Organic Rankine cycle saves energy and reduces gas emissions for cement production

International Nuclear Information System (INIS)

Wang, Huarong; Xu, Jinliang; Yang, Xufei; Miao, Zheng; Yu, Chao

2015-01-01

We investigated ORCs (organic Rankine cycles) integrated with typical China cement production line. The dry air at the kiln cooler outlet with the temperature of 220 °C was the waste heat. The fluids of hexane, isohexane, R601, R123 and R245fa were selected for ORCs based on the critical temperature criterion. The developed ORC verified the thermodynamics analysis. The NPV (net present value) and PBP (payback period) methods were applied to evaluate the economic performance. The LCA (life cycle assessment) was applied to evaluate the environment impacts. ORCs could generate 67,85,540–81,21,650 kWh electricity per year, equivalent to save 2035–2436 tons standard coal and reduce 7743–9268 tons CO 2 emission, for a 4000 t/d cement production line. ORCs reduced gas emissions of CO 2 by 0.62–0.74%, SO 2 by 3.83–4.59% and NO x by 1.36–1.63%. The PBP (payback period) was 2.74–3.42 years. The ORCs had the reduction ratios of EIL (environment impact load) by 1.49–1.83%, GWP (global warming potential) by 0.74–0.92%, AP (acidification potential) by 2.34–2.84%, EP (eutrophication potential) by 0.96–1.22% and HTP (human toxicity potential) by 2.38–2.89%. The ORC with R601 as the fluid had the best economic performance and significant gas emission reductions. ORCs had good economic performance and reduce the gas emissions. - Highlights: • Organic Rankine Cycles were integrated with the cement production line. • Five organic fluids were used as the working fluids for ORCs. • Thermal, economic and gas emission performances were analyzed. • R601 was the best fluid for ORC with the heat source temperature of 220 °C. • ORCs had good economic and gas emission reduction performances

Database of emission lines

Science.gov (United States)

Binette, L.; Ortiz, P.; Joguet, B.; Rola, C.

1998-11-01

A widely accessible data bank (available through Netscape) and consiting of all (or most) of the emission lines reported in the litterature is being built. It will comprise objects as diverse as HII regions, PN, AGN, HHO. One of its use will be to define/refine existing diagnostic emission line diagrams.

THE HERSCHEL COMPREHENSIVE (U)LIRG EMISSION SURVEY (HERCULES): CO LADDERS, FINE STRUCTURE LINES, AND NEUTRAL GAS COOLING

Energy Technology Data Exchange (ETDEWEB)

Rosenberg, M. J. F.; Van der Werf, P. P.; Israel, F. P.; Meijerink, R. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Aalto, S. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Observatory, SE-43994 Onsala (Sweden); Armus, L.; Díaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Charmandaris, V. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, P. Penteli, 15236 Athens (Greece); Evans, A. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Ave SW, Washington, DC 20375 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences (CAS), 2 West Beijing Road, Nanjing 210008 (China); González-Alfonso, E. [Departamento de Fsica y Matemáticas, Universidad de Alcalá, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Harris, A. I. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Henkel, C. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 16, Bonn, D-53121 (Germany); Isaak, K. G. [Scientific Support Office, ESTEC/SRE-S, Keplerlaan 1, NL-2201 AZ Noordwijk (Netherlands); Kramer, C., E-mail: rosenberg@strw.leidenuniv.nl [Instituto Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Nucleo Central, E-18012 Granada (Spain); and others

2015-03-10

(Ultra) luminous infrared galaxies ((U)LIRGs) are objects characterized by their extreme infrared (8-1000 μm) luminosities (L {sub LIRG} > 10{sup 11} L {sub ☉} and L {sub ULIRG} > 10{sup 12} L {sub ☉}). The Herschel Comprehensive ULIRG Emission Survey (PI: van der Werf) presents a representative flux-limited sample of 29 (U)LIRGs that spans the full luminosity range of these objects (10{sup 11} L {sub ☉} ≤ L {sub IR} ≤ 10{sup 13} L {sub ☉}). With the Herschel Space Observatory, we observe [C II] 157 μm, [O I] 63 μm, and [O I] 145 μm line emission with Photodetector Array Camera and Spectrometer, CO J = 4-3 through J = 13-12, [C I] 370 μm, and [C I] 609 μm with SPIRE, and low-J CO transitions with ground-based telescopes. The CO ladders of the sample are separated into three classes based on their excitation level. In 13 of the galaxies, the [O I] 63 μm emission line is self absorbed. Comparing the CO excitation to the InfraRed Astronomical Satellite 60/100 μm ratio and to far infrared luminosity, we find that the CO excitation is more correlated to the far infrared colors. We present cooling budgets for the galaxies and find fine-structure line flux deficits in the [C II], [Si II], [O I], and [C I] lines in the objects with the highest far IR fluxes, but do not observe this for CO 4 ≤ J {sub upp} ≤ 13. In order to study the heating of the molecular gas, we present a combination of three diagnostic quantities to help determine the dominant heating source. Using the CO excitation, the CO J = 1-0 linewidth, and the active galactic nucleus (AGN) contribution, we conclude that galaxies with large CO linewidths always have high-excitation CO ladders, and often low AGN contributions, suggesting that mechanical heating is important.

OXYGEN METALLICITY DETERMINATIONS FROM OPTICAL EMISSION LINES IN EARLY-TYPE GALAXIES

International Nuclear Information System (INIS)

Athey, Alex E.; Bregman, Joel N.

2009-01-01

We measured the oxygen abundances of the warm (T ∼ 10 4 K) phase of gas in seven early-type galaxies through long-slit observations. A template spectra was constructed from galaxies void of warm gas and subtracted from the emission-line galaxies, allowing for a clean measurement of the nebular lines. The ratios of the emission lines are consistent with photoionization, which likely originates from the ultraviolet flux of postasymototic giant branch stars. We employ H II region photoionization models to determine a mean oxygen metallicity of 1.01 ± 0.50 solar for the warm interstellar medium (ISM) in this sample. This warm ISM 0.5-1.5 solar metallicity is consistent with modern determinations of the metallicity in the hot (T ∼ 10 6 -10 7 K) ISM and the upper range of this warm ISM metallicity is consistent with stellar population metallicity determinations. A solar metallicity of the warm ISM favors an internal origin for the warm ISM such as asymptotic giant branch mass loss within the galaxy.

Selective excitation of singly-ionized silver emission lines by Grimm glow discharge plasmas using several different plasma gases

International Nuclear Information System (INIS)

Wagatsuma, K.

1996-01-01

The relative intensities of silver emission lines from Grimm glow discharge plasmas were investigated in the wavelength range from 160 to 600 nm when using different plasma gases. It was characteristic of the plasma excitation that the spectral patterns were strongly dependent on the nature of the plasma gas employed. Intense emission lines of silver ion were observed when argon-helium mixed gases were employed as the plasma gas. Selective excitation of the ionic lines could be principally attributed to the charge transfer collisions between silver atoms and helium ions. (orig.)

Structure, shape, and evolution of radiatively accelerated QSO emission-line clouds

International Nuclear Information System (INIS)

Blumenthal, G.R.; Mathews, W.G.

1979-01-01

The possibility that the broad emission-line regions of QSOs and active galactic nuclei are formed by a multitude of small clouds which are radiatively accelerated is discussed. Although this model is by no means certain at present, it has four virtues: (1) Observed emission-line widths can be produced with observationally allowed electron densities, UV luminosities, and ionization levels. (2) The acceleration force is coherent in each cloud are found. (3) Reasonable line profiles can result for all emission lines. (4) Photoionization of hydrogen accounts for both heating and acceleration of the emission-line gas. A self-consistent model is developed for the structure, shape, and evolution of radiatively accelerated clouds. The shape varies with cloud mass, and two distinct types of clouds. Fully ionized clouds of very low mass approach a nearly spherical shape. However, all clouds having masses greater than some critical mass adopt a ''pancake'' shape. The condition for constant cloud mass in the cloud frame is shown to be equivalent to the equation of motion of a cloud in the rest frame of the QSO. The emission-line profiles can be sensitive to radial variations in the properties of the intercloud medium, and those properties that correspond to observed profiles are discussed. Finally, the covering factor of a system of pancake clouds is estimated along with the total number of clouds required--approximately 10 14 clouds in each QSO

A photoionization model for the optical line emission from cooling flows

Science.gov (United States)

Donahue, Megan; Voit, G. M.

1991-01-01

The detailed predictions of a photoionization model previously outlined in Voit and Donahue (1990) to explain the optical line emission associated with cooling flows in X-ray emitting clusters of galaxies are presented. In this model, EUV/soft X-ray radiation from condensing gas photoionizes clouds that have already cooled. The energetics and specific consequences of such a model, as compared to other models put forth in the literature is discussed. Also discussed are the consequences of magnetic fields and cloud-cloud shielding. The results illustrate how varying the individual column densities of the ionized clouds can reproduce the range of line ratios observed and strongly suggest that the emission-line nebulae are self-irradiated condensing regions at the centers of cooling flows.

Estimation of methane emission from California natural gas industry.

Science.gov (United States)

Kuo, Jeff; Hicks, Travis C; Drake, Brian; Chan, Tat Fu

2015-07-01

Energy generation and consumption are the main contributors to greenhouse gases emissions in California. Natural gas is one of the primary sources of energy in California. A study was recently conducted to develop current, reliable, and California-specific source emission factors (EFs) that could be used to establish a more accurate methane emission inventory for the California natural gas industry. Twenty-five natural gas facilities were surveyed; the surveyed equipment included wellheads (172), separators (131), dehydrators (17), piping segments (145), compressors (66), pneumatic devices (374), metering and regulating (M&R) stations (19), hatches (34), pumps (2), and customer meters (12). In total, 92,157 components were screened, including flanges (10,101), manual valves (10,765), open-ended lines (384), pressure relief valves (358), regulators (930), seals (146), threaded connections (57,061), and welded connections (12,274). Screening values (SVs) were measured using portable monitoring instruments, and Hi-Flow samplers were then used to quantify fugitive emission rates. For a given SV range, the measured leak rates might span several orders of magnitude. The correlation equations between the leak rates and SVs were derived. All the component leakage rate histograms appeared to have the same trend, with the majority of leakage ratesGas Research Institute (EPA/GRI) study. Twenty-five natural gas facilities in California were surveyed to develop current, reliable, and California-specific source emission factors (EFs) for the natural gas industry. Screening values were measured by using portable monitoring instruments, and Hi-Flow samplers were then used to quantify fugitive emission rates. The component-level average EFs derived in this study are often smaller than the corresponding ones in the 1996 EPA/GRI study. The smaller EF values from this study might be partially attributable to the employment of the leak detection and repair program by most, if not all

Flue gas emissions from gas-fired cogeneration units <25 MWe

International Nuclear Information System (INIS)

Nielsen, M.; Wit, J. de

1997-01-01

A total of 900 MW e gas driven combined heat and power (CHP) has now been established in Denmark based on gas engines and gas turbine units less than 25 MW e each. Of the 900 MW e approx. 750 MW e are based on gas engines. Biogas is used as fuel for some 32 MW e of these. Emission limits for NO x and CO are 650 mg/nm 3 (ref. 5% O 2 and electrical efficiency 30% LCV). There is at present no limit for unburned hydrocarbons (UHC) for gas engines or gas turbines. The average emission of unburned hydrocarbons for the Danish gas engine driven CHP units is equal to approx. 3,5% of the fuel used. It is the target of this report to provide the basis for evaluating the planned UHC limit and possible adjustments of the present limit for NO x emission. The average NO x emission from gas turbines slightly exceeds the NO x emission from gas engines. This is due to a number of older gas turbines. Modern gas turbines can achieve significantly lower NO x emission compared to engines. The NO x emission from biogas driven engines is significantly higher than that of natural gas driven units. This is mainly due to NO x -unfavourable engine settings and the use of older units, as there are no legislation concerning NO x emission for the majority of these biogas driven units. The emission of CO and UHC is lower from gas turbines than from gas engines. The NO x emission can be reduced by SCR Catalyst systems. In Denmark 3 gas engine installations use this commercially available technology. Oxidation catalyst for UHC reduction at modern gas engine installations has proven relatively unsuccesful in Denmark until now. Only limited reductions are achieved and many catalysts are toxificated in less than 100 hours of operation. However, long-term field testing of promising UHC reducing catalysts is now being made. UHC reduction by incineration is at the prototype stage. No such plant has yet been set up in Denmark. (Abstract Truncated)

Shale gas production: potential versus actual greenhouse gas emissions

OpenAIRE

O'Sullivan, Francis Martin; Paltsev, Sergey

2012-01-01

Estimates of greenhouse gas (GHG) emissions from shale gas production and use are controversial. Here we assess the level of GHG emissions from shale gas well hydraulic fracturing operations in the United States during 2010. Data from each of the approximately 4000 horizontal shale gas wells brought online that year are used to show that about 900 Gg CH[subscript 4] of potential fugitive emissions were generated by these operations, or 228 Mg CH[subscript 4] per well—a figure inappropriately ...

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

International Nuclear Information System (INIS)

Lenox, Carol; Kaplan, P. Ozge

2016-01-01

With advances in natural gas extraction technologies, there is an increase in the availability of domestic natural gas, and natural gas is gaining a larger share of use as a fuel in electricity production. At the power plant, natural gas is a cleaner burning fuel than coal, but uncertainties exist in the amount of methane leakage occurring upstream in the extraction and production of natural gas. At higher leakage levels, the additional methane emissions could offset the carbon dioxide emissions reduction benefit of switching from coal to natural gas. This analysis uses the MARKAL linear optimization model to compare the carbon emissions profiles and system-wide global warming potential of the U.S. energy system over a series of model runs in which the power sector is required to meet a specific carbon dioxide reduction target across a number of scenarios in which the availability of natural gas changes. Scenarios are run with carbon dioxide emissions and a range of upstream methane emission leakage rates from natural gas production along with upstream methane and carbon dioxide emissions associated with production of coal and oil. While the system carbon dioxide emissions are reduced in most scenarios, total carbon dioxide equivalent emissions show an increase in scenarios in which natural gas prices remain low and, simultaneously, methane emissions from natural gas production are higher. - Highlights: • MARKAL analysis of energy system GHG emissions reduction scenarios. • High methane leakage can eliminate the benefit that natural gas brings over coal. • A robust GHG reduction strategy takes into account upstream emissions for all fuels.

The extinction to the H2 line emission in the DR 21 outflow source

International Nuclear Information System (INIS)

Nadeau, D.; Riopel, M.; Geballe, T.R.

1991-01-01

The v = 1-0 S(1) and Q(3) lines of H2 have been measured in four regions of the DR 21 H2 line-emission source, in order to determine whether the observed morphology of the emission represents the distribution of the excited H2 or is modified by nonuniform extinction across the source. The measured lines originate from the same upper level, and their ratio is a direct measure of the reddening. The line ratios show that the extinction is quite uniform across the source and that there is no correlation between the intensity and the extinction. This result implies that the gap between the two lobes of emission is not due to increased extinction but rather is a region where there is little excited H2 gas. 13 refs

ALMA IMAGING OF THE CO (6-5) LINE EMISSION IN NGC 7130

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yinghe [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Lu, Nanyao [National Astronomical Observatories of China, Chinese Academy of Sciences, Beijing 100012 (China); Xu, C. Kevin; Appleton, Philip; Murphy, Eric [Infrared Processing and Analysis Center, California Institute of Technology 100-22, Pasadena, CA 91125 (United States); Gao, Yu [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Barcos-Munõz, Loreto [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Díaz-Santos, Tanio [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Charmandaris, Vassilis [Department of Physics, University of Crete, GR-71003 Heraklion (Greece); Armus, Lee [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Van der Werf, Paul [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Evans, Aaron [National Radio Astronomy Observatory, Charlottesville, VA 22904 (United States); Cao, Chen [School of Space Science and Physics, Shandong University at Weihai, Weihai, Shandong 264209 (China); Inami, Hanae, E-mail: zhaoyinghe@gmail.com [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

2016-04-01

In this paper, we report our high-resolution (0.″20 × 0.″14 or ∼70 × 49 pc) observations of the CO(6-5) line emission, which probes warm and dense molecular gas, and the 434 μm dust continuum in the nuclear region of NGC 7130, obtained with the Atacama Large Millimeter Array (ALMA). The CO line and dust continuum fluxes detected in our ALMA observations are 1230 ± 74 Jy km s{sup −1} and 814 ± 52 mJy, respectively, which account for 100% and 51% of their total fluxes. We find that the CO(6-5) and dust emissions are generally spatially correlated, but their brightest peaks show an offset of ∼70 pc, suggesting that the gas and dust emissions may start decoupling at this physical scale. The brightest peak of the CO(6-5) emission does not spatially correspond to the radio continuum peak, which is likely dominated by an active galactic nucleus (AGN). This, together with our additional quantitative analysis, suggests that the heating contribution of the AGN to the CO(6-5) emission in NGC 7130 is negligible. The CO(6-5) and the extinction-corrected Pa-α maps display striking differences, suggestive of either a breakdown of the correlation between warm dense gas and star formation at linear scales of <100 pc or a large uncertainty in our extinction correction to the observed Pa-α image. Over a larger scale of ∼2.1 kpc, the double-lobed structure found in the CO(6-5) emission agrees well with the dust lanes in the optical/near-infrared images.

ALMA IMAGING OF THE CO (6-5) LINE EMISSION IN NGC 7130

International Nuclear Information System (INIS)

Zhao, Yinghe; Lu, Nanyao; Xu, C. Kevin; Appleton, Philip; Murphy, Eric; Gao, Yu; Barcos-Munõz, Loreto; Díaz-Santos, Tanio; Charmandaris, Vassilis; Armus, Lee; Van der Werf, Paul; Evans, Aaron; Cao, Chen; Inami, Hanae

2016-01-01

In this paper, we report our high-resolution (0.″20 × 0.″14 or ∼70 × 49 pc) observations of the CO(6-5) line emission, which probes warm and dense molecular gas, and the 434 μm dust continuum in the nuclear region of NGC 7130, obtained with the Atacama Large Millimeter Array (ALMA). The CO line and dust continuum fluxes detected in our ALMA observations are 1230 ± 74 Jy km s −1 and 814 ± 52 mJy, respectively, which account for 100% and 51% of their total fluxes. We find that the CO(6-5) and dust emissions are generally spatially correlated, but their brightest peaks show an offset of ∼70 pc, suggesting that the gas and dust emissions may start decoupling at this physical scale. The brightest peak of the CO(6-5) emission does not spatially correspond to the radio continuum peak, which is likely dominated by an active galactic nucleus (AGN). This, together with our additional quantitative analysis, suggests that the heating contribution of the AGN to the CO(6-5) emission in NGC 7130 is negligible. The CO(6-5) and the extinction-corrected Pa-α maps display striking differences, suggestive of either a breakdown of the correlation between warm dense gas and star formation at linear scales of <100 pc or a large uncertainty in our extinction correction to the observed Pa-α image. Over a larger scale of ∼2.1 kpc, the double-lobed structure found in the CO(6-5) emission agrees well with the dust lanes in the optical/near-infrared images

Synthetic nebular emission from massive galaxies - I: origin of the cosmic evolution of optical emission-line ratios

Science.gov (United States)

Hirschmann, Michaela; Charlot, Stephane; Feltre, Anna; Naab, Thorsten; Choi, Ena; Ostriker, Jeremiah P.; Somerville, Rachel S.

2017-12-01

Galaxies occupy different regions of the [O III]λ5007/H β-versus-[N II]λ6584/H α emission-line ratio diagram in the distant and local Universe. We investigate the origin of this intriguing result by modelling self-consistently, for the first time, nebular emission from young stars, accreting black holes (BHs) and older, post-asymptotic giant branch (post-AGB) stellar populations in galaxy formation simulations in a full cosmological context. In post-processing, we couple new-generation nebular-emission models with high-resolution, cosmological zoom-in simulations of massive galaxies to explore which galaxy physical properties drive the redshift evolution of the optical-line ratios [O III]λ5007/H β, [N II]λ6584/H α, [S II]λλ6717, 6731/H α and [O I]λ6300/H α. The line ratios of simulated galaxies agree well with observations of both star-forming and active local Sloan Digital Sky Survey galaxies. Towards higher redshifts, at fixed galaxy stellar mass, the average [O III]/H β is predicted to increase and [N II]/H α, [S II]/H α and [O I]/H α to decrease - widely consistent with observations. At fixed stellar mass, we identify star formation history, which controls nebular emission from young stars via the ionization parameter, as the primary driver of the cosmic evolution of [O III]/H β and [N II]/H α. For [S II]/H α and [O I]/H α, this applies only to redshifts greater than z = 1.5, the evolution at lower redshift being driven in roughly equal parts by nebular emission from active galactic nuclei and post-AGB stellar populations. Instead, changes in the hardness of ionizing radiation, ionized-gas density, the prevalence of BH accretion relative to star formation and the dust-to-metal mass ratio (whose impact on the gas-phase N/O ratio we model at fixed O/H) play at most a minor role in the cosmic evolution of simulated galaxy line ratios.

Constraints on the outer radius of the broad emission line region of active galactic nuclei

Science.gov (United States)

Landt, Hermine; Ward, Martin J.; Elvis, Martin; Karovska, Margarita

2014-03-01

Here we present observational evidence that the broad emission line region (BELR) of active galactic nuclei (AGN) generally has an outer boundary. This was already clear for sources with an obvious transition between the broad and narrow components of their emission lines. We show that the narrow component of the higher-order Paschen lines is absent in all sources, revealing a broad emission line profile with a broad, flat top. This indicates that the BELR is kinematically separate from the narrow emission line region. We use the virial theorem to estimate the BELR outer radius from the flat top width of the unblended profiles of the strongest Paschen lines, Paα and Paβ, and find that it scales with the ionizing continuum luminosity roughly as expected from photoionization theory. The value of the incident continuum photon flux resulting from this relationship corresponds to that required for dust sublimation. A flat-topped broad emission line profile is produced by both a spherical gas distribution in orbital motion and an accretion disc wind if the ratio between the BELR outer and inner radius is assumed to be less than ˜100-200. On the other hand, a pure Keplerian disc can be largely excluded, since for most orientations and radial extents of the disc the emission line profile is double-horned.

Emission profiles of K-He exciplexes in cold helium gas

International Nuclear Information System (INIS)

Allard, N F

2012-01-01

Emission spectra of exciplexes composed of a light alkali atom in the first excited state and 4 He atoms have been observed in cryogenic gas in the spectral range from the atomic D lines to 6300 cm −1 . A unified semi-classical theory of line broadening has been used to determine the total profile from the center to the far wings of emission profiles of potassium perturbed by helium at low temperatures and high He density. The agreement of the theoretical peak positions of K*He n exciplexes compared to the experimental determinations is fairly good. Such comparisons provide a critical test of the calculated molecular potentials and the relevance of the theoretical approach which has been used.

Greenhouse gas emissions increase global warming

OpenAIRE

Mohajan, Haradhan

2011-01-01

This paper discusses the greenhouse gas emissions which cause the global warming in the atmosphere. In the 20th century global climate change becomes more sever which is due to greenhouse gas emissions. According to International Energy Agency data, the USA and China are approximately tied and leading global emitters of greenhouse gas emissions. Together they emit approximately 40% of global CO2 emissions, and about 35% of total greenhouse gases. The developed and developing industrialized co...

Economic growth and greenhouse gas emissions

Energy Technology Data Exchange (ETDEWEB)

Ansuategi, Alberto [Environment Department, University of York, York (United Kingdom); Escapa, Marta [Foundations of Economic Analysis Department, University of the Basque Country, Bilbao (Spain)

2002-01-01

Recent empirical research has examined the relationship between certain indicators of environmental degradation and income, concluding that in some cases an inverted U-shaped relationship, which has been called an environmental Kuznets curve (EKC), exists between these variables. Unfortunately, this inverted U-shaped relationship does not hold for greenhouse gas emissions. One explanation of the absence of EKC-like behavior in greenhouse gas emissions is that greenhouse gases are special pollutants that create global, not local, disutility. But the international nature of global warming is not the only reason that prevents de-linking greenhouse gas emissions from economic growth. The intergenerational nature of the negative impact of greenhouse gas emissions may have also been an important factor preventing the implementation of greenhouse gas abatement measures in the past. In this paper we explore the effect that the presence of intergenerational spillovers has on the emissions-income relationship. We use a numerically calibrated overlapping generations model of climate-economy interactions. We conclude that: (1) the intertemporal responsibility of the regulatory agency, (2) the institutional capacity to make intergenerational transfers and (3) the presence of intergenerationally lagged impact of emissions constitute important determinants of the relationship between economic growth and greenhouse gas emissions.

(Sub)millimeter emission lines of molecules in born-again stars

Science.gov (United States)

Tafoya, D.; Toalá, J. A.; Vlemmings, W. H. T.; Guerrero, M. A.; De Beck, E.; González, M.; Kimeswenger, S.; Zijlstra, A. A.; Sánchez-Monge, Á.; Treviño-Morales, S. P.

2017-04-01

Context. Born-again stars provide a unique possibility to study the evolution of the circumstellar envelope of evolved stars in human timescales. Up until now, most of the observations of the circumstellar material in these stars have been limited to studying the relatively hot gas and dust. In other evolved stars, the emission from rotational transitions of molecules, such as CO, is commonly used to study the cool component of their circumstellar envelopes. Thus, the detection and study of molecular gas in born-again stars is of great importance when attempting to understand their composition and chemical evolution. In addition, the molecular emission is an invaluable tool for exploring the physical conditions, kinematics, and formation of asymmetric structures in the circumstellar envelopes of these evolved stars. However, up until now, all attempts to detect molecular emission from the cool material around born-again stars have failed. Aims: We searched for emission from rotational transitions of molecules in the hydrogen-deficient circumstellar envelopes of born-again stars to explore the chemical composition, kinematics, and physical parameters of the relatively cool gas. Methods: We carried out observations using the APEX and IRAM 30 m telescopes to search for molecular emission toward four well-studied born-again stars, V4334 Sgr, V605 Aql, A30, and A78, that are thought to represent an evolutionary sequence. Results: For the first time, we detected emission from HCN and H13CN molecules toward V4334 Sgr, and CO emission in V605 Aql. No molecular emission was detected above the noise level toward A30 and A78. The detected lines exhibit broad linewidths ≳150 km s-1, which indicates that the emission comes from gas ejected during the born-again event, rather than from the old planetary nebula. A first estimate of the H12CN/H13CN abundance ratio in the circumstellar environment of V4334 Sgr is ≈3, which is similar to the value of the 12C/13C ratio measured

Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

Directory of Open Access Journals (Sweden)

Hery Suyanto

2016-08-01

Full Text Available A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns and picosecond (ps lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS using He ambient gas.

Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

Energy Technology Data Exchange (ETDEWEB)

Suyanto, Hery [Department of Physics, Faculty of Mathematics and Natural Sciences, Udayana University, Kampus Bukit Jimbaran, Denpasar 80361, Bali (Indonesia); Pardede, Marincan [Department of Electrical Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Hedwig, Rinda [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Marpaung, Alion Mangasi [Department of Physics, Faculty of Mathematics and Natural Sciences, Jakarta State University, Rawamangun, Jakarta 12440 (Indonesia); Ramli, Muliadi [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Lie, Tjung Jie; Kurniawan, Koo Hendrik, E-mail: kurnia18@cbn.net.id [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Abdulmadjid, Syahrun Nur [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Tjia, May On [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Physics of Magnetism and Photonics Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha,Bandung 40132 (Indonesia); Kagawa, Kiichiro [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Fukui Science Education Academy, Takagi Chuo 2 chome, Fukui 910-0804 (Japan)

2016-08-15

A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns) and picosecond (ps) lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE) mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS) using He ambient gas.

Remote gas analysis of aircraft exhausts using FTIR-emission-spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Heland, J.; Schaefer, K. [Fraunhofer Inst. for Atmospheric Environmental Research, Garmisch-Partenkirchen (Germany)

1997-12-31

FITR emission spectroscopy as a remote sensing multi-component analyzing technique was investigated to determine the composition of aircraft exhausts at ground level. A multi-layer radiative transfer interpretation software based on a line-by-line computer algorithm using the HITRAN data base was developed. Measurements were carried out with different engine types to determine the traceable gas species and their detection limits. Finally validation measurements were made to compare the results of the system to those of conventional equipment. (author) 8 refs.

Remote gas analysis of aircraft exhausts using FTIR-emission-spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Heland, J; Schaefer, K [Fraunhofer Inst. for Atmospheric Environmental Research, Garmisch-Partenkirchen (Germany)

1998-12-31

FITR emission spectroscopy as a remote sensing multi-component analyzing technique was investigated to determine the composition of aircraft exhausts at ground level. A multi-layer radiative transfer interpretation software based on a line-by-line computer algorithm using the HITRAN data base was developed. Measurements were carried out with different engine types to determine the traceable gas species and their detection limits. Finally validation measurements were made to compare the results of the system to those of conventional equipment. (author) 8 refs.

A Deep Chandra ACIS Study of NGC 4151. II. The Innermost Emission Line Region and Strong Evidence for Radio Jet-NLR Cloud Collision

Science.gov (United States)

Wang, Junfeng; Fabbiano, Giuseppina; Elvis, Martin; Risaliti, Guido; Mundell, Carole G.; Karovska, Margarita; Zezas, Andreas

2011-07-01

We have studied the X-ray emission within the inner ~150 pc radius of NGC 4151 by constructing high spatial resolution emission line images of blended O VII, O VIII, and Ne IX. These maps show extended structures that are spatially correlated with the radio outflow and optical [O III] emission. We find strong evidence for jet-gas cloud interaction, including morphological correspondences with regions of X-ray enhancement, peaks of near-infrared [Fe II] emission, and optical clouds. In these regions, moreover, we find evidence of elevated Ne IX/O VII ratios; the X-ray emission of these regions also exceeds that expected from nuclear photoionization. Spectral fitting reveals the presence of a collisionally ionized component. The thermal energy of the hot gas suggests that >~ 0.1% of the estimated jet power is deposited into the host interstellar medium through interaction between the radio jet and the dense medium of the circumnuclear region. We find possible pressure equilibrium between the collisionally ionized hot gas and the photoionized line-emitting cool clouds. We also obtain constraints on the extended iron and silicon fluorescent emission. Both lines are spatially unresolved. The upper limit on the contribution of an extended emission region to the Fe Kα emission is <~ 5% of the total, in disagreement with a previous claim that 65% of the Fe Kα emission originates in the extended narrow line region.

The nature of extreme emission line galaxies at z = 1-2: kinematics and metallicities from near-infrared spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Maseda, Michael V.; Van der Wel, Arjen; Rix, Hans-Walter; Da Cunha, Elisabete; Meidt, Sharon E. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Pacifici, Camilla [Yonsei University Observatory, Yonsei University, Seoul 120-749 (Korea, Republic of); Momcheva, Ivelina; Van Dokkum, Pieter; Nelson, Erica J. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Brammer, Gabriel B.; Ferguson, Henry C.; Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Franx, Marijn; Fumagalli, Mattia [Leiden Observatory, Leiden University, Leiden (Netherlands); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Förster-Schreiber, Natascha M. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Koo, David C. [UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Lundgren, Britt F. [Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706 (United States); Marchesini, Danilo [Physics and Astronomy Department, Tufts University, Robinson Hall, Room 257, Medford, MA 02155 (United States); Patel, Shannon G., E-mail: maseda@mpia.de [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); and others

2014-08-10

We present near-infrared spectroscopy of a sample of 22 Extreme Emission Line Galaxies at redshifts 1.3 < z < 2.3, confirming that these are low-mass (M{sub *} = 10{sup 8}-10{sup 9} M{sub ☉}) galaxies undergoing intense starburst episodes (M{sub *}/SFR ∼ 10-100 Myr). The sample is selected by [O III] or Hα emission line flux and equivalent width using near-infrared grism spectroscopy from the 3D-HST survey. High-resolution NIR spectroscopy is obtained with LBT/LUCI and VLT/X-SHOOTER. The [O III]/Hβ line ratio is high (≳ 5) and [N II]/Hα is always significantly below unity, which suggests a low gas-phase metallicity. We are able to determine gas-phase metallicities for seven of our objects using various strong-line methods, with values in the range 0.05-0.30 Z{sub ☉} and with a median of 0.15 Z{sub ☉}; for three of these objects we detect [O III] λ4363, which allows for a direct constraint on the metallicity. The velocity dispersion, as measured from the nebular emission lines, is typically ∼50 km s{sup –1}. Combined with the observed star-forming activity, the Jeans and Toomre stability criteria imply that the gas fraction must be large (f{sub gas} ≳ 2/3), consistent with the difference between our dynamical and stellar mass estimates. The implied gas depletion timescale (several hundred Myr) is substantially longer than the inferred mass-weighted ages (∼50 Myr), which further supports the emerging picture that most stars in low-mass galaxies form in short, intense bursts of star formation.

observations of hot molecular gas emission from embedded low-mass protostars

DEFF Research Database (Denmark)

Visser, R.; Kristensen, L. E.; Bruderer, S.

2012-01-01

Aims. Young stars interact vigorously with their surroundings, as evident from the highly rotationally excited CO (up to Eu/k = 4000 K) and H2O emission (up to 600 K) detected by the Herschel Space Observatory in embedded low-mass protostars. Our aim is to construct a model that reproduces...... the observations quantitatively, to investigate the origin of the emission, and to use the lines as probes of the various heating mechanisms. Methods. The model consists of a spherical envelope with a power-law density structure and a bipolar outflow cavity. Three heating mechanisms are considered: passive heating...... such as luminosity and envelope mass. Results. The bulk of the gas in the envelope, heated by the protostellar luminosity, accounts for 3–10% of the CO luminosity summed over all rotational lines up to J = 40–39; it is best probed by low-J CO isotopologue lines such as C18O 2–1 and 3–2. The UV-heated gas and the C...

THE IMPORTANCE OF NEBULAR CONTINUUM AND LINE EMISSION IN OBSERVATIONS OF YOUNG MASSIVE STAR CLUSTERS

International Nuclear Information System (INIS)

Reines, Amy E.; Nidever, David L.; Whelan, David G.; Johnson, Kelsey E.

2010-01-01

In this spectroscopic study of infant massive star clusters, we find that continuum emission from ionized gas rivals the stellar luminosity at optical wavelengths. In addition, we find that nebular line emission is significant in many commonly used broadband Hubble Space Telescope (HST) filters including the F814W I-band, the F555W V-band, and the F435W B-band. Two young massive clusters (YMCs) in the nearby starburst galaxy NGC 4449 were targeted for follow-up spectroscopic observations after Reines et al. discovered an F814W I-band excess in their photometric study of radio-detected clusters in the galaxy. The spectra were obtained with the Dual Imaging Spectrograph (DIS) on the 3.5 m Apache Point Observatory (APO) telescope and have a spectral range of ∼3800-9800 A. We supplement these data with HST and Sloan Digital Sky Survey photometry of the clusters. By comparing our data to the Starburst99 and GALEV evolutionary synthesis models, we find that nebular continuum emission competes with the stellar light in our observations and that the relative contribution from the nebular continuum is largest in the U- and I-bands, where the Balmer (3646 A) and Paschen jumps (8207 A) are located. The spectra also exhibit strong line emission including the [S III] λλ9069, 9532 lines in the HST F814W I-band. We find that the combination of nebular continuum and line emission can account for the F814W I-band excess previously found by Reines et al. In an effort to provide a benchmark for estimating the impact of ionized gas emission on photometric observations of young massive stellar populations, we compute the relative contributions of the stellar continuum, nebular continuum, and emission lines to the total observed flux of a 3 Myr old cluster through various HST filter/instrument combinations, including filters in the Wide Field Camera 3. We urge caution when comparing observations of YMCs to evolutionary synthesis models since nebular continuum and line emission can

National Greenhouse Gas Emission Inventory

Data.gov (United States)

U.S. Environmental Protection Agency — The National Greenhouse Gas Emission Inventory contains information on direct emissions of greenhouse gases as well as indirect or potential emissions of greenhouse...

Correction of UBV Photometry for Emission Lines

Directory of Open Access Journals (Sweden)

Skopal A.

2003-12-01

Full Text Available We investigate the effect on U,B,V magnitudes of the removal of emission lines from the spectra of some symbiotic stars and novae during their nebular phases. We approach this problem by the precise reconstruction of the composite UV/optical continuum and the line spectrum. The corrections ΔU, ΔB and ΔV are determined from the ratio of fluxes with and without emission lines. We demonstrate the effect for symbiotic nova V1016 Cyg during its nebular phase. We find that about 68%, 78% and 66% of the observed flux in the U, B and V filters is radiated in the emission lines. The effect should be taken into account before using the observed color indices of emission-line objects for diagnosis of their radiation in the continuum.

The [CII] 158 μm line emission in high-redshift galaxies

Science.gov (United States)

Lagache, G.; Cousin, M.; Chatzikos, M.

2018-02-01

Gas is a crucial component of galaxies, providing the fuel to form stars, and it is impossible to understand the evolution of galaxies without knowing their gas properties. The [CII] fine structure transition at 158 μm is the dominant cooling line of cool interstellar gas, and is the brightest of emission lines from star forming galaxies from FIR through metre wavelengths, almost unaffected by attenuation. With the advent of ALMA and NOEMA, capable of detecting [CII]-line emission in high-redshift galaxies, there has been a growing interest in using the [CII] line as a probe of the physical conditions of the gas in galaxies, and as a star formation rate (SFR) indicator at z ≥ 4. In this paper, we have used a semi-analytical model of galaxy evolution (G.A.S.) combined with the photoionisation code CLOUDY to predict the [CII] luminosity of a large number of galaxies (25 000 at z ≃ 5) at 4 ≤ z ≤ 8. We assumed that the [CII]-line emission originates from photo-dominated regions. At such high redshift, the CMB represents a strong background and we discuss its effects on the luminosity of the [CII] line. We studied the L[CII ]-SFR and L[ CII ]-Zg relations and show that they do not strongly evolve with redshift from z = 4 and to z = 8. Galaxies with higher [CII] luminosities tend to have higher metallicities and higher SFRs but the correlations are very broad, with a scatter of about 0.5 and 0.8 dex for L[ CII ]-SFR and L[ CII ]-Zg, respectively. Our model reproduces the L[ CII ]-SFR relations observed in high-redshift star-forming galaxies, with [CII] luminosities lower than expected from local L[ CII ]-SFR relations. Accordingly, the local observed L[ CII ]-SFR relation does not apply at high-z (z ≳ 5), even when CMB effects are ignored. Our model naturally produces the [CII] deficit (i.e. the decrease of L[ CII ]/LIR with LIR), which appears to be strongly correlated with the intensity of the radiation field in our simulated galaxies. We then predict the

MICROLENSING OF QUASAR BROAD EMISSION LINES: CONSTRAINTS ON BROAD LINE REGION SIZE

Energy Technology Data Exchange (ETDEWEB)

Guerras, E.; Mediavilla, E. [Instituto de Astrofisica de Canarias, Via Lactea S/N, La Laguna E-38200, Tenerife (Spain); Jimenez-Vicente, J. [Departamento de Fisica Teorica y del Cosmos, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada (Spain); Kochanek, C. S. [Department of Astronomy and the Center for Cosmology and Astroparticle Physics, The Ohio State University, 4055 McPherson Lab, 140 West 18th Avenue, Columbus, OH 43221 (United States); Munoz, J. A. [Departamento de Astronomia y Astrofisica, Universidad de Valencia, E-46100 Burjassot, Valencia (Spain); Falco, E. [Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Motta, V. [Departamento de Fisica y Astronomia, Universidad de Valparaiso, Avda. Gran Bretana 1111, Valparaiso (Chile)

2013-02-20

We measure the differential microlensing of the broad emission lines between 18 quasar image pairs in 16 gravitational lenses. We find that the broad emission lines are in general weakly microlensed. The results show, at a modest level of confidence (1.8{sigma}), that high ionization lines such as C IV are more strongly microlensed than low ionization lines such as H{beta}, indicating that the high ionization line emission regions are more compact. If we statistically model the distribution of microlensing magnifications, we obtain estimates for the broad line region size of r{sub s} = 24{sup +22} {sub -15} and r{sub s} = 55{sup +150} {sub -35} lt-day (90% confidence) for the high and low ionization lines, respectively. When the samples are divided into higher and lower luminosity quasars, we find that the line emission regions of more luminous quasars are larger, with a slope consistent with the expected scaling from photoionization models. Our estimates also agree well with the results from local reveberation mapping studies.

UV line emission of symbiotic stars

International Nuclear Information System (INIS)

Nussbaumer, H.

1982-01-01

General characteristics of emission line spectra from symbiotic stars are outlined. Data from some special line ratios in the 1000 A - 3000 A range, and others connecting the visual and the far UV lines are presented, and their application to symbiotic stars is discussed. Integrated fractional abundances for ions easily observed in the far UV are given to facilitate abundance determinations for nebular conditions. It is found that the physical conditions of the regions emitting the emission line spectra differ considerably among different symbiotic stars. (Auth.)

Room chamber assessment of the pollutant emission properties of (nominally) low-emission unflued gas heaters

Energy Technology Data Exchange (ETDEWEB)

Brown, S.K.; Mahoney, K.J., Min Cheng [CSIRO Manufacturing and Infrastructure Technology, Victoria (Australia)

2004-07-01

Pollutant emissions from unflued gas heaters were assessed in CSIRO'a Room Dynamic Environmental Chamber. This paper describes the chamber assessment procedure and presents findings for major commercial heaters that are nominally 'low-emission'. The chamber was operated at controlled conditions of temperature, humidity, ventilation and air mixing, representative of those encountered in typical indoor environments. A fixed rate of heat removal from the chamber air ensured that the heaters operated at constant heating rates, typically {approx}6 MJ/h which simulated operation of a heater after warm-up in an insulated dwelling in south-east Australia. The pollutants assessed were nitrogen dioxide, carbon monoxide, formaldehyde, VOCs and respirable suspended particulates. One type of heater was lower emitting for nigroen dioxide, but emitted greater amounts of carbon monoxide and formaldehyde (the latter becoming significant to indoor air quality). When operated with low line pressure of slight misalignment of the gas burner, this heater became a hazardous source of these pollutants. Emissions from the heates changed little after continous operation for up to 2 months. (au)

A DEEP CHANDRA ACIS STUDY OF NGC 4151. II. THE INNERMOST EMISSION LINE REGION AND STRONG EVIDENCE FOR RADIO JET-NLR CLOUD COLLISION

International Nuclear Information System (INIS)

Wang Junfeng; Fabbiano, Giuseppina; Elvis, Martin; Risaliti, Guido; Karovska, Margarita; Zezas, Andreas; Mundell, Carole G.

2011-01-01

We have studied the X-ray emission within the inner ∼150 pc radius of NGC 4151 by constructing high spatial resolution emission line images of blended O VII, O VIII, and Ne IX. These maps show extended structures that are spatially correlated with the radio outflow and optical [O III] emission. We find strong evidence for jet-gas cloud interaction, including morphological correspondences with regions of X-ray enhancement, peaks of near-infrared [Fe II] emission, and optical clouds. In these regions, moreover, we find evidence of elevated Ne IX/O VII ratios; the X-ray emission of these regions also exceeds that expected from nuclear photoionization. Spectral fitting reveals the presence of a collisionally ionized component. The thermal energy of the hot gas suggests that ∼> 0.1% of the estimated jet power is deposited into the host interstellar medium through interaction between the radio jet and the dense medium of the circumnuclear region. We find possible pressure equilibrium between the collisionally ionized hot gas and the photoionized line-emitting cool clouds. We also obtain constraints on the extended iron and silicon fluorescent emission. Both lines are spatially unresolved. The upper limit on the contribution of an extended emission region to the Fe Kα emission is ∼< 5% of the total, in disagreement with a previous claim that 65% of the Fe Kα emission originates in the extended narrow line region.

Modelling emissions from natural gas flaring

Directory of Open Access Journals (Sweden)

G. Ezaina Umukoro

2017-04-01

Full Text Available The world today recognizes the significance of environmental sustainability to the development of nations. Hence, the role oil and gas industry plays in environmental degrading activities such as gas flaring is of global concern. This study presents material balance equations and predicts results for non-hydrocarbon emissions such as CO2, CO, NO, NO2, and SO2 etc. from flaring (combustion of 12 natural gas samples representing composition of natural gas of global origin. Gaseous emission estimates and pattern were modelled by coding material balance equations for six reaction types and combustion conditions with a computer program. On the average, anticipated gaseous emissions from flaring natural gas with an average annual global flaring rate 126 bcm per year (between 2000 and 2011 in million metric tonnes (mmt are 560 mmt, 48 mmt, 91 mmt, 93 mmt and 50 mmt for CO2, CO, NO, NO2 and SO2 respectively. This model predicted gaseous emissions based on the possible individual combustion types and conditions anticipated in gas flaring operation. It will assist in the effort by environmental agencies and all concerned to track and measure the extent of environmental pollution caused by gas flaring operations in the oil and gas industry.

The Of emission lines near 4650 A

International Nuclear Information System (INIS)

Underhill, A.B.; Gilroy, K.K.; Hill, G.M.

1989-01-01

Rectified, normalized, high S/N intensity tracings of nine Of stars were obtained from Reticon spectra in the 4550-4800-A region. The well-known relatively sharp Of emission lines are seen to stand on pedestals of broad weak emission somewhat like the broad emission lines from WR stars. It is suggested that cascades following dielectronic recombination may be an important process driving some lines of N III, C III, and C IV into the emission of Of stars, and that the sharp Of lines come from plasma that is stationary with respect to the star. The broad emission features show an extensive low-density wind from each star. The results imply that the detection of two, more or less equal, broad jumps in the rest spectra of galaxies at about 4640 and 4686 A is more indicative of Of stars than of WR stars. 32 refs

Agricultural sources of greenhouse gas emissions

International Nuclear Information System (INIS)

Rochette, P.

2003-01-01

The author described different sources of greenhouse gas emissions resulting from agricultural activities and the process by which carbon dioxide, nitrous oxide, and methane are generated on Canadian farms. The author also proposed some practices that would contribute to the reduction of greenhouse gas emissions. A brief description of the greenhouse effect was also provided with special emphasis on the agricultural sector. In 1996, the Canadian agricultural sector was responsible for approximately 10 per cent of greenhouse gas emissions in the country. Given the increase in farm animals and more intensive agricultural activities, it is estimated that greenhouse gas emissions generated by the agricultural sector will increase by 20 per cent by 2010 if current practices remain in effect. The most optimistic scenarios indicate that the agricultural sector could achieve or even exceed Canada's Kyoto Protocol commitments mainly through organic material sequestration in soils. The possibility for farmers to sell greenhouse gas credits could motivate farmers into adopting various practices that reduce emissions of greenhouse gases. However, the author indicated that the best motivation for farmers is the fact that adopting such practices would also lead to more efficient agricultural production. 5 refs., 4 figs

Pyrolysis gas chromatographic atomic emission detection for sediments, coals and other petrochemical precursors

Energy Technology Data Exchange (ETDEWEB)

Seeley, J.A.; Zeng, Y.D.; Uden, P.C.; Eglinton, T.I.; Ericson, I. (Massachusetts University, Amherst, MA (USA). Dept. of Chemistry)

1992-09-01

On-line flash pyrolysis coupled to a capillary gas chromatograph for the characterization of marine sediments, coals and other heterogeneous solid samples is described. A helium microwave-induced plasma is used for chromatographic detection by atomic emission spectrometry. Simultaneous multi-element detection is achieved with a photodiode array detector. The optical path of the gas chromatographic atomic emission detector is purged with helium, allowing simultaneous, sensitive detection of atomic emission from sulfur 181 nm, phosphorous 186 nm, arsenic 189 nm, selenium 196 nm and carbon 193 nm. Several sediment and coal samples have been analysed for their carbon, nitrogen, sulfur, oxygen, phosphorous, arsenic and selenium content. Qualitative information indicating the occurrence and distribution of these elements in the samples can be used to gauge the relative stage of diagenetic evolution of the samples and provide information on their depositional environment. In some instances the chromatographic behaviour of the compounds produced upon pyrolysis is improved through on-line alkylation. This on-line derivatization is achieved by adding liquid reagents to the pyrolysis probe or by adding liquid reagents to the pyrolysis probe or by adding solid reagents either to the solid sample or by packing the reagent in the injection port of the chromatograph.

Extended Emission-Line Regions: Remnants of Quasar Superwinds?

Science.gov (United States)

Fu, Hai; Stockton, Alan

2009-01-01

We give an overview of our recent integral-field-unit spectroscopy of luminous extended emission-line regions (EELRs) around low-redshift quasars, including new observations of five fields. Previous work has shown that the most luminous EELRs are found almost exclusively around steep-spectrum radio-loud quasars, with apparently disordered global velocity fields, and little, if any, morphological correlation with either the host galaxy or the radio structure. Our new observations confirm and expand these results. The EELRs often show some clouds with velocities exceeding 500 km s-1, ranging up to 1100 km s-1, but the velocity dispersions, with few exceptions, are in the 30-100 km s-1 range. Emission-line ratios show that the EELRs are clearly photoionized by the quasars. Masses of the EELRs range up to 1010Msun. Essentially all of the EELRs show relatively low metallicities, and they are associated with quasars that, in contrast to most, show similarly low metallicities in their broad-line regions. The two objects in our sample that do not have classical double-lobed radio morphologies (3C 48, with a compact-steep-spectrum source; Mrk 1014, radio quiet, but with a weak compact-steep-spectrum source) are the only ones that appear to have recent star formation. While some of the less luminous EELRs may have other origins, the most likely explanation for those in our sample is that they are examples of gas swept out of the host galaxy by a large-solid-angle blast wave accompanying the production of the radio jets. The triggering of the quasar activity is almost certainly the result of the merger of a gas-rich galaxy with a massive, gas-poor galaxy hosting the supermassive black hole. Based in part on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the

Greenhouse gas emissions from hydroelectric reservoirs

International Nuclear Information System (INIS)

Rosa, L.P.; Schaeffer, R.

1994-01-01

In a recent paper, Rudd et al. have suggested that, per unit of electrical energy produced, greenhouse-gas emissions from some hydroelectric reservoirs in northern Canada may be comparable to emissions from fossil-fuelled power plants. The purpose of this comment is to elaborate these issues further so as to understand the potential contribution of hydroelectric reservoirs to the greenhouse effect. More than focusing on the total budget of carbon emissions (be they in the form of CH 4 or be they in the form of CO 2 ), this requires an evaluation of the accumulated greenhouse effect of gas emissions from hydroelectric reservoirs and fossil-fuelled power plants. Two issues will be considered: (a) global warming potential (GWP) for CH 4 ; and (b) how greenhouse-gas emissions from hydroelectric power plants stand against emissions from fossil-fuelled power plants with respect to global warming

Air quality and greenhouse gas emissions (Chapter 3)

CSIR Research Space (South Africa)

Winkler, H

2016-01-01

Full Text Available Shale gas development (SGD) presents opportunities and risks with regards to air pollution and greenhouse gas (GHG) emissions. There is a potential opportunity to reduce emissions, if shale gas replaces ‘dirtier’ (more emissions-intensive) fuels...

Reservoir Greenhouse Gas Emissions at Russian HPP

Energy Technology Data Exchange (ETDEWEB)

Fedorov, M. P.; Elistratov, V. V.; Maslikov, V. I.; Sidorenko, G. I.; Chusov, A. N.; Atrashenok, V. P.; Molodtsov, D. V. [St. Petersburg State Polytechnic University (Russian Federation); Savvichev, A. S. [Russian Academy of Sciences, S. N. Vinogradskii Institute of Microbiology (Russian Federation); Zinchenko, A. V. [A. I. Voeikov Main Geophysical Observatory (Russian Federation)

2015-05-15

Studies of greenhouse-gas emissions from the surfaces of the world’s reservoirs, which has demonstrated ambiguity of assessments of the effect of reservoirs on greenhouse-gas emissions to the atmosphere, is analyzed. It is recommended that greenhouse- gas emissions from various reservoirs be assessed by the procedure “GHG Measurement Guidelines for Fresh Water Reservoirs” (2010) for the purpose of creating a data base with results of standardized measurements. Aprogram for research into greenhouse-gas emissions is being developed at the St. Petersburg Polytechnic University in conformity with the IHA procedure at the reservoirs impounded by the Sayano-Shushenskaya and Mainskaya HPP operated by the RusHydro Co.

Assessing the Greenhouse Gas Emissions from Natural Gas Fired Power Plants

Science.gov (United States)

Hajny, K. D.; Shepson, P. B.; Rudek, J.; Stirm, B. H.; Kaeser, R.; Stuff, A. A.

2017-12-01

Natural gas is often discussed as a "bridge fuel" to transition to renewable energy as it only produces 51% the amount of CO2 per unit energy as coal. This, coupled with rapid increases in production fueled by technological advances, has led to a near tripling of natural gas used for electricity generation since 2005. One concern with this idea of a "bridge fuel" is that methane, the primary component of natural gas, is itself a potent greenhouse gas with 28 and 84 times the global warming potential of CO2 based on mass over a 100 and 20 year period, respectively. Studies have estimated that leaks from the point of extraction to end use of 3.2% would offset the climate benefits of natural gas. Previous work from our group saw that 3 combined cycle power plants emitted unburned CH4 from the stacks and leaked additional CH4 from equipment on site, but total loss rates were still less than 2.2%. Using Purdue's Airborne Laboratory for Atmospheric Research (ALAR) we completed additional aircraft based mass balance experiments combined with passes directly over power plant stacks to expand on the previous study. In this work, we have measured at 12 additional natural gas fired power plants including a mix of operation types (baseload, peaking, intermediate) and firing methods (combined cycle, simple thermal, combustion turbine). We have also returned to the 3 plants previously sampled to reinvestigate emissions for each of those, to assess reproducibility of the results. Here we report the comparison of reported continuous emissions monitoring systems (CEMS) data for CO2 to our emission rates calculated from mass balance experiments, as well as a comparison of calculated CH4 emission rates to estimated emission rates based on the EPA emission factor of 1 g CH4/mmbtu natural gas and CEMS reported heat input. We will also discuss emissions from a coal-fired plant which has been sampled by the group in the past and has since converted to natural gas. Lastly, we discuss the

CO Emissions from Gas Engines Operating on Biomass Producer Gas

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper; Jensen, T. K.; Henriksen, Ulrik Birk

2004-01-01

High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. CO emissions from engines operating on biomass producer gases are high, especially at very lean conditions where...

Influence of gas discharge parameters on emissions from a dielectric barrier discharge excited argon excimer lamp

Directory of Open Access Journals (Sweden)

Mike Collier

2011-11-01

Full Text Available A dielectric barrier discharge excited neutral argon (Ar I excimer lamp has been developed and characterised. The aim of this study was to develop an excimer lamp operating at atmospheric pressure that can replace mercury lamps and vacuum equipment used in the sterilisation of medical equipment and in the food industry. The effects of discharge gas pressure, flow rate, excitation frequency and pulse width on the intensity of the Ar I vacuum ultraviolet (VUV emission at 126 nm and near infrared (NIR lines at 750.4 nm and 811.5 nm have been investigated. These three lines were chosen as they represent emissions resulting from de-excitation of excimer states that emit energetic photons with an energy of 9.8 eV. We observed that the intensity of the VUV Ar₂* excimer emission at 126 nm increased with increasing gas pressure, but decreased with increasing excitation pulse frequency and pulse width. In contrast, the intensities of the NIR lines decreased with increasing gas pressure and increased with increasing pulse frequency and pulse width. We have demonstrated that energetic VUV photons of 9.8 eV can be efficiently generated in a dielectric barrier discharge in Ar.

Mid-IR Properties of an Unbiased AGN Sample of the Local Universe. 1; Emission-Line Diagnostics

Science.gov (United States)

Weaver, K. A.; Melendez, M.; Muhotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth. E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.;

QSOs with narrow emission lines

International Nuclear Information System (INIS)

Baldwin, J.A.; Mcmahon, R.; Hazard, C.; Williams, R.E.

1988-01-01

Observations of two new high-redshift, narrow-lined QSOs (NLQSOs) are presented and discussed together with observations of similar objects reported in the literature. Gravitational lensing is ruled out as a possible means of amplifying the luminosity for one of these objects. It is found that the NLQSOs have broad bases on their emission lines as well as the prominent narrow cores which define this class. Thus, these are not pole-on QSOs. The FWHM of the emission lines fits onto the smoothly falling tail of the lower end of the line-width distribution for complete QSO samples. The equivalent widths of the combined broad and narrow components of the lines are normal for QSOs of the luminosity range under study. However, the NLQSOs do show ionization differences from broader-lined QSOs; most significant, the semiforbidden C III/C IV intensity ratio is unusually low. The N/C abundance ratio in these objects is found to be normal; the Al/C abundance ratio may be quite high. 38 references

Emission of Gas and Al2O3 Smoke in Gas-Al Particle Deflagration: Experiments and Emission Modeling for Explosive Fireballs

Science.gov (United States)

Ranc-Darbord, Isabelle; Baudin, Gérard; Genetier, Marc; Ramel, David; Vasseur, Pierre; Legrand, Julien; Pina, Vincent

2018-03-01

Emission of gas and Al2O3 smoke within the deflagration of H2{-}O2-{N2{-}CO2}-Al particles has been studied in a closed combustion chamber at pressures of up to 18 bar and at gas temperatures of up to 3700 K. Measurements of radiance intensity were taken using a five wavelength pyrometer (0.660 μ m, 0.850 μ m, 1.083 μ m, 1.260 μ m, 1.481 μ m) and a grating spectrometer in the range (4.10 μ m to 4.30 μ m). In order to characterize the aluminum oxide smoke size and temperature, an inversion method has been developed based on the radiation transfer equation and using pyrometer measurements and thermochemical calculations of Al2O3 smoke volume fractions. Temperatures in combustion gas have been determined using a method based on the assumed blackbody head of the 4.26 μ m CO2 emission line and on its spectral shift with pressure and temperature. For validation purpose, this method has been applied to measurements obtained when calibrated alumina particles are injected in a combustion chamber prior to gaseous deflagrations. This mathematical inversion method was developed to investigate explosive fireballs.

Towards a comprehensive greenhouse gas emissions inventory for biosolids.

Science.gov (United States)

Alvarez-Gaitan, J P; Short, Michael D; Lundie, Sven; Stuetz, Richard

2016-06-01

Effective handling and treatment of the solids fraction from advanced wastewater treatment operations carries a substantial burden for water utilities relative to the total economic and environmental impacts from modern day wastewater treatment. While good process-level data for a range of wastewater treatment operations are becoming more readily available, there remains a dearth of high quality operational data for solids line processes in particular. This study seeks to address this data gap by presenting a suite of high quality, process-level life cycle inventory data covering a range of solids line wastewater treatment processes, extending from primary treatment through to biosolids reuse in agriculture. Within the study, the impacts of secondary treatment technology and key parameters such as sludge retention time, activated sludge age and primary-to-waste activated sludge ratio (PS:WAS) on the life cycle inventory data of solids processing trains for five model wastewater treatment plant configurations are presented. BioWin(®) models are calibrated with real operational plant data and estimated electricity consumption values were reconciled against overall plant energy consumption. The concept of "representative crop" is also introduced in order to reduce the uncertainty associated with nitrous oxide emissions and soil carbon sequestration offsets under biosolids land application scenarios. Results indicate that both the treatment plant biogas electricity offset and the soil carbon sequestration offset from land-applied biosolids, represent the main greenhouse gas mitigation opportunities. In contrast, fertiliser offsets are of relatively minor importance in terms of the overall life cycle emissions impacts. Results also show that fugitive methane emissions at the plant, as well as nitrous oxide emissions both at the plant and following agricultural application of biosolids, are significant contributors to the overall greenhouse gas balance and combined are

Greenhouse gas emission from Australian coal mining

International Nuclear Information System (INIS)

Williams, D.

1998-01-01

Since 1997, when the Australian Coal Association (ACA) signed a letter of Intent in respect of the governments Greenhouse Challenge Program, it has encouraged its member companies to participate. Earlier this year, the ACA commissioned an independent scoping study on greenhouse gas emissions in the black coal mining industry This was to provide background information, including identification of information gaps and R and D needs, to guide the formulation of a strategy for the mitigation of greenhouse gas emissions associated with the mining, processing and handling of black coals in Australia. A first step in the process of reducing emission levels is an appreciation of the source, quantity and type of emissions om nine sites. It is shown that greenhouse gas emissions on mine sites come from five sources: energy consumption during mining activities, the coal seam gas liberated due to the extraction process i.e. fugitive emissions, oxidation of carbonaceous wastes, land use, and embodied energy. Also listed are indications of the degree of uncertainty associated with each of the estimates

Does Increased Extraction of Natural Gas Reduce Carbon Emissions?

International Nuclear Information System (INIS)

Aune, F.R.; Golombek, R.; Kittelsen, S.A. C.

2004-01-01

Without an international climate agreement, extraction of more natural gas could reduce emissions of CO2 as more 'clean' natural gas may drive out ''dirty'' coal and oil. Using a computable equilibrium model for the Western European electricity and natural gas markets, we examine whether increased extraction of natural gas in Norway reduces global emissions of CO2. We find that both in the short run and in the long run total emissions are reduced if the additional quantity of natural gas is used in gas power production in Norway. If instead the additional quantity is exported directly, total emissions increase both in the short run and in the long run. However, if modest CO2-taxes are imposed, increased extraction of natural gas will reduce CO2 emissions also when the additional natural gas is exported directed

Imaging spectrophotometry of ionized gas in NGC 1068. I - Kinematics of the narrow-line region

Science.gov (United States)

Cecil, Gerald; Bland, Jonathan; Tully, R. Brent

1990-01-01

The kinematics of collisionally excited forbidden N II 6548, 6583 across the inner 1 arcmin diameter of the nearby Seyfert galaxy NGC 1068 is mapped using an imaging Fabry-Perot interferometer and low-noise CCD. The stack of monochromatic images, which spatially resolved the high-velocity gas, was analyzed for kinematic and photometric content. Profiles agree well with previous long-slit work, and their complete spatial coverage makes it possible to constrain the gas volume distribution. It is found that the narrow-line region is distributed in a thick center-darkened, line-emitting cylinder that envelopes the collimated radio jet. Three distinct kinematic subsystems, of which the cylinder is composed, are discussed in detail. Detailed behavior of the emission-line profiles, at the few points in the NE quadrant with simple kinematics, argues that the ionized gas develops a significant component of motion perpendicular to the jet axis.

HIGH-REDSHIFT SDSS QUASARS WITH WEAK EMISSION LINES

International Nuclear Information System (INIS)

Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Jiang Linhua; Kim, J. Serena; Schmidt, Gary D.; Smith, Paul S.; Vestergaard, Marianne; Young, Jason E.; Brandt, W. N.; Shemmer, Ohad; Gibson, Robert R.; Schneider, Donald P.; Strauss, Michael A.; Shen Yue; Anderson, Scott F.; Carilli, Christopher L.; Richards, Gordon T.

2009-01-01

We identify a sample of 74 high-redshift quasars (z > 3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z > 4. These weak emission-line quasars (WLQs) constitute a prominent tail of the Lyα + N v equivalent width distribution, and we compare them to quasars with more typical emission-line properties and to low-redshift active galactic nuclei with weak/absent emission lines, namely BL Lac objects. We find that WLQs exhibit hot (T ∼ 1000 K) thermal dust emission and have rest-frame 0.1-5 μm spectral energy distributions that are quite similar to those of normal quasars. The variability, polarization, and radio properties of WLQs are also different from those of BL Lacs, making continuum boosting by a relativistic jet an unlikely physical interpretation. The most probable scenario for WLQs involves broad-line region properties that are physically distinct from those of normal quasars.

X-ray heating and ionization of broad-emission-line regions in QSO's and active galaxies

International Nuclear Information System (INIS)

Weisheit, J.C.; Shields, G.A.; Tarter, C.B.

1980-07-01

Absorption of x-rays deep within the broad-line emitting clouds in QSO's and the nuclei of active galaxies creates extensive zones of warm (T approx. 10 4 K), partially ionized N/sub e//N approx. 0.1) gas. Because Lyman alpha photons are trapped in these regions, the x-ray energy is efficiently channeled into Balmer lines collisionally excited from the n = 2 level. The HI regions plus the HII regions created by ultraviolet photons illuminating the surfaces of the clouds give rise to integrated Lα/Hα line emission ratios between 1 and 2. Enhanced MgII line emission from the HI regions gives rise to integrated MgII/Hα ratios near 0.5. The OI line lambda 8446 is efficiently pumped by trapped Hα photons and in the x-ray heated zone an intensity ratio I (lambda 8446)/I(Hα) approx. < 0.1 is calculated. All of these computed ratios now are in agreement with observations

NON-DETECTION OF L-BAND LINE EMISSION FROM THE EXOPLANET HD189733b

International Nuclear Information System (INIS)

Mandell, Avi M.; Deming, L. Drake; Mumma, Michael J.; Villanueva, Geronimo L.; Blake, Geoffrey A.; Knutson, Heather A.; Salyk, Colette

2011-01-01

We attempt to confirm bright non-local thermodynamic equilibrium (non-LTE) emission from the exoplanet HD 189733b at 3.25 μm, as recently reported by Swain et al. based on observations at low spectral resolving power (λ/δλ ∼ 30). Non-LTE emission lines from gas in an exoplanet atmosphere will not be significantly broadened by collisions, so the measured emission intensity per resolution element must be substantially brighter when observed at high spectral resolving power. We observed the planet before, during, and after a secondary eclipse event at a resolving power λ/δλ = 27, 000 using the NIRSPEC spectrometer on the Keck II telescope. Our spectra cover a spectral window near the peak found by Swain et al., and we compare emission cases that could account for the magnitude and wavelength dependence of the Swain et al. result with our final spectral residuals. To model the expected line emission, we use a general non-equilibrium formulation to synthesize emission features from all plausible molecules that emit in this spectral region. In every case, we detect no line emission to a high degree of confidence. After considering possible explanations for the Swain et al. results and the disparity with our own data, we conclude that an astrophysical source for the putative non-LTE emission is unlikely. We note that the wavelength dependence of the signal seen by Swain et al. closely matches the 2ν 2 band of water vapor at 300 K, and we suggest that an imperfect correction for telluric water is the source of the feature claimed by Swain et al.

Russians and Ukrainians plan new gas line

International Nuclear Information System (INIS)

TREND

2003-01-01

Paper deals with the building of new gas line between Russia and the Ukraine. In September 2003 Gazprom and Naftohaz Ukraine signed protocol about conditions of Russian gas transit through Ukrainian area for 2004. There is guaranteed quantity of transported gas on the level of 127,8 billions cubic meters by Russian side, 110 billions of it should next lead to Europe. Treaty refills long-term contract between Naftohaz and Gazprom about gas transit through Ukraine for period 2003-2013. Both countries and its companies plan to accept particular capital decision about building of new gas line Novopskov-Uzgorod till end of this year, which will be parallel with gas line Soyuz. It will allow to enlarge transportation system capacity by 28 billion cubic meters. Construction of about 1600 km long ducting system will require 1.6 billion USD by annual capacity about 15 billion cubic meters. If capacity would be doubled by construction of another compressor stations, capital expenses rise to 2.2 billions USD. It can be completely built in 7 years. Its linear part with one compressor can be already built in 3 years. Slovensky Plynarensky Podnik (SPP) would certainly have advantages from possible realisation of new gas line and from consequential transit increase. (Author)

A New Radio Spectral Line Survey of Planetary Nebulae: Exploring Radiatively Driven Heating and Chemistry of Molecular Gas

Science.gov (United States)

Bublitz, Jesse

Planetary nebulae contain shells of cold gas and dust whose heating and chemistry is likely driven by UV and X-ray emission from their central stars and from wind-collision-generated shocks. We present the results of a survey of molecular line emissions in the 88 - 235 GHz range from nine nearby (Radioastronomie Millimetrique. Rotational transitions of nine molecules, including the well-studied CO isotopologues and chemically important trace species, were observed and the results compared with and augmented by previous studies of molecular gas in PNe. Lines of the molecules HCO+, HNC, HCN, and CN, which were detected in most objects, represent new detections for five planetary nebulae in our study. Flux ratios were analyzed to identify correlations between the central star and/or nebular ultraviolet/X-ray luminosities and the molecular chemistries of the nebulae. Analysis reveals the apparent dependence of the HNC/HCN line ratio on PN central star UV luminosity. There exists no such clear correlation between PN X-rays and various diagnostics of PN molecular chemistry. The correlation between HNC/HCN ratio and central star UV luminosity hints at the potential of molecular emission line studies of PNe for improving our understanding of the role that high-energy radiation plays in the heating and chemistry of photodissociation regions.

Variability of Disk Emission in Pre-Main Sequence and Related Stars. II. Variability in the Gas and Dust Emission of the Herbig Fe Star SAO 206462

Science.gov (United States)

Sitko, Michael L.; Day, Amanda N.; Kimes, Robin L.; Beerman, Lori C.; Martus, Cameron; Lynch, David K.; Russell, Ray W.; Grady, Carol A.; Schneider, Glenn; Lisse, Carey M.;

Methane emissions from the natural gas industry

International Nuclear Information System (INIS)

Harrison, M.R.; Cowgill, R.M.; Campbell, L.M.; Lott, R.A.

1993-01-01

The U.S. EPA and the United Nation's Intergovernmental Panel on Climate Change (IPCC) have suggested that global warming could be reduced if more energy was generated using natural gas rather than fuels such as coal. An increased use of natural gas instead of coal would decrease global warming since methane emits less carbon dioxide (CO 2 ) than any fossil fuel. However, methane is a more potent as a greenhouse gas than CO 2 , and leakage from the gas system could reduce or eliminate the inherent advantage of natural gas. For this reason, methane emissions must be quantified before a national policy on preferred fuels is developed. Therefore, GRI and EPA have developed this confunded program to quantify methane emissions from the U.S. gas industry. This paper presents, for general industry review, the approach and methodology that the project is using to determine the emissions. The study will measure or calculate all gas industry methane emissions - from production at the wellhead, through the system, to the customer's meter. When these data are combined with data from other studies, a definitive comparison of the relative environmental impact of using methane versus other fuels will be possible. The study will also provide data that can be used by the industry to identify cost-effective mitigation techniques to reduce losses. The methane emissions project is being conducted in three phases: the first two phases have identified and ranked all known potential methane-emitting sources and established methods for measuring, calculating, and extrapolating emissions from those sources. The third phase, which is currently in progress, will gather sufficient data to achieve the accuracy goal. This paper briefly summarizes the methodology being used for the completion of the third phase

Possibilities of Reducing Greenhouse Gas Emissions in Hotels and Camps Along the Adriatic Coast

International Nuclear Information System (INIS)

Kurek, J.

1998-01-01

The article presents a possibility of reducing greenhouse gas emissions in hotels and camps along the Adriatic Coast, through equipment modernisation, efficient use of various energy forms (electric energy, oil, gas) including solar energy. An elaborate quantitative analysis the greenhouse gas emissions and possible ways of reducing them have been carried out in 180 hotels with their own boiler rooms and 70 camps with solar hot water system. The representatives of the two specified groups were chosen in order to perform the quantitative analysis. Considering that the reduction of the carbon emission is the basic condition for the prevention of climate changes, the assumptions were made in line with their reducing. The starting point is that the combustion of a litre of fuel causes 2,5 kg CO 2 , while the generation of 1 kWh of electric energy and use of 1 m 3 of water emit 0,5 kg of CO 2 respectively. Thereby it is necessary to bear in mind that the reduction of emissions can be achieved directly in hotel boiler rooms and, in a wider perspective, in plants through the reduction of the electric energy and water consumption, i.e. solar energy consumption The article ends with a review of possible emission reductions which are to be carried out. According to the calculation presented, the share of the reduction of greenhouse gas emission in hotels and camps along the Adriatic Coast principate with 1% in the obligatory 5% emission reduction of the Republic of Croatia till the year 2012 related to the Kyoto Protocol. (author)

Suggested guidelines for gas emission monitoring at danish landfills

DEFF Research Database (Denmark)

Kjeldsen, Peter; Scheutz, Charlotte

2015-01-01

Landfill gas is produced on waste disposal sites receiving organic waste resulting in emission of methane. Regulation requires that the landfill gas is managed in order to reduce emissions, but very few suggestions exist to how the landfill gas management activities are monitored, what requirements...... to the ability of the landfill gas management to reduce the emission should be set up, and how criteria are developed for when the monitoring activities can be terminated. Monitoring procedures are suggested centred on a robust method for measuring the total methane emission from the site, and quantitative...

Optical emission line spectra of Seyfert galaxies and radio galaxies

International Nuclear Information System (INIS)

Osterbrock, D.E.

1978-01-01

Many radio galaxies have strong emission lines in their optical spectra, similar to the emission lines in the spectra of Seyfert galaxies. The range of ionization extends from [O I] and [N I] through [Ne V] and [Fe VII] to [Fe X]. The emission-line spectra of radio galaxies divide into two types, narrow-line radio galaxies whose spectra are indistinguishable from Seyfert 2 galaxies, and broad-line radio galaxies whose spectra are similar to Seyfert 1 galaxies. However on the average the broad-line radio galaxies have steeper Balmer decrements, stronger [O III] and weaker Fe II emission than the Seyfert 1 galaxies, though at least one Seyfert 1 galaxy not known to be a radio source has a spectrum very similar to typical broad-line radio galaxies. Intermediate-type Seyfert galaxies exist that show various mixtures of the Seyfert 1 and Seyfert 2 properties, and the narrow-line or Seyfert 2 property seems to be strongly correlated with radio emission. (Auth.)

ORIGIN OF THE GALACTIC DIFFUSE X-RAY EMISSION: IRON K-SHELL LINE DIAGNOSTICS

Energy Technology Data Exchange (ETDEWEB)

Nobukawa, Masayoshi [Department of Teacher Training and School Education, Nara University of Education, Takabatake-cho, Nara, 630-8528 (Japan); Uchiyama, Hideki [Faculty of Education, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529 (Japan); Nobukawa, Kumiko K.; Koyama, Katsuji [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto, 606-8502 (Japan); Yamauchi, Shigeo, E-mail: nobukawa@nara-edu.ac.jp [Department of Physics, Nara Women’s University, Kitauoyanishimachi, Nara, 630-8506 (Japan)

2016-12-20

This paper reports detailed K-shell line profiles of iron (Fe) and nickel (Ni) of the Galactic Center X-ray Emission (GCXE), Galactic Bulge X-ray Emission (GBXE), Galactic Ridge X-ray Emission (GRXE), magnetic Cataclysmic Variables (mCVs), non-magnetic Cataclysmic Variables (non-mCVs), and coronally Active Binaries (ABs). For the study of the origin of the GCXE, GBXE, and GRXE, the spectral analysis is focused on equivalent widths of the Fe i-K α , Fe xxv-He α , and Fe xxvi-Ly α  lines. The global spectrum of the GBXE is reproduced by a combination of the mCVs, non-mCVs, and ABs spectra. On the other hand, the GRXE spectrum shows significant data excesses at the Fe i-K α and Fe xxv-He α  line energies. This means that additional components other than mCVs, non-mCVs, and ABs are required, which have symbiotic phenomena of cold gas and very high-temperature plasma. The GCXE spectrum shows larger excesses than those found in the GRXE spectrum at all the K-shell lines of iron and nickel. Among them the largest ones are the Fe i-K α , Fe xxv-He α , Fe xxvi-Ly α , and Fe xxvi-Ly β  lines. Together with the fact that the scale heights of the Fe i-K α , Fe xxv-He α , and Fe xxvi-Ly α lines are similar to that of the central molecular zone (CMZ), the excess components would be related to high-energy activity in the extreme envelopment of the CMZ.

Greenhouse gas emissions related to Dutch food consumption

NARCIS (Netherlands)

Kramer, KJ; Moll, HC; Nonhebel, S; Wilting, HC

The consumption of food products involves emissions of greenhouse gases. Emissions occur in the various stages of the life cycle of food products. In this paper we discuss the greenhouse gas emissions, CO2, CH4, and N2O, related to Dutch household food consumption. Combinations of greenhouse gas

Greenhouse gas emissions from shale gas and coal for electricity generation in South Africa

Directory of Open Access Journals (Sweden)

Brett Cohen

2014-03-01

Full Text Available There is increased interest, both in South Africa and globally, in the use of shale gas for electricity and energy supply. The exploitation of shale gas is, however, not without controversy, because of the reported environmental impacts associated with its extraction. The focus of this article is on the greenhouse gas footprint of shale gas, which some literature suggests may be higher than what would have been expected as a consequence of the contribution of fugitive emissions during extraction, processing and transport. Based on some studies, it has been suggested that life-cycle emissions may be higher than those from coal-fired power. Here we review a number of studies and analyse the data to provide a view of the likely greenhouse gas emissions from producing electricity from shale gas, and compare these emissions to those of coal-fired power in South Africa. Consideration was given to critical assumptions that determine the relative performance of the two sources of feedstock for generating electricity � that is the global warming potential of methane and the extent of fugitive emissions. The present analysis suggests that a 100-year time horizon is appropriate in analysis related to climate change, over which period the relative contribution is lower than for shorter periods. The purpose is to limit temperature increase in the long term and the choice of metric should be appropriate. The analysis indicates that, regardless of the assumptions about fugitive emissions and the period over which global warming potential is assessed, shale gas has lower greenhouse gas emissions per MWh of electricity generated than coal. Depending on various factors, electricity from shale gas would have a specific emissions intensity between 0.3 tCO2/MWh and 0.6 tCO2/MWh, compared with about 1 tCO2/MWh for coal-fired electricity in South Africa.

Monitoring greenhouse gas emissions from landfill sites

International Nuclear Information System (INIS)

Eade, G.

2001-01-01

Methane is the chief component of natural gas, but also occurs naturally by the anaerobic decomposition of organic matter in swamp areas, at landfill sites, in fact at any location where organic deposits are present. Carbon dioxide is also produced by the decomposition of organic material as well as being the primary by-product of combustion. This article focuses on techniques to test a wide variety of combustible and toxic gases, including surface emission testing of landfill sites. Specifically, it describes the Methane Emission Monitoring System (MEMS) developed by Hetek Solutions Inc., whose primary objective is to to effectively locate surface emissions of methane gas from active landfill sites using flame ionization (FI) technology, and to plot the 'hot spots' using a Differential Global Positioning System (DGPS), which provides sub-metre accuracy for plotting emissions locations at landfill sites. The FI equipment is installed on all-terrain vehicles (ATVs). Several thousand kilometers of pipeline inspections have been performed in Alberta and Saskatchewan using this system in the mid-1990s. The mobile FI/ATV units have been redesigned for landfill gas emission testing, equipped with new DGPS equipment and interface software. They meet the New Source Performance Standards (NSPS) drafted in the United States in 1996, which requires all landfill sites to be inspected for methane gas emissions. Using the FI/ATV combination, productivity over conventional walking inspection procedures increased some 400 per cent, while monitoring accuracy is equivalent to or better than those provided by previous conventional methods. The company can also provide the Optical Methane Detector (OMD) system using infrared technology. They are capable of performing 14,000 measurements per second, thus providing immediate response. To date, ATV emissions testing has been proven to be very effective in various types of gas detection. When interfaced with DGPS technology, computer

Greenhouse Gas and Noxious Emissions from Dual Fuel Diesel and Natural Gas Heavy Goods Vehicles.

Science.gov (United States)

Stettler, Marc E J; Midgley, William J B; Swanson, Jacob J; Cebon, David; Boies, Adam M

2016-02-16

Dual fuel diesel and natural gas heavy goods vehicles (HGVs) operate on a combination of the two fuels simultaneously. By substituting diesel for natural gas, vehicle operators can benefit from reduced fuel costs and as natural gas has a lower CO2 intensity compared to diesel, dual fuel HGVs have the potential to reduce greenhouse gas (GHG) emissions from the freight sector. In this study, energy consumption, greenhouse gas and noxious emissions for five after-market dual fuel configurations of two vehicle platforms are compared relative to their diesel-only baseline values over transient and steady state testing. Over a transient cycle, CO2 emissions are reduced by up to 9%; however, methane (CH4) emissions due to incomplete combustion lead to CO2e emissions that are 50-127% higher than the equivalent diesel vehicle. Oxidation catalysts evaluated on the vehicles at steady state reduced CH4 emissions by at most 15% at exhaust gas temperatures representative of transient conditions. This study highlights that control of CH4 emissions and improved control of in-cylinder CH4 combustion are required to reduce total GHG emissions of dual fuel HGVs relative to diesel vehicles.

Spatial distribution of FIR rotationally excited CH+ and OH emission lines in the Orion Bar PDR.

Science.gov (United States)

Parikka, A; Habart, E; Bernard-Salas, J; Goicoechea, J R; Abergel, A; Pilleri, P; Dartois, E; Joblin, C; Gerin, M; Godard, B

2017-03-01

The methylidyne cation (CH + ) and hydroxyl (OH) are key molecules in the warm interstellar chemistry, but their formation and excitation mechanisms are not well understood. Their abundance and excitation are predicted to be enhanced by the presence of vibrationally excited H 2 or hot gas (~500-1000 K) in photodissociation regions with high incident FUV radiation field. The excitation may also originate in dense gas (> 10 5 cm -3 ) followed by nonreactive collisions with H 2 , H, and electrons. Previous observations of the Orion Bar suggest that the rotationally excited CH + and OH correlate with the excited CO, a tracer of dense and warm gas, and formation pumping contributes to CH + excitation. Our goal is to examine the spatial distribution of the rotationally excited CH + and OH emission lines in the Orion Bar in order to establish their physical origin and main formation and excitation mechanisms. We present spatially sampled maps of the CH + J=3-2 transition at 119.8 µm and the OH Λ-doublet at 84 µm in the Orion Bar over an area of 110″×110″ with Herschel (PACS). We compare the spatial distribution of these molecules with those of their chemical precursors, C + , O and H 2 , and tracers of warm and dense gas (high-J CO). We assess the spatial variation of CH + J=2-1 velocity-resolved line profile at 1669 GHz with Herschel HIFI spectrometer observations. The OH and especially CH + lines correlate well with the high-J CO emission and delineate the warm and dense molecular region at the edge of the Bar. While notably similar, the differences in the CH + and OH morphologies indicate that CH + formation and excitation are strongly related to the observed vibrationally excited H 2 . This, together with the observed broad CH + line widths, indicates that formation pumping contributes to the excitation of this reactive molecular ion. Interestingly, the peak of the rotationally excited OH 84 µm emission coincides with a bright young object, proplyd 244

Comparison of measured and modeled gas-puff emissions on Alcator C-Mod

Science.gov (United States)

Baek, Seung-Gyou; Terry, J. L.; Stotler, D. P.; Labombard, B. L.; Brunner, D. F.

2017-10-01

Understanding neutral transport in tokamak boundary plasmas is important because of its possible effects on the pedestal and scrape-off layer (SOL). On Alcator C-Mod, measured neutral line emissions from externally-puffed deuterium and helium gases are compared with the synthetic results of a neutral transport code, DEGAS 2. The injected gas flow rate and the camera response are absolutely calibrated. Time-averaged SOL density and temperature profiles are input to a steady-state simulation. An updated helium atomic model is employed in DEGAS2. Good agreement is found for the D α peak brightness and profile shape. However, the measured helium I line brightness is found to be lower than that in the simulation results by a roughly a factor of three over a wide range of density particularly in the far SOL region. Two possible causes for this discrepancy are reviewed. First, local cooling due to gas puff may suppress the line emission. Second, time-dependent turbulence effect may impact the helium neutral transport. Unlike deuterium atoms that gain energy from charge exchange and dissociation processes, helium neutrals remain cold and have a relatively short mean free path, known to make them prone to turbulence based on the Kubo number criterion. Supported by USDoE awards: DE-FC02-99ER54512, DE-SC0014251, and DE-AC02-09CH11466.

A New Radio Spectral Line Survey of Planetary Nebulae: Exploring Radiatively-driven Heating and Chemistry of Molecular Gas

Science.gov (United States)

Bublitz, Jesse; Kastner, Joel H.; Santander-García, Miguel; Montez, Rodolfo; Alcolea, Javier; Balick, Bruce; Bujarrabal, Valentín

2018-01-01

We report the results of a survey of mm-wave molecular line emission from nine nearby (Radioastronomie Millimétrique (IRAM) 30 m telescope. Our sample comprises molecule-rich PNe spanning a wide range of central star UV luminosities as well as central star and nebular X-ray emission properties. Nine molecular line frequencies were chosen to investigate the molecular chemistry of these nebulae. New detections of one or more of five molecules -- the molecular mass tracer 13CO and the chemically important trace species HCO+, CN, HCN, and HNC -- were made in at least one PN. We present analysis of emission line flux ratios that are potential diagnostics of the influence that ultraviolet and X-ray radiation have on the chemistry of residual molecular gas in PNe.

GAME: GAlaxy Machine learning for Emission lines

Science.gov (United States)

Ucci, G.; Ferrara, A.; Pallottini, A.; Gallerani, S.

2018-06-01

We present an updated, optimized version of GAME (GAlaxy Machine learning for Emission lines), a code designed to infer key interstellar medium physical properties from emission line intensities of ultraviolet /optical/far-infrared galaxy spectra. The improvements concern (a) an enlarged spectral library including Pop III stars, (b) the inclusion of spectral noise in the training procedure, and (c) an accurate evaluation of uncertainties. We extensively validate the optimized code and compare its performance against empirical methods and other available emission line codes (PYQZ and HII-CHI-MISTRY) on a sample of 62 SDSS stacked galaxy spectra and 75 observed HII regions. Very good agreement is found for metallicity. However, ionization parameters derived by GAME tend to be higher. We show that this is due to the use of too limited libraries in the other codes. The main advantages of GAME are the simultaneous use of all the measured spectral lines and the extremely short computational times. We finally discuss the code potential and limitations.

GAME: GAlaxy Machine learning for Emission lines

Science.gov (United States)

Ucci, G.; Ferrara, A.; Pallottini, A.; Gallerani, S.

2018-03-01

We present an updated, optimized version of GAME (GAlaxy Machine learning for Emission lines), a code designed to infer key interstellar medium physical properties from emission line intensities of UV/optical/far infrared galaxy spectra. The improvements concern: (a) an enlarged spectral library including Pop III stars; (b) the inclusion of spectral noise in the training procedure, and (c) an accurate evaluation of uncertainties. We extensively validate the optimized code and compare its performance against empirical methods and other available emission line codes (pyqz and HII-CHI-mistry) on a sample of 62 SDSS stacked galaxy spectra and 75 observed HII regions. Very good agreement is found for metallicity. However, ionization parameters derived by GAME tend to be higher. We show that this is due to the use of too limited libraries in the other codes. The main advantages of GAME are the simultaneous use of all the measured spectral lines, and the extremely short computational times. We finally discuss the code potential and limitations.

Role of natural gas in meeting an electric sector emissions ...

Science.gov (United States)

With advances in natural gas extraction technologies, there is an increase in availability of domestic natural gas, and natural gas is gaining a larger share of use as a fuel in electricity production. At the power plant, natural gas is a cleaner burning fuel than coal, but uncertainties exist in the amount of methane leakage occurring upstream in the extraction and production of natural gas. At high leakage levels, these methane emissions could outweigh the benefits of switching from coal to natural gas. This analysis uses the MARKAL linear optimization model to compare the carbon emissions profiles and system-wide global warming potential of the U.S. energy system over a series of model runs in which the power sector is asked to meet a specific CO2 reduction target and the availability of natural gas changes. Scenarios are run with a range of upstream methane emission leakage rates from natural gas production. While the total CO2 emissions are reduced in most scenarios, total greenhouse gas emissions show an increase or no change when both natural gas availability and methane emissions from natural gas production are high. Article presents summary of results from an analyses of natural gas resource availability and power sector emissions reduction strategies under different estimates of methane leakage rates during natural gas extraction and production. This was study was undertaken as part of the Energy Modeling Forum Study #31:

Coal fired flue gas mercury emission controls

International Nuclear Information System (INIS)

Wu, Jiang; Pan, Weiguo; Cao, Yan; Pan, Weiping

2015-01-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Coal fired flue gas mercury emission controls

Energy Technology Data Exchange (ETDEWEB)

Wu, Jiang; Pan, Weiguo [Shanghai Univ. of Electric Power (China); Cao, Yan; Pan, Weiping [Western Kentucky Univ., Bowling Green, KY (United States)

2015-05-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Galaxy emission line classification using three-dimensional line ratio diagrams

Energy Technology Data Exchange (ETDEWEB)

Vogt, Frédéric P. A.; Dopita, Michael A.; Kewley, Lisa J.; Sutherland, Ralph S. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Scharwächter, Julia [Observatoire de Paris, LERMA (CNRS: UMR8112), 61 Av. de l' Observatoire, F-75014 Paris (France); Basurah, Hassan M.; Ali, Alaa; Amer, Morsi A., E-mail: frederic.vogt@anu.edu.au [Astronomy Department, King Abdulaziz University, P.O. Box 80203, Jeddah (Saudi Arabia)

2014-10-01

Two-dimensional (2D) line ratio diagnostic diagrams have become a key tool in understanding the excitation mechanisms of galaxies. The curves used to separate the different regions—H II-like or excited by an active galactic nucleus (AGN)—have been refined over time but the core technique has not evolved significantly. However, the classification of galaxies based on their emission line ratios really is a multi-dimensional problem. Here we exploit recent software developments to explore the potential of three-dimensional (3D) line ratio diagnostic diagrams. We introduce the ZQE diagrams, which are a specific set of 3D diagrams that separate the oxygen abundance and the ionization parameter of H II region-like spectra and also enable us to probe the excitation mechanism of the gas. By examining these new 3D spaces interactively, we define the ZE diagnostics, a new set of 2D diagnostics that can provide the metallicity of objects excited by hot young stars and that cleanly separate H II region-like objects from the different classes of AGNs. We show that these ZE diagnostics are consistent with the key log [N II]/Hα versus log [O III]/Hβ diagnostic currently used by the community. They also have the advantage of attaching a probability that a given object belongs to one class or the other. Finally, we discuss briefly why ZQE diagrams can provide a new way to differentiate and study the different classes of AGNs in anticipation of a dedicated follow-up study.

The spatial intensity distribution of selected emission lines for Herbig-Haro 1 - Comparison between theory and observations

International Nuclear Information System (INIS)

Noriega-Crespo, A.; Bohm, K.H.; Raga, A.C.

1989-01-01

In this paper, it is shown that most of the spatial intensity distribution of 11 selected emission lines for Herbig-Haro 1 (including the forbidden S II emission lines at 6731 A and 4069 A, the forbidden O III line at 5007 A, and the forbidden O II line at 3727 A) can be explained by a bow shock with a shock velocity of about 150-200 km/sec at the stagnation point, and under the assumption that the gas entering the shock is fully preionized. The results are based on three spectrograms (with a total exposure time of 180 min) obtained consecutively. Specifically, the ratios of each of the forbidden lines to H-alpha were studied, which permitted a critical test of the model. The agreement between the theoretical predictions and the observations was found to be remarkable, considering the complex geometry that a bow shock could have. 38 refs

Future forecast for life-cycle greenhouse gas emissions of LNG and city gas 13A

International Nuclear Information System (INIS)

Okamura, Tomohito; Furukawa, Michinobu; Ishitani, Hisashi

2007-01-01

The objective of this paper is to analyze the most up-to-date data available on total greenhouse-gas emissions of a LNG fuel supply chain and life-cycle of city gas 13A based on surveys of the LNG projects delivering to Japan, which should provide useful basic-data for conducting life-cycle analyses of other product systems as well as future alternative energy systems, because of highly reliable data qualified in terms of its source and representativeness. In addition, the life-cycle greenhouse-gas emissions of LNG and city-gas 13A in 2010 were also predicted, taking into account not only the improvement of technologies, but also the change of composition of LNG projects. As a result of this analysis, the total amount of greenhouse-gas emissions of the whole city-gas 13A chain at present was calculated to be 61.91 g-CO 2 /MJ, and the life-cycle greenhouse-gas emissions of LNG and city-gas 13A in 2010 could be expected to decrease by about 1.1% of the current emissions

DETECTION OF REST-FRAME OPTICAL LINES FROM X-SHOOTER SPECTROSCOPY OF WEAK EMISSION-LINE QUASARS

International Nuclear Information System (INIS)

Plotkin, Richard M.; Gallo, Elena; Shemmer, Ohad; Trakhtenbrot, Benny; Anderson, Scott F.; Brandt, W. N.; Luo, Bin; Schneider, Donald P.; Fan, Xiaohui; Lira, Paulina; Richards, Gordon T.; Strauss, Michael A.; Wu, Jianfeng

2015-01-01

Over the past 15 yr, examples of exotic radio-quiet quasars with intrinsically weak or absent broad emission line regions (BELRs) have emerged from large-scale spectroscopic sky surveys. Here, we present spectroscopy of seven such weak emission line quasars (WLQs) at moderate redshifts (z = 1.4–1.7) using the X-shooter spectrograph, which provides simultaneous optical and near-infrared spectroscopy covering the rest-frame ultraviolet (UV) through optical. These new observations effectively double the number of WLQs with spectroscopy in the optical rest-frame, and they allow us to compare the strengths of (weak) high-ionization emission lines (e.g., C iv) to low-ionization lines (e.g., Mg ii, Hβ, Hα) in individual objects. We detect broad Hβ and Hα emission in all objects, and these lines are generally toward the weaker end of the distribution expected for typical quasars (e.g., Hβ has rest-frame equivalent widths ranging from 15–40 Å). However, these low-ionization lines are not exceptionally weak, as is the case for high-ionization lines in WLQs. The X-shooter spectra also display relatively strong optical Fe ii emission, Hβ FWHM ≲ 4000 km s −1 , and significant C iv blueshifts (≈1000–5500 km s −1 ) relative to the systemic redshift; two spectra also show elevated UV Fe ii emission, and an outflowing component to their (weak) Mg ii emission lines. These properties suggest that WLQs are exotic versions of “wind-dominated” quasars. Their BELRs either have unusual high-ionization components, or their BELRs are in an atypical photoionization state because of an unusually soft continuum

Lifecycle greenhouse gas emissions of coal, conventional and unconventional natural gas for electricity generation

Science.gov (United States)

An analysis of the lifecycle greenhouse gas (GHG) emissions associated with natural gas use recently published by Howarth et al. (2011) stated that use of natural gas produced from shale formations via hydraulic fracturing would generate greater lifecycle GHG emissions than petro...

Emissions credits from natural gas vehicles

International Nuclear Information System (INIS)

Anderson, J.F.; Kodjak, D.

1997-01-01

Dedicated natural gas vehicles (NGVs) often are capable of testing to lower than federally required engine certification standards. NGVs often meet inherently low emission vehicle (ILEV) and ultra low emission vehicle (ULEV) standards. Over the useful life of the vehicle, a significant amount of mobile source emission reduction credits (MSERCs) can be generated. This paper will discuss key elements of establishing a workable methodology to quantify the emissions benefits generated through the purchase and use of heavy-duty natural gas vehicles instead of heavy-duty diesel vehicles. The paper will focus on a public fleet of transit buses owned by the Massachusetts Bay Transit Agency, the Massachusetts Port Authority, and a private fleet of waste haulers. Public fleets may generate emission credits as a key compliance option to offset emission shortfalls from changes to the Employee Commute Options (ECO) program, the Inspection and Maintenance program, and facilitate annual surface transportation conformity. Private fleets may generate emission credits for open market trading to area and stationary sources seeking to buy credits from mobile sources, where allowed by EPA and state policy

Opportunities to reduce methane emissions in the natural gas industry

Energy Technology Data Exchange (ETDEWEB)

Cowgill, R.M. [Radian Corporation, Austin, TX (United States)

1995-12-31

The U.S. Environmental Protection Agency (EPA) and the Gas Research Institute (GRI) cofunded a project to quantify methane (CH{sub 4}) emissions from the U.S. natural gas industry. Methane, the major constituent of natural gas, is a potent greenhouse gas that is believed to increase the effect of global warming when released to the atmosphere. Reducing emissions from natural gas systems would lessen the greenhouse gas effect attributable to atmospheric CH{sub 4}. Further, mitigation methods to reduce emissions of natural gas, a marketable resource, could save money and increase energy efficiency. This presentation summarizes the major sources and quantity of methane being emitted to the atmosphere for all segments of the U.S. gas industry: production; processing; storage; transmission; and distribution. A description of how those emissions were determined is included here, as well as a discussion of which sources are potential candidates for reducing emissions. (author)

Opportunities to reduce methane emissions in the natural gas industry

Energy Technology Data Exchange (ETDEWEB)

Cowgill, R M [Radian Corporation, Austin, TX (United States)

1996-12-31

The U.S. Environmental Protection Agency (EPA) and the Gas Research Institute (GRI) cofunded a project to quantify methane (CH{sub 4}) emissions from the U.S. natural gas industry. Methane, the major constituent of natural gas, is a potent greenhouse gas that is believed to increase the effect of global warming when released to the atmosphere. Reducing emissions from natural gas systems would lessen the greenhouse gas effect attributable to atmospheric CH{sub 4}. Further, mitigation methods to reduce emissions of natural gas, a marketable resource, could save money and increase energy efficiency. This presentation summarizes the major sources and quantity of methane being emitted to the atmosphere for all segments of the U.S. gas industry: production; processing; storage; transmission; and distribution. A description of how those emissions were determined is included here, as well as a discussion of which sources are potential candidates for reducing emissions. (author)

Opportunities to reduce methane emissions in the natural gas industry

International Nuclear Information System (INIS)

Cowgill, R.M.

1995-01-01

The U.S. Environmental Protection Agency (EPA) and the Gas Research Institute (GRI) cofunded a project to quantify methane (CH 4 ) emissions from the U.S. natural gas industry. Methane, the major constituent of natural gas, is a potent greenhouse gas that is believed to increase the effect of global warming when released to the atmosphere. Reducing emissions from natural gas systems would lessen the greenhouse gas effect attributable to atmospheric CH 4 . Further, mitigation methods to reduce emissions of natural gas, a marketable resource, could save money and increase energy efficiency. This presentation summarizes the major sources and quantity of methane being emitted to the atmosphere for all segments of the U.S. gas industry: production; processing; storage; transmission; and distribution. A description of how those emissions were determined is included here, as well as a discussion of which sources are potential candidates for reducing emissions. (author)

Rings of Molecular Line Emission in the Disk Orbiting the Young, Close Binary V4046 Sgr

Science.gov (United States)

Dickson-Vandervelde, Dorothy; Kastner, Joel H.; Qi, C.; Forveille, Thierry; Hily-Blant, Pierre; Oberg, Karin; Wilner, David; Andrews, Sean; Gorti, Uma; Rapson, Valerie; Sacco, Germano; Principe, David

2018-01-01

We present analysis of a suite of subarcsecond ALMA Band 6 (1.1 - 1.4 mm) molecular line images of the circumbinary, protoplanetary disk orbiting V4046 Sgr. The ~20 Myr-old V4046 Sgr system, which lies a mere ~73 pc from Earth, consists of a close (separation ~10 Rsun) pair of roughly solar-mass stars that are orbited by a gas-rich crcumbinary disk extending to ~350 AU in radius. The ALMA images reveal that the molecules CO and HCN and their isotopologues display centrally peaked surface brightness morphologies, whereas the cyanide group molecules (HC3N, CH3CN), deuterated molecules (DCN, DCO+), hydrocarbons (as traced by C2H), and potential CO ice line tracers (N2H+, and H2CO) appear as a sequence of sharp and diffuse rings of increasing radii. The characteristic sizes of these molecular emission rings, which range from ~25 to >100 AU in radius, are evident in radial emission-line surface brightness profiles extracted from the deprojected disk images. We find that emission from 13CO emission transitions from optically thin to thick within ~50 AU, whereas C18O emission remains optically thin within this radius. We summarize the insight into the physical and chemical processes within this evolved protoplanetary disk that can be obtained from comparisons of the various emission-line morphologies with each other and with that of the continuum (large-grain) emission on size scales of tens of AU.This research is supported by NASA Exoplanets program grant NNX16AB43G to RIT

State and Territory Greenhouse Gas Emissions 2004

International Nuclear Information System (INIS)

2006-06-01

This document provides an overview of the latest available estimates of greenhouse gas emissions for Australia's States and Territories. Australia's total greenhouse gas emissions in 2004 amounted to 564.7 million tonnes. The State and Territory breakdown was: New South Wales: 158.7 million tonnes (Mt); Queensland: 158.5 Mt; Victoria: 123.0 Mt; Western Australia: 68.5 Mt; South Australia: 27.6 Mt; Northern Territory: 15.6 Mt; Tasmania: 10.7 Mt; ACT: 1.2 Mt. The summary of State and Territory inventories presented in this document reports estimates of greenhouse gas emissions for each State and Territory for the period 1990 to 2004. It is the first time that a complete annual time-series has been reported

Alternative Fuels Data Center: Wisconsin Reduces Emissions With Natural Gas

Science.gov (United States)

Trucks Wisconsin Reduces Emissions With Natural Gas Trucks to someone by E-mail Share Alternative Fuels Data Center: Wisconsin Reduces Emissions With Natural Gas Trucks on Facebook Tweet about Alternative Fuels Data Center: Wisconsin Reduces Emissions With Natural Gas Trucks on Twitter Bookmark

High-redshift SDSS Quasars with Weak Emission Lines

DEFF Research Database (Denmark)

Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Brandt, W. N.

2009-01-01

We identify a sample of 74 high-redshift quasars (z > 3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z > 4. These weak emission-line quasars (WLQs) constitute a promine...

CO LINE EMISSION FROM COMPACT NUCLEAR STARBURST DISKS AROUND ACTIVE GALACTIC NUCLEI

Energy Technology Data Exchange (ETDEWEB)

Armour, J. N.; Ballantyne, D. R., E-mail: jarmour3@gatech.edu [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30332-0430 (United States)

2012-06-20

There is substantial evidence for a connection between star formation in the nuclear region of a galaxy and growth of the central supermassive black hole. Furthermore, starburst activity in the region around an active galactic nucleus (AGN) may provide the obscuration required by the unified model of AGNs. Molecular line emission is one of the best observational avenues to detect and characterize dense, star-forming gas in galactic nuclei over a range of redshift. This paper presents predictions for the carbon monoxide (CO) line features from models of nuclear starburst disks around AGNs. These small-scale ({approx}< 100 pc), dense and hot starbursts have CO luminosities similar to scaled-down ultra-luminous infrared galaxies and quasar host galaxies. Nuclear starburst disks that exhibit a pc-scale starburst and could potentially act as the obscuring torus show more efficient CO excitation and higher brightness temperature ratios than those without such a compact starburst. In addition, the compact starburst models predict strong absorption when J{sub Upper} {approx}> 10, a unique observational signature of these objects. These findings allow for the possibility that CO spectral line energy distributions (SLEDs) could be used to determine if starburst disks are responsible for the obscuration in z {approx}< 1 AGNs. Directly isolating the nuclear CO line emission of such compact regions around AGNs from galactic-scale emission will require high-resolution imaging or selecting AGN host galaxies with weak galactic-scale star formation. Stacking individual CO SLEDs will also be useful in detecting the predicted high-J features.

Outflow Kinematics Manifested by the Hα Line: Gas Outflows in Type 2 AGNs. IV

Energy Technology Data Exchange (ETDEWEB)

Kang, Daeun; Woo, Jong-Hak; Bae, Hyun-Jin, E-mail: woo@astro.snu.ac.kr [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)

2017-08-20

Energetic ionized gas outflows driven by active galactic nuclei (AGNs) have been studied as a key phenomenon related to AGN feedback. To probe the kinematics of the gas in the narrow-line region, [O iii] λ 5007 has been utilized in a number of studies showing nonvirial kinematic properties due to AGN outflows. In this paper, we statistically investigate whether the H α emission line is influenced by AGN-driven outflows by measuring the kinematic properties based on the H α line profile and comparing them with those of [O iii]. Using the spatially integrated spectra of ∼37,000 Type 2 AGNs at z < 0.3 selected from the Sloan Digital Sky Survey DR7, we find a nonlinear correlation between H α velocity dispersion and stellar velocity dispersion that reveals the presence of the nongravitational component, especially for AGNs with a wing component in H α . The large H α velocity dispersion and velocity shift of luminous AGNs are clear evidence of AGN outflow impacts on hydrogen gas, while relatively smaller kinematic properties compared to those of [O iii] imply that the observed outflow effect on the H α line is weaker than the case of [O iii].

Upscaling of greenhouse gas emissions in upland forestry following clearfell

Science.gov (United States)

Toet, Sylvia; Keane, Ben; Yamulki, Sirwan; Blei, Emanuel; Gibson-Poole, Simon; Xenakis, Georgios; Perks, Mike; Morison, James; Ineson, Phil

2016-04-01

Data on greenhouse gas (GHG) emissions caused by forest management activities are limited. Management such as clearfelling may, however, have major impacts on the GHG balance of forests through effects of soil disturbance, increased water table, and brash and root inputs. Besides carbon dioxide (CO2), the biogenic GHGs nitrous oxide (N2O) and methane (CH4) may also contribute to GHG emissions from managed forests. Accurate flux estimates of all three GHGs are therefore necessary, but, since GHG emissions usually show large spatial and temporal variability, in particular CH4 and N2O fluxes, high-frequency GHG flux measurements and better understanding of their controls are central to improve process-based flux models and GHG budgets at multiple scales. In this study, we determined CO2, CH4 and N2O emissions following felling in a mature Sitka spruce (Picea sitchensis) stand in an upland forest in northern England. High-frequency measurements were made along a transect using a novel, automated GHG chamber flux system ('SkyLine') developed at the University of York. The replicated, linear experiment aimed (1) to quantify GHG emissions from three main topographical features at the clearfell site, i.e. the ridges on which trees had been planted, the hollows in between and the drainage ditches, and (2) to determine the effects of the green-needle component of the discarded brash. We also measured abiotic soil and climatic factors alongside the 'SkyLine' GHG flux measurements to identify drivers of the observed GHG emissions. All three topographic features were overall sources of GHG emissions (in CO2 equivalents), and, although drainage ditches are often not included in studies, GHG emissions per unit area were highest from ditches, followed by ridges and lowest in hollows. The CO2 emissions were most important in the GHG balance of ridges and hollows, but CH4 emissions were very high from the drainage ditches, contributing to over 50% of their overall net GHG emissions

On-line optimal control improves gas processing

International Nuclear Information System (INIS)

Berkowitz, P.N.; Papadopoulos, M.N.

1992-01-01

This paper reports that the authors' companies jointly funded the first phase of a gas processing liquids optimization project that has the specific purposes to: Improve the return of processing natural gas liquids, Develop sets of control algorithms, Make available a low-cost solution suitable for small to medium-sized gas processing plants, Test and demonstrate the feasibility of line control. The ARCO Willard CO 2 gas recovery processing plant was chosen as the initial test site to demonstrate the application of multivariable on-line optimal control. One objective of this project is to support an R ampersand D effort to provide a standardized solution to the various types of gas processing plants in the U.S. Processes involved in these gas plants include cryogenic separations, demethanization, lean oil absorption, fractionation and gas treating. Next, the proposed solutions had to be simple yet comprehensive enough to allow an operator to maintain product specifications while operating over a wide range of gas input flow and composition. This had to be a supervisors system that remained on-line more than 95% of the time, and achieved reduced plant operating variability and improved variable cost control. It took more than a year to study various gas processes and to develop a control approach before a real application was finally exercised. An initial process for C 2 and CO 2 recoveries was chosen

Methane emissions from U.S. natural gas operations

International Nuclear Information System (INIS)

Lott, R.A.

1992-01-01

The Gas Research Institute and the U.S. Environmental Protection Agency are cofunding and comanaging a program to evaluate methane emissions from U.S. natural gas operations. The purpose of the program is to provide an emissions inventory accurate enough for global climate modeling and for addressing the policy question of ''whether encouraging the increased use of natural gas is a viable strategy for reducing the U.S. contribution to global warming''. The program is comprised of three phases: Scoping, Methods Development, and Implementation. The purpose of Phase I was to define the problem. Phase II of the program concentrated on developing techniques for measuring steady state or fugitive emissions and for calculating the highly variable unsteady emissions from the variety of sources that comprise the gas industry. Because of the large number of sources within each source type, techniques were also developed for extrapolating emissions data to similar sources within the industry. Phase III of the program was started in early 1992 and should be completed in early 1994. The purpose of the current phase of the program is to collect sufficient data to achieve the accuracy goal of determining emissions to within ± 0.5 percent of production. Based on the limited amount of data collected to date, methane emissions from the U.S. gas industry appear to be in the range of 1 percent of production. (au) (19 refs.)

Particle emissions from compressed natural gas engines

International Nuclear Information System (INIS)

Ristovski, Z.D.; Morawska, L.; Hitchins, J.; Thomas, S.; Greenaway, C.; Gilbert, D.

2000-01-01

This paper presents the results of measurements conducted to determine particle and gas emissions from two large compressed natural gas (CNG) spark ignition (SI) engines. Particle size distributions in the range from 0.01-30 μm, and gas composition were measured for five power settings of the engines: 35, 50, 65, 80 and 100% of full power. Particle emissions in the size range between 0.5 and 30 μm, measured by the aerodynamic particle sizer (APS), were very low at a level below two particles cm -3 . These concentrations were comparable with average ambient concentration, and were not considered in the succeeding analysis. Both engines produce significant amounts of particles in the size range between 0.015 and 0.7 μm, measured by the scanning mobility particle size (SMPS). Maximum number of concentrations of about 1 x 10 7 particles cm -3 were very similar for both engines. The CMDs were in the range between 0.020 and 0.060 μm. The observed levels of particulate emission are in terms of number of the same order as emissions from heavy duty diesel engines (Morawska et al., Environ. Sci. Tech. 32, 2033-2042). On the other hand, emissions of CO and NO x of 5.53 and 3.33 g k W h -1 , respectively, for one of the tested engines, were considerably lower than set by the standards. According to the specifications for the gas emissions, provided by the US EPA (US EPA, 1997), this engine can be considered as a 'low-emission' engine, although emissions of submicrometer particles are of the same order as heavy-duty vehicles. (Author)

HOT GAS LINES IN T TAURI STARS

International Nuclear Information System (INIS)

Ardila, David R.; Herczeg, Gregory J.; Gregory, Scott G.; Hillenbrand, Lynne A.; Ingleby, Laura; Bergin, Edwin; Bethell, Thomas; Calvet, Nuria; France, Kevin; Brown, Alexander; Edwards, Suzan; Johns-Krull, Christopher; Linsky, Jeffrey L.; Yang, Hao; Valenti, Jeff A.; Abgrall, Hervé; Alexander, Richard D.; Brown, Joanna M.; Espaillat, Catherine; Hussain, Gaitee

2013-01-01

For Classical T Tauri Stars (CTTSs), the resonance doublets of N V, Si IV, and C IV, as well as the He II 1640 Å line, trace hot gas flows and act as diagnostics of the accretion process. In this paper we assemble a large high-resolution, high-sensitivity data set of these lines in CTTSs and Weak T Tauri Stars (WTTSs). The sample comprises 35 stars: 1 Herbig Ae star, 28 CTTSs, and 6 WTTSs. We find that the C IV, Si IV, and N V lines in CTTSs all have similar shapes. We decompose the C IV and He II lines into broad and narrow Gaussian components (BC and NC). The most common (50%) C IV line morphology in CTTSs is that of a low-velocity NC together with a redshifted BC. For CTTSs, a strong BC is the result of the accretion process. The contribution fraction of the NC to the C IV line flux in CTTSs increases with accretion rate, from ∼20% to up to ∼80%. The velocity centroids of the BCs and NCs are such that V BC ∼> 4 V NC , consistent with the predictions of the accretion shock model, in at most 12 out of 22 CTTSs. We do not find evidence of the post-shock becoming buried in the stellar photosphere due to the pressure of the accretion flow. The He II CTTSs lines are generally symmetric and narrow, with FWHM and redshifts comparable to those of WTTSs. They are less redshifted than the CTTSs C IV lines, by ∼10 km s –1 . The amount of flux in the BC of the He II line is small compared to that of the C IV line, and we show that this is consistent with models of the pre-shock column emission. Overall, the observations are consistent with the presence of multiple accretion columns with different densities or with accretion models that predict a slow-moving, low-density region in the periphery of the accretion column. For HN Tau A and RW Aur A, most of the C IV line is blueshifted suggesting that the C IV emission is produced by shocks within outflow jets. In our sample, the Herbig Ae star DX Cha is the only object for which we find a P-Cygni profile in the C IV

Laser induced aluminiun plasma analysis by optical emission spectroscopy in a nitrogen background gas

International Nuclear Information System (INIS)

Chamorro, J C; Uzuriaga, J; Riascos, H

2012-01-01

We studied an Al plasma generated by a Nd:YAG laser with a laser fluence of 4 J/cm 2 , a wavelength of 1064 nm, energy pulse of 500 mJ and 10 Hz repetition rate. We studied their spectral characteristics at various ambient nitrogen pressures by optical emission spectroscopy (OES). The N 2 gas pressure was varied from 20 mTorr to 150 mTorr. In Al plume, both atomic and ionic spectra were observed. The electron temperature and electron number density of the plume as of the function ambient gas pressure were determined. The electron temperature was calculated by using the Boltzmann-plot method and the number density was calculated considering the stark effect as dominating on the emission lines.

NOx emission reduction from gas turbines

International Nuclear Information System (INIS)

Groppi, G.; Lietti, L.; Forzatti, P.

2001-01-01

NO x emissions from gas turbines are a serious environmental concern. Primary control technologies significantly reduce NO x formation, which however is still too high to match increasingly strict emission laws. Catalytic processes can provide lower NO x emissions both as primary and secondary control methods, but their economics should be carefully addressed [it

Compendium of Greenhouse Gas Emissions Estimation Methodologies for the Oil and Gas Industry

Energy Technology Data Exchange (ETDEWEB)

Shires, T.M.; Loughran, C.J. [URS Corporation, Austin, TX (United States)

2004-02-01

This document is a compendium of currently recognized methods and provides details for all oil and gas industry segments to enhance consistency in emissions estimation. This Compendium aims to accomplish the following goals: Assemble an expansive collection of relevant emission factors for estimating GHG emissions, based on currently available public documents; Outline detailed procedures for conversions between different measurement unit systems, with particular emphasis on implementation of oil and gas industry standards; Provide descriptions of the multitude of oil and gas industry operations, in its various segments, and the associated emissions sources that should be considered; and Develop emission inventory examples, based on selected facilities from the various segments, to demonstrate the broad applicability of the methodologies. The overall objective of developing this document is to promote the use of consistent, standardized methodologies for estimating GHG emissions from petroleum industry operations. The resulting Compendium documents recognized calculation techniques and emission factors for estimating GHG emissions for oil and gas industry operations. These techniques cover the calculation or estimation of emissions from the full range of industry operations - from exploration and production through refining, to the marketing and distribution of products. The Compendium presents and illustrates the use of preferred and alternative calculation approaches for carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions for all common emission sources, including combustion, vented, and fugitive. Decision trees are provided to guide the user in selecting an estimation technique based on considerations of materiality, data availability, and accuracy. API will provide (free of charge) a calculation tool based on the emission estimation methodologies described herein. The tool will be made available at http://ghg.api.org/.

Toxic fluoride gas emissions from lithium-ion battery fires.

Science.gov (United States)

Larsson, Fredrik; Andersson, Petra; Blomqvist, Per; Mellander, Bengt-Erik

2017-08-30

Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15-22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF 3 ), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.

A First Comparison of Millimeter Continuum and Mg ii Ultraviolet Line Emission from the Solar Chromosphere

Energy Technology Data Exchange (ETDEWEB)

Bastian, T. S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Chintzoglou, G.; De Pontieu, B.; Schmit, D. [Lockheed Martin Solar and Astrophysics Lab, Org. A021S, Building 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Shimojo, M. [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan); Leenaarts, J. [Institute for Solar Physics, Department of Astronomy, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Loukitcheva, M., E-mail: tbastian@nrao.edu [Center For Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102 (United States)

2017-08-20

We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph ( IRIS ). Both millimeter/submillimeter- λ continuum emission and ultraviolet (UV) line emission originate from the solar chromosphere and both have the potential to serve as powerful and complementary diagnostics of physical conditions in this enigmatic region of the solar atmosphere. The observations were made of a solar active region on 2015 December 18 as part of the ALMA science verification effort. A map of the Sun’s continuum emission was obtained by ALMA at a wavelength of 1.25 mm (239 GHz). A contemporaneous map was obtained by IRIS in the Mg ii h doublet line at 2803.5 Å. While a clear correlation between the 1.25 mm brightness temperature T{sub B} and the Mg ii h line radiation temperature T {sub rad} is observed, the slope is <1, perhaps as a result of the fact that these diagnostics are sensitive to different parts of the chromosphere and that the Mg ii h line source function includes a scattering component. There is a significant difference (35%) between the mean T{sub B} (1.25 mm) and mean T {sub rad} (Mg ii). Partitioning the maps into “sunspot,” “quiet areas,” and “plage regions” we find the relation between the IRIS Mg ii h line T {sub rad} and the ALMA T {sub B} region-dependent. We suggest this may be the result of regional dependences of the formation heights of the IRIS and ALMA diagnostics and/or the increased degree of coupling between the UV source function and the local gas temperature in the hotter, denser gas in plage regions.

A First Comparison of Millimeter Continuum and Mg ii Ultraviolet Line Emission from the Solar Chromosphere

International Nuclear Information System (INIS)

Bastian, T. S.; Chintzoglou, G.; De Pontieu, B.; Schmit, D.; Shimojo, M.; Leenaarts, J.; Loukitcheva, M.

2017-01-01

We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph ( IRIS ). Both millimeter/submillimeter- λ continuum emission and ultraviolet (UV) line emission originate from the solar chromosphere and both have the potential to serve as powerful and complementary diagnostics of physical conditions in this enigmatic region of the solar atmosphere. The observations were made of a solar active region on 2015 December 18 as part of the ALMA science verification effort. A map of the Sun’s continuum emission was obtained by ALMA at a wavelength of 1.25 mm (239 GHz). A contemporaneous map was obtained by IRIS in the Mg ii h doublet line at 2803.5 Å. While a clear correlation between the 1.25 mm brightness temperature T_B and the Mg ii h line radiation temperature T _r_a_d is observed, the slope is <1, perhaps as a result of the fact that these diagnostics are sensitive to different parts of the chromosphere and that the Mg ii h line source function includes a scattering component. There is a significant difference (35%) between the mean T_B (1.25 mm) and mean T _r_a_d (Mg ii). Partitioning the maps into “sunspot,” “quiet areas,” and “plage regions” we find the relation between the IRIS Mg ii h line T _r_a_d and the ALMA T _B region-dependent. We suggest this may be the result of regional dependences of the formation heights of the IRIS and ALMA diagnostics and/or the increased degree of coupling between the UV source function and the local gas temperature in the hotter, denser gas in plage regions.

Particle Emissions from Domestic Gas Cookers

DEFF Research Database (Denmark)

Glarborg, Peter; Livbjerg, Hans; Wagner, Ayten Yilmaz

2010-01-01

The authors experimentally studied the formation of submicron particles from a domestic gas cooker in a compartment free from external particle sources. The effects of fuel (methane, natural gas, odorant-free natural gas), primary aeration, flow rate, and fuel sulphur content on particle emissions...... of the emitted particles were found to have a mean value of about 7 nm for partially premixed flames, increasing to ∼10 nm for nonpremixed flames. The quantity of primary air had a strong impact on the particle emissions, showing a minimum at a primary aeration level of 60-65%. Presence of sulphur in small...... quantities may enhance particle formation under some conditions, but results were not conclusive....

ISOLDE Off-line Gas Leak Upgrade

CERN Document Server

Nielsen, Kristoffer Bested

2017-01-01

This study investigates gas injection system of the ISOLDE Off-line separator. A quadrupole mass spectrometer is used to analysis the composition of the gas. Based on these measurements a contamination of the injected gas is found and a system upgrade is purposed. Furthermore a calibration of the leak rate of the leak valve is made.

Pressure dependence of emission intensity of rare-gas excimer light produced by silent discharge; Teikiatsu ryoiki ni okeru musei hoden reiki ki gas excimer hikari shutsuryoku no atsuryoku izonsei

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Y.; Tanaka, M.; Yukimura, K. [Doshisha University, Kyoto (Japan)

1996-09-20

To establish the pressure dependence of silent discharge excited rare gas excimer light emission, a vacua ultraviolet light was subjected to spectroscopic analysis at a pressure lower than 20kPa. Researches are under way to apply the discharge excited rare gas excimer lamp as a vacuum ultraviolet light source for the development of new materials and for the conservation of environments. When the pressure is as low as 1.8kPa or 4.4kPa, the emission has peaks at wavelengths centering on 147nm and 149nm, both of which are the resonance lines of the xenon atom. Excimer generation becomes prominent as the pressure increases, with the second continuum of light growing dominant at 35kPa to weaken relatively the resonance lines and the first continuum of light. In the first continuum, emission increases only at a suppressed rate, as compared with emission in the second continuum, due for instance to a collision caused relaxation process in which excimers are lost. In the case of xenon in the vicinity of 10-11kPa, the first continuum of light and the second continuum of light are approximately equal in emission intensity, producing a vacuum ultraviolet light source with a bandwidth relatively large for a single gas spectrum. 14 refs., 11 figs.

Development of sealing plug for sweep gas line

International Nuclear Information System (INIS)

Kikuchi, Taiji; Yamada, Hirokazu; Saitoh, Takashi; Nakamichi, Masaru; Tsuchiya, Kunihiko; Kawamura, Hiroshi

2004-03-01

On the irradiation capsule for neutron irradiation test of the tritium breeder, the sealing plug is necessary to prevent a leak of tritium gas when the tritium breeder is picked up from the irradiation capsule after irradiation test. However, the general valve and plug cannot apply to sealing of the sweep gas line because of the following factors, the neutron irradiation effect, limited space in the irradiation capsule, high sealing efficiency, simple method and operation for control. Therefore, the sealing plug for sweep gas line has to be developed. This paper reports the development of the sealing plug for sweep gas line and the operating procedure of the sealing plug in the irradiation capsule. (author)

Greenhouse gas emissions trading and project-based mechanisms. Proceedings - CATEP

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-01-01

Greenhouse gas emissions trading and project-based mechanisms for greenhouse gas reduction are emerging market-based instruments for climate change policy. This book presents a selection of papers from an international workshop co-sponsored by the OECD and Concerted Action on Tradeable Emissions Permits (CATEP), to discuss key research and policy issues relating to the design and implementation of these instruments. The papers cover the experience of developing and transition countries with greenhouse gas emissions trading and project-based mechanisms. In addition, the papers examine the use of tradeable permits in policy mixes and harmonisation of emissions trading schemes, as well as transition issues relating to greenhouse gas emissions trading markets.

OPIC Greenhouse Gas Emissions Inventory

Data.gov (United States)

Overseas Private Investment Corporation — Independent analysis details quantifying the greenhouse gas ("GHG") emissions directly attributable to projects to which the Overseas Private Investment Corporation...

On-line depth measurement for laser-drilled holes based on the intensity of plasma emission

Science.gov (United States)

Ho, Chao-Ching; Chiu, Chih-Mu; Chang, Yuan-Jen; Hsu, Jin-Chen; Kuo, Chia-Lung

2014-09-01

The direct time-resolved depth measurement of blind holes is extremely difficult due to the short time interval and the limited space inside the hole. This work presents a method that involves on-line plasma emission acquisition and analysis to obtain correlations between the machining processes and the optical signal output. Given that the depths of laser-machined holes can be estimated on-line using a coaxial photodiode, this was employed in our inspection system. Our experiments were conducted in air under normal atmospheric conditions without gas assist. The intensity of radiation emitted from the vaporized material was found to correlate with the depth of the hole. The results indicate that the estimated depths of the laser-drilled holes were inversely proportional to the maximum plasma light emission measured for a given laser pulse number.

Emission-line galaxies toward the booetes void

International Nuclear Information System (INIS)

Moody, J.W.

1986-01-01

Galaxies with strong emission are potentially useful as probes of the large-scale galaxian distribution. However, to serve as probes, their relative frequency and clustering properties must be known. This dissertation presents a study of these properties for field galaxies having [OIII] λ5007 emission equivalent widths greater than 10 A and reports on a search for galaxies with [OIII] λ5007 emission in the direction of the Booetes void, a volume located at α = 4/sup h/48/sup m/, δ = 47 0 , and cz = 15,000 km/sec that has been demonstrated to be under-abundant in galaxies by a factor of at least four. The study of field emission-line galaxies was done in two magnitude limited surveys consisting of 341 galaxies from both the north and south galactic caps having previously published redshifts and photometry. The galaxy spectra used for redshifts were examined and supplemented by new observations for 56 objects, primarily those with confirmed or suspected emission. Emission-line galaxies were found to comprise 8.8% of galaxies in a Illa-J selected sample or 6.6% of galaxies in a Illa-F selected sample. A search for emission-line galaxies towards the Booetes void was undertaken using the Burrell Schmidt telescope and an objective prism giving a reciprocal dispersion of 900 A/mm at Hβ. Three galaxies were found to lie within it, a result consistent with distributions through the void ranging from uniform to under-abundant by a factor of three

DISSECTING THE POWER SOURCES OF LOW-LUMINOSITY EMISSION-LINE GALAXY NUCLEI VIA COMPARISON OF HST-STIS AND GROUND-BASED SPECTRA

Energy Technology Data Exchange (ETDEWEB)

Constantin, Anca; Castillo, Christopher A. [Department of Physics and Astronomy, James Madison University, Harrisonburg, VA 22807 (United States); Shields, Joseph C. [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Barth, Aaron J. [Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2015-12-01

Using a sample of ∼100 nearby line-emitting galaxy nuclei, we have built the currently definitive atlas of spectroscopic measurements of Hα and neighboring emission lines at subarcsecond scales. We employ these data in a quantitative comparison of the nebular emission in Hubble Space Telescope (HST) and ground-based apertures, which offer an order-of-magnitude difference in contrast, and provide new statistical constraints on the degree to which transition objects and low-ionization nuclear emission-line regions (LINERs) are powered by an accreting black hole at ≲10 pc. We show that while the small-aperture observations clearly resolve the nebular emission, the aperture dependence in the line ratios is generally weak, and this can be explained by gradients in the density of the line-emitting gas: the higher densities in the more nuclear regions potentially flatten the excitation gradients, suppressing the forbidden emission. The transition objects show a threefold increase in the incidence of broad Hα emission in the high-resolution data, as well as the strongest density gradients, supporting the composite model for these systems as accreting sources surrounded by star-forming activity. The narrow-line LINERs appear to be the weaker counterparts of the Type 1 LINERs, where the low accretion rates cause the disappearance of the broad-line component. The enhanced sensitivity of the HST observations reveals a 30% increase in the incidence of accretion-powered systems at z ≈ 0. A comparison of the strength of the broad-line emission detected at different epochs implies potential broad-line variability on a decade-long timescale, with at least a factor of three in amplitude.

Methodology for reporting 2011 B.C. public sector greenhouse gas emissions

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-12-15

In order to reduce its greenhouse gas emissions, British Columbia promulgated legislation under which the public sector is expected to become carbon neutral starting in 2010 and provincial public sector organizations (PSOs) must report their emissions annually. The aim of this report is to present the emission factors and methodology for calculating and reporting PSO emissions used in 2011. Emission factors represent the amount of greenhouse gas emitted from a specific activity. This document provides emission factors for all in scope categories: stationary sources, indirect emissions, mobile sources and business travel; it also presents a sample calculation of greenhouse gas emissions. The government of British Columbia developed SMARTTool, a web-based program which calculates and reports emissions from stationary sources, indirect emissions and mobile sources. In addition the SMART Travel Emissions Calculator was created to report business travel greenhouse gas emissions through SMARTTool.

Spatial distribution of FIR rotationally excited CH+ and OH emission lines in the Orion Bar PDR⋆

Science.gov (United States)

Parikka, A.; Habart, E.; Bernard-Salas, J.; Goicoechea, J. R.; Abergel, A.; Pilleri, P.; Dartois, E.; Joblin, C.; Gerin, M.; Godard, B.

2016-01-01

Context The methylidyne cation (CH+) and hydroxyl (OH) are key molecules in the warm interstellar chemistry, but their formation and excitation mechanisms are not well understood. Their abundance and excitation are predicted to be enhanced by the presence of vibrationally excited H2 or hot gas (~500–1000 K) in photodissociation regions with high incident FUV radiation field. The excitation may also originate in dense gas (> 105 cm−3) followed by nonreactive collisions with H2, H, and electrons. Previous observations of the Orion Bar suggest that the rotationally excited CH+ and OH correlate with the excited CO, a tracer of dense and warm gas, and formation pumping contributes to CH+ excitation. Aims Our goal is to examine the spatial distribution of the rotationally excited CH+ and OH emission lines in the Orion Bar in order to establish their physical origin and main formation and excitation mechanisms. Methods We present spatially sampled maps of the CH+ J=3-2 transition at 119.8 µm and the OH Λ-doublet at 84 µm in the Orion Bar over an area of 110″×110″ with Herschel (PACS). We compare the spatial distribution of these molecules with those of their chemical precursors, C+, O and H2, and tracers of warm and dense gas (high-J CO). We assess the spatial variation of CH+ J=2-1 velocity-resolved line profile at 1669 GHz with Herschel HIFI spectrometer observations. Results The OH and especially CH+ lines correlate well with the high-J CO emission and delineate the warm and dense molecular region at the edge of the Bar. While notably similar, the differences in the CH+ and OH morphologies indicate that CH+ formation and excitation are strongly related to the observed vibrationally excited H2. This, together with the observed broad CH+ line widths, indicates that formation pumping contributes to the excitation of this reactive molecular ion. Interestingly, the peak of the rotationally excited OH 84 µm emission coincides with a bright young object, proplyd

Rough surface mitigates electron and gas emission

International Nuclear Information System (INIS)

Molvik, A.

2004-01-01

Heavy-ion beams impinging on surfaces near grazing incidence (to simulate the loss of halo ions) generate copious amounts of electrons and gas that can degrade the beam. We measured emission coefficients of η e (le) 130 and η 0 ∼ 10 4 respectively, with 1 MeV K + incident on stainless steel. Electron emission scales as η e ∝ 1/cos(θ), where θ is the ion angle of incidence relative to normal. If we were to roughen a surface by blasting it with glass beads, then ions that were near grazing incidence (90 o ) on smooth surface would strike the rims of the micro-craters at angles closer to normal incidence. This should reduce the electron emission: the factor of 10 reduction, Fig. 1(a), implies an average angle of incidence of 62 o . Gas desorption varies more slowly with θ (Fig. 1(b)) decreasing a factor of ∼2, and along with the electron emission is independent of the angle of incidence on a rough surface. In a quadrupole magnet, electrons emitted by lost primary ions are trapped near the wall by the magnetic field, but grazing incidence ions can backscatter and strike the wall a second time at an azimuth where magnetic field lines intercept the beam. Then, electrons can exist throughout the beam (see the simulations of Cohen, HIF News 1-2/04). The SRIM (TRIM) Monte Carlo code predicts that 60-70% of 1 MeV K + ions backscatter when incident at 88-89 o from normal on a smooth surface. The scattered ions are mostly within ∼10 o of the initial direction but a few scatter by up to 90 o . Ion scattering decreases rapidly away from grazing incidence, Fig. 1(c ). At 62 deg. the predicted ion backscattering (from a rough surface) is 3%, down a factor of 20 from the peak, which should significantly reduce electrons in the beam from lost halo ions. These results are published in Phys. Rev. ST - Accelerators and Beams

ALMA Maps of Dust and Warm Dense Gas Emission in the Starburst Galaxy IC 5179

Energy Technology Data Exchange (ETDEWEB)

Zhao Yinghe [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Lu, Nanyao; Xu, C. Kevin [National Astronomical Observatories of China, Chinese Academy of Sciences, Beijing 100012 (China); Díaz-Santos, Tanio [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Gao Yu [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Charmandaris, Vassilis [Department of Physics, University of Crete, GR-71003 Heraklion (Greece); Werf, Paul van der [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Zhang Zhi-Yu [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Cao, Chen, E-mail: zhaoyinghe@ynao.ac.cn [School of Space Science and Physics, Shandong University at Weihai, Weihai, Shandong 264209 (China)

2017-08-10

We present our high-resolution (0.″15 × 0.″13, ∼34 pc) observations of the CO (6−5) line emission, which probes the warm and dense molecular gas, and the 434 μ m dust continuum emission in the nuclear region of the starburst galaxy IC 5179, conducted with the Atacama Large Millimeter Array (ALMA). The CO (6−5) emission is spatially distributed in filamentary structures with many dense cores and shows a velocity field that is characteristic of a circumnuclear rotating gas disk, with 90% of the rotation speed arising within a radius of ≲150 pc. At the scale of our spatial resolution, the CO (6−5) and dust emission peaks do not always coincide, with their surface brightness ratio varying by a factor of ∼10. This result suggests that their excitation mechanisms are likely different, as further evidenced by the southwest to northeast spatial gradient of both CO-to-dust continuum ratio and Pa- α equivalent width. Within the nuclear region (radius ∼ 300 pc) and with a resolution of ∼34 pc, the CO line flux (dust flux density) detected in our ALMA observations is 180 ± 18 Jy km s{sup −1} (71 ± 7 mJy), which accounts for 22% (2.4%) of the total value measured by Herschel .

Improving the technology of purification of gas emissions petrochemical industries

OpenAIRE

USMANOVA R.R.; ZAIKOV G.E.

2014-01-01

The technology of cleaning of gas emissions flares in the production of synthetic rubber. Developed dynamic scrubber for scrubbing gas emissions. Complex studies served as the basis for the design of an air purification system of industrial premises. Purification of gas emissions before combustion in flares has significantly reduced air pollution by toxic substances.

Accounting For Greenhouse Gas Emissions From Flooded ...

Science.gov (United States)

Nearly three decades of research has demonstrated that the inundation of rivers and terrestrial ecosystems behind dams can lead to enhanced rates of greenhouse gas emissions, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a methodology for estimating methane emissions from flooded lands, but the methodology was published as an appendix to be used a ‘basis for future methodological development’ due to a lack of data. Since the 2006 Guidelines were published there has been a 6-fold increase in the number of peer reviewed papers published on the topic including reports from reservoirs in India, China, Africa, and Russia. Furthermore, several countries, including Iceland, Switzerland, and Finland, have developed country specific methodologies for including flooded lands methane emissions in their National Greenhouse Gas Inventories. This presentation will include a review of the literature on flooded land methane emissions and approaches that have been used to upscale emissions for national inventories. We will also present ongoing research in the United States to develop a country specific methodology. The research approaches include 1) an effort to develop predictive relationships between methane emissions and reservoir characteristics that are available in national databases, such as reservoir size and drainage area, and 2) a national-scale probabilistic survey of reservoir methane emissions. To inform th

Accouting for Greenhouse Gas Emissions from Reservoirs

Science.gov (United States)

Beaulieu, J. J.; Deemer, B. R.; Harrison, J. A.; Nietch, C. T.; Waldo, S.

2016-12-01

Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a methodology for estimating methane emissions from flooded lands, but the methodology was published as an appendix to be used as a `basis for future methodological development' due to a lack of data. Since the 2006 Guidelines were published there has been a 6-fold increase in the number of peer reviewed papers published on the topic including reports from reservoirs in India, China, Africa, and Russia. Furthermore, several countries, including Iceland, Switzerland, and Finland, have developed country specific methodologies for including flooded lands methane emissions in their National Greenhouse Gas Inventories. This presentation will include a review of the literature on flooded land methane emissions and approaches that have been used to upscale emissions for national inventories. We will also present ongoing research in the United States to develop a country specific methodology. In the U.S., research approaches include: 1) an effort to develop predictive relationships between methane emissions and reservoir characteristics that are available in national databases, such as reservoir size and drainage area, and 2) a national-scale probabilistic survey of reservoir methane emissions linked to the National Lakes Assessment.

Urban form and greenhouse gas emissions in Finland

International Nuclear Information System (INIS)

Harmaajaervi, Irmeli

2003-01-01

Finland's regional form is becoming more concentrated, while urban sprawl is causing growth centres to become fragmented. The effects caused by these changes on greenhouse gas emissions were studied up to the year 2010, when, in accordance with the Kyoto protocol, Finland's greenhouse gas emissions should be reduced to the 1990 level. The urban form affects especially transportation inside regions, the potential to utilise district heating and the need for infrastructure. By preventing urban sprawl and by encouraging teleworking and some lifestyle changes, it would be possible to reduce annual transportation emissions by the year 2010 by 1.1 million tonnes CO 2 eq., i.e. 27%, the emissions from residential and service buildings by 1.1 million tonnes CO 2 eq., i.e. 5%, and the emissions from municipal infrastructure by 0.1 million tonnes CO 2 eq., i.e. 6%. Altogether, it is possible to reduce the greenhouse gas emissions by 2.3 million tonnes, which amounts to 15% of Finland's target for emissions reductions in 2010. If the target-oriented scenario is realised, the subsequent decrease of emissions would accelerate. To stop urban sprawl, measures are required in planning, land use and housing policy as well as in transportation and tax policies. Additionally, more needs to be done in regard to co-operation, interaction and information dissemination. This paper introduces a report which estimates, for the first time, the effects caused by changes in the regional and urban forms on the levels of greenhouse gas emissions in Finland

Investigations on burning efficiency and exhaust emission of in-line type emulsified fuel system

Energy Technology Data Exchange (ETDEWEB)

Tseng, Y.K. [National Chinyi University of Technology (Taiwan). Dept. of Mechanical Engineering; Cheng, H.C. [Point Environmental Protection Technology Company Limited (Taiwan)

2011-07-28

In this research, the burning efficiency as well as exhaust emission of a new water-in-oil emulsified fuel system was studied. This emulsified system contains two core processes, the first one is to mix 97% water with 3% emulsifier by volume, and get the milk-like emulsified liquid, while the second one is to compound the milk-like emulsified liquid with heavy oil then obtain the emulsified fuel. In order to overcome the used demulsification problem during in reserve or in transport, this system was designed as a made and use in-line type. From the results of a series of burning tests, the fuel saving can be 8--15%. Also, from the comparison of decline for the heat value and total energy output of emulsified fuel, one can find that the water as the dispersed phase in the combustion process will lead to a micro-explosion as well as the water gas effect, both can raise the combustion temperature and burning efficiency. By comparing the waste gas emission of different types of emulsified fuel, one can know that, the CO2 emission reduces approximately 14%, and NOx emission reduces above 46%, meaning the reduction of the exhaust gas is truly effective. From the exhaust temperature of tail pipe, the waste heat discharge also may reduce 27%, it is quite advantageous to the global warming as well as earth environmental protection.

Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type

Energy Technology Data Exchange (ETDEWEB)

England, G.C.; McGrath, T.P. [GE-Energy and Environmental Research Corp., Irvine, CA (United States); Gilmer, L. [Equilon Enterprises, Bellaire, TX (United States); Seebold, J.G. [Chevron Research and Technology Co., Richmond, CA (United States); Lev-On, M. [ARCO, Los Angeles, CA (United States); Hunt, T. [American Petroleum Institute, Washington, DC (United States)

2001-07-01

Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NO{sub x} emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. (author)

Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type

International Nuclear Information System (INIS)

England, G.C.; McGrath, T.P.; Gilmer, L.; Seebold, J.G.; Lev-On, M.; Hunt, T.

2001-01-01

Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NO x emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. (author)

Investigation of low-latitude hydrogen emission in terms of a two-component interstellar gas model

International Nuclear Information System (INIS)

Baker, P.L.; Burton, W.B.

1975-01-01

The high-resolution 21-cm hydrogen line observations at low galactic latitude of Burton and Verschuur have been analyzed to determine the large-scale distribution of galactic hydrogen. The distribution parameters are found by model fitting. Optical depth affects have been computed using a two-component gas model. Analysis shows that a multiphase description of the medium is essential to the interpretation of low-latitude emission observations. Where possible, the number of free parameters in the gas model has been reduced. Calculations were performed for a one-component, uniform spin temperature, gas model in order to show the systematic departures between this model and the data caused by the incorrect treatment of the optical depth effect. In the two-component gas, radiative transfer is treated by a Monte Carlo calculation since the opacity of the gas arises in a randomly distributed, cold, optically thick, low velocity-dispersion, cloud medium. The emission arises in both the cloud medium and a smoothly distributed, optically thin, high velocity-dispersion, intercloud medium. The synthetic profiles computed from the two-component model reproduce both the large-scale trends of the observed emission profiles and the magnitude of the small-scale emission irregularities. The analysis permits the determination of values for []he thickness of the galactic disk between half density points, the total observed neutral hydrogen mass of the Galaxy, and the central number density of the intercloud atoms. In addition, the analysis is sensitive to the size of clouds contributing to the observations. Computations also show that synthetic emission profiles based on the two-component model display both the zero-velocity and high-velocity ridges, indicative of optical thinness on a large scale, in spite of the presence of optically thick gas

Dedicated natural gas vehicle with low emission

NARCIS (Netherlands)

Voogd, A. de; Weide, J. van der; Konig, A.; Wegener, R.

1995-01-01

In the introduction an overview is given of international activities in the field of natural gas vehicles. The main incentives for the use of natural gas in vehicles are: emission reduction in urban areas, fuel diversification, and long term availability. Heavy duty natural gas engines are mainly

Energy market reform and greenhouse gas emission reductions

International Nuclear Information System (INIS)

Anon.

1999-01-01

The report reviews micro-economic reform in the energy market and measures the impact that energy market reform is expected to have on greenhouse gas outcomes. It indicates that reform in the electricity and gas industries is delivering what was promised, an efficient market with lower energy prices and, over the longer term, will deliver a gradually reducing rate of greenhouse gas emissions per unit of energy produced. It also recognises that energy market reform has removed some barriers to the entry of less greenhouse gas intense fuels. These trends will result in reduced greenhouse gas intensity in the supply of energy and significant reductions in the growth in greenhouse gas emissions compared to what may have been expected without the reforms

Accounting for Greenhouse Gas Emissions from Reservoirs ...

Science.gov (United States)

Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a methodology for estimating methane emissions from flooded lands, but the methodology was published as an appendix to be used as a ‘basis for future methodological development’ due to a lack of data. Since the 2006 Guidelines were published there has been a 6-fold increase in the number of peer reviewed papers published on the topic including reports from reservoirs in India, China, Africa, and Russia. Furthermore, several countries, including Iceland, Switzerland, and Finland, have developed country specific methodologies for including flooded lands methane emissions in their National Greenhouse Gas Inventories. This presentation will include a review of the literature on flooded land methane emissions and approaches that have been used to upscale emissions for national inventories. We will also present ongoing research in the United States to develop a country specific methodology. In the U.S., research approaches include: 1) an effort to develop predictive relationships between methane emissions and reservoir characteristics that are available in national databases, such as reservoir size and drainage area, and 2) a national-scale probabilistic survey of reservoir methane em

Request for Correction 12003 Greenhouse Gas Emissions Reporting from the Petroleum and Natural Gas Industry

Science.gov (United States)

Request for Correction by the U.S. Chamber of Commerce for information in Greenhouse Gas Emissions Reporting from the Petroleum Gas Industry that regarding methane emissions, volatile organic compounds, and hazardous air pollutants.

The methane emissions of the Swiss gas industry

International Nuclear Information System (INIS)

Xinmin, J.

2004-01-01

This article presents a method for the estimation of the methane emissions caused by the Swiss gas industry. Based on new data on the Swiss gas infrastructure, current emission levels are estimated for methane - one of the major greenhouse gases. The methodology and modelling used, which is based on previous studies on this topic, are discussed. Results are presented that show that the estimates provided by the current study are consistent with earlier data. Scenarios are presented that show that a steady decrease in methane emissions emanating from the Swiss gas industry's installations can be expected by the year 2012. The data used in the study and its results are presented in tabular and graphical form and commented on

Greenhouse Gas Emissions from Hydroelectric Reservoirs in Tropical Regions

International Nuclear Information System (INIS)

Pinguelli Rosa, L.; Aurelio dos Santos, M.; Oliveira dos Santos, E.; Matvienko, B.; Sikar, E.

2004-01-01

This paper discusses emissions by power-dams in the tropics. Greenhouse gas emissions from tropical power-dams are produced underwater through biomass decomposition by bacteria. The gases produced in these dams are mainly nitrogen, carbon dioxide and methane. A methodology was established for measuring greenhouse gases emitted by various power-dams in Brazil. Experimental measurements of gas emissions by dams were made to determine accurately their emissions of methane (CH4) and carbon dioxide (CO2) gases through bubbles formed on the lake bottom by decomposing organic matter, as well as rising up the lake gradient by molecular diffusion. The main source of gas in power-dams reservoirs is the bacterial decomposition (aerobic and anaerobic) of autochthonous and allochthonous organic matter that basically produces CO2 and CH4. The types and modes of gas production and release in the tropics are reviewed

Emission Lines in the Near-infrared Spectra of the Infrared Quintuplet Stars in the Galactic Center

Energy Technology Data Exchange (ETDEWEB)

Najarro, F. [Departamento de Astrofísica, Centro de Astrobiología (CSIC-INTA), Ctra. Torrejón a Ajalvir km 4, E-28850 Torrejón de Ardoz (Spain); Geballe, T. R. [Gemini Observatory, 670 North A’ohoku Place, Hilo, HI 96720 (United States); Figer, D. F. [Center for Detectors, Rochester Institute of Technology, 74 Lomb Memorial Drive, Rochester, NY 14623 (United States); Fuente, D. de la [Instituto de Astronomía, Unidad Académica en Ensenada, Universidad Nacional Autónoma de México, Ensenada 22860, México (Mexico)

2017-08-20

We report the detection of a number of emission lines in the 1.0–2.4 μ m spectra of four of the five bright-infrared dust-embedded stars at the center of the Galactic center’s (GC) Quintuplet Cluster. Spectroscopy of the central stars of these objects is hampered not only by the large interstellar extinction that obscures all of the objects in the GC, but also by the large amounts of warm circumstellar dust surrounding each of the five stars. The pinwheel morphologies of the dust observed previously around two of them are indicative of Wolf–Rayet colliding wind binaries; however, infrared spectra of each of the five have until now revealed only dust continua steeply rising to long wavelengths and absorption lines and bands from interstellar gas and dust. The emission lines detected, from ionized carbon and from helium, are broad and confirm that the objects are dusty late-type carbon Wolf–Rayet stars.

Estimating greenhouse gas emissions of European cities--modeling emissions with only one spatial and one socioeconomic variable.

Science.gov (United States)

Baur, Albert H; Lauf, Steffen; Förster, Michael; Kleinschmit, Birgit

2015-07-01

Substantive and concerted action is needed to mitigate climate change. However, international negotiations struggle to adopt ambitious legislation and to anticipate more climate-friendly developments. Thus, stronger actions are needed from other players. Cities, being greenhouse gas emission centers, play a key role in promoting the climate change mitigation movement by becoming hubs for smart and low-carbon lifestyles. In this context, a stronger linkage between greenhouse gas emissions and urban development and policy-making seems promising. Therefore, simple approaches are needed to objectively identify crucial emission drivers for deriving appropriate emission reduction strategies. In analyzing 44 European cities, the authors investigate possible socioeconomic and spatial determinants of urban greenhouse gas emissions. Multiple statistical analyses reveal that the average household size and the edge density of discontinuous dense urban fabric explain up to 86% of the total variance of greenhouse gas emissions of EU cities (when controlled for varying electricity carbon intensities). Finally, based on these findings, a multiple regression model is presented to determine greenhouse gas emissions. It is independently evaluated with ten further EU cities. The reliance on only two indicators shows that the model can be easily applied in addressing important greenhouse gas emission sources of European urbanites, when varying power generations are considered. This knowledge can help cities develop adequate climate change mitigation strategies and promote respective policies on the EU or the regional level. The results can further be used to derive first estimates of urban greenhouse gas emissions, if no other analyses are available. Copyright © 2015 Elsevier B.V. All rights reserved.

Top-down Constraints on Emissions: Example for Oil and Gas Operations

Science.gov (United States)

Petron, G.; Sweeney, C.; Karion, A.; Brewer, A.; Hardesty, R.; Banta, R. M.; Frost, G. J.; Trainer, M.; Miller, B. R.; Conley, S. A.; Kofler, J.; Newberger, T.; Higgs, J. A.; Wolter, S.; Guenther, D.; Andrews, A. E.; Dlugokencky, E. J.; Lang, P. M.; Montzka, S. A.; Edwards, P. M.; Dube, W. P.; Brown, S. S.; Helmig, D.; Hueber, J.; Rella, C.; Jacobson, G. A.; Wolfe, D. E.; Bruhwiler, L.; Tans, P. P.; Schnell, R. C.

2012-12-01

In many countries, human-caused emissions of the two major long lived greenhouse gases, carbon dioxide and methane, are primarily linked to the use of fossil fuels (coal, oil and natural gas). Fugitive emissions of natural gas (mainly CH4) from the oil and gas exploration and production sector may also be an important contributor to natural gas life cycle/greenhouse gas footprint. Fuel use statistics have traditionally been used in combination with fuel and process specific emission factors to estimate CO2 emissions from fossil-fuel-based energy systems (power plants, motor vehicles…). Fugitive emissions of CH4, in contrast, are much harder to quantify. Fugitive emission levels may vary substantially from one oil and gas producing basin to another and may not scale with common activity data, such as production numbers. In the USA, recent efforts by the industry, States and the US Environmental Protection Agency have focused on developing new bottom-up inventory methodologies to assess methane and volatile organic compounds emissions from oil and gas producing basins. The underlying assumptions behind these inventories are multiple and result de facto in large uncertainties. Independent atmospheric-based estimates of emissions provide another valuable piece of information that can be used to evaluate inventories. Over the past year, the NOAA Earth System Research Laboratory has used its expertise in high quality GHG and wind measurements to evaluate regional emissions of methane from two oil and gas basins in the Rocky Mountain region. Results from these two campaigns will be discussed and compared with available inventories.

ALMA Maps of Dust and Warm Dense Gas Emission in the Starburst Galaxy IC 5179

Science.gov (United States)

Zhao, Yinghe; Lu, Nanyao; Díaz-Santos, Tanio; Xu, C. Kevin; Gao, Yu; Charmandaris, Vassilis; van der Werf, Paul; Zhang, Zhi-Yu; Cao, Chen

2017-08-01

We present our high-resolution (0.″15 × 0.″13, ˜34 pc) observations of the CO (6-5) line emission, which probes the warm and dense molecular gas, and the 434 μm dust continuum emission in the nuclear region of the starburst galaxy IC 5179, conducted with the Atacama Large Millimeter Array (ALMA). The CO (6-5) emission is spatially distributed in filamentary structures with many dense cores and shows a velocity field that is characteristic of a circumnuclear rotating gas disk, with 90% of the rotation speed arising within a radius of ≲150 pc. At the scale of our spatial resolution, the CO (6-5) and dust emission peaks do not always coincide, with their surface brightness ratio varying by a factor of ˜10. This result suggests that their excitation mechanisms are likely different, as further evidenced by the southwest to northeast spatial gradient of both CO-to-dust continuum ratio and Pa-α equivalent width. Within the nuclear region (radius ˜ 300 pc) and with a resolution of ˜34 pc, the CO line flux (dust flux density) detected in our ALMA observations is 180 ± 18 Jy km s-1 (71 ± 7 mJy), which accounts for 22% (2.4%) of the total value measured by Herschel. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Quantifying greenhouse gas emissions from waste treatment facilities

DEFF Research Database (Denmark)

Mønster, Jacob

to be in-stalled in any vehicle and thereby enabling measurements wherever there were roads. The validation of the measurement method was done by releasing a controlled amount of methane and quantifying the emission using the release of tracer gas. The validation test showed that even in areas with large...... treatment plants. The PhD study reviewed and evaluated previously used methane measurement methods and found the tracer dispersion method promising. The method uses release of tracer gas and the use of mobile equipment with high analytical sensitivity, to measure the downwind plumes of methane and tracer...... ranged from 10 to 92 kg per hour and was found to change in even short timescales of a few hours. The periods with large emissions correlated with a drop in methane utilization, indicating that emissions came from the digesters tanks or gas storage/use. The measurements indicated that the main emissions...

Measurement of fugitive emissions from gas processing plants in Alberta

Energy Technology Data Exchange (ETDEWEB)

Chambers, A. [Alberta Research Council, Edmonton, AB (Canada)

2004-07-01

This paper presents a new gas visualization camera created to detect leaks. An outline of the device's projected entry into the oil and gas industry was provided, and included: a demonstration of Differential Absorption Light Detection and Ranging (DIAL) and leak cameras to measure and reduce fugitive emissions; a comparison of DIAL measured emissions with estimated emissions; and a review of methods to measure particulate emissions. In addition, a background of gas leak visualisation technology was presented along with an an overview of DIAL and its results from sour gas plants. The results of a survey conducted in 2003 were presented, including leaks identified and repaired as well as a follow up leak survey. An analysis of pre and post-repair hydrocarbon emissions from the Deepcut area revealed a 60 per cent reduction with savings of $140,000 as well as additional savings from reduced carbon emissions. A similar survey conducted in another plant measured emissions from condensate tanks before and after cooler installation as well as from surrounding well sites, quantifying an 80 per cent reduction in methane emissions. Tasks identified for future research concerned particulate emissions and the development of Lidar methods which can currently identify particulates, but are not yet able to quantify them. Other tasks included a complete DIAL data workup and reporting; the quantification of both methane and carbon emissions reduction at a sour gas plant; a comparison of measured emissions with methods that estimate fugitives; and a complete review of particulate measurements. tabs, figs.

Atomic emission spectroscopy for the on-line monitoring of incineration processes

International Nuclear Information System (INIS)

Timmermans, E.A.H.; Groote, F.P.J. de; Jonkers, J.; Gamero, A.; Sola, A.; Mullen, J.J.A.M. van der

2003-01-01

A diagnostic measurement system based on atomic emission spectroscopy has been developed for the purpose of on-line monitoring of hazardous elements in industrial combustion gases. The aim was to construct a setup with a high durability for rough and variable experimental conditions, e.g. a strongly fluctuating gas composition, a high gas temperature and the presence of fly ash and corrosive effluents. Since the setup is primarily intended for the analysis of combustion gases with extremely high concentrations of pollutants, not much effort has been made to achieve low detection limits. It was found that an inductively coupled argon plasma was too sensitive to molecular gas introduction. Therefore, a microwave induced plasma torch, compromising both the demands of a high durability and an effective evaporation and excitation of the analyte was used as excitation source. The analysis system has been installed at an industrial hazardous waste incinerator and successfully tested on combustion gases present above the incineration process. Abundant elements as zinc, lead and sodium could be easily monitored

Stability of emission line clouds in active galactic nuclei

International Nuclear Information System (INIS)

Krinsky, I.S.

1989-01-01

A numerical model was developed for a Quasar Stellar Object (QSO) broad emission line cloud (ELC) imbedded within a confining hot intercloud medium (HIM) for the purpose of studying its stability to perturbations in its temperature and density. A self-consistent model in radiative, pressure and thermal equilibrium is presented. The effect of trapped line radiation pressure is also included with the total pressure (particle plus radiation) held constant. The equilibrium model is found to have regions with radiation pressure exceeding gas pressure. Energy transport includes the effects of an external broken power law continuum and thermal conduction of heat from the HIM. Conduction is found to be unimportant to the total energy budget of the cloud, but is important to the dynamics of the ELC/HIM interface. Independent of the ELC/HIM model, an extension of second order probabilistic radiative transfer that treats the diffuse radiation field as composed of two oppositely directed streams is presented. The high ionization zone of the ELC is found to be unstable to radiatively driven sound waves. Both the external radiation field and the force of trapped line radiation are potential sources for driving the growth of sound waves. The final picture that emerges is that the ELC must be in a constant state of flux

Emission Line Correlations as Diagnostics of Quasar Winds

Science.gov (United States)

Sheldon, Keziah; Richards, Gordon

2018-01-01

We investigate correlations between UV and optical emission line properties for a sample of z~0.5 SDSS (Sloan Digital Sky Survey) quasars that have recently been observed by HST. The sample is designed to be comparable in luminosity to the existing reverberation mapping (RM) sample, but less biased in terms of their "eigenvector 1" properties. We seek to understand the conditions under which high-ionization emission lines become dominated by a wind. Our analysis takes advantage of spectral decomposition through Independent Component Analysis (ICA) and archival UV HST spectroscopy of SDSS quasars. With these data we will clarify the needs for RM analysis of quasars with wind-dominated emission features.

Norwegian gas sales and the impacts on European CO2 emissions

International Nuclear Information System (INIS)

Berg, E.; Boug, P.; Kverndokk, S.

2001-01-01

This paper has studied the impacts on Western European CO 2 emissions of a reduction in Norwegian gas sales. Such impacts are due to changes in energy demand, energy supply, and environmental and political regulations. The gas supply model DYNOPOLY was used to analyse the effects on Russian and Algerian gas exports of a reduction in Norwegian gas supply. The effects on the demand side and the effects of committing to CO 2 targets were analysed using the energy demand model SEEM. If Western European countries commit to their announced CO 2 emissions targets, reduced Norwegian gas sales will have no impact on emissions. The consumption of oil and coal will increase slightly, while the total energy consumption will go down. Also, a reduction in Norwegian gas sales will have only minor impacts on the CO 2 emissions from Western Europe when no emissions regulations are considered

2012 Stakeholder Workshop on Natural Gas in the Inventory of U.S. Greenhouse Gas Emissions and Sinks

Science.gov (United States)

This page describes EPA's September 2012 stakeholder workshop on key aspects of the estimates of greenhouse gas emissions from the natural gas sector in the Inventory of U.S. Greenhouse Gas Emissions and Sinks.

Technology Opportunities to Reduce U.S. Greenhouse Gas Emissions

Energy Technology Data Exchange (ETDEWEB)

National Lab Directors, . .

2001-04-05

The rise in greenhouse gas emissions from fossil fuel combustion and industrial and agricultural activities has aroused international concern about the possible impacts of these emissions on climate. Greenhouse gases--mostly carbon dioxide, some methane, nitrous oxide and other trace gases--are emitted to the atmosphere, enhancing an effect in which heat reflected from the earth's surface is kept from escaping into space, as in a greenhouse. Thus, there is concern that the earth's surface temperature may rise enough to cause global climate change. Approximately 90% of U.S. greenhouse gas emissions from anthropogenic sources come from energy production and use, most of which are a byproduct of the combustion of fossil fuels. On a per capita basis, the United States is one of the world's largest sources of greenhouse gas emissions, comprising 4% of the world's population, yet emitting 23% of the world's greenhouse gases. Emissions in the United States are increasing at around 1.2% annually, and the Energy Information Administration forecasts that emissions levels will continue to increase at this rate in the years ahead if we proceed down the business-as-usual path. President Clinton has presented a two-part challenge for the United States: reduce greenhouse gas emissions and grow the economy. Meeting the challenge will mean that in doing tomorrow's work, we must use energy more efficiently and emit less carbon for the energy expended than we do today. To accomplish these goals, President Clinton proposed on June 26, 1997, that the United States ''invest more in the technologies of the future''. In this report to Secretary of Energy Pena, 47 technology pathways are described that have significant potential to reduce carbon dioxide emissions. The present study was completed before the December 1997 United Nations Framework Convention on Climate Change and is intended to provide a basis to evaluate technology

Modelling combustion reactions for gas flaring and its resulting emissions

Directory of Open Access Journals (Sweden)

O. Saheed Ismail

2016-07-01

Full Text Available Flaring of associated petroleum gas is an age long environmental concern which remains unabated. Flaring of gas maybe a very efficient combustion process especially steam/air assisted flare and more economical than utilization in some oil fields. However, it has serious implications for the environment. This study considered different reaction types and operating conditions for gas flaring. Six combustion equations were generated using the mass balance concept with varying air and combustion efficiency. These equations were coded with a computer program using 12 natural gas samples of different chemical composition and origin to predict the pattern of emission species from gas flaring. The effect of key parameters on the emission output is also shown. CO2, CO, NO, NO2 and SO2 are the anticipated non-hydrocarbon emissions of environmental concern. Results show that the quantity and pattern of these chemical species depended on percentage excess/deficiency of stoichiometric air, natural gas type, reaction type, carbon mass content, impurities, combustion efficiency of the flare system etc. These emissions degrade the environment and human life, so knowing the emission types, pattern and flaring conditions that this study predicts is of paramount importance to governments, environmental agencies and the oil and gas industry.

CO and PAH emissions from engines operating on producer gas

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper

2005-01-01

High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. The standing regulations concerning CO emissions from gas engine based power plants in most EU countries are so ...

Shift and broadening of emission lines in Nd 3: YAG laser crystal ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 6. Shift and broadening of emission lines in Nd3+:YAG laser crystal influenced by input energy. POURMAND SEYED EBRAHIM REZAEI ... Keywords. Nd3+:YAG crystal; heat generation; three-level emission lines; four-level emission lines; input energy.

Mapping low- and high-density clouds in astrophysical nebulae by imaging forbidden line emission

Science.gov (United States)

Steiner, J. E.; Menezes, R. B.; Ricci, T. V.; Oliveira, A. S.

2009-06-01

Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden lines into images of emission from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive lines as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of lines in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair line intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it `the ld/hd imaging method'. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States); the Science and Technology Facilities Council (United Kingdom); the National Research Council (Canada), CONICYT (Chile); the Australian Research Council (Australia); Ministério da Ciência e Tecnologia (Brazil) and Secretaria de Ciencia y Tecnologia (Argentina). E-mail: steiner@astro.iag.usp.br

Life cycle greenhouse gas emissions from U.S. liquefied natural gas exports: implications for end uses.

Science.gov (United States)

Abrahams, Leslie S; Samaras, Constantine; Griffin, W Michael; Matthews, H Scott

2015-03-03

This study analyzes how incremental U.S. liquefied natural gas (LNG) exports affect global greenhouse gas (GHG) emissions. We find that exported U.S. LNG has mean precombustion emissions of 37 g CO2-equiv/MJ when regasified in Europe and Asia. Shipping emissions of LNG exported from U.S. ports to Asian and European markets account for only 3.5-5.5% of precombustion life cycle emissions, hence shipping distance is not a major driver of GHGs. A scenario-based analysis addressing how potential end uses (electricity and industrial heating) and displacement of existing fuels (coal and Russian natural gas) affect GHG emissions shows the mean emissions for electricity generation using U.S. exported LNG were 655 g CO2-equiv/kWh (with a 90% confidence interval of 562-770), an 11% increase over U.S. natural gas electricity generation. Mean emissions from industrial heating were 104 g CO2-equiv/MJ (90% CI: 87-123). By displacing coal, LNG saves 550 g CO2-equiv per kWh of electricity and 20 g per MJ of heat. LNG saves GHGs under upstream fugitive emissions rates up to 9% and 5% for electricity and heating, respectively. GHG reductions were found if Russian pipeline natural gas was displaced for electricity and heating use regardless of GWP, as long as U.S. fugitive emission rates remain below the estimated 5-7% rate of Russian gas. However, from a country specific carbon accounting perspective, there is an imbalance in accrued social costs and benefits. Assuming a mean social cost of carbon of $49/metric ton, mean global savings from U.S. LNG displacement of coal for electricity generation are $1.50 per thousand cubic feet (Mcf) of gaseous natural gas exported as LNG ($.028/kWh). Conversely, the U.S. carbon cost of exporting the LNG is $1.80/Mcf ($.013/kWh), or $0.50-$5.50/Mcf across the range of potential discount rates. This spatial shift in embodied carbon emissions is important to consider in national interest estimates for LNG exports.

MID-INFRARED PROPERTIES OF THE SWIFT BURST ALERT TELESCOPE ACTIVE GALACTIC NUCLEI SAMPLE OF THE LOCAL UNIVERSE. I. EMISSION-LINE DIAGNOSTICS

International Nuclear Information System (INIS)

Weaver, K. A.; Melendez, M.; Mushotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth, E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; Winter, L. M.; Armus, L.

2010-01-01

We compare mid-infrared emission-line properties from high-resolution Spitzer spectra of a hard X-ray (14-195 keV) selected sample of nearby (z < 0.05) active galactic nuclei (AGNs) detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared emission lines, [O IV] 25.89 μm, [Ne II] 12.81 μm, [Ne III] 15.56 μm, and [Ne V] 14.32/24.32 μm, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations; however, six newly discovered BAT AGNs are under-luminous in [O IV], most likely the result of dust extinction in the host galaxy. The overall tightness of the mid-infrared correlations and BAT fluxes and luminosities suggests that the emission lines primarily arise in gas ionized by the AGNs. We also compare the mid-infrared emission lines in the BAT AGNs with those from published studies of ULIRGs, Palomar-Green quasars, star-forming galaxies, and LINERs. We find that the BAT AGN sample falls into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] ratios. These line ratios are lower in sources that have been previously classified in the mid-infrared/optical as AGNs than those found for the BAT AGNs, suggesting that, in our X-ray selected sample, the AGNs represent the main contribution to the observed line emission. These ratios represent a new emission line diagnostic for distinguishing between AGNs and star-forming galaxies.

HERSCHEL-PACS OBSERVATIONS OF FAR-IR CO LINE EMISSION IN NGC 1068: HIGHLY EXCITED MOLECULAR GAS IN THE CIRCUMNUCLEAR DISK

Energy Technology Data Exchange (ETDEWEB)

Hailey-Dunsheath, S.; Sturm, E.; Gracia-Carpio, J.; Davies, R.; Poglitsch, A.; Contursi, A.; Genzel, R.; Lutz, D.; Tacconi, L.; De Jong, J. A. [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, D-85741 Garching (Germany); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Ave SW, Washington, DC 20375 (United States); Sternberg, A.; Mark, D. [Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv 69978 (Israel); Gonzalez-Alfonso, E. [Departamento de Fisica, Universidad de Alcala de Henares, 28871 Alcala de Henares, Madrid (Spain); Veilleux, S. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Verma, A., E-mail: shd@astro.caltech.edu [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom)

2012-08-10

We report the detection of far-IR CO rotational emission from the prototypical Seyfert 2 galaxy NGC 1068. Using Herschel-PACS, we have detected 11 transitions in the J{sub upper} = 14-30 (E{sub upper}/k{sub B} = 580-2565 K) range, all of which are consistent with arising from within the central 10'' (700 pc). The detected transitions are modeled as arising from two different components: a moderate-excitation (ME) component close to the galaxy systemic velocity and a high-excitation (HE) component that is blueshifted by {approx}80 km s{sup -1}. We employ a large velocity gradient model and derive n{sub H2} {approx} 10{sup 5.6} cm{sup -3}, T{sub kin} {approx} 170 K, and M{sub H2} {approx} 10{sup 6.7} M{sub Sun} for the ME component and n{sub H2} {approx} 10{sup 6.4} cm{sup -3}, T{sub kin} {approx} 570 K, and M{sub H2} {approx} 10{sup 5.6} M{sub Sun} for the HE component, although for both components the uncertainties in the density and mass are {+-}(0.6-0.9) dex. Both components arise from denser and possibly warmer gas than traced by low-J CO transitions, and the ME component likely makes a significant contribution to the mass budget in the nuclear region. We compare the CO line profiles with those of other molecular tracers observed at higher spatial and spectral resolution and find that the ME transitions are consistent with these lines arising in the {approx}200 pc diameter ring of material traced by H{sub 2} 1-0 S(1) observations. The blueshift of the HE lines may also be consistent with the bluest regions of this H{sub 2} ring, but a better kinematic match is found with a clump of infalling gas {approx}40 pc north of the active galactic nucleus (AGN). We consider potential heating mechanisms and conclude that X-ray- or shock heating of both components is viable, while far-UV heating is unlikely. We discuss the prospects of placing the HE component near the AGN and conclude that while the moderate thermal pressure precludes an association with the

Accounting for Greenhouse Gas Emissions from Reservoirs

Science.gov (United States)

Nearly three decades of research has demonstrated that the impoundment of rivers and the flooding of terrestrial ecosystems behind dams can increase rates of greenhouse gas emission, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes ...

Greenhouse Gas Emissions Trading for the Transport Sector

International Nuclear Information System (INIS)

Holmgren, Kristina; Belhaj, Mohammed; Gode, Jenny; Saernholm, Erik; Zetterberg, Lars; Aahman, Markus

2006-12-01

In this study we have analysed different options to apply emissions trading for greenhouse gas emissions to the transport sector. The main focus has been on the EU transport sector and the possibility to include it in the current EU ETS in the trading period beginning in 2013. The purpose was to study how different alternatives will affect different actors. Focus has been on three sub-sectors; road transport, aviation and shipping. The railway sector has only been treated on a general level. The study includes the following three parts: 1. An economic analysis of the consequences of greenhouse gas emissions trading for the transport sector including an analysis of how the total cost for reaching an emission target will be affected by an integrated emissions trading system for the transport sector and the industry (currently included sectors) compared to separate systems for the sectors, 2. An analysis of design possibilities for the different sub-sectors. Discussion of positive and negative aspects with different choices of design parameters, such as trading entity, covered greenhouse gases, allocation of emission allowances and monitoring systems, 3. Examination of the acceptance among different actors for different options of using greenhouse gas emissions trading in the transport sector. When setting up an emissions trading scheme there are a number of design parameters that have to be analysed in order to find an appropriate system, with limited administrative and transaction costs and as small distortions as possible to competitiveness

Classification spectra of Sanduleak and Stephenson emission-line stars

International Nuclear Information System (INIS)

Allen, D.A.

1978-01-01

Low dispersion slit spectra of 89 emission-line stars are described; these stars were originally located and classified by Sanduleak and Stephenson in an objective-prism survey. The new data broadly confirm the classification scheme adopted by Sanduleak and Stephenson. In particular most of the large number of symbiotic stars they classified have been confirmed and others found. Many of these contain strong, broad emission bands in their red spectra. Two new Wolf-Rayet stars, one new planetary nebula and two new bipolar reflection nebulae involving hidden emission-line stars have been found. (author)

Classification spectra of Sanduleak and Stephenson emission-line stars

Energy Technology Data Exchange (ETDEWEB)

Allen, D A [Anglo-Australian Observatory, Epping (Australia)

1978-09-01

Low dispersion slit spectra of 89 emission-line stars are described; these stars were originally located and classified by Sanduleak and Stephenson in an objective-prism survey. The new data broadly confirm the classification scheme adopted by Sanduleak and Stephenson. In particular most of the large number of symbiotic stars they classified have been confirmed and others found. Many of these contain strong, broad emission bands in their red spectra. Two new Wolf-Rayet stars, one new planetary nebula and two new bipolar reflection nebulae involving hidden emission-line stars have been found.

21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class II...

The Global Potential for Drastic Reduction of Greenhouse Gas Emissions. On the interaction between technological innovation, sustainable growth and lifestyle development

Energy Technology Data Exchange (ETDEWEB)

Bruggink, J.J.C. [ECN Policy Studies, Petten (Netherlands)

2000-03-01

Technological innovation is often viewed as the key to drastic reduction of greenhouse gas emissions, and rightly so. In fact there are already a number of technologies on the shelf that could fix global warming problems in no time. The trouble is that few people in the developing world can afford them or that few people in the developed world find them acceptable. Most people are simply too poor or too critical. So what are the decisive fault lines that should distinguish a climate-friendly next century from a climate-hostile past? First, only a more equal world will make drastic reduction of greenhouse gas emissions affordable. Secondly, mankind will have to accept that in addition to technological innovation, drastic reduction of greenhouse gas emissions depends on lifestyle innovation.

The broad component of hydrogen emission lines in nuclei of Seyfert galaxies: Comments on a charge exchange model

International Nuclear Information System (INIS)

Katz, A.

1975-01-01

A model to account for the broad hydrogen line emission from the nuclei of Seyfert galaxies based on charge exchange and collisional processes, as proposed by Ptak and Stoner, is investigated. The model consists of a source of fast (E approx. 10 5 eV) protons streaming through a medium of quiescent gas. One of the major problems that results from such a model concerns the strong narrow hydrogen line core that would be produced, in direct conflict with the observations. The lines cannot arise from gas arranged throughout a spherical volume surrounding the source of the fast particles because the fast protons would produce far more ionizations than the possible number of recombinations. A very dense shell source of less than 1 AU in thickness and at least several tens of parsecs in radius must be invoked to reproduce the asymmetric broad profiles observed. There must be absorption throughout the center of the shell to account for the line profiles. The gas cannot be arranged in dense clumps throughout a large volume because momentum exchange of the gas with the primary particles would quickly accelerate any clumps. The energy balance and energy requirements of such a model are investigated, and it is found that an energy equal to or greater than the total luminosity of most Seyfert galaxies is required to produce the hydrogen line alone. The gas must be mostly neutral and den []e (N approx. 10 7 ) if a reasonable temperature is to be maintained

Revised emission factors for gas engines including start/stop emissions

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Malene; Boll Illerup, J.; Birr-Petersen, K.

2008-06-15

Liberalisation of the electricity market has led to Danish gas engine plants increasingly converting to the spot and regulating power markets. In order to offer regulating power, plants need to be able to start and stop the engines at the plants quickly. The liberalisation causes a considerable change of operation practice of the engines e.g. less full load operation hours /year. The project provides an inventory determining the scale of the emissions during the start and stop sequence as well as proposals for engine modifications aimed at reducing start/stop emissions. This report includes calculation of emission factors as well as an inventory of total emissions and reduction potentials. (au)

Atmospheric emissions from the upstream oil and gas industry

International Nuclear Information System (INIS)

Taylor, B.G.S.

1994-01-01

The results are presented of a study set up to determine the nature and levels of atmospheric emissions resulting from United Kingdom oil and gas exploration and production activities. The study was commissioned by the UK Offshore Operators Association. Emissions by the upstream oil and gas industry of common pollutants, such as carbon monoxide, sulphur dioxide and nitrous oxide, and ozone depletion chemicals were shown in each case to be less than 1% of total UK emissions. Greenhouse gas emissions in the industry arise mainly from production operations with a small but significant contribution from onshore activities. Carbon dioxide is the major component followed in descending order by nitrogen oxides, methane and volatile organic compounds. In 1991, these emissions formed 3.2%, 4.6%, 2.9% and 2.8% of the UK totals respectively; overall this represented only about 3% of UK global warming emissions. The evidence of this study illustrates that the industry, which produces 67% of the UK's primary energy, is successfully managing its operations in an environmentally responsible way. (3 figures, 3 tables) (UK)

Predicting emissions from oil and gas operations in the Uinta Basin, Utah.

Science.gov (United States)

Wilkey, Jonathan; Kelly, Kerry; Jaramillo, Isabel Cristina; Spinti, Jennifer; Ring, Terry; Hogue, Michael; Pasqualini, Donatella

2016-05-01

In this study, emissions of ozone precursors from oil and gas operations in Utah's Uinta Basin are predicted (with uncertainty estimates) from 2015-2019 using a Monte-Carlo model of (a) drilling and production activity, and (b) emission factors. Cross-validation tests against actual drilling and production data from 2010-2014 show that the model can accurately predict both types of activities, returning median results that are within 5% of actual values for drilling, 0.1% for oil production, and 4% for gas production. A variety of one-time (drilling) and ongoing (oil and gas production) emission factors for greenhouse gases, methane, and volatile organic compounds (VOCs) are applied to the predicted oil and gas operations. Based on the range of emission factor values reported in the literature, emissions from well completions are the most significant source of emissions, followed by gas transmission and production. We estimate that the annual average VOC emissions rate for the oil and gas industry over the 2010-2015 time period was 44.2E+06 (mean) ± 12.8E+06 (standard deviation) kg VOCs per year (with all applicable emissions reductions). On the same basis, over the 2015-2019 period annual average VOC emissions from oil and gas operations are expected to drop 45% to 24.2E+06 ± 3.43E+06 kg VOCs per year, due to decreases in drilling activity and tighter emission standards. This study improves upon previous methods for estimating emissions of ozone precursors from oil and gas operations in Utah's Uinta Basin by tracking one-time and ongoing emission events on a well-by-well basis. The proposed method has proven highly accurate at predicting drilling and production activity and includes uncertainty estimates to describe the range of potential emissions inventory outcomes. If similar input data are available in other oil and gas producing regions, then the method developed here could be applied to those regions as well.

Country-Level Life Cycle Assessment of Greenhouse Gas Emissions from Liquefied Natural Gas Trade for Electricity Generation.

Science.gov (United States)

Kasumu, Adebola S; Li, Vivian; Coleman, James W; Liendo, Jeanne; Jordaan, Sarah M

2018-02-20

In the determination of the net impact of liquefied natural gas (LNG) on greenhouse gas emissions, life cycle assessments (LCA) of electricity generation have yet to combine the effects of transport distances between exporting and importing countries, country-level infrastructure in importing countries, and the fuel sources displaced in importing countries. To address this, we conduct a LCA of electricity generated from LNG export from British Columbia, Canada with a three-step approach: (1) a review of viable electricity generation markets for LNG, (2) the development of results for greenhouse gas emissions that account for transport to importing nations as well as the infrastructure required for power generation and delivery, and (3) emissions displacement scenarios to test assumptions about what electricity is being displaced in the importing nation. Results show that while the ultimate magnitude of the greenhouse gas emissions associated with natural gas production systems is still unknown, life cycle greenhouse gas emissions depend on country-level infrastructure (specifically, the efficiency of the generation fleet, transmission and distribution losses and LNG ocean transport distances) as well as the assumptions on what is displaced in the domestic electricity generation mix. Exogenous events such as the Fukushima nuclear disaster have unanticipated effects on the emissions displacement results. We highlight national regulations, environmental policies, and multilateral agreements that could play a role in mitigating emissions.

Analysis of carbon dioxide emission of gas fuelled cogeneration plant

International Nuclear Information System (INIS)

Nordin, Adzuieen; Amin, M; Majid, A

2013-01-01

Gas turbines are widely used for power generation. In cogeneration system, the gas turbine generates electricity and the exhaust heat from the gas turbine is used to generate steam or chilled water. Besides enhancing the efficiency of the system, the process assists in reducing the emission of CO 2 to the environment. This study analyzes the amount of CO 2 emission by Universiti Teknologi Petronas gas fuelled cogeneration system using energy balance equations. The results indicate that the cogeneration system reduces the CO 2 emission to the environment by 60%. This finding could encourage the power plant owners to install heat recovery systems to their respective plants

Analysis of carbon dioxide emission of gas fuelled cogeneration plant

Science.gov (United States)

Nordin, Adzuieen; Amin, M.; Majid, A.

2013-12-01

Gas turbines are widely used for power generation. In cogeneration system, the gas turbine generates electricity and the exhaust heat from the gas turbine is used to generate steam or chilled water. Besides enhancing the efficiency of the system, the process assists in reducing the emission of CO2 to the environment. This study analyzes the amount of CO2 emission by Universiti Teknologi Petronas gas fuelled cogeneration system using energy balance equations. The results indicate that the cogeneration system reduces the CO2 emission to the environment by 60%. This finding could encourage the power plant owners to install heat recovery systems to their respective plants.

Estimating greenhouse gas emissions of European cities — Modeling emissions with only one spatial and one socioeconomic variable

International Nuclear Information System (INIS)

Baur, Albert H.; Lauf, Steffen; Förster, Michael; Kleinschmit, Birgit

2015-01-01

Substantive and concerted action is needed to mitigate climate change. However, international negotiations struggle to adopt ambitious legislation and to anticipate more climate-friendly developments. Thus, stronger actions are needed from other players. Cities, being greenhouse gas emission centers, play a key role in promoting the climate change mitigation movement by becoming hubs for smart and low-carbon lifestyles. In this context, a stronger linkage between greenhouse gas emissions and urban development and policy-making seems promising. Therefore, simple approaches are needed to objectively identify crucial emission drivers for deriving appropriate emission reduction strategies. In analyzing 44 European cities, the authors investigate possible socioeconomic and spatial determinants of urban greenhouse gas emissions. Multiple statistical analyses reveal that the average household size and the edge density of discontinuous dense urban fabric explain up to 86% of the total variance of greenhouse gas emissions of EU cities (when controlled for varying electricity carbon intensities). Finally, based on these findings, a multiple regression model is presented to determine greenhouse gas emissions. It is independently evaluated with ten further EU cities. The reliance on only two indicators shows that the model can be easily applied in addressing important greenhouse gas emission sources of European urbanites, when varying power generations are considered. This knowledge can help cities develop adequate climate change mitigation strategies and promote respective policies on the EU or the regional level. The results can further be used to derive first estimates of urban greenhouse gas emissions, if no other analyses are available. - Highlights: • Two variables determine urban GHG emissions in Europe, assuming equal power generation. • Household size, inner-urban compactness and power generation drive urban GHG emissions. • Climate policies should consider

Estimating greenhouse gas emissions of European cities — Modeling emissions with only one spatial and one socioeconomic variable

Energy Technology Data Exchange (ETDEWEB)

Baur, Albert H., E-mail: Albert.H.Baur@campus.tu-berlin.de; Lauf, Steffen; Förster, Michael; Kleinschmit, Birgit

2015-07-01

Substantive and concerted action is needed to mitigate climate change. However, international negotiations struggle to adopt ambitious legislation and to anticipate more climate-friendly developments. Thus, stronger actions are needed from other players. Cities, being greenhouse gas emission centers, play a key role in promoting the climate change mitigation movement by becoming hubs for smart and low-carbon lifestyles. In this context, a stronger linkage between greenhouse gas emissions and urban development and policy-making seems promising. Therefore, simple approaches are needed to objectively identify crucial emission drivers for deriving appropriate emission reduction strategies. In analyzing 44 European cities, the authors investigate possible socioeconomic and spatial determinants of urban greenhouse gas emissions. Multiple statistical analyses reveal that the average household size and the edge density of discontinuous dense urban fabric explain up to 86% of the total variance of greenhouse gas emissions of EU cities (when controlled for varying electricity carbon intensities). Finally, based on these findings, a multiple regression model is presented to determine greenhouse gas emissions. It is independently evaluated with ten further EU cities. The reliance on only two indicators shows that the model can be easily applied in addressing important greenhouse gas emission sources of European urbanites, when varying power generations are considered. This knowledge can help cities develop adequate climate change mitigation strategies and promote respective policies on the EU or the regional level. The results can further be used to derive first estimates of urban greenhouse gas emissions, if no other analyses are available. - Highlights: • Two variables determine urban GHG emissions in Europe, assuming equal power generation. • Household size, inner-urban compactness and power generation drive urban GHG emissions. • Climate policies should consider

OPIC Greenhouse Gas Emissions Analysis Details

Data.gov (United States)

Overseas Private Investment Corporation — Summary project inventory with independent analysis to quantify the greenhouse gas ("GHG") emissions directly attributable to projects to which the Overseas Private...

Modeling Greenhouse Gas Emissions from Enteric Fermentation

NARCIS (Netherlands)

Kebreab, E.; Tedeschi, L.; Dijkstra, J.; Ellis, J.L.; Bannink, A.; France, J.

2016-01-01

Livestock directly contribute to greenhouse gas (GHG) emissions mainly through methane (CH4) and nitrous oxide (N2O) emissions. For cost and practicality reasons, quantification of GHG has been through development of various types of mathematical models. This chapter addresses the utility and

Does the Swedish consumer's choice of food influence greenhouse gas emissions?

International Nuclear Information System (INIS)

Wallen, Anna; Brandt, Nils; Wennersten, Ronald

2004-01-01

Consumer's choice of food can influence the environment. In Sweden, in common with many other countries, consumers need to be given information so they can make environmentally informed shopping choices. However, what is the most advantageous dietary choice to lower greenhouse emissions? This study investigates the greenhouse gas emissions associated with food production for food consumed in Sweden annually. Specifically, this study compares greenhouse gas emissions associated with a nutritionally and environmentally sustainable diet with the average consumption of food in Sweden 1999. The study concludes that the change in energy use and greenhouse gas emission associated with this change of diet is negligible. Lowering greenhouse gas emissions by changing food production processes results in more profound changes than teaching consumers to make environmentally correct choices. There is a basic need for a reduction or a replacement of the use of fossil fuels to produce and distribute our food in order to reach any significant reduction in the emission of greenhouse gases. Swedish agricultural policy does not provide ways to reduce greenhouse gas emissions. In Sweden therefore there is an immediate need to design policy instruments with the primary aim of reducing the greenhouse effect

Greenhouse gas emission measurement and economic analysis of Iran natural gas fired power plants

International Nuclear Information System (INIS)

Shahsavari Alavijeh, H.; Kiyoumarsioskouei, A.; Asheri, M.H.; Naemi, S.; Shahsavari Alavije, H.; Basirat Tabrizi, H.

2013-01-01

This study attempts to examine the natural gas fired power plants in Iran. The required data from natural gas fired power plants were gathered during 2008. The characteristics of thirty two gas turbine power plants and twenty steam power plants have been measured. Their emission factor values were then compared with the standards of Energy Protection Agency, Euro Union and World Bank. Emission factors of gas turbine and steam power plants show that gas turbine power plants have a better performance than steam power plants. For economic analysis, fuel consumption and environmental damages caused by the emitted pollutants are considered as cost functions; and electricity sales revenue are taken as benefit functions. All of these functions have been obtained according to the capacity factor. Total revenue functions show that gas turbine and steam power plants are economically efficient at 98.15% and 90.89% of capacity factor, respectively; this indicates that long operating years of power plants leads to reduction of optimum capacity factor. The stated method could be implemented to assess the economic status of a country’s power plants where as efficient capacity factor close to one means that power plant works in much better condition. - Highlights: • CO 2 and NO x emissions of Iran natural gas fired power plants have been studied. • CO 2 and NO x emission factors are compared with EPA, EU and World Bank standards. • Costs and benefit as economic functions are obtained according to capacity factor. • Maximum economic profit is obtained for gas turbine and steam power plants. • Investment in CO 2 reduction is recommended instead of investment in NO x reduction

Unregulated greenhouse gas and ammonia emissions from current technology heavy-duty vehicles.

Science.gov (United States)

Thiruvengadam, Arvind; Besch, Marc; Carder, Daniel; Oshinuga, Adewale; Pasek, Randall; Hogo, Henry; Gautam, Mridul

2016-11-01

The study presents the measurement of carbonyl, BTEX (benzene, toluene, ethyl benzene, and xylene), ammonia, elemental/organic carbon (EC/OC), and greenhouse gas emissions from modern heavy-duty diesel and natural gas vehicles. Vehicles from different vocations that included goods movement, refuse trucks, and transit buses were tested on driving cycles representative of their duty cycle. The natural gas vehicle technologies included the stoichiometric engine platform equipped with a three-way catalyst and a diesel-like dual-fuel high-pressure direct-injection technology equipped with a diesel particulate filter (DPF) and a selective catalytic reduction (SCR). The diesel vehicles were equipped with a DPF and SCR. Results of the study show that the BTEX emissions were below detection limits for both diesel and natural gas vehicles, while carbonyl emissions were observed during cold start and low-temperature operations of the natural gas vehicles. Ammonia emissions of about 1 g/mile were observed from the stoichiometric natural gas vehicles equipped with TWC over all the driving cycles. The tailpipe GWP of the stoichiometric natural gas goods movement application was 7% lower than DPF and SCR equipped diesel. In the case of a refuse truck application the stoichiometric natural gas engine exhibited 22% lower GWP than a diesel vehicle. Tailpipe methane emissions contribute to less than 6% of the total GHG emissions. Modern heavy-duty diesel and natural gas engines are equipped with multiple after-treatment systems and complex control strategies aimed at meeting both the performance standards for the end user and meeting stringent U.S. Environmental Protection Agency (EPA) emissions regulation. Compared to older technology diesel and natural gas engines, modern engines and after-treatment technology have reduced unregulated emissions to levels close to detection limits. However, brief periods of inefficiencies related to low exhaust thermal energy have been shown to

A global gas flaring black carbon emission rate dataset from 1994 to 2012

Science.gov (United States)

Huang, Kan; Fu, Joshua S.

2016-11-01

Global flaring of associated petroleum gas is a potential emission source of particulate matters (PM) and could be notable in some specific regions that are in urgent need of mitigation. PM emitted from gas flaring is mainly in the form of black carbon (BC), which is a strong short-lived climate forcer. However, BC from gas flaring has been neglected in most global/regional emission inventories and is rarely considered in climate modeling. Here we present a global gas flaring BC emission rate dataset for the period 1994-2012 in a machine-readable format. We develop a region-dependent gas flaring BC emission factor database based on the chemical compositions of associated petroleum gas at various oil fields. Gas flaring BC emission rates are estimated using this emission factor database and flaring volumes retrieved from satellite imagery. Evaluation using a chemical transport model suggests that consideration of gas flaring emissions can improve model performance. This dataset will benefit and inform a broad range of research topics, e.g., carbon budget, air quality/climate modeling, and environmental/human exposure.

The Impact of a Potential Shale Gas Development in Germany and the United Kingdom on Pollutant and Greenhouse Gas Emissions

Science.gov (United States)

Weger, L.; Cremonese, L.; Bartels, M. P.; Butler, T. M.

2016-12-01

Several European countries with domestic shale gas reserves are considering extracting this natural gas resource to complement their energy transition agenda. Natural gas, which produces lower CO2 emissions upon combustion compared to coal or oil, has the potential to serve as a bridge in the transition from fossil fuels to renewables. However, the generation of shale gas leads to emissions of CH4 and pollutants such as PM, NOx and VOCs, which in turn impact climate as well as local and regional air quality. In this study, we explore the impact of a potential shale gas development in Europe, specifically in Germany and the United Kingdom, on emissions of greenhouse gases and pollutants. In order to investigate the effect on emissions, we first estimate a range of wells drilled per year and production volume for the two countries under examination based on available geological information and on regional infrastructural and economic limitations. Subsequently we assign activity data and emissions factors to the well development, gas production and processing stages of shale gas generation to enable emissions quantification. We then define emissions scenarios to explore different storylines of potential shale gas development, including low emissions (high level of regulation), high emissions (low level of regulation) and middle emissions scenarios, which influence fleet make-up, emission factor and activity data choices for emissions quantification. The aim of this work is to highlight important variables and their ranges, to promote discussion and communication of potential impacts, and to construct possible visions for a future shale gas development in the two study countries. In a follow-up study, the impact of pollutant emissions from these scenarios on air quality will be explored using the Weather Research and Forecasting model with chemistry (WRF-Chem) model.

The EU Greenhouse Gas Emissions Trading Scheme

NARCIS (Netherlands)

Woerdman, Edwin; Woerdman, Edwin; Roggenkamp, Martha; Holwerda, Marijn

2015-01-01

This chapter explains how greenhouse gas emissions trading works, provides the essentials of the Directive on the European Union Emissions Trading Scheme (EU ETS) and summarizes the main implementation problems of the EU ETS. In addition, a law and economics approach is used to discuss the dilemmas

Australia’s Consumption-based Greenhouse Gas Emissions

DEFF Research Database (Denmark)

Levitt, Clinton J.; Saaby, Morten; Sørensen, Anders

2017-01-01

We use data from the World Input-Output Database in a multiregional input–output model to analyse Australian consumption-based greenhouse gas emissions for the years 1995 to 2009. We find that the emission content of Australian macroeconomic activity has changed over the 15-year period. Consumption...

Wellbeing impacts of city policies for reducing greenhouse gas emissions

DEFF Research Database (Denmark)

Hiscock, Rosemary; Mudu, Pierpaolo; Braubach, Matthias

2014-01-01

To mitigate climate change, city authorities are developing policies in areas such as transportation, housing and energy use, to reduce greenhouse gas emissions. In addition to their effects on greenhouse gas emissions, these policies are likely to have consequences for the wellbeing...... and subjective aspects which can be measured quantitatively; our review of measures informs the development of a theoretical model linking wellbeing to policies which cities use to reduce greenhouse gas emissions. Finally, we discuss the extent to which the links proposed in the conceptual model are supported...

Leveling the playing field of transportation fuels: Accounting for indirect emissions of natural gas

International Nuclear Information System (INIS)

Sexton, Steven; Eyer, Jonathan

2016-01-01

Natural gas transportation fuels are credited in prior studies with greenhouse gas emissions savings relative to petroleum-based fuels and relative to the total emissions of biofuels. These analyses, however, overlook a source of potentially large indirect emissions from natural gas transportation fuels, namely the emissions from incremental coal-fired generation caused by price-induced substitutions away from natural-gas-fired electricity generation. Because coal-fired generation emits substantially more greenhouse gases and criteria air pollutants than natural-gas-fired generation, this indirect coal-use change effect diminishes potential emissions savings from natural gas transportation fuels. Estimates from a parameterized multi-market model suggest the indirect coal-use change effect rivals in magnitude the indirect land-use change effect of biofuels and renders natural gas fuels as carbon intensive as petroleum fuels. - Highlights: •Natural gas used in transport causes indirect emissions in the electricity sector. •These emissions result from increased coal use in electricity generation. •They rival in magnitude indirect land use change (ILUC) emissions of biofuels. •Natural gas fuels are estimated to be as carbon intensive as the petroleum fuels. •Policy ignores indirect emissions from natural gas.

Effects of nitrogen fertilizer application on greenhouse gas emissions and economics of corn production.

Science.gov (United States)

Kim, Seungdo; Dale, Bruce E

2008-08-15

Nitrogen fertilizer plays an important role in corn cultivation in terms of both economic and environmental aspects. Nitrogen fertilizer positively affects corn yield and the soil organic carbon level, but it also has negative environmental effects through nitrogen-related emissions from soil (e.g., N20, NOx, NO3(-) leaching, etc.). Effects of nitrogen fertilizer on greenhouse gas emissions associated with corn grain are investigated via life cycle assessment. Ecoefficiency analysis is also used to determine an economically and environmentally optimal nitrogen application rate (NAR). The ecoefficiency index in this study is defined as the ratio of economic return due to nitrogen fertilizer to the greenhouse gas emissions of corn cultivation. Greenhouse gas emissions associated with corn grain decrease as NAR increases at a lower NAR until a minimum greenhouse gas emission level is reached because corn yield and soil organic carbon level increase with NAR. Further increasing NAR after a minimum greenhouse gas emission level raises greenhouse gas emissions associated with corn grain. Increased greenhouse gas emissions of corn grain due to nitrous oxide emissions from soil are much higher than reductions of greenhouse gas emissions of corn grain due to corn yield and changes in soil organic carbon levels at a higher NAR. Thus, there exists an environmentally optimal NAR in terms of greenhouse gas emissions. The trends of the ecoefficiency index are similar to those of economic return to nitrogen and greenhouse gas emissions associated with corn grain. Therefore, an appropriate NAR could enhance profitability as well as reduce greenhouse gas emissions associated with corn grain.

Methane Emissions from Natural Gas in the Urban Region of Boston, Massachusetts

Science.gov (United States)

McKain, K.; Down, A.; Raciti, S. M.; Budney, J.; Hutyra, L.; Floerchinger, C. R.; Herndon, S. C.; Zahniser, M. S.; Nehrkorn, T.; Jackson, R. B.; Phillips, N. G.; Wofsy, S. C.

2014-12-01

Methane emissions from the natural gas supply chain must be quantified to assess environmental impacts of natural gas and to develop emission reduction strategies. We report natural gas emission rates for one year in the urban region of Boston, MA, using an atmospheric measurement and modeling framework. Continuous methane observations from four stations are combined with a high-resolution transport model to quantify the regional average emission rate, 20.6 ± 1.7 (95 % CI) g CH4 m-2 yr-1. Simultaneous observations of atmospheric ethane, compared with the ethane to methane ratio in pipeline gas, demonstrate that natural gas accounted for 58 - 100 % of methane emissions, depending on season. Using government statistics and geospatial data on energy consumption, we estimate the fractional loss rate to the atmosphere from all downstream components of the natural gas system, including transmission, distribution, and end-use, was 2.9 ± 0.3 % in the Boston urban region, compared to 1.1 % inferred by the Massachusetts greenhouse gas inventory.

Cogeneration, renewables and reducing greenhouse gas emissions

International Nuclear Information System (INIS)

Naughten, B.; Dlugosz, J.

1996-01-01

The MENSA model is used to assess the potential role of cogeneration and selected new renewable energy technologies in cost-effectively reducing Greenhouse gas emissions. The model framework for analyzing these issues is introduced, together with an account of relevant aspects of its application. In the discussion of selected new renewable energy technologies, it is shown how microeconomic reform may encourage these technologies and fuels, and thereby reduce sector wide carbon dioxide emissions. Policy scenarios modelled are described and the simulation results are presented. Certain interventions in microeconomic reform may result in economic benefits while also reducing emissions: no regrets' opportunities. Some renewable energy technologies are also shown to be cost-effective in the event that targets and timetables for reducing Greenhouse gas emissions are imposed. However, ad hoc interventions in support of particular renewables options are unlikely to be consistent with a least cost approach to achieving environmental objectives. (author). 5 tabs., 5 figs., 21 refs

Generation of the line radiation of argon added to DT gas in Iskra-5 experiments

International Nuclear Information System (INIS)

Bel'kov, S.A.; Bessarab, A.V.; Veselov, A.V.; Gaidash, V.A.; Dolgoleva, G.V.; Zhidkov, N.V.; Izgorodin, V.M.; Kirillov, G.A.; Kochemasov, G.G.; Litvin, D.N.; Martynenko, S.P.; Mitrofanov, E.I.; Murugov, V.M.; Mkhitar'yan, L.S.; Petrov, S.I.; Pinegin, A.V.; Punin, V.T.; Suslov, N.A.

1998-01-01

The first experiments measuring the density of a compressed deuterium and tritium mixture in microtargets of indirect irradiation (x-ray targets) were performed at the Iskra-5 facility. The density was determined according to the broadening of the lines of hydrogen- and helium-like argon added to the DT gas as a diagnostics material. A series of three experiments was performed with x-ray targets in which the central capsule filled with a DT+Ar mixture over a range of shell thicknesses. In two of the experiments, argon emission spectra were recorded and the density of the compressed gas was determined. For a microtarget approximately 280 μm in diameter with a wall approximately 7 μm thick, an analysis of the experimental results yielded an estimated density in the compressed gas of ∼1 g/cm 3 . Gas-dynamic calculations using the SNDA (spectral nonequilibrium diffusion with absorption) program show that argon emission takes place just after reaching maximum temperature, but much sooner than maximum compression. The results of a calculation for an experiment with low relative Ar concentration are in overall agreement with the experimental data. Additional investigations are needed to interpret experiments at a relatively high concentration

Mitigating greenhouse gas emissions: Voluntary reporting

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-10-01

The Voluntary Reporting Program, developed pursuant to Section 1605(b) of the Energy Policy Act of 1992, permits corporations, government agencies, households, and voluntary organizations to report on their emissions of greenhouse gases, and on actions taken that have reduced or avoided emissions or sequestered carbon, to the Energy Information Administration (EIA). This, the second annual report of the Voluntary Reporting Program, describes information provided by the participating organizations on their aggregate emissions and emissions reductions, as well as their emissions reduction or avoidance projects, through 1995. This information has been compiled into a database that includes reports from 142 organizations and descriptions of 967 projects that either reduced greenhouse gas emissions or sequestered carbon. Fifty-one reporters also provided estimates of emissions, and emissions reductions achieved, for their entire organizations. The projects described actions taken to reduce emissions of carbon dioxide from energy production and use; to reduce methane and nitrous oxide emissions from energy use, waste management, and agricultural processes; to reduce emissions of halocarbons, such as CFCs and their replacements; and to increase carbon sequestration.

Greenhouse gas emissions related to agriculture and land-use practices

International Nuclear Information System (INIS)

Burke, L.M.; Lashof, D.A.

1990-01-01

This paper reports on the effects of increasing trace gas concentrations and concomitant climate change on agriculture which are likely to be substantial. With cropland and pasture now covering 2 , CH 4 , and N 2 O. Land clearing for agriculture and other purposes is responsible for 10 to 30% of total net CO 2 emissions; the rest is due to fossil fuel combustion. In addition, intentional burning of agricultural wastes, grasslands, and forests makes a significant contribution to global emissions of CO, CH 4 , NO x and N 2 O. Methane emissions from anaerobic respiration in rice (Oryza sativa L.) paddies and domestic animal remains account for 30 to 50% of the global total, making agriculture the dominant anthropogenic source of this gas. The amount of N 2 O emitted as a result of N fertilizer applications is highly uncertain, but may be on the order of 10% of total N 2 O emissions. Future agricultural greenhouse gas emissions will be affected by population growth, economic development, and agricultural practices. Greenhouse gas emissions are likely to increase substantially in the future unless steps are taken to control them. Investigating potential approaches to reducing these emissions while expanding production presents a major challenge to the agricultural research community

Emission lines of Mg2 and Ca2 in planetary nebulae

International Nuclear Information System (INIS)

Gurzadyan, G.A.

1979-01-01

Conditions of exciting resonance lines in the emission of ionized magnesium (lambda lambda 2796+2803 Mg2) and calcium (lambda lambda 3934+3968 Ca2) in planetary nebulae have been analyzed. It is shown that the allowed lines are excited with the same mechanism, as the forbidden lines, i.e. inelastic electron collisions, but not with common fluorescence. The emission line lambda 2800 Mg2 of enough force can be observed only in the spectra of planetary nebulae with mean excitation (IC 2149) as well as in the spectra of diffuse nebulae. The line must not be observed in high-excited planetary nebulae (NGC 7026, 7662). The absence of emission lines H and K Ca2 in planetary nebulae spectra results from the fact, that their expected intensity is by 3-4 orders less than the intensity of the line lambda 2800 Mg2 or Hsub(β) hydrogen

The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

International Nuclear Information System (INIS)

Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S.; Bentz, M. C.; Vestergaard, M.; Kilerci-Eser, E.; G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" data-affiliation=" (Dipartimento di Fisica e Astronomia G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" >Dalla Bontà, E.; G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" data-affiliation=" (Dipartimento di Fisica e Astronomia G. Galilei, Università di Padova, Vicolo dell'Osservatorio 3 I-35122, Padova (Italy))" >Ciroi, S.

2013-01-01

The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n e ∼ 10 5 cm –3 ) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

Energy Technology Data Exchange (ETDEWEB)

Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S. [Department of Astronomy, The Ohio State University, 140 W 18th Avenue, Columbus, OH 43210 (United States); Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, 25 Park Place, Suite 610, Atlanta, GA 30303 (United States); Vestergaard, M.; Kilerci-Eser, E. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Dalla Bontà, E.; Ciroi, S. [Dipartimento di Fisica e Astronomia " G. Galilei," Università di Padova, Vicolo dell' Osservatorio 3 I-35122, Padova (Italy)

2013-12-20

The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n {sub e} ∼ 10{sup 5} cm{sup –3}) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

LANDFILL GAS EMISSIONS MODEL (LANDGEM) VERSION 3.02 USER'S GUIDE

Science.gov (United States)

The Landfill Gas Emissions Model (LandGEM) is an automated estimation tool with a Microsoft Excel interface that can be used to estimate emission rates for total landfill gas, methane, carbon dioxide, nonmethane organic compounds, and individual air pollutants from municipal soli...

CO and PAH Emissions from Engines Operating on Biomass Producer Gas

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper; Jensen, Torben Kvist; Henriksen, Ulrik Birk

2003-01-01

High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. The standing regulations concerning CO emissions from producer gas engine based power plants in most EU countrie...

Identification of S VIII through S XIV emission lines between 17.5 and 50 nm in a magnetically confined plasma

Science.gov (United States)

McCarthy, K. J.; Tamura, N.; Combs, S. K.; García, R.; Hernández Sánchez, J.; Navarro, M.; Panadero, N.; Pastor, I.; Soleto, A.; the TJ-II Team

2018-03-01

43 spectral emission lines from F-like to Li-like sulphur ions have been identified in the wavelength range from 17.5 to 50 nm in spectra obtained following tracer injection into plasmas created in a magnetically confined plasma device, the stellarator TJ-II. Plasmas created and maintained in this heliac device with electron cyclotron resonance heating achieve central electron temperatures and densities up to 1.5 keV and 8 × 1018 m-3, respectively. Tracer injections were performed with ≤6 × 1016 atoms of sulphur contained within ˜300 μm diameter polystyrene capsules, termed tracer encapsulated solid pellets, using a gas propulsion system to achieve velocities between 250 and 450 m s-1. Once ablation of the exterior polystyrene shell by plasma particles is completed, the sulphur is deposited in the plasma core where it is ionized up to S+13 and transported about the plasma. In order to aid line identification, which is made using a number of atomic line emission databases, spectra are collected before and after injection using a 1 m focal length normal incidence spectrometer equipped with a CCD camera. This work is motivated by the need to clearly identify sulphur emission lines in the vacuum ultraviolet range of magnetically confined plasmas, as sulphur x-ray emission lines are regularly observed in both tokamak and stellarator plasmas.

Quantifying methane emissions from natural gas production in north-eastern Pennsylvania

Directory of Open Access Journals (Sweden)

Z. R. Barkley

2017-11-01

Full Text Available Natural gas infrastructure releases methane (CH4, a potent greenhouse gas, into the atmosphere. The estimated emission rate associated with the production and transportation of natural gas is uncertain, hindering our understanding of its greenhouse footprint. This study presents a new application of inverse methodology for estimating regional emission rates from natural gas production and gathering facilities in north-eastern Pennsylvania. An inventory of CH4 emissions was compiled for major sources in Pennsylvania. This inventory served as input emission data for the Weather Research and Forecasting model with chemistry enabled (WRF-Chem, and atmospheric CH4 mole fraction fields were generated at 3 km resolution. Simulated atmospheric CH4 enhancements from WRF-Chem were compared to observations obtained from a 3-week flight campaign in May 2015. Modelled enhancements from sources not associated with upstream natural gas processes were assumed constant and known and therefore removed from the optimization procedure, creating a set of observed enhancements from natural gas only. Simulated emission rates from unconventional production were then adjusted to minimize the mismatch between aircraft observations and model-simulated mole fractions for 10 flights. To evaluate the method, an aircraft mass balance calculation was performed for four flights where conditions permitted its use. Using the model optimization approach, the weighted mean emission rate from unconventional natural gas production and gathering facilities in north-eastern Pennsylvania approach is found to be 0.36 % of total gas production, with a 2σ confidence interval between 0.27 and 0.45 % of production. Similarly, the mean emission estimates using the aircraft mass balance approach are calculated to be 0.40 % of regional natural gas production, with a 2σ confidence interval between 0.08 and 0.72 % of production. These emission rates as a percent of production are

Quantifying methane emissions from natural gas production in north-eastern Pennsylvania

Science.gov (United States)

Barkley, Zachary R.; Lauvaux, Thomas; Davis, Kenneth J.; Deng, Aijun; Miles, Natasha L.; Richardson, Scott J.; Cao, Yanni; Sweeney, Colm; Karion, Anna; Smith, MacKenzie; Kort, Eric A.; Schwietzke, Stefan; Murphy, Thomas; Cervone, Guido; Martins, Douglas; Maasakkers, Joannes D.

2017-11-01

Natural gas infrastructure releases methane (CH4), a potent greenhouse gas, into the atmosphere. The estimated emission rate associated with the production and transportation of natural gas is uncertain, hindering our understanding of its greenhouse footprint. This study presents a new application of inverse methodology for estimating regional emission rates from natural gas production and gathering facilities in north-eastern Pennsylvania. An inventory of CH4 emissions was compiled for major sources in Pennsylvania. This inventory served as input emission data for the Weather Research and Forecasting model with chemistry enabled (WRF-Chem), and atmospheric CH4 mole fraction fields were generated at 3 km resolution. Simulated atmospheric CH4 enhancements from WRF-Chem were compared to observations obtained from a 3-week flight campaign in May 2015. Modelled enhancements from sources not associated with upstream natural gas processes were assumed constant and known and therefore removed from the optimization procedure, creating a set of observed enhancements from natural gas only. Simulated emission rates from unconventional production were then adjusted to minimize the mismatch between aircraft observations and model-simulated mole fractions for 10 flights. To evaluate the method, an aircraft mass balance calculation was performed for four flights where conditions permitted its use. Using the model optimization approach, the weighted mean emission rate from unconventional natural gas production and gathering facilities in north-eastern Pennsylvania approach is found to be 0.36 % of total gas production, with a 2σ confidence interval between 0.27 and 0.45 % of production. Similarly, the mean emission estimates using the aircraft mass balance approach are calculated to be 0.40 % of regional natural gas production, with a 2σ confidence interval between 0.08 and 0.72 % of production. These emission rates as a percent of production are lower than rates found in any

HERSCHEL KEY PROGRAM, ''DUST, ICE, AND GAS IN TIME'' (DIGIT): THE ORIGIN OF MOLECULAR AND ATOMIC EMISSION IN LOW-MASS PROTOSTARS IN TAURUS

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeong-Eun; Lee, Seokho [Department of Astronomy and Space Science, Kyung Hee University, Yongin-shi, Kyungki-do 449-701 (Korea, Republic of); Lee, Jinhee [Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602-2451 (United States); Evans II, Neal J.; Green, Joel D., E-mail: jeongeun.lee@khu.ac.kr [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States)

2014-10-01

Six low-mass embedded sources (L1489, L1551-IRS5, TMR1, TMC1-A, L1527, and TMC1) in Taurus have been observed with Herschel-PACS to cover the full spectrum from 50 to 210 μm as part of the Herschel key program, ''Dust, Ice, and Gas In Time''. The relatively low intensity of the interstellar radiation field surrounding Taurus minimizes contamination of the [C II] emission associated with the sources by diffuse emission from the cloud surface, allowing study of the [C II] emission from the source. In several sources, the [C II] emission is distributed along the outflow, as is the [O I] emission. The atomic line luminosities correlate well with each other, as do the molecular lines, but the atomic and molecular lines correlate poorly. The relative contribution of CO to the total gas cooling is constant at ∼30%, while the cooling fraction by H{sub 2}O varies from source to source, suggesting different shock properties resulting in different photodissociation levels of H{sub 2}O. The gas with a power-law temperature distribution with a moderately high density can reproduce the observed CO fluxes, indicative of CO close to LTE. However, H{sub 2}O is mostly subthermally excited. L1551-IRS5 is the most luminous source (Ł{sub bol} = 24.5 L {sub ☉}) and the [O I] 63.1 μm line accounts for more than 70% of its FIR line luminosity, suggesting complete photodissociation of H{sub 2}O by a J shock. In L1551-IRS5, the central velocity shifts of the [O I] line, which exceed the wavelength calibration uncertainty (∼70 km s{sup –1}) of PACS, are consistent with the known redshifted and blueshifted outflow direction.

Extended emission-line regions in active galaxies

International Nuclear Information System (INIS)

Hutchings, J.B.; Hickson, P.

1988-01-01

Long-slit spectra of four active galaxies in the redshift range 0.06-0.10 are presented. Two have interacting companions. Spectra of the galaxies show extended narrow emission lines in all cases. Continuum color changes, emision-line ratio changes, and velocity changes with 1 arcsec resolution can be detected. Relative velocities between AGN and companion galaxies are also given. These objects appear to lie in galaxies in which there is considerable star-formation activity, and very extended line emision. 20 references

Are greenhouse gas emissions from international shipping a type of marine pollution?

International Nuclear Information System (INIS)

Shi, Yubing

2016-01-01

Whether greenhouse gas emissions from international shipping are a type of marine pollution is a controversial issue and is currently open to debate. This article examines the current treaty definitions of marine pollution, and applies them to greenhouse gas emissions from ships. Based on the legal analysis of treaty definitions and relevant international and national regulation on this issue, this article asserts that greenhouse gas emissions from international shipping are a type of ‘conditional’ marine pollution. - Highlights: • Greenhouse gas (GHG) emissions from international shipping are a type of ‘conditional’ marine pollution. • Shipping CO 2 may be treated as marine pollution under the 1972 London Dumping Convention. • Countries have adopted different legislation concerning the legal nature of GHG emissions from ships. • Regulating CO 2 emissions from ships as marine pollution may expedite global GHG emissions reduction.

Greenhouse Gas Emissions from Excavation on Residential Construction Sites

Directory of Open Access Journals (Sweden)

Perry Forsythe

2014-12-01

Full Text Available Despite considerable research concerning the manifestation of greenhouse gases in the usage of buildings, little has been done concerning emissions arising from the construction process itself. This paper specifically examines emissions arising from cut and fill excavation on residential construction sites. Even though such excavation is often seen as being economical in terms of providing a flat base for concrete raft slab construction, the environmental consequences of this approach need to be considered more fully in terms of impact on the environment. This is particularly important when steeply sloping sites are involved and for different soil types. The paper undertakes a study that quantitatively assesses the cumulative greenhouse gas emissions caused by cut and fill excavation on 52 residential projects in Australia for a range of slope and soil types. The paper presents results from the study and concludes that greenhouse gas emissions increase as site slope increases; the building footprint area (as distinct from Gross Floor Area, exposes the need to reduce the area of the building to reduce greenhouse gas emissions; excavation of rock soils creates higher emissions than other soil types; and cut and fill excavation on steeply slope sites increase emissions. Potential alternative construction includes suspended floor construction systems which involve less excavation.

Greenhouse Gas Emissions from Excavation on Residential Construction Sites

Directory of Open Access Journals (Sweden)

Perry Forsythe

2014-12-01

Full Text Available Despite considerable research concerning the manifestation of greenhouse gases in the usage of buildings, little has been done concerning emissions arising from the construction process itself. This paper specifically examines emissions arising from cut and fill excavation on residential construction sites. Even though such excavation is often seen as being economical in terms of providing a flat base for concrete raft slab construction, the environmental consequences of this approach need to be considered more fully in terms of impact on the environment. This is particularly important when steeply sloping sites are involved and for different soil types. The paper undertakes a study that quantitatively assesses the cumulative greenhouse gas emissions caused by cut and fill excavation on 52 residential projects in Australia for a range of slope and soil types. The paper presents results from the study and concludes that greenhouse gas emissions increase as site slope increases; the building footprint area (as distinct from Gross Floor Area, exposes the need to reduce the area of the building to reduce greenhouse gas emissions; excavation of rock soils creates higher emissions than other soil types; and cut and fill excavation on steeply slope sites increase emissions. Potential alternative construction includes suspended floor construction systems which involve less excavation. 

Emission line spectra of Herbig-Haro objects

International Nuclear Information System (INIS)

Brugel, E.W.; Boehm, K.H.; Mannery, E.

1981-01-01

Spectrophotometric data have been obtained for 12 Herbig-Haro nebulae with the multichannel spectrometer on the Mt. Palomar 5.08 m telescope and with the image intensified dissector scanner on the Kitt Peak 2.13 m telescope. Optical emission line fluxes are presented for the following Herbig-Haro objects: H-H 1 (NW), H-H 1 (SE), H-H 2A, H-H 2G, H-H 2H, H-H 3, H-H 7, H-H 11, H-H 24A, H-H 30, H-H 32, and H-H 40. Values for the electron temperature and electron density have been determined for 10 of these condensations. Significant inhomogeneities in the line-forming regions of these H-H objects are indicated by the derived N/sub e/-T/sub e/ diagrams. Empirical two-component density models have been constructed to interpret the emission line spectra of the five brightest condensations. Slightly less satisfactory homogeneous models are presented for the remaining five objects

Power station stack gas emissions

International Nuclear Information System (INIS)

Hunwick, Richard J.

2006-01-01

There are increasing awareness and pressure to reduce emissions of acid rain and photochemical smog. There is a need to produce new control system and equipment to capture those emissions. The most visible form of pollutions are the chimney smoke, dust and particles of fly ash from mineral matter in the fuel. Acid gases are hard on structures and objects containing limestone. Coal fired power generation is likely to be able to sustain its competitive advantage as a clean source of electricity in comparison with nuclear power and natural gas

Greenhouse gas emissions in the Netherlands 1990-1996: Updated methodology

NARCIS (Netherlands)

Spakman J; Olivier JGJ; Loon MMJ van; LAE

1997-01-01

This inventory of greenhouse gas emissions in the Netherlands has been prepared according to the IPCC Guidelines and complies with the obligations under the European Union's Greenhouse Gas Monitoring Mechanism and the UN-FCCC for emission reports on greenhouse gases not covered under the Montreal

Multi objective optimization of line pack management of gas pipeline system

International Nuclear Information System (INIS)

Chebouba, A

2015-01-01

This paper addresses the Line Pack Management of the ''GZ1 Hassi R'mell-Arzew'' gas pipeline. For a gas pipeline system, the decision-making on the gas line pack management scenarios usually involves a delicate balance between minimization of the fuel consumption in the compression stations and maximizing gas line pack. In order to select an acceptable Line Pack Management of Gas Pipeline scenario from these two angles for ''GZ1 Hassi R'mell- Arzew'' gas pipeline, the idea of multi-objective decision-making has been introduced. The first step in developing this approach is the derivation of a numerical method to analyze the flow through the pipeline under transient isothermal conditions. In this paper, the solver NSGA-II of the modeFRONTIER, coupled with a matlab program was used for solving the multi-objective problem

The emission-line regions in the nucleus of NGC 1313 probed with GMOS-IFU: a supergiant/hypergiant candidate and a kinematically cold nucleus

Science.gov (United States)

Menezes, R. B.; Steiner, J. E.

2017-04-01

NGC 1313 is a bulgeless nearby galaxy, classified as SB(s)d. Its proximity allows high spatial resolution observations. We performed the first detailed analysis of the emission-line properties in the nuclear region of NGC 1313, using an optical data cube obtained with the Gemini Multi-object Spectrograph. We detected four main emitting areas, three of them (regions 1, 2 and 3) having spectra typical of H II regions. Region 1 is located very close to the stellar nucleus and shows broad spectral features characteristic of Wolf-Rayet stars. Our analysis revealed the presence of one or two WC4-5 stars in this region, which is compatible with results obtained by previous studies. Region 4 shows spectral features (as a strong Hα emission line, with a broad component) typical of a massive emission-line star, such as a luminous blue variable, a B[e] supergiant or a B hypergiant. The radial velocity map of the ionized gas shows a pattern consistent with rotation. A significant drop in the values of the gas velocity dispersion was detected very close to region 1, which suggests that the young stars there were formed from this cold gas, possibly keeping low values of velocity dispersion. Therefore, although detailed measurements of the stellar kinematics were not possible (due to the weak stellar absorption spectrum of this galaxy), we predict that NGC 1313 may also show a drop in the values of the stellar velocity dispersion in its nuclear region.

Methane emissions due to oil and natural gas operations in the Netherlands

International Nuclear Information System (INIS)

Oonk, J.; Vosbeek, M.E.J.P.

1995-01-01

The Netherlands is the 4th largest natural gas producer, with about 4% of the total world natural gas production. Also, significant amounts of oil are extracted. For this reason it can be expected that methane emissions from oil and natural gas operations contribute significantly to total methane emissions. Estimates so far, made by both the Dutch government and the industry vary widely. A renewed estimate is made of methane emissions from oil and natural gas production, based on a detailed engineering study of sources of methane in the system and quantification of source strengths. The estimate is validated by interpretation of atmospheric measurements. 1990 methane emissions from natural gas production were estimated to be 62 to 108 kton. The main cause of methane emissions is the venting of off-gases from processes and passing-valve emissions in the off-shore. Emissions from oil production were estimated to be 14 kton, mainly caused by venting of off-gases from processes. Best feasible options for emission reduction are: identification and replacement of leaking valves, and reuse or re-compression of off-gases from processes. Both options are existing policy in the Netherlands. 23 figs., 38 tabs., 2 appendices, 53 refs

6.1 Greenhouse gas emissions and climate change

International Nuclear Information System (INIS)

2004-01-01

In Austria, greenhouse gas emissions (GHG) have increased by about 10 % between 1990 and 2001. This means that already in 2001 the emissions reached the level projected with current measures for 2010. Thus Austria is far from complying with the 13 % reduction required under the Kyoto Protocol, meaning that GHG emissions will have to be reduce annually by 1.4 million tons of CO 2 -equivalents to fulfill its protocol obligation. It is shown that 2001 GHG emissions had increased by 9.6 % since the base year 1990, the main reason for this increase is the growing use of fossil fuels and the resulting increase in CO 2 emissions. The highest growth rates can be observed in the transport sector by almost half (+ 49 %). Basically, greenhouse gas emission trends depend on a number of factors, about two thirds of them are caused by energy production, so the most important parameters affecting GHG are the trends of energy consumption, the energy mix and the following factors: population growth, economic growth, outdoor temperature and the resulting heating requirements, improvement of energy efficiency, the proportion of renewable energy sources such as electricity generation in hydroelectric power stations (which influences the need for supplementary power production in thermal power plants), the mix of fossil fuels, for example in caloric power plants (natural gas combustion produces about 40 % less CO 2 per energy unit than coal combustion), the structure and price effects of energy market liberalization, which influence the use of various fuels in electricity production and the import of electricity, world market prices for energy, structural changes in the economy and in the behavior of consumers. Changes in important driving forces and in GHG emissions, sector emissions trends and Austrian, European and global emissions projections are provided. (nevyjel)

Greenhouse Gas Emissions Calculator for Grain and Biofuel Farming Systems

Science.gov (United States)

McSwiney, Claire P.; Bohm, Sven; Grace, Peter R.; Robertson, G. Philip

2010-01-01

Opportunities for farmers to participate in greenhouse gas (GHG) credit markets require that growers, students, extension educators, offset aggregators, and other stakeholders understand the impact of agricultural practices on GHG emissions. The Farming Systems Greenhouse Gas Emissions Calculator, a web-based tool linked to the SOCRATES soil…

Observations of far-infrared line profiles in the Orion-KL region

International Nuclear Information System (INIS)

Crawford, M.K.; Lugten, J.B.; Fitelson, W.; Genzel, R.; Melnick, G.; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA)

1986-01-01

Measurements of several far-infrared emission line profiles in the Orion-KL region are reported. The emission from the CO, OH, and forbidden O I emission lines toward the BN-KL and H2 peak 1 positions probably comes from dense, hot molecular gas in the Orion-KL shock. The CO and forbidden O I lines have similar profiles, suggesting that the high-velocity forbidden O I emission also arises in magnetohydrodynamic cloud shocks. The velocity centroids of the lines are somewhat blueshifted. The far-infrared data thus support the interpretation that the blue asymmetry of the H2 2 micron lines is not mainly due to differential dust extinction, but rather to the kinematics and geometry of the shocked gas in the Orion-KL outflow. The forbidden O I and CO lines, however, have significantly less extreme blueshifted emission than the H2 lines. Both the forbidden O I 63 micron and forbidden C II 158 micron lines have features strongly supporting a common origin near the surface of the Orion molecular cloud. 28 references

Portuguese agriculture and the evolution of greenhouse gas emissions-can vegetables control livestock emissions?

Science.gov (United States)

Mourao, Paulo Reis; Domingues Martinho, Vítor

2017-07-01

One of the most serious externalities of agricultural activity relates to greenhouse gas emissions. This work tests this relationship for the Portuguese case by examining data compiled since 1961. Employing cointegration techniques and vector error correction models (VECMs), we conclude that the evolution of the most representative vegetables and fruits in Portuguese production are associated with higher controls on the evolution of greenhouse gas emissions. Reversely, the evolution of the output levels of livestock and the most representative animal production have significantly increased the level of CO 2 (carbon dioxide) reported in Portugal. We also analyze the cycle length of the long-term relationship between agricultural activity and greenhouse gas emissions. In particular, we highlight the case of synthetic fertilizers, whose values of CO 2 have quickly risen due to changes in Portuguese vegetables, fruit, and animal production levels.

New upper limit to the coronal line emission from the T Tauri star RU Lupi

Energy Technology Data Exchange (ETDEWEB)

Gahm, G F [Stockholm Observatory (Sweden); Lago, M T.V.T. [Universidade do Porto (Portugal). Grupo de Matematica Aplicada; Penston, M V [ESTEC, European Space Agency, Villafranca Satellite Tracking Station, Madrid, (Spain)

1981-05-01

A high dispersion AAT spectrogram sets an upper limit on the (Fe x) emission line lambda 6374.5 A in the T Tauri star RU Lupi. The intensity of any 10/sup 6/ K corona in this star is less than 600 times that of the Sun compared to a chromosphere and transition region of 3 x 10/sup 3/ to 2 x 10/sup 5/ K gas 10/sup 6/ times stronger than the Sun's. The important theoretical implications are noted.

Modeling greenhouse gas emissions from dairy farms.

Science.gov (United States)

Rotz, C Alan

2017-11-15

Dairy farms have been identified as an important source of greenhouse gas emissions. Within the farm, important emissions include enteric CH 4 from the animals, CH 4 and N 2 O from manure in housing facilities during long-term storage and during field application, and N 2 O from nitrification and denitrification processes in the soil used to produce feed crops and pasture. Models using a wide range in level of detail have been developed to represent or predict these emissions. They include constant emission factors, variable process-related emission factors, empirical or statistical models, mechanistic process simulations, and life cycle assessment. To fully represent farm emissions, models representing the various emission sources must be integrated to capture the combined effects and interactions of all important components. Farm models have been developed using relationships across the full scale of detail, from constant emission factors to detailed mechanistic simulations. Simpler models, based upon emission factors and empirical relationships, tend to provide better tools for decision support, whereas more complex farm simulations provide better tools for research and education. To look beyond the farm boundaries, life cycle assessment provides an environmental accounting tool for quantifying and evaluating emissions over the full cycle, from producing the resources used on the farm through processing, distribution, consumption, and waste handling of the milk and dairy products produced. Models are useful for improving our understanding of farm processes and their interacting effects on greenhouse gas emissions. Through better understanding, they assist in the development and evaluation of mitigation strategies for reducing emissions and improving overall sustainability of dairy farms. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article

Observation of soft X-ray spectra from a Seyfert 1 and a narrow emission-line galaxy

International Nuclear Information System (INIS)

Singh, K.P.; Garmire, G.P.; Nousek, J.

1985-01-01

The 0.2-40 keV X-ray spectra of the Seyfert 1 galaxy Mrk 509 and the narrow emission-line galaxy NGC 2992 are analyzed. The results suggest the presence of a steep soft X-ray component in Mrk 509 in addition to the well-known Gamma = 1.7 component found in other active galactic nuclei in the 2-40 keV energy range. The soft X-ray component is interpreted as due to thermal emission from a hot gas, probably associated with the highly ionized gas observed to be outflowing from the galaxy. The X-ray spectrum of NGC 2992 does not show any steepening in the soft X-ray band and is consistent with a single power law (Gamma = 1.78) with very low absorbing column density of 4 x 10 to the 21st/sq cm. A model with partial covering of the nuclear X-ray source is preferred, however, to a simple model with a single power law and absorption. 34 references

H2 emission from Herbig-Haro objects

International Nuclear Information System (INIS)

Elias, J.H.

1980-01-01

Molecular hydrogen emission lines have been detected in six Herbig-Haro objects. The line intensities suggest tha the H 2 emission arises in a moderate-density, shock-heated gas, consistent with evidence for a similar origin of the visible emission-line spectra in Herbig-Haro objects. Indirect arguments indicate that the typical H 2 line widths are less than 70 km s -1 and that typical helicentric radial velocities are no more than 30 km s -1 in magnitude

Constraining Line-of-sight Confusion in the Corona Using Linearly Polarized Observations of the Infrared FeXIII 1075nm and SiX 1430nm Emission Lines

Science.gov (United States)

Dima, G. I.; Kuhn, J. R.; Berdyugina, S.

2017-12-01

Measurements of the coronal magnetic field are difficult because of the intrinsically faint emission of coronal plasma and the large spurious background due to the bright solar disk. This work addresses the problem of resolving the confusion of the line-of-sight (LOS) integration through the optically-thin corona being observed. Work on developing new measuring techniques based on single-point inversions using the Hanle effect has already been described (Dima et al. 2016). It is important to develop a technique to assess when the LOS confusion makes comparing models and observations problematic. Using forward integration of synthetic emission through magnetohydrodynamic (MHD) models together with simultaneous linearly polarized observations of the FeXIII 1075nm and SiX 1430nm emission lines allows us to assess LOS confusion. Since the lines are both in the Hanle saturated regime their polarization angles are expected to be aligned as long as the gas is sampling the same magnetic field. If significant contributions to the emission is taking place from different regions along the LOS due to the additive nature of the polarized brightness the measured linear polarization between the two lines will be offset. The size of the resolution element is important for this determination since observing larger coronal regions will confuse the variation along the LOS with that in the plane-of-sky. We also present comparisons between synthetic linearly polarized emission through a global MHD model and observations of the same regions obtained using the 0.5m Scatter-free Observatory for Limb Active Regions and Coronae (SOLARC) telescope located on Haleakala, Maui. This work is being done in preparation for the type of observations that will become possible when the next generation 4m DKIST telescope comes online in 2020.

Reducing Greenhouse Gas Emissions from Agricultural Wetlands in Borneo

Science.gov (United States)

Abdul, H.; Fatah, L.; Nursyamsi, D.; Kazuyuki, I.

2011-12-01

At the forum G20 meeting in 2009, Indonesian President delivered Indonesia's commitment to reduce national greenhouse gas (GHG) emissions by 26% in 2020 by unilateral action and by 41% with support of other countries. To achieve the target, Indonesian government has put forestry, agriculture (including peatlands), energy, industry and transportation as main responsible sectors. Development of crop with low GHG emissions, increasing C sequestration and the use of organic fertilizers are among the activities to be carried out in 2010-2020 period to minimize GHG emissions from agricultural sectors. Three experiments have been carried out to elucidate the reflectivity of crop selection, soil ameliorants and organic fertilizers on GHG emissions from agricultural wetlands in Borneo. Firstly, gas samples were collected in weekly basis from oil palm, paddy, and vegetables fields and analyzed for methane (CH4) and nitrous oxide (N2O) concentrations by a gas chromatography. Secondly, coal fly ash, dolomite and ZnSO4 were incorporated into a pot containing peat and/or alluvial soils taken from wetlands in South Kalimantan. The air samples were taken and analyzed for CH4 by a gas chromatography. Finally, microbial consortium are isolated from soil, sediment and cow dung. The microbes were then propagated and used in a rice straw composting processes. The CO2, CH4 and N2O emissions from composting vessel were measured at one, two and four weeks of composting processes. The results showed that shifting the use of peatlands for oil palm to vegetable field reduced the GHG emissions by about 74% and that to paddy field reduce the GHG emissions by about 82%. The CH4 emissions from paddy field can be further reduced by applying dolomite. However, the use of coal fly ash and ZnSO4 increased CH4 emissions from peat soil cultivated to rice. The use of microbe isolated from saline soil could reduce GHG emissions during the composting of rice straw. The social aspect of GHG reduction in

Greenhouse gas emission reduction options and strategies

International Nuclear Information System (INIS)

Kane, R.L.

1994-01-01

This paper describes the energy-related components of the Clinton Administration's Climate Change Action Plan. The Action Plan was formulated to meet the Administration's commitment of returning US emissions of greenhouse gases to 1990 levels by the year 2000. The paper discusses what the energy industry and energy consumers will be requested to do in order to meet this commitment. Several themes addressed in this paper include: (1) the largely voluntary nature of the actions identified in the Action Plan; (2) consideration of diverse opportunities to reduce emissions; (3) the outlook for US greenhouse gas emissions after 2000; and (4) actions involved for speeding the utilization of new, energy efficient technologies both domestically and abroad. The value of employing a diverse set of activities and the important role of technology improvements will be explored further in section 10 of this volume: ''Greenhouse Gas Emission Mitigation Strategies.'' Papers presented there include the utilization of more efficient fossil energy technologies, energy conservation and demand-side management programs, renewable energy and reforestation, and carbon dioxide capture and disposal

Gas Emission Prediction Model of Coal Mine Based on CSBP Algorithm

Directory of Open Access Journals (Sweden)

Xiong Yan

2016-01-01

Full Text Available In view of the nonlinear characteristics of gas emission in a coal working face, a prediction method is proposed based on cuckoo search algorithm optimized BP neural network (CSBP. In the CSBP algorithm, the cuckoo search is adopted to optimize weight and threshold parameters of BP network, and obtains the global optimal solutions. Furthermore, the twelve main affecting factors of the gas emission in the coal working face are taken as input vectors of CSBP algorithm, the gas emission is acted as output vector, and then the prediction model of BP neural network with optimal parameters is established. The results show that the CSBP algorithm has batter generalization ability and higher prediction accuracy, and can be utilized effectively in the prediction of coal mine gas emission.

Methane emissions from natural gas pipelines - current estimates, technologies and practices

International Nuclear Information System (INIS)

Lang, M.C.; Crook, L.

1997-01-01

Methane is the major component of natural gas. World-wide methane emissions from gas systems is estimated to be between 50 and 25 tera grams or about 5 percent of the world-wide total of anthropogenic methane emissions. Technologies and practices are described that are currently being used or are planned to be used in the US to both measure and/or reduce methane emissions from natural gas pipelines. One of the technologies that is described includes a high flow sampling instrument. One of the practices that is described is the current voluntary program conducted by the US Environmental Protection Agency called the Natural Gas Star program. This program supports research into best management practices, information sharing and technology transfer to promote methane emissions reductions profitably. (R.P.)

Estimate of methane emissions from the U.S. natural gas industry

International Nuclear Information System (INIS)

Kirchgessner, D.A.; Lott, R.A.; Cowgill, R.M.; Harrison, M.R.; Shires, T.M.

1997-01-01

Global methane emissions from the fossil fuel industries have been poorly quantified and, in many cases, emissions are not well-known even at the country level. Historically, methane emissions from the U.S. gas industry have been based on sparse data, incorrect assumptions, or both. As a result, the estimate of the contribution these emissions make to the global methane inventory could be inaccurate. For this reason the assertion that global warming could be reduced by replacing coal and oil fuels with natural gas could not be defended. A recently completed, multi year study conducted by the U.S. Environmental Protection Agency's Office of Research and Development and the Gas Research Institute, had the objective of determining methane emissions from the U.S. gas industry with an accuracy of ± 0.5% of production. The study concluded that, in the 1992 base year, methane emissions from the industry were 314 ± 105 Bscf or 6.04 ± 2.01 Tg (all conversions to international units are made at 15.56 o C and 101.325 kPa). (author)

The Natural Gas Vehicle Challenge 1992: Exhaust emissions testing and results

Science.gov (United States)

Rimkus, W. A.; Larsen, R. P.; Zammit, M. G.; Davies, J. G.; Salmon, G. S.; Bruetsch, R. I.

The Natural Gas Vehicle (NGV) Challenge '92, was organized by Argonne National Laboratory. The main sponsors were the U.S. Department of Energy the Energy, Mines, and Resources -- Canada, and the Society of Automotive Engineers. It resulted in 20 varied approaches to the conversion of a gasoline-fueled, spark-ignited, internal combustion engine to dedicated natural gas use. Starting with a GMC Sierra 2500 pickup truck donated by General Motors, teams of college and university student engineers worked to optimize Chevrolet V-8 engines operating on natural gas for improved emissions, fuel economy, performance, and advanced design features. This paper focuses on the results of the emission event, and compares engine mechanical configurations, engine management systems, catalyst configurations and locations, and approaches to fuel control and the relationship of these parameters to engine-out and tailpipe emissions of regulated exhaust constituents. Nine of the student modified trucks passed the current levels of exhaust emission standards, and some exceeded the strictest future emissions standards envisioned by the U.S. Environmental Protection Agency. Factors contributing to good emissions control using natural gas are summarized, and observations concerning necessary components of a successful emissions control strategy are presented.

Direct greenhouse gas emissions of the game industry in South Africa

African Journals Online (AJOL)

Direct greenhouse gas emissions of the game industry in South Africa. ... Previous greenhouse gas (GHG) inventories did not include game as an emissions source. Recently game farming has ... AJOL African Journals Online. HOW TO USE ...

Reducing greenhouse gas emissions from u.s. transportation

Science.gov (United States)

2010-01-01

This report examines the prospects for substantially reducing the greenhouse gas (GHG) emissions from the U.S. transportation sector, which accounts for 27 percent of the GHG emissions of the entire U.S. economy and 30 percent of the world's transpor...

Reducing greenhouse gas emissions through operations and supply chain management

International Nuclear Information System (INIS)

Plambeck, Erica L.

2012-01-01

The experiences of the largest corporation in the world and those of a start-up company show how companies can profitably reduce greenhouse gas emissions in their supply chains. The operations management literature suggests additional opportunities to profitably reduce emissions in existing supply chains, and provides guidance for expanding the capacity of new “zero emission” supply chains. The potential for companies to profitably reduce emissions is substantial but (without effective climate policy) likely insufficient to avert dangerous climate change. - Highlights: ► Describes how firms are profitably reducing greenhouse gas emissions in their supply chains ► Highlights academic literature relevant to supply chain emission reduction

An experimental investigation on the properties of laser-induced plasma emission spectra

International Nuclear Information System (INIS)

Tang Xiaoshuan; Li Chunyan; Ji Xuehan; Feng Eryin; Cui Zhifeng

2004-01-01

The authors have measured the time-resolved emission spectra produced by Nd: YAG laser induced Al plasma with different kinds of buffer gas (He, Ar, N 2 and Air). The dependence of emission spectra line intensity and Stark broadening on the time delay, kinds and pressure of buffer gas are studied. The results show that the atomic emission line intensity reaches maximum at 3 μs time delay, the Stark broadening increases with increasing the pressure of buffer gas, and decreases with increasing time delay. The Stark broadening in Ar buffer gas is largest among the four different kinds of buffer gas. (author)

Organic lining materials test in flue gas ducts

International Nuclear Information System (INIS)

Raveh, R.; Sfez, D.; Johannsson, L.

1998-01-01

Corrosion protection solutions are being widely used in electric power plants equipped with Flue Gas Desulfurization (FGD) systems. Organic lining materials are one of many solutions available on the market for corrosion protection. This market segment is found in a continuous development in order to fulfill the severe demands of these materials. The main goal of this test is to obtain information about the high temperature resistance of the materials as occurs when the FGD system is by-passed. Aster initial investigation of this market segment only a few lining materials were found compatible according to their manufacturer data. Seven of these materials were installed in the outlet flue gas duct of the Israeli power station M.D. B. This power station is not equipped with a FGD system, thus it gives a real simulation of the environmental conditions into which the lining material is subjected when the FGD system is by-passed. The materials installation was observed carefully and performed by representatives from the manufacturers in order to avoid material failure due to a non-adequate application. The power station was shut down and the lining materials were inspected three and a half months after the lining materials were applied. The inspection results were good and besides changes in the lining color, most materials did not show any damages. During that time the flue gas temperature at the duct was 134?C except some temperature fluctuations

Accounting For Greenhouse Gas Emissions From Flooded Lands

Science.gov (United States)

Nearly three decades of research has demonstrated that the inundation of rivers and terrestrial ecosystems behind dams can lead to enhanced rates of greenhouse gas emissions, particularly methane. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories includes a method...

X-RAY AND MULTIWAVELENGTH INSIGHTS INTO THE NATURE OF WEAK EMISSION-LINE QUASARS AT LOW REDSHIFT

Energy Technology Data Exchange (ETDEWEB)

Wu Jianfeng; Brandt, W. N.; Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Diamond-Stanic, Aleksandar M. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92903 (United States); Hall, Patrick B. [Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, ON M3J 1P3 (Canada); Plotkin, Richard M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Shemmer, Ohad, E-mail: jfwu@astro.psu.edu [Department of Physics, University of North Texas, Denton, TX 76203 (United States)

2012-03-01

We report on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey (SDSS) with redshift z = 0.4-2.5. Our sample was selected from the Plotkin et al. catalog of radio-quiet, weak-featured active galactic nuclei (AGNs). The distribution of relative X-ray brightness for our low-redshift weak-line quasar (WLQ) candidates is significantly different from that of typical radio-quiet quasars, having an excess of X-ray weak sources, but it is consistent with that of high-redshift WLQs. Over half of the low-redshift WLQ candidates are X-ray weak by a factor of {approx}> 5, compared to a typical SDSS quasar with similar UV/optical luminosity. These X-ray weak sources generally show similar UV emission-line properties to those of the X-ray weak quasar PHL 1811 (weak and blueshifted high-ionization lines, weak semiforbidden lines, and strong UV Fe emission); they may belong to the notable class of PHL 1811 analogs. The average X-ray spectrum of these sources is somewhat harder than that of typical radio-quiet quasars. Several other low-redshift WLQ candidates have normal ratios of X-ray-to-optical/UV flux, and their average X-ray spectral properties are also similar to those of typical radio-quiet quasars. The X-ray weak and X-ray normal WLQ candidates may belong to the same subset of quasars having high-ionization 'shielding gas' covering most of the wind-dominated broad emission-line region, but be viewed at different inclinations. The mid-infrared-to-X-ray spectral energy distributions (SEDs) of these sources are generally consistent with those of typical SDSS quasars, showing that they are not likely to be BL Lac objects with relativistically boosted continua and diluted emission lines. The mid-infrared-to-UV SEDs of most radio-quiet weak-featured AGNs without sensitive X-ray coverage (34 objects) are also consistent with those of typical SDSS quasars. However, one source in our

X-RAY AND MULTIWAVELENGTH INSIGHTS INTO THE NATURE OF WEAK EMISSION-LINE QUASARS AT LOW REDSHIFT

International Nuclear Information System (INIS)

Wu Jianfeng; Brandt, W. N.; Schneider, Donald P.; Anderson, Scott F.; Diamond-Stanic, Aleksandar M.; Hall, Patrick B.; Plotkin, Richard M.; Shemmer, Ohad

2012-01-01

We report on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey (SDSS) with redshift z = 0.4-2.5. Our sample was selected from the Plotkin et al. catalog of radio-quiet, weak-featured active galactic nuclei (AGNs). The distribution of relative X-ray brightness for our low-redshift weak-line quasar (WLQ) candidates is significantly different from that of typical radio-quiet quasars, having an excess of X-ray weak sources, but it is consistent with that of high-redshift WLQs. Over half of the low-redshift WLQ candidates are X-ray weak by a factor of ∼> 5, compared to a typical SDSS quasar with similar UV/optical luminosity. These X-ray weak sources generally show similar UV emission-line properties to those of the X-ray weak quasar PHL 1811 (weak and blueshifted high-ionization lines, weak semiforbidden lines, and strong UV Fe emission); they may belong to the notable class of PHL 1811 analogs. The average X-ray spectrum of these sources is somewhat harder than that of typical radio-quiet quasars. Several other low-redshift WLQ candidates have normal ratios of X-ray-to-optical/UV flux, and their average X-ray spectral properties are also similar to those of typical radio-quiet quasars. The X-ray weak and X-ray normal WLQ candidates may belong to the same subset of quasars having high-ionization 'shielding gas' covering most of the wind-dominated broad emission-line region, but be viewed at different inclinations. The mid-infrared-to-X-ray spectral energy distributions (SEDs) of these sources are generally consistent with those of typical SDSS quasars, showing that they are not likely to be BL Lac objects with relativistically boosted continua and diluted emission lines. The mid-infrared-to-UV SEDs of most radio-quiet weak-featured AGNs without sensitive X-ray coverage (34 objects) are also consistent with those of typical SDSS quasars. However, one source in our X

Greenhouse Gas Emissions in the Netherlands 1990-2010. National Inventory Report 2012

Energy Technology Data Exchange (ETDEWEB)

Coenen, P.W.H.G.; Van der Hoek, K.W.; Te Molder, R.; Droege, R. [Netherlands Organisation for Applied Scientific Research TNO, P.O. Box 80015, NL-3508 TA Utrecht (Netherlands); Van der Maas, C.W.M.; Zijlema, P.J.; Van den Berghe, A.C.W.M. [NL Agency, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Baas, K. [Statistics Netherlands CBS, P.O. Box 24500, NL-2490 HA Den Haag (Netherlands); Te Biesebeek, J.D.; Brandt, A.T. [Dutch Emission Authority, P.O. Box 91503, IPC 652, NL-2509 EC Den Haag (Netherlands); Geilenkirchen, G. [Netherlands Environmental Assessment Agency PBL, P.O. Box 303 NL-3720 AH Bilthoven (Netherlands); Montfoort, J.A.; Peek, C.J.; Vonk, J.; Van den Wyngaert, I. [Alterra Wageningen UR, P.O. Box 47 NL-6700 AA Wageningen (Netherlands)

2012-03-15

The total greenhouse gas emission from the Netherlands in 2010 increased by approximately 6% compared to the emission in 2009. This increase is mainly the result of increased fuel combustion in the energy sector and space heating. In 2010, total direct greenhouse gas emissions (excluding emissions from LULUCF - land use, land use change and forestry) in the Netherlands amounted to 210.1 Tg CO2 eq. This is approximately 1.5% below the emissions in the base year (213.3 Tg CO2 eq). This report documents the 2012 Netherlands' annual submission of its greenhouse gas emission inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.

Greenhouse Gas Emissions in the Netherlands 1990-2009. National Inventory Report 2011

Energy Technology Data Exchange (ETDEWEB)

Coenen, P.W.H.G.; Van der Hoek, K.W.; Te Molder, R.; Droege, R. [Netherlands Organisation for Applied Scientific Research TNO, P.O. Box 80015, NL-3508 TA Utrecht (Netherlands); Van der Maas, C.W.M.; Zijlema, P.J.; Van den Berghe, A.C.W.M. [NL Agency, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Baas, K. [Statistics Netherlands CBS, P.O. Box 24500, NL-2490 HA Den Haag (Netherlands); Te Biesebeek, J.D.; Brandt, A.T. [Dutch Emission Authority, P.O. Box 91503, IPC 652, NL-2509 EC Den Haag (Netherlands); Geilenkirchen, G. [Netherlands Environmental Assessment Agency PBL, P.O. Box 303 NL-3720 AH Bilthoven (Netherlands); Montfoort, J.A.; Peek, C.J.; Vonk, J.; Van den Wyngaert, I. [Alterra Wageningen UR, P.O. Box 47 NL-6700 AA Wageningen (Netherlands)

2012-03-15

The total greenhouse gas emission from the Netherlands in 2010 increased by approximately 6% compared to the emission in 2009. This increase is mainly the result of increased fuel combustion in the energy sector and space heating. In 2010, total direct greenhouse gas emissions (excluding emissions from LULUCF - land use, land use change and forestry) in the Netherlands amounted to 210.1 Tg CO2 eq. This is approximately 1.5% below the emissions in the base year (213.3 Tg CO2 eq). This report documents the 2012 Netherlands' annual submission of its greenhouse gas emission inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.

Greenhouse Gas Emissions in the Netherlands 1990-2009. National Inventory Report 2011

International Nuclear Information System (INIS)

Van der Maas, C.W.M.; Coenen, P.W.H.G.; Van der Hoek, K.W.; Te Molder, R.; Droege, R.; Zijlema, P.J.; Van den Berghe, G.; Baas, K.; Te Biesebeek, J.D.; Brandt, A.T.; Geilenkirchen, G.; Peek, C.J.; Vonk, J.; Van den Wyngaert, I.

2011-04-01

The total greenhouse gas emission from the Netherlands in 2009 decreased by approximately 3% compared to the emission in 2008. This decrease is a result of the economic crisis, especially due to the decrease in the industrial production. In 2009, total direct greenhouse gas emissions (excluding emissions from LULUCF - land use, land use change and forestry) in the Netherlands amount to 198.9Tg CO2 eq. This is nearly 7 % below the emissions in the base year 1990 (213.2 Tg CO2 eq). This report documents the 2011 Netherlands' annual submission of its greenhouse gas emission inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.

Greenhouse Gas Emissions in the Netherlands 1990-2009. National Inventory Report 2011

Energy Technology Data Exchange (ETDEWEB)

Coenen, P W.H.G.; Van der Hoek, K W; Te Molder, R; Droege, R [Netherlands Organisation for Applied Scientific Research TNO, P.O. Box 80015, NL-3508 TA Utrecht (Netherlands); Van der Maas, C W.M.; Zijlema, P J; Van den Berghe, A C.W.M. [NL Agency, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Baas, K [Statistics Netherlands CBS, P.O. Box 24500, NL-2490 HA Den Haag (Netherlands); Te Biesebeek, J D; Brandt, A T [Dutch Emission Authority, P.O. Box 91503, IPC 652, NL-2509 EC Den Haag (Netherlands); Geilenkirchen, G [Netherlands Environmental Assessment Agency PBL, P.O. Box 303 NL-3720 AH Bilthoven (Netherlands); Montfoort, J A; Peek, C J; Vonk, J; Van den Wyngaert, I [Alterra Wageningen UR, P.O. Box 47 NL-6700 AA Wageningen (Netherlands)

2012-03-15

The total greenhouse gas emission from the Netherlands in 2010 increased by approximately 6% compared to the emission in 2009. This increase is mainly the result of increased fuel combustion in the energy sector and space heating. In 2010, total direct greenhouse gas emissions (excluding emissions from LULUCF - land use, land use change and forestry) in the Netherlands amounted to 210.1 Tg CO2 eq. This is approximately 1.5% below the emissions in the base year (213.3 Tg CO2 eq). This report documents the 2012 Netherlands' annual submission of its greenhouse gas emission inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.

Greenhouse Gas Emissions in the Netherlands 1990-2010. National Inventory Report 2012

Energy Technology Data Exchange (ETDEWEB)

Coenen, P. W.H.G.; Van der Hoek, K. W.; Te Molder, R.; Droege, R. [Netherlands Organisation for Applied Scientific Research TNO, P.O. Box 80015, NL-3508 TA Utrecht (Netherlands); Van der Maas, C. W.M.; Zijlema, P. J.; Van den Berghe, A. C.W.M. [NL Agency, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Baas, K. [Statistics Netherlands CBS, P.O. Box 24500, NL-2490 HA Den Haag (Netherlands); Te Biesebeek, J. D.; Brandt, A. T. [Dutch Emission Authority, P.O. Box 91503, IPC 652, NL-2509 EC Den Haag (Netherlands); Geilenkirchen, G. [Netherlands Environmental Assessment Agency PBL, P.O. Box 303 NL-3720 AH Bilthoven (Netherlands); Montfoort, J. A.; Peek, C. J.; Vonk, J.; Van den Wyngaert, I. [Alterra Wageningen UR, P.O. Box 47 NL-6700 AA Wageningen (Netherlands)

2012-03-15

The total greenhouse gas emission from the Netherlands in 2010 increased by approximately 6% compared to the emission in 2009. This increase is mainly the result of increased fuel combustion in the energy sector and space heating. In 2010, total direct greenhouse gas emissions (excluding emissions from LULUCF - land use, land use change and forestry) in the Netherlands amounted to 210.1 Tg CO2 eq. This is approximately 1.5% below the emissions in the base year (213.3 Tg CO2 eq). This report documents the 2012 Netherlands' annual submission of its greenhouse gas emission inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.

Evaluation of greenhouse gas emissions from waste management approaches in the islands.

Science.gov (United States)

Chen, Ying-Chu

2017-07-01

Concerns about waste generation and climate change have attracted worldwide attention. Small islands, which account for more than one-sixth of the global land area, are facing problems caused by global climate change. This study evaluated the greenhouse gas emissions from five small islands surrounding Taiwan. These islands - Penghu County, Liuqui Island, Kinmen County, Matsu Island and Green Island - have their own waste management approaches that can serve as a guideline for waste management with greenhouse gas mitigation. The findings indicate that the total annual greenhouse gas emissions of the islands ranged from 292.1 to 29,096.2 [metric] tonne CO 2 -equivalent. The loading waste volumes and shipping distances were positively related to greenhouse gas emissions from transportation. The greenhouse gas emissions from waste-to-energy plants, mainly carbon dioxide and nitrous oxide, can be offset by energy recovery (approximately 38.6% of greenhouse gas emissions from incineration). In addition, about 34% and 11% of waste generated on the islands was successfully recycled and composted, respectively. This study provides valuable insights into the applicability of a policy framework for waste management approaches for greenhouse gas mitigation.

Greenhouse gas and livestock emissions and climate change

DEFF Research Database (Denmark)

Caro, Dario

2018-01-01

The paper summarizes the current knowledge about the impact of livestock sector on climate change. The main sources of greenhouse gas (GHG) emissions from livestock are described and the contribution of livestock sector to the global GHG emissions is presented on the basis of the latest results...... obtained from the scientific research. The most recent mitigation strategies for reducing greenhouse gas emissions from livestock sector are also discussed. The paper aims to provide a general overview of an emergent environmental issue such as the impact of livestock sector on climate change. While...... the paper is easy to understand for non-expert readers, it may also be a relevant reference point for academic researchers and for policy makers aimed at achieving the sustainability of livestock/food sector....

Unification in the low radio luminosity regime: evidence from optical line emission

Science.gov (United States)

Marchã, M. J. M.; Browne, I. W. A.; Jethava, N.; Antón, S.

2005-08-01

We address the question of whether or not the properties of all low-luminosity flat spectrum radio sources, not just the obvious BL Lac objects, are consistent with them being the relativistically beamed counterparts of the low radio luminosity radio galaxies (the Fanaroff-Riley type 1, FR I). We have accumulated data on a well-defined sample of low redshift, core-dominated, radio sources all of which have one-sided core-jet structures seen with very long baseline interferometry, just like most BL Lac objects. We first compare the emission-line luminosities of the sample of core-dominated radio sources with a matched sample of FR I radio galaxies. The emission lines in the core-dominated objects are on average significantly more luminous than those in the comparison sample, inconsistent with the simplest unified models in which there is no orientation dependence of the line emission. We then compare the properties of our core-dominated sample with those of a sample of radio-emitting UGC galaxies selected without bias to core strength. The core-dominated objects fit well on the UGC correlation between line emission and radio core strength found by Verdoes Kleijn et al. The results are not consistent with all the objects participating in a simple unified model in which the observed line emission is orientation independent, though they could fit a single, unified model provided that some FR I radio galaxies have emission line regions that become more visible when viewed along the jet axis. However, they are equally consistent with a scenario in which, for the majority of objects, beaming has minimal effect on the observed core luminosities of a large fraction of the FR I population and that intrinsically stronger cores simply give rise to stronger emission lines. We conclude that FR I unification is much more complex than usually portrayed, and models combining beaming with an intrinsic relationship between core and emission line strengths need to be explored.

The CO2-tax and its ability to reduce CO2 emissions related to oil and gas production in Norway

International Nuclear Information System (INIS)

Roemo, F.; Lund, M.W.

1994-01-01

The primary ambition of the paper is to illustrate some relevant effects of the CO 2 -tax, and draw the line from company adaptation via national ambitions and goals to global emission consequences. The CO 2 -tax is a success for oil and gas production only to the extent that the CO 2 emission per produced unit oil/gas is reduced as a consequence of the tax. If not, the CO 2 -tax is a pure fiscal tax and has no qualitative impact on the CO 2 emissions. The reduction potential is then isolated to the fact that some marginal fields will not be developed, and the accelerated close down of fields in production. The paper indicates that a significant replacement of older gas turbines at a certain level of the CO 2 -tax could be profitable for the companies. This is dependent on change in turbine energy utilization, and the investment cost. The CO 2 -tax is a political success for the nation if it is a significant contributor to achieve national emission goals. Furthermore, is the CO 2 -tax an environmental success only to the extent it contributes to reductions in the CO 2 emissions globally. The paper indicates that there are possibilities for major suboptimal adaptations in connection with national CO 2 -taxation of the oil and gas production. 13 refs., 6 figs

Greenhouse gas emissions of Dutch biomass. Quantification of greenhouse gases emission of Dutch biomass for electricity and heat

International Nuclear Information System (INIS)

Koop, K.; Yildiz, I.

2010-09-01

The greenhouse gas emissions of all available flows of the biomass chain have been established. This report has the following aims: (1) to establish the greenhouse gas emission of Dutch biomass available for generating electricity and heat; (2) to obtain insight in the opportunities and threats for using the potential of the biomass chains that have the highest potential to reduce greenhouse gas emissions. This report can be seen as a supplement to the report 'Availability of Dutch biomass for electricity and heat in 2020' (2009) [nl

Mitigating gas emissions at signalised intersections using wireless vehicle detectors

Directory of Open Access Journals (Sweden)

Moses Kwasi Torkudzor

2015-09-01

Full Text Available Traffic congestion on roads wastes travel times and increases fuel consumption as well as gas emissions which are dangerous to human health. This has led to growing concern about environmental protection and energy conservation and a number of studies to increase fuel economy and reduce gas emissions. To increase travel times so as to reduce fuel consumption and gas emissions, traffic signals at intersections must be well implemented. It is therefore necessary to employ the current technology of wireless sensor networks to enhance the optimisation of the signalised intersections so as to address such a concern. In this study, a vehicular traffic control model was developed to optimise a signalised intersection, using wireless vehicle detectors. Real-time traffic volume gathered were analysed to obtain the peak hour traffic volume causing congestion. The intersection was modelled and simulated in Synchro7 as an actuated signalised model using results from the analysed data. The model for morning peak and evening peak periods gave optimal cycle lengths which result in the reduction of gas emissions, fuel consumption and delay at the intersection.

Greenhouse gas emissions in an agroforestry system in the southeastern USA

Science.gov (United States)

Agroforestry systems may provide diverse ecosystem services and economic benefits that conventional agriculture cannot, e.g. potentially mitigating greenhouse gas emissions by enhancing nutrient cycling, since tree roots can capture nutrients not taken up by crops. However, greenhouse gas emission ...

Emission-line maps with OSIRIS-TF: The case of M101

Science.gov (United States)

Méndez-Abreu, J.

2013-05-01

We investigate the suitability of GTC/OSIRIS Tunable Filters (TFs) for obtaining emission-line maps of extended objects. We developed a technique to reconstruct an emission-line image from a set of images taken at consecutive central wavelengths. We demonstrate the feasibility of the reconstruction method by generating a flux calibrated Hα image of the well-known spiral galaxy M101. We tested our emission-line fluxes and ratios by using data present in the literature. We found that the differences in both Hα fluxes and N II/Hα line ratios are ~15% and ~50%, respectively. These results are fully in agreement with the expected values for our observational setup. The proposed methodology will allow us to use OSIRIS/GTC to perform accurate spectrophotometric studies of extended galaxies in the local Universe.

Quantifying and reporting greenhouse gas emissions at local level

Directory of Open Access Journals (Sweden)

Sόwka Izabela

2017-01-01

Full Text Available Cities as global centers of consumption and production often are a significant and growing source of greenhouse gas (GHG emissions. At the same time, local authorities are increasingly taking action on climate change by focusing on reducing GHG emissions and efficiency improvement opportunities. To assess and reduce the overall greenhouse gas emission level from an urban area, it is necessary to identify all the activities and processes which generate these emissions. GHG inventory gives an opportunity to get wider knowledge for city’s community about spatial emission processes and emissions contribution of key sources categories at the local scale. Inventory is being used for decision-making purposes and strategic planning in emission reduction policy. The goal of this paper was to clarify the major methodological challenges of GHG monitoring at the urban level. The paper is based on the discussion of different methods and approaches to assessing GHG emissions at the local level. It is presented sectoral GHGs emission trends in selected urban areas and compared CO2 emission level in different countries and metropolises and variable European cities guidance. The study determines the inventory tools of GHGs emission taking into account the characteristics of main sources at local levels.

Molecular hydrogen line ratios in four regions of shock-excited gas

International Nuclear Information System (INIS)

Burton, M.G.

1989-01-01

Five emission lines of molecular hydrogen, with wavelengths in the ranges of 2.10-2.25 and 3.80-3.85 μm, have been observed in four objects of different type in which the line emission is believed to be excited by shocks. (author)

Gas breakthrough and emission through unsaturated compacted clay in landfill final cover

International Nuclear Information System (INIS)

Ng, C.W.W.; Chen, Z.K.; Coo, J.L.; Chen, R.; Zhou, C.

2015-01-01

Highlights: • Explore feasibility of unsaturated clay as a gas barrier in landfill cover. • Gas breakthrough pressure increases with clay thickness and degree of saturation. • Gas emission rate decreases with clay thickness and degree of saturation. • A 0.6 m-thick clay layer may be sufficient to meet gas emission rate limit. - Abstract: Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas–water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different

Gas breakthrough and emission through unsaturated compacted clay in landfill final cover

Energy Technology Data Exchange (ETDEWEB)

Ng, C.W.W.; Chen, Z.K.; Coo, J.L. [Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Chen, R., E-mail: chenrui1005@hotmail.com [Shenzhen Key Laboratory of Urban and Civil Engineering for Disaster Prevention and Mitigation, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055 (China); Zhou, C. [Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2015-10-15

Highlights: • Explore feasibility of unsaturated clay as a gas barrier in landfill cover. • Gas breakthrough pressure increases with clay thickness and degree of saturation. • Gas emission rate decreases with clay thickness and degree of saturation. • A 0.6 m-thick clay layer may be sufficient to meet gas emission rate limit. - Abstract: Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas–water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different

Effects of nitrogen loading on greenhouse gas emissions in salt marshes

Science.gov (United States)

Tang, J.; Moseman-Valtierra, S.; Kroeger, K. D.; Morkeski, K.; Mora, J.; Chen, X.; Carey, J.

2014-12-01

Salt marshes play an important role in global and regional carbon and nitrogen cycling. We tested the hypothesis that anthropogenic nitrogen loading alters greenhouse gas (GHG, including CO2, CH4, and N2O) emissions and carbon sequestration in salt marshes. We measured GHG emissions biweekly for two growing seasons across a nitrogen-loading gradient of four Spartina salt marshes in Waquoit Bay, Massachusetts. In addition, we conducted nitrogen addition experiments in a pristine marsh by adding low and high nitrate to triplicate plots bi-weekly during the summer. The GHG flux measurements were made in situ with a state-of-the-art mobile gas measurement system using the cavity ring down technology that consists of a CO2/CH4 analyzer (Picarro) and an N2O/CO analyzer (Los Gatos). We observed strong seasonal variations in greenhouse gas emissions. The differences in gas emissions across the nitrogen gradient were not significant, but strong pulse emissions of N2O were observed after nitrogen was artificially added to the marsh. Our results will facilitate model development to simulate GHG emissions in coastal wetlands and support methodology development to assess carbon credits in preserving and restoring coastal wetlands.

Combining policy instruments to curb greenhouse gas emissions

International Nuclear Information System (INIS)

Bahn, O.

2001-01-01

The Kyoto Protocol has set greenhouse gas emission reduction targets for selected countries. To comply with these reduction requirements, decision-makers may use market-based instruments on a national or international basis. This paper advocates the combining of national emission taxes with international trade of emission permits. As a numerical application, this paper analyses macro-economic impacts of such a strategy for Switzerland. (Author)

New Constraints on Quasar Broad Absorption and Emission Line Regions from Gravitational Microlensing

Energy Technology Data Exchange (ETDEWEB)

Hutsemékers, Damien; Braibant, Lorraine; Sluse, Dominique [Institut d' Astrophysique et de Géophysique, Université de Liège, Liège (Belgium); Anguita, Timo [Departamento de Ciencias Fisicas, Universidad Andres Bello, Santiago (Chile); Goosmann, René, E-mail: hutsemekers@astro.ulg.ac.be [Observatoire Astronomique de Strasbourg, Université de Strasbourg, Strasbourg (France)

2017-09-29

Gravitational microlensing is a powerful tool allowing one to probe the structure of quasars on sub-parsec scale. We report recent results, focusing on the broad absorption and emission line regions. In particular microlensing reveals the intrinsic absorption hidden in the P Cygni-type line profiles observed in the broad absorption line quasar H1413+117, as well as the existence of an extended continuum source. In addition, polarization microlensing provides constraints on the scattering region. In the quasar Q2237+030, microlensing differently distorts the Hα and CIV broad emission line profiles, indicating that the low- and high-ionization broad emission lines must originate from regions with distinct kinematical properties. We also present simulations of the effect of microlensing on line profiles considering simple but representative models of the broad emission line region. Comparison of observations to simulations allows us to conclude that the Hα emitting region in Q2237+030 is best represented by a Keplerian disk.

New Constraints on Quasar Broad Absorption and Emission Line Regions from Gravitational Microlensing

Directory of Open Access Journals (Sweden)

Damien Hutsemékers

2017-09-01

Full Text Available Gravitational microlensing is a powerful tool allowing one to probe the structure of quasars on sub-parsec scale. We report recent results, focusing on the broad absorption and emission line regions. In particular microlensing reveals the intrinsic absorption hidden in the P Cygni-type line profiles observed in the broad absorption line quasar H1413+117, as well as the existence of an extended continuum source. In addition, polarization microlensing provides constraints on the scattering region. In the quasar Q2237+030, microlensing differently distorts the Hα and CIV broad emission line profiles, indicating that the low- and high-ionization broad emission lines must originate from regions with distinct kinematical properties. We also present simulations of the effect of microlensing on line profiles considering simple but representative models of the broad emission line region. Comparison of observations to simulations allows us to conclude that the Hα emitting region in Q2237+030 is best represented by a Keplerian disk.

The effects of Norwegian gas export on the global CO2 emission

International Nuclear Information System (INIS)

1996-01-01

This report analyses how a limitation of Norway's gas export might affect the global CO 2 emission. In principle, a reduction of this export can lead to decreased or increased CO 2 emission depending on changes in several conditions that individually have conflicting emission effects. What the total effect will be can only become clear after a thorough empirical analysis of the supply and demand structure. The model calculations presented in the report show that the global emission will probably increase if Norway reduces the gas export. A gas export reduction of 10 million tonne oil equivalents in 2015 will increase the global emission by 1.4 and 7.5 million tonne CO 2 depending on the assumption made for alternative gas supplies to the European market and for market conditions in the importing countries. 4 refs., 32 figs., 44 tabs

On-line gas chromatographic analysis of airborne particles

Science.gov (United States)

Hering, Susanne V [Berkeley, CA; Goldstein, Allen H [Orinda, CA

2012-01-03

A method and apparatus for the in-situ, chemical analysis of an aerosol. The method may include the steps of: collecting an aerosol; thermally desorbing the aerosol into a carrier gas to provide desorbed aerosol material; transporting the desorbed aerosol material onto the head of a gas chromatography column; analyzing the aerosol material using a gas chromatograph, and quantizing the aerosol material as it evolves from the gas chromatography column. The apparatus includes a collection and thermal desorption cell, a gas chromatograph including a gas chromatography column, heated transport lines coupling the cell and the column; and a quantization detector for aerosol material evolving from the gas chromatography column.

75 FR 57275 - Information Collection; Supplier Greenhouse Gas Emissions Inventory Pilot

Science.gov (United States)

2010-09-20

...] Information Collection; Supplier Greenhouse Gas Emissions Inventory Pilot AGENCY: Federal Acquisition Service... Greenhouse Gas (GHG) Emissions Inventory pilot. Public comments are particularly invited on: Whether this... Inventory pilot, and whether it will have practical utility; whether our estimate of the public burden of...

Emission quantification using the tracer gas dispersion method: The influence of instrument, tracer gas species and source simulation

DEFF Research Database (Denmark)

Delre, Antonio; Mønster, Jacob; Samuelsson, Jerker

2018-01-01

The tracer gas dispersion method (TDM) is a remote sensing method used for quantifying fugitive emissions by relying on the controlled release of a tracer gas at the source, combined with concentration measurements of the tracer and target gas plumes. The TDM was tested at a wastewater treatment...... plant for plant-integrated methane emission quantification, using four analytical instruments simultaneously and four different tracer gases. Measurements performed using a combination of an analytical instrument and a tracer gas, with a high ratio between the tracer gas release rate and instrument...... precision (a high release-precision ratio), resulted in well-defined plumes with a high signal-to-noise ratio and a high methane-to-tracer gas correlation factor. Measured methane emission rates differed by up to 18% from the mean value when measurements were performed using seven different instrument...

State and Territory Greenhouse Gas Emissions. An overview

International Nuclear Information System (INIS)

2005-04-01

This document is a summary of the latest available estimates of greenhouse gas emissions for the States and Territories. They are taken from the national inventory and show emissions for 2002, the latest year for which national statistics on fuel and electricity consumption are available. The report shows that Australia's total greenhouse gas emissions in 2002 amounted to 541.8 million tonnes. The State and Territory breakdown was: New South Wales: 151.5 million tonnes (Mt); Queensland: 145.1 Mt; Victoria: 117.0 Mt; Western Australia: 70.4 Mt; South Australia: 30.9 Mt; Northern Territory: 17.7 Mt; Tasmania: 7.2 Mt; ACT: 1.3 Mt. The State and Territory inventories are the first of what will be an annual series. The national inventory and State and Territory inventories are all prepared according to the international rules and procedures applicable to Australia's Kyoto 108% emissions target. The national inventory undergoes regular independent international review

Wolf-Rayet stars featured in emission-line galaxies

International Nuclear Information System (INIS)

Kunth, D.

1982-01-01

In the galaxy Tololo 3 (NGC 3125) recent observations by the author and Sargent (1981) have revealed the presence of an unusual strong and broad He II 4686 emission. The origin of this line together with some nitrogen lines (e.g. N V 4620 and N III 4638) is attributed to Wolf-Rayet stars, mostly of WN types. (Auth.)

Greenhouse Gas Emissions in the Netherlands 1990-2011. National Inventory Report 2013

Energy Technology Data Exchange (ETDEWEB)

Coenen, P. W.H.G.; Droege, R. [Netherlands Organisation for Applied Scientific Research TNO, P.O. Box 80015, NL-3508 TA Utrecht (Netherlands); Zijlema, P. J. [NL Agency, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Arets, E. J.M.M. [Alterra Wageningen UR, P.O. Box 47 NL-6700 AA Wageningen (Netherlands); Baas, K. [Statistics Netherlands CBS, P.O. Box 24500, NL-2490 HA Den Haag (Netherlands); Van den Berghe, A. C.W.M. [Rijkswaterstaat, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Brandt, A. T. [Dutch Emissions Authority NEa, P.O. Box 91503, NL-2509 EC Den Haag (Netherlands); Geilenkirchen, G. [PBL Netherlands Environmental Assessment Agency, P.O. Box 303 NL-3720 AH Bilthoven (Netherlands); Van der Maas, C. W.M.; Te Biesebeek, J. D.; Van der Hoek, K. W.; Te Molder, R.; Montfoort, J. A.; Peek, C. J.; Vonk, J. [National Institute of Public Health and Environmental Protection RIVM, Bilthoven (Netherlands)

2013-04-15

Total greenhouse gas emissions from The Netherlands in 2011 decreased by approximately 7 per cent compared with 2010 emissions. This decrease is mainly the result of decreased fuel combustion in the Energy sector (less electricity production) and in the petrochemical industry. Fuel use for space heating decreased due to the mild winter compared with the very cold 2010 winter. In 2011, total direct greenhouse gas emissions (excluding emissions from LULUCF (land use, land use change and forestry) in The Netherlands amounted to 194.4 Tg CO2 eq. This is approximately 9 per cent below the emissions in the base year 2 (213.2 Tg CO2 eq). This report documents the Netherlands' 2012 annual submission of its greenhouse gas emissions inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.

Greenhouse Gas Emissions in the Netherlands 1990-2011. National Inventory Report 2013

Energy Technology Data Exchange (ETDEWEB)

Coenen, P.W.H.G.; Droege, R. [Netherlands Organisation for Applied Scientific Research TNO, P.O. Box 80015, NL-3508 TA Utrecht (Netherlands); Zijlema, P.J. [NL Agency, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Arets, E.J.M.M. [Alterra Wageningen UR, P.O. Box 47 NL-6700 AA Wageningen (Netherlands); Baas, K. [Statistics Netherlands CBS, P.O. Box 24500, NL-2490 HA Den Haag (Netherlands); Van den Berghe, A.C.W.M. [Rijkswaterstaat, P.O. Box 8242, NL-3503 RE Utrecht (Netherlands); Brandt, A.T. [Dutch Emissions Authority NEa, P.O. Box 91503, NL-2509 EC Den Haag (Netherlands); Geilenkirchen, G. [PBL Netherlands Environmental Assessment Agency, P.O. Box 303 NL-3720 AH Bilthoven (Netherlands); Van der Maas, C.W.M.; Te Biesebeek, J.D.; Van der Hoek, K.W.; Te Molder, R.; Montfoort, J.A.; Peek, C.J.; Vonk, J. [National Institute of Public Health and Environmental Protection RIVM, Bilthoven (Netherlands)

2013-04-15

Total greenhouse gas emissions from The Netherlands in 2011 decreased by approximately 7 per cent compared with 2010 emissions. This decrease is mainly the result of decreased fuel combustion in the Energy sector (less electricity production) and in the petrochemical industry. Fuel use for space heating decreased due to the mild winter compared with the very cold 2010 winter. In 2011, total direct greenhouse gas emissions (excluding emissions from LULUCF (land use, land use change and forestry) in The Netherlands amounted to 194.4 Tg CO2 eq. This is approximately 9 per cent below the emissions in the base year 2 (213.2 Tg CO2 eq). This report documents the Netherlands' 2012 annual submission of its greenhouse gas emissions inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.

Localization of fugitive methane emission from natural gas distribution network of Titas Gas

Directory of Open Access Journals (Sweden)

Mandal Pradip C.

2017-03-01

Full Text Available The aim of this paper is to localize the fugitive leaks from the above ground facilities of the existing system of Titas Gas (TG after developing mathematical model for fugitive emission. Soap screening techniques and Gasurveyor 500 series instrument were used in this study for detecting potential leaks. Leaked gas was quantified using either Hi-Flow gas sampler or bagging measurements system. The results show that the respective potential gas leaking point of City Gate Station (CGS, commercial Regulating and Metering Station (RMS, industrial RMS, residential RMS and Town Bordering Station (TBS/ District Regulating Station (DRS are scrubber dump valve (average leak rate 217.00 L/min, insulating point (average leak rate 4.04 L/min, tube fitting connector (average leak rate 8.00 L/min, connector (average leak rate 1.55 L/min and pressure relief valve (average leak rate 437.92 L/min. Fugitive methane emission can be reduced by stopping leaks of fittings or components having high KLeak value.

METHANE EMISSIONS FROM THE NATURAL GAS INDUSTRY VOLUME 15: GAS-ASSISTED GLYCOL PUMPS

Science.gov (United States)

The 15-volume report summarizes the results of a comprehensive program to quantify methane (CH4) emissions from the U.S. natural gas industry for the base year. The objective was to determine CH4 emissions from the wellhead and ending downstream at the customer's meter. The accur...

Improving material management to reduce greenhouse gas emissions

NARCIS (Netherlands)

Hekkert, Marko Peter

2000-01-01

Climate change due to greenhouse gas emissions caused by human actions is probably one of the major global environmental problems that we face today. In order to reduce the risk of climate change and the potential effects thereof, the emission of greenhouse gases like carbon dioxide (CO2) and

Mobile measurement of methane emissions from natural gas developments in northeastern British Columbia, Canada

Science.gov (United States)

Atherton, Emmaline; Risk, David; Fougère, Chelsea; Lavoie, Martin; Marshall, Alex; Werring, John; Williams, James P.; Minions, Christina

2017-10-01

North American leaders recently committed to reducing methane emissions from the oil and gas sector, but information on current emissions from upstream oil and gas developments in Canada are lacking. This study examined the occurrence of methane plumes in an area of unconventional natural gas development in northwestern Canada. In August to September 2015 we completed almost 8000 km of vehicle-based survey campaigns on public roads dissecting oil and gas infrastructure, such as well pads and processing facilities. We surveyed six routes 3-6 times each, which brought us past over 1600 unique well pads and facilities managed by more than 50 different operators. To attribute on-road plumes to oil- and gas-related sources we used gas signatures of residual excess concentrations (anomalies above background) less than 500 m downwind from potential oil and gas emission sources. All results represent emissions greater than our minimum detection limit of 0.59 g s-1 at our average detection distance (319 m). Unlike many other oil and gas developments in the US for which methane measurements have been reported recently, the methane concentrations we measured were close to normal atmospheric levels, except inside natural gas plumes. Roughly 47 % of active wells emitted methane-rich plumes above our minimum detection limit. Multiple sites that pre-date the recent unconventional natural gas development were found to be emitting, and we observed that the majority of these older wells were associated with emissions on all survey repeats. We also observed emissions from gas processing facilities that were highly repeatable. Emission patterns in this area were best explained by infrastructure age and type. Extrapolating our results across all oil and gas infrastructure in the Montney area, we estimate that the emission sources we located (emitting at a rate > 0.59 g s-1) contribute more than 111 800 t of methane annually to the atmosphere. This value exceeds reported bottom

Hydrocarbon emissions from gas engine CHP-units. 2011 measurement program

Energy Technology Data Exchange (ETDEWEB)

Van Dijk, G.H.J. [KEMA, Arnhem (Netherlands)

2012-06-15

In December 2009, the Ministry of Infrastructure and Environment (IandM) issued the Decree on Emission Limits for Middle Sized Combustion Installations (BEMS). This decree imposes a first-time emission limit value (ELV) of 1500 mg C/m{sup 3}{sub o} at 3% O{sub 2} for hydrocarbons emitted by gas engines. IandM used the findings of two hydrocarbon emission measurement programs, executed in 2007 and 2009, as a guideline for this initial ELV. The programs did reveal substantial variation in the hydrocarbon emissions of the gas engines tested. This variation, and especially the uncertainty as to the role of engine and/or other parameters causing such variation, was felt to hamper further policy development. IandM therefore commissioned KEMA to perform follow-up measurements on ten gas engine CHP-units in 2011. Aim of this 2011 program is to assess hydrocarbon emission variation in relation to engine parameters and process conditions including maintenance status, and to atmospheric conditions. The 2011 program comprised two identical measurement sessions, one in spring and one in winter.

Air pollution from industrial waste gas emissions is associated with cancer incidences in Shanghai, China.

Science.gov (United States)

Cong, Xiaowei

2018-05-01

Outdoor air pollution may be associated with cancer risk at different sites. This study sought to investigate outdoor air pollution from waste gas emission effects on multiple cancer incidences in a retrospective population-based study in Shanghai, China. Trends in cancer incidence for males and females and trends in waste gas emissions for the total waste gas, industrial waste gas, other waste gas, SO 2 , and soot were investigated between 1983 and 2010 in Shanghai, China. Regression models after adjusting for confounding variables were constructed to estimate associations between waste gas emissions and multiple cancer incidences in the whole group and stratified by sex, Engel coefficient, life expectancy, and number of doctors per 10,000 populations to further explore whether changes of waste gas emissions were associated with multiple cancer incidences. More than 550,000 new cancer patients were enrolled and reviewed. Upward trends in multiple cancer incidences for males and females and in waste gas emissions were observed from 1983 to 2010 in Shanghai, China. Waste gas emissions came mainly from industrial waste gas. Waste gas emissions was significantly positively associated with cancer incidence of salivary gland, small intestine, colorectal, anus, gallbladder, thoracic organs, connective and soft tissue, prostate, kidney, bladder, thyroid, non-Hodgkin's lymphoma, lymphatic leukemia, myeloid leukemia, and other unspecified sites (all p emissions and the esophagus cancer incidence was observed (p emissions was associated with multiple cancer incidences.

Coal fired flue gas mercury emission controls

CERN Document Server

Wu, Jiang; Pan, Weiguo; Pan, Weiping

2015-01-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of

Fluorescent H{sub 2} Emission Lines from the Reflection Nebula NGC 7023 Observed with IGRINS

Energy Technology Data Exchange (ETDEWEB)

Le, Huynh Anh N.; Pak, Soojong; Lee, Hye-In [School of Space Research, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of); Kaplan, Kyle; Mace, Gregory; Pavel, Michael; Jaffe, Daniel T. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Lee, Sungho; Jeong, Ueejeong; Chun, Moo-Young; Yuk, In-Soo; Hwang, Narae; Kim, Kang-Min; Park, Chan; Oh, Jae Sok; Yu, Young Sam; Park, Byeong-Gon; Minh, Young Chol [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Oh, Heeyoung [Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826 (Korea, Republic of); Pyo, Tae-Soo, E-mail: huynhanh7@khu.ac.kr, E-mail: soojong@khu.ac.kr [Subaru Telescope, National Astronomical Observatory of Japan, National Institutes of Natural Sciences (NINS), 650 North Aohoku Place, Hilo, HI 96720 (United States)

2017-05-20

We have analyzed the temperature, velocity, and density of H{sub 2} gas in NGC 7023 with a high-resolution near-infrared spectrum of the northwestern filament of the reflection nebula. By observing NGC 7023 in the H and K bands at R ≃ 45,000 with the Immersion GRating INfrared Spectrograph, we detected 68 H{sub 2} emission lines within the 1″ × 15″ slit. The diagnostic ratio of 2-1 S(1)/1-0 S(1) is 0.41−0.56. In addition, the estimated ortho-to-para ratio (OPR) is 1.63−1.82, indicating that the H{sub 2} emission transitions in the observed region arise mostly from gas excited by UV fluorescence. Gradients in the temperature, velocity, and OPR within the observed area imply motion of the photodissociation region (PDR) relative to the molecular cloud. In addition, we derive the column density of H{sub 2} from the observed emission lines and compare these results with PDR models in the literature covering a range of densities and incident UV field intensities. The notable difference between PDR model predictions and the observed data, in high rotational J levels of ν = 1, is that the predicted formation temperature for newly formed H{sub 2} should be lower than that of the model predictions. To investigate the density distribution, we combine pixels in 1″ × 1″ areas and derive the density distribution at the 0.002 pc scale. The derived gradient of density suggests that NGC 7023 has a clumpy structure, including a high clump density of ∼10{sup 5} cm{sup −3} with a size smaller than ∼5 × 10{sup −3} pc embedded in lower-density regions of 10{sup 3}–10{sup 4} cm{sup −3}.

Emission Characteristics of Gas-Fired Boilers based on Category-Specific Emission Factor from Field Measurements in Beijing, China

Science.gov (United States)

Itahashi, S.; Yan, X.; Song, G.; Yan, J.; Xue, Y.

2017-12-01

Gas-fired boilers will become the main stationary sources of NOx in Beijing. However, the knowledge of gas-fired boilers in Beijing is limited. In the present study, the emission characteristics of NOx, SO2, and CO from gas-fired boilers in Beijing were established using category-specific emission factors (EFs) from field measurements. In order to obtain category-specific EFs, boilers were classified through influence analysis. Factors such as combustion mode, boiler type, and installed capacity were considered critical for establishing EFs because they play significant roles in pollutant formation. The EFs for NOx, CO, and SO2 ranged from 1.42-6.86 g m-3, 0.05-0.67 g m-3 and 0.03-0.48 g m-3. The emissions of NOx, SO2, and CO for gas-fired boilers in Beijing were 11121 t, 468 t, and 222 t in 2014, respectively. The emissions were spatially allocated into grid cells with a resolution of 1 km × 1 km, and the results indicated that top emitters were in central Beijing. The uncertainties were quantified using a Monte Carlo simulation. The results indicated high uncertainties in CO (-157% to 154%) and SO2 (-127% to 182%) emissions, and relatively low uncertainties (-34% to 34%) in NOx emission. Furthermore, approximately 61.2% and 96.8% of the monitored chamber combustion boilers (CCBs) met the standard limits for NOx and SO2, respectively. Concerning NOx, low-NOx burners and NOx emission control measures are urgently needed for implementing of stricter standards. Adopting terminal control measures is unnecessary for SO2, although its concentration occasionally exceeds standard limits, because reduction of its concentration can be achieved thorough control of the sulfur content of natural gas at a stable low level. Furthermore, the atmospheric combustion boilers (ACBs) should be substituted with CCBs, because ACBs have a higher emission despite lower gross installed capacity. The results of this study will enable in understanding and controlling emissions from gas

Embodied greenhouse gas emission by Macao

International Nuclear Information System (INIS)

Li, J.S.; Chen, G.Q.; Lai, T.M.; Ahmad, B.; Chen, Z.M.; Shao, L.; Ji, Xi

2013-01-01

Comprehensive inventory of cities' greenhouse gas emissions (GHG) is the basis for cities to make appropriate mitigation plans. However, previous studies on cities' GHG emissions consider emissions occurring within the city boundary (Scope 1) and out of boundary electricity emissions (Scope 2), but neglect indirect emissions associated with commodities consumed by cities (Scope 3), resulting in emission leakage. To cope with this problem, a systematic accounting covering all 3 scopes is presented in a case study of Macao for the years 2005–2009, based on the latest embodied emission intensity databases for China and for the world. The results show that total emissions are dominated by indirect emissions mainly embodied in imports, which is 3–4 times direct emissions during the period concerned. It is verified that accounting under Scopes 1 and 2 cannot capture the full picture of cities' emissions, especially cities like Macao which are dominated by service industry and inevitably sustained by massive materials and services from other regions. Our study suggests that Macao should adjust its current GHG mitigation policies which consider only its emissions occurring within its border, as Macao is a net GHG emissions importer. This work is the first assessment of Macao's embodied GHG emissions. - Highlights: • A systematic accounting procedure is presented to inventory a city's GHG emissions. • A comprehensive review of GHG emissions is performed for Macao. • Indirect GHG emissions dominate Macao's embodied GHG emissions. • Macao induced large amount of GHG emissions in other regions through trade. • The variation in GHG emission structure against socio-economic changes is revealed

Laser-induced breakdown spectroscopy at a water/gas interface: A study of bath gas-dependent molecular species

International Nuclear Information System (INIS)

Adamson, M.; Padmanabhan, A.; Godfrey, G.J.; Rehse, S.J.

2007-01-01

Single-pulse laser-induced breakdown spectroscopy has been performed on the surface of a bulk water sample in an air, argon, and nitrogen gas environment to investigate emissions from hydrogen-containing molecules. A microplasma was formed at the gas/liquid interface by focusing a Nd:YAG laser beam operating at 1064 nm onto the surface of an ultra-pure water sample. A broadband Echelle spectrometer with a time-gated intensified charge-coupled device was used to analyze the plasma at various delay times (1.0-40.0 μs) and for incident laser pulse energies ranging from 20-200 mJ. In this configuration, the dominant atomic spectral features at short delay times are the hydrogen H-alpha and H-beta emission lines at 656 and 486 nm, respectively, as well as emissions from atomic oxygen liberated from the water and air and nitrogen emission lines from the air bath gas. For delay times exceeding approximately 8 μs the emission from molecular species (particularly OH and NH) created after the ablation process dominates the spectrum. Molecular emissions are found to be much less sensitive to variations in pulse energy and exhibit a temporal decay an order of magnitude slower than the atomic emission. The dependence of both atomic hydrogen and OH emission on the bath gas above the surface of the water was studied by performing the experiment at standard pressure in an atmospheric purge box. Electron densities calculated from the Stark broadening of the H-beta and H-gamma lines and plasma excitation temperatures calculated from the ratio of H-beta to H-gamma emission were measured for ablation in the three bath gases

Assessing fugitive emissions of CH4 from high-pressure gas pipelines

Science.gov (United States)

Worrall, Fred; Boothroyd, Ian; Davies, Richard

2017-04-01

The impact of unconventional natural gas production using hydraulic fracturing methods from shale gas basins has been assessed using life-cycle emissions inventories, covering areas such as pre-production, production and transmission processes. The transmission of natural gas from well pad to processing plants and its transport to domestic sites is an important source of fugitive CH4, yet emissions factors and fluxes from transmission processes are often based upon ver out of date measurements. It is important to determine accurate measurements of natural gas losses when compressed and transported between production and processing facilities so as to accurately determine life-cycle CH4 emissions. This study considers CH4 emissions from the UK National Transmission System (NTS) of high pressure natural gas pipelines. Mobile surveys of CH4 emissions using a Picarro Surveyor cavity-ring-down spectrometer were conducted across four areas in the UK, with routes bisecting high pressure pipelines and separate control routes away from the pipelines. A manual survey of soil gas measurements was also conducted along one of the high pressure pipelines using a tunable diode laser. When wind adjusted 92 km of high pressure pipeline and 72 km of control route were drive over a 10 day period. When wind and distance adjusted CH4 fluxes were significantly greater on routes with a pipeline than those without. The smallest leak detectable was 3% above ambient (1.03 relative concentration) with any leaks below 3% above ambient assumed ambient. The number of leaks detected along the pipelines correlate to the estimated length of pipe joints, inferring that there are constant fugitive CH4 emissions from these joints. When scaled up to the UK's National Transmission System pipeline length of 7600 km gives a fugitive CH4 flux of 4700 ± 2864 kt CH4/yr - this fugitive emission from high pressure pipelines is 0.016% of the annual gas supply.

Modeling of municipal greenhouse gas emissions. Calculation of greenhouse gas emissions and the reduction possibilities of Dutch municipalities

NARCIS (Netherlands)

Vries de, Willem

2011-01-01

Summary Municipalities represent an active governmental layer in the Netherlands. They often have ambitions to reduce greenhouse gas emissions. In this way the municipalities take responsibility to reduce the threat of global warming. To implement effect

A DEEP X-RAY VIEW OF THE BARE AGN ARK 120. I. REVEALING THE SOFT X-RAY LINE EMISSION

Energy Technology Data Exchange (ETDEWEB)

Reeves, J. N.; Braito, V. [Center for Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Porquet, D. [Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France); Nardini, E. [Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire, ST5 5BG (United Kingdom); Lobban, A. [Dept of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Turner, T. J., E-mail: jreeves@umbc.edu, E-mail: j.n.reeves@keele.ac.uk [Department of Physics, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

2016-09-10

The Seyfert 1 galaxy Ark 120 is a prototype example of the so-called class of bare nucleus active galactic nuclei (AGNs), whereby there is no known evidence for the presence of ionized gas along the direct line of sight. Here deep (>400 ks exposure), high-resolution X-ray spectroscopy of Ark 120 is presented from XMM-Newton observations that were carried out in 2014 March, together with simultaneous Chandra /High Energy Transmission Grating exposures. The high-resolution spectra confirmed the lack of intrinsic absorbing gas associated with Ark 120, with the only X-ray absorption present originating from the interstellar medium (ISM) of our own Galaxy, with a possible slight enhancement of the oxygen abundance required with respect to the expected ISM values in the solar neighborhood. However, the presence of several soft X-ray emission lines are revealed for the first time in the XMM-Newton RGS spectrum, associated with the AGN and arising from the He- and H-like ions of N, O, Ne, and Mg. The He-like line profiles of N, O, and Ne appear velocity broadened, with typical FWHMs of ∼5000 km s{sup −1}, whereas the H-like profiles are unresolved. From the clean measurement of the He-like triplets, we deduce that the broad lines arise from a gas of density n {sub e} ∼ 10{sup 11} cm{sup −3}, while the photoionization calculations infer that the emitting gas covers at least 10% of 4 π steradian. Thus the broad soft X-ray profiles appear coincident with an X-ray component of the optical–UV broad-line region on sub-parsec scales, whereas the narrow profiles originate on larger parsec scales, perhaps coincident with the AGN narrow-line region. The observations show that Ark 120 is not intrinsically bare and substantial X-ray-emitting gas exists out of our direct line of sight toward this AGN.

Incorporating greenhouse gas (GHG) emissions in long range transportation planning.

Science.gov (United States)

2014-05-01

Greenhouse gas (GHG) emissions continue to be an important focus area for state, local, and federal : agencies. The transportation sector is the second biggest contributor to GHG emissions in the U.S., and : Texas contributes the highest emissions am...

Optimal greenhouse gas emissions in NGCC plants integrating life cycle assessment

International Nuclear Information System (INIS)

Bernier, Etienne; Maréchal, François; Samson, Réjean

2012-01-01

The optimal design of an energy-intensive process involves a compromise between costs and greenhouse gas emissions, complicated by the interaction between optimal process emissions and supply chain emissions. We propose a method that combines generic abatement cost estimates and the results of existing (LCA) life cycle assessment studies, so that supply chain emissions are properly handled during optimization. This method is illustrated for a (NGCC) natural gas combined cycle power plant model with the following design and procurement options: procurement of natural gas from low-emissions producers, fuel substitution with (SNG) synthetic natural gas from wood, and variable-rate CO 2 capture and sequestration from both the NGCC and SNG plants. Using multi-objective optimization, we show two Pareto-optimal sets with and without the proposed LCA method. The latter can then be shown to misestimate CO 2 abatement costs by a few percent, penalizing alternate fuels and energy-efficient process configurations and leading to sub-optimal design decisions with potential net losses of the order of $1/MWh. Thus, the proposed LCA method can enhance the economic analysis of emissions abatement technologies and emissions legislation in general. -- Highlights: ► Multi-objective optimization and LCA used for process design considering supply chain. ► Off-site emissions in LCA reveal potential future indirect taxes for energy consumers. ► Generic abatement cost curves provide a mitigation model for off-site emissions. ► Off-site mitigation precedes CO 2 capture or biogas substitution in NGCC plant. ► Profitability estimation of capture or substitution depends on off-site mitigation.

Greenhouse gas emissions from the production and use of alternative transport fuels

International Nuclear Information System (INIS)

Le Cornu, J.K.

1990-01-01

A number of the commonly proposed alternative transport fuels were ranked according to both the cumulative greenhouse gas emissions and the production costs incurred between the recovery of the prime resource and the fuel's end use by the Australian transport fleet. An examination of the emissions of each greenhouse gas at each production stage confirmed the common presumption that the low levels of secondary greenhouse gas emissions involved contribute little to the overall greenhouse impact of a fuel's production and use. From a greenhouse point of view the transport fuels studied could be reasonable well ranked by considering their carbon dioxide emissions alone. A possible exception may apply in the case of the compressed natural gas option, which may need to separate consideration of the effect of fugitive emissions of methane from gas distribution systems. An assumption involved in reaching this result was that nitrous oxide emissions, on which there was inadequate hard data, would not form more than 1% of the total nitrogen oxide emissions. At such an emission level it could contribute up to 5% of a fuel's total greenhouse impact. It is concluded that apart from some small niche opportunities, there is no Australian alternative transport fuel option whose production cost and greenhouse impact makes it one which policy should favour over other fuels. It is stressed that this is no more than a preliminary scouting study of generic options, which addresses only greenhouse issues. 17 refs., 1 tab., 8 figs

How to globally reduce the greenhouse gas emissions from sewage systems?

International Nuclear Information System (INIS)

Batz, S. de; Bonardet, P.; Trouve, J.P.

2007-01-01

A reliable and exhaustive measurement of the global greenhouse gas emissions from a given sewage plant must be performed prior to the implementation of any abatement measure. The method presented in this paper takes into consideration both the direct emissions but also the indirect ones generated by the plant activity and identified using a life cycle-type approach. Three examples of projects or realizations are presented in this paper to illustrate the different means of abatement of greenhouse gas emissions from a sewage plant in a global way. The first example concerns a project of abatement of the electricity consumption of a plant for sludges and fats digestion and biogas valorization. A 85% global abatement of CO 2 emissions is obtained thanks to the substitution of the aerobic digestion process by an anaerobic one. The second example presents an optimization of the greenhouse gas emissions of the municipal sewage plant of Valenton (Paris region) thanks to a valorization of sludges as fertilizers and fuels and to the recovery of the process heat. The last example concerns the Seine-aval sewage plant which gathers several projects of improvement: setting up of a second biogas turbine, redesign of the heat loop, use of river transport for a significant abatement of greenhouse gas emissions. (J.S.)

Cradle to grave GHG emissions analysis of shale gas hydraulic fracking in Western Australia

Directory of Open Access Journals (Sweden)

Bista Sangita

2017-01-01

Full Text Available Western Australia has globally significant onshore gas resources, with over 280 trillion cubic feet of economically recoverable gas located in five shale basins. The Western Australian Government and gas industry have promoted the development of these resources as a “clean energy source” that would “help to reduce global carbon emissions” and provide a “transition fuel” to a low carbon economy. This research examines those claims by reviewing existing literature and published data to estimate the life cycle greenhouse gas (GHG pollution that would result from the development of Western Australia’s onshore gas basins using hydraulic fracking. Estimates of carbon pollution from each stage in gas development, processing, transport and end-use are considered in order to establish total life-cycle emissions in tonnes of carbon-dioxide equivalent (CO2e. The emissions estimates draw from published research on emissions from shale gas development in other jurisdictions as well as industry or government reported emissions from current technology for gas processing and end-use as applicable. The current policy and regulatory environment for carbon pollution and likely resulting GHG mitigation measures has also been considered, as well as the potential for the gas to displace or substitute for other energy sources. In areas where there is uncertainty, conservative emissions estimates have been used. Modelling of GHG emissions has been undertaken for two comparison resource development and utilisation scenarios; Australian domestic and 100% export i.e. no domestic use. Each scenario corresponds to a different proportionate allocation of emissions accounted for domestic emissions in Australia and emissions accounted for in other jurisdictions. Emissions estimates for the two scenarios are 245–502 MTCO2e/year respectively over a resource development timeframe of 20 years. This is roughly the same as Australia’s total GHG emissions in 2014

Methane Emissions from the Natural Gas Transmission and Storage System in the United States.

Science.gov (United States)

Zimmerle, Daniel J; Williams, Laurie L; Vaughn, Timothy L; Quinn, Casey; Subramanian, R; Duggan, Gerald P; Willson, Bryan; Opsomer, Jean D; Marchese, Anthony J; Martinez, David M; Robinson, Allen L

2015-08-04

The recent growth in production and utilization of natural gas offers potential climate benefits, but those benefits depend on lifecycle emissions of methane, the primary component of natural gas and a potent greenhouse gas. This study estimates methane emissions from the transmission and storage (T&S) sector of the United States natural gas industry using new data collected during 2012, including 2,292 onsite measurements, additional emissions data from 677 facilities and activity data from 922 facilities. The largest emission sources were fugitive emissions from certain compressor-related equipment and "super-emitter" facilities. We estimate total methane emissions from the T&S sector at 1,503 [1,220 to 1,950] Gg/yr (95% confidence interval) compared to the 2012 Environmental Protection Agency's Greenhouse Gas Inventory (GHGI) estimate of 2,071 [1,680 to 2,690] Gg/yr. While the overlap in confidence intervals indicates that the difference is not statistically significant, this is the result of several significant, but offsetting, factors. Factors which reduce the study estimate include a lower estimated facility count, a shift away from engines toward lower-emitting turbine and electric compressor drivers, and reductions in the usage of gas-driven pneumatic devices. Factors that increase the study estimate relative to the GHGI include updated emission rates in certain emission categories and explicit treatment of skewed emissions at both component and facility levels. For T&S stations that are required to report to the EPA's Greenhouse Gas Reporting Program (GHGRP), this study estimates total emissions to be 260% [215% to 330%] of the reportable emissions for these stations, primarily due to the inclusion of emission sources that are not reported under the GHGRP rules, updated emission factors, and super-emitter emissions.

MID-INFRARED ATOMIC FINE-STRUCTURE EMISSION-LINE SPECTRA OF LUMINOUS INFRARED GALAXIES: SPITZER/IRS SPECTRA OF THE GOALS SAMPLE

Energy Technology Data Exchange (ETDEWEB)

Inami, H. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Armus, L.; Stierwalt, S.; Díaz-Santos, T.; Surace, J.; Howell, J.; Marshall, J. [Spitzer Science Center, California Institute of Technology, CA 91125 (United States); Charmandaris, V. [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece); Groves, B. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Kewley, L. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Petric, A. [Department of Astronomy, California Institute of Technology, MS 320-47, Pasadena, CA 91125 (United States); Rich, J. [The Observatories, Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Haan, S. [CSIRO Astronomy and Space Science, Marsfield, NSW 2122 (Australia); Evans, A. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Mazzarella, J.; Lord, S. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Appleton, P. [NASA Herschel Science Center, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Spoon, H. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Frayer, D. [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Matsuhara, H., E-mail: inami@noao.edu [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (Japan); and others

2013-11-10

We present the data and our analysis of mid-infrared atomic fine-structure emission lines detected in Spitzer/Infrared Spectrograph high-resolution spectra of 202 local Luminous Infrared Galaxies (LIRGs) observed as part of the Great Observatories All-sky LIRG Survey (GOALS). We readily detect emission lines of [S IV], [Ne II], [Ne V], [Ne III], [S III]{sub 18.7{sub μm}}, [O IV], [Fe II], [S III]{sub 33.5{sub μm}}, and [Si II]. More than 75% of these galaxies are classified as starburst-dominated sources in the mid-infrared, based on the [Ne V]/[Ne II] line flux ratios and equivalent width of the 6.2 μm polycyclic aromatic hydrocarbon feature. We compare ratios of the emission-line fluxes to those predicted from stellar photo-ionization and shock-ionization models to constrain the physical and chemical properties of the gas in the starburst LIRG nuclei. Comparing the [S IV]/[Ne II] and [Ne III]/[Ne II] line ratios to the Starburst99-Mappings III models with an instantaneous burst history, the emission-line ratios suggest that the nuclear starbursts in our LIRGs have ages of 1-4.5 Myr, metallicities of 1-2 Z{sub ☉}, and ionization parameters of 2-8 × 10{sup 7} cm s{sup –1}. Based on the [S III]{sub 33.5{sub μm}}/[S III]{sub 18.7{sub μm}} ratios, the electron density in LIRG nuclei is typically one to a few hundred cm{sup –3}, with a median electron density of ∼300 cm{sup –3}, for those sources above the low density limit for these lines. We also find that strong shocks are likely present in 10 starburst-dominated sources of our sample. A significant fraction of the GOALS sources (80) have resolved neon emission-line profiles (FWHM ≥600 km s{sup –1}) and five show clear differences in the velocities of the [Ne III] or [Ne V] emission lines, relative to [Ne II], of more than 200 km s{sup –1}. Furthermore, six starburst and five active galactic nucleus dominated LIRGs show a clear trend of increasing line width with ionization potential

Line Emission and X-ray Line Polarization of Multiply Ionized Mo Ions

Science.gov (United States)

Petkov, E. E.; Safronova, A. S.; Kantsyrev, V. L.; Shlyaptseva, V. V.; Stafford, A.; Safronova, U. I.; Shrestha, I. K.; Schultz, K. A.; Childers, R.; Cooper, M. C.; Beiersdorfer, P.; Hell, N.; Brown, G. V.

2016-10-01

We present a comprehensive experimental and theoretical study of the line emission from multiply ionized Mo ions produced by two different sets of experiments: at LLNL EBIT and the pulsed power generator Zebra at UNR. Mo line emission and polarization measurements were accomplished at EBIT for the first time. In particular, benchmarking experiments at the LLNL EBIT with Mo ions produced at electron beam energies from 2.75 keV up to 15 keV allowed us to break down these very complicated spectra into spectra with only few ionization stages and to select processes that influence them as well as to measure line polarization. The EBIT data were recorded using the EBIT Calorimeter Spectrometer and a crystal spectrometer with a Ge crystal. X-ray Mo spectra and pinhole images were collected from Z-pinch plasmas produced from various wire loads. Non-LTE modeling, high-precision relativistic atomic and polarization data were used to analyze L-shell Mo spectra. The influence of different plasma processes including electron beams on Mo line radiation is summarized. This work was supported by NNSA under DOE Grant DE-NA0002954. Experiments at the NTF/UNR were funded in part by DE-NA0002075. Work at LLNL was performed under the auspices of the U.S. DOE under contract DE-AC52-07NA27344.

Using the van der Waals broadening of the spectral atomic lines to measure the gas temperature of an argon microwave plasma at atmospheric pressure

International Nuclear Information System (INIS)

Yubero, C.; Dimitrijevic, M.S.; Garcia, M.C.; Calzada, M.D.

2007-01-01

The ro-vibrational emission spectra of the molecular species are usually used to measure the gas temperature of a discharge at atmospheric pressure. However, under some experimental conditions, it is difficult to detect them. In order to overcome this difficulty and obtain the temperature, there are methods based on the relation between the gas temperature and the van der Waals broadening of argon atomic spectral lines with a Stark contribution negligible. In this work, we propose a method based on this relation but for lines with a Stark broadening comparable with the van der Waals one

Greenhouse gas emissions trading: Cogen case studies in the early trading market

International Nuclear Information System (INIS)

Buerer, Mary Jean

2001-01-01

An increasing number of companies are interested in opportunities to trade their reduction in greenhouse gas emissions from cogeneration on the emerging greenhouse gas emissions market. Only the UK and Denmark currently have emissions trading schemes, but they are under development in other European countries. Two frameworks currently exist for trading. Baseline-and-credit trading is used in Canada where companies can take part in two voluntary schemes (Greenhouse Gas Emission Reduction Trading Pilot or Clean Air Canada Inc). An example project from the CHP unit at DuPont's Maitland chemical production facility is given, with details of the baselines and calculations used. The other option is company-wide emissions trading. The example given here features the CHP units at BP's refinery and chemicals operations in Texas. The potential revenue from emission reduction projects could help to boost the economics of cogeneration projects

Analyais of solar X-ray emission line profiles

International Nuclear Information System (INIS)

Burek, A.J.; Marrus, D.M.; Blake, R.L.; Fenimore, E.E.

1981-01-01

We report results of the analysis of the X-ray emission line profiles for the Ne X La and Fe XVII 4d 1 P 1 lines produced in an active region that was undergoing a radio and X-ray gradual rise and fall (GRF) in intensity. The spectra were obtained with collimated Bragg spectrometers launched on a rocket from White Sands Missile Range on 1976 March 26. Using a crystal of ammonium acid phthalate, we have fully resolved the Ne X La and Fe XVII 4d 1 P 1 lines, permitting an accurate determinination of the Ne X La intensity and allowing Doppler broadened profiles for lines formed from ions having greatly different atomic mass and charge to be measured. An isothermal model derived from the Ne IX/Ne X resonance line intensity ratio gives an electron temperature of 3.4 x 10 6 K. An isothermal model, however, fails to account for the intensities of all lines and continuum observed. All multitemperature models that do reproduce the observed relative line intensities require the presence of a hot plasma component with an electron temperature in excess of 5 x 10 6 K. The presence of a high temperature component is also suggested by the measured line to continuum ratio of 3.6 in the 12--15 A wavelength interval. Interpretation of the line profiles in terms of a multitemperature model requires an rms turbulence velocity of 48 +- 15 km s -1 for Fe XVII 1 P 1 and 74 +- 54 km s - 2exclamation for Ne X La at the 95% confidence level. Collimated scans across the active region show the presence of a compact source of intense X-ray emission close to the magnetic neutral line, which is very probably the GRF plasma

Greenhouse gas emissions of pilot buildings in 2009-2011; Pilottikiinteistoejen kasvihuonekaasupaeaestoet vuosina 2009-2011

Energy Technology Data Exchange (ETDEWEB)

Riihimaki, M.

2012-07-01

The Julia 2030 use of premises project sought to reduce the greenhouse gas emissions of selected pilot buildings by 10 per cent over the period from 2009 to 2011 by changing patterns of use. The project also provided an opportunity for further refinement of a climate calculator developed and maintained by WWF for reckoning greenhouse gas emissions of this kind. The use of premises project covered a total of 32 pilot buildings in Helsinki, Espoo, Vantaa, Kauniainen, Kirkkonummi and Kerava. These buildings included nurseries and schools, swimming baths, offices, multi-purpose activity buildings, depots, a sports hall and a health centre. The combined greenhouse gas emissions of the pilot buildings in 2011 amounted to 10,416 tCO{sub 2}e, which was 8 per cent lower than the total of 11,293 tCO{sub 2}e recorded in 2009. This means that the project fell slightly short of its targeted 10 per cent reduction in greenhouse gas emissions. The total greenhouse gas emissions of the pilot buildings adjusted for heating requirement amounted to 10,733 tCO{sub 2}e in 2011, which was about 7 per cent lower than in 2009. Reckoned on a per capita basis for employees or visitors, the total greenhouse gas emissions adjusted for heating requirement fell in 25 buildings, but increased in seven buildings over the period from 2009 to 2011. Particularly significant emission reductions were achieved in Vantaa, where all buildings were able to cut their emissions by between 9 and 45 per cent. The principal cause of greenhouse gas emissions in the pilot buildings was heating consumption, which also accounts for the increase in their unadjusted greenhouse gas emissions over the cold winters of 2009 and 2010. The second most important emission source in the pilot buildings was electricity consumption. Air travel contributed significantly to the overall greenhouse gas emissions of the pilot buildings used by employees taking work-related flights, whereas the contribution of paper consumption and

Are greenhouse gas emissions from international shipping a type of marine pollution?

Science.gov (United States)

Shi, Yubing

2016-12-15

Whether greenhouse gas emissions from international shipping are a type of marine pollution is a controversial issue and is currently open to debate. This article examines the current treaty definitions of marine pollution, and applies them to greenhouse gas emissions from ships. Based on the legal analysis of treaty definitions and relevant international and national regulation on this issue, this article asserts that greenhouse gas emissions from international shipping are a type of 'conditional' marine pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of gas emission from the internal chambers of cryogenic equipment

International Nuclear Information System (INIS)

Matyash, Y.I.; Fel'dman, R.G.; Ivakhnenko, Z.N.; Myasnikov, V.M.

1986-01-01

One of the methods of improving the efficiency of cryogenic gas equipment (CGE) is adsorption purification of the working medium. The type and quantity of adsorben can be decided after knowing the qualitative and quantitative nature of gas emissions. Gas emissions were studied by the chromatographic method using a heat-conduction detectory. This method made it possible to determine simultaneously the impurities which differ significantly in terms of physicochemical properties. It was established that carbon dioxide and hydrocarbons are continuously emitted in the gaseous medium of the CGE at a constant rate. For the type of machine which was studied, the rates of gas emission were as follows: carbon dioxide and ethane - 0.2 mg/h; ethylene and methane - 0.1 mg/h; propylene, N-butane, and isobutane - 0.2 mg/h

A Link Between X-ray Emission Lines and Radio Jets in 4U 1630-47?

Science.gov (United States)

Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Lee, Julia C.; Ponti, Gabriele; Tzioumis, A.; Edwards, Phillip; Broderick, Jess

2014-06-01

Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. We present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find a strong disk wind but no evidence for any relativistic X-ray emission lines. Indeed, despite ˜5× brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ˜20× weaker than the line observed by Díaz Trigo et al. Thus we can conclusively say that radio emission is not universally associated with relativistically Doppler-shifted emission lines in 4U 1630-47. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby ISM, in which case the X-ray emission lines might be unrelated to the radio emission.

A national inventory of greenhouse gas (GHG), criteria air contaminants (CAC) and hydrogen sulphide (H2S) emissions by the upstream oil and gas industry : volume 1, overview of the GHG emissions inventory : technical report

International Nuclear Information System (INIS)

2004-09-01

A detailed inventory of greenhouse gas (GHG) emissions from the upstream oil and gas sector in Canada was presented along with explanations of the methodologies and data sources used. This report is based on previous work done on methane and volatile organic compound emissions from the upstream oil and gas sector for the period of 1990 to 1995, but it includes key improvements in identifying primary types of emissions sources such as emissions from fuel combustion, flaring, venting, fugitive equipment leaks and accidental releases. It also includes criteria air contaminants and hydrogen sulfide emissions, an analysis of GHG emission intensities and a change in the definition of volatile organic compounds from comprising all non-methane hydrocarbons to comprising all non-methane and non-ethane hydrocarbons. The report covers portions of the upstream oil and gas industry in Canada plus the natural gas transmission and natural gas distribution industries with reference to well drilling, oil production, and natural gas production, processing, transmission and distribution. Accidents and equipment failures are also included. The report reveals the total GHG emissions by source type, sub-sector, facility type and sub-type for the year 2000 at the national level. In 2000, the total carbon dioxide equivalent GHG emissions from the entire oil and gas sector were 101,211 kilo tonnes. For the upstream oil and gas sector alone, total GHG emissions were 84,355 kilo tonnes, representing 12 per cent of Canada's total national emissions of GHGs in 2000. This is an increase of about 25 per cent from 1995 levels. The biggest primary source of these emissions is fuel combustion, which accounts for 40.8 per cent of the total. This report also includes a provincial breakdown of GHG emissions for the natural gas transmission, storage and distribution sub-sectors in Canada for the year 2000. refs., tabs., figs

REDUCING GREENHOUSE GAS EMISSIONS AND THE INFLUENCES ON ECONOMIC DEVELOPMENT

Directory of Open Access Journals (Sweden)

ANGHELUȚĂ PETRICĂ SORIN

2016-06-01

Full Text Available In the recent years, there has been observed a degradation of the environment. This has negative effects on human activities. Besides the influence of the environment on people, also the economic crisis had a negative contribution. The imbalances manifested in the environment influence the economic systems. This article presents an analysis of the greenhouse gas emissions. Also, there is a link between the greenhouse gas emissions and the economic development. In the situation in which the environmental pollution is increasingly affecting humanity, the transition to an economy with reduced greenhouse gas emissions appears to be a viable solution. This transition provides a number of opportunities, as well. Therefore, one of these opportunities is the one related to the employment. In this regard, retraining people working in polluting industries is very important

Millimeter emission lines in Orion A

International Nuclear Information System (INIS)

Lovas, F.J.; Johnson, D.R.; Buhl, D.; Snyder, L.E.

1976-01-01

During the course of a search of Orion A for signals from three large, organic molecules, several millimeter wave lines from known interstellar molecules were observed. Results of observations on methanol (CH 3 OH), methyl cyanide (CH 3 CN), methyl acetylene (CH 3 CCH), acetaldehyde (CH 3 CHO) and 29 SiO are reported here. Emission signals from two hydrogen recombination lines (H41α and H42α) detected from the H II region of Orion A are also reported. Negative results were obtained for several millimeter wave transitions of ethylene oxide (CH 2 OCH 2 ), acetone [(CH 3 ) 2 CO], and cyclopropenone (HCCOCH)

Spectrum analysis of national greenhouse gas emission: a case study of Germany

International Nuclear Information System (INIS)

Su, Meirong; Pauleit, Stephan; Xu, Chao

2016-01-01

It is essential to abstract the key information from accounting results of greenhouse gas (GHG) emissions because it can provide a highly generalized and clear picture of GHG emissions, which is especially helpful for the public and policy makers. To clearly display the composition of GHG emissions, the concept of spectrum analysis is introduced and defined in this paper. Next, a multilayer analysis framework for national GHG emissions was proposed, which is represented by a pyramid of three layers: total emissions (first layer), emissions decomposed by gas type or sector (second layer), and emissions decomposed by both gas type and sector (third layer). Based on the analysis results from the first to third layers, the main compositional information of national GHG emissions was gradually summarized and analyzed until a spectrum of GHG emissions was acquired. The spectrum of GHG emissions displays the compositional structure of national GHG emissions in the different layers, which is helpful in identifying priorities for emissions reduction. A case study of Germany's GHG emissions during 1990-2012 was conducted, which indicated that CO_2 and the energy sector were the biggest contributors to the total GHG emissions. Some suggestions for reducing GHG emissions are offered based on the obtained results. And the potential development of spectrum analysis for GHG emissions is also expected from aspects of both research and technology. (orig.)

Spectrum analysis of national greenhouse gas emission: a case study of Germany

Energy Technology Data Exchange (ETDEWEB)

Su, Meirong [Dongguan University of Technology, School of Chemistry and Environmental Engineering, Dongguan, Guangdong Province (China); Beijing Normal University, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing (China); Technical University of Munich, Strategic Landscape Planning and Management, Freising (Germany); Pauleit, Stephan; Xu, Chao [Technical University of Munich, Strategic Landscape Planning and Management, Freising (Germany)

2016-10-15

It is essential to abstract the key information from accounting results of greenhouse gas (GHG) emissions because it can provide a highly generalized and clear picture of GHG emissions, which is especially helpful for the public and policy makers. To clearly display the composition of GHG emissions, the concept of spectrum analysis is introduced and defined in this paper. Next, a multilayer analysis framework for national GHG emissions was proposed, which is represented by a pyramid of three layers: total emissions (first layer), emissions decomposed by gas type or sector (second layer), and emissions decomposed by both gas type and sector (third layer). Based on the analysis results from the first to third layers, the main compositional information of national GHG emissions was gradually summarized and analyzed until a spectrum of GHG emissions was acquired. The spectrum of GHG emissions displays the compositional structure of national GHG emissions in the different layers, which is helpful in identifying priorities for emissions reduction. A case study of Germany's GHG emissions during 1990-2012 was conducted, which indicated that CO{sub 2} and the energy sector were the biggest contributors to the total GHG emissions. Some suggestions for reducing GHG emissions are offered based on the obtained results. And the potential development of spectrum analysis for GHG emissions is also expected from aspects of both research and technology. (orig.)

Millimeter-wave Line Ratios and Sub-beam Volume Density Distributions

Energy Technology Data Exchange (ETDEWEB)

Leroy, Adam K.; Gallagher, Molly [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Usero, Antonio [Observatorio Astronmico Nacional (IGN), C/Alfonso XII, 3, E-28014 Madrid (Spain); Schruba, Andreas [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße 1, D-85748 Garching (Germany); Bigiel, Frank [Institute für theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Kruijssen, J. M. Diederik; Schinnerer, Eva [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12-14, D-69120 Heidelberg (Germany); Kepley, Amanda [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Blanc, Guillermo A. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Bolatto, Alberto D. [Department of Astronomy, Laboratory for Millimeter-wave Astronomy, and Joint Space Institute, University of Maryland, College Park, MD 20742 (United States); Cormier, Diane; Jiménez-Donaire, Maria J. [Max Planck Institute für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Hughes, Annie [CNRS, IRAP, 9 av. du Colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France); Rosolowsky, Erik [Department of Physics, University of Alberta, Edmonton, AB (Canada)

2017-02-01

We explore the use of mm-wave emission line ratios to trace molecular gas density when observations integrate over a wide range of volume densities within a single telescope beam. For observations targeting external galaxies, this case is unavoidable. Using a framework similar to that of Krumholz and Thompson, we model emission for a set of common extragalactic lines from lognormal and power law density distributions. We consider the median density of gas that produces emission and the ability to predict density variations from observed line ratios. We emphasize line ratio variations because these do not require us to know the absolute abundance of our tracers. Patterns of line ratio variations have the potential to illuminate the high-end shape of the density distribution, and to capture changes in the dense gas fraction and median volume density. Our results with and without a high-density power law tail differ appreciably; we highlight better knowledge of the probability density function (PDF) shape as an important area. We also show the implications of sub-beam density distributions for isotopologue studies targeting dense gas tracers. Differential excitation often implies a significant correction to the naive case. We provide tabulated versions of many of our results, which can be used to interpret changes in mm-wave line ratios in terms of adjustments to the underlying density distributions.

Greenhouse gas emissions, energy consumption and economic growth: A panel cointegration analysis from Canadian industrial sector perspective

International Nuclear Information System (INIS)

Hamit-Haggar, Mahamat

2012-01-01

This paper investigates the long-run and the causal relationship between greenhouse gas emissions, energy consumption and economic growth for Canadian industrial sectors over the period 1990–2007. The empirical findings suggest that in the long-run equilibrium, energy consumption has a positive and statistically significant impact on greenhouse gas emissions whereas a non-linear relationship is found between greenhouse gas emissions and economic growth, consistent with the environmental Kuznets curve. The short-run dynamics conveys that there is a unidirectional Granger causality running from energy consumption to greenhouse gas emissions; from economic growth to greenhouse gas emissions and a weak unidirectional causality running from greenhouse gas emissions to energy consumption; from economic growth to energy consumption. In the long-run however, there seems to be a weak one way causality flowing from energy consumption and economic growth to greenhouse gas emissions. - Highlights: ► A long-run and a causal relationship between greenhouse gas emissions, energy consumption and economic growth is investigated. ► Energy consumption has a positive impact on greenhouse gas emissions in the long run. ► Unidirectional causality runs from energy consumption and economic growth to greenhouse gas emissions. ► A weak unidirectional causality runs from greenhouse gas emissions and economic growth to energy consumption.

ICT and greenhouse gas emissions; IKT og klimagassutslipp

Energy Technology Data Exchange (ETDEWEB)

2009-08-15

ICT can go from being a part of the climate challenge to be an important part of the solution by simplify, rationalize and replace a variety of features and services. ICT's contribute through production and operation for approx. 2.5 % of global greenhouse gas emissions. At the same time estimates show that ICT could help to reduce total greenhouse gas emissions by up to 15 % by 2020 through a series of measures. ICT can, for example. contribute to reduce travel activity through remote collaboration, the transition from material to virtual products and by greater energy efficiency in buildings and vehicles. Through remote collaboration, green tender rounds and change of focus from products to services, can authorities reduce their own emissions. In addition, the authorities go ahead as good examples by illustrating how environment benefits from governmental ICT investments. If we assume that video conferencing can replace 1 of 5 flights among the 140 000 state employees, this can lead to a reducted emission of 14 600 tonnes of CO{sub 2} per year. (AG)

Geostatistical modeling of the gas emission zone and its in-place gas content for Pittsburgh-seam mines using sequential Gaussian simulation

Science.gov (United States)

Karacan, C.O.; Olea, R.A.; Goodman, G.

2012-01-01

Determination of the size of the gas emission zone, the locations of gas sources within, and especially the amount of gas retained in those zones is one of the most important steps for designing a successful methane control strategy and an efficient ventilation system in longwall coal mining. The formation of the gas emission zone and the potential amount of gas-in-place (GIP) that might be available for migration into a mine are factors of local geology and rock properties that usually show spatial variability in continuity and may also show geometric anisotropy. Geostatistical methods are used here for modeling and prediction of gas amounts and for assessing their associated uncertainty in gas emission zones of longwall mines for methane control.This study used core data obtained from 276 vertical exploration boreholes drilled from the surface to the bottom of the Pittsburgh coal seam in a mining district in the Northern Appalachian basin. After identifying important coal and non-coal layers for the gas emission zone, univariate statistical and semivariogram analyses were conducted for data from different formations to define the distribution and continuity of various attributes. Sequential simulations performed stochastic assessment of these attributes, such as gas content, strata thickness, and strata displacement. These analyses were followed by calculations of gas-in-place and their uncertainties in the Pittsburgh seam caved zone and fractured zone of longwall mines in this mining district. Grid blanking was used to isolate the volume over the actual panels from the entire modeled district and to calculate gas amounts that were directly related to the emissions in longwall mines.Results indicated that gas-in-place in the Pittsburgh seam, in the caved zone and in the fractured zone, as well as displacements in major rock units, showed spatial correlations that could be modeled and estimated using geostatistical methods. This study showed that GIP volumes may

X-ray emission lines from photoionized plasmas

International Nuclear Information System (INIS)

Liedahl, D.A.

1992-11-01

Plasma emission codes have become a standard tool for the analysis of spectroscopic data from cosmic X-ray sources. However, the assumption of collisional equilibrium, typically invoked in these codes, renders them inapplicable to many important astrophysical situations, particularly those involving X-ray photoionized nebulae, which are likely to exist in the circumsource environments of compact X-ray sources. X-ray line production in a photoionized plasma is primarily the result of radiative cascades following recombination. Through the development of atomic models of several highly-charged ions, this work extends the range of applicability of discrete spectral models to plasmas dominated by recombination. Assuming that ambient plasma conditions lie in the temperature range 10 5 --10 6 K and the density range 10 11 --10 16 cm -3 , X-ray line spectra are calculated over the wavelength range 5--45 angstrom using the HULLAC atomic physics package. Most of the work focuses on the Fe L-shell ions. Line ratios of the form (3s-2p)/(3d-2p) are shown to characterize the principal mode of line excitation, thereby providing a simple signature of photoionization. At electron densities exceeding 10 12 cm -3 , metastable state populations in the ground configurations approach their LTE value, resulting in the enrichment of the Fe L-shell recombination spectrum and a set of density-sensitive X-ray line ratios. Radiative recombination continua and emission lines produced selectively by Δn = 0 dielectronic recombination are shown to provide two classes of temperature diagnostics. Because of the extreme overionization, the recombination continua are expected to be narrow (ΔE/E much-lt 1), with ΔE = kT. Dielectronic recombination selectively drives radiative transitions that originate on states with vacancies in the 2s subshell, states that are inaccessible under pure RR population kinetics

Methane emission from naturally ventilated livestock buildings can be determined from gas concentration measurements

DEFF Research Database (Denmark)

Bjerg, B; Zhang, Guoqiang; Madsen, J

2012-01-01

Determination of emission of contaminant gases as ammonia, methane, or laughing gas from natural ventilated livestock buildings with large opening is a challenge due to the large variations in gas concentration and air velocity in the openings. The close relation between calculated animal heat pr...... to investigate the influence of feed composition on methane emission in a relative large number of operating cattle buildings and consequently it can support a development towards reduced greenhouse gas emission from cattle production.......Determination of emission of contaminant gases as ammonia, methane, or laughing gas from natural ventilated livestock buildings with large opening is a challenge due to the large variations in gas concentration and air velocity in the openings. The close relation between calculated animal heat...... ventilated, 150 milking cow building. The results showed that the methane emission can be determined with much higher precision than ammonia or laughing gas emissions, and, for methane, relatively precise estimations can be based on measure periods as short as 3 h. This result makes it feasible...

The importance of addressing methane emissions as part of a comprehensive greenhouse gas management strategy

Energy Technology Data Exchange (ETDEWEB)

Bylin, Carey [U.S. Environmental Protection Agency (EPA), Washington, DC (United States); Robinson, Donald; Cacho, Mariella; Russo, Ignacio; Stricklin, Eric [ICF International, Fairfax, VA (United States); Rortveit, Geir Johan [Statoil, Stavanger (Norway); Chakraborty, A.B. [Oil and Natural Gas Corporation Ltda. (ONGC), Dehradun (India); Pontiff, Mike [Newfield, The Woodlands, TX, (United States); Smith, Reid [British Petroleum (BP), London (United Kingdom)

2012-07-01

Given the climate forcing properties of greenhouse gases (GHGs) and the current state of the global economy, it is imperative to mitigate emissions of GHGs cost-effectively. Typically, CO{sub 2} is the main focus of most companies' and governments' GHG emissions reductions strategies. However, when considering near-term goals, it becomes clear that emissions reductions of other GHGs must be pursued. One such GHG is methane, the primary component of natural gas. Reducing GHG emissions and generating profits are not necessarily a mutually exclusive endeavor as illustrated by the United States Environmental Protection Agency's (EPA) Natural Gas STAR Program. The Program is a worldwide voluntary, flexible partnership of oil and gas companies which promotes cost-effective technologies and practices to reduce methane emissions from oil and natural gas operations. In an effort to meet environmental goals without sacrificing profitability, Natural Gas STAR partner companies have identified over 60 cost-effective best practices to reduce their methane emissions, which they report to the EPA. This paper discusses: 1) the importance of reducing methane emissions and its economic impact, 2) a comparison of methane emission reduction projects relative to other greenhouse gas reduction projects in the oil and gas industry, 3) the value of source-specific methane emissions inventories, and 4) methane emission reduction opportunities from hydraulically fractured gas well completions and centrifugal compressor wet seals. From the analyses and examples in this paper, it can be concluded that methane emission reduction projects can be readily identified, profitable, and effective in mitigating global climate change. (author)

Broad-line high-excitation gas in the elliptical galaxy NGC5128

International Nuclear Information System (INIS)

Phillips, M.M.; Taylor, K.; Axon, D.J.; Atherton, P.D.; Hook, R.N.

1984-01-01

A faint, but extensive component of broad-line ionized gas has been discovered in the peculiar giant elliptical galaxy NGC5128. This component has a radically different spatial distribution from the well-studied rotating photoionized gas associated with the dust lane although the velocity fields of the two components are similar. The origin of the broad-line gas is considered as its possible relation to the active nucleus and the X-ray jet discussed. (author)

Dark matter line emission constraints from NuSTAR observations of the Bullet Cluster

DEFF Research Database (Denmark)

Riemer-Sørensen, S.; Wik, D.; Madejski, G.

2015-01-01

Some dark matter candidates, e.g., sterile neutrinos, provide observable signatures in the form of mono-energetic line emission. We present the first search for dark matter line emission in the range in a pointed observation of the Bullet Cluster with NuSTAR. We do not detect any significant line...... emission and instead we derive upper limits (95% CL) on the flux, and interpret these constraints in the context of sterile neutrinos and more generic dark matter candidates. NuSTAR does not have the sensitivity to constrain the recently claimed line detection at , but improves on the constraints...... for energies of 10–25 keV....

Measurement of the deuterium Balmer series line emission on EAST

Energy Technology Data Exchange (ETDEWEB)

Wu, C. R.; Xu, Z.; Jin, Z.; Zhang, P. F. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui 230031 (China); Huang, J., E-mail: juan.huang@ipp.ac.cn; Gao, W.; Gao, W.; Chang, J. F.; Xu, J. C.; Duan, Y. M.; Chen, Y. J.; Zhang, L.; Wu, Z. W.; Li, J. G. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); Hou, Y. M. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2016-11-15

Volume recombination plays an important role towards plasma detachment for magnetically confined fusion devices. High quantum number states of the Balmer series of deuterium are used to study recombination. On EAST (Experimental Advanced Superconducting Tokamak), two visible spectroscopic measurements are applied for the upper/lower divertor with 13 channels, respectively. Both systems are coupled with Princeton Instruments ProEM EMCCD 1024B camera: one is equipped on an Acton SP2750 spectrometer, which has a high spectral resolution ∼0.0049 nm with 2400 gr/mm grating to measure the D{sub α}(H{sub α}) spectral line and with 1200 gr/mm grating to measure deuterium molecular Fulcher band emissions and another is equipped on IsoPlane SCT320 using 600 gr/mm to measure high-n Balmer series emission lines, allowing us to study volume recombination on EAST and to obtain the related line averaged plasma parameters (T{sub e}, n{sub e}) during EAST detached phases. This paper will present the details of the measurements and the characteristics of deuterium Balmer series line emissions during density ramp-up L-mode USN plasma on EAST.

Spectrophotometry of emission-line stars in the magellanic clouds

Science.gov (United States)

Bohannan, Bruce

1990-01-01

The strong emission lines in the most luminous stars in the Magellanic Clouds indicate that these stars have such strong stellar winds that their photospheres are so masked that optical absorption lines do not provide an accurate measure of photospheric conditions. In the research funded by this grant, temperatures and gravities of emission-line stars both in the Large (LMC) and Small Magellanic Clouds (SMC) have been measured by fitting of continuum ultraviolet-optical fluxes observed with IUE with theoretical model atmospheres. Preliminary results from this work formed a major part of an invited review 'The Distribution of Types of Luminous Blue Variables'. Interpretation of the IUE observations obtained in this grant and archive data were also included in a talk at the First Boulder-Munich Hot Stars Workshop. Final results of these studies are now being completed for publication in refereed journals.

Spin Start Line Effects on the J2X Gas Generator Chamber Acoustics

Science.gov (United States)

Kenny, R. Jeremy

2011-01-01

The J2X Gas Generator engine design has a spin start line connected near to the turbine inlet vanes. This line provides helium during engine startup to begin turbomachinery operation. The spin start line also acts as an acoustic side branch which alters the chamber's acoustic modes. The side branch effectively creates 'split modes' in the chamber longitudinal modes, in particular below the first longitudinal mode and within the frequency range associated with the injection-coupled response of the Gas Generator. Interaction between the spin start-modified chamber acoustics and the injection-driven response can create a higher system response than without the spin start attached to the chamber. This work reviews the acoustic effects of the spin start line as seen throughout the workhorse gas generator test program. A simple impedance model of the spin start line is reviewed. Tests were run with no initial spin start gas existing in the line, as well as being initially filled with nitrogen gas. Tests were also run with varying spin start line lengths from 0" to 40". Acoustic impedance changes due to different spin start gas constituents and line lengths are shown. Collected thermocouple and static pressure data in the spin start line was used to help estimate the fluid properties along the line length. The side branch impedance model was coupled to a chamber impedance model to show the effects on the overall chamber response. Predictions of the spin start acoustic behavior for helium operation are shown and compared against available data.

Inferring physical properties of galaxies from their emission-line spectra

Science.gov (United States)

Ucci, G.; Ferrara, A.; Gallerani, S.; Pallottini, A.

2017-02-01

We present a new approach based on Supervised Machine Learning algorithms to infer key physical properties of galaxies (density, metallicity, column density and ionization parameter) from their emission-line spectra. We introduce a numerical code (called GAME, GAlaxy Machine learning for Emission lines) implementing this method and test it extensively. GAME delivers excellent predictive performances, especially for estimates of metallicity and column densities. We compare GAME with the most widely used diagnostics (e.g. R23, [N II] λ6584/Hα indicators) showing that it provides much better accuracy and wider applicability range. GAME is particularly suitable for use in combination with Integral Field Unit spectroscopy, both for rest-frame optical/UV nebular lines and far-infrared/sub-millimeter lines arising from photodissociation regions. Finally, GAME can also be applied to the analysis of synthetic galaxy maps built from numerical simulations.

Advanced gas-emission anode design for microfluidic fuel cell eliminating bubble accumulation

International Nuclear Information System (INIS)

Zhang, Hao; Xuan, Jin; Wang, Huizhi; Leung, Dennis Y C; Xu, Hong; Zhang, Li

2017-01-01

A microfluidic fuel cell is a low cost, easily fabricated energy device and is considered a promising energy supplier for portable electronics. However, the currently developed microfluidic fuel cells that are fed with hydrocarbon fuels are confronted with a bubble problem especially when operating at high current density conditions. In this work, a gas-emission anode is presented to eliminate the gas accumulation at the anode. This gas-emission anode is verified as a valid design for discharging gaseous products, which is especially beneficial for stable operation of microfluidic fuel cells. The electrochemical performance of a counter-flow microfluidic fuel cell equipped with a gas-emission anode was measured. The results indicate that the specific design of the gas-emission anode is essential for reducing the oxygen reduction reaction parasitic effect at the anode. Fuel utilization of 76.4% was achieved at a flow rate of 0.35 µ l min −1 . Current–voltage curves of single electrodes were measured and the parasitic effect at the anode was identified as the main performance limiting factor in the presented anode design. (paper)

Evaluation of greenhouse gas emission risks from storage of wood residue

International Nuclear Information System (INIS)

Wihersaari, Margareta

2005-01-01

The use of renewable energy sources instead of fossil fuels is one of the most important means of limiting greenhouse gas emissions in the near future. In Finland, wood energy is considered to be a very important potential energy source in this sense. There might, however, still be some elements of uncertainty when evaluating biofuel production chains. By combining data from a stack of composting biodegradable materials and forest residue storage research there was an indication that rather great amounts of greenhouse gases maybe released during storage of wood chip, especially if there is rapid decomposition. Unfortunately, there have not been many evaluations of greenhouse gas emissions of biomass handling and storage heaps. The greenhouse gas emissions are probably methane, when the temperature in the fuel stack is above the ambient temperature, and nitrous oxide, when the temperature is falling and the decaying process is slowing down. Nowadays it is still rather unusual to store logging residue as chips, because the production is small, but in Finland storage of bark and other by-products from the forest industry is a normal process. The evaluations made indicate that greenhouse gas emissions from storage can, in some cases, be much greater than emissions from the rest of the biofuel production and transportation chain

Spatially Resolved HST Grism Spectroscopy of a Lensed Emission Line Galaxy at z ~ 1

Science.gov (United States)

Frye, Brenda L.; Hurley, Mairead; Bowen, David V.; Meurer, Gerhardt; Sharon, Keren; Straughn, Amber; Coe, Dan; Broadhurst, Tom; Guhathakurta, Puragra

2012-07-01

We take advantage of gravitational lensing amplification by A1689 (z = 0.187) to undertake the first space-based census of emission line galaxies (ELGs) in the field of a massive lensing cluster. Forty-three ELGs are identified to a flux of i 775 = 27.3 via slitless grism spectroscopy. One ELG (at z = 0.7895) is very bright owing to lensing magnification by a factor of ≈4.5. Several Balmer emission lines (ELs) detected from ground-based follow-up spectroscopy signal the onset of a major starburst for this low-mass galaxy (M * ≈ 2 × 109 M ⊙) with a high specific star formation rate (≈20 Gyr-1). From the blue ELs we measure a gas-phase oxygen abundance consistent with solar (12+log(O/H) = 8.8 ± 0.2). We break the continuous line-emitting region of this giant arc into seven ~1 kpc bins (intrinsic size) and measure a variety of metallicity-dependent line ratios. A weak trend of increasing metal fraction is seen toward the dynamical center of the galaxy. Interestingly, the metal line ratios in a region offset from the center by ~1 kpc have a placement on the blue H II region excitation diagram with f ([O III])/f (Hβ) and f ([Ne III])/f (Hβ) that can be fitted by an active galactic nucleus (AGN). This asymmetrical AGN-like behavior is interpreted as a product of shocks in the direction of the galaxy's extended tail, possibly instigated by a recent galaxy interaction. Based, in part, on data obtained with the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

Assessing the difference. Greenhouse gas emissions of electricity generation chains

International Nuclear Information System (INIS)

Spadaro, J.V.; Langlois, L.; Hamilton, B.

2000-01-01

Greenhouse gases have to the potential to influence global climate change by interfering with the natural process of heat exchange between the earth's atmosphere and outer space. Reducing atmospheric GHG concentrations have become an international priority as evidenced by the signing of the Kyoto Protocol, which would reduce emissions from industrialized countries (Annex 1) by about 5% below 1990 levels during the commitment period 2008-12. There are a number of technical options that could be implemented in order to achieve the proposed reduction target. As for emissions related to electricity generation, perhaps the most important factor over the near term is the improvement in efficiency of using energy at all the stages of the fuel cycle, including fuel preparation and transportation, fuel-to-electricity conversion at the power plant and at the point of end-use (which has not been considered here). Strategies for reducing methane releases during fuel mining and during gas transmission are very relevant. Switching to less carbon intensive or low carbon fuels, such as gas, nuclear power and renewables, will play a major role in reducing emissions. These changes are technically feasible using present day knowledge and experience, require minimal changes in consumer lifestyle, and represent reasonable capital turnover (gas and nuclear for baseload generation and renewables in niche markets or for peak load applications). This article has presented information on GHG emission factors for different fuels using a Full Energy Chain approach, which attempts to quantify the environmental emissions from all stages of electricity generation, i.e. 'cradle-to-grave'. Fossil-fueled technologies have the highest emission factors, with coal typically twice as high as natural gas. Considering the large variations in fuel- to-electricity conversion technology, it can be said that GHG emission factors can be an order of magnitude higher than current solar PV systems and up to two

Greenhouse gas emissions from the energy sector

International Nuclear Information System (INIS)

Mbuthi, P.N.

1998-01-01

This study quantifies greenhouse gas emissions from Kenya's energy activities. It is organised in four major sections, namely, an overview of the energy sector; data sources and methodology of analysis; results and recommendations for future climate change mitigation

Greenhouse gas emissions from South Africa

CSIR Research Space (South Africa)

Scholes, RJ

1996-05-01

Full Text Available of CO2. These gases included 350 Tg CO2 (65.6% of the effect), 183 Tg CH4 (34.2%) and 1.2 Tg N2O (0.2%). The mining and burning of coal contributed more than 80% of the greenhouse gas emissions from South African territory....

Detecting gas leaks by ultrasonic emission

DEFF Research Database (Denmark)

Rasmussen, Karsten Bo; Henriksen, Eigil

1997-01-01

The emission of noise in the frequency range 10 kHz to 25.6 kHz from an experimental gas leak in a flanged joint has been experimentally investigated. The overall conclusion is that the emitted noise is almost frequency independent in level within the considered frequency range.A small PC program...

An ALMA Survey of CO Isotopologue Emission from Protoplanetary Disks in Chamaeleon I

Energy Technology Data Exchange (ETDEWEB)

Long Feng; Herczeg, Gregory J. [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Haidian Qu, 100871 Beijing (China); Pascucci, Ilaria; Apai, Daniel; Hendler, Nathan; Mulders, Gijs D. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Drabek-Maunder, Emily; Mohanty, Subhanjoy [Imperial College London, London SW7 2AZ (United Kingdom); Testi, Leonardo [ESO/European Southern Observatory, Garching bei München (Germany); Henning, Thomas [Max Planck Institute for Astronomy, Heidelberg (Germany); Manara, Carlo F., E-mail: longfeng@pku.edu.cn [Scientific Support Office, Directorate of Science, European Space Research and Technology Centre (ESA/ESTEC), Noordwijk (Netherlands)

2017-08-01

The mass of a protoplanetary disk limits the formation and future growth of any planet. Masses of protoplanetary disks are usually calculated from measurements of the dust continuum emission by assuming an interstellar gas-to-dust ratio. To investigate the utility of CO as an alternate probe of disk mass, we use ALMA to survey {sup 13}CO and C{sup 18}O J = 3–2 line emission from a sample of 93 protoplanetary disks around stars and brown dwarfs with masses from in the nearby Chamaeleon I star-forming region. We detect {sup 13}CO emission from 17 sources and C{sup 18}O from only one source. Gas masses for disks are then estimated by comparing the CO line luminosities to results from published disk models that include CO freeze-out and isotope-selective photodissociation. Under the assumption of a typical interstellar medium CO-to-H{sub 2} ratio of 10{sup −4}, the resulting gas masses are implausibly low, with an average gas mass of ∼0.05 M {sub Jup} as inferred from the average flux of stacked {sup 13}CO lines. The low gas masses and gas-to-dust ratios for Cha I disks are both consistent with similar results from disks in the Lupus star-forming region. The faint CO line emission may instead be explained if disks have much higher gas masses, but freeze-out of CO or complex C-bearing molecules is underestimated in disk models. The conversion of CO flux to CO gas mass also suffers from uncertainties in disk structures, which could affect gas temperatures. CO emission lines will only be a good tracer of the disk mass when models for C and CO depletion are confirmed to be accurate.

Reducing the Green House Gas Emissions from the Transportation Sector

Directory of Open Access Journals (Sweden)

Oyewande Akinnikawe

2010-02-01

Full Text Available In the United States, two thirds of the carbon monoxide and about one third of carbon dioxide emissions come from the transportation sector. Ways to reduce these emissions in the future include replacing gasoline and diesel by biofuels, or by blend of biofuels with conventional gasoline and diesel, or by compressed natural gas (CNG, or by replacing internal combustion engines by electric motors powered by hydrogen fuel cells or battery-powered electric vehicles recharged from the electric grid. This presentation will review these technologies the fuel production pathways, when they are likely to be available, and by what fraction transportation sector green house gas emissions could be reduced by each. A well-to-wheels (WTW analysis is performed on each vehicle/ fuel technology using the GREET model and the total energy use, the CO 2 emissions, NO x emissions, SO x emissions for the life cycle of the vehicle technologies are calculated. Prospects for reducing foreign oil dependence as well as mitigating green house gases emission from the transportation sector will be considered in the analysis.

Reducing greenhouse gas emissions and improving air quality: Two global challenges.

Science.gov (United States)

Erickson, Larry E

2017-07-01

There are many good reasons to promote sustainable development and reduce greenhouse gas emissions and other combustion emissions. The air quality in many urban environments is causing many premature deaths because of asthma, cardiovascular disease, chronic obstructive pulmonary disease, lung cancer, and dementia associated with combustion emissions. The global social cost of air pollution is at least $3 trillion/year; particulates, nitrogen oxides and ozone associated with combustion emissions are very costly pollutants. Better air quality in urban environments is one of the reasons for countries to work together to reduce greenhouse gas emissions through the Paris Agreement on Climate Change. There are many potential benefits associated with limiting climate change. In the recent past, the concentrations of greenhouse gases in the atmosphere have been increasing and the number of weather and climate disasters with costs over $1 billion has been increasing. The average global temperature set new record highs in 2014, 2015, and 2016. To reduce greenhouse gas emissions, the transition to electric vehicles and electricity generation using renewable energy must take place in accord with the goals of the Paris Agreement on Climate Change. This work reviews progress and identifies some of the health benefits associated with reducing combustion emissions. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 982-988, 2017.

The Origins of [C ii] Emission in Local Star-forming Galaxies

Energy Technology Data Exchange (ETDEWEB)

Croxall, K. V. [Department of Astronomy, The Ohio State University, 4051 McPherson Laboratory, 140 W. 18th Avenue, Columbus, OH, 43210 (United States); Smith, J. D. [Max-Planck-Institut fur Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Pellegrini, E. [Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606 (United States); Groves, B. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Bolatto, A.; Wolfire, M. G. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Herrera-Camus, R. [Max-Planck-Institut für extraterrestrische Physik, Giessen-bachstr., D-85748 Garching (Germany); Sandstrom, K. M. [Center for Astrophysics and Space Sciences, Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Draine, B. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Armus, L. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Boquien, M. [Unidad de Astronomía, Fac. Cs. Básicas, Universidad de Antofagasta, Avda. U. de Antofagasta 02800, Antofagasta (Chile); Brandl, B. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Dale, D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Galametz, M. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu—CNRS—Université Paris Diderot, CEA-Saclay, 91191, Gif-sur-Yvette (France); Hunt, L., E-mail: jd.smith@utoledo.edu [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze (Italy); and others

2017-08-20

The [C ii] 158 μ m fine-structure line is the brightest emission line observed in local star-forming galaxies. As a major coolant of the gas-phase interstellar medium, [C ii] balances the heating, including that due to far-ultraviolet photons, which heat the gas via the photoelectric effect. However, the origin of [C ii] emission remains unclear because C{sup +} can be found in multiple phases of the interstellar medium. Here we measure the fractions of [C ii] emission originating in the ionized and neutral gas phases of a sample of nearby galaxies. We use the [N ii] 205 μ m fine-structure line to trace the ionized medium, thereby eliminating the strong density dependence that exists in the ratio of [C ii]/[N ii] 122 μ m. Using the FIR [C ii] and [N ii] emission detected by the KINGFISH (Key Insights on Nearby Galaxies: a Far- Infrared Survey with Herschel ) and Beyond the Peak Herschel programs, we show that 60%–80% of [C ii] emission originates from neutral gas. We find that the fraction of [C ii] originating in the neutral medium has a weak dependence on dust temperature and the surface density of star formation, and has a stronger dependence on the gas-phase metallicity. In metal-rich environments, the relatively cooler ionized gas makes substantially larger contributions to total [C ii] emission than at low abundance, contrary to prior expectations. Approximate calibrations of this metallicity trend are provided.

Research on forecast technology of mine gas emission based on fuzzy data mining (FDM)

Energy Technology Data Exchange (ETDEWEB)

Xu Chang-kai; Wang Yao-cai; Wang Jun-wei [CUMT, Xuzhou (China). School of Information and Electrical Engineering

2004-07-01

The safe production of coalmine can be further improved by forecasting the quantity of gas emission based on the real-time data and historical data which the gas monitoring system has saved. By making use of the advantages of data warehouse and data mining technology for processing large quantity of redundancy data, the method and its application of forecasting mine gas emission quantity based on FDM were studied. The constructing fuzzy resembling relation and clustering analysis were proposed, which the potential relationship inside the gas emission data may be found. The mode finds model and forecast model were presented, and the detailed approach to realize this forecast was also proposed, which have been applied to forecast the gas emission quantity efficiently.

Total greenhouse gas emissions related to the Dutch crop production system

NARCIS (Netherlands)

Kramer, K.J.; Moll, H.C.; Nonhebel, S.

1999-01-01

This article discusses the greenhouse gas emissions (CO2, CH4, N2O) related to Dutch agricultural crop production. Emissions occur during agricultural processes (direct emissions) as well as in the life cycle of the required inputs (indirect emissions). An integrated approach assesses the total

EMISSION LINES BETWEEN 1 AND 2 keV IN COMETARY X-RAY SPECTRA

Energy Technology Data Exchange (ETDEWEB)

Ewing, Ian; Christian, Damian J. [Department of Physics and Astronomy, California State University, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Bodewits, Dennis [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Dennerl, Konrad [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, D-85741 Garching Germany (Germany); Lisse, Carey M. [Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 (United States); Wolk, Scott J., E-mail: ian.ewing.794@my.csun.edu, E-mail: daman.christian@csun.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-01-20

We present the detection of new cometary X-ray emission lines in the 1.0-2.0 keV range using a sample of comets observed with the Chandra X-Ray Observatory and ACIS spectrometer. We have selected five comets from the Chandra sample with good signal-to-noise spectra. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), and C/2008 8P (Tuttle). We modeled the spectra with an extended version of our solar wind charge exchange (SWCX) emission model. Above 1 keV, we find Ikeya-Zhang to have strong emission lines at 1340 and 1850 eV which we identify as being created by SWCX lines of Mg XI and Si XIII, respectively, and weaker emission lines at 1470, 1600, and 1950 eV formed by SWCX of Mg XII, Mg XI, and Si XIV, respectively. The Mg XI and XII and Si XIII and XIV lines are detected at a significant level for the other comets in our sample (LS4, MH, Encke, 8P), and these lines promise additional diagnostics to be included in SWCX models. The silicon lines in the 1700-2000 eV range are detected for all comets, but with the rising background and decreasing cometary emission, we caution that these detections need further confirmation with higher resolution instruments.

Limiting net greenhouse gas emissions in the United States

Energy Technology Data Exchange (ETDEWEB)

Bradley, R A; Watts, E C; Williams, E R [eds.

1991-09-01

In 2988 the Congress requested DOE produce a study on carbon dioxide inventory and policy to provide an inventory of emissions sources and to analyze policies to achieve a 20% reduction in carbon dioxide emissions in 5 to 10 years and a 50% reduction in 15 to 20 years. This report presents the results of that study. Energy and environmental technology data were analyzed using computational analysis models. This information was then evaluated, drawing on current scientific understanding of global climate change, the possible consequences of anthropogenic climate change (change caused by human activity), and the relationship between energy production and use and the emission of radiactively important gases. Topics discussed include: energy and environmental technology to reduce greenhouse gas emissions, fossil energy production and electricity generation technologies, nuclear energy technology, renewable energy technologies, energy storage, transmission, and distribution technology, transportation, technology, industrial technology, residential and commercial building technology, greenhouse gas removal technology, approaches to restructuring the demand for energy.

Effects of natural gas composition on performance and regulated, greenhouse gas and particulate emissions in spark-ignition engines

International Nuclear Information System (INIS)

Amirante, R.; Distaso, E.; Di Iorio, S.; Sementa, P.; Tamburrano, P.; Vaglieco, B.M.; Reitz, R.D.

2017-01-01

Highlights: • The influence of natural gas composition is investigated. • Real-time methane/propane fuel mixtures were realized. • IMEP, HRR and MBF were used to evaluate the effects on engine performance. • Gaseous, greenhouse and Particulate emissions were studied. • The propane content strongly influenced performance and emissions. - Abstract: In vehicles fueled with compressed natural gas, a variation in the fuel composition can have non-negligible effects on their performance, as well as on their emissions. The present work aimed to provide more insight on this crucial aspect by performing experiments on a single-cylinder port-fuel injected spark-ignition engine. In particular, methane/propane mixtures were realized to isolate the effects of a variation of the main constituents in natural gas on engine performance and associated pollutant emissions. The propane volume fraction was varied from 10 to 40%. Using an experimental procedure designed and validated to obtain precise real-time mixture fractions to inject directly into the intake manifold. Indicative Mean Effective Pressure, Heat Release Rate and Mass Burned Fraction were used to evaluate the effects on engine performance. Gaseous emissions were measured as well. Particulate Mass, Number and Size Distributions were analyzed with the aim to identify possible correlations existing between fuel composition and soot emissions. Emissions samples were taken from the exhaust flow, just downstream of the valves. Opacity was measured downstream the Three-Way Catalyst. Three different engine speeds were investigated, namely 2000, 3000 and 4000 rpm. Stoichiometric and full load conditions were considered in all tests. The results were compared with pure methane and propane, as well as with natural gas. The results indicated that both performance and emissions were strongly influenced by the variation of the propane content. Increasing the propane fraction favored more complete combustion and increased NO

Implications of greenhouse gas emission mitigation scenarios for the main Asian regions

NARCIS (Netherlands)

van Ruijven, B.J.|info:eu-repo/dai/nl/304834521; van Vuuren, D.P.|info:eu-repo/dai/nl/11522016X; van Vliet, J.; Mendoza Beltran, A.; Deetman, S.; den Elzen, M.G.J.

2012-01-01

In order to limit global mean temperature increase, long-term greenhouse gas emissions need to be reduced. This paper discusses the implications of greenhouse gas emission reductions for major Asian regions (China, India, Indonesia, South-East Asia, Japan and Korea) based on results from the IMAGE

Bridging greenhouse gas emissions and renewable energy deployment target: Comparative assessment of China and India

International Nuclear Information System (INIS)

Mittal, Shivika; Dai, Hancheng; Fujimori, Shinichiro; Masui, Toshihiko

2016-01-01

Highlights: • India and China’s latest renewable energy targets toward 2030 are assessed. • Carbon emission cap is in line with 2-degree target and governmental commitment. • The impacts of renewable energy on emissions and mitigation costs are quantified. - Abstract: Renewable energy has a critical role in limiting the greenhouse gas (GHG) emissions. This paper assesses the implication of aligning renewable energy deployment target with national emission reduction target for mitigation cost. The assessment methodology uses Asia-Pacific Integrated Assessment/computable general equilibrium (AIM/CGE) model to determine the mitigation cost in terms of GDP and welfare loss under alternative renewable targets in different climate-constrained scenarios. A range of country-specific emission constraints is taken to address the uncertainties related to global emission pathway and emission entitlement scheme. Comparative results show that China needs to increase its share of non-fossil fuel significantly in the primary energy mix to achieve the stringent emission reduction target compared to India. The mitigation cost in terms of economic and welfare loss can be reduced by increasing the penetration of the renewable energy to achieve the same emission reduction target. The modeling results show that coordinated national climate and renewable energy policies help to achieve the GHG emission reduction target in an efficient and cost-effective manner.

Observations of far-infrared molecular emission lines from the Orion molecular cloud

International Nuclear Information System (INIS)

Viscuso, P.J.

1986-01-01

The Orion Nebula has been the subject of intensive study for over one hundred years. Far-infrared (FIR) molecular line observations of CO in the shock region surrounding the infrared source IRc2 have suggested that the molecular hydrogen density in the shocked and post-shock gas is roughly 3 x 10 6 cm -3 . The temperature of this gas is on the order of 750-2000K. IRc2, like other nearby infrared sources within the Nebula, is thought to be a site of recent star formation. This object is apparently at the center of a massive bipolar molecular outflow of gas, which is producing a shock front where it meets the ambient molecular cloud surrounding IRc2. Study of such regions is important for the understanding of the chemical and physical processes that are involved in the formation of stars from molecular clouds. Recently, several far-infrared transitions among the low-lying levels of OH have been observed toward IRc2. OH is thought to be abundant, and it plays an important role in the chemical evolution of the shock and post-shock regions. The OH emission serves as a sensitive probe of the temperature and density for the shock-processed gas. A rigorous treatment of the radiative transfer of these measured transitions is performed using the escape probability formalism. From this analysis, the author determines the temperature of the OH-emitting region to be on the order of 40K. This suggests that the gas is part of the post-shock gas that has cooled sufficiently, most likely by way of radiative cooling by CO

Life Cycle Assessment of Greenhouse Gas Emissions

NARCIS (Netherlands)

Reijnders, L.; Chen, W.Y.; Suzuki, T.; Lackner, M.

2015-01-01

Life cycle assessments of greenhouse gas emissions have been developed for analyzing products "from cradle to grave": from resource extraction to waste disposal. Life cycle assessment methodology has also been applied to economies, trade between countries, aspects of production, and waste

Fugitive emission inventory from Brazilian oil and gas industry (2000-2005) and discussion of mitigation measures

Energy Technology Data Exchange (ETDEWEB)

Carloni, Flavia A.; D' Avignon, Alexandre; La Rovere, Emilio L. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Centro Clima

2008-07-01

The objective of this work is to evaluate current emissions of GHGs within the Brazilian oil and gas industry, specifically the fugitive emissions arising from exploration and production. Besides, projects for mitigating these emissions and opportunities for the national industry are investigated. Results show that N{sub 2}O contributes little to fugitive emissions from the oil and gas industry, principally from gas sector. NMVOC emissions are significant, principally from the oil sector. In relation to CO{sub 2} and CH{sub 4} emissions, the oil sector emits more CO{sub 2} while the gas sector contributes more to CH{sub 4} emissions. In both sectors flaring is the activity that emits most CO{sub 2}. In relation to CH{sub 4} the principal contribution to emissions are from exploration and production onshore, although offshore activities as a whole play a greater part in the national industry. The results make it clear that the use of gas from flaring activity is a great opportunity for emission mitigation projects. From a business point of view, methane emissions could mean lost opportunities in selling natural gas. The Kyoto Protocol mechanisms, as the Clean Development Mechanism and Joint Implementation actions, provide the opportunity to stimulate investments in projects for reducing flaring and venting of associated gas. (author)

Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

Science.gov (United States)

Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

2008-11-25

A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

Energy Technology Data Exchange (ETDEWEB)

Neilsen, Joseph [Department of Astronomy, Boston University, Boston, MA 02215 (United States); Coriat, Mickaël [Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Fender, Rob; Broderick, Jess W. [Department of Physics, Oxford University, Oxford OX1 3RH (United Kingdom); Lee, Julia C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Ponti, Gabriele [Max Planck Institute fur Extraterrestriche Physik, D-85748 Garching (Germany); Tzioumis, Anastasios K.; Edwards, Philip G., E-mail: neilsenj@bu.edu [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia)

2014-03-20

Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission.

A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

International Nuclear Information System (INIS)

Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Broderick, Jess W.; Lee, Julia C.; Ponti, Gabriele; Tzioumis, Anastasios K.; Edwards, Philip G.

2014-01-01

Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission

Reducing greenhouse gas emissions from the Ontario automotive sector

International Nuclear Information System (INIS)

Anon.

1995-11-01

A variety of options to reduce greenhouse gas emissions from the automotive sector in Ontario over the next decade were discussed. Each option was assessed in terms of practicality and implications for implementation. I was concluded that improvements in fuel economy anticipated from advancing technology, with or without new mandated standards, will not be enough to offset the impact of growth in vehicle fleet size and kilometres driven. If the goal is to stabilize greenhouse gas emissions, other measures such as reducing the fleet size and vehicle kilometres travelled and accelerated vehicle retirement (scrappage) programs must be considered. Key constraints on expansion of the alternative fuel fleet were identified. These include: (1) limited availability of an adequate range of alternative fuel vehicles at competitive prices, (2) limited refuelling facility infrastructure in the case of natural gas, limited range and fuel storage capacity for natural gas; (3)current limited fuel ethanol production capacity, and (4) market perceptions of performance, reliability and safety. tabs

Multi-objective optimisation of wastewater treatment plant control to reduce greenhouse gas emissions.

Science.gov (United States)

Sweetapple, Christine; Fu, Guangtao; Butler, David

2014-05-15

This study investigates the potential of control strategy optimisation for the reduction of operational greenhouse gas emissions from wastewater treatment in a cost-effective manner, and demonstrates that significant improvements can be realised. A multi-objective evolutionary algorithm, NSGA-II, is used to derive sets of Pareto optimal operational and control parameter values for an activated sludge wastewater treatment plant, with objectives including minimisation of greenhouse gas emissions, operational costs and effluent pollutant concentrations, subject to legislative compliance. Different problem formulations are explored, to identify the most effective approach to emissions reduction, and the sets of optimal solutions enable identification of trade-offs between conflicting objectives. It is found that multi-objective optimisation can facilitate a significant reduction in greenhouse gas emissions without the need for plant redesign or modification of the control strategy layout, but there are trade-offs to consider: most importantly, if operational costs are not to be increased, reduction of greenhouse gas emissions is likely to incur an increase in effluent ammonia and total nitrogen concentrations. Design of control strategies for a high effluent quality and low costs alone is likely to result in an inadvertent increase in greenhouse gas emissions, so it is of key importance that effects on emissions are considered in control strategy development and optimisation. Copyright © 2014 Elsevier Ltd. All rights reserved.

High-global warming potential F-gas emissions in California: comparison of ambient-based versus inventory-based emission estimates, and implications of refined estimates.

Science.gov (United States)

Gallagher, Glenn; Zhan, Tao; Hsu, Ying-Kuang; Gupta, Pamela; Pederson, James; Croes, Bart; Blake, Donald R; Barletta, Barbara; Meinardi, Simone; Ashford, Paul; Vetter, Arnie; Saba, Sabine; Slim, Rayan; Palandre, Lionel; Clodic, Denis; Mathis, Pamela; Wagner, Mark; Forgie, Julia; Dwyer, Harry; Wolf, Katy

2014-01-21

To provide information for greenhouse gas reduction policies, the California Air Resources Board (CARB) inventories annual emissions of high-global-warming potential (GWP) fluorinated gases, the fastest growing sector of greenhouse gas (GHG) emissions globally. Baseline 2008 F-gas emissions estimates for selected chlorofluorocarbons (CFC-12), hydrochlorofluorocarbons (HCFC-22), and hydrofluorocarbons (HFC-134a) made with an inventory-based methodology were compared to emissions estimates made by ambient-based measurements. Significant discrepancies were found, with the inventory-based emissions methodology resulting in a systematic 42% under-estimation of CFC-12 emissions from older refrigeration equipment and older vehicles, and a systematic 114% overestimation of emissions for HFC-134a, a refrigerant substitute for phased-out CFCs. Initial, inventory-based estimates for all F-gas emissions had assumed that equipment is no longer in service once it reaches its average lifetime of use. Revised emission estimates using improved models for equipment age at end-of-life, inventories, and leak rates specific to California resulted in F-gas emissions estimates in closer agreement to ambient-based measurements. The discrepancies between inventory-based estimates and ambient-based measurements were reduced from -42% to -6% for CFC-12, and from +114% to +9% for HFC-134a.

NEBULAR EMISSION-LINES IN IRAS 10215-5916

NARCIS (Netherlands)

GARCIALARIO, P; MANCHADO, A; PARTHASARATHY, M; POTTASCH, [No Value

From low and high resolution spectroscopic observations of IRAS 10215 - 5916 we have discovered the presence of nebular emission lines in this G-type supergiant star in the post-AGB stage. From its high resolution spectrum we derived an expansion velocity of 17 km s-1 for the shell, similar to the

Greenhouse-gas emissions from biomass energy use: Comparison with other energy technologies

International Nuclear Information System (INIS)

Morris, G.P.; Norman, N.A.; Gleick, P.H.

1991-01-01

Recently a major new concern has arisen: the accumulation of greenhouse gases in the atmosphere. It is now generally believed that continued emissions of these gases are current or increasing levels will lead to significant climatic changes with the potential for dramatic, adverse impacts. Since the major anthropogenic source of greenhouse gas emissions is energy production and use, it is essential to future energy policy to understand how energy sources differ with respect to greenhouse gas emissions. Characterizing the greenhouse gas emissions associated with biomass energy use is extremely complicated. It is necessary to consider both the source and alternative use of the biomass material and its alternative disposal (if any), as well as the biomass energy application itself. It is desirable also to consider not just CO 2 emissions, but also CH 4 and N 2 O, both potent greenhouse gases. The authors' analysis shows that in many cases biomass energy use can actually help to ameliorate the greenhouse effect by converting emissions that would have been CH 4 into the less potent greenhouse gas CO 2 . In many cases the beneficial effect is very dramatic. This major new research result should help increase public support for biomass research and development, and for further development of waste conversion technology and installations

Extreme Ultraviolet Emission Lines of Iron Fe XI-XIII

Science.gov (United States)

Lepson, Jaan; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Brickhouse, N. S.; Dupree, A. K.

2013-04-01

The extreme ultraviolet (EUV) spectral region (ca. 20--300 Å) is rich in emission lines from low- to mid-Z ions, particularly from the middle charge states of iron. Many of these emission lines are important diagnostics for astrophysical plasmas, providing information on properties such as elemental abundance, temperature, density, and even magnetic field strength. In recent years, strides have been made to understand the complexity of the atomic levels of the ions that emit the lines that contribute to the richness of the EUV region. Laboratory measurements have been made to verify and benchmark the lines. Here, we present laboratory measurements of Fe XI, Fe XII, and Fe XIII between 40-140 Å. The measurements were made at the Lawrence Livermore electron beam ion trap (EBIT) facility, which has been optimized for laboratory astrophysics, and which allows us to select specific charge states of iron to help line identification. We also present new calculations by the Hebrew University - Lawrence Livermore Atomic Code (HULLAC), which we also utilized for line identification. We found that HULLAC does a creditable job of reproducing the forest of lines we observed in the EBIT spectra, although line positions are in need of adjustment, and line intensities often differed from those observed. We identify or confirm a number of new lines for these charge states. This work was supported by the NASA Solar and Heliospheric Program under Contract NNH10AN31I and the DOE General Plasma Science program. Work was performed in part under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC52-07NA27344.