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Sample records for lya emission due

  1. What is the physical origin of strong Lya emission? II. Gas Kinematics and Distribution of Lya Emitters

    CERN Document Server

    Shibuya, Takatoshi; Nakajima, Kimihiko; Hashimoto, Takuya; Ono, Yoshiaki; Rauch, Michael; Gauthier, Jean-Rene; Shimasaku, Kazuhiro; Goto, Ryosuke; Mori, Masao; Umemura, Masayuki

    2014-01-01

    We present a statistical study of velocities of Lya, interstellar (IS) absorption, and nebular lines and gas covering fraction for Lya emitters (LAEs) at z~2. We make a sample of 22 LAEs with a large Lya equivalent width (EW) of > 50A based on our deep Keck/LRIS observations, in conjunction with spectroscopic data from the Subaru/FMOS program and the literature. We estimate the average velocity offset of Lya from a systemic redshift determined with nebular lines to be dv_Lya=234+-9 km s-1. Using a Kolmogorv-Smirnov test, we confirm the previous claim of Hashimoto et al. (2013) that the average dv_Lya of LAEs is smaller than that of LBGs. Our LRIS data successfully identify blue-shifted multiple IS absorption lines in the UV continua of four LAEs on an individual basis. The average velocity offset of IS absorption lines from a systemic redshift is dv_IS=204+-27 km s-1, indicating LAE's gas outflow with a velocity comparable to typical LBGs. Thus, the ratio, R^Lya_ IS = dv_Lya/dv_IS of LAEs, is around unity, su...

  2. Resolving the optical emission lines of Lya blob 'B1' at z=2.38: another hidden quasar

    OpenAIRE

    Overzier, R. A.; Nesvadba, N. P. H.; Dijkstra, M.; Hatch, N. A.; Lehnert, M.D.; Villar-Martín, M.; Wilman, R. J.; Zirm, A. W.

    2013-01-01

    We have used the SINFONI near-infrared integral field unit on the VLT to resolve the optical emission line structure of one of the brightest (L~1e44 erg/s) and nearest (z=2.38) of all Lya blobs (LABs). The target, known in the literature as object 'B1' (Francis et al. 1996), lies at a redshift where the main optical emission lines are accessible in the observed near-infrared. We detect luminous [OIII]4959,5007A and Ha emission with a spatial extent of at least 32x40 kpc (4"x5"). The dominant ...

  3. Resolving the optical emission lines of Lya blob 'B1' at z=2.38: another hidden quasar

    CERN Document Server

    Overzier, R A; Dijkstra, M; Hatch, N A; Lehnert, M D; Villar-Martín, M; Wilman, R J; Zirm, A W

    2013-01-01

    We have used the SINFONI near-infrared integral field unit on the VLT to resolve the optical emission line structure of one of the brightest (L~1e44 erg/s) and nearest (z=2.38) of all Lya blobs (LABs). The target, known in the literature as object 'B1' (Francis et al. 1996), lies at a redshift where the main optical emission lines are accessible in the observed near-infrared. We detect luminous [OIII]4959,5007A and Ha emission with a spatial extent of at least 32x40 kpc (4"x5"). The dominant optical emission line component shows relatively broad lines (600-800 km/s, FWHM) and line ratios consistent with AGN-photoionization. The new evidence for AGN photoionization, combined with previously detected CIV and luminous, warm infrared emission, suggest that B1 is the site of a hidden quasar. This is confirmed by the fact that [OII] is relatively weak compared to [OIII] (extinction-corrected [OIII]/[OII] of about 3.8), which is indicative of a high, Seyfert-like ionization parameter. From the [OIII] luminosity we i...

  4. Mapping the low surface brightness Universe in the UV band with Lya emission from IGM filaments

    CERN Document Server

    Silva, Marta B; Zaroubi, Saleem

    2016-01-01

    A large fraction of the baryonic matter in the Universe is located in filaments in the intergalactic medium. However, the low surface brightness of these filaments has not yet allowed their direct detection except in very special regions in the circum-galactic medium (CGM). Here we simulate the intensity and spatial fluctuations in Lyman Alpha ${\\rm (Ly\\alpha)}$ emission from filaments in the intergalactic medium (IGM) and discuss the prospects for the next generation of space based instruments to detect the low surface brightness universe at UV wavelengths. Starting with a high resolution N-body simulation we obtain the dark matter density fluctuations and associate baryons with the dark matter particles assuming that they follow the same spatial distribution. The IGM thermal and ionization state is set by a model of the UV background and by the relevant cooling processes for a hydrogen and helium gas. The ${\\rm Ly\\alpha}$ emissivity is then estimated, taking into account recombination and collisional excita...

  5. The CALYMHA survey: Lya luminosity function and global escape fraction of Lya photons at z=2.23

    CERN Document Server

    Sobral, David; Best, Philip; Stroe, Andra; Röttgering, Huub; Oteo, Iván; Smail, Ian; Morabito, Leah; Paulino-Afonso, Ana

    2016-01-01

    We present the CAlibrating LYMan-$\\alpha$ with H$\\alpha$ (CALYMHA) pilot survey and new results on Lyman-$\\alpha$ (Lya) selected galaxies at z~2. We use a custom-built Lya narrow-band filter at the Isaac Newton Telescope, designed to provide a matched volume coverage to the z=2.23 Ha HiZELS survey. Here we present the first results for the COSMOS and UDS fields. Our survey currently reaches a 3$\\sigma$ line flux limit of ~4x10$^{-17}$ erg/s/cm$^{2}$, and a Lya luminosity limit of ~10$^{42.3}$ erg/s. We find 188 Lya emitters over 7.3x10$^5$ Mpc$^{3}$, but also find significant numbers of other line emitting sources corresponding to HeII, CIII] and CIV emission lines. These sources are important contaminants, and we carefully remove them, unlike most previous studies. We find that the Lya luminosity function at z=2.23 is very well described by a Schechter function up to L~10$^{43}$ erg/s with L$^*=10^{42.59+-0.05}$ erg/s, $\\phi^*=10^{-3.09+-0.08}$ Mpc$^{-3}$ and $\\alpha$=-1.75+-0.15. Above L~10$^{43}$ erg/s the...

  6. A Successful Broad-band Survey for Giant Lya Nebulae II: Spectroscopic Confirmation

    CERN Document Server

    Prescott, Moire K M; Jannuzi, Buell T

    2012-01-01

    Using a systematic broad-band search technique, we have carried out a survey for large Lya nebulae (or Lya "blobs") at 2Lya nebulae. Of 26 candidates targeted, 5 were confirmed to have Lya emission at 1.7Lya nebulae span a range of Lya equivalent widths, colors, sizes, and line ratios, and most show spatially-extended continuum emission. The remaining candidates did not reveal any strong emission lines, but instead exhibit featureless, diffuse, blue continuum spectra. Their nature remains mysterious, but we speculate that some of these might be Lya nebulae lying within the redshift desert (i.e., 1.2

  7. GHG emissions due to deforestation

    Energy Technology Data Exchange (ETDEWEB)

    Croezen, H.; Van Valkengoed, M.

    2009-05-15

    An assessment was made for the magnitude of greenhouse gas emissions resulting from deforestation and forest degradation in tropical forests in Malaysia and Indonesia related to Dutch economic activities. Greenhouse gas emissions (GHG) are calculated in relation to (1) the emissions related to vegetation removal sec; and (2) the emissions related to removal and more long term effects related to assimilation of CO2 in forest regrowth and changes in organic material in soils. Emissions related to vegetation removal and aggregated emissions for both vegetation removal and long term effects are reported separately. Soil organic carbon stock changes are considered by Greenpeace as more uncertain, so the emphasis will be on the direct emissions. Changes in carbon stocks and N2O emissions and actually also changes in vegetation all are events that occur gradually, rather than immediately. Only removal of existing vegetation and possible burning of this vegetation and associated emissions related to both activities are immediate by nature. Carbon stocks and N2O emissions change to a new level within several decades after deforestation or forest degradation. Removed vegetation can grow back or be replaced eventually by other vegetation, thereby changing the net greenhouse gas (GHG) emissions related to deforestation or forest degradation. Vegetation extracted for commercial purposes such as timber or pulp will also take years or decades to become waste and be converted into CO2. In IPCC and LCA's all these emissions are taken into account - or at least all emissions occurring within a period of 20 years, as required by IPCC. Soil organic carbon stock changes are also considered by Greenpeace as more uncertain, so the emphasis will be on the direct emmissions.

  8. Gravitationally Lensed Galaxies at 2Lya Emitters

    CERN Document Server

    Christensen, Lise; Richard, Johan; Hjorth, Jens; Milvang-Jensen, Bo; Dessauges-Zavadsky, Miroslava; Limousin, Marceau; Grillo, Claudio; Ebeling, Harald

    2012-01-01

    Strong gravitational lensing magnifies the flux from distant galaxies, allowing us to detect emission lines that would otherwise fall below the detection threshold for medium-resolution spectroscopy. Here we present the detection of temperature-sensitive oxygen emission lines from three galaxies at 22 for which this has been possible. The three galaxies have ~10% solar oxygen abundances in agreement with strong emission line diagnostics. Carbon and nitrogen ratios relative to oxygen are sub-solar as expected for young metal-poor galaxies. Two of the galaxies are Lya emitters with rest-frame equivalent widths of 60 A and 80 A, respectively, and their high magnification factors allow us for the first time to gain insight into the physical characteristics of high-redshift Lya emitters. Using constraints from the physical properties of the galaxies, we accurately reproduce their line profiles with radiative transfer models. The models show a relatively small outflow in agreement with the observed small velocity o...

  9. Quasars Probing Quasars IV: Joint Constraints on the Circumgalactic Medium from Absorption and Emission

    CERN Document Server

    Hennawi, Joseph F

    2013-01-01

    We have constructed a sample of 29 close projected quasar pairs where the background quasar spectrum reveals absorption from optically thick HI gas associated with the foreground quasar. These unique sightlines allow us to study the quasar circumgalactic medium (CGM) in absorption and emission simultaneously, because the background quasar pinpoints large concentrations of gas where Ly-a emission, resulting from quasar-powered fluorescence, resonant Ly-a scattering, and/or cooling radiation, is expected. A sensitive slit-spectroscopic search (1-sigma limits of SB_Lya ~= 3e-18 erg/s/cm^2/arcsec^2) for diffuse Ly-a emission in the environments of the foreground quasars is conducted. We fail to detect large-scale ~ 100 kpc Ly-a emission, either at the location of the optically thick absorbers or in the foreground quasar halos, in all cases except a single system. We interpret these non-detections as evidence that the gas detected in absorption is shadowed from the quasar UV radiation due to obscuration effects, w...

  10. Submillimeter observations of the J2142-4423 Lya protocluster at z = 2.38

    CERN Document Server

    Beelen, A; Kovács, A; Lagache, G; De Breuck, C; Weiss, A; Menten, K M; Colbert, J W; Dole, H; Siringo, G; Kreysa, E

    2008-01-01

    We present observations aimed at exploring both the nature of Lya emitting nebulae (Lya blobs) at z=2.38 and the way they trace large scale structure (LSS), by exploring their proximity to maximum starbursts through submillimeter emission. Our most important objectives are to make a census of associated submillimeter galaxies (SMGs), check their properties, and look for a possible overdensity in the protocluster J2142-4426 at z=2.38. We used the newly commissioned Large APEX Bolometer Camera (LABoCa) on the Atacama Pathfinder EXperiment (APEX) telescope, in its Science Verification phase, to carry out a deep 10'x10' map at 870 micron, and we performed multiple checks of the quality of data processing and source extraction. Our map, the first published deep image, confirms the capabilities of APEX/LABoCa as the most efficient current equipment for wide and deep submm mapping. Twenty-two sources were securely extracted with 870 micron flux densities in the range 3-21 mJy, rms noise 0.8-2.4 mJy, and far-IR lumin...

  11. Probing the IGM/Galaxy Connection V: On the Origin of Lya and OVI Absorption at z<0.2

    CERN Document Server

    Prochaska, J Xavier; Chen, H -W; Mulchaey, J S; Cooksey, K L

    2011-01-01

    We analyze the association of galaxies to Lya and OVI absorption, the most commonly detected transitions in the low-z intergalactic medium (IGM), in the fields of 14 quasars with z_em = 0.06-0.57. Confirming previous studies, we observe a high covering fraction for Lya absorption to impact parameter rho = 300kpc: 33/37 of our L>0.01L* galaxies show Lya equivalent width W_Lya>50mA. Galaxies of all luminosity L>0.01L* and spectral type are surrounded by a diffuse and ionized circumgalactic medium (CGM), whose baryonic mass is estimated at ~10^(10.5 +/- 0.3) Msun for a constant N_H. The virialized halos and extended CGM of present-day galaxies are responsible for most strong Lya absorbers (W_Lya > 300mA) but cannot reproduce the majority of observed lines in the Lya forest. We conclude that the majority of Lya absorption with W_Lya=30-300mA occurs in the cosmic web predicted by cosmological simulations and estimate a characteristic width for these filaments of ~400kpc. Regarding OVI, we observe a near unity cove...

  12. Seasonal climate change patterns due to cumulative CO2 emissions

    Science.gov (United States)

    Partanen, Antti-Ilari; Leduc, Martin; Damon Matthews, H.

    2017-07-01

    Cumulative CO2 emissions are near linearly related to both global and regional changes in annual-mean surface temperature. These relationships are known as the transient climate response to cumulative CO2 emissions (TCRE) and the regional TCRE (RTCRE), and have been shown to remain approximately constant over a wide range of cumulative emissions. Here, we assessed how well this relationship holds for seasonal patterns of temperature change, as well as for annual-mean and seasonal precipitation patterns. We analyzed an idealized scenario with CO2 concentration growing at an annual rate of 1% using data from 12 Earth system models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Seasonal RTCRE values for temperature varied considerably, with the highest seasonal variation evident in the Arctic, where RTCRE was about 5.5 °C per Tt C for boreal winter and about 2.0 °C per Tt C for boreal summer. Also the precipitation response in the Arctic during boreal winter was stronger than during other seasons. We found that emission-normalized seasonal patterns of temperature change were relatively robust with respect to time, though they were sub-linear with respect to emissions particularly near the Arctic. Moreover, RTCRE patterns for precipitation could not be quantified robustly due to the large internal variability of precipitation. Our results suggest that cumulative CO2 emissions are a useful metric to predict regional and seasonal changes in precipitation and temperature. This extension of the TCRE framework to seasonal and regional climate change is helpful for communicating the link between emissions and climate change to policy-makers and the general public, and is well-suited for impact studies that could make use of estimated regional-scale climate changes that are consistent with the carbon budgets associated with global temperature targets.

  13. Boosting Lya and HeII 1640A Line Fluxes from Pop III Galaxies: Stochastic IMF Sampling and Departures from Case-B

    CERN Document Server

    Mas-Ribas, Lluís; Forero-Romero, Jaime E

    2016-01-01

    We revisit calculations of nebular hydrogen Lya and HeII 1640A line strengths for population III galaxies, undergoing continuous and bursts of star formation. We focus on initial mass functions (IMFs) motivated by recent theoretical studies, which generally span a lower range of stellar masses than earlier works. We also account for case-B departures and the stochastic sampling of the IMF. In agreement with previous works, we find that departures from case-B can enhance the Lya flux by a factor of a few, but we argue that this enhancement is driven mainly by collisional excitation and ionization, and not due to photoionization from the n = 2 state of atomic hydrogen. The increased sensitivity of the Lya flux to the high-energy end of the galaxy spectrum makes it more subject to stochastic sampling of the IMF. The latter introduces a dispersion in the predicted nebular line fluxes around the deterministic value by as much as a factor of ~4. In contrast, the stochastic sampling of the IMF has less impact on the...

  14. Warm Gas in the Virgo Cluster: I. Distribution of Lya Absorbers

    CERN Document Server

    Yoon, Joo Heon; Thom, Christopher; Chen, Hsiao-Wen; Bryan, Greg

    2012-01-01

    The first systematic study of the warm gas (T=10^4-5 K) distribution across a galaxy cluster is presented using multiple background QSOs to the Virgo Cluster. We detect 25 Lya absorbers (N_HI = 10^13.1-15.4 cm^-2) in the Virgo velocity range toward 9 of 12 QSO sightlines observed with COS, with a cluster impact parameter range of 0.25-1.15 Mpc (0.23-1.05Rvir). Including 18 previously STIS or GHRS detected Lya absorbers toward 7 of 11 background QSOs in and around the Virgo Cluster, we establish a sample of 43 absorbers towards a total of 23 background probes for studying the incidence of Lya absorbers in and around the Virgo Cluster. With these absorbers, we find: 1) Warm gas is predominantly in the outskirts of the cluster and avoids the X-ray detected hot ICM. Also, Lya absorption strength increases with a cluster impact parameter. 2) Lya absorbing warm gas traces cold HI emitting gas in the substructures of the Virgo Cluster. 3) Including the absorbers associated with the surrounding substructures, the war...

  15. Large-scale clustering of Lyman-alpha emission intensity from SDSS/BOSS

    CERN Document Server

    Croft, Rupert A C; Zheng, Zheng; Bolton, Adam; Dawson, Kyle S; Peterson, Jeffrey B; York, Donald G; Eisenstein, Daniel; Brinkmann, Jon; Brownstein, Joel; Delubac, Timothée; Font-Ribera, Andreu; Hamilton, Jean-Christophe; Lee, Khee-Gan; Myers, Adam; Palanque-Delabrouille, Nathalie; Pâris, Isabelle; Petitjean, Patrick; Pieri, Matthew M; Ross, Nicholas P; Rossi, Graziano; Schlegel, David J; Schneider, Donald P; Slosar, Anže; Vazquez, José; Viel, Matteo; Weinberg, David H; Yèche, Christophe

    2015-01-01

    (Abridged) We detect the large-scale structure of Lya emission in the Universe at redshifts z=2-3.5 by measuring the cross-correlation of Lya surface brightness with quasars in SDSS/BOSS. We use a million spectra targeting Luminous Red Galaxies at z, the amplitude of mass fluctuations, and the quasar and Lya emission bias factors. Using known values, we infer (b_alpha/3) = (3.9 +/- 0.9) x 10^-21 erg/s cm^-2 A^-1 arcsec^-2, where b_alpha is the Lya emission bias factor. If the dominant sources of Lya emission are star forming galaxies, we infer rho_SFR = (0.28 +/- 0.07) (3/b_alpha) /yr/Mpc^3 at z=2-3.5. For b_alpha=3, this value is a factor of 21-35 above previous estimates from individually detected Lya emitters, although consistent with the total rho_SFR derived from dust-corrected, continuum UV surveys. 97% of the Lya emission in the Universe at these redshifts is therefore undetected in previous surveys of Lya emitters. Our measurement is much greater than seen from stacking analyses of faint halos surroun...

  16. A combined Pòlya process and mixture distribution approach to rainfall modelling

    Directory of Open Access Journals (Sweden)

    E. Todini

    1997-01-01

    Full Text Available A new probabilistic interpretation of at site rainfall sequences is introduced for the development of a stochastic model of rain. The model, is divided into two sub models; the first one describing the total number of rainfall spells within a window of time is described by a Pòlya process in order to reproduce better the variable probability of occurrence of rainfall during storm events (due to the presence of different numbers of rainfall cells; the second sub model, conditional on the first one, describes the total quantity of rainfall in the time window, given a number of rainfall spells. The probabilistic rainfall model, which has shown interesting properties in reproducing the probability distribution of observed data at time scales ranging from one hour to twenty-four hours, may be the basis for a number of applications which include the development of a conditional stochastic generator of rain, within the frame of real-time flood forecasting, and the derivation of a probabilistic distribution of rainfall extremes at the various time scales.

  17. Irreversible climate change due to carbon dioxide emissions.

    Science.gov (United States)

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-02-10

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the "dust bowl" era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4-1.0 m if 21st century CO(2) concentrations exceed 600 ppmv and 0.6-1.9 m for peak CO(2) concentrations exceeding approximately 1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.

  18. Characterizing and Quantifying Emissions and Transport of Fugitive Dust Emissions Due to Department of Defense Activities

    Science.gov (United States)

    2015-09-19

    transfer standard measurement may or may not be linear , but can be established empirically once, and then utilized to conduct a multitude of...for a range of types of wheeled vehicles due to the essentially linear nature of the relationship between dust emissions and vehicle weight and...rates of rotation of the PI-SWERL® annular blade. Forty-one roughness configurations were fitted to the viscometer-device to evaluate the

  19. Stimulated terahertz emission due to electronic Raman scattering in silicon

    NARCIS (Netherlands)

    Pavlov, S. G.; Bottger, U.; Hovenier, J. N.; Abrosimov, N. V.; Riemann, H.; Zhukavin, R. K.; Shastin, V. N.; Redlich, B.; van der Meer, A. F. G.; Hubers, H. W.

    2009-01-01

    Stimulated Raman emission in the terahertz frequency range (4.8-5.1 THz and 5.9-6.5 THz) has been realized by optical excitation of arsenic donor centers in silicon at low temperatures. The Stokes shift of the observed laser emission is 5.42 THz which is equal to the Raman-active donor electronic tr

  20. Fourfold higher tundra volatile emissions due to arctic summer warming

    Science.gov (United States)

    Lindwall, Frida; Schollert, Michelle; Michelsen, Anders; Blok, Daan; Rinnan, Riikka

    2016-03-01

    Biogenic volatile organic compounds (BVOCs), which are mainly emitted by vegetation, may create either positive or negative climate forcing feedbacks. In the Subarctic, BVOC emissions are highly responsive to temperature, but the effects of climatic warming on BVOC emissions have not been assessed in more extreme arctic ecosystems. The Arctic undergoes rapid climate change, with air temperatures increasing at twice the rate of the global mean. Also, the amount of winter precipitation is projected to increase in large areas of the Arctic, and it is unknown how winter snow depth affects BVOC emissions during summer. Here we examine the responses of BVOC emissions to experimental summer warming and winter snow addition—each treatment alone and in combination—in an arctic heath during two growing seasons. We observed a 280% increase relative to ambient in BVOC emissions in response to a 4°C summer warming. Snow addition had minor effects on growing season BVOC emissions after one winter but decreased BVOC emissions after the second winter. We also examined differences between canopy and air temperatures and found that the tundra canopy surface was on average 7.7°C and maximum 21.6°C warmer than air. This large difference suggests that the tundra surface temperature is an important driver for emissions of BVOCs, which are temperature dependent. Our results demonstrate a strong response of BVOC emissions to increasing temperatures in the Arctic, suggesting that emission rates will increase with climate warming and thereby feed back to regional climate change.

  1. Air emissions due to wind and solar power.

    Science.gov (United States)

    Katzenstein, Warren; Apt, Jay

    2009-01-15

    Renewables portfolio standards (RPS) encourage large-scale deployment of wind and solar electric power. Their power output varies rapidly, even when several sites are added together. In many locations, natural gas generators are the lowest cost resource available to compensate for this variability, and must ramp up and down quickly to keep the grid stable, affecting their emissions of NOx and CO2. We model a wind or solar photovoltaic plus gas system using measured 1-min time-resolved emissions and heat rate data from two types of natural gas generators, and power data from four wind plants and one solar plant. Over a wide range of renewable penetration, we find CO2 emissions achieve approximately 80% of the emissions reductions expected if the power fluctuations caused no additional emissions. Using steam injection, gas generators achieve only 30-50% of expected NOx emissions reductions, and with dry control NOx emissions increase substantially. We quantify the interaction between state RPSs and NOx constraints, finding that states with substantial RPSs could see significant upward pressure on NOx permit prices, if the gas turbines we modeled are representative of the plants used to mitigate wind and solar power variability.

  2. Pulsar high energy emission due to inverse Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Lyutikov, Maxim

    2013-06-15

    We discuss growing evidence that pulsar high energy is emission is generated via Inverse Compton mechanism. We reproduce the broadband spectrum of Crab pulsar, from UV to very high energy gamma-rays - nearly ten decades in energy, within the framework of the cyclotron-self-Compton model. Emission is produced by two counter-streaming beams within the outer gaps, at distances above ∼ 20 NS radii. The outward moving beam produces UV-X-ray photons via Doppler-booster cyclotron emission, and GeV photons by Compton scattering the cyclotron photons produced by the inward going beam. The scattering occurs in the deep Klein-Nishina regime, whereby the IC component provides a direct measurement of particle distribution within the magnetosphere. The required plasma multiplicity is high, ∼10{sup 6} – 10{sup 7}, but is consistent with the average particle flux injected into the pulsar wind nebula.

  3. Polarization of thermal bremsstrahlung emission due to electron pressure anisotropy

    CERN Document Server

    Komarov, S; Churazov, E; Schekochihin, A

    2016-01-01

    Astrophysical plasmas are typically magnetized, with the Larmor radii of the charged particles many orders of magnitude smaller than their collisional mean free paths. The fundamental properties of such plasmas, e.g., conduction and viscosity, may depend on the instabilities driven by the anisotropy of the particle distribution functions and operating at scales comparable to the Larmor scales. We discuss a possibility that the pressure anisotropy of thermal electrons could produce polarization of thermal bremsstrahlung emission. In particular, we consider coherent large-scale motions in galaxy clusters to estimate the level of anisotropy driven by stretching of the magnetic-field lines by plasma flow and by heat fluxes associated with thermal gradients. Our estimate of the degree of polarization is $\\sim 0.1 \\%$ at energies $\\gtrsim kT$. While this value is too low for the forthcoming generation of X-ray polarimeters, it is potentially an important proxy for the processes taking place at extremely small scale...

  4. Constraining cosmic reionization with quasar, gamma ray burst, and Lya emitter observations

    CERN Document Server

    Gallerani, S; Choudhury, T R; Fan, X; Salvaterra, R; Dayal, P

    2009-01-01

    We investigate the cosmic reionization history by comparing semi-analytical models of the Lya forest with observations of high-z quasars and gamma ray bursts absorption spectra. In order to constrain the reionization epoch z_rei, we consider two physically motivated scenarios in which reionization ends either early (ERM, z_rei>= 7) or late (LRM, z_rei~6). We analyze the transmitted flux in a sample of 17 quasars spectra at 5.7=11 and completes at z_rei>=7, in agreement with the recent WMAP5 data.

  5. The UV-Optical Albedo of Broad Emission Line Clouds

    CERN Document Server

    Korista, K T; Korista, Kirk; Ferland, Gary

    1997-01-01

    We explore the effective UV-optical albedos of a variety of types of broad emission line clouds, as well as their possible effects on the observed spectra of AGN. An important albedo source in moderately ionized ionization-bounded clouds is that due to neutral hydrogen: Rayleigh scattering of continuum photons off the extreme damping wings of Lya. The photons resulting from this scattering mechanism may contribute significantly to the Lya emission line, especially in the very broad wings. In addition, line photons emitted near 1200 Angstroms (e.g., N V 1240) that stream toward the neutral portion of the cloud may be reflected off this Rayleigh scattering mirror, so that they preferentially escape from the illuminated face. Inclusion of this effect can alter predicted emission line strengths and profiles. In more highly-ionized ionization-bounded clouds, Thompson scattering dominates the UV-optical albedo, but this albedo is lessened by the hydrogen gas opacity. These clouds are most reflective on the long wav...

  6. Even-harmonic generation due to spatially asymmetric emission

    CERN Document Server

    Ahmadi, H; Maghari, A

    2016-01-01

    Generation of even-order harmonics due to spatial symmetry breaking in high-order harmonic generation investigated by numerically solving one-dimensional electronic time-dependent Schr\\"{o}dinger equation beyond the Born-Oppenheimer approximation. The simple molecular ions H$_2^+$ and T$_2^+$ is chosen under a 14-cycle trapezoidal laser pulse at 800 nm wavelength and $I=$3 $\\times 10^{14}$ Wcm$^{-2}$ intensity. For an isotope (H$_2^+$) that has not a significant HHG at the laser falling edge, only odd harmonic orders are observed. Whereas, for one (T$_2^+$) with considerable HHG at the falling part of the laser pulse, frequency redshift occurs for odd-order harmonics and also even harmonic orders appear as a result of spatial symmetry breaking. To clarify further, spatial distribution of HHG and resolving HHG into different components are demonstrated. The contribution of different electronic states to the complexities in terms of internuclear distance is also demonstrated. The results also help to understand...

  7. The computation of carbon emissions due to the net payload on a truck

    DEFF Research Database (Denmark)

    Turkensteen, Marcel

    , it is necessary to compute the carbon emissions of these decisions. Current studies are only able to determine this for very specific conditions, such as a given vehicle under given driving conditions, and they may require many input parameters. Therefore, this paper presents a simple and broadly applicable...... emission computation tool. We determine the share of the carbon emissions of fully loaded vehicles due to the weight of the load on the vehicle, i.e. the load‐based emission percentage (LBEP). We conduct a review study on papers that report on carbon emissions or fuel consumption for different load factors...

  8. H I Column Densities, Metallicities, and Dust Extinction of Metal-Strong Damped Lya Systems

    CERN Document Server

    Kaplan, Kyle F; Herbert-Fort, Stephane; Ellison, Sara L; Dessauges-Zavadsky, Miroslava

    2010-01-01

    With the Blue Channel Spectrograph (BCS) on the MMT telescope, we have obtained spectra to the atmospheric cutoff of quasars previously known to show at least one absorption system at z>1.6 with very strong metal lines (candidate metal-strong damped Lya systems; cMSDLAs). The BCS/MMT spectra yield precise estimates of the HI column densities (NHI) of the systems through Voigt profile analysis of their Lya transitions. Nearly all of the cMSDLAs (41/43) satisfy the NHI criterion of DLAs, 10^20.3. As a population, these systems have systematically higher NHI values than DLAs chosen randomly from quasar sightlines. Combining our NHI measurements with previously measured metal column densities, we estimate metallicities for the MSDLAs. These systems have significantly higher values than randomly selected DLAs; at z~2, the MSDLAs show a median metallicity [M/H] ~ -0.67 that is 0.6dex higher than a corresponding control sample. This establishes MSDLAs as having amongst the most metal-rich gas in the high z universe....

  9. Induced Land Use Emissions due to First and Second Generation Biofuels and Uncertainty in Land Use Emission Factors

    Directory of Open Access Journals (Sweden)

    Farzad Taheripour

    2013-01-01

    Full Text Available Much research has estimated induced land use changes (ILUCs and emissions for first generation biofuels. Relatively little has provided estimates for the second generation biofuels. This paper estimates ILUC emissions for the first and second generation biofuels. Estimated ILUC emissions are uncertain not only because their associated land use changes are uncertain, but also because of uncertainty in the land use emission factors (EFs. This paper also examines uncertainties related to these factors. The results suggest that converting crop residues to biofuel has no significant ILUC emissions, but that is not the case for dedicated energy crops. Use of dedicated energy crops transfers managed natural land and marginal land (cropland-pasture to crop production. Producing biogasoline from miscanthus generates the lowest land requirement among alterative pathways. The largest land requirement is associated with switchgrass. The difference is due largely to the assumed yields of switchgrass and miscanthus. The three major conclusions from uncertainty in emissions analyses are (1 inclusion or exclusion of cropland-pasture makes a huge difference; (2 changes in soil carbon sequestration due to changes in land cover vegetation play an important role; and (3 there is wide divergence among the emission factor sources, especially for dedicated crop conversion to ethanol.

  10. Atmospheric emission of mercury due to combustion of steam coal and domestic coal in China

    Science.gov (United States)

    Wang, Shaobin; Luo, Kunli

    2017-08-01

    To study the mercury emission due to the combustion of steam coal and domestic coal in China, we analyzed the mercury contents of coal, fly ash, bottom ash and sluicing water in thermal power plants, steam boilers as well as domestic coal-stoves, in Shaanxi, Shanxi, Shandong and Yunnan Provinces. This study conduct an estimate of the Hg emission rates from steam coal and domestic coal combustion based on the method of mass distribution ratio of fly ash and bottom ash. The results show that the Hg emission rate of coal combustion in thermal power plants is about 50.21% (electrostatic precipitators + wet flue gas desulfurization), and that in heating boilers is about 67.23%, and 92.28% in industrial boilers without flue gas desulphurisation equipment. Furthermore, Hg emission rate is 83.61% due to domestic coal combustion in coal-stoves. The Hg emission amount into the atmosphere from power and heat generation, industrial boilers, domestic coal-stoves and spontaneous combustion of coal gangue is roughly estimated to be 133 ± 4, 100 ± 17, 11 ± 0.1 and 47 ± 26 tons in China in 2014, respectively, and the total Hg emission amount from this paper is estimated at 292 tons. The trends of Hg emission in China from 1991 to 2014 show an accelerating growth after 2002. The proportion of mercury emission due to thermal power, heating generation and industrial energy utilization continuously increased. The atmospheric emission of mercury due to combustion of steam coal, domestic coal and coal gangue accounts nearly 50% in total anthropogenic Hg emissions in China, indicating one of the largest sources of Hg emission in China which should draw more public and scientific attention in the future.

  11. Effects on carbon and nitrogen emissions due to swine manure removal for biofuel production.

    Science.gov (United States)

    Weaver, Kim H; Harper, Lowry A; Brown, Sarah M

    2012-01-01

    Methane (CH) and ammonia (NH) are emitted from swine-manure processing lagoons, contributing to global climate change and reducing air quality. Manure diverted to biofuel production is proposed as a means to reduce CH emissions. At a swine confined animal feeding operation in the U.S. Central Great Basin, animal manure was diverted from 12 farms to a biofuel facility and converted to methanol. Ammonia emissions were determined using the De Visscher Model from measured data of dissolved lagoon ammoniacal N concentrations, pH, temperature, and wind speed at the lagoon sites. Other lagoon gas emissions were measured with subsurface gas collection devices and gas chromatography analysis. During 2 yr of study, CO and CH emissions from the primary lagoons decreased 11 and 12%, respectfully, as a result of the biofuel process, compared with concurrently measured control lagoon emissions. Ammonia emissions increased 47% compared with control lagoons. The reduction of CH and increase in NH emissions agrees with a short-term study measured at this location by Lagrangian inverse dispersion analysis. The increase in NH emissions was primarily due to an increase in lagoon solution pH attributable to decreased methanogenesis. Also observed due to biofuel production was a 20% decrease in conversion of total ammoniacal N to N, a secondary process for the removal of N in anaerobic waste lagoons. The increase in NH emissions can be partially attributed to the decrease in N production by a proposed NH conversion to N mechanism. This mechanism predicts that a decrease in NH conversion to N increases ammoniacal N pH. Both effects increase NH emissions. It is unknown whether the decrease in NH conversion to N is a direct or physical result of the decrease in methanogenesis. Procedures and practices intended to reduce emissions of one pollutant can have an unintended consequence on the emissions of another pollutant.

  12. Elephant random walks and their connection to Pólya-type urns

    Science.gov (United States)

    Baur, Erich; Bertoin, Jean

    2016-11-01

    In this paper, we explain the connection between the elephant random walk (ERW) and an urn model à la Pólya and derive functional limit theorems for the former. The ERW model was introduced in [Phys. Rev. E 70, 045101 (2004), 10.1103/PhysRevE.70.045101] to study memory effects in a highly non-Markovian setting. More specifically, the ERW is a one-dimensional discrete-time random walk with a complete memory of its past. The influence of the memory is measured in terms of a memory parameter p between zero and one. In the past years, a considerable effort has been undertaken to understand the large-scale behavior of the ERW, depending on the choice of p . Here, we use known results on urns to explicitly solve the ERW in all memory regimes. The method works as well for ERWs in higher dimensions and is widely applicable to related models.

  13. Far-UV Emission Properties of FR1 Radio Galaxies

    CERN Document Server

    Danforth, Charles W; France, Kevin; Begelman, Mitchell C

    2016-01-01

    The power mechanism and accretion geometry for low-power FR1 radio galaxies is poorly understood in comparison to Seyfert galaxies and QSOs. In this paper, we use the diagnostic power of the Lya recombination line observed using the Cosmic Origins Spectrograph aboard HST to investigate the accretion flows in three well-known, nearby FR1s: M87, NGC4696, and HydraA. The Lya emission line's luminosity, velocity structure, variability and the limited knowledge of its spatial extent provided by COS are used to assess conditions within a few parsecs of the SMBH in these radio-mode AGN. We observe strong Lya emission in all three objects with similar total luminosity to that seen in BL Lacertae objects. M87 shows a complicated emission line profile in Lya which varies spatially across the COS aperture as well as temporally over several epochs of observation. Over the same observing epochs the UV continuum was seen to not vary, making it unlikely that the observed UV continuum is the ionizing source for Lya. In both ...

  14. Uncertainties in global aerosols and climate effects due to biofuel emissions

    Directory of Open Access Journals (Sweden)

    J. K. Kodros

    2015-04-01

    effects is unclear due to uncertainties in model inputs. This uncertainty limits our ability to introduce mitigation strategies aimed at reducing biofuel black carbon emissions in order to counter warming effects from greenhouse-gases. To better understand the climate impact of particle emissions from biofuel combustion, we recommend field/laboratory measurements to narrow constraints on: (1 emissions mass, (2 emission size distribution, (3 mixing state, and (4 ratio of black carbon to organic aerosol.

  15. Preparation to the CMB Planck analysis : contamination due to the polarized galactic emission

    CERN Document Server

    Fauvet, L

    2010-01-01

    The Planck satellite experiment, which was launched the 14th of may 2009, will give an accurate measurement of the anisotropies of the Cosmic Microwave Background (CMB) in temperature and polarization. This measurement is polluted by the presence of diffuse galactic polarized foreground emissions. In order to obtain the level of accuracy required for the Planck mission it is necessary to deal with these foregrounds. In order to do this, have develloped and implemented coherent 3D models of the two main galactic polarized emissions : the synchrotron and thermal dust emissions. We have optimized these models by comparing them to preexisting data : the K-band of the WMAP data, the ARCHEOPS data at 353 GHz and the 408 MHz all-sky continuum survey. By extrapolation of these models at the frequencies where the CMB is dominant, we are able to estimate the contamination to the CMB Planck signal due to these polarized galactic emissions.

  16. Anthropogenic dust emissions due to livestock trampling in a Mongolian temperate grassland

    Science.gov (United States)

    Munkhtsetseg, Erdenebayar; Shinoda, Masato; Ishizuka, Masahide; Mikami, Masao; Kimura, Reiji; Nikolich, George

    2017-09-01

    Mongolian grasslands are a natural dust source region and they contribute to anthropogenic dust due to the long tradition of raising livestock there. Past decades of abrupt changes in a nomadic society necessitate a study on the effects of livestock trampling on dust emissions, so that research studies may help maintain a sustainable ecosystem and well-conditioned atmospheric environment. In this study, we conducted a mini wind tunnel experiment (using a PI-SWERL® device) to measure dust emissions fluxes from trampling (at three disturbance levels of livestock density, N) and zero trampling (natural as the background level) at test areas in a Mongolian temperate grassland. Moreover, we scaled anthropogenic dust emissions to natural dust emissions as a relative consequence of livestock trampling. We found a substantial increase in dust emissions due to livestock trampling. This effect of trampling on dust emissions was persistent throughout all wind friction velocities, u* (varying from 0.44 to 0.82 m s-1). Significantly higher dust loading occurs after a certain disturbance level has been reached by the livestock trampling. Our results suggest that both friction velocity (u*) and disturbance level of livestock density (N) have an enormous combinational effect on dust emissions from the trampling test surface. This means that the effect of livestock trampling on dust emissions can be seen or revealed when wind is strong. Our results also emphasize that better management for livestock allocation coupled with strategies to prevent anthropogenic dust loads are needed. However, there are many uncertainties and assumptions to be improved on in this study.

  17. Damages and Expected Deaths Due to Excess NOx Emissions from 2009 to 2015 Volkswagen Diesel Vehicles.

    Science.gov (United States)

    Holland, Stephen P; Mansur, Erin T; Muller, Nicholas Z; Yates, Andrew J

    2016-02-01

    We estimate the damages and expected deaths in the United States due to excess emissions of NOx from 2009 to 2015 Volkswagen diesel vehicles. Using data on vehicle registrations and a model of pollution transport and valuation, we estimate excess damages of $430 million and 46 excess expected deaths. Accounting for uncertainty about emissions gives a range for damages from $350 million to $500 million, and a range for excess expected deaths from 40 to 52. Our estimates incorporate significant local heterogeneity: for example, Minneapolis has the highest damages despite having fewer noncompliant vehicles than 13 other cities. Our estimated damages greatly exceed possible benefits from reduced CO2 emissions due to increased fuel economy.

  18. 40 CFR 86.166-12 - Method for calculating emissions due to air conditioning leakage.

    Science.gov (United States)

    2010-07-01

    ... to air conditioning leakage. 86.166-12 Section 86.166-12 Protection of Environment ENVIRONMENTAL... for calculating emissions due to air conditioning leakage. This section describes procedures used to determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units. The...

  19. Net radiative forcing due to changes in regional emissions of tropospheric ozone precursors

    Science.gov (United States)

    Naik, Vaishali; Mauzerall, Denise; Horowitz, Larry; Schwarzkopf, M. Daniel; Ramaswamy, V.; Oppenheimer, Michael

    2005-12-01

    emissions of NOx, CO, and NMHCs, changes in O3 and CH4 concentrations result in a net negative radiative forcing (cooling). Thus we conclude that simultaneous reductions of CO, NMHCs, and NOx lead to a net reduction in radiative forcing due to resulting changes in tropospheric O3 and CH4 while reductions in NOx emissions alone do not.

  20. To Stack or Not to Stack: Spectral Energy Distribution Properties of Lya-Emitting Galaxies at z=2.1

    CERN Document Server

    Vargas, Carlos J; Acquaviva, Viviana; Gawiser, Eric; Finkelstein, Steven L; Ciardullo, Robin; Ashby, Matthew L N; Feldmeier, John; Ferguson, Henry; Gronwall, Caryl; Guaita, Lucia; Hagen, Alex; Koekemoer, Anton; Kurczynski, Peter; Newman, Jeffrey A; Padilla, Nelson

    2013-01-01

    We use the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) GOODS-S multi-wavelength catalog to identify counterparts for 20 Lya Emitting (LAE) galaxies at z=2.1. We build several types of stacked Spectral Energy Distributions (SEDs) of these objects. We combine photometry to form average and median flux-stacked SEDs, and postage stamp images to form average and median image-stacked SEDs. We also introduce scaled flux stacks that eliminate the influence of variation in overall brightness. We use the SED fitting code SpeedyMC to constrain the physical properties of individual objects and stacks. Our LAEs at z = 2.1 have stellar masses ranging from 2x10^7 Sollar Masses - 8x10^9 Solar Masses (median = 3x10^8 Solar Masses), ages ranging from 4 Myr to 500 Myr (median =100 Myr), and E(B-V) between 0.02 and 0.24 (median = 0.12). We do not observe strong correlations between Lya equivalent width (EW) and stellar mass, age, or E(B-V). The Lya radiative transfer (q) factors of our sample are pre...

  1. Keck Spectroscopy of Faint 3emission

    CERN Document Server

    Stark, Daniel P; Chiu, Kuenley; Ouchi, Masami; Bunker, Andrew

    2010-01-01

    We present results from a new Keck spectroscopic survey of UV-faint LBGs in the redshift range 3Lya emitters within the continuum-selected dropouts. By quantifying how the "Lya fraction" varies with redshift, we seek to constrain changes in Lya transmission associated with reionisation. In order to distinguish the effects of reionisation from other factors which affect the Lya fraction (e.g. dust, ISM kinematics), we study the luminosity and redshift-dependence of the Lya fraction over 3Lya emission much more frequently than luminous systems, and that at fixed luminosity, the prevalence of strong Lya emissio...

  2. Impact of warmer weather on electricity sector emissions due to building energy use

    Science.gov (United States)

    Meier, Paul; Holloway, Tracey; Patz, Jonathan; Harkey, Monica; Ahl, Doug; Abel, David; Schuetter, Scott; Hackel, Scott

    2017-06-01

    Most US energy consumption occurs in buildings, with cooling demands anticipated to increase net building electricity use under warmer conditions. The electricity generation units that respond to this demand are major contributors to sulfur dioxide (SO2) and nitrogen oxides (NOx), both of which have direct impacts on public health, and contribute to the formation of secondary pollutants including ozone and fine particulate matter. This study quantifies temperature-driven changes in power plant emissions due to increased use of building air conditioning. We compare an ambient temperature baseline for the Eastern US to a model-calculated mid-century scenario with summer-average temperature increases ranging from 1 C to 5 C across the domain. We find a 7% increase in summer electricity demand and a 32% increase in non-coincident peak demand. Power sector modeling, assuming only limited changes to current generation resources, calculated a 16% increase in emissions of NOx and an 18% increase in emissions of SO2. There is a high level of regional variance in the response of building energy use to climate, and the response of emissions to associated demand. The East North Central census region exhibited the greatest sensitivity of energy demand and associated emissions to climate.

  3. External costs of atmospheric Pb emissions: valuation of neurotoxic impacts due to inhalation

    Directory of Open Access Journals (Sweden)

    Frohn Lise

    2010-02-01

    Full Text Available Abstract Background The Impact Pathway Approach (IPA is an innovative methodology to establish links between emissions, related impacts and monetary estimates. Only few attempts have so far been presented regarding emissions of metals; in this study the external costs of airborne lead (Pb emissions are assessed using the IPA. Exposure to Pb is known to provoke impacts especially on children's cognition. As cognitive abilities (measured as IQ, intelligence quotient are known to have implications for lifetime income, a pathway can be established leading from figures for Pb emissions to the implied loss in earnings, and on this basis damage costs per unit of Pb emission can be assessed. Methods Different types of models are here linked. It is relatively straightforward to establish the relationship between Pb emissions and consequent increase in air-Pb concentration, by means of a Gaussian plume dispersion model (OML. The exposed population can then be modelled by linking the OML-output to population data nested in geo-referenced grid cells. Less straightforward is to establish the relationship between exposure to air-Pb concentrations and the resulting blood-Pb concentration. Here an Age-Dependent Biokinetic Model (ADBM for Pb is applied. On basis of previous research which established links between increases in blood-Pb concentrations during childhood and resulting IQ-loss we arrive at our results. Results External costs of Pb airborne emissions, even at low doses, in our site are in the range of 41-83 €/kg emitted Pb, depending on the considered meteorological year. This estimate applies only to the initial effects of air-Pb, as our study does not address the effects due to the Pb environmental-accumulation and to the subsequent Pb re-exposure. These are likely to be between one and two orders of magnitude higher. Conclusions Biokinetic modelling is a novel tool not previously included when applying the IPA to explore impacts of Pb emissions

  4. Reductions in aircraft particulate emissions due to the use of Fischer-Tropsch fuels

    Science.gov (United States)

    Beyersdorf, A. J.; Timko, M. T.; Ziemba, L. D.; Bulzan, D.; Corporan, E.; Herndon, S. C.; Howard, R.; Miake-Lye, R.; Thornhill, K. L.; Winstead, E.; Wey, C.; Yu, Z.; Anderson, B. E.

    2013-06-01

    The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX) was conducted in January-February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer-Tropsch (FT) process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions of 84% averaged over all powers) and blended fuels (64%) relative to the JP-8 baseline with the largest reductions at idle conditions. The alternative fuels also produced smaller soot (e.g. at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the FT fuel), which may reduce their ability to act as cloud condensation nuclei (CCN). The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the feedstock. As the plume cools downwind of the engine, nucleation-mode aerosols form. For the pure FT fuels, reductions (94% averaged over all powers) in downwind particle number emissions were similar to those measured at the exhaust plane (84

  5. Reductions in aircraft particulate emissions due to the use of Fischer–Tropsch fuels

    Directory of Open Access Journals (Sweden)

    A. J. Beyersdorf

    2013-06-01

    Full Text Available The use of alternative fuels for aviation is likely to increase due to concerns over fuel security, price stability and the sustainability of fuel sources. Concurrent reductions in particulate emissions from these alternative fuels are expected because of changes in fuel composition including reduced sulfur and aromatic content. The NASA Alternative Aviation Fuel Experiment (AAFEX was conducted in January–February 2009 to investigate the effects of synthetic fuels on gas-phase and particulate emissions. Standard petroleum JP-8 fuel, pure synthetic fuels produced from natural gas and coal feedstocks using the Fischer–Tropsch (FT process, and 50% blends of both fuels were tested in the CFM-56 engines on a DC-8 aircraft. To examine plume chemistry and particle evolution with time, samples were drawn from inlet probes positioned 1, 30, and 145 m downstream of the aircraft engines. No significant alteration to engine performance was measured when burning the alternative fuels. However, leaks in the aircraft fuel system were detected when operated with the pure FT fuels as a result of the absence of aromatic compounds in the fuel. Dramatic reductions in soot emissions were measured for both the pure FT fuels (reductions of 84% averaged over all powers and blended fuels (64% relative to the JP-8 baseline with the largest reductions at idle conditions. The alternative fuels also produced smaller soot (e.g. at 85% power, volume mean diameters were reduced from 78 nm for JP-8 to 51 nm for the FT fuel, which may reduce their ability to act as cloud condensation nuclei (CCN. The reductions in particulate emissions are expected for all alternative fuels with similar reductions in fuel sulfur and aromatic content regardless of the feedstock. As the plume cools downwind of the engine, nucleation-mode aerosols form. For the pure FT fuels, reductions (94% averaged over all powers in downwind particle number emissions were similar to those measured at the

  6. Quantifying uncertainties in N(2O emission due to N fertilizer application in cultivated areas.

    Directory of Open Access Journals (Sweden)

    Aurore Philibert

    Full Text Available Nitrous oxide (N(2O is a greenhouse gas with a global warming potential approximately 298 times greater than that of CO(2. In 2006, the Intergovernmental Panel on Climate Change (IPCC estimated N(2O emission due to synthetic and organic nitrogen (N fertilization at 1% of applied N. We investigated the uncertainty on this estimated value, by fitting 13 different models to a published dataset including 985 N(2O measurements. These models were characterized by (i the presence or absence of the explanatory variable "applied N", (ii the function relating N(2O emission to applied N (exponential or linear function, (iii fixed or random background (i.e. in the absence of N application N(2O emission and (iv fixed or random applied N effect. We calculated ranges of uncertainty on N(2O emissions from a subset of these models, and compared them with the uncertainty ranges currently used in the IPCC-Tier 1 method. The exponential models outperformed the linear models, and models including one or two random effects outperformed those including fixed effects only. The use of an exponential function rather than a linear function has an important practical consequence: the emission factor is not constant and increases as a function of applied N. Emission factors estimated using the exponential function were lower than 1% when the amount of N applied was below 160 kg N ha(-1. Our uncertainty analysis shows that the uncertainty range currently used by the IPCC-Tier 1 method could be reduced.

  7. Increase in dimethylsulfide (DMS emissions due to eutrophication of coastal waters offsets their reduction due to ocean acidification.

    Directory of Open Access Journals (Sweden)

    Nathalie eGypens

    2014-04-01

    Full Text Available Available information from manipulative experiments suggested that the emission of dimethylsulfide (DMS would decrease in response to the accumulation of anthropogenic CO2 in the ocean (ocean acidification. However, in coastal environments, the carbonate chemistry of surface waters was also strongly modified by eutrophication and related changes in biological activity (increased primary production and change in phytoplankton dominance during the last 50 years. Here, we tested the hypothesis that DMS emissions in marine coastal environments also strongly responded to eutrophication in addition to ocean acidification at decadal timescales. We used the R-MIRO-BIOGAS model in the eutrophied Southern Bight of the North Sea characterized by intense blooms of Phaeocystis that are high producers of dimethylsulfoniopropionate (DMSP, the precursor of DMS. We showed that, for the period from 1951 to 2007, eutrophication actually led to an increase of DMS emissions much stronger than the response of DMS emissions to ocean acidification.

  8. Stratospheric cooling and polar ozone loss due to H2 emissions of a global hydrogen economy

    Science.gov (United States)

    Feck, T.; Grooß, J.-U.; Riese, M.; Vogel, B.

    2009-04-01

    "Green" hydrogen is seen as a major element of the future energy supply to reduce greenhouse gas emissions substantially. However, due to the possible interactions of hydrogen (H2) with other atmospheric constituents there is a need to analyse the implications of additional atmospheric H2 that could result from hydrogen leakage of a global hydrogen infrastructure. Emissions of molecular H2 can occur along the whole hydrogen process chain which increase the tropospheric H2 burden. Across the tropical tropopause H2 reaches the stratosphere where it is oxidised and forms water vapour (H2O). This causes increased IR-emissions into space and hence a cooling of the stratosphere. Both effects, the increase of stratospheric H2O and the cooling, enhances the potential of chlorine activation on liquid sulfate aerosol and polar stratospheric clouds (PSCs), which increase polar ozone destruction. Hence a global hydrogen economy could provoke polar ozone loss and could lead to a substantial delay of the current projected recovery of the stratospheric ozone layer. Our investigations show that even if 90% of the current global fossil primary energy input could be replaced by hydrogen and approximately 9.5% of the product gas would leak to the atmosphere, the ozone loss would be increased between 15 to 26 Dobson Units (DU) if the stratospheric CFC loading would retain unchanged. A consistency check of the used approximation methods with the Chemical Lagrangian Model of the Stratosphere (CLaMS) shows that this additional ozone loss can probably be treated as an upper limit. Towards more realistic future H2 leakage rate assumptions (< 3%) the additional ozone loss would be rather small (? 10 DU). However, in all cases the full damage would only occur if stratospheric CFC-levels would retain unchanged. Due to the CFC-prohibition as a result of the Montreal Protocol the forecasts suggest a decline of the stratospheric CFC loading about 50% until 2050. In this case our calculations

  9. Climate and mortality changes due to reductions in household cooking emissions

    Science.gov (United States)

    Bergman, Tommi; Mielonen, Tero; Arola, Antti; Kokkola, Harri

    2016-04-01

    Household cooking is a significant cause for health and environmental problems in the developing countries. There are more than 3 billion people who use biomass for fuel in cooking stoves in their daily life. These cooking stoves use inadequate ventilation and expose especially women and children to indoor smoke. To reduce problems of the biomass burning, India launched an initiative to provide affordable and clean energy solutions for the poorest households by providing clean next-generation cooking stoves. The improved cooking stoves are expected to improve outdoor air quality and to reduce the climate-active pollutants, thus simultaneously slowing the climate change. Previous research has shown that the emissions of black carbon can be decreased substantially, as much as 90 % by applying better technology in cooking stoves. We have implemented reasonable (50% decrease) and best case (90% decrease) scenarios of the reductions in black and organic carbon due to improved cooking stoves in India into ECHAM-HAMMOZ aerosol-climate model. The global simulations of the scenarios will be used to study how the reductions of emissions in India affect the pollutant concentrations and radiation. The simulated reductions in particulate concentrations will also be used to estimate the decrease in mortality rates. Furthermore, we will study how the emission reductions would affect the global climate and mortality if a similar initiative would be applied in other developing countries.

  10. Payne-Pólya-Weinberger type inequality for eigenvalues of sub-Laplacian in the Engel group%Engel群上sub-Laplace算子特征值的Payne-Pólya-Weinberger不等式

    Institute of Scientific and Technical Information of China (English)

    薛晶晶

    2013-01-01

    为得到Engel群上的Payne-Polya-Weinberger不等式,采用Rayleigh-Ritz原理对Engel群上的sub-Laplace算子进行计算,得到了Engel群上sub-Laplace算子△E=X21+X22=∑X2i特征值的Payne-Polya-Weinberger不等式λm+1-λm≤2/m(m∑i=1λi),其中X1,X2是Engel群上的左不变向量场.%To get a Payne-Pólya-Weinberger type inequality on the Engel group,Rayleigh-Ritz principle is used to calculate the sub-Laplace operator of the Engel group and finally establish the Payne-PólyaWeinberger type inequalityλm+1-λm ≤ 2m∑i=1λifor adjacent eigenvalues on sub-Laplace operator △E=X23+X22=2∑i=1X2i,which X1,X2 be the left-invariant vector fields in the Engel group.

  11. Radio-wave emission due to hypervelocity impacts and its correlation with optical observations

    Science.gov (United States)

    Takano, T.; Maki, K.; Yamori, A.

    This paper describes the most interesting phenomena of radio-wave emission due to hypervelocity impacts. A projectile of polycarbonate with 1.1 g weight was accelerated by a rail gun to 3.8 km/sec, and hit two targets which are a 2 mm thick aluminum plate upstream and a 45 mm diameter aluminum column downstream, respectively. The projectile first breaks wires to give a triggering signal to a data recorder, then penetrates the aluminum plate, and finally hit the column, The emitted radio-waves propagate through the chamber window, and are received by antennas at each frequency band. The receivers in 22 GHz- and 2 GHz-bands consist of a low noise amplifier, a mixer, a local oscillator and an IF amplifier , respectively. The receiver in 1 MHz-band is a simple RF amplifier. The outputs of all receivers are fed to a data recorder which is actually a high-speed digital oscilloscope with a large amount of memory. The radio-waves were successfully recorded in 22 GHz-band with 500 MHz bandwidth, in 2 GHz-band with 300 MHz bandwidth, and in 1MHz-band. The waveforms in 22 GHz- and 2 GHz-bands coincide well each other, and are composed of two groups of sharp impulses with a separation of about 20 micro seconds. The width of an impulse is less than 2 n sec. which is the resolution limit of the data recorder. We carried out optical observations using an ultra-high speed camera simultaneously through another window of the chamber. The time interval between scenes is 2 micro sec. We can see a faint light of the projectile before the first impact to the plate, and then a brilliant gas exploding backward from the plate and forward to the column. After hitting the column target, the brilliant gas flows to the chamber wall and is reflected back to make a mixture with dark gas in the chamber. Excellent correlation between radio-wave emission and the observed optical phenomena was obtained in the experiment. It is easily conceived that the radio-waves consist of quite a wide frequency

  12. Consideration of the Change of Material Emission Signatures due to Longterm Emissions for Enhancing VOC Source Identification

    DEFF Research Database (Denmark)

    Han, K. H.; Zhang, J. S.; Knudsen, Henrik Nellemose

    2011-01-01

    The objectives of this study were to characterize the changes of VOC material emission profiles over time and develop a method to account for such changes in order to enhance a source identification technique that is based on the measurements of mixed air samples and the emission signatures of in...

  13. Consideration Of The Change Of Material Emission Signatures Due To Long-term Emissions For Enhancing Voc Source Identification

    DEFF Research Database (Denmark)

    Han, K. H.; Zhang, J. S.; Knudsen, H. N.

    2011-01-01

    The objectives of this study were to characterize the changes of VOC material emission profiles over time and develop a method to account for such changes in order to enhance a source identification technique that is based on the measurements of mixed air samples and the emission signatures of in...

  14. Early-age acoustic emission measurements in hydrating cement paste: Evidence for cavitation during solidification due to self-desiccation

    DEFF Research Database (Denmark)

    Lura, Pietro; Couch, J.; Jensen, Ole Mejlhede

    2009-01-01

    In this study, the acoustic emission activity of cement pastes was investigated during the first day of hydration. Deaired, fresh cement pastes were cast in sealed sample holders designed to minimize friction and restraint. The majority of acoustic emission events occurred in lower water to cement....... According to these experimental results, the acoustic emission measured around setting time was attributed to cavitation events occurring in the pores of the cement paste due to self-desiccation. This paper shows how acoustic emission might be used to indicate the time when the fluid–solid transition occurs...

  15. “HONRAR PAI E MÃE”: A INTERTEXTUALIDADE NUM ARTIGO DE OPINIÃO DE LYA LUFT / "HONOR FATHER AND MOTHER": THE INTERTEXTUALITY IN AN ARTICLE OF VIEW OF LYA LUFT

    OpenAIRE

    Sousa, Valdulce Ribeiro Cruz; Universidade Federal do Piauí-UFPI; Magalhães Neto, Pedro Rodrigues

    2014-01-01

    O objetivo deste artigo é analisar as marcas intertextuais, à luz da Linguística de Texto, na construção do artigo de opinião  Honrar Pai e Mãe, da escritora Lya Luft. Para tanto, toma-se como fundamento a concepção de “intertextualidade restrita” de Genette (1982 apud KOCH ET AL, 2007), que se define pelas relações de co-presença entre textos. Os resultados da análise permitem a constatação de marcas efetivas de vários textos na construção dos sentidos do referido artigo de opinião, indiciad...

  16. Reduction of CO2 Emissions Due to Wind Energy - Methods and Issues in Estimating Operational Emission Reductions

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, Hannele; Kiviluoma, Juha; McCann, John; Clancy, Matthew; Millgan, Michael; Pineda, Ivan; Eriksen, Peter Borre; Orths, Antje; Wolfgang, Ove

    2015-10-05

    This paper presents ways of estimating CO2 reductions of wind power using different methodologies. Estimates based on historical data have more pitfalls in methodology than estimates based on dispatch simulations. Taking into account exchange of electricity with neighboring regions is challenging for all methods. Results for CO2 emission reductions are shown from several countries. Wind power will reduce emissions for about 0.3-0.4 MtCO2/MWh when replacing mainly gas and up to 0.7 MtCO2/MWh when replacing mainly coal powered generation. The paper focuses on CO2 emissions from power system operation phase, but long term impacts are shortly discussed.

  17. HeII emission in Lyman-alpha nebulae: AGN or cooling radiation?

    CERN Document Server

    Scarlata, C; Teplitz, H I; Bridge, C; Francis, P; Palunas, P; Siana, B; Williger, G M; Woodgate, B

    2009-01-01

    We present a study of an extended Lyman-alpha (Lya) nebula located in a known overdensity at z~2.38. The data include multiwavelength photometry covering the rest-frame spectral range from 0.1 to 250um, and deep optical spectra of the sources associated with the extended emission. Two galaxies are associated with the Lya nebula. One of them is a dust enshrouded AGN, while the other is a powerful starburst, forming stars at >~600 Msol/yr. We detect the HeII emission line at 1640A in the spectrum of the obscured AGN, but detect no emission from other highly ionized metals (CIV or NV) as is expected from an AGN. One scenario that simultaneously reproduces the width of the detected emission lines, the lack of CIV emission, and the geometry of the emitting gas, is that the HeII and the Lya emission are the result of cooling gas that is being accreted on the dark matter halo of the two galaxies, Ly1 and Ly2. Given the complexity of the environment associated with our Lya nebula it is possible that various mechanism...

  18. External costs of atmospheric Pb emissions: valuation of neurotoxic impacts due to inhalation

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Thomsen, Marianne; Frohn, Lise

    2010-01-01

    The Impact Pathway Approach (IPA) is an innovative methodology to establish links between emissions, related impacts and monetary estimates. Only few attempts have so far been presented regarding emissions of metals; in this study the external costs of airborne lead (Pb) emissions are assessed...... using the IPA. Exposure to Pb is known to provoke impacts especially on children's cognition. As cognitive abilities (measured as IQ, intelligence quotient) are known to have implications for lifetime income, a pathway can be established leading from figures for Pb emissions to the implied loss...... in earnings, and on this basis damage costs per unit of Pb emission can be assessed....

  19. Emission inventory of NMVOC (Non Methane Volatile Organic Compounds) and simulations of ozone formation due to emissions of NO{sub x} and NMVOC in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Janhaell, S.; Andersson-Skoeld, Y.

    1997-01-01

    An emission inventory, covering the different source categories of ozone precursors in Sweden, has been performed. The emissions from each category, road traffic, working machinery, other mobile sources, wood combustion, energy production, industry, domestic use and pesticides, have been separated into 81 organic compounds and NO{sub x}. The emission data have been used in model simulations to predict the ozone formation due to the emission from different source categories. Four different ambient conditions have been treated. The results from this study indicate, as expected, that the road traffic is the single most important emitter of precursors significant in regional ozone production. POCP, or Photochemical Ozone Creation Potential, defined as the change in photochemical ozone production due to a change in the emission of that particular VOC, is used to compare different VOC in connection with ozone production. In this study the POCP was calculated for the whole group of compounds emitted from a specific source category. The results indicate that there is a big variety of ozone formation ability among source categories due to differences in composition, which clearly demonstrate the importance of a detailed description of the emissions. 48 refs, 5 figs, 6 tabs

  20. Hydrocarbons Emissions Due to Wellbore and other Subsurface Leakage in the Uintah Basin, Utah

    Science.gov (United States)

    Watkins, C.; Lyman, S. N.

    2015-12-01

    The explosive growth of oil and gas production in the United States has focused public and regulatory attention on environmental impacts of hydrocarbon extraction, including air quality and climate impacts. One potentially important emissions source is subsurface leakage of natural gas. Better understanding of wellbore and other subsurface leaks are important in providing ways to decrease pollution while increasing the efficiency of oil and gas production. Soil gas measurements carried out by USGS over the last several years in Utah's oil and gas fields have shown that, while concentrations of methane in soils near wells are typically low, soil gas near some wells can contain more than 50% methane. In the summers of 2013-2015 we carried out campaigns to measure the emission rate of methane and other hydrocarbons from soils near wells in the Uintah Basin, Utah. We also measured emissions at several locations on individual well pads and determined that concentrations of hydrocarbons tend to decrease with distance from the well head. Soil emissions were also measured at non-well sites in the same area to determine background emission rates. Emissions from exposed coal, oil shale, gilsonite, and fault zone surfaces were also measured. Relationships of emissions with soil gas concentrations, meteorological conditions, and soil properties were also investigated.

  1. Satellite based estimates of reduced CO and CO2 emissions due to traffic restrictions during the 2008 Beijing Olympics

    Science.gov (United States)

    Worden, H. M.; Cheng, Y.; Pfister, G.; Carmichael, G. R.; Zhang, Q.; Streets, D. G.; Deeter, M. N.; Edwards, D. P.; Gille, J. C.; Worden, J.

    2012-12-01

    We present estimates of the reductions in CO and CO2 emissions resulting from the control measures on the Beijing transportation sector taken during the 2008 Beijing Olympics. This study used MOPITT (Measurements Of Pollution In The Troposphere) multispectral satellite measurements of near surface CO along with WRF Chem (Weather Research and Forecasting model with Chemistry) simulations for Beijing during August, 2007 and 2008 to estimate changes in CO due to meteorology and emissions. Using fractional changes in the emissions inventory transportation sector along with a reported CO/CO2 emission ratio for Beijing vehicles, we find the corresponding reduction in CO2 emissions. We then compare this reduction to target CO2 emissions in the RCP (representative concentration pathway) scenarios being considered for the IPCC AR5 (Intergovernmental Panel on Climate Change, 5th Assessment Report). Our result suggests that urban traffic reductions could play a significant role in meeting target cuts for global CO2 emissions, even for the most aggressive control scenario (RCP2.6).

  2. Inter-annual variability in fossil-fuel CO2 emissions due to temperature anomalies

    Science.gov (United States)

    Bréon, F.-M.; Boucher, O.; Brender, P.

    2017-07-01

    It is well known that short-term (i.e. interannual) variations in fossil-fuel CO2 emissions are closely related to the evolution of the national economies. Nevertheless, a fraction of the CO2 emissions are linked to domestic and business heating and cooling, which can be expected to be related to the meteorology, independently of the economy. Here, we analyse whether the signature of the inter-annual temperature anomalies is discernible in the time series of CO2 emissions at the country scale. Our analysis shows that, for many countries, there is a clear positive correlation between a heating-degree-person index and the component of the CO2 emissions that is not explained by the economy as quantified by the gross domestic product (GDP). Similarly, several countries show a positive correlation between a cooling-degree-person (CDP) index and CO2 emissions. The slope of the linear relationship for heating is on the order of 0.5-1 kg CO2 (degree-day-person)-1 but with significant country-to-country variations. A similar relationship for cooling shows even greater diversity. We further show that the inter-annual climate anomalies have a small but significant impact on the annual growth rate of CO2 emissions, both at the national and global scale. Such a meteorological effect was a significant contribution to the rather small and unexpected global emission growth rate in 2014 while its contribution to the near zero emission growth in 2015 was insignificant.

  3. Global Health Benefits from Reductions in Background Tropospheric Ozone due to Methane Emission Controls

    Science.gov (United States)

    West, J. J.; Mauzerall, D. L.; Fiore, A. M.; Horowitz, L. W.

    2005-05-01

    Increases in background ozone throughout the troposphere are partially attributed to rising anthropogenic methane concentrations, which are projected to continue to increase in the future. Because methane is long-lived and affects background ozone, controls on methane emissions would reduce surface ozone concentrations fairly uniformly around the globe. Epidemiological research indicates that exposure to ozone increases incidence of respiratory ailments and premature mortality. In addition, exposure to ozone reduces agricultural yields and damages natural ecosystems. We use the MOZART-2 global atmospheric chemistry and transport model to estimate the effects on global surface ozone of perturbations in methane emissions. We consider a baseline scenario for 2000 and the 2030 A2 scenario (emissions from the IPCC AR-4 2030 atmospheric chemistry experiments), and examine the impact on ozone of decreasing anthropogenic methane emissions relative to this baseline by 20%. Using the simulated spatially-distributed decreases in surface ozone concentrations resulting from these reductions in methane emissions, we estimate the global benefits to human health in the methane emission reduction scenario. We focus on human mortality, and consider the sensitivity of our estimates to different assumptions of health effect thresholds at low ozone concentrations.

  4. Investigation of Io's auroral hiss emissions due to its motion in Jupiter's magnetosphere

    Institute of Scientific and Technical Information of China (English)

    Mohsen H. Moghimi

    2012-01-01

    The left-hand side of the auroral hiss emission observed by Galileo has a frequency time profile shaped very similar to the funnel shape observed in the Earth's auroral region.This close similarity indicates that we can use the theory of whistlermode propagation near the resonance cone to locate the emission source.The general characteristics of the whistler mode are discussed.Then the position of the emission source is investigated using a geometrical method that takes into account the trajectory of Galileo.Initially a point source is assumed.Then the possibility of a sheet source aligned along the magnetic field lines which are tangent to the surface of Io is investigated.Both types of sources show that the whistler mode radiation originates very close to the surface of Io.

  5. Investigation of Io's Auroral Hiss Emissions Due To Its Motion in Jupiter's Magnetosphere

    CERN Document Server

    Moghimi, M H

    2011-01-01

    The left-hand side of the auroral hiss emission observed by Galileo has a frequency time shaped very similar to the funnel shape observed in the earth's auroral region. This close similarity indicates that we can use the whistler-mode propagation near resonance cone to locate the emission source. In this paper the general characteristic of the whistler mode are discussed. Then the position of the emission source has been investigated using a geometry method that takes into account the Galileo's trajectory. Initially it is assumed the source is a point. Then the possibility of sheet source aligned along the magnetic field lines which are tangent to the surface of Io is investigated. Both of two types of sources show that the whistler mode radiation originates very close to the surface of the Io.

  6. Estimating PM2.5-associated mortality increase in California due to the Volkswagen emission control defeat device

    Science.gov (United States)

    Wang, Tianyang; Jerrett, Michael; Sinsheimer, Peter; Zhu, Yifang

    2016-11-01

    The Volkswagen Group of America (VW) was found by the US Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) to have installed "defeat devices" and emit more oxides of nitrogen (NOx) than permitted under current EPA standards. In this paper, we quantify the hidden NOx emissions from this so-called VW scandal and the resulting public health impacts in California. The NOx emissions are calculated based on VW road test data and the CARB Emission Factors (EMFAC) model. Cumulative hidden NOx emissions from 2009 to 2015 were estimated to be over 3500 tons. Adult mortality changes were estimated based on ambient fine particulate matter (PM2.5) change due to secondary nitrate formation and the related concentration-response functions. We estimated that hidden NOx emissions from 2009 to 2015 have resulted in a total of 12 PM2.5-associated adult mortality increases in California. Most of the mortality increase happened in metropolitan areas, due to their high population and vehicle density.

  7. C IV and He II Line Emission of Lyman Alpha Blobs: Powered by Shock Heated Gas

    CERN Document Server

    Cabot, Samuel H C; Zheng, Zheng

    2016-01-01

    Utilizing {\\it ab initio} ultra-high resolution hydrodynamical simulations, we investigate the properties of the interstellar and circum-galactic medium of Ly$\\alpha$ Blobs (LABs) at $z=3$, focusing on three important emission lines: Ly$\\alpha$ 1216\\AA, \\heii 1640\\AA\\ and \\civ 1449\\AA. Their relative strengths provide a powerful probe of the thermodynamic properties of the gas when confronted with observations. By adjusting the dust attenuation effect using one parameter and matching the observed size-luminosity relation of LABs using another parameter, we show that our simulations can reproduce the observed \\civ/\\lya\\ and \\heii/\\lya\\ ratios adequately. This analysis provides the first successful physical model to account for simultaneously the LAB luminosity function, luminosity-size relation, and the \\civ/Ly$\\alpha$ and \\heii/Ly$\\alpha$ ratios, with only two parameters. The physical underpinning for this model is that, in addition to the stellar component for the \\lya\\ emission, the \\lya\\ and \\civ\\ emission...

  8. Emissions due to the natural gas storage well-casing blowout at Aliso Canyon/SS-25

    Science.gov (United States)

    Herndon, Scott; Daube, Conner; Jervis, Dylan; Yacovitch, Tara; Roscioli, Joseph; Curry, Jason; Nelson, David; Knighton, Berk

    2017-04-01

    The pronounced increase in unconventional gas production in North America over the last fifteen years has intensified interest in understanding emissions and leaks in the supply chain from well pad to end use. Los Angeles, California is home 19 million consumers of natural gas in both industry and domestic end use. The well blowout at Aliso Canyon Natural Gas Storage Facility in the greater Los Angeles area was quantified using the tracer flux ratio method (TFR). Over 400 tracer plume transects were collected, each lasting 15-300 seconds, using instrumentation aboard a mobile platform on 25 days between December 21, 2015 and March 9, 2016. The leak rate from October 23rd to February 11th has been estimated here using a combination of this work (TFR) and the flight mass balance (FMB) data [Conley et al., 2016]. This estimate relies on the TFR data as the most specific SS-25 emission dataset. Scaling the FMB dataset, the leak rate is projected from Oct 23rd to December 21th. Adding up the emissions inferred and measured suggests a total leak burden of 86,022 ± 8,393 metric tons of methane. This work quantified the emissions during the "bottom kill" procedure which halted the primary emission leak. The ethane to methane enhancement ratio observed downwind of the leak site is consistent with the content of ethane in the natural gas at this site and provides definitive evidence that the methane emission rate quantified via tracer flux ratio is not due to a nearby landfill or other potential biogenic sources. Additionally, the TFR approach employed here is assessing only the leaks due to the SS-25 well blowout and excludes other possible emissions at the facility.

  9. Modelling assessment of regional groundwater contamination due to historic smelter emissions of heavy metals

    NARCIS (Netherlands)

    Grift, B. van der; Griffioen, J.

    2008-01-01

    Historic emissions from ore smelters typically cause regional soil contamination. We developed a modelling approach to assess the impact of such contamination on groundwater and surface water load, coupling unsaturated zone leaching modelling with 3D groundwater transport modelling. Both historic an

  10. Dust emission and soil loss due to anthropogenic activities by wind erosion simulations

    Science.gov (United States)

    Katra, Itzhak; Swet, Nitzan; Tanner, Smadar

    2017-04-01

    Wind erosion is major process of soil loss and air pollution by dust emission of clays, nutrients, and microorganisms. Many soils throughout the world are currently or potentially associated with dust emissions, especially in dryland zones. The research focuses on wind erosion in semi-arid soils (Northern Negev, Israel) that are subjected to increased human activities of urban development and agriculture. A boundary-layer wind tunnel has been used to study dust emission and soil loss by simulation and quantification of high-resolution wind processes. Field experiments were conducted in various surface types of dry loess soils. The experimental plots represent soils with long-term and short term influences of land uses such as agriculture (conventional and organic practices), grazing, and natural preserves. The wind tunnel was operated under various wind velocities that are above the threshold velocity of aeolian erosion. Total soil sediment and particulate matter (PM) fluxes were calculated. Topsoil samples from the experimental plots were analysed in the laboratory for physical and chemical characteristics including aggregation, organic matter, and high-resolution particle size distribution. The results showed variations in dust emission in response to surface types and winds to provide quantitative estimates of soil loss over time. Substantial loss of particulate matter that is resources and management strategies as well as for PM loading to the atmosphere and air pollution.

  11. The Spitzer discovery of a galaxy with infrared emission solely due to AGN activity

    CERN Document Server

    Hony, S; Woods, Paul M; van Loon, J Th; Gorjian, V; Madden, S C; Zijlstra, A A; Gordon, K D; Indebetouw, R; Marengo, M; Meixner, M; Panuzzo, P; Shiao, B; Sloan, G C; Roman-Duval, J; Mullaney, J; Tielens, A G G M

    2011-01-01

    We present a galaxy (SAGE1CJ053634.78-722658.5) at a redshift of 0.14 of which the IR is entirely dominated by emission associated with the AGN. We present the 5-37 um Spitzer/IRS spectrum and broad wavelength SED of SAGE1CJ053634, an IR point-source detected by Spitzer/SAGE (Meixner et al 2006). The source was observed in the SAGE-Spec program (Kemper et al., 2010) and was included to determine the nature of sources with deviant IR colours. The spectrum shows a redshifted (z=0.14+-0.005) silicate emission feature with an exceptionally high feature-to-continuum ratio and weak polycyclic aromatic hydrocarbon (PAH) bands. We compare the source with models of emission from dusty tori around AGNs from Nenkova et al. (2008). We present a diagnostic diagram that will help to identify similar sources based on Spitzer/MIPS and Herschel/PACS photometry. The SED of SAGE1CJ053634 is peculiar because it lacks far-IR emission and a clear stellar counterpart. We find that the SED and the IR spectrum can be understood as em...

  12. Changes in US background ozone due to global anthropogenic emissions from 1970 to 2020

    Science.gov (United States)

    Nopmongcol, Uarporn; Jung, Jaegun; Kumar, Naresh; Yarwood, Greg

    2016-09-01

    Estimates of North American and US Background (NAB and USB) ozone (O3) are critical in setting and implementing the US National Ambient Air Quality Standards (NAAQS) and therefore influence population exposure to O3 across the US. NAB is defined as the O3 concentration in the absence of anthropogenic O3 precursor emissions from North America whereas USB excludes anthropogenic emissions inside the US alone. NAB and USB vary geographically and with time of year. Analyses of O3 trends at rural locations near the west coast suggest that background O3 is rising in response to increasing non-US emissions. As the O3 NAAQS is lowered, rising background O3 would make attaining the NAAQS more difficult. Most studies of changing US background O3 have inferred trends from observations whereas air quality management decisions tend to rely on models. Thus, it is important that the models used to develop O3 management strategies are able to represent the changes in background O3 in order to increase confidence that air quality management strategies will succeed. We focus on how changing global emissions influence USB rather than the effects of inter-annual meteorological variation or long-term climate change. We use a regional model (CAMx) nested within a global model (GEOS-Chem) to refine our grid resolution over high terrain in the western US and near US borders where USB tends to be higher. We determine USB from CAMx simulations that exclude US anthropogenic emissions. Over five decades, from 1970 to 2020, estimated USB for the annual fourth highest maximum daily 8-h average O3 (H4MDA8) in the western US increased from mostly in the range of 40-55 ppb to 45-60 ppb, but remained below 45 ppb in the eastern US. USB increases in the southwestern US are consistent with rising emissions in Asia and Mexico. USB decreases in the northeast US after 1990 follow declining Canadian emissions. Our results show that the USB increases both for the top 30 MDA8 days and the H4MDA8 (the former

  13. Impurity line emission due to thermal charge exchange in JET edge plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Maggi, C.F.; Horton, L.D.; Koenig, R.; Stamp, M. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Summers, H.P. [Strathclyde Univ., Glasgow (United Kingdom)

    1994-07-01

    High n-shell emission from hydrogen-like carbon (C VI, n=8-7) has been routinely observed from the plasma edge of JET. By comparing the measured spectral line intensities with the signals predicted by advanced atomic physics modelling of carbon and hydrogen radiation, integrated with modelling of the divertor and edge plasma, it is concluded that charge transfer from excited state hydrogen donors into fully stripped carbon ions can account for the observed spectral emission, but that the hydrogen distribution and to a lesser extent the carbon distribution away from the strike zone predicted by the transport model are too low. Data presented are those of three upper X-point discharges, where the target material was carbon. 5 refs., 1 fig., 3 tabs.

  14. Study of acoustic emission due to vaporisation of superheated droplets at higher pressure

    Science.gov (United States)

    Sarkar, Rupa; Mondal, Prasanna Kumar; Chatterjee, Barun Kumar

    2017-08-01

    Bubble nucleation in superheated liquids can be controlled by adjusting the ambient pressure and temperature. At higher pressure the threshold energy for bubble nucleation increases, and we have observed that the amplitude of the acoustic emission during vaporisation of superheated droplet decreases with increase in pressure at any given temperature. Other acoustic parameters such as the primary harmonic frequency and the decay time constant of the acoustic signal also decrease with increase in pressure. This behavior is independent of the type of superheated liquid. The decrease in signal amplitude limits the detection of bubble nucleation at higher pressure. This effect is explained by the emission of shockwave generated during the supersonic growth of the microbubble in superheated liquids.

  15. Climate forcing and air quality change due to regional emissions reductions by economic sector

    Directory of Open Access Journals (Sweden)

    D. Shindell

    2008-06-01

    Full Text Available We examine the air quality (AQ and radiative forcing (RF response to emissions reductions by economic sector for North America and developing Asia in the CAM and GISS composition/climate models. Decreases in annual average surface particulate are relatively robust, with intermodel variations in magnitude typically <30% and very similar spatial structure. Surface ozone responses are small and highly model dependent. The largest net RF results from reductions in emissions from the North America industrial/power and developing Asia domestic fuel burning sectors. Sulfate reductions dominate the first case, for which intermodel variations in the sulfate (or total aerosol optical depth (AOD responses are ~30% and the modeled spatial patterns of the AOD reductions are highly correlated (R=0.9. Decreases in BC dominate the developing Asia domestic fuel burning case, and show substantially greater model-to-model differences. Intermodel variations in tropospheric ozone burdens are also large, though aerosol changes dominate those cases with substantial net climate forcing. The results indicate that across-the-board emissions reductions in domestic fuel burning in developing Asia and in surface transportation in North America are likely to offer the greatest potential for substantial, simultaneous improvement in local air quality and near-term mitigation of global climate change via short-lived species. Conversely, reductions in industrial/power emissions have the potential to accelerate near-term warming, though they would improve AQ and have a long-term cooling effect on climate. These broad conclusions appear robust to intermodel differences.

  16. The significance of nitrous oxide emission due to cropping of grain for biofuel production: a Swedish perspective

    Science.gov (United States)

    Kasimir Klemedtsson, Å.; Smith, K. A.

    2011-12-01

    The current regulations governing production of biofuels in the European Union require that they have to mitigate climate change, by producing >35% less greenhouse gases (GHG) than fossil fuels. There is a risk that this may not be achievable, since land use for crop production inevitably emits the potent GHG nitrous oxide (N2O), due to nitrogen fertilisation and cycling in the environment. We analyse first-generation biofuel production on agricultural land and conclude that efficient agricultural crop production resulting in a good harvest and low N2O emission can fulfil the EU standard, and is possible under certain conditions for the Swedish agricultural and bioethanol production systems. However, in years having low crop yields, and where cropping is on organic soils, total GHG emissions per unit of fuel produced can be even higher than those released by burning of fossil fuels. In general, the N2O emission size in Sweden and elsewhere in northern Europe is such that there is a >50% chance that the 35% saving requirement will not be met. Thus ecosystem N2O emissions have to be convincingly assessed. Here we compare Swedish emission data with values estimated by means of statistical models and by a global, top-down, approach; the measurements and the predictions often show higher values that would fail to meet the EU standard and thus prevent biofuel production development.

  17. Satellite-based estimates of reduced CO and CO2 emissions due to traffic restrictions during the 2008 Beijing Olympics

    Science.gov (United States)

    Worden, Helen M.; Cheng, Yafang; Pfister, Gabriele; Carmichael, Gregory R.; Zhang, Qiang; Streets, David G.; Deeter, Merritt; Edwards, David P.; Gille, John C.; Worden, John R.

    2012-07-01

    During the 2008 Olympics, the Chinese government made a significant effort to improve air quality in Beijing, including restrictions on traffic. Here we estimate the reductions in carbon monoxide (CO) and carbon dioxide (CO2) emissions resulting from the control measures on Beijing transportation. Using MOPITT (Measurements Of Pollution In The Troposphere) multispectral satellite observations of near-surface CO along with WRF-Chem (Weather Research and Forecasting model with Chemistry) simulations for Beijing during August, 2007 and 2008, we estimate changes in CO due to meteorology and transportation sector emissions. Applying a reported CO/CO2 emission ratio for fossil fuels, we find the corresponding reduction in CO2, 60 ± 36 Gg[CO2]/day. As compared to emission scenarios being considered for the IPCC AR5 (Intergovernmental Panel on Climate Change, 5th Assessment Report), this result suggests that urban traffic controls on the Beijing Olympics scale could play a significant role in meeting target reductions for global CO2 emissions.

  18. Contribution to Quality of Air Traffic Due to Reduction of Gaseous Emissions

    Directory of Open Access Journals (Sweden)

    Melichar Kopas

    2011-12-01

    Full Text Available There are described basic principles of jet engine construction and operation in the presented paper, taking into consideration question of gaseous emissions produced in exhaust gases of turbojet engines. The innovative aircraft jet engines are the most important power units of modern planes nowadays and therefore it is necessary to analyse their environmental impacts, with regard to quality of living environment. This paper integrates technical and environmental factors of up-to-date jet engines. It demonstrates an important fact that modern airplanes equipped by sophisticated turbo-jet engines are environment friendly with regard to reduced amount of pollutants in their exhaust gases.

  19. Changes in O3 and NO2 due to emissions from Fracking in the UK.

    Science.gov (United States)

    Archibald, Alexander; Ordonez, Carlos

    2016-04-01

    Poor air quality is a problem that affects millions of people around the world. Understanding the driving forces behind air pollution is complicated as the precursor gases which combine to produce air pollutants react in a highly non-linear manner and are subject to a range of atmospheric transport mechanisms compounded by the weather. A great deal of money has been spent on mitigating air pollution and so it's important to assess the impacts that new technologies that emit air pollutant precursors may have on local and regional air pollution. One of the most highly discussed new technologies that could impact air quality is the adoption of wide-scale hydraulic fracturing or "fracking" for natural gas. Indeed in regions of the USA where fracking is commonplace large levels of ozone (O3 - a key air pollutant) have been observed and attributed directly to the fracking process. In this study, a numerical modelling framework was used to assess possible impacts of fracking in the UK where at present no large scale fracking facilities are in operation. A number of emissions scenarios were developed for the principle gas phase air pollution precursors: the oxides of nitrogen (NOx) and volatile organic compounds (VOCs). These emissions scenarios were then used in a state-of-the-art numerical air quality model (the UK Met Office operational air quality forecasting model AQUM) to determine potential impacts related to fracking on UK air quality. Comparison of base model results and observations for the year 2013 of NOx, O3 and VOCs from the UK Automatic Urban and Rural Network (AURN) showed that AQUM has good skill at simulating these gas phase air pollutants (O3 r=0.64, NMGE=0.3; NO2 r=0.62, NMGE=0.51). Analysis of the simulations with fracking emissions demonstrate that there are large changes in 1hr max NO2 (11.6±6.6 ppb) with modest increases in monthly mean NO2, throughout the British Isles (150±100 ppt). These results highlight that stringent measures should be

  20. Chirped Auger electron emission due to field-assisted post-collision interaction

    Directory of Open Access Journals (Sweden)

    Bonitz M.

    2013-03-01

    Full Text Available We have investigated the Auger decay in the temporal domain by applying a terahertz streaking light field. Xenon and krypton atoms were studied by implementing the free-electron laser in Hamburg (FLASH as well as a source of high-order harmonic radiation combined with terahertz pulses from an optical rectification source. The observed linewidth asymmetries in the streaked spectra suggest a chirped Auger electron emission which is understood in terms of field-assisted post-collision interaction. The experimentally obtained results agree well with model calculations.

  1. Analysis Of The Infrared Emission Due To Aerodynamic Heating Of Missile Domes

    Science.gov (United States)

    Tofani, Alessandro

    1989-09-01

    A computer simulation of head-on infrared emission from missile noses has been performed. Both cruise missiles and tactical ballistic missiles were considered; results indicate a strong dependence of the emitted radiation on physical and geometrical properties of aerodynamic surfaces, flow character in the boundary layer and atmospheric characteristics. The model allows to give an order-of-magnitude estimate of radiant intensity in the 8-12 μm and 3-5 μm spectral bands and to determine their relative merits as far as the target detection is concerned.

  2. Smoke emissions due to burning of green waste in the Mediterranean area: Influence of fuel moisture content and fuel mass

    Science.gov (United States)

    Tihay-Felicelli, V.; Santoni, P. A.; Gerandi, G.; Barboni, T.

    2017-06-01

    The aim of this study was to investigate emission characteristics in relation to differences in fuel moisture content (FMC) and initial dry mass. For this purpose, branches and twigs with leaves of Cistus monspeliensis were burned in a Large Scale Heat Release apparatus coupled to a Fourier Transform Infrared Spectrometer. A smoke analysis was conducted and the results highlighted the presence of CO2, H2O, CO, CH4, NO, NO2, NH3, SO2, and non-methane organic compounds (NMOC). CO2, NO, and NO2 species are mainly released during flaming combustion, whereas CO, CH4, NH3, and NMOC are emitted during both flaming and smoldering combustion. The emission of these compounds during flaming combustion is due to a rich fuel to air mixture, leading to incomplete combustion. The fuel moisture content and initial dry mass influence the flame residence time, the duration of smoldering combustion, the combustion efficiency, and the emission factors. By increasing the initial dry mass, the emission factors of NO, NO2, and CO2 decrease, whereas those of CO and CH4 increase. The increase of FMC induces an increase of the emission factors of CO, CH4, NH3, NMOC, and aerosols, and a decrease of those of CO2, NO, and NO2. Increasing fuel moisture content reduces fuel consumption, duration of smoldering, and peak heat release rate, but simultaneously increases the duration of propagation within the packed bed, and the flame residence time. Increasing the initial dry mass, causes all the previous combustion parameters to increase. These findings have implications for modeling biomass burning emissions and impacts.

  3. Intensity enhancement of O VI ultraviolet emission lines in solar spectra due to opacity

    CERN Document Server

    Keenan, F P; Madjarska, M S; Rose, S J; Bowler, L A; Britton, J; McCrink, L; Mathioudakis, M

    2014-01-01

    Opacity is a property of many plasmas, and it is normally expected that if an emission line in a plasma becomes optically thick, its intensity ratio to that of another transition that remains optically thin should decrease. However, radiative transfer calculations undertaken both by ourselves and others predict that under certain conditions the intensity ratio of an optically thick to thin line can show an increase over the optically thin value, indicating an enhancement in the former. These conditions include the geometry of the emitting plasma and its orientation to the observer. A similar effect can take place between lines of differing optical depth. Previous observational studies have focused on stellar point sources, and here we investigate the spatially-resolved solar atmosphere using measurements of the I(1032 A)/I(1038 A) intensity ratio of O VI in several regions obtained with the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) instrument on board the Solar and Heliospheric Observatory (...

  4. Mapping the Polarization of the Radio-Loud lya Nebula B3 J2330+3927

    Science.gov (United States)

    You, Chang; Zabludoff, Ann; Smith, Paul; Yang, Yujin; Kim, Eunchong; Jannuzi, Buell; Prescott, Moire K. M.; Matsuda, Yuichi; Lee, Myung Gyoon

    2017-01-01

    Lyα nebulae, or “Lyα blobs,” are extended (up to ∼100 kpc), bright (LLyα ≳ 1043 erg s‑1) clouds of Lyα emitting gas that tend to lie in overdense regions at z ∼ 2–5. The origin of the Lyα emission remains unknown, but recent theoretical work suggests that measuring the polarization might discriminate among powering mechanisms. Here we present the first narrowband imaging polarimetry of a radio-loud Lyα nebula, B3 J2330+3927, at z = 3.09, with an embedded active galactic nucleus (AGN). The AGN lies near the blob’s Lyα emission peak, and its radio lobes align roughly with the blob’s major axis. With the SPOL polarimeter on the 6.5 m MMT telescope, we map the total (Lyα + continuum) polarization in a grid of circular apertures of a radius of 0.″6 (4.4 kpc), detecting a significant (>2σ) polarization fraction P% in nine apertures and achieving strong upper limits (as low as 2%) elsewhere. P% increases from <2% at ∼5 kpc from the blob center to 17% at ∼15–25 kpc. The detections are distributed asymmetrically, roughly along the nebula’s major axis. The polarization angles θ are mostly perpendicular to this axis. Comparing the Lyα flux to that of the continuum and conservatively assuming that the continuum is highly polarized (20%–100%) and aligned with the total polarization, we place lower limits on the polarization of the Lyα emission P%,Lyα ranging from no significant polarization at ∼5 kpc from the blob center to 3%–17% at 10–25 kpc. Like the total polarization, the Lyα polarization detections occur more often along the blob’s major axis. The observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution.

  5. Environmental Impact Analysis of Acidification and Eutrophication Due to Emissions from the Production of Concrete

    Directory of Open Access Journals (Sweden)

    Tae Hyoung Kim

    2016-06-01

    Full Text Available Concrete is a major material used in the construction industry that emits a large amount of substances with environmental impacts during its life cycle. Accordingly, technologies for the reduction in and assessment of the environmental impact of concrete from the perspective of a life cycle assessment (LCA must be developed. At present, the studies on LCA in relation to greenhouse gas emission from concrete are being carried out globally as a countermeasure against climate change. However, the studies on the impact of the substances emitted in the concrete production process on acidification and eutrophication are insufficient. As such, assessing only a single category of environmental impact may cause a misunderstanding about the environmental friendliness of concrete. The substances emitted in the concrete production process have an impact not only on global warming but also on acidification and eutrophication. Acidification and eutrophication are the main causes of air pollution, forest destruction, red tide phenomena, and deterioration of reinforced concrete structures. For this reason, the main substances among those emitted in the concrete production process that have an impact on acidification and eutrophication were deduced. In addition, an LCA technique through which to determine the major emissions from concrete was proposed and a case analysis was carried out. The substances among those emitted in the concrete production process that are related to eutrophication were deduced to be NOx, NH3, NH4+, COD, NO3−, and PO43−. The substances among those emitted in the concrete production process that are related to acidification, were found to be NOx, SO2, H2S, and H2SO4. The materials and energy sources among those input into the concrete production process, which have the biggest impact on acidification and eutrophication, were found to be coarse aggregate and fine aggregate.

  6. Broad Ly alpha Emission from Three Nearby BL Lacertae Objects

    CERN Document Server

    Stocke, John T; Perlman, Eric S

    2011-01-01

    We present far-UV HST/COS spectra of four nearby BL Lac Objects. BL Lac spectra are dominated by a smooth, power-law continuum which arises in a relativistic jet. However, the spectra are not necessarily featureless; weak, broad- and/or narrow-line emission is sometimes seen in high-quality optical spectra. We present detections of Lya emission in HST/COS spectra of Mrk421 (z=0.030) and PKS2005-489 (z=0.071) as well as an archival HST/GHRS observation of Mrk501 (z=0.0337). Archival HST/STIS observations of PKS2155-304 (z=0.116) show no Lya emission to a very low upper limit. Using the assumption that the broad-line region (BLR) clouds are asymmetrically placed around the AGN, we use these measured Lya emission features to constrain either the relativistic Gamma values for the ionizing continuum produced by the jet (in the ionization-bounded case) or the mass of warm gas (in the density-bounded case). While realistic Gamma values can be obtained for all four cases, the values for Mrk421 and PKS2155-304 are hig...

  7. Energy efficient measures to reduce PM2,5 emissions due to cooking

    NARCIS (Netherlands)

    Jacobs, P.; Cornelissen, H.J.M.; Borsboom, W.A.

    2016-01-01

    Laboratory tests with heating olive oil in kitchens suggest that the current building regulation in the Netherlands for kitchen exhaust is inadequate to directly address cooking fumes. Due to building traditions, for motor less cooker hoods often only 50% of the available capacity of the mechanical

  8. Impacts of decadal variations in natural emissions due to land-cover changes on ozone production in southern China

    Directory of Open Access Journals (Sweden)

    Mengmeng Li

    2015-09-01

    Full Text Available The decadal variations in emissions of high-reactivity biogenic volatile organics (BVOCs, as a result of land-cover changes, could significantly impact ozone (O3 production. In this study, the Weather Research and Forecasting/Chemistry (WRF/Chem modelling system, coupled with dynamic vegetation data sets derived from Moderate Resolution Imaging Spectroradiometer (MODIS, 2001–2012 and Advanced Very High Resolution Radiometer (AVHRR, early 1990s measurements, were used to investigate the impacts of land-cover changes on natural emissions, and consequently O3 production, in the Pearl River Delta (PRD region of southern China over the past two decades. Model results indicate that BVOC emissions were highly dependent on forest area. The total BVOC emissions in the modelling domain increased by a factor of two due to afforestation since the early 1990s, declined slowly (−5.8% yr−1 until 2006 and then increased continuously (+9.1% yr−1 to 2012. The decadal variations in BVOC emissions have complex implications for summer O3 production in PRD, depending on the chemical regimes and prevailing winds. The impacts on O3 production were most sensitive in downwind areas, and it was found that the large increase in BVOC emissions during 2006–2012 tended to reduce surface O3 concentrations by 1.6–2.5 ppb in rural regions, but caused an increment of O3 peaks by up to 2.0–6.0 ppb in VOC-limited urban areas (e.g., Guangzhou, Foshan and Zhongshan. The opposite was true in the period 2001–2006, when the reduced BVOC emissions resulted in 1.3–4.0 ppb increases in daytime O3 concentrations over northern rural regions. Impact of the two-fold increase in BVOC emissions since the early 1990s to 2006 was a 0.9–4.6 ppb increment in surface O3 concentrations over the downwind areas. This study suggests that the potential impacts on ozone chemistry should be considered in long-term land-use planning and air-quality management.

  9. Fluorogens with Aggregation Induced Emission: Ideal Photoacoustic Contrast Reagents Due to Intramolecular Rotation.

    Science.gov (United States)

    Geng, Junlong; Liao, Lun-De; Qin, Wei; Tang, Ben Zhong; Thakor, Nitish; Liu, Bin

    2015-02-01

    Exogenous contrast agents with high sensitivity are highly desirable for photoacoustic (PA) imaging. In this work, we show that fluorogens with aggregation induced emission (AIE) characteristics are born with strong PA signals. In addition, we find that the PA signal of conventional fluorophores could be significantly enhanced through conjugation with tetraphenylethene (TPE), an iconic AIE fluorogen. Taking 2,3-bis[4-(diphenylamino)phenyl]fumaronitrile (TPAFN) as an example, conjugation between TPAFN and TPE affords 2,3-bis(4-(phenyl(4-(1,2,2-triphenylvinyl)phenyl)amino)phenyl) fumaroni-trile (TPETPAFN), a molecule with significant AIE characteristics, which shows 170% higher PA signals as compared to that of TPAFN. The higher PA signal of TPETPAFN is mainly ascribed to the enhanced molecular rotation, which is beneficial to its thermal expansion upon light absorption. Moreover, the significantly reduced PA signals for TPETPAFN in solvents with high viscosity or as nanoparticles further highlight the contribution of molecular rotation on PA signals.

  10. Global alteration of ocean ecosystem functioning due to increasing human CO2 emissions.

    Science.gov (United States)

    Nagelkerken, Ivan; Connell, Sean D

    2015-10-27

    Rising anthropogenic CO2 emissions are anticipated to drive change to ocean ecosystems, but a conceptualization of biological change derived from quantitative analyses is lacking. Derived from multiple ecosystems and latitudes, our metaanalysis of 632 published experiments quantified the direction and magnitude of ecological change resulting from ocean acidification and warming to conceptualize broadly based change. Primary production by temperate noncalcifying plankton increases with elevated temperature and CO2, whereas tropical plankton decreases productivity because of acidification. Temperature increases consumption by and metabolic rates of herbivores, but this response does not translate into greater secondary production, which instead decreases with acidification in calcifying and noncalcifying species. This effect creates a mismatch with carnivores whose metabolic and foraging costs increase with temperature. Species diversity and abundances of tropical as well as temperate species decline with acidification, with shifts favoring novel community compositions dominated by noncalcifiers and microorganisms. Both warming and acidification instigate reduced calcification in tropical and temperate reef-building species. Acidification leads to a decline in dimethylsulfide production by ocean plankton, which as a climate gas, contributes to cloud formation and maintenance of the Earth's heat budget. Analysis of responses in short- and long-term experiments and of studies at natural CO2 vents reveals little evidence of acclimation to acidification or temperature changes, except for microbes. This conceptualization of change across whole communities and their trophic linkages forecast a reduction in diversity and abundances of various key species that underpin current functioning of marine ecosystems.

  11. Revising the Local Bubble Model due to Solar Wind Charge Exchange X-ray Emission

    CERN Document Server

    Shelton, Robin L

    2008-01-01

    The hot Local Bubble surrounding the solar neighborhood has been primarily studied through observations of its soft X-ray emission. The measurements were obtained by attributing all of the observed local soft X-rays to the bubble. However, mounting evidence shows that the heliosphere also produces diffuse X-rays. The source is solar wind ions that have received an electron from another atom. The presence of this alternate explanation for locally produced diffuse X-rays calls into question the existence and character of the Local Bubble. This article addresses these questions. It reviews the literature on solar wind charge exchange (SWCX) X-ray production, finding that SWCX accounts for roughly half of the observed local 1/4 keV X-rays found at low latitudes. This article also makes predictions for the heliospheric O VI column density and intensity, finding them to be smaller than the observational error bars. Evidence for the continued belief that the Local Bubble contains hot gas includes the remaining local...

  12. The Impact of Individual Anthropogenic Emissions Sectors on the Global Burden of Human Mortality due to Ambient Air Pollution.

    Science.gov (United States)

    Silva, Raquel A; Adelman, Zachariah; Fry, Meridith M; West, J Jason

    2016-11-01

    Exposure to ozone and fine particulate matter (PM2.5) can cause adverse health effects, including premature mortality due to cardiopulmonary diseases and lung cancer. Recent studies quantify global air pollution mortality but not the contribution of different emissions sectors, or they focus on a specific sector. We estimated the global mortality burden of anthropogenic ozone and PM2.5, and the impact of five emissions sectors, using a global chemical transport model at a finer horizontal resolution (0.67° × 0.5°) than previous studies. We performed simulations for 2005 using the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4), zeroing out all anthropogenic emissions and emissions from specific sectors (All Transportation, Land Transportation, Energy, Industry, and Residential and Commercial). We estimated premature mortality using a log-linear concentration-response function for ozone and an integrated exposure-response model for PM2.5. We estimated 2.23 (95% CI: 1.04, 3.33) million deaths/year related to anthropogenic PM2.5, with the highest mortality in East Asia (48%). The Residential and Commercial sector had the greatest impact globally-675 (95% CI: 428, 899) thousand deaths/year-and in most regions. Land Transportation dominated in North America (32% of total anthropogenic PM2.5 mortality), and it had nearly the same impact (24%) as Residential and Commercial (27%) in Europe. Anthropogenic ozone was associated with 493 (95% CI: 122, 989) thousand deaths/year, with the Land Transportation sector having the greatest impact globally (16%). The contributions of emissions sectors to ambient air pollution-related mortality differ among regions, suggesting region-specific air pollution control strategies. Global sector-specific actions targeting Land Transportation (ozone) and Residential and Commercial (PM2.5) sectors would particularly benefit human health. Citation: Silva RA, Adelman Z, Fry MM, West JJ. 2016. The impact of individual

  13. The Impact of Individual Anthropogenic Emissions Sectors on the Global Burden of Human Mortality due to Ambient Air Pollution

    Science.gov (United States)

    Silva, Raquel A.; Adelman, Zachariah; Fry, Meridith M.; West, J. Jason

    2016-01-01

    Background: Exposure to ozone and fine particulate matter (PM2.5) can cause adverse health effects, including premature mortality due to cardiopulmonary diseases and lung cancer. Recent studies quantify global air pollution mortality but not the contribution of different emissions sectors, or they focus on a specific sector. Objectives: We estimated the global mortality burden of anthropogenic ozone and PM2.5, and the impact of five emissions sectors, using a global chemical transport model at a finer horizontal resolution (0.67° × 0.5°) than previous studies. Methods: We performed simulations for 2005 using the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4), zeroing out all anthropogenic emissions and emissions from specific sectors (All Transportation, Land Transportation, Energy, Industry, and Residential and Commercial). We estimated premature mortality using a log-linear concentration–response function for ozone and an integrated exposure–response model for PM2.5. Results: We estimated 2.23 (95% CI: 1.04, 3.33) million deaths/year related to anthropogenic PM2.5, with the highest mortality in East Asia (48%). The Residential and Commercial sector had the greatest impact globally—675 (95% CI: 428, 899) thousand deaths/year—and in most regions. Land Transportation dominated in North America (32% of total anthropogenic PM2.5 mortality), and it had nearly the same impact (24%) as Residential and Commercial (27%) in Europe. Anthropogenic ozone was associated with 493 (95% CI: 122, 989) thousand deaths/year, with the Land Transportation sector having the greatest impact globally (16%). Conclusions: The contributions of emissions sectors to ambient air pollution–related mortality differ among regions, suggesting region-specific air pollution control strategies. Global sector-specific actions targeting Land Transportation (ozone) and Residential and Commercial (PM2.5) sectors would particularly benefit human health. Citation: Silva RA

  14. Properties of Lya Emitters Around the Radio Galaxy MRC 0316-257

    Energy Technology Data Exchange (ETDEWEB)

    Venemans, B; Rottgering, H; Miley, G; Kurk, J; De Breuck, C; van Breugel, W; Carilli, C; Ford, H; Heckman, T; Pentericci, L; McCarthy, P

    2004-08-12

    Observations of the radio galaxy MRC 0316-257 at z = 3.13 and the surrounding field are presented. Using narrow- and broad-band imaging obtained with the VLT*, 92 candidate Ly{alpha} emitters with a rest-frame equivalent width of > 15 AngstromS were selected in a {approx} 7{prime} x 7{prime} field around the radio galaxy. Spectroscopy of 40 candidate emitters resulted in the discovery of 33 emission line galaxies of which 31 are Ly{alpha} emitters with redshifts similar to that of the radio galaxy, while the remaining two galaxies turned out to be [{omicron} II] emitters. The Ly{alpha} profiles had widths (FWHM) corresponding to 120-800 kms{sup -1},with a median of 260 kms{sup -1}. Where the signal-to-noise spectra was large enough, the Ly{alpha} profiles are found to be asymmetric, with apparent absorption troughs blueward of the profile peaks, indicative of absorption along the line of sight of an {Eta}{Iota} mass of 1-5000 {mu}{circle_dot}. Besides that of the radio galaxy and one of the emitters that is an QSO, the continuum of the emitters is faint, with luminosities ranging from 1.3 L{sub *} to < 0.03 L{sub *}.The colors of the confirmed emitters are, on average, very blue. The median UV continuum slope is {beta}=-1.65, bluer than the average slope of LBGs with Ly{alpha} emitters is 2.6 {Mu}{circle_dot}{sup -1} as measured by the Ly{alpha} emission line or < 3.9 {Mu}{circle_dot}{sup -1} as measured by the UV continuum. The properties of the Ly{alpha} galaxies (faint, blue and small) are consistent with young star forming galaxies which are nearly dust free. The density of Ly{alpha} emitting galaxies in the field around MRC 0316-257 is a factor of 3.3{sup +0.5}{sub -0.4} larger compared with the density of Ly{alpha} emitters at that redshift. The velocity distribution of the spectroscopically confirmed emitters has a dispersion of 640 km s{sup -1}, corresponding to a FWHM of 1510 km s{sup -1}, which is substantially smaller than the width of the narrow

  15. Contraction of westward-travelling nonlocal modons due to the vorticity filament emission

    Directory of Open Access Journals (Sweden)

    D. Berson

    2002-01-01

    Full Text Available Long-term evolution of westward-travelling non-local modons on the β-plane, i.e. dipolar vortices imbedded in slowly damping Rossby wave fields, is studied numerically. In the framework of the nondivergent (barotropic model, two stages of the evolution are observed. At the first stage (for about 30 synoptic periods, the parameters and the form of the vortex practically remain constant, whereas at the second stage, vorticity filaments are emitted. Due to the filamentation, the vortex core contracts, the potential vorticity peaks of the vortex pair get closer, and the modon speeds up. In the divergent (equivalent-barotropic model, nonlocal modons and the Lamb modon (that has no wave field outside the dipolar core evolve much more slowly, essentially preserving the initial shape and propagation speed until about 100 synoptic periods.

  16. OMI-measured increasing SO2 emissions due to energy industry expansion and relocation in northwestern China

    Science.gov (United States)

    Ling, Zaili; Huang, Tao; Zhao, Yuan; Li, Jixiang; Zhang, Xiaodong; Wang, Jinxiang; Lian, Lulu; Mao, Xiaoxuan; Gao, Hong; Ma, Jianmin

    2017-07-01

    The rapid growth of economy makes China the largest energy consumer and sulfur dioxide (SO2) emitter in the world. In this study, we estimated the trends and step changes in the planetary boundary layer (PBL) vertical column density (VCD) of SO2 from 2005 to 2015 over China measured by the Ozone Monitoring Instrument (OMI). We show that these trends and step change years coincide with the effective date and period of the national strategy for energy development and relocation in northwestern China and the regulations in the reduction of SO2 emissions. Under the national regulations for the reduction of SO2 emissions in eastern and southern China, SO2 VCD in the Pearl River Delta (PRD) of southern China exhibited the largest decline during 2005-2015 at a rate of -7 % yr-1, followed by the North China Plain (NCP) (-6.7 % yr-1), Sichuan Basin (-6.3 % yr-1), and Yangtze River Delta (YRD) (-6 % yr-1). The Mann-Kendall (MK) test reveals the step change points of declining SO2 VCD in 2009 for the PRD and 2012-2013 for eastern China responding to the implementation of SO2 control regulation in these regions. In contrast, the MK test and regression analysis also revealed increasing trends of SO2 VCD in northwestern China, particularly for several hot spots featured by growing SO2 VCD in those large-scale energy industry bases in northwestern China. The enhanced SO2 VCD is potentially attributable to increasing SO2 emissions due to the development of large-scale energy industry bases in energy-abundant northwestern China under the national strategy for the energy safety of China in the 21st century. We show that these large-scale energy industry bases could overwhelm the trends and changes in provincial total SO2 emissions in northwestern China and contribute increasingly to the national total SO2 emissions in China. Given that northwestern China is more ecologically fragile and uniquely susceptible to atmospheric pollution than the rest of China, increasing SO2 emissions in

  17. The Far-Ultraviolet "Continuum" in Protoplanetary Disk Systems II: CO Fourth Positive Emission and Absorption

    CERN Document Server

    France, Kevin; Burgh, Eric B; Herczeg, Gregory J; Harper, Graham M; Brown, Alexander; Green, James C; Linsky, Jeffrey L; Yang, Hao; Abgrall, Hervé; Ardila, David R; Bergin, Edwin; Bethell, Thomas; Brown, Joanna M; Calvet, Nuria; Espaillat, Catherine; Gregory, Scott G; Hillenbrand, Lynne A; Hussain, Gaitee; Ingleby, Laura; Johns-Krull, Christopher M; Roueff, Evelyne; Valenti, Jeff A; Walter, Frederick M

    2011-01-01

    We exploit the high sensitivity and moderate spectral resolution of the $HST$-Cosmic Origins Spectrograph to detect far-ultraviolet spectral features of carbon monoxide (CO) present in the inner regions of protoplanetary disks for the first time. We present spectra of the classical T Tauri stars HN Tau, RECX-11, and V4046 Sgr, representative of a range of CO radiative processes. HN Tau shows CO bands in absorption against the accretion continuum. We measure a CO column density and rotational excitation temperature of N(CO) = 2 +/- 1 $\\times$ 10$^{17}$ cm$^{-2}$ and T_rot(CO) 500 +/- 200 K for the absorbing gas. We also detect CO A-X band emission in RECX-11 and V4046 Sgr, excited by ultraviolet line photons, predominantly HI LyA. All three objects show emission from CO bands at $\\lambda$ $>$ 1560 \\AA, which may be excited by a combination of UV photons and collisions with non-thermal electrons. In previous observations these emission processes were not accounted for due to blending with emission from the accr...

  18. Discovery of a Damped Lya Absorber at z = 3.3 along a galaxy sight-line in the SSA22 field

    CERN Document Server

    Mawatari, K; Kousai, K; Hayashino, T; Cooke, R; Prochaska, J X; Yamada, T; Matsuda, Y

    2015-01-01

    Using galaxies as background light sources to map the Lya absorption lines is a novel approach to study Damped Lya Absorbers (DLAs). We report the discovery of an intervening z = 3.335 +- 0.007 DLA along a galaxy sight-line identified among 80 Lyman Break Galaxy (LBG) spectra obtained with our VLT/VIMOS survey in the SSA22 field. The measured DLA neutral hydrogen (HI) column density is log (NHI/cm^{-2}) = 21.68 +- 0.17. The DLA covering fraction over the extended background LBG is > 70 % (2 sigma), yielding a conservative constraint on the DLA area as > 1 kpc^2. Our search for a counterpart galaxy hosting this DLA concludes that there is no counterpart galaxy with star formation rate (SFR) larger than a few Msun yr^{-1}, ruling out an unobscured violent star formation in the DLA gas cloud. We also rule out the possibility that the host galaxy of the DLA is a passive galaxy with Mstar > 5 x 10^{10} Msun or a heavily dust-obscured galaxy with E(B-V) > 2. The DLA may coincide in a large-scale overdensity of the ...

  19. MODELING THE ANOMALY OF SURFACE NUMBER DENSITIES OF GALAXIES ON THE GALACTIC EXTINCTION MAP DUE TO THEIR FIR EMISSION CONTAMINATION

    Energy Technology Data Exchange (ETDEWEB)

    Kashiwagi, Toshiya; Suto, Yasushi; Taruya, Atsushi; Yahata, Kazuhiro [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Kayo, Issha [Department of Physics, Toho University, Funabashi, Chiba 274-8510 (Japan); Nishimichi, Takahiro, E-mail: kashiwagi@utap.phys.s.u-tokyo.ac.jp [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan)

    2015-02-01

    The most widely used Galactic extinction map is constructed assuming that the observed far-infrared (FIR) fluxes come entirely from Galactic dust. According to the earlier suggestion by Yahata et al., we consider how FIR emission of galaxies affects the SFD map. We first compute the surface number density of Sloan Digital Sky Survey (SDSS) DR7 galaxies as a function of the r-band extinction, A {sub r,} {sub SFD}. We confirm that the surface densities of those galaxies positively correlate with A {sub r,} {sub SFD} for A {sub r,} {sub SFD} < 0.1, as first discovered by Yahata et al. for SDSS DR4 galaxies. Next we construct an analytical model to compute the surface density of galaxies, taking into account the contamination of their FIR emission. We adopt a log-normal probability distribution for the ratio of 100 μm and r-band luminosities of each galaxy, y ≡ (νL){sub 100} {sub μm}/(νL) {sub r}. Then we search for the mean and rms values of y that fit the observed anomaly, using the analytical model. The required values to reproduce the anomaly are roughly consistent with those measured from the stacking analysis of SDSS galaxies. Due to the limitation of our statistical modeling, we are not yet able to remove the FIR contamination of galaxies from the extinction map. Nevertheless, the agreement with the model prediction suggests that the FIR emission of galaxies is mainly responsible for the observed anomaly. Whereas the corresponding systematic error in the Galactic extinction map is 0.1-1 mmag, it is directly correlated with galaxy clustering and thus needs to be carefully examined in precision cosmology.

  20. Mobile load simulators - A tool to distinguish between the emissions due to abrasion and resuspension of PM10 from road surfaces

    Science.gov (United States)

    Gehrig, R.; Zeyer, K.; Bukowiecki, N.; Lienemann, P.; Poulikakos, L. D.; Furger, M.; Buchmann, B.

    2010-12-01

    Mechanically produced abrasion particles and resuspension processes are responsible for a significant part of the PM10 emissions of road traffic. However, specific differentiation between PM10 emissions due to abrasion and resuspension from road pavement is very difficult due to their similar elemental composition and highly correlated variation in time. In this work Mobile Load Simulators were used to estimate PM10 emission factors for pavement abrasion and resuspension on different pavement types for light and heavy duty vehicles. From the experiments it was derived that particle emissions due to abrasion from pavements in good condition are quite low in the range of only a few mg·km -1 per vehicle if quantifiable at all. Considerable abrasion emissions, however, can occur from damaged pavements. Resuspension of deposited dust can cause high and extremely variable particle emissions depending strongly on the dirt load of the road surface. Porous pavements seem to retain deposited dust better than dense pavements, thus leading to lower emissions due to resuspension compared to pavements with a dense structure (e.g. asphalt concrete). Tyre wear seemed not to be a quantitatively significant source of PM10 emissions from road traffic.

  1. Environmental Particle Emissions due to Automated Drilling of Polypropylene Composites and Nanocomposites Reinforced with Talc, Montmorillonite and Wollastonite

    Science.gov (United States)

    Starost, K.; Frijns, E.; Laer, J. V.; Faisal, N.; Egizabal, A.; Elizextea, C.; Nelissen, I.; Blazquez, M.; Njuguna, J.

    2017-05-01

    In this study, the effect on nanoparticle emissions due to drilling on Polypropylene (PP) reinforced with 20% talc, 5% montmorillonite (MMT) and 5% Wollastonite (WO) is investigated. The study is the first to explore the nanoparticle release from WO and talc reinforced composites and compares the results to previously researched MMT. With 5% WO, equivalent tensile properties with a 10 % weight reduction were obtained relative to the reference 20% talc sample. The materials were fabricated through injection moulding. The nanorelease studies were undertaken using the controlled drilling methodology for nanoparticle exposure assessment developed within the European Commission funded SIRENA Life 11 ENV/ES/506 project. Measurements were taken using CPC and DMS50 equipment for real-time characterization and measurements. The particle number concentration (of particles talc sample emitted larger particle diameters.

  2. Likota lya bankoya

    NARCIS (Netherlands)

    Shimunika, Johasaphat Malasha; Binsbergen, Wim van

    1988-01-01

    This text of "The history of the Nkoya people" keeps as closely as possible to the original manuscript as written in the 1950s-1960s. (An English translation is included as part 3 in Wim van Binsbergen's 'Tears of rain: ethnicity and history in central western Zambia', published in London in 1992 by

  3. Enhanced formation of secondary air pollutants and aggravation of urban smog due to crop residue burning emissions in North India

    Science.gov (United States)

    Sarkar, Chinmoy; Kumar, Vinod; Sinha, Vinayak

    2013-04-01

    Biomass burning causes intense perturbations to regional atmospheric chemistry and air quality and is a significant global source of reactive pollutants to the atmosphere (Andreae and Merlet, 2001). In November 2012, large areas in North India including New Delhi experienced several weeks of aggravated smog and poor air quality due to the impact of crop residue burning, which is a biannual post harvest activity that occurs during Oct-Nov and April-May every year in the agricultural belts of North western India. In-situ high temporal resolution (1 measurement every minute) measurements of a suite of volatile organic compounds measured using proton transfer reaction mass spectrometry (PTR-MS) such as acetonitrile (biomass burning tracer) and aromatic hydrocarbons were performed simultaneously with carbon monoxide, nitrogen oxides, ozone and aerosol mass concentrations (PM 2.5 and PM 10) at a suburban site (30.667°N, 76.729°E and 310 m asl), impacted by air masses that had passed over the burning fields less than 72 hours ago. By using data from the same season but before the post harvest crop residue burning activity had commenced, we were able to quantify enhancements in ambient levels of the measured species due to the crop residue burning activity. When air masses influenced by the fire emissions reached the measurement site, peak values of about 8 ppbV acetonitrile, 4 ppmV CO, 100 ppbV NOx , 30 ppbV toluene and 15 ppbV benzene were observed which represented a factor of 2-5 increase over their ambient levels in the non-fire influenced period. Emission ratios of aromatic hydrocarbons/CO also showed a marked increase. Non fire event (N.F. E.) influenced and fire event (F.E.) influenced air masses had the following emission ratio enhancements: benzene/CO (N.F.E = 3; F.E. = 5), toluene/CO (N.F.E = 4; F.E. = 8.7) and sum of C8 aromatics/CO (N.F.E = 4; F.E. = 7.3) and sum of C9 aromatics/CO (N.F.E = 2.6; F.E. = 3.4). The OH reactivity of air masses which has strong

  4. Ahi Community as an Educational Institution and “Marks of Ahi Community Culture on Today’s Bursa Craftsman” by Hülya Taş / Kitap Tanıtım ve Değerlendirme: Bir Eğitim Kurumu Olarak Ahilik ve Hülya Taş’ın “Günümüz Bursa Esnafında Ahilik Kültüründen İzler”Adlı Eseri

    Directory of Open Access Journals (Sweden)

    Sıddık BAKIR

    2014-03-01

    Full Text Available This article is about Ahi community comprising of moral, religious, social and cultural values; the relationship between Ahi community and education; the presentation of the study named“Marks of Ahi Community on Today’s Bursa Craftsman”written by Hülya TAŞ in essence. In addition, the article gives publicity to the autobiography of Hülya TAŞ who has done successful studies aboutTurkish folklore and Ahi community and her academic studies. Bu makale esas itibariyle ahlaki, dinî, sosyal ve kültürel değerler bütünü olan ahilik teşkilatını, ahilik teşkilatının eğitim ile ilişkisini ve Hülya TAŞ tarafından hazırlanan “Günümüz Bursa Esnafında Ahilik Kültüründen İzler” adlı eserin tanıtımını konu almaktadır. Makalede ayrıca Türk halk bilimi ve ahilikle ilgili başarılı çalışmalar yapan Hülya TAŞ’ın öz geçmişine ve akademik çalışmalarına da yer verilmektedir.

  5. A Nano-satellite Mission to Study Charged Particle Precipitation from the Van Allen Radiation Belts caused due to Seismo-Electromagnetic Emissions

    CERN Document Server

    Sivadas, Nithin; Kannapan, Deepti; Yalamarthy, Ananth Saran; Dhiman, Ankit; Bhagoji, Arjun; Shankar, Athreya; Prasad, Nitin; Ramachandran, Harishankar; Koilpillai, R David

    2014-01-01

    In the past decade, several attempts have been made to study the effects of seismo-electromagnetic emissions - an earthquake precursor, on the ionosphere and the radiation belts. The IIT Madras nano-satellite (IITMSAT) mission is designed to make sensitive measurements of charged particle fluxes in a Low Earth Orbit to study the nature of charged particle precipitation from the Van Allen radiation belts caused due to such emissions. With the Space-based Proton Electron Energy Detector on-board a single nano-satellite, the mission will attempt to gather statistically significant data to verify possible correlations with seismo-electromagnetic emissions before major earthquakes.

  6. Uncertainty in the Future Distribution of Tropospheric Ozone over West Africa due to Variability in Anthropogenic Emissions Estimates between 2025 and 2050

    Directory of Open Access Journals (Sweden)

    J. E. Williams

    2011-01-01

    Full Text Available Particle and trace gas emissions due to anthropogenic activity are expected to increase significantly in West Africa over the next few decades due to rising population and more energy intensive lifestyles. Here we perform 3D global chemistry-transport model calculations for 2025 and 2050 using both a “business-as-usual” (A1B and “clean economy” (B1 future anthropogenic emission scenario to focus on the changes in the distribution and uncertainties associated with tropospheric O3 due to the various projected emission scenarios. When compared to the present-day troposphere we find that there are significant increases in tropospheric O3 for the A1B emission scenario, with the largest increases being located in the lower troposphere near the source regions and into the Sahel around 15–20°N. In part this increase is due to more efficient NOx re-cycling related to increases in the background methane concentrations. Examining the uncertainty across different emission inventories reveals that there is an associated uncertainty of up to ~20% in the predicted increases at 2025 and 2050. For the upper troposphere, where increases in O3 have a more pronounced impact on radiative forcing, the uncertainty is influenced by transport of O3 rich air from Asia on the Tropical Easterly Jet.

  7. Future Projections of Aerosol Optical Depth, Radiative Forcing, and Climate Response Due to Declining Aerosol Emissions in the Representative Concentration Pathways

    Science.gov (United States)

    Westervelt, D. M.; Mauzerall, D. L.; Horowitz, L. W.; Naik, V.

    2014-12-01

    It is widely expected that global emissions of atmospheric aerosols and their precursors will decrease strongly throughout the remainder of the 21st century, due to emission reduction policies enacted based on human health concerns. However, the resulting decrease in atmospheric aerosol burden will have unintended climate consequences. Since aerosols generally exert a net cooling influence on the climate, their removal will lead to an unmasking of global warming as well as other changes to the climate system. Aerosol and precursor global emissions decrease by as much as 80% by the year 2100, according to projections in four Representative Concentration Pathway (RCP) scenarios. We use the Geophysical Fluid Dynamics Laboratory Climate Model version 3 (GFDL CM3) to simulate future climate over the 21st century with and without aerosol emission changes projected by the RCPs in order to isolate the radiative forcing and climate response due to the aerosol reductions. We find that up to 1 W m-2 of radiative forcing may be unmasked globally by 2100 due to reductions in aerosol and precursor emissions, leading to average global temperature increases up to 1 K and global precipitation rate increases up to 0.09 mm d-1 (3%). Regionally and locally, climate impacts are much larger, as RCP8.5 projects a 2.1 K warming over China, Japan, and Korea due to reduced aerosol emissions. Our results highlight the importance of crafting emissions control policies with both climate and air pollution benefits in mind. The expected unmasking of additional global warming from aerosol reductions highlights the importance of robust greenhouse gas mitigation policies and may require more aggressive policies than anticipated.

  8. Carbon emissions due to deforestation for the production of charcoal used in Brazil’s steel industry

    Science.gov (United States)

    Sonter, Laura J.; Barrett, Damian J.; Moran, Chris J.; Soares-Filho, Britaldo S.

    2015-04-01

    Steel produced using coal generates 7% of global anthropogenic CO2 emissions annually. Opportunities exist to substitute this coal with carbon-neutral charcoal sourced from plantation forests to mitigate project-scale emissions and obtain certified emission reduction credits under the Kyoto Protocol’s Clean Development Mechanism. This mitigation strategy has been implemented in Brazil and is one mechanism among many used globally to reduce anthropogenic CO2 emissions; however, its potential adverse impacts have been overlooked to date. Here, we report that total CO2 emitted from Brazilian steel production doubled (91 to 182 MtCO2) and specific emissions increased (3.3 to 5.2 MtCO2 per Mt steel) between 2000 and 2007, even though the proportion of coal used declined. Infrastructure upgrades and a national plantation shortage increased industry reliance on charcoal sourced from native forests, which emits up to nine times more CO2 per tonne of steel than coal. Preventing use of native forest charcoal could have avoided 79% of the CO2 emitted from steel production between 2000 and 2007; however, doing so by increasing plantation charcoal supply is limited by socio-economic costs and risks further indirect deforestation pressures and emissions. Effective climate change mitigation in Brazil’s steel industry must therefore minimize all direct and indirect carbon emissions generated from steel manufacture.

  9. Emissions balancing of renewable energy sources. Avoided emissions due to the use of renewable energies in 2007; Emissionsbilanz erneuerbarer Energietraeger. Durch Einsatz erneuerbarer Energien vermiedene Emissionen im Jahr 2007

    Energy Technology Data Exchange (ETDEWEB)

    Memmler, Michael; Mohrbach, Elke; Schneider, Sven; Dreher, Marion; Herbener, Reinhard

    2009-10-15

    The report on the emissions accounting with respect to renewable energy covers the following issues: 1. Introduction and purpose. 2. Methodology concerning the balancing for electricity, heat and traffic, uncertainties due to lack of data. 3. Energy supply from renewable energy sources in 2007. 4. Fossil energy substitution by renewable energy sources: electricity, heat and traffic. 5. Emissions from different energy supply lines: electricity, heat, traffic. 6. Results of the emissions accounting for renewable energy sources: electricity, heat, traffic and comprehensive review. 7. Retroacting accounting and forward projection.

  10. Multi-Model Simulations of Aerosol and Ozone Radiative Forcing Due to Anthropogenic Emission Changes During the Period 1990-2015

    Science.gov (United States)

    Myhre, Gunnar; Aas, Wenche; Ribu, Cherian; Collins, William; Faluvegi, Gregory S.; Flanner, Mark; Forster, Piers; Hodnebrog, Oivind; Klimont, Zbigniew; Lund, Marianne T.

    2017-01-01

    Over the past few decades, the geographical distribution of emissions of substances that alter the atmospheric energy balance has changed due to economic growth and air pollution regulations. Here, we show the resulting changes to aerosol and ozone abundances and their radiative forcing using recently updated emission data for the period 1990-2015, as simulated by seven global atmospheric composition models. The models broadly reproduce large-scale changes in surface aerosol and ozone based on observations (e.g. 1 to 3 percent per year in aerosols over the USA and Europe). The global mean radiative forcing due to ozone and aerosol changes over the 1990-2015 period increased by 0.17 plus or minus 0.08 watts per square meter, with approximately one-third due to ozone. This increase is more strongly positive than that reported in IPCC AR5 (Intergovernmental Panel on Climate Change Fifth Assessment Report). The main reasons for the increased positive radiative forcing of aerosols over this period are the substantial reduction of global mean SO2 emissions, which is stronger in the new emission inventory compared to that used in the IPCC analysis, and higher black carbon emissions.

  11. Multi-Model Simulations of Aerosol and Ozone Radiative Forcing Due to Anthropogenic Emission Changes During the Period 1990-2015

    Science.gov (United States)

    Myhre, Gunnar; Aas, Wenche; Ribu, Cherian; Collins, William; Faluvegi, Gregory S.; Flanner, Mark; Forster, Piers; Hodnebrog, Oivind; Klimont, Zbigniew; Lund, Marianne T.

    2017-01-01

    Over the past few decades, the geographical distribution of emissions of substances that alter the atmospheric energy balance has changed due to economic growth and air pollution regulations. Here, we show the resulting changes to aerosol and ozone abundances and their radiative forcing using recently updated emission data for the period 1990-2015, as simulated by seven global atmospheric composition models. The models broadly reproduce large-scale changes in surface aerosol and ozone based on observations (e.g. 1 to 3 percent per year in aerosols over the USA and Europe). The global mean radiative forcing due to ozone and aerosol changes over the 1990-2015 period increased by 0.17 plus or minus 0.08 watts per square meter, with approximately one-third due to ozone. This increase is more strongly positive than that reported in IPCC AR5 (Intergovernmental Panel on Climate Change Fifth Assessment Report). The main reasons for the increased positive radiative forcing of aerosols over this period are the substantial reduction of global mean SO2 emissions, which is stronger in the new emission inventory compared to that used in the IPCC analysis, and higher black carbon emissions.

  12. Multi-model simulations of aerosol and ozone radiative forcing due to anthropogenic emission changes during the period 1990-2015

    Science.gov (United States)

    Myhre, Gunnar; Aas, Wenche; Cherian, Ribu; Collins, William; Faluvegi, Greg; Flanner, Mark; Forster, Piers; Hodnebrog, Øivind; Klimont, Zbigniew; Lund, Marianne T.; Mülmenstädt, Johannes; Myhre, Cathrine Lund; Olivié, Dirk; Prather, Michael; Quaas, Johannes; Samset, Bjørn H.; Schnell, Jordan L.; Schulz, Michael; Shindell, Drew; Skeie, Ragnhild B.; Takemura, Toshihiko; Tsyro, Svetlana

    2017-02-01

    Over the past few decades, the geographical distribution of emissions of substances that alter the atmospheric energy balance has changed due to economic growth and air pollution regulations. Here, we show the resulting changes to aerosol and ozone abundances and their radiative forcing using recently updated emission data for the period 1990-2015, as simulated by seven global atmospheric composition models. The models broadly reproduce large-scale changes in surface aerosol and ozone based on observations (e.g. -1 to -3 % yr-1 in aerosols over the USA and Europe). The global mean radiative forcing due to ozone and aerosol changes over the 1990-2015 period increased by +0.17 ± 0.08 W m-2, with approximately one-third due to ozone. This increase is more strongly positive than that reported in IPCC AR5. The main reasons for the increased positive radiative forcing of aerosols over this period are the substantial reduction of global mean SO2 emissions, which is stronger in the new emission inventory compared to that used in the IPCC analysis, and higher black carbon emissions.

  13. Small global effect on terrestrial net primary production due to increased fossil fuel aerosol emissions from East Asia since the turn of the century

    Science.gov (United States)

    O'Sullivan, M.; Rap, A.; Reddington, C. L.; Spracklen, D. V.; Gloor, M.; Buermann, W.

    2016-08-01

    The global terrestrial carbon sink has increased since the start of this century at a time of growing carbon emissions from fossil fuel burning. Here we test the hypothesis that increases in atmospheric aerosols from fossil fuel burning enhanced the diffuse light fraction and the efficiency of plant carbon uptake. Using a combination of models, we estimate that at global scale changes in light regimes from fossil fuel aerosol emissions had only a small negative effect on the increase in terrestrial net primary production over the period 1998-2010. Hereby, the substantial increases in fossil fuel aerosol emissions and plant carbon uptake over East Asia were effectively canceled by opposing trends across Europe and North America. This suggests that if the recent increase in the land carbon sink would be causally linked to fossil fuel emissions, it is unlikely via the effect of aerosols but due to other factors such as nitrogen deposition or nitrogen-carbon interactions.

  14. Small global effect on terrestrial net primary production due to increased fossil fuel aerosol emissions from East Asia since the turn of the century.

    Science.gov (United States)

    O'Sullivan, M; Rap, A; Reddington, C L; Spracklen, D V; Gloor, M; Buermann, W

    2016-08-16

    The global terrestrial carbon sink has increased since the start of this century at a time of growing carbon emissions from fossil fuel burning. Here we test the hypothesis that increases in atmospheric aerosols from fossil fuel burning enhanced the diffuse light fraction and the efficiency of plant carbon uptake. Using a combination of models, we estimate that at global scale changes in light regimes from fossil fuel aerosol emissions had only a small negative effect on the increase in terrestrial net primary production over the period 1998-2010. Hereby, the substantial increases in fossil fuel aerosol emissions and plant carbon uptake over East Asia were effectively canceled by opposing trends across Europe and North America. This suggests that if the recent increase in the land carbon sink would be causally linked to fossil fuel emissions, it is unlikely via the effect of aerosols but due to other factors such as nitrogen deposition or nitrogen-carbon interactions.

  15. Estimate of sulfur, arsenic, mercury, fluorine emissions due to spontaneous combustion of coal gangue: An important part of Chinese emission inventories.

    Science.gov (United States)

    Wang, Shaobin; Luo, Kunli; Wang, Xing; Sun, Yuzhuang

    2016-02-01

    A rough estimate of the annual amount of sulfur, arsenic, mercury and fluoride emission from spontaneous combustion of coal gangue in China was determined. The weighted mean concentrations of S, As, Hg, and F in coal gangue are 1.01%, 7.98, 0.18, and 365.54 mg/kg, respectively. Amounts of S, As, Hg, and F emissions from coal gangue spontaneous combustion show approximately 1.13 Mt, and 246, 45, and 63,298 tons in 2013, respectively. The atmospheric release amount of sulfur from coal gangue is more than one tenth of this from coal combustion, and the amounts of As, Hg, and F are close to or even exceed those from coal combustion. China's coal gangue production growth from 1992 to 2013 show an obvious growth since 2002. It may indicate that Chinese coal gangue has become a potential source of air pollution, which should be included in emission inventories.

  16. The impacts of electricity dispatch protocols on the emission reductions due to wind power and carbon tax.

    Science.gov (United States)

    Yu, Yang; Rajagopal, Ram

    2015-02-17

    Two dispatch protocols have been adopted by electricity markets to deal with the uncertainty of wind power but the effects of the selection between the dispatch protocols have not been comprehensively analyzed. We establish a framework to compare the impacts of adopting different dispatch protocols on the efficacy of using wind power and implementing a carbon tax to reduce emissions. We suggest that a market has high potential to achieve greater emission reduction by adopting the stochastic dispatch protocol instead of the static protocol when the wind energy in the market is highly uncertain or the market has enough adjustable generators, such as gas-fired combustion generators. Furthermore, the carbon-tax policy is more cost-efficient for reducing CO2 emission when the market operates according to the stochastic protocol rather than the static protocol. An empirical study, which is calibrated according to the data from the Electric Reliability Council of Texas market, confirms that using wind energy in the Texas market results in a 12% CO2 emission reduction when the market uses the stochastic dispatch protocol instead of the 8% emission reduction associated with the static protocol. In addition, if a 6$/ton carbon tax is implemented in the Texas market operated according to the stochastic protocol, the CO2 emission is similar to the emission level from the same market with a 16$/ton carbon tax operated according to the static protocol. Correspondingly, the 16$/ton carbon tax associated with the static protocol costs 42.6% more than the 6$/ton carbon tax associated with the stochastic protocol.

  17. Air-pollution emission control in China: impacts on soil acidification recovery and constraints due to drought.

    Science.gov (United States)

    Duan, Lei; Liu, Jing; Xin, Yan; Larssen, Thorjørn

    2013-10-01

    The Chinese government has established compulsory targets to reduce sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions by 8% and 10%, respectively, during 2010-2015. In this study, the effect of the policy was evaluated by predicting the recovery of acidified forest soil in Chongqing, an area severely impacted by acid rain in southwest China. Since precipitation has decreased significantly in this area in recent years, the impact of drought on soil acidification was also considered. A dynamic acidification model, MAGIC, was used to predict future trends in soil chemistry under different scenarios for deposition reduction as well as drought. We found that the current regulation of SO2 emission abatement did not significantly increase soil water pH values, the Ca2+ to Al3+ molar ratio (Ca/Al), or soil base saturation to the level of 2000 before 2050. NOx emission control would have less of an effect on acidification recovery, while emission reduction of particulate matter could offset the benefits of SO2 reduction by greatly decreasing the deposition of base cations, particularly Ca(2+). Continuous droughts in the future might also delay acidification recovery. Therefore, more stringent SO2 emission control should be implemented to facilitate the recovery of seriously acidified areas in China.

  18. Study of the impact of board orientation on radiated emissions due to common-mode currents on attached cables

    DEFF Research Database (Denmark)

    Sørensen, Morten; Hubing, Todd H.; Jensen, Kim

    2016-01-01

    Common-mode current on attached cables is a typical source for radiated emission. Several models have been made for conversion of the intended differential signal to unwanted common-mode current on cables. In this paper we refine a method for identifying the radiation sources arising from a long...... microstrip. This method is used to show that the radiated emission from a PCB with attached cable(s) caused by a long trace depends on whether the trace is facing up or down with different result for voltage and current sources....

  19. Quantification of emissions due to the natural gas storage well-casing blowout at Aliso Canyon/SS-25 using tracer flux ratio methods.

    Science.gov (United States)

    Herndon, S. C.; Daube, C.; Jervis, D.; Yacovitch, T. I.; Roscioli, J. R.; Curry, J.; Nelson, D. D.; Knighton, W. B.

    2016-12-01

    The methane emission rate from the well blowout at Aliso Canyon Natural Gas Storage Facility in Porter Ranch, California was quantified using the tracer flux ratio method (TFR). Over 400 tracer plume transects were collected, each lasting 15-300 seconds, using instrumentation aboard a mobile platform on 25 days between December 21, 2015 and March 9, 2016. The leak rate from October 23rd to February 11th has been estimated here using a combination of our leak rate measurements (TFR) and the flight mass balance (FMB) data [Conley et al., 2016]. The TFR approach employed here is assessing only the leaks due to the SS-25 well blowout and excludes other possible emissions at the facility. By "calibrating" the FMB dataset, the leak rate is integrated from Oct 23rd to December 21th. The sum of the inferred inferred and measured meissions suggests a total leak burden of 86,022 ± 8,393 metric tons of CH4. The primary uncertainty in this value is due to the uncertainty in the emission rate prior to the beginning of the TFR quantification. The ethane to methane enhancement ratio observed downwind of the leak site is consistent with the content of ethane in the natural gas at this site and provides definitive evidence that the methane emission rate quantified via tracer flux ratio is not due to a nearby landfill or other potential biogenic sources.

  20. Cross-border electricity market effects due to price caps in an emission trading system: An agent-based approach

    NARCIS (Netherlands)

    Richstein, J.C.; Chappin, E.J.L.; De Vries, L.J.

    2014-01-01

    The recent low CO2 prices in the European Union Emission Trading Scheme (EU ETS) have triggered a discussion whether the EU ETS needs to be adjusted. We study the effects of CO2 price floors and a price ceiling on the dynamic investment pathway of two interlinked electricity markets (loosely based o

  1. FUGITIVE EMISSION REDUCTIONS DUE TO THE USE OF ENCLOSED DOCTOR BLADE SYSTEMS IN THE FLEXOGRAPHIC AND ROTOGRAVURE PRINTING INDUSTRIES

    Science.gov (United States)

    The report gives results of a quantification of the level of fugitive emission reductions resulting from the use of enclosed doctor blade (EDB) systems in place of traditional ink feed systems at flexographic and rotogravure printing operations. An EDB system is an innovative ink...

  2. FUGITIVE EMISSION REDUCTIONS DUE TO THE USE OF ENCLOSED DOCTOR BLADE SYSTEMS IN THE FLEXOGRAPHIC AND ROTOGRAVURE PRINTING INDUSTRIES

    Science.gov (United States)

    The report gives results of a quantification of the level of fugitive emission reductions resulting from the use of enclosed doctor blade (EDB) systems in place of traditional ink feed systems at flexographic and rotogravure printing operations. An EDB system is an innovative ink...

  3. Cross-border electricity market effects due to price caps in an emission trading system: An agent-based approach

    NARCIS (Netherlands)

    Richstein, J.C.; Chappin, E.J.L.; De Vries, L.J.

    2014-01-01

    The recent low CO2 prices in the European Union Emission Trading Scheme (EU ETS) have triggered a discussion whether the EU ETS needs to be adjusted. We study the effects of CO2 price floors and a price ceiling on the dynamic investment pathway of two interlinked electricity markets (loosely based

  4. Record high peaks in PCB concentrations in the Arctic atmosphere due to long-range transport of biomass burning emissions

    Directory of Open Access Journals (Sweden)

    S. Eckhardt

    2007-05-01

    Full Text Available Soils and forests in the boreal region of the northern hemisphere are recognised as having a large capacity for storing air-borne Persistent Organic Pollutants (POPs, such as the polychlorinated biphenyls (PCBs. Following reductions of primary emissions of various legacy POPs, there is an increasing interest and debate about the relative importance of secondary re-emissions on the atmospheric levels of POPs. In spring of 2006, biomass burning emissions from agricultural fires in Eastern Europe were transported to the Zeppelin station on Svalbard, where record-high levels of many air pollutants were recorded (Stohl et al., 2007. Here we report on the extremely high concentrations of PCBs that were also measured during this period. 21 out of 32 PCB congeners were enhanced by more than two standard deviations above the long-term mean concentrations. In July 2004, about 5.8 million hectare of boreal forest burned in North America, emitting a pollution plume which reached the Zeppelin station after a travel time of 3–4 weeks (Stohl et al., 2006. Again, 12 PCB congeners were elevated above the long-term mean by more than two standard deviations, with the less chlorinated congeners being most strongly affected. We propose that these abnormally high concentrations were caused by biomass burning emissions. Based on enhancement ratios with carbon monoxide and known emissions factors for this species, we estimate that 130 and 66 μg PCBs were released per kilogram dry matter burned, respectively. To our knowledge, this is the first study relating atmospheric PCB enhancements with biomass burning. The strong effects on observed concentrations far away from the sources, suggest that biomass burning is an important source of PCBs for the atmosphere.

  5. A relativistic self-consistent model for studying enhancement of space charge limited emission due to counter-streaming ions

    Science.gov (United States)

    Lin, M. C.; Verboncoeur, J.

    2016-10-01

    A maximum electron current transmitted through a planar diode gap is limited by space charge of electrons dwelling across the gap region, the so called space charge limited (SCL) emission. By introducing a counter-streaming ion flow to neutralize the electron charge density, the SCL emission can be dramatically raised, so electron current transmission gets enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of maximum transmission by a counter-streaming ion current. The maximum enhancement is found when the ion effect is saturated, as shown analytically. The solutions in non-relativistic, intermediate, and ultra-relativistic regimes are obtained and verified with 1-D particle-in-cell simulations. This self-consistent model is general and can also serve as a comparison for verification of simulation codes, as well as extension to higher dimensions.

  6. Changes in Hydrologic Conditions and Greenhouse Gas Emissions in Circumpolar Regions due to Climate Change-Induced Permafrost Retreat

    Science.gov (United States)

    Whiticar, M. J.; Bhatti, J.; Startsev, N.

    2012-12-01

    Thawing permafrost peatlands influence northern ecosystems by changing the regional hydrology and mobilizing the vast carbon (C) reserves that results in increased greenhouse gas (GHGs) emissions to the atmosphere. With permafrost distribution controlled largely by topography and climate, our IPY study intensively monitored the local C cycling processes and GHG fluxes associated with different hydrologic and permafrost environments at 4 sites along a latitudinal climatic gradient of Boreal, Subarctic and Arctic ecoclimatic regions that extend south-north from the Isolated Patches Permafrost Zone (northern Alberta), to the Continuous Permafrost Zone (Inuvik, NWT). Each site encompasses a local hydrologic gradient from upland forest and peat plateau to collapse scar. Our multi-year measurements of peatland profiles and flux chambers for CH4 and CO2 concentrations and stable isotope ratios indicate processes, including methanogenesis, methanotrophy, transport and emission that control the distribution of these GHGs. These relationships are modulated by fluctuating local soil water and corresponding ecosystem conditions. The gas geochemistry shows that significant surface CH4 production occurs by both hydrogenotrophic and methyl-fermentative methanogenesis in submerged, anaerobic peats, e.g., collapse scars, whereas methane oxidation is restricted to aerobic, drier environments, e.g., upland sites and peat-atmosphere interface. The most active methanogenesis and emissions are in areas of actively thawing permafrost contrasting with sites under continuous permafrost. This degree of methanogenesis is being amplified by the increased rate of Arctic warming and the rapid retreat of permafrost in Canada's Arctic (ca. 2.5 km/yr).

  7. Increase in polycyclic aromatic hydrocarbon (PAH) emissions due to briquetting: A challenge to the coal briquetting policy.

    Science.gov (United States)

    Chen, Yingjun; Zhi, Guorui; Feng, Yanli; Chongguo Tian; Bi, Xinhui; Li, Jun; Zhang, Gan

    2015-09-01

    Both China and UNEP recommend replacing raw coal chunks with coal briquettes in household sector as clean coal technology (CCT), which has been confirmed by the decreased emissions of particulate matter and black carbon. However, the clean effect has never been systematically checked by other pollutants like polycyclic aromatic hydrocarbons (PAHs). In this study, 5 coals with different geological maturities were processed as both chunks and briquettes and burned in 3 typical coal stoves for the measurement of emission factors (EFs) of particle-bound PAHs. It was found that the EFs of 16 parent PAHs, 26 nitrated PAHs, 6 oxygenated PAHs, and 8 alkylated PAHs for coal briquettes were 6.90 ± 7.89, 0.04 ± 0.03, 0.65 ± 0.40, and 72.78 ± 18.23 mg/kg, respectively, which were approximately 3.1, 3.7, 1.9, and 171 times those for coal chunks, respectively. Such significant increases in PAH emissions increased human health risk and challenged the policy of CCT. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Future Premature Mortality Due to O3, Secondary Inorganic Aerosols and Primary PM in Europe — Sensitivity to Changes in Climate, Anthropogenic Emissions, Population and Building Stock

    Directory of Open Access Journals (Sweden)

    Camilla Geels

    2015-03-01

    Full Text Available Air pollution is an important environmental factor associated with health impacts in Europe and considerable resources are used to reduce exposure to air pollution through emission reductions. These reductions will have non-linear effects on exposure due, e.g., to interactions between climate and atmospheric chemistry. By using an integrated assessment model, we quantify the effect of changes in climate, emissions and population demography on exposure and health impacts in Europe. The sensitivity to the changes is assessed by investigating the differences between the decades 2000–2009, 2050–2059 and 2080–2089. We focus on the number of premature deaths related to atmospheric ozone, Secondary Inorganic Aerosols and primary PM. For the Nordic region we furthermore include a projection on how population exposure might develop due to changes in building stock with increased energy efficiency. Reductions in emissions cause a large significant decrease in mortality, while climate effects on chemistry and emissions only affects premature mortality by a few percent. Changes in population demography lead to a larger relative increase in chronic mortality than the relative increase in population. Finally, the projected changes in building stock and infiltration rates in the Nordic indicate that this factor may be very important for assessments of population exposure in the future.

  9. Future Premature Mortality Due to O3, Secondary Inorganic Aerosols and Primary PM in Europe — Sensitivity to Changes in Climate, Anthropogenic Emissions, Population and Building Stock

    Science.gov (United States)

    Geels, Camilla; Andersson, Camilla; Hänninen, Otto; Lansø, Anne Sofie; Schwarze, Per E.; Ambelas Skjøth, Carsten; Brandt, Jørgen

    2015-01-01

    Air pollution is an important environmental factor associated with health impacts in Europe and considerable resources are used to reduce exposure to air pollution through emission reductions. These reductions will have non-linear effects on exposure due, e.g., to interactions between climate and atmospheric chemistry. By using an integrated assessment model, we quantify the effect of changes in climate, emissions and population demography on exposure and health impacts in Europe. The sensitivity to the changes is assessed by investigating the differences between the decades 2000–2009, 2050–2059 and 2080–2089. We focus on the number of premature deaths related to atmospheric ozone, Secondary Inorganic Aerosols and primary PM. For the Nordic region we furthermore include a projection on how population exposure might develop due to changes in building stock with increased energy efficiency. Reductions in emissions cause a large significant decrease in mortality, while climate effects on chemistry and emissions only affects premature mortality by a few percent. Changes in population demography lead to a larger relative increase in chronic mortality than the relative increase in population. Finally, the projected changes in building stock and infiltration rates in the Nordic indicate that this factor may be very important for assessments of population exposure in the future. PMID:25749320

  10. Quantifying the uncertainty in simulating global tropospheric composition due to the variability in global emission estimates of Biogenic Volatile Organic Compounds

    Directory of Open Access Journals (Sweden)

    J. E. Williams

    2012-11-01

    Full Text Available The emission of organic compounds from biogenic processes acts as an important source of trace gases in remote regions away from urban conurbations, and is likely to become more important in future decades due to the further mitigation of anthropogenic emissions that affect air quality and climate forcing. In this study we examine the contribution of biogenic volatile organic compounds (BVOCs towards global tropospheric composition using the global 3-D chemistry transport model TM5 and the recently developed modified CB05 chemical mechanism. By comparing regional BVOC emission estimates we show that biogenic processes act as dominant sources for many regions and exhibit a large variability in the annually and seasonally integrated emission fluxes. By performing sensitivity studies we find that the contribution of BVOC species containing between 1 to 3 carbon atoms has an impact on the resident mixing ratios of tropospheric O3 and CO, accounting for ~3% and ~11% of the simulated global distribution, respectively. This is approximately a third of the cumulative effect introduced by isoprene and the monoterpenes. By examining an ensemble of 3-D global chemistry-transport simulations which adopt different global BVOC emission inventories we determine the associated uncertainty introduced towards simulating the composition of the troposphere for the year 2000. By comparing the model ensemble values against a~composite of atmospheric measurements we show that the effects on tropospheric O3 are limited to the lower troposphere (with an uncertainty between −2% to 10%, whereas that for tropospheric CO extends up to the upper troposphere (with an uncertainty of between 10 to 45%. Comparing the mixing ratios for low molecular weight alkenes in TM5 against surface measurements taken in Europe implies that the cumulative emission estimates are too low, regardless of the chosen BVOC inventory. This variability in the global

  11. The Ultraviolet Emission Properties of Five Low-Redshift Active Galactic Nuclei at High Signal to Noise and Spectral Resolution

    CERN Document Server

    Laor, A; Jannuzi, B T; Schneider, D P; Green, R F; Hartig, G F; Laor, Ari; Bahcall, John N.; Jannuzi, Buell T.; Schneider, Donald P.; Green, IAS; Richard F.; Hartig, NOAO; George F.; ScI, ST

    1994-01-01

    We analyze the ultraviolet (UV) emission line and continuum properties of five low-redshift active galactic nuclei (four luminous quasars: PKS~0405$-$123, H1821+643, PG~0953+414, and 3C273, and one bright Seyfert 1 galaxy: Mrk~205). The HST spectra have higher signal-to-noise ratios (typically $\\sim 60$ per resolution element) and spectral resolution ($R = 1300$) than all previously- published UV spectra used to study the emission characteristics of active galactic nuclei. We include in the analysis ground-based optical spectra covering \\hb\\ and the narrow [O~III]~$\\lambda\\lambda$4959,5007 doublet. The following new results are obtained: \\lyb/\\lya=0.03$-$0.12 for the four quasars, which is the first accurate measurement of the long-predicted \\lyb\\ intensity in QSOs. The cores of \\lya\\ and C~IV are symmetric to an accuracy of better than 2.5\\% within about 2000~km~s$^{-1}$ of the line peak. This high degree of symmetry of \\lya\\ argues against models in which the broad line cloud velocity field has a significan...

  12. Enhanced emission and photoconductivity due to photo-induced charge transfer from Au nanoislands to ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shang-Hsuan; Chan, Ching-Hsiang; Liang, Ching-Tarng [Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan (China); Chien, Ching-Hang; Yaseen, Mohammad Tariq [Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan (China); Nano Science and Technology Program, TIGP, Academia Sinica, Taipei 115, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Chang, Yia-Chung, E-mail: yiachang@gate.sinica.edu.tw [Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan (China); Department of Physics, National Cheng Kung University, Tainan 701, Taiwan (China)

    2016-01-25

    We report systematic studies based on photoluminescence, Hall, and photoconductivity measurements together with theoretical modeling in order to identify mechanisms for the photo-induced charge transfer effects in ZnO thin film incorporated with the Au nano-islands (AuNIs). Significant enhancement of near band edge emission and improvement in conductivity of ZnO/AuNIs samples after illumination are observed, which are attributed to the photo-induced hot electrons in Au which are then transferred into the conduction band of ZnO as long as the excitation energy is higher than the offset between the ZnO conduction-band minimum and Au Fermi level. Our experimental results are consistent with the general features predicted by first principles calculations.

  13. Secondary electron emission from a charged spherical dust particle due to electron incidence according to OML model

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Y., E-mail: tomita@swip.ac.cn [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Huang, Z.H.; Pan, Y.D. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Kawamura, G. [National Institute for Fusion Science, Toki 509-5292 (Japan); Yan, L.W. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China)

    2015-08-15

    Effect of secondary electron emission (SEE) current to dust charging and influence to forces on a dust particle are studied according to the orbital motion limited (OML) model. As higher electron temperature increases the SEE current, the negative dust charge decreases. As a result, the ion friction force on the dust particle decreases. The critical electron temperatures without the dust charge are 75.1, 70.3 and 55.9 eV for graphite and are 31.3, 30.4 and 27.1 eV for tungsten to the temperature ratio T{sub i}/T{sub e} = 0.1, 1.0 and 10.0, respectively. At the critical electron temperature, there is no ion scattering force but the ion absorption force remains finite.

  14. Non-relativistic Free–Free Emission due to the n-distribution of Electrons—Radiative Cooling and Thermally Averaged and Total Gaunt Factors

    Science.gov (United States)

    de Avillez, Miguel A.; Breitschwerdt, Dieter

    2017-09-01

    Tracking the thermal evolution of plasmas, characterized by an n-distribution, using numerical simulations, requires the determination of the emission spectra and of the radiative losses due to free–free emission from the corresponding temperature-averaged and total Gaunt factors. Detailed calculations of the latter are presented and associated with n-distributed electrons with the parameter n ranging from 1 (corresponding to the Maxwell–Boltzmann distribution) to 100. The temperature-averaged and total Gaunt factors with decreasing n tend toward those obtained with the Maxwell–Boltzmann distribution. Radiative losses due to free–free emission in a plasma evolving under collisional ionization equilibrium conditions and composed by H, He, C, N, O, Ne, Mg, Si, S, and Fe ions, are presented. These losses decrease with a decrease in the parameter n, reaching a minimum when n = 1, and thus converge with the loss of thermal plasma. Tables of the thermal-averaged and total Gaunt factors calculated for n-distributions, and a wide range of electron and photon energies, are presented.

  15. 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 prominent...... tail of the Lya + 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...

  16. Radiative forcing due to greenhouse gas emission and sink histories in Finland and its future control potential

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen, I.; Sinisalo, J.; Pipatti, R. [VTT Energy, Espoo (Finland)

    1995-12-31

    The effective atmospheric lifetimes of the greenhouse gases like carbon dioxide (CO{sub 2}),nitrous oxide (N{sub 2}O) and many of the CFCs are of the order of 100 years. Human activities, as an example GDP, very often change at rates of a few per cents per year,corresponding time constants of some tens of years. Also the forest ecosystems have time constants of this order. Even the human population of the globe is increasing by about two percent per year. Because so many natural and human-linked processes, which are relevant to global warming, have slow change rates of about same order, a time-dependent consideration of the greenhouse warming and its control can give useful information for the understanding of the problem. The objective of the work is to study the anthropogenic greenhouse gas emissions and sinks in Finland and their greenhouse impact as a function of time. The greenhouse impact is expressed in terms of radiative forcing which describes the perturbation in the Earth`s radiation budget. Radiative forcing allows a comparison of the impact of various greenhouse gases and their possible control options as a function of time. The idea behind the calculations is that Finland should in some way steer its share of the global radiative forcing and greenhouse effect. This presentation describes the calculation model REFUGE and the projects in which it has been used

  17. Investigation of background in large-area neutron detectors due to alpha emission from impurities in aluminium

    CERN Document Server

    Birch, J; Clergeau, J -F; van Esch, P; Ferraton, M; Guerard, B; Hall-Wilton, R; Hultman, L; Höglund, C; Jensen, J; Khaplanov, A; Piscitelli, F

    2015-01-01

    Thermal neutron detector based on films of $^{10}$B$_4$C have been developed as an alternative to $^3$He detectors. In particular, The Multi-Grid detector concept is considered for future large area detectors for ESS and ILL instruments. An excellent signal-to-background ratio is essential to attain expected scientific results. Aluminium is the most natural material for the mechanical structure of of the Multi-Grid detector and other similar concepts due to its mechanical and neutronic properties. Due to natural concentration of $\\alpha$ emitters, however, the background from $\\alpha$ particles misidentified as neutrons can be unacceptably high. We present our experience operating a detector prototype affected by this issue. Monte Carlo simulations have been used to confirm the background as $\\alpha$ particles. The issues have been addressed in the more recent implementations of the Multi-Grid detector by the use of purified aluminium as well as Ni-plating of standard aluminium. The result is the reduction in...

  18. Ion cyclotron emission due to the newly-born fusion products induced fast Alfven wave radiative instabilities in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Arunasalam, V.

    1995-08-01

    The velocity distribution functions of the newly born (t = 0) charged fusion products of tokamak discharges can be approximated by a monoenergetic ring distribution with a finite v{sub {parallel}} such that v{sub {perpendicular}} {approx} v{sub {parallel}} {approx} v{sub j} where (M{sub j}V{sub j}{sup 2}/2) = E{sub j}, the directed birth energy of the charged fusion product species j of mass M{sub j}. As the time t progresses these distribution functions will evolve into a Gaussian in velocity with thermal spreadings given by the perpendicular and parallel temperatures T{sub {perpendicular}j}(t) = T{sub {parallel}j}(t) with T{sub j}(t) increasing as t increases and finally reaches an isotropic saturation value of T{sub {perpendicular}j}(t {approx} {tau}{sub j}) = T{sub {parallel}j}(t {approx} {tau}{sub j}) = T{sub j}(t {approx} {tau}{sub j}) {approx} [M{sub j}T{sub d}E{sub j}/(M{sub j} + M)]{sup 1/2}, where T{sub d} is the temperature of the background deuterium plasma ions, M is the mass of a triton or a neutron for j = protons and alpha particles, respectively, and {tau}{sub j} {approx} {tau}{sub sj}/4 is the thermalization time of the fusion product species j in the background deuterium plasma and {tau}{sub sj} is the slowing-down time. For times t of the order of {tau}{sub j} their distributions can be approximated by a Gaussian in their total energy. Then for times t {ge} {tau}{sub sj} the velocity distributions of these fusion products will relax towards their appropriate slowing-down distributions. Here the authors will examine the radiative stability of all these distributions. The ion cyclotron emission from energetic ion produced by fusion reactions or neutral beam injection promises to be a useful diagnostic tool.

  19. Short term responses of nitrogen trace gas emissions to nitrogen fertilization in tropical sugar cane: Variations due to soils and management practices

    Science.gov (United States)

    Matson, P. A.; Billow, C.; Hall, S.; Zachariassen, J.

    1994-01-01

    Nitrogen (N) fertilization of agricultural systems is thought to be a major source of the increase in atmospheric N2O; NO emissions from soils have also been shown to increase due to N fertilization. While N fertilizer use is increasing rapidly in the developing world and in the tropics, nearly all of our information on gas emissions is derived from studies of temperate zone agriculture. Using chambers, we measured fluxes of N2O and NO following urea fertilization in tropical sugar cane systems growing on a variety of soil types in the Hawaiian Islands, USA. On the island of Maui, where urea is applied in irrigation lines and soils are mollisols and inceptisols, N2O fluxes were elevated for a week or less following fertilization; maximum average fluxes were typically less than 30 ng cm(exp -2)/ h. NO fluxes were often an order of magnitude less than N2O. Together, N2O and NO represented from 0.01 - 0.5% of the applied N. In fields on the island of Hawaii, where urea is broadcast on the surface and soils are andisols, N2O fluxes were similar in magnitude to Maui but remained elevated for much longer periods after fertilization. NO emissions were 2-5 times higher than N2O through most of the sampling periods. Together the gases loss represented approximately 1. 1 - 3% of the applied N. Laboratory studies indicate that denitrification is a critical source of N2O in Maui, but that nitrification is more important in Hawaii. Experimental studies suggest that differences in the pattern of N2O/NO and the processes producing them are a result of both carbon availability and placement of fertilizer, and that the more information-intensive fertilizer management practice results in lower emissions.

  20. Brain glucose metabolic changes associated with chronic spontaneous Pain due to brachial plexus avulsion:a preliminary positron emission tomography study

    Institute of Scientific and Technical Information of China (English)

    CHEN Fu-yong; TAO Wei; CHENG Xin; WANG Hong-yan; HU Yong-sheng; ZHANG Xiao-hua; LI Yong-jie

    2008-01-01

    Background Previous brain imaging studies suggested that the brain activity underlying the perception of chronic pain maV differ from that underlying acute pain.To investigate the brain regions involved in chronic spontaneous pain due to brachial plexus avulsion(BPA),fluorine-18fluorodeoxygIucose (19F-FDG) positron emission tomography (PET) scanning was applied to determine the glucose metabolic changes in patients with pain due to BPA.Methods Six right-handed patients with chronic spontaneous pain due to left-BPA and twelve right-handed age-and sex-matched healthy control subjects participated in the 18F-FDG PET study.The patients were rated by visual analog scale (VAS) during scanning and Hamilton depression scale and Hamilton anxiety scale after scanning.Statistical parametric mapping 2 (SPM2) was applied for data analysis.Results Compared with healthy subjects,the patients had significant glucose metabolism decreases in the right thalamus and S I(P<0.001,uncorrected),and significant glucose metabolism increases in the right orbitofrontaI cortex (OFC) (BA11),left rostral insula cortex and left dorsolateral prefrontal codex (DLPFC) (BA10/46) (P<0.001,uncorrected).Conclusion These findings suggest that the brain areas involved in emotion.aRention and internal modulation of pain may be related to the chronic spontaneous pain due to BPA.

  1. Influence on the oxidative potential of a heavy-duty engine particle emission due to selective catalytic reduction system and biodiesel blend

    Energy Technology Data Exchange (ETDEWEB)

    Godoi, Ricardo H.M., E-mail: rhmgodoi@ufpr.br [Environmental Engineering Department, Federal University of Parana, Curitiba, PR (Brazil); Polezer, Gabriela; Borillo, Guilherme C. [Environmental Engineering Department, Federal University of Parana, Curitiba, PR (Brazil); Brown, Andrew [Division of Chemistry and Environmental Science, School of Science and the Environment, Manchester Metropolitan University, Manchester (United Kingdom); Valebona, Fabio B.; Silva, Thiago O.B.; Ingberman, Aline B.G. [Environmental Engineering Department, Federal University of Parana, Curitiba, PR (Brazil); Nalin, Marcelo [LAVIE - Institute of Chemistry, São Paulo State University - UNESP, Araraquara (Brazil); Yamamoto, Carlos I. [Chemical Engineering Department, Federal University of Parana, Curitiba, PR (Brazil); Potgieter-Vermaak, Sanja [Division of Chemistry and Environmental Science, School of Science and the Environment, Manchester Metropolitan University, Manchester (United Kingdom); Penteado Neto, Renato A. [Vehicle Emissions Laboratory, Institute of Technology for Development (LACTEC), Curitiba, PR (Brazil); Marchi, Mary Rosa R. de [Analytical Chemistry Department, Institute of Chemistry, São Paulo State University - UNESP, Araraquara (Brazil); Saldiva, Paulo H.N. [Laboratory of Experimental Air Pollution, Department of Pathology, School of Medicine, University of São Paulo, São Paulo (Brazil); Pauliquevis, Theotonio [Department of Natural and Earth Sciences, Federal University of São Paulo, Diadema (Brazil); Godoi, Ana Flavia L. [Environmental Engineering Department, Federal University of Parana, Curitiba, PR (Brazil)

    2016-08-01

    Although the particulate matter (PM) emissions from biodiesel fuelled engines are acknowledged to be lower than those of fossil diesel, there is a concern on the impact of PM produced by biodiesel to human health. As the oxidative potential of PM has been suggested as trigger for adverse health effects, it was measured using the Electron Spin Resonance (OP{sup ESR}) technique. Additionally, Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF) was employed to determine elemental concentration, and Raman Spectroscopy was used to describe the amorphous carbon character of the soot collected on exhaust PM from biodiesel blends fuelled test-bed engine, with and without Selective Catalytic Reduction (SCR). OP{sup ESR} results showed higher oxidative potential per kWh of PM produced from a blend of 20% soybean biodiesel and 80% ULSD (B20) engine compared with a blend of 5% soybean biodiesel and 95% ULSD (B5), whereas the SCR was able to reduce oxidative potential for each fuel. EDXRF data indicates a correlation of 0.99 between concentration of copper and oxidative potential. Raman Spectroscopy centered on the expected carbon peaks between 1100 cm{sup −1} and 1600 cm{sup −1} indicate lower molecular disorder for the B20 particulate matter, an indicative of a more graphitic carbon structure. The analytical techniques used in this study highlight the link between biodiesel engine exhaust and increased oxidative potential relative to biodiesel addition on fossil diesel combustion. The EDXRF analysis confirmed the prominent role of metals on free radical production. As a whole, these results suggest that 20% of biodiesel blends run without SCR may pose an increased health risk due to an increase in OH radical generation. - Highlights: • PM emission from biodiesel burning may be more harmful to human health than diesel. • Euro V (SCR) engine fuelled with B5 and B20 tested in a bench dynamometer • Electron Spin Resonance (ESR) to access the oxidative potential of

  2. Anticipated changes in the emissions of green-house gases and ammonia from pork production due to shifts from fattening of barrows towards fattening of boars

    DEFF Research Database (Denmark)

    Dämmgen, Ulrich; Berk, Andreas; Otten, Caroline

    2013-01-01

    Greenhouse gases and of ammonia emissions from pork production will change when fattening of barrows switches towards to fattening of (intact) boars. The results of an accurate feeding experiment allow for the differentiation of the effects on emissions of gender (differentiating in boars, barrows...... effect of increased numbers of animals produced. The fattening of intact boars as compared to barrows is associated with a reduction of emissions of greenhouse gases and of ammonia per animal. For ammonia, all scenarios result in reduced emissions, most markedly when this shift is combined with increased...... weight gains. To a lesser extent, this also applies to nitric and nitrous oxide emissions. Methane emissions are less affected; increased weight gains result in increased emissions. As the greenhouse gas balance is dominated by methane emissions, the overall emission of greenhouse gases (expressed as CO2...

  3. Evaluation of Microscopic Deformation Behaviors of Metal Matrix Composite due to Heat Treatment by means of SFC Test and Acoustic Emission

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Moon Phil; Lee, Joon Hyun [Pusan National University, Busan (Korea, Republic of)

    2000-10-15

    Metal matrix composite(MMCs) have been rapidly becoming one of the strongest candidates for structural materials for high temperature application. It is well recognized that MMCs always experience at least one large cool-down from processing temperature before my significant applied service loading. Due to the large difference in thermal expansion coefficient between the fiber and matrix, large thermal residual stresses generally develop in composites. It was reported from many previous studies that the effects of thermal residual stress on mechanical properties and fracture behavior were much more complex and dramatic than conventional engineering materials. Therefore it is crucial to evaluate the effect of heat treatment which changes the characteristic of distribution of thermal residual stress in MMCs. Single fiber composite(SFC) test based on the balance in a micromechanical model is a quite convenient method to evaluate interfacial shear strength(IFSS) and the failure mode of composite. In this study the effect of heat treatment on IFSS and the microscopic failure mechanism of MMC is investigated by combining acoustic emission(AE) technique with SFC test. The characteristic of AE signal, IFSS and microscopic failure mechanism due to heat treatment condition is discussed

  4. BEER analysis of Kepler and CoRoT light curves: II. Evidence for emission phase shift due to superrotation in four Kepler hot Jupiters

    CERN Document Server

    Faigler, Simchon

    2014-01-01

    We analyzed the Kepler light curves of four transiting hot-Jupiter systems- KOI-13, HAT-P-7, TrES-2 and Kepler-76, which show BEaming, Ellipsoidal and Reflection (BEER) phase modulations. The mass of the four planets can be estimated from either the beaming or the ellipsoidal amplitude, given the mass and radii of their parent stars. For all four systems, we find that the beaming-based planetary-mass estimate is larger than the mass estimated from the ellipsoidal amplitude, consistent with previous studies for three of these systems- KOI-13, TrES-2 and Kepler-76. We suggest the apparent discrepancy is due to superrotation, first observed for HD 189733b in the infrared. Superrotation of a tidally-locked hot-Jupiter involves an eastward displacement of the planet hot spot from the substellar point, probably due to winds in the planetary atmosphere, an effect that induces an angle shift of the planet reflection/emission phase modulation. In our analysis this angle shift "leaks" into the beaming modulation, artif...

  5. Long-term modelling of fly ash and radionuclide emissions as well as deposition fluxes due to the operation of large oil shale-fired power plants.

    Science.gov (United States)

    Vaasma, Taavi; Kaasik, Marko; Loosaar, Jüri; Kiisk, Madis; Tkaczyk, Alan H

    2017-09-11

    Two of the world's largest oil shale-fired power plants (PPs) in Estonia have been operational over 40 years, emitting various pollutants, such as fly ash, SOx, NOx, heavy metals, volatile organic compounds as well as radionuclides to the environment. The emissions from these PPs have varied significantly during this period, with the maximum during the 1970s and 1980s. The oil shale burned in the PPs contains naturally occurring radionuclides from the (238)U and (232)Th decay series as well as (40)K. These radionuclides become enriched in fly ash fractions (up to 10 times), especially in the fine fly ash escaping the purification system. Using a validated Gaussian-plume model, atmospheric dispersion modelling was carried out to determine the quantity and a real magnitude of fly ash and radionuclide deposition fluxes during different decades. The maximum deposition fluxes of volatile radionuclides ((210)Pb and (210)Po) were around 70 mBq m(-2) d(-1) nearby the PPs during 1970s and 1980s. Due to the reduction of burned oil shale and significant renovations done on the PPs, the deposition fluxes were reduced to 10 mBq m(-2) d(-1) in the 2000s and down to 1.5 mBq m(-2) d(-1) in 2015. The maximum deposition occurs within couple of kilometers of the PPs, but the impacted area extends to over 50 km from the sources. For many radionuclides, including (210)Po, the PPs have been larger contributors of radionuclides to the environment via atmospheric pathway than natural sources. This is the first time that the emissions and deposition fluxes of radionuclides from the PPs have been quantified, providing the information about their radionuclide deposition load on the surrounding environment during various time periods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Long-term drainage reduces CO2 uptake and increases CO2 emission on a Siberian floodplain due to shifts in vegetation community and soil thermal characteristics

    Science.gov (United States)

    Kwon, Min Jung; Heimann, Martin; Kolle, Olaf; Luus, Kristina A.; Schuur, Edward A. G.; Zimov, Nikita; Zimov, Sergey A.; Göckede, Mathias

    2016-07-01

    With increasing air temperatures and changing precipitation patterns forecast for the Arctic over the coming decades, the thawing of ice-rich permafrost is expected to increasingly alter hydrological conditions by creating mosaics of wetter and drier areas. The objective of this study is to investigate how 10 years of lowered water table depths of wet floodplain ecosystems would affect CO2 fluxes measured using a closed chamber system, focusing on the role of long-term changes in soil thermal characteristics and vegetation community structure. Drainage diminishes the heat capacity and thermal conductivity of organic soil, leading to warmer soil temperatures in shallow layers during the daytime and colder soil temperatures in deeper layers, resulting in a reduction in thaw depths. These soil temperature changes can intensify growing-season heterotrophic respiration by up to 95 %. With decreased autotrophic respiration due to reduced gross primary production under these dry conditions, the differences in ecosystem respiration rates in the present study were 25 %. We also found that a decade-long drainage installation significantly increased shrub abundance, while decreasing Eriophorum angustifolium abundance resulted in Carex sp. dominance. These two changes had opposing influences on gross primary production during the growing season: while the increased abundance of shrubs slightly increased gross primary production, the replacement of E. angustifolium by Carex sp. significantly decreased it. With the effects of ecosystem respiration and gross primary production combined, net CO2 uptake rates varied between the two years, which can be attributed to Carex-dominated plots' sensitivity to climate. However, underlying processes showed consistent patterns: 10 years of drainage increased soil temperatures in shallow layers and replaced E. angustifolium by Carex sp., which increased CO2 emission and reduced CO2 uptake rates. During the non-growing season, drainage

  7. Investigation of aerosol based emission of MEA due to sulphuric acid aerosol and soot in a post combustion CO2 capture process

    NARCIS (Netherlands)

    Khakharia, P.M.; Brachert, L.; Mertens, J.; Huizinga, A.; Schallert, B.; Schaber, K.; Vlugt, T.J.H.; Goetheer, E.L.V.

    2013-01-01

    The prevention of emissions of amine species is of high importance for the overall sustainability and performance of Post Combustion CO2 Capture facilities. There is a clear understanding of amine emissions based on volatility in the treated flue gas. Emission via aerosols from Post Combustion CO2 C

  8. Black carbon concentrations from a Tibetan Plateau ice core spanning 1843–1982: recent increases due to emissions and glacier melt

    Directory of Open Access Journals (Sweden)

    M. Jenkins

    2013-10-01

    Full Text Available Black carbon (BC deposited on snow and glacier surfaces can reduce albedo and lead to accelerated melt. An ice core recovered from Guoqu glacier on Mt. Geladaindong and analyzed using a Single Particle Soot Photometer provides the first long-term (1843–1982 record of BC concentrations from the Central Tibetan Plateau. The highest concentrations are observed from 1975–1982, which corresponds to a 2.0-fold and 2.4-fold increase in average and median values, respectively, relative to 1843–1940. BC concentrations post-1940 are also elevated relative to the earlier portion of the record. Causes for the higher BC concentrations include increased regional BC emissions and subsequent deposition, and melt induced enrichment of BC, with the melt potentially accelerated due to the presence of BC at the glacier surface. A qualitative comparison of the BC and Fe (used as a dust proxy records suggests that if changes in the concentrations of absorbing impurities at the glacier surface have influenced recent glacial melt, the melt may be due to the presence of BC rather than dust. Guoqu glacier has received no net ice accumulation since the 1980s, and is a potential example of a glacier where an increase in the equilibrium line altitude is exposing buried high impurity layers. That BC concentrations in the uppermost layers of the Geladaindong ice core are not substantially higher relative to deeper in the ice core suggests that some of the BC that must have been deposited on Guoqu glacier via wet or dry deposition between 1983 and 2005 has been removed from the surface of the glacier, potentially via supraglacial or englacial meltwater.

  9. Assessment of short-term PM2.5-related mortality due to different emission sources in the Yangtze River Delta, China

    Science.gov (United States)

    Wang, Jiandong; Wang, Shuxiao; Voorhees, A. Scott; Zhao, Bin; Jang, Carey; Jiang, Jingkun; Fu, Joshua S.; Ding, Dian; Zhu, Yun; Hao, Jiming

    2015-12-01

    Air pollution is a major environmental risk to health. In this study, short-term premature mortality due to particulate matter equal to or less than 2.5 μm in aerodynamic diameter (PM2.5) in the Yangtze River Delta (YRD) is estimated by using a PC-based human health benefits software. The economic loss is assessed by using the willingness to pay (WTP) method. The contributions of each region, sector and gaseous precursor are also determined by employing brute-force method. The results show that, in the YRD in 2010, the short-term premature deaths caused by PM2.5 are estimated to be 13,162 (95% confidence interval (CI): 10,761-15,554), while the economic loss is 22.1 (95% CI: 18.1-26.1) billion Chinese Yuan. The industrial and residential sectors contributed the most, accounting for more than 50% of the total economic loss. Emissions of primary PM2.5 and NH3 are major contributors to the health-related loss in winter, while the contribution of gaseous precursors such as SO2 and NOx is higher than primary PM2.5 in summer.

  10. Fugitive dust emissions due to car traffic on streets in Vienna; Diffuse Staubemissionen durch den Fahrzeugverkehr auf den Strassen der Stadt Wien

    Energy Technology Data Exchange (ETDEWEB)

    Hoeflinger, W.; Koschutnig, W. [Inst. fuer Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften der Technischen Univ. Wien (Austria)

    2003-10-01

    Fugitive dust emissions resulting from street car traffic in the city of Vienna were determined over a period of 17 months. The emission factor over the measuring period was calculated by measuring the silt content (sL-value) of different selected streets and using the available traffic count data. It is shown, that strewing crushed stone on streets in winter has a major influence on fugitive dust emission. A comparison of these emission factors with ambient air measuring data over the same measuring period shows parallel curves, which shows that resuspension of the dust deposited on streets affects air quality in the city of Vienna. (orig.)

  11. Influence on the oxidative potential of a heavy-duty engine particle emission due to selective catalytic reduction system and biodiesel blend.

    Science.gov (United States)

    Godoi, Ricardo H M; Polezer, Gabriela; Borillo, Guilherme C; Brown, Andrew; Valebona, Fabio B; Silva, Thiago O B; Ingberman, Aline B G; Nalin, Marcelo; Yamamoto, Carlos I; Potgieter-Vermaak, Sanja; Penteado Neto, Renato A; de Marchi, Mary Rosa R; Saldiva, Paulo H N; Pauliquevis, Theotonio; Godoi, Ana Flavia L

    2016-08-01

    Although the particulate matter (PM) emissions from biodiesel fuelled engines are acknowledged to be lower than those of fossil diesel, there is a concern on the impact of PM produced by biodiesel to human health. As the oxidative potential of PM has been suggested as trigger for adverse health effects, it was measured using the Electron Spin Resonance (OP(ESR)) technique. Additionally, Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF) was employed to determine elemental concentration, and Raman Spectroscopy was used to describe the amorphous carbon character of the soot collected on exhaust PM from biodiesel blends fuelled test-bed engine, with and without Selective Catalytic Reduction (SCR). OP(ESR) results showed higher oxidative potential per kWh of PM produced from a blend of 20% soybean biodiesel and 80% ULSD (B20) engine compared with a blend of 5% soybean biodiesel and 95% ULSD (B5), whereas the SCR was able to reduce oxidative potential for each fuel. EDXRF data indicates a correlation of 0.99 between concentration of copper and oxidative potential. Raman Spectroscopy centered on the expected carbon peaks between 1100cm(-1) and 1600cm(-1) indicate lower molecular disorder for the B20 particulate matter, an indicative of a more graphitic carbon structure. The analytical techniques used in this study highlight the link between biodiesel engine exhaust and increased oxidative potential relative to biodiesel addition on fossil diesel combustion. The EDXRF analysis confirmed the prominent role of metals on free radical production. As a whole, these results suggest that 20% of biodiesel blends run without SCR may pose an increased health risk due to an increase in OH radical generation. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Enhanced photoluminescence property and broad color emission of ZnGa2O4 phosphor due to the synergistic role of Eu3+ and carbon dots

    Science.gov (United States)

    Huo, Qiuyue; Tu, Weixia; Guo, Lin

    2017-10-01

    ZnGa2O4 phosphors co-composited with nanoscale carbon dots (CDs) and Eu3+ were presented for the tunable color emission. Novel single phase CDs or/and Eu3+ composited ZnGa2O4 phosphors were synthesized by microwave hydrothermal method and their optical properties were investigated. The ZnGa2O4 phosphors composited with CDs exhibited an intense broad blue light emission at 421 nm and a more enhanced photoluminescence intensity than those without CDs. The Eu3+ composited ZnGa2O4 phosphors gave an ideal red color emission. The CDs/Eu3+ co-composited ZnGa2O4 phosphors exhibited a wide emission band peak at 450 nm and narrow emission peak at 618 nm. Furthermore, the tunable color emissions of CDs/Eu3+ co-composited ZnGa2O4 phosphors from blue to the white light region, and then to red were obtained with the increasing Eu3+ concentration, which can be a promising single phased phosphor candidate in light emitting diodes. Broadly tunable emission single phased phosphor is tuned firstly through the synergistic role of the non-metal element and the rare earth metal ions.

  13. A shift in emission time profiles of fossil fuel combustion due to energy transitions impacts source receptor matrices for air quality.

    Science.gov (United States)

    Hendriks, Carlijn; Kuenen, Jeroen; Kranenburg, Richard; Scholz, Yvonne; Schaap, Martijn

    2015-03-01

    Effective air pollution and short-lived climate forcer mitigation strategies can only be designed when the effect of emission reductions on pollutant concentrations and health and ecosystem impacts are quantified. Within integrated assessment modeling source-receptor relationships (SRRs) based on chemistry transport modeling are used to this end. Currently, these SRRs are made using invariant emission time profiles. The LOTOS-EUROS model equipped with a source attribution module was used to test this assumption for renewable energy scenarios. Renewable energy availability and thereby fossil fuel back up are strongly dependent on meteorological conditions. We have used the spatially and temporally explicit energy model REMix to derive time profiles for backup power generation. These time profiles were used in LOTOS-EUROS to investigate the effect of emission timing on air pollutant concentrations and SRRs. It is found that the effectiveness of emission reduction in the power sector is significantly lower when accounting for the shift in the way emissions are divided over the year and the correlation of emissions with synoptic situations. The source receptor relationships also changed significantly. This effect was found for both primary and secondary pollutants. Our results indicate that emission timing deserves explicit attention when assessing the impacts of system changes on air quality and climate forcing from short lived substances.

  14. Small global effect on terrestrial net primary production due to increased fossil fuel aerosol emissions from East Asia during the last decade.

    Science.gov (United States)

    O'Sullivan, Michael; Rap, Alex; Reddington, Carly; Spracklen, Dominick; Buermann, Wolfgang

    2016-04-01

    The global terrestrial carbon sink has increased since the start of this century at a time of rapidly growing carbon dioxide emissions from fossil fuel burning. Here we test the hypothesis that increases in atmospheric aerosols from fossil fuel burning have increased the diffuse fraction of incoming solar radiation and the efficiency of photosynthesis leading to increased plant carbon uptake. Using a combination of atmospheric and biospheric models, we find that changes in diffuse light associated with fossil fuel aerosol emission accounts for only 2.8% of the increase in global net primary production (1.221 PgC/yr) over the study period 1998 to 2007. This relatively small global signal is however a result of large regional compensations. Over East Asia, the strong increase in fossil fuel emissions contributed nearly 70% of the increased plant carbon uptake (21 TgC/yr), whereas the declining fossil fuel aerosol emissions in Europe and North America contributed negatively (-16% and -54%, respectively) to increased plant carbon uptake. At global scale, we also find the CO2 fertilization effect on photosynthesis to be the dominant driver of increased plant carbon uptake, in line with previous studies. These results suggest that further research into alternative mechanisms by which fossil fuel emissions could increase carbon uptake, such as nitrogen deposition and carbon-nitrogen interactions, is required to better understand a potential link between the recent changes in fossil fuel emissions and terrestrial carbon uptake.

  15. Declining risk of ozone impacts on vegetation in Europe 1990–2050 due to reduced precursor emissions in a changed climate

    Directory of Open Access Journals (Sweden)

    J. Klingberg

    2014-01-01

    Full Text Available The impacts of climate change and changes in ozone precursor emission on ozone exposure (AOT40 of the vegetation in Europe were investigated. In addition, meteorological conditions influencing stomatal uptake of ozone were analysed to find out if climate change is likely to affect the risk for ozone damage to vegetation. Climate simulations based on the IPCC SRES A1B scenario were combined with ozone precursor emission changes from the RCP4.5 scenario and used as input to the Eulerian Chemical Transport Model MATCH from which projections of ozone concentrations were derived. Provided that the climate projections are realistic and the emission reductions of the emission scenario are undertaken, the ozone exposure of vegetation over Europe will be significantly reduced between the two time periods 1990–2009 and 2040–2059. This decline in AOT40 is larger than the reduction in average ozone concentrations. The reduction is driven by the emission reductions assumed by the RCP4.5 emission scenario, rather than changes in the climate. Higher temperatures in a future climate will result in a prolonged growing season over Europe as well as larger temperature sums during the growing season. Both the extended growing season and higher temperatures may enhance ozone uptake by plants in colder parts of Europe. The future climate suggested by the regional climate model will be dryer in terms of higher vapour pressure deficit (VPD and lower soil moisture in southern Europe, which may reduce ozone uptake. VPD and soil moisture was not projected to change in north and north-west Europe to an extent that would influence ozone uptake by vegetation. This study shows that substantial reductions of ozone precursor emissions have the potential to strongly reduce the risk for ozone effects on vegetation, even if concurrent climate change promotes ozone formation.

  16. k-space drift due to the density variation as a cause of electromagnetic emission generation of type III solar radio bursts by a non-gyrotropic electron beam

    Science.gov (United States)

    Tsiklauri, David; Schmitz, Holger

    2013-04-01

    , in long term evolution of electromagnetic emission generation of type III solar radio bursts. The following improvements and progress in understanding of the radio emission mechanism are made: (i) Improved numerical simulations with larger spatial domain and longer end-simulation times; (ii) The electron beam injection on a density plateau followed by a decreasing density gradient that mimics the Sun-earth system; (iii) Consideration of a ring and shifted ring electron initial velocity distribution functions; (iv) The role of the k-space drift in the radio emission; (v) Estimation of the ECM growth rate and its role in the emission generation. It is worthwhile to note that Ref.[3] proposed mode coupling on the density gradient as a source of radio emission as opposed to the k-space drift advocated in the present work. The situation is analogous to the auroral waves emitted near the plasma frequency in Earth auroral ionosphere [A. Layden, I. H. Cairns, P. A. Robinson, and J. LaBelle, J. Geophys. Res. 116, A12328 (2011)]. [1] D. Tsiklauri, "An alternative to the plasma emission model: Particle-In-Cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts", Physics of Plasmas 18, 052903 (2011) [2] R. Pechhacker, D. Tsiklauri, "The effect of electron beam pitch angle and density gradient on solar type III radio bursts", Phys. Plasmas 19, 112903 (2012) [3] R. Pechhacker, D. Tsiklauri, "Electron cyclotron maser emission mode coupling to the z-mode on a longitudinal density gradient in the context of solar type III bursts", Phys. Plasmas 19, 110702 (2012) [4] H. Schmitz, D. Tsiklauri, "k-space drift due to the density variation as a cause of electromagnetic emission generation of type III solar radio bursts by a non-gyrotropic electron beam", Phys. Plasmas, in preparation, (2013)

  17. A shift in emission time profiles of fossil fuel combustion due to energy transitions impacts source receptor matrices for air quality

    NARCIS (Netherlands)

    Hendriks, C.; Kuenen, J.; Kranenburg, R.; Scholz, Y.; Schaap, M.

    2015-01-01

    Effective air pollution and short-lived climate forcer mitigation strategies can only be designed when the effect of emission reductions on pollutant concentrations and health and ecosystem impacts are quantified. Within integrated assessment modeling source-receptor relationships (SRRs) based on ch

  18. A shift in emission time profiles of fossil fuel combustion due to energy transitions impacts source receptor matrices for air quality

    NARCIS (Netherlands)

    Hendriks, C.; Kuenen, J.; Kranenburg, R.; Scholz, Y.; Schaap, M.

    2015-01-01

    Effective air pollution and short-lived climate forcer mitigation strategies can only be designed when the effect of emission reductions on pollutant concentrations and health and ecosystem impacts are quantified. Within integrated assessment modeling source-receptor relationships (SRRs) based on ch

  19. Variability of GeV gamma-ray emission in QSO B0218+357 due to microlensing on intermediate size structures

    Science.gov (United States)

    Sitarek, J.; Bednarek, W.

    2016-06-01

    Strong gravitational lensing leads to an occurrence of multiple images, with different magnifications, of a lensed source. Those magnifications can in turn be modified by microlensing on smaller mass scales within the lens. Recently, measurements of the changes in the magnification ratio of the individual images have been proposed as a powerful tool for estimation of the size and velocity of the emission region in the lensed source. The changes of the magnification ratios in blazars PKS1830-211 and QSO B0218+357, if interpreted as caused by a microlensing on individual stars, put strong constraints on those two variables. These constraints are difficult to accommodate with the current models of gamma-ray emission in blazars. In this paper we study if similar changes in the magnification ratio can be caused by microlensing on intermediate size structures in the lensing galaxy. We investigate in details three classes of possible lenses: globular clusters (GCs), open clusters (OCs) and giant molecular clouds (GMCs). We apply this scenario to the case of QSO B0218+357. Our numerical simulations show that changes in magnifications with similar time-scales can be obtained for relativistically moving emission regions with sizes up to 0.01 pc in the case of microlensing on the cores of GCs or clumps in GMCs. From the density of such structures in spiral galaxies we estimate however that lensing in GMCs would be more common.

  20. A practical approach to estimate emission rates of indoor air pollutants due to the use of personal combustible products based on small-chamber studies.

    Science.gov (United States)

    Szulejko, Jan E; Kim, Ki-Hyun

    2016-02-01

    As emission rates of airborne pollutants are commonly measured from combusting substances placed inside small chambers, those values need to be re-evaluated for the possible significance under practical conditions. Here, a simple numerical procedure is investigated to extrapolate the chamber-based emission rates of formaldehyde that can be released from various combustible sources including e-cigarettes, conventional cigarettes, or scented candles to their concentration levels in a small room with relatively poor ventilation. This simple procedure relies on a mass balance approach by considering the masses of pollutants emitted from source and lost through ventilation under the assumption that mixing occurs instantaneously in the room without chemical reactions or surface sorption. The results of our study provide valuable insights into re-evaluation procedure of chamber data to allow comparison between extrapolated and recommended values to judge the safe use of various combustible products in confined spaces. If two scented candles with a formaldehyde emission rate of 310 µg h(-1) each were lit for 4 h in a small 20 m(3) room with an air change rate of 0.5 h(-1), then the 4-h (candle lit) and 8-h (up to 8 h after candle lighting) TWA [FA] were determined to be 28.5 and 23.5 ppb, respectively. This is clearly above the 8-h NIOSH recommended exposure limit (REL) time weighted average of 16 ppb.

  1. CO{sub 2} emissions resulting of the energy in the world in 2002-2003; Emissions de CO{sub 2} dues a l'energie dans le monde en 2002-2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-11-15

    This document provides statistical data on the carbon dioxide emissions, corrected and not from the climate, for the years 2002-2003. The countries concerned are the following continents: north America, south America, Europe, Africa, Middle-East, Far-East, Oceania. (A.L.B.)

  2. Red-shift of the photoluminescent emission peaks of CdTe quantum dots due to the synergistic interaction with carbon quantum dot mixtures

    Science.gov (United States)

    Pelayo, E.; Zazueta, A.; López-Delgado, R.; Saucedo, E.; Ruelas, R.; Ayón, A.

    2016-11-01

    We report the relatively large red-shift effect observed in down-shifting carbon quantum dots (CQDs) that is anticipated to have a positive impact on the power conversion efficiency of solar cells. Specifically, with an excitation wavelength of 390 nm, CQDs of different sizes, exhibited down-shifted emission peaks centered around 425 nm. However, a solution comprised of a mixture of CQDs of different sizes, was observed to have an emission peak red-shifted to 515 nm. The effect could arise when larger carbon quantum dots capture the photons emitted by their smaller counterparts followed by the subsequent re-emission at longer wavelengths. Furthermore, the red-shift effect was also observed in CdTe QDs when added to a solution with the aforementioned mixture of Carbon QDs. Thus, whereas a solution solely comprised of a collection of CdTe QDs of different sizes, exhibited a down-shifted photoluminescence centered around 555 nm, the peak was observed to be further red-shifted to 580 nm when combined with the solution of CQDs of different sizes. The quantum dot characterization included crystal structure analysis as well as photon absorption and photoluminescence wavelengths. Subsequently, the synthesized QDs were dispersed in a polymeric layer of poly-methyl-methacrylate (PMMA) and incorporated on functional and previously characterized solar cells, to quantify their influence in the electrical performance of the photovoltaic structures. We discuss the synthesis and characterization of the produced Carbon and CdTe QDs, as well as the observed improvement in the power conversion efficiency of the fabricated photovoltaic devices.

  3. Variability of GeV gamma-ray emission in QSO B0218+357 due to microlensing on intermediate size structures

    CERN Document Server

    Sitarek, Julian

    2016-01-01

    Strong gravitational lensing leads to an occurrence of multiple images, with different magnifications, of a lensed source. Those magnifications can in turn be modified by microlensing on smaller mass scales within the lens. Recently, measurements of the changes in the magnification ratio of the individual images have been proposed as a powerful tool for estimation of the size and velocity of the emission region in the lensed source. The changes of the magnification ratios in blazars PKS1830-211 and QSO B0218+357, if interpreted as caused by a microlensing on individual stars, put strong constraints on those two variables. These constraints are difficult to accommodate with the current models of gamma-ray emission in blazars. In this paper we study if similar changes in the magnification ratio can be caused by microlensing on intermediate size structures in the lensing galaxy. We investigate in details three classes of possible lenses: globular clusters (GC), open clusters (OC) and giant molecular clouds (GMC)...

  4. Emission enhancement in indium zinc oxide(IZO)/Ag/IZO sandwiched structure due to surface plasmon resonance of thin Ag film

    Science.gov (United States)

    Kiba, Takayuki; Yanome, Kazuki; Kawamura, Midori; Abe, Yoshio; Kim, Kyung Ho; Takayama, Junichi; Murayama, Akihiro

    2016-12-01

    We report on a photoluminescence (PL) enhancement in IZO/Ag/IZO sandwiched structure via surface plasmonic effects of 14 nm-thick Ag film. In the presence of Ag thin film, the 2-8-fold enhancement was observed for the broad PL around 2.34 eV, which can be originated from defect states in amorphous IZO film. The results of time-resolved PL spectra suggested that the increase in radiative recombination rate, and the maximum Purcell factor of 19 was estimated from the analysis of the PL decay profiles. The comparison between the results of static- and dynamic-PL measurement suggests that the non-radiative process after the excitation of the surface plasmon of the silver film also affects the total efficiency of the emission enhancement.

  5. H- and He-like Charge-Exchange Induced X-ray Emission due to Ion Collisions with H, He, and H2

    Science.gov (United States)

    Cumbee, Renata; Mullen, Patrick; Miller, Ansley; Lyons, David; Shelton, Robin L.; Schultz, David R.; Stancil, Phillip C.; Leutenegger, Maurice A.

    2017-08-01

    When a hot plasma collides with a cold neutral gas interactions occur between the microscopic constituents including charge exchange (CX). CX is a process in which an electron can be transferred from a neutral atom or molecule into an excited energy level of an ion. Following this transfer, the excited electron relaxes to lower energy levels, emitting X-rays. This process has been established as a primary source of X-ray emission within our solar system, such as when the solar wind interacts with cometary and planetary atmospheres, and outside of our solar system, such as in the hot outflows of starburst galaxies.Since the CX X-ray emission spectrum varies greatly with collision velocity, it is critical that realistic CX data are included in X-ray spectral models of astrophysical environments in which CX might be significant in order to correctly estimate the ion abundance and plasma velocities. Here, line ratios and spectra are computed using theoretical CX cross sections obtained with the multi-channel Landau-Zener, atomic-orbital close-coupling, and classical-trajectory Monte Carlo methods for a variety of collision energies relevant to various astrophysical environments. Collisions of bare and H-like C, N, O, Ne, Mg, Al, Si, P, S, and Cl ions are shown with H, He, and H2 as the neutral collision targets. An X-ray model using line ratios for C-Si ions is then performed within XSPEC for a region of the Cygnus Loop supernova remnant for 8 collision energies in order to highlight the variation in CX spectral models with collision energy.R. Cumbee’s research was partially supported by an appointment to the NASA Postdoctoral Program at NASA GSFC, administered by Universities Space Research Association under contract with NASA. Work at UGA was partially supported by NASA grants NNX09AC46G and NNG09WF24I.

  6. Intrinsic spatial resolution limitations due to differences between positron emission position and annihilation detection localization; Limitacoes da resolucao espacial intrinseca devido as diferencas entre a posicao da emissao do positron e a deteccao da localizacao de aniquilacao

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Pedro; Malano, Francisco; Valente, Mauro, E-mail: valente@famaf.unc.edu.ar [Universidad Nacional de Cordoba, Cordoba (Argentina). Fac. de Matematica, Astronomia y Fisica (FaMAF)

    2012-07-01

    Since its successful implementation for clinical diagnostic, positron emission tomography (PET) represents the most promising medical imaging technique. The recent major growth of PET imaging is mainly due to its ability to trace the biologic pathways of different compounds in the patient's body, assuming the patient can be labeled with some PET isotope. Regardless of the type of isotope, the PET imaging method is based on the detection of two 511-keV gamma photons being emitted in opposite directions, with almost 180 deg between them, as a consequence of electron-positron annihilation. Therefore, this imaging method is intrinsically limited by random uncertainties in spatial resolutions, related with differences between the actual position of positron emission and the location of the detected annihilation. This study presents an approach with the Monte Carlo method to analyze the influence of this effect on different isotopes of potential implementation in PET. (author)

  7. Tibetan Plateau Geladaindong black carbon ice core record (1843–1982: Recent increases due to higher emissions and lower snow accumulation

    Directory of Open Access Journals (Sweden)

    Jenkins Matthew

    2016-09-01

    Full Text Available Black carbon (BC deposited on snow and glacier surfaces can reduce albedo and lead to accelerated melt. An ice core recovered from Guoqu glacier on Mt. Geladaindong and analyzed using a Single Particle Soot Photometer (SP2 provides the first long-term (1843–1982 record of BC from the central Tibetan Plateau. Post 1940 the record is characterized by an increased occurrence of years with above average BC, and the highest BC values of the record. The BC increase in recent decades is likely caused by a combination of increased emissions from regional BC sources, and a reduction in snow accumulation. Guoqu glacier has received no net ice accumulation since the 1980s, and is a potential example of a glacier where an increase in the equilibrium line altitude is exposing buried high impurity layers. That BC concentrations in the uppermost layers of the Geladaindong ice core are not substantially higher relative to deeper in the ice core suggests that some of the BC that must have been deposited on Guoqu glacier via wet or dry deposition between 1983 and 2005 has been removed from the surface of the glacier, potentially via supraglacial or englacial meltwater.

  8. MUSE Deep-Fields: The Lya Luminosity Function in the Hubble Deep Field South at 2.91 < z < 6.64

    CERN Document Server

    Drake, Alyssa B; Blaizot, Jeremy; Wisotzki, Lutz; Herenz, Edmund Christian; Garel, Thibault; Richard, Johan; Bacon, Roland; Bina, David; Cantalupo, Sebastiano; Contini, Thierry; Brock, Mark den; Hashimoto, Takuya; Marino, Raffaella Anna; Pello, Roser; Schaye, Joop; Schmidt, Kasper B

    2016-01-01

    We present the first estimate of the Ly{\\alpha} luminosity function using blind spectroscopy from the Multi Unit Spectroscopic Explorer, MUSE, in the Hubble Deep Field South. Using automatic source-detection software, we assemble a homogeneously-detected sample of 59 Ly{\\alpha} emitters covering a flux range of -18.0 < log10 (F) < -16.3 (erg s^-1 cm^-2), corresponding to luminosities of 41.4 < log10 (L) < 42.8 (erg s^-1). As recent studies have shown, Ly{\\alpha} fluxes can be underestimated by a factor of two or more via traditional methods, and so we undertake a careful assessment of each object's Ly{\\alpha} flux using a curve-of-growth analysis to account for extended emission. We describe our self-consistent method for determining the completeness of the sample, and present an estimate of the global Ly{\\alpha} luminosity function between redshifts 2.91 < z < 6.64 using the 1/Vmax estimator. We find the luminosity function is higher than many number densities reported in the literature by ...

  9. Myocardial oxidative metabolism is increased due to haemodynamic overload in patients with aortic valve stenosis: assessment using {sup 11}C-acetate positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Naya, Masanao; Chiba, Satoru; Iwano, Hiroyuki; Yamada, Satoshi; Tsutsui, Hiroyuki [Hokkaido University Graduate School of Medicine, Department of Cardiovascular Medicine, Sapporo (Japan); Katoh, Chietsugu [Hokkaido University Graduate School of Medicine, Department of Health Science, Sapporo (Japan); Manabe, Osamu; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Yoshinaga, Keiichiro [Hokkaido University Graduate School of Medicine, Department of Molecular Imaging, Sapporo (Japan); Matsui, Yoshiro [Hokkaido University Graduate School of Medicine, Department of Cardiovascular Surgery, Sapporo (Japan)

    2010-12-15

    The relationship between myocardial oxidative metabolism and pressure overload in aortic valve stenosis (AS) is not fully elucidated. We identified the determinants of myocardial oxidative metabolism by measuring its changes after aortic valve replacement (AVR) in patients with AS. Myocardial {sup 11}C-acetate clearance rate constant (Kmono), an index of oxidative metabolism, was measured non-invasively by using positron emission tomography in 16 patients with moderate to severe AS and 7 healthy controls. The severity of AS was assessed by echocardiography. Of 16 patients, 5 were reexamined at 1 month after AVR. Kmono was significantly higher in patients with AS than healthy controls by 42% (0.068 {+-} 0.014 vs 0.048 {+-} 0.007/min, p < 0.01). Kmono was significantly correlated with age (r = 0.58, p < 0.01), left ventricular (LV) mass index (r = 0.61, p < 0.01) and estimated systolic LV pressure (r = 0.81, p < 0.001) measured by echocardiography. By multivariate analysis, estimated LV systolic pressure was an independent predictor of Kmono ({beta} = 0.93, p < 0.01). After AVR, Kmono (from 0.075 {+-} 0.012 to 0.061 {+-} 0.014/min, p = 0.043) and LV mass index (from 183 {+-} 49 to 124 {+-} 41 g/ml{sup 2}, p = 0.043) were significantly decreased despite no significant changes in rate-pressure product. Myocardial oxygen metabolism was increased in patients with AS, which was decreased after AVR. The increased myocardial oxidative metabolism in AS was largely attributable to the pressure overload of the LV. (orig.)

  10. Oxidative damage-related genes AKR1C3 and OGG1 modulate risks for lung cancer due to exposure to PAH-rich coal combustion emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Q.; Mumford, J.L.; Shen, M.; DeMarini, D.M.; Bonner, M.R.; He, X.Z.; Yeager, M.; Welch, R.; Chanock, S.; Tian, L.W.; Chapman, R.S.; Zheng, T.Z.; Keohavong, P.; Caporaso, N.; Rothman, N. [NCI, Bethesda, MD (US). Division of Epidemiology and Genetics

    2004-11-01

    Lung cancer rates among men and particularly among women, almost all of whom are non-smokers, in Xuan Wei County, China are among the highest in China and have been causally associated with exposure to indoor smoky coal emissions that contain very high levels of polycyclic aromatic hydrocarbons (PAHs). As such, this population provides a unique opportunity to study the pathogenesis of PAH-induced lung cancer that is not substantially influenced by the large number of other carcinogenic constituents of tobacco smoke. Aldo-keto reductases (AKRs) activate PAH dihydrodiols to yield their corresponding reactive and redox-active o-quinones, which can then generate reactive oxygen species that cause oxidative DNA damage. We therefore examined the association between single nucleotide polymorphisms (SNPs) in four genes (AKR1C3-Gln5His, NQO1-Pro187Ser, MnSOD-Val16Ala and OGG1-Ser326Cys) that play a role in the generation, prevention or repair of oxidative damage and lung cancer risk in a population-based, case-control study of 119 cases and 113 controls in Xuan Wei, China. The AKR1C3-Gln/Gln genotype was associated with a 1.84-fold increased risk and the combined OGG1-Cys/Cys and Ser/Cys genotypes were associated with a 1.93-fold increased risk of lung cancer. Subgroup analysis revealed that the effects were particularly elevated among women who had relatively high cumulative exposure to smoky coal. SNPs in MnSOD and NQO1 were not associated with lung cancer risk. These results suggest that SNPs in the oxidative stress related-genes AKR1C3 and OGG1 may play a role in the pathogenesis of lung cancer in this population, particularly among heavily exposed women.

  11. Examination of the presynaptic dopaminergic system using positron emission tomography in a family with autosomal dominant parkinsonism and dementia due to pallido-ponto-nigral degeneration (PPNO)

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, M. [Neurodegenerative Disorders Centre, Univ. of British Columbia, Vancouver, BC (Canada)]|[Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Wszolek, Z.K. [Neurodegenerative Disorders Centre, Univ. of British Columbia, Vancouver, BC (Canada)]|[Section of Neurology, Univ. of Nebraska Medical Center, Omaha, NE (United States); Pfeiffer, R.F. [Section of Neurology, Univ. of Nebraska Medical Center, Omaha, NE (United States); Calne, D.B. [Neurodegenerative Disorders Centre, Univ. of British Columbia, Vancouver, BC (Canada)

    1993-12-31

    We report positron emission tomography (PET) examinations of presynaptic nigrostriatal dopaminergic function in a large family with an autosomal dominant neuro-degenerative disorder characterized pathologically by pallido-ponto-nigral degeneration, and clinically by parkinsonism, dystonia, paresis of conjugate gaze, apraxia of eyelid opening and closing, pyramidal tract dysfunction, and urinary incontinence. Dopaminergic function was studied and quantified with [{sup 18}F]-L-6-fluorodopa (6 FD) and PET in five affected patients, 13 individuals at-risk, and 15 similarly aged controls. The rate constant K{sub i} (mL/striatum/min) for 6 FD was decreased in all patients. None of the individuals at risk had reduced 6 FD uptake. In fact, three of them had increased values. Repeat scans have revealed a fall in 6 FD uptake in two out of the three with initially high constants. This may reflect a preclinical stage of involvement, but longer observation is necessary. (orig.) [Deutsch] Wir berichten ueber Untersuchungen der praesynaptischen dopaminergen Funktion mit der Positronenemissionstomographie bei einer grossen Familie mit autosomal-dominant vererbtem Parkinsonismus und Demenz. Die Erkrankung ist pathologisch-anatomisch gekennzeichnet durch eine pallido-ponto-nigrale Degeneration. Klinisch bestehen ein Parkinsonismus, Dystonien, eine Apraxie der Augenoeffnung und -schliessung, pyramidale Dysfunktionen und eine Harninkontinenz. Die praesynaptische dopaminerge Funktion wurde untersucht und quantifiziert mittels [{sup 18}F]-L-6-Fluorodopa (6FD) PET bei fuenf erkrankten Patienten, 13 Risikopatienten und 15 Kontrollpersonen vergleichbaren Alters. Die Transportkonstante K{sub i} (ml/Striatum/min) fuer die striatale Aufnahme des Radiotracers war bei allen erkrankten Patienten erniedrigt. Von den 13 Risikopatienten hatte keiner eine reduzierte Aufnahme von 6FD. Drei Risikopatienten zeigten sogar Werte fuer K{sub i}, die oberhalb des Referenzbereiches der Kontrollpersonen lagen

  12. KASAPOĞLU ÇENGEL, Hülya Kırgız Türkçesi Grameri Ses ve Şekil Bilgisi, Akçağ/700, Ankara, 2005, 424 s, ISBN 975-338-687-7.

    OpenAIRE

    KINACI, Cemile

    2007-01-01

    gözden geçirildi inde, Prof. Dr. Hülya Kasapo lu Çengel’in bu çalõ masõnõn ala- nõndaki ilk örneklerden biri oldu u görülür. Eser, Kõrgõz Türkçesinin ses ve e- kil bilgisini derli toplu ve ayrõntõlõ ekilde vermektedir. Kõrgõz Türkçesi Grameri sadece Türkoloji çevrelerinin de il; Kõrgõz Türkçesini ö renmek isteyenlerin de ba vuru kaynaklarõndan biri niteli indedir

  13. KASAPOĞLU ÇENGEL, Hülya Kırgız Türkçesi Grameri Ses ve Şekil Bilgisi, Akçağ/700, Ankara, 2005, 424 s, ISBN 975-338-687-7.

    OpenAIRE

    KINACI, Cemile

    2007-01-01

    gözden geçirildi inde, Prof. Dr. Hülya Kasapo lu Çengel’in bu çalõ masõnõn ala- nõndaki ilk örneklerden biri oldu u görülür. Eser, Kõrgõz Türkçesinin ses ve e- kil bilgisini derli toplu ve ayrõntõlõ ekilde vermektedir. Kõrgõz Türkçesi Grameri sadece Türkoloji çevrelerinin de il; Kõrgõz Türkçesini ö renmek isteyenlerin de ba vuru kaynaklarõndan biri niteli indedir

  14. External costs due to congestion, accidents, energy consumption and emissions before and into the economic crisis: Pilot study along selected roadways of Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    Sotiriou Matina

    2015-01-01

    Full Text Available Prior to the economic crisis, forecasts indicated a continuous increase of traffic in European cities, highlighting the need of a policy to alleviate the external impacts of transport. The crisis, however, generated pressures on all sectors of activity, with transport being an indicative example. The reduction of income and employment, the increased vehicle maintenance and renewal costs and the transport related taxation seem to affect the transport system and its external impacts. Thus, taking for granted that Europe will eventually achieve “sustainable recovery” from the crisis, the current period presents an opportunity for promoting sustainable mobility policies and interventions in the most affected by the crisis European cities. Towards this goal, it is essential to capitalise on contemporary techniques for the monitoring of changes in transport external costs. The purpose of the paper is the development of a methodology for the estimation of external costs due to congestion, air pollution, climate change and accidents, based on road traffic data. The methodology is applied along road arteries in Thessaloniki for the period “before and after” the emergence of the crisis. As a result, an overall decrease in external costs is observed, creating an unforeseen “surplus” for the society during the crisis.

  15. 城市居住区内家庭直接能耗碳排放差异研究%Research on the Difference in Carbon Emissions Due to Direct Household Energy Consumption in the Same Urban Residential Community

    Institute of Scientific and Technical Information of China (English)

    张艳; 秦耀辰

    2012-01-01

    家庭能源消费对环境的影响已经成为可持续发展领域热点研究课题之一.基于微观视角,采用多段抽取的方法从南阳市一商业居住区内选取128户家庭进行住户的调研,针对具有不同的家庭规模、家庭收入、房屋所有权、家庭成员节能意识及能源知识掌握程度的家庭,分别分析了其直接能耗CO2排放量和结构上的差异.用多元逐步回归的方法,得到了家庭成员节能意识强烈度、家庭人口、家庭成年人平均文化程度、能源知识掌握程度等是造成同一居住区内家庭CO2排放差异的显著性因子,家庭成员节能意识的强烈程度、能源知识的掌握程度与家庭直接能耗CO2排放量呈负相关,因此,加强对居民的能源知识的普及和节能意识的强化可以降低家庭直接能耗的CO2排放量.%The impact on the environment due to household energy consumption has become one of the hotspot issues in the field of sustainable development. In order to study the difference in carbon emissions due to direct household energy consumption in the same urban residential community, 128 households are selected from a commercial residential community by multy selection. The difference in households CO2 emissions due to direct energy consumption are analyzed according to the different family numbers, different income, house droit, energy saving consciousness, energy knowledge. The analysis shows that energy saving consciousness, family numbers, family income, energy knowledge are the most important sources of household CO2 emissions due to direct energy consumption.

  16. PAH Emission Within Lyman Alpha Blobs

    CERN Document Server

    Colbert, James W; Teplitz, Harry; Francis, Paul; Palunas, Povilas; Williger, Gerard M; Woodgate, Bruce

    2010-01-01

    We present Spitzer observations of Lya Blobs (LAB) at z=2.38-3.09. The mid-infrared ratios (4.5/8um and 8/24um) indicate that ~60% of LAB infrared counterparts are cool, consistent with their infrared output being dominated by star formation and not active galactic nuclei (AGN). The rest have a substantial hot dust component that one would expect from an AGN or an extreme starburst. Comparing the mid-infrared to submillimeter fluxes (~850um or rest frame far infrared) also indicates a large percentage (~2/3) of the LAB counterparts have total bolometric energy output dominated by star formation, although the number of sources with sub-mm detections or meaningful upper limits remains small (~10). We obtained Infrared Spectrograph (IRS) spectra of 6 infrared-bright sources associated with LABs. Four of these sources have measurable polycyclic aromatic hydrocarbon (PAH) emission features, indicative of significant star formation, while the remaining two show a featureless continuum, indicative of infrared energy...

  17. Les émissions par perméabilité à travers les canalisations des véhicules automobiles Emissions Due to Permeation Through the Vehicule Fuel Lines

    Directory of Open Access Journals (Sweden)

    Dewimille B.

    2006-12-01

    Full Text Available Un des objectifs de la politique environnementale de l'Union européenne est de réduire les émissions des véhicules automobiles. Les normes Euro 96 et Euro 2000 s'intéressent en particulier aux émissions par évaporation dues à la perméation du carburant à travers les matériaux polymères. Dans ce papier, nous exposons la méthode d'essai des lignes de carburant développée à l'IFP avec PSA et Renault. Nous présentons également des résultats obtenus avec divers types de canalisations et plusieurs fluides d'essai. Au vu de ces résultats et de la sévérité des nouvelles normes, les équipementiers et les fournisseurs de matières doivent développer de nouvelles solutions afin d'améliorer la résistance à la perméation. The aim of the environmental policy of the European Union is to reduce the automotive hydrocarbon emissions. The Euro 96 and future Euro 2000 standards are particularly dealing with the emissions due to fuel permeation through polymeric materials. In this paper, the testing procedure for fuel lines developed at IFP, PSA, and Renault, is described. Results obtained with various types of fuel lines and several fuels are detailed. According to these results and to the new stringent standards, equipment and material suppliers will have to develop new solutions with improved permeation resistance.

  18. Observable Signatures of the low-z Circum-Galactic and Inter-Galactic Medium : UV Line Emission in Simulations

    CERN Document Server

    Frank, S; Vibert, D; Milliard, B; Popping, A; Blaizot, J; Courty, S; Deharveng, J M; Peroux, C; Teyssier, R; Martin, C D

    2011-01-01

    We present for the first time predictions for UV line emission of intergalactic and circumgalactic gas from Adaptive Mesh Resolution (AMR) Large Scale Structure (LSS) simulations at redshifts 0.3Lya, OVI and CIV) there is a clear bimodality in the type of objects : the overwhelming majority of flux stems from discrete, compact sources, while a much larger volume fraction is filled by more tenuous gas. We characterise both object types with regard to number density, physical size and shape, brightness, luminosity, velocity structure, mass, temperature, ionisation state, and metal content. Degrading AMR grids to characteristic resolutions of available (such as FIREBall) or foreseeable instrumentation, allows to assess which inferences can be drawn from currently possible observations, and set foundations to prepare observing strategies for future missions. In general, the fain...

  19. In Search of the Dark Ages -- An Experimental Challenge

    CERN Document Server

    Bland-Hawthorn, J

    2004-01-01

    Most direct source detections beyond z~7 are likely to arise from wide-field narrowband surveys of Ly-a emission in the J band. For this to be true, the Ly-a emission must somehow escape from compact star-forming regions (CSR) presumably associated with massive haloes. Since the Ly-a escape fraction is <10% from an emitting region of size roughly 1 kpc, these objects will be difficult to find and hard to detect. For CSR sources, existing large-format IR arrays are close to ideal in terms of their noise characteristics for conducting "wide-field" narrowband surveys where pixel sizes are 0.1" or larger. However, we stress that Ly-a can also arise from external large-scale shocks (ELS) due to starburst winds, powered by CSRs, ploughing into gas actively accreting onto the dark halo. The winds effectively carry energy from the dense, dusty environment of a starburst into lower density regions, where the escape probability for Ly-a photons is greater. ELS emission is expected to be considerably more clumpy (<...

  20. On the Evolution of the Ionizing Emissivity of Galaxies and Quasars Required by the Hydrogen Reionization

    CERN Document Server

    Miralda-Escudé, J

    2003-01-01

    The average rate of emission of ionizing radiation per unit volume (or emissivity) in the universe can be obtained from the ratio of the intensity of the ionizing background to the mean free path of ionizing photons. The intensity of the background is measured from the mean transmitted flux of the Lya forest, and the mean free path is measured from the abundance of Lyman limit systems, which has been observed so far up to z=4. This yields an emissivity that is not larger than 7 ionizing photons per Hubble time for each atom in the universe at z=4, which may reasonably arise from QSOs and Lyman break galaxies. In order for the reionization to end at z=6, and assuming that the clumping factor of ionized gas during the reionization epoch is close to unity, this ionizing emissivity needs to stay roughly constant from z=4 to z ~ 10, and cannot decline with redshift by more than a factor 1.5 over this redshift interval. If the clumping factor of the ionized gas were much larger than unity, then the emissivity would...

  1. HST-COS Observations of Hydrogen, Helium, Carbon and Nitrogen Emission from the SN 1987A Reverse Shock

    CERN Document Server

    France, Kevin; Penton, Steven V; Kirshner, Robert P; Challis, Peter; Laming, J Martin; Bouchet, Patrice; Chevalier, Roger; Fransson, Claes; Garnavich, Peter M; Heng, Kevin; Larsson, Josefin; Lawrence, Stephen; Lundqvist, Peter; Panagia, Nino; Pun, Chun S J; Smith, Nathan; Sollerman, Jesper; Sonneborn, George; Sugerman, Ben; Wheeler, J Craig

    2011-01-01

    We present the most sensitive ultraviolet observations of Supernova 1987A to date. Imaging spectroscopy from the Hubble Space Telescope-Cosmic Origins Spectrograph shows many narrow (dv \\sim 300 km/s) emission lines from the circumstellar ring, broad (dv \\sim 10 -- 20 x 10^3 km/s) emission lines from the reverse shock, and ultraviolet continuum emission. The high signal-to-noise (> 40 per resolution element) broad LyA emission is excited by soft X-ray and EUV heating of mostly neutral gas in the circumstellar ring and outer supernova debris. The ultraviolet continuum at \\lambda > 1350A can be explained by HI 2-photon emission from the same region. We confirm our earlier, tentative detection of NV \\lambda 1240 emission from the reverse shock and we present the first detections of broad HeII \\lambda1640, CIV \\lambda1550, and NIV] \\lambda1486 emission lines from the reverse shock. The helium abundance in the high-velocity material is He/H = 0.14 +/- 0.06. The NV/H-alpha line ratio requires partial ion-electron e...

  2. Comparison of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) in corticosteroid-naive patients with conduction system disease due to cardiac sarcoidosis

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Hiroshi; Birnie, David H.; Mc Ardle, Brian; Dick, Alexander; Klein, Ran; Renaud, Jennifer; DeKemp, Robert A.; Davies, Ross; Hessian, Renee; Liu, Peter; Nery, Pablo B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); Pena, Elena; Dennie, Carole [The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); Bernick, Jordan; Wells, George A. [University of Ottawa Heart Institute, Cardiovascular Research Methods Center, Ottawa, ON (Canada); Leung, Eugene [The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Yoshinaga, Keiichiro [Hokkaido University School of Medicine, Department of Molecular Imaging, Hokkaido (Japan); Tsujino, Ichizo; Sato, Takahiro; Nishimura, Masaharu [Hokkaido University School of Medicine, First Department of Medicine, Hokkaido (Japan); Manabe, Osamu; Tamaki, Nagara [Hokkaido University School of Medicine, Department of Nuclear Medicine, Hokkaido (Japan); Oyama-Manabe, Noriko [Hokkaido University Hospital, Diagnostic and Interventional Radiology, Hokkaido (Japan); Ruddy, Terrence D.; Beanlands, Rob S.B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Chow, Benjamin J.W. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada)

    2016-02-15

    Cardiac sarcoidosis (CS) is a cause of conduction system disease (CSD). {sup 18}F-Fluorodeoxyglucose-positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) are used for detection of CS. The relative diagnostic value of these has not been well studied. The aim was to compare these imaging modalities in this population. We recruited steroid-naive patients with newly diagnosed CSD due to CS. All CS patients underwent both imaging studies within 12 weeks of each other. Patients were classified into two groups: group A with chronic mild CSD (right bundle branch block and/or axis deviation), and group B with new-onset atrioventricular block (AVB, Mobitz type II or third-degree AVB). Thirty patients were included. Positive findings on both imaging studies were seen in 72 % of patients (13/18) in group A and in 58 % of patients (7/12) in group B. The remainder (28 %) of the patients in group A were positive only on CMR. Of the patients in group B, 8 % were positive only on CMR and 33 % were positive only on FDG PET. Patients in group A were more likely to be positive only on CMR, and patients in group B were more likely to be positive only on FDG PET (p = 0.02). Patients in group B positive only on FDG PET underwent CMR earlier relative to their symptomatology than patients positive only on CMR (median 7.0, IQR 1.5 - 34.3, vs. 72.0, IQR 25.0 - 79.5 days; p = 0.03). The number of positive FDG PET and CMR studies was different in patients with CSD depending on their clinical presentation. This study demonstrated that CMR can adequately detect cardiac involvement associated with chronic mild CSD. In patients presenting with new-onset AVB and a negative CMR study, FDG PET may be useful for detecting cardiac involvement due to CS. (orig.)

  3. SU-E-T-231: Measurements of Gold Nanoparticle-Mediated Proton Dose Enhancement Due to Particle-Induced X-Ray Emission and Activation Products Using Radiochromic Films and CdTe Detector

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J; Cho, S [Dept. of Radiation Physics, UT MD Anderson Cancer Center, Houston, TX (United States); Manohar, N [Dept. of Radiation Physics, UT MD Anderson Cancer Center, Houston, TX (United States); Medical Physics Program, Georgia Institute of Technology, Atlanta, GA (Georgia); Krishnan, S [Dept. of Radiation Oncology, UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-01

    Purpose: There have been several reports of enhanced cell-killing and tumor regression when tumor cells and mouse tumors were loaded with gold nanoparticles (GNPs) prior to proton irradiation. While particle-induced xray emission (PIXE), Auger electrons, secondary electrons, free radicals, and biological effects have been suggested as potential mechanisms responsible for the observed GNP-mediated dose enhancement/radiosensitization, there is a lack of quantitative analysis regarding the contribution from each mechanism. Here, we report our experimental effort to quantify some of these effects. Methods: 5-cm-long cylindrical plastic vials were filled with 1.8 mL of either water or water mixed with cylindrical GNPs at the same gold concentration (0.3 mg Au/g) as used in previous animal studies. A piece of EBT2 radiochromic film (30-µm active-layer sandwiched between 80/175-µm outer-layers) was inserted along the long axis of each vial and used to measure dose enhancement due to PIXE from GNPs. Vials were placed at center-of-modulation (COM) and 3-cm up-/down-stream from COM and irradiated with 5 different doses (2–10 Gy) using 10-cm-SOBP 160-MeV protons. After irradiation, films were cleaned and read to determine the delivered dose. A vial containing spherical GNPs (20 mg Au/g) was also irradiated, and gamma-rays from activation products were measured using a cadmium-telluride (CdTe) detector. Results: Film measurements showed no significant dose enhancement beyond the experimental uncertainty (∼2%). There was a detectable activation product from GNPs, but it appeared to contribute to dose enhancement minimally (<0.01%). Conclusion: Considering the composition of EBT2 film, it can be inferred that gold characteristic x-rays from PIXE and their secondary electrons make insignificant contribution to dose enhancement. The current investigation also suggests negligible dose enhancement due to activation products. Thus, previously-reported GNP-mediated proton dose

  4. 1965-2010年大兴安岭森林火灾碳排放的估算研究%Estimation of carbon emissions due to forest fire in Daxing'an Mountains from 1965 to 2010

    Institute of Scientific and Technical Information of China (English)

    胡海清; 魏书精; 孙龙

    2012-01-01

    火干扰是森林生态系统的重要干扰因子,是导致植被和土壤碳储量发生变化的重要原因.火干扰所排放的含碳气体对气候变化具有重要的影响.科学有效地对森林火灾所排放的碳进行计量,对了解区域和全球的碳平衡及碳循环具有重要的意义.根据大兴安岭森林资源调查数据和1965-2010年森林火灾统计资料,利用地理信息系统GIS (geographic information system)技术,通过野外火烧迹地调查与室内控制环境实验相结合的方法确定各种计量参数,从林分水平上,采用排放因子法,估算了大兴安岭1965-2010年46年间森林火灾所排放的碳和含碳气体量.结果表明:大兴安岭46年间森林火灾排放的碳为2.93×107 t,年平均排放量为6.38×105 t,约占全国年均森林火灾碳排放量的5.64%;含碳气体CO2、CO、CH4和非甲烷烃(NMHC)的排放量分别为1.02×108、9.41×106、5.41×105和2.11×105t,含碳气体CO2、CO、CH4和NMHC的年均排放量分别为2.22×106、2.05×105、1.18×104和4.59×103t,分别占全国年均森林火灾各含碳气体排放量的5.46%、7.56%、10.54%和4.06%;针阔混交林燃烧效率较低,虽然火烧面积占总过火面积的21.23%,但排放的碳只占总排放量的7.81%,为此提出了相应的林火管理策略.%Aims Forest fire is a major disturbance factor for forest ecosystems and an important pathway of decreasing vegetation- and soil-carbon storage. Scientifically and effectively measuring carbonaceous gases emission from forest fire is important in understanding the significance of forest fire in carbon balance and climate change. However, carbon emissions from forest fire remain unclear. Our objective was to estimate carbon emissions from forest fires from 1965 to 2010 in Daxing'an Mountains of Heilongjiang Province, China. Methods We used a geographic information system (GIS) based modeling approach to generate emission estimates using a two

  5. Emission Trading

    OpenAIRE

    2009-01-01

    The work concerns Emission Trading Scheme from perspektive of taxes and accounting. I should show problems with emission trading. The work concerns practical example of trading with emission allowance.

  6. Estimates of carbon emissions in Heihe city due to forest fires%黑河市森林火灾碳排放的计量估算研究

    Institute of Scientific and Technical Information of China (English)

    魏书精; 罗碧珍; 魏书威; 正敏; 孙龙; 胡海清

    2014-01-01

    We estimated the emission of carbon and carbonaceous gases including carbon dioxide ( CO2 ) , carbon mon-oxide ( CO) , methane ( CH4 ) , and nonmethane hydrocarbons ( NMHC) from forest fires from 1971 to 2011 in Heihe city of Heilongjiang province, China. We used a geographic information system ( GIS)-based modeling approach to esti-male emissions through a two-step procedure. In step one, we calculated total carbon released from forest fires in Heihe for selected years between 1971 and 2011 by merging and analyzing several measurement parameters. In step two, we calculated amounts of four carbonaceous gases released during the burn, CO2 , CO, CH4 , and NMHC, using several dif-ferent experimentally derived emission factors. The origin of each of the inputs used in our models was based on a combi-nation of analysis of forest fire inventory, forest resources inventory, field research, and laboratory experiments. Direct total carbon emissions from forest fires in Heihe during 1971 to 2011 was about 4�00×107 t, and mean annual carbon e-missions was about 9�76×105 t per year, accounting for 8�63% of the direct total carbon emissions from forest fires in China. Amount of carbon emission resulted from the atmospheric emissions of four trace gases was as follows:the emis-sions of CO2, CO, CH4 and NMHC from forest fires were 1.24×108,6.51×106,4�30×105, and 3�47×105 t, respective-ly, and mean annual emissions of CO2, CO, CH4, and NMHC from forest fires were 3.01×106,1.59×105,1.05×104, and 8.46×103, respectively, accounting for 7.42%, 5.86%, 9.37% and 7.49% of amounts of four carbonaceous gases released from forest fires in China, respectively. We promoted the corresponding forest fire management strategy. At the same time, the studies showed that the area mean annual carbon emissions had an important impact on the re-gional carbon balance. We suggested that the management strategy of forest fire should strengthen the sustainable man- agement of forest

  7. Measurements of K Shell Emission of Highly Charged Ions with the XRS at EBIT

    Science.gov (United States)

    Porter, F. Scott; Beiersdorfer, P.; Boyce, K.; Brown, G. V.; Chen, H.; Kahn, S.; Kelley, R.; Kilbourne, C. A.

    2004-01-01

    The XRS/EBIT is a 32 channel microcalorimeter spectrometer operating at the electron beam ion trap (EBIT) facility at Lawrence Livermore National Laboratory. The system contains a flight candidate detector array from the XRS instrument for the Astro-E2 mission. The detector array in the XRS/EBIT is functionally identical to the flight array integrated into the XRS instrument and benefits from the enormous amount of calibration data from the XRS program. Since the XRSEBIT was upgraded with the new detector array in October 2003, the system has been used for a number of experiments including a survey of the K shell emission from He-like and H-like O, Ne, Ar, Fe, Ni and Kr as well as for L shell emission to measure the 3C/3D line ratio in Ni. Here we present some basic operational parameters of the instrument as well as direct excitation and simulated maxwellian spectra of He-like and E-like Fe. We show that the XRS instrument can resolve the Lyal and Lya2 lines from each other as well as from the dielectronic recombination satellites in thermal H-like Fe. We also show exactly how well the XRS instrument on Astro-E2 will resolve the thermal He-like triplet in collisionally excited Fe. This work was funded under NASA's Research Opportunities in Space Science program.

  8. Experimental study of acoustic emission of granite due to thermal cracking under high temperature and isostatic stress%高温均匀压力花岗岩热破裂声发射特性实验研究

    Institute of Scientific and Technical Information of China (English)

    武晋文; 赵阳升; 万志军; 冯子军; 董付科; 李义

    2012-01-01

    In order to obtain the rules of thermal cracking on granite, the evolution of the acoustic emission of granite sample( φ200 mm×400 mm)within the temperature range from the room temperature to 500 ℃ under isostatic stress and the thermal cracking characteristics of the rock as manifested by the acoustic emissions in each stage were ana- lyzed and discussed based on experiments. It is shown in this research that 330 ℃ is the demarcation point of acoustic emission and hot rock changed. Thermal cracking is elastic rupture when temperature is lower than 330 ℃and it ap- pears a local plastic deformation and failure beyond 330 ℃ ;When the granite sample is heated to 330℃, a great num- ber of acoustic emission of lower energy rate occurres from local plastic failure. In concentrated area of acoustic emis- sion, most acoustic emission is in low energy rate and a little is in high energy rate, and the whole cumulative energy is lower than the cumulative energy at 330 ℃and below ; When the counts rate of acoustic emission abruptly changes, the micro-fracture zone of granite begins to form and the granite experiences two significant improvements of the thermal crack network respectively from the temperatures of 110℃ and 420 ℃.%为研究花岗岩体热破裂规律,通过实验研究了均匀压力(25 MPa)下大试件(200 mm×400 mm)花岗岩在常温~500℃范围的声发射变化规律及特性,探讨了各个阶段声发射信号反映的岩石破裂特性。研究表明:①330℃为花岗岩破裂声发射和热破裂性质转变的分界点,低于330℃,热破裂为弹性破裂,330℃以后,花岗岩出现局部塑性变形和破坏;②330℃以后,局部塑性破坏造成大量低能量释放率的声发射产生,声发射密集区由小部分能量率很大的声发射和数量很多、低能量释放率的声发射组成,声发射密集区整体上累积释放能量较低;③声发射振铃率发生突变可以作为花岗岩内部

  9. Global Seabird Ammonia Emissions

    Science.gov (United States)

    Riddick, S. N.; Blackall, T. D.; Dragosits, U.; Daunt, F. H.; Braban, C. F.; Tang, Y. S.; Trathan, P.; Wanless, S.; Sutton, M. A.

    2010-12-01

    Seabird colonies represent a major source of atmospheric ammonia (NH3) in remote coastal and marine systems in temperate, tropical and polar regions. Previous studies have shown that NH3 emissions from Scottish seabird colonies were substantial - of similar magnitude to the most intensive agricultural point source emissions. The UK data were used to model global seabird NH3 emissions and suggested that penguins are a major source of emissions on and around the Antarctic continent. The largest seabird colonies are in the order of millions of seabirds. Due to the isolation of these colonies from anthropogenic nitrogen sources, they may play a major role in the nitrogen cycle within these ecosystems. A global seabird database was constructed and used in conjunction with a species-specific seabird bioenergetics model to map the locations of NH3 emissions from seabird colonies. The accuracy of the modelled emissions was validated with field data of NH3 emissions measured at key seabird colonies in different climatic regions of the world: temperate (Isle of May, Scotland), tropical (Ascension Island) and polar (Signy Island, South Georgia). The field data indicated good agreement between modelled and measured NH3 emissions. The measured NH3 emissions also showed the variability of emission with climate. Climate dependence of seabird NH3 emissions may have further implications under a changing global climate. Seabird colonies represent NH3 emission ‘hotspots’, often far from anthropogenic sources, and are likely to be the major source of nitrogen input to these remote coastal ecosystems. The direct manuring by seabirds at colony locations may strongly influence species richness and biodiversity. The subsequent volatilisation and deposition of NH3 increases the spatial extent of seabird influence on nitrogen cycling in their local ecosystem. As many seabird populations are fluctuating due to changing food supply, climate change or anthropogenic pressures, these factors

  10. Strong Optical and UV Intermediate-Width Emission Lines in the Quasar SDSS J232444.80-094600.3: Dust-Free and Intermediate-Density Gas at the Skin of Dusty Torus ?

    CERN Document Server

    Li, Zhenzhen; Hao, Lei; Wang, Shufen; Ji, Tuo; Liu, Bo

    2016-01-01

    Emission lines from the broad emission line region (BELR) and the narrow emission line region (NELR) of active galactic nuclei (AGNs) are extensively studied. However, between these two regions emission lines are rarely detected. We present a detailed analysis of a quasar SDSS J232444.80-094600.3 (SDSS J2324$-$0946), which is remarkable for its strong intermediate-width emission lines (IELs) with FWHM $\\approx$ 1800 \\kmps. The IEL component is presented in different emission lines, including the permitted lines \\lya\\ $\\lambda$1216, \\civ\\ $\\lambda$1549, semiforbidden line \\ciii\\ $\\lambda$1909, and forbidden lines \\oiii\\ $\\lambda\\lambda$4959, 5007. With the aid of photo-ionization models, we found that the IELs are produced by gas with a hydrogen density of $n_{\\rm H} \\sim 10^{6.2}-10^{6.3}~\\rm cm^{-3}$, a distance to the central ionizing source of $R \\sim 35-50$ pc, a covering factor of CF $\\sim$ 6\\%, and a dust-to-gas ratio of $\\leq 4\\%$ times of SMC. We suggest that the strong IELs of this quasar are produce...

  11. Neutron stimulated emission computed tomography applied to the assessment of calcium deposition due to the presence of microcalcifications associated with breast cancer; Tomografia computadorizada de emissao estimulada por neutrons aplicada para avaliar a deposicao de calcio devido a presenca de microcalcificacoes associadas ao cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Rodrigo S.S.; Yoriyaz, Helio [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, (SP) (Brazil)

    2011-07-01

    In this paper we presented an application of the Neutron Stimulated Emission Computed Tomography (NSECT), which uses a thin beam of fast neutrons to stimulate stable nuclei in a sample, emitting characteristic gamma radiation. The photon energy is unique and it is used to identify the emitting nuclei. This technique was applied for evaluating the calcium isotopic composition changing due to the development of breast microcalcifications. A particular situation was simulated in which clustered microcalcifications were modeled with diameters less than 1.40 mm. In this case, neutron beam breast spectroscopy was successful in detecting the counting changes in the photon emission spectra for energies, which are characteristics of 4{sup 0C}a isotope in a low deposited dose rate. (author)

  12. Collection of trace evidence of explosive residues from the skin in a death due to a disguised letter bomb. The synergy between confocal laser scanning microscope and inductively coupled plasma atomic emission spectrometer analyses.

    Science.gov (United States)

    Turillazzi, Emanuela; Monaci, Fabrizio; Neri, Margherita; Pomara, Cristoforo; Riezzo, Irene; Baroni, Davide; Fineschi, Vittorio

    2010-04-15

    In most deaths caused by explosive, the victim's body becomes a depot for fragments of explosive materials, so contributing to the collection of trace evidence which may provide clues about the specific type of device used with explosion. Improvised explosive devices are used which contain "homemade" explosives rather than high explosives because of the relative ease with which such components can be procured. Many methods such as chromatography-mass spectrometry, scanning electron microscopy, stereomicroscopy, capillary electrophoresis are available for use in the identification of explosive residues on objects and bomb fragments. Identification and reconstruction of the distribution of explosive residues on the decedent's body may give additional hints in assessing the position of the victim in relation to the device. Traditionally these residues are retrieved by swabbing the body and clothing during the early phase, at autopsy. Gas chromatography-mass spectrometry and other analytical methods may be used to analyze the material swabbed from the victim body. The histological examination of explosive residues on skin samples collected during the autopsy may reveal significant details. The information about type, quantity and particularly about anatomical distribution of explosive residues obtained utilizing confocal laser scanning microscope (CLSM) together with inductively coupled plasma atomic emission spectrometer (ICP-AES), may provide very significant evidence in the clarification and reconstruction of the explosive-related events.

  13. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

    Emissions trading is a market-based instrument to achieve environmental targets in a cost-effective way by allowing legal entities to buy and sell emission rights. The current international dissemination and intended linking of emissions trading schemes underlines the growing relevance of this

  14. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

    Emissions trading is a market-based instrument to achieve environmental targets in a cost-effective way by allowing legal entities to buy and sell emission rights. The current international dissemination and intended linking of emissions trading schemes underlines the growing relevance of this instr

  15. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  16. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  17. Emission of greenhouse gases in the atmosphere of the Manaus city due to burning of fossil fuels; Emissao de gases poluentes na atmosfera urbana da cidade de Manaus devida a queima de combustiveis fosseis

    Energy Technology Data Exchange (ETDEWEB)

    Valois, I.M. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Fac. de Tecnologia], E-mail: ivalois@ufam.edu.br; Cartaxo, E.F. [Universidade Federal do Amazonas (NIEMA/UFAM), Manaus, AM (Brazil). Fac. de Tecnologia. Nucleo de Energia, Meio Ambiente e Agua], E-mail: ecartaxo@ufam.edu.br; Chaar, Jamal da Silva [Universidade Federal do Amazonas (ICE/UFAM), Manaus, AM (Brazil). Inst. de Ciencias Exatas

    2009-07-01

    This paper intends to think over the impacts of pollutants gases in the atmosphere of the city of Manaus, caused by the thermal, the main electricity source in the State of Amazonas. The focus of the study is the urban atmosphere where physical and chemical phenomenon accelerate the effects of increased concentration of some components and secondary pollutants, which are produced due to human activities. It is based on two studies: monitoring the exhaust gas applied at a factory in the district of Aparecida, located in the urban area, and monitoring conducted by the energy operating company, about the influence of exhaust gas around the district of Mauazinho, also in urban area. It is a preliminary research that seeks to demonstrate the inconsistency of some studies and the need to make progress in search for more efficient methods and techniques. This is an important step toward a policy of environmental management that will complement future studies about air pollution in the city. (author)

  18. Emission inventory; Inventaire des emissions

    Energy Technology Data Exchange (ETDEWEB)

    Fontelle, J.P. [CITEPA, Centre Interprofessionnel Technique d`Etudes de la Pollution Atmospherique, 75 - Paris (France)

    1997-12-31

    Statistics on air pollutant (sulfur dioxide, nitrogen oxides and ammonium) emissions, acid equivalent emissions and their evolution since 1990 in the various countries of Europe and the USA, are presented. Emission data from the industrial, agricultural, transportation and power sectors are given, and comparisons are carried out between countries based on Gnp and population, pollution import/export fluxes and compliance to the previous emission reduction objectives

  19. Can a Resonant Quantum-Well State be Used as the initial and/or Final State of a Golden-Rule Calculation for a Transition Rate due to Photon or Phonon Emission or Absorption?

    Science.gov (United States)

    Hu, Chia-Ren

    1997-03-01

    According to conventional wisdom, the answer would be `no'. A resonant quantum-well state is an eigen-state with a complex eigen-energy (imaginary part negative), due to tunneling through a potential barrier into a reservoir. Such a state is obtained by demanding that only an `out-going' wave (i.e., away from the tunneling barrier) exists in the reservoir. Its wave function cannot be normalized. Therefore, it cannot be used in the way stated in the title. We have investigated a way to change the answer to `yes', so far with partial success. (I.e., `yes', but with some undesirable features.) An idea to improve it is currently being explored, and will be reported at the meeting. Our main trick is to introduce a suitable optical potential in the reservoir, in order to make the resonant state normalizable, and yet with a complex energy very close to the original value. The Fermi golden rule is then generalized, in order to accommodate a non-hermitian Hamiltonian. Other non-resonant reservoir states should make negligible contributions to the transition rate, if this trick is to work.

  20. Lyman-alpha Cooling Emission from Galaxy Formation

    CERN Document Server

    Faucher-Giguere, C -A; Dijkstra, M; Hernquist, L; Zaldarriaga, M

    2010-01-01

    Recent studies have shown that galaxies accrete most of their baryons via the cold mode, from streams with temperatures T~10^4-10^5 K. At these temperatures, the streams should radiate primarily in Lya and have therefore been proposed as a model to power the Lya blobs and other high-redshift Lya sources. We introduce a new Lya radiative transfer code, aRT, and apply it to cosmological hydrodynamical simulations. We address physical and numerical issues that are critical to making accurate predictions for the cooling luminosity, but that have been mostly neglected or treated simplistically so far. We highlight the importance of self-shielding and of properly treating sub-resolution models in simulations. Most existing simulations do not self-consistently incorporate these effects, which can lead to order-of-magnitude errors in the predicted cooling luminosity. Using a combination of post-processing ionizing radiative transfer and re-simulation techniques, we develop an approximation to the consistent evolution...

  1. Energy Related Carbon Dioxide Emission and Carbon Reduction Benefit Due to Implementation of Energy Saving and Emission Reduction in Shanghai%上海市能源CO2排放及节能减排的减碳效果分析

    Institute of Scientific and Technical Information of China (English)

    李莉

    2011-01-01

    以2006年为基准,采用IPCC清单指南推荐的方法测算了上海市能源活动产生的CO2排放清单.并采用情景分析方法,预测了高碳情景和低碳情景下七海市能源需求及相应的二氧化碳排放趋势,探讨了节能减排等低碳政策所产生的碳削减的潜力.研究表明,2006年上海市能源活动所排放的CO2总量为1.80亿t,其中,能源加工转换产生的CO2排放量为7550万t,占排放总量的42%;工业次之,占30%;交通运输的排放比例为18%.煤炭和石油的消费是导致CO2排放的主要原因,2006年煤炭所带来的CO2排放量为1.11亿t,油品所产生的CO2排放量为0.64亿t,分别占到能源活动CO2排放总量的61.5%和35.5%.2006年上海市人均CO2排放量为10.02t/人,是世界平均水平的2.5倍,是中国平均水平的2.7倍.研究表明,在低碳政策下,上海能源需求将有所控制,到2020年全市能源需求总量为1.6亿t标煤,比高碳情景节约1.2亿t标煤.节能减排政策还将使得全市能源活动CO2排放比高碳情景显著下降,到2020年全市CO2排放量为3.26亿t,比高碳情景减少3.1亿t,低碳政策所产生的碳减排效益十分明显.%Taking 2006 as the base year, energy related CO2 emission inventory was built following IPCC guidelines.Based on scenario analysis, energy demand and CO2 emissions were predicted under high carbon and low carbon scenarios. Carbon mitigation potential under low carbon policies such as energy saving and emission reducing was analyzed. Results showed that total energy related CO2 emission in Shanghai in 2006 was 180 million tons, among which CO2 emissions from energy production and transformation were 75.5 million tons, taking a share of 42%, industry 30% and transportation 18%. Coal and oil consumption are major reasons causing huge CO2 emissions. In 2006, coal, oil and natural gas combustion contributed 111, 64 and 4 million tons of CO2 emissions, taking shares of 61.5%, 35.5% and 2.3

  2. Ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2012-01-01

    measures might be cheaper in the Netherlands and Denmark than in the UK and the USA due to technology advances and stricter regulations in the past. The new Danish application procedure, when increasing the animal production, has tried to make the acceptance procedure quicker and dynamic ensuring that new......The NEC (National Emission Ceiling) directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries...... technology is adopted quicker and that the farm has the right location. It is concluded that the new application process so far has not lived up to the high expectations at the outset. Despite this, the paper concludes that Denmark is likely to reduce emission by 50% from 1990 to 2020 and reach the likely...

  3. Irreversible Climate Change Due to Carbon Dioxide Emissions

    National Research Council Canada - National Science Library

    Susan Solomon; Gian-Kasper Plattner; Reto Knutti; Pierre Friedlingstein

    2009-01-01

    ... do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv...

  4. Directional Lya Equivalent Boosting I: Spherically Symmetric Distributions of Clumps

    CERN Document Server

    Gronke, Max

    2014-01-01

    We quantify the directional dependence of the escape fraction of Lyman-$\\alpha$ (Ly$\\alpha$) and non-ionising UV-continuum photons from a multiphase medium, and investigate whether there exist directional enhancements in the Ly$\\alpha$ equivalent width (EW). Our multiphase medium consists of spherically symmetric distributions of cold, dusty clumps embedded within a hot dust-free medium. We focus on three models from the analysis presented by Laursen et al. (2013). We find that for a Ly$\\alpha$ and UV-continuum point source, it is possible to find an EW boost $b(\\theta,\\phi) > 5 \\bar{b}$ in a few per cent of sight lines, where $\\bar{b}$ denotes the boost averaged over all photons. For spatially extended sources this directional dependence vanishes quickly when the size of the UV emitting region exceeds the mean distance between cold dusty clumps. Our analysis suggests that directional EW boosting can occur, and that this is mostly driven by reduced escape fractions of UV photons (which gives rise to UV-contin...

  5. Discovery of a Giant Lya Emitter Near the Reionization Epoch

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Masami; Ono, Yoshiaki; Egami, Eiichi; Saito, Tomoki; Oguri, Masamune; McCarthy, Patrick J.; Farrah, Duncan; Kashikawa, Nobunari; Momcheva, Ivelina; Shimasaku, Kazuhiro; Nakanishi, Kouichiro; Furusawa, Hisanori; Akiyama, Masayuki; Dunlop, James S.; Mortier, Angela M.J.; Okamura, Sadanori; Hayashi, Masao; Cirasuolo, Michele; Dressler, Alan; Iye, Masanori; Jarvis, Matt.J.

    2008-08-01

    We report the discovery of a giant Ly{alpha} emitter (LAE) with a Spitzer/IRAC counterpart near the reionization epoch at z = 6.595. The giant LAE is found from the extensive 1 deg{sup 2} Subaru narrow-band survey for z = 6.6 LAEs in the Subaru/XMM-Newton Deep Survey (SXDS) field, and subsequently identified by deep spectroscopy of Keck/DEIMOS and Magellan/IMACS. Among our 207 LAE candidates, this LAE is not only the brightest narrow-band object with L(Ly{alpha}) = 3.9 {+-} 0.2 x 10{sup 43} erg s{sup -1} in our survey volume of 10{sup 6} Mpc{sup 3}, but also a spatially extended Ly{alpha} nebula with the largest isophotal area whose major axis is at least {approx_equal} 3-inches. This object is more likely to be a large Ly{alpha} nebula with a size of {approx}> 17-kpc than to be a strongly-lensed galaxy by a foreground object. Our Keck spectrum with medium-high spectral and spatial resolutions suggests that the velocity width is v{sub FWHM} = 251 {+-} 21 km s{sup -1}, and that the line-center velocity changes by {approx_equal} 60 km s{sup -1} in a 10-kpc range. The stellar mass and star-formation rate are estimated to be 0.9-5.0 x 10{sup 10}M{sub {circle_dot}} and > 34 M{sub {circle_dot}}yr{sup -1}, respectively, from the combination of deep optical to infrared images of Subaru, UKIDSS-Ultra Deep Survey, and Spitzer/IRAC. Although the nature of this object is not yet clearly understood, this could be an important object for studying cooling clouds accreting onto a massive halo, or forming-massive galaxies with significant outflows contributing to cosmic reionization and metal enrichment of inter-galactic medium.

  6. lya theory of hypercubes (revision of preprint 925)

    NARCIS (Netherlands)

    Lemmens, P.W.H.

    1996-01-01

    The cycle index polynomial is described for the action of the full isometry group of the n-dimensional hypercube on its q-dimensional cells. This group action is interpreted as C n 2 Sn acting on the set of unit basis vectors in R n and their opposites. A kind of generating function that yields all

  7. High redshift Lya emitters: clues on the Milky Way infancy

    CERN Document Server

    Salvadori, S; Ferrara, A

    2010-01-01

    With the aim of determining if Milky Way (MW) progenitors could be identified as high redshift Lyman Alpha Emitters (LAEs) we have derived the intrinsic properties of z ~ 5.7 MW progenitors, which are then used to compute their observed Lyman-alpha luminosity, L_alpha, and equivalent width, EW. MW progenitors visible as LAEs are selected according to the canonical observational criterion, L_alpha > 10^42 erg/s and EW > 20 A. Progenitors of MW-like galaxies have L_alpha = 10^(39-43.25) erg/s, making some of them visible as LAEs. In any single MW merger tree realization, typically only 1 (out of ~ 50) progenitor meets the LAE selection criterion, but the probability to have at least one LAE is very high, P = 68%. The identified LAE stars have ages, t_* ~ 150-400 Myr at z ~ 5.7 with the exception of five small progenitors with t_* 10% of the halo very metal-poor stars [Fe/H] < -2, thus establishing a potentially fruitful link between high-z galaxies and the Local Universe.

  8. Deep VLT spectroscopy of the z=2.49 Radio Galaxy MRC 2104-242 Evidence for a metallicity gradient in its extended emission line region

    CERN Document Server

    Overzier, R; Kurk, J D; De Breuck, C

    2001-01-01

    We present spectroscopic observations of the rest-frame UV line emission around radio galaxy MRC 2104-242 at z=2.49, obtained with FORS1 on VLT Antu. The morphology of the halo is dominated by two spatially resolved regions. Lya is extended by >12 arcsec along the radio axis, CIV and HeII are extended by ~8 arcsec. The overall spectrum is typical for that of high redshift radio galaxies. The most striking spatial variation is that NV is present in the spectrum of the region associated with the center of the galaxy hosting the radio source, the northern region, while absent in the southern region. Assuming that the gas is photoionized by a hidden quasar, the difference in NV emission can be explained by a metallicity gradient within the halo. This is consistent with a scenario in which the gas is associated with a massive cooling flow or originates from the debris of the merging of two or more galaxies.

  9. Diplopia due to Dacryops

    OpenAIRE

    Rahmi Duman; Reşat Duman; Mehmet Balcı

    2013-01-01

    Dacryops is a lacrimal ductal cyst. It is known that it can cause globe displacement, motility restriction, and proptosis because of the mass effect. Diplopia due to dacryops has not been reported previously. Here, we present a 57-year-old man with binocular horizontal diplopia that occurred during left direction gaze due to dacryops.

  10. Diplopia due to Dacryops

    Directory of Open Access Journals (Sweden)

    Rahmi Duman

    2013-01-01

    Full Text Available Dacryops is a lacrimal ductal cyst. It is known that it can cause globe displacement, motility restriction, and proptosis because of the mass effect. Diplopia due to dacryops has not been reported previously. Here, we present a 57-year-old man with binocular horizontal diplopia that occurred during left direction gaze due to dacryops.

  11. Annual Danish Emissions Inventory Report to UNECE

    DEFF Research Database (Denmark)

    Illerup, J. B.; Lyck, E.; Nielsen, M.

    This report is a documentation report on the emission inventories for Denmark as reported to the UNECE Secretariat under the Convention on Long-range Transboundary Air Pollution due by 15 February 2003. The report contains information on Denmark's emission inventories regarding emissions of (1) NOx...

  12. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2007 was 10......% lower than in 1990. However fluctuations in the emission level are large as a result of electricity import/export. The emission of CH4 has increased due to increased use of lean-burn gas engines in combined heating and power (CHP) plants. However the emission has decreased in recent years due...... to structural changes in the Danish electricity market. The N2O emission was higher in 2007 than in 1990 but the fluctuations in the time-series are significant. A considerable decrease of the SO2, NOx and heavy metal emissions is mainly a result of decreased emissions from large power plants and waste...

  13. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, PCDD/F, HCB and PAH. The CO2 emission in 2011...... of decreased emissions from large power plants and waste incineration plants. The combustion of wood in residential plants has increased considerably until 2007 resulting in increased emission of PAH and particulate matter. The emission of NMVOC has increased since 1990 as a result of both the increased...... was 30 % lower than in 1990. However, fluctuations in the emission level are large as a result of electricity import/export. The emission of CH4 has increased due to increased use of lean-burn gas engines in combined heating and power (CHP) plants. In recent years, the emission has declined. This is due...

  14. Annual Danish Emissions Inventory Report to UNECE

    DEFF Research Database (Denmark)

    Illerup, J. B.; Nielsen, M.; Winther, M.;

    This report is a documentation report on the emission inventories for Denmark as reported to the UNECE Secretariat under the Convention on Long Range Transboundary Air Pollution due by 15 February 2004. The report contains information on Denmark's emission inventories regarding emissions of (1) SOX......(k)fluoranthene and indeno(1,2,3-cd)pyrene for the years 1990-2002. Further, the report contains information on background data for emissions inventory...

  15. Annual Danish Emissions Inventory Report to UNECE

    DEFF Research Database (Denmark)

    Illerup, J. B.; Nielsen, M.; Winther, M.

    This report is a documentation report on the emission inventories for Denmark as reported to the UNECE Secretariat under the Convention on Long Range Transboundary Air Pollution due by 15 February 2004. The report contains information on Denmark's emission inventories regarding emissions of (1) SOX......(k)fluoranthene and indeno(1,2,3-cd)pyrene for the years 1990-2002. Further, the report contains information on background data for emissions inventory...

  16. Due process traditionalism.

    Science.gov (United States)

    Sunstein, Cass R

    2008-06-01

    In important cases, the Supreme Court has limited the scope of "substantive due process" by reference to tradition, but it has yet to explain why it has done so. Due process traditionalism might be defended in several distinctive ways. The most ambitious defense draws on a set of ideas associated with Edmund Burke and Friedrich Hayek, who suggested that traditions have special credentials by virtue of their acceptance by many minds. But this defense runs into three problems. Those who have participated in a tradition may not have accepted any relevant proposition; they might suffer from a systematic bias; and they might have joined a cascade. An alternative defense sees due process traditionalism as a second-best substitute for two preferable alternatives: a purely procedural approach to the Due Process Clause, and an approach that gives legislatures the benefit of every reasonable doubt. But it is not clear that in these domains, the first-best approaches are especially attractive; and even if they are, the second-best may be an unacceptably crude substitute. The most plausible defense of due process traditionalism operates on rule-consequentialist grounds, with the suggestion that even if traditions are not great, they are often good, and judges do best if they defer to traditions rather than attempting to specify the content of "liberty" on their own. But the rule-consequentialist defense depends on controversial and probably false assumptions about the likely goodness of traditions and the institutional incapacities of judges.

  17. Onycholysis due to trauma

    Directory of Open Access Journals (Sweden)

    Patricia Chang

    2014-04-01

    Full Text Available Female patient, 35 years old who came to the private office due to discoloration of her left thumbnail and little pain since 1 month ago. Clinical examination shows nail disease on her left thumbnail with onycholysis and dyschromia, dermatoscopy showed white-yellowish discoloration (Fig. 1A, B. The rest of the clinical examination was normal. Patient use to using acrylic nails since 2 years ago and denied some trauma at the nail. The diagnosis of onycholysis due to trauma was done and recommended her not to use acrylic nail, maintain the nail short and avoid wetness.

  18. Technical Due Diligence

    DEFF Research Database (Denmark)

    Jensen, Per Anker; Varano, Mattia

    2011-01-01

    Technical Due Diligence (TDD) as an evaluation of the performance of constructed facilities has become an important new field of practice for consultants. Before the financial crisis started in autumn 2008 it represented the fastest growing activity in some consulting companies. TDD is mostly car...

  19. Emission of formaldehyde from furniture

    DEFF Research Database (Denmark)

    Andersen, Helle Vibeke; Klinke, Helene B.; Funch, Lis Winther;

    2014-01-01

    The emission of formaldehyde from a variety of furniture was measured in climate chambers. Most tests show low emission of formaldehyde; however, there are a few exceptions. One product emitted significant amounts of formaldehyde, but according to the Danish Indoor Climate Labelling Criteria...... for furniture the impact on the formaldehyde concentration was low due to a small surface area in the standard room. One product led to a high concentration of formaldehyde in the standard room since both emission and material load were high. Even with a moderate area-specific emission rate of formaldehyde......, furniture with high material load in the standard room, such as bookcases, can have a significant impact on the indoor air. The results showed that furniture on the Danish market may have an emission of formaldehyde resulting in indoor concentrations above the WHO recommended limit of 0.1 mg m-3. Therefore...

  20. The long wavelength emission of interstellar PAHs: characterizing the spinning dust emission

    CERN Document Server

    Ysard, Nathalie

    2009-01-01

    The emission of cold dust grains at long wavelengths will soon be observed by the Planck and Herschel satellites and provide new constraints on the nature of interstellar dust. The microwave anomalous emission, proposed to be due to spinning PAHs, should help to better define these species. Moreover, understanding the fluctuations of the anomalous emission over the sky is crucial for CMB studies. We focus on the long wavelength emission of interstellar PAHs in their rovibrational and rotational transitions. The PAH emission spectrum from the IR to the microwave range is presented and compared to anomalous emission observations. To model their long wavelength emission, we treat PAHs as isolated systems and follow consistently their IR and rotational emissions. We consider several interstellar phases and discuss how the anomalous emission may constrain their size distribution. Our model of PAH emission accounts for the mid-IR spectra of the diffuse interstellar medium and of the Orion Bar. For lambda<3mm the...

  1. Danish emission inventories for road transport and other mobile sources

    DEFF Research Database (Denmark)

    Winther, Morten

    for road transport increased by 30 %, and CH4 emissions have decreased by 74 %. A N2O emission increase of 29 % is related to the relatively high emissions from older gasoline catalyst cars. The 1985-2010 emission decrease for NOX, NMVOC, CO and particulates (exhaust only: Size is below PM2.5) -52, -84......This report explains the parts of the Danish emission inventories related to road transport and other mobile sources. Emission results are shown for CO2, CH4, N2O, SO2, NOX, NMVOC, CO, particulate matter (PM), heavy metals, dioxins and PAH. From 1990-2010 the fuel consumption and CO2 emissions......, -81, and -65 %, respectively, due to the introduction of vehicles complying with gradually stricter emission standards. For SO2 the emission drop 99 % (due to reduced sulphur content in the diesel fuel), whereas the NH3 emissions increased by 2232 % (due to the introduction of catalyst cars...

  2. Danish emission inventories for road transport and other mobile sources

    DEFF Research Database (Denmark)

    Winther, Morten

    have increased by 36 %, and CH4 emissions have decreased by 51 %. A N2O emission increase of 29 % is related to the relatively high emissions from older gasoline catalyst cars. The 1985-2006 emission decreases for PM (exhaust only), CO, NOX and NMVOC are 30, 69, 28 and 71 % respectively, due......This report explains the parts of the Danish inventories related to road transport and other mobile sources. Emission results are shown for CO2, CH4, N2O, SO2, NOX, NMVOC, CO, particulate matter (PM), heavy metals, dioxins and PAH. From 1990-2006 the fuel use and CO2 emissions for road transport...... to the introduction of vehicles complying with gradually stricter emission standards. For SO2 the emission drop is 99% (due to reduced sulphur content in the diesel fuel), whereas the NH3 emissions increase by 3065% (due to the introduction of catalyst cars). For other mobile sources the calculated emission changes...

  3. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2008...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... was 16 % lower than in 1990. However, fluctuations in the emission level are large as a result of electricity import/export. The emission of CH4 has increased due to increased use of lean-burn gas engines in combined heating and power (CHP) plants. However, the emission has decreased in recent years due...

  4. Generalized emissivity inverse problem.

    Science.gov (United States)

    Ming, DengMing; Wen, Tao; Dai, XianXi; Dai, JiXin; Evenson, William E

    2002-04-01

    Inverse problems have recently drawn considerable attention from the physics community due to of potential widespread applications [K. Chadan and P. C. Sabatier, Inverse Problems in Quantum Scattering Theory, 2nd ed. (Springer Verlag, Berlin, 1989)]. An inverse emissivity problem that determines the emissivity g(nu) from measurements of only the total radiated power J(T) has recently been studied [Tao Wen, DengMing Ming, Xianxi Dai, Jixin Dai, and William E. Evenson, Phys. Rev. E 63, 045601(R) (2001)]. In this paper, a new type of generalized emissivity and transmissivity inverse (GETI) problem is proposed. The present problem differs from our previous work on inverse problems by allowing the unknown (emissivity) function g(nu) to be temperature dependent as well as frequency dependent. Based on published experimental information, we have developed an exact solution formula for this GETI problem. A universal function set suggested for numerical calculation is shown to be robust, making this inversion method practical and convenient for realistic calculations.

  5. Extended Lyman-alpha emission from cold accretion streams

    CERN Document Server

    Rosdahl, J

    2011-01-01

    {Abridged} We investigate the observability of cold accretion streams at redshift 3 via Lyman-alpha radiation and the feasibility of cold accretion as the main driver behind giant Lya blobs (LABs). We run cosmological zoom simulations focusing on 3 halos spanning two orders of magnitude in mass, from 10^11 to 10^13 solar masses. We use a version of the AMR code Ramses that includes radiative transfer of UV photons, and we employ a refinement strategy that allows us to resolve accretion streams in their natural environment to an unprecedented level. For the first time, we self-consistently model self-shielding in the cold streams from the cosmological UV background, which enables us to accurately predict their temperatures, ionization states and Lya luminosities. We find the efficiency of gravitational heating in cold streams in a ~10^11 solar mass halo is around 10-20% throughout most of the halo but reaching much higher values close to the center. As a result most of the Lya luminosity comes from the circumg...

  6. Gunn effect in field-emission phenomena

    Science.gov (United States)

    Litovchenko, V.; Evtukh, A.; Yilmazoglu, O.; Mutamba, K.; Hartnagel, H. L.; Pavlidis, D.

    2005-02-01

    The peculiarities of electron field emission from nanostructured GaN surface have been investigated. The current-voltage characteristics of emission current in Fowler-Nordheim plot show two parts with different slopes. There are emission current oscillations in the changing slope region. As an explanation for the experimental results a model based on the electron-emission analysis from lower (Γ) valley, upper (U) valley, and electron transition between valleys due to heating in electric field has been proposed. The electron affinities for the emission from Γ and U valleys have been determined. The decreased affinities from there valleys have been estimated for quantization in nanostructured GaN.

  7. Forecasting carbon dioxide emissions.

    Science.gov (United States)

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy.

  8. Thermal emissivity of avian eggshells.

    Science.gov (United States)

    Björn, Lars Olof; Bengtson, Sven-Axel; Li, Shaoshan; Hecker, Christoph; Ullah, Saleem; Roos, Arne; Nilsson, Annica M

    2016-04-01

    The hypothesis has been tested that evolution has resulted in lower thermal emissivity of eggs of birds breeding openly in cold climates than of eggs of birds that nest under protective covering or in warmer climates. Directional thermal emissivity has been estimated from directional-hemispherical reflectance spectra. Due to several methodological difficulties the absolute emissivity is not accurately determined, but differences between species are obvious. Most notably, small waders of the genus Calidris, breeding in cold climates on the tundra, and in most cases with uniparental nest attendance, have low directional emissivity of their eggshells, about 0.92 when integration is carried out for wavelengths up to 16μm. Species belonging to Galloanserinae have the highest directional emissivity, about 0.96, of their eggs. No differences due to climate or breeding conditions were found within this group. Eggs of most other birds tested possess intermediate emissivity, but the values for Pica pica and Corvus corone cornix are as low as for Calidris. Large species-dependent differences in spectral reflectance were found at specific wavelengths. For instance, at 4.259μm the directional-hemispherical reflectance for galliforms range from 0.05 to 0.09, while for Fratercula arctica and Fulmarus glacialis it is about 0.3. The reflection peaks at 6.5 and 11.3μm due to calcite are differentially attenuated in different species. In conclusion, the hypothesis that evolution has resulted in lower thermal emissivity of bird eggs being exposed in cold climates is not supported by our results. The emissivity is not clearly related to nesting habits or climate, and it is unlikely that the small differences observed are ecologically important. The spectral differences between eggs that nevertheless exist should be taken into account when using infrared thermometers for estimating the surface temperature of avian eggs.

  9. Credit where due.

    Science.gov (United States)

    Friedman, Steven G

    2016-08-01

    The history of medicine is filled with stories of tireless researchers who failed to get credit for their hard work. Examples of this include Rosalind Franklin, who helped to elucidate the structure of DNA; Frederick Banting, who helped to discover insulin; and Jay McLean, who discovered heparin. The founding of the field of vascular surgery provides one of the most vivid examples of uncredited work. Even though Alexis Carrel was an unpaid, untitled assistant in Charles Guthrie's laboratory, it was Carrel alone who received a Nobel Prize for their work. In an attempt to give credit where due, the reasons for this injustice are described. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  10. Ultraviolet-Bright, High-Redshift ULIRGS

    CERN Document Server

    Colbert, J W; Francis, P; Palunas, P; Williger, G M; Woodgate, B; Colbert, James W.; Teplitz, Harry; Francis, Paul; Palunas, Povilas; Williger, Gerard M.; Woodgate, Bruce

    2006-01-01

    We present Spitzer Space Telescope observations of the z=2.38 lya-emitter over-density associated with galaxy cluster J2143-4423, the largest known structure (110 Mpc) above z=2. We imaged 22 of the 37 known lya-emitters within the filament-like structure, using the MIPS 24um band. We detected 6 of the lya-emitters, including 3 of the 4 clouds of extended (>50 kpc) lyman alpha emission, also known as Lya Blobs. Conversion from rest-wavelength 7um to total far-infrared luminosity using locally derived correlations suggests all the detected sources are in the class of ULIRGs, with some reaching Hyper-LIRG energies. Lya blobs frequently show evidence for interaction, either in HST imaging, or the proximity of multiple MIPS sources within the Lya cloud. This connection suggests that interaction or even mergers may be related to the production of Lya blobs. A connection to mergers does not in itself help explain the origin of the Lya blobs, as most of the suggested mechanisms for creating Lya blobs (starbursts, AG...

  11. Were progenitors of local L* galaxies Lyman-alpha emitters at high redshift?

    CERN Document Server

    Yajima, Hidenobu; Zhu, Qirong; Abel, Tom; Gronwall, Caryl; Ciardullo, Robin

    2011-01-01

    The Lya emission has been observed from galaxies over a redshift span z ~ 0 - 8.6. However, the link between high-redshift Lya emitters (LAEs) and local galaxies is largely unknown. Here, we investigate the Lya properties of progenitors of a local L^{*} galaxy by combining cosmological hydrodynamic simulations with three-dimensional radiative transfer calculations using the new ART^2 code. We find that the modeled galaxies are Lya bright in redshift z= 0 - 10. In particular, the Lya luminosities of some massive progenitors at z ~ 2 - 6 are close to the observed characteristic L_{Lya}^{*} of LAEs in that redshift range. Both Lya photon escape fraction and line equivalent width increase with redshift. The Lya escape fraction correlates with a number of physical properties of the galaxy, such as mass, SFR and metallicity. We find a "viewing-angle scatter" in which the photon escape depends strongly on the galaxy morphology and orientation. Moreover, we find that high-redshift LAEs show blue-shifted Lya line prof...

  12. The Luminosity Function of Lyman alpha Emitters at Redshift z=7.7

    CERN Document Server

    Tilvi, Vithal; Hibon, Pascale; Malhotra, Sangeeta; Wang, Junxian; Veilleux, Sylvain; Swaters, Rob; Probst, Ron; Krug, Hannah; Finkelstein, Steven L; Dickinson, Mark

    2010-01-01

    Lyman alpha (Lya) emission lines should be attenuated in a neutral intergalactic medium (IGM). Therefore the visibility of Lya emitters at high redshifts can serve as a valuable probe of reionization at about the 50% level. We present an imaging search for z=7.7 Lya emitting galaxies using an ultra-narrowband filter (filter width= 9A) on the NEWFIRM imager at the Kitt Peak National Observatory. We found four candidate Lya emitters in a survey volume of 1.4 x 10^4 Mpc^3, with a line flux brighter than 6x10^-18 erg/cm^2/s (5 sigma in 2" aperture). We also performed a detailed Monte-Carlo simulation incorporating the instrumental effects to estimate the expected number of Lya emitters in our survey, and found that we should expect to detect one Lya emitter, assuming a non-evolving Lya luminosity function (LF) between z=6.5 and z=7.7. Even if one of the present candidates is spectroscopically confirmed as a z~8 Lya emitter, it would indicate that there is no significant evolution of the Lya LF from z=3.1 to z~8. ...

  13. Inventory of Greenhouse Gases Emissions from Gasoline and ...

    African Journals Online (AJOL)

    Akorede

    Man-made emissions of greenhouse gases (GHGs) have ... agriculture in Nigeria due to climate change is the reduction ... contributed significantly to the choking air in cities like ...... review with time, utilization and enforcement of emissions.

  14. Positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Muehllehner, Gerd; Karp, Joel S [Department of Radiology, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States)

    2006-07-07

    The developments in positron emission tomography (PET) are reviewed with an emphasis on instrumentation for clinical PET imaging. After a brief summary of positron imaging before the advent of computed tomography, various improvements are highlighted including the move from PET scanners with septa to fully 3D scanners, changes in the preferred scintillators, efforts to improve the energy discrimination, and improvements in attenuation correction. Time-of-flight PET imaging is given special attention due to the recent revival of this technique, which promises significant improvement. Besides technical instrumentation efforts, other factors which influenced the acceptance of clinical PET are also discussed. (review)

  15. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, M.; Illerup, J. B.

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOX, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins and PAH. Since 1990 the fuel consumption...... in stationary combustion has increased by 14% - the fossil fuel consumption however only by 8%. Despite the increased fuel consumption the emission of several pollutants has decreased due to the improved flue gas cleaning technology, improved burner technology and the change of fuel type used. A considerable...... decrease of the SO2, NOX and heavy metal emissions is mainly a result of decreased emissions from large power plants and waste incineration plants. The greenhouse gas emission has decreased 1,3% since 1990. The emission of CH4, however, has increased due to increased use of lean-burn gas engines in CHP...

  16. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, M.; Illerup, J. B.

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are: SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins and PAH. Since 1990 the fuel consumption...... in stationary combustion has increased by 12% - the fossil fuel consumption however only by 6%. Despite the increased fuel consumption the emission of several pollutants have decreased due to the improved flue gas cleaning technology, improved burner technology and the change of fuel type used. A considerable...... decrease of the SO2, NOx and heavy metal emissions is mainly a result of decreased emissions from large power plants and waste incineration plants. The greenhouse gas emission has decreased 1,5% since 1990. The emission of CH4, however, has increased due to increased use of lean-burn gas engines in CHP...

  17. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2007 was 10...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....

  18. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, PCDD/F, HCB and PAH. The CO2 emission in 2011...... of decreased emissions from large power plants and waste incineration plants. The combustion of wood in residential plants has increased considerably until 2007 resulting in increased emission of PAH and particulate matter. The emission of NMVOC has increased since 1990 as a result of both the increased...... combustion of wood in residential plants and the increased emission from lean-burn gas engines. The PCDD/F emission decreased since 1990 due to flue gas cleaning on waste incineration plants....

  19. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2008...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....

  20. On-board gaseous emissions of LPG taxis and estimation of taxi fleet emissions.

    Science.gov (United States)

    Lau, Jason; Hung, W T; Cheung, C S

    2011-11-15

    Instantaneous CO, NO, and HC emissions and exhaust flow rates from four LPG taxis, which adhered to Euro 2-4 emission standards, were measured using a sophisticated portable emission measurement system (PEMS). Instantaneous air/fuel ratios, emission rates, and emission factors at different operating modes were derived to explore the emission characteristics of these four taxis. Results show that gaseous emissions from these four taxis exceed emission standards, due to extended vehicle use and poor maintenance. NO emissions from newer taxis are lower whilst CO and HC emissions of the Euro 4 taxi are similar to those of Euro 2 taxis during idling and low speed travel. The taxis emit lower amounts of gaseous pollutants whilst idling and emit the highest amounts of CO and NO whilst accelerating. Large fluctuations in air/fuel ratios can be observed from the Euro 4 taxi during idling, indicating a malfunction of fuel supply control to the engine. Such fluctuations are not observed from the other taxis. This shows that a Euro 4 taxi is not necessarily cleaner than a Euro 3 taxi. Emission factors derived from on-board measurements are applied to estimate gaseous emissions from the taxi fleet; these results show that emissions are higher during peak hour traffic conditions. An estimate of the taxi fleet's emissions whilst the older taxis are replaced is also calculated. It can be seen that faster replacement of older taxis can lead to reductions in gaseous emissions from the taxi fleet. This study shows that the PEMS is an adequate tool for measuring emissions from LPG vehicles and that there is an urgent need to enforce emission standards on taxis. This study also shows that on-board measurements should be incorporated in the estimation of emissions from other vehicle types. This would result in better emission estimations under local traffic conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Positron Emission Mammotomography with Dual Planar Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mark Smith; Raymond Raylman; Stanislaw Majewski

    2003-06-29

    Positron emission mammography (PEM) is usually performed with two stationary planar detectors above and below a compressed breast. There is image blurring normal to the detectors due to the limited angular range of the lines of response. Positron emission mammotomography (PEM-T) with dual planar detectors rotating about the breast can obtain complete angular sampling and has the potential to improve activity estimation.

  2. Spontaneous emission from active dielectric microstructures

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Tromborg, Bjarne

    2001-01-01

    and engineered due to the dependence of the emission rate on the location and polarisation of the emitters in the structure. This paper addresses the methods of quantum electrodynamics of dielectric media which enable calculation of the local rate of spontaneous emission in active microstructures....

  3. Graviton Emission and Absorption by Atomic Hydrogen

    CERN Document Server

    Rothman, S B T

    2006-01-01

    Graviton absorption cross sections and emission rates for hydrogen are calculated by both semi-classical and field theoretic methods. We point out several mistakes in the literature concerning spontaneous emission of gravitons and related phenomena, some of which are due to a subtle issue concerning gauge invariance of the linearized interaction Hamiltonian.

  4. Elemental composition of current automotive braking materials and derived air emission factors

    NARCIS (Netherlands)

    Hulskotte, J.H.J.; Roskam, G.D.; Denier van der Gon, H.A.C.

    2014-01-01

    Wear-related PM emissions are an important constituent of total PM emissions from road transport. Due to ongoing (further) exhaust emission reduction wear emissions may become the dominant PM source from road transport in the near future. The chemical composition of the wear emissions is crucial inf

  5. A new method to calculate monthly CO emissions using MOPITT satellite data

    Institute of Scientific and Technical Information of China (English)

    LIN YunPing; ZHAO ChunSheng; PENG Li; FANG YuanYuan

    2007-01-01

    A new method is developed to calculate monthly CO emission data using MOZART modeled and MOPITT observed CO data in 2004. New CO emission data were obtained with budget analysis of the processes controlling CO concentration such as surface emission, transport, chemical transform and dry deposition. MOPITT data were used to constrain the model simulation. New CO emission data agree well with Horowitz's emissions in the spatial distributions. Horowitz's emissions are found to underestimate CO emissions significantly in the industrial areas of Asia and North America, where high CO emissions are mainly due to the anthropogenic activities. New CO emissions can better reflect the more recent CO actual emissions than Horowitz's.

  6. Emission Inventory for Fugitive Emissions in Denmark

    DEFF Research Database (Denmark)

    Plejdrup, Marlene Schmidt; Nielsen, Ole-Kenneth; Nielsen, Malene

    This report presents the methodology and data used in the Danish inventory of fugitive emissions from fuels for the years until 2007. The inventory of fugitive emissions includes CO2, CH4, N2O, NOx, CO, NMVOC, SO2, dioxin, PAH and particulate matter. In 2007 the total Danish emission of greenhouse...

  7. Mapping the Polarization of the Radio-Loud Ly$\\alpha$ Nebula B3 J2330+3927

    CERN Document Server

    You, Chang; Smith, Paul; Yang, Yujin; Kim, Eunchong; Jannuzi, Buell; Prescott, Moire K M; Matsuda, Yuichi; Lee, Myung Gyoon

    2016-01-01

    Lya nebulae, or "Lya blobs", are extended (up to ~100 kpc), bright (L[Lya] > 10^43 erg/s) clouds of Lya emitting gas that tend to lie in overdense regions at z ~ 2--5. The origin of the Lya emission remains unknown, but recent theoretical work suggests that measuring the polarization might discriminate among powering mechanisms. Here we present the first narrowband, imaging polarimetry of a radio-loud Lya nebula, B3 J2330+3927 at z=3.09, with an embedded active galactic nucleus (AGN). The AGN lies near the blob's Lya emission peak and its radio lobes align roughly with the blob's major axis. With the SPOL polarimeter on the 6.5m MMT telescope, we map the total (Lya + continuum) polarization in a grid of circular apertures of radius 0.6" (4.4kpc), detecting a significant (>2sigma) polarization fraction P in nine apertures and achieving strong upper-limits (as low as 2%) elsewhere. P increases from <2% at ~5kpc from the blob center to ~17% at ~15-25kpc. The detections are distributed asymmetrically, roughly ...

  8. Methane Emissions from Upland Forests

    Science.gov (United States)

    Megonigal, Patrick; Pitz, Scott; Wang, Zhi-Ping

    2016-04-01

    Global budgets ascribe 4-10% of atmospheric methane sinks to upland soils and assume that soils are the sole surface for methane exchange between upland forests and the atmosphere. The dogma that upland forests are uniformly atmospheric methane sinks was challenged a decade ago by the discovery of abiotic methane production from plant tissue. Subsequently a variety of relatively cryptic microbial and non-microbial methane sources have been proposed that have the potential to emit methane in upland forests. Despite the accumulating evidence of potential methane sources, there are few data demonstrating actual emissions of methane from a plant surface in an upland forest. We report direct observations of methane emissions from upland tree stems in two temperate forests. Stem methane emissions were observed from several tree species that dominate a forest located on the mid-Atlantic coast of North America (Maryland, USA). Stem emissions occurred throughout the growing season while soils adjacent to the trees simultaneously consumed methane. Scaling fluxes by stem surface area suggested the forest was a net methane source during a wet period in June, and that stem emissions offset 5% of the soil methane sink on an annual basis. High frequency measurements revealed diurnal cycles in stem methane emission rates, pointing to soils as the methane source and transpiration as the most likely pathway for gas transport. Similar observations were made in an upland forest in Beijing, China. However, in this case the evidence suggested the methane was not produced in soils, but in the heartwood by microbial or non-microbial processes. These data challenge the concept that forests are uniform sinks of methane, and suggest that upland forests are smaller methane sinks than previously estimated due to stem emissions. Tree emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration.

  9. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-10-01

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

  10. Anthropogenic sulfur dioxide emissions: 1850–2005

    Directory of Open Access Journals (Sweden)

    S. J. Smith

    2011-02-01

    Full Text Available Sulfur aerosols impact human health, ecosystems, agriculture, and global and regional climate. A new annual estimate of anthropogenic global and regional sulfur dioxide emissions has been constructed spanning the period 1850–2005 using a bottom-up mass balance method, calibrated to country-level inventory data. Global emissions peaked in the early 1970s and decreased until 2000, with an increase in recent years due to increased emissions in China, international shipping, and developing countries in general. An uncertainty analysis was conducted including both random and systemic uncertainties. The overall global uncertainty in sulfur dioxide emissions is relatively small, but regional uncertainties ranged up to 30%. The largest contributors to uncertainty at present are emissions from China and international shipping. Emissions were distributed on a 0.5° grid by sector for use in coordinated climate model experiments.

  11. Quantification of acetone emission from pine plants

    Institute of Scientific and Technical Information of China (English)

    SHAO; Min; (邵敏); Jürgen; Wildt

    2002-01-01

    Acetone emission from pine plants (pinus sylvestris) is measured by continuously stirred tank reactor. Under a constant light intensity, acetone emission rates increase exponentially with leaf temperature. When leaf temperature is kept constant, acetone emission increases with light intensity. And acetone emission in darkness is also detected. Acetone emitted from pine is quickly labeled by 13C when the plants are exposed to air with 630 mg/m3 13CO2. However, no more than 20% of acetone is 13C labeled. Acetone emission from pine may be due to both leaf temperature- controlled process and light intensity-controlled process. Based on these understandings, an algorithm is used to describe the short term acetone emission rates from pine.

  12. Drivers of the Growth in Global Greenhouse Gas Emissions

    NARCIS (Netherlands)

    Arto, Inaki; Dietzenbacher, Erik

    2014-01-01

    Greenhouse gas emissions increased by 8.9 Gigatons CO2 equivalent (Gt) in the period 1995-2008. A phenomenon that has received due attention is the upsurge of emission transfers via international trade. A question that has remained unanswered is whether trade changes have affected global emissions.

  13. Research of Environment-friendly Low Emissivity Glass

    Institute of Scientific and Technical Information of China (English)

    YU Feng

    2007-01-01

    The environment-friendly glasses which integrate function and structure were introduced, among these glasses can save energy very efficiently due to its low infrared emissivity. The fundamental principle of the low emissivity glass and the research progress of this kind glass were analyzed. Meanwhile,high performance and low applied development trend of emissivity glass were reviewed.

  14. Dioxin air emission inventory 1990-2004

    Energy Technology Data Exchange (ETDEWEB)

    Capral Henriksen, T.; Illerup, J.B.; Nielsen, Ole-Kenneth [DMU, Dept. of Policy Analysis (Denmark)

    2006-12-15

    The present Danish dioxin air emission inventory shows that the emission has been reduced from 68.6 g I-TEQ in 1990 to 22.0 g I-TEQ in 2004, or about 68% over this period. Most of the significant reductions have been achieved in the industrial sector, where emissions have been reduced from 14.67 g I-TEQ in 1990 to 0.17 g I-TEQ in 2004; a reduction of almost 99%. Lower emissions from steel and aluminium reclamation industries form the major part of the reduction within industry. Emissions from waste incineration reduced from 32.5 g I-TEQ in 1990 to 2.1 g ITEQ in 2004; which is approx. 94%. This is due to installation of dioxin abatement equipment in incineration plants. The most important source of emission in 2004 is residential wood combustion, at 8.5 g I-TEQ, or around 40% of the total emission. In 2004, accidental fires, which are estimated to emit 6.1 g I-TEQ/year, are the second most important source, contributing with around 28% of the total emission. The present dioxin emission inventory for Denmark shows how emissions in 2004 come from sources other than waste incineration plants and industry, which were the largest sources in 1990. (au)

  15. Danish emission inventories for road transport and other mobile sources

    DEFF Research Database (Denmark)

    Winther, M.

    gasoline catalyst cars. For other mobile sources the fuel use, CO2 and NOX emissions have decreased with 15% from 1985 to 2002, and the PM emission decline is in the order of 13%. For SO2 the emission drop is 74% from 1985 to 2002, due to gradually lower fuel sulphur contents. In the same period...... the emissions of NMVOC and CO has increased with 32 and 6%, mainly due to the increased use of small gasoline boats. Uncertainties for the emissions and trends have been estimated...

  16. Ion cyclotron emission by spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa, O. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Gresillon, D. [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises

    1994-07-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs.

  17. Explaining Dutch emissions of CO2; a decomposition analysis

    OpenAIRE

    Alex Hoen; Machiel Mulder

    2003-01-01

    Decomposition of CO2 data of the Netherlands shows that much progress has been made with reduction of CO2 emissions by changing to less CO2 intensive technologies. Moreover, demand shifted to products that are produced with less CO2 emission. Further, shifts in the inputs needed in the production process also managed to decrease the CO2 emissions. These effects, however, were more than compensated by increased CO2 emission due to economic growth. Especially growth in exports led to substantia...

  18. The carbon emissions of Chinese cities

    Science.gov (United States)

    Wang, H.; Zhang, R.; Liu, M.; Bi, J.

    2012-07-01

    As increasing urbanization has become a national policy priority for economic growth in China, cities have become important players in efforts to reduce carbon emissions. However, their efforts have been hampered by the lack of specific and comparable carbon emission inventories. Comprehensive carbon emission inventories for twelve Chinese cities, which present both a relatively current snapshot and also show how emissions have changed over the past several years, were developed using a bottom-up approach. Carbon emissions in most Chinese cities rose along with economic growth from 2004 to 2008. Yet per capita carbon emissions varied between the highest and lowest emitting cities by a factor of nearly 7. Average contributions of sectors to per capita emissions for all Chinese cities were 65.1% for industrial energy consumption, 10.1% for industrial processes, 10.4% for transportation, 7.7% for household energy consumption, 4.2% for commercial energy consumption and 2.5% for waste processing. However, these shares are characterized by considerable variability due to city-specific factors. The levels of per capita carbon emissions in China's cities were higher than we anticipated before comparing them with the average of ten cities in other parts of the world. This is mainly due to the major contribution of the industry sector in Chinese cities.

  19. The carbon emissions of Chinese cities

    Directory of Open Access Journals (Sweden)

    H. Wang

    2012-03-01

    Full Text Available As increasing urbanization has become a national policy priority for economic growth in China, cities have become important players in efforts to reduce carbon emissions. However, their efforts have been hampered by the lack of specific and comparable carbon emission inventories. Comprehensive carbon emission inventories, which present both a relatively current snapshot and also show how emissions have changed over the past several years, of twelve Chinese cities were developed using bottom-up approach. Carbon emissions in most of Chinese cities rose along with economic growth from 2004 to 2008. Yet per capita carbon emissions varied between the highest and lowest emitting cities by a factor of nearly 7. Average per capita carbon emissions varied across sectors, including industrial energy consumption (64.3%, industrial processes (10.2%, transportation (10.6%, household energy consumption (8.0%, commercial energy consumption (4.3% and waste processing (2.5%. The levels of per capita carbon emissions in China's cities were higher than we anticipated before comparing them with the average of global cities. This is mainly due to the major contribution of industry sector encompassing industrial energy consumption and industrial processes to the total carbon emissions of Chinese cities.

  20. Ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2012-01-01

    The NEC (National Emission Ceiling) directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the la......The NEC (National Emission Ceiling) directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries...

  1. The primordial helium abundance from updated emissivities

    CERN Document Server

    Aver, Erik; Porter, R L; Skillman, Evan D

    2013-01-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y_p. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, & Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, & Stasinska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y_p. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increase...

  2. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-04-01

    Full Text Available The Arctic is a sensitive region in terms of climate change and a rich natural resource for global economic activity. Arctic shipping is an important contributor to the region's anthropogenic air emissions, including black carbon – a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow. These emissions are projected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. To understand the impacts of these increased emissions, scientists and modelers require high-resolution, geospatial emissions inventories that can be used for regional assessment modeling. This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050 scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. Short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing; a first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing due to Arctic ships by at least 17% compared to warming from these vessels' CO2 emissions (~42 000 gigagrams. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  3. Emissions Modeling Clearinghouse

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Emissions Modeling Clearinghouse (EMCH) supports and promotes emissions modeling activities both internal and external to the EPA. Through this site, the EPA...

  4. Walkable dual emissions

    National Research Council Canada - National Science Library

    Xu, Hai-Bing; Jiao, Peng-Chong; Kang, Bin; Deng, Jian-Guo; Zhang, Yan

    2013-01-01

    Walkable dual emissions, in which the emission bands of the walker reversibly cross or leave those of the stationary ones depending on temperature and concentration, have been demonstrated in cyclic...

  5. National Emission Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Emission Inventory contains measured, modeled, and estimated data for emissions of all known source categories in the US (stationary sources, fires,...

  6. World Emission RETRO ANTHRO

    Data.gov (United States)

    Washington University St Louis — Anthropogenic and vegetation fire emissions data were generated monthly covering a period of 1960 to 2000. Anthropogenic emissions in the RETRO inventory are derived...

  7. Emissions & Measurements - Black Carbon

    Science.gov (United States)

    Emissions and Measurement (EM) research activities performed within the National Risk Management Research Lab NRMRL) of EPA's Office of Research and Development (ORD) support measurement and laboratory analysis approaches to accurately characterize source emissions, and near sour...

  8. What Is Emissions Trading?

    Science.gov (United States)

    Learn the basics about how emissions trading uses a market-based policy tool used to control large amounts of pollution emissions from a group of sources in order to protect human health and the environment.

  9. National Emission Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Emission Inventory contains measured, modeled, and estimated data for emissions of all known source categories in the US (stationary sources, fires,...

  10. Predicting vehicular emissions in high spatial resolution using pervasively measured transportation data and microscopic emissions model

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, Marguerite; Sobolevsky, Stanislav; Kang, Chaogui; Robinson, Prudence; Corti, Andrea; Szell, Michael; Streets, David; Lu, Zifeng; Britter, Rex; Barrett, Steven R. H.; Ratti, Carlo

    2016-06-07

    Air pollution related to traffic emissions pose an especially significant problem in cities; this is due to its adverse impact on human health and well-being. Previous studies which have aimed to quantify emissions from the transportation sector have been limited by either simulated or coarsely resolved traffic volume data. Emissions inventories form the basis of urban pollution models, therefore in this study, Global Positioning System (GPS) trajectory data from a taxi fleet of over 15,000 vehicles were analyzed with the aim of predicting air pollution emissions for Singapore. This novel approach enabled the quantification of instantaneous drive cycle parameters in high spatio-temporal resolution, which provided the basis for a microscopic emissions model. Carbon dioxide (CO2), nitrogen oxides (NOx), volatile organic compounds (VOCs) and particulate matter (PM) emissions were thus estimated. Highly localized areas of elevated emissions levels were identified, with a spatio-temporal precision not possible with previously used methods for estimating emissions. Relatively higher emissions areas were mainly concentrated in a few districts that were the Singapore Downtown Core area, to the north of the central urban region and to the east of it. Daily emissions quantified for the total motor vehicle population of Singapore were found to be comparable to another emissions dataset Results demonstrated that high resolution spatio-temporal vehicle traces detected using GPS in large taxi fleets could be used to infer highly localized areas of elevated acceleration and air pollution emissions in cities, and may become a complement to traditional emission estimates, especially in emerging cities and countries where reliable fine-grained urban air quality data is not easily available. This is the first study of its kind to investigate measured microscopic vehicle movement in tandem with microscopic emissions modeling for a substantial study domain.

  11. Predicting vehicular emissions in high spatial resolution using pervasively measured transportation data and microscopic emissions model

    Science.gov (United States)

    Nyhan, Marguerite; Sobolevsky, Stanislav; Kang, Chaogui; Robinson, Prudence; Corti, Andrea; Szell, Michael; Streets, David; Lu, Zifeng; Britter, Rex; Barrett, Steven R. H.; Ratti, Carlo

    2016-09-01

    Air pollution related to traffic emissions pose an especially significant problem in cities; this is due to its adverse impact on human health and well-being. Previous studies which have aimed to quantify emissions from the transportation sector have been limited by either simulated or coarsely resolved traffic volume data. Emissions inventories form the basis of urban pollution models, therefore in this study, Global Positioning System (GPS) trajectory data from a taxi fleet of over 15,000 vehicles were analyzed with the aim of predicting air pollution emissions for Singapore. This novel approach enabled the quantification of instantaneous drive cycle parameters in high spatio-temporal resolution, which provided the basis for a microscopic emissions model. Carbon dioxide (CO2), nitrogen oxides (NOx), volatile organic compounds (VOCs) and particulate matter (PM) emissions were thus estimated. Highly localized areas of elevated emissions levels were identified, with a spatio-temporal precision not possible with previously used methods for estimating emissions. Relatively higher emissions areas were mainly concentrated in a few districts that were the Singapore Downtown Core area, to the north of the central urban region and to the east of it. Daily emissions quantified for the total motor vehicle population of Singapore were found to be comparable to another emissions dataset. Results demonstrated that high-resolution spatio-temporal vehicle traces detected using GPS in large taxi fleets could be used to infer highly localized areas of elevated acceleration and air pollution emissions in cities, and may become a complement to traditional emission estimates, especially in emerging cities and countries where reliable fine-grained urban air quality data is not easily available. This is the first study of its kind to investigate measured microscopic vehicle movement in tandem with microscopic emissions modeling for a substantial study domain.

  12. Danish emission inventories for road transport and other mobile sources

    DEFF Research Database (Denmark)

    Winther, M.

    gasoline catalyst cars. For other mobile sources the fuel use, CO2 and NOX emissions have decreased with 15% from 1985 to 2002, and the PM emission decline is in the order of 13%. For SO2 the emission drop is 74% from 1985 to 2002, due to gradually lower fuel sulphur contents. In the same period...... the emissions of NMVOC and CO has increased with 32 and 6%, mainly due to the increased use of small gasoline boats. Uncertainties for the emissions and trends have been estimated......This report explains the parts of the Danish inventories related to road transport and other mobile sources. Emission results for CO2, CH4, N2O, SO2, NOX, NMVOC, CO, particulate matter (PM), heavy metals, dioxins and PAH are shown from 1985 to 2002. In this period the fuel use and CO2 emissions...

  13. Emission and Absorption Entropy Generation in Semiconductors

    DEFF Research Database (Denmark)

    Reck, Kasper; Varpula, Aapo; Prunnila, Mika

    2013-01-01

    While emission and absorption entropy generation is well known in black bodies, it has not previously been studied in semiconductors, even though semiconductors are widely used for solar light absorption in modern solar cells [1]. We present an analysis of the entropy generation in semiconductor...... materials due to emission and absorption of electromagnetic radiation. It is shown that the emission and absorption entropy generation reduces the fundamental limit on the efficiency of any semiconductor solar cell even further than the Landsberg limit. The results are derived from purely thermodynamical...

  14. Global civil aviation black carbon emissions.

    Science.gov (United States)

    Stettler, Marc E J; Boies, Adam M; Petzold, Andreas; Barrett, Steven R H

    2013-09-17

    Aircraft black carbon (BC) emissions contribute to climate forcing, but few estimates of BC emitted by aircraft at cruise exist. For the majority of aircraft engines the only BC-related measurement available is smoke number (SN)-a filter based optical method designed to measure near-ground plume visibility, not mass. While the first order approximation (FOA3) technique has been developed to estimate BC mass emissions normalized by fuel burn [EI(BC)] from SN, it is shown that it underestimates EI(BC) by >90% in 35% of directly measured cases (R(2) = -0.10). As there are no plans to measure BC emissions from all existing certified engines-which will be in service for several decades-it is necessary to estimate EI(BC) for existing aircraft on the ground and at cruise. An alternative method, called FOX, that is independent of the SN is developed to estimate BC emissions. Estimates of EI(BC) at ground level are significantly improved (R(2) = 0.68), whereas estimates at cruise are within 30% of measurements. Implementing this approach for global civil aviation estimated aircraft BC emissions are revised upward by a factor of ~3. Direct radiative forcing (RF) due to aviation BC emissions is estimated to be ~9.5 mW/m(2), equivalent to ~1/3 of the current RF due to aviation CO2 emissions.

  15. PM Emissions in a Urban Context

    Directory of Open Access Journals (Sweden)

    Enrico Brizio

    2007-01-01

    Full Text Available Within a urban environment, three different sources of particulate matter should be considered: heating plants using different combustibles (natural gas, gas oil, fuel oil, wood, industrial plants placed in the surrounding area, traffic. While the effects of the first two origins can be easily calculated on the basis of existing emission factors, the PM emissions from traffic are of two types, exhaust and non-exhaust. The latter type of emission is due to vehicle components’ wear (tyres, brakes, road abrasion and dust re-suspension and its quantification is not straightforward, as the variability of the corresponding emission factors found in literature demonstrates. In this paper we tried to calculate the total PM emission factors due to traffic by means of the measured PM concentrations for a 50,000 inhabitants town in NW Italy. At the same time we tried to assess the different contributions to the air quality of the town due to the other emission sources, namely heating and industrial plants, in order to understand who is the main responsible of the existing critical situation and to get some general information on the positive effect obtainable through different intervention policy.

  16. Constraining CO emission estimates using atmospheric observations

    Science.gov (United States)

    Hooghiemstra, P. B.

    2012-06-01

    We apply a four-dimensional variational (4D-Var) data assimilation system to optimize carbon monoxide (CO) emissions and to reduce the uncertainty of emission estimates from individual sources using the chemistry transport model TM5. In the first study only a limited amount of surface network observations from the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL) Global Monitoring Division (GMD) is used to test the 4D-Var system. Uncertainty reduction up to 60% in yearly emissions is observed over well-constrained regions and the inferred emissions compare well with recent studies for 2004. However, since the observations only constrain total CO emissions, the 4D-Var system has difficulties separating anthropogenic and biogenic sources in particular. The inferred emissions are validated with NOAA aircraft data over North America and the agreement is significantly improved from the prior to posterior simulation. Validation with the Measurements Of Pollution In The Troposphere (MOPITT) instrument shows a slight improved agreement over the well-constrained Northern Hemisphere and in the tropics (except for the African continent). However, the model simulation with posterior emissions underestimates MOPITT CO total columns on the remote Southern Hemisphere (SH) by about 10%. This is caused by a reduction in SH CO sources mainly due to surface stations on the high southern latitudes. In the second study, we compare two global inversions to estimate carbon monoxide (CO) emissions for 2004. Either surface flask observations from NOAA or CO total columns from the MOPITT instrument are assimilated in a 4D-Var framework. In the Southern Hemisphere (SH) three important findings are reported. First, due to their different vertical sensitivity, the stations-only inversion increases SH biomass burning emissions by 108 Tg CO/yr more than the MOPITT-only inversion. Conversely, the MOPITT-only inversion results in SH natural emissions

  17. Ammonia emissions in Europe, part II: How ammonia emission abatement strategies affect secondary aerosols

    Science.gov (United States)

    Backes, Anna M.; Aulinger, Armin; Bieser, Johannes; Matthias, Volker; Quante, Markus

    2016-02-01

    In central Europe, ammonium sulphate and ammonium nitrate make up a large fraction of fine particles which pose a threat to human health. Most studies on air pollution through particulate matter investigate the influence of emission reductions of sulphur- and nitrogen oxides on aerosol concentration. Here, we focus on the influence of ammonia (NH3) emissions. Emission scenarios have been created on the basis of the improved ammonia emission parameterization implemented in the SMOKE for Europe and CMAQ model systems described in part I of this study. This includes emissions based on future European legislation (the National Emission Ceilings) as well as a dynamic evaluation of the influence of different agricultural sectors (e.g. animal husbandry) on particle formation. The study compares the concentrations of NH3, NH4+, NO3 -, sulphur compounds and the total concentration of particles in winter and summer for a political-, technical- and behavioural scenario. It was found that a reduction of ammonia emissions by 50% lead to a 24% reduction of the total PM2.5 concentrations in northwest Europe. The observed reduction was mainly driven by reduced formation of ammonium nitrate. Moreover, emission reductions during winter had a larger impact than during the rest of the year. This leads to the conclusion that a reduction of the ammonia emissions from the agricultural sector related to animal husbandry could be more efficient than the reduction from other sectors due to its larger share in winter ammonia emissions.

  18. Emissions Of Greenhouse Gases From Rice Agriculture

    Energy Technology Data Exchange (ETDEWEB)

    M. Aslam K. Khalil

    2009-07-16

    This project produced detailed data on the processes that affect methane and nitrous oxide emissions from rice agriculture and their inter-relationships. It defines the shifting roles and potential future of these gases in causing global warming and the benefits and tradeoffs of reducing emissions. The major results include: 1). Mechanisms and Processes Leading to Methane Emissions are Delineated. Our experiments have tested the standard model of methane emissions from rice fields and found new results on the processes that control the flux. A mathematical mass balance model was used to unravel the production, oxidation and transport of methane from rice. The results suggested that when large amounts of organic matter are applied, the additional flux that is observed is due to both greater production and reduced oxidation of methane. 2). Methane Emissions From China Have Been Decreasing Over the Last Two Decades. We have calculated that methane emissions from rice fields have been falling in recent decades. This decrease is particularly large in China. While some of this is due to reduced area of rice agriculture, the bigger effect is from the reduction in the emission factor which is the annual amount of methane emitted per hectare of rice. The two most important changes that cause this decreasing emission from China are the reduced use of organic amendments which have been replaced by commercial nitrogen fertilizers, and the increased practice of intermittent flooding as greater demands are placed on water resources. 3). Global Methane Emissions Have Been Constant For More Than 20 Years. While the concentrations of methane in the atmosphere have been leveling off in recent years, our studies show that this is caused by a near constant total global source of methane for the last 20 years or more. This is probably because as some anthropogenic sources have increased, others, such as the rice agriculture source, have fallen. Changes in natural emissions appear small

  19. Conducting Due Diligence in China

    Institute of Scientific and Technical Information of China (English)

    CHRIS; DEVONSHIRE-ELLIS

    2008-01-01

    Ninety percent of problems when set- ting up business in China can be avoided by the deployment of due diligence at the front end of the investment planning.Here we point out some of the areas that can hinder a sensible approach to due diligence,the hidden risks and basic checks.The process does not have to be expensive. Land use rights These relate to the status of the land on which your Chinese partner has his prem-

  20. Sonification of acoustic emission data

    Science.gov (United States)

    Raith, Manuel; Große, Christian

    2014-05-01

    While loading different specimens, acoustic emissions appear due to micro crack formation or friction of already existing crack edges. These acoustic emissions can be recorded using suitable ultrasonic transducers and transient recorders. The analysis of acoustic emissions can be used to investigate the mechanical behavior of different specimens under load. Our working group has undertaken several experiments, monitored with acoustic emission techniques. Different materials such as natural stone, concrete, wood, steel, carbon composites and bone were investigated. Also the experimental setup has been varied. Fire-spalling experiments on ultrahigh performance concrete and pullout experiments on bonded anchors have been carried out. Furthermore uniaxial compression tests on natural stone and animal bone had been conducted. The analysis tools include not only the counting of events but the analysis of full waveforms. Powerful localization algorithms and automatic onset picking techniques (based on Akaikes Information Criterion) were established to handle the huge amount of data. Up to several thousand events were recorded during experiments of a few minutes. More sophisticated techniques like moment tensor inversion have been established on this relatively small scale as well. Problems are related to the amount of data but also to signal-to-noise quality, boundary conditions (reflections) sensor characteristics and unknown and changing Greens functions of the media. Some of the acoustic emissions recorded during these experiments had been transferred into audio range. The transformation into the audio range was done using Matlab. It is the aim of the sonification to establish a tool that is on one hand able to help controlling the experiment in-situ and probably adjust the load parameters according to the number and intensity of the acoustic emissions. On the other hand sonification can help to improve the understanding of acoustic emission techniques for training

  1. AIRFORCE. Aircraft emissions and radiative forcing from emissions

    Energy Technology Data Exchange (ETDEWEB)

    Meijer, E.W.; Kelder, H.; Velthoven, P.F.J. van; Wauben, W.M.F. [Royal Netherlands Meteorological Inst., De Bilt (Netherlands); Beck, J.P.; Velders, G.J.M. [National Inst. of Public Health and the Environment, Bilthoven (Netherlands); Lelieveld, J.; Scheeren, B.A. [Institute of Marine and Atmospheric Research Utrecht (Netherlands)

    1997-12-31

    The Dutch AIRFORCE project focuses on the effects of subsonic aircraft emissions on the chemical composition of the atmosphere and subsequent radiative forcing. It includes measurements in the tropopause region and the modelling of exhaust plumes and large-scale effects. An aircraft exhaust plume model has been developed to study plume processes. The results of the plume model are used in the global transport chemistry model CTMK to determine large-scale effects of plume processes. Due to the efficient conversion of NO{sub x} into HNO{sub 3} inside aircraft exhaust plumes, a decrease of about 25% of the O{sub 3} perturbation was found in the NAFC at 200 hPa in July. Measurements of hydrocarbons revealed a dominant role of the anthropogenic continental emissions of light hydrocarbons in the tropopause region. (author) 20 refs.

  2. Selection of emission factor standards for estimating emissions from diesel construction equipment in building construction in the Australian context.

    Science.gov (United States)

    Zhang, Guomin; Sandanayake, Malindu; Setunge, Sujeeva; Li, Chunqing; Fang, Jun

    2017-02-01

    Emissions from equipment usage and transportation at the construction stage are classified as the direct emissions which include both greenhouse gas (GHG) and non-GHG emissions due to partial combustion of fuel. Unavailability of a reliable and complete inventory restricts an accurate emission evaluation on construction work. The study attempts to review emission factor standards readily available worldwide for estimating emissions from construction equipment. Emission factors published by United States Environmental Protection Agency (US EPA), Australian National Greenhouse Accounts (AUS NGA), Intergovernmental Panel on Climate Change (IPCC) and European Environmental Agency (EEA) are critically reviewed to identify their strengths and weaknesses. A selection process based on the availability and applicability is then developed to help identify the most suitable emission factor standards for estimating emissions from construction equipment in the Australian context. A case study indicates that a fuel based emission factor is more suitable for GHG emission estimation and a time based emission factor is more appropriate for estimation of non-GHG emissions. However, the selection of emission factor standards also depends on factors like the place of analysis (country of origin), data availability and the scope of analysis. Therefore, suitable modifications and assumptions should be incorporated in order to represent these factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Projecting human development and CO2 emissions

    CERN Document Server

    Costa, Luís; Kropp, Jürgen P

    2012-01-01

    We estimate cumulative CO2 emissions during the period 2000 to 2050 from developed and developing countries based on the empirical relationship between CO2 per capita emissions (due to fossil fuel combustion and cement production) and corresponding HDI. In order to project per capita emissions of individual countries we make three assumptions which are detailed below. First, we use logistic regressions to fit and extrapolate the HDI on a country level as a function of time. This is mainly motivated by the fact that the HDI is bounded between 0 and 1 and that it decelerates as it approaches 1. Second, we employ for individual countries the correlations between CO2 per capita emissions and HDI in order to extrapolate their emissions. This is an ergodic assumption. Third, we let countries with incomplete data records evolve similarly as their close neighbors (in the emissions-HDI plane, see Fig. 1 in the main text) with complete time series of CO2 per capita emissions and HDI. Country-based emissions estimates a...

  4. Shipping emissions in ports

    OpenAIRE

    2014-01-01

    Shipping emissions in ports are substantial, accounting for 18 million tonnes of CO2 emissions, 0.4 million tonnes of NOx, 0.2 million of SOx and 0.03 million tonnes of PM10 in 2011. Around 85% of emissions come from containerships and tankers. Containerships have short port stays, but high emissions during these stays. Most of CO2 emissions in ports from shipping are in Asia and Europe (58%), but this share is low compared to their share of port calls (70%). European ports have much less emi...

  5. International emissions trading

    DEFF Research Database (Denmark)

    Boom, Jan Tjeerd

    This thesis discusses the design and political acceptability of international emissions trading. It is shown that there are several designs options for emissions trading at the national level that have a different impact on output and thereby related factors such as employment and consumer prices....... The differences in impact of the design make that governments may prefer different designs of emissions trading in different situations. The thesis furthermore establishes that international emissions trading may lead to higher overall emissions, which may make it a less attractive instrument....

  6. Phonon-assisted electron emission from individual carbon nanotubes.

    Science.gov (United States)

    Wei, Xianlong; Golberg, Dmitri; Chen, Qing; Bando, Yoshio; Peng, Lianmao

    2011-02-09

    A question of how electrons can escape from one-atom-thick surfaces has seldom been studied and is still not properly answered. Herein, lateral electron emission from a one-atom-thick surface is thoroughly studied for the first time. We study electron emission from side surface of individual electrically biased carbon nanotubes (CNTs) both experimentally and theoretically and discover a new electron emission mechanism named phonon-assisted electron emission. A kinetic model based on coupled Boltzmann equations of electrons and optical phonons is proposed and well describes experimentally measured lateral electron emission from CNTs. It is shown that the electrons moving along a biased CNT can overflow from the one-atom-thick surface due to the absorption of hot forward-scattering optical phonons. A low working voltage, high emission density, and side emission character make phonon-assisted electron emission primarily promising in electron source applications.

  7. Effect of shipping emissions on European ground-level ozone

    Science.gov (United States)

    Stergiou, Ioannis; -Eleni Sotiropoulou, Rafaella; Tagaris, Efthimios

    2017-04-01

    Shipping emissions contribution to the global nitrogen oxides emissions is about 15%, affecting ozone formation and the chemical composition of the atmosphere. The objective of this study is to assess the impact of shipping emissions on ozone levels over Europe suggesting regions where air quality degradation due to shipping emissions dominates against the rest of the anthropogenic source emissions. Ranking the importance of the Standard Nomenclature for Air Pollution (SNAP) categories on ozone mixing ratio, road transport has the major impact followed by other mobile sources, power generation, and industrial combustion sectors. All other sectors have a minor impact, therefor, our analysis is focused on these four emission categories. Results suggest that shipping emissions seem to play an important role on ozone levels compared to road transport sector near the coastal zone, while they could partly offset the benefits from the emissions reduction of other mobile sources, power generation and industrial combustion sources, over a great part of the European land.

  8. Source Attribution of Methane Emissions in Northeastern Colorado Using Ammonia to Methane Emission Ratios

    Science.gov (United States)

    Eilerman, S. J.; Neuman, J. A.; Peischl, J.; Aikin, K. C.; Ryerson, T. B.; Perring, A. E.; Robinson, E. S.; Holloway, M.; Trainer, M.

    2015-12-01

    Due to recent advances in extraction technology, oil and natural gas extraction and processing in the Denver-Julesburg basin has increased substantially in the past decade. Northeastern Colorado is also home to over 250 concentrated animal feeding operations (CAFOs), capable of hosting over 2 million head of ruminant livestock (cattle and sheep). Because of methane's high Global Warming Potential, quantification and attribution of methane emissions from oil and gas development and agricultural activity are important for guiding greenhouse gas emission policy. However, due to the co-location of these different sources, top-down measurements of methane are often unable to attribute emissions to a specific source or sector. In this work, we evaluate the ammonia:methane emission ratio directly downwind of CAFOs using a mobile laboratory. Several CAFOs were chosen for periodic study over a 12-month period to identify diurnal and seasonal variation in the emission ratio as well as differences due to livestock type. Using this knowledge of the agricultural ammonia:methane emission ratio, aircraft measurements of ammonia and methane over oil and gas basins in the western US during the Shale Oil and Natural Gas Nexus (SONGNEX) field campaign in March and April 2015 can be used for source attribution of methane emissions.

  9. Stroke due to Hematologic Aspects

    Institute of Scientific and Technical Information of China (English)

    刘泽霖

    2004-01-01

    @@ Stroke due to ‘cerebral vein thrombosis' (CVT) is commonly used to refer to thrombosis of the cerebral venous system, including either dural venous sinuses, or deep and superficial (cortical) cerebral veins. CVT are frightening events due to the severity of their clinical manifestations and their high mortality rate (up to 30% in some casereports).The clinical signs and symptoms of CVT are relatively nonspecific: they include headache, papilledema, vomiting,seizures, focal neurological deficits (motor or sensory) and impaired consciousness. CVT has long been considered as rare and mostly infection-related event; moreover, due to its nonspecific clinical manifestations, the diagnosis has been difficult, delayed and could often be made only post mortem.

  10. The Lyman alpha Reference Sample VI: Lyman alpha escape from the edge-on disk galaxy Mrk1486

    CERN Document Server

    Duval, Florent; Hayes, Matthew; Zackrisson, Erik; Verhamme, Anne; Orlitova, Ivana; Adamo, Angela; Guaita, Lucia; Melinder, Jens; Cannon, John M; Laursen, Peter; Rivera-Thorsen, Thoger; Herenz, E Christian; Gruyters, Pieter; Mas-Hesse, J Miguel; Kunth, Daniel; Sandberg, Andreas; Schaerer, Daniel; Mansson, Tore

    2015-01-01

    While numerical simulations suggest that the strength of the Lyman alpha (Lya) line of star-forming disk galaxies strongly depends on the inclination at which they are observed (i.e. from edge-on to face-on, we expect to see a change from an attenuated Lya line to a strong Lya emission line), recent observations with the Hubble space telescope (HST) have highlighted few low-redshift highly inclined (edge-on) disk galaxies that breaks this trend. We aim to understand how a strong Lya emission line is able to escape from one of those inclined disk galaxies, named Mrk1486 (z=0.0338). For that purpose we used a large set of HST imaging and spectroscopic data to investigate both the ISM structure and the dominant source of Lya radiation inside Mrk1486. Moreover, we used a 3D Monte Carlo Lya radiation transfer code to study the radiative transfer of Lya and UV continuum photons inside a 3D geometry of neutral hydrogen (HI) and dust that models the ISM structure at the galaxy center. The analysis of IFU Halpha spect...

  11. Variable Emissivity Through MEMS Technology

    Science.gov (United States)

    Darrin, Ann Garrison; Osiander, Robert; Champion, John; Swanson, Ted; Douglas, Donya; Grob, Lisa M.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    This paper discusses a new technology for variable emissivity (vari-e) radiator surfaces, which has significant advantages over traditional radiators and promises an alternative design technique for future spacecraft thermal control systems. All spacecraft rely on radiative surfaces to dissipate waste heat. These radiators have special coatings, typically with a low solar absorptivity and a high infrared-red emissivity, that are intended to optimize performance under the expected heat load and thermal sink environment. The dynamics of the heat loads and thermal environment make it a challenge to properly size the radiator and often require some means of regulating the heat rejection rate of the radiators in order to achieve proper thermal balance. Specialized thermal control coatings, which can passively or actively adjust their emissivity offer an attractive solution to these design challenges. Such systems would allow intelligent control of the rate of heat loss from a radiator in response to heat load and thermal environmental variations. Intelligent thermal control through variable emissivity systems is well suited for nano and pico spacecraft applications where large thermal fluctuations are expected due to the small thermal mass and limited electric resources. Presently there are three different types of vari-e technologies under development: Micro ElectroMechanical Systems (MEMS) louvers, Electrochromic devices, and Electrophoretic devices. This paper will describe several prototypes of micromachined (MEMS) louvers and experimental results for the emissivity variations measured on theses prototypes. It will further discuss possible actuation mechanisms and space reliability aspects for different designs. Finally, for comparison parametric evaluations of the thermal performances of the new vari-e technology and standard thermal control systems are presented in this paper.

  12. Emissions from decentralised CHP plants 2007 - Energinet.dk Environmental project no. 07/1882. Project report 5 - Emission factors and emission inventory for decentralised CHP production

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Thomsen, M.

    2010-06-15

    Updated emission factors for decentralised combined heat and power (CHP) plants with a capacity < 25MWe have been estimated based on project emission measurements as well as emission measurements performed in recent years that were collected. The emission factors valid for 2006/2007 have been estimated for the plant technologies: Municipal solid waste (MSW) incineration plants, plants combusting straw or wood, natural gas fuelled reciprocating engines, biogas fuelled engines, natural gas fuelled gas turbines, gas oil fuelled reciprocating engines, gas oil fuelled gas turbines, steam turbines combusting residual oil and reciprocating engines combusting biomass producer gas based on wood. The emission factors for MSW incineration plants are much lower than the emission factors that were estimated for year 2000. The considerable reduction in the emission factors is a result of lower emission limit values in Danish legislation since 2006 that has lead to installation of new and improved flue gas cleaning systems in most MSW incineration plants. For CHP plants combusting wood or straw no major technical improvements have been implemented. The emission factors for natural gas fuelled reciprocating engines have been reduced since year 2000 as a result of technical improvements that have been carried out due to lower emission limit values in Danish legislation. The NO{sub x} emission factor for natural gas fuelled gas turbines has decreased 62 % since year 2000. This is a result of installation of low-NO{sub x} burners in almost all gas turbines that has been necessary to meet new emission limits in Danish legislation. The emission measurements programme included screening of the emissions of HCB, PCB, PCDD/-F and PBDD/-F. Compared to the Danish national emission decentralized CHP plants are major emission sources for CH{sub 4}, NO{sub x}, SO{sub 2}, heavy metals and HCB. (author)

  13. Anomalous Microwave Emission

    CERN Document Server

    Kogut, A J

    1999-01-01

    Improved knowledge of diffuse Galactic emission is important to maximize the scientific return from scheduled CMB anisotropy missions. Cross-correlation of microwave maps with maps of the far-IR dust continuum show a ubiquitous microwave emission component whose spatial distribution is traced by far-IR dust emission. The spectral index of this emission, beta_{radio} = -2.2 (+0.5 -0.7) is suggestive of free-free emission but does not preclude other candidates. Comparison of H-alpha and microwave results show that both data sets have positive correlations with the far-IR dust emission. Microwave data, however, are consistently brighter than can be explained solely from free-free emission traced by H-alpha. This ``anomalous'' microwave emission can be explained as electric dipole radiation from small spinning dust grains. The anomalous component at 53 GHz is 2.5 times as bright as the free-free emission traced by H-alpha, providing an approximate normalization for models with significant spinning dust emission.

  14. Due Process Hearing Case Study

    Science.gov (United States)

    Bateman, David F.

    2009-01-01

    William is 9 years of age, residing with his parent within the boundaries of an unnamed district ("the District"). As a student with autism he is eligible for special education programming and services. There was one issue presented for this due process hearing: What was the appropriate program and placement for him for the 2008-2009 school year?…

  15. Elephantine nose due to rhinoentomophthoromycosis.

    Science.gov (United States)

    Ghorpade, Ashok; Sarma, Podila S A; Iqbal, Syed Md

    2006-01-01

    Rhinoentomophthoromycosis in an immunocompetent Indian male due to Basidiobolus species resulting in a huge (elephantine) nasal deformity, is reported. The diagnosis was done by demonstration of hyphae in direct tissue smear examination in potassium hydroxide, histopathological examination and by cultural characteristics. He showed an excellent response to oral potassium iodide solution.

  16. Endocarditis Due to Citrobacter Freundii

    OpenAIRE

    Reyes, Cesar V.; Folwarkiw, Oksana

    1984-01-01

    The etiologic association of acute bacterial endocarditis with the Citrobacter species has been rare, although it is one of the opportunistic organisms that afflicts the elderly, neonates, the debilitated and immunocompromised. We report a case of endocarditis due to Citrobacter freundii.

  17. Emission inventory of evaporative emissions of VOCs in four metro cities in India.

    Science.gov (United States)

    Srivastava, Anjali; née Som Majumdar, Dipanjali

    2010-01-01

    High concentrations of volatile organic compounds (VOCs) in ambient air of urban areas stress the need for the control of VOC emissions due to the toxic and carcinogenic nature of many VOCs commonly encountered in urban air. Emission inventories are an essential tool in the management of local air quality, which provide a listing of sources of air pollutant emissions within a specific area over a specified period of time. This study intended to provide a level IV emission inventory as par the United States Environmental Protection Agency (USEPA) definition for evaporative VOC emissions in the metro cities of India namely Delhi, Mumbai, Chennai, and Kolkata. The vehicular evaporative emissions are found to be the largest contributor to the total evaporative emissions of hydrocarbons followed by evaporative losses related to petrol loading and unloading activities. Besides vehicle-related activities, other major sources contributing to evaporative emissions of hydrocarbons are surface coating, dry cleaning, graphical art applications, printing (newspaper and computer), and the use of consumer products. Various specific preventive measures are also recommended for reducing the emissions.

  18. Cryptic Methane Emissions from Upland Forest Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Megonigal, Patrick [Smithsonian Institution, Washington, DC (United States); Pitz, Scott [Johns Hopkins Univ., Baltimore, MD (United States); Smithsonian Institution, Washington, DC (United States)

    2016-04-19

    This exploratory research on Cryptic Methane Emissions from Upland Forest Ecosystems was motivated by evidence that upland ecosystems emit 36% as much methane to the atmosphere as global wetlands, yet we knew almost nothing about this source. The long-term objective was to refine Earth system models by quantifying methane emissions from upland forests, and elucidate the biogeochemical processes that govern upland methane emissions. The immediate objectives of the grant were to: (i) test the emerging paradigm that upland trees unexpectedly transpire methane, (ii) test the basic biogeochemical assumptions of an existing global model of upland methane emissions, and (iii) develop the suite of biogeochemical approaches that will be needed to advance research on upland methane emissions. We instrumented a temperate forest system in order to explore the processes that govern upland methane emissions. We demonstrated that methane is emitted from the stems of dominant tree species in temperate upland forests. Tree emissions occurred throughout the growing season, while soils adjacent to the trees consumed methane simultaneously, challenging the concept that forests are uniform sinks of methane. High frequency measurements revealed diurnal cycling in the rate of methane emissions, pointing to soils as the methane source and transpiration as the most likely pathway for methane transport. We propose the forests are smaller methane sinks than previously estimated due to stem emissions. Stem emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration, resolving differences between models and measurements. The methods we used can be effectively implemented in order to determine if the phenomenon is widespread.

  19. Carbon emissions Inventory Games

    OpenAIRE

    Al-Emadi, Eiman Ali

    2016-01-01

    Carbon emissions reduction has been the center of attention in many organizations during the past few decades. Many international entities developed rules and regulations to monitor and control carbon emissions especially under supply chain context. Furthermore, researchers investigated techniques and methods on how reduce carbon emissions under operational adjustment which can be done by cooperation or coordination. The main contribution of this thesis is to measure to what extend cooperatio...

  20. 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

  1. 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

  2. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, M.; Illerup, J. B.

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOX, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins and PAH. Since 1990 the fuel consumption...... in stationary combustion has increased by 14% - the fossil fuel consumption however only by 8%. Despite the increased fuel consumption the emission of several pollutants has decreased due to the improved flue gas cleaning technology, improved burner technology and the change of fuel type used. A considerable...... plants. The emission of PAH increased as a result of the increased combustion of wood in residential boilers and stoves. Uncertainties for the emissions and trends have been estimated...

  3. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, M.; Illerup, J. B.

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are: SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins and PAH. Since 1990 the fuel consumption...... in stationary combustion has increased by 12% - the fossil fuel consumption however only by 6%. Despite the increased fuel consumption the emission of several pollutants have decreased due to the improved flue gas cleaning technology, improved burner technology and the change of fuel type used. A considerable...... plants. The emission of PAH increased as a result of the increased combustion of wood in residential boilers and stoves. Uncertainties for the emissions and trends have been estimated....

  4. Managing Refrigerant Emissions

    Science.gov (United States)

    Access information on EPA's efforts to address ozone layer depletion by reducing emissions of refrigerants from stationary refrigeration and air conditioning systems and motor vehicle air conditioning systems.

  5. VOC emissions chambers

    Data.gov (United States)

    Federal Laboratory Consortium — In order to support the development of test methods and reference materials for volatile organic compounds (VOC) emissions from building materials and furnishings,...

  6. Microgravity Emissions Laboratory (MEL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Microgravity Emissions Laboratory (MEL) utilizes a low-frequency acceleration measurement system for the characterization of rigid body inertial forces generated...

  7. Toluene emissions from plants

    Science.gov (United States)

    Heiden, A. C.; Kobel, K.; Komenda, M.; Koppmann, R.; Shao, M.; Wildt, J.

    The emission of toluene from different plants was observed in continuously stirred tank reactors and in field measurements. For plants growing without stress, emission rates were low and ranged from the detection limit up to 2·10-16 mol·cm-2·s-1. Under conditions of stress, the emission rates exceeded 10-14 mol·cm-2·s-1. Exposure of sunflower (Helianthus annuus L. cv. Gigantheus) to 13CO2 resulted in 13C-labeling of the emitted toluene on a time scale of hours. Although no biochemical pathway for the production of toluene is known, these results indicate that toluene is synthesized by the plants. The emission rates of toluene from sunflower are dependent on nutrient supply and wounding. Since α-pinene emission rates are also influenced by these factors, toluene and α-pinene emissions show a high correlation. During pathogen attack on Scots pines (Pinus sylvestris L.) significant toluene emissions were observed. In this case emissions of toluene and α-pinene also show a good correlation. Toluene emissions were also found in field experiments with pines using branch enclosures.

  8. Wage differentials due to gender.

    Science.gov (United States)

    Smith, N; Westergard-nielsen, N

    1988-10-01

    "In this paper, a longitudinal data set covering 5% of all Danish wage earners over a 9-year period is used to shed light on the observed wage differentials due to gender. A human capital model is used to isolate the effects of changes in experience, schooling and unemployment, together with other factors.... Despite the observation from macro statistics that women have had the highest observed increases in wage rates, the models show that this increase is mainly due to an improvement in their background characteristics and that men still receive a higher return to their characteristics. The main difference between genders appears to be that female workers do not, in general, get any return to their experience. The estimates also show negative effects on the wage rate of previous spells of unemployment." excerpt

  9. Maternal mortality due to trauma.

    Science.gov (United States)

    Romero, Vivian Carolina; Pearlman, Mark

    2012-02-01

    Maternal mortality is an important indicator of adequacy of health care in our society. Improvements in the obstetric care system as well as advances in technology have contributed to reduction in maternal mortality rates. Trauma complicates up to 7% of all pregnancies and has emerged as the leading cause of maternal mortality, becoming a significant concern for the public health system. Maternal mortality secondary to trauma can often be prevented by coordinated medical care, but it is essential that caregivers recognize the unique situation of providing simultaneous care to 2 patients who have a complex physiologic relationship. Optimal management of the pregnant trauma victim requires a multidisciplinary team, where the obstetrician plays a central role. This review focuses on the incidence of maternal mortality due to trauma, the mechanisms involved in traumatic injury, the important anatomic and physiologic changes that may predispose to mortality due to trauma, and finally, preventive strategies that may decrease the incidence of traumatic maternal death.

  10. Visual Impairment Due to Lissencephaly

    OpenAIRE

    Marqués-Fernández, V. E.; Sánchez-Tocino, H.; Escudero-Caro, M.T.; Cancho-Candela, R.; García-Zamora, M.

    2016-01-01

    Lissencephaly is a rare disorder due to abnormal neural migration, causing neurological impairment and clinically characterised by mental retardation and epilepsy. Any disturbance of the visual pathway can cause loss of vision. The authors describe a case of a 6-year-old boy referred to the ophthalmologist presenting poor bilateral vision. This child had no other known medical conditions, and neurological examination was completely normal. Only when a magnetic resonance imaging was made that ...

  11. Autoerotic death due to electrocution

    Directory of Open Access Journals (Sweden)

    Piotr Arkuszewski

    2014-08-01

    Full Text Available Autoerotic death is a very rare case in forensic medicine. It is usually caused by asphyxia, but other reasons are also possible. Herein we present a case of autoerotic death due to electrocution caused by a self-made electrical device. The device was constructed to increase sexual feelings through stimulation of the scrotal area.

  12. Laboratory estimation of black carbon emissions from cookstoves

    OpenAIRE

    Sota, Candela de la; Kane, M.; M. Viana; Lumbreras Martin, Julio; Ba, M.B.; Querol, Xavier; Mazorra, J.; Narros Sierra, Adolfo; Borge, R.; Youm, I.

    2016-01-01

    Recent estimations show that residential solid fuel combustion accounts for 25% of global black carbon (BC) emissions (Lamarque et al., 2010). Thus, the control of these emissions through the implementation of cleaner cooking technologies could be crucial for climate change mitigation (Venkataraman et al., 2005). However, BC emission factors for biofuel cooking stoves have been poorly estimated due to the wide distribution and remote location of the stoves and the relatively complex existing ...

  13. Methods for measuring and estimating methane emission from ruminants

    OpenAIRE

    2012-01-01

    Simple Summary Knowledge about methods used in quantification of greenhouse gasses is currently needed due to international commitments to reduce the emissions. In the agricultural sector one important task is to reduce enteric methane emissions from ruminants. Different methods for quantifying these emissions are presently being used and others are under development, all with different conditions for application. For scientist and other persons working with the topic it is very important to ...

  14. Outsourcing CO2 Emissions

    Science.gov (United States)

    Davis, S. J.; Caldeira, K. G.

    2009-12-01

    CO2 emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO2 directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with consumption of goods and services in each country. This consumption-based emissions inventory differs from the production-based inventory because of imports and exports of goods and services that, either directly or indirectly, involved CO2 emissions. Using the latest available data and reasonable assumptions regarding trans-shipment of embodied carbon through third-party countries, we developed a global consumption-based CO2 emissions inventory and have calculated associated consumption-based energy and carbon intensities. We find that, in 2004, 24% of CO2 emissions are effectively outsourced to other countries, with much of the developed world outsourcing CO2 emissions to emerging markets, principally China. Some wealthy countries, including Switzerland and Sweden, outsource over half of their consumption-based emissions, with many northern Europeans outsourcing more than three tons of emissions per person per year. The United States is both a big importer and exporter of emissions embodied in trade, outsourcing >2.6 tons of CO2 per person and at the same time as >2.0 tons of CO2 per person are outsourced to the United States. These large flows indicate that CO2 emissions embodied in trade must be taken into consideration when considering responsibility for increasing atmospheric greenhouse gas concentrations.

  15. Trace element emissions from coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

    Trace elements are emitted during coal combustion. The quantity, in general, depends on the physical and chemical properties of the element itself, the concentration of the element in the coal, the combustion conditions and the type of particulate control device used, and its collection efficiency as a function of particle size. Some trace elements become concentrated in certain particle streams following combustion such as bottom ash, fly ash, and flue gas particulate matter, while others do not. Various classification schemes have been developed to describe this partitioning behaviour. These classification schemes generally distinguish between: Class 1: elements that are approximately equally concentrated in the fly ash and bottom ash, or show little or no fine particle enrichment, examples include Mn, Be, Co and Cr; Class 2: elements that are enriched in the fly ash relative to bottom ash, or show increasing enrichment with decreasing particle size, examples include As, Cd, Pb and Sb; Class 3: elements which are emitted in the gas phase (primarily Hg (not discussed in this review), and in some cases, Se). Control of class 1 trace elements is directly related to control of total particulate matter emissions, while control of the class 2 elements depends on collection of fine particulates. Due to the variability in particulate control device efficiencies, emission rates of these elements can vary substantially. The volatility of class 3 elements means that particulate controls have only a limited impact on the emissions of these elements.

  16. Danish emission inventories for stationary combustion plants. Inventories until 2008

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, M.; Hjelgaard, K.

    2010-10-15

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO{sub 2}, NO{sub x}, NMVOC, CH{sub 4}, CO, CO{sub 2}, N{sub 2}O, NH{sub 3}, particulate matter, heavy metals, dioxins, HCB and PAH. The CO{sub 2} emission in 2008 was 16 % lower than in 1990. However, fluctuations in the emission level are large as a result of electricity import/export. The emission of CH{sub 4} has increased due to increased use of lean-burn gas engines in combined heating and power (CHP) plants. However, the emission has decreased in recent years due to structural changes in the Danish electricity market. The N{sub 2}O emission was higher in 2008 than in 1990 but the fluctuations in the time-series are significant. A considerable decrease of the SO{sub 2}, NO{sub x} and heavy metal emissions is mainly a result of decreased emissions from large power plants and waste incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants. (Author)

  17. The atmospheric emissions in Spain: a regional analysis

    Energy Technology Data Exchange (ETDEWEB)

    Guntin-Araujo, X.; Chas-Amil, M.L. [Universidade de Santiago de Compostela, Dept. de Metodos Cuantitativos par a Economia, Santiago de Compostela (Spain); Lorenzo-Diaz, M.C. Universidade de Santiago de Compostela, Dept. de Economia Aplicada, Santiago de Compostela (ES))

    1999-07-01

    The gas emission towards the atmosphere are one of the main and most actual environmental problems in the world. The effects of greenhouse gas emission have been studied and treated recently in the Climate Change Conference in Kyoto. In the approved Kyoto Protocol, the European Union will reduce emissions by 8 per cent, the USA by 7 per cent, and Japan by 6 per cent. The data for each country are used to implement policies and make global decisions regarding the level of emissions allowed in the future. For this reason, a study more in depth about the origin and level of emissions from a regional perspective becomes necessary, due to the implications on regional development. The study provides detailed information regarding atmospheric emissions in Spanish regions. Shows that in many cases the atmospheric emissions are not directly related to the economic situations of each region. For this reason, environmental policies should pay attention to the regional differences within a country. (Author)

  18. The contribution of aircraft emissions to the atmospheric sulfur budget

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, E. [Stockholm Univ. (Sweden). Dept. of Meteorology; Feichter, J. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Sausen, R.; Hein, R. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1998-01-01

    An atmospheric general circulation model including the atmospheric sulfur cycle has been used to investigate the impact of aircraft sulfur emissions on the global sulfur budget of the atmosphere. The relative contribution from aircraft sulfur to the atmospheric sulfate burden is larger than the ratio between aircraft emissions and surface emissions due to the calculated long turn-over time of aircraft sulfate (about 12 days). However, in terms of the sulfate mass balance, aircraft emissions are small, contributing about 1% of the total sulfate mass north of 40 deg C where the aircraft emissions are largest. Despite this small contribution to sulfate mass, the aircraft emissions could potentially significantly enhance the background number concentration of aerosol particles. Based on the model calculations the increased stratospheric background aerosol mass observed during the last decades can not be explained by increased aircraft sulfur emissions 50 refs, 9 figs, 4 tabs

  19. Episodical CO2 emission during shoulder seasons in the arctic

    DEFF Research Database (Denmark)

    Friborg, Thomas; Elberling, Bo; Hansen, Birger

    Carbon cycling and trace gas emissions from high latitude ecosystems has over the last decade received increasing attention due to the dramatic climate change experienced and predicted by GCM scenarios for the region, and the effect that such changes may have on the carbon stored in the arctic...... of CO2 during spring. The other example, from a study during late autumn and winter from high arctic Svalbard we found that episodical emissions of CO2 accounted for a significant part of the total CO2 emission form the site. The emission pattern could be associated with temperature variations...... at the site and show high emission rates the freeze-in periods, whereas shorter periods with temperatures above freezing point resulted in lower emission rates. In We interpret this as emission of CO2 is being decoupled from the biological production during the freeze-in period and is primarily linked...

  20. Chemical chacterization of biofuel exhaust emissions

    NARCIS (Netherlands)

    Jedynska, A.D.; Tromp, P.C.; Houtzager, M.M.G.; Kooter, I.M.

    2015-01-01

    Use of biodiesel is increasing following implementation of various policy instruments and a surge in demand due to growing urbanized populations. A series of experiments to characterize the chemical composition of emissions generated during combustion of petro-diesel (B0), biodiesel blends (B5, B10,

  1. Air Emission Inventory for the INEEL -- 1999 Emission Report

    Energy Technology Data Exchange (ETDEWEB)

    Zohner, Steven K

    2000-05-01

    This report presents the 1999 calendar year update of the Air Emission Inventory for the Idaho National Engineering and Environmental Laboratory (INEEL). The INEEL Air Emission Inventory documents sources and emissions of nonradionuclide pollutants from operations at the INEEL. The report describes the emission inventory process and all of the sources at the INEEL, and provides nonradionuclide emissions estimates for stationary sources.

  2. Anaphylaxis Due to Head Injury

    Directory of Open Access Journals (Sweden)

    Bruner, Heather C.

    2015-05-01

    Full Text Available Both anaphylaxis and head injury are often seen in the emergency department, but they are rarely seen in combination. We present a case of a 30-year-old woman who presented with anaphylaxis with urticaria and angioedema following a minor head injury. The patient responded well to intramuscular epinephrine without further complications or airway compromise. Prior case reports have reported angioedema from hereditary angioedema during dental procedures and maxillofacial surgery, but there have not been any cases of first-time angioedema or anaphylaxis due to head injury. [West J Emerg Med. 2015;16(3:435–437.

  3. Endocarditis due to Kingella kingae.

    Science.gov (United States)

    Odum, L; Jensen, K T; Slotsbjerg, T D

    1984-06-01

    Four cases of endocarditis due to Kingella kingae are described in compromised patients. All had primary heart disease, and two had systemic lupus erythematosis and congenital heart defect respectively, in addition. Confirmation of Kingella kingae was made in one case at autopsy. The literature on 11 cases of endocarditis, 2 bacteremia, 4 osteomyelitis, 5 septic arthritis and 1 intervertebral disc infection, all caused by Kingella kingae, is reviewed. Our findings confirm that the organism is of low pathogenicity. Children may be predisposed to infection with Kingella kingae.

  4. Interference due to coherence swapping

    Indian Academy of Sciences (India)

    Arun Kumar Pati; Marek Zukowski

    2001-02-01

    We propose a method called ‘coherence swapping’ which enables us to create superposition of a particle in two distinct paths, which is fed with initially incoherent, independent radiation. This phenomenon is also present for the charged particles, and can be used to swap the effect of flux line due to the Aharonov–Bohm effect. We propose an optical version of experimental set-up to test the coherence swapping. The phenomenon, which is simpler than entanglement swapping or teleportation, raises some fundamental questions about the true nature of wave-particle duality, and also opens up the possibility of studying the quantum erasure from a new angle.

  5. Tardive akathisia due to sulpiride.

    Science.gov (United States)

    López de Munain, A; Poza, J J; Gorospe, A; Arce, A; Martí Massó, J F

    1994-10-01

    A 56 year-old woman who suffered from parkinsonism, oro-lingual dyskinesia (OLD) and tardive akathisia (TA) due to sulpiride is reported. OLD and TA appeared after sulpiride withdrawal. The patient was successfully treated with tetrabenazine even a mild parkinsonism was present. TA seems to be related with an apparent dopaminergic hyperactivity and it has to be differentiated of other neuroleptic-induced movement disorders such as restless legs syndrome in order of an appropriate treatment. Sulpiride has the same possible side effects than classic neuroleptics.

  6. Maculopathy due to drug inhalation.

    Science.gov (United States)

    Asensio-Sánchez, V M; Gonzalez-Buendia, L; Marcos-Fernández, M

    2014-08-01

    A case of maculopathy due to "poppers" is described. Poppers is a drug composed of various forms of alkyl nitrite. A 39 year-old man, who had been using poppers for years, was seen in the clinic with phosphenes, reduced visual acuity and central scotoma. The SD-OCT in the right eye showed disruption at the level of the IS/OS junction line. The SD-OCT scan in the left eye showed an outer rectangular retinal hole and an outer retinal cyst. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  7. Total hemispherical emissivity of Inconel 718

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Benjamin P.; Nelson, Shawn E.; Walton, Kyle L.; Ghosh, Tushar K.; Tompson, Robert V.; Loyalka, Sudarshan K., E-mail: LoyalkaS@missouri.edu

    2015-06-15

    in the emissivity whereas the coating of graphite powder onto the 220 grit sandblasted Inconel 718 did show an increase in emissivity up to the range from 0.60 at 650 K to 0.70 at 1200 K. This was apparently due to better adhesion of graphite on the roughened surface.

  8. 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.

  9. Uncertainties in emission inventories

    NARCIS (Netherlands)

    Aardenne, van J.A.

    2002-01-01

    Emission inventories provide information about the amount of a pollutant that is emitted to the atmosphere as a result of a specific anthropogenic or natural process at a given time or place. Emission inventories can be used for either policy or scientific purposes. For policy purpose

  10. Optical Antenna Enhanced Spontaneous Emission in Semiconductors

    Science.gov (United States)

    Messer, Kevin James

    Optical antennas can be used to dramatically increase the rate that semiconductors spontaneously emit photons. While traditional LEDs are limited in bandwidth due to the "slow" rate of spontaneous emission, antenna-enhanced LEDs have the potential to be a fast, efficient, nanoscale light emitter. Traditionally, lasers have dominated LEDs as the emitter in optical interconnects due to a 200x speed advantage of stimulated emission over spontaneous emission. This paradigm may be reversed by coupling LEDs to optical antennas. In fact, antenna enhanced spontaneous emission can be faster than the fastest stimulated emission. Spontaneous emission originates from dipole fluctuations within the emitting material. The size of these fluctuations is much less than the wavelength of light emission, which leads to slow spontaneous emission. Coupling the material to an optical antenna corrects the size mismatch and improves the rate of radiation. An optical antenna circuit model is developed to predict the degree to which spontaneous emission can be enhanced. The circuit model presented in this dissertation shows that enhancement over 1000x is possible while still maintaining greater than 50% efficiency. The circuit model provides insight how to design optical antennas for coupling to dipole sources, for maximum enhancement, and for high efficiency. A method for incorporating the anomalous skin effect, often overlooked in metal optics, is provided. While FDTD/FEM simulations cannot include this effect due to its nonlocal nature, its impact can be examined through the use of the optical antenna circuit model. Analysis of the tradeoff between achieving large spontaneous emission enhancement and maintaining high efficiency leads to an ideal antenna feedgap size of 10nm. Experimental demonstration of spontaneous emission enhancement from InP coupled to an arch-dipole antenna is presented. Photoluminescence measurements show light emission from antenna-coupled InP over bare InP ridges

  11. Electric Current Induced Light Emission from C60

    NARCIS (Netherlands)

    Palstra, T.T.M.; Haddon, R.C.; Lyons, K.B.

    1997-01-01

    We report the luminescence of C60 crystals and films due to the passage of an electrical current. The current-voltage behavior is highly non-linear with light-emission beyond a threshold voltage. The emission spectrum is featureless and resembles black-body radiation with an effective temperature on

  12. Future aerosol emissions: a multi-model comparison

    NARCIS (Netherlands)

    Smith, Steven J.; Rao, Shilpa; Riahi, Keywan; van Vuuren, Detlef P.; Calvin, Katherine V.; Kyle, Page

    2016-01-01

    This paper compares projections over the twenty-first century of SO2, BC, and OC emissions from three technologically detailed, long-term integrated assessment models. The character of the projections and the response of emissions due to a comprehensive climate policy are discussed focusing on the

  13. Unidirectional light emission from low-index polymer microlasers

    Energy Technology Data Exchange (ETDEWEB)

    Schermer, M.; Wiersig, J., E-mail: jan.wiersig@ovgu.de [Institut für Theoretische Physik, Otto-von-Guericke-Universität Magdeburg, Postfach 4120, D-39016 Magdeburg (Germany); Bittner, S.; Singh, G.; Lebental, M., E-mail: lebental@lpqm.ens-cachan.fr [Laboratoire de Photonique Quantique et Moléculaire, CNRS UMR 8537, Institut d' Alembert FR 3242, École Normale Supérieure de Cachan, 61 Avenue du Président Wilson, F-94235 Cachan (France); Ulysse, C. [Laboratoire de Photonique et Nanostructures, CNRS UPR20, Route de Nozay, F-91460 Marcoussis (France)

    2015-03-09

    We report on experiments with deformed polymer microlasers that have a low refractive index and exhibit unidirectional light emission. We demonstrate that the highly directional emission is due to transport of light rays along the unstable manifold of the chaotic saddle in phase space. Experiments, ray-tracing simulations, and mode calculations show very good agreement.

  14. Infra-red reflectance and emissivity spectra of nanodiamonds

    OpenAIRE

    MATURILLI, A.; A. A Shiryaev; Kulakova, I I; Helbert, J.

    2012-01-01

    Reflectance and emissivity spectra of nanodiamonds powder were measured in a dedicated setup at temperatures up to 873 K. The spectra are characterised by presence of sharp bands due to surface-bound functional groups. Thermal desorption of oxygen-containing groups lead to corresponding spectral changes. The maximal emissivity of nanodiamond powder reaches 0.985.

  15. Unidirectional light emission from low-index polymer microlasers

    CERN Document Server

    Schermer, M; Singh, G; Ulysse, C; Lebental, M; Wiersig, J

    2014-01-01

    We report on experiments with deformed polymer microlasers that have a low refractive index and exhibit unidirectional light emission. We demonstrate that the highly directional emission is due to transport of light rays along the unstable manifold of the chaotic saddle in phase space. Experiments, ray-tracing simulations, and mode calculations show very good agreement.

  16. Improving material management to reduce greenhouse gas emissions

    NARCIS (Netherlands)

    Hekkert, Marko Peter

    2001-01-01

    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 methan

  17. A Cluster of Low-Redshift Lyman-$\\alpha$ Clouds toward PKS 2155-304; 1, Limits on Metals and D/H

    CERN Document Server

    Shull, J M; Stocke, J T; Giroux, M L; Van Gorkom, J H; Lee, Y H; Carilli, C L; Penton, Steven V.; Stocke, John T.; Giroux, Mark L.; Lee, Yong-Han; Carilli, Chris

    1998-01-01

    We report observations from the Hubble Space Telescope (HST) and the VLA on the galactic environment, metallicity, and D/H in strong low-redshift Lya absorption systems toward the bright BL Lac object PKS 2155-304. GHRS/G160M spectra at 20 km/s resolution show 14 Lya absorbers, 6 clustered at cz = 16,100-18,500 km/s. ORFEUS claimed LyC absorption at z = 0.056 with N(HI) = (2-5)x10^16 cm^-2, while our Lya data suggest N(HI) = (3-10)x10^14 cm^-2. Higher columns are possible if the Lya line core at 17,000 +/- 50 km/s contains narrow HI components. We identify the Lya cluster with a group of five HI galaxies offset by 400-800 kpc from the sightline. The two strongest absorption features cover the same velocity range as the HI emission in the two galaxies closest to the line of sight. If the Lya is associated with these galaxies, they must have huge halos of highly turbulent, mostly ionized gas. The Lya absorption could also arise from an extended sheet of intragroup gas, or from smaller primordial clouds and halo...

  18. The emission of atoms and molecules accompanying fracture of single-crystal MgO

    Science.gov (United States)

    Dickinson, J. T.; Jensen, L. C.; Mckay, M. R.; Freund, F.

    1986-01-01

    The emission of particles due to deformation and fracture of materials has been investigated. The emission of electrons (exoelectron emission), ions, neutral species, photons (triboluminescence), as well as long wavelength electromagnetic radiation was observed; collectively these emissions are referred to as fractoemission. This paper describes measurements of the neutral emission accompanying the fracture of single-crystal MgO. Masses detected are tentatively assigned to the emission of H2, CH4, H2O, CO, O2, CO2, and atomic Mg. Other hydrocarbons are also observed. The time dependencies of some of these emissions relative to fracture are presented for two different loading conditions.

  19. Emission factors of the iron and steel sector for the emission reporting; Emissionsfaktoren zur Eisen- und Stahlindustrie fuer die Emissionsberichterstattung

    Energy Technology Data Exchange (ETDEWEB)

    Hensmann, Michael; Haardt, Sebastian; Ebert, Dominik [Betriebsforschungsinstitut VDEh-Institut fuer Angewandte Forschung GmbH, Duesseldorf (Germany)

    2012-10-15

    The German Umweltbundesamt (UBA) records emission factors of important groups of emitters of the iron- and steelmaking industry in a central database named ''Zentrales System Emissionen'' (ZSE) since 1990. This data is being used for calculations of emission inventories. The main purposes are the generation of forecasts, calculating emissions of other plants and the appraisal of potential measures for reduction of pollution. This makes it possible to identify and appraise future problems and measures. Because of steadily increasing requirements to data quality and quality assurance, it became necessary to update the ZSE with characteristical emission data in order to give a representative view of relevant stages in the iron- and steelmaking industry with respect to emissions. In 2008, the VDEh-Betriebsforschungsinstitut (BFI) was assigned to determine up-to-date emission factors for the following relevant stages in the iron- and steelmaking industry: - sintering plant - coking plant - blast furnace - steel making (differentiated between oxygen and electric steel making) - production of rolled steel Due to a wide diversity of data quality, a consecutive project to determine the corresponding uncertainty of the emission factors was integrated into the ongoing project. This is necessary to create reliable forecasts of emissions and to meet national and international duties of reporting. The project was supported by 18 companies of the German iron- and steelmaking industry. A total of 40 relevant sources of emissions were identified within the five stages of steelmaking and taken into consideration. The emission data for documenting organic and inorganic components of harmful gas, heavy metals and air borne dusts in the ZSE was taken from the reports of emissions 2008 of the supporting companies and made up for a total of 63 plants. Due to a wide variety of data quality the emissions of point sources and diffuse sources are treated separately. While

  20. Identifying and characterizing major emission point sources as a basis for geospatial distribution of mercury emissions inventories

    NARCIS (Netherlands)

    Steenhuisen, Frits

    2015-01-01

    Mercury is a global pollutant that poses threats to ecosystem and human health. Due to its global transport, mercury contamination is found in regions of the Earth that are remote from major emissions areas, including the Polar regions. Global anthropogenic emission inventories identify important se

  1. India Co2 Emissions

    Science.gov (United States)

    Sharan, S.; Diffenbaugh, N. S.

    2010-12-01

    Is there a way to find a balance between improving living conditions for the people on the margins and also reducing emissions while limiting our negative impacts on the climate? This is a critical question today because there are many arguments between developed and developing countries about who is responsible for global warming. Developed countries believe that it is the poor countries because they are not educated enough to know about how they are affecting the climate. While the developing countries hold wealthy nations responsible because they are using the most resources. However it is important to acknowledge the fact that if there was no gap in between the developed and developing countries our emissions total would be much higher. This “gap” has been a natural controlling factor in climate change. This is why I wanted to see if I could plot what it would look like if a developing country such as India were to produce emissions that the US or Switzerland or Norway are producing as developed countries. India has a population total of 1.1 billion compared to the US with only 298 million, Switzerland with 7.5 million, and Norway with 4.6 million people. When the population is compared to the emissions output in metric tons, per capita, India produced the least emissions out of these countries, 1.4 tons per person while having the second largest population in the world, while the US produced 19 tons per capita, Switzerland produced 5.6 and Norway produced 8.7 tons per capita in 2006. The emissions rate is growing every year and increases widely and globally. If India was producing emissions that equal Norway, Switzerland and the US the total emissions it would be producing annually would be 9 billion for Norway, 6 billion for Switzerland and 20 billion emissions for the US, all in the year 2006 alone. This shows how the balance between countries with huge populations and very little emission output and average population and high emission out put has

  2. Occupational injuries due to violence.

    Science.gov (United States)

    Hales, T; Seligman, P J; Newman, S C; Timbrook, C L

    1988-06-01

    Each year in the United States, an estimated 800 to 1,400 people are murdered at work, and an unknown number of nonfatal injuries due to workplace violence occur. Based on Ohio's workers' compensation claims from 1983 through 1985, police officers, gasoline service station employees, employees of the real estate industry, and hotel/motel employees were found to be at the highest risk for occupational violent crime (OVC) injury and death. Grocery store employees, specifically those working in convenience food stores, and employees of the real estate industry had the most reported rapes. Four previously unidentified industries at increased risk of employee victimization were described. Identification of industries and occupations at high risk for crime victimization provides the opportunity to focus preventive strategies to promote employee safety and security in the workplace.

  3. Collisional Aggregation due to Turbulence

    CERN Document Server

    Pumir, Alain

    2015-01-01

    Collisions between particles suspended in a fluid play an important role in many physical processes. As an example, collisions of microscopic water droplets in clouds are a necessary step in the production of macroscopic raindrops. Collisions of dust grains are also conjectured to be important for planet formation in the gas surrounding young stars, and also to play a role in the dynamics of sand storms. In these processes, collisions are favoured by fast turbulent motions. Here we review recent advances in the understanding of collisional aggregation due to turbulence. We discuss the role of fractal clustering of particles, and caustic singularities of their velocities. We also discuss limitations of the Smoluchowski equation for modelling these processes. These advances lead to a semi-quantitative understanding on the influence of turbulence on collision rates, and point to deficiencies in the current understanding of rainfall and planet formation.

  4. Emissions of greenhouse gases in the United States 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This is the fourth Energy Information Administration (EIA) annual report on US emissions of greenhouse gases. This report presents estimates of US anthropogenic (human-caused) emissions of carbon dioxide, methane, nitrous oxide, and several other greenhouse gases for 1988 through 1994. Estimates of 1995 carbon dioxide, nitrous oxide, and halocarbon emissions are also provided, although complete 1995 estimates for methane are not yet available. Emissions of carbon dioxide increased by 1.9% from 1993 to 1994 and by an additional 0.8% from 1994 to 1995. Most carbon dioxide emissions are caused by the burning of fossil fuels for energy consumption, which is strongly related to economic growth, energy prices, and weather. The US economy grew rapidly in 1994 and slowed in 1995. Estimated emissions of methane increased slightly in 1994, as a result of a rise in emissions from energy and agricultural sources. Estimated nitrous oxide emissions increased by 1.8% in 1995, primarily due to increased use of nitrogen fertilizers and higher output of chemicals linked to nitrous oxide emissions. Estimated emissions of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), which are known to contribute to global warming, increased by nearly 11% in 1995, primarily as a result of increasing substitution for chlorofluorocarbons (CFCs). With the exception of methane, the historical emissions estimates presented in this report are only slightly revised from those in last year`s report.

  5. Methane emissions in India: Sub-regional and sectoral trends

    Science.gov (United States)

    Garg, Amit; Kankal, Bhushan; Shukla, P. R.

    2011-09-01

    This paper uses the 2006 IPCC Guidelines and latest country specific emission factors to estimate Indian methane emissions at sectoral and district level for the years 1990, 1995, 2005 and 2008. The estimates show that while methane emissions have increased steadily over past two decades, their share in India's aggregate GHG emissions has declined from 31% in 1985 to 27% in 2008 mainly due to relatively higher growth CO 2 emissions from the fossil fuels. The estimates for the year 2008 show that: i) agriculture sector, which employed two-thirds of India's population and contributed 17% of GDP, accounted for 23% of India's GHG emissions ii) 83% of country's methane emissions are contributed by enteric fermentation, manure use and rice production, and iii) methane emissions from urban solid waste are steadily rising over the past two decades; their share in aggregate methane emissions has reached 8%. Resting on the disaggregated emissions estimates, the paper argues for using geographical and sectoral flexibilities to develop a roadmap for mitigation of methane emissions for India.

  6. Emissions of carbon tetrachloride from Europe

    Science.gov (United States)

    Graziosi, Francesco; Arduini, Jgor; Bonasoni, Paolo; Furlani, Francesco; Giostra, Umberto; Manning, Alistair J.; McCulloch, Archie; O'Doherty, Simon; Simmonds, Peter G.; Reimann, Stefan; Vollmer, Martin K.; Maione, Michela

    2016-10-01

    Carbon tetrachloride (CCl4) is a long-lived radiatively active compound with the ability to destroy stratospheric ozone. Due to its inclusion in the Montreal Protocol on Substances that Deplete the Ozone Layer (MP), the last two decades have seen a sharp decrease in its large-scale emissive use with a consequent decline in its atmospheric mole fractions. However, the MP restrictions do not apply to the use of carbon tetrachloride as feedstock for the production of other chemicals, implying the risk of fugitive emissions from the industry sector. The occurrence of such unintended emissions is suggested by a significant discrepancy between global emissions as derived from reported production and feedstock usage (bottom-up emissions), and those based on atmospheric observations (top-down emissions). In order to better constrain the atmospheric budget of carbon tetrachloride, several studies based on a combination of atmospheric observations and inverse modelling have been conducted in recent years in various regions of the world. This study is focused on the European scale and based on long-term high-frequency observations at three European sites, combined with a Bayesian inversion methodology. We estimated that average European emissions for 2006-2014 were 2.2 (± 0.8) Gg yr-1, with an average decreasing trend of 6.9 % per year. Our analysis identified France as the main source of emissions over the whole study period, with an average contribution to total European emissions of approximately 26 %. The inversion was also able to allow the localisation of emission "hot spots" in the domain, with major source areas in southern France, central England (UK) and Benelux (Belgium, the Netherlands, Luxembourg), where most industrial-scale production of basic organic chemicals is located. According to our results, European emissions correspond, on average, to 4.0 % of global emissions for 2006-2012. Together with other regional studies, our results allow a better constraint

  7. Global methane emissions from pit latrines.

    Science.gov (United States)

    Reid, Matthew C; Guan, Kaiyu; Wagner, Fabian; Mauzerall, Denise L

    2014-01-01

    Pit latrines are an important form of decentralized wastewater management, providing hygienic and low-cost sanitation for approximately one-quarter of the global population. Latrines are also major sources of the greenhouse gas methane (CH4) from the anaerobic decomposition of organic matter in pits. In this study, we develop a spatially explicit approach to account for local hydrological control over the anaerobic condition of latrines and use this analysis to derive a set of country-specific emissions factors and to estimate global pit latrine CH4 emissions. Between 2000 and 2015 we project global emissions to fall from 5.2 to 3.8 Tg y(-1), or from ∼ 2% to ∼ 1% of global anthropogenic CH4 emissions, due largely to urbanization in China. Two and a half billion people still lack improved sanitation services, however, and progress toward universal access to improved sanitation will likely drive future growth in pit latrine emissions. We discuss modeling results in the context of sustainable water, sanitation, and hygiene development and consider appropriate technologies to ensure hygienic sanitation while limiting CH4 emissions. We show that low-CH4 on-site alternatives like composting toilets may be price competitive with other CH4 mitigation measures in organic waste sectors, with marginal abatement costs ranging from 57 to 944 $/ton carbon dioxide equivalents (CO2e) in Africa and 46 to 97 $/ton CO2e in Asia.

  8. 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

  9. 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...

  10. Emissivity of microstructured silicon.

    Science.gov (United States)

    Maloney, Patrick G; Smith, Peter; King, Vernon; Billman, Curtis; Winkler, Mark; Mazur, Eric

    2010-03-01

    Infrared transmittance and hemispherical-directional reflectance data from 2.5 to 25 microm on microstructured silicon surfaces have been measured, and spectral emissivity has been calculated for this wavelength range. Hemispherical-total emissivity is calculated for the samples and found to be 0.84 before a measurement-induced annealing and 0.65 after the measurement for the sulfur-doped sample. Secondary samples lack a measurement-induced anneal, and reasons for this discrepancy are presented. Emissivity numbers are plotted and compared with a silicon substrate, and Aeroglaze Z306 black paint. Use of microstructured silicon as a blackbody or microbolometer surface is modeled and presented, respectively.

  11. International Emission Trading Systems: Trade Level and Political Acceptability

    DEFF Research Database (Denmark)

    Boom, J-T.; Svendsen, Gert Tinggaard

    1999-01-01

    The Kyoto Protocol of December 1997 allows emission trade between countries that have committed themselves to an emission ceiling. This paper considers two schemes of emission trading: trade between governments and trade between emission sources. The two schemes are analyzed and the strengths...... and weaknesses of the two schemes are compared in a public choice setting which focuses on group size, selective incentives, entrepreneurship and lobbyism from industry. The result is threefold. First, the big countries (due to small group advantages) dominated the Kyoto negotiations. Second...

  12. An attempt to make an inventory of dust emissions in France; Tentative d`inventaire des emissions de poussieres en France

    Energy Technology Data Exchange (ETDEWEB)

    Bouscaren, R. [CITEPA, Centre Interprofessionnel Technique d`Etudes de la Pollution Atmospherique, 75 - Paris (France)

    1996-12-31

    The various dust emissions due to combustion and industrial processes, have been quantified; data and diagrams are presented for France from 1960 to 1995: the emission contributions from the residential and commercial sectors, industrial sector, power plants and road transportation are detailed and their evolutions are compared; emission charts are also presented, according to fuel type and dust granulometry. The importance of road transportation emissions is pointed out

  13. Secondary amyloidosis due to FMF.

    Science.gov (United States)

    Yonem, Ozlem; Bayraktar, Yusuf

    2007-06-01

    Familial Mediterranean fever (FMF) is an ethnically restricted disease with an autosomal recessive inheritance characterized by recurrent attacks of fever, painful manifestations in the abdomen, chest and joints. The disease affects mainly non-Ashkenazi Jews, Armenians, Turks Arabs and other people of Mediterranean origin. The disease may present at any age, more than 80% of patients being symptomatic by the age of 20. Although the inflammatory attacks that characterize the disease may sometimes be debilitating, secondary (AA) amyloidosis remains the most serious manifestation of FMF causing considerable morbidity due mostly to nephropathic amyloidosis. The largest series of secondary amyloidosis in FMF have been reported from Turkey. The pathophysiological steps in progressing a patient from FMF to amyloidosis are not definitely known. Daily treatment with colchicine can prevent both the attacks and amyloid deposition but no effective alternative treatment exists for colchicine resistant cases. Meanwhile more population based epidemiological and genetic data should be gathered by worldwide collaborative studies to elucidate the link between FMF and amyloidosis and to develop alternative therapies.

  14. Galactorrhea due to psychotropic drugs.

    Science.gov (United States)

    Kropp, S; Ziegenbein, M; Grohmann, R; Engel, R R; Degner, D

    2004-03-01

    Within the drug safety program in psychiatry AMSP ( Arzneimittelsicherheit in der Psychiatrie), severe adverse drug reactions (ADRs) are assessed. Currently 35 psychiatric hospitals and departments are participating in detecting severe ADRs. This paper focuses on prolactin-dependent ADRs such as gynecomastia and galactorrhea due to psychotropic medications. Related to the number of patients surveyed (122,562 from 1993 to 2000), these are rare events (0.03 % or 35 cases). Imputed drugs were mostly antipsychotics, but antidepressants were also imputed in single cases. In the group of antipsychotics, relative frequencies of galactorrhea were highest for amisulpride and risperidone and corresponded to the degree of D2 binding. Galactorrhea assessed as "severe" was accompanied by distressing symptoms such as pain, tension, enlargement of breasts, or soaked clothing. The AMSP data contribute to the knowledge on endocrine ADRs by the large number of patients examined and help clinicians select the appropriate drug if their patients have been prone to for these ADRs in the past.

  15. Field scale measurements of NH3 emissions

    Science.gov (United States)

    Neftel, Albrecht; Ammann, Christof; Kuhn, Uwe; Sintermann, Jörg; Lehuger, Simon; Gärtner, Andrea; Hirschberger, Rainer

    2010-05-01

    The uncertainty in the ammonia emissions after application of organic manure contributes to a large extent to the overall uncertainties of the nitrogen budget of managed grassland systems (Ammann et al., 2009). Due to the sticky nature of the ammonia molecule and the variability of the emission fluxes the experimental determination is still a major challenge and a wide spread range of emission factors can be found in the literature. We report on two field experiments performed in August 2009 at the NitroEurope site in Oensingen, Switzerland. The ammonia emission flux after liquid manure application was investigated simultaneously by various micrometeorological methods: (1) a mass balance approach measuring the horizontal advection flux with open-path FTIR sensors (Gärtner et al., 2008), (2) aerodynamic gradient methods, and (3) eddy covariance measurements based on a novel fast ammonia analyser. Due to the sequential application of the manure and the fast decrease of the ammonia volatilisation, detailed footprint calculations (Neftel et al., 2008) and corrections with a high temporal resolution were crucial for obtaining representative emission fluxes. The plausibility of flux measurements has been evaluated with back trajectories simulations (WindTrax, Flesch et al., 2009). The results of all applied flux measurement methods confirmed the low emission levels found earlier by Spirig et al. (2009). A comparison of the field observations with results of process oriented models showed considerable differences in the temporal course of the ammonia emission indicating the need for improvements of the models. References: Ammann, C., Spirig, C., Leifeld, J. and Neftel, A.: Assessment of the nitrogen and carbon budget of two managed temperate grassland fields, Agric. Ecosyst. Environ., 133, 150-162, 2009. Flesch, T.K., Harper, L.A., Desjardins, R.L., Gao, Z., and Crenna, B.: Multi-Source Emission Determination Using an Inverse-Dispersion Technique. Boundary-Layer Meteorol

  16. Alternative industrial carbon emissions benchmark based on input-output analysis

    Science.gov (United States)

    Han, Mengyao; Ji, Xi

    2016-12-01

    Some problems exist in the current carbon emissions benchmark setting systems. The primary consideration for industrial carbon emissions standards highly relate to direct carbon emissions (power-related emissions) and only a portion of indirect emissions are considered in the current carbon emissions accounting processes. This practice is insufficient and may cause double counting to some extent due to mixed emission sources. To better integrate and quantify direct and indirect carbon emissions, an embodied industrial carbon emissions benchmark setting method is proposed to guide the establishment of carbon emissions benchmarks based on input-output analysis. This method attempts to link direct carbon emissions with inter-industrial economic exchanges and systematically quantifies carbon emissions embodied in total product delivery chains. The purpose of this study is to design a practical new set of embodied intensity-based benchmarks for both direct and indirect carbon emissions. Beijing, at the first level of carbon emissions trading pilot schemes in China, plays a significant role in the establishment of these schemes and is chosen as an example in this study. The newly proposed method tends to relate emissions directly to each responsibility in a practical way through the measurement of complex production and supply chains and reduce carbon emissions from their original sources. This method is expected to be developed under uncertain internal and external contexts and is further expected to be generalized to guide the establishment of industrial benchmarks for carbon emissions trading schemes in China and other countries.

  17. Alternative industrial carbon emissions benchmark based on input-output analysis

    Science.gov (United States)

    Han, Mengyao; Ji, Xi

    2016-05-01

    Some problems exist in the current carbon emissions benchmark setting systems. The primary consideration for industrial carbon emissions standards highly relate to direct carbon emissions (power-related emissions) and only a portion of indirect emissions are considered in the current carbon emissions accounting processes. This practice is insufficient and may cause double counting to some extent due to mixed emission sources. To better integrate and quantify direct and indirect carbon emissions, an embodied industrial carbon emissions benchmark setting method is proposed to guide the establishment of carbon emissions benchmarks based on input-output analysis. This method attempts to link direct carbon emissions with inter-industrial economic exchanges and systematically quantifies carbon emissions embodied in total product delivery chains. The purpose of this study is to design a practical new set of embodied intensity-based benchmarks for both direct and indirect carbon emissions. Beijing, at the first level of carbon emissions trading pilot schemes in China, plays a significant role in the establishment of these schemes and is chosen as an example in this study. The newly proposed method tends to relate emissions directly to each responsibility in a practical way through the measurement of complex production and supply chains and reduce carbon emissions from their original sources. This method is expected to be developed under uncertain internal and external contexts and is further expected to be generalized to guide the establishment of industrial benchmarks for carbon emissions trading schemes in China and other countries.

  18. Subsurface Emission Effects in AMSR-E Measurements: Implications for Land Surface Microwave Emissivity Retrieval

    Science.gov (United States)

    Galantowicz, John F.; Moncet, Jean-Luc; Liang, Pan; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    An analysis of land surface microwave emission time series shows that the characteristic diurnal signature associated with subsurface emission in sandy deserts carry over to arid and semi-arid region worldwide. Prior work found that diurnal variation of Special Sensor Microwave/Imager (SSM/I) brightness temperatures in deserts was small relative to International Satellite Cloud Climatology Project land surface temperature (LST) variation and that the difference varied with surface type and was largest in sand sea regions. Here we find more widespread subsurface emission effects in Advanced Microwave Scanning Radiometer-EOS (AMSR-E) measurements. The AMSR-E orbit has equator crossing times near 01:30 and 13 :30 local time, resulting in sampling when near-surface temperature gradients are likely to be large and amplifying the influence of emission depth on effective emitting temperature relative to other factors. AMSR-E measurements are also temporally coincident with Moderate Resolution Imaging Spectroradiometer (MODIS) LST measurements, eliminating time lag as a source of LST uncertainty and reducing LST errors due to undetected clouds. This paper presents monthly global emissivity and emission depth index retrievals for 2003 at 11, 19, 37, and 89 GHz from AMSR-E, MODIS, and SSM/I time series data. Retrieval model fit error, stability, self-consistency, and land surface modeling results provide evidence for the validity of the subsurface emission hypothesis and the retrieval approach. An analysis of emission depth index, emissivity, precipitation, and vegetation index seasonal trends in northern and southern Africa suggests that changes in the emission depth index may be tied to changes in land surface moisture and vegetation conditions

  19. 2011 NATA - Emissions Sources

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes all emissions sources that were modeled in the 2011 National Air Toxics Assessment (NATA), inlcluding point, nonpoint, and mobile sources, and...

  20. National Emission Inventory (NEI)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data exchange allows states to submit data to the US Environmental Protection Agency's National Emissions Inventory (NEI). NEI is a national database of air...

  1. Galactic Diffuse Polarized Emission

    Indian Academy of Sciences (India)

    Ettore Carretti

    2011-12-01

    Diffuse polarized emission by synchrotron is a key tool to investigate magnetic fields in the Milky Way, particularly the ordered component of the large scale structure. Key observables are the synchrotron emission itself and the RM is by Faraday rotation. In this paper the main properties of the radio polarized diffuse emission and its use to investigate magnetic fields will be reviewed along with our current understanding of the galactic magnetic field and the data sets available. We will then focus on the future perspective discussing RM-synthesis – the new powerful instrument devised to unlock the information encoded in such an emission – and the surveys currently in progress like S-PASS and GMIMS.

  2. Timeresolved Speckle Analysis: Probing the Coherence of Excitonic Secondary Emission

    DEFF Research Database (Denmark)

    Langbein, Wolfgang; Hvam, Jørn Märcher; Zimmermann, R.

    1998-01-01

    A new technique to analyze the time-dependent coherence of light emitted in a non-specular direction is presented. We demonstrate that the coherence degree of the emission can be deduced from the intensity fluctuations over the emission directions (speckles). The secondary emission of excitons...... in semiconductor quantum wells is investigated. Here, a partial coherence results from an interplay between scattering due to static disorder and inelastic relaxation, without any influence of the radiative decay. The temperature dependence is well explained by dephasing due to phonon scattering....

  3. Field emission electron source

    Science.gov (United States)

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  4. Electron Emission Projection Imager

    CERN Document Server

    Baturin, Stanislav S

    2016-01-01

    A new projection type imaging system is presented. The system can directly image the field emission site distribution on a cathode surface by making use of anode screens in the standard parallel plate configuration. The lateral spatial resolution of the projector is on the order of 1 {\\mu}m. The imaging sensitivity to the field emission current can be better than the current sensitivity of a typical electrometer, i.e. less than 1 nA.

  5. Pulmonary Complications due to Esophagectomy

    Directory of Open Access Journals (Sweden)

    Yashar Talebi

    2011-08-01

    Full Text Available Introduction: Esophageal carcinoma is the scourge of human beings. Pulmonary compli-cations in patients who have undergone operation are common (20-30% of cases and there are no suitable tools and ways to predict these complications. Methods: During a period of 10 years, from March 1998 to February 2007, 200 patients (150 male and 50 female underwent Esophagectomy due to esophageal carcinoma in thoracic surgery ward retrospectively. Complications include the length of hospitalization, mechanical ventilation, morbidity and mortality. Patients’ risk factors include age, preoperative chemo-radiotherapy, stage of the disease and preoperative spirometry condition. Results: We grouped our patients into three categories: Normal (FEV1 ≥ 80% predicted, mildly impaired (FEV1 65% to 79% predicted, more severely impaired (FEV1 < 65% predicted.Although almost all patients had radiographic pulmonary abnormalities, significant pulmonary complications occurred in 40 patients (20% which underwent Esophagectomy. Pleural effusion and atelectasia in 160 patients (80%. 24 patients needed chest-tube insertion. 20 patients (10% developed ARDS. 14 patients (7% developed chylothorax. 20 patients (10% of patients died during their postoperative hospital stay. 30 patients (15% required mechanical ventilation for greater than 48 hours. Conclusion: We reviewed a number of preoperative clinical variables to determine whether they contributed to postoperative pulmonary complications as well as other outcomes. In general, age, impaired pulmonary function especially in those patients with FEV1 less than 65% predicted was associated with prolonged hospital length of stay (LOS. In fact pulmonary complications rate after Esophagectomy are high and there was associated mortality and morbidity.

  6. Otomycosis due to filamentous fungi.

    Science.gov (United States)

    García-Agudo, Lidia; Aznar-Marín, Pilar; Galán-Sánchez, Fátima; García-Martos, Pedro; Marín-Casanova, Pilar; Rodríguez-Iglesias, Manuel

    2011-10-01

    Otomycosis is common throughout the world but barely studied in Spain. Our objective was to determine the microbiological and epidemiological characteristics of this pathology in Cadiz (Spain) between 2005 and 2010. Samples from patients with suspicion of otomycosis underwent a direct microscopic examination and culture on different media for fungi and bacteria. Mycological cultures were incubated at 30°C for at least seven days. Identification of fungi was based on colonial morphology and microscopic examination of fungal structure. From a total of 2,633 samples, microbial growth was present in 1,375 (52.2%) and fungal isolation in 390 (28.4%). We identified 228 yeasts and 184 filamentous fungi (13.4% of positive cultures and 47.2% of otomycosis), associated with yeasts in 22 cases (5.6%). The most frequent species were Aspergillus flavus (42.4%), A. niger (35.9%), A. fumigatus (12.5%), A. candidus (7.1%), A. terreus (1.6%), and Paecilomyces variotii (0.5%). Infection was predominant in men (54.9%) and patients beyond 55 years old (46.8%). The most common clinical symptoms were itching (98.9%), otalgia (59.3%), and hypoacusis (56.0%). Fall season reported the lowest number of cases (20.1%). Incidence of otomycosis and fungi producing otomycosis vary within the distinct geographical areas. In Cadiz, this infection is endemic due to warm temperatures, high humidity, sea bathing, and wind, which contributes to disseminate the conidia. Despite Aspergillus niger has been reported as the main causative agent, A. flavus is predominant in Cadiz. Although infection is usually detected in warm months, we observed a homogeneous occurrence of otomycosis in almost all the seasons.

  7. Telomere attrition due to infection.

    Directory of Open Access Journals (Sweden)

    Petteri Ilmonen

    Full Text Available BACKGROUND: Telomeres--the terminal caps of chromosomes--become shorter as individuals age, and there is much interest in determining what causes telomere attrition since this process may play a role in biological aging. The leading hypothesis is that telomere attrition is due to inflammation, exposure to infectious agents, and other types of oxidative stress, which damage telomeres and impair their repair mechanisms. Several lines of evidence support this hypothesis, including observational findings that people exposed to infectious diseases have shorter telomeres. Experimental tests are still needed, however, to distinguish whether infectious diseases actually cause telomere attrition or whether telomere attrition increases susceptibility to infection. Experiments are also needed to determine whether telomere erosion reduces longevity. METHODOLOGY/PRINCIPAL FINDINGS: We experimentally tested whether repeated exposure to an infectious agent, Salmonella enterica, causes telomere attrition in wild-derived house mice (Mus musculus musculus. We repeatedly infected mice with a genetically diverse cocktail of five different S. enterica strains over seven months, and compared changes in telomere length with sham-infected sibling controls. We measured changes in telomere length of white blood cells (WBC after five infections using a real-time PCR method. Our results show that repeated Salmonella infections cause telomere attrition in WBCs, and particularly for males, which appeared less disease resistant than females. Interestingly, we also found that individuals having long WBC telomeres at early age were relatively disease resistant during later life. Finally, we found evidence that more rapid telomere attrition increases mortality risk, although this trend was not significant. CONCLUSIONS/SIGNIFICANCE: Our results indicate that infectious diseases can cause telomere attrition, and support the idea that telomere length could provide a molecular

  8. Changes in Dimethyl Sulfide Oceanic Distribution due to Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Cameron-Smith, P; Elliott, S; Maltrud, M; Erickson, D; Wingenter, O

    2011-02-16

    Dimethyl sulfide (DMS) is one of the major precursors for aerosols and cloud condensation nuclei in the marine boundary layer over much of the remote ocean. Here they report on coupled climate simulations with a state-of-the-art global ocean biogeochemical model for DMS distribution and fluxes using present-day and future atmospheric CO{sub 2} concentrations. They find changes in zonal averaged DMS flux to the atmosphere of over 150% in the Southern Ocean. This is due to concurrent sea ice changes and ocean ecosystem composition shifts caused by changes in temperature, mixing, nutrient, and light regimes. The largest changes occur in a region already sensitive to climate change, so any resultant local CLAW/Gaia feedback of DMS on clouds, and thus radiative forcing, will be particularly important. A comparison of these results to prior studies shows that increasing model complexity is associted with reduced DMS emissions at the equator and increased emissions at high latitudes.

  9. Mechanisms of Increased Particle and VOC Emissions during DPF Active Regeneration and Practical Emissions Considering Regeneration.

    Science.gov (United States)

    Yamada, Hiroyuki; Inomata, Satoshi; Tanimoto, Hiroshi

    2017-02-27

    Mechanisms involved in increased particle and volatile organic compound (VOC) emissions during active and parked active regenerations of a diesel particulate filter (DPF) were investigated using heavy-duty trucks equipped with both a urea selective catalytic reduction system and a DPF (SCR + DPF) and a DPF-only. Particle emissions increased in the later part of the regeneration period but the mechanisms were different above and below 23 nm. Particles above 23 nm were emitted due to the lower filtering efficiency of the DPF because of the decreasing amount of soot trapped during regeneration. Small particles below 23 nm were thought to be mainly sulfuric acid particles produced from SO2 trapped by the catalyst, being released and oxidized during regeneration. Contrary to the particle emissions, VOCs increased in the earlier part of the regeneration period. The mean molecular weights of the VOCs increased gradually as the regeneration proceeded. To evaluate "practical emissions" in which increased emissions during the regeneration were considered, a Regeneration Correction Factor (RCF), which is the average emission during one cycle of regeneration/emission in normal operation, was adopted. The RCFs of PM and VOCs were 1.1-1.5, and those of PNs were as high as 3-140, although they were estimated from a limited number of observations.

  10. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... in the atmosphere. This may warm the climate due to a prolonged lifetime of the potent greenhouse gas methane in the atmosphere. However, oxidized BVOCs may participate in formation or growth of aerosols, which in turn may mitigate climate warming. Climate change in the Arctic, an area characterized by short...... dependent and the emissions will increase in a future warmer climate. The aims of this dissertation were to study BVOC emission rates and blends from arctic ecosystems and to reveal the effect of climate change on BVOC emissions from the Arctic. BVOC emissions were measured in ambient and modified...

  11. Future aerosol emissions: a multi-model comparison

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven J.; Rao, Shilpa; Riahi, Keywan; van Vuuren, Detlef P.; Calvin, Katherine V.; Kyle, Page

    2016-08-02

    This paper compares projections over the 21st century of SO2, BC, and OC emissions from three technologically detailed, long-term integrated assessment models. The character of the projections and the response of emissions due to a comprehensive climate policy are discussed. In a continuation of historical experience, aerosol and precursor emissions are increasingly decoupled from carbon dioxide emissions over the 21st century. Implementation of a comprehensive climate policy further reduces emissions, although there is significant variation in this response by sector and by model. Differences in model responses can be traced to specific characteristics of reference case end-use and supply-side technology deployment and emissions control assumptions, which are detailed by sector.

  12. Improved inventory for heavy metal emissions from stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Hoffmann, Leif

    for stationary combustion plants and the corresponding improved emission inventories for the following HMs: Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pb), Selenium (Se) and Zinc (Zn). The report presents data for the year 2009 and time series for 1990......-2009. The report also include methodology, references and an uncertainty estimate. In Denmark, stationary combustion plants are among the most important emission sources for heavy metals. Emissions of all heavy metals have decreased considerably (73 % - 92 %) since 1990. The main HM emission sources are coal...... combustion, waste incineration, residual oil combustion and in 2009 also combustion of biomass. The emission from waste incineration plants has decreased profoundly also in recent years due to installation and improved performance of flue gas cleaning devices. The emission from power plants have also...

  13. Greenhouse gases emissions, growth and the energy mix in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Gustavo A. [Departamento de Analisis Economico, Universidad de La Laguna (Spain); Fundacion de Estudios de Economia Aplicada (FEDEA), Madrid (Spain); Instituto Complutense de Analisis Economico (ICAE), UCM, Madrid (Spain)

    2010-11-15

    The importance of energy on greenhouse gases (GHG) emissions is reflected by the fact that 65% of said emissions in the World are currently due to the use and production of energy. However, most empirical emission models are found within the Environmental Kuznetz Curve (EKC) framework, which focuses on the relationship between emissions and economic development. Ang's (2007, 2008) papers are some of the exceptions that simultaneously study the relationship between emissions, growth and energy. With respect to Ang's research, we contribute on two important aspects. First, while Ang uses a particular country as the study and use time series techniques, we take advantage of a panel data set of 24 European countries between 1990 and 2006 and use a Dynamic Panel Data (DPD) framework. Second, the impact of energy consumption on emissions would depend on the primary energy mix and on the final use of this energy, and we consider both factors in the model. (author)

  14. Improved inventory for heavy metal emissions from stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Hoffmann, Leif

    for stationary combustion plants and the corresponding improved emission inventories for the following HMs: Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pb), Selenium (Se) and Zinc (Zn). The report presents data for the year 2009 and time series for 1990......-2009. The report also include methodology, references and an uncertainty estimate. In Denmark, stationary combustion plants are among the most important emission sources for heavy metals. Emissions of all heavy metals have decreased considerably (73 % - 92 %) since 1990. The main HM emission sources are coal...... combustion, waste incineration, residual oil combustion and in 2009 also combustion of biomass. The emission from waste incineration plants has decreased profoundly also in recent years due to installation and improved performance of flue gas cleaning devices. The emission from power plants have also...

  15. NO2 DOAS Measurements of Traffic Emissions by Chasing Cars

    Science.gov (United States)

    Zhu, Ying; Lipkowitsch, Ivo; Chan, Ka Lok; Bräu, Melanie; Wenig, Mark

    2016-04-01

    On this poster we present NO2 measurements using a Cavity-Enhanced DOAS on a measurement bus which we used to chase other vehicles to measure their NO2 emissions. Emissions of nitrogen oxides from on-road vehicles have received highly attention recently due to the increasing trend of ambient NOx level. It is particularly important to identify and quantify the direct emission and secondary formation of NO2 contributed by traffic emissions, in order to study the impact to the local air quality. We sampled on-road emissions in different environments and different driving conditions (e.g. urban, highway, different speeds). We analyse the data set in terms of spatial and temporal variability to search for temporal and spatial patterns. We present mean values sorted for different vehicle types, distance to the target car and travelling speeds to provide an emission data base from this measurement study.

  16. 47 CFR 78.103 - Emissions and emission limitations.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION RELAY SERVICE Technical Regulations § 78.103 Emissions and emission limitations. (a) A... television signals. (b) Any emission appearing on a frequency outside of the channel authorized for a...: At least 25 decibels below the mean power of the emission; (ii) On any frequency above the...

  17. The travel-related carbon dioxide emissions of atmospheric researchers

    Science.gov (United States)

    Stohl, A.

    2008-11-01

    Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who like other scientists rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of CO2. In this paper, the CO2 emissions of the employees working at an atmospheric research institute (the Norwegian Institute for Air Research, NILU) caused by all types of business travel (conference visits, workshops, field campaigns, instrument maintainance, etc.) were calculated for the years 2005 2007. It is estimated that more than 90% of the emissions were caused by air travel, 3% by ground travel and 5% by hotel usage. The travel-related annual emissions were between 1.9 and 2.4 t CO2 per employee or between 3.9 and 5.5 t CO2 per scientist. For comparison, the total annual per capita CO2 emissions are 4.5 t worldwide, 1.2 t for India, 3.8 t for China, 5.9 t for Sweden and 19.1 t for Norway. The travel-related CO2 emissions of a NILU scientist, occurring in 24 days of a year on average, exceed the global average annual per capita emission. Norway's per-capita CO2 emissions are among the highest in the world, mostly because of the emissions from the oil industry. If the emissions per NILU scientist derived in this paper are taken as representative for the average Norwegian researcher, travel by Norwegian scientists would nevertheless account for a substantial 0.2% of Norway's total CO2 emissions. Since most of the travel-related emissions are due to air travel, water vapor emissions, ozone production and contrail formation further increase the relative importance of NILU's travel in terms of radiative forcing.

  18. HST/ACS Lyman alpha imaging of the nearby starburst ESO338-IG04

    CERN Document Server

    Hayes, M; Mas-Hesse, J M; Kunth, D; Leitherer, C; Petrosian, A

    2005-01-01

    ESO338-IG04 is a well known, local, luminous Blue Compact Galaxy. It has a complex morphology and contains a central young starburst with compact young star clusters. The galaxy was imaged using HST/ACS in the Lyman alpha line and continuum. Using the Starburst99 synthetic spectra and other imaging data from HST/WFPC2 we developed a technique that allows us to make the first photometrically valid continuum subtraction for the LYa line. Our results are in qualitative agreement with the models of LYa escape being regulated by kinematical properties of the interstellar medium. The line-only image shows LYa in both emission and absorption. Notably, emission is seen from central bright young clusters and is in spatial agreement with the features present in a longslit spectrum taken with HST/STIS. Diffuse LYa emission regions are seen surrounding the central starburst where photons escape after one or more resonant scatterings in HI. These regions dominate the total LYa output. Photometry reveals a total LYa flux o...

  19. Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature

    Directory of Open Access Journals (Sweden)

    A. Guenther

    2006-01-01

    Full Text Available Reactive gases and aerosols are produced by terrestrial ecosystems, processed within plant canopies, and can then be emitted into the above-canopy atmosphere. Estimates of the above-canopy fluxes are needed for quantitative earth system studies and assessments of past, present and future air quality and climate. The Model of Emissions of Gases and Aerosols from Nature (MEGAN is described and used to quantify net terrestrial biosphere emission of isoprene into the atmosphere. MEGAN is designed for both global and regional emission modeling and has global coverage with ~1 km2 spatial resolution. Field and laboratory investigations of the processes controlling isoprene emission are described and data available for model development and evaluation are summarized. The factors controlling isoprene emissions include biological, physical and chemical driving variables. MEGAN driving variables are derived from models and satellite and ground observations. Tropical broadleaf trees contribute almost half of the estimated global annual isoprene emission due to their relatively high emission factors and because they are often exposed to conditions that are conducive for isoprene emission. The remaining flux is primarily from shrubs which have a widespread distribution. The annual global isoprene emission estimated with MEGAN ranges from about 500 to 750 Tg isoprene (440 to 660 Tg carbon depending on the driving variables which include temperature, solar radiation, Leaf Area Index, and plant functional type. The global annual isoprene emission estimated using the standard driving variables is ~600 Tg isoprene. Differences in driving variables result in emission estimates that differ by more than a factor of three for specific times and locations. It is difficult to evaluate isoprene emission estimates using the concentration distributions simulated using chemistry and transport models, due to the substantial uncertainties in other model components, but at

  20. Emissions from Biomass Burning in the Yucatan

    Science.gov (United States)

    Yokelson, R.; Crounse, J. D.; DeCarlo, P. F.; Karl, T.; Urbanski, S.; Atlas, E.; Campos, T.; Shinozuka, Y.; Kapustin, V.; Clarke, A. D.; Weinheimer, A.; Knapp, D. J.; Montzka, D. D.; Holloway, J.; Weibring, P.; Flocke, F.; Zheng, W.; Toohey, D.; Wennberg, P. O.; Wiedinmyer, C.; Mauldin, L.; Fried, A.; Richter, D.; Walega, J.; Jimenez, J. L.

    2009-01-01

    In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle species were measured from 20 deforestation and crop residue fires on the Yucatan peninsula. This included two trace gases useful as indicaters of BB (HCN and acetonitrile) and several rarely, or never before, measured species: OH, peroxyacetic acid, propanoic acid, hydrogen peroxide, methane sulfonic acid, and sulfuric acid. Crop residue fires emitted more organic acids and ammonia than deforestation fires, but the emissions from the main fire types were otherwise fairly similar. The Yucatan fires emitted unusually amounts of SO2 and particle chloride, likely due to a strong marine influence on the peninsula.

  1. Shunting effect in explosive electron emission

    Science.gov (United States)

    Mesyats, G. A.; Parkevich, E. V.; Pikuz, S. A.; Yalandin, M. I.

    2016-10-01

    An explanation is given to the results of an experiment on studying the explosive electron emission in a wire-cathode diode where a strongly nonuniform energy deposition into the wire material was observed using an X pinch as a radiation source for projection x-ray imaging. The specific input energy, contrary to the well-known observations, was not a maximum at the wire end, i.e., in the region of the strongest electric field, and the wire explosion occurred in the bulk, distant from the end. This is accounted for by the contribution of the wire side surface to explosive electron emission and by the gas desorption from the wire intensely heated by a current of density 108 A/cm2. Thus, the space between anode and cathode (wire end) is bridged by two plasmas: one generated due to the explosive electron emission from the wire side surface and the other produced from the desorbed gas.

  2. Stable field emission from nanoporous silicon carbide.

    Science.gov (United States)

    Kang, Myung-Gyu; Lezec, Henri J; Sharifi, Fred

    2013-02-15

    We report on a new type of stable field emitter capable of electron emission at levels comparable to thermal sources. Such an emitter potentially enables significant advances in several important technologies which currently use thermal electron sources. These include communications through microwave electronics, and more notably imaging for medicine and security where new modalities of detection may arise due to variable-geometry x-ray sources. Stable emission of 6 A cm(-2) is demonstrated in a macroscopic array, and lifetime measurements indicate these new emitters are sufficiently robust to be considered for realistic implementation. The emitter is a monolithic structure, and is made in a room-temperature process. It is fabricated from a silicon carbide wafer, which is formed into a highly porous structure resembling an aerogel, and further patterned into an array. The emission properties may be tuned both through control of the nanoscale morphology and the macroscopic shape of the emitter array.

  3. Sectoral and regional expansion of emissions trading

    Energy Technology Data Exchange (ETDEWEB)

    Boehringer, Christoph; Bouwe, Dijkstra; Rosendahl, Knut Einar

    2011-07-01

    We consider an international emissions trading scheme with partial sectoral and regional coverage. Sectoral and regional expansion of the trading scheme is beneficial in aggregate, but not necessarily for individual countries. We simulate international CO{sub 2} emission quota markets using marginal abatement cost functions and the Copenhagen 2020 climate policy targets for selected countries that strategically allocate emissions in a bid to manipulate the quota price. Quota exporters and importers generally have conflicting interests about admitting more countries to the trading coalition, and our results indicate that some countries may lose substantially when the coalition expands in terms of new countries. For a given coalition, expanding sectoral coverage makes most countries better off, but some countries (notably the USA and Russia) may lose out due to loss of strategic advantages. In general, exporters tend to have stronger strategic power than importers.(Author)

  4. Outstanding field emission properties of wet-processed titanium dioxide coated carbon nanotube based field emission devices

    Science.gov (United States)

    Xu, Jinzhuo; Xu, Peng; Ou-Yang, Wei; Chen, Xiaohong; Guo, Pingsheng; Li, Jun; Piao, Xianqing; Wang, Miao; Sun, Zhuo

    2015-02-01

    Field emission devices using a wet-processed composite cathode of carbon nanotube films coated with titanium dioxide exhibit outstanding field emission characteristics, including ultralow turn on field of 0.383 V μm-1 and threshold field of 0.657 V μm-1 corresponding with a very high field enhancement factor of 20 000, exceptional current stability, and excellent emission uniformity. The improved field emission properties are attributed to the enhanced edge effect simultaneously with the reduced screening effect, and the lowered work function of the composite cathode. In addition, the highly stable electron emission is found due to the presence of titanium dioxide nanoparticles on the carbon nanotubes, which prohibits the cathode from the influence of ions and free radical created in the emission process as well as residual oxygen gas in the device. The high-performance solution-processed composite cathode demonstrates great potential application in vacuum electronic devices.

  5. Identifying and characterizing major emission point sources as a basis for geospatial distribution of mercury emissions inventories

    Science.gov (United States)

    Steenhuisen, Frits; Wilson, Simon J.

    2015-07-01

    Mercury is a global pollutant that poses threats to ecosystem and human health. Due to its global transport, mercury contamination is found in regions of the Earth that are remote from major emissions areas, including the Polar regions. Global anthropogenic emission inventories identify important sectors and industries responsible for emissions at a national level; however, to be useful for air transport modelling, more precise information on the locations of emission is required. This paper describes the methodology applied, and the results of work that was conducted to assign anthropogenic mercury emissions to point sources as part of geospatial mapping of the 2010 global anthropogenic mercury emissions inventory prepared by AMAP/UNEP. Major point-source emission sectors addressed in this work account for about 850 tonnes of the emissions included in the 2010 inventory. This work allocated more than 90% of these emissions to some 4600 identified point source locations, including significantly more point source locations in Africa, Asia, Australia and South America than had been identified during previous work to geospatially-distribute the 2005 global inventory. The results demonstrate the utility and the limitations of using existing, mainly public domain resources to accomplish this work. Assumptions necessary to make use of selected online resources are discussed, as are artefacts that can arise when these assumptions are applied to assign (national-sector) emissions estimates to point sources in various countries and regions. Notwithstanding the limitations of the available information, the value of this procedure over alternative methods commonly used to geo-spatially distribute emissions, such as use of 'proxy' datasets to represent emissions patterns, is illustrated. Improvements in information that would facilitate greater use of these methods in future work to assign emissions to point-sources are discussed. These include improvements to both national

  6. Emissions trading: principles and practice

    National Research Council Canada - National Science Library

    Tietenberg, T.H

    2006-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 The Evolution of Emissions Trading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 The Evolution of Design Features...

  7. Reducing ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2011-01-01

    Danish application procedure, when increasing the animal production, has tried to make the acceptance procedure quicker and dynamic ensuring that new technology is adopted quicker and that the farm is located in the right place. It is concluded that the new application process so far has not lived up......The NEC directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the largest reductions since 1990...... and the article looks at the measures and costs involved. The conclusion is that the costs have been under 3 €/kg NH3-N. The findings suggest that the same measures might be cheaper in the Netherlands and Denmark than in the UK and the USA due to technology advances and stricter regulations in the past. The new...

  8. An Emission Inventory of Polycyclic Aromatic Hydrocarbons in China

    Science.gov (United States)

    Mu, Xilong; Zhu, Xianlei; Wang, Xuesong

    2015-04-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are among the most dangerous compounds due to their high carcinogenic and mutagenic character. Emission inventory provides the primary data to account for the sources of ambient PAHs and server as a necessary database for effective PAHs pollution control. China is experiencing fast economic growth and large energy consumption, which might result in a large amount of PAHs anthropogenic emissions. Therefore, based on the previous studies and combined recently field emission measurements as well as socio-economic activity data, the development of a nationwide PAHs emission inventory is needed. In this work, the emission inventory of 16 PAHs listed as U.S. Environmental Protection Agency priority pollutants in China in the year 2012 is compiled. The emission amounts of PAHs were estimated as annual rates of emission-related activities multiplied by respective emission factors. The activities such as fuel consumption, including fossil fuel and biofuel, and socio-economic statistics were obtained from yearbook released by Chinese central government and/or provincial governments, as well as related industry reports. Emission factors were derived from the related literature. Recently reported emission factors from local measurements were used. The total emissions of PAHs were 120611 ton in 2012. In China, PAHs were emitted predominantly from domestic combustion of coal and biofuel, coking industry and motor vehicles, accounting for 72% of the total amount. PAHs emission profiles were significantly different between China and the other countries. The emission profile in China featured a relatively higher portion of high molecular weight species with carcinogenic potential due to large contributions of domestic combustion and coking industry. Domestic combustion of straw, coal and firewood emitted 19464 ton, 8831 ton, and 5062 ton of PAHs, respectively, which were much higher than those in other countries. Emission per capita showed

  9. Particulate emissions from diesel engines: correlation between engine technology and emissions.

    Science.gov (United States)

    Fiebig, Michael; Wiartalla, Andreas; Holderbaum, Bastian; Kiesow, Sebastian

    2014-03-07

    In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted.Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions.Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the

  10. Evaluation of Mobile Source Emissions and Trends

    Science.gov (United States)

    Dallmann, Timothy Ryan

    characterized for nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), formaldehyde, BC, as well as optical properties of the emitted particles. Emission factor distributions for all species were skewed, with a small fraction of trucks contributing disproportionately to total emissions. These findings confirm that the use of catalyzed DPF systems is leading to increased primary NO2 emissions. Absorption and scattering cross-section emission factors were used to calculate the aerosol single scattering albedo (SSA, at 532 nm) for individual truck exhaust plumes, which averaged 0.14 +/- 0.03. This value of aerosol SSA is very low compared to typical values (0.90-0.99) observed in ambient air studies. It is indicative of a strongly light-absorbing aerosol, due to the high BC emissions that are a characteristic feature of diesel exhaust PM emissions. Measurements at the Caldecott tunnel also included efforts to quantify light-duty (LD) gasoline vehicle emission factors, and further investigation of the relative contributions of on-road gasoline and diesel engines to air pollutant emissions. Measurements of CO, NOx, PM2.5, BC, and organic aerosol (OA) were made in a tunnel traffic bore where LD vehicles account for >99% of total traffic. Measured pollutant concentrations were apportioned between LD gasoline vehicles and diesel trucks, and fleet-average emission factors were quantified for LD gasoline vehicles using a carbon balance method. Diesel trucks contributed 18 +/- 3, 22 +/- 5, 44 +/- 8% of measured NOx, OA, and BC concentrations, respectively, despite accounting for factors and overall fuel consumption for gasoline and diesel engines were used to describe the relative contributions of these sources to overall on-road vehicle emissions. Gasoline engines were found to be the dominant source of CO, an insignificant source of BC, and a relatively minor source of on-road OA emissions at urban, state, and national scales. Measurements at the Caldecott tunnel also

  11. The Nature of Emission from Optical Breakdown Induced by Pulses of fs and ns Duration

    Energy Technology Data Exchange (ETDEWEB)

    Carr, C W; Feit, M D; Rubenchik, A M; Demange, P; Kucheyev, S; Shirk, M D; Radousky, H B; Demos, S G

    2004-11-09

    Spectral emission from optical breakdown in the bulk of a transparent dielectric contains information about the nature of the breakdown medium. We have made time resolved measurements of the breakdown induced emission caused by nanosecond and femtosecond infrared laser pulses. We previously demonstrated that the emission due to ns pulses is blackbody in nature allowing determination of the fireball temperature and pressure during and after the damage event. The emission due to femtosecond pulse breakdown is not blackbody in nature; two different spectral distributions being noted. In one case, the peak spectral distribution occurs at the second harmonic of the incident radiation, in the other the distribution is broader and flatter and presumably due to continuum generation. The differences between ns and fs breakdown emission can be explained by the differing breakdown region geometries for the two pulse durations. The possibility to use spectral emission as a diagnostic of the emission region morphology will be discussed.

  12. What to Expect After Your Due Date

    Science.gov (United States)

    ... Management Education & Events Advocacy For Patients About ACOG What to Expect After Your Due Date Home For ... Your Due Date FAQ069, August 2011 PDF Format What to Expect After Your Due Date Pregnancy What ...

  13. Emissivity Measurement of Semitransparent Textiles

    Directory of Open Access Journals (Sweden)

    P. Bison

    2012-01-01

    Full Text Available In the textiles production industry it is more and more common to advertise new textiles, especially for sportswear, by claiming their ability to emit IR radiation in the long wave band at a higher degree with respect to normal clothes, that is highly beneficial to improve sporting performances. Three textiles are compared, one normal and two “special,” with Ag+ ions and carbon powder added, with different colors. The emissivity of the textiles has been measured to determine if it is increased in the “special” textiles with respect to the normal one. No substantial increase has been noticed. Nonetheless, the test implied some nonstandard procedures due to the semitransparent nature of the textiles, in comparison with the normal procedure that is commonly used on opaque surfaces.

  14. Light absorbing carbon emissions from commercial shipping

    Science.gov (United States)

    Lack, Daniel; Lerner, Brian; Granier, Claire; Baynard, Tahllee; Lovejoy, Edward; Massoli, Paola; Ravishankara, A. R.; Williams, Eric

    2008-07-01

    Extensive measurements of the emission of light absorbing carbon aerosol (LAC) from commercial shipping are presented. Vessel emissions were sampled using a photoacoustic spectrometer in the Gulf of Mexico region. The highest emitters (per unit fuel burnt) are tug boats, thus making significant contributions to local air quality in ports. Emission of LAC from cargo and non cargo vessels in this study appears to be independent of engine load. Shipping fuel consumption data (2001) was used to calculate a global LAC contribution of 133(+/-27) Ggyr-1, or ~1.7% of global LAC. This small fraction could have disproportionate effects on both air quality near port areas and climate in the Arctic if direct emissions of LAC occur in that region due to opening Arctic sea routes. The global contribution of this LAC burden was investigated using the MOZART model. Increases of 20-50 ng m-3 LAC (relative increases up to 40%) due to shipping occur in the tropical Atlantic, Indonesia, central America and the southern regions of South America and Africa.

  15. Observations of Diffuse Ultraviolet Emission from Draco

    CERN Document Server

    Sujatha, N V; Suresh, Rahul; Henry, Richard Conn; Bianchi, Luciana

    2010-01-01

    We have studied small scale (2 arcmin) spatial variation of the diffuse UV radiation using a set of 11 GALEX deep observations in the constellation of Draco. We find a good correlation between the observed UV background and the IR 100 micron flux, indicating that the dominant contributor of the diffuse background in the field is the scattered starlight from the interstellar dust grains. We also find strong evidence of additional emission in the FUV band which is absent in the NUV band. This is most likely due to Lyman band emission from molecular hydrogen in a ridge of dust running through the field and to line emissions from species such as C IV (1550 A) and Si II (1533 A) in the rest of the field. A strong correlation exists between the FUV/NUV ratio and the FUV intensity in the excess emission regions in the FUV band irrespective of the optical depth of the region. The optical depth increases more rapidly in the UV than the IR and we find that the UV/IR ratio drops off exponentially with increasing IR due ...

  16. Evaluation of gas emissions from coal stockpile

    Energy Technology Data Exchange (ETDEWEB)

    Kozinc, J.; Zupancic-Kralj, L.; Zapusek, A. [University of Ljubljana, Ljubljana (Slovenia). Faculty of Chemistry & Chemical Technology

    2004-05-01

    Gas emissions of carbon dioxide, methane, dimethylsulfide, carbon monoxide and oxygen from a coal stockpile in Velenje were determined. Gases from the coal stockpile were collected in Alltech Standard sampling bags and then analysed using a capillary gas chromatograph and electrochemical sensors. A flame ionisation detector equipped with a Zr/Ni catalytic reactor was used for the determination of methane and carbon dioxide. Dimethylsulfide was detected with a flame photometric detector, and the concentrations of carbon monoxide and oxygen were determined by use of electrochemical sensors. The results showed that the main influence on gas emissions is related to the ambient temperature. Emissions of carbon dioxide during summer 2001 (average temperature during sampling period was 24{sup o}C) were approximately 30-times higher than during winter 2002 (average temperature during sampling period was -2{sup o}C) and were also influenced by the oxygen concentration. Carbon dioxide is mainly formed by oxidation of coal. Methane and dimethylsulfide are desorbed from coal, and are present in higher concentrations in stockpile emissions when stockpiles are renewed. The dimethylsulfide concentration, in contrast to laboratory experiments in stockpile emissions, falls immediately due to photo-degradation.

  17. Fine particle emissions from residential wood combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tissari, J.

    2008-07-01

    Residential wood combustion (RWC) appliances have the high probability of incomplete combustion, producing e.g. fine particles and hazardous organic compounds. In this thesis, the fine particle number and mass emissions, particle composition and morphology, and gas emissions were investigated from the modern (MMH) and conventional masonry heaters (CMH), sauna stoves (SS) and pellet burner. The investigation was based on laboratory and field experiments applying extensive and unique particle sampling methods. The appliance type, fuel and operational practices were found to affect clearly the fine particle emissions. In good combustion conditions (e.g. in pellet combustion), the fine particle mass (PM{sub 1}) emission factors were low, typically below 0.3 g kg-1, and over 90% of the PM{sub 1} consisted of inorganic compounds (i.e fine ash). From the CMH the typical PM{sub 1} values were 1.6-1.8 g kg-1, and from the SS 2.7-5.0 g kg-1, but were strongly dependent on operational practices. The smouldering combustion in CMH increased PM{sub 1} emission up to 10 g kg-1. The good secondary combustion in the MMH reduced the particle organic matter (POM) and gaseous emissions, but not substantially the elemental carbon (EC, i.e. soot) emission, and the typical PM{sub 1} values were 0.7-0.8 g kg-1. The particle number emissions were high, and did not correspond with the completition of combustion. The particle number distributions were mainly dominated by ultrafine (<100 nm) particles, but varied dependent on combustion conditions. The electronmicroscopy analyses showed that ultrafine particles were composed mainly of K, S and Zn. From the smouldering combustion, particles were composed mainly of carbon compounds and they had a closed sinteredlike structure, due to organic matter on the particles. Controlling the gasification rate via the primary air supply, log and batch size, as well as fuel moisture content, is important for the reduction of emissions in batch combustion

  18. Advanced CIDI Emission Control System Development

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, Christine

    2006-05-31

    Ford Motor Company, with ExxonMobil and FEV, participated in the Department of Energy's (DOE) Ultra-Clean Transportation Fuels Program with the goal to develop an innovative emission control system for light-duty diesel vehicles. The focus on diesel engine emissions was a direct result of the improved volumetric fuel economy (up to 50%) and lower CO2 emissions (up to 25%) over comparable gasoline engines shown in Europe. Selective Catalytic Reduction (SCR) with aqueous urea as the NOx reductant and a Catalyzed Diesel Particulate Filter (CDPF) were chosen as the primary emission control system components. The program expected to demonstrate more than 90% durable reduction in particulate matter (PM) and NOx emissions on a light-duty truck application, based on the FTP-75 drive cycle. Very low sulfur diesel fuel (<15 ppm-wt) enabled lower PM emissions, reduced fuel economy penalty due to the emission control system and improved long-term system durability. Significant progress was made toward a durable system to meet Tier 2 Bin 5 emission standards on a 6000 lbs light-duty truck. A 40% reduction in engine-out NOx emissions was achieved with a mid-size prototype diesel engine through engine recalibration and increased exhaust gas recirculation. Use of a rapid warm-up strategy and urea SCR provided over 90% further NOx reduction while the CDPF reduced tailpipe PM to gasoline vehicle levels. Development work was conducted to separately improve urea SCR and CDPF system durability, as well as improved oxidation catalyst function. Exhaust gas NOx and ammonia sensors were also developed further. While the final emission control system did not meet Tier 2 Bin 5 NOx after 120k mi of aging on the dynamometer, it did meet the standards for HC, NMOG, and PM, and an improved SCR catalyst was shown to have potential to meet the NOx standard, assuming the DOC durability could be improved further. Models of DOC and SCR function were developed to guide the study of several key

  19. Emission control system

    Science.gov (United States)

    Parrish, Clyde F. (Inventor); Chung, J. Landy (Inventor)

    2009-01-01

    Methods and apparatus utilizing hydrogen peroxide are useful to reduce SOx and mercury (or other heavy metal) emissions from combustion flue gas streams. The methods and apparatus may further be modified to reduce NOx emissions. Continuous concentration of hydrogen peroxide to levels approaching or exceeding propellant-grade hydrogen peroxide facilitates increased system efficiency. In this manner, combustion flue gas streams can be treated for the removal of SOx and heavy metals, while isolating useful by-products streams of sulfuric acid as well as solids for the recovery of the heavy metals. Where removal of NOx emissions is included, nitric acid may also be isolated for use in fertilizer or other industrial applications.

  20. Practical acoustic emission testing

    CERN Document Server

    2016-01-01

    This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

  1. Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature

    Directory of Open Access Journals (Sweden)

    A. Guenther

    2006-01-01

    Full Text Available Reactive gases and aerosols are produced by terrestrial ecosystems, processed within plant canopies, and can then be emitted into the above-canopy atmosphere. Estimates of the above-canopy fluxes are needed for quantitative earth system studies and assessments of past, present and future air quality and climate. The Model of Emissions of Gases and Aerosols from Nature (MEGAN is described and used to quantify net terrestrial biosphere emission of isoprene into the atmosphere. MEGAN is designed for both global and regional emission modeling and has global coverage with ~1 km2 spatial resolution. Field and laboratory investigations of the processes controlling isoprene emission are described and data available for model development and evaluation are summarized. The factors controlling isoprene emissions include biological, physical and chemical driving variables. MEGAN driving variables are derived from models and satellite and ground observations. Broadleaf trees, mostly in the tropics, contribute about half of the estimated global annual isoprene emission due to their relatively high emission factors and because they are often exposed to conditions that are conducive for isoprene emission. The remaining flux is primarily from shrubs which are widespread and dominate at higher latitudes. MEGAN estimates global annual isoprene emissions of ~600 Tg isoprene but the results are very sensitive to the driving variables, including temperature, solar radiation, Leaf Area Index, and plant functional type. The annual global emission estimated with MEGAN ranges from about 500 to 750 Tg isoprene depending on the driving variables that are used. Differences in estimated emissions are more than a factor of 3 for specific times and locations. It is difficult to evaluate isoprene emission estimates using the concentration distributions simulated using chemistry and transport models due to the substantial uncertainties in other model components

  2. The effects of energy paths and emission controls and standards on future trends in China's emissions of primary air pollutants

    Directory of Open Access Journals (Sweden)

    Y. Zhao

    2014-03-01

    Full Text Available To examine the efficacy of China's actions to control atmospheric pollution, three levels of growth of energy consumption and three levels of implementation of emission controls are estimated, generating a total of nine combined activity-emission control scenarios that are then used to estimate trends of national emissions of primary air pollutants through 2030. The emission control strategies are expected to have more effects than the energy paths on the future emission trends for all the concerned pollutants. As recently promulgated national action plans of air pollution prevention and control (NAPAPPC are implemented, China's anthropogenic pollutant emissions should decline. For example, the emissions of SO2, NOx, total primary particulate matter (PM, PM10, and PM2.5 are estimated to decline 7%, 20%, 41%, 34%, and 31% from 2010 to 2030, respectively, in the "best guess" scenario that includes national commitment of energy saving policy and partial implementation of NAPAPPC. Should the issued/proposed emission standards be fully achieved, a less likely scenario, annual emissions would be further reduced, ranging from 17% (for primary PM2.5 to 29% (for NOx declines in 2015, and the analogue numbers would be 12% and 24% in 2030. The uncertainties of emission projections result mainly from the uncertain operational conditions of swiftly proliferating air pollutant control devices and lack of detailed information about emission control plans by region. The predicted emission trends by sector and chemical species raise concerns about current pollution control strategies: the potential for emissions abatement in key sectors may be declining due to the near saturation of emission control devices use; risks of ecosystem acidification could rise because emissions of alkaline base cations may be declining faster than those of SO2; and radiative forcing could rise because emissions of positive-forcing carbonaceous aerosols may decline more slowly than

  3. Development of experimental methods to investigate non-exhaust particle emissions from a light duty vehicle

    OpenAIRE

    Mathissen, Marcel

    2014-01-01

    Vehicle related non-exhaust particle emissions resulting from the abrasion of brakes, tires, road and the resuspension of road dust may contribute considerably to ambient air pollution. While exhaust particulate matter emissions are expected to decrease, non-exhaust emissions will rise due to higher traffic volume and the absence of legal regulations. However, there is still limited scientific knowledge of non-exhaust emissions, especially for the climate conditions found in central Europe...

  4. Field emission electronics

    CERN Document Server

    Egorov, Nikolay

    2017-01-01

    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  5. Mercury emission from crematoria.

    Science.gov (United States)

    Santarsiero, Anna; Settimo, Gaetano; Dell'andrea, Elena

    2006-01-01

    The purpose of this study, undertaken at a cremator representing an example of current equipment and cremation practices in use in Italy, is to assess the possible mercury emitted during cremation and substantiate the current data available. This paper reports some preliminary results concerning mercury and total particulate matter emissions during three cremation processes. The obtained results gave a mercury concentration ranging from 0.005 to 0.300 mg/m3 and a mercury emission factor ranging from 0.036 to 2.140 g/corpse cremated. The total particulate matter concentration range was 1.0 to 2.4 mg/m3.

  6. Immense Magnetic Response of Exciplex Light Emission due to Correlated Spin-Charge Dynamics

    Science.gov (United States)

    Wang, Yifei; Sahin-Tiras, Kevser; Harmon, Nicholas J.; Wohlgenannt, Markus; Flatté, Michael E.

    2016-01-01

    As carriers slowly move through a disordered energy landscape in organic semiconductors, tiny spatial variations in spin dynamics relieve spin blocking at transport bottlenecks or in the electron-hole recombination process that produces light. Large room-temperature magnetic-field effects (MFEs) ensue in the conductivity and luminescence. Sources of variable spin dynamics generate much larger MFEs if their spatial structure is correlated on the nanoscale with the energetic sites governing conductivity or luminescence such as in coevaporated organic blends within which the electron resides on one molecule and the hole on the other (an exciplex). Here, we show that exciplex recombination in blends exhibiting thermally activated delayed fluorescence produces MFEs in excess of 60% at room temperature. In addition, effects greater than 4000% can be achieved by tuning the device's current-voltage response curve by device conditioning. Both of these immense MFEs are the largest reported values for their device type at room temperature. Our theory traces this MFE and its unusual temperature dependence to changes in spin mixing between triplet exciplexes and light-emitting singlet exciplexes. In contrast, spin mixing of excitons is energetically suppressed, and thus spin mixing produces comparatively weaker MFEs in materials emitting light from excitons by affecting the precursor pairs. Demonstration of immense MFEs in common organic blends provides a flexible and inexpensive pathway towards magnetic functionality and field sensitivity in current organic devices without patterning the constituent materials on the nanoscale. Magnetic fields increase the power efficiency of unconditioned devices by 30% at room temperature, also showing that magnetic fields may increase the efficiency of the thermally activated delayed fluorescence process.

  7. Aktsendikorpus ja võõrkeele aktsendi uurimine / Lya Meister, Einar Meister

    Index Scriptorium Estoniae

    Meister, Lya

    2012-01-01

    Antakse ülevaade aktsendi olemusest ja teoreetilistest käsitlustest, tutvustatakse eesti keelt võõrkeelena kõnelevate inimeste hääldusnäidetel põhinevat, Tallinna Tehnikaülikooli juures loodavat aktsendikorpust, ka selle eesmärke, ülesehitust ja salvestusi

  8. BRIGHT Lights, BIG City: Massive Galaxies, Giant Ly-A Nebulae, and Proto-Clusters

    Energy Technology Data Exchange (ETDEWEB)

    van Breugel, W; Reuland, M; de Vries, W; Stanford, A; Dey, A; Kurk, J; Venemans, B; Rottgering, H; Miley, G; De Breuck, C; Dopita, M; Sutherland, R; Bland-Hawthorn, J

    2002-08-01

    High redshift radio galaxies are great cosmological tools for pinpointing the most massive objects in the early Universe: massive forming galaxies, active super-massive black holes and proto-clusters. They report on deep narrow-band imaging and spectroscopic observations of several z > 2 radio galaxy fields to investigate the nature of giant Ly-{alpha} nebulae centered on the galaxies and to search for over-dense regions around them. They discuss the possible implications for our understanding of the formation and evolution of massive galaxies and galaxy clusters.

  9. Lya escape from z~0.03 star-forming galaxies: the dominant role of outflows

    CERN Document Server

    Wofford, A; Salzer, J

    2013-01-01

    The usefulness of H I Lyman-alpha photons for characterizing star formation in the distant universe is limited by our understanding of the astrophysical processes that regulate their escape from galaxies. These processes can only be observed in detail out to a few x100 Mpc. Past nearby (z=0.03. The galaxies cover a broad range of luminosity, oxygen abundance, and reddening. In this paper, we characterize the observed Lyman-alpha lines and establish correlations with fundamental galaxy properties. We find seven emitters. These host young (\\le 10 Myr) stellar populations, have rest-frame equivalent widths in the range 1-12 \\AA, and have Lyman-alpha escape fractions within the COS aperture in the range 1-12 %. One emitter has a double-peaked Lyman-alpha with peaks 370 km/s apart and a stronger blue peak. Excluding this object, the emitters have Lyman-alpha and O I \\lambda 1302 offsets from H-alpha in agreement with expanding shell models and LBG observations. The absorbers have offsets that are almost consistent...

  10. Observations of radio galaxy mrc 1138-262: merging galaxies embedded in a giant Lya halo

    Directory of Open Access Journals (Sweden)

    J. D. Kurk

    2002-01-01

    Full Text Available La radio galaxia MRC 1138-262 a z = 2:16 probablemente es una galaxia de mayor brillo en el c umulo que se encuentra un estado inicial de evoluci on. Aqu presentamos observaciones del luminoso halo de l neas de emisi on y de las componentes estelares de esta radio galaxia. Las im agenes opticas de banda angosta en H muestran un halo mucho m as peque~no con una morfolog a muy diferente al halo Ly . Proponemos un modelo en el que la parte interior del halo est a fotoionizada directamente por iluminaci on del n ucleo activo de la galaxia o por fotones UV de estrellas j ovenes. Lejos del n ucleo ( 25 kpc hay una regi on de emisi on Ly muy aumentada. En esa posici on es probable que la ionizaci on por choques sea importante seg un indica la curvatura del radio jet. La espectroscop a de varias nubes de cont nuo en el halo muestra que, aunque hay diferencias entre las caracter sticas de emisi on y de absorci on de espectros de varias regiones, estas tienen propiedades similares a las galaxias con \\Lyman-break". Esto es evidencia adicional en favor de un escenario en que galaxias masivas se forman jer arquicamente a partir de bloques m as peque~nos.

  11. Aktsendikorpus ja võõrkeele aktsendi uurimine / Lya Meister, Einar Meister

    Index Scriptorium Estoniae

    Meister, Lya

    2012-01-01

    Antakse ülevaade aktsendi olemusest ja teoreetilistest käsitlustest, tutvustatakse eesti keelt võõrkeelena kõnelevate inimeste hääldusnäidetel põhinevat, Tallinna Tehnikaülikooli juures loodavat aktsendikorpust, ka selle eesmärke, ülesehitust ja salvestusi

  12. Stimulated emission from donor transitions in silicon

    Science.gov (United States)

    Pavlov; Zhukavin; Orlova; Shastin; Kirsanov; Hubers; Auen; Riemann

    2000-05-29

    The observation of far-infrared stimulated emission from shallow donor transitions in silicon is reported. Lasing with a wavelength of 59 &mgr;m due to the neutral donor intracenter 2p(0)-->1s(E) transition in Si:P pumped by CO2 laser radiation is obtained. Populations of D0 and D- center states and the balance of the radiation absorption and amplification are theoretically analyzed.

  13. Attributing land-use change carbon emissions to exported biomass

    Energy Technology Data Exchange (ETDEWEB)

    Saikku, Laura, E-mail: laura.saikku@helsinki.fi [University of Helsinki, P.O Box 65, 00014 University of Helsinki (Finland); Soimakallio, Sampo, E-mail: sampo.soimakallio@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT (Finland); Pingoud, Kim, E-mail: kim.pingoud@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT (Finland)

    2012-11-15

    In this study, a simple, transparent and robust method is developed in which land-use change (LUC) emissions are retrospectively attributed to exported biomass products based on the agricultural area occupied for the production. LUC emissions account for approximately one-fifth of current greenhouse gas emissions. Increasing agricultural exports are becoming an important driver of deforestation. Brazil and Indonesia are used as case studies due to their significant deforestation in recent years. According to our study, in 2007, approximately 32% and 15% of the total agricultural land harvested and LUC emissions in Brazil and Indonesia respectively were due to exports. The most important exported single items with regard to deforestation were palm oil for Indonesia and bovine meat for Brazil. To reduce greenhouse gas (GHG) emissions effectively worldwide, leakage of emissions should be avoided. This can be done, for example, by attributing embodied LUC emissions to exported biomass products. With the approach developed in this study, controversial attribution between direct and indirect LUC and amortization of emissions over the product life cycle can be overcome, as the method operates on an average basis and annual level. The approach could be considered in the context of the UNFCCC climate policy instead of, or alongside with, other instruments aimed at reducing deforestation. However, the quality of the data should be improved and some methodological issues, such as the allocation procedure in multiproduct systems and the possible dilution effect through third parties not committed to emission reduction targets, should be considered. - Highlights: Black-Right-Pointing-Pointer CO{sub 2} emissions from land use changes are highly important. Black-Right-Pointing-Pointer Attribution of land use changes for products is difficult. Black-Right-Pointing-Pointer Simple and robust method is developed to attribute land use change emissions.

  14. Warming increases isoprene emissions from an arctic fen.

    Science.gov (United States)

    Lindwall, Frida; Svendsen, Sophie Sylvest; Nielsen, Cecilie Skov; Michelsen, Anders; Rinnan, Riikka

    2016-05-15

    Emissions of biogenic volatile organic compounds (BVOCs) from dry ecosystems at high latitudes respond strongly to small increases in temperature, and warm canopy surface temperatures drive emissions to higher levels than expected. However, it is not known whether emissions from wetlands, cooled by through-flowing water and higher evapotranspiration show similar response to warming as in drier ecosystems. Climate change will cause parts of the Arctic to experience increased snow fall, which delays the start of the growing season, insulates soil from low temperatures in winter, and increases soil moisture and possibly nutrient availability. Currently the effects of increasing snow depth on BVOC emissions are unknown. BVOC emissions were measured in situ across the growing season in a climate experiment, which used open top chambers to increase temperature and snow fences to increase winter snow depth. The treatments were arranged in a full factorial design. Measurements took place during two growing seasons in a fen ecosystem in west Greenland. BVOC samples collected by an enclosure technique in adsorbent cartridges were analysed using gas chromatography-mass spectrometry. Gross ecosystem production (GEP) was measured with a closed chamber technique, to reveal any immediate effect of treatments on photosynthesis, which could further influence BVOC emissions. Isoprene made up 84-92% of the emitted BVOCs. Isoprene emission increased 240 and 340% due to an increase in temperature of 1.3 and 1.6°C in 2014 and 2015, respectively. Isoprene emissions were 25 times higher in 2015 than in 2014 most likely due to a 2.4°C higher canopy air temperature during sampling in 2015. Snow addition had no significant effect on isoprene emissions even though GEP was increased by 24%. Arctic BVOC emissions respond strongly to rising temperatures in wet ecosystems, suggesting a large increase in arctic emissions in a future warmer climate.

  15. Inventory and forecasting of maritime emissions in the Belgian sea territory, an activity-based emission model

    Science.gov (United States)

    Schrooten, Liesbeth; De Vlieger, Ina; Int Panis, Luc; Styns, Karel; Torfs, Rudi

    Air quality policy has focussed on land-based emissions for decades. In recent years, it has become increasingly clear that emissions from sea-going vessels can no longer be ignored. There is a growing need for detailed emission inventories to evaluate the impact of this transport mode on air quality and health. In this paper we present MOPSEA, an activity-based emission model to determine emissions from sea-going vessels. The model considers shipping activities of sea-going vessels on Belgian territory, combined with individual vessel characteristics. We apply this model to study the effects of recent international efforts to reduce emissions from sea-going vessels in Belgian territorial waters for the current fleet and for two scenarios up to 2010. The emission model for Belgium, based on different vessel operating areas, reveals that most maritime emissions from the main engines will increase. CO 2 emissions will increase by 2-9% over the 2004-2010 period due to an increase in shipping activity. NO X emissions are projected to rise between 1% and 8% because the increase in activity offsets the reductions from the international maritime organisation (IMO) and European regulations. In contrast, SO 2 emissions will decrease by at least 50% in 6 years time. The switch of auxiliaries from heavy fuel oil to diesel oil at berth results in a large emission reduction (33%) for PM and small reductions for CO 2, NO X, CO and HC (4-5%). The choice between a bottom-up versus top-down approach can have important implications for the allocation of maritime emissions. The MOPSEA bottom-up model allocates only 0.7 Mton CO 2 to Belgium, compared to 24.2 Mton CO 2 based on bunker fuel inventories.

  16. Far-Field Testing Method of Spurious Emission Produced by HF RFID

    OpenAIRE

    Nikola Gvozdenovic; Ralph Prestros; Mecklenbräuker, Christoph F.

    2016-01-01

    We present measurements of spurious emission produced by high-frequency radio frequency identification (HF RFID) using carrier frequency of 13.56 MHz. HF RFID tags produce unwanted emission due to rectification and more generally due to nonlinearity of analog front end. Depending on the conducting material of an HF RFID coil and surrounding dielectric material, the coil behaves as more or less good antenna on some harmonic frequencies. Exact characterization and analysis of unwanted emission ...

  17. 5 CFR 732.301 - Due process.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Due process. 732.301 Section 732.301...) NATIONAL SECURITY POSITIONS Due Process and Reporting § 732.301 Due process. When an agency makes an... any determination. (b) Comply with all applicable administrative due process requirements, as...

  18. Earth system commitments due to delayed mitigation

    Science.gov (United States)

    Pfister, Patrik L.; Stocker, Thomas F.

    2016-01-01

    As long as global CO2 emissions continue to increase annually, long-term committed Earth system changes grow much faster than current observations. A novel metric linking this future growth to policy decisions today is the mitigation delay sensitivity (MDS), but MDS estimates for Earth system variables other than peak temperature (ΔT max) are missing. Using an Earth System Model of Intermediate Complexity, we show that the current emission increase rate causes a ΔT max increase roughly 3-7.5 times as fast as observed warming, and a millenial steric sea level rise (SSLR) 7-25 times as fast as observed SSLR, depending on the achievable rate of emission reductions after the peak of emissions. These ranges are only slightly affected by the uncertainty range in equilibrium climate sensitivity, which is included in the above values. The extent of ocean acidification at the end of the century is also strongly dependent on the starting time and rate of emission reductions. The preservable surface ocean area with sufficient aragonite supersaturation for coral reef growth is diminished globally at an MDS of roughly 25%-80% per decade. A near-complete loss of this area becomes unavoidable if mitigation is delayed for a few years to decades. Also with respect to aragonite, 12%-18% of the Southern Ocean surface become undersaturated per decade, if emission reductions are delayed beyond 2015-2040. We conclude that the consequences of delaying global emission reductions are much better captured if the MDS of relevant Earth system variables is communicated in addition to current trends and total projected future changes.

  19. Influence of future anthropogenic emissions on climate, natural emissions, and air quality

    Science.gov (United States)

    Jacobson, Mark Z.; Streets, David G.

    2009-04-01

    This study examines the effects of future anthropogenic emissions on climate, and the resulting feedback to natural emissions and air quality. Speciated sector- and region-specific 2030 emission factors were developed to produce gas and particle emission inventories that followed Special Report on Emission Scenarios (SRES) A1B and B1 emission trajectories. Current and future climate model simulations were run, in which anthropogenic emission changes affected climate, which fed back to natural emissions from lightning (NO, NO2, HONO, HNO3, N2O, H2O2, HO2, CO), soils (dust, bacteria, NO, N2O, H2, CH4, H2S, DMS, OCS, CS2), the ocean (bacteria, sea spray, DMS, N2O, H2, CH4), vegetation (pollen, spores, isoprene, monoterpenes, methanol, other VOCs), and photosynthesis/respiration. New methods were derived to calculate lightning flash rates as a function of size-resolved collisions and other physical principles and pollen, spore, and bacteria emissions. Although the B1 scenario was "cleaner" than the A1B scenario, global warming increased more in the B1 scenario because much A1B warming was masked by additional reflective aerosol particles. Thus neither scenario is entirely beneficial from a climate and health perspective, and the best control measure is to reduce warming gases and warming/cooling particles together. Lightning emissions declined by ˜3% in the B1 scenario and ˜12% in the A1B scenario as the number of ice crystals, thus charge-separating bounceoffs, decreased. Net primary production increased by ˜2% in both scenarios. Emissions of isoprene and monoterpenes increased by ˜1% in the A1B scenario and 4-5% in the B1 scenario. Near-surface ozone increased by ˜14% in the A1B scenario and ˜4% in the B1 scenario, reducing ambient isoprene in the latter case. Gases from soils increased in both scenarios due to higher temperatures. Near-surface PM2.5 mass increased by ˜2% in the A1B scenario and decreased by ˜2% in the B1 scenario. The resulting 1.4% higher

  20. A blended land emissivity product from the Inter-Comparison of different Land Surface Emissivity Estimates

    Science.gov (United States)

    Norouzi, H.; Temimi, M.; Khanbilvardi, R.

    2012-12-01

    Passive microwave observations are routinely used to estimate rain rate, cloud liquid water, and total precipitable water. In order to have accurate estimations from microwave, the contribution of the surface should be accounted for. Over land, due to the complex interaction between the microwave signal and the soil surface, retrieval of land surface emissivity and other surface and subsurface parameters is not straightforward. Several microwave emissivity products from various microwave sensors have been proposed. However, lack of ground truth measurements makes the validation of these products difficult. This study aims to inter-compare several available emissivity products over land and ultimately proposes a unique blended product that overcomes the flaws of each individual product. The selected products are based on observations from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E), the Special Sensor Microwave Imager (SSM/I), the Advanced Microwave Sounding unit (AMSU), and the Special Sensor Microwave Imager/Sounder (SSMIS). In retrieval of emissivities from these sensors different methods and ancillary data have been used. Some inherent discrepancies between the selected products can be introduced by as the difference in geometry in terms of incident angle, spectral response, and the foot print size which can affect the estimations. Moreover, ancillary data especially skin temperature and cloud mask cover can cause significant discrepancies between various estimations. The time series and correlation between emissivity maps are explored to assess the consistency of emissivity variations with geophysical variable such as snow, precipitation and drought. Preliminary results reveal that inconsistency between products varies based on land cover type due to penetration depth effect and ancillary data. Six years of estimations are employed in this research study, and a global blended emissivity estimations based on all product with minimal discrepancies

  1. Acceleration of Small Dust Grains due to Charge Fluctuations

    CERN Document Server

    Hoang, Thiem

    2011-01-01

    We consider the acceleration of very small dust grains including Polycyclic Aromatic Hydrocarbons (PAHs) arising from the electrostatic interactions of dust grains that have charge fluctuates in time due to charging events. We simulate the charge fluctuations of very small grains due to their sticking collisions with electrons and ions in plasma and the emission of photoelectrons by UV photons using Monte Carlo method. We identify the acceleration induced by the charge fluctuations as the dominant acceleration mechanism of very small grains in the diffuse interstellar medium (ISM). We show that this acceleration mechanism is more efficient for environments with low ionization, where the charge fluctuations are slow but have a large amplitude. We also discuss the implications of the present mechanism for grain coagulation and shattering in the diffuse ISM, molecular clouds and protoplanetary disks.

  2. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has onl...

  3. Controlling spontaneous emission

    DEFF Research Database (Denmark)

    Lodahl, Peter

    dots (QDs) embedded in 3D photonic crystals consisting of air spheres in titanium dioxide. Performing time-resolved experiments, we show that the photonic crystals control the emission decay rate of excitons confined in the QDs1,2. By varying the lattice parameter of the photonic crystals, we...

  4. Aircraft Emissions Characterization

    Science.gov (United States)

    1988-03-01

    sample from each trap through a heated (1500C) six-port valve ’ Carle Instruments Model 5621) and onto the analytical column. The coLoponents in each...Environmental Protection, Vol. II. Aircraft Engine Emissions, Int. Civil Aviation Organ., 1981. 7. Nebel , G. J., "Benzene in Auto Exhaust," J. Air Poll

  5. Reaching peak emissions

    Science.gov (United States)

    Jackson, Robert B.; Canadell, Josep G.; Le Quéré, Corinne; Andrew, Robbie M.; Korsbakken, Jan Ivar; Peters, Glen P.; Nakicenovic, Nebojsa

    2016-01-01

    Rapid growth in global CO2 emissions from fossil fuels and industry ceased in the past two years, despite continued economic growth. Decreased coal use in China was largely responsible, coupled with slower global growth in petroleum and faster growth in renewables.

  6. Radio Emission from Exoplanets

    OpenAIRE

    George, Samuel J.; Stevens, Ian R.

    2008-01-01

    We present results from new low frequency observations of two extrasolar planetary systems (Epsilon Eridani and HD128311) taken at 150 MHz with the Giant Metrewave Radio Telescope (GMRT). We do not detect either system, but are able to place tight upper limits on their low frequency radio emission.

  7. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

  8. Methane emissions from ruminants

    African Journals Online (AJOL)

    user

    2011-02-21

    Feb 21, 2011 ... Review. Livestock-environment interactions: Methane emissions from ruminants. Aluwong, T.1* ... perception of air quality by human neighbours.The three ... on the climate; the global warming potential of methane is. 21-times that of ... has serious impact on high atmosphere ozone formation. It is important ...

  9. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has onl...... reveals presence of a true emission from all ears tested. It is concluded that the cochlear echo can be recorded in normal-hearing newborns with an extremely low rate of type I errors.......Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...... a minor effect on the power spectra, i.e. the maximum jumps from one spectral peak to another. Experiments with deconvolution demonstrate that the emission generating system at least at a fixed intensity can be regarded as being linear and characterized by its impulse response which is similar...

  10. Secondary emission gas chamber

    CERN Document Server

    In'shakov, V; Skvortsov, V

    2014-01-01

    For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

  11. Emission inventory for the road transport sector in Sardinia (Italy)

    Science.gov (United States)

    Bellasio, R.; Bianconi, R.; Corda, G.; Cucca, P.

    Atmospheric emission inventories are important tools for studying air quality and to set up possible remediation plans in areas characterised by nonattainment of the limit values established by legislation. In industrialised countries a considerable fraction of the emissions is due to road traffic, in particular in urban areas. For this reason emissions from road traffic must be estimated as accurately as possible, a task that can be performed, for the European vehicle fleet, thanks to the availability of the COPERT III methodology. This methodology is powerful and accurate, even if its algorithms can be difficult to apply in a regional emission inventory; moreover the collection of the necessary input data requires a lot of resources and time. This paper describes the road traffic emission inventory estimated for Region Sardinia (Italy) with a bottom-up approach. The estimation has been done by means of a software tool (EMITRA—EMIssions from road TRAnsport) which implements the COPERT III methodology. The resulting emission inventory has been compared against another emission inventory for Sardinia and against emission inventories for other Italian regions, to evaluate its reliability.

  12. Hydrogen cyanide exhaust emissions from in-use motor vehicles.

    Science.gov (United States)

    Baum, Marc M; Moss, John A; Pastel, Stephen H; Poskrebyshev, Gregory A

    2007-02-01

    Motor vehicle exhaust emissions are known to contain hydrogen cyanide (HCN), but emission rate data are scarce and, in the case of idling vehicles, date back over 20 years. For the first time, vehicular HCN exhaust emissions from a modern, in-use fleet at idle have been measured. The 14 tested light duty motor vehicles were operating at idle as these conditions are associated with the highest risk exposure scenarios (i.e., enclosed spaces). Vehicular HCN was detected in 89% of the sampled exhaust streams and did not correlate with instantaneous air-fuel-ratio or with any single, coemitted pollutant. However, a moderate correlation between HCN emissions and the product of carbon monoxide and nitric oxide emissions was observed under cold-start conditions. Fleet average, cold-start, undiluted HCN emissions were 105 +/- 97 ppbV (maximum: 278 ppbV), whereas corresponding emissions from vehicles operating under stabilized conditions were 79 +/- 71 ppbV (maximum: 245 ppbV); mean idle fleet HCN emission rates were 39 +/- 35 and 21 +/- 18 microg-min(-1) for cold-start and stabilized vehicles, respectively. The significance of these results is discussed in terms of HCN emissions inventories in the South Coast Air Basin of California and of health risks due to exposure to vehicular HCN.

  13. [Characteristic of Particulate Emissions from Concrete Batching in Beijing].

    Science.gov (United States)

    Xue, Yi-feng; Zhou, Zhen; Zhong, Lian-hong; Yan, Jing; Qu, Song; Huang, Yu-hu; Tian, He- zhong; Pan, Tao

    2016-01-15

    With the economic development and population growth in Beijing, there is a strong need for construction and housing, which leads to the increase of the construction areas. Meanwhile, as a local provided material, the production of concrete has been raised. In the process of concrete production by concrete batching, there are numerous particulates emitted, which have large effect on the atmospheric environment, however, systematic study about the tempo-spatial characteristics of pollutant emission from concrete batching is still rare. In this study, we estimated the emission of particulates from concrete batching from 1991 to 2012 using emission factor method, analyzed the tempo-spatial characteristics of pollutant emission, established the uncertainty range by adopting Monte-Carlo method, and predicted the future emission in 2020 based on the relative environmental and economical policies. The results showed that: (1) the emissions of particulates from concrete batching showed a trend of "first increase and then decrease", reaching the maximum in 2005, and then decreased due to stricter emission standard and enhanced environmental management. (2) according to spatial distribution, the emission of particulates from concrete batch mainly concentrated in the urban area with more human activities, and the area between the fifth ring and the sixth ring contributed the most. (3) through scenarios analysis, for further reducing the emission from concrete batching in 2020, more stricter standard for green production as well as powerful supervision is needed.

  14. Diesel emissions in Vienna

    Science.gov (United States)

    Horvath, H.; Kreiner, I.; Norek, C.; Preining, O.; Georgi, B.

    The aerosol in a non-industrial town normally is dominated by emissions from vehicles. Whereas gasoline-powered cars normally only emit a small amount of particulates, the emission by diesel-powered cars is considerable. The aerosol particles produced by diesel engines consist of graphitic carbon (GC) with attached hydrocarbons (HCs) including also polyaromatic HCs. Therefore the diesel particles can be carcinogenic. Besides diesel vehicles, all other combustion processes are also a source for GC; thus source apportionment of diesel emissions to the GC in the town is difficult. A direct apportionment of diesel emissions has been made possible by marking all the diesel fuel used by the vehicles in Vienna by a normally not occurring and easily detectable substance. All emitted diesel particles thus were marked with the tracer and by analyzing the atmospheric samples for the marking substance we found that the mass concentrations of diesel particles in the atmosphere varied between 5 and 23 μg m -3. Busy streets and calm residential areas show less difference in mass concentration than expected. The deposition of diesel particles on the ground has been determined by collecting samples from the road surface. The concentration of the marking substance was below the detection limit before the marking period and a year after the period. During the period when marked diesel fuel was used, the concentrations of the diesel particles settling to the ground was 0.012-0.07 g g -1 of collected dust. A positive correlation between the diesel vehicle density and the sampled mass of diesel vehicles exists. In Vienna we have a background diesel particle concentration of 11 μg m -3. This value increases by 5.5 μg m -3 per 500 diesel vehicles h -1 passing near the sampling location. The mass fraction of diesel particles of the total aerosol mass varied between 12.2 and 33%; the higher values were found in more remote areas, since diesel particles apparently diffuse easily

  15. N2O and NO2 Emissions from Heavy-Duty Diesel Trucks with Advanced Emission Controls

    Science.gov (United States)

    Preble, C.; Harley, R.; Kirchstetter, T.

    2014-12-01

    Diesel engines are the largest source of nitrogen oxides (NOx) emissions nationally, and also a major contributor to the black carbon (BC) fraction of fine particulate matter (PM). Recently, diesel particle filter (DPF) and selective catalytic reduction (SCR) emission control systems that target exhaust PM and NOx have become standard equipment on new heavy-duty diesel trucks. However, the deliberate catalytic oxidation of engine-out nitric oxide (NO) to nitrogen dioxide (NO2) in continuously regenerating DPFs leads to increased tailpipe emission of NO2. This is of potential concern due to the toxicity of NO2 and the resulting increases in atmospheric formation of other air pollutants such as ozone, nitric acid, and fine PM. While use of SCR reduces emissions of both NO and NO2, it may lead to increased emissions of nitrous oxide (N2O), a potent greenhouse gas. Here we report results from on-road measurements of heavy-duty diesel truck emissions conducted at the Port of Oakland and the Caldecott Tunnel in the San Francisco Bay Area. Emission factors (g pollutant per kg of diesel) were linked via recorded license plates to individual truck attributes, including engine model year and installed emission control equipment. Between 2009 and 2013, the fraction of DPF-equipped trucks at the Port of Oakland increased from 2 to 99%, and median engine age decreased from 11 to 6 years. Over the same period, fleet-average emission factors for black carbon and NOx decreased by 76 ± 22% and 53 ± 8%, respectively. However, direct emissions of NO2 increased, and consequently the NO2/NOx emission ratio increased from 0.03 ± 0.02 to 0.18 ± 0.03. Older trucks retrofitted with DPFs emitted approximately 3.5 times more NO2 than newer trucks equipped with both DPF and SCR. Preliminary data from summer 2014 measurements at the Caldecott Tunnel suggest that some older trucks have negative emission factors for N2O, and that for newer trucks, N2O emission factors have changed sign and

  16. Negative Emissions Technology

    Science.gov (United States)

    Day, Danny

    2006-04-01

    Although `negative emissions' of carbon dioxide need not, in principle, involve use of biological processes to draw carbon out of the atmosphere, such `agricultural' sequestration' is the only known way to remove carbon from the atmosphere on time scales comparable to the time scale for anthropogenic increases in carbon emissions. In order to maintain the `negative emissions' the biomass must be used in such a way that the resulting carbon dioxide is separated and permanently sequestered. Two options for sequestration are in the topsoil and via geologic carbon sequestration. The former has multiple benefits, but the latter also is needed. Thus, although geologic carbon sequestration is viewed skeptically by some environmentalists as simply a way to keep using fossil fuels---it may be a key part of reversing accelerating climate forcing if rapid climate change is beginning to occur. I will first review the general approach of agricultural sequestration combined with use of resulting biofuels in a way that permits carbon separation and then geologic sequestration as a negative emissions technology. Then I discuss the process that is the focus of my company---the EPRIDA cycle. If deployed at a sufficiently large scale, it could reverse the increase in CO2 concentrations. I also estimate of benefits --carbon and other---of large scale deployment of negative emissions technologies. For example, using the EPRIDA cycle by planting and soil sequestering carbon in an area abut In 3X the size of Texas would remove the amount of carbon that is being accumulated worldwide each year. In addition to the atmospheric carbon removal, the EPRIDA approach also counters the depletion of carbon in the soil---increasing topsoil and its fertility; reduces the excess nitrogen in the water by eliminating the need for ammonium nitrate fertilizer and reduces fossil fuel reliance by providing biofuel and avoiding natural gas based fertilizer production.

  17. Rents in the European power sector due to carbon trading

    Energy Technology Data Exchange (ETDEWEB)

    Keppler, Jan Horst; Cruciani, Michel [Centre de Geopolitique de l' Energie et des Matieres Premieres (CGEMP) Universite Paris - Dauphine (France)

    2010-08-15

    The European Union Emissions Trading Scheme (EU ETS) has imposed a price on the allowances for CO{sub 2} emissions of electricity companies. Integrating this allowance price into the price of electricity earns a rent for companies who have received these allowances for free. During Phase I, 2005-2007, rents corresponding to the aggregate value of allocated allowances amounted to roughly EUR 13 billion per year. However, due to the specific price-setting mechanism in electricity markets true rents were considerably higher. This is due to the fact that companies also that have not received any allowances gain additional infra-marginal rents to the extent that their variable costs are below the new market price after inclusion of the allowance price. Producers with low carbon emissions and low marginal costs thus also benefit substantially from carbon pricing. This paper develops a methodology to determine the specific interaction of the imposition of such a CO{sub 2} constraint and the price-setting mechanism in the electricity sector under the assumption of marginal cost pricing in a liberalized European electricity market. The article thus provides an empirical estimate of the true total rents of power producers during Phase I of the EU-ETS (2005-2007). The EU ETS generated in Phase I additional rents in excess of EUR 19 billion per year for electricity producers. These transfers are distributed very unevenly between different electricity producers. In a second step, the paper assesses the impact of switching from free allocation to an auctioning of allowances in 2013. We show that such a switch to auctioning will continue to create additional infra-marginal rents for certain producers and will leave the electricity sector as a whole better off than before the introduction of the EU ETS. (author)

  18. Infrared Emissivity Measurements of Building and Civil Engineering Materials: A New Device for Measuring Emissivity

    Science.gov (United States)

    Monchau, Jean-Pierre; Marchetti, Mario; Ibos, Laurent; Dumoulin, Jean; Feuillet, Vincent; Candau, Yves

    2014-10-01

    The knowledge of the infrared emissivity of materials used in buildings and civil engineering structures is useful for two specific approaches. First, quantitative diagnosis of buildings or civil engineering infrastructures by infrared thermography requires emissivity values in the spectral bandwidth of the camera used for measurements, in order to obtain accurate surface temperatures; for instance, emissivity in the band III domain is required when using cameras with uncooled detectors (such as micro-bolometer arrays). Second, setting up accurate thermal balances by numerical modeling requires the total emissivity value for a large wavelength domain; this is, for instance, the case for computing the road surface temperature to predict ice occurrence. Furthermore, periodical surveys of emissivity variations due to aging or soiling of surfaces could be useful in many situations such as thermal mapping of roads or building insulation diagnosis. The use of portable emissivity measurement devices is required for that purpose. A device using an indirect measurement method was previously developed in our lab; the method uses measurement of the reflectivity from a modulated IR source and requires calibration with a highly reflective surface. However, that device uses a low-frequency, thermal modulation well adapted to laboratory measurements but unfit for fast and in situ measurements. Therefore, a new, portable system which retains the principle of an indirect measurement but uses a faster-frequency, mechanical modulation more appropriate to outdoor measurements was developed. Both devices allow measurements in the broad m to m) and narrow m to m) bands. Experiments were performed on a large number of materials commonly used in buildings and civil engineering structures. The final objective of this work is to build a database of emissivity of these materials. A comparison of laboratory and on-site measurements of emissivity values obtained in both spectral bands will be

  19. Quantifying emission reduction contributions by emerging economics

    Energy Technology Data Exchange (ETDEWEB)

    Moltmann, Sara; Hagemann, Markus; Eisbrenner, Katja; Hoehne, Niklas [Ecofys GmbH, Koeln (Germany); Sterk, Wolfgang; Mersmann, Florian; Ott, Hermann E.; Watanabe, Rie [Wuppertal Institut (Germany)

    2011-04-15

    Further action is needed that goes far beyond what has been agreed so far under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol to 'prevent dangerous anthropogenic interference with the climate system', the ultimate objective of the UNFCCC. It is out of question that developed countries (Annex I countries) will have to take a leading role. They will have to commit to substantial emission reductions and financing commitments due to their historical responsibility and their financial capability. However, the stabilisation of the climate system will require global emissions to peak within the next decade and decline well below half of current levels by the middle of the century. It is hence a global issue and, thus, depends on the participation of as many countries as possible. This report provides a comparative analysis of greenhouse gas (GHG) emissions, including their national climate plans, of the major emitting developing countries Brazil, China, India, Mexico, South Africa and South Korea. It includes an overview of emissions and economic development, existing national climate change strategies, uses a consistent methodology for estimating emission reduction potential, costs of mitigation options, provides an estimate of the reductions to be achieved through the national climate plans and finally provides a comparison of the results to the allocation of emission rights according to different global effort-sharing approaches. In addition, the report discusses possible nationally appropriate mitigation actions (NAMAs) the six countries could take based on the analysis of mitigation options. This report is an output of the project 'Proposals for quantifying emission reduction contributions by emerging economies' by Ecofys and the Wuppertal Institute for the Federal Environment Agency in Dessau. It builds upon earlier joint work ''Proposals for contributions of emerging economies to the climate

  20. Emission sources contributing to tropospheric ozone over Equatorial Africa during the summer monsoon

    Science.gov (United States)

    Bouarar, I.; Law, K. S.; Pham, M.; Liousse, C.; Schlager, H.; Hamburger, T.; Reeves, C. E.; Cammas, J.-P.; Nédéléc, P.; Szopa, S.; Ravegnani, F.; Viciani, S.; D'Amato, F.; Ulanovsky, A.; Richter, A.

    2011-12-01

    A global chemistry-climate model LMDz_INCA is used to investigate the contribution of African and Asian emissions to tropospheric ozone over Central and West Africa during the summer monsoon. The model results show that ozone in this region is most sensitive to lightning NOx and to Central African biomass burning emissions. However, other emission categories also contribute significantly to regional ozone. The maximum ozone changes due to lightning NOx occur in the upper troposphere between 400 hPa and 200 hPa over West Africa and downwind over the Atlantic Ocean. Biomass burning emissions mainly influence ozone in the lower and middle troposphere over Central Africa, and downwind due to westward transport. Biogenic emissions of volatile organic compounds, which can be uplifted from the lower troposphere to higher altitudes by the deep convection that occurs over West Africa during the monsoon season, lead to maximum ozone changes in the lower stratosphere region. Soil NOx emissions over the Sahel region make a significant contribution to ozone in the lower troposphere. In addition, convective uplift of these emissions and subsequent ozone production are also an important source of ozone in the upper troposphere over West Africa. Concerning African anthropogenic emissions, they only make a small contribution to ozone compared to the other emission categories. The model results indicate that most ozone changes due to African emissions occur downwind, especially over the Atlantic Ocean, far from the emission regions. The import of Asian emissions also makes a considerable contribution to ozone concentrations above 150 hPa and has to be taken into account in studies of the ozone budget over Africa. Using IPCC AR5 (Intergovernmental Panel on Climate Change; Fifth Assessment Report) estimates of anthropogenic emissions for 2030 over Africa and Asia, model calculations show larger changes in ozone over Africa due to growth in Asian emissions compared to African emissions

  1. Estimation of carbon emissions from crown fires in Turkey

    Science.gov (United States)

    Kucuk, O.; Bilgili, E.

    2009-04-01

    Forest biomass consumption is an important index for carbon cycling. Forest fire represents one of the important sources of greenhouse gas (GHG) emissions due to biomass burning processes. Forest fire contribute to increasing atmospheric CO2 concentration therefore, role of forest fires in the global carbon cycle has received increasing interest. Various methods were used to estimation of carbon emission. IPCC methodology is commonly used for the calculation of GHG amounts released at forest fire in Europe especially on a national basis. Many European countries have done many studies relation to estimation of carbon emissions from forest fires. However, carbon emissions from forest fires were not estimated in Turkey. The objective of this paper was to estimate carbon emission from forest fires from 1997 to 2006 in three forest district directorate of Turkey. We have used IPCC methodology for estimation of carbon emission form forest fire in Turkey. The emission calculations associated with forest fires were carried out using the IPCC methodology for estimating emissions from biomass burning. According to IPCC methodology, the annual carbon release of gas is the product of parameters: Annual biomass loss by burning (kt), fraction of biomass oxidized on-site, carbon content (CC), emission ratio, N/C ratio. A set of forest fire data during 1997-2006 obtained from the Turkish Ministry of Environment and Forestry-General Directorate of Forestry Service. Fuel biomass and fuel consumption data were provided from experimental fires and biomass studies in Turkey. The highest carbon emission amount was CO2 gas. A wide range in carbon emissions of 0.37-94.85 Gg was caused by variability in pre-fire fuel characteristics (fuel size, distribution, fuel moisture and total load), fire type, fire season and fire weather, which affected fuel moisture and fire behavior. Keywords: Carbon emissions, Forest fire, Fuel consumption, IPCC, Turkey

  2. Towards a comprehensive emission inventory of terpenoids from boreal ecosystems

    Science.gov (United States)

    Tarvainen, V.; Hakola, H.; Rinne, J.; Hellén, H.; Haapanala, S.

    2007-07-01

    The biogenic volatile organic compound emissions in the south boreal, middle boreal and north boreal vegetation zones in Finland were calculated utilizing satellite land cover information and actual meteorological data in a BEIS-type canopy emission model. The sesquiterpene emissions from the boreal forest were estimated for the first time, and the inventory was further complemented by the inclusion of wetland isoprene emissions from open fens. Recently published results from emission measurements carried out in various parts of the boreal region were utilized in the compilation of the standard emission potentials and monoterpene emission spectra for the deciduous and coniferous forest categories and wetlands. The average annual isoprene emission fluxes from forests were 73, 56 and 45, and those of monoterpenes 657, 567 and 342 kg per km2 of forest area in the south boreal, middle boreal and north boreal vegetation zones, respectively. The average annual sesquiterpene fluxes were of the same order of magnitude as isoprene, being 54, 46 and 26 kg per km2 of forest area in the south boreal, middle boreal and north boreal vegetation zones, respectively. The isoprene emissions from wetlands were significant, contributing 3%, 18% and 31% of the annual isoprene emissions in the south boreal, middle boreal and north boreal vegetation zones, respectively. Throughout the boreal region, the main emitted monoterpenes were α-pinene and Δ3-carene, with significant contributions from β-pinene and sabinene in summer and autumn. Due to the new seasonal emission potentials of the coniferous species introduced in this work, the overwhelming role of spruce as the main isoprene and monoterpene emitter in the boreal forest is subdued. The new emission inventory also accentuates the role of the boreal deciduous trees as terpenoid emitters in the late summer months.

  3. Development of emission factors and emission inventories for motorcycles and light duty vehicles in the urban region in Vietnam.

    Science.gov (United States)

    Tung, H D; Tong, H Y; Hung, W T; Anh, N T N

    2011-06-15

    This paper reports on a 2-year emissions monitoring program launched by the Centre for Environmental Monitoring of the Vietnam Environment Administration which aimed at determining emission factors and emission inventories for two typical types of vehicle in Hanoi, Vietnam. The program involves four major activities. A database for motorcycles and light duty vehicles (LDV) in Hanoi was first compiled through a questionnaire survey. Then, two typical driving cycles were developed for the first time for motorcycles and LDVs in Hanoi. Based on this database and the developed driving cycles for Hanoi, a sample of 12 representative test vehicles were selected to determine vehicle specific fuel consumption and emission factors (CO, HC, NOx and CO(2)). This set of emission factors were developed for the first time in Hanoi with due considerations of local driving characteristics. In particular, it was found that the emission factors derived from Economic Commission for Europe (ECE) driving cycles and adopted in some previous studies were generally overestimated. Eventually, emission inventories for motorcycles and LDVs were derived by combining the vehicle population data, the developed vehicle specific emission factors and vehicle kilometre travelled (VKT) information from the survey. The inventory suggested that motorcycles contributed most to CO, HC and NOx emissions while LDVs appeared to be more fuel consuming.

  4. The primordial helium abundance from updated emissivities

    Energy Technology Data Exchange (ETDEWEB)

    Aver, Erik [Department of Physics, Gonzaga University, 502 E Boone Ave, Spokane, WA, 99258 (United States); Olive, Keith A.; Skillman, Evan D. [School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN, 55455 (United States); Porter, R.L., E-mail: aver@gonzaga.edu, E-mail: olive@umn.edu, E-mail: ryanlporter@gmail.com, E-mail: skillman@astro.umn.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA, 30602 (United States)

    2013-11-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y{sub p}. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, and Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, and Stasi'nska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y{sub p}. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increased variance (due to additional objects included). From a regression to zero metallicity, we determine Y{sub p} = 0.2465 ± 0.0097, in good agreement with the BBN result, Y{sub p} = 0.2485 ± 0.0002, based on the Planck determination of the baryon density. In the future, a better understanding of why a large fraction of spectra are not well fit by the model will be crucial to achieving an increase in the precision of the primordial helium abundance determination.

  5. Black carbon and fine particle emissions in Finnish residential wood combustion: Emission projections, reduction measures and the impact of combustion practices

    Science.gov (United States)

    Savolahti, Mikko; Karvosenoja, Niko; Tissari, Jarkko; Kupiainen, Kaarle; Sippula, Olli; Jokiniemi, Jorma

    2016-09-01

    Residential wood combustion (RWC) is a major source of black carbon (BC) and PM2.5 emissions in Finland. Making a robust assessment of emissions on a national level is a challenge due to the varying heater technologies and the effect of users' combustion practices. In this paper we present an update of the emission calculation scheme for Finnish RWC, including technology-specific emission factors based on national measurements. Furthermore, we introduce a transparent method to assess the impact of poor combustion practices on emissions. Using a Finnish emission model, we assessed the emissions in 2000, 2010 and 2030, as well as the cost-efficiency of potential emission reduction measures. The results show that RWC is the biggest source of both PM2.5 and BC emissions in Finland, accounting for 37% and 55% of the total respective emissions. It will also remain the biggest source in the future, and it's role may become even more pronounced if wood consumption continues to increase. Sauna stoves cause the most emissions and also show the biggest potential for emission reductions. Informational campaigns targeted to improve heater users' combustion practices appear as a highly cost-efficient measure, although their impact on country-level emissions was estimated to be relatively limited.

  6. Environmental contamination due to shale gas development.

    Science.gov (United States)

    Annevelink, M P J A; Meesters, J A J; Hendriks, A J

    2016-04-15

    Shale gas development potentially contaminates both air and water compartments. To assist in governmental decision-making on future explorations, we reviewed scattered information on activities, emissions and concentrations related to shale gas development. We compared concentrations from monitoring programmes to quality standards as a first indication of environmental risks. Emissions could not be estimated accurately because of incomparable and insufficient data. Air and water concentrations range widely. Poor wastewater treatment posed the highest risk with concentrations exceeding both Natural Background Values (NBVs) by a factor 1000-10,000 and Lowest Quality Standards (LQSs) by a factor 10-100. Concentrations of salts, metals, volatile organic compounds (VOCs) and hydrocarbons exceeded aquatic ecotoxicological water standards. Future research must focus on measuring aerial and aquatic emissions of toxic chemicals, generalisation of experimental setups and measurement technics and further human and ecological risk assessment.

  7. Supercollision cooling effects on the hot photoluminescence emission of graphene.

    Science.gov (United States)

    Alencar, Thonimar V; Malard, Leandro M; Paula, Ana M de

    2016-09-30

    We report on hot photoluminescence measurements that show the effects of acoustic phonon supercollision processes in the intensity of graphene light emission. We use a simple optical method to induce defects on single layer graphene in a controlled manner to study in detail the light emission dependence on the sample defect density. It is now well accepted that the graphene photoluminescence is due to black-body thermal emission from the quasi-equilibrium electrons at a temperature well above the lattice temperature. Our results show that as the sample defect density is increased the electrons relax energy more efficiently via acoustic phonon supercollision processes leading to lower electron temperatures and thus lower emission intensities. The calculated intensity decrease due to supercollision energy relaxation agrees well with the experimental data.

  8. Sediment trapping by dams creates methane emission hot spots

    DEFF Research Database (Denmark)

    Maeck, A.; Delsontro, T.; McGinnis, Daniel F.

    2013-01-01

    Inland waters transport and transform substantial amounts of carbon and account for similar to 18% of global methane emissions. Large reservoirs with higher areal methane release rates than natural waters contribute significantly to freshwater emissions. However, there are millions of small dams...... worldwide that receive and trap high loads of organic carbon and can therefore potentially emit significant amounts of methane to the atmosphere. We evaluated the effect of damming on methane emissions in a central European impounded river. Direct comparison of riverine and reservoir reaches, where...... sedimentation in the latter is increased due to trapping by dams, revealed that the reservoir reaches are the major source of methane emissions (similar to 0.23 mmol CH4 m(-2) d(-1) vs similar to 19.7 mmol CH4 m(-2) d(-1), respectively) and that areal emission rates far exceed previous estimates for temperate...

  9. Nitrous oxide emissions from rapeseed cultivation in Germany

    Science.gov (United States)

    Fuß, Roland; Andres, Monique; Hegewald, Hannes; Kesenheimer, Katharina; Koebke, Sarah; Räbiger, Thomas; Suárez Quiñones, Teresa; Walter, Katja; Stichnothe, Heinz; Flessa, Heinz

    2016-04-01

    About 12 % of Germany's agricultural area is used for rapeseed cultivation and two third of the harvest is converted to biodiesel. Due to requirements of the EU Renewables Directive the greenhouse gas (GHG) balance of rapeseed cultivation must be reported and sustainability criteria and GHG savings compared to fossil fuel must be achieved and certified. Current certified methodology estimates N2O field emissions from rapeseed cultivation using the IPCC Tier 1 approach based on a global emission factor (N2O emission per unit nitrogen fertilizer input) of 1 %, which is not specific for the crop. We present results from three years of measurements (2013 - 2015) on five field trials in Germany, which combined with data from a meta-analysis suggest that GHG emission factors of German rapeseed cultivation are lower than thought previously. Furthermore, results suggest that substitution of mineral fertilizers with organic fertilizers is a valid mitigation option since it avoids GHG emissions during production of mineral fertilizers.

  10. Probing the radio emission from air showers with polarization measurements

    Science.gov (United States)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bardenet, R.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Foerster, N.; Fox, B. D.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giammarchi, M.; Giller, M.; Gitto, J.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kadija, K.; Kambeitz, O.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; PeÂķala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Pontz, M.; Porcelli, A.; Preda, T.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Straub, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Taşcǎu, O.; Thao, N. T.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Pierre Auger Collaboration

    2014-03-01

    The emission of radio waves from air showers has been attributed to the so-called geomagnetic emission process. At frequencies around 50 MHz this process leads to coherent radiation which can be observed with rather simple setups. The direction of the electric field induced by this emission process depends only on the local magnetic field vector and on the incoming direction of the air shower. We report on measurements of the electric field vector where, in addition to this geomagnetic component, another component has been observed that cannot be described by the geomagnetic emission process. The data provide strong evidence that the other electric field component is polarized radially with respect to the shower axis, in agreement with predictions made by Askaryan who described radio emission from particle showers due to a negative charge excess in the front of the shower. Our results are compared to calculations which include the radiation mechanism induced by this charge-excess process.

  11. Liability rules for international trading of greenhouse gas emissions quotas

    DEFF Research Database (Denmark)

    Haites, E.; Missfeldt, F.

    2001-01-01

    To reduce the costs of mitigating greenhouse gas emissions in accordance with the Kyoto protocol, international trades of emissions quotas are allowed. The revenue from the sale of quotas may exceed the sanctions for non-compliance if these penalties are weak or poorly enforced. Under these circu......To reduce the costs of mitigating greenhouse gas emissions in accordance with the Kyoto protocol, international trades of emissions quotas are allowed. The revenue from the sale of quotas may exceed the sanctions for non-compliance if these penalties are weak or poorly enforced. Under...... these circumstances emissions trading enables a country to benefit financially through non-compliance. To counter non-compliance due to trading a range of liability proposals have been suggested. Using a simple global model, we analyze the economic and environmental performance of these proposals for the first...

  12. On the Limitations of the Anomalous Microwave Emission Emissivity

    Directory of Open Access Journals (Sweden)

    Christopher T. Tibbs

    2012-01-01

    Full Text Available Many studies of anomalous microwave emission (AME have computed an AME emissivity to compare the strength of the AME detected in different regions. Such a value is usually defined as the ratio between the intensity of the AME at 1 cm and the thermal dust emission at 100 μm. However, as studies of Galactic dust emission have shown, the intensity of the thermal dust emission at 100 μm is strongly dependent on the dust temperature, which has severe implications for the AME emissivity defined in this way. In this work, we illustrate and quantify this effect and find that the AME emissivity decreases by a factor of 11.1 between dust temperatures of 20 and 30 K. We, therefore, conclude that computing the AME emissivity relative to the 100 μm emission does not allow for accurate comparisons between the AME observed in different environments. With this in mind, we investigate the use of other tracers of the dust emission with which to compute the AME emissivity and we ultimately conclude that, despite the difficulty in deriving its value, the column density of the dust would be the most suitable quantity with which to compute the AME emissivity.

  13. Far-infrared surface emissivity and climate.

    Science.gov (United States)

    Feldman, Daniel R; Collins, William D; Pincus, Robert; Huang, Xianglei; Chen, Xiuhong

    2014-11-18

    Presently, there are no global measurement constraints on the surface emissivity at wavelengths longer than 15 μm, even though this surface property in this far-IR region has a direct impact on the outgoing longwave radiation (OLR) and infrared cooling rates where the column precipitable water vapor (PWV) is less than 1 mm. Such dry conditions are common for high-altitude and high-latitude locations, with the potential for modeled climate to be impacted by uncertain surface characteristics. This paper explores the sensitivity of instantaneous OLR and cooling rates to changes in far-IR surface emissivity and how this unconstrained property impacts climate model projections. At high latitudes and altitudes, a 0.05 change in emissivity due to mineralogy and snow grain size can cause a 1.8-2.0 W m(-2) difference in the instantaneous clear-sky OLR. A variety of radiative transfer techniques have been used to model the far-IR spectral emissivities of surface types defined by the International Geosphere-Biosphere Program. Incorporating these far-IR surface emissivities into the Representative Concentration Pathway (RCP) 8.5 scenario of the Community Earth System Model leads to discernible changes in the spatial patterns of surface temperature, OLR, and frozen surface extent. The model results differ at high latitudes by as much as 2°K, 10 W m(-2), and 15%, respectively, after only 25 y of integration. Additionally, the calculated difference in far-IR emissivity between ocean and sea ice of between 0.1 and 0.2, suggests the potential for a far-IR positive feedback for polar climate change.

  14. Nitrogen Emission and Deposition: The European Perspective

    Directory of Open Access Journals (Sweden)

    Jan Willem Erisman

    2001-01-01

    Full Text Available Europe has been successful in reducing the emissions of several nitrogenous pollutants over recent decades. This is reflected in concentrations and deposition rates that have decreased for several components. Emissions of nitrogen containing gases are estimated to have decreased in Europe by 10%, 21%, and 14% for NO, NOx, and NH3, respectively, between 1990 and 1998. The main reductions are the result of a decrease in industrial and agricultural activities in the east of Europe as a result of the economic situation, measures in the transport sector, industry and agricultural sector, with only a small part of the reduction due to specific measures designed to reduce emissions. The reduction is significant, but far from the end goal for large areas in Europe in relation to different environmental problems. The Gothenburg Protocol will lead to reductions of 50 and 12% in 2010 relative to 1990 for NOx and NH3, respectively. The N2O emissions are expected to grow between 1998 and 2010 by 9%. Further reductions are necessary to reach critical limits for ecosystem protection, air quality standards and climate change. Emissions of nitrogen compounds result from an overload of reactive nitrogen, which is produced by combustion processes, by synthesis of ammonia or by import from other areas as concentrated animal feeds. Although some improvements can be made by improving the efficiency of combustion processes and agricultural systems, measures to reduce emissions substantially need to be focused on decreasing the production or import of reactive N. Reactive N ceilings for regions based on critical limits for all N-related effects can help to focus such measures. An integrated approach might have advantages over the pollutant specific approach to combat nitrogen pollution. This could provide the future direction for European policy to reduce the impacts of excess nitrogen.

  15. Phenomenology of magnetospheric radio emissions

    Science.gov (United States)

    Carr, T. D.; Desch, M. D.; Alexander, J. K.

    1983-01-01

    Jupiter has now been observed over 24 octaves of the radio spectrum, from about 0.01 MHz to 300,000 MHz. Its radio emissions fill the entire spectral region where interplanetary electromagnetic propagation is possible at wavelengths longer than infrared. Three distinct types of radiation are responsible for this radio spectrum. Thermal emission from the atmosphere accounts for virtually all the radiation at the high frequency end. Synchrotron emission from the trapped high-energy particle belt deep within the inner magnetosphere is the dominant spectral component from about 4000 to 40 MHz. The third class of radiation consists of several distinct components of sporadic low frequency emission below 40 MHz. The decimeter wavelength emission is considered, taking into account the discovery of synchrotron emission, radiation by high-energy electrons in a magnetic field, and the present status of Jovian synchrotron phenomenology. Attention is also given to the decameter and hectometer wavelength emission, and emissions at kilometric wavelengths.

  16. Carbon emission flow in networks

    National Research Council Canada - National Science Library

    Kang, Chongqing; Zhou, Tianrui; Chen, Qixin; Xu, Qianyao; Xia, Qing; Ji, Zhen

    2012-01-01

    As the human population increases and production expands, energy demand and anthropogenic carbon emission rates have been growing rapidly, and the need to decrease carbon emission levels has drawn increasing attention...

  17. Danish emission inventories for agriculture

    DEFF Research Database (Denmark)

    Mikkelsen, Mette Hjorth; Albrektsen, Rikke; Gyldenkærne, Steen

    . This report contains a description of the emissions from the agricultural sector from 1985 to 2009. Furthermore, the report includes a detailed description of methods and data used to calculate the emissions, which is based on national methodologies as well as international guidelines. For the Danish...... emissions calculations and data management an Integrated Database model for Agricultural emissions (IDA) is used. The emission from the agricultural sector includes emission of the greenhouse gases methane (CH4), nitrous oxide (N2O), ammonia (NH3), particulate matter (PM), non-methane volatile organic...... compounds (NMVOC) and other pollutants related to the field burning of agricultural residue such as NOx, CO2, CO, SO2, heavy metals, dioxin and PAH. The ammonia emission from 1985 to 2009 has decreased from 119 300 tonnes of NH3 to 73 800 tonnes NH3, corresponding to a 38 % reduction. The emission...

  18. Bichromatic emission and multimode dynamics in bidirectional ring lasers

    Science.gov (United States)

    Pérez-Serrano, Antonio; Javaloyes, Julien; Balle, Salvador

    2010-04-01

    The multimode dynamics of a two-level ring laser is explored numerically using a bidirectional traveling wave model retaining the spatial effects due to the presence of counter-propagating electric fields in the population inversion. Dynamical regimes where the emission in each direction occurs at different wavelengths are studied. Mode-locked unidirectional emission for large gain bandwidth and relatively small detuning is reported.

  19. A Two-stage Polynomial Method for Spectrum Emissivity Modeling

    OpenAIRE

    Qiu, Qirong; Liu, Shi; Teng, Jing; Yan, Yong

    2015-01-01

    Spectral emissivity is a key in the temperature measurement by radiation methods, but not easy to determine in a combustion environment, due to the interrelated influence of temperature and wave length of the radiation. In multi-wavelength radiation thermometry, knowing the spectral emissivity of the material is a prerequisite. However in many circumstances such a property is a complex function of temperature and wavelength and reliable models are yet to be sought. In this study, a two stages...

  20. Vehicle emission factors of solid nanoparticles in the laboratory and on the road using Portable Emission Measurement Systems (PEMS

    Directory of Open Access Journals (Sweden)

    Barouch eGiechaskiel

    2015-12-01

    due to the different DPF fill state and passive regeneration during the tests. The findings of this study can (i help improving the on SPN emissions and (ii assist policy makers in designing effective test procedures for measuring SPN emissions of vehicles under real-world driving conditions.

  1. Emission factors for passenger cars: application of instantaneous emission modeling

    Science.gov (United States)

    de Haan, Peter; Keller, Mario

    This paper discusses the use of 'instantaneous' high-resolution (1 Hz) emission data for the estimation of passenger car emissions during real-world driving. Extensive measurements of 20 EURO-I gasoline passenger cars have been used to predict emission factors for standard (i.e. legislative) as well as non-standard (i.e. real-world) driving patterns. It is shown that emission level predictions based upon chassis dynamometer tests over standard driving cycles significantly underestimate emission levels during real-world driving. The emission characteristics of modern passenger cars equipped with a three-way catalytic converter are a low, basic emission level on the one hand, and frequent emission 'peaks' on the other. For real-world driving, up to one-half of the entire emission can be emitted during these short-lasting peaks. Their frequency depends on various factors, including the level of 'dynamics' (speed variation) of the driving pattern. Because of this, the use of average speed as the only parameter to characterize emissions over a specific driving pattern is not sufficient. The instantaneous emissions approach uses an additional parameter representing engine load in order to resolve the differences between driving patterns with comparable average speeds but different levels of 'dynamics'. The paper includes an investigation of different statistical indicators and discusses methods to further improve the prediction capability of the instantaneous emission approach. The fundamental differences in emission-reduction strategies between different car manufacturers make the task of constructing a model valid for all catalyst passenger cars seemingly impossible, if the model is required to predict both fleet-averaged emission levels and emission factors for driving patterns of short duration for individual vehicles simultaneously.

  2. Future Emissions from Railway Traffic

    DEFF Research Database (Denmark)

    Sorenson, Spencer C.

    1998-01-01

    In investigation of the expected development in factors which influence railway energy consumption and emissions. Traffic factors such as train speed, load, an occupancy were considered. Tehcnical factors such an emissions factors, fleet composition and train weight were also considered. An estim......In investigation of the expected development in factors which influence railway energy consumption and emissions. Traffic factors such as train speed, load, an occupancy were considered. Tehcnical factors such an emissions factors, fleet composition and train weight were also considered...

  3. Danish emission inventories for stationary combustion plants. Inventories until year 2004

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Ole-Kenneth; Nielsen, Malene; Boll Illerup, J.

    2007-04-15

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOX, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins and PAH. A considerable decrease of the SO2, NOX and heavy metal emissions is mainly a result of decreased emissions from large power plants and waste incineration plants. The emission of CH4 has increased due to increased use of lean-burn gas engines in CHP plants. The emission of PAH increased as a result of the increased combustion of wood in residential boilers and stoves. The dioxin emission decreased due to flue gas cleaning on waste incineration plants. Uncertainties for the emissions and trends have been estimated. (au)

  4. ACOUSTIC EMISSION ANALYZER

    Directory of Open Access Journals (Sweden)

    J. J. Almeida-Pérez

    2004-12-01

    Full Text Available In this paper appears a solution for acoustic emission analysis commonly known as noise. For the accomplishmentof this work a personal computer is used, besides sensors (microphones and boards designed and built for signalconditioning. These components are part of a virtual instrument used for monitoring the acoustical emission. Themain goal of this work is to develop a virtual instrument that supplies many important data as the result of ananalysis allowing to have information in an easy and friendly way. Moreover this information is very useful forstudying and resolving several situations in planning, production and testing areas.The main characteristics of the virtual instrument are: signal analysis in time, effective power measurement inDecibels (dB, average intensity taken from the principle of paired microphones, as well as the data analysis infrequency. These characteristics are included to handle two information channels.

  5. When you pass your due date

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000515.htm When you pass your due date To use the sharing features ... link between you and your baby. As you pass your due date, the placenta may not work ...

  6. Photoacoustic emission from fluorescent nanodiamonds enhanced with gold nanoparticles.

    Science.gov (United States)

    Zhang, Bailin; Fang, Chia-Yi; Chang, Cheng-Chun; Peterson, Ralph; Maswadi, Saher; Glickman, Randolph D; Chang, Huan-Cheng; Ye, Jing Yong

    2012-07-01

    Fluorescent nanodiamonds (FNDs) have drawn much attention in recent years for biomedical imaging applications due to their desired physical properties including excellent photostability, high biocompatibility, extended far-red fluorescence emission, and ease of surface functionalization. Here we explore a new feature of FNDs, i.e. their photoacoustic emission capability, which may lead to potential applications of using FNDs as a dual imaging contrast agent for combined fluorescence and photoacoustic imaging modalities. We observed significant enhancement of photoacoustic emission from FNDs when they were conjugated with gold nanoparticles (GNPs).

  7. Acoustic emission source modeling

    Directory of Open Access Journals (Sweden)

    Hora P.

    2010-07-01

    Full Text Available The paper deals with the acoustic emission (AE source modeling by means of FEM system COMSOL Multiphysics. The following types of sources are used: the spatially concentrated force and the double forces (dipole. The pulse excitation is studied in both cases. As a material is used steel. The computed displacements are compared with the exact analytical solution of point sources under consideration.

  8. Emissivity modulating electrochromic device

    Science.gov (United States)

    Demiryont, Hulya; Shannon, Kenneth C., III; Sheets, Judd

    2009-05-01

    The IR-ECDTM (Infra-Red ElectroChromic Device) variable emitance device (VED) is an all-solid-state monolithic vacuum deposited thin film system with a unique metamaterial IR transparent-electrode system which functions as an electrically controlled dimmable mirror in the IR region. The maximum reflectance corresponding to the bleached condition of the system is around 90% (low-e condition, e=0.1). The minimum reflectance reaches nearly zero in the colored condition of the system (high emittance, e=1). The average emissivity modulation of the IRECDTM is 0.7 in the 8-12 micron region, and at 9.7 micron (room temperature) it reaches a value of 0.9. Half and full emissivity modulations occur within 2 and10 minutes respectively. Because of its light weight (5g/m2), low voltage requirement (+/- 1 Volts), extremely good emissivity control properties (from 0 to 0.9 at 300K) and highly repeatable deposition process, the IR-ECDTM technology is very attractive for satellite thermal control applications. The IR-ECDTM has been under evaluation in a real space environment since March 8, 2007. This paper presents recent achievements of the IR-ECDTM including space test results.

  9. 34 CFR 602.25 - Due process.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Due process. 602.25 Section 602.25 Education... Required Operating Policies and Procedures § 602.25 Due process. The agency must demonstrate that the procedures it uses throughout the accrediting process satisfy due process. The agency meets this...

  10. Do all Flares have White Light Emission?

    CERN Document Server

    Jess, D B; Crockett, P J; Keenan, F P

    2008-01-01

    High-cadence, multiwavelength optical observations of a solar active region (NOAA 10969), obtained with the Swedish Solar Telescope, are presented. Difference imaging of white light continuum data reveals a white light brightening, 2 min in duration, linked to a co-temporal and co-spatial C2.0 flare event. The flare kernel observed in the white light images has a diameter of 300 km, thus rendering it below the resolution limit of most space-based telescopes. Continuum emission is present only during the impulsive stage of the flare, with the effects of chromospheric emission subsequently delayed by approximately 2 min. The localized flare emission peaks at 300% above the quiescent flux. This large, yet tightly confined, increase in emission is only resolvable due to the high spatial resolution of the Swedish Solar Telescope. An investigation of the line-of-sight magnetic field derived from simultaneous MDI data shows that the continuum brightening is located very close to a magnetic polarity inversion line. A...

  11. Electron Cyclotron Emission from Nonthermal Distributions

    Science.gov (United States)

    Harvey, R. W.; Coda, S.; Taylor, G.; Austin, M. E.; Prater, R.

    2005-10-01

    The GENRAY ray tracing code incorporates a solution of the RF energy transport equation (emission and absorption along WKB rays) including the effects of nonthermal electron distribution functions. Distributions are from self-consistent RF solutions of the bounce-averaged Fokker-Planck equation using the CQL3D 2V-1R code. We present computed spectra for two experimental situations: (1) EBW emission from electron distributions in NSTX due to future EBWCD experiments. In this case, the calculated transport of the EBW emission from overdense (omega/pe > omega/ce) NSTX plasma to the plasma edge accounts for the effects of BXO mode conversion whereby EBW waves transform to X-mode, then O-mode near the omega/pe=1 surface; and (2) EC emission in present low density DIII-D ECH experiments. A 27 keV central ECE temperature is calculated, in close agreement with the experimental value, for a plasma with 6.5 keV Thomson scattering temperature. Acknowledgment: USDOE Grants DE-AC03-99ER54463 and DE-FG03-02ER54684, and CRPP-EPFL.

  12. Emission inventory for fugitive emissions from fuel in Denmark

    DEFF Research Database (Denmark)

    Plejdrup, Marlene Schmidt; Nielsen, Ole-Kenneth; Nielsen, Malene

    This report presents the methodology and data used in the Danish inventory of fugitive emissions from fuels for the years until 2013. The inventory of fugitive emissions includes CO2, CH4, N2O, SO2, NOx, NMVOC, CO, particulate matter, Black carbon, heavy metals, dioxin and PAHs. In 2013 the total...... Danish emission of greenhouse gasses was 54 584 Gg CO2 equivalents. Fugitive emissions from fuels account for 387 Gg CO2 equivalents or approximately 1 %. The major part of the fugitive emissions are emitted as CO2 (61 %) mainly from flaring in upstream oil and gas production. The major source...... of fugitive CH4 emission is production of oil and gas in the North Sea, refining of oil and loading of oil onto ships both offshore and onshore. The fugitive emissions of NMVOC originate for the major part from oil and gas production, loading of ships, transmission and distribution of oil, and to a less...

  13. Emission inventory for fugitive emissions from fuel in Denmark

    DEFF Research Database (Denmark)

    Plejdrup, Marlene Schmidt; Nielsen, Ole-Kenneth; Nielsen, Malene

    This report presents the methodology and data used in the Danish inventory of fugitive emissions from fuels for the years until 2013. The inventory of fugitive emissions includes CO2, CH4, N2O, SO2, NOx, NMVOC, CO, particulate matter, Black carbon, heavy metals, dioxin and PAHs. In 2013 the total...... Danish emission of greenhouse gasses was 54 584 Gg CO2 equivalents. Fugitive emissions from fuels account for 387 Gg CO2 equivalents or approximately 1 %. The major part of the fugitive emissions are emitted as CO2 (61 %) mainly from flaring in upstream oil and gas production. The major source...... of fugitive CH4 emission is production of oil and gas in the North Sea, refining of oil and loading of oil onto ships both offshore and onshore. The fugitive emissions of NMVOC originate for the major part from oil and gas production, loading of ships, transmission and distribution of oil, and to a less...

  14. Impact of urban emission on air-quality over central Europe: present day and future emissions perspective

    Science.gov (United States)

    Huszar, Peter; Belda, Michal; Halenka, Tomas; Karlicky, Jan

    2016-04-01

    The purpose of the study is to quantify the impact of present-day and future urban emission from central European cities on the regional air-quality (AQ), based on a modeling couple of the regional climate model RegCM4.2 and the chemistry transport model CAMx, including two-way interactions. A series of simulations was carried out for the present (2001-2010) decade and two future decades (2026-2035 and 2046-2055) either with all urban emissions included (base case) or without considering urban emissions. As we are interested on the impact of emission changes only, the impact of different driving meteorological conditions in the future (due to climate change) are not considered. The emissions used is the TNO MEGAPOLI European emission database that includes country/sector based scenarios for years 2030 and 2050, which were used for the encompassing decades. Further, the sensitivity of ozone production to urban emissions was examined by performing reduction experiments with -20% emission perturbation of NOx and/or NMVOC. The model was also validated using surface measurements of key pollutants. Selected air-quality measures were used as metrics describing the cities emission impact on regional air pollution. Due to urban emissions, significant ozone titration occurs over cities while over rural areas further from, ozone production is modeled, mainly in terms of number of exceedances and accumulated exceedances over the threshold of 40 ppbv. Urban NOx, SO2 and PM2.5 emissions also significantly contribute to concentrations in the cities themselves (up to 50-70% for NOx and SO2 , and up to 55% for PM2.5), but the contribution is large over rural areas as well (10-20%). Although air pollution over cities is largely determined by the local urban emissions, considerable (often a few tens of %) fraction of the concentration is attributable to other sources from rural areas and minor cities. The future urban emission AQ fingerprint is, in general, slightly smaller than in

  15. Global time trends in PAH emissions from motor vehicles

    Science.gov (United States)

    Shen, Huizhong; Tao, Shu; Wang, Rong; Wang, Bin; Shen, Guofeng; Li, Wei; Su, Shenshen; Huang, Ye; Wang, Xilong; Liu, Wenxin; Li, Bengang; Sun, Kang

    2011-04-01

    Emission from motor vehicles is the most important source of polycyclic aromatic hydrocarbons (PAHs) in urban areas. Emission factors of individual PAHs for motor vehicles reported in the literature varied 4 to 5 orders of magnitude, leading to high uncertainty in emission inventory. In this study, key factors affecting emission factors of PAHs (EF PAH) for motor vehicles were evaluated quantitatively based on thousands of EF PAH measured in 16 countries for over 50 years. The result was used to develop a global emission inventory of PAHs from motor vehicles. It was found that country and vehicle model year are the most important factors affecting EF PAH, which can be quantified using a monovariate regression model with per capita gross domestic production (purchasing power parity) as a sole independent variable. On average, 29% of variation in log-transformed EF PAH could be explained by the model, which was equivalent to 90% reduction in overall uncertainty on arithmetic scale. The model was used to predict EF PAH and subsequently PAH emissions from motor vehicles for various countries in the world during a period from 1971 to 2030. It was estimated that the global emission reached its peak value of approximate 101 Gg in 1978 and decreased afterwards due to emission control in developed countries. The annual emission picked up again since 1990 owing to accelerated energy consumption in China and other developing countries. With more and more rigid control measures taken in the developing world, global emission of PAHs is currently passing its second peak. It was predicted that the emission would decrease from 77 Gg in 2010 to 42 Gg in 2030.

  16. Spectroscopic Confirmation of Three z-Dropout Galaxies at z = 6.844 - 7.213: Lyman Alpha Demography of z ~ 7 Galaxies

    CERN Document Server

    Ono, Yoshiaki; Mobasher, Bahram; Dickinson, Mark; Penner, Kyle; Shimasaku, Kazuhiro; Weiner, Benjamin J; Kartaltepe, Jeyhan S; Nakajima, Kimihiko; Nayyeri, Hooshang; Stern, Daniel; Kashikawa, Nobunari; Spinrad, Hyron

    2011-01-01

    We present the results of our ultra-deep Keck/DEIMOS spectroscopy of z-dropout galaxies in the SDF and GOODS-N. For 3 out of 11 objects, we detect an emission line at ~ 1um with a signal-to-noise ratio of ~ 10. The lines show asymmetric profiles with high weighted skewness values, consistent with being Lya, yielding redshifts of z=7.213, 6.965, and 6.844. Specifically, we confirm the z=7.213 object in two independent DEIMOS runs with different spectroscopic configurations. The z=6.965 object is a known Lya emitter, IOK-1, for which our improved spectrum at a higher resolution yields a robust skewness measurement. The three z-dropouts have Lya fluxes of 3 x 10^-17 erg s^-1 cm^-2 and rest-frame equivalent widths EW_0^Lya = 33-43A. Based on the largest spectroscopy sample of 43 z-dropouts that is the combination of our and previous data, we find that the fraction of Lya-emitting galaxies (EW_0^Lya > 25A) is low at z ~ 7; 17 +- 10% and 24 +- 12% for bright (Muv ~= -21) and faint (Muv ~= -19.5) galaxies, respectiv...

  17. Sequim Site Radionuclide Air Emissions Report for Calendar Year 2012

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Sandra F.; Barnett, J. Matthew; Gervais, Todd L.

    2013-04-01

    This report is prepared to document compliance with the Code of Federal Regulations (CFR), Title 40, Protection of the Environment, Part 61, National Emission Standards for Hazardous Air Pollutants (NESHAP), Subpart H, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities and ashington Administrative Code (WAC) Chapter 246-247, Radiation Protection Air Emissions. This report meets the calendar year 2012 Sequim Site annual reporting requirement for its operations as a privately-owned facility as well as its federally-contracted status that began in October 2012. Compliance is indicated by comparing the estimated dose to the maximally exposed individual (MEI) with the 10 mrem/yr Environmental Protection Agency (EPA) standard. The MSL contains only sources classified as fugitive emissions. Despite the fact that the regulations are intended for application to point source emissions, fugitive emissions are included with regard to complying with the EPA standard. The dose to the Sequim Site MEI due to routine operations in 2012 was 9E-06 mrem (9E-08 mSv). No non-routine emissions occurred in 2012. The MSL is in compliance with the federal and state 10 mrem/yr standard.

  18. Methane emissions from grasslands.

    NARCIS (Netherlands)

    Pol-van Dasselaar, van den A.

    1998-01-01

    IntroductionMethane (CH 4 ) is an important greenhouse gas. The concentration of greenhouse gases in the atmosphere has been increasing since pre-industrial times, mainly due to human activities. This increase gives concern, because it may cause global warming due to an enhanced greenhous

  19. A novel field emission microscopy method to study field emission characteristics of freestanding carbon nanotube arrays

    Science.gov (United States)

    Li, Yunhan; Sun, Yonghai; Jaffray, David A.; Yeow, John T. W.

    2017-04-01

    Field emission (FE) uniformity and the mechanism of emitter failure of freestanding carbon nanotube (CNT) arrays have not been well studied due to the difficulty of observing and quantifying FE performance of each emitter in CNT arrays. Herein a field emission microscopy (FEM) method based on poly(methyl methacrylate) (PMMA) thin film is proposed to study the FE uniformity and CNT emitter failure of freestanding CNT arrays. FE uniformity of freestanding CNT arrays and different levels of FE current contributions from each emitter in the arrays are recorded and visualized. FEM patterns on the PMMA thin film contain the details of the CNT emitter tip shape and whether multiple CNT emitters occur at an emission site. Observation of real-time FE performance and the CNT emitter failure process in freestanding CNT arrays are successfully achieved using a microscopic camera. High emission currents through CNT emitters causes Joule heating and light emission followed by an explosion of the CNTs. The proposed approach is capable of resolving the major challenge of building the relationship between FE performance and CNT morphologies, which can significantly facilitate the study of FE non-uniformity, the emitter failure mechanism and the development of stable and reliable FE devices in practical applications.

  20. Microwave Emission from Aligned Dust

    CERN Document Server

    Lazarian, A

    2003-01-01

    Polarized microwave emission from dust is an important foreground that may contaminate polarized CMB studies unless carefully accounted for. We discuss potential difficulties associated with this foreground, namely, the existence of different grain populations with very different emission/polarization properties and variations of the polarization yield with grain temperature. In particular, we discuss observational evidence in favor of rotational emission from tiny PAH particles with dipole moments, i.e. ``spinning dust'', and also consider magneto-dipole emission from strongly magnetized grains. We argue that in terms of polarization, the magneto-dipole emission may dominate even if its contribution to total emissivity is subdominant. Addressing polarized emission at frequencies larger than approsimately 100 GHz, we discuss the complications arising from the existence of dust components with different temperatures and possibly different alignment properties.

  1. Danish emission inventories for agriculture

    DEFF Research Database (Denmark)

    Mikkelsen, Mette Hjorth; Albrektsen, Rikke; Gyldenkærne, Steen

    compounds (NMVOC) and other pollutants related to the field burning of agricultural residue such as NOx, CO2, CO, SO2, heavy metals, dioxin and PAH. The ammonia emission from 1985 to 2009 has decreased from 119 300 tonnes of NH3 to 73 800 tonnes NH3, corresponding to a 38 % reduction. The emission...... emissions calculations and data management an Integrated Database model for Agricultural emissions (IDA) is used. The emission from the agricultural sector includes emission of the greenhouse gases methane (CH4), nitrous oxide (N2O), ammonia (NH3), particulate matter (PM), non-methane volatile organic...... of greenhouse gases has decreased by 25 % from 12.9 M tonnes CO2 equivalents to 9.6 M tonnes CO2 equivalents from 1985 to 2009. Improvements in feed efficiency and utilisation of nitrogen in livestock manure are the most important reasons for the reduction of both the ammonia and greenhouse gas emissions...

  2. Improving Emission Estimates With The Community Emissions Data System (CEDS

    Science.gov (United States)

    Smith, S.; Hoesly, R. M.

    2016-12-01

    Inventory data is a key component of scientific and regulatory efforts focused on air pollution, climate and global change and also a critical compliment for observational emission efforts. The Community Emissions Data System (CEDS) project aims to provide consistent estimates of historical anthropogenic emissions using an open-source data system. The first product from this system was anthropogenic emissions over 1750-2014 of reactive gases, aerosols, and carbon dioxide, for use in CMIP6. These data are annually resolved, have monthly seasonality, were estimated at a moderately detailed level of 50+ sectors and 8 fuel types, and were mapped to spatial grids. CEDS combines bottom-up default emissions estimates that are calibrated to country-level inventories where these are deemed reliable. Outside of years where inventories are available, driver data and emission factors are extended using user-defined rules. The system is designed to facilitate annual updates (so the most recent inventory data is available). The software and most input data are being released as open source software in order to provide access to assumptions, improve emission estimates, and allow access to fundamental emissions data for research purposes. We report on our efforts to expand the spatial resolution by estimating emission trends by state/province for large countries. This will allow spatial shifts in emissions over time to be better represented and make the data more useful for research such as that discussed in this session. As part of these improvements we will add support for use of regionally-specific emission proxies and point sources. A key focus of ongoing research is better quantification of emissions uncertainty. Our goal is consistent estimation of uncertainty over time, sector, and country. We will also report on results estimating the additional uncertainty associated with extending emissions data over recent years. http://www.globalchange.umd.edu/CEDS/

  3. EFFECTS OF ETHANOL BLENDED DIESEL FUEL ON EXHAUST EMISSIONS FROM A DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    Özer CAN

    2005-02-01

    Full Text Available Diesel engine emissions can be improved by adding organic oxygenated compounds to the No. 2 diesel fuel. In this study, effects of 10 % and 15 % (in volume ethanol addition to Diesel No. 2 on exhaust emissions from an indirect injection turbocharged diesel engine running at different engine speeds and loads were investigated. Experimental results showed that the ethanol addition reduced CO, soot and SO2 emissions, although it caused some increase in NOx emission and some power reductions due to lower heating value of ethanol. Improvements on emissions were more significant at full load rather than at partial loads.

  4. Multi-neutron emission of Cd isotopes

    CERN Document Server

    Severyukhin, A P; Borzov, I N; Sushenok, E O

    2016-01-01

    An influence of the phonon-phonon coupling (PPC) on the $\\beta$-decay half-lives and multi-neutron emission probabilities is analysed within the microscopic model based on the Skyrme interaction with tensor components included. The finite-rank separable approximation is used in order to handle large two-quasiparticle spaces. The even-even nuclei near the r-process pathes at $N=82$ are studied. The characteristics of ground states, $2^+$ excitations and $\\beta$-decay strength of the neutron-rich Cd isotopes are treated in detail. It is shown that a strong redistribution of the Gamow-Teller strength due to the PPC is mostly sensitive to the multi-neutron emission probability of the Cd isotopes.

  5. Emission of chemical substances from office equipment

    Directory of Open Access Journals (Sweden)

    Joanna Kowalska

    2012-12-01

    Full Text Available A number of potentially harmful pollutants are emitted from office equipment. Printers and copiers are sources of volatile organic compounds (VOC, which at least partly, are generated from the heated toner and paper dust during printing process. Benzene, toluene, ethylbenzene, xylenes, styrene, and formaldehyde were detected in the blended emissions emitted from printing devices. Office printing devices are recognized to be the major sources of indoor fine and ultrafine aerosol particles. The emissions of certain pollutants from office equipment may be at relatively low level compared to other known sources (e.g. building materials. However, office equipment is potentially the important source of human exposure due to the short distance for the people operating them both at home and in the office.

  6. Plasmonic nanoprobes for stimulated emission depletion microscopy

    CERN Document Server

    Cortes, Emiliano; Sinclair, Hugo G; Guldbrand, Stina; Peveler, William J; Davies, Timothy; Parrinello, Simona; Görlitz, Frederik; Dunsby, Chris; Neil, Mark A A; Sivan, Yonatan; Parkin, Ivan P; French, Paul M; Maier, Stefan A

    2016-01-01

    Plasmonic nanoparticles influence the absorption and emission processes of nearby emitters due to local enhancements of the illuminating radiation and the photonic density of states. Here, we use the plasmon resonance of metal nanoparticles in order to enhance the stimulated depletion of excited molecules for super-resolved microscopy. We demonstrate stimulated emission depletion (STED) microscopy with gold nanorods with a long axis of only 26 nm and a width of 8 nm that provide an enhancement of the resolution compared to fluorescent-only probes without plasmonic components irradiated with the same depletion power. These novel nanoparticle-assisted STED probes represent a ~2x10^3 reduction in probe volume compared to previously used nanoparticles and we demonstrate their application to the first plasmon-assisted STED cellular imaging. We also discuss their current limitations.

  7. Modeling study of natural emissions, source apportionment, and emission control of atmospheric mercury

    Science.gov (United States)

    Shetty, Suraj K.

    ) and CAMNet (Canadian Atmospheric Mercury Measurement Network). The model estimated a total deposition of 474 Mg yr-1 to the CONUS (Contiguous United States) domain, with two-thirds being dry deposited. Reactive gaseous mercury contributed the most to 60% of deposition. Emission speciation distribution is a key factor for local deposition as contribution from large point sources can be as high as 75% near (lead to advancement in state-of-the-art control technologies that alleviate the impact of mercury on ecosystem and human health. This part of the work applies a sorption model to simulate adsorption of mercury in flue gases, onto a confined-bed of activated carbon. The model's performances were studied at various flue gas flow rates, inlet mercury concentrations and adsorption bed temperatures. The process simulated a flue gas, with inlet mercury concentration of 300 ppb, entering at a velocity of 0.3 m s-1 from the bottom into a fixed bed (inside bed diameter of 1 m and 3 m bed height; bed temperature of 25 °C) of activated carbon (particle size of 0.004 m with density of 0.5 g cm-3 and surface area of 90.25 cm2 g -1). The model result demonstrated that a batch of activated carbon bed was capable of controlling mercury emission for approximately 275 days after which further mercury uptake starts to decrease till it reaches about 500 days when additional control ceases. An increase in bed temperature significantly reduces mercury sorption capacity of the activated carbon. Increase in flue gas flow rate may result in faster consumption of sorption capacity initially but at a later stage, the sorption rate decreases due to reduced sorption capacity. Thus, overall sorption rate remains unaffected. The activated carbon's effective life (time to reach saturation) is not affected by inlet mercury concentration, implying that the designing and operation of a mercury sorption process can be done independently. The results provide quantitative indication for designing

  8. Positron Emission Tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

  9. Positron emission tomography

    CERN Document Server

    Paans, A M J

    2006-01-01

    Positron Emission Tomography (PET) is a method for measuring biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labelled with positron emitting radionuclides such as 11C, 13N, 15O and 18F and by measuring the annihilation radiation using a coincidence technique. This includes also the measurement of the pharmacokinetics of labelled drugs and the measurement of the effects of drugs on metabolism. Also deviations of normal metabolism can be measured and insight into biological processes responsible for diseases can be obtained. At present the combined PET/CT scanner is the most frequently used scanner for whole-body scanning in the field of oncology.

  10. Emission rate measuring device

    Science.gov (United States)

    Luckat, S.

    1980-09-01

    The development and application of an emission rate measuring device for gaseous components is explored. The device contains absorption fluid from a supply container that moistens a cylindrical paper sleeve. A newer model is provided with a direct current motor requiring less electricity than an older model. The hose pump is modified to avoid changing it and the filter sleeve is fastened more securely to the distributor head. Application of the measuring devices is discussed, particularly at the Cologne Cathedral, where damage to the stone is observed.

  11. Positron Emission Tomography (PET)

    Science.gov (United States)

    Welch, M. J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

  12. Evaluation of mobile emissions contributions to Mexico City's emissions inventory using on-road and cross-road emission measurements and ambient data

    Directory of Open Access Journals (Sweden)

    M. Zavala

    2009-03-01

    /NOx ratio has decreased at a rate of about 1.9 ppm/ppm/year over the last two decades and that the decrease has been driven by reductions in CO levels rather than by NOx concentration changes, suggesting that the relative contribution of diesel vehicles to overall NOx levels has increased over time in the city. Despite the impressive increases in the size of the vehicle fleet between 2000 and 2006, the early morning ambient concentrations of CO and NOx have not increased accordingly, probably due to the reported low removal rates of older vehicles, which do not have emissions control technologies, and partially due to the much lower emissions from newer gasoline vehicles. This indicates that an emission-based air quality control strategy targeting large reductions of emissions from mobile sources should be directed towards a significant increase of the removal rate of older, highly-polluting, vehicles.

  13. Pre-Harvest Sugarcane Burning: Determination of emission factors through laboratory measurements and quantification of emissions

    Science.gov (United States)

    de Azeredo Franca, D.; Maria Longo, K.; Gomes Soares Neto, T.; Carlos dos Santos, J.; Rudorf, B. F.; Alves de Aguiar, D.; Freitas, S.; Vieira Cortez, E.; Stockler S. Lima, R.; S. Gacita, M.; Anselmo, E.; A. Carvalho, J., Jr.

    2011-12-01

    Sugarcane is a relevant crop to Brazilian economy and roughly 50% of its production is used to produce ethanol. São Paulo state is the largest producer of sugarcane in Brazil being responsible for almost 60% of its production in a cultivated area of 4.5 Mha in 2010. Sugarcane harvest practice can be performed either with green harvest or with pre-harvest burning. A "Green Ethanol" Protocol is underway to eliminate the pre-harvest burning practice by 2014 in most of the sugarcane cultivated land in São Paulo state. During the last five years close to 2 Mha were annually harvested with the pre-harvest burning practice. This practice emits particulate material, greenhouse gases, and tropospheric ozone precursors to the atmosphere. Even with policies to eliminate the burning practice in the near future there is still a significant environmental damage due to the pre-harvest burning practice of sugarcane. Thus the generation of reliable inventories of emissions due to this activity is crucial in order to assess the environmental impact. Presently the official Brazilian emissions inventories do not include the sugarcane pre-harvest burning contribution. Therefore, this work aims to estimate the annual emissions (from 2006 to 2010) associated with pre-harvest sugarcane burning practice in São Paulo state, including the determination of emission factors for some trace gases and particulate material smaller than 2.5 μm. Annual remote sensing based mappings of burned sugarcane fields throughout the harvest season in each crop year made in the context of Canasat Project (http://www.dsr.inpe.br/laf/canasat/en/) were added to the Brazilian Biomass Burning Emission Model (3BEM) in order to estimate trace gases and aerosols emissions. Two laboratory combustion experiments were carried out to determine the emission factors estimation. Samples of different varieties of sugarcane were harvested in dry weather conditions and in distinct sites in the state of São Paulo to assure

  14. Odor and odorous chemical emissions from animal buildings: part 1 - project overview, collection methods, and quality control

    Science.gov (United States)

    Livestock facilities have historically generated public concerns due to their emissions of odorous air and various chemical pollutants. Odor emission factors and identification of principal odorous chemicals are needed to better understand the problem. Applications of odor emission factors include i...

  15. Urban emissions of water vapor in winter

    Science.gov (United States)

    Salmon, Olivia E.; Shepson, Paul B.; Ren, Xinrong; Marquardt Collow, Allison B.; Miller, Mark A.; Carlton, Annmarie G.; Cambaliza, Maria O. L.; Heimburger, Alexie; Morgan, Kristan L.; Fuentes, Jose D.; Stirm, Brian H.; Grundman, Robert; Dickerson, Russell R.

    2017-09-01

    Elevated water vapor (H2Ov) mole fractions were occasionally observed downwind of Indianapolis, IN, and the Washington, D.C.-Baltimore, MD, area during airborne mass balance experiments conducted during winter months between 2012 and 2015. On days when an urban H2Ov excess signal was observed, H2Ov emission estimates range between 1.6 × 104 and 1.7 × 105 kg s-1 and account for up to 8.4% of the total (background + urban excess) advected flow of atmospheric boundary layer H2Ov from the urban study sites. Estimates of H2Ov emissions from combustion sources and electricity generation facility cooling towers are 1-2 orders of magnitude smaller than the urban H2Ov emission rates estimated from observations. Instances of urban H2Ov enhancement could be a result of differences in snowmelt and evaporation rates within the urban area, due in part to larger wintertime anthropogenic heat flux and land cover differences, relative to surrounding rural areas. More study is needed to understand why the urban H2Ov excess signal is observed on some days, and not others. Radiative transfer modeling indicates that the observed urban enhancements in H2Ov and other greenhouse gas mole fractions contribute only 0.1°C d-1 to the urban heat island at the surface. This integrated warming through the boundary layer is offset by longwave cooling by H2Ov at the top of the boundary layer. While the radiative impacts of urban H2Ov emissions do not meaningfully influence urban heat island intensity, urban H2Ov emissions may have the potential to alter downwind aerosol and cloud properties.

  16. High Efficiency, Low Emission Refrigeration System

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL; Sharma, Vishaldeep [ORNL

    2016-08-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced for

  17. 4D image reconstruction for emission tomography

    Science.gov (United States)

    Reader, Andrew J.; Verhaeghe, Jeroen

    2014-11-01

    An overview of the theory of 4D image reconstruction for emission tomography is given along with a review of the current state of the art, covering both positron emission tomography and single photon emission computed tomography (SPECT). By viewing 4D image reconstruction as a matter of either linear or non-linear parameter estimation for a set of spatiotemporal functions chosen to approximately represent the radiotracer distribution, the areas of so-called ‘fully 4D’ image reconstruction and ‘direct kinetic parameter estimation’ are unified within a common framework. Many choices of linear and non-linear parameterization of these functions are considered (including the important case where the parameters have direct biological meaning), along with a review of the algorithms which are able to estimate these often non-linear parameters from emission tomography data. The other crucial components to image reconstruction (the objective function, the system model and the raw data format) are also covered, but in less detail due to the relatively straightforward extension from their corresponding components in conventional 3D image reconstruction. The key unifying concept is that maximum likelihood or maximum a posteriori (MAP) estimation of either linear or non-linear model parameters can be achieved in image space after carrying out a conventional expectation maximization (EM) update of the dynamic image series, using a Kullback-Leibler distance metric (comparing the modeled image values with the EM image values), to optimize the desired parameters. For MAP, an image-space penalty for regularization purposes is required. The benefits of 4D and direct reconstruction reported in the literature are reviewed, and furthermore demonstrated with simple simulation examples. It is clear that the future of reconstructing dynamic or functional emission tomography images, which often exhibit high levels of spatially correlated noise, should ideally exploit these 4D

  18. Role of de novo biosynthesis in ecosystem scale monoterpene emissions from a boreal Scots pine forest

    Directory of Open Access Journals (Sweden)

    R. Taipale

    2011-08-01

    Full Text Available Monoterpene emissions from Scots pine have traditionally been assumed to originate as evaporation from specialized storage pools. More recently, the significance of de novo emissions, originating directly from monoterpene biosynthesis, has been recognized. To study the role of biosynthesis at the ecosystem scale, we measured monoterpene emissions from a Scots pine dominated forest in southern Finland using the disjunct eddy covariance method combined with proton transfer reaction mass spectrometry. The interpretation of the measurements was based on a correlation analysis and a hybrid emission algorithm describing both de novo and pool emissions. During the measurement period May–August 2007, the monthly medians of daytime emissions were 200, 290, 180, and 200 μg m−2 h−1. The emissions were partly light dependent, probably due to de novo biosynthesis. The emission potential for both de novo and pool emissions exhibited a decreasing summertime trend. The ratio of the de novo emission potential to the total emission potential varied between 30 % and 46 %. Although the monthly changes were not significant, the ratio always differed statistically from zero, suggesting that the role of de novo biosynthesis was observable. Given the uncertainties in this study, we conclude that more accurate estimates of the contribution of de novo emissions are required for improving monoterpene emission algorithms for Scots pine dominated forests.

  19. C2-C10 hydrocarbon emissions from a boreal wetland and forest floor

    Directory of Open Access Journals (Sweden)

    H. Hellén

    2006-01-01

    Full Text Available Emissions of various C2-C10 hydrocarbons (VOCs and halogenated hydrocarbons (VHOCs from a boreal wetland and a Scots pine forest floor in south-western Finland were measured by the static chamber technique. Isoprene was the main non-methane hydrocarbon emitted by the wetland, but small emissions of ethene, propane, propene, 1-butene, 2-methylpropene, butane, pentane and hexane were also detected. The isoprene emission from the wetland was observed to follow the commonly-used isoprene emission algorithm. The mean emission potential of isoprene was 224 µg m-2 h-1 for the whole season. This is lower than the emission potentials published earlier; that is probably at least partly due to the cold and cloudy weather during the measurements. No emissions were detected of monoterpenes or halogenated hydrocarbons from the wetland. The highest hydrocarbon emissions from the Scots pine forest floor were measured in spring and autumn. However, only a few measurements were conducted during summer. The main compounds emitted were monoterpenes. Isoprene emissions were negligible. The total monoterpene emission rates varied from zero to 373 µg m-2 h-1. The results indicated that decaying plant litter may be the source for these emissions. Small emissions of chloroform (100-800 ng m-2 h-1, ethene, propane, propene, 2-methylpropene, cis-2-butene, pentane, hexane and heptane were detected. Comparison with Scots pine emissions showed that the forest floor may be an important monoterpene source, especially in spring.

  20. Energy-Dominated Local Carbon Emissions in Beijing 2007: Inventory and Input-Output Analysis

    Directory of Open Access Journals (Sweden)

    Shan Guo

    2012-01-01

    Full Text Available For greenhouse gas (GHG emissions by Beijing economy 2007, a concrete emission inventory covering carbon dioxide (CO2, methane (CH4, and nitrous oxide (N2O is presented and associated with an input-output analysis to reveal the local GHG embodiment in final demand and trade without regard to imported emissions. The total direct GHG emissions amount to 1.06E + 08 t CO2-eq, of which energy-related CO2 emissions comprise 90.49%, non-energy-related CO2 emissions 6.35%, CH4 emissions 2.33%, and N2O emissions 0.83%, respectively. In terms of energy-related CO2 emissions, the largest source is coal with a percentage of 53.08%, followed by coke with 10.75% and kerosene with 8.44%. Sector 26 (Construction Industry holds the top local emissions embodied in final demand of 1.86E + 07 t CO2-eq due to its considerable capital, followed by energy-intensive Sectors 27 (Transport and Storage and 14 (Smelting and Pressing of Ferrous and Nonferrous Metals. The GHG emissions embodied in Beijing's exports are 4.90E + 07 t CO2-eq, accounting for 46.01% of the total emissions embodied in final demand. The sound scientific database totally based on local emissions is an important basis to make effective environment and energy policies for local decision makers.