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1

Systematic characterisation of long-chain aliphatic esters of wool wax by gas chromatography–electron impact ionisation mass spectrometry  

Microsoft Academic Search

A detailed structural characterisation of the aliphatic high-molecular-mass esters extracted from raw wool based on high-temperature gas chromatography–electron impact ionisation mass spectrometry is described. The raw wool esters extracted are in the range of C37 to C54 (i.e., molecular mass 550–788). The selected ion chromatogram exhibited four isomers for the esters with an odd number of carbon atoms (i:a, i:n,

Zaharie Moldovan; Eric Jover; José Maria Bayona

2002-01-01

2

Simultaneous quantification of tramadol and O-desmethyltramadol in hair samples by gas chromatography-electron impact/mass spectrometry.  

PubMed

Over recent years, hair has become the ideal matrix for retrospective investigation of chronic abuse, including for tramadol. However, in order to exclude the possibility of external contamination, it is also important to quantify simultaneously its main metabolite, O-desmethyltramadol (M1), which presence in hair reflects systemic exposure. In the present study a methodology aimed at the simultaneous quantification of tramadol and M1 in human hair was developed and validated for the first time. After decontamination of hair samples (60 mg), tramadol and M1 were extracted with methanol in an ultrasonic bath (~5 h). Purification was performed by solid-phase extraction using mixed-mode extraction cartridges. Subsequently to derivatization, analysis was performed by gas chromatography-electron impact/mass spectrometry (GC-EI/MS). The method proved to be selective. The regression analysis for both analytes was shown to be linear in the range of 0.1-20.0 ng/mg with correlation coefficients of 0.9995 and 0.9997 for tramadol and M1, respectively. The coefficients of variation oscillated between 3.85 and 13.24%. The limits of detection were 0.03 and 0.02 ng/mg, and the lower limits of quantification were 0.08 and 0.06 ng/mg for tramadol and M1, respectively. The proof of applicability was performed in hair samples from six patients undergoing tramadol therapy. All samples were positive for tramadol and M1. PMID:23519701

Pinho, Sandra; Oliveira, Ana; Costa, Isabel; Gouveia, Carla Alexandra; Carvalho, Félix; Moreira, Roxana Falcão; Dinis-Oliveira, Ricardo Jorge

2013-03-21

3

Determination of melatonin in pharmaceutical formulations and human plasma by gas chromatography-electron impact mass spectrometry.  

PubMed

A simple and reliable method for gas chromatography-mass spectrometry (GC-MS) has been developed for the determination of melatonin in commercially available tablet formulations and human plasma. The dissolution of the tablets in ethyl acetate was simply obtained by sonication. The filtrate of the resultant solution, after concentration, was derivatized with pentafluoropropionic anhydride (PFPA) and analysed by GC-MS using splitless injection. The linear response range for melatonin was 5-250 ng on column. The same method can be used, with minor modifications, for the determination of melatonin in spiked human plasma in the range 50-1000 pg/mL plasma. PMID:10477902

Covaci, A; Doneanu, C; Aboul-Enein, H Y; Schepens, P

1999-10-01

4

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...

5

Identification and quantification of lignans in wheat bran by gas chromatography-electron capture detection.  

PubMed

Whole grain cereals are an important source of bioavailable lignans, the group of compounds with potential anti-cancerogenic, antioxidant, anti-proliferative, pro-apoptotic, and antiangiogenic properties. The aim of this work was to develop a sensitive method for determination of wheat bran lignans. The analysis of lignans secoisolariciresinol, hydroxymatairesinol, lariciresinol, matairesinol, pinoresinol, syringaresinol is based on derivatization with pentafluoropropionic anhydride (PFPA) and gas chromatography-electron capture detection (GC-ECD), using styrene glycol as internal standard. To our knowledge, this is the first time that EC detection has been used for lignan analysis. The results show that the technique is reproducible and sensitive enough for detecting lignans in wheat at parts-per-billion (ppb) levels, except for hydroxymatairesinol. The method developed showed good recovery (85-105%) and precision (4-20%) for five types of lignans and thus represents a simpler and more affordable alternative to state-of-the-art wheat lignan liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. PMID:21315909

Cukelj, Nikolina; Jakasa, Ivone; Sarajlija, Hrvoje; Novotni, Dubravka; Curi?, Duška

2010-12-25

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

Extraction and Gas Chromatography\\/Electron Capture Analysis of Polychlorinated Biphenyls in Railcar Paint Scrapings  

Microsoft Academic Search

Polychlorinated biphenyls (PCBs) in dried paints may present an occupational exposure hazard to maintenance workers and welders who are unaware of their past use in specialized metal coatings. Prior to their restriction to closed systems in 1970, PCBs were routinely added to these paints to impart properties of heat resistance, plasticity, and antifouling. Gas chromatography with electron capture detection was

Michael S. Welsh

1995-01-01

8

Application of pentafluorophenyldimethylsilyl derivatization for gas chromatography–electron-capture detection of supercritically extracted sterols  

Microsoft Academic Search

We report a convenient method of extracting and detecting sterols in environmental water samples. Particle-associated sterols were extracted onto glass-fibre filters then the filters were supercritical fluid extracted (at 33 MPa, 80°C for 30 min) followed by pentafluorophenyldimethylsilyl (flophemesyl) derivatization for gas chromatographic–electron-capture detection (GC–ECD). Optimal derivatization of epicoprostanol, coprostanol, cholesterol, dihydrocholesterol, stigmasterol, ?-sitosterol and stigmastanol with neat flophemesyl chloride

Leonard Y Jayasinghe; Philip J Marriott; Peter D Carpenter; Peter D Nichols

1998-01-01

9

Identification and quantification of lignans in wheat bran by gas chromatography-electron capture detection  

Microsoft Academic Search

Whole grain cereals are an important source of bioavailable lignans, the group of compounds with potential anti-cancerogenic, antioxidant, anti-proliferative, pro-apoptotic, and antiangiogenic properties. The aim of this work was to develop a sensitive method for determination of wheat bran lignans. The analysis of lignans secoisolariciresinol, hydroxymatairesinol, lariciresinol, matairesinol, pinoresinol, syringaresinol is based on derivatization with pentafluoropropionic anhydride (PFPA) and gas

Nikolina ?ukelj; Ivone Jakasa; Hrvoje Sarajlija; Dubravka Novotni; Duška ?uri?

2011-01-01

10

PARTICLE BEAM LIQUID CHROMATOGRAPHY-ELECTRON IMPACT MASS SPECTROMETRY OF DYES  

EPA Science Inventory

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

11

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 0.002ng. 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 19.17ngg(-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

2013-09-06

12

Part-per-trillion determination of chlorobenzenes in water using dispersive liquid–liquid microextraction combined gas chromatography–electron capture detection  

Microsoft Academic Search

In this study, a simple, rapid and efficient method, dispersive liquid–liquid microextraction (DLLME) combined gas chromatography–electron capture detection (GC–ECD), for the determination of chlorobenzenes (CBs) in water samples, has been described. This method involves the use of an appropriate mixture of extraction solvent (9.5?l chlorobenzene) and disperser solvent (0.50ml acetone) for the formation of cloudy solution in 5.00ml aqueous sample

Reyhaneh Rahnama Kozani; Yaghoub Assadi; Farzaneh Shemirani; Mohammad-Reza Milani Hosseini; Mohammad Reza Jamali

2007-01-01

13

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

14

Analysis of 5-methoxytryptamine at the femtomole level in the rat and quail brain by gas chromatography-electron-capture negative-ion chemical ionization mass spectrometry.  

PubMed

A sensitive method for the measurement of endogenous 5-methoxytryptamine in brain tissue has been developed using capillary column gas chromatography-electron-capture negative-ion chemical ionization mass spectrometry. 5-Methoxytryptamine was first converted to N-[2H3]acetyl-5-methoxytryptamine by reaction with hexa-deuterated acetic anhydride, followed by reaction with pentafluoropropionic anhydride to yield the highly electron-capturing 3,3'-spirocyclic pentafluoro-propionyl indolenine derivative. Quantitative analysis was carried out by selected-ion monitoring of the [M-HF].- and [M-HF-DF].- ion intensity of the 3.3'-spirocyclic pentafluoropropionyl indolenine derivative, using 5-methoxy-[alpha, alpha, beta, beta-2H4]tryptamine as the internal standard. The presence of 5-methoxytryptamine in the brain tissue was demonstrated. In the absence of a monoamine oxidase inhibitor, the mean +/- S.D. levels of 5-methoxytryptamine in the rat and quail whole brain were found to be 30 +/- 6 and 347 +/- 52 pg/g, respectively. The possible physiological functions of 5-methoxytryptamine as a neuromodulator and/or neurotransmitter have to be considered. PMID:8844409

Tsang, C W; Chan, C L; Li, P; Pang, S F

1996-07-12

15

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

16

Gas chromatography electron ionization mass spectrometric analysis of O-alkyl methylphosphinates for verification of Chemical Weapons Convention.  

PubMed

We describe the gas chromatography/mass spectrometric (GC/MS) analysis of O-alkyl methylphosphinates (AMPs), which are included in schedule 2B4 chemicals in the Chemical Weapons Convention (CWC). GC/MS analysis of variety of AMPs and their deuterated analogues revealed that their fragmentations were determined by alpha-cleavages, McLafferty +1 and hydrogen rearrangements. Based on the obtained electron ionization mass spectra of AMPs the fragmentation routes were rationalized, which were substantiated by the GC/MS analysis of deuterated analogues. PMID:19679938

Pardasani, Deepak; Kanaujia, Pankaj K; Tak, Vijay; Garg, Prabhat; Mazumder, Avik; Dubey, Devendra K

2009-01-01

17

Improving quantitative gas chromatography-electron ionization mass spectrometry results using a modified ion source: demonstration for a pharmaceutical application.  

PubMed

Gas chromatography-mass spectrometry is a well established analytical technique. However, mass spectrometers with electron ionization sources may suffer from signal drifts, hereby negatively influencing quantitative performance. To demonstrate this phenomenon for a real application, a static headspace-gas chromatography method in combination with electron ionization-quadrupole mass spectrometry was optimized for the determination of residual dichloromethane in coronary stent coatings. Validating the method, the quantitative performance of an original stainless steel ion source was compared to that of a modified ion source. Ion source modification included the application of a gold coating on the repeller and exit plate. Several validation aspects such as limit of detection, limit of quantification, linearity and precision were evaluated using both ion sources. It was found that, as expected, the stainless steel ion source suffered from signal drift. As a consequence, non-linearity and high RSD values for repeated analyses were obtained. An additional experiment was performed to check whether an internal standard compound would lead to better results. It was found that the signal drift patterns of the analyte and internal standard were different, consequently leading to high RSD values for the response factor. With the modified ion source however, a more stable signal was observed resulting in acceptable linearity and precision. Moreover, it was also found that sensitivity improved compared to the stainless steel ion source. Finally, the optimized method with the modified ion source was applied to determine residual dichloromethane in the coating of coronary stents. The solvent was detected but found to be below the limit of quantification. PMID:21620408

D'Autry, Ward; Wolfs, Kris; Hoogmartens, Jos; Adams, Erwin; Van Schepdael, Ann

2011-05-14

18

Analysis of corky off-flavour compounds at ultra trace level with multidimensional gas chromatography-electron capture detection.  

PubMed

A robust method for routine quality control of corky off-flavour compounds in wine and cork soak matrices has been established. Based on an automated headspace solid phase microextraction (HS-SPME), the method needs only marginal sample preparation and achieves low (sub-ng L(-1)) trace level detection limits (LODs) for the most relevant off-flavour compounds, such as 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA) and 2,4,6-tribromoanisole (TBA). Particularly for wine matrix, reliable trace level quantification had only been achieved after applying heart-cutting multidimensional gas chromatography (MDGC). Using a halogen-sensitive electron capture detector (ECD) and quantification with a stable isotope dilution assay (SIDA), LODs of 0.1ng L(-1) for TCA, TeCA and TBA could be obtained. Since a SIDA based quantification method is used with a non-mass spectrometric detector, the necessary chromatographic resolution of internal standard and target analyte peaks resulted from the use of highly deuterated [(2)H(5)]-isotopologues. PMID:23219330

Slabizki, Petra; Schmarr, Hans-Georg

2012-11-19

19

Simultaneous determination of amitraz and its metabolite residue in food animal tissues by gas chromatography-electron capture detector and gas chromatography-mass spectrometry with accelerated solvent extraction.  

PubMed

A new method has been developed for determination and confirmation of amitraz and its main metabolite, 2,4-dimethylaniline, in food animal tissues using gas chromatography-electron capture detector (GC-ECD) and gas chromatography-mass spectrometry detector (GC-MS). This method is based on a new extraction procedure using accelerated solvent extraction (ASE). It consists of an n-hexane/methanol extraction step, a cleaning-up step by BakerBond octadecyl C(18) silica bonded cartridge, hydrolysis and derivatization to 2,4-dimethyl-7-F-butyramide for GC-ECD analysis. For confirmation using GC-MS, hydrolysis and derivatization were not needed. Parameters for extraction pressure, temperature and cycle of ASE, clean-up, derivatization and analysis procedure have been optimized. Spike recoveries from 50 to 300 microg/kg levels were found to be between 72.4 and 101.3% with relative standard deviation less than 11.5% in GC-ECD, from 5 to 20 microg/kg levels were found to be between 77.4 and 107.1% with relative standard deviation less than 11.6% in GC-MS. The LOD and LOQ are 5 and 10 microg/kg, respectively, for these two analytes using GC-ECD. For GC-MS, LOD and LOQ were 2 and 5 microg/kg, respectively. The rapid and reliable method can be used for characterization and quantification of residues of amitraz and its main metabolite, 2,4-dimethylaniline, in liver and kidney samples of swine, sheep and bovine. PMID:20554255

Yu, Huan; Tao, Yanfei; Le, Tao; Chen, Dongmei; Ishsan, Awais; Liu, Yu; Wang, Yulian; Yuan, Zonghui

2010-04-29

20

Optimized cleanup method for the determination of short chain polychlorinated n-alkanes in sediments by high resolution gas chromatography/electron capture negative ion-low resolution mass spectrometry.  

PubMed

The performances of three adsorbents, i.e. silica gel, neutral and basic alumina, in the separation of short chain polychlorinated n-alkanes (sPCAs) from potential interfering substances such as polychlorinated biphenyls (PCBs) and organochlorine pesticides were evaluated. To increase the cleanup efficiency, a two-step cleanup method using silica gel column and subsequent basic alumina column was developed. All the PCB and organochlorine pesticides could be removed by this cleanup method. The very satisfying cleanup efficiency of sPCAs has been achieved and the recovery in the cleanup method reached 92.7%. The method detection limit (MDL) for sPCAs in sediments was determined to be 14 ng g(-1). Relative standard deviation (R.S.D.) of 5.3% was obtained for the mass fraction of sPCAs by analyzing four replicates of a spiked sediment sample. High resolution gas chromatography/electron capture negative ion-low resolution mass spectrometry (HRGC/ECNI-LRMS) was used for sPCAs quantification by monitoring [M-HCl](-) ions. When applied to the sediment samples from the mouth of the Daliao River, the optimized cleanup method in conjunction with HRGC/ECNI-LRMS allowed for highly selective identifications for sPCAs. The sPCAs levels in sediment samples are reported to range from 53.6 ng g(-1) to 289.3 ng g(-1). C(10)- and C(11)-PCAs are the dominant residue in most of investigated sediment samples. PMID:21889633

Gao, Yuan; Zhang, Haijun; Chen, Jiping; Zhang, Qing; Tian, Yuzeng; Qi, Peipei; Yu, Zhengkun

2011-08-03

21

Homogeneous liquid–liquid extraction combined with gas chromatography–electron capture detector for the determination of three pesticide residues in soils  

Microsoft Academic Search

In this study, a new method was developed for analyzing malathion, cypermethrin and lambda-cyhalothrin from soil samples by using homogeneous liquid–liquid extraction (HLLE) and gas chromatography with electron capture detector (GC–ECD). Acetone was used as extraction solvent for the extraction of target pesticides from soil samples. When the extraction process was finished, the target analytes in the extraction solvent were

Xuedong Wang; Xinna Zhao; Xiujuan Liu; Yanyan Li; Lingyan Fu; Jia Hu; Changjiang Huang

2008-01-01

22

Microsynthesis and gas chromatography/electron ionization mass spectrometric and tandem mass spectrometric analysis of cyclic alkylphosphonates for verification of the Chemical Weapons Convention.  

PubMed

We describe the microsynthesis and gas chromatography/mass spectrometric (GC/MS) analysis of cyclic alkylphosphonates (CAPs), which are included in schedule 2B4 chemicals in the Chemical Weapons Convention (CWC). The reported microsynthesis is efficient in comparison with traditional synthesis. GC/MS and GC/tandem mass spectrometric (MS/MS) analysis of a variety of CAPs revealed that their fragmentations were dominated by alpha-cleavages, alkene eliminations and hydrogen rearrangements. Based on the obtained mass spectra and precursor and product ion analysis of five-, six- and seven-membered cyclic alkylphosphonates, the proposed fragmentation routes rationalize most of the characteristic ions. PMID:18636421

Dubey, Devendra K; Pardasani, Deepak; Kanaujia, Pankaj K; Tak, Vijay; Gupta, Hemendra K

2008-08-01

23

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

2012-10-02

24

Sample pretreatment optimization for the analysis of short chain chlorinated paraffins in soil with gas chromatography-electron capture negative ion-mass spectrometry.  

PubMed

Accurately quantifying short chain chlorinated paraffins (SCCPs) in soil samples with gas chromatograph coupled with electron capture negative ionization mass spectrometry (GC-ECNI-MS) is difficult because many other polychlorinated pollutants are present in the sample matrices. These pollutants (e.g., polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and toxaphene) can cause serious interferences during SCCPs analysis with GC-MS. Four main columns packed with different adsorbents, including silica gel, Florisil and alumina, were investigated in this study to determine their performance for separating interfering pollutants from SCCPs. These experimental results suggest that the optimum cleanup procedure uses a silica gel column and a multilayer silica gel-Florisil composite column. This procedure completely separated 22 PCB congeners, 23 OCPs and three toxaphene congeners from SCCPs. However, p,p'-DDD, cis-nonachlor and o,p'-DDD were not completely removed and only 53% of the total toxaphene was removed. This optimized method was successfully and effectively applied for removing interfering pollutants from real soil samples. SCCPs in 17 soil samples from different land use areas within a suburban region were analyzed with the established method. The concentrations of SCCPs in these samples were between 7 and 541 ng g(-1) (mean: 84 ng g(-1)). Similar homologue SCCPs patterns were observed between the soil samples collected from different land use areas. In addition, lower chlorinated (Cl(6/7)) C(10)- and C(11)- SCCPs were the dominant congeners. PMID:23287694

Chen, Laiguo; Huang, Yumei; Han, Shuang; Feng, Yongbin; Jiang, Guo; Tang, Caiming; Ye, Zhixiang; Zhan, Wei; Liu, Ming; Zhang, Sukun

2012-12-13

25

Validated semiquantitative/quantitative screening of 51 drugs in whole blood as silylated derivatives by gas chromatography-selected ion monitoring mass spectrometry and gas chromatography electron capture detection.  

PubMed

A comprehensively validated procedure is presented for simultaneous semiquantitative/quantitative screening of 51 drugs of abuse or drugs potentially hazardous for traffic safety in serum, plasma or whole blood. Benzodiazepines (12), cannabinoids (3), opioids (8), cocaine, antidepressants (13), antipsychotics (5) and antiepileptics (2) as well as zolpidem, zaleplon, zopiclone, meprobamate, carisoprodol, tizanidine and orphenadrine and internal standard flurazepam, were isolated by high-yield liquid-liquid extraction (LLE). The dried extracts were derivatized by two-step silylation and analyzed by the combination of two different gas chromatographic (GC) separations with both electron capture detection (ECD) and mass spectrometry (MS) operating in a selected ion-monitoring (SIM) mode. Quantitative or semiquantitative results were obtained for each substance based on four-point calibration. In the validation tests, accuracy, reproducibility, linearity, limit of detection (LOD) and limit of quantitation (LOQ), selectivity, as well as extraction efficiency and stability of standard stock solutions were tested, and derivatization was optimized in detail. Intra- and inter-day precisions were within 2.5-21.8 and 6.0-22.5%, and square of correlation coefficients of linearity ranged from 0.9896 to 0.9999. The limit of quantitation (LOQ) varied from 2 to 2000 ng/ml due to a variety of the relevant concentrations of the analyzed substances in blood. The method is feasible for highly sensitive, reliable and possibly routinely performed clinical and forensic toxicological analyses. PMID:15171931

Gunnar, Teemu; Mykkänen, Sirpa; Ariniemi, Kari; Lillsunde, Pirjo

2004-07-01

26

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

27

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

28

Future impact on natural gas pipelines  

Microsoft Academic Search

The future for natural gas pipelines is forecast by examining the sources and uses of energy today and projecting respective changes. No significant changes are expected over the next 20 yr in natural gas usage, but regionally, some demand shift could impact certain gas transmission facilities. The conclusion is that natural gas will continue to displace oil in some stationary

Croom

1982-01-01

29

Solar-gas systems impact analysis study  

NASA Astrophysics Data System (ADS)

The impacts of solar/gas technologies on gas consumers and on gas utilities were 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 sand distribution companies. It is shown 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 ion a qualitative fashion. A decision framework for analyzing the type and level of utility involvement in solar/gas technologies was developed.

Neill, C. P.; Hahn, E. F.; Loose, J. C.; Poe, T. E.; Hirshberg, A. S.; Haas, S.; Preble, B.; Halpin, J.

1984-07-01

30

Impact of gas composition on natural gas storage by adsorption  

Microsoft Academic Search

Adsorption storage is the most promising low-pressure alternative for storing natural gas, but some operational difficulties hinder the success of this technology. From a modeling perspective, this article addresses the impact of gas composition on the cyclic behavior of adsorptive natural gas storage systems. The cyclic operation of an onboard storage reservoir is modeled as a series of consecutive two-step

José P. B. Mota

1999-01-01

31

NPS Gas Gun for Planar Impact Studies  

Microsoft Academic Search

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

Chien Cheong Ho; Robert Hixson

2009-01-01

32

Assessing the greenhouse impact of natural gas  

NASA Astrophysics Data System (ADS)

The global warming impact of substituting natural gas for coal and oil is currently in debate. We address this question here by comparing the reduction of greenhouse warming that would result from substituting gas for coal and some oil to the reduction which could be achieved by instead substituting zero carbon energy sources. We show that substitution of natural gas reduces global warming by 40% of that which could be attained by the substitution of zero carbon energy sources. At methane leakage rates that are ˜1% of production, which is similar to today's probable leakage rate of ˜1.5% of production, the 40% benefit is realized as gas substitution occurs. For short transitions the leakage rate must be more than 10 to 15% of production for gas substitution not to reduce warming, and for longer transitions the leakage must be much greater. But even if the leakage was so high that the substitution was not of immediate benefit, the 40%-of-zero-carbon benefit would be realized shortly after methane emissions ceased because methane is removed quickly from the atmosphere whereas CO2 is not. The benefits of substitution are unaffected by heat exchange to the ocean. CO2 emissions are the key to anthropogenic climate change, and substituting gas reduces them by 40% of that possible by conversion to zero carbon energy sources. Gas substitution also reduces the rate at which zero carbon energy sources must eventually be introduced.

Cathles, L. M.

2012-06-01

33

Environmental impacts of natural gas distribution networks within urban neighborhoods  

Microsoft Academic Search

This study uses the life cycle assessment methodology to analyze the type and origin of environmental impacts related to natural gas distribution networks in high and low density neighborhoods, and compares the environmental performance of two infrastructures in low density neighborhoods: a standard natural gas grid and a discontinuous system based on propane tanks. The results show that the impact

Jordi Oliver-Solà; Xavier Gabarrell; Joan Rieradevall

2009-01-01

34

Impact of rising taxes on natural gas prices since 1973  

Microsoft Academic Search

Since the early 1970s, tax increases imposed on the gas industry by all levels of government have had a large impact on the price of natural gas paid by US consumers. In 1973, the tax component was 15 cents\\/1000 CF or 19% of the average cost of providing gas service; by 1979, this component had risen to 54 cents\\/1000 CF

1981-01-01

35

Evaluating Local-National Impacts from Landing Statfjord Gas.  

National Technical Information Service (NTIS)

The study provides estimates of local economic change at two proposed Norwegian sites for landing North Sea Gas. A framework is created and described for making local impact assesments. Local changes are linked to national issues and unique national conce...

R. E. Shaffer D. W. Fischer

1981-01-01

36

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...

37

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

38

Impact of globalization of the natural gas market on natural gas prices in power generation and energy development  

Microsoft Academic Search

The development of liquefied natural gas (LNG) infrastructure that allows natural gas to be exported from gas producing regions to gas consuming regions is transforming previously regional gas markets into a global market. The panel will address the impacts of this globalization on the power generation industry that has been increasingly turning to natural gas fueled plants. Panelists from major

Tom Hammons; R. Johnson; B. Blyden

2008-01-01

39

Review of oil and gas exploitation impacts on grizzly bears  

Microsoft Academic Search

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

ALLEN SCHALLENBERGER

1980-01-01

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

TRIDENT flyer plate Impact technique: comparison to gas gun plate; impact technique  

Microsoft Academic Search

This report describes the details of a series of plate impact experiments that were;\\u000aconducted on a gas gun in an effort to validate a new technique for plate impact;\\u000ausing the TRIDENT laser to launch thin flyers. The diagnostics fielded were;\\u000aVISAR and identical samples and impactors were used on both platforms. All;\\u000aexperimenters agree that the VISAR results

Darcie D. Koller; George T. Gray; Sheng-Nian Luo

2009-01-01

42

Impact Response of a Gas-Bearing Supported Rotor  

Microsoft Academic Search

Data are reported for two rotors (1.44 and 5.88 pounds) supported by externally pressurized gas bearings. Comparative plots show that the effective spring rate for synchronous whirl (a function of pressure) also serves to account for the shaft displacement under gravity load and under low-frequency impact loading. Exceptions are noted at the half-speed whirl threshold and at low speed and

Ralph A. Burton; Herbert J. Carper

1965-01-01

43

67 FR 50453 - Draft Environmental Impact Statement for the Swanson River Satellites Natural Gas Exploration and...  

Federal Register 2010, 2011, 2012, 2013

...impacts of constructing natural gas exploration and production...existing Swanson River oil and gas field. The...INFORMATION: Union Oil Company of California...and production of natural gas resources within...The subsurface oil, gas, and coal...Unocal has leased the natural gas development...

2002-08-02

44

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

PubMed Central

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

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

2009-01-01

45

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

46

Impact damage on shielded gas-filled vessels  

NASA Astrophysics Data System (ADS)

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

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

2001-10-01

47

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

SciTech Connect

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

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

2009-03-01

48

Norwegian Gas Sales and the Impacts on European CO2 Emissions  

Microsoft Academic Search

This paper studies the impacts on Western European CO2 emissions of a reduction in Norwegian gas sales. The impacts are due to changes in energy demand and energy supply, but environmental and political regulations also play an important role. The gas supply model DYNOPOLY is used to analyse the effects on Russian and Algerian gas exports of a reduction in

1997-01-01

49

Tropospheric aerosol impacts on trace gas budgets through photolysis  

NASA Astrophysics Data System (ADS)

Aerosols affect the global budgets of O3, OH, and CH4 in part through their alteration of photolysis rates and in part through their direct chemical interactions with gases (i.e., "heterogeneous chemistry"). The first effect is evaluated here with a global tropospheric chemistry transport model using recently developed global climatologies of tropospheric aerosols: a satellite-derived aerosol climatology over the oceans by advanced very high resolution radiometer and a model-generated climatology for land plus oceans by the Center for Climate System Research. Globally averaged, the impact of aerosols on photolysis alone is to increase tropospheric O3 by 0.63 Dobson units and increase tropospheric CH4 by 130 ppb (via tropospheric OH decreases of 8%). These greenhouse gas increases lead to an aerosol indirect effect (counting both natural and anthropogenic aerosols) of +0.08 W/m2. Although the CH4 increases are, of course, global, the changes in tropospheric OH and O3 are mainly regional, with the largest impacts in northwest Africa for January and in India and southern Africa for July. The influence of aerosols is greater in July than in January and greater in the Northern Hemisphere than in the Southern Hemisphere, as expected given the pollution sources in the Northern Hemisphere. The predominant impact is due to the aerosols over land; aerosols over the ocean contribute less than a third to globally integrated changes.

Bian, Huisheng; Prather, Michael J.; Takemura, Toshihiko

2003-04-01

50

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

Federal Register 2010, 2011, 2012, 2013

...Commission [Docket No. CP13-73-000] Sierrita Gas Pipeline LLC; Supplemental Notice...Environmental Impact Statement for the Sierrita Pipeline Project and Request for Comments...discuss the environmental impact of the Sierrita Pipeline Project (Project)...

2013-04-19

51

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

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

The impact of natural gas competition on residual fuel oils  

Microsoft Academic Search

The instability in gas markets and loss of sales to oil that have been evident so far are only the beginning of what threatens to be a major shift from gas to residual fuel oil unless pipelines can lower their gas costs. As a result, refiners who have invested heavily in bottom-of-the-barrel processing technology may well see their margins shrink.

M. Kelly; J. N. McCutchen

1984-01-01

54

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

55

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

SciTech Connect

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

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

1993-12-01

56

Impact design methods for ceramic components in gas turbine engines  

Microsoft Academic Search

Garrett Auxiliary Power Division of Allied-Signal Aerospace Company is developing methods to design ceramic turbine components with improved impact resistance. In an ongoing research effort under the DOE\\/NASA-funded Advanced Turbine Technology Applications Project (ATTAP), two different modes of impact damage have been identified and characterized: local damage and structural damage. Local impact damage to Si[sub 3]N[sub 4] impacted by spherical

J. Song; J. Cuccio; H. Kington

1993-01-01

57

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

58

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 ...

59

Advanced Diagnostics for Impact-Flash Spectroscopy on Light-Gas Guns.  

National Technical Information Service (NTIS)

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...

M. C. Wanke A. D. Grine M. A. Mangan L. C. Chhabildas W. D. Reinhart

2007-01-01

60

Impact design methods for ceramic components in gas turbine engines  

SciTech Connect

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

Song, J.; Cuccio, J.; Kington, H. (Allied-Signal Aerospace Co., Phoenix, AZ (United States). Garrett Auxilliary Power Division)

1993-01-01

61

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

62

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

63

Greenhouse Gas Impacts of Ethanol from Iowa Corn  

Microsoft Academic Search

As the United States begins to move towards putting an economic value on reducing greenhouse gas (GHG) emissions, the need for improved accounting standards becomes acute. Lifecycle analysis (LCA), which involves the systematic collection and interpretation of material flow in all relevant processes of a product, has become the accepted procedure to use to determine greenhouse gas emissions of products

Hongli Feng; Ofir D. Rubin; Bruce A. Babcock

2008-01-01

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

Volcanic gas impacts on vegetation at Turrialba Volcano, Costa Rica  

NASA Astrophysics Data System (ADS)

Turrialba volcano is an active composite stratovolcano that is located approximately 40 km east of San Jose, Costa Rica. Seismic activity and degassing have increased since 2005, and gas compositions reflect further increased activity since 2007 peaking in January 2010 with a phreatic eruption. Gas fumes dispersed by trade winds toward the west, northwest, and southwest flanks of Turrialba volcano have caused significant vegetation kill zones, in areas important to local agriculture, including dairy pastures and potato fields, wildlife and human populations. In addition to extensive vegetative degradation is the potential for soil and water contamination and soil erosion. Summit fumarole temperatures have been measured over 200 degrees C and gas emissions are dominated by SO2; gas and vapor plumes reach up to 2 km (fumaroles and gases are measured regularly by OVSICORI-UNA). A recent network of passive air sampling, monitoring of water temperatures of hydrothermal systems, and soil pH measurements coupled with measurement of the physiological status of surrounding plants using gas exchange and fluorescence measurements to: (1) identify physiological correlations between leaf-level gas exchange and chlorophyll fluorescence measurements of plants under long term stress induced by the volcanic gas emissions, and (2) use measurements in tandem with remotely sensed reflectance-derived fluorescence ratio indices to track natural photo inhibition caused by volcanic gas emissions, for use in monitoring plant stress and photosynthetic function. Results may prove helpful in developing potential land management strategies to maintain the biological health of the area.

Teasdale, R.; Jenkins, M.; Pushnik, J.; Houpis, J. L.; Brown, D. L.

2010-12-01

66

Understanding the Impacts of Incremental Gas Supply on the Flow Dynamics Across the North American Grid  

EIA Publications

The presentation "Understanding the Impacts of Incremental Gas Supply on the Flow Dynamics Across the North American Grid" was given at the Canadian Institute's BC LNG Forum on November 20, 2006. The presentation provides an overview of EIA's long-term natural gas projections under reference case and sensitivity cases from the Annual Energy Outlook 2006, with special emphasis on natural gas flows in the West Coast.

Information Center

2006-12-14

67

Impact of natural gas market on power generation development in Russia  

Microsoft Academic Search

The paper concerned with research of natural gas market and itpsilas impact on power generation development in Russia. We can state that the gas share at thermal power plants of Russia, despite a sharp gas price rise (from 50$\\/1000 m3 currently to 170 $\\/1000 m3 in 2020), can be decreased only 11-12% in favor of increase in the coal share,

N. I. Voropai; V. I. Rabchuk; S. M. Senderov; N. I. Pyatkova

2008-01-01

68

Onshore Impacts of Oil and Gas Development in Alaska. Volume I.  

National Technical Information Service (NTIS)

Overall, the potential secondary impacts, both economic and environmental, on Alaska resulting from outer continental shelf as well as on onshore oil and gas development will be substantial. These impacts will be felt on a local basis in varying degrees o...

1975-01-01

69

The impact of demographic change on energy use and greenhouse gas emissions in Germany  

Microsoft Academic Search

This paper estimates the impact of demographic change on energy use and greenhouse gas emissions in Germany. Since old people display different consumption patterns than young people, an increase in the proportion of old people affects overall consumption patterns. Micro data from a household survey are used to identify age-specific consumption patterns and to project the impact of demographic change

Tobias Kronenberg

2009-01-01

70

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

71

Impacts of urban form on future US passenger-vehicle greenhouse gas emissions  

Microsoft Academic Search

Urban form – for example, sprawl versus infill development – impacts people's daily travel patterns and annual vehicle-kilometers traveled (VKT). This paper explores how urban form impacts greenhouse gas (GHG) emissions from passenger-vehicles, the largest source of urban transportation GHG emissions. Our research uses a recently published urban scaling rule to develop six scenarios for high- and low-sprawl US urban

Steve Hankey; Julian D. Marshall

2010-01-01

72

An evaluation system for impact damage and erosion of ceramic gas turbine components  

NASA Astrophysics Data System (ADS)

A computational method has been developed in order to analyze the impact damage and erosion of ceramic gas turbine components in a gas flow mixed with solid particles. Blade-row flow analysis is supplemented by boundary layer calculations, particle trajectory analysis, and particle erosion analysis. The method's validity was verified by means of numerical simulations of spherical particle impact tests on ceramic plates. An empirical equation derived from elevated temperature erosion tests was implemented for blade-erosion analyses relevant to industrial gas turbines employing advanced fuels.

Hamada, Seiichi; Teramae, Tetsuo

1992-08-01

73

Integrated Analysis of Greenhouse Gas Mitigation Options and Related Impacts  

EPA Science Inventory

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

74

Water\\/acid gas interfacial tensions and their impact on acid gas geological storage  

Microsoft Academic Search

Acid gas geological disposal is a promising process to reduce CO2 atmospheric emissions and an environment-friendly and economic alternative to the transformation of H2S into sulphur by the Claus process. Acid gas confinement in geological formations is to a large extent controlled by the capillary properties of the water\\/acid–gas\\/caprock system, because a significant fraction of the injected gas rises buoyantly

Virenkumar Shah; Daniel Broseta; Gerard Mouronval; François Montel

2008-01-01

75

75 FR 67997 - Notice of Correction to Notice of Intent To Prepare an Environmental Impact Statement for the Gas...  

Federal Register 2010, 2011, 2012, 2013

...Environmental Impact Statement for the Gas Hills Uranium Project, Fremont and Natrona Counties...Environmental Impact Statement for the Gas Hills Uranium Project, Fremont and Natrona Counties...legal land description for the Gas Hills Uranium Project location is as follows:...

2010-11-04

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

Analysis of impact energy factors in ductile materials using single particle impact tests on gas gun  

Microsoft Academic Search

Wear is surface damage that involves progressive material loss due to relative motion between the contacting surfaces. Removal of material by action of impacting particles is known as erosion. Single particle impact tests were conducted using small particles (95–100?m) and impact velocity 90ms?1. A new technique has been developed to measure the impact crater using Laser Scanning Confocal Microscope (LSCM).

A. A. Cenna; K. C. Williams; M. G. Jones

2011-01-01

78

HYDROGEN PRODUCTION BY NATURAL GAS STEAM REFORMING ENVIRONMENTAL IMPACT ASSESSMENT  

Microsoft Academic Search

The concern with sustainable development has been taking to a constant improvement in the tools for environmental management. Life cycle assessment (LCA) is a systematic analytical method that helps identify and evaluate the environmental impacts of process, product or activity processes. In order to quantify the emissions, resource consumption, and energy use, material and energy balances are performed in a

J. Cintra da Silva

79

Impacts of Sixteen Different Biochars on Soil Greenhouse Gas Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

80

Rarefied gas correction for the bubble entrapment singularity in drop impacts  

NASA Astrophysics Data System (ADS)

We study the non-continuous correction in the dynamics of drop impact on a solid substrate. Close to impact, a thin film of gas is formed beneath the drop so that the local Knudsen number is of order one. We consider the first correction to the dynamics which consists of allowing slip of the gas along the substrate and the interface. We focus on the singular dynamics of entrapment that can be seen when surface tension and liquid viscosity can be neglected. There we show that different dynamical regimes are present that tend to lower the singularity strength. We finally suggest how these effects might be connected to the influence of the gas pressure in the impact dynamics observed in recent experiments.

Duchemin, Laurent; Josserand, Christophe

2012-11-01

81

The relative greenhouse gas impacts of realistic dietary choices  

Microsoft Academic Search

The greenhouse gas (GHG) emissions embodied in 61 different categories of food are used, with information on the diet of different groups of the population (omnivorous, vegetarian and vegan), to calculate the embodied GHG emissions in different dietary scenarios. We calculate that the embodied GHG content of the current UK food supply is 7.4kg CO2eperson−1day−1, or 2.7tCO2eperson−1y−1. This gives total

M. Berners-Lee; C. Hoolohan; H. Cammack; C. N. Hewitt

2012-01-01

82

Secondary benefits of greenhouse gas control: Health impacts in China  

Microsoft Academic Search

In addition to long-term benefits of greenhouse gas (GHG) reductions in the form of avoided health and ecosystem damage, there are important near-term benefits resulting from the reduction in health-damaging pollutants (HDP) that can accompany GHG reductions. This paper estimates such health benefits, using the power and household energy sectors of China as a case study for the method. Four

Xiaodong Wang; Kirk R. Smith

1999-01-01

83

Very-high-temperature gas reactor environmental impacts assessment  

Microsoft Academic Search

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°F steam-methanation reformer step in a hydrogen producing plant (via hydrogasification of coal liquids) was examined. It was found that: (a) from the viewpoint of product contamination

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

1977-01-01

84

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

85

Contact time during impact of a spherical particle against a plane gas-liquid interface: theory  

Microsoft Academic Search

Bubble-particle impact in flotation is usually approximated to the particle approaching against a plane gas-liquid interface. In this paper we theoretically re-investigate this interaction and deal with its non-linear problems.It is evident that the restoring force is a non-linear ‘mixed’ function of the transition angle and the maximum depth of the deformed gas-liquid interface. This ‘mixed’ expression makes analytical prediction

A. V. Nguyen; H. J. Schulze; H. Stechemesser; G. Zobel

1997-01-01

86

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

87

Gas Gun Impact Analysis on Adhesives in Sandwich Composite Panels  

Microsoft Academic Search

\\u000a As the application of composite sandwich panels is ever increasing, there is an increasing interest in the impact damage that\\u000a occurs on these sandwich panels. Since these composite sandwich panels are constructed in various manners, analysis on different\\u000a panel construction practices is of interest. Specifically, when a sandwich composite is cured, a film adhesive or just the\\u000a prepreg resin system

Matthew Mordasky; Weinong Chen

88

Solar Type Binary Systems with Impacting Gas Streams  

NASA Astrophysics Data System (ADS)

Our quest is the discovery of near-contact solar type eclipsing binaries which show evidence of stream impacts. The existence of stream impacts would provide evidence of dynamic mass transfer possibly leading to coalescence into contact. This would lend strong support to the theoretical scenarios of 1) Angular Momentum Loss (AML) via magnetic breaking and 2) Thermal Relaxation Oscillations (TRO) ,ie., oscillations between a near-contact and shallow contact modes. We hypothesize that many F to early K spectral type binaries formerly classified as ''thermally decoupled'' contact binaries and other binaries with large differences in eclipse depths formerly classified as contact binaries in the 0.33 to 0.5d period range will reveal such stream impacts when they are subjected to precision UBVRI multi-band photometry, since these fall in the pre-contact period range for F to K dwarf binaries. Modern light curve synthesis techniques will be used to simultaneously model the multi-band light curves. Impact spots will be adjusted numerically along with the stellar atmosphere parameters. Spectroscopic work will follow to verify stream activity in emission lines and to obtain radial velocity curves for calculating orbital parameters and fundamental physical characteristics. Our larger goal is to understand close binary evolution in general, in detached, semi-detached and contact modes. This study could supply an important piece to the puzzle. We now have found four stream system candidates: CN And, BE Cep, ZZ Eri and V343 Cen giving us an encouraging 40 % rate of recovery.

Samec, Ronald G.; Hube, Doug; Faulkner, Danny R.; van Hamme, W.

2002-02-01

89

Solar-Type Eclipsing Binary Systems with Impacting Gas Streams  

NASA Astrophysics Data System (ADS)

Our quest is the recovery of near contact solar type eclipsing binaries with evidence for stream impacts. Their existence will provide strong support of dynamic mass transfer leading to coalescence into a state of contact. This will lend strong support to the theoretical scenarios of 1) angular momentum loss(AML)via magnetic breaking scenario and 2)Thermal Relaxation Oscillations (TRO)or oscillations between a near­contact and shallow contact modes. We hypothesize that many F to early K spectral type binaries formerly classified as ''thermally decoupled'' contact binaries and other binaries with large differences in eclipse depths formerly classified as contact binaries in the 0.33 to 0.5d period range will reveal evidence for stream impacts when they are subjected to precision UBVRI multi­band photometry, since these fall in the pre­contact period range for F to K dwarf binaries. Modern light curve synthesis techniques will be used to simultaneously model the multi­band light curves. Impact spots will be adjusted numerically along with the stellar atmosphere parameters. Spectroscopic work will follow to verify stream activity and to obtain fundamental physical characteristics. Our larger goal is to understand close binary evolution in general. This study could supply an important piece to the puzzle. We now have found four candidates, CN And, BE Cep, ZZ Eri and V343 Cen giving us an encouraging 40 percent recovery thus far.

Samec, Ronald G.; Hube, Doug; Faulkner, Danny R.; van Hamme, W.

2002-08-01

90

Compressed Gas Gun for Controlled Planar Impacts Over a Wide Velocity Range  

Microsoft Academic Search

A description is given of the mechanical characteristics and performance of a compressed gas gun capable of accelerating precisely aligned flat-faced projectiles over a wide velocity range. Predetermined reproducible velocities may be achieved between 150 and 5700 ft?sec with an angular misalignment between the impacting surfaces as small as 1.3×10?4 rad. The impact occurs in a vacuum with pressures as

S. Thunborg; G. E. Ingram; R. A. Graham

1964-01-01

91

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

92

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

93

Impact of compressed natural gas fueled buses on street pavements  

SciTech Connect

Capital Metro, the Ausin, Texas transit authority, is currently evaluating a number of CNG fueled buses. As part of the U.S. DOT Region Six University Transportation Centers Program (UTCP), a study was instigated into the scale of incremental pavement consumption associated with the operation of these buses. The study suggests that replacing current vehicles with CNG powered models utilizing aluminum storage tanks would raise average network equivalent single rehabilitation costs across the network of over four percent. Finally, it recommends that full cost study be undertaken with evaluation of the adoption of alternative bus fuels - which includes pavement and environmental impacts.

Yang, D.; Harrison, R.

1995-07-01

94

Velocity Scaling of Neutral Gas Generation from Hypervelocity Dust Impact  

NASA Astrophysics Data System (ADS)

We present direct laboratory measurement of vapor produced by simulated micrometeoroid bombardment. New in-situ observations from the Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft, and the anticipation of results from the Lunar Atmosphere and Dust Environment Explorer (LADEE), have highlighted the uncertainty surrounding the role of micrometeoroid impacts in sustaining planetary exospheres. In a recent series of experiments, the quantity of neutral molecules generated by impacts of simulated micrometeorids of 0.1-1 micron radius was measured using a fast ion gauge, over a speed range of 1-10 km/s. The quantity of neutrals released per unit projectile mass, N/m, is consistent with a power law N/m = v^b in the projectile speed v, with b ~ 2.4. At the highest speeds tested, the number of neutrals liberated is equivalent to a few percent of the atoms in the projectile; near-complete vaporization is projected at speeds exceeding 20 km/s.

Collette, Andrew; Munsat, T.; Sternovsky, Z.; Horanyi, M.

2013-10-01

95

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

2012-05-15

96

QUANTIFYING LEASE STIPULATION IMPACTS ON FEDERAL OIL AND NATURAL GAS RESOURCE ACCESSIBILITY  

Microsoft Academic Search

An analysis was completed that made innovative use of the Energy Policy and Conservation Act Inventory data base and model examined how changes in lease stipulation brought about by research could increase access to federal oil and natural gas resources in ten Rocky Mountain Basins. The analysis ranked classes of lease stipulations according to their potential impact on these resources

John R. Duda; David Alleman; H. William Hochheiser; Jeffrey F. Eppink; Ramon Alvarado

97

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...

98

Impact of natural gas pipeline on mineral and energy development in Alaska  

Microsoft Academic Search

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 to tidewater where it would be liquified for transport to West Coast ports. The geology and the potential for

R. G. Bottge

1975-01-01

99

Impact of natural gas pipeline on mineral and energy development in Alaska. Open file report  

Microsoft Academic Search

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 to tidewater where it would be liquified for transport to West Coast ports. This report summarizes the geology and

Bottge

1975-01-01

100

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

101

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

Microsoft Academic Search

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

J. Lee; J. Kim; H. Chang

2001-01-01

102

Crater formation by nanoparticle impact: contributions of gas, melt and plastic flow  

NASA Astrophysics Data System (ADS)

The processes underlying crater formation by energetic nanoparticle impact are investigated using molecular dynamics simulations. Both metallic and van-der-Waals-bonded targets are studied. We find a transition from crater formation by melt flow at small impact energies to an evaporation (gas flow) mechanism at higher energies. The transition occurs gradually at impact energies per atom of a few tens of the cohesive energy of the target. van-der-Waals-bonded solids do not exhibit the melt flow cratering regime, in agreement with the narrow liquid zone in their phase diagram. We find that the size of the target region heated above the critical temperature roughly corresponds to the crater volume. The transition shows up most clearly in the increase of the volume of ejected material relative to the crater volume. Finally, we demonstrate the punching of dislocations below the crater for high-velocity impact into ductile targets, leading to a contribution of plastic flow to the crater volume.

Anders, Christian; Ziegenhain, Gerolf; Ruestes, Carlos J.; Bringa, Eduardo M.; Urbassek, Herbert M.

2012-08-01

103

Putting downward pressure on natural gas prices: The impact of renewable energy and energy efficiency  

SciTech Connect

Increased deployment of renewable energy (RE) and energy efficiency (EE) is expected to reduce natural gas demand and in turn place downward pressure on gas prices. A number of recent modeling studies include an evaluation of this effect. Based on data compiled from those studies summarized in this paper, each 1% reduction in national natural gas demand appears likely to lead to a long-term average wellhead gas price reduction of 0.75% to 2.5%, with some studies predicting even more sizable reductions. Reductions in wellhead prices will reduce wholesale and retail electricity rates, and will also reduce residential, commercial, and industrial gas bills. We further find that many of these studies appear to represent the potential impact of RE and EE on natural gas prices within the bounds of current knowledge, but that current knowledge of how to estimate this effect is extremely limited. While more research is therefore needed, existing studies suggest that it is not unreasonable to expect that any increase in consumer electricity costs attributable to RE and/or EE deployment may be substantially offset by the corresponding reduction in delivered natural gas prices. This effect represents a wealth transfer (from natural gas producers to consumers) rather than a net gain in social welfare, and is therefore not a standard motivation for policy intervention on economic grounds. Reducing gas prices and thereby redistributing wealth may still be of importance in policy circles, however, and may be viewed in those circles as a positive ancillary effect of RE and EE deployment.

Wiser, Ryan; Bolinger, Mark; St. Clair, Matthew

2004-05-20

104

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

NASA Astrophysics Data System (ADS)

Since the United States began a programme 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, Michael; Wu, May; Huo, Hong

2007-04-01

105

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

106

Influence of excitation frequency on slosh-induced impact pressures of liquefied natural gas tanks  

Microsoft Academic Search

Liquid sloshing phenomena in No. 2 tank of 140 km3 liquefied natural gas (LNG) carriers have been studied numerically and experimentally. The scale of the model tank was selected\\u000a as 1\\/55.9. Roll and pitch motions were tested. For measuring impact pressures, seventeen pressure sensors were installed on\\u000a the tank model. A large number of excitation frequencies and filling heights were

Zhong-hua Cai; De-yu Wang; Zhe Li

2011-01-01

107

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

Microsoft Academic Search

The ballistic impact resistance of hybrid composite sandwich structures was evaluated with the ultimate goal of developing\\u000a new materials or structures for potential gas turbine engine, fan containment applications. The sandwich structures investigated\\u000a consisted of GLARE-5 (Aviation Equipment, Inc., Costa Mesa, CA) laminates as face sheets with lightweight cellular metallic\\u000a materials such as honeycomb, foam, and lattice block as a

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

2003-01-01

108

Modeling Impacts of Management on Carbon Sequestration and Trace Gas Emissions in Forested Wetland Ecosystems  

Microsoft Academic Search

A process-based model, Wetland-DNDC, was modified to enhance its capacity to predict the impacts of management practices on carbon sequestration in and trace gas emissions from forested wetland ecosystems. The modifications included parameterization of management practices (e.g., forest harvest, chopping, burning, water management, fertilization, and tree planting), inclusion of detailed anaerobic biogeochemical processes for wetland soils, and utilization of hydrological

Changsheng Li; Jianbo Cui; Ge Sun; Carl Trettin

2004-01-01

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

Impact of exploratory offshore drilling on benthic communities in the Minerva gas field, Port Campbell, Australia  

Microsoft Academic Search

Changes to benthic infauna caused by exploratory gas drilling operations in the Minerva field were examined experimentally using a BACI (before, after, control, impact) design. Analysis of 72×0.1 m2 Smith–McIntyre grab samples obtained from one pre-drilling and three post-drilling periods yielded a diverse fauna consisting of 196 invertebrate species and 5035 individuals. Changes to benthic community structure were assessed using

D. R. Currie; Leanne R. Isaacs

2005-01-01

111

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

Microsoft Academic Search

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

Robert Bailis; Majid Ezzati; Daniel M. Kammen

2005-01-01

112

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

113

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

2013-08-30

114

Study of density effect of large gas cluster impact by molecular dynamics simulations  

NASA Astrophysics Data System (ADS)

Large gas cluster impacts cause unique surface modification effects because a large number of target atoms are moved simultaneously due to high-density particle collisions between cluster and surface atoms. Molecular dynamics (MD) simulations of large gas cluster impacts on solid targets were carried out in order to investigate the effect of high-density irradiation with a cluster ion beam from the viewpoint of crater formation and sputtering. An Ar cluster with the size of 2000 was accelerated with 20 keV (10 eV for each constituent atom) and irradiated on a Si(1 0 0) solid target consisting of 2 000 000 atoms. The radius of the Ar cluster was scaled by ranging from 2.3 nm (corresponding to the solid state of Ar) to 9.2 nm (64× lower density than solid state). When the Ar cluster was as dense as solid state, the incident cluster penetrated the target surface and generated crater-like damage. On the other hand, as the cluster radius increased and the irradiation particle density decreased, the depth of crater caused by cluster impact was reduced. MD results also revealed that crater depth was mainly dominated by the horizontal scaling rather than vertical scaling. A high sputtering yield of more than several tens of Si atoms per impact was observed with clusters of 4-20× lower volume density than solid state.

Aoki, Takaaki; Seki, Toshio; Matsuo, Jiro

2009-09-01

115

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

116

Nonwater Quality Impacts of Closed-Cycle Cooling Systems and the Interaction of Stack Gas and Cooling Tower Plumes.  

National Technical Information Service (NTIS)

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 type...

G. A. Englesson M. C. Hu

1979-01-01

117

Effectiveness and Potential Environmental Impacts of Biocides and Corrosion Inhibitors in the Natural Gas Industry. Topical Report, December 1995.  

National Technical Information Service (NTIS)

The objective of this study was to assess the effectiveness and potential environmental impacts of chemical products used in natural gas industry (NGI) operations. The assessment was focused primarily on biocides and corrosion inhibitors used in storage a...

E. A. Morris D. H. Pope J. P. Fillo D. M. Brandon M. E. Fetsko J. W. Fulton

1995-01-01

118

Energy/Economic Model Analysis. Macroeconomic Impacts of Research and Development in Gas Supply and End Use Technologies.  

National Technical Information Service (NTIS)

The Gas Research Institute (GRI) needs to consider the economic impact of the various technologies whose research and development is supported by GRI funding. Previous analysis indicated that three energy-economic models would be useful for such a technol...

R. J. Goettle E. A. Hudson

1980-01-01

119

Hurricane Andrew's Impact on Natural Gas and Oil Facilities on the Outer Continental Shelf (Interim Report as of November 1993).  

National Technical Information Service (NTIS)

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 t...

G. R. Daniels

1994-01-01

120

Embryo Impacts and Gas Giant Mergers. I. Dichotomy of Jupiter and Saturn's Core Mass  

NASA Astrophysics Data System (ADS)

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

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

2010-09-01

121

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

NASA Astrophysics Data System (ADS)

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 produced is collected and analyzed, and the production of fullerenes is confirmed.

Mieno, Tetsu

2008-06-01

122

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

123

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

National Technical Information Service (NTIS)

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 vehi...

M. Q. Wang

1997-01-01

124

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

Microsoft Academic Search

The objective of this effort was to perform an assessment of the potential impacts of air toxics regulations on the natural gas industry. Natural gas industry operations were reviewed to identify potential sources of air toxics emissions and representative compounds that may be emitted, as one basis for the evaluation. Legislation that regulate air toxics exist at the federal and

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

1992-01-01

125

The impact of the Arab spring on the oil and gas industry in North Africa – a preliminary assessment  

Microsoft Academic Search

In 2011, popular movements toppled the leaders of Tunisia, Egypt, and Libya. These uprisings are likely to have a short- and long-term impact on these societies with global ramifications. This study focuses on Egypt and Libya and highlights how the oil and gas industry in these two North African countries has been impacted by political upheavals. Specifically, I examine the

Gawdat Bahgat

2012-01-01

126

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

127

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

SciTech Connect

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

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

1996-03-01

128

[Impact of hypoxic gas mixtures on embryogenesis of the Japanese quail].  

PubMed

Avian embryogenesis is of great interest to investigators, as the germ developing outside mother's body, is capable to react briskly to any alteration in the outer world. The paper present experimental evidence of the impact of oxygen with physical and chemical properties modified by short-cycle no-heating adsorption (SNA) in a hypoxic gas mixture (10% O2) on the early embryogenesis of the Japanese quail. Low concentrations of oxygen are known to be a dramatically disturbing factor for embryo's morphology. It was demonstrated experimentally that four days before incubation bird are highly sensitive to oxygen deficiency which is responsible for developmental abnormalities. The use of SNA oxygen reduced the frequency of pathologies in the Japanese quail germs as compared with their controls incubated in gas environment containing medical oxygen generated by low-temperature rectification. PMID:18672516

Soldatov, P E; Gur'eva, T S; Dadasheva, O A; Smirnov, I A; Smolenskaia, T S; Mednikova, E I; Lysenko, L A

129

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

130

Influence of Impact Angle and Gas Temperature on Mechanical Properties of Titanium Cold Spray Deposits  

NASA Astrophysics Data System (ADS)

Titanium coatings have a high potential for various applications and can be produced in high quality by cold spraying. In this contribution, the two major challenges are addressed: (i) optimizing mechanical properties by systematic variation of process parameters, and (ii) evaluating the influence of the spray angle with respect to complex geometries. High deposition efficiencies of more than 95% can be obtained and the coatings show very low porosities as well as high tensile strength of over 450 MPa by using nitrogen as process gas. The influence of process conditions on the mechanical properties is discussed on the basis of single impact morphologies, coating microstructures, tubular coating tensile, as well as shear tests.

Binder, K.; Gottschalk, J.; Kollenda, M.; Gärtner, F.; Klassen, T.

2011-01-01

131

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

132

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

133

Identification of ion fragments produced from thymine and deuterated thymine by low energy ion impact in films and electron impact in the gas phase  

Microsoft Academic Search

The chemical composition of charged fragments desorbing from thymine-methyl-d3-6-d (Td) films during 10–200eV Ar+ ion irradiation is studied by mass spectrometry of positive and negative ions. The resulting mass spectra are compared to those obtained from similar films of thymine (T), and from 70eV electron impact on both T and Td in the gas phase. Ion impact on T and

Marjorie Imhoff; Zongwu Deng; Michael A. Huels

2005-01-01

134

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

135

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

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

136

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

SciTech Connect

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

Kirschner, C.E.; Grantz, A. (Geological Survey, Menlo Park, CA (USA))

1990-05-01

137

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

NASA Astrophysics Data System (ADS)

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 operates nine electron valves. To improve the gun reliability, the control system has been designed to carry out an automatic diagnostic procedure after each shot. To improve the gun performance and the safety, an active piston-damping procedure has been developed. In this configuration a high shot frequency has been reached (10 shots/h) . Projectiles with mass between 100- 300 mg have been launched up to 3- 4 km/s depending on the mass. This work can also be seen as a feasibility study for a new class of high-performance, high-frequency and low-cost two-stage light-gas guns, useful for the Italian Hypervelocity Laboratory, proposed to be built at the Italian Center for Aerospatial Research (CIRA).

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

2003-08-01

138

Modeling particle growth and morphology of impact polypropylene produced in the gas phase  

NASA Astrophysics Data System (ADS)

A gas phase reactor system using on-line FTIR for controlled composition olefin polymerization experiments with gaseous or liquid monomers has been designed and constructed in this work. Using this equipment, a comprehensive study of the kinetics, particle growth and morphological development of impact polypropylene produced in-situ with a TiClsb4/MgClsb2 catalyst has been conducted. The catalyst was found exhibiting a decay type behavior for ethylene and propylene homopolymerization but an activation effect was observed when both monomers were present together. Hydrogen was also seen to boost the rate of propylene polymerization but not ethylene, and increased the rate of catalyst deactivation during propylene polymerization. Microscopy analysis of the particles over a range of copolymer content (up to 70 wt. %), copolymer composition, reaction temperature and hydrogen levels reveal how the copolymer phase segregates from the homopolymer and grows within the homopolymer matrix. A model for particle growth is proposed. A computer model for the study of the effects of changing morphology for polyolefins produced in multistage processes has been developed and used to investigate the role of monomer diffusion limitations during polymerization using the experimental data found in this work. To study the effects of residence time distribution in multistage continuous processes for impact polypropylene, population balance models have been developed for multistage processes consisting of gas and liquid phase reactors. The effects of catalyst size distribution and monomer diffusion limitations can be incorporated into the models. It is shown that commercial impact polypropylene consists of a broad distribution of polymer properties as a consequence of reactor residence time distribution issues. Implications for product homogeneity, particle sticking and process productivity are discussed.

Debling, Jon A.

139

Production of Various Carbon Nanoclusters by Impact Reaction Using Light-Gas Gun as Simulation of Asteroid Collisions in Space  

NASA Astrophysics Data System (ADS)

An impact production of carbon nanoclusters is carried out in nitrogen gas using a two-stage light-gas gun. A small polycarbonate ball (or a stainless steel ball) is injected at about 6.5 km/s into a pressurized target chamber to collide with an aluminum target (or a hexane + aluminum target) in 1 atm of nitrogen gas. We can confirm the production of many types of carbon nanoclusters such as aluminum-encapsulated carbon nanoparticles, carbon nanotubes, and balloonlike nanocarbons. Therefore, it is expected that many types of carbon nanoclusters are produced by impact reactions of asteroids in space, when such reactions take place in a carbon-rich atmosphere. Particularly on Titan satellite, a large number of carbon clusters produced by impacts of asteroids are expected to be stored.

Mieno, Tetsu; Hasegawa, Sunao; Mitsuishi, Kazutaka

2011-12-01

140

Photolytic clean-up of biological samples for gas chromatographic analysis of chlorinated paraffins  

Microsoft Academic Search

A method based on gas chromatography electron capture detection (GC-ECD) for the analysis of chlorinated paraffins (CPs) in biological samples has been investigated. The method includes photolytic destruction of halogenated aromatic compounds, such as PCBs, to eliminate some of the interferences in the analysis of CPs in environmental samples. Gel permeation chromatography was used to isolate CPs from the interfering

Ulrika Fridén; Bo Jansson; Harun Parlar

2004-01-01

141

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

142

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

143

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

NASA Astrophysics Data System (ADS)

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

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

1980-06-01

144

Examination of Enceladus plume variability and the impact on magnetospheric neutral gas distribution  

NASA Astrophysics Data System (ADS)

The neutral particle dominance over charged particles in Saturn's magnetosphere was evident prior to Cassini arrival at Saturn in 2004. However, the observation of active plumes emanating from the southern pole of the small icy moon, Enceladus provided key information for understanding particle sources and dynamics in the magnetospheric region. Estimates show this 252 km radius moon is likely the dominant source of particles in the magnetosphere producing 1027 to 1028 neutral water molecules per second. Cassini has flown through the plumes on several occasions which appear to indicate variability in this source rate. For this research, we use Cassini CAPS, MIMI and INMS observations during these encounters to constrain our 3-D multi-species neutral particle model to estimate the plume source rate for these encounters and also examine the impact of potential variability on magnetospheric neutral gas density.

Smith, H. T.; Johnson, R. E.; Perry, M.; Mitchell, D. G.; McNutt, R.; Young, D. T.

2009-05-01

145

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

PubMed

Life cycle assessment is increasingly used to assess the environmental performance of fossil energy systems. Two of the dominant emissions of offshore oil and gas production to the marine environment are the discharge of produced water and drilling waste. Although environmental impacts of produced water are predominantly due to chemical stressors, a major concern regarding drilling waste discharge is the potential physical impact due to particles. At present, impact indicators for particulate emissions are not yet available in life cycle assessment. Here, we develop characterization factors for 2 distinct impacts of particulate emissions: an increased turbidity zone in the water column and physical burial of benthic communities. The characterization factor for turbidity is developed analogous to characterization factors for toxic impacts, and ranges from 1.4 PAF (potentially affected fraction) · m(3) /d/kg(p) (kilogram particulate) to 7.0 x 10³ [corrected] for drilling mud particles discharged from the rig. The characterization factor for burial describes the volume of sediment that is impacted by particle deposition on the seafloor and equals 2.0 × 10(-1) PAF · m(3) /d/kg(p) for cutting particles. This characterization factor is quantified on the basis of initial deposition layer characteristics, such as height and surface area, the initial benthic response, and the recovery rate. We assessed the relevance of including particulate emissions in an impact assessment of offshore oil and gas production. Accordingly, the total impact on the water column and on the sediment was quantified based on emission data of produced water and drilling waste for all oil and gas fields on the Norwegian continental shelf in 2008. Our results show that cutting particles contribute substantially to the total impact of offshore oil and gas production on marine sediments, with a relative contribution of 55% and 31% on the regional and global scale, respectively. In contrast, the contribution of particulate emissions to the total impact on the marine water column is of minor importance. We conclude that particles are an important stressor in marine ecosystems, particularly for marine sediment, and particulate emissions should therefore be included in a (life cycle) impact assessment of offshore oil and gas production. PMID:21735543

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

2011-08-26

146

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

NASA Astrophysics Data System (ADS)

Groundwater contamination due to accidental releases of mono- and polycyclic aromatic compounds (MAHs and PAHs) from decommissioned manufactured-gas plants is an ongoing and litigious problem. The MAHs and PAHs are derived from coal tar, which was a by-product of the gas-manufacturing process. While originally designed to contain coal tar, the manufactured-gas plant structures that remain today have often degraded over time and are not completely leak-proof. Over a period of many years, subsurface water has seeped into and out of the structures, resulting in groundwater contamination. This was particularly true once the tops of the structures were removed. In this study, process-based simulations were conducted to estimate the groundwater-quality impacts of accidental releases of dissolved naphthalene (C10H8) from the sites of three former manufactured-gas plants. The results from one-dimensional, transient, unsaturated, near-surface fluid-flow and solute-transport simulations served as input to three-dimensional saturated subsurface fluid-flow and solute-transport simulations. The simulation results and sensitivity analysis reported here indicate that accidental releases of naphthalene had significant, negative impacts on groundwater quality at each of the three sites. Résumé. La contamination d'une nappe par relargage accidentel de composés aromatiques mono- et polycycliques (HAM et HAP) à partir d'usines à gaz abandonnées est un problème persistant et litigieux. Les HAM et les HAP proviennent du goudron de charbon qui était un sous-produit du procédé de fabrication du gaz. Alors qu'elles étaient prévues pour contenir du goudron, les structures des usines à gaz qui restent actuellement se sont souvent dégradées avec le temps et ne sont plus étanches. En plusieurs années, les eaux de surface se sont infiltrées dans ces structures et en sont ressorties, en provoquant une contamination des eaux souterraines. Ceci s'est produit en particulier lorsque les toits des bâtiments ont été enlevés. Dans cette étude, des simulations basées sur les processus ont été réalisées pour évaluer les impacts de relargages accidentels de naphtalène (C10H8) sur la qualité de l'eau souterraine à partir de sites de trois anciennes usines à gaz. Les résultats de simulations d'écoulement de fluide et de transport de soluté près de la surface, en une dimension, en régime transitoire et en milieu non saturé ont été utilisés comme entrées de simulations d'écoulement de fluide et de transport de soluté d'eau souterraine à trois dimensions et en milieu saturé. Les résultats des simulations et l'analyse de sensibilité fournis ici montrent que les relargages accidentels de naphtalène ont des impacts négatifs significatifs sur la qualité de l'eau en chacun des trois sites. Resumen. La contaminación de las aguas subterráneas debido a vertidos accidentales de compuestos aromáticos mono- y policíclicos (MAHs y PAHs) en plantas de producción de gas abandonadas es un problema continuo y actual. Los MAHs y PAHs se derivan del alquitrán de hulla, que a su vez es un subproducto del proceso de manufactura del gas. Aunque las plantas de gas fueron diseñadas para contener alquitrán, las estructuras existentes hoy día se han ido degradando con el tiempo y no son estancas. Durante un período de muchos años, las aguas subsuperficiales han ido percolando a través de las estructuras, provocando la contaminación de las aguas subterráneas. Esto se comprobó al retirar las cubiertas de las estructuras. En este estudio, se han hecho simulaciones basadas en los procesos químicos para estimar la afección causada a la calidad de las aguas subterráneas por los vertidos accidentales de naftaleno disuelto (C10H8) en tres plantas de gas antiguas. Los resultados de simulaciones unidimensionales, en transitorio, para el flujo no saturado cercano a la superficie y el transporte de solutos, han sido utilizados para alimentar un modelo tridimensional de flujo y transporte en medio saturado. Los resultados y el anális

Abrams, Robert; Loague, Keith

2000-10-01

147

Impact of Halogens on Gas-Phase NMOCs in the Arctic Troposphere  

NASA Astrophysics Data System (ADS)

The Trace Organic Gas Analyzer (TOGA) was used to measure 25 non-methane organic compounds (NMOCs) near Barrow, Alaska during spring 2009 as part of the OASIS-Barrow study. Samples were taken at a frequency of up to once every five minutes, rotating from several sampling inlets on a 6-m tower for the duration of the study, as well as from a tethered balloon during one week in April. These data, which include observations of oxygenated NMOCs, halogenated NMOCs and non-methane hydrocarbons, were accompanied by whole air canister measurements of these and other NMOCs. Measurements of a number of chemically important gas-phase species as well as meteorological parameters were also obtained, resulting in a comprehensive characterization of the vertical structure of the lower atmosphere. Using observations from the tower, fluxes for many of the NMOCs measured by TOGA were calculated. A number of partial and near-complete ozone depletion events (ODEs) occurred during the 6 week study, providing an opportunity to investigate the chemistry of NMOCs during ODEs. The impact of halogen chemistry on observed NMOCs and fluxes during the ODEs contrasted with the boundary-layer chemistry of the non-ODE periods will be presented.

Hornbrook, R. S.; Apel, E. C.; Hills, A. J.; Riemer, D. D.; Fried, A.; Weibring, P.; Walega, J.; Helmig, D.; Staebler, R. M.; Oasis Science Team

2011-12-01

148

Impact of Salinity on the Air-Water Partition Coefficient of Gas Tracers  

SciTech Connect

The use of a gas partitioning interwell tracer test (PITT) has been proposed as a standard approach to the measurement of field-scale vadose zone water saturation fractions. The accuracy of the saturation measurement is largely dependent on the determination of the air-water partitioning coefficient, K, of the tracers; however, in practice, K is also strongly influenced by the physical and chemical properties of the water. In this study, column tests were conducted to investigate the impact of salinity on tracer partitioning coefficients for two promising gas phase candidate tracers, dibromomethane and dimethylether. Sodium thiosulfate was used as a salinity surrogate. The dynamic K values of the two partitioning tracers were measured for sodium thiosulfate concentrations between 0% and 36% by weight. Methane was used as the non-partitioning tracer for all experiments. K values were found to decrease significantly with increasing sodium thiosulfate concentration. Similar correlations between K values and sodium thiosulfate concentration were found for both of the partitioning tracers tested.

Zhong, Lirong; Pope, Gary A.; Evans, John C.; Cameron, Richard J.

2005-09-01

149

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

NASA Astrophysics Data System (ADS)

In the Space Telecope'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.

1983-06-01

150

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

PubMed

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

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

2011-08-15

151

GAS CHROMATOGRAPHY-ELECTRON IONIZATION MASS SPECTROMETRY AND LIQUID CHROMATOGRAPHY-ELECTROSPRAY TANDEM MASS SPECTROMETRY FOR DETERMINATION OF IMPURITIES IN THE ANTI-CANCER DRUG ISOPHOSPHORAMIDE MUSTARD  

Technology Transfer Automated Retrieval System (TEKTRAN)

Isophosphoramide mustard (IPM) is known to have substantial anti-cancer activities in various animal models. Liquid chromatography-electrospray mass spectrometry (LC-ES-MS) methods have been developed and applied to the analysis of synthesized preparations of IPM. Possible impurities can be formed...

152

Determination of pyrethroid metabolites in human urine using liquid phase microextraction coupled in-syringe derivatization followed by gas chromatography\\/electron capture detection  

Microsoft Academic Search

Metabolites of synthetic pyrethroids such as cis-3-(2,2-dibromovinyl)-2,2-di-methylcyclo-propane-1-carboxylic acid, cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid), 3-phenoxybenzoic acid (3-PBA), and 4-fluoro-3-PBA are\\u000a biomarkers for exposure to phenothrin, tetramethrin, cyfluthrin, cypermethrin, deltamethrin, and permethrin. In this study,\\u000a the pyrethroid metabolites in workers’ urine samples were monitored for the first time with a novel sample pretreatment process\\u000a combining hollow fiber liquid phase microextraction (HF-LPME) and in-syringe

Chiu-Hwa Lin; Cheing-Tong Yan; Ponnusamy Vinoth Kumar; Hong-Ping Li; Jen-Fon Jen

153

Determination of organochlorine pesticides in propolis by gas chromatography–electron capture detection using double column series solid-phase extraction  

Microsoft Academic Search

A rapid and reliable method was developed and applied for the simultaneous determination of 17 organochlorine pesticides (OCPs)\\u000a in propolis. After extraction with hexane and acetone (1:1, v\\/v), four sorbents (florisil, silica, graphitized carbon, and\\u000a tandem graphitized carbon plus florisil) were assayed for the clean-up step. The elution solvents hexane and ethyl acetate\\u000a (1:1, v\\/v), hexane and dichloromethane (3:7, v\\/v),

Fang Chen; Lanzhen Chen; Qiang Wang; Jinhui Zhou; Xiaofeng Xue; Jing Zhao

2009-01-01

154

Gas chromatography electron ionization mass spectrometric analysis of trimethylsilyl derivatives of bis(2-hydroxyethylthio)alkanes and bis(2-hydroxyethylsulfonyl) alkanes.  

PubMed

This communication describes GC-MS analysis of bis(trimethylsilyl) (bis-TMS) derivatives of bis(2-hydroxyethylthio)alkanes (BHETAs) and bis(2-hydroxyethylsulfonyl) alkanes (BHESAs) which are important markers of sulfur mustard class of chemical warfare agents. The study was undertaken with a view to develop spectral database of these compounds for verification analysis of Chemical Weapons Convention (CWC). Based on the obtained mass spectra of bis-TMS derivatives of BHETAs and BHESAs, the fragmentation routes are proposed, which explain most of the characteristic ions. PMID:17057283

Kanaujia, Pankaj K; Tak, Vijay; Pardasani, Deepak; Gupta, A K; Jain, Rajiv; Dubey, D K

2006-01-01

155

Single particle impact tests using gas gun and analysis of high strain-rate impact events in ductile materials  

Microsoft Academic Search

Removal of material by the action of impinging particles is known as erosion. Based on the understanding of the material removal mechanisms in ductile materials, in normal impact, material removal occurs predominantly by deformation whereas in oblique impacts, material is removed through a combination of cutting and deformation. Although material can be removed in cutting by a single impact, material

A. A. Cenna; N. W. Page; E. Kisi; M. G. Jones

2011-01-01

156

Impacts of High-Pressure Diecasting Process Parameters on Greenhouse Gas Emissions  

NASA Astrophysics Data System (ADS)

The impacts of some high-pressure diecasting (HPDC) process parameters on greenhouse gas (GHG) emissions are quantified using life cycle analysis (LCA) for both aluminum and magnesium alloys. The study was conducted according to ISO 14040 standards and was based on an automotive component made on cold-chamber HPDC machines operating in typical mass production environments. The aluminum alloy foundry was located in Australia; the magnesium alloy foundry was located in the United States. In both cases, emissions were found to reduce with an increasing HPDC process yield. However, yield variations had only a modest impact on GHG emissions in the aluminum alloy HPDC, due to the excellent in-plant recycling of the alloy and the relatively low emissions from primary aluminum production compared with primary magnesium production. In contrast, for the magnesium alloy, significant reductions in emissions were recorded as the yield increased. This outcome was attributed to the considerable savings achieved in raw material quantities sourced from high-emitting primary production and the use of lower amounts of SF6, a GHG with a very high global warming potential (GWP). These results were found to hold irrespective of changes to the ratio between the primary and secondary alloys in the raw material mix, although the magnitude of the impact was reduced considerably with reductions in the primary alloy component. In the case of the magnesium alloy HPDC, decreases in quality assurance (QA) rejects and cycle times were also found to contribute toward reduced emissions, although their influences were an order of magnitude lower than that of the yield improvements.

Gunasegaram, D. R.; Tharumarajah, A.

2009-08-01

157

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

Microsoft Academic Search

As part of a larger study of liquefied natural gas impacts on device performance and pollutant emissions for existing equipment in California, this report describes a cmoputer modeling study of a partially premixed flame issueing from a single cooktop burner port. The model consisted of a reactive computational fluid dynamics three-dimensional spatial grid and a 71-species chemical mechanism with propane

S. R. Tonse; B. C. Singer

2011-01-01

158

Impact of regulations--after federal leasing--on outer continental shelf oil and gas development. Report to the congress  

SciTech Connect

This report analyzes the impact various regulatory requirements stemming from the Outer Continental Shelf Lands Act Amendments of 1978 and other legislation are having--after leases are awarded--on industry efforts to explore and develop OCS oil and gas resources.

Not Available

1981-02-27

159

Effectiveness and potential environmental impacts of biocides and corrosion inhibitors in the natural gas industry. Topical report, December 1995  

Microsoft Academic Search

The objective of this study was to assess the effectiveness and potential environmental impacts of chemical products used in natural gas industry (NGI) operations. The assessment was focused primarily on biocides and corrosion inhibitors used in storage and transmission applications of the NGI.

E. A. Morris; D. H. Pope; J. P. Fillo; D. M. Brandon; M. E. Fetsko

1995-01-01

160

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...

161

The impacts of nitrous oxide gas on sleep quality during alcohol withdrawal  

PubMed Central

Background Poor quality of sleep among alcoholics and persons undergoing alcohol withdrawal has been described as a possible cause of alcohol relapse. It has been suggested earlier that nitrous oxide gas has a significant effect on the signs of alcohol withdrawal syndrome (AWS) and thus might be expected to reduce sleep disturbance during withdrawal. The aim of the present study was to investigate sleep quality during alcohol withdrawal, to evaluate the correlation between sleep quality and the severity of AWS and alcohol craving, and to determine if nitrous oxide treatment does counteract withdrawal's effects on the quality of sleep. Voluntary patients (n = 105) admitted to the A-Clinic detoxification center with AWS were included in the study. The AWS patients were randomly assigned to one of the following 45-minute gas treatments: (1) nitrous oxide/oxygen; (2) normal air/O2; and (3) medical (normal) air. The study was single-blind by design. Sleep quality was assessed after these treatments during the inpatient period; sleep time, sleep efficiency and the fragmentation of sleep were recorded by wrist-worn actigraphs. Severity of AWS was evaluated by the Clinical Institute Withdrawal Assessment of Alcohol Scale (CIWA-Ar) and that of alcohol dependence and craving by the Obsessive Compulsive Drinking Scale [OCDS] and the Severity of Alcohol Dependence Data (SADD) questionnaire. Results The fragmentation index and the time awake while in bed were both much above the reference values for the Finnish population. These values reflect the restless and disturbed night sleep of the subjects. The only statistically significant effects between the treatment groups were found in the correlations of CIWA-Ar (severity of AWS) scores, OCDS-scores (alcohol craving) and coffee consumption, all of which were positively associated with movement time and negatively with total sleep time and sleep efficiency. The sleep quality of patients treated with nitrous oxide gas did not differ from the sleep quality of those treated with normal air. Conclusions The severity of AWS and coffee consumption had the most significant negative impact on sleep quality. According to our results, nitrous oxide gas does not differ from placebo in its effect on sleep quality during alcohol withdrawal.

2011-01-01

162

Indicators of the direct economic impacts due to oil and gas development in the Gulf of Mexico: results of year 1. Volume 3. Exhibits and data  

SciTech Connect

The study investigated the direct employment and salary impacts of oil and gas activities on the Federal Outer Continental Shelf in the Gulf of Mexico during 1984. The study also documented the geographic distribution of these impacts. Primary data for this study were provided by nine major oil and gas operations in the Gulf of Mexico and by several contractors to these companies.

Not Available

1986-01-01

163

Indicators of the direct economic impacts due to oil and gas development in the Gulf of Mexico: results of year 1. Volume 1. Executive summary  

SciTech Connect

The study investigated the direct employment and salary impacts of oil and gas activities on the Federal Outer Continental Shelf in the Gulf of Mexico during 1984. The study also documented the geographic distribution of these impacts. Primary data for the study were provided by nine major oil and gas operations in the Gulf of Mexico and by several contractors to these companies.

Not Available

1986-01-01

164

Indicators of the direct economic impacts due to oil and gas development in the Gulf of Nexico: results of year 1. Volume 2. Narrative  

SciTech Connect

The study investigated the direct employment and salary impacts of oil and gas activities on the Federal Outer Continental Shelf in the Gulf of Mexico during 1984. The study also documented the geographic distribution of these impacts. Primary data for the study was provided by nine major oil and gas operations in the Gulf of Mexico and by several contractors to these companies.

Not Available

1986-01-01

165

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

NASA Astrophysics Data System (ADS)

In much of Africa, the largest fraction of energy consumption occurs within the residential sector and is derived primarily from woodfuels burned in simple stoves with poor combustion characteristics. Many of the products of incomplete combustion (PICs) are damaging to human health, particularly when they are concentrated in poorly ventilated indoor environments. Incomplete combustion also has potentially harmful impacts on the climate. Prevalent PICs include methane, a potent greenhouse gas (GHG) that is among the pollutants subject to controls under the Kyoto Protocol as well as carbon monoxide (CO), non-methane hydrocarbons (NMHCs) and particulate matter (PM), which can all have an effect on climate, but are not subject to controls under Kyoto. In addition, when woodfuels are used at a rate that reduces standing stocks of trees over the medium or long term, the CO2 released by combustion also has an impact. The choice of stove and fuel technology can have a significant impact on the emission of GHGs as well as on human exposure to health damaging pollutants. In this paper we analyze the emissions of different household energy technologies on a life-cycle basis. We use emission factors to estimate the emissions associated with production, distribution and end-use of common household fuels and assess the likely impacts of these emissions on public health and the global environment. We focus largely on charcoal, a popular fuel in many sub-Saharan African countries. Charcoal is produced by heating wood in the absence of sufficient air for complete combustion to occur. This process removes moisture and most of the volatile compounds. The compounds driven off in the process consist of condensable tars as well as many gaseous hydrocarbons, including ~40 g CH4 per kg of charcoal produced. Combining upstream and end-use emissions, every meal cooked with charcoal has 2-10 times the global warming effect of cooking the same meal with firewood and 5-12 times the effect of cooking the same meal with LPG or kerosene. When charcoal is produced in large quantities, as it is in Africa, the net warming effect can exceed the impact from the "modern energy sector" (transportation and industry) by 50-100 percent, even if charcoal is produced on a sustainable cycle so that all of the wood harvested for charcoal production is allowed to regenerate. However, while charcoal may be worse than firewood with respect to greenhouse gas emissions, it is an improvement with respect to exposure to health damaging pollutants, particularly particulate matter (PM). Levels of PM in households using charcoal are over 90 percent lower than households using open wood fires (316 -(159) mg/m3 for households using charcoal in a common improved stove compared to 3764 (360) mg/m3) for households using wood in open fires: mean (standard error)). These differences in exposure are consistent with 30 and 50 percent reductions in the incidence of acute respiratory infection (ARI) in adults and children under 5 respectively. Reconciling the costs and benefits of different household energy technologies creates a difficult policy challenge, particularly with the severe budgetary and resource constraints that household consumers and government agencies face in sub-Saharan Africa.

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

2003-12-01

166

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

167

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

NASA Astrophysics Data System (ADS)

We report mineralogical and noble gas evidence for an ET impact associated with the Younger Dryas (YD) event and the mass extinction of various megafauna throughout the Americas approximately 12,900 years ago. We examined numerous well established, 14C dated Clovis sites across the US including detailed sediment profile analyses at Daisy Cave, CA (DC), Murray Springs, AZ (MS), Topper, SC, and Blackwater Draw, NM (BWD). He, Ne, and Ar analysis of magnetic separates, bulk sediments, HF-acid treated residue, and fullerenes coupled with a detailed mineralogical and compositional analysis of magnetic separates by SEM suggest a marked increase in the accretion of extraterrestrial debris in sediments at the YD boundary layer. A preliminary characterization of the magnetic separates consistently observed across numerous sites indicates an extremely high abundance of relatively unoxidized, trace metal rich metallic grains with extremely unusual compositions (e.g. Pt (5-98%), Sn (25-28%) , Ni (1-11%), and Cu (12-90%). These compositions are not easily explained by ordinary terrestrial processes. A few examples include the YD layer at DC which contains numerous metallic grains including Fe-Ni, Cu-Ni, Fe-Sn-Ni, and Pt grains. Metallic iron grains are observed at BWD and Topper, while the Topper site also contains iron spherules, Fe-Ni metallic grains, and Fe-Ni oxides. At this point there is no evidence for a significant concentration of iron spherules, Fe-Ni oxides nor unusual metallic grains away from the proposed impact layer. The noble gas composition and isotopic ratios of fullerenes located at the YD layers contain trapped He with ET isotopic signatures (0.3-3.5 ncc/g 3He and 3He/4He 30- 220 Ra) while Argon ratios (40Ar/^{36}Ar= 230-255) reflect a mixture of planetary and air components. Bulk sediments were treated with HF acid to remove silicates, leaving a carbonaceous residue. Acid treated residues from two boundary layers contained up to 5 ncc/g 3He and 3He/4He from 15- 374 Ra. The DC acid residue exhibits a significant galactic cosmic ray input with 3He/4He=374-800 Ra. Bulk and magnetic sediments away from the boundary layer contain only 1-10 pcc/g 3He in the bulk sediment with 3He/4He from 0.1 to 4.6 Ra. These are consistent with the background IDP flux. An increase in 3He concentrations (5-8 ncc/g) and 3He/4He (10-25Ra) of magnetic grains is observed near the YDB which likely reflects an increase in the flux of IDPs associated with the impactor. The results indicate that the noble gas carrier is concentrated in the carbonaceous phase. Specifically, helium remains trapped in fullerenes as has been seen in other impact events (e.g. PT). The metallic Fe phase is either relatively devoid of ET noble gases or has been degassed during atmospheric entry.

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

2006-12-01

168

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

NASA Astrophysics Data System (ADS)

We report mineralogical and noble gas evidence for an ET impact associated with the Younger Dryas (YD) event and the mass extinction of various megafauna throughout the Americas approximately 12,900 years ago. We examined numerous well established, 14C dated Clovis sites across the US including detailed sediment profile analyses at Daisy Cave, CA (DC), Murray Springs, AZ (MS), Topper, SC, and Blackwater Draw, NM (BWD). He, Ne, and Ar analysis of magnetic separates, bulk sediments, HF-acid treated residue, and fullerenes coupled with a detailed mineralogical and compositional analysis of magnetic separates by SEM suggest a marked increase in the accretion of extraterrestrial debris in sediments at the YD boundary layer. A preliminary characterization of the magnetic separates consistently observed across numerous sites indicates an extremely high abundance of relatively unoxidized, trace metal rich metallic grains with extremely unusual compositions (e.g. Pt (5-98%), Sn (25-28%) , Ni (1-11%), and Cu (12-90%). These compositions are not easily explained by ordinary terrestrial processes. A few examples include the YD layer at DC which contains numerous metallic grains including Fe-Ni, Cu-Ni, Fe-Sn-Ni, and Pt grains. Metallic iron grains are observed at BWD and Topper, while the Topper site also contains iron spherules, Fe-Ni metallic grains, and Fe-Ni oxides. At this point there is no evidence for a significant concentration of iron spherules, Fe-Ni oxides nor unusual metallic grains away from the proposed impact layer. The noble gas composition and isotopic ratios of fullerenes located at the YD layers contain trapped He with ET isotopic signatures (0.3-3.5 ncc/g 3He and 3He/4He 30- 220 Ra) while Argon ratios (40Ar/36Ar= 230-255) reflect a mixture of planetary and air components. Bulk sediments were treated with HF acid to remove silicates, leaving a carbonaceous residue. Acid treated residues from two boundary layers contained up to 5 ncc/g 3He and 3He/4He from 15- 374 Ra. The DC acid residue exhibits a significant galactic cosmic ray input with 3He/4He=374-800 Ra. Bulk and magnetic sediments away from the boundary layer contain only 1-10 pcc/g 3He in the bulk sediment with 3He/4He from 0.1 to 4.6 Ra. These are consistent with the background IDP flux. An increase in 3He concentrations (5-8 ncc/g) and 3He/4He (10-25Ra) of magnetic grains is observed near the YDB which likely reflects an increase in the flux of IDPs associated with the impactor. The results indicate that the noble gas carrier is concentrated in the carbonaceous phase. Specifically, helium remains trapped in fullerenes as has been seen in other impact events (e.g. PT). The metallic Fe phase is either relatively devoid of ET noble gases or has been degassed during atmospheric entry.

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

2007-05-01

169

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

170

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

171

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

172

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

173

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

174

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

175

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

NASA Astrophysics Data System (ADS)

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

Lakshminarayanan, A. K.; Balasubramanian, V.

2011-02-01

176

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

Federal Register 2010, 2011, 2012, 2013

...CP13-132-000] Transcontinental Gas Pipeline Company; Notice of Availability of the Draft...proposed by Transcontinental Gas Pipeline Company (Transco) in the above-referenced...Aviator Sports & Events Center,3159 Flatbush...

2013-10-11

177

Analyzing the Long-run Impact of the Regional Greenhouse Gas Initiative on the Maryland Power Sector: Oligopoly Analysis  

Microsoft Academic Search

The regional greenhouse gas initiative (RGGI) is a joint effort by a number of northeast states to control for regional CO2 emissions. The objective is to reduce CO2 emissions from the power sector 10% below the current level by 2019 using a cap-and-trade program. The State of Maryland has sponsored an analysis to determine the impacts on Maryland of participating

Yihsu Chen; Dallas Burtraw; Benjamin F. Hobbs; Soora Kim; Karen Palmer; A. Paul; S. Gabriel

2007-01-01

178

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

179

Projection of energy use and greenhouse gas emissions by motor vehicles in China: Policy options and impacts  

Microsoft Academic Search

We project the well-to-wheels (WTW) and tank-to-wheels (TTW) fossil-energy use, petroleum use, and greenhouse gas (GHG) emissions of the road-transport sector in China up to year 2050 and evaluate the effects of various potential policy options with the fuel economy and environmental impacts (FEEI) model (http:\\/\\/www.feeimodel.org\\/). The policies evaluated include (1) vehicle fuel-consumption improvements, (2) dieselization, (3) vehicle electrification, and

Hong Huo; Michael Wang; Xiliang Zhang; Kebin He; Huiming Gong; Kejun Jiang; Yuefu Jin; Yaodong Shi; Xin Yu

2012-01-01

180

Lost in Transmission? Stock Market Impacts of the 2006 European Gas Crisis  

Microsoft Academic Search

Around the turn of the year 2005\\/2006, the Russian freezing of natural gas exports to the Ukraine led to a European gas crisis. Using event study techniques, we first investigate whether the Russian suspension of gas deliveries, the announcement of this suspension as well as its withdrawal had an effect on unsystematic volatility of European energy stocks. Second, we measure

Ulrich Oberndorfer; Dirk Ulbricht; Janina Ketterer

2007-01-01

181

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

182

Gas Processing Economics: The Impact of By-Product Pricing. Topical Report, August 1992-January 1993.  

National Technical Information Service (NTIS)

The sale of by-products extracted during natural gas processing could add significantly to the economics of producing gas. The by-products natural gas liquids (NGLs), helium, sulfur, carbon dioxide (CO2) and nitrogen were examined. The sources of supply a...

C. C. Tannehill R. J. Harrison

1993-01-01

183

Environmental impact assessment: enhanced gas recovery by massive hydraulic fracturing in Lincoln County, West Virginia  

Microsoft Academic Search

The US DOE has contracted with the Columbia Gas Transmission Corp. to share the cost of a field experiment of the Massive Hydraulic Fracturing (MHF) process for natural gas recovery. The project is part of a larger program to develop reservoir stimulation techniques for natural gas within the Devonian Shale formation of the Appalachian region. The experiment will take place

Schnorr

1978-01-01

184

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

185

Impact of exploratory offshore drilling on benthic communities in the Minerva gas field, Port Campbell, Australia.  

PubMed

Changes to benthic infauna caused by exploratory gas drilling operations in the Minerva field were examined experimentally using a BACI (before, after, control, impact) design. Analysis of 72 x 0.1 m2 Smith-McIntyre grab samples obtained from one pre-drilling and three post-drilling periods yielded a diverse fauna consisting of 196 invertebrate species and 5035 individuals. Changes to benthic community structure were assessed using ANOVA and nonmetric multidimensional scaling (MDS). The abundances of two common species (Apseudes sp. 1 and Prionospio coorilla) decreased significantly at the well-head site immediately after drilling. The size of these reductions in abundance ranged between 71% and 88%, and persisted for less than 4 months after drilling. A third common species (Katlysia sp. 1) increased in abundance 200 m east of the well-head following drilling. Most species occurred at densities too low to be analysed individually and so were pooled at higher taxonomic levels. Changes in the abundance of species aggregated by phylum varied, but significant declines in the most abundant phyla (Crustaceans and Polychaetes) of 45-73% were observed at all sites within a 100 m radius of the well-head following drilling. In most cases these changes became undetectable four months after drilling following species recruitments. MDS ordinations confirm that drilling related changes to benthic community structure are most pronounced at stations located closest to the well-head. Additionally, the ordinations indicate that modified communities persist at the well-head for more than 11 months following exploratory drilling. PMID:15465131

Currie, D R; Isaacs, Leanne R

2005-04-01

186

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

187

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

188

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

ERIC Educational Resources Information Center

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

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

189

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

ERIC Educational Resources Information Center

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

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

190

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

191

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

SciTech Connect

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

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

2011-07-01

192

ECPR Standing Group on Regulatory Governance Regulation for competition in European gas markets: the impact of European law and facilitating factors  

Microsoft Academic Search

The liberalisation of European gas markets is leading to a profound restructuring of the natural gas industry. Alongside this, new modes of economic governance are evolving on the European and national levels, triggering harmonisation and market integration through the application of legal provisions and communication instruments. In this paper, we analyse the impact of law on the convergence towards best-practice

Nadine Haase

193

Short-term impacts of nutrient manipulations on leaf gas exchange and biomass partitioning in contrasting 2-year-old Pinus taeda clones during seedling establishment  

Microsoft Academic Search

We conducted a 1-year greenhouse experiment to assess the impact of nutrient manipulations on seedling growth, biomass partitioning, and leaf gas exchange between two fast growing Pinus taeda clones that differed in growth efficiency. After 1 year we observed significant treatment and treatment by clone effects on growth, biomass partitioning, and gas exchange parameters. Fertilization increased total seedling biomass 18%

Michael C. Tyree; John R. Seiler; Chris A. Maier

2009-01-01

194

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

195

IMPACTS OF SEASONALITY ON HYDROGEN PRODUCTION USING NATURAL GAS PRESSURE LETDOWN STATIONS  

Microsoft Academic Search

One of the difficulties associated with the development of a hydrogen economy is the creation of a supply infrastructure. A means for distributed hydrogen generation through a process using the exergy in high pressure natural gas streams has been proposed. The system recovers energy via expansion of natural gas through a turbo-expander at existing pressure reduction systems. Generated electric power

Jesse Maddaloni; Andrew Rowe; Rick Bailey; Duncan McDonald

196

Energy and greenhouse gas impacts of mining and mineral processing operations  

Microsoft Academic Search

Life cycle assessments of the mining and mineral processing of iron ore, bauxite and copper concentrate were carried out, focussing on embodied energy and greenhouse gas emissions. The results showed that loading and hauling make the largest contributions to the total greenhouse gas emissions for the mining and processing of iron ore and bauxite. In the case of copper ore,

T. Norgate; N. Haque

2010-01-01

197

Environmental Impact Assessment: Enhanced Gas Recovery by Massive Hydraulic Fracturing in Lincoln County, West Virginia.  

National Technical Information Service (NTIS)

The US DOE has contracted with the Columbia Gas Transmission Corp. to share the cost of a field experiment of the Massive Hydraulic Fracturing (MHF) process for natural gas recovery. The project is part of a larger program to develop reservoir stimulation...

J. K. Schnorr

1978-01-01

198

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

Microsoft Academic Search

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

D. R. Blake; F. S. Rowland

1995-01-01

199

Natural Gas Price Impact on Irrigated Agricultural Water Demands in the Texas Panhandle Region  

Microsoft Academic Search

Rising natural gas prices led to a noticeable decrease in irrigation; however, the magnitude of the reduction in water pumped is unknown. The objective of this study was to estimate reduction in irrigation water pumped resulting from high natural gas prices in the Northern Texas High Plains. Farm Service Agency irrigated acreage data were utilized to analyze eight major crop

Bridget Guerrero; Stephen Amosson; Thomas Marek; Lal Almas

2006-01-01

200

The Impact of High Oil Prices on Global and Regional Natural Gas and LNG Markets  

Microsoft Academic Search

Oil prices are notoriously hard to predict, but they are an important input in many energy and economic models. This paper explores the effects of different oil price assumptions on natural gas markets (production, consumption, prices in different regions) in the International Natural Gas Model (INGM). Three cases from the INGM are presented: a reference case, a high oil price

William Pepper Vineet Aggarwal Justine Barden

2009-01-01

201

Export restraints on russian natural gas and raw timber : what are the economic impacts ?  

Microsoft Academic Search

Export restraints by the Russian Federation on natural gas and timber have been the source of major controversy between the European Union and the Russian Federation. The analysis of this paper suggests that the export restraints in natural gas very substantially benefit Russia. On the other hand, in raw timber the analysis suggests that a substantial reduction of Russian export

David G. Tarr

2010-01-01

202

Environmental impact assessment: stimulation of gas recovery in the devonian shale, Wetzel County, West Virginia  

Microsoft Academic Search

The Morgantown Energy Research Center of the U.S. Department of Energy (DOE) has contracted with Mobay Corporation to share the cost of hydraulic stimulation of the Devonian Shale at a site in Wetzel County owned by Mobay. This contract is one of several awarded to natural gas producers by DOE to test methods to increase gas recovery from the Devonian

OBanion

1978-01-01

203

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

204

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

Microsoft Academic Search

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

Castaldini

1990-01-01

205

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

206

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

207

Impacts of Gas-phase Chemical Mechanisms on Modeled Responses of Ozone and Fine Particulate Matter to Emission Changes  

NASA Astrophysics Data System (ADS)

Two air pollutants of most concern are ozone and fine particulate matter (i.e., PM2.5; particulate matter with an aerodynamic diameter less than 2.5 ?m) due to their adverse human health effects. Gas-phase chemical mechanisms are one of the important components in regional air quality models and applied to describe the formation of air pollutants such as ozone and secondary PM2.5. Modeled responses of air pollutant concentrations to precursor emission changes (i.e., sensitivities) provide useful information for developing air pollution mitigation strategies and are expected to be affected by gas-phase chemical mechanisms chosen for air quality simulations. The goal of this study is to investigate impacts of gas-phase chemical mechanisms on modeled responses of ozone and PM2.5 concentrations to emission reductions over the eastern United States. We used the U.S. Environmental Protection Agency's regional air quality model, Community Multiscale Air Quality Model (CMAQ) version 4.7.1, to simulate three-dimensional gridded concentrations of ambient ozone, PM2.5 and other air pollutants during three summer months (June, July and August) in 2007. A uniform grid of 12 by 12 km horizontal cells with 34 vertical layers was employed in the air quality simulations. Two gas-phase chemical mechanisms (CB-05; Carbon Bond Mechanism, version V and SAPRC-99; Statewide Air Pollution Research Center, version 99) were used in the regional air quality simulations. The preliminary results show that modeled responses of peak ozone levels to emission changes could be affected by the gas-phase chemical mechanism chosen in air quality modeling. The effects of gas-phase chemical mechanisms on modeled responses of PM2.5 to emission changes are small. Final results of this modeling study and related discussion will be presented at the conference.

Liao, Kuo-Jen

2013-04-01

208

Impact on gas distribution companies of federally approved special marketing programs  

SciTech Connect

The Federal Energy Regulatory Commission (FERC) responded to changing conditions in the natural gas industry with several different approaches to enhance the marketability of natural gas. The Commission has taken steps to promote increased use of natural gas, and has attempted to experiment with programs designed to retain or regain loads lost to competing fuels. Whether these efforts will be successful remains to be seen, but it is inevitable that any one program may adversely affect certain distributors more than others. Distribution companies have little alternative but to participate in shaping FERC decisions. The Commission should encourage agency arrangements which require cooperation and ultimate supervision by FERC to achieve price reduction. 105 references.

Tiano, J.R.; Bonnifield, R.P.

1984-01-01

209

75 FR 16450 - Kern River Gas Transmission Company; Notice of Availability of the Draft Environmental Impact...  

Federal Register 2010, 2011, 2012, 2013

...36-inch-diameter natural gas pipeline loop \\1\\ extending southwest...adjacent to an existing pipeline and connected to it at both...used to clean and dry a pipeline and/or to inspect it for damage or...

2010-04-01

210

Assessing Economic Impacts of Greenhouse Gas Mitigation. Summary of a Workshop.  

National Technical Information Service (NTIS)

Many economic models exist to estimate the cost and effectiveness of different policies for reducing greenhouse gas (GHG) emissions. Some approaches incorporate rich technological detail, others emphasize the aggregate behavior of the economy and energy s...

D. Vollmer

2009-01-01

211

Electricity price impacts of alternative Greenhouse gas emission cap-and-trade programs  

SciTech Connect

Limits on greenhouse gas emissions would raise the prices of the goods and services that require such emissions for their production, including electricity. Looking at a variety of emission limit cases and scenarios for selling or allocating allowances to load-serving entities, the authors estimate how the burden of greenhouse gas limits are likely to be distributed among electricity consumers in different states. (author)

Edelston, Bruce; Armstrong, Dave; Kirsch, Laurence D.; Morey, Mathew J.

2009-07-15

212

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

213

76 FR 52655 - Pacific Gas and Electric Company; Notice of Availability of the Final Environmental Impact...  

Federal Register 2010, 2011, 2012, 2013

...Environmental Impact Statement for the Kilarc-Cow Creek Hydroelectric Project In accordance...requesting surrender of the Kilarc-Cow Creek Project (FERC No. 606) license. The project is located on Old Cow Creek, South Cow Creek, and...

2011-08-23

214

75 FR 37429 - Pacific Gas and Electric Company; Notice of Availability of the Draft Environmental Impact...  

Federal Register 2010, 2011, 2012, 2013

...Environmental Impact Statement for the Kilarc-Cow Creek Hydroelectric Project and Announcing...requesting surrender of the Kilarc-Cow Creek Project (FERC No. 606) license. The project is located on Old Cow Creek, South Cow Creek, and...

2010-06-29

215

Impact of chlorine dioxide gas sterilization on nosocomial organism viability in a hospital room.  

PubMed

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

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

2013-06-21

216

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

PubMed

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

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

2012-09-17

217

Impact of the Resource Conservation and Recovery Act on Landfill Gas Utilization.  

National Technical Information Service (NTIS)

A survey was made to determine the number of landfills and their sizes that would be affected by the gas criteria of the RCRA Open Dump Inventory project. The cost-effectiveness of active systems and hybrid systems were also determined for landfills repre...

1983-01-01

218

The holistic impact of integrated solid waste management on greenhouse gas emissions in Phuket  

Microsoft Academic Search

Continually increasing amounts of municipal solid waste (MSW) and the limited capacity of the existing waste management system in Phuket have led to the consideration of integrated waste management system (IWMS). Life cycle assessment (LCA) was employed to compare the greenhouse gas emissions expressed as global warming potential (GWP) of the existing waste management system (the base scenario) and other

Chalita Liamsanguan; Shabbir H. Gheewala

2008-01-01

219

Assessment of saltwater intrusion impact on gas exchange behavior of Louisiana Gulf Coast wetland species  

Microsoft Academic Search

A review of gas exchange responses of wetland plants to salinity is presented for several species representative of different wetland habitats extending along water level and salinity gradients in the Louisiana Gulf Coast, U.S.A. The information was synthesized from earlier plant physiological response studies. Vegetation examined represent a broad range of sensitivity to salt, including brackish marsh, freshwater marsh, and

S. R. Pezeshki; R. D. DeLaune

1989-01-01

220

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

Microsoft Academic Search

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-

1998-01-01

221

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

Microsoft Academic Search

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 SOâ per day, during eruptive pauses, to as much as 1850 metric tonnes per day during actively erupting periods, along with lesser amounts

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

1994-01-01

222

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

223

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.

224

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)

1994-01-01

225

Impact of distributed and independent power generation on greenhouse gas emissions: Sri Lanka  

Microsoft Academic Search

Sri Lanka has a hydropower dominated power system with approximately two thirds of its generation capacity based on large hydro plants. The remaining one third are based on oil fired thermal generation with varying technologies, such as oil steam, Diesel, gas turbines and combined cycle plants. A significant portion of this capacity is in operation as independent power plants (IPPs).

Priyantha D. C Wijayatunga; W. J. L. S Fernando; Ram M Shrestha

2004-01-01

226

Onshore Impacts of Oil and Gas Development in Alaska. Volume II. Methodology Appendices.  

National Technical Information Service (NTIS)

A general model of oil and gas development is analyzed and each of the components is then defined. The definitions are used as the basis for making a series of assumptions that are essentially a set of parameters of the components. An appropriate set of a...

1975-01-01

227

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.

228

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

229

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

230

A new impact test for the identification of a dynamic crack propagation criterion using a gas-gun device  

NASA Astrophysics Data System (ADS)

The modelling of damage and fracture behaviour under high rates of loadings for metallic structures presents the more and more interests for engineering design, especially for crash phenomena. In order to perform a numerical simulation of such phenomena a crack propagation criterion must be identified using adapted laboratory tests. The objective of this paper is to present a new impact test intended for the identification of a cohesive crack criterion implemented into a home-made FEM code based on Extended Finite Element Method. Therefore, a double-notched specimen is impacted using a gas-gun device in order to obtain different crack paths depending on projectile speed. A post-impact macro-photographic observation allows to measure the crack path, the angles and the advancing length. These experimental results are used as input responses in the identification procedure for determining the crack cohesive criterion parameters. Some experimental results, for an aluminium alloy crack criterion identification, are presented to illustrate the proposed approach.

Nistor, I.; Pantalé, O.; Caperaa, S.

2006-08-01

231

Impacts of oil and gas development on the recreation and tourism off the Florida straits  

SciTech Connect

The study was undertaken for the purpose of addressing potential problems of OCS activities on tourism and recreation in Monroe County, Florida. The strategic objective of the study was to develop a model to simulate the effects of various OCS activities on tourism visitation, expenditures, and regional gross economic impacts.

Bell, F.

1991-05-01

232

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

Microsoft Academic Search

One of the goals of the US Consumer Assistance to Recycle and Save (CARS) Act of 2009, more commonly known as 'Cash for Clunkers', was to improve the US vehicle fleet fuel efficiency. Previous studies of the program's environmental impact have focused mainly on the effect of improved fuel economy, and the resulting reductions in fuel use and emissions during

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

2010-01-01

233

A Scientific Review of the Impact of UK Ruminant Livestock on Greenhouse Gas Emissions  

Microsoft Academic Search

Climate change is a subject of global environmental concern. The UK has seen a progressive strengthening of political resolve to address the problems associated with emissions of greenhouse gases (GHGs), principally carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Although agriculture globally, and ruminant livestock production in particular, is a net contributor to GHG emissions, generalizations about impacts on

Alan Hopkins; Matt Lobley

2009-01-01

234

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

Microsoft Academic Search

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

Adam Robert Brandt

2008-01-01

235

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

Microsoft Academic Search

In much of Africa, the largest fraction of energy consumption occurs within the residential sector and is derived primarily from woodfuels burned in simple stoves with poor combustion characteristics. Many of the products of incomplete combustion (PICs) are damaging to human health, particularly when they are concentrated in poorly ventilated indoor environments. Incomplete combustion also has potentially harmful impacts on

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

2003-01-01

236

Impact of biochar on manure carbon stabilization and greenhouse gas emissions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous studies indicate that biochar additions sometimes increase soil respiration and carbon dioxide emissions, which could partially offset carbon (C) credits associated with soil biochar applications. Little is known, however, about the impact of biochar on the mineralization of manure in soil ...

237

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

238

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

239

Bibliographies of the National Marine Fisheries Service's Assessments of Impacts of the Buccaneer Gas and Oil Field and of Brine Disposal from Salt Domes of the Strategic Petroleum Reserve.  

National Technical Information Service (NTIS)

Contents: Bibliography of the National Marine Fisheries Service's assessment of impacts of buccaneer gas and oil field; Bibliography of the National Marine Fisheries Service's assessment of impacts of brine disposal from salt domes of the strategic petrol...

C. W. Caillouet

1984-01-01

240

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

241

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

SciTech Connect

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

Not Available

1993-02-26

242

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

243

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

2013-10-02

244

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

245

Efficiency Improvement of Small Gas Bearing Turbines - Impact on Standard Helium Liquefier Performance  

NASA Astrophysics Data System (ADS)

Radial turbine design is dictated by criteria like specific speed and/or velocity ratios. For small capacity plants the size of the turbine wheel needs to be reduced and thus the rotational speed increased in order to reach a high efficiency. The design of a small turbine, taking mechanical and manufacturing criteria into account, will be presented as well as the impact of reducing size (lower Reynolds number, larger wheel relative clearance and blockage, etc.) An overview of the technical and operational improvements is presented as well as the first test results. The impact of the new turbine design on the capacity of standard liquefiers is calculated and analyzed. Additional tests on a standard plant with a liquefaction capacity of 65 l/h are being performed to confirm the calculated results.

Cretegny, D.; Schönfeld, H.; Decker, L.; Löhlein, K.

2004-06-01

246

The regional economic impact of reducing greenhouse gas emissions: Western Australia  

Microsoft Academic Search

This study analyses the general-equilibrium impacts of an international climate change response policy on the economy of Western Australia (WA), one of the most mining-based and energy-intensive states of Australia. It finds that emissions would fall by up to 11% from the base level in WA. However, such environmental benefits emanate at some costs to the state economy; in terms

Helal Ahammad; Kenneth W. Clements; Qiang Ye

2001-01-01

247

A comparison of particle impact in gas-solid and liquid-solid erosion  

Microsoft Academic Search

The sizes of craters formed on cylindrical, electro-polished, OFHC copper erosion specimens subjected to impact by closely-sized glass beads, average diameter 540 ?m, suspended in diesel oil in a slurry-pot erosion tester operating at nominal rotation speeds of 18.7, 14.0 and 9.35 m s?1 have been compared with those produced in an identical apparatus operating at the same speeds, in

Hector McI Clark

1995-01-01

248

Impact of Power Generation Mix on Life Cycle Assessment and Carbon Footprint Greenhouse Gas Results  

Microsoft Academic Search

SummaryThe mix of electricity consumed in any stage in the life cycle of a product, process, or industrial sector has a significant effect on the associated inventory of emissions and environmental impacts because of large differences in the power generation method used. Fossil?fuel?fired or nuclear?centralized steam generators; large?scale and small?scale hydroelectric power; and renewable options, such as geothermal, wind, and

Joe Marriott; H. Scott Matthews; Chris T. Hendrickson

2010-01-01

249

Numerical Study on the Effect of Substrate Angle on Particle Impact Velocity and Normal Velocity Component in Cold Gas Dynamic Spraying Based on CFD  

Microsoft Academic Search

Numerical study was conducted to investigate the effect of substrate angle on particle impact velocity and normal velocity\\u000a component in cold gas dynamic spraying by using three-dimensional models based on computational fluid dynamics. It was found\\u000a that the substrate angle has significant effect on particle impact velocity and normal velocity component. With increasing\\u000a the substrate angle, the bow shock strength

Shuo Yin; Xiao-Fang Wang; Wen-Ya Li; Bao-Peng Xu

2010-01-01

250

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

251

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

252

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

253

Forest Conversion: Impact on Total Greenhouse Gas Balance and Mitigation Strategies  

NASA Astrophysics Data System (ADS)

At present, large efforts are undertaken in wide parts of Germany and Europe to create the scientific and socio-economic data basis that can be used by political decision makers and foresters for developing and implementing a future-oriented forestry allowing a sustainable use of forests under changing environmental conditions (e.g. climate change and increasing N-deposition). Different forest management strategies are available to initiate forest conversion, in particular "clear-cutting" and "selective cutting". Although these forest conversion strategies are widely used, little information is available about their individual effects on the biosphere-atmosphere greenhouse gas exchange and on the total greenhouse gas balance (CO2 + N2O + CH4) of the system. The results obtained from continuous long-term measurements (1999-2005) of N2O and CH4 fluxes from the soil of different experimental sites (untreated spruce control site, selective-cutting site, clear-cut site) at the Höglwald Forest, Bavaria, Germany show that conversion of N-affected forest plantations by clear-cutting leads to an enormous release of N2O from the soil into the atmosphere, not only during the first year after treatment, but for several consecutive years, and simultaneously to a marked reduction in the uptake capacity of the soil for CH4. Although selective cutting also enhances the source strength for N2O and reduces the CH4 sink strength, respectively, the effects are by far less pronounced as compared to clear-cutting. Establishing the total greenhouse gas balance (CH4, N2O, CO2) for a forest rotation time of 80 years by considering the huge differences in global warming potentials of these greenhouse gases revealed that the enhanced N2O emissions and reduced CH4 deposition rates due to different forest conversion practices can compensate CO2 sequestration benefits to a significant extent.

Papen, H.; Brueggemann, N.; Gasche, R.; Butterbach-Bahl, K.

2006-12-01

254

Assessing environmental impact from gas and oil exploration in the SW Barents Sea using benthic foraminiferal assemblages  

NASA Astrophysics Data System (ADS)

During the last decades petroleum industry and shipping activities have increased in the SW Barents Sea. Oil exploration wells were drilled in the 1980s with production starting in 2007. These activities are projected to expand in the coming years. As part of the Northern Environmental Waste Management (EWMA) project, a competence cluster for petroleum industry related waste handling, we investigate the impacts of enhanced anthropogenic activities on benthic foraminiferal assemblages in the SW Barents Sea. Sediment cores (0-20 cm) from sites in proximity to two oil- and gas fields are under investigation. These sediment cores, dated with the 210Pb method, represent the last 90 to 150 years. Both dead and living benthic foraminifera (100 µm-1 mm) were counted to elucidate differences in foraminiferal assemblages between pre-impact and recent conditions. In addition, the heavy metal concentrations, persistent organic pollutant (POP) concentrations, grain size and total organic content (TOC) of the sediment cores have been analyzed. Pollution levels of the surface sediments (0-1 cm) are of background to good level (level I-II) according to the definitions of the Water Framework Directorate (WFD). Patterns in living benthic foraminiferal assemblages identified in the sea floor surface sediments, are the result of natural environmental changes such as depth, water mass and sediment composition. Further downcore (1-20 cm) pollution levels are in general of background environmental status (WFD level I). However, at some depth intervals, especially in sediment cores from the near proximity of the oil- and gas- fields, pollution levels are slightly enhanced (WFD level II). Further work will include statistical comparison of dead and living foraminiferal assemblages with sediment pollution levels, sediment properties, and oceanographic conditions. This research contributes to the development of foraminifera as a useful bio-monitoring technique for the Arctic region as industrial activities increase in the coming years.

Dijkstra, N.; Junttila, J.; Husum, K.; Carroll, J.; Hald, M.

2012-04-01

255

Optimization of burners for firing solid fuel and natural gas for boilers with impact pulverizers  

SciTech Connect

The design of a burner with preliminary mixing of fuel and air for alternate or joint firing of coal and natural gas on a boiler is described. The burner provides steady ignition and economical combustion of coal, low emission of NOx in both operating modes, and possesses an ejecting effect sufficient for operation of pulverizing systems with a shaft mill under pressure. The downward inclination of the burners makes it possible to control the position of the flame in the furnace and the temperature of the superheated steam.

G.T. Levit; V.Ya. Itskovich; A.K. Solov'ev (and others) [ORGRES Company (Russian Federation)

2003-01-15

256

Impact of regulations - after federal leasing - on Outer Continental Shelf oil and gas development  

SciTech Connect

The Outer Continental Shelf potentially can provide the nation with significant future oil and gas resources. But, the full potential will not be realized unless: various federal agencies involved issue permits and complete other authorization actions within a standard, reasonable time which GAO believes should be a maximum of 90 days; coastal states are encouraged to develop processes for local reviews and issuing permits which are more timely and uniform with federal processes; credibility of the environmental review process is more clearly established to minimize challenges and delays; and more federal leadership and agency expertise are focused on Outer Continental Shelf activities in the years ahead.

Staats, E.B.

1981-02-27

257

Amperometric Enzyme-based Gas Sensor for Formaldehyde: Impact of Possible Interferences  

PubMed Central

In this work, cross-sensitivities and environmental influences on the sensitivity and the functionality of an enzyme-based amperometric sensor system for the direct detection of formaldehyde from the gas phase are studied. The sensor shows a linear response curve for formaldehyde in the tested range (0 - 15 vppm) with a sensitivity of 1.9 ?A/ppm and a detection limit of about 130 ppb. Cross-sensitivities by environmental gases like CO2, CO, NO, H2, and vapors of organic solvents like methanol and ethanol are evaluated as well as temperature and humidity influences on the sensor system. The sensor showed neither significant signal to CO, H2, methanol or ethanol nor to variations in the humidity of the test gas. As expected, temperature variations had the biggest influence on the sensor sensitivity with variations in the sensor signal of up to 10 % of the signal for 5 vppm CH2O in the range of 25 - 30 °C.

Achmann, Sabine; Hammerle, Martin; Moos, Ralf

2008-01-01

258

Impact of Tillage, Crop Sequence and N-fertilization on Trace Gas Exchange in an Irrigated Agroecosystem in Northeastern Colorado  

NASA Astrophysics Data System (ADS)

A long-term study was initiated in 1999 to investigate the potential of no-till cropping systems to sequester CO2 while maintaining crop production in irrigated agriculture in northeastern Colorado. As the impact of agricultural management changes on trace gas fluxes are not well understood, we began measuring the soil-atmosphere exchange of CO2, CH4 and N2O during the spring of 2002. Fluxes were measured, using vented chambers, one to three times per week, year round, within plots that are continuously cropped to corn under conventional plow tillage (CT), within no-till continuous corn plots (NT), and within a NT corn-soybean rotation. Plots were fertilized at planting with rates of 0, 134 and 202 kg N ha-1. In 2002, all plots in which trace gas fluxes were measured were cropped with corn that was planted on April 26 and harvested on November 5, 2002. From planting until early April 2003 no tillage or N-fertilization effects on CH4 flux were observed, with the soil serving as a small CH4 source during the irrigation season and a small sink during the winter. Converting to NT did not increase N2O emissions while N2O emissions increased in response to fertilizer N supply. N2O emissions were higher in plots that had been cropped to soybeans the year before. On January 2, 2003 the CT plots were plowed. Even though soil temperature was near zero oC, CO2 fluxes averaged 33+/-5 mg C m-2 hr-1 in CT plots compared to 4.8+/-1.4 in NT plots the day after plowing. The first year of trace gas flux measurements suggest that converting conventionally plowed soils to no-till decreases soil CO2 loss and does not increase N2O or CH4 flux.

Mosier, A. R.; Halvorson, A. D.

2003-12-01

259

The impact of subosnic aviation on the gas-phase composition of the upper troposphere  

NASA Astrophysics Data System (ADS)

The Global Modeling Initiative (GMI) has integrated a modular, three-dimensional chemistry-transport model (CTM) for use in the assessment of anthropogenic impacts on the atmosphere, as well as evaluating uncertainties and variability in model predictions due to adoption of different meteorological, physical, and chemical processes. We have carried out simulations of the impact of a hypothetical future subsonic fleet with fuel usage twice the amount consumed in 1995, equivalent to about 0.5 TgN/year in NOx emissions. The simulations have utilized three different sets of meteorological fields, obtained from the NASA/Goddard Data Assimilation Office (DAO, for 1997 conditions), the Middle Atmosphere Community Climate Model, version 3 (MACCM3), and the Goddard Institute for Space Studies, version II' (GISS II'). All other model inputs and boundary conditions are kept constant. Although the spatial distribution of the perturbation is different for the three fields utilized, zonal-average perturbations are fairly robust, yielding about 3% increase in ozone at Northern mid-latitudes for the extra NOx emitted. Comparison of these results to previous assessments will be discussed.

Rodriguez, J.; Bergmann, D.; Logan, J.; Baughcum, S.; Rotman, D.

2003-04-01

260

The relative impacts of greenhouse gas and aerosol climate forcing on mountain glacier melt at the third pole  

NASA Astrophysics Data System (ADS)

The third pole region resides within a hot spot for atmospheric brown clouds owing to the widespread emissions of dust, soot, and organic carbon aerosols in South and East Asia. As much as one-half of the regional climate warming over South Asia in the later 20th and early 21st centuries has been attributed to the direct radiative heating of the troposphere by aerosol solar absorption. The other half is attributed to the global greenhouse gas forcing. While the increase in temperature and infrared back radiation attributable to greenhouse gas warming is expected to accelerate melting of Himalayan glaciers, aerosol radiative forcing, and the climate response to it, contribute a host of additional impacts on mountain glaciers, many of which exacerbate the melting. These impacts include atmospheric warming, increased infrared back radiation, reduced surface insolation, surface albedo modification by soot deposition, and reductions in monsoon precipitation. The contributions of each of these effects upon melting of Himalayan mountain glaciers is explored in a glacier mass model based on energy balance calculations. The surface energy balance from the base to the top of several glaciers is calculated based on remote sensing and in-situ time series of radiative fluxes and precipitation. The model is calibrated against recent in-situ measurements of glacier mass balance and equilibrium altitude where available. Perturbations to the radiative fluxes and precipitation are then imposed on the mass balance calculations based on published estimates of the aerosol radiative forcing magnitudes and observed changes in regional temperature and precipitation over the modern era. In light of the substantial uncertainty surrounding regional forcing values and mountain glacier characteristics, the study emphasizes sensitivity studies comparing the relative responses of glaciers to the components of aerosol and greenhouse gas forcing mentioned above. Of particular interest are: (a) the balance between aerosol radiative warming of the atmosphere and aerosol radiative cooling of the surface; (b) estimates of the magnitude of soot deposition required to cause melting rates comparable to those caused by regional warming; and (c) the relative contributions of aerosol warming of the atmosphere and the associated decrease in monsoon precipitation to total glacier mass change. The modeling framework presented here is offered as a means of providing additional quantitative constraints on recent speculation about the role of black carbon aerosols and the fate of the Himalayan glaciers.

Wilcox, E. M.

2010-12-01

261

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

NASA Astrophysics Data System (ADS)

The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA’s requirements for cellulosic biofuel if the leakage rate is higher than 9.7%. For the small biorefinery, there are no GHG emission benefits in the production of biomethane if the leakage rate is higher than 11.5%. Compared to system expansion, the use of energy and market value allocation methods generally results in higher estimates of GHG emissions for the primary biorefinery products (i.e., smaller reductions in emissions compared to reference systems).

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

2013-03-01

262

The impact of oxygen on the morphology of gas-phase prepared Au nanoparticles  

SciTech Connect

We present an easy procedure for the synthesis of single crystalline gold nanoparticles with a mean diameter of 4 nm using a DC-sputtering in an argon-oxygen gas mixture. Morphology population statistics have been determined to quantify the influence of oxygen. It is found that the particles undergo a structural transition from predominantly icosahedral to single crystalline particles with increasing amount of oxygen. Aberration-corrected high-resolution transmission electron microscopy investigation proves that likewise prepared single crystalline nanoparticles are defect and oxygen free. In contrast, the icosahedral particles prepared with pure argon show the presence of edge dislocations pointing to an energetic disfavoring already at these relatively small particle sizes. This morphology control of clean and uncovered Au nanoparticles provides a high application potential, e.g., for studying the influence of the particle morphology on plasmonic and catalytic properties.

Pohl, D.; Surrey, A.; Schultz, L. [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany); TU Dresden, Institute of Condensed Matter Physics, D-01062 Dresden (Germany); Rellinghaus, B. [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany)

2012-12-24

263

Validated semiquantitative\\/quantitative screening of 51 drugs in whole blood as silylated derivatives by gas chromatography-selected ion monitoring mass spectrometry and gas chromatography electron capture detection  

Microsoft Academic Search

A comprehensively validated procedure is presented for simultaneous semiquantitative\\/quantitative screening of 51 drugs of abuse or drugs potentially hazardous for traffic safety in serum, plasma or whole blood. Benzodiazepines (12), cannabinoids (3), opioids (8), cocaine, antidepressants (13), antipsychotics (5) and antiepileptics (2) as well as zolpidem, zaleplon, zopiclone, meprobamate, carisoprodol, tizanidine and orphenadrine and internal standard flurazepam, were isolated by

Teemu Gunnar; Sirpa Mykkänen; Kari Ariniemi; Pirjo Lillsunde

2004-01-01

264

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

Microsoft Academic Search

This article develops a formal model for comparing the cost structure of the two main transport options for natural gas: liquefied natural gas (LNG) and pipelines. In particular, it evaluates how variations in the prices of natural gas and greenhouse gas emissions affect the relative cost-efficiency of these two options. Natural gas is often promoted as the most environmentally friendly

Marte Ulvestad; Indra Overland

2012-01-01

265

Gulf of Mexico OCS Oil and Gas Lease Sale: 2012. Final Supplemental Environmental Impact Statement. Volume 2: Chapters 5-8, Appendices, and Keyword Index.  

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

266

Gulf of Mexico OCS Oil and Gas Lease Sale: 2012. Final Supplemental Environmental Impact Statement. Volume 1: 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

267

An assessment of pollution impacts due to the oil and gas industries in the Pechora basin, north-eastern European Russia  

Microsoft Academic Search

The chemical composition of terricolous lichens, top-soil and abundance and diversity of lichen communities were assessed at eight sites in the Pechora basin during the summer of 2000 and 2001 to assess local impacts of oil and gas operations. Sites close to industrial areas were compared with areas considered to be pristine. The broad objective of the study was to

Tony R. Walker; Peter D. Crittenden; Scott D. Young; Tatyana Prystina

2005-01-01

268

An assessment of pollution impacts due to the oil and gas industries in the Pechora basin, north-eastern European Russia  

Microsoft Academic Search

The chemical composition of terricolous lichens, top-soil and abundance and diversity of lichen communities were assessed at eight sites in the Pechora basin during the summer of 2000 and 2001 to assess local impacts of oil and gas operations. Sites close to industrial areas were compared with areas considered to be pristine. The broad objective of the study was to

Tony R. Walker; Peter D. Crittenden; Scott D. Young; Tatyana Prystina

2006-01-01

269

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

270

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

271

Impact of process design on greenhouse gas (GHG) generation by wastewater treatment plants.  

PubMed

The overall on-site and off-site greenhouse gas emissions by wastewater treatment plants (WWTPs) of food processing industry were estimated by using an elaborate mathematical model. Three different types of treatment processes including aerobic, anaerobic and hybrid anaerobic/aerobic processes were examined in this study. The overall on-site emissions were 1952, 1992, and 2435 kg CO2e/d while the off-site emissions were 1313, 4631, and 5205 kg CO2e/d for the aerobic, anaerobic and hybrid treatment systems, respectively, when treating a wastewater at 2000 kg BOD/d. The on-site biological processes made the highest contribution to GHG emissions in the aerobic treatment system while the highest emissions in anaerobic and hybrid treatment systems were obtained by off-site GHG emissions, mainly due to on-site material usage. Biogas recovery and reuse as fuel cover the total energy needs of the treatment plants for aeration, heating and electricity for all three types of operations, and considerably reduce GHG emissions by 512, 673, and 988 kg CO2e/d from a total of 3265, 6625, and 7640 kg CO2e/d for aerobic, anaerobic, and hybrid treatment systems, respectively. Considering the off-site GHG emissions, aerobic treatment is the least GHG producing type of treatment contrary to what has been reported in the literature. PMID:19375775

Bani Shahabadi, M; Yerushalmi, L; Haghighat, F

2009-03-11

272

Examination of Enceladus Plume Variability and the Impact on Magnetospheric Neutral Gas Distribution  

NASA Astrophysics Data System (ADS)

The neutral particle dominance over charged particles in Saturn's magnetosphere was evident prior to Cassini arrival at Saturn in 2004. However, the observation of active plumes emanating from the southern pole of the small icy moon, Enceladus provided key information for understanding particle sources and dynamics in the magnetospheric region. Estimates show this 252 km radius moon is likely the dominant source of particles in the magnetosphere producing 1027 to 1028 neutral water molecules per second. Cassini has flown through the plumes on several occasions which appear to indicate variability in this source rate. For this research, we use Cassini CAPS, MIMI and INMS observations during these encounters to constrain our 3-D multi-species neutral particle model to estimate the plume source rate, ejection velocity and ejection angle for three Enceladus encounters (E2, E3 & E5). We also show evidence for plume source rate variability of a at least a factor of four over approximately 6 months and the impact this amount of variability has on global neutral (H2O, OH and O) particle densities.

Smith, Howard T.; Johnson, R. E.; Perry, M.; Mitchell, D. G.; McNutt, R.; Young, D. T.

2009-09-01

273

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

274

Omega-3 index determined by gas chromatography with electron impact mass spectrometry.  

PubMed

Omega-3 index is a relatively new concept, defined as the sum of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) expressed as a percentage of the total fatty acids in red blood cell membranes. This index reflects medium to long-term intake of omega-3 polyunsaturated fatty acids and could be a useful tool in epidemiological studies. The standard technique used for fatty acid analysis and quantification has been gas chromatography (GC) with flame ionization detection. This method is robust and has good precision and sensitivity. However, a major disadvantage is inability to confirm spectrometrically the identity of fatty acids detected, which is important especially in complex biological samples. The current study measures omega-3 index in 12 healthy human volunteers using GC-mass spectrometry (MS). Both the intra-assay and day-to-day variations were well within 5% with linearity of response extending to a concentration of 250 microg/ml (830 micromol/L) of EPA. The limit of detection of EPA was 0.36 microg/ml (1.2 micromol/L). About 25 fatty acids were consistently detected in red blood cells from healthy volunteers including cis and trans isomers. The omega-3 index ranged from 2.4% to 6.2% among the 12 volunteers examined and there was no difference between samples taken in the fasting and postprandial states. EPA and DHA concentrations ranged from 3.53 to 105.89 microg/ml (11.7-350 micromol/L) and 12.19 to 214.42 microg/ml (37.1-652.7 micromol/L), respectively. Thus a GC-MS method has been developed for measuring the omega-3 index. Further studies are required to determine the role of this index as a predictor of disease. PMID:19376692

Abu, E O; Oluwatowoju, I

2009-04-18

275

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

NASA Astrophysics Data System (ADS)

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 variety of metal targets (gold, silver, indium, iron, rhodium and molybdenum) are presented. Over the range 0957-0233/10/1/011/img4, the ionization yields are found to be similar to within a factor of 20 at low velocity and converge to within a factor of five at high velocity. The light gas gun is used to investigate the volumes of craters in metal targets for impacts of 1 mm diameter stainless steel spheres on aluminium at velocities in the range 0957-0233/10/1/011/img5. For normal incidence the crater volume scales with the square of the impact velocity. For oblique impacts at a fixed velocity 0957-0233/10/1/011/img6 it is found that the crater volume scales with the cosine of the impact angle.

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

1999-01-01

276

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

277

Impacts of ocean acidification on respiratory gas exchange and acid-base balance in a marine teleost, Opsanus beta.  

PubMed

The oceanic carbonate system is changing rapidly due to rising atmospheric CO(2), with current levels expected to rise to between 750 and 1,000 ?atm by 2100, and over 1,900 ?atm by year 2300. The effects of elevated CO(2) on marine calcifying organisms have been extensively studied; however, effects of imminent CO(2) levels on teleost acid-base and respiratory physiology have yet to be examined. Examination of these physiological processes, using a paired experimental design, showed that 24 h exposure to 1,000 and 1,900 ?atm CO(2) resulted in a characteristic compensated respiratory acidosis response in the gulf toadfish (Opsanus beta). Time course experiments showed the onset of acidosis occurred after 15 min of exposure to 1,900 and 1,000 ?atm CO(2), with full compensation by 2 and 4 h, respectively. 1,900-?atm exposure also resulted in significantly increased intracellular white muscle pH after 24 h. No effect of 1,900 ?atm was observed on branchial acid flux; however, exposure to hypercapnia and HCO(3)(-) free seawater compromised compensation. This suggests branchial HCO(3)(-) uptake rather than acid extrusion is part of the compensatory response to low-level hypercapnia. Exposure to 1,900 ?atm resulted in downregulation in branchial carbonic anhydrase and slc4a2 expression, as well as decreased Na(+)/K(+) ATPase activity after 24 h of exposure. Infusion of bovine carbonic anhydrase had no effect on blood acid-base status during 1,900 ?atm exposures, but eliminated the respiratory impacts of 1,000 ?atm CO(2). The results of the current study clearly show that predicted near-future CO(2) levels impact respiratory gas transport and acid-base balance. While the full physiological impacts of increased blood HCO(3)(-) are not known, it seems likely that chronically elevated blood HCO(3)(-) levels could compromise several physiological systems and furthermore may explain recent reports of increased otolith growth during exposure to elevated CO(2). PMID:22581071

Esbaugh, Andrew J; Heuer, Rachael; Grosell, Martin

2012-05-12

278

Impact of supplemental firing of tire-derived fuel (TDF) on mercury species and mercury capture with the advanced hybrid filter in a western subbituminous coal flue gas  

SciTech Connect

Pilot-scale experimental studies were carried out to evaluate the impacts of cofiring tire-derived fuel and a western subbituminous coal on mercury species in flue gas. Mercury samples were collected at the inlet and outlet of the Advanced Hybrid filter to determine mercury concentrations in the flue gas with and without TDF cofiring, respectively. Cofiring of TDF with a subbituminous coal had a significant effect on mercury speciation in the flue gas. With 100% coal firing, there was only 16.8% oxidized mercury in the flue gas compared to 47.7% when 5% TDF (mass basis) was fired and 84.8% when 10% TDF was cofired. The significantly enhanced mercury oxidation may be the result of additional homogeneous gas reactions between Hg{sup 0} and the reactive chlorine generated in the TDF-cofiring flue gas and the in situ improved reactivity of unburned carbon in ash by the reactive chlorine species. Although the cofiring of TDF demonstrated limited improvement on mercury-emission control with the Advanced Hybrid filter, it proved to be a very cost-effective mercury control approach for power plants equipped with wet or dry flue gas desulfurization (FGD) systems because of the enhanced mercury oxidation. 15 refs., 4 figs., 4 tabs.

Ye Zhuang; Stanley J. Miller [University of North Dakota, Grand Forks, ND (United States). Energy & Environmental Research Center

2006-05-15

279

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

280

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

281

Impact of operating conditions on performance of a novel gas double-dynamic solid-state fermentation bioreactor (GDSFB).  

PubMed

A self-designed novel solid-state fermentation (SSF) bioreactor named "gas double-dynamic solid-state fermentation bioreactor (GDSFB)" showed great success in processes for the production of several valuable products. For the present study, a simple GDSFB (2 L in volume) was designed to investigate the impact of exhaust time on SSF performance. Both air pressure and vent aperture significantly influenced the exhaust time. The production of cellulase by Penicillium decumbens JUA10 was studied in this bioreactor. When the vent aperture was maintained at 0.2 cm, the highest FPA activity of 17.2 IU/g dry solid-state medium was obtained at an air pressure of 0.2 MPa (gauge pressure). When the air pressure was maintained at 0.2 MPa, a vent aperture of 0.3 cm gave the highest FPA activity of 18.0 IU/g dry solid-state medium. Further analysis revealed that the exhaust time was a crucial indicator of good performance in GDSFB. PMID:23579630

Chen, Hongzhang; Li, Yanjun; Xu, Fujian

2013-04-12

282

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

283

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

284

Simultaneous multidetermination of residues of pesticides and polycyclic aromatic hydrocarbons in olive and olive-pomace oils by gas chromatography\\/tandem mass spectrometry  

Microsoft Academic Search

A multiresidue method for determining major pesticides and polycyclic aromatic hydrocarbons (PAHs) in olive oils in a single injection by use of gas chromatography\\/tandem mass spectrometry (GC–MS\\/MS) is proposed. Samples are previously extracted with an acetonitrile\\/n-hexane mixture and cleaned up by gel permeation chromatography. Electron ionization and chemical ionization allow pesticides and PAHs to be determined in a single analysis.

E. Ballesteros; A. García Sánchez; N. Ramos Martos

2006-01-01

285

78 FR 65698 - Notice of Availability of the Final Environmental Impact Statement for the Gas Hills In Situ...  

Federal Register 2010, 2011, 2012, 2013

...DATES: The Gas Hills ISR Uranium Project Final EIS will be available...82520; email: Gas_Hills_Uranium_EIS_WY@blm.gov. Persons...3809 regulations to construct uranium recovery facilities including...historically was disturbed by previous mining and exploration...

2013-11-01

286

75 FR 4427 - Pacific Gas & Electric Company; Notice of Intent To Prepare an Environmental Impact Statement and...  

Federal Register 2010, 2011, 2012, 2013

...NRC-2009-0552] Pacific Gas & Electric Company; Notice of...and 2 Pacific Gas & Electric Company (PG&E...20 years. Possible alternatives to the proposed action...action and reasonable alternative energy sources. The NRC is...

2010-01-27

287

Comparison of high resolution gas chromatography with electron impact and negative ion mass spectrometry detection for the determination of coplanar polychlorobiphenyl congeners in sewage sludges  

Microsoft Academic Search

The three most toxic coplanar PCB 77, 126 and 169 have been identified and quantified at ultra trace levels (0.02–4.8 ng\\/gdw) in swiss sewage sludge samples applying high resolution capillary gas chromatography (HRGC) and electron impact (EI) as well as negative ion chemical ionization (NCI) mass spectrometry (MS). NCI mass spectra have been dominated by the molecular ion as base

V. Raverdino; R. Holzer; J. D. Berset

1996-01-01

288

Evaluation of the impact of CO 2, co-contaminant gas, aqueous fluid and reservoir rock interactions on the geologic sequestration of CO 2  

Microsoft Academic Search

Lowering the costs of front–end processes (e.g., separation) in the geologic sequestration of CO2 can dramatically lower the overall costs. One possible approach is to sequester less-pure CO2 waste streams that are less expensive or require less energy to separate from flue gas or a coal gasification process, etc. The objective of this research is to evaluate the impacts of

Kevin G. Knauss; James W. Johnson; Carl I. Steefel

2005-01-01

289

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

290

A full fuel-cycle analysis of energy and emissions impacts of transportation fuels produced from natural gas  

Microsoft Academic Search

Because of its abundance and because it offers significant energy and evironmental advantages, natural gas has been promoted for use in motor vehicles. A number of transportation fuels are produced from natural gas; each is distinct in terms of upstream production activities and vehicle usage. In this study, the authors avaluate eight fuels produced from natural gas - compressed natural

M. Q. Wang; H. S. Huang

2000-01-01

291

77 FR 68814 - Notice of Availability of the Draft Environmental Impact Statement for the Gas Hills In Situ...  

Federal Register 2010, 2011, 2012, 2013

...Statement for the Gas Hills In Situ Recovery Uranium Project, Fremont and Natrona Counties...the Gas Hills In Situ Recovery (ISR) Uranium Project and by this notice [[Page 68815...written comments on the Gas Hills ISR Uranium Project draft EIS within 45 days...

2012-11-16

292

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

Microsoft Academic Search

Electric vehicles (EVs) can reduce greenhouse gas emissions, relative to emissions from gasoline-fueled vehicles. However, those studies have not considered all aspects that determine greenhouse gas emissions from both gasoline vehicles (GVs) and EVs. Aspects often overlooked include variations in vehicle trip characteristics, inclusion of all greenhouse gases, and vehicle total fuel cycle. In this paper, we estimate greenhouse gas

M. Q. Wang; W. W. Marr

1994-01-01

293

Technical and Nontechnical Issues Regarding Landfill Gas to Energy: What Is Their Impact on the U.S. Landfill Gas Industry.  

National Technical Information Service (NTIS)

The paper summarizes ongoing EPA research on landfill gas (LFG) utilization. Research was conducted to identify technical issues and solutions through interviews conducted with industry experts in the U.S., Europe, and Australia. The paper provides summar...

S. A. Thorneloe J. G. Pacey M. Doorn

1995-01-01

294

A study of the gas-phase ozonolysis of terpenes: the impact of radicals formed during the reaction  

NASA Astrophysics Data System (ADS)

The gas-phase ozonolysis of ?-pinene, ?3-carene and limonene was investigated at ppb levels and the impact of the ozone, relative air humidity (RH), and time was studied using experimental design. The amounts of terpene reacted varied in the different settings and were as high as 8.1% for ?-pinene, 10.9% for ?3-carene and 23.4% for limonene. The designs were able to describe almost all the variation in the experimental data and were also successful in predicting omitted values. The results described the effects of time and ozone and also showed that RH did not have a statistically significant effect on the ozonolysis. The results also showed that all three terpenes were affected by an additional oxidation of OH radicals and/or other reactive species. The results from the designs states that this additional oxidation was responsible for 40% of the total amount of ?-pinene reacted, 33% of the total amount of ?3-carene reacted and 41% of the total amount of limonene reacted at the settings 20 ppb terpene, 75 ppb ozone, 20% RH and a reaction time of 213 s. Additional experiments with 2-butanol as OH radical scavenger showed that the reaction with OH radicals was responsible for 37% of the total ?-pinene reacted and 39% of the total ?3-carene reacted at the same settings. The scavenger experiments also showed that there were no significant amounts of OH radicals formed during the ozonolysis of limonene. The results from the designs were also compared to a mathematical model in order to evaluate further the data.

Fick, Jerker; Pommer, Linda; Andersson, Barbro; Nilsson, Calle

295

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

296

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

297

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

298

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

299

Impacts of plug-in hybrid vehicles and combined heat and power technologies on electric and gas distribution network losses  

Microsoft Academic Search

Distribution network operators (DNOs) require strategies that can offset the tradeoffs new embedded technologies have on their assets. This paper employs modelling to show that through control device manipulation, gas and electric (G&E) network operators can influence savings in energy losses under the presence of plug-in hybrid vehicles (PHEVs) and combined heat and power technologies (CHPs). An integrated gas and

Salvador Acha; Tim C. Green; Nilay Shah

2009-01-01

300

Methane Sampling Technique and the Measurement of Plunge Pool Impact on Gas Transfer Rates at Low-Head Hydraulic Structures.  

National Technical Information Service (NTIS)

In situ dissolved methane gas was used as a tracer for estimating the gas transfer rates of flow over low-head hydraulic structures. The methane measurement provided a means to assess the effects of the plunging flow in the structure stilling basin. Simul...

D. E. Hibbs J. S. Gulliver J. P. McDonald

1995-01-01

301

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

Federal Register 2010, 2011, 2012, 2013

...THE INTERIOR National Park Service [NPS-SERO-BISO-0412-10010...for the Oil and Gas Management Plan at Big South Fork National River and Recreation Area and Obed Wild and...Kentucky AGENCY: National Park Service, Department...for the Oil and Gas Management Plan (Plan) for...

2012-07-20

302

Mach one impact test apparatus utilizing an 18.4-mm-bore gas gun with a novel decelerating device.  

PubMed

The design and operation of a helium-gas-driven gun capable of operation to Mach one is described in this report. The gun utilizes a unique tapered-tube decelerator that captures the sabot and prevents gas discharge from the muzzle. This feature makes it possible to operate the gun in a normal laboratory environment without excessive safety precautions. PMID:18699612

Coppa, A P; Selden, G F; Mehan, R L

1979-07-01

303

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

304

Liquid-liquid extraction followed by solid-phase extraction for the determination of lipophilic pesticides in beeswax by gas chromatography-electron-capture detection and matrix-matched calibration.  

PubMed

Analytical methods for the simultaneous analysis of lindane, chlorpyriphos, z-chlorfenvinphos, endosulfan A and B, 4,4'-DDE, 4,4'-TDE, acrinathrine, bromopropylate, tetradifon, coumaphos and fluvalinate in pure beeswax samples are studied. For the analysis of bleached beeswaxes, a liquid-liquid extraction with acetonitrile followed by a clean-up on polymeric cartridges is the best option in terms of recovery and precision. However, some interferences that hinder the identification and quantification of important varroacides are found when non-bleached beeswaxes are analyzed. The analysis of all compounds in the latter samples require a clean-up by coupling an ODS cartridge before the polymeric cartridge. Considerations about the influence of the matrix in the quantitative analysis by a classical external standard calibration are also made and the use of a matrix-matched calibration is advised. Recoveries resulted to be about 100% with coefficients of variation between 10% and 20% (n = 5) for concentrations of 0.5 and 5 mg/kg. PMID:15453423

Jiménez, J J; Bernal, J L; del Nozal, Ma J; Alonso, C

2004-09-01

305

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

306

Gas chromatography/mass spectrometric analysis of N,N-dialkylaminoethyl-2-chlorides and trimethylsilyl derivatives of N,N-dialkylaminoethan-2-ols for verification of the Chemical Weapons Convention.  

PubMed

Gas chromatography/electron ionization mass spectrometry (GC/EI-MS) of N,N-dialkylaminoethyl-2-chlorides (DAAECls) and trimethylsilyl (TMS) derivatives of N,N-dialkylaminoethan-2-ols (DAAEAs) has been carried out. GC/EI-MS data of these compounds are of importance for verification of the Chemical Weapons Convention (CWC). Based on these EI mass spectra, generalized fragmentation routes are proposed that rationalize most of the characteristic ions. PMID:16773673

Gupta, Arvinda K; Pardasani, Deepak; Kanaujia, Pankaj K; Tak, Vijay; Dubey, Devendra K

2006-01-01

307

Environmental impact and regulatory concerns for the protection of a freshwater aquifer impacted by a gas well blowout in northwest Louisiana  

Microsoft Academic Search

The Louisiana Department of Environmental Quality, Ground Water Protection Division (GWPD) is responsible for oversight of the investigation and remediation of unpermitted releases to the waters of the State. In March, 1994, a Sligo Field gas well blowout caused artificial artesian conditions in the shallow Wilcox aquifer resulting in flowing water wells near the drilling location. The eruption of sand

W. H. Schramm; D. T. McKenzie; M. S. Kline

1996-01-01

308

Life cycle environmental impact of a thermosyphonic domestic solar hot water system in comparison with electrical and gas water heating  

Microsoft Academic Search

A methodology for the environmental impact evaluation over the life span of a Domestic Solar Hot Water System (DSHWS) is presented. The results are compared to the environmental consequences of the conventional energy form substituted and the total environmental gain is calculated. For the purposes of this analysis, the “Eco-indicator ’99” Life Cycle Impact Assessment methodology was adopted and the

G. Tsilingiridis; G. Martinopoulos; N. Kyriakis

2004-01-01

309

Pacific Gas and Electric Company. Financial impacts on utilities of load shape changes project. Stage II technical report  

Microsoft Academic Search

The goal of this LBL project is to develop tools and procedures that measure the financial impacts of load shape changes to utility stockholders. In this application, the financial impacts of exogenous policies that raise the efficiencies of residential appliances are studied. The analysis is based on detailed forecasts of energy use by computer simulation models developed at LBL. These

J. H. Eto; J. McMahon; P. Chan

1984-01-01

310

Economic and Greenhouse Gas Emission Impacts of Electric Energy Efficiency Investments: A Wisconsin Case Study. Rebuild America Guide Series.  

National Technical Information Service (NTIS)

The purpose of this report is to examine the macroeconomic impacts of consumer and business investments in end use efficiency and end use fuel switching measures that reduce electricity use in Wisconsin. It does not analyze the economic impacts of investm...

S. Clemmer S. Olson M. Arny

2001-01-01

311

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

312

Polychaete/amphipod ratio as an indicator of environmental impact related to offshore oil and gas production along the Norwegian continental shelf.  

PubMed

Benthic faunal data is regularly collected worldwide to assess the ecological quality of marine environments. Recently, there has been renewed interest in developing biological indices able to identify environmental status and potential anthropogenic impacts. In this paper we evaluate the performance of a general polychaete/amphipod ratio along the Norwegian continental shelf as an environmental indicator for offshore oil and gas impacts. Two main trends are apparent: first, a contamination gradient is discernible from where production takes place compared to stations 10,000 m away. Second, the quality of the marine environment has improved over time. These results are consistent with monitoring reports employing a combination of uni- and multi-variate statistics. Thus, we consider this ratio as a relatively simple, useful and potentially cost-effective complement to other more demanding assessment techniques. Because of its strong theoretical basis, it may also be useful for detecting ecological change as a result of other activities. PMID:22000480

Andrade, Hector; Renaud, Paul E

2011-10-13

313

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

SciTech Connect

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.

Kawai, Nobuaki; Tsurui, Kenji; Hasegawa, Sunao; Sato, Eiichi [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan)

2010-11-15

314

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

315

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

NASA Astrophysics Data System (ADS)

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.

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

2010-11-01

316

Final Environmental Impact Statement, Proposed Outer Continental Shelf Oil and Gas Lease Sale, North Aleutian Basin, Sale 92. Volume 2.  

National Technical Information Service (NTIS)

The EIS analyzes a proposed oil and gas lease sale in the North Aleutian Basin, alternatives to the proposal, major issues determined through the scoping process, and potential mitigating measures. The report, volume II contains the review and analysis of...

T. H. Boyd G. Yankus

1985-01-01

317

Environmental Impact Assessment: Chemical Explosive Fracturing Project, Petroleum Technology Corporation/Columbia Gas Transmission Corporation, Lincoln County, West Virginia.  

National Technical Information Service (NTIS)

This review of the plans for the chemical explosive fracturing of the Devonian shales of Lincoln County, W. Va., for natural gas stimulation includes an assessment of the environmental effects. Alternatives, mitigating factors, cost benefit analysis, pote...

K. A. Tonnessen

1977-01-01

318

Impact of seasonal temperature and pressure changes on methane gas production, dissolution, and transport in unfractured sediments  

NASA Astrophysics Data System (ADS)

A one-dimensional reaction-transport model is used to investigate the dynamics of methane gas in coastal sediments in response to intra-annual variations in temperature and pressure. The model is applied to data from two shallow water sites in Eckernförde Bay (Germany) characterized by low and high rates of upward fluid advection. At both sites, organic matter is buried below the sulfate-reducing zone to the methanogenic zone at sufficiently high rates to allow supersaturation of the pore water with dissolved methane and to form a free methane gas phase. The methane solubility concentration varies by similar magnitudes at both study sites in response to bottom water temperature changes and leads to pronounced peaks in the gas volume fraction in autumn when the methanic zone temperature is at a maximum. Yearly hydrostatic pressure variations have comparatively negligible effects on methane solubility. Field data suggest that no free gas escapes to the water column at any time of the year. Although the existence of gas migration cannot be substantiated by direct observation, a speculative mechanism for slow moving gas is proposed here. The model results reveal that free gas migrating upward into the undersaturated pore water will completely dissolve and subsequently be consumed above the free gas depth (FGD) by anaerobic oxidation of methane (AOM). This microbially mediated process maintains methane undersaturation above the FGD. Although the complexities introduced by seasonal changes in temperature lead to different seasonal trends for the depth-integrated AOM rates and the FGD, both sites adhere to previously developed prognostic indicators for methane fluxes based on the FGD.

Mogollón, J. M.; Dale, A. W.; L'Heureux, I.; Regnier, P.

2011-09-01

319

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

Microsoft Academic Search

Past studies have shown that use of electric vehicles (EVs) can reduce greenhouse gas emissions, relative to emissions from gasoline-fueled internal-combustion-engine vehicles. However, those studies have not considered all aspects that determine greenhouse gas emissions from both gasoline vehicles (GVs) and EVs. Aspects often overlooked include variations in vehicle trip characteristics, inclusion of all greenhouse gases, and vehicle total fuel

M. Q. Wang; W. W. Marr

1994-01-01

320

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

321

78 FR 42516 - Iroquois Gas Transmission System, L.P.; Notice of Intent To Prepare an Environmental Impact...  

Federal Register 2010, 2011, 2012, 2013

...Environmental Impact Statement for the Proposed Wright Interconnect Project and Request for Comments...making modifications at Iroquois' existing Wright Compressor Station in Schoharie County...These modifications, known as the Wright Interconnect Project (WIP), would...

2013-07-16

322

Using a two-layered sphere model to investigate the impact of gas vacuoles on the inherent optical properties of M. aeruginosa  

NASA Astrophysics Data System (ADS)

A two-layered sphere model is used to investigate the impact of gas vacuoles on the inherent optical properties (IOPs) of the cyanophyte Microcystis aeruginosa. Enclosing a vacuole-like particle within a chromatoplasm shell layer significantly altered spectral scattering and increased backscattering. The two-layered sphere model reproduced features in the spectral attenuation and volume scattering function (VSF) that have previously been attributed to gas vacuoles. This suggests the model is good at least as a first approximation for investigating how gas vacuoles alter the IOPs. The central value of the real refractive index, 1+ ?, for the shell layer was determined using a radiative transfer model and measured remote sensing reflectance, Rrs, and IOP data. For a cell with 50% vacuole volume, the mean 1+ ? value for the shell layer was 1.12. The corresponding chl a specific phytoplankton backscattering coefficient, bb?*, ranged between 3.9 × 10-3 and 7.2 × 10-3 m2 mg-1 at 510 nm. This agrees closely with in situ particulate backscattering measurements and values reported elsewhere. Rrs simulated for a population of vacuolate cells was greatly enlarged relative to a homogeneous population. Empirical algorithms based on Rrs were derived for estimating chl a in eutrophic/hypertrophic waters dominated by M. aeruginosa. The study confirms that gas vacuoles cause significant increase in backscattering and are responsible for the high Rrs values observed in buoyant cyanobacterial blooms. Gas vacuoles are therefore one of the most important bio-optical substructures influencing the IOPs in phytoplankton.

Matthews, M. W.; Bernard, S.

2013-06-01

323

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

324

Photolytic clean-up of biological samples for gas chromatographic analysis of chlorinated paraffins.  

PubMed

A method based on gas chromatography electron capture detection (GC-ECD) for the analysis of chlorinated paraffins (CPs) in biological samples has been investigated. The method includes photolytic destruction of halogenated aromatic compounds, such as PCBs, to eliminate some of the interferences in the analysis of CPs in environmental samples. Gel permeation chromatography was used to isolate CPs from the interfering components of Toxaphene and chlordane after the photolysis. GC-ECD gave a detection limit of 20 ng CPs/g fresh muscle tissue. The recovery of CPs from a spiked moose liver sample was estimated to 94%. PMID:14664836

Fridén, Ulrika; Jansson, Bo; Parlar, Harun

2004-02-01

325

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

SciTech Connect

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.

Schachter, L.; Dobrescu, S. [National Institute for Physics and Nuclear Engineering, Bucharest (Romania); Stiebing, K. E. [Institut fuer Kernphysik der J. W. Goethe-Universitaet, Frankfurt/Main (Germany)

2012-02-15

326

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

NASA Astrophysics Data System (ADS)

Hypervelocity impact experiments that reproduce on-orbit collisions between micrometeoroids or orbital debris and space structures are commonly performed by means of propellant-driven two-stage light-gas guns. Such devices accelerate projectiles using the thrust of a light propellant gas that is compressed to high pressure and temperature by a piston running in a pump tube. Though these guns have the unique capability of accelerating particles up to 9 km/s, many components of the gun must be checked and/or substituted after each shot making test sessions long and expensive. In order to have a lot of and many different types of hypervelocity impact data, the Center of Studies and activities for Space CISAS ``G. Colombo'' of Padua University developed a high-shot-frequency two-stage light-gas gun that can increase the shot repetition rate of standard facilities by a factor of 5 or more and at the same time reduce the shot cost by a factor of 2 or more. This is made possible through the use of special mechanical and diagnostic solutions that were designed to operate the gun for more than 50 shots in sequence without having to carry out maintenance operations. This article presents the design and operation of the CISAS two-stage light-gas gun damping system, which is one of the subsystems that makes it possible to achieve high-shot frequency. The damping system is in charge of controlling the piston oscillations in the pump tube, making it possible for the piston to withstand more than 100 shots without any damage. In particular, the damping system avoids piston strikes onto the gun head at the end of each compression stroke and allows the piston to be positioned at the base of the pump tube after each shot. The sensitivity of the piston oscillations to the damping operations and main subsystem design parameters were identified using numerical simulations, carried out according to a model that describes every working phase of the gun. Moreover, in this paper, the technical solutions for the damping system implementation are presented and the numerical predictions are compared with experimental results. For the CISAS high-shot-frequency gas gun, an efficient damping system proved to be a fundamental requirement to reliably accelerate 100 mg projectiles above 5 km/s and 70 mg projectiles at 5.5 km/s with a shot frequency of 10 shots per day at least, including the time needed for replacing the target and pumping down the target vacuum chamber.

Pavarin, D.; Francesconi, A.; Angrilli, F.

2004-01-01

327

Impact of using high-density polyethylene geomembrane layer as landfill intermediate cover on landfill gas extraction  

Microsoft Academic Search

Clay is widely used as a traditional cover material for landfills. As clay becomes increasingly costly and scarce, and it also reduces the storage capacity of landfills, alternative materials with low hydraulic conductivity are employed. In developing countries such as China, landfill gas (LFG) is usually extracted for utilization during filling stage, therefore, the intermediate covering system is an important

Zezhi Chen; Huijuan Gong; Mengqun Zhang; Weili Wu; Yu Liu; Jin Feng

2011-01-01

328

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

329

NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES  

Microsoft Academic Search

The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens,

Brett C. Singer; Michael G. Apte; Douglas R. Black; Toshifumi Hotchi; Donald Lucas; Melissa M. Lunden; Anna G. Mirer; Michael Spears; Douglas P. Sullivan

2009-01-01

330

Strategies for carbon dioxide emissions reductions: Residential natural gas efficiency, economic, and ancillary health impacts in Maryland  

Microsoft Academic Search

As part of its commitments to the Regional Greenhouse Gas Initiative (RGGI), the State of Maryland, USA, auctions emission permits to electric utilities, creating revenue that can be used to benefit consumers and the environment. This paper explores the CO2 emissions reductions that may be possible by allocating some of that revenue to foster efficiency improvements in the residential sector’s

Matthias Ruth; Andrew Blohm; Joanna Mauer; Steven A. Gabriel; Vijay G. Kesana; Yihsu Chen; Benjamin F. Hobbs; Daraius Irani

2010-01-01

331

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

Microsoft Academic Search

Three federal Outer Continental Shelf oil and gas lease sales have been held in the Bering Sea Subregion. Lease Sale 57, Norton Basin, was held on March 15, 1983. Bids were received on 64 of the 418 blocks offered, resulting in the Department of the Interior issuing leases for 59 blocks. Lease Sale 70, St. George Basin, held on April

Deis

1984-01-01

332

IMPACT OF GROWING ENVIRONMENT ON CHICKASAW BLACKBERRY (RUBUS L.) AROMA EVALUATED BY GAS CHROMATOGRAPHY OLFACTOMETRY DILUTION ANALYSIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The aroma extract of Chickasaw blackberry ( RubusL.) was separated with silica gel normal phase chromatography into six fractions. Gas chromatography-olfactometry (GCO) was performed on each fraction to identify aroma active compounds. Aroma extraction dilution analysis (AEDA) was employed to charac...

333

The Impact of Azimuthal Anisotropy on Seismic AVO and Petrophysical Response in a Fractured Wabamun Gas Reservoir  

Microsoft Academic Search

The evaluation of many fractured carbonate reservoirs would benefit greatly from a reliable method of determining fracture density and orientation from seismic data. Although the most technically exhaustive approach would likely involve multi-component analysis, the potential of azimuthal information contained within conventional AVO must not be overlooked. The focus of this study is a prolific gas well drilled on a

Brian Rex; Bill Goodway; Cathy Martin; Gordon Uswak

334

Impact of alternative n fertilizer sources on cotton yield and greenhouse gas emissions in a coastal plain soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Interest in the use of alternative fertilizer sources have increased in recent years. This is partially attributed to the belief that the new enhanced-efficiency N fertilizer sources can potentially increase crop yield, while at the same time decreasing greenhouse gas emissions. Thus, a field stud...

335

Environmental impact assessment: chemical explosive fracturing project, Petroleum Technology Corporation\\/Columbia Gas Transmission Corporation, Lincoln County, West Virginia  

Microsoft Academic Search

This review of the plans for the chemical explosive fracturing of the Devonian shales of Lincoln County, W. Va., for natural gas stimulation includes an assessment of the environmental effects. Alternatives, mitigating factors, cost benefit analysis, potential conflicts with other plans and programs, and relation of short-term use to long-term productivity are covered briefly. It is concluded that the proposed

Tonnessen

1977-01-01

336

Environmental impact assessment: chemical explosive fracturing project, Petroleum Technology Corporation\\/Columbia Gas Transmission Corporation, Lincoln County, West Virginia  

Microsoft Academic Search

This review of the plans for the chemical explosive fracturing of the Devonian shales of Lincoln County, West Virginia, for natural gas stimulation includes an assessment of the environmental effects. Alternatives, mitigating factors, cost benefit analysis, potential conflicts with other plans and programs, and relation of short-term use to long-term productivity are covered briefly. It is concluded that the proposed

Tonnessen

1977-01-01

337

The impact of prolonged flood-irrigation on leaf gas exchange in mature pecans in an orchard setting  

Microsoft Academic Search

Woody perennials subjected to root oxygen-stress often respond with varying levels of reduced assimilation and leaf gas exchange. Yet in most of these studies, seedlings grown in pots were subjected to experimental conditions that rarely exist in nature for mature trees. To determine if flooding mature orchard-grown pecan (Carya illinoiensis (Wangh) K. Koch) results in a similar depressed photosynthetic rate

J. C. Kallestad; T. W. Sammis; J. G. Mexal; V. Gutschick

338

Biodegradation of gas-phase styrene using the fungus Sporothrix variecibatus: impact of pollutant load and transient operation.  

PubMed

Biofiltration of gas-phase styrene was studied using a newly isolated fungus Sporothrix variecibatus, in a perlite biofilter, at inlet concentrations and gas-flow rates ranging from 0.13 to 14 g m(-3) and 0.075 to 0.34 m(3) h(-1), respectively, corresponding to empty bed residence times (EBRT) ranging between 91 and 20s. Styrene loading rates were varied between 50 and 845 g m(-3) h(-1)and a maximum elimination capacity of 336 g m(-3) h(-1) was attained with nearly 65% styrene removal. On the other hand, the critical inlet loads to achieve more than 90% removal were 301, 240 and 92 g m(-3) h(-1) for EBRT of 91, 40, and 20s, respectively. In order to test the stability and shock bearing capacity of the fungal biofilter, short-term tests were conducted by suddenly increasing the gas-phase styrene concentration, while maintaining the gas-flow rate constant. The response, a restoration in the removal performance to previous high values, after subjecting the biofilter to shock loads proves the resilient nature of the attached Sporothrix sp. and its suitability for biofiltration under non-steady state conditions. PMID:20149411

Rene, Eldon R; Veiga, María C; Kennes, Christian

2010-02-09

339

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

340

IMPACTS OF GREENHOUSE GAS AND PARTICULATE EMISSIONS FROM WOODFUEL PRODUCTION AND END-USE IN SUB-SAHARAN AFRICA  

Microsoft Academic Search

Household energy in sub-Saharan Africa is largely derived from woodfuels burned in simple stoves with poor combustion characteristics. These devices emit products of incomplete combustion (PICs) that both damage human health and negatively impact the atmospheric radiation budget. We use empirical studies and published emission factors to estimate the pollution associated with production, distribution and end-use of common household fuels

Robert Bailis; David Pennise; Majid Ezzati; Daniel M. Kammen; Evans Kituyi

341

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

Microsoft Academic Search

A potential abatement to increasing levels of carbon dioxide (CO2) 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

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

2009-01-01

342

Pacific summary report. Outer Continental Shelf oil and gas activities in the Pacific and their onshore impacts  

Microsoft Academic Search

The Pacific Outer Continental Shelf (OCS) is an established hydrocarbon-producing region. Oil and gas have been produced from the Santa Barbara Channel since 1896. About 75,300 barrels of oil are produced from the California Federal OCS each day as of March 1982, and leases on State tidelands produce about 40,000 barrels of oil per day. This highly developed area is,

A. Stadnychenko; C. McCord

1982-01-01

343

Trade-linked Canada–United States household environmental impact analysis of energy use and greenhouse gas emissions  

Microsoft Academic Search

We compare energy use and greenhouse gas (GHG) emissions associated with total household expenditures and activities in Canada and US in 1997, the first detailed estimate of environmental burdens for Canadian households. We estimate direct burdens from published government data and indirect burdens using an industry-by-commodity, bi-national economic input–output life cycle assessment model developed in this study. Comparing 30 expenditure

Thomas M. Ferguson; Heather L. MacLean

2011-01-01

344

Impact of fly ash content and fly ash transportation distance on embodied greenhouse gas emissions and water consumption in concrete  

Microsoft Academic Search

Background, aim and scope  Fly ash, a by-product of coal-fired power stations, is substituted for Portland cement to improve the properties of concrete\\u000a and reduce the embodied greenhouse gas (GHG) emissions. Much of the world’s fly ash is currently disposed of as a waste product.\\u000a While replacing some Portland cement with fly ash can reduce production costs and the embodied emissions

Kate R. O’Brien; Julien Ménaché; Liza M. O’Moore

2009-01-01

345

Impact of Oxidation Catalysts on Exhaust NO2\\/NOx Ratio from Lean-Burn Natural Gas Engines  

Microsoft Academic Search

Oxides of nitrogen (NOx) emitted from internal combustion engines are composed primarily of nitric oxide (NO) and nitrogen dioxide (NO2). Exhaust from most combustion sources contains NOx composed primarily of NO. There are two important scenarios specific to lean-burn natural gas engines in which the NO2\\/NOx ratio can be significant: (1) when the engine is operated at ultralean conditions and

Daniel B. Olsen; Morgan Kohls; Gregg Arney; Krzysztof Pikon´; Krzysztof Gaska; Lingjuan Wang; Edgar Oviedo-Rondon; John Small; Zifei Liu; Brian Sheldon; Gerald Havenstein; C. Williams; Di Tian; Daniel Cohan; Sergey Napelenok; Michelle Bergin; Yongtao Hu; Michael Chang; Armistead Russell; Ye Xu; Guohe Huang; Xiaosheng Qin; Kuo-Pin Yu; Grace Lee; Guo-Hao Huang; Prabhakar Sharma; Tjalfe Poulsen; William Vizuete; Leiran Biton; Harvey Jeffries; Evan Couzo; Yi-Chi Chien; Chenju Liang; Shou-Heng Liu; Shu-Hua Yang; Maciej Kryza; Malgorzata Werner; Marek Blas; Anthony Dore; Mieczyslaw Sobik; Kaushlendra Singh; L. Risse; K. C. Das; John Worley; Sidney Thompson; Bryan Comer; James Corbett; J. Hawker; Karl Korfmacher; Earl Lee; Chris Prokop; James Winebrake

2010-01-01

346

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

347

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

NASA Astrophysics Data System (ADS)

The legacy of historical and the long-term impacts of 21st century greenhouse gas emissions on climate, ocean acidification, and carbon-climate feedbacks are investigated with a coupled carbon cycle-climate model. Emission commitment scenarios with zero emissions after year 2100 and 21st century emissions of 1,800, 900, and 0 gigatons of carbon are run up to year 2500. The reversibility and irreversibility of impacts is quantified by comparing anthropogenically-forced regional changes with internal, unforced climate variability. We show that the influence of historical emissions and of non-CO2 agents is largely reversible on the regional scale. Forced changes in surface temperature and precipitation become smaller than internal variability for most land and ocean grid cells in the absence of future carbon emissions. In contrast, continued carbon emissions over the 21st century cause irreversible climate change on centennial to millennial timescales in most regions and impacts related to ocean acidification and sea level rise continue to aggravate for centuries even if emissions are stopped in year 2100. Undersaturation of the Arctic surface ocean with respect to aragonite, a mineral form of calcium carbonate secreted by marine organisms, is imminent and remains widespread. The volume of supersaturated water providing habitat to calcifying organisms is reduced from preindustrial 40 to 25% in 2100 and to 10% in 2300 for the high emission case. We conclude that emission trading schemes, related to the Kyoto Process,should not permit trading between emissions of relatively short-lived agents and CO2 given the irreversible impacts of anthropogenic carbon emissions.

Froelicher, T. L.; Joos, F.

2010-12-01

348

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

NASA Astrophysics Data System (ADS)

The legacy of historical and the long-term impacts of 21st century greenhouse gas emissions on climate, ocean acidification, and carbon-climate feedbacks are investigated with a coupled carbon cycle-climate model. Emission commitment scenarios with zero emissions after year 2100 and 21st century emissions of 1,800, 900, and 0 gigatons of carbon are run up to year 2500. The reversibility and irreversibility of impacts is quantified by comparing anthropogenically-forced regional changes with internal, unforced climate variability. We show that the influence of historical emissions and of non-CO2 agents is largely reversible on the regional scale. Forced changes in surface temperature and precipitation become smaller than internal variability for most land and ocean grid cells in the absence of future carbon emissions. In contrast, continued carbon emissions over the 21st century cause irreversible climate change on centennial to millennial timescales in most regions and impacts related to ocean acidification and sea level rise continue to aggravate for centuries even if emissions are stopped in year 2100. Undersaturation of the Arctic surface ocean with respect to aragonite, a mineral form of calcium carbonate secreted by marine organisms, is imminent and remains widespread. The volume of supersaturated water providing habitat to calcifying organisms is reduced from preindustrial 40 to 25% in 2100 and to 10% in 2300 for the high emission case. We conclude that emission trading schemes, related to the Kyoto Process, should not permit trading between emissions of relatively short-lived agents and CO2 given the irreversible impacts of anthropogenic carbon emissions.

Frölicher, Thomas L.; Joos, Fortunat

2010-12-01

349

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

350

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

351

Differential impact of immediate total deregulation of wellhead prices of natural gas on minority and low-income homeowners: a general review and a case study in the Washington, DC area  

SciTech Connect

In this study, the authors evaluate the impact of total deregulation of wellhead prices of natural gas on various strata of the residential consuming population, and compare it to the baseline impact of a continuation of the Natural Gas Policy Act of 1978. They found that minority and poverty homeowners will suffer greater relative welfare losses than their white and non-poverty counterparts. They developed quantitative estimates of the extent of these differentials, and offered some policy proposals suggested by these findings. 54 refs., 8 figs., 68 tabs.

Green, R.D.; Gilbert, H.R.

1983-01-01

352

Perfluoroalkyl ketones: novel derivatization products for the sensitive determination of fatty acids by gas chromatography/mass spectrometry in electron impact and negative chemical ionization modes.  

PubMed

Analytically useful pentafluoro ketone derivatives of fatty acids are described. The gas chromatographic/mass spectrometric characteristics of these new derivatives are compared with those of methyl, trimethylsilyl and pentafluorobenzyl esters. Pentafluoro ketones exhibit excellent chromatographic properties and significantly shorter chromatographic retention times than these other esters. The electron impact mass spectra of these new compounds show informative acylium ions, whose intensity decreases with the degree of unsaturation of the parent fatty acid. The formation of strong and informative fragment ions in negative chemical ionization (CH(4)) mass spectra of pentafluoro ketone derivatives allows the detection and the characterization (length of the chain and number of double bonds) of fatty acids at trace levels (femtomole), even in the case of polyunsaturated compounds. The scope and limitations of this new derivatization technique are also discussed. PMID:10844732

Aubert, C; Rontani, J F

2000-01-01

353

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

354

The most luminous H2 emitters in the Universe? AGN Feedback, Warm Molecular Gas, and the Impact of the Radio Jets in High-z Radio Galaxies  

NASA Astrophysics Data System (ADS)

Strong negative feedback from supermassive black holes has been proposed to solve one of the outstanding problems in galaxy evolution models -- the 'hierarchy problem' where the most massive galaxies formed early and rapidly. We propose to test this hypothesis through observations of 5 powerful radio galaxies at z~2 with IRS in the LH and LL mode to study the properties of the warm molecular emission in these galaxies. If this hypothesis is correct, and these galaxies are driving strong outflows, outflows powerful and robust enough to solve this problem, we should observe broad, luminous H_2 emission lines in all sources, with widths of 1000 km/s or more, similar to what is observed in the rest-frame optical emission lines and luminositiies corresponding to relatively high temperatures and large H_2 mass, comparable or greater than the H_2 masses inferred from CO observations. This will be the first detection of H_2 at high redshift in sources, which have all the properties of being among the most luminous H_2 emitters in the universe. All of these targets are well-studied. They have near-infrared integral field spectroscopy revealing large velocity shears and dispersions, large enough so that the optical line emitting gas will escape even the most massive galaxy halos, large molecular masses from CO observations (few x 1e10 solar masses), and high resolution multi-frequency radio maps to infer both jet power and radio morphology to gauge the impact of relativistic electrons on the ambient ISM of the host galaxy. The missing component in all these studies is of course the impact the radio jet on the molecular gas, where most of the mass in these objects may in fact lie. As such, these observations are crucial to substantially increase our rudimentary understanding of the outflows driven by powerful AGN, and their yet largely unknown influence on the properties of the most massive galaxies.

Nesvadba, Nicole; Appleton, Philip; Armus, Lee; Boulanger, Francois; Guillard, Pierre; Lagache, Guilaine; Lehnert, Matthew; Ogle, Patrick; Omont, Alain

2008-03-01

355

Impact of the BEA zeolite morphology on isobutane adsorption followed by Reversed-Flow Inverse Gas Chromatography.  

PubMed

The mass transfer phenomena of isobutane (i-C4) were investigated at 343K on three protonic BEA zeolites. Defined by their crystallites sizes and degrees of aggregation, these samples were characterized by Reversed-Flow Inverse Gas Chromatography (RF-GC). This simple technique, used in conjunction with numerical computation, allowed the determination of physicochemical quantities like local monolayer capacities, probability density functions and diffusion coefficients in a time-resolved way. This study enabled to conclude that the effective diffusion coefficient was affected by the size of the zeolite agglomerate whereas the surface diffusion depended on the zeolite crystallite size. PMID:22964049

Batalha, N; Soualah, A; Pinard, L; Pouilloux, Y; Lemos, F; Belin, T

2012-08-30

356

Impact of Shallow Convection on the Gas Hydrate Reservoir in the Gulf of Mexico Salt Tectonics Province  

NASA Astrophysics Data System (ADS)

Previous modeling studies have suggested that subseafloor hydrogeology in the northern Gulf of Mexico could be strongly affected by the presence of salt domes, but these efforts were at the time limited to formulations that decoupled thermal and chemical buoyancy. The earlier studies concluded that downwelling associated with the negative buoyancy of dense briny fluids dominated upwelling associated with positive thermal buoyancy near salt domes. In this study, we use modern hydrologic models that fully couple thermal and chemical effects to re-examine this problem with particular focus on Gulf of Mexico gas hydrate reservoirs. We first demonstrate that even slight variations in seafloor bathymetry lead to the onset of shallow convection in marine sediments and that the existence of such convective patterns is not dependent on the presence of salt or the geometry of the salt body. Bathymetric highs are generally the loci of upwelling, while downwelling is concentrated in bathymetric lows. The length scale of the convective cells depends on the wavelength of seafloor topography but is generally hundreds to less than 2000 m, consistent with observational evidence one of us has earlier reported for the Mississippi Canyon and Garden Banks gas hydrate areas. The model calculations are consistent with the observed pattern of chloride, sulfate, and thermal anomalies, suggesting that the modeling results can be used to estimate the variation in the depth of hydrate stability and hydrate occurrence in these highly dynamic systems. Our simulations of the transient evolution of convective regimes near salt domes show that the near-surface, thermally-driven system eventually separates from the deeper, chemically-driven system dominated by stable, dense brines. In this scenario, the gas hydrate stability zone will change as a function of time due to the changing hydraulic regime in the sediments. Superposed on such hydraulic effects on the hydrate stability zone would be the influence of better understood processes such as sedimentation or erosion of the sedimentary column. Finally, we explicitly consider the role of faults in focusing fluids in these systems and conclude that faults can radically perturb the chemical and thermal conditions near salt domes to the point of entirely dominating the flow field and thus the gas hydrate stability field. The results are applied to zones of focused flux, such as the mud mounds in the Garden Banks and Mississippi Canyon areas and the seeps at Bush Hill, and to a zone of 'diffuse advective flux' characterized by a regional BSR at Keathley Canyon.

Wilson, A.; Ruppel, C.

2005-12-01

357

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

358

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

2013-09-05

359

Variation of the gas and radiation content in the sub-Keplerian accretion disk around black holes and its impact to the solutions  

NASA Astrophysics Data System (ADS)

We investigate the variation of the gas and the radiation pressure in accretion disks during the infall of matter to the black hole and its effect to the flow. While the flow far away from the black hole might be non-relativistic, in the vicinity of the black hole it is expected to be relativistic behaving more like radiation. Therefore, the ratio of gas pressure to total pressure (?) and the underlying polytropic index (?) should not be constant throughout the flow. We obtain that accretion flows exhibit significant variation of ? and then ?, which affects solutions described in the standard literature based on constant ?. Certain solutions for a particular set of initial parameters with a constant ? do not exist when the variation of ? is incorporated appropriately. We model the viscous sub-Keplerian accretion disk with a nonzero component of advection and pressure gradient around black holes by preserving the conservations of mass, momentum, energy, supplemented by the evolution of ?. By solving the set of five coupled differential equations, we obtain the thermo-hydrodynamical properties of the flow. We show that during infall, ? of the flow could vary up to ˜300%, while ? up to ˜20%. This might have a significant impact to the disk solutions in explaining observed data, e.g. super-luminal jets from disks, luminosity, and then extracting fundamental properties from them. Hence any conclusion based on constant ? and ? should be taken with caution and corrected.

Mukhopadhyay, Banibrata; Dutta, Parikshit

2012-02-01

360

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

PubMed

The work characterizes the changes in volatile and semivolatile PM emissions from a gas turbine engine resulting from burning alternative fuels, specifically gas-to-liquid (GTL), coal-to-liquid (CTL), a blend of Jet A-1 and GTL, biodiesel, and diesel, to the standard Jet A-1. The data presented here, compares the mass spectral fingerprints of the different fuels as measured by the Aerodyne high resolution time-of-flight aerosol mass spectrometer. There were three sample points, two at the exhaust exit plane with dilution added at different locations and another probe located 10 m downstream. For emissions measured at the downstream probe when the engine was operating at high power, all fuels produced chemically similar organic PM, dominated by C(x)H(y) fragments, suggesting the presence of long chain alkanes. The second largest contribution came from C(x)H(y)O(z) fragments, possibly from carbonyls or alcohols. For the nondiesel fuels, the highest loadings of organic PM were from the downstream probe at high power. Conversely, the diesel based fuels produced more organic material at low power from one of the exit plane probes. Differences in the composition of the PM for certain fuels were observed as the engine power decreased to idle and the measurements were made closer to the exit plane. PMID:22913312

Williams, Paul I; Allan, James D; Lobo, Prem; Coe, Hugh; Christie, Simon; Wilson, Christopher; Hagen, Donald; Whitefield, Philip; Raper, David; Rye, Lucas

2012-09-13

361

DAYCENT Model Projections of Land Use Change Impacts on N Gas Emissions in the Central US (Invited)  

NASA Astrophysics Data System (ADS)

Nitrogen additions to cropped soils from fertilizers and symbiotic N fixation are an important source of N2O, NOx, and NH3 emissions. As the need for biofuel feedstock increases, pasture, prairie, and other lands are being converted to biofuel cropping systems. We used the DAYCENT biogeochemical model to quantify emission patterns of N gas related aerosol precursors under current land use and land use changes. DAYCENT is the daily time step version of the CENTURY model and simulates plant growth, soil organic matter decomposition, and the microbial processes that result in N gas emissions. Land use change scenarios considered include conversion of current cropland, pasture, CRP, and abandoned crop land to different biofuel cropping systems under conventional and improved management scenarios. Model results suggest that conversion of cropland to corn ethanol cropping would result in a small increase in emissions but use of improved fertilizers would mitigate this increase. Conversion of pasture, CRP, and abandoned crop land to corn ethanol cropping results in substantial increases in emissions that would only be partially mitigated by using improved fertilizers. However, converting these non-cropped lands to cellulosic biofuel cropping systems, such as switchgrass and miscanthus, would result in a more modest increase in emissions. Converting land already used for cropping to cellulosic biofuel crops would likely result in a decrease in emissions. We conclude that previous land use interacts with current land management strategies to control emissions.

Del Grosso, S.; Parton, W. J.; Ogle, S. M.

2009-12-01

362

A model study of the impact of source gas changes on the stratosphere for 1850-2100  

NASA Astrophysics Data System (ADS)

The long-term stratospheric impacts due to emissions of CO2, CH4, N2O, and ozone depleting substances (ODSs) are investigated using an updated version of the Goddard two-dimensional (2-D) model. Perturbation simulations with the ODSs, CO2, CH4, and N2O varied individually are performed to isolate the relative roles of these gases in driving stratospheric changes over the 1850-2100 time period. We also show comparisons with observations and the Goddard Earth Observing System chemistry-climate model simulations for the time period 1960-2100 to illustrate that the 2-D model captures the basic processes responsible for long-term stratospheric change. The ODSs, CO2, CH4, and N2O impact ozone via several mechanisms. ODS and N2O loading decrease stratospheric ozone via the increases in atmospheric halogen and odd nitrogen species, respectively. CO2 loading impacts ozone by: (1) cooling the stratosphere which increases ozone via the reduction in the ozone chemical loss rates, and (2) accelerating the Brewer-Dobson circulation (BDC) which redistributes ozone in the lower stratosphere. The net result of CO2 loading is an increase in global ozone in the total column and upper stratosphere. CH4 loading impacts ozone by: (1) increasing atmospheric H2O and the odd hydrogen species which decreases ozone via the enhanced HOx-ozone loss rates; (2) increasing the H2O cooling of the middle atmosphere which reduces the ozone chemical loss rates, partially offsetting the enhanced HOx-ozone loss; (3) converting active to reservoir chlorine via the reaction CH4+Cl?HCl+CH3 which leads to more ozone; and (4) increasing the NOx-ozone production in the troposphere. The net result of CH4 loading is an ozone decrease above 40-45 km, and an increase below 40-45 km and in the total column. The 2-D simulations indicate that prior to 1940, the ozone increases due to CO2 and CH4 loading outpace the ozone losses due to increasing N2O and carbon tetrachloride (CCl4) emissions, so that total column and upper stratospheric global ozone reach broad maxima during the 1920s-1930s. This precedes the significant ozone depletion during ~1960-2050 driven by the ODS loading. During the latter half of the 21st century as ODS emissions diminish, CO2, N2O, and CH4 loading will all have significant impacts on global total ozone based on the Intergovernmental Panel on Climate Change (IPCC) A1B (medium) scenario, with CO2 having the largest individual effect. Sensitivity tests illustrate that due to the strong chemical interaction between methane and chlorine, the CH4 impact on total ozone becomes significantly more positive with larger ODS loading. The model simulations also show that changes in stratospheric temperature, BDC, and age of air during 1850-2100 are controlled mainly by the CO2 and ODS loading. The simulated acceleration of the BDC causes the global average age of air above 22 km to decrease by ~1 yr from 1860-2100. The photochemical lifetimes of N2O, CFCl3, CF2Cl2, and CCl4 decrease by 11-13 % during 1960-2100 due to the acceleration of the BDC, with much smaller lifetime changes (<4 %) caused by changes in the photochemical loss rates.

Fleming, E. L.; Jackman, C. H.; Stolarski, R. S.; Douglass, A. R.

2011-08-01

363

An electron impact emission spectroscopy flux sensor for monitoring deposition rate at high background gas pressure with improved accuracy  

SciTech Connect

Electron impact emission spectroscopy (EIES) has been proven to be a critical tool for film composition control during codeposition processes for the fabrication of multicomponent thin film materials including the high-efficiency copper-indium-gallium-diselenide photovoltaic cells. This technique is highly specific to atomic species because the emission spectrum of each element is unique, and the typical width of atomic emission lines is very narrow. Noninterfering emission lines can generally be allocated to different atomic species. However, the electron impact emission spectra of many molecular species are often broadband in nature. When the optical emission from an EIES sensor is measured by using a wavelength selection device with a modest resolution, such as an optical filter or monochromator, the emissions from common residual gases may interfere with that from the vapor flux and cause erroneous flux measurement. The interference is most pronounced when measuring low flux density with the presence of gases such as in reactive deposition processes. This problem is solved by using a novel EIES sensor that has two electron impact excitation sources in separate compartments but with one common port for optical output. The vapor flux is allowed to pass through one compartment only. Using a tristate excitation scheme and appropriate signal processing technique, the interfering signals from residual gases can be completely eliminated from the output signal of the EIES monitor for process control. Data obtained from Cu and Ga evaporations with the presence of common residual gases such as CO{sub 2} and H{sub 2}O are shown to demonstrate the improvement in sensor performance. The new EIES sensor is capable of eliminating the effect of interfering residual gases with pressure as high as in the upper 10{sup -5} Torr range.

Lu, C.; Blissett, C. D.; Diehl, G. [C. Lu Laboratory, 1012A Linda Vista Avenue, Mountain View, California 94043 (United States); Sigma Instruments, 120 Commerce Drive Unit 1, Fort Collins, Colorado 80524 (United States)

2008-07-15

364

Sea-level rise and impacts projections under a future scenario with large greenhouse gas emission reductions  

NASA Astrophysics Data System (ADS)

Using projections from two coupled climate models (HadCM3C and HadGEM2-AO), we consider the effect on 21st century sea-level rise (SLR) of mitigation policies relative to a scenario of business-as-usual (BAU). Around a third of the global-mean SLR over the century is avoided by a mitigation scenario under which global-mean near surface air temperature stabilises close to the Copenhagen Accord limit of a 2°C increase. Under BAU (a variant of the A1B scenario) the model-averaged projected SLR for 2090-2099 relative to 1980-1999 is 0.29 m-0.51 m (5%-95% uncertainties from treatment of land-based ice melt); under mitigation (E1 scenario) it is 0.17 m-0.34 m. This reduction is primarily from reduced thermal expansion. The spatial patterns of regional SLR are fairly dissimilar between the models, but are qualitatively similar across scenarios for a particular model. An impacts model suggests that by the end of the 21st century and without upgrade in defences around 55% of the 84 million additional people flooded per year globally under BAU (from SLR alone) could be avoided under such mitigation. The above projections of SLR follow the methodology of the IPCC Fourth Assessment. We have, however, also conducted a sensitivity study of SLR and its impacts where the possibility of accelerated ice sheet dynamics is accounted for.

Pardaens, A. K.; Lowe, J. A.; Brown, S.; Nicholls, R. J.; de Gusmão, D.

2011-06-01

365

A model study of the impact of source gas changes on the stratosphere for 1850-2100  

NASA Astrophysics Data System (ADS)

The long-term stratospheric impacts due to emissions of CO2, CH4, N2O, and ozone depleting substances (ODSs) are investigated using an updated version of the Goddard two-dimensional (2-D) model. Perturbation simulations with the ODSs, CO2, CH4, and N2O varied individually are performed to isolate the relative roles of these gases in driving stratospheric changes over the 1850-2100 time period. We also show comparisons with observations and the Goddard Earth Observing System chemistry-climate model simulations for the time period 1960-2100 to illustrate that the 2-D model captures the basic processes responsible for long-term stratospheric change. The 2-D simulations indicate that prior to 1940, the ozone increases due to CO2 and CH4 loading outpace the ozone losses due to increasing N2O and carbon tetrachloride (CCl4) emissions, so that ozone reaches a broad maximum during the 1920s-1930s. This preceeds the significant ozone depletion during ~1960-2050 driven by the ODS loading. During the latter half of the 21st century as ODS emissions diminish, CO2, N2O, and CH4 loading will all have significant impacts on global total ozone based on the IPCC A1B (medium) scenario, with CO2 having the largest individual effect. Sensitivity tests illustrate that due to the strong chemical interaction between methane and chlorine, the CH4 impact on total ozone becomes significantly more positive with larger ODS loading. The model simulations also show that changes in stratospheric temperature, Brewer-Dobson circulation (BDC), and age of air during 1850-2100 are controlled mainly by the CO2 and ODS loading. The simulated acceleration of the BDC causes the age of air to decrease by ~1 year from 1860-2100. The corresponding photochemical lifetimes of N2O, CFCl3, CF2Cl2, and CCl4 decrease by 11-13% during 1960-2100 due to the acceleration of the BDC, with much smaller lifetime changes (<4%) caused by changes in the photochemical loss rates.

Fleming, E. L.; Jackman, C. H.; Stolarski, R. S.; Douglass, A. R.

2011-04-01

366

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

367

MODELING THE IMPACT OF ELEVATED MERCURY IN DEFENSE WASTE PROCESSING FACILITY MELTER FEED ON THE MELTER OFF-GAS SYSTEM - PRELIMINARY REPORT  

SciTech Connect

The Defense Waste Processing Facility (DWPF) is currently evaluating an alternative Chemical Process Cell (CPC) flowsheet to increase throughput. It includes removal of the steam-stripping step, which would significantly reduce the CPC processing time and lessen the sampling needs. However, its downside would be to send 100% of the mercury that come in with the sludge straight to the melter. For example, the new mercury content in the Sludge Batch 5 (SB5) melter feed is projected to be 25 times higher than that in the SB4 with nominal steam stripping of mercury. This task was initiated to study the impact of the worst-case scenario of zero-mercury-removal in the CPC on the DWPF melter off-gas system. It is stressed that this study is intended to be scoping in nature, so the results presented in this report are preliminary. In order to study the impact of elevated mercury levels in the feed, it is necessary to be able to predict how mercury would speciate in the melter exhaust under varying melter operating conditions. A homogeneous gas-phase oxidation model of mercury by chloride was developed to do just that. The model contains two critical parameters pertaining to the partitioning of chloride among HCl, Cl, Cl{sub 2}, and chloride salts in the melter vapor space. The values for these parameters were determined at two different melter vapor space temperatures by matching the calculated molar ratio of HgCl (or Hg{sub 2}Cl{sub 2}) to HgCl{sub 2} with those measured during the Experimental-Scale Ceramic Melter (ESCM) tests run at the Pacific Northwest National Laboratory (PNNL). The calibrated model was then applied to the SB5 simulant used in the earlier flowsheet study with an assumed mercury stripping efficiency of zero; the molar ratio of Cl-to-Hg in the resulting melter feed was only 0.4, compared to 12 for the ESCM feeds. The results of the model run at the indicated melter vapor space temperature of 650 C (TI4085D) showed that due to excessive shortage of chloride, only 6% of the mercury fed is expected to get oxidized, mostly as HgCl, while the remaining mercury would exist either as elemental mercury vapor (90%) or HgO (4%). Noting that the measured chloride level in the SB5 qualification sample was an order of magnitude lower than that used in the SB5 simulant, the degree of chloride shortage will be even greater. As a result, the projected level of HgCl in the actual SB5 melter exhaust will be even lower than 6% of the total mercury fed, while that of elemental mercury is likely to be greater than 90%. The homogeneous oxidation of mercury in the off-gas was deemed to be of primary importance based on the postulation that mercury and other volatile salts form submicron sized aerosols upon condensation and thus remain largely in the gas stream downstream of the quencher where they can deposit in the off-gas lines, Steam-Atomized Scrubbers (SAS), and High-Efficiency Mist Eliminator (HEME). Formation of these submicron semi-volatile salts in the condensate liquid is considered to be unlikely, so the liquid phase reactions were considered to be less important. However, subsequent oxidation of mercury in the liquid phase in the off-gas system was examined in a simplified model of the off-gas condensate. It was found that the condensate chemistry was consistent with further oxidation of elemental mercury to Hg{sub 2}Cl{sub 2} and conversion of HgO to chlorides. The results were consistent with the available experimental data. It should also be noted that the model predictions presented in this report do not include any physically entrained solids, which typically account for much of the off-gas carryover on a mass basis. The high elemental mercury vapor content predicted at the DWPF Quencher inlet means that physically entrained solids could provide the necessary surface onto which elemental mercury vapor could condense, thereby coating the solids as well as the internal surfaces of the off-gas system with mercury. Clearly, there are many process benefits to be gained by removing the steam-stripping step from the CPC c

Zamecnik, J.; Choi, A.

2009-03-25

368

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

2012-12-07

369

Impact of oxidation catalysts on exhaust NO2/NOx ratio from lean-burn natural gas engines.  

PubMed

Oxides of nitrogen (NOx) emitted from internal combustion engines are composed primarily of nitric oxide (NO) and nitrogen dioxide (NO2). Exhaust from most combustion sources contains NOx composed primarily of NO. There are two important scenarios specific to lean-burn natural gas engines in which the NO2/NOx ratio can be significant: (1) when the engine is operated at ultralean conditions and (2) when an oxidation catalyst is used. Large NO2/NOx ratios may result in additional uncertainty in NOx emissions measurements because the most common technique (chemiluminescence) was developed for low NO2/NOx ratios. In this work, scenarios are explored in which the NO2/NOx ratio can be large. Additionally, three NOx measurement approaches are compared for exhaust with various NO2/NOx ratios. The three measurement approaches are chemiluminescence, chemical cell, and Fourier-transform infrared spectroscopy. A portable analyzer with chemical cell technology was found to be the most accurate for measuring exhaust NOx with large NO2/NOx ratios. PMID:20681434

Olsen, Daniel B; Kohls, Morgan; Arney, Gregg

2010-07-01

370

MODELING THE IMPACT OF ELEVATED MERCURY IN DEFENSE WASTE PROCESSING FACILITY MELTER FEED ON THE MELTER OFF-GAS SYSTEM-PRELIMINARY REPORT  

SciTech Connect

The Defense Waste Processing Facility (DWPF) is currently evaluating an alternative Chemical Process Cell (CPC) flowsheet to increase throughput. It includes removal of the steam-stripping step, which would significantly reduce the CPC processing time and lessen the sampling needs. However, its downside would be to send 100% of the mercury that comes in with the sludge straight to the melter. For example, the new mercury content in the Sludge Batch 5 (SB5) melter feed is projected to be 25 times higher than that in the SB4 with nominal steam stripping of mercury. This task was initiated to study the impact of the worst-case scenario of zero-mercury-removal in the CPC on the DWPF melter offgas system. It is stressed that this study is intended to be scoping in nature, so the results presented in this report are preliminary. In order to study the impact of elevated mercury levels in the feed, it is necessary to be able to predict how mercury would speciate in the melter exhaust under varying melter operating conditions. A homogeneous gas-phase oxidation model of mercury by chloride was developed to do just that. The model contains two critical parameters pertaining to the partitioning of chloride among HCl, Cl, Cl{sub 2}, and chloride salts in the melter vapor space. The values for these parameters were determined at two different melter vapor space temperatures by matching the calculated molar ratio of HgCl (or Hg{sub 2}Cl{sub 2}) to HgCl{sub 2} with those measured during the Experimental-Scale Ceramic Melter (ESCM) tests run at the Pacific Northwest National Laboratory (PNNL). The calibrated model was then applied to the SB5 simulant used in the earlier flowsheet study with an assumed mercury stripping efficiency of zero; the molar ratio of Cl-to-Hg in the resulting melter feed was only 0.4, compared to 12 for the ESCM feeds. The results of the model run at the indicated melter vapor space temperature of 650 C (TI4085D) showed that due to excessive shortage of chloride, only 6% of the mercury fed is expected to get oxidized, mostly as HgCl, while the remaining mercury would exist either as elemental mercury vapor (90%) or HgO (4%). Noting that the measured chloride level in the SB5 qualification sample was an order of magnitude lower than that used in the SB5 simulant, the degree of chloride shortage will be even greater. As a result, the projected level of HgCl in the actual SB5 melter exhaust will be even lower than 6% of the total mercury fed, while that of elemental mercury is likely to be greater than 90%. The homogeneous oxidation of mercury in the off-gas was deemed to be of primary importance based on the postulation that mercury and other volatile salts form submicron sized aerosols upon condensation and thus remain largely in the gas stream downstream of the quencher where they can deposit in the off-gas lines, Steam-Atomized Scrubbers (SAS), and High-Efficiency Mist Eliminator (HEME). Formation of these submicron semi-volatile salts in the condensate liquid is considered to be unlikely, so the liquid phase reactions were considered to be less important. However, subsequent oxidation of mercury in the liquid phase in the off-gas system was examined in a simplified model of the off-gas condensate. It was found that the condensate chemistry was consistent with further oxidation of elemental mercury to Hg{sub 2}Cl{sub 2} and conversion of HgO to chlorides. The results were consistent with the available experimental data. It should also be noted that the model predictions presented in this report do not include any physically entrained solids, which typically account for much of the off-gas carryover on a mass basis. The high elemental mercury vapor content predicted at the DWPF Quencher inlet means that physically entrained solids could provide the necessary surface onto which elemental mercury vapor could condense, thereby coating the solids as well as the internal surfaces of the off-gas system with mercury. Clearly, there are many process benefits to be gained by removing the steam-stripping step from the CPC c

Zamecnik, J.; Choi, A.

2010-08-18

371

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

372

Outer Continental Shelf oil and gas activities in the Atlantic and their onshore impacts. Atlantic summary report, July 1, 1983-December 31, 1984  

SciTech Connect

The search for oil and gas on the Outer Continental Shelf in the Atlantic continues. Hydrocarbon exploration efforts have been and probably will continue to be concentrated on four major sedimentary basins: the Georges Bank Basin, the Baltimore Canyon Trough, the Carolina Trough, and the Blake Plateau Basin. To date, 46 exploratory wells have been drilled in these areas, most of them in the Mid-Atlantic Planning Area where resource estimates indicate the hydrocarbon potential is the greatest of the three Atlantic Outer Continental Shelf planning areas. Currently, no operators are involved in exploration efforts in the Atlantic. No commercial discoveries have been announced. Since the first and most successful sale of Atlantic Outer Continental Shelf blocks in Lease Sale 40 in August 1976, there have been eight other sales bringing total revenues of almost $3 billion to the Federal Treasury. The current tentative milestone chart for the 5-year offshore leasing schedule calls for four additional lease sales to be held in the Atlantic Outer Continental Shelf. Although no firm plans have been made for the transportation of potential offshore hydrocarbons to onshore processing facilities, it is believed that oil would be transported by tanker or tug-barge system to existing refineries on the Raritan and Delaware Bays. Gas probably would be transported by pipeline to one of several onshore landfalls identifed by Atlantic Coast States and in Federal environmental impact documents. Recent onshore support for Atlantic Outer Continental Shelf exploration came from Davisville, Rhode Island, the only shore support base for the Atlantic that was active during 1984. Three maps are provided in the back pocket of this report for the North Atlantic, Mid-Atlantic and South Atlantic planning areas. 29 refs., 8 figs., 6 tabs.

Rudolph, R.W.; Havran, K.J.

1984-12-01

373

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

374

Impact of flue gas desulfurization-calcium sulfite and gypsum on soil microbial activity and wheat growth  

SciTech Connect

We conducted greenhouse tests to evaluate the effects of FGD-CaSO{sub 3} applied at rates of 0, 2.2, 4.4, and 8.8 Mg ha(-1) on wheat growth, soil enzyme activities, and the chemical properties of two soils with differing pH (4.0 vs. 6.2). A gypsum treatment applied at the rate of 2.2 Mg ha{sup -1} was used as a positive control. Exchangeable Ca{sup 2+} and water-extractable Ca{sup 2+} and SO{sub 4}{sup 2-} increased significantly with increasing FGD-CaSO{sub 3} application. SO{sub 4}{sup 2-} increased in both soils, indicating rapid oxidation of SO{sub 3}{sup 2-} to SO{sub 4}{sup 2-} when neither water nor oxygen was limiting. No changes in soil pH were measured. Applications of 2.2, 4.4, or 8.8 Mg CaSO{sub 3} ha{sup -1} to the pH 6.2 soil produced no effect on wheat growth or the uptake of N, P, Ca{sup 2+}, and Mg{sup 2+}. The uptake of SO{sub 4}{sup 2-} -S increased, whereas K uptake decreased. No significant differences in the activities of urease, {beta}-glucosidase, alkaline phosphatase, or arylsulfatase were observed relative to a control. In the acid soil, an application of 2.2 Mg ha{sup -1} FGD-CaSO{sub 3} increased wheat root growth and dry matter yield compared with an untreated control. The uptake of N, P, Ca{sup 2+}, and K{sup +} also increased presumably because of enhanced root development resulting from decreases in exchangeable Al{sup 3+} and increases in soluble Ca{sup 2+}. Wheat growth and alkaline phosphatase and arylsulfatase activities were significantly inhibited by addition of 8.8 Mg ha{sup -1} of FGD-CaSO{sub 3} compared with the untreated control or the same soil receiving 2.2 Mg ha{sup -1} gypsum. We conclude that surface applications of FGD-CaSO{sub 3} may be as effective as gypsum for inhibiting soil crusting, improving water infiltration, and promoting the movement of Ca{sup 2+} into acid subsoils. Moreover, application rates of equal to or less than 4.4 Mg ha-1 should have no negative impact on soil microbial activities or plant growth.

Lee, Y.B.; Bigham, J.M.; Dick, W.A.; Kim, P.J. [RDA, Suwon (Republic of Korea). National Institute for Agricultural Science and Technology

2008-08-15

375

Spatio-spectral characteristics of ultra-broadband THz emission from two-colour photoexcited gas plasmas and their impact for nonlinear spectroscopy  

NASA Astrophysics Data System (ADS)

We present a characterization of the combined spatial and spectral properties of the terahertz (THz) and mid-infrared emission from gas plasmas generated and driven by two-colour femtosecond optical pulses. For its use in nonlinear spectroscopy, the impact of the relatively complex spatial profile for both broadband (? 10 THz) and ultra-broadband (> 100 THz) emission needs to be considered, in particular for experiments based on z-scan techniques. Here we apply spatially resolved measurements based on both field autocorrelation and sum-frequency (up-conversion) detection. Based on these results, we present simulations of the ultra-broadband profile during its passage through a focal region. In addition to the inherent features of the emission profile due to the generation mechanism in the plasma filament, we also analyse the role of the semconductor (silicon) wafer typically placed after the plasma to discard the optical pump beams, whose photoexcitation also can play a role in the resultant THz profile.

Blank, V.; Thomson, M. D.; Roskos, H. G.

2013-07-01

376

Detection and quantitation of urinary 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid, a metabolite of tetrahydrocannabinol, by capillary gas chromatography and electron impact mass fragmentography.  

PubMed

A procedure for detection and quantitation of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid, a major metabolite of delta-9-tetrahydrocannabinol in urine, has been described. Since the metabolite is present in both conjugated and unconjugated forms, hydrolysis of urine was carried out to increase the sensitivity of detection. The acidic metabolite was isolated by strongly basic anion exchange resin, and subsequently derivatized to methyl 1-dehydroxy-1-methoxy-11-nor-delta-9-tetrahydrocannabinol-9-carbox ylate (1a) by methyliodide in the presence of tetramethylammonium hydroxide. The derivatized product was separated in a capillary column gas chromatograph, and finally detected by a mass spectrometer under electron impact mode. Confirmation of the product was carried out by monitoring three ions that represent the major portions of the molecule and comparing their relative abundances to that of a standard. Quantitation was based on 5'-2H3-11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid as internal standard. Excellent linearity was obtained over the range of 2 to 1000 ng/mL. The overall yield of extraction using the anion exchange resin was 50 to 60%. This extraction process is rapid and suitable for a large number of sample analyses. The methylated product (1a) is stable for at least 72 hr at room temperature. PMID:3029505

Paul, B D; Mell, L D; Mitchell, J M; McKinley, R M; Irving, J

377

bombarded by a flow of molecules and dust The sensor is a target exposed to the impact of particles which impacted their surface with a dust and gas molecules; it is mounted in a plane relative velocity of the order of 70-80 km s -1 . perpendicular to the velocity vector of the probe  

Microsoft Academic Search

The space probes which flew through The emission of secondary electrons and sputtered relative to the cometary nucleus. This electrode ions caused by these impacts was a potential is made of an insulating substrate lined with a source of interference for the experiments which copper foil (printed circuit board) on which a analyzed the gas and plasma environment of the

R. Grard; K. Gringauz

1986-01-01

378

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

379

Comparison of the limulus amebocyte lysate test and gas chromatography-mass spectrometry for measuring lipopolysaccharides (endotoxins) in airborne dust from poultry-processing industries.  

PubMed Central

The lipopolysaccharide (endotoxin) content in airborne dust samples from three different poultry slaughterhouses was determined with both the chromogenic Limulus amebocyte lysate assay and gas chromatography-mass spectrometry analysis of lipopolysaccharide-derived 3-hydroxy fatty acids. Gram-negative cell walls were also measured by using two-dimensional gas chromatography/electron-capture analysis of diaminopimelic acid originating from the peptidoglycan. The correlation between the results of the Limulus assay and those of gas chromatography-mass spectrometry for determination of the lipopolysaccharide content in the dust samples was poor, whereas a good correlation was obtained between lipopolysaccharide and diaminopimelic acid concentrations with the gas chromatographic methods. The results suggest that it is predominantly cell-wall-dissociated lipopolysaccharides that are measured with the Limulus assay, whereas the gas chromatographic methods allow determination of total concentrations of lipopolysaccharide, including Limulus-inactive lipopolysaccharide, gram-negative cells, and cellular debris.

Sonesson, A; Larsson, L; Schutz, A; Hagmar, L; Hallberg, T

1990-01-01

380

Comparison of the limulus amebocyte lysate test and gas chromatography-mass spectrometry for measuring lipopolysaccharides (endotoxins) in airborne dust from poultry-processing industries.  

PubMed

The lipopolysaccharide (endotoxin) content in airborne dust samples from three different poultry slaughterhouses was determined with both the chromogenic Limulus amebocyte lysate assay and gas chromatography-mass spectrometry analysis of lipopolysaccharide-derived 3-hydroxy fatty acids. Gram-negative cell walls were also measured by using two-dimensional gas chromatography/electron-capture analysis of diaminopimelic acid originating from the peptidoglycan. The correlation between the results of the Limulus assay and those of gas chromatography-mass spectrometry for determination of the lipopolysaccharide content in the dust samples was poor, whereas a good correlation was obtained between lipopolysaccharide and diaminopimelic acid concentrations with the gas chromatographic methods. The results suggest that it is predominantly cell-wall-dissociated lipopolysaccharides that are measured with the Limulus assay, whereas the gas chromatographic methods allow determination of total concentrations of lipopolysaccharide, including Limulus-inactive lipopolysaccharide, gram-negative cells, and cellular debris. PMID:2187411

Sonesson, A; Larsson, L; Schütz, A; Hagmar, L; Hallberg, T

1990-05-01

381

Assessing economic impacts to coastal recreation and tourism from oil and gas development in the Oregon and Washington Outer Continental Shelf. Inventory and evaluation of Washington and Oregon coastal recreation resources  

SciTech Connect

The purpose of the three-part study was to assist Materials Management Service (MMS) planners in evaluation of the anticipated social impact of proposed oil and gas development on the environment. The purpose of the report is primarily to analyze the econometric models of the Dornbusch study. The authors examine, in detail, key aspects of the gravity, consumer surplus, and economic effects (input-output) models. The purpose is two-fold. First, the authors evaluate the performance of the model in satisfying the objective for which it was developed: analyzing economic impacts of OCS oil and gas development in California. Second, the authors evaluate the applicability of the modeling approach employed in the Dornbusch study for analyzing potential OCS development impacts in Washington and Oregon. At the end of the report, the authors offer suggestions for any future study of economic impacts of OCS development in Washington and Oregon. The recommendations concern future data gathering procedures and alternative modeling approaches for measuring economic impacts.

Ellis, G.M.; Johnson, N.S.; Chapman, D.

1991-05-01

382

SPECIAL ISSUE DEVOTED TO THE 25th ANNIVERSARY OF THE A.M. PROKHOROV GENERAL PHYSICS INSTITUTE: Generation of laser-pulse-field harmonics in a gas upon impact ionisation of atoms  

NASA Astrophysics Data System (ADS)

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 (Ea = 5.1×109 V cm-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.

Kuzelev, M. V.; Rukhadze, A. A.

2007-10-01

383

Examining the impacts of ethanol (E85) versus gasoline photochemical production of smog in a fog using near-explicit gas- and aqueous-chemistry mechanisms  

NASA Astrophysics Data System (ADS)

This study investigates the air quality impacts of using a high-blend ethanol fuel (E85) instead of gasoline in vehicles in an urban setting when a morning fog is present under summer and winter conditions. The model couples the near-explicit gas-phase Master Chemical Mechanism (MCM v. 3.1) with the extensive aqueous-phase Chemical Aqueous Phase Radical Mechanism (CAPRAM 3.0i) in SMVGEAR II, a fast and accurate ordinary differential equation solver. Summer and winter scenarios are investigated during a two day period in the South Coast Air Basin (SCAB) with all gasoline vehicles replaced by flex-fuel vehicles running on E85 in 2020. We find that E85 slightly increases ozone compared with gasoline in the presence or absence of a fog under summer conditions but increases ozone significantly relative to gasoline during winter conditions, although winter ozone is always lower than summer ozone. A new finding here is that a fog during summer may increase ozone after the fog disappears, due to chemistry alone. Temperatures were high enough in the summer to increase peroxy radical (RO2) production with the morning fog, which led to the higher ozone after fog dissipation. A fog on a winter day decreases ozone after the fog. Within a fog, ozone is always lower than if no fog occurs. The sensitivity of the results to fog parameters like droplet size, liquid water content, fog duration and photolysis are investigated and discussed. The results support previous work suggesting that E85 and gasoline both enhance pollution with E85 enhancing pollution significantly more at low temperatures. Thus, neither E85 nor gasoline is a ‘clean-burning’ fuel.

Ginnebaugh, Diana L.; Jacobson, Mark Z.

2012-12-01

384

Agricultural demands for natural gas and liquefied petroleum gas in the USA  

Microsoft Academic Search

This study endeavors to determine whether farmers adjust their consumption of natural gas and liquefied petroleum gas in response to changes in the unit price of energy. A demand model is specified and estimated. The conclusions suggest that the unit price of natural gas (liquefied petroleum gas) is a factor impacting the quantity of natural gas (liquefied petroleum gas) demanded

Noel D. Uri; Mohinder Gill

1992-01-01

385

The Net Impact of Hydroelectric Reservoir Creation on Greenhouse Gas Emissions: A Study of the Eastmain-1 Reservoir in the Eastern James Bay region of Quebec, Canada  

NASA Astrophysics Data System (ADS)

In order to satisfy present and future energy demands and to minimize greenhouse gas (GHG) emissions, there is a growing need to develop energy sources that are not based on combustion. In the boreal regions of Canada, there is a huge potential for hydroelectricity production. However, in most cases, large areas of the boreal ecosystem must be inundated to create hydroelectric reservoirs. Previous studies have established that reservoirs emit GHGs, but these studies have typically focused on emissions some years after reservoir creation. The critical question that has not been asked is 'what is the net change in the exchange of GHG that results directly from the creation of the reservoir?' - i.e. 'what is the net difference between the landscape scale exchange of GHGs before and after reservoir creation, and how does that net difference change over time from when the reservoir was first created to when it reaches a steady-state condition?'. The Eastmain-1 (EM-1) hydroelectric reservoir, located in the James Bay region of Quebec was created in late 2005 and provides a tremendous opportunity to study the impacts of reservoir creation on GHG emissions which are still largely unknown for this type of land conversion. The creation of the EM-1 hydroelectric reservoir required the flooding of over 600 km2 of the boreal ecosystem along the Eastmain River, of which 65% was occupied by forest, 14% by peatland, and 21% by lakes and rivers. In order to assess the impacts of the creation of the reservoir on GHG emissions, three eddy covariance (EC) tower flux sites were established in a black spruce forest, peatland and on an island in the reservoir itself to measure continuous net ecosystem exchange (NEE) of CO2. Together, these represent the dominant terrestrial pre-flooded (forest and peatland) and post-flooded (reservoir) environments. The forest and reservoir EC systems were installed and operational by the end of summer 2006 with the peatland site coming on-line summer of 2008. Through the use of the forest and peatland analogue sites, the EC results will be used to evaluate the pre-flooded vs. post- flooded CO2 fluxes, and thus the net impact of the EM-1 reservoir creation in terms of CO2 emissions. By measurement and modeling, we will provide an estimate of the change in GHG source the atmosphere would see, an estimate of the net emissions that can be used for intercomparison of GHG contributions with other modes of power production and a basis on which to develop biogeochemically sound, verifiable, and transparent estimates for GHG accounting. This presentation will provide an overview of the project and its goals and will discuss preliminary results from the EC and terrestrial measurement campaigns.

Strachan, I. B.; Lemieux, M.; Bonneville, M.; Roulet, N.; Tremblay, A.

2009-05-01

386

Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017. Western Planning Areas Lease Sales 229, 233, 238, 246 and 248. Central Planning Area Lease Sales 227, 231, 235, 241 and 247. Final Environmental Impact Statement. Volume I: Chapters 1-4.1.  

National Technical Information Service (NTIS)

This environmental impact statement (EIS) addresses 10 proposed Federal actions that offer for lease areas on the Gulf of Mexico (GOM) Outer Continental Shelf (OCS) that may contain economically recoverable oil and gas resources. Under the Proposed Final ...

2012-01-01

387

Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017. Western Planning Area Lease Sales 229, 233, 238, 246, and 248. Central Planning Area Lease Sales 227, 231, 235, 241, and 247. Final Environmental Impact Statement. Volume III: Chapters 6-8, Keyword Index, Figures, Tables, and Appendices.  

National Technical Information Service (NTIS)

This environmental impact statement (EIS) addresses 10 proposed Federal actions that offer for lease areas on the Gulf of Mexico (GOM) Outer Continental Shelf (OCS) that may contain economically recoverable oil and gas resources. Under the Proposed Final ...

2012-01-01

388

Guide to new natural gas utilization technologies  

Microsoft Academic Search

The natural gas industry in the United States is undergoing a fundamental transition as the wellhead price is decontrolled. The phased decontrol of new gas under the Natural Gas Policy Act of 1978 (NGPA) has had a dramatic positive impact on the natural gas supply picture. For the first time in 15 years the U.S. gas industry - which accounts

Hay

1985-01-01

389

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

390

Outer Continental Shelf oil and gas information program. Outer Continental Shelf and onshore oil and gas activities and impacts in the Arctic: a summary report. Update 1, May 1982  

Microsoft Academic Search

This report was written to provide State and local officials in Alaska and other interested parties with current planning information about oil- and gas-related activities on the North Slope. Although only one exploratory well has been drilled on the Arctic OCS, the area has a long history of oil- and gas-related activities. The State has leased land on the North

J. B. Jackson; B. C. Pretz

1982-01-01

391

Bubble formation via multidrop impacts  

Microsoft Academic Search

Gas bubbles are often generated when droplets impact a liquid-air interface. For the impact of single droplets, a critical impact velocity must be exceeded for air to be entrained in the form of bubbles. Here we establish that bubbles can be generated at much lower velocities provided that two or more drops impact the liquid-air interface within a sufficiently short

Alexander G. Bick; William D. Ristenpart; Ernst A. van Nierop; Howard A. Stone

2010-01-01

392

Impact of Gas-Phase Mechanisms on Weather Research Forecasting Model with Chemistry (WRF/Chem) Predictions: Mechanism Implementation and Comparative Evaluation  

EPA Science Inventory

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 cond...

393

Analysis of existing and potential environmental regulatory initiatives and their impact on the domestic natural gas industry. Topical report, July 1992February 1994  

Microsoft Academic Search

The report identifies and evaluates the costs of compliance associated with current and potential environmental requirements facing the domestic natural gas industry. It also investigates the market for environmental technologies and current technology transfer. The primary findings of this report include: Future environmental compliance requirements on the domestic natural gas industry must be assessed within the overall context of the

M. L. Godec; G. E. Smith; B. Kosowski; M. C. Lang

1994-01-01

394

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

395

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

396

Alternative sources of gas supply  

Microsoft Academic Search

The alternative sources considered include imported liquefied natural gas, and substitute natural gas produced from oil, coal, oil shale, peat, and biomass. Data are included on fuel prices, electricity prices, environmental impacts, fossil fuel resources, and unconventional sources of natural gas. It is noted that some of the technologies to tap these resources are in early stages of development and

1978-01-01

397

68 FR 47362 - Notice of Availability of the Draft Environmental Impact Statement on the Resource Development...  

Federal Register 2010, 2011, 2012, 2013

...Group Uinta Basin Natural Gas Project. The DEIS...impacts of a proposed natural gas development on 79...the Atchees Wash oil and gas production...analyzes proposed natural gas development in 79...the Atchees Wash oil and gas...

2003-08-08

398

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...

399

Effect of coal constituets on the liquid-assisted capture of impacting ash particles in direct coal-fired gas turbines  

Microsoft Academic Search

With the growing interest in burning pulverized coal directly in gas turbines, the problem of fouling--blockage of hot-gas pathways by thick ash deposits--is receiving increased attention. The inertial deposition rate of supermicron ash, which determines the fouling propensity of the coal via the thickness of the deposit, depends linearly on the sticking fraction of ash material arriving at the cooled

R. Nagarajan; R. J. Anderson

1988-01-01

400

Impact cratering and catastrophic disruption of porous targets through hypervelocity impact experiments  

Microsoft Academic Search

We present an experimental study of impact cratering and fragmentation processes onto low density materials by means of high velocity impact experiments using a two-stage light-gas gun, the impact facility of CISAS \\

F. Ferri; C. Giacomuzzo; D. Pavarin; A. Francesconi; A. Bettella; E. Flamini; F. Angrilli

2006-01-01

401

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

402

Identification and determination of chlorinated paraffins using multivariate evaluation of gas chromatographic data.  

PubMed

Chlorinated paraffins (CPs) were found in the biodegradable fraction of source separated waste from Uppsala, Sweden. We identified and quantified the CPs by multivariate evaluation of gas chromatography-electron capture detection chromatograms. Using principal component analyses (PCA) we identified different types of CP-formulations and also obtain quantitative data. PCA yielded better identifications of individual CP-formulations than visual comparison of chromatograms. Partial least squares regression gave good calibration curves of the standards, but did not work for the waste samples. No source of CPs could be identified in the waste collection chain, and as the waste samples seemed to contain at least two different CP-formulations the source was probably to be found in the waste material itself. The method was used to determine CPs in additional environmental samples, demonstrating that multivariate methods may be developed into a powerful tool for identification and quantification of complex mixture. PMID:22325442

Nilsson, Marie-Louise; Bengtsson, Staffan; Kylin, Henrik

2012-01-11

403

Northeast Regional Environmental Impact Study: air-quality technical report. [Conversion of gas and oil electricity-generating facilities to coal  

SciTech Connect

The potential for cumulative and interactive environmental impacts associated with the proposed conversion to coal of up to 42 powerplants in the Northeast Region of the United States under the Powerplant and Industrial Fuel Use Act of 1978 (Pub. L. 95-620) is being evaluated. The Northeast Regional Environmental Impact Study provides analysis in four interrelated areas: air quality; solid waste disposal; fuel supply and the transportation of fuel and solid waste; and health effects. This document is a description of the air quality analyses of the potential conversions. The document lists the emission scenarios examined, the atmospheric transport and dispersion models used, the operational assumptions made, and the results obtained in this study. In addition, a new method for analyzing the air quality impacts of a proposed action, and the effectiveness of various control strategies in mitigating these impacts, are presented.

Kornegay, F.C.; Tevepaugh, J.A.; Dungey, C.E.; Humrickhouse, S.A.; Shannon, J.D.

1982-03-01

404

Offshore oil and gas activity impact. Hearings before the Committee on Energy and Natural Resources, US Senate, One Hundred Sixth Congress, First Session, January 27, 1999  

SciTech Connect

The purpose of this hearing is hear of the impacts of offshore exploration and production activities on coastal states and communities as it relates to Senate Bill 25. This bill would remedy current inequities by redistributing 50 percent of the Outer Continental Shelf (OCS) revenues to three programs: coastal impact assistance, local park and recreation, and wildlife programs. Statements were heard from representatives from three of the Gulf Coast States, as well as Alaska.

NONE

1999-07-01

405

Outer Continental Shelf oil and gas information program: outer continental shelf oil and gas activities in the Gulf of Mexico and their onshore impacts. A summary report, September 1980  

Microsoft Academic Search

The Gulf of Mexico Outer Continental Shelf (OCS) is an important oil- and gas- producing region with a long history. Its volume of production is greater than that of any other offshore region in the world. Most of the known hydrocarbon deposits in the area are situated off the coasts of Texas and Louisiana, where geologic structures associated with salt

K. J. Havran; K. M. Collins

1980-01-01

406

Supplemental Generic Environmental Impact Statement On The Oil, Gas and Solution Mining Regulatory Program: Well Permit Issuance for Horizontal Drilling and High-Volume Hydraulic Fracturing to Develop the Marcellus Shale and Other Low-Permeability Gas Reservoirs. (Revised Draft).  

National Technical Information Service (NTIS)

In New York, the primary target for shale-gas development is currently the Marcellus Shale, with the deeper Utica Shale also identified as a potential resource. Additional low-permeability reservoirs may be considered by project sponsors for development b...

E. Leff

2011-01-01

407

Impact of electric range and fossil fuel price level on the economics of plug-in hybrid vehicles and greenhouse gas abatement costs  

Microsoft Academic Search

In this paper, the energy consumption shares of plug-in hybrid vehicles (PHEVs) for electricity from the grid and conventional fuel depending on electric driving range are estimated. The resulting mobility costs and greenhouse gas (GHG) abatement costs per vehicle kilometer for the year 2030 are calculated and optimal electric driving range (which indicates the size of the battery) is found

Niklas Hartmann

2012-01-01

408

Studies on the impact, detection, and control of microbiology influenced corrosion related to pitting failures in the Russian oil and gas industry. Final CRADA report  

Microsoft Academic Search

The objectives of the Project are: (1) to design effective anti-corrosion preparations (biocides, inhibitors, penetrants and their combinations) for gas- and oil-exploration industries; (2) to study a possibility of development of environmentally beneficial ('green') biocides and inhibitors of the new generation; (3) to develop chemical and microbiological methods of monitoring of sites at risk of corrosion; and (4) to evaluate

Ehst

2006-01-01

409

Effect of chlorine dioxide gas on Salmonella enterica inoculated on navel orange surfaces and its impact on the quality attributes of treated oranges.  

PubMed

Microorganisms, including pathogens of public health significance, have been shown to contaminate orange juice during the mechanical extraction of juice. The problem gets exacerbated when washed oranges have high initial microbial load, due to an insufficient postharvest treatment. The objective of this study was to investigate the reduction of Salmonella enterica on orange surfaces using ClO? gas treatments to achieve a 5 log reduction, consistent with the recommendations of the U.S. Department of Agriculture-National Advisory Committee on Microbiological Criteria for Foods. A mixed culture of four Salmonella strains, isolated from previous orange juice outbreaks, was spot inoculated onto orange skin surface areas. The oranges were then treated with 0.1, 0.3, and 0.5 mg/L ClO? gas for 2-14 minutes at 22°C and 90%-95% relative humidity. Surviving bacteria on treated areas were recovered and enumerated over treatment time on a nonselective medium, tryptic soy agar, followed by culturing onto a selective medium, xylose lysine deoxycholate agar. A >5 log reduction of Salmonella per sample of orange surface was observed with 0.1 and 0.3 mg/L ClO? gas treatments at 14 minutes and a similar log reduction was observed at 0.5 mg/L ClO? gas at 10 minutes. This result demonstrates that the treatment of oranges with ClO? gas is a promising technology that could be successfully employed for the treatment of whole oranges to reduce the risk of Salmonella outbreaks in orange juice. PMID:20932090

Bhagat, Arpan; Mahmoud, Barakat S M; Linton, Richard H

2010-10-08

410

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

Microsoft Academic Search

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

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

2007-01-01

411

Oiling the gears of public participation: the value of organisations in establishing Trinity of Voice for communities impacted by the oil and gas industry  

Microsoft Academic Search

With energy crises looming, conflicts over resource extraction and production are on the rise. For communities lacking voice to participate in these conflicts, community-based organisations and local non-governmental organisations help to unite, communicate, and negotiate with other stakeholders. In this paper we compare two cases that demonstrate the roles of organisations in providing voice to citizenry impacted by environmental justice

Jessica A. Klassen; Andrea M. Feldpausch-Parker

2011-01-01

412

The impact of a naturally occurring CO 2 gas vent on the shallow ecosystem and soil chemistry of a Mediterranean pasture (Latera, Italy)  

Microsoft Academic Search

Recent research into CO2 geological storage has shown that it has potential to be a safe and effective way to rapidly decrease short-term anthropogenic CO2 emissions. Despite this progress, stakeholders must be convinced that the scientific community has studied all possible scenarios, including a potential leak into the biosphere. To better understand the potential impact of such an event, a

S. E. Beaubien; G. Ciotoli; P. Coombs; M. c. Dictorc; M. Krüger; S. Lombardi; J. M. Pearce; J. M. West

2008-01-01

413

Service embrittlement of gas turbine blade alloys Udimet 710 and IN-738: Volume 2, Atlas of micrographs and impact toughness: Final report  

SciTech Connect

This report is issued as an addendum to the main report on the effect of aging on impact toughness and microstructure of turbine blade superalloys Udimet 710 (U-710) and IN-738 (high carbon version). In this study, it was found that for the standard heat treatment and varying aging conditions, (1000, 5000, and 10,000 h at 790/degree/C (1454/degree/F), 830/degree/C (1526/degree/F) and 900/degree/C (1652/degree/F)), the cast alloy IN-738 suffers no loss of impact toughness. On the other hand, the impact properties of heat-treated wrought U-710 moderately degraded for aging times up to 5000 h at 790/degree/ C (1454/degree/F) and severely degraded for aging times of 1000 h and greater at temperatures at and above 830/degree/C (1526/degree/F). In this addendum, an Atlas of photomicrographs showing the detailed evolution of microstructure with aging is presented for both materials. The Atlas may be used to assess the degree of embrittlement that has taken place in service-run blades by comparing the aged microstructure of the blade with those in the Atlas and corresponding impact toughness values, which are repeated in this addendum for easy reference. 44 figs., 9 tabs.

Pard, A.G.

1989-07-01

414

Gas and Gas Pains  

MedlinePLUS

... inflammatory bowel disease, such as ulcerative colitis or Crohn's disease. Antibiotics. In some cases of excess gas, antibiotic ... you eat and drink. Don't smoke. Cigarette smoking can increase the amount of air you swallow. ...

415

Impacts of climate change on ground level gas-phase pollutants and aerosols in the Iberian Peninsula for the late XXI century  

NASA Astrophysics Data System (ADS)

Climate change alone influences future air pollution levels through modifications of gas-phase chemistry, transport, removal, and natural emissions. Hence, the goal of this study is to determine at what extent concentrations of air pollutants respond to changes over the Iberian Peninsula under a climate change scenario. The methodology includes the use of the regional modeling system MM5 (regional climate model version)-CHIMERE for two nested domains covering Europe and the Iberian Peninsula. Two time slices driven by ECHO-G global circulation model covering from 1991 to 2010 and 2071 to 2100 under the SRES A2 scenario have been compared. Climate change influences the concentrations of both gas-phase pollutants and aerosols through changes in temperature, precipitation, mixing height, transport, humidity, and oxidant levels. The trends of variation of ozone (changes up to 5 ppb, +10% increase during summertime) and aerosols over southwestern Europe are influenced by the higher mean temperature modeled for the future climate (up to +5.4 K), since it favors the formation of secondary gas-phase products. It also enhances sulphates (+2 ?g m-3) and secondary organic aerosols (SOA) (+2.5 ?g m-3 under SRES A2 scenario) and contributes to the decomposition of ammonium nitrate, remaining in the gas phase. Further, the 17% percent decrease of precipitation modeled for 2071-2100 has a strong effect in the frequency of the washout and therefore in the levels of natural aerosols: the concentrations of aerosols decrease with increasing precipitation as wet deposition provides the main aerosol sink.

Jiménez-Guerrero, Pedro; Montávez, Juan Pedro; Gómez-Navarro, Juan José; Jerez, Sonia; Lorente-Plazas, Raquel

2012-08-01

416

Evaluation of Tyro3 expression, Gas6-mediated Akt phosphorylation, and the impact of anti-Tyro3 antibodies in melanoma cell lines.  

PubMed

Tyro3, a member of the Tyro3/Axl/Mer (TAM) family of receptor tyrosine kinases, has emerged as a potential oncogene in melanoma. Here, we confirm that Tyro3 is specifically overexpressed in primary melanoma samples and show that Tyro3 is expressed at varying levels in numerous melanoma cell lines. Short hairpin RNA-mediated knockdown of Tyro3 led to significant cell death via apoptotic mechanisms in nearly all melanoma cell lines tested, regardless of the BRAF or NRAS mutation status or co-expression of Axl and/or Mer. We generated soluble and monomeric versions of the human Tyro3 extracellular domain and human Gas6 for affinity measurements and correlated these values with the level of Gas6 required to induce Tyro3 signaling in cellular assays. Calcium was critical for the correct folding of Gas6 and its binding to Tyro3. In melanoma cell lines, Gas6 induced Tyro3 phosphorylation and downstream Akt phosphorylation without apparent effects on Erk. We generated monoclonal antibodies (mAbs) against Tyro3 to examine their effect on survival signaling in melanoma cell lines. The mAbs generated against Tyro3 included nonligand blockers, partial blockers, and competitive ligand blockers. A number of weak and partial ligand blockers (all recognizing the Tyro3 Ig domains) were the most effective at blocking ligand-mediated downstream signaling of Tyro3. Overall, these data indicate that Tyro3 may confer increased survival signals in melanoma cells and can be stymied using inhibitory mAbs. These mAbs may be useful for further investigations of the role of Tyro3 in melanoma. PMID:23570341

Demarest, Stephen J; Gardner, Jennifer; Vendel, Michelle C; Ailor, Eric; Szak, Suzanne; Huang, Flora; Doern, Adam; Tan, Xiangyang; Yang, Weixing; Grueneberg, Dorre A; Richards, Edward J; Endege, Wilson O; Harlow, Ed; Koopman, Louise A

2013-04-24

417

ENVIRONMENT, HEALTH, AND BEHAVIOR Dietary Sodium Bicarbonate, Cool Temperatures, and Feed Withdrawal: Impact on Arterial and Venous Blood-gas Values in Broilers  

Microsoft Academic Search

Sodium bicarbonate (NaHCO3) has been used successfully in mammals and birds to alleviate pul- monary hypertension. Experiment 1 was designed to pro- vide measurements of arterial and venous blood-gas val- ues from unanesthetized male broilers subjected to a cool temperature (16°C) challenge and fed either a control diet or the same diet alkalinized by dilution with 1% NaHCO3. The incidences

R. F. Wideman; D. M. Hooge; K. R. Cummings

418

Estimation of Potential Impacts from Offshore Liquefied Natural Gas Terminals on Red Snapper and Red Drum Fisheries in the Gulf of Mexico: An Alternative Approach  

Microsoft Academic Search

As of October 1, 2005, seven offshore liquefied natural gas (LNG) terminals have been proposed to be sited in offshore waters of the Gulf of Mexico. Six of these facilities have opted to use open-rack vaporizers (ORVs) to heat and regasify the LNG and one plans to use a combination open-closed-loop system. Each of the terminals would require on the

Benny J. Gallaway; William J. Gazey; John G. Cole; Robert G. Fechhelm

2007-01-01

419

Hugoniot measurement by hyper-velocity impact at velocities up to 9 km\\/s using a two-stage light-gas gun under optimized shot conditions  

Microsoft Academic Search

The optimization for acceleration of a projectile was performed by varying piston mass in consideration with the correlation with projectile mass and the engineering limits of the two-stage light-gas gun, and the projectile velocity has been achieved 9.2km\\/s using the optimum acceleration conditions. Moreover, the Hugoniot measurements of oxygen-free copper were performed using the line reflection method at pressures up

M. Yokoo; N. Kawai; K. G. Nakamura; K. Kondo

2008-01-01

420

Br2 production from the heterogeneous reaction of gas-phase OH with aqueous salt solutions: Impacts of acidity, halide concentration, and organic surfactants.  

PubMed

This study reports the first laboratory measurement of gas-phase Br2 production from the reaction between gas-phase hydroxyl radicals and aqueous salt solutions. Experiments were conducted at 269 K in a rotating wetted-wall flow tube coupled to a chemical-ionization mass spectrometer for analysis of gas-phase components. From both pure NaBr solutions and mixed NaCl/NaBr solutions, the amount of Br2 released was found to increase with increasing acidity, whereas it was found to vary little with increasing concentration of bromide ions in the sample. For mixed NaCl/NaBr solutions, Br2 was formed preferentially over Cl2 unless the Br- levels in the solution were significantly depleted by OH oxidation, at which point Cl2 formation was observed. Presence of a surfactant in solution, sodium dodecyl sulfate, significantly suppressed the formation of Br2; this is the first indication that an organic surfactant can affect the rate of interfacial mass transfer of OH to an aqueous surface. The OH-mediated oxidation of bromide may serve as a source of active bromine in the troposphere and contribute to the subsequent destruction of ozone that proceeds in marine-influenced regions of the troposphere. PMID:16942051

Frinak, Elizabeth K; Abbatt, Jonathan P D

2006-09-01

421

Impact of improved technology on potential reserves of tight gas in East Texas and Northwestern Louisiana. Final topical report, October 1, 1989-September 30, 1990  

SciTech Connect

The East Texas/Northwestern Louisiana area has been one of the most active tight gas plays over the past decade. Advances in formation evaluation and stimulation technologies offer the prospect of increased reserves at reduced costs from remaining tight gas resource. The purpose of the study was to estimate the remaining potential production from the low permeability portions of the Cotton Valley and Travis Peak Formations, the largest tight gas formations in the area. For a 14,000 square mile study area that straddles the Texas/Louisiana border and the Sabine Uplift, a remaining estimated 2.8 Tcf is technically recoverable from the Cotton Valley Sand and 1.2 Tcf from the Upper Travis Peak. These estimates were based on a regional geologic appraisal of currently producing reservoirs. Typical wells were analyzed and used as the basis to extrapolate expected future production from the remaining undeveloped areas of these reservoirs. The analysis incorporated potential improvements in formation evaluation and stimulation technologies and current costing and industry financial parameters to estimate potential reserves at alternative wellhead prices. Reservoir data and analysis results can be used to identify which geological and technical parameters are most important to efficient recovery of East Texas tight sands. Three case studies are also presented of improved technologies in the study area over the past decade. The studies indicate that technology improvements have been made in the design and implementation of new stimulation technologies, as well as in formation evaluation and reservoir management.

Haas, M.R.

1990-12-01

422

Service embrittlement of gas turbine blade alloys Udimet 710 and IN738: Volume 2, Atlas of micrographs and impact toughness: Final report  

Microsoft Academic Search

This report is issued as an addendum to the main report on the effect of aging on impact toughness and microstructure of turbine blade superalloys Udimet 710 (U-710) and IN-738 (high carbon version). In this study, it was found that for the standard heat treatment and varying aging conditions, (1000, 5000, and 10,000 h at 790\\/degree\\/C (1454\\/degree\\/F), 830\\/degree\\/C (1526\\/degree\\/F) and

Pard

1989-01-01

423

Absolute cross sections for electron-impact ionization of the rare-gas atoms by the fast-neutral-beam method  

Microsoft Academic Search

A new apparatus has been constructed for the measurement of absolute partial electron-impact-ionization cross sections of neutral atoms, molecules, and free radicals. A fast neutral beam is prepared by charge-transfer neutralization of a mass-selected ion beam and is ionized as it crosses an electron beam. From careful analysis of the apparatus, the absolute accuracy of measured cross sections is calculated

Robert C. Wetzel; Frank A. Baiocchi; Todd R. Hayes; Robert S. Freund

1987-01-01

424

Toward the Impact of Fuel Evaporation-Combustion Interaction on Spray Combustion in Gas Turbine Combustion Chambers. Part II: Influence of High Combustion Temperature on Spray Droplet Evaporation  

Microsoft Academic Search

\\u000a While the first part of this work dealt with the question related to the impact of partial vaporization on spray flame properties,\\u000a the second part attempts to answer the question how the evaporation process behaves under turbulent premixed combustion conditions.\\u000a According to the Eulerian-Lagrangian RANS-based spray module designed in Part I the non-equilibrium evaporation model, that\\u000a was proven to capture accurately

Amsini Sadiki; W. Ahmadi; Mouldi Chrigui

425

The impact of plug-in vehicles on greenhouse gas and criteria pollutants emissions in an urban air shed using a spatially and temporally resolved dispatch model  

Microsoft Academic Search

With the introduction of plug-in vehicles (PEVs) into the light-duty vehicle fleet, the tail-pipe emissions of GHGs and criteria pollutants will be partly transferred to electricity generating units. To study the impact of PEVs on well-to-wheels emissions, the U.S. Western electrical grid serving the South Coast Air Basin (SoCAB) of California is modeled with both spatial and temporal resolution at

Ghazal Razeghi; Tim Brown; G. Scott Samuelsen

2011-01-01

426

Structural determination of zinc dithiophosphates in lubricating oils by gas chromatography–mass spectrometry with electron impact and electron-capture negative ion chemical ionization  

Microsoft Academic Search

Pentafluorobenzyl ester derivatives were used to identify zinc dialkyldithiophosphates and diaryldithiophosphates anti-wear engine oil additives by GC–electron impact ionization (EI) MS and GC–electron-capture negative ion chemical ionization (ECNCI) MS analysis. GC–EI-MS of the dialkyldithiophosphate–pentafluorobenzyl derivatives afforded characteristic fragment ions corresponding to the cleavage of one and two alkyl radicals. In most cases, information was only obtained on one alkyl chain.

M Becchi; F Perret; B Carraze; J. F Beziau; J. P Michel

2001-01-01

427

A Critical Interaction between Dopamine D2 Receptors and Endocannabinoids Mediates the Effects of Cocaine on Striatal GABAergic Transmission  

Microsoft Academic Search

Compelling evidence indicates that endocannabinoids are implicated in drug addiction. In the present study, we have addressed the interaction between cocaine and endocannabinoid system by means of neurochemical and neurophysiological experiments in rat brain slices. Using gas chromatography–electron impact mass spectrometry, we have found that cocaine increased the levels of the endocannabinoid anandamide in the striatum, a brain area primarily

Diego Centonze; Natalia Battista; Silvia Rossi; Nicola B Mercuri; Alessandro Finazzi-Agrò; Giorgio Bernardi; Paolo Calabresi; Mauro Maccarrone

2004-01-01

428

Life-cycle analysis of shale gas and natural gas.  

SciTech Connect

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 key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.

Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M. (Energy Systems); ( EVS)

2012-01-27

429

Giant Methane Plumes, Gas Hydrate Mounds, and large Pockmarks on the Umitaka Spur, Eastern Margin of Japan Sea: Impact of the Sea Level Fall during the LGM  

NASA Astrophysics Data System (ADS)

Methane plumes have been observed on the Umitaka spur in the eastern margin of Japan Sea. The spur is characterized by a number of large pockmarks and mounds. ROV Hyper-Dolphin has revealed seafloor gas hydrates, gas venting sites, bacterial mats on the mounds and methane-derived carbonate nodules on the spur and nearby knoll. Seismic profiles and piston coring surveys indicate that the mounds are formed by densely accumulated methane hydrates at shallow depths. Fishery echo sounder of 38 KHz has identified a number of giant flares of methane plumes, 550 to 650 m high, over the gas hydrate bearing mounds. CH4 concentration profiles at 25 exhibit characteristic patterns with peak concentrations at two horizons; 40 to 2040 nmol/L in the intermediate waters of 400 to 800 m, and 6 to 45 nmol/L in shallow waters of 300 - 200 m. Temperature of waters are unusually low; Surface water temperature, 25deg, drops down to 1 deg at 300 m, and 0.5 to 0.2 deg for waters over 500 m. The T-P conditions of the water on the spur are within the stability of methane hydrate. Gas bubbles in such cold waters should be crystallized as methane hydrate, or probably covered by thin films of hydrate. Once methane bubbles are coated by hydrate, inner pressure of ascending bubbles should exceed the pressure of surrounding waters, and eventually the bubbles should burst at depths depending on the initial size of bubbles. Broken bubbles are coated again, and ascend along with hydrate fragments up to the phase boundary at around 300 m, where the hydrate should be dissociated and methane is dissolved in shallow waters. Deep and shallow methane peaks are thought to correspond to the bubble burst horizon and phase boundary, respectively. Methane seeps on deep sea floor are effectively transported to shallow waters though cold water mass. Analysis of foraminiferal assemblage and C-14 age determination on the Umitaka spur have revealed that benthic foraminiferal abundance decreases while Stainforcia rotundata, characteristic species in methane enriched environments, appeared and drastically increased toward the LGM, when the sea level dropped by 120 m in Japan Sea. Carbon isotopic composition of benthic foraminifers rapidly decreased from '|1.5 to '|3.0 permil PDB in only 7000 years from 21 to 27 kyr. Such a large negative excursion has never been identified in Japan Sea. The interstitial water geochemistry has revealed that the spur is underlain by extensive freshwater pools as a heritage of massive dissociation of subsurface methane hydrates. On the other hand, U-Th ages of the methane-induced carbonates on the spur tend to center around 20 to 30 kyr (Watanabe et al., 2006). Above lines of evidence strongly suggest that the sea level drop at the LGM caused massive dissociation of subsurface methane hydrates, resulting in an enormous release of methane. A rapid build-up of hydrate-derived free gas within gas chimneys may have pushed up massive bodies of methane hydrates into the overlying water columns. LGM caused dissociation of methane hydrate, a strong methane release event, and probably serious environmental perturbation in Japan Sea.

Matsumoto, R.; Hiruta, A.; Takeuchi, E.; Ishizaki, O.; Aoyama, C.; Machiyama, H.

2006-12-01

430

The carbon kinetic isotope effects of ozone-alkene reactions in the gas-phase and the impact of ozone reactions on the stable carbon isotope ratios of alkenes in the atmosphere  

NASA Astrophysics Data System (ADS)

The kinetic isotope effects (KIEs) for several ozone-alkene reactions in the gas phase were studied in a 30 L PTFE reaction chamber. The time dependence of the stable carbon isotope ratios and the concentrations were determined using a gas chromatography combustion isotope ratio mass spectrometry (GCC-IRMS) system. The following average KIE values were obtained: 18.9 +/- 2.8 (ethene), 9.5 +/- 2.5 (propene), 8.7 +/- 1 (1-butene), 8.1 +/- 0.4 (E-2-butene), 7.9 +/- 0.4 (1,3-butadiene), 6.7 +/- 0.9 (1-pentene), 7.3 +/- 0.2 (Z-2-pentene), 6.7 +/- 0.7 (cyclopentene), 6.1 +/- 1 (isoprene), 5.0 +/- 0.7 (1-hexene), 5.6 +/- 0.5 (cyclohexene), and 4.3 +/- 0.7 (1-heptene). These data are the first of their kind to be reported in the literature. The ozone-alkene KIE values show a systematic inverse dependence from alkene carbon number. Based on the observed KIEs, the contribution of ozone-alkene reactions to the isotopic fractionation of alkenes in the atmosphere can be estimated. On average this contribution is generally small compared to the impact of reaction with OH radicals. However, when OH-concentrations are very low, e.g. during nighttime and at high latitudes in winter, the contribution of the ozone reaction dominates and under these conditions the ozone-alkene reaction will have a clearly visible impact on the stable carbon isotope ratio of atmospheric alkenes.

Iannone, R.; Anderson, R. S.; Rudolph, J.; Huang, L.; Ernst, D.

2003-07-01

431

Soil radium, soil gas radon and indoor radon empirical relationships to assist in post-closure impact assessment related to near-surface radioactive waste disposal.  

PubMed

Least squares (LS), Theil's (TS) and weighted total least squares (WTLS) regression analysis methods are used to develop empirical relationships between radium in the ground, radon in soil and radon in dwellings to assist in the post-closure assessment of indoor radon related to near-surface radioactive waste disposal at the Low Level Waste Repository in England. The data sets used are (i) estimated ²²?Ra in the < 2 mm fraction of topsoils (eRa226) derived from equivalent uranium (eU) from airborne gamma spectrometry data, (ii) eRa226 derived from measurements of uranium in soil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. For models comparing indoor radon and (i) eRa226 derived from airborne eU data and (ii) soil gas radon data, some of the geological groupings have significant slopes. For these groupings there is reasonable agreement in slope and intercept between the three regression analysis methods (LS, TS and WTLS). Relationships between radon in dwellings and radium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given radium or soil gas radon concentration in the ground. The regression models comparing indoor radon with soil gas radon have intercepts close to 5 Bq m?³ whilst the intercepts for those comparing indoor radon with eRa226 from airborne eU vary from about 20 Bq m?³ for a moderately permeable geological unit to about 40 Bq m?³ for highly permeable limestone, implying unrealistically high contributions to indoor radon from sources other than the ground. An intercept value of 5 Bq m?³ is assumed as an appropriate mean value for the UK for sources of indoor radon other than radon from the ground, based on examination of UK data. Comparison with published data used to derive an average indoor radon: soil ²²?Ra ratio shows that whereas the published data are generally clustered with no obvious correlation, the data from this study have substantially different relationships depending largely on the permeability of the underlying geology. Models for the relatively impermeable geological units plot parallel to the average indoor radon: soil ²²?Ra model but with lower indoor radon: soil ²²?Ra ratios, whilst the models for the permeable geological units plot parallel to the average indoor radon: soil ²²?Ra model but with higher than average indoor radon: soil ²²?Ra ratios. PMID:20951477

Appleton, J D; Cave, M R; Miles, J C H; Sumerling, T J

2010-10-15

432

The simultaneous separation and determination of chloropropanols in soy sauce and other flavoring with gas chromatography-mass spectrometry in negative chemical and electron impact ionization modes  

Microsoft Academic Search

Both gas chromatography-mass spectrometry in electron ionization (GC-MS-EI) and negative chemical ionization (GC-MS-NCI) modes are reported in this paper for the simultaneous determination of 1,3-dichloropropan-2-ol (1,3-DCP), 2,3-dichloropropan-1-ol (2,3-DCP), 3-chloropropane-1,2-diol (3-MCPD) and 2-chloropropane-1,3-diol (2-MCPD) in soy sauce and other flavoring. D5-3-MCPD (for 3-MCPD and 2-MCPD) and d5-1,3-DCP (for 1,3-DCP and 2,3-DCP) were used as the deuterium isotopic labelled internal standards. The

Xiaomin Xu; Yiping Ren; Pinggu Wu; Jianlong Han; Xianghong Shen

2006-01-01

433

Natural Gas and the Transformation of the U.S. Energy Sector: A Program Studying Multi-sector Opportunities and Impacts  

SciTech Connect

In recognition of the major transitions occurring within the U.S. energy economy, the Joint Institute for Strategic Energy Analysis (JISEA) and Stanford University's Precourt Institute for Energy (PIE) engaged energy system stakeholders from government, industry, academia, and the environmental community in a discussion about the priority issues for a program of rigorous research relating to natural gas. Held December 10-11, 2012 on the Golden, CO campus of the National Renewable Energy Laboratory, the workshop provided invited experts opportunity to describe the state of current knowledge in defined topic areas, and to suggest analytic priorities for that topic area. Following discussion, all stakeholders then contributed potential research questions for each topic, and then determined priorities through an interactive voting process. This record of proceedings focuses on the outcomes of the discussion.

Gossett, S.

2013-01-01

434

Acid-catalyzed condensed-phase reactions of limonene and terpineol and their impacts on gas-to-particle partitioning in the formation of organic aerosols.  

PubMed

We investigated the condensed-phase reactions of biogenic VOCs with C double bond C bonds (limonene, C(10)H(16), and terpineol, C(10)H(18)O) catalyzed by sulfuric acid by both bulk solution (BS) experiments and gas-particle (GP) experiments using a flow cell reactor. Product analysis by gas chromatography-mass spectrometry (GC-MS) showed that cationic polymerization led to dimeric and trimeric product formation under conditions of relative humidity (RH) <20% (in the GP experiments) and a sulfuric acid concentration of 57.8 wt % (in the BS experiments), while hydration occurred under conditions of RH > 20% (in the GP experiments) and sulfuric acid concentrations of 46.3 wt % or lower (in the BS experiments). Apparent partitioning coefficients (K(p,rxn)) were estimated from the GP experiments by including the reaction products. Only under extremely low RH conditions (RH < 5%) did the values of K(p,rxn) ( approximately 5 x 10(-6) m(3)/microg for limonene and approximately 2 x 10(-5) m(3)/microg for terpineol) substantially exceed the physical partitioning coefficients (K(p) = 6.5 x 10(-8) m(3)/microg for limonene and =2.3 x 10(-6) m(3)/microg for terpineol) derived from the absorptive partitioning theory. At RH higher than 5%, the apparent partitioning coefficients (K(p,rxn)) of both limonene and terpineol were in the same order of magnitude as the K(p) values derived from the absorptive partitioning theory. Compared with other conditions including VOC concentration and degree of neutralization (by ammonium) of acidic particles, RH is a critical parameter that influences both the reaction mechanisms and the uptake ability (K(p,rxn) values) of these processes. The finding suggests that RH needs to be considered when taking the effects of acid-catalyzed reactions into account in estimating organic aerosol formation from C double bond C containing VOCs. PMID:20550185

Li, Yong Jie; Cheong, Gema Y L; Lau, Arthur P S; Chan, Chak K

2010-07-15

435

Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017. Western Planning Area Lease Sales 229, 233, 238, 246, and 248. Central Planning Area Lease Sales 227, 231, 235, 241, and 247. Draft Environmental Impact Statement. Volume 1: Chapters 1-4.1.  

National Technical Information Service (NTIS)

This Draft Environmental Impact Statement (EIS) covers the proposed 2012-2017 Gulf of Mexicos Western Planning Area and Central Planning Area OCS oil and gas lease sales. The proposed Western Planning Area lease sales are Lease Sale 229 in 2012, Lease Sal...

2011-01-01

436

Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017. Western Planning Area Lease Sales 229, 233, 238, 246, and 248. Central Planning Area Lease Sales 227, 231, 235, 241, and 247. Draft Environmental Impact Statement. Volume 2: Chapters 4.2-8 and Keyword Index.  

National Technical Information Service (NTIS)

This Draft Environmental Impact Statement (EIS) covers the proposed 2012-2017 Gulf of Mexicos Western Planning Area and Central Planning Area OCS oil and gas lease sales. The proposed Western Planning Area lease sales are Lease Sale 229 in 2012, Lease Sal...

2011-01-01

437

Structural determination of zinc dithiophosphates in lubricating oils by gas chromatography-mass spectrometry with electron impact and electron-capture negative ion chemical ionization.  

PubMed

Pentafluorobenzyl ester derivatives were used to identify zinc dialkyldithiophosphates and diaryldithiophosphates antiwear engine oil additives by GC-electron impact ionization (EI) MS and GC-electron-capture negative ion chemical ionization (ECNCI) MS analysis. GC-EI-MS of the dialkyldithiophosphate-pentafluorobenzyl derivatives afforded characteristic fragment ions corresponding to the cleavage of one and two alkyl radicals. In most cases, information was only obtained on one alkyl chain. Additional and complete information was obtained with retention time indices using synthetic derivatives and with GC-ECNCI-MS analysis. ECNCI afforded characteristic dithiophosphate anions which allowed the determination of the total number of carbon atoms in the alkyl radicals. The diastereoisomer mixtures of 2-hydroxy-sec.-alkyl radicals were completely separated on GC analysis. PMID:11206788

Becchi, M; Perret, F; Carraze, B; Beziau, J F; Michel, J P

2001-01-01

438

Study to gauge impact of technology advances  

SciTech Connect

The Gas Research Institute, as part of its Future Gas Resource Evaluation project, is studying the impact of technology advances on maintaining domestic gas supplies. The purpose of this work is to allow research funding to be focused on technologies that will be most instrumental in the short to medium term in converting gas resources to production. By identifying current technologies and their impact, the stage will be set for the identification of future technological needs and R and D issues that will be important to future resource development. GRI has selected the Scotia Group to perform an analysis of the impact of various technologies on proving up gas reserves on a play level in the Gulf Coast (onshore and offshore) area. This area was chosen since it currently accounts for more than 60% of domestic gas production and gas reserves additions. Within the time horizon of the study, this locus of gas production is unlikely to change substantially.

Caldwell, R.H.; Merkel, J.L. [Scotia Group, Dallas, TX (United States); Hansen, J. [Gas Research Inst., Chicago, IL (United States)