Note: This page contains sample records for the topic gas chromatography-electron impact from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Determination of thiazolidine-4-carboxylates in urine by chloroformate derivatization and gas chromatography-electron impact mass spectrometry.  

PubMed

The derivatization method of thiazolidine-4-carboxylic acid (TZCA) and methyl-thiazolidine-4-carboxylic acid (Me-TZCA) in urine with alcohol/chloroformate was achieved. TZCA and Me-TZCA were derivatized in one step in urine with ethyl chloroformate in 1 min at room temperature. The derivatives of TZCA and Me-TZCA had very good chromatographic properties and offered very sensitive response for gas chromatography-electron impact ionization-mass spectrometry (GC-EI-MS). On the basis of derivatization, the method for simultaneous determination of TZCA and Me-TZCA in human urine was developed. Deuterated Me-TZCA (Me-TZCA-d(4)) was synthesized as the internal standard (IS) for the analysis of urine samples. TZCA and Me-TZCA were derivatized and extracted from urine at pH 9.5 with toluene, and then the dried extract was dissolved with 100 microl ethyl acetate and injected in GC/MS system. The recoveries of TZCA and Me-TZCA were about 102 and 103%, respectively, at the concentration of 0.05 mg/l. The method detection limits (MDL) were 1.0 and 0.5 microg/l, respectively, for TZCA and Me-TZCA in 1 ml human urine. The coefficients of variation of TZCA and Me-TZCA were less than 6% at the concentrations of 0.05 and 0.2 mg/l, respectively. To assess the formation of TZCA during inhalation with formaldehyde (FA) (about 3.1 and 38.1 ppm FA in air), urine samples from rats were taken during 3 days after initiation of treatment. The mean amount of TZCA determined was 0.07 mg/l in control group and 0.18 mg/l during treatment with 3.1 ppm. The TZCA levels increased up to about 1.01 mg/l during treatment with 38.1 ppm. It is planned to study whether urinary TZCA can be used as an indicator in the biological monitoring of exposure to FA. PMID:17610311

Shin, Ho-Sang; Ahn, Hye-Sil; Lee, Byung-Hoon

2007-09-01

2

Determination of Acrylamide in Rat Serum and Sciatic Nerve by Gas Chromatography-Electron-Capture Detection.  

National Technical Information Service (NTIS)

A modified method for the derivatization and determination of acrylamide as 2-bromopropenamide by gas chromatography-electron-capture detection was developed and applied to serum and sciatic nerve from rats. The method was accurate and precise over the ca...

J. H. Raymer C. M. Sparacino G. R. Velez S. Padilla R. C. MacPhail

1993-01-01

3

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...

4

Profiling Neurosteroids in Cerebrospinal Fluids and Plasma by Gas Chromatography\\/Electron Capture Negative Chemical Ionization Mass Spectrometry  

Microsoft Academic Search

A quantitative method for the determination of allopregnanolone (5?,3?-THP) and related neurosteroids in CSF and plasma was established using gas chromatography\\/electron capture negative chemical ionization mass spectrometry (GC\\/ECNCI\\/MS). Neurosteroids were converted to carboxymethoxime, pentafluorobenzyl and trimethylsilyl derivatives and detected as intense (M-181)? fragment ions generated under the negative ion chemical ionization process. The response curves constructed using d4-dihydrotestosterone (DHT) and

Yang-Suk Kim; Hongjian Zhang; Hee-Yong Kim

2000-01-01

5

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

PubMed

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

Begley, P; Foulger, B E

1988-04-01

6

Study of the fragmentation pattern of ketamine-heptafluorobutyramide by gas chromatography/electron ionization mass spectrometry.  

PubMed

Ketamine is an anaesthetic compound used in human and veterinary medicine with hallucinogen properties that have resulted in its increased illicit use by teenagers at rave parties. Although several gas chromatography/mass spectrometry (GC/MS) methods have been reported for the quantification of the drug both in urine and in hair, its electron ionization (EI) fragmentation after derivatization with different reagents has been not yet fully investigated. The present work reports the study of the fragmentation of ketamine, derivatized with heptafluorobutyric anhydride (HFBA-Ket), using gas chromatography/electron ionization mass spectrometry (GC/EI-MS). The complete characterization of the fragmentation pattern represented an intriguing exercise and required tandem mass spectrometry (MS(n)) experiments, high-resolution accurate mass measurements and the use of deuterated d(4)-ketamine to corroborate the proposed structures and to characterize the fragment ions carrying the unchanged aromatic moiety. Extensive fragmentation was observed, mainly located at the cyclohexanone ring followed by rearrangement of the fragment ions, as confirmed by the mass spectra obtained from the deuterated molecule. The GC/EI-MS analysis of HFBA-Ket will represent a useful tool in forensic science since high-throughput analyses are enabled, preserving both the GC stationary phase and the cleanliness of the mass spectrometer ion optics. PMID:19957293

Pieri, Maria; Castiglia, Loredana; Miraglia, Nadia; Guadagni, Rossella; Malorni, Livia; Sannolo, Nicola; Acampora, Antonio; Della Casa, Elvira

2010-01-01

7

Determination of indicator polychlorinated biphenyls (PCBs) by gas chromatography-electron capture detector.  

PubMed

An effective method for determination of indicator polychlorinated biphenyls (PCBs) has been validated using gas chromatography (GC) equipped with electron capture detector (ECD). The GC-ECD method was validated by determining the linear range (working range) for determination of the compounds, minimum detectable quantities (MDQ), the precision and accuracy of the method for the analysis of the compounds. MDQ obtained for the compounds ranges from 0.0005 to 0.002 ng. Indeed the method was found to be more sensitive as the number of chlorine atoms attached to the biphenyl increases. The precision and accuracy of the GC method validated ranges from 2.4% to 14.5% and -7.0% to 14.6% respectively. Coefficient of variation associated with the repeatability of the retention times and corresponding peak areas was found to be 0.0001-0.0007 for the retention times and 0.0014-0.059 for the peak areas. Percentage recoveries for the compounds were in the range of 95.7-101.0%. The validated method was then applied to determine levels of indicator PCBs in sediments sampled from eleven sampling points along the Lake Bosuntwi in Ghana and the highest PCB load of 19.17 ng g(-1) was recorded at Pipie No. 2. PCB 52 and PCB 101 were found to be the most ubiquitous indicator PCBs in the study area, both with 90.91% occurrence. PMID:24016628

Afful, Samuel; Awudza, Johannes A M; Twumasi, Stevester K; Osae, Shiloh

2013-11-01

8

Photocatalytic oxidation of aqueous trichloroethylene using dye sensitized buoyant photocatalyst monitored via micro-headspace solid-phase microextration gas chromatography\\/electron capture detection and mass spectrometry  

Microsoft Academic Search

Trichloroethylene (TCE), a useful industrial agent which unfortunately exhibits carcinogenic properties, has become an extremely prevalent environmental contaminant. As such, new rapid, sensitive, and cost effective detection methods are needed for the identification of potential point sources of contamination. A new analytic micro-headspace method is described, utilizing solid phase micro-extraction (SPME) fibers and routine gas chromatography\\/electron capture detection (GC\\/ECD) for

Matt V. Alexander; Jeffrey J. Rosentreter

2008-01-01

9

Determination of chlorophenols in water samples using simultaneous dispersive liquid–liquid microextraction and derivatization followed by gas chromatography-electron-capture detection  

Microsoft Academic Search

Simultaneous dispersive liquid–liquid microextraction (DLLME) and derivatization combined with gas chromatography-electron-capture detection (GC-ECD) was used to determine chlorophenols (CPs) in water sample. In this derivatization\\/extraction method, 500?L acetone (disperser solvent) containing 10.0?L chlorobenzene (extraction solvent) and 50?L acetic anhydride (derivatization reagent) was rapidly injected by syringe in 5.00mL aqueous sample containing CPs (analytes) and K2CO3 (0.5%, w\\/v). Within a few

Nazir Fattahi; Yaghoub Assadi; Mohammad Reza Milani Hosseini; Elham Zeini Jahromi

2007-01-01

10

Determination of pentachlorophenol residue in meat and fish by gas chromatography-electron capture detection and gas chromatography-mass spectrometry with accelerated solvent extraction.  

PubMed

A novel analytical method, using gas chromatography-electron capture detection (GC-ECD) and GC-mass spectrometry detection (MS), was developed for the qualitative and quantitative measurement of pentachlorophenol in meat and fish. The analyte was extracted by methanol-2% trichloroacetic acid (3/1, v/v) with accelerated solvent extraction (ASE). The eluted fraction was evaporated and derivatized with acetic anhydride-pyridine (1/1, v/v) for GC-ECD analysis and GC-MS confirmation. The parameters for extraction pressure, temperature and cycle of ASE, cleanup, derivatization and analysis procedure were optimized. The averaged decision limits and detection capability of the method were in the ranges of 0.25-0.41 and 0.49-1.01 µg/kg in the muscle and liver of swine and bovine and in the muscle of carp and finless eel, respectively. Spiked recoveries from levels of 0.5-2.0 µg/kg were found to be more than 71.1%, with relative standard deviation less than 14.7% in GC-ECD and GC-MS. This rapid and reliable method can be used for the characterization and quantification of residues of pentachlorophenol in animal and fish tissues. PMID:23690067

Zhao, Dongmei

2014-05-01

11

Analysis of N-nitrosamines in water by isotope dilution gas chromatography-electron ionisation tandem mass spectrometry.  

PubMed

A method has been developed for the determination of eight N-nitrosamines in drinking water and treated municipal effluent. The method uses solid phase extraction (SPE), gas chromatography (GC) and analysis by tandem mass spectrometry (MS-MS) with electron ionization (EI). The target compounds are N-nitrosodimethylamine (NDMA), N-nitrosomethyethylamine (NMEA), N-nitrosodiethylamine NDEA), N-nitrosodipropylamine (NDPA), N-nitrosodi-n-butylamine (NDBuA), N-nitrosodiphenylamine (NDPhA), N-nitrosopyrrolidine (NPyr), N-nitrosopiperidine (NPip), N-nitrosomorpholine (NMorph). The use of direct isotope analogues for isotope dilution analysis of all analytes ensures accurate quantification, accounting for analytical variabilities that may occur during sample processing, extraction and instrumental analysis. Method detection levels (MDLs) were determined to describe analyte concentrations sufficient to provide a signal with 99% certainty of detection. The established MDLs for all analytes were 0.4-4 ng L(-1) in a variety of aqueous matrices. Sample matrices were observed to have only a minor impact on MDLs and the method validation confirmed satisfactory method stability over intra-day and inter-day analyses of tap water and tertiary treated effluent samples. PMID:22967534

McDonald, James A; Harden, Nick B; Nghiem, Long D; Khan, Stuart J

2012-09-15

12

Improved method for the in vitro assessment of antioxidant activity of plant extracts by headspace solid-phase microextraction and gas chromatography-electron capture detection.  

PubMed

The simultaneous monitoring of malondialdehyde, pentanal and hexanal, final products of lipid peroxidation is reported, using a headspace solid-phase microextraction (HS-SPME) technique with on-fibre derivatisation. The aldehydes are extracted and subjected to on-sorbent derivatisation into stable hydrazones with 2,4,6-trichlorophenylhydrazine (TCPH) and analyzed. The degree of inhibition of oxidation is performed by monitoring the chlorinated hydrazones after thermal desorption, by gas chromatography-electron capture detection. The procedure was employed to evaluate in vitro the antioxidant activity of Hypericum perforatum L. extracts and of the well-known antioxidant vitamin E following induction of oxidation of sunflower oil, as a model lipid system. Prior to the measurement of antioxidant activity, the optimal process conditions, i.e. headspace volume, temperature, agitation, extraction/derivatisation time and desorption time and temperature were properly established. Aqueous extracts of H. perforatum L. exhibited the highest antioxidative effect. The method is shown to be promising for screening purposes for antioxidant substances and natural extracts. PMID:17316667

Gioti, Eleni M; Fiamegos, Yiannis C; Skalkos, Dimitris C; Stalikas, Constantine D

2007-06-01

13

An Examination of Pentafluorobenzoyl Derivatization Strategies for the Analysis of Fatty Alcohols using Gas Chromatography/Electron Capture Negative Ion Chemical Ionization-Mass Spectrometry  

PubMed Central

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 byproducts 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 was 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.

Bowden, John A.; Ford, David A.

2010-01-01

14

Solid phase extraction with silicon dioxide microsphere adsorbents in combination with gas chromatography-electron capture detection for the determination of DDT and its metabolites in water samples.  

PubMed

The goal of the present study was to investigate the feasibility of silicon dioxide (SiO(2)) microspheres without special modification to enrich dichlorodiphenyltrichloroethane (DDT) and its main metabolites, p,p'-dichlorodiphenyl-2,2-dichloroethylene (p,p'-DDD) and p,p'-dichlorodiphenyldichloroethylene (DDE) in combination with gas chromatography-electron-capture detection. The experimental results indicated that an excellent linear relationship between the recoveries and the concentrations of DDT and its main metabolites was obtained in the range of 0.2-30 ng mL(-1) and the correlation coefficients were in the range of 99.96-99.99%. The detection limits based on the ratio of signal to the baseline noise (S/N = 3) were 2.2, 2.9, 3.8 and 4.1 ng L(-1) for p,p'-DDD, p,p'-DDT, o,p'-DDT, and p,p'-DDE, respectively. The precisions of the proposed method were all below 10% (n = 6). Four real water samples were utilized for validation of the proposed method, and satisfactory spiked recoveries in the range of 72.4-112.9% were achieved. These results demonstrated that the developed method was a simple, sensitive, and robust analytical method for the monitoring of pollutants in the environment. PMID:23356340

Zhou, Qingxiang; Wu, Wei; Xie, Guohong

2013-01-01

15

Group-selective enrichment and determination of pyrethroid insecticides in aquaculture seawater via molecularly imprinted solid phase extraction coupled with gas chromatography-electron capture detection.  

PubMed

Two types of molecularly imprinted polymers (MIPs) for the simultaneous determination of six pyrethroid insecticides have been developed using deltamethrin (D-MIPs) and cypermethrin (C-MIPs) as template molecules. A comparison of the performance of D-MIPs, C-MIPs, and the corresponding non-imprinted polymers (NIPs) were conducted. Stronger group-selective interactions between the C-MIPs and the six pyrethroid insecticides were achieved. The MISPE method based on the C-MIPs displayed higher extraction recoveries (86.4-96.0%) with RSD values ranging from 2.4 to 7.8% for the six pyrethroid insecticides in aquaculture seawater. After the C-MIP cartridge procedure, the limits of detection and quantification for fenvalerate, deltamethrin, cypermethrin, cyfluthrin, and bifenthrin were in the 16.6-37.0 and 55.3-109.1 ng L?¹ ranges, respectively, and 0.68 and 2.26 ?g L?¹ for phenothrin, respectively. The proposed MISPE method coupled with gas chromatography-electron capture detection was successfully used for the determination of the six pyrethroid insecticides in aquaculture seawater. PMID:22265776

Shi, Xizhi; Liu, Jinghua; Sun, Aili; Li, Dexiang; Chen, Jiong

2012-03-01

16

Evaluation of BDE-47 Hydroxylation Metabolic Pathways Based on a Strong Electron-Withdrawing Pentafluorobenzoyl Derivatization Gas Chromatography/Electron Capture Negative Ionization Quadrupole Mass Spectrometry.  

PubMed

Understanding the metabolic pathways of polybrominated diphenyl ethers (PBDEs) is a key issue in the evaluation of their cytotoxicity after they enter the biota. In order to obtain more information concerning the metabolic pathways of PBDEs, we developed a strong electron-withdrawing pentafluorobenzoyl (PFBoyl) derivatization capillary gas chromatography/electron capture negative ionization quadrupole mass spectrometry (GC/ECNI-qMS). PFBoyl esterification greatly improves separation of the metabolites of PBDEs such as hydroxylated PBDEs (OH-PBDEs) and bromophenols (BPs) metabolites in rat liver microsomes (RLMs). On the other hand, the strong electron-withdrawing property of PFBoyl derivatized on OH-PBDEs and/or BPs makes cleavage of the ester bond on ECNI easier resulting in higher abundance of the structure-informative characteristic fragment ions at a high m/z region, which facilitate the identification of OH-PBDEs metabolites. Subsequent quantification can be performed by monitoring not only (79)Br(-) (or (81)Br(-)) but also their characteristic fragment ions, achieving more accurate isotope dilution quantification using GC/ECNI-qMS. These merits allow us to identify totally 12 metabolites of BDE-47, a typical example of PBDEs, in the RLMs in vitro incubation systems. In addition to the already known metabolites of BDE-47, one dihydroxylated 3,6-di-OH-BDE-47 and one dihydroxylated 3,5-di-OH-tetrabrominated dioxin were found. Moreover, the second hydroxylation took place on the same bromophenyl ring, where the first hydroxyl group was located, and was further confirmed via the identification of the dihydroxylated 2',6'-di-OH-BDE-28 of an asymmetric 2'-OH-BDE-28. This methodological development and its subsequent findings of the metabolic pathways of BDE-47 provided experimental evidence for understanding its dioxin-like behavior and endocrine disrupting risk. PMID:24925108

Zhai, Chao; Peng, Shunv; Yang, Limin; Wang, Qiuquan

2014-07-15

17

Gas chromatography-electron ionization-mass spectrometry analysis of O,O'- dialkyl methylphosphonites for verification analysis of the Chemical Weapons Convention.  

PubMed

Gas chromatography-mass spectrometry (GC-MS) analysis of O,O'-dialkyl methylphosphonites (DAMPs) was carried out with a view to developing a database and understanding the mechanism of fragmentation. DAMPs are included in the list of schedule 2B4 chemicals of the Chemical Weapons Convention. GC-MS analysis of DAMPs and their deuterated analogs revealed that their fragmentations were dominated by ?-cleavages, alkenyl radical loss and hydrogen rearrangements. Based on fragment ions of deuterated analogs and density functional theory calculations, the fragmentation routes were rationalized. PMID:21625030

Pardasani, Deepak; Tak, Vijay; Purohit, Ajay K; Kanaujia, Pankaj K; Dubey, Devendra K

2011-01-01

18

Direct and simultaneous determination of trace-level carbon tetrachloride, peroxyacetyl nitrate, and peroxypropionyl nitrate using gas chromatography-electron capture detection.  

PubMed

Gas chromatography equipped with electron capture detector (GC-ECD) has been widely used for detecting atmospheric peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN). However, to the best of our knowledge, only a few capillary columns have been adopted for separation to achieve the direct and simultaneous analysis of the two atmospheric pollutants. This paper demonstrates a novel method for directly and simultaneously measuring atmospheric carbon tetrachloride (CCl(4)), PAN, and PPN using GC-ECD with a DB-1 separation column. The responses of the GC-ECD to PAN, PPN, and CCl(4) were individually calibrated by using gas mixtures prepared via volatilization of synthesized solutions of PAN and PPN or high-purity CCl(4) reagent in a Teflon Bag. The concentrations of PAN and PPN in the synthesized solutions were quantified by ion chromatography (IC). Further calibration of the GC-ECD for PAN was conducted by in situ photochemical formation of gaseous PAN which was quantified by a NO(x) analyzer. The two calibration methods agreed well with each other, and the overall uncertainties for measuring atmospheric PAN were estimated to be ± 13% and ± 15% based on the calibrations of IC and NO(x), respectively. The detection limits (three times the signal to noise ratio) for PAN, PPN, and CCl(4) were estimated to be 22, 36, and 5 pptv (parts per trillion by volume), respectively. The atmospheric concentrations of these compounds were measured for several days in August in Beijing, and the values obtained in this study were found to be in good agreement with the data reported in the literature for Beijing using other GC-ECD methods. PMID:23107119

Zhang, Gen; Mu, Yujing; Liu, Junfeng; Mellouki, Abdelwahid

2012-11-30

19

Extraction of ultra traces of polychlorinated biphenyls in aqueous samples using suspended liquid-phase microextraction and gas chromatography-electron capture detection.  

PubMed

This study reports the feasibility of applying directly suspended liquid-phase microextraction (DSLPME)-gas chromatography detection for the pre-concentration and determination of low levels of eight polychlorinated biphenyls (PCBs) in aqueous samples. The technique requires minimal sample preparation, analysis time and solvent consumption and represents significant advantages over conventional analytical methods. The experimental parameters such as salt content, sample temperature, stirring rate, extraction time, micro-drop volume and breakthrough volume were investigated and found to have significant influences on DSLPME. Under the optimal experimental conditions, the enrichment factor ranged from 578 to 729, and the recovery was above 93 %. Calibration curves possessed good linearity (R(2) > 0.99) over a wide concentration range of 0.1-10.0 ?g L(-1) with limits of detection ranging from 0.01 to 0.07 ?g L(-1). The relative standard deviations for 1.0 ?g L(-1) of PCBs in water by using internal standard were in the range 2-14 % (n = 3). The proposed simple, accurate and sensitive analytical method was applied successfully to the determination of trace amounts of PCBs in water samples. PMID:22892997

Hassan, Jalal; Shamsipur, Mojtaba

2013-05-01

20

Ultrasonic enhancement of leaching and in situ derivatization of haloacetic acids in vegetable foods prior to gas chromatography-electron capture detection.  

PubMed

A continuous ultrasound-assisted approach to enhance the extraction of nine haloacetic acids (HAAs) from vegetables with in situ derivatization to methyl esters for their gas chromatography (GC) analysis is presented. The optimization of simultaneous extraction (using acidic methanol as extractant) and derivatization enabled the completion of both steps in 15 min. Ultrasound assistance has proved to enhance both linked steps, which results in a considerable shortening of the overall analysis time (i.e. 552.1 and 552.2 EPA methods for analysis of these compounds in drinking water require 1 and 2 h, respectively, only for derivatization). After sample preparation, the esterified HAAs were isolated by liquid-liquid extraction with n-hexane and analysed by GC-electron capture detection. The proposed method is an interesting alternative to present methods for the determination of HAAs in vegetable foods. This is an area unjustifiably forgotten by reference laboratory organisms as proved by the absence of official methods for analysis of the target compounds in these samples. The proposed method can be applied to the analysis of HAAs in any solid sample after optimization of the main variables involved in the extraction-derivatization step. PMID:18586256

Alvarez Sánchez, B; Priego Capote, F; Luque de Castro, M D

2008-08-01

21

A rapid novel derivatization of amphetamine and methamphetamine using 2,2,2-trichloroethyl chloroformate for gas chromatography electron ionization and chemical ionization mass spectrometric analysis.  

PubMed

Amphetamine and methamphetamine are commonly abused central nervous system stimulants. We describe a rapid new derivatization of amphetamine and methamphetamine using 2,2,2-trichloroethyl chloroformate for gas chromatography-mass spectrometric analysis. Amphetamine and methamphetamine, along with N-propyl amphetamine (internal standard), were extracted from urine using 1-chlorobutane. The derivatization with 2,2,2-trichloroethyl chloroformate can be achieved at room temperature in 10 minutes. The electron ionization mass spectrum of amphetamine 2,2,2-trichloroethyl carbamate showed two weak molecular ions at m/z 309 and 311, but showed diagnostic strong peaks at m/z 218, 220, and 222. In contrast, chemical ionization of the mass spectrum of amphetamine 2,2,2-trichloroethyl carbamate showed strong (M + 1) ions at m/z 310 and 312 and other strong diagnostic peaks at m/z 274 and 276. The major advantages of this derivative are the presence of a diagnostic cluster of peaks due to the isotopic effect of three chlorine atoms (isotopes 35 and 37) in the derivatized molecule and the relative ease of its preparation. We also observed strong molecular ions for derivatized methamphetamine in the chemical ionization mass spectrum, but the molecular ions were very weak in the electron ionization mass spectrum. We used the scan mode of mass spectrometry in all analyses. When using a urine standard containing 1,000 ng/mL of amphetamine (a 7.4-micromol/L concentration) and methamphetamine (a 6.7-micromol/L concentration), the within-run precisions were 4.8% for amphetamine and 3.6% for methamphetamine. The corresponding between-run precisions were 5.3% for amphetamine and 6.7% for methamphetamine. The assay was linear for amphetamine and methamphetamine concentrations of 250 to 5,000 ng/mL (amphetamine, 1.9-37.0 micromol/L; methamphetamine, 1.7-33.6 micromol/L). The detection limit was 100 ng/mL (amphetamine, 0.74 micromol/L; methamphetamine, 0.67 micromol/L) using the scan mode of electron ionization mass spectrometry. We observed good a correlation between the concentrations of amphetamine and methamphetamine in five urine specimens positive for amphetamines using the more conventional pentafluoropropionyl derivative and our new derivative using 2,2,2-trichloroethyl chloroformate. PMID:9576569

Dasgupta, A; Spies, J

1998-05-01

22

Quantification of multi-residue levels in peach juices, pulps and peels using dispersive liquid-liquid microextraction based on floating organic droplet coupled with gas chromatography-electron capture detection.  

PubMed

In this paper, polychlorinated biphenyl (PCB), organochlorine pesticide (OCP) and pyrethroid pesticides in peach was investigated by comparing their residual level in peach juice, pulps and peels using dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) combined with gas chromatography-electron capture detection (GC-ECD). Extraction conditions such as the type of extractant, volume of extractant and dispersant, salt effect and extraction time were optimized. For juice samples, the linearity of the method was obtained in the range of 10-2000 ng L(-1),with determination coefficients>0.99. The limits of detection (LOD) of the method were ranged between 2.8 and 18.5 ng L(-1). For pulp and peel samples, the developed method is linear over the range assayed, 1-20 ?g kg(-1),with coefficients also >0.99. The relative recoveries of compounds analyzed from juice, pulp and peel samples were in the range of 73-106% with a relative standard deviation between 2.6 and 11.8%. The proposed method was applied to the simultaneous analysis of residues in real peach juice, pulp and peel samples. As a result, there were no target analytes found in peach juices and pulps while 3.3 ?g kg(-1) cyhalothrin and 3.5 ?g kg(-1) fenvalerate were found in peels. The experiment results revealed that the pyrethroid residues just deposited on the peels of the fruits, but did not move into pulps and juices. PMID:21703950

Matsadiq, Guzalnur; Hu, Hai-Li; Ren, Hai-Bo; Zhou, Yi-Wen; Liu, Lu; Cheng, Jing

2011-07-15

23

Confirmation of identity by gas chromatography/tandem mass spectrometry of sulfathiazole, sulfamethazine, sulfachloropyridazine, and sulfadimethoxine from bovine or swine liver extracts after quantitation by gas chromatography/electron-capture detection.  

PubMed

Four sulfonamide veterinary drug residues were quantitated by electron-capture detection (ECD) after separation by gas chromatography (GC). The identities of sulfathiazole (ST), sulfamethazine (SM), sulfachloropyridazine (SCP), and sulfadimethoxine (SDM) were confirmed in bovine or swine liver residues by tandem mass spectrometry (MS/MS). Bovine or swine liver tissues were extracted by using either the Tishler or the Manuel-Steller cleanup. The methylated residues containing ST, SM, SCP, and SDM were separated by GC prior to MS/MS daughter ion analysis. Control tissue, control tissue fortified at 0.1 ppm, and incurred tissue residues at approximately 0.1 ppm were analyzed for these 4 sulfonamides. A Finnigan Model TSQ-46 operating in the chemical ionization mode was used to perform the MS/MS daughter ion experiments. The identities of all 4 sulfonamides were confirmed in a single GC/MS/MS analysis. PMID:2211474

Matusik, J E; Sternal, R S; Barnes, C J; Sphon, J A

1990-01-01

24

Two-Dimensional Gas Chromatography\\/ Electron-Impact Mass Spectrometry with Cryofocusing for Simultaneous Quantification of MDMA, MDA, HMMA, HMA, and MDEA in Human Plasma  

Microsoft Academic Search

BACKGROUND: 3,4-Methylenedioxymethamphetamine (MDMA, or Ecstasy) is a popular recreational drug. Analysis of MDMA and metabolites in human plasma, particularly in pharmacokinetic studies, requires low limits of quantification. Two-dimensional GC\\/MS with cryofocusing is a chromatographic technique rec- ognized for its increased selectivity and resolution. METHODS: This method simultaneously quantifies 3,4- methylenedioxyethylamphetamine (MDEA), MDMA, and its metabolites, 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), and

Erin A. Kolbrich; Ross H. Lowe; Marilyn A. Huestis

25

Determination of isoprostaglandin F 2? type III in human urine by gas chromatography–electronic impact mass spectrometry. Comparison with enzyme immunoassay  

Microsoft Academic Search

F2-Isoprostanes are stable lipid peroxidation products of arachidonic acid, the quantification of which provides an index of oxidative stress in vivo. We describe a method for analysing isoprostaglandin F2? type III (15-F2t-IsoP) in biological fluids. The method involves solid-phase extraction on octadecyl endcapped and aminopropyl cartridges. After conversion to trimethylsilyl ester trimethylsilyl ether derivatives, isoprostaglandin F2? type III is analysed

Janine Bessard; Jean-Luc Cracowski; Françoise Stanke-Labesque; Germain Bessard

2001-01-01

26

Solar/Gas Systems Impact Analysis Study.  

National Technical Information Service (NTIS)

The impacts of solar/gas technologies on gas consumers and on gas utilities was measured separately and compared against the impacts of competing gas and electric systems in four climatic regions of the U.S. A methodology was developed for measuring the b...

E. F. Hahn B. Preble C. P. Neill J. C. Loose T. E. Poe

1984-01-01

27

NPS Gas Gun for Planar Impact Studies  

NASA Astrophysics Data System (ADS)

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.

Cheong Ho, Chien; Hixson, Robert

2009-11-01

28

The environmental impact of natural gas  

Microsoft Academic Search

This paper outlining the environmental impact of natural gas firstly describes the recent and increasing importance of gas in Western Europe, and its discovery in the North Sea. The effects resulting from its utilisation are also described. These include the effect on the implementation of the Clean Air Act and the changes brought about in land use pattern. In making

C. Hibberd

1977-01-01

29

Impacts of the European Gas Directive on Gas Exporters  

Microsoft Academic Search

The paper analyzes the EU Gas Directive and the new Norwegian statutory instruments for regulating natural gas transportation services. Such services are of great importance for gas sellers in their capacity as shippers in the system. The paper indicates that the regulation complies with economic theory on how to regulate a natural monopoly. Core elements are the establishment of an

Hans Jørgen Dahl; Sondre Dyrland; Thor Bjørkvoll

30

Impacts of gas drilling on human and animal health.  

PubMed

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

Bamberger, Michelle; Oswald, Robert E

2012-01-01

31

The greenhouse impact of unconventional gas for electricity generation  

NASA Astrophysics Data System (ADS)

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.

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

2011-10-01

32

IMPACT OF AMMONIA UTILIZATION BY NOX FLUE GAS TREATMENT PROCESSES  

EPA Science Inventory

The report gives results of a study of the impact of ammonia (NH3) utilization by NOx flue gas treatment (FGT) processes. The most technolologically advanced FGT system for the highly efficient (about 90%) removal of NOx from power plang stack gas is selective catalytic reduction...

33

Impact of Ammonia Utilization by NOx Flue Gas Treatment Processes.  

National Technical Information Service (NTIS)

The report gives results of a study of the impact of ammonia (NH3) utilization by NOx flue gas treatment (FGT) processes. The most technolologically advanced FGT system for the highly efficient (about 90%) removal of NOx from power plang stack gas is sele...

T. A. Burnett H. L. Faucett

1979-01-01

34

Impact Damage in Sandwich Composite Structures From Gas Gun Tests  

Microsoft Academic Search

The paper studies the High Velocity Impact (HVI) response of aircraft structures by means of gas gun impact tests and post-test\\u000a NDE evaluation. The scope of the activity comprises structural components such as stringer stiffened composite panels and\\u000a a range of composite sandwich structures, with projectiles such as ice, synthetic birds, runway debris and tyre\\/rim debris.\\u000a The tests and simulations

Nathalie Toso-Pentecote; Alastair Johnson

35

Impact damage on shielded gas-filled vessels  

Microsoft Academic Search

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

F. Schäfer; E. Schneider; M. Lambert

2001-01-01

36

Oil and gas impacts in northern Alaska  

NASA Astrophysics Data System (ADS)

Efforts by the oil industry and regulatory agencies have reduced, but not eliminated, the adverse environmental effects of oil and gas exploration and production on Alaska's North Slope, according to a 5 March report issued by the U.S. National Research Council. The report found that within the 230,000- square-kilometer North Slope region, there have been substantial improvements in seismic exploration technologies and that operators have been more careful.“The technology used for obtaining seismic data continues to improve, but there is still potential damage to the tundra because of the large camps, the number of vehicles used, and the higher spatial density of [three-dimensional seismic] trails. The new technology has reduced but not totally eliminated damage to the tundra,” the report said.

Showstack, Randy

37

Oil and Gas Impacts in Northern Alaska  

NASA Astrophysics Data System (ADS)

Efforts by the oil industry and regulatory agencies have reduced, but not eliminated, the adverse environmental effects of oil and gas exploration and production on Alaska's North Slope, according to a 5 March report issued by the U.S. National Research Council. The report found that within the 230,000- square-kilometer North Slope region, there have been substantial improvements in seismic exploration technologies and that operators have been more careful. ``The technology used for obtaining seismic data continues to improve,but there is still potential damage to the tundra because of the large camps, the number of vehicles used, and the higher spatial density of [three-dimensional seismic] trails. The new technology has reduced but not totally eliminated damage to the tundra,'' the report said.

Showstack, Randy

38

Mitigating oil and gas impacts in coastal wetlands  

USGS Publications Warehouse

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.

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

1989-01-01

39

Impact of efficiency standards on commercial gas water heaters. Topical report, April 1992March 1993  

Microsoft Academic Search

The objective of the investigation was to assess the possible impacts of ASHRAE 90.1b and the DOE Federal Building Standards on commercial gas water heaters. The gas industry had expressed concern that either requirement could impact gas equipment more than electric, resulting in a potential loss of market share and a negative impact on the users of commercial gas water

Topping

1993-01-01

40

Impact of greenhouse gas emissions reduction in Indonesia: NO2  

NASA Astrophysics Data System (ADS)

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

Susandi, A.

2004-12-01

41

Evaluating the income and employment impacts of gas cooling technologies  

SciTech Connect

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.

Hughes, P.J. [Oak Ridge National Lab., TN (United States); Laitner, S.

1995-03-01

42

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

PubMed

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

Allen, David T

2014-01-01

43

Potential Impacts of OCS Oil and Gas Activities on Fisheries. Volume 2. Annotated Bibliography for OCS Oil and Gas Impact Studies.  

National Technical Information Service (NTIS)

The volume is the second of two volumes to the final report, Potential Impacts of OCS Oil and Gas Activities on Fisheries. The volume presents an annotated bibliography of published and grey literature related to OCS oil and gas activity impacts of finfis...

L. M. Tear

1989-01-01

44

Ozone impacts of natural gas development in the Haynesville Shale.  

PubMed

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

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

2010-12-15

45

Atmospheric Impacts of Marcellus Shale Gas Activities in Southwestern Pennsylvania  

NASA Astrophysics Data System (ADS)

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 methane in counties with minimal Marcellus activity (Allegheny and Butler counties). Methane concentrations in areas with large numbers of active well sites can reach as high as 20 ppm (~10 times background), and are highly spatially variable. Areas with elevated methane concentrations also exhibited higher ratios of 13CH4/12CH4, consistent with a thermogenic source of the excess methane.

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

2012-12-01

46

Review of oil and gas exploitation impacts on grizzly bears  

SciTech Connect

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.

Schallenberger, A.

1980-01-01

47

Postulated impact craters yield oil and gas, lively debate  

SciTech Connect

Impact craters, also called astroblemes, are the most common landform in the solar system, and several on earth have produced oil and gas. Significant cross-disciplinary study is being aimed at understanding the origin, structure, and economic potential of surface and buried craters worldwide. The Oklahoma Geological Survey and the US Department of Energy organized a workshop to discuss the Ames structure, a feature in Major Country, Okla., along the sprawling, giant Sooner Trend/Ringwood oil producing complex. This rundown is designed to provide basic information gleaned from speakers and abstracts presented at the workshop. OGS is to publish proceedings later. This paper discusses meteors vs. volcanoes, the Oklahoma crater, questions about Ames, producing astroblemes, and future research.

Petzet, G.A.

1995-04-10

48

Molecular ion fragmentation and its effects on mass isotopomer abundances of fatty acid methyl esters ionized by electron impact  

Microsoft Academic Search

We have analyzed the isotopomer abundance ratios of an equimolar mixture of nine fatty acid methyl esters (decanoate, undecanoate,\\u000a laurate, tridecanoate, myristate, pentadecanoate, palmitate, heptadecanoate, and stearate) by selected-ion monitoring gas\\u000a chromatography\\/electron impact\\/mass spectrometry (GC\\/EI\\/MS). The abundance of the second lowest m\\/z isotopomer ($${I_{{M_1}}}$$) increased disproportionately compared with the abundance of the lowest m\\/z isotopomer ($${I_{{M_0}}}$$) as a function of:

Clifton K. Fagerquist; Richard A. Neese; Marc K. Hellerstein

1999-01-01

49

Solar/gas systems impact analysis study. Final report, September 1982-July 1984  

SciTech Connect

The impacts of solar/gas technologies on gas consumers and on gas utilities was measured separately and compared against the impacts of competing gas and electric systems in four climatic regions of the U.S. A methodology was developed for measuring the benefits or penalties of solar/gas systems on a combined basis for consumers and distribution companies. The authors analysis shows that the combined benefits associated with solar/gas systems are generally greatest when the systems are purchased by customers who would have otherwise chosen high-efficiency electric systems (were solar/gas systems not available in the market place). The role of gas utilities in encouraging consumer acceptance of solar/gas systems was also examined in a qualitative fashion. The authors then developed a decision framework for analyzing the type and level of utility involvement in solar/gas technologies.

Hahn, E.F.; Preble, B.; Neill, C.P.; Loose, J.C.; Poe, T.E.

1984-07-01

50

The greenhouse impact of unconventional gas for electricity generation  

Microsoft Academic Search

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,

Nathan Hultman; Dylan Rebois; Michael Scholten; Christopher Ramig

2011-01-01

51

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

Federal Register 2010, 2011, 2012, 2013

...River National Forest, Colorado, Oil and Gas Leasing Environmental Impact Statement AGENCY...to revise the existing WRNF 1993 Oil and Gas Leasing and Final EIS and Record of Decision...what lands will be available for oil and gas leasing; changing or adding...

2010-06-30

52

A life cycle impact of the natural gas used in the energy sector in Romania  

Microsoft Academic Search

The world's natural gas consumption continues to grow, increasing its market share of total primary energy consumption. Among the major fuels, natural gas is expected to provide the greatest increase in energy consumption in the world energy sector, due to its relatively low environmental impact and high thermodynamic quality. Natural gas plays a significant role in the energy sector because

Cristian Dinca; Patrick Rousseaux; Adrian Badea

2007-01-01

53

Propane-Air Peakshaving Impact on Natural Gas Vehicles. Topical Report, August 1993-January 1997.  

National Technical Information Service (NTIS)

Propane-air peakshaving activities can lead to higher-than-normal propane levels in natural gas. Natural gas vehicle (NGV) fueling station operation and NGV performance can be affected by the presence of excess propane in natural gas. To assess the impact...

M. E. Richards Y. Shikari C. F. Blazek

1997-01-01

54

The aroma development during storage of Castlebrite apricots as evaluated by gas chromatography, electronic nose, and sensory analysis  

Microsoft Academic Search

One of the most important factors limiting apricot quality is the loss of flavor during storage, particularly overall aroma. To characterize fruit aroma, several techniques have been used, including both instrumental- and sensory-based methodologies. Despite the importance of aroma in fruit quality, limited information is available regarding the effects of long-term cold storage and ripening on the apricot’s volatile compound

B. G. Defilippi; H. Valdés; M. A. Moya-León; R. Infante; R. Campos-Vargas

2009-01-01

55

Impact of Natural Gas Infrastructure on Electric Power Systems  

Microsoft Academic Search

The restructuring of electricity has introduced new risks associated with the security of natural gas infrastructure on a significantly large scale, which entails changes in physical capabilities of pipelines, operational procedures, sensors and communications, contracting (supply and transportation), and tariffs. This paper will discuss the essence of the natural gas infrastructure for supplying the ever-increasing number of gas-powered units and

MOHAMMAD SHAHIDEHPOUR; Yong Fu; THOMAS WIEDMAN

2005-01-01

56

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

NASA Astrophysics Data System (ADS)

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.

Yang, Yang

57

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

Microsoft Academic Search

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

Conner

1999-01-01

58

Impacts of Unconventional Gas Technology in the Annual Energy Outlook 2000  

EIA Publications

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 EnergyOutlook 2000 (AEO2000).

Information Center

2000-11-01

59

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 ...

60

Handbook for Estimating the Potential Air Quality Impacts Associated with Oil and Gas Development Offshore California.  

National Technical Information Service (NTIS)

This report consists of a workbook to estimate onshore air quality impacts associated with the exploration, development, and production of oil and gas resources offshore California. The handbook consists of two sections. The first section presents emissio...

1983-01-01

61

Impacts of winter storms on air-sea gas exchange  

NASA Astrophysics Data System (ADS)

The objective of this study is to investigate air-sea gas exchange during winter storms, using field measurements from Ocean Station Papa in the Northeast Pacific (50°N, 145°W). We show that increasing gas transfer rates are coincident with increasing winds and deepening depth of bubble penetration, and that this process depends on sea state. Wave-breaking is shown to be an important factor in the gas transfer velocity during the peaks of the storms, increasing the flux rates by up to 20%. Gas transfer rates and concentrations can exhibit asymmetry, reflecting a sudden increase with the onset of a storm, and gradual recovery stages.

Zhang, Weiqing; Perrie, Will; Vagle, Svein

2006-07-01

62

Shale gas development impacts on surface water quality in Pennsylvania.  

PubMed

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

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

2013-03-26

63

Shale gas development impacts on surface water quality in Pennsylvania  

PubMed Central

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.

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

2013-01-01

64

Impact of gas-filled hohlraum hydrodynamics on symmetry  

NASA Astrophysics Data System (ADS)

Ignition hohlraum designs use low Z gas fill to slow down the inward progress of high Z ablated plasma from the hohlraum walls preventing large laser spot motion and capsule drive asymmetries. However, the localized laser heating of the gas fill produces an early pressure spike on the target axis that couples to the capsule. In order to validate the hydrodynamics in the ignition hohlraum codes, this gas hydro-coupling to a fusion capsule is presently being assessed in experiments with the Omega laser. We study the hohlraum hydrodynamics and symmetry for various gas fill pressures using backlit low-density foam balls and high Z gas fill dopants. To isolate the effect of the gas hydro-coupling pressure, we have first used plastic hohlraums to reduce the x-ray ablation pressure at early times (Tr 70 eV). Similar to the simulations, the foam balls measured by x-ray backlighting show increasing pole-hot pressure asymmetry for increasing gas pressure. The Xe dopant emission shows the early pressure spike formation and its propagation towards the foam ball, as well as the gas-wall interface late motion towards the hohlraum axis, both effects to be compared to simulations. This work was performed under the auspices of the U.S. DOE by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.

Dewald, Eduard; Pollaine, Steve; Landen, Otto; Turner, Robert; Wallace, Russell; Amendt, Peter; Campbell, Kelly; Glenzer, Siegfried

2003-10-01

65

Hydraulic Fracturing and Shale Gas Production: Technology, Impacts, and Policy.  

National Technical Information Service (NTIS)

Hydraulic fracturing is a key technique that has enabled the economic production of natural gas from shale deposits, or plays. The development of large-scale shale gas production is changing the U.S. energy market, generating expanded interest in the usag...

A. Burnham C. Clark C. Harto R. Horner

2012-01-01

66

Impact of Gas Heating in Inductively Coupled Plasmas  

NASA Technical Reports Server (NTRS)

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.

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

67

Impact of Recent Discoveries on Petroleum and Natural Gas Exploration: Emphasis on India  

Microsoft Academic Search

Two discoveries have greatly impacted understanding relevant to the origination and emplacement of petroleum and natural gas deposits. One discovery, pertaining to hydrocarbon formation from methane broadens significantly potential regions where abiotic petroleum and natural gas deposits might be found. The other, discovery of the physical impossibility of Earth-mantle convection, restricts the range and domain of geodynamic behavior, and leads

J. Marvin Herndon

2010-01-01

68

Gas filtration during the impact of weak shock waves on granular layers  

Microsoft Academic Search

This paper deals with the unsteady gas filtration through a granular layer attached to a rigid end-wall when impacted head-on by a weak shock wave in a shock tube. The main goal of the present work is to study the gas pressure field developed inside the granular layer during its compression by the shock wave. A physical model is proposed

A. Britan; G. Ben-Dor; T. Elperin; O. Igra; J. P. Jiang

1997-01-01

69

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

Microsoft Academic Search

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 of formaldehyde, a hazardous air pollutant

Eduardo P. Olaguer

2012-01-01

70

The Potential Near Source Ozone Impacts of Upstream Oil and Gas Industry Emissions  

Microsoft Academic Search

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 of formaldehyde, a hazardous air pollutant

Eduardo P. Olaguer

2012-01-01

71

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

National Technical Information Service (NTIS)

A gas-actuated penetration device has been developed for high-energy impact testing of structures. The high-energy impact testing is for experimental simulation of uncontained engine failures. The non-linear transient finite element, code LS-DYNASD has be...

D. R. Ambur N. Jaunky R. E. Lawson N. F. Knight K. H. Lyle

1999-01-01

72

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

Microsoft Academic Search

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

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

2001-01-01

73

Health Impact Assessment of Shale Gas Extraction. Workshop Summary.  

National Technical Information Service (NTIS)

Natural gas extraction from shale formations which includes hydraulic fracturing is increasingly in the news as the use of extraction technologies has expanded, rural communities have been transformed seemingly overnight, public awareness has increased, a...

C. Coussens R. M. Martinez

2014-01-01

74

Impact of shale gas development on regional water quality.  

PubMed

Unconventional natural gas resources offer an opportunity to access a relatively clean fossil fuel that could potentially lead to energy independence for some countries. Horizontal drilling and hydraulic fracturing make the extraction of tightly bound natural gas from shale formations economically feasible. These technologies are not free from environmental risks, however, especially those related to regional water quality, such as gas migration, contaminant transport through induced and natural fractures, wastewater discharge, and accidental spills. We review the current understanding of environmental issues associated with unconventional gas extraction. Improved understanding of the fate and transport of contaminants of concern and increased long-term monitoring and data dissemination will help manage these water-quality risks today and in the future. PMID:23687049

Vidic, R D; Brantley, S L; Vandenbossche, J M; Yoxtheimer, D; Abad, J D

2013-05-17

75

Gas PreTreatment and their Impact on Liquefaction Processes  

Microsoft Academic Search

Summary Natural gas generally requires removal of H2S, CO2, COS, organic sulphur compounds, mercury and water prior to liquefaction in order to meet product specifications, avoid blockages and to prevent damage to process equipment. The cost of pre-treatment is dependent on the type and concentrations of the contaminants in the natural gas. Most of the operational base load LNG plants

J. M. Klinkenbijl; M. L. Dillon; E. C. Heyman

76

Energy Market Impacts of Alternative Greenhouse Gas Intensity Reduction Goals  

EIA Publications

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).

John J. Conti

2006-03-08

77

Very-High-Temperature Gas Reactor Environmental Impacts Assessment.  

National Technical Information Service (NTIS)

The operation of a Very High Temperature Reactor (VHTR), a slightly modified General Atomic type High Temperature Gas-Cooled Reactor (HTGR) with 1600 F primary coolant, as a source of process heat for the 1400 exp 0 F steam-methanation reformer step in a ...

C. D. Baumann C. J. Barton E. L. Compere T. H. Row

1977-01-01

78

The greenhouse impact of unconventional gas for electricity generation  

NASA Astrophysics Data System (ADS)

In our discussion of the use of global warming potential (GWP) values in the Howarth et al (2011) paper, our text implies that the GISS group's 2009 and 2010 papers (Shindell et al 2009 and Unger et al 2010) were contradictory. Such an interpretation does not reflect the conclusions of those papers and was not our intention. First, the 2009 and 2010 papers address GWP and radiative forcing, respectively. Our intentions in that paragraph were (a) to illustrate the possible ways that the GWP and radiative forcing discussions in the scientific community were misapplied to lifecycle analysis of greenhouse gas emissions from unconventional gas extraction, and (b) to underscore that the reasonable questions about GWP raised by Shindell et al (2009) are a justification for retaining a broader, rather than narrower, range of GWP possibilities for this calculation. References Howarth R W, Santoro R and Ingraffea A 2011 Methane and the greenhouse-gas footprint of natural gas from shale formations Clim. Change Lett. 106 679-90 Shindell D T, Faluvegi G, Koch D M, Schmidt G A, Unger N and Bauer S E 2009 Improved attribution of climate forcing to emissions Science 326 716-8 Unger N, Bond T C, Wang J S, Koch D M, Menon S, Shindell D T and Bauer S E 2010 Attribution of climate forcing to economic sectors Proc. Natl Acad. Sci. 107 3382-7

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

2011-12-01

79

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

NASA Astrophysics Data System (ADS)

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 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 Australian Commonwealth and State Governments. Finally, parallels (and differences) between the expansion of the industry in Australia with that in the United States and Europe will be drawn.

Post, David

2014-05-01

80

Air Toxics Regulations and Their Potential Impact on the Natural Gas Industry. Topical Report, June 1991-October 1992.  

National Technical Information Service (NTIS)

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 representativ...

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

1992-01-01

81

The impact of gas extraction on landfill-generated methane gas levels  

Microsoft Academic Search

The changes measured in landfill-generated CH4 gas levels in response to continuous pumping from an augered borehole in the refuse are described. The results of statistical analyses of concentration and pressure levels at a series of probes located radially outward from the gas extraction well are used to characterize the temporal and spatial variations. A drawdown curve arising from the

Anthony J. Crutcher; Edward A. McBean; Frank A. Rovers

1981-01-01

82

Impact facility based upon high frequency two-stage light-gas gun  

Microsoft Academic Search

An impact facility based upon a two-stage high-frequency light-gas gun has been developed to allow fast and low-cost hypervelocity tests. The mechanical configuration and the managing electronic system are presented.The unit is powered only by means of high-pressure gas: no explosive powder is used. The system is managed by a dedicated computer system, which acquires signals from pressure transducers and

F. Angrilli; D. Pavarin; M. De Cecco; A. Francesconi

2003-01-01

83

Impact of Recent Discoveries on Petroleum and Natural Gas Exploration: Emphasis on India  

Microsoft Academic Search

Two discoveries have greatly impacted understanding relevant to the\\u000aorigination and emplacement of petroleum and natural gas deposits. One\\u000adiscovery, pertaining to hydrocarbon formation from methane broadens\\u000asignificantly potential regions where abiotic petroleum and natural gas\\u000adeposits might be found. The other, discovery of the physical impossibility of\\u000aEarth-mantle convection, restricts the range and domain of geodynamic behavior,\\u000aand leads

J. Marvin Herndon

2010-01-01

84

Impact of leaf physiology on gas exchange in a Japanese evergreen broad-leaved forest  

Microsoft Academic Search

We used a multi-layer model to analyse the impact of leaf physiology on the diurnal, seasonal, and inter-annual fluctuations in gas exchange in a warm-temperate evergreen broad-leaved forest in Japan. The influences of physiological parameters at the single leaf scale on the canopy scale gas exchange were investigated, including normalised dark respiration rate, Rnleaf25, normalised maximum carboxylation rate, Vcmax25, and

Yoshiko Kosugi; Satoru Takanashi; Naoko Matsuo; Katsunori Tanaka; Hiroki Tanaka

2006-01-01

85

Massive gas injections in JET - Impact on wall conditions  

NASA Astrophysics Data System (ADS)

Disruptions are a critical issue for large scale tokamaks due to the potential damage to plasma facing components. Massive Gas Injection (MGI) is considered as a 'last resort' method for disruption mitigation. A MGI system based on the Disruption Mitigation Valve (DMV) has been brought into operation at JET. Injections of neon, argon and its mixtures with deuterium show distinct effects on the machine condition during and after MGI-induced disruptions. MGI with pure argon shows a continuous accumulation in consecutive pulses. Neon on the contrary shows a fast saturation due to trapping in carbon PFCs.

Jet Efda Contributors Kruezi, Uron; Lehnen, M.; Philipps, V.; Brezinsek, S.; Sergienko, G.; Bozenkhov, S.; Jachmich, S.; Morgan, P. D.; Matthews, G. F.

2011-08-01

86

Electron-impact double ionization of rare-gas ions  

NASA Astrophysics Data System (ADS)

Cross sections for the removal of two electrons from rare-gas ions by single collisions with incident electrons have been both measured using crossed beams of ions and electrons, and calculated using Hartree-Fock distorted-wave theory. For initial ions Ar4+, Kr4+, and Xe4+ the measured peak cross sections are 1.4 × 10-18, 6.5 × 10-18 cm2, respectively. These measurements confirm and extend the measurements of Müller and Frodl and of Achenbach et al. Calculations were performed for the charge-state-4 + ions and for Xe+, Xe2+, and Xe3+. Comparison of experiment and theory indicates that the double ionization of rare-gas ions is dominated by the indirect mechanism of inner-shell single ionization followed by autoionization. The distorted-wave calculations for the 4d ionization cross section of Xeq+ (q=1 to 4) ions are strongly influenced by term dependence in the ejected-electron continuum, and by ground-state correlations.

Pindzola, M. S.; Griffin, D. C.; Bottcher, C.; Crandall, D. H.; Phaneuf, R. A.; Gregory, D. C.

1984-04-01

87

Gas desorption and up-scaling errors in CBM groundwater impact simulations  

NASA Astrophysics Data System (ADS)

Coalbed Methane (CBM) is a major energy resource in Australia. Production of CBM requires the extraction of large amounts of groundwater to enable gas desorption from the coalbeds. As CBM raises concerns regarding its impact on adjacent aquifer systems, groundwater models are often required for groundwater impact assessment. Questions arise about the suitability of traditional groundwater flow simulators for CBM groundwater impact quantification as 1) the gas phase is not simulated and 2) up-scaled properties are used that might not reflect coalbed properties appropriately. First, this study aims to quantify the errors incurred by neglecting gas desorption by comparing a CBM reservoir simulator (Eclipse) with an equivalent groundwater flow model (MODFLOW-USG) for a single 1m coal seam. Simulations show the groundwater model significantly overestimates drawdowns during the CBM production stage, as the desorbed gas volume is not accounted for, which impacts storage and the relative permeability of water that are assumed to be constant in the groundwater model. To improve the match between the groundwater model and CBM reservoir simulations, MODFLOW-USG was configured to implement a relationship that was obtained using a pseudo steady-state relationship between drawdown and desaturation derived from Eclipse simulations. A second set of simulations for a sequence of coalbeds was performed to quantify the impact of up-scaling on predicting drawdowns and to validate whether relative permeability curves in the CBM reservoir simulator still have integrity in an up-scaled context. These simulations will help understand how physically representative different up-scaled models are, what errors could be made when regional groundwater modelling is undertaken in a CBM environment and ultimately help decide whether a groundwater flow simulator can be used for CBM groundwater impact assessments. Key words: Coalbed Methane, Up-scaling, Reservoir model, Groundwater model, Dual-phase flow, Gas desorption, MODFLOW, Eclipse

Herckenrath, D.; Doherty, J.

2013-12-01

88

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

NASA Astrophysics Data System (ADS)

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.

Zhou, Chao; Xing, Tingwen

2013-08-01

89

The impact of landfilling and composting on greenhouse gas emissions--a review.  

PubMed

Municipal solid waste is a significant contributor to greenhouse gas emissions through decomposition and life-cycle activities processes. The majority of these emissions are a result of landfilling, which remains the primary waste disposal strategy internationally. As a result, countries have been incorporating alternative forms of waste management strategies such as energy recovery from landfill gas capture, aerobic landfilling (aerox landfills), pre-composting of waste prior to landfilling, landfill capping and composting of the organic fraction of municipal solid waste. As the changing global climate has been one of the major environmental challenges facing the world today, there is an increasing need to understand the impact of waste management on greenhouse gas emissions. This review paper serves to provide an overview on the impact of landfilling (and its various alternatives) and composting on greenhouse gas emissions taking into account streamlined life cycle activities and the decomposition process. The review suggests greenhouse gas emissions from waste decomposition are considerably higher for landfills than composting. However, mixed results were found for greenhouse gas emissions for landfill and composting operational activities. Nonetheless, in general, net greenhouse gas emissions for landfills tend to be higher than that for composting facilities. PMID:19155172

Lou, X F; Nair, J

2009-08-01

90

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

PubMed

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

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

2012-08-01

91

Beyond the ?Double Dividend?: Modelling the impacts of deep cuts in Australian greenhouse gas emissions  

Microsoft Academic Search

Australian economic modelling of policy options to reduce greenhouse gas emissions has to date given little attention to (i) crafting policy scenarios that use emissions revenues to target significant existing tax distortions, (ii) quantifying the effects of policy on the price and affordability of energy products, and (iii) communicating policy impacts on living standards relative to current levels, as well

Steve Hatfield-Dodds; Philip D. Adams

2007-01-01

92

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...

93

Quantitative fluid inclusion gas analysis of airburst, nuclear, impact and fulgurite glasses  

Microsoft Academic Search

We present quantitative fluid inclusion gas analysis on a suite of violently-formed glasses. We used the incremental crush mass spectrometry method (Norman & Blamey, 2001) to analyze eight pieces of Libyan Desert Glass (LDG). As potential analogues we also analyzed trinitite, three impact crater glasses, and three fulgurites. The 'clear' LDG has the lowest CO content and O\\/Ar ratios are

John Parnell; Horton E. Newsom; Nigel J. F. Blamey; Mark Bruce Elrick Boslough

2010-01-01

94

Field ionization kinetic and electron impact studies of gas phase transition states - The cyclic bromonium ion  

NASA Technical Reports Server (NTRS)

Cis- and trans-isomers of 4-t-butylcyclohexyl bromide were studied to determine the mechanism of cyclic bromonium ion formation. The field ionization kinetic and electron impact data indicate that the formation of the cyclic structure occurs simultaneously with loss of the neutral fragment. The data also show that little or no gas-phase cis-trans isomerization occurs.

Green, M. M.; Giguere, R. J.; Falick, A. M.; Aberth, W.; Burlingame, A. L.

1978-01-01

95

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...

96

Impact of Natural Gas Pipeline on Mineral and Energy Development in Alaska.  

National Technical Information Service (NTIS)

The impact of one primary and seven alternative natural gas pipeline routes and their alternatives on Alaska's mining industry is discussed. Four routes begin on Alaska's North Slope and lead to the 48 contiguous States via Canada, while three routes lead...

R. G. Bottge

1975-01-01

97

The use of health impact assessment for a community undergoing natural gas development.  

PubMed

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

Witter, Roxana Z; McKenzie, Lisa; Stinson, Kaylan E; Scott, Kenneth; Newman, Lee S; Adgate, John

2013-06-01

98

A review of ecological impacts of oil and gas development on coastal ecosystems in the Mississippi Delta  

Microsoft Academic Search

We review the multiple ecological impacts of oil and gas development on coastal ecosystems in the Mississippi Delta. This area has one of the greatest developments of oil and gas production in the world. This activity has generated significant impacts on coastal ecosystems due to the toxicity of spilled oil and the secondary and indirect effects of petroleum-related activities, such

Jae-Young Ko; John W. Day

2004-01-01

99

Evaluation of ecological impacts of synthetic natural gas from wood used in current heating and car systems  

Microsoft Academic Search

A promising option to substitute fossil energy carriers by renewables is the production of synthetic natural gas (SNG) from wood, as this results in a flexible energy carrier usable via existing infrastructure in gas boilers or passenger cars. The comprehensive life cycle-based ecological impact of SNG is investigated and compared with standard fuels delivering the same service (natural gas, fuel

Remo Felder; Roberto Dones

2007-01-01

100

Investigating links between shale gas development and health impacts through a community survey project in Pennsylvania.  

PubMed

Across the United States, the race for new energy sources is picking up speed and reaching more places, with natural gas in the lead. While the toxic and polluting qualities of substances used and produced in shale gas development and the general health effects of exposure are well established, scientific evidence of causal links has been limited, creating an urgent need to understand health impacts. Self-reported survey research documenting the symptoms experienced by people living in proximity to gas facilities, coupled with environmental testing, can elucidate plausible links that warrant both response and further investigation. This method, recently applied to the gas development areas of Pennsylvania, indicates the need for a range of policy and research efforts to safeguard public health. PMID:23552648

Steinzor, Nadia; Subra, Wilma; Sumi, Lisa

2013-01-01

101

Integrated Assessment of Greenhouse Gas Stabilization Concentrations, Emission Pathways, and Impact Threshold Values for Control of Global Warming  

Microsoft Academic Search

To mitigate the dangerous impacts of global warming to the greatest extent possible, various green- house gas stabilization scenarios have been proposed. Integrated studies are proceeding on emission pathways and the costs of achieving climate stabilization, as well as on the impact risks of global warm- ing. This paper summarizes the existing knowledge on temperature rise, mitigation measures and impact

Kiyoshi TAKAHASHI

102

Impacts of Marcellus Shale Natural Gas Production on Regional Air Quality  

NASA Astrophysics Data System (ADS)

Natural gas is a clean burning alternative to other fossil fuels, producing lower carbon dioxide (CO2) emissions during combustion. Gas deposits located within shale rock or tight sand formations are difficult to access using conventional drilling techniques. However, horizontal drilling coupled with hydraulic fracturing is now widely used to enhance natural gas extraction. Potential environmental impacts of these practices are currently being assessed because of the rapid expansion of natural gas production in the U.S. Natural gas production has contributed to the deterioration of air quality in several regions, such as in Wyoming and Utah, that were near or downwind of natural gas basins. We conducted a field campaign in southwestern Pennsylvania on 16-18 June 2012 to investigate the impact of gas production operations in the Marcellus Shale on regional air quality. A total of 235 whole air samples were collected in 2-liter electropolished stainless- steel canisters throughout southwestern Pennsylvania in a regular grid pattern that covered an area of approximately 8500 square km. Day and night samples were collected at each grid point and additional samples were collected near active wells, flaring wells, fluid retention reservoirs, transmission pipelines, and a processing plant to assess the influence of different stages of the gas production operation on emissions. The samples were analyzed at Appalachian State University for methane (CH4), CO2, C2-C10 nonmethane hydrocarbons (NMHCs), C1-C2 halocarbons, C1-C5 alkyl nitrates and selected reduced sulfur compounds. In-situ measurements of ozone (O3), CH4, CO2, nitric oxide (NO), total reactive nitrogen (NOy), formaldehyde (HCHO), and a range of volatile organic compounds (VOCs) were carried out at an upwind site and a site near active gas wells using a mobile lab. Emissions associated with gas production were observed throughout the study region. Elevated mixing ratios of CH4 and CO2 were observed in the southwest and northeast portions of the study area indicating multiple emission sources. We also present comparisons of VOC fingerprints observed in the Marcellus Shale to our previous observations of natural gas emissions from the Denver-Julesburg Basin in northeast Colorado to identify tracers for these different natural gas sources.

Swarthout, R.; Russo, R. S.; Zhou, Y.; Mitchell, B.; Miller, B.; Lipsky, E. M.; Sive, B. C.

2012-12-01

103

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

PubMed

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 treated to surface discharge standards by desalination, $59,000-270,000 per well would be required. The life cycle study results indicate that when gas end use is not considered hydraulic fracturing is the largest contributor to the life cycle water impacts of a Marcellus shale gas well. PMID:24380628

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

2014-02-01

104

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

PubMed Central

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 wastewater is treated to surface discharge standards by desalination, $59?000–270?000 per well would be required. The life cycle study results indicate that when gas end use is not considered hydraulic fracturing is the largest contributor to the life cycle water impacts of a Marcellus shale gas well.

2013-01-01

105

Quantifying habitat impacts of natural gas infrastructure to facilitate biodiversity offsetting  

PubMed Central

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. This study demonstrates that impacts of linear infrastructure in regions such as the Ustyurt should be accounted for not just with respect to development sites but also associated transportation and delivery routes.

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

2014-01-01

106

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

PubMed

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

Barth, Jannette M

2013-01-01

107

Evaluation of gas chromatography-atmospheric pressure chemical ionization-mass spectrometry as an alternative to gas chromatography-electron ionization-mass spectrometry: avocado fruit as example.  

PubMed

Although GC-APCI-MS was developed more than 40 years ago this coupling is still far from being a routine technique. One of the reasons explaining the limited use of GC-APCI so far is the lack of spectral database which facilitates the identification of the compounds under study. The first application of a very recently developed GC-APCI database to identify as many compounds as possible in a complex matrix such as avocado fruit is presented here. The results achieved by using this database has been checked against those obtained using traditional GC-EI-MS and a comparison of the MS signals observed in both ionization sources has been carried out. 100 compounds belonging to different chemical families were identified in the matrix under study. Considering the results of this study, the wide range of application (in terms of polarity and size of analytes) and the robustness of APCI as interface, the high quality of TOF spectra, and our library as a publicly available resource, GC-APCI-TOF MS is definitively a valuable addition to the "metabolomics toolbox". PMID:24054422

Hurtado-Fernández, Elena; Pacchiarotta, Tiziana; Longueira-Suárez, Enrique; Mayboroda, Oleg A; Fernández-Gutiérrez, Alberto; Carrasco-Pancorbo, Alegría

2013-10-25

108

Generation of laser-pulse-field harmonics in a gas upon impact ionisation of atoms  

SciTech Connect

The generation of harmonics of a high-power-laser-pulse field in a gas during impact ionisation of atoms by oscillating electrons is studied theoretically. Fields are considered under conditions when the oscillation energy of electrons in the radiation field, remaining nonrelativistic, considerably exceeds the ionisation potential of an atom. In addition, the radiation field was assumed weak compared to the atomic field (E{sub a} = 5.1x10{sup 9} V cm{sup -1}), which allowed us to neglect the field ionisation of atoms, taking into account only the impact ionisation of atoms by oscillating electrons. Under such conditions, along with the elastic scattering of electrons, the inelastic scattering of oscillating electrons accompanied by ionisation of gas atoms can make a significant contribution to a nonlinear current induced in the plasma. (special issue devoted to the 25th anniversary of the a.m. prokhorov general physics institute)

Kuzelev, M V; Rukhadze, A A [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2007-10-31

109

Formation of secondary aerosols: impact of the gas-phase chemical mechanism  

Microsoft Academic Search

The impact of two recent gas-phase chemical kinetic mechanisms (CB05 and RACM2) on the formation of secondary inorganic and organic aerosols is compared for simulations of PM2.5 over Europe between 15 July and 15 August 2001. The host chemistry transport model is Polair3D of the Polyphemus air-quality platform. Particulate matter is modeled with SIREAM, which is coupled to the thermodynamic

Y. Kim; K. Sartelet; C. Seigneur

2010-01-01

110

Preliminary study of counter impact with two-stage light gas gun using electrothermal–chemical gun technology  

Microsoft Academic Search

Recently, hypervelocity impacts between space structures and space debris have been brought to attention with the advance of space development. The impact velocity at low earth orbit (LEO) is up to 15km\\/s. Such impact velocity cannot be attained by the current two-stage light gas gun (TSLGG). Therefore we have a plan of counter impacts that used two sets of TSLGGs

M. Tadaoka; Y. Akahoshi; T. Koura; S. Fukusige; E. Matude; J. Kitagawa; Y. Qu

2006-01-01

111

Life-cycle energy and greenhouse gas emission impacts of different corn ethanol plant types.  

SciTech Connect

Since the United States began a program to develop ethanol as a transportation fuel, its use has increased from 175 million gallons in 1980 to 4.9 billion gallons in 2006. Virtually all of the ethanol used for transportation has been produced from corn. During the period of fuel ethanol growth, corn farming productivity has increased dramatically, and energy use in ethanol plants has been reduced by almost by half. The majority of corn ethanol plants are powered by natural gas. However, as natural gas prices have skyrocketed over the last several years, efforts have been made to further reduce the energy used in ethanol plants or to switch from natural gas to other fuels, such as coal and wood chips. In this paper, we examine nine corn ethanol plant types--categorized according to the type of process fuels employed, use of combined heat and power, and production of wet distiller grains and solubles. We found that these ethanol plant types can have distinctly different energy and greenhouse gas emission effects on a full fuel-cycle basis. In particular, greenhouse gas emission impacts can vary significantly--from a 3% increase if coal is the process fuel to a 52% reduction if wood chips are used. Our results show that, in order to achieve energy and greenhouse gas emission benefits, researchers need to closely examine and differentiate among the types of plants used to produce corn ethanol so that corn ethanol production would move towards a more sustainable path.

Wang, M.; Wu, M.; Huo, H.; Energy Systems

2007-04-01

112

The Deep Impact Campaign at ESO: Observations of the Gas Component  

NASA Astrophysics Data System (ADS)

The high velocity impact of a projectile on the nucleus of comet 9P/Tempel 1 could give for the first time access to pristine material preserved in the cometary interior. From two nights before impact to six nights after impact FORS2 at the VLT UT 1 is available every night to obtain low resolution optical spectra. These will be used to study the chemical composition of the coma by studying emissions from CN, C2, C3 and NH2, and to identify variations due to the impact. Possibly, a new surface of fresh ices in the impact crater will be present. We also intend to perform medium resolution near infrared spectroscopy using ISAAC at the VLT UT 1 to observe organic parent molecules directly instead of observing daughter products that can be addressed by optical observations. This contribution will present first results from the observations of the gas coma around the impact time. The project team comprises the following investigators: N. Ageores, M. A'Hearn, C. Arpigny, S. Bagnulo, H. Boehnhardt, T. Bonev, A. Cochran, C. Delahodde, Y. Fernandez, O. Hainaut, D. Hutsemekers, E. Jehin, H.U. Kaeufl, H. Kawakita, F. Kerber, J. Knollenberg, M. Kretlow, E. Kuehrt, M. Kueppers, L. Lara, J. Licandro, C. Lisse, J. Manfroid, O. Marco, K. Meech, H. Rauer, R. Schulz, G. Schwehm, C. Sterken, M. Sterzik, J.A. Stuewe, I. Surdej, G.P. Tozzi, M. Weiler, R. West, D. Wooden, J.-M. Zucconi

Rauer, H.; ESO DI Project Team

2005-08-01

113

Effect of an impact-generated gas cloud on the acceleration of solid ejecta  

NASA Astrophysics Data System (ADS)

A hypothesis that vaporization of a large amount of volatiles such as H2O and CO2 in the Martian surface by the impact of a large object could have accelerated solid ejecta to earth is examined. A hydrodynamic model is used to approximate a hemispherical gas cloud expanding into an atmosphere and entraining solid ejecta. Account is taken of the target material, the impactor materials, mass vaporized, impact velocity, drag coefficient, and crater sizes. A Martian crater larger than 30 km diam is found to be a necessary remnant of any impact that could have produced the shergottites, nakhlites and Chassigny meteorites which have been found on earth and possess similarities to analyzed Martian rocks.

Vickery, Ann

1986-12-01

114

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

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.

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

2006-06-01

115

Chukchi Sea Oil and Gas Lease Sale 109, Alaska Outer Continental Shelf, Final Environmental Impact Statement. Volume 2.  

National Technical Information Service (NTIS)

The EIS (Final Environmental Impact Statement) analyzes a proposed oil and gas lease sale in the Chukchi Sea, alternatives to the proposal, major issues determined through the scoping process, and potential mitigating measures. The proposal consists of 45...

L. Yoesting

1987-01-01

116

Economic Impact Analysis of Final Effluent Limitations Guidelines and Standards of Performance for the Offshore Oil and Gas Industry.  

National Technical Information Service (NTIS)

The document is an economic impact analysis prepared in support of the promulgation of effluent limitations guidelines and standards of performance for drilling and production wastes for the offshore oil and gas industry. The report analyzes the economic ...

E. M. Sigler M. F. Kaplan

1993-01-01

117

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

NASA Astrophysics Data System (ADS)

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 fine PM2.5 concentrations are reduced as the price of natural gas decreased in Texas. The air quality impacts were predominantly driven by changes in the electricity generation sector rather than in the fuel-supply chain. The areas in which the largest changes in ozone and fine PM were modeled were regions with several coal-fired power plants, which were dispatched less frequently in our model as the price of natural gas decreased. Ozone decreases were largest in magnitude in the afternoon hours during times which were relevant for the daily maximum 8-hour ozone concentration, on which the Federal ozone standard is based. Despite localized increases in NOx and volatile organic compound (VOC) emissions associated with the natural gas production in the Barnett Shale, ozone concentrations were modeled to decrease in the region with decreasing natural gas prices.

Allen, D.; Pacsi, A. P.

2013-12-01

118

Production of Carbon Clusters by Impact Reaction Using Light-Gas Gun in Experiment Modeling Asteroid Collision  

Microsoft Academic Search

To investigate the production of carbon clusters by the impact reaction occurring when an asteroid collides with a satellite, a model experiment using a 2-stage light-gas gun is carried out. A small metal ball of 3 km\\/s velocity is injected into a thin isopropyl-alcohol layer with a metal back plate in nitrogen gas. After the impact reaction, the carbon soot

Tetsu Mienoand; Sunao Hasegawa

2008-01-01

119

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

120

Using the CQIM to assess the benefits of gas cofiring. Topical report, December 1990. [Coal Quality Impact Model  

SciTech Connect

The capability of the Coal Quality Impact Model (CQIM), which presently models the performance and operating costs of power plants that burn only coal, was evaluated to consider gas cofiring. The report includes an explanation of how the CQIM evaluates coal quality impacts and the identification of potential enhancements to the model which address issues specific to cofiring.

Anderson, A.A.; Mitas, D.W.; Stallard, G.S.; McDaniel, D.L.

1990-12-01

121

A multidisciplinary approach to evaluate the environmental impact of offshore gas platforms in the western Adriatic Sea  

Microsoft Academic Search

Detecting the anthropogenic impacts of offshore gas platforms requires reliable tools, because the traditional evaluation based only on chemical analyses is neither appropriate nor sufficiently sensitive. Thus, a 3-year monitoring project was carried out to evaluate the impact of a platform based on a chemical–biological approach. Benthic communities are investigated as they are widely used to monitor the effects of

A. Gomiero; A. M. De Biasi; L. Da Ros; C. Nasci; A. Spagnolo; G. Scarcella; G. Fabi

2011-01-01

122

Economic impact analysis of final effluent limitations guidelines and standards of performance for the offshore oil and gas industry  

Microsoft Academic Search

The document is an economic impact analysis prepared in support of the promulgation of effluent limitations guidelines and standards of performance for drilling and production wastes for the offshore oil and gas industry. The report analyzes the economic impact of alternative regulatory options considered for drilling fluids, drill cuttings, produced water, produced sand, and treatment, workover, and completion fluids.

M. F. Kaplan; E. M. Sigler

1993-01-01

123

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

NASA Astrophysics Data System (ADS)

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. Overall, emissions associated with shale gas activities in South Texas have been affecting ozone air quality in neighboring urban areas. Developing effective control strategies for reducing emissions from shale gas activities and improving ozone air quality is an important issue in Texas and other states in the U.S..Changes in percentage of summertime 4th highest ozone daily maximum as comparing to previous year

Chang, C.; Liao, K.

2013-12-01

124

Impacts of river bed gas on the hydraulic and thermal dynamics of the hyporheic zone  

NASA Astrophysics Data System (ADS)

Despite the presence of gas in river beds being a well known phenomenon, its potential feedbacks on the hydraulic and thermal dynamics of the hyporheic zone has not been widely studied. This paper explores hypotheses that the presence of accumulated gas impacts the hydraulic and thermal dynamics of a river bed due to changes in specific storage, hydraulic conductivity, effective porosity, and thermal diffusivity. The hypotheses are tested using data analysis and modelling for a study site on the urban River Tame, Birmingham, UK. Gas, predominantly attributed to microbial denitrification, was observed in the river bed up to around 14% by volume, and to at least 0.8 m depth below river bed. Numerical modelling indicates that, by altering the relative hydraulic conductivity distribution, the gas in the river bed leads to an increase of groundwater discharge from the river banks (relative to river bed) by a factor of approximately 2 during river low flow periods. The increased compressible storage of the gas phase in the river bed leads to an increase in the simulated volume of river water invading the river bed within the centre of the channel during storm events. The exchange volume can be more than 30% greater in comparison to that for water saturated conditions. Furthermore, the presence of gas also reduces the water-filled porosity, and so the possible depth of such invading flows may also increase markedly, by more than a factor of 2 in the observed case. Observed diurnal temperature variations within the gaseous river bed at 0.1 and 0.5 m depth are, respectively, around 1.5 and 6 times larger than those predicted for saturated sediments. Annual temperature fluctuations are seen to be enhanced by around 4 to 20% compared to literature values for saturated sediments. The presence of gas may thus alter the bulk thermal properties to such a degree that the use of heat tracer techniques becomes subject to a much greater degree of uncertainty. Although the likely magnitude of thermal and hydraulic changes due to the presence of gas for this site have been demonstrated, further research is needed into the origins of the gas and its spatial and temporal variability to enable quantification of the significance of these changes for chemical attenuation and hyporheic zone biology.

Cuthbert, M. O.; Mackay, R.; Durand, V.; Aller, M.-F.; Greswell, R. B.; Rivett, M. O.

2010-11-01

125

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

PubMed

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

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

2009-09-01

126

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

SciTech Connect

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.

Ipe, N.E. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Fasso, A. [European Organization for Nuclear Research, Geneva (Switzerland)

1994-01-01

127

Acute health impact of the gas release at Lake Nyos, Cameroon, 1986  

NASA Astrophysics Data System (ADS)

Available medical evidence on the acute health impact of the gas release at Lake Nyos is summarised, including the results of a survey of medical records of 845 survivors treated at Wum and Nkambe hospitals. The main clinical features were compatible with exposure to an asphyxiant gas such as CO 2 but confirmation of the identity of the gas or gases involved was not possible. Exposure to CO 2 over such a large inhabited area and reversible coma lasting for hours after CO 2 gassing do not appear to have been reported before. In some victims, blistering or ulceration of the skin was present which could not be readily explained by local injury from pressure, or burns from acid, or falling near fires. Further epidemiological studies on survivors are unlikely to be feasible, but the possibility of long-term anoxic brain damage among adults and children who had been rendered comatose by the gas should be considered, though overt evidence of major neurological or respiratory disability was not apparent in survivors in the weeks following the disaster. The inadequacy of the toxicological and forensic evidence obtained points to the need for the rapid mobilisation of medical scientists in future disasters of this kind.

Baxter, Peter J.; Kapila, Mukesh

1989-11-01

128

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

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

129

Impact of fly ash composition on mercury speciation in simulated flue gas.  

PubMed

The impact of different fly ash samples on mercury speciation in simulated flue gas at 140 degrees C was evaluated in this study. Experiments were conducted in a fixed bed reactor to determine the impact of fly ash morphological characteristics and chemical composition on mercury uptake and oxidation. No homogeneous mercury oxidation was observed at 140 degrees C. Mercury uptake tests with different fly ash samples revealed that loss on ignition (LOI), surface area, and particle size all had positive effects on mercury oxidation and adsorption (i.e., as the above parameters increased, mercury adsorption and oxidation also increased). Experiments with pure inorganic components showed that alumina (A12O3), silica (SiO2), calcium oxide (CaO), magnesium oxide (MgO), and titania (TiO2) do not promote mercury oxidation or adsorption. Ferric oxide (Fe2O3) and unburned carbon, on the other hand, showed significant mercury oxidation and capture. PMID:19947114

Bhardwaj, Ravi; Chen, Xihua; Vidic, Radisav D

2009-11-01

130

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

131

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

SciTech Connect

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.

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

1983-04-01

132

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

SciTech Connect

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.

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

1993-11-01

133

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

SciTech Connect

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.

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

134

PVDF Gauge Piezoelectric Response under Two-Stage Light Gas Gun Impact Loading  

NASA Astrophysics Data System (ADS)

Stress gauges based on ferroelectric polymer (PVDF) studies under very high pressure shock compression have shown that the piezoelectric response exhibits a precise reproducible behavior up to 25 GPa. Shock pressure profiles obtained with "in situ" PVDF gauges in porous H.E. (Formex) in a detonation regime have been achieved. Observations of a fast superpressure of a few nanoseconds followed by a pressure release have raised the question of the loading path dependence of the piezoelectric response of PVDF at high shock pressure levels. Consequently, studies of the piezoelectric behavior of PVDF gauges under impact loading using a two-stage light gas gun have been conducted recently. Symmetric impact as well as non symmetric impact and reverse impact techniques have been achieved. Strong viscoplastic behavior of some materials is observed. In typical experiments, the piezoelectric response of PVDF at shock equilibrium could be determined. These results show that the PVDF response appears independent of the loading path up to 30 GPa. Accurate measurements in situ H.E. are also reported with very low inductance PVDF gauges.

Bauer, Francois

2002-07-01

135

PVDF Gauge Piezoelectric Response Under Two-Stage Light Gas Gun Impact Loading  

NASA Astrophysics Data System (ADS)

Stress gauges based on PVDF studies under very high pressure shock compression have shown that the piezoelectric response of shock compressed PVDF film exhibits precise reproducible behavior to 25 GPa. Shock pressure profiles obtained with in situ PVDF gauges in porous H.E. (Formex) in a detonation regime have been achieved. Observations of fast superpressure of a few nanoseconds followed by a pressure release have raised the question of the loading path dependence of the piezoelectric response of PVDF at high shock pressure levels. Consequently, studies of the piezoelectric behavior of PVDF gauges under impact loading using a two-stage light gas gun have been conducted recently. Symmetric impact as well as non-symmetric impact and reverse impact techniques have been achieved. Strong visco-plastic behavior of some materials are observed. In typical experimentations, piezoelectric response of PVDF at shock equilibrium could be determined. These results show that the PVDF response appears to not depend of the loading path up to 30 GPa. Accurate measurements in situ H.E. are also reported with very low inductance PVDF gauges.

Bauer, Francois

2001-06-01

136

Soil, Water, and Greenhouse-gas Impacts of Alternative Biomass Cropping Systems  

NASA Astrophysics Data System (ADS)

Through the 2008 Energy Independence and Security Act and other state and federal mandates, the U.S. is embarking on an aggressive agenda to reduce dependency on fossil fuels. While grain-derived ethanol will be used to largely meet initial renewable fuels targets, advanced biofuels derived from lignocellulosic materials are expected to comprise a growing proportion of the renewable energy portfolio and provide a more sustainable solution. As part of our interdisciplinary research, we are assessing the environmental impacts of four lignocellulosic biomass cropping systems and comparing them to a conventional corn cropping system. This comparison is conducted using a randomized, replicated experiment initiated in fall 2008, which compares the five cropping systems across a toposequence (i.e., floodplain, toeslope, backslope, shoulder, summit). In addition to assessing herbaceous and woody biomass yields, we are evaluating the environmental performance of these systems through changes in water quality, greenhouse-gas emissions, and carbon pools. Initial results document baseline soil parameters, including the capacity of the soils to sequester carbon across the toposequence, and the impacts of landscape heterogeneity and cropping system on soil moisture and nitrate-nitrogen levels in the vadose zone. Additional results on greenhouse-gas emissions and carbon dynamics are forthcoming from this year’s field research. The fuller understanding of the environmental performance of these systems will help inform federal and state policies seeking to incentivize the development of a sustainable bioenergy industry.

Schulte Moore, L. A.; Bach, E.; Cambardella, C.; Hargreaves, S.; Helmers, M.; Hofmockel, K.; Isenhart, T.; Kolka, R. K.; Ontl, T.; Welsh, W.; Williams, R.; Landscape Biomass Team

2010-12-01

137

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

SciTech Connect

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 accidental fire, greater period of danger to emergency personnel, increased unavoidable loss of gas, and possible depressurization cooling of the shut-off valves may also be important when deciding whether a change in the required valve spacing would be beneficial from a safety standpoint. (4) The average normalized discharge rate of {lambda}{sub avg} = 0.33 assumed by Stephens in developing his safety criteria is an excellent conservative value for natural gas discharge at the pressures, valve spacings, and pipe diameter used in this study. This conclusion remains valid even when real rather than ideal gas properties are considered in the analysis. (5) Significant pipe wall cooling effects (T{sub w} < -50 F or 228 K) can extend for a mile or more upstream from the rupture point within 30 s of a break. These conditions are colder than the temperature range specifications for many valve lubricants. The length of the low-temperature zone due to this cooling effect is also essentially independent of the system shut-off valve spacing or the distance between the break and a compressor station. (6) Having more redundant shut-off valves available would reduce the probability that pipe cooling effects could interfere with isolating the broken area following a pipeline rupture accident.

Sulfredge, Charles David [ORNL

2007-07-01

138

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

NASA Astrophysics Data System (ADS)

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.

Mac Kinnon, Michael

139

Lyman Alpha Mapping Project (LAMP) Detections of LCROSS Impact Plume Gas  

NASA Astrophysics Data System (ADS)

The Lyman Alpha Mapping Project (LAMP) is an ultraviolet (UV) spectrograph on the Lunar Reconnaissance Orbiter (LRO) that is designed to map the lunar albedo at far-UV wavelengths. LAMP's spectral range of 57.5 nm to 196.5 nm includes emission line features from several known and expected lunar atmosphere constituents, including resonantly scattered Lyman-alpha (121.57 nm) emissions from hydrogen atoms and argon atom emissions at 104.82 nm and 106.67 nm. The LCROSS impact on 9 October 2009 elevated and exposed water ice and other volatiles trapped near the lunar surface (Colaprete et al., submitted, 2010). Observations with LRO/LAMP detected enhancements of volatile species in the plume shortly after impact (Gladstone et al., submitted, 2009). The plume of rapidly expanding gas includes molecular hydrogen gas seen by sunlit fluorescence. Resonantly scattered emissions from atomic Hg, Mg, and Ca in sunlight are also likely detected in a feature near 185 nm. The molecular hydrogen content within permanently shadowed regions (PSRs) is higher than possible through dissociation of water alone, which indicates that trapped hydrogen gas likely contributes to the hydrogen content of the PSRs in addition to the water detected there. The concentration of mercury in PSRs has implications for future exploration and in situ resource utilization in these regions. This investigation addresses how water and other volatiles arrive (or form) at the lunar surface, are transported through the lunar atmosphere, and are deposited within PSRs (or elsewhere), which is closely related to LAMP's primary objectives.

Retherford, Kurt; Gladstone, Randy; Stern, Alan; Hurley, Dana; Feldman, Paul; Pryor, Wayne; Hendrix, Amanda; Goldstein, David; Summy, Dustin

2010-05-01

140

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

141

Mobile Measurements of Leaks Associated with Oil and Gas Development and the Impact on Air Quality  

NASA Astrophysics Data System (ADS)

In the United States, horizontal drilling and hydraulic fracturing technologies have enabled a rapid increase in the production rate of oil and natural gas. Frequently, the shale sources are located near large urban centers (such as Dallas/Fort Worth, TX) and smaller communities. The transient drilling activity as well as the long-term installation of wells, processing and transmission facilities have the potential to affect associated emissions to the atmosphere of methane, volatile organic compounds, NOx, particulates and other species. Using a mobile laboratory, measurements have been conducted in several active shale play production areas and at specific facilities. The regions include the Barnett shale in Dallas/Fort Worth, the Denver Julesberg Shale near Denver, and the southwest and north-central regions of the Marcellus shale near Pittsburg and Mansfield, respectively. Results of the quantification of the specific natural gas leak rate from specific facilities will be presented and discussed. Also, differences in the emissions profile from the various regions will be highlighted. The intra-regional contrasts will also be presented such as those observed in the Barnett shale in the ethane to methane ratio, demonstrating its use as an "isotope-like" signature of the source. Regional scale measurements of the observed levels of air pollutants downwind and upwind of the shale play sectors will be shown. The data from the Marcellus region will put into context on how further development of the gas resources impacts air quality in a region upwind of the highly urbanized east coast corridor.

Herndon, Scott; DeCarlo, Peter; Yacovitch, Tara; Goetz, Douglass; Floerchinger, Cody; Roscioli, Joseph; Shorter, Joanne; Kolb, Charles

2014-05-01

142

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

NASA Astrophysics Data System (ADS)

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.

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

2003-08-01

143

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

144

Simulation of the impact of thunderstorm activity on atmospheric gas composition  

NASA Astrophysics Data System (ADS)

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.

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

2010-08-01

145

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

PubMed

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

Olaguer, Eduardo P

2012-08-01

146

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

NASA Astrophysics Data System (ADS)

Many atmospheric pollutants have been linked to the lifecycle of unconventional natural gas. Attributing air emissions to particular segments of the natural gas life cycle can be difficult. Further, describing individual and community exposure to air pollutants is complex since contaminants can vary spatially and temporally, based on proximity to point sources, magnitude, transport and dispersion of emissions. Here we will present data from the Barnett Shale formation near Dallas/Fort Worth, TX with the goal of providing a better understanding of the extent to which population exposure to air toxics is associated with emissions from natural gas production operations in this region. The Barnett Shale formation covers nearly 13000 km2 and is located west of Dallas/Fort Worth, TX. This formation contains natural gas, natural gas condensate, and light oil. Samples were collected in April-May 2010 in two phases with the purpose of Phase 1 being to characterize emissions from major gas production facilities in the area, while Phase 2 involved more intensive monitoring of two residential areas identified in Phase 1. One of the residential areas was downwind of a gas well and two condensate tanks and the other area was close to a compressor station. Phase 1 sampling involved our mobile monitoring system, which includes real-time estimates of volatile organic compounds (VOC), using a portable photoionization detector monitor; continuous NO, PM2.5 mass, and a GasFindIR camera. Phase 1 also included 1-hr integrated canister VOC samples and carbonyl compound samples, using DNPH impregnated Sep-Pac Si cartridges. These samples were analyzed by GC/MS and high performance liquid chromatography with a photodiode array detector. Phase 2 sampling included 7-day integrated passive samples for NOx, NO2 and SO2 using Ogawa passive samplers, and BTEX (benzene, toluene, ethylbenzene, and xylenes), 1,3-butadiene, and carbonyl compounds (formaldehyde, acetaldehyde, and acrolein) using 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.

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

2013-12-01

147

Economic Impact Analysis of Final Effluent Limitations Guidelines and Standards for the Coastal Subcategory of the Oil and Gas Extraction Point Source Category.  

National Technical Information Service (NTIS)

This final economic impact analysis (FEIA) examines compliance costs and economic impacts resulting from the U.S. Environmental Protection Agency's (EPA's) Effluent Limitations Guideline and Standards for the Coastal Subcategory of the Oil and Gas Extract...

1996-01-01

148

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

PubMed

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

Adamowicz, Piotr; Ka?a, Maria

2010-05-20

149

2-Phosphoglycolate and glycolate-electrophore detection, including detection of 87 zeptomoles of the latter by gas chromatography-electron-capture mass spectrometry  

Microsoft Academic Search

As a first stage towards a goal of studying some aspects of oxidative damage to DNA and its subsequent repair, we set up three techniques for the detection of 2-phosphoglycolate (PG). This compound is released as a metabolite from the DNA in certain cases of this process. We explored three techniques because we wanted to learn which one(s) would be

Poguang Wang; Veeravagu Murugaiah; Bernice Yeung; Paul Vouros; Roger W. Giese

1996-01-01

150

Gas chromatography-electron ionization mass spectrometry and liquid chromatography-electrospray tandem mass spectrometry for determination of impurities in the anti-cancer drug isophosphoramide mustard  

NASA Astrophysics Data System (ADS)

Isophosphoramide mustard (IPM) is known to have substantial anti-cancer activities in various animal models. Liquid chromatography-electrospray mass spectrometry (LC-ES-MS) and LC-ES-MS/MS methodologies have been developed and applied to the analysis of synthesized preparations of IPM. Our studies reveal that the principal impurity in IPM is N-(2-chloroethyl)-N'-ethylphosphorodiamidic acid (MC-IPM) formed by dehydrochlorination of IPM with subsequent hydrogenation during synthesis. This impurity is present at levels in the range of 2-5% depending upon synthesis conditions. In addition, a second IPM derivative has been characterized by LC-ES-MS/MS and has been shown to be the product of a reaction of IPM with the dilute perchloric acid mobile phase used for liquid chromatography separations. The LC-ES-MS/MS method has been successfully employed to detect IPM spiked into a blood plasma sample. This work establishes that LC-ES-MS/MS is a viable tool for the detailed characterization of IPM and related products.

Cole, Richard B.; Chou, Chau-Wen; Boué, Stephen M.; Leblanc, Blaise W.; Rodgers, Andrew H.; Struck, Robert F.; Morgan, Lee Roy

2004-02-01

151

Optimization of solid-phase extraction and solid-phase microextraction for the determination of ?- and ?-endosulfan in water by gas chromatography–electron-capture detection  

Microsoft Academic Search

Water contamination due to the wide variety of pesticides used in agriculture practices is a global environmental pollution problem. The 98\\/83\\/European Directive requires to measure residues of pesticides at a target concentration of 1.0 ?g\\/l in surface water and 0.1 ?g\\/l in drinking water. In order to reach the level of detection required, efficient extraction techniques are required. Although solid-phase

M. C López-Blanco; B Reboreda-Rodr??guez; B Cancho-Grande; J Simal-Gándara

2002-01-01

152

Clean-up of aqueous acetone vegetable extracts by solid-matrix partition for pyrethroid residue determination by gas chromatography—electron-capture detection  

Microsoft Academic Search

Disposable, ready-to-use cartridges filled with macroporous diatomaceous material are used to carry out a partition clean-up that, in a single step, is capable of transferring pesticide residues from aqueous acetone extracts into light petroleum-dichloromethane (75:25, v\\/v). This procedure takes the place of some functions (such as separatory-funnel partition, drying over anhydrous sodium sulphate and partial adsorption clean-up) usually performed by

Alfonso Di Muccio; Danilo Attard Barbini; Tiziana Generali; Patrizia Pelosi; Antonella Ausili; Fabio Vergori; Ivano Camoni

1997-01-01

153

Ionic liquid-mediated molecularly imprinted solid-phase extraction coupled with gas chromatography-electron capture detector for rapid screening of dicofol in vegetables.  

PubMed

New ionic liquid-mediated molecularly imprinted polymers (IL-MIPs) were prepared by precipitation polymerization using 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM(+)PF6(-)) as the auxiliary solvent, ?-chloro-DDT as the dummy template, and they were successfully applied as the sorbents of solid-phase extraction (SPE) for rapid screening of dicofol from cabbage, tomato, and carrot samples. The IL-MIPs were characterized by FTIR, FE-SEM, static adsorption and chromatographic evaluation, and the results revealed that the IL-MIPs had higher adsorption capacity and selectivity to dicofol in aqueous solution than that of ionic liquid-mediated non-imprinted polymers (IL-NIPs) and non-imprinted polymers (NIPs). Under the optimized conditions, the IL-MIPs-SPE-GC method offered good linearity (0.4-40.0ngg(-1), r(2)=0.9995) and the average recoveries of dicofol at three spiked levels were in a range of 84.6-104.1% (n=3) with RSD?7.6%. The proposed method obviously improved the selectivity and purification effect, and eliminated the effect of template leakage on dicofol quantitative analysis. PMID:23932224

Yan, Hongyuan; Sun, Ning; Han, Yehong; Yang, Chen; Wang, Mingyu; Wu, Ruijun

2013-09-13

154

Detection and quantitation of fatty acid acyl conjugates of triamcinolone acetonide via gas chromatography–electron-capture negative-ion mass spectrometry  

Microsoft Academic Search

The inherent electron-capture properties of triamcinolone acetonide (TAA) fatty acid conjugates were exploited for development of a GC–MS technique for quantitation of C21 long-chain fatty esters of TAA synthesized in BEAS-2B cells, an immortalized airway epithelium cell line. TAA esters extracted from BEAS-2B cells were purified and detected via selected ion monitoring of the molecular anions generated from the TAA

Walter C Hubbard; Andrew E Blum; Carol A Bickel; Nicola M Heller; Robert P Schleimer

2003-01-01

155

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

Microsoft Academic Search

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

1997-01-01

156

Impacts of future Indian greenhouse gas emission scenarios on projected climate change parameters deduced from MAGICC model  

Microsoft Academic Search

The MAGICC (Model for the Assessment of Greenhouse gas Induced Climate Change) model simulation has been carried out for the 2000–2100 period to investigate the impacts of future Indian greenhouse\\u000a gas emission scenarios on the atmospheric concentrations of carbon dioxide, methane and nitrous oxide besides other parameters\\u000a like radiative forcing and temperature. For this purpose, the default global GHG (Greenhouse

Mukti Sharma; Chhemendra Sharma; Abdul Qaiyum

2012-01-01

157

Mortality and greenhouse gas impacts of biomass and petroleum energy futures in Africa.  

PubMed

We analyzed the mortality impacts and greenhouse gas (GHG) emissions produced by household energy use in Africa. Under a business-as-usual (BAU) scenario, household indoor air pollution will cause an estimated 9.8 million premature deaths by the year 2030. Gradual and rapid transitions to charcoal would delay 1.0 million and 2.8 million deaths, respectively; similar transitions to petroleum fuels would delay 1.3 million and 3.7 million deaths. Cumulative BAU GHG emissions will be 6.7 billion tons of carbon by 2050, which is 5.6% of Africa's total emissions. Large shifts to the use of fossil fuels would reduce GHG emissions by 1 to 10%. Charcoal-intensive future scenarios using current practices increase emissions by 140 to 190%; the increase can be reduced to 5 to 36% using currently available technologies for sustainable production or potentially reduced even more with investment in technological innovation. PMID:15802601

Bailis, Robert; Ezzati, Majid; Kammen, Daniel M

2005-04-01

158

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

SciTech Connect

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)

Al-Qurashi, Khalid; Boehman, Andre L. [The EMS Energy Institute, The Pennsylvania State University, 405 Academic Activities Bldg., University Park, PA 16802 (United States)

2008-12-15

159

Mortality and Greenhouse Gas Impacts of Biomass and Petroleum Energy Futures in Africa  

NASA Astrophysics Data System (ADS)

We analyzed the mortality impacts and greenhouse gas (GHG) emissions produced by household energy use in Africa. Under a business-as-usual (BAU) scenario, household indoor air pollution will cause an estimated 9.8 million premature deaths by the year 2030. Gradual and rapid transitions to charcoal would delay 1.0 million and 2.8 million deaths, respectively; similar transitions to petroleum fuels would delay 1.3 million and 3.7 million deaths. Cumulative BAU GHG emissions will be 6.7 billion tons of carbon by 2050, which is 5.6% of Africa's total emissions. Large shifts to the use of fossil fuels would reduce GHG emissions by 1 to 10%. Charcoal-intensive future scenarios using current practices increase emissions by 140 to 190%; the increase can be reduced to 5 to 36% using currently available technologies for sustainable production or potentially reduced even more with investment in technological innovation.

Bailis, Robert; Ezzati, Majid; Kammen, Daniel M.

2005-04-01

160

Inelastic scattering in ocean water and its impact on trace gas retrievals from satellite data  

NASA Astrophysics Data System (ADS)

Over clear ocean waters, UV/Vis. photons scattered within the water body contribute significantly to the upwelling flux. In addition to elastic scattering, inelastic Vibrational Raman Scattering (VRS) by liquid water is also playing a role and can have a strong impact on the spectral distribution of the outgoing radiance. Under clear-sky conditions, VRS has an influence on trace gas retrievals from space-borne measurements of the backscattered radiance such as from e.g. GOME or SCIAMACHY. The effect is particularly important for geo-locations with small solar zenith angles and over waters with low chlorophyll concentration. In this study, a simple ocean reflectance model (Sathyendranath, 1998) accounting for VRS has been incorporated into a radiative transfer model. The model has been validated by comparison with measurements from a swimming-pool experiment dedicated to detect the effect of scattering within water on the outgoing radiation and also with selected data sets from GOME. The comparisons show good agreement between experimental and model data and highlight the important role of VRS. To evaluate the impact of VRS on trace gas retrieval, a sensitivity study was performed on synthetic data. If VRS is neglected in the data analysis, errors of more than 30% are introduced for the slant column (SC) of \\chem{BrO} over clear ocean scenarios. Exemplarily DOAS retrievals of \\chem{BrO} from real GOME measurements including and excluding a VRS compensation led to comparable results as in the sensitivity study, but with somewhat smaller differences between the two analyses. The results of this work suggest, that DOAS retrievals of atmospheric trace species from measurements of nadir viewing space-borne instruments have to take VRS scattering into account over waters with low chlorophyll concentrations, and that a simple correction term is enough to reduce the errors to an acceptable level.

Vountas, M.; Dinter, T.; Richter, A.; Wittrock, F.; Burrows, J. P.

161

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

SciTech Connect

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.

Maguire, J.; Burch, J.

2013-08-01

162

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

PubMed

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

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

2002-09-01

163

ASSESSMENT OF THE IMPACT OF TOA PARTITIONING ON DWPF MELTER OFF-GAS FLAMMABILITY  

SciTech Connect

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.

Daniel, G.

2013-06-18

164

Chondrule Fine-Grained Mantle Formation by Hypervelocity Impact of Chondrules with a Dusty Gas  

NASA Astrophysics Data System (ADS)

At some stage during the chondrule (and refractory inclusion) formation process, many of these objects accreted fine-grained mantles of dust. Observations suggest that the mantle thickness is directly proportional to the chondrule-core radius. Following the proposal of H. C. Connolly, Jr., and S. G. Love (1998, Science280, 62-67), we demonstrate numerically how this effect can be produced by the hypersonic interaction between a chondrule and a mixture of gas and dust. This result is of relevance to the shock and jet models of chondrule formation, and places limits on both models. In particular, we use this result to constrain our version of the jet theory of chondrule formation, where chondrules are formed at the base of a bipolar solar jet and then ejected to the outer regions of a magnetically confined solar nebula, where they impact at hypersonic speeds into the nebula. We find that the observed linear correlation between mantle thickness and chondrule-core radius requires a dust-to-gas mass ratio of approximately 0.5-1.0, provided that the dust-chondrule sticking coefficient, Q, was in the range 0.5-1.0. We suggest that the settling of dust ejected from the jet could produce such high ratios in the inner regions of the nebula. Another constraint on the chondrule formation process is the observed structure of fine-grained rims around igneous rims, but not the other way around. We argue that this observation can be readily explained by the jet model, but poses a challenge for the shock model. As a consequence of this study, we show that the standard drag coefficient for a sphere moving through rarefied gas is approximately 70% of the physically correct value. We also derive a simple form for the drag coefficient which describes the interaction between dust grains and a macroscopic sphere.

Liffman, Kurt; Toscano, Maurizio

2000-01-01

165

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

NASA Technical Reports Server (NTRS)

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".

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

2010-01-01

166

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

PubMed Central

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.

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

2013-01-01

167

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)

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.

Jones, J. A.

1983-01-01

168

The impact of using biodiesel\\/marine gas oil blends on exhaust emissions from a stationary diesel engine  

Microsoft Academic Search

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

G. Karavalakis; E. Tzirakis; L. Mattheou; S. Stournas; F. Zannikos; D. Karonis

2008-01-01

169

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

Federal Register 2010, 2011, 2012, 2013

...Environmental Impact Statement for the Oil and Gas Management Plan at Big South Fork National River and Recreation Area and Obed Wild and...CFR 1506.6. FOR FURTHER INFORMATION CONTACT: Tom Blount, Big South Fork National River [[Page 42762

2012-07-20

170

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

171

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

PubMed

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

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

2014-05-01

172

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...

173

Final Environmental Impact Statement for Proposed Oil and Gas Lease Sales 94, 92, and 102. Gulf of Mexico OCS Region.  

National Technical Information Service (NTIS)

This EIS is a description of the environmental aspects and impacts of oil and gas activities resulting from these lease sales or the states bordering the Gulf of Mexico. It provides a description of the area, affected environment, and environmental conseq...

1984-01-01

174

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

Federal Register 2010, 2011, 2012, 2013

...d) of natural gas to National Grid's...along its existing pipeline system in Pennsylvania...incremental natural gas supply to National...participate in NEPA analysis. While the conclusions...26-inch-diameter pipeline to deliver natural gas from...

2013-10-11

175

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

SciTech Connect

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.

Amy Childers

2011-03-30

176

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

SciTech Connect

This analysis examines the relationship between energy demand and residential building attributes, demographic characteristics, and behavioral variables using the U.S. Department of Energy’s Residential Energy Consumption Survey 2005 microdata. This study investigates the applicability of the smooth backfitting estimator to statistical analysis of residential energy consumption via nonparametric regression. The methodology utilized in the study extends nonparametric additive regression via local linear smooth backfitting to categorical variables. The conventional methods used for analyzing residential energy consumption are econometric modeling and engineering simulations. This study suggests an econometric approach that can be utilized in combination with simulation results. A common weakness of previously used econometric models is a very high likelihood that any suggested parametric relationships will be misspecified. Nonparametric modeling does not have this drawback. Its flexibility allows for uncovering more complex relationships between energy use and the explanatory variables than can possibly be achieved by parametric models. Traditionally, building simulation models overestimated the effects of energy efficiency measures when compared to actual "as-built" observed savings. While focusing on technical efficiency, they do not account for behavioral or market effects. The magnitude of behavioral or market effects may have a substantial influence on the final energy savings resulting from implementation of various energy conservation measures and programs. Moreover, variability in behavioral aspects and user characteristics appears to have a significant impact on total energy consumption. Inaccurate estimates of energy consumption and potential savings also impact investment decisions. The existing modeling literature, whether it relies on parametric specifications or engineering simulation, does not accommodate inclusion of a behavioral component. This 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.

Livingston, Olga V.; Cort, Katherine A.

2011-03-03

177

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

SciTech Connect

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.

Sutton, A.J.; Elias, T. [Minerals Management Service, Menlo Park, CA (United States); Navarrete, R. [Geological Survey, Hawaii National Park, HI (United States). Hawaiian Volcano Observatory

1994-12-31

178

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

SciTech Connect

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.

Daniel, W. E.

2013-02-13

179

Quantitative fluid inclusion gas analysis of airburst, nuclear, impact and fulgurite glasses.  

SciTech Connect

We present quantitative fluid inclusion gas analysis on a suite of violently-formed glasses. We used the incremental crush mass spectrometry method (Norman & Blamey, 2001) to analyze eight pieces of Libyan Desert Glass (LDG). As potential analogues we also analyzed trinitite, three impact crater glasses, and three fulgurites. The 'clear' LDG has the lowest CO{sub 2} content and O{sub 2}/Ar ratios are two orders of magnitude lower than atmospheric. The 'foamy' glass samples have heterogeneous CO{sub 2} contents and O{sub 2}/Ar ratios. N{sub 2}/Ar ratios are similar to atmospheric (83.6). H{sub 2} and He are elevated but it is difficult to confirm whether they are of terrestrial or meteoritic origin. Combustion cannot account for oxygen depletion that matches the amount of CO{sub 2} produced. An alternative mechanism is required that removes oxygen without producing CO{sub 2}. Trinitite has exceedingly high CO{sub 2} which we attribute to carbonate breakdown of the caliche at ground zero. The O{sub 2}/Ar ratio for trinitite is lower than atmospheric but higher than all LDG samples. N{sub 2}/Ar ratios closely match atmospheric. Samples from Lonar, Henbury and Aouelloul impact craters have atmospheric N{sub 2}/Ar ratios. O{sub 2}/Ar ratios at Lonar and Henbury are 9.5 to 9.9 whereas the O{sub 2}/Ar ratio is 0.1 for the Aouelloul sample. In most fulgurites the N{sub 2}/Ar ratio is higher than atmospheric, possibly due to interference from CO. Oxygen ranges from 1.3 to 19.3%. Gas signatures of LDG inclusions neither match those from the craters, trinitite nor fulgurites. It is difficult to explain both the observed depletion of oxygen in the LDG and a CO{sub 2} level that is lower than it would be if the CO{sub 2} were simply a product of hydrocarbon combustion in air. One possible mechanism for oxygen depletion is that as air turbulently mixed with a hot jet of vaporized asteroid from an airburst and expanded, the atmospheric oxygen reacted with the metal vapor to form metal oxides that condensed. This observation is compatible with the model of Boslough & Crawford (2008) who suggest that an airburst incinerates organic materials over a large area, melting surface materials that then quench to form glass. Bubbles would contain a mixture of pre-existing atmosphere with combustion products from organic material and products of the reaction between vaporized cosmic materials (including metals) and terrestrial surface and atmosphere.

Parnell, John (University of Aberdeen, Aberdeen, UK); Newsom, Horton E. (University of New Mexico, Albuquerque, NM); Blamey, Nigel J. F. (New Mexico Tech, Socorro, NM); Boslough, Mark Bruce Elrick

2010-10-01

180

Impact of chemically amended pig slurry on greenhouse gas emissions, soil properties and leachate.  

PubMed

The effectiveness of chemical amendment of pig slurry to ameliorate phosphorus (P) losses in runoff is well studied, but research mainly has concentrated only on the runoff pathway. The aims of this study were to investigate changes to leachate nutrient losses, soil properties and greenhouse gas (GHG) emissions due to the chemical amendment of pig slurry spread at 19 kg total phosphorus (TP), 90 kg total nitrogen (TN), and 180 kg total carbon (TC) ha(-1). The amendments examined were: (1) commercial grade liquid alum (8% Al2O3) applied at a rate of 0.88:1 [Al:TP], (2) commercial-grade liquid ferric chloride (38% FeCl3) applied at a rate of 0.89:1 [Fe:TP] and (3) commercial-grade liquid poly-aluminium chloride (PAC) (10% Al2O3) applied at a rate of 0.72:1 [Al:TP]. Columns filled with sieved soil were incubated for 8 mo at 10 °C and were leached with 160 mL (19 mm) distilled water wk(-1). All amendments reduced the Morgan's phosphorus and water extractable P content of the soil to that of the soil-only treatment, indicating that they have the ability to reduce P loss in leachate following slurry application. There were no significant differences between treatments for nitrogen (N) or carbon (C) in leachate or soil, indicating no deleterious impact on reactive N emissions or soil C cycling. Chemical amendment posed no significant change to GHG emissions from pig slurry, and in the cases of alum and PAC, reduced cumulative N2O and CO2 losses. Chemical amendment of land applied pig slurry can reduce P in runoff without any negative impact on nutrient leaching and GHG emissions. Future work must be conducted to ascertain if more significant reductions in GHG emissions are possible with chemical amendments. PMID:23850764

O' Flynn, Cornelius J; Healy, Mark G; Lanigan, Gary J; Troy, Shane M; Somers, Cathal; Fenton, Owen

2013-10-15

181

The Spatial and Temporal Consumptive Water Use Impacts of Rapid Shale Gas Development and Use in Texas  

NASA Astrophysics Data System (ADS)

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) mining and natural gas production in Texas were also estimated, and water consumption was aggregated by river basin for spatial resolution. Temporal results indicated that the development of shale gas resources during the episode led to a net reduction in consumptive water use in Texas but that a lag time existed before the water use in natural gas production regions was offset by changes in the electricity generation and lignite mining sectors. The water impact on specific river basins in production regions was varied. Some river basins had sufficient changes in coal-fired power plant generation to offset increased water use in shale gas production and for cooling at natural-gas fired power plants, while others did not. Thus, some areas have likely experienced increased water use due to shale gas production despite overall reductions in life-cycle consumptive water use in the state. The largest consumptive water use increase for a river basin, however, was less than 1% of its total water consumption.

Pacsi, A. P.; Allen, D.

2013-12-01

182

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

183

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

PubMed

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

Reynolds, Conor C O; Kandlikar, Milind

2008-08-15

184

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

SciTech Connect

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.

Tegen, S.

2005-08-01

185

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

SciTech Connect

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.

Tegen, S.

2006-05-01

186

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

PubMed

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

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

2009-11-01

187

Impact of policy on greenhouse gas emissions and economics of biodiesel production.  

PubMed

As an alternative transportation fuel to petrodiesel, biodiesel has been promoted within national energy portfolio targets across the world. Early estimations of low lifecycle greenhouse gas (GHG) emissions of biodiesel were a driver behind extensive government support in the form of financial incentives for the industry. However, studies consistently report a high degree of uncertainty in these emissions estimates, raising questions concerning the carbon benefits of biodiesel. Furthermore, the implications of feedstock blending on GHG emissions uncertainty have not been explicitly addressed despite broad practice by the industry to meet fuel quality standards and to control costs. This work investigated the impact of feedstock blending on the characteristics of biodiesel by using a chance-constrained (CC) blend optimization method. The objective of the optimization is minimization of feedstock costs subject to fuel standards and emissions constraints. Results indicate that blending can be used to manage GHG emissions uncertainty characteristics of biodiesel, and to achieve cost reductions through feedstock diversification. Simulations suggest that emissions control policies that restrict the use of certain feedstocks based on their GHG estimates overlook blending practices and benefits, increasing the cost of biodiesel. In contrast, emissions control policies which recognize the multifeedstock nature of biodiesel provide producers with feedstock selection flexibility, enabling them to manage their blend portfolios cost effectively, potentially without compromising fuel quality or emissions reductions. PMID:24828402

Olivetti, Elsa; Gül?en, Ece; Malça, João; Castanheira, Erica; Freire, Fausto; Dias, Luis; Kirchain, Randolph

2014-07-01

188

Multivariate statistical analysis of impacts of underground gas storage caverns on groundwater chemistry  

NASA Astrophysics Data System (ADS)

Multivariate statistical approaches were used to investigate the anthropogenic impacts of underground gas storage caverns on ground water quality. The selected case study was LPG underground storage caverns, which is situated in southeast Korea. The highly alkaline ground waters at this study area are an artificial analogue for the repository system. The alkaline groundwater plume will interact with the rock around the repository and may change the mineralogical and transport properties of the rock. This research describes the uses of multivatiate statistical analysis to trace ground water evolution around underground storage system. Correspondence analysis (CA) were applied for the statistical exploration of the obtained data. In addition, multivariate correlation relationships between geochemical speciation results were derived using principal component analysis (PCA). As preliminary study, the CA allowed the interpretation of both samples sites and variables in the same vector space. The PCA showed the change of mineral phase when anthropogenic effects imposed on ground water. In conclusion, the PCA results from this study where geochemical environment has been altered severely indicate that enhanced pH can induce calcite precipitation and the simultaneous increase in Al concentration with elevated alkalinity must be considered.

Lee, J.; Kim, J.; Chang, H.

2001-12-01

189

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

190

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

SciTech Connect

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.

Reagan, D.P.; Silva del Poso, X. [Woodward-Clyde Consultants, Denver, CO (United States)]|[Sociedad Entomologica Ecuatoriana, Quito (Ecuador)

1995-06-01

191

The Impact of a Lower Sea Ice Extent on Arctic Greenhouse Gas Exchange  

NASA Astrophysics Data System (ADS)

Arctic sea ice extent hit a new record low in September 2012, when it fell to a level about two times lower than the 1979-2000 average. Record low sea ice extents such as these are often hailed as an obvious example of the impact of climate change on the Arctic. Less obvious, however, are the further implications of a lower sea ice extent on Arctic greenhouse gas exchange. For example, a reduction in sea ice, in consort with a lower snow cover, has been connected to higher surface temperatures in the terrestrial part of the Arctic (Screen et al., 2012). These higher temperatures and longer growing seasons have the potential to alter the CO2 balance of Arctic tundra through enhanced photosynthesis and respiration, as well as the magnitude of methane emissions. In fact, large changes are already observed in terrestrial ecosystems (Post et al., 2009), and concerns have been raised of large releases of carbon through permafrost thaw (Schuur et al., 2011). While these changes in the greenhouse gas balance of the terrestrial Arctic are described in numerous studies, a connection with a decline in sea ice extent is nonetheless seldom made. In addition to these changes on land, a lower sea ice extent also has a direct effect on the exchange of greenhouse gases between the ocean and the atmosphere. For example, due to sea ice retreat, more ocean surface remains in contact with the atmosphere, and this has been suggested to increase the oceanic uptake of CO2 (Bates et al., 2006). However, the sustainability of this increased uptake is uncertain (Cai et al., 2010), and carbon fluxes related directly to the sea ice itself add much uncertainty to the oceanic uptake of CO2 (Nomura et al., 2006; Rysgaard et al., 2007). Furthermore, significant emissions of methane from the Arctic Ocean have been observed (Kort et al., 2012; Shakhova et al., 2010), but the consequence of a lower sea ice extent thereon is still unclear. Overall, the decline in sea ice that has been seen in recent years has the potential to influence greenhouse gas exchange across terrestrial ecosystems and the Arctic Ocean, but the overall impact remains unclear. In this study, we therefore try to reduce this uncertainty by addressing the influence of the decline in sea ice extent on all affected greenhouse gas fluxes in the high latitudes. Also, we will address the need for more research, on the ocean and on the land, to understand the impact of a lower sea ice extent on Arctic greenhouse gas exchange. References: Bates, N. R., Moran, S. B., Hansell, D. A. and Mathis, J. T.: An increasing CO2 sink in the Arctic Ocean due to sea-ice loss, Geophys. Res. Lett., 33, L23609, doi:10.1029/2006GL027028, 2006. Cai, W.-J., Chen, L., Chen, B., Gao, Z., Lee, S. H., Chen, J., Pierrot, D., Sullivan, K., Wang, Y., Hu, X., Huang, W.-J., et al.: Decrease in the CO2 Uptake Capacity in an Ice-Free Arctic Ocean Basin, Science, 329(5991), 556-559, doi:10.1126/science.1189338, 2010. Kort, E. A., Wofsy, S. C., Daube, B. C., Diao, M., Elkins, J. W., Gao, R. S., Hintsa, E. J., Hurst, D. F., Jimenez, R., Moore, F. L., Spackman, J. R., et al.: Atmospheric observations of Arctic Ocean methane emissions up to 82 degrees north, Nature Geosci., 5(5), 318-321, doi:10.1038/NGEO1452, 2012. Nomura, D., Yoshikawa-Inoue, H. and Toyota, T.: The effect of sea-ice growth on air-sea CO2 flux in a tank experiment, vol. 58, pp. 418-426. 2006. Post, E., Forchhammer, M. C., Bret-Harte, M. S., Callaghan, T. V., Christensen, T. R., Elberling, B., Fox, A. D., Gilg, O., Hik, D. S., Høye, T. T., Ims, R. A., et al.: Ecological Dynamics Across the Arctic Associated with Recent Climate Change, Science, 325(5946), 1355-1358, doi:10.1126/science.1173113, 2009. Rysgaard, S., Glud, R. N., Sejr, M. K., Bendtsen, J. and Christensen, P. B.: Inorganic carbon transport during sea ice growth and decay: A carbon pump in polar seas, J. Geophys. Res., 112, C03016, doi:10.1029/2006JC003572, 2007. Schuur, E. A. G., Abbott, B. and Network, P. C.: High risk of permafrost thaw, Nature, 480(7375), 32-33, 2011. Screen, J. A., Deser, C. and

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

2013-04-01

192

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

SciTech Connect

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.

Wang, M.Q.

1997-05-20

193

Impact  

NASA Technical Reports Server (NTRS)

Impact, emergency escape and crash survival protection are studied. Accleration, the G system of units, data interpretation, and human tolerance limits are summarized, along with physiological and biochemical response to impact. Biomechanical factors of impact are also cited.

Snyder, R. G.

1973-01-01

194

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

NASA Astrophysics Data System (ADS)

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 from the ICP use them to calculate the GHG emissions from the ICP. Energy outputs (as refined liquid fuel) range from 1.2 to 1.6 times the total primary energy inputs. Well-to-tank greenhouse gas emissions range from 30.6 to 37.1 gCeq./MJ of final fuel delivered, 21 to 47% larger than those from conventionally produced petroleum-based fuels.

Brandt, Adam Robert

195

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

SciTech Connect

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.

Daniels, G.R.

1994-01-01

196

Simulation of the indirect impact that the 11-year solar cycle has on the gas composition of the atmosphere  

Microsoft Academic Search

An interactive three-dimensional chemistry-climate model combining models of the gas composition and general circulation of\\u000a the lower and middle atmosphere is used to study the impact of changes in extra-atmospheric solar radiative fluxes induced\\u000a by solar activity on the stratospheric heating and subsequent temperature and ozone variations in the stratosphere and troposphere.\\u000a The results have shown that a change in

S. P. Smyshlyaev; V. Ya. Galin; E. M. Atlaskin; P. A. Blakitnaya

2010-01-01

197

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

EIA Publications

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.

John J. Conti

2007-01-11

198

Impacts of Flue Gas Impurities in Sequestered CO2 on Groundwater Sources: A Process Analysis and Implications for Risk Management  

Microsoft Academic Search

This study analyzed the potential impacts of acid gases and mercury vapor in the separated CO2 stream from monoethanolamine (MEA) absorption on groundwater aquifers in the case of the CO2 leakage from its storage sites based on published information. When a wet flue gas desulfurization (FGD) system achieves 95% SO2 removal, up to ~2,400 ppmw SO2 could be included in

Joo-Youp Lee; Tim C. Keener; Y. Jeffery Yang

199

The economic impact of shale gas extraction: A review of existing studies  

Microsoft Academic Search

Recent advances in drilling technology have allowed for the profitable extraction of natural gas from deep underground shale rock formations. Several reports sponsored by the gas industry have estimated the economic effects of the shale gas extraction on incomes, employment, and tax revenues. None of these reports has been published in an economics journal and therefore have not been subjected

Thomas C. Kinnaman

2011-01-01

200

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

Microsoft Academic Search

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.

Sulfredge; Charles David

2007-01-01

201

78 FR 26354 - Transcontinental Gas Pipeline Company, LLC; Notice of Intent to Prepare an Environmental Impact...  

Federal Register 2010, 2011, 2012, 2013

...Transcontinental Gas Pipeline Company, LLC (Transco...dekatherms per day of natural gas into the New York City...a 3.2-mile-long pipeline in Queens and Kings Counties...three existing natural gas- fired reciprocating...process is to focus the analysis in the EIS on...

2013-05-06

202

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

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

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

2006-02-10

203

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

PubMed Central

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.

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

2013-01-01

204

Quantitation of opioids in whole blood by electron impact-gas chromatography-mass spectrometry.  

PubMed

Opioids are frequently encountered in Forensic Toxicology casework. A PubMed literature search was conducted to find a method using electron impact-gas chromatography-mass spectrometry to examine whole blood specimens. A previously published method was identified, and an updated version was provided by the State of North Carolina Office of the Chief Medical Examiner. This procedure was used as a starting point for development and validation of a refined procedure to be used in the Palm Beach County Sheriff's Office Forensic Toxicology laboratory for routine analysis of antemortem forensic toxicology case samples. Materials and instrumentation common to most forensic toxicology laboratories were utilized while obtaining detection limits from 1 to 10 ng/mL and quantitation limits of 2.5 to 10 ng/mL using 1 mL of whole blood. Target compounds were chosen based on applicability to the method as well as availability and common use in the United States and include dihydrocodeine, codeine, morphine, hydrocodone, 6-monoacetylmorphine, hydromorphone, oxycodone, and oxymorphone. Each analyte demonstrated two zero-order linear ranges (r(2) > 0.990) over the concentrations evaluated (from 2.5 to 500 ng/mL). The coefficient of variation of replicate analyses was less than 12%. Quantitative accuracy was within ± 27% at 2.5 ng/mL, ± 11% at 10 ng/mL, and ± 8% at 50 ng/mL. The validated method provides a more sensitive procedure for the quantitation of common opioids in blood using standard laboratory equipment and a small amount of sample. PMID:21396229

Tiscione, Nicholas B; Shan, Xiaoqin; Alford, Ilene; Yeatman, Dustin Tate

2011-03-01

205

Impact of Cogeneration on Gas Use in the Industrial and Electric Utility Sectors.  

National Technical Information Service (NTIS)

The primary objective of the report is to examine the impact of industrial sector cogeneration on fuel use in the combined industrial and electric utility sectors. To illustrate the range of uncertainty in cogeneration estimates, the impact is assessed un...

B. Venkateshwara S. Y. Salama

1986-01-01

206

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

PubMed

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

Evans, Jeffrey S; Kiesecker, Joseph M

2014-01-01

207

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

PubMed Central

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.

Evans, Jeffrey S.; Kiesecker, Joseph M.

2014-01-01

208

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

SciTech Connect

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.

Jennings, D.M.

1980-01-01

209

Effect of an impact-generated gas cloud on the acceleration of solid ejecta. [meteorites from Mars  

NASA Technical Reports Server (NTRS)

A hypothesis that vaporization of a large amount of volatiles such as H2O and CO2 in the Martian surface by the impact of a large object could have accelerated solid ejecta to earth is examined. A hydrodynamic model is used to approximate a hemispherical gas cloud expanding into an atmosphere and entraining solid ejecta. Account is taken of the target material, the impactor materials, mass vaporized, impact velocity, drag coefficient, and crater sizes. A Martian crater larger than 30 km diam is found to be a necessary remnant of any impact that could have produced the shergottites, nakhlites and Chassigny meteorites which have been found on earth and possess similarities to analyzed Martian rocks.

Vickery, Ann

1986-01-01

210

The Open University planetary impact facility: A compact two-stage light gas gun for all impact angles  

Microsoft Academic Search

For liquid and planetary regolith target studies, requiring a horizontal target plain, a two-stage light gas gun (LGG) was designed by UniSpaceKent and constructed at the Open University. Based on a 4.7mm bore launch facility, supplied by Physics Applications International (PIA), the design provides high mechanical rigidity under varying angles of launch, using an integral small target chamber (200mm diameter)

J. A. M. McDonnell

2006-01-01

211

Legacies from three former manufactured-gas plants: impacts on groundwater quality  

Microsoft Academic Search

.   Groundwater contamination due to accidental releases of mono- and polycyclic aromatic compounds (MAHs and PAHs) from decommissioned\\u000a manufactured-gas plants is an ongoing and litigious problem. The MAHs and PAHs are derived from coal tar, which was a by-product\\u000a of the gas-manufacturing process. While originally designed to contain coal tar, the manufactured-gas plant structures that\\u000a remain today have often degraded

Robert H. Abrams; Keith Loague

2000-01-01

212

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

SciTech Connect

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.

Wiser, Ryan; Bolinger, Mark

2004-09-20

213

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

PubMed

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 ?g/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

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

2013-04-01

214

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

215

The impact of moderate-scale explosive eruptions on stratospheric gas injections  

Microsoft Academic Search

Volcanic gases such as SO 2, H 2S, HCl and COS emitted during explosive eruptions significantly affect atmospheric chemistry and therefore the Earth's climate. We have evaluated the dependence of volcanic gas emission into the atmosphere on altitude, latitude, and tectonic setting of volcanoes and on the season in which eruptions occurred. These parameters markedly influence final stratospheric gas loading.

M. M. Halmer; H.-U. Schmincke

2003-01-01

216

78 FR 23554 - Sierrita Gas Pipeline LLC; Supplemental Notice of Intent To Prepare an Environmental Impact...  

Federal Register 2010, 2011, 2012, 2013

...link El Paso Natural Gas Company's \\1\\ existing...the Sasabe-Guaymas Pipeline at the U.S.-Mexico...1\\ El Paso Natural Gas Company is an affiliate...the originally proposed pipeline route eastward to a new...process is to focus the analysis in the EIS on the...

2013-04-19

217

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

Microsoft Academic Search

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

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

2007-01-01

218

Impact of electric power generation on green house gas emissions in Europe: Russia, Greece, Italy and views of the EU power plant supply industry – A critical analysis  

Microsoft Academic Search

This paper analyses the impact of electric power generation on greenhouse gas emissions in Europe (including the Asian part of Russia) with reference to Russia, Greece, Italy, and views of the EU power plant supply industry in respect of the Kyoto protocol. The outlook of power industry development in Russia in the 21st century is first considered and its impact

T. J. Hammons

2006-01-01

219

Impacts from Climate Change and Adaptation Responses on Energy Economy and Greenhouse Gas Emissions in the Toronto-Niagara Region, Canada  

Microsoft Academic Search

Climate change may impact the energy sector directly and indirectly. The objective of this study is to develop a systematic approach for assessing impacts of climate change and adaptation response as well as the growing population on energy economy and greenhouse gas emissions. Such an approach was based on regional energy systems characterization, climate change scenario analysis, vulnerability assessment, energy

Q. G. Lin; G. H. Huang; B. Bass

2011-01-01

220

Final Environmental Impact Statement for Proposed Oil and Gas Lease Sales 104 and 105, Gulf of Mexico OCS (Outer Continental Shelf) Region.  

National Technical Information Service (NTIS)

This EIS (Environmental Impact Statement) is a description of the environmental aspects and impacts of oil and gas activities resulting from these lease sales or the states bordering the Gulf of Mexico. It provides a description of the area, affected envi...

J. A. Christopher J. L. Reinhardt W. T. Johnstone

1985-01-01

221

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

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

222

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

SciTech Connect

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.

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

1983-09-01

223

Electron energy distribution functions and transport coefficients relevant for air plasmas in the troposphere: impact of humidity and gas temperature  

NASA Astrophysics Data System (ADS)

A Boltzmann and Monte Carlo analysis of the electron energy distribution function (EEDF) and transport coefficients for air plasmas is presented for the conditions of the Earth troposphere where some transient luminous events (TLEs) such as blue jets, blue starters and gigantic jets have been observed. According to recent model results (Minschwaner et al 2004 J. Climate 17 1272) supported by the halogen occultation experiment, the relative humidity of the atmospheric air between 0 and 15 km can change between 15% and 100% depending on the altitude investigated and the ground temperature. The latter results cover a region of latitudes between -25°S and +25°N, that is, the Earth tropical region where lightning and TLE activity is quite high. The calculations shown here suggest that the relative humidity has a clear impact on the behaviour of the EEDF and magnitude of the transport coefficients of air plasmas at ground (0 km) and room temperature conditions (293 K). At higher altitudes (11 and 15 km), the influence of the relative humidity is negligible when the values of the gas temperature are assumed to be the 'natural' ones corresponding to those altitudes, that is, ~215 K (at 11 km) and ~198 K (at 15 km). However, it is found that a small enhancement (of maximum 100 K) in the background gas temperature (that could be reasonably associated with the TLE activity) would lead to a remarkable impact of the relative humidity on the EEDF and transport coefficients of air plasmas under the conditions of blue jets, blue starters and gigantic jets at 11 and 15 km. The latter effects are visible for relatively low reduced electric fields (E/N <= 25 Td) that could be controlling the afterglow kinetics of the air plasmas generated by TLEs. However, for much higher fields such as, for instance, 400 Td (representative of the fields in the streamer coronas and lightning leaders), the impact of increasing the relative humidity and gas temperature is only slightly noticeable in the attachment coefficient that can exhibit an increase of up to one order of magnitude at 11 km and 15 km for temperatures of 313 K and 308 K, respectively. Finally, a brief analysis is carried out on the impact of the gas temperature on the diffusion coefficients of neutrals and ions. The present results show quite reasonable agreement with available measurements in dry and moist air.

Gordillo-Vázquez, F. J.; Donkó, Z.

2009-08-01

224

Evaluating the Greenhouse Gas Impacts of National Waste Prevention Activities: The U.S. Experience.  

National Technical Information Service (NTIS)

The U.S. Environmental Protection Agency (EPA) has initiated a Climate and Waste Program aimed at reducing greenhouse gas (GHG) emissions from waste management. The Climate and Waste Program utilizes a three pronged approach: (1) research and technical as...

A. Choate J. R. Freed E. Lee H. Ferland

1997-01-01

225

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

Federal Register 2010, 2011, 2012, 2013

...single well pad rather than just one, as was most common in the past. The improvements in horizontal drilling and hydraulic fracturing technologies to improve the ability to access and recover oil and gas located deep underground from horizons...

2013-04-01

226

On The Impact of the Ideal Gas Assumption to High-Pressure Combustion Phenomena in Engines  

Microsoft Academic Search

The effect of the ideal gas law assumption on auto-ignition and NOx-formation in a rapid compression machine is studied. For both processes the simulations are compared to a reference simulation using a Redlich-Kwong equation-of-state based on the critical properties of all constituents.Auto-ignition is studied for several n-heptane\\/air mixtures and the results show that the ideal gas assumption can impose large

A. Evlampiev; L. M. T. Somers; R. S. G. Baert; L. P. H. de Goey

2007-01-01

227

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

Microsoft Academic Search

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

2004-01-01

228

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

NASA Astrophysics Data System (ADS)

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.

Victor, D. G.

2011-12-01

229

Impact of Fuel Interchangeability on dynamic Instabilities in Gas Turbine Engines  

SciTech Connect

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.

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

2007-03-01

230

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

Federal Register 2010, 2011, 2012, 2013

...Impact Statement for Virgil C. Summer Nuclear Station, Units 2 and...Combined Licenses for Virgil C. Summer Nuclear Station, Units 2 and...Report'' for the Virgil C. Summer Nuclear Station, Units 2...

2011-04-22

231

Impacts of Pending Federal Greenhouse Gas Legislation on the Texas Transportation Sector.  

National Technical Information Service (NTIS)

This 2010 study, funded by the Southwest Region University Transportation Center, assesses current regulatory attempts to mitigate climate change and how such proposed action would impact the Texas transportation sector economically. Social and political ...

J. T. Woodward L. B. Boske

2010-01-01

232

Ion impact induced ionization/fragmentation dynamics of rare gas Dimers  

NASA Astrophysics Data System (ADS)

We have measured the ionization and fragmentation of Helium, Neon and Argon Dimers induced by ion impact and observed two different pathways, the sequential ionization on each atom and the interatomic Cou-lombic decay.

Kim, H.-K.; Titze, J.; Schöffler, M.; Trinter, F.; Waitz, M.; Voigtsberger, J.; Sann, H.; Meckel, M.; Stuck, C.; Lenz, U.; Metz, D.; Jung, A.; Odenweller, M.; Neumann, N.; Ulrich, B.; Costa Fraga, R.; Petridis, N.; Schössler, S.; Ullmann-Pfleger, K.; Grisenti, R.; Czasch, A.; Jagutzki, O.; Schmidt, L.; Jahnke, T.; Schmidt-Böcking, H.; Becht, J.; Gassert, H.; Merabet, H.; Rangama, J.; Zhou, C. L.; Cassimi, A.; Dörner, R.

2014-04-01

233

Tensile and impact properties of candidate alloys for high-temperature gas-cooled reactor applications  

SciTech Connect

The tensile properties of solution-treated Incoloy alloy 800H, Hastelloy-X, Nimonic-86, and Inconel-617 have been determined in the temperature range 20 to 1000/sup 0/C. The strength parameters at temperatures above 700/sup 0/C showed a strong dependence on the strain rate; at low strain rates the deformation was dominated by creep effects, the strain rate and maximum stress being related by the Norton creep equation. The tensile and impact properties of the alloys were also determined after exposure at 700 to 1000/sup 0/C for up to 30 000 h. For Incoloy-800H, the results showed good retention of ductility and impact strength. The nickel-base alloys, in contrast, were found to have low room-temperature impact resistance after long time exposure at 700 to 900/sup 0/C, typical values being 10 to 20 J x cm/sup -2/. In impact tests at the exposure temperature, impact strengths were generally above 50 J x cm/sup -2/. At room temperature, allowances in design must be made for the low impact strength of the nickel-base alloys to ensure against brittle fracture. For example, excessive stresses during cooling of components following shutdown should be avoided.

Bruch, U.; te Heesen, E.; Ennis, F.J.; Schuhmacher, D.

1984-08-01

234

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

PubMed Central

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.

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

2013-01-01

235

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

NASA Astrophysics Data System (ADS)

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.

Lexow, B.; Wickert, M.; Thoma, K.; Sch?Fer, F.; Poelchau, M. H.; Kenkmann, T.

2013-01-01

236

Exploring the Impact of Marcellus Shale Gas on Welding and Related Occupations  

NSDL National Science Digital Library

This teacher's guide presents lessons on Marcellus Shale, which is sedimentary rock containing natural gas reserves. Students will look at how changes in the world affect their career options and choices; in this case looking at the welding occupations that are related to extracting gas from Marcellus Shale deposits. The unit is intended for grade 11 and would take seven to eight 45 minute class periods to complete in full. The material is specifically designed for students in Pennsylvania, but could be adapted for schools in other areas. This document may be downloaded in Microsoft Word file format.

2012-10-16

237

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

SciTech Connect

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.

Blake, D.R.; Rowland, F.S. [Univ. of California, Irvine, CA (United States)

1995-08-18

238

Impact of Phytoplankton-Generated Surfactants on Air-Sea Gas Exchange.  

National Technical Information Service (NTIS)

In a recent series of controlled laboratory-based gas exchange experiments we were able to show that oxygen evasion at the air-liquid interface of clean (Sargasso) seawater could be reduced by as much as 50% in the presence of synthetic surfactants and th...

N. M. Frew J. C. Goldman M. R. Dennett A. S. Johnson

1990-01-01

239

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

PubMed Central

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.

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

2013-01-01

240

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

SciTech Connect

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.

McIntyre, Annie

2010-09-01

241

Impact of mass balance calculations on adsorption capacities in microporous shale gas reservoirs  

Microsoft Academic Search

Determination of the adsorbed reservoir capacity of gas shales by adsorption analyses as done routinely by mass balance maybe in significant error if the effects of pore-size dependent void volume (porosity) is not considered. It is shown here that with increasing pressure, helium, which is invariably used to measure void volume, can access pores that are not available for adsorption

Daniel J. K. Ross; R. Marc Bustin

2007-01-01

242

Forestation of boreal peatlands: Impacts of changing albedo and greenhouse gas fluxes on radiative forcing  

Microsoft Academic Search

We estimated the magnitude of the radiative forcing (RF) due to changes in albedo following the forestation of peatlands, and calculated the net RF by taking into account the changes in both the albedo and the greenhouse gas (GHG) fluxes during one forest rotation. Data on radiation, tree biomass, and soil GHG fluxes were combined with models for canopy cover,

Annalea Lohila; Kari Minkkinen; Jukka Laine; Ilkka Savolainen; Juha-Pekka Tuovinen; Lauri Korhonen; Tuomas Laurila; Hanna Tietäväinen; Ari Laaksonen

2010-01-01

243

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

ERIC Educational Resources Information Center

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…

Copp, James H.

244

Rate impacts and key design elements of gas and electric utility decoupling: a comprehensive review  

SciTech Connect

Opponents of decoupling worry that customers will experience frequent and significant rate increases as a result of its adoption, but a review of 28 natural gas and 17 electric utilities suggests that decoupling adjustments are both refunds to customers as well as charges and tend to be small. (author)

Lesh, Pamela G.

2009-10-15

245

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

SciTech Connect

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.

Moses, C.A.; Bernstein, H. [Southwest Research Inst., San Antonio, TX (United States)] [Southwest Research Inst., San Antonio, TX (United States)

1994-01-01

246

Characterization of the global impact of low temperature gas plasma on vegetative microorganisms  

Microsoft Academic Search

Plasma medicine and also decontamination of bacteria with physical plasmas is a promising new field of life science with huge interest especially for medical applications. Despite numerous successful applications of low temperature gas plasmas in medicine and decontamination, the fundamental nature of the interactions between plasma and microorganisms is to a large extent unknown. A detailed knowledge of these interactions

T. Winter; J. Winter; M. Polak; K. Kusch; U. Mader; R. Sietmann; J. Ehlbeck; K. D. Weltmann; M. Hecker; H. Kusch

2011-01-01

247

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

Microsoft Academic Search

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

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

2011-01-01

248

Environmental Protection Versus Energy Supply Security - The Shale Gas Case and Its Impact on Ecosystem Services  

Microsoft Academic Search

The complexity, interrelation and competition between environmental protection and energy supply security is an emerging problem. Often, State environmental protection concerns and standards are outweighed by a competing interest, such as ensuring energy supply security. This paper discusses the benefits and risks of an ecosystem service approach in connection with shale gas extraction in the United States and the European

Leonie Reins

2012-01-01

249

Impacts of offshore liquid natural gas (LNG) terminals on local fish populations in Mass Bay  

Microsoft Academic Search

This study examines the effect of offshore liquid natural gas (LNG) terminals on local fish populations. Two LNG sites and two control sites in Massachusetts Bay were surveyed using hydroacoustics during June 2009. Each LNG site contains an identical subsurface structure, and is at the center of an 800 m radius zone where fishing is prohibited. Control sites do not

Catherine Caruso; J. Idjadi; K. Lagueux; J. Mandelman

2010-01-01

250

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

SciTech Connect

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.

Reichenauer, Thomas G., E-mail: thomas.reichenauer@ait.ac.at [Health and Environment Department, Environmental Resources and Technologies, AIT - Austrian Institute of Technology GmbH, 2444 Seibersdorf (Austria); Watzinger, Andrea; Riesing, Johann [Health and Environment Department, Environmental Resources and Technologies, AIT - Austrian Institute of Technology GmbH, 2444 Seibersdorf (Austria); Gerzabek, Martin H. [Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Applied Life Sciences, Peter Jordan-Strasse 82, 1190 Vienna (Austria)

2011-05-15

251

Impact of a pulsed supersonic deuterium gas jet on the ELM behaviour in ASDEX Upgrade  

NASA Astrophysics Data System (ADS)

The possibility for pacing of type-I edge localized modes (ELMs) in H-mode plasmas by intermittent gas injection was investigated in ASDEX Upgrade as a possible alternative to, and in comparison with, ELM control by pellets. A Laval nozzle type molecular deuterium injector was used, delivering 1.7 ms long jets with up to about 1020D per pulse at a supersonic flow velocity of 2.2 km s-1. With a repetition rate of 2 Hz and a fast rise time of ap25 µs, comparable to typical ELM rise times, the injector seemed to be well-suited for single ELM trigger tests. When applied to H-mode discharges with a moderate type-I ELM frequency of 40-60 Hz, no prompt (<0.5 ms) ELM triggering could be achieved, in contrast to the experience with pellets. There was, however, clear evidence for a delayed effect in the form of an inverse correlation of the gas pulse amplitude with the time interval between the gas pulse and the next ELM. The apparent lack of prompt ELM triggering seems to be due to a self-blocking of the gas jet by an extremely fast formation of a high density plasma layer in the separatrix vicinity, while the delayed effect may be simply caused by the jet-induced axisymmetric edge profile modification, similar to the delayed ELM cascade observed after a prompt ELM in case of large pellet injection. The delayed trigger effect observed might still be useful for ELM control in future machines, but the related high gas fuelling at elevated pulse frequency could make it unattractive in view of overall plasma performance.

Lang, P. T.; Neuhauser, J.; Bucalossi, J.; Chankin, A.; Coster, D. P.; Drube, R.; Dux, R.; Haas, G.; Horton, L. D.; Kalvin, S.; Kocsis, G.; Maraschek, M.; Mertens, V.; Rohde, V.; Rozhansky, V.; Schneider, R.; Senichenkov, I.; Veselova, I.; Wolfrum, E.; ASDEX Upgrade Team

2005-09-01

252

the Impact of Biogenic Gas on DNAPLs' Migration in Coarse Sand  

NASA Astrophysics Data System (ADS)

Dense Non-Aqueous Phase Liquids (DNAPLs) are major concerns in many common groundwater contaminants. DNAPLs have low solubilities and significant vapor pressures, which allow them to partition into the gas phase of the unsaturated zone. Bioremediation is a promising alternative to traditional technologies at treating DNAPLs because of its noninvasive and cost-effective. A two-dimensional sandbox system was set up for investigating flow and transport of TCE in saturated and unsaturated porous media. Image analysis of multiphase flow in the sandbox by a charge-coupled device (CCD) camera was found to be effective in monitoring the migration of DNAPL and gas bubbles. To simulate the bubbles generated by microbes, the unsaturated medium was developed by injecting air into the cell through sampling needle at the fixed location. In both saturated and unsaturated condition, TCE move downward because of its weight and density and form a pool at the bottom of the cell. In addition, the local dense "lens" of the porous media can make TCE change the path of infiltration. The movement of TCE in the unsaturated cell is slightly slower than its movement on the saturated condition. The gas bubbles hinder the movement of TCE. Some residual TCE are founded in the unsaturated phase of the cell. In the multiphase system, the saturations of DNAPL, gas and water can be estimated by using the light intensity and correlate models. The results show that it is consistent to the observations except that there is relative large error in the beginning of the DNAPL infiltration. However, as long as the experiments carry on, the relative error can decrease to 1%. What's more, the volume amount of infiltration of DNAPL and gas bubbles can also be estimated by light intensity through the cell. It is feasible to use the light transmission method to characterize the movement and spatial distribution of DNAPL in saturated and unsaturated porous media.

Zhang, Y.; Yang, J.; Ye, S.; Wu, J.

2011-12-01

253

Angular momentum coupling and electron-impact excitation cross sections of rare-gas atoms  

Microsoft Academic Search

Electron-impact excitation cross sections for the heavy rare gases are examined in the context of the angular momentum coupling of the final states. Measurements for excitation into n?p5np levels with J=0 are found to vary in a common way for excitation of Ne, Ar, Kr, and Xe.

Tobin Weber; John B. Boffard; Chun C. Lin

2004-01-01

254

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

Microsoft Academic Search

The objective of this study is to assess Indonesia's air quality. This comprised an assessment of Indonesia's air pollution levels and their impact on the development of health and the economics. Estimates are given of concentrations of one of the major pollutants: sulfur dioxide (SO2). Emissions are estimated for Indonesian region, based on energy consumption, derived from the MERGE simulation

A. Susandi

2004-01-01

255

The Distributional Impacts of Economic Instruments to Limit Greenhouse Gas Emissions from Transport  

Microsoft Academic Search

The research reported in this was conducted under the project The Social Impacts of Environmental Taxes: Removing Regressivity, funded by the Joseph Rowntree Foundation under it Programme on Environment and Social Concerns. The project is investigating the social implications of environmental taxes and charges in relation to four environmental issues - the household use of energy, water and transport, and

2004-01-01

256

The Impact of Municipal Solid Waste Management on Greenhouse Gas Emissions in the United States  

Microsoft Academic Search

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

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

2002-01-01

257

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

Microsoft Academic Search

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

C. E. Kirschner; A. Grantz

1990-01-01

258

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

SciTech Connect

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).

Kirschner, C.E. (Geological Survey, Union, WA (United States)); Grantz, A.; Mullen, M.W. (Geological Survey, Menlo Park, CA (United States))

1992-05-01

259

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

SciTech Connect

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 (H{sub 2}S, NH{sub 3}, HCN, AsH{sub 3}, PH{sub 3}, HCl, NaCl, KCl, AS{sub 3}, NH{sub 4}NO{sub 3}, NH{sub 4}OH, KNO{sub 3}, HBr, HF, and HNO{sub 3}) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts; ferrochrome-based high-temperature WGS catalyst (HT-WGS, Shiftmax 120�, Süd-Chemie), low-temperature Cu/ZnO-based WGS catalyst (LT-WGS, Shiftmax 230�, Süd-Chemie), and iron- and cobalt-based Fischer-Trospch synthesis catalysts (Fe-FT & Co-FT, UK-CAER). In this project, TDA Research, Inc. collaborated with a team at the University of Kentucky Center for Applied Energy Research (UK-CAER) led by Dr. Burt Davis. We first conducted a detailed thermodynamic analysis. The three primary mechanisms whereby the contaminants may deactivate the catalyst are condensation, deposition, and reaction. AsH{sub 3}, PH{sub 3}, H{sub 2}S, HCl, NH{sub 3} and HCN were found to have a major impact on the Fe-FT catalyst by producing reaction products, while NaCl, KCl and PH{sub 3} produce trace amounts of deposition products. The impact of the contaminants on the activity, selectivity, and deactivation rates (lifetime) of the catalysts was determined in bench-scale tests. Most of the contaminants appeared to adsorb onto (or react with) the HT- and LT-WGS catalysts were they were co-fed with the syngas: � 4.5 ppmv AsH{sub 3} or 1 ppmv PH{sub 3} in the syngas impacted the selectivity and CO conversion of both catalysts; � H{sub 2}S slowly degraded both WGS catalysts; - A binary mixture of H{sub 2}S (60 ppmv) and NH{sub 3} (38 ppmv) impacted the activity of the LT-WGS catalyst, but not the HT-WGS catalyst � Moderate levels of NH{sub 3} (100 ppmv) or HCN (10 ppmv) had no impact � NaCl or KCl had essentially no effect on the HT-WGS catalyst, but the activity of the LT-WGS catalyst decreased very slowly Long-term experiments on the Co-FT catalyst at 260 and 270 °C showed that all of the contaminants impacted it to some extent with the exception of NaCl and HF. Irrespective of its source (e.g., NH{sub 3}, KNO{sub 3}, or HNO{sub 3}), ammonia suppressed the activity of the Co-FT catalyst to a moderate degree. There was essentially no impact the Fe-FT catalyst when up to 100 ppmw halide compounds (NaCl and KCl), or up to 40 ppmw alkali bicarbonates (NaHCO{sub 3} and KHCO{sub 3}). After testing, BET analysis showed that the surface areas, and pore volumes and diameters of both WGS catalysts decreased during both single and binary H2S and NH3 tests, which was attributed to sintering and pore filling by the impurities. The HT-WGS catalyst was evaluated with XRD after testing in syngas that contained 1 ppmv PH{sub 3}, or 2 ppmv H{sub 2}S, or both H{sub 2}S (60 ppmv) and NH{sub 3} (38 ppmv). The peaks became sharper during testing, which was indicative of crystal growth and sintering, but no new phases were detected. After LT-WGS tests (3-33 ppmv NH{sub 3} and/or 0-88 ppmv H{sub 2}S) there were a few new phases that appeared, including sulfides. The fresh Fe-FT catalyst was nanocrystalline and amorphous. ICP-AA spectroscopy and other methods (e.g., chromatography) were used to analyze for

Gokhan Alptekin

2012-09-30

260

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

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

261

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

PubMed

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

Rahm, Brian G; Riha, Susan J

2014-05-28

262

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

SciTech Connect

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.

Kumagai, Motoki [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); School of Health Sciences, Niigata University, Niigata (Japan); Hara, Ryusuke [Hospital, National Institute of Radiological Sciences, Chiba (Japan); Mori, Shinichiro [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)], E-mail: shinshin@nirs.go.jp; Yanagi, Takeshi [Hospital, National Institute of Radiological Sciences, Chiba (Japan); Asakura, Hiroshi [Accelerator Engineering Corporation, Chiba (Japan); Kishimoto, Riwa; Kato, Hirotoshi; Yamada, Shigeru; Kandatsu, Susumu; Kamada, Tadashi [Hospital, National Institute of Radiological Sciences, Chiba (Japan)

2009-03-15

263

Precompression and desensitization of a high explosive by trapped gas in plate impacts--new measurements  

SciTech Connect

It has long been known that trapped gas between an impactor and high explosive will precompress a layer of the explosive. Most quantitative studies measure the resulting decrease in shock sensitivity. There have been no studies really aimed at measuring the properties of the precompressed layer. Experiments at Los Alamos originally to study release behavior allow the layer to be probed in PBX 9502 (95% TATB, 5% KeI-F 800).

Anderson, W. W. (William W.); Fritz, J. N. (Joseph N.); Kennedy, J. E. (James E.); Shaw, S. M.

2002-01-01

264

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

NASA Astrophysics Data System (ADS)

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.

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

1990-03-01

265

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

PubMed

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

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

2013-10-15

266

The impact of subcontinuum gas conduction on topography measurement sensitivity using heated atomic force microscope cantilevers  

SciTech Connect

Nanometer-scale topographical imaging using heated atomic force microscope (AFM) cantilevers, referred to here as thermal sensing AFM (TSAFM), is a promising technology for high resolution topographical imaging of nanostructured surfaces. Heated AFM cantilevers were developed for high-density data storage, where the heated cantilever tip can form and detect 20 nm indents made in a thermoplastic polymer. The scan height of the cantilever heater platform is typically near 500 nm, but could be made much smaller to improve reading sensitivity. Under atmospheric conditions the continuum models used in previous studies to model the gas phase heat transfer are invalid for the smallest operating heights. The present study uses a molecular model of subcontinuum heat transfer coupled with a finite difference simulation to predict the behavior of a TSAFM system. A direct simulation Monte Carlo model and a kinetic theory based macromodel are separately developed and used to model subcontinuum gas conduction. For the working gas (argon) the simple macromodel is found to be accurate and is used to predict cantilever operation. This systems-level modeling approach for TSAFM operation can aid data interpretation and seeks to improve microcantilever design.

Masters, Nathan D.; Ye Wenjing; King, William P. [Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States)

2005-10-01

267

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

PubMed

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

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

2011-05-01

268

Evaluating 2012 Ozone Impacts of Natural Gas Development in the Haynesville Shale with an Updated Emission Inventory  

NASA Astrophysics Data System (ADS)

The Haynesville Shale, located approximately 10,000-13,000 feet beneath Northeast Texas and Northwest Louisiana contains very large recoverable reserves of natural gas. Development of the Haynesville began in 2008, and since then, more than 3,000 wells have been drilled. The development of natural gas resources in the Haynesville is economically important, but also generates emissions of ozone precursors in a region with several ozone monitors that are close to or exceeding the 2008 National Ambient Air Quality Standard. During 2009, we developed an emission inventory of ozone precursors for projected future Haynesville Shale development from 2009 through 2020. Photochemical modeling with the 2012 emission inventory showed significant ozone impacts within Northeast Texas and Northwest Louisiana as a result of Haynesville emissions, with projected 8-hour ozone design value increases up to 5 ppb at area monitors. The original emission inventory was assembled during spring 2009, early in the development of the Haynesville when available data were limited. Since then, development in the Haynesville has continued, and additional data are now available and were used to refine the development projections and emission inventory through the year 2020. The updated 2012 emission inventory is now based on actual data rather than projections made in 2009. The number of drilling rigs operating in 2012 was lower than projected, but the well count was higher due intensive drilling activity in 2010-2011 that exceeded projections. The updated emission inventory draws on more Haynesville-specific data than the previous inventory. Energy producers currently active in the Haynesville were surveyed and provided information that included well drilling times, equipment used for well construction, production equipment present at typical Haynesville wells, and produced gas composition analyses. Producers provided information on the amount of truck traffic associated with transport of materials, equipment, and personnel to and from wells and the types and activity of non-road equipment operating at well sites. Well production data for 2009 through 2012 from Texas and Louisiana state regulatory agencies was used to update the well decline curve used to project formation-wide gas production. The updated emission inventory was used to quantify 2012 ozone impacts from the Haynesville with the CAMx photochemical grid model. The ozone contribution from truck traffic was determined. We evaluated the effect of the Haynesville on ozone design values in Northeast Texas and Northwest Louisiana as well as on regional ozone. The model projections for ozone were compared to recent trends in observed ozone.

Kemball-Cook, S. R.; Bar-Ilan, A.; Yarwood, G.

2013-12-01

269

The Impact of Farm Machinery Management on the Greenhouse Gas Emissions from Canadian Agriculture  

Microsoft Academic Search

The impact of proposed changes in field operations and land use on fossil fuel consumption on Canadian farms was analyzed using a computer model of the mechanics of farm machinery. The model predicted tractor\\/harvester power needs (kW), implement sizes and work required (kW-h) to complete each field operation on model farms in Canada's four farming regions. These predictions were integrated

J. A. Dyer; R. L. Desjardins

2003-01-01

270

Structural determination of nerve agent markers using gas chromatography mass spectrometry after derivatization with 3-pyridyldiazomethane.  

PubMed

Nerve agents are a class of organophosphorous chemicals that are prohibited under the Chemical Weapons Convention. Their degradation products, phosphonic acids, are analyzed as markers of nerve agent contamination and use. Because the phosphonic acids are non-volatile and very polar, their identification by GC-MS requires a derivatization step prior to analysis. Standard derivatization methods for gas-chromatography electron-impact mass-spectrometry analysis give very similar spectra for many alkyl phosphonic acid isomers, which complicates the identification process. We present a new reagent, 3-pyridyldiazomethane, for preparing picolinyl ester derivatives of alkyl methylphosphonic acids facilitating the determination of their structure by enhancing predictable fragmentation of the O-alkyl chain. This fragmentation is directed by the nitrogen nucleus of the pyridyl moiety that abstracts hydrogen from the O-alkyl chain, inducing radical cleavage of the carbon-carbon bonds and thereby causing extensive fragmentation that can be used for detailed structure elucidation of the O-alkyl moiety. The separability of related isomers was tested by comparing the spectra of the picolinyl esters formed from twelve hexyl methylphosphonic acid isomers. Spectral library matches and principal component analysis showed that the picolinyl esters were more effectively separated than the corresponding trimethylsilyl derivatives used in the standard operating procedures. The suggested method will improve the unambiguous structural determination process for phosphonic acids. PMID:23832937

Nyholm, Jenny Rattfelt; Gustafsson, Tomas; Östin, Anders

2013-07-01

271

A system to damp the free piston oscillations in a two-stage light-gas gun used for hypervelocity impact experiments  

Microsoft Academic Search

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

D. Pavarin; A. Francesconi; F. Angrilli

2004-01-01

272

Chemical effects of low energy electron impact on hydrocarbons in the gas phase. I. Neopentane. [''Simulated'' radiolysis of neopentane; 3. 5-15. 0 eV electrons  

Microsoft Academic Search

The chemical effects induced by impact of low energy electrons of gaseous neopentane were investigated. An original set-up for the irradiation of a flowing gas at low pressure (10⁻²Torr) with 3.5--15.0 eV electrons was used. Electron beam energy definition and current intensity were +- 0.6 eV and 7--15 ..mu..A, respectively. Analysis of the products was performed by gas chromatography. The

R. Derai; P. Nectoux; J. Danon

1976-01-01

273

Use of the Edmonds-Reilly Model to model energy-sector impacts of greenhouse gas emissions control strategies  

SciTech Connect

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.

Barns, D.W.; Edmonds, J.A.; Reilly, J.M.

1992-01-01

274

Impacts of Application of Methane Fermentation Digested Liquid on Green House Gas Emissions and Nitrogen Leaching from Upland Field  

NASA Astrophysics Data System (ADS)

Nitrogen uptake by crops, green-house gas emissions and nitrogen leaching were studied by using monolith lysimeters applied with digested liquid or ammonium sulfate to evaluate the environmental impacts of applications of methane fermentation digested liquid on Andosol upland field. A two-year experiment indicated the percentages of nitrogen uptake, leached nitrogen and nitrous oxide (N2O) emissions to each material-derived nitrogen were 27%, 44% and 0.41% in the digested liquid plot and 32%, 46% and 0.11% in the ammonium sulfate plot. The results show that digested liquid is readily release fertilizer like ammonium sulfate, and nitrogen is leached as easily from the digested liquid as from the ammonium sulfate and the N2O emissions from the digested liquid plot are higher than from the ammonium sulfate plot.

Nakamura, Masato; Fujikawa, Tomonori; Yuyama, Yoshito; Maeda, Morihiro; Yamaoka, Masaru

275

Ion scattering spectroscopy in the impact collision mode (ICISS): Surface structure information from noble gas and alkali-ion scattering  

NASA Astrophysics Data System (ADS)

Low energy (2000 eV) ion scattering spectroscopy in the impact collision mode has been carried out in three modes: primary noble gas ions and detection of ions only (usual ICISS), detection of both ions and neutrals (NICISS) and use of primary alkali ions (ALICISS). The three modes have been compared by in situ measurements at a Pt(111) surface. Usual ICISS suffers from the high neutralization probability of the ions during scattering. This has a hardly predictable influence on the scattering patterns and limits the sensitivity to the first layer. In addition it asks for large primary ion doses which impair the state of the surface. In the case of ALICISS the neutralization is substantially reduced, while in NICISS it plays no role. These two ICISS modes supply a picture of the relative positions of the atom cores in real space making them ideally suited for the determination of surface reconstruction or relaxation.

Niehus, Horst; Comsa, George

1986-04-01

276

Impact of operations at low anode-cathode distance on energy consumption and greenhouse gas emissions at Aluminerie Alouette  

NASA Astrophysics Data System (ADS)

The energy consumption for aluminum production by the Hall-Héroult process has been significantly improved during the last few decades. This has been achieved mainly as a result of improved cell design and suitable process control strategies that have allowed higher cell currents and smaller anode-cathode distance (ACD). Without taking suitable corrective actions, operations at lower ACD conditions can negatively impact aluminum re-oxidation, by-pass current, alumina dissolution and anode effect rates. Superior operational practices are therefore required to maintain acceptably low instability levels along with lower specific energy consumption. This paper discusses anode effect fundamentals and greenhouse gas emissions in relation with industrial cells operating at low ACD at the Aluminerie Alouette plant in Quebec.

Coursol, P.; Coulombe, P.; Gosselin, S.; Lavoie, D.; Simard, J.-M.; Marks, J.; Fardeau, S.

2011-08-01

277

Fuel-cycle greenhouse gas emissions impacts of alternative transportation fuels and advanced vehicle technologies.  

SciTech Connect

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.

Wang, M. Q.

1998-12-16

278

Impact of gas heating on an rf-plasma structure in a microcell at high pressure  

NASA Astrophysics Data System (ADS)

In a micro-plasma confined in a small volume at atmospheric pressure, we may have to consider the influence of the local heating of feed gases on the inner plasma parameters, plasma production rate etc. A capacitively coupled micro-plasma in an axisymmetric two dimensional space is theoretically investigated in Ar driven at 13.56 MHz as a typical example. The governing equation of temperature in a gas phase and on a wall is joined with conventional system equations of electrons, ions and long-lived metastable molecules as well as the potential based on the relaxation continuum (rct) model. We first stress in the micro-plasma at atmospheric pressure that an electron with intermediate energy plays an important role in plasma production through stepwise ionization in the presence of high-density metastable having a low ionization threshold. A new sustaining mechanism in the rf-CCP will be demonstrated. That is, the rf micro-plasma is sustained in the instantaneous anode-phase of the powered electrode. Secondly we bring up the enhancement of the net ionization rate by high energy electrons through the increase of the local reduced field, E(r,t)/N(r), under the appearance of a broad minimum of the number density of the heated neutral gas. In the later part of the talk, we will discuss the historically development of the basic concept, reduced-field, employed in the field of collisional low temperature plasmas.

Makabe, Toshiaki

2012-10-01

279

Characterization of the global impact of low temperature gas plasma on vegetative microorganisms.  

PubMed

Plasma medicine and also decontamination of bacteria with physical plasmas is a promising new field of life science with huge interest especially for medical applications. Despite numerous successful applications of low temperature gas plasmas in medicine and decontamination, the fundamental nature of the interactions between plasma and microorganisms is to a large extent unknown. A detailed knowledge of these interactions is essential for the development of new as well as for the enhancement of established plasma-treatment procedures. In the present work we introduce for the first time a growth chamber system suitable for low temperature gas plasma treatment of bacteria in liquid medium. We have coupled the use of this apparatus to a combined proteomic and transcriptomic analyses to investigate the specific stress response of Bacillus subtilis 168 cells to treatment with argon plasma. The treatment with three different discharge voltages revealed not only effects on growth, but also clear evidence of cellular stress responses. B. subtilis suffered severe cell wall stress, which was made visible also by electron microscopy, DNA damages and oxidative stress as a result of exposure to plasma. These biological findings were supported by the detection of reactive plasma species by OES measurements. PMID:21751354

Winter, Theresa; Winter, Jörn; Polak, Martin; Kusch, Kathrin; Mäder, Ulrike; Sietmann, Rabea; Ehlbeck, Jörg; van Hijum, Sacha; Weltmann, Klaus-Dieter; Hecker, Michael; Kusch, Harald

2011-09-01

280

Impact of Drainage Front Morphology on Gas Diffusion in Unsaturated Porous Media: A Lattice Boltzmann Study  

NASA Astrophysics Data System (ADS)

The effect of a pore-scale phenomenon (flow morphology) on a macroscopic transport property (effective gas diffusion coefficient) is analyzed using the lattice Boltzmann method (LBM). Various flow regimes for two-phase flow in porous media have been defined: stable displacement, capillary fingering, and viscous fingering. The dominance of one regime over another in a porous medium of interest is controlled by the relative magnitudes of gravity, viscous, and capillary forces, which can be quantified with three parameters: Bond number Bo, capillary number Ca, and their difference, Bo-Ca. It has been shown that macroscopic transport properties in porous media are highly dependent on fluid configuration. Since the three flow regimes exhibit very different fluid morphologies, it seems likely that flow regime would have a significant effect on diffusion. In order to investigate the effect, forced drainage from a 2-D porous medium is simulated, and resulting flow patterns are analyzed and compared to the experimental results from the literature. The LBM adequately reproduces expected flow morphologies under a range of applied drainage velocities and gravitational accelerations (i.e., Capillary and Bond numbers). Gas diffusion through the unsaturated domain at various water contents is then simulated for two cases: stable drainage front and a front exhibiting viscous fingering. The macroscopic effective diffusion coefficient as a function of water content is measured and compared for both cases; significant reductions are found in the effective diffusion coefficient in the viscous fingering case relative to the stable displacement case.

Chau, J. F.; Or, D.

2005-12-01

281

Estimation of measurement uncertainty of polychlorinated biphenyls, polycyclic aromatic hydrocarbons and organochlorine pesticides in the atmosphere using gas chromatography-mass spectrometry and gas chromatography-electron capture detector.  

PubMed

Estimation of uncertainty of measurement is a crucial issue to achieve accurate measurement results. When the target has adverse environmental and health effects, accuracy of the results become more important. POPs are the pollutants that have toxic effects and unfortunately, there is a lack of information about uncertainty of the method for determining POPs in air samples. In this work, uncertainty calculations were carried out for PCBs, OCPs, and PAHs in air samples analyzed by using GC-MS and GC-ECD. The main dominant sources for combined uncertainty were calibration curve, recovery and repeatability. The relative uncertainties were found to be in the range of 23-52% for PCBs, 24-59% for OCPs and 23-90% for PAHs. PMID:24369999

Aslan-Sungur, Güler; Gaga, Eftade O; Yenisoy-Karaka?, Serpil

2014-01-17

282

Cellulosic ethanol from municipal solid waste: a case study of the economic, energy, and greenhouse gas impacts in California.  

PubMed

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 between $2.90 and $3.47/gal (mu = $3.13/gal). PMID:19708339

Chester, Mikhail; Martin, Elliot

2009-07-15

283

European greenhouse gas fluxes from land use: the impact of expanding the use of dedicated bioenergy crops.  

NASA Astrophysics Data System (ADS)

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 bioenergy feedstock. This data has been used to quantify the net change in GHG emissions and the quantity of energy produced. We conclude that home grown bioenergy will be a modest contributor to both GHG emission reduction and energy demand.

Hastings, Astley; Böttcher, Hannes; Clifton-Brown, John; Fuchs, Richard; Hillier, Jon; Jones, Ed; Obersteiner, Michael; Pogson, Mark; Richards, Mark; Smith, Pete

2013-04-01

284

The Impacts of a 2-Degree Rise in Global Temperatures upon Gas-Phase Air Pollutants in Europe  

NASA Astrophysics Data System (ADS)

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 then used as a reference for an analysis of future climate scenarios upon European air quality. The future scenarios included two types of emission data for the year 2050: one set of emission data corresponding to a current legislation scenario and another corresponding to a scenario with a maximum feasible reduction in emissions. The future scenarios were run for the time period that corresponds to a 2-degree increase in global temperatures; a time period that varies depending on which global climate model is used. In order to calculate the effect of climate change on emission reduction scenarios, the "climate penalty", the future simulations were compared to a simulation using the same future emissions but with current (2005) climate. Results show that climate change will have consequential impacts with regards to the production and geographical distribution of ozone and nitrogen oxides.

Watson, Laura; Josse, Béatrice; Marecal, Virginie; Lacressonnière, Gwendoline; Vautard, Robert; Gauss, Michael; Engardt, Magnuz; Nyiri, Agnes; Siour, Guillaume

2014-05-01

285

Volcanic gas emissions from Mount Erebus and their impact on the Antarctic environment  

SciTech Connect

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

Zreda-Gostynska, G.; Kyle, P.R. [Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, New Mexico (United States)] [Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, New Mexico (United States); Finnegan, D. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Prestbo, K.M. [Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, New Mexico (United States)] [Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, New Mexico (United States)

1997-07-01

286

Outer continental shelf oil and gas activities in the Gulf of Mexico and their onshore impacts. Gulf of Mexico summary report, October 1984June 1985  

Microsoft Academic Search

This report provide a brief but comprehensive overview of oil and gas activites offshore in the Gulf of Mexico. While the reports focus on the Outer Continental Shelf (OCS) and the onshore impacts of operations in federal waters, information also is included on development in state waters and on how significant national issues affect Gulf Coast States. In addition, this

C. W. Lynch; S. P. Risotto

1985-01-01

287

Single microparticle launching method using two-stage light-gas gun for simulating hypervelocity impacts of micrometeoroids and space debris  

Microsoft Academic Search

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

Nobuaki Kawai; Kenji Tsurui; Sunao Hasegawa; Eiichi Sato

2010-01-01

288

Life cycle greenhouse gas emissions impacts of the adoption of the EU Directive on biofuels in Spain. Effect of the import of raw materials and land use changes  

Microsoft Academic Search

The objective of this paper is to evaluate the greenhouse gas (GHG) emissions impacts of the use of different alternative biofuels in passenger vehicles in Spain in order to meet EU biofuel goals. Different crop production alternatives are analysed, including the possible import of some raw materials. Availability of land for national production of the raw materials is analysed and

Y. Lechon; H. Cabal; R. Sáez

2011-01-01

289

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...

290

Draft Environmental Impact Statement for Proposed Oil and Gas Lease Sales 113/115/116, Gulf of Mexico OCS (Outer Continental Shelf) Region,  

National Technical Information Service (NTIS)

The EIS is a description of the environmental aspects and impacts of oil and gas activities resulting from the lease sale or the states bordering the Gulf of Mexico. It provides a description of the area, affected environment, and environmental consequenc...

R. M. Rouse J. W. Lehman C. L. Vaughan

1987-01-01

291

Water Resource Impacts During Unconventional Shale Gas Development: The Pennsylvania Experience  

NASA Astrophysics Data System (ADS)

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 investigated by state regulators) and the media attention during the fast start in PA may have led to better management practices. Maintaining online databases of observations could similarly drive shale-gas practice to become even more environmentally protective.

Brantley, S. L.; Yoxtheimer, D.; Arjmand, S.; Grieve, P.; Vidic, R.; Abad, J. D.; Simon, C. A.; Pollak, J.

2013-12-01

292

Evaluation of a multiresidue method for pesticides in cereals using supercritical fluid extraction and gas chromatographic detection  

Microsoft Academic Search

Supercritical fluid extraction (SFE) was evaluated to be applied for residue analysis of 22 gas chromatography\\/electron capture detector-nitrogen phosphorus detector (GC\\/ECD-NPD) amenable pesticides in rice, wild rice and wheat. Samples were extracted with supercritical carbon dioxide at 200 atm pressure and 50°C temperature, using methanol as a static modifier. Mean recoveries obtained with the proposed SFE method at two spiking

Antonio Valverde; Ana Aguilera; Mariano Rodriguez; Maria Brotons

2009-01-01

293

A Satellite Formation Due to A Giant Impact: The Effect of the Protoplanet Mass and Its Composition on the Disk Gas Fraction  

NASA Astrophysics Data System (ADS)

It has been thought that the Moon is formed by a giant impact in the late stage of the Earth formation. The impact generates a debris disk around the earth, from which the Moon is accreted. This type of satellite formation is believed to be common in the solar and extra solar systems, such as Pluto and its moon, Charon. Recent study has revealed that the initial gas mass fraction in an impact-generated disk can highly affect the satellite formation process. It also means that a satellite mass depends on the initial disk gas ratio. Machida and Abe (2004) have shown that the higher disk gas ratio creates smaller satellite mass. They have also found out that if evaporation rate exceeds 70%, no satellite can be formed from the disk since solid/liquid materials in the disk fall into the Earth or escape before the disk cooling. Wada et al. (2006) have suggested that strong shocks occur in a gas rich disk, which causes most of the disk material falls into the earth within a few days. Thus, initial disk gas ratio must be taken into account in order to understand the satellite formation process, however, its effect has not been considered carefully yet. In our work, we have investigated the disk gas ratio as a function of protoplanet mass and its material, based on the idea that impact energy and the latent heat of disk material basically define the disk gas ratio. We have performed giant impact simulations of water-icy and rocky protoplanets using Smoothed Particle Hydrodynamics (SPH) method. ANEOS and SESAME equation of states are used. As a result, the disk evaporation is negligible in a Pluto-Chaon mass-size impact, but for an Earth-Moon size, the disk evaporation rate of the water-icy protoplanet can exceed 70%, whereas that of rocky one is about 10-30%. For a 5 Earth mass size system, most of the disk material evaporates in both icy and rocky protoplanet impacts. The result suggests that protoplanet mass and its material also affect the satellite mass. In our presentation, we will also discuss the disk evolution after the debris disk formation, taking into account the disk cooling and hydrodynamic escape.

Nakajima, M.; Genda, H.; Asphaug, E. I.; Ida, S.

2010-12-01

294

Impact of reduced tillage on the greenhouse gas balance - a meta-analysis  

NASA Astrophysics Data System (ADS)

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.

Don, Axel; Jantz, Marc

2013-04-01

295

Outbursts from Supermassive Black Holes and Their Impacts on the Hot Gas in Elliptical Galaxies  

NASA Astrophysics Data System (ADS)

Many clusters have surface brightness distributions that are regular with strong peaks on a bright, central, often cD, galaxy. In the Einstein X-ray survey of 215 clusters, 64% of clusters contained a bright X-ray peak, centered on an optically bright galaxy [27]. These systems, described as X-ray Dominant (XD) clusters, are those that have high central gas densities and hence short cooling times. In the absence of energy input, the most remarkable XD systems are calculated to be depositing mass at rates as high as 1000 M? yr-1 (e.g., [14]). For many years, these centrally peaked, XD clusters have been described with a "cooling flow" model, first developed by Fabian & Nulsen [16] and Cowie & Binney [11]. However, observations with XMM-Newton have shown that mass deposition rates in cooling flow clusters, although still significant, are at least five times smaller than expected in the standard model ([37] and references therein). This requires considerable energy input to compensate for radiative losses.

Forman, W.; Jones, C.; Churazov, E.; Heinz, S.; Kraft, R.; Markevitch, M.; Nulsen, P.; Vikhlinin, A.

296

Gas phase hydrolysis of formaldehyde to form methanediol: impact of formic acid catalysis.  

PubMed

We find that formic acid (FA) is very effective at facilitating diol formation through its ability to reduce the barrier for the formaldehyde (HCHO) hydrolysis reaction. The rate limiting step in the mechanism involves the isomerization of a prereactive collision complex formed through either the HCHO···H2O + FA and/or HCHO + FA···H2O pathways. The present study finds that the effective barrier height, defined as the difference between the zero-point vibrational energy (ZPE) corrected energy of the transition state (TS) and the HCHO···H2O + FA and HCHO + FA···H2O starting reagents, are respectively only ?1 and ?4 kcal/mol. These barriers are substantially lower than the ?17 kcal/mol barrier associated with the corresponding step in the hydrolysis of HCHO catalyzed by a single water molecule (HCHO + H2O + H2O). The significantly lower barrier heights for the formic acid catalyzed pathway reveal a new important role that organic acids play in the gas phase hydrolysis of atmospheric carbonyl compounds. PMID:23614454

Hazra, Montu K; Francisco, Joseph S; Sinha, Amitabha

2013-11-21

297

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

Federal Register 2010, 2011, 2012, 2013

...of Oil and Gas Activities in the Arctic Ocean AGENCY: National Marine Fisheries...of Oil and Gas Activities in the Arctic Ocean.'' Publication of this notice...gas exploration activities in the Arctic Ocean pursuant to the Marine Mammal...

2011-12-30

298

Impact of energy maize cultivation and erosion on carbon gas exchange and soil organic carbon budgets in young moraine landscapes  

NASA Astrophysics Data System (ADS)

The hilly young moraine landscape of north-eastern Germany is dominated by the cultivation of energy crops like maize. It is suspected that this cultivation can increase erosion effects and lead to the release of soil carbon (C). Therefore, in an interdisciplinary approach, the CarboZALF project investigates the impact of various factors such as erosion on greenhouse gas (GHG) fluxes and C dynamics on the site and the landscape level. From the CarboZalf-D project site located in the Uckermark, we present measured and modeled GHG fluxes (CO2 and CH4) and C dynamics of maize on four erosion-related soil types: a) haplic luvisol, b) eroded haplic luvisol, c) haplic regosol (calcaric) and d) endogleyic colluvic regosol. CO2 flux measurements of ecosystem respiration (Reco) and net ecosystem exchange (NEE) were conducted every four weeks by using a non-flow-through non-steady-state closed chamber system (Livingston and Hutchinson 1995) based on Drösler (2005). Measurement gaps of NEE were filled by modeling the Reco fluxes using the Lloyd-Taylor (Lloyd and Taylor 1994) method and the gross primary production (GPP) fluxes using Michaelis-Menten (Michaelis and Menten 1913) modeling approach. Annual NEE balances were then calculated based on the modeled Reco and GPP fluxes. CH4 fluxes were measured bi-weekly using a static chamber system with interval sampling. The system C budget is the sum of annual NEE, C export and CH4-C values. The endogleyic colluvic regosol featured the highest uptake of CH4 (< 1 kg C ha-1 yr-1), but the impact of erosion on the cumulative CH4 fluxes was very small. However, erosion and deposition had a significant impact on GPP, NEE and the C export, but with little differences between the resulting annual C balances. All investigated soil types were C sinks, storing 620 - 2600 kg C ha-1 yr-1. We conclude that i) maize cultivation must not be accompanied by soil organic carbon loss; ii) erosion seems to cause spatial variability of GHG fluxes and soil organic carbon budgets at least at the site level. Due to the temporal variability of GHG fluxes, generalized conclusions are only possible after long term investigations. This also applies to the question concerning the degree to which erosion influences C dynamics at the landscape scale. Drösler, M. 2005. Trace Gas Exchange and climatic relevance of bog ecosystems, Southern Germany, phD-thesis, TU München, München Livingston, G.P. & Hutchinson, G.L. 1995. Enclosure-based measurement of trace gas exchange: Applications and sources of error. p. 14-51. In P.A. Matson & Harriss, R.C. (ed.) Methods in ecology - Biogenic trace gases: Measuring emissions from soil and water. Blackwell Science, Oxford, England

Pohl, M.; Hagemann, U.; Liebe, M.; Sommer, M.; Augustin, J.

2012-04-01

299

Greenhouse gas emissions from MSW incineration in China: Impacts of waste characteristics and energy recovery  

SciTech Connect

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.

Yang Na [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Zhang Hua, E-mail: zhanghua_tj@tongji.edu.cn [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Chen Miao; Shao Liming [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); He Pinjing, E-mail: xhpjk@tongji.edu.cn [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China)

2012-12-15

300

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

NASA Astrophysics Data System (ADS)

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

Susandi, A.

2004-12-01

301

Impacts of woodchip biochar additions on greenhouse gas production and sorption/degradation of two herbicides in a Minnesota soil.  

PubMed

A potential abatement to increasing levels of carbon dioxide (CO(2)) in the atmosphere is the use of pyrolysis to convert vegetative biomass into a more stable form of carbon (biochar) that could then be applied to the soil. However, the impacts of pyrolysis biochar on the soil system need to be assessed before initiating large scale biochar applications to agricultural fields. We compared CO(2) respiration, nitrous oxide (N(2)O) production, methane (CH(4)) oxidation and herbicide retention and transformation through laboratory incubations at field capacity in a Minnesota soil (Waukegan silt loam) with and without added biochar. CO(2) originating from the biochar needs to be subtracted from the soil-biochar combination in order to elucidate the impact of biochar on soil respiration. After this correction, biochar amendments reduced CO(2) production for all amendment levels tested (2, 5, 10, 20, 40 and 60% w/w; corresponding to 24-720 tha(-1) field application rates). In addition, biochar additions suppressed N(2)O production at all levels. However, these reductions were only significant at biochar amendment levels >20% w/w. Biochar additions also significantly suppressed ambient CH(4) oxidation at all levels compared to unamended soil. The addition of biochar (5% w/w) to soil increased the sorption of atrazine and acetochlor compared to non-amended soils, resulting in decreased dissipation rates of these herbicides. The recalcitrance of the biochar suggests that it could be a viable carbon sequestration strategy, and might provide substantial net greenhouse gas benefits if the reductions in N(2)O production are lasting. PMID:19647284

Spokas, K A; Koskinen, W C; Baker, J M; Reicosky, D C

2009-10-01

302

Clean Air Act Amendments of 1990: Impacts on natural gas markets. Summary of the annual GRI Energy Seminar (12th) for the GRI Board of Directors and Advisory Council. Held in Asheville, North Carolina on August 12-14, 1991  

Microsoft Academic Search

Each year, Gas Research Institute (GRI) conducts an energy seminar for its Board of Directors and Advisory Council on an issue of timely importance to the gas industry. The topic selected for the Twelfth Annual GRI Energy Seminar was 'Clean Air Act Amendments of 1990: Impacts on Natural Gas Markets.' The two sessions of the seminar focused upon the sectors

1991-01-01

303

The impact of ambient gas on the magnetic properties of Ti 40Zr 40Ni 20 powders during mechanical alloying  

NASA Astrophysics Data System (ADS)

Ti 40Zr 40Ni 20 in the form of elemental powders was mechanically alloyed in a planetary ball-mill under argon and hydrogen atmospheres at an acceleration of 55 m s -2 for different time intervals. The samples were analyzed by X-ray diffraction (XRD), vibrating-sample magnetometry (VSM) and scanning electron microscopy (SEM), which revealed the large impact of the ambient gas, i.e. argon and hydrogen, on the magnetic properties, morphology and structure. Namely, during mechanical alloying in argon the saturation magnetization decreased due to the modification of the Ni d-states upon alloying with paramagnetic Ti and Zr, whereas in hydrogen the Ni d-states remained largely unmodified, since the formation of TiH 2 and ZrH 2 was faster than the alloying with the ferromagnetic nickel. However, after 40 h we obtained a mixture of nanocrystalline Ni and ZrH 2/TiH 2 hydrides, which in equilibrium contained 1.55 mass% of hydrogen. In the case of argon we determined welding of the Ti 40Zr 40Ni 20 amorphous particles, whereas in hydrogen such a process was suppressed by the brittle ZrH 2/TiH 2 hydrides. In addition, we revealed that the mechanical alloying of pure Ni powder for 100 h in argon does not affect its magnetic properties.

Kocjan, A.; McGuiness, P. J.; Kobe, S.

2011-02-01

304

Impact of the renewable oxygenate standard for reformulated gasoline on ethanol demand, energy use, and greenhouse gas emissions  

SciTech Connect

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.

Stork, K.C.; Singh, M.K.

1995-04-01

305

Sulfur and Iron Speciation in Gas-rich Impact-melt Glasses from Basaltic Shergottites Determined by Microxanes  

NASA Technical Reports Server (NTRS)

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.

Sutton, S. R.; Rao, M. N.; Nyquist, L. E.

2008-01-01

306

The impact of using biodiesel/marine gas oil blends on exhaust emissions from a stationary diesel engine.  

PubMed

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

Karavalakis, G; Tzirakis, E; Mattheou, L; Stournas, S; Zannikos, F; Karonis, D

2008-12-01

307

Gas-phase reactive nitrogen near Grand Teton National Park: Impacts of transport, anthropogenic emissions, and biomass burning  

NASA Astrophysics Data System (ADS)

Excess inputs of reactive nitrogen can adversely affect terrestrial and aquatic ecosystems, particularly in sensitive ecosystems found at high elevations. Grand Teton National Park is home to such sensitive natural areas and is in proximity to potentially large reactive nitrogen sources. The Grand Teton Reactive Nitrogen Deposition Study (GrandTReNDS) was conducted in spring-summer 2011, with the aim of better understanding sources of reactive nitrogen influencing the region, spatial and temporal variability of reactive nitrogen in the atmosphere, and current levels of nitrogen deposition. Overall, NOy was determined to be the most abundant class of ambient gas phase reactive nitrogen compounds, and ammonia was determined to be the most abundant individual nitrogen species. NOx, NOy and NH3 concentrations all showed a diel cycle, with maximum concentrations during the day and minimum concentrations at night. This pattern appeared to be driven, in part, by mountain-valley circulation as well as long range transport, which brought air to the site from anthropogenic sources in the Snake River Valley and northern Utah. In addition to the nitrogen sources noted above, we found elevated concentrations of all measured nitrogen species during periods impacted by biomass burning.

Prenni, A. J.; Levin, E. J. T.; Benedict, K. B.; Sullivan, A. P.; Schurman, M. I.; Gebhart, K. A.; Day, D. E.; Carrico, C. M.; Malm, W. C.; Schichtel, B. A.; Collett, J. L.; Kreidenweis, S. M.

2014-06-01

308

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, 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.

Fritz, K.; Harris, S.; Edenborn, H.M.; Sams, J.

2011-01-01

309

Hypervelocity impact studies using the 2 MV Van de Graaff accelerator and two-stage light gas gun of the University of Kent at Canterbury  

Microsoft Academic Search

The hypervelocity impact facilities of the University of Kent are described. They comprise a 2 MV Van de Graaff accelerator for the electrostatic acceleration of dust particles (mass 0957-0233\\/10\\/1\\/011\\/img1 and velocities 0957-0233\\/10\\/1\\/011\\/img2) and a two-stage light gas gun firing millimetre-sized particles at 0957-0233\\/10\\/1\\/011\\/img3. Results for impact ionization studies using iron dust accelerated in the Van de Graaff and hitting a

M. J. Burchell; M. J. Cole; J. A. M. McDonnell; J. C. Zarnecki

1999-01-01

310

Identification of Isoflavone Metabolites Dihydrodaidzein, Dihydrogenistein, 6?OH O-dma, and cis-4OHequol in Human Urine by Gas Chromatography–Mass Spectroscopy Using Authentic Reference Compounds  

Microsoft Academic Search

The metabolic products of daidzein and genistein, the principal isoflavones of soy, were examined. Six volunteers included soy into their normal diet for a 2-week period and urine samples were analyzed before and after soy consumption. Isolation and characterization of the urinary metabolites were carried out with absorption chromatography on Sephadex LH-20 and gas chromatography–electron ionization mass spectrometry (GC–EIMS). The

S. Heinonen; K. Wähälä; H. Adlercreutz

1999-01-01

311

77 FR 2513 - Draft Environmental Impact Statement for Effects of Oil and Gas Activities in the Arctic Ocean  

Federal Register 2010, 2011, 2012, 2013

...Statement for Effects of Oil and Gas Activities in the Arctic Ocean AGENCY: National Marine Fisheries Service (NMFS...DEIS) for the Effects of Oil and Gas Activities in the Arctic Ocean.'' Based on several written requests received...

2012-01-18

312

78 FR 21347 - Supplemental Draft Environmental Impact Statement for Effects of Oil and Gas Activities in the...  

Federal Register 2010, 2011, 2012, 2013

...Statement for Effects of Oil and Gas Activities in the Arctic Ocean AGENCY: National Marine Fisheries Service (NMFS...DEIS) for the Effects of Oil and Gas Activities in the Arctic Ocean.'' Based on a written request received by...

2013-04-10

313

Broader jurisdiction for the Wyoming Oil and Gas Conservation Commission. Gulf Oil Corp. v. Wyoming Oil and Gas Conservation Commission and Story Oil Impact Committee, 693 P. 2d 227 (Wyo. 1985)  

SciTech Connect

Analysis of the Gulf Oil Corp. v. Wyoming Oil and Gas Conservation Commission and Story Oil Impact Committee case finds that the Wyoming Supreme Court has set an important precedent. The case stands for the premise that Wyoming may regulate the environmental effects of oil and gas development on lands outside of federal lease boundaries. The problem with this holding is that it was the wrong case in which to set that precedent. The Wyoming Oil and gas Conservation Act does not grant the Commission broad enough authority to regulate as they did, even if such regulation is not preempted at the federal level. While the court may have perceived a need to vest the Commission with this broad authority, it should leave such decisions to the state legislature or leave this type of regulation to the appropriate federal agency.

Wendtland, A.T.

1986-01-01

314

Toward the Impact of Fuel Evaporation-Combustion Interaction on Spray Combustion in Gas Turbine Combustion Chambers. Part I: Effect of Partial Fuel Vaporization on Spray Combustion  

Microsoft Academic Search

\\u000a This work aims at investigating the impact of the interaction between evaporation process and combustion on spray combustion\\u000a characteristics in gas turbine combustion chambers. It is subdivided into two parts. The first part studies how the evaporation\\u000a process affects the behavior of partially pre-vaporized spray combustion. The second part attempts to answer the question\\u000a how the fuel evaporation process behaves

Amsini Sadiki; W. Ahmadi; Mouldi Chrigui; J. Janicka

315

Determination of alkyltrimethylammonium surfactants in hair conditioners and fabric softeners by gas chromatography–mass spectrometry with electron-impact and chemical ionization  

Microsoft Academic Search

The commercial hair conditioners and fabric softeners were analyzed for the content of alkyltrimethylammonium compounds (ATMACs) by gas chromatography–mass spectrometry (GC–MS) with electron impact (EI) and low-pressure positive-ion chemical ionization (PICI) modes. The method involves mixed diluted samples (adjust pH to 10.0) with potassium iodide to enhance the extraction of iodide–ATMA+ ion pairs by direct liquid–liquid extraction. The iodide–ATMA+ pairs

Pei-Chuan Tsai; Wang-Hsien Ding

2004-01-01

316

Metal contamination of surface water, sediment and Tympanotonus fuscatus var. radula of Iko River and environmental impact due to Utapete gas flare station, Nigeria  

Microsoft Academic Search

Inter-seasonal studies on the trace metal load of surface water, sediment and Tympanotonus fuscatus var. radula of Iko River were conducted between 2003 and 2004. The impact of anthropogenic activities especially industrial effluent,\\u000a petroleum related wastes, gas flare and episodic oil spills on the ecosystem are remarkable. Trace metals analyzed included\\u000a cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead

Nsikak U. Benson; Usoro M. Etesin

2008-01-01

317

Reversible and irreversible impacts of greenhouse gas emissions in multi-century projections with the NCAR global coupled carbon cycle-climate model  

Microsoft Academic Search

The legacy of historical and the long-term impacts of 21st century greenhouse gas emissions on climate, ocean acidification,\\u000a and carbon-climate feedbacks are investigated with a coupled carbon cycle-climate model. Emission commitment scenarios with\\u000a zero emissions after year 2100 and 21st century emissions of 1,800, 900, and 0 gigatons of carbon are run up to year 2500.\\u000a The reversibility and irreversibility

Thomas L. Frölicher; Fortunat Joos

2010-01-01

318

78 FR 65637 - Sierrita Gas Pipeline LLC; Notice of Availability of the Draft Environmental Impact Statement for...  

Federal Register 2010, 2011, 2012, 2013

...proposed by Sierrita Gas Pipeline LLC (Sierrita...link El Paso Natural Gas Company's existing...sabe-Guaymas Pipeline at the U.S...participate in the NEPA analysis. Although the cooperating...36-inch-diameter natural gas pipeline in Pima...

2013-11-01

319

Impact of biochar application to a Mediterranean wheat crop on soil microbial activity and greenhouse gas fluxes.  

PubMed

Biochar has been recently proposed as a management strategy to improve crop productivity and global warming mitigation. However, the effect of such approach on soil greenhouse gas fluxes is highly uncertain and few data from field experiments are available. In a field trial, cultivated with wheat, biochar was added to the soil (3 or 6 kg m(-2)) in two growing seasons (2008/2009 and 2009/2010) so to monitor the effect of treatments on microbial parameters 3 months and 14 months after char addition. N(2)O, CH(4) and CO(2) fluxes were measured in the field during the first year after char addition. Biochar incorporation into the soil increased soil pH (from 5.2 to 6.7) and the rates of net N mineralization, soil microbial respiration and denitrification activity in the first 3 months, but after 14 months treated and control plots did not differ significantly. No changes in total microbial biomass and net nitrification rate were observed. In char treated plots, soil N(2)O fluxes were from 26% to 79% lower than N(2)O fluxes in control plots, excluding four sampling dates after the last fertilization with urea, when N(2)O emissions were higher in char treated plots. However, due to the high spatial variability, the observed differences were rarely significant. No significant differences of CH(4) fluxes and field soil respiration were observed among different treatments, with just few exceptions. Overall the char treatments showed a minimal impact on microbial parameters and GHG fluxes over the first 14 months after biochar incorporation. PMID:21944041

Castaldi, S; Riondino, M; Baronti, S; Esposito, F R; Marzaioli, R; Rutigliano, F A; Vaccari, F P; Miglietta, F

2011-11-01

320

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

Federal Register 2010, 2011, 2012, 2013

...Plan/Environmental Impact Statement for Big South Fork National River and Recreation...Plan/ Environmental Impact Statement for Big South Fork National River and Recreation...statement (OGMP/DEIS) for the proposed Big South Fork National River and...

2011-06-15

321

Global Impacts of Gas-Phase Chemistry-Aerosol Interactions on Direct Radiative Forcing by Anthropogenic Aerosols and Ozone  

NASA Technical Reports Server (NTRS)

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, NO3, NO2, and HO2 are predicted to have noticeable impacts on anthropogenic aerosol forcing over industrialized areas, leading to 0-2 W m(sup -2) more anthropogenic aerosol cooling in present-day and 2-8 W m(sup -2) more cooling in year 2100 in these areas as compared with forcings calculated in the absence of heterogeneous reactions. Sea salt uptake of SO2 reduces the magnitude of TOA aerosol cooling by 0.5-1 W m(sup -2) over the oceans around 60 N in the present-day and year 2100 scenarios. Near dust sources, mineral dust uptake of SO2 and HNO3 leads to less anthropogenic aerosol cooling by 0.5-1 W m(sup -2) in the present day and 1-2 W m(sup -2) in year 2100.

Liao, Hong; Seinfeld, John H.

2005-01-01

322

Evaluation of water-injection impacts for gas-turbine NOx control at compressor stations. Topical report, June-September 1989  

SciTech Connect

Acurex reviewed and analyzed data on operational impacts of water injection to control NOx emissions from gas turbines used in gas compression service and developed cost estimates. At a water/fuel (W/F) ratio of 1.0, weight basis, NOx from gas turbines can be reduced by as much as 70 to 80 percent. The performance is accompanied by a thermal efficiency loss of 2 to 3 percent and an increase in CO and hydrocarbon emissions. Although water injection is a mature technology that has been in use for about 15 years on numerous utility and cogeneration installations, operational experience and cost data for application on gas transmission engines are lacking. Costs published to date for water injection have not sufficiently addressed the incremental cost of increased turbine maintenance. Additionally, the cost to secure large quantities of water at remote locations, where many existing compressor station turbines operate, can significantly impact the economics of retrofit project. The life-cycle costs for such retrofit were estimated in the $8,000 to $12,000 per ton of NOx removed, influenced by site-specific factors such as water availability and quality, size of engine, degree of NOx control, and increased maintenance.

Castaldini, C.

1990-06-01

323

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)

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.

Jacquet, Jeffrey Bryan

324

Gulf of Mexico OCS Oil and Gas Lease Sales: 2014-2016, Eastern Planning Area Lease Sales 225 and 226, Final Environmental Impact Statement. Volume I: Chapters 1-8 and Keyword Index.  

National Technical Information Service (NTIS)

This environmental impact statement (EIS) addresses two proposed Federal actions that offer for lease an area on the Gulf of Mexico Outer Continental Shelf (OCS) that may contain economically recoverable oil and gas resources. Under the Proposed Final Out...

2013-01-01

325

Gulf of Mexico OCS Oil and Gas Lease Sales: 2014-2016, Eastern Planning Area Lease Sales 225 and 226, Draft Environmental Impact Statement. Volume I: Chapters 1-8 and Keyword Index.  

National Technical Information Service (NTIS)

This environmental impact statement (EIS) addresses two proposed Federal actions that offer for lease an area on the Gulf of Mexico Outer Continental Shelf (OCS) that may contain economically recoverable oil and gas resources. Under the Proposed Final Out...

2013-01-01

326

Gulf of Mexico OCS Oil and Gas Lease Sales: 2014 and 2016. Eastern Planning Area Lease Sales 225 and 226. Draft Environmental Impact Statements. Volume 2: Figures, Tables, and Appendices.  

National Technical Information Service (NTIS)

This environmental impact statement (EIS) addresses two proposed Federal actions that offer for lease an area on the Gulf of Mexico Outer Continental Shelf (OCS) that may contain economically recoverable oil and gas resources. Under the Proposed Final Out...

2013-01-01

327

The Impact of Wet Flue Gas Desulfurization Scrubbing on Mercury Emissions from Coal-Fired Power Stations  

Microsoft Academic Search

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,

Stephen Niksa; Naoki Fujiwara

2005-01-01

328

Analysis of the impact velocity of powder particles in the cold-gas dynamic-spray process  

Microsoft Academic Search

While built on a sound physical foundation, isentropic, one-dimensional models generally used to analyze the dynamics of dilute two-phase (feed-powder particles suspended in a carrier gas) flow during the cold-gas dynamic-spray process, require the use of numerical procedures to obtain solutions for the governing equations. Numerical solutions, unfortunately, do not enable an easy establishment of the relationships between the gas,

M. Grujicic; C. L. Zhao; C. Tonga; W. S. DeRosset; D. Helfritch

2004-01-01

329

Application of single-drop microextraction and comparison with solid-phase microextraction and solid-phase extraction for the determination of ?- and ?-endosulfan in water samples by gas chromatography–electron-capture detection  

Microsoft Academic Search

Water contamination due to the wide variety of pesticides used in agriculture practices is a global environmental pollution problem. The 98\\/83 European Directive requires the measurement of pesticides residues at a target concentration of 1.0 ?g\\/l in surface water and 0.1 ?g\\/l in drinking water. In order to reach the level of detection required, efficient extraction techniques are necessary. The

M. C López-Blanco; S Blanco-Cid; B Cancho-Grande; J Simal-Gándara

2003-01-01

330

Evaluation of impact of shale gas operations in the Barnett Shale region on volatile organic compounds in air and potential human health risks.  

PubMed

Shale gas exploration and production (E&P) has experienced substantial growth across the U.S. over the last decade. The Barnett Shale, in north-central Texas, contains one of the largest, most active onshore gas fields in North America, stretching across 5000 square miles and having an estimated 15,870 producing wells as of 2011. Given that these operations may occur in relatively close proximity to populated/urban areas, concerns have been expressed about potential impacts on human health. In response to these concerns, the Texas Commission on Environmental Quality established an extensive air monitoring network in the region. This network provides a unique data set for evaluating the potential impact of shale gas E&P activities on human health. As such, the objective of this study was to evaluate community-wide exposures to volatile organic compounds (VOCs) in the Barnett Shale region. In this current study, more than 4.6 million data points (representing data from seven monitors at six locations, up to 105 VOCs/monitor, and periods of record dating back to 2000) were evaluated. Measured air concentrations were compared to federal and state health-based air comparison values (HBACVs) to assess potential acute and chronic health effects. None of the measured VOC concentrations exceeded applicable acute HBACVs. Only one chemical (1,2-dibromoethane) exceeded its applicable chronic HBACV, but it is not known to be associated with shale gas production activities. Annual average concentrations were also evaluated in deterministic and probabilistic risk assessments and all risks/hazards were below levels of concern. The analyses demonstrate that, for the extensive number of VOCs measured, shale gas production activities have not resulted in community-wide exposures to those VOCs at levels that would pose a health concern. With the high density of active wells in this region, these findings may be useful for understanding potential health risks in other shale play regions. PMID:24076504

Bunch, A G; Perry, C S; Abraham, L; Wikoff, D S; Tachovsky, J A; Hixon, J G; Urban, J D; Harris, M A; Haws, L C

2014-01-15

331

Comparative evaluation of the impacts of domestic gas and electric heat pump heating on air pollution in California. Final report.  

National Technical Information Service (NTIS)

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...

A. Ganji

1992-01-01

332

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

Federal Register 2010, 2011, 2012, 2013

...of drilling up to 4,899 oil and/or natural gas wells over the next 15 years, with...of drilling up to 4,899 oil and/or natural gas wells over the next 15 years, with...proposed in this EIS is to economically extract, in an efficient and...

2010-08-23

333

REDUCING THE IMPACTS OF TRANSPORTATION ON GLOBAL WARMING: SUMMARY OF NEW YORK GREENHOUSE GAS TASK FORCE RECOMMENDATIONS  

Microsoft Academic Search

Global climate change is fundamentally caused by fossil fuel combustion. The transportation sector generates more than one-third of greenhouse gas (GHG) emissions in New York and represents the fastest-growing source of GHG emissions in the state. A summary of the recommendations of the New York Greenhouse Gas Task Force for reducing GHG emissions from the transportation sector is provided. Using

Steven Winkelman; Greg Dierkers

2003-01-01

334

Rapid determination of dichlorodiphenyltrichloroethane and its main metabolites in aqueous samples by one-step microwave-assisted headspace controlled-temperature liquid-phase microextraction and gas chromatography with electron capture detection  

Microsoft Academic Search

A rapid and sensitive analytical method for the determination of dichlorodiphenyltrichloroethane (DDT) and its main metabolites in environmental aqueous samples has been developed using one-step microwave-assisted headspace controlled-temperature liquid-phase micro-extraction (MA-HS-CT-LPME) technique coupled with gas chromatography–electron-capture detection (GC–ECD). In this study, the one-step extraction of DDT and its main metabolites was achieved by using microwave heating to accelerate the evaporation

Ponnusamy Vinoth Kumar; Jen-Fon Jen

2011-01-01

335

Contemporaneous mass extinctions, continental flood basalts, and `impact signals': are mantle plume-induced lithospheric gas explosions the causal link?  

Microsoft Academic Search

Contemporaneous occurrences of the geologic signals of `large impacts', craton-associated continental flood basalts, and mass extinctions have occurred far too often during the past 400 Myr to be plausibly attributed to random coincidence. While there is only a 1 in 8 chance that even one synchronous large impact within the interval of a continental flood basalt and mass extinction event

J. Phipps Morgan; T. J. Reston; C. R. Ranero

2004-01-01

336

Contemporaneous mass extinctions, continental flood basalts, and ‘impact signals’: are mantle plume-induced lithospheric gas explosions the causal link?  

Microsoft Academic Search

Contemporaneous occurrences of the geologic signals of ‘large impacts’, craton-associated continental flood basalts, and mass extinctions have occurred far too often during the past 400 Myr to be plausibly attributed to random coincidence. While there is only a 1 in 8 chance that even one synchronous large impact within the interval of a continental flood basalt and mass extinction event

J Phipps Morgan; T. J Reston; C. R Ranero

2004-01-01

337

The Impact Of Turbulence On The Physical State Of The Molecular Gas And On Star Formation In Galaxy Interactions: The Case Of Stephan's Quintet  

NASA Astrophysics Data System (ADS)

Spitzer spectroscopy has revealed a significant and diverse population of extragalactic sources where the mid-infrared rotational line emission of warm (> 150 K) molecular hydrogen (H2) is strongly enhanced, while star formation seems suppressed. This poster focuses on the Stephan's Quintet (SQ) compact group of galaxies, a template source to study the impact of galaxies interaction on the physical state and energetics of their gas. SQ is a spectacular example of these powerful H2 emitters, where we can spatially separate molecular gas formed in the shock from that associated with star-forming regions. I will present CO line observations obtained with the IRAM 30m and interferometer, showing that the collision has triggered the formation of highly turbulent, unbound giant molecular complexes. The ratio between the warm H2 mass and the H2 mass derived from CO fluxes is 0.3, which is 10-100 times higher than in star-forming galaxies. I will discuss a model for molecular gas formation and heating by the dissipation of turbulent kinetic energy. This interpretation implies that the velocity dispersion on the scale of giant molecular clouds in SQ is an order of magnitude larger than the Galactic value. This may explain why this gas is not forming stars efficiently. This study has important consequences on our understanding of the regulation of star formation and galaxy building in a broader population of sources experiencing strong input of kinetic energy in their interstellar medium.

Guillard, Pierre; Boulanger, F.; Appleton, P.; Falgarone, E.; Gusdorf, A.; Lisenfeld, U.; Duc, P.

2012-05-01

338

Impact of the etching gas on vertically oriented single wall and few walled carbon nanotubes by plasma enhanced chemical vapor deposition  

SciTech Connect

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)

Gohier, A.; Minea, T. M.; Djouadi, M. A.; Granier, A. [IMN-PCM, UMR 6502 CNRS-Universite de Nantes, BP 32229, 44322 Nantes (France); LPGP, UMR 8578 CNRS-Universite Paris Sud, Batiment 210, 91405 Orsay (France); IMN-PCM, UMR 6502 CNRS-Universite de Nantes, BP 32229, 44322 Nantes (France)

2007-03-01

339

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)

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.

Bangert, M.; Vogel, B.; Junkermann, W.; Brachert, L.; Schaber, K.

2013-05-01

340

Single microparticle launching method using two-stage light-gas gun for simulating hypervelocity impacts of micrometeoroids and space debris.  

PubMed

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

Kawai, Nobuaki; Tsurui, Kenji; Hasegawa, Sunao; Sato, Eiichi

2010-11-01

341

Evaluation of the impact on emissions and fuel economy of converting two vehicles to compressed natural gas fuel. Technical report  

Microsoft Academic Search

The EPA was requested by the Department of Energy to perform testing on two late model vehicles which had been converted with on-the-market systems to run on compressed natural gas (CNG). The EPA was requested to measure vehicle emissions, fuel economy, and acceleration characteristics of the vehicles in stock configuration, modified running on gasoline, and modified-running on natural gas. The

Penninga

1981-01-01

342

Explicit Finite Element Modeling of Multilayer Composite Fabric for Gas Turbine Engine Containment Systems. Part 2; Ballistic Impact Testing  

NASA Technical Reports Server (NTRS)

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.

Pereira, J. M.; Revilock, D. M.

2004-01-01

343

[Health and environmental licensing: a methodological proposal for assessment of the impact of the oil and gas industry].  

PubMed

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

Barbosa, Eduardo Macedo; Barata, Matha Macedo de Lima; Hacon, Sandra de Souza

2012-02-01

344

77 FR 47052 - El Paso Natural Gas Company; Notice of Intent To Prepare an Environmental Impact Statement for...  

Federal Register 2010, 2011, 2012, 2013

...right-of-way after construction; Impacts on threatened and endangered species (including the masked bobwhite quail, Pima pineapple cactus, and Chiricahua leopard frog) and other sensitive species (including the cactus ferruginous pygmy owl); and...

2012-08-07

345

Commission Staff Reports Impact of 1981-82 Winter Gas Supply for Twenty-Eight Pipeline Companies.  

National Technical Information Service (NTIS)

The purpose of this report is to describe results of the Federal Energy Regulatory Commission (Commission) staff's survey of short-term supply and curtailment impacts as projected for the forthcoming winter heating season, November, 1981 through March, 19...

1981-01-01

346

Semiempirical model of impact interaction of a disperse impurity particle with a surface in a gas suspension flow  

SciTech Connect

A mathematical model describing the dynamics of impact of a spherical particle on a solid surface is proposed and investigated. In closing the model, use is made of the experimental mean statistical values off the coefficients of restitution of the components of the velocity vector of the center of mass of the particle normal and tangential to the surface. The model permits a physically correct description of particle rotation upon impact and determination of its angular rotational velocity.

Tsirkunov, Yu.M.; Panfilov, S.V.; Klychnikov, M.B. [Baltic State Technical Univ., St. Petersburg (Russian Federation)

1995-06-01

347

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)

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 scenarios, i.e., an anthropogenically vs. a more biogenically impacted one as being representative for Davis and Whistler, respectively. Since the simplicity of the box model prevents a fully quantitative prediction of the observed aldehyde concentrations, we rather use the model results to compare trends in aldehyde partitioning and ratios. They suggest that the scavenging of aldehydes by the aqueous phase can reduce HO2 gas phase levels significantly by two orders of magnitude due to a weaker net source of HO2 production from aldehyde photolysis in the gas phase. Despite the high solubility of dicarbonyl compounds (glyoxal, methylglyoxal), their impact on the HO2 budget by scavenging is < 10% of that of formaldehyde. The overview of DOC and aldehyde measurements presented here reveals that clouds and fogs can be efficient sinks for organics, with increasing importance in aged air masses. Even though aldehydes, specifically formaldehyde, only comprise ~ 1% of DOC, their scavenging and processing in the aqueous phase might translate into significant effects in the oxidation capacity of the atmosphere.

Ervens, B.; Wang, Y.; Eagar, J.; Leaitch, W. R.; Macdonald, A. M.; Valsaraj, K. T.; Herckes, P.

2013-05-01

348

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)

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.

Calvello, M.; Esposito, F.; Trippetta, S.

2014-04-01

349

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

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.

Taleyarkhan, R.P.; Kim, S.H. [Oak Ridge National Lab., TN (United States); Gulec, K. [Oak Ridge Associated Universities, TN (United States)

1998-05-01

350

The impact of plasma-wall interaction on the gas mixing efficiency in electron cyclotron resonance ion source.  

PubMed

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. PMID:22380195

Schachter, L; Stiebing, K E; Dobrescu, S

2012-02-01

351

Analysis of Restricted Natural Gas Supply Cases  

EIA Publications

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.

James Kendell

2004-03-01

352

Enhanced Photoacoustic Gas Analyser Response Time and Impact on Accuracy at Fast Ventilation Rates during Multiple Breath Washout  

PubMed Central

Background The Innocor device contains a highly sensitive photoacoustic gas analyser that has been used to perform multiple breath washout (MBW) measurements using very low concentrations of the tracer gas SF6. Use in smaller subjects has been restricted by the requirement for a gas analyser response time of <100 ms, in order to ensure accurate estimation of lung volumes at rapid ventilation rates. Methods A series of previously reported and novel enhancements were made to the gas analyser to produce a clinically practical system with a reduced response time. An enhanced lung model system, capable of delivering highly accurate ventilation rates and volumes, was used to assess in vitro accuracy of functional residual capacity (FRC) volume calculation and the effects of flow and gas signal alignment on this. Results 10–90% rise time was reduced from 154 to 88 ms. In an adult/child lung model, accuracy of volume calculation was ?0.9 to 2.9% for all measurements, including those with ventilation rate of 30/min and FRC of 0.5 L; for the un-enhanced system, accuracy deteriorated at higher ventilation rates and smaller FRC. In a separate smaller lung model (ventilation rate 60/min, FRC 250 ml, tidal volume 100 ml), mean accuracy of FRC measurement for the enhanced system was minus 0.95% (range ?3.8 to 2.0%). Error sensitivity to flow and gas signal alignment was increased by ventilation rate, smaller FRC and slower analyser response time. Conclusion The Innocor analyser can be enhanced to reliably generate highly accurate FRC measurements down at volumes as low as those simulating infant lung settings. Signal alignment is a critical factor. With these enhancements, the Innocor analyser exceeds key technical component recommendations for MBW apparatus.

Horsley, Alex; Macleod, Kenneth; Gupta, Ruchi; Goddard, Nick; Bell, Nicholas

2014-01-01

353

Impacts of Increased Access to Oil & Natural Gas Resources in the Lower 48 Federal Outer Continental Shelf (released in AEO2007)  

EIA Publications

This analysis was updated for Annual Energy Outlook 2009 (AEO): Impact of Limitations on Access to Oil and Natural Gas Resources in the Federal Outer Continental Shelf (OCS). The OCS is estimated to contain substantial resources of crude oil and natural gas; however, some areas of the OCS are subject to drilling restrictions. With energy prices rising over the past several years, there has been increased interest in the development of more domestic oil and natural gas supply, including OCS resources. In the past, federal efforts to encourage exploration and development activities in the deep waters of the OCS have been limited primarily to regulations that would reduce royalty payments by lease holders. More recently, the states of Alaska and Virginia have asked the federal government to consider leasing in areas off their coastlines that are off limits as a result of actions by the President or Congress. In response, the Minerals Management Service (MMS) of the U.S. Department of the Interior has included in its proposed 5-year leasing plan for 2007-2012 sales of one lease in the Mid-Atlantic area off the coastline of Virginia and two leases in the North Aleutian Basin area of Alaska. Development in both areas still would require lifting of the current ban on drilling.

Information Center

2007-02-22

354

Impact of oil and gas vents and slicks on petroleum exploration in the deepwater Gulf of Mexico  

Microsoft Academic Search

Active petroleum vents and slicks have been identified in the deep water of the northern Gulf of Mexico using numerous techniques. The occurrence and distribution of these petroleum vents are strongly influenced by the local geological framework—especially the presence of vertical migration pathways into shallow sediments. Oil and gas vents may be more useful for establishing the existence of petroleum

A. S. Kornacki; J. W. Kendrick; J. L. Berry

1994-01-01

355

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

...Statement on the Effects of Oil and Gas Activities in the Arctic Ocean AGENCY: National Marine Fisheries Service (NMFS...activities in state and Federal waters in the U.S. Arctic Ocean in the Beaufort and Chukchi Seas. Finally, the...

2010-02-08

356

TECHNICAL-ECONOMICAL ANALYSIS OF THE ENVIRONMENTAL IMPACT AND CORRESPONDING SUSTAINABILITY INDICATORS OF THE USE OF NATURAL GAS IN MEXICO  

Microsoft Academic Search

1. INTRODUCTION Gaseous hydrocarbons constitute an important share of the internal energy supply on which the country's development depends, and will continue to be so, in particular in view of the proposed intensified use of natural gas. Recently, on the grounds of environmental concerns to a large extent, Mexico's energy policy has been directed to promote the use of natural

Mariano Bauer; Eva Melgar; Rafael Villaseñor; Moisés Magdaleno; Alberto Elizalde; Elizabeth Mar; Eugenio Ceballos; Gloria Yáñez

357

Differential Treatment of Pregnancy in Employment: The Impact of "General Electric Co. v. Gilbert" and "Nashville Gas Co. v. Satty."  

ERIC Educational Resources Information Center

After discussing the facts and reasoning of the two cases (General Electric Co. vs Gilbert and Nashville Gas Co. vs Satty), the author argues that the decisions are largely the product of pregnancy stereotypes and that the Court's reasoning is flawed and should not be applied outside the context of pregnancy. Journal availability: see EA 511 481.…

Taylor, Ellen T.

1978-01-01

358

Chukchi Sea Oil and Gas Lease Sale 126, Alaska Outer Continental Shelf, Draft Environmental Impact Statement. Volume 1.  

National Technical Information Service (NTIS)

The EIS analyzes a proposed oil and gas lease sale in the Chukchi Sea, alternatives to the proposal, major issues determined through the scoping process, and potential mitigating measures. The proposal consists of 4,319 blocks located in the Chukchi Sea P...

G. Allen

1990-01-01

359

Alaska Outer Continental Shelf Beaufort Sea Planning Area Oil and Gas Lease Sale 124. Final Environmental Impact Statement.  

National Technical Information Service (NTIS)

This EIS analyzes a proposed oil and gas lease sale in the Beaufort Sea, alternatives to the proposal, major issues determined through the scoping process, and potential mitigating measures. The proposal consists of 4,095 blocks, located in the Beaufort S...

R. Roberts

1990-01-01

360

Chukchi Sea Oil and Gas Lease Sale 126, Alaska Outer Continental Shelf, Draft Environmental Impact Statement. Volume 2.  

National Technical Information Service (NTIS)

The EIS analyzes a proposed oil and gas lease sale in the Chukchi Sea, alternatives to the proposal, major issued determined through the scoping process, and potential mitigating measures. The proposal consists of 4,319 blocks located in the Chukchi Sea P...

G. Allen

1990-01-01

361

Volumetric strain associated with methane desorption and its impact on coalbed gas production from deep coal seams  

SciTech Connect

For deep coal seams, significant reservoir pressure drawdown is required to promote gas desorption because of the Langmuir-type isotherm that typifies coals. Hence, a large permeability decline may occur because of pressure drawdown and the resulting increase in effective stress, depending on coal properties and the stress field during production. However, the permeability decline can potentially be offset by the permeability enhancement caused by the matrix shrinkage associated with methane desorption. The predictability of varying permeability is critical for coalbed gas exploration and production-well management. We have investigated quantitatively the effects of reservoir pressure and sorption-induced volumetric strain on coal-seam permeability with constraints from the adsorption isotherm and associated volumetric strain measured on a Cretaceous Mesaverde Group coal (Piceance basin) and derived a stress-dependent permeability model. Our results suggest that the favorable coal properties that can result in less permeability reduction during earlier production and an earlier strong permeability rebound (increase in permeability caused by coal shrinkage) with methane desorption include (1) large bulk or Young's modulus; (2) large adsorption or Langmuir volume; (3) high Langmuir pressure; (4) high initial permeability and dense cleat spacing; and (5) low initial reservoir pressure and high in-situ gas content. Permeability variation with gas production is further dependent on the orientation of the coal seam, the reservoir stress field, and the cleat structure. Well completion with injection of N2 and displacement of CH{sub 4} only results in short-term enhancement of permeability and does not promote the overall gas production for the coal studied.

Cui, X.J.; Bustin, R.M. [University of British Columbia, Vancouver, BC (Canada). Dept. of Earth & Ocean Science

2005-09-01

362

Potential impacts of climate change on nitrogen transformations and greenhouse gas fluxes in forests: a soil transfer study  

Microsoft Academic Search

Relatively little research has been conducted on how climate change may affect the structure and function of arid to semiarid ecosystems of the American Southwest. Along the slopes of the San Francisco Peaks of Arizona, USA, I transferred intact soil cores from a spruce-fir to a ponderosa pine forest 730m lower in elevation to assess the potential impacts of climate

STEPHEN C. H ART

2006-01-01

363

The greenhouse gas and energy impacts of using wood instead of alternatives in residential construction in the United States  

Microsoft Academic Search

Data developed by the Consortium for Research on Renewable Industrial Materials were used to estimate savings of greenhouse gas emissions and energy consumption associated with use of wood-based building materials in residential construction in the United States. Results indicate that houses with wood-based wall systems require 15–16% less total energy for non-heating\\/cooling purposes than thermally comparable houses employing alternative steel-

Brad Upton; Reid Miner; Mike Spinney; Linda S. Heath

2008-01-01

364

Technology choice in a least-cost expansion analysis framework: The impact of gas prices, planning horizon, and system characteristics  

SciTech Connect

The current outlook for new capacity addition by electric utilities is uncertain and tenuous. Regardless of the amount, it is inevitable that new capacity will be needed in the 1990s and beyond. The fundamental question about the addition capacity requirements centers on technology choice and the factors influencing the decision process. We examined technology choices in 10 representative power pools with a dynamic optimization expansion model, the Wien Automatic System Planning (WASP) Package. These 10 power pools were determined to be representative on the basis of a cluster analysis conducted on all 26 power pools in the United States. A least-cost expansion plan was determined for each power pool with three candidate technologies--natural gas combustion turbine (CT), natural gas combined cycle (NGCC), and integrated gasification combined cycle (IGCC)--three alternative gas price tracks, and two planning horizons between the years 1995 and 2020. This paper summarizes the analysis framework and presents results for Power Pool 1, the American Electric Power (AEP) service territory. 7 refs., 9 figs., 1 tab.

Guziel, K.A.; South, D.W.

1990-01-01

365

Comparison of impacts on macroinvertebrates and fish from gas pipeline installation by wet-ditching and plowing  

SciTech Connect

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.

Vinikour, W.S.; Schubert, J.P.; Gartman, D.K.

1987-01-01

366

LARGE-SCALE SHOCK-IONIZED AND PHOTOIONIZED GAS IN M83: THE IMPACT OF STAR FORMATION  

SciTech Connect

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 energy produced by the central starburst in M83.

Hong, Sungryong; Calzetti, Daniela [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Dopita, Michael A. [Research School of Astronomy and Astrophysics, Australian National University, ACT 2611 (Australia); Blair, William P. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Whitmore, Bradley C.; Bond, Howard E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Balick, Bruce [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Carollo, Marcella [Department of Physics, ETH-Zurich, Zurich 8093 (Switzerland); Disney, Michael J. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Frogel, Jay A. [Association of Universities for Research in Astronomy, Washington, DC 20005 (United States); Hall, Donald [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Holtzman, Jon A. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Kimble, Randy A. [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); McCarthy, Patrick J. [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101-1292 (United States); O'Connell, Robert W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Paresce, Francesco [Istituto di Astrofisica Spaziale e Fisica Cosmica, INAF, Via Gobetti 101, 40129 Bologna (Italy); Saha, Abhijit [National Optical Astronomy Observatories, Tucson, AZ 85726-6732 (United States); Silk, Joseph I. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Trauger, John T. [NASA-Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Walker, Alistair R., E-mail: wpb@pha.jhu.edu [Cerro Tololo Inter-American Observatory, La Serena (Chile)

2011-04-10

367

Impact of hot fluid advection on hydrocarbon gas production and seepage in mud volcano sediments of thick Cenozoic deltas  

NASA Astrophysics Data System (ADS)

Hydrocarbon seeps are ubiquitous at gas-prone Cenozoic deltas such as the Nile Deep Sea Fan (NDSF) where seepage into the bottom water has been observed at several mud volcanoes (MVs) including North Alex MV (NAMV). Here we investigated the sources of hydrocarbon gases and sedimentary organic matter together with biomarkers of microbial activity at four locations of NAMV to constrain how venting at the seafloor relates to the generation of hydrocarbon gases in deeper sediments. At the centre, high upward flux of hot (70 °C) hydrocarbon-rich fluids is indicated by an absence of biomarkers of Anaerobic Oxidation of Methane (AOM) and nearly constant methane (CH4) concentration depth-profile. The presence of lipids of incompatible thermal maturities points to mixing between early-mature petroleum and immature organic matter, indicating that shallow mud has been mobilized by the influx of deep-sourced hydrocarbon-rich fluids. Methane is enriched in the heavier isotopes, with values of ?13C˜-46.6‰VPDB and ?D ˜-228‰VSMOW, and is associated with high amounts of heavier homologues (C2+) suggesting a co-genetic origin with the petroleum. 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 ?13C-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. NAMV: North Alex mud volcano.

Nuzzo, Marianne; Elvert, Marcus; Schmidt, Mark; Scholz, Florian; Reitz, Anja; Hinrichs, Kai-Uwe; Hensen, Christian

2012-08-01

368

Identification of character-impact odorants in coriander and wild coriander leaves using gas chromatography-olfactometry (GCO) and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOFMS).  

PubMed

The essential oil of coriander leaves (Coriandrum sativum) and wild coriander leaves (Eryngium foetidum) grown in Fiji was obtained by steam distillation. The aroma profiles were characterised using gas chromatography-olfactometry (GCO) and CharmAnalysis. The character-impact odorants were identified using comprehensive two-dimensional gas chromatography (GC x GC) combined with time-of-flight mass spectrometry (TOFMS). During GCO analysis, the co-elution of E-2-alkenals and E-2-alken-1-ols resulted in the perception of 'odour-clusters'. The most important odorants in C. sativum were found to be Z-2-decenal, a co-eluting odour-cluster (E-2-dodecenal, E-2-dodecen-1-ol, and 1-dodecanol), beta-ionone, eugenol, and E-2-decenal. E-2-decen-1-ol was the most abundant compound in C. sativum (26.0% TIC) but only contributed 0.39% of the total odour activity. The most abundant compound in E. foetidum was E-2-dodecenal (63.5% TIC), which also contributed the most odour activity (52.9%). Other important odorants were either eugenol or a trimethylbenzaldehyde isomer, beta-ionone, Z-4-dodecenal, dodecanal, and E-2-tetradecenal. GC x GC-TOFMS allowed the identification of 42 and 20 compounds not previously reported in the literature for C. sativum and E. foetidum, respectively. In particular, beta-ionone was determined to be an important odorant in both samples but could not be identified with GC-qMS. PMID:16013833

Eyres, Graham; Dufour, Jean-Pierre; Hallifax, Gabrielle; Sotheeswaran, Subramaniam; Marriott, Philip J

2005-06-01

369

The impact of wet flue gas desulfurization scrubbing on mercury emissions from coal-fired power stations.  

PubMed

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

Niksa, Stephen; Fujiwara, Naoki

2005-07-01

370

Vesiculation, melt formation, noble gas/nitrogen behaviour, and impact chronology on a planetary regolith : the case of Benccubbin (CB) meteorite  

NASA Astrophysics Data System (ADS)

The Benccubbin meteorite is a member of the CB peculiar meteorite family, which all have reduced silicates, metal zoning, solar Ni/Co and large enrichments in 15N, that have been regarded as relics of their very primitive character. However, these meteorites also show tugsten isotopic ratios suggesting metal differentiation events several Ma after start of solar system formation. The Benccubbin mineralogy is best explained as being an heterogeneous planetary regolith containing clasts of different origins (e.g., CO, CI chondrules and clasts, silicates of unknown origin). This meteorite presents evidence of having been impacted, such as melt, temperature gradient recorded at the silicate/metal interface, and textures indicative of rapid cooling. Notably, Benccubbin contains vesicles in several phases : partially molten silicate clasts and CO chondrules, impact melt, and the so-called bubble grains 1. We have analysed several Benccubbin mineral and metal phases for N and noble gas isotopes and abundances by both laser fusion and vacuum crushing. 15N-rich nitrogen (d15N up to +1,000 per mil) is ubiquituous, particularly inside vesicles, and is associated with noble gases. Notably, N and noble gases appear to have largely exchanged between silicate and vesicles, reaching locally equilibrium partitioning. Gases are still released after extensive crushing up to 4,000 strokes, in contrast to the case of MORB glasses and suggesting a foam-like, decompression structure of the impacted melt. N and Ar correlate well, showing that the N solubility was comparable to that of Ar and therefore that the redox conditions were above IW, according to 2. From the N content of the glass, we estimate that it equilibrated with a vapor plume in which the pressure of nitrogen was ~300 Bar. Radiogenic 40Ar is present inside the vesicles, showing that the vesiculation event was not an early process. Ar-Ar dating of Benccubbin suggests involvement in an impact around 4.2 Ga. In contrast to very variable N and primordial noble gas contents among different phases, cosmogenic 3He, 21Ne and 38Ar abundances are uniform, and vesicles contain little cosmogenic isotopes, showing that space exposure occurred after the vesicle forming impact event. Hence the event that led to the ejection of the Benccubbin meteorite was distinct from the vesiculation one, and occurred 40-50 Ma ago according to cosmogenic 3He, 21Ne and 38Ar isotopes and 38Ar-37Ar correlation. Noble gases have been well preserved in vesicles from cosmic ray isotope contributions, permitting to determine their origin precisely despite extensive exposure in space. Noble gases present Q-like isotopic ratios but highly fractionated abundances with respect to Q. The fact that comets are definitely rich in 15N 3 and may also have Q-like noble gas signature in their refractory phases 4 is suggestive of a possible link between cometary matter and CBs. 1. Perron, C., Fieni, C. and Guilhaumou, N. Geochim.Cosmochim. Acta 72, 959-977 (2008). 2. Libourel, G., Marty, B. and Humbert, F. Geochim. Cosmochim. Acta 67, 4123-4135 (2003). 3. Bockelee-Morvan, D. et al. Large excess of heavy nitrogen in both hydrogen cyanide and cyanogen from comet 17P/Holmes. Ap J.679, L49-L52 (2008). 4. Marty, B. et al. Science 319, 75-78 (2008).

Marty, B.; Turner, G.; Kelley, S. P.

2008-12-01

371

An analytical investigation of 24 oxygenated-PAHs (OPAHs) using liquid and gas chromatography-mass spectrometry.  

PubMed

We developed two independent approaches for separation and quantitation of 24 oxygenated polycyclic aromatic hydrocarbons (OPAHs) using both liquid chromatography-atmospheric pressure chemical ionization/mass spectrometry (LC-APCI/MS) and gas chromatography-electron impact/mass spectrometry (GC-EI/MS). Building on previous OPAH research, we examined laboratory stability of OPAHs, improved existing method parameters, and compared quantification strategies using standard addition and an internal standard on an environmental sample. Of 24 OPAHs targeted in this research, 19 compounds are shared between methods, with 3 uniquely quantitated by GC-EI/MS and 2 by LC-APCI/MS. Using calibration standards, all GC-EI/MS OPAHs were within 15 % of the true value and had less than 15 % relative standard deviations (RSDs) for interday variability. Similarly, all LC-APCI/MS OPAHs were within 20 % of the true value and had less than 15 % RSDs for interday variability. Instrument limits of detection ranged from 0.18 to 36 ng mL(-1) on the GC-EI/MS and 2.6 to 26 ng mL(-1) on the LC-APCI/MS. Four standard reference materials were analyzed with each method, and we report some compounds not previously published in these materials, such as perinaphthenone and xanthone. Finally, an environmental passive sampling extract from Portland Harbor Superfund, OR was analyzed by each method using both internal standard and standard addition to compensate for potential matrix effects. Internal standard quantitation resulted in increased precision with similar accuracy to standard addition for most OPAHs using 2-fluoro-fluorenone-(13)C as an internal standard. Overall, this work improves upon OPAH analytical methods and provides some considerations and strategies for OPAHs as focus continues to expand on this emerging chemical class. PMID:24005604

O'Connell, Steven G; Haigh, Theodore; Wilson, Glenn; Anderson, Kim A

2013-11-01

372

On vertical variations of gas flow in protoplanetary disks and their impact on the transport of solids  

NASA Astrophysics Data System (ADS)

A major uncertainty in accretion disk theory is the nature and properties of gas turbulence, which drives transport in protoplanetary disks. The commonly used viscous prescription for the Maxwell-Reynolds stress tensor gives rise to a meridional circulation where flow is outward near the midplane and inward away from it. This meridional circulation has been proposed as an explanation for the presence of high-temperature minerals (believed to be of inner solar system provenance) in comets. However, it has not been observed in simulations of magnetohydrodynamical (MHD) turbulence so far. In this study, we evaluate the extent to which the net transport of solids can be diagnostic of the existence of meridional circulation. To that end, we propose and motivate a prescription for MHD turbulence which has the same free parameters as the viscous one. We compare the effects of both prescriptions on the radial transport of small solid particles and find that their net, vertically integrated radial flux is actually quite insensitive to the flow structure for a given vertical average of the turbulence parameter ?, which we explain. Given current uncertainties on disk turbulence, one-dimensional models are thus most appropriate to investigate radial transport of solids. A corollary is that the presence of high-temperature material in comets cannot be considered an unequivocal diagnostic of meridional circulation. In fact, we argue that outward transport in viscous disk models with inward net accretion is more properly attributed to turbulent diffusion rather than to the mean flows of the gas.

Jacquet, E.

2013-03-01

373

Direct analysis of sulfate reducing bacterial communities in gas hydrate-impacted marine sediments by PCR-DGGE.  

PubMed

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

Bagwell, Christopher E; Formolo, Michael; Ye, Qi; Yeager, Chris M; Lyons, Timothy W; Zhang, Chuanlun L

2009-09-01

374

CO2 injectivity in saline aquifers: The impact of non-Darcy flow, phase miscibility, and gas compressibility  

NASA Astrophysics Data System (ADS)

key aspect of CO2 storage is the injection rate into the subsurface, which is limited by the pressure at which formation starts to fracture. Hence, it is vital to assess all of the relevant processes that may contribute to the pressure increase in the aquifer during CO2 injection. Building on an existing analytical solution for immiscible and spatially varying non-Darcy flow, this paper presents a mathematical model that accounts for combined effects of non-Darcy flow, phase miscibility, and gas compressibility in radial two-phase displacements. Results show that in low-permeability formations when CO2 is injected at high rates, non-Darcy simulations forecast better displacement efficiency compared to flow under Darcy conditions. This will have a positive effect on the formation CO2 storage capacity. This, however, comes at the cost of increased well pressures. More favorable estimations of the pressure buildup are obtained when CO2 compressibility is taken into account because reservoir pressures are reduced due to the change in the gas phase properties. Also, non-Darcy flow results in a significant reduction in halite precipitation in the near-well region, with a positive effect on CO2 injectivity. In the examples shown, non-Darcy flow conditions may lead to significantly different pressure and saturation distributions in the near-well region, with potentially important implications for CO2 injectivity.

Mijic, Ana; LaForce, Tara C.; Muggeridge, Ann H.

2014-05-01

375

The dilemma of contact: voluntary isolation and the impacts of gas exploitation on health and rights in the Kugapakori Nahua Reserve, Peruvian Amazon  

NASA Astrophysics Data System (ADS)

Many small groups of indigenous peoples in the Amazon basin avoid and resist direct encounters with outsiders. As far as we know, they do so because of appalling experiences in earlier encounters with national society. When contacted today, they are extremely vulnerable to introduced diseases and exploitation. In this paper we draw on our experience in the Kugapakori Nahua Reserve for isolated peoples in SE Peru to discuss some of the current debates about whether isolated peoples should be contacted and how best to respect their right to life, health, autonomy and territory. The remote headwater regions where isolated peoples sought refuge during the last century are increasingly sought after for resource extraction. In particular, the extraction of oil and gas is increasing throughout the Peruvian Amazon. In the second part of the paper we give some examples of how oil/gas companies and the energy sector in Peru have affected the well-being of the peoples in this reserve in the 21st century. If this trend is not reversed the impacts for isolated peoples will be irreparable.

Napolitano, Dora A.; Ryan, Aliya S. S.

2007-10-01

376

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)

Gas-phase mechanisms provide important oxidant and gaseous precursors for secondary aerosol formation. Different gas-phase mechanisms may lead to different predictions of gases, aerosols, and aerosol direct and indirect effects. In this study, WRF/Chem-MADRID simulations are conducted over the continental United States for July 2001, with three different gas-phase mechanisms, a default one (i.e., CBM-Z) and two newly implemented ones (i.e., CB05 and SAPRC-99). Simulation results are evaluated against available surface observations, satellite data, and reanalysis data. The model with these three gas-phase mechanisms gives similar predictions of most meteorological variables in terms of spatial distribution and statistics, but large differences exist in shortwave radiation and temperature and relative humidity at 2 m at individual sites under cloudy conditions, indicating the importance of aerosol semi-direct and indirect effects on these variables. Large biases exist in the simulated wind speed at 10 m, cloud water path, cloud optical thickness, and precipitation, due to uncertainties in current cloud microphysics and surface layer parameterizations. Simulations with all three gas-phase mechanisms well reproduce surface concentrations of O3, CO, NO2, and PM2.5, and column NO2. Larger biases exist in the surface concentrations of nitrate and organic matter (OM) and in the spatial distribution of column CO, tropospheric ozone residual, and aerosol optical depth, due to uncertainties in primary OM emissions, limitations in model representations of chemical transport, and radiative processes. Different gas-phase mechanisms lead to different predictions of mass concentrations of O3 (up to 5 ppb), PM2.5 (up to 0.5 ?g m-3), secondary inorganic PM2.5 species (up to 1.1 ?g m-3), organic PM (up to 1.8 ?g m-3), and number concentration of PM2.5 (up to 2 × 104 cm-3). Differences in aerosol mass and number concentrations further lead to sizeable differences in simulated 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.

Zhang, Yang; Chen, Yaosheng; Sarwar, Golam; Schere, Kenneth

2012-01-01

377

First controlled sub-seabed CO2 release experiment: Insights into gas migration pathways and impacts on sediment physical properties  

NASA Astrophysics Data System (ADS)

Carbon Capture and Storage (CCS) is a key technology to potentially mitigate global warming by reducing the amount of carbon dioxide (CO2) from industrial facilities and power generation that escapes into the atmosphere. In order to broaden the usage of geological storage as a safe and reliable climate change mitigation option, it is vital to understand CO2 behaviour after its injection within a storage reservoir, including its migration through overlying sediments, as well as its biogeochemical and ecological impacts in the event of leakage at the seafloor. To address these issues, the first controlled CO2 release experiment, entitled 'Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage (QICS)', took place in Ardmucknish Bay, Oban, in May-July 2012. This experiment involved the injection of CO2 of known flux under shallow unconsolidated marine sediments over 36 days and repeated monitoring using geophysical and geochemical techniques. High resolution seismic reflection data (chirp and boomer), covering both pre-release and release stages, allows the detection of various CO2-related anomalies including seismic chimneys, enhanced reflectors within the sediment overburden and bubbles into the overlying water column. CO2 migration pattern is predominantly controlled by the stratigraphy in the early stages of the experiment. However, the increasing flow rate becomes the dominant factor determining CO2 migration, towards the end of the experiment. In addition, analysis of reflection coefficients and seismic attenuation indicates the effect of CO2 on sediment physical properties.

Cevatoglu, M.; Bull, J. M.; Vardy, M. E.; Wright, I. C.; Gernon, T. M.

2013-12-01

378

Integration of Satellite Estimates of Daily Inundation Extent into a Land Surface Ecosystem-Atmosphere Gas Exchange Model: Impacts on Methane Modeling  

NASA Astrophysics Data System (ADS)

Soil moisture and the spatial extent of soil saturation, transient inundation, and wetland ecosystems are key determinants of greenhouse gas (GHG, e.g., methane) emissions from the land surface to the atmosphere. We are investigating how near-daily surface water and soil moisture observations such as those expected from NASA's planned Soil Moisture Active-Passive (SMAP) mission could be integrated into an ecosystem-atmosphere gas exchange model to improve its estimates of GHG fluxes. SMAP, to be launched in November 2014, will combine ~3-km resolution synthetic aperture radar (SAR), ~40-km-resolution L-band radiometry, and 3-day revisit period to make a novel dataset expected to provide inundation and soil moisture estimates superior to alternative methods at that temporal-spatial scale. We test the potential impact of this new data source using the Dynamic Land Surface Ecosystem Model (DLEM). DLEM quantifies regional fluxes of methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) given atmospheric forcing data, with soil saturation as a prognostic variable. In this presentation, we discuss the results of integrating DLEM CH4 emission model products with time-varying subgrid inundation extent estimates from satellite remote sensing observations of North America. To emulate SMAP observations, we have derived a new daily inundation fraction dataset for 2008-2010 using data from NASA's Advanced Microwave Scanning Radiometer-EOS (AMSR-E). To test data-model integration, we created a testbed composed of two separate multi-year DLEM runs in which subgrid land cover conditions were artificially prescribed: one run with maximum wetlands coverage and one with no wetlands. We can combine CH4 products from the two runs using our daily inundation fraction estimates or other inundation representations such that the combination approximates CH4 flux results from a model with explicit inundation forcing. The testbed allows us to simulate a larger array of mixed-grid cases than would be possible with individual model runs explicitly forced by different daily inundation data inputs. Here, we compare CH4 flux results representing two model-data integration realizations: one in which the saturated wetlands coverage is held constant (i.e., representing persistent wetlands) and one in which it is allowed to vary with daily SMAP-like inundation estimates. We show how the impacts of inundation inputs on model CH4 emission vary regionally, seasonally, and year-to-year. We also assess the relative impact on atmospheric CH4 concentration using atmospheric transport results from the Weather Research and Forecasting/Stochastic Time-Inverted Lagrangian Transport (WRF/STILT) Lagrangian particle dispersion model.

Galantowicz, J. F.; Wei, L. H.; Samanta, A.; Picton, J.; Zhang, B.; Lu, C.; Yang, J.; Tian, H.; Eluszkiewicz, J.; Nehrkorn, T.; Mountain, M.

2013-12-01

379

Gulf of Mexico OCS Oil and Gas Lease Sale: 2012. Central Planning Area Lease Sale 216/222. Final Supplemental Environmental Impact Statement. Volume I. Chapters 1-4.  

National Technical Information Service (NTIS)

This Supplemental Environmental Impact Statement (EIS) covers the proposed Gulf of Mexico OCS oil and gas consolidated Lease Sale 216/222 in the Central Planning Area. This Supplemental EIS tiers from the following EISs: the Outer Continental Shelf Oil an...

2012-01-01

380

Updating the lake-atmosphere gas transfer velocity with impacts on the role of lake ecosystems in global carbon cycling  

NASA Astrophysics Data System (ADS)

Currently, the global estimate for the amount of carbon bound in terrestrial ecosystems is 3.0 × 0.9 Pg C y-1 [Le Quéré et al., 2009]. Lakes are not explicitly included in currently used global carbon models [Randall et al., 2007] but it has been estimated that the global net CO2 flux from lakes to the atmosphere range from 0.07 to 0.15 Pg C y-1 [Cole et al., 2007], corresponding to 2.3-5.0% of the total average terrestrial net uptake of carbon. These lake flux estimates may be considerably biased [MacIntyre et al., 2010], since although the data pertain to about 5000 lakes throughout the world [Sobek and Tranvik, 2005], the estimates are not from direct flux measurements. Instead, they are based on surface-water CO2 partial pressure in combination with the gas transfer velocity, k. The uncertainty in the global net CO2 flux is mostly due to the uncertainties in k, which can vary considerably. Cole and Caraco (1998) measured a range of 1.4 to 4.8 cm h-1 for k, but again, these values are not based on direct flux measurements of CO2. The most widely used empirical models of k have wind speed as the only explaining variable. However, the gas transfer velocity is also known to depend on turbulence in the surface water [MacIntyre et al., 2010], which in turn depends mostly on penetrative water convection at low wind conditions [MacIntyre et al., 2010; MacIntyre et al., 2001] - the conditions often prevailing in lakes [Schladow et al., 2002]. We formulated an improved model for k with heat flux parameterization in addition to a wind-speed parameter, determined from an analysis of 4 months (August - November 2011) of continuous high-frequency data in a typical small boreal lake in southern Finland. The CO2 flux from the lake to the atmosphere, atmospheric partial pressure of CO2, and latent and sensible heat were measured with the EC technique installed on a platform. Ancillary measurements included surface-water CO2 concentration and temperature, and net longwave and shortwave radiation. The modeled average k for the whole period, 9.5 cm h-1, was near to the measured average, 8.7 cm h-1. We used 24-hour averages when comparing the results. The new model for k had an R2 value of 0.66 when its performance was compared to the measured gas transfer velocity. Even though this is a lot higher value than when comparing the measured k with a widely used model for k (Cole and Caraco 1998, R2=0.29), the new model could not predict all the sudden changes in k and still roughly one third of the variation was left unexplained. This might be due to the environmental factors omitted by the model, e.g. surfactants. As a result, we showed that the current estimate of the global net CO2 flux from lakes to the atmosphere triples from 0.07-0.15 Pg C y-1 to 0.23-0.48 Pg C y-1 when the average k by Cole and Caraco (1998) is replaced with the new k. This corresponds to 7.5-16.0% of the total CO2 bound in terrestrial ecosystems compared with the current estimates of 2.3-5.0%. The new parameterization of k, assuming that it represents lakes in general, thus shows that the role of lakes in the global carbon cycle has been heavily underestimated and emphasizes the explicit inclusion of lakes in global carbon models.

Heiskanen, J. J.; Mammarella, I.; Haapanala, S.; Vesala, T.; Pumpanen, J. S.; Ojala, A.

2013-12-01

381

Ionization compression impact on dense gas distribution and star formation. Probability density functions around H II regions as seen by Herschel  

NASA Astrophysics Data System (ADS)

Aims: Ionization feedback should impact the probability distribution function (PDF) of the column density of cold dust around the ionized gas. We aim to quantify this effect and discuss its potential link to the core and initial mass function (CMF/IMF). Methods: We used Herschel column density maps of several regions observed within the HOBYS key program in a systematic way: M 16, the Rosette and Vela C molecular clouds, and the RCW 120 H ii region. We computed the PDFs in concentric disks around the main ionizing sources, determined their properties, and discuss the effect of ionization pressure on the distribution of the column density. Results: We fitted the column density PDFs of all clouds with two lognormal distributions, since they present a "double-peak" or an enlarged shape in the PDF. Our interpretation is that the lowest part of the column density distribution describes the turbulent molecular gas, while the second peak corresponds to a compression zone induced by the expansion of the ionized gas into the turbulent molecular cloud. Such a double peak is not visible for all clouds associated with ionization fronts, but it depends on the relative importance of ionization pressure and turbulent ram pressure. A power-law tail is present for higher column densities, which are generally ascribed to the effect of gravity. The condensations at the edge of the ionized gas have a steep compressed radial profile, sometimes recognizable in the flattening of the power-law tail. This could lead to an unambiguous criterion that is able to disentangle triggered star formation from pre-existing star formation. Conclusions: In the context of the gravo-turbulent scenario for the origin of the CMF/IMF, the double-peaked or enlarged shape of the PDF may affect the formation of objects at both the low-mass and the high-mass ends of the CMF/IMF. In particular, a broader PDF is required by the gravo-turbulent scenario to fit the IMF properly with a reasonable initial Mach number for the molecular cloud. Since other physical processes (e.g., the equation of state and the variations among the core properties) have already been said to broaden the PDF, the relative importance of the different effects remains an open question. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Tremblin, P.; Schneider, N.; Minier, V.; Didelon, P.; Hill, T.; Anderson, L. D.; Motte, F.; Zavagno, A.; André, Ph.; Arzoumanian, D.; Audit, E.; Benedettini, M.; Bontemps, S.; Csengeri, T.; Di Francesco, J.; Giannini, T.; Hennemann, M.; Nguyen Luong, Q.; Marston, A. P.; Peretto, N.; Rivera-Ingraham, A.; Russeil, D.; Rygl, K. L. J.; Spinoglio, L.; White, G. J.

2014-04-01

382

The Impact of the Gas Distribution on the Determination of Dynamical Masses of Galaxies Using Unresolved Observations  

NASA Astrophysics Data System (ADS)

Dynamical mass (M dyn) is a key property of any galaxy, yet a determination of M dyn is not straightforward if spatially resolved measurements are not available. This situation occurs in single-dish H I observations of the local universe, but also frequently in high-redshift observations. M dyn measurements in high-redshift galaxies are commonly obtained through observations of the CO line, the most abundant tracer of the molecular medium. Even though in most cases the CO line width can be determined with reasonable accuracy, a measurement of the size of the emitting region is typically challenging given current facilities. We show how the integrated spectra ("global profiles") of a variety of galaxy models depend on the spatial distribution of the tracer gas as well as its velocity dispersion. We demonstrate that the choice of tracer emission line (e.g., H I tracing extended, "flat," emission versus CO tracing more compact, "exponential," emission) significantly affects the shape of the global profiles. In particular, in the case of high (~50 km s-1) velocity dispersions, compact tracers (such as CO) result in Gaussian-like (non-double-horned) profiles, as is indeed frequently seen in high-redshift observations. This leads to significantly different determinations of M dyn if different distributions of the tracer material ("flat" versus "exponential") are considered. We determine at which radii the rotation curve reaches the rotation velocity corresponding to the velocity width, and find that for each tracer this happens at a well-defined radius: H I velocity widths typically originate at ~5 optical scale lengths, while CO velocity widths trace the rotation velocity at ~2 scale lengths. We additionally explore other distributions to take into account that CO distributions at high redshift likely differ from those at low redshift. Our models, while not trying to reproduce individual galaxies, define characteristic radii that can be used in conjunction with the measured velocity widths in order to define dynamical masses consistent with the assumed gas distribution.

de Blok, W. J. G.; Walter, Fabian

2014-05-01

383

Model to investigate energy and greenhouse gas emissions implications of refining petroleum: impacts of crude quality and refinery configuration.  

PubMed

A petroleum refinery model, Petroleum Refinery Life-cycle Inventory Model (PRELIM), which quantifies energy use and greenhouse gas (GHG) emissions with the detail and transparency sufficient to inform policy analysis is developed. PRELIM improves on prior models by representing a more comprehensive range of crude oil quality and refinery configuration, using publicly available information, and supported by refinery operating data and experts' input. The potential use of PRELIM is demonstrated through a scenario analysis to explore the implications of processing crudes of different qualities, with a focus on oil sands products, in different refinery configurations. The variability in GHG emissions estimates resulting from all cases considered in the model application shows differences of up to 14 g CO?eq/MJ of crude, or up to 11 g CO?eq/MJ of gasoline and 19 g CO?eq/MJ of diesel (the margin of deviation in the emissions estimates is roughly 10%). This variability is comparable to the magnitude of upstream emissions and therefore has implications for both policy and mitigation of GHG emissions. PMID:23013493

Abella, Jessica P; Bergerson, Joule A

2012-12-18

384

Impact of recycling on cradle-to-gate energy consumption and greenhouse gas emissions of automotive lithium-ion batteries.  

PubMed

This paper addresses the environmental burdens (energy consumption and air emissions, including greenhouse gases, GHGs) of the material production, assembly, and recycling of automotive lithium-ion batteries in hybrid electric, plug-in hybrid electric, and battery electric vehicles (BEV) that use LiMn(2)O(4) cathode material. In this analysis, we calculated the energy consumed and air emissions generated when recovering LiMn(2)O(4), aluminum, and copper in three recycling processes (hydrometallurgical, intermediate physical, and direct physical recycling) and examined the effect(s) of closed-loop recycling on environmental impacts of battery production. We aimed to develop a U.S.-specific analysis of lithium-ion battery production and in particular sought to resolve literature discrepancies concerning energy consumed during battery assembly. Our analysis takes a process-level (versus a top-down) approach. For a battery used in a BEV, we estimated cradle-to-gate energy and GHG emissions of 75 MJ/kg battery and 5.1 kg CO(2)e/kg battery, respectively. Battery assembly consumes only 6% of this total energy. These results are significantly less than reported in studies that take a top-down approach. We further estimate that direct physical recycling of LiMn(2)O(4), aluminum, and copper in a closed-loop scenario can reduce energy consumption during material production by up to 48%. PMID:23075406

Dunn, Jennifer B; Gaines, Linda; Sullivan, John; Wang, Michael Q

2012-11-20

385

Impact of wildfire emissions on trace gas and aerosol concentration measured at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia  

NASA Astrophysics Data System (ADS)

Boreal wildfires are large sources of reactive trace gases and aerosols to the atmosphere, accounting for 20% of carbon emissions from global biomass burning. Siberian wildfires are a major extratropical source of carbon monoxide (CO), as well as a significant source of black carbon, smoke aerosols, and other climate-relevant atmospheric gas/particle species. Smoke particles released by Siberian wildfires could be tracked thousands of kilometers downwind in the entire Northern Hemisphere, perturbing regional to global radiation budgets by influencing light scattering and cloud microphysical processes. The boreal regions of the Northern Hemisphere are expected to experience the largest temperature increases, which will likely increase the severity and frequency of fires. Consequently, long-term continuous trace gas and aerosol measurements in central Siberia are vital for assessing the atmospheric impact of Siberian boreal fires on regional to global air quality and climate. Since 2006, the Zotino Tall Tower Facility (ZOTTO; www.zottoproject.org), a unique international research platform for large-scale climatic observations, is operational about 20 km west of the Yenisei river (60.8°N; 89.35°E). A 300 m-tall tower allows regular probing of the mixed part of the boundary layer, which is only moderately influenced by diurnal variations of local surface fluxes and thus, in comparison with surface layer, representative for a larger region. Our investigation of the wildfires' impact on surface air composition in Central Siberia is based on four years of CO/CO2/CH4 and aerosol particle mass data measured at 300 m a.g.l.. Episodes of atmospheric transport from wildfires upwind of the measurements site are identified based on ensembles of HYSPLIT backward trajectories and MODIS active fire products. The emission factors are calculated using the Carbon Mass Balance method. In an effort to simplify combustion to its most fundamental principles, the combustion efficiency (CE) is used to represent the completeness of combustion. The following general notion is applied: if the CE exceeds 90 %, a fire is typically in the flaming phase, whereas if CE is less than 85 % combustion is in the smoldering phase. Most fires can be considered as being in a "mixed" phase. Ideally, the emission ratios can be obtained by dividing the excess concentrations of trace gas species measured in a fire plume (e.g. CO, CO2) by the excess concentration of a measured reference gas from the data set. Ground-based CO and CO2 measurements in plumes from relatively distant fires can usually not be used to extract CO/CO2 emission ratios due to the uncertain contributions of biogenic CO2 from respiration to the plume air. We present our attempt to extract CO/CO2 relationships related to sources from statistical analysis of our data set. The burnt biomass load is taken from the Global Land Cover 2000 project and validated by our in situ data set. Finally, episodes of emissions from the wildfires identified at the given location and time are calculated with a simple bottom-up approach using the equation of Seiler and Crutzen.

Panov, A.; Chi, X.; Winderlich, J.; Birmili, W.; Lavri?, J. V.; Andreae, M. O.

2012-04-01

386

Modeling Impacts of Alternative Practices on Net Global Warming Potential and Greenhouse Gas Intensity from Rice-Wheat Annual Rotation in China  

PubMed Central

Background Evaluating the net exchange of greenhouse gas (GHG) emissions in conjunction with soil carbon sequestration may give a comprehensive insight on the role of agricultural production in global warming. Materials and Methods Measured data of methane (CH4) and nitrous oxide (N2O) were utilized to test the applicability of the Denitrification and Decomposition (DNDC) model to a winter wheat – single rice rotation system in southern China. Six alternative scenarios were simulated against the baseline scenario to evaluate their long-term (45-year) impacts on net global warming potential (GWP) and greenhouse gas intensity (GHGI). Principal Results The simulated cumulative CH4 emissions fell within the statistical deviation ranges of the field data, with the exception of N2O emissions during rice-growing season and both gases from the control treatment. Sensitivity tests showed that both CH4 and N2O emissions were significantly affected by changes in both environmental factors and management practices. Compared with the baseline scenario, the long-term simulation had the following results: (1) high straw return and manure amendment scenarios greatly increased CH4 emissions, while other scenarios had similar CH4 emissions, (2) high inorganic N fertilizer increased N2O emissions while manure amendment and reduced inorganic N fertilizer scenarios decreased N2O emissions, (3) the mean annual soil organic carbon sequestration rates (SOCSR) under manure amendment, high straw return, and no-tillage scenarios averaged 0.20 t C ha?1 yr?1, being greater than other scenarios, and (4) the reduced inorganic N fertilizer scenario produced the least N loss from the system, while all the scenarios produced comparable grain yields. Conclusions In terms of net GWP and GHGI for the comprehensive assessment of climate change and crop production, reduced inorganic N fertilizer scenario followed by no-tillage scenario would be advocated for this specified cropping system.

Wang, Jinyang; Zhang, Xiaolin; Liu, Yinglie; Pan, Xiaojian; Liu, Pingli; Chen, Zhaozhi; Huang, Taiqing; Xiong, Zhengqin

2012-01-01

387

Environmental impacts of the expected increase in sea transportation, with a particular focus on oil and gas scenarios for Norway and northwest Russia  

NASA Astrophysics Data System (ADS)

We have complemented existing global sea transportation emission inventories with new regional emission data sets and scenarios for ship traffic and coastal activity in 2015. Emission inventories for 2000 and 2015 are used in a global Chemical Transport Model (CTM) to quantify environmental atmospheric impacts with particular focus on the Arctic region. Although we assume that ship emissions continue to increase from 2000 to 2015, reductions are assumed for some chemical components and regions because of implementation of new regulations. Current ship traffic (2000) is estimated to contribute significantly to coastal pollution. Norwegian coastal ship traffic is responsible for more than 1/3 and 1/6 of the Norwegian NOx and SO2 emissions, respectively. For these short-lived components the impact of Norwegian coastal emissions is regionally important. For most components the international ship transportation outside coastal waters dominates the effects. Ship emissions increase wet deposition in Scandinavia with 30-50% for nitrate and 10-25% for sulfate. In general, coastal regions with prevailing onshore winds show substantial increases in deposition of acid components. Maximum surface increase in ozone is in excess of 10 ppbv. Column ozone increases are also significant. Assuming no changes in nonshipping emissions, scenarios for shipping activities in 2015 lead to more than 20% increase in NO2 from 2000 to 2015 in some coastal areas. Ozone increases are in general small. Wet deposition of acidic species increases up to 10% in areas where current critical loads are exceeded. Regulations limiting the sulfur content in the fuel in the North Sea and English Channel will be an efficient measure to reduce sulfate deposition in nearby coastal regions. The expected oil and gas transport by ships from Norway and northwest Russia, sea transport along the Northern Sea Route and new Norwegian coastal gas power plants will have a significant regional effect by increases of acid deposition in north Scandinavia and the Kola Peninsula. Augmented levels of particles in the Arctic are calculated, and thus the contribution from ship traffic to phenomena like Arctic haze could be increasing.

Dalsøren, Stig B.; Endresen, Øyvind; Isaksen, Ivar S. A.; Gravir, Gjermund; Sørgârd, Eirik

2007-01-01

388

Isolation and characterization of hydrogen-oxidizing bacteria induced following exposure of soil to hydrogen gas and their impact on plant growth.  

PubMed

In many legumes, the nitrogen fixing root nodules produce H2 gas that diffuses into soil. It has been demonstrated that such exposure of soil to H2 can promote plant growth. To assess whether this may be due to H2-oxidizing microorganisms, bacteria were isolated from soil treated with H2 under laboratory conditions and from soils collected adjacent to H2 producing soybean nodules. Nineteen isolates of H2-oxidizing bacteria were obtained and all exhibited a half-saturation coefficient (Ks) for H2 of about 1 ml l(-1). The isolates were identified as Variovorax paradoxus, Flavobacterium johnsoniae and Burkholderia spp. using conventional microbiological tests and 16S rRNA gene sequence analysis. Seventeen of the isolates enhanced (57-254%) root elongation of spring wheat seedlings. Using an Arabidopsis thaliana bioassay, plant biomass was increased by 11-27% when inoculated by one of four isolates of V. paradoxus or one isolate of Burkholderia that were selected for evaluation. The isolates of V. paradoxus found in both H2-treated soil and in soil adjacent to soybean nodules had the greatest impact on plant growth. The results are consistent with the hypothesis that H2-oxidizing bacteria in soils have plant growth promoting properties. PMID:17222141

Maimaiti, Jiamila; Zhang, Ye; Yang, Jing; Cen, Yan-Ping; Layzell, David B; Peoples, Mark; Dong, Zhongmin

2007-02-01

389

Offshore oil & gas markets heating up: Gulf of Mexico rising from `Dead Sea` image; healthy Gulf, North Sea markets combine for big impact  

SciTech Connect

Only three years ago, Gulf of Mexico drilling activity was so moribund that it was termed the Dead Sea. But the market has changed so there is now effectively 100 percent utilization in several important categories of offshore rigs, and almost every type of offshore rig is now getting higher use and better rates. What makes these changes so profound is that few industry participants saw this tightness developing, and almost no one predicted that it would occur so soon. Even the largest offshore contractors were pleasantly surprised as they watched their key drilling markets tighten so uickly after many years of vast oversupply. Today, while neither the Gulf of Mexico nor the North Sea could be described as booming, they are not falling apart either. The combination of both markets merely being normal at the same time has made a big impact on the worldwide supply and demand for offshore drilling. The need for steady and increasing offshore oil and gas production has never been so high. The technology now in place is allowing the development of offshore areas deemed almost impossible less than a decade ago. Also, the vast excess supply of offshore equipment is gone for many forms of drilling, and the need for steadily higher dayrates is real and will merely increase over time.

Simmons, M.R.

1995-09-01

390

Validation of a gas chromatography–mass spectrometry method for the determination of pg\\/ml levels of 17?-estradiol and 17?-trenbolone in bovine serum  

Microsoft Academic Search

A method for the quantitation of pg\\/ml levels of 17?-estradiol and 17?-trenbolone in bovine serum by gas chromatography\\/electron-capture mass spectrometry has been developed and validated. Using the area ratios of the integrated molecular-ion peaks of the analytes to their corresponding deuterated internal standards, [2,4,16,16-2H4] 17?-estradiol (17?-estradiol-d4) and [16,16-2H2] 17?-trenbolone (17?-trenbolone-d2), and non-weighted linear regression, two calibration curves per analyte; 5–50

Rick W. Fedeniuk; Joe O. Boison; James D. MacNeil

2004-01-01

391

Gas Pressure  

NSDL National Science Digital Library

This radio broadcast discusses the boom in natural gas drilling in the Rocky Mountain region and is possible impacts on the environment. A resource advocate points out the issue of well density, which can range from four wells per square mile to sixteen, 32, or more, and results in fragmentation of habitat as well as an ugly industrial appearance. The clip is 2 minutes in length and is available in MP3 format.

Pomplun, Steve

2012-08-06

392

Gas Jets  

NASA Technical Reports Server (NTRS)

A brief summary of the contents of this paper is presented here. In part I the differential equations of the problem of a gas flow in two dimensions is derived and the particular integrals by which the problem on jets is solved are given. Use is made of the same independent variables as Molenbroek used, but it is found to be more suitable to consider other functions. The stream function and velocity potential corresponding to the problem are given in the form of series. The investigation on the convergence of these series in connection with certain properties of the functions entering them forms the subject of part II. In part III the problem of the outflow of a gas from an infinite vessel with plane walls is solved. In part IV the impact of a gas jet on a plate is considered and the limiting case where the jet expands to infinity changing into a gas flow is taken up in more detail. This also solved the equivalent problem of the resistance of a gaseous medium to the motion of a plate. Finally, in part V, an approximate method is presented that permits a simpler solution of the problem of jet flows in the case where the velocities of the gas (velocities of the particles in the gas) are not very large.

Chaplygin, S.

1944-01-01

393

Impact of venous systemic oxygen persufflation supplemented with nitric oxide gas on cold-stored, warm ischemia-damaged experimental liver grafts.  

PubMed

The increasing shortage of donor organs has led to the increasing use of organs from non-heart-beating donors. We aimed to assess the impact of venous systemic oxygen persufflation (VSOP) supplemented with nitric oxide (NO) gas during the cold storage (CS) of warm ischemia (WI)-damaged experimental liver grafts. Rat livers (n = 5 per group) were retrieved after 30 minutes of WI induced by cardiac arrest (the WI group) and were thereafter preserved for 24 hours by CS in histidine tryptophan ketoglutarate solution. During CS, gaseous oxygen was insufflated via the caval vein with 40 ppm NO (the VSOP-NO group) or without NO (the VSOP group). Cold-stored livers without WI served as controls. Liver viability was assessed after the preservation period by normothermic isolated reperfusion for 45 minutes with oxygenated Krebs-Henseleit buffer. After 45 minutes of reperfusion, the VSOP-NO-treated livers showed significantly lower alanine aminotransferase values than the WI-damaged livers (10.2 ± 0.2 versus 78.2 ± 14.6 IU/L), whereas the control livers showed no differences from the VSOP-NO-treated livers. The mitochondrial enzyme release was lower in the VSOP-NO group (4.0 ± 0.7 IU/L) versus the WI group (18.2 ± 4.9 IU/L). An increased portal vein pressure was observed throughout reperfusion (45 minutes) in the WI group (21.7 ± 0.2 mm Hg) versus the VSOP-NO group (12.2 ± 0.8 mm Hg) and the control group (19.9 ± 0.4 mm Hg). Furthermore, the NO concentration in the perfusate after 5 minutes of reperfusion was highest in the VSOP-NO group. The release of malondialdehyde into the perfusate was significantly reduced in the VSOP-NO group (0.9 ± 0.1 nmol/mL) versus the WI group (31.3 ± 5.3 nmol/mL). In conclusion, the resuscitation of livers after 30 minutes of WI to a level comparable to that of nonischemically damaged livers is possible with VSOP supplemented with NO gas. Moreover, the application of VSOP with NO minimizes the extent of injuries caused by oxygen free radicals during preservation. PMID:21987402

Srinivasan, Pramod Kadaba; Yagi, Shintaro; Doorschodt, Benedict; Nagai, Kazuyuki; Afify, Mamdouh; Uemoto, Shinji; Tolba, Rene

2012-02-01

394

Rapid method for quantitative analysis of the aroma impact compound, 2-acetyl-1-pyrroline, in fragrant rice using automated headspace gas chromatography.  

PubMed

A rapid method employing static headspace gas chromatography (HS-GC) has been developed and validated for quantitative analysis of the impact aroma compound, 2-acetyl-1-pyrroline (2AP), in grains of fragrant rice. This developed method excludes wet extraction, and the rice headspace volatiles are brought directly and automatically to GC analysis. The conditions of the static HS autosampler were optimized to achieve high recovery and sensitivity. The most effective amount of rice sample used was 1 g, which provided 51% recovery and a linear multiple headspace extraction (MHE) plot of the peak area of 2AP. The sensitivity of the method was enhanced by utilizing a megabore fused silica capillary column in conjunction with a nitrogen-phosphorus detector (NPD). Method validations performed for both static HS-GC-FID and HS-GC-NPD demonstrated linear calibration ranges of 20-10 000 (r(2) = 0.9997) and 5-8000 (r(2) = 0.9998) ng of 2AP/g of rice sample, respectively. The limits of detection for both systems were 20 and 5 ng of 2AP, and the limits of quantitation were 0.30 and 0.01 g of brown rice sample, respectively. Reproducibility calculated as intraday and interday coefficients of variation were 3.25% RSD (n = 15) and 3.92% RSD (n = 35), respectively, for SHS-GC-FID and 1.87% RSD (n = 15) and 2.85% RSD (n = 35), respectively, for SHS-GC-NPD. The method was found to be effective when applied to the evaluation of aroma quality, based on 2AP concentrations, of some fragrant rice samples. PMID:17032027

Sriseadka, Tinakorn; Wongpornchai, Sugunya; Kitsawatpaiboon, Pisan

2006-10-18

395

TSR versus non-TSR processes and their impact on gas geochemistry and carbon stable isotopes in Carboniferous, Permian and Lower Triassic marine carbonate gas reservoirs in the Eastern Sichuan Basin, China  

NASA Astrophysics Data System (ADS)

The Palaeozoic and lowermost Mesozoic marine carbonate reservoirs of the Sichuan Basin in China contain variably sour and very dry gas. The source of the gas in the Carboniferous, Permian and Lower Triassic reservoirs is not known for certain and it has proved difficult to discriminate and differentiate the effects of thermal cracking- and TSR-related processes for these gases. Sixty-three gas samples were collected and analysed for their composition and carbon stable isotope values. The gases are all typically very dry (alkane gases being >97.5% methane), with low (<1%) nitrogen and highly variable H2S and CO2. Carboniferous gas is negligibly sour while the Lower Triassic gas tends to be most sour. The elevated H2S (up to 62%) is due to thermochemical sulphate reduction with the most sour Triassic and Permian reservoirs being deeper than 4800 m. The non-TSR affected Carboniferous gas is a secondary gas that was derived from the cracking of sapropelic kerogen-derived oil and primary gas and is highly mature. Carboniferous (and non-sour Triassic and Permian) gas has unusual carbon isotopes with methane and propane being isotopically heavier than ethane (a reversal of typical low- to moderate-maturity patterns). The gas in the non-sour Triassic and Permian reservoirs has the same geochemical and isotopic characteristics (and therefore the same source) as the Carboniferous gas. TSR in the deepest Triassic reservoirs altered the gas composition reaching 100% dryness in the deepest, most sour reservoirs showing that ethane and propane react faster than methane during TSR. Ethane evolves to heavier carbon isotope values than methane during TSR leading to removal of the reversed alkane gas isotope trend found in the Carboniferous and non-sour Triassic and Permian reservoirs. However, methane was directly involved in TSR as shown by the progressive increase in its carbon isotope ratio as gas souring proceeded. CO2 increased in concentration as gas souring proceeded, but typical CO2 carbon isotope ratios in sour gases remained about -4‰ V-PDB showing that it was not solely derived from the oxidation of alkanes. Instead CO2 may partly result from reaction of sour gas with carbonate reservoir minerals, such as Fe-rich dolomite or calcite, resulting in pyrite growth as well as CO2-generation.

Liu, Q. Y.; Worden, R. H.; Jin, Z. J.; Liu, W. H.; Li, J.; Gao, B.; Zhang, D. W.; Hu, A. P.; Yang, C.

2013-01-01

396

Improvement of a ``mini'' two-stage light-gas gun for hypervelocity impact experiments: Technical devices to accelerate and detect a ``minute'' projectile efficiently  

Microsoft Academic Search

A gas-gun system was improved and optimized in order to obtain higher projectile velocity. The gas gun used in this study was a ``mini'' two-stage light-gas gun suitable for the acceleration of a ``minute'' projectile. As a major improvement in the mini gun, the high-pressure coupler was divided into two parts. One part was a generation section of the hot

Fumikazu Saito; Toshitika Usui; Hideki Tamura; Yusuke Tanaka; Michiaki Shimizu; Ken-Ichi Kondo

2005-01-01

397

A Measurement System for Interior Projectile Motion and Particle-Velocity Histories for Impact Shock Study with a Two-Stage Light Gas Gun  

Microsoft Academic Search

This system has been developed for the purpose of precise observations of shock-compression states at pressures higher than several 10s of GPa in solids. Plane impact experiments within an impact tilt-angle of 0.2 degrees, in which the impact velocity can be measured within an error of 0.5% by the X-ray beam cut-off method, are made practicable. Particle-velocity histories at two

Tsutomu Mashimo; Akira Sawaoka

1981-01-01

398

A study of the impact of oil and gas development on the Dene First Nations of the Sahtu (Great Bear Lake) Region of the Canadian Northwest Territories (NWT)  

Microsoft Academic Search

Purpose – Beneath Canada's Northwest Territories lies a potential of 30 trillion cubic feet of natural gas. Will a $16 billion gas-pipeline bring prosperity or gloom? Will this bring employment opportunities for local people or will more qualified people be brought in from southern communities? The purpose of this paper is to give an account of what Dene residents of

Leo Paul Dana; Robert Brent Anderson; Aldene Meis-Mason

2009-01-01

399

Impact of the state-of-the-art of flue gas cleaning on mercury species emissions from coal-fired steam generators  

Microsoft Academic Search

When balancing the element mercury (Hg) two coal-fired power plant units — one with slag tap boilers (ST, 2 × 220 MW) and one with a dry bottom boiler (DB, 475 MW) were compared. Both systems are provided with electrostatic precipitators (ESP), nitrogen oxides removal (DeNOx) and flue gas desulfurization (FGD) systems. The Hg in the flue gas is predominantly

J. Fahlke; A. Bursik

1995-01-01

400

Impacts of ratio of asymptotic bubble width to diameter of circular tube and Reynolds number in a gas bubble driven flow  

Microsoft Academic Search

This study investigates the steady-state flow field in a circular tube filled with a viscous fluid expelled by a long gas bubble. We use a finite difference method (FDM) with successive over-relaxation (SOR) in the computation of the viscous fluid flows. An empirical deduced bubble profile is employed to simplify the complex computation of the interface shape between the gas

Cheng-Hsing Hsu; Po-Chuang Chen; Kuang-Yuan Kung; Chuan Lai

2005-01-01

401

Simple Techniques For Assessing Impacts Of Oil And Gas Operations On Public Lands: A Field Evaluation Of A Photoionization Detector (PID) At A Condensate Release Site, Padre Island National Seashore, Texas  

USGS Publications Warehouse

Simple, cost-effective techniques are needed for land managers to assess the environmental impacts of oil and gas production activities on public lands, so that sites may be prioritized for remediation or for further, more formal assessment. Field-portable instruments provide real-time data and allow the field investigator to extend an assessment beyond simply locating and mapping obvious disturbances. Field investigators can examine sites for the presence of hydrocarbons in the subsurface using a soil auger and a photoionization detector (PID). The PID measures volatile organic compounds (VOC) in soil gases. This allows detection of hydrocarbons in the shallow subsurface near areas of obvious oil-stained soils, oil in pits, or dead vegetation. Remnants of a condensate release occur in sandy soils at a production site on the Padre Island National Seashore in south Texas. Dead vegetation had been observed by National Park Service personnel in the release area several years prior to our visit. The site is located several miles south of the Malaquite Beach Campground. In early 2001, we sampled soil gases for VOCs in the area believed to have received the condensate. Our purpose in this investigation was: 1) to establish what sampling techniques might be effective in sandy soils with a shallow water and contrast them with techniques used in an earlier study; and 2) delineate the probable area of condensate release. Our field results show that sealing the auger hole with a clear, rigid plastic tube capped at the top end and sampling the soil gas through a small hole in the cap increases the soil VOC gas signature, compared to sampling soil gases in the bottom of an open hole. This sealed-tube sampling method increases the contrast between the VOC levels within a contaminated area and adjacent background areas. The tube allows the PID air pump to draw soil gas from the volume of soil surrounding the open hole below the tube in a zone less influenced by atmospheric air. In an open hole, the VOC readings seem to be strongly dependent on the degree of diffusion and advection of soil gas VOCs into the open hole from the surrounding soil, a process that may vary with soil and wind conditions. Making measurements with the sealed hole does take some additional time (4-7 minutes after the hole is augered) compared to the open-hole technique (1-2 minutes). We used the rigid-plastic tube technique to survey for soil gas VOCs across the entire site, less than ? acre. Condensate has impacted at least 0.28 acres. The impacted area may extend northwest of the surveyed area.

Otton, James K.; Zielinski, Robert A.

2001-01-01

402

Potential Impacts of two SO2 oxidation pathways on regional sulfate concentrations: acqueous-hase oxidation by NO2 and gas-phase oxidation by Stabilized Criegee Intermediates  

EPA Science Inventory

We examine the potential impacts of two additional sulfate production pathways using the Community Multiscale Air Quality modeling system. First we evaluate the impact of the aqueous-phase oxidation of S(IV) by nitrogen dioxide using two published rate constants, differing by 1-2...

403

Improvement of a ``mini'' two-stage light-gas gun for hypervelocity impact experiments: Technical devices to accelerate and detect a ``minute'' projectile efficiently  

NASA Astrophysics Data System (ADS)

A gas-gun system was improved and optimized in order to obtain higher projectile velocity. The gas gun used in this study was a ``mini'' two-stage light-gas gun suitable for the acceleration of a ``minute'' projectile. As a major improvement in the mini gun, the high-pressure coupler was divided into two parts. One part was a generation section of the hot and high-pressure working gas by compression with a piston, and the other was a flow rate control section of the working gas. The mini gun, after installing the improved high-pressure coupler, showed an increase not only in the projectile velocity but also in the energy efficiency converting the combustion energy to the projectile kinetic energy, compared with the conventional mini gun. In the firing test using hydrogen as a working gas, a projectile velocity of 5.91 km/s was achieved by the use of the improved mini gun, as compared with a velocity of 4.70 km/s before the improvements were made. The modifications to the mini-gun system and their effects on the performance of the mini gun are discussed.

Saito, Fumikazu; Usui, Toshitika; Tamura, Hideki; Tanaka, Yusuke; Shimizu, Michiaki; Kondo, Ken-Ichi

2005-05-01

404

Impact of the Application Technique on Nitrogen Gas Emissions and Nitrogen Budgets in Case of Energy Maize Fertilized with Biogas Residues  

NASA Astrophysics Data System (ADS)

Despite an increasing cultivation of energy maize fertilized with ammonia-rich biogas residues (BR), little is known about the impact of the application technique on gaseous nitrogen (N) losses as well as N budgets, indicative of N use efficiency. To contribute to closing this knowledge gap we conducted a field experiment supplemented by a laboratory incubation study. The field experiment was carried out in Dedelow, located in the Northeastern German Lowlands and characterized by well-drained loamy sand (haplic luvisol). Two treatments with different application technique for BR fertilization - i) trail hoses and ii) injection - were compared to an unfertilized control (0% N). Seventy percent of the applied N-BR was assumed to be plant-available. In 2013, biweekly nitrous oxide (N2O) measurements were conducted during the time period between BR application and maize harvest (18.04.-11.09.2013; 147 days) using non-flow-through non-steady-state chamber measurements. To quantify soil Nmin status, soil samples were taken from 0-30 cm soil depth in the spring (before fertilization) and autumn (after maize harvest). Immediately after BR application, ammonia (NH3) volatilization was measured intensively using the open dynamic chamber Dräger-Tube method. Export of N due to harvest was determined via plant N content (Nharvest). Based on the measured N gas fluxes, N soil and plant parameters, soil N budgets were calculated using a simple difference approach. Values of N output (Nharvest, NN2O_cum and NNH3_cum) are subtracted from N input values (Nfertilizer and Nmin_autumnminus Nmin_spring). In order to correctly interpret N budgets, other N fluxes must be integrated into the budget calculation. Apart from soil-based mobilization and immobilization turnover processes and nitrate leaching, this applies specifically to N2 losses due to denitrification. Therefore, we measured the N2 emissions from laboratory-incubated undisturbed soil cores (250 cm3) by means of the helium incubation approach. With cumulative field emissions of 2.9±0.8 kg N2O-N ha-1 and 3.9±0.4 kg N2O-N ha-1 after trail hose application and injection, respectively, our results showed no clear application effect. NH3-N losses were higher for trail hose application (7.2 kg NH3-N ha-1) compared to injection (5.2 kg NH3-N ha-1). The calculated N budgets showed negative values (accumulative deficit) up to -6 kg N ha-1 and -32 kg N ha-1 for trail hose application and injection, respectively. But differences between treatments were not significant. Overall N budgets were more influenced by plant N uptake (91-96%) than by gaseous N losses (4-9%). However, results from the laboratory incubation indicate that N2 may also be a potentially important pathway of N loss, contributing to 34% of total gaseous N loss, corresponding to 5 kg N2-N ha-1 yr-1.

Andres, Monique; Fränzke, Manuel; Schuster, Carola; Kreuter, Thomas; Augustin, Jürgen

2014-05-01

405

Life-cycle analysis of shale gas and natural gas  

Microsoft Academic Search

The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for

C. E. Clark; J. Han; A. Burnham; J. B. Dunn; M. Wang

2012-01-01

406