction strategies for criteria air pollutants and greenhouse gas emissions. However, stringent regulatory policies can possibly have a...

  15. Impact of tillage and fertilizer application method on gas emissions in a corn cropping system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tillage and fertilization practices used in row crop production are thought to alter greenhouse gas emissions from soil. This study was conducted to determine the impact of fertilizer sources, land management practices, and fertilizer placement methods on greenhouse gas emissions. A new prototype i...

  16. Disintegration of planar liquid film impacted by two-dimensional gas jets

    NASA Astrophysics Data System (ADS)

    Mehring, C.; Sirignano, W. A.

    2003-05-01

    The distortion and break-up of a thin planar liquid film impacted by two gas jets while discharging from a twin-fluid atomizer is studied numerically. The gas momentum vector has components normal and parallel to the liquid stream. Viscosity and compressibility are neglected in both the liquid phase and the gas phase. The reduced-dimension (lubrication) approximation is employed to describe the nonlinear distortion and breakup of the thin film. The gas-phase dynamics are modelled by using a boundary-element-method formulation. For the considered parameter range and for a given energy expenditure, direct modulation of liquid-phase velocities at the nozzle exit is found to be more effective in causing film rupture than indirect modulation via adjacent impacting gas jets. In the former case, dilational film modulation results in shorter breakup lengths than sinuous modulation. On the other hand, for gas-jet modulated films, sinuous mode forcing is more effective than dilational forcing for the same energy input. Co-flowing gas streams significantly alter wavelengths and amplitudes of film disturbances generated by direct film modulation. Large ratios of gas-jet momentum to liquid-film momentum result in "immediate" film rupture in response to the dynamics of the impacting gas jets, whereas for lower ratios films disintegration occurs further downstream after continuous growth of the initial disturbances. Film distortion is characterized by the formation of fluid blobs or long band-like films depending on Weber number values and density ratio.

  17. Hydraulic fracturing for natural gas: impact on health and environment.

    PubMed

    Carpenter, David O

    2016-03-01

    Shale deposits exist in many parts of the world and contain relatively large amounts of natural gas and oil. Recent technological developments in the process of horizontal hydraulic fracturing (hydrofracturing or fracking) have suddenly made it economically feasible to extract natural gas from shale. While natural gas is a much cleaner burning fuel than coal, there are a number of significant threats to human health from the extraction process as currently practiced. There are immediate threats to health resulting from air pollution from volatile organic compounds, which contain carcinogens such as benzene and ethyl-benzene, and which have adverse neurologic and respiratory effects. Hydrogen sulfide, a component of natural gas, is a potent neuro- and respiratory toxin. In addition, levels of formaldehyde are elevated around fracking sites due to truck traffic and conversion of methane to formaldehyde by sunlight. There are major concerns about water contamination because the chemicals used can get into both ground and surface water. Much of the produced water (up to 40% of what is injected) comes back out of the gas well with significant radioactivity because radium in subsurface rock is relatively water soluble. There are significant long-term threats beyond cancer, including exacerbation of climate change due to the release of methane into the atmosphere, and increased earthquake activity due to disruption of subsurface tectonic plates. While fracking for natural gas has significant economic benefits, and while natural gas is theoretically a better fossil fuel as compared to coal and oil, current fracking practices pose significant adverse health effects to workers and near-by residents. The health of the public should not be compromized simply for the economic benefits to the industry. PMID:26943595

  18. Environmental baseline conditions for impact assessment of unconventional gas exploitation: the G-Baseline project

    NASA Astrophysics Data System (ADS)

    Kloppmann, Wolfram; Mayer, Berhard; Millot, Romain; Parker, Beth L.; Gaucher, Eric; Clarkson, Christopher R.; Cherry, John A.; Humez, Pauline; Cahill, Aaron

    2015-04-01

    A major scientific challenge and an indispensible prerequisite for environmental impact assessment in the context of unconventional gas development is the determination of the baseline conditions against which potential environmental impacts on shallow freshwater resources can be accurately and quantitatively tested. Groundwater and surface water resources overlying the low-permeability hydrocarbon host rocks containing shale gas may be impacted to different extents by naturally occurring saline fluids and by natural gas emanations. Baseline assessments in areas of previous conventional hydrocarbon production may also reveal anthropogenic impacts from these activities not related to unconventional gas development. Once unconventional gas exploitation has started, the baseline may be irrevocably lost by the intricate superposition of geogenic and potential anthropogenic contamination by stray gas, formation waters and chemicals used during hydraulic fracturing. The objective of the Franco-Canadian NSERC-ANR project G-Baseline is to develop an innovative and comprehensive methodology of geochemical and isotopic characterization of the environmental baseline for water and gas samples from all three essential zones: (1) the production zone, including flowback waters, (2) the intermediate zone comprised of overlying formations, and (3) shallow aquifers and surface water systems where contamination may result from diverse natural or human impacts. The outcome will be the establishment of a methodology based on innovative tracer and monitoring techniques, including traditional and non-traditional isotopes (C, H, O, S, B, Sr, Cl, Br, N, U, Li, Cu, Zn, CSIA...) for detecting, quantifying and modeling of potential leakage of stray gas and of saline formation water mixed with flowback fluids into fresh groundwater resources and surface waters taking into account the pathways and mechanisms of fluid and gas migration. Here we present an outline of the project as well as first

  19. Wellbeing impacts of city policies for reducing greenhouse gas emissions.

    PubMed

    Hiscock, Rosemary; Mudu, Pierpaolo; Braubach, Matthias; Martuzzi, Marco; Perez, Laura; Sabel, Clive

    2014-12-01

    To mitigate climate change, city authorities are developing policies in areas such as transportation, housing and energy use, to reduce greenhouse gas emissions. In addition to their effects on greenhouse gas emissions, these policies are likely to have consequences for the wellbeing of their populations for example through changes in opportunities to take physical exercise. In order to explore the potential consequences for wellbeing, we first explore what 'wellbeing' is and how it can be operationalised for urban planners. In this paper, we illustrate how wellbeing can be divided into objective and subjective aspects which can be measured quantitatively; our review of measures informs the development of a theoretical model linking wellbeing to policies which cities use to reduce greenhouse gas emissions. Finally, we discuss the extent to which the links proposed in the conceptual model are supported by the literature and how cities can assess wellbeing implications of policies. PMID:25464129

  20. Impact of Adsorption on Gas Transport in Nanopores

    NASA Astrophysics Data System (ADS)

    Wu, Tianhao; Zhang, Dongxiao

    2016-03-01

    Given the complex nature of the interaction between gas and solid atoms, the development of nanoscale science and technology has engendered a need for further understanding of gas transport behavior through nanopores and more tractable models for large-scale simulations. In the present paper, we utilize molecular dynamic simulations to demonstrate the behavior of gas flow under the influence of adsorption in nano-channels consisting of illite and graphene, respectively. The results indicate that velocity oscillation exists along the cross-section of the nano-channel, and the total mass flow could be either enhanced or reduced depending on variations in adsorption under different conditions. The mechanisms can be explained by the extra average perturbation stress arising from density oscillation via the novel perturbation model for micro-scale simulation, and approximated via the novel dual-region model for macro-scale simulation, which leads to a more accurate permeability correction model for industrial applications than is currently available.

  1. Wellbeing Impacts of City Policies for Reducing Greenhouse Gas Emissions

    PubMed Central

    Hiscock, Rosemary; Mudu, Pierpaolo; Braubach, Matthias; Martuzzi, Marco; Perez, Laura; Sabel, Clive

    2014-01-01

    To mitigate climate change, city authorities are developing policies in areas such as transportation, housing and energy use, to reduce greenhouse gas emissions. In addition to their effects on greenhouse gas emissions, these policies are likely to have consequences for the wellbeing of their populations for example through changes in opportunities to take physical exercise. In order to explore the potential consequences for wellbeing, we first explore what ‘wellbeing’ is and how it can be operationalized for urban planners. In this paper, we illustrate how wellbeing can be divided into objective and subjective aspects which can be measured quantitatively; our review of measures informs the development of a theoretical model linking wellbeing to policies which cities use to reduce greenhouse gas emissions. Finally, we discuss the extent to which the links proposed in the conceptual model are supported by the literature and how cities can assess wellbeing implications of policies. PMID:25464129

  2. Limited impact on decadal-scale climate change from increased use of natural gas.

    PubMed

    McJeon, Haewon; Edmonds, Jae; Bauer, Nico; Clarke, Leon; Fisher, Brian; Flannery, Brian P; Hilaire, Jérôme; Krey, Volker; Marangoni, Giacomo; Mi, Raymond; Riahi, Keywan; Rogner, Holger; Tavoni, Massimo

    2014-10-23

    The most important energy development of the past decade has been the wide deployment of hydraulic fracturing technologies that enable the production of previously uneconomic shale gas resources in North America. If these advanced gas production technologies were to be deployed globally, the energy market could see a large influx of economically competitive unconventional gas resources. The climate implications of such abundant natural gas have been hotly debated. Some researchers have observed that abundant natural gas substituting for coal could reduce carbon dioxide (CO2) emissions. Others have reported that the non-CO2 greenhouse gas emissions associated with shale gas production make its lifecycle emissions higher than those of coal. Assessment of the full impact of abundant gas on climate change requires an integrated approach to the global energy-economy-climate systems, but the literature has been limited in either its geographic scope or its coverage of greenhouse gases. Here we show that market-driven increases in global supplies of unconventional natural gas do not discernibly reduce the trajectory of greenhouse gas emissions or climate forcing. Our results, based on simulations from five state-of-the-art integrated assessment models of energy-economy-climate systems independently forced by an abundant gas scenario, project large additional natural gas consumption of up to +170 per cent by 2050. The impact on CO2 emissions, however, is found to be much smaller (from -2 per cent to +11 per cent), and a majority of the models reported a small increase in climate forcing (from -0.3 per cent to +7 per cent) associated with the increased use of abundant gas. Our results show that although market penetration of globally abundant gas may substantially change the future energy system, it is not necessarily an effective substitute for climate change mitigation policy. PMID:25317557

  3. Impacts of Imported Liquefied Natural Gas on Residential Appliance Components: Literature Review

    SciTech Connect

    Lekov, Alex; Sturges, Andy; Wong-Parodi, Gabrielle

    2009-12-09

    An increasing share of natural gas supplies distributed to residential appliances in the U.S. may come from liquefied natural gas (LNG) imports. The imported gas will be of a higher Wobbe number than domestic gas, and there is concern that it could produce more pollutant emissions at the point of use. This report will review recently undertaken studies, some of which have observed substantial effects on various appliances when operated on different mixtures of imported LNG. While we will summarize findings of major studies, we will not try to characterize broad effects of LNG, but describe how different components of the appliance itself will be affected by imported LNG. This paper considers how the operation of each major component of the gas appliances may be impacted by a switch to LNG, and how this local impact may affect overall safety, performance and pollutant emissions.

  4. Life cycle greenhouse gas impacts of grassland management practice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass from conservation and dedicated grasslands could be an important feedstock for biofuels. Estimating the carbon (C) intensity of biofuel production pathways is important in order to meet greenhouse gas (GHG) targets set by government policy. Management decisions made during feedstock producti...

  5. Energy Market Impacts of Alternative Greenhouse Gas Intensity Reduction Goals

    EIA Publications

    2006-01-01

    This report responds to a request from Senator Ken Salazar that the Energy Information Administration (EIA) analyze the impacts of implementing alternative variants of an emissions cap-and-trade program for greenhouse gases (GHGs).

  6. The impact of corrosion on the oil and gas industry

    SciTech Connect

    Kermani, M.B.; Harrop, D.

    1996-08-01

    The impact of corrosion on the oil industry has been viewed in terms of its effect on both capital and operational expenditures (CAPEX and OPEX) and health, safety, and the environment (HSE). To fight against the high cost and the impact of corrosion within the oil industry, an overview of topical research and engineering activities is presented. This covers corrosion and metallurgy issues related to drilling, production, transportation, and refinery activities.

  7. Comparing the Ecological Impacts of Wind and Oil & Gas Development: A Landscape Scale Assessment

    PubMed Central

    Jones, Nathan F.; Pejchar, Liba

    2013-01-01

    Energy production in the United States is in transition as the demand for clean and domestic power increases. Wind energy offers the benefit of reduced emissions, yet, like oil and natural gas, it also contributes to energy sprawl. We used a diverse set of indicators to quantify the ecological impacts of oil, natural gas, and wind energy development in Colorado and Wyoming. Aerial imagery was supplemented with empirical data to estimate habitat loss, fragmentation, potential for wildlife mortality, susceptibility to invasion, biomass carbon lost, and water resources. To quantify these impacts we digitized the land-use footprint within 375 plots, stratified by energy type. We quantified the change in impacts per unit area and per unit energy produced, compared wind energy to oil and gas, and compared landscapes with and without energy development. We found substantial differences in impacts between energy types for most indicators, although the magnitude and direction of the differences varied. Oil and gas generally resulted in greater impacts per unit area but fewer impacts per unit energy compared with wind. Biologically important and policy-relevant outcomes of this study include: 1) regardless of energy type, underlying land-use matters and development in already disturbed areas resulted in fewer total impacts; 2) the number and source of potential mortality varied between energy types, however, the lack of robust mortality data limits our ability to use this information to estimate and mitigate impacts; and 3) per unit energy produced, oil and gas extraction was less impactful on an annual basis but is likely to have a much larger cumulative footprint than wind energy over time. This rapid evaluation of landscape-scale energy development impacts could be replicated in other regions, and our specific findings can help meet the challenge of balancing land conservation with society’s demand for energy. PMID:24312296

  8. Impact of airway gas exchange on the multiple inert gas elimination technique: theory.

    PubMed

    Anderson, Joseph C; Hlastala, Michael P

    2010-03-01

    The multiple inert gas elimination technique (MIGET) provides a method for estimating alveolar gas exchange efficiency. Six soluble inert gases are infused into a peripheral vein. Measurements of these gases in breath, arterial blood, and venous blood are interpreted using a mathematical model of alveolar gas exchange (MIGET model) that neglects airway gas exchange. A mathematical model describing airway and alveolar gas exchange predicts that two of these gases, ether and acetone, exchange primarily within the airways. To determine the effect of airway gas exchange on the MIGET, we selected two additional gases, toluene and m-dichlorobenzene, that have the same blood solubility as ether and acetone and minimize airway gas exchange via their low water solubility. The airway-alveolar gas exchange model simulated the exchange of toluene, m-dichlorobenzene, and the six MIGET gases under multiple conditions of alveolar ventilation-to-perfusion, VA/Q, heterogeneity. We increased the importance of airway gas exchange by changing bronchial blood flow, Qbr. From these simulations, we calculated the excretion and retention of the eight inert gases and divided the results into two groups: (1) the standard MIGET gases which included acetone and ether and (2) the modified MIGET gases which included toluene and m-dichlorobenzene. The MIGET mathematical model predicted distributions of ventilation and perfusion for each grouping of gases and multiple perturbations of VA/Q and Qbr. Using the modified MIGET gases, MIGET predicted a smaller dead space fraction, greater mean VA, greater log(SDVA), and more closely matched the imposed VA distribution than that using the standard MIGET gases. Perfusion distributions were relatively unaffected. PMID:20336837

  9. Impact of Airway Gas Exchange on the Multiple Inert Gas Elimination Technique: Theory

    PubMed Central

    Anderson, Joseph C.; Hlastala, Michael P.

    2011-01-01

    The multiple inert gas elimination technique (MIGET) provides a method for estimating alveolar gas exchange efficiency. Six soluble inert gases are infused into a peripheral vein. Measurements of these gases in breath, arterial blood, and venous blood are interpreted using a mathematical model of alveolar gas exchange (MIGET model) that neglects airway gas exchange. A mathematical model describing airway and alveolar gas exchange predicts that two of these gases, ether and acetone, exchange primarily within the airways. To determine the effect of airway gas exchange on the MIGET, we selected two additional gases, toluene and m-dichlorobenzene, that have the same blood solubility as ether and acetone and minimize airway gas exchange via their low water solubility. The airway-alveolar gas exchange model simulated the exchange of toluene, m-dichlorobenzene, and the six MIGET gases under multiple conditions of alveolar ventilation-to-perfusion, V̇A/Q̇, heterogeneity. We increased the importance of airway gas exchange by changing bronchial blood flow, Q̇br. From these simulations, we calculated the excretion and retention of the eight inert gases and divided the results into two groups: 1) the standard MIGET gases which included acetone and ether and 2) the modified MIGET gases which included toluene and m-dichlorobenzene. The MIGET mathematical model predicted distributions of ventilation and perfusion for each grouping of gases and multiple perturbations of V̇A/Q̇ and Q̇br. Using the modified MIGET gases, MIGET predicted a smaller dead space fraction, greater mean V̇A, greater log(SDVA), and more closely matched the imposed V̇A distribution than that using the standard MIGET gases. Perfusion distributions were relatively unaffected. PMID:20336837

  10. 75 FR 51839 - Environmental Impact Statement for Oil and Gas Development Activities on the Uintah and Ouray...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... Bureau of Indian Affairs Environmental Impact Statement for Oil and Gas Development Activities on the... Environmental Impact Statement (EIS) that evaluates proposed oil and gas development activities on the Uintah... oil and/or natural gas wells over the next 15 years, with a life- of-project of 40 years. In...

  11. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2014-05-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and potentially in Europe, extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus in Australia. The two sources of methane share many of the same characteristics, with hydraulic fracturing generally (but not always) required to extract coal seam gas also. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction and hydraulic fracturing on surface and groundwater resources may be potentially of more concern for coal seam gas than for shale gas. To determine the potential for coal seam gas extraction (and coal mining more generally) to impact on water resources and water-related assets in Australia, the Commonwealth Government has recently established an Independent Expert Scientific Committee (the IESC) to provide advice to Commonwealth and State Government regulators on potential water-related impacts of coal seam gas and large coal mining developments. The IESC has in turn implemented a program of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment can be defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion, with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are now being carried out across large portions of eastern Australia which are underlain by coal reserves. Further details of the program can be found at http://www.environment.gov.au/coal-seam-gas-mining/bioregional-assessments.html. This presentation will provide an overview of the issues related to the impacts of coal seam gas extraction on surface and groundwater resources and water-related assets in Australia. The

  12. Impact of Adsorption on Gas Transport in Nanopores

    PubMed Central

    Wu, Tianhao; Zhang, Dongxiao

    2016-01-01

    Given the complex nature of the interaction between gas and solid atoms, the development of nanoscale science and technology has engendered a need for further understanding of gas transport behavior through nanopores and more tractable models for large-scale simulations. In the present paper, we utilize molecular dynamic simulations to demonstrate the behavior of gas flow under the influence of adsorption in nano-channels consisting of illite and graphene, respectively. The results indicate that velocity oscillation exists along the cross-section of the nano-channel, and the total mass flow could be either enhanced or reduced depending on variations in adsorption under different conditions. The mechanisms can be explained by the extra average perturbation stress arising from density oscillation via the novel perturbation model for micro-scale simulation, and approximated via the novel dual-region model for macro-scale simulation, which leads to a more accurate permeability correction model for industrial applications than is currently available. PMID:27020130

  13. Impact of Adsorption on Gas Transport in Nanopores.

    PubMed

    Wu, Tianhao; Zhang, Dongxiao

    2016-01-01

    Given the complex nature of the interaction between gas and solid atoms, the development of nanoscale science and technology has engendered a need for further understanding of gas transport behavior through nanopores and more tractable models for large-scale simulations. In the present paper, we utilize molecular dynamic simulations to demonstrate the behavior of gas flow under the influence of adsorption in nano-channels consisting of illite and graphene, respectively. The results indicate that velocity oscillation exists along the cross-section of the nano-channel, and the total mass flow could be either enhanced or reduced depending on variations in adsorption under different conditions. The mechanisms can be explained by the extra average perturbation stress arising from density oscillation via the novel perturbation model for micro-scale simulation, and approximated via the novel dual-region model for macro-scale simulation, which leads to a more accurate permeability correction model for industrial applications than is currently available. PMID:27020130

  14. Synergies and Tradeoffs Among Environmental Impacts Under Conservation Planning of Shale Gas Surface Infrastructure.

    PubMed

    Milt, Austin W; Gagnolet, Tamara; Armsworth, Paul R

    2016-01-01

    Hydraulic fracturing and related ground water issues are growing features in public discourse. Few have given much attention to surface impacts from shale gas development, which result from building necessary surface infrastructure. One way to reduce future impacts from gas surface development without radically changing industry practice is by formulating simple, conservation-oriented planning guidelines. We explore how four such guidelines affect the locations of well pads, access roads, and gathering pipelines on state lands in Pennsylvania. Our four guidelines aim to (1) reduce impacts on water, reduce impacts from (2) gathering pipelines and (3) access roads, and (4) reduce impacts on forests. We assessed whether the use of such guidelines accompanies tradeoffs among impacts, and if any guidelines perform better than others at avoiding impacts. We find that impacts are mostly synergistic, such that avoiding one impact will result in avoiding others. However, we found that avoiding forest fragmentation may result in increased impacts on other environmental features. We also found that single simple planning guidelines can be effective in targeted situations, but no one guideline was universally optimal in avoiding all impacts. As such, we suggest that when multiple environmental features are important in an area, more comprehensive planning strategies and tools should be used. PMID:26275668

  15. Synergies and Tradeoffs Among Environmental Impacts Under Conservation Planning of Shale Gas Surface Infrastructure

    NASA Astrophysics Data System (ADS)

    Milt, Austin W.; Gagnolet, Tamara; Armsworth, Paul R.

    2016-01-01

    Hydraulic fracturing and related ground water issues are growing features in public discourse. Few have given much attention to surface impacts from shale gas development, which result from building necessary surface infrastructure. One way to reduce future impacts from gas surface development without radically changing industry practice is by formulating simple, conservation-oriented planning guidelines. We explore how four such guidelines affect the locations of well pads, access roads, and gathering pipelines on state lands in Pennsylvania. Our four guidelines aim to (1) reduce impacts on water, reduce impacts from (2) gathering pipelines and (3) access roads, and (4) reduce impacts on forests. We assessed whether the use of such guidelines accompanies tradeoffs among impacts, and if any guidelines perform better than others at avoiding impacts. We find that impacts are mostly synergistic, such that avoiding one impact will result in avoiding others. However, we found that avoiding forest fragmentation may result in increased impacts on other environmental features. We also found that single simple planning guidelines can be effective in targeted situations, but no one guideline was universally optimal in avoiding all impacts. As such, we suggest that when multiple environmental features are important in an area, more comprehensive planning strategies and tools should be used.

  16. Impacts of Sixteen Different Biochars on Soil Greenhouse Gas Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One potential abatement strategy to increasing atmospheric levels of carbon dioxide (CO2) is to sequester atmospheric CO2 captured through photosynthesis in biomass and pyrolysed into a more stable form of carbon called biochar. We evaluated the impacts of 16 different biochars from different pyroly...

  17. Impact of numerical integration on gas curtain simulations

    SciTech Connect

    Rider, W.; Kamm, J.

    2000-11-01

    In recent years, we have presented a less than glowing experimental comparison of hydrodynamic codes with the gas curtain experiment (e.g., Kamm et al. 1999a). Here, we discuss the manner in which the details of the hydrodynamic integration techniques may conspire to produce poor results. This also includes some progress in improving the results and agreement with experimental results. Because our comparison was conducted on the details of the experimental images (i.e., their detailed structural information), our results do not conflict with previously published results of good agreement with Richtmyer-Meshkov instabilities based on the integral scale of mixing. New experimental and analysis techniques are also discussed.

  18. Volatile organic compound emissions from unconventional natural gas production: Source signatures and air quality impacts

    NASA Astrophysics Data System (ADS)

    Swarthout, Robert F.

    Advances in horizontal drilling and hydraulic fracturing over the past two decades have allowed access to previously unrecoverable reservoirs of natural gas and led to an increase in natural gas production. Intensive unconventional natural gas extraction has led to concerns about impacts on air quality. Unconventional natural gas production has the potential to emit vast quantities of volatile organic compounds (VOCs) into the atmosphere. Many VOCs can be toxic, can produce ground-level ozone or secondary organic aerosols, and can impact climate. This dissertation presents the results of experiments designed to validate VOC measurement techniques, to quantify VOC emission rates from natural gas sources, to identify source signatures specific to natural gas emissions, and to quantify the impacts of these emissions on potential ozone formation and human health. Measurement campaigns were conducted in two natural gas production regions: the Denver-Julesburg Basin in northeast Colorado and the Marcellus Shale region surrounding Pittsburgh, Pennsylvania. An informal measurement intercomparison validated the canister sampling methodology used throughout this dissertation for the measurement of oxygenated VOCs. Mixing ratios of many VOCs measured during both campaigns were similar to or higher than those observed in polluted cities. Fluxes of natural gas-associated VOCs in Colorado ranged from 1.5-3 times industry estimates. Similar emission ratios relative to propane were observed for C2-C6 alkanes in both regions, and an isopentane:n-pentane ratio ≈1 was identified as a unique tracer for natural gas emissions. Source apportionment estimates indicated that natural gas emissions were responsible for the majority of C2-C8 alkanes observed in each region, but accounted for a small proportion of alkenes and aromatic compounds. Natural gas emissions in both regions accounted for approximately 20% of hydroxyl radical reactivity, which could hinder federal ozone standard

  19. Gas phase plasma impact on phenolic compounds in pomegranate juice.

    PubMed

    Herceg, Zoran; Kovačević, Danijela Bursać; Kljusurić, Jasenka Gajdoš; Jambrak, Anet Režek; Zorić, Zoran; Dragović-Uzelac, Verica

    2016-01-01

    The aim of the study was to evaluate the effect of gas phase plasma on phenolic compounds in pomegranate juice. The potential of near infrared reflectance spectroscopy combined with partial least squares for monitoring the stability of phenolic compounds during plasma treatment was explored, too. Experiments are designed to investigate the effect of plasma operating conditions (treatment time 3, 5, 7 min; sample volume 3, 4, 5 cm(3); gas flow 0.75, 1, 1.25 dm(3) min(-1)) on phenolic compounds and compared to pasteurized and untreated pomegranate juice. Pasteurization and plasma treatment resulted in total phenolic content increasing by 29.55% and 33.03%, respectively. Principal component analysis and sensitivity analysis outputted the optimal treatment design with plasma that could match the pasteurized sample concerning the phenolic stability (5 min/4 cm(3)/0.75 dm(3) min(-1)). Obtained results demonstrate the potential of near infrared reflectance spectroscopy that can be successfully used to evaluate the quality of pomegranate juice upon plasma treatment considering the phenolic compounds. PMID:26213024

  20. Impacts of Coal Seam Gas (Coal Bed Methane) and Coal Mining on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, D. A.

    2013-12-01

    Mining of coal bed methane deposits (termed ';coal seam gas' in Australia) is a rapidly growing source of natural gas in Australia. Indeed, expansion of the industry is occurring so quickly that in some cases, legislation is struggling to keep up with this expansion. Perhaps because of this, community concern about the impacts of coal seam gas development is very strong. Responding to these concerns, the Australian Government has recently established an Independent Expert Scientific Committee (IESC) to provide advice to the Commonwealth and state regulators on potential water-related impacts of coal seam gas and large coal mining developments. In order to provide the underlying science to the IESC, a program of ';bioregional assessments' has been implemented. One aim of these bioregional assessments is to improve our understanding of the connectivity between the impacts of coal seam gas extraction and groundwater aquifers, as well as their connection to surface water. A bioregional assessment can be defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion, with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are now being carried out across large portions of eastern Australia which are underlain by coal reserves. This presentation will provide an overview of the issues related to the impacts of coal seam gas and coal mining on water resources in Australia. The methodology of undertaking bioregional assessments will be described, and the application of this methodology to six priority bioregions in eastern Australia will be detailed. Preliminary results of the program of research to date will be assessed in light of the requirements of the IESC to provide independent advice to the Commonwealth and State governments. Finally, parallels between the expansion of the industry in Australia with that

  1. Impact of shale gas development on water resources: a case study in northern poland.

    PubMed

    Vandecasteele, Ine; Marí Rivero, Inés; Sala, Serenella; Baranzelli, Claudia; Barranco, Ricardo; Batelaan, Okke; Lavalle, Carlo

    2015-06-01

    Shale gas is currently being explored in Europe as an alternative energy source to conventional oil and gas. There is, however, increasing concern about the potential environmental impacts of shale gas extraction by hydraulic fracturing (fracking). In this study, we focussed on the potential impacts on regional water resources within the Baltic Basin in Poland, both in terms of quantity and quality. The future development of the shale play was modeled for the time period 2015-2030 using the LUISA modeling framework. We formulated two scenarios which took into account the large range in technology and resource requirements, as well as two additional scenarios based on the current legislation and the potential restrictions which could be put in place. According to these scenarios, between 0.03 and 0.86% of the total water withdrawals for all sectors could be attributed to shale gas exploitation within the study area. A screening-level assessment of the potential impact of the chemicals commonly used in fracking was carried out and showed that due to their wide range of physicochemical properties, these chemicals may pose additional pressure on freshwater ecosystems. The legislation put in place also influenced the resulting environmental impacts of shale gas extraction. Especially important are the protection of vulnerable ground and surface water resources and the promotion of more water-efficient technologies. PMID:25877457

  2. Impact of Shale Gas Development on Water Resources: A Case Study in Northern Poland

    NASA Astrophysics Data System (ADS)

    Vandecasteele, Ine; Marí Rivero, Inés; Sala, Serenella; Baranzelli, Claudia; Barranco, Ricardo; Batelaan, Okke; Lavalle, Carlo

    2015-06-01

    Shale gas is currently being explored in Europe as an alternative energy source to conventional oil and gas. There is, however, increasing concern about the potential environmental impacts of shale gas extraction by hydraulic fracturing (fracking). In this study, we focussed on the potential impacts on regional water resources within the Baltic Basin in Poland, both in terms of quantity and quality. The future development of the shale play was modeled for the time period 2015-2030 using the LUISA modeling framework. We formulated two scenarios which took into account the large range in technology and resource requirements, as well as two additional scenarios based on the current legislation and the potential restrictions which could be put in place. According to these scenarios, between 0.03 and 0.86 % of the total water withdrawals for all sectors could be attributed to shale gas exploitation within the study area. A screening-level assessment of the potential impact of the chemicals commonly used in fracking was carried out and showed that due to their wide range of physicochemical properties, these chemicals may pose additional pressure on freshwater ecosystems. The legislation put in place also influenced the resulting environmental impacts of shale gas extraction. Especially important are the protection of vulnerable ground and surface water resources and the promotion of more water-efficient technologies.

  3. Plasma jet's shielding gas impact on bacterial inactivation.

    PubMed

    Jablonowski, Helena; Hänsch, Mareike A Ch; Dünnbier, Mario; Wende, Kristian; Hammer, Malte U; Weltmann, Klaus-Dieter; Reuter, Stephan; Woedtke, Thomas von

    2015-01-01

    One of the most desired aims in plasma medicine is to inactivate prokaryotic cells and leave eukaryotic cells unharmed or even stimulate proliferation to promote wound healing. The method of choice is to precisely control the plasma component composition. Here the authors investigate the inactivation of bacteria (Escherichia coli) by a plasma jet treatment. The reactive species composition created by the plasma in liquids is tuned by the use of a shielding gas device to achieve a reactive nitrogen species dominated condition or a reactive oxygen species dominated condition. A strong correlation between composition of the reactive components and the inactivation of the bacteria is observed. The authors compare the results to earlier investigations on eukaryotic cells and show that it is possible to find a plasma composition where bacterial inactivation is strongest and adverse effects on eukaryotic cells are minimized. PMID:25832438

  4. Mapping Oil and Gas Development Potential in the US Intermountain West and Estimating Impacts to Species

    PubMed Central

    Copeland, Holly E.; Doherty, Kevin E.; Naugle, David E.; Pocewicz, Amy; Kiesecker, Joseph M.

    2009-01-01

    Background Many studies have quantified the indirect effect of hydrocarbon-based economies on climate change and biodiversity, concluding that a significant proportion of species will be threatened with extinction. However, few studies have measured the direct effect of new energy production infrastructure on species persistence. Methodology/Principal Findings We propose a systematic way to forecast patterns of future energy development and calculate impacts to species using spatially-explicit predictive modeling techniques to estimate oil and gas potential and create development build-out scenarios by seeding the landscape with oil and gas wells based on underlying potential. We illustrate our approach for the greater sage-grouse (Centrocercus urophasianus) in the western US and translate the build-out scenarios into estimated impacts on sage-grouse. We project that future oil and gas development will cause a 7–19 percent decline from 2007 sage-grouse lek population counts and impact 3.7 million ha of sagebrush shrublands and 1.1 million ha of grasslands in the study area. Conclusions/Significance Maps of where oil and gas development is anticipated in the US Intermountain West can be used by decision-makers intent on minimizing impacts to sage-grouse. This analysis also provides a general framework for using predictive models and build-out scenarios to anticipate impacts to species. These predictive models and build-out scenarios allow tradeoffs to be considered between species conservation and energy development prior to implementation. PMID:19826472

  5. Study of the impact of gas temperature and pressure on image quality of lithography objective lens

    NASA Astrophysics Data System (ADS)

    Zhou, Chao; Xing, Tingwen

    2013-08-01

    The aim of present work is to estimate the impact of gas refractive index shift on the image quality of projection lens caused by the change of environment condition. This work in the paper consists of two parts: a)when temperature rises or reduces, how gas refractive index changes and the wave front error comes up; b)when gas pressure changes. The model objective lens developed for simulation is a US patent lens whose NA <1 and wave front RMS < 5nm in all fields. This paper includes an illustration of the impact of gas refractive index shift on optical system data, wave front, and aberration. According to the analysis, wave front RMS of projection lens will increase about 10nm if the temperature changed by 0.1K or the gas pressure by 100 Pa. Comparing to origin wave front RMS of the patent lens, 5nm, the change caused by gas temperature and pressure can't be neglected. It proves the necessary of compensating or controlling the optical path change resulted from gas refractive index shift during the lithography projection lens work process.

  6. Impact of gravity on hydrate saturation in gas-rich environments

    NASA Astrophysics Data System (ADS)

    You, Kehua; DiCarlo, David; Flemings, Peter B.

    2016-02-01

    We extend a one-dimensional analytical solution by including buoyancy-driven flow to explore the impact of gravity on hydrate formation from gas injection into brine-saturated sediments within the hydrate stability zone. This solution includes the fully coupled gas and liquid phase flow and the associated advective transport in a homogeneous system. We obtain the saturations assuming Darcy flow under combined pressure and gravity gradients; capillary forces are neglected. At a high gas supply rate, the overpressure gradient (gradient of water pressure deviation from the hydrostatic pressure) dominates the gas flow, and the hydrate saturation is independent of the flow rate and flow direction. At a low gas supply rate, the buoyancy (the drive for gas flow induced by the density difference between gas and liquid) dominates the gas flow, and the hydrate saturation depends on the flow rate and flow direction. Hydrate saturation is highest for upward flow, and lowest for downward flow. Hydrate saturation decreases with flow rate for upward flow, and increases with flow rate for downward flow. In all cases, hydrate saturation is constant behind the hydrate solidification front. Gas saturation is homogeneous and close to the residual value for upward flow at a low rate; gas flows at the rate it is supplied. Gas saturation is much greater than the residual value, and decreases from the gas inlet to the hydrate solidification front for downward flow at a very low rate. The effect of gravity is usually negligible in laboratory experiments, yet is significant in natural hydrate systems.

  7. Environmental impacts of food trade via resource use and greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Dalin, Carole; Rodríguez-Iturbe, Ignacio

    2016-03-01

    Agriculture will need to significantly intensify in the next decades to continue providing essential nutritive food to a growing global population. However, it can have harmful environmental impacts, due to the use of natural and synthetic resources and the emission of greenhouse gases, which alter the water, carbon and nitrogen cycles, and threaten the fertility, health and biodiversity of landscapes. Because of the spatial heterogeneity of resource productivity, farming practices, climate, and land and water availability, the environmental impact of producing food is highly dependent on its origin. For this reason, food trade can either increase or reduce the overall environmental impacts of agriculture, depending on whether or not the impact is greater in the exporting region. Here, we review current scientific understanding of the environmental impacts of food trade, focusing on water and land use, pollution and greenhouse gas emissions. In the case of water, these impacts are mainly beneficial. However, in the cases of pollution and greenhouse gas emissions, this conclusion is not as clear. Overall, there is an urgent need for a more comprehensive, integrated approach to estimate the global impacts of food trade on the environment. Second, research is needed to improve the evaluation of some key aspects of the relative value of each resource depending on the local and regional biophysical and socio-economic context. Finally, to enhance the impact of such evaluations and their applicability in decision-making, scenario analyses and accounting of key issues like deforestation and groundwater exhaustion will be required.

  8. Physicochemical impacts associated with natural gas development on methanogenesis in deep sand aquifers.

    PubMed

    Katayama, Taiki; Yoshioka, Hideyoshi; Muramoto, Yoshiyuki; Usami, Jun; Fujiwara, Kazuhiro; Yoshida, Satoshi; Kamagata, Yoichi; Sakata, Susumu

    2015-02-01

    The Minami-Kanto gas field, where gases are dissolved in formation water, is a potential analogue for a marine gas hydrate area because both areas are characterized by the accumulation of microbial methane in marine turbidite sand layers interbedded with mud layers. This study examined the physicochemical impacts associated with natural gas production and well drilling on the methanogenic activity and composition in this gas field. Twenty-four gas-associated formation water samples were collected from confined sand aquifers through production wells. The stable isotopic compositions of methane in the gases indicated their origin to be biogenic via the carbonate reduction pathway. Consistent with this classification, methanogenic activity measurements using radiotracers, culturing experiments and molecular analysis of formation water samples indicated the predominance of hydrogenotrophic methanogenesis. The cultivation of water samples amended only with methanogenic substrates resulted in significant increases in microbial cells along with high-yield methane production, indicating the restricted availability of substrates in the aquifers. Hydrogenotrophic methanogenic activity increased with increasing natural gas production from the corresponding wells, suggesting that the flux of substrates from organic-rich mudstones to adjacent sand aquifers is enhanced by the decrease in fluid pressure in sand layers associated with natural gas/water production. The transient predominance of methylotrophic methanogens, observed for a few years after well drilling, also suggested the stimulation of the methanogens by the exposure of unutilized organic matter through well drilling. These results provide an insight into the physicochemical impacts on the methanogenic activity in biogenic gas deposits including marine gas hydrates. PMID:25105906

  9. Physicochemical impacts associated with natural gas development on methanogenesis in deep sand aquifers

    PubMed Central

    Katayama, Taiki; Yoshioka, Hideyoshi; Muramoto, Yoshiyuki; Usami, Jun; Fujiwara, Kazuhiro; Yoshida, Satoshi; Kamagata, Yoichi; Sakata, Susumu

    2015-01-01

    The Minami-Kanto gas field, where gases are dissolved in formation water, is a potential analogue for a marine gas hydrate area because both areas are characterized by the accumulation of microbial methane in marine turbidite sand layers interbedded with mud layers. This study examined the physicochemical impacts associated with natural gas production and well drilling on the methanogenic activity and composition in this gas field. Twenty-four gas-associated formation water samples were collected from confined sand aquifers through production wells. The stable isotopic compositions of methane in the gases indicated their origin to be biogenic via the carbonate reduction pathway. Consistent with this classification, methanogenic activity measurements using radiotracers, culturing experiments and molecular analysis of formation water samples indicated the predominance of hydrogenotrophic methanogenesis. The cultivation of water samples amended only with methanogenic substrates resulted in significant increases in microbial cells along with high-yield methane production, indicating the restricted availability of substrates in the aquifers. Hydrogenotrophic methanogenic activity increased with increasing natural gas production from the corresponding wells, suggesting that the flux of substrates from organic-rich mudstones to adjacent sand aquifers is enhanced by the decrease in fluid pressure in sand layers associated with natural gas/water production. The transient predominance of methylotrophic methanogens, observed for a few years after well drilling, also suggested the stimulation of the methanogens by the exposure of unutilized organic matter through well drilling. These results provide an insight into the physicochemical impacts on the methanogenic activity in biogenic gas deposits including marine gas hydrates. PMID:25105906

  10. 76 FR 22734 - South Carolina Electric and Gas; Notice of Availability of the Final Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION South Carolina Electric and Gas; Notice of Availability of the Final Environmental Impact Statement for Virgil C. Summer Nuclear Station, Units 2 and 3, Combined Licenses Application Review Notice is hereby given that the U.S. Nuclear...

  11. IMPACT OF NOX SELECTIVE CATALYTIC REDUCTION PROCESSES ON FLUE GAS CLEANING SYSTEMS

    EPA Science Inventory

    The report gives results of a study of the impact of the ammonia leaving a nitrogen oxide (NOx) selective catalytic reduction (SCR) process on downstream flue gas cleaning processes. (NOx emissions from electric utility boilers may be reduced 80-90% by the application of pollutio...

  12. 75 FR 45109 - Kern River Gas Transmission Company; Notice of Availability of the Final Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Kern River Gas Transmission Company; Notice of Availability of the Final Environmental Impact Statement for the Proposed APEX Expansion Project July 23, 2010. The staff of the Federal Energy Regulatory Commission...

  13. Corn stover removal impacts on soil greenhouse gas emissions in irrigated continuous corn systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harvesting corn stover for livestock feed or for cellulosic biofuel production may impact the greenhouse gas (GHG) mitigation potential of high-yield irrigated corn. Soil emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were measured over the 2011 growing season at two irri...

  14. EVALUATION OF VAPOR EQUILIBRATION AND IMPACT OF PURGE VOLUME ON SOIL-GAS SAMPLING RESULTS

    EPA Science Inventory

    Sequential sampling was utilized at the Raymark Superfund site to evaluate attainment of vapor equilibration and the impact of purge volume on soil-gas sample results. A simple mass-balance equation indicates that removal of three to five internal volumes of a sample system shou...

  15. Recent developments in environmental regulation impacting oil and gas production and refining

    SciTech Connect

    Pierce, D.E.

    1995-12-31

    This paper presents an overview of the recent major legal and regulatory developments impacting oil and gas exploration, production, and refining activities. The focus is upon the federal laws governing air, water, and land pollution for the period 1994 to the present.

  16. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2015-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However as coal seam gas deposits generally occur at shallower depths than shale gas the potential impacts of extraction and hydraulic fracturing on surface and groundwater resources may be of even greater concern for coal seam gas than for shale gas. In Australia an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice the Australian Government Department of the Environment has implemented a three-year programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the program and results to date can be found at http://www.bioregionalassessments.gov.au. In this presentation the methodology for undertaking bioregional assessments will be described and the application of this methodology to six priority bioregions in eastern Australia

  17. The Use of Health Impact Assessment for a Community Undergoing Natural Gas Development

    PubMed Central

    McKenzie, Lisa; Stinson, Kaylan E.; Scott, Kenneth; Newman, Lee S.; Adgate, John

    2013-01-01

    The development of natural gas wells is rapidly increasing, yet little is known about associated exposures and potential public health consequences. We used health impact assessment (HIA) to provide decision-makers with information to promote public health at a time of rapid decision making for natural gas development. We have reported that natural gas development may expose local residents to air and water contamination, industrial noise and traffic, and community changes. We have provided more than 90 recommendations for preventing or decreasing health impacts associated with these exposures. We also have reflected on the lessons learned from conducting an HIA in a politically charged environment. Finally, we have demonstrated that despite the challenges, HIA can successfully enhance public health policymaking. PMID:23597363

  18. Evaluating greenhouse gas impacts of organic waste management options using life cycle assessment.

    PubMed

    Kong, Dung; Shan, Jilei; Iacoboni, Mario; Maguin, Stephen R

    2012-08-01

    Efforts to divert organics away from landfills are viewed by many as an important measure to significantly reduce the climate change impacts of municipal solid waste management. However, the actual greenhouse gas (GHG) impacts of organics diversion from landfills have yet to be thoroughly evaluated and whether such a diversion provides significant environmental benefits in terms of GHG impacts must be answered. This study, using California-specific information, aimed to analyse the GHG impacts of organics diversion through a life-cycle assessment (LCA). This LCA considered all aspects of organics management including transportation, materials handling, GHG emissions, landfill gas capture/utilization, energy impacts, and carbon sequestration. The LCA study evaluated overall GHG impacts of landfilling, and alternative management options such as composting and anaerobic digestion for diverted organic waste. The LCA analysis resulted in net GHG reductions of 0.093, 0.048, 0.065 and 0.073 tonnes carbon equivalent per tonne organic waste for landfilling, windrow composting, aerated static pile composting, and anaerobic digestion, respectively. This study confirms that all three options for organics management result in net reductions of GHG emissions, but it also shows that organics landfilling, when well-managed, generates greater GHG reductions. The LCA provides scientific insight with regards to the environmental impacts of organics management options, which should be considered in decision and policy-making. The study also highlights the importance of how site and case-specific conditions influence project outcomes when considering organic waste management options. PMID:22588112

  19. 78 FR 47408 - Notice of Intent to Prepare an Environmental Impact Statement for Oil and Gas Leasing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ... Bureau of Land Management Notice of Intent to Prepare an Environmental Impact Statement for Oil and Gas...) amendment to evaluate oil and gas leasing and development on public lands and Federal mineral estate in the... EIS. ADDRESSES: You may submit comments related to the Oil and Gas Leasing and Development EIS by...

  20. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2016-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. Surface water and groundwater modelling is now complete for two regions where coal seam gas development may proceed, namely the Clarence-Moreton and Gloucester regions in eastern New South Wales. This presentation will discuss how the results of these

  1. Wintertime Air Quality Impacts from Oil and Natural Gas Drilling Operations in the Bakken Formation Region

    NASA Astrophysics Data System (ADS)

    Evanoski-Cole, Ashley; Sive, Barkley; Zhou, Yong; Prenni, Anthony; Schurman, Misha; Day, Derek; Sullivan, Amy; Li, Yi; Hand, Jenny; Gebhart, Kristi; Schichtel, Bret; Collett, Jeffrey

    2016-04-01

    Oil and natural gas extraction has dramatically increased in the last decade in the United States due to the increased use of unconventional drilling techniques which include horizontal drilling and hydraulic fracturing. The impact of these drilling activities on local and regional air quality in oil and gas basins across the country are still relatively unknown, especially in recently developed basins such as the Bakken shale formation. This study is the first to conduct a comprehensive characterization of the regional air quality in the Bakken region. The Bakken shale formation, part of the Williston basin, is located in North Dakota and Montana in the United States and Saskatchewan and Manitoba in Canada. Oil and gas drilling operations can impact air quality in a variety of ways, including the generation of atmospheric particulate matter (PM), hazardous air pollutants, ozone, and greenhouse gas emissions. During the winter especially, PM formation can be enhanced and meteorological conditions can favor increased concentrations of PM and other pollutants. In this study, ground-based measurements throughout the Bakken region in North Dakota and Montana were collected over two consecutive winters to gain regional trends of air quality impacts from the oil and gas drilling activities. Additionally, one field site had a comprehensive suite of instrumentation operating at high time resolution to gain detailed characterization of the atmospheric composition. Measurements included organic carbon and black carbon concentrations in PM, the characterization of inorganic PM, inorganic gases, volatile organic compounds (VOCs), precipitation and meteorology. These elevated PM episodes were further investigated using the local meteorological conditions and regional transport patterns. Episodes of elevated concentrations of nitrogen oxides and sulfur dioxide were also detected. The VOC concentrations were analyzed and specific VOCs that are known oil and gas tracers were used

  2. Study of Damage of Gas-filled Spherical Pressure Vassel Subjected to Hypervelocity Impact by Space Debris with Different Velocity

    NASA Astrophysics Data System (ADS)

    Cai, Yuan; Pang, Baojun; Jia, Bin

    2013-08-01

    As an important component of spacecraft, if a gas-filled pressure vessel is impacted by space debris, it might occur even overall bursting. Spherical aluminum projectiles are used to simulate space debris impacting gas-filled spherical pressure vessel with hypervelocity. Projectiles impact places with the same thickness in different tests. By analyzing the maximum gas pressure of the spherical vessel, the inflation pressure is determined: 1.075MPa. By numerical simulation, the critical impact velocity to perforate the front wall is determined: 2.02mm ~ 2.31mm. As the projectile velocity increases, the damage patterns of the back wall are of different bulged outwards patterns.

  3. Incorporating the effect of gas in modelling the impact of CBM extraction on regional groundwater systems

    NASA Astrophysics Data System (ADS)

    Herckenrath, Daan; Doherty, John; Panday, Sorab

    2015-04-01

    Production of Coalbed Methane (CBM) requires extraction of large quantities of groundwater. To date, standard groundwater flow simulators have mostly been used to assess the impact of this extraction on regional groundwater systems. Recent research has demonstrated that predictions of regional impact assessment made by such models may be seriously compromised unless account is taken of the presence of a gas phase near extraction wells. At the same time, CBM impact assessment must accommodate the traditional requirements of regional groundwater modelling. These include representation of surficial groundwater processes and up-scaled rock properties as well as the need for calibration and predictive uncertainty quantification. The study documented herein (1) quantifies errors in regional drawdown predictions incurred through neglect of the presence of a gas phase near CBM extraction centres, and (2) evaluates the extent to which these errors can be mitigated by simulating near-well desaturation using a modified Richards equation formulation within a standard groundwater flow simulator. Two synthetic examples are provided to quantify the impact of the gas phase and verify the proposed modelling approach (implemented in MODFLOW-USG) against rigorous multiphase flow simulations (undertaken using ECLIPSE)

  4. Mucosal deformation from an impinging transonic gas jet and the ballistic impact of microparticles

    NASA Astrophysics Data System (ADS)

    Hardy, M. P.; Kendall, M. A. F.

    2005-10-01

    By means of a transonic gas jet, gene guns ballistically deliver microparticle formulations of drugs and vaccines to the outer layers of the skin or mucosal tissue to induce unique physiological responses for the treatment of a range of conditions. Reported high-speed imaging experiments show that the mucosa deforms significantly while subjected to an impinging gas jet from a biolistic device. In this paper, the effect of this tissue surface deformation on microparticle impact conditions is simulated with computational fluid dynamics (CFD) calculations. The microparticles are idealized as spheres of diameters 26.1, 39 and 99 µm and a density of 1050 kg m-3. Deforming surface calculations of particle impact conditions are compared directly with an immobile surface case. The relative velocity and obliquity of the deforming surface decrease the normal component of particle impact velocity by up to 30% at the outer edge of the impinging gas jet. This is qualitatively consistent with reported particle penetration profiles in the tissue. It is recommended that these effects be considered in biolistic studies requiring quantified particle impact conditions.

  5. Ice Target and Gas Target Experiments in the IMPACT Dust Accelerator

    NASA Astrophysics Data System (ADS)

    Munsat, T. L.; Collette, A.; Dee, R.; Gruen, E.; Horanyi, M.; James, D.; Janches, D.; Kempf, S.; Plane, J. M. C.; Shu, A. J.; Simolka, J.; Sternovsky, Z.; Thomas, E.

    2014-12-01

    The dust accelerator facility at the SSERVI Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) is presently implementing two major target upgrades: a cryogenic ice target and a high-pressure gas target. The ice target consists of a LN2 cryogenic system connected to both a water-ice deposition system as well as a movable freezer/holder for a pre-mixed liquid cartridge. Planned experiments include the bombardment of a variety of frozen targets and simulated ice/regolith mixtures, and the assessment of all impact products (solid ejecta, gas, plasma) as well as spectroscopy of both the impact-produced light flashes and the reflected spectra (UV, visible, IR). Such measurements are highly relevant to both physical and chemical surface modification of airless bodies due to micrometeoroid impacts. The gas target consists of a differentially pumped chamber kept at moderate background pressures, such that high-velocity (~10 km/s) micrometeoroids are completely ablated within 10's of cm (i.e. within the measurement chamber). The chamber is configured with segmented electrodes to perform a spatially-resolved measurement of charge production during ablation, and localized light-collection optics enable an assessment of the light production (luminous efficiency). Such studies are critical to the understanding of past and future ground-based measurements of meteor ablation in Earth's atmosphere, which in turn can potentially provide the best estimates of the interplanetary dust particle flux.

  6. Life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well.

    PubMed

    Jiang, Mohan; Hendrickson, Chris T; VanBriesen, Jeanne M

    2014-01-01

    This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input-output life cycle assessment (EIO-LCA) method. Life cycle direct and indirect water quality pollution impacts were assessed and compared using the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Wastewater treatment cost was proposed as an additional indicator for water quality pollution impacts from shale gas well wastewater. Four water management scenarios for Marcellus shale well wastewater were assessed: current conditions in Pennsylvania; complete discharge; direct reuse and desalination; and complete desalination. The results show that under the current conditions, an average Marcellus shale gas well consumes 20,000 m(3) (with a range from 6700 to 33,000 m(3)) of freshwater per well over its life cycle excluding final gas utilization, with 65% direct water consumption at the well site and 35% indirect water consumption across the supply chain production. If all flowback and produced water is released into the environment without treatment, direct wastewater from a Marcellus shale gas well is estimated to have 300-3000 kg N-eq eutrophication potential, 900-23,000 kg 2,4D-eq freshwater ecotoxicity potential, 0-370 kg benzene-eq carcinogenic potential, and 2800-71,000 MT toluene-eq noncarcinogenic potential. The potential toxicity of the chemicals in the wastewater from the well site exceeds those associated with supply chain production, except for carcinogenic effects. If all the Marcellus shale well wastewater is

  7. Life Cycle Water Consumption and Wastewater Generation Impacts of a Marcellus Shale Gas Well

    PubMed Central

    2013-01-01

    This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input–output life cycle assessment (EIO-LCA) method. Life cycle direct and indirect water quality pollution impacts were assessed and compared using the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Wastewater treatment cost was proposed as an additional indicator for water quality pollution impacts from shale gas well wastewater. Four water management scenarios for Marcellus shale well wastewater were assessed: current conditions in Pennsylvania; complete discharge; direct reuse and desalination; and complete desalination. The results show that under the current conditions, an average Marcellus shale gas well consumes 20 000 m3 (with a range from 6700 to 33 000 m3) of freshwater per well over its life cycle excluding final gas utilization, with 65% direct water consumption at the well site and 35% indirect water consumption across the supply chain production. If all flowback and produced water is released into the environment without treatment, direct wastewater from a Marcellus shale gas well is estimated to have 300–3000 kg N-eq eutrophication potential, 900–23 000 kg 2,4D-eq freshwater ecotoxicity potential, 0–370 kg benzene-eq carcinogenic potential, and 2800–71 000 MT toluene-eq noncarcinogenic potential. The potential toxicity of the chemicals in the wastewater from the well site exceeds those associated with supply chain production, except for carcinogenic effects. If all the Marcellus shale well

  8. The economic impact of shale gas development on state and local economies: benefits, costs, and uncertainties.

    PubMed

    Barth, Jannette M

    2013-01-01

    It is often assumed that natural gas exploration and development in the Marcellus Shale will bring great economic prosperity to state and local economies. Policymakers need accurate economic information on which to base decisions regarding permitting and regulation of shale gas extraction. This paper provides a summary review of research findings on the economic impacts of extractive industries, with an emphasis on peer-reviewed studies. The conclusions from the studies are varied and imply that further research, on a case-by-case basis, is necessary before definitive conclusions can be made regarding both short- and long-term implications for state and local economies. PMID:23552649

  9. Quantifying habitat impacts of natural gas infrastructure to facilitate biodiversity offsetting

    PubMed Central

    Jones, Isabel L; Bull, Joseph W; Milner-Gulland, Eleanor J; Esipov, Alexander V; Suttle, Kenwyn B

    2014-01-01

    Habitat degradation through anthropogenic development is a key driver of biodiversity loss. One way to compensate losses is “biodiversity offsetting” (wherein biodiversity impacted is “replaced” through restoration elsewhere). A challenge in implementing offsets, which has received scant attention in the literature, is the accurate determination of residual biodiversity losses. We explore this challenge for offsetting gas extraction in the Ustyurt Plateau, Uzbekistan. Our goal was to determine the landscape extent of habitat impacts, particularly how the footprint of “linear” infrastructure (i.e. roads, pipelines), often disregarded in compensation calculations, compares with “hub” infrastructure (i.e. extraction facilities). We measured vegetation cover and plant species richness using the line-intercept method, along transects running from infrastructure/control sites outward for 500 m, accounting for wind direction to identify dust deposition impacts. Findings from 24 transects were extrapolated to the broader plateau by mapping total landscape infrastructure network using GPS data and satellite imagery. Vegetation cover and species richness were significantly lower at development sites than controls. These differences disappeared within 25 m of the edge of the area physically occupied by infrastructure. The current habitat footprint of gas infrastructure is 220 ± 19 km2 across the Ustyurt (total ∼ 100,000 km2), 37 ± 6% of which is linear infrastructure. Vegetation impacts diminish rapidly with increasing distance from infrastructure, and localized dust deposition does not conspicuously extend the disturbance footprint. Habitat losses from gas extraction infrastructure cover 0.2% of the study area, but this reflects directly eliminated vegetation only. Impacts upon fauna pose a more difficult determination, as these require accounting for behavioral and demographic responses to disturbance by elusive mammals, including threatened species

  10. Statistical evaluation of the impact of shale gas activities on ozone pollution in North Texas.

    PubMed

    Ahmadi, Mahdi; John, Kuruvilla

    2015-12-01

    Over the past decade, substantial growth in shale gas exploration and production across the US has changed the country's energy outlook. Beyond its economic benefits, the negative impacts of shale gas development on air and water are less well known. In this study the relationship between shale gas activities and ground-level ozone pollution was statistically evaluated. The Dallas-Fort Worth (DFW) area in north-central Texas was selected as the study region. The Barnett Shale, which is one the most productive and fastest growing shale gas fields in the US, is located in the western half of DFW. Hourly meteorological and ozone data were acquired for fourteen years from monitoring stations established and operated by the Texas Commission on Environmental Quality (TCEQ). The area was divided into two regions, the shale gas region (SGR) and the non-shale gas (NSGR) region, according to the number of gas wells in close proximity to each monitoring site. The study period was also divided into 2000-2006 and 2007-2013 because the western half of DFW has experienced significant growth in shale gas activities since 2007. An evaluation of the raw ozone data showed that, while the overall trend in the ozone concentration was down over the entire region, the monitoring sites in the NSGR showed an additional reduction of 4% in the annual number of ozone exceedance days than those in the SGR. Directional analysis of ozone showed that the winds blowing from areas with high shale gas activities contributed to higher ozone downwind. KZ-filtering method and linear regression techniques were used to remove the effects of meteorological variations on ozone and to construct long-term and short-term meteorologically adjusted (M.A.) ozone time series. The mean value of all M.A. ozone components was 8% higher in the sites located within the SGR than in the NSGR. These findings may be useful for understanding the overall impact of shale gas activities on the local and regional ozone

  11. Surface and Column Aerosol Impacts of the United States' Natural Gas Transition

    NASA Astrophysics Data System (ADS)

    Burney, J. A.

    2015-12-01

    This paper quantifies the air pollution and climate impacts of the natural gas transition over the past decade in the United States. We integrate satellite and ground measurements with chemical transport modeling to understand the impact of of the large-scale shift from coal to natural gas on the quantity and chemical composition of column aerosol and surface particulate matter. We leverage the natural experiment of individual units that changed technologies (a sharp discontinuity) as well as state-level changes from old plants being taken offline and new ones being brought online (a soft discontinuity) and connect technology changes to emissions changes to detected aerosol / particulate matter changes. We use this methodology to estimate the size of the 'sulfate' mask due to coal consumption in the United States and understand more fully the climate implications of energy technology changes.

  12. Laboratory Measurements of Micrometeoroid Impacts into Solid Ice and Gas Ablation Targets

    NASA Astrophysics Data System (ADS)

    Munsat, T. L.; Britt, D. T.; Dee, R.; Gudipati, M. S.; Horanyi, M.; James, D.; Janches, D.; Kempf, S.; Nelson, A. O.; Plane, J. M. C.; Shu, A. J.; Sternovsky, Z.; Thomas, E.; Ulibarri, Z.

    2015-12-01

    The dust accelerator facility at the SSERVI Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) has recently implemented two major target upgrades: a cryogenic ice target and a high-pressure gas target. Each target can be exposed to micron and submicron particles accelerated to speeds up to 100 km/s. The ice target consists of a LN2 cryogenic system connected to both a water-ice deposition system and a movable freezer/holder for a pre-mixed liquid cartridge. Impact products and chemistry are assessed with an integrated time-of-flight mass spectrometer. Such a system enables a program of research into the evolution of ice under micrometeoroid bombardment and the synthesis of complex organic molecules through micrometeoroid impacts. We present the early results from studies of hypervelocity iron particle impacts into frozen mixtures of H2O, NH3, and olivine grains which contain nanophase Fe, a possible catalyst for organic chemical reactions, under conditions of low-pressure background CO or CO2 gas. The gas target consists of a differentially pumped chamber kept at pressures up to 0.5 Torr, such that high-velocity (~10-60 km/s) micrometeoroids are completely ablated within the 40 cm long measurement region. The chamber is configured with segmented electrodes to perform temporally- and spatially-resolved measurements of charge production during ablation, and localized light-collection optics enable an assessment of the light production. We present the latest results of experiments to determine the ionization efficiency of Fe particles ablating in N2, air, CO2, and He gas, and modifications to standard ablation models made possible from these experimental results. Such studies are critical for the interpretation of remote sensing measurements, including radar and lidar, which in turn make possible the assessment of the interplanetary dust particle flux.

  13. Modeled Oil and Gas Atmospheric Impacts in National Parks and Wilderness Areas in the Western US

    NASA Astrophysics Data System (ADS)

    Thompson, T. M.; Barna, M. G.; Schichtel, B. A.; Vimont, J.; Moore, C. T.

    2014-12-01

    Oil and gas production in the Western United States has increased considerably over the past 10 years. While many of the still limited oil and gas impact assessments have focused on potential human health impacts, the typically remote locations of production in the Intermountain West suggests that the impacts of oil and gas production on national parks and wilderness areas (class 1&2 areas) could also be important. To evaluate this, we utilize the Comprehensive Air quality Model with Extensions (CAMx) with two year-long modeling episodes representing 2008 and 2011, meteorology and emissions. The model inputs for the 2008 and 2011 episodes were generated as part of the West-wide Jump-start Air Quality Modeling Study (WestJumpAQMS) and Three State Air Quality Study (3SAQS) respectively. Both studies included a detailed assessment of oil and gas (O&G) emissions in Western States for the respective years. Each year-long modeling episode was run both with and without emissions from O&G production. The difference between these two runs provides an estimate of the contribution of the O&G production to air quality. These data were used to assess the contribution of O&G to the 8 hour average ozone concentrations, daily and annual fine particulate concentrations, annual nitrogen deposition totals and visibility in the modeling domain. We present the results for the class 1&2 areas in the Western US. We also present temporal trends of O&G impacts, differentiating between trends in urban and rural areas.

  14. Spatial Air Quality Impacts of Increased Natural Gas Development and Use in Texas

    NASA Astrophysics Data System (ADS)

    Allen, D.; Pacsi, A. P.

    2013-12-01

    Compared to coal-fired power plants on a per MWh basis, natural-gas electricity generators in the grid of the Electricity Reliability Council of Texas (ERCOT) emit substantially less nitrogen oxides (NOx) and sulfur dioxide (SO2), which are precursors for the formation of ozone (O3) and fine particulate matter (PM2.5). In addition, several life-cycle assessments have concluded that the development and use of shale gas resources will likely lead to air quality benefits, despite emissions associated with natural gas production, due to changes in fuel utilization in the electricity generation sector. The formation of ozone and PM2.5 is non-linear, however, and depends on spatial and temporal patterns associated with the precursor emissions. This study used Texas as a case-study for the changes in regional ozone and PM2.5 concentrations associated with natural gas production and use in electricity generation in the state. Texas makes a compelling case study since it was among the first states with large-scale shale gas production with horizontal drilling and hydraulic fracturing technologies, since it has a self-contained electric grid (ERCOT), and since it includes several regions which do not currently meet Federal standards for ozone. This study utilized an optimal power flow model for electricity generation in ERCOT, coupled with a regional photochemical model to estimate the ozone and PM2.5 impacts of changes to natural gas production and use in the state. The utilization of natural gas is highly dependent on the relative price of natural gas compared to coal. Thus, the amount of natural gas consumed in power generation in ERCOT was estimated for a range of prices from 1.89-7.74, which have occurred in Texas since 2006. Sensitivity scenarios in which natural gas production emissions in the Barnett Shale were raised or lowered depending on demand for the fuel in the electricity generation sector were also examined. Overall results indicate that regional ozone and

  15. Simultaneous screening for and determination of 128 date-rape drugs in urine by gas chromatography-electron ionization-mass spectrometry.

    PubMed

    Adamowicz, Piotr; Kała, Maria

    2010-05-20

    Date-rape drugs (DRDs) are used for the purpose of "drugging" unsuspected victims and raping or robbing them while under the influence of the drug. The wide variety of substances used for criminal purposes, their low concentrations in body fluids and, often, a long time delay between the event and clinical examination make comprehensive screening analysis of biological materials collected from crime victims for the presence of these drugs very difficult. Detection of a drug used to facilitate sexual assault in biological fluids can be very important evidence of a committed crime. The purpose of this study was to develop a simple GC-EI-MS screening procedure for date-rape drugs in urine. Target analytes were isolated by solid-phase extraction. 2-mL urine samples were extracted and then derivatized by using BSTFA+1%TMCS reagent. Detection of all compounds was based on full-scan mass spectra and for each compound one ion was chosen for further quantification. The method allowed the simultaneous screening, detection and quantification of 128 compounds from different groups (number of compounds): opioids (20), amphetamines (11), GHB and related products (3), hallucinogens (9), benzodiazepines (18), antihistamines (9), antidepressants (14), selective serotonin-reuptake inhibitors (4), antipsychotics (7), barbiturates (7), other sedatives (5), muscle relaxants (2) and other drugs (19). The procedure can easily be expanded to encompass more substances. The developed method appeared to be suitable for screening for the target DRDs. The procedure was successfully applied to the analysis of authentic urine samples collected from victims of rapes and other crimes in routine casework. PMID:20207513

  16. Copper clean-up procedure for ultrasonic extraction and analysis of pyrethroid and phenylpyrazole pesticides in sediments by gas chromatography-electron capture detection.

    PubMed

    Wu, Jun; Lin, Youjian; Lu, Jian; Wilson, Chris

    2011-08-15

    A rapid ultrasonic extraction method coupled with a heated-copper clean-up procedure for removing interfering constituents was developed for analyzing pyrethroid and phenylpyrazole pesticides in sediments. Incubation of the 60 mL extract with 12 g copper granules at 60 °C for 2h was determined to be the optimal conditions for removing the interfering constituents. Eleven pyrethroid and phenylpyrazole pesticides were spiked into sediment samples to determine the effectiveness of the ultrasonic extraction method. The average recoveries of pyrethroids and phenylpyrazoles in sediment at 4 °C storage on day 0, 1, 7, 14, and 21 ranged from 98.6 to 120.0%, 79.2 to 116.0%, 85.0 to 119.7%, 93.6 to 118.7%, and 92.1 to 118.2%, respectively, with all percent relative standard deviations less than 10% (most <6%). This illustrated the stability of pyrethroids and phenylpyrazoles in sediment during sediment aging at 4 °C. Recoveries of the pesticides ranged from 98.6% to 120.0% for lowest fortification level (2-16 μg kg⁻¹), from 97.8% to 117.9% for middle fortification level (10-80 μg kg⁻¹), and from 94.3% to 118.1% for highest fortification level (20-160 μg kg⁻¹). Relative standard deviations of pesticide recoveries were usually less than 7%. Method detection limits of target pesticides ranged from 0.22 μg kg⁻¹ to 3.72 μg kg⁻¹. Furthermore, field sediment samples collected from four residential lakes during a three-month monitoring period were analyzed to evaluate the effectiveness of this method. Bifenthrin was detected in all of sediment samples (highest concentration 260.33±41.71 μg kg⁻¹, lowest concentration 5.68±0.38 μg kg⁻¹, and fipronil sulfone was detected at least once in sediment samples collected from three sites with concentrations ranging from 1.73±0.53 to 7.53±0.01 μg kg⁻¹. PMID:21684581

  17. EMBRYO IMPACTS AND GAS GIANT MERGERS. I. DICHOTOMY OF JUPITER AND SATURN's CORE MASS

    SciTech Connect

    Li Shulin; Agnor, C.B.; Lin, D. N. C.

    2010-09-10

    Interior to the gaseous envelopes of Saturn, Uranus, and Neptune, there are high-density cores with masses larger than 10 Earth masses. According to the conventional sequential accretion hypothesis, such massive cores are needed for the onset of efficient accretion of their gaseous envelopes. However, Jupiter's gaseous envelope is more massive and its core may be less massive than those of Saturn. In order to account for this structural diversity and the super-solar metallicity in the envelope of Jupiter and Saturn, we investigate the possibility that they may have either merged with other gas giants or consumed several Earth-mass protoplanetary embryos during or after the rapid accretion of their envelope. In general, impinging sub-Earth-mass planetesimals disintegrate in gas giants' envelopes, deposit heavy elements well outside the cores, and locally suppress the convection. Consequently, their fragments sediment to promote the growth of cores. Through a series of numerical simulations, we show that it is possible for colliding super-Earth-mass embryos to reach the cores of gas giants. Direct parabolic collisions also lead to the coalescence of gas giants and merging of their cores. In these cases, the energy released from the impact leads to vigorous convective motion throughout the envelope and the erosion of the cores. This dichotomy contributes to the observed dispersion in the internal structure and atmospheric composition between Jupiter and Saturn and other gas giant planets and elsewhere.

  18. Global cropland and greenhouse gas impacts of UK food supply are increasingly located overseas.

    PubMed

    de Ruiter, Henri; Macdiarmid, Jennie I; Matthews, Robin B; Kastner, Thomas; Smith, Pete

    2016-01-01

    Producing sufficient, healthy food for a growing world population amid a changing climate is a major challenge for the twenty-first century. Agricultural trade could help alleviate this challenge by using comparative productivity advantages between countries. However, agricultural trade has implications for national food security and could displace environmental impacts from developed to developing countries. This study illustrates the global effects resulting from the agricultural trade of a single country, by analysing the global cropland and greenhouse gas impacts of the UK's food and feed supply. The global cropland footprint associated with the UK food and feed supply increased by 2022 kha (+23%) from 1986 to 2009. Greenhouse gas emissions (GHGE) associated with fertilizer and manure application, and rice cultivation remained relatively constant at 7.9 Mt CO2e between 1987 and 2008. Including GHGE from land-use change, however, leads to an increase from 19.1 in 1987 to 21.9 Mt CO2e in 2008. The UK is currently importing over 50% of its food and feed, whereas 70% and 64% of the associated cropland and GHGE impacts, respectively, are located abroad. These results imply that the UK is increasingly reliant on external resources and that the environmental impact of its food supply is increasingly displaced overseas. PMID:26740576

  19. Impacts of natural gas mining on regional methane levels in Pennsylvania

    NASA Astrophysics Data System (ADS)

    Lembeck-Edens, A. M.; Fuentes, J. D.; Martins, D. K.; Grannas, A. M.

    2013-12-01

    Increased natural gas exploration has been hypothesized to be a strong source of atmospheric methane, leading to enhanced regional methane levels. Fugitive methane emissions can result from leaky natural gas wells and pipelines. Pennsylvania is experiencing rapid natural gas well development and operation. In the Pennsylvania Marcellus Shale region, the density of natural gas wells is increasing. Therefore, a field study took place during 8 June to 6 August 2013 to investigate the magnitude of fugitive methane emissions near well sites and along established pipelines, as well as the spatial distribution of methane throughout Pennsylvania. The necessary instruments were mounted on a mobile platform (six-passenger van) to make transects running from southwestern to northeastern Pennsylvania where the highest density of wells is already established. Methane and carbon dioxide mixing ratios and their respective 13C isotopes were detected using a cavity ring-down spectrometer while the van was moving along pipelines or near natural gas well sites. Air sampling was done in areas away from natural well sites to establish the baseline of methane levels in the rural atmosphere. Also, air sampling took place around barns to distinguish the contribution of cattle to the atmospheric loading of methane. In the rural atmosphere, away from natural gas wells, methane levels remained around (baseline) 1.75 parts per millions (ppm). Methane levels in areas impacted by natural gas wells were higher than the baseline. Along pipelines, methane levels ranged from baseline levels of 1.75 ppm to 5.00 ppm. Near wells, plumes of methane-enriched air reached as high as 15.30 ppm. Although leaks from wells have been noted in previous studies, this investigation suggested that wells intermittently leaked methane. The main conclusion from the present study is that fugitive emissions from natural gas wells and pipelines contribute to enhancing the regional methane levels during daytime

  20. Evaluating the impact of gas extraction infrastructure on the occupancy of sagebrush-obligate songbirds.

    PubMed

    Mutter, Max; Pavlacky, David C; Van Lanen, Nicholas J; Grenyer, Richard

    2015-07-01

    Development associated with natural gas extraction may have negative effects on wildlife. Here we assessed the effects of natural gas development on the distributions of three sagebrush-obligate birds (Brewer's Sparrow, Spizella breweri; Sagebrush Sparrow, Amphispiza belli; and Sage Thrasher, Oreoscoptes montanus) at a natural gas extraction site in Wyoming, USA. Two drivers of habitat disturbance were investigated: natural gas well pads and roadways. Disturbances were quantified on a small scale (minimum distance to a disturbance) and a large scale (landscape density of a disturbance). Their effects on the study species' distributions were assessed using a multi-scale occupancy model. Minimum distances to wells and roadways were found to not have significant impacts on small-scale occupancy. However, roadway and well density at the landscape-scale significantly impacted the large-scale occupancy of Sagebrush Sparrows and Sage Thrashers. The results confirmed our hypotheses that increasing road density negatively affects the landscape-scale occupancy rates of Sagebrush Sparrow and Sage Thrasher, but did not confirm our hypothesis that increasing well density would negatively impact large-scale occupancy. We therefore suggest that linear features that affect patch size may be more important than point features in determining sagebrush-obligate songbird occupancy when compared to structural effects such as habitat fragmentation and increased predation. We recommend that future well construction be focused along existing roadways, that horizontal drilling be used to reduce the need for additional roads, and that deactivation and restoration of roadways be implemented upon the deactivation of wells, we also recommend a possible mitigation strategy when new roads are to be built. PMID:26485947

  1. Estimating the Impact of US Agriculture Subsidies on Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Eshel, G.; Martin, P. A.

    2006-12-01

    It has been proposed in the popular media that US agricultural subsidies contribute deleteriously to both the American diet and environment. In this view, subsidies render mostly corn-based, animal products and sweeteners artificically cheap, leading to enhanced consumption. Problems accompanying this structure mentioned include enhanced meat, fat and sugar consumption and the associated enhancement of obesity, cardiovascular diseases, type II diabetes and possible various types of cancer, as well as air, soil and water pollution. Often overlooked in these discussions is the potential enhancement of greenhouse gas emissions accompanying this policy-based steering of food consumption toward certain products at the expense of others, possibly more nutritionally and environmentally benign. If such enhancements are in fact borne out by data, the policies that give rise to them will prove to constitute government-sponsored enhancement of greenhouse gas emissions, in contrast to any climate change mitigation efforts. If so, they represent low- hanging fruits in the national effort to reduce greenhouse gas emissions which may one day be launched. Agriculture subsidies impact the emissions of CO2 (by direct energy consumption), nitrous oxide (by land use alteration and manure management), and methane (by ruminant digestion and manure treatment). Quantifying the impacts of agricultural subsidies is complicated by many compounding and conflicting effects (many related to human behavior rather than the natural sciences) and the relatively short data timeseries. For example, subsidy policies change over time, certain subsidy types are introduced or eliminated, food preferences change as nutritional understanding (or propaganda) shift, etc. Despite the difficulties, such quantification is crucial to better estimate the overall effect and variability of dietary choices on greenhouse gas emissions, and ultimately minimize environmental impacts. In this study, we take preliminary

  2. The Impact of Measurement Noise in GPA Diagnostic Analysis of a Gas Turbine Engine

    NASA Astrophysics Data System (ADS)

    Ntantis, Efstratios L.; Li, Y. G.

    2013-12-01

    The performance diagnostic analysis of a gas turbine is accomplished by estimating a set of internal engine health parameters from available sensor measurements. No physical measuring instruments however can ever completely eliminate the presence of measurement uncertainties. Sensor measurements are often distorted by noise and bias leading to inaccurate estimation results. This paper explores the impact of measurement noise on Gas Turbine GPA analysis. The analysis is demonstrated with a test case where gas turbine performance simulation and diagnostics code TURBOMATCH is used to build a performance model of a model engine similar to Rolls-Royce Trent 500 turbofan engine, and carry out the diagnostic analysis with the presence of different levels of measurement noise. Conclusively, to improve the reliability of the diagnostic results, a statistical analysis of the data scattering caused by sensor uncertainties is made. The diagnostic tool used to deal with the statistical analysis of measurement noise impact is a model-based method utilizing a non-linear GPA.

  3. User-Friendly Tool to Calculate Economic Impacts from Coal, Natural Gas, and Wind: The Expanded Jobs and Economic Development Impact Model (JEDI II); Preprint

    SciTech Connect

    Tegen, S.; Goldberg, M.; Milligan, M.

    2006-06-01

    In this paper we examine the impacts of building new coal, gas, or wind plants in three states: Colorado, Michigan, and Virginia. Our findings indicate that local/state economic impacts are directly related to the availability and utilization of local industries and services to build and operate the power plant. For gas and coal plants, the economic benefit depends significantly on whether the fuel is obtained from within the state, out of state, or some combination. We also find that the taxes generated by power plants can have a significant impact on local economies via increased expenditures on public goods.

  4. Ozone Air Quality Impacts of Shale Gas Development in South Texas Urban Areas

    NASA Astrophysics Data System (ADS)

    Chang, C.; Liao, K.

    2013-12-01

    Recent technological advances, mainly horizontal drilling and hydraulic fracturing, and continued drilling in shale, have increased domestic production of oil and gas in the United State (U.S.). However, shale gas developments could also affect the environment and human health, particularly in areas where oil and gas developments are new activities. This study is focused on the impacts of shale gas developing activities on summertime ozone air quality in South Texas urban areas since many of them are already ozone nonattainment areas. We use an integrated approach to investigate the ozone air quality impact of the shale gas development in South Texas urban areas. They are: (1) satellite measurement of precursors, (2) observations of ground-level ozone concentrations, and (3) air mass trajectory modeling. Nitrogen dioxide (NO2) is an important precursor to ozone formation, and summertime average tropospheric nitrogen dioxide (NO2) column densities measured by the National Aeronautics and Space Administration's Ozone Monitoring Instrument increased in the South Texas shale area (i.e., the Eagle Ford Shale area) in 2011 and 2012 as compared to 2008-2010. The U.S. Environmental Protection Agency's ground-level observations showed summertime average and peak ozone (i.e., the 4th highest daily maximum 8-hour average ozone) concentrations slightly increased from 2010 to 2012 in Austin and San Antonio. However, the frequencies of peak ozone concentrations above the 75ppb ozone standard have been significantly increasing since 2011 in Austin and San Antonio. It is expected to increase the possibilities of violating the ozone National Ambient Air Quality Standard (NAAQS) for South Texas urban areas in the future. The results of trajectory modeling showed air masses transported from the southeastern Texas could reach Austin and San Antonio and confirmed that emissions from the Eagle Ford Shale area could affect ozone air quality in South Texas urban areas in 2011 and 2012

  5. Impact of gas bremsstrahlung on synchrotron radiation beamline shielding at the Advanced Photon Source

    SciTech Connect

    Ipe, N.E.; Fasso, A.

    1994-01-01

    The Advanced Photon Source (APS) currently under construction at Argonne National Laboratory will be one of the world`s brightest synchrotron radiation facilities. The storage ring, capable of storing currents up to 300 mA at 7.0 GeV and 200 mA at 7.5 GeV, will produce very intense and energetic synchrotron radiation (E{sub c} = 24 keV for bending magnets and E{sub c} = 37.4 keV for wigglers, where E{sub c} is the critical energy). The synchrotron radiation (SR) beam lines consisting of experimental enclosures and transport lines will have to be shielded against synchrotron radiation and gas bremsstrahlung scattered from beam line components. For insertion devices placed in the straight sections (length = 15 m), the gas bremsstrahlung produced by the interaction of the primary stored beam with residual gas molecules or ions in the storage ring vacuum chamber dominates the SR beam line shielding. The impact of gas bremsstrahlung on the SR beam line shielding is discussed in this paper.

  6. Impact of natural gas extraction on Pah levels in ambient air

    PubMed Central

    Paulik, L. Blair; Donald, Carey E.; Smith, Brian W.; Tidwell, Lane G.; Hobbie, Kevin A.; Kincl, Laurel; Haynes, Erin N.; Anderson, Kim A.

    2015-01-01

    Natural gas extraction, often referred to as “fracking,” has increased rapidly in the U.S. in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped based on distance from each sampler to the nearest active well. PAH levels were highest when samplers were closest to active wells. Additionally, PAH levels closest to natural gas activity were an order of magnitude higher than levels previously reported in rural areas. Sourcing ratios indicate that PAHs were predominantly petrogenic, suggesting that elevated PAH levels were influenced by direct releases from the earth. Quantitative human health risk assessment estimated the excess lifetime cancer risks associated with exposure to the measured PAHs. Closest to active wells, the risk estimated for maximum residential exposure was 2.9 in 10,000, which is above the U.S. EPA's acceptable risk level. Overall, risk estimates decreased 30% when comparing results from samplers closest to active wells to those farthest. This work suggests that natural gas extraction may be contributing significantly to PAHs in air, at levels that are relevant to human health. PMID:25810398

  7. Impact of natural gas extraction on PAH levels in ambient air.

    PubMed

    Paulik, L Blair; Donald, Carey E; Smith, Brian W; Tidwell, Lane G; Hobbie, Kevin A; Kincl, Laurel; Haynes, Erin N; Anderson, Kim A

    2015-04-21

    Natural gas extraction, often referred to as "fracking," has increased rapidly in the U.S. in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped based on distance from each sampler to the nearest active well. PAH levels were highest when samplers were closest to active wells. Additionally, PAH levels closest to natural gas activity were an order of magnitude higher than levels previously reported in rural areas. Sourcing ratios indicate that PAHs were predominantly petrogenic, suggesting that elevated PAH levels were influenced by direct releases from the earth. Quantitative human health risk assessment estimated the excess lifetime cancer risks associated with exposure to the measured PAHs. Closest to active wells, the risk estimated for maximum residential exposure was 2.9 in 10 000, which is above the U.S. EPA's acceptable risk level. Overall, risk estimates decreased 30% when comparing results from samplers closest to active wells to those farthest. This work suggests that natural gas extraction may be contributing significantly to PAHs in air, at levels that are relevant to human health. PMID:25810398

  8. Potential impacts of the Energy Policy Act on electricity and natural gas provider fleets

    SciTech Connect

    Vyas, A.D.; Wang, M.Q.

    1996-03-01

    Section 501 of the 1992 Energy Policy and Conservation Act (EPACT) mandates that alternative-fuel providers who may sell such fuels for transportation uses acquire alternative-fuel vehicles (AFVs). The potential impacts of this mandate on the two largest groups of alternative-fuel providers--electricity and natural gas (NG) providers--are presented. Nationwide, 166 electric-only utility companies, 127 NG-only utility companies, and 55 dual-utility companies will be covered by EPACT. Together, these companies own/operate nearly 122,000 light-duty vehicles in the EPACT-defined metropolitan areas. Some 63 natural gas producers and transporters, which have 9700 light-duty vehicles, are also covered. We project that covered fuel providers will purchase 2710 AFVs in 1996 and 13, 650 AFVs by 2001. We estimate that natural gas companies already have 19.4% of their existing light-duty vehicle stocks as AFVs, dual companies have 10.0%, natural gas producers and transporters have 7. 0%, and electric companies have only 1.6%. If the existing AFVs count toward meeting the Section 501 requirements, NG providers (NG utilities, dual utilities, and NG producers and transporters) will need to make little additional effort, but electric companies will have to make substantial commitments to meet the requirements.

  9. The impact of epicuticular wax on gas-exchange and photoinhibition in Leucadendron lanigerum (Proteaceae)

    NASA Astrophysics Data System (ADS)

    Mohammadian, Mansour A.; Watling, Jennifer R.; Hill, Robert S.

    2007-01-01

    This study investigated the seasonal modification of wax deposition, and the impact of epicuticular wax on gas-exchange as well as photoinhibition in Leucadendron lanigerum, a species from the Proteaceae family with wax-covered leaf surfaces and the stomata also partially occluded by wax. The results of this study demonstrated that the deposition of epicuticular wax in L. lanigerum is dependent on the age of the leaf as well as the season, and generation and regeneration of wax occur mostly in spring while transformation and also degeneration of wax crystals occur in winter. Epicuticular waxes decreased cuticular water loss, but had little impact on leaf reflectance. The temperature of leaves without wax was lower than that of wax-covered leaves, indicating that the rate of transpiration impacted more on leaf temperature than reflectance of light in the PAR range in L. lanigerum. The wax coverage at the entrance of stomata in L. lanigerum increased resistance to gas diffusion and as a consequence decreased stomatal conductance, transpiration and photosynthesis. Also, the results indicated that epicuticular waxes do help prevent photodamage in L. lanigerum, and so this property could benefit plants living in arid environments with high solar radiation.

  10. Minimizing the environmental impact of oil and gas developments in the tropics

    SciTech Connect

    Rosenfeld, A.B.; Gordon, D.L.; Guerin-McManus, M.

    1997-07-01

    The next big frontier for oil and gas development will be the humid tropics, where more than 80% of exploration and production is expected to take place in the next decade. The tropical areas targeted by these operations not only hold large stores of oil and gas, but are also frequently undeveloped and remote, located in or near important and sensitive ecosystems. Within the tropics the most heavily targeted area is the Latin American Neotropics (New World tropics), which include South America, Mesoamerica and the Caribbean. A regionwide move toward privatization of state oil industries, growing liberalization of markets, and contractual incentives for foreign investment make this region a prime target for oil exploration and development. Proper evaluation of available technologies and planning will help determine how and where mitigation efforts should be directed to prevent and control environmental impacts.

  11. Evaluating natural gas development impacts on stream ecosystems in an Upper Colorado River watershed

    NASA Astrophysics Data System (ADS)

    Holloway, J. M.; Bern, C.; Schmidt, T. S.; McDougal, R. R.; Clark, M. L.; Stricker, C. A.; Wolf, R. E.

    2011-12-01

    Oil and gas development in the western United States is increasingly placing at odds the management of two critical natural resources: fossil fuels and water. Muddy Creek, part of the Upper Colorado River watershed, is a semi-arid catchment in a sagebrush steppe ecosystem. Muddy Creek flows throughout the year and includes both perennial and ephemeral tributaries. Primary land use includes livestock grazing, oil and gas development, and recreational activities. A multi-discipline study has been initiated to determine potential impacts of the projected increase of coal bed natural gas development. Hundreds of permits for drilling co-produced waters have been issued, but low energy prices have slowed development. A watershed assessment was conducted in 2010 to determine areas within the watershed that are more susceptible to mobilization of trace elements that occur in soils forming on marine shales. Soil, stream sediment, and water samples were collected and analyzed for major elements and a suite of trace elements, with arsenic and selenium identified as potential elements of concern. A study of benthic and riparian invertebrates is being conducted to evaluate the uptake of these elements into the food web at targeted locations in the Muddy Creek watershed. Continued work will address sources of salinity to Muddy Creek, and ultimately to the Upper Colorado River. Impacts from energy development can include mobilization of naturally occurring sulfate salts through soil disturbance. Formation waters currently discharged to the surface from two failed wells within the watershed will be evaluated for their contribution to salinity, as well as dissolved organic carbon, nitrogen species, and trace elements, to the Upper Colorado River. Upon completion, this study will provide a baseline that can assist in land-use management decisions as oil and gas extraction expands in the Upper Colorado River watershed.

  12. Regional impacts of oil and gas development on ozone formation in the western United States.

    PubMed

    Rodriguez, Marco A; Barna, Michael G; Moore, Tom

    2009-09-01

    The Intermountain West is currently experiencing increased growth in oil and gas production, which has the potential to affect the visibility and air quality of various Class I areas in the region. The following work presents an analysis of these impacts using the Comprehensive Air Quality Model with extensions (CAMx). CAMx is a state-of-the-science, "one-atmosphere" Eulerian photochemical dispersion model that has been widely used in the assessment of gaseous and particulate air pollution (ozone, fine [PM2.5], and coarse [PM10] particulate matter). Meteorology and emissions inventories developed by the Western Regional Air Partnership Regional Modeling Center for regional haze analysis and planning are used to establish an ozone baseline simulation for the year 2002. The predicted range of values for ozone in the national parks and other Class I areas in the western United States is then evaluated with available observations from the Clean Air Status and Trends Network (CASTNET). This evaluation demonstrates the model's suitability for subsequent planning, sensitivity, and emissions control strategy modeling. Once the ozone baseline simulation has been established, an analysis of the model results is performed to investigate the regional impacts of oil and gas development on the ozone concentrations that affect the air quality of Class I areas. Results indicate that the maximum 8-hr ozone enhancement from oil and gas (9.6 parts per billion [ppb]) could affect southwestern Colorado and northwestern New Mexico. Class I areas in this region that are likely to be impacted by increased ozone include Mesa Verde National Park and Weminuche Wilderness Area in Colorado and San Pedro Parks Wilderness Area, Bandelier Wilderness Area, Pecos Wilderness Area, and Wheeler Peak Wilderness Area in New Mexico. PMID:19785277

  13. Safety analysis report for packaging: the ORNL gas-cylinder fire and impact shield

    SciTech Connect

    Evans, J.H.; Levine, D.L.; Eversole, R.E.; Mouring, R.W.

    1983-04-01

    The ORNL gas-cylinder fire and impact shield was designed and fabricated at the Oak Ridge Gaseous Diffusion Plant for the transport of cylinders filled with radioactive gases. The shield was evaluated analytically and experimentally to determine its compliance with the applicable regulations governing containers in which radioactive and fissile materials are transported, and the results are reported herein. Computational and test procedures were used to determine the structural integrity and thermal behavior of the cask relative to the general standards for normal conditions of transport and the standards for hypothetical accident conditions. Results of the evaluation demonstrate that the container is in compliance with the applicable regulations.

  14. The impact of emission standards on the design of aircraft gas turbine engine combustors

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1976-01-01

    The advent of environmental standards for controlling aircraft gas turbine engine emissions has led to a reevaluation of combustor design techniques. Effective emission control techniques have been identified and a wide spectrum of potential applications for these techniques to existing and advanced engines are being considered. Results from advanced combustor concept evaluations and from fundamental experiments are presented and discussed and comparisons are made with existing EPA emission standards and recommended levels for high altitude cruise. The impact that the advanced low emission concepts may impose on future aircraft engine combustor designs and related engine components is discussed.

  15. Electron-Impact Excitation Cross Sections for Modeling Non-Equilibrium Gas

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Liu, Yen; Panesi, Marco; Munafo, Alessandro; Wray, Alan; Carbon, Duane F.

    2015-01-01

    In order to provide a database for modeling hypersonic entry in a partially ionized gas under non-equilibrium, the electron-impact excitation cross sections of atoms have been calculated using perturbation theory. The energy levels covered in the calculation are retrieved from the level list in the HyperRad code. The downstream flow-field is determined by solving a set of continuity equations for each component. The individual structure of each energy level is included. These equations are then complemented by the Euler system of equations. Finally, the radiation field is modeled by solving the radiative transfer equation.

  16. Natural gas and CO2 price variation: impact on the relative cost-efficiency of LNG and pipelines

    PubMed Central

    Ulvestad, Marte; Overland, Indra

    2012-01-01

    This article develops a formal model for comparing the cost structure of the two main transport options for natural gas: liquefied natural gas (LNG) and pipelines. In particular, it evaluates how variations in the prices of natural gas and greenhouse gas emissions affect the relative cost-efficiency of these two options. Natural gas is often promoted as the most environmentally friendly of all fossil fuels, and LNG as a modern and efficient way of transporting it. Some research has been carried out into the local environmental impact of LNG facilities, but almost none into aspects related to climate change. This paper concludes that at current price levels for natural gas and CO2 emissions the distance from field to consumer and the volume of natural gas transported are the main determinants of transport costs. The pricing of natural gas and greenhouse emissions influence the relative cost-efficiency of LNG and pipeline transport, but only to a limited degree at current price levels. Because more energy is required for the LNG process (especially for fuelling the liquefaction process) than for pipelines at distances below 9100 km, LNG is more exposed to variability in the price of natural gas and greenhouse gas emissions up to this distance. If the prices of natural gas and/or greenhouse gas emission rise dramatically in the future, this will affect the choice between pipelines and LNG. Such a price increase will be favourable for pipelines relative to LNG. PMID:24683269

  17. Scoping Study on the Safety Impact of Valve Spacing in Natural Gas Pipelines

    SciTech Connect

    Sulfredge, Charles David

    2007-07-01

    The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration (PHMSA) is responsible for ensuring the safe, reliable, and environmentally sound operation of the nation's natural gas and hazardous liquid pipelines. Regulations adopted by PHMSA for gas pipelines are provided in 49 CFR 192, and spacing requirements for valves in gas transmission pipelines are presented in 49 CFR 192.179. The present report describes the findings of a scoping study conducted by Oak Ridge National Laboratory (ORNL) to assist PHMSA in assessing the safety impact of system valve spacing. Calculations of the pressures, temperatures, and flow velocities during a set of representative pipe depressurization transients were carried out using a one-dimensional numerical model with either ideal gas or real gas properties for the fluid. With both ideal gas and real gas properties, the high-consequence area radius for any resulting fire as defined by Stevens in GRI-00/0189 was evaluated as one measure of the pipeline safety. In the real gas case, a model for convective heat transfer from the pipe wall is included to assess the potential for shut-off valve failures due to excessively low temperatures resulting from depressurization cooling of the pipe. A discussion is also provided of some additional factors by which system valve spacing could affect overall pipeline safety. The following conclusions can be drawn from this work: (1) Using an adaptation of the Stephens hazard radius criteria, valve spacing has a negligible influence on natural gas pipeline safety for the pipeline diameter, pressure range, and valve spacings considered in this study. (2) Over the first 30 s of the transient, pipeline pressure has a far greater effect on the hazard radius calculated with the Stephens criteria than any variations in the transient flow decay profile and the average discharge rate. (3) Other factors besides the Stephens criteria, such as the longer burn time for an

  18. A Gas-Actuated Projectile Launcher for High-Energy Impact Testing of Structures

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R.; Jaunky, Navin; Lawson, Robin E.; Knight, Norman F., Jr.; Lyle, Karen H.

    1999-01-01

    A gas-act,uated penetration device has been developed for high-energy impact testing of structures. The high-energy impact. t,estiiig is for experimental simulation of uncontained engine failures. The non-linear transient finite element, code LS-DYNA3D has been used in the numerical simula.tions of a titanium rectangular blade with a.n aluminum target, plate. Threshold velocities for different combinations of pitch and yaw angles of the impactor were obtained for the impactor-target, t8est configuration in the numerica.1 simulations. Complet,e penet,ration of the target plate was also simulat,ed numerically. Finally, limited comparison of analytical and experimental results is presented for complete penetration of the target by the impactor.

  19. Structural Integrity of Gas-Filled Composite Overwrapped Pressure Vessels Subjected to Orbital Debris Impact

    NASA Astrophysics Data System (ADS)

    Telichev, Igor; Cherniaev, Aleksandr

    Gas-filled pressure vessels are extensively used in spacecraft onboard systems. During operation on the orbit they exposed to the space debris environment. Due to high energies they contain, pressure vessels have been recognized as the most critical spacecraft components requiring protection from orbital debris impact. Major type of pressurized containers currently used in spacecraft onboard systems is composite overwrapped pressure vessels (COPVs) manufactured by filament winding. In the present work we analyze the structural integrity of vessels of this kind in case of orbital debris impact at velocities ranging from 2 to 10 km/s. Influence of such parameters as projectile energy, shielding standoff, internal pressure and filament winding pattern on COPVs structural integrity has been investigated by means of numerical and physical experiments.

  20. 76 FR 82275 - Notice of Availability of a Draft Environmental Impact Statement for Effects of Oil and Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ... OCSLA. Scoping On February 8, 2010, NMFS provided public notice (75 FR 6175) that it would prepare an... Environmental Impact Statement for Effects of Oil and Gas Activities in the Arctic Ocean AGENCY: National Marine... announces the availability of the ``Draft Environmental Impact Statement (DEIS) for the Effects of Oil...

  1. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    SciTech Connect

    David R. Farley

    2010-08-19

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N≥3, with a rotational temperature between the wall and feed gas temperatures. The N=0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  2. BAG: A code for predicting the performance of a gas bag impact attenuation system for the PATHFINDER lander

    SciTech Connect

    Cole, J.K.; Waye, D.E.

    1993-11-01

    The National Aeronautics and Space Administration (NASA) is planning to launch a network of scientific probes to Mars beginning in late 1996. The precursor to this network will be PATHFINDER. Decelerating PATHFINDER from the high speed of its approach to Mars will require the use of several deceleration techniques working in series. The Jet Propulsion Laboratory (JPL) has proposed that gas bags be used to cushion the payload`s ground impact on Mars. This report presents the computer code, BAG, which has been developed to calculate the pneumatic performance of gas bag impact attenuators and the one-dimensional rigid-body dynamic performance of a payload during ground impact.

  3. Climate change impacts and greenhouse gas mitigation effects on U.S. water quality

    NASA Astrophysics Data System (ADS)

    Boehlert, Brent; Strzepek, Kenneth M.; Chapra, Steven C.; Fant, Charles; Gebretsadik, Yohannes; Lickley, Megan; Swanson, Richard; McCluskey, Alyssa; Neumann, James E.; Martinich, Jeremy

    2015-09-01

    Climate change will have potentially significant effects on freshwater quality due to increases in river and lake temperatures, changes in the magnitude and seasonality of river runoff, and more frequent and severe extreme events. These physical impacts will in turn have economic consequences through effects on riparian development, river and reservoir recreation, water treatment, harmful aquatic blooms, and a range of other sectors. In this paper, we analyze the physical and economic effects of changes in freshwater quality across the contiguous U.S. in futures with and without global-scale greenhouse gas mitigation. Using a water allocation and quality model of 2119 river basins, we estimate the impacts of various projected emissions outcomes on several key water quality indicators, and monetize these impacts with a water quality index approach. Under mitigation, we find that water temperatures decrease considerably and that dissolved oxygen levels rise in response. We find that the annual economic impacts on water quality of a high emissions scenario rise from 1.4 billion in 2050 to 4 billion in 2100, leading to present value mitigation benefits, discounted at 3%, of approximately $17.5 billion over the 2015-2100 period.

  4. Advanced diagnostics for impact-flash spectroscopy on light-gas guns.

    SciTech Connect

    Breiland, William George; Reinhart, William Dodd; Miller, Paul Albert; Brown, Justin L.; Thornhill, Tom Finley, III; Mangan, Michael A.; Shaner, Eric Arthur; Chhabildas, Lalit Chandra; Grine, Albert D.; Wanke, Michael Clement; Alexander, C. Scott

    2007-03-01

    This study is best characterized as new technology development for implementing new sensors to investigate the optical characteristics of a rapidly expanding debris cloud resulting from hypervelocity impact regimes of 7 to 11 km/s. Our gas guns constitute a unique test bed that match operational conditions relevant to hypervelocity impact encountered in space engagements. We have demonstrated the use of (1) terahertz sensors, (2) silicon diodes for visible regimes, (3) germanium and InGaAs sensors for the near infrared regimes, and (4) the Sandia lightning detectors which are similar to the silicon diodes described in 2. The combination and complementary use of all these techniques has the strong potential of ''thermally'' characterizing the time dependent behavior of the radiating debris cloud. Complementary spectroscopic measurements provide temperature estimates of the impact generated debris by fitting its spectrum to a blackbody radiation function. This debris is time-dependent as its transport/expansion behavior is changing with time. The rapid expansion behavior of the debris cools the cloud rapidly, changing its thermal/temperature characteristics with time. A variety of sensors that span over a wide spectrum, varying from visible regime to THz frequencies, now gives us the potential to cover the impact over a broader temporal regime starting from high pressures (Mbar) high-temperatures (eV) to low pressures (mbar) low temperatures (less than room temperature) as the debris expands and cools.

  5. Using a Gas-Phase Tracer Test to Characterize the Impact of Landfill Gas Generation on Advective-Dispersive Transport of VOCs in the Vadose Zone

    PubMed Central

    Monger, Gregg R.; Duncan, Candice Morrison; Brusseau, Mark L.

    2015-01-01

    A gas-phase tracer test (GTT) was conducted at a landfill in Tucson, AZ, to help elucidate the impact of landfill gas generation on the transport and fate of chlorinated aliphatic volatile organic contaminants (VOCs). Sulfur hexafluoride (SF6) was used as the non-reactive gas tracer. Gas samples were collected from a multiport monitoring well located 15.2 m from the injection well, and analyzed for SF6, CH4, CO2, and VOCs. The travel times determined for SF6 from the tracer test are approximately two to ten times smaller than estimated travel times that incorporate transport by only gas-phase diffusion. In addition, significant concentrations of CH4 and CO2 were measured, indicating production of landfill gas. Based on these results, it is hypothesized that the enhanced rates of transport observed for SF6 are caused by advective transport associated with landfill gas generation. The rates of transport varied vertically, which is attributed to multiple factors including spatial variability of water content, refuse mass, refuse permeability, and gas generation. PMID:26380532

  6. The Impact of ENSO on Trace Gas Composition in the Upper Troposphere to Lower Stratosphere

    NASA Astrophysics Data System (ADS)

    Oman, Luke; Douglass, Anne; Ziemke, Jerald; Waugh, Darryn

    2016-04-01

    The El Nino-Southern Oscillation (ENSO) is the dominant mode of interannual variability in the tropical troposphere and its effects extend well into the stratosphere. Its impact on atmospheric dynamics and chemistry cause important changes to trace gas constituent distributions. A comprehensive suite of satellite observations, reanalyses, and chemistry climate model simulations are illuminating our understanding of processes like ENSO. Analyses of more than a decade of observations from NASA's Aura and Aqua satellites, combined with simulations from the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM) and other Chemistry Climate Modeling Initiative (CCMI) models, and the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) reanalysis have provided key insights into the response of atmospheric composition to ENSO. While we will primarily focus on ozone and water vapor responses in the upper troposphere to lower stratosphere, the effects of ENSO ripple through many important trace gas species throughout the atmosphere. The very large 2015-2016 El Nino event provides an opportunity to closely examine these impacts with unprecedented observational breadth. An improved quantification of natural climate variations, like those from ENSO, is needed to detect and quantify anthropogenic climate changes.

  7. The impact of lower sea-ice extent on Arctic greenhouse-gas exchange

    USGS Publications Warehouse

    Parmentier, Frans-Jan W.; Christensen, Torben R.; Sørensen, Lise Lotte; Rysgaard, Søren; McGuire, A. David; Miller, Paul A.; Walker, Donald A.

    2013-01-01

    In September 2012, Arctic sea-ice extent plummeted to a new record low: two times lower than the 1979–2000 average. Often, record lows in sea-ice cover are hailed as an example of climate change impacts in the Arctic. Less apparent, however, are the implications of reduced sea-ice cover in the Arctic Ocean for marine–atmosphere CO2 exchange. Sea-ice decline has been connected to increasing air temperatures at high latitudes. Temperature is a key controlling factor in the terrestrial exchange of CO2 and methane, and therefore the greenhouse-gas balance of the Arctic. Despite the large potential for feedbacks, many studies do not connect the diminishing sea-ice extent with changes in the interaction of the marine and terrestrial Arctic with the atmosphere. In this Review, we assess how current understanding of the Arctic Ocean and high-latitude ecosystems can be used to predict the impact of a lower sea-ice cover on Arctic greenhouse-gas exchange.

  8. The impact of 'Cash for Clunkers' on greenhouse gas emissions: a life cycle perspective

    NASA Astrophysics Data System (ADS)

    Lenski, Shoshannah M.; Keoleian, Gregory A.; Bolon, Kevin M.

    2010-10-01

    One of the goals of the US Consumer Assistance to Recycle and Save (CARS) Act of 2009, more commonly known as 'Cash for Clunkers', was to improve the US vehicle fleet fuel efficiency. Previous studies of the program's environmental impact have focused mainly on the effect of improved fuel economy, and the resulting reductions in fuel use and emissions during the vehicle use phase. We propose and apply a method for analyzing the net effect of CARS on greenhouse gas emissions from a full vehicle life cycle perspective, including the impact of premature production and retirement of vehicles. We find that CARS had a one-time effect of preventing 4.4 million metric tons of CO2-equivalent emissions, about 0.4% of US annual light-duty vehicle emissions. Of these, 3.7 million metric tons are avoided during the period of the expected remaining life of the inefficient 'clunkers'. 1.5 million metric tons are avoided as consumers purchase vehicles that are more efficient than their next replacement vehicle would otherwise have been. An additional 0.8 million metric tons are emitted as a result of premature manufacturing and disposal of vehicles. These results are sensitive to the remaining lifetime of the 'clunkers' and to the fuel economy of new vehicles in the absence of CARS, suggesting important considerations for policymakers deliberating on the use of accelerated vehicle retirement programs as a part of the greenhouse gas emissions policy.

  9. High-Impact Actions for Individuals to Reduce Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Nicholas, K. A.; Wynes, S. C.

    2015-12-01

    Climate change is the result of greenhouse gas accumulation in the atmosphere, which records the aggregation of billions of individual decisions. While systemic and structural changes receive great attention for addressing climate change, the contribution that individual citizens can make is often overlooked, especially in developed countries where per-capita emissions are highest. Here we consider a broad range of individual lifestyle choices and calculate their potential to reduce greenhouse gas emissions. We find that four widely applicable high-impact actions have the potential to reduce personal emissions by more than 1 tonne CO2-equivalent per year: having one fewer child (59.2 tonnes of reductions), living car-free (2.3 tonnes), avoiding airplane travel (1.5 tonnes per flight) and eating a plant-based diet (0.82 tonnes). These actions have much greater potential to reduce emissions than commonly promoted strategies like recycling (4 times less effective than a plant-based diet) or changing lightbulbs (8 times). However, high school textbooks from Canada and government resources from the EU, USA, Canada, and Australia largely fail to mention these actions, instead focusing on incremental changes with much smaller potential impact. We conclude that climate policy should focus not only on national and international targets, but also on encouraging responsible behaviour, especially for adolescents who will grow up in the era of climate change and are poised to establish a lifelong pattern of sustainable lifestyle choices.

  10. Localising livestock protein feed production and the impact on land use and greenhouse gas emissions.

    PubMed

    Sasu-Boakye, Y; Cederberg, C; Wirsenius, S

    2014-08-01

    Livestock farmers in Sweden usually grow feed grains for livestock but import protein feed from outside Sweden. Aside from the economic implications, some environmental issues are associated with this practice. We used life cycle assessment to evaluate the impact of local protein feed production on land use and greenhouse gas emissions, compared with the use of imported protein feed, for pig meat and dairy milk produced in Sweden. Our results showed that local production reduced greenhouse gas emissions by 4.5% and 12%, respectively, for pigs and dairy cows. Land use for feed production in Sweden increased by 11% for pigs and 25% for dairy cows, but total land use decreased for pig production and increased for dairy milk production. Increased protein feed cultivation in Sweden decreased inputs needed for animal production and improved some ecological processes (e.g. nutrient recycling) of the farm systems. However, the differences in results between scenarios are relatively small and influenced to an extent by methodological choices such as co-product allocation. Moreover, it was difficult to assess the contribution of greenhouse emissions from land use change. The available accounting methods we applied did not adequately account for the potential land use changes and in some cases provided conflicting results. We conclude that local protein feed production presents an opportunity to reduce greenhouse gas emissions but at a cost of increasing land occupation in Sweden for feed production. PMID:26263191

  11. Source apportionment of atmospheric PAHs and their toxicity using PMF: Impact of gas/particle partitioning

    NASA Astrophysics Data System (ADS)

    Gao, Bo; Wang, Xin-Ming; Zhao, Xiu-Ying; Ding, Xiang; Fu, Xiao-Xin; Zhang, Yan-Li; He, Quan-Fu; Zhang, Zhou; Liu, Teng-Yu; Huang, Zou-Zhao; Chen, Lai-Guo; Peng, Yan; Guo, Hai

    2015-02-01

    24-h PM2.5 samples were simultaneously collected at six sites in a subtropical city of South China during November-December, 2009. Particle-phase concentrations of polycyclic aromatic hydrocarbons (PAHs) and organic tracers such as hopanes for vehicular emissions (VE), levoglucosan for biomass burning (BB) and picene for coal combustion (CC) were determined. Meanwhile, their gas-phase concentrations were calculated from gas/particle (G/P) partitioning theory using the particle-phase concentrations. The 4 ring PAHs (fluoranthene to chrysene) had lower particle-phase fractions (10%-79%) than other species. Estimated BaPeq and lifetime cancer risk for particle-only (P-only) vs gas + particle (G + P) data sets showed similar values, indicating PAHs with 5-7 rings dominated the carcinogenicity of PAHs. Positive Matrix Factorization (PMF) was applied on both P-only and G + P data sets to estimate the source contributions to PAHs and their toxicity. Three common sources were identified: VE, BB and CC, with CC as the most significant source for both particulate (58%) and total (G + P, 40%) PAHs. While CC exhibited consistent contributions to BaPeq for P-only (66%) vs G + P (62%) solutions, VE and BB contributions were under- and overestimated by 68% and 47%, respectively by the P-only solution, as compared to the G + P solution. The results provide an insight on the impact of G/P partitioning on the source apportionment of PAHs and their toxicity.

  12. Predictions of the Impacts of Future Marcellus Shale Natural Gas Development on Regional Ozone

    NASA Astrophysics Data System (ADS)

    Roy, A.; Adams, P. J.; Robinson, A. L.

    2012-12-01

    Recent discovery of shale gas reserves, combined with advances in drilling and fracturing technology, are leading to extensive development of natural gas in the Marcellus Shale formation which underlies parts of Pennsylvania, West Virginia, Ohio and New York. To assess the impacts of this development on regional air quality, we have constructed a VOC, NOx and PM2.5 emissions inventory for the development and production of gas from the Marcellus formation. In 2020, we estimate that Marcellus activities will contribute about 12% to both regional NOx and VOC emissions. These numbers were obtained as a best estimate (mean) from a distribution obtained through several Monte Carlo runs. We speciated these emissions for use in a 3-D chemical transport model (PMCAMx) to simulate their effects on regional ozone. The projected Marcellus emissions for 2020 were added to a 2007 base inventory developed from the NEI. We have performed multiple simulations to investigate the effects of Marcellus development on regional air quality. The model predicts significant ozone changes in the Marcellus region with a uniform increase of few ppb across a wide region of the Northeast. Sensitivity studies are being performed to investigate the effects of emissions controls and sensitivity to VOC and NOx emissions.

  13. Impact origin of the Avak structure, Arctic Alaska, and genesis of the Barrow gas fields

    SciTech Connect

    Kirschner, C.E.; Grantz, A. )

    1990-05-01

    Geophysical and subsurface geologic data confirm that the Avak structure, which underlies the coastal plain 12 km southeast of Barrow, is an impact crater. The structure is a roughly circular area of chaotically deformed Upper Triassic to Lower Cretaceous sedimentary rocks 8 km in diameter bounded by a ring of anastomozing, inwardly dipping, listric normal faults. Beyond the ring, these rocks are almost flat. Basement is strongly deformed Ordovician and Silurian argillite. Strong density and seismic velocity contrast between the argillite and the overlying strata produce gravity and seismic reflection signatures that define ring anticlines around the disturbed zone and a structural high at its center. The Mesozoic strata are about 760 m thick in the adjacent Barrow gas fields, where the Neocomian pebble shale unit and the gas-producing Lower Jurassic Barrow sandstone lie at average subsea depths of 438 m and 670 m, respectively. In the Avak well, drilled on the central high, the pebble shale unit and Barrow sandstone lie near the surface, documenting more than 500 m of uplift at the high. The cores in this well also show steep dips (30-90{degree}), abundant tectonic breccia with argillite clasts 90 m above basement, fractured quartz grains, and shatter cones resembling those found in well-documented meteorite craters. Stratigraphic data suggest that the Avak meteorite struck a late Early Cretaceous marine shelf, produced peripheral highs that trapped gas in the Barrow fields, and triggered massive landslides on the adjacent outer shelf. The age of the landslides dates the impact at about 105 Ma.

  14. Impact of Variations on 1-D Flow in Gas Turbine Engines via Monte Carlo Simulations

    NASA Technical Reports Server (NTRS)

    Ngo, Khiem Viet; Tumer, Irem

    2004-01-01

    The unsteady compressible inviscid flow is characterized by the conservations of mass, momentum, and energy; or simply the Euler equations. In this paper, a study of the subsonic one-dimensional Euler equations with local preconditioning is presented using a modal analysis approach. Specifically, this study investigates the behavior of airflow in a gas turbine engine using the specified conditions at the inflow and outflow boundaries of the compressor, combustion chamber, and turbine, to determine the impact of variations in pressure, velocity, temperature, and density at low Mach numbers. Two main questions motivate this research: 1) Is there any aerodynamic problem with the existing gas turbine engines that could impact aircraft performance? 2) If yes, what aspect of a gas turbine engine could be improved via design to alleviate that impact and to optimize aircraft performance? This paper presents an initial attempt to model the flow behavior in terms of their eigenfrequencies subject to the assumption of the uncertainty or variation (perturbation). The flow behavior is explored using simulation outputs from a customer-deck model obtained from Pratt & Whitney. Variations of the main variables (i.e., pressure, temperature, velocity, density) about their mean states at the inflow and outflow boundaries of the compressor, combustion chamber, and turbine are modeled. Flow behavior is analyzed for the high-pressure compressor and combustion chamber utilizing the conditions on their left and right boundaries. In the same fashion, similar analyses are carried out for the high-pressure and low-pressure turbines. In each case, the eigenfrequencies that are obtained for different boundary conditions are examined closely based on their probabilistic distributions, a result of a Monte Carlo 10,000 sample simulation. Furthermore, the characteristic waves and wave response are analyzed and contrasted among different cases, with and without preconditioners. The results reveal

  15. Air Impacts of Unconventional Natural Gas Development: A Barnett Shale Case Study

    NASA Astrophysics Data System (ADS)

    Moore, C. W.; Zielinska, B.; Campbell, D.; Fujita, E.

    2013-12-01

    Radiello samplers. In addition, weekly PM2.5 samples were collected on Teflon and quartz filters that were analyzed for mass and elements (Teflon filters), for organic and elemental carbon (OC and EC) by thermal/optical reflectance (TOR) method and for polycyclic aromatic hydrocarbons (PAH) using a gas chromatography/mass spectrometry (GC/MS) technique (quartz filters).VOC emissions from condensate tanks were largely low molecular weight hydrocarbons, however these tanks were enhancing local benzene concentrations mostly through malfunctioning valves. PAH concentrations were low (in pg m-3 range) but the average PAH concentration profiles (higher fraction of methylated PAHs) indicated an influence of compressor engine exhausts and increased diesel transportation traffic. These measurements, however, only represent a small 'snap-shot' of the overall emissions picture from this area. For instance during this one month study, the compressor station was predominantly downwind of the community and this may not be the case in other times of the year. Long-term study of these systems, especially in areas that have yet to experience this type of exploration, but will in the future, is needed to truly evaluate the air impacts of unconventional natural gas development.

  16. Simulation of the impact of thunderstorm activity on atmospheric gas composition

    NASA Astrophysics Data System (ADS)

    Smyshlyaev, S. P.; Mareev, E. A.; Galin, V. Ya.

    2010-08-01

    A chemistry-climate model of the lower and middle atmosphere has been used to estimate the sensitivity of the atmospheric gas composition to the rate of thunderstorm production of nitrogen oxides at upper tropospheric and lower stratospheric altitudes. The impact that nitrogen oxides produced by lightning have on the atmospheric gas composition is treated as a subgrid-scale process and included in the model parametrically. The natural uncertainty in the global production rate of nitrogen oxides in lightning flashes was specified within limits from 2 to 20 Tg N/year. Results of the model experiments have shown that, due to the variability of thunderstorm-produced nitrogen oxides, their concentration in the upper troposphere and lower stratosphere can vary by a factor of 2 or 3, which, given the influence of nitrogen oxides on ozone and other gases, creates the potential for a strong perturbation of the atmospheric gas composition and thermal regime. Model calculations have shown the strong sensitivity of ozone and the OH hydroxyl to the amount of lightning nitrogen oxides at different atmospheric altitudes. These calculations demonstrate the importance of nitrogen oxides of thunderstorm origin for the balance of atmospheric odd ozone and gases linked to it, such as ozone and hydroxyl radicals. Our results demonstrate that one important task is to raise the accuracy of estimates of the rate of nitrogen oxide production by lightning discharges and to use physical parametrizations that take into account the local lightning effects and feedbacks arising in this case rather than climatological data in models of the gas composition and general circulation of the atmosphere.

  17. The potential near-source ozone impacts of upstream oil and gas industry emissions.

    PubMed

    Olaguer, Eduardo P

    2012-08-01

    Increased drilling in urban areas overlying shale formations and its potential impact on human health through decreased air quality make it important to estimate the contribution of oil and gas activities to photochemical smog. Flares and compressor engines used in natural gas operations, for example, are large sources not only of NOx but also offormaldehyde, a hazardous air pollutant and powerful ozone precursor We used a neighborhood scale (200 m horizontal resolution) three-dimensional (3D) air dispersion model with an appropriate chemical mechanism to simulate ozone formation in the vicinity ofa hypothetical natural gas processing facility, based on accepted estimates of both regular and nonroutine emissions. The model predicts that, under average midday conditions in June, regular emissions mostly associated with compressor engines may increase ambient ozone in the Barnett Shale by more than 3 ppb beginning at about 2 km downwind of the facility, assuming there are no other major sources of ozone precursors. Flare volumes of 100,000 cubic meters per hour ofnatural gas over a period of 2 hr can also add over 3 ppb to peak 1-hr ozone somewhatfurther (>8 km) downwind, once dilution overcomes ozone titration and inhibition by large flare emissions of NOx. The additional peak ozone from the hypothetical flare can briefly exceed 10 ppb about 16 km downwind. The enhancements of ambient ozone predicted by the model are significant, given that ozone control strategy widths are of the order of a few parts per billion. Degrading the horizontal resolution of the model to 1 km spuriously enhances the simulated ozone increases by reducing the effectiveness of ozone inhibition and titration due to artificial plume dilution. PMID:22916444

  18. Air Quality Impacts of Greenhouse Gas Mitigation Technologies in the Power Generation and Transportation Sectors

    NASA Astrophysics Data System (ADS)

    Mac Kinnon, Michael

    Future efforts to mitigate the harmful impacts of climate change will include transitions to alternative technologies and fuels targeting reductions in greenhouse gas (GHG) emissions. Currently, economic sectors of greatest concern include transportation and power generation, which combined contribute over half of total U.S. GHG emissions. In addition to GHGs, displacement of conventional energy strategies will impact the emissions of various pollutant species with human health and environmental risks due to common generation processes and sources. In order to fully investigate the air quality (AQ) impacts of deploying various GHG mitigation technologies and fuels in coming decades, spatially and temporally resolved pollutant emissions fields are developed and utilized as input for simulations of atmospheric chemistry and transport via an advanced AQ model. Three areas of the U.S. are chosen for regional analyses in the year 2055. In order to characterize the evolution of regional energy sector emission drivers from current levels, a Base Case is developed that is representative of progression in the absence of aggressive GHG mitigation efforts. To facilitate comparison, alternative scenarios are developed to explore the effects of shifts in technologies, fuels, or behavior with the potential to mitigate GHG emissions. Scenarios are represented by generated spatially and temporally resolved emission fields and evaluated for impacts on primary and secondary air pollutant concentrations. Significant variation in energy profiles, demands, and constraints (e.g., regulatory statutes) between study domains yields significant differences in regional impacts. The magnitude of AQ improvements depends on baseline emission levels and spatial and temporal emission patterns. In addition, the current focus on reducing emissions from the targeted sectors increases the importance of emissions from other areas and sectors.

  19. Environmental health impacts of unconventional natural gas development: a review of the current strength of evidence.

    PubMed

    Werner, Angela K; Vink, Sue; Watt, Kerrianne; Jagals, Paul

    2015-02-01

    Rapid global expansion of unconventional natural gas development (UNGD) raises environmental health concerns. Many studies present information on these concerns, yet the strength of epidemiological evidence remains tenuous. This paper is a review of the strength of evidence in scientific reporting of environmental hazards from UNGD activities associated with adverse human health outcomes. Studies were drawn from peer-reviewed and grey literature following a systematic search. Five databases were searched for studies published from January 1995 through March 2014 using key search terms relevant to environmental health. Studies were screened, ranked and then reviewed according to the strength of the evidence presented on adverse environmental health outcomes associated with UNGD. The initial searches yielded >1000 studies, but this was reduced to 109 relevant studies after the ranking process. Only seven studies were considered highly relevant based on strength of evidence. Articles spanned several relevant topics, but most focussed on impacts on typical environmental media, such as water and air, with much of the health impacts inferred rather than evidenced. Additionally, the majority of studies focussed on short-term, rather than long-term, health impacts, which is expected considering the timeframe of UNGD; therefore, very few studies examined health outcomes with longer latencies such as cancer or developmental outcomes. Current scientific evidence for UNGD that demonstrates associations between adverse health outcomes directly with environmental health hazards resulting from UNGD activities generally lacks methodological rigour. Importantly, however, there is also no evidence to rule out such health impacts. While the current evidence in the scientific research reporting leaves questions unanswered about the actual environmental health impacts, public health concerns remain intense. This is a clear gap in the scientific knowledge that requires urgent attention

  20. A stream-based methane monitoring approach for evaluating groundwater impacts associated with unconventional gas development.

    PubMed

    Heilweil, Victor M; Stolp, Bert J; Kimball, Briant A; Susong, David D; Marston, Thomas M; Gardner, Philip M

    2013-01-01

    Gaining streams can provide an integrated signal of relatively large groundwater capture areas. In contrast to the point-specific nature of monitoring wells, gaining streams coalesce multiple flow paths. Impacts on groundwater quality from unconventional gas development may be evaluated at the watershed scale by the sampling of dissolved methane (CH4 ) along such streams. This paper describes a method for using stream CH4 concentrations, along with measurements of groundwater inflow and gas transfer velocity interpreted by 1-D stream transport modeling, to determine groundwater methane fluxes. While dissolved ionic tracers remain in the stream for long distances, the persistence of methane is not well documented. To test this method and evaluate CH4 persistence in a stream, a combined bromide (Br) and CH4 tracer injection was conducted on Nine-Mile Creek, a gaining stream in a gas development area in central Utah. A 35% gain in streamflow was determined from dilution of the Br tracer. The injected CH4 resulted in a fivefold increase in stream CH4 immediately below the injection site. CH4 and δ(13) CCH4 sampling showed it was not immediately lost to the atmosphere, but remained in the stream for more than 2000 m. A 1-D stream transport model simulating the decline in CH4 yielded an apparent gas transfer velocity of 4.5 m/d, describing the rate of loss to the atmosphere (possibly including some microbial consumption). The transport model was then calibrated to background stream CH4 in Nine-Mile Creek (prior to CH4 injection) in order to evaluate groundwater CH4 contributions. The total estimated CH4 load discharging to the stream along the study reach was 190 g/d, although using geochemical fingerprinting to determine its source was beyond the scope of the current study. This demonstrates the utility of stream-gas sampling as a reconnaissance tool for evaluating both natural and anthropogenic CH4 leakage from gas reservoirs into groundwater and surface water

  1. Methane and its Stable Isotope Signature Across Pennsylvania: Assessing the Potential Impacts of Natural Gas Development and Agriculture

    NASA Astrophysics Data System (ADS)

    Ramos-Garcés, F.; Fuentes, J. D.; Grannas, A. M.; Martins, D. K.

    2012-12-01

    Methane is an important greenhouse gas with a global warming potential 72 times that of carbon dioxide (20 year time horizon). Many recent efforts have been focused on improving our understanding of methane sources to the atmosphere and better quantifying the atmospheric methane budget. Increased natural gas exploration, particularly associated with shale gas drilling, has been hypothesized to be a potential source of atmospheric methane during well development and also due to fugitive emissions from operational well sites and pipelines. For a six-day period in June 2012, measurements of methane and its stable isotope signature were obtained from a mobile measurement platform using cavity ringdown spectroscopy. Transects from southwestern to northeastern Pennsylvania were studied, with samples obtained in rural, forested, urban, farm-impacted and well-impacted sites. Particular emphasis was placed on performing air sampling in the vicinity of natural gas wells under development, just completed, and in full operation. In the rural atmosphere, away from cattle farms and natural gas systems, the ambient levels of methane were around 1.75 ppm. Near and around gas wells under development, ambient methane levels resembled those found in the rural atmosphere. In some cases, the atmosphere was enriched with methane (up to 2.2 ppm) in areas near old wells and existing pipelines. Ambient methane levels around cattle farms were significantly enhanced, with mixing ratios reaching about 4 ppm. We will discuss here the impact of both gas well development and agricultural activities on observed methane concentrations and stable isotope signatures.

  2. Impact resistance of lightweight hybrid structures for gas turbine engine fan containment applications

    NASA Astrophysics Data System (ADS)

    Hebsur, Mohan G.; Noebe, Ronald D.; Revilock, Duane M.

    2003-08-01

    The ballistic impact resistance of hybrid composite sandwich structures was evaluated with the ultimate goal of developing new materials or structures for potential gas turbine engine, fan containment applications. The sandwich structures investigated consisted of GLARE-5 (Aviation Equipment, Inc., Costa Mesa, CA) laminates as face sheets with lightweight cellular metallic materials such as honeycomb, foam, and lattice block as a core material. The impact resistance of these hybrid sandwich structures was compared with GLARE-5 laminates and 2024-T3 Al sheets, which were tested as a function of areal weight (material thickness). The GLARE-5 laminates exhibited comparable impact properties to that of 2024-T3 Al at low areal weights, even though there were significant differences in the static tensile properties of these materials. The GLARE-5, however, did have a greater ballistic limit than straight aluminum sheet at higher areal weights. Furthermore, there is up to a 25% advantage in ballistic limit for the GLARE-5/foam sandwich structures compared with straight 2024-T3 Al. But no advantage in ballistic limit was observed between any of the hybrid sandwich structures and thicker versions of GLARE-5. Recommendations for future work are provided, based on these preliminary data.

  3. Impact Resistance of Lightweight Hybrid Structures for Gas Turbine Engine Fan Containment Applications

    NASA Technical Reports Server (NTRS)

    Hebsur, Mohan G.; Noebe, Ronald D.; Revilock, Duane M.

    2003-01-01

    The ballistic impact resistance of hybrid composite sandwich structures was evaluated with the ultimate goal of developing new materials or structures for potential gas turbine engine fan containment applications. The sandwich structures investigated consisted of GLARE-5 laminates as face sheets with lightweight cellular metallic materials such as honeycomb, foam, and lattice block as a core material. The impact resistance of these hybrid sandwich structures was compared to GLARE-5 laminates and 2024-T3 Al sheet, which were tested as a function of areal weight (material thickness). The GLARE-5 laminates exhibited comparable impact properties to that of 2024-T3 Al at low areal weights, even though there were significant differences in the static tensile properties of these materials. The GLARE-5, however, did have a greater ballistic limit than straight aluminum sheet at higher areal weights. Furthermore, there is up to a 25% advantage in ballistic limit for the GLARE-5/foam sandwich structures compared to straight 2024-T3 Al. But no advantage in ballistic limit was observed between any of the hybrid sandwich structures and thicker versions of GLARE-5. Recommendations for future work are provided, based on these preliminary data.

  4. A review of water and greenhouse gas impacts of unconventional natural gas development in the United States

    SciTech Connect

    Arent, Doug; Logan, Jeff; Macknick, Jordan; Boyd, William; Medlock , Kenneth; O'Sullivan, Francis; Edmonds, James A.; Clarke, Leon E.; Huntington, Hill; Heath, Garvin; Statwick, Patricia M.; Bazilian, Morgan

    2015-01-01

    This paper reviews recent developments in the production and use of unconventional natural gas in the United States with a focus on water and greenhouse gas emission implications. If unconventional natural gas in the U.S. is produced responsibly, transported and distributed with little leakage, and incorporated into integrated energy systems that are designed for future resiliency, it could play a significant role in realizing a more sustainable energy future; however, the increased use of natural gas as a substitute for more carbon intensive fuels will alone not substantially alter world carbon dioxide concentration projections.

  5. The impact of soil amendments on greenhouse gas emissions: a comprehensive life cycle assessment approach

    NASA Astrophysics Data System (ADS)

    DeLonge, M. S.; Ryals, R.; Silver, W. L.

    2011-12-01

    Soil amendments, such as compost and manure, can be applied to grasslands to improve soil conditions and enhance aboveground net primary productivity. Applying such amendments can also lead to soil carbon (C) sequestration and, when materials are diverted from waste streams (e.g., landfills, manure lagoons), can offset greenhouse gas (GHG) emissions. However, amendment production and application is also associated with GHG emissions, and the net impact of these amendments remains unclear. To investigate the potential for soil amendments to reduce net GHG emissions, we developed a comprehensive, field-scale life cycle assessment (LCA) model. The LCA includes GHG (i.e., CO2, CH4, N2O) emissions of soil amendment production, application, and ecosystem response. Emissions avoided by diverting materials from landfills or manure management systems are also considered. We developed the model using field observations from grazed annual grassland in northern California (e.g., soil C; above- and belowground net primary productivity; C:N ratios; trace gas emissions from soils, manure piles, and composting), CENTURY model simulations (e.g., long-term soil C and trace gas emissions from soils under various land management strategies), and literature values (e.g., GHG emissions from transportation, inorganic fertilizer production, composting, and enteric fermentation). The LCA quantifies and contrasts the potential net GHG impacts of applying compost, manure, and commercial inorganic fertilizer to grazing lands. To estimate the LCA uncertainty, sensitivity tests were performed on the most widely ranging or highly uncertain parameters (e.g., compost materials, landfill emissions, manure management system emissions). Finally, our results are scaled-up to assess the feasibility and potential impacts of large-scale adoption of soil amendment application as a land-management strategy in California. Our base case results indicate that C sinks and emissions offsets associated with

  6. Using CQIM{trademark} to evaluate the performance and economic impacts of gas co-firing at Conesville Unit 3

    SciTech Connect

    Arroyo, J.A.; Pratapas, J.M.; Bleier, R.

    1996-12-31

    The Coal Quality Impact Model (CQIM{trademark}) was used to perform a case study on the performance and economic impacts of natural gas co-firing at American Electric Power`s Conesville Unit 3, a unit that was originally designed to burn coal. CQIM offers a quick, cost-effective solution to the performance and economic issues not normally considered when the interrelationships between performance improvements and penalties and busbar generation costs are examined. For this case study, gas co-firing was found to be economically advantageous over coal firing for Conesville Unit 3. The design coal was evaluated at 0, 10, 25, 50, and 75 percent gas co-firing at full-load conditions. The effect of gas co-firing on unit performance was a decrease in auxiliary power requirements and boiler efficiency as the amount of gas co-firing increased. Due to the reduction in boiler efficiency, the net unit heat rate increased as the amount of gas co-firing increased. The worsening of the net unit heat rate was offset by an improvement in availability, auxiliary power, and SO{sub 2} emissions as the percentage of gas co-firing was increased. On the basis of the performance improvements and penalties predicted by CQIM, the total fuel-related costs were reduced as the percentage of gas co-firing increased. The annual fuel cost component increased as a result of slightly higher natural gas prices and an increase in the net unit heat rate; however, waste disposal, O and M, and replacement energy costs decreased as the percentage of gas co-firing increased. Most of the O and M cost elements (SO{sub 2} emissions and maintenance) and replacement energy cost elements (availability and auxiliary power) decreased as the amount of gas co-firing increased.

  7. Modeling impacts of changes in temperature and water table on C gas fluxes in an Alaskan peatland

    NASA Astrophysics Data System (ADS)

    Deng, Jia; Li, Changsheng; Frolking, Steve

    2015-07-01

    Northern peatlands have accumulated a large amount of organic carbon (C) in their thick peat profile. Climate change and associated variations in soil environments are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is still highly uncertain. Verifying and understanding the influences of changes in environmental factors on C gas fluxes in biogeochemical models are essential for forecasting feedbacks between C gas fluxes and climate change. In this study, we applied a biogeochemical model, DeNitrification-DeComposition (DNDC), to assess impacts of air temperature (TA) and water table (WT) on C gas fluxes in an Alaskan peatland. DNDC was validated against field measurements of net ecosystem exchange of CO2 (NEE) and CH4 fluxes under manipulated surface soil temperature and WT conditions in a moderate rich fen. The validation demonstrates that DNDC was able to capture the observed impacts of the manipulations in soil environments on C gas fluxes. To investigate responses of C gas fluxes to changes in TA and soil water condition, we conducted a series of simulations with varying TA and WT. The results demonstrate that (1) uptake rates of CO2 at the site were reduced by either too colder or warmer temperatures and generally increased with increasing soil moisture; (2) CH4 emissions showed an increasing trend as TA increased or WT rose toward the peat surface; and (3) the site could shift from a net greenhouse gas (GHG) sink into a net GHG source under some warm and/or dry conditions. A sensitivity analysis evaluated the relative importance of TA and WT to C gas fluxes. The results indicate that both TA and WT played important roles in regulating NEE and CH4 emissions and that within the investigated ranges of the variations in TA and WT, changes in WT showed a greater impact than changes in TA on NEE, CH4 fluxes, and net C gas fluxes at the study fen.

  8. Brightness measurement of an electron impact gas ion source for proton beam writing applications

    NASA Astrophysics Data System (ADS)

    Liu, N.; Xu, X.; Pang, R.; Santhana Raman, P.; Khursheed, A.; van Kan, J. A.

    2016-02-01

    We are developing a high brightness nano-aperture electron impact gas ion source, which can create ion beams from a miniature ionization chamber with relatively small virtual source sizes, typically around 100 nm. A prototype source of this kind was designed and successively micro-fabricated using integrated circuit technology. Experiments to measure source brightness were performed inside a field emission scanning electron microscope. The total output current was measured to be between 200 and 300 pA. The highest estimated reduced brightness was found to be comparable to the injecting focused electron beam reduced brightness. This translates into an ion reduced brightness that is significantly better than that of conventional radio frequency ion sources, currently used in single-ended MeV accelerators.

  9. Brightness measurement of an electron impact gas ion source for proton beam writing applications.

    PubMed

    Liu, N; Xu, X; Pang, R; Raman, P Santhana; Khursheed, A; van Kan, J A

    2016-02-01

    We are developing a high brightness nano-aperture electron impact gas ion source, which can create ion beams from a miniature ionization chamber with relatively small virtual source sizes, typically around 100 nm. A prototype source of this kind was designed and successively micro-fabricated using integrated circuit technology. Experiments to measure source brightness were performed inside a field emission scanning electron microscope. The total output current was measured to be between 200 and 300 pA. The highest estimated reduced brightness was found to be comparable to the injecting focused electron beam reduced brightness. This translates into an ion reduced brightness that is significantly better than that of conventional radio frequency ion sources, currently used in single-ended MeV accelerators. PMID:26931964

  10. Impact of exhaust gas recirculation (EGR) on the oxidative reactivity of diesel engine soot

    SciTech Connect

    Al-Qurashi, Khalid; Boehman, Andre L.

    2008-12-15

    This paper expands the consideration of the factors affecting the nanostructure and oxidative reactivity of diesel soot to include the impact of exhaust gas recirculation (EGR). Past work showed that soot derived from oxygenated fuels such as biodiesel carries some surface oxygen functionality and thereby possesses higher reactivity than soot from conventional diesel fuel. In this work, results show that EGR exerts a strong influence on the physical properties of the soot which leads to enhanced oxidation rate. HRTEM images showed a dramatic difference between the burning modes of the soot generated under 0 and 20% EGR. The soot produced under 0% EGR strictly followed an external burning mode with no evidence of internal burning. In contrast, soot generated under 20% EGR exhibited dual burning modes: slow external burning and rapid internal burning. The results demonstrate clearly that highly reactive soot can be achieved by manipulating the physical properties of the soot via EGR. (author)

  11. Impact of offshore gas platforms on the structural and functional biodiversity of nematodes.

    PubMed

    Fraschetti, S; Guarnieri, G; Gambi, C; Bevilacqua, S; Terlizzi, A; Danovaro, R

    2016-04-01

    The Mediterranean Sea hosts hundreds of offshore gas platforms, whose activity represents a potential threat to marine ecosystems. Evidence from several studies indicates that nematodes can be highly sensitive to changes in the environmental quality. Here, we investigated the response of nematode assemblages to the presence of offshore gas platforms (located in the central Mediterranean Sea) in terms of spatial heterogeneity, structural and functional diversity. Since the effect of the investigated offshore platforms on macrofaunal assemblages were previously assessed by Terlizzi et al. (2008), the study provided also the opportunity to compare the response of different benthic compartments to the same impact related to fossil fuel extraction on marine environments. The platforms had a significant impact on nematode assemblages up to 1000 m distance from the structure. The effects were evident in term of: a) more homogeneous spatial distribution of nematode assemblages, b) increased trophic diversity of deposit feeders and c) changes in life strategies with an increase of opportunistic species in sediments closer to the platforms. Such effects seemed to be related to the dimension of the platform structures, rather than to chemical pollution or changes in food availability. These findings suggest that the platforms exert a physical alteration of the surrounding environment that is reflected by altered structural and functional traits of nematode biodiversity. The use of nematodes for monitoring the effects of the platforms only partially matched with the results obtained using macrofauna, providing further insights on potential outcomes on the functional response of marine assemblages to fossil fuel extraction. PMID:26878347

  12. Bird interactions with offshore oil and gas platforms: review of impacts and monitoring techniques.

    PubMed

    Ronconi, Robert A; Allard, Karel A; Taylor, Philip D

    2015-01-01

    Thousands of oil and gas platforms are currently operating in offshore waters globally, and this industry is expected to expand in coming decades. Although the potential environmental impacts of offshore oil and gas activities are widely recognized, there is limited understanding of their impacts on migratory and resident birds. A literature review identified 24 studies and reports of bird-platform interactions, most being qualitative and half having been peer-reviewed. The most frequently observed effect, for seabirds and landbirds, is attraction and sometimes collisions associated with lights and flares; episodic events have caused the deaths of hundreds or even thousands of birds. Though typically unpredictable, anecdotally, it is known that poor weather, such as fog, precipitation and low cloud cover, can exacerbate the effect of nocturnal attraction to lights, especially when coincidental with bird migrations. Other effects include provision of foraging and roosting opportunities, increased exposure to oil and hazardous environments, increased exposure to predators, or repulsion from feeding sites. Current approaches to monitoring birds at offshore platforms have focused on observer-based methods which can offer species-level bird identification, quantify seasonal patterns of relative abundance and distribution, and document avian mortality events and underlying factors. Observer-based monitoring is time-intensive, limited in spatial and temporal coverage, and suffers without clear protocols and when not conducted by trained, independent observers. These difficulties are exacerbated because deleterious bird-platform interaction is episodic and likely requires the coincidence of multiple factors (e.g., darkness, cloud, fog, rain conditions, occurrence of birds in vicinity). Collectively, these considerations suggest a need to implement supplemental systems for monitoring bird activities around offshore platforms. Instrument-based approaches, such as radar

  13. Assessment of the impact of TOA partitioning on DWPF off-gas flammability

    SciTech Connect

    Daniel, W. E.

    2013-06-01

    An assessment has been made to evaluate the impact on the DWPF melter off-gas flammability of increasing the amount of TOA in the current solvent used in the Modular Caustic-Side Solvent Extraction Process Unit (MCU) process. The results of this study showed that the concentrations of nonvolatile carbon of the current solvent limit (150 ppm) in the Slurry Mix Evaporator (SME) product would be about 7% higher and the nonvolatile hydrogen would be 2% higher than the actual current solvent (126 ppm) with an addition of up to 3 ppm of TOA when the concentration of Isopar L in the effluent transfer is controlled below 87 ppm and the volume of MCU effluent transfer to DWPF is limited to 15,000 gallons per Sludge Receipt and Adjustment Tank (SRAT)/SME cycle. Therefore, the DWPF melter off-gas flammability assessment is conservative for up to an additional 3 ppm of TOA in the effluent based on these assumptions. This report documents the calculations performed to reach this conclusion.

  14. The impact of municipal solid waste management on greenhouse gas emissions in the United States.

    PubMed

    Weitz, Keith A; Thorneloe, Susan A; Nishtala, Subba R; Yarkosky, Sherry; Zannes, Maria

    2002-09-01

    Technological advancements, environmental regulations, and emphasis on resource conservation and recovery have greatly reduced the environmental impacts of municipal solid waste (MSW) management, including emissions of greenhouse gases (GHGs). This study was conducted using a life-cycle methodology to track changes in GHG emissions during the past 25 years from the management of MSW in the United States. For the baseline year of 1974, MSW management consisted of limited recycling, combustion without energy recovery, and landfilling without gas collection or control. This was compared with data for 1980, 1990, and 1997, accounting for changes in MSW quantity, composition, management practices, and technology. Over time, the United States has moved toward increased recycling, composting, combustion (with energy recovery) and landfilling with gas recovery, control, and utilization. These changes were accounted for with historical data on MSW composition, quantities, management practices, and technological changes. Included in the analysis were the benefits of materials recycling and energy recovery to the extent that these displace virgin raw materials and fossil fuel electricity production, respectively. Carbon sinks associated with MSW management also were addressed. The results indicate that the MSW management actions taken by U.S. communities have significantly reduced potential GHG emissions despite an almost 2-fold increase in waste generation. GHG emissions from MSW management were estimated to be 36 million metric tons carbon equivalents (MMTCE) in 1974 and 8 MMTCE in 1997. If MSW were being managed today as it was in 1974, GHG emissions would be approximately 60 MMTCE. PMID:12269661

  15. Impact of Pilot Light Modeling on the Predicted Annual Performance of Residential Gas Water Heaters: Preprint

    SciTech Connect

    Maguire, J.; Burch, J.

    2013-08-01

    Modeling residential water heaters with dynamic simulation models can provide accurate estimates of their annual energy consumption, if the units? characteristics and use conditions are known. Most gas storage water heaters (GSWHs) include a standing pilot light. It is generally assumed that the pilot light energy will help make up standby losses and have no impact on the predicted annual energy consumption. However, that is not always the case. The gas input rate and conversion efficiency of a pilot light for a GSWH were determined from laboratory data. The data were used in simulations of a typical GSWH with and without a pilot light, for two cases: 1) the GSWH is used alone; and 2) the GSWH is the second tank in a solar water heating (SWH) system. The sensitivity of wasted pilot light energy to annual hot water use, climate, and installation location was examined. The GSWH used alone in unconditioned space in a hot climate had a slight increase in energy consumption. The GSWH with a pilot light used as a backup to an SWH used up to 80% more auxiliary energy than one without in hot, sunny locations, from increased tank losses.

  16. Aluminum/ammonia heat pipe gas generation and long term system impact for the Space Telescope's Wide Field Planetary Camera

    NASA Technical Reports Server (NTRS)

    Jones, J. A.

    1983-01-01

    In the Space Telescope's Wide Field Planetary Camera (WFPC) project, eight heat pipes (HPs) are used to remove heat from the camera's inner electronic sensors to the spacecraft's outer, cold radiator surface. For proper device functioning and maximization of the signal-to-noise ratios, the Charge Coupled Devices (CCD's) must be maintained at -95 C or lower. Thermoelectric coolers (TEC's) cool the CCD's, and heat pipes deliver each TEC's nominal six to eight watts of heat to the space radiator, which reaches an equilibrium temperature between -15 C to -70 C. An initial problem was related to the difficulty to produce gas-free aluminum/ammonia heat pipes. An investigation was, therefore, conducted to determine the cause of the gas generation and the impact of this gas on CCD cooling. In order to study the effect of gas slugs in the WFPC system, a separate HP was made. Attention is given to fabrication, testing, and heat pipe gas generation chemistry studies.

  17. Decreasing Impact Tilt on a High Performance Two-Stage Gas Gun

    NASA Astrophysics Data System (ADS)

    Byers, M. E.; Rigg, P. A.; Esparza, J. S.

    2007-06-01

    There are four high-performance two-stage light gas guns in operation in the DOE complex. All four guns are similar in performance and diagnostics capabilities. Projectile velocity on these guns has typically been measured using a combination of magnetic coils and two frames of flash radiography. This requires that the projectile be in 'free flight' for a long distance (18 to 25 inches typical) in order to capture the projectile in flight. This leads to typical projectile tilt at impact in excess of 10 mrad. Recently, we have replaced the coil/x-ray system on the LANL high performance two-stage gun with Photonic Doppler Velocimetry (PDV) to obtain high accuracy (0.1%) projectile velocity measurements. This allows us to move the target very close to the end of the barrel to potentially decrease the impact tilt significantly. We will present the results of this study and compare them to the performance of the gun when the free flight section was present.

  18. Sulfur Isotopes in Gas-rich Impact-Melt Glasses in Shergottites

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Hoppe, P.; Sutton, S. R.; Nyquist, Laurence E.; Huth, J.

    2010-01-01

    Large impact melt glasses in some shergottites contain huge amounts of Martian atmospheric gases and they are known as gas-rich impact-melt (GRIM) glasses. By studying the neutron-induced isotopic deficits and excesses in Sm-149 and Sm-150 isotopes resulting from Sm-149 (n,gamma) 150Sm reaction and 80Kr excesses produced by Br-79 (n,gamma) Kr-80 reaction in the GRIM glasses using mass-spectrometric techniques, it was shown that these glasses in shergottites EET79001 and Shergotty contain regolith materials irradiated by a thermal neutron fluence of approx.10(exp 15) n/sq cm near Martian surface. Also, it was shown that these glasses contain varying amounts of sulfates and sulfides based on the release patterns of SO2 (sulfate) and H2S (sulfide) using stepwise-heating mass-spectrometric techniques. Furthermore, EMPA and FE-SEM studies in basaltic-shergottite GRIM glasses EET79001, LithB (,507& ,69), Shergotty (DBS I &II), Zagami (,992 & ,994) showed positive correlation between FeO and "SO3" (sulfide + sulfate), whereas those belonging to olivine-phyric shergottites EET79001, LithA (,506, & ,77) showed positive correlation between CaO/Al2O3 and "SO3".

  19. Stealing the Gas: Giant Impacts and the Large Diversity in Exoplanet Densities

    NASA Astrophysics Data System (ADS)

    Inamdar, Niraj K.; Schlichting, Hilke E.

    2016-02-01

    Although current sensitivity limits are such that true solar system analogs remain challenging to detect, numerous planetary systems have been discovered that are very different from our own solar system. The majority of systems harbor a new class of planets, bodies that are typically several times more massive than the Earth but orbit their host stars well inside the orbit of Mercury. These planets frequently show evidence for large hydrogen and helium envelopes containing several percent of the planet’s mass and display a large diversity in mean densities. Here we show that this wide range can be achieved by one or two late giant impacts, which are frequently needed to achieve long-term orbital stability in multiple planet systems once the gas disk has disappeared. We demonstrate using hydrodynamical simulations that a single collision between similarly sized exoplanets can easily reduce the envelope-to-core-mass ratio by a factor of two and show that this leads to a corresponding increase in the observed mean density by factors of two to three. In addition, we investigate how envelope mass loss depends on envelope mass, planet radius, semimajor axis, and the mass distribution inside the envelope. We propose that a small number of giant impacts may be responsible for the large observed spread in mean densities, especially for multiple-planet systems that contain planets with very different densities and have not been significantly sculpted by photoevaporation.

  20. 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.

  1. Energy/economic model analysis. Macroeconomic impacts of research and development in gas supply and end use technologies

    NASA Astrophysics Data System (ADS)

    Goettle, R. J., IV; Hudson, E. A.

    1980-06-01

    The Gas Research Institute (GRI) needs to consider the economic impact of the various technologies whose research and development is supported by GRI funding. Three energy-economic models are useful for such a technology assessment. These models are: Energy Economic Modeling System, Energy Policy Model, and Time Stepped Energy System Optimization/Long Term Inter-Industry Transaction Model. These three models were used to help in the economic impact evaluation of various GRI research and development programs.

  2. Enhanced formation of disinfection byproducts in shale gas wastewater-impacted drinking water supplies.

    PubMed

    Parker, Kimberly M; Zeng, Teng; Harkness, Jennifer; Vengosh, Avner; Mitch, William A

    2014-10-01

    The disposal and leaks of hydraulic fracturing wastewater (HFW) to the environment pose human health risks. Since HFW is typically characterized by elevated salinity, concerns have been raised whether the high bromide and iodide in HFW may promote the formation of disinfection byproducts (DBPs) and alter their speciation to more toxic brominated and iodinated analogues. This study evaluated the minimum volume percentage of two Marcellus Shale and one Fayetteville Shale HFWs diluted by fresh water collected from the Ohio and Allegheny Rivers that would generate and/or alter the formation and speciation of DBPs following chlorination, chloramination, and ozonation treatments of the blended solutions. During chlorination, dilutions as low as 0.01% HFW altered the speciation toward formation of brominated and iodinated trihalomethanes (THMs) and brominated haloacetonitriles (HANs), and dilutions as low as 0.03% increased the overall formation of both compound classes. The increase in bromide concentration associated with 0.01-0.03% contribution of Marcellus HFW (a range of 70-200 μg/L for HFW with bromide = 600 mg/L) mimics the increased bromide levels observed in western Pennsylvanian surface waters following the Marcellus Shale gas production boom. Chloramination reduced HAN and regulated THM formation; however, iodinated trihalomethane formation was observed at lower pH. For municipal wastewater-impacted river water, the presence of 0.1% HFW increased the formation of N-nitrosodimethylamine (NDMA) during chloramination, particularly for the high iodide (54 ppm) Fayetteville Shale HFW. Finally, ozonation of 0.01-0.03% HFW-impacted river water resulted in significant increases in bromate formation. The results suggest that total elimination of HFW discharge and/or installation of halide-specific removal techniques in centralized brine treatment facilities may be a better strategy to mitigate impacts on downstream drinking water treatment plants than altering

  3. Impact of emissions from natural gas production facilities on ambient air quality in the Barnett Shale area: a pilot study.

    PubMed

    Zielinska, Barbara; Campbell, Dave; Samburova, Vera

    2014-12-01

    Rapid and extensive development of shale gas resources in the Barnett Shale region of Texas in recent years has created concerns about potential environmental impacts on water and air quality. The purpose of this study was to provide a better understanding of the potential contributions of emissions from gas production operations to population exposure to air toxics in the Barnett Shale region. This goal was approached using a combination of chemical characterization of the volatile organic compound (VOC) emissions from active wells, saturation monitoring for gaseous and particulate pollutants in a residential community located near active gas/oil extraction and processing facilities, source apportionment of VOCs measured in the community using the Chemical Mass Balance (CMB) receptor model, and direct measurements of the pollutant gradient downwind of a gas well with high VOC emissions. Overall, the study results indicate that air quality impacts due to individual gas wells and compressor stations are not likely to be discernible beyond a distance of approximately 100 m in the downwind direction. However, source apportionment results indicate a significant contribution to regional VOCs from gas production sources, particularly for lower-molecular-weight alkanes (< C6). Although measured ambient VOC concentrations were well below health-based safe exposure levels, the existence of urban-level mean concentrations of benzene and other mobile source air toxics combined with soot to total carbon ratios that were high for an area with little residential or commercial development may be indicative of the impact of increased heavy-duty vehicle traffic related to gas production. Implications: Rapid and extensive development of shale gas resources in recent years has created concerns about potential environmental impacts on water and air quality. This study focused on directly measuring the ambient air pollutant levels occurring at residential properties located near

  4. The impact of meteorological forcings on gas phase air pollutants over Europe

    NASA Astrophysics Data System (ADS)

    Watson, Laura; Lacressonnière, Gwendoline; Gauss, Michael; Engardt, Magnuz; Andersson, Camilla; Josse, Béatrice; Marécal, Virginie; Nyiri, Agnes; Sobolowski, Stefan; Siour, Guillaume; Vautard, Robert

    2015-10-01

    The impact of meteorological forcings on gas phase air pollutants (ozone and nitrogen dioxide) over Europe was studied using four offline chemistry transport models (CTMs) as part of the IMPACT2C project. This study uses long (20- and 30-year) simulations to evaluate the present-day performance of the CTMs, which is a necessary first step before undertaking any analysis of future air quality impacts. Two sets of meteorological forcings were used for each model: reanalysis of past observation data (ERA-Interim) and Global Climate Model (GCM) output. The results for the simulations forced by reanalysis data were assessed in relation to AirBase v7 measurement data, and it was determined that all four models slightly overpredict annual O3 values (mean biases range between 0.7 and 6.6 ppb) and three out of the four models underpredict observed annual NO2 (mean biases range between -3.1 and -5.2 ppb). The simulations forced by climate models result in spatially averaged monthly concentrations of O3 that are generally between 0 and 5 ppb higher than the values obtained from simulations forced by reanalysis data; therefore it was concluded that the use of climate models introduces an additional bias to the results, but this bias tends not to be significant in the majority of cases. The bias in O3 results appears to be correlated mainly to differences in temperature and boundary layer height between the two types of simulations, whereas the less significant bias in NO2 is negatively correlated to temperature and boundary layer height. It is also clear that the selection of chemical boundary conditions is an important factor in determining the variability of O3 model results. These results will be used as a baseline for the interpretation of future work, which will include an analysis of future climate scenarios upon European air quality.

  5. Potential of Best Practice to Reduce Impacts from Oil and Gas Projects in the Amazon

    PubMed Central

    Finer, Matt; Jenkins, Clinton N.; Powers, Bill

    2013-01-01

    The western Amazon continues to be an active and controversial zone of hydrocarbon exploration and production. We argue for the urgent need to implement best practices to reduce the negative environmental and social impacts associated with the sector. Here, we present a three-part study aimed at resolving the major obstacles impeding the advancement of best practice in the region. Our focus is on Loreto, Peru, one of the largest and most dynamic hydrocarbon zones in the Amazon. First, we develop a set of specific best practice guidelines to address the lack of clarity surrounding the issue. These guidelines incorporate both engineering-based criteria and key ecological and social factors. Second, we provide a detailed analysis of existing and planned hydrocarbon activities and infrastructure, overcoming the lack of information that typically hampers large-scale impact analysis. Third, we evaluate the planned activities and infrastructure with respect to the best practice guidelines. We show that Loreto is an extremely active hydrocarbon front, highlighted by a number of recent oil and gas discoveries and a sustained government push for increased exploration. Our analyses reveal that the use of technical best practice could minimize future impacts by greatly reducing the amount of required infrastructure such as drilling platforms and access roads. We also document a critical need to consider more fully the ecological and social factors, as the vast majority of planned infrastructure overlaps sensitive areas such as protected areas, indigenous territories, and key ecosystems and watersheds. Lastly, our cost analysis indicates that following best practice does not impose substantially greater costs than conventional practice, and may in fact reduce overall costs. Barriers to the widespread implementation of best practice in the Amazon clearly exist, but our findings show that there can be great benefits to its implementation. PMID:23650541

  6. Potential of best practice to reduce impacts from oil and gas projects in the Amazon.

    PubMed

    Finer, Matt; Jenkins, Clinton N; Powers, Bill

    2013-01-01

    The western Amazon continues to be an active and controversial zone of hydrocarbon exploration and production. We argue for the urgent need to implement best practices to reduce the negative environmental and social impacts associated with the sector. Here, we present a three-part study aimed at resolving the major obstacles impeding the advancement of best practice in the region. Our focus is on Loreto, Peru, one of the largest and most dynamic hydrocarbon zones in the Amazon. First, we develop a set of specific best practice guidelines to address the lack of clarity surrounding the issue. These guidelines incorporate both engineering-based criteria and key ecological and social factors. Second, we provide a detailed analysis of existing and planned hydrocarbon activities and infrastructure, overcoming the lack of information that typically hampers large-scale impact analysis. Third, we evaluate the planned activities and infrastructure with respect to the best practice guidelines. We show that Loreto is an extremely active hydrocarbon front, highlighted by a number of recent oil and gas discoveries and a sustained government push for increased exploration. Our analyses reveal that the use of technical best practice could minimize future impacts by greatly reducing the amount of required infrastructure such as drilling platforms and access roads. We also document a critical need to consider more fully the ecological and social factors, as the vast majority of planned infrastructure overlaps sensitive areas such as protected areas, indigenous territories, and key ecosystems and watersheds. Lastly, our cost analysis indicates that following best practice does not impose substantially greater costs than conventional practice, and may in fact reduce overall costs. Barriers to the widespread implementation of best practice in the Amazon clearly exist, but our findings show that there can be great benefits to its implementation. PMID:23650541

  7. Global change and the mulga woodlands of southwest Queensland: greenhouse gas emissions, impacts, and adaptation.

    PubMed

    Howden, S M; Moore, J L; McKeon, G M; Carter, J O

    2001-09-01

    The possibility of trading greenhouse gas emission permits as a result of the Kyoto Protocol has spurred interest in developing land-based sinks for greenhouse gases. Extensive grazing lands that have the potential to develop substantial woody biomass are one obvious candidate for such activities. However, such activities need to consider the possible impacts on existing grazing and the possible impacts of continuing CO2 buildup in the atmosphere and resultant climate change. We used simulation models to investigate these issues in the mulga (Acacia aneura) woodlands of southwest Queensland. The simulation results suggest that this system can be managed to act as either a net source or a net sink of greenhouse gases under current climate and CO2 and under a range of global change scenarios. The key component in determining source or sink status is the management of the woody mulga. The most effective means of permanently increasing carbon stores and hence reducing net emissions is to exclude both burning and grazing. There are combinations of management regimes, such as excluding fire with light grazing, which, on average, allows productive grazing but transient carbon storage. The effects of increased CO2 on ecosystem carbon stores were unexpected. Carbon stores increased (7-17%) with doubling of CO2 only in those simulations where burning did not occur, but decreased when burnt. This occurred because the substantial increases in grass growth with doubling of CO2 (34-56%) enabled more fires, killing off the establishing cohorts needed to ensure continued carbon accumulation. On average, the doubling of atmospheric CO2 concentration increased grass growth by 44%, which is identical with mean literature values, suggesting that this result may be applicable in other ecosystems where fire has a similar function. A sensitivity analysis of the CO2 response of mulga showed only minor impacts. We discuss additional uncertainties and shortcomings. PMID:11697664

  8. Physiological impact of patent foramen ovale on pulmonary gas exchange, ventilatory acclimatization, and thermoregulation.

    PubMed

    Lovering, Andrew T; Elliott, Jonathan E; Davis, James T

    2016-08-01

    The foramen ovale, which is part of the normal fetal cardiopulmonary circulation, fails to close after birth in ∼35% of the population and represents a potential source of right-to-left shunt. Despite the prevalence of patent foramen ovale (PFO) in the general population, cardiopulmonary, exercise, thermoregulatory, and altitude physiologists may have underestimated the potential effect of this shunted blood flow on normal physiological processes in otherwise healthy humans. Because this shunted blood bypasses the respiratory system, it would not participate in either gas exchange or respiratory system cooling and may have impacts on other physiological processes that remain undetermined. The consequences of this shunted blood flow in PFO-positive (PFO+) subjects can potentially have a significant, and negative, impact on the alveolar-to-arterial oxygen difference (AaDO2), ventilatory acclimatization to high altitude and respiratory system cooling with PFO+ subjects having a wider AaDO2 at rest, during exercise after acclimatization, blunted ventilatory acclimatization, and a higher core body temperature (∼0.4(°)C) at rest and during exercise. There is also an association of PFO with high-altitude pulmonary edema and acute mountain sickness. These effects on physiological processes are likely dependent on both the presence and size of the PFO, with small PFOs not likely to have significant/measureable effects. The PFO can be an important determinant of normal physiological processes and should be considered a potential confounder to the interpretation of former and future data, particularly in small data sets where a significant number of PFO+ subjects could be present and significantly impact the measured outcomes. PMID:27418686

  9. Including impacts of particulate emissions on marine ecosystems in life cycle assessment: the case of offshore oil and gas production.

    PubMed

    Veltman, Karin; Huijbregts, Mark A J; Rye, Henrik; Hertwich, Edgar G

    2011-10-01

    Life cycle assessment is increasingly used to assess the environmental performance of fossil energy systems. Two of the dominant emissions of offshore oil and gas production to the marine environment are the discharge of produced water and drilling waste. Although environmental impacts of produced water are predominantly due to chemical stressors, a major concern regarding drilling waste discharge is the potential physical impact due to particles. At present, impact indicators for particulate emissions are not yet available in life cycle assessment. Here, we develop characterization factors for 2 distinct impacts of particulate emissions: an increased turbidity zone in the water column and physical burial of benthic communities. The characterization factor for turbidity is developed analogous to characterization factors for toxic impacts, and ranges from 1.4 PAF (potentially affected fraction) · m(3) /d/kg(p) (kilogram particulate) to 7.0 x 10³ [corrected] for drilling mud particles discharged from the rig. The characterization factor for burial describes the volume of sediment that is impacted by particle deposition on the seafloor and equals 2.0 × 10(-1) PAF · m(3) /d/kg(p) for cutting particles. This characterization factor is quantified on the basis of initial deposition layer characteristics, such as height and surface area, the initial benthic response, and the recovery rate. We assessed the relevance of including particulate emissions in an impact assessment of offshore oil and gas production. Accordingly, the total impact on the water column and on the sediment was quantified based on emission data of produced water and drilling waste for all oil and gas fields on the Norwegian continental shelf in 2008. Our results show that cutting particles contribute substantially to the total impact of offshore oil and gas production on marine sediments, with a relative contribution of 55% and 31% on the regional and global scale, respectively. In contrast, the

  10. Impact of wood pruning to greenhouse gas emissions in three orchards and a vineyard

    NASA Astrophysics Data System (ADS)

    Germer, Sonja; Schleicher, Sarah; Bischoff, Wolf-Anno; Gomez Palermo, Maider; Kern, Jürgen

    2015-04-01

    Pruning of orchards and vineyards is usually burned or left on the soil for nutrient and organic carbon recycling. Recently the interest rose to extract pruning for energetic use. Very few studies exist that analyzed the effects of pruning removal on soil physical and chemical characteristics. This is linked to the fact that changes are expected rather in the long term, but project funding is typically restricted to 2 or 3 years. Some soil characteristics, however, as organic carbon content and greenhouse gas emissions might also change on the short term as our literature review reveals. The main objective of this research is to determine if pruning extraction from orchards and vineyards impact greenhouse gas emissions (N2O, CH4, and CO2) from soil to the atmosphere, change soil nitrogen and carbon content or effect nitrogen leaching. Results from our study and from the literature will be compiled to formulate best management practices for sustainable pruning utilization from orchards and vineyards. Here we compare four different study sites in a block design over two rows each with two parcels where we extracted pruning and two parcels where pruning was chipped and left on the soil (n=4). Comparisons were made for initial soil chemistry and greenhouse gas emissions in a cherry orchard without irrigation in Germany, a vineyard without irrigation in France, an almond orchard with drip irrigation in Spain and a peach orchard with flood irrigation in Spain. Soil greenhouse gas emissions depend on soil chemistry and soil moisture. These characteristics can be expected to vary between the tree rows and inter-rows of orchards. Therefore we took soil samples from row and inter-row positions of each study site and analyzed them for chemical parameters (pH, total C, N, S, and H, and available PO4, NH4, NO3, K, Mg, Ca). Additionally soil moisture and temperature data have been recorded for tree rows and inter-rows in the cherry orchard and the vineyard. Gas samples were

  11. Regional ozone impacts of increased natural gas use in the Texas power sector and development in the Eagle Ford shale.

    PubMed

    Pacsi, Adam P; Kimura, Yosuke; McGaughey, Gary; McDonald-Buller, Elena C; Allen, David T

    2015-03-17

    The combined emissions and air quality impacts of electricity generation in the Texas grid and natural gas production in the Eagle Ford shale were estimated at various natural gas price points for the power sector. The increased use of natural gas in the power sector, in place of coal-fired power generation, drove reductions in average daily maximum 8 h ozone concentration of 0.6-1.3 ppb in northeastern Texas for a high ozone episode used in air quality planning. The associated increase in Eagle Ford upstream oil and gas production nitrogen oxide (NOx) emissions caused an estimated local increase, in south Texas, of 0.3-0.7 ppb in the same ozone metric. In addition, the potential ozone impacts of Eagle Ford emissions on nearby urban areas were estimated. On the basis of evidence from this work and a previous study on the Barnett shale, the combined ozone impact of increased natural gas development and use in the power sector is likely to vary regionally and must be analyzed on a case by case basis. PMID:25723953

  12. Greenhouse Gas and Particulate Emissions and Impacts from Cooking Technologies in Africa

    NASA Astrophysics Data System (ADS)

    Kammen, D. M.; Bailis, R.; Kituyi, E.; Ezzati, M.

    2003-12-01

    In much of Africa, the largest fraction of energy consumption occurs within the residential sector and is derived primarily from woodfuels burned in simple stoves with poor combustion characteristics. Many of the products of incomplete combustion (PICs) are damaging to human health, particularly when they are concentrated in poorly ventilated indoor environments. Incomplete combustion also has potentially harmful impacts on the climate. Prevalent PICs include methane, a potent greenhouse gas (GHG) that is among the pollutants subject to controls under the Kyoto Protocol as well as carbon monoxide (CO), non-methane hydrocarbons (NMHCs) and particulate matter (PM), which can all have an effect on climate, but are not subject to controls under Kyoto. In addition, when woodfuels are used at a rate that reduces standing stocks of trees over the medium or long term, the CO2 released by combustion also has an impact. The choice of stove and fuel technology can have a significant impact on the emission of GHGs as well as on human exposure to health damaging pollutants. In this paper we analyze the emissions of different household energy technologies on a life-cycle basis. We use emission factors to estimate the emissions associated with production, distribution and end-use of common household fuels and assess the likely impacts of these emissions on public health and the global environment. We focus largely on charcoal, a popular fuel in many sub-Saharan African countries. Charcoal is produced by heating wood in the absence of sufficient air for complete combustion to occur. This process removes moisture and most of the volatile compounds. The compounds driven off in the process consist of condensable tars as well as many gaseous hydrocarbons, including ~40 g CH4 per kg of charcoal produced. Combining upstream and end-use emissions, every meal cooked with charcoal has 2-10 times the global warming effect of cooking the same meal with firewood and 5-12 times the effect of

  13. 77 FR 42761 - Final Environmental Impact Statement for the Oil and Gas Management Plan at Big South Fork...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Park Service Final Environmental Impact Statement for the Oil and Gas Management Plan at Big South... Blount, Big South Fork National River ] and Recreation Area and Obed Wild and Scenic River Chief...

  14. 76 FR 35009 - Draft Oil and Gas Management Plan/Environmental Impact Statement for Big South Fork National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-15

    ... National Park Service Draft Oil and Gas Management Plan/Environmental Impact Statement for Big South Fork... Big South Fork National River and Recreation Area and Obed Wild and Scenic River. SUMMARY: Pursuant to.../DEIS) for the proposed Big South Fork National River and Recreation Area (BISO) and Obed Wild...

  15. A Framework to Predict the Impacts of Shale Gas Infrastructures on the Forest Fragmentation of an Agroforest Region

    NASA Astrophysics Data System (ADS)

    Racicot, Alexandre; Babin-Roussel, Véronique; Dauphinais, Jean-François; Joly, Jean-Sébastien; Noël, Pascal; Lavoie, Claude

    2014-05-01

    We propose a framework to facilitate the evaluation of the impacts of shale gas infrastructures (well pads, roads, and pipelines) on land cover features, especially with regards to forest fragmentation. We used a geographic information system and realistic development scenarios largely inspired by the PA (United States) experience, but adapted to a region of QC (Canada) with an already fragmented forest cover and a high gas potential. The scenario with the greatest impact results from development limited by regulatory constraints only, with no access to private roads for connecting well pads to the public road network. The scenario with the lowest impact additionally integrates ecological constraints (deer yards, maple woodlots, and wetlands). Overall the differences between these two scenarios are relatively minor, with <1 % of the forest cover lost in each case. However, large areas of core forests would be lost in both scenarios and the number of forest patches would increase by 13-21 % due to fragmentation. The pipeline network would have a much greater footprint on the land cover than access roads. Using data acquired since the beginning of the shale gas industry, we show that it is possible, within a reasonable time frame, to produce a robust assessment of the impacts of shale gas extraction. The framework we propose could easily be applied to other contexts or jurisdictions.

  16. A framework to predict the impacts of shale gas infrastructures on the forest fragmentation of an agroforest region.

    PubMed

    Racicot, Alexandre; Babin-Roussel, Véronique; Dauphinais, Jean-François; Joly, Jean-Sébastien; Noël, Pascal; Lavoie, Claude

    2014-05-01

    We propose a framework to facilitate the evaluation of the impacts of shale gas infrastructures (well pads, roads, and pipelines) on land cover features, especially with regards to forest fragmentation. We used a geographic information system and realistic development scenarios largely inspired by the PA (United States) experience, but adapted to a region of QC (Canada) with an already fragmented forest cover and a high gas potential. The scenario with the greatest impact results from development limited by regulatory constraints only, with no access to private roads for connecting well pads to the public road network. The scenario with the lowest impact additionally integrates ecological constraints (deer yards, maple woodlots, and wetlands). Overall the differences between these two scenarios are relatively minor, with <1 % of the forest cover lost in each case. However, large areas of core forests would be lost in both scenarios and the number of forest patches would increase by 13-21 % due to fragmentation. The pipeline network would have a much greater footprint on the land cover than access roads. Using data acquired since the beginning of the shale gas industry, we show that it is possible, within a reasonable time frame, to produce a robust assessment of the impacts of shale gas extraction. The framework we propose could easily be applied to other contexts or jurisdictions. PMID:24554146

  17. NONWATER QUALITY IMPACTS OF CLOSED-CYCLE COOLING SYSTEMS AND THE INTERACTION OF STACK GAS AND COOLING TOWER PLUMES

    EPA Science Inventory

    The report gives results of a literature survey of the nonwater quality impacts of closed-cycle cooling systems. Following discussions of cooling tower and stack gas plumes, interactions of these plumes are considered. For cooling tower plumes, plume types, behavior, salt drift g...

  18. 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

  19. Mineralogical and Noble Gas Evidence for an ET Impact at the Younger Dryas

    NASA Astrophysics Data System (ADS)

    Darrah, T. H.; Poreda, R. J.; Kennett, J. P.; Becker, L.; West, A.; Kennett, D. J.; Elrandson, J. M.

    2007-05-01

    We report mineralogical and noble gas evidence for an ET impact associated with the Younger Dryas (YD) event and the mass extinction of various megafauna throughout the Americas approximately 12,900 years ago. We examined numerous well established, 14C dated Clovis sites across the US including detailed sediment profile analyses at Daisy Cave, CA (DC), Murray Springs, AZ (MS), Topper, SC, and Blackwater Draw, NM (BWD). He, Ne, and Ar analysis of magnetic separates, bulk sediments, HF-acid treated residue, and fullerenes coupled with a detailed mineralogical and compositional analysis of magnetic separates by SEM suggest a marked increase in the accretion of extraterrestrial debris in sediments at the YD boundary layer. A preliminary characterization of the magnetic separates consistently observed across numerous sites indicates an extremely high abundance of relatively unoxidized, trace metal rich metallic grains with extremely unusual compositions (e.g. Pt (5-98%), Sn (25-28%) , Ni (1-11%), and Cu (12-90%). These compositions are not easily explained by ordinary terrestrial processes. A few examples include the YD layer at DC which contains numerous metallic grains including Fe-Ni, Cu-Ni, Fe-Sn-Ni, and Pt grains. Metallic iron grains are observed at BWD and Topper, while the Topper site also contains iron spherules, Fe-Ni metallic grains, and Fe-Ni oxides. At this point there is no evidence for a significant concentration of iron spherules, Fe-Ni oxides nor unusual metallic grains away from the proposed impact layer. The noble gas composition and isotopic ratios of fullerenes located at the YD layers contain trapped He with ET isotopic signatures (0.3-3.5 ncc/g 3He and 3He/4He 30- 220 Ra) while Argon ratios (40Ar/36Ar= 230-255) reflect a mixture of planetary and air components. Bulk sediments were treated with HF acid to remove silicates, leaving a carbonaceous residue. Acid treated residues from two boundary layers contained up to 5 ncc/g 3He and 3He/4He from 15

  20. Mineralogical and Noble Gas Evidence for an ET Impact at the Younger Dryas

    NASA Astrophysics Data System (ADS)

    Darrah, T. H.; Poreda, R. J.; Kennett, J. P.; Becker, L.; West, A.; Kennett, D. J.; Erlandson, J. M.

    2006-12-01

    We report mineralogical and noble gas evidence for an ET impact associated with the Younger Dryas (YD) event and the mass extinction of various megafauna throughout the Americas approximately 12,900 years ago. We examined numerous well established, 14C dated Clovis sites across the US including detailed sediment profile analyses at Daisy Cave, CA (DC), Murray Springs, AZ (MS), Topper, SC, and Blackwater Draw, NM (BWD). He, Ne, and Ar analysis of magnetic separates, bulk sediments, HF-acid treated residue, and fullerenes coupled with a detailed mineralogical and compositional analysis of magnetic separates by SEM suggest a marked increase in the accretion of extraterrestrial debris in sediments at the YD boundary layer. A preliminary characterization of the magnetic separates consistently observed across numerous sites indicates an extremely high abundance of relatively unoxidized, trace metal rich metallic grains with extremely unusual compositions (e.g. Pt (5-98%), Sn (25-28%) , Ni (1-11%), and Cu (12-90%). These compositions are not easily explained by ordinary terrestrial processes. A few examples include the YD layer at DC which contains numerous metallic grains including Fe-Ni, Cu-Ni, Fe-Sn-Ni, and Pt grains. Metallic iron grains are observed at BWD and Topper, while the Topper site also contains iron spherules, Fe-Ni metallic grains, and Fe-Ni oxides. At this point there is no evidence for a significant concentration of iron spherules, Fe-Ni oxides nor unusual metallic grains away from the proposed impact layer. The noble gas composition and isotopic ratios of fullerenes located at the YD layers contain trapped He with ET isotopic signatures (0.3-3.5 ncc/g 3He and 3He/4He 30- 220 Ra) while Argon ratios (40Ar/^{36}Ar= 230-255) reflect a mixture of planetary and air components. Bulk sediments were treated with HF acid to remove silicates, leaving a carbonaceous residue. Acid treated residues from two boundary layers contained up to 5 ncc/g 3He and 3He/4He from

  1. Analyzing the Impact of Residential Building Attributes, Demographic and Behavioral Factors on Natural Gas Usage

    SciTech Connect

    Livingston, Olga V.; Cort, Katherine A.

    2011-03-03

    study attempts to bridge that gap by analyzing behavioral data and investigate the applicability of additive nonparametric regression to this task. This study evaluates the impact of 31 regressors on residential natural gas usage. The regressors include weather, economic variables, demographic and behavioral characteristics, and building attributes related to energy use. In general, most of the regression results were in line with previous engineering and economic studies in this area. There were, however, some counterintuitive results, particularly with regard to thermostat controls and behaviors. There are a number of possible reasons for these counterintuitive results including the inability to control for regional climate variability due to the data sanitization (to prevent identification of respondents), inaccurate data caused by to self-reporting, and the fact that not all relevant behavioral variables were included in the data set, so we were not able to control for them in the study. The results of this analysis could be used as an in-sample prediction for approximating energy demand of a residential building whose characteristics are described by the regressors in this analysis, but a certain combination of their particular values does not exist in the real world. In addition, this study has potential applications for benefit-cost analysis of residential upgrades and retrofits under a fixed budget, because the results of this study contain information on how natural gas consumption might change once a particular characteristic or attribute is altered. Finally, the results of this study can help establish a relationship between natural gas consumption and changes in behavior of occupants.

  2. Volcanic gas emissions and their impact on ambient air character at Kilauea Volcano, Hawaii

    SciTech Connect

    Sutton, A.J.; Elias, T.; Navarrete, R.

    1994-12-31

    Gas emissions from Kilauea occur from the summit caldera, along the middle East Rift Zone (ERZ), and where lava enters the ocean. We estimate that the current ERZ eruption of Kilauea releases between 400 metric tonnes of SO{sub 2} per day, during eruptive pauses, to as much as 1850 metric tonnes per day during actively erupting periods, along with lesser amounts of other chemically and radiatively active species including H{sub 2}S, HCl and HF. In order to characterize gas emissions from Kilauea in a meaningful way for assessing environmental impact, we made a series of replicate grab-sample measurements of ambient air and precipitation at the summit of Kilauea, along its ERZ, and at coastal sites where lava enters the ocean. The grab-sampling data combined with SO{sub 2} emission rates, and continuous air quality and meteorological monitoring at the summit of Kilauea show that the effects of these emissions on ambient air character are a complex function of chemical reactivity, source geometry and effusivity, and local meteorology. Prevailing tradewinds typically carry the gases and aerosols released to the southwest, where they are further distributed by the regional wind regime. Episodes of kona, or low speed variable winds sometimes disrupt this pattern, however, and allow the gases and their oxidation products to collect at the summit and eastern side of the island. Summit solfatara areas of Kilauea are distinguished by moderate to high ambient SO{sub 2}, high H{sub 2}S at one location, and low H{sub 2}S at all others, and negligible HCl concentrations, as measured 1 m from degassing point-sources. Summit solfatara rain water has high sulfate and low chloride ion concentrations, and low pH.

  3. Assessment of the impact of the next generation solvent on DWPF melter off-gas flammability

    SciTech Connect

    Daniel, W. E.

    2013-02-13

    An assessment has been made to evaluate the impact on the DWPF melter off-gas flammability of replacing the current solvent used in the Modular Caustic-Side Solvent Extraction Process Unit (MCU) process with the Next Generation Solvent (NGS-MCU) and blended solvent. The results of this study showed that the concentrations of nonvolatile carbon and hydrogen of the current solvent in the Slurry Mix Evaporator (SME) product would both be about 29% higher than their counterparts of the NGS-MCU and blended solvent in the absence of guanidine partitioning. When 6 ppm of guanidine (TiDG) was added to the effluent transfer to DWPF to simulate partitioning for the NGS-MCU and blended solvent cases and the concentration of Isopar{reg_sign} L in the effluent transfer was controlled below 87 ppm, the concentrations of nonvolatile carbon and hydrogen of the NGS-MCU and blended solvent were still about 12% and 4% lower, respectively, than those of the current solvent. It is, therefore, concluded that as long as the volume of MCU effluent transfer to DWPF is limited to 15,000 gallons per Sludge Receipt and Adjustment Tank (SRAT)/SME cycle and the concentration of Isopar{reg_sign} L in the effluent transfer is controlled below 87 ppm, using the current solvent assumption of 105 ppm Isopar{reg_sign} L or 150 ppm solvent in lieu of NGS-MCU or blended solvent in the DWPF melter off-gas flammability assessment is conservative for up to an additional 6 ppm of TiDG in the effluent due to guanidine partitioning. This report documents the calculations performed to reach this conclusion.

  4. The impact of CO{sub 2} taxation on oil and gas production in Norway

    SciTech Connect

    Celius, H.K.; Ingeberg, K.

    1996-12-31

    This paper analyses the effect of the CO{sub 2} tax which was imposed on the burning of gas in the Norwegian sector of the North Sea, effective in 1991. The introduction of the tax resulted in a number of technical improvements aimed at the reduction of flaring, and increased energy efficiency of the power generation and total production process. An economic analysis was done to establish the following: (1) How did the tax affect the profitability of the technical measures which were implemented did the tax make it profitable, or would it have been profitable without the tax; (2) can we expect improvements to continue in the coming years; and (3) what will be the impact on the development of new fields, on field abandonment and on measures to improve oil recovery how much more oil will be left in the reservoir because of the tax. The first task was analyzed by an empirical approach, the latter based on models. The reduction in CO{sub 2} discharge during 1990-1993 was in the order of 8%, the main contribution came from reduction in flaring. This rate of improvement is not expected to continue, since most processes have been brought up to {open_quotes}state-of-the-art{close_quotes} by during these initial years. However, continuous energy optimization is still expected to give some improvements The majority of the technical measures taken to reduce the CO{sub 2} discharge proved to be profitable without the tax, and no unprofitable measures were implemented. The effect of earlier abandonment of fields is smaller than expected, advancing the abandonment by a few weeks for a typical North Sea field. The same seems to be the case for development of new fields. The additional reserves needed to compensate for the tax is in the order of 3 - 4% for a medium GOR oil field, above 5% for a larger gas field.

  5. Reducing Onshore Natural Gas and Oil Exploration and Production Impacts Using a Broad-Based Stakeholder Approach

    SciTech Connect

    Amy Childers

    2011-03-30

    Never before has the reduction of oil and gas exploration and production impacts been as important as it is today for operators, regulators, non-governmental organizations and individual landowners. Collectively, these stakeholders are keenly interested in the potential benefits from implementing effective environmental impact reducing technologies and practices. This research project strived to gain input and insight from such a broad array of stakeholders in order to identify approaches with the potential to satisfy their diverse objectives. The research team examined three of the most vital issue categories facing onshore domestic production today: (1) surface damages including development in urbanized areas, (2) impacts to wildlife (specifically greater sage grouse), and (3) air pollution, including its potential contribution to global climate change. The result of the research project is a LINGO (Low Impact Natural Gas and Oil) handbook outlining approaches aimed at avoiding, minimizing, or mitigating environmental impacts. The handbook identifies technical solutions and approaches which can be implemented in a practical and feasible manner to simultaneously achieve a legitimate balance between environmental protection and fluid mineral development. It is anticipated that the results of this research will facilitate informed planning and decision making by management agencies as well as producers of oil and natural gas. In 2008, a supplemental task was added for the researchers to undertake a 'Basin Initiative Study' that examines undeveloped and/or underdeveloped oil and natural gas resources on a regional or geologic basin scope to stimulate more widespread awareness and development of domestic resources. Researchers assessed multi-state basins (or plays), exploring state initiatives, state-industry partnerships and developing strategies to increase U.S. oil and gas supplies while accomplishing regional economic and environmental goals.

  6. The impact and importance of intercalibration and intercomparisons for greenhouse gas observational networks

    NASA Astrophysics Data System (ADS)

    Stavert, Ann; O'Doherty, Simon; Rigby, Matthew; Palmer, Paul; Stanley, Kieran; Young, Dickon; Lunt, Mark; Grant, Aoife; Pitt, Joseph; Bauguitte, Stephane; Helfter, Carole; Mullinger, Neil; Robinson, Andrew; Harris, Neil; Riddick, Stuart; Sonderfeld, Hannah; Boesch, Hartmut; Foster, Grant

    2016-04-01

    Motivated by the UK 2008 Climate Change Act, which requires the UK to decrease its greenhouse gas (GHG) emissions by 80% of 1990 levels by 2050, the Greenhouse gAs Uk and Global Emissons (GAUGE) project aims to better quantify UK CO2, CH4 and N2O emissions. As part of this project a UK-focused GHG observational network has been established, drawing together new and existing GHG data streams from regional to global scales. These included high-density regional studies, tall-tower sites, moving platforms (ferry and aircraft) and satellite observations. Under the project these observations will be combined with modelling approaches to better quantify and characterise UK GHG emissions and place them within a global context. This presentation will describe the efforts made to ensure that common calibration scales were used within the GAUGE project and an assessment of the intercomparability of the stationary sites and moving platforms (including 6 near surface regional focused sites, 6 tall tower sites, ferry and aircraft measurements). This assessment was undertaken using both a cylinder intercomparison program (ICP) and a comparison between co-located flask and in situ measurements. The majority of the sites agreed within the WMO comparability guidelines, however, small relative biases in CO2 and CH4 were identified at some sites. These biases generally increased with concentration, with differences up to 0.3ppm in CO2 and 3ppb CH4 observed between tall tower sites and mobile platforms, while larger biases were found at some of the regional study sites. In order to investigate the impact of biases of these types an experiment using pseudo emissions and observations was conducted. To achieve this, sets of emissions estimates for key GHG sources (e.g. for CH4 the sum of anthropogenic, biomass burning, wetlands, rice and oceans and other natural sources) were used to estimate the GHG concentrations at the GAUGE observation sites and mobile platforms via the Met office

  7. Gas and Particulate Aircraft Emissions Measurements: Impacts on local air quality.

    NASA Astrophysics Data System (ADS)

    Jayne, J. T.; Onasch, T.; Northway, M.; Canagaratna, M.; Worsnop, D.; Timko, M.; Wood, E.; Miake-Lye, R.; Herndon, S.; Knighton, B.; Whitefield, P.; Hagen, D.; Lobo, P.; Anderson, B.

    2007-12-01

    Air travel and freight shipping by air are becoming increasingly important and are expected to continue to expand. The resulting increases in the local concentrations of pollutants, including particulate matter (PM), volatile organic compounds (VOCs), and nitrogen oxides (NOX), can have negative impacts on regional air quality, human health and can impact climate change. In order to construct valid emission inventories, accurate measurements of aircraft emissions are needed. These measurements must be done both at the engine exit plane (certification) and downwind following the rapid cooling, dilution and initial atmospheric processing of the exhaust plume. We present here results from multiple field experiments which include the Experiment to Characterize Volatile Aerosol and Trace Species Emissions (EXCAVATE) and the four Aircraft Particle Emissions eXperiments (APEX- 1/Atlanta/2/3) which characterized gas and particle emissions from both stationary or in-use aircraft. Emission indices (EIs) for NOx and VOCs and for particle number concentration, refractory PM (black carbon soot) and volatile PM (primarily sulfate and organic) particles are reported. Measurements were made at the engine exit plane and at several downstream locations (10 and 30 meters) for a number of different engine types and engine thrust settings. A significant fraction of organic particle mass is composed of low volatility oil-related compounds and is not combustion related, potentially emitted by vents or heated surfaces within aircraft engines. Advected plumes measurements from in-use aircraft show that the practice of reduced thrust take-offs has a significant effect on total NOx and soot emitted in the vicinity of the airport. The measurements reported here represent a first observation of this effect and new insights have been gained with respect to the chemical processing of gases and particulates important to the urban airshed.

  8. 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

  9. Greenhouse gas emission impacts of alternative-fueled vehicles: Near-term vs. long-term technology options

    SciTech Connect

    Wang, M.Q.

    1997-05-20

    Alternative-fueled vehicle technologies have been promoted and used for reducing petroleum use, urban air pollution, and greenhouse gas emissions. In this paper, greenhouse gas emission impacts of near-term and long-term light-duty alternative-fueled vehicle technologies are evaluated. Near-term technologies, available now, include vehicles fueled with M85 (85% methanol and 15% gasoline by volume), E85 (85% ethanol that is produced from corn and 15% gasoline by volume), compressed natural gas, and liquefied petroleum gas. Long-term technologies, assumed to be available around the year 2010, include battery-powered electric vehicles, hybrid electric vehicles, vehicles fueled with E85 (ethanol produced from biomass), and fuel-cell vehicles fueled with hydrogen or methanol. The near-term technologies are found to have small to moderate effects on vehicle greenhouse gas emissions. On the other hand, the long-term technologies, especially those using renewable energy (such as biomass and solar energy), have great potential for reducing vehicle greenhouse gas emissions. In order to realize this greenhouse gas emission reduction potential, R and D efforts must continue on the long-term technology options so that they can compete successfully with conventional vehicle technology.

  10. Impact of the Keystone XL pipeline on global oil markets and greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Erickson, Peter; Lazarus, Michael

    2014-09-01

    Climate policy and analysis often focus on energy production and consumption, but seldom consider how energy transportation infrastructure shapes energy systems. US President Obama has recently brought these issues to the fore, stating that he would only approve the Keystone XL pipeline, connecting Canadian oil sands with US refineries and ports, if it `does not significantly exacerbate the problem of carbon pollution'. Here, we apply a simple model to understand the implications of the pipeline for greenhouse gas emissions as a function of any resulting increase in oil sands production. We find that for every barrel of increased production, global oil consumption would increase 0.6 barrels owing to the incremental decrease in global oil prices. As a result, and depending on the extent to which the pipeline leads to greater oil sands production, the net annual impact of Keystone XL could range from virtually none to 110 million tons CO2 equivalent annually. This spread is four times wider than found by the US State Department (1-27 million tons CO2e), who did not account for global oil market effects. The approach used here, common in lifecycle analysis, could also be applied to other pending fossil fuel extraction and supply infrastructure.

  11. 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. PMID:26393414

  12. Municipal solid waste management scenarios for Attica and their greenhouse gas emission impact.

    PubMed

    Papageorgiou, Asterios; Karagiannidis, Avraam; Barton, John R; Kalogirou, Efstratios

    2009-11-01

    Disposal of municipal solid waste in sanitary landfills is still the main waste management method in the Attica region, as in most regions of Greece. Nevertheless, diversion from landfilling is being promoted by regional plans, in which the perspectives of new waste treatment technologies are being evaluated. The present study aimed to assess the greenhouse gas (GHG) emissions impact of different municipal solid waste treatment technologies currently under assessment in the new regional plan for Attica. These technologies are mechanical-biological treatment, mass-burn incineration and mechanical treatment and have been assessed in the context of different scenarios. The present study utilized existing methodologies and emission factors for the quantification of GHG emissions from the waste management process and found that all technologies under assessment could provide GHG emission savings. However, the performance and ranking of these technologies is strongly dependent on the existence of end markets for the waste-derived fuels produced by the mechanical-biological treatment processes. In the absence of these markets the disposal of these fuels would be necessary and thus significant GHG savings would be lost. PMID:19837710

  13. Impact of Asphaltenes and Resins on the Wetting Characteristics of Tars at Former Manufactured Gas Plants

    NASA Astrophysics Data System (ADS)

    Hauswirth, S. C.; Birak, P. S.; Rylander, S.; Pedit, J. A.; Miller, C. T.

    2008-12-01

    Tars produced as a byproduct of coal and oil gasification at manufactured gas plants (MGPs) during the 19th and early 20th centuries were often released into the environment through poor disposal practices or leaks in holding tanks and piping. These tars are persistent contaminants, leaching polycyclic aromatic hydrocarbons (PAHs) into groundwater and posing a significant risk to human and ecological health. MGP tars also have several properties that make them notoriously difficult to remediate. They are denser than water, so they can migrate to depths which make direct removal difficult or impossible, and their relatively high viscosities and ability to alter the wetting characteristics of porous media result in inefficient removal by traditional pump-and-treat methods. In this study, we investigate the last of these properties. Previous studies have linked wetting changes to asphaltenes---polar, high molecular weight compounds present in the tars. However, we have conducted qualitative bottle tests for tar samples collected from two former MGPs which indicate that there is no direct correlation between asphaltene concentration and the tendency to alter wetting characteristics of porous media. To better understand the factors controlling wetting behavior, we isolate asphaltenes and resins, another class of polar compounds, from a tar sample and recombine them with the remaining PAH mixture to create a series of tars of varying composition. We assess the relative impact of each of the fractions on wettability through contact angle measurements conducted at three different pHs.

  14. Using biodiversity methods to assess the impacts of oil and gas development in tropical rain forests

    SciTech Connect

    Reagan, D.P.; Silva del Poso, X. |

    1995-06-01

    Oil and gas development in tropical rain forests has attracted international attention because of the potentially adverse effects on the forest ecosystems. Biodiversity is a topic of particular concern, but is difficult to assess for small areas of disturbance. In July 1992 we used light traps to compare insect diversity at canopy and ground level as a means of detecting the impacts of an exploratory well site and related facilities within mature Amazonian rain forest in the Oriente Province of Ecuador. Replicate samples were collected at the well site, in a nearby area of agricultural development, and in a reference site within mature forest. Species richness was determined, and diversity indices were calculated for each set of samples. Results indicated that changes in diversity could be detected in the canopy and at ground level at the well site, but that the reduction in diversity was small. Biological diversity was substantially reduced in the area of agricultural development. Limitations and possible applications of this approach are discussed.

  15. Impact of Unconventional Shale Gas Waste Water Disposal on Surficial Streams

    NASA Astrophysics Data System (ADS)

    Cozzarelli, I.; Akob, D.; Mumford, A. C.

    2014-12-01

    The development of unconventional natural gas resources has been rapidly increasing in recent years, however, the environmental impacts and risks are not yet well understood. A single well can generate up to 5 million L of produced water (PW) consisting of a blend of the injected fluid and brine from a shale formation. With thousands of wells completed in the past decade, the scope of the challenge posed in the management of this wastewater becomes apparent. The USGS Toxic Substances Hydrology Program is studying both intentional and unintentional releases of PW and waste solids. One method for the disposal of PW is underground injection; we are assessing the potential risks of this method through an intensive, interdisciplinary study at an injection disposal facility in the Wolf Creek watershed in WV. Disposal of PW via injection begun in 2002, with over 5.5 mil. L of PW injected to date. The facility consists of the injection well, a tank farm, and two former holding ponds (remediated in early 2014) and is bordered by two small tributaries of Wolf Creek. Water and sediments were acquired from these streams in June 2014, including sites upstream, within, and downstream from the facility. We are analyzing aqueous and solid phase geochemistry, mineralogy, hydrocarbon content, microbial community composition, and potential toxicity. Field measurements indicated that conductivity downstream (416 μS/cm) was elevated in comparison to upstream (74 μS/cm) waters. Preliminary data indicated elevated Cl- (115 mg/L) and Br- (0.88 mg/L) concentrations downstream, compared to 0.88 mg/L Cl- and <0.03 mg/L Br- upstream of the facility. Because elevated TDS is a marker of PW, these data provide a first indication that PW from the facility is impacting nearby streams. In addition, total Fe concentrations downstream were 8.1 mg/L, far in excess of the 0.13 mg/L found upstream from the facility, suggesting the potential for microbial Fe cycling. We are conducting a broad suite of

  16. Climate Change Impacts on US Agriculture and the Benefits of Greenhouse Gas Mitigation

    NASA Astrophysics Data System (ADS)

    Monier, E.; Sue Wing, I.; Stern, A.

    2014-12-01

    As contributors to the US EPA's Climate Impacts and Risk Assessment (CIRA) project, we present empirically-based projections of climate change impacts on the yields of five major US crops. Our analysis uses a 15-member ensemble of climate simulations using the MIT Integrated Global System Model (IGSM) linked to the NCAR Community Atmosphere Model (CAM), forced by 3 emissions scenarios (a "business as usual" reference scenario and two stabilization scenarios at 4.5W/m2 and 3.7 W/m2 by 2100), quantify the agricultural impacts avoided due to greenhouse gas emission reductions. Our innovation is the coupling of climate model outputs with empirical estimates of the long-run relationship between crop yields and temperature, precipitation and soil moisture derived from the co-variation between yields and weather across US counties over the last 50 years. Our identifying assumption is that since farmers' planting, management and harvesting decisions are based on land quality and expectations of weather, yields and meteorological variables share a long-run equilibrium relationship. In any given year, weather shocks cause yields to diverge from their expected long-run values, prompting farmers to revise their long-run expectations. We specify a dynamic panel error correction model (ECM) that statistically distinguishes these two processes. The ECM is estimated for maize, wheat, soybeans, sorghum and cotton using longitudinal data on production and harvested area for ~1,100 counties from 1948-2010, in conjunction with spatial fields of 3-hourly temperature, precipitation and soil moisture from the Global Land Data Assimilation System (GLDAS) forcing and output files, binned into annual counts of exposure over the growing season and mapped to county centroids. For scenarios of future warming the identical method was used to calculate counties' current (1986-2010) and future (2036-65 and 2086-2110) distributions of simulated 3-hourly growing season temperature, precipitation

  17. Characterization of VOCs Across Pennsylvania: Assessing Emissions from Rural, Forested, Agricultural and Natural Gas Drilling-Impacted Areas

    NASA Astrophysics Data System (ADS)

    Grannas, A. M.; Fuentes, J. D.; Ramos-Garcés, F.; Wang, D. K.; Martins, D. K.

    2012-12-01

    Volatile organic compounds (VOCs) of both biogenic and anthropogenic origin are important to troposphere chemistry, particularly the formation of photochemical smog and secondary organic aerosol. There is concern that increased natural gas exploration may lead to increased emissions of certain VOCs during well development and due to fugitive emissions from operational well sites and pipelines. For a six-day period in June 2012, a variety of VOCs were measured using canister sampling from a mobile measurement platform. Transects from southwestern to northeastern Pennsylvania were studied, with samples obtained in rural, forested, urban, farm-impacted and gas well-impacted sites. As expected, biogenic VOCs and isoprene oxidation products were enhanced in forested regions, while anthropogenic non-methane hydrocarbons were enhanced in urban areas. BTEX (benzene, toluene, ethylbenzene and xylenes) was enhanced in urban areas, but the concentrations of BTEX measured near developing and existing natural gas sites were similar to rural and forested sites. Halogenated hydrocarbons and Freon compounds were consistent at all site locations. We will discuss the specific concentrations and signatures of these compounds and assess the potential impact of agricultural activities and gas well development on the observed VOC concentrations and variability.

  18. Climate impacts of air quality policy: switching to a natural gas-fueled public transportation system in New Delhi.

    PubMed

    Reynolds, Conor C O; Kandlikar, Milind

    2008-08-15

    Between 2001 and 2003, public transport vehicles in New Delhi were required to switch their fuel to natural gas in an attemptto reduce their air pollution impacts. This study examines the climatic impacts of New Delhi's fuel switching policy, and outlines implications for such efforts in rapidly industrializing countries. Natural gas is mostly composed of methane, an important greenhouse gas. Emitted aerosols (black carbon, particulate organic carbon, and sulfate) also cause radiative forcing. We find that methane and black carbon emissions are critical contributors to the change in carbon dioxide equivalent [CO2(e)] emissions. In New Delhi, the switch to natural gas results in a 30% increase in CO2(e) when the impact of aerosols is not considered. However, when aerosol emissions are taken into account in our model, the net effect of the switch is estimated to be a 10% reduction in CO2(e), and there may be as much as a 30% reduction in CO2(e). There is significant potential for emissions reductions through the United Nations Framework Convention on Climate Change (UNFCCC) Clean Development Mechanism for such fuel switching projects. PMID:18767636

  19. Comparing Statewide Economic Impacts of New Generation from Wind, Coal, and Natural Gas in Arizona, Colorado, and Michigan

    SciTech Connect

    Tegen, S.

    2006-05-01

    With increasing concerns about energy independence, job outsourcing, and risks of global climate change, it is important for policy makers to understand all impacts from their decisions about energy resources. This paper assesses one aspect of the impacts: direct economic effects. The paper compares impacts to states from equivalent new electrical generation from wind, natural gas, and coal. Economic impacts include materials and labor for construction, operations, maintenance, fuel extraction, and fuel transport, as well as project financing, property tax, and landowner revenues. We examine spending on plant construction during construction years, in addition to all other operational expenditures over a 20-year span. Initial results indicate that adding new wind power can be more economically effective than adding new gas or coal power and that a higher percentage of dollars spent on coal and gas will leave the state. For this report, we interviewed industry representatives and energy experts, in addition to consulting government documents, models, and existing literature. The methodology for this research can be adapted to other contexts for determining economic effects of new power generation in other states and regions.

  20. Comparing Statewide Economic Impacts of New Generation from Wind, Coal, and Natural Gas in Arizona, Colorado, and Michigan: Preprint

    SciTech Connect

    Tegen, S.

    2005-08-01

    With increasing concerns about energy independence, job outsourcing, and risks of global climate change, it is important for policy makers to understand all impacts from their decisions about energy resources. This paper assesses one aspect of the impacts: direct economic effects. The paper compares impacts to states from equivalent new electrical generation from wind, natural gas, and coal. Economic impacts include materials and labor for construction, operations, maintenance, fuel extraction, and fuel transport, as well as project financing, property tax, and landowner revenues. We examine spending on plant construction during construction years, in addition to all other operational expenditures over a 20-year span. Initial results indicate that adding new wind power can be more economically effective than adding new gas or coal power, and that a higher percentage of dollars spent on coal and gas will leave the state. For this report, we interviewed industry representatives and energy experts, in addition to consulting government documents, models, and existing literature. The methodology for this research can be adapted to other contexts for determining economic effects of new power generation in other states and regions.

  1. Analysis of tert-butyldimethylsilyl derivatives in heavy gas oil from Brazilian naphthenic acids by gas chromatography coupled to mass spectrometry with electron impact ionization.

    PubMed

    Vaz de Campos, Maria Cecília; Oliveira, Eniz Conceição; Filho, Pedro José Sanches; Piatnicki, Clarisse Maria Sartori; Caramão, Elina Bastos

    2006-02-10

    Naphthenic acids, C(n)H(2n+Z)O(2), are a complex mixture of alkyl-substituted acyclic and cycle-aliphatic carboxylic acids. The content of naphthenic acids and their derivatives in crude oils is very small, which hinders their extraction from matrixes of wide and varied composition. In this work, liquid-liquid extraction, followed by solid phase extraction with an ion exchange resin (Amberlyst A-27) and ultrasound desorption were used to isolate the acid fraction from heavy gas oil of Marlim petroleum (Campos, Rio de Janeiro, Brazil). The analysis was accomplished through gas chromatography coupled to mass spectrometry with electron impact ionization, after derivatization with N-methyl-N-(tert-butyldimethylsilyl)trifluoracetamide (MTBDMSTFA). The results indicate the presence of carboxylic acids belonging to families of alicyclic and naphthenic compounds which contain up to four rings in the molecule. PMID:16439253

  2. The impact of a pulsing groundwater table on greenhouse gas emissions in riparian grey alder stands.

    PubMed

    Mander, Ülo; Maddison, Martin; Soosaar, Kaido; Teemusk, Alar; Kanal, Arno; Uri, Veiko; Truu, Jaak

    2015-02-01

    Floods control greenhouse gas (GHG) emissions in floodplains; however, there is a lack of data on the impact of short-term events on emissions. We studied the short-term effect of changing groundwater (GW) depth on the emission of (GHG) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in two riparian grey alder (Alnus incana) stands of different age in Kambja, southern Estonia, using the opaque static chamber (five replicates in each site) and gas chromatography methods. The average carbon and total nitrogen content in the soil of the old alder (OA) stand was significantly higher than in the young alder (YA) stand. In both stands, one part was chosen for water table manipulation (Manip) and another remained unchanged with a stable and deeper GW table. Groundwater table manipulation (flooding) significantly increases CH4 emission (average: YA-Dry 468, YA-Manip 8,374, OA-Dry 468, OA-Manip 4,187 μg C m(-2) h(-1)) and decreases both CO2 (average: OA-Dry 138, OA-Manip 80 mg C m(-2) h(-1)) and N2O emissions (average: OA-Dry 23.1, OA-Manip 11.8 μg N m(-2) h(-1)) in OA sites. There was no significant difference in CO2 and CH4 emissions between the OA and YA sites, whereas in OA sites with higher N concentration in the soil, the N2O emission was significantly higher than at the YA sites. The relative CO2 and CH4 emissions (the soil C stock-related share of gaseous losses) were higher in manipulated plots showing the highest values in the YA-Manip plot (0.03 and 0.0030 % C day(-1), respectively). The soil N stock-related N2O emission was very low achieving 0.000019 % N day(-1) in the OA-Dry plot. Methane emission shows a negative correlation with GW, whereas the 20 cm depth is a significant limit below which most of the produced CH4 is oxidized. In terms of CO2 and N2O, the deeper GW table significantly increases emission. In riparian zones of headwater streams, the short-term floods (e.g. those driven by extreme climate events) may significantly enhance

  3. Simultaneous water and gas injection pilot at the Kuparuk River Field, reservoir impact

    SciTech Connect

    Ma, T.D.; Rugen, J.A.; Stoisits, R.F.

    1995-12-31

    Immiscible water-alternating-gas injection has effectively managed produced gas at the Kuparuk River Field, increasing field oil rate and recovery. Although IWAG economics are very favorable, a pilot study was undertaken to ascertain whether the separate gas injection system can be eliminated by simultaneously injecting water and gas in waterflood lines. Static mixers were found to be necessary to disperse gas in a multiphase mixture flowing through a network of pipes. However, scale-up criteria for gas dispersing static mixers in multiphase pipe networks require additional refinement. Reservoir simulation done to support the pilot project showed that simultaneous water-and-gas injection should provide better control of gas mobility than IWAG. This resulted in increased oil recovery and more steady gas production. During the typical IWAG process, the magnitude and the cyclic nature of GOR responses have caused problems for gas handling at the field facilities. During the pilot loss of injection rate was observed as the gas fraction in the injection mixture increased and the surface injection pressure was kept stable at about 2800 psi. Examination of Well 2D-16 data suggests that the observed rate loss was more likely due to the lower bottom-hole pressures than the relative permeability effects expected of two-phase flow in porous media.

  4. Health Impact Assessments, Regulation, and the Unconventional Gas Industry in the UK: Exploiting Resources, Ideology, and Expertise?

    PubMed

    Watterson, Andrew; Dinan, William

    2016-02-01

    Health impact assessments (HIAs) across the globe may be used by governments and industries to secure approval for unconventional gas extraction developments. HIA is an umbrella term that covers an array of health review and assessment practices, ranging from the very general to quite specific and technical health studies. Our concern in this paper is principally with the specialist end of the HIA continuum and particularly its application to unconventional gas extraction in the UK. We outline the context within which HIAs in unconventional gas extraction may be conducted. We then explain what HIAs may do. HIAs are often commissioned from consultancy companies to assess unconventional gas extraction project risks and benefits and propose mitigation measures. Communities can rarely afford HIAs in the planning process and may consider them biased when commissioned by vested interests. The oil and gas industry uses these techniques for its own ends. Hiring experts, be they specialist consultants, researchers, lobbyists, ex-government officials, or regulators, to influence planning and regulation is a well-tried tactic and structural advantage exploited by industry in seeking license to operate. Equitable and ethical HIA principles are urgently needed in the UK in relation to unconventional gas to secure the integrity and probity of the emerging regulatory system and address concerns regarding unregulated practitioners. PMID:26531123

  5. Greenhouse gas impacts of declining hydrocarbon resource quality: Depletion, dynamics, and process emissions

    NASA Astrophysics Data System (ADS)

    Brandt, Adam Robert

    This dissertation explores the environmental and economic impacts of the transition to hydrocarbon substitutes for conventional petroleum (SCPs). First, mathematical models of oil depletion are reviewed, including the Hubbert model, curve-fitting methods, simulation models, and economic models. The benefits and drawbacks of each method are outlined. I discuss the predictive value of the models and our ability to determine if one model type works best. I argue that forecasting oil depletion without also including substitution with SCPs results in unrealistic projections of future energy supply. I next use information theoretic techniques to test the Hubbert model of oil depletion against five other asymmetric and symmetric curve-fitting models using data from 139 oil producing regions. I also test the assumptions that production curves are symmetric and that production is more bell-shaped in larger regions. Results show that if symmetry is enforced, Gaussian production curves perform best, while if asymmetry is allowed, asymmetric exponential models prove most useful. I also find strong evidence for asymmetry: production declines are consistently less steep than inclines. In order to understand the impacts of oil depletion on GHG emissions, I developed the Regional Optimization Model for Emissions from Oil Substitutes (ROMEO). ROMEO is an economic optimization model of investment and production of fuels. Results indicate that incremental emissions (with demand held constant) from SCPs could be 5-20 GtC over the next 50 years. These results are sensitive to the endowment of conventional oil and not sensitive to a carbon tax. If demand can vary, total emissions could decline under a transition because the higher cost of SCPs lessens overall fuel consumption. Lastly, I study the energetic and environmental characteristics of the in situ conversion process, which utilizes electricity to generate liquid hydrocarbons from oil shale. I model the energy inputs and outputs

  6. Viscous Effects on Impact Probes in a Subsonic Rarified Gas Flow

    NASA Technical Reports Server (NTRS)

    Kane, E. D.; Schaaf, S. A.

    1951-01-01

    The problem of time response of pressure gaging systems used with low density flows has been discussed in Ref ]4, and the effect of outgassing on pressure magnitudes was indicated in the same reference. Briefly, gases or vapors adhering to the internal walls of the pressure gaging system behave like gas sources and produce a pressure rise in the gage system which has no relation to the external flow. The effect can also occur in the reverse direction, with "in-gassing" or the action of an effective sink in the gage system as gases entering through the probe orifice are adsorbed to the walls. For given surface conditions, the magnitude of the pressure error to be expected due to out-gassing depends on the dimensions of the probe system. In the present tests, it was desirable to use the smallest possible probe to yield the lowest possible Reynolds number. The lower limit on size was fixed by outgassing effects, evaluated by the following procedure. 2.0 PROCEDURE The pumping system was adjusted to give a pressure, measured at the reservoir, of 9 microns Hg with no flow into the wind tunnel. The upstream metering valve was then opened and the air flow rate adjusted to give a pressure of 100 microns in the reservoir under steady flow conditions, The pressure read by one of the impact tubes, inserted into the flow, was measured. The upstream metering valve was then closed rapid)y, and the reservoir pressure, p0, and the impact probe pressure, Pj, were measured simultaneously at definite time intervals. Another probe was inserted into the flow and the procedure repeated, until the pressure-time data had been obtained for each probe investigated. The results for a series of tests Involving probe Nos.l, 2 and 3 are shown on HYD 2616 300 RESULTS From HYD 2616, It is clear that the smallest probe (No.3) requires the longest time to reach equilibrium. After a sufficient time has elapsed (about 180 seconds), this probe read the same, within the accuracy of measurement, as the

  7. Tensile and Impact Toughness Properties of Gas Tungsten Arc Welded and Friction Stir Welded Interstitial Free Steel Joints

    NASA Astrophysics Data System (ADS)

    Lakshminarayanan, A. K.; Balasubramanian, V.

    2011-02-01

    Welded regions of interstitial free (IF) steel grades in the vicinity of weld center exhibits larger grains because of the prevailing thermal conditions during weld metal solidification. This often causes inferior weld mechanical properties. In the present study, tensile properties, charpy impact toughness, microhardness, microstructure, lowest hardness distribution profile, and fracture surface morphology of the gas tungsten arc welded (GTAW) and friction stir welded joints were evaluated, and the results are compared. From this investigation, it is found that friction stir welded joint of IF steel showed superior tensile and impact properties compared with GTAW joint, and this is mainly due to the formation of very fine, equiaxed microstructure in the weld zone.

  8. The impact of gas bulk rotation on the Lyα line

    SciTech Connect

    Garavito-Camargo, Juan N.; Forero-Romero, Jaime E.; Dijkstra, Mark E-mail: je.forero@uniandes.edu.co

    2014-11-10

    We present results of radiative transfer calculations to measure the impact of gas bulk rotation on the morphology of the Lyα emission line in distant galaxies. We model a galaxy as a sphere with an homogeneous mixture of dust and hydrogen at a constant temperature. These spheres undergo solid-body rotation with maximum velocities in the range 0-300 km s{sup –1} and neutral hydrogen optical depths in the range τ{sub H} = 10{sup 5}-10{sup 7}. We consider two types of source distributions in the sphere: central and homogeneous. Our main result is that rotation introduces a dependence of the line morphology with viewing angle and rotational velocity. Observations with a line of sight parallel to the rotation axis yield line morphologies similar to the static case. For lines of sight perpendicular to the rotation axis, both the intensity at the line center and the line width increase with rotational velocity. Along the same line of sight, the line becomes single peaked at rotational velocities close to half the line width in the static case. Notably, we find that rotation does not induce any spatial anisotropy in the integrated line flux, the escape fraction or the average number of scatterings. This is because Lyman scattering through a rotating solid-body proceeds identically to the static case. The only difference is the Doppler shift from the different regions in the sphere that move with respect to the observer. This allows us to derive an analytic approximation for the viewing-angle dependence of the emerging spectrum, as a function of rotational velocity.

  9. Impacts of mustard gas exposure on veterans mental health: A study on the role of education

    PubMed Central

    Karami, Gholam-Reza; Ameli, Javad; Roeintan, Rahim; Jonaidi-Jafari, Nematollah; Saburi, Amin

    2013-01-01

    Background: The mustard gas (MG) exposure can impair physical health and therefore increase the probability of the posttraumatic stress disorder (PTSD) and psychological disorders. Aim: The aim of this study was to investigate long-term effects of MG exposure on veterans’ mental health. Materials and Methods: This was a cross-sectional study. In order to assess prevalence of mental health and PTSD of 100 MG victims 25 years after the exposure to MG in Iran-Iraq conflict, the general health questionnaire (GHQ-28) and Impact of Event Scale-Revised, respectively was administered. Results: The mean (±standard deviation (SD)) age of participants was 40.63 (±5.86) years. The mean GHQ-28 (47.34) of the study group was higher compared to standardized cutoff point (23) of the Iranian community. Also, it was found that 38 participants (38%) suffer from PTSD. The results of this study showed that academic education in the PTSD group was less than that in the non-PTSD group (P=0.03). In addition, in multivariate analysis it was found that only education level of the veterans and their wives were effective on the mental health score (adjusted P=0.036 and 0.041, respectively). The mean score of depression and psychosocial activity subscale in patients at higher education level was lower than patients at lower education level (P<0.05). Conclusion: This study found that sulfur mustard (SM) exposure can be effect on mental health even 25 years after exposure. Therefore, the psychological state should be more considered in chemical injured veterans and it is important that providing more mental health centers for this community. PMID:24459369

  10. Impact of the choice of emission metric on greenhouse gas abatement and costs

    NASA Astrophysics Data System (ADS)

    van den Berg, Maarten; Hof, Andries F.; van Vliet, Jasper; van Vuuren, Detlef P.

    2015-02-01

    This paper analyses the effect of different emission metrics and metric values on timing and costs of greenhouse gas mitigation in least-cost emission pathways aimed at a forcing level of 3.5 W m-2 in 2100. Such an assessment is currently relevant in view of UNFCCC’s decision to replace the values currently used. An emission metric determines the relative weights of non-CO2 greenhouse gases in obtaining CO2-equivalent emissions. For the first commitment period of the Kyoto Protocol, the UNFCCC has used 100 year global warming potential (GWP) values as reported in IPCC’s Second Assessment Report. For the second commitment period, the UNFCCC has decided to use 100 year GWP values from IPCC’s Fourth Assessment Report. We find that such a change has only a minor impact on (the optimal timing of) global emission reductions and costs. However, using 20 year or 500 year GWPs to value non-CO2 greenhouse gases does result in a significant change in both costs and emission reductions in our model. CO2 reductions are favored over non-CO2 gases when the time horizon of the GWPs is increased. Application of GWPs with time horizons longer than 100 year can increase abatement costs substantially, by about 20% for 500 year GWPs. Surprisingly, we find that implementation of a metric based on a time-dependent global temperature potential does not necessary lead to lower abatement costs. The crucial factor here is how fast non-CO2 emissions can be reduced; if this is limited, the delay in reducing methane emissions cannot be (fully) compensated for later in the century, which increases total abatement costs.

  11. Isolated crater formation by gas cluster ion impact and their use as templates for carbon nanotube growth

    NASA Astrophysics Data System (ADS)

    Toyoda, Noriaki; Kimura, Asahi; Yamada, Isao

    2016-03-01

    Crater-like defects formations with gas cluster ion beams (GCIB) were used as templates for carbon nanotube (CNT) growth. Upon a gas cluster ion impact, dense energy is deposited on a target surface while energy/atom of gas cluster ion is low, which creates crater-like defects. Si and SiO2 were irradiated with Ar-GCIB, subsequently CNTs were grown with an alcohol catalytic CVD using Co and ethanol as catalyst and precursor, respectively. From SEM, AFM and Raman spectroscopy, it was shown that growth of CNT with small diameter was observed on SiO2 with Ar-GCIB irradiation. On Si targets, formation of craters with bottom oxide prevented Co diffusion during CNT growth, as a result, CNT growth was observed only on Si irradiated with high-energy Ar-GCIB. These results showed that isolated defects created by GCIB can be used as templates for nanotube growth.

  12. Aerosols versus Greenhouse Gas Climate Effects: Impacts on Temperature and Precipitation Changes and Implications for Decision-making

    NASA Astrophysics Data System (ADS)

    Ramaswamy, V.; Horowitz, L. W.; Ming, Y.; Schwarzkopf, M. D.; Levy, H.

    2011-12-01

    Over the 20th Century, it is understood that anthropogenic emissions of aerosols have partially offset the influence of the greenhouse gas emissions on the global-mean and continental surface temperatures, consistent with the difference in their respective radiative forcings. The effect of aerosols versus greenhouse gases on precipitation and hydrologic cycle, however, is not so straightforward. Using a set of NOAA/ GFDL global climate model simulations, the impacts due to anthropogenic aerosol emissions are characterized and compared with those due to greenhouse gas emissions. This is performed for the global and continental spatial scales. The degree of aerosol offset of the greenhouse gas effects in terms of evaporation at the surface and precipitation can be greater than that occurring in the case of surface temperature, with some regions experiencing an impact that is more governed by aerosols than by the greenhouse gas emissions. These results have significant implications for decision-making concerning future emissions and mitigation/ adaptation to climate change. The removal of aerosols from the atmosphere in the near future to obtain improvements in air quality would exacerbate the warming due to greenhouse gases arising over a large part of the globe. However, the corresponding impacts due to aerosol reductions on the global evaporation and precipitation in the 21st Century, including changes in regional phenomena such as the Asian precipitation, are less clear but are important to understand. Compounding the problem is the set of uncertainties arising from lack of or incomplete knowledge of the various species of aerosols (e.g., scattering and absorbing aerosols; sulfate, soot, dust), interactions of aerosols with clouds, and the nature of the emissions scenario. An accompanying challenge is to accurately characterize and communicate this exceptional issue in climate change science to the diverse group of stakeholders, sectors and decision-makers, who

  13. Hurricane Andrew's impact on natural gas and oil facilities on the outer continental shelf (interim report as of November 1993)

    SciTech Connect

    Daniels, G.R.

    1994-01-01

    The interim report reviews Hurricane Andrew's impact on Federal Outer Continental Shelf (OCS) natural gas and oil drilling and production facilities. The report provides background on Hurricane Andrew's progression, discusses how OCS operators responded to the storm, summarizes the types of damage to offshore facilies caused by Hurricane Andrew, and discusses Minerals Management Service's continuing damage assessment and repair efforts. The summaries of damage estimates are presented in tables in Appendix 1. A glossary of report terminology is provided in Appendix 2.

  14. Energy Market and Economic Impacts Proposal to Reduce Greenhouse Gas Intensity with a Cap and Trade System

    EIA Publications

    2007-01-01

    This report was prepared by the Energy Information Administration (EIA), in response to a September 27, 2006, request from Senators Bingaman, Landrieu, Murkowski, Specter, Salazar, and Lugar. The Senators requested that EIA assess the impacts of a proposal that would regulate emissions of greenhouse gases (GHGs) through an allowance cap-and-trade system. The program would set the cap to achieve a reduction in emissions relative to economic output, or greenhouse gas intensity.

  15. The potential impact of renewable energy deployment on natural gas prices in New England

    SciTech Connect

    Wiser, Ryan; Bolinger, Mark

    2004-09-20

    Concerns about the price and supply of natural gas have deepened in recent years both nationally and in New England. Renewable energy (RE) technologies can directly hedge natural gas price risk by reducing the need to purchase variable-price natural gas-fired electricity generation, and replacing that generation with fixed-price renewable electricity supply. In addition to its direct contribution to price stability, an increasing number of studies show that renewable energy deployment can also put downward pressure on natural gas prices by reducing demand for gas among gas-fired generators. These gas price reductions are, in turn, expected to reduce electricity prices and--more importantly--directly reduce consumer natural gas bills. Many recent studies have found that this effect may be significant, substantially benefiting consumers. These studies are reviewed in the attached paper, published in the proceedings of a recent national energy conference. An important consideration is that--strictly speaking--this price reduction represents a consumer benefit that comes at the expense of producers; it therefore represents a wealth transfer, not a net gain in social welfare. That said, current concerns about the price and supply of natural gas suggest that policymakers may want to pursue actions that reduce the strain of high prices on consumer energy bills.

  16. Regional air quality impacts of increased natural gas production and use in Texas.

    PubMed

    Pacsi, Adam P; Alhajeri, Nawaf S; Zavala-Araiza, Daniel; Webster, Mort D; Allen, David T

    2013-04-01

    Natural gas use in electricity generation in Texas was estimated, for gas prices ranging from $1.89 to $7.74 per MMBTU, using an optimal power flow model. Hourly estimates of electricity generation, for individual electricity generation units, from the model were used to estimate spatially resolved hourly emissions from electricity generation. Emissions from natural gas production activities in the Barnett Shale region were also estimated, with emissions scaled up or down to match demand in electricity generation as natural gas prices changed. As natural gas use increased, emissions decreased from electricity generation and increased from natural gas production. Overall, NOx and SO2 emissions decreased, while VOC emissions increased as natural gas use increased. To assess the effects of these changes in emissions on ozone and particulate matter concentrations, spatially and temporally resolved emissions were used in a month-long photochemical modeling episode. Over the month-long photochemical modeling episode, decreases in natural gas prices typical of those experienced from 2006 to 2012 led to net regional decreases in ozone (0.2-0.7 ppb) and fine particulate matter (PM) (0.1-0.7 μg/m(3)). Changes in PM were predominantly due to changes in regional PM sulfate formation. Changes in regional PM and ozone formation are primarily due to decreases in emissions from electricity generation. Increases in emissions from increased natural gas production were offset by decreasing emissions from electricity generation for all the scenarios considered. PMID:23441728

  17. Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

    SciTech Connect

    Alptekin, Gokhan

    2013-02-15

    Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H2S, NH3, HCN, AsH3, PH3, HCl, NaCl, KCl, AS3, NH4NO3, NH4OH, KNO3, HBr, HF, and HNO3) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.

  18. 75 FR 47302 - Pacific Gas & Electric Company; Notice of Public Meeting on Draft Environmental Impact Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... Federal Energy Regulatory Commission Pacific Gas & Electric Company; Notice of Public Meeting on Draft... number (e.g., P-606) excluding the last three digits in the docket number field to access the document... the project is Pacific Gas and Electric Company. This meeting is open to the public. At this...

  19. Cropping System Impacts on Greenhouse Gas Emissions in the Cool, Humid Northeastern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estimating global greenhouse gas (GHG) emissions from agriculture requires regional measurements of different production systems. A long-term potato cropping systems experiment in Maine was designed to contribute to the USDA-ARS national project entitled Greenhouse Gas Reduction through Agricultural...

  20. Localized Starbursts in Dwarf Galaxies Produced by the Impact of Low-metallicity Cosmic Gas Clouds

    NASA Astrophysics Data System (ADS)

    Sánchez Almeida, J.; Elmegreen, B. G.; Muñoz-Tuñón, C.; Elmegreen, D. M.; Pérez-Montero, E.; Amorín, R.; Filho, M. E.; Ascasibar, Y.; Papaderos, P.; Vílchez, J. M.

    2015-09-01

    Models of galaxy formation predict that gas accretion from the cosmic web is a primary driver of star formation over cosmic history. Except in very dense environments where galaxy mergers are also important, model galaxies feed from cold streams of gas from the web that penetrate their dark matter halos. Although these predictions are unambiguous, the observational support has been indirect so far. Here, we report spectroscopic evidence for this process in extremely metal-poor galaxies (XMPs) of the local universe, taking the form of localized starbursts associated with gas having low metallicity. Detailed abundance analyses based on Gran Telescopio Canarias optical spectra of 10 XMPs show that the galaxy hosts have metallicities around 60% solar, on average, while the large star-forming regions that dominate their integrated light have low metallicities of some 6% solar. Because gas mixes azimuthally in a rotation timescale (a few hundred Myr), the observed metallicity inhomogeneities are only possible if the metal-poor gas fell onto the disk recently. We analyze several possibilities for the origin of the metal-poor gas, favoring the metal-poor gas infall predicted by numerical models. If this interpretation is correct, XMPs trace the cosmic web gas in their surroundings, making them probes to examine its properties.

  1. The Impact of Molecular Gas on Mass Models of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Frank, B. S.; de Blok, W. J. G.; Walter, F.; Leroy, A.; Carignan, C.

    2016-04-01

    We present CO velocity fields and rotation curves for a sample of nearby galaxies, based on data from HERACLES. We combine our data with THINGS, SINGS, and KINGFISH results to provide a comprehensive sample of mass models of disk galaxies inclusive of molecular gas. We compare the kinematics of the molecular (CO from HERACLES) and atomic (H i from THINGS) gas distributions to determine the extent to which CO may be used to probe the dynamics in the inner part of galaxies. In general, we find good agreement between the CO and H i kinematics, with small differences in the inner part of some galaxies. We add the contribution of the molecular gas to the mass models in our galaxies by using two different conversion factors αCO to convert CO luminosity to molecular gas mass surface density—the constant Milky Way value and the radially varying profiles determined in recent work based on THINGS, HERACLES, and KINGFISH data. We study the relative effect that the addition of the molecular gas has on the halo rotation curves for Navarro-Frenk-White and the observationally motivated pseudo-isothermal halos. The contribution of the molecular gas varies for galaxies in our sample—for those galaxies where there is a substantial molecular gas content, using different values of αCO can result in significant differences to the relative contribution of the molecular gas and hence the shape of the dark matter halo rotation curves in the central regions of galaxies.

  2. Impact of oil and gas infrastructure development in La Manga Canyon, NM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    La Manga Canyon is a small watershed (~20km2) in the San Juan Basin that has historically been developed for natural gas and recently for coal bed methane. Since gas production began in the 1940s, an extensive network of dirt roads have transected the watershed, providing access to well sites. There...

  3. Impact of Higher Natural Gas Prices on Local Distribution Companies and Residential Customers

    EIA Publications

    2007-01-01

    This report examines some of the problems faced by natural gas consumers as a result of increasing heating bills in recent years and problems associated with larger amounts of uncollectible revenue and lower throughput for the local distribution companies (LDCs) supplying the natural gas.

  4. 78 FR 19444 - Pawnee National Grassland, Colorado; Oil and Gas Leasing Analysis Environmental Impact Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-01

    ...; ] DEPARTMENT OF AGRICULTURE Forest Service Pawnee National Grassland, Colorado; Oil and Gas Leasing Analysis... Pawnee National Grassland Record of Decision (ROD) for the Revision of the Land and Resource Management Plan (LRMP), which included the Oil and Gas Leasing Analysis on the Pawnee National Grassland...

  5. Shale gas, wind and water: assessing the potential cumulative impacts of energy development on ecosystem services within the Marcellus play.

    PubMed

    Evans, Jeffrey S; Kiesecker, Joseph M

    2014-01-01

    Global demand for energy has increased by more than 50 percent in the last half-century, and a similar increase is projected by 2030. This demand will increasingly be met with alternative and unconventional energy sources. Development of these resources causes disturbances that strongly impact terrestrial and freshwater ecosystems. The Marcellus Shale gas play covers more than 160,934 km(2) in an area that provides drinking water for over 22 million people in several of the largest metropolitan areas in the United States (e.g. New York City, Washington DC, Philadelphia & Pittsburgh). Here we created probability surfaces representing development potential of wind and shale gas for portions of six states in the Central Appalachians. We used these predictions and published projections to model future energy build-out scenarios to quantify future potential impacts on surface drinking water. Our analysis predicts up to 106,004 new wells and 10,798 new wind turbines resulting up to 535,023 ha of impervious surface (3% of the study area) and upwards of 447,134 ha of impacted forest (2% of the study area). In light of this new energy future, mitigating the impacts of energy development will be one of the major challenges in the coming decades. PMID:24586599

  6. Shale Gas, Wind and Water: Assessing the Potential Cumulative Impacts of Energy Development on Ecosystem Services within the Marcellus Play

    PubMed Central

    Evans, Jeffrey S.; Kiesecker, Joseph M.

    2014-01-01

    Global demand for energy has increased by more than 50 percent in the last half-century, and a similar increase is projected by 2030. This demand will increasingly be met with alternative and unconventional energy sources. Development of these resources causes disturbances that strongly impact terrestrial and freshwater ecosystems. The Marcellus Shale gas play covers more than 160,934 km2 in an area that provides drinking water for over 22 million people in several of the largest metropolitan areas in the United States (e.g. New York City, Washington DC, Philadelphia & Pittsburgh). Here we created probability surfaces representing development potential of wind and shale gas for portions of six states in the Central Appalachians. We used these predictions and published projections to model future energy build-out scenarios to quantify future potential impacts on surface drinking water. Our analysis predicts up to 106,004 new wells and 10,798 new wind turbines resulting up to 535,023 ha of impervious surface (3% of the study area) and upwards of 447,134 ha of impacted forest (2% of the study area). In light of this new energy future, mitigating the impacts of energy development will be one of the major challenges in the coming decades. PMID:24586599

  7. Socioeconomic impacts of natural gas curtailments: a study of the textile industry in the southeastern United States. Final report

    SciTech Connect

    Jennings, D.M.

    1980-01-01

    A study was undertaken to identify the effects of fuel curtailments in the textile industry in North and South Carolina. Regional economic and social structures were affected with natural gas curtailments in 1976 and 1977. This document presents results of the effects of production shutdown resulting from the curtailments. Chapter II presents background information on the pipelines that service the region. Chapters III and IV describe the affected communities and the observed increase in government expenditures to counteract the impacts. Chapter V contains a complete list of textile plants in the study area that had to either work under abbreviated schedules or close entirely during the winter of 1976-1977. Attention was given to economic impacts at the industrial level that may have been attributable to the curtailment. Chapter VI covers these topics. In some instances, textile mills have relocated their plant facilities because they could not be guaranteed continuous fuel service at their original site. These data are the main concern of Chapter VII. Chapter VIII concentrates on social impacts; many facilities which provide services essential to human needs were subjected to gas curtailments so that the critical energy supplies could be diverted to industry. Chapter VIII also discusses an interesting geographic separation between social and economic impacts.

  8. Technological Change and Its Labor Impact in Five Energy Industries. Coal Mining/Oil and Gas Extraction/Petroleum Refining/Petroleum Pipeline Transportation/Electric and Gas Utilities.

    ERIC Educational Resources Information Center

    Bureau of Labor Statistics (DOL), Washington, DC.

    This bulletin appraises major technological changes emerging in five American industries (coal mining, oil and gas extraction, petroleum refining, petroleum pipeline transportation, and electric and gas utilities) and discusses the impact of these changes on productivity and occupations over the next five to ten years. Its separate reports on each…

  9. Impact of Shale Gas Development on Water Resource in Fuling, China

    NASA Astrophysics Data System (ADS)

    Yang, Hong; Huang, Xianjin; Yang, Qinyuan; Tu, Jianjun

    2015-04-01

    As a low-carbon energy, shale gas rapidly developed in U.S. in last years due to the innovation of the technique of hydraulic fracture, or fracking. Shale gas boom produces more gas with low price and reduced the reliance on fuel import. To follow the American shale gas success, China made an ambitious plan of shale gas extraction, 6.5 billion m3 by 2015. To extract shale gas, huge amount water is needed to inject into each gas well. This will intensify the competition of water use between industry, agricultural and domestic sectors. It may finally exacerbate the water scarcity in China. After the extraction, some water was returned to the ground. Without adequate treatment, the flowback water can introduce heavy metal, acids, pesticides, and other toxic material into water and land. This may inevitably worsen the water and land contamination. This study analysed the potential water consumption and wastewater generation in shale gas development in Fuling, Southwest China. The survey found the average water consumption is 30,000 cubic meter for one well, higher than shale well in U.S. Some 2%-20% water flowed back to the ground. The water quality monitoring showed the Total Suspended Solid (TSS) and Chemical Oxygen Demand (COD) were the main factors above those specified by China's water regulation. Shale gas is a lower-carbon energy, but it is important to recognize the water consuming and environmental pollution during the fracking. Strict monitoring and good coordination during the shale gas exploitation is urgently needed for the balance of economic development, energy demand and environmental protection.

  10. Natural Gas Variability In California: Environmental Impacts And Device Performance Combustion Modeling of Pollutant Emissions From a Residential Cooking Range

    SciTech Connect

    Tonse, S. R.; Singer, B. C.

    2011-07-01

    As part of a larger study of liquefied natural gas impacts on device performance and pollutant emissions for existing equipment in California, this report describes a cmoputer modeling study of a partially premixed flame issueing from a single cooktop burner port. The model consisted of a reactive computational fluid dynamics three-dimensional spatial grid and a 71-species chemical mechanism with propane combustion capability. Simulations were conducted with a simplified fuel mixture containing methane, ethane, and propane in proportions that yield properties similar to fuels distributed throughout much of California now and in recent years (baseline fuel), as well as with two variations of simulated liquefied natural gas blends. A variety of simulations were conducted with baseline fuel to explore the effect of several key parameters on pollutant formation and other flame characteristics. Simulations started with fuel and air issuing through the burner port, igniting, and continuing until the flame was steady with time. Conditions at this point were analyzed to understand fuel, secondary air and reaction product flows, regions of pollutant formation, and exhaust concentrations of carbon monoxide, nitric oxide and formaldehyde. A sensitivity study was conducted, varying the inflow parameters of this baseline gs about real-world operating conditions. Flame properties responded as expected from reactive flow theory. In the simulation, carbon monoxide levels were influenced more by the mixture's inflow velocity than by the gas-to-air ratio in the mixture issuing from the inflow port. Additional simulations were executed at two inflow conditions - high heat release and medium heat release - to examine the impact of replacing the baseline gas with two mixtures representative of liquefied natural gas. Flame properties and pollutant generation rates were very similar among the three fuel mixtures.

  11. Analysis of the Molecules Structure and Vertical Electron Affinity of Organic Gas Impact on Electric Strength

    NASA Astrophysics Data System (ADS)

    Jiao, Juntao; Xiao, Dengming; Zhao, Xiaoling; Deng, Yunkun

    2016-05-01

    It is necessary to find an efficient selection method to pre-analyze the gas electric strength from the perspective of molecule structure and the properties for finding the alternative gases to sulphur hexafluoride (SF6). As the properties of gas are determined by the gas molecule structure, the research on the relationship between the gas molecule structure and the electric strength can contribute to the gas pre-screening and new gas development. In this paper, we calculated the vertical electron affinity, molecule orbits distribution and orbits energy of gas molecules by the means of density functional theory (DFT) for the typical structures of organic gases and compared their electric strengths. By this method, we find part of the key properties of the molecule which are related to the electric strength, including the vertical electron affinity, the lowest unoccupied molecule orbit (LUMO) energy, molecule orbits distribution and negative-ion system energy. We also listed some molecule groups such as unsaturated carbons double bonds (C=C) and carbonitrile bonds (C≡N) which have high electric strength theoretically by this method. supported by National Natural Science Foundation of China (Nos. 51177101 and 51337006)

  12. A Study of the Impact of Variations on Aerodynamic Flow in Gas Turbine Engines via Monte-Carlo Simulations

    NASA Technical Reports Server (NTRS)

    Ngo, Khiem Viet; Tumer, Irem Y.

    2003-01-01

    The unsteady compressible inviscid flow is characterized by the conservations of mass, momentum, and energy; or simply the Euler equations. In this paper, a study of the subsonic one-dimensional Euler equations with local preconditioning is presented with a modal analysis approach. Specifically, this study investigates the behavior of airflow in a gas turbine engine using the specified conditions at the inflow and outflow boundaries of the compressor, combustion chamber, and turbine, under the impact of variations in pressure, velocity, temperature, and density at low Mach numbers. Two main questions that motivate this research are: 1) Is there any aerodynamic problem with the existing gas turbine engines that could impact aircraft performance? 2) If yes, what aspect of a gas turbine engine could be improved via design to alleviate that impact and to optimize aircraft performance. This paper presents an initial attempt to the flow behavior in terms (perturbation) using simulation outputs from a customer-deck model obtained from Pratt&Whitney, (i.e., pressure, temperature, velocity, density) about their mean states at the inflow and outflow boundaries of the compressor, combustion chamber, and turbine. Flow behavior is analyzed for the high pressure compressor and combustion chamber employing the conditions on their left and right boundaries. In the same fashion, similar analyses are carried out for the high and low-pressure turbines. In each case, the eigenfrequencies that are obtained for different boundary conditions are examined closely based on their probabilistic distributions, a result of a Monte Carlo 10,000-sample simulation. Furthermore, the characteristic waves and eave response are analyzed and contrasted among different cases, with and without preconditioners. The results reveal the existence of flow instabilities due to the combined effect of variations and excessive pressures; which are clearly the case in the combustion chamber and high

  13. Application of nonparametric regression and statistical testing to identify the impact of oil and natural gas development on local air quality

    SciTech Connect

    Pekney, Natalie J.; Cheng, Hanqi; Small, Mitchell J.

    2015-11-05

    Abstract: The objective of the current work was to develop a statistical method and associated tool to evaluate the impact of oil and natural gas exploration and production activities on local air quality.

  14. Impacts of Oil and Gas Production on Winter Ozone Pollution in the Uintah Basin Using Model Source Apportionment

    NASA Astrophysics Data System (ADS)

    Tran, H. N. Q.; Tran, T. T.; Mansfield, M. L.; Lyman, S. N.

    2014-12-01

    Contributions of emissions from oil and gas activities to elevated ozone concentrations in the Uintah Basin - Utah were evaluated using the CMAQ Integrated Source Apportionment Method (CMAQ-ISAM) technique, and were compared with the results of traditional budgeting methods. Unlike the traditional budgeting method, which compares simulations with and without emissions of the source(s) in question to quantify its impacts, the CMAQ-ISAM technique assigns tags to emissions of each source and tracks their evolution through physical and chemical processes to quantify the final ozone product yield from the source. Model simulations were performed for two episodes in winter 2013 of low and high ozone to provide better understanding of source contributions under different weather conditions. Due to the highly nonlinear ozone chemistry, results obtained from the two methods differed significantly. The growing oil and gas industry in the Uintah Basin is the largest contributor to the elevated zone (>75 ppb) observed in the Basin. This study therefore provides an insight into the impact of oil and gas industry on the ozone issue, and helps in determining effective control strategies.

  15. Contributions of gas flaring to a global air pollution hotspot: Spatial and temporal variations, impacts and alleviation

    NASA Astrophysics Data System (ADS)

    Anejionu, Obinna C. D.; Whyatt, J. Duncan; Blackburn, G. Alan; Price, Catheryn S.

    2015-10-01

    Studies of environmental impacts of gas flaring in the Niger Delta are hindered by limited access to official flaring emissions records and a paucity of reliable ambient monitoring data. This study uses a combination of geospatial technologies and dispersion modelling techniques to evaluate air pollution impacts of gas flaring on human health and natural ecosystems in the region. Results indicate that gas flaring is a major contributor to air pollution across the region, with concentrations exceeding WHO limits in some locations over certain time periods. Due to the predominant south-westerly wind, concentrations are higher in some states with little flaring activity than in others with significant flaring activity. Twenty million people inhabit areas of high flare-associated air pollution, which include all of the main ecological zones of the region, indicating that flaring poses a substantial threat to human health and the environment. Model scenarios demonstrated that substantial reductions in pollution could be achieved by stopping flaring at a small number of the most active sites and by improving overall flaring efficiency.

  16. Impact of the waves on the product flux of the Iguasu gas centrifuge

    NASA Astrophysics Data System (ADS)

    Bogovalov, S. V.; Kislov, V. A.; Tronin, I. V.

    2016-06-01

    2D axisymmetric transient flow induced by a pulsed braking force in the Iguasu gas centrifuge is simulated numerically. The simulation is performed for two cases: transient and stationary. The braking forces averaged over the period of rotation are equal to each other in both cases. The transient case is compared with the stationary case where the flow is excited by the stationary braking force. In the transient case the gas flux through the gap in the bottom baffle exceeds on 15 % the same flux in the stationary case for the same gas content and temperature at the walls of the rotor. We argue that the waves can reduce the gas content in the GC on the same 15 %.

  17. The impact of fluid advection on gas hydrate stability: Investigations at sites of methane seepage offshore Costa Rica

    NASA Astrophysics Data System (ADS)

    Crutchley, G. J.; Klaeschen, D.; Planert, L.; Bialas, J.; Berndt, C.; Papenberg, C.; Hensen, C.; Hornbach, M. J.; Krastel, S.; Brueckmann, W.

    2014-09-01

    Fluid flow through marine sediments drives a wide range of processes, from gas hydrate formation and dissociation, to seafloor methane seepage including the development of chemosynthetic ecosystems, and ocean acidification. Here, we present new seismic data that reveal the 3D nature of focused fluid flow beneath two mound structures on the seafloor offshore Costa Rica. These mounds have formed as a result of ongoing seepage of methane-rich fluids. We show the spatial impact of advective heat flow on gas hydrate stability due to the channelled ascent of warm fluids towards the seafloor. The base of gas hydrate stability (BGHS) imaged in the seismic data constrains peak heat flow values to ∼60 mW m and ∼70 mW m beneath two separate seep sites known as Mound 11 and Mound 12, respectively. The initiation of pronounced fluid flow towards these structures was likely controlled by fault networks that acted as efficient pathways for warm fluids ascending from depth. Through the gas hydrate stability zone, fluid flow has been focused through vertical conduits that we suggest developed as migrating fluids generated their own secondary permeability by fracturing strata as they forced their way upwards towards the seafloor. We show that Mound 11 and Mound 12 (about 1 km apart on the seafloor) are sustained by independent fluid flow systems through the hydrate system, and that fluid flow rates across the BGHS are probably similar beneath both mounds. 2D seismic data suggest that these two flow systems might merge at approximately 1 km depth, i.e. much deeper than the BGHS. This study provides a new level of detail and understanding of how channelled, anomalously-high fluid flow towards the seafloor influences gas hydrate stability. Thus, gas hydrate systems have good potential for quantifying the upward flow of subduction system fluids to seafloor seep sites, since the fluids have to interact with and leave their mark on the hydrate system before reaching the seafloor.

  18. CO2 utilization and storage in shale gas reservoirs: Experimental results and economic impacts

    DOE PAGESBeta

    Schaef, Herbert T.; Davidson, Casie L.; Owen, Antionette Toni; Miller, Quin R. S.; Loring, John S.; Thompson, Christopher J.; Bacon, Diana H.; Glezakou, Vassiliki Alexandra; McGrail, B. Peter

    2014-12-31

    Natural gas is considered a cleaner and lower-emission fuel than coal, and its high abundance from advanced drilling techniques has positioned natural gas as a major alternative energy source for the U.S. However, each ton of CO2 emitted from any type of fossil fuel combustion will continue to increase global atmospheric concentrations. One unique approach to reducing anthropogenic CO2 emissions involves coupling CO2 based enhanced gas recovery (EGR) operations in depleted shale gas reservoirs with long-term CO2 storage operations. In this paper, we report unique findings about the interactions between important shale minerals and sorbing gases (CH4 and CO2) andmore » associated economic consequences. Where enhanced condensation of CO2 followed by desorption on clay surface is observed under supercritical conditions, a linear sorption profile emerges for CH4. Volumetric changes to montmorillonites occur during exposure to CO2. Theory-based simulations identify interactions with interlayer cations as energetically favorable for CO2 intercalation. Thus, experimental evidence suggests CH4 does not occupy the interlayer and has only the propensity for surface adsorption. Mixed CH4:CO2 gas systems, where CH4 concentrations prevail, indicate preferential CO2 sorption as determined by in situ infrared spectroscopy and X-ray diffraction techniques. Collectively, these laboratory studies combined with a cost-based economic analysis provide a basis for identifying favorable CO2-EOR opportunities in previously fractured shale gas reservoirs approaching final stages of primary gas production. Moreover, utilization of site-specific laboratory measurements in reservoir simulators provides insight into optimum injection strategies for maximizing CH4/CO2 exchange rates to obtain peak natural gas production.« less

  19. Impact of Fuel Interchangeability on dynamic Instabilities in Gas Turbine Engines

    SciTech Connect

    Ferguson, D.H.; Straub, D.L.; Richards, G.A.; Robey, E.H.

    2007-03-01

    Modern, low NOx emitting gas turbines typically utilize lean pre-mixed (LPM) combustion as a means of achieving target emissions goals. As stable combustion in LPM systems is somewhat intolerant to changes in operating conditions, precise engine tuning on a prescribed range of fuel properties is commonly performed to avoid dynamic instabilities. This has raised concerns regarding the use of imported liquefied natural gas (LNG) and natural gas liquids (NGL’s) to offset a reduction in the domestic natural gas supply, which when introduced into the pipeline could alter the fuel BTU content and subsequently exacerbate problems such as combustion instabilities. The intent of this study is to investigate the sensitivity of dynamically unstable test rigs to changes in fuel composition and heat content. Fuel Wobbe number was controlled by blending methane and natural gas with various amounts of ethane, propane and nitrogen. Changes in combustion instabilities were observed, in both atmospheric and pressurized test rigs, for fuels containing high concentrations of propane (> 62% by vol). However, pressure oscillations measured while operating on typical “LNG like” fuels did not appear to deviate significantly from natural gas and methane flame responses. Mechanisms thought to produce changes in the dynamic response are discussed.

  20. The Impact of Water Regulation on the Availability of Shale Gas Resources for Production

    NASA Astrophysics Data System (ADS)

    Victor, D. G.

    2011-12-01

    Visions for a large increase in North American production of natural gas from shale are based heavily on the sharp rise in the estimated available resource. Those estimates are prepared by looking at the underlying geology as well as the cost and availability of technologies for extracting gas. We add to that equation the potential current and future regulation of water injection (subsurface) and runoff (surface). Using the political science theory of "veto points" we show that US water legislation is organized in ways that allow for large numbers of political forces to block (or make costly) access to gas resources. By our estimate, 26% of the shale gas resource will be unavailable-a fraction that could rise if there are strong contagion effects as jurisdictions that have traditionally had industry-friendly regulatory systems apply much stricter rules. This work has potentially large implications for visions of the new natural gas revolution and the price of North American (and potentially world) natural gas.

  1. Possibility of production of amino acids by impact reaction using a light-gas gun as a simulation of asteroid impacts.

    PubMed

    Okochi, Kazuki; Mieno, Tetsu; Kondo, Kazuhiko; Hasegawa, Sunao; Kurosawa, Kosuke

    2015-06-01

    In order to investigate impact production of carbonaceous products by asteroids on Titan and other satellites and planets, simulation experiments were carried out using a 2-stage light gas gun. A small polycarbonate or metal bullet with about 6.5 km/s was injected into a pressurized target chamber filled with 1 atm of nitrogen gas, to collide with a ice + iron target or an iron target or a ice + hexane + iron target. After the impact, black soot including fine particles was deposited on the chamber wall. The soot was carefully collected and analyzed by High Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Laser Desorption Time-of-Flight Mass Spectrometry (LD-ToF-MS). As a result of the HPLC analysis, about 0.04-8 pmol of glycine, and a lesser amount of alanine were found in the samples when the ice + hexane + iron target was used. In case of the ice + iron target and the iron target, less amino acids were produced. The identification of the amino acids was also supported by FTIR and LD-ToF-MS analysis. PMID:25796389

  2. Possibility of Production of Amino Acids by Impact Reaction Using a Light-Gas Gun as a Simulation of Asteroid Impacts

    NASA Astrophysics Data System (ADS)

    Okochi, Kazuki; Mieno, Tetsu; Kondo, Kazuhiko; Hasegawa, Sunao; Kurosawa, Kosuke

    2015-06-01

    In order to investigate impact production of carbonaceous products by asteroids on Titan and other satellites and planets, simulation experiments were carried out using a 2-stage light gas gun. A small polycarbonate or metal bullet with about 6.5 km/s was injected into a pressurized target chamber filled with 1 atm of nitrogen gas, to collide with a ice + iron target or an iron target or a ice + hexane + iron target. After the impact, black soot including fine particles was deposited on the chamber wall. The soot was carefully collected and analyzed by High Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Laser Desorption Time-of-Flight Mass Spectrometry (LD-ToF-MS). As a result of the HPLC analysis, about 0.04-8 pmol of glycine, and a lesser amount of alanine were found in the samples when the ice + hexane + iron target was used. In case of the ice + iron target and the iron target, less amino acids were produced. The identification of the amino acids was also supported by FTIR and LD-ToF-MS analysis.

  3. Impact of AGN and stellar feedback on the gas of a simulated z~2 star-forming galaxy

    NASA Astrophysics Data System (ADS)

    Roos, Orianne; Bournaud, Frédéric; Juneau, Stephanie; Gabor, Jared

    2015-08-01

    With high-resolution simulations of star-forming disk galaxies at high redshift, we study the effects of combined AGN and stellar feedback models on the gas of the host-galaxy. AGN feedback is modeled using a standard thermal recipe of feedback (gas is heated and pushed away) plus a post-processing method to compute AGN ionization. We first consider AGN feedback only and show that, even though the AGN generates powerful outflows, the effects of AGN feedback on star formation is relatively weak on time-scales up to a few 100s of Myrs, even when long-range radiative feedback is accounted for. Furthermore, as the combination of stellar feedback models generates outflows that are more powerful than the sum of the models taken separately, we check whether combined AGN and stellar feedback also couple non-linearly. We then include several stellar feedback sources on top of AGN feedback, such as young stars creating HII regions through radiative pressure and supernovae releasing thermal and kinetic energy in the ISM. We follow their impact on the gas of high-resolution simulations and study the coupling between the different sources of outflows (AGN, young stars, supernovae) , which could produce very fast outflows, with important outflow rates. How do these feedback-driven winds affect the host? What is the amount of expelled gas? What is its density and temperature and what is the consequence for in place and future star formation? Can such outflows change the distribution of existing stars?

  4. Greenhouse gas emission impacts of electric vehicles under varying driving cycles in various counties and US cities

    SciTech Connect

    Wang, M.Q.; Marr, W.W.

    1994-02-10

    Electric vehicles (EVs) can reduce greenhouse gas emissions, relative to emissions from gasoline-fueled vehicles. However, those studies have not considered all aspects that determine greenhouse gas emissions from both gasoline vehicles (GVs) and EVs. Aspects often overlooked include variations in vehicle trip characteristics, inclusion of all greenhouse gases, and vehicle total fuel cycle. In this paper, we estimate greenhouse gas emission reductions for EVs, including these important aspects. We select four US cities (Boston, Chicago, Los Angeles, and Washington, D.C.) and six countries (Australia, France, Japan, Norway, the United Kingdom, and the United States) and analyze greenhouse emission impacts of EVs in each city or country. We also select six driving cycles developed around the world (i.e., the US federal urban driving cycle, the Economic Community of Europe cycle 15, the Japanese 10-mode cycle, the Los Angeles 92 cycle, the New York City cycle, and the Sydney cycle). Note that we have not analyzed EVs in high-speed driving (e.g., highway driving), where the results would be less favorable to EVs; here, EVs are regarded as urban vehicles only. We choose one specific driving cycle for a given city or country and estimate the energy consumption of four-passenger compact electric and gasoline cars in the given city or country. Finally, we estimate total fuel cycle greenhouse gas emissions of both GVs and EVs by accounting for emissions from primary energy recovery, transportation, and processing; energy product transportation; and powerplant and vehicle operations.

  5. Impacts of Urban Water Conservation Strategies on Energy, Greenhouse Gas Emissions, and Health: Southern California as a Case Study

    PubMed Central

    Sokolow, Sharona; Godwin, Hilary

    2016-01-01

    Objectives. To determine how urban water conservation strategies in California cities can affect water and energy conservation efforts, reduce greenhouse gas emissions, and benefit public health. Methods. We expanded upon our 2014 health impact assessment of California's urban water conservation strategies by comparing the status quo to 2 options with the greatest potential impact on the interrelated issues of water and energy in California: (1) banning landscape irrigation and (2) expanding alternative water sources (e.g., desalination, recycled water). Results. Among the water conservation strategies evaluated, expanded use of recycled water stood out as the water conservation strategy with potential to reduce water use, energy use, and greenhouse gas emissions, with relatively small negative impacts for the public’s health. Conclusions. Although the suitability of recycled water for urban uses depends on local climate, geography, current infrastructure, and finances, analyses similar to that presented here can help guide water policy decisions in cities across the globe facing challenges of supplying clean, sustainable water to urban populations. PMID:26985606

  6. Results of Two-Stage Light-Gas Gun Development Efforts and Hypervelocity Impact Tests of Advanced Thermal Protection Materials

    NASA Technical Reports Server (NTRS)

    Cornelison, C. J.; Watts, Eric T.

    1998-01-01

    Gun development efforts to increase the launching capabilities of the NASA Ames 0.5-inch two-stage light-gas gun have been investigated. A gun performance simulation code was used to guide initial parametric variations and hardware modifications, in order to increase the projectile impact velocity capability to 8 km/s, while maintaining acceptable levels of gun barrel erosion and gun component stresses. Concurrent with this facility development effort, a hypervelocity impact testing series in support of the X-33/RLV program was performed in collaboration with Rockwell International. Specifically, advanced thermal protection system materials were impacted with aluminum spheres to simulate impacts with on-orbit space debris. Materials tested included AETB-8, AETB-12, AETB-20, and SIRCA-25 tiles, tailorable advanced blanket insulation (TABI), and high temperature AFRSI (HTA). The ballistic limit for several Thermal Protection System (TPS) configurations was investigated to determine particle sizes which cause threshold TPS/structure penetration. Crater depth in tiles was measured as a function of impact particle size. The relationship between coating type and crater morphology was also explored. Data obtained during this test series was used to perform a preliminary analysis of the risks to a typical orbital vehicle from the meteoroid and space debris environment.

  7. Identification of nitroaromatics in diesel exhaust particulate using gas chromatography/negative ion chemical ionization mass spectrometry and other techniques

    SciTech Connect

    Newton, D.L.; Erickson, M.D.; Tomer, K.B.; Pellizzari, E.D.; Gentry, P.

    1982-04-01

    A series of nitroaromatic compounds were identified in diesel exhaust particulate extract. Isomers of nitroanthracene (and/or nitrophenanthrene) and nitropyrene (and/or nitrofluoranthene) were unequivocally identified. Alkyl homologues of nitroanthracene through C/sub 3/-alkyl-nitroanthracene were tentatively identified. In addition, a C/sub 18/H/sub 11/NO/sub 2/ isomer was tentatively identified. The nitro-substituted polynuclear aromatic hydrocarbons (PAHs) were found in two fractions of diesel exhaust particulate extract collected from a low-pressure liquid chromatography (LPLC) column. One of the two fractions containing nitroaromatic constitutents accounted for a large percentage of the mutagenicity of the crude particulate extract. Initial identification were made by using high-resolution gas chromatography/electron impact mass spectrometry/computer (GC/EIMS) and negative ion chemical ionization mass specrometry/computer (GC/NICIMS). These identifications were confirmed by direct probe high-resolution mass spectrometry (HRMS) and gas chromatography/Fourier transform infrared spectrometry (GC/FT IR). The relative merit of each analytical technique for the determination of nitroaromatics is discussed with emphasis on the usefulness of GC/NICIMS as a means of analyzing for nitro-substituted PAHs.

  8. Analysis of the impact of the use of broad specification fuels on combustors for commercial aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Lehmann, R. P.; Smith, A. L.

    1979-01-01

    An analytical study was conducted to assess the impact of the use of broad specification fuels with reduced hydrogen content on the design, performance, durability, emissions and operational characteristics of combustors for commercial aircraft gas turbine engines. The study was directed at defining necessary design revisions to combustors designed for use of Jet A when such are operated on ERBS (Experimental Referee Broad Specification Fuel) which has a nominal hydrogen content of 12.8 percent as opposed to 13.7 percent in current Jet A. The results indicate that improvements in combustor liner cooling, and/or materials, and methods of fuel atomization will be required if the hydrogen content of aircraft gas turbine fuel is decreased.

  9. The impact of the Sarbanes Oxley Act on auditing fees: An empirical study of the oil and gas industry

    NASA Astrophysics Data System (ADS)

    Ezelle, Ralph Wayne, Jr.

    2011-12-01

    This study examines auditing of energy firms prior and post Sarbanes Oxley Act of 2002. The research explores factors impacting the asset adjusted audit fee of oil and gas companies and specifically examines the effect of the Sarbanes Oxley Act. This research analyzes multiple year audit fees of the firms engaged in the oil and gas industry. Pooled samples were created to improve statistical power with sample sizes sufficient to test for medium and large effect size. The Sarbanes Oxley Act significantly increases a firm's asset adjusted audit fees. Additional findings are that part of the variance in audit fees was attributable to the market value of the enterprise, the number of subsidiaries, the receivables and inventory, debt ratio, non-profitability, and receipt of a going concern report.

  10. AIR QUALITY IMPACTS OF LIQUEFIED NATURAL GAS IN THE SOUTH COAST AIR BASIN OF CALIFORNIA

    SciTech Connect

    Carerras-Sospedra, Marc; Brouwer, Jack; Dabdub, Donald; Lunden, Melissa; Singer, Brett

    2011-07-01

    The effects of liquefied natural gas (LNG) on pollutant emission inventories and air quality in the South Coast Air Basin of California were evaluated using recent LNG emission measurements by Lawrence Berkeley National Laboratory and the Southern California Gas Company (SoCalGas), and with a state-of-the-art air quality model. Pollutant emissions can be affected by LNG owing to differences in composition and physical properties, including the Wobbe index, a measure of energy delivery rate. This analysis uses LNG distribution scenarios developed by modeling Southern California gas flows, including supplies from the LNG receiving terminal in Baja California, Mexico. Based on these scenarios, the projected penetratino of LNG in the South Coast Air Basin is expected to be limited. In addition, the increased Wobbe index of delivered gas (resulting from mixtures of LNG and conventional gas supplies) is expected to cause increases smaller than 0.05 percent in overall (area-wide) emissions of nitrogen oxides (NOx). BAsed on the photochemical state of the South Coast Air Basin, any increase in NOx is expected to cause an increase in the highest local ozone concentrations, and this is reflected in model results. However, the magnitude of the increase is well below the generally accepted accuracy of the model and would not be discernible with the existing monitoring network. Modeling of hypothetical scenarios indicates that discernible changes to ambient ozone and particulate matter concentrations would occur only at LNG distribution rates that are not achievable with current or planned infrastructure and with Wobbe index vlaues that exceed current gas quality tariffs. Results of these hypothetical scenarios are presented for consideration of any proposed substantial expansion of LNG supply infrastructure in Southern California.

  11. PAH sorption mechanism and partitioning behavior in lampblack-impacted soils from former oil-gas plant sites.

    PubMed

    Hong, Lei; Ghosh, Upal; Mahajan, Tania; Zare, Richard N; Luthy, Richard G

    2003-08-15

    This study assessed polycyclic aromatic hydrocarbon (PAH) association and aqueous partitioning in lampblack-impacted field soils from five sites in California that formerly housed oil-gas process operations. Lampblack is the solid residue resulting from the decomposition of crude oil at high temperatures in the gas-making operation and is coated or impregnated with oil gasification byproducts, among which PAHs are the compounds of the greatest regulatory concern. A suite of complementary measurements investigated the character of lampblack particles and PAH location and the associated effects on PAH partitioning between lampblack and water. PAH analyses on both whole samples and density-separated components demonstrated that 81-100% of PAHs in the lampblack-impacted soils was associated with lampblack particles. FTIR, 13C NMR, and SEM analyses showed that oil-gas lampblack solids comprise primarily aromatic carbon with soot-like structures. A free-phase aromatic oil may be present in some of the lampblack soils containing high PAH concentrations. Comparable long-term aqueous partitioning measurements were obtained with an air-bridge technique and with a centrifugation/alum flocculation procedure. Large solid/water partition coefficient (Kd) values were observed in samples exhibiting lower PAH and oil levels, whereas smaller Kd values were measured in lampblack samples containing high PAH levels. The former result is in agreement with an oil-soot partitioning model, and the latter is in agreement with a coal tar-water partitioning model. Lampblack containing high PAH levels appears to exhaust the sorption capacity of the soot-carbon, creating a free aromatic oil phase that exhibits partitioning behavior similar to PAHs in coal tar. This study improves mechanistic understanding of PAH sorption on aged lampblack residuals at former oil-gas sites and provides a framework for mechanistic assessment of PAH leaching potential and risk from such site materials. PMID

  12. Bering Sea summary report: Outer Continental Shelf oil and gas activities in the Bering Sea and their onshore impacts

    SciTech Connect

    Deis, J.; Pierson, R.; Kurz, F.

    1983-09-01

    Two federal offshore oil-and-gas lease sales have been held in the Bering Sea Subregion. Lease Sale 57, Norton Basin, was held on March 15, 1983. Lease Sale 70, St. George Basin, was held on April 12, 1983. The sale offered 479 tracts, of which 97 received bids. The Department of the Interior has indicated that it will accept 96 of the 97 high bids; however, to date, leases have not been awarded. The Department of the Interior was enjoined from issuing leases by the US District Court of Alaska because of possible impacts from postlease preliminary seismic activities on gray and right whales. In accordance with the Court's ruling, leases cannot be issued until the completion of a supplemental environmental impact statement, which is anticipated to occur in November 1983. Six lease offerings in the Bering Sea Subregion are scheduled through 1987. Six deep stratigraphic test wells are the only wells drilled to date in the Bering Sea Subregion. To date, oil companies have not submitted exploration plans for the Norton Basin Planning Area. Exploration in Norton Basin could begin in the summer of 1984, at the earliest. Exploration plans cannot be submitted for the St. George Basin Planning Area until the leases are awarded. At this time, various onshore areas are being considered as possible support bases for offshore oil-and-gas exploration. At this stage, before exploratory drilling has occurred and in the absence of a commercial discovery, plans for transporting petroleum from the Bering Sea to markets in the United States are unclear. The current estimates of risked resources for lands leased in Lease Sale 57, Norton Basin, are 33 million barrels of oil and 110 billion cubic feet of gas. Lease Sale 70, St. George Basin, estimates of risked resources for leased lands are 27 million barrels of oil and 310 billion cubic feet of gas. 55 references, 10 figures, 3 tables.

  13. Impact of Chlorine Dioxide Gas Sterilization on Nosocomial Organism Viability in a Hospital Room

    PubMed Central

    Lowe, John J.; Gibbs, Shawn G.; Iwen, Peter C.; Smith, Philip W.; Hewlett, Angela L.

    2013-01-01

    To evaluate the ability of ClO2 to decontaminate pathogens known to cause healthcare-associated infections in a hospital room strains of Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis, Mycobacterium smegmatis, and Staphylococcus aureus were spot placed in duplicate pairs at 10 sites throughout a hospital room and then exposed to ClO2 gas. Organisms were collected and evaluated for reduction in colony forming units following gas exposure. Six sterilization cycles with varied gas concentrations, exposure limits, and relative humidity levels were conducted. Reductions in viable organisms achieved ranged from 7 to 10-log reductions. Two sterilization cycles failed to produce complete inactivation of organisms placed in a bathroom with the door closed. Reductions of organisms in the bathroom ranged from 6-log to 10-log reductions. Gas leakage between hospital floors did not occur; however, some minor gas leakage from the door of hospital room was measured which was subsequently sealed to prevent further leakage. Novel technologies for disinfection of hospital rooms require validation and safety testing in clinical environments. Gaseous ClO2 is effective for sterilizing environmental contamination in a hospital room. Concentrations of ClO2 up to 385 ppm were safely maintained in a hospital room with enhanced environmental controls. PMID:23792697

  14. [Impact of introduction of O2 on the welding arc of gas pool coupled activating TIG].

    PubMed

    Huang, Yong; Wang, Yan-Lei; Zhang, Zhi-Guo

    2014-05-01

    In the present paper, Boltzmann plot method was applied to analyze the temperature distributions of the are plasma when the gas pool coupled activating TIG welding was at different coupling degrees with the outer gas being O2. Based on this study of temperature distributions, the changing regularities of are voltage and are appearance were studied. The result shows that compared with traditional TIG welding, the introduction of O2 makes the welding arc constricted slightly, the temperature of the are center build up, and the are voltage increase. When argon being the inner gas, oxygen serving as the outer gas instead of argon makes the are constricted more obviously. When the coupling degree increases from 0 to 2, the temperature of the are center and the are voltage both increase slightly. In the gas pool coupled activating TIG welding the are is constricted not obviously, and the reason why the weld penetration is improved dramatically in the welding of stainless steel is not are constriction. PMID:25095400

  15. Regional Air Quality Impacts of Hydraulic Fracturing and Natural Gas Activity: Evidence from Ambient VOC Observations

    NASA Astrophysics Data System (ADS)

    Vinciguerra, T.; Ehrman, S.; Yao, S.; Dadzie, J.; Chittams, A.; Dickerson, R. R.

    2014-12-01

    Over the past decade, many anthropogenic pollutants have been successfully reduced, providing improved air quality. However, a new influx of emissions associated with hydraulic fracturing and natural gas operations could be counteracting some of these benefits. Using hourly measurements from Photochemical Assessment Monitoring Stations (PAMS) in the Baltimore, MD and Washington, D.C. areas, we observed that following a period of decline, daytime ethane concentrations have increased significantly since 2010. This trend appears to be linked with the rapid natural gas production in upwind, neighboring states, especially Pennsylvania and West Virginia. Furthermore, ethane concentrations failed to display this trend at a PAMS site outside of Atlanta, GA, a region without widespread natural gas operations. Year-to-year changes in VOCs were further evaluated by using Positive Matrix Factorization (PMF) to perform source apportionment on hourly observations in Essex, MD from 2005-2013. This process takes ambient measurements and attributes them to sources such as biogenic, natural gas, industrial, gasoline, and vehicle exhaust by using tracer species as identifiers. Preliminary PMF results also indicate an increasing influence of natural gas sources for this area.

  16. Resolving flows around black holes: the impact of gas angular momentum

    NASA Astrophysics Data System (ADS)

    Curtis, Michael; Sijacki, Debora

    2016-08-01

    Cosmological simulations almost invariably estimate the accretion of gas onto supermassive black holes using a Bondi-Hoyle-like prescription. Doing so ignores the effects of the angular momentum of the gas, which may prevent or significantly delay accreting material falling directly onto the black hole. We outline a black hole accretion rate prescription using a modified Bondi-Hoyle formulation that takes into account the angular momentum of the surrounding gas. Meaningful implementation of this modified Bondi-Hoyle formulation is only possible when the inner vorticity distribution is well resolved, which we achieve through the use of a super-Lagrangian refinement technique around black holes within our simulations. We then investigate the effects on black hole growth by performing simulations of isolated as well as merging disc galaxies using the moving-mesh code AREPO. We find that the gas angular momentum barrier can play an important role in limiting the growth of black holes, leading also to a several Gyr delay between the starburst and the quasar phase in major merger remnants. We stress, however, that the magnitude of this effect is highly sensitive to the thermodynamical state of the accreting gas and to the nature of the black hole feedback present.

  17. Multiscale study of bacterial growth: Experiments and model to understand the impact of gas exchange on global growth

    NASA Astrophysics Data System (ADS)

    Lalanne-Aulet, David; Piacentini, Adalberto; Guillot, Pierre; Marchal, Philippe; Moreau, Gilles; Colin, Annie

    2015-11-01

    Using a millifluidics and macroscale setup, we study quantitatively the impact of gas exchange on bacterial growth. In millifluidic environments, the permeability of the incubator materials allows an unlimited oxygen supply by diffusion. Moreover, the efficiency of diffusion at small scales makes the supply instantaneous in comparison with the cell division time. In hermetic closed vials, the amount of available oxygen is low. The growth curve has the same trend but is quantitatively different from the millifluidic situation. The analysis of all the data allows us to write a quantitative modeling enabling us to capture the entire growth process.

  18. Impact of gas flow rate on breakdown of filamentary dielectric barrier discharges

    NASA Astrophysics Data System (ADS)

    Höft, H.; Becker, M. M.; Kettlitz, M.

    2016-03-01

    The influence of gas flow rate on breakdown properties and stability of pulsed dielectric barrier discharges (DBDs) in a single filament arrangement using a gas mixture of 0.1 vol. % O2 in N2 at atmospheric pressure was investigated by means of electrical and optical diagnostics, accompanied by fluid dynamics and electrostatics simulations. A higher flow rate perpendicular to the electrode symmetry axis resulted in an increased breakdown voltage and DBD current maximum, a higher discharge inception jitter, and a larger emission diameter of the discharge channel. In addition, a shift of the filament position for low gas flow rates with respect to the electrode symmetry axis was observed. These effects can be explained by the change of the residence time of charge carriers in the discharge region—i.e., the volume pre-ionization—for changed flow conditions due to the convective transport of particles out of the center of the gap.

  19. Impact of mine wastewaters on greenhouse gas emissions from northern peatlands used for mine water treatment

    NASA Astrophysics Data System (ADS)

    Palmer, Katharina; Ronkanen, Anna-Kaisa; Klöve, Björn; Hynynen, Jenna; Maljanen, Marja

    2015-04-01

    (iv) CH4 emissions are negatively correlated with NO3- and SO42- concentrations. This study thus illustrates the pronounced impacts of mine wastewaters on processes involved in greenhouse gas turnover in peatlands ecosystems.

  20. Urban leakage of liquefied petroleum gas and its impact on Mexico City air quality

    SciTech Connect

    Blake, D.R.; Rowland, F.S.

    1995-08-18

    Alkane hydrocarbons (propane, isobutane, and n-butane) from liquefied petroleum gas (LPG) are present in major quantities throughout Mexico City air because of leakage of the unburned gas from numerous urban sources. These hydrocarbons, together with olefinic minor LPG components, furnish substantial amounts of hydroxyl radical reactivity, a major precursor to formation of the ozone component of urban smog. The combined processes of unburned leakage and incomplete combustion of LPG play significant role in causing the excessive ozone characteristic of Mexico City. Reductions in ozone levels should be possible through changes in LPG composition and lowered rates of leakage. 23 refs., 3 tabs.

  1. Information highway: Alliances and their impact on the gas industry. Topical report, November 1993

    SciTech Connect

    Davis, K.W.

    1993-11-01

    The report describes the major developments in digital information networks, the key industry players and their alliances and technologies, and the significance of their activities to the gas industry. The newly-integrated industries involved in creating the 'information highway' are likely to promote standards based on open protocols and accelerate the pace of technology implementation in new products that link home systems and external network systems. Research was conducted using primary and secondary sources, on-line databases, and documentary research. Factors leading to the development of a new communications infrastructure and the alliances driving it were analyzed in order to best define opportunities and interests for the gas industry.

  2. Impact of Gas Delivery Systems on Imaging Studies of Human Cerebral Blood Flow

    PubMed Central

    Cain, John R.; Parkes, Laura M.; Eadsforth, Peter; Beards, Susan C.; Jackson, Alan

    2013-01-01

    Purpose. To compare a semiopen breathing circuit with a non-rebreathing (Hudson mask) for MRI experiments involving gas delivery. Methods and Materials. Cerebral blood flow (CBF) was measured by quantitative phase contrast angiography of the internal carotid and basilar arteries in 18 volunteers (20–31 years). In 8 subjects, gases were delivered via a standard non-rebreathing (Hudson mask). In 10 subjects, gases were delivered using a modified “Mapleson A” semiopen anesthetic gas circuit and mouthpiece. All subjects were given 100% O2, medical air, and carbogen gas (95% O2 and 5% CO2) delivered at 15 L/min in a random order. Results. The Hudson mask group showed significant increases in CBF in response to increased FiCO2 compared to air (+9.8%). A small nonsignificant reduction in CBF (−2.4%) was seen in response to increased inspired concentrations of oxygen (FiO2). The Mapleson A group showed significantly larger changes in CBF in response to both increased inspired concentrations of carbon dioxide (FiCO2) (+32.2%, P < 0.05) and FiO2 (−14.6%, P < 0.01). Conclusions. The use of an anaesthetic gas delivery circuit avoids entrainment of room air and rebreathing effects that may otherwise adversely affect the experimental results. PMID:24392225

  3. Impact of gas delivery systems on imaging studies of human cerebral blood flow.

    PubMed

    Cain, John R; Parkes, Laura M; Eadsforth, Peter; Beards, Susan C; Jackson, Alan

    2013-01-01

    Purpose. To compare a semiopen breathing circuit with a non-rebreathing (Hudson mask) for MRI experiments involving gas delivery. Methods and Materials. Cerebral blood flow (CBF) was measured by quantitative phase contrast angiography of the internal carotid and basilar arteries in 18 volunteers (20-31 years). In 8 subjects, gases were delivered via a standard non-rebreathing (Hudson mask). In 10 subjects, gases were delivered using a modified "Mapleson A" semiopen anesthetic gas circuit and mouthpiece. All subjects were given 100% O2, medical air, and carbogen gas (95% O2 and 5% CO2) delivered at 15 L/min in a random order. Results. The Hudson mask group showed significant increases in CBF in response to increased FiCO2 compared to air (+9.8%). A small nonsignificant reduction in CBF (-2.4%) was seen in response to increased inspired concentrations of oxygen (FiO2). The Mapleson A group showed significantly larger changes in CBF in response to both increased inspired concentrations of carbon dioxide (FiCO2) (+32.2%, P < 0.05) and FiO2 (-14.6%, P < 0.01). Conclusions. The use of an anaesthetic gas delivery circuit avoids entrainment of room air and rebreathing effects that may otherwise adversely affect the experimental results. PMID:24392225

  4. 75 FR 37431 - Pacific Gas & Electric Co.; Notice of Public Meeting on Draft Environmental Impact Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-29

    ... Energy Regulatory Commission Pacific Gas & Electric Co.; Notice of Public Meeting on Draft Environmental... last three digits in the docket number field to access the document. For assistance, contact FERC... Electric Company. This meeting is open to the public. At this meeting, State and Federal resource...

  5. 78 FR 62012 - Transcontinental Gas Pipeline Company; Notice of Availability of the Draft Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-11

    ... system in New York City. For the Northeast Connector Project, Transco proposes to modify existing compressor station facilities along its existing pipeline system in Pennsylvania and New Jersey to provide... requests authorization to expand its natural gas pipeline system in New York to provide firm...

  6. When galaxy clusters collide: the impact of merger shocks on cluster gas and galaxy evolution

    NASA Astrophysics Data System (ADS)

    Stroe, A.

    2015-09-01

    Galaxy clusters mainly grow through mergers with other clusters and groups. Major mergers give rise to cluster-wide traveling shocks, which can be detected at radio wavelengths as relics: elongated, diffuse synchrotron emitting areas located at the periphery of merging clusters. The 'Sausage' cluster hosts an extraordinary Mpc-wide relic, which enables us to study to study particle acceleration and the effects of shocks on cluster galaxies. We derive shock properties and the magnetic field structure for the relic. Our results indicate that particles are shock-accelerated, but turbulent re-acceleration or unusually efficient transport of particles in the downstream area are important effects. We demonstrate the feasibility of high-frequency observations of radio relics, by presenting a 16 GHz detection of the 'Sausage' relic. Halpha mapping of the cluster provides the first direct test as to whether the shock drives or prohibits star formation. We find numerous galaxies in! close proximity to the radio relic which are extremely massive, metal-rich, star-forming with evidence for gas mass loss though outflows. We speculate that the complex interaction between the merger, the shock wave and gas is a fundamental driver in the evolution of cluster galaxies from gas rich spirals to gas-poor ellipticals.

  7. Identifying emerging smart grid impacts to upstream and midstream natural gas operations.

    SciTech Connect

    McIntyre, Annie

    2010-09-01

    The Smart Grid has come to describe a next-generation electrical power system that is typified by the increased use of communications and information technology in the generation, delivery and consumption of electrical energy. Much of the present Smart Grid analysis focuses on utility and consumer interaction. i.e. smart appliances, home automation systems, rate structures, consumer demand response, etc. An identified need is to assess the upstream and midstream operations of natural gas as a result of the smart grid. The nature of Smart Grid, including the demand response and role of information, may require changes in upstream and midstream natural gas operations to ensure availability and efficiency. Utility reliance on natural gas will continue and likely increase, given the backup requirements for intermittent renewable energy sources. Efficient generation and delivery of electricity on Smart Grid could affect how natural gas is utilized. Things that we already know about Smart Grid are: (1) The role of information and data integrity is increasingly important. (2) Smart Grid includes a fully distributed system with two-way communication. (3) Smart Grid, a complex network, may change the way energy is supplied, stored, and in demand. (4) Smart Grid has evolved through consumer driven decisions. (5) Smart Grid and the US critical infrastructure will include many intermittent renewables.

  8. Impact of biochar field aging on laboratory greenhouse gas production potentials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent observations of decreased greenhouse gas (GHG) production from biochar amended soils have been used to further substantiate the environmental benefit of biochar production and soil incorporation strategies. However, the mechanisms behind the “biochar effect” have not been fully elucidated. In...

  9. Impact study on the use of biomass-derived fuels in gas turbines for power generation

    SciTech Connect

    Moses, C A; Bernstein, H

    1994-01-01

    This report evaluates the properties of fuels derived from biomass, both gaseous and liquid, against the fuel requirements of gas turbine systems for gernating electrical power. The report attempts to be quantitative rather than merely qualitative to establish the significant variations in the properties of biomass fuels from those of conventional fuels. Three general categories are covered: performance, durability, and storage and handling.

  10. Impact of Dissociation and Sensible Heat Release on Pulse Detonation and Gas Turbine Engine Performance

    NASA Technical Reports Server (NTRS)

    Povinelli, Louis A.

    2001-01-01

    A thermodynamic cycle analysis of the effect of sensible heat release on the relative performance of pulse detonation and gas turbine engines is presented. Dissociation losses in the PDE (Pulse Detonation Engine) are found to cause a substantial decrease in engine performance parameters.

  11. Cropping System Management Impacts on Greenhouse Gas Emissions in the Cool, Humid Northeastern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estimating global greenhouse gas (GHG) emissions requires regional measurements be made within different production systems. A long-term potato cropping system experiment established in 2004 in Presque Isle, ME, on a sandy loam soil was designed to contribute to three of the following scenarios rel...

  12. The Effect of Greenhouse Gas Mitigation on Drought Impacts in the U.S.

    EPA Science Inventory

    In this paper, we present a methodology for analyzing the economic benefits in the U.S. of changes in drought frequency and severity due to global greenhouse gas (GHG) mitigation. We construct reduced-form models of the effect of drought on agriculture and reservoir recreation i...

  13. Social Impacts of Oil and Gas Developments on a Small Rural Community.

    ERIC Educational Resources Information Center

    Copp, James H.

    To examine the effects of the 1978-81 oil and gas boom on social and economic relations and institutions in Caldwell, Texas, researchers gathered data about the community using census information, historical accounts, official records, publications, observations, interviews, and surveys of 133 residents, 91 businesses, and 40 oil field service…

  14. Impact of different plants on the gas profile of a landfill cover

    SciTech Connect

    Reichenauer, Thomas G.; Watzinger, Andrea; Riesing, Johann; Gerzabek, Martin H.

    2011-05-15

    Research highlights: > Plants influence gas profile and methane oxidation in landfill covers. > Plants regulate water content and increase the availability of oxygen for methane oxidation. > Plant species with deep roots like alfalfa showed more stimulation of methane oxidation than plants with shallow root systems like grasses. - Abstract: Methane is an important greenhouse gas emitted from landfill sites and old waste dumps. Biological methane oxidation in landfill covers can help to reduce methane emissions. To determine the influence of different plant covers on this oxidation in a compost layer, we conducted a lysimeter study. We compared the effect of four different plant covers (grass, alfalfa + grass, miscanthus and black poplar) and of bare soil on the concentration of methane, carbon dioxide and oxygen in lysimeters filled with compost. Plants were essential for a sustainable reduction in methane concentrations, whereas in bare soil, methane oxidation declined already after 6 weeks. Enhanced microbial activity - expected in lysimeters with plants that were exposed to landfill gas - was supported by the increased temperature of the gas in the substrate and the higher methane oxidation potential. At the end of the first experimental year and from mid-April of the second experimental year, the methane concentration was most strongly reduced in the lysimeters containing alfalfa + grass, followed by poplar, miscanthus and grass. The observed differences probably reflect the different root morphology of the investigated plants, which influences oxygen transport to deeper compost layers and regulates the water content.

  15. The impact of internet-connected control systems on the oil and gas industry

    NASA Astrophysics Data System (ADS)

    Martel, Ruth T.

    In industry and infrastructure today, communication is a way of life. In the oil and gas industry, the use of devices that communicate with the network at large is both commonplace and expected. Unfortunately, security on these devices is not always best. Many industrial control devices originate from legacy devices not originally configured with security in mind. All infrastructure and industry today has seen an increase in attacks on their networks and in some cases, a very dramatic increase, which should be a cause for alarm and action. The purpose of this research was to highlight the threat that Internet-connected devices present to an organization's network in the oil and gas industry and ultimately, to the business and possibly even human life. Although there are several previous studies that highlight the problem of these Internet-connected devices, there remains evidence that security response has not been adequate. The analysis conducted on only one easily discovered device serves as an example of the ongoing issue of the security mindset in the oil and gas industry. The ability to connect to a network through an Internet-connected device gives a hacker an anonymous backdoor to do great damage in that network. The hope is that the approach to security in infrastructure and especially the oil and gas industry, changes before a major catastrophe occurs involving human life.

  16. Hazard Ranking Methodology for Assessing Health Impacts of Unconventional Natural Gas Development and Production: The Maryland Case Study

    PubMed Central

    Sangaramoorthy, Thurka; Wilson, Sacoby; Nachman, Keeve E.; Babik, Kelsey; Jenkins, Christian C.; Trowell, Joshua; Milton, Donald K.; Sapkota, Amir

    2016-01-01

    The recent growth of unconventional natural gas development and production (UNGDP) has outpaced research on the potential health impacts associated with the process. The Maryland Marcellus Shale Public Health Study was conducted to inform the Maryland Marcellus Shale Safe Drilling Initiative Advisory Commission, State legislators and the Governor about potential public health impacts associated with UNGDP so they could make an informed decision that considers the health and well-being of Marylanders. In this paper, we describe an impact assessment and hazard ranking methodology we used to assess the potential public health impacts for eight hazards associated with the UNGDP process. The hazard ranking included seven metrics: 1) presence of vulnerable populations (e.g. children under the age of 5, individuals over the age of 65, surface owners), 2) duration of exposure, 3) frequency of exposure, 4) likelihood of health effects, 5) magnitude/severity of health effects, 6) geographic extent, and 7) effectiveness of setbacks. Overall public health concern was determined by a color-coded ranking system (low, moderately high, and high) that was generated based on the overall sum of the scores for each hazard. We provide three illustrative examples of applying our methodology for air quality and health care infrastructure which were ranked as high concern and for water quality which was ranked moderately high concern. The hazard ranking was a valuable tool that allowed us to systematically evaluate each of the hazards and provide recommendations to minimize the hazards. PMID:26726918

  17. Hazard Ranking Methodology for Assessing Health Impacts of Unconventional Natural Gas Development and Production: The Maryland Case Study.

    PubMed

    Boyle, Meleah D; Payne-Sturges, Devon C; Sangaramoorthy, Thurka; Wilson, Sacoby; Nachman, Keeve E; Babik, Kelsey; Jenkins, Christian C; Trowell, Joshua; Milton, Donald K; Sapkota, Amir

    2016-01-01

    The recent growth of unconventional natural gas development and production (UNGDP) has outpaced research on the potential health impacts associated with the process. The Maryland Marcellus Shale Public Health Study was conducted to inform the Maryland Marcellus Shale Safe Drilling Initiative Advisory Commission, State legislators and the Governor about potential public health impacts associated with UNGDP so they could make an informed decision that considers the health and well-being of Marylanders. In this paper, we describe an impact assessment and hazard ranking methodology we used to assess the potential public health impacts for eight hazards associated with the UNGDP process. The hazard ranking included seven metrics: 1) presence of vulnerable populations (e.g. children under the age of 5, individuals over the age of 65, surface owners), 2) duration of exposure, 3) frequency of exposure, 4) likelihood of health effects, 5) magnitude/severity of health effects, 6) geographic extent, and 7) effectiveness of setbacks. Overall public health concern was determined by a color-coded ranking system (low, moderately high, and high) that was generated based on the overall sum of the scores for each hazard. We provide three illustrative examples of applying our methodology for air quality and health care infrastructure which were ranked as high concern and for water quality which was ranked moderately high concern. The hazard ranking was a valuable tool that allowed us to systematically evaluate each of the hazards and provide recommendations to minimize the hazards. PMID:26726918

  18. Climate Change Impacts and Greenhouse Gas Mitigation Effects on U.S. Hydropower Generation

    EPA Science Inventory

    Climate change will have potentially significant effects on hydropower generation due to changes in the magnitude and seasonality of river runoff and increases in reservoir evaporation. These physical impacts will in turn have economic consequences through both producer revenues ...

  19. Determining the Origins and Impact of Hot Gas in the Milky Way

    NASA Astrophysics Data System (ADS)

    Miller, Matthew J.; Bregman, Joel N.; Hodges-Kluck, Edmund J.

    2016-01-01

    The Milky Way's circumgalactic medium contains million degree gas that is volume-filling on ≥10 kpc scales based on X-ray emission from the ROSAT All-Sky Survey, detections of OVII Kα (λ=21.602 Å) absorption lines at z~0 in AGN spectra, ubiquitous detections of OVII-OVIII emission lines in ~1,000 blank-sky spectra, and the discovery of the ~10 kpc outflow from the Galactic center known as the Fermi bubbles. Analyses on the line strengths in individual or small samples of sight lines (< 30) imply plasma densities between 10-5-10-2 cm-3, but the dominant hot gas structure is argued to be either a disk morphology (~108 M⊙ of material) or a spherical morphology (1010-1011 M⊙ of material). This is a crucial distinction since these morphologies arise from significantly different galaxy evolution processes, and the Fermi bubbles are recently discovered objects that are interacting with the ambient CGM. In this dissertation, I constrain the global hot gas density structure by comparing the largest samples of OVII equivalent width measurements and OVII-OVIII line intensities with model line strengths from parametric density models. I find that a spherical profile with n ∝ r-3/2 extending to the Milky Way's virial radius results in model line strenghts that are most consistent with how the observed line strengths vary across the sky. These results imply a hot gas mass between 2-5 x 1010 M⊙ within 250 kpc (≤ 50% of the Galactic missing baryons), a hot gas metallicity of Z ≥ .3 Z⊙, and that most of the hot gas formed as shock-heated material during the Milky Way's formation. For the Fermi bubbles, the line intensities and ratios suggest they contain hotter gas than the surrounding medium (> 2 x 106 K) and densities between 10-4-10-3 cm-3. This implies the bubbles are over-pressurized and expanding into the surrounding halo, potentially heating and displacing the ambient CGM.

  20. The extra-large light-gas gun of the Fraunhofer EMI: Applications for impact cratering research

    NASA Astrophysics Data System (ADS)

    Lexow, B.; Wickert, M.; Thoma, K.; SchńFer, F.; Poelchau, M. H.; Kenkmann, T.

    2013-01-01

    The extra-large light-gas gun (XLLGG) at the Fraunhofer Ernst-Mach-Institut (EMI, Efringen-Kirchen, Germany) is a two-stage light-gas gun that can accelerate projectile masses of up to 100 g up to velocities of 6 km s-1. The accelerator's set-up allows various combinations of pump and launch tubes for applications in different fields of hypervelocity impact research. In the framework of the MEMIN (Multidisciplinary Experimental and Modeling Impact Research Network) program, the XLLGG is used for mesoscale cratering experiments with projectiles made of steel and of iron meteorites, and targets consisting of sandstone and other rocks. The craters produced with this equipment reach a diameter of up to 40 cm, a size unique in laboratory cratering research. With the implementation of neural networks, the acceleration process is being optimized, currently yielding peak velocities of 7.8 km s-1 for a 100 g projectile. Here, we summarize technical aspects of the XLLGG.

  1. Evaluating options for balancing the water-electricity nexus in California: Part 2--greenhouse gas and renewable energy utilization impacts.

    PubMed

    Tarroja, Brian; AghaKouchak, Amir; Sobhani, Reza; Feldman, David; Jiang, Sunny; Samuelsen, Scott

    2014-11-01

    A study was conducted to compare the technical potential and effectiveness of different water supply options for securing water availability in a large-scale, interconnected water supply system under historical and climate-change augmented inflow and demand conditions. Part 2 of the study focused on determining the greenhouse gas and renewable energy utilization impacts of different pathways to stabilize major surface reservoir levels. Using a detailed electric grid model and taking into account impacts on the operation of the water supply infrastructure, the greenhouse gas emissions and effect on overall grid renewable penetration level was calculated for each water supply option portfolio that successfully secured water availability from Part 1. The effects on the energy signature of water supply infrastructure were found to be just as important as that of the fundamental processes for each option. Under historical (baseline) conditions, many option portfolios were capable of securing surface reservoir levels with a net neutral or negative effect on emissions and a benefit for renewable energy utilization. Under climate change augmented conditions, however, careful selection of the water supply option portfolio was required to prevent imposing major emissions increases for the system. Overall, this analysis provided quantitative insight into the tradeoffs associated with choosing different pathways for securing California's water supply. PMID:25087186

  2. Impact of alternative fuels on emissions characteristics of a gas turbine engine - part 1: gaseous and particulate matter emissions.

    PubMed

    Lobo, Prem; Rye, Lucas; Williams, Paul I; Christie, Simon; Uryga-Bugajska, Ilona; Wilson, Christopher W; Hagen, Donald E; Whitefield, Philip D; Blakey, Simon; Coe, Hugh; Raper, David; Pourkashanian, Mohamed

    2012-10-01

    Growing concern over emissions from increased airport operations has resulted in a need to assess the impact of aviation related activities on local air quality in and around airports, and to develop strategies to mitigate these effects. One such strategy being investigated is the use of alternative fuels in aircraft engines and auxiliary power units (APUs) as a means to diversify fuel supplies and reduce emissions. This paper summarizes the results of a study to characterize the emissions of an APU, a small gas turbine engine, burning conventional Jet A-1, a fully synthetic jet fuel, and other alternative fuels with varying compositions. Gas phase emissions were measured at the engine exit plane while PM emissions were recorded at the exit plane as well as 10 m downstream of the engine. Five percent reduction in NO(x) emissions and 5-10% reduction in CO emissions were observed for the alternative fuels. Significant reductions in PM emissions at the engine exit plane were achieved with the alternative fuels. However, as the exhaust plume expanded and cooled, organic species were found to condense on the PM. This increase in organic PM elevated the PM mass but had little impact on PM number. PMID:22913288

  3. Impacts of prescribed burning on soil greenhouse gas fluxes in a suburban native forest of south-eastern Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Wang, Y. Z.; Xu, Z. H.; Fu, L.

    2015-11-01

    Prescribed burning is a forest management practice that is widely used in Australia to reduce the risk of damaging wildfires. Prescribed burning can affect both carbon (C) and nitrogen (N) cycling in the forest and thereby influence the soil-atmosphere exchange of major greenhouse gases, i.e. carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). To quantify the impact of a prescribed burning (conducted on 27 May 2014) on greenhouse gas exchange and the potential controlling mechanisms, we carried out a series of field measurements before (August 2013) and after (August 2014 and November 2014) the fire. Gas exchange rates were determined in four replicate plots which were burned during the combustion and in another four adjacent unburned plots located in green islands, using a set of static chambers. Surface soil properties including temperature, pH, moisture, soil C and N pools were also determined either by in situ measurement or by analysing surface 10 cm soil samples. All of the chamber measurements indicated a net sink of atmospheric CH4, with mean CH4 uptake ranging from 1.15 to 1.99 mg m-2 d-1. Prescribed burning significantly enhanced CH4 uptake as indicated by the significant higher CH4 uptake rates in the burned plots measured in August 2014. In the following 3 months, the CH4 uptake rate was recovered to the pre-burning level. Mean CO2 emission from the forest soils ranged from 2721.76 to 7113.49 mg m-2 d-1. The effect of prescribed burning on CO2 emission was limited within the first 3 months, as no significant difference was observed between the burned and the adjacent unburned plots in both August and November 2014. The CO2 emissions showed more seasonal variations, rather than the effects of prescribed burning. The N2O emission in the plots was quite low, and no significant impact of prescribed burning was observed. The changes in understory plants and litter layers, surface soil temperature, C and N substrate availability and microbial

  4. Impact of anti-tacking agents on properties of gas-entrapped membrane and effervescent floating tablets.

    PubMed

    Kriangkrai, Worawut; Puttipipatkhachorn, Satit; Sriamornsak, Pornsak; Pongjanyakul, Thaned; Sungthongjeen, Srisagul

    2014-12-01

    Tackiness caused by the gas-entrapped membrane (Eudragit(®)RL 30D) was usually observed during storage of the effervescent floating tablets, leading to failure in floatation and sustained release. In this work, common anti-tacking agents (glyceryl monostearate (GMS) and talc) were used to solve this tackiness problem. The impact of anti-tacking agent on the properties of free films and corresponding floating tablets was investigated. GMS was more effective than talc in reducing tackiness of the film. Addition and increasing amount of anti-tacking agents lowered the film mechanical strength, but the coating films were still strong and flexible enough to resist the generated gas pressure inside the floating tablet. Wettability and water vapor permeability of the film decreased with increasing level of anti-tacking agents as a result of their hydrophobicity. No interaction between anti-tacking agents and polymer was observed as confirmed by Fourier transform infrared spectroscopy, powder X-ray diffractometry, and differential scanning calorimetry studies. Increasing amount of anti-tacking agents decreased time to float and tended to retard drug release of the floating tablets. Floating properties and drug release were also influenced by type of anti-tacking agents. The obtained floating tablets still possessed good floating properties and controlled drug release even though anti-tacking agent had some effects. The results demonstrated that the tackiness problem of the floating tablets could be solved by incorporating anti-tacking agent into the gas-entrapped membrane. PMID:24927669

  5. Impact of Marcellus Shale natural gas development in southwest Pennsylvania on volatile organic compound emissions and regional air quality.

    PubMed

    Swarthout, Robert F; Russo, Rachel S; Zhou, Yong; Miller, Brandon M; Mitchell, Brittney; Horsman, Emily; Lipsky, Eric; McCabe, David C; Baum, Ellen; Sive, Barkley C

    2015-03-01

    The Marcellus Shale is the largest natural gas deposit in the U.S. and rapid development of this resource has raised concerns about regional air pollution. A field campaign was conducted in the southwestern Pennsylvania region of the Marcellus Shale to investigate the impact of unconventional natural gas (UNG) production operations on regional air quality. Whole air samples were collected throughout an 8050 km(2) grid surrounding Pittsburgh and analyzed for methane, carbon dioxide, and C1-C10 volatile organic compounds (VOCs). Elevated mixing ratios of methane and C2-C8 alkanes were observed in areas with the highest density of UNG wells. Source apportionment was used to identify characteristic emission ratios for UNG sources, and results indicated that UNG emissions were responsible for the majority of mixing ratios of C2-C8 alkanes, but accounted for a small proportion of alkene and aromatic compounds. The VOC emissions from UNG operations accounted for 17 ± 19% of the regional kinetic hydroxyl radical reactivity of nonbiogenic VOCs suggesting that natural gas emissions may affect compliance with federal ozone standards. A first approximation of methane emissions from the study area of 10.0 ± 5.2 kg s(-1) provides a baseline for determining the efficacy of regulatory emission control efforts. PMID:25594231

  6. Air toxics regulations and their potential impact on the natural gas industry. Topical report, June 1991-October 1992

    SciTech Connect

    Fillo, J.P.; Harkov, R.; Koraido, S.M.; Olsakovsky, A.C.

    1992-10-01

    The objective of this effort was to perform an assessment of the potential impacts of air toxics regulations on the natural gas industry. Natural gas industry operations were reviewed to identify potential sources of air toxics emissions and representative compounds that may be emitted, as one basis for the evaluation. Legislation that regulate air toxics exist at the federal and state levels. The federal review addressed primarily the Clean Air Act (CAA), specifically the air toxics provisions under Title III of the 1990 CAA Amendments. Other relevant federal regulations were reviewed, including OSHA, TSCA, CERCLA, SARA Title III, and RCRA. Regulations for three bellweather states (i.e., Texas, New Jersey, California) were reviewed to assess relevant state air toxics regulations. Natural gas operations have the potential to emit air toxics, including benzene, toluene, ethylbenzene, and xylene (BTEX) emissions from glycol dehydration vents, products of incomplete combustion from compressor engines, fugitive emissions from facility equipment, and secondary emissions from storage and waste treatment facilities.

  7. Impact of Natural Gas Appliances on Pollutant Levels in California Homes

    SciTech Connect

    Mullen, Nasim A.; Li, Jina; Singer, Brett C.

    2012-12-01

    This report presents results from the first year of a 2-year study, investigating associations of five air pollutants (CO, NO2, NOX, formaldehyde and acetaldehyde) with the presence of natural gas appliances in California homes. From November 2011 to March 2012, pollutant concentration and occupant activity data were collected in 155 homes for 6-day periods. The sample population included both single-family (68%) and multi-family (32%) dwellings, with 87% having at least one gas appliance and 77% having an unvented gas cooking appliance. The geometric mean (GM) NO2 levels measured in the kitchen, bedroom and outside of homes were similar at values of 15, 12 and 11 ppb, respectively. In contrast, the GM NOx levels measured in the kitchen and bedroom of homes were much higher than levels measured outdoors, at levels of 42 and 41 ppb, compared to 19 ppb, respectively. Roughly 10% of sampled homes had 6-day average NO2 levels that exceeded the outdoor annual average limit set by the California Ambient Air Quality Standards (CAAQS) (30 ppb). The GMs of the highest 1-h and 8-h CO level measured in homes were 2.5 and 1.1 ppm, respectively. Four homes had a 1-h or 8-h concentration that exceeded the outdoor limits set by the CAAQS. The GM formaldehyde and acetaldehyde concentrations measured in homes were 15 and 7 ppb, respectively. Roughly 95% of homes had average formaldehyde levels indoors that exceeded the Chronic Reference Exposure Level set by the California EPA (7 ppb). Concentrations of NO2 and NOx, and to a lesser extent CO were associated with use of gas appliances, particularly unvented gas cooking appliances. Based on first principles, it is expected that effective venting of cooking pollutant emissions at the source will lead to a reduction of pollutant concentrations. However, no statistical association was detected between kitchen exhaust fan use and pollutant concentrations in homes in this study where gas cooking occurred frequently. The lack of

  8. Quantifying Aerosol Types and Their Impact on Trace Gas Retrievals From Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Natraj, V.; Boesch, H.; Yung, Y. L.

    2005-12-01

    One of the major sources of uncertainty in the retrieval of trace gas abundances from space-borne measurements is the type, amount and vertical distribution of aerosols in the atmosphere. Optical properties were derived for the broad classification of aerosol types investigated by Kahn et al. (2001), taking polarization into account. Examination of the scattering matrix elements resulted in a smaller set of independent aerosol types whose radiative effects were different. Weighting functions were then calculated for each of these types, assuming exponentially tailing aerosol concentration in the troposphere and a Junge distribution for the stratosphere. The different shapes of the weighting functions indicate different amount and distribution of the information content. Implications for trace gas retrievals from satellite-based measurements made by polarization-sensitive instruments (such as those on OMI, GOME, SCIAMACHY and OCO) will be discussed.

  9. NAECA impact on gas-fired space heating equipment. Phase report September 1991-March 1992

    SciTech Connect

    Thrasher, W.H.; Dewerth, D.W.; Jakob, F.E.; Crisafulli, J.J.

    1992-09-30

    The report describes a program aimed at preparing the gas industry to provide input to the National Appliance Energy Conservation Act rulemaking process for furnaces, including mobile home furnaces, and boilers. The Phase I work described herein is aimed at organizing the gas industry by establishing a Technical Advisory Group, visiting manufacturers to determine their needs, establishing liaison with DOE, LBL, GAMA, A.G.A., etc., and setting up provisions to experimentally evaluate design options identified by DOE as means to increase the minimum efficiency levels now in effect by NAECA. Also, a means is in place to transfer the technology to DOE and LBL to influence the Advance Notice Prior to Rulemaking (ANPRM) for furnaces and boilers, and the Notice Prior to Rulemaking (NPRM) for DHE, etc.

  10. On The Impact of Borescope Camera Air Purge on DWPF Melter Off-Gas Flammability

    SciTech Connect

    CHOI, ALEXANDER

    2004-07-22

    DWPF Engineering personnel requested that a new minimum backup film cooler air flow rate, which will meet the off-gas safety basis limits for both normal and seismic sludge-only operations, be calculated when the air purge to the borescope cameras is isolated from the melter. Specifically, it was requested that the latest calculations which were used to set the off-gas flammability safety bases for the sludge batch 2 and 3 feeds be revised, while maintaining all other process variables affecting off-gas flammability such as total organic carbon (TOC), feed rate, melter air purges, and vapor space temperature at their current respective maximum or minimum limits. Before attempting to calculate the new minimum backup film cooler air flow, some of the key elements of the combustion model were reviewed, and it was determined that the current minimum backup film cooler air flow of 233 lb/hr is adequate to satisfy the off-gas flammability safety bases for both normal and seismic operations i n the absence of any borescope camera air purge. It is, therefore, concluded that there is no need to revise the reference E-7 calculations. This conclusion is in essence based on the fact that the current minimum backup film cooler air flow was set to satisfy the minimum combustion air requirement under the worst-case operating scenario involving a design basis earthquake during which all the air purges not only to the borescope cameras but to the seal pot are presumed to be lost due to pipe ruptures. The minimum combustion air purge is currently set at 150 per cent of the stoichiometric air flow required to combust 3 times the normal flow of flammable gases. The DWPF control strategy has been that 100 per cent of the required minimum combustion air is to be provided by the controlled air purge through the backup film cooler alone.

  11. Evolving shale gas management: water resource risks, impacts, and lessons learned.

    PubMed

    Rahm, Brian G; Riha, Susan J

    2014-05-01

    Unconventional shale gas development promises to significantly alter energy portfolios and economies around the world. It also poses a variety of environmental risks, particularly with respect to the management of water resources. We review current scientific understanding of risks associated with the following: water withdrawals for hydraulic fracturing; wastewater treatment, discharge and disposal; methane and fluid migration in the subsurface; and spills and erosion at the surface. Some of these risks are relatively unique to shale gas development, while others are variations of risks that we already face from a variety of industries and activities. All of these risks depend largely on the pace and scale of development that occurs within a particular region. We focus on the United States, where the shale gas boom has been on-going for several years, paying particular attention to the Marcellus Shale, where a majority of peer-reviewed study has taken place. Governments, regulatory agencies, industry, and other stakeholders are challenged with responding to these risks, and we discuss policies and practices that have been adopted or considered by these various groups. Adaptive Management, a structured framework for addressing complex environmental issues, is discussed as a way to reduce polarization of important discussions on risk, and to more formally engage science in policy-making, along with other economic, social and value considerations. Data suggests that some risks can be substantially reduced through policy and best practice, but also that significant uncertainty persists regarding other risks. We suggest that monitoring and data collection related to water resource risks be established as part of planning for shale gas development before activity begins, and that resources are allocated to provide for appropriate oversight at various levels of governance. PMID:24664241

  12. Impact of Intrafractional Bowel Gas Movement on Carbon Ion Beam Dose Distribution in Pancreatic Radiotherapy

    SciTech Connect

    Kumagai, Motoki; Hara, Ryusuke; Mori, Shinichiro Yanagi, Takeshi; Asakura, Hiroshi; Kishimoto, Riwa; Kato, Hirotoshi; Yamada, Shigeru; Kandatsu, Susumu; Kamada, Tadashi

    2009-03-15

    Purpose: To assess carbon ion beam dose variation due to bowel gas movement in pancreatic radiotherapy. Methods and Materials: Ten pancreatic cancer inpatients were subject to diagnostic contrast-enhanced dynamic helical CT examination under breath-holding conditions, which included multiple-phase dynamic CT with arterial, venous, and delayed phases. The arterial-venous phase and arterial-delayed phase intervals were 35 and 145 s, respectively. A compensating bolus was designed to cover the target obtained at the arterial phase. Carbon ion dose distribution was calculated by applying the bolus to the CT data sets at the other two phases. Results: Dose conformation to the clinical target volume was degraded by beam overshoot/undershoot due to bowel gas movement. The D95 for clinical target volume was degraded from 98.2% (range, 98.0-99.1%) of the prescribed dose to 94.7% (range, 88.0-99.0%) at 145 s. Excessive dosing to normal tissues varied among tissues and was, for example, 12.2 GyE/13.1 GyE (0 s/145 s) for the cord and 38.8 GyE/39.8 GyE (0 s/145 s) for the duodenum. The magnitude of beam overshoot/undershoot was particularly exacerbated from the anterior and left directions. Conclusions: Bowel gas movement causes dosimetric variation to the target during treatment for radiotherapy. The effect of bowel gas movement varies with beam angle, with greatest influence on the anterior-posterior and left-right beams.

  13. Impact of Gas-liquid Two-phase Flow on Fluid Borne Noise

    NASA Astrophysics Data System (ADS)

    Taniwaki, Mitsuhiro; Shimomura, Nobuo

    In pipe lines such as those found in refrigeration cycle, a gas-liquid two-phase flow may occur because of a pressure change in the pipe. This flow causes noise. A vapor phase ratio in a fluid and the behavior of bubbles are related to the outbreak of noise. This experimental study investigated the fluid borne noise caused by gas-liquid two-phase flow passing through a contracted section in horizontal pipe. In the experiment, sound pressure was measured for two purposes: to see the influence of the air-water ratio on sound pressure and to see the change in sound pressure when a single bubble passed through a contracted section in horizontal pipe. The experiment showed that the fluid borne noise of gas-liquid two-phase flow grew louder than that of a liquid single-phase flow. As for the frequency distribution of the fluid borne noise, the sound pressure level was higher in the high frequency band. Furthermore, the fluid borne noise grew louder with increasing bubble diameter.

  14. Impact of different plants on the gas profile of a landfill cover.

    PubMed

    Reichenauer, Thomas G; Watzinger, Andrea; Riesing, Johann; Gerzabek, Martin H

    2011-05-01

    Methane is an important greenhouse gas emitted from landfill sites and old waste dumps. Biological methane oxidation in landfill covers can help to reduce methane emissions. To determine the influence of different plant covers on this oxidation in a compost layer, we conducted a lysimeter study. We compared the effect of four different plant covers (grass, alfalfa+grass, miscanthus and black poplar) and of bare soil on the concentration of methane, carbon dioxide and oxygen in lysimeters filled with compost. Plants were essential for a sustainable reduction in methane concentrations, whereas in bare soil, methane oxidation declined already after 6 weeks. Enhanced microbial activity - expected in lysimeters with plants that were exposed to landfill gas - was supported by the increased temperature of the gas in the substrate and the higher methane oxidation potential. At the end of the first experimental year and from mid-April of the second experimental year, the methane concentration was most strongly reduced in the lysimeters containing alfalfa+grass, followed by poplar, miscanthus and grass. The observed differences probably reflect the different root morphology of the investigated plants, which influences oxygen transport to deeper compost layers and regulates the water content. PMID:20888746

  15. An assessment of radiolytic gas generation: Impacts from Rocky Flats Plant residue elimination alternatives. Final report

    SciTech Connect

    Not Available

    1993-02-26

    This report evaluates the Sandia National Laboratory-Albuquerque analytical model that is used to support present wattage limit decisions for various matrix forms from the Residue Elimination Project for Waste Isolation Pilot Plant waste acceptability. This study includes (1) a comparison of the SNL-A model to Rocky Flats Plant models for consistency of assumptions and the phenomena considered in the models, and (2) an evaluation of the appropriateness of the Sandia National Laboratory-Albuquerque model to Rocky Flats Plant residues, considering that the original intent was to model wastes rather than residues. The study draws the following conclusions: (1) only real-time gas generation testing of specific waste streams may provide a sound basis for an increase in the transportation wattage limit of specific waste streams, and (2) the radiolytic gas generation rate from Residue Elimination Project waste emplaced at Waste Isolation Pilot Plant, under worst-case conditions, is not a significant factor in comparison to the total gas generation rate due to radiolysis, microbial degradation, and corrosion.

  16. Impact of phytoplankton-generated surfactants on air-sea gas exchange

    NASA Astrophysics Data System (ADS)

    Frew, Nelson M.; Goldman, Joel C.; Dennett, Mark R.; Johnson, A. Sherwood

    1990-03-01

    The effect of surface-active organic matter generated by seven common species of marine phytoplankton on gas exchange rates under turbulent conditions at the air-water interface was determined. Reductions in oxygen evasion rates ranging from 5 to 50% were observed relative to clean seawater controls. Relative oxygen exchange coefficients (expressed as R = Kw [sample]/Kw [control]) were shown to be sensitive to small changes in total dissolved carbohydrate at concentrations <1 mg C (carbon) L-1 and to asymptotically decrease to a lower limit (R = 55-70%) at concentrations between 2 and 6 mg C L-1. A corresponding relationship was observed in which R decreased with increasing relative surfactant amounts derived from surface pressure-area measurements. However, gas exchange reductions were significant for plankton exudate samples displaying surface pressures ≲1 mN m-1. It thus seems that condensed monolayer films are not a prerequisite for reduced gas exchange and that relatively soluble surfactants derived from phytoplankton can strongly affect the dissipation of near-surface turbulence and lead to changes in the Schmidt number dependency of Kw. Based on detailed analyses of carbohydrate-containing surface-active exudates isolated by solid phase extraction from one of the species, Phaeodactylum tricornutum, it appears that small glucans and heteropolysaccharides associated with proteins and possibly lipids were responsible for the observed reductions in R.

  17. Impacts of shale gas wastewater disposal on water quality in western Pennsylvania.

    PubMed

    Warner, Nathaniel R; Christie, Cidney A; Jackson, Robert B; Vengosh, Avner

    2013-10-15

    The safe disposal of liquid wastes associated with oil and gas production in the United States is a major challenge given their large volumes and typically high levels of contaminants. In Pennsylvania, oil and gas wastewater is sometimes treated at brine treatment facilities and discharged to local streams. This study examined the water quality and isotopic compositions of discharged effluents, surface waters, and stream sediments associated with a treatment facility site in western Pennsylvania. The elevated levels of chloride and bromide, combined with the strontium, radium, oxygen, and hydrogen isotopic compositions of the effluents reflect the composition of Marcellus Shale produced waters. The discharge of the effluent from the treatment facility increased downstream concentrations of chloride and bromide above background levels. Barium and radium were substantially (>90%) reduced in the treated effluents compared to concentrations in Marcellus Shale produced waters. Nonetheless, (226)Ra levels in stream sediments (544-8759 Bq/kg) at the point of discharge were ~200 times greater than upstream and background sediments (22-44 Bq/kg) and above radioactive waste disposal threshold regulations, posing potential environmental risks of radium bioaccumulation in localized areas of shale gas wastewater disposal. PMID:24087919

  18. Impact of surface structure and feed gas composition on Bacillus subtilis endospore inactivation during direct plasma treatment.

    PubMed

    Hertwig, Christian; Steins, Veronika; Reineke, Kai; Rademacher, Antje; Klocke, Michael; Rauh, Cornelia; Schlüter, Oliver

    2015-01-01

    This study investigated the inactivation efficiency of cold atmospheric pressure plasma treatment on Bacillus subtilis endospores dependent on the used feed gas composition and on the surface, the endospores were attached on. Glass petri-dishes, glass beads, and peppercorns were inoculated with the same endospore density and treated with a radio frequency plasma jet. Generated reactive species were detected using optical emission spectroscopy. A quantitative polymerase chain reaction (qPCR) based ratio detection system was established to monitor the DNA damage during the plasma treatment. Argon + 0.135% vol. oxygen + 0.2% vol. nitrogen as feed gas emitted the highest amounts of UV-C photons and considerable amount of reactive oxygen and nitrogen species. Plasma generated with argon + 0.135% vol. oxygen was characterized by the highest emission of reactive oxygen species (ROS), whereas the UV-C emission was negligible. The use of pure argon showed a negligible emission of UV photons and atomic oxygen, however, the emission of vacuum (V)UV photons was assumed. Similar maximum inactivation results were achieved for the three feed gas compositions. The surface structure had a significant impact on the inactivation efficiency of the plasma treatment. The maximum inactivation achieved was between 2.4 and 2.8 log10 on glass petri-dishes and 3.9 to 4.6 log10 on glass beads. The treatment of peppercorns resulted in an inactivation lower than 1.0 log10. qPCR results showed a significant DNA damage for all gas compositions. Pure argon showed the highest results for the DNA damage ratio values, followed by argon + 0.135% vol. oxygen + 0.2% vol. nitrogen. In case of argon + 0.135% vol. oxygen the inactivation seems to be dominated by the action of ROS. These findings indicate the significant role of VUV and UV photons in the inactivation process of B. subtilis endospores. PMID:26300855

  19. Impact of surface structure and feed gas composition on Bacillus subtilis endospore inactivation during direct plasma treatment

    PubMed Central

    Hertwig, Christian; Steins, Veronika; Reineke, Kai; Rademacher, Antje; Klocke, Michael; Rauh, Cornelia; Schlüter, Oliver

    2015-01-01

    This study investigated the inactivation efficiency of cold atmospheric pressure plasma treatment on Bacillus subtilis endospores dependent on the used feed gas composition and on the surface, the endospores were attached on. Glass petri-dishes, glass beads, and peppercorns were inoculated with the same endospore density and treated with a radio frequency plasma jet. Generated reactive species were detected using optical emission spectroscopy. A quantitative polymerase chain reaction (qPCR) based ratio detection system was established to monitor the DNA damage during the plasma treatment. Argon + 0.135% vol. oxygen + 0.2% vol. nitrogen as feed gas emitted the highest amounts of UV-C photons and considerable amount of reactive oxygen and nitrogen species. Plasma generated with argon + 0.135% vol. oxygen was characterized by the highest emission of reactive oxygen species (ROS), whereas the UV-C emission was negligible. The use of pure argon showed a negligible emission of UV photons and atomic oxygen, however, the emission of vacuum (V)UV photons was assumed. Similar maximum inactivation results were achieved for the three feed gas compositions. The surface structure had a significant impact on the inactivation efficiency of the plasma treatment. The maximum inactivation achieved was between 2.4 and 2.8 log10 on glass petri-dishes and 3.9 to 4.6 log10 on glass beads. The treatment of peppercorns resulted in an inactivation lower than 1.0 log10. qPCR results showed a significant DNA damage for all gas compositions. Pure argon showed the highest results for the DNA damage ratio values, followed by argon + 0.135% vol. oxygen + 0.2% vol. nitrogen. In case of argon + 0.135% vol. oxygen the inactivation seems to be dominated by the action of ROS. These findings indicate the significant role of VUV and UV photons in the inactivation process of B. subtilis endospores. PMID:26300855

  20. Popular epidemiology and "fracking": citizens' concerns regarding the economic, environmental, health and social impacts of unconventional natural gas drilling operations.

    PubMed

    Powers, Martha; Saberi, Poune; Pepino, Richard; Strupp, Emily; Bugos, Eva; Cannuscio, Carolyn C

    2015-06-01

    Pennsylvania sits atop the Marcellus Shale, a reservoir of natural gas that was untapped until the 2004 introduction of unconventional natural gas drilling operations (UNGDO) in the state. Colloquially known as fracking, UNGDO is a controversial process that employs large volumes of water to fracture the shale and capture gas; it has become a multi-billion dollar industry in Pennsylvania. We analyzed letters to the editor of the most widely circulated local newspaper in the most heavily drilled county in Pennsylvania (Bradford County) in order to characterize residents' concerns and their involvement in popular epidemiology--the process by which citizens investigate risks associated with a perceived environmental threat. We reviewed 215 letters to the editor that referenced natural gas operations and were published by The Daily Review between January 1, 2008 and June 8, 2013. We used NVivo 10 to code and analyze letters and identify major themes. Nvivo is qualitative data analysis software (http://www.qsrinternational.com/products_nvivo.aspx) that allows researchers to code and analyze "unstructured" data, including text files of any type (e.g., interview transcripts, news articles, letters, archival materials) as well as photographs and videos. Nvivo can be used to classify, sort, query, comment on, and share data across a research group. Letters demonstrated citizen engagement in beginning and intermediate stages of lay epidemiology, as well as discord and stress regarding four main issues: socio-economic impacts, perceived threats to water, population growth and implications, and changes to the rural landscape. Residents called for stronger scientific evidence and a balance of economic development and health and environmental protections. Citizens' distress regarding UNGDO appeared to be exacerbated by a dearth of information to guide economic growth and health, environmental, and social concerns. This analysis proposes locally informed questions to guide future

  1. Drought Impact on Fumarole Gas Composition at Lassen Volcanic National Park, CA.

    NASA Astrophysics Data System (ADS)

    Bergfeld, D.; Lewicki, J. L.; Hunt, A. G.

    2015-12-01

    Surface expressions of the hydrothermal system at Lassen Volcanic National Park include numerous solfataras to the south and southeast of Lassen Peak. Extensive sampling of gas for chemical and isotope analyses took place from the mid-1970s through 2000. Based on those data the model for the Lassen hydrothermal system suggests the main gas upflow occurs at Sulphur Works, which is part of a circulating hydrothermal flow cell (HC1) that includes Bumpass Hell and Little Hot Springs Valley (Janik & McLaren, 2010). A second, slightly cooler cell (HC2) provides gas and steam to Boiling Springs Lake, Devils Kitchen and ultimately to features at Terminal Geyser. As part of the USGS volcano monitoring effort, sampling of Lassen gases resumed in 2014. Gas compositions of boiling point and superheated fumaroles at four of the Lassen solfataras contained lower concentrations of meteoric-derived components than most early samples. In 2014 the combined N2 and Ar concentrations from the individual areas decreased on average by 50 to 65% relative to CO2. N2/Ar ratios also shifted away from the ratio in air-saturated water toward values as high as 171, consistent with a decline in meteoric water content. Concentrations of hydrothermal gases CO2, H2S, and CH4, and d13C-CO2 values are similar to the early data. Helium concentrations are variable and show no trends. Helium isotope ratios (Rc/RA) since 2007 from HC1 are between 6.9 and 7.5 and for HC2 are between 6.0 and 6.5. A 2014 Terminal Geyser sample had a value of 6.0. A longer record of helium isotope data is required to examine temporal trends. Water in the Lassen hydrothermal system is ultimately derived from rain and snowfall at higher elevations in the park. The area has experienced drought conditions since at least 2012. The 2014 dataset suggests that the drought may influence gas compositions by reducing the input of shallow meteoric water. Lassen gases from the California drought of 1976-1977 exhibit similar behavior.

  2. Climate Change Impacts and Greenhouse Gas Mitigation Effects on US Water Quality

    EPA Science Inventory

    Climate change will have potentially significant effects on freshwater quality due to increases in river and lake temperatures, changes in the magnitude and seasonality of river runoff, and more frequent and severe extreme events. These physical impacts will in turn have economic...

  3. Impacts of oil and gas development on the recreation and tourism off the Florida straits

    SciTech Connect

    Bell, F.

    1991-05-01

    The study was undertaken for the purpose of addressing potential problems of OCS activities on tourism and recreation in Monroe County, Florida. The strategic objective of the study was to develop a model to simulate the effects of various OCS activities on tourism visitation, expenditures, and regional gross economic impacts.

  4. Impact of biochar on manure carbon stabilization and greenhouse gas emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies indicate that biochar additions sometimes increase soil respiration and carbon dioxide emissions, which could partially offset carbon (C) credits associated with soil biochar applications. Little is known, however, about the impact of biochar on the mineralization of manure in soil ...

  5. 76 FR 52655 - Pacific Gas and Electric Company; Notice of Availability of the Final Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ...) regulations, 18 CFR part 380 (Order No. 486, 52 FR 47897), the Office of Energy Projects has reviewed the application, filed March 12, 2009, requesting surrender of the Kilarc-Cow Creek Project (FERC No. 606) license... Environmental Impact Statement for the Kilarc-Cow Creek Hydroelectric Project In accordance with the...

  6. 75 FR 37429 - Pacific Gas and Electric Company; Notice of Availability of the Draft Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-29

    ... No. 486, 52 FR 47897), the Office of Energy Projects has reviewed the application, filed March 12, 2009, requesting surrender of the Kilarc-Cow Creek Project (FERC No. 606) license. The project is... Environmental Impact Statement for the Kilarc-Cow Creek Hydroelectric Project and Announcing Intention To...

  7. Manure management and temperature impacts on gas concentrations in monoslope cattle facilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Roofed and confined cattle feeding facilities are increasingly popular in the Northern Great Plains, but little is known about the impact this housing system and associated manure management methods have on the air quality inside and outside the barn. The objective of this study was to determine ga...

  8. The interaction between an impact-produced neutral gas cloud and the solar wind at the lunar surface

    NASA Technical Reports Server (NTRS)

    Lindeman, R. A.; Vondrak, R. R.; Freeman, J. W.; Snyder, C. W.

    1974-01-01

    On Apr. 15, 1970, the Apollo 13 S-IVB stage impacted the nighttime lunar surface. Beginning 20 sec after impact, the Suprathermal Ion Detector Experiment and the Solar Wind Spectrometer observed a large flux of positive ions (maximum flux of about 3 x 10 to the 8th ions/sq cm/sec/ster) and electrons. Two separate streams of ions were observed: a horizontal flux that appeared to be deflected solar wind ions and a smaller vertical flux of predominantly heavy ions (greater than 10 amu), which probably were material vaporized from the S-IVB stage. An examination of the data shows that collisions between neutral molecules and hot electrons (50 eV) were probably an important ionization mechanism in the impact-produced neutral gas cloud. These electrons, which were detected by the Solar Wind Spectrometer, are thought to have been energized in a shock front or some form of intense interaction region between the cloud and the solar wind. Thus strong ionization and acceleration are seen under conditions approaching a collisionless state.

  9. A new impact test for the identification of a dynamic crack propagation criterion using a gas-gun device

    NASA Astrophysics Data System (ADS)

    Nistor, I.; Pantalé, O.; Caperaa, S.

    2006-08-01

    The modelling of damage and fracture behaviour under high rates of loadings for metallic structures presents the more and more interests for engineering design, especially for crash phenomena. In order to perform a numerical simulation of such phenomena a crack propagation criterion must be identified using adapted laboratory tests. The objective of this paper is to present a new impact test intended for the identification of a cohesive crack criterion implemented into a home-made FEM code based on Extended Finite Element Method. Therefore, a double-notched specimen is impacted using a gas-gun device in order to obtain different crack paths depending on projectile speed. A post-impact macro-photographic observation allows to measure the crack path, the angles and the advancing length. These experimental results are used as input responses in the identification procedure for determining the crack cohesive criterion parameters. Some experimental results, for an aluminium alloy crack criterion identification, are presented to illustrate the proposed approach.

  10. Impact origin of the Avak structure, Arctic Alaska, and genesis of the Barrow gas fields

    SciTech Connect

    Kirschner, C.E. ); Grantz, A.; Mullen, M.W. )

    1992-05-01

    Geophysical and subsurface geologic data suggest that the Avak structure, which underlies the Arctic Coastal Plain 12 km southeast of Barrow, Alaska, is a hypervelocity meteorite or comet impact structure. The structure is a roughly circular area of uplifted, chaotically deformed Upper Triassic to Lower Cretaceous sedimentary rocks 8 km in diameter that is bounded by a ring of anastomosing, inwardly dipping, listric normal faults 12 km in diameter. A zone of gently outward-dipping sedimentary country rocks forms a discontinuous ring of rim anticlines within the peripheral ring of normal faults. Beyond these anticlines, the sedimentary rocks are almost flat-lying. Data concerning the age of the Avak structure are not definitive. If submarine landslide deposits in the upper part of the Aptian and Albian Torok Formation, in the subsurface 200 km to the east, were triggered by the Avak event, then the Avak meteorite struck a submerged marine shelf about 100 [plus minus] 5 Ma. However, the impact features found at Avak characterize the distal zones of meteorite impact structures. Fused rocks, plastic deformation, and shock-metamorphic minerals found in more proximal zones of impact structures are apparently missing. These observations, and the lack of Avak ejecta in cuttings and cores from the Torok Formation and Nanushuk Group in surrounding test wells, indicate that the impact event postdated these beds. In this case, the Avak meteorite struck a Late Cretaceous or Tertiary marine shelf or coastal plain between the Cenomanian (ca. 95 Ma), and deposition of the basal beds of the overlying late Pliocene and Quaternary Gubik Formation (ca. 3 Ma).

  11. Fuel-cycle greenhouse gas emissions impacts of alternative transportation fuels and advanced vehicle technologies.

    SciTech Connect

    Wang, M. Q.

    1998-12-16

    At an international conference on global warming, held in Kyoto, Japan, in December 1997, the United States committed to reduce its greenhouse gas (GHG) emissions by 7% over its 1990 level by the year 2012. To help achieve that goal, transportation GHG emissions need to be reduced. Using Argonne's fuel-cycle model, I estimated GHG emissions reduction potentials of various near- and long-term transportation technologies. The estimated per-mile GHG emissions results show that alternative transportation fuels and advanced vehicle technologies can help significantly reduce transportation GHG emissions. Of the near-term technologies evaluated in this study, electric vehicles; hybrid electric vehicles; compression-ignition, direct-injection vehicles; and E85 flexible fuel vehicles can reduce fuel-cycle GHG emissions by more than 25%, on the fuel-cycle basis. Electric vehicles powered by electricity generated primarily from nuclear and renewable sources can reduce GHG emissions by 80%. Other alternative fuels, such as compressed natural gas and liquefied petroleum gas, offer limited, but positive, GHG emission reduction benefits. Among the long-term technologies evaluated in this study, conventional spark ignition and compression ignition engines powered by alternative fuels and gasoline- and diesel-powered advanced vehicles can reduce GHG emissions by 10% to 30%. Ethanol dedicated vehicles, electric vehicles, hybrid electric vehicles, and fuel-cell vehicles can reduce GHG emissions by over 40%. Spark ignition engines and fuel-cell vehicles powered by cellulosic ethanol and solar hydrogen (for fuel-cell vehicles only) can reduce GHG emissions by over 80%. In conclusion, both near- and long-term alternative fuels and advanced transportation technologies can play a role in reducing the United States GHG emissions.

  12. Cooking a `Sausage': the impact of merger shocks in cluster gas and galaxy evolution

    NASA Astrophysics Data System (ADS)

    Stroe, Andra; Sobral, David; Harwood, Jeremy; Van Weeren, Reinout J.; Rumsey, Clare; Intema, Huib; Röttgering, Huub; Brüggen, Marcus; Saunders, Richard; Hardcastle, Martin; Hoeft, Matthias

    2015-01-01

    Galaxy clusters mainly grow through mergers with other clusters and groups. Major mergers give rise to important astrophysical phenomena such as the segregation of dark and luminous matter and the formation of cluster-wide traveling shocks and also drive galaxy evolution. The observable effects of shock waves can be seen at radio wavelengths as relics: elongated, diffuse synchrotron emitting areas located at the periphery of merging clusters. Despite the great interest in relics, candidates with simple geometry, undisturbed morphology and high surface brightness are scarce. The `Sausage' cluster hosts an extraordinary Mpc-wide relic, which enables us to study to study particle acceleration and the effects of shocks on cluster galaxies. We use a unique combination of facilities (INT, WHT, Keck, Subaru, CFHT, GMRT, WSRT, AMI) to obtain the first cluster-wide, multi-wavelength, multi-method analysis aimed at giving a complete picture of a merging cluster with relics. Using the radio data, we derive shock properties and the magnetic field structure for the relic. Using spectral modeling, we test acceleration and electron energy-loss mechanisms and resolve the discrepancy between the Mach number calculated from the radio and X-rays. Our results indicate that particles are shock-accelerated, but turbulent re-acceleration or unusually efficient transport of particles in the downstream area and line-of-sight mixing are important effects. We demonstrate the feasibility of high-frequency observations of radio relics, by presenting a 16 GHz detection of the `Sausage' relic. The radio analysis is complemented by Hα mapping of the cluster volume, aimed at providing the first direct test as to whether the shock drives or prohibits star formation. We find numerous Hα emitting galaxies in close proximity to the radio relic which are extremely massive, metal-rich, mostly star-forming with evidence for gas mass loss though outflows. We speculate that the complex interaction

  13. Investigation of Controlling Factors Impacting Water Quality in Shale Gas Produced Brine

    NASA Astrophysics Data System (ADS)

    Fan, W.; Hayes, K. F.; Ellis, B. R.

    2014-12-01

    The recent boom in production of natural gas from unconventional reservoirs has generated a substantial increase in the volume of produced brine that must be properly managed to prevent contamination of fresh water resources. Produced brine, which includes both flowback and formation water, is often highly saline and may contain elevated concentrations of naturally occurring radioactive material and other toxic elements. These characteristics present many challenges with regard to designing effective treatment and disposal strategies for shale gas produced brine. We will present results from a series of batch experiments where crushed samples from two shale formations in the Michigan Basin, the Antrim and Utica-Collingwood shales, were brought into contact with synthetic hydraulic fracturing fluids under in situ temperature and pressure conditions. The Antrim has been an active shale gas play for over three decades, while the Utica-Collingwood formation (a grouped reservoir consisting of the Utica shale and Collingwood limestone) is an emerging shale gas play. The goal of this study is to investigate the influence of water-rock interactions in controlling produced water quality. We evaluate toxic element leaching from shale samples in contact with model hydraulic fracturing fluids under system conditions corresponding to reservoir depths up to 1.5 km. Experimental results have begun to elucidate the relative importance of shale mineralogy, system conditions, and chemical additives in driving changes in produced water quality. Initial results indicate that hydraulic fracturing chemical additives have a strong influence on the extent of leaching of toxic elements from the shale. In particular, pH was a key factor in the release of uranium (U) and divalent metals, highlighting the importance of the mineral buffering capacity of the shale. Low pH values persisted in the Antrim and Utica shale experiments and resulted in higher U extraction efficiencies than that

  14. Impacts of prescribed burning on soil greenhouse gas fluxes in a suburban native forest of south-eastern Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Wang, Y. Z.; Xu, Z. H.; Fu, L.

    2015-07-01

    Prescribed burning is a forest management practice that is widely used in Australia to reduce the risk of damaging wildfires. It can affect both carbon (C) and nitrogen (N) cycling in the forest and thereby influence the soil-atmosphere exchange of major greenhouse gases, i.e. carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). To quantify the impact of a prescribed burning (conducted on 27 May 2014) on greenhouse gas exchange and the potential controlling mechanisms, we carried out a series of field measurements before (August 2013) and after (August 2014 and November 2014) the fire. Gas exchange rates were determined at 4 replicate sites which were burned during the combustion and another 4 adjacent unburned sites located in green islands, using a set of static chambers. Surface soil properties including temperature, pH, moisture, soil C and N pools were also determined either by in situ measurement or by analysing surface 10 cm soil samples. All of the chamber measurements indicated a net sink of atmospheric CH4, with mean CH4 uptake ranging from 1.15 to 1.99 mg m-2 day-1. The burning significantly enhanced CH4 uptake as indicated by the significant higher CH4 uptake rates at the burned sites measured in August 2014. While within the next 3 months the CH4 uptake rate was recovered to pre-burning levels. Mean CO2 emission from forest soils ranged from 2721.76 to 7113.49 mg m-2 day-1. The effect of prescribed burning on CO2 emission was limited within the first 3 months, as no significant difference was observed between the burned and the adjacent unburned sites in both August and November 2014. The temporal dynamics of the CO2 emission presented more seasonal variations, rather than burning effects. The N2O emission at the studied sites was quite low, and no significant impact of burning was observed. The changes in understory plants and litter layers, surface soil temperature, C and N substrate availability and microbial activities, resulting from the

  15. Impact of postconsumer recycling initiatives on industrial energy demand-opportunities and threats for natural gas. Final report, December 1991-June 1993

    SciTech Connect

    Artz, N.; Kinkelaar, M.; Kirk, M.

    1993-01-01

    The rapid change in municipal solid waste and industrial waste management practices in the U.S. could have significant impact on industrial energy demand and ultimately, natural gas demand. The study examines the impact of increased rates of postconsumer recycling and waste used as fuel on industrial natural gas demand for the time period 1990 to 2005. Increased postconsumer recycling and waste used as fuel are projected to decrease natural gas demand in the U.S. by 29 trillion Btu per year by 1995 and over 71 trillion Btu by 2005. Increased ferrous scrap use in electric are furnaces and postconsumer plastics recycling are projected to cause the most significant loss in natural gas demand.

  16. Quantifying the impact of nitric oxide calibration gas mixture oxidation on reported nitrogen dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Sweeney, Bryan P.; Quincey, Paul G.; Green, David; Fuller, Gary W.

    2015-03-01

    Chemiluminescent analysers for measuring nitric oxide (NO) and nitrogen dioxide (NO2) in ambient air are generally calibrated with certified gas standard cylinders of NO in nitrogen. Verification of the NOx and NO amount fractions has been carried out on many such 'on-site' calibration cylinders at air quality monitoring stations. These measurements indicate that significant numbers of these gas mixtures have become somewhat degraded, with several percent of the NO oxidised to NO2. The effect of not compensating for this degradation on reported concentrations is discussed. If such degradation is not quantified and corrected for, there will be a systematic under-reporting of NO2 concentrations, which, due to the non-linearity of the effect, could reduce high reported NO2 concentrations at kerbside sites by around 20%. This could significantly reduce the number of reported exceedances of the NO2 limit value at such sites, compared to results obtained where there is no degradation of the NO cylinder.

  17. The impact of emissions standards on the design of aircraft gas turbine engine combustors

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.

    1976-01-01

    Effective emission control techniques have been identified and a wide spectrum of potential applications for these techniques to existing and advanced engines are being considered. Results from advanced combustor concept evaluations and from fundamental experiments are presented and discussed and comparisons are made with existing EPA emission standards and recommended levels for high altitude cruise. The impact that the advanced low emission concepts may impose on future aircraft engine combustor designs and related engine components is discussed.

  18. Noble Gas and Mineralogical Tracers of Interplanetary Dust Particles and Impact Debris in a Central Pacific Sediment Core

    NASA Astrophysics Data System (ADS)

    Darrah, T. H.; Poreda, R. J.

    2005-12-01

    Thirty-five deep ocean sediment samples from the Central Pacific sediment core LL-44 GPC-3 were examined for their noble gas composition and mineralogy. The samples spanned from 30 to 71 Ma in age, including the Cretaceous/Tertiary (K/T), Paleocene/Eocene (P/E), and Eocene/Oligocene (E/O) boundaries. From each bulk sediment sample, magnetic grains (5-200 μg/g; 1-20 μm diameter) were isolated and analyzed. Noble gas measurements determined the helium and neon isotopic compositions and the abundance of extra-terrestrial (ET) noble gases for the bulk and magnetic fractions. 3He/4He ratios of 3.1x10-4 and 20Ne/22Ne ratios of 9.96-12.62 are consistent with the SEP (solar energetic particle) signature seen in both zero-age magnetic grains (Z-MAG) from the central Pacific sediments and stratospheric interplanetary dust particles (IDPs). The isolated magnetic fraction typically consisted of less than 1% of the bulk sample while accounting for 3 to 10% of the bulk sediment 3He with a maximum of 40% at K/T boundary. The magnetic isolates revealed no significant differences of 3He/4He, 20Ne/22Ne, or (3He/20Ne)solar from the bulk GPC-3 sediments or Z-MAG grains. No temporal variation in He or Ne or anomalous gas signatures associated with the boundaries present within this time interval was observed. Scanning electron microscope analysis was utilized to determine the mineralogy of the magnetic isolates in an effort to distinguish between the continuous flux of interplanetary dust particles and the flux associated with major impact events. This information may also assist in determining the carrier phase of ET noble gases. Anomalously high Ni, Mg, Al, and Cr compositions combined with low or nonexistent abundances of titanium can distinguish extraterrestrial spinel grains from terrestrial spinel. The SEM analysis revealed stark contrasts in composition and morphology in the samples associated with the boundaries included in this study. A survey of ``background'' samples

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  20. Use of the Edmonds-Reilly Model to model energy-sector impacts of greenhouse gas emissions control strategies

    SciTech Connect

    Barns, D.W.; Edmonds, J.A.; Reilly, J.M.

    1992-01-01

    The purpose of this paper is to document the results of our application of the Edmonds-Reilly Model (ERM) using several scenarios provided in connection with the 1991 Energy Modeling Forum (EMF). The purpose of this session of the forum is to compare the efforts of several modeling teams using common assumptions to examine the energy sector impacts of strategies to control greenhouse gas emissions. Because the output of this exercise is data-rich, most of this exposition is in graphical form with the narrative serving mainly as a roadmap for moving from one highlight to the next. The following sessions briefly describe the model and some of the special modifications made for this effort. The case-by-case discussion is contained in Section IV, followed by a summary of the potential pitfalls involved in attempting to assess the cost of emissions reduction from the model data.

  1. Assessing environmental impact from gas and oil exploration in the SW Barents Sea using benthic foraminiferal assemblages

    NASA Astrophysics Data System (ADS)

    Dijkstra, N.; Junttila, J.; Husum, K.; Carroll, J.; Hald, M.

    2012-04-01

    During the last decades petroleum industry and shipping activities have increased in the SW Barents Sea. Oil exploration wells were drilled in the 1980s with production starting in 2007. These activities are projected to expand in the coming years. As part of the Northern Environmental Waste Management (EWMA) project, a competence cluster for petroleum industry related waste handling, we investigate the impacts of enhanced anthropogenic activities on benthic foraminiferal assemblages in the SW Barents Sea. Sediment cores (0-20 cm) from sites in proximity to two oil- and gas fields are under investigation. These sediment cores, dated with the 210Pb method, represent the last 90 to 150 years. Both dead and living benthic foraminifera (100 µm-1 mm) were counted to elucidate differences in foraminiferal assemblages between pre-impact and recent conditions. In addition, the heavy metal concentrations, persistent organic pollutant (POP) concentrations, grain size and total organic content (TOC) of the sediment cores have been analyzed. Pollution levels of the surface sediments (0-1 cm) are of background to good level (level I-II) according to the definitions of the Water Framework Directorate (WFD). Patterns in living benthic foraminiferal assemblages identified in the sea floor surface sediments, are the result of natural environmental changes such as depth, water mass and sediment composition. Further downcore (1-20 cm) pollution levels are in general of background environmental status (WFD level I). However, at some depth intervals, especially in sediment cores from the near proximity of the oil- and gas- fields, pollution levels are slightly enhanced (WFD level II). Further work will include statistical comparison of dead and living foraminiferal assemblages with sediment pollution levels, sediment properties, and oceanographic conditions. This research contributes to the development of foraminifera as a useful bio-monitoring technique for the Arctic region as

  2. Impact of Pharmaceutical Impurities in Ecstasy Tablets: Gas Chromatography-Mass Spectrometry Study.

    PubMed

    Jalali, Amir; Hatamie, Amir; Saferpour, Tahere; Khajeamiri, Alireza; Safa, Tahere; Buazar, Foad

    2016-01-01

    In this study, a simple and reliable method by gas chromatograph-mass spectrometry (GC-MS) was developed for the fast and regular identification of 3, 4-MDMA impurities in ecstasy tablets. In so doing, 8 samples of impurities were extracted by diethyl ether under alkaline condition and then analyzed by GC-MS. The results revealed high MDMA levels ranging from 37.6% to 57.7%. The GC-MS method showed that unambiguous identification can be achieved for MDMA from 3, 4-methylenedioxyamphetamine (MDA), Amphetamine (AM), methamphetamine (MA) and ketamine (Keta) compounds, respectively. The experimental results indicated the acceptable time window without interfering peaks. It is found that GC-MS was provided a suitable and rapid identification approach for MDMA (Ecstacy) tablets, particularly in the Forensic labs. Consequently, the intense MDMA levels would support the police to develop a simple quantification of impurity in Ecstasy tablets. PMID:27610162

  3. Impact of Pharmaceutical Impurities in Ecstasy Tablets: Gas Chromatography-Mass Spectrometry Study

    PubMed Central

    Jalali, Amir; Hatamie, Amir; Saferpour, Tahere; Khajeamiri, Alireza; Safa, Tahere; Buazar, Foad

    2016-01-01

    In this study, a simple and reliable method by gas chromatograph–mass spectrometry (GC–MS) was developed for the fast and regular identification of 3, 4-MDMA impurities in ecstasy tablets. In so doing, 8 samples of impurities were extracted by diethyl ether under alkaline condition and then analyzed by GC–MS. The results revealed high MDMA levels ranging from 37.6% to 57.7%. The GC-MS method showed that unambiguous identification can be achieved for MDMA from 3, 4-methylenedioxyamphetamine (MDA), Amphetamine (AM), methamphetamine (MA) and ketamine (Keta) compounds, respectively. The experimental results indicated the acceptable time window without interfering peaks. It is found that GC-MS was provided a suitable and rapid identification approach for MDMA (Ecstacy) tablets, particularly in the Forensic labs. Consequently, the intense MDMA levels would support the police to develop a simple quantification of impurity in Ecstasy tablets. PMID:27610162

  4. Volcanic gas emissions from Mount Erebus and their impact on the Antarctic environment

    SciTech Connect

    Zreda-Gostynska, G.; Kyle, P.R.; Finnegan, D.; Prestbo, K.M.

    1997-07-01

    Emission rates of SO{sub 2}, HCl, and HF from the active volcano Mount Erebus, Antarctica, increased between 1986 and 1991; SO{sub 2} from 7.7 to 25.9Ggyr{sup {minus}1}, HCl from 6.9 to 13.3Ggyr{sup {minus}1} and HF from 4.0 to 6.0Ggyr{sup {minus}1}. The emission rates of halogens from Mount Erebus are high relative to SO{sub 2} emissions and are accompanied by relatively high emissions of trace gases and aerosols (Na, K, As, Zn, In, As, Se, and Au). Many elements (S, Cl, and metals) found in the Erebus plume are common impurities in Antarctic snow. Using a model which assumes a homogeneous distribution of the volcanic gas plume over Antarctica, we suggest that Erebus could be a source of the impurities. We calculate that Erebus could potentially contribute between 4 and 14ngg{sup {minus}1} snow of Cl at the south pole, and between 11 and 36ngg{sup {minus}1} snow of Cl at Dome C. Excess Cl (Cl in excess of that derived from marine NaCl aerosols) recorded in snow and firn cores from south pole and Dome C could be mainly derived from Erebus. Similarly, our predicted concentrations of Erebus-derived Cu, Zn, Cd, V, As, and Au in Antarctic snow are close to those reported. Trace element and Pb isotope compositions of Erebus aerosols are similar to those collected in remote regions of Antarctica. The volcanic gas plume emitted from Erebus appears to make a significant contribution to the Antarctic atmosphere and can be detected in the snow deposited over a wide area of the continent.{copyright} 1997 American Geophysical Union

  5. Landscape geomorphic characteristic impacts on greenhouse gas fluxes in exposed stream and riparian sediments.

    PubMed

    Vidon, Philippe; Serchan, Satish

    2016-07-13

    While excessive releases of greenhouse gases (GHG: N2O, CO2, CH4) to the atmosphere due to the burning of fossil fuel remains a concern, we also need to better quantify GHG emissions from natural systems. This study investigates GHG fluxes at the soil-atmosphere interface in a series of 7 stream reaches (riparian zones + exposed streambed sediment) across a range of geomorphic locations from headwaters reaches to lowland wetland reaches. When riparian fluxes (RZ) are compared to fluxes from in-stream locations (IS) under summer baseflow conditions, total CO2-equivalent (CO2eq) emissions are approximately 5 times higher at RZ locations than at IS locations, with most CO2eq driven by CH4 production at RZ locations where wet conditions dominate (headwater wetlands, lowland wetlands). On a gas-by-gas basis, no clear differences in N2O fluxes between RZ and IS locations were observed regardless of locations (headwater vs. lowland reaches), while CO2 fluxes were significantly larger at RZ locations than IS locations. Methane fluxes were significantly higher in wetland-influenced reaches than other reaches for both RZ and IS locations. However, GHG fluxes were not consistently correlated to DOC, DO, NO3(-), NH4(+), or water temperature, stressing the limitations of using water quality parameters to predict GHG emissions at the floodplain scale, at least during summer baseflow conditions. As strategies are developed to further constrain GHG emission for whole watersheds, we propose that approaches linking landscape geomorphic characteristics to GHG fluxes at the soil-atmosphere interface offer a promising avenue to successfully predict GHG emissions in floodplains at the watershed scale. PMID:27306099

  6. Volcanic gas emissions from Mount Erebus and their impact on the Antarctic environment

    NASA Astrophysics Data System (ADS)

    Zreda-Gostynska, Grazyna; Kyle, Philip R.; Finnegan, D.; Prestbo, Kimberly Meeker

    1997-07-01

    Emission rates of SO2, HCl, and HF from the active volcano Mount Erebus, Antarctica, increased between 1986 and 1991; SO2 from 7.7 to 25.9 Gg yr-1, HCl from 6.9 to 13.3 Gg yr-1 and HF from 4.0 to 6.0 Gg yr-1. The emission rates of halogens from Mount Erebus are high relative to SO2 emissions and are accompanied by relatively high emissions of trace gases and aerosols (Na, K, As, Zn, In, As, Se, and Au). Many elements (S, Cl, and metals) found in the Erebus plume are common impurities in Antarctic snow. Using a model which assumes a homogeneous distribution of the volcanic gas plume over Antarctica, we suggest that Erebus could be a source of the impurities. We calculate that Erebus could potentially contribute between 4 and 14 ng g-1 snow of Cl at the south pole, and between 11 and 36 ng g-1 snow of Cl at Dome C. Excess Cl (Cl in excess of that derived from marine NaCl aerosols) recorded in snow and firn cores from south pole and Dome C could be mainly derived from Erebus. Similarly, our predicted concentrations of Erebus-derived Cu, Zn, Cd, V, As, and Au in Antarctic snow are close to those reported. Trace element and Pb isotope compositions of Erebus aerosols are similar to those collected in remote regions of Antarctica. The volcanic gas plume emitted from Erebus appears to make a significant contribution to the Antarctic atmosphere and can be detected in the snow deposited over a wide area of the continent.

  7. Cellulosic ethanol from municipal solid waste: a case study of the economic, energy, and greenhouse gas impacts in California.

    PubMed

    Chester, Mikhail; Martin, Elliot

    2009-07-15

    As cellulosic ethanol technologies advance, states could use the organic content of municipal solid waste as a transportation fuel feedstock and simultaneously reduce externalities associated with waste disposal. We examine the major processes required to support a lignocellulosic (employing enzymatic hydrolysis) municipal solid waste-to-ethanol infrastructure computing cost, energy, and greenhouse gas effects for California. The infrastructure is compared against the Business As Usual case where the state continues to import most of its ethanol needs from the Midwest. Assuming between 60% and 90% practical yields for ethanol production, California could produce between 1.0 and 1.5 billion gallons per year of ethanol from 55% of the 40 million metric tonnes of waste currently sent to landfills annually. The classification of organic wastes and ethanol plant operation represent almost the entire system cost (between $3.5 and $4.5 billion annually) while distribution has negligible cost effects and savings from avoided landfilling is small. Fossil energy consumption from Business As Usual decreases between 82 and 130 PJ largely due to foregone gasoline consumption. The net greenhouse gas impacts are ultimately dependent on how well landfills control their emissions of decomposing organics. Based on the current landfill mix in the state, the cellulosic infrastructure would experience a slight gain in greenhouse gas emissions. However, net emissions can rise if organics diversion releases carbon that would otherwise be flared and sequestered. Emissions would be avoided if landfills are not capable of effectively controlling emissions during periods of active waste decay. There is currently considerable uncertainty surrounding the recovery efficiency of landfill emissions controls. In either case, burying lignin appears to be better than burning lignin because of its decay properties, energy and carbon content We estimate the breakeven price for lignocellulosic ethanol

  8. Free and Forced Convection in High Permeability Porous Media: Impact on Gas Flux at the Earth-atmosphere Interface

    NASA Astrophysics Data System (ADS)

    Weisbrod, N.; Levintal, E.; Dragila, M. I.; Kamai, T.

    2015-12-01

    Gas movement within the earth's subsurface and its exchange with the atmosphere is one of the principal elements contributing to soil and atmospheric function. As the soil permeability increases, gas circulation by convective mechanisms becomes significantly greater than the diffusion. Two of the convective mechanisms, which can be of great importance, are being explored in this research. The first one is thermal convection venting (TCV), which develops when there are unstable density gradients. The second mechanism is wind induced convection (WIC), which develops due to surface winds that drive air movement. Here, we report the results of a study on the relationships between the porous media permeability and particle size, and the development and magnitude of TCV and WIC with the development of thermal differences and surface winds. The research included large high-permeability column experiments carried out under highly controlled laboratory conditions, using well-defined single-sized spherical particles while surface winds and thermal differences were forced and monitored. CO2 enriched air, functioned as a tracer, was used to quantify the impact of TCV and WIC on gas migration in the porous media. Results show that in homogenous porous media a permeability range of 10-7 to 10-6 m2 is the threshold value for TCV onset under standard atmospheric conditions. Adding surface wind with an average velocity of 1.5 m s-1 resulted in WIC effect to a depth of -0.3 m in most experimental settings; however, it did not caused additional air circulation at the reference depth of -0.9 m. Furthermore, given the appropriate conditions, a combined effect of TCV and WIC did significantly increase the overall media ventilation. Simulations of temperature profiles in soil under that permeability, showed that as the thermal gradient changes with depth and is a continuous function, TCV cells can be developed in local sections of the profile, not necessarily reaching the atmosphere.

  9. A dynamic approach for the impact of a toxic gas dispersion hazard considering human behaviour and dispersion modelling.

    PubMed

    Lovreglio, Ruggiero; Ronchi, Enrico; Maragkos, Georgios; Beji, Tarek; Merci, Bart

    2016-11-15

    The release of toxic gases due to natural/industrial accidents or terrorist attacks in populated areas can have tragic consequences. To prevent and evaluate the effects of these disasters different approaches and modelling tools have been introduced in the literature. These instruments are valuable tools for risk managers doing risk assessment of threatened areas. Despite the significant improvements in hazard assessment in case of toxic gas dispersion, these analyses do not generally include the impact of human behaviour and people movement during emergencies. This work aims at providing an approach which considers both modelling of gas dispersion and evacuation movement in order to improve the accuracy of risk assessment for disasters involving toxic gases. The approach is applied to a hypothetical scenario including a ship releasing Nitrogen dioxide (NO2) on a crowd attending a music festival. The difference between the results obtained with existing static methods (people do not move) and a dynamic approach (people move away from the danger) which considers people movement with different degrees of sophistication (either a simple linear path or more complex behavioural modelling) is discussed. PMID:27343142

  10. Mechanism of charge transfer and its impacts on Fermi-level pinning for gas molecules adsorbed on monolayer WS2.

    PubMed

    Zhou, Changjie; Yang, Weihuang; Zhu, Huili

    2015-06-01

    Density functional theory calculations were performed to assess changes in the geometric and electronic structures of monolayer WS2 upon adsorption of various gas molecules (H2, O2, H2O, NH3, NO, NO2, and CO). The most stable configuration of the adsorbed molecules, the adsorption energy, and the degree of charge transfer between adsorbate and substrate were determined. All evaluated molecules were physisorbed on monolayer WS2 with a low degree of charge transfer and accept charge from the monolayer, except for NH3, which is a charge donor. Band structure calculations showed that the valence and conduction bands of monolayer WS2 are not significantly altered upon adsorption of H2, H2O, NH3, and CO, whereas the lowest unoccupied molecular orbitals of O2, NO, and NO2 are pinned around the Fermi-level when these molecules are adsorbed on monolayer WS2. The phenomenon of Fermi-level pinning was discussed in light of the traditional and orbital mixing charge transfer theories. The impacts of the charge transfer mechanism on Fermi-level pinning were confirmed for the gas molecules adsorbed on monolayer WS2. The proposed mechanism governing Fermi-level pinning is applicable to the systems of adsorbates on recently developed two-dimensional materials, such as graphene and transition metal dichalcogenides. PMID:26049513

  11. Low temperature impact toughness of the main gas pipeline steel after long-term degradation

    NASA Astrophysics Data System (ADS)

    Maruschak, Pavlo O.; Danyliuk, Iryna M.; Bishchak, Roman T.; Vuherer, Tomaž

    2014-12-01

    The correlation of microstructure, temperature and Charpy V-notch impact properties of a steel 17G1S pipeline steel was investigated in this study. Within the concept of physical mesomechanics, the dynamic failure of specimens is represented as a successive process of the loss of shear stability, which takes place at different structural/scale levels of the material. Characteristic stages are analyzed for various modes of failure, moreover, typical levels of loading and oscillation periods, etc. are determined. Relations between low temperature derived through this test, microstructures and Charpy (V-notch) toughness test results are also discussed in this paper.

  12. European greenhouse gas fluxes from land use: the impact of expanding the use of dedicated bioenergy crops.

    NASA Astrophysics Data System (ADS)

    Hastings, Astley; Böttcher, Hannes; Clifton-Brown, John; Fuchs, Richard; Hillier, Jon; Jones, Ed; Obersteiner, Michael; Pogson, Mark; Richards, Mark; Smith, Pete

    2013-04-01

    Bioenergy derived from vegetation cycles carbon to and from the atmosphere using the chemical energy fixed by the plants by photosynthesis using solar energy. However bioenergy is not carbon neutral as energy is used and greenhouse gasses (GHG) are emitted in the process of growing bioenergy feeedstocks and processing them into a usable fuel, whether it is biomass or liquid fuel such as biodiesel or bioethanol. Using bio instead of fossil fuels replaces greenhouse gas emissions from coal, oil and gas by those of the biofuel. To estimate the impact on European greenhouse gas fluxes of expanding the use of bioenergy, it is necessary to quantify the difference between the GHG emissions associated with producing and using the biofuel and the fossil fuel it replaces, and to take into account any emissions associated with the change from the original land use to that of growing the bioenergy feedstock. This involves estimating any displacement of food, fibre and timber production to other geographical areas. Here we report on a study of the GHG emissions from the potential increasing use of a variety of biofuels produced from feedstocks grown in the EU countries. The GHG emissions of the historical land use of EU27 have been modelled using ECOSSE on a 1 km grid to estimate the impact the agriculture intensification and land use change of the last 50 years and the associated crop yield gains. The excess land made available from the yield gains is considered to be available for use for bioenergy, and the yields of potential bioenergy feedstocks are estimated from EUROSTAT data or modelled using the bioenergy crop growth model MISCANFOR. These yields are used to calculate the energy used and GHG emissions associated with the use of the resulting biofuel using a life cycle analysis, and to estimate the organic matter input into the soil. The ECOSSE model is then used to estimate the soil carbon change and GHG emissions associated with the land use change to growing the

  13. The relative impacts of greenhouse gas and aerosol climate forcing on mountain glacier melt at the third pole

    NASA Astrophysics Data System (ADS)

    Wilcox, E. M.

    2010-12-01

    The third pole region resides within a hot spot for atmospheric brown clouds owing to the widespread emissions of dust, soot, and organic carbon aerosols in South and East Asia. As much as one-half of the regional climate warming over South Asia in the later 20th and early 21st centuries has been attributed to the direct radiative heating of the troposphere by aerosol solar absorption. The other half is attributed to the global greenhouse gas forcing. While the increase in temperature and infrared back radiation attributable to greenhouse gas warming is expected to accelerate melting of Himalayan glaciers, aerosol radiative forcing, and the climate response to it, contribute a host of additional impacts on mountain glaciers, many of which exacerbate the melting. These impacts include atmospheric warming, increased infrared back radiation, reduced surface insolation, surface albedo modification by soot deposition, and reductions in monsoon precipitation. The contributions of each of these effects upon melting of Himalayan mountain glaciers is explored in a glacier mass model based on energy balance calculations. The surface energy balance from the base to the top of several glaciers is calculated based on remote sensing and in-situ time series of radiative fluxes and precipitation. The model is calibrated against recent in-situ measurements of glacier mass balance and equilibrium altitude where available. Perturbations to the radiative fluxes and precipitation are then imposed on the mass balance calculations based on published estimates of the aerosol radiative forcing magnitudes and observed changes in regional temperature and precipitation over the modern era. In light of the substantial uncertainty surrounding regional forcing values and mountain glacier characteristics, the study emphasizes sensitivity studies comparing the relative responses of glaciers to the components of aerosol and greenhouse gas forcing mentioned above. Of particular interest are: (a) the

  14. The Impacts of Changes in Snowfall on Soil Greenhouse Gas Emissions Using an Automated Chamber System

    NASA Astrophysics Data System (ADS)

    Ruan, L.; Kahmark, K.; Robertson, G.

    2012-12-01

    Snow cover has decreased in many regions of the northern hemisphere and is projected to decrease further in most. The reduced snow cover may enhance soil freezing and increase the depth of frost. The frequency of freeze-thaw cycles is likely to increase due to the reduction of snowpack thickness. Freeze and thaw cycles can strongly affect soil C and N dynamics. The pulses of N2O and CO2 emissions from soil after thawing have been reported in various studies. However, most studies were based on the controlled laboratory conditions or low resolution static chamber methods in situ. Near-continuous automated chambers provide the temporal resolution needed for capturing short-lived pulses of greenhouse gases after intermittent melting events. We investigated the winter and spring response of soil greenhouse gas emissions (CO2, CH4 and N2O) to changes of snow depth using an automated chamber system. This study was established in 2010 at the Kellogg Biological Station (KBS) in southwest Michigan. The plot was no till rotational (corn-soybean-wheat) cropland, most recently in corn. The experiment was a completely randomized design (CRD) with three levels of snow depth: ambient, double, and no snow. Each level had four replicates. Twelve automated chambers were randomly assigned to treatments and greenhouse gas fluxes measured 4 times per day in each plot. There were more freeze-thaw cycles in the no snow treatment than in the ambient and double snow treatments. Soil temperature at 5 cm depth was more variable in the no snow treatment than in the ambient and double snow treatments. CH4 fluxes were uniformly low with no significant difference across three treatments. CO2 showed expected seasonal changes with the highest emission in spring and lowest emissions through the winter. N2O peaks were higher in spring due to freeze thaw effects and cumulative N2O fluxes were substantially higher in the no snow treatment than in the ambient and double snow treatments.

  15. Water Resource Impacts During Unconventional Shale Gas Development: The Pennsylvania Experience

    NASA Astrophysics Data System (ADS)

    Brantley, S. L.; Yoxtheimer, D.; Arjmand, S.; Grieve, P.; Vidic, R.; Abad, J. D.; Simon, C. A.; Pollak, J.

    2013-12-01

    The number of unconventional Marcellus shale wells in PA has increased from 8 in 2005 to more than 6000 today. This rapid development has been accompanied by environmental issues. We analyze publicly available data describing this Pennsylvania experience (data from www.shalenetwork.org and PA Department of Environmental Protection, i.e., PA DEP). After removing permitting and reporting violations, the average percent of wells/year with at least one notice of violation (NOV) from PA DEP is 35 %. Most violations are minor. An analysis of NOVs reported for wells drilled before 2013 revealed a rate of casing, cement, or well construction issues of 3.4%. Sixteen wells were given notices specifically related to migration of methane. A similarly low percent of wells were contaminated by brine components. Such contamination could derive from spills, subsurface migration of flowback water or shallow natural brines, or contamination by drill cuttings. Most cases of contamination of drinking water supplies with methane or brine components were reported in the previously glaciated part of the state. Before 2011, flowback and production water was often discharged legally into streams after minimal treatment, possibly increasing dissolved Br concentrations in some rivers. The rate of large spills or releases of gas-related industrial wastes in the state peaked in 2009 but little evidence of spills has been found in publicly available surface water chemistry data. The most likely indicators of spillage or subsurface release of flowback or production waters are the dissolved ions Na, Ca, and Cl. However, the data coverage for any given analyte is generally spatially and temporally sparse. Publicly available water quality data for before and after spills into Larrys Creek and Bobs Creek document the difficulties of detecting such events. An observation from the Pennsylvania experience is that the large number of people who have complained about their water supply (~1000 letters

  16. Greenhouse gas exchange in grasslands: impacts of climate, intensity of management and other factors

    NASA Astrophysics Data System (ADS)

    Smith, K. A.

    2003-04-01

    Grasslands occupy some 40% of the terrestrial land surface. They are generally categorised as natural (occurring mainly in those regions where the rainfall is too low to support forest ecosystems), semi-natural (where management, mainly by grazing, has changed the vegetation composition), and artificial (where forests have been cleared to create new pasture land). The soils of the natural and semi-natural grasslands constitute a large reservoir of carbon, and make a substantial contribution to the soil sink for atmospheric CH_4. The conversion of much of the natural temperate grassland to arable agriculture, e.g. in North America and Europe, resulted in a considerable decrease in soil organic carbon, and its release to the atmosphere as CO_2 has made a substantial contribution to the total atmospheric concentration of this gas. The associated increase in cycling of soil N (released from the organic matter) will have contributed to N_2O emissions, and land disturbance and fertilisation has resulted in a depletion of the soil CH_4 sink. Conversion of tropical forests to pastures has also been a major source of CO_2, and these pastures show elevated emissions of N_2O for some years after conversion. Seasonally flooded tropical grasslands are a significant source of CH_4 emissions. Consideration of grassland ecosystems in their entirety, in relation to GHG exchange, necessitates the inclusion of CH_4 production by fauna - domesticated livestock and wild herbivores, as well as some species of termites - in the overall assessment. Stocking rates on pasture land have increased, and the total CH_4 emissions likewise. The relationship between animal production and CH_4 emissions is dependent on the nutritional quality of the vegetation, as well as on animal numbers. In both temperate and tropical regions, increased N inputs as synthetic fertilisers and manures (and increased N deposition) are producing possibly a more-than-linear response in terms of emissions of N_2O. In

  17. Wastewater treatment process impact on energy savings and greenhouse gas emissions.

    PubMed

    Mamais, D; Noutsopoulos, C; Dimopoulou, A; Stasinakis, A; Lekkas, T D

    2015-01-01

    The objective of this research was to assess the energy consumption of wastewater treatment plants (WWTPs), to apply a mathematical model to evaluate their carbon footprint, and to propose energy saving strategies that can be implemented to reduce both energy consumption and greenhouse gas (GHG) emissions in Greece. The survey was focused on 10 WWTPs in Greece with a treatment capacity ranging from 10,000 to 4,000,000 population equivalents (PE). Based on the results, annual specific energy consumption ranged from 15 to 86 kWh/PE. The highest energy consumer in all the WWTPs was aeration, accounting for 40-75% of total energy requirements. The annual GHG emissions varied significantly according to the treatment schemes employed and ranged between 61 and 161 kgCO₂e/PE. The highest values of CO₂emissions were obtained in extended aeration systems and the lowest in conventional activated sludge systems. Key strategies that the wastewater industry could adopt to mitigate GHG emissions are identified and discussed. A case study is presented to demonstrate potential strategies for energy savings and GHG emission reduction. Given the results, it is postulated that the reduction of dissolved oxygen (DO) set points and sludge retention time can provide significant energy savings and decrease GHG emissions. PMID:25633956

  18. Impact of rising greenhouse gas concentrations on future tropical ozone and UV exposure

    NASA Astrophysics Data System (ADS)

    Meul, Stefanie; Dameris, Martin; Langematz, Ulrike; Abalichin, Janna; Kerschbaumer, Andreas; Kubin, Anne; Oberländer-Hayn, Sophie

    2016-03-01

    Future projections of tropical total column ozone (TCO) are challenging, as its evolution is affected not only by the expected decline of ozone depleting substances but also by the uncertain increase of greenhouse gas (GHG) emissions. To assess the range of tropical TCO projections, we analyze simulations with a chemistry-climate model forced by three different GHG scenarios (Representative Concentration Pathway (RCP) 4.5, RCP6.0, and RCP8.5). We find that tropical TCO will be lower by the end of the 21st century compared to the 1960s in all scenarios with the largest decrease in the medium RCP6.0 scenario. Uncertainties of the projected TCO changes arise from the magnitude of stratospheric column decrease and tropospheric ozone increase which both strongly vary between the scenarios. In the three scenario simulations the stratospheric column decrease is not compensated by the increase in tropospheric ozone. The concomitant increase in harmful ultraviolet irradiance reaches up to 15% in specific regions in the RCP6.0 scenario.

  19. Gas Gun Impact Testing of PZT 95/5, Part 1: Unpoled State

    SciTech Connect

    FURNISH,MICHAEL D.; SETCHELL,ROBERT E.; CHHABILDAS,LALIT C.; MONTGOMERY,STEPHEN T.

    2000-01-01

    In the present study, 10 impact tests were conducted on unpoled PZT 95/5, with 9% porosity and 2 at% Nb doping. These tests were instrumented to obtain time-resolved loading, unloading and span signatures. As well, PVDF gauges allowed shock timing to be established explicitly. The ferroelectric/antiferroelectric phases transition was manifested as a ramp to 0.4 GPa. The onset of crushup produced the most visible signature: a clear wave separation at 2.2 GPa followed by a highly dispersive wave. The end states also reflected crushup, and are consistent with earlier data and with related poled experiments. A span strength value of 0.17 GPa was measured for a shock stress of 0.5 GPa, this decreased to a very small value (no visible pullback signature) for a shock strength of 1.85 GPa.

  20. Application of nonparametric regression and statistical testing to identify the impact of oil and natural gas development on local air quality

    NASA Astrophysics Data System (ADS)

    Cheng, Hanqi; Small, Mitchell J.; Pekney, Natalie J.

    2015-10-01

    The objective of the current work was to develop a statistical method and associated tool to evaluate the impact of oil and natural gas exploration and production activities on local air quality. Nonparametric regression of pollutant concentrations on wind direction was combined with bootstrap hypothesis testing to provide statistical inference regarding the existence of a local/regional air quality impact. The block bootstrap method was employed to address the effect of autocorrelation on test significance. The method was applied to short-term air monitoring data collected at three sites within Pennsylvania's Allegheny National Forest. All of the measured pollutant concentrations were well below the National Ambient Air Quality Standards, so the usual criteria and methods for data analysis were not sufficient. Using advanced directional analysis methods, test results were first applied to verify the existence of a regional impact at a background site. Next the impact of an oil field on local NOx and SO2 concentrations at a second monitoring site was identified after removal of the regional effect. Analysis of a third site also revealed air quality impacts from nearby areas with a high density of oil and gas wells. All results and conclusions were quantified in terms of statistical significance level for the associated inferences. The proposed method can be used to formulate hypotheses and verify conclusions regarding oil and gas well impacts on air quality and support better-informed decisions for their management and regulation.

  1. Contact lens impact on quality of life in keratoconus patients: rigid gas permeable versus soft silicone-hydrogel keratoconus lenses

    PubMed Central

    Yildiz, Elvin Hatice; Erdurmus, Mesut; Elibol, Emine Savran; Acar, Banu; Vural, Ece Turan

    2015-01-01

    AIM To determine the impact of rigid gas permeable (RGP) and silicone-hydrogel keratoconus lenses on the quality of life (QoL) in keratoconus (KCN) patients using the self-reported results from the Contact Lens Impact on Quality of Life (CLIQ) Questionnaire. METHODS From January 2013 to April 2013, 27 consecutive KCN patients who wore RGP contact lenses (conflexair100 UV KE Zeiss-Wöhlk) or soft silicone-hydrogel contact lenses (SHCLs) for KCN (KeraSoft IC- Bausch&Lomb or Hydrocone Toris K–Swiss lens) completed the CLIQ questionnaire. RESULTS The mean age of 27 patients was 29.6±8.0y. Fifteen patients were RGP user. The groups were comparable with respect to the mean patient age, sex, and mean K values (P=0.1, P=0.8 and P=0.1, respectively). The mean CLIQperson measure was 42.8±5.5 in RGP group and 39.6±5.5 in SHCLs for KCN group (P=0.06). CLIQperson measure was positively correlated with steep K value (r=0.301, P=0.04). When eyes were stratified by visual acuity with contact lenses, the mean CLIQperson measure was 42.01±5.6 in eyes with a visual acuity of 20/20-20/25 (n=44) and 38.4±5.26 in eyes with a visual acuity of 20/32 or less (n=10; P=0.097). CONCLUSION RGP lenses and SHCLs for KCN have similar impact on QoL. PMID:26558228

  2. Impacts from oil and gas produced water discharges on the gulf of Mexico hypoxic zone.

    SciTech Connect

    Parker, M. E.; Satterlee, K.; Veil, J. A.; Environmental Science Division; ExxonMobil Production Co.; Shell Offshore

    2006-01-01

    Shallow water areas of the Gulf of Mexico continental shelf experience low dissolved oxygen (hypoxia) each summer. The hypoxic zone is primarily caused by input of nutrients from the Mississippi and Atchafalaya Rivers. The nutrients stimulate the growth of phytoplankton, which leads to reduction of the oxygen concentration near the sea floor. During the renewal of an offshore discharge permit used by the oil and gas industry in the Gulf of Mexico, the U.S. Environmental Protection Agency (EPA) identified the need to assess the potential contribution from produced water discharges to the occurrence of hypoxia. The EPA permit required either that all platforms in the hypoxic zone submit produced water samples, or that industry perform a coordinated sampling program. This paper, based on a report submitted to EPA in August 2005 (1), describes the results of the joint industry sampling program and the use of those results to quantify the relative significance of produced water discharges in the context of other sources on the occurrence of hypoxia in the Gulf of Mexico. In the sampling program, 16 facilities were selected for multiple sampling - three times each at one month intervals-- and another 34 sites for onetime sampling. The goal of the sampling program was to quantify the sources and amount of oxygen demand associated with a variety of Gulf of Mexico produced waters. Data collected included direct oxygen demand measured by BOD5 (5-day biochemical oxygen demand) and TOC (total organic carbon) and indirect oxygen demand measured by nitrogen compounds (ammonia, nitrate, nitrate, and TKN [total Kjeldahl nitrogen]) and phosphorus (total phosphorus and orthophosphate). These data will serve as inputs to several available computer models currently in use for forecasting the occurrence of hypoxia in the Gulf of Mexico. The output of each model will be compared for consistency in their predictions and then a semi-quantitative estimate of the relative significance of

  3. Greenhouse gas emissions from MSW incineration in China: impacts of waste characteristics and energy recovery.

    PubMed

    Yang, Na; Zhang, Hua; Chen, Miao; Shao, Li-Ming; He, Pin-Jing

    2012-12-01

    Determination of the amount of greenhouse gas (GHG) emitted during municipal solid waste incineration (MSWI) is complex because both contributions and savings of GHGs exist in the process. To identify the critical factors influencing GHG emissions from MSWI in China, a GHG accounting model was established and applied to six Chinese cities located in different regions. The results showed that MSWI in most of the cities was the source of GHGs, with emissions of 25-207 kg CO(2)-eq t(-1) rw. Within all process stages, the emission of fossil CO(2) from the combustion of MSW was the main contributor (111-254 kg CO(2)-eq t(-1) rw), while the substitution of electricity reduced the GHG emissions by 150-247 kg CO(2)-eq t(-1) rw. By affecting the fossil carbon content and the lower heating value of the waste, the contents of plastic and food waste in the MSW were the critical factors influencing GHG emissions of MSWI. Decreasing food waste content in MSW by half will significantly reduce the GHG emissions from MSWI, and such a reduction will convert MSWI in Urumqi and Tianjin from GHG sources to GHG sinks. Comparison of the GHG emissions in the six Chinese cities with those in European countries revealed that higher energy recovery efficiency in Europe induced much greater reductions in GHG emissions. Recovering the excess heat after generation of electricity would be a good measure to convert MSWI in all the six cities evaluated herein into sinks of GHGs. PMID:22796016

  4. Greenhouse gas emissions from MSW incineration in China: Impacts of waste characteristics and energy recovery

    SciTech Connect

    Yang Na; Zhang Hua; Chen Miao; Shao Liming; He Pinjing

    2012-12-15

    Determination of the amount of greenhouse gas (GHG) emitted during municipal solid waste incineration (MSWI) is complex because both contributions and savings of GHGs exist in the process. To identify the critical factors influencing GHG emissions from MSWI in China, a GHG accounting model was established and applied to six Chinese cities located in different regions. The results showed that MSWI in most of the cities was the source of GHGs, with emissions of 25-207 kg CO{sub 2}-eq t{sup -1} rw. Within all process stages, the emission of fossil CO{sub 2} from the combustion of MSW was the main contributor (111-254 kg CO{sub 2}-eq t{sup -1} rw), while the substitution of electricity reduced the GHG emissions by 150-247 kg CO{sub 2}-eq t{sup -1} rw. By affecting the fossil carbon content and the lower heating value of the waste, the contents of plastic and food waste in the MSW were the critical factors influencing GHG emissions of MSWI. Decreasing food waste content in MSW by half will significantly reduce the GHG emissions from MSWI, and such a reduction will convert MSWI in Urumqi and Tianjin from GHG sources to GHG sinks. Comparison of the GHG emissions in the six Chinese cities with those in European countries revealed that higher energy recovery efficiency in Europe induced much greater reductions in GHG emissions. Recovering the excess heat after generation of electricity would be a good measure to convert MSWI in all the six cities evaluated herein into sinks of GHGs.

  5. Impact of reduced tillage on the greenhouse gas balance - a meta-analysis

    NASA Astrophysics Data System (ADS)

    Don, Axel; Jantz, Marc

    2013-04-01

    Minimum tillage and no-tillage has been acknowledged as human induced measure for climate mitigation due to its potential to sequester additional soil carbon. However, there is increasing evidence that reduced tillage affects the vertical distribution of carbon in the soil profile, but hardy increases soil carbon stocks. Additionally, reduced tillage may increase the N2O emissions that would counterbalance the positive effects of soil carbon sequestration. Here we present a new meta-analysis on the full field scale effect of reduced tillage and no-tillage for the temperate zone including soil organic carbon, N2O and diesel derived fossil fuel emissions for field management. This analysis was performed using strict selection criteria and included data from more than 115 sites on soil carbon stock changes and from more than 30 sites with measured N2O fluxes on paired fields with conventional and reduced tillage. Soil organic carbon stocks did hardly increase (mean ±standard deviation: 2 ±11 Mg C ha-1) under no tillage as compared to moldboard ploughing. At 38% of all sites decreasing soil carbon stocks were detected under no-tillage as compared to conventional tillage. On the other hand, N2O emissions increased by around 40% on no-tillage fields with large deviations between sites. Thus, the total greenhouse gas balance turned out to be more negative for most no-tillage fields as compared to conventional tillage fields. The large observed scatter and deviations between sites and their controlling factors are discussed.

  6. The Impacts of a 2-Degree Rise in Global Temperatures upon Gas-Phase Air Pollutants in Europe

    NASA Astrophysics Data System (ADS)

    Watson, Laura; Josse, Béatrice; Marecal, Virginie; Lacressonnière, Gwendoline; Vautard, Robert; Gauss, Michael; Engardt, Magnuz; Nyiri, Agnes; Siour, Guillaume

    2014-05-01

    The 15th session of the Conference of Parties (COP 15) in 2009 ratified the Copenhagen Accord, which "recognises the scientific view that" global temperature rise should be held below 2 degrees C above pre-industrial levels in order to limit the impacts of climate change. Due to the fact that a 2-degree limit has been frequently referred to by policy makers in the context of the Copenhagen Accord and many other high-level policy statements, it is important that the impacts of this 2-degree increase in temperature are adequately analysed. To this end, the European Union sponsored the project IMPACT2C, which uses a multi-disciplinary international team to assess a wide variety of impacts of a 2-degree rise in global temperatures. For example, this future increase in temperature is expected to have a significant influence upon meteorological conditions such as temperature, precipitation, and wind direction and intensity; which will in turn affect the production, deposition, and distribution of air pollutants. For the first part of the air quality analysis within the IMPACT2C project, the impact of meteorological forcings on gas phase air pollutants over Europe was studied using four offline atmospheric chemistry transport models. Two sets of meteorological forcings were used for each model: reanalysis of past observation data and global climate model output. Anthropogenic emissions of ozone precursors for the year 2005 were used for all simulations in order to isolate the impact of meteorology and assess the robustness of the results across the different models. The differences between the simulations that use reanalysis of past observation data and the simulations that use global climate model output show how global climate models modify climate hindcasts by boundary conditions inputs: information that is necessary in order to interpret simulations of future climate. The baseline results were assessed by comparison with AirBase (Version 7) measurement data, and were

  7. DESIGNING AND CONDUCTING WORKSHOPS: LESSONS FROM A TWO-YEAR PROJECT (ONSHORE IMPACTS OF OUTER CONTINENTAL SHELF OIL AND GAS DEVELOPMENT: A TRAINING PROJECT)

    EPA Science Inventory

    The report describes the process of developing and conducting two series of workshops on 'Onshore Impact of Outer Continental Shelf Oil and Gas Development'. The purpose of this report is to evaluate the workshops from the standpoint of their objectives, content, teaching methods...

  8. Determination of major aroma impact compounds in fermented cucumbers by solid-phase microextraction--gas chromatography--mass spectrometry--olfactometry detection.

    PubMed

    Marsili, R T; Miller, N

    2000-07-01

    Purge-and-trap, solid-phase extraction, and solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) sample preparation techniques for the analysis of odor impact chemicals in fermented cucumber brine are compared. SPME-GC-MS is coupled with detection frequency olfactometry experiments to determine key impact odor compounds in the brine. The most potent odorants that define the typical characteristic brine aroma are trans-4-hexenoic acid and cis-4-hexenoic acid. Confirmation of key impact odorants in brine is confirmed by recombination experiments. PMID:10901416

  9. Evaluating Impacts of CO2 Gas Intrusion Into a Confined Sandstone aquifer: Experimental Results

    DOE PAGESBeta

    Qafoku, Nikolla; Lawter, Amanda R.; Shao, Hongbo; Wang, Guohui; Brown, Christopher F.

    2014-12-31

    Deep subsurface storage and sequestration of CO2 has been identified as a potential mitigation technique for rising atmospheric CO2 concentrations. Sequestered CO2 represents a potential risk to overlying aquifers if the CO2 leaks from the deep storage reservoir. Experimental and modeling work is required to evaluate potential risks to groundwater quality and develop a systematic understanding of how CO2 leakage may cause important changes in aquifer chemistry and mineralogy by promoting dissolution/precipitation, adsorption/desorption, and redox reactions. Sediments from the High Plains aquifer in Kansas, United States, were used in this investigation, which is part of the National Risk Assessment Partnershipmore » Program sponsored by the US Department of Energy. This aquifer was selected to be representative of consolidated sand and gravel/sandstone aquifers overlying potential CO2 sequestration repositories within the continental US. In this paper, we present results from batch experiments conducted at room temperature and atmospheric pressure with four High Plains aquifer sediments. Batch experiments simulate sudden, fast, and short-lived releases of the CO2 gas as would occur in the case of well failure during injection. Time-dependent release of major, minor, and trace elements were determined by analyzing the contacting solutions. Characterization studies demonstrated that the High Plains aquifer sediments were abundant in quartz and feldspars, and contained about 15 to 20 wt% montmorillonite and up to 5 wt% micas. Some of the High Plains aquifer sediments contained no calcite, while others had up to about 7 wt% calcite. The strong acid extraction tests confirmed that in addition to the usual elements present in most soils, rocks, and sediments, the High Plains aquifer sediments had appreciable amounts of As, Cd, Pb, Cu, and occasionally Zn, which potentially may be mobilized from the solid to the aqueous phase during or after exposure to CO2. However

  10. Evaluating Impacts of CO2 Gas Intrusion Into a Confined Sandstone aquifer: Experimental Results

    SciTech Connect

    Qafoku, Nikolla; Lawter, Amanda R.; Shao, Hongbo; Wang, Guohui; Brown, Christopher F.

    2014-12-31

    Deep subsurface storage and sequestration of CO2 has been identified as a potential mitigation technique for rising atmospheric CO2 concentrations. Sequestered CO2 represents a potential risk to overlying aquifers if the CO2 leaks from the deep storage reservoir. Experimental and modeling work is required to evaluate potential risks to groundwater quality and develop a systematic understanding of how CO2 leakage may cause important changes in aquifer chemistry and mineralogy by promoting dissolution/precipitation, adsorption/desorption, and redox reactions. Sediments from the High Plains aquifer in Kansas, United States, were used in this investigation, which is part of the National Risk Assessment Partnership Program sponsored by the US Department of Energy. This aquifer was selected to be representative of consolidated sand and gravel/sandstone aquifers overlying potential CO2 sequestration repositories within the continental US. In this paper, we present results from batch experiments conducted at room temperature and atmospheric pressure with four High Plains aquifer sediments. Batch experiments simulate sudden, fast, and short-lived releases of the CO2 gas as would occur in the case of well failure during injection. Time-dependent release of major, minor, and trace elements were determined by analyzing the contacting solutions. Characterization studies demonstrated that the High Plains aquifer sediments were abundant in quartz and feldspars, and contained about 15 to 20 wt% montmorillonite and up to 5 wt% micas. Some of the High Plains aquifer sediments contained no calcite, while others had up to about 7 wt% calcite. The strong acid extraction tests confirmed that in addition to the usual elements present in most soils, rocks, and sediments, the High Plains aquifer sediments had appreciable amounts of As, Cd, Pb, Cu, and occasionally Zn, which potentially may be mobilized from the solid to the aqueous phase during or after exposure to CO2. However, the

  11. Impact of water table level on annual carbon and greenhouse gas balances of a restored peat extraction area

    NASA Astrophysics Data System (ADS)

    Järveoja, J.; Peichl, M.; Maddison, M.; Soosaar, K.; Vellak, K.; Karofeld, E.; Teemusk, A.; Mander, Ü.

    2015-10-01

    Peatland restoration may provide a potential after-use option to mitigate the negative climate impact of abandoned peat extraction areas; currently, however, knowledge about restoration effects on the annual balances of carbon (C) and greenhouse gas (GHG) exchanges is still limited. The aim of this study was to investigate the impact of contrasting water table levels (WTL) on the annual C and GHG balances of restoration treatments with high (Res-H) and low (Res-L) WTL relative to an unrestored bare peat (BP) site. Measurements of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes were conducted over a full year using the closed chamber method and complemented by measurements of abiotic controls and vegetation cover. Three years following restoration, the difference in the mean WTL resulted in higher bryophyte and lower vascular plant cover in Res-H relative to Res-L. Consequently, greater gross primary production and autotrophic respiration associated with greater vascular plant cover were observed in Res-L compared to Res-H. However, the means of the measured net ecosystem CO2 exchanges (NEE) were not significantly different between Res-H and Res-L. Similarly, no significant differences were observed in the respective means of CH4 and N2O exchanges in Res-H and Res-L, respectively. In comparison to the two restored sites, greater net CO2, similar CH4 and greater N2O emissions occurred in BP. On the annual scale, Res-H, Res-L and BP were C sources of 111, 103 and 268 g C m-2 yr-1 and had positive GHG balances of 4.1, 3.8 and 10.2 t CO2 eq ha-1 yr-1, respectively. Thus, the different WTLs had a limited impact on the C and GHG balances in the two restored treatments three years following restoration. However, the C and GHG balances in Res-H and Res-L were considerably lower than in BP owing to the large reduction in CO2 emissions. This study therefore suggests that restoration may serve as an effective method to mitigate the negative climate impacts

  12. Impact of water table level on annual carbon and greenhouse gas balances of a restored peat extraction area

    NASA Astrophysics Data System (ADS)

    Järveoja, Järvi; Peichl, Matthias; Maddison, Martin; Soosaar, Kaido; Vellak, Kai; Karofeld, Edgar; Teemusk, Alar; Mander, Ülo

    2016-05-01

    Peatland restoration may provide a potential after-use option to mitigate the negative climate impact of abandoned peat extraction areas; currently, however, knowledge about restoration effects on the annual balances of carbon (C) and greenhouse gas (GHG) exchanges is still limited. The aim of this study was to investigate the impact of contrasting mean water table levels (WTLs) on the annual C and GHG balances of restoration treatments with high (ResH) and low (ResL) WTL relative to an unrestored bare peat (BP) site. Measurements of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes were conducted over a full year using the closed chamber method and complemented by measurements of abiotic controls and vegetation cover. Three years following restoration, the difference in the mean WTL resulted in higher bryophyte and lower vascular plant cover in ResH relative to ResL. Consequently, greater gross primary production and autotrophic respiration associated with greater vascular plant cover were observed in ResL compared to ResH. However, the means of the measured net ecosystem CO2 exchanges (NEE) were not significantly different between ResH and ResL. Similarly, no significant differences were observed in the respective means of CH4 and N2O exchanges. In comparison to the two restored sites, greater net CO2, similar CH4 and greater N2O emissions occurred in BP. On the annual scale, ResH, ResL and BP were C sources of 111, 103 and 268 g C m-2 yr-1 and had positive GHG balances of 4.1, 3.8 and 10.2 t CO2 eq ha-1 yr-1, respectively. Thus, the different WTLs had a limited impact on the C and GHG balances in the two restored treatments 3 years following restoration. However, the C and GHG balances in ResH and ResL were considerably lower than in BP due to the large reduction in CO2 emissions. This study therefore suggests that restoration may serve as an effective method to mitigate the negative climate impacts of abandoned peat extraction areas.

  13. The impact of the weather conditions on the cooling performance of the heat pump driven by an internal natural gas combustion engine

    NASA Astrophysics Data System (ADS)

    Janovcová, Martina; Jandačka, Jozef; Malcho, Milan

    2015-05-01

    Market with sources of heat and cold offers unlimited choice of different power these devices, design technology, efficiency and price categories. New progressive technologies are constantly discovering, about which is still little information, which include heat pumps powered by a combustion engine running on natural gas. A few pieces of these installations are in Slovakia, but no studies about their work and effectiveness under real conditions. This article deals with experimental measurements of gas heat pump efficiency in cooling mode. Since the gas heat pump works only in system air - water, air is the primary low - energy source, it is necessary to monitor the impact of the climate conditions for the gas heat pump performance.

  14. Impact of the etching gas on vertically oriented single wall and few walled carbon nanotubes by plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Gohier, A.; Minea, T. M.; Djouadi, M. A.; Granier, A.

    2007-03-01

    Vertically oriented single wall nanotubes (SWNTs) and few walled nanotubes (FWNTs) have been grown by electronic cyclotron resonance plasma enhanced chemical vapor deposition (PECVD) on silica flat substrates. The impact of the plasma parameters on SWNT and FWNT growth has been investigated using two different etching gas mixtures, namely, C2H2/NH3 and C2H2/H2 with various ratios and applied bias voltages. Kinetic studies are also proposed in order to describe the FWNT growth mechanism by plasma techniques. A key role played by the reactive gas (NH3 and H2) is observed in the PECVD process, contrary to multiwalled nanotube growth. It is demonstrated that the balance between FWNT growth versus FWNT etching can be widely modulated by varying the gas mixture and bias voltage. It is shown that the use of hydrogen for hydrocarbon gas dilution restricts the destruction of SWNT and FWNT by the plasma species (ions and radicals).

  15. Assessing impacts of alternative fertilizer management practices on both nitrogen loading and greenhouse gas emissions in rice cultivation

    NASA Astrophysics Data System (ADS)

    Zhao, Zheng; Yue, Yubo; Sha, Zhimin; Li, Changsheng; Deng, Jia; Zhang, Hanlin; Gao, Maofang; Cao, Linkui

    2015-10-01

    Nitrogen (N) losses and greenhouse gas (GHG) emissions from paddy rice fields contaminate water bodies and atmospheric environment. A 2-year (2012-2013) field experiment was conducted at a typical paddy rice field in a rural suburb of Shanghai, China. N losses and GHG emissions from the paddy field with alternative fertilizer management practices were simultaneously measured. Four treatments were tested in the experiment: applications of only chemical synthetic fertilizer urea (CT), only organic manure (OT), a combination of the two types of fertilizers (MT) and a control (CK). Results from the field study indicated that CT produced the highest seasonal N loading rate (18.79 kg N/ha) and N2O emissions (1.81 kg N2O/ha) but with the lowest seasonal CH4 emissions (69.09 kg CH4/ha). With organic manure applied, MT and OT respectively reduced N loading by 21.86% and 30.41%, reduced N2O emissions by 28.34% and 69.41%, but increased CH4 emissions by 137% and 310% in comparison with CT. However, the net impact of CH4 and N2O emissions on global warming was enhanced when organic manure was applied. In addition, CT and MT produced the optimal rice yield during the experimental period, while OT treatment led to a yield reduction by 9.29% compared with CT. In conclusion, the impacts of alternative fertilizer management practices on ecosystem services ought to be assessed specifically due to the great variations across rice yields, N loss and GHG emissions.

  16. Impacts of Enhanced-Efficiency Nitrogen Fertilizers on Greenhouse Gas Emissions in a Coastal Plain Soil under Cotton.

    PubMed

    Watts, Dexter B; Runion, G Brett; Smith Nannenga, Katy W; Torbert, H Allen

    2015-11-01

    Enhanced-efficiency N fertilizers (EENFs) have the potential to increase crop yield while decreasing soil N loss. However, the effect of EENFs on greenhouse gas (GHG) emissions from different agricultural systems is not well understood. Thus, studies from a variety of locations and cropping systems are needed to evaluate their impact. An experiment was initiated on a Coastal Plain soil under cotton ( L.) production for comparing EENFs to traditional sources. Nitrogen sources included urea, ammonia sulfate (AS), urea-ammonia sulfate (UAS), controlled-release, polymer-coated urea (Environmental Smart Nitrogen [ESN]), stabilized granular urea (SuperU), poultry litter (PL), poultry litter plus AgrotainPlus (PLA), and an unfertilized control. Carbon dioxide (CO), nitrous oxide (NO), and methane (CH) fluxes were monitored regularly after fertilization through harvest from 2009 to 2011 using a closed-chamber method. Poultry litter and PLA had higher CO flux than other N treatments, while ESN and SU were generally lowest following fertilization. Nitrous oxide fluxes were highly variable and rarely affected by N treatments; PL and PLA were higher but only during the few samplings in 2010 and 2011. Methane fluxes were higher in 2009 (wet year) than 2010 or 2011, and N treatments had minimal impact. Global warming potential (GWP), calculated from cumulative GHG fluxes, was highest with PL and PLA and lowest for control, UAS, ESN, and SU. Results suggest that PL application to cotton increases GHG flux, but GHG flux reductions from EENFs were infrequently different from standard inorganic fertilizers, suggesting their higher cost may render them presently impractical. PMID:26641321

  17. The Impact of Region, Nitrogen Use Efficiency, and Grower Incentives on Greenhouse Gas Mitigation in Canola (Brassica napus) Production

    NASA Astrophysics Data System (ADS)

    Hammac, W. A.; Pan, W.; Koenig, R. T.; McCracken, V.

    2012-12-01

    The Environmental Protection Agency (EPA) has mandated through the second renewable fuel standard (RFS2) that biodiesel meet a minimum threshold requirement (50% reduction) for greenhouse gas (GHG) emission reduction compared to fossil diesel. This designation is determined by life cycle assessment (LCA) and carries with it potential for monetary incentives for biodiesel feedstock growers (Biomass Crop Assistance Program) and biodiesel processors (Renewable Identification Numbers). A national LCA was carried out for canola (Brassica napus) biodiesel feedstock by the EPA and it did meet the minimum threshold requirement. However, EPA's national LCA does not provide insight into regional variation in GHG mitigation. The authors propose for full GHG reduction potential of biofuels to be realized, LCA results must have regional specificity and should inform incentives for growers and processors on a regional basis. The objectives of this work were to determine (1) variation in biofuel feedstock production related GHG emissions between three agroecological zones (AEZs) in eastern Washington State (2) the impact of nitrogen use efficiency (NUE) on GHG mitigation potential for each AEZ and (3) the impact of incentives on adoption of oilseed production. Results from objective (1) revealed there is wide variability in range for GHG estimates both across and within AEZs based on variation in farming practices and environment. It is expected that results for objective (2) will show further GHG mitigation potential due to minimizing N use and therefore fertilizer transport and soil related GHG emission while potentially increasing biodiesel production per hectare. Regional based incentives may allow more timely achievement of goals for bio-based fuels production. Additionally, incentives may further increase GHG offsetting by promoting nitrogen conserving best management practices implementation. This research highlights the need for regional assessment/incentive based

  18. Impact of supplemental firing of tire-derived fuel (TDF) on mercury species and mercury capture with the advanced hybrid filter in a western subbituminous coal flue gas

    SciTech Connect

    Ye Zhuang; Stanley J. Miller

    2006-05-15

    Pilot-scale experimental studies were carried out to evaluate the impacts of cofiring tire-derived fuel and a western subbituminous coal on mercury species in flue gas. Mercury samples were collected at the inlet and outlet of the Advanced Hybrid filter to determine mercury concentrations in the flue gas with and without TDF cofiring, respectively. Cofiring of TDF with a subbituminous coal had a significant effect on mercury speciation in the flue gas. With 100% coal firing, there was only 16.8% oxidized mercury in the flue gas compared to 47.7% when 5% TDF (mass basis) was fired and 84.8% when 10% TDF was cofired. The significantly enhanced mercury oxidation may be the result of additional homogeneous gas reactions between Hg{sup 0} and the reactive chlorine generated in the TDF-cofiring flue gas and the in situ improved reactivity of unburned carbon in ash by the reactive chlorine species. Although the cofiring of TDF demonstrated limited improvement on mercury-emission control with the Advanced Hybrid filter, it proved to be a very cost-effective mercury control approach for power plants equipped with wet or dry flue gas desulfurization (FGD) systems because of the enhanced mercury oxidation. 15 refs., 4 figs., 4 tabs.

  19. Sulfur and Iron Speciation in Gas-rich Impact-melt Glasses from Basaltic Shergottites Determined by Microxanes

    NASA Technical Reports Server (NTRS)

    Sutton, S. R.; Rao, M. N.; Nyquist, L. E.

    2008-01-01

    Sulfur is abundantly present as sulfate near Martian surface based on chemical and mineralogical investigations on soils and rocks in Viking, Pathfinder and MER missions. Jarosite is identified by Mossbauer studies on rocks at Meridian and Gusev, whereas MgSO4 is deduced from MgO - SO3 correlations in Pathfinder MER and Viking soils. Other sulfate minerals such as gypsum and alunogen/ S-rich aluminosilicates and halides are detected only in martian meteorites such as shergottites and nakhlites using SEM/FE-SEM and EMPA techniques. Because sulfur has the capacity to occur in multiple valence states, determination of sulfur speciation (sulfide/ sulfate) in secondary mineral assemblages in soils and rocks near Mars surface may help us understand whether the fluid-rock interactions occurred under oxidizing or reducing conditions. To understand the implications of these observations for the formation of the Gas-rich Impact-melt (GRIM) glasses, we determined the oxidation state of Fe in the GRIM glasses using Fe K micro-XANES techniques.

  20. Impact of the renewable oxygenate standard for reformulated gasoline on ethanol demand, energy use, and greenhouse gas emissions

    SciTech Connect

    Stork, K.C.; Singh, M.K.

    1995-04-01

    To assure a place for renewable oxygenates in the national reformulated gasoline (RFG) program, the US Environmental Protection Agency has promulgated the renewable oxygenate standard (ROS) for RFG. It is assumed that ethanol derived from corn will be the only broadly available renewable oxygenate during Phase I of the RFG program. This report analyzes the impact that the ROS could have on the supply of ethanol, its transported volume, and its displacement from existing markets. It also considers the energy and crude oil consumption and greenhouse gas (GHG) emissions that could result from the production and use of various RFGs that could meet the ROS requirements. The report concludes that on the basis of current and projected near-term ethanol capacity, if ethanol is the only available renewable oxygenate used to meet the requirements of the ROS, diversion of ethanol from existing use as a fuel is likely to be necessary. Year-round use of ethanol and ETBE would eliminate the need for diversion by reducing winter demand for ethanol. On an RFG-program-wide basis, using ethanol and ETBE to satisfy the ROS can be expected to slightly reduce fossil energy use, increase crude oil use, and have essentially no effect on GHG emissions or total energy use relative to using RFG oxygenated only with MTBE.

  1. Direct green waste land application: How to reduce its impacts on greenhouse gas and volatile organic compound emissions?

    PubMed

    Zhu-Barker, Xia; Burger, Martin; Horwath, William R; Green, Peter G

    2016-06-01

    Direct land application as an alternative to green waste (GW) disposal in landfills or composting requires an understanding of its impacts on greenhouse gas (GHG) and volatile organic compound (VOC) emissions. We investigated the effects of two approaches of GW direct land application, surface application and soil incorporation, on carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), and VOC emissions for a 12month period. Five treatments were applied in fall 2013 on fallow land under a Mediterranean climate in California: 30cm height GW on surface; 15cm height GW on surface; 15cm height GW tilled into soil; control+till; control+no till. In addition, a laboratory experiment was conducted to develop a mechanistic understanding of the influence of GW application on soil O2 consumption and GHG emission. The annual cumulative N2O, CO2 and VOC emissions ranged from 1.6 to 5.5kgN2O-Nha(-1), 5.3 to 40.6MgCO2-Cha(-1) and 0.6 to 9.9kgVOCha(-1), respectively, and were greatly reduced by GW soil incorporation compared to surface application. Application of GW quickly consumed soil O2 within one day in the lab incubation. These results indicate that to reduce GHG and VOC emissions of GW direct land application, GW incorporation into soil is recommended. PMID:27033991

  2. Fisheries impacts of underwater explosives used to salvage oil and gas platforms in the Gulf of Mexico

    SciTech Connect

    Gitschlag, G.R.

    1997-05-01

    There are more than 4,000 oil and gas structures present in the U.S. Gulf of Mexico. Approximately 100 structure removals occur each year and 66% of these are removed with explosives. From 1993-1995 an intensive study was conducted on the fish kill resulting from the explosive removal of 6 platforms off the Louisiana coast in water depths from 14-28 m (45-92 ft). After explosives were detonated, all floating fish and a sample of the dead fish which sank to the sea floor were collected. Estimated fish mortality ranged from approximately 2,000-5,000 with a mean of 3,000 and standard deviation of 1,045. The four most abundant species impacted by underwater explosives included spadefish, blue runner, red snapper, and sheepshead. One of these species, red snapper, is important both commercially and recreationally. Estimated mortality of red snapper ranged from 0-1200 with an average per platform of 500. A large standard deviation of 414 indicated high variability in red snapper mortality between platforms. Further study is planned to increase sample size, reduce variance, and address deeper water platform removals where red snapper abundance is expected to increase.

  3. The impact of using biodiesel/marine gas oil blends on exhaust emissions from a stationary diesel engine.

    PubMed

    Karavalakis, G; Tzirakis, E; Mattheou, L; Stournas, S; Zannikos, F; Karonis, D

    2008-12-01

    The purpose of this work was to investigate the impact of marine gas oil (MGO)/biodiesel blends on the exhaust emissions and fuel consumption in a single cylinder, stationary, diesel engine. Three different origins of biodiesel were used as the blending feedstock with the reference MGO, at proportions of 5 and 10% by volume. Methyl esters were examined according to the automotive FAME standard EN 14214. The baseline MGO and biodiesel blends were examined according to ISO 8217:2005 specifications for the DMA category. Independently of the biodiesel used, a decrease of PM, HC, CO and CO(2) emissions was observed. Emissions of NO(x) were also lower with respect to MGO. This reduction in NO(x) may be attributed to some physicochemical properties of the fuels applied, such as the higher cetane number and the lower volatility of methyl esters. Reductions in PM for biodiesel blends were lower in the exhaust than those of the reference fuel which was attributed to the oxygen content and the near absence of sulphur and aromatics compounds in biodiesel. However, a slight increase in fuel consumption was observed for the biodiesel blends that may be tolerated due to the exhaust emissions benefits. Brake thermal efficiency was also determined. Unregulated emissions were characterized by determining the soluble organic fraction content of the particulate matter. PMID:18988104

  4. Impacts of ocean acidification on respiratory gas exchange and acid-base balance in a marine teleost, Opsanus beta.

    PubMed

    Esbaugh, Andrew J; Heuer, Rachael; Grosell, Martin

    2012-10-01

    The oceanic carbonate system is changing rapidly due to rising atmospheric CO(2), with current levels expected to rise to between 750 and 1,000 μatm by 2100, and over 1,900 μatm by year 2300. The effects of elevated CO(2) on marine calcifying organisms have been extensively studied; however, effects of imminent CO(2) levels on teleost acid-base and respiratory physiology have yet to be examined. Examination of these physiological processes, using a paired experimental design, showed that 24 h exposure to 1,000 and 1,900 μatm CO(2) resulted in a characteristic compensated respiratory acidosis response in the gulf toadfish (Opsanus beta). Time course experiments showed the onset of acidosis occurred after 15 min of exposure to 1,900 and 1,000 μatm CO(2), with full compensation by 2 and 4 h, respectively. 1,900-μatm exposure also resulted in significantly increased intracellular white muscle pH after 24 h. No effect of 1,900 μatm was observed on branchial acid flux; however, exposure to hypercapnia and HCO(3)(-) free seawater compromised compensation. This suggests branchial HCO(3)(-) uptake rather than acid extrusion is part of the compensatory response to low-level hypercapnia. Exposure to 1,900 μatm resulted in downregulation in branchial carbonic anhydrase and slc4a2 expression, as well as decreased Na(+)/K(+) ATPase activity after 24 h of exposure. Infusion of bovine carbonic anhydrase had no effect on blood acid-base status during 1,900 μatm exposures, but eliminated the respiratory impacts of 1,000 μatm CO(2). The results of the current study clearly show that predicted near-future CO(2) levels impact respiratory gas transport and acid-base balance. While the full physiological impacts of increased blood HCO(3)(-) are not known, it seems likely that chronically elevated blood HCO(3)(-) levels could compromise several physiological systems and furthermore may explain recent reports of increased otolith growth during exposure to elevated CO(2). PMID

  5. Oil and gas impacts on air quality in federal lands in the Bakken region: an overview of the Bakken Air Quality Study and first results

    NASA Astrophysics Data System (ADS)

    Prenni, A. J.; Day, D. E.; Evanoski-Cole, A. R.; Sive, B. C.; Hecobian, A.; Zhou, Y.; Gebhart, K. A.; Hand, J. L.; Sullivan, A. P.; Li, Y.; Schurman, M. I.; Desyaterik, Y.; Malm, W. C.; Collett, J. L., Jr.; Schichtel, B. A.

    2016-02-01

    The Bakken formation contains billions of barrels of oil and gas trapped in rock and shale. Horizontal drilling and hydraulic fracturing methods have allowed for extraction of these resources, leading to exponential growth of oil production in the region over the past decade. Along with this development has come an increase in associated emissions to the atmosphere. Concern about potential impacts of these emissions on federal lands in the region prompted the National Park Service to sponsor the Bakken Air Quality Study over two winters in 2013-2014. Here we provide an overview of the study and present some initial results aimed at better understanding the impact of local oil and gas emissions on regional air quality. Data from the study, along with long-term monitoring data, suggest that while power plants are still an important emissions source in the region, emissions from oil and gas activities are impacting ambient concentrations of nitrogen oxides and black carbon and may dominate recent observed trends in pollutant concentrations at some of the study sites. Measurements of volatile organic compounds also definitively show that oil and gas emissions were present in almost every air mass sampled over a period of more than 4 months.

  6. Oil and gas impacts on air quality in federal lands in the Bakken region: an overview of the Bakken Air Quality Study and first results

    NASA Astrophysics Data System (ADS)

    Prenni, A. J.; Day, D. E.; Evanoski-Cole, A. R.; Sive, B. C.; Hecobian, A.; Zhou, Y.; Gebhart, K. A.; Hand, J. L.; Sullivan, A. P.; Li, Y.; Schurman, M. I.; Desyaterik, Y.; Malm, W. C.; Schichtel, B. A.; Collett, J. L., Jr.

    2015-10-01

    The Bakken formation contains billions of barrels of oil and gas trapped in rock and shale. Horizontal drilling and hydraulic fracturing methods have allowed for extraction of these resources, leading to exponential growth of oil production in the region over the past decade. Along with this development has come an increase in associated emissions to the atmosphere. Concern about potential impacts of these emissions on federal lands in the region prompted the National Park Service to sponsor the Bakken Air Quality Study over two winters in 2013-2014. Here we provide an overview of the study and present some initial results aimed at better understanding the impact of local oil and gas emissions on regional air quality. Data from the study, along with long term monitoring data, suggest that while power plants are still an important emissions source in the region, emissions from oil and gas activities are impacting ambient concentrations of nitrogen oxides and black carbon and may dominate recent observed trends in pollutant concentrations at some of the study sites. Measurements of volatile organic compounds also definitively show that oil and gas emissions were present in almost every air mass sampled over a period of more than four months.

  7. Impacts of Sedimentation from Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds of the Allegheny National Forest of Northwestern Pennsylvania

    SciTech Connect

    Fritz, K.; Harris, S.; Edenborn, H.M.; Sams, J.

    2011-01-01

    Fritz, Kelley'*, Steven Harris', Harry Edenborn2, and James Sams2. 'Clarion University of Pennsylvania, Clarion, PA 16214, 2National Energy Technology Laboratory, U.S. Dept. Energy, Pittsburgh, PA 15236. Impacts a/Sedimentation/rom Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds a/the Allegheny National Forest a/Northwestern Pennsylvania - The Allegheny National Forest (ANF), located in northwestern Pennsy Ivania, is a multiuse forest combining commercial development with recreational and conservation activities. As such, portions of the ANF have been heavily logged and are now the subject of widespread oil and gas development. This rapid increase in oil and gas development has led to concerns about sediment runoff from the dirt and gravel roads associated with development and the potential impact on the aquatic biota of the receiving streams. We examined and compared the benthic macroinvertebrate communities in two adjacent watersheds of similar size and topography in the ANF; the Hedgehog Run watershed has no oil and gas development, while the adjacent Grunder Run watershed has extensive oil and gas development. In Hedgehog and Grunder Run, we collected monthly kicknet samples from riffles and glides at two sites from April to October 2010. At the same intervals, we measured standard water quality parameters, including conductivity and turbidity. Preliminary results have indicated much higher turbidity in Grunder Run, but little difference in the diversity and abundance of benthic macro invertebrates inhabiting the two streams.

  8. Marcellus and mercury: Assessing potential impacts of unconventional natural gas extraction on aquatic ecosystems in northwestern Pennsylvania.

    PubMed

    Grant, Christopher J; Weimer, Alexander B; Marks, Nicole K; Perow, Elliott S; Oster, Jacob M; Brubaker, Kristen M; Trexler, Ryan V; Solomon, Caroline M; Lamendella, Regina

    2015-01-01

    Mercury (Hg) is a persistent element in the environment that has the ability to bioaccumulate and biomagnify up the food chain with potentially harmful effects on ecosystems and human health. Twenty-four streams remotely located in forested watersheds in northwestern PA containing naturally reproducing Salvelinus fontinalis (brook trout), were targeted to gain a better understanding of how Marcellus shale natural gas exploration may be impacting water quality, aquatic biodiversity, and Hg bioaccumulation in aquatic ecosystems. During the summer of 2012, stream water, stream bed sediments, aquatic mosses, macroinvertebrates, crayfish, brook trout, and microbial samples were collected. All streams either had experienced hydraulic fracturing (fracked, n = 14) or not yet experienced hydraulic fracturing (non-fracked, n = 10) within their watersheds at the time of sampling. Analysis of watershed characteristics (GIS) for fracked vs non-fracked sites showed no significant differences (P > 0.05), justifying comparisons between groups. Results showed significantly higher dissolved total mercury (FTHg) in stream water (P = 0.007), lower pH (P = 0.033), and higher dissolved organic matter (P = 0.001) at fracked sites. Total mercury (THg) concentrations in crayfish (P = 0.01), macroinvertebrates (P = 0.089), and predatory macroinvertebrates (P = 0.039) were observed to be higher for fracked sites. A number of positive correlations between amount of well pads within a watershed and THg in crayfish (r = 0.76, P < 0.001), THg in predatory macroinvertebrates (r = 0.71, P < 0.001), and THg in brook trout (r = 0.52, P < 0.01) were observed. Stream-water microbial communities within the Deltaproteobacteria also shared a positive correlation with FTHg and to the number of well pads, while stream pH (r = -0.71, P < 0.001), fish biodiversity (r = -0.60, P = 0.02), and macroinvertebrate taxa richness (r = -0.60, P = 0.01) were negatively correlated with the number of well pads within a

  9. Results of the California Healthy Homes Indoor Air Quality Study of 2011-2013: impact of natural gas appliances on air pollutant concentrations.

    PubMed

    Mullen, N A; Li, J; Russell, M L; Spears, M; Less, B D; Singer, B C

    2016-04-01

    This study was conducted to assess the current impact of natural gas appliances on air quality in California homes. Data were collected via telephone interviews and measurements inside and outside of 352 homes. Passive samplers measured time-resolved CO and time-integrated NOX , NO2 , formaldehyde, and acetaldehyde over ~6-day periods in November 2011 - April 2012 and October 2012 - March 2013. The fraction of indoor NOX and NO2 attributable to indoor sources was estimated. NOX , NO2 , and highest 1-h CO were higher in homes that cooked with gas and increased with amount of gas cooking. NOX and NO2 were higher in homes with cooktop pilot burners, relative to gas cooking without pilots. Homes with a pilot burner on a floor or wall furnace had higher kitchen and bedroom NOX and NO2 compared to homes without a furnace pilot. When scaled to account for varying home size and mixing volume, indoor-attributed bedroom and kitchen NOX and kitchen NO2 were not higher in homes with wall or floor furnace pilot burners, although bedroom NO2 was higher. In homes that cooked 4 h or more with gas, self-reported use of kitchen exhaust was associated with lower NOX , NO2 , and highest 1-h CO. Gas appliances were not associated with higher concentrations of formaldehyde or acetaldehyde. PMID:25647016

  10. Results of the California Healthy Homes Indoor Air Quality Study of 2011-2013: Impact of natural gas appliances on air pollutant concentrations

    DOE PAGESBeta

    Mullen, Nasim A.; Li, Jina; Russell, Marion L.; Spears, Michael; Less, Brennan D.; Singer, Brett C.

    2015-03-17

    This study was conducted to assess the current impact of natural gas appliances on air quality in California homes. Data were collected via telephone interviews and measurements inside and outside of 352 homes. Passive samplers measured time-resolved CO and time-integrated NOX, NO2, formaldehyde, and acetaldehyde over ~6d periods in November 2011 - April 2012 and October 2012 - March 2013. The fraction of indoor NOX and NO2 attributable to indoor sources was estimated. NOX, NO2 and highest 1-h CO were higher in homes that cooked with gas and increased with amount of gas cooking. NOX and NO2 were higher inmore » homes with cooktop pilot burners, relative to gas cooking without pilots. Homes with a pilot burner on a floor or wall furnace had higher kitchen and bedroom NOX and NO2 compared to homes without a furnace pilot. When scaled to account for varying home size and mixing volume, indoor-attributed bedroom and kitchen NOX and kitchen NO2 were not higher in homes with wall or floor furnace pilot burners, though bedroom NO2 was higher. In homes that cooked 4 h or more with gas, self-reported use of kitchen exhaust was associated with lower NOX, NO2 and highest 1-h CO. Gas appliances were not associated with higher concentrations of formaldehyde or acetaldehyde.« less

  11. Anthropogenic Sulfur Perturbations on Biogenic Oxidation: SO2 Additions Impact Gas-Phase OH Oxidation Products of α- and β-Pinene.

    PubMed

    Friedman, Beth; Brophy, Patrick; Brune, William H; Farmer, Delphine K

    2016-02-01

    In order to probe how anthropogenic pollutants can impact the atmospheric oxidation of biogenic emissions, we investigated how sulfur dioxide (SO2) perturbations impact the oxidation of two monoterpenes, α-and β-pinene. We used chemical ionization mass spectrometry to examine changes in both individual molecules and gas-phase bulk properties of oxidation products as a function of SO2 addition. SO2 perturbations impacted the oxidation systems of α-and β-pinene, leading to an ensemble of products with a lesser degree of oxygenation than unperturbed systems. These changes may be due to shifts in the OH:HO2 ratio from SO2 oxidation and/or to SO3 reacting directly with organic molecules. Van Krevelen diagrams suggest a shift from gas-phase functionalization by alcohol/peroxide groups to functionalization by carboxylic acid or carbonyl groups, consistent with a decreased OH:HO2 ratio. Increasing relative humidity dampens the impact of the perturbation. This decrease in oxygenation may impact secondary organic aerosol formation in regions dominated by biogenic emissions with nearby SO2 sources. We observed sulfur-containing organic compounds following SO2 perturbations of monoterpene oxidation; whether these are the result of photochemistry or an instrumental artifact from ion-molecule clustering remains uncertain. However, our results demonstrate that the two monoterpene isomers produce unique suites of oxidation products. PMID:26735899

  12. Long-term impacts of manure amendments on carbon and greenhouse gas dynamics of rangelands.

    PubMed

    Owen, Justine J; Parton, William J; Silver, Whendee L

    2015-12-01

    Livestock manure is applied to rangelands as an organic fertilizer to stimulate forage production, but the long-term impacts of this practice on soil carbon (C) and greenhouse gas (GHG) dynamics are poorly known. We collected soil samples from manured and nonmanured fields on commercial dairies and found that manure amendments increased soil C stocks by 19.0 ± 7.3 Mg C ha(-1) and N stocks by 1.94 ± 0.63 Mg N ha(-1) compared to nonmanured fields (0-20 cm depth). Long-term historical (1700-present) and future (present-2100) impacts of management on soil C and N dynamics, net primary productivity (NPP), and GHG emissions were modeled with DayCent. Modeled total soil C and N stocks increased with the onset of dairying. Nitrous oxide (N2 O) emissions also increased by ~2 kg N2 O-N ha(-1)  yr(-1) . These emissions were proportional to total N additions and offset 75-100% of soil C sequestration. All fields were small net methane (CH4 ) sinks, averaging -4.7 ± 1.2 kg CH4 -C ha(-1)  yr(-1) . Overall, manured fields were net GHG sinks between 1954 and 2011 (-0.74 ± 0.73 Mg CO2 e ha(-1)  yr(-1) , CO2 e are carbon dioxide equivalents), whereas nonmanured fields varied around zero. Future soil C pools stabilized 40-60 years faster in manured fields than nonmanured fields, at which point manured fields were significantly larger sources than nonmanured fields (1.45 ± 0.52 Mg CO2 e ha(-1)  yr(-1) and 0.51 ± 0.60 Mg CO2 e ha(-1)  yr(-1) , respectively). Modeling also revealed a large background loss of soil C from the passive soil pool associated with the shift from perennial to annual grasses, equivalent to 29.4 ± 1.47 Tg CO2 e in California between 1820 and 2011. Manure applications increased NPP and soil C storage, but plant community changes and GHG emissions decreased, and eventually eliminated, the net climate benefit of this practice. PMID:26183573

  13. Global Impacts of Gas-Phase Chemistry-Aerosol Interactions on Direct Radiative Forcing by Anthropogenic Aerosols and Ozone

    NASA Technical Reports Server (NTRS)

    Liao, Hong; Seinfeld, John H.

    2005-01-01

    We present here a first global modeling study on the influence of gas-phase chemistry/aerosol interactions on estimates of anthropogenic forcing by tropospheric O3 and aerosols. Concentrations of gas-phase species and sulfate, nitrate, ammonium, black carbon, primary organic carbon, secondary organic carbon, sea salt, and mineral dust aerosols in the preindustrial, present-day, and year 2100 (IPCC SRES A2) atmospheres are simulated online in the Goddard Institute for Space Studies general circulation model II' (GISS GCM II'). With fully coupled chemistry and aerosols, the preindustrial, presentday, and year 2100 global burdens of tropospheric ozone are predicted to be 190, 319, and 519 Tg, respectively. The burdens of sulfate, nitrate, black carbon, and organic carbon are predicted respectively to be 0.32. 0.18, 0.01, 0.33 Tg in preindustrial time, 1.40, 0.48, 0.23, 1.60 Tg in presentday, and 1.37, 1.97, 0.54, 3.31 Tg in year 2100. Anthropogenic O3 is predicted to have a globally and annually averaged present-day forcing of +0.22 W m(sup -2) and year 2100 forcing of +0.57 W m(sup -2) at the top of the atmosphere (TOA). Net anthropogenic TOA forcing by internally mixed sulfate, nitrate, organic carbon, and black carbon aerosols is estimated to be virtually zero in the present-day and +0.34 W m(sup -2) in year 2100, whereas it is predicted to be -0.39 W m(sup -2) in present-day and -0.61 W m(sup -2) in year 2100 if the aerosols are externally mixed. Heterogeneous reactions are shown to be important in affecting anthropogenic forcing. When reactions of N2O5, NO3, NO2, and HO2 on aerosols are accounted for, TOA anthropogenic O3 forcing is less by 20-45% in present-day and by 20-32% in year 2100 at mid to high latitudes in the Northern Hemisphere, as compared with values predicted in the absence of heterogeneous gas aerosol reactions. Mineral dust uptake of HNO3 and O3 is shown to have practically no influence on anthropogenic O3 forcing. Heterogeneous reactions of N2Os

  14. Impact of surrounding environment evolution on long-term gas flux measurements in a temperate mixed forest

    NASA Astrophysics Data System (ADS)

    Hurdebise, Quentin; Rixen, Toma; De Ligne, Anne; Vincke, Caroline; Heinesch, Bernard; Aubinet, Marc

    2016-04-01

    With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will become more and more numerous. However, long-term analyses of such exchanges require a good understanding of measurement conditions during the investigated period. Independently of climate drivers, measurements may indeed be influenced by measurement conditions themselves subjected to long-term variability due to vegetation growth or set-up changes. The present research refers to the Vielsalm Terrestrial Observatory (VTO) where fluxes of momentum, carbon dioxide, latent and sensible heat have been continuously measured by eddy covariance during twenty years. VTO is an ICOS site installed in a mixed forest (beech, silver fir, Douglas fir, Norway spruce) in the Belgian Ardennes. A multidisciplinary approach was developed in order to investigate the spatial and temporal evolution of several site characteristics: -displacement height (d) and relative measurement height (z-d) were determined using a spectral approach that compared observed and theoretical cospectra; -turbulence statistics were analyzed in the context of Monin-Obukhov similarity theory; -tree height during the measurement period was obtained by combining tree height inventories, a LIDAR survey and tree growth models; -measurement footprint was determined by using a footprint model. A good agreement was found between the three first approaches. Results show notably that z-d was subjected to both temporal and spatial evolution. Temporal evolution resulted from continuous tree growth as well as from a tower raise, achieved in 2009. Spatial evolution, due to canopy heterogeneity, was also observed. The impacts of these changes on measurements are investigated. In particular, it was shown that they affect measurement footprint, flux spectral corrections and flux quality. All these effects must be taken into

  15. Availability of polycyclic aromatic hydrocarbons from lampblack-impacted soils at former oil-gas plant sites in California, USA.

    PubMed

    Hong, Lei; Luthy, Richard G

    2007-03-01

    Lampblack-impacted soils at former oil-gas plant sites in California, USA, were characterized to assess the sorption of polycyclic aromatic hydrocarbons (PAHs) and the concentration-dependent effects of a residual oil tar phase on sorption mechanism and availability of PAHs. Nuclear magnetic resonance spectroscopy demonstrated similar aromaticity for both lampblack carbon and the oil tar phase, with pronounced resonance signals in the range of 100 to 150 ppm. Scanning-electron microscopic images revealed a physically distinct oil tar phase, especially at high concentrations in lampblack, which resulted in an organic-like film structure when lampblack particles became saturated with the oil tar. Sorption experiments were conducted on a series of laboratory-prepared lampblack samples to systematically evaluate influences of an oil tar phase on PAH sorption to lampblack. Results indicate that the sorption of PAHs to lampblack exhibits a competition among sorption phases at low oil tar contents when micro- and mesopores are accessible. When the oil tar content increases to more than 5 to 10% by weight, this tar phase fills small pores, reduces surface area, and dominates PAH sorption on lampblack surface. A new PAH partitioning model, Kd = KLB-C(1 - ftar)alpha + ftarKtar (alpha = empirical exponent), incorporates these effects in which the control of PAH partitioning transits from being dominated by sorption in lampblack (KLB-C) to absorption in oil tar (Ktar), depending on the fraction of tar (ftar). This study illustrates the importance of understanding interactions among PAHs, oil tar, and lampblack for explaining the differences in availability of PAHs among site soils and, consequently, for refining site-specific risk assessment and establishing soil cleanup levels. PMID:17373502

  16. Fluorine concentration in snow cover within the impact area of aluminium production plant (Krasnoyarsk city) and coal and gas-fired power plant (Tomsk city)

    NASA Astrophysics Data System (ADS)

    Talovskaya, A. V.; Osipova, N. A.; Filimonenko, E. A.; Polikanova, S. A.; Samokhina, N. P.; Yazikov, E. G.; Matveenko, I. A.

    2015-11-01

    The fluorine contents in snow melt water find in the impact areas of aluminum production plant and coal and gas-fired power plant are compared. In melt water, soluble fluoride is found in the form of fluoride ion, the content of which was determined by the potentiometric method using ion-selective electrode. According to the measurements of 2013-2014, fluoride content in melt water ranges 10.6-15.4 mg/dm3 at the distance 1-3 km from the borders of Krasnoyarsk aluminum plant with the mean value 13.1 mg/dm3. Four-year monitoring from 2012 to 2015 in the impact area of Tomsk coal and gas-fired power plant showed that fluoride content in melt water in vicinity of the thermal power plant is significantly lower than in the samples from the impact area of the aluminum plant. But higher content of fluoride ion (0.2 - 0.3 mg/dm3) in snow samples in vicinity of coal and gas-fired power plant was revealed in winter of 2015. Intake of soluble fluoride is mostly explained by dust-aerosol emissions of study plants and deposition of fluorine compounds from air.

  17. Dissolved organic carbon (DOC) and select aldehydes in cloud and fog water: the role of the aqueous phase in impacting trace gas budgets

    NASA Astrophysics Data System (ADS)

    Ervens, B.; Wang, Y.; Eagar, J.; Leaitch, W. R.; Macdonald, A. M.; Valsaraj, K. T.; Herckes, P.

    2012-12-01

    Cloud and fog droplets efficiently scavenge and process water-soluble compounds and thus modify the chemical composition of the gas and particle phases. The concentrations of dissolved organic carbon (DOC) in the aqueous phase reach concentrations on the order of ~10 mg C L-1 which is typically on the same order of magnitude as the sum of inorganic anions. Aldehydes and carboxylic acids typically comprise a large fraction of DOC because of their high solubility. The dissolution of species in the aqueous phase can lead to (i) the removal of species from the gas phase preventing their processing by gas phase reactions (e.g. photolysis of aldehydes) and (ii) the formation of unique products that do not have any efficient gas phase sources (e.g. dicarboxylic acids). We present measurements of DOC and select aldehydes in fog water at high elevation and intercepted clouds in a biogenically-impacted location (Whistler, Canada) and in fog water in a more polluted area (Davis, CA). Concentrations of formaldehyde, glyoxal and methylglyoxal were in the micromolar range and comprised ≤2% each individually of the DOC. Comparison of the DOC and aldehyde concentrations to those at other locations shows good agreement and reveals highest levels for both in anthropogenically impacted regions. Based on this overview, we conclude that the fraction of organic carbon (dissolved and insoluble inclusions) in the aqueous phase comprises 1-~40% of total organic carbon. Higher values are observed to be associated with aged air masses where organics are expected to be more highly oxidized and thus more soluble. Accordingly, the aqueous/gas partitioning ratio expressed here as an effective Henry's law constant for DOC (KH*DOC) increases by an order of magnitude from 7×103 M atm-1 to 7×104 M atm-1 during the ageing of air masses. The measurements are accompanied by photochemical box model simulations. They suggest that the scavenging of aldehydes by the aqueous phase can reduce HO2 gas

  18. 75 FR 67997 - Notice of Correction to Notice of Intent To Prepare an Environmental Impact Statement for the Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-04

    ... Uranium Project, Fremont and Natrona Counties, Wyoming (75 FR 54384). The notice inadvertently contained an incorrect legal land description. The correct legal land description for the Gas Hills Uranium... Statement for the Gas Hills Uranium Project, Fremont and Natrona Counties, WY AGENCY: Bureau of...

  19. 77 FR 2513 - Draft Environmental Impact Statement for Effects of Oil and Gas Activities in the Arctic Ocean

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... Effects of Oil and Gas Activities in the Arctic Ocean AGENCY: National Marine Fisheries Service (NMFS... the Effects of Oil and Gas Activities in the Arctic Ocean.'' Based on several written requests... the Notice of Availability (76 FR 82275, December 30, 2011). Public Meetings Comments will be...

  20. Landowner Attitudes and Perceptions of Impact from Wind and Natural Gas Development in Northern Pennsylvania: Implications for Energy Landscapes in Rural America

    NASA Astrophysics Data System (ADS)

    Jacquet, Jeffrey Bryan

    Energy developments such as industrial scale wind farms and unconventional natural gas drilling represent some of the largest and most controversial land use changes occurring in the United States today. A diverse array of academic disciplines have each sought to explain the social, psychological, and economic effects of siting large industrial facilities in rural areas, however the research has largely remained discipline-specific. This study measures resident attitudes and perceptions of impact from both wind and gas drilling occurring simultaneously in the Armenia Mountain Area of northern Pennsylvania. The results of a mail survey of landowners (n = 1028) in this study area reveal factors that explain landowner variation in attitudes and perception of impact, and describe new forms of participation in the planning and siting of these energy projects. Direction is provided for a new and synthetic theoretical understanding of how residents perceive these impacts and impacts from land use change. The work advances “risk of social and psychological disruption” as a key factor that may influence how residents respond to the prospect of large land use changes. Implications for the regulation and planning of these energy sources are offered, including a new understanding of how landowners participate in the planning and siting of large energy projects. Finally, the limitations of this work, as well as opportunities and implications for future research, are discussed.

  1. Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.

    PubMed

    Luk, Jason M; Saville, Bradley A; MacLean, Heather L

    2015-04-21

    This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31 000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits. PMID:25825338

  2. Impact of arterial blood gas analysis in disability evaluation of the bituminous coal miner with simple pneumoconiosis

    SciTech Connect

    Fields, C.L.; Roy, T.M.; Dow, F.T.; Anderson, W.H. )

    1992-04-01

    The Department of Labor has set guidelines for the use of resting arterial blood gas analysis in determination of total and permanent disability for coal workers' pneumoconiosis. To determine the prevalence with which bituminous coal miners fall below the arterial tensions of both oxygen and carbon dioxide published in the Federal Register, we studied 1012 miners who had both reproducible spirometry and arterial blood gas analysis as part of their disability evaluation. Eighty-seven percent of impaired miners could be identified by the spirometric criteria. Thirteen percent of impaired bituminous coal miners had acceptable pulmonary function but were eligible for black lung benefits by the blood gas guidelines. This population would have been missed if blood gas analysis were excluded from the evaluation process. On the other hand, approximately 25% of the blood gas analyses that were performed could be eliminated if a policy was adopted to do this test only on miners with spirometry that exceed the federal guidelines.

  3. Influence of Biochar on C and N Transformation in Soil and Their Impact on Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Chintala, R.; Schumacher, T. E.; Kumar, S.; Clay, D. E.; Malo, D. D.

    2014-12-01

    (microbial biomass N, inorganic N, and δ 15N). Greenhouse gas fluxes (CO2, CH4, and N2O) were measured and correlation studies will be conducted to determine the relationship with the interference effect of biochars on C and N transformation in soil. Initial data shows that biochar has an impact especially on CO2, and N2O emissions.

  4. Numerical Simulation of Subsurface Transport and Groundwater Impacts from Hydraulic Fracturing of Tight/Shale Gas Reservoirs

    NASA Astrophysics Data System (ADS)

    Reagan, M. T.; Moridis, G. J.; Keen, N. D.

    2014-12-01

    The use of reservoir stimulation techniques, such as hydraulic fracturing, has grown tremendously over the last decade, and concerns have arisen that reservoir stimulation creates environmental threats through the creation of permeable pathways that could connect the stimulated reservoir to shallower groundwater aquifers. This study investigates, by numerical simulation, gas and water transport between a deeper tight-gas reservoir and a shallower overlying groundwater aquifer following hydraulic fracturing operations, assuming that the formation of a connecting pathway has already occurred. We focus on two general transport scenarios: 1) communication between the reservoir and aquifer via a connecting fracture or fault and 2) communication via a deteriorated, preexisting nearby well. The simulations explore a range of permeabilities and geometries over time scales, and evaluate the mechanisms and factors that could lead to the escape of gas or reservoir fluid and the contamination of groundwater resources. We also examine the effects of overpressured reservoirs, and explore long-term transport processes as part of a continuing study. We conclude that the key factors driving short-term transport of gas include high permeability for the connecting pathway and the overall volume of the connecting feature. Gas production from the reservoir via a horizontal well is likely to mitigate release through the reduction of available free gas and the lowering of reservoir pressure. We also find that fractured tight-gas reservoirs are unlikely to act as a continuing source of large volumes of migrating gas, and incidents of gas escape are likely to be limited in duration and scope. Reliable field and laboratory data must be acquired to constrain the factors and determine the likelihood of these outcomes.

  5. Determination of 14 benzodiazepines and hydroxy metabolites, zaleplon and zolpidem as tert-butyldimethylsilyl derivatives compared with other common silylating reagents in whole blood by gas chromatography-mass spectrometry.

    PubMed

    Gunnar, Teemu; Ariniemi, Kari; Lillsunde, Pirjo

    2005-04-25

    The most common commercially available silylating reagents, N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA), N,O-bis-(trimethylsilyl)trifluoroacetamide+1% trimethylchlorosilane (BSTFA+1% TMCS) and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) were evaluated to achieve optimal derivatization conditions for analyzing various benzodiazepines based on gas chromatography-electron impact ionization-mass spectrometry (GC-EI-MS). Sensitivity, repeatability, retention times and stability of the derivatives, as well as specificity of mass fragmentation, were studied in detail. Also other parameters affecting the derivatization chemistry of benzodiazepines are discussed. tert-Butyldimethylsilyl (TBDMS) derivatives proved to be more stable, reproducible and sensitive than corresponding trimethylsilyl (TMS) derivatives for the GC-EI-MS analysis of benzodiazepines. Based on the TBDMS derivatives, a rapid, reliable, sensitive and quantitative GC-MS method was developed for the determination of 14 benzodiazepines and two hydroxy metabolites, as well as two non-benzodiazepine hypnotic agents, zolpidem and zaleplon, using 50 microl of whole blood. The method was completely validated in terms of accuracy, intra- and interday precision, limit of detection (LOD), limit of quantitation (LOQ), linearity, selectivity and extraction efficiency; these were all within the required limits, except for the accuracy of nitrazepam at a medium concentration level. PMID:15734157

  6. Source Apportionment of Volatile Organic Compounds and PM2.5 Using Positive Matrix Factorization in Two National Parks Impacted by Oil and Natural Gas Drilling Operations

    NASA Astrophysics Data System (ADS)

    Evanoski-Cole, A.; Prenni, A. J.; Sive, B. C.; Zhou, Y.; Benedict, K. B.; Day, D.; Schurman, M. I.; Sullivan, A.; Li, Y.; Callahan, S. L.; Hand, J. L.; Gebhart, K. A.; Schichtel, B. A.; Fischer, E. V.; Collett, J. L., Jr.

    2015-12-01

    As the oil and natural gas industry expands into rural areas of the United States, it is becoming increasingly important to investigate its impact on air quality in nearby national parks and other protected federal lands. Data from two different field studies centered in Rocky Mountain National Park, Colorado and the north unit of Theodore Roosevelt National Park, North Dakota will be used to perform a comprehensive source apportionment study. Measurements at both locations include volatile organic compounds (VOCs), PM2.5 and their precursor gases, and meteorological variables. Both sites are located near concentrated oil and natural gas operations but other local and regional emission sources differ. Other potential sources near Theodore Roosevelt National Park include increased diesel truck traffic, coal fired power plants and road dust. Rocky Mountain National Park is impacted by the transport of emissions from urban centers and agriculture in eastern Colorado. Additionally, the study at Theodore Roosevelt National Park occurred over two consecutive winters and the measurements at Rocky Mountain National Park were collected during the summer. Using these field study data and the EPA positive matrix factorization (PMF) tool, the different source factors for each field site will be investigated. In particular, the differences in the oil and gas factor from each study location will be discussed.

  7. Method of evaluating the impact of ERP implementation critical success factors - a case study in oil and gas industries

    NASA Astrophysics Data System (ADS)

    Gajic, Gordana; Stankovski, Stevan; Ostojic, Gordana; Tesic, Zdravko; Miladinovic, Ljubomir

    2014-01-01

    The so far implemented enterprise resource planning (ERP) systems have in many cases failed to meet the requirements regarding the business process control, decrease of business costs and increase of company profit margin. Therefore, there is a real need for an evaluation of the influence of ERP on the company's performance indicators. Proposed in this article is an advanced model for the evaluation of the success of ERP implementation on organisational and operational performance indicators in oil-gas companies. The recommended method establishes a correlation between a process-based method, a scorecard model and ERP critical success factors. The method was verified and tested on two case studies in oil-gas companies using the following procedure: the model was developed, tested and implemented in a pilot gas-oil company, while the results were implemented and verified in another gas-oil company.

  8. 78 FR 65637 - Sierrita Gas Pipeline LLC; Notice of Availability of the Draft Environmental Impact Statement for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

    ...-inch-diameter natural gas pipeline in Pima County, Arizona; two meter stations; two pig launchers and two pig receivers; \\1\\ and \\1\\ A pig is an internal tool that can be used to clean and dry a...

  9. Results of the California Healthy Homes Indoor Air Quality Study of 2011-2013: Impact of natural gas appliances on air pollutant concentrations

    SciTech Connect

    Mullen, Nasim A.; Li, Jina; Russell, Marion L.; Spears, Michael; Less, Brennan D.; Singer, Brett C.

    2015-03-17

    This study was conducted to assess the current impact of natural gas appliances on air quality in California homes. Data were collected via telephone interviews and measurements inside and outside of 352 homes. Passive samplers measured time-resolved CO and time-integrated NOX, NO2, formaldehyde, and acetaldehyde over ~6d periods in November 2011 - April 2012 and October 2012 - March 2013. The fraction of indoor NOX and NO2 attributable to indoor sources was estimated. NOX, NO2 and highest 1-h CO were higher in homes that cooked with gas and increased with amount of gas cooking. NOX and NO2 were higher in homes with cooktop pilot burners, relative to gas cooking without pilots. Homes with a pilot burner on a floor or wall furnace had higher kitchen and bedroom NOX and NO2 compared to homes without a furnace pilot. When scaled to account for varying home size and mixing volume, indoor-attributed bedroom and kitchen NOX and kitchen NO2 were not higher in homes with wall or floor furnace pilot burners, though bedroom NO2 was higher. In homes that cooked 4 h or more with gas, self-reported use of kitchen exhaust was associated with lower NOX, NO2 and highest 1-h CO. Gas appliances were not associated with higher concentrations of formaldehyde or acetaldehyde.

  10. Impact of gas chromatography and mass spectrometry combined with gas chromatography and olfactometry for the sex differentiation of Baccharis articulata by the analysis of volatile compounds.

    PubMed

    Minteguiaga, Manuel; Umpiérrez, Noelia; Fariña, Laura; Falcão, Manuel A; Xavier, Vanessa B; Cassel, Eduardo; Dellacassa, Eduardo

    2015-09-01

    The Baccharis genus has more than 400 species of aromatic plants. However, only approximately 50 species have been studied in oil composition to date. From these studies, very few take into consideration differences between male and female plants, which is a significant and distinctive factor in Baccharis in the Asteraceae family. Baccharis articulata is a common shrub that grows wild in south Brazil, northern and central Argentina, Bolivia, Paraguay and Uruguay. It is considered to be a medicinal plant and is employed in traditional medicine. We report B. articulata male and female volatile composition obtained by simultaneous distillation-extraction technique and analyzed by gas chromatography with mass spectrometry. Also, an assessment of aromatic differences between volatile extracts was evaluated by gas chromatography with olfactometry. The results show a very similar chemical composition between male and female extracts, with a high proportion of terpene compounds of which β-pinene, limonene and germacrene D are the main components. Despite the chemical similarity, great differences in aromatic profile were found: male plant samples exhibited the strongest odorants in number and intensity of aromatic attributes. These differences explain field observations which indicate differences between male and female flower aroma, and might be of ecological significance in the attraction of pollinating insects. PMID:26140379

  11. Impact of the etching gas on vertically oriented single wall and few walled carbon nanotubes by plasma enhanced chemical vapor deposition

    SciTech Connect

    Gohier, A.; Minea, T. M.; Djouadi, M. A.; Granier, A.

    2007-03-01

    Vertically oriented single wall nanotubes (SWNTs) and few walled nanotubes (FWNTs) have been grown by electronic cyclotron resonance plasma enhanced chemical vapor deposition (PECVD) on silica flat substrates. The impact of the plasma parameters on SWNT and FWNT growth has been investigated using two different etching gas mixtures, namely, C{sub 2}H{sub 2}/NH{sub 3} and C{sub 2}H{sub 2}/H{sub 2} with various ratios and applied bias voltages. Kinetic studies are also proposed in order to describe the FWNT growth mechanism by plasma techniques. A key role played by the reactive gas (NH{sub 3} and H{sub 2}) is observed in the PECVD process, contrary to multiwalled nanotube growth. It is demonstrated that the balance between FWNT growth versus FWNT etching can be widely modulated by varying the gas mixture and bias voltage. It is shown that the use of hydrogen for hydrocarbon gas dilution restricts the destruction of SWNT and FWNT by the plasma species (ions and radicals)

  12. Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California

    SciTech Connect

    Ganji, A. . Div. of Engineering)

    1992-07-01

    Residential space and water heating accounts for approximately 12% of California's and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

  13. Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California. Final report

    SciTech Connect

    Ganji, A.

    1992-07-01

    Residential space and water heating accounts for approximately 12% of California`s and 15% of the United States, energy consumption. most Of the residential heating is by direct use of natural gas. combustion of natural gas is a contributor to the overall air pollution,, especially CO and NO{sub x} in the urban areas. Another efficient method for domestic water and space heating is use of electric heat pumps, the most popular category of which uses air as its heat source. Electric heat pumps do not emit air pollutants at the point of use, but use electric power, which is a major contributor to air pollution at its point of generation from fossil fuels. It is the specific objective of this report to evaluate and compare the energy efficiency and source air pollutants of natural gas heaters and electric heat pumps used for domestic heating. Effect of replacing natural gas heaters with electric heat pumps on air pollutant emissions due to domestic heating in two urban areas and in California as a whole has also been evaluated. The analysis shows that with the present state of technology, electric heat pumps have higher heating efficiencies than natural gas heaters. Considering the current electricity generation mix in the US, electric heat pumps produce two to four times more NO{sub x}, much less CO, and comparable amount of CO{sub 2} per unit of useful heating energy compared to natural gas heaters. With California mix, electric heat pumps produce comparable NO{sub x} and much less CO and approximately 30% less CO{sub 2} per unit heat output. Replacement of natural gas heaters with electric heat pumps will slightly increase the overall NO{sub x}, and reduce CO and CO{sub 2} emissions in California. The effect of advanced technology power generation and heat pump heating has also been analyzed.

  14. Impact of hot fluid advection on hydrocarbon gas production and seepage in mud volcano sediments of thick Cenozoic deltas

    NASA Astrophysics Data System (ADS)

    Nuzzo, Marianne; Elvert, Marcus; Schmidt, Mark; Scholz, Florian; Reitz, Anja; Hinrichs, Kai-Uwe; Hensen, Christian

    2012-08-01

    Hydrocarbon seeps are ubiquitous at gas-prone Cenozoic deltas such as the Nile Deep Sea Fan (NDSF) On the contrary at the periphery, a lower but sustained CH4 flux is indicated by deeper sulphate-methane transition zones and the presence of 13C-depleted biomarkers of AOM, consistent with predominantly immature organic matter. Values of δ13C-CH4∼-60‰VPDB and decreased concentrations of 13C-enriched C2+ are typical of mixed microbial CH4 and biodegraded thermogenic gas from Plio-Pleistocene reservoirs of the region. The maturity of gas condensate migrated from pre-Miocene sources into Miocene reservoirs of the Western NDSF is higher than that of the gas vented at the centre of NAMV, supporting the hypothesis that it is rather released from the degradation of oil in Neogene reservoirs. Combined with the finding of hot pore water and petroleum at the centre, our results suggest that clay mineral dehydration of Neogene sediments, which takes place posterior to reservoir filling, may contribute to intense gas generation at high sedimentation rate deltas.

  15. The impact of plasma-wall interaction on the gas mixing efficiency in electron cyclotron resonance ion source

    SciTech Connect

    Schachter, L.; Dobrescu, S.; Stiebing, K. E.

    2012-02-15

    It is generally accepted that different effects are necessary to explain the gas mixing method of increasing the output of highly charged ions from an ECRIS. The two most important effects are the mass effect and the dilution effect. Their relative weights have not been determined experimentally yet, but it is generally assumed that the mass effect is dominant in standard ECRIS installations with stainless steel plasma chambers. In order to gain more insight into the physics of the gas mixing effect and in particular on the relevance of the dilution process, we have carried out a study where we have investigated the role of the plasma-wall interaction on the gas mixing effect. In this contribution, we shall discuss Charge state distributions spectra, measured at the Frankfurt ECRIS using different working gases, pure argon, a mixture of argon and oxygen, and argon mixed with neon.

  16. Regional air quality impacts of hydraulic fracturing and shale natural gas activity: Evidence from ambient VOC observations

    NASA Astrophysics Data System (ADS)

    Vinciguerra, Timothy; Yao, Simon; Dadzie, Joseph; Chittams, Alexa; Deskins, Thomas; Ehrman, Sheryl; Dickerson, Russell R.

    2015-06-01

    Over the past decade, concentrations of many anthropogenic pollutants have been successfully reduced, improving air quality. However, a new influx of emissions associated with hydraulic fracturing and shale natural gas operations could be counteracting some of these benefits. Using hourly measurements from Photochemical Assessment Monitoring Stations (PAMS) in the Baltimore, MD and Washington, DC areas, we observed that following a period of decline, daytime ethane concentrations have increased significantly since 2010, growing from ∼7% of total measured nonmethane organic carbon to ∼15% in 2013. This trend appears to be linked with the rapidly increasing natural gas production in upwind, neighboring states, especially Pennsylvania and West Virginia. Ethane concentrations failed to display this trend at a PAMS site outside of Atlanta, GA, a region without new widespread natural gas operations.

  17. Impact of routine episodic emissions on the expected frequency distribution of emissions from oil and gas production sources.

    NASA Astrophysics Data System (ADS)

    Smith, N.; Blewitt, D.; Hebert, L. B.

    2015-12-01

    In coordination with oil and gas operators, we developed a high resolution (< 1 min) simulation of temporal variability in well-pad oil and gas emissions over a year. We include routine emissions from condensate tanks, dehydrators, pneumatic devices, fugitive leaks and liquids unloading. We explore the variability in natural gas emissions from these individual well-pad sources, and find that routine short-term episodic emissions such as tank flashing and liquids unloading result in the appearance of a skewed, or 'fat-tail' distribution of emissions, from an individual well-pad over time. Additionally, we explore the expected variability in emissions from multiple wells with different raw gas composition, gas/liquids production volumes and control equipment. Differences in well-level composition, production volume and control equipment translate into differences in well-level emissions leading to a fat-tail distribution of emissions in the absence of operational upsets. Our results have several implications for recent studies focusing on emissions from oil and gas sources. Time scale of emission estimates are important and have important policy implications. Fat tail distributions may not be entirely driven by avoidable mechanical failures, and are expected to occur under routine operational conditions from short-duration emissions (e.g., tank flashing, liquid unloading). An understanding of the expected distribution of emissions for a particular population of wells is necessary to evaluate whether the observed distribution is more skewed than expected. Temporal variability in well-pad emissions make comparisons to annual average emissions inventories difficult and may complicate the interpretation of long-term ambient fenceline monitoring data. Sophisticated change detection algorithms will be necessary to identify when true operational upsets occur versus routine short-term emissions.

  18. The impact of flue gas cleaning technologies in coal-fired power plants on the CCN distribution and cloud properties in Germany

    NASA Astrophysics Data System (ADS)

    Bangert, M.; Vogel, B.; Junkermann, W.; Brachert, L.; Schaber, K.

    2013-05-01

    Gas-cleaning technologies used in modern coal-fired power plants cause an unintended nucleation of H2SO4 aerosol droplets during the cleaning process. As a result, high concentrations of ultra-fine aerosol droplets are emitted into the atmosphere. In this study, the impact of these emissions on the atmospheric aerosol distribution, on the cloud condensation nuclei number concentration, and consequently on cloud properties is investigated. Therefore, a sophisticated modeling framework is used combining regional simulations of the atmospheric aerosol distribution and its impact on cloud properties with detailed process simulations of the nucleation during the cleaning process inside the power plant. Furthermore, the simulated aerosol size distributions downwind of the coal-fired power plants are compared with airborne aerosol measurements performed inside the plumes.

  19. Single microparticle launching method using two-stage light-gas gun for simulating hypervelocity impacts of micrometeoroids and space debris

    SciTech Connect

    Kawai, Nobuaki; Tsurui, Kenji; Hasegawa, Sunao; Sato, Eiichi

    2010-11-15

    A single microparticle launching method is described to simulate the hypervelocity impacts of micrometeoroids and microdebris on space structures at the Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency. A microparticle placed in a sabot with slits is accelerated using a rifled two-stage light-gas gun. The centrifugal force provided by the rifling in the launch tube separates the sabot. The sabot-separation distance and the impact-point deviation are strongly affected by the combination of the sabot diameter and the bore diameter, and by the projectile diameter. Using this method, spherical projectiles of 1.0-0.1 mm diameter were launched at up to 7 km/s.

  20. Single microparticle launching method using two-stage light-gas gun for simulating hypervelocity impacts of micrometeoroids and space debris.

    PubMed

    Kawai, Nobuaki; Tsurui, Kenji; Hasegawa, Sunao; Sato, Eiichi

    2010-11-01

    A single microparticle launching method is described to simulate the hypervelocity impacts of micrometeoroids and microdebris on space structures at the Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency. A microparticle placed in a sabot with slits is accelerated using a rifled two-stage light-gas gun. The centrifugal force provided by the rifling in the launch tube separates the sabot. The sabot-separation distance and the impact-point deviation are strongly affected by the combination of the sabot diameter and the bore diameter, and by the projectile diameter. Using this method, spherical projectiles of 1.0-0.1 mm diameter were launched at up to 7 km/s. PMID:21133499

  1. CO2 utilization and storage in shale gas reservoirs: Experimental results and economic impacts

    SciTech Connect

    Schaef, Herbert T.; Davidson, Casie L.; Owen, Antionette Toni; Miller, Quin R. S.; Loring, John S.; Thompson, Christopher J.; Bacon, Diana H.; Glezakou, Vassiliki Alexandra; McGrail, B. Peter

    2014-12-31

    Natural gas is considered a cleaner and lower-emission fuel than coal, and its high abundance from advanced drilling techniques has positioned natural gas as a major alternative energy source for the U.S. However, each ton of CO2 emitted from any type of fossil fuel combustion will continue to increase global atmospheric concentrations. One unique approach to reducing anthropogenic CO2 emissions involves coupling CO2 based enhanced gas recovery (EGR) operations in depleted shale gas reservoirs with long-term CO2 storage operations. In this paper, we report unique findings about the interactions between important shale minerals and sorbing gases (CH4 and CO2) and associated economic consequences. Where enhanced condensation of CO2 followed by desorption on clay surface is observed under supercritical conditions, a linear sorption profile emerges for CH4. Volumetric changes to montmorillonites occur during exposure to CO2. Theory-based simulations identify interactions with interlayer cations as energetically favorable for CO2 intercalation. Thus, experimental evidence suggests CH4 does not occupy the interlayer and has only the propensity for surface adsorption. Mixed CH4:CO2 gas systems, where CH4 concentrations prevail, indicate preferential CO2 sorption as determined by in situ infrared spectroscopy and X-ray diffraction techniques. Collectively, these laboratory studies combined with a cost-based economic analysis provide a basis for identifying favorable CO2-EOR opportunities in previously fractured shale gas reservoirs approaching final stages of primary gas production. Moreover, utilization of site-specific laboratory measurements in reservoir simulators provides insight into optimum injection strategies for maximizing CH4/CO2 exchange rates to obtain peak natural

  2. Using a two-layered sphere model to investigate the impact of gas vacuoles on the inherent optical properties of Microcystis aeruginosa

    NASA Astrophysics Data System (ADS)

    Matthews, M. W.; Bernard, S.

    2013-12-01

    A two-layered sphere model is used to investigate the impact of gas vacuoles on the inherent optical properties (IOPs) of the cyanophyte Microcystis aeruginosa. Enclosing a vacuole-like particle within a chromatoplasm shell layer significantly altered spectral scattering and increased backscattering. The two-layered sphere model reproduced features in the spectral attenuation and volume scattering function (VSF) that have previously been attributed to gas vacuoles. This suggests the model is good at least as a first approximation for investigating how gas vacuoles alter the IOPs. Measured Rrs was used to provide a range of values for the central value of the real refractive index, 1 + ɛ, for the shell layer using measured IOPs and a radiative transfer model. Sufficient optical closure was obtained for 1 + ɛ between 1.1 and 1.14, which had corresponding Chl a-specific phytoplankton backscattering, bbφ*, between 3.9 and 7.2 × 10-3 m2 mg-1 at 510 nm. The bbφ* values are in close agreement with the literature and in situ particulate backscattering measurements. Rrs simulated for a population of vacuolate cells was greatly enlarged relative to a homogeneous population. A sensitivity analysis of empirical algorithms for estimating Chl a in eutrophic/hypertrophic waters suggests these are robust under variable constituent concentrations and likely to be species-sensitive. The study confirms that gas vacuoles cause significant increase in backscattering and are responsible for the high Rrs values observed in buoyant cyanobacterial blooms. Gas vacuoles are therefore one of the most important bio-optical substructures influencing the IOPs in phytoplankton.

  3. Using a two-layered sphere model to investigate the impact of gas vacuoles on the inherent optical properties of M. aeruginosa

    NASA Astrophysics Data System (ADS)

    Matthews, M. W.; Bernard, S.

    2013-06-01

    A two-layered sphere model is used to investigate the impact of gas vacuoles on the inherent optical properties (IOPs) of the cyanophyte Microcystis aeruginosa. Enclosing a vacuole-like particle within a chromatoplasm shell layer significantly altered spectral scattering and increased backscattering. The two-layered sphere model reproduced features in the spectral attenuation and volume scattering function (VSF) that have previously been attributed to gas vacuoles. This suggests the model is good at least as a first approximation for investigating how gas vacuoles alter the IOPs. The central value of the real refractive index, 1+ ɛ, for the shell layer was determined using a radiative transfer model and measured remote sensing reflectance, Rrs, and IOP data. For a cell with 50% vacuole volume, the mean 1+ ɛ value for the shell layer was 1.12. The corresponding chl a specific phytoplankton backscattering coefficient, bbφ*, ranged between 3.9 × 10-3 and 7.2 × 10-3 m2 mg-1 at 510 nm. This agrees closely with in situ particulate backscattering measurements and values reported elsewhere. Rrs simulated for a population of vacuolate cells was greatly enlarged relative to a homogeneous population. Empirical algorithms based on Rrs were derived for estimating chl a in eutrophic/hypertrophic waters dominated by M. aeruginosa. The study confirms that gas vacuoles cause significant increase in backscattering and are responsible for the high Rrs values observed in buoyant cyanobacterial blooms. Gas vacuoles are therefore one of the most important bio-optical substructures influencing the IOPs in phytoplankton.

  4. How Deep is the Critical Zone: A Scientific Question with Potential Impact For Decision-makers in Areas of Shale-Gas Development and Hydraulic Fracturing

    NASA Astrophysics Data System (ADS)

    Brantley, S. L.

    2014-12-01

    Citizens living in areas of shale-gas development such as the Marcellus gas play in Pennsylvania and surrounding states are cognizant of the possibility that drilling and production of natural gas -- including hydraulic fracturing -- may have environmental impacts on their water. The Critical Zone is defined as the zone from vegetation canopy to the lower limits of groundwater. This definition is nebulous in terms of the lower limit, and yet, defining the bottom of the Critical Zone is important if citizens are to embrace shale-gas development. This is because, although no peer-reviewed study has been presented that documents a case where hydraulic fracturing or formation fluids have migrated upwards from fracturing depths to drinking water resources, a few cases of such leakage have been alleged. On the other hand, many cases of methane migration into aquifers have been documented to occur and some have been attributed to shale-gas development. The Critical Zone science community has a role to play in understanding such contamination problems, how they unfold, and how they should be ameliorated. For example, one big effort of the Critical Zone science community is to promote sharing of data describing the environment. This data effort has been extended to provide data for citizens to understand water quality by a team known as the Shale Network. As scientists learn to publish data online, these efforts must also be made accessible to non-scientists. As citizens access the data, the demand for data will grow and all branches of government will eventually respond by providing more accessible data that will help the public and policy-makers make decisions.

  5. Dissolved organic carbon (DOC) and select aldehydes in cloud and fog water: the role of the aqueous phase in impacting trace gas budgets

    NASA Astrophysics Data System (ADS)

    Ervens, B.; Wang, Y.; Eagar, J.; Leaitch, W. R.; Macdonald, A. M.; Valsaraj, K. T.; Herckes, P.

    2013-05-01

    Cloud and fog droplets efficiently scavenge and process water-soluble compounds and, thus, modify the chemical composition of the gas and particle phases. The concentrations of dissolved organic carbon (DOC) in the aqueous phase reach concentrations on the order of ~ 10 mgC L-1 which is typically on the same order of magnitude as the sum of inorganic anions. Aldehydes and carboxylic acids typically comprise a large fraction of DOC because of their high solubility. The dissolution of species in the aqueous phase can lead to (i) the removal of species from the gas phase preventing their processing by gas phase reactions (e.g., photolysis of aldehydes) and (ii) the formation of unique products that do not have any efficient gas phase sources (e.g., dicarboxylic acids). We present measurements of DOC and select aldehydes in fog water at high elevation and intercepted clouds at a biogenically-impacted location (Whistler, Canada) and in fog water in a more polluted area (Davis, CA). Concentrations of formaldehyde, glyoxal and methylglyoxal were in the micromolar range and comprised ≤ 2% each individually of the DOC. Comparison of the DOC and aldehyde concentrations to those at other locations shows good agreement and reveals highest levels for both in anthropogenically impacted regions. Based on this overview, we conclude that the fraction of organic carbon (dissolved and insoluble inclusions) in the aqueous phase of clouds or fogs, respectively, comprises 2-~ 40% of total organic carbon. Higher values are observed to be associated with aged air masses where organics are expected to be more highly oxidised and, thus, more soluble. Accordingly, the aqueous/gas partitioning ratio expressed here as an effective Henry's law constant for DOC (KH*DOC) increases by an order of magnitude from 7 × 103 M atm-1 to 7 × 104 M atm-1 during the ageing of air masses. The measurements are accompanied by photochemical box model simulations. These simulations are used to contrast two

  6. Explicit Finite Element Modeling of Multilayer Composite Fabric for Gas Turbine Engine Containment Systems. Part 2; Ballistic Impact Testing

    NASA Technical Reports Server (NTRS)

    Pereira, J. M.; Revilock, D. M.

    2004-01-01

    Under the Federal Aviation Administration's Airworthiness Assurance Center of Excellence and the Aircraft Catastrophic Failure Prevention Program, National Aeronautics and Space Administration Glenn Research Center collaborated with Arizona State University, Honeywell Engines, Systems and Services, and SRI International to develop improved computational models for designing fabric-based engine containment systems. In the study described in this report, ballistic impact tests were conducted on layered dry fabric rings to provide impact response data for calibrating and verifying the improved numerical models. This report provides data on projectile velocity, impact and residual energy, and fabric deformation for a number of different test conditions.

  7. [Health and environmental licensing: a methodological proposal for assessment of the impact of the oil and gas industry].

    PubMed

    Barbosa, Eduardo Macedo; Barata, Matha Macedo de Lima; Hacon, Sandra de Souza

    2012-02-01

    Bearing in mind the importance of the impacts of the oil industry on human health, this article seeks to present a methodological proposal for analysis of these aspects in environmental impact assessment studies, based on the established legal parameters and a validated matrix for the hydroelectric sector. The lack of health considerations in the environmental impact assessment was detected in most of the 21 oil production enterprises analyzed, that were licensed in the period from January 1, 2004 through October 30, 2009. The health matrix proved to be an appropriate methodological approach to analyze these aspects in the environmental licensing process, guiding decisions and interventions in socio-environmental management. PMID:22267026

  8. Impacts of prior land use and increased corn acreage on life cycle assessment of net greenhouse gas flux

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the increased demand for corn ethanol, farmers are expected to plant the largest corn acreage in the United States since 1944. One of the main reasons for producing corn ethanol is the reduced greenhouse gas (GHG) emissions compared with gasoline. However, quantifying the offset of GHG emission...

  9. Impact of alternative n fertilizer sources on cotton yield and greenhouse gas emissions in a coastal plain soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in the use of alternative fertilizer sources have increased in recent years. This is partially attributed to the belief that the new enhanced-efficiency N fertilizer sources can potentially increase crop yield, while at the same time decreasing greenhouse gas emissions. Thus, a field stud...

  10. 75 FR 4427 - Pacific Gas & Electric Company; Notice of Intent To Prepare an Environmental Impact Statement and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... was published in the Federal Register on December 11, 2009 (74 FR 65811). A notice of acceptance for... Conduct the Scoping Process for Diablo Canyon Nuclear Power Plant, Units 1 and 2 Pacific Gas & Electric... opportunity to participate in the environmental scoping process, as defined in 10 CFR 51.29. In addition,...

  11. Impact of using high-density polyethylene geomembrane layer as landfill intermediate cover on landfill gas extraction.

    PubMed

    Chen, Zezhi; Gong, Huijuan; Zhang, Mengqun; Wu, Weili; Liu, Yu; Feng, Jin

    2011-05-01

    Clay is widely used as a traditional cover material for landfills. As clay becomes increasingly costly and scarce, and it also reduces the storage capacity of landfills, alternative materials with low hydraulic conductivity are employed. In developing countries such as China, landfill gas (LFG) is usually extracted for utilization during filling stage, therefore, the intermediate covering system is an important part in a landfill. In this study, a field test of LFG extraction was implemented under the condition of using high-density polyethylene (HDPE) geomembrane layer as the only intermediate cover on the landfill. Results showed that after welding the HDPE geomembranes together to form a whole airtight layer upon a larger area of landfill, the gas flow in the general pipe increased 25% comparing with the design that the HDPE geomembranes were not welded together, which means that the gas extraction ability improved. However as the heat isolation capacity of the HDPE geomembrane layer is low, the gas generation ability of a shallow landfill is likely to be weakened in cold weather. Although using HDPE geomembrane layer as intermediate cover is acceptable in practice, the management and maintenance of it needs to be investigated in order to guarantee its effective operation for a long term. PMID:21232931

  12. Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (ERD)

    EPA Science Inventory

    In this report, EPA reviews and synthesizes scientific literature to assess the potential for hydraulic fracturing for oil and gas to change the quality or quantity of drinking water resources. This report also identifies factors affecting the frequency or severity of any potenti...

  13. Impact of gas/particle partitioning of semivolatile organic compounds on source apportionment with positive matrix factorization.

    PubMed

    Xie, Mingjie; Hannigan, Michael P; Barsanti, Kelley C

    2014-08-19

    To quantify and minimize the influence of gas/particle (G/P) partitioning on receptor-based source apportionment using particle-phase semivolatile organic compound (SVOC) data, positive matrix factorization (PMF) coupled with a bootstrap technique was applied to three data sets mainly composed of "measured-total" (measured particle- + gas-phase), "particle-only" (measured particle-phase) and "predicted-total" (measured particle-phase + predicted gas-phase) SVOCs to apportion carbonaceous aerosols. Particle- (PM2.5) and gas-phase SVOCs were collected using quartz fiber filters followed by PUF/XAD-4/PUF adsorbents and measured using gas chromatography-mass spectrometry (GC-MS). Concentrations of gas-phase SVOCs were also predicted from their particle-phase concentrations using absorptive partitioning theory. Five factors were resolved for each data set, and the factor profiles were generally consistent across the three PMF solutions. Using a previous source apportionment study at the same receptor site, those five factors were linked to summertime biogenic emissions (odd n-alkane factor), unburned fossil fuels (light SVOC factor), road dust and/or cooking (n-alkane factor), motor vehicle emissions (PAH factor), and lubricating oil combustion (sterane factor). The "measured-total" solution was least influenced by G/P partitioning and used as reference. Two out of the five factors (odd n-alkane and PAH factors) exhibited consistent contributions for "particle-only" vs "measured-total" and "predicted-total" vs "measured-total" solutions. Factor contributions of light SVOC and n-alkane factors were more consistent for "predicted-total" vs "measured-total" than "particle-only" vs "measured-total" solutions. The remaining factor (sterane factor) underestimated the contribution by around 50% from both "particle-only" and "predicted-total" solutions. The results of this study confirm that when measured gas-phase SVOCs are not available, "predicted-total" SVOCs should be used

  14. Quantification of physical and economic impacts of climate change on public infrastructure in Alaska and benefits of global greenhouse gas mitigation

    NASA Astrophysics Data System (ADS)

    Melvin, A. M.; Larsen, P.; Boehlert, B.; Martinich, J.; Neumann, J.; Chinowsky, P.; Schweikert, A.; Strzepek, K.

    2015-12-01

    Climate change poses many risks and challenges for the Arctic and sub-Arctic, including threats to infrastructure. The safety and stability of infrastructure in this region can be impacted by many factors including increased thawing of permafrost soils, reduced coastline protection due to declining arctic sea ice, and changes in inland flooding. The U.S. Environmental Protection Agency (EPA) is coordinating an effort to quantify physical and economic impacts of climate change on public infrastructure across the state of Alaska and estimate how global greenhouse gas (GHG) mitigation may avoid or reduce these impacts. This research builds on the Climate Change Impacts and Risk Analysis (CIRA) project developed for the contiguous U.S., which is described in an EPA report released in June 2015. We are using a multi-model analysis focused primarily on the impacts of changing permafrost, coastal erosion, and inland flooding on a range of infrastructure types, including transportation (e.g. roads, airports), buildings and harbors, energy sources and transmission, sewer and water systems, and others. This analysis considers multiple global GHG emission scenarios ranging from a business as usual future to significant global action. These scenarios drive climate projections through 2100 spanning a range of outcomes to capture variability amongst climate models. Projections are being combined with a recently developed public infrastructure database and integrated into a version of the Infrastructure Planning Support System (IPSS) we are modifying for use in the Arctic and sub-Arctic region. The IPSS tool allows for consideration of both adaptation and reactive responses to climate change. Results of this work will address a gap in our understanding of climate change impacts in Alaska, provide estimates of the physical and economic damages we may expect with and without global GHG mitigation, and produce important insights about infrastructure vulnerabilities in response to

  15. Golden age of gas and its impact on the world energy, the global carbon cycle and climate

    NASA Astrophysics Data System (ADS)

    Tereshin, A. G.; Klimenko, A. V.; Klimenko, V. V.

    2015-05-01

    Global and regional resource and environmental problems of production and use of unconventional gas (UG) are studied. Estimations for world and national reserves of various kinds of UG are presented. The dynamics of the gas share in total energy consumption and thermal power generation around the world is analyzed. Projections of the world production of conventional gas and UG are proposed. Variations in carbon dioxide concentration in the atmosphere and the corresponding changes in average global air temperature are calculated for various scenarios suggesting unconventional gas substitution of different energy sources. The possible consequences of expected climate changes for Russia's power industry are analyzed. It is shown that, despite the uncertainty in the estimates of the economic and environmental consequences of shale gas (SG) production, its use, according to the available resource estimates, can make it possible to solve global and regional problems associated with energy (import substitution) and environment protection (replacing the less clean coal fuel). However, the development of the huge global resources of this type of fuel can have a significant effect on the chemical and thermal radiative balance of the Earth's atmosphere, and it must be noted that the climatic effect of carbon dioxide emissions from the UG combustion greatly exceeds the consequences of methane leakage during its production. In order to sustain the stability of the global climate system, the development of the world's large UG resources must be accompanied by an equivalent reduction in the use of coal. This is the only way for UG to become a safe energy bridge to the future, able to keep the climate system at the threshold of critical values. Direct effects of possible climatic changes on the territory of Russia for the domestic energy complex are estimated as more positive than adverse, mainly due to lower energy costs for space heating.

  16. Analysis of Restricted Natural Gas Supply Cases

    EIA Publications

    2004-01-01

    The four cases examined in this study have progressively greater impacts on overall natural gas consumption, prices, and supply. Compared to the Annual Energy Outlook 2004 reference case, the no Alaska pipeline case has the least impact; the low liquefied natural gas case has more impact; the low unconventional gas recovery case has even more impact; and the combined case has the most impact.

  17. Fundamental insights on impact of non-condensible gas evolution from coating pyrolysis and intentional injection on molten-aluminum water explosion onset during direct-chill casting

    SciTech Connect

    Taleyarkhan, R.P.; Kim, S.H.; Gulec, K.

    1998-05-01

    Explosive interactions between molten aluminum and water are being studied with a focus on fundamentals to determine what causes robust-enough triggers for explosion onset, to determine the extent of protection provided from various coatings and to develop a fundamentally-based simple, cost-effective novel methodology for prevention. The workscope includes experimentation and mathematical modeling of the interactions between molten metals and water at various different coated and uncoated surfaces. Phenomenological issues related to surface wettability, gas generation from coatings, charring of coatings, inertial constraint, melt temperature, water temperature, external shocks are being investigated systematically to gage their relative impact on the triggerability of surface-assisted steam explosions. The steam explosion triggering studies (SETS) facility was designed and constructed as a rapid-turnaround, cost-effective, and safe means to address these phenomenological issues. Data from SETS tests have indicated that, non-condensible gas (NCG) generation during paint pyrolysis plays a predominant role in explosion prevention. This paper describes results of studies on impact of deliberate NCG injection on explosion prevention, via molten melt drops free-falling into water, as well as from tests using the SETS facility for studying entrapment induced explosive boiling. SETS is also being used to obtain information on time-varying and integral amounts of NCGs generated from various paints. Relevant data are presented. Results of investigations, taken together provide compelling evidence on the positive role NCGs play on explosion prevention.

  18. An integrated approach for the evaluation of technological hazard impacts on air quality: the case of the Val d'Agri oil/gas plant

    NASA Astrophysics Data System (ADS)

    Calvello, M.; Esposito, F.; Trippetta, S.

    2014-08-01

    The Val d'Agri area (southern Italy) hosts one of the biggest onshore European reservoir and the largest oil/gas pre-treatment plant, named Centro Olio Val d'Agri (COVA), located in a rural/anthropized context. Several hazards are associated with this plant. These are mainly represented by possible impacts of the COVA atmospheric emissions on the local air quality and human health. This work uses a novel approach based on the integration of air quality measurements from the regional monitoring network, additional experimental measurements (i.e. sub-micrometre particulate matter (PM1) and black carbon (BC)) and advanced statistical analyses to provide a preliminary evaluation of the Val d'Agri air quality state and give some indication of specific areas potentially affected by COVA hazards. Results show that the COVA plant emissions have a particular impact on the air quality of the area closest to it. In this area several pollutants specifically related to the COVA combustion processes (i.e. nitrogen oxides, benzene and toluene) show the highest concentration values and significant correlations. The proposed approach represents a first step in the assessment of the risks associated with oil/gas exploration and pre-treatment activities and a starting point for the development of effective and exportable air quality monitoring strategies.

  19. An integrated approach for the evaluation of technological hazard impacts on air quality: the case of the Val d'Agri oil/gas plant

    NASA Astrophysics Data System (ADS)

    Calvello, M.; Esposito, F.; Trippetta, S.

    2014-04-01

    The Val d'Agri area (southern Italy) hosts the biggest on-shore European reservoir and the largest oil/gas pre-treatment plant, named Centro Olio Val d'Agri (COVA), located in a rural/anthropized context. Several hazards are associated to this plant. These are mainly represented by possible impacts of the COVA atmospheric emissions on the local air quality and human health. This work uses a novel approach based on the integration of air quality measurements from the regional monitoring network, additional experimental measurements (i.e., sub-micrometric particulate matter - PM1 and Black Carbon - BC) and advanced statistical analyses to provide a preliminary evaluation of the Val d'Agri air quality state and give some indications of specific areas potentially affected by COVA hazards. Results show that the COVA plant emissions exert an impact especially on the air quality of the area closest to it. In this area several pollutants specifically related to the COVA combustion processes (i.e., nitrogen oxides, benzene and toluene) show the highest concentration values and significant correlations. The proposed approach represents a first step in the assessment of the risks associated to oil/gas exploration and pre-treatment activities and a starting point for the development of effective and exportable air quality monitoring strategies.

  20. A system to damp the free piston oscillations in a two-stage light-gas gun used for hypervelocity impact experiments

    NASA Astrophysics Data System (ADS)

    Pavarin, D.; Francesconi, A.; Angrilli, F.

    2004-01-01

    Hypervelocity impact experiments that reproduce on-orbit collisions between micrometeoroids or orbital debris and space structures are commonly performed by means of propellant-driven two-stage light-gas guns. Such devices accelerate projectiles using the thrust of a light propellant gas that is compressed to high pressure and temperature by a piston running in a pump tube. Though these guns have the unique capability of accelerating particles up to 9 km/s, many components of the gun must be checked and/or substituted after each shot making test sessions long and expensive. In order to have a lot of and many different types of hypervelocity impact data, the Center of Studies and activities for Space CISAS "G. Colombo" of Padua University developed a high-shot-frequency two-stage light-gas gun that can increase the shot repetition rate of standard facilities by a factor of 5 or more and at the same time reduce the shot cost by a factor of 2 or more. This is made possible through the use of special mechanical and diagnostic solutions that were designed to operate the gun for more than 50 shots in sequence without having to carry out maintenance operations. This article presents the design and operation of the CISAS two-stage light-gas gun damping system, which is one of the subsystems that makes it possible to achieve high-shot frequency. The damping system is in charge of controlling the piston oscillations in the pump tube, making it possible for the piston to withstand more than 100 shots without any damage. In particular, the damping system avoids piston strikes onto the gun head at the end of each compression stroke and allows the piston to be positioned at the base of the pump tube after each shot. The sensitivity of the piston oscillations to the damping operations and main subsystem design parameters were identified using numerical simulations, carried out according to a model that describes every working phase of the gun. Moreover, in this paper, the

  1. Impacts of European livestock production: nitrogen, sulphur, phosphorus and greenhouse gas emissions, land-use, water eutrophication and biodiversity

    NASA Astrophysics Data System (ADS)

    Leip, Adrian; Billen, Gilles; Garnier, Josette; Grizzetti, Bruna; Lassaletta, Luis; Reis, Stefan; Simpson, David; Sutton, Mark A.; de Vries, Wim; Weiss, Franz; Westhoek, Henk

    2015-11-01

    Livestock production systems currently occupy around 28% of the land surface of the European Union (equivalent to 65% of the agricultural land). In conjunction with other human activities, livestock production systems affect water, air and soil quality, global climate and biodiversity, altering the biogeochemical cycles of nitrogen, phosphorus and carbon. Here, we quantify the contribution of European livestock production to these major impacts. For each environmental effect, the contribution of livestock is expressed as shares of the emitted compounds and land used, as compared to the whole agricultural sector. The results show that the livestock sector contributes significantly to agricultural environmental impacts. This contribution is 78% for terrestrial biodiversity loss, 80% for soil acidification and air pollution (ammonia and nitrogen oxides emissions), 81% for global warming, and 73% for water pollution (both N and P). The agriculture sector itself is one of the major contributors to these environmental impacts, ranging between 12% for global warming and 59% for N water quality impact. Significant progress in mitigating these environmental impacts in Europe will only be possible through a combination of technological measures reducing livestock emissions, improved food choices and reduced food waste of European citizens.

  2. Application of new parameterizations of gas transfer velocity and their impact on regional and global marine CO 2 budgets

    NASA Astrophysics Data System (ADS)

    Fangohr, Susanne; Woolf, David K.

    2007-06-01

    One of the dominant sources of uncertainty in the calculation of air-sea flux of carbon dioxide on a global scale originates from the various parameterizations of the gas transfer velocity, k, that are in use. Whilst it is undisputed that most of these parameterizations have shortcomings and neglect processes which influence air-sea gas exchange and do not scale with wind speed alone, there is no general agreement about their relative accuracy. The most widely used parameterizations are based on non-linear functions of wind speed and, to a lesser extent, on sea surface temperature and salinity. Processes such as surface film damping and whitecapping are known to have an effect on air-sea exchange. More recently published parameterizations use friction velocity, sea surface roughness, and significant wave height. These new parameters can account to some extent for processes such as film damping and whitecapping and could potentially explain the spread of wind-speed based transfer velocities published in the literature. We combine some of the principles of two recently published k parameterizations [Glover, D.M., Frew, N.M., McCue, S.J. and Bock, E.J., 2002. A multiyear time series of global gas transfer velocity from the TOPEX dual frequency, normalized radar backscatter algorithm. In: Donelan, M.A., Drennan, W.M., Saltzman, E.S., and Wanninkhof, R. (Eds.), Gas Transfer at Water Surfaces, Geophys. Monograph 127. AGU,Washington, DC, 325-331; Woolf, D.K., 2005. Parameterization of gas transfer velocities and sea-state dependent wave breaking. Tellus, 57B: 87-94] to calculate k as the sum of a linear function of total mean square slope of the sea surface and a wave breaking parameter. This separates contributions from direct and bubble-mediated gas transfer as suggested by Woolf [Woolf, D.K., 2005. Parameterization of gas transfer velocities and sea-state dependent wave breaking. Tellus, 57B: 87-94] and allows us to quantify contributions from these two processes

  3. LARGE-SCALE SHOCK-IONIZED AND PHOTOIONIZED GAS IN M83: THE IMPACT OF STAR FORMATION

    SciTech Connect

    Hong, Sungryong; Calzetti, Daniela; Dopita, Michael A.; Blair, William P.; Whitmore, Bradley C.; Bond, Howard E.; Balick, Bruce; Carollo, Marcella; Disney, Michael J.; Frogel, Jay A.; Hall, Donald; Holtzman, Jon A.; Kimble, Randy A.; McCarthy, Patrick J.; O'Connell, Robert W.; Paresce, Francesco; Saha, Abhijit; Silk, Joseph I.; Trauger, John T.; Walker, Alistair R.

    2011-04-10

    We investigate the ionization structure of the nebular gas in M83 using the line diagnostic diagram, [O III](5007 A)/H{beta} versus [S II](6716 A+6731 A)/H{alpha}, with the newly available narrowband images from the Wide Field Camera 3 (WFC3) of the Hubble Space Telescope (HST). We produce the diagnostic diagram on a pixel-by-pixel (0.''2 x 0.''2) basis and compare it with several photo- and shock-ionization models. We select four regions from the center to the outer spiral arm and compare them in the diagnostic diagram. For the photoionized gas, we observe a gradual increase of the log ([O III]/H{beta}) ratios from the center to the spiral arm, consistent with the metallicity gradient, as the H II regions go from super-solar abundance to roughly solar abundance from the center out. Using the diagnostic diagram, we separate the photoionized from the shock-ionized component of the gas. We find that the shock-ionized H{alpha} emission ranges from {approx}2% to about 15%-33% of the total, depending on the separation criteria used. An interesting feature in the diagnostic diagram is a horizontal distribution around log ([O III]/H{beta}) {approx} 0. This feature is well fit by a shock-ionization model with 2.0 Z{sub sun} metallicity and shock velocities in the range of 250-350 km s{sup -1}. A low-velocity shock component, <200 km s{sup -1}, is also detected and is spatially located at the boundary between the outer ring and the spiral arm. The low-velocity shock component can be due to (1) supernova remnants located nearby, (2) dynamical interaction between the outer ring and the spiral arm, and (3) abnormal line ratios from extreme local dust extinction. The current data do not enable us to distinguish among those three possible interpretations. Our main conclusion is that, even at the HST resolution, the shocked gas represents a small fraction of the total ionized gas emission at less than 33% of the total. However, it accounts for virtually all of the mechanical

  4. Large-scale Shock-ionized and Photoionized Gas in M83: The Impact of Star Formation

    NASA Astrophysics Data System (ADS)

    Hong, Sungryong; Calzetti, Daniela; Dopita, Michael A.; Blair, William P.; Whitmore, Bradley C.; Balick, Bruce; Bond, Howard E.; Carollo, Marcella; Disney, Michael J.; Frogel, Jay A.; Hall, Donald; Holtzman, Jon A.; Kimble, Randy A.; McCarthy, Patrick J.; O'Connell, Robert W.; Paresce, Francesco; Saha, Abhijit; Silk, Joseph I.; Trauger, John T.; Walker, Alistair R.; Windhorst, Rogier A.; Young, Erick T.; Mutchler, Max

    2011-04-01

    We investigate the ionization structure of the nebular gas in M83 using the line diagnostic diagram, [O III](5007 Å)/Hβ versus [S II](6716 Å+6731 Å)/Hα, with the newly available narrowband images from the Wide Field Camera 3 (WFC3) of the Hubble Space Telescope (HST). We produce the diagnostic diagram on a pixel-by-pixel (0farcs2 × 0farcs2) basis and compare it with several photo- and shock-ionization models. We select four regions from the center to the outer spiral arm and compare them in the diagnostic diagram. For the photoionized gas, we observe a gradual increase of the log ([O III]/Hβ) ratios from the center to the spiral arm, consistent with the metallicity gradient, as the H II regions go from super-solar abundance to roughly solar abundance from the center out. Using the diagnostic diagram, we separate the photoionized from the shock-ionized component of the gas. We find that the shock-ionized Hα emission ranges from ~2% to about 15%-33% of the total, depending on the separation criteria used. An interesting feature in the diagnostic diagram is a horizontal distribution around log ([O III]/Hβ) ≈ 0. This feature is well fit by a shock-ionization model with 2.0 Z sun metallicity and shock velocities in the range of 250-350 km s-1. A low-velocity shock component, <200 km s-1, is also detected and is spatially located at the boundary between the outer ring and the spiral arm. The low-velocity shock component can be due to (1) supernova remnants located nearby, (2) dynamical interaction between the outer ring and the spiral arm, and (3) abnormal line ratios from extreme local dust extinction. The current data do not enable us to distinguish among those three possible interpretations. Our main conclusion is that, even at the HST resolution, the shocked gas represents a small fraction of the total ionized gas emission at less than 33% of the total. However, it accounts for virtually all of the mechanical energy produced by the central starburst in M83.

  5. Do SNC Noble Gas and Deuterium Data Provide Evidence for Large Cometary Impact Between 1300 300 Ma on Mars?

    NASA Astrophysics Data System (ADS)

    Bodiselitsch, B.; Lammer, H.

    2004-03-01

    Martian meteorites data show a nearly stable Martian atmosphere between 3.9 and 1.3 Gyr, but markedly changes in the Ar/Kr/Xe ratios and D/H ratios between 1.3 and 0.3 Gyr. These changes could have been triggered by a cometary impact.

  6. Impact of Reduced Tillage and Cover Cropping on the Greenhouse Gas Budget of a Maize/Soybean Rotation Ecosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the impact of an alternative management scenario (reduced tillage and cover cropping) on ecosystem respiration and N2O and CH4 exchange in a maize (Zea mays L)/soybean (Glycine max L.) rotation agroecosystem in north-central Minnesota. The control treatmen...

  7. 75 FR 6175 - Notice of Intent to Prepare an Environmental Impact Statement on the Effects of Oil and Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... (DPEIS) and a schedule of public hearings (72 FR 17117) to assess the impacts of MMS' issuance of permits.... Therefore, MMS and NMFS filed a Notice of Withdrawal of the DPEIS on October 28, 2009 (74 FR 55539) and... incidental to offshore exploration activities (e.g., seismic surveys and exploratory drilling) in Federal...

  8. The impact of wet flue gas desulfurization scrubbing on mercury emissions from coal-fired power stations

    SciTech Connect

    Stephen Niksa; Naoki Fujiwara

    2005-07-01

    The article introduces a predictive capability for mercury (Hg) retention in any Ca-based wet flue gas desulfurization (FGD) scrubber, given Hg speciation at the FGD inlet, the flue gas composition, and the sulphur dioxide (SO{sub 2}) capture efficiency. A preliminary statistical analysis of data from 17 full-scale wet FGDs connects flue gas compositions, the extents of Hg oxidation at FGD inlets, and Hg retention efficiencies. These connections show that solution chemistry within the FGD determines Hg retention. A more thorough analysis based on thermochemical equilibrium yields highly accurate predictions for total Hg retention with no parameter adjustments. For the most reliable data, the predictions were within measurement uncertainties for both limestone and Mg/lime systems operating in both forced and natural oxidation mode. With the U.S. Environmental Protection Agency's (EPA) Information Collection Request (ICR) database, the quantitative performance was almost as good for the most modern FGDs, which probably conform to the very high SO{sub 2} absorption efficiencies assumed in the calculations. The large discrepancies for older FGDs are tentatively attributed to the unspecified SO{sub 2} capture efficiencies and operating temperatures and to the possible elimination of HCl in prescrubbers. The equilibrium calculations suggest that Hg retention is most sensitive to inlet HCl and O{sub 2} levels and the FGD temperature; weakly dependent on SO{sub 2} capture efficiency; and insensitive to HgCl{sub 2}, NO, CA:S ratio, slurry dilution level in limestone FGDs, and MgSO{sub 3} levels in Mg/lime systems. Consequently, systems with prescrubbers to eliminate HCl probably retain less Hg than fully integrated FGDs. The analysis also predicts re-emission of Hg{sub 0} but only for inlet O{sub 2} levels that are much lower than those in full-scale FGDs. 12 refs., 5 figs., 3 tabs.

  9. The impact of wet flue gas desulfurization scrubbing on mercury emissions from coal-fired power stations.

    PubMed

    Niksa, Stephen; Fujiwara, Naoki

    2005-07-01

    This article introduces a predictive capability for Hg retention in any Ca-based wet flue gas desulfurization (FGD) scrubber, given mercury (Hg) speciation at the FGD inlet, the flue gas composition, and the sulphur dioxide (SO2) capture efficiency. A preliminary statistical analysis of data from 17 full-scale wet FGDs connects flue gas compositions, the extents of Hg oxidation at FGD inlets, and Hg retention efficiencies. These connections clearly signal that solution chemistry within the FGD determines Hg retention. A more thorough analysis based on thermochemical equilibrium yields highly accurate predictions for total Hg retention with no parameter adjustments. For the most reliable data, the predictions were within measurement uncertainties for both limestone and Mg/lime systems operating in both forced and natural oxidation mode. With the U.S. Environmental Protection Agency's (EPA) Information Collection Request (ICR) database, the quantitative performance was almost as good for the most modern FGDs, which probably conform to the very high SO2 absorption efficiencies assumed in the calculations. The large discrepancies for older FGDs are tentatively attributed to the unspecified SO2 capture efficiencies and operating temperatures and to the possible elimination of HCl in prescrubbers. The equilibrium calculations suggest that Hg retention is most sensitive to inlet HCl and O2 levels and the FGD temperature; weakly dependent on SO2 capture efficiency; and insensitive to HgCl2, NO, CA:S ratio, slurry dilution level in limestone FGDs, and MgSO3 levels in Mg/lime systems. Consequently, systems with prescrubbers to eliminate HCl probably retain less Hg than fully integrated FGDs. The analysis also predicts re-emission of Hg(O) but only for inlet O2 levels that are much lower than those in full-scale FGDs. PMID:16111136

  10. Impact of alternative fuels on emissions characteristics of a gas turbine engine - part 2: volatile and semivolatile particulate matter emissions.

    PubMed

    Williams, Paul I; Allan, James D; Lobo, Prem; Coe, Hugh; Christie, Simon; Wilson, Christopher; Hagen, Donald; Whitefield, Philip; Raper, David; Rye, Lucas

    2012-10-01

    The work characterizes the changes in volatile and semivolatile PM emissions from a gas turbine engine resulting from burning alternative fuels, specifically gas-to-liquid (GTL), coal-to-liquid (CTL), a blend of Jet A-1 and GTL, biodiesel, and diesel, to the standard Jet A-1. The data presented here, compares the mass spectral fingerprints of the different fuels as measured by the Aerodyne high resolution time-of-flight aerosol mass spectrometer. There were three sample points, two at the exhaust exit plane with dilution added at different locations and another probe located 10 m downstream. For emissions measured at the downstream probe when the engine was operating at high power, all fuels produced chemically similar organic PM, dominated by C(x)H(y) fragments, suggesting the presence of long chain alkanes. The second largest contribution came from C(x)H(y)O(z) fragments, possibly from carbonyls or alcohols. For the nondiesel fuels, the highest loadings of organic PM were from the downstream probe at high power. Conversely, the diesel based fuels produced more organic material at low power from one of the exit plane probes. Differences in the composition of the PM for certain fuels were observed as the engine power decreased to idle and the measurements were made closer to the exit plane. PMID:22913312

  11. The impact of economic activity in Asturias on greenhouse gas emissions: consequences for environmental policy within the Kyoto Protocol framework.

    PubMed

    Argüelles, Margarita; Benavides, Carmen; Junquera, Beatriz

    2006-11-01

    Climate change is one of the major worldwide environmental concerns. It is especially the case in many developed countries, where the greenhouse gas emissions responsible for this change are mainly concentrated. For the first time, the Kyoto Protocol includes an international agreement for the reduction of the net emissions of these gases. To fulfil this agreement measures designed to reduce or limit current emissions have to be brought into force. Consequently, fears have arisen about possible consequences on competitiveness and future development of manufacturing activities and the need for support mechanisms for the affected sectors is obvious. In this paper, we carry out a study of the emissions of gases responsible for climate change in Asturias (Spain), a region with an important economic presence of sectors with intensive emissions of CO(2), the chief greenhouse gas. To be precise, in the first place, the volumes of direct emissions of the said gases in 1995 were calculated, showing that the sectors most affected by the Kyoto Protocol in Asturias are iron and steel and electricity production. Secondly, input-output analysis was applied to determine the direct and indirect emissions and the direct, indirect and induced emissions of the different production sectors, respectively. The results derived from the direct and indirect emissions analysis and their comparison with the results of the former allow us to reach some conclusions and environmental policy implications. PMID:16556480

  12. NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES

    SciTech Connect

    Singer, Brett C.; Apte, Michael G.; Black, Douglas R.; Hotchi, Toshifumi; Lucas, Donald; Lunden, Melissa M.; Mirer, Anna G.; Spears, Michael; Sullivan, Douglas P.

    2009-12-01

    The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine) particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. The baseline fuel was Northern California line gas with Wobbe number (a measure of fuel energy delivery rate) of 1320-1340; test fuels had Wobbe numbers of roughly 1390 and 1420, and in some cases 1360. No ignition or operational problems were observed during test fuel use. Baseline emissions varied widely across and within burner groups and with burner operational mode. Statistically significant emissions changes were observed for some pollutants on some burners.

  13. Impact of Dynamic Loading on the Implant-abutment Interface Using a Gas-enhanced Permeation Test In Vitro

    PubMed Central

    Al-Jadaa, Anas; Attin, Thomas; Peltomäki, Timo; Heumann, Christian; Schmidlin, Patrick Roger

    2015-01-01

    Purpose : To assess implant leakage under static conditions as well as during and after dynamic loading. Materials and methods : Implants (Astra Tech (A), Biomet 3i (B) and Nobel Biocare (C)) were evaluated for leakage (n=8/group). Testing to assess the gas pressure change over time (hPa/min) and infiltrated fluid volume, was performed in a Gas Enhanced Permeation Test (GEPT) to qualify embedding. Implant apexes were then drilled, abutments were mounted and resin build-ups were fabricated. GEPT was reassessed. Samples were afterward mounted in a computer-controlled masticator while tested to bacterial leakage, they were daily observed for turbidity. Samples were then reassessed using GEPT. Dunnett's and Fisher's exact tests were utilized to compare implant and to analyze bacterial leakage. Results : Significant differences in GEPT values were shown after loading (p=0.034). Leakage resistance was best for B when compared to C (p=0.023). Samples with higher GEPT values demonstrated earlier bacterial leakage, occurring after 1 or 2 days (A=4, B=0, C=6) and showing favorability for implant system B (p=0.009). Conclusion : Implants leaking under static conditions had increased potential for bacterial leakage under dynamic conditions. As strongly correlating to sophisticated analytical methods, GEPT is a promising technique for assessing the overall implant system leakage resistance. PMID:25870719

  14. Incineration of animal by-products--The impact of selected parameters on the flux of flue gas enthalpy.

    PubMed

    Bujak, Janusz; Sitarz, Piotr

    2016-04-01

    This paper presents model analyses and tests of animal by-product waste thermal treatment plants. A schedule of tests was prepared, and 62,024 cases of system operation were analysed. A map/work field of the tested plant was drawn up on the basis thereof. Calculations were made following an algorithm described by Bujak (2015a) written in the VBA (Visual Basic for Application) language. The tests showed that when incinerating animal waste, the flux of physical enthalpy of the flue gas from the afterburner chamber depends on numerous design and operating parameters. The most important include the following: humidity and flux of the waste, concentration of oxygen in the flue gas in the afterburner chamber and loss of heat flux to the atmosphere through the external surfaces of the plant. Individual design and operating parameters can be selected so that the process of incineration is ensured without additional fuel. The performed analyses were verified against the actual object at the industrial scale using a meat plant that manufactures ham and processes beef, pork and poultry with a capacity of 150 tonnes/day. The production process waste included mainly bones and - in much smaller quantities - meat and bone meal, at 17 tonnes/day. The performed tests and analyses can be used to optimise the operation of the waste thermal treatment plant at the stages of design and operation. PMID:26926784

  15. Effect of placements (horizontal with vertical) on gas-solid flow and particle impact erosion in gate valve

    NASA Astrophysics Data System (ADS)

    Lin, Zhe; Zhu, Linhang; Cui, Baoling; Li, Yi; Ruan, Xiaodong

    2014-12-01

    Gate valve has various placements in the practical usages. Due to the effect of gravity, particle trajectories and erosions are distinct between placements. Thus in this study, gas-solid flow properties and erosion in gate valve for horizontal placement and vertical placement are discussed and compared by using Euler-Lagrange simulation method. The structure of a gate valve and a simplified structure are investigated. The simulation procedure is validated in our published paper by comparing with the experiment data of a pipe and an elbow. The results show that for all investigated open degrees and Stokes numbers (St), there are little difference of gas flow properties and flow coefficients between two placements. It is also found that the trajectories of particles for two placements are mostly identical when St « 1, making the erosion independent of placement. With the increase of St, the distinction of trajectories between placements becomes more obvious, leading to an increasing difference of the erosion distributions. Besides, the total erosion ratio of surface T for horizontal placement is two orders of magnitudes larger than that for vertical placement when the particle diameter is 250μm.

  16. Potential impacts of electric power production utilizing natural gas, renewables and carbon capture and sequestration on US Freshwater resources.

    PubMed

    Tidwell, Vincent C; Malczynski, Leonard A; Kobos, Peter H; Klise, Geoffrey T; Shuster, Erik

    2013-08-01

    Carbon capture and sequestration (CCS) has important implications relative to future thermoelectric water use. A bounding analysis is performed using past greenhouse gas emission policy proposals and assumes either all effected capacity retires (lower water use bound) or is retrofitted (upper bound). The analysis is performed in the context of recent trends in electric power generation expansion, namely high penetration of natural gas and renewables along with constrained cooling system options. Results indicate thermoelectric freshwater withdrawals nationwide could increase by roughly 1% or decrease by up to 60% relative to 2009 levels, while consumption could increase as much as 21% or decrease as much as 28%. To identify where changes in freshwater use might be problematic at a regional level, electric power production has been mapped onto watersheds with limited water availability (where consumption exceeds 70% of gauged streamflow). Results suggest that between 0.44 and 0.96 Mm(3)/d of new thermoelectric freshwater consumption could occur in watersheds with limited water availability, while power plant retirements in these watersheds could yield 0.90 to 1.0 Mm(3)/d of water savings. PMID:23789965

  17. Impact of Oxy-Fuel Conditions on Elemental Mercury Re-Emission in Wet Flue Gas Desulfurization Systems.

    PubMed

    Fernández-Miranda, Nuria; Lopez-Anton, M Antonia; Torre-Santos, Teresa; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

    2016-07-01

    This study evaluates some of the variables that may influence mercury retention in wet flue gas desulfurization (WFGD) plants, focusing on oxy-coal combustion processes and differences when compared with atmospheres enriched in N2. The main drawback of using WFGD for mercury capture is the possibility of unwanted reduction of dissolved Hg(2+), leading to the re-emission of insoluble elemental mercury (Hg(0)), which decreases efficiency. To acquire a better understanding of the mercury re-emission reactions in WFGD systems, this work analyses different variables that influence the behavior of mercury in slurries obtained from two limestones, under an oxy-combustion atmosphere. The O2 supplied to the reactor, the influence of the pH, the concentration of mercury in the gas phase, and the enhancement of mercury in the slurry were the variables considered. The study was performed at laboratory scale, where possible reactions between the components in the scrubber can be individually evaluated. It was found that in an oxy-combustion atmosphere (mostly CO2), the re-emission of Hg(0) is lower than under a N2-enriched atmosphere, and the mercury is mainly retained as Hg(2+) in the liquid phase. PMID:27329988

  18. Direct analysis of sulfate reducing bacterial communities in gas hydrate-impacted marine sediments by PCR-DGGE.

    PubMed

    Bagwell, Christopher E; Formolo, Michael; Ye, Qi; Yeager, Chris M; Lyons, Timothy W; Zhang, Chuanlun L

    2009-09-01

    Molecular investigations of the sulfate reducing bacteria that target the dissimilatory sulfite-reductase subunit A gene (dsr A) are plagued by the nonspecific performance of conventional PCR primers. Here we describe the incorporation of the FailSafe PCR System to optimize environmental analysis of dsr A by PCR amplification and denaturing gradient gel electrophoresis. PCR-DGGE analysis of dsr A composition revealed that SRB diversity was greater and more variable throughout the vertical profile of a marine sediment core obtained from a gas hydrate site (GC234) in the Gulf of Mexico than in a sediment core collected from a nearby site devoid of gas hydrates (NBP). Depth profiled dsr B abundance corresponded with sulfate reduction rates at both sites, though measurements were higher at GC234. This study exemplifies the numerical and functional importance of sulfate reducing bacteria in deep-sea sedimentary environments, and incremental methodological advancements, as described herein, will continue to streamline the analysis of sulfate reducer communities in situ. PMID:19322839

  19. Comparison of impacts on macroinvertebrates and fish from gas pipeline installation by wet-ditching and plowing

    SciTech Connect

    Vinikour, W.S.; Schubert, J.P.; Gartman, D.K.

    1987-01-01

    Biotic effects from wet-ditching were investigated at the Little Miami River, Ohio. Invertebrate densities decreased at, and a short distance below, the crossing site; partial benthic recolonization occurred within three weeks of construction, while complete recolonization occurred within seven months. Fish recolonized the affected area within one month, but densities were reduced; within eight months after construction, the fish community was similar to that observed before construction. Biotic effects from the plow method were examined at Canada Creek, Michigan. No significant impacts on benthic macroinvertebrates were detected. During ramp excavation, increased macroinvertebrate drift densities were noted, as well as increased occurrence of terrestrial invertebrates in the drift; upon completion of ramp excavation, drift composition approximated that before construction. No effects on fish species were indicated. Overall, no biotic impacts were detected within three days after pipeline installation. 23 refs., 4 figs., 3 tabs.

  20. Strengthening of oxidation resistant materials for gas turbine applications. [treatment of silicon ceramics for increased flexural strength and impact resistance

    NASA Technical Reports Server (NTRS)

    Kirchner, H. P.

    1974-01-01

    Silicon nitride and silicon carbide ceramics were treated to form compressive surface layers. On the silicon carbide, quenching and thermal exposure treatments were used, and on the silicon nitride, quenching, carburizing, and a combination of quenching and carburizing were used. In some cases substantial improvements in impact resistance and/or flexural strength were observed. The presence of compressive surface stresses was demonstrated by slotted rod tests.

  1. Toward an Understanding of the Environmental and Public Health Impacts of Unconventional Natural Gas Development: A Categorical Assessment of the Peer-Reviewed Scientific Literature, 2009-2015

    PubMed Central

    Hays, Jake; Shonkoff, Seth B. C.

    2016-01-01

    The body of science evaluating the potential impacts of unconventional natural gas development (UNGD) has grown significantly in recent years, although many data gaps remain. Still, a broad empirical understanding of the impacts is beginning to emerge amidst a swell of research. The present categorical assessment provides an overview of the peer-reviewed scientific literature from 2009–2015 as it relates to the potential impacts of UNGD on public health, water quality, and air quality. We have categorized all available original research during this time period in an attempt to understand the weight and direction of the scientific literature. Our results indicate that at least 685 papers have been published in peer-reviewed scientific journals that are relevant to assessing the impacts of UNGD. 84% of public health studies contain findings that indicate public health hazards, elevated risks, or adverse health outcomes; 69% of water quality studies contain findings that indicate potential, positive association, or actual incidence of water contamination; and 87% of air quality studies contain findings that indicate elevated air pollutant emissions and/or atmospheric concentrations. This paper demonstrates that the weight of the findings in the scientific literature indicates hazards and elevated risks to human health as well as possible adverse health outcomes associated with UNGD. There are limitations to this type of assessment and it is only intended to provide a snapshot of the scientific knowledge based on the available literature. However, this work can be used to identify themes that lie in or across studies, to prioritize future research, and to provide an empirical foundation for policy decisions. PMID:27096432

  2. Toward an Understanding of the Environmental and Public Health Impacts of Unconventional Natural Gas Development: A Categorical Assessment of the Peer-Reviewed Scientific Literature, 2009-2015.

    PubMed

    Hays, Jake; Shonkoff, Seth B C

    2016-01-01

    The body of science evaluating the potential impacts of unconventional natural gas development (UNGD) has grown significantly in recent years, although many data gaps remain. Still, a broad empirical understanding of the impacts is beginning to emerge amidst a swell of research. The present categorical assessment provides an overview of the peer-reviewed scientific literature from 2009-2015 as it relates to the potential impacts of UNGD on public health, water quality, and air quality. We have categorized all available original research during this time period in an attempt to understand the weight and direction of the scientific literature. Our results indicate that at least 685 papers have been published in peer-reviewed scientific journals that are relevant to assessing the impacts of UNGD. 84% of public health studies contain findings that indicate public health hazards, elevated risks, or adverse health outcomes; 69% of water quality studies contain findings that indicate potential, positive association, or actual incidence of water contamination; and 87% of air quality studies contain findings that indicate elevated air pollutant emissions and/or atmospheric concentrations. This paper demonstrates that the weight of the findings in the scientific literature indicates hazards and elevated risks to human health as well as possible adverse health outcomes associated with UNGD. There are limitations to this type of assessment and it is only intended to provide a snapshot of the scientific knowledge based on the available literature. However, this work can be used to identify themes that lie in or across studies, to prioritize future research, and to provide an empirical foundation for policy decisions. PMID:27096432

  3. Impact of gas-phase mechanisms on Weather Research Forecasting Model with Chemistry (WRF/Chem) predictions: Mechanism implementation and comparative evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Chen, Yaosheng; Sarwar, Golam; Schere, Kenneth

    2012-01-01

    cloud condensation nuclei (CCN) and cloud droplet number concentration (CDNC) due to the feedback mechanisms among H2SO4 vapor, PM2.5 number, CCN, and CDNC through gas-phase chemistry, new particle formation via homogeneous nucleation, aerosol growth, and aerosol activation by cloud droplets. This study illustrates the important impact of gas-phase mechanisms on chemical and aerosol predictions, their subsequent effects on meteorological predictions, and a need for an accurate representation of such feedbacks through various atmospheric processes in the model. The online-coupled models that simulate feedbacks between meteorological variables and chemical species may provide more accurate representations of the real atmosphere for regulatory applications and can be applied to simulate chemistry-climate feedbacks over a longer period of time.

  4. Assessment of Emerging Regional Air Quality (AQ) and Greenhouse Gas (GHG) Impacts and Potential Mitigation Strategies in U.S. Energy Sectors

    NASA Astrophysics Data System (ADS)

    Kinnon, Michael Mac

    The current domestic reliance on high-emitting fossil fuels for energy needs is the key driver of U.S. greenhouse gas (GHG) and pollutant emissions driving both climate change and regional air quality (AQ) concerns. Moving forward, emission sources in U.S. energy sectors will be subjected to changes driven by numerous phenomena, including technology evolution, environmental impacts, sustainability goals, and socioeconomic factors. This evolution will directly affect emissions source-related impacts on regional AQ that effective emissions control strategies must account for, including relative source contributions. Though previous studies have evaluated the emissions and AQ impacts of different sectors, technologies and fuels, most previous studies have assessed emissions impacts only without using advanced atmospheric models to accurately account for both spatial and temporal emissions perturbations and atmospheric chemistry and transport. In addition, few previous studies have considered the integration of multiple technologies and fuels in different U.S. regions.. Finally, most studies do not project emissions several decades into the future to assess what sources should be targeted with priority over time. These aspects are critical for understanding how both emissions sources and potential mitigation strategies impact the formation and fate of primary and secondary pollutants, including ground-level ozone and particulate matter concentrations. Therefore, this work utilizes a set of modeling tools to project and then to spatially and temporally resolve emissions as input into a 3-D Eulerian AQ model to assess how sources of emissions contribute to future atmospheric pollutant burdens. Further, analyses of the potential impacts of alternative energy strategies contained in potential mitigation strategies are conducted for priority targets to develop an understanding of how to maximize AQ benefits and avoid unforeseen deleterious tradeoffs between GHG reduction

  5. Differential impact of immediate total deregulation of wellhead prices of natural gas on minority and low-income homeowners: a general review and a case study in the Washington, DC area

    SciTech Connect

    Green, R.D.; Gilbert, H.R.

    1983-01-01

    In this study, the authors evaluate the impact of total deregulation of wellhead prices of natural gas on various strata of the residential consuming population, and compare it to the baseline impact of a continuation of the Natural Gas Policy Act of 1978. They found that minority and poverty homeowners will suffer greater relative welfare losses than their white and non-poverty counterparts. They developed quantitative estimates of the extent of these differentials, and offered some policy proposals suggested by these findings. 54 refs., 8 figs., 68 tabs.

  6. Mechanism of charge transfer and its impacts on Fermi-level pinning for gas molecules adsorbed on monolayer WS{sub 2}

    SciTech Connect

    Zhou, Changjie; Zhu, Huili; Yang, Weihuang

    2015-06-07

    Density functional theory calculations were performed to assess changes in the geometric and electronic structures of monolayer WS{sub 2} upon adsorption of various gas molecules (H{sub 2}, O{sub 2}, H{sub 2}O, NH{sub 3}, NO, NO{sub 2}, and CO). The most stable configuration of the adsorbed molecules, the adsorption energy, and the degree of charge transfer between adsorbate and substrate were determined. All evaluated molecules were physisorbed on monolayer WS{sub 2} with a low degree of charge transfer and accept charge from the monolayer, except for NH{sub 3}, which is a charge donor. Band structure calculations showed that the valence and conduction bands of monolayer WS{sub 2} are not significantly altered upon adsorption of H{sub 2}, H{sub 2}O, NH{sub 3}, and CO, whereas the lowest unoccupied molecular orbitals of O{sub 2}, NO, and NO{sub 2} are pinned around the Fermi-level when these molecules are adsorbed on monolayer WS{sub 2}. The phenomenon of Fermi-level pinning was discussed in light of the traditional and orbital mixing charge transfer theories. The impacts of the charge transfer mechanism on Fermi-level pinning were confirmed for the gas molecules adsorbed on monolayer WS{sub 2}. The proposed mechanism governing Fermi-level pinning is applicable to the systems of adsorbates on recently developed two-dimensional materials, such as graphene and transition metal dichalcogenides.

  7. Compression of a fast MHD jet upon impact with a heavy gas cloud: an analog to liner compression

    NASA Astrophysics Data System (ADS)

    Greig, Amelia; Bellan, Paul

    2015-11-01

    The Caltech plasma jet experiment was previously configured to have a fast MHD-driven hydrogen plasma jet collide with a neutral argon cloud located in the path of the jet. By changing to the jet frame, this compression of the light hydrogen jet by impact with the heavy cloud is seen to be equivalent to the Magnetized Inertial Fusion situation of a heavy liner compressing a low-density, magnetized plasma. In the previous experiments it was observed that the hydrogen jet quickly ionized the heavy argon cloud and, being relative low mass compared to the cloud, the hydrogen jet became scrunched up by the impact. Magnetic probe measurements indicated that this nearly tripled the jet magnetic field while Stark broadening showed a simultaneous substantial density increase. We will repeat these measurements for a greater range of parameters and with better diagnostics with the ultimate goal of determining an equation of state characterizing the actual observed behavior. Preliminary results will be presented. Supported by ARPA-E ALPHA program.

  8. Sea-level rise and impacts projections under a future scenario with large greenhouse gas emission reductions

    NASA Astrophysics Data System (ADS)

    Pardaens, A. K.; Lowe, J. A.; Brown, S.; Nicholls, R. J.; de Gusmão, D.

    2011-06-01

    Using projections from two coupled climate models (HadCM3C and HadGEM2-AO), we consider the effect on 21st century sea-level rise (SLR) of mitigation policies relative to a scenario of business-as-usual (BAU). Around a third of the global-mean SLR over the century is avoided by a mitigation scenario under which global-mean near surface air temperature stabilises close to the Copenhagen Accord limit of a 2°C increase. Under BAU (a variant of the A1B scenario) the model-averaged projected SLR for 2090-2099 relative to 1980-1999 is 0.29 m-0.51 m (5%-95% uncertainties from treatment of land-based ice melt); under mitigation (E1 scenario) it is 0.17 m-0.34 m. This reduction is primarily from reduced thermal expansion. The spatial patterns of regional SLR are fairly dissimilar between the models, but are qualitatively similar across scenarios for a particular model. An impacts model suggests that by the end of the 21st century and without upgrade in defences around 55% of the 84 million additional people flooded per year globally under BAU (from SLR alone) could be avoided under such mitigation. The above projections of SLR follow the methodology of the IPCC Fourth Assessment. We have, however, also conducted a sensitivity study of SLR and its impacts where the possibility of accelerated ice sheet dynamics is accounted for.

  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.

    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

  10. Impact of intermittent aerations on leachate quality and greenhouse gas reduction in the aerobic-anaerobic landfill method.

    PubMed

    Nag, Mitali; Shimaoka, Takayuki; Komiya, Teppei

    2016-09-01

    The aerobic-anaerobic landfill method (AALM) is a novel approach in solid waste management that could shorten the landfill post-closure period and minimize the environmental loads. In this study, the aerobic-anaerobic landfill method was evaluated by using intermittent aeration. In addition, the nitrification-denitrification process was assessed as a means of reducing the emission of greenhouse gases (GHGs) and improving the leachate quality during the degradation of the organic solid waste. The leachate quality and the gas composition in each of the reactors were measured during the experimental period (408days). The aeration process entailed the injection of air into plexiglass cylinders (200cm height×10 cm diameter), filled with fresh organic solid waste collected from a composting plant. Different aeration routines were applied, namely, continuous aeration (aerobic reactor A), aeration for three days/week (aerobic-anaerobic reactor B), aeration for 6h/day (aerobic-anaerobic reactor C), and no aeration (non-aerated reactor D). It was found that aerobic reactor A produced the best results in terms of reduction of GHGs and improvement of the leachate quality. The aerobic-anaerobic reactor C was found to be more effective than reactor B in respect of both the emission of GHGs and the leachate quality; moreover, compared with aerobic reactor A, energy costs were reduced by operating this reactor. The transition period phenomenon was investigated during an intensive seven-day experiment conducted on the discharged leachate obtained from aerobic-anaerobic reactors B and C. The experiment concerned the differences in the composition of the gas during the aeration and the non-aeration periods. It was found that the transition period between the aeration and non-aeration cycles, which followed the simultaneous nitrification-denitrification had a considerable effect on the leachate quality of both the reactors. The results indicated that AALM has the potential to reduce

  11. Explicit Finite Element Modeling of Multilayer Composite Fabric for Gas Turbine Engine Containment Systems, Phase II. Part 2; Ballistic Impact Testing

    NASA Technical Reports Server (NTRS)

    Revilock, D. M.; Pereira, J. M.

    2009-01-01

    This report summarizes the ballistic impact testing that was conducted to provide validation data for the development of numerical models of blade-out events in fabric containment systems. The ballistic impact response of two different fiber materials - Kevlar(TradeName) 49 and Zylon(TradeName) AS (as spun) was studied by firing metal projectiles into dry woven fabric specimens using a gas gun. The shape, mass, orientation, and velocity of the projectile were varied and recorded. In most cases, the tests were designed so the projectile would perforate the specimen, allowing measurement of the energy absorbed by the fabric. The results for both Zylon and Kevlar presented here represent a useful set of data for the purposes of establishing and validating numerical models to predict the response of fabrics under conditions that simulate those of a jet engine blade-release situation. In addition, some useful empirical observations were made regarding the effects of projectile orientation and the relative performance of the different fabric materials.

  12. A Model Study of the Impact of Source Gas Changes on the Stratosphere for 1850-2100

    NASA Technical Reports Server (NTRS)

    Fleming, E. L.; Jackman, C. H.; Stolarski, R. S.; Douglass, A. R.

    2011-01-01

    The long term stratospheric impacts due to emissions of CO2, CH4, N2O, and ozone depleting substances (ODSs) are investigated using an updated version of the Goddard two-dimensional (2D) model. Perturbation simulations with the ODSs, CO2, CH4, and N2O varied individually are performed to isolate the relative roles of these gases in driving stratospheric changes over the 1850-2100 time period. We also show comparisons with observations and the God- 40 dard Earth Observing System chemistry-climate model simulations for the time period 1970-2100 to illustrate that the 2D model captures the basic processes responsible for longterm stratospheric change. The 2D simulations indicate that prior to 1940, the 45 ozone increases due to CO2 and CH4 loading outpace the ozone losses due to increasing N2O and carbon tetrachloride (CCl4) emissions, so that ozone reaches a broad maximum during the 1920s-1930s. This preceeds the significant ozone depletion during approx. 1960-2050 driven by the ODS loading. During the latter half of the 21st century as ODS emissions diminish, CO2, N2O, and CH4 loading will all have significant impacts on global total ozone based on the IPCC AIB (medium) scenario, with CO2 having the largest individual effect. Sensitivity tests illustrate that due to the strong chemical interaction between methane and chlorine, the CH4 impact on total ozone becomes significantly more positive with larger ODS loading. The model simulations also show that changes in stratospheric temperature, Brewer-Dobson circulation (BDC), and age of air during 1850-2100 are controlled mainly by the CO2 and ODS loading. The simulated acceleration of the BDC causes the age of air to decrease by approx. 1 year from 1860-2100. The corresponding photochemical lifetimes of N2O, CFCl3, CF2Cl2, and CCl4 decrease by 11-13% during 1960-2100 due to the acceleration of the BDC, with much smaller lifetime changes 4%) caused by changes in the photochemical loss rates.

  13. Polystyrene as a model system to probe the impact of ambient gas chemistry on polymer surface modifications using remote atmospheric pressure plasma under well-controlled conditions.

    PubMed

    Bartis, Elliot A J; Luan, Pingshan; Knoll, Andrew J; Hart, Connor; Seog, Joonil; Oehrlein, Gottlieb S

    2015-01-01

    An atmospheric pressure plasma jet (APPJ) was used to treat polystyrene (PS) films under remote conditions where neither the plume nor visible afterglow interacts with the film surface. Carefully controlled conditions were achieved by mounting the APPJ inside a vacuum chamber interfaced to a UHV surface analysis system. PS was chosen as a model system as it contains neither oxygen nor nitrogen, has been extensively studied, and provides insight into how the aromatic structures widespread in biological systems are modified by atmospheric plasma. These remote treatments cause negligible etching and surface roughening, which is promising for treatment of sensitive materials. The surface chemistry was measured by X-ray photoelectron spectroscopy to evaluate how ambient chemistry, feed gas chemistry, and plasma-ambient interaction impact the formation of specific moieties. A variety of oxidized carbon species and low concentrations of NOx species were measured after APPJ treatment. In the remote conditions used in this work, modifications are not attributed to short-lived species, e.g., O atoms. It was found that O3 does not correlate with modifications, suggesting that other long-lived species such as singlet delta oxygen or NOx are important. Indeed, surface-bound NO3 was observed after treatment, which must originate from gas phase NOx as neither N nor O are found in the pristine film. By varying the ambient and feed gas chemistry to produce O-rich and O-poor conditions, a possible correlation between the oxygen and nitrogen composition was established. When oxygen is present in the feed gas or ambient, high levels of oxidation with low concentrations of NO3 on the surface were observed. For O-poor conditions, NO and NO2 were measured, suggesting that these species contribute to the oxidation process, but are easily oxidized when oxygen is present. That is, surface oxidation limits and competes with surface nitridation. Overall, surface oxidation takes place easily

  14. Impact of oxidation catalysts on exhaust NO2/NOx ratio from lean-burn natural gas engines.

    PubMed

    Olsen, Daniel B; Kohls, Morgan; Arney, Gregg

    2010-07-01

    Oxides of nitrogen (NOx) emitted from internal combustion engines are composed primarily of nitric oxide (NO) and nitrogen dioxide (NO2). Exhaust from most combustion sources contains NOx composed primarily of NO. There are two important scenarios specific to lean-burn natural gas engines in which the NO2/NOx ratio can be significant: (1) when the engine is operated at ultralean conditions and (2) when an oxidation catalyst is used. Large NO2/NOx ratios may result in additional uncertainty in NOx emissions measurements because the most common technique (chemiluminescence) was developed for low NO2/NOx ratios. In this work, scenarios are explored in which the NO2/NOx ratio can be large. Additionally, three NOx measurement approaches are compared for exhaust with various NO2/NOx ratios. The three measurement approaches are chemiluminescence, chemical cell, and Fourier-transform infrared spectroscopy. A portable analyzer with chemical cell technology was found to be the most accurate for measuring exhaust NOx with large NO2/NOx ratios. PMID:20681434

  15. The impact of deep overshooting convection on the water vapour and trace gas distribution in the TTL and lower stratosphere

    NASA Astrophysics Data System (ADS)

    Frey, W.; Schofield, R.; Hoor, P. M.; Ravegnani, F.; Ulanovsky, A.; Viciani, S.; D'Amato, F.; Lane, T. P.

    2014-12-01

    Overshooting convection penetrating the tropical tropopause layer (TTL) and the lower stratosphere has a significant impact on the redistribution of water vapour and further trace gases. This is of importance for the stratospheric water vapour budget, which plays a central role in radiative and chemical processes. Modelling studies and in situ measurements show the hydration potential of convective overshooting partly by direct injection of ice particles into the stratosphere and subsequent sublimation. However, processes leading to dehydration of the TTL may also impact the stratospheric humidity by limiting the amount of water vapour carried aloft. While the large scale drives some of the dehydrating processes, others are of convective origin, for example gravity waves and cooling associated with overshooting turrets. Furthermore, downdrafts may transport dry and ozone rich air masses from the stratosphere into the TTL. Improving our understanding of overshooting convection and its influence on TTL water vapour will ultimately place better constraints on the budget of water vapour in the stratosphere.In this study we use three-dimensional cloud resolving (WRF-ARW) simulations of a deep convective thunderstorm (Hector) to study the redistribution of water vapour and trace gases in the upper TTL/lower stratosphere. Passive tracers are initialised to investigate the transport of air masses. The simulations focus on an Hector event that has been probed by aircraft during the SCOUT-O3 field campaign. Observations were performed in and around overshoots that even penetrated the stratosphere. These observations as well as the model simulations show downward transport and mixing of air masses from the stratosphere, though less strong and more localised in the simulation. Furthermore, the simulations shows a layering of hydrated and dehydrated air masses post-convection in the upper TTL and lower stratosphere. Here we use the model to explain the processes causing the

  16. MODELING THE IMPACT OF ELEVATED MERCURY IN DEFENSE WASTE PROCESSING FACILITY MELTER FEED ON THE MELTER OFF-GAS SYSTEM - PRELIMINARY REPORT

    SciTech Connect

    Zamecnik, J.; Choi, A.

    2009-03-25

    The Defense Waste Processing Facility (DWPF) is currently evaluating an alternative Chemical Process Cell (CPC) flowsheet to increase throughput. It includes removal of the steam-stripping step, which would significantly reduce the CPC processing time and lessen the sampling needs. However, its downside would be to send 100% of the mercury that come in with the sludge straight to the melter. For example, the new mercury content in the Sludge Batch 5 (SB5) melter feed is projected to be 25 times higher than that in the SB4 with nominal steam stripping of mercury. This task was initiated to study the impact of the worst-case scenario of zero-mercury-removal in the CPC on the DWPF melter off-gas system. It is stressed that this study is intended to be scoping in nature, so the results presented in this report are preliminary. In order to study the impact of elevated mercury levels in the feed, it is necessary to be able to predict how mercury would speciate in the melter exhaust under varying melter operating conditions. A homogeneous gas-phase oxidation model of mercury by chloride was developed to do just that. The model contains two critical parameters pertaining to the partitioning of chloride among HCl, Cl, Cl{sub 2}, and chloride salts in the melter vapor space. The values for these parameters were determined at two different melter vapor space temperatures by matching the calculated molar ratio of HgCl (or Hg{sub 2}Cl{sub 2}) to HgCl{sub 2} with those measured during the Experimental-Scale Ceramic Melter (ESCM) tests run at the Pacific Northwest National Laboratory (PNNL). The calibrated model was then applied to the SB5 simulant used in the earlier flowsheet study with an assumed mercury stripping efficiency of zero; the molar ratio of Cl-to-Hg in the resulting melter feed was only 0.4, compared to 12 for the ESCM feeds. The results of the model run at the indicated melter vapor space temperature of 650 C (TI4085D) showed that due to excessive shortage of

  17. Soil Incubation Study to Assess the Impacts of Manure Application and Climate Change on Greenhouse Gas Emissions from Agricultural Soil

    NASA Astrophysics Data System (ADS)

    Schiavone, K.; Barbieri, L.; Adair, C.

    2015-12-01

    Agricultural fields in Vermont's Lake Champlain Basin have problems with the loss of nutrients due to runoff which creates eutrophic conditions in the lakes, ponds and rivers. In efforts to retain nitrogen and other nutrients in the soil farmers have started to inject manure rather than spraying it. Our understanding of the effects this might have on the volatilization of nitrogen into nitrous oxide is limited. Already, agriculture produces 69% of the total nitrous oxide emissions in the US. Understanding that climate change will affect the future of agriculture in Vermont, we set up a soil core incubation test to monitor the emissions of CO₂ and N₂O using a Photoacoustic Gas Sensor (PAS). Four 10 cm soil cores were taken from nine different fertilizer management plots in a No Till corn field; Three Injected plots, three Broadcast plots, and three Plow plots. Frozen soil cores were extracted in early April, and remained frozen before beginning the incubation experiment to most closely emulate three potential spring environmental conditions. The headspace was monitored over one week to get emission rates. This study shows that environmental and fertilizer treatments together do not have a direct correlation to the amount of CO₂ and N₂O emissions from agricultural soil. However, production of CO₂ was 26% more in warmer environmental conditions than in variable(freeze/thaw) environmental conditions. The injected fertilizer produced the most emissions, both CO₂ and N₂O. The total N₂O emissions from Injected soil cores were 2.2x more than from traditional broadcast manure cores. We believe this is likely due to the addition of rich organic matter under anaerobic soil conditions. Although, injected fertilizer is a better application method for reducing nutrient runoff, the global warming potential of N₂O is 298 times that of CO₂. With climate change imminent, assessing the harmful effects and benefits of injected fertilizer is a crucial next step in

  18. Evaluating Impacts of CO2 and CH4 Gas Intrusion into an Unconsolidated Aquifer: Fate of As and Cd

    SciTech Connect

    Lawter, Amanda R.; Qafoku, Nikolla; Shao, Hongbo; Bacon, Diana H.; Brown, Christopher F.

    2015-07-10

    Abstract The sequestration of carbon dioxide (CO2) in deep underground reservoirs has been identified as an important strategy to decrease atmospheric CO2 levels and mitigate global warming, but potential risks on overlying aquifers currently lack a complete evaluation. In addition to CO2, other gases such as methane (CH4) may be present in storage reservoirs. This paper explores for the first time the combined effect of leaking CO2 and CH4 gasses on the fate of major, minor and trace elements in an aquifer overlying a potential sequestration site. Emphasis is placed on the fate of arsenic (As) and cadmium (Cd) released from the sediments or present as soluble constituents in the leaking brine. Results from macroscopic batch and column experiments show that the presence of CH4 (at a concentration of 1 % in the mixture CO2/CH4) does not have a significant effect on solution pH or the concentrations of most major elements (such as Ca, Ba, and Mg). However, the concentrations of Mn, Mo, Si and Na are inconsistently affected by the presence of CH4 (i.e., in at least one sediment tested in this study). Cd is not released from the sediments and spiked Cd is mostly removed from the aqueous phase most likely via adsorption. The fate of sediment associated As [mainly sorbed arsenite or As(III) in minerals] and spiked As [i.e., As5+] is complex. Possible mechanisms that control the As behavior in this system are discussed in this paper. Results are significant for CO2 sequestration risk evaluation and site selection and demonstrate the importance of evaluating reservoir brine and gas stream composition during site selection to ensure the safest site is being chosen.

  19. Response of Soil Biogeochemistry to Freeze-thaw Cycles: Impacts on Greenhouse Gas Emission and Nutrient Fluxes

    NASA Astrophysics Data System (ADS)

    Rezanezhad, F.; Parsons, C. T.; Smeaton, C. M.; Van Cappellen, P.

    2014-12-01

    Freeze-thaw is an abiotic stress applied to soils and is a natural process at medium to high latitudes. Freezing and thawing processes influence not only the physical properties of soil, but also the metabolic activity of soil microorganisms. Fungi and bacteria play a crucial role in soil organic matter degradation and the production of greenhouse gases (GHG) such as CO2, CH4 and N2O. Production and consumption of these atmospheric trace gases are the result of biological processes such as photosynthesis, aerobic respiration (CO2), methanogenesis, methanotrophy (CH4), nitrification and denitrification (N2O). To enhance our understanding of the effects of freeze-thaw cycles on soil biogeochemical transformations and fluxes, a highly instrumented soil column experiment was designed to realistically simulate freeze-thaw dynamics under controlled conditions. Pore waters collected periodically from different depths of the column and solid-phase analyses on core material obtained at the initial and end of the experiment highlighted striking geochemical cycling. CO2, CH4 and N2O production at different depths within the column were quantified from dissolved gas concentrations in pore water. Subsequent emissions from the soil surface were determined by direct measurement in the head space. Pulsed CO2 emission to the headspace was observed at the onset of thawing, however, the magnitude of the pulse decreased with each subsequent freeze-thaw cycle indicating depletion of a "freeze-thaw accessible" carbon pool. Pulsed CO2