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Sample records for near-zero emissions part

  1. Preferential emission into epsilon-near-zero metamaterial [Invited

    SciTech Connect

    Galfsky, Tal; Sun, Zheng; Jacob, Zubin; Menon, Vinod M.

    2015-11-23

    We report the use of epsilon near zero (ENZ) metamaterial to control spontaneous emission from Zinc-Oxide (ZnO) excitons. The ENZ material consists of alternating layers of silver and alumina with subwavelength thicknesses, resulting in an effective medium where one of the components of the dielectric constant approach zero between 370nm-440nm wavelength range. Bulk ZnO with photoluminescence maximum in the ENZ regime was deposited via atomic layer deposition to obtain a smooth film with near field coupling to the ENZ metamaterial. Preferential emission from the ZnO layer into the metamaterial with suppression of forward emission by 90% in comparison to ZnO on silicon is observed. We attribute this observation to the presence of dispersionless plasmonic modes in the ENZ regime as shown by the results of theoretical modeling presented here. Integration of ENZ metamaterials with light emitters is an attractive platform for realizing a low threshold subwavelength laser.

  2. Propulsion Investigation for Zero and Near-Zero Emissions Aircraft

    NASA Technical Reports Server (NTRS)

    Snyder, Christopher A.; Berton, Jeffrey J.; Brown, Gerald v.; Dolce, James L.; Dravid, Marayan V.; Eichenberg, Dennis J.; Freeh, Joshua E.; Gallo, Christopher A.; Jones, Scott M.; Kundu, Krishna P.; Marek, Cecil J.; Millis, Marc G.; Murthy, Pappu L.; Roach, Timothy M.; Smith, Timothy D.; Stefko, George L.; Sullivan, Roy M.; Tornabene, Robert T.; Geiselhat, Karl A.; Kascak, Albert F.

    2009-01-01

    As world emissions are further scrutinized to identify areas for improvement, aviation s contribution to the problem can no longer be ignored. Previous studies for zero or near-zero emissions aircraft suggest aircraft and propulsion system sizes that would perform propulsion system and subsystems layout and propellant tankage analyses to verify the weight-scaling relationships. These efforts could be used to identify and guide subsequent work on systems and subsystems to achieve viable aircraft system emissions goals. Previous work quickly focused these efforts on propulsion systems for 70- and 100-passenger aircraft. Propulsion systems modeled included hydrogen-fueled gas turbines and fuel cells; some preliminary estimates combined these two systems. Hydrogen gas-turbine engines, with advanced combustor technology, could realize significant reductions in nitrogen emissions. Hydrogen fuel cell propulsion systems were further laid out, and more detailed analysis identified systems needed and weight goals for a viable overall system weight. Results show significant, necessary reductions in overall weight, predominantly on the fuel cell stack, and power management and distribution subsystems to achieve reasonable overall aircraft sizes and weights. Preliminary conceptual analyses for a combination of gas-turbine and fuel cell systems were also performed, and further studies were recommended. Using gas-turbine engines combined with fuel cell systems can reduce the fuel cell propulsion system weight, but at higher fuel usage than using the fuel cell only.

  3. Preferential emission into epsilon-near-zero metamaterial [Invited

    DOE PAGESBeta

    Galfsky, Tal; Sun, Zheng; Jacob, Zubin; Menon, Vinod M.

    2015-11-23

    We report the use of epsilon near zero (ENZ) metamaterial to control spontaneous emission from Zinc-Oxide (ZnO) excitons. The ENZ material consists of alternating layers of silver and alumina with subwavelength thicknesses, resulting in an effective medium where one of the components of the dielectric constant approach zero between 370nm-440nm wavelength range. Bulk ZnO with photoluminescence maximum in the ENZ regime was deposited via atomic layer deposition to obtain a smooth film with near field coupling to the ENZ metamaterial. Preferential emission from the ZnO layer into the metamaterial with suppression of forward emission by 90% in comparison to ZnOmore » on silicon is observed. We attribute this observation to the presence of dispersionless plasmonic modes in the ENZ regime as shown by the results of theoretical modeling presented here. Integration of ENZ metamaterials with light emitters is an attractive platform for realizing a low threshold subwavelength laser.« less

  4. Near-Zero Emissions Oxy-Combustion Flue Gas Purification

    SciTech Connect

    Minish Shah; Nich Degenstein; Monica Zanfir; Rahul Solunke; Ravi Kumar; Jennifer Bugayong; Ken Burgers

    2012-06-30

    The objectives of this project were to carry out an experimental program to enable development and design of near zero emissions (NZE) CO{sub 2} processing unit (CPU) for oxy-combustion plants burning high and low sulfur coals and to perform commercial viability assessment. The NZE CPU was proposed to produce high purity CO{sub 2} from the oxycombustion flue gas, to achieve > 95% CO{sub 2} capture rate and to achieve near zero atmospheric emissions of criteria pollutants. Two SOx/NOx removal technologies were proposed depending on the SOx levels in the flue gas. The activated carbon process was proposed for power plants burning low sulfur coal and the sulfuric acid process was proposed for power plants burning high sulfur coal. For plants burning high sulfur coal, the sulfuric acid process would convert SOx and NOx in to commercial grade sulfuric and nitric acid by-products, thus reducing operating costs associated with SOx/NOx removal. For plants burning low sulfur coal, investment in separate FGD and SCR equipment for producing high purity CO{sub 2} would not be needed. To achieve high CO{sub 2} capture rates, a hybrid process that combines cold box and VPSA (vacuum pressure swing adsorption) was proposed. In the proposed hybrid process, up to 90% of CO{sub 2} in the cold box vent stream would be recovered by CO{sub 2} VPSA and then it would be recycled and mixed with the flue gas stream upstream of the compressor. The overall recovery from the process will be > 95%. The activated carbon process was able to achieve simultaneous SOx and NOx removal in a single step. The removal efficiencies were >99.9% for SOx and >98% for NOx, thus exceeding the performance targets of >99% and >95%, respectively. The process was also found to be suitable for power plants burning both low and high sulfur coals. Sulfuric acid process did not meet the performance expectations. Although it could achieve high SOx (>99%) and NOx (>90%) removal efficiencies, it could not produce by

  5. Near Zero Emissions at 50 Percent Thermal Efficiency

    SciTech Connect

    None, None

    2012-12-31

    Detroit Diesel Corporation (DDC) has successfully completed a 10 year DOE sponsored heavy-duty truck engine program, hereafter referred to as the NZ-50 program. This program was split into two major phases. The first phase was called Near-Zero Emission at 50 Percent Thermal Efficiency, and was completed in 2007. The second phase was initiated in 2006, and this phase was named Advancements in Engine Combustion Systems to Enable High-Efficiency Clean Combustion for Heavy-Duty Engines. This phase was completed in September, 2010. The key objectives of the NZ-50 program for this first phase were to: Quantify thermal efficiency degradation associated with reduction of engine-out NOx emissions to the 2007 regulated level of ~1.1 g/hp-hr. Implement an integrated analytical/experimental development plan for improving subsystem and component capabilities in support of emerging engine technologies for emissions and thermal efficiency goals of the program. Test prototype subsystem hardware featuring technology enhancements and demonstrate effective application on a multi-cylinder, production feasible heavy-duty engine test-bed. Optimize subsystem components and engine controls (calibration) to demonstrate thermal efficiency that is in compliance with the DOE 2005 Joule milestone, meaning greater than 45% thermal efficiency at 2007 emission levels. Develop technology roadmap for meeting emission regulations of 2010 and beyond while mitigating the associated degradation in engine fuel consumption. Ultimately, develop technical prime-path for meeting the overall goal of the NZ-50 program, i.e., 50% thermal efficiency at 2010 regulated emissions. These objectives were successfully met during the course of the NZ-50 program. The most noteworthy achievements in this program are summarized as follows: Demonstrated technologies through advanced integrated experiments and analysis to achieve the technical objectives of the NZ-50 program with 50.2% equivalent thermal efficiency under

  6. Near-zero emissions combustor system for syngas and biofuels

    SciTech Connect

    Yongho, Kim; Rosocha, Louis

    2010-01-01

    research necessary to develop a novel, high-efficiency, low-emissions (near-zero, or as low as reasonably achievable), advanced combustion technology for electricity and heat production from biofuels and fuels derived from MSW. For any type of combustion technology, including the advanced technology of this project, two problems of special interest must be addressed: developing and optimizing the combustion chambers and the systems for igniting and sustaining the fuel-burning process. For MSW in particular, there are new challenges over gaseous or liquid fuels because solid fuels must be ground into fine particulates ({approx} 10 {micro}m diameter), fed into the advanced combustor, and combusted under plasma-assisted conditions that are quite different than gaseous or liquid fuels. The principal idea of the combustion chamber design is to use so-called reverse vortex gas flow, which allows efficient cooling of the chamber wall and flame stabilization in the central area of the combustor (Tornado chamber). Considerable progress has been made in design ing an advanced, reverse vortex flow combustion chamber for biofuels, although it was not tested on biofuels and a system that could be fully commercialized has never been completed.

  7. Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions

    PubMed Central

    Dyachenko, P. N.; Molesky, S.; Petrov, A. Yu; Störmer, M.; Krekeler, T.; Lang, S.; Ritter, M.; Jacob, Z.; Eich, M.

    2016-01-01

    Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C. PMID:27263653

  8. Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions.

    PubMed

    Dyachenko, P N; Molesky, S; Petrov, A Yu; Störmer, M; Krekeler, T; Lang, S; Ritter, M; Jacob, Z; Eich, M

    2016-01-01

    Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C. PMID:27263653

  9. Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions

    NASA Astrophysics Data System (ADS)

    Dyachenko, P. N.; Molesky, S.; Petrov, A. Yu; Störmer, M.; Krekeler, T.; Lang, S.; Ritter, M.; Jacob, Z.; Eich, M.

    2016-06-01

    Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C.

  10. FutureGen: Pathway to Near-Zero Emissions and Sustainable Energy

    SciTech Connect

    Zitney, S E; Sarkus, T A

    2007-11-04

    This presentation will highlight the U.S. Department of Energy’s (DOE) FutureGen project - a $1 billion government-industry partnership to design, build, and operate a near-zero emissions coal-fueled power plant. The lead organization for the FutureGen initiative is the National Energy Technology Laboratory (NETL), a multi-purpose laboratory operated by the U.S. DOE’s Office of Fossil Energy. NETL has a mission to conduct R&D from fundamental science to technology demonstration for resolving the environmental, supply, and reliability constraints of producing and using fossil energy resources. The commercial-scale FutureGen R&D facility is a pathway toward future fossil-energy power plants that will produce hydrogen and electricity while nearly eliminating emissions, including carbon dioxide. The 275-megawatt FutureGen plant will initiate operations around 2012 and employ advanced coal gasification technology integrated with combined cycle electricity generation, hydrogen production, and carbon capture and sequestration. Low carbon emissions would be achieved by integrating CO2 capture and sequestration operations with the power plant.

  11. A sulfuric-acid process with near-zero SO2 gas emissions

    NASA Astrophysics Data System (ADS)

    Jaeger, W.; Fattinger, V.; Keilpart, T.; Hamel, H.-J.

    1999-05-01

    A sulfuric-acid process has been developed that is able to handle low and variable SO2 concentrations with practically zero SO2 emissions (less than 3 ppm). The plant comprises two stages—a single-bed converter contact plant and a modified tower plant. Acids of 95 98% and/or oleum with up to 32% free SO3 can be produced in the first stage. Off-gas of the first stage is piped to the second stage, where the SO2 is converted to near nontracability while producing 76% strong acid. It is then returned to the contact plant to produce stronger acid or oleum. This process does not generate any additional disposable waste.

  12. The plasma properties and electron emission characteristics of near-zero differential resistance of hollow cathode-based plasma contactors with a discharge chamber

    SciTech Connect

    Xie, Kan; Farnell, Casey C.; Williams, John D.

    2014-08-15

    The formation of electron emission-bias voltage (I-V) characteristics of near-zero differential resistance in the cathodic plasma contactor for bare electrodynamic tether applications, based on a hollow cathode embedded in a ring-cusp ionization stage, is studied. The existence of such an I-V regime is important to achieve low impedance performance without being affected by the space plasma properties for a cathodic plasma contactor. Experimental data on the plasma structure and properties downstream from the ionization stage are presented as functions of the xenon flow rate and the electron emission current. The electrons were emitted from the cathode to the cylindrical vacuum chamber wall (r = 0.9 m) under ≈10{sup −5 }Torr of vacuum pressure. The ring-cusp configuration selected for the plasma contactor created a 125-Gauss axial field near the cathode orifice, along with a large-volume 50-Gauss magnitude pocket in the stage. A baseline ion energy cost of ≈300 eV/ion was measured in the ionization stage when no electrons were emitted to the vacuum chamber wall. In addition, the anode fall growth limited the maximum propellant unitization to below ≈75% in the discharge loss curves for this ion stage. Detailed measurements on the plasma properties were carried out for the no-electron emission and 3 A emission conditions. The experimental data are compared with 1-D models, and the effectiveness of the model is discussed. The four key issues that played important roles in the process of building the near-zero different resistance I-V regime are: a significant amount of ionization by the emission electrons, a decrease in the number of reflected electrons in the plume, the electron-temperature increment, and low initial ion energy at the source outlet.

  13. The plasma properties and electron emission characteristics of near-zero differential resistance of hollow cathode-based plasma contactors with a discharge chamber

    NASA Astrophysics Data System (ADS)

    Xie, Kan; Farnell, Casey C.; Williams, John D.

    2014-08-01

    The formation of electron emission-bias voltage (I-V) characteristics of near-zero differential resistance in the cathodic plasma contactor for bare electrodynamic tether applications, based on a hollow cathode embedded in a ring-cusp ionization stage, is studied. The existence of such an I-V regime is important to achieve low impedance performance without being affected by the space plasma properties for a cathodic plasma contactor. Experimental data on the plasma structure and properties downstream from the ionization stage are presented as functions of the xenon flow rate and the electron emission current. The electrons were emitted from the cathode to the cylindrical vacuum chamber wall (r = 0.9 m) under ≈10-5 Torr of vacuum pressure. The ring-cusp configuration selected for the plasma contactor created a 125-Gauss axial field near the cathode orifice, along with a large-volume 50-Gauss magnitude pocket in the stage. A baseline ion energy cost of ≈300 eV/ion was measured in the ionization stage when no electrons were emitted to the vacuum chamber wall. In addition, the anode fall growth limited the maximum propellant unitization to below ≈75% in the discharge loss curves for this ion stage. Detailed measurements on the plasma properties were carried out for the no-electron emission and 3 A emission conditions. The experimental data are compared with 1-D models, and the effectiveness of the model is discussed. The four key issues that played important roles in the process of building the near-zero different resistance I-V regime are: a significant amount of ionization by the emission electrons, a decrease in the number of reflected electrons in the plume, the electron-temperature increment, and low initial ion energy at the source outlet.

  14. Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 2: SOx/Nox/Hg Removal for High Sulfur Coal

    SciTech Connect

    Nick Degenstein; Minish Shah; Doughlas Louie

    2012-05-01

    The goal of this project is to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxy-combustion technology. The objective of Task 2 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning high sulfur coal in oxy-combustion power plants. The goal of the program was not only to investigate a new method of flue gas purification but also to produce useful acid byproduct streams as an alternative to using a traditional FGD and SCR for flue gas processing. During the project two main constraints were identified that limit the ability of the process to achieve project goals. 1) Due to boiler island corrosion issues >60% of the sulfur must be removed in the boiler island with the use of an FGD. 2) A suitable method could not be found to remove NOx from the concentrated sulfuric acid product, which limits sale-ability of the acid, as well as the NOx removal efficiency of the process. Given the complexity and safety issues inherent in the cycle it is concluded that the acid product would not be directly saleable and, in this case, other flue gas purification schemes are better suited for SOx/NOx/Hg control when burning high sulfur coal, e.g. this project's Task 3 process or a traditional FGD and SCR.

  15. Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 3: SOx/NOx/Hg Removal for Low Sulfur Coal

    SciTech Connect

    Zanfir, Monica; Solunke, Rahul; Shah, Minish

    2012-06-01

    The goal of this project was to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxycombustion technology. The objective of Task 3 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning low sulfur coal in oxy-combustion power plants. The goal of the program was to conduct an experimental investigation and to develop a novel process for simultaneously removal of SOx and NOx from power plants that would operate on low sulfur coal without the need for wet-FGD & SCRs. A novel purification process operating at high pressures and ambient temperatures was developed. Activated carbon's catalytic and adsorbent capabilities are used to oxidize the sulfur and nitrous oxides to SO{sub 3} and NO{sub 2} species, which are adsorbed on the activated carbon and removed from the gas phase. Activated carbon is regenerated by water wash followed by drying. The development effort commenced with the screening of commercially available activated carbon materials for their capability to remove SO{sub 2}. A bench-unit operating in batch mode was constructed to conduct an experimental investigation of simultaneous SOx and NOx removal from a simulated oxyfuel flue gas mixture. Optimal operating conditions and the capacity of the activated carbon to remove the contaminants were identified. The process was able to achieve simultaneous SOx and NOx removal in a single step. The removal efficiencies were >99.9% for SOx and >98% for NOx. In the longevity tests performed on a batch unit, the retention capacity could be maintained at high level over 20 cycles. This process was able to effectively remove up to 4000 ppm SOx from the simulated feeds corresponding to oxyfuel flue gas from high sulfur coal plants. A dual bed continuous unit with five times the capacity of the batch unit was constructed to test continuous operation and longevity. Full

  16. Precise quantization of anomalous Hall effect near zero magnetic field

    SciTech Connect

    Bestwick, A. J.; Fox, E. J.; Kou, Xufeng; Pan, Lei; Wang, Kang L.; Goldhaber-Gordon, D.

    2015-05-04

    In this study, we report a nearly ideal quantum anomalous Hall effect in a three-dimensional topological insulator thin film with ferromagnetic doping. Near zero applied magnetic field we measure exact quantization in the Hall resistance to within a part per 10,000 and a longitudinal resistivity under 1 Ω per square, with chiral edge transport explicitly confirmed by nonlocal measurements. Deviations from this behavior are found to be caused by thermally activated carriers, as indicated by an Arrhenius law temperature dependence. Using the deviations as a thermometer, we demonstrate an unexpected magnetocaloric effect and use it to reach near-perfect quantization by cooling the sample below the dilution refrigerator base temperature in a process approximating adiabatic demagnetization refrigeration.

  17. Cool flames at terrestrial, partial, and near-zero gravity

    SciTech Connect

    Foster, Michael; Pearlman, Howard

    2006-10-15

    Natural convection plays an important role in all terrestrial, Lunar, and Martian-based, unstirred, static reactor cool flame and low-temperature autoignitions, since the Rayleigh number (Ra) associated with the self-heating of the reaction exceeds the critical Ra (approximately 600) for onset of convection. At near-zero gravity, Ra<600 can be achieved and the effects of convection suppressed. To systematically vary the Ra without varying the mixture stoichiometry, reactor pressure, or vessel size, cool flames are studied experimentally in a closed, unstirred, static reactor subject to different gravitational accelerations (terrestrial, 1g; Martian, 0.38g; Lunar, 0.16g; and reduced gravity, {approx}10{sup -2}g). Representative results show the evolution of the visible light emission using an equimolar n-butane:oxygen premixture at temperatures ranging from 320 to 350? deg C (593-623 K) at subatmospheric pressures. For representative reduced-gravity, spherically propagating cool flames, the flame radius based on the peak light intensity is plotted as a function of time and the flame radius (and speed) is calculated from a polynomial fit to data. A skeletal chemical kinetic Gray-Yang model developed previously for a one-dimensional, reactive-diffusive system by Fairlie and co-workers is extended to a two-dimensional axisymmetric, spherical geometry. The coupled species, energy, and momentum equations are solved numerically and the spatio-temporal variations in the temperature profiles are presented. A qualitative comparison is made with the experimental results. (author)

  18. Young's experiment with waves near zeros.

    PubMed

    Senthilkumaran, Paramasivam; Bahl, Monika

    2015-05-01

    We report an interesting observation in the formation of Young's fringes from a two pinhole arrangement illuminated by waves from the neighborhood of a zero of an optical phase singularity. Spacing of the Young's fringes appears to defy the dependence of pin-hole separation. But for larger pinhole separation such an anomalous phenomenon is not discernible. The experiments show that the fringe spacing is governed by the stronger local phase gradient near the vortex core that also has a radial part. Many diffraction experiments reported so far have missed this aspect as the phase gradient in a vortex beam is normally considered to have only azimuthal and longitudinal components. This work reveals the vortex core structure and is the first experimental evidence to the existence of a radial component of this phase gradient. PMID:25969191

  19. Epsilon-near-zero mode for active optoelectronic devices.

    PubMed

    Vassant, S; Archambault, A; Marquier, F; Pardo, F; Gennser, U; Cavanna, A; Pelouard, J L; Greffet, J J

    2012-12-01

    The electromagnetic modes of a GaAs quantum well between two AlGaAs barriers are studied. At the longitudinal optical phonon frequency, the system supports a phonon polariton mode confined in the thickness of the quantum well that we call epsilon-near-zero mode. This epsilon-near-zero mode can be resonantly excited through a grating resulting in a very large absorption localized in the single quantum well. We show that the reflectivity can be modulated by applying a voltage. This paves the way to a new class of active optoelectronic devices working in the midinfrared and far infrared at ambient temperature. PMID:23368264

  20. Photon management with index-near-zero materials

    NASA Astrophysics Data System (ADS)

    Wang, Zhu; Wang, Ziyu; Yu, Zongfu

    2016-08-01

    Index-near-zero materials can be used for effective photon management. They help to restrict the angle of acceptance, resulting in greatly enhanced light trapping limit. In addition, these materials also decrease the radiative recombination, leading to enhanced open circuit voltage and energy efficiency in direct bandgap solar cells.

  1. Diffraction-free optical beam propagation with near-zero phase variation in extremely anisotropic metamaterials

    NASA Astrophysics Data System (ADS)

    Sun, Lei; Yang, Xiaodong; Wang, Wei; Gao, Jie

    2015-03-01

    Extremely anisotropic metal-dielectric multilayer metamaterials are designed to have the effective permittivity tensor of a transverse component (parallel to the interfaces of the multilayer) with zero real part and a longitudinal component (normal to the interfaces of the multilayer) with ultra-large imaginary part at the same wavelength, including the optical nonlocality analysis based on the transfer-matrix method. The diffraction-free deep-subwavelength optical beam propagation with near-zero phase variation in the designed multilayer stack due to the near-flat iso-frequency contour is demonstrated and analyzed, including the effects of the multilayer period and the material loss.

  2. Resurrection of the flagellar rotary motor near zero load

    PubMed Central

    Yuan, Junhua; Berg, Howard C.

    2008-01-01

    Flagellated bacteria, such as Escherichia coli, are propelled by helical flagellar filaments, each driven at its base by a reversible rotary motor, powered by a transmembrane proton flux. Torque is generated by the interaction of stator proteins, MotA and MotB, with a rotor protein FliG. The physiology of the motor has been studied extensively in the regime of relatively high load and low speed, where it appears to operate close to thermodynamic equilibrium. Here, we describe an assay that allows systematic study of the motor near zero load, where proton translocation and movement of mechanical components are rate limiting. Sixty-nanometer-diameter gold spheres were attached to hooks of cells lacking flagellar filaments, and light scattered from a sphere was monitored at the image plane of a microscope through a small pinhole. Paralyzed motors of cells carrying a motA point mutation were resurrected at 23°C by expression of wild-type MotA, and speeds jumped from zero to a maximum value (≈300 Hz) in one step. Thus, near zero load, the speed of the motor is independent of the number of torque-generating units. Evidently, the units act independently (they do not interfere with one another), and there are no intervals during which a second unit can add to the speed generated by the first (the duty ratio is close to 1). PMID:18202173

  3. Lattice gauge action suppressing near-zero modes of HW

    NASA Astrophysics Data System (ADS)

    Fukaya, Hidenori; Hashimoto, Shoji; Ishikawa, Ken-Ichi; Kaneko, Takashi; Matsufuru, Hideo; Onogi, Tetsuya; Yamada, Norikazu

    2006-11-01

    We propose a lattice action including unphysical Wilson fermions with a negative mass m0 of the order of the inverse lattice spacing. With this action, the exact zero mode of the Hermitian Wilson-Dirac operator HW(m0) cannot appear and near-zero modes are strongly suppressed. By measuring the spectral density ρ(λW), we find a gap near λW=0 on the configurations generated with the standard and improved gauge actions. This gap provides a necessary condition for the proof of the exponential locality of the overlap-Dirac operator by Hernandez, Jansen, and Lüscher. Since the number of near-zero modes is small, the numerical cost to calculate the matrix sign function of HW(m0) is significantly reduced, and the simulation including dynamical overlap fermions becomes feasible. We also introduce a pair of twisted mass pseudofermions to cancel the unwanted higher mode effects of the Wilson fermions. The gauge coupling renormalization due to the additional fields is then minimized. The topological charge measured through the index of the overlap-Dirac operator is conserved during continuous evolutions of gauge field variables.

  4. Enhanced Nonlinear Refractive Index in ɛ -Near-Zero Materials

    NASA Astrophysics Data System (ADS)

    Caspani, L.; Kaipurath, R. P. M.; Clerici, M.; Ferrera, M.; Roger, T.; Kim, J.; Kinsey, N.; Pietrzyk, M.; Di Falco, A.; Shalaev, V. M.; Boltasseva, A.; Faccio, D.

    2016-06-01

    New propagation regimes for light arise from the ability to tune the dielectric permittivity to extremely low values. Here, we demonstrate a universal approach based on the low linear permittivity values attained in the ɛ -near-zero (ENZ) regime for enhancing the nonlinear refractive index, which enables remarkable light-induced changes of the material properties. Experiments performed on Al-doped ZnO (AZO) thin films show a sixfold increase of the Kerr nonlinear refractive index (n2) at the ENZ wavelength, located in the 1300 nm region. This in turn leads to ultrafast light-induced refractive index changes of the order of unity, thus representing a new paradigm for nonlinear optics.

  5. Tailoring of nearly zero flattened dispersion photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Hsu, Jui-Ming

    2016-02-01

    This work theoretically tailored the dispersion in a photonic crystal fiber (PCF), and then designed two types of nearly zero dispersion flattened PCFs (DFPCFs) by rod-doping or liquid-filling some of the cladding holes. The numeric results show that the DFPCF type 1, rod-doped with arbitrary indices, achieves the dispersion values between 0±1 ps/nm km over a bandwidth range of 460 nm. The DFPCF type 2, filled with the available liquids, performs the dispersion values between 0±1.5 ps/nm km over a bandwidth range of 520 nm. Finally, the confinement losses of the two types of DFPCFs are estimated. The numeric results show that the confinement losses of the two types of the proposed DFPCFs are extremely low, in the order of 10-5 or 10-6 dB/km, which even can be disregarded.

  6. Enhanced Nonlinear Refractive Index in ε-Near-Zero Materials.

    PubMed

    Caspani, L; Kaipurath, R P M; Clerici, M; Ferrera, M; Roger, T; Kim, J; Kinsey, N; Pietrzyk, M; Di Falco, A; Shalaev, V M; Boltasseva, A; Faccio, D

    2016-06-10

    New propagation regimes for light arise from the ability to tune the dielectric permittivity to extremely low values. Here, we demonstrate a universal approach based on the low linear permittivity values attained in the ε-near-zero (ENZ) regime for enhancing the nonlinear refractive index, which enables remarkable light-induced changes of the material properties. Experiments performed on Al-doped ZnO (AZO) thin films show a sixfold increase of the Kerr nonlinear refractive index (n_{2}) at the ENZ wavelength, located in the 1300 nm region. This in turn leads to ultrafast light-induced refractive index changes of the order of unity, thus representing a new paradigm for nonlinear optics. PMID:27341234

  7. Terahertz epsilon-near-zero graded-index lens.

    PubMed

    Torres, Víctor; Pacheco-Peña, Víctor; Rodríguez-Ulibarri, Pablo; Navarro-Cía, Miguel; Beruete, Miguel; Sorolla, Mario; Engheta, Nader

    2013-04-01

    An epsilon-near-zero graded-index converging lens with planar faces is proposed and analyzed. Each perfectly-electric conducting (PEC) waveguide comprising the lens operates slightly above its cut-off frequency and has the same length but different cross-sectional dimensions. This allows controlling individually the propagation constant and the normalized characteristic impedance of each waveguide for the desired phase front at the lens output while Fresnel reflection losses are minimized. A complete theoretical analysis based on the waveguide theory and Fermat's principle is provided. This is complemented with numerical simulation results of two-dimensional and three-dimensional lenses, made of PEC and aluminum, respectively, and working in the terahertz regime, which show good agreement with the analytical work. PMID:23572004

  8. Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials

    PubMed Central

    Kaipurath, R. M.; Pietrzyk, M.; Caspani, L.; Roger, T.; Clerici, M.; Rizza, C.; Ciattoni, A.; Di Falco, A.; Faccio, D.

    2016-01-01

    Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial. PMID:27292270

  9. Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials

    NASA Astrophysics Data System (ADS)

    Kaipurath, R. M.; Pietrzyk, M.; Caspani, L.; Roger, T.; Clerici, M.; Rizza, C.; Ciattoni, A.; di Falco, A.; Faccio, D.

    2016-06-01

    Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial.

  10. Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials.

    PubMed

    Kaipurath, R M; Pietrzyk, M; Caspani, L; Roger, T; Clerici, M; Rizza, C; Ciattoni, A; Di Falco, A; Faccio, D

    2016-01-01

    Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial. PMID:27292270

  11. Electrically Tunable Epsilon-Near-Zero (ENZ) Metafilm Absorbers

    PubMed Central

    Park, Junghyun; Kang, Ju-Hyung; Liu, Xiaoge; Brongersma, Mark L.

    2015-01-01

    Enhancing and spectrally controlling light absorption is of great practical and fundamental importance. In optoelectronic devices consisting of layered semiconductors and metals, absorption has traditionally been manipulated with the help of Fabry-Pérot resonances. Even further control over the spectral light absorption properties of thin films has been achieved by patterning them into dense arrays of subwavelength resonant structures to form metafilms. As the next logical step, we demonstrate electrical control over light absorption in metafilms constructed from dense arrays of actively tunable plasmonic cavities. This control is achieved by embedding indium tin oxide (ITO) into these cavities. ITO affords significant tuning of its optical properties by means of electrically-induced carrier depletion and accumulation. We demonstrate that particularly large changes in the reflectance from such metafilms (up to 15% P) can be achieved by operating the ITO in the epsilon-near-zero (ENZ) frequency regime where its electrical permittivity changes sign from negative to positive values. PMID:26549615

  12. Electrically Tunable Epsilon-Near-Zero (ENZ) Metafilm Absorbers.

    PubMed

    Park, Junghyun; Kang, Ju-Hyung; Liu, Xiaoge; Brongersma, Mark L

    2015-01-01

    Enhancing and spectrally controlling light absorption is of great practical and fundamental importance. In optoelectronic devices consisting of layered semiconductors and metals, absorption has traditionally been manipulated with the help of Fabry-Pérot resonances. Even further control over the spectral light absorption properties of thin films has been achieved by patterning them into dense arrays of subwavelength resonant structures to form metafilms. As the next logical step, we demonstrate electrical control over light absorption in metafilms constructed from dense arrays of actively tunable plasmonic cavities. This control is achieved by embedding indium tin oxide (ITO) into these cavities. ITO affords significant tuning of its optical properties by means of electrically-induced carrier depletion and accumulation. We demonstrate that particularly large changes in the reflectance from such metafilms (up to 15% P) can be achieved by operating the ITO in the epsilon-near-zero (ENZ) frequency regime where its electrical permittivity changes sign from negative to positive values. PMID:26549615

  13. Coherent perfect absorption in epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Feng, Simin; Halterman, Klaus

    2012-10-01

    In conventional materials, strong absorption usually requires that the material have either high loss or a large thickness-to-wavelength ratio (d/λ≫1). We find the situation to be vastly different for bilayer structures composed of a metallic substrate and an anisotropic epsilon-near-zero (ENZ) metamaterial, where the permittivity in the direction perpendicular to its surface, ɛz, vanishes. Remarkably, perfect absorption can occur in situations where the metamaterial is arbitrarily thin (d/λ≪1) and arbitrarily low loss. Our numerical and analytical solutions reveal that under the conditions ɛz→0 and ℑ(ɛz)≫ℜ(ɛz), at perfect absorption there is a linear relationship between the thickness and the loss, which means the thickness of the absorber can be pushed to zero by reducing the material loss to zero. This counterintuitive behavior is explained in terms of coherent perfect absorption (or stimulated absorption) via critical coupling to a fast wave propagating along the ENZ layer.

  14. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers

    DOE PAGESBeta

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; Keeler, Gordon A.; Luk, Ting S.

    2016-01-01

    Here, we investigate optical polariton modes supported by subwavelength-thick degenerately doped semiconductor nanolayers (e.g. indium tin oxide) on glass in the epsilon-near-zero (ENZ) regime. The dispersions of the radiative (R, on the left of the light line) and non-radiative (NR, on the right of the light line) ENZ polariton modes are experimentally measured and theoretically analyzed through the transfer matrix method and the complex-frequency/real-wavenumber analysis, which are in remarkable agreement. We observe directional near-perfect absorption using the Kretschmann geometry for incidence conditions close to the NR-ENZ polariton mode dispersion. Along with field enhancement, this provides us with an unexplored pathwaymore » to enhance nonlinear optical processes and to open up directions for ultrafast, tunable thermal emission.« less

  15. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers.

    PubMed

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; Keeler, Gordon A; Luk, Ting S

    2016-08-01

    We investigate optical polariton modes supported by subwavelength-thick degenerately doped semiconductor nanolayers (e.g. indium tin oxide) on glass in the epsilon-near-zero (ENZ) regime. The dispersions of the radiative (R, on the left of the light line) and non-radiative (NR, on the right of the light line) ENZ polariton modes are experimentally measured and theoretically analyzed through the transfer matrix method and the complex-frequency/real-wavenumber analysis, which are in remarkable agreement. We observe directional near-perfect absorption using the Kretschmann geometry for incidence conditions close to the NR-ENZ polariton mode dispersion. Along with field enhancement, this provides us with an unexplored pathway to enhance nonlinear optical processes and to open up directions for ultrafast, tunable thermal emission. PMID:27505841

  16. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers

    SciTech Connect

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; Keeler, Gordon A.; Luk, Ting S.

    2016-01-01

    Here, we investigate optical polariton modes supported by subwavelength-thick degenerately doped semiconductor nanolayers (e.g. indium tin oxide) on glass in the epsilon-near-zero (ENZ) regime. The dispersions of the radiative (R, on the left of the light line) and non-radiative (NR, on the right of the light line) ENZ polariton modes are experimentally measured and theoretically analyzed through the transfer matrix method and the complex-frequency/real-wavenumber analysis, which are in remarkable agreement. We observe directional near-perfect absorption using the Kretschmann geometry for incidence conditions close to the NR-ENZ polariton mode dispersion. Along with field enhancement, this provides us with an unexplored pathway to enhance nonlinear optical processes and to open up directions for ultrafast, tunable thermal emission.

  17. Precise Quantization of the Anomalous Hall Effect near Zero Magnetic Field.

    PubMed

    Bestwick, A J; Fox, E J; Kou, Xufeng; Pan, Lei; Wang, Kang L; Goldhaber-Gordon, D

    2015-05-01

    We report a nearly ideal quantum anomalous Hall effect in a three-dimensional topological insulator thin film with ferromagnetic doping. Near zero applied magnetic field we measure exact quantization in the Hall resistance to within a part per 10 000 and a longitudinal resistivity under 1  Ω per square, with chiral edge transport explicitly confirmed by nonlocal measurements. Deviations from this behavior are found to be caused by thermally activated carriers, as indicated by an Arrhenius law temperature dependence. Using the deviations as a thermometer, we demonstrate an unexpected magnetocaloric effect and use it to reach near-perfect quantization by cooling the sample below the dilution refrigerator base temperature in a process approximating adiabatic demagnetization refrigeration. PMID:26001016

  18. Field-effect optical modulation based on epsilon-near-zero conductive oxide

    NASA Astrophysics Data System (ADS)

    Shi, Kaifeng; Lu, Zhaolin

    2016-07-01

    Epsilon-near-zero (ENZ, dielectric constant εr ≈ 0) materials have attracted significant research interest, however, their applications in the near-infrared regime are very limited. Conductive oxide (COx), owing to its moderate carrier concentration, is a candidate for ENZ material at telecom wavelengths based on the Drude model. Herein, we report an indium tin oxide (ITO) thin film as an ENZ material with cross-over wavelength, where real part of permittivity crosses zero, and enhanced light absorption at telecom wavelengths. We also report the investigation of electro-absorption modulation based on a metal-oxide-semiconductor (MOS)-like structure, more specifically a metal-oxide-ITO stack, where ITO works around ENZ. Based on the attenuated total reflectance (ATR) configuration, our test shows great promise for future electro-optical (EO) modulators. The operation speed of the MOS-like structure is limited mainly by RC delay.

  19. Optical properties of metal-dielectric based epsilon near zero metamaterials

    NASA Astrophysics Data System (ADS)

    Subramania, Ganapathi; Fischer, Arthur; Luk, Ting

    2014-03-01

    Epsilon(ɛ) near zero(ENZ) materials are metamaterials where the effective dielectric constant(ɛ) is close to zero for a range of wavelengths resulting in zero effective displacement field (D = ɛE) and displacement current. ENZ structures are of great interest in many application areas such as optical nanocircuits, supercoupling, cloaking, emission enhancement etc. Effective ENZ behavior has been demonstrated using cut-off frequency region in a metallic waveguide where the modal index vanishes. Here we demonstrate the fabrication of ENZ metamaterials operating at visible wavelengths (λ ~ 640nm) using an effective medium approach based on a metal-dielectric composites(App. Phys. Let.,101,241107(2012)) that can act as ``bulk'' ENZ material. The structure consists of a multilayer stack composite of alternating nanoscale thickness layers of Ag and TiO2. Optical spectroscopy shows transmission and absorption response is consistent with ENZ behavior and matches well with simulations. We will discuss the criteria necessary in the design and practical implementation of the composite that better approximates a homogenous effective medium including techniques to minimize the effect of optical losses to boost transmission. The potential for hosting gain media in the gratings to address losses and emission control will be discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. Preliminary Performance Evaluation of a Near Zero Energy Home in Callaway, Florida

    SciTech Connect

    Martin, Eric; Parker, Danny; Sherwin, John; Colon, Carlos

    2009-02-20

    This case study reports on a near zero energy home in Callaway, FL. This paper briefly reviews the design and then focuses on the first four months of energy performance during the second half of 2008.

  1. Field Evaluation of a Near Zero Energy Home in Oklahoma

    SciTech Connect

    Hendron, R.; Hancock, E.; Barker, G.; Reeves, P.

    2008-08-01

    The authors evaluated a zero energy home built by Ideal Homes in Edmond, Oklahoma, that included an extensive package of energy-efficient technologies and a photovoltaic array for site electricity generation. The home was part of a Building America research project in partnership with the Building Science Consortium to exhibit high efficiency technologies while keeping costs within the reach of average home buyers.

  2. Radiative engineering with refractory epsilon-near-zero metamaterials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Dyachenko, Pavel N.; Molesky, Sean; Petrov, Alexander Y.; Störmer, Michael; Krekeler, Tobias; Lang, Slawa; Ritter, Martin; Jacob, Zubin; Eich, Manfred

    2016-04-01

    Improvement in high-temperature stable spectrally selective absorbers and emitters is integral for the further development of thermophotovoltaic (TPV), lighting and solar thermal applications. However, the high operational temperatures (T>1000oC) required for efficient energy conversion, along with application specific criteria such as the operational range of low bandgap semiconductors, greatly restrict what can be accomplished with natural materials. Motivated by this challenge, we demonstrate the first example of high temperature thermal radiation engineering with metamaterials. By employing the naturally selective thermal excitation of radiative modes that occurs near topological transitions, we show that thermally stable highly selective emissivity features are achieved for temperatures up to 1000°C with low angular dependence in a sub-micron thick refractory tungsten/hafnium dioxide epsilon-near-zero (ENZ) metamaterial. We also investigate the main mechanisms of thermal degradation of the fabricated refractory metamaterial both in terms of optical performance and structural stability using spectral analysis and energy-dispersive X-ray spectroscopy (EDS) techniques. Importantly, we observe chemical stability of the constituent materials for temperatures up to 1000°C and structural stability beyond 1100°C. The scalable fabrication, requiring magnetron sputtering, and thermally robust optical properties of this metamaterial approach are ideally suited to high temperature emitter applications such as lighting or TPV. Our findings provide a first concrete proof of radiative engineering with high temperature topological transition in ENZ metamaterials, and establish a clear path for implementation in TPV energy harvesting applications.

  3. REVIEW ARTICLE Tokamak equilibria with nearly zero central current: the current hole

    NASA Astrophysics Data System (ADS)

    Fujita, Takaaki

    2010-11-01

    The observation of stable sustainment of the 'current hole', namely the nearly zero current density region in the central part of a tokamak plasma, has opened a new class of configurations in tokamak plasmas, and a variety of research from the viewpoints of equilibrium, magnetohydrodynamics (MHD) stability, particle orbits and radial transport has been generated. Some theories and codes have been tested and extended by being applied to extreme conditions in the current hole with very weak poloidal field. The current hole is generated due to a transient negative toroidal electric field established when a large off-axis non-inductive current is rapidly formed. It has been observed in high confinement plasmas with a large fraction of bootstrap current in advanced tokamak operation. The current hole is very stiff against current drive, which suggests that it is a saturated or self-organized system. Appearance of the current hole in ITER and DEMO would be expected in some of the operation scenarios, and its influence and its control methods have been studied. Results of experimental and theoretical studies on the current hole are reviewed.

  4. Anomalous nonlinear absorption in epsilon-near-zero materials: optical limiting and all-optical control.

    PubMed

    Vincenti, M A; de Ceglia, D; Scalora, Michael

    2016-08-01

    We investigate nonlinear absorption in films of epsilon-near-zero materials. The combination of large local electric fields at the fundamental frequency and material losses at the harmonic frequencies induce unusual intensity-dependent phenomena. We predict that the second-order nonlinearity of a low-damping, epsilon-near-zero slab produces an optical limiting effect that mimics a two-photon absorption process. Anomalous absorption profiles that depend on low permittivity values at the pump frequency are also predicted for third-order nonlinearities. These findings suggest new opportunities for all-optical light control and novel ways to design reconfigurable and tunable nonlinear devices. PMID:27472631

  5. Electromagnetic responses of curved fishnet structures: near-zero refractive index with lower loss

    NASA Astrophysics Data System (ADS)

    Soemphol, Chaiyong; Kitchin, Steven F.; Fiddy, Michael A.; Wongkasem, Nantakan

    2016-02-01

    Fishnet structure metamaterials are modified by introducing some curvature at the corners of the slabs and the neck lines in order to tailor a uniform current distribution as well as field concentration in the microwave regime. The results obtained show that these modified fishnet structures can generate 20% broader low loss near-zero index bandwidth as compared to that of the original fishnet structures. The majority of the near-zero bands of the modified fishnet structures produce lower loss than those of the original fishnet structures at the same frequency.

  6. Kinematic origin for near-zero energy structures in mid-IR strong field ionization

    NASA Astrophysics Data System (ADS)

    Pisanty, Emilio; Ivanov, Misha

    2016-05-01

    We propose and discuss a kinematic mechanism underlying the recently discovered ‘near-zero energy structure’ in the photoionization of atoms in strong mid-infrared laser fields, based on trajectories which revisit the ion at low velocities exactly analogous to the series responsible for low-energy structures. The different scaling of the new series, as E∼ {I}p2/{U}p, suggests that the near-zero energy structure can be lifted to higher energies, where it can be better resolved and studied, using harder targets with higher ionization potential.

  7. Perfect electromagnetic absorption using graphene and epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Lobet, Michaël; Majerus, Bruno; Henrard, Luc; Lambin, Philippe

    2016-06-01

    The ability of graphene/polymer heterostructures to absorb GHz electromagnetic radiation was recently evidenced both theoretically and experimentally [Batrakov et al., Sci. Rep. 4, 7191 (2014), 10.1038/srep07191 and Lobet et al., Nanotechnology 26, 285702 (2015), 10.1088/0957-4484/26/28/285702]. Maximum absorption was shown to depend solely on refractive indices of incident and emergence media once impedance matching conditions are fulfilled. In this paper, analytical models and numerical simulations are performed for both semi-infinite and finite slab substrate. We evidenced that only three graphene layers separated by a dielectric spacer and an epsilon-near-zero metamaterial as emergence medium allow a perfect absorption for normal incidence. The use of lossless epsilon-near-zero metamaterial prevents radiations to go through the device, because of infinite impedance, and forces them to be totally absorbed in the dissipative medium (graphene). The device is proved to be robust regarding angular incidence up to 45 deg for a semi-infinite epsilon-near-zero metamaterial. The proposed strategy is universal and can be applied to any kind of two-dimensional dissipative materials lying on epsilon-near-zero metamaterial. The proposed absorber does not rely on surface patterning or texturing and hence is more appealing for device applications.

  8. Preminary Performance Evaluation of a Near Zero Energy Home in Gainesville, Florida

    SciTech Connect

    Parker, Danny; Sherwin, John; Hoak, David; Chandra, Subrao; Martin, Eric

    2009-02-20

    This case study is a summary on a near zero energy home that was built in Gainesville, FL as a result of collaboration between the Florida Solar Enegery Center and the Florida H.E.R.O., an innovative developer and builder.

  9. Near-Zero NOx Combustion Technology for ATS Mercury 50 Gas Turbine

    SciTech Connect

    Kenneth Smith

    2004-12-31

    A project to demonstrate a near-zero NOx, catalytic combustion technology for natural gas-fired, industrial gas turbines is described. In a cooperative effort between Solar Turbines Incorporated and Precision Combustion Incorporated (PCI), proof-of-concept rig testing of PCI's fuel-rich catalytic combustion technology has been completed successfully. The primary technical goal of the project was to demonstrate NOx and CO emissions below 5ppm and 10 ppm, respectively, (corrected to 15% O{sub 2}) at realistic gas turbine operating conditions. The program consisted of two tasks. In the first task, a single prototype RCL{trademark} (Rich Catalytic Lean Burn) module was demonstrated at Taurus 70 (7.5 Mw) operating conditions (1.6 MPa, 16 atm) in a test rig. For a Taurus 70 engine, eight to twelve RCL modules will be required, depending on the final system design. In the second task, four modules of a similar design were adapted to a Saturn engine (1 Mw) test rig (600 kPa, 6 atm) to demonstrate gas turbine light-off and operation with an RCL combustion system. This project was initially focused on combustion technology for the Mercury 50 engine. However, early in the program, the Taurus 70 replaced the Mercury. This substitution was motivated by the larger commercial market for an ultra-low NOx Taurus 70 in the near-term. Rig tests using a single prototype RCL module at Taurus 70 conditions achieved NOx emissions as low as 0.75 ppm. A combustor turndown of approximately 110C (200F) was achieved with NOx and CO emissions below 3 ppm and 10 ppm, respectively. Catalyst light-off occurred at an inlet temperature of 310C (590F). Once lit the module remained active at inlet air temperatures as low as 204C (400F). Combustor pressure oscillations were acceptably low during module testing. Single module rig tests were also conducted with the Taurus 70 module reconfigured with a central pilot fuel injector. Such a pilot will be required in a commercial RCL system for turbine light

  10. Acoustic planar hyperlens based on anisotropic density-near-zero metamaterials

    SciTech Connect

    Gu, Yuan; Cheng, Ying Liu, Xiaojun

    2015-09-28

    Based on anisotropic density-near-zero metamaterials, we demonstrate a planar hyperlens with resolution beyond the diffraction limit in both one and two lateral dimensions. In contrast to the cylindrical hyperlens with elliptical dispersions of finite anisotropy, the proposed planar hyperlens is designed with flat near-zero dispersion that supports wave tunneling with extremely high phase velocity for infinite large transverse wave vectors. Therefore, the acoustic evanescent waves immediately concentrate into the designed oblique path till the output surface, leading to a subwavelength resolution. Prototype hyperlens is constructed with a membrane-network by means of equivalent lumped-circuit model, and the subwavelength magnifying performance for a pair of one-dimensional line objects as well as the complex two-dimensional structure is demonstrated. This method provides diverse routes to construct hyperlens operating without the limitation on imaging region in practical applications.

  11. Stability and multiple bifurcations of a damped harmonic oscillator with delayed feedback near zero eigenvalue singularity.

    PubMed

    Song, Yongli; Zhang, Tonghua; Tadé, Moses O

    2008-12-01

    We investigate the dynamics of a damped harmonic oscillator with delayed feedback near zero eigenvalue singularity. We perform a linearized stability analysis and multiple bifurcations of the zero solution of the system near zero eigenvalue singularity. Taking the time delay as the bifurcation parameter, the presence of steady-state bifurcation, Bogdanov-Takens bifurcation, triple zero, and Hopf-zero singularities is demonstrated. In the case when the system has a simple zero eigenvalue, center manifold reduction and normal form theory are used to investigate the stability and the types of steady-state bifurcation. The stability of the zero solution of the system near the simple zero eigenvalue singularity is completely solved. PMID:19123623

  12. Negative and near zero refraction metamaterials based on permanent magnetic ferrites

    PubMed Central

    Bi, Ke; Guo, Yunsheng; Zhou, Ji; Dong, Guoyan; Zhao, Hongjie; Zhao, Qian; Xiao, Zongqi; Liu, Xiaoming; Lan, Chuwen

    2014-01-01

    Ferrite metamaterials based on the negative permeability of ferromagnetic resonance in ferrites are of great interest. However, such metamaterials face a limitation that the ferromagnetic resonance can only take place while an external magnetic field applied. Here, we demonstrate a metamaterial based on permanent magnetic ferrite which exhibits not only negative refraction but also near zero refraction without applied magnetic field. The wedge-shaped and slab-shaped structures of permanent magnetic ferrite-based metamaterials were prepared and the refraction properties were measured in a near-field scanning system. The negative and near zero refractive behaviors are confirmed by the measured spatial electric field maps. This work offers new opportunities for the development of ferrite-based metamaterials. PMID:24553188

  13. Negative and near zero refraction metamaterials based on permanent magnetic ferrites.

    PubMed

    Bi, Ke; Guo, Yunsheng; Zhou, Ji; Dong, Guoyan; Zhao, Hongjie; Zhao, Qian; Xiao, Zongqi; Liu, Xiaoming; Lan, Chuwen

    2014-01-01

    Ferrite metamaterials based on the negative permeability of ferromagnetic resonance in ferrites are of great interest. However, such metamaterials face a limitation that the ferromagnetic resonance can only take place while an external magnetic field applied. Here, we demonstrate a metamaterial based on permanent magnetic ferrite which exhibits not only negative refraction but also near zero refraction without applied magnetic field. The wedge-shaped and slab-shaped structures of permanent magnetic ferrite-based metamaterials were prepared and the refraction properties were measured in a near-field scanning system. The negative and near zero refractive behaviors are confirmed by the measured spatial electric field maps. This work offers new opportunities for the development of ferrite-based metamaterials. PMID:24553188

  14. Pulse dynamics in carbon nanotube mode-locked fiber lasers near zero cavity dispersion.

    PubMed

    Wang, Jinzhang; Cai, Zhiping; Xu, Ping; Du, Geguo; Wang, Fengqiu; Ruan, Shuangchen; Sun, Zhipei; Hasan, Tawfique

    2015-04-20

    We numerically and experimentally analyze the output characteristics and pulse dynamics of carbon nanotube mode-locked fiber lasers near zero cavity dispersion (from 0.02 to ~-0.02 ps(2)). We focus on such near zero dispersion cavities to reveal the dispersion related transition between different mode-locking regimes (such as soliton-like, stretched-pulse and self-similar regimes). Using our proposed model, we develop a nanotube-mode-locked fiber laser setup generating ~97 fs pulse which operates in the stretched-pulse regime. The corresponding experimental results and pulse dynamics are in good agreement with the numerical results. Also, the experimental results from soliton-like and self-similar regimes exhibit the same trends with simulations. Our study will aid design of different mode-locking regimes based on other new saturable absorber materials to achieve ultra-short pulse duration. PMID:25969036

  15. Optical response of dipole antennas on an epsilon-near-zero substrate

    NASA Astrophysics Data System (ADS)

    Schulz, Sebastian A.; Tahir, Asad A.; Alam, M. Zahirul; Upham, Jeremy; De Leon, Israel; Boyd, Robert W.

    2016-06-01

    Materials with vanishing permittivity (epsilon-near-zero or ENZ materials) show unconventional optical behavior. Here we show that plasmonic dipole antennas on an ultrathin ENZ substrate have properties significantly different from antennas on a traditional substrate. Specifically, the presence of a 23-nm-thick ENZ material strongly modifies the linear response of plasmonic antennas and, as a result, the resonant wavelength is independent of the linear dimensions of the dipole antenna.

  16. Wave-matter interactions in epsilon-and-mu-near-zero structures

    NASA Astrophysics Data System (ADS)

    Mahmoud, Ahmed M.; Engheta, Nader

    2014-12-01

    In recent years, the concept of metamaterials has offered platforms for unconventional tailoring and manipulation of the light-matter interaction. Here we explore the notion of ‘static optics’, in which the electricity and magnetism are decoupled, while the fields are temporally dynamic. This occurs when both the relative effective permittivity and permeability attain near-zero values at a given operating frequency. We theoretically investigate some of the resulting wave features in bounded scenarios, such as unusual radiation characteristics of an emitter embedded in such epsilon-and-mu-near-zero media in bounded environments. Using such media, one might in principle ‘open up’ and ‘stretch’ the space, and have regions behaving electromagnetically as ‘single points’ despite being electrically large. We suggest a possible design for implementation of such structures using a single dielectric rod inserted in a waveguide operating near its cutoff frequency, providing the possibility of having electrically large ‘empty’ volumes to behave as epsilon-and-mu-near-zero media.

  17. Molecular and Metabolic Adaptations of Lactococcus lactis at Near-Zero Growth Rates

    PubMed Central

    Ercan, Onur; Wels, Michiel; Smid, Eddy J.

    2014-01-01

    This paper describes the molecular and metabolic adaptations of Lactococcus lactis during the transition from a growing to a near-zero growth state by using carbon-limited retentostat cultivation. Transcriptomic analyses revealed that metabolic patterns shifted between lactic- and mixed-acid fermentations during retentostat cultivation, which appeared to be controlled at the level of transcription of the corresponding pyruvate dissipation-encoding genes. During retentostat cultivation, cells continued to consume several amino acids but also produced specific amino acids, which may derive from the conversion of glycolytic intermediates. We identify a novel motif containing CTGTCAG in the upstream regions of several genes related to amino acid conversion, which we propose to be the target site for CodY in L. lactis KF147. Finally, under extremely low carbon availability, carbon catabolite repression was progressively relieved and alternative catabolic functions were found to be highly expressed, which was confirmed by enhanced initial acidification rates on various sugars in cells obtained from near-zero-growth cultures. The present integrated transcriptome and metabolite (amino acids and previously reported fermentation end products) study provides molecular understanding of the adaptation of L. lactis to conditions supporting low growth rates and expands our earlier analysis of the quantitative physiology of this bacterium at near-zero growth rates toward gene regulation patterns involved in zero-growth adaptation. PMID:25344239

  18. Wave-matter interactions in epsilon-and-mu-near-zero structures.

    PubMed

    Mahmoud, Ahmed M; Engheta, Nader

    2014-01-01

    In recent years, the concept of metamaterials has offered platforms for unconventional tailoring and manipulation of the light-matter interaction. Here we explore the notion of 'static optics', in which the electricity and magnetism are decoupled, while the fields are temporally dynamic. This occurs when both the relative effective permittivity and permeability attain near-zero values at a given operating frequency. We theoretically investigate some of the resulting wave features in bounded scenarios, such as unusual radiation characteristics of an emitter embedded in such epsilon-and-mu-near-zero media in bounded environments. Using such media, one might in principle 'open up' and 'stretch' the space, and have regions behaving electromagnetically as 'single points' despite being electrically large. We suggest a possible design for implementation of such structures using a single dielectric rod inserted in a waveguide operating near its cutoff frequency, providing the possibility of having electrically large 'empty' volumes to behave as epsilon-and-mu-near-zero media. PMID:25476550

  19. Goos-Hänchen shift of partially coherent light fields in epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Ziauddin; Chuang, You-Lin; Qamar, Sajid; Lee, Ray-Kuang

    2016-05-01

    The Goos-Hänchen (GH) shifts in the reflected light are investigated both for p and s polarized partial coherent light beams incident on epsilon-near-zero (ENZ) metamaterials. In contrary to the coherent counterparts, the magnitude of GH shift becomes non-zero for p polarized partial coherent light beam; while GH shift can be relatively large with a small degree of spatial coherence for s polarized partial coherent beam. Dependence on the beam width and the permittivity of ENZ metamaterials is also revealed for partial coherent light fields. Our results on the GH shifts provide a direction on the applications for partial coherent light sources in ENZ metamaterials.

  20. Metasurfaces and epsilon-near-zero modes in semiconductors (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Brener, Igal; Campione, Salvatore; Marquier, Francois

    2015-09-01

    Thin layers of semiconductors where the permittivity crosses zero, support a particular polariton mode called epsilon-near-zero (ENZ) mode. This zero crossing can be obtained near optical phonon resonances in dielectrics or the plasma frequency in doped semiconductors. The coupling of metamaterial resonators to these ENZ modes leads to particularly large Rabi splittings. ENZ layers can be added to metamaterial-based strongly coupled systems to increase this coupling even further. I will discuss several examples of these coupled systems that include metasurfaces, phonons, intersubband transitions and ENZ modes.

  1. Evanescent wave amplification and subwavelength imaging by ultrathin uniaxial μ-near-zero material

    SciTech Connect

    Zhao, Yan

    2014-02-15

    We demonstrate strong evanescent wave amplification by a thin slab of uniaxial μ-near-zero (UMNZ) material. It is found that while retaining the same amplification effect, the slab can be made arbitrarily thin when the negative permeability along the axis of anisotropy approaches zero. Numerical results show that using a single layer of split-ring resonators (SRRs) with its thickness equal three thousandth of the incident wavelength (λ/3000), a subwavelength source distribution with λ/4 resolution can be transferred to a distance of λ/3.

  2. All-optical modulation in wavelength-sized epsilon-near-zero media.

    PubMed

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2016-07-01

    We investigate the interaction of two pulses (pump and probe) scattered by a nonlinear epsilon-near-zero (ENZ) slab whose thickness is comparable with the ENZ wavelength. We show that when the probe has a narrow spectrum localized around the ENZ wavelength, its transmission is dramatically affected by the intensity of the pump. Conversely, if the probe is not in the ENZ regime, its propagation is not noticeably affected by the pump. Such all-optical modulation is due to the oversensitive character of the ENZ regime, and it is so efficient that it even occurs in a wavelength thick slab. PMID:27367112

  3. Magneto-optical characteristics of layered Epsilon-Near-Zero metamaterials

    NASA Astrophysics Data System (ADS)

    Abdi-Ghaleh, Reza; Suldozi, Reza

    2016-09-01

    The transmittance magneto-optical (MO) characteristics of Epsilon-Near-Zero (ENZ) metamaterials are studied, using 4 by 4 transfer matrix method. The considered structures are a free standing ENZ-MO slab, and a microcavity type multi-layer structure containing an ENZ-MO layer. The transmittance coefficients of the right- and left-handed circular polarizations for the slab are analytically obtained and numerically investigated. Furthermore, these characteristics are numerically studied for the multi-layer structure. In addition, the Faraday rotations of both structures are investigated. The results reveal the circular polarization filtering effects.

  4. Enhanced third harmonic generation from the epsilon-near-zero modes of ultrathin films

    SciTech Connect

    Luk, Ting S. Liu, Sheng; Campione, Salvatore; Ceglia, Domenico de; Vincenti, Maria A.; Keeler, Gordon A.; Sinclair, Michael B.; Prasankumar, Rohit P.; Scalora, Michael

    2015-04-13

    We experimentally demonstrate efficient third harmonic generation from an indium tin oxide nanofilm (λ/42 thick) on a glass substrate for a pump wavelength of 1.4 μm. A conversion efficiency of 3.3 × 10{sup −6} is achieved by exploiting the field enhancement properties of the epsilon-near-zero mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.

  5. Enhanced third harmonic generation from the epsilon-near-zero modes of ultrathin films

    NASA Astrophysics Data System (ADS)

    Luk, Ting S.; de Ceglia, Domenico; Liu, Sheng; Keeler, Gordon A.; Prasankumar, Rohit P.; Vincenti, Maria A.; Scalora, Michael; Sinclair, Michael B.; Campione, Salvatore

    2015-04-01

    We experimentally demonstrate efficient third harmonic generation from an indium tin oxide nanofilm (λ/42 thick) on a glass substrate for a pump wavelength of 1.4 μm. A conversion efficiency of 3.3 × 10-6 is achieved by exploiting the field enhancement properties of the epsilon-near-zero mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.

  6. Near-Zero Emissions Oxy-Combustion Flue Gas Purification - Power Plant Performance

    SciTech Connect

    Andrew Seltzer; Zhen Fan

    2011-03-01

    A technical feasibility assessment was performed for retrofitting oxy-fuel technology to an existing power plant burning low sulfur PRB fuel and high sulfur bituminous fuel. The focus of this study was on the boiler/power generation island of a subcritical steam cycle power plant. The power plant performance in air and oxy-firing modes was estimated and modifications required for oxy-firing capabilities were identified. A 460 MWe (gross) reference subcritical PC power plant was modeled. The reference air-fired plant has a boiler efficiency (PRB/Bituminous) of 86.7%/89.3% and a plant net efficiency of 35.8/36.7%. Net efficiency for oxy-fuel firing including ASU/CPU duty is 25.6%/26.6% (PRB/Bituminous). The oxy-fuel flue gas recirculation flow to the boiler is 68%/72% (PRB/bituminous) of the flue gas (average O{sub 2} in feed gas is 27.4%/26.4%v (PRB/bituminous)). Maximum increase in tube wall temperature is less than 10ºF for oxy-fuel firing. For oxy-fuel firing, ammonia injected to the SCR was shut-off and the FGD is applied to remove SOx from the recycled primary gas stream and a portion of the SOx from the secondary stream for the high sulfur bituminous coal. Based on CFD simulations it was determined that at the furnace outlet compared to air-firing, SO{sub 3}/SO{sub 2} mole ratio is about the same, NOx ppmv level is about the same for PRB-firing and 2.5 times for bituminous-firing due to shutting off the OFA, and CO mole fraction is approximately double. A conceptual level cost estimate was performed for the incremental equipment and installation cost of the oxyfuel retrofit in the boiler island and steam system. The cost of the retrofit is estimated to be approximately 81 M$ for PRB low sulfur fuel and 84 M$ for bituminous high sulfur fuel.

  7. Development of Biomimetic Membranes for Near Zero PC Power Plant Emissions

    SciTech Connect

    Michael Trachtenberg; Robert Cowan; David Smith; Ira Sider

    2009-07-31

    The first objective of this project was to develop, evaluate and compare two different CO2 separation (capture) systems. The second was to carry the preferred solution to pre-pilot development and testing. To achieve these objectives we undertook several infrastructure enabling elements: (1) development of a preferred catalyst coupled with its immobilization onto a microporous polymer membrane, (2) design and development of a microporous membrane-based, contained liquid membrane permeator and a membrane-based absorber/desorber apparatus, (3) development of a resin-wafer electrodialytic absorber/desorber apparatus, (4) development and demonstration of a pre-treatment process to condition the feed gas stream, (5) and development of computer modeling of the components and of the integrated system. The first technology was an enzyme catalyzed, membrane supported, contained liquid membrane apparatus whose gas capture was pressure/vacuum and temperature driven. A first embodiment was as a permeator, i.e. a combined absorber/desorber in a single housing. The second embodiment was as discrete absorber and desorber units. The second technology was an enzyme catalyzed, ion exchange resin wafer electrodialytically-based separation. For each of these technologies the objective was to design, manufacture, test and demonstrate the apparatus, first in the laboratory and then at pre-pilot scale, and to run it for sufficient time at the pre-pilot scale to demonstrate stability even in the face of upset. Tests would include several ranks of coal, which had been appropriately pre-treated to remove NOx, SOx and particles, to a pre-determined acceptance level, as a basis for demonstrating efficient CO{sub 2} capture. The pre-pilot tests would be run at the Energy and Environmental Research Center (EERC) in North Dakota. A larger scale test (400m{sup 2} test unit) would later be run also at EERC. An economic goal was to compare the cost of CO{sub 2} capture by each of these methods with values obtained when using MEA (monoethanolamine) as a baseline case. Other metrics included capital and operating expense, parasitic loss and cost of electricity. A final goal was to carry out an initial examination of market forces to understand what barriers to entry for installation of CO{sub 2} capture equipment might exist and their relative importance.

  8. Self-organization of frozen light in near-zero-index media with cubic nonlinearity

    PubMed Central

    Marini, A.; García de Abajo, F. J.

    2016-01-01

    Optical beams are generally unbound in bulk media, and propagate with a velocity approximately amounting to the speed of light in free-space. Guidance and full spatial confinement of light are usually achieved by means of waveguides, mirrors, resonators, and photonic crystals. Here we theoretically demonstrate that nonlinear self-organization can be exploited to freeze optical beams in bulk near-zero-index media, thus enabling three-dimensional self-trapping of still light without the need of optical resonators. Light is stopped to a standstill owing to the divergent wavelength and the vanishing group velocity, effectively rendering, through nonlinearity, a positive-epsilon trapping cavity carved in an otherwise slightly-negative-epsilon medium. By numerically solving Maxwell’s equations, we find a soliton-like family of still azimuthal doughnuts, which we further study through an adiabatic perturbative theory that describes soliton evaporation in lossy media or condensation in actively pumped materials. Our results suggest applications in optical data processing and storage, quantum optical memories, and soliton-based lasers without cavities. Additionally, near-zero-index conditions can also be found in the interplanetary medium and in the atmosphere, where we provide a complementary explanation to the rare phenomenon of ball-lightning. PMID:26847877

  9. Solar Assisted Ground Source Heat Pump Performance in Nearly Zero Energy Building in Baltic Countries

    NASA Astrophysics Data System (ADS)

    Januševičius, Karolis; Streckienė, Giedrė

    2013-12-01

    In near zero energy buildings (NZEB) built in Baltic countries, heat production systems meet the challenge of large share domestic hot water demand and high required heating capacity. Due to passive solar design, cooling demand in residential buildings also needs an assessment and solution. Heat pump systems are a widespread solution to reduce energy use. A combination of heat pump and solar thermal collectors helps to meet standard requirements and increases the share of renewable energy use in total energy balance of country. The presented paper describes a simulation study of solar assisted heat pump systems carried out in TRNSYS. The purpose of this simulation was to investigate how the performance of a solar assisted heat pump combination varies in near zero energy building. Results of three systems were compared to autonomous (independent) systems simulated performance. Different solar assisted heat pump design solutions with serial and parallel solar thermal collector connections to the heat pump loop were modelled and a passive cooling possibility was assessed. Simulations were performed for three Baltic countries: Lithuania, Latvia and Estonia.

  10. Quasi-Static Magnetic Field Shielding Using Longitudinal Mu-Near-Zero Metamaterials

    PubMed Central

    Lipworth, Guy; Ensworth, Joshua; Seetharam, Kushal; Lee, Jae Seung; Schmalenberg, Paul; Nomura, Tsuyoshi; Reynolds, Matthew S.; Smith, David R.; Urzhumov, Yaroslav

    2015-01-01

    The control of quasi-static magnetic fields is of considerable interest in applications including the reduction of electromagnetic interference (EMI), wireless power transfer (WPT), and magnetic resonance imaging (MRI). The shielding of static or quasi-static magnetic fields is typically accomplished through the use of inherently magnetic materials with large magnetic permeability, such as ferrites, used sometimes in combination with metallic sheets and/or active field cancellation. Ferrite materials, however, can be expensive, heavy and brittle. Inspired by recent demonstrations of epsilon-, mu- and index-near-zero metamaterials, here we show how a longitudinal mu-near-zero (LMNZ) layer can serve as a strong frequency-selective reflector of magnetic fields when operating in the near-field region of dipole-like sources. Experimental measurements with a fabricated LMNZ sheet constructed from an artificial magnetic conductor – formed from non-magnetic, conducting, metamaterial elements – confirm that the artificial structure provides significantly improved shielding as compared with a commercially available ferrite of the same size. Furthermore, we design a structure to shield simultaneously at the fundamental and first harmonic frequencies. Such frequency-selective behavior can be potentially useful for shielding electromagnetic sources that may also generate higher order harmonics, while leaving the transmission of other frequencies unaffected. PMID:26234929

  11. Quasi-Static Magnetic Field Shielding Using Longitudinal Mu-Near-Zero Metamaterials

    NASA Astrophysics Data System (ADS)

    Lipworth, Guy; Ensworth, Joshua; Seetharam, Kushal; Lee, Jae Seung; Schmalenberg, Paul; Nomura, Tsuyoshi; Reynolds, Matthew S.; Smith, David R.; Urzhumov, Yaroslav

    2015-08-01

    The control of quasi-static magnetic fields is of considerable interest in applications including the reduction of electromagnetic interference (EMI), wireless power transfer (WPT), and magnetic resonance imaging (MRI). The shielding of static or quasi-static magnetic fields is typically accomplished through the use of inherently magnetic materials with large magnetic permeability, such as ferrites, used sometimes in combination with metallic sheets and/or active field cancellation. Ferrite materials, however, can be expensive, heavy and brittle. Inspired by recent demonstrations of epsilon-, mu- and index-near-zero metamaterials, here we show how a longitudinal mu-near-zero (LMNZ) layer can serve as a strong frequency-selective reflector of magnetic fields when operating in the near-field region of dipole-like sources. Experimental measurements with a fabricated LMNZ sheet constructed from an artificial magnetic conductor - formed from non-magnetic, conducting, metamaterial elements - confirm that the artificial structure provides significantly improved shielding as compared with a commercially available ferrite of the same size. Furthermore, we design a structure to shield simultaneously at the fundamental and first harmonic frequencies. Such frequency-selective behavior can be potentially useful for shielding electromagnetic sources that may also generate higher order harmonics, while leaving the transmission of other frequencies unaffected.

  12. Quasi-Static Magnetic Field Shielding Using Longitudinal Mu-Near-Zero Metamaterials.

    PubMed

    Lipworth, Guy; Ensworth, Joshua; Seetharam, Kushal; Lee, Jae Seung; Schmalenberg, Paul; Nomura, Tsuyoshi; Reynolds, Matthew S; Smith, David R; Urzhumov, Yaroslav

    2015-01-01

    The control of quasi-static magnetic fields is of considerable interest in applications including the reduction of electromagnetic interference (EMI), wireless power transfer (WPT), and magnetic resonance imaging (MRI). The shielding of static or quasi-static magnetic fields is typically accomplished through the use of inherently magnetic materials with large magnetic permeability, such as ferrites, used sometimes in combination with metallic sheets and/or active field cancellation. Ferrite materials, however, can be expensive, heavy and brittle. Inspired by recent demonstrations of epsilon-, mu- and index-near-zero metamaterials, here we show how a longitudinal mu-near-zero (LMNZ) layer can serve as a strong frequency-selective reflector of magnetic fields when operating in the near-field region of dipole-like sources. Experimental measurements with a fabricated LMNZ sheet constructed from an artificial magnetic conductor - formed from non-magnetic, conducting, metamaterial elements - confirm that the artificial structure provides significantly improved shielding as compared with a commercially available ferrite of the same size. Furthermore, we design a structure to shield simultaneously at the fundamental and first harmonic frequencies. Such frequency-selective behavior can be potentially useful for shielding electromagnetic sources that may also generate higher order harmonics, while leaving the transmission of other frequencies unaffected. PMID:26234929

  13. Self-organization of frozen light in near-zero-index media with cubic nonlinearity.

    PubMed

    Marini, A; de Abajo, F J García

    2016-01-01

    Optical beams are generally unbound in bulk media, and propagate with a velocity approximately amounting to the speed of light in free-space. Guidance and full spatial confinement of light are usually achieved by means of waveguides, mirrors, resonators, and photonic crystals. Here we theoretically demonstrate that nonlinear self-organization can be exploited to freeze optical beams in bulk near-zero-index media, thus enabling three-dimensional self-trapping of still light without the need of optical resonators. Light is stopped to a standstill owing to the divergent wavelength and the vanishing group velocity, effectively rendering, through nonlinearity, a positive-epsilon trapping cavity carved in an otherwise slightly-negative-epsilon medium. By numerically solving Maxwell's equations, we find a soliton-like family of still azimuthal doughnuts, which we further study through an adiabatic perturbative theory that describes soliton evaporation in lossy media or condensation in actively pumped materials. Our results suggest applications in optical data processing and storage, quantum optical memories, and soliton-based lasers without cavities. Additionally, near-zero-index conditions can also be found in the interplanetary medium and in the atmosphere, where we provide a complementary explanation to the rare phenomenon of ball-lightning. PMID:26847877

  14. Self-organization of frozen light in near-zero-index media with cubic nonlinearity

    NASA Astrophysics Data System (ADS)

    Marini, A.; García de Abajo, F. J.

    2016-02-01

    Optical beams are generally unbound in bulk media, and propagate with a velocity approximately amounting to the speed of light in free-space. Guidance and full spatial confinement of light are usually achieved by means of waveguides, mirrors, resonators, and photonic crystals. Here we theoretically demonstrate that nonlinear self-organization can be exploited to freeze optical beams in bulk near-zero-index media, thus enabling three-dimensional self-trapping of still light without the need of optical resonators. Light is stopped to a standstill owing to the divergent wavelength and the vanishing group velocity, effectively rendering, through nonlinearity, a positive-epsilon trapping cavity carved in an otherwise slightly-negative-epsilon medium. By numerically solving Maxwell’s equations, we find a soliton-like family of still azimuthal doughnuts, which we further study through an adiabatic perturbative theory that describes soliton evaporation in lossy media or condensation in actively pumped materials. Our results suggest applications in optical data processing and storage, quantum optical memories, and soliton-based lasers without cavities. Additionally, near-zero-index conditions can also be found in the interplanetary medium and in the atmosphere, where we provide a complementary explanation to the rare phenomenon of ball-lightning.

  15. Goos-Hänchen shift of partially coherent light fields in epsilon-near-zero metamaterials.

    PubMed

    Ziauddin; Chuang, You-Lin; Qamar, Sajid; Lee, Ray-Kuang

    2016-01-01

    The Goos-Hänchen (GH) shifts in the reflected light are investigated both for p and s polarized partial coherent light beams incident on epsilon-near-zero (ENZ) metamaterials. In contrary to the coherent counterparts, the magnitude of GH shift becomes non-zero for p polarized partial coherent light beam; while GH shift can be relatively large with a small degree of spatial coherence for s polarized partial coherent beam. Dependence on the beam width and the permittivity of ENZ metamaterials is also revealed for partial coherent light fields. Our results on the GH shifts provide a direction on the applications for partial coherent light sources in ENZ metamaterials. PMID:27211050

  16. Goos-Hänchen shift of partially coherent light fields in epsilon-near-zero metamaterials

    PubMed Central

    Ziauddin; Chuang, You-Lin; Qamar, Sajid; Lee, Ray-Kuang

    2016-01-01

    The Goos-Hänchen (GH) shifts in the reflected light are investigated both for p and s polarized partial coherent light beams incident on epsilon-near-zero (ENZ) metamaterials. In contrary to the coherent counterparts, the magnitude of GH shift becomes non-zero for p polarized partial coherent light beam; while GH shift can be relatively large with a small degree of spatial coherence for s polarized partial coherent beam. Dependence on the beam width and the permittivity of ENZ metamaterials is also revealed for partial coherent light fields. Our results on the GH shifts provide a direction on the applications for partial coherent light sources in ENZ metamaterials. PMID:27211050

  17. Ultrathin and lightweight microwave absorbers made of mu-near-zero metamaterials.

    PubMed

    Zhong, Shuomin; He, Sailing

    2013-01-01

    We present a theory of perfect absorption in a bilayer model composed of a mu-near-zero (MNZ) metamaterial (MM) absorbing layer on a metallic substrate. Our analytical solutions reveal that a MM layer with a large purely imaginary permeability and a moderate permittivity backed by a metallic plane has a zero reflection at normal incidence when the thickness is ultrathin. The impedance-mismatched metamaterial absorber (MA) can be 77.3% thinner than conventional impedance-matched MAs with the same material loss in order to get the same absorption. A microwave absorber using double-layered spiral MMs with a thickness of only about one percent of the operating wavelength is designed and realized. An absorption efficiency above 93% at 1.74 GHz is demonstrated experimentally at illumination angles up to 60 degrees. Our absorber is 98% lighter than traditional microwave absorbers made of natural materials working at the same frequencies. PMID:23803861

  18. Mechanical 144 GHz beam steering with all-metallic epsilon-near-zero lens antenna

    NASA Astrophysics Data System (ADS)

    Pacheco-Peña, V.; Torres, V.; Orazbayev, B.; Beruete, M.; Navarro-Cía, M.; Sorolla, M.; Engheta, N.

    2014-12-01

    An all-metallic steerable beam antenna composed of an ɛ-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ0 = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides working just near and above the cut-off of the TE10 mode. The lens focal arc on the xz-plane is initially estimated analytically as well as numerically and compared with experimental results demonstrating good agreement. Next, a flange-ended WR-6.5 waveguide is placed along the lens focal arc to evaluate the ENZ-lens antenna steerability. A gain scan loss below 3 dB is achieved for angles up to ±15°.

  19. Epsilon-Near-Zero Modes for Tailored Light-Matter Interaction

    NASA Astrophysics Data System (ADS)

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-01

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximize the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. This design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.

  20. One-Dimensional Chirality: Strong Optical Activity in Epsilon-Near-Zero Metamaterials.

    PubMed

    Rizza, Carlo; Di Falco, Andrea; Scalora, Michael; Ciattoni, Alessandro

    2015-07-31

    We suggest that electromagnetic chirality, generally displayed by 3D or 2D complex chiral structures, can occur in 1D patterned composites whose components are achiral. This feature is highly unexpected in a 1D system which is geometrically achiral since its mirror image can always be superposed onto it by a 180 deg rotation. We analytically evaluate from first principles the bianisotropic response of multilayered metamaterials and we show that the chiral tensor is not vanishing if the system is geometrically one-dimensional chiral; i.e., its mirror image cannot be superposed onto it by using translations without resorting to rotations. As a signature of 1D chirality, we show that 1D chiral metamaterials support optical activity and we prove that this phenomenon undergoes a dramatic nonresonant enhancement in the epsilon-near-zero regime where the magnetoelectric coupling can become dominant in the constitutive relations. PMID:26274441

  1. Metamaterial-based lossy anisotropic epsilon-near-zero medium for energy collimation

    NASA Astrophysics Data System (ADS)

    Shen, Nian-Hai; Zhang, Peng; Koschny, Thomas; Soukoulis, Costas M.

    2016-06-01

    A lossy anisotropic epsilon-near-zero (ENZ) medium may lead to a counterintuitive phenomenon of omnidirectional bending-to-normal refraction [S. Feng, Phys. Rev. Lett. 108, 193904 (2012), 10.1103/PhysRevLett.108.193904], which offers a fabulous strategy for energy collimation and energy harvesting. Here, in the scope of effective medium theory, we systematically investigate two simple metamaterial configurations, i.e., metal-dielectric-layered structures and the wire medium, to explore the possibility of fulfilling the conditions of such an anisotropic lossy ENZ medium by playing with materials' parameters. Both realistic metamaterial structures and their effective medium equivalences have been numerically simulated, and the results are in excellent agreement with each other. Our study provides clear guidance and therefore paves the way towards the search for proper designs of anisotropic metamaterials for a decent effect of energy collimation and wave-front manipulation.

  2. Goos-Hänchen effect in epsilon-near-zero metamaterials

    PubMed Central

    Xu, Yadong; Chan, C. T.; Chen, Huanyang

    2015-01-01

    Light reflection and refraction at an interface between two homogeneous media is analytically described by Snell's law. For a beam with a finite waist, it turns out that the reflected wave experiences a lateral displacement from its position predicted by geometric optics. Such Goos-Hänchen (G-H) effect has been extensively investigated among all kinds of optical media, such as dielectrics, metals, photonic crystals and metamaterials. As a fundamental physics phenomenon, the G-H effect has been extended to acoustics and quantum mechanics. Here we report the unusual G-H effect in zero index metamaterials. We show that when linearly polarized light is obliquely incident from air to epsilon-near-zero metamaterials, no G-H effect could be observed for p polarized light. While for s polarization, the G-H shift is a constant value for any incident angle. PMID:25731726

  3. Design of matched zero-index metamaterials using nonmagnetic inclusions in epsilon-near-zero media

    SciTech Connect

    Silveirinha, Mario; Engheta, Nader

    2007-02-15

    In this work, we study the electrodynamics of metamaterials that consist of resonant non-magnetic inclusions embedded in an epsilon-near-zero (ENZ) host medium. It is shown that the inclusions can be designed in such a way that both the effective permittivity and permeability of the composite structure are simultaneously zero. Two different metamaterial configurations are studied and analyzed in detail. For a particular class of problems, it is analytically proven that such matched zero-index metamaterials may help improving the transmission through a waveguide bend, and that the scattering parameters may be completely independent of the specific arrangement of the inclusions and of the granularity of the crystal. The proposed concepts are numerically demonstrated at microwaves with a metamaterial realistic realization based on an artificial plasma.

  4. Dielectric nanoresonator based lossless optical perfect magnetic mirror with near-zero reflection phase

    NASA Astrophysics Data System (ADS)

    Lin, Lan; Jiang, Zhi Hao; Ma, Ding; Yun, Seokho; Liu, Zhiwen; Werner, Douglas H.; Mayer, Theresa S.

    2016-04-01

    We report an all-dielectric lossless optical mirror for the realization of controllable reflection phase based on an array of isolated dielectric nanoresonators. This dielectric mirror is comprised of a cross-shaped amorphous silicon nanoresonator array that has been designed to achieve a 99.8% reflectivity and zero reflection phase at the wavelength of 0.99 μm. The measured results from the fabricated sample match the theoretical predictions with 99.5% reflectivity and near-zero degree reflection phase at 1 μm, which is very close to the targeted wavelength. This concept and approach pave the way for synthesizing lossless artificial reflecting electromagnetic boundaries with arbitrary phase response and hold great promise in applications ranging from nanocavities to nanowaveguides and nanoantennas.

  5. Ultrathin and lightweight microwave absorbers made of mu-near-zero metamaterials

    PubMed Central

    Zhong, Shuomin; He, Sailing

    2013-01-01

    We present a theory of perfect absorption in a bilayer model composed of a mu-near-zero (MNZ) metamaterial (MM) absorbing layer on a metallic substrate. Our analytical solutions reveal that a MM layer with a large purely imaginary permeability and a moderate permittivity backed by a metallic plane has a zero reflection at normal incidence when the thickness is ultrathin. The impedance-mismatched metamaterial absorber (MA) can be 77.3% thinner than conventional impedance-matched MAs with the same material loss in order to get the same absorption. A microwave absorber using double-layered spiral MMs with a thickness of only about one percent of the operating wavelength is designed and realized. An absorption efficiency above 93% at 1.74 GHz is demonstrated experimentally at illumination angles up to 60 degrees. Our absorber is 98% lighter than traditional microwave absorbers made of natural materials working at the same frequencies. PMID:23803861

  6. Near-zero curvature fabrication of miniaturized micromechanical Ni switches using electron beam cross-linked PMMA

    NASA Astrophysics Data System (ADS)

    Teh, W. H.; Luo, J. K.; Graham, M. A.; Pavlov, A.; Smith, C. G.

    2003-09-01

    We report on the fabrication and characterization of one of the smallest near-zero curvature nickel cantilevers, acting as part of a three-terminal electrostatically actuated switch across a nanoscale gap. A surface nanomachining technique using electron beam cross-linked polymethylmethacrylate (PMMA) as the sacrificial layer combined with nickel electroplating as the structural material is developed. Sharper contact bumps were realized via reflow of PMMA resist, with tunnel junctions formed by the in situ formation of aluminium oxide during the oxygen plasma dry release step. Preliminary results show that a 0.21 µm thick plated nickel cantilever beam with dimensions of 10 µm by 4 µm suspended over a 0.43 µm gap demonstrates low hysteretic behaviour (~2.5 to 3 V) and a pull-in voltage of 27.5 V. No significant plastic deformation of the curl-free cantilevers was evident even after 1 billion switching cycles. Simple current detection techniques through a resonating cantilever-driver system are used to detect motion of the structures with resonant frequencies above 2 MHz. Because of its reliable curl-free properties, switching performance is stable and repeatable. This should pave the path towards flat nanoelectromechanical systems (NEMS) to enable both basic and applied research.

  7. Near-zero pretilt alignment of liquid crystals using polyimide films doped with UV-curable polymer.

    PubMed

    Oh, Seung-Won; Park, Jun-Hee; Yoon, Tae-Hoon

    2015-01-26

    We propose an alignment method for the near-zero pretilt angle of liquid crystals (LCs) using polyimide films doped with a UV-curable polymer. The near-zero pretilt angle can be obtained by UV curing of reactive mesogen monomers mixed with planar alignment material while a vertical electric field is applied to an LC cell assembled after the rubbing process. We demonstrated that the pretilt angle can be decreased from 2.390° to 0.082° by employing the proposed method. PMID:25835864

  8. Tunneling of obliquely incident waves through PT-symmetric epsilon-near-zero bilayers

    NASA Astrophysics Data System (ADS)

    Savoia, Silvio; Castaldi, Giuseppe; Galdi, Vincenzo; Alù, Andrea; Engheta, Nader

    2014-02-01

    We show that obliquely incident, transversely magnetic-polarized plane waves can be totally transmitted (with zero reflection) through epsilon-near-zero (ENZ) bilayers characterized by balanced loss and gain with parity-time (PT) symmetry. This tunneling phenomenon is mediated by the excitation of a surface wave localized at the interface separating the loss and gain regions. We determine the parameter configurations for which the phenomenon may occur and, in particular, the relationship between the incidence direction and the electrical thickness. We show that, below a critical threshold of gain and loss, there always exists a tunneling angle which, for moderately thick (wavelength-sized) structures, approaches a critical value dictated by the surface-wave phase-matching condition. We also investigate the unidirectional character of the tunneling phenomenon, as well as the possible onset of spontaneous symmetry breaking, typical of PT-symmetric systems. Our results constitute an interesting example of a PT-symmetry-induced tunneling phenomenon, and may open up intriguing venues in the applications of ENZ materials featuring loss and gain.

  9. Broadband Epsilon-Near-Zero Perfect Absorption in the Near-Infrared

    PubMed Central

    Yoon, Junho; Zhou, Ming; Badsha, Md. Alamgir; Kim, Tae Young; Jun, Young Chul; Hwangbo, Chang Kwon

    2015-01-01

    Perfect absorption (PA) of incident light is important for both fundamental light-matter interaction studies and practical device applications. PA studies so far have mainly used resonant nanostructures that require delicate structural patterning. Here, we realize tunable and broadband PA in the near-infrared region using relatively simple thin film coatings. We adjust the growth condition of an ITO film and control its epsilon-near-zero (ENZ) wavelength. We show that this results in highly tunable PA in the telecommunication window. Then, using an ITO multilayer of different ENZ wavelengths, we demonstrate broadband PA that covers a wide range of near-infrared wavelengths. The use of ENZ coatings makes PA adjustable during the film growth and does not require any structural patterning afterward. It also facilitates the chip-scale integration of perfect absorbers with other device components. Broadband PA relaxes the single wavelength condition in previous PA studies, and thus it is suitable for many practical device applications, including sensors, photodetectors, and energy harvesting devices. PMID:26239808

  10. Manipulating polarization of light with ultrathin epsilon-near-zero metamaterials.

    PubMed

    Ginzburg, P; Rodríguez Fortuño, F J; Wurtz, G A; Dickson, W; Murphy, A; Morgan, F; Pollard, R J; Iorsh, I; Atrashchenko, A; Belov, P A; Kivshar, Y S; Nevet, A; Ankonina, G; Orenstein, M; Zayats, A V

    2013-06-17

    One of the basic functionalities of photonic devices is the ability to manipulate the polarization state of light. Polarization components are usually implemented using the retardation effect in natural birefringent crystals and, thus, have a bulky design. Here, we have demonstrated the polarization manipulation of light by employing a thin subwavelength slab of metamaterial with an extremely anisotropic effective permittivity tensor. Polarization properties of light incident on the metamaterial in the regime of hyperbolic, epsilon-near-zero, and conventional elliptic dispersions were compared. We have shown that both reflection from and transmission through λ/20 thick slab of the metamaterial may provide nearly complete linear-to-circular polarization conversion or 90° linear polarization rotation, not achievable with natural materials. Using ellipsometric measurements, we experimentally studied the polarization conversion properties of the metamaterial slab made of the plasmonic nanorod arrays in different dispersion regimes. We have also suggested all-optical ultrafast control of reflected or transmitted light polarization by employing metal nonlinearities. PMID:23787679

  11. Perfect imaging, epsilon-near zero phenomena and waveguiding in the scope of nonlocal effects

    PubMed Central

    David, C.; Mortensen, N. A.; Christensen, J.

    2013-01-01

    Plasmons in metals can oscillate on a sub-wavelength length scale and this large-k response constitutes an inherent prerequisite for fascinating effects such as perfect imaging and intriguing wave phenomena associated with the epsilon-near-zero (ENZ) regime. While there is no upper cut-off within the local-response approximation (LRA) of the plasma polarization, nonlocal dynamics suppress response beyond ω/vF, where vF is the Fermi velocity of the electron gas. Nonlocal response has previously been found to pose limitations to field-enhancement phenomena. Accounting for nonlocal hydrodynamic response, we show that perfect imaging is surprisingly only marginally affected by nonlocal properties of a metal slab, even for a deep subwavelength case and an extremely thin film. Similarly, for the ENZ response we find no indications of nonlocal response jeopardizing the basic behaviors anticipated from the LRA. Finally, our study of waveguiding of gap plasmons even shows a positive nonlocal influence on the propagation length. PMID:23982271

  12. Epsilon-near-zero modes for tailored light-matter interaction

    DOE PAGESBeta

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-20

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximizemore » the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.« less

  13. Epsilon-near-zero modes for tailored light-matter interaction

    SciTech Connect

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-20

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximize the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.

  14. Zoned near-zero refractive index fishnet lens antenna: Steering millimeter waves

    SciTech Connect

    Pacheco-Peña, V. Orazbayev, B. Beaskoetxea, U. Beruete, M.; Navarro-Cía, M.

    2014-03-28

    A zoned fishnet metamaterial lens is designed, fabricated, and experimentally demonstrated at millimeter wavelengths to work as a negative near-zero refractive index lens suitable for compact lens antenna configurations. At the design frequency f = 56.7 GHz (λ{sub 0} = 5.29 mm), the zoned fishnet metamaterial lens, designed to have a focal length FL = 9λ{sub 0}, exhibits a refractive index n = −0.25. The focusing performance of the diffractive optical element is briefly compared with that of a non-zoned fishnet metamaterial lens and an isotropic homogeneous zoned lens made of a material with the same refractive index. Experimental and numerically-computed radiation diagrams of the fabricated zoned lens are presented and compared in detail with that of a simulated non-zoned lens. Simulation and experimental results are in good agreement, demonstrating an enhancement generated by the zoned lens of 10.7 dB, corresponding to a gain of 12.26 dB. Moreover, beam steering capability of the structure by shifting the feeder on the xz-plane is demonstrated.

  15. HVAC Equipment Design Options for Near-Zero-Energy Homes (NZEH) -A Stage 2 Scoping Assessment

    SciTech Connect

    Baxter, Van D

    2005-11-01

    Although the energy efficiency of heating, ventilating, and air-conditioning (HVAC) equipment has increased substantially in recent years, new approaches are needed to continue this trend. Conventional unitary equipment and system designs have matured to a point where cost-effective, dramatic efficiency improvements that meet near-zero-energy housing (NZEH) goals require a radical rethinking of opportunities to improve system performance. The large reductions in HVAC energy consumption necessary to support the NZEH goals require a systems-oriented analysis approach that characterizes each element of energy consumption, identifies alternatives, and determines the most cost-effective combination of options. In particular, HVAC equipment must be developed that addresses the range of special needs of NZEH applications in the areas of reduced HVAC and water heating energy use, humidity control, ventilation, uniform comfort, and ease of zoning. This report describes results of a scoping assessment of HVAC system options for NZEH homes. ORNL has completed a preliminary adaptation, for consideration by The U.S. Department of Energy, Energy Efficiency and Renewable Energy Office, Building Technologies (BT) Program, of Cooper's (2001) stage and gate planning process to the HVAC and Water Heating element of BT's multi-year plan, as illustrated in Figure 1. In order to adapt to R&D the Cooper process, which is focused on product development, and to keep the technology development process consistent with an appropriate role for the federal government, the number and content of the stages and gates needed to be modified. The potential federal role in technology development involves 6 stages and 7 gates, but depending on the nature and status of the concept, some or all of the responsibilities can flow to the private sector for product development beginning as early as Gate 3. In the proposed new technology development stage and gate sequence, the Stage 2 'Scoping Assessment

  16. Three-dimensionally bonded spongy graphene material with super compressive elasticity and near-zero Poisson's ratio.

    PubMed

    Wu, Yingpeng; Yi, Ningbo; Huang, Lu; Zhang, Tengfei; Fang, Shaoli; Chang, Huicong; Li, Na; Oh, Jiyoung; Lee, Jae Ah; Kozlov, Mikhail; Chipara, Alin C; Terrones, Humberto; Xiao, Peishuang; Long, Guankui; Huang, Yi; Zhang, Fan; Zhang, Long; Lepró, Xavier; Haines, Carter; Lima, Márcio Dias; Lopez, Nestor Perea; Rajukumar, Lakshmy P; Elias, Ana L; Feng, Simin; Kim, Seon Jeong; Narayanan, N T; Ajayan, Pulickel M; Terrones, Mauricio; Aliev, Ali; Chu, Pengfei; Zhang, Zhong; Baughman, Ray H; Chen, Yongsheng

    2015-01-01

    It is a challenge to fabricate graphene bulk materials with properties arising from the nature of individual graphene sheets, and which assemble into monolithic three-dimensional structures. Here we report the scalable self-assembly of randomly oriented graphene sheets into additive-free, essentially homogenous graphene sponge materials that provide a combination of both cork-like and rubber-like properties. These graphene sponges, with densities similar to air, display Poisson's ratios in all directions that are near-zero and largely strain-independent during reversible compression to giant strains. And at the same time, they function as enthalpic rubbers, which can recover up to 98% compression in air and 90% in liquids, and operate between -196 and 900 °C. Furthermore, these sponges provide reversible liquid absorption for hundreds of cycles and then discharge it within seconds, while still providing an effective near-zero Poisson's ratio. PMID:25601131

  17. Improved production of Br atoms near zero speed by photodissociating laser aligned Br{sub 2} molecules

    SciTech Connect

    Deng, L. Z. Yin, J. P.

    2014-10-28

    We theoretically investigated the improvement on the production rate of the decelerated bromine (Br) atoms near zero speed by photodissociating laser aligned Br{sub 2} precursors. Adiabatic alignment of Br{sub 2} precursors exposed to long laser pulses with duration on the order of nanoseconds was investigated by solving the time-dependent Schrödinger equation. The dynamical fragmentation of adiabatically aligned Br{sub 2} precursors was simulated and velocity distribution of the Br atoms produced was analyzed. Our study shows that the larger the degree of the precursor alignment, 〈cos{sup 2} θ〉, the higher the production rate of the decelerated Br atoms near zero speed. For Br{sub 2} molecules with an initial rotational temperature of ∼1 K, a 〈cos{sup 2} θ〉 value of ∼0.88 can result in an improvement factor of over ∼20 on the production rate of the decelerated Br atoms near zero speed, requiring a laser intensity of only ∼1 × 10{sup 12} W/cm{sup 2} for alignment.

  18. Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes - Business Case Assessment

    SciTech Connect

    Baxter, Van D

    2007-05-01

    . Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft{sup 2} houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, 'HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment', ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. Table 1 summarizes the energy savings potential of the highest scoring options from the 2005 study for all five locations. All system options were scored by the ORNL building equipment research team and by William Goetzler of Navigant Consulting. These scores were reviewed by DOE/BT's Residential Integration program leaders and Building America team members. Based on these results, the two centrally ducted integrated heat pump (IHP) systems (air source and ground source versions) were selected for advancement to Stage 2 (Exploratory Development) business case assessments in FY06. This report describes results of these business case assessments. It is a compilation of three separate reports describing the initial business case study (Baxter 2006a), an update to evaluate the impact of an economizer cooling option (Baxter 2006b), and a second update to evaluate the impact of a winter humidification option (Baxter 2007). In addition it

  19. Solute partitioning in multi-component γ/γ' Co–Ni-base superalloys with near-zero lattice misfit

    DOE PAGESBeta

    Meher, S.; Carroll, L. J.; Pollock, T. M.; Carroll, M. C.

    2015-11-21

    The addition of nickel to cobalt-base alloys enables alloys with a near zero γ – γ' lattice misfit. The solute partitioning between ordered γ' precipitates and the disordered γ matrix have been investigated using atom probe tomography. Lastly, the unique shift in solute partitioning in these alloys, as compared to that in simpler Co-base alloys, derives from changes in site substitution of solutes as the relative amounts of Co and Ni change, highlighting new opportunities for the development of advanced tailored alloys.

  20. Quantitation of Bone Growth Rate Variability in Rats Exposed to Micro-(near zero G) and Macrogravity (2G)

    NASA Technical Reports Server (NTRS)

    Bromage, Timothy G.; Doty, Stephen B.; Smolyar, Igor; Holton, Emily

    1997-01-01

    Our stated primary objective is to quantify the growth rate variability of rat lamellar bone exposed to micro- (near zero G: e.g., Cosmos 1887 & 2044; SLS-1 & SLS-2) and macrogravity (2G). The primary significance of the proposed work is that an elegant method will be established that unequivocally characterizes the morphological consequences of gravitational factors on developing bone. The integrity of this objective depends upon our successful preparation of thin sections suitable for imaging individual bone lamellae, and our imaging and quantitation of growth rate variability in populations of lamellae from individual bone samples.

  1. T300HoneySiC: a new near-zero CTE molded C/SiC material

    NASA Astrophysics Data System (ADS)

    Goodman, William A.; Ghasemi Nejhad, Mehrdad N.; Wright, Stan; Welson, Darren

    2015-09-01

    Using an Additive Manufacturing process, Trex Enterprises and teammates were successful in producing a 12-inch by 12-inch by 0.5-inch vented, lightweight, Honeycomb C/SiC ceramic matrix composite (CMC) panel which had a density relative to bulk silicon carbide of 11% (89% lightweighting). The so-called T300HoneySiC™ panel and facesheet stock material were fabricated into ASTM standard coupons and tested at Southern Research Institute to obtain basic materials properties data. The material properties data showed that we had made a near-zero coefficient of thermal expansion (CTE= -0.22 ppm/°C from -196°C to +24°C) CMC C/SiC material with good strength. This material will be ideal for space opto-mechanical structures and optical benches due to its near-zero CTE and light weight. The material is initially molded and then converted to a C/SiC ceramic matrix composite, thus the fabrication time can be less than 3 weeks from start to finish, resulting in low cost.

  2. Supercontinuum generation in square photonic crystal fiber with nearly zero ultra-flattened chromatic dispersion and fabrication tolerance analysis

    NASA Astrophysics Data System (ADS)

    Begum, Feroza; Namihira, Yoshinori; Kinjo, Tatsuya; Kaijage, Shubi

    2011-02-01

    This paper presents a simple index-guiding square photonic crystal fiber (SPCF) where the core is surrounded by air holes with two different diameters. The proposed design is simulated through an efficient full-vector modal solver based on the finite difference method with anisotropic perfectly matched layers absorbing boundary condition. The nearly zero ultra-flattened dispersion SPCF with low confinement loss, small effective area as well as broadband supercontinuum (SC) spectra is targeted. Numerical results show that the designed SPCF has been achieved at a nearly zero ultra-flattened dispersion of 0 ± 0.25 ps/(nm·km) in a wavelength range of 1.38 μm to 1.89 μm (510 nm band) which covers E, S, C, L and U communication bands, a low confinement loss of less than 10 -7 dB/m in a wavelength range of 1.3 μm to 2.0 μm and a wide SC spectrum (FWHM = 450 nm) by using picosecond pulses at a center wavelength of 1.55 μm. We then analyze the sensitivity of chromatic dispersion to small variations from the optimum value of specific structural parameters. The proposed index-guiding SPCF can be applicable in supercontinuum generation (SCG) covering such diverse fields as spectroscopy applications and telecommunication dense wavelength division multiplexing (DWDM) sources.

  3. LASER STABILIZATION FOR NEAR ZERO NO{sub x} GAS TURBINE COMBUSTION SYSTEMS

    SciTech Connect

    Vivek Khanna

    2002-09-30

    Historically, the development of new industrial gas turbines has been primarily driven by the intent to achieve higher efficiency, lower operating costs and lower emissions. Higher efficiency and lower cost is obtained through higher turbine operating temperatures, while reduction in emissions is obtained by extending the lean operating limit of the combustor. However reduction in the lean stability limit of operation is limited greatly by the chemistry of the combustion process and by the occurrence of thermo-acoustic instabilities. Solar Turbines, CFD Research Corporation, and Los Alamos National Laboratory have teamed to advance the technology associated with laser-assisted ignition and flame stabilization, to a level where it could be incorporated onto a gas turbine combustor. The system being developed is expected to enhance the lean stability limit of the swirl stabilized combustion process and assist in reducing combustion oscillations. Such a system has the potential to allow operation at the ultra-lean conditions needed to achieve NO{sub x} emissions below 5 ppm without the need of exhaust treatment or catalytic technologies. The research effort was focused on analytically modeling laser-assisted flame stabilization using advanced CFD techniques, and experimentally demonstrating the technology, using a solid-state laser and low-cost durable optics. A pulsed laser beam was used to generate a plasma pool at strategic locations within the combustor flow field such that the energy from the plasma became an ignition source and helped maintain a flame at ultra lean operating conditions. The periodic plasma generation and decay was used to nullify the fluctuations in the heat release from the flame itself, thus decoupling the heat release from the combustor acoustics and effectively reducing the combustion oscillations. The program was built on an existing technology base and includes: extending LANL's existing laser stabilization experience to a sub

  4. Large optical nonlinearity of indium tin oxide in its epsilon-near-zero region.

    PubMed

    Alam, M Zahirul; De Leon, Israel; Boyd, Robert W

    2016-05-13

    Nonlinear optical phenomena are crucial for a broad range of applications, such as microscopy, all-optical data processing, and quantum information. However, materials usually exhibit a weak optical nonlinearity even under intense coherent illumination. We report that indium tin oxide can acquire an ultrafast and large intensity-dependent refractive index in the region of the spectrum where the real part of its permittivity vanishes. We observe a change in the real part of the refractive index of 0.72 ± 0.025, corresponding to 170% of the linear refractive index. This change in refractive index is reversible with a recovery time of about 360 femtoseconds. Our results offer the possibility of designing material structures with large ultrafast nonlinearity for applications in nanophotonics. PMID:27127238

  5. Pichia pastoris Exhibits High Viability and a Low Maintenance Energy Requirement at Near-Zero Specific Growth Rates

    PubMed Central

    Rebnegger, Corinna; Vos, Tim; Graf, Alexandra B.; Valli, Minoska; Pronk, Jack T.

    2016-01-01

    ABSTRACT The yeast Pichia pastoris is a widely used host for recombinant protein production. Understanding its physiology at extremely low growth rates is a first step in the direction of decoupling product formation from cellular growth and therefore of biotechnological relevance. Retentostat cultivation is an excellent tool for studying microbes at extremely low specific growth rates but has so far not been implemented for P. pastoris. Retentostat feeding regimes were based on the maintenance energy requirement (mS) and maximum biomass yield on glucose (YX/Smax) estimated from steady-state glucose-limited chemostat cultures. Aerobic retentostat cultivation enabled reproducible, smooth transitions from a specific growth rate (μ) of 0.025 h−1 to near-zero specific growth rates (μ < 0.001 h−1). At these near-zero specific growth rates, viability remained at least 97%. The value of mS at near-zero growth rates was 3.1 ± 0.1 mg glucose per g biomass and h, which was 3-fold lower than the mS estimated from faster-growing chemostat cultures. This difference indicated that P. pastoris reduces its maintenance energy requirement at extremely low μ, a phenomenon not previously observed in eukaryotes. Intracellular levels of glycogen and trehalose increased, while μ progressively declined during retentostat cultivation. Transcriptional reprogramming toward zero growth included the upregulation of many transcription factors as well as stress-related genes and the downregulation of cell cycle genes. This study underlines the relevance of comparative analysis of maintenance energy metabolism, which has an important impact on large-scale industrial processes. IMPORTANCE The yeast Pichia pastoris naturally lives on trees and can utilize different carbon sources, among them glucose, glycerol, and methanol. In biotechnology, it is widely used for the production of recombinant proteins. For both the understanding of life in its natural habitat and optimized production

  6. Gain assisted nanocomposite multilayers with near zero permittivity modulus at visible frequencies

    NASA Astrophysics Data System (ADS)

    Rizza, Carlo; Di Falco, Andrea; Ciattoni, Alessandro

    2011-11-01

    We have fabricated a nano-laminate by alternating metal and gain medium layers, the gain dielectric consisting of a polymer incorporating optically pumped dye molecules. From standard reflection-transmission experiments, we show that, at a visible wavelength, both the real and the imaginary parts of the permittivity ɛ∥ attain very small values and we measure, at λ = 604 nm, |ɛ∥|=0.04 which is 21.5% smaller than its value in the absence of optical pumping. Our investigation thus proves that a medium with a permittivity with very small modulus, a key condition promising efficient subwavelength optical steering, can be actually synthesized.

  7. Compact transformable acoustic logic gates for broadband complex Boolean operations based on density-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Cheng, Ying; Yuan, Bao-Guo; Guo, Jian-Zhong; Liu, Xiao-Jun

    2016-05-01

    The extraordinary transmission in density-near-zero (DNZ) acoustic metamaterials (AMs) provides possibilities to manipulate acoustic signals with extremely large effective phase velocity and wavelength. Here, we report compact transformable acoustic logic gates with a subwavelength size as small as 0.82λ based on DNZ AMs. The basic acoustic logic gates, composed of a tri-port structure filled with space-coiling DNZ AMs, enable precise direct linear interference of input signals with considerably small phase lag and wavefront distortion. We demonstrate both theoretically and experimentally the basic Boolean logic operations such as OR, AND, XOR, and NOT with wide operational frequency ranges and controllability, by adjusting the phase difference between two input signals. More complex logic calculus, such as "I1 + I2 × I3," are also realized by cascading of the basic logic gates. Our proposal provides diverse routes to construct devices for acoustic signal computing and manipulations.

  8. Mechanical 144 GHz beam steering with all-metallic epsilon-near-zero lens antenna

    SciTech Connect

    Pacheco-Peña, V. Torres, V. Orazbayev, B. Beruete, M. Sorolla, M.; Navarro-Cía, M.; Engheta, N.

    2014-12-15

    An all-metallic steerable beam antenna composed of an ε-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ{sub 0} = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides working just near and above the cut-off of the TE{sub 10} mode. The lens focal arc on the xz-plane is initially estimated analytically as well as numerically and compared with experimental results demonstrating good agreement. Next, a flange-ended WR-6.5 waveguide is placed along the lens focal arc to evaluate the ENZ-lens antenna steerability. A gain scan loss below 3 dB is achieved for angles up to ±15°.

  9. Momentum Distribution of Near-Zero-Energy Photoelectrons in the Strong-Field Tunneling Ionization in the Long Wavelength Limit

    PubMed Central

    Xia, Q. Z.; Ye, D. F.; Fu, L. B.; Han, X. Y.; Liu, J.

    2015-01-01

    We investigate the ionization dynamics of Argon atoms irradiated by an ultrashort intense laser of a wavelength up to 3100 nm, addressing the momentum distribution of the photoelectrons with near-zero-energy. We find a surprising accumulation in the momentum distribution corresponding to meV energy and a “V”-like structure at the slightly larger transverse momenta. Semiclassical simulations indicate the crucial role of the Coulomb attraction between the escaping electron and the remaining ion at an extremely large distance. Tracing back classical trajectories, we find the tunneling electrons born in a certain window of the field phase and transverse velocity are responsible for the striking accumulation. Our theoretical results are consistent with recent meV-resolved high-precision measurements. PMID:26081971

  10. Experimental study of Rabi-type oscillation induced by tunneling modes in effective near-zero-index metamaterials.

    PubMed

    Zhang, Liwei; Zhang, Yewen; Yang, Yaping; Chen, Hong

    2011-04-01

    A special cavity based on effective near-zero-index paired structures containing ɛ-negative and μ-negative materials is realized by using composite right- or left-handed transmission lines. When an artificial magnetic "atom" is put into the cavity, unusual Rabi-type splitting appears because of the strong coupling between the artificial atom and the localized tunneling mode. The direct time domain energy exchanges between the cavity and the "atom" are experimentally observed after excited by a short pulse signal. Within the "atom" field attenuation time, more than one oscillations appear. Rabi-type splitting and the Rabi-type oscillation period are invariant with the scaling changes of the length but vary with the positions where the "atom" is put with different field intensity. Moreover, the decay time of Rabi-type oscillation becomes longer when the tunneling mode possesses smaller linewidth, which is in good agreement with numerical simulations. PMID:21599323

  11. Transmission-line analysis of an Epsilon Near Zero tunneling circuit using a double ridge rectangular waveguide

    NASA Astrophysics Data System (ADS)

    Kim, Byung-Mun; Son, Hyeok-Woo; Cho, Young-Ki; Hong, Jae-Pyo

    2014-09-01

    We present a simple method for efficient modeling of the tunneling effect in an Epsilon Near Zero (ENZ) channel waveguide based on a transmission-line model. The proposed ENZ channel uses a double-ridge rectangular waveguide (RWG) and is located in the middle of the input-output standard rectangular waveguides (IORWG). The height of the channel waveguide is much smaller than that of the IORWG. The detailed design of the ENZ channel is presented, and the optimum length for tunneling phenomena is calculated. These theoretical studies highlight the substantial differences between this unique tunneling phenomenon and higher-frequency Fabry-Perot resonances. We perform a simulation for the designed ENZ channel by using a commercial FEM simulator. The simulated and the measured results for the fabricated ENZ channel structure are in good agreement.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Near-infrared strong coupling between metamaterials and epsilon-near-zero modes in degenerately doped semiconductor nanolayers

    DOE PAGESBeta

    Campione, Salvatore; Wendt, Joel R.; Keeler, Gordon Arthur; Luk, Ting S.

    2016-01-14

    Epsilon-near-zero (ENZ) modes provide a new path for tailoring light–matter interactions at the nanoscale. In this paper, we analyze a strongly coupled system at near-infrared frequencies comprising plasmonic metamaterial resonators and ENZ modes supported by degenerately doped semiconductor nanolayers. In strongly coupled systems that combine optical cavities and intersubband transitions, the polariton splitting (i.e., the ratio of Rabi frequency to bare cavity frequency) scales with the square root of the wavelength, thus favoring the long-wavelength regime. In contrast, we observe that the polariton splitting in ENZ/metamaterial resonator systems increases linearly with the thickness of the nanolayer supporting the ENZ modes.more » In this work, we employ an indium-tin-oxide nanolayer and observe a large experimental polariton splitting of approximately 30% in the near-infrared. As a result, this approach opens up many promising applications, including nonlinear optical components and tunable optical filters based on controlling the polariton splitting by adjusting the frequency of the ENZ mode.« less

  14. Broadband zero-backward and near-zero-forward scattering by metallo-dielectric core-shell nanoparticles

    PubMed Central

    Li, Yan; Wan, Mingjie; Wu, Wenyang; Chen, Zhuo; Zhan, Peng; Wang, Zhenlin

    2015-01-01

    Efficient control of optical radiation at subwavelength scales plays important roles for various applications. Dielectric nanoparticles or dielectric shells with a large refractive index of n ~ 3–4, which are only achievable for limited semiconductors, are involved in most designs so far to control the scattering by overlapping the electric and magnetic dipolar modes of the same magnitude. Here we propose a new mechanism based on the interplay between dipolar and quadrupolar resonances of different amplitudes, both magnetic and electric, to suppress the backward scattering or the forward scattering by using metallo-dielectric core-shell nanoparticles with a dielectric shell layer having a refractive index of n = 2.0. We demonstrate that broadband zero-backward or near-zero-forward scattering can be achieved by optimizing the structural parameters. We also demonstrate that the core-shell nanoparticles with identical dielectric shells but metal cores with various sizes are able to suppress the backward or forward scattering at the same wavelength, thus revealing a large tolerance to fabrication errors induced by the size distributions in the metal cores. These features make the proposed core-shell nanoparticles beyond the dipole limit more easily realized in practical experiments. PMID:26282896

  15. Near-infrared strong coupling between metamaterials and epsilon-near-zero modes in degenerately doped semiconductor nanolayers

    SciTech Connect

    Campione, Salvatore; Wendt, Joel R.; Keeler, Gordon Arthur; Luk, Ting S.

    2016-01-01

    Epsilon-near-zero (ENZ) modes provide a new path for tailoring light–matter interactions at the nanoscale. In this paper, we analyze a strongly coupled system at near-infrared frequencies comprising plasmonic metamaterial resonators and ENZ modes supported by degenerately doped semiconductor nanolayers. In strongly coupled systems that combine optical cavities and intersubband transitions, the polariton splitting (i.e., the ratio of Rabi frequency to bare cavity frequency) scales with the square root of the wavelength, thus favoring the long-wavelength regime. In contrast, we observe that the polariton splitting in ENZ/metamaterial resonator systems increases linearly with the thickness of the nanolayer supporting the ENZ modes. In this work, we employ an indium-tin-oxide nanolayer and observe a large experimental polariton splitting of approximately 30% in the near-infrared. As a result, this approach opens up many promising applications, including nonlinear optical components and tunable optical filters based on controlling the polariton splitting by adjusting the frequency of the ENZ mode.

  16. Composite material made of plasmonic nanoshells with quantum dot cores: loss-compensation and ε-near-zero physical properties.

    PubMed

    Campione, Salvatore; Capolino, Filippo

    2012-06-15

    A theoretical investigation of loss-compensation capabilities in composite materials made of plasmonic nanoshells is carried out by considering quantum dots (QDs) as the nanoshells' cores. The QD and metal permittivities are modeled according to published experimental data. We determine the modes with real or complex wavenumber able to propagate in a 3D periodic lattice of nanoshells. Mode analysis is also used to assess that only one propagating mode is dominant in the composite material whose optical properties can hence be described via homogenization theory. Therefore, the material effective permittivity is found by comparing different techniques: (i) the mentioned mode analysis, (ii) Maxwell Garnett mixing rule and (iii) the Nicolson-Ross-Weir method based on transmission and reflection when considering a metamaterial of finite thickness. The three methods are in excellent agreement, because the nanoshells considered in this paper are very subwavelength, thus justifying the parameter homogenization. We show that QDs are able to provide loss-compensated ε-near-zero metamaterials and also loss-compensated metamaterials with large negative values of permittivity. Besides compensating for losses, the strong gain via QD can provide optical amplification with particular choices of the nanoshell and lattice dimensions. PMID:22595780

  17. Detection of Intracellular Selenol-Containing Molecules Using a Fluorescent Probe with Near-Zero Background Signal.

    PubMed

    Sun, Qi; Yang, Shu-Hou; Wu, Lei; Dong, Qing-Jian; Yang, Wen-Chao; Yang, Guang-Fu

    2016-06-01

    Selenocysteine (Sec), encoded as the 21st amino acid, is the predominant chemical form of selenium that is closely related to various human diseases. Thus, it is of high importance to identify novel probes for sensitive and selective recognition of Sec and Sec-containing proteins. Although a few probes have been reported to detect artificially introduced selenols in cells or tissues, none of them has been shown to be sensitive enough to detect endogenous selenols. We report the characterization and application of a new fluorogenic molecular probe for the detection of intracellular selenols. This probe exhibits near-zero background fluorescence but produces remarkable fluorescence enhancement upon reacting with selenols in a fast chemical reaction. It is highly specific and sensitive for intracellular selenium-containing molecules such as Sec and selenoproteins. When combined with flow cytometry, this probe is able to detect endogenous selenols in various human cancer cells. It is also able to image endogenous selenol-containing molecules in zebrafish under a fluorescence microscope. These results demonstrate that this molecular probe can function as a useful molecular tool for intracellular selenol sensing, which is valuable in the clinical diagnosis for human diseases associated with Sec-deficiency or overdose. PMID:27161304

  18. Graphene-dielectric composite metamaterials: evolution from elliptic to hyperbolic wavevector dispersion and the transverse epsilon-near-zero condition

    NASA Astrophysics Data System (ADS)

    Othman, Mohamed A. K.; Guclu, Caner; Capolino, Filippo

    2013-01-01

    We investigated a multilayer graphene-dielectric composite material, comprising graphene sheets separated by subwavelength-thick dielectric spacer, and found it to exhibit hyperbolic isofrequency wavevector dispersion at far- and mid-infrared frequencies, allowing propagation of waves that would be otherwise evanescent in an isotropic dielectric. Electrostatic biasing was considered for tunable and controllable transition from hyperbolic to elliptic dispersion. We explored the validity and limitation of the effective medium approximation (EMA) for modeling wave propagation and cutoff of the propagating spatial spectrum due to the Brillouin zone edge. We reported that EMA is capable of predicting the transition of the isofrequency dispersion diagram under certain conditions. The graphene-based composite material allows propagation of backward waves under the hyperbolic dispersion regime and of forward waves under the elliptic regime. Transition from hyperbolic to elliptic dispersion regimes is governed by the transverse epsilon-near-zero (TENZ) condition, which implies a flatter and wider propagating spectrum with higher attenuation, when compared to the hyperbolic regime. We also investigated the wide-angle tunable transparency of the multilayer at that condition in contrast to other materials exhibiting ENZ phenomena.

  19. Analysis of extremal lift behavior of a semicircular airfoil in a turbulent airflow at a near-zero angle of attack

    NASA Astrophysics Data System (ADS)

    Isaev, S. A.; Miau, J.-J.; Sudakov, A. G.; Usachov, A. E.

    2015-08-01

    The experimentally discovered phenomenon of lift drop for a semicircular airfoil in a turbulent airflow at a near-zero angle of attack has been numerically analyzed with multiblock computational technologies using a shear-stress-transfer model modified with allowance for the curvature of flow lines.

  20. 40 CFR Appendix C to Part 72 - Actual 1985 Yearly SO2 Emissions Calculation

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. C Appendix C to Part 72—Actual 1985 Yearly SO2... = (coal SO2 emissions) + (oil SO2 emissions) (in tons) If gas is the only fuel, gas emissions...

  1. Alternate-Fueled Combustor-Sector Performance: Part A: Combustor Performance Part B: Combustor Emissions

    NASA Technical Reports Server (NTRS)

    Shouse, D. T.; Neuroth, C.; Henricks, R. C.; Lynch, A.; Frayne, C.; Stutrud, J. S.; Corporan, E.; Hankins, T.

    2010-01-01

    Alternate aviation fuels for military or commercial use are required to satisfy MIL-DTL-83133F(2008) or ASTM D 7566 (2010) standards, respectively, and are classified as drop-in fuel replacements. To satisfy legacy issues, blends to 50% alternate fuel with petroleum fuels are certified individually on the basis of feedstock. Adherence to alternate fuels and fuel blends requires smart fueling systems or advanced fuel-flexible systems, including combustors and engines without significant sacrifice in performance or emissions requirements. This paper provides preliminary performance (Part A) and emissions and particulates (Part B) combustor sector data for synthetic-parafinic-kerosene- (SPK-) type fuel and blends with JP-8+100 relative to JP-8+100 as baseline fueling.

  2. Automatic robotic arm operations and sampling in near zero gravity environment - functional tests results from Phobos-Grunt mission

    NASA Astrophysics Data System (ADS)

    Kozlova, Tatiana; Karol Seweryn, D..; Grygorczuk, Jerzy; Kozlov, Oleg

    sampling; (ii) technical characteristics of both devices, i.e. progress cycles of CHOMIK device in different materials and torque in the manipulator joints during sampling operations; (iii) confirmation of applicability of both devices to perform such type of tasks. The phases in operational scenario were prepared to meet mission and system requirements mainly connected with: (i) environment (near zero gravity, vacuum, dust), (ii) safety and (iii) to avoid common operation of both devices at the same time.

  3. Gain and bandwidth investigation in a near-zero ultra-flat dispersion PCF for optical parametric amplification around the communication wavelength.

    PubMed

    Maji, Partha Sona; Chaudhuri, Partha Roy

    2015-04-10

    In this work, we explore the fiber optical parametric amplifiers (FOPAs) gain and bandwidth spectra of near-zero ultra-flattened photonic crystal fibers (PCFs) around the communication wavelength. The parametric gain and spectral bandwidth have been explored for all the three zero-dispersion wavelengths (ZDWs) of the near-zero ultra-flat fiber. Our numerical analysis establishes a dispersion profile with D=0±0.35  ps/nm/km for a bandwidth of 440 nm around the communication wavelength to fully exploit the four-wave mixing effect with three ZDWs for broadband applications. It has been observed that the broader gain spectrum of FOPAs can be achieved with the near-zero and ultra-flattened dispersion curve with proper tuning of the pumping condition. A broader bandwidth with sufficient peak gain value has been achieved with small negative anomalous dispersion (β2≤0) and positive value of fourth-order dispersion parameter (+ve  β4) around the pumping wavelength. Wider bandwidth of the parametric amplifier has been observed around the second ZDW with a negative slope of the dispersion curve. A total bandwidth ≈520  nm could be achieved with the ultra-flat dispersion nature of the optimized PCF. The design methodology of achieving wider gain by tuning the pumping wavelength for favorable higher-order dispersion parameters would be very useful for future dispersion engineered devices. PMID:25967312

  4. Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes

    SciTech Connect

    Baxter, Van D

    2006-11-01

    . Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft{sup 2} houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, 'HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment,' ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. Table 1 summarizes the energy savings potential of the highest scoring options from the 2005 study for all five locations.

  5. 40 CFR Appendix I to Part 1068 - Emission-Related Components

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Emission-Related Components I Appendix... Appendix I to Part 1068—Emission-Related Components This appendix specifies emission-related components that we refer to for describing such things as emission-related warranty or requirements related...

  6. 40 CFR Appendix I to Part 1068 - Emission-Related Components

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Emission-Related Components I Appendix... Appendix I to Part 1068—Emission-Related Components This appendix specifies emission-related components that we refer to for describing such things as emission-related warranty or requirements related...

  7. 40 CFR Appendix I to Part 1068 - Emission-Related Components

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Emission-Related Components I Appendix... Appendix I to Part 1068—Emission-Related Components This appendix specifies emission-related components that we refer to for describing such things as emission-related warranty or requirements related...

  8. The Fano-type transmission and field enhancement in heterostructures composed of epsilon-near-zero materials and truncated photonic crystals

    SciTech Connect

    Zhang, Zhi-fang; Jiang, Hai-tao E-mail: jiang-haitao@tongji.edu.cn; Li, Yun-hui; Chen, Hong; Xue, Chun-hua E-mail: jiang-haitao@tongji.edu.cn; Lu, Hai

    2013-11-11

    The Fano-type interference effect is studied in the heterostructure composed of an epsilon-near-zero (ENZ) material and a truncated photonic crystal for transverse magnetic polarized light. In the Fano-type interference effect, the ENZ material provides narrow reflection pathway and the photonic crystal provides broadband reflection pathway. The boundary condition across the ENZ interface and the confinement effect provided by the photonic crystal can enhance the electric fields in the ENZ material greatly. The field enhancements, together with the asymmetric property of Fano-type spectrum, possess potential applications for significantly lowering the threshold of nonlinear processes such as optical switching and bistability.

  9. REVIEW OF INDOOR EMISSION SOURCE MODELS--PART 1. OVERVIEW

    EPA Science Inventory

    Indoor emission source models are mainly used as a component in indoor air quality (IAQ) and exposure modeling. They are also widely used to interpret the experimental data obtained from environmental chambers and buildings. This paper compiles 46 indoor emission source models fo...

  10. 40 CFR Appendix I to Part 1042 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Tier 1 standards. NOX emissions from model year 2004 and later engines with displacement of 2.5 or more... CFR part 89 and summarized in the following table: Table 1 to Appendix I—Emission Standards for...-exceed emission standards specified in 40 CFR 94.8(e) apply for all engines subject to the Tier...

  11. 40 CFR Appendix I to Part 1042 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Tier 1 standards. NOX emissions from model year 2004 and later engines with displacement of 2.5 or more... CFR part 89 and summarized in the following table: Table 1 to Appendix I—Emission Standards for...-exceed emission standards specified in 40 CFR 94.8(e) apply for all engines subject to the Tier...

  12. 40 CFR Appendix I to Part 1042 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Tier 1 standards. NOX emissions from model year 2004 and later engines with displacement of 2.5 or more... CFR part 89 and summarized in the following table: Table 1 to Appendix I—Emission Standards for...-exceed emission standards specified in 40 CFR 94.8(e) apply for all engines subject to the Tier...

  13. 40 CFR Appendix A to Part 72 - Methodology for Annualization of Emissions Limits

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Methodology for Annualization of Emissions Limits A Appendix A to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. A Appendix A to Part 72—Methodology for Annualization of Emissions Limits For...

  14. 40 CFR Appendix B to Part 72 - Methodology for Conversion of Emissions Limits

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Methodology for Conversion of Emissions Limits B Appendix B to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. B Appendix B to Part 72—Methodology for Conversion of Emissions Limits For the purposes...

  15. 40 CFR Appendix D to Part 61 - Methods for Estimating Radionuclide Emissions

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Methods for Estimating Radionuclide Emissions D Appendix D to Part 61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS Pt. 61, App. D Appendix D to Part 61—Methods for...

  16. 40 CFR Appendix B to Part 72 - Methodology for Conversion of Emissions Limits

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Methodology for Conversion of Emissions Limits B Appendix B to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. B Appendix B to Part 72—Methodology for Conversion of Emissions Limits For the purposes...

  17. 40 CFR Appendix A to Part 72 - Methodology for Annualization of Emissions Limits

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Methodology for Annualization of Emissions Limits A Appendix A to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. A Appendix A to Part 72—Methodology for Annualization of Emissions Limits For...

  18. 40 CFR Appendix A to Part 72 - Methodology for Annualization of Emissions Limits

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Methodology for Annualization of Emissions Limits A Appendix A to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. A Appendix A to Part 72—Methodology for Annualization of Emissions Limits For...

  19. 40 CFR Appendix B to Part 72 - Methodology for Conversion of Emissions Limits

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Methodology for Conversion of Emissions Limits B Appendix B to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. B Appendix B to Part 72—Methodology for Conversion of Emissions Limits For the purposes...

  20. 40 CFR Appendix I to Part 94 - Emission-Related Engine Parameters and Specifications

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Emission-Related Engine Parameters and Specifications I Appendix I to Part 94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Pt. 94, App. I Appendix I to Part...

  1. 40 CFR Appendix S to Part 51 - Emission Offset Interpretative Ruling

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Emission Offset Interpretative Ruling S Appendix S to Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Pt. 51, App. S Appendix S to Part 51—Emission...

  2. 40 CFR Appendix S to Part 51 - Emission Offset Interpretative Ruling

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Emission Offset Interpretative Ruling S Appendix S to Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Pt. 51, App. S Appendix S to Part 51—Emission...

  3. 40 CFR Appendix S to Part 51 - Emission Offset Interpretative Ruling

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Emission Offset Interpretative Ruling S Appendix S to Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Pt. 51, App. S Appendix S to Part 51—Emission...

  4. 40 CFR Appendix A to Part 72 - Methodology for Annualization of Emissions Limits

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Methodology for Annualization of Emissions Limits A Appendix A to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. A Appendix A to Part 72—Methodology for Annualization of Emissions Limits For...

  5. 40 CFR Appendix I to Part 1068 - Emission-Related Components

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Emission-Related Components I Appendix I to Part 1068 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION..., emission-related components include any engine parts related to the following systems: 1....

  6. 40 CFR Appendix I to Part 1068 - Emission-Related Components

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Emission-Related Components I Appendix I to Part 1068 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION..., emission-related components include any engine parts related to the following systems: 1....

  7. 40 CFR Appendix D to Part 60 - Required Emission Inventory Information

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 7 2010-07-01 2010-07-01 true Required Emission Inventory Information D Appendix D to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Appendix D to Part 60—Required Emission Inventory Information (a) Completed NEDS point source form(s)...

  8. 40 CFR Appendix I to Part 1042 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR part 89 and summarized in the following table: Table 1 to Appendix I—Emission Standards for... standards for engines at or above 37 kW apply as specified in 40 CFR part 94 and summarized as follows: (1...-exceed emission standards specified in 40 CFR 94.8(e) apply for all engines subject to the Tier...

  9. Odor and odorous chemical emissions from animal buildings: Part 2. Odor emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was an add-on project to the National Air Emissions Monitoring Study (NAEMS) and focused on comprehensive measurement of odor emissions considering variations in seasons, animal types and olfactometry laboratories. Odor emissions from four of 14 NEAMS sites with nine barns/rooms (two dair...

  10. Odor and odorous chemical emissions from animal buildings: Part 3. Chemical emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to measure the long-term odor emissions and corresponding concentrations and emissions of 20 odorous volatile organic compounds (VOCs). This study was an add-on study to the National Air Emission Monitoring Study (NAEMS). Odor and odorous gas measurements at four NAEM...

  11. Odor and odorous chemical emissions from animal buildings: Part 3 - chemical emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was an add-on study to the National Air Emission Monitoring Study (NAEMS). The objective of this study was to measure odor emissions and corresponding concentrations and emissions of target odorous gases. Odor and odorous gas measurements at four NAEMS sites (dairy barns in Wisconsin-WI5B...

  12. Odor and odorous chemical emissions from animal buildings: Part 2 - odor emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was an add-on project to the National Air Emissions Monitoring Study (NAEMS) and focused on comprehensive measurement of odor emissions. Odor emissions from two animal species (dairy and swine) from four sites with nine barns/rooms (two dairy barns in Wisconsin, two dairy barns and two sw...

  13. Near-zero temperature coefficient of resistivity associated with magnetic ordering in antiperovskite Mn3+xNi1-xN

    NASA Astrophysics Data System (ADS)

    Deng, Sihao; Sun, Ying; Wang, Lei; Wu, Hui; Shi, Kewen; Hu, Pengwei; Huang, Qingzhen; Wang, Cong

    2016-01-01

    The near-zero temperature coefficient of resistivity (NZ-TCR) behavior is reported in the antiperovskite compounds Mn3+xNi1-xN (0 ≤ x ≤ 0.333). Our results indicate that the broad temperature range (above 275 K extending to above 220 K) of NZ-TCR is obtained by Mn doping at the Ni site. The short-range magnetic ordering is revealed by both neutron powder diffraction and inverse magnetic susceptibility. Further, we find a strong correlation between the anomalous resistivity change of Mn3+xNi1-xN from the metal-like to the NZ-TCR behavior and the lack of the long-range magnetic ordering. The possible mechanism of NZ-TCR behavior is discussed using the spin-disorder scattering model.

  14. Theory of wave propagation in magnetized near-zero-epsilon metamaterials: evidence for one-way photonic states and magnetically switched transparency and opacity.

    PubMed

    Davoyan, Arthur R; Engheta, Nader

    2013-12-20

    We study propagation of transverse-magnetic electromagnetic waves in the bulk and at the surface of a magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge; we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to the possibility for backscattering immune wave propagation and isolation. PMID:24483756

  15. Theory of Wave Propagation in Magnetized Near-Zero-Epsilon Metamaterials: Evidence for One-Way Photonic States and Magnetically Switched Transparency and Opacity

    NASA Astrophysics Data System (ADS)

    Davoyan, Arthur R.; Engheta, Nader

    2013-12-01

    We study propagation of transverse-magnetic electromagnetic waves in the bulk and at the surface of a magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge; we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to the possibility for backscattering immune wave propagation and isolation.

  16. Characterization of gaseous pollutant and particulate matter emission rates from a commercial broiler operation part I: Observed trends in emissions

    NASA Astrophysics Data System (ADS)

    Roumeliotis, Taylor S.; Dixon, Brad J.; Van Heyst, Bill J.

    2010-10-01

    This paper characterizes the emission rates of size fractionated particulate matter, inorganic aerosols, acid gases, ammonia and methane measured over four flocks at a commercial broiler chicken facility. Mean emission rates of each pollutant, along with sampling notes, were reported in this paper, the first in a series of two. Sampling notes were needed because inherent gaps in data may bias the mean emission rates. The mean emission rates of PM 10 and PM 2.5 were 5.0 and 0.78 g day -1 [Animal Unit, AU] -1, respectively, while inorganic aerosols mean emission rates ranged from 0.15 to 0.46 g day -1 AU -1 depending on the season. The average total acid gas emission rate was 0.43 g day -1 AU -1 with the greatest contribution from nitrous and nitric acids and little contribution from sulfuric acid (as SO 2). Ammonia emissions were seasonally dependent, with a mean emission rate of 66.0 g day -1 AU -1 in the cooler seasons and 94.5 g day -1 AU -1 during the warmer seasons. Methane emissions were relatively consistent with a mean emission rate of 208 g day -1 AU -1. The diurnal pattern in each pollutant's emission rate was relatively consistent after normalizing the hourly emissions according to each daily mean emission rate. Over the duration of a production cycle, all the measured pollutants' emissions increased proportionally to the total live mass of birds in the house, with the exception of ammonia. Interrelationships between pollutants provide evidence of mutually dependent release mechanisms, which suggests that it may be possible to fill data gaps with minimal data requirements. In the second paper (Roumeliotis, T.S., Dixon, B.J., Van Heyst, B.J. Characterization of gaseous pollutants and particulate matter emission rates from a commercial broiler operation part II: correlated emission rates. Atmospheric Environment, 2010.), regression correlations are developed to estimate daily mean emission rates for data gaps and, using the normalized hourly diurnal

  17. 40 CFR Appendix IV to Part 92 - Guidelines for Determining Equivalency Between Emission Measurement Systems

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... conducted in accordance with 40 CFR part 89 may also be used. (4) Equivalency of the systems should be... 8-mode nonroad engine tests, conducted in accordance with the provisions of 40 CFR part 89. (e... Between Emission Measurement Systems IV Appendix IV to Part 92 Protection of Environment...

  18. Patterns in Volatile Emission of Different Aerial Parts of Caper (Capparis spinosa L.).

    PubMed

    Ascrizzi, Roberta; Cioni, Pier Luigi; Giusti, Giulia; Pistelli, Luisa; Flamini, Guido

    2016-07-01

    We analyzed the spontaneous volatile emission of different aerial parts of the caper (Capparis spinosa L.) by HS-SPME-GC/MS. We identified 178 different compounds of which, in different proportions based on the sample type, the main ones were (E)-β-ocimene, methyl benzoate, linalool, β-caryophyllene, α-guaiene, germacrene D, bicyclogermacrene, germacrene B, (E)-nerolidol, isopropyl tetradecanoate, and hexahydrofarnesyl acetone. The multivariate statistical analyses seem to point out that the parameter leading the emission patterns is the function of the analyzed sample; the flower samples showed differences in the emission profile between their fertile and sterile portions and between the other parts of the plant. The green parts emission profiles group together in a cluster and are different from those of seeds and fruits. We also hydrodistilled fully bloomed caper flowers, whose volatile oil showed significant differences in the composition from those of other parts of the plant reported. PMID:27276076

  19. Ammonia emissions in Europe, part I: Development of a dynamical ammonia emission inventory

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Nitrogen input from agricultural ammonia emissions into the environment causes numerous environmental and health problems. The purpose of this study is to present and evaluate an improved ammonia emission inventory based on a dynamical temporal parameterization suitable to compare and assess ammonia abatement strategies. The setup of the dynamical time profile (DTP) consists of individual temporal profiles for ammonia emissions, calculated for each model grid cell, depending on temperature, crop type, fertilizer and manure application, as well as on local legislation. It is based on the method of Skjøth et al., 2004 and Gyldenkærne et al., 2005. The method has been modified to cover the study area and to improve the performance of the emission model. To compare the results of the dynamical approach with the results of the static time profile (STP) the ammonia emission parameterizations have been implemented in the SMOKE for Europe emission model. Furthermore, the influence on secondary aerosol formation in the North Sea region and possible changes triggered through the use of a modified temporal distribution of ammonia emissions were analysed with the CMAQ chemistry transport model. The results were evaluated with observations of the European Monitoring and Evaluation Programme (EMEP). The correlation coefficient of NH3 improved significantly for 12 out of 16 EMEP measurement stations and an improvement in predicting the Normalized Mean Error can be seen for particulate NH4+ and NO3-. The prediction of the 95th percentile of the daily average concentrations has improved for NH3, NH4+ and NO3-. The NH3 concentration modelled with the STP is 157% higher in winter, and about 22% lower in early summer than the one modelled with the new DTP. Consequently, the influence of the DTP on the formation of secondary aerosols is particularly noticeable in winter, when the PM2.5 concentration is 25% lower in comparison to the use of STP for temporal disaggregation. Besides

  20. Emissions from residential combustion considering end-uses and spatial constraints: Part II, emission reduction scenarios

    NASA Astrophysics Data System (ADS)

    Winijkul, Ekbordin; Bond, Tami C.

    2016-01-01

    Cooking, heating, and other activities in the residential sector are major sources of indoor and outdoor air pollution, especially when solid fuels are used to provide energy. Because of their deleterious effects on the atmosphere and human health, multinational strategies to reduce emissions have been proposed. This study examines the effects of some possible policies, considering realistic factors that constrain mitigation: end-uses, spatial constraints involving proximity to forest or electricity, existing technology, and assumptions about user behavior. Reduction scenarios are applied to a year-2010, spatially distributed baseline of emissions of particulate matter, black carbon, organic carbon, nitrogen oxides, methane, non-methane hydrocarbons, carbon monoxide, and carbon dioxide. Scenarios explored are: (1) cleanest current stove, where we assume that existing technology in each land type is applied to burn existing fuels; (2) stove standards, where we assume that stoves are designed to meet performance standards; and (3) clean fuels, where users adopt the cleanest fuels plausible in each land type. We assume that people living in forest access areas continue to use wood regardless of available fuels, so the clean-fuels scenario leads to a reduction in emissions of 18-25%, depending on the pollutant, across the study region. Cleaner stoves preferentially affect land types with forest access, where about half of the fuel is used; emission reductions range from 25 to 82%, depending on the pollutant. If stove performance standards can be met, particulate matter emissions are reduced by 62% for the loosest standards and 95% for the tightest standards, and carbon monoxide is reduced by 40% and 62% for the loosest and tightest standards. Reductions in specific regions and countries depend on the existing fuel mixture and the population division among land types, and are explored for Latin America, Africa, East Asia, South Asia, and Southeast Asia.

  1. 40 CFR Appendix P to Part 51 - Minimum Emission Monitoring Requirements

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Minimum Emission Monitoring Requirements P Appendix P to Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Pt. 51, App. P Appendix P to Part 51—Minimum...

  2. 40 CFR Appendix I to Part 92 - Emission Related Locomotive and Engine Parameters and Specifications

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Parameters and Specifications I Appendix I to Part 92 Protection of Environment ENVIRONMENTAL PROTECTION... ENGINES Pt. 92, App. I Appendix I to Part 92—Emission Related Locomotive and Engine Parameters and Specifications I. Basic Engine Parameters—Reciprocating Engines. 1. Compression ratio. 2. Type of air...

  3. 40 CFR Appendix IV to Part 92 - Guidelines for Determining Equivalency Between Emission Measurement Systems

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conducted in accordance with 40 CFR part 89 may also be used. (4) Equivalency of the systems should be... 8-mode nonroad engine tests, conducted in accordance with the provisions of 40 CFR part 89. (e... Emission Measurement Systems This appendix describes a series of correlation criteria that EPA considers...

  4. 40 CFR Appendix IV to Part 92 - Guidelines for Determining Equivalency Between Emission Measurement Systems

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... conducted in accordance with 40 CFR part 89 may also be used. (4) Equivalency of the systems should be... 8-mode nonroad engine tests, conducted in accordance with the provisions of 40 CFR part 89. (e... Emission Measurement Systems This appendix describes a series of correlation criteria that EPA considers...

  5. 40 CFR Appendix C to Part 72 - Actual 1985 Yearly SO2 Emissions Calculation

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Actual 1985 Yearly SO2 Emissions Calculation C Appendix C to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. C Appendix C to Part 72—Actual 1985 Yearly...

  6. 40 CFR Appendix C to Part 72 - Actual 1985 Yearly SO2 Emissions Calculation

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Actual 1985 Yearly SO2 Emissions Calculation C Appendix C to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. C Appendix C to Part 72—Actual 1985 Yearly...

  7. 40 CFR Appendix D to Part 60 - Required Emission Inventory Information

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... D Appendix D to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED) Pt. 60, App. D Appendix D to Part 60—Required Emission Inventory Information (a) Completed NEDS point source form(s)...

  8. 40 CFR Appendix D to Part 60 - Required Emission Inventory Information

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... D Appendix D to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED) Pt. 60, App. D Appendix D to Part 60—Required Emission Inventory Information (a) Completed NEDS point source form(s)...

  9. 40 CFR Appendix D to Part 60 - Required Emission Inventory Information

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... D Appendix D to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED) Pt. 60, App. D Appendix D to Part 60—Required Emission Inventory Information (a) Completed NEDS point source form(s)...

  10. 40 CFR Appendix I to Part 1042 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CFR part 89 and summarized in the following table: Table 1 to Appendix I—Emission Standards for... standards for engines at or above 37 kW apply as specified in 40 CFR part 94 and summarized as follows: (1... standards specified in 40 CFR 94.8(e) apply for all engines subject to the Tier 2 standards described...

  11. Near-zero thermal expansion of In2(1‑x)(HfMg) x Mo3O12 with tailored phase transition

    NASA Astrophysics Data System (ADS)

    Cheng, Yong-Guang; Mao, Yan-Chao; Liu, Xain-Sheng; Yuan, Bao-He; Chao, Ming-Ju; Liang, Er-Jun

    2016-08-01

    Solid solutions of In2(1‑x)(HfMg) x Mo3O12 are synthesized by solid state reaction with the aim to reduce the phase transition temperature of In2Mo3O12 and improve its thermal expansion property. The effects of (HfMg)6+ incorporation on the phase transition and thermal expansion are investigated. It is shown that the monoclinic-to-orthorhombic phase transition temperature obviously decreases and the coefficient of thermal expansion (CTE) of the orthorhombic becomes less negative and approaches to zero with increasing the content of (HfMg)6+. A near zero thermal expansion covering the case at room temperature (RT) is achieved for the solid solutions with x ≥ 0.85, implying potential applications of this material in many fields. Project supported by the National Natural Science Foundation of China (Grant Nos. 11574276, 51302249, and 51503185) and the Doctoral Fund of the Ministry of Education of China (Grant No. 20114101110003).

  12. General Strategy for Broadband Coherent Perfect Absorption and Multi-wavelength All-optical Switching Based on Epsilon-Near-Zero Multilayer Films

    PubMed Central

    Kim, Tae Young; Badsha, Md. Alamgir; Yoon, Junho; Lee, Seon Young; Jun, Young Chul; Hwangbo, Chang Kwon

    2016-01-01

    We propose a general, easy-to-implement scheme for broadband coherent perfect absorption (CPA) using epsilon-near-zero (ENZ) multilayer films. Specifically, we employ indium tin oxide (ITO) as a tunable ENZ material, and theoretically investigate CPA in the near-infrared region. We first derive general CPA conditions using the scattering matrix and the admittance matching methods. Then, by combining these two methods, we extract analytic expressions for all relevant parameters for CPA. Based on this theoretical framework, we proceed to study ENZ CPA in a single layer ITO film and apply it to all-optical switching. Finally, using an ITO multilayer of different ENZ wavelengths, we implement broadband ENZ CPA structures and investigate multi-wavelength all-optical switching in the technologically important telecommunication window. In our design, the admittance matching diagram was employed to graphically extract not only the structural parameters (the film thicknesses and incident angles), but also the input beam parameters (the irradiance ratio and phase difference between two input beams). We find that the multi-wavelength all-optical switching in our broadband ENZ CPA system can be fully controlled by the phase difference between two input beams. The simple but general design principles and analyses in this work can be widely used in various thin-film devices. PMID:26965195

  13. General Strategy for Broadband Coherent Perfect Absorption and Multi-wavelength All-optical Switching Based on Epsilon-Near-Zero Multilayer Films.

    PubMed

    Kim, Tae Young; Badsha, Md Alamgir; Yoon, Junho; Lee, Seon Young; Jun, Young Chul; Hwangbo, Chang Kwon

    2016-01-01

    We propose a general, easy-to-implement scheme for broadband coherent perfect absorption (CPA) using epsilon-near-zero (ENZ) multilayer films. Specifically, we employ indium tin oxide (ITO) as a tunable ENZ material, and theoretically investigate CPA in the near-infrared region. We first derive general CPA conditions using the scattering matrix and the admittance matching methods. Then, by combining these two methods, we extract analytic expressions for all relevant parameters for CPA. Based on this theoretical framework, we proceed to study ENZ CPA in a single layer ITO film and apply it to all-optical switching. Finally, using an ITO multilayer of different ENZ wavelengths, we implement broadband ENZ CPA structures and investigate multi-wavelength all-optical switching in the technologically important telecommunication window. In our design, the admittance matching diagram was employed to graphically extract not only the structural parameters (the film thicknesses and incident angles), but also the input beam parameters (the irradiance ratio and phase difference between two input beams). We find that the multi-wavelength all-optical switching in our broadband ENZ CPA system can be fully controlled by the phase difference between two input beams. The simple but general design principles and analyses in this work can be widely used in various thin-film devices. PMID:26965195

  14. General Strategy for Broadband Coherent Perfect Absorption and Multi-wavelength All-optical Switching Based on Epsilon-Near-Zero Multilayer Films

    NASA Astrophysics Data System (ADS)

    Kim, Tae Young; Badsha, Md. Alamgir; Yoon, Junho; Lee, Seon Young; Jun, Young Chul; Hwangbo, Chang Kwon

    2016-03-01

    We propose a general, easy-to-implement scheme for broadband coherent perfect absorption (CPA) using epsilon-near-zero (ENZ) multilayer films. Specifically, we employ indium tin oxide (ITO) as a tunable ENZ material, and theoretically investigate CPA in the near-infrared region. We first derive general CPA conditions using the scattering matrix and the admittance matching methods. Then, by combining these two methods, we extract analytic expressions for all relevant parameters for CPA. Based on this theoretical framework, we proceed to study ENZ CPA in a single layer ITO film and apply it to all-optical switching. Finally, using an ITO multilayer of different ENZ wavelengths, we implement broadband ENZ CPA structures and investigate multi-wavelength all-optical switching in the technologically important telecommunication window. In our design, the admittance matching diagram was employed to graphically extract not only the structural parameters (the film thicknesses and incident angles), but also the input beam parameters (the irradiance ratio and phase difference between two input beams). We find that the multi-wavelength all-optical switching in our broadband ENZ CPA system can be fully controlled by the phase difference between two input beams. The simple but general design principles and analyses in this work can be widely used in various thin-film devices.

  15. Cryptochromes and Hormone Signal Transduction under Near-Zero Magnetic Fields: New Clues to Magnetic Field Effects in a Rice Planthopper

    PubMed Central

    Wan, Gui-Jun; Wang, Wen-Jing; Xu, Jing-Jing; Yang, Quan-Feng; Dai, Ming-Jiang; Zhang, Feng-Jiao; Sword, Gregory A.; Pan, Wei-Dong; Chen, Fa-Jun

    2015-01-01

    Although there are considerable reports of magnetic field effects (MFE) on organisms, very little is known so far about the MFE-related signal transduction pathways. Here we establish a manipulative near-zero magnetic field (NZMF) to investigate the potential signal transduction pathways involved in MFE. We show that exposure of migratory white-backed planthopper, Sogatella furcifera, to the NZMF results in delayed egg and nymphal development, increased frequency of brachypterous females, and reduced longevity of macropterous female adults. To understand the changes in gene expression underlying these phenotypes, we examined the temporal patterns of gene expression of (i) CRY1 and CRY2 as putative magnetosensors, (ii) JHAMT, FAMeT and JHEH in the juvenile hormone pathway, (iii) CYP307A1 in the ecdysone pathway, and (iv) reproduction-related Vitellogenin (Vg). The significantly altered gene expression of CRY1 and CRY2 under the NZMF suggest their developmental stage-specific patterns and potential upstream location in magnetic response. Gene expression patterns of JHAMT, JHEH and CYP307A1 were consistent with the NZMF-triggered delay in nymphal development, higher proportion of brachypterous female adults, and the shortened longevity of macropterous female adults, which show feasible links between hormone signal transduction and phenotypic MFE. By conducting manipulative NZMF experiments, our study suggests an important role of the geomagnetic field (GMF) in modulating development and physiology of insects, provides new insights into the complexity of MFE-magnetosensitivity interactions, and represents an initial but crucial step forward in understanding the molecular basis of cryptochromes and hormone signal transduction involved in MFE. PMID:26173003

  16. Cryptochromes and Hormone Signal Transduction under Near-Zero Magnetic Fields: New Clues to Magnetic Field Effects in a Rice Planthopper.

    PubMed

    Wan, Gui-Jun; Wang, Wen-Jing; Xu, Jing-Jing; Yang, Quan-Feng; Dai, Ming-Jiang; Zhang, Feng-Jiao; Sword, Gregory A; Pan, Wei-Dong; Chen, Fa-Jun

    2015-01-01

    Although there are considerable reports of magnetic field effects (MFE) on organisms, very little is known so far about the MFE-related signal transduction pathways. Here we establish a manipulative near-zero magnetic field (NZMF) to investigate the potential signal transduction pathways involved in MFE. We show that exposure of migratory white-backed planthopper, Sogatella furcifera, to the NZMF results in delayed egg and nymphal development, increased frequency of brachypterous females, and reduced longevity of macropterous female adults. To understand the changes in gene expression underlying these phenotypes, we examined the temporal patterns of gene expression of (i) CRY1 and CRY2 as putative magnetosensors, (ii) JHAMT, FAMeT and JHEH in the juvenile hormone pathway, (iii) CYP307A1 in the ecdysone pathway, and (iv) reproduction-related Vitellogenin (Vg). The significantly altered gene expression of CRY1 and CRY2 under the NZMF suggest their developmental stage-specific patterns and potential upstream location in magnetic response. Gene expression patterns of JHAMT, JHEH and CYP307A1 were consistent with the NZMF-triggered delay in nymphal development, higher proportion of brachypterous female adults, and the shortened longevity of macropterous female adults, which show feasible links between hormone signal transduction and phenotypic MFE. By conducting manipulative NZMF experiments, our study suggests an important role of the geomagnetic field (GMF) in modulating development and physiology of insects, provides new insights into the complexity of MFE-magnetosensitivity interactions, and represents an initial but crucial step forward in understanding the molecular basis of cryptochromes and hormone signal transduction involved in MFE. PMID:26173003

  17. The impact of shipping emissions on air pollution in the greater North Sea region - Part 1: Current emissions and concentrations

    NASA Astrophysics Data System (ADS)

    Aulinger, A.; Matthias, V.; Zeretzke, M.; Bieser, J.; Quante, M.; Backes, A.

    2016-01-01

    The North Sea is one of the areas with the highest ship traffic densities worldwide. At any time, about 3000 ships are sailing its waterways. Previous scientific publications have shown that ships contribute significantly to atmospheric concentrations of NOx, particulate matter and ozone. Especially in the case of particulate matter and ozone, this influence can even be seen in regions far away from the main shipping routes. In order to quantify the effects of North Sea shipping on air quality in its bordering states, it is essential to determine the emissions from shipping as accurately as possible. Within Interreg IVb project Clean North Sea Shipping (CNSS), a bottom-up approach was developed and used to thoroughly compile such an emission inventory for 2011 that served as the base year for the current emission situation. The innovative aspect of this approach was to use load-dependent functions to calculate emissions from the ships' current activities instead of averaged emission factors for the entire range of the engine loads. These functions were applied to ship activities that were derived from hourly records of Automatic Identification System signals together with a database containing the engine characteristics of the vessels that traveled the North Sea in 2011. The emission model yielded ship emissions among others of NOx and SO2 at high temporal and spatial resolution that were subsequently used in a chemistry transport model in order to simulate the impact of the emissions on pollutant concentration levels. The total emissions of nitrogen reached 540 Gg and those of sulfur oxides 123 Gg within the North Sea - including the adjacent western part of the Baltic Sea until 5° W. This was about twice as much of those of a medium-sized industrialized European state like the Netherlands. The relative contribution of ships to, for example, NO2 concentration levels ashore close to the sea can reach up to 25 % in summer and 15 % in winter. Some hundred kilometers

  18. Air quality and public health impacts of UK airports. Part I: Emissions

    NASA Astrophysics Data System (ADS)

    Stettler, M. E. J.; Eastham, S.; Barrett, S. R. H.

    2011-10-01

    The potential adverse human health and climate impacts of emissions from UK airports have become a significant political issue, yet the emissions, air quality impacts and health impacts attributable to UK airports remain largely unstudied. We produce an inventory of UK airport emissions - including aircraft landing and takeoff (LTO) operations and airside support equipment - with uncertainties quantified. The airports studied account for more than 95% of UK air passengers in 2005. We estimate that in 2005, UK airports emitted 10.2 Gg [-23 to +29%] of NO x, 0.73 Gg [-29 to +32%] of SO 2, 11.7 Gg [-42 to +77%] of CO, 1.8 Gg [-59 to +155%] of HC, 2.4 Tg [-13 to +12%] of CO 2, and 0.31 Gg [-36 to +45%] of PM 2.5. This translates to 2.5 Tg [-12 to +12%] CO 2-eq using Global Warming Potentials for a 100-year time horizon. Uncertainty estimates were based on analysis of data from aircraft emissions measurement campaigns and analyses of aircraft operations. The First-Order Approximation (FOA3) - currently the standard approach used to estimate particulate matter emissions from aircraft - is compared to measurements and it is shown that there are discrepancies greater than an order of magnitude for 40% of cases for both organic carbon and black carbon emissions indices. Modified methods to approximate organic carbon emissions, arising from incomplete combustion and lubrication oil, and black carbon are proposed. These alterations lead to factor 8 and a 44% increase in the annual emissions estimates of black and organic carbon particulate matter, respectively, leading to a factor 3.4 increase in total PM 2.5 emissions compared to the current FOA3 methodology. Our estimates of emissions are used in Part II to quantify the air quality and health impacts of UK airports, to assess mitigation options, and to estimate the impacts of a potential London airport expansion.

  19. 40 CFR Appendix I to Part 92 - Emission Related Locomotive and Engine Parameters and Specifications

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Emission Related Locomotive and Engine Parameters and Specifications I Appendix I to Part 92 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Pt. 92, App. I Appendix I to...

  20. 40 CFR Appendix P to Part 51 - Minimum Emission Monitoring Requirements

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... must include in order to be approved under the provisions of 40 CFR 51.165(b). These requirements... is: 1.2.1 Subject to a new source performance standard promulgated in 40 CFR part 60 pursuant to... in paragraph 2.1 of this appendix, shall be monitored for opacity, nitrogen oxides emissions,...

  1. 40 CFR Appendix I to Part 92 - Emission Related Locomotive and Engine Parameters and Specifications

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Emission Related Locomotive and Engine Parameters and Specifications I Appendix I to Part 92 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Pt. 92, App. I Appendix I to...

  2. 40 CFR 1060.101 - What evaporative emission requirements apply under this part?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... (c) Section 1060.104 describes running loss emission control requirements for fuel systems. (d... systems so they cause or contribute to an unreasonable risk to public health, welfare, or safety while... this part. The following particular requirements apply to equipment that is subject to running loss...

  3. 40 CFR Appendix I to Part 92 - Emission Related Locomotive and Engine Parameters and Specifications

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Catalytic converter system. a. Active surface area. b. Volume of catalyst. c. Conversion efficiency. 4... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Emission Related Locomotive and Engine Parameters and Specifications I Appendix I to Part 92 Protection of Environment ENVIRONMENTAL...

  4. Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes - Update to Include Evaluation of Impact of Including a Humidifier Option

    SciTech Connect

    Baxter, Van D

    2007-02-01

    The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further development. Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft{sup 2} houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, HVAC Equipment Design options for Near-Zero-Energy Homes

  5. Emissions from international shipping in the Belgian part of the North Sea and the Belgian seaports

    NASA Astrophysics Data System (ADS)

    De Meyer, Pieter; Maes, Frank; Volckaert, Annemie

    The objective of this study is to estimate the atmospheric emissions by international merchant shipping of carbon dioxide (CO 2), sulphur dioxide (SO 2) and nitrogen oxides (NO X) during 1 year in the Belgian part of the North Sea, including the four Belgian seaports: Antwerp, Ghent, Ostend and Zeebrugge. The estimated emissions are based on a bottom-up, activity-based methodology (Group 1), covering more than 90% of shipping activity, complemented with a top-down fuel consumption methodology for the remaining activities. In total, an estimate of 1880 kton CO 2, 31 kton SO 2 and 39 kton NO X is emitted over the period April 2003 until March 2004. Compared to national inventories (2003 data) this accounts to 1.5% for CO 2, 30% for SO 2 and 22% for NO X of total emissions of these gases in Belgium. When the CO 2 figure is compared with the current estimate of CO 2 emissions from international shipping, based on sold bunker fuels (22 754 kton CO 2), the relevance of a detailed and precise emission inventory becomes clear. In the end, the Belgian estimates are validated by comparing them with Dutch, EU and international emission estimates.

  6. Dayglow Emission Line Profiles from the Outer Planets Cycle 4-MED Part 2 OF 5414

    NASA Astrophysics Data System (ADS)

    Clarke, John

    1994-01-01

    Recent IUE observations of the H Ly alpha emission line profilefrom Jupiter's dayglow and aurora reveal a substantial line broadening,implying that the observed high brightness is due to resonantscattering of solar emission with a broad line rather than chargedparticle excitation. This may reflect highly energetic processesproducing a 5-10 km/sec suprathermal population of H atoms in Jupiter'supper atmosphere, which in turn may be related to the unresolved questionof the high exospheric temperatures of 400-1200 K detected on all 4 giantplanets during the Voyager encounters. It is clear that if the bright HLy alpha emissions from the outer planets are due mainly to resonantscattering of solar and interplanetary emissions, as observedon Jupiter and Saturn from long term correlations with the solarLy alpha flux, then the lines from all 4 planets must be broad toexplain the observed high albedos. The H Ly alpha lineshapes providea discriminant between the processes of resonant scattering andcharged particle excitation. We propose to obtain high signal to noiseH Ly alpha line profile measurements from Saturn, Uranus, and Neptuneto resolve the questions about the excitation processes for the brightairglow emissions.SATURN PART ONLY - NEPTUNE AND URANUS IN ORIGIAL PROP (5414).

  7. 40 CFR Table W - 2 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false 2 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas Processing W Table W Protection of... of Part 98—Default Total Hydrocarbon Emission Factors for Onshore Natural Gas Processing...

  8. 40 CFR Table W - 4 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Underground Natural Gas...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false 4 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Underground Natural Gas Storage W Table W Protection of... of Part 98—Default Total Hydrocarbon Emission Factors for Underground Natural Gas Storage...

  9. 40 CFR Table W - 2 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false 2 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas Processing W Table W Protection of... of Part 98—Default Total Hydrocarbon Emission Factors for Onshore Natural Gas Processing...

  10. 40 CFR Table W - 4 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Underground Natural Gas...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false 4 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Underground Natural Gas Storage W Table W Protection of... of Part 98—Default Total Hydrocarbon Emission Factors for Underground Natural Gas Storage...

  11. 40 CFR Table W - 3 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false 3 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas Transmission Compression W Table W Protection...-3 of Subpart W of Part 98—Default Total Hydrocarbon Emission Factors for Onshore Natural...

  12. 40 CFR Table W - 3 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false 3 of Subpart W of Part 98-Default Total Hydrocarbon Emission Factors for Onshore Natural Gas Transmission Compression W Table W Protection...-3 of Subpart W of Part 98—Default Total Hydrocarbon Emission Factors for Onshore Natural...

  13. 40 CFR Appendix D to Part 52 - Determination of Sulfur Dioxide Emissions From Stationary Sources by Continuous Monitors

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Emissions From Stationary Sources by Continuous Monitors D Appendix D to Part 52 Protection of Environment... PLANS (CONTINUED) Pt. 52, App. D Appendix D to Part 52—Determination of Sulfur Dioxide Emissions From... sulfur dioxide by the Reference method and record the results on the example sheet shown in Figure...

  14. Observations of volatile organic compounds during ARCTAS - Part 1: Biomass burning emissions and plume enhancements

    NASA Astrophysics Data System (ADS)

    Hornbrook, R. S.; Blake, D. R.; Diskin, G. S.; Fuelberg, H. E.; Meinardi, S.; Mikoviny, T.; Sachse, G. W.; Vay, S. A.; Weinheimer, A. J.; Wiedinmyer, C.; Wisthaler, A.; Hills, A.; Riemer, D. D.; Apel, E. C.

    2011-05-01

    Mixing ratios of a large number of volatile organic compounds (VOCs) were observed by the Trace Organic Gas Analyzer (TOGA) on board the NASA DC-8 as part of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign. Many of these VOCs were observed concurrently by one or both of two other VOC measurement techniques on board the DC-8: proton-transfer-reaction mass spectrometry (PTR-MS) and whole air canister sampling (WAS). A comparison of these measurements to the data from TOGA indicates good agreement for the majority of co-measured VOCs. The ARCTAS study, which included both spring and summer deployments, provided opportunities to sample a large number of biomass burning (BB) plumes with origins in Asia, California and Central Canada, ranging from very recent emissions to plumes aged one week or more. For this analysis, identified BB plumes were grouped by flight, source region and, in some cases, time of day, generating 40 individual plume groups, each consisting of one or more BB plume interceptions. Normalized excess mixing ratios (EMRs) to CO were determined for each of the 40 plume groups for up to 19 different VOCs or VOC groups, many of which show significant variability, even within relatively fresh plumes. This variability demonstrates the importance of assessing BB plumes both regionally and temporally, as emissions can vary from region to region, and even within a fire over time. Comparisons with literature confirm that variability of EMRs to CO over an order of magnitude for many VOCs is consistent with previous observations. However, this variability is often diluted in the literature when individual observations are averaged to generate an overall regional EMR from a particular study. Previous studies give the impression that emission ratios are generally consistent within a given region, and this is not necessarily the case, as our results show. For some VOCs, earlier assumptions may lead to

  15. Alternative strategies for energy recovery from municipal solid waste Part B: Emission and cost estimates.

    PubMed

    Consonni, S; Giugliano, M; Grosso, M

    2005-01-01

    This two-part paper assesses four strategies for energy recovery from Municipal Solid Waste (MSW) by dedicated Waste-To-Energy (WTE) plants. In strategy 1, the residue of Material Recovery (MR) is fed directly to a grate combustor, while in strategy 2 the grate combustor comes downstream of light mechanical treatment. In strategies 3 and 4, the MR residue is converted into Refuse Derived Fuel (RDF), in a fluidized cumbuster bed. The results of Part A, devoted to mass and energy balances, clearly show that pre-treating the MR residue in order to increase the heating value of the feedstock fed to the WTE plant has marginal effects on the energy efficiency of the WTE plant. When considering the efficiency of the whole strategy of waste management, the energy balances show that the more thorough the pre-treatment, the smaller the amount of energy recovered per unit of MR residue. Starting from the heat/mass balances illustrated in Part A, Part B examines the environmental impacts and economics of the various strategies by means of a Life Cycle Assessment (LCA). Results show that treating the MR residues ahead of the WTE plant does not provide environmental or economic benefits. RDF production worsens almost all impact indicators because it reduces net electricity production and thus the displacement of power plant emissions; it also increases costs, because the benefits of improving the quality of the material fed to the WTE plant do not compensate the cost of such improvement. PMID:15737711

  16. Characterization of gaseous pollutant and particulate matter emission rates from a commercial broiler operation part II: Correlated emission rates

    NASA Astrophysics Data System (ADS)

    Roumeliotis, Taylor S.; Dixon, Brad J.; Van Heyst, Bill J.

    2010-10-01

    Emission rates of ammonia, acid gases, inorganic aerosols, methane, and size fractionated particulate matter were measured from a commercial broiler facility. This paper discusses the statistically influential parameters on numerous pollutants' emission from a broiler chicken facility and generates emission correlations to fill data gaps and develop averaged emission factors. Live mass of the birds was commonly a significant variable to each pollutant's emission. Some variables significantly impacted the pollutants' emissions, such as litter moisture content, but were measured discretely and cannot be used for filling in data gaps. House parameter correlations were, therefore, developed using parameters measured at the facility, such as indoor temperature, relative humidity, and the live mass of the birds, and relied on the mutual behaviour of discretely measured explanatory parameters and continuously monitored confounding variables. The live mass and the difference in the indoor temperature and the house set-point temperature were the most significant variables in each pollutant's correlation. The correlations predicted each pollutants emission to within 20% (total mass basis) over most broiler production cycles. Their validation on independent datasets also successfully estimated the flocks' emissions to within 3%. Emission factors (EFs) were developed for methane, ammonia, and size fractionated particulate matter using measured data and correlated emissions to fill in data gaps. PM 10 (particulate matter ≤10 microns) EFs were estimated to be 4.6 and 5.9 g d -1 [Animal Unit, AU] -1 for five and six week production cycles, respectively. PM 2.5 (PM ≤ 2.5 microns) EFs were 0.8 and 1.4 g d -1 AU -1 for five and six week cycles, respectively. Ammonia and methane emission factors were estimated at 120.8 and 197.0 g d -1 AU -1, respectively for a five week production cycle.

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

    PubMed

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

    2012-10-01

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

  18. Characterization of Delayed-Particle Emission Signatures for Pyroprocessing. Part 1: ABTR Fuel Assembly.

    SciTech Connect

    Durkee, Jr., Joe W.

    2015-06-19

    A three-part study is conducted using the MCNP6 Monte Carlo radiation-transport code to calculate delayed-neutron (DN) and delayed-gamma (DG) emission signatures for nondestructive assay (NDA) metal-fuel pyroprocessing. In Part 1, MCNP6 is used to produce irradiation-induced used nuclear fuel (UNF) isotopic inventories for an Argonne National Laboratory (ANL) Advanced Burner Test Reactor (ABTR) preconceptual design fuel assembly (FA) model. The initial fuel inventory consists of uranium mixed with light-water-reactor transuranic (TRU) waste and 10 wt% zirconium (U-LWR-SFTRU-10%Zr). To facilitate understanding, parametric evaluation is done using models for 3% and 5% initial 235U a% enrichments, burnups of 5, 10, 15, 20, 30, …, 120 GWd/MTIHM, and 3-, 5-, 10-, 20-, and 30- year cooling times. Detailed delayed-particle radioisotope source terms for the irradiate FA are created using BAMF-DRT and SOURCES3A. Using simulation tallies, DG activity ratios (DGARs) are developed for 134Cs/137Cs 134Cs/154Eu, and 154Eu/137Cs markers as a function of (1) burnup and (2) actinide mass, including elemental uranium, neptunium, plutonium, americium, and curium. Spectral-integrated DN emission is also tallied. The study reveals a rich assortment of DGAR behavior as a function of DGAR type, enrichment, burnup, and cooling time. Similarly, DN emission plots show variation as a function of burnup and of actinide mass. Sensitivity of DGAR and DN signatures to initial 235U enrichment, burnup, and cooling time is evident. Comparisons of the ABTR radiation signatures and radiation signatures previously reported for a generic Westinghouse oxide-fuel assembly indicate that there are pronounced differences in the ABTR and Westinghouse oxide-fuel DN and DG signatures. These differences are largely attributable to the initial TRU inventory in the ABTR fuel. The actinide and nonactinide inventories for the

  19. Biodiesel emissions profile in modern diesel vehicles. Part 1: Effect of biodiesel origin on the criteria emissions.

    PubMed

    Bakeas, Evangelos; Karavalakis, Georgios; Stournas, Stamoulis

    2011-04-01

    This paper presents the regulated emissions profile of a Euro 4 compliant common rail passenger car, fuelled with low concentration biodiesel blends. Four biodiesels of different origin and quality blended with a typical automotive diesel fuel at proportions of 10, 20, and 30% v/v. Emission and fuel consumption measurements were conducted on a chassis dynamometer with constant volume sampling (CVS) technique, over the New European Driving Cycle (NEDC) and the real traffic-based Artemis driving cycles. Limited effects were observed on CO(2) emissions, while fuel consumption marginally increased with biodiesel. PM, HC and CO emissions improved with the addition of biodiesel, with some exceptions. Some increases with biodiesel were observed over the NEDC, as a consequence of biodiesel characteristics and engine conditions. NO(x) emissions were increased with the use of biodiesel blends and positively correlated with fuel unsaturation levels. PMID:21316737

  20. Imaging of SO2 emissions from anthropogenic sources as part of AROMAT campaign

    NASA Astrophysics Data System (ADS)

    Brenot, H. H.; Merlaud, A.; Meier, A.; Ruhtz, T.; Van Roozendael, M.; Stebel, K.; Constantin, D.; Belegante, L.; Dekemper, E.; Theys, N.; Campion, R.; Schuettemeyer, D.

    2015-12-01

    This study presents field campaign measurements of SO2 emissions from pollution source in Romania. Three types of instruments (SO2 camera, whisk and push broom imager) proceeded ground-based and airborne data acquisition as part of the AROMAT ESA project (monitoring of SO2 plume from a large thermoelectric plant). The SO2 camera used is an imaging system composed of two UV cameras (synchronised in space and time) allowing fast acquisitions of intensity. Each camera is equipped with the same lens and a specific narrow band-pass filter (one at the wavelength at which SO2 absorbs and one at an off-band wavelength). The combination of two UV cameras provides a 2D image of the integrated content of SO2. The Small Whisk broom Imager for trace gases monitoriNG (SWING) used in this study and developed at the Belgian Institute for Space Aeronomy (BIRA), is based on a compact ultra-violet visible spectrometer and a scanning mirror. The Airborne imaging instrument for Measurements of Atmospheric Pollution (AirMAP) constructed at the Institute of Environmental Physics of the University of Bremen (IUP), performed SO2 measurements in the UV-visible spectral range. Both whisk and push broom scanner use the DOAS technique, that is based on the relationship between the quantity of light absorbed and the number of SO2 molecules in the light path. SWING and AirMAP instruments provide scans of SO2 column density. Quantification of 2D field contents and fluxes of anthropogenic SO2 emissions from Turceni power station (Romania) are shown. Preparatory results from data acquisition in the harbour of Antwerp (monitoring of SO2 emissions from refinery and chemical industry) are also presented.

  1. A vehicle emissions system using a car simulator and a geographical information system: Part 1--System description and testing.

    PubMed

    Jazcilevich, Arón D; García-Fragoso, Alejandro; García Reynoso, Agustín; Grutter, Michel; Diego-Ayala, Ulises; Lents, Jim; Davis, Nicole

    2007-10-01

    A methodology for estimating vehicular emissions comprising a car simulator, a basic traffic model, and a geographical information system is capable of estimating vehicle emissions with high time and space resolution. Because of the extent of the work conducted, this article comprises two sections: In Part 1 of this work, we describe the system and its components and use examples for testing it. In Part 2 we will study in more detail the emissions of the sample fleet using the system and will make comparisons with another emission model. The experimental data for the car simulator is obtained using on-board measuring equipment and laboratory Fourier transform IR (FTIR) measurements with a dynamometer following typical driving cycles. The car simulator uses this data to generate emission factors every second. These emission factors, together with information on car activity and velocity profiles of highways and residential and arterial roads in Mexico City in conjunction with a basic traffic model, provide emissions per second of a sample fleet. A geographical information system is used to localize these road emissions. PMID:17972768

  2. The impact of shipping emissions on air pollution in the Greater North Sea region - Part 1: Current emissions and concentrations

    NASA Astrophysics Data System (ADS)

    Aulinger, A.; Matthias, V.; Zeretzke, M.; Bieser, J.; Quante, M.; Backes, A.

    2015-04-01

    The North Sea is one of the areas with the highest ship traffic densities worldwide. At any time, about 3000 ships are sailing its waterways. Previous scientific publications have shown that ships contribute significantly to atmospheric concentrations of NOx, particulate matter and ozone. Especially in the case of particulate matter and ozone this influence can even be seen in regions far away from the main shipping routes. In order to quantify the effects of North Sea shipping on air quality in its bordering states, it is essential to determine the emissions from shipping as accurately as possible. Within the Interreg IVb project Clean North Sea Shipping (CNSS) a bottom-up approach was developed and used to thoroughly compile such an emission inventory for 2011 that served as the base year for the current emission situation. The innovative aspect of this approach was to use load dependent functions to calculate emissions from the ships' current activities instead of averaged emission factors for the entire range of the engine loads. These functions were applied to ship activities that were derived from hourly records of Automatic Identification System signals together with a data base containing the engine characteristics of the vessels that traveled the North Sea in 2011. The emission model yielded ship emissions among others of NOx and SO2 in high temporal and spatial resolution that were subsequently used in a chemistry transport model in order to simulate the impact of the emissions on pollutant concentration levels. The total emissions of nitrogen reached 540 Gg and of sulfur oxides 123 Gg within the North Sea, which was about twice as much of those of a medium-sized industrialized European state like the Netherlands. The relative contribution of ships to, for example, NO2 concentration levels ashore close to the sea can reach up to 25% in summer and 15% in winter. Some hundred kilometers away from the sea the contribution was about 6% in summer and 4% in

  3. Gunshot residue testing in suicides: Part II: Analysis by inductive coupled plasma-atomic emission spectrometry.

    PubMed

    Molina, D Kimberley; Castorena, Joe L; Martinez, Michael; Garcia, James; DiMaio, Vincent J M

    2007-09-01

    Several different methods can be employed to test for gunshot residue (GSR) on a decedent's hands, including scanning electron microscopy with energy dispersive x-ray (SEM/EDX) and inductive coupled plasma-atomic emission spectrometry (ICP-AES). In part I of this 2-part series, GSR results performed by SEM/EDX in undisputed cases of suicidal handgun wounds were studied. In part II, the same population was studied, deceased persons with undisputed suicidal handgun wounds, but GSR testing was performed using ICP-AES. A total of 102 cases were studied and analyzed for caliber of weapon, proximity of wound, and the results of the GSR testing. This study found that 50% of cases where the deceased was known to have fired a handgun immediately prior to death had positive GSR results by ICP/AES, which did not differ from the results of GSR testing by SEM/EDX. Since only 50% of cases where the person is known to have fired a weapon were positive for GSR by either method, this test should not be relied upon to determine whether someone has discharged a firearm and is not useful as a determining factor of whether or not a wound is self-inflicted or non-self-inflicted. While a positive GSR result may be of use, a negative result is not helpful in the medical examiner setting as a negative result indicates that either a person fired a weapon prior to death or a person did not fire a weapon prior to death. PMID:17721164

  4. Work function measurements by the field emission retarding potential method

    NASA Technical Reports Server (NTRS)

    Swanson, L. W.; Strayer, R. W.; Mackie, W. A.

    1971-01-01

    Using the field emission retarding potential method true work functions have been measured for the following monocrystalline substrates: W(110), W(111), W(100), Nb(100), Ni(100), Cu(100), Ir(110) and Ir(111). The electron elastic and inelastic reflection coefficients from several of these surfaces have also been examined near zero primary beam energy.

  5. Environmental assessment of three egg production systems - Part III: Airborne bacteria concentrations and emissions.

    PubMed

    Zhao, Y; Zhao, D; Ma, H; Liu, K; Atilgan, A; Xin, H

    2016-07-01

    Airborne microorganism level is an important indoor air quality indicator, yet it has not been well documented for laying-hen houses in the United States. As a part of the Coalition for Sustainable Egg Supply (CSES) environmental monitoring project, this study comparatively monitored the concentrations and emissions of airborne total and Gram-negative (Gram(-)) bacteria in three types of commercial laying-hen houses, i.e., conventional cage (CC), aviary (AV), and enriched colony (EC) houses, over a period of eight months covering the mid and late stages of the flock cycle. It also delineated the relationship between airborne total bacteria and particulate matter smaller than 10 μm in aerodynamic diameter (PM10). The results showed airborne total bacteria concentrations (log CFU/m(3)) of 4.7 ± 0.3 in CC, 6.0 ± 0.8 in AV, and 4.8 ± 0.3 in EC, all being higher than the level recommended for human environment (3.0 log CFU/m(3)). The much higher concentrations in AV arose from the presence of floor litter and hen activities on it, as evidenced by the higher concentrations in the afternoon (with litter access) than in the morning (without litter access). The overall means and standard deviation of airborne total bacteria emission rates, in log CFU/[h-hen] (or log CFU/[h-AU], AU = animal unit or 500 kg live weight) were 4.8 ± 0.4 (or 7.3 ± 0.4) for CC, 6.1 ± 0.7 (or 8.6 ± 0.7) for AV, and 4.8 ± 0.5 (or 7.3 ± 0.5) for EC. Both concentration and emission rate of airborne total bacteria were positively related to PM10 Gram(-) bacteria were present at low concentrations in all houses; and only 2 samples (6%) in CC, 7 (22%) samples in AV, and 2 (6%) samples in EC out of 32 air samples collected in each house were found positive with Gram(-) bacteria. The concentration of airborne Gram(-) bacteria was estimated to be <2% of the total bacteria. Total bacteria counts in manure on belt (in all houses) and floor litter (only in AV) were similar; however, the manure had

  6. Observations of nonmethane organic compounds during ARCTAS - Part 1: Biomass burning emissions and plume enhancements

    NASA Astrophysics Data System (ADS)

    Hornbrook, R. S.; Blake, D. R.; Diskin, G. S.; Fried, A.; Fuelberg, H. E.; Meinardi, S.; Mikoviny, T.; Richter, D.; Sachse, G. W.; Vay, S. A.; Walega, J.; Weibring, P.; Weinheimer, A. J.; Wiedinmyer, C.; Wisthaler, A.; Hills, A.; Riemer, D. D.; Apel, E. C.

    2011-11-01

    Mixing ratios of a large number of nonmethane organic compounds (NMOCs) were observed by the Trace Organic Gas Analyzer (TOGA) on board the NASA DC-8 as part of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign. Many of these NMOCs were observed concurrently by one or both of two other NMOC measurement techniques on board the DC-8: proton-transfer-reaction mass spectrometry (PTR-MS) and whole air canister sampling (WAS). A comparison of these measurements to the data from TOGA indicates good agreement for the majority of co-measured NMOCs. The ARCTAS study, which included both spring and summer deployments, provided opportunities to sample a large number of biomass burning (BB) plumes with origins in Asia, California and central Canada, ranging from very recent emissions to plumes aged one week or more. For this analysis, BB smoke interceptions were grouped by flight, source region and, in some cases, time of day, generating 40 identified BB plumes for analysis. Normalized excess mixing ratios (NEMRs) to CO were determined for each of the 40 plumes for up to 19 different NMOCs or NMOC groups. Although the majority of observed NEMRs for individual NMOCs or NMOC groups were in agreement with previously-reported values, the observed NEMRs to CO for ethanol, a rarely quantified gas-phase trace gas, ranged from values similar to those previously reported, to up to an order of magnitude greater. Notably, though variable between plumes, observed NEMRs of individual light alkanes are highly correlated within BB emissions, independent of estimated plume ages. BB emissions of oxygenated NMOC were also found to be often well-correlated. Using the NCAR Master Mechanism chemical box model initialized with concentrations based on two observed scenarios, fresh Canadian BB and fresh Californian BB, decreases are predicted for the low molecular weight carbonyls (i.e. formaldehyde, acetaldehyde, acetone and methyl ethyl

  7. Alternate-Fueled Combustor-Sector Performance. Parts A and B; (A) Combustor Performance; (B) Combustor Emissions

    NASA Technical Reports Server (NTRS)

    Shouse, D. T.; Hendricks, R. C.; Lynch, A.; Frayne, C. W.; Stutrud, J. S.; Corporan, E.; Hankins, T.

    2012-01-01

    Alternate aviation fuels for military or commercial use are required to satisfy MIL-DTL-83133F(2008) or ASTM D 7566 (2010) standards, respectively, and are classified as "drop-in" fuel replacements. To satisfy legacy issues, blends to 50% alternate fuel with petroleum fuels are certified individually on the basis of processing and assumed to be feedstock agnostic. Adherence to alternate fuels and fuel blends requires "smart fueling systems" or advanced fuel-flexible systems, including combustors and engines, without significant sacrifice in performance or emissions requirements. This paper provides preliminary performance (Part A) and emissions and particulates (Part B) combustor sector data. The data are for nominal inlet conditions at 225 psia and 800 F (1.551 MPa and 700 K), for synthetic-paraffinic-kerosene- (SPK-) type (Fisher-Tropsch (FT)) fuel and blends with JP-8+100 relative to JP-8+100 as baseline fueling. Assessments are made of the change in combustor efficiency, wall temperatures, emissions, and luminosity with SPK of 0%, 50%, and 100% fueling composition at 3% combustor pressure drop. The performance results (Part A) indicate no quantifiable differences in combustor efficiency, a general trend to lower liner and higher core flow temperatures with increased FT fuel blends. In general, emissions data (Part B) show little differences, but with percent increase in FT-SPK-type fueling, particulate emissions and wall temperatures are less than with baseline JP-8. High-speed photography illustrates both luminosity and combustor dynamic flame characteristics.

  8. Odor and chemical emissions from dairy and swine facilities: Part 1 - project overview and collection methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock facilities have received numerous criticisms due to their emissions of odorous air and chemicals. Hence, there is a significant need for odor emission factors and identification of principle odorous chemicals. Odor emission factors are used as inputs to odor setback models, while chemica...

  9. Odor and odorous chemical emissions from animal buildings: Part 6.Odor activity value

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a growing concern with air and odor emissions from agricultural facilities. A supplementary research project was conducted to complement the U.S. National Air Emissions Monitoring Study (NAEMS). The overall goal of the project was to establish odor and chemical emission factors for animal...

  10. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2 Emissions...

  11. Exposure and Emissions Monitoring during Carbon Nanofiber Production—Part II: Polycyclic Aromatic Hydrocarbons

    PubMed Central

    BIRCH, M. EILEEN

    2015-01-01

    Production of carbon nanofibers and nanotubes (CNFs/CNTs) and their composite products is increasing globally. High-volume production may increase the exposure risks for workers who handle these materials. Though health effects data for CNFs/CNTs are limited, some studies raise serious health concerns. Given the uncertainty about their potential hazards, there is an immediate need for toxicity data and field studies to assess exposure to CNFs/CNTs. An extensive study was conducted at a facility that manufactures and processes CNFs. Filter, sorbent, cascade impactor, bulk, and microscopy samples, combined with direct-reading instruments, provided complementary information on air contaminants. Samples were analyzed for organic and elemental carbon (OC and EC), metals, and polycyclic aromatic hydrocarbons (PAHs), with EC as a measure of CNFs. Transmission electron microscopy with energy-dispersive X-ray spectroscopy also was applied. Fine/ultrafine iron-rich soot, PAHs, and carbon monoxide were production byproducts. Direct-reading instrument results were reported previously [Evans DE et al. (Aerosol monitoring during carbon nanofiber production: mobile direct-reading sampling. Ann Occup Hyg 2010; 54:514–31)]. Results for time-integrated samples are reported as companion papers in this issue. OC and EC, metals, and microscopy results are reported in Part I [Birch ME et al. (Exposure and emissions monitoring during carbon nanofiber production—Part I: elemental carbon and iron–soot aerosols. Ann Occup Hyg 2011; 55: 1016–36.)] whereas results for PAHs are reported here. Naphthalene and acenaphthylene were the dominant PAHs with average concentrations ranging from 115 to 336 μg m−3 and 35 to 84 μg m−3, respectively. Concentrations of other PAHs ranged from ~1 to 10 μg m−3. PMID:21976308

  12. 40 CFR Table I-6 to Subpart I - Table I-6 to Subpart I of Part 98-Table I-6 to Subpart I of Part 98-Default Emission Factors (1...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS...-Table I-6 to Subpart I of Part 98-Default Emission Factors (1-Uij) for Gas Utilization Rates (Uij) and... I of Part 98-Table I-6 to Subpart I of Part 98—Default Emission Factors (1-Uij) for Gas...

  13. 40 CFR Table I-7 to Subpart I - Table I-7 to Subpart I of Part 98-Table I-7 to Subpart I of Part 98-Default Emission Factors (1...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS...-Table I-7 to Subpart I of Part 98-Default Emission Factors (1-Uij) for Gas Utilization Rates (Uij) and... I of Part 98-Table I-7 to Subpart I of Part 98—Default Emission Factors (1-Uij) for Gas...

  14. 23 CFR Appendix A to Part 772 - National Reference Energy Mean Emission Levels as a Function of Speed

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false National Reference Energy Mean Emission Levels as a Function of Speed A Appendix A to Part 772 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF... Function of Speed EC14OC91.013...

  15. Characterizing biofuel combustion with patterns of real-time emission data (PaRTED).

    PubMed

    Chen, Yanju; Roden, Christoph A; Bond, Tami C

    2012-06-01

    Emission properties and quantities from combustion sources can vary significantly during operation, and this characteristic variability is hidden in the traditional presentation of emission test averages. As a complement to the emission test averages, we introduce the notion of statistical pattern analysis to characterize temporal fluctuations in emissions, using cluster analysis and frequency plots. We demonstrate this approach by comparing emissions from traditional and improved wood-burning cookstoves under in-field conditions, and also to contrast laboratory and in-field cookstove performance. Compared with traditional cookstoves, improved cookstoves eliminate emissions that occur at low combustion efficiency. For cookstoves where the only improvement is an insulated combustion chamber, this change results in emission of more light-absorbing (black) particles. When a chimney is added, the stoves produce more black particles but also have reduced emission factors. Laboratory tests give different results than in-field tests, because they fail to reproduce a significant fraction of low-efficiency events, spikes in particulate matter (PM) emissions, and less-absorbing particles. These conditions should be isolated and replicated in future laboratory testing protocols to ensure that stove designs are relevant to in-use operation. PMID:22533493

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

    PubMed

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

    2012-10-01

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

  17. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 7 2011-07-01 2011-07-01 false Determination of Emission Rate Change...

  18. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 7 2010-07-01 2010-07-01 true Determination of Emission Rate Change...

  19. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 8 2013-07-01 2013-07-01 false Determination of Emission Rate Change...

  20. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 60—Determination of Emission Rate Change 1.Introduction 1.1The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 8 2012-07-01 2012-07-01 false Determination of Emission Rate Change...

  1. 40 CFR Appendix C to Part 60 - Determination of Emission Rate Change

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 60—Determination of Emission Rate Change 1. Introduction 1.1 The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the... 40 Protection of Environment 8 2014-07-01 2014-07-01 false Determination of Emission Rate Change...

  2. Odor and odorous chemical emissions from animal buildings: part 4-correlations between sensory and chemical measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study supplemented the National Air Emissions Monitoring Study (NAEMS) with one year of comprehensive measurements of odor emission at five swine and four dairy buildings. The measurements included both standard human sensory measurements using dynamic forced-choice olfactometry and chemical an...

  3. Odor and odorous chemical emissions from animal buildings: Part 4 - correlations between sensory and chemical measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study supplemented the National Air Emissions Monitoring Study (NAEMS) by making comprehensive measurements, over a full calendar year, of odor emissions from five swine and four dairy rooms/buildings (subset of the total number of buildings monitored for the NAEMS project). The measurements ma...

  4. Berreman mode and epsilon near zero mode.

    PubMed

    Vassant, Simon; Hugonin, Jean-Paul; Marquier, Francois; Greffet, Jean-Jacques

    2012-10-01

    In this paper, we discuss the existence of an electromagnetic mode propagating in a thin dielectric film deposited on a metallic film at the particular frequency such that the dielectric permittivity vanishes. We discuss the remarkable properties of this mode in terms of extreme subwavelength mode confinment and its potential applications. We also discuss the link between this mode, the IR absorption peak on a thin dielectric film known as Berreman effect and the surface phonon polariton mode at the air/dielectric interface. Finally, we establish a connection with the polarization shift occuring in quantum wells. PMID:23188363

  5. Development of hourly probabilistic utility NO x emission inventories using time series techniques: Part I—univariate approach

    NASA Astrophysics Data System (ADS)

    Abdel-Aziz, Amr; Frey, H. Christopher

    Historical data regarding hourly variability in coal-fired power plant unit emissions based upon continuous emission monitoring enables estimation of the likely range of possible values in the near future for purposes of air quality modeling. Analyses were conducted for 32 units for a base case in 1995, an alternative 1998 case, and a 2007 future scenario case. Hourly inter-unit uncertainty was assumed to be independent. Univariate stochastic time series models were employed to quantify hourly uncertainty in capacity and emission factors. Ordinary least-squares regression models were used to quantify hourly uncertainty in heat rate. The models were used to develop an hourly probabilistic emission inventory for a 4-day period. There was significant autocorrelation for time lags 1, 2, 23, and 24 for the capacity and emission factor and a 24 h cyclical pattern for the capacity factor. The uncertainty ranges for hourly emissions were found to vary for different hours of the day, with 95% probability ranges of typically ±20-40% of the mean. For the 1995 case, the 95% confidence interval for the daily inventory was 510-633 t/d, representing approximately ±10% uncertainty with respect to the average value of 576 t/d. Inter-annual changes in the mean and variability were assessed by comparison of 1998 data with 1995 data. The daily inventory for the 2007 scenario had an uncertainty range of ±8% of the average value of 175 t/d. The substantial autocorrelation in capacity and emission factor, and the cyclic effect for capacity factor, indicate the importance of accounting for time series effects in estimation of uncertainty in hourly emissions. Additional work is recommended to account for inter-unit dependence, which is addressed in Part 2.

  6. Application of exoelectron emission for quality control of gas-turbine engine parts

    NASA Astrophysics Data System (ADS)

    Kortov, V. S.; Sulima, A. M.; Slesarev, A. I.; Shorin, V. V.

    1981-01-01

    The paper deals with the application of exoelectron emission to the nondestructive testing of the physicochemical state of the surface layer of turbine engine blades and other components. The effectiveness of the method in detecting fatigue damage is demonstrated.

  7. B Stars with and without emission lines, parts 1 and 2

    NASA Technical Reports Server (NTRS)

    Underhill, A. (Editor); Doazan, V. (Editor)

    1982-01-01

    The spectra for B stars for which emission lines occur not on the main sequence, but only among the supergiants, and those B stars for which the presence of emission in H ahlpa is considered to be a significant factor in delineating atmospheric structure are examined. The development of models that are compatible with all known facts about a star and with the laws of physics is also discussed.

  8. 350 nm Broadband Supercontinuum Generation Using Dispersion Engineered Near Zero Ultraflat Square-Lattice PCF around 1.55 μm and Fabrication Tolerance Analysis

    PubMed Central

    Roy Chaudhuri, Partha

    2014-01-01

    In this work, a new design of ultraflat dispersion PCF based on square-lattice geometry with all uniform air holes towards broadband smooth SCG around the C-band of wavelength has been presented. The air hole of the inner ring was infiltrated with liquid of certain refractive indices. Numerical investigations establish a near zero ultraflattened dispersion of 0 ± 0.78 ps/nm/km in a wavelength range of 1496 nm to 2174 nm (678 nm bandwidth) covering most of the communications bands with the first zero dispersion wavelength around 1.54 μm. With the optimized ultraflattened fiber, we have achieved a broadband SC spectrum with FWHM of 350 nm with the central wavelength of 1550 nm with less than a meter long of the fiber by using a picosecond pulse laser. We have also analyzed the sensitivity of the optimized dispersion design by small variations from the optimum value of the geometrical structural parameters. Our investigations establish that for a negative change of PCF parameters, the profile retains the smooth and flat SCG spectra; however, for a positive change, the smooth and a flat spectrum is lost. The new design of the fiber will be capable of covering huge diverse field of DWDM sources, spectroscopy, meteorology, optical coherence tomography, and optical sensing. PMID:27355018

  9. High permittivity and near-zero τɛ dielectrics Ca0.36Sr0.64TiO3-Li0.5Nd0.5TiO3 for multilayer ceramic capacitors

    NASA Astrophysics Data System (ADS)

    Wang, Xiaochuan; Liu, Yawen; Wang, Xiaohong; Lu, Wenzhong

    2015-11-01

    The microstructure and dielectric properties of (1 - x)Ca0.36Sr0.64TiO3-xLi0.5Nd0.5TiO3 (0 ≤ x ≤ 1) [abbreviated as (1 - x)CST-xLNT] solid solutions were investigated in this study. X-ray diffraction results showed that the samples exhibited a single cubic phase with x ≤ 0.5, whereas increasing LNT content resulted in a structural change from cubic to tetragonal phase in when x > 0.5. The permittivity (ɛr) decreased with increasing x, while the dielectric loss (tan δ) increased and then decreased at x = 1.0. The temperature dependence of ɛr and tan δ at 1 MHz for the (1 - x)CST-xLNT ceramics was also investigated. The temperature coefficient of the permittivity (τɛ) increased from highly negative values to positive values with increasing x. A near-zero τɛ was achieved at x = 0.57. Optimised dielectric properties were estimated to be ɛr = 227, tan δ = 0.043 and τɛ = 12 ppm/°C. Therefore, the 0.43CST-0.57LNT ceramic is proposed as a promising candidate material for multilayer ceramic capacitors with good temperature stability and high capacitance.

  10. 350 nm Broadband Supercontinuum Generation Using Dispersion Engineered Near Zero Ultraflat Square-Lattice PCF around 1.55 μm and Fabrication Tolerance Analysis.

    PubMed

    Maji, Partha Sona; Roy Chaudhuri, Partha

    2014-01-01

    In this work, a new design of ultraflat dispersion PCF based on square-lattice geometry with all uniform air holes towards broadband smooth SCG around the C-band of wavelength has been presented. The air hole of the inner ring was infiltrated with liquid of certain refractive indices. Numerical investigations establish a near zero ultraflattened dispersion of 0 ± 0.78 ps/nm/km in a wavelength range of 1496 nm to 2174 nm (678 nm bandwidth) covering most of the communications bands with the first zero dispersion wavelength around 1.54 μm. With the optimized ultraflattened fiber, we have achieved a broadband SC spectrum with FWHM of 350 nm with the central wavelength of 1550 nm with less than a meter long of the fiber by using a picosecond pulse laser. We have also analyzed the sensitivity of the optimized dispersion design by small variations from the optimum value of the geometrical structural parameters. Our investigations establish that for a negative change of PCF parameters, the profile retains the smooth and flat SCG spectra; however, for a positive change, the smooth and a flat spectrum is lost. The new design of the fiber will be capable of covering huge diverse field of DWDM sources, spectroscopy, meteorology, optical coherence tomography, and optical sensing. PMID:27355018

  11. 40 CFR Table W - 5 of Subpart W of Part 98-Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Methane Emission Factors for Liquefied Natural Gas (LNG) Storage W Table W Protection of Environment... Petroleum and Natural Gas Systems Definitions. Pt. 98, Subpt. W, Table W-5 Table W-5 of Subpart W of Part 98—Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage LNG storage Emission factor...

  12. 40 CFR Table W - 5 of Subpart W of Part 98-Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Methane Emission Factors for Liquefied Natural Gas (LNG) Storage W Table W Protection of Environment... Petroleum and Natural Gas Systems Definitions. Pt. 98, Subpt. W, Table W-5 Table W-5 of Subpart W of Part 98—Default Methane Emission Factors for Liquefied Natural Gas (LNG) Storage LNG storage Emission factor...

  13. Boiler briquette coal versus raw coal: Part I--Stack gas emissions.

    PubMed

    Ge, S; Bai, Z; Liu, W; Zhu, T; Wang, T; Qing, S; Zhang, J

    2001-04-01

    Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BB-coal were 2.51 for PM10, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/steam conversion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for CO, while those of the BB-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also presented for both types of coal tested in the study. PMID:11321909

  14. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part II. CO, HC and NOx.

    PubMed

    Huang, Xiaoyan; Wang, Yang; Xing, Zhenyu; Du, Ke

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles. PMID:27219504

  15. Thermal Return Reflection Method for Resolving Emissivity and Temperature in Radiometric Measurements

    SciTech Connect

    Woskov, Paul P.; Sundaram, S. K.

    2002-11-15

    A radiometric method for resolving the emissivity, e, and temperature, T, in thermal emission measurements is presented. Thermal radiation from a viewed source is split by a beamsplitter between a radiometer and a mirror aligned to return a part of the thermal radiation back to the source. The ratio of the thermal signal with and without a return reflection provides a measurement of the emissivity without need of any other probing sources. The analytical expressions that establish this relationship are derived taking into account waveguide/optic losses and sources between the radiometer and viewed sample. The method is then applied to thermal measurements of several refractory materials at temperatures up to 1150 ?C. A 137 GHz radiometer is used to measure the emissivity and temperature of an alumina brick, an Inconel 690 plate, and two grades of silicon carbide. Reasonable temperature agreement is achieved with an independent thermocouple measurement. However, when the emissivity approaches zero, as in the case of the Inconel plate, radiometric temperature determinations are inaccurate, though an emissivity near zero is correctly measured. This method is expected to be of considerable value to non-contact thermal analysis applications of materials.

  16. 40 CFR 1060.705 - How do I certify components to an emission level other than the standard under this part or use...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-system component may be certified to a family emission limit (FEL) instead of the otherwise applicable emission standard. Note that the exhaust standard-setting part may apply maximum values for an FEL (i.e., FEL caps). (a) Requirements for certifying component manufacturers. See subpart C of this part...

  17. 40 CFR 1060.705 - How do I certify components to an emission level other than the standard under this part or use...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-system component may be certified to a family emission limit (FEL) instead of the otherwise applicable emission standard. Note that the exhaust standard-setting part may apply maximum values for an FEL (i.e., FEL caps). (a) Requirements for certifying component manufacturers. See subpart C of this part...

  18. 40 CFR 1060.705 - How do I certify components to an emission level other than the standard under this part or use...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-system component may be certified to a family emission limit (FEL) instead of the otherwise applicable emission standard. Note that the exhaust standard-setting part may apply maximum values for an FEL (i.e., FEL caps). (a) Requirements for certifying component manufacturers. See subpart C of this part...

  19. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Peaking Units

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Peaking Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2...

  20. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for Gas-Fired and Oil-Fired Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units 1....

  1. Potential radionuclide emissions from stacks on the Hanford site, Part 1: Dose assessment

    SciTech Connect

    Davis, W.E.; Barnett, J.M.

    1995-02-01

    On February 3, 1993, the U.S. Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the U.S. Environmental Protection Agency, Region 10. The Compliance Order requires RL to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission monitoring requirements in 40 CFR 61, Subpart H, and to continuously monitor radionuclide emissions in accordance with requirements in 40 CFR 61.93. The Information Request required RL to provide a written Compliance Plan to meet the requirements of the Compliance Order. A Compliance Plan was submitted to EPA, Region 10, on April 30, 1993. The Compliance Plan specified that a dose assessment would be performed for 84 Westinghouse Hanford Company stacks registered with the Washington State Department of Health on the Hanford Site. Stacks that have the potential emissions to cause an effective dose equivalent to a maximum exposed individual greater than 0.1 mrem/y must be monitored continuously for radionuclide emissions. Five methods were approved by EPA, Region 10 for performing the assessments: Release Fractions from Appendix D of 40 CFR 61, Back Calculations Using A HEPA Filtration Factor, Nondestructive Assay of HEPA Filters, A Spill Release Fraction, and Upstream of HEPA Filter Air Concentrations. The first two methods were extremely conservative for estimating releases. The third method, which used a state-of-the-art portable gamma spectrometer, yielded surprising results from the distribution of radionuclides on the HEPA filters. All five methods are described. Assessments using a HEPA Filtration Factor for back calculations identified 32 stacks that would have emissions that would cause an EDE to the MEI greater than 0.1 mrem y{sup {minus}1}. The number was reduced to 15 stacks when the other methods were applied. The paper discusses reasons for the overestimates.

  2. Size and composition distributions of particulate matter emissions: part 2--heavy-duty diesel vehicles.

    PubMed

    Robert, Michael A; Kleeman, Michael J; Jakober, Christopher A

    2007-12-01

    Particulate matter (PM) emissions from heavy-duty diesel vehicles (HDDVs) were collected using a chassis dynamometer/dilution sampling system that employed filter-based samplers, cascade impactors, and scanning mobility particle size (SMPS) measurements. Four diesel vehicles with different engine and emission control technologies were tested using the California Air Resources Board Heavy Heavy-Duty Diesel Truck (HHDDT) 5 mode driving cycle. Vehicles were tested using a simulated inertial weight of either 56,000 or 66,000 lb. Exhaust particles were then analyzed for total carbon, elemental carbon (EC), organic matter (OM), and water-soluble ions. HDDV fine (< or =1.8 microm aerodynamic diameter; PM1.8) and ultrafine (0.056-0.1 microm aerodynamic diameter; PM0.1) PM emission rates ranged from 181-581 mg/km and 25-72 mg/km, respectively, with the highest emission rates in both size fractions associated with the oldest vehicle tested. Older diesel vehicles produced fine and ultrafine exhaust particles with higher EC/OM ratios than newer vehicles. Transient modes produced very high EC/OM ratios whereas idle and creep modes produced very low EC/OM ratios. Calcium was the most abundant water-soluble ion with smaller amounts of magnesium, sodium, ammonium ion, and sulfate also detected. Particle mass distributions emitted during the full 5-mode HDDV tests peaked between 100-180 nm and their shapes were not a function of vehicle age. In contrast, particle mass distributions emitted during the idle and creep driving modes from the newest diesel vehicle had a peak diameter of approximately 70 nm, whereas mass distributions emitted from older vehicles had a peak diameter larger than 100 nm for both the idle and creep modes. Increasing inertial loads reduced the OM emissions, causing the residual EC emissions to shift to smaller sizes. The same HDDV tested at 56,000 and 66,000 lb had higher PM0.1 EC emissions (+22%) and lower PM0.1 OM emissions (-38%) at the higher load

  3. Acoustic emission-microstructural relationships in ferritic steels. Part 1: The effect of cooling rate

    NASA Astrophysics Data System (ADS)

    Wadley, H. N. G.; Scruby, C. B.

    1985-06-01

    Acoustic emission is controlled during deformation and fracture by the dynamics of dislocation motion and crack advance. The nature of the relationship between defect dynamics and acoustic emission in tensile samples of specially prepared low alloy steels containing 3.25 wt.% Ni, 1 wt.% Mn and a variable carbon content from 0.06 to 0.49 wt.% is studied. The most energetic signals are from microstructures with an initially low dislocation density and a ferrite dimension of approx. 10 microns, indicating the propagation of high velocity dislocations in ferrite to be the origin of acoustic emission during deformation. This is consistent with a model in which the product of glide distance and velocity (which are both controlled by microstructure) determines the amplitude of the acoustic emission. During subcritical micro-fracture, intergranular and alternating shear modes of microcracking in high strength conditions generate detectable signals. Both involve the rapid growth of cracks over distances of 10 to 100 micron. The ductile dimple mode of fracture is found to generate no detectable signals despite wide variations in dimple spacing and fracture stress. This is consistent with the recognized view that such fracture occurs under essentially static conditions.

  4. 40 CFR Appendix G to Part 75 - Determination of CO2 Emissions

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... tons/day) from the combustion of fossil fuels. Where fuel flow is measured in a common pipe header (i.e., a pipe carrying fuel for multiple units), the owner or operator may use the procedures in section 2... following procedures to estimate daily CO2 mass emissions from the combustion of fossil fuels. The...

  5. 40 CFR Appendix G to Part 75 - Determination of CO2 Emissions

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... tons/day) from the combustion of fossil fuels. Where fuel flow is measured in a common pipe header (i.e., a pipe carrying fuel for multiple units), the owner or operator may use the procedures in section 2... following procedures to estimate daily CO2 mass emissions from the combustion of fossil fuels. The...

  6. 40 CFR 1060.101 - What evaporative emission requirements apply under this part?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD... installed in a way that prevents exposing the carbon to water or liquid fuel. (2) Fuel-line fittings. The... systems so they cause or contribute to an unreasonable risk to public health, welfare, or safety...

  7. 40 CFR Appendix S to Part 51 - Emission Offset Interpretative Ruling

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... including indirect sources) under 40 CFR subpart I and section 129 of the Clean Air Act Amendments of 1977... that is located in an ozone transport region or which would locate in an area designated in 40 CFR part... as exceeding a NAAQS (nonattainment area) under 40 CFR part 81, subpart C, or for any area...

  8. 40 CFR Appendix S to Part 51 - Emission Offset Interpretative Ruling

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... including indirect sources) under 40 CFR subpart I and section 129 of the Clean Air Act Amendments of 1977... that is located in an ozone transport region or which would locate in an area designated in 40 CFR part... as exceeding a NAAQS (nonattainment area) under 40 CFR part 81, subpart C, or for any area...

  9. 40 CFR Appendix P to Part 51 - Minimum Emission Monitoring Requirements

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... must include in order to be approved under the provisions of 40 CFR 51.165(b). These requirements... is: 1.2.1 Subject to a new source performance standard promulgated in 40 CFR part 60 pursuant to... Requirements P Appendix P to Part 51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  10. Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy - Part 2: Wind propagation and emission rates

    NASA Astrophysics Data System (ADS)

    Krueger, A.; Stremme, W.; Harig, R.; Grutter, M.

    2013-01-01

    A technique for measuring two-dimensional (2-D) plumes of volcanic gases with thermal emission spectroscopy was described in Part 1 by Stremme et al. (2012a). In that paper the instrumental aspects as well as retrieval strategies for obtaining the slant column images of SO2 and SiF4, as well as animations of particular events observed at the Popocatépetl volcano, were presented. This work focuses on the procedures for determining the propagation speed of the gases and estimating an emission rate from the given image sequences. A 2-D column density distribution of a volcanic gas, available as time-consecutive frames, provides information of a projected wind field and the average velocity at which the volcanic plume is propagating. This information is valuable since the largest uncertainties when calculating emission rates of the gases using remote sensing techniques arise from propagation velocities which are often inadequately assumed. The presented reconstruction method solves the equation of continuity as an ill-posed problem using mainly a Tikhonov-like regularisation. It is observed from the available data sets that if the main direction of propagation is perpendicular to the line-of-sight, the algorithm works well for SO2, which has the strongest signals, and also for SiF4 in some favourable cases. Due to the similarity of the algorithm used here with the reconstruction methods used for profile retrievals based on optimal estimation theory, diagnostic tools like the averaging kernels can be calculated in an analogous manner and the information can be quantified as degrees of freedom. Thus, it is shown that the combination of wind field and column distribution of the gas plume can provide the emission rate of the volcano both during day and night.

  11. Evaluation of the emissions from low-sulfur and biodiesel fuel used in a heavy-duty diesel truck during on-road operation

    EPA Science Inventory

    In October of 2004, EPA's National Risk Management Research Laboratory investigated the emissions from diesel powered tractor-trailer operating along a highway at near-zero grade. In place of a dynamometer and standard dilution tunnel, the Diesel Emissions Aerosol Laboratory (DEA...

  12. Part I - burner and ESP improvements for reduction of particulate and NO{sub x} emissions

    SciTech Connect

    Pickles, R.

    1994-08-01

    The Coleson Cove Generating Station is a 3 x 350 MW plant located on the Bay of Fundy in Southern New Brunswick, Canada. The plant was designed to burn a range of fuel oils including distillates, crudes, and residual oil. The original fuel was a light high sulphur residual. The fuel supply changed to Venezuelan high vanadium residual as a result of economics. Typical Venezuelan analysis is shown, together with the design fuel analysis. A result of this change was a significant increase in emissions. The plant was designed with electrostatic precipitators by Joy Technologies with 90% collection efficiency. Based on the design criteria problems with the ash handling system, the precipitators were not operated consistently for a significant period. As a result of the above conditions and because of high emissions, a program of combustion improvements was initiated followed by upgrading of the precipitator and ash handling system.

  13. 40 CFR Appendix I to Part 1045 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (since the end of the phase-in period specified in 40 CFR 91.104): (1) For engines at or below 4.3 kW... applies: STD = 6.00 + 0.250 · (151 + 557/P0.9) Where: STD = The HC+NOX emission standard, in g/kW-hr. P = The average power of an engine family, in kW. (b) See 40 CFR 91.104 for standards that applied...

  14. 40 CFR Appendix I to Part 1045 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (since the end of the phase-in period specified in 40 CFR 91.104): (1) For engines at or below 4.3 kW... applies: STD = 6.00 + 0.250 · (151 + 557/P0.9) Where: STD = The HC+NOX emission standard, in g/kW-hr. P = The average power of an engine family, in kW. (b) See 40 CFR 91.104 for standards that applied...

  15. 40 CFR Appendix I to Part 1045 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (since the end of the phase-in period specified in 40 CFR 91.104): (1) For engines at or below 4.3 kW... applies: STD = 6.00 + 0.250 · (151 + 557/P0.9) Where: STD = The HC+NOX emission standard, in g/kW-hr. P = The average power of an engine family, in kW. (b) See 40 CFR 91.104 for standards that applied...

  16. 40 CFR Appendix I to Part 1045 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (since the end of the phase-in period specified in 40 CFR 91.104): (1) For engines at or below 4.3 kW... applies: STD = 6.00 + 0.250 · (151 + 557/P0.9) Where: STD = The HC+NOX emission standard, in g/kW-hr. P = The average power of an engine family, in kW. (b) See 40 CFR 91.104 for standards that applied...

  17. 40 CFR Appendix I to Part 1045 - Summary of Previous Emission Standards

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (since the end of the phase-in period specified in 40 CFR 91.104): (1) For engines at or below 4.3 kW... = The average power of an engine family, in kW. (b) See 40 CFR 91.104 for standards that applied to... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Pt....

  18. The annual ammonia budget of fertilised cut grassland - Part 1: Micrometeorological flux measurements and emissions after slurry application

    NASA Astrophysics Data System (ADS)

    Spirig, C.; Flechard, C. R.; Ammann, C.; Neftel, A.

    2009-10-01

    Two commercial ammonia (NH3) analysers were customised to allow continuous measurements of vertical concentration gradients. The gradients were used to derive ammonia exchange fluxes above a managed grassland site at Oensingen (Switzerland) by application of the aerodynamic gradient method (AGM). The semi-continuous measurements during 1.5 years covered five complete growth-cut cycles and included six applications of liquid cattle slurry. The average accuracy of the flux measurements during conditions of well established turbulence was 20% and the detection limit 10 ng NH3 m-2 s-1, hence sufficient for studying the background exchange of NH3. Quantifying emissions after slurry applications required the application of elaborate interpolations because of difficulties capturing the initial emissions during manure spreading in some parts of the experiments. The emissions were also calculated with a mass balance method (MBM) yielding similar fluxes. NH3 losses after slurry application expressed as percentage of emitted nitrogen versus applied total ammoniacal nitrogen (TAN) varied between 4 and 19%, which is lower than typical values for broadspreading of liquid manure. The comparatively low emission factors appear to be a consequence of the rather thin slurry applied here and soil properties favouring ammonium adsorption.

  19. [Emission of microorganisms from sewage treatment plants depending upon construction differences of single structural parts].

    PubMed

    Eikmann, T; Schröder, S; Pieler, J; Bahr, H; Einbrodt, H J

    1986-04-01

    In order to examine the influence exerted by the differing design of individual water treatment plant units on the emission rate of micro-organisms and the associated degree of exposure to which plant personnel is subjected, measurements were taken at three different types of treatment plants. Measurements were made using "Biotest" RCS Air Samplers. The total count of colonies was determined by means of Agar Strips GK-A (tryptic soy agar). Enterobacteriaceae were quantitatively ascertained using Agar Strips C (MacConkey agar), particular attention being paid to the determination of the coliform bacteria as faeces indicators. Agar Strips S (mannitol salt agar) were used to measure the count of staphylococci using Agar Strips HS (rosa Bengal streptomycin agar). Before taking measurements, the prevailing climatic conditions were recorded. It could be ascertained that the enclosure of the inflow area (screw conveyor pump station and aerated grit removal tank) lead to a considerable increase in the concentration of microorganisms in the air within the housing. The values dropped however, when adequate ventilation was provided. Differing oxygen in the activated sludge tanks - finebubble aeration at the tank bottom or the blowing in of air via centrifugal blowers - lead to large variations in the emission rates. However, the less the waste water is agitated, the lower the emission rates. In the case of fine-bubble aeration, rates which are also normally to be found in the "non-burdened" outside air were even recorded close to the aeration tank. In cases of centrifugal blower, the aeration tank should be covered with a shield. With this type of aeration the waste water is emitted radially towards the walls of the tank. The use of a sprinkler unit on an aeration tank equipped with centrifugal blower - to avoid foam formation on the surface of the water - does not lead to an increase in the already high emission rate. An increase in air pollution through mould fungi from

  20. Status of Geological Storage of CO2 as Part of Negative Emissions Strategy

    NASA Astrophysics Data System (ADS)

    Benson, S. M.

    2014-12-01

    Recent analyses show that many GHG stabilization scenarios require technologies that permanently extract CO2 from the atmosphere -so-called "net negative emissions." Among the most promising negative emissions approaches is bioenergy with carbon capture and storage (BECCS). The most mature options for CO2 storage are in sedimentary rocks located in thick sedimentary basins. Within those basins, CO2 can be stored either in depleted or depleting hydrocarbon formations or in so-called saline aquifers. In addition to the economic costs of bioenergy with CO2 capture, key to the success of and scale at which BECCS can contribute to negative emissions is the ability to store quantities on the order of 1 Gt per year of CO2. Today, about 65 Mt of CO2 per year are injected underground for the purposes of enhancing oil recovery (CO2-EOR) or for CO2 storage, the vast majority being for CO2-EOR. Achieving 1 Gt per year of negative emissions will require a 15-fold scale up of the current injection operations. This paper will review the conditions necessary for storage at this scale, identify what has been learned from nearly 2 decades of experience with CO2 storage that provides insight into the feasibility of CO2 storage on this scale, and identify critical issues that remain to be resolved to meet these ambitious negative emissions targets. Critical technological issues include but are not limited to: the amount of CO2 storage capacity that is available and where it is located in relation to biomass energy resources; identification of sustainable injection rates and how this depends on the properties of the geological formation; the extent to which water extraction will be required to manage the magnitude of pressure buildup; identification of regions at high risk for induced seismicity that could damage structures and infrastructure; and selection of sites with a adequate seals to permanently contain CO2. Social, economic and political issues are also important: including the

  1. Uncontrolled combustion of shredded tires in a landfill - Part 1: Characterization of gaseous and particulate emissions

    NASA Astrophysics Data System (ADS)

    Downard, Jared; Singh, Ashish; Bullard, Robert; Jayarathne, Thilina; Rathnayake, Chathurika M.; Simmons, Donald L.; Wels, Brian R.; Spak, Scott N.; Peters, Thomas; Beardsley, Douglas; Stanier, Charles O.; Stone, Elizabeth A.

    2015-03-01

    In summer 2012, a landfill liner comprising an estimated 1.3 million shredded tires burned in Iowa City, Iowa. During the fire, continuous monitoring and laboratory measurements were used to characterize the gaseous and particulate emissions and to provide new insights into the qualitative nature of the smoke and the quantity of pollutants emitted. Significant enrichments in ambient concentrations of CO, CO2, SO2, particle number (PN), fine particulate (PM2.5) mass, elemental carbon (EC), and polycyclic aromatic hydrocarbons (PAH) were observed. For the first time, PM2.5 from tire combustion was shown to contain PAH with nitrogen heteroatoms (a.k.a. azaarenes) and picene, a compound previously suggested to be unique to coal-burning. Despite prior laboratory studies' findings, metals used in manufacturing tires (i.e. Zn, Pb, Fe) were not detected in coarse particulate matter (PM10) at a distance of 4.2 km downwind. Ambient measurements were used to derive the first in situ fuel-based emission factors (EF) for the uncontrolled open burning of tires, revealing substantial emissions of SO2 (7.1 g kg-1), particle number (3.5 × 1016 kg-1), PM2.5 (5.3 g kg-1), EC (2.37 g kg-1), and 19 individual PAH (totaling 56 mg kg-1). A large degree of variability was observed in day-to-day EF, reflecting a range of flaming and smoldering conditions of the large-scale fire, for which the modified combustion efficiency ranged from 0.85 to 0.98. Recommendations for future research on this under-characterized source are also provided.

  2. Thc continuous emission monitoring guidance for part 503 sewage sludge incinerators

    SciTech Connect

    Not Available

    1994-06-30

    The Envrionmental Protection Agency's guidance document for monitoring of total hydrocarbons (THCs) at sewage sludge incinerators was finalized in response to comments received from Federal, State and local government agencies. The document contains recommendations for compliance with these requirements. It addresses installation, calibration, operation, and maintenance procedures for sewage sludge incinerators in the following areas: (1) THC continuous emissions monitoring (CEM); (2) oxygen CEM; (3) moisture CEM; (4) quality assurance; and (5) recordkeeping and reporting. The document will provide guidance for both the interim and long-term sludge permitting programs.

  3. Acoustic emission from single point machining: Part 2, Signal changes with tool wear. Revised

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1989-12-31

    Changes in acoustic emission signal characteristics with tool wear were monitored during single point machining of 4340 steel and Ti-6Al-4V heat treated to several strength levels, 606l-T6 aluminum, 304 stainless steel, 17-4PH stainless steel, 410 stainless steel, lead, and teflon. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristic with wear for a given material may be sufficient to be used to monitor tool wear.

  4. Acoustic emission from single point machining: Part 2, Signal changes with tool wear

    SciTech Connect

    Heiple, C.R.; Carpenter, S.H.; Armentrout, D.L.; McManigle, A.P.

    1989-01-01

    Changes in acoustic emission signal characteristics with tool wear were monitored during single point machining of 4340 steel and Ti-6Al-4V heat treated to several strength levels, 606l-T6 aluminum, 304 stainless steel, 17-4PH stainless steel, 410 stainless steel, lead, and teflon. No signal characteristic changed in the same way with tool wear for all materials tested. A single change in a particular AE signal characteristic with tool wear valid for all materials probably does not exist. Nevertheless, changes in various signal characteristic with wear for a given material may be sufficient to be used to monitor tool wear.

  5. Effect of Sea Breeze on Air Pollution in the Greater Athens Area. Part II: Analysis of Different Emission Scenarios.

    NASA Astrophysics Data System (ADS)

    Grossi, Paola; Thunis, Philippe; Martilli, Alberto; Clappier, Alain

    2000-04-01

    The Mediterranean Campaign of Photochemical Tracers-Transport and Chemical Evolution that took place in the greater Athens area from 20 August to 20 September 1994 has confirmed the role of sea-breeze circulation in photochemical smog episodes that had been suggested already by a number of experiments and numerical studies.The meteorological and photochemical modeling of this campaign were discussed in Part I. Part II focuses on the study of the 14 September photochemical smog event associated with a sea-breeze circulation. The objective of the study is to identify and to understand better the nonlinear processes that produce high ozone concentrations. In particular, the effect of land and sea breezes is investigated by isolating the effect of nighttime and daytime emissions on ozone concentrations. The same principle then is used to isolate the effect on ozone concentrations of the two main sources of emissions in the greater Athens area: the industrial area around Elefsis and the Athens urban area. Last, the buildup of ozone from one day to another is investigated.From this study, it comes out that ozone production in the Athens area is mainly a 1-day phenomenon. The increased values of photochemical pollutant (up to 130 ppb at ground level) reached during summertime late afternoons on mountain slopes to the north and northeast of the city are related mainly to the current-day emissions. Nevertheless, the recirculation of old pollutants can have an important effect on ozone concentrations in downtown Athens, the southern part of the peninsula, and over the sea, especially near Aigina Island.

  6. EPA`s plan for part 75 continuous emissions monitoring rule revisions

    SciTech Connect

    Macedonia, J.; Vollaro, R.; Culligan, K.; Sheppard, M.

    1997-12-31

    As a result of on-going internal and external assessment of the Acid Rain Program monitoring and reporting requirements, EPA, state environmental agencies, and utilities have identified areas of the Part 75 CEM regulations which would benefit from revision or clarification. Many of the suggested revisions will add increased flexibility to the utility industry in implementing and complying with the requirements of Part 75. Other revisions will clarify existing provisions in an effort to make the regulation more understandable. Still other revisions will provide increased quality assurance of the Acid Rain Program CEM data. The panel will present EPA`s current plans for a proposed rulemaking to incorporate the technical revisions to Part 75. The panel will briefly discuss EPA`s proposed revisions to some of the major issues and will respond to questions.

  7. Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy - Part 2: Wind propagation and emission fluxes

    NASA Astrophysics Data System (ADS)

    Krueger, A.; Stremme, W.; Harig, R.; Grutter, M.

    2012-07-01

    The technique for measuring two-dimensional (2-D) plumes of volcanic gases with thermal emission spectroscopy was described in Part 1 by Stremme et al. (2012). In that paper the instrumental aspects as well as retrieval strategies for obtaining the slant column images of SO2 and SiF4, as well as animations of particular events observed at the Popocatépetl volcano, were presented. This work focuses on the procedures for determining the propagation speed of the gases and estimating an emission flux from the given image sequences. A 2-D column density distribution of a volcanic gas, available as time-consecutive frames, provides information of a wind-field and the average velocity at which the volcanic plume is propagating. The presented reconstruction method solves the equation of continuity as an ill-posed problem using mainly a Tikhonov-like regularization. It is observed from the available data sets that if the main direction of propagation is perpendicular to the line-of-sight, the algorithm works well for SO2 which has the strongest signals, and also for SiF4 in some favourable cases. Due to the similarity of the algorithm used here with the reconstruction methods used for profile retrievals based on optimal estimation theory, diagnostic tools like the averaging kernels can be calculated analogously and the information can be quantified as degrees of freedom. Thus, it is shown that the combination of wind-field and column distribution of the gas plume can provide the emission flux of the volcano both during day and night.

  8. 40 CFR Appendix B to Part 72 - Methodology for Conversion of Emissions Limits

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... expressed in pounds of SO2 per million British Thermal Unit of heat input (lb/mmBtu). The factor for...). Limits expressed as percentage of sulfur or parts per million (ppm) depend on the energy content of the fuel and thus may vary, depending on several factors such as fuel heat content and...

  9. 40 CFR Appendix P to Part 51 - Minimum Emission Monitoring Requirements

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... must include in order to be approved under the provisions of 40 CFR 51.165(b). These requirements... respective monitoring requirements are listed below. 1.1.1 Fossil fuel-fired steam generators, as specified... is: 1.2.1 Subject to a new source performance standard promulgated in 40 CFR part 60 pursuant...

  10. 40 CFR Appendix P to Part 51 - Minimum Emission Monitoring Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... must include in order to be approved under the provisions of 40 CFR 51.165(b). These requirements... respective monitoring requirements are listed below. 1.1.1 Fossil fuel-fired steam generators, as specified... is: 1.2.1 Subject to a new source performance standard promulgated in 40 CFR part 60 pursuant...

  11. The far-ultraviolet main auroral emission at Jupiter - Part 1: Dawn-dusk brightness asymmetries

    NASA Astrophysics Data System (ADS)

    Bonfond, B.; Gustin, J.; Gérard, J.-C.; Grodent, D.; Radioti, A.; Palmaerts, B.; Badman, S. V.; Khurana, K. K.; Tao, C.

    2015-10-01

    The main auroral emission at Jupiter generally appears as a quasi-closed curtain centered around the magnetic pole. This auroral feature, which accounts for approximately half of the total power emitted by the aurorae in the ultraviolet range, is related to corotation enforcement currents in the middle magnetosphere. Early models for these currents assumed axisymmetry, but significant local time variability is obvious on any image of the Jovian aurorae. Here we use far-UV images from the Hubble Space Telescope to further characterize these variations on a statistical basis. We show that the dusk side sector is ~ 3 times brighter than the dawn side in the southern hemisphere and ~ 1.1 brighter in the northern hemisphere, where the magnetic anomaly complicates the interpretation of the measurements. We suggest that such an asymmetry between the dawn and the dusk sectors could be the result of a partial ring current in the nightside magnetosphere.

  12. The sum of the parts: can we really reduce carbon emissions through individual behaviour change?

    PubMed

    Reynolds, Lucy

    2010-01-01

    Individuals are increasingly being urged to 'do their bit' in the fight against climate change, with governments and pro-environmentalists insisting that the collective impact of small behaviour changes will result in a meaningful reduction in global carbon emissions. The following paper considers this debate, as well as offering personal contributions from two leading environmentalists: Dr Doug McKenzie-Mohr, environmental psychologist and author of Fostering Sustainable Behavior: Community-Based Social Marketing; and Dr Tom Crompton, change strategist for WWF and co-author of Meeting Environmental Challenges: The Role of Human Identity, who argues for the role of intrinsic value systems in achieving sustainable behaviour change. As well as considering the responsibility of the individual in mitigating climate change, the paper introduces the discipline of social marketing as an effective tool for facilitating individual behaviour change, drawing on evidence from the field to recommend the key characteristics of effective behaviour change programmes. PMID:20333949

  13. Transcontinental methane measurements: Part 2. Mobile surface investigation of fossil fuel industrial fugitive emissions

    NASA Astrophysics Data System (ADS)

    Leifer, Ira; Culling, Daniel; Schneising, Oliver; Farrell, Paige; Buchwitz, Michael; Burrows, John P.

    2013-08-01

    The potent greenhouse gas, methane, CH4, has a wide variety of anthropogenic and natural sources. Fall, continental-scale (Florida to California) surface CH4 data were collected to investigate the importance of fossil fuel industrial (FFI) emissions in the South US. A total of 6600 measurements along 7020-km of roadways were made by flame ion detection gas chromatography onboard a nearly continuously moving recreational vehicle in 2010. A second, winter survey in Southern California measured CH4 at 2 Hz with a cavity ring-down spectrometer in 2012. Data revealed strong and persistent FFI CH4 sources associated with refining, oil/gas production, a presumed major pipeline leak, and a coal loading plant. Nocturnal CH4 mixing ratios tended to be higher than daytime values for similar sources, sometimes significantly, which was attributed to day/night meteorological differences, primarily changes in the boundary layer height. The highest CH4 mixing ratio (39 ppm) was observed near the Kern River Oil Field, California, which uses steam reinjection. FFI CH4 plume signatures were distinguished as stronger than other sources on local scales. On large (4°) scales, the CH4 trend was better matched spatially with FFI activity than wetland spatial patterns. Qualitative comparison of surface data with SCIAMACHY and GOSAT satellite retrievals showed agreement of the large-scale CH4 spatial patterns. Comparison with inventory models and seasonal winds suggests for some seasons and some portions of the Gulf of Mexico a non-negligible underestimation of FFI emissions. For other seasons and locations, qualitative interpretation is not feasible. Unambiguous quantitative source attribution is more complex, requiring transport modeling.

  14. Acoustic monitoring of gas emissions from the seafloor. Part I: quantifying the volumetric flow of bubbles

    NASA Astrophysics Data System (ADS)

    Leblond, Isabelle; Scalabrin, Carla; Berger, Laurent

    2014-09-01

    Three decades of continuous ocean exploration have led us to identify subsurface fluid related processes as a key phenomenon in marine earth science research. The number of seep areas located on the seafloor has been constantly increasing with the use of multi-scale imagery techniques. Due to recent advances in transducer technology and computer processing, multibeam echosounders are now commonly used to detect submarine gas seeps escaping from the seafloor into the water column. A growing number of en- route surveys shows that sites of gas emissions escaping from the seafloor are much more numerous than previously thought. Estimating the temporal variability of the gas flow rate and volumes escaping from the seafloor has thus become a challenge of relevant interest which could be addressed by sea-floor continuous acoustic monitoring. Here, we investigate the feasibility of estimating the volumetric flow rates of gas emissions from horizontal backscattered acoustic signals. Different models based on the acoustic backscattering theory of bubbles are presented. The forward volume backscattering strength and the inversion volumetric flow rate solutions were validated with acoustic measurements from artificial gas flow rates generated in controlled sea-water tank experiments. A sensitivity analysis was carried out to investigate the behavior of the 120-kHz forward solution with respect to model input parameters (horizontal distance between transducer and bubble stream, bubble size distribution and ascent rate). The most sensitive parameter was found to be the distance of the bubble stream which can affect the volume backscattering strength by 20 dB within the horizontal range of 0-200 m. Results were used to derive the detection probability of a bubble stream for a given volume backscattering strength threshold according to different bubble flow rates and horizontal distance.

  15. 40 CFR 1060.705 - How do I certify components to an emission level other than the standard under this part or use...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false How do I certify components to an emission level other than the standard under this part or use such components in my equipment? 1060.705 Section 1060.705 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS...

  16. 40 CFR 1060.705 - How do I certify components to an emission level other than the standard under this part or use...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false How do I certify components to an emission level other than the standard under this part or use such components in my equipment? 1060.705 Section 1060.705 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS...

  17. Air emission into a water shear layer through porous media. Part 2: Cavitation induced pressure attenuation

    SciTech Connect

    Myer, E.C.; Marboe, R.C.

    1994-12-31

    Cavitation near the casing of a hydroturbine can lead to damage through both cavitation erosion and mechanical vibration of the casing and the associated piping. Cavitation erosion results from the collapse of cavitation bubbles on or near a surface such as the casing wall. Mechanical vibrations transmitted to the casing directly through the collapse of bubbles on the casing wall indirectly through a coupling of the acoustic pressure pulse due to a nearby collapse on the turbine blade. Air emission along the casing can reduce the intensity of the tip vortex and the gap cavitation through ventilation of the cavity. Reduction in the machinery vibration is obtained by reduction of the intensity of cavitation bubble collapse and attenuation and scattering of the radiated acoustic pressure. This requires a bubble layer which may be introduced in the vicinity of the turbine blade tips. This layer remains for some distance downstream of the blades and is effective for attenuation of tip vortex induced noise and blade surface cavitation noise. For the purpose of characterizing this bubble layer within a water pipe, the authors spanned a pipe with a two dimensional hydrofoil and emitted air through porous media (20 and 100 micron porosity sintered stainless steel) into the shear flow over the hydrofoil. This paper is limited to an investigation of the attenuation of acoustic pressure propagating to the casing rather than the reduction in acoustic source level due to collapse cushioning effects.

  18. C-Coupon Studies of SiC/SiC Composites. Part 1; Acoustic Emission Monitoring

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Hurwitz, Frances I.; Calomino, Anthony M.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Modal acoustic emission (AE) was used to monitor the acoustic activity during room temperature and elevated temperature c-coupon tests for a variety of SiC/SiC systems including composites containing Sylramic (trademark), ZMI (trademark), or Hi-Nicalon (trademark) fibers with melt-infiltrated or polymer-infiltrated SiC matrices. Modal AE proved excellent at monitoring matrix cracking in the curved portion of the C-coupon specimen with increasing load. This included the load at which the first AE event occurred and the location of AE events during the test that were, presumably, caused by the formation and growth of interlaminar cracks and, at higher loads, transverse cracks. Graphical techniques were employed to estimate the load for first AE. It was determined that for this test with these material systems, the first AE could be estimated within the load range bounded by the load at which initial deviation from linearity of the load-displacement curve occurs and the load where the 98% offset of the linear regression fit intercepted the load-displacement curve. The calculation of interlaminar tensile (ILT) stress from the load for first AE was determined for all the systems. Ultimate ILT strength usually corresponded to ILT stress determined from the ultimate load to failure of the C-coupon test, which was considerably higher than the first cracking stress.

  19. Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes -- Update to Include Analyses of an Economizer Option and Alternative Winter Water Heating Control Option

    SciTech Connect

    Baxter, Van D

    2006-12-01

    . Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft{sup 2} houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment, ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. In 2006, the two top-ranked options from the 2005 study, air-source and ground-source versions of an integrated heat pump (IHP) system, were subjected to an initial business case study. The IHPs were subjected to a more rigorous hourly-based assessment of their performance potential compared to a baseline suite of equipment of legally minimum efficiency that provided the same heating, cooling, water heating, demand dehumidification, and ventilation services as the IHPs. Results were summarized in a project report, Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes, ORNL/TM-2006/130 (Baxter 2006). The present report is an update to that document. Its primary purpose is to summarize results of an analysis of the potential of adding an outdoor air economizer operating mode to the IHPs to take advantage of free cooling (using outdoor air to cool the house) whenever possible. In addition it

  20. Vehicle-based road dust emission measurement—Part II: Effect of precipitation, wintertime road sanding, and street sweepers on inferred PM 10 emission potentials from paved and unpaved roads

    NASA Astrophysics Data System (ADS)

    Kuhns, H.; Etyemezian, V.; Green, M.; Hendrickson, Karin; McGown, Michael; Barton, Kevin; Pitchford, Marc

    Testing Re-Entrained Kinetic Emissions from Roads (TRAKER) is a new technique to infer paved and unpaved road dust PM 10 emission potentials based on particulate matter (PM) measurements made onboard a moving vehicle. Light scattering instruments mounted in front and behind the vehicle's tires measure the differential particle concentration of dust suspended by the vehicle's tire in contact with the road surface. Through empirical regressions relating the differential concentration (i.e. TRAKER signal) with the vehicle speed and the downwind flux of PM 10 particles from the road, an equation is derived to infer the speed independent road dust emission potential from the measured TRAKER signal. Measurements from TRAKER offer a new perspective on the processes that affect road dust emissions. The system was used to investigate temporal changes in emission potentials from paved roads in both the winter and summer in the Treasure Valley in Southwest Idaho. During the 3-week wintertime sampling period, the residential road dust PM 10 emission potential decreased by ˜50%. Summertime PM 10 emission potentials were similar to those observed at the end of the winter sampling and showed no upward or downward trends. Wintertime unpaved road emissions increased consistently with the number of days since the last rainfall. Measurement of road dust emission potentials after road sanding on dry roads indicated a 75% increase in PM 10 emissions after 2.5 h. This effect was short lived and emission potentials returned to their pre-sanding levels within 8 h of the sand application. Street sweeping with mechanical and vacuum sweepers was found to offer no measurable reduction in PM 10 emission potentials. On several roads, the PM 10 emission potentials actually increased immediately after vacuum sweeping. Long term effects of street sweeping on road dust emissions were not evaluated as part of this study and may offer some overall reduction in PM emissions from paved roads.

  1. Environmental assessment of three egg production systems--Part II. Ammonia, greenhouse gas, and particulate matter emissions.

    PubMed

    Shepherd, T A; Zhao, Y; Li, H; Stinn, J P; Hayes, M D; Xin, H

    2015-03-01

    As an integral part of the Coalition for Sustainable Egg Supply (CSES) Project, this study simultaneously monitored air emissions of 3 commercially operated egg production systems at the house level and associated manure storage over 2 single-cycle flocks (18 to 78 wk of age). The 3 housing systems were 1) a conventional cage house (CC) with a 200,000-hen capacity (6 hens in a cage at a stocking density of 516 cm2/hen), 2) an enriched colony house (EC) with a 50,000-hen capacity (60 hens per colony at a stocking density of 752 cm2/hen), and 3) an aviary house (AV) with a 50,000-hen capacity (at a stocking density of 1253 to 1257 cm2/hen). The 3 hen houses were located on the same farm and were populated with Lohmann white hens of the same age. Indoor environment and house-level gaseous (ammonia [NH3] and greenhouse gasses [GHG], including carbon dioxide [CO2], methane [CH4], and nitrous oxide [N2O]) and particulate matter (PM10, PM2.5) emissions were monitored continually. Gaseous emissions from the respective manure storage of each housing system were also monitored. Emission rates (ERs) are expressed as emission quantities per hen, per animal unit (AU, 500 kg live BW), and per kilogram of egg output. House-level NH3 ER (g/hen/d) of EC (0.054) was significantly lower than that of CC (0.082) or AV (0.112) (P<0.05). The house-level CO2 ER (g/hen/d) was lower for CC (68.3) than for EC and AV (74.4 and 74.0, respectively), and the CH4 ER (g/hen/d) was similar for all 3 houses (0.07 to 0.08). The house-level PM ER (mg/hen/d), essentially representing the farm-level PM ER, was significantly higher for AV (PM10 100.3 and PM2.5 8.8) than for CC (PM10 15.7 and PM2.5 0.9) or EC (PM10 15.6 and PM2.5 1.7) (P<0.05). The farm-level (house plus manure storage) NH3 ER (g/hen/d) was significantly lower for EC (0.16) than for CC (0.29) or AV (0.30) (P<0.05). As expected, the magnitudes of GHG emissions were rather small for all 3 production systems. Data from this study enable

  2. Environmental assessment of three egg production systems — Part II. Ammonia, greenhouse gas, and particulate matter emissions

    PubMed Central

    Shepherd, T. A.; Zhao, Y.; Li, H.; Stinn, J. P.; Hayes, M. D.; Xin, H.

    2015-01-01

    As an integral part of the Coalition for Sustainable Egg Supply (CSES) Project, this study simultaneously monitored air emissions of 3 commercially operated egg production systems at the house level and associated manure storage over 2 single-cycle flocks (18 to 78 wk of age). The 3 housing systems were 1) a conventional cage house (CC) with a 200,000-hen capacity (6 hens in a cage at a stocking density of 516 cm2/hen), 2) an enriched colony house (EC) with a 50,000-hen capacity (60 hens per colony at a stocking density of 752 cm2/hen), and 3) an aviary house (AV) with a 50,000-hen capacity (at a stocking density of 1253 to 1257 cm2/hen). The 3 hen houses were located on the same farm and were populated with Lohmann white hens of the same age. Indoor environment and house-level gaseous (ammonia [NH3] and greenhouse gasses [GHG], including carbon dioxide [CO2], methane [CH4], and nitrous oxide [N2O]) and particulate matter (PM10, PM2.5) emissions were monitored continually. Gaseous emissions from the respective manure storage of each housing system were also monitored. Emission rates (ERs) are expressed as emission quantities per hen, per animal unit (AU, 500 kg live BW), and per kilogram of egg output. House-level NH3 ER (g/hen/d) of EC (0.054) was significantly lower than that of CC (0.082) or AV (0.112) (P < 0.05). The house-level CO2 ER (g/hen/d) was lower for CC (68.3) than for EC and AV (74.4 and 74.0, respectively), and the CH4 ER (g/hen/d) was similar for all 3 houses (0.07 to 0.08). The house-level PM ER (mg/hen/d), essentially representing the farm-level PM ER, was significantly higher for AV (PM10 100.3 and PM2.5 8.8) than for CC (PM10 15.7 and PM2.5 0.9) or EC (PM10 15.6 and PM2.5 1.7) (P < 0.05). The farm-level (house plus manure storage) NH3 ER (g/hen/d) was significantly lower for EC (0.16) than for CC (0.29) or AV (0.30) (P < 0.05). As expected, the magnitudes of GHG emissions were rather small for all 3 production systems. Data from this study

  3. Air pollution and early deaths in the United States. Part II: Attribution of PM2.5 exposure to emissions species, time, location and sector

    NASA Astrophysics Data System (ADS)

    Dedoussi, Irene C.; Barrett, Steven R. H.

    2014-12-01

    Combustion emissions constitute the largest source of anthropogenic emissions in the US, and lead to the degradation of air quality and human health. In Part I we computed the population fine particulate matter (PM2.5) exposure and number of early deaths caused by emissions from six major sectors: electric power generation, industry, commercial and residential activities, road transportation, marine transportation and rail transportation. In Part II we attribute exposure and early deaths to sectors, emissions species, time of emission, and location of emission. We apply a long-term adjoint sensitivity analysis and calculate the four dimensional sensitivities (time and space) of PM2.5 exposure with respect to each emissions species. Epidemiological evidence is used to relate increased population exposure to premature mortalities. This is the first regional application of the adjoint sensitivity analysis method to characterize long-term air pollution exposure. (A global scale application has been undertaken related to intercontinental pollution.) We find that for the electric power generation sector 75% of the attributable PM2.5 exposure is due to SO2 emissions, and 80% of the annual impacts are attributed to emissions from April to September. In the road transportation sector, 29% of PM2.5 exposure is due to NOx emissions and 33% is from ammonia (NH3), which is a result of emissions after-treatment technologies. We estimate that the benefit of reducing NH3 emissions from road transportation is ∼20 times that of NOx per unit mass. 75% of the road transportation ammonia impacts occur during the months October to March. We publicly release the sensitivity matrices computed, noting their potential use as a rapid air quality policy assessment tool.

  4. Exposure and Emissions Monitoring during Carbon Nanofiber Production—Part I: Elemental Carbon and Iron–Soot Aerosols

    PubMed Central

    Birch, M. Eileen; Ku, Bon-Ki; Evans, Douglas E.; Ruda-Eberenz, Toni A.

    2015-01-01

    Production of carbon nanofibers and nanotubes (CNFs/CNTs) and their composite products is increasing globally. High volume production may increase the exposure risks for workers who handle these materials. Though health effects data for CNFs/CNTs are limited, some studies raise serious health concerns. Given the uncertainty about their potential hazards, there is an immediate need for toxicity data and field studies to assess exposure to CNFs/CNTs. An extensive study was conducted at a facility that manufactures and processes CNFs. Filter, sorbent, cascade impactor, bulk, and microscopy samples, combined with direct-reading instruments, provided complementary information on air contaminants. Samples were analyzed for organic carbon (OC) and elemental carbon (EC), metals, and polycyclic aromatic hydrocarbons (PAHs), with EC as a measure of CNFs. Transmission electron microscopy with energy-dispersive X-ray spectroscopy also was applied. Fine/ultrafine iron-rich soot, PAHs, and carbon monoxide were production byproducts. Direct-reading instrument results were reported previously [Evans DE et al. (Aerosol monitoring during carbon nanofiber production: mobile direct-reading sampling. Ann Occup Hyg 2010;54:514–31.)] Results for time-integrated samples are reported as companion papers in this Issue. OC and EC, metals, and microscopy results are reported here, in Part I, while results for PAHs are reported in Part II [Birch ME. (Exposure and Emissions Monitoring during Carbon Nanofiber Production—Part II: Polycyclic Aromatic Hydrocarbons. Ann. Occup. Hyg 2011; 55: 1037–47.)]. Respirable EC area concentrations inside the facility were about 6–68 times higher than outdoors, while personal breathing zone samples were up to 170 times higher. PMID:21965464

  5. 40 CFR Appendix Xvi to Part 86 - Pollutant Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Pollutant Mass Emissions Calculation... Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles Equipped With...-Fueled Vehicle Pollutant Mass Emission Calculation Procedure. (1) For all TLEVs, LEVs, and ULEVs,...

  6. 40 CFR Appendix Xvi to Part 86 - Pollutant Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Pollutant Mass Emissions Calculation... Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles Equipped With...-Fueled Vehicle Pollutant Mass Emission Calculation Procedure. (1) For all TLEVs, LEVs, and ULEVs,...

  7. Odor and odorous chemical emissions from animal buildings: part 1 - project overview, collection methods, and quality control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. 40 CFR Appendix Xvi to Part 86 - Pollutant Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Where: Ywm = Weighted mass emissions of each pollutant, i.e., HC, CO, NOX or CO , in grams per vehicle mile. Yct = Mass emissions as calculated from the “transient” phase of the cold start test, in grams... grams per test phase. Ys = Mass emissions as calculated from the “stabilized” phase of the cold...

  9. 40 CFR Appendix Xvi to Part 86 - Pollutant Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Where: Ywm = Weighted mass emissions of each pollutant, i.e., HC, CO, NOX or CO , in grams per vehicle mile. Yct = Mass emissions as calculated from the “transient” phase of the cold start test, in grams... grams per test phase. Ys = Mass emissions as calculated from the “stabilized” phase of the cold...

  10. Global emission inventories for C4-C14 perfluoroalkyl carboxylic acid (PFCA) homologues from 1951 to 2030, Part I: production and emissions from quantifiable sources.

    PubMed

    Wang, Zhanyun; Cousins, Ian T; Scheringer, Martin; Buck, Robert C; Hungerbühler, Konrad

    2014-09-01

    We quantify global emissions of C4-C14 perfluoroalkyl carboxylic acid (PFCA) homologues during the life-cycle of products based on perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorooctane sulfonyl fluoride (POSF), and fluorotelomer compounds. We estimate emissions of 2610-21400 tonnes of C4-C14 PFCAs in the period from 1951 to 2015, and project 20-6420 tonnes to be emitted from 2016 to 2030. The global annual emissions steadily increased in the period 1951-2002, followed by a decrease and then another increase in the period 2002-2012. Releases from fluoropolymer production contributed most to historical PFCA emissions (e.g. 55-83% in 1951-2002). Since 2002, there has been a geographical shift of industrial sources (particularly fluoropolymer production sites) from North America, Europe and Japan to emerging Asian economies, especially China. Sources differ between PFCA homologues, sometimes considerably, and the relative contributions of each source change over time. For example, whereas 98-100% of historical (1951-2002) PFOA emissions are attributed to direct releases during the life-cycle of products containing PFOA as ingredients or impurities, a much higher historical contribution from PFCA precursor degradation is estimated for some other homologues (e.g. 9-78% for PFDA). We address the uncertainties of the PFCA emissions by defining a lower and a higher emission scenario, which differ by approximately a factor of eight. PMID:24932785

  11. Nanoparticle emission assessment technique (NEAT) for the identification and measurement of potential inhalation exposure to engineered nanomaterials--part A.

    PubMed

    Methner, M; Hodson, L; Geraci, C

    2010-03-01

    There are currently no exposure limits specific to engineered nanomaterial nor any national or international consensus standards on measurement techniques for nanomaterials in the workplace. However, facilities engaged in the production and use of engineered nanomaterials have expressed an interest in learning whether the potential for worker exposure exists. To assist with answering this question, the National Institute for Occupational Safety and Health established a nanotechnology field research team whose primary goal was to visit facilities and evaluate the potential for release of nanomaterials and worker exposure. The team identified numerous techniques to measure airborne nanomaterials with respect to particle size, mass, surface area, number concentration, and composition. However, some of these techniques lack specificity and field portability and are difficult to use and expensive when applied to routine exposure assessment. This article describes the nanoparticle emission assessment technique (NEAT) that uses a combination of measurement techniques and instruments to assess potential inhalation exposures in facilities that handle or produce engineered nanomaterials. The NEAT utilizes portable direct-reading instrumentation supplemented by a pair of filter-based air samples (source-specific and personal breathing zone). The use of the filter-based samples are crucial for identification purposes because particle counters are generally insensitive to particle source or composition and make it difficult to differentiate between incidental and process-related nanomaterials using number concentration alone. Results from using the NEAT at 12 facilities are presented in the companion article (Part B) in this issue. PMID:20017054

  12. A Preliminary Investigation into the Mitigation of Plug-in Hybrid Electric Vehicle Tailpipe Emissions Through Supervisory Control Methods Part 2: Experimental Evaluation of Emissions Reduction Methodologies

    SciTech Connect

    Smith, David E; Lohse-Busch, Henning; Irick, David Kim

    2010-04-01

    Plug-in hybrid electric vehicle (PHEV) technologies have the potential for considerable petroleum consumption reductions, possibly at the expense of increased tailpipe emissions due to multiple 'cold' start events and improper use of the engine for PHEV specific operation. PHEVs operate predominantly as electric vehicles (EVs) with intermittent assist from the engine during high power demands. As a consequence, the engine can be subjected to multiple cold start events. These cold start events may have a significant impact on the tailpipe emissions due to degraded catalyst performance and starting the engine under less than ideal conditions. On current hybrid electric vehicles (HEVs), the first cold start of the engine dictates whether or not the vehicle will pass federal emissions tests. PHEV operation compounds this problem due to infrequent, multiple engine cold starts. A continuation of previous analytical work, this research, experimentally verifies a vehicle supervisory control system for a pre-transmission parallel PHEV powertrain architecture. Energy management strategies are evaluated and implemented in a virtual environment for preliminary assessment of petroleum displacement benefits and rudimentary drivability issues. This baseline vehicle supervisory control strategy, developed as a result of this assessment, is implemented and tested on actual hardware in a controlled laboratory environment over a baseline test cycle. Engine cold start events are aggressively addressed in the development of this control system, which leads to enhanced pre-warming and energy-based engine warming algorithms that provide substantial reductions in tailpipe emissions over the baseline supervisory control strategy. The flexibility of the PHEV powertrain allows for decreased emissions during any engine starting event through powertrain 'torque shaping' algorithms. The results of the research show that PHEVs do have the potential for substantial reductions in fuel consumption

  13. Emissions Inventory Report Summary: Reporting Requirements for the New Mexico Administrative code, Title 20, Chapter 2, Part 73 (20 NMAC 2.73) for Calendar Year 1997

    SciTech Connect

    1999-01-01

    Los Alamos National Laboratory (the Laboratory) is subject to emissions reporting requirements for regulated air contaminants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73, (20 NMAC 2.73), Notice of Intent and Emissions Inventory Requirements. The Laboratory has the potential to emit 100 tons per year of suspended particulate matter (PM), nitrogen oxides (NO{sub x}), carbon monoxide (CO), and volatile organic compounds (VOCs). For 1997, combustion products from the industrial sources contributed the greatest amount of regulated air emissions from the Laboratory. Research and development activities contributed the greatest amount of VOCs. Emissions of beryllium and aluminum were reported for activities permitted under 20 NMAC 2.72, Construction Permits.

  14. Emissions Inventory Report Summary: Reporting Requirements for the New Mexico Administrative Code, Title 20, Chapter 2, Part 73 (20 NMAC 2.73) for Calendar Year 2001

    SciTech Connect

    Margorie Stockton

    2003-04-01

    Los Alamos National Laboratory is subject to annual emissions-reporting requirements for regulated air contaminants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73 (20.2.73 NMAC), Notice of Intent and Emissions Inventory Requirements. The applicability of the requirements is based on the Laboratory's potential to emit 100 tons per year of suspended particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, or volatile organic compounds. For calendar year 2001, the Technical Area 3 steam plant was the primary source of criteria air pollutants from the Laboratory, while research and development activities were the primary source of volatile organic compounds. Emissions of beryllium and aluminum were reported for activities permitted under 20.2.72 NMAC. Hazardous air pollutant emissions from chemical use for research and development activities were also reported.

  15. 40 CFR Appendix E to Part 75 - Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units E Appendix E to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS...

  16. Characterization of helium/argon working gas systems in a radiofrequency glow discharge atomic emission source. Part I: Optical emission, sputtering and electrical characteristics

    NASA Astrophysics Data System (ADS)

    Christopher, Steven J.; Hartenstein, Matthew L.; Marcus, R. Kenneth; Belkin, Mikhail; Caruso, Joseph A.

    1998-08-01

    Studies are performed to determine the influence of discharge gas composition (helium/argon working gas mixtures) on the analyte emission signal intensities, sputtering rates, and DC-bias characteristics of an analytical radiofrequency glow discharge atomic emission spectroscopy (RF-GD-AES) source. As the partial pressure of He is increased from 0 to 15 torr, increased emission intensity is observed for a range of bulk and trace elements in NIST 1250 SRM (low alloy steel), regardless of the base pressure of Ar in the source (5 and 9 torr). In contrast to increases in analyte emission intensity of up to 300%, counterindicative decreases in the sputtering rates on the order of about 30-50% are observed. The magnitude of these effects depends on both the partial pressure of helium introduced to the source and the total pressure of the He and Ar gases. Use of relative emission yield (REY) to normalize changes in emission intensity to sputtering rates indicates that excitation efficiencies increase under these conditions. Increases in average electron energy and temperature appear to control this response. Decreases in both analyte emission intensities and sputter rates occur with increasing He partial pressure when the total pressure in the cell remains fixed (11 torr in these studies). Emission yields for the fixed pressure, mixed gas plasmas decrease as the partial pressure of He (He/Ar ratio) in the RF-GD source increases. In this case, decreases in electron number densities appear to dictate the lower REYs. Measurement of DC-bias values at the sample surface provide understanding with respect to the observed changes in sputtering rates as well as suggest the origins of changes in plasma electron energetics. Use of a diamond stylus profilometer provides both the quantitative sputter rate information as well as qualitative insights into the use of mixed gas plasmas for enhanced depth profiling capabilities. The analyte emission characteristics of these mixed gas

  17. 40 CFR Appendix D to Part 52 - Determination of Sulfur Dioxide Emissions From Stationary Sources by Continuous Monitors

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... emission standard. 6. Calibration Drift (24-hours) a ≤5 percent of emission standard. 7. Response Time ≤5... system without operator intervention or initiation are allowable at any time. During the entire 168-hour... adjustment at 24-hour intervals in the example sheet shown in Figure D-5. 5.3Field Test for Response Time....

  18. 40 CFR Table W - 7 of Subpart W of Part 98-Default Methane Emission Factors for Natural Gas Distribution

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 0.772 Open-ended Line 26.131 Population Emission Factors—Below Grade Metering-Regulating station 1..., Inlet Pressure 100 to 300 psig 0.20 Below Grade M&R Station, Inlet Pressure Population....13 Cast Iron 27.25 Population Emission Factors—Distribution Services, Gas Service 4 Unprotected...

  19. 40 CFR Table W - 7 of Subpart W of Part 98-Default Methane Emission Factors for Natural Gas Distribution

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 0.772 Open-ended Line 26.131 Population Emission Factors—Below Grade Metering-Regulating station 1..., Inlet Pressure 100 to 300 psig 0.20 Below Grade M&R Station, Inlet Pressure Population....13 Cast Iron 27.25 Population Emission Factors—Distribution Services, Gas Service 4 Unprotected...

  20. US Department of Energy radionuclide air emissions annual report (under Subpart H of 40 CFR Part 61) calendar year 1993

    SciTech Connect

    Not Available

    1993-12-31

    This report contains information collected by the Rocky Flats Plant concerning the emission of radionuclides into the air. Topics discussed include: Facility information, source description, air emissions data, dose assessments, point and non-point sources, and supplemental information on decontamination of concrete docks.

  1. VOLATILE ORGANIC COMPOUND EMISSIONS FROM LATEX PAINT-PART 2. TEST HOUSE STUDIES AND INDOOR AIR QUALITY (IAQ) MODELING

    EPA Science Inventory

    Emission models developed using small chamber data were combined with an Indoor Air Quality (IAQ) model to analyze the impact of volatile organic compound (VOC) emissions from latex paint on indoor environments. Test house experiments were conducted to verify the IAQ model's pred...

  2. Improving and Assessing Aircraft-based Greenhouse Gas Emission Rate Measurements at Indianapolis as part of the INFLUX project.

    NASA Astrophysics Data System (ADS)

    Heimburger, A. M. F.; Shepson, P. B.; Stirm, B. H.; Susdorf, C.; Cambaliza, M. O. L.

    2015-12-01

    Since the Copenhagen accord in 2009, several countries have affirmed their commitment to reduce their greenhouse gas emissions. The United States and Canada committed to reduce their emissions by 17% below 2005 levels, by 2020, Europe by 14% and China by ~40%. To achieve such targets, coherent and effective strategies in mitigating atmospheric carbon emissions must be implemented in the next decades. Whether such goals are actually achieved, they require that reductions are "measurable", "reportable", and "verifiable". Management of greenhouse gas emissions must focus on urban environments since ~74% of CO2 emissions worldwide will be from cities, while measurement approaches are highly uncertain (~50% to >100%). The Indianapolis Flux Experiment (INFLUX) was established to develop, assess and improve top-down and bottom-up quantifications of urban greenhouse gas emissions. Based on an aircraft mass balance approach, we performed a series of experiments focused on the improvement of CO2, CH4 and CO emission rates quantification from Indianapolis, our final objective being to drastically improve the method overall uncertainty from the previous estimate of 50%. In November-December 2014, we conducted nine methodologically identical mass balance experiments in a short period of time (24 days, one downwind distance) for assumed constant total emission rate conditions, as a means to obtain an improved standard deviation of the mean determination. By averaging the individual emission rate determinations, we were able to obtain a method precision of 17% and 16% for CO2 and CO, respectively, at the 95%C.L. CH4 emission rates are highly variable day to day, leading to precision of 60%. Our results show that repetitive sampling can enable improvement in precision of the aircraft top-down methods through averaging.

  3. TransCom N2O model inter-comparison - Part 2: Atmospheric inversion estimates of N2O emissions

    NASA Astrophysics Data System (ADS)

    Thompson, R. L.; Ishijima, K.; Saikawa, E.; Corazza, M.; Karstens, U.; Patra, P. K.; Bergamaschi, P.; Chevallier, F.; Dlugokencky, E.; Prinn, R. G.; Weiss, R. F.; O'Doherty, S.; Fraser, P. J.; Steele, L. P.; Krummel, P. B.; Vermeulen, A.; Tohjima, Y.; Jordan, A.; Haszpra, L.; Steinbacher, M.; Van der Laan, S.; Aalto, T.; Meinhardt, F.; Popa, M. E.; Moncrieff, J.; Bousquet, P.

    2014-06-01

    This study examines N2O emission estimates from five different atmospheric inversion frameworks based on chemistry transport models (CTMs). The five frameworks differ in the choice of CTM, meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation data set. The posterior modelled atmospheric N2O mole fractions are compared to observations to assess the performance of the inversions and to help diagnose problems in the modelled transport. Additionally, the mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 TgN yr-1 and is consistent with previous estimates. Ocean emissions represent between 31 and 38% of the global total compared to widely varying previous estimates of 24 to 38%. Emissions from the northern mid- to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid- to high latitudes in the Northern Hemisphere; the emission ratio for 0-30° N to 30-90° N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convective mixing. Estimates of the seasonal cycle in N2O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extratropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies.

  4. TransCom N2O model inter-comparison, Part II: Atmospheric inversion estimates of N2O emissions

    NASA Astrophysics Data System (ADS)

    Thompson, R. L.; Ishijima, K.; Saikawa, E.; Corazza, M.; Karstens, U.; Patra, P. K.; Bergamaschi, P.; Chevallier, F.; Dlugokencky, E.; Prinn, R. G.; Weiss, R. F.; O'Doherty, S.; Fraser, P. J.; Steele, L. P.; Krummel, P. B.; Vermeulen, A.; Tohjima, Y.; Jordan, A.; Haszpra, L.; Steinbacher, M.; Van der Laan, S.; Aalto, T.; Meinhardt, F.; Popa, M. E.; Moncrieff, J.; Bousquet, P.

    2014-02-01

    This study examines N2O emission estimates from 5 different atmospheric inversion frameworks. The 5 frameworks differ in the choice of atmospheric transport model, meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation dataset. The mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 Tg N yr-1 and is consistent with previous estimates. Ocean emissions represent between 31% and 38% of the global total compared to widely varying previous estimates of 24% to 38%. Emissions from the northern mid to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid to high latitudes in the Northern Hemisphere; the emission ratio for 0-30° N to 30-90° N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convection. Estimates of the seasonal cycle in N2O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extra-tropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies.

  5. The seasonal impact of blending oxygenated organics with gasoline on motor vehicle tailpipe and evaporative emissions. Part 2

    SciTech Connect

    Stump, F.D.; Knapp, K.T.; Ray, W.D.; Burton, C.; Snow, R.

    1990-01-01

    Evaporative and tailpipe emissions from a 1987 GM Corsica with adaptive learning closed loop control were measured with six fuels and four temperatures. Measured emissions were total (THC) and speciated hydrocarbons, aldehydes, ethanol, MTBE, benzene, 1,3,-butadiene, Co, and NO{sub x}. Tests were also performed to determine the effect of air conditioning (AC) and oxygen sensor failure. In general, AC reduced Highway Fuel Economy emissions, increased FTP emissions, and reduced fuel economy for both test cycles. Oxygen sensor malfunction increased tailpipe emissions and fuel economy. Higher levels of regulated tailpipe emissions were generally produced at the low test temperature. None of the fuels tested appeared to offer a consistent reduction in tailpipe THC and CO emissions under the conditions tested. This paper is the second in a series describing the effects of oxygenated fuels on the evaporative and tailpipe emissions from current technology light-duty gasoline powered motor vehicles. The study resulted from recent considerations by the United States Environmental Protection Agency (EPA) concerning the benefits of blending certain oxygenated compounds (alcohols and ethers) at specified levels with gasoline to be used as a vehicle fuel. This action was taken because these gasoline blends should provide the following benefits: Oxygenation can enhance fuel octane rating and thus compensate for the elimination of lead, and octane booster; the presence of oxygen in the field should reduce tailpipe emissions of total hydrocarbons and carbon monoxide; the addition of these oxygenated compounds will extend the present fuel supply and therefore could reduce oil imports; and surplus grain crops can be turned into ethanol, which can be used directly in fuel blends or reacted with isobutylene to form ethyl tertiary butyl ether.

  6. The impact of shipping emissions on air pollution in the greater North Sea region - Part 2: Scenarios for 2030

    NASA Astrophysics Data System (ADS)

    Matthias, V.; Aulinger, A.; Backes, A.; Bieser, J.; Geyer, B.; Quante, M.; Zeretzke, M.

    2016-01-01

    Scenarios for future shipping emissions in the North Sea have been developed in the framework of the Clean North Sea Shipping project. The effects of changing NOx and SO2 emissions were investigated with the CMAQ chemistry transport model for the year 2030 in the North Sea area. It has been found that, compared to today, the contribution of shipping to the NO2 and O3 concentrations will increase due to the expected enhanced traffic by more than 20 and 5 %, respectively, by 2030 if no regulation for further emission reductions is implemented in the North Sea area. PM2.5 will decrease slightly because the sulfur contents in ship fuels will be reduced as international regulations foresee. The effects differ largely between regions, seasons and date of the implementation of stricter regulations for NOx emissions from newly built ships.

  7. The impact of shipping emissions on air pollution in the Greater North Sea region - Part 2: Scenarios for 2030

    NASA Astrophysics Data System (ADS)

    Matthias, V.; Aulinger, A.; Backes, A.; Bieser, J.; Geyer, B.; Quante, M.; Zeretzke, M.

    2015-04-01

    Scenarios for future shipping emissions in the North Sea have been developed in the framework of the Clean North Sea Shipping project. The effects of changing NOx and SO2 emissions were invesigated with the chemistry transport model CMAQ for the year 2030 in the North Sea area. It has been found that, compared to today, the contribution of shipping to the NO2 and O3 concentrations will increase due to the expected enhanced traffic by more than 20 and 5%, respectively, by 2030 if no regulation for further emission reductions will be implemented in the North Sea area. PM2.5 will decrease slightly because the sulphur contents in ship fuels will be reduced as international regulations foresee. The effects differ largely between regions, seasons and date of the implementation of stricter regulations for NOx emissions from new built ships.

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

    PubMed

    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. PMID:26650082

  9. Fire emission heights in the climate system - Part 2: Impact on transport, black carbon concentrations and radiation

    NASA Astrophysics Data System (ADS)

    Veira, A.; Kloster, S.; Schutgens, N. A. J.; Kaiser, J. W.

    2015-07-01

    Wildfires represent a major source for aerosols impacting atmospheric radiation, atmospheric chemistry and cloud micro-physical properties. Previous case studies indicated that the height of the aerosol-radiation interaction may crucially affect atmospheric radiation, but the sensitivity to emission heights has been examined with only a few models and is still uncertain. In this study we use the general circulation model ECHAM6 extended by the aerosol module HAM2 to investigate the impact of wildfire emission heights on atmospheric long-range transport, black carbon (BC) concentrations and atmospheric radiation. We simulate the wildfire aerosol release using either various versions of a semi-empirical plume height parametrization or prescribed standard emission heights in ECHAM6-HAM2. Extreme scenarios of near-surface or free-tropospheric-only injections provide lower and upper constraints on the emission height climate impact. We find relative changes in mean global atmospheric BC burden of up to 7.9±4.4 % caused by average changes in emission heights of 1.5-3.5 km. Regionally, changes in BC burden exceed 30-40 % in the major biomass burning regions. The model evaluation of aerosol optical thickness (AOT) against Moderate Resolution Imaging Spectroradiometer (MODIS), AErosol RObotic NETwork (AERONET) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations indicates that the implementation of a plume height parametrization slightly reduces the ECHAM6-HAM2 biases regionally, but on the global scale these improvements in model performance are small. For prescribed emission release at the surface, wildfire emissions entail a total sky top-of-atmosphere (TOA) radiative forcing (RF) of -0.16±0.06 W m-2. The application of a plume height parametrization which agrees reasonably well with observations introduces a slightly stronger negative TOA RF of -0.20±0.07 W m-2. The standard ECHAM6-HAM2 model in which 25 % of the wildfire emissions are injected

  10. The history, genotoxicity, and carcinogenicity of carbon-based fuels and their emissions. Part 3: diesel and gasoline.

    PubMed

    Claxton, Larry D

    2015-01-01

    Within this review the genotoxicity of diesel and gasoline fuels and emissions is placed in an historical context. New technologies have changed the composition of transportation methods considerably, reducing emissions of many of the components of health concern. The similarity of modern diesel and gasoline fuels and emissions to other carbonaceous fuels and emissions is striking. Recently an International Agency for Research on Cancer (IARC) Working Group concluded that there was sufficient evidence in humans for the carcinogenicity of diesel exhaust (Group 1). In addition, the Working Group found that diesel exhaust has "a positive association (limited evidence) with an increased risk of bladder cancer." Like most other carbonaceous fuel emissions, diesel and gasoline exhausts contain toxic levels of respirable particles (PM <2.5μm) and polycyclic aromatic hydrocarbons. However, the level of toxic components in exhausts from diesel and gasoline emissions has declined in certain regions over time because of changes in engine design, the development of better aftertreatment devices (e.g., catalysts), increased fuel economy, changes in the fuels and additives used, and greater regulation. Additional research and better exposure assessments are needed so that decision makers and the public can decide to what extent diesel and gasoline engines should be replaced. PMID:25795114

  11. Emissions Inventory Report Summary Reporting Requirements for the New Mexico Administrative Code, Title 20, Chapter 2, Part 73 (20 NMAC 2.73) for Calendar Year 1998

    SciTech Connect

    Air Quality Group, ESH-17

    1999-09-01

    Los Alamos National Laboratory (the Laboratory) is subject to emissions reporting requirements for regulated air contaminants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73 (20 NMAC 2.73), Notice of Intent and Emissions Inventory Requirements. The Laboratory has the potential to emit 100 tons per year of suspended particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, and volatile organic compounds. For 1998, combustion products from the industrial sources contributed the greatest amount of criteria air pollutants from the Laboratory. Research and development activities contributed the greatest amount of volatile organic compounds. Emissions of beryllium and aluminum were reported for activities permitted under 20 NMAC 2.72 Construction Permits.

  12. Compost spreading in Mediterranean shrubland indirectly increases biogenic emissions by promoting growth of VOC-emitting plant parts

    NASA Astrophysics Data System (ADS)

    Olivier, Romain; Lavoir, Anne-Violette; Ormeño, Elena; Mouillot, Florent; Greff, Stéphane; Lecareux, Caroline; Staudt, Michael; Fernandez, Catherine

    2011-07-01

    We investigated the effect of sewage sludge compost spreading on plant growth and leaf terpene emissions and content of Quercus coccifera, Rosmarinus officinalis and Cistus albidus in a Mediterranean shrubland. Measurements were performed during 3 consecutive summers on 2 different plots treated in 2002 or 2007 with 50 or 100 tons of compost per hectare, corresponding to observations carried out 2 months to 7 years after spreading. A slight nutrient enrichment of soil and leaves ( R. officinalis and C. albidus) was observed, especially for phosphorous. Terpene emissions were not affected by compost spreading, although they tended to increase on treated plots after 6 and 7 years for R. officinalis and C. albidus respectively. Terpene content was not affected by any compost treatment. Leaf and stem growth were significantly enhanced by compost spreading after 2 and/or 7 years in all species with little difference between doses. Total leaf biomass on the last growth units was increased by more than 50% in C. albidus and more than 90% in Q. coccifera. The results suggest that compost spreading in Meditteranean shrublands has no or little direct effect on leaf terpene emissions, but indirectly leads to their increase through leaf biomass enhancement. Simulation of terpene emissions at stand level revealed an increase of terpene fluxes ranging between 6 and 13%, depending on the plant species. Overall, compost spreading was assessed to result in an emission rate of 1.1 kg ha -1 y -1 for a typical Q. coccifera shrubland, but can reach 2.6 kg ha -1 y -1 for a typical R. officinalis shrubland.

  13. Emissions from residential combustion considering end-uses and spatial constraints: Part I, methods and spatial distribution

    NASA Astrophysics Data System (ADS)

    Winijkul, Ekbordin; Fierce, Laura; Bond, Tami C.

    2016-01-01

    This study describes a framework to attribute national-level atmospheric emissions in the year 2010 from the residential sector, one of the largest energy-related sources of aerosol emissions. We place special emphasis on end-uses, dividing usage into cooking, heating, lighting, and others. This study covers regions where solid biomass fuel provides more than 50% of total residential energy: Latin America, Africa, and Asia (5.2 billion people in 2010). Using nightlight data and population density, we classify five land types: urban, electrified rural with forest access, electrified rural without forest access, non-electrified rural with forest access, and non-electrified rural without forest access. We then apportion national-level residential fuel consumption among all land-types and end-uses, and assign end-use technologies to each combination. The resulting calculation gives spatially-distributed emissions of particulate matter, black carbon, organic carbon, nitrogen oxides, methane, non-methane hydrocarbons, carbon monoxide, and carbon dioxide. Within this study region, about 13% of the energy is consumed in urban areas, and 45% in non-urban land near forests. About half the energy is consumed in land without access to electricity. Cooking accounts for 54% of the consumption, heating for 9%, and lighting only 2%, with unidentified uses making up the remainder. Because biofuel use is assumed to occur preferentially where wood is accessible and electricity is not, our method shifts emissions to land types without electrification, compared with previous methods. The framework developed here is an important first step in acknowledging the role of household needs and local constraints in choosing energy provision. Although data and relationships described here need further development, this structure offers a more physically-based understanding of residential energy choices and, ultimately, opportunities for emission reduction.

  14. Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy - Part 1: Slant-columns and their ratios

    NASA Astrophysics Data System (ADS)

    Stremme, W.; Krueger, A.; Harig, R.; Grutter, M.

    2012-02-01

    The composition and emission rates of volcanic gas plumes provide insight of the geologic internal activity, atmospheric chemistry, aerosol formation and radiative processes around it. Observations are necessary for public security and the aviation industry. Ground-based thermal emission infrared spectroscopy, which uses the radiation of the volcanic gas itself, allows for continuously monitoring during day and night from a safe distance. We present measurements on Popocatépetl volcano based on thermal emission spectroscopy during different campaigns between 2006-2009 using a Scanning Infrared Gas Imaging System (SIGIS). The experimental set-up, measurement geometries and analytical algorithms are described. The equipment was operated from a safe distance of 12 km from the volcano at two different spectral resolutions: 0.5 and 4 cm-1. The 2-dimensional scanning capability of the instrument allows for an on-line visualization of the volcanic SO2 plume and its animation. SiF4 was also identified in the infrared spectra recorded at both resolutions. The SiF4/SO2 molecular ratio can be calculated from each image and used as a highly useful parameter to follow changes in volcanic activity. A small Vulcanian eruption was monitored during the night of 16 to 17 November 2008 and strong ash emission together with a pronounced SO2 cloud was registered around 01:00 a.m. LST (Local Standard Time). Enhanced SiF4/SO2 ratios were observed before and after the eruption. A validation of the results from thermal emission measurements with those from absorption spectra of the moon taken at the same time, as well as an error analysis, are presented. The inferred propagation speed from sequential images is used in a subsequent paper (Part 2) to calculate the emission rates at different distances from the crater.

  15. Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): part 2--morphological and mineralogical features.

    PubMed

    Calabrese, S; D'Alessandro, W

    2015-01-01

    Volcanic emissions were studied at Mount Etna (Italy) by using moss-bags technique. Mosses were exposed around the volcano at different distances from the active vents to evaluate the impact of volcanic emissions in the atmosphere. Morphology and mineralogy of volcanic particulate intercepted by mosses were investigated using scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS). Particles emitted during passive degassing activity from the two active vents, Bocca Nuova and North East Crater (BNC and NEC), were identified as silicates, sulfates and halide compounds. In addition to volcanic particles, we found evidences also of geogenic, anthropogenic and marine spray input. The study has shown the robustness of this active biomonitoring technique to collect particles, very useful in active volcanic areas characterized by continuous degassing and often not easily accessible to apply conventional sampling techniques. PMID:25311770

  16. Characterizing ammonia emissions from swine farms in eastern North Carolina: part 2--potential environmentally superior technologies for waste treatment.

    PubMed

    Aneja, Viney P; Arya, S Pal; Rumsey, Ian C; Kim, D-S; Bajwa, K; Arkinson, H L; Semunegus, H; Dickey, D A; Stefanski, L A; Todd, L; Mottus, K; Robarge, W P; Williams, C M

    2008-09-01

    The need for developing environmentally superior and sustainable solutions for managing the animal waste at commercial swine farms in eastern North Carolina has been recognized in recent years. Program OPEN (Odor, Pathogens, and Emissions of Nitrogen), funded by the North Carolina State University Animal and Poultry Waste Management Center (APWMC), was initiated and charged with the evaluation of potential environmentally superior technologies (ESTs) that have been developed and implemented at selected swine farms or facilities. The OPEN program has demonstrated the effectiveness of a new paradigm for policy-relevant environmental research related to North Carolina's animal waste management programs. This new paradigm is based on a commitment to improve scientific understanding associated with a wide array of environmental issues (i.e., issues related to the movement of N from animal waste into air, water, and soil media; the transmission of odor and odorants; disease-transmitting vectors; and airborne pathogens). The primary focus of this paper is on emissions of ammonia (NH3) from some potential ESTs that were being evaluated at full-scale swine facilities. During 2-week-long periods in two different seasons (warm and cold), NH3 fluxes from water-holding structures and NH3 emissions from animal houses or barns were measured at six potential EST sites: (1) Barham farm--in-ground ambient temperature anaerobic digester/energy recovery/greenhouse vegetable production system; (2) BOC #93 farm--upflow biofiltration system--EKOKAN; (3) Carrolls farm--aerobic blanket system--ISSUES-ABS; (4) Corbett #1 farm--solids separation/ gasification for energy and ash recovery centralized system--BEST; (5) Corbett #2 farm--solid separation/ reciprocating water technology--ReCip; and (6) Vestal farm--Recycling of Nutrient, Energy and Water System--ISSUES-RENEW. The ESTs were compared with similar measurements made at two conventional lagoon and spray technology (LST) farms (Moore

  17. The history, genotoxicity, and carcinogenicity of carbon-based fuels and their emissions: part 5. Summary, comparisons, and conclusions.

    PubMed

    Claxton, Larry D

    2015-01-01

    As seen through the previous reviews, each carbonaceous source of energy is associated with genotoxic and carcinogenic health risks; however, energy use is central to human society and provides many health benefits. These reviews examined the genotoxicity of carbonaceous sources of energy, focusing on the impacts due to the combustion of fuels and biomass. In previous reviews, information and data were used to examine occupational, industrial, household, and general environmental pollution as well as laboratory research. In this final summation, the effort is not only to summarize the previous reviews but to provide additional information to support any final conclusions. Included in the final observations are: (1) emissions from combusted carbonaceous fuels are very likely to include genotoxicants and/or carcinogens, and, as such, they can considerably increase the risk of adverse health effects in exposed humans, (2) environmental transformation is likely to increase genotoxicity of emissions, and (3) the world's poor households have an increased health risk because they have limited access to clean fuels and electricity. Because carbonaceous fuel emissions are highly complex, risk assessments are difficult; however, decision makers have many toxicological approaches for evaluating emissions. Although energy efficiency brings many benefits, it also involves health risks, as do renewable energy systems, if not managed carefully. The reviews do not examine climate change or non-carbonaceous fuels (e.g., nuclear fuels). Because these are not papers about the risk assessment or regulation of pollutants from carbon-based fuels, the discussions of regulations were to place research, concerns, and actions into a historical reference for the reader. PMID:25795116

  18. Assessment of air quality benefits from national air pollution control policies in China. Part I: Background, emission scenarios and evaluation of meteorological predictions

    NASA Astrophysics Data System (ADS)

    Wang, Litao; Jang, Carey; Zhang, Yang; Wang, Kai; Zhang, Qiang; Streets, David; Fu, Joshua; Lei, Yu; Schreifels, Jeremy; He, Kebin; Hao, Jiming; Lam, Yun-Fat; Lin, Jerry; Meskhidze, Nicholas; Voorhees, Scott; Evarts, Dale; Phillips, Sharon

    2010-09-01

    Under the 11th Five Year Plan (FYP, 2006-2010) for national environmental protection by the Chinese government, the overarching goal for sulfur dioxide (SO 2) controls is to achieve a total national emissions level of SO 2 in 2010 10% lower than the level in 2005. A similar nitrogen oxides (NO x) emissions control plan is currently under development and could be enforced during the 12th FYP (2011-2015). In this study, the U.S. Environmental Protection Agency (U.S.EPA)'s Community Multi-Scale Air Quality (Models-3/CMAQ) modeling system was applied to assess the air quality improvement that would result from the targeted SO 2 and NO x emission controls in China. Four emission scenarios — the base year 2005, the 2010 Business-As-Usual (BAU) scenario, the 2010 SO 2 control scenario, and the 2010 NO x control scenario—were constructed and simulated to assess the air quality change from the national control plan. The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) was applied to generate the meteorological fields for the CMAQ simulations. In this Part I paper, the model performance for the simulated meteorology was evaluated against observations for the base case in terms of temperature, wind speed, wind direction, and precipitation. It is shown that MM5 model gives an overall good performance for these meteorological variables. The generated meteorological fields are acceptable for using in the CMAQ modeling.

  19. Emissions Inventory Report Summary: Reporting Requirements for the New Mexico Administrative Code, Title 20, Chapter 2, Part 73 (20.2.73 NMAC) for Calendar Year 2003

    SciTech Connect

    M. Stockton

    2005-01-01

    Los Alamos National Laboratory is subject to annual emissions-reporting requirements for regulated air pollutants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73 (20.2.73 NMAC), Notice of Intent and Emissions Inventory Requirements. The applicability of the requirements is based on the Laboratory's potential to emit 100 tons per year of suspended particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, or volatile organic compounds. For calendar year 2003, the Technical Area 3 steam plant and the air curtain destructors were the primary sources of criteria air pollutants from the Laboratory, while the air curtain destructors and chemical use associated with research and development activities were the primary sources of volatile organic compounds and hazardous air pollutants. Emissions of beryllium and aluminum were reported for activities permitted under 20.2.72 NMAC. Hazardous air pollutant emissions were reported from chemical use as well as from all combustion sources. In addition, estimates of particulate matter with diameter less than 2.5 micrometers and ammonia were provided as requested by the New Mexico Environment Department, Air Quality Bureau.

  20. N2O Emissions in Southeastern Amazonia: The Effect of Agricultural Intensification

    NASA Astrophysics Data System (ADS)

    O'Connell, C.; Brando, P. M.; Cerri, C. E.; Coe, M. T.; Davidson, E. A.; Galford, G. L.; Macedo, M.; Neill, C.; Venterea, R. T.

    2014-12-01

    The Amazon is not only an exceptionally biodiverse and carbon-rich tract of tropical forest, it is also a case study in land use change. Over the last 30 years, Amazonia has been home to extraordinary growth in agricultural production, in part from agricultural expansion, but also due to more intense management on Amazonia's existing croplands. We use a year-long campaign and approximately 500 field chamber measurements to estimate how cropland intensification in Mato Grosso, Brazil affects the emission of nitrous oxide (N2O) and soil N dynamics. In this system, soybean cropland intensification occurs when double cropping is introduced, in which maize is planted directly after soybean harvest and fertilized twice with inorganic N. We find that dry season N2O emissions in single-cropped (soybean only) fields, double-cropped (soybean/maize) fields and reference tropical forest are uniformly near zero, or ~0-0.5 ngN/cm^2/hr. Surprisingly, wet season emissions rates remain low as well, between 1-4 ngN/cm^2/hr, for both cropland types and reference forest. By contrast, isolated post-fertilization spikes in N2O emissions are large, with a maximum increase of ~800% and a mean increase of ~400%, though these flux increases resolve rapidly and rates return to their low baseline within days. Finally, we explore the role that soil moisture, soil N availability, and soil C availability play in regulating N2O fluxes in reference forest, soybean fields and intensified soybean-maize fields. Open questions surround how the Amazon's land resources can be leveraged to increase agricultural production at the least harm to the environment. Here, we quantify the consequences of land use change on N2O, a powerful greenhouse gas, in a critical ecosystem undergoing novel agricultural intensification. These results may inform both greenhouse gas accounting and our understanding of the effects of Amazonia's changing agricultural landscape on the nitrogen cycle.

  1. 23 CFR Appendix A to Part 772 - National Reference Energy Mean Emission Levels as a Function of Speed

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., 109 Stat. 568, 605; 49 CFR 1.48(b). § 772.1 Purpose. To provide procedures for noise studies and noise... Impact (FONSI), or the Record of Decision (ROD), as defined in 23 CFR part 771. Design year. The future...) of title 5, U.S.C. and part 51 of title 1, CFR, and are on file at the National Archives and...

  2. Simultaneous Photoacoustic and Photopyroelectric Detection of Trace Gas Emissions from Some Plant Parts and Their Related Essential Oils in a Combined Detection Cell

    NASA Astrophysics Data System (ADS)

    Abu-Taha, M. I.; Abu-Teir, M. M.; Al-Jamal, A. J.; Eideh, H.

    The aim of this work was to establish the feasibility of the combined photoacoustic (PA) and photopyroelectric (PPE) detection of the vapours emitted from essential oils and their corresponding uncrushed leaves or flowers. Gas traces of jasmine (Jessamine (Jasminum)), mint (Mentha arvensis L.) and Damask rose (Rosa damascena Miller) and their essential oils were tested using a combined cell fitted with both a photopyroelectric film (PVDF) and a microphone in conjunction with a pulsed wideband infrared source (PWBS) source. Infrared PA and PPE absorbances were obtained simultaneously at room temperatures with excellent reproducibility and high signal-to-noise ratios. Significant similarities found between the PA and PPE spectra of the trace gas emissions of plant parts, i.e., flowers or leaves and their related essential oils show the good correlation of their emissions and that both effects are initiated by the same absorbing molecules.

  3. Uncontrolled combustion of shredded tires in a landfill – Part 1: Characterization of gaseous and particulate emissions

    PubMed Central

    Downard, Jared; Singh, Ashish; Bullard, Robert; Jayarathne, Thilina; Rathnayake, Chathurika; Simmons, Donald L.; Wels, Brian R.; Spak, Scott N.; Peters, Thomas; Beardsley, Douglas; Stanier, Charles; Stone, Elizabeth A.

    2014-01-01

    In summer 2012, a landfill liner comprising an estimated 1.3 million shredded tires burned in Iowa City, Iowa. During the fire, continuous monitoring and laboratory measurements were used to characterize the gaseous and particulate emissions and to provide new insights into the qualitative nature of the smoke and the quantity of pollutants emitted. Significant enrichments in ambient concentrations of CO, CO2, SO2, particle number (PN), fine particulate (PM2.5) mass, elemental carbon (EC), and polycyclic aromatic hydrocarbons (PAH) were observed. For the first time, PM2.5 from tire combustion was shown to contain PAH with nitrogen heteroatoms (a.k.a. azaarenes) and picene, a compound previously suggested to be unique to coal-burning. Despite prior laboratory studies’ findings, metals used in manufacturing tires (i.e. Zn, Pb, Fe) were not detected in coarse particulate matter (PM10) at a distance of 4.2 km downwind. Ambient measurements were used to derive the first in situ fuel-based emission factors (EF) for the uncontrolled open burning of tires, revealing substantial emissions of SO2 (7.1 g kg−1), particle number (3.5×1016 kg−1), PM2.5 (5.3 g kg−1), EC (2.37 g kg−1), and 19 individual PAH (totaling 56 mg kg−1). A large degree of variability was observed in day-to-day EF, reflecting a range of flaming and smoldering conditions of the large-scale fire, for which the modified combustion efficiency ranged from 0.85-0.98. Recommendations for future research on this under-characterized source are also provided. PMID:25663800

  4. Effects of engine emissions from high-speed civil transport aircraft: A two-dimensional modeling study, part 2

    NASA Technical Reports Server (NTRS)

    Ko, Malcolm K. W.; Weisenstein, Debra K.; Sze, Nein Dak; Shia, Run-Lie; Rodriguez, Jose M.; Heisey, Curtis

    1991-01-01

    The AER two-dimensional chemistry-transport model is used to study the effect of supersonic and subsonic aircraft operation in the 2010 atmosphere on stratospheric ozone (O3). The results show that: (1) the calculated O3 response is smaller in the 2010 atmosphere compared to previous calculations performed in the 1980 atmosphere; (2) with the emissions provided, the calculated decrease in O3 column is less than 1 percent; and (3) the effect of model grid resolution on O3 response is small provided that the physics is not modified.

  5. Environmental analysis of a construction and demolition waste recycling plant in Portugal--Part I: energy consumption and CO2 emissions.

    PubMed

    Coelho, André; de Brito, Jorge

    2013-05-01

    This work is a part of a wider study involving the economic and environmental implications of managing construction and demolition waste (CDW), focused on the operation of a large scale CDW recycling plant. This plant, to be operated in the Lisbon Metropolitan Area (including the Setúbal peninsula), is analysed for a 60 year period, using primary energy consumption and CO2eq emission impact factors as environmental impact performance indicators. Simplified estimation methods are used to calculate industrial equipment incorporated, and the operation and transport related impacts. Material recycling--sorted materials sent to other industries, to act as input--is taken into account by discounting the impacts related to industrial processes no longer needed. This first part focuses on calculating the selected impact factors for a base case scenario (with a 350 tonnes/h installed capacity), while a sensitivity analysis is provided in part two. Overall, a 60 year global primary energy consumption of 71.4 thousand toe (tonne of oil equivalent) and a total CO2eq emission of 135.4 thousand tonnes are expected. Under this operating regime, around 563 thousand toe and 1465 thousand tonnes CO2eq could be prevented by replacing raw materials in several construction materials industries (e.g.: ferrous and non-ferrous metals, plastics, paper and cardboard). PMID:23422042

  6. Inherently low-emission vehicle program, estimated emission benefits and impact on high-occupancy vehicle lanes. Technical report

    SciTech Connect

    Wyborny, L.

    1992-10-01

    According to the detailed analysis in the report, ILEVs would provide substantial emission reductions compared to LEVs and other conventional vehicles. The evaporative and refueling emissions (vapor emissions) from ILEVs are estimated to be near zero. With the near-elimination of vapor emissions, ILEVs are expected to emit about one-half the volatile organic compound emissions as other LEVs. The report also concludes that ILEVs are expected to result in little or no detrimental effect on traffic flow in HOV lanes. This conclusion was derived from studying the HOV lanes in Los Angeles, Houston, the District of Columbia, and Seattle. Overall, the report concludes that widespread and rapid introduction of ILEVs would generally offer significant air quality benefits to society wherever they are used, and that the prudent use of TCM exemptions and incentives could encourage these purchases without significant impact on the effectiveness of the other programs.

  7. Traditional vs Modern: Role of Breed Type in Determining Enteric Methane Emissions from Cattle Grazing as Part of Contrasting Grassland-Based Systems

    PubMed Central

    Fraser, Mariecia D.; Fleming, Hannah R.; Moorby, Jon M.

    2014-01-01

    Ruminant livestock turn forages and poor-quality feeds into human edible products, but enteric methane (CH4) emissions from ruminants are a significant contributor to greenhouse gases (GHGs) and hence to climate change. Despite the predominance of pasture-based beef production systems in many parts of Europe there are little data available regarding enteric CH4 emissions from free-ranging grazing cattle. It is possible that differences in physiology or behaviour could influence comparative emissions intensities for traditional and modern breed types depending on the nutritional characteristics of the herbage grazed. This study investigated the role of breed type in influencing CH4 emissions from growing beef steers managed on contrasting grasslands typical of intensive (lowland) and extensive (upland) production systems. Using the SF6 dilution technique CH4 emissions were estimated for a modern, fast-growing crossbred (Limousin cross) and a smaller and hardier native breed (Welsh Black) when grazing lowland perennial ryegrass (high nutritional density, low sward heterogeneity) and semi-improved upland pasture (low/medium nutritional density, high sward heterogeneity). Live-weight gain was substantially lower for steers on the upland system compared to the lowland system (0.31 vs. 1.04 kg d−1; s.e.d. = 0.085 kg d−1; P<0.001), leading to significant differences in estimated dry matter intakes (8.0 vs. 11.1 kg DM d−1 for upland and lowland respectively; s.e.d. = 0.68 kg DM d−1; P<0.001). While emissions per unit feed intake were similar for the lowland and upland systems, CH4 emissions per unit of live-weight gain (LWG) were substantially higher when the steers grazed the poorer quality hill pasture (760 vs 214 g kg−1 LWG; s.e.d. = 133.5 g kg−1 LWG; P<0.001). Overall any effects of breed type were relatively small relative to the combined influence of pasture type and location. PMID:25259617

  8. Traditional vs modern: role of breed type in determining enteric methane emissions from cattle grazing as part of contrasting grassland-based systems.

    PubMed

    Fraser, Mariecia D; Fleming, Hannah R; Moorby, Jon M

    2014-01-01

    Ruminant livestock turn forages and poor-quality feeds into human edible products, but enteric methane (CH4) emissions from ruminants are a significant contributor to greenhouse gases (GHGs) and hence to climate change. Despite the predominance of pasture-based beef production systems in many parts of Europe there are little data available regarding enteric CH4 emissions from free-ranging grazing cattle. It is possible that differences in physiology or behaviour could influence comparative emissions intensities for traditional and modern breed types depending on the nutritional characteristics of the herbage grazed. This study investigated the role of breed type in influencing CH4 emissions from growing beef steers managed on contrasting grasslands typical of intensive (lowland) and extensive (upland) production systems. Using the SF6 dilution technique CH4 emissions were estimated for a modern, fast-growing crossbred (Limousin cross) and a smaller and hardier native breed (Welsh Black) when grazing lowland perennial ryegrass (high nutritional density, low sward heterogeneity) and semi-improved upland pasture (low/medium nutritional density, high sward heterogeneity). Live-weight gain was substantially lower for steers on the upland system compared to the lowland system (0.31 vs. 1.04 kg d-1; s.e.d. = 0.085 kg d-1; P<0.001), leading to significant differences in estimated dry matter intakes (8.0 vs. 11.1 kg DM d-1 for upland and lowland respectively; s.e.d. = 0.68 kg DM d-1; P<0.001). While emissions per unit feed intake were similar for the lowland and upland systems, CH4 emissions per unit of live-weight gain (LWG) were substantially higher when the steers grazed the poorer quality hill pasture (760 vs 214 g kg-1 LWG; s.e.d. = 133.5 g kg-1 LWG; P<0.001). Overall any effects of breed type were relatively small relative to the combined influence of pasture type and location. PMID:25259617

  9. 40 CFR Appendix C to Part 136 - Inductively Coupled Plasma-Atomic Emission Spectrometric Method for Trace Element Analysis of...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Publication No. 77-206, August 1977. 14.8“OSHA Safety and Health Standards, General Industry,” (29 CFR part... stoppered and store in a desiccator to prevent the entrance of atmospheric moisture. 7.3.7Cadmium solution... in Academic Chemistry Laboratories, American Chemical Society Publication, Committee on...

  10. 40 CFR Appendix C to Part 136 - Inductively Coupled Plasma-Atomic Emission Spectrometric Method for Trace Element Analysis of...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Publication No. 77-206, August 1977. 14.8“OSHA Safety and Health Standards, General Industry,” (29 CFR part... stoppered and store in a desiccator to prevent the entrance of atmospheric moisture. 7.3.7Cadmium solution... in Academic Chemistry Laboratories, American Chemical Society Publication, Committee on...

  11. 49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may inspect a... E 1354-99, the heat evolved from a specimen per unit of time. Specific extinction area (σf) means, as defined in ASTM E 1354-99, specific extinction area for smoke. Specific optical density (Ds)...

  12. 49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may inspect a... E 1354-99, the heat evolved from a specimen per unit of time. Specific extinction area (σf) means, as defined in ASTM E 1354-99, specific extinction area for smoke. Specific optical density (Ds)...

  13. 49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may inspect a... E 1354-99, the heat evolved from a specimen per unit of time. Specific extinction area (σf) means, as defined in ASTM E 1354-99, specific extinction area for smoke. Specific optical density (Ds)...

  14. 49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may inspect a... E 1354-99, the heat evolved from a specimen per unit of time. Specific extinction area (σf) means, as defined in ASTM E 1354-99, specific extinction area for smoke. Specific optical density (Ds)...

  15. 49 CFR Appendix B to Part 238 - Test Methods and Performance Criteria for the Flammability and Smoke Emission Characteristics of...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may inspect a... E 1354-99, the heat evolved from a specimen per unit of time. Specific extinction area (σf) means, as defined in ASTM E 1354-99, specific extinction area for smoke. Specific optical density (Ds)...

  16. Effects of engine emissions from high-speed civil transport aircraft: A two-dimensional modeling study, part 1

    NASA Technical Reports Server (NTRS)

    Ko, Malcolm K. W.; Weisenstein, Debra K.; Sze, Nein Dak; Rodriguez, Jose M.; Heisey, Curtis

    1991-01-01

    The AER two-dimensional chemistry-transport model is used to study the effect on stratospheric ozone (O3) from operations of supersonic and subsonic aircraft. The study is based on six emission scenarios provided to AER. The study showed that: (1) the O3 response is dominated by the portion of the emitted nitrogen compounds that is entrained in the stratosphere; (2) the entrainment is a sensitive function of the altitude at which the material is injected; (3) the O3 removal efficiency of the emitted material depends on the concentrations of trace gases in the background atmosphere; and (4) evaluation of the impact of fleet operations in the future atmosphere must take into account the expected changes in trace gas concentrations from other activities. Areas for model improvements in future studies are also discussed.

  17. Acoustic monitoring of gas emissions from the seafloor. Part II: a case study from the Sea of Marmara

    NASA Astrophysics Data System (ADS)

    Bayrakci, Gaye; Scalabrin, Carla; Dupré, Stéphanie; Leblond, Isabelle; Tary, Jean-Baptiste; Lanteri, Nadine; Augustin, Jean-Marie; Berger, Laurent; Cros, Estelle; Ogor, André; Tsabaris, Christos; Lescanne, Marc; Géli, Louis

    2014-09-01

    A rotating, acoustic gas bubble detector, BOB (Bubble OBservatory) module was deployed during two surveys, conducted in 2009 and 2011 respectively, to study the temporal variations of gas emissions from the Marmara seafloor, along the North Anatolian Fault zone. The echosounder mounted on the instrument insonifies an angular sector of 7° during a given duration (of about 1 h). Then it rotates to the next, near-by angular sector and so forth. When the full angular domain is insonified, the "pan and tilt system" rotates back to its initial position, in order to start a new cycle (of about 1 day). The acoustic data reveal that gas emission is not a steady process, with observed temporal variations ranging between a few minutes and 24 h (from one cycle to the other). Echo-integration and inversion performed on the acoustic data as described in the companion paper of Leblond et al. (Mar Geophys Res, 2014), also indicate important variations in, respectively, the target strength and the volumetric flow rates of individual sources. However, the observed temporal variations may not be related to the properties of the gas source only, but reflect possible variations in sea-bottom currents, which could deviate the bubble train towards the neighboring sector. During the 2011 survey, a 4-component ocean bottom seismometer (OBS) was co-located at the seafloor, 59 m away from the BOB module. The acoustic data from our rotating, monitoring system support, but do not provide undisputable evidence to confirm, the hypothesis formulated by Tary et al. (2012), that the short-duration, non-seismic micro-events recorded by the OBS are likely produced by gas-related processes within the near seabed sediments. Hence, the use of a multibeam echosounder, or of several split beam echosounders should be preferred to rotating systems, for future experiments.

  18. The history, genotoxicity, and carcinogenicity of carbon-based fuels and their emissions. Part 2: solid fuels.

    PubMed

    Claxton, Larry D

    2014-01-01

    The combustion of solid fuels (like wood, animal dung, and coal) usually involves elevated temperatures and altered pressures and genotoxicants (e.g., PAHs) are likely to form. These substances are carcinogenic in experimental animals, and epidemiological studies implicate these fuels (especially their emissions) as carcinogens in man. Globally, ∼50% of all households and ∼90% of all rural households use solid fuels for cooking or heating and these fuels often are burnt in simple stoves with very incomplete combustion. Exposed women and children often exhibit low birth weight, increased infant and perinatal mortality, head and neck cancer, and lung cancer although few studies have measured exposure directly. Today, households that cannot meet the expense of fuels like kerosene, liquefied petroleum gas, and electricity resort to collecting wood, agricultural residue, and animal dung to use as household fuels. In the more developed countries, solid fuels are often used for electric power generation providing more than half of the electricity generated in the United States. The world's coal reserves, which equal approximately one exagram, equal ∼1 trillion barrels of crude oil (comparable to all the world's known oil reserves) and could last for 600 years. Studies show that the PAHs that are identified in solid fuel emissions react with NO2 to form direct-acting mutagens. In summary, many of the measured genotoxicants found in both the indoor and electricity-generating combustors are the same; therefore, the severity of the health effects vary with exposure and with the health status of the exposed population. PMID:25475420

  19. Potential radionuclide emissions from stacks on the Hanford site, Part 2: Dose assessment methodology using portable low-resolution gamma spectroscopy

    SciTech Connect

    Barnett, J.M.

    1995-02-01

    In September 1992, the Westinghouse Hanford Company began developing an in situ measurement method to assess gamma radiation emanating from high-efficiency particulate air filters using portable low-resolution gamma spectroscopy. The purpose of the new method was to assess radioactive exhaust stack air emissions from empirical data rather than from theoretical models and to determine the potential unabated dose to an offsite theoretical maximally exposed individual. In accordance with Title 40, Code of Federal Regulations, Part 61, Subpart H, {open_quotes}National Emission Standards for Hazardous Air Pollutants{close_quotes}, stacks that have the potential to emit {ge} 1 {mu}Sv y{sup {minus}1} (0.1 mrem y{sup {minus}1}) to the maximally exposed individual are considered {open_quotes}major{close_quotes} and must meet the continuous monitoring requirements. After the method was tested and verified, the U.S. Environmental Protection Agency, Region 10, approved its use in June 1993. Of the 125 stacks operated by the Westinghouse Hanford Company, 22 were targeted for evaluation by this method, and 15 were assessed. (The method could not be applied at seven stacks because of excessive background radiation or because no gamma emitting particles appear in the emission stream.) The most significant result from this study was the redesignation of the T Plant main stack. The stack was assessed as being {open_quotes}minor{close_quotes}, and it now only requires periodic confirmatory measurements and meets federally imposed sampling requirements.

  20. Rural Development Inc.-Wisdom Way: Near Zero Energy

    SciTech Connect

    2009-03-23

    This case study describes a community of efficient,affordable solar homes, featuring superior insulation, high performance windows, single,sealed-combustion, natural gas unit heaters, and photovoltaics.

  1. Method of Bonding Optical Elements with Near-Zero Displacement

    NASA Technical Reports Server (NTRS)

    Robinson, David; McClelland, Ryan; Byron, Glenn; Evans, Tyler

    2012-01-01

    The International X-ray Project seeks to build an x-ray telescope using thousands of pieces of thin and flexible glass mirror segments. Each mirror segment must be bonded into a housing in nearly perfect optical alignment without distortion. Forces greater than 0.001 Newton, or displacements greater than 0.5 m of the glass, cause unacceptable optical distortion. All known epoxies shrink as they cure. Even the epoxies with the least amount of shrinkage (<0.01%) cause unacceptable optical distortion and misalignment by pulling the mirror segments towards the housing as it cures. A related problem is that the shrinkage is not consistent or predictable so that it cannot be accounted for in the setup (i.e., if all of the bonds shrunk an equal amount, there would be no problem). A method has been developed that allows two components to be joined with epoxy in such a way that reduces the displacement caused by epoxy shrinking as it cures to less than 200 nm. The method involves using ultraviolet-cured epoxy with a displacement sensor and a nanoactuator in a control loop. The epoxy is cured by short-duration exposures to UV light. In between each exposure, the nano-actuator zeroes out the displacement caused by epoxy shrinkage and thermal expansion. After a few exposures, the epoxy has cured sufficiently to prevent further displacement of the two components. Bonding of optical elements has been done for many years, but most optics are thick and rigid elements that resist micro-Newton-level forces without causing distortion. When bonding thin glass optics such as the 0.40-mm thick IXO X-ray mirrors, forces in the micro- and milli-Newton levels cause unacceptable optical figure error. This innovation can now repeatedly and reliably bond a thin glass mirror to a metal housing with less than 0.2 m of displacement (<200 nm). This is an enabling technology that allows the installation of virtually stress-free, undistorted thin optics onto structures. This innovation is applicable to the bonding of thin optical elements, or any thin/flexible structures, that must be attached in an undistorted, consistent, and aligned way.

  2. EFFECTIVE ACIDITY CONSTANT BEHAVIOR NEAR ZERO CHARGE CONDITIONS

    EPA Science Inventory

    Surface site (>SOH group) acidity reactions require expressions of the form: Ka = [>SOHn-1(z-1)]aH+EXP(-DG/RT)/[>SOHnz] (where all variables have their usual meaning). One can rearrange this expression to generate an effective acidity constant historically defined as: Qa = Ka...

  3. Near Zero ev Subexcitation Energy Electrons Break DNA

    NASA Astrophysics Data System (ADS)

    Martin, Frederic; Cai, Zhongli; Cloutier, Pierre; Hunting, Darel; Sanche, Leon

    2004-03-01

    The passage of ionizing radiation through a living cell produces about 4 x 10^4 electrons/MeV, with more than 50% having energies well below the excitation threshold for water (7-8 eV) (M. Michaud et al, Physical Review, 44(9), 5623-5627, (1991)). We have previously shown that 5-20eV electrons cause DNA strand breaks via a resonant process with a maximum at 10eV (B. Boudaiffa et al, Science 287, 1658-1660, (2000)). The present results demonstrate that very low energy electrons in the range of 0 to 5eV cause single strand breaks (SSB) in DNA. Plasmid DNA is extracted from the host bacteria purified and resuspended in distilled and deionised water. It is deposited on a chemically clean tantalum, lyophilised and placed in an UHV chamber for 24 hours before irradiation. After irradiation, plasmid DNA is retrieved from the UHV chamber and the samples are dissolved in tris buffer. The different topological forms of DNA resulting from single strand break formation are separated by electrophoresis gel, stained by SYBR Green 1, scanned by laser and quantified with the imageQuant program. The quantification protocol has been optimized to maximize both sensitivity and linearity. Two resonant peaks are observed with maxima at 0,8 eV and 2,2 eV ( 10,5 and 7,5 ssb per 10^3 electrons, respectively).

  4. 10 MW(e) prototype testing of LIDS{trademark} as part of the Babcock and Wilcox low emission boiler system

    SciTech Connect

    Madden, D.A.; Musiol, W.F.

    1996-12-31

    Babcock and Wilcox (B and W) is currently developing the Limestone Injection and Dry Scrubbing (LIDS) system to be capable of reducing SO{sub x} and particulate emissions significantly below that allowed under the New Source Performance Standards (NSPS) while addressing the concerns of solid waste generation and air toxics regulation. The work is being performed as an integral part of B and W`s development of an advanced low-emission boiler system in a project entitled, Engineering Development of Advanced Coal-Fired Low Emission Boiler Systems (LEBS). The overall goal of the DOE`s program is to dramatically improve environmental performance and thermal efficiency of conventional, Rankine cycle, coal-fired power plants. The LIDS process is a limestone-based, furnace injection/dry scrubbing SO{sub 2} removal process. The process comprises the cost-effective integration of three commercially proven flue gas cleanup technologies: furnace limestone injection, dry scrubbing, and pulse-jet fabric filtration. This paper highlights the plans for 10 MW, LIDS testing to be performed in B and W`s world-class Clean Environment Development Facility to demonstrate the B and W LEBS project SO{sub 2} removal goal of 98% and particulate emissions goal of less than 0.005 lb/10{sup 6} Btu under cost-effective operating conditions. Air toxics control and solids by-product issues will be addressed. The paper also includes plans for LIDS in the Proof-of-Concept demonstration in Phase 4.

  5. The history, genotoxicity and carcinogenicity of carbon-based fuels and their emissions: part 4 - alternative fuels.

    PubMed

    Claxton, Larry D

    2015-01-01

    Much progress has been made in reducing the pollutants emitted from various combustors (including diesel engines and power plants) by the use of alternative fuels; however, much more progress is needed. Not only must researchers improve fuels and combustors, but also there is a need to improve the toxicology testing and analytical chemistry methods associated with these complex mixtures. Emissions from many alternative carbonaceous fuels are mutagenic and carcinogenic. Depending on their source and derivation, alternative carbonaceous fuels before combustion may or may not be genotoxic; however, in order to know their genotoxicity, appropriate chemical analysis and/or bioassay must be performed. Newly developed fuels and combustors must be tested to determine if they provide a public health advantage over existing technologies - including what tradeoffs can be expected (e.g., decreasing levels of PAHs versus increasing levels of NOx and possibly nitroarenes in ambient air). Another need is to improve exposure estimations which presently are a weak link in doing risk analyses. PMID:25795115

  6. Salinity effects on the microwave emission of soils

    NASA Technical Reports Server (NTRS)

    Jackson, Thomas J.; Oneill, Peggy E.

    1987-01-01

    Controlled plot experiments were conducted to collect L and C band passive microwave data concurrent with ground observations of salinity and soil moisture. Two dielectric mixing models were used with an emission model to predict the emissivity from a bare smooth uniform profile. The models produce nearly identical results when near zero salinity is involved and reproduce the observed data at L band extremely well. Discrepancies at C band are attributed to sampling depth problems. Comparisons of predicted emissivities at various salinities with observed values indicate that the dynamic range of the emissivities can be explained using either of the dielectric mixing models. Evaluation of the entire data set, which included four salinity levels, indicates that for general application the effects of soil salinity can be ignored in interpreting microwave data for estimating soil moisture under most agricultural conditions.

  7. Effects of salinity on the microwave emission of soils

    NASA Technical Reports Server (NTRS)

    Jackson, T. J.; Oneill, P. E.

    1986-01-01

    Controlled plot experiments were conducted to collect L and C band passive microwave data concurrent with ground observations of salinity and soil moisture. Two dielectric mixing models were used with an emission model to predict the emissivity from a bare smooth uniform profile. The models produce nearly identical results when near zero salinity is involved and reproduce the observed data at L band extremely well. Discrepancies at C band are attributed to sampling depth problems. Comparisons of predicted emissivities at various salinities with observed values indicate that the dynamic range of the emissivities can be explained using either of the dielectric mixing models. Evaluation of the entire data set, which included four salinity levels, indicates that for general application the effects of soil salinity can be ignored in interpreting microwave data for estimating soil moisture under most agricultural conditions.

  8. CO{sub 2} emission abatement in IGCC power plants by semiclosed cycles: Part A -- With oxygen-blown combustion

    SciTech Connect

    Chiesa, P.; Lozza, G.

    1999-10-01

    This paper analyzes the fundamentals of IGCC power plants where carbon dioxide produced by syngas combustion can be removed, liquefied and eventually disposed, to limit the environmental problems due to the greenhouse effect. To achieve this goal, a semiclosed-loop gas turbine cycle using an highly-enriched CO{sub 2} mixture as working fluid was adopted. As the oxidizer, the syngas combustion utilizes oxygen produced by an air separation unit. Combustion gases mainly consist of CO{sub 2} and H{sub 2}O: after expansion, heat recovery and water condensation, a part of the exhausts, highly concentrated in CO{sub 2}, can be easily extracted, compressed and liquefied for storage or disposal. A detailed discussion about the configuration and the thermodynamic performance of these plants is the aim of the paper. Proper attention was paid to: (i) the modelization of the gasification section and of its integration with the power cycle, (ii) the optimization of pressure ratio due the change of the cycle working fluid, (iii) the calculation of the power consumption of the auxiliary equipment, including the compression train of the separated CO{sub 2} and the air separation unit. The resulting overall efficiency is in the 38--39% range, with status-of-the-art gas turbine technology, but resorting to a substantially higher pressure ratio. The extent of modifications to the gas turbine engine, with respect to commercial units, was therefore discussed. Relevant modifications are needed, but not involving changes in the technology. A second plant scheme will be considered in the second part of the paper, using air for syngas combustion and a physical absorption process to separate CO{sub 2} from nitrogen-rich exhausts. A comparison between the two options will be addressed there.

  9. Use of portable FTIR spectrometers for detecting greenhouse gas emissions of the megacity Berlin - Part 2: Observed time series of XCO2 and XCH4

    NASA Astrophysics Data System (ADS)

    Hase, F.; Frey, M.; Blumenstock, T.; Groß, J.; Kiel, M.; Kohlhepp, R.; Mengistu Tsidu, G.; Schäfer, K.; Sha, M. K.; Orphal, J.

    2015-03-01

    Five portable Bruker EM27/SUN FTIR spectrometers have been used for the accurate and precise observation of column averaged abundances of CO2 and CH4 around the megacity Berlin. In the first part of this work (Frey et al., 2015) we have presented the various measures that were undertaken to ensure that the observations are consistent between sites, accurate and precise. Here, we present the recorded time series of XCH4 and XCO2 and demonstrate that the CO2 emissions of Berlin can be clearly identified in the observations. A simple dispersion model is applied which indicates a total strength of the Berlin source of about 0.8 t CO2 s-1. In the Supplement of this work, we provide the measured dataset and auxiliary data. We hope that the model community will exploit this unique dataset for state-of-the art inversion studies of CO2 and CH4 sources in the Berlin area.

  10. ESTIMATION OF LAND SURFACE WINDOW (8-12 MICROMETER) EMISSIVITY FROM MULTISPECTRAL THERMAL INFRARED REMOTE SENSING - A CASE STUDY IN A PART OF SAHARA DESERT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface window emissivity is an important parameter for estimating the longwave radiative budget. This study focuses on estimating the window (8-12 micrometer) emissivity from the waveband emissivities of the five thermal infrared channels of the Advanced Spaceborne Thermal Emission and Reflect...

  11. Observational Constraints on Changing Arctic Methane Emissions

    NASA Astrophysics Data System (ADS)

    Dlugokencky, E. J.; Bruhwiler, L.; Lang, P. M.; Masarie, K.; Crotwell, A. M.; Crotwell, M.; Lowry, D.; Fisher, R. E.; Nisbet, E. G.

    2012-12-01

    Methane (CH4) is the second-most important greenhouse gas influenced by human activities. Its chemistry results in additional indirect climate effects from production of tropospheric O3, which also affects air quality, and stratospheric H2O. Because methane's atmospheric lifetime is relatively short (~9 yr) and ~70% of its emissions are anthropogenic, reductions in its emissions provide a potential cost-effective opportunity to slow the rate of increase of radiative forcing. Some fraction of decreased anthropogenic emissions may be canceled by potentially strong feed-backs to natural emissions. Because natural emissions of CH4 are diffuse, relatively weak, and highly-variable in space and time, quantifying changes for large spatial regions is difficult from small-scale field studies alone. Atmosphere observations at well-chosen sites integrate these emissions over large zonal regions and can be particularly useful for detecting changes in emissions. Paleo-climate studies indicate that CH4 emissions from Arctic wetlands are sensitive to climate and may provide a strong positive feedback as the Arctic warms. Measurements of atmospheric CH4 from the NOAA Global Monitoring Division's, Global Cooperative Air Sampling Network began in 1983. These high-precision observations offer key constraints on changes in Arctic CH4 emissions. During 2007, the CH4 growth rate increased in the Arctic, but was nearly zero during 2008. Use of the data in a chemical transport model suggest anomalous emissions of about 2 Tg CH4 during 2007, but returning to long-term average emissions after that. Another potential source affected by climate is emissions from methane clathrates. Measurements of methane's isotopic composition in the Arctic have been useful in showing that CH4 enhancements in Arctic air result from wetlands, not clathrates. Both potential sources are also constrained by spatial patterns in observed CH4, which indicate that, so far, changes in emissions of Arctic CH4 over the

  12. Application of positron emission tomography (PET/CT) in diagnosis of breast cancer. Part I. Diagnosis of breast cancer prior to treatment

    PubMed Central

    Jodłowska, Elżbieta; Wyszomirska, Anna; Jarząbek, Grażyna; Kędzia, Witold; Ruchała, Marek

    2016-01-01

    Positron emission tomography with computed tomography (PET/CT) is gaining popularity as a method for overall staging assessment of breast cancer. Currently, it is not a part of the routine workup before the beginning of treatment, because of insufficient sensitivity for the detection of small tumors (due to its limited spatial resolution), the heterogeneity of radiotracer uptake by the primary tumor, and unsatisfactory sensitivity in detection of lymph node metastases (particularly when they are small). Nevertheless, it should be considered when there is a high risk of metastases, because then initial PET/CT examination allows for accurate staging and may change the treatment algorithm in up to almost 50% of stage III patients, due to detection of distant and lymph node metastases throughout the whole body. Despite the discussed limitations of PET/CT, there is ongoing research concerning the recommendations for the examination prior to treatment. For a particular group of patients with high risk of metastases, PET/CT may be expected to become a part of the routine workup as the most appropriate staging method. PMID:27095933

  13. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    NASA Astrophysics Data System (ADS)

    Jing, Boyu; Wu, Lin; Mao, Hongjun; Gong, Sunning; He, Jianjun; Zou, Chao; Song, Guohua; Li, Xiaoyu; Wu, Zhong

    2016-03-01

    This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near-real-time traffic data on road segments to develop a vehicle emission inventory with high temporal-spatial resolution (HTSVE) for the Beijing urban area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Based on the results of this study, improved air quality simulation and the contribution of vehicle emissions to ambient pollutant concentration in Beijing have been investigated in a companion paper (He et al., 2016).

  14. 40 CFR Appendix E to Part 75 - Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... correlation between heat input rate and NOX emission rate, in order to determine the emission rate of the unit... Results Tabulate the results of each baseline correlation test for each fuel or, as applicable... mixture) for which a NOX emission rate versus heat input rate correlation curve was derived, at least...

  15. Introduction of organic/hydro-organic matrices in inductively coupled plasma optical emission spectrometry and mass spectrometry: a tutorial review. Part I. Theoretical considerations.

    PubMed

    Leclercq, Amélie; Nonell, Anthony; Todolí Torró, José Luis; Bresson, Carole; Vio, Laurent; Vercouter, Thomas; Chartier, Frédéric

    2015-07-23

    Due to their outstanding analytical performances, inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are widely used for multi-elemental measurements and also for isotopic characterization in the case of ICP-MS. While most studies are carried out in aqueous matrices, applications involving organic/hydro-organic matrices become increasingly widespread. This kind of matrices is introduced in ICP based instruments when classical "matrix removal" approaches such as acid digestion or extraction procedures cannot be implemented. Due to the physico-chemical properties of organic/hydro-organic matrices and their associated effects on instrumentation and analytical performances, their introduction into ICP sources is particularly challenging and has become a full topic. In this framework, numerous theoretical and phenomenological studies of these effects have been performed in the past, mainly by ICP-OES, while recent literature is more focused on applications and associated instrumental developments. This tutorial review, divided in two parts, explores the rich literature related to the introduction of organic/hydro-organic matrices in ICP-OES and ICP-MS. The present Part I, provides theoretical considerations in connection with the physico-chemical properties of organic/hydro-organic matrices, in order to better understand the induced phenomena. This focal point is divided in four chapters highlighting: (i) the impact of organic/hydro-organic matrices from aerosol generation to atomization/excitation/ionization processes; (ii) the production of carbon molecular constituents and their spatial distribution in the plasma with respect to analytes repartition; (iii) the subsequent modifications of plasma fundamental properties; and (iv) the resulting spectroscopic and non spectroscopic interferences. This first part of this tutorial review is addressed either to beginners or to more experienced scientists who are interested in the

  16. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    NASA Astrophysics Data System (ADS)

    Jing, B. Y.; Wu, L.; Mao, H. J.; Gong, S. L.; He, J. J.; Zou, C.; Song, G. H.; Li, X. Y.; Wu, Z.

    2015-10-01

    As the ownership of vehicles and frequency of utilization increase, vehicle emissions have become an important source of air pollution in Chinese cities. An accurate emission inventory for on-road vehicles is necessary for numerical air quality simulation and the assessment of implementation strategies. This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near real time (NRT) traffic data on road segments to develop a high temporal-spatial resolution vehicle emission inventory (HTSVE) for the urban Beijing area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg, respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Additionally, the on-road vehicle emission inventory model and control effect assessment system in Beijing, a vehicle emission inventory model, was established based on this study in a companion paper (He et al., 2015).

  17. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing - Part 2: Impact of vehicle emission on urban air quality

    NASA Astrophysics Data System (ADS)

    He, J. J.; Wu, L.; Mao, H. J.; Liu, H. L.; Jing, B. Y.; Yu, Y.; Ren, P. P.; Feng, C.; Liu, X. H.

    2015-07-01

    In a companion paper (Jing et al., 2015), a high temporal-spatial resolution vehicle emission inventory (HTSVE) for 2013 in Beijing has been established based on near real time (NRT) traffic data and bottom up methodology. In this study, based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modeling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing main urban areas in the periods of summer (July) and winter (December) 2013. Generally, CUACE model had good performance of pollutants concentration simulation. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes over moment. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2, while 5.4 and 10.5 % for PM2.5 in July and December 2013, respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than PM2.5 contribution rate for vehicle emission in total emission, which may be caused by easily dry deposition of PM2.5 from vehicle emission in near-surface layer compared to elevated source emission.

  18. Space-time dynamics of carbon and environmental parameters related to carbon dioxide emissions in the Buor-Khaya Bay and adjacent part of the Laptev Sea

    NASA Astrophysics Data System (ADS)

    Semiletov, I. P.; Shakhova, N. E.; Pipko, I. I.; Pugach, S. P.; Charkin, A. N.; Dudarev, O. V.; Kosmach, D. A.; Nishino, S.

    2013-09-01

    This study aims to improve understanding of carbon cycling in the Buor-Khaya Bay (BKB) and adjacent part of the Laptev Sea by studying the inter-annual, seasonal, and meso-scale variability of carbon and related hydrological and biogeochemical parameters in the water, as well as factors controlling carbon dioxide (CO2) emission. Here we present data sets obtained on summer cruises and winter expeditions during 12 yr of investigation. Based on data analysis, we suggest that in the heterotrophic BKB area, input of terrestrially borne organic carbon (OC) varies seasonally and inter-annually and is largely determined by rates of coastal erosion and river discharge. Two different BKB sedimentation regimes were revealed: Type 1 (erosion accumulation) and Type 2 (accumulation). A Type 1 sedimentation regime occurs more often and is believed to be the quantitatively most important mechanism for suspended particular matter (SPM) and particulate organic carbon (POC) delivery to the BKB. The mean SPM concentration observed in the BKB under a Type 1 regime was one order of magnitude greater than the mean concentration of SPM (~ 20 mg L-1) observed along the Lena River stream in summer 2003. Loadings of the BKB water column with particulate material vary by more than a factor of two between the two regimes. Higher partial pressure of CO2 (pCO2), higher concentrations of nutrients, and lower levels of oxygen saturation were observed in the bottom water near the eroded coasts, implying that coastal erosion and subsequent oxidation of eroded organic matter (OM) rather than the Lena River serves as the predominant source of nutrients to the BKB. Atmospheric CO2 fluxes from the sea surface in the BKB vary from 1 to 95 mmol m-2 day-1 and are determined by specific features of hydrology and wind conditions, which change spatially, seasonally, and inter-annually. Mean values of CO2 emission from the shallow Laptev Sea were similar in September 1999 and 2005 (7.2 and 7.8 mmol m-2 day-1

  19. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 2: Impact of vehicle emission on urban air quality

    NASA Astrophysics Data System (ADS)

    He, Jianjun; Wu, Lin; Mao, Hongjun; Liu, Hongli; Jing, Boyu; Yu, Ye; Ren, Peipei; Feng, Cheng; Liu, Xuehao

    2016-03-01

    A companion paper developed a vehicle emission inventory with high temporal-spatial resolution (HTSVE) with a bottom-up methodology based on local emission factors, complemented with the widely used emission factors of COPERT model and near-real-time (NRT) traffic data on a specific road segment for 2013 in urban Beijing (Jing et al., 2016), which is used to investigate the impact of vehicle pollution on air pollution in this study. Based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modelling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing's main urban areas in the periods of summer (July) and winter (December) 2013. Generally, the CUACE model had good performance of the concentration simulation of pollutants. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes with time. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2 and 5.4 and 10.5 % for PM2.5 in July and December 2013 respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while it is 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than the PM2.5 contribution rate for vehicle emission in total emission, which may be due to dry deposition of PM2.5 from vehicle emission in the near-surface layer occuring more easily than from elevated source emission.

  20. The impact of the congestion charging scheme on air quality in London. Part 1. Emissions modeling and analysis of air pollution measurements.

    PubMed

    Kelly, Frank; Anderson, H Ross; Armstrong, Ben; Atkinson, Richard; Barratt, Ben; Beevers, Sean; Derwent, Dick; Green, David; Mudway, Ian; Wilkinson, Paul

    2011-04-01

    On February 17, 2003, a congestion charging scheme (CCS*) was introduced in central London along with a program of traffic management measures. The scheme operated Monday through Friday, 7 AM to 6 PM. This program resulted in an 18% reduction in traffic volume and a 30% reduction in traffic congestion in the first year (2003). We developed methods to evaluate the possible effects of the scheme on air quality: We used a temporal-spatial design in which modeled and measured air quality data from roadside and background monitoring stations were used to compare time periods before (2001-2002) and after (2003-2004) the CCS was introduced and to compare the spatial area of the congestion charging zone (CCZ) with the rest of London. In the first part of this project, we modeled changes in concentrations of oxides of nitrogen (NOx), nitrogen dioxide (NO2), and PM10 (particles with a mass median aerodynamic diameter < or = 10 microm) across the CCZ and in Greater London under different traffic and emission scenarios for the periods before and after CCS introduction. Comparing model results within and outside the zone suggested that introducing the CCS would be associated with a net 0.8-microg/m3 decrease in the mean concentration of PM10 and a net 1.7-ppb decrease in the mean concentration of NOx within the CCZ. In contrast, a net 0.3-ppb increase in the mean concentration of NO2 was predicted within the zone; this was partly explained by an expected increase in primary NO2 emissions due to the introduction of particle traps on diesel buses (one part of the improvements in public transport associated with the CCS). In the second part of the project, we established a CCS Study Database from measurements obtained from the London Air Quality Network (LAQN) for air pollution monitors sited to measure roadside and urban background concentrations. Fully ratified (validated) 15-minute mean carbon monoxide (CO), nitric oxide (NO), NO2, NOx, PM10, and PM2.5 data from each chosen

  1. 40 CFR Table W - 1A of Subpart W of Part 98-Default Whole Gas Emission Factors for Onshore Petroleum and Natural...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Onshore petroleum andnatural gas production Emission factor (scf/hour/component) Eastern U.S. Population... Device Vents 2 37.3 Intermittent Bleed Pneumatic Device Vents 2 13.5 Pneumatic Pumps 3 13.3 Population... Line 0.05 Pump 0.01 Other 5 0.30 Population Emission Factors—All Components, Heavy Crude Service...

  2. 40 CFR Table W - 1A of Subpart W of Part 98-Default Whole Gas Emission Factors for Onshore Petroleum and Natural...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Onshore petroleum andnatural gas production Emission factor (scf/hour/component) Eastern U.S. Population... Device Vents 2 37.3 Intermittent Bleed Pneumatic Device Vents 2 13.5 Pneumatic Pumps 3 13.3 Population... Line 0.05 Pump 0.01 Other 5 0.30 Population Emission Factors—All Components, Heavy Crude Service...

  3. The net climate impact of coal-fired power plant emissions

    NASA Astrophysics Data System (ADS)

    Shindell, D. T.; Faluvegi, G.

    2009-10-01

    Coal-fired power plants influence climate via both the emissions of long-lived carbon dioxide (CO2) and short-lived ozone and aerosol precursors. For steadily increasing emissions without substantial pollution controls, we find that the net global mean climate forcing ranges from near zero to a substantial negative value, depending on the magnitude of aerosol indirect effects, due to aerosol masking of the effects of CO2. Imposition of pollution controls on sulfur dioxide and nitrogen oxides leads to a rapid realization of the full positive forcing from CO2, however. The long-term forcing from stable (constant) emissions is positive regardless of pollution controls, with larger values in the case of pollutant controls. The results imply that historical emissions from coal-fired power plants until ~1970, including roughly 1/3 of total anthropogenic carbon dioxide emissions, likely contributed little net global mean climate forcing during that period. Those emissions likely led to weak cooling at Northern Hemisphere mid-latitudes and warming in the Southern Hemisphere, however. Subsequent imposition of pollution controls and the switch to low-sulfur coal in some areas kept global SO2 emissions roughly level from 1970 to 2000. Hence during that period, RF due to emissions during those decades and CO2 emitted previously was strongly positive and likely contributed to rapid global and regional warming. Most recently, construction of coal-fired power plants in China and India has been increasing rapidly with minimal application of pollution controls. Continuation of high-growth rates for another 30 years would lead to near zero to negative global mean climate forcing in the absence of expanded pollution controls, but severely degraded air quality. However, following the Western pattern of high coal usage followed by imposition of pollution controls could lead to accelerated global warming in the future.

  4. Effects of low concentration biodiesel blend application on modern passenger cars. Part 1: feedstock impact on regulated pollutants, fuel consumption and particle emissions.

    PubMed

    Fontaras, Georgios; Kousoulidou, Marina; Karavalakis, Georgios; Tzamkiozis, Theodoros; Pistikopoulos, Panayotis; Ntziachristos, Leonidas; Bakeas, Evangelos; Stournas, Stamoulis; Samaras, Zissis

    2010-05-01

    Five biodiesels from different feedstocks (rapeseed, soy, sunflower, palm, and used fried oils) blended with diesel at 10% vol. ratio (B10), were tested on a Euro 3 common-rail passenger car. Limited effects (-2% to +4%) were observed on CO(2) emissions. CO and HC emissions increased between 10% and 25% on average, except at high speed - high power where emissions were too low to draw conclusions. NOx emissions increased by up to 20% for two out of the five blends, decreased by up to 15% for two other blends, and remained unchanged for one blend. Particulate matter (PM) was reduced for all blends by up to 25% and the reductions were positively correlated with the extent of biodiesel saturation. PM reductions are associated with consistent reductions in non-volatile particle number. A variable behaviour in particle number is observed when volatile particles are also accounted. PMID:20080326

  5. New emission factors for Australian vegetation fires measured using open-path Fourier transform infrared spectroscopy - Part 2: Australian tropical savanna fires

    NASA Astrophysics Data System (ADS)

    Smith, T. E. L.; Paton-Walsh, C.; Meyer, C. P.; Cook, G. D.; Maier, S. W.; Russell-Smith, J.; Wooster, M. J.; Yates, C. P.

    2014-10-01

    Savanna fires contribute approximately 40-50% of total global annual biomass burning carbon emissions. Recent comparisons of emission factors from different savanna regions have highlighted the need for a regional approach to emission factor development, and better assessment of the drivers of the temporal and spatial variation in emission factors. This paper describes the results of open-path Fourier transform infrared (OP-FTIR) spectroscopic field measurements at 21 fires occurring in the tropical savannas of the Northern~Territory, Australia, within different vegetation assemblages and at different stages of the dry season. Spectra of infrared light passing through a long (22-70 m) open-path through ground-level smoke released from these fires were collected using an infrared lamp and a field-portable FTIR system. The IR spectra were used to retrieve the mole fractions of 14 different gases present within the smoke, and these measurements used to calculate the emission ratios and emission factors of the various gases emitted by the burning. Only a handful of previous emission factor measures are available specifically for the tropical savannas of Australia and here we present the first reported emission factors for methanol, acetic acid, and formic acid for this biome. Given the relatively large sample size, it was possible to study the potential causes of the within-biome variation of the derived emission factors. We find that the emission factors vary substantially between different savanna vegetation assemblages; with a majority of this variation being mirrored by variations in the modified combustion efficiency (MCE) of different vegetation classes. We conclude that a significant majority of the variation in the emission factor for trace gases can be explained by MCE, irrespective of vegetation class, as illustrated by variations in the calculated methane emission factor for different vegetation classes using data sub-set by different combustion efficiencies

  6. Dynamic evaluation of CMAQ part I: Separating the effects of changing emissions and changing meteorology on ozone levels between 2002 and 2005 in the eastern US

    NASA Astrophysics Data System (ADS)

    Foley, Kristen M.; Hogrefe, Christian; Pouliot, George; Possiel, Norm; Roselle, Shawn J.; Simon, Heather; Timin, Brian

    2015-02-01

    A dynamic evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.0.1 was conducted to evaluate the model's ability to predict changes in ozone levels between 2002 and 2005, a time period characterized by emission reductions associated with the EPA's Nitrogen Oxides State Implementation Plan as well as significant reductions in mobile source emissions. Model results for the summers of 2002 and 2005 were compared to simulations from a previous version of CMAQ to assess the impact of model updates on predicted pollutant response. Changes to the model treatment of emissions, meteorology and chemistry had substantial impacts on the simulated ozone concentrations. While the median bias for high summertime ozone decreased in both years compared to previous simulations, the observed decrease in ozone from 2002 to 2005 in the eastern US continued to be underestimated by the model. Additional "cross" simulations were used to decompose the model predicted change in ozone into the change due to emissions, the change due to meteorology and any remaining change not explained individually by these two components. The decomposition showed that the emission controls led to a decrease in modeled high summertime ozone close to twice as large as the decrease attributable to changes in meteorology alone. Quantifying the impact of retrospective emission controls by removing the impacts of meteorology during the control period can be a valuable approach for communicating to policy makers the net benefit of national control measures.

  7. New emission factors for Australian vegetation fires measured using open-path Fourier transform infrared spectroscopy - Part 2: Australian tropical savanna fires

    NASA Astrophysics Data System (ADS)

    Smith, T. E. L.; Paton-Walsh, C.; Meyer, C. P.; Cook, G. D.; Maier, S. W.; Russell-Smith, J.; Wooster, M. J.; Yates, C. P.

    2014-03-01

    Savanna fires contribute approximately 40-50% of total global annual biomass burning carbon emissions. Recent comparisons of emission factors from different savanna regions have highlighted the need for a regional approach to emission factor development, and better assessment of the drivers of the temporal and spatial variation in emission factors. This paper describes the results of open-path Fourier Transform Infrared (OP-FTIR) spectroscopic field measurements at twenty-one fires occurring in the tropical savannas of the Northern Territory, Australia, within different vegetation assemblages and at different stages of the dry season. Spectra of infrared light passing through a long (22-70 m) open-path through ground-level smoke released from these fires were collected using an infrared lamp and a field-portable FTIR system. The IR spectra were used to retrieve the mole fractions of fourteen different gases present within the smoke, and these measurements used to calculate the emission ratios and emission factors of the various gases emitted by the burning. Only a handful of previous emission factor measures are available specifically for the tropical savannas of Australia and here we present the first reported emission factors for methanol, acetic acid, and formic acid for this biome. Given the relatively large sample size, it was possible to study the potential causes of the within-biome variation of the derived emission factors. We find that the emission factors vary substantially between different savanna vegetation assemblages; with a majority of this variation being mirrored by variations in the modified combustion efficiency (MCE) of different vegetation classes. We conclude that a significant majority of the variation in the emission factor for trace gases can be explained by MCE, irrespective of vegetation class, as illustrated by variations in the calculated methane emission factor for different vegetation classes using data subsetted by different

  8. Dilution-based emissions sampling from stationary sources: part 2 - gas-fired combustors compared with other fuel-fired systems

    SciTech Connect

    England, G.C.; Watson, J.G.; Chow, J.C.; Zielinska, B.; Chang, M.C.O.; Loos, K.R.; Hidy. G.M.

    2007-01-15

    With the recent focus on fine particle matter (PM2.5), new, self- consistent data are needed to characterize emissions from combustion sources. Emissions data for gas-fired combustors are presented, using dilution sampling as the reference. The sampling and analysis of the collected particles in the presence of precursor gases, SO{sub 2}, nitrogen oxide, volatile organic compound, and NH{sub 3} is discussed; the results include data from eight gas fired units, including a dual- fuel institutional boiler and a diesel engine powered electricity generator. These data are compared with results in the literature for heavy-duty diesel vehicles and stationary sources using coal or wood as fuels. The results show that the gas-fired combustors have very low PM2.5 mass emission rates in the range of {approximately}10{sup -4} lb/million Btu (MMBTU) compared with the diesel backup generator with particle filter, with {approximately} 5 x 10{sup -3} lb/MMBTU. Even higher mass emission rates are found in coal-fired systems, with rates of {approximately} 0.07 lb/MMBTU for a bag-filter-controlled pilot unit burning eastern bituminous coal. The characterization of PM2.5 chemical composition from the gas-fired units indicates that much of the measured primary particle mass in PM2.5 samples is organic or elemental carbon and, to a much less extent, sulfate. Metal emissions are low compared with the diesel engines and the coal- or wood-fueled combustors. The metals found in the gas- fired combustor particles are low in concentration. The interpretation of the particulate carbon emissions is complicated by the fact that an approximately equal amount of particulate carbon is found on the particle collector and a backup filter. It is likely that measurement artifacts are positively biasing 'true' particulate carbon emissions results. 49 refs., 1 fig., 12 tabs.

  9. New emission factors for Australian vegetation fires measured using open-path Fourier transform infrared spectroscopy - Part 1: Methods and Australian temperate forest fires

    NASA Astrophysics Data System (ADS)

    Paton-Walsh, C.; Smith, T. E. L.; Young, E. L.; Griffith, D. W. T.; Guérette, É.-A.

    2014-10-01

    Biomass burning releases trace gases and aerosol particles that significantly affect the composition and chemistry of the atmosphere. Australia contributes approximately 8% of gross global carbon emissions from biomass burning, yet there are few previous measurements of emissions from Australian forest fires available in the literature. This paper describes the results of field measurements of trace gases emitted during hazard reduction burns in Australian temperate forests using open-path Fourier transform infrared spectroscopy. In a companion paper, similar techniques are used to characterise the emissions from hazard reduction burns in the savanna regions of the Northern Territory. Details of the experimental methods are explained, including both the measurement set-up and the analysis techniques employed. The advantages and disadvantages of different ways to estimate whole-fire emission factors are discussed and a measurement uncertainty budget is developed. Emission factors for Australian temperate forest fires are measured locally for the first time for many trace gases. Where ecosystem-relevant data are required, we recommend the following emission factors for Australian temperate forest fires (in grams of gas emitted per kilogram of dry fuel burned) which are our mean measured values: 1620 ± 160 g kg-1 of carbon dioxide; 120 ± 20 g kg-1 of carbon monoxide; 3.6 ± 1.1 g kg-1 of methane; 1.3 ± 0.3 g kg-1 of ethylene; 1.7 ± 0.4 g kg-1 of formaldehyde; 2.4 ± 1.2 g kg-1 of methanol; 3.8 ± 1.3 g kg-1 of acetic acid; 0.4 ± 0.2 g kg-1 of formic acid; 1.6 ± 0.6 g kg-1 of ammonia; 0.15 ± 0.09 g kg-1 of nitrous oxide and 0.5 ± 0.2 g kg-1 of ethane.

  10. Evaluating NOx emissions in the LA basin and their implications for O3 and NOx during CalNex-2010

    NASA Astrophysics Data System (ADS)

    Chen, D.; Li, Q.; Stutz, J.; Pikelnaya, O.; Tsai, C.; Haman, C. L.; Lefer, B. L.; Flynn, J. H.; Roberts, J. M.; De Gouw, J. A.; Holloway, J. S.; Pollack, I. B.; Ryerson, T. B.

    2011-12-01

    We evaluate NOx emissions in the Los Angeles Basin during the CalNex-2010 field campaign by analyzing O3 and NOy observations using WRF/Chem. Model simulations are conducted at 4-km spatial resolution over the basin and the results are compared against ARB surface measurements as well as CalNex surface and aircraft observations. We adjust the 2005 National Emissions Inventory (NEI'05) for the CalNex simulations with a 24% reduction in NOx and 28% reduction in CO according to the emission statistics from California ARB. WRF/Chem O3 reproduces the observed diurnal cycle and day-to-day variations in surface O3 (r2 = 0.92, n = 114, p = 0.01) across the basin. Model results underestimate daytime O3 at the CalNex-LA supersite (Caltech) by 20-40 ppbv during May 29-30 when O3 levels approached 80-100 ppbv. The underestimate is in large part because of the deeper than observed PBL heights in the model and the model's inability to simulate observed strong stratospheric intrusion that penetrated deep into the basin on May 29th (Langford et al., 2011). Titration due to excessively high NOx emissions at downtown L.A. sites leads to near-zero nighttime O3. The vertical profiles of CO below 3 km show good agreement with the observation (r2=0.64, n=576, p=0.01), but with ~90 ppb overestimation for the altitude below 400 m altitude. Model NO2 and NOy concentrations along the June 2-3 NOAA P-3 flights over the basin are biased high by 106% and 48%, respectively. Model results capture the overall variability in the LP-DOAS observed NO2 and O3 but overestimate NO2 below 500 m altitude. A 45% reduction of NOx emissions from 2005 to 2010, as implied by OMI NO2 columns (Russell et al., 2010), significantly improves model comparisons of NO2, NOy and O3 during CalNex.

  11. OBSERVABLE INDICATORS OF THE SENSITIVITY OF PM 2.5 NITRATE TO EMISSION REDUCTIONS, PART II: SENSITIVITY TO ERRORS IN TOTAL AMMONIA AND TOTAL NITRATE OF THE CMAQ-PREDICTED NONLINEAR EFFECT OF SO 2 EMISSION REDUCTIONS

    EPA Science Inventory

    The inorganic aerosol system of sulfate, nitrate, and ammonium can respond nonlinearly to changes in precursor sulfur dioxide (SO2) emissions. The potential increase in nitrate, when sulfate is reduced and the associated ammonia is released, can negate the sulfate mass...

  12. Dynamic evaluation of CMAQ part I: Separating the effects of changing emissions and changing meteorology on ozone levels between 2002 and 2005 in the eastern US

    EPA Science Inventory

    A dynamic evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.0.1 was conducted to evaluate the model's ability to predict changes in ozone levels between 2002 and 2005, a time period characterized by emission reductions associated with the EPA's N...

  13. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... an SO2 continuous emission monitoring system. Complete all testing requirements no later than the... protocol no later than 45 days after the completion of all certification tests. 2. Procedure 2.1Fuel... Turbine Meters; American Gas Association Report No. 3, Orifice Metering of Natural Gas and Other...

  14. Mercury emission from terrestrial background surfaces in the eastern USA. Part I: Air/surface exchange of mercury within a southeastern deciduous forest (Tennessee) over one year

    SciTech Connect

    Kuiken, Todd; Zhang, Hong; Gustin, Mae S.; Lindberg, Steven Eric

    2008-03-01

    This study focused on the development of a seasonal data set of the Hg air/surface exchange over soils associated with low Hg containing surfaces in a deciduous forest in the southern USA. Data were collected every month for 11 months in 2004 within Standing Stone State Forest in Tennessee using the dynamic flux chamber method. Mercury air/surface exchange associated with the litter covered forest floor was very low with the annual mean daytime flux being 0.4 0.5 ng m-2 h-1 (n = 301). The daytime Hg air/surface exchange over the year oscillated between emission (81% of samples with positive flux) and deposition (19% of samples with negative flux). A seasonal trend of lower emission in the spring and summer (closed canopy) relative to the fall and winter (open canopy) was observed. Correlations were found between the air/surface exchange and certain environmental factors on specific days sampled but not collectively over the entire year. The very low magnitude of Hg air/surface exchange as observed in this study suggests that an improved methodology for determining and reporting emission fluxes is needed when the values of fluxes and chamber blanks are both very low and comparable. This study raises questions and points to a need for more research regarding how to scale the Hg air/surface exchange for surfaces with very low emissions.

  15. Dilution-based emissions sampling from stationary sources: Part 2--Gas-fired combustors compared with other fuel-fired systems.

    PubMed

    England, Glenn C; Watson, John G; Chow, Judith C; Zielinska, Barbara; Chang, M C Oliver; Loos, Karl R; Hidy, George M

    2007-01-01

    With the recent focus on fine particle matter (PM2.5), new, self-consistent data are needed to characterize emissions from combustion sources. Such data are necessary for health assessment and air quality modeling. To address this need, emissions data for gas-fired combustors are presented here, using dilution sampling as the reference. The dilution method allows for collection of emitted particles under conditions simulating cooling and dilution during entry from the stack into the air. The sampling and analysis of the collected particles in the presence of precursor gases, SO2 nitrogen oxide, volatile organic compound, and NH3 is discussed; the results include data from eight gas fired units, including a dual-fuel institutional boiler and a diesel engine powered electricity generator. These data are compared with results in the literature for heavy-duty diesel vehicles and stationary sources using coal or wood as fuels. The results show that the gas-fired combustors have very low PM2.5 mass emission rates in the range of approximately 10(-4) lb/million Btu (MMBTU) compared with the diesel backup generator with particle filter, with approximately 5 x 10(-3) lb/MMBTU. Even higher mass emission rates are found in coal-fired systems, with rates of approximately 0.07 lb/MMBTU for a bag-filter-controlled pilot unit burning eastern bituminous coal. The characterization of PM2.5 chemical composition from the gas-fired units indicates that much of the measured primary particle mass in PM2.5 samples is organic or elemental carbon and, to a much less extent, sulfate. Metal emissions are quite low compared with the diesel engines and the coal- or wood-fueled combustors. The metals found in the gas-fired combustor particles are low in concentration, similar in concentration to ambient particles. The interpretation of the particulate carbon emissions is complicated by the fact that an approximately equal amount of particulate carbon (mainly organic carbon) is found on the

  16. Optical remote sensing to quantify fugitive particulate mass emissions from stationary short-term and mobile continuous sources: part II. Field applications.

    PubMed

    Du, Ke; Yuen, Wangki; Wang, Wei; Rood, Mark J; Varma, Ravi M; Hashmonay, Ram A; Kim, Byung J; Kemme, Michael R

    2011-01-15

    Quantification of emissions of fugitive particulate matter (PM) into the atmosphere from military training operations is of interest by the United States Department of Defense. A new range-resolved optical remote sensing (ORS) method was developed to quantify fugitive PM emissions from puff sources (i.e., artillery back blasts), ground-level mobile sources (i.e., movement of tracked vehicles), and elevated mobile sources (i.e., airborne helicopters) in desert areas that are prone to generating fugitive dust plumes. Real-time, in situ mass concentration profiles for PM mass with particle diameters <10 μm (PM(10)) and <2.5 μm (PM(2.5)) were obtained across the dust plumes that were generated by these activities with this new method. Back blasts caused during artillery firing were characterized as a stationary short-term puff source whose plumes typically dispersed to <10 m above the ground with durations of 10-30 s. Fugitive PM emissions caused by artillery back blasts were related to the zone charge and ranged from 51 to 463 g PM/firing for PM(10) and 9 to 176 g PM/firing for PM(2.5). Movement of tracked vehicles and flying helicopters was characterized as mobile continuous sources whose plumes typically dispersed 30-50 m above the ground with durations of 100-200 s. Fugitive PM emissions caused by moving tracked vehicles ranged from 8.3 to 72.5 kg PM/km for PM(10) and 1.1 to 17.2 kg PM/km for PM(2.5), and there was no obvious correlation between PM emission and vehicle speed. The emission factor for the helicopter flying at 3 m above the ground ranged from 14.5 to 114.1 kg PM/km for PM(10) and 5.0 to 39.5 kg PM/km for PM(2.5), depending on the velocity of the helicopter and type of soil it flies over. Fugitive PM emissions by an airborne helicopter were correlated with helicopter speed for a particular soil type. The results from this range-resolved ORS method were also compared with the data obtained with another path-integrated ORS method and a Flux Tower

  17. Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): part 1--major and trace element composition.

    PubMed

    Calabrese, S; D'Alessandro, W; Bellomo, S; Brusca, L; Martin, R S; Saiano, F; Parello, F

    2015-01-01

    Active biomonitoring using moss-bags was applied to an active volcanic environment for the first time. Bioaccumulation originating from atmospheric deposition was evaluated by exposing mixtures of washed and air-dried mosses (Sphagnum species) at 24 sites on Mt. Etna volcano (Italy). Concentrations of major and a large suite of trace elements were analysed by inductively coupled mass and optical spectrometry (ICP-MS and ICP-OES) after total acid digestion. Of the 49 elements analysed those which closely reflect summit volcanic emissions were S, Tl, Bi, Se, Cd, As, Cu, B, Na, Fe, Al. Enrichment factors and cluster analysis allowed clear distinction between volcanogenic, geogenic and anthropogenic inputs that affect the local atmospheric deposition. This study demonstrates that active biomonitoring with moss-bags is a suitable and robust technique for implementing inexpensive monitoring in scarcely accessible and harsh volcanic environments, giving time-averaged quantitative results of the local exposure to volcanic emissions. This task is especially important in the study area because the summit area of Mt. Etna is visited by nearly one hundred thousand tourists each year who are exposed to potentially harmful volcanic emissions. PMID:25262949

  18. Measuring ammonia emission rates from livestock buildings and manure stores—part 2: Comparative demonstrations of three methods on the farm

    NASA Astrophysics Data System (ADS)

    Dore, C. J.; Jones, B. M. R.; Scholtens, R.; Veld, J. W. H. Huis in't.; Burgess, L. R.; Phillips, V. R.

    Comparative demonstrations of three methods (flux sampling, external tracer ratio, and internal tracer ratio), were mounted in four real farm situations. A flux sampling method was demonstrated at a commercial dairy cow house (slurry-based), at a commercial piggery (straw-based), at a full-scale above-ground cylindrical slurry store (dairy cow slurry) and a full-scale earth-bank lagoon (pig slurry). An external tracer ratio method was demonstrated, in parallel with the flux sampling method, at the dairy cow house and at the above-ground slurry store. An internal tracer ratio method was demonstrated at the dairy cow house only. At the dairy cow house, the corrected emission rates from the flux sampling method and from the external tracer ratio method agreed to within the estimated experimental range, while the emission rate from the internal tracer ratio method was significantly lower. The overall conclusion of the study is that all three methods can have a useful role, the choice of which to deploy depending on the particular measurements needed in each case. The paper includes a table (No. 7) which indicates which is the recommended method when each of various considerations has top priority.

  19. Implementation of Cloud Retrievals for Tropospheric Emission Spectrometer (TES) Atmospheric Retrievals: Part 1. Description and Characterization of Errors on Trace Gas Retrievals

    NASA Technical Reports Server (NTRS)

    Kulawik, Susan S.; Worden, John; Eldering, Annmarie; Bowman, Kevin; Gunson, Michael; Osterman, Gregory B.; Zhang, Lin; Clough, Shepard A.; Shephard, Mark W.; Beer, Reinhard

    2006-01-01

    We develop an approach to estimate and characterize trace gas retrievals in the presence of clouds in high spectral measurements of upwelling radiance in the infrared spectral region (650-2260/cm). The radiance contribution of clouds is parameterized in terms of a set of frequency-dependent nonscattering optical depths and a cloud height. These cloud parameters are retrieved jointly with surface temperature, emissivity, atmospheric temperature, and trace gases such as ozone from spectral data. We demonstrate the application of this approach using data from the Tropospheric Emission Spectrometer (TES) and test data simulated with a scattering radiative transfer model. We show the value of this approach in that it results in accurate estimates of errors for trace gas retrievals, and the retrieved values improve over the initial guess for a wide range of cloud conditions. Comparisons are made between TES retrievals of ozone, temperature, and water to model fields from the Global Modeling and Assimilation Office (GMAO), temperature retrievals from the Atmospheric Infrared Sounder (AIRS), tropospheric ozone columns from the Goddard Earth Observing System (GEOS) GEOS-Chem, and ozone retrievals from the Total Ozone Mapping Spectrometer (TOMS). In each of these cases, this cloud retrieval approach does not introduce observable biases into TES retrievals.

  20. Response of carbon dioxide emissions to sheep grazing and N application in an alpine grassland - Part 2: Effect of N application

    NASA Astrophysics Data System (ADS)

    Gong, Y. M.; Mohammat, A.; Liu, X. J.; Li, K. H.; Christie, P.; Fang, F.; Song, W.; Chang, Y. H.; Han, W. X.; Lü, X. T.; Liu, Y. Y.; Hu, Y. K.

    2014-04-01

    Widespread nitrogen (N) enrichment resulting from anthropogenic activities has led to great changes in carbon exchange between the terrestrial biosphere and the atmosphere. Grassland is one of the most sensitive ecosystems to N deposition. However, the effect of N deposition on ecosystem respiration (Re) in grasslands has been conducted mainly in temperate grasslands, which are limited largely by water availability, with few studies focused on alpine grasslands that are primarily constrained by low temperatures. Failure to assess the magnitude of the response in Re outside the growing season (NGS) in previous studies also limits our understanding of carbon exchange under N deposition conditions. To address these knowledge gaps we used a combination of static closed chambers and gas chromatography in an alpine grassland from 2010 to 2011 to test the effects of N application on ecosystem respiration (Re) both inside and outside the growing season. There was no significant change in CO2 emissions under N application. Re outside the growing season was at least equivalent to 9.4% of the CO2 fluxes during the growing season (GS). Annual Re was calculated to be 279.0-403.9 g CO2 m-2 yr-1 in Bayinbuluk alpine grasslands. In addition, our results indicate that soil temperature was the dominant abiotic factor regulating variation in Re in the cold and arid environment. Our results suggest that short-term N additions exert no significant effect on CO2 emissions in alpine grassland.

  1. Response of carbon dioxide emissions to sheep grazing and N application in an alpine grassland - Part 1: Effect of sheep grazing

    NASA Astrophysics Data System (ADS)

    Gong, Y. M.; Mohammat, A.; Liu, X. J.; Li, K. H.; Christie, P.; Fang, F.; Song, W.; Chang, Y. H.; Han, W. X.; Lü, X. T.; Liu, Y. Y.; Hu, Y. K.

    2014-04-01

    Previous work has failed to address fully the response of (autotrophic and heterotrophic) respiration to grazing in different ecosystems, particularly in alpine grasslands outside the growing season. From 2010 to 2011 a field experiment combined two methods (static closed chambers and a closed dynamic soil CO2 flux system) in alpine grasslands located in the Tianshan Mountains. We examined the effects of grazing regime on ecosystem respiration (Re) both outside (NGS) and during (GS) the growing season and determined the pattern of Re in relation to climate change. There was no significant change in CO2 emissions under grazing. Heterotrophic respiration (Rh) accounted for 78.5% of Re with short-term grazing exclusion and 93.2% of Re with long-term grazing exclusion. Re, Rh and autotrophic respiration (Ra) fluxes outside the growing season were equivalent to 12.9%, 14.1% and 11.4% of the respective CO2 fluxes during the growing season. In addition, our results indicate that soil water content played a critical role in Ra in the cold and arid environment. Both Rh and Re were sensitive to soil temperature. Moreover, our results suggest that grazing exerted no significant effect on CO2 emissions in these alpine grasslands.

  2. Phosphene perception is due to the ultra-weak photon emission produced in various parts of the visual system: glutamate in the focus.

    PubMed

    Császár, Noémi; Scholkmann, Felix; Salari, Vahid; Szőke, Henrik; Bókkon, István

    2016-04-01

    Phosphenes are experienced sensations of light, when there is no light causing them. The physiological processes underlying this phenomenon are still not well understood. Previously, we proposed a novel biopsychophysical approach concerning the cause of phosphenes based on the assumption that cellular endogenous ultra-weak photon emission (UPE) is the biophysical cause leading to the sensation of phosphenes. Briefly summarized, the visual sensation of light (phosphenes) is likely to be due to the inherent perception of UPE of cells in the visual system. If the intensity of spontaneous or induced photon emission of cells in the visual system exceeds a distinct threshold, it is hypothesized that it can become a conscious light sensation. Discussing several new and previous experiments, we point out that the UPE theory of phosphenes should be really considered as a scientifically appropriate and provable mechanism to explain the physiological basis of phosphenes. In the present paper, we also present our idea that some experiments may support that the cortical phosphene lights are due to the glutamate-related excess UPE in the occipital cortex. PMID:26544101

  3. 40 CFR Table W - 6 of Subpart W of Part 98-Default Methane Emission Factors for LNG Import and Export Equipment

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Petroleum and Natural Gas Systems Definitions. Pt. 98, Subpt. W, Table W-6 Table W-6 of Subpart W of Part 98..., Gas Service Vapor Recovery Compressor 2 4.17 1 “Other” equipment type should be applied for...

  4. 40 CFR Table W - 6 of Subpart W of Part 98-Default Methane Emission Factors for LNG Import and Export Equipment

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Petroleum and Natural Gas Systems Definitions. Pt. 98, Subpt. W, Table W-6 Table W-6 of Subpart W of Part 98..., Gas Service Vapor Recovery Compressor 2 4.17 1 “Other” equipment type should be applied for...

  5. Electron emission from single-electron capture with simultaneous single-ionization reactions in 30-keV/u He{sup 2+}-on-argon collisions

    SciTech Connect

    Ma, X.; Zhang, S. F.; Zhu, X. L.; Feng, W. T.; Li, B.; Liu, H. P.; Zhang, R. T.; Guo, D. L.; Yan, S. C.; Zhang, P. J.; Wang, Q.; Li, C. Y.; Wang, J. G.

    2011-05-15

    Electron emission from the single-electron capture with simultaneous single ionization in 30 keV/u He{sup 2+} on argon was investigated using a reaction microscope, providing the electron energy spectra and momentum distributions. Intensive peaks for electrons with near-zero kinetic energies have been observed. It is demonstrated that mechanisms contributing to the electron emission include direct transfer ionization (DTI), double-electron capture with autoionization (DECA), and single-electron capture with autoionization (SECA) of target. Comparison of resonance energies shows that Ar{sup +} ions in SECA decay mainly through the 3s3p{sup 5}3d states by emitting Auger electrons, and He** in DECA decay through the 2l2l' states. The dependence of electron emission on the transverse momentum exchange has been studied. In the transfer ionization channel studied here, the DTI process dominates the electron emission, and no saddle point electron mechanism has been found.

  6. A new model for the global biogeochemical cycle of carbonyl sulfide - Part 1: Assessment of direct marine emissions with an oceanic general circulation and biogeochemistry model

    NASA Astrophysics Data System (ADS)

    Launois, T.; Belviso, S.; Bopp, L.; Fichot, C. G.; Peylin, P.

    2015-03-01

    The global budget of tropospheric carbonyl sulfide (OCS) is believed to be at equilibrium because background air concentrations have remained roughly stable over at least the last decade. Since the uptake of OCS by leaves (associated with photosynthesis) and soils have been revised significantly upwards recently, an equilibrated budget can only be obtained with a compensatory source of OCS. It has been assumed that the missing source of OCS comes from the low-latitude ocean, following the incident solar flux. The present work uses parameterizations of major production and removal processes of organic compounds in the NEMO-PISCES (Nucleus for European Modelling of the Ocean, Pelagic Interaction Scheme for Carbon and Ecosystem Studies) ocean general circulation and biogeochemistry model to assess the marine source of OCS. In addition, the OCS photo-production rates computed with the NEMO-PISCES model~were evaluated independently using the UV absorption coefficient of chromophoric dissolved organic matter (derived from satellite ocean color data) and apparent quantum yields available in the literature. Our simulations show global direct marine emissions of OCS in the range of 573-3997 GgS yr-1, depending mostly on the quantification of the absorption rate of chromophoric dissolved organic matter. The high estimates of that range are unlikely, as they correspond to a formulation that most likely overestimate photo-production process. Low and medium (813 GgS yr-1) estimates derived from the NEMO-PISCES model are however consistent spatially and temporally~with the suggested missing source of Berry et al. (2013), allowing us thus to close the global budget of OCS given the recent estimates of leaf and soil OCS uptake.

  7. A new model for the global biogeochemical cycle of carbonyl sulfide - Part 1: Assessment of direct marine emissions with an oceanic general circulation and biogeochemistry model

    NASA Astrophysics Data System (ADS)

    Launois, T.; Belviso, S.; Bopp, L.; Fichot, C. G.; Peylin, P.

    2014-08-01

    The global budget of tropospheric carbonyl sulfide (OCS) is believed to be at equilibrium because background air concentrations have remained roughly stable over at least the last decade. Since the uptakes of OCS by leaves (associated to photosynthesis) and soils have been revised significantly upwards recently, an equilibrated budget can only be obtained with a compensatory source of OCS. It has been assumed that the missing source of OCS comes from the low latitude ocean, following the incident solar flux. The present work uses parameterizations of major production and removal processes of organic compounds in the NEMO-PISCES Ocean General Circulation and Biogeochemistry Model to assess the marine source of OCS. In addition, the OCS photo-production rates computed with the NEMO-PISCES model were evaluated independently using UV absorption coefficient of chromophoric dissolved organic matter (derived from satellite ocean color) and apparent quantum yields available in the literature. Our simulations show global direct marine emissions of COS in the range of 573-3997 Gg S yr-1, depending mostly on the quantification of the absorption rate of chromophoric dissolved organic matter. The high estimates on that range are unlikely, as they correspond to a formulation that most likely overestimate photo-production process. Low and medium (813 Gg S yr-1) estimates derived from the NEMO-PISCES model are however consistent spatially and temporally with the suggested missing source of Berry et al. (2013), allowing thus to close the global budget of OCS given the recent estimates of leaf and soil OCS uptakes.

  8. ROANOKE WOODSTOVE EMISSION TESTS

    EPA Science Inventory

    The report discusses a project, part of the Integrated Air Cancer Project Roanoke study, that characterizes and quantifies emissions generated by burning authentic Roanoke cordwood. The burning occurred in a controlled laboratory setting using two woodstoves, each operated at two...

  9. U.S. broiler housing ammonia emissions inventory

    NASA Astrophysics Data System (ADS)

    Gates, R. S.; Casey, K. D.; Wheeler, E. F.; Xin, H.; Pescatore, A. J.

    Using recently published baseline ammonia emissions data for U.S. broiler chicken housing, we present a method of estimating their contribution to an annual ammonia budget that is different from that used by USEPA. Emission rate increases in a linear relationship with flock age from near zero at the start of the flock to a maximum at the end of the flock, 28-65 days later. Market weight of chickens raised for meat varies from "broilers" weighing about 2 kg to "roasters" weighing about 3 kg. Multiple flocks of birds are grown in a single house annually, with variable downtime to prepare the house between flocks. The method takes into account weight and number of chickens marketed. Uncertainty in baseline emissions estimates is used so that inventory estimates are provided with error estimates. The method also incorporates the condition of litter that birds are raised upon and the varying market weight of birds grown. Using 2003 USDA data on broiler production numbers, broiler housing is estimated to contribute 8.8-11.7 kT ammonia for new and built-up litter, respectively, in Kentucky and 240-324 kT ammonia for new and built-up litter, respectively, nationally. Results suggest that a 10% uncertainty in annual emission rate is expected for the market weight categories of broilers, heavy broilers, and roasters. A 27-47% reduction in annual housing emission rate is predicted if new rather than built-up litter were used for every flock. The estimating method can be adapted to other meat bird building emissions and future ammonia emission strategies, with suitable insertion of an age-dependent emission factor or slope into a predictive model equation. The method can be readily applied and is an alternative to that used by USEPA.

  10. 40 CFR 61.183 - Emission monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR part 60. (2) Comply with the provisions of § 60.13(d) of 40 CFR part 60. (3) Except for system...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.183 Emission monitoring....

  11. 40 CFR 61.183 - Emission monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR part 60. (2) Comply with the provisions of § 60.13(d) of 40 CFR part 60. (3) Except for system...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.183 Emission monitoring....

  12. 40 CFR 61.183 - Emission monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR part 60. (2) Comply with the provisions of § 60.13(d) of 40 CFR part 60. (3) Except for system...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.183 Emission monitoring....

  13. 40 CFR 61.183 - Emission monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR part 60. (2) Comply with the provisions of § 60.13(d) of 40 CFR part 60. (3) Except for system...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.183 Emission monitoring....

  14. High Altitude Emissions

    NASA Technical Reports Server (NTRS)

    Bulzan, Dan

    2007-01-01

    An overview of emissions related research being conducted as part of the Fundamental Aeronautics Supersonics Project is presented. The overview includes project objectives, milestones, and descriptions of major research areas. The overview also includes information on the emissions research being conducted under NASA Research Announcements. Technical challenges include: 1) Environmental impact of supersonic cruise emissions is greater due to higher flight altitudes which makes emissions reduction increasingly important. 2) Accurate prediction tools to enable combustor designs that reduce emissions at supersonic cruise are needed as well as intelligent systems to minimize emissions. 3) Combustor operating conditions at supersonic cruise are different than at subsonic cruise since inlet fuel and air temperatures are considerably increased.

  15. Emission of oxygenated volatile organic compounds (OVOCs) during the aerobic decomposition of orange wastes.

    PubMed

    Wu, Ting; Wang, Xinming

    2015-07-01

    Oxygenated volatile organic compounds (OVOCs) emitted from orange wastes during aerobic decomposition were investigated in a laboratory-controlled incubator for a period of two months. Emission of total OVOCs (TOVOCs) from orange wastes reached 1714 mg/dry kg (330 mg/wet kg). Ethanol, methanol, ethyl acetate, methyl acetate, 2-butanone and acetaldehyde were the most abundant OVOC species with shares of 26.9%, 24.8%, 20.3%, 13.9%, 2.8% and 2.5%, respectively, in the TOVOCs released. The emission fluxes of the above top five OVOCs were quite trivial in the beginning but increased sharply to form one "peak emission window" with maximums at days 1-8 until leveling off after 10 days. This type of "peak emission window" was synchronized with the CO2 fluxes and incubation temperature of the orange wastes, indicating that released OVOCs were mainly derived from secondary metabolites of orange substrates through biotic processes rather than abiotic processes or primary volatilization of the inherent pool in oranges. Acetaldehyde instead had emission fluxes decreasing sharply from its initial maximum to nearly zero in about four days, suggesting that it was inherent rather than secondarily formed. For TOVOCs or all OVOC species except 2-butanone and acetone, over 80% of their emissions occurred during the first week, implying that organic wastes might give off a considerable amount of OVOCs during the early disposal period under aerobic conditions. PMID:26141879

  16. Emissions of an AVCO Lycoming 0-320-DIAD air cooled light aircraft engine as a function of fuel-air ratio, timing, and air temperature and humidity

    NASA Technical Reports Server (NTRS)

    Meng, P. R.; Skorobatckyi, M.; Cosgrove, D. V.; Kempke, E. E., Jr.

    1976-01-01

    A carbureted aircraft engine was operated over a range of test conditions to establish the exhaust levels over the EPA seven-mode emissions cycle. Baseline (full rich production limit) exhaust emissions at an induction air temperature of 59 F and near zero relative humidity were 90 percent of the EPA standard for HC, 35 percent for NOx, and 161 percent for CO. Changes in ignition timing around the standard 25 deg BTDC from 30 deg BTDC to 20 deg BTDC had little effect on the exhaust emissions. Retarding the timing to 15 deg BTDC increased both the HC and CO emissions and decreased NOx emissions. HC and CO emissions decreased as the carburetor was leaned out, while NOx emissions increased. The EPA emission standards were marginally achieved at two leanout conditions. Variations in the quantity of cooling air flow over the engine had no effect on exhaust emissions. Temperature-humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased.

  17. Computer controlled techniques for high emission density mapping of thermionic cathodes

    NASA Astrophysics Data System (ADS)

    Gibson, J. W.; Thomas, R. E.

    1985-12-01

    Some of the techniques commonly used (e.g. SLEEP and thermionic emission microscope) for measuring emission or work function uniformity of thermionic cathode surfaces require the use of very low or near zero current densities, thus the cathode is characterized at current densities and temperatures much lower than that of a normally operating cathode. The system reported on here uses a high voltage pulse technique and is capable of measuring emission densities in the range 1 to 80 A/cm 2 at normal cathode operating temperatures. The cathode surface is scanned with an anode having a 0.025 mm aperture whose position is controlled by computer operated stepping motors. The current through the aperture to a collector electrode is measured using a sample-and-hold amplifier. Pulsing and sampling are computer synchronized with the scanning, and data for each pulse are accumulated and can be processed and displayed in several ways using the computer, including a detailed "three-dimensional" map of either the electron emission density or work function variations. The entire surface of the cathode or any portion of it can be mapped in steps as small as 0.001 mm (1μm), but typically steps of 5-100 μm were used. Measurements are presented illustrating the uniformity or nonuniformity of the electron emission densities and work functions for type-B and type-M cathodes.

  18. TREATMENT PERFORMANCE OF A COMBINED CONSTRUCTED WETLAND SYSTEM AND ITS GREENHOUSE GASES EMISSION

    NASA Astrophysics Data System (ADS)

    Xu, K. Q.; Liu, C.; Ebie, Y.; Inamori, Y.

    2009-12-01

    Constructed wetlands (CWs) can be classified into three typical types: Vertical flow (VF), Free-water Surface (FWS) and Subsurface Flow (SF) CWs according to their structures and directions of water flow. A combined FWS-VF-SFS CW system was designed and built to promote its treatment performance for actual domestic wastewater and reduce greenhouse gas emissions. The results from the pilot-scale combined system indicated that comparatively good performance for pollutant removal, which was 98.5%, 95.9%, 93.2% and 90.7% for BOD5, SS, NH4-N and TP under 6-day HRT, respectively. It was also found that the N2O emission was mainly from the VF unit of the system, which accounted for more than 80% of the total emission, whereas N2O emission from the FWS unit was nearly zero. On the other hand, the CH4 emission was not so high as N2O in the combined CW system, which mainly emitted from the FWS and SF units.

  19. Iron and helium emission lines in classical T Tauri stars

    NASA Astrophysics Data System (ADS)

    Beristain, Georgina

    Results are presented for the He emission in 31 CTTS from the Taurus-Auriga molecular cloud spanning two orders of magnitude in the mass accretion rate, and for the Fe emission in DR Tau, based on a series of high resolution echelle spectra. The He lines admit a description in terms of a narrow component ( NC) and a broad component (BC). The NC has FWHM between 32-55 km/s and centroid velocities near zero km/s or moderately redshifted, consistent with an origin in the postshock region of the magnetospheric accretion model. The BC, with FWHM between 128 and 287 km/s and centroid velocities between -93 and +35 km/s, includes a wind and an accretion component; we argue the BC is predominantly formed in the wind. Estimates of the wind and accretion component equivalent widths are oppositely related to the NC, so the NC equivalent width increases with the accretion component but decreases as the wind component increases. The NC is undetectable where profiles appear dominated by the wind, requiring a source of veiling other than the accretion shock to account for the observed continuum excess. Intensity ratios indicate that physical conditions are nearly uniform in the NC but span a range in the BC. For DR Tau, the range of morphologies in 62 unblended Fe I and Fe II lines can be resolved in terms of a narrow component (NC) that dominates the weakest lines, and a broad component (BC) that dominates the strongest lines. The (NC) has FWHM ~20 km/s and centroid velocity near zero km/s. The (BC) has FWHM ~100 km/s, and a tendency to be blueshifted by <=10 km/s. Estimates of iron line opacities τ and column densities N yield τNC ~ 3 × τBC, NFeI >~ 1017 - 1018 cm-2 , and NFeII >~ 1018 - 1019 cm-2 for the BC. Estimates of kinetic temperature for iron suggest that the NC gas is hotter than the BC by several thousand degrees. For iron, the NC is consistent with an origin in the postshock gas while the BC may originate in the inner accretion disk close to the corotation radius.

  20. Empirical Confirmation of the Critical Level for Zero and Near Zero Background Measurements

    SciTech Connect

    Hickman, D P; Simpson, T

    2001-06-01

    The alpha spectroscopy system of the Lawrence Livermore National Laboratory, Hazards Control Department evaluates electroplated samples, typically urine and feces, for alpha emitting radionuclides. Most of the samples processed by the alpha spectroscopy system are evaluated for Plutonium-239 (Pu-239), an important radionuclide used in research. This paper evaluates the Pu-239 background response of the Lawrence Livermore National Laboratory Hazards Control Department's alpha spectroscopy system. Background measurements of the alpha spectroscopy system have been studied to determine an appropriate method for establishing the a postori critical level for detection of plutonium alpha activity. Several methods of establishing the 95% confidence interval for over 4,900 background measurements were evaluated. Two methods appear to provide reasonable results so as to assure an appropriate 95% confidence interval. This report provides the results of this evaluation and the comparison of the various methods tested to establish an empirical evaluation of the critical level using a commercially available analysis program.

  1. Near zero coefficient of thermal expansion of beta-eucryptite without microcracking

    SciTech Connect

    Reimanis, Ivar; Ramalingam, Subramanian

    2015-06-16

    The present invention is drawn to a lithia alumina silica material that exhibits a low CTE over a broad temperature range and a method of making the same. The low CTE of the material allows for a decrease in microcracking within the material.

  2. Wireless power transmission for biomedical implants: The role of near-zero threshold CMOS rectifiers.

    PubMed

    Mohammadi, Ali; Redoute, Jean-Michel; Yuce, Mehmet R

    2015-01-01

    Biomedical implants require an electronic power conditioning circuitry to provide a stable electrical power supply. The efficiency of wireless power transmission is strongly dependent on the power conditioning circuitry specifically the rectifier. A cross-connected CMOS bridge rectifier is implemented to demonstrate the impact of thresholds of rectifiers on wireless power transfer. The performance of the proposed rectifier is experimentally compared with a conventional Schottky diode full wave rectifier over 9 cm distance of air and tissue medium between the transmitter and receiver. The output voltage generated by the CMOS rectifier across a 1 KΩ resistive load is around twice as much as the Schottky rectifier. PMID:26737525

  3. DOE Zero Energy Ready Home Case Study: Near Zero Maine Home II - Vassalboro, Maine

    SciTech Connect

    none,

    2014-11-01

    This case study describes a DOE Zero Energy Ready home in Vassalboro, Maine, that scored HERS 35 without PV and HERS 11 with PV. This 1,200 ft2 home has 10.5-inch-thick double-walls with 3 layers of mineral wool batt insulation, an R-20 insulated slab, R-70 cellulose in the attic, extensive air sealing, a mini-split heat pump, an heat recovery ventilator, solar water heating, LED lighting, 3.9 kWh PV, and triple-pane windows.

  4. Air-Source Integrated Heat Pump for Near-Zero Energy Houses: Technology Status Report

    SciTech Connect

    Murphy, Richard W; Rice, C Keith; Baxter, Van D; Craddick, William G

    2007-07-01

    This report documents the development of an air-source integrated heat pump (AS-IHP) through the third quarter of FY2007. It describes the design, analyses and testing of the AS-IHP, and provides performance specifications for a field test prototype and proposed control strategy. The results obtained so far continue to support the AS-IHP being a promising candidate to meet the energy service needs for DOE's development of a Zero Energy Home (ZEH) by the year 2020.

  5. Singularity-driven second- and third-harmonic generation at {epsilon}-near-zero crossing points

    SciTech Connect

    Vincenti, M. A.; Ceglia, D. de; Ciattoni, A.; Scalora, M.

    2011-12-15

    We show an alternative path to efficient second- and third-harmonic generation in proximity of the zero crossing points of the dielectric permittivity in conjunction with low absorption. Under these circumstances, any material, either natural or artificial, will show similar degrees of field enhancement followed by strong harmonic generation, without resorting to any resonant mechanism. The results presented in this paper provide a general demonstration of the potential that the zero-crossing-point condition holds for nonlinear optical phenomena. We investigate a generic Lorentz medium and demonstrate that a singularity-driven enhancement of the electric field may be achieved even in extremely thin layers of material. We also discuss the role of nonlinear surface sources in a realistic scenario where a 20-nm layer of CaF{sub 2} is excited at 21 {mu}m, where {epsilon}{approx} 0. Finally, we show similar behavior in an artificial composite material that includes absorbing dyes in the visible range, provide a general tool for the improvement of harmonic generation using the {epsilon}{approx} 0 condition, and illustrate that this singularity-driven enhancement of the field lowers the thresholds for a plethora of nonlinear optical phenomena.

  6. Surface magnetic behavior of nearly zero magnetostrictive Co-rich amorphous microwires

    NASA Astrophysics Data System (ADS)

    González, J.; Chizhik, A.; Zhukov, A.; Blanco, J. M.

    2003-03-01

    Investigations on the magnetic reversal in amorphous wire (diameter 125 μm) of nominal composition (Co 94Fe 6) 72.5Si 12.5B 15 and glass-covered microwires (diameter around 20 μm) of nominal composition (Co 1- xMn x) 75Si 10B 15 (0.07< x<0.11) using transverse and longitudinal magneto-optical Kerr effect are reported. Changes of the surface magnetic behavior of the amorphous wire after annealing (without and under torsion stress) have been studied. The analysis of the obtained results allows to establish that the outer shell of the as-quenched wire consists of circular bamboo domains, in contrast to the annealed wire displaying the existence of domain structure with magnetization directed along the wire axis. Such modification of the domain structure with the thermal treatment could be related to the change of the sign of magnetostriction from negative to positive. The effect of a thermal treatment under torsion stress (torsion annealing) on the shape of the hysteresis loop of the amorphous wire has been also investigated. The Kerr effect measurements of Co-rich microwires with different content in Mn demonstrate the variety of the shape of magnetization reversal loop, which similarly can be attributed to the change of sign and value of the magnetostriction. The rectangular shape of the hysteresis loop in circular magnetic field of the microwire with x=0.07 can be interpreted by considering that the magnetization process takes place by large Barkhausen jumps of circular domain structure, while the rectangular shape of the hysteresis loop with axial magnetic field of the microwire x=0.11 could be connected to large Barkhausen jumps inside the axial domain structure.

  7. Development of a rapid cure polydimethylsiloxane replication process with near-zero shrinkage

    NASA Astrophysics Data System (ADS)

    Badshah, Mohsin Ali; Jang, Hyungjun; Kim, Young Kyu; Kim, Tae-Hyoung; Kim, Seok-min

    2014-07-01

    Replicated polydimethylsiloxane (PDMS) micro/nanostructures are widely used in various research fields due to their inexpensiveness, flexibility, low surface energy, good optical properties, biocompatibility, chemical inertness, high durability, and easy fabrication process. However, the application of PDMS micro/nanostructures is limited when an accurate pattern shape or position is required because of the shrinkage that occurs during the PDMS curing process. In this study, we analyzed the effects of processing parameters in the PDMS replication process on the shrinkage of the final structure. Although the shrinkage can be decreased by decreasing the curing temperature, this reduction also increases the unnecessary curing time. To minimize the inherent shrinkage in the PDMS replica without an accompanying curing time increase, we propose a PDMS replication process on a high modulus substrate (glass and polymer films) with compression pressure, in which the adhesion force between the substrate and the PDMS, and the compression pressure prevent shrinkage during the curing process. Using the proposed method, a PDMS replica with less than 0.1% in-plane and vertical shrinkage was obtained at a curing temperature of 150°C and a curing time of 10 min.

  8. Ground-Source Integrated Heat Pump for Near-Zero Energy Houses: Technology Status Report

    SciTech Connect

    Murphy, Richard W; Rice, C Keith; Baxter, Van D; Craddick, William G

    2007-09-01

    The energy service needs of a net-zero-energy house (ZEH) include space heating and cooling, water heating, ventilation, dehumidification, and humidification, depending on the requirements of the specific location. These requirements differ in significant ways from those of current housing. For instance, the most recent DOE buildings energy data (DOE/BED 2007) indicate that on average {approx}43% of residential buildings primary energy use is for space heating and cooling, vs. {approx}12% for water heating (about a 3.6:1 ratio). In contrast, for the particular prototype ZEH structures used in the analyses in this report, that ratio ranges from about 0.3:1 to 1.6:1 depending on location. The high-performance envelope of a ZEH results in much lower space heating and cooling loads relative to current housing and also makes the house sufficiently air-tight to require mechanical ventilation for indoor air quality. These envelope characteristics mean that the space conditioning load will be closer in size to the water heating load, which depends on occupant behavior and thus is not expected to drop by any significant amount because of an improved envelope. In some locations such as the Gulf Coast area, additional dehumidification will almost certainly be required during the shoulder and cooling seasons. In locales with heavy space heating needs, supplemental humidification may be needed because of health concerns or may be desired for improved occupant comfort. The U.S. Department of Energy (DOE) has determined that achieving their ZEH goal will require energy service equipment that can meet these needs while using 50% less energy than current equipment. One promising approach to meeting this requirement is through an integrated heat pump (IHP) - a single system based on heat pumping technology. The energy benefits of an IHP stem from the ability to utilize otherwise wasted energy; for example, heat rejected by the space cooling operation can be used for water heating. With the greater energy savings the cost of the more energy efficient components required for the IHP can be recovered more quickly than if they were applied to individual pieces of equipment to meet each individual energy service need. An IHP can be designed to use either outdoor air or geothermal resources (e.g., ground, ground water, surface water) as the environmental energy source/sink. Based on a scoping study of a wide variety of possible approaches to meeting the energy service needs for a ZEH, DOE selected the IHP concept as the most promising and has supported research directed toward the development of both air- and ground-source versions. This report describes the ground-source IHP (GS-IHP) design and includes the lessons learned and best practices revealed by the research and development (R&D) effort throughout. Salient features of the GS-IHP include a variable-speed rotary compressor incorporating a brushless direct current permanent magnet motor which provides all refrigerant compression, a variable-speed fan for the indoor section, a multiple-speed ground coil circuit pump, and a single-speed pump for water heating operation. Laboratory IHP testing has thus far used R-22 because of the availability of the needed components that use this refrigerant. It is expected that HFC R-410A will be used for any products arising from the IHP concept. Data for a variable-speed compressor that uses R-410A has been incorporated into the DOE/ORNL Mark VI Heat Pump Design Model (HPDM). HPDM was then linked to TRNSYS, a time-series-dependent simulation model capable of determining the energy use of building cooling and heating equipment as applied to a defined house on a sub-hourly basis. This provided a highly flexible design analysis capability for advanced heat pump equipment; however, the program also took a relatively long time to run. This approach was used with the initial prototype design reported in Murphy et al. (2007a) and in the business case analysis of Baxter (2007).

  9. Asymmetric acoustic transmission through near-zero-index and gradient-index metasurfaces

    NASA Astrophysics Data System (ADS)

    Shen, Chen; Xie, Yangbo; Li, Junfei; Cummer, Steven A.; Jing, Yun

    2016-05-01

    We present a design of acoustic metasurfaces yielding asymmetric transmission within a certain frequency band. The design consists of a layer of gradient-index metasurface and a layer of low refractive index metasurface. Incident waves are controlled in a wave vector dependent manner to create strong asymmetric transmission. Numerical simulations show that the approach provides high transmission contrast between the two incident directions within the designed frequency band. This is further verified by experiments. Compared to previous designs, the proposed approach yields a compact and planar device. Our design may find applications in various scenarios such as noise control and therapeutic ultrasound.

  10. 40 CFR 61.163 - Emission monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements and procedures contained in Performance Specification 1 of appendix B of 40 CFR part 60. (c...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic...

  11. 40 CFR 61.163 - Emission monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements and procedures contained in Performance Specification 1 of appendix B of 40 CFR part 60. (c...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic...

  12. 40 CFR 61.163 - Emission monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements and procedures contained in Performance Specification 1 of appendix B of 40 CFR part 60. (c...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic...

  13. 40 CFR 61.163 - Emission monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements and procedures contained in Performance Specification 1 of appendix B of 40 CFR part 60. (c...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic...

  14. OBSERVABLE INDICATORS OF THE SENSITIVITY OF PM2.5 NITRATE TO EMISSION REDUCTIONS PART I: DERIVATION OF THE ADJUSTED GAS RATIO AND APPLICABILITY AT REGULATORY-RELEVANT TIME SCALES

    EPA Science Inventory

    Chemical transport models have frequently been used to evaluate the impacts of emission reductions on inorganic PM2.5. However, such models are limited in their accuracy by uncertain estimates of the spatial and temporal characterization of emissions and meteorology. Site-speci...

  15. Emission properties of explosive field emission cathodes

    SciTech Connect

    Roy, Amitava; Patel, Ankur; Menon, Rakhee; Sharma, Archana; Chakravarthy, D. P.; Patil, D. S.

    2011-10-15

    The research results of the explosive field emission cathode plasma expansion velocity and the initial emission area in the planar diode configuration with cathodes made of graphite, stainless steel, polymer velvet, carbon coated, and carbon fiber (needle type) cathodes are presented. The experiments have been performed at the electron accelerator LIA-200 (200 kV, 100 ns, and 4 kA). The diode voltage has been varied from 28-225 kV, whereas the current density has been varied from 86-928 A/cm{sup 2} with 100 ns pulse duration. The experimentally obtained electron beam diode perveance has been compared with the 1 dimensional Child-Langmuir- law. It was found that initially only a part of the cathode take part in the emission process. The plasma expands at 1.7-5.2 cm/{mu}s for 4 mm anode-cathode gap for various cathode materials. It was found that the plasma expansion velocity increases with the decrease in the cathode diameter. At the beginning of the accelerating pulse, the entire cathode area participates in the electron emission process only for the multiple needle type carbon fiber cathode.

  16. Feasibility of including fugitive PM-10 emissions estimates in the EPA emissions trends report

    SciTech Connect

    Barnard, W.; Carlson, P.

    1990-09-01

    The report describes the results of Part 2 of a two part study. Part 2 was to evaluate the feasibility of developing regional emission trends for PM-10. Part 1 was to evaluate the feasibility of developing VOC emission trends, on a regional and temporal basis. These studies are part of the effort underway to improve the national emission trends. Part 1 is presented in a separate report. The categories evaluated for the feasibility of developing regional emissions estimates were: unpaved roads, paved roads, wind erosion, agricultural tilling, construction activities, feedlots, burning, landfills, mining and quarrying unpaved parking lots, unpaved airstrips and storage piles.

  17. Influence of Jet Fuel Composition on Aircraft Engine Emissions: A Synthesis of Aerosol Emissions Data from the NASA APEX, AAFEX, and ACCESS Missions

    NASA Astrophysics Data System (ADS)

    Moore, R.; Shook, M.; Beyersdorf, A. J.; Corr, C.; Herndon, S. C.; Knighton, W. B.; Miake-Lye, R. C.; Thornhill, K. L., II; Winstead, E.; Yu, Z.; Ziemba, L. D.; Anderson, B. E.

    2015-12-01

    We statistically analyze the impact of jet fuel properties on aerosols emitted by the NASA McDonnell Douglas DC-8 CFM56-2-C1 engines burning fifteen different aviation fuels. Data were collected for this single engine type during four different, comprehensive ground tests conducted over the past decade, which allow us to clearly link changes in aerosol emissions to fuel compositional changes. It is found that the volatile aerosol fraction dominates the number and volume emissions indices (EIs) over all engine powers, which are driven by changes in fuel aromatic and sulfur content. Meanwhile, the naphthalenic content of the fuel determines the magnitude of the non-volatile number and volume EI as well as the black carbon mass EI. Linear regression coefficients are reported for each aerosol EI in terms of these properties, engine fuel flow rate, and ambient temperature, and show that reducing both fuel sulfur content and napththalenes to near-zero levels would result in roughly a ten-fold decrease in aerosol number emitted per kg of fuel burn. This work informs future efforts to model aircraft emissions changes as the aviation fleet gradually begins to transition toward low-aromatic, low-sulfur alternative jet fuels from bio-based or Fischer-Tropsch production pathways.

  18. NATIONAL EMISSIONS INVENTORY

    EPA Science Inventory

    The National Emisssions Inventory (NEI) is a data base containing estimates of air pollutant emissions in every US county for the years 1990-2002. National estimates back to 1970 are also part of the NEI. Access to NEI data is available from the following products and services:...

  19. Climate policy: Reforming emissions trading

    NASA Astrophysics Data System (ADS)

    Edenhofer, Ottmar

    2014-08-01

    Courageous steps are required to reform the European Union Emissions Trading Scheme. To this end, an independent carbon authority has been proposed -- this is a move in the right direction, but should be part of a much broader discussion about reforming emissions trading.

  20. Controlling air emissions from incinerators

    SciTech Connect

    Foisy, M.B.; Li, R.; Chattapadhyay, A.

    1994-04-01

    Last year, EPA published final rules establishing technical standards for the use and disposal of wastewater biosolids (40 CFR, Part 503). Subpart E specifically regulates the operations of and emissions from municipal wastewater biosolids incinerators.

  1. Soil greenhouse gas emissions and carbon budgeting in a short-hydroperiod floodplain wetland

    USGS Publications Warehouse

    Batson, Jackie; Noe, Gregory B.; Hupp, Cliff R.; Krauss, Ken W.; Rybicki, Nancy B.; Schenk, Edward R.

    2015-01-01

    Understanding the controls on floodplain carbon (C) cycling is important for assessing greenhouse gas emissions and the potential for C sequestration in river-floodplain ecosystems. We hypothesized that greater hydrologic connectivity would increase C inputs to floodplains that would not only stimulate soil C gas emissions but also sequester more C in soils. In an urban Piedmont river (151 km2 watershed) with a floodplain that is dry most of the year, we quantified soil CO2, CH4, and N2O net emissions along gradients of floodplain hydrologic connectivity, identified controls on soil aerobic and anaerobic respiration, and developed a floodplain soil C budget. Sites were chosen along a longitudinal river gradient and across lateral floodplain geomorphic units (levee, backswamp, and toe slope). CO2 emissions decreased downstream in backswamps and toe slopes and were high on the levees. CH4 and N2O fluxes were near zero; however, CH4emissions were highest in the backswamp. Annual CO2 emissions correlated negatively with soil water-filled pore space and positively with variables related to drier, coarser soil. Conversely, annual CH4 emissions had the opposite pattern of CO2. Spatial variation in aerobic and anaerobic respiration was thus controlled by oxygen availability but was not related to C inputs from sedimentation or vegetation. The annual mean soil CO2 emission rate was 1091 g C m−2 yr−1, the net sedimentation rate was 111 g C m−2 yr−1, and the vegetation production rate was 240 g C m−2 yr−1, with a soil C balance (loss) of −338 g C m−2 yr−1. This floodplain is losing C likely due to long-term drying from watershed urbanization.

  2. Soil greenhouse gas emissions and carbon budgeting in a short-hydroperiod floodplain wetland

    NASA Astrophysics Data System (ADS)

    Batson, Jackie; Noe, Gregory B.; Hupp, Cliff R.; Krauss, Ken W.; Rybicki, Nancy B.; Schenk, Edward R.

    2015-01-01

    the controls on floodplain carbon (C) cycling is important for assessing greenhouse gas emissions and the potential for C sequestration in river-floodplain ecosystems. We hypothesized that greater hydrologic connectivity would increase C inputs to floodplains that would not only stimulate soil C gas emissions but also sequester more C in soils. In an urban Piedmont river (151 km2 watershed) with a floodplain that is dry most of the year, we quantified soil CO2, CH4, and N2O net emissions along gradients of floodplain hydrologic connectivity, identified controls on soil aerobic and anaerobic respiration, and developed a floodplain soil C budget. Sites were chosen along a longitudinal river gradient and across lateral floodplain geomorphic units (levee, backswamp, and toe slope). CO2 emissions decreased downstream in backswamps and toe slopes and were high on the levees. CH4 and N2O fluxes were near zero; however, CH4 emissions were highest in the backswamp. Annual CO2 emissions correlated negatively with soil water-filled pore space and positively with variables related to drier, coarser soil. Conversely, annual CH4 emissions had the opposite pattern of CO2. Spatial variation in aerobic and anaerobic respiration was thus controlled by oxygen availability but was not related to C inputs from sedimentation or vegetation. The annual mean soil CO2 emission rate was 1091 g C m-2 yr-1, the net sedimentation rate was 111 g C m-2 yr-1, and the vegetation production rate was 240 g C m-2 yr-1, with a soil C balance (loss) of -338 g C m-2 yr-1. This floodplain is losing C likely due to long-term drying from watershed urbanization.

  3. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    NASA Astrophysics Data System (ADS)

    Kiendler-Scharr, A.; Andres, S.; Bachner, M.; Behnke, K.; Broch, S.; Hofzumahaus, A.; Holland, F.; Kleist, E.; Mentel, T. F.; Rubach, F.; Springer, M.; Steitz, B.; Tillmann, R.; Wahner, A.; Schnitzler, J.-P.; Wildt, J.

    2011-08-01

    Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar, modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. Nucleation rates of up to 3600 cm-3 s-1 were observed in our experiments. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m-2 s-1 in non-transgenic controls (wild type WT) and nearly zero (<0.5 nmol m-2 s-1) in isoprene emission-repressed lines (line RA22), respectively. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3 % of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  4. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    NASA Astrophysics Data System (ADS)

    Kiendler-Scharr, A.; Andres, S.; Bachner, M.; Behnke, K.; Broch, S.; Hofzumahaus, A.; Holland, F.; Kleist, E.; Mentel, T. F.; Rubach, F.; Springer, M.; Steitz, B.; Tillmann, R.; Wahner, A.; Schnitzler, J.-P.; Wildt, J.

    2012-01-01

    Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m-2 s-1 in non-transgenic controls (wild type WT) and nearly zero (<0.5 nmol m-2 s-1) in isoprene emission-repressed plants (line RA22), respectively. Nucleation rates of up to 3600 cm-3 s-1 were observed in our experiments. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3% of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  5. Application of an online-coupled regional climate model, WRF-CAM5, over East Asia for examination of ice nucleation schemes. Part II. Sensitivity to heterogeneous ice nucleation parameterizations and dust emissions

    SciTech Connect

    Zhang, Yang; Chen, Ying; Fan, Jiwen; Leung, Lai -Yung

    2015-09-14

    Aerosol particles can affect cloud microphysical properties by serving as ice nuclei (IN). Large uncertainties exist in the ice nucleation parameterizations (INPs) used in current climate models. In this Part II paper, to examine the sensitivity of the model predictions to different heterogeneous INPs, WRF-CAM5 simulation using the INP of Niemand et al. (N12) [1] is conducted over East Asia for two full years, 2006 and 2011, and compared with simulation using the INP of Meyers et al. (M92) [2], which is the original INP used in CAM5. M92 calculates the nucleated ice particle concentration as a function of ice supersaturation, while N12 represents the nucleated ice particle concentration as a function of temperature and the number concentrations and surface areas of dust particles. Compared to M92, the WRF-CAM5 simulation with N12 produces significantly higher nucleated ice crystal number concentrations (ICNCs) in the northern domain where dust sources are located, leading to significantly higher cloud ice number and mass concentrations and ice water path, but the opposite is true in the southern domain where temperatures and moistures play a more important role in ice formation. Overall, the simulation with N12 gives lower downward shortwave radiation but higher downward longwave radiation, cloud liquid water path, cloud droplet number concentrations, and cloud optical depth. The increase in cloud optical depth and the decrease in downward solar flux result in a stronger shortwave and longwave cloud forcing, and decreases temperature at 2-m and precipitation. Changes in temperature and radiation lower surface concentrations of OH, O₃, SO₄²⁻, and PM2.5, but increase surface concentrations of CO, NO₂, and SO₂ over most of the domain. By acting as cloud condensation nuclei (CCN) and IN, dust particles have different impacts on cloud water and ice number concentrations, radiation, and temperature at 2-m and precipitation depending on

  6. Application of an online-coupled regional climate model, WRF-CAM5, over East Asia for examination of ice nucleation schemes. Part II. Sensitivity to heterogeneous ice nucleation parameterizations and dust emissions

    DOE PAGESBeta

    Zhang, Yang; Chen, Ying; Fan, Jiwen; Leung, Lai -Yung

    2015-09-14

    Aerosol particles can affect cloud microphysical properties by serving as ice nuclei (IN). Large uncertainties exist in the ice nucleation parameterizations (INPs) used in current climate models. In this Part II paper, to examine the sensitivity of the model predictions to different heterogeneous INPs, WRF-CAM5 simulation using the INP of Niemand et al. (N12) [1] is conducted over East Asia for two full years, 2006 and 2011, and compared with simulation using the INP of Meyers et al. (M92) [2], which is the original INP used in CAM5. M92 calculates the nucleated ice particle concentration as a function of icemore » supersaturation, while N12 represents the nucleated ice particle concentration as a function of temperature and the number concentrations and surface areas of dust particles. Compared to M92, the WRF-CAM5 simulation with N12 produces significantly higher nucleated ice crystal number concentrations (ICNCs) in the northern domain where dust sources are located, leading to significantly higher cloud ice number and mass concentrations and ice water path, but the opposite is true in the southern domain where temperatures and moistures play a more important role in ice formation. Overall, the simulation with N12 gives lower downward shortwave radiation but higher downward longwave radiation, cloud liquid water path, cloud droplet number concentrations, and cloud optical depth. The increase in cloud optical depth and the decrease in downward solar flux result in a stronger shortwave and longwave cloud forcing, and decreases temperature at 2-m and precipitation. Changes in temperature and radiation lower surface concentrations of OH, O₃, SO₄²⁻, and PM2.5, but increase surface concentrations of CO, NO₂, and SO₂ over most of the domain. By acting as cloud condensation nuclei (CCN) and IN, dust particles have different impacts on cloud water and ice number concentrations, radiation, and temperature at 2-m and precipitation depending on whether the

  7. Exhaust emissions survey of a turbofan engine for flame holder swirl type augmentors at simulated altitude flight conditions

    NASA Technical Reports Server (NTRS)

    Moss, J. E., Jr.

    1981-01-01

    Emissions of carbon dioxide, total oxides of nitrogen, unburned hydrocarbons, and carbon monoxide from an F100 afterburning two spool turbofan engine at simulated flight conditions are reported. Tests were run at Mach 0.8 at altitudes of 10.97 and 13.71 km (36,000 and 45,000 ft), and at Mach 1.2 at 13.71 km (45,000 ft). Emission measurements were made from intermediate power (nonafterburning) through maximum afterburning, using a single point gas sample probe traversed across the horizontal diameter of the exhaust nozzle. The data show that emissions vary with flight speed, altitude, power level, and radial position across the nozzle. Carbon monoxide emissions were low for intermediate and partial afterburning power. Unburned hydrocarbons were near zero for most of the simulated flight conditions. At maximum afterburning, there were regions of NOx deficiency in regions of high CO. The results suggest that the low NOx levels observed in the tests are a result of interaction with high CO in the thermal converter. CO2 emissions were proportional to local fuel air ratio for all test conditions.

  8. Oceanic Emissions and Atmospheric Depositions of Volatile Organic Compounds

    NASA Astrophysics Data System (ADS)

    Yang, M.; Blomquist, B.; Beale, R.; Nightingale, P. D.; Liss, P. S.

    2015-12-01

    Atmospheric volatile organic compounds (VOCs) affect the tropospheric oxidative capacity due to their ubiquitous abundance and relatively high reactivity towards the hydroxyal radical. Over the ocean and away from terrestrial emission sources, oxygenated volatile organic compounds (OVOCs) make up a large fraction of VOCs as airmasses age and become more oxidized. In addition to being produced or destroyed in the marine atmosphere, OVOCs can also be emitted from or deposited to the surface ocean. Here we first present direct air-sea flux measurements of three of the most abundant OVOCs - methanol, acetone, and acetaldehyde, by the eddy covariance technique from two cruises in the Atlantic: the Atlantic Meridional Transect in 2012 and the High Wind Gas Exchange Study in 2013. The OVOC mixing ratios were quantified by a high resolution proton-reaction-transfer mass spectrometer with isotopically labeled standards and their air-sea (net) fluxes were derived from the eddy covariance technique. Net methanol flux was consistently from the atmosphere to the surface ocean, while acetone varied from supersaturation (emission) in the subtropics to undersaturation (deposition) in the higher latitudes of the North Atlantic. The net air-sea flux of acetaldehyde is near zero through out the Atlantic despite the apparent supersaturation of this compound in the surface ocean. Knowing the dissolved concentrations and in situ production rates of these compounds in seawater, we then estimate their bulk atmospheric depositions and oceanic emissions. Lastly, we summarize the state of knowledge on the air-sea transport of a number of organic gasses, and postulate the magnitude and environmental impact of total organic carbon transfer between the ocean and the atmosphere.

  9. Greenhouse gas emission and microbial community dynamics during simultaneous nitrification and denitrification process.

    PubMed

    Kong, Qiang; Wang, Zhi-Bin; Niu, Peng-Fei; Miao, Ming-Sheng

    2016-06-01

    This study evaluates greenhouse gas emission and the microbial community dynamics during simultaneous nitrification and denitrification (SND) process. Based on CO2 equivalents, the SND reactor released 4.28g of greenhouse gases each cycle. 2.91% of the incoming nitrogen load was emitted as N2O. The CO2 and N2O emissions mainly occurred in the aerobic stage and CH4 emissions were consistently near zero. Extracellular polymeric substance (EPS) contents in activated sludge increased during start-up the SND process. High-throughput sequencing showed increases in bacterial species richness, leading to changes in EPS content and composition observed using 3D-EEM fluorescence spectra. For denitrifying bacteria, the relative abundance of Pseudomonas significantly increased during the SND process, while Paracoccus decreased significantly. For phosphorus-accumulating bacteria, the relative abundance of Rhodocyclaceae also significantly increased. The relative abundance of other functional microbes, such as Nitrosomonadaceae (ammonia oxidizer), Nitrospirales (nitrite oxidizer) and Planctomyces (anammox) decreased significantly during the SND process. PMID:26935325

  10. Measurements of Marine Vessel Emissions

    NASA Astrophysics Data System (ADS)

    Williams, E. J.; Lerner, B. M.; Middlebrook, A. M.

    2003-12-01

    Nitrogen and sulfur emissions from large marine vessels are a significant source of these species to the atmosphere. One estimate indicates that oxidized nitrogen from this source is at least 14% of all combustion emissions globally (1). More importantly, since approximately 70% of all ship emissions occur within 400 km of land (1) marine vessel emissions are of significance regionally in coastal areas and locally in ports. Marine vessel emissions are calculated from marine fuel usage and various emission factors, where sulfur emission factors depend on the sulfur content of fuel and nitrogen emission factors depend on the vessel engine type: slow-speed diesel, medium-speed diesel, and other (generally steam-turbine). Currently, the best available emission factors come from a Lloyd's Register of Shipping sponsored emissions research program. Measurements were made of emissions from engines during bench tests and from in-service marine vessels directly at the stack. While these results are the best available data, the significance of marine vessel emissions suggests that additional evaluation of emission factors be conducted. During the 2002 New England Air Quality Study (NEAQS 2002) the NOAA research vessel Ronald H. Brown was equipped with trace gas and aerosol monitoring instrumentation for the purpose of investigating the factors that affect air quality in coastal New England. As a part of that study, measurements were made of gaseous and particulate emissions from marine vessels, both in port and underway. This talk will present those results and relate them to current inventory estimates of marine vessel emissions. (1) Corbett, J.J., et al., Global nitrogen and sulfur inventories for oceangoing ships, J. Geophy. Res., 104, 3457-3470, 1999.

  11. Parts Specialist.

    ERIC Educational Resources Information Center

    Fuqua, Lou; Fuqua, Debbie

    Designed to address the skills that an auto parts specialist must master in order to be effective in the market place, this manual consists of 13 units of instruction. Covered in the units are orientation; human relations; communications; safety; parts and systems identification; stocking, shipping, and receiving; inventory control; cataloging and…

  12. 40 CFR 88.311-93 - Emissions standards for Inherently Low-Emission Vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Test Procedure (FTP), modified for ILEV certification, from 40 CFR part 86, subpart B for LDVs and LDTs and from 40 CFR part 86, subpart M for HDVs. (A) After disabling any and all auxiliary emission... CFR part 86). (B) Conventional Federal Test Procedure. A vehicle with no evaporative emissions...

  13. 40 CFR 1066.835 - Exhaust emission test procedure for SC03 emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... exhaust emissions while simulating an urban trip on a hot summer day. The provisions of 40 CFR part 86 and 40 CFR part 600 waive SC03 testing for some vehicles; in those cases, calculate SFTP composite emissions by adjusting the weighting calculation as specified in 40 CFR part 86, subpart S. (a) Drain...

  14. Motorcycle Parts

    NASA Technical Reports Server (NTRS)

    1993-01-01

    An article in NASA Tech Briefs describing a vacuum bagging process for forming composite parts helped a small Oklahoma Company to improve its manufacturing process. President of Performance Extremes, Larry Ortega, and his partners make motorcycle parts from carbon/epoxy to reduce weight. Using vacuum bags, parts have a better surface and fewer voids inside. When heat used in the vacuum bag process caused deformation upon cooling, a solution found in another tech brief solved the problem. A metal plate inside the vacuum bag made for more even heat transfer. A third article described a simple procedure for repairing loose connector pins, which the company has also utilized.

  15. Modeling dry and wet deposition of sulfate, nitrate, and ammonium ions in Jiuzhaigou National Nature Reserve, China using a source-oriented CMAQ model: Part II. Emission sector and source region contributions.

    PubMed

    Qiao, Xue; Tang, Ya; Kota, Sri Harsha; Li, Jingyi; Wu, Li; Hu, Jianlin; Zhang, Hongliang; Ying, Qi

    2015-11-01

    A source-oriented Community Multiscale Air Quality (CMAQ) model driven by the meteorological fields generated by the Weather Research and Forecasting (WRF) model was used to study the dry and wet deposition of nitrate (NO3(-)), sulfate (SO4(2-)), and ammonium (NH4(+)) ions in the Jiuzhaigou National Nature Reserve (JNNR), China from June to August 2010 and to identify the contributions of different emission sectors and source regions that were responsible for the deposition fluxes. Contributions from power plants, industry, transportation, domestic, biogenic, windblown dust, open burning, fertilizer, and manure management sources to deposition fluxes in JNNR watershed and four EANET sites are determined. In JNNR, 96%, 82%, and 87% of the SO4(2-), NO3(-) and NH4(+) deposition fluxes are in the form of wet deposition of the corresponding aerosol species. Industry and power plants are the two major sources of SO4(2-) deposition flux, accounting for 86% of the total wet deposition of SO4(2-), and industry has a higher contribution (56%) than that of power plants (30%). Power plants and industry are also the top sources that are responsible for NO3(-) wet deposition, and contributions from power plants (30%) are generally higher than those from industries (21%). The major sources of NH4(+) wet deposition flux in JNNR are fertilizer (48%) and manure management (39%). Source-region apportionment confirms that SO2 and NOx emissions from local and two nearest counties do not have a significant impact on predicted wet deposition fluxes in JNNR, with contributions less than 10%. While local NH3 emissions account for a higher fraction of the NH4(+) deposition, approximately 70% of NH4(+) wet deposition in JNNR originated from other source regions. This study demonstrates that S and N deposition in JNNR is mostly from long-range transport rather than from local emissions, and to protect JNNR, regional emission reduction controls are needed. PMID:26050092

  16. Mixing of Multiple Jets with a Confined Subsonic Crossflow: Part III--The Effects of Air Preheat and Number of Orifices on Flow and Emissions in an RQL Mixing Section

    NASA Technical Reports Server (NTRS)

    Holdemann, James D.; Chang, Clarence T.

    2008-01-01

    This study was motivated by a goal to understand the mixing and emissions in the Rich-burn/Quick-mix/Lean-burn (RQL) combustor scheme that has been proposed to minimize the formation of oxides of nitrogen (NOx) in gas turbine combustors. The study reported herein was a reacting jet-in-crossflow experiment at atmospheric pressure. The jets were injected from the perimeter of a cylindrical duct through round-hole orifices into a fuel-rich mainstream flow. The number of orifices investigated in this study gave over- to optimum to underpenetrating jets at a jet-to-mainstream momentum-flux ratio of J = 57. The size of individual orifices was decreased as the number of orifices increased to maintain a constant total area; the jet-to-mainstream mass-flow ratio was constant at MR = 2.5. The experiments focused on the effects of the number of orifices and inlet air preheat and were conducted in a facility that provided the capability for independent variation of jet and main inlet air preheat temperature. The number of orifices was found to have a significant effect on mixing and the distributions of species, but very little effect on overall NOx emissions, suggesting that an aerodynamically optimum mixer might not minimize NOx emissions. Air preheat was found to have very little effect on mixing and the distributions of major species, but preheating both main and jet air did increase NOx emissions significantly. Although the air jets injected in the quick-mix section of an RQL combustor may comprise over 70 percent of the total air flow, the overall NOx emission levels were found to be more sensitive to main stream air preheat than to jet stream air preheat.

  17. Synthesis and development of processes for the recovery of sulfur from acid gases. Part 1, Development of a high-temperature process for removal of H{sub 2}S from coal gas using limestone -- thermodynamic and kinetic considerations; Part 2, Development of a zero-emissions process for recovery of sulfur from acid gas streams

    SciTech Connect

    Towler, G.P.; Lynn, S.

    1993-05-01

    Limestone can be used more effectively as a sorbent for H{sub 2}S in high-temperature gas-cleaning applications if it is prevented from undergoing calcination. Sorption of H{sub 2}S by limestone is impeded by sintering of the product CaS layer. Sintering of CaS is catalyzed by CO{sub 2}, but is not affected by N{sub 2} or H{sub 2}. The kinetics of CaS sintering was determined for the temperature range 750--900{degrees}C. When hydrogen sulfide is heated above 600{degrees}C in the presence of carbon dioxide elemental sulfur is formed. The rate-limiting step of elemental sulfur formation is thermal decomposition of H{sub 2}S. Part of the hydrogen thereby produced reacts with CO{sub 2}, forming CO via the water-gas-shift reaction. The equilibrium of H{sub 2}S decomposition is therefore shifted to favor the formation of elemental sulfur. The main byproduct is COS, formed by a reaction between CO{sub 2} and H{sub 2}S that is analogous to the water-gas-shift reaction. Smaller amounts of SO{sub 2} and CS{sub 2} also form. Molybdenum disulfide is a strong catalyst for H{sub 2}S decomposition in the presence of CO{sub 2}. A process for recovery of sulfur from H{sub 2}S using this chemistry is as follows: Hydrogen sulfide is heated in a high-temperature reactor in the presence of CO{sub 2} and a suitable catalyst. The primary products of the overall reaction are S{sub 2}, CO, H{sub 2} and H{sub 2}O. Rapid quenching of the reaction mixture to roughly 600{degrees}C prevents loss Of S{sub 2} during cooling. Carbonyl sulfide is removed from the product gas by hydrolysis back to CO{sub 2} and H{sub 2}S. Unreacted CO{sub 2} and H{sub 2}S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H{sub 2} and CO, which recovers the hydrogen value from the H{sub 2}S. This process is economically favorable compared to the existing sulfur-recovery technology and allows emissions of sulfur-containing gases to be controlled to very low levels.

  18. 40 CFR 1045.10 - How is this part organized?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... references to other parts of the Code of Federal Regulations). (g) Subpart G of this part and 40 CFR part... CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Overview...

  19. 40 CFR 1045.10 - How is this part organized?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... references to other parts of the Code of Federal Regulations). (g) Subpart G of this part and 40 CFR part... CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Overview...

  20. 40 CFR Table 3 to Subpart Ffff of... - Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP Metals Emissions From...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Emission Limits for Hydrogen Halide and... to Subpart FFFF of Part 63—Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP... following table that applies to your process vents that contain hydrogen halide and halogen HAP emissions...

  1. 40 CFR Table 3 to Subpart Ffff of... - Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP Metals Emissions From...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Emission Limits for Hydrogen Halide and... to Subpart FFFF of Part 63—Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP... following table that applies to your process vents that contain hydrogen halide and halogen HAP emissions...

  2. A Community Emissions Data System (CEDS) for Historical Emissions

    SciTech Connect

    Smith, Steven J.; Zhou, Yuyu; Kyle, G. Page; Wang, Hailong; Yu, Hongbin

    2015-04-21

    Historical emission estimates for anthropogenic aerosol and precursor compounds are key data needed for Earth system models, climate models, and atmospheric chemistry and transport models; both for general analysis and assessment and also for model validation through comparisons with observations. Current global emission data sets have a number of shortcomings, including timeliness and transparency. Satellite and other earth-system data are increasingly available in near real-time, but global emission estimates lag by 5-10 years. The CEDS project will construct a data-driven, open source framework to produce annually updated emission estimates. The basic methodologies to be used for this system have been used for SO2 (Smith et al. 2011, Klimont, Smith and Cofala 2013), and are designed to complement existing inventory efforts. The goal of this system is to consistently extend current emission estimates both forward in time to recent years and also back over the entire industrial era. The project will produce improved datasets for global and (potentially) regional model, allow analysis of trends across time, countries, and sectors of emissions and emission factors, and facilitate improved scientific analysis in general. Consistent estimation of uncertainty will be an integral part of this system. This effort will facilitate community evaluation of emissions and further emission-related research more generally.

  3. Narrow-band light emission from a single carbon nanotube p-n diode

    NASA Astrophysics Data System (ADS)

    Kinoshita, Megumi; Mueller, Thomas; Steiner, Mathias; Perebeinos, Vasili; Bol, Ageeth; Farmer, Damon; Avouris, Phaedon

    2010-03-01

    We present the first observation of electroluminescence from electrostatically-generated carbon nanotube (CNT) p-n junctions[1]. While CNT optoelectronics has made much progress in recent years, observations of emission from electrically excited CNT devices have been limited to the high-bias regime and with low efficiency. Furthermore, the resulting broad linewidths are broad, making it difficult to investigate electronic levels and carrier dynamics. We find that p-n junctions allow for better carrier control at lower power inputs, resulting in emission with near-zero threshold, low self-heating and efficiency two to three orders of magnitude greater compared to previous device configurations. This yields higher signal-to-noise ratio and narrower linewidths (down to ˜35 meV) that allows us to identify localized excitonic transitions that have previously been observed only in photoluminescent studies. [1] T. Mueller, M. Kinoshita, M. Steiner, V. Perebeinos, A. Bol, D. Farmer, and Ph. Avouris, Nature Nanotech., web publication, November 15 2009.

  4. Emissions from photovoltaic life cycles.

    PubMed

    Fthenakis, Vasilis M; Kim, Hyung Chul; Alsema, Erik

    2008-03-15

    Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004-2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid. PMID:18409654

  5. Emissions Overview

    NASA Technical Reports Server (NTRS)

    Rohde, John

    2001-01-01

    The Emissions Reduction Project is working in close partnership with the U.S. aircraft engine manufacturers and academia to develop technologies to reduce NO, emissions by 70 percent over the LTO cycle from 1996 ICAO standards with no increase in other emission constituents (carbon monoxide, smoke, and unburned hydrocarbons) and with comparable NO, reduction during cruise operations. These technologies cannot impact the overall combustor and fuel delivery system operability, affordability or maintainability. These new combustion concepts and technologies will include lean burning combustors with higher operating gas temperatures and pressures, fuel staging, ceramic matrix composite material liners with reduced cooling air and possibly advanced controls. Improved physics-based analysis tool will be developed and validated and some longer term technologies that are more revolutionary will be assessed. These improved computational codes will provide improved design tools to increase design confidence and cut the development time to achieve major reductions in NO, emissions. Longer term, revolutionary technologies like active combustion controls, combustion from a large array of micro-injectors, electrostatic fuel injectors, fuel additives and others will be investigated and assessed through proof-of-concept testing.

  6. Reducing environmental emissions in tanneries.

    PubMed

    van Groenestijn, J W; Langerwerf, J S A; Lucas, M

    2002-01-01

    Tanning, in particular chrome leather production, is still characterised by an inefficient use of raw material and the production of highly polluted wastewater and solid wastes. A part of the emissions can be prevented by introducing clean tanning technologies, the remaining emissions can be treated. Clean production technologies and waste (water) treatment technologies should have a designed complimentarity. Anaerobic wastewater treatment with recovery of sulfides, sulfur and energy (biogas) is a cornerstone in such integral clean chrome leather technology. PMID:12046670

  7. Greenhouse gas emissions and soil indicators four years after manure and compost applications.

    PubMed

    Ginting, Daniel; Kessavalou, Anabayan; Eghball, Bahman; Doran, John W

    2003-01-01

    Understanding how carbon, nitrogen, and key soil attributes affect gas emissions from soil is crucial for alleviating their undesirable residual effects that can linger for years after termination of manure and compost applications. This study was conducted to evaluate the emission of soil CO2, N2O, and CH4 and soil C and N indicators four years after manure and compost application had stopped. Experimental plots were treated with annual synthetic N fertilizer (FRT), annual and biennial manure (MN1 and MN2, respectively), and compost (CP1 and CP2, respectively) from 1992 to 1995 based on removal of 151 kg N ha(-1) yr(-1) by continuous corn (Zea mays L.). The control (CTL) plots received no input. After 1995, only the FRT plots received N fertilizer in the spring of 1999. In 1999, the emissions of CO2 were similar between control and other treatments. The average annual carbon input in the CTL and FRT plots were similar to soil CO2-C emission (4.4 and 5.1 Mg C ha(-1) yr(-1), respectively). Manure and compost resulted in positive C and N balances in the soil four years after application. Fluxes of CH4-C and N2O-N were nearly zero, which indicated that the residual effects of manure and compost four years after application had no negative influence on soil C and N storage and global warming. Residual effects of compost and manure resulted in 20 to 40% higher soil microbial biomass C, 42 to 74% higher potentially mineralizable N, and 0.5 unit higher pH compared with the FRT treatment. Residual effects of manure and compost on CO2, N20, and CH4 emissions were minimal and their benefits on soil C and N indicators were more favorable than that of N fertilizer. PMID:12549538

  8. Air Pollution Control, Part I.

    ERIC Educational Resources Information Center

    Strauss, Werner, Ed.

    Authoritative reviews in seven areas of current importance in air pollution control are supplied in this volume, the first of a two-part set. Titles contained in this book are: "Dispersion of Pollutants Emitted into the Atmosphere,""The Formation and Control of Oxides of Nitrogen in Air Pollution,""The Control of Sulfur Emissions from Combustion…

  9. Modelling the role of fires in the terrestrial carbon balance by incorporating SPITFIRE into the global vegetation model ORCHIDEE - Part 2: Carbon emissions and the role of fires in the global carbon balance

    NASA Astrophysics Data System (ADS)

    Yue, C.; Ciais, P.; Cadule, P.; Thonicke, K.; van Leeuwen, T. T.

    2015-05-01

    Carbon dioxide emissions from wild and anthropogenic fires return the carbon absorbed by plants to the atmosphere, and decrease the sequestration of carbon by land ecosystems. Future climate warming will likely increase the frequency of fire-triggering drought, so that the future terrestrial carbon uptake will depend on how fires respond to altered climate variation. In this study, we modelled the role of fires in the global terrestrial carbon balance for 1901-2012, using the ORCHIDEE global vegetation model equipped with the SPITFIRE model. We conducted two simulations with and without the fire module being activated, using a static land cover. The simulated global fire carbon emissions for 1997-2009 are 2.1 Pg C yr-1, which is close to the 2.0 Pg C yr-1 as estimated by GFED3.1. The simulated land carbon uptake after accounting for emissions for 2003-2012 is 3.1 Pg C yr-1, which is within the uncertainty of the residual carbon sink estimation (2.8 ± 0.8 Pg C yr-1). Fires are found to reduce the terrestrial carbon uptake by 0.32 Pg C yr-1 over 1901-2012, or 20% of the total carbon sink in a world without fire. The fire-induced land sink reduction (SRfire) is significantly correlated with climate variability, with larger sink reduction occurring in warm and dry years, in particular during El Niño events. Our results suggest a "fire respiration partial compensation". During the 10 lowest SRfire years (SRfire = 0.17 Pg C yr-1), fires mainly compensate for the heterotrophic respiration that would occur in a world without fire. By contrast, during the 10 highest SRfire fire years (SRfire = 0.49 Pg C yr-1), fire emissions far exceed their respiration partial compensation and create a larger reduction in terrestrial carbon uptake. Our findings have important implications for the future role of fires in the terrestrial carbon balance, because the capacity of terrestrial ecosystems to sequester carbon will be diminished by future climate change characterized by increased

  10. Modelling the role of fires in the terrestrial carbon balance by incorporating SPITFIRE into the global vegetation model ORCHIDEE - Part 2: Carbon emissions and the role of fires in the global carbon balance

    NASA Astrophysics Data System (ADS)

    Yue, C.; Ciais, P.; Cadule, P.; Thonicke, K.; van Leeuwen, T. T.

    2014-12-01

    Carbon dioxide emissions from wild and anthropogenic fires return the carbon absorbed by plants to the atmosphere, and decrease the sequestration of carbon by land ecosystems. Future climate warming will likely increase the frequency of fire-triggering drought; so that the future terrestrial carbon uptake will depend on how fires respond to altered climate variation. In this study, we modelled the role of fires in the global terrestrial carbon balance for 1901-2012, using the global vegetation model ORCHIDEE equipped with the SPITFIRE model. We conducted two simulations with and without the fire module being activated, with a static land cover. The simulated global fire carbon emissions for 1997-2009 are 2.1 Pg C yr-1, which is close to the 2.0 Pg C yr-1 as given by the GFED3.1 data. The simulated land carbon uptake after accounting for emissions for 2003-2012 is 3.1Pg C yr-1, within the uncertainty of the residual carbon sink estimation (2.8 ± 0.8 Pg C yr-1). Fires are found to reduce the terrestrial carbon uptake by 0.32 Pg C yr-1 over 1901-2012, that is 20% of the total carbon sink in a world without fire. The fire-induced land sink reduction (SRfire) is significantly correlated with climate variability, with larger sink reduction occurring in warm and dry years, in particular during El Niño events. Our results suggest a symmetrical "respiration equivalence" by fires. During the ten lowest SRfire years (SRfire = 0.17 Pg C yr-1), fires mainly compensate the heterotrophic respiration that would happen if no fires had occurred. By contrast, during the ten highest SRfire fire years (SRfire = 0.49 Pg C yr-1), fire emissions exceed their "respiration equivalence" and create a substantial reduction in terrestrial carbon uptake. Our finding has important implication for the future role of fires in the terrestrial carbon balance, because the capacity of terrestrial ecosystems to sequester carbon will be diminished by future climate change characterized by increased

  11. 40 CFR Table 1 to Subpart Cccc of... - Emission Limitations

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Emission Limitations 1 Table 1 to... Table 1 to Subpart CCCC of Part 60—Emission Limitations For the air pollutant You must meet this... test (Method 6 or 6c of appendix A of this part. a All emission limitations (except for opacity)...

  12. 40 CFR 1037.705 - Generating and calculating emission credits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... subpart G of this part or under 40 CFR part 1068. (2) Exported vehicles. (3) Vehicles not subject to the... applicable emission standard. Calculate positive emission credits for a family or subfamily that has an FEL below the standard. Calculate negative emission credits for a family or subfamily that has an FEL...

  13. 40 CFR 1037.705 - Generating and calculating emission credits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... subpart G of this part or under 40 CFR part 1068. (2) Exported vehicles. (3) Vehicles not subject to the... applicable emission standard. Calculate positive emission credits for a family or subfamily that has an FEL below the standard. Calculate negative emission credits for a family or subfamily that has an FEL...

  14. 40 CFR 1037.705 - Generating and calculating emission credits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... subpart G of this part or under 40 CFR part 1068. (2) Exported vehicles. (3) Vehicles not subject to the... applicable emission standard. Calculate positive emission credits for a family or subfamily that has an FEL below the standard. Calculate negative emission credits for a family or subfamily that has an FEL...

  15. 40 CFR 205.152 - Noise emission standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standard. For the purpose of Low-Noise-Emission Product certification pursuant to 40 CFR part 203... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Noise emission standards. 205.152... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.152 Noise emission...

  16. 40 CFR 205.152 - Noise emission standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standard. For the purpose of Low-Noise-Emission Product certification pursuant to 40 CFR part 203... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.152 Noise emission standards. (a) Noise emission standards. (1) Street motorcycles of the following and subsequent model years...

  17. 40 CFR 205.152 - Noise emission standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standard. For the purpose of Low-Noise-Emission Product certification pursuant to 40 CFR part 203... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.152 Noise emission standards. (a) Noise emission standards. (1) Street motorcycles of the following and subsequent model years...

  18. 40 CFR 1060.10 - How is this part organized?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... meeting the standards in use. (f) Subpart F of this part describes how to measure evaporative emissions. (g) Subpart G of this part and 40 CFR part 1068 describe requirements, prohibitions, and other... CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Overview...

  19. 40 CFR 1060.10 - How is this part organized?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... meeting the standards in use. (f) Subpart F of this part describes how to measure evaporative emissions. (g) Subpart G of this part and 40 CFR part 1068 describe requirements, prohibitions, and other... CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Overview...

  20. 40 CFR 1060.10 - How is this part organized?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... meeting the standards in use. (f) Subpart F of this part describes how to measure evaporative emissions. (g) Subpart G of this part and 40 CFR part 1068 describe requirements, prohibitions, and other... CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Overview...

  1. 40 CFR 1060.10 - How is this part organized?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... meeting the standards in use. (f) Subpart F of this part describes how to measure evaporative emissions. (g) Subpart G of this part and 40 CFR part 1068 describe requirements, prohibitions, and other... CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Overview...

  2. 40 CFR 1060.10 - How is this part organized?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... meeting the standards in use. (f) Subpart F of this part describes how to measure evaporative emissions. (g) Subpart G of this part and 40 CFR part 1068 describe requirements, prohibitions, and other... CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Overview...

  3. Problems associated with the use of urea-formaldehyde foam for residential insulation. Part II. The effects of temperature and humidity on free formaldehyde, extractable formaldehyde, formaldehyde emission, and physical characteristics of the foam

    SciTech Connect

    Schutte, W.C.; Cole, R.S.; Frank, C.W.; Long, K.R.

    1981-02-01

    Results of testing with two products of urea-formaldehyde based foams are described. Results of three products have previously been reported. Methods for detection and quantitative determination of formaldehyde, design of the experimental chambers, and the procedures are described. Samples of Product D were monitored for about 29 days and samples of Product E were monitored for 60 days in chambers and results are tabulated for formaldehyde emission. Additional tests performed on the two products are: extractable formaldehyde (high and low temperature conditions); free formaldehyde (high and low temperature conditions); comparison of free formaldehyde concentration; density (high and low temperature conditions); shrinkage (high and low temperature conditions). Control panels were constructed to simulate a wall in a home and observations were made and compared with results of the experimental products.

  4. Negative Emissions Technology

    NASA Astrophysics Data System (ADS)

    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.

  5. Methane Emission by Camelids

    PubMed Central

    Dittmann, Marie T.; Runge, Ullrich; Lang, Richard A.; Moser, Dario; Galeffi, Cordula; Kreuzer, Michael; Clauss, Marcus

    2014-01-01

    Methane emissions from ruminant livestock have been intensively studied in order to reduce contribution to the greenhouse effect. Ruminants were found to produce more enteric methane than other mammalian herbivores. As camelids share some features of their digestive anatomy and physiology with ruminants, it has been proposed that they produce similar amounts of methane per unit of body mass. This is of special relevance for countrywide greenhouse gas budgets of countries that harbor large populations of camelids like Australia. However, hardly any quantitative methane emission measurements have been performed in camelids. In order to fill this gap, we carried out respiration chamber measurements with three camelid species (Vicugna pacos, Lama glama, Camelus bactrianus; n = 16 in total), all kept on a diet consisting of food produced from alfalfa only. The camelids produced less methane expressed on the basis of body mass (0.32±0.11 L kg−1 d−1) when compared to literature data on domestic ruminants fed on roughage diets (0.58±0.16 L kg−1 d−1). However, there was no significant difference between the two suborders when methane emission was expressed on the basis of digestible neutral detergent fiber intake (92.7±33.9 L kg−1 in camelids vs. 86.2±12.1 L kg−1 in ruminants). This implies that the pathways of methanogenesis forming part of the microbial digestion of fiber in the foregut are similar between the groups, and that the lower methane emission of camelids can be explained by their generally lower relative food intake. Our results suggest that the methane emission of Australia's feral camels corresponds only to 1 to 2% of the methane amount produced by the countries' domestic ruminants and that calculations of greenhouse gas budgets of countries with large camelid populations based on equations developed for ruminants are generally overestimating the actual levels. PMID:24718604

  6. Methane emission by camelids.

    PubMed

    Dittmann, Marie T; Runge, Ullrich; Lang, Richard A; Moser, Dario; Galeffi, Cordula; Kreuzer, Michael; Clauss, Marcus

    2014-01-01

    Methane emissions from ruminant livestock have been intensively studied in order to reduce contribution to the greenhouse effect. Ruminants were found to produce more enteric methane than other mammalian herbivores. As camelids share some features of their digestive anatomy and physiology with ruminants, it has been proposed that they produce similar amounts of methane per unit of body mass. This is of special relevance for countrywide greenhouse gas budgets of countries that harbor large populations of camelids like Australia. However, hardly any quantitative methane emission measurements have been performed in camelids. In order to fill this gap, we carried out respiration chamber measurements with three camelid species (Vicugna pacos, Lama glama, Camelus bactrianus; n = 16 in total), all kept on a diet consisting of food produced from alfalfa only. The camelids produced less methane expressed on the basis of body mass (0.32±0.11 L kg⁻¹ d⁻¹) when compared to literature data on domestic ruminants fed on roughage diets (0.58±0.16 L kg⁻¹ d⁻¹). However, there was no significant difference between the two suborders when methane emission was expressed on the basis of digestible neutral detergent fiber intake (92.7±33.9 L kg⁻¹ in camelids vs. 86.2±12.1 L kg⁻¹ in ruminants). This implies that the pathways of methanogenesis forming part of the microbial digestion of fiber in the foregut are similar between the groups, and that the lower methane emission of camelids can be explained by their generally lower relative food intake. Our results suggest that the methane emission of Australia's feral camels corresponds only to 1 to 2% of the methane amount produced by the countries' domestic ruminants and that calculations of greenhouse gas budgets of countries with large camelid populations based on equations developed for ruminants are generally overestimating the actual levels. PMID:24718604

  7. Kalman filter physical retrieval of surface emissivity and temperature from SEVIRI infrared channels: a validation and intercomparison study

    NASA Astrophysics Data System (ADS)

    Masiello, G.; Serio, C.; Venafra, S.; Liuzzi, G.; Göttsche, F.; Trigo, I. F.; Watts, P.

    2015-07-01

    A Kalman filter-based approach for the physical retrieval of surface temperature and emissivity from SEVIRI (Spinning Enhanced Visible and Infrared Imager) infrared observations has been developed and validated against in situ and satellite observations. Validation for land has been provided based on in situ observations from the two permanent stations at Evora and Gobabeb operated by Karlsruhe Institute of Technology (KIT) within the framework of EUMETSAT's Satellite Application Facility on Land Surface Analysis (LSA SAF). Sea surface retrievals have been intercompared on a broad spatial scale with equivalent satellite products (MODIS, Moderate Resolution Imaging Spectroradiometer, and AVHRR, Advanced Very High Resolution Radiometer) and ECMWF (European Centre for Medium-Range Weather Forecasts) analyses. For surface temperature, the Kalman filter yields a root mean square accuracy of ≍ ±1.5 °C for the two land sites considered and ≍ ±1.0 °C for the sea. Comparisons with polar satellite instruments over the sea surface show nearly zero temperature bias. Over the land surface the retrieved emissivity follows the seasonal vegetation cycle and permits identification of desert sand regions using the SEVIRI channel at 8.7 μm due to the strong quartz reststrahlen bands around 8-9 μm. Considering the two validation stations, we have found that emissivity retrieved in SEVIRI channel 10.8 μm over the gravel plains of the Namibian desert is in excellent agreement with in situ observations. Over Evora, the seasonal variation of emissivity with vegetation is successfully retrieved and yields emissivity values for green and dry vegetation that are in good agreement with spectral library data. The algorithm has been applied to the SEVIRI full disk, and emissivity maps on that global scale have been physically retrieved for the first time.

  8. Kalman filter physical retrieval of surface emissivity and temperature from SEVIRI infrared channels: a validation and inter-comparison study

    NASA Astrophysics Data System (ADS)

    Masiello, G.; Serio, C.; Venafra, S.; Liuzzi, G.; Göttsche, F.; Trigo, I. F.; Watts, P.

    2015-04-01

    A Kalman filter based approach for the physical retrieval of surface temperature and emissivity from SEVIRI (Spinning Enhanced Visible and Infrared Imager) infrared observations has been developed and validated against in situ and satellite observations. Validation for land has been provided based on in situ observations from the two permanent stations Evora and Gobabeb operated by Karlsruhe Institute of Technology (KIT) within the framework of EUMETSAT's Satellite Application Facility on Land Surface Analysis (LSA-SAF). Sea surface retrievals have been intercompared on a broad spatial scale with equivalent satellite products (MODIS or Moderate Resolution Imaging Spectroradiometer and AVHRR or Advanced Very High Resolution Radiometer) and ECMWF (European Centre for Medium Range Weather Forecasts) analyses. Results show that for surface temperature the algorithm yields an accuracy of ≈ ± 1.5 °C in case of land and ≈ ± 1.0 °C in case of sea surface. Comparisons with polar satellite instruments over the sea surface show nearly zero temperature bias. Over the land surface the retrieved emissivity follows the seasonal vegetation cycle and allows to identify desert sand regions because of strong reststrahlen bands of Quartz in the SEVIRI channel at 8.7 μm. Considering the two validation stations, we have that emissivity retrieved in SEVIRI channel 10.8 μm over the gravel plains of the Namib desert is in excellent agreement with in situ observations. Over Evora, the seasonal variation of emissivity with vegetation is successfully retrieved and yields emissivity values for green and dry vegetation that are in good agreement with spectral library data. The algorithm has been applied to the SEVIRI full disk and emissivity maps on that global scale have been physically retrieved for the first time.

  9. 40 CFR Table 1 to Subpart Eeee of... - Emission Limitations

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Emission Limitations 1 Table 1 to... Subpart EEEE of Part 60—Emission Limitations As stated in § 60.2915, you must comply with the following... minimum sample time per run) Method 29 of appendix A of this part. 2. Carbon monoxide 40 parts per...

  10. 40 CFR 1045.5 - Which engines are excluded from this part's requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 CFR part 90, 1048, or 1054 for the exhaust emission standards that apply. Evaporative emission... the requirements of 40 CFR part 1042 instead of this part even if they would otherwise meet the... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES...

  11. 76 FR 18415 - Continuous Emission Monitoring

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 75 Continuous Emission Monitoring CFR Correction In Title 40 of the Code of Federal... read as follows: Sec. 75.11 Specific provisions for monitoring SO 2 emissions. * * * * * (f)...

  12. 47 CFR 90.210 - Emission masks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission masks. 90.210 Section 90.210 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.210 Emission masks. Except as indicated elsewhere in this part, transmitters used in...

  13. 40 CFR 63.1403 - Emission standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... this subpart, emissions shall be vented through a closed vent system meeting the requirements of 40 CFR part 63, subpart SS (national emission standards for closed vent systems, control devices, recovery... no organic HAP are used or manufactured. (2) When a flexible operations process unit is...

  14. 40 CFR 63.1403 - Emission standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... complying with this subpart, emissions shall be vented through a closed vent system meeting the requirements of 40 CFR part 63, subpart SS (national emission standards for closed vent systems, control devices... no organic HAP are used or manufactured. (2) When a flexible operations process unit is...

  15. 40 CFR 63.1403 - Emission standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... this subpart, emissions shall be vented through a closed vent system meeting the requirements of 40 CFR part 63, subpart SS (national emission standards for closed vent systems, control devices, recovery... no organic HAP are used or manufactured. (2) When a flexible operations process unit is...

  16. REGIONAL AIR POLLUTION STUDY: HEAT EMISSION INVENTORY

    EPA Science Inventory

    As part of the St. Louis Regional Air Pollution Study (RAPS), a heat emission inventory has been assembled. Heat emissions to the atmosphere originate, directly or indirectly, from the combustion of fossil fuels (there are no nuclear plants in the St. Louis AQCR). With the except...

  17. 40 CFR Appendix 1 to Part 3 - Priority Reports

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... by units subject to acid rain emissions limitations 72.90. Annual Compliance Certification Report.... 1 Appendix 1 to Part 3—Priority Reports Category Description 40 CFR Citation Required Reports State... in 40 CFR 65.6(c) 65.5(d), 65.5(e). Continuous Emissions Monitoring Quarterly emissions...

  18. 40 CFR Appendix 1 to Part 3 - Priority Reports

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... by units subject to acid rain emissions limitations 72.90. Annual Compliance Certification Report.... 1 Appendix 1 to Part 3—Priority Reports Category Description 40 CFR Citation Required Reports State... in 40 CFR 65.6(c) 65.5(d), 65.5(e). Continuous Emissions Monitoring Quarterly emissions...

  19. 40 CFR Appendix 1 to Part 3 - Priority Reports

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... by units subject to acid rain emissions limitations 72.90. Annual Compliance Certification Report.... 1 Appendix 1 to Part 3—Priority Reports Category Description 40 CFR Citation Required Reports State... in 40 CFR 65.6(c) 65.5(d), 65.5(e). Continuous Emissions Monitoring Quarterly emissions...

  20. 40 CFR Table 3 to Subpart Ffff of... - Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP Metals Emissions From...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Emission Limits for Hydrogen Halide and..., Table 3 Table 3 to Subpart FFFF of Part 63—Emission Limits for Hydrogen Halide and Halogen HAP Emissions... limit in the following table that applies to your process vents that contain hydrogen halide and...

  1. 40 CFR Appendix B to Part 60 - Performance Specifications

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR Part 60, Appendix B, “Performance Specification 2—Specifications and Test Procedures for SO2 and NOX Continuous Emission Monitoring Systems in Stationary Sources.” 17.240 CFR Part 60, Appendix B... Procedures for TRS Continuous Emission Monitoring Systems in Stationary Sources Performance Specification...

  2. 40 CFR Appendix B to Part 60 - Performance Specifications

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR Part 60, Appendix B, “Performance Specification 2—Specifications and Test Procedures for SO2 and NOX Continuous Emission Monitoring Systems in Stationary Sources.” 17.240 CFR Part 60, Appendix B... Procedures for TRS Continuous Emission Monitoring Systems in Stationary Sources Performance Specification...

  3. 40 CFR Appendix B to Part 60 - Performance Specifications

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....0Pollution Prevention 15.0Waste Management 16.0Alternative Procedures 17.0Bibliography 17.140 CFR Part 60... Emission Monitoring Systems in Stationary Sources.” 17.240 CFR Part 60, Appendix B, “Performance... Procedures for TRS Continuous Emission Monitoring Systems in Stationary Sources Performance Specification...

  4. Survey of emissivity measurement by radiometric methods.

    PubMed

    Honner, M; Honnerová, P

    2015-02-01

    A survey of the state of the art in the field of spectral directional emissivity measurements by using radiometric methods is presented. Individual quantity types such as spectral, band, or total emissivity are defined. Principles of emissivity measurement by various methods (direct and indirect, and calorimetric and radiometric) are discussed. The paper is focused on direct radiometric methods. An overview of experimental setups is provided, including the design of individual parts such as the applied reference sources of radiation, systems of sample clamping and heating, detection systems, methods for the determination of surface temperature, and procedures for emissivity evaluation. PMID:25967774

  5. 40 CFR 1037.10 - How is this part organized?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standards of § 1037.105 or § 1037.106. (g) Subpart G of this part and 40 CFR part 1068 describe requirements.... Section 1037.601 describes how 40 CFR part 1068 applies for heavy-duty vehicles. (h) Subpart H of this.... (f) Subpart F of this part describes how to test your vehicles and perform emission...

  6. 40 CFR 1037.10 - How is this part organized?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards of § 1037.105 or § 1037.106. (g) Subpart G of this part and 40 CFR part 1068 describe requirements.... Section 1037.601 describes how 40 CFR part 1068 applies for heavy-duty vehicles. (h) Subpart H of this.... (f) Subpart F of this part describes how to test your vehicles and perform emission...

  7. 40 CFR 94.8 - Exhaust emission standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of this part. The manufacturer shall then set a family emission limit (FEL) which will serve as the standard for that engine family. The ABT provisions of subpart D of this part do not apply for Category...

  8. 40 CFR 94.8 - Exhaust emission standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of this part. The manufacturer shall then set a family emission limit (FEL) which will serve as the standard for that engine family. The ABT provisions of subpart D of this part do not apply for Category...

  9. 40 CFR 94.8 - Exhaust emission standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of this part. The manufacturer shall then set a family emission limit (FEL) which will serve as the standard for that engine family. The ABT provisions of subpart D of this part do not apply for Category...

  10. 40 CFR 94.8 - Exhaust emission standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of this part. The manufacturer shall then set a family emission limit (FEL) which will serve as the standard for that engine family. The ABT provisions of subpart D of this part do not apply for Category...

  11. Development of near-zero water consumption cement materials via the geopolymerization of tektites and its implication for lunar construction

    PubMed Central

    Wang, Kai-tuo; Tang, Qing; Cui, Xue-min; He, Yan; Liu, Le-ping

    2016-01-01

    The environment on the lunar surface poses some difficult challenges to building long-term lunar bases; therefore, scientists and engineers have proposed the creation of habitats using lunar building materials. These materials must meet the following conditions: be resistant to severe lunar temperature cycles, be stable in a vacuum environment, have minimal water requirements, and be sourced from local Moon materials. Therefore, the preparation of lunar building materials that use lunar resources is preferred. Here, we present a potential lunar cement material that was fabricated using tektite powder and a sodium hydroxide activator and is based on geopolymer technology. Geopolymer materials have the following properties: approximately zero water consumption, resistance to high- and low-temperature cycling, vacuum stability and good mechanical properties. Although the tektite powder is not equivalent to lunar soil, we speculate that the alkali activated activity of lunar soil will be higher than that of tektite because of its low Si/Al composition ratio. This assumption is based on the tektite geopolymerization research and associated references. In summary, this study provides a feasible approach for developing lunar cement materials using a possible water recycling system based on geopolymer technology. PMID:27406467

  12. Quantification of Bone Growth Rate Variability in Rats Exposed to Micro- (near zero G) and Macrogravity (2G)

    NASA Technical Reports Server (NTRS)

    Bromage, Timothy G.; Doty, Stephen B.; Smolyar, Igor; Holton, Emily

    1996-01-01

    Our stated primary objective is to quantify the growth rate variability of rat lamellar bone exposed to micro and macrogravity (2G). The primary significance of the proposed work is that an elegant method will be established that unequivocally characterizes the morphological consequences of gravitational factors on developing bone. The integrity of this objective depends upon our successful preparation of thin sections suitable for imaging individual bone lamellae, and our imaging and quantitation of growth rate variability in populations of lamellae from individual bone samples.

  13. 'Abnormal' angle response curves of TW/Rs for near zero tilt and high tilt channeling implants

    SciTech Connect

    Guo Baonian; Gossmann, Hans-Joachim; Toh, Terry; Colombeau, Benjamin; Todorov, Stan; Sinclair, Frank; Shim, Kyu-Ha; Henry, Todd

    2012-11-06

    Angle control has been widely accepted as the key requirement for ion implantation in semiconductor device processing. From an ion implanter point of view, the incident ion direction should be measured and corrected by suitable techniques, such as XP-VPS for the VIISta implanter platform, to ensure precision ion placement in device structures. So called V-curves have been adopted to generate the wafer-based calibration using channeling effects as the Si lattice steer ions into a channeling direction. Thermal Wave (TW) or sheet resistance (Rs) can be used to determine the minimum of the angle response curve. Normally it is expected that the TW and Rs have their respective minima at identical angles. However, the TW and Rs response to the angle variations does depend on factors such as implant species, dose, and wafer temperature. Implant damage accumulation effects have to be considered for data interpretation especially for some 'abnormal' V-curve data. In this paper we will discuss some observed 'abnormal' angle responses, such as a) TW/Rs reverse trend for Arsenic beam, 2) 'W' shape of Rs Boron, and 3) apparent TW/Rs minimum difference for high tilt characterization, along with experimental data and TCAD simulations.

  14. An AlGaN/GaN HEMT with enhanced breakdown and a near-zero breakdown voltage temperature coefficient

    NASA Astrophysics Data System (ADS)

    Xie, Gang; Tang, Cen; Wang, Tao; Guo, Qing; Zhang, Bo; Sheng, Kuang; Wai, Tung Ng

    2013-02-01

    An AlGaN/GaN high-electron mobility transistor (HEMT) with a novel source-connected air-bridge field plate (AFP) is experimentally verified. The device features a metal field plate that jumps from the source over the gate region and lands between the gate and drain. When compared to a similar size HEMT device with a conventional field plate (CFP) structure, the AFP not only minimizes the parasitic gate to source capacitance, but also exhibits higher OFF-state breakdown voltage and one order of magnitude lower drain leakage current. In a device with a gate to drain distance of 6 μm and a gate length of 0.8 μm, three times higher forward blocking voltage of 375 V was obtained at VGS = -5 V. In contrast, a similar sized HEMT with a CFP can only achieve a breakdown voltage no higher than 125 V using this process, regardless of device dimensions. Moreover, a temperature coefficient of 0 V/K for the breakdown voltage is observed. However, devices without a field plate (no FP) and with an optimized conventional field plate (CFP) exhibit breakdown voltage temperature coefficients of -0.113 V/K and -0.065 V/K, respectively.

  15. Self-Organized Near-Zero-Lag Synchronization Induced by Spike-Timing Dependent Plasticity in Cortical Populations

    PubMed Central

    Matias, Fernanda S.; Carelli, Pedro V.; Mirasso, Claudio R.; Copelli, Mauro

    2015-01-01

    Several cognitive tasks related to learning and memory exhibit synchronization of macroscopic cortical areas together with synaptic plasticity at neuronal level. Therefore, there is a growing effort among computational neuroscientists to understand the underlying mechanisms relating synchrony and plasticity in the brain. Here we numerically study the interplay between spike-timing dependent plasticity (STDP) and anticipated synchronization (AS). AS emerges when a dominant flux of information from one area to another is accompanied by a negative time lag (or phase). This means that the receiver region pulses before the sender does. In this paper we study the interplay between different synchronization regimes and STDP at the level of three-neuron microcircuits as well as cortical populations. We show that STDP can promote auto-organized zero-lag synchronization in unidirectionally coupled neuronal populations. We also find synchronization regimes with negative phase difference (AS) that are stable against plasticity. Finally, we show that the interplay between negative phase difference and STDP provides limited synaptic weight distribution without the need of imposing artificial boundaries. PMID:26474165

  16. Development of near-zero water consumption cement materials via the geopolymerization of tektites and its implication for lunar construction.

    PubMed

    Wang, Kai-Tuo; Tang, Qing; Cui, Xue-Min; He, Yan; Liu, Le-Ping

    2016-01-01

    The environment on the lunar surface poses some difficult challenges to building long-term lunar bases; therefore, scientists and engineers have proposed the creation of habitats using lunar building materials. These materials must meet the following conditions: be resistant to severe lunar temperature cycles, be stable in a vacuum environment, have minimal water requirements, and be sourced from local Moon materials. Therefore, the preparation of lunar building materials that use lunar resources is preferred. Here, we present a potential lunar cement material that was fabricated using tektite powder and a sodium hydroxide activator and is based on geopolymer technology. Geopolymer materials have the following properties: approximately zero water consumption, resistance to high- and low-temperature cycling, vacuum stability and good mechanical properties. Although the tektite powder is not equivalent to lunar soil, we speculate that the alkali activated activity of lunar soil will be higher than that of tektite because of its low Si/Al composition ratio. This assumption is based on the tektite geopolymerization research and associated references. In summary, this study provides a feasible approach for developing lunar cement materials using a possible water recycling system based on geopolymer technology. PMID:27406467

  17. Development of near-zero water consumption cement materials via the geopolymerization of tektites and its implication for lunar construction

    NASA Astrophysics Data System (ADS)

    Wang, Kai-Tuo; Tang, Qing; Cui, Xue-Min; He, Yan; Liu, Le-Ping

    2016-07-01

    The environment on the lunar surface poses some difficult challenges to building long-term lunar bases; therefore, scientists and engineers have proposed the creation of habitats using lunar building materials. These materials must meet the following conditions: be resistant to severe lunar temperature cycles, be stable in a vacuum environment, have minimal water requirements, and be sourced from local Moon materials. Therefore, the preparation of lunar building materials that use lunar resources is preferred. Here, we present a potential lunar cement material that was fabricated using tektite powder and a sodium hydroxide activator and is based on geopolymer technology. Geopolymer materials have the following properties: approximately zero water consumption, resistance to high- and low-temperature cycling, vacuum stability and good mechanical properties. Although the tektite powder is not equivalent to lunar soil, we speculate that the alkali activated activity of lunar soil will be higher than that of tektite because of its low Si/Al composition ratio. This assumption is based on the tektite geopolymerization research and associated references. In summary, this study provides a feasible approach for developing lunar cement materials using a possible water recycling system based on geopolymer technology.

  18. Accurate path integral molecular dynamics simulation of ab-initio water at near-zero added cost

    NASA Astrophysics Data System (ADS)

    Elton, Daniel; Fritz, Michelle; Soler, José; Fernandez-Serra, Marivi

    It is now established that nuclear quantum motion plays an important role in determining water's structure and dynamics. These effects are important to consider when evaluating DFT functionals and attempting to develop better ones for water. The standard way of treating nuclear quantum effects, path integral molecular dynamics (PIMD), multiplies the number of energy/force calculations by the number of beads, which is typically 32. Here we introduce a method whereby PIMD can be incorporated into a DFT molecular dynamics simulation at virtually zero cost. The method is based on the cluster (many body) expansion of the energy. We first subtract the DFT monomer energies, using a custom DFT-based monomer potential energy surface. The evolution of the PIMD beads is then performed using only the more-accurate Partridge-Schwenke monomer energy surface. The DFT calculations are done using the centroid positions. Various bead thermostats can be employed to speed up the sampling of the quantum ensemble. The method bears some resemblance to multiple timestep algorithms and other schemes used to speed up PIMD with classical force fields. We show that our method correctly captures some of key effects of nuclear quantum motion on both the structure and dynamics of water. We acknowledge support from DOE Award No. DE-FG02-09ER16052 (D.E.) and DOE Early Career Award No. DE-SC0003871 (M.V.F.S.).

  19. Development of a lightweight near-zero CTE optical bench for the Wide-Field Camera 3 instrument

    NASA Astrophysics Data System (ADS)

    Holz, Jill M.; Kunt, Cengiz; Lashley, Chris; McGuffey, Douglas B.

    2003-02-01

    The design and development of an optical bench (OB) for Wide Field Camera 3 (WFC3), a next generation science instrument for the Hubble Space Telescope (HST) has proven a challenging task. WFC3 will replace Wide Field Planetary Camera 2 (WF/PC 2) during the next servicing mission of the HST in 2004. The WFC3 program is re-using much of the hardware from WF/PC 1, returned from the First Servicing Mission, which has added complexity to the program. This posed some significant packaging challenges, further complicated by WFC3 utilizing two, separate optical channels. The WF/PC 1 optical bench could not house the additional optical components, so a new bench was developed. The new bench had to be designed to accommodate the sometimes-conflicting requirements of the two channels, which operate over a wavelength range of 200nm to 1800nm, from Near Ultraviolet to Near Infrared. In addition, the bench had to interface to the reused WF/PC 1 hardware, which was not optimized for this mission. To aid in the design of the bench, the team used software tools to merge structural, thermal and optical models to obtain performance (STOP) of the optical systems in operation. Several iterations of this performance analysis were needed during the design process to verify the bench would meet requirements. The fabrication effort included a rigorous material characterization program and significant tooling. After assembly, the optical bench underwent an extensive qualification program to prove the design and manufacturing processes. This paper provides the details of the design and development process of this highly optimized optical bench.

  20. Enhanced SOA formation from mixed anthropogenic and biogenic emissions during the CARES campaign

    SciTech Connect

    Shilling, John E.; Zaveri, Rahul A.; Fast, Jerome D.; Kleinman, Lawrence I.; Alexander, M. L.; Canagaratna, Manjula R.; Fortner, Edward; Hubbe, John M.; Jayne, John T.; Sedlacek, Art; Setyan, Ari; Springston, S.; Worsnop, Douglas R.; Zhang, Qi

    2013-02-21

    The CARES campaign was conducted during June, 2010 in the vicinity of Sacramento, California to study aerosol formation and aging in a region where anthropogenic and biogenic emissions regularly mix. Here, we describe measurements from an Aerodyne High Resolution Aerosol Mass Spectrometer (AMS), an Ionicon Proton Transfer Reaction Mass Spectrometer (PTR-MS), and trace gas detectors (CO, NO, NOx) deployed on the G-1 research aircraft to investigate ambient gas- and particle-phase chemical composition. AMS measurements showed that the particle phase is dominated by organic aerosol (OA) (85% on average) with smaller concentrations of sulfate (5%), nitrate (6%) and ammonium (3%) observed. PTR-MS data showed that isoprene dominated the biogenic volatile organic compound concentrations (BVOCs), with monoterpene concentrations generally below the detection limit. Using two different metrics, median OA concentrations and the slope of plots of OA vs. CO concentrations (i.e., ΔOA/ΔCO), we contrast organic aerosol evolution on flight days with different prevailing meteorological conditions to elucidate the role of anthropogenic and biogenic emissions on OA formation. Airmasses influenced predominantly by biogenic emissions had median OA concentrations of 2.9 μg/m3 and near zero ΔOA/ΔCO. Those influenced predominantly by anthropogenic emissions had median OA concentrations of 4.7 μg/m3 and ΔOA/ΔCO ratios of 35 - 44 μg/m3ppmv. When biogenic and anthropogenic emissions mix, OA levels are dramatically enhanced with median OA concentrations of 11.4 μg/m3 and ΔOA/ΔCO ratios of 77 - 157 μg/m3ppmv. Taken together, our observations show that production of OA is enhanced when anthropogenic emissions from Sacramento mix with isoprene-rich air from the foothills. A strong, non-linear dependence of SOA yield from isoprene is the mechanistic explanation for this enhancement most consistent with both the gas- and particle-phase data. If these observations are found to be robust