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Sample records for plasmon-coupled emission spce

  1. A proposal and a theoretical analysis of an enhanced surface plasmon coupled emission structure for single molecule detection

    Science.gov (United States)

    Uddin, Shiekh Zia; Tanvir, Mukhlasur Rahman; Talukder, Muhammad Anisuzzaman

    2016-05-01

    We propose a structure that can be used for enhanced single molecule detection using surface plasmon coupled emission (SPCE). In the proposed structure, instead of a single metal layer on the glass prism of a typical SPCE structure for fluorescence microscopy, a metal-dielectric-metal structure is used. We theoretically show that the proposed structure significantly decreases the excitation volume of the fluorescently labeled sample, and simultaneously increases the peak SPCE intensity and SPCE power. Therefore, the signal-to-noise ratio and sensitivity of an SPCE based fluorescence microscopy system can be significantly increased using the proposed structure, which will be helpful for enhanced single molecule detection, especially, in a less pure biological sample.

  2. C60 as an active smart spacer material on silver thin film substrates for enhanced surface plasmon coupled emission.

    Science.gov (United States)

    Mulpur, Pradyumna; Podila, Ramakrishna; Ramamurthy, Sai Sathish; Kamisetti, Venkataramaniah; Rao, Apparao M

    2015-04-21

    In this study, we present the use of C60 as an active spacer material on a silver (Ag) based surface plasmon coupled emission (SPCE) platform. In addition to its primary role of protecting the Ag thin film from oxidation, the incorporation of C60 facilitated the achievement of a 30-fold enhancement in the emission intensity of rhodamine B (RhB) fluorophore. The high signal yield was attributed to the unique π-π interactions between C60 thin films and RhB, which enabled efficient transfer of energy of RhB emission to Ag plasmon modes. Furthermore, minor variations in the C60 film thickness yielded large changes in the enhancement and angularity properties of the SPCE signal, which can be exploited for sensing applications. Finally, the low-cost fabrication process of the Ag-C60 thin film stacks render C60 based SPCE substrates ideal, for the economic and simplistic detection of analytes.

  3. Flexible Ag-C60 nano-biosensors based on surface plasmon coupled emission for clinical and forensic applications.

    Science.gov (United States)

    Mulpur, Pradyumna; Yadavilli, Sairam; Mulpur, Praharsha; Kondiparthi, Neeharika; Sengupta, Bishwambhar; Rao, Apparao M; Podila, Ramakrishna; Kamisetti, Venkataramaniah

    2015-10-14

    The relatively low sensitivity of fluorescence detection schemes, which are mainly limited by the isotropic nature of fluorophore emission, can be overcome by utilizing surface plasmon coupled emission (SPCE). In this study, we demonstrate directional emission from fluorophores on flexible Ag-C60 SPCE sensor platforms for point-of-care sensing, in healthcare and forensic sensing scenarios, with at least 10 times higher sensitivity than traditional fluorescence sensing schemes. Adopting the highly sensitive Ag-C60 SPCE platform based on glass and novel low-cost flexible substrates, we report the unambiguous detection of acid-fast Mycobacterium tuberculosis (Mtb) bacteria at densities as low as 20 Mtb mm(-2); from non-acid-fast bacteria (e.g., E. coli and S. aureus), and the specific on-site detection of acid-fast sperm cells in human semen samples. In combination with the directional emission and high-sensitivity of SPCE platforms, we also demonstrate the utility of smartphones that can replace expensive and cumbersome detectors to enable rapid hand-held detection of analytes in resource-limited settings; a much needed critical advance to biosensors, for developing countries.

  4. Carbon nanotubes as novel spacer materials on silver thin-films for generating superior fluorescence enhancements via surface plasmon coupled emission

    Science.gov (United States)

    Mulpur, Pradyumna; Podila, Ramakrishna; Rao, Apparao M.; Kamisetti, Venkataramaniah

    2016-06-01

    In this study, we report the first time implementation of single/multi-walled carbon nanotubes, as novel spacer materials, on a silver (Ag) thin-film based surface plasmon coupled emission (SPCE) platform. The engineered Ag-CNT SPCE substrates enabled the realization of up to ∼10-fold enhancement in fluorescence signal intensity, of the rhodamine b dye. This study addresses the issue that, while many of the biochemical sensing strategies are based on fluorescence, they are all fundamentally limited by the isotropic nature of the phenomenon that results in low signal collection efficiency (50% signal collection efficiency. Considering the easy functionalization of these carbon nano-allotropes, and their high sensitivity; the economical Ag-CNT SPCE platforms can be effectively extended towards sensing applications.

  5. Distinguishing between whole cells and cell debris using surface plasmon coupled emission (Conference Presentation)

    Science.gov (United States)

    Talukder, Muhammad A.; Menyuk, Curtis R.; Kostov, Yordan

    2017-02-01

    Distinguishing between intact cells, dead but still whole cells, and cell debris is an important but difficult task in life sciences. The most common way to identify dead cells is using a cell-impermeant DNA binding dye, such as propidium iodide. A healthy living cell has an intact cell membrane and will act as a barrier to the dye so that it cannot enter the cell. A dead cell has a compromised cell membrane, and it will allow the dye into the cell to bind to the DNA and become fluorescent. The dead cells therefore will be positive and the live cells will be negative. The dead cells later deteriorate quickly into debris. Different pieces of debris from a single cell can be incorrectly identified as separate dead cells. Although a flow cytometer can quickly perform numerous quantitative, sensitive measurements on each individual cell to determine the viability of cells within a large, heterogeneous population, it is bulky, expensive, and only large hospitals and laboratories can afford them. In this work, we show that the distance-dependent coupling of fluorophore light to surface plasmon coupled emission (SPCE) from fluorescently-labeled cells can be used to distinguish whole cells from cell debris. Once the fluorescent labels are excited by a laser, the fluorescently-labeled whole cells create two distinct intensity rings in the far-field, in contrast to fluorescently-labeled cell debris, which only creates one ring. The distinct far-field patterns can be captured by camera and used to distinguish between whole cells and cell debris.

  6. Miniaturization of surface plasmon coupled emission spectrofluorimeter and its performance analysis%表面等离子体耦合荧光装置小型化改进与性能分析

    Institute of Scientific and Technical Information of China (English)

    谢堂堂; 刘晓庆; 蔡伟鹏; 曹烁晖; 刘倩; 林国春; 李耀群

    2012-01-01

    A miniature spectrofluorimeter for surface plasmon coupled emission (SPCE) technique has been developed using a laser pointer as the light source. Here we investigate its performance by measuring SPCE from sulforhodamine 101 doped PVA. The fluorescence signal on the prism side emitted at a sharply directional angle of 47° and was definitely p-polarized with different wavelengths appearing at different angles. It is demonstrated that this laboratory-constructed spectrofluorimeter is able to meet the general test requirements of SPCE technique. Compared with the previously reported devices,our spectrofluorimeter has many advantages such as simple, stable performance and low cost.%搭建了结构紧凑简单、性能稳定、成本低廉的表面等离子体耦合荧光(SPCE)小型装置.通过对罗丹明S101样品荧光信号角度分布和偏振性的测试,分析了该小型装置的仪器性能,结果令人满意.该装置完全能够满足SPCE一般的测试要求,可望推广使用.

  7. Surface Plasmon-coupled Emission of Multicolor Quantum Dots%多色量子点表面等离子体耦合荧光发射性质

    Institute of Scientific and Technical Information of China (English)

    刘晓庆; 刘倩; 谢凯信; 曹烁晖; 蔡伟鹏; 李耀群

    2012-01-01

    Aqueous CdTe quantum dots(QDs) were synthesized employing thiols as stabilizing ligands and their emission wavelengths could be tuned by controlling the reflux time.Surface plasmon-coupled emission(SPCE) properties of multicolor CdTe QDs were studied by using a laboratory-built multifunctional spectrofluorimeter.To fabricate a CdTe QDs-doped complete film onto the surface of continuous thin metal films,CdTe QDs were spin-coated at 3000 r/min with poly(vinyl alcohol)(PVA) solution of various concentrations.For SPCE measurements,the spin-coated slides were attached to a semi-cylindrical prism made of fused silica with a refractive-index-matching fluid and then positioned on a precise rotary stage that allowed for excitation and emission observation at any angle relative to the vertical axis of the stage.For excitation,we used the reverse Kretschmann(RK) configuration and the incident light was normal to the sample interface.The spectra were measured using a monochromator equipped with a photomultiplier tube.The experimental results showed CdTe QDs located nearby continuous thin metal film could be excited using either blue(473 nm) or green(532 nm) laser as a result of their broad excitations and their emissions resulting from the surface plasmon coupling were strongly directional,highly polarized and closely related to sample thickness.Because of the wavelength-resolution property of SPCE,CdTe QDs with different emission wavelengths were found to emit at different fixed angles,longer wavelengths corresponding to smaller angles.The free space emission spectra of 720 nm and 630 nm CdTe QDs in a mixture were overlapped and could not be separated at any detection angle.However,owing to the unique wavelength resolution ability of SPCE,the spectra of 720 nm and 630 nm CdTe QDs were obtained at 43° and 51o on the prism side,respectively.The determination of each component of the mixtures of CdTe QDs was achieved by changing the detection angle to avoid spectral overlap

  8. Ag-protein plasmonic architectures for surface plasmon-coupled emission enhancements and Fabry-Perot mode-coupled directional fluorescence emission

    Science.gov (United States)

    Badiya, Pradeep Kumar; Patnaik, Sai Gourang; Srinivasan, Venkatesh; Reddy, Narendra; Manohar, Chelli Sai; Vedarajan, Raman; Mastumi, Noriyoshi; Belliraj, Siva Kumar; Ramamurthy, Sai Sathish

    2017-10-01

    We report the use of silver decorated plant proteins as spacer material for augmented surface plasmon-coupled emission (120-fold enhancement) and plasmon-enhanced Raman scattering. We extracted several proteins from different plant sources [Triticum aestivum (TA), Aegle marmelos (AM), Ricinus communis (RC), Jatropha curcas (JC) and Simarouba glauca (SG)] followed by evaluation of their optical properties and simulations to rationalize observed surface plasmon resonance. Since the properties exhibited by protein thin films is currently gaining research interest, we have also carried out simulation studies with Ag-protein biocomposites as spacer materials in metal-dielectric-metal planar microcavity architecture for guided emission of Fabry-Perot mode-coupled fluorescence.

  9. Surface plasmon coupled emission studies on engineered thin film hybrids of nano α−Al{sub 2}O{sub 3} on silver

    Energy Technology Data Exchange (ETDEWEB)

    Mulpur, Pradyumna; Chunduri, Avinash; Rattan, Tanu Mimani; Kamisetti, Venkataramaniah [Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh, India 515134 (India); Lingam, Kiran; Rao, Apparao M. [Department of Physics and Astronomy, 202C Kinard Laboratory, Clemson University, Clemson, SC 29634 (United States)

    2014-01-28

    We report the first time engineering and fabrication of a novel thin film hybrid of nano α-alumina doped in a polyvinyl alcohol (PVA) matrix along with rhodamine b (Rh.B) on a silver thin film. Silver films of 50 nm thickness on glass slides were fabricated by thermal evaporation. Nano α-alumina was synthesized through the combustion route and characterized by XRD. The α-alumina was dispersed in the PVA-Rh.B matrix by tip sonication. The resultant solution was spin coated on the Ag thin film at 3000 rpm to generate an overcoat of ∼30 nm. We have designed and constructed an opto-mechanical setup for performing the SPCE studies. Excitation with a 532 nm continuous laser, led to the coupling of the energy of Rh.B emission to the surface plasmon modes of silver. The emission @ 580 nm was recorded using an Ocean Optics(copyright, serif) fiber optic spectrometer. Calculation of the ratio of signal intensity between the directional SPCE and isotropic fluorescence gives us the factor of signal enhancements which SPCE offers. We report an '8 fold' signal enhancement attributed to SPCE arising from the metal oxide doped thin film hybrid. We observed only a '5 fold' signal enhancement in the case of a thin film hybrid without α-alumina. The emission was also 92% P-polarized which is in coherence with the theory of SPCE. The greater degree of signal enhancement observed in the α-alumina doped thin film substrate can be attributed to the surface roughness which alumina offers to silver, which along with the porous nature of alumina enables a greater degree of adsorption of Rh.B which results in a higher emission intensity. Computational modeling was also performed, based on surface plasmon resonance (SPR) calculations to provide theoretical background to observed experimental data. The α-alumina thin film hybrid can be extended as an economical sensing platform towards the high sensitive detection of analytes.

  10. Surface Plasmon-Coupled Enhanced Transmission

    CERN Document Server

    Djalalian-Assl, Amir

    2016-01-01

    Investigations show a strong coupling between a dipole and the surface wave occurs when a dipole is positioned within 10 nm from a metallic surface. This is in contrast to what was thought previously with surface plasmon-coupled emission where the emission of a dipole was claimed to be quenched when positioned within 10 nm from a metallic surface. In fact, the quenching distance is related to the energy transfer between the dipole that acts as a donor and the metallic surface acting as an acceptor. For distances less 10 nm away from a flat metallic surface a total energy transfer occurs, producing evanescent surface waves that are plasmonic in nature. When investigating a metallic nanohole on an optically dense substrate (such as diamond with NV-), the scattering occured preferentially from the diamond substrate towards the air for dipole distances less 10 nm from the aperture. In addition, an enhancement to the dipole's radiative decay rate was observed. The relationship between an emitter and a nearby reson...

  11. Enhancement of ZnO ultraviolet emission by surface plasmon coupling using a rough NiSi2 layer synthesized by ion implantation

    Institute of Scientific and Technical Information of China (English)

    Tan Hairen; You Jingbi; Zhang Shuguang; Gao Hongli; Yin Zhigang; Bai Yiming; Zhang Xiulan; Zhang Xingwang; Qu Sheng

    2011-01-01

    The calculation results of the surface plasmon (SP) energy and Purcell factor of ZnO/NiSi2 demonstrate the possibility of using NiSi2 to enhance the UV emission of ZnO by SP coupling.Experimentally,ZnO films were deposited on NiSi2 layers synthesized by ion implantation,and the roughness of the NiSi2 layers spans a large range from 3 to 38 nm,providing favorable conditions for investigating SP-mediated emission.An 1 1-fold emission enhancement from the ZnO film on the roughest NiSi2 layer was obtained,which indicates the possibility that metal silicide layers can be used both as an electrical contact and for emission enhancement.

  12. High power terahertz emission from a single gate AlGaN/GaN field effect transistor with periodic Ohmic contacts for plasmon coupling

    Science.gov (United States)

    Onishi, Toshikazu; Tanigawa, Tatsuya; Takigawa, Shinichi

    2010-08-01

    We report on room temperature terahertz (THz) emission by a single, short gate AlGaN/GaN field effect transistor with grating Ohmic contacts. The fingers of metal contacts are fabricated at the nanoscale in length and spacing in order to work as a radiation coupler of electron plasmons in the THz range. Spectrum analysis revealed a broadband emission centered at 1.5 THz with a controlled polarization by the grating contacts. The measured output power is linearly increased with the drain input power and reached up to 1.8 μW.

  13. Photon tunneling via surface plasmon coupling

    Science.gov (United States)

    Passian, A.; Wig, A.; Lereu, A. L.; Meriaudeau, F.; Thundat, T.; Ferrell, T. L.

    2004-10-01

    The measurement of a photonic signal via plasmon-plasmon coupling in curved thin metal films is presented. In domains of subwavelength dimension, we calculate the resonant dispersion relations by modeling the curved thin film as a single sheeted hyperboloid of revolution. We show that several such surface modes are accessible optically at frequencies below the plasma frequency of the metal.

  14. Optical modulator based on propagating surface plasmon coupled fluorescent thin film: proof-of-concept studies

    Science.gov (United States)

    Cao, Shuo-Hui; Wang, Zheng-Chuang; Weng, Yu-Hua; Xie, Kai-Xin; Chen, Min; Zhai, Yan-Yun; Li, Yao-Qun

    2017-06-01

    We demonstrate that the propagating surface plasmon coupled fluorescent thin film can be utilized as a fluorescence modulator to mimic multiple representative Boolean logic operations. Surface plasmon mediated fluorescence presents characteristic properties including directional and polarized emission, which hold the feasibility in creating a universal optical modulator. In this work, through constructing the thin layer with the specific thickness, surface plasmon mediated fluorescence can be modulated with an ON-OFF ratio by more than 5-fold, under a series of coupling configurations.

  15. Quantum analysis of plasmonic coupling between quantum dots and nanoparticles

    Science.gov (United States)

    Ahmad, SalmanOgli

    2016-10-01

    In this study, interaction between core-shells nanoparticles and quantum dots is discussed via the full-quantum-theory method. The electromagnetic field of the nanoparticles is derived by the quasistatic approximation method and the results for different regions of the nanoparticles are quantized from the time-harmonic to the wave equation. Utilizing the optical field quantization, the nanoparticles' and quantum dots' deriving amplitudes contributing to the excitation waves are determined. In the current model, two counterpropagating waves with two different frequencies are applied. We derived the Maxwell-Bloch equations from the Heisenberg-Langevin equations; thus the nanoparticles-quantum dots interaction is perused. Moreover, by full quantum analyzing of the analytical expression, the quantum-plasmonic coupling relation and the Purcell factor are achieved. We show that the spontaneous emission of quantum dots can be dramatically manipulated by engineering the plasmon-plasmon interaction in the core-shells nanoparticles. This issue is a very attractive point for designing a wide variety of quantum-plasmonic sensors. Through the investigation of the nanoparticle plasmonic interaction effects on absorbed power, the results show that the nanoparticles' and quantum dots' absorption saturation state can be switched to each other just by manipulation of their deriving amplitudes. In fact, we manage the interference between the two waves' deriving amplitudes just by the plasmonic interactions effect.

  16. Characteristics of surface plasmon coupled quantum well infrared photodetectors

    Science.gov (United States)

    Hsu, Wei-Cheng; Ling, Hong-Shi; Wang, Shiang-Yu; Lee, Chien-Ping

    2017-06-01

    Quantum Well Infrared Photodetectors (QWIPs) with different structures were characterized for the study of surface plasmon wave coupling. Detailed comparisons between surface plasmon coupled and etched grating coupled devices were investigated. A bias dependence for the enhancement of the responsivity of surface plasmon coupled devices was found, especially for the samples with non-uniform quantum wells. The non-uniform QWIPs with surface plasmon coupling showed an asymmetric enhancement with respect to the bias directions. Stronger enhancements were shown under the biases when a higher effective electric field region is close to the collector. The change of the photocarrier escape probability due to the narrow coupling bandwidth of the surface plasmon wave is attributed to this unexpected bias dependence.

  17. Ubiquitous electron-plasmon coupling in doped semiconductors

    Science.gov (United States)

    Caruso, Fabio; Giustino, Feliciano

    The interplay between electrons and bosonic excitations [as, e.g., phonons, collective charge-density fluctuations (plasmons), and magnons] is pervasive in matter and underlies an extremely broad spectrum of physical phenomena, as, for instance, current dissipation, superconductivity, hot-carrier thermalisation, and band structure replicas. At variance with phonons, however, questions pertaining the strength of electron-plasmon coupling in solids are still awaiting further investigations. We developed and implemented a first-principles theory of electron-plasmon coupling based on many-body perturbation theory. Our first-principles calculations reveal that electron-plasmon coupling alters ubiquitously the dynamical and optical properties of semiconductors at high doping concentrations. This behaviour stems from the emergence of low-energy extrinsic plasmons which may couple electronic states in the vicinity of the Fermi energy

  18. UV Nano Lights - Nonlinear Quantum Dot-Plasmon Coupling

    Science.gov (United States)

    2016-06-20

    AFRL-AFOSR-JP-TR-2016-0072 UV Nano-Lights - Nonlinear Quantum Dot-Plasmon Coupling Eric Waclawik QUEENSLAND UNIVERSITY OF TECHNOLOGY Final Report 06...Final 3.  DATES COVERED (From - To)  03 Feb 2014 to 02 Feb 2016 4.  TITLE AND SUBTITLE UV Nano-Lights - Nonlinear Quantum Dot-Plasmon Coupling 5a...CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-14-1-4056 5c.   PROGRAM ELEMENT NUMBER 61102F 6.  AUTHOR(S) Eric Waclawik 5d.  PROJECT NUMBER 5e.  TASK NUMBER 5f

  19. Plasmon coupling in vertical split-ring resonator metamolecules

    Science.gov (United States)

    Wu, Pin Chieh; Hsu, Wei-Lun; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Liu, Ai Qun; Zheludev, Nikolay I.; Sun, Greg; Tsai, Din Ping

    2015-01-01

    The past decade has seen a number of interesting designs proposed and implemented to generate artificial magnetism at optical frequencies using plasmonic metamaterials, but owing to the planar configurations of typically fabricated metamolecules that make up the metamaterials, the magnetic response is mainly driven by the electric field of the incident electromagnetic wave. We recently fabricated vertical split-ring resonators (VSRRs) which behave as magnetic metamolecules sensitive to both incident electric and magnetic fields with stronger induced magnetic dipole moment upon excitation in comparison to planar SRRs. The fabrication technique enabled us to study the plasmon coupling between VSRRs that stand up side by side where the coupling strength can be precisely controlled by varying the gap in between. The resulting wide tuning range of these resonance modes offers the possibility of developing frequency selective functional devices such as sensors and filters based on plasmon coupling with high sensitivity. PMID:26043931

  20. Monitoring of receptor dimerization using plasmonic coupling of gold nanoparticles.

    Science.gov (United States)

    Crow, Matthew J; Seekell, Kevin; Ostrander, Julie H; Wax, Adam

    2011-11-22

    The dimerization of receptors on the cell membrane is an important step in the activation of cell signaling pathways. Several methods exist for observing receptor dimerization, including coimmunoprecipitation, chemical cross-linking, and fluorescence resonance energy transfer (FRET). These techniques are limited in that only FRET is appropriate for live cells, but even that method suffers from photobleaching and bleed-through effects. In this study, we implement an alternative method for the targeting of HER-2 homodimer formation based on the plasmonic coupling of gold nanoparticles functionalized with HER-2 Ab. In the presented studies, SK-BR-3 cells, known to overexpress HER-2, are labeled with these nanoparticles and receptor colocalization is observed using plasmonic coupling. HER-2 targeted nanoparticles bound to these cells exhibit a peak resonance that is significantly red-shifted relative to those bound to similar receptors on A549 cells, which have significantly lower levels of HER-2 expression. This significant red shift indicates plasmonic coupling is occurring and points to a new avenue for assessing dimerization by monitoring their colocalization. To determine that dimerization is occurring, the refractive index of the nanoenvironment of the labels is assessed using a theoretical analysis based on the Mie coated sphere model. The results indicate scattering by single, isolated nanoparticles for the low HER-2 expressing A549 cell line, but the scattering observed for the HER-2 overexpressing SK-BR-3 cell line may only be explained by plasmonic-coupling of proximal nanoparticle pairs. To validate the conformation of nanoparticles bound to HER-2 receptors undergoing dimerization, discrete dipole approximation (DDA) models are used to assess spectra of scattering by coupled nanoparticles. Comparison of the experimental results with theoretical models indicates that NP dimers are formed for the labeling of SK-BR-3 cells, suggesting that receptor

  1. Plasmonic coupling in single flower-like gold nanoparticle assemblies

    Institute of Scientific and Technical Information of China (English)

    Yi Luo; Lacie Dube; Yadong Zhou; Shengli Zou; Jing Zhao

    2016-01-01

    Localized surface plasmon resonance (LSPR) arises when light interacts with metallic nanoparticles (NPs). When nanoparticles (NPs) assemble together, the plasmon coupling effect between the NPs often leads to new features in the LSPR of the assembled structure. Understanding the plasmon coupling in the complex assemblies will greatly benefit the development of new plasmonic devices. Here we demonstrate the fabrication of a 3D structure using two different sized Au NPs as building blocks. This 3D structure was achieved by manipulating the binding efficiency of ligands linking the NPs, and proper choice of the NP size. The assembled structure is flower-like structure, with one 130 nm Au NP in the center, and several 40 nm Au NPs attaching as“petals”. Single particle dark-field scattering measurements of the individual assemblies were performed, together with electrodynamics simulations. The experimental and theoretical studies show that, the plasmonic coupling lead to broadening of the LSPR and additional peaks, depending on the number and 3D arrangement of the 40 nm NPs around the center 130 nm NP.

  2. Plasmonic coupling in single flower-like gold nanoparticle assemblies

    Directory of Open Access Journals (Sweden)

    Yi Luo

    2016-10-01

    Full Text Available Localized surface plasmon resonance (LSPR arises when light interacts with metallic nanoparticles (NPs. When nanoparticles (NPs assemble together, the plasmon coupling effect between the NPs often leads to new features in the LSPR of the assembled structure. Understanding the plasmon coupling in the complex assemblies will greatly benefit the development of new plasmonic devices. Here we demonstrate the fabrication of a 3D structure using two different sized Au NPs as building blocks. This 3D structure was achieved by manipulating the binding efficiency of ligands linking the NPs, and proper choice of the NP size. The assembled structure is flower-like structure, with one 130 nm Au NP in the center, and several 40 nm Au NPs attaching as “petals”. Single particle dark-field scattering measurements of the individual assemblies were performed, together with electrodynamics simulations. The experimental and theoretical studies show that, the plasmonic coupling lead to broadening of the LSPR and additional peaks, depending on the number and 3D arrangement of the 40 nm NPs around the center 130 nm NP.

  3. Controlling plasmon coupling in biomolecule-linked metal nanoparticle assemblies

    Science.gov (United States)

    Sebba, David S.

    Molecular control of plasmon coupling is investigated in biomolecule-linked nanoparticle assemblies in two-particle, small cluster, and extended network formats. The relationship between structure and optical properties is explored through comparison of measured spectra with simulated spectra calculated using structural models based upon measured structural parameters. A variety of techniques are used to characterize nanoparticle assemblies, including ensemble extinction and elastic scattering spectroscopy, single-assembly scattering spectroscopy, transmission electron microscopy, and dynamic light scattering. Initially, molecular control of plasmon coupling is investigated in ˜100 nm assemblies composed of 13 nm gold "satellite" particles tethered by duplex DNA to a 50 nm gold "core" particle. Comparison of core-satellite assemblies formed with duplex DNA tethers of varying length demonstrates that, while core-satellite separation is controlled by the number of base pairs in the DNA tether, structural properties such as core:satellite ratio and yield are independent of DNA tether length. Thus, plasmon coupling within these assemblies is determined by the number of base pairs in the duplex DNA tether; compact assemblies in which tethers are composed of fewer base pairs exhibit plasmon bands that are red-shifted relative to the bands of extended assemblies, indicating increased plasmon coupling in the compact assemblies. Subsequently, core-satellite assemblies are formed with reconfigurable DNA nanostructure tethers that modulate interparticle separation in response to a molecular stimulus. Assembly reconfiguration from a compact to an extended state results in blue-shifting of the assembly plasmon resonance, indicating reduced interparticle coupling and lengthening of the core-satellite tether. Comparison between measured and simulated spectra revealed a close correspondence and provided validation of the structural models that link assembly plasmonic properties

  4. Surface plasmon coupled chemiluminescence during adsorption of oxygen on magnesium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, Ulrich [Interdisciplinary Center for the Analytics on the Nanoscale (ICAN) and Center for Nanointegration Duisburg-Essen (CENIDE), Carl-Benz-Str. 199, 47057 Duisburg (Germany); Nienhaus, Hermann, E-mail: hermann.nienhaus@uni-due.de [Faculty of Physics, University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE), Lotharstr. 1, 47048 Duisburg (Germany)

    2015-12-28

    The dissociative adsorption of oxygen molecules on magnesium surfaces represents a non-adiabatic reaction exhibiting exoelectron emission, chemicurrent generation, and weak chemiluminescence. Using thin film Mg/Ag/p-Si(111) Schottky diodes with 1 nm Mg on a 10-60 nm thick Ag layer as 2π-photodetectors, the chemiluminescence is internally detected with a much larger efficiency than external methods. The chemically induced photoyield shows a maximum for a Ag film thickness of 45 nm. The enhancement is explained by surface plasmon coupled chemiluminescence, i.e., surface plasmon polaritons are effectively excited in the Ag layer by the oxidation reaction and decay radiatively leading to the observed photocurrent. Model calculations of the maximum absorption in attenuated total reflection geometry support the interpretation. The study demonstrates the extreme sensitivity and the practical usage of internal detection schemes for investigating surface chemiluminescence.

  5. Exciton-plasmon Coupling and Electromagnetically Induced Transparency in Monolayer Semiconductors Hybridized with Ag Nanoparticles

    CERN Document Server

    Weijie, Zhao; Bo, Liu; Ivan, Verzhbitskiy; Shisheng, Li; Francesco, Giustiniano; Daichi, Kozawa; Ping, Loh Kian; Kazunari, Matsuda; Koichi, Okamoto; Rupert, Oulton F; Goki, Eda

    2016-01-01

    Hybrid systems of excitons strongly coupled to localized surface plasmons supported by metallic nanoparticles define a new approach to control light-matter interactions. Here, we report exciton-plasmon coupling in two-dimensional (2D) semiconductors, such as MoS2 and WS2, hybridized with silver nanoparticles. Prominent photoluminescence enhancement in monolayer MoS2 was observed with localized surface plasmon resonance (LSPR) tuned to the exciton resonance. By tuning the excitation energy, the contributions from near field enhancement and radiative emission rate enhancement via Purcell effect were resolved. Strong coherent dipole-dipole coupling between excitons and LSPR in resonant condition manifests as an electromagnetically induced transparency window in the extinction spectra of the localized surface plasmon. In this strong coupling regime a new quasi-particle, known as a plexciton, is expected to exhibit distinct properties, which exist in neither of the original particles. Our results demonstrate that ...

  6. Surface plasmon coupling dynamics in InGaN/GaN quantum-well structures and radiative efficiency improvement

    DEFF Research Database (Denmark)

    Fadil, Ahmed; Iida, Daisuke; Chen, Yuntian

    2014-01-01

    for InGaN/GaN quantum-well structures. By using a thin SiN dielectric layer between Ag and GaN we manage to modify and improve surface plasmon coupling effects, and we attribute this to the improved scattering of the nanoparticles at the quantum-well emission wavelength. The results are interpreted using...... numerical simulations, where absorption and scattering cross-sections are studied for different sized particles on GaN and GaN/SiN substrates....

  7. Surface Plasmon Coupling and Control Using Spherical Cap Structures

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yu; Joly, Alan G.; Zhang, Xin; El-Khoury, Patrick Z.; Hess, Wayne P.

    2017-06-05

    Propagating surface plasmons (PSPs) launched from a protruded silver spherical cap structure are investigated using photoemission electron microscopy (PEEM) and finite difference time domain (FDTD) calculations. Our combined experimental and theoretical findings reveal that PSP coupling efficiency is comparable to conventional etched-in plasmonic coupling structures. Additionally, plasmon propagation direction can be varied by a linear rotation of the driving laser polarization. A simple geometric model is proposed in which the plasmon direction selectivity is proportional to the projection of the linear laser polarization on the surface normal. An application for the spherical cap coupler as a gate device is proposed. Overall, our results indicate that protruded cap structures hold great promise as elements in emerging surface plasmon applications.

  8. Theory of electron-plasmon coupling in semiconductors

    Science.gov (United States)

    Caruso, Fabio; Giustino, Feliciano

    2016-09-01

    The ability to manipulate plasmons is driving new developments in electronics, optics, sensing, energy, and medicine. Despite the massive momentum of experimental research in this direction, a predictive quantum-mechanical framework for describing electron-plasmon interactions in real materials is still missing. Here, starting from a many-body Green's function approach, we develop an ab initio approach for investigating electron-plasmon coupling in solids. As a first demonstration of this methodology, we show that electron-plasmon scattering is the primary mechanism for the cooling of hot carriers in doped silicon, it is key to explaining measured electron mobilities at high doping, and it leads to a quantum zero-point renormalization of the band gap in agreement with experiment.

  9. Exploring plasmonic coupling in hole-cap arrays

    Directory of Open Access Journals (Sweden)

    Thomas M. Schmidt

    2015-01-01

    Full Text Available The plasmonic coupling between gold caps and holes in thin films was investigated experimentally and through finite-difference time-domain (FDTD calculations. Sparse colloidal lithography combined with a novel thermal treatment was used to control the vertical spacing between caps and hole arrays and compared to separated arrays of holes or caps. Optical spectroscopy and FDTD simulations reveal strong coupling between the gold caps and both Bloch Wave-surface plasmon polariton (BW-SPP modes and localized surface plasmon resonance (LSPR-type resonances in hole arrays when they are in close proximity. The interesting and complex coupling between caps and hole arrays reveals the details of the field distribution for these simple to fabricate structures.

  10. Strong plasmon coupling in self-assembled superparamagnetic nanoshell chains

    Science.gov (United States)

    Xiong, Min; Jin, Xiulong; Ye, Jian

    2016-02-01

    Construction of ordered patterns of plasmonic nanoparticles is greatly important for nanophotonics relevant applications. We have reported a facile and low-cost magnetic field induced self-assembly approach to construct plasmonic superparamagnetic nanoshell (SN) chains up to several hundred micrometers in a few seconds in a large area without templates or other assistance processes. Experimental and theoretical investigations of the near- and far-field optical properties indicate that the super- and sub-radiant modes of the SN chains continuously redshift with the increase of SN number and the Fano resonance emerges in the infinite double- and triple-line SN chains. Strong plasmon coupling effects in the SN chains result in great electric field enhancements at visible and infrared wavelengths, which indicates that these chain structures potentially can be used as a common substrate for both surface enhanced Raman scattering (SERS) and surface-enhanced infrared absorption (SEIRA) application. This fabrication method also offers a general strategy alternative to top-down processing that enables the construction of nanostructures for metamaterials, electromagnetic energy transport, and optical waveguide.Construction of ordered patterns of plasmonic nanoparticles is greatly important for nanophotonics relevant applications. We have reported a facile and low-cost magnetic field induced self-assembly approach to construct plasmonic superparamagnetic nanoshell (SN) chains up to several hundred micrometers in a few seconds in a large area without templates or other assistance processes. Experimental and theoretical investigations of the near- and far-field optical properties indicate that the super- and sub-radiant modes of the SN chains continuously redshift with the increase of SN number and the Fano resonance emerges in the infinite double- and triple-line SN chains. Strong plasmon coupling effects in the SN chains result in great electric field enhancements at visible

  11. Reversible Gating of Plasmonic Coupling for Optical Signal Amplification.

    Science.gov (United States)

    Khoury, Christopher G; Fales, Andrew M; Vo-Dinh, Tuan

    2016-07-20

    Amplification of optical signals is useful for a wide variety of applications, ranging from data signal transmission to chemical sensing and biomedical diagnostics. One such application in chemical sensing is surface-enhanced Raman scattering (SERS), an important technique for increasing the Raman signal using the plasmonic effect of enhanced electromagnetic fields associated with metallic nanostructures. One of the most important limitations of SERS-based amplification is the difficulty to reproducibly control the SERS signal. Here, we describe the design and implementation of a unique hybrid system capable of producing reversible gating of plasmonic coupling for Raman signal amplification. The hybrid system is composed of two subsystems: (1) colloidal magneto-plasmonic nanoparticles for SERS enhancement and (2) a micromagnet substrate with an externally applied magnetic field to modulate the colloidal nanoparticles. For this proof of concept demonstration, the nanoparticles were labeled with a Raman-active dye, and it was shown that the detected SERS signal could be reproducibly modulated by controlling the externally applied magnetic field. The developed system provides a simple, robust, inexpensive, and reusable device for SERS signal modulation. These properties will open up new possibilities for optical signal amplification and gating as well for high-throughput, reproducible SERS detection.

  12. Enhancement of the Modulation Bandwidth for surface Plasmon coupled LEDs for Visible Light Communication

    DEFF Research Database (Denmark)

    Li, Jiehui; Fadil, Ahmed; Ou, Haiyan

    2016-01-01

    The modulation bandwidth of surface plasmon coupled GaN-based LEDs is increased by ~1.2 times to 434.5 MHz compared with normal LED by applying Ag nanoparticles. These findings will help for the industrialization of VLC system.......The modulation bandwidth of surface plasmon coupled GaN-based LEDs is increased by ~1.2 times to 434.5 MHz compared with normal LED by applying Ag nanoparticles. These findings will help for the industrialization of VLC system....

  13. UV Nano-Lights - Nonlinear Quantum Dot-Plasmon Coupling

    Science.gov (United States)

    2016-06-20

    nanomaterials systems for nonlinear optics. PROJECT TIMELINE The project timeline was segmented into 3 monthly intervals. The PhD students, assisted by...technique to remove the scattering component of light from the fluorescence emission with commonly-used fluorometers [Shortell, Optics Express...nanostructure light interaction and also has helped understand and remove unwanted signal contamination through optical element interference effects as

  14. Metal-Semiconductor Nanoparticle Hybrids Formed by Self-Organization: A Platform to Address Exciton-Plasmon Coupling.

    Science.gov (United States)

    Strelow, Christian; Theuerholz, T Sverre; Schmidtke, Christian; Richter, Marten; Merkl, Jan-Philip; Kloust, Hauke; Ye, Ziliang; Weller, Horst; Heinz, Tony F; Knorr, Andreas; Lange, Holger

    2016-08-10

    Hybrid nanosystems composed of excitonic and plasmonic constituents can have different properties than the sum of of the two constituents, due to the exciton-plasmon interaction. Here, we report on a flexible model system based on colloidal nanoparticles that can form hybrid combinations by self-organization. The system allows us to tune the interparticle distance and to combine nanoparticles of different sizes and thus enables a systematic investigation of the exciton-plasmon coupling by a combination of optical spectroscopy and quantum-optical theory. We experimentally observe a strong influence of the energy difference between exciton and plasmon, as well as an interplay of nanoparticle size and distance on the coupling. We develop a full quantum theory for the luminescence dynamics and discuss the experimental results in terms of the Purcell effect. As the theory describes excitation as well as coherent and incoherent emission, we also consider possible quantum optical effects. We find a good agreement of the observed and the calculated luminescence dynamics induced by the Purcell effect. This also suggests that the self-organized hybrid system can be used as platform to address quantum optical effects.

  15. Modulation of surface plasmon coupling-in by one-dimensional surface corrugation

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Tejeira, F; Rodrigo, Sergio G; Martin-Moreno, L [Departamento de Fisica de la Materia Condensada, Facultad de Ciencas-ICMA, Universidad de Zaragoza-CSIC, E-50009 Zaragoza (Spain); Garcia-Vidal, F J [Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); Devaux, E; Dintinger, J; Ebbesen, T W [Laboratoire de Nanostructures, ISIS, Universite Louis Pasteur, F-67000 Strasbourg (France); Krenn, J R [Institute of Physics, Karl Franzens University, A-8010 Graz (Austria); Radko, I P; Bozhevolnyi, S I [Department of Physics and Nanotechnology, Aalborg University, DK-9220 Aalborg (Denmark); Gonzalez, M U; Weeber, J C; Dereux, A [Laboratoire de Physique de l' Universite de Bourgogne, UMR CNRS 5027, F-21078 Dijon (France)], E-mail: lmm@unizar.es

    2008-03-15

    Surface plasmon-polaritons have recently attracted renewed interest in the scientific community for their potential in sub-wavelength optics, light generation and non-destructive sensing. Given that they cannot be directly excited by freely propagating light due to their intrinsic binding to the metal surface, the light-plasmon coupling efficiency becomes of crucial importance for the success of any plasmonic device. Here, we present a comprehensive study on the modulation (enhancement or suppression) of such a coupling efficiency by means of one-dimensional surface corrugation. Our approach is based on simple wave interference and enables us to make quantitative predictions which have been experimentally confirmed at both the near-infrared and telecom ranges.

  16. Shifting molecular localization by plasmonic coupling in a single-molecule mirage

    Science.gov (United States)

    Raab, Mario; Vietz, Carolin; Stefani, Fernando Daniel; Acuna, Guillermo Pedro; Tinnefeld, Philip

    2017-01-01

    Over the last decade, two fields have dominated the attention of sub-diffraction photonics research: plasmonics and fluorescence nanoscopy. Nanoscopy based on single-molecule localization offers a practical way to explore plasmonic interactions with nanometre resolution. However, this seemingly straightforward technique may retrieve false positional information. Here, we make use of the DNA origami technique to both control a nanometric separation between emitters and a gold nanoparticle, and as a platform for super-resolution imaging based on single-molecule localization. This enables a quantitative comparison between the position retrieved from single-molecule localization, the true position of the emitter and full-field simulations. We demonstrate that plasmonic coupling leads to shifted molecular localizations of up to 30 nm: a single-molecule mirage.

  17. Solution deposition of nanometer scale silver films as an alternative to vapor deposition for plasmonic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Derek S.; Sathish, R. Sai; Kostov, Yordan [Center for Advanced Sensor Technology and Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Rao, Govind, E-mail: grao@umbc.ed [Center for Advanced Sensor Technology and Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

    2010-05-03

    We report the attainment of surface plasmon-coupled emission (SPCE) from highly uniform thin silver films, solution-deposited on glass substrates by a wet chemistry approach. The surface morphology of these films was characterized by atomic force microscopy. The SPCE emission enhancements, polarization and angularity obtained from solution-deposited silver on BK7 glass were comparable to that achieved from conventional SPCE slides prepared via vapor deposition. This facile, wet chemistry procedure for the deposition of SPCE films provides an inexpensive, low maintenance alternative to vapor deposition for SPCE substrate preparation. This would allow the fluorescence observation technique to become more readily available for high sensitivity, low cost applications.

  18. Application of SPCE061A in Smart Home System%SPCE061A在智能家居系统中的应用

    Institute of Scientific and Technical Information of China (English)

    高红亮; 刘金华

    2009-01-01

    SPCE061A为核心作为主控制器,以89C51及相关硬件电路为分控制器,利用电话接口和电力线载波通信,设计了一种智能家居系统,文中介绍了SPCE061A的芯片特性及其在主控制器模块中的应用,在软件设计部分,介绍了系统软件的设计结构,详细介绍了语音识别子程序的设计并给出了部分关键代码,相比传统的智能家居系统,该系统人机交互性好、可靠性好、性价比高,易于推广和应用.

  19. Two-color, laser excitation improves temporal resolution for detecting the dynamic, plasmonic coupling between metallic nanoparticles.

    Science.gov (United States)

    Wiener, Diane M; Lionberger, Troy A

    2013-05-21

    The ability of two, scattering gold nanoparticles (GNPs) to plasmonically couple in a manner that is dependent on the interparticle separation has been exploited to measure nanometer-level displacements. However, despite broad applicability to monitoring biophysical dynamics, the long time scales (dynamic molecular processes, generally occurring over several milliseconds. Here, we introduce a new technique intended to overcome this technical limitation: ratiometric analysis using monochromatic, evanescent darkfield illumination (RAMEDI). As a proof-of-principle, we monitored dynamic, plasmonic coupling arising from the binding of single biotin- and neutravidin-GNPs with a temporal resolution of 38 ms. We also show that the observable bandwidth is extendable to faster time scales by demonstrating that RAMEDI is capable of achieving a signal-to-noise ratio greater than 20 from individual GNPs observed with 200 Hz bandwidth.

  20. Tailoring alphabetical metamaterials in optical frequency: plasmonic coupling, dispersion, and sensing.

    Science.gov (United States)

    Zhang, Jun; Cao, Cuong; Xu, Xinlong; Liow, Chihao; Li, Shuzhou; Tan, Pingheng; Xiong, Qihua

    2014-04-22

    Tailoring optical properties of artificial metamaterials, whose optical properties go beyond the limitations of conventional and naturally occurring materials, is of importance in fundamental research and has led to many important applications such as security imaging, invisible cloak, negative refraction, ultrasensitive sensing, and transformable and switchable optics. Herein, by precisely controlling the size, symmetry, and topology of alphabetical metamaterials with U, S, Y, H, U-bar, and V shapes, we have obtained highly tunable optical response covering visible-to-infrared (vis-NIR) optical frequency. In addition, we show a detailed study on the physical origin of resonance modes, plasmonic coupling, the dispersion of resonance modes, and the possibility of negative refraction. We have found that all the electronic and magnetic modes follow the dispersion of surface plasmon polaritons; thus, essentially they are electronic- and magnetic-surface-plasmon-polaritons-like (ESPP-like and MSPP-like) modes resulted from diffraction coupling between localized surface plasmon and freely propagating light. On the basis of the fill factor and formula of magnetism permeability, we predict that the alphabetical metamaterials should show the negative refraction capability in visible optical frequency. Furthermore, we have demonstrated the specific ultrasensitive surface enhanced Raman spectroscopy (SERS) sensing of monolayer molecules and femtomolar food contaminants by tuning their resonance to match the laser wavelength, or by tuning the laser wavelength to match the plasmon resonance of metamaterials. Our tunable alphabetical metamaterials provide a generic platform to study the electromagnetic properties of metamaterials and explore the novel applications in optical frequency.

  1. Cascaded plasmon-plasmon coupling mediated energy transfer across stratified metal-dielectric nanostructures

    Science.gov (United States)

    Golmakaniyoon, Sepideh; Hernandez-Martinez, Pedro Ludwig; Demir, Hilmi Volkan; Sun, Xiao Wei

    2016-01-01

    Surface plasmon (SP) coupling has been successfully applied to nonradiative energy transfer via exciton-plasmon-exciton coupling in conventionally sandwiched donor-metal film-acceptor configurations. However, these structures lack the desired efficiency and suffer poor photoemission due to the high energy loss. Here, we show that the cascaded exciton-plasmon-plasmon-exciton coupling in stratified architecture enables an efficient energy transfer mechanism. The overlaps of the surface plasmon modes at the metal-dielectric and dielectric-metal interfaces allow for strong cross-coupling in comparison with the single metal film configuration. The proposed architecture has been demonstrated through the analytical modeling and numerical simulation of an oscillating dipole near the stratified nanostructure of metal-dielectric-metal-acceptor. Consistent with theoretical and numerical results, experimental measurements confirm at least 50% plasmon resonance energy transfer enhancement in the donor-metal-dielectric-metal-acceptor compared to the donor-metal-acceptor structure. Cascaded plasmon-plasmon coupling enables record high efficiency for exciton transfer through metallic structures. PMID:27698422

  2. Plasmon-coupled resonance energy transfer: A real-time electrodynamics approach.

    Science.gov (United States)

    Ding, Wendu; Hsu, Liang-Yan; Schatz, George C

    2017-02-14

    This paper presents a new real-time electrodynamics approach for determining the rate of resonance energy transfer (RET) between two molecules in the presence of plasmonic or other nanostructures (inhomogeneous absorbing and dispersive media). In this approach to plasmon-coupled resonance energy transfer (PC-RET), we develop a classical electrodynamics expression for the energy transfer matrix element which is evaluated using the finite-difference time-domain (FDTD) method to solve Maxwell's equations for the electric field generated by the molecular donor and evaluated at the position of the molecular acceptor. We demonstrate that this approach yields RET rates in homogeneous media that are in precise agreement with analytical theory based on quantum electrodynamics (QED). In the presence of gold nanoparticles, our theory shows that the long-range decay of the RET rates can be significantly modified by plasmon excitation, with rates increased by as much as a factor of 10(6) leading to energy transfer rates over hundreds of nm that are comparable to that over tens of nm in the absence of the nanoparticles. These promising results suggest important future applications of the PC-RET in areas involving light harvesting or sensing, where energy transfer processes involving inhomogeneous absorbing and dispersive media are commonplace.

  3. Plasmon Coupling Enhanced Raman Scattering Nanobeacon for Single-Step, Ultrasensitive Detection of Cholera Toxin.

    Science.gov (United States)

    Zhang, Chong-Hua; Liu, Ling-Wei; Liang, Ping; Tang, Li-Juan; Yu, Ru-Qin; Jiang, Jian-Hui

    2016-08-02

    We report the development of a novel plasmon coupling enhanced Raman scattering (PCERS) method, PCERS nanobeacon, for ultrasensitive, single-step, homogeneous detection of cholera toxin (CT). This method relies on our design of the plasmonic nanoparticles, which have a bilayer phospholipid coating with embedded Raman indicators and CT-binding ligands of monosialoganglioside (GM1). This design allows a facile synthesis of the plasmonic nanoparticle via two-step self-assembly without any specific modification or chemical immobilization. The realization of tethering GM1 on the surface imparts the plasmonic nanoparticles with high affinity, excellent specificity, and multivalence for interaction with CT. The unique lipid-based bilayer coated structure also affords excellent biocompatibility and stability for the plasmonic nanoparticles. The plasmonic nanoparticles are able to show substantial enhancement of the surface-enhanced Raman scattering (SERS) signals in a single-step interaction with CT, because of their assembly into aggregates in response to the CT-sandwiched interactions. The results reveal that the developed nanobeacon provides a simple but ultrasensitive sensor for rapid detection of CT with a large signal-to-background ratio and excellent reproducibility in a wide dynamic range, implying its potential for point-of-care applications in preventive and diagnostic monitoring of cholera.

  4. 基于SPCE061A和PTR8000的模拟SPI总线通信技术%Technology of Simulative SPI Communication Based on SPCE061A and PTR8000

    Institute of Scientific and Technical Information of China (English)

    关硕; 关济实

    2008-01-01

    在凌阳公司的SPCE061A单片机和讯通公司的PTR8000通讯模块组成的无线通讯系统中,由于PTR8000通讯模块只具备SPI通信接口,而SPCE061A单片机不具备SPI接口,为此采用了SPCE061A通用I/O口和软件模拟SPI通信方法,实现了二者之间的通信,从而充分发挥了SPCE061A和PTR8000各自的优势.此方法同样适用于解决其他非SPI接口单片杌系统与具备SPI接口外围器件的通讯问题.

  5. Water polarization induced by thermal gradients: the extended simple point charge model (SPC/E).

    Science.gov (United States)

    Armstrong, J A; Bresme, F

    2013-07-07

    We investigate the non-equilibrium response of extended simple point charge (SPC/E) water to thermal gradients. Using non-equilibrium molecular dynamics simulations, we show that SPC/E water features the thermo-polarization orientation effect, namely, water becomes polarized as a response to a thermal gradient. The polarization field increases linearly with the thermal gradient, in agreement with predictions of non-equilibrium thermodynamics theory. This observation confirms the generality of the thermo-polarization effect, first reported using the Modified Central Force Model (MCFM), and shows this physical effect is present irrespective of the water model details, in particular, dipole moment magnitude and model flexibility. The magnitude of the effect is the same for both models, although the sign of the electrostatic field is reversed in going from the MCFM to the SPC/E model. We further analyze the impact that the molecular geometry and mass distribution has on the magnitude of the polarization. Our results indicate that the thermo-polarization effect should be observed in a wide range of polar fluids, including fluids where hydrogen bonding is not present. Using various molecular models, we show that the polarization of these fluids under appropriate thermodynamic conditions can be of the same order or stronger than in water.

  6. Bonding and Anti-bonding Modes of Plasmon Coupling Effects in TiO2-Ag Core-shell Dimers

    OpenAIRE

    Quanshui Li; Zhili Zhang

    2016-01-01

    Bonding and anti-bonding modes of plasmon coupling effects are numerically investigated in TiO2-Ag core-shell nano dimers. First, splitting phenomena of the coupled anti-bonding modes are observed under the longitudinal polarization when the distance between the monomers decreases to a certain level. Second, one of the split resonance modes is identified to be formed by the dipole anti-bonding mode of the monomers from charge density distribution patterns. Those split modes have similar redsh...

  7. 基于SPCE061A的SPI通信的实现%Implementation of SPI Communication Based on SPCE061A

    Institute of Scientific and Technical Information of China (English)

    黄金明; 宋明慧

    2007-01-01

    SPI总线设备以其接口简单,传输可靠、高效的特点被广泛应用,但是部分单片机或嵌入式系统本身不具有SPI接口,这在一定程度上限制了SPI外部设备的应用.文章提出了一种利用I/O口模拟SPI总线时序进行串行通信的方法,并通过SPCE061A系统与SD卡模块的SPI通信的实现,验证了这种方法的可行性.

  8. Plasmonic coupling with most of the transition metals: a new family of broad band and near infrared nanoantennas

    Science.gov (United States)

    Manchon, Delphine; Lermé, Jean; Zhang, Taiping; Mosset, Alexis; Jamois, Cécile; Bonnet, Christophe; Rye, Jan-Michael; Belarouci, Ali; Broyer, Michel; Pellarin, Michel; Cottancin, Emmanuel

    2014-12-01

    In this article, we show for the first time, both theoretically and empirically, that plasmonic coupling can be used to generate Localized Surface Plasmon Resonances (LSPRs) in transition metal dimeric nano-antennas (NAs) over a broad spectral range (from the visible to the near infrared) and that the spectral position of the resonance can be controlled through morphological variation of the NAs (size, shape, interparticle distance). First, accurate calculations using the generalized Mie theory on spherical dimers demonstrate that we can take advantage of the plasmonic coupling to enhance LSPRs over a broad spectral range for many transition metals (Pt, Pd, Cr, Ni etc.). The LSPR remains broad for low interparticle distances and masks the various hybridized modes within the overall resonance. However, an analysis of the charge distribution on the surface of the nanoparticles reveals these modes and their respective contributions to the observed LSPR. In the case of spherical dimers, the transfer of the oscillator strengths from the ``dipolar'' mode to higher orders involves a maximum extinction cross-section for intermediate interparticle distances of a few nanometers. The emergence of the LSPR has been then experimentally illustrated with parallelepipedal NAs (monomers and dimers) made of various transition metals (Pt, Pd and Cr) and elaborated by nanolithography. Absolute extinction cross-sections have been measured with the spatial modulation spectroscopy technique over a broad spectral range (300-900 nm) for individual NAs, the morphology of which has been independently characterized by electron microscopy imaging. A clear enhancement of the LSPR has been revealed for a longitudinal excitation and plasmonic coupling has been clearly evidenced in dimers by an induced redshift and broadening of the LSPR compared to monomers. Furthermore, the LSPR has been shown to be highly sensitive to slight modifications of the interparticle distance. All the experimental

  9. Nanoscale Optical Emitters for High Density Information Processing using Photonic-Plasmonic Coupling in Coaxial Nanopillars

    Science.gov (United States)

    2015-03-10

    emission/absorption rates and structured light (i.e., phase engineered) manipulation on a Si chip . Imaging systems, miniaturized photodetector arrays and... chip . Imaging systems, miniaturized photodetector arrays and light sources with specified emission patterns can be developed based on the concepts...sputtering, top-down lithography and etching processes. By combining measurements of photoluminescence intensity and decay rate we measure a 25 times

  10. Competition Between Resonant Plasmonic Coupling and Electrostatic Interaction in Reduced Graphene Oxide Quantum Dots

    Science.gov (United States)

    Karna, Sanjay; Mahat, Meg; Choi, Tae-Youl; Shimada, Ryoko; Wang, Zhiming; Neogi, Arup

    2016-11-01

    The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect.

  11. Competition Between Resonant Plasmonic Coupling and Electrostatic Interaction in Reduced Graphene Oxide Quantum Dots.

    Science.gov (United States)

    Karna, Sanjay; Mahat, Meg; Choi, Tae-Youl; Shimada, Ryoko; Wang, Zhiming; Neogi, Arup

    2016-11-22

    The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect.

  12. Mid-infrared surface plasmon coupled emitters utilizing intersublevel transitions in InAs quantum dots.

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, Stephen A. (Princeton University, Princeton, NJ); Chow, Weng Wah; Passmore, Brandon Scott; Ribaudo, Troy (University of Massachusetts Lowell, Lowell, MA); Adams, David (University of Massachusetts Lowell, Lowell, MA); Wasserman, Daniel (University of Massachusetts Lowell, Lowell, MA); Shaner, Eric Arthur

    2010-08-01

    We demonstrate mid-infrared electroluminescence from intersublevel transitions in self-assembled InAs quantum dots coupled to surface plasmon modes on metal hole arrays. Subwavelength metal hole arrays with different periodicity are patterned into the top contact of the broadband (9-15 {micro}m) quantum dot material and the measured electroluminescence is compared to devices without a metal hole array. The resulting normally directed emission is narrowed and a splitting in the spectral structure is observed. By applying a coupled quantum electrodynamic model and using reasonable values for quantum dot distributions and plasmon linewidths we are able to reproduce the experimentally measured spectral characteristics of device emission when using strong coupling parameters.

  13. Bonding and Anti-bonding Modes of Plasmon Coupling Effects in TiO2-Ag Core-shell Dimers

    Science.gov (United States)

    Li, Quanshui; Zhang, Zhili

    2016-01-01

    Bonding and anti-bonding modes of plasmon coupling effects are numerically investigated in TiO2-Ag core-shell nano dimers. First, splitting phenomena of the coupled anti-bonding modes are observed under the longitudinal polarization when the distance between the monomers decreases to a certain level. Second, one of the split resonance modes is identified to be formed by the dipole anti-bonding mode of the monomers from charge density distribution patterns. Those split modes have similar redshift behaviors as the coupled dipole bonding modes in the same situations. Furthermore, the intensities of those anti-bonding modes weaken with decreasing distance between the monomers, because of the interaction of the induced dipole moment in the monomers and the charge distribution variation on the facing surfaces of the gap by the coulomb attraction. Other split bands are the higher-order mode (octupole-like or triakontadipole-like), which do not have obvious peak-shift behavior, and the intensities have very little attenuation with decreasing distance. Finally, the coupling of the bonding and anti-bonding modes under the longitudinal polarization is symmetric (bonding).

  14. Mechanical control of the plasmon coupling with Au nanoparticle arrays fixed on the elastomeric film via chemical bond

    Science.gov (United States)

    Bedogni, Elena; Kaneko, Satoshi; Fujii, Shintaro; Kiguchi, Manabu

    2017-03-01

    We have fabricated Au nanoparticle arrays on the flexible poly(dimethylsiloxane) (PDMS) film. The nanoparticles were bound to the film via a covalent bond by a ligand exchange reaction. Thanks to the strong chemical bonding, highly stable and uniformly dispersed Au nanoparticle arrays were fixed on the PDMS film. The Au nanoparticle arrays were characterized by the UV–vis, scanning electron microscope (SEM) and surface enhanced Raman scattering (SERS). The UV–vis and SEM measurements showed the uniformity of the surface-dispersed Au nanoparticles, and SERS measurement confirmed the chemistry of the PDMS film. Reflecting the high stability and the uniformity of the Au nanoparticle arrays, the plasmon wavelength of the Au nanoparticles reversely changed with modulation of the interparticle distance, which was induced by the stretching of the PDMS film. The plasmon wavelength linearly decreased from 664 to 591 nm by stretching of 60%. The plasmon wavelength shift can be explained by the change in the strength of the plasmon coupling which is mechanically controlled by the mechanical strain.

  15. Reverse Monte Carlo modeling of liquid water with the explicit use of the SPC/E interatomic potential

    Science.gov (United States)

    Pethes, Ildikó; Pusztai, László

    2017-02-01

    Reverse Monte Carlo (RMC) modeling of liquid water, based on one neutron and one X-ray diffraction data set, applying also the most popular interatomic potential for water, extended simple point charge (SPC/E), has been performed. The strictly rigid geometry of SPC/E water molecules had to be loosened somewhat, in order to be able to produce a good fit to both sets of experimental data. In the final particle configurations, regularly shaped water molecules and straight hydrogen bonding angles were found to be consistent with diffraction results. It has been demonstrated that the explicit use of interatomic potentials in RMC has a role to play in future structural modeling of water and aqueous solutions.

  16. Homogeneous SPC/E water nucleation in large molecular dynamics simulations

    CERN Document Server

    Angelil, R; Tanaka, K; Tanaka, H

    2015-01-01

    We perform direct large molecular dynamics simulations of homogeneous SPC/E water nucleation, using up to $\\sim 4\\cdot 10^6$ molecules. Our large system sizes allow us to measure extremely low and accurate nucleation rates, down to $\\sim 10^{19}\\,\\textrm{cm}^{-3}\\textrm{s}^{-1}$, helping close the gap between experimentally measured rates $\\sim 10^{17}\\,\\textrm{cm}^{-3}\\textrm{s}^{-1}$. We are also able to precisely measure size distributions, sticking efficiencies, cluster temperatures, and cluster internal densities. We introduce a new functional form to implement the Yasuoka-Matsumoto nucleation rate measurement technique (threshold method). Comparison to nucleation models shows that classical nucleation theory over-estimates nucleation rates by a few orders of magnitude. The semi-phenomenological nucleation model does better, under-predicting rates by at worst, a factor of 24. Unlike what has been observed in Lennard-Jones simulations, post-critical clusters have temperatures consistent with the run avera...

  17. Homogeneous SPC/E water nucleation in large molecular dynamics simulations.

    Science.gov (United States)

    Angélil, Raymond; Diemand, Jürg; Tanaka, Kyoko K; Tanaka, Hidekazu

    2015-08-14

    We perform direct large molecular dynamics simulations of homogeneous SPC/E water nucleation, using up to ∼ 4 ⋅ 10(6) molecules. Our large system sizes allow us to measure extremely low and accurate nucleation rates, down to ∼ 10(19) cm(-3) s(-1), helping close the gap between experimentally measured rates ∼ 10(17) cm(-3) s(-1). We are also able to precisely measure size distributions, sticking efficiencies, cluster temperatures, and cluster internal densities. We introduce a new functional form to implement the Yasuoka-Matsumoto nucleation rate measurement technique (threshold method). Comparison to nucleation models shows that classical nucleation theory over-estimates nucleation rates by a few orders of magnitude. The semi-phenomenological nucleation model does better, under-predicting rates by at worst a factor of 24. Unlike what has been observed in Lennard-Jones simulations, post-critical clusters have temperatures consistent with the run average temperature. Also, we observe that post-critical clusters have densities very slightly higher, ∼ 5%, than bulk liquid. We re-calibrate a Hale-type J vs. S scaling relation using both experimental and simulation data, finding remarkable consistency in over 30 orders of magnitude in the nucleation rate range and 180 K in the temperature range.

  18. 基于SPCE061A板语音识别公交车报站器的设计%The design of speech recognition bus stations device based on SPCE061A

    Institute of Scientific and Technical Information of China (English)

    王炳堃

    2011-01-01

    从司机角度出发,以凌阳公司SPCE061A板为硬件基础,用unSPTM软件进行编程,通过相关软件对语音资源进行录制、格式转化、压缩和管理,构成了增加语音输入识别方式的公交车报站器.报站器具有按键控制和语音控制两种方式,构成更具人性化特点.%This paper focuses in the view of drivers,based on the Sunplus SPCE061A SCM of the company as hardware and unSPTM as software to preparation for the process,and does voice recording,format conversion,compression and management through the relevant software resources to increase the voice input means of identification the stops the bus-stop device.In short,the two ways' combination approach allow drivers to have completed stations selectivity,and made the Bus Station device more human characteristics.

  19. ‘Squeezed’ interparticle properties for plasmonic coupling and SERS characteristics of duplex DNA conjugated/linked gold nanoparticles of homo/hetero-sizes

    Science.gov (United States)

    Skeete, Zakiya; Cheng, Han-Wen; Ngo, Quang Minh; Salazar, Christian; Sun, Winny; Luo, Jin; Zhong, Chuan-Jian

    2016-08-01

    The formation of interparticle duplex DNA conjugates with gold nanoparticles constitutes the basis for interparticle plasmonic coupling responsible for surface-enhanced Raman scattering signal amplification, but understanding of its correlation with interparticle spatial properties and particle sizes, especially in aqueous solutions, remains elusive. This report describes findings of an investigation of interparticle plasmonic coupling based on experimental measurements of localized surface plasmon resonance and surface enhanced Raman scattering characteristics for gold nanoparticles in aqueous solutions upon introduction of interparticle duplex DNA conjugates to define the interparticle spatial properties. Theoretical simulations of the interparticle optical properties and electric field enhancement based on a dimer model have also been performed to aid the understanding of the experimental results. The results have revealed a ‘squeezed’ interparticle spatial characteristic in which the duplex DNA-defined distance is close or shorter than A-form DNA conformation, which are discussed in terms of the interparticle interactions, providing fresh insight into the interparticle double-stranded DNA-defined interparticle spatial properties for the design of highly-sensitive nanoprobes in solutions for biomolecular detection.

  20. DETERMINATION OF UREA IN BLOOD SERUM BY CONDUCTOMETRIC BIOSENSOR Screen Printed Carbon Electrode (SPCE – NATA DE COCO

    Directory of Open Access Journals (Sweden)

    Sendy Kurniawan

    2011-11-01

    Full Text Available Urea is byproduct of protein degradation in normal serum about 10.7 – 42.8 mg/dL. Conductometric biosensor for determination urea in blood serum based on hydrolysis reaction of urea by urease produce ammonia (NH3 and carbon dioxide (CO2 which will be ionized in water. The research, optimum condition of urease mass, nata de coco membrane thickness, and pH urea solution were studied for determination performance of biosensor while the biosensor was applied for blood serum sample. The biosensor was made from Screen Printed Carbon Electrode (SPCE which coated nata de coco immobilized urease. Accordingly, various pH (6; 7; 8; 9, urease mass (0.1; 0.5; 1,0; 1.5 µg, and membran thickness (5; 10; 15 µm was studied in detail with range concentrations of urea solution were 0 to 5 ppm in phophate buffer 0.01 M pH 8 and SPCE area 5 mm2. The result showed that the optimum performance in 1 µg urease mass, 5 µm membrane thickness, and pH solution was 8, whereas the sensitivity was 14.8 µS/ppm, detection limit was 0.035 ppm, and range concentrations of urea were 0.035 to 0.400 ppm. The biosensor have 73 to 87 % accuration.when be applied in blood serum sample.

  1. Model Channel Ion Currents in NaCl - SPC/E Solution with Applied-Field Molecular Dynamics

    CERN Document Server

    Crozier, P S; Rowley, R L; Busath, D D; Crozier, Paul S.; Henderson, Douglas; Rowley, Richard L.; Busath, David D.

    2001-01-01

    Using periodic boundary conditions and a constant applied field, we have simulated current flow through an 8.125 Angstrom internal diameter, rigid, atomistic channel with polar walls in a rigid membrane using explicit ions and SPC/E water. Channel and bath currents were computed from ten 10-ns trajectories for each of 10 different conditions of concentration and applied voltage. An electric field was applied uniformly throughout the system to all mobile atoms. On average, the resultant net electric field falls primarily across the membrane channel, as expected for two conductive baths separated by a membrane capacitance. The channel is rarely occupied by more than one ion. Current-voltage relations are concentration-dependent and superlinear at high concentrations.

  2. Dielectric properties of SPC/E and TIP4P under the static electric field and microwave field

    Science.gov (United States)

    Li, Di; Jia, Guo-zhu

    2016-05-01

    Nonequilibrium molecular dynamics simulations of the SPC/E and TIP4P models have been performed both in the absence and presence of the static electric field (0-3×109 V/m) and the microwave field (2.45 G, 0-3×109 V/m). The radial distribution function, dielectric constant, polarizability, dielectric relaxation time, hydrogen bonding and diffusion coefficient were investigated. Significant alteration in the static electric field has effect on the tetrahedral structure of water; the interaction between microwave and water depends on the hydrogen bonding. The 3×107 V/m is threshold intensity, as the intensity of the static electric field increases the decline of the dielectric constant becomes more pronounced, and the polarizability obviously increased with the increase of microwave field. And the life of hydrogen bonding is oscillatory under the high static electric field strength.

  3. Sensitive Glycoprotein Sandwich Assays by the Synergistic Effect of In Situ Generation of Raman Probes and Plasmonic Coupling of Ag Core-Au Satellite Nanostructures.

    Science.gov (United States)

    Bi, Xiaoshuang; Li, Xueyuan; Chen, Dong; Du, Xuezhong

    2016-05-01

    Sensitive surface-enhanced Raman scattering (SERS) assays of glycoproteins have been proposed using p-aminothiophenol (PATP)-embedded Ag core-Au satellite nanostructures modified with p-mercaptophenylboronic acid (PMBA) and the self-assembled monolayer of PMBA on a smooth gold-coated wafer. The apparent Raman probe PATP on the surfaces of the Ag cores underwent a photodimerization to generate 4,4'-dimercaptoazobenzene (DMAB) in situ upon excitation of laser, and the in situ generated DMAB acted as the actual Raman probe with considerably strong SERS signals, which was further enhanced by the plasmonic coupling of the Ag core-Au satellite nanostructures due to the synergistic effect. The sandwich assays of glycoproteins showed high sensitivity and excellent selectivity against nonglycoproteins. The Ag core-Au satellite SERS nanostructures can be used for highly sensitive SERS assays of other analytes.

  4. Effects of plasmonic coupling and electrical current on persistent photoconductivity of single-layer graphene on pristine and silver-nanoparticle-coated SiO2/Si.

    Science.gov (United States)

    Liu, Chih-Yi; Liang, Kengchih; Chang, Chun-Cheng; Tzeng, Yonhua

    2012-09-24

    Effects and mechanisms of conductivity variation of chemically vapor deposited single-layer graphene covering silver nanoparticles on SiO(2)/Si are reported based on blue-light (405 nm) induced plasmonic coupling and electrical current induced annealing and desorption of surface adsorbates. With 1V applied voltage, photoconductivity is positive except a brief negative period when the graphene is first illuminated by light. At 10 mV applied voltage, negative photoconductivity persists for hours. In comparison, negative photoconductivity of graphene on pristine SiO(2)/Si persists for tens of hours. When the applied voltage is increased to 1V, it takes tens of hours of light illumination to change to positive photoconductivity.

  5. Intelligent Wheelchair Control System Hardware Design Based on SPCE061A%基于SPCE061A的智能轮椅控制系统硬件设计

    Institute of Scientific and Technical Information of China (English)

    郝敏钗

    2012-01-01

    With the population aging problem is getting worse and people's living standards improve,whether it is Senile,congenital or acquired physically disabled persons on the demand for wheelchairs and other assisted walking tools will become increasingly urgent.In the EEG equipment to send and receive control side by adding a speech recognition system based on SPCE061 technology, when the brain is operating intent is issued,the signal triggered treated voice broadcast system,while the voice controlled device installed on the receiving end through the speech recognition,send the right drive and voice broadcast, and to control the motor system of the wheelchair, if drivers perceive information from the auditory error,timely adjustment of the brain consciousness,EEG recognition and speech recognition in order to achieve the double insurance smart wheelchair provide a new control method for disabled persons with physical disabilities.%随着人口老龄化问题越来越严重以及人民生活水平的提高,无论是高龄老年人还是先天或后天肢残者对轮椅等辅助步行工具的需求将日益迫切。在脑电设备的发送和接收控制端加入了基于SPCE061技术的语音识别系统,当大脑发出操作意图时,该信号经过处理触发语音播报系统,而受控设备上安装的语音接收端经过语音辨识,发出正确的驱动信息并进行语音播报,从而控制轮椅的电机系统,如果驾驶者从听觉上感知到信息错误,可及时调整大脑意识,从而实现脑电识别和语音-/y,~0对智能轮椅的双保险控制,为有肢体障碍的残疾人提供一种新的控制方式。

  6. Enhanced visible fluorescence in highly transparent Al-doped ZnO film by surface plasmon coupling of Ag nanoparticles

    Science.gov (United States)

    Bishnoi, Swati; Das, Rupali; Phadke, Parikshit; Kotnala, R. K.; Chawla, Santa

    2014-10-01

    ZnO:Al (AZO) film has been deposited on quartz substrate by Pulsed laser deposition and showed monophasic hexagonal structure of c-axis oriented nanorods upto 80 nm in height. AZO film was optimally conjugated with Ag nanoparticles (Ag NPs) in a hybrid nanostructure to achieve significant enhancement in the visible fluorescence emission. Augmented near field and extinction spectra of shape tailored Ag NPs and their dimers are simulated through FDTD method, and a direct association with fluorescence enhancement is established. Such plasmon- enhanced visible emission from a transparent conducting oxide could be very important for solar cell applications.

  7. Studies of Hot Photoluminescence in Plasmonically Coupled Silicon via Variable Energy Excitation and Temperature-Dependent Spectroscopy

    Science.gov (United States)

    2015-01-01

    By integrating silicon nanowires (∼150 nm diameter, 20 μm length) with an Ω-shaped plasmonic nanocavity, we are able to generate broadband visible luminescence, which is induced by high order hybrid nanocavity-surface plasmon modes. The nature of this super bandgap emission is explored via photoluminescence spectroscopy studies performed with variable laser excitation energies (1.959 to 2.708 eV) and finite difference time domain simulations. Furthermore, temperature-dependent photoluminescence spectroscopy shows that the observed emission corresponds to radiative recombination of unthermalized (hot) carriers as opposed to a resonant Raman process. PMID:25120156

  8. [SPC/E and TIP4P models for investigation of the conformational mobility of the insulin superfamily peptides].

    Science.gov (United States)

    Ksenofontova, O I

    2014-01-01

    In this work we carried out a comparative analysis of the two most popular water models-SPC/E and TIP4P and estimated the ability of using ones for insulin superfamily peptides-proinsulin and insulin-like growth factors (IGF1 and IGF2). It was shown that root-mean-square deviations and radius of gyration had tend to be in reversed phase when both water models were used. Only IGF1 had a plateau after 9000 ps. In addition, it was shown that in spite of the general nature of insulin-like packing maintenance, there were some differences in the secondary structures, when we used TIP4P and SPC/E. These differences could influence on the overall molecule dynamics and the ability to accept necessary conformation for interaction with cognate receptors. On the basis of the received data we concluded that it is necessary to use several, not one, water models for the study of the peptides conformational mobility.

  9. Molecular Simulations of the Vapor-Liquid Phase Interfaces of Pure Water Modeled with the SPC/E and the TIP4P/2005 Molecular Models

    Science.gov (United States)

    Vinš, Václav; Celný, David; Planková, Barbora; Němec, Tomáš; Duška, Michal; Hrubý, Jan

    2016-03-01

    In our previous study [Planková et al., EPJWeb. Conf. 92, 02071 (2015)], several molecular simulations of vapor-liquid phase interfaces for pure water were performed using the DL_POLY Classic software. The TIP4P/2005 molecular model was successfully used for the modeling of the density profile and the thickness of phase interfaces together with the temperature dependence of the surface tension. In the current study, the extended simple point charge (SPC/E) model for water was employed for the investigation of vapor-liquid phase interfaces over a wide temperature range from 250 K to 600 K. The TIP4P/2005 model was also used with the temperature step of 25 K to obtain more consistent data compared to our previous study. Results of the new simulations are in a good agreement with most of the literature data. TIP4P/2005 provides better results for the saturated liquid density with its maximum close to 275 K, while SPC/E predicts slightly better saturated vapor density. Both models give qualitatively correct representation for the surface tension of water. The maximum absolute deviation from the IAPWS standard for the surface tension of ordinary water is 10.4 mN · m-1 and 4.1 mN · m-1 over the temperature range from 275 K to 600 K in case of SPC/E and TIP4P/2005, respectively.

  10. The resonant, near-resonant, and off-resonant plasmon coupling effects for the bonding modes in two types of asymmetric dimer

    Science.gov (United States)

    Li, Quanshui; Hu, Jianling; Wang, Ziya; Wang, Fengping; Bao, Yongjun

    2014-07-01

    The resonant, near-resonant, and off-resonant plasmon coupling effects for the bonding modes in asymmetric dimers are illustrated by two types of configuration, one formed by a gold nanoparticle and a TiO2-Ag core-shell nanoparticle and the other formed by two TiO2-Ag core-shell nanoparticles with suitable sizes. The redshift and blueshift behaviours of the coupled bonding modes with decreasing gap are found under longitudinal and transverse polarization of light for these dimers in the resonant situation, respectively. Under the near-resonant situation, the redshift behaviours of the coupled bonding modes still remain under longitudinal polarization, whereas the two separated modes of monomers after coupling under transverse polarization exhibit no obvious peak-shift behaviours, and the one on the lower frequency side shows an apparent attenuation in the strength. Under the off-resonant situation, the redshift behaviours not only occur in the coupled modes under longitudinal polarization, but also occur in two separated modes under transverse polarization.

  11. Influence of plasmon coupling on the photoluminescence of ZnS/Ag nanoparticles obtained by laser irradiation in liquid

    Science.gov (United States)

    Moos, Rafaela; Graff, Ismael L.; de Oliveira, Vinicius S.; Schreiner, Wido H.; Bezerra, Arandi G.

    2017-10-01

    We investigate the photoluminescence, optical absorption and structural properties of ZnS submitted to laser irradiation in water and isopropyl alcohol. Nanoparticles were produced by irradiating micro-sized ZnS particles dispersed in both liquids, with and without the addition of Ag nanoparticles, taking advantage of the laser-assisted fragmentation effect. When ZnS microparticles are irradiated either in pure water or isopropyl alcohol a considerable size reduction is achieved (from micra to few nanometers). The photoluminescence of these nanoparticles mainly occurs in the UV, centered at 350 nm, and with smaller intensity in the visible, centered at 600 nm. Irradiation of ZnS microparticles dispersed in colloidal silver triggers a reaction between both materials, modifying its optical absorption and photoluminescent properties. After irradiation of ZnS in alcohol containing Ag nanoparticles, a giant increase of the UV photoluminescence is observed. Interestingly, when the irradiation is performed in aqueous Ag nanoparticles colloids, the photoluminescence suffers a red-shift towards the violet-blue. The data show that core-shell (Ag-ZnO) nanostructures are formed after irradiation and the visible emission likely originates from the ZnO shell grown around silver nanoparticles. The presence of Ag nanoparticles in the liquid medium promotes a stronger absorption of the laser beam during irradiation due to the coupling with the surface plasmon resonance, fostering intense reactions among ZnS, Ag nanoparticles, and the liquid medium. Our study shows that with a simple change of the liquid medium wherein the irradiation is conducted the photoluminescence can be tuned from UV to visible and core-shell nanostructures can be obtained.

  12. Design of label-free, homogeneous biosensing platform based on plasmonic coupling and surface-enhanced Raman scattering using unmodified gold nanoparticles.

    Science.gov (United States)

    Yi, Zi; Li, Xiao-Yan; Liu, Feng-Juan; Jin, Pei-Yan; Chu, Xia; Yu, Ru-Qin

    2013-05-15

    Surface-enhanced Raman scattering (SERS) has emerged as a promising spectroscopic technique for biosensing. However, to design a SERS-based biosensor, almost all currently used methods involve the time-consuming and complicated modification of the metallic nanoparticles with the Raman active dye and biorecognition element, which restricts their widespread applications. Herein, we report a label-free, homogeneous and easy-to-operate biosensing platform for the rapid, simple and sensitive SERS detection by using the unmodified gold nanoparticles (Au NPs). This strategy utilizes the difference in adsorption property of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) on citrate-coated Au NPs. In the presence of dsDNA, the aggregation of Au NPs takes place after adding salt solution because the dsDNA cannot adsorb on the Au NPs to protect them from salt-induced aggregation. Such aggregation gives rise to the plasmonic coupling of adjacent metallic NPs and turns on the enhancement of the Raman scattering, displaying a strong SERS signal. In contrast, the ssDNA can adsorb on the Au NPs surface through strong electrostatic attraction and protect them from salt-induced aggregation, showing a weak SERS signal. This approach is not only straightforward and simple in design but also rapid and convenient in operation. The feasibility and universality of the design have been demonstrated successfully by the detection of DNA and Hg(2+), and the assay possesses the superior signal-to-background ratio as high as ∼30 and excellent selectivity. The method can be extended to detect various analytes, such as other metal ions, proteins and small molecules by using the oligonucleotides that can selectively bind the analytes. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. On the accurate calculation of the dielectric constant from molecular dynamics simulations: The case of SPC/E and SWM4-DP water

    Science.gov (United States)

    Gereben, Orsolya; Pusztai, László

    2011-04-01

    The effect of the applied trajectory length on the convergence of the static dielectric constant was examined for the SPC/E water model with different system sizes. Very long simulation times of 6-8 ns were employed in order to track the convergence of this property. Temperature dependence and isotope effects were also investigated. A simulation for the polarizable SWM4-DP model was also carried out to compare the effect of different potential models. It is clearly shown that trajectories shorter than about 6 ns are not sufficient for a sufficiently accurate determination of the dielectric constant of these water models.

  14. Copper Determination in Gunshot Residue by Cyclic Voltammetric and Inductive Coupled Plasma-Optical Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Mohd Hashim Nurul’Afiqah Hashimah

    2016-01-01

    Full Text Available Analysis of gunshot residue (GSR is a crucial evidences for a forensic analyst in the fastest way. GSR analysis insists a suitable method provides a relatively simple, rapid and precise information on the spot at the crime scene. Therefore, the analysis of Cu(II in GSR using cyclic voltammetry (CV on screen printed carbon electrode (SPCE is a better choice compared to previous alternative methods such as Inductive Coupled Plasma-Optical Emission Spectroscopy (ICP-OES those required a long time for analysis. SPCE is specially designed to handle with microvolumes of sample such as GSR sample. It gives advantages for identification of copper in GSR on-site preliminary test to prevent the sample loss on the process to be analyzed in the laboratory. SPCE was swabbed directly on the shooter’s arm immediately after firing and acetate buffer was dropped on SPCE before CV analysis. For ICP-OES analysis, cotton that had been soaked in 0.5 M nitric acid was swabbed on the shooter’s arm immediately after firing and kept in a tightly closed sampling tube. Gold coated SPCE that had been through nanoparticles modification exhibits excellent performance on voltammograms. The calibration was linear from 1 to 50 ppm of copper, the limit of detection for copper was 0.3 ppm and a relative standard deviation was 6.1 %. The method was successfully applied to the determination of copper in GSR. The Cu determination on SPCE was compared and validated by ICP-OES method with 94 % accuracy.

  15. Temperature dependence of the microscopic structure and density anomaly of the SPC/E and TIP4P-Ew water models. Molecular dynamics simulation results

    Directory of Open Access Journals (Sweden)

    E. Galicia-Andrés

    2015-03-01

    Full Text Available We have investigated temperature trends of the microscopic structure of the SPC/E and TIP4P-Ew water models in terms of the pair distribution functions, coordination numbers, the average number of hydrogen bonds, the distribution of bonding states of a single molecule as well as the angular distribution of molecules by using the constant pressure molecular dynamics simulations. The evolution of the structure is put in correspondence with the dependence of water density on high temperatures down to the region of temperatures where the system becomes supercooled. It is shown that the fraction of molecules with three and four bonds determine the maximum density for both models. Moreover, the temperature dependence of the dielectric constant is obtained and analyzed.

  16. Optimized unlike-pair interactions for water-carbon dioxide mixtures described by the SPC/E and EPM2 models.

    Science.gov (United States)

    Vlcek, Lukas; Chialvo, Ariel A; Cole, David R

    2011-07-14

    The unlike-pair interaction parameters for the SPC/E-EPM2 models have been optimized to reproduce the mutual solubility of water and carbon dioxide at the conditions of liquid-supercritical fluid phase equilibria. An efficient global optimization of the parameters is achieved through an implementation of the coupling parameter approach, adapted to phase equilibria calculations in the Gibbs ensemble, that explicitly corrects for the overpolarization of the SPC/E water molecule in the nonpolar CO(2) environments. The resulting H(2)O-CO(2) force field accurately reproduces the available experimental solubilities at the two fluid phases in equilibria as well as the corresponding species tracer diffusion coefficients. © 2011 American Chemical Society

  17. Nonequilibrium molecular dynamics simulations of the thermal conductivity of water: a systematic investigation of the SPC/E and TIP4P/2005 models.

    Science.gov (United States)

    Römer, Frank; Lervik, Anders; Bresme, Fernando

    2012-08-21

    We report an extensive nonequilibrium molecular dynamics investigation of the thermal conductivity of water using two of the most accurate rigid nonpolarizable empirical models available, SPC/E and TIP4P/2005. Our study covers liquid and supercritical states. Both models predict the anomalous increase of the thermal conductivity with temperature and the thermal conductivity maximum, hence confirming their ability to reproduce the complex anomalous behaviour of water. The performance of the models strongly depends on the thermodynamic state investigated, and best agreement with experiment is obtained for states close to the liquid coexistence line and at high densities and temperatures. Considering the simplicity of these two models the overall agreement with experiments is remarkable. Our results show that explicit polarizability and molecular flexibility are not needed to reproduce the anomalous heat conduction of water.

  18. Ultrasensitive detection in optically dense physiological media: applications to fast reliable biological assays

    Science.gov (United States)

    Matveeva, Evgenia G.; Gryczynski, Ignacy; Berndt, Klaus W.; Lakowicz, Joseph R.; Goldys, Ewa; Gryczynski, Zygmunt

    2006-02-01

    We present a novel approach for performing fluorescence immunoassay in serum and whole blood using fluorescently labeled anti-rabbit IgG. This approach, which is based on Surface Plasmon-Coupled Emission (SPCE), provides increased sensitivity and substantial background reduction due to exclusive selection of the signal from the fluorophores located near a bio-affinity surface. Effective coupling range for SPCE is only couple of hundred nanometers from the metallic surface. Excited fluorophores outside the coupling layer do not contribute to SPCE, and their free-space emission is not transmitted through the opaque metallic film into the glass substrate. An antigen (rabbit IgG) was adsorbed to a slide covered with a thin silver metal layer, and the SPCE signal from the fluorophore-labeled anti-rabbit antibody, binding to the immobilized antigen, was detected. The effect of the sample matrix (buffer, human serum, or human whole blood) on the end-point immunoassay SPCE signal is discussed. The kinetics of binding could be monitored directly in whole blood or serum. The results showed that human serum and human whole blood attenuate the SPCE end-point signal and the immunoassay kinetic signal only approximately 2- and 3-fold, respectively (compared to buffer), resulting in signals that are easily detectable even in whole blood. The high optical absorption of the hemoglobin can be tolerated because only fluorophores within a couple of hundred nanometers from the metallic film contribute to SPCE. Both glass and plastic slides can be used for SPCE-based assays. We believe that SPCE has the potential of becoming a powerful approach for performing immunoassays based on surface-bound analytes or antibodies for many biomarkers directly in dense samples such as whole blood, without any need for washing steps.

  19. Development of a Nafion/MWCNT-SPCE-Based Portable Sensor for the Voltammetric Analysis of the Anti-Tuberculosis Drug Ethambutol

    Directory of Open Access Journals (Sweden)

    Rosa A. S. Couto

    2016-06-01

    Full Text Available Herein we describe the development, characterization and application of an electrochemical sensor based on the use of Nafion/MWCNT-modified screen-printed carbon electrodes (SPCEs for the voltammetric detection of the anti-tuberculosis (anti-TB drug ethambutol (ETB. The electrochemical behaviour of the drug at the surface of the developed Nafion/MWCNT-SPCEs was studied through cyclic voltammetry (CV and square wave voltammetry (SWV techniques. Electrochemical impedance spectroscopy (EIS and scanning electron microscopy (SEM were employed to characterize the modified surface of the electrodes. Results showed that, compared to both unmodified and MWCNTs-modified SPCEs, negatively charged Nafion/MWCNT-SPCEs remarkably enhanced the electrochemical sensitivity and selectivity for ETB due to the synergistic effect of the electrostatic interaction between cationic ETB molecules and negatively charged Nafion polymer and the inherent electrocatalytic properties of both MWCNTs and Nafion. Nafion/MWCNT-SPCEs provided excellent biocompatibility, good electrical conductivity, low electrochemical interferences and a high signal-to-noise ratio, providing excellent performance towards ETB quantification in microvolumes of human urine and human blood serum samples. The outcomes of this paper confirm that the Nafion/MWCNT-SPCE-based device could be a potential candidate for the development of a low-cost, yet reliable and efficient electrochemical portable sensor for the low-level detection of this antimycobacterial drug in biological samples.

  20. THE DEVELOPMENT OF CONDUCTOMETRIC BIOSENSOR FOR DETERMINATION OF URIC ACID CONCENTRATION IN HUMAN SERUM USING SCREEN PRINTED CARBON ELECTRODE (SPCE – NATA DE COCO

    Directory of Open Access Journals (Sweden)

    Abdi Naufal Ramadhan

    2015-09-01

    Full Text Available The control of uric acid is important. A high level of uric acid can cause gout disease. Therefore a simple, fast, and accurate method for uric acid determination is required. In this research a conductometric biosensor has been developed by SPCE – Nata de coco for uric acid determination. The prepared biosensor was optimized to get a good performance of biosensor and it is applicable for human serum samples. The optimized variables were enzyme concentration, membrane thickness and pH solution. The various enzyme concentration were 6 μg/mL; 12 μg/mL; 18μg/mL; 24 μg/mL. The various membrane thickness were 5 μm; 10 μm; 15 μm. Meanwhile, the various pH solution were 7; 7.5; 8; 8.5; 9. The optimum enzime concentration was 18 µg/mL with the membrane thickness and pH were 5 µm and 8, respectively. The prepared biosensor can determine the uric acid concentration at range of 0 – 1.2 ppm with the sensitivity of 7.74 µS/ppm and the limit detection is 0 ppm. The biosensor was applied to uric acid detection in human serum with accuracy of 95 %.

  1. Transport and dielectric properties of water and the influence of coarse-graining: Comparing BMW, SPC/E, and TIP3P models

    Science.gov (United States)

    Braun, Daniel; Boresch, Stefan; Steinhauser, Othmar

    2014-02-01

    Long-term molecular dynamics simulations are used to compare the single particle dipole reorientation time, the diffusion constant, the viscosity, and the frequency-dependent dielectric constant of the coarse-grained big multipole water (BMW) model to two common atomistic three-point water models, SPC/E and TIP3P. In particular, the agreement between the calculated viscosity of BMW and the experimental viscosity of water is satisfactory. We also discuss contradictory values for the static dielectric properties reported in the literature. Employing molecular hydrodynamics, we show that the viscosity can be computed from single particle dynamics, circumventing the slow convergence of the standard approaches. Furthermore, our data indicate that the Kivelson relation connecting single particle and collective reorientation time holds true for all systems investigated. Since simulations with coarse-grained force fields often employ extremely large time steps, we also investigate the influence of time step on dynamical properties. We observe a systematic acceleration of system dynamics when increasing the time step. Carefully monitoring energy/temperature conservation is found to be a sufficient criterion for the reliable calculation of dynamical properties. By contrast, recommended criteria based on the ratio of fluctuations of total vs. kinetic energy are not sensitive enough.

  2. Transport and dielectric properties of water and the influence of coarse-graining: comparing BMW, SPC/E, and TIP3P models.

    Science.gov (United States)

    Braun, Daniel; Boresch, Stefan; Steinhauser, Othmar

    2014-02-14

    Long-term molecular dynamics simulations are used to compare the single particle dipole reorientation time, the diffusion constant, the viscosity, and the frequency-dependent dielectric constant of the coarse-grained big multipole water (BMW) model to two common atomistic three-point water models, SPC/E and TIP3P. In particular, the agreement between the calculated viscosity of BMW and the experimental viscosity of water is satisfactory. We also discuss contradictory values for the static dielectric properties reported in the literature. Employing molecular hydrodynamics, we show that the viscosity can be computed from single particle dynamics, circumventing the slow convergence of the standard approaches. Furthermore, our data indicate that the Kivelson relation connecting single particle and collective reorientation time holds true for all systems investigated. Since simulations with coarse-grained force fields often employ extremely large time steps, we also investigate the influence of time step on dynamical properties. We observe a systematic acceleration of system dynamics when increasing the time step. Carefully monitoring energy/temperature conservation is found to be a sufficient criterion for the reliable calculation of dynamical properties. By contrast, recommended criteria based on the ratio of fluctuations of total vs. kinetic energy are not sensitive enough.

  3. Ultrafast spontaneous emission modulation of graphene quantum dots interacting with Ag nanoparticles in solution

    Science.gov (United States)

    Zhao, Jianwei; Lu, Jian; Wang, Liang; Tian, Linfan; Deng, Xingxia; Tian, Lijun; Pan, Dengyu; Wang, Zhongyang

    2016-07-01

    We investigated the strong interaction between graphene quantum dots and silver nanoparticles in solution using time-resolved photoluminescence techniques. In solution, the silver nanoparticles are surrounded by graphene quantum dots and interacted with graphene quantum dots through exciton-plasmon coupling. An ultrafast spontaneous emission process (lifetime 27 ps) was observed in such a mixed solution. This ultrafast lifetime corresponds to the emission rate exceeding 35 GHz, with the purcell enhancement by a factor of ˜12. These experiment results pave the way for the realization of future high speed light sources applications.

  4. Observation of Rabi Splitting from Surface-plasmon Coupled Conduction-state Transitions in Electrically-excited InAs Quantum Dots

    Energy Technology Data Exchange (ETDEWEB)

    Passmore, Brian S.; Adams, David C.; Ribaudo, Troy; Wasserman, Daniel; Lyon, Stephen; Chow, Weng W.; Shaner, Eric A.

    2011-02-09

    We demonstrate strong coupling between a surface plasmon and intersublevel transitions in self-assembled InAs quantum dots. The surface plasmon mode exists at the interface between the semiconductor emitter structure and a periodic array of holes perforating a metallic Pd/Ge/Au film that also serves as the top electrical contact for the emitters. Spectrally narrowed quantum-dot electroluminescence was observed for devices with varying subwavelength hole spacing. Devices designed for 9, 10, and 11 μm wavelength emission also exhibit a significant spectral splitting. The association of the splitting with quantum-dot Rabi oscillation is consistent with results from a calculation of spontaneous emission from an interacting plasmonic field and quantum-dot ensemble. The fact that this Rabi oscillation can be observed in an incoherently excited, highly inhomogeneously broadened system demonstrates the utility of intersublevel transitions in quantum dots for investigations of coherent transient and quantum coherence phenomena.

  5. Unidirectional enhanced spontaneous emission with metallo-dielectric optical antenna

    Science.gov (United States)

    Shen, Hongming; Lu, Guowei; He, Yingbo; Cheng, Yuqing; Gong, Qihuang

    2017-07-01

    A metallo-dielectric system consisted of two coupled metallic nanoparticles embedded in a planar dielectric antenna is proposed to control the light emission from a localized emitter. Such design integrates the advantages of planar dielectric antenna and plasmonic antenna such as highly localized excitation enhancement, emission direction control, and high collection efficiency. For specific configurations, the antenna can achieve unidirectional and plasmon-enhanced emission from single emitters, simultaneously presenting remarkable collection efficiency up to 96%. We show that the unidirectional effect is mainly determined by the plasmon coupling effect of the plasmonic dimer. The dependences of directivity property on the antenna geometry and emitter's position are also discussed in detail. These findings provide a promising route to realize novel optical devices involving directional and surface enhanced spontaneous emission, e.g. bright single-photon sources with high collection efficiency.

  6. Investigation of surface-plasmon coupled red light emitting InGaN/GaN multi-quantum well with Ag nanostructures coated on GaN surface

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Liu, Bin, E-mail: bliu@nju.edu.cn, E-mail: rzhang@nju.edu.cn; Zhang, Rong, E-mail: bliu@nju.edu.cn, E-mail: rzhang@nju.edu.cn; Xie, Zili; Zhuang, Zhe; Dai, JiangPing; Tao, Tao; Zhi, Ting; Zhang, Guogang; Chen, Peng; Ren, Fangfang; Zhao, Hong; Zheng, Youdou [Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, People' s Republic of China and Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-04-21

    Surface-plasmon (SP) coupled red light emitting InGaN/GaN multiple quantum well (MQW) structure is fabricated and investigated. The centre wavelength of 5-period InGaN/GaN MQW structure is about 620 nm. The intensity of photoluminescence (PL) for InGaN QW with naked Ag nano-structures (NS) is only slightly increased due to the oxidation of Ag NS as compared to that for the InGaN QW. However, InGaN QW with Ag NS/SiO{sub 2} structure can evidently enhance the emission efficiency due to the elimination of surface oxide layer of Ag NS. With increasing the laser excitation power, the PL intensity is enhanced by 25%–53% as compared to that for the SiO{sub 2} coating InGaN QW. The steady-state electric field distribution obtained by the three-dimensional finite-difference time-domain method is different for both structures. The proportion of the field distributed in the Ag NS for the GaN/Ag NS/SiO{sub 2} structure is smaller as compared to that for the GaN/naked Ag NS structure. As a result, the energy loss of localized SP modes for the GaN/naked Ag NS structure will be larger due to the absorption of Ag layer.

  7. Plasmonic Coupled Cavities on Moire Surfaces

    Science.gov (United States)

    Balci, Sinan; Kocabas, Askin; Karabiyik, Mustafa; Kocabas, Coskun; Aydinli, Atilla

    2010-03-01

    We investigate surface plasmon polariton (SPP) coupled cavity modes on Moire surfaces. An experimental study has been made of the propagation of SPPs on a thin silver surface that is textured with Moire surface pattern using interference lithography. The Moire surface contains periodic array of one dimensional cavities. The distance between the cavities can be controlled by changing the periodicities of Moire surface. When the SPP cavity separation is sufficiently small, we show splitting of strongly coupled plasmonic cavity modes through numerical simulations. Conversely, when the SPP cavity separation is sufficiently large, SPP cavity modes are found to be localized and do not show splitting of SPP cavity modes . This splitting of SPP cavity modes are well explained with a tight binding model that has been succesfully applied in photonic coupled cavities. Reflection measurements and numerical simulation of a large number of adjacent SPP cavities have shown a coupled resonator optical waveguide (CROW) type plasmonic waveguide band formation within the band gap region of unperturbed uniform grating.

  8. 基于61单片机的藏式特色太阳能智能路灯系统的设计与实现%Design and implementation of Tibetan intelligent solar streetlight system based on SPCE061A

    Institute of Scientific and Technical Information of China (English)

    邓利华; 武强; 梅卫龙; 肖瑶

    2012-01-01

    为使西藏各主要道路管理更加智能化,提高路灯系统的工作效率,本文结合太阳能与SPCE061A单片机实现了藏式特色太阳能智能路灯系统的设计。本项目通过太阳能给各硬件部分供电。SPCE061A控制采样函数,并利用LCD显示采样数据的相关信息,同时根据红外感应和相邻通信技术实现对副灯亮灭的控制。本文设计的藏式特色太阳能智能路灯系统具有安全环保、功耗低、外观设计具有藏式特色、实用性强,性能稳定、人性化等优点。%To manage Tibetan main roads more intelligent and improve the efficiency of the streetlight system, this paper implements solar intelligent streetligbt system based on solar energy and SPCE061A.The project provides power supply to the hardware by solar, and uses SPCE061A to control sampling function and display the sampling data with LCD, meanwhile to control the auxiliary lamp brightness based on infrared sensors and adjacent communications technology. The Tibetan solar intelligent streetlight system has safety, environmental protection, low power consumption, stable performance and design with Tibet characteristics, practical, stable performance, user-friendly advantages etc.

  9. Effect of plasmonic losses on light emission enhancement in quantum-wells coupled to metallic gratings

    Science.gov (United States)

    Sadi, Toufik; Oksanen, Jani; Tulkki, Jukka

    2013-12-01

    Recent experimental work has shown significant luminescence enhancement from near-surface quantum-well (QW) structures using metallic grating to convert surface plasmon (SP) modes into radiative modes. This work introduces a detailed theoretical study of plasmonic losses and the role of SPs in improving light extraction from grated light-emitting QW structures, using the fluctuational electrodynamics method. The method explains experimental results demonstrating emission enhancement, light scattering, and plasmonic coupling in the structures. We study these effects in angle-resolved reflectometry and luminescence setups in InGaN QW structures with silver grating. In contrast to experiments, our model allows direct calculation of the optical losses. The model predicts that the plasmonic coupling and scattering increases light emission by a factor of up to three compared to a flat semiconductor structure. This corresponds to reducing the absorption losses from approximately 93% in the ungrated metallic structure to 75% in the grated structure. Lower losses are associated with a significant emission enhancement enabled by the SPs of silver/GaN interfaces, which are present in the blue/green wavelength range, and can be optimized by carefully nanostructuring the metal layer and by the positioning of the QW. In general, the enhancement results from the interplay of mode scattering, conversion of SP energy directly into light, and losses in the metallic grating. The reported losses are very high when compared to the losses present in modern light-emitting diodes (LEDs). Albeit, our work provides tools needed for further optimization of plasmonic light extraction, eventually leading to highly efficient LEDs.

  10. 2009 S. Atlantic SPCE angler pilot survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This survey collected information to assess the economic value from an anglers perspective of saltwater charter and private boat fishing for selected species in...

  11. 2013 Gulf of Mexico SPCE angler survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This survey provides economic data related to marine recreational fishing in the Gulf of Mexico. The data collected include preference and opinion information...

  12. Coarse-Graining of TIP4P/2005, TIP4P-Ew, SPC/E, and TIP3P to Monatomic Anisotropic Water Models Using Relative Entropy Minimization.

    Science.gov (United States)

    Lu, Jibao; Qiu, Yuqing; Baron, Riccardo; Molinero, Valeria

    2014-09-09

    Coarse-grained models are becoming a competitive alternative for modeling processes that occur over time and length scales beyond the reach of fully atomistic molecular simulations. Ideally, coarse-grained models should not only achieve high computational efficiency but also provide accurate predictions and fundamental insight into the role of molecular interactions, the characteristic behavior, and properties of the system they model. In this work we derive a series of monatomic coarse-grained water models mX(REM) from the most popular atomistic water models X = TIP3P, SPC/E, TIP4P-Ew, and TIP4P/2005, using the relative entropy minimization (REM) method. Each coarse-grained water molecule is represented by a single particle that interacts through short-ranged anisotropic interactions that encourage the formation of "hydrogen-bonded" structures. We systematically investigate the features of the coarse-grained models in reproducing over 20 structural, dynamic, and thermodynamic properties of the reference atomistic water models-including the existence and locus of the characteristic density anomaly. The mX(REM) coarse-grained models reproduce quite faithfully the radial and angular distribution function of water, produce a temperature of maximum density (TMD), and stabilize the ice I crystal. Moreover, the ratio between the TMD and the melting temperature of the crystal in the mX(REM) models and liquid-ice equilibrium properties show reasonable agreement with the results of the corresponding atomistic models. The mX(REM) models, however, severely underestimate the cohesive energy of the condensed water phases. We investigate which specific limitations of the coarse-grained models arise from the REM methodology, from the monatomic nature of the models, and from the Stillinger-Weber interaction potential form. Our analysis indicates that a small compromise in the accuracy of structural properties can result in a significant increase of the overall accuracy and

  13. Optical investigation of gold shell enhanced 25 nm diameter upconverted fluorescence emission

    Science.gov (United States)

    Green, Kory; Wirth, Janina; Lim, Shuang Fang

    2016-04-01

    We enhance the efficiency of upconverting nanoparticles by investigating the plasmonic coupling of 25 nm diameter NaYF4:Yb, Er nanoparticles with a gold-shell coating, and study the physical mechanism of enhancement by single-particle, time-resolved spectroscopy. A three-fold overall increase in emission intensity, and five-fold increase of green emission for these plasmonically enhanced particles have been achieved. Using a combination of structural and fluorescent imaging, we demonstrate that fluorescence enhancement is based on the photonic properties of single, isolated particles. Time-resolved spectroscopy shows that the increase in fluorescence is coincident with decreased rise time, which we attribute to an enhanced absorption of infrared light and energy transfer from Yb3+ to Er3+ atoms. Time-resolved spectroscopy also shows that fluorescence life-times are decreased to different extents for red and green emission. This indicates that the rate of photon emission is not suppressed, as would be expected for a metallic cavity, but rather enhanced because the metal shell acts as an optical antenna, with differing efficiency at different wavelengths.

  14. Direct Photonic-Plasmonic Coupling and Routing in Single Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Rouxue; Pausauskie, Peter; Huang, Jiaxing; Yang, Piedong

    2009-10-20

    Metallic nanoscale structures are capable of supporting surface plasmon polaritons (SPPs), propagating collective electron oscillations with tight spatial confinement at the metal surface. SPPs represent one of the most promising structures to beat the diffraction limit imposed by conventional dielectric optics. Ag nano wires have drawn increasing research attention due to 2D sub-100 nm mode confinement and lower losses as compared with fabricated metal structures. However, rational and versatile integration of Ag nanowires with other active and passive optical components, as well as Ag nanowire based optical routing networks, has yet to be achieved. Here, we demonstrate that SPPs can be excited simply by contacting a silver nanowire with a SnO2 nanoribbon that serves both as an unpolarized light source and a dielectric waveguide. The efficient coupling makes it possible to measure the propagation-distance-dependent waveguide spectra and frequency-dependent propagation length on a single Ag nanowire. Furthermore, we have demonstrated prototypical photonic-plasmonic routing devices, which are essential for incorporating low-loss Ag nanowire waveguides as practical components into high-capacity photonic circuits.

  15. Plasmon coupling of magnetic resonances in an asymmetric gold semishell

    Science.gov (United States)

    Ye, Jian; Kong, Yan; Liu, Cheng

    2016-05-01

    The generation of magnetic dipole resonances in metallic nanostructures is of great importance for constructing near-zero or even negative refractive index metamaterials. Commonly, planar two-dimensional (2D) split-ring resonators or relevant structures are basic elements of metamaterials. In this work, we introduce a three-dimensional (3D) asymmetric Au semishell composed of two nanocups with a face-to-face geometry and demonstrate two distinct magnetic resonances spontaneously in the visible-near infrared optical wavelength regime. These two magnetic resonances are from constructive and destructive hybridization of magnetic dipoles of individual nanocups in the asymmetric semishell. In contrast, complete cancellation of magnetic dipoles in the symmetric semishell leads to only a pronounced electric mode with near-zero magnetic dipole moment. These 3D asymmetric resonators provide new ways for engineering hybrid resonant modes and ultra-high near-field enhancement for the design of 3D metamaterials.

  16. UV Nano-Lights: Nonlinear Quantum Dot-Plasmon Coupling

    Science.gov (United States)

    2014-08-01

    method is also applicable to bare nanoparticles in polar solvents. 15. SUBJECT TERMS Quantum Dots, Nonlinear Optical Materials , Energy...TERMS Quantum Dots, Nonlinear Optical Materials , Energy Conservation, Up-conversion 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT

  17. Plasmonic Coupling on Dielectric Nanowire Core-Metal Sheath Composites

    Science.gov (United States)

    2010-01-01

    is still a serious issue. Here, an approach based on a redox chemical reaction of silver plating is explored, which could potentially solve the...problems related to incomplete metal coverage of the nanowires. It is known that the Tollens reaction is a silvering process often used to qualitatively...the extra Sn2 + ions were removed by a deionized water rinse, keeping the surface wet. Thus, Sn2 + ions were absorbed on the surface of the ZnO NWs via

  18. Plasmonic Effect on Exciton and Multiexciton Emission of Single Quantum Dots.

    Science.gov (United States)

    Dey, Swayandipta; Zhao, Jing

    2016-08-04

    Quantum dots are nanoscale quantum emitters with high quantum yield and size-dependent emission wavelength, holding promises in many optical and electronic applications. When quantum dots are situated close to noble metal nanoparticles, their emitting behavior can be conveniently tuned because of the interaction between the excitons of the quantum dots and the plasmons of the metal nanoparticles. This interaction at the single quantum dot level gives rise to reduced or suppressed photoluminescence blinking and enhanced multiexciton emission, which is difficult to achieve in isolated quantum dots. However, the mechanism of how plasmonic structures cause the changes in the quantum dot emission remains unclear. Because of the complexity of the system, the interfaces between metal, semiconductor, and ligands must be considered, in addition to factors such as geometry, interparticle distance, and spectral overlap. The challenges in the design and fabrication of the hybrid nanostructures as well as in understanding the exciton-plasmon coupling mechanism can be overcome by a cooperative effort in synthesis, optical spectroscopy, and theoretical modeling.

  19. Enhanced two-photon emission in coupled metal nanoparticles induced by conjugated polymers.

    Science.gov (United States)

    Guan, Zhenping; Polavarapu, Lakshminarayana; Xu, Qing-Hua

    2010-12-01

    Interactions between noble metal (Ag and Au) nanoparticles and conjugated polymers as well as their one- and two-photon emission have been investigated. Ag and Au nanoparticles exhibited extraordinary quenching effects on the fluorescence of cationic poly(fluorinephenylene). The quenching efficiency by 37-nm Ag nanoparticles is ∼19 times more efficient than that by 13-nm Au nanoparticles, and 9-10 orders of magnitude more efficient than typical small molecule dye-quencher pairs. On the other hand, the cationic conjugated polymers induce the aggregate formation and plasmonic coupling of the metal nanoparticles, as evidenced by transmission electron microscopy images and appearance of a new longitudinal plasmon band in the near-infrared region. The two-photon emissions of Ag and Au nanoparticles were found to be significantly enhanced upon addition of conjugated polymers, by a factor of 51-times and 9-times compared to the isolated nanoparticles for Ag and Au, respectively. These studies could be further extended to the applications of two-photon imaging and sensing of the analytes that can induce formation of metal nanoparticle aggregates, which have many advantages over the conventional one-photon counterparts.

  20. Emission Trading

    OpenAIRE

    2009-01-01

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

  1. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

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

  2. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

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

  3. Emission Facilities - Air Emission Plants

    Data.gov (United States)

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

  4. Emission Facilities - Air Emission Plants

    Data.gov (United States)

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

  5. Emission inventory; Inventaire des emissions

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  6. Strong phonon-plasmon coupled modes in the graphene/silicon carbide heterosystem

    Science.gov (United States)

    Koch, R. J.; Seyller, Th.; Schaefer, J. A.

    2010-11-01

    We report on strong coupling of the charge-carrier plasmon ωPL in graphene with the surface-optical phonon ωSO of the underlying SiC(0001) substrate with low-electron concentration (n=1.2×1015cm-3) in the long-wavelength limit (q∥→0) . Energy-dependent energy-loss spectra give clear evidence of two coupled phonon-plasmon modes ω± separated by a gap between ωSO(q∥→0) and ωTO(q∥≫0) , the transverse-optical-phonon mode, in particular, for higher primary electron energies (E0≥20eV) . A simplified model based on dielectric theory is able to simulate our energy-loss spectra as well as the dispersion of the two coupled phonon-plasmon modes ω± . In contrast, Liu and Willis [Phys. Rev. B 81, 081406(R) (2010)]10.1103/PhysRevB.81.081406 postulate in their recent publication no gap and a discontinuous dispersion curve with a one-peak structure from their energy-loss data.

  7. Slowing surface plasmon polaritons on plasmonic coupled cavities by tuning grating grooves

    Science.gov (United States)

    Balci, Sinan; Kocabas, Askin; Kocabas, Coskun; Aydinli, Atilla

    2010-09-01

    We investigate slow surface plasmon polaritons (SPPs) in plasmonic waveguiding bands formed by coupled plasmonic cavities on Moiré surfaces. We demonstrate controlling the group velocity and dispersion of the SPPs by varying the depth of the plasmonic Bragg grating groove. Changing the grating depth results in modification of coupling coefficients between the cavities and hence the SPPs group velocity is altered. Variation in the group velocity and dispersion of SPPs can be measured with polarization dependent spectroscopic reflection measurements. Dispersion of SPPs has been calculated by finite-difference time-domain method in agreement with the experimental data.

  8. Impact of the Nanoscale Gap Morphology on the Plasmon Coupling in Asymmetric Nanoparticle Dimer Antennas.

    Science.gov (United States)

    Popp, Paul S; Herrmann, Janning F; Fritz, Eva-Corinna; Ravoo, Bart Jan; Höppener, Christiane

    2016-03-23

    Coupling of plasmon resonances in metallic gap antennas is of interest for a wide range of applications due to the highly localized strong electric fields supported by these structures, and their high sensitivity to alterations of their structure, geometry, and environment. Morphological alterations of asymmetric nanoparticle dimer antennas with (sub)-nanometer size gaps are assigned to changes of their optical response in correlative dark-field spectroscopy and high-resolution transmission electron microscopy (HR-TEM) investigations. This multimodal approach to investigate individual dimer structures clearly demonstrates that the coupling of the plasmon modes, in addition to well-known parameters such as the particle geometry and the gap size, is also affected by the relative alignment of both nanoparticles. The investigations corroborate that the alignment of the gap forming facets, and with that the gap area, is crucial for their scattering properties. The impact of a flat versus a rounded gap structure on the optical properties of equivalent dimers becomes stronger with decreasing gap size. These results hint at a higher confinement of the electric field in the gap and possibly a different onset of quantum transport effects for flat and rounded gap antennas in corresponding structures for very narrow gaps.

  9. Graphene-Hexagonal Boron Nitride Heterostructure as a Tunable Phonon–Plasmon Coupling System

    Directory of Open Access Journals (Sweden)

    Sheng Qu

    2017-02-01

    Full Text Available The layered van der Waals (vdW heterostructure, assembled from monolayer graphene, hexagonal boron nitride (h-BN and other atomic crystals in various combinations, is emerging as a new paradigm with which to attain desired electronic and optical properties. In this paper, we study theoretically the mid-infrared optical properties of the vdW heterostructure based on the graphene–h-BN system. The light–matter interaction of this heterostructure system is described by the hyperbolic phonon–plasmon polaritons which originate from the coupling modes of surface plasmon polaritons (SPPs in graphene with hyperbolic phonon polaritons (HPPs in h-BN. By numerical simulation, we find that the coupling modes are governed by the Fermi level of monolayer graphene, the thickness of the h-BN slab and the mode excitation sequence of SPPs and HPPs. Moreover, the response of the coupling modes of the graphene–h-BN heterostructure on a noble metal layer is also proposed in this paper.

  10. Enhancing spectral shifts of plasmon-coupled noble metal nanoparticles for sensing applications

    NARCIS (Netherlands)

    Goeken, K.L.; Subramaniam, V.; Gill, R.

    2015-01-01

    Noble metal nanoparticles possess very large scattering cross-sections, which make them useful as tags in biosensing assays with the potential to detect even single binding events. In this study, we investigated the effects of nanoparticle size on the shift in the light scattering spectrum following

  11. Robust Phonon-Plasmon Coupling in Quasifreestanding Graphene on Silicon Carbide.

    Science.gov (United States)

    Koch, R J; Fryska, S; Ostler, M; Endlich, M; Speck, F; Hänsel, T; Schaefer, J A; Seyller, Th

    2016-03-11

    Using inelastic electron scattering in combination with dielectric theory simulations on differently prepared graphene layers on silicon carbide, we demonstrate that the coupling between the 2D plasmon of graphene and the surface optical phonon of the substrate cannot be quenched by modification of the interface via intercalation. The intercalation rather provides additional modes like, e.g., the silicon-hydrogen stretch mode in the case of hydrogen intercalation or the silicon-oxygen vibrations for water intercalation that couple to the 2D plasmons of graphene. Furthermore, in the case of bilayer graphene with broken inversion symmetry due to charge imbalance between the layers, we observe a similar coupling of the 2D plasmon to an internal infrared-active mode, the LO phonon mode. The coupling of graphene plasmons to vibrational modes of the substrate surface and internal infrared active modes is envisioned to provide an excellent tool for tailoring the plasmon band structure of monolayer and bilayer graphene for plasmonic devices such as plasmon filters or plasmonic waveguides. The rigidity of the effect furthermore suggests that it may be of importance for other 2D materials as well.

  12. pH-Triggered SERS via Modulated Plasmonic Coupling in Individual Bimetallic Nanocobs

    Science.gov (United States)

    2011-01-01

    I. H. El-Sayed , M. A. El-Sayed , J. Phys. Chem. B 2006 , 110 , 7238 – 7248 . [ 7 ] R. A. Alvarez- Puebla , L. M. Liz-Marzan , Energy...S. Markutsya , V. V. Tsukruk , Langmuir 2004 , 20 , 882 – 890 . [ 10 ] R. A. Alvarez- Puebla , L. M. Liz-Marzán , Small 2010 , 6

  13. Laser Induced Periodic Surface Structures induced by surface plasmons coupled via roughness

    Science.gov (United States)

    Gurevich, E. L.; Gurevich, S. V.

    2014-05-01

    In this paper the formation mechanisms of the femtosecond laser-induced periodic surface structures (LIPSS) are discussed. One of the most frequently used theories explains the structures by interference between the incident laser beam and surface plasmon-polariton waves. The latter is most commonly attributed to the coupling of the incident laser light to the surface roughness. We demonstrate that this excitation of surface plasmons contradicts the results of laser-ablation experiments. As an alternative approach to the excitation of LIPSS we analyse development of hydrodynamic instabilities in the melt layer.

  14. High modulation bandwidth of a light-emitting diode with surface plasmon coupling (Conference Presentation)

    Science.gov (United States)

    Lin, Chun-Han; Tu, Charng-Gan; Yao, Yu-Feng; Chen, Sheng-Hung; Su, Chia-Ying; Chen, Hao-Tsung; Kiang, Yean-Woei; Yang, Chih-Chung

    2017-02-01

    Besides lighting, LEDs can be used for indoor data transmission. Therefore, a large modulation bandwidth becomes an important target in the development of visible LED. In this regard, enhancing the radiative recombination rate of carriers in the quantum wells of an LED is a useful method since the modulation bandwidth of an LED is related to the carrier decay rate besides the device RC time constant To increase the carrier decay rate in an LED without sacrificing its output power, the technique of surface plasmon (SP) coupling in an LED is useful. In this paper, the increases of modulation bandwidth by reducing mesa size, decreasing active layer thickness, and inducing SP coupling in blue- and green-emitting LEDs are illustrated. The results are demonstrated by comparing three different LED surface structures, including bare p-type surface, GaZnO current spreading layer, and Ag nanoparticles (NPs) for inducing SP coupling. In a single-quantum-well, blue-emitting LED with a circular mesa of 10 microns in radius, SP coupling results in a modulation bandwidth of 528.8 MHz, which is believed to be the record-high level. A smaller RC time constant can lead to a higher modulation bandwidth. However, when the RC time constant is smaller than 0.2 ns, its effect on modulation bandwidth saturates. The dependencies of modulation bandwidth on injected current density and carrier decay time confirm that the modulation bandwidth is essentially inversely proportional to a time constant, which is inversely proportional to the square-root of carrier decay rate and injected current density.

  15. Localized plasmon-coupled semiconductor nanocrystal emitters for innovative device applications

    OpenAIRE

    Soğancı, İbrahim Murat

    2007-01-01

    Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent University, 2007. Thesis (Master's) -- Bilkent University, 2007. Includes bibliographical references leaves 74-83 Quantum confinement allows for the development of novel luminescent materials such as colloidal semiconductor quantum dots for a variety of photonic applications spanning from biomedical labeling to white light generation. However, such devic...

  16. Laser Induced Periodic Surface Structures induced by surface plasmons coupled via roughness

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, E.L., E-mail: gurevich@lat.rub.de [Chair of Applied Laser Technology, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum (Germany); Gurevich, S.V., E-mail: gurevics@uni-muenster.de [Institute for Theoretical Physics, University of Münster, Wilhelm-Klemm-Straße 9, 48149 Münster (Germany)

    2014-05-01

    In this paper the formation mechanisms of the femtosecond laser-induced periodic surface structures (LIPSS) are discussed. One of the most frequently used theories explains the structures by interference between the incident laser beam and surface plasmon-polariton waves. The latter is most commonly attributed to the coupling of the incident laser light to the surface roughness. We demonstrate that this excitation of surface plasmons contradicts the results of laser-ablation experiments. As an alternative approach to the excitation of LIPSS we analyse development of hydrodynamic instabilities in the melt layer.

  17. Emission Inventory for Fugitive Emissions in Denmark

    DEFF Research Database (Denmark)

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

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

  18. Ion cyclotron emission by spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

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

  19. Ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2012-01-01

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

  20. Emissions Modeling Clearinghouse

    Data.gov (United States)

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

  1. Walkable dual emissions

    National Research Council Canada - National Science Library

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

    2013-01-01

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

  2. National Emission Inventory

    Data.gov (United States)

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

  3. World Emission RETRO ANTHRO

    Data.gov (United States)

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

  4. Emissions & Measurements - Black Carbon

    Science.gov (United States)

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

  5. What Is Emissions Trading?

    Science.gov (United States)

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

  6. National Emission Inventory

    Data.gov (United States)

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

  7. Shipping emissions in ports

    OpenAIRE

    2014-01-01

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

  8. International emissions trading

    DEFF Research Database (Denmark)

    Boom, Jan Tjeerd

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

  9. Anomalous Microwave Emission

    CERN Document Server

    Kogut, A J

    1999-01-01

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

  10. Global Seabird Ammonia Emissions

    Science.gov (United States)

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

    2010-12-01

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

  11. Carbon emissions Inventory Games

    OpenAIRE

    Al-Emadi, Eiman Ali

    2016-01-01

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

  12. Managing Refrigerant Emissions

    Science.gov (United States)

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

  13. VOC emissions chambers

    Data.gov (United States)

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

  14. Microgravity Emissions Laboratory (MEL)

    Data.gov (United States)

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

  15. Toluene emissions from plants

    Science.gov (United States)

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

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

  16. Outsourcing CO2 Emissions

    Science.gov (United States)

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

    2009-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Zohner, Steven K

    2000-05-01

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

  18. Database of emission lines

    Science.gov (United States)

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

    1998-11-01

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

  19. Uncertainties in emission inventories

    NARCIS (Netherlands)

    Aardenne, van J.A.

    2002-01-01

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

  20. India Co2 Emissions

    Science.gov (United States)

    Sharan, S.; Diffenbaugh, N. S.

    2010-12-01

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

  1. National Greenhouse Gas Emission Inventory

    Data.gov (United States)

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

  2. Emissivity of microstructured silicon.

    Science.gov (United States)

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

    2010-03-01

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

  3. 2011 NATA - Emissions Sources

    Data.gov (United States)

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

  4. Ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2012-01-01

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

  5. National Emission Inventory (NEI)

    Data.gov (United States)

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

  6. Galactic Diffuse Polarized Emission

    Indian Academy of Sciences (India)

    Ettore Carretti

    2011-12-01

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

  7. Field emission electron source

    Science.gov (United States)

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

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

  8. Electron Emission Projection Imager

    CERN Document Server

    Baturin, Stanislav S

    2016-01-01

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

  9. 47 CFR 78.103 - Emissions and emission limitations.

    Science.gov (United States)

    2010-10-01

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

  10. Emissions trading: principles and practice

    National Research Council Canada - National Science Library

    Tietenberg, T.H

    2006-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 The Evolution of Emissions Trading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 The Evolution of Design Features...

  11. Plexciton Dynamics: Exciton-Plasmon Coupling in a J-Aggregate-Au Nanoshell Complex Provides a Mechanism for Nonlinearity

    Energy Technology Data Exchange (ETDEWEB)

    Fofang, Nche T. [Rice Univ., Houston, TX (United States); Grady, Nathaniel K. [Rice Univ., Houston, TX (United States); Fan, Zhiyuan [Ohio Univ., Athens, OH (United States); Govorov, Alexander [Ohio Univ., Athens, OH (United States); Halas, Naomi J. [Rice Univ., Houston, TX (United States)

    2011-03-18

    Coherently coupled plasmons and excitons give rise to new optical excitations- plexcitons - due to the strong coupling of these two oscillator systems. Time-resolved studies of J-aggregate-Au nanoshell complexes when the nanoshell plasmon and J-aggregate exciton energies are degenerate probe the dynamical behavior of this coupled system. Transient absorption of the interacting plasmon-exciton system is observed, in dramatic contrast to the photoinduced transmission of the pristine J-aggregate. An additional, transient Fano-shaped modulation within the Fano dip is also observable. The behavior of the J-aggregate-Au nanoshell complex is described by a combined one-exciton and two-exciton state model coupled to the nanoshell plasmon.

  12. Multiple Resonances Induced by Plasmonic Coupling between Gold Nanoparticle Trimers and Hexagonal Assembly of Gold-Coated Polystyrene Microspheres.

    Science.gov (United States)

    Uchida, Takako; Yoshikawa, Takayasu; Tamura, Mamoru; Iida, Takuya; Imura, Kohei

    2016-09-15

    Optical properties of a gold nanoparticle trimer assembly coupled with gold-coated hexagonally close-packed polystyrene microspheres were investigated by linear and nonlinear spectroscopy. The observed reflection spectrum shows multiple peaks from the visible to near-infrared spectral regions. The spectroscopic properties were also examined by a finite-difference time-domain simulation. We found that the optical response of plasmons excited in the gold nanoparticle trimers was significantly modulated by strong coupling of the plasmons and the photonic mode induced in the gold-coated polystyrene assembly. Two-photon induced photoluminescence and Raman scattering from the sample were investigated, and both signals were significantly enhanced at the gold nanoparticle assembly. The simulations reveal that the electric fields can be enhanced site-selectively, not only at the interstitial sites in the nanoparticle assembly but also at the gaps between the particle and the gold film due to plasmonic interactions, by tuning the wavelength and are responsible for the strong optical responses.

  13. Identification of surface oxygen vacancy-related phonon-plasmon coupling in TiO2 single crystal

    Science.gov (United States)

    Guo, Jun-Hong; Li, Ting-Hui; Hu, Fang-Ren; Liu, Li-Zhe

    2016-12-01

    Oxygen vacancies (OVs) play a critical role in the physical properties and applications of titanium dioxide nanostructures, which are widely used in electrochemistry and photo catalysis nowadays. In this work, OVs were artificially introduced in the surface of a pure TiO2 single crystal by pulsed laser irradiation. Raman spectra showed that the intensity of Eg mode was enhanced. Theoretical calculations disclose that this was caused by the strong coupling effect between the phonon vibration and plasmon induced by the OVs-related surface deformation, and good agreement was achieved between the experiments and theory. Project supported by the National Natural Science Foundation of China (Grant Nos. 61574080, 11404162, 61505085, and 61264008) and the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20130549).

  14. The plasmonic coupling of metal nanoparticles and its implication for scanning near-field optical microscope characterization

    Institute of Scientific and Technical Information of China (English)

    LI Zhi; GONG QiHuang

    2009-01-01

    @@ Researchers at State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University (PKU), have recently shown that an otherwise forbid-den longitudinal surface plasmon mode of a gold nanorod can be excited by nor-mally incident linearly-polarized light if it is coupled with a nanoparticle with proper plasmonic resonant frequency, volume, and composition~([1]).

  15. Emission control system

    Science.gov (United States)

    Parrish, Clyde F. (Inventor); Chung, J. Landy (Inventor)

    2009-01-01

    Methods and apparatus utilizing hydrogen peroxide are useful to reduce SOx and mercury (or other heavy metal) emissions from combustion flue gas streams. The methods and apparatus may further be modified to reduce NOx emissions. Continuous concentration of hydrogen peroxide to levels approaching or exceeding propellant-grade hydrogen peroxide facilitates increased system efficiency. In this manner, combustion flue gas streams can be treated for the removal of SOx and heavy metals, while isolating useful by-products streams of sulfuric acid as well as solids for the recovery of the heavy metals. Where removal of NOx emissions is included, nitric acid may also be isolated for use in fertilizer or other industrial applications.

  16. Practical acoustic emission testing

    CERN Document Server

    2016-01-01

    This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

  17. Field emission electronics

    CERN Document Server

    Egorov, Nikolay

    2017-01-01

    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  18. Mercury emission from crematoria.

    Science.gov (United States)

    Santarsiero, Anna; Settimo, Gaetano; Dell'andrea, Elena

    2006-01-01

    The purpose of this study, undertaken at a cremator representing an example of current equipment and cremation practices in use in Italy, is to assess the possible mercury emitted during cremation and substantiate the current data available. This paper reports some preliminary results concerning mercury and total particulate matter emissions during three cremation processes. The obtained results gave a mercury concentration ranging from 0.005 to 0.300 mg/m3 and a mercury emission factor ranging from 0.036 to 2.140 g/corpse cremated. The total particulate matter concentration range was 1.0 to 2.4 mg/m3.

  19. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has onl...

  20. Controlling spontaneous emission

    DEFF Research Database (Denmark)

    Lodahl, Peter

    dots (QDs) embedded in 3D photonic crystals consisting of air spheres in titanium dioxide. Performing time-resolved experiments, we show that the photonic crystals control the emission decay rate of excitons confined in the QDs1,2. By varying the lattice parameter of the photonic crystals, we...

  1. Aircraft Emissions Characterization

    Science.gov (United States)

    1988-03-01

    sample from each trap through a heated (1500C) six-port valve ’ Carle Instruments Model 5621) and onto the analytical column. The coLoponents in each...Environmental Protection, Vol. II. Aircraft Engine Emissions, Int. Civil Aviation Organ., 1981. 7. Nebel , G. J., "Benzene in Auto Exhaust," J. Air Poll

  2. Reaching peak emissions

    Science.gov (United States)

    Jackson, Robert B.; Canadell, Josep G.; Le Quéré, Corinne; Andrew, Robbie M.; Korsbakken, Jan Ivar; Peters, Glen P.; Nakicenovic, Nebojsa

    2016-01-01

    Rapid growth in global CO2 emissions from fossil fuels and industry ceased in the past two years, despite continued economic growth. Decreased coal use in China was largely responsible, coupled with slower global growth in petroleum and faster growth in renewables.

  3. Radio Emission from Exoplanets

    OpenAIRE

    George, Samuel J.; Stevens, Ian R.

    2008-01-01

    We present results from new low frequency observations of two extrasolar planetary systems (Epsilon Eridani and HD128311) taken at 150 MHz with the Giant Metrewave Radio Telescope (GMRT). We do not detect either system, but are able to place tight upper limits on their low frequency radio emission.

  4. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

  5. Methane emissions from ruminants

    African Journals Online (AJOL)

    user

    2011-02-21

    Feb 21, 2011 ... Review. Livestock-environment interactions: Methane emissions from ruminants. Aluwong, T.1* ... perception of air quality by human neighbours.The three ... on the climate; the global warming potential of methane is. 21-times that of ... has serious impact on high atmosphere ozone formation. It is important ...

  6. Generalized emissivity inverse problem.

    Science.gov (United States)

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

    2002-04-01

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

  7. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has onl...... reveals presence of a true emission from all ears tested. It is concluded that the cochlear echo can be recorded in normal-hearing newborns with an extremely low rate of type I errors.......Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...... a minor effect on the power spectra, i.e. the maximum jumps from one spectral peak to another. Experiments with deconvolution demonstrate that the emission generating system at least at a fixed intensity can be regarded as being linear and characterized by its impulse response which is similar...

  8. Secondary emission gas chamber

    CERN Document Server

    In'shakov, V; Skvortsov, V

    2014-01-01

    For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

  9. Diesel emissions in Vienna

    Science.gov (United States)

    Horvath, H.; Kreiner, I.; Norek, C.; Preining, O.; Georgi, B.

    The aerosol in a non-industrial town normally is dominated by emissions from vehicles. Whereas gasoline-powered cars normally only emit a small amount of particulates, the emission by diesel-powered cars is considerable. The aerosol particles produced by diesel engines consist of graphitic carbon (GC) with attached hydrocarbons (HCs) including also polyaromatic HCs. Therefore the diesel particles can be carcinogenic. Besides diesel vehicles, all other combustion processes are also a source for GC; thus source apportionment of diesel emissions to the GC in the town is difficult. A direct apportionment of diesel emissions has been made possible by marking all the diesel fuel used by the vehicles in Vienna by a normally not occurring and easily detectable substance. All emitted diesel particles thus were marked with the tracer and by analyzing the atmospheric samples for the marking substance we found that the mass concentrations of diesel particles in the atmosphere varied between 5 and 23 μg m -3. Busy streets and calm residential areas show less difference in mass concentration than expected. The deposition of diesel particles on the ground has been determined by collecting samples from the road surface. The concentration of the marking substance was below the detection limit before the marking period and a year after the period. During the period when marked diesel fuel was used, the concentrations of the diesel particles settling to the ground was 0.012-0.07 g g -1 of collected dust. A positive correlation between the diesel vehicle density and the sampled mass of diesel vehicles exists. In Vienna we have a background diesel particle concentration of 11 μg m -3. This value increases by 5.5 μg m -3 per 500 diesel vehicles h -1 passing near the sampling location. The mass fraction of diesel particles of the total aerosol mass varied between 12.2 and 33%; the higher values were found in more remote areas, since diesel particles apparently diffuse easily

  10. Negative Emissions Technology

    Science.gov (United States)

    Day, Danny

    2006-04-01

    Although `negative emissions' of carbon dioxide need not, in principle, involve use of biological processes to draw carbon out of the atmosphere, such `agricultural' sequestration' is the only known way to remove carbon from the atmosphere on time scales comparable to the time scale for anthropogenic increases in carbon emissions. In order to maintain the `negative emissions' the biomass must be used in such a way that the resulting carbon dioxide is separated and permanently sequestered. Two options for sequestration are in the topsoil and via geologic carbon sequestration. The former has multiple benefits, but the latter also is needed. Thus, although geologic carbon sequestration is viewed skeptically by some environmentalists as simply a way to keep using fossil fuels---it may be a key part of reversing accelerating climate forcing if rapid climate change is beginning to occur. I will first review the general approach of agricultural sequestration combined with use of resulting biofuels in a way that permits carbon separation and then geologic sequestration as a negative emissions technology. Then I discuss the process that is the focus of my company---the EPRIDA cycle. If deployed at a sufficiently large scale, it could reverse the increase in CO2 concentrations. I also estimate of benefits --carbon and other---of large scale deployment of negative emissions technologies. For example, using the EPRIDA cycle by planting and soil sequestering carbon in an area abut In 3X the size of Texas would remove the amount of carbon that is being accumulated worldwide each year. In addition to the atmospheric carbon removal, the EPRIDA approach also counters the depletion of carbon in the soil---increasing topsoil and its fertility; reduces the excess nitrogen in the water by eliminating the need for ammonium nitrate fertilizer and reduces fossil fuel reliance by providing biofuel and avoiding natural gas based fertilizer production.

  11. On the Limitations of the Anomalous Microwave Emission Emissivity

    Directory of Open Access Journals (Sweden)

    Christopher T. Tibbs

    2012-01-01

    Full Text Available Many studies of anomalous microwave emission (AME have computed an AME emissivity to compare the strength of the AME detected in different regions. Such a value is usually defined as the ratio between the intensity of the AME at 1 cm and the thermal dust emission at 100 μm. However, as studies of Galactic dust emission have shown, the intensity of the thermal dust emission at 100 μm is strongly dependent on the dust temperature, which has severe implications for the AME emissivity defined in this way. In this work, we illustrate and quantify this effect and find that the AME emissivity decreases by a factor of 11.1 between dust temperatures of 20 and 30 K. We, therefore, conclude that computing the AME emissivity relative to the 100 μm emission does not allow for accurate comparisons between the AME observed in different environments. With this in mind, we investigate the use of other tracers of the dust emission with which to compute the AME emissivity and we ultimately conclude that, despite the difficulty in deriving its value, the column density of the dust would be the most suitable quantity with which to compute the AME emissivity.

  12. Phenomenology of magnetospheric radio emissions

    Science.gov (United States)

    Carr, T. D.; Desch, M. D.; Alexander, J. K.

    1983-01-01

    Jupiter has now been observed over 24 octaves of the radio spectrum, from about 0.01 MHz to 300,000 MHz. Its radio emissions fill the entire spectral region where interplanetary electromagnetic propagation is possible at wavelengths longer than infrared. Three distinct types of radiation are responsible for this radio spectrum. Thermal emission from the atmosphere accounts for virtually all the radiation at the high frequency end. Synchrotron emission from the trapped high-energy particle belt deep within the inner magnetosphere is the dominant spectral component from about 4000 to 40 MHz. The third class of radiation consists of several distinct components of sporadic low frequency emission below 40 MHz. The decimeter wavelength emission is considered, taking into account the discovery of synchrotron emission, radiation by high-energy electrons in a magnetic field, and the present status of Jovian synchrotron phenomenology. Attention is also given to the decameter and hectometer wavelength emission, and emissions at kilometric wavelengths.

  13. Carbon emission flow in networks

    National Research Council Canada - National Science Library

    Kang, Chongqing; Zhou, Tianrui; Chen, Qixin; Xu, Qianyao; Xia, Qing; Ji, Zhen

    2012-01-01

    As the human population increases and production expands, energy demand and anthropogenic carbon emission rates have been growing rapidly, and the need to decrease carbon emission levels has drawn increasing attention...

  14. Danish emission inventories for agriculture

    DEFF Research Database (Denmark)

    Mikkelsen, Mette Hjorth; Albrektsen, Rikke; Gyldenkærne, Steen

    . This report contains a description of the emissions from the agricultural sector from 1985 to 2009. Furthermore, the report includes a detailed description of methods and data used to calculate the emissions, which is based on national methodologies as well as international guidelines. For the Danish...... emissions calculations and data management an Integrated Database model for Agricultural emissions (IDA) is used. The emission from the agricultural sector includes emission of the greenhouse gases methane (CH4), nitrous oxide (N2O), ammonia (NH3), particulate matter (PM), non-methane volatile organic...... compounds (NMVOC) and other pollutants related to the field burning of agricultural residue such as NOx, CO2, CO, SO2, heavy metals, dioxin and PAH. The ammonia emission from 1985 to 2009 has decreased from 119 300 tonnes of NH3 to 73 800 tonnes NH3, corresponding to a 38 % reduction. The emission...

  15. Emission factors for passenger cars: application of instantaneous emission modeling

    Science.gov (United States)

    de Haan, Peter; Keller, Mario

    This paper discusses the use of 'instantaneous' high-resolution (1 Hz) emission data for the estimation of passenger car emissions during real-world driving. Extensive measurements of 20 EURO-I gasoline passenger cars have been used to predict emission factors for standard (i.e. legislative) as well as non-standard (i.e. real-world) driving patterns. It is shown that emission level predictions based upon chassis dynamometer tests over standard driving cycles significantly underestimate emission levels during real-world driving. The emission characteristics of modern passenger cars equipped with a three-way catalytic converter are a low, basic emission level on the one hand, and frequent emission 'peaks' on the other. For real-world driving, up to one-half of the entire emission can be emitted during these short-lasting peaks. Their frequency depends on various factors, including the level of 'dynamics' (speed variation) of the driving pattern. Because of this, the use of average speed as the only parameter to characterize emissions over a specific driving pattern is not sufficient. The instantaneous emissions approach uses an additional parameter representing engine load in order to resolve the differences between driving patterns with comparable average speeds but different levels of 'dynamics'. The paper includes an investigation of different statistical indicators and discusses methods to further improve the prediction capability of the instantaneous emission approach. The fundamental differences in emission-reduction strategies between different car manufacturers make the task of constructing a model valid for all catalyst passenger cars seemingly impossible, if the model is required to predict both fleet-averaged emission levels and emission factors for driving patterns of short duration for individual vehicles simultaneously.

  16. Future Emissions from Railway Traffic

    DEFF Research Database (Denmark)

    Sorenson, Spencer C.

    1998-01-01

    In investigation of the expected development in factors which influence railway energy consumption and emissions. Traffic factors such as train speed, load, an occupancy were considered. Tehcnical factors such an emissions factors, fleet composition and train weight were also considered. An estim......In investigation of the expected development in factors which influence railway energy consumption and emissions. Traffic factors such as train speed, load, an occupancy were considered. Tehcnical factors such an emissions factors, fleet composition and train weight were also considered...

  17. ACOUSTIC EMISSION ANALYZER

    Directory of Open Access Journals (Sweden)

    J. J. Almeida-Pérez

    2004-12-01

    Full Text Available In this paper appears a solution for acoustic emission analysis commonly known as noise. For the accomplishmentof this work a personal computer is used, besides sensors (microphones and boards designed and built for signalconditioning. These components are part of a virtual instrument used for monitoring the acoustical emission. Themain goal of this work is to develop a virtual instrument that supplies many important data as the result of ananalysis allowing to have information in an easy and friendly way. Moreover this information is very useful forstudying and resolving several situations in planning, production and testing areas.The main characteristics of the virtual instrument are: signal analysis in time, effective power measurement inDecibels (dB, average intensity taken from the principle of paired microphones, as well as the data analysis infrequency. These characteristics are included to handle two information channels.

  18. Forecasting carbon dioxide emissions.

    Science.gov (United States)

    Zhao, Xiaobing; Du, Ding

    2015-09-01

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

  19. Acoustic emission source modeling

    Directory of Open Access Journals (Sweden)

    Hora P.

    2010-07-01

    Full Text Available The paper deals with the acoustic emission (AE source modeling by means of FEM system COMSOL Multiphysics. The following types of sources are used: the spatially concentrated force and the double forces (dipole. The pulse excitation is studied in both cases. As a material is used steel. The computed displacements are compared with the exact analytical solution of point sources under consideration.

  20. Emissivity modulating electrochromic device

    Science.gov (United States)

    Demiryont, Hulya; Shannon, Kenneth C., III; Sheets, Judd

    2009-05-01

    The IR-ECDTM (Infra-Red ElectroChromic Device) variable emitance device (VED) is an all-solid-state monolithic vacuum deposited thin film system with a unique metamaterial IR transparent-electrode system which functions as an electrically controlled dimmable mirror in the IR region. The maximum reflectance corresponding to the bleached condition of the system is around 90% (low-e condition, e=0.1). The minimum reflectance reaches nearly zero in the colored condition of the system (high emittance, e=1). The average emissivity modulation of the IRECDTM is 0.7 in the 8-12 micron region, and at 9.7 micron (room temperature) it reaches a value of 0.9. Half and full emissivity modulations occur within 2 and10 minutes respectively. Because of its light weight (5g/m2), low voltage requirement (+/- 1 Volts), extremely good emissivity control properties (from 0 to 0.9 at 300K) and highly repeatable deposition process, the IR-ECDTM technology is very attractive for satellite thermal control applications. The IR-ECDTM has been under evaluation in a real space environment since March 8, 2007. This paper presents recent achievements of the IR-ECDTM including space test results.

  1. Emission inventory for fugitive emissions from fuel in Denmark

    DEFF Research Database (Denmark)

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

    This report presents the methodology and data used in the Danish inventory of fugitive emissions from fuels for the years until 2013. The inventory of fugitive emissions includes CO2, CH4, N2O, SO2, NOx, NMVOC, CO, particulate matter, Black carbon, heavy metals, dioxin and PAHs. In 2013 the total...... Danish emission of greenhouse gasses was 54 584 Gg CO2 equivalents. Fugitive emissions from fuels account for 387 Gg CO2 equivalents or approximately 1 %. The major part of the fugitive emissions are emitted as CO2 (61 %) mainly from flaring in upstream oil and gas production. The major source...... of fugitive CH4 emission is production of oil and gas in the North Sea, refining of oil and loading of oil onto ships both offshore and onshore. The fugitive emissions of NMVOC originate for the major part from oil and gas production, loading of ships, transmission and distribution of oil, and to a less...

  2. Emission inventory for fugitive emissions from fuel in Denmark

    DEFF Research Database (Denmark)

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

    This report presents the methodology and data used in the Danish inventory of fugitive emissions from fuels for the years until 2013. The inventory of fugitive emissions includes CO2, CH4, N2O, SO2, NOx, NMVOC, CO, particulate matter, Black carbon, heavy metals, dioxin and PAHs. In 2013 the total...... Danish emission of greenhouse gasses was 54 584 Gg CO2 equivalents. Fugitive emissions from fuels account for 387 Gg CO2 equivalents or approximately 1 %. The major part of the fugitive emissions are emitted as CO2 (61 %) mainly from flaring in upstream oil and gas production. The major source...... of fugitive CH4 emission is production of oil and gas in the North Sea, refining of oil and loading of oil onto ships both offshore and onshore. The fugitive emissions of NMVOC originate for the major part from oil and gas production, loading of ships, transmission and distribution of oil, and to a less...

  3. Microwave Emission from Aligned Dust

    CERN Document Server

    Lazarian, A

    2003-01-01

    Polarized microwave emission from dust is an important foreground that may contaminate polarized CMB studies unless carefully accounted for. We discuss potential difficulties associated with this foreground, namely, the existence of different grain populations with very different emission/polarization properties and variations of the polarization yield with grain temperature. In particular, we discuss observational evidence in favor of rotational emission from tiny PAH particles with dipole moments, i.e. ``spinning dust'', and also consider magneto-dipole emission from strongly magnetized grains. We argue that in terms of polarization, the magneto-dipole emission may dominate even if its contribution to total emissivity is subdominant. Addressing polarized emission at frequencies larger than approsimately 100 GHz, we discuss the complications arising from the existence of dust components with different temperatures and possibly different alignment properties.

  4. Danish emission inventories for agriculture

    DEFF Research Database (Denmark)

    Mikkelsen, Mette Hjorth; Albrektsen, Rikke; Gyldenkærne, Steen

    compounds (NMVOC) and other pollutants related to the field burning of agricultural residue such as NOx, CO2, CO, SO2, heavy metals, dioxin and PAH. The ammonia emission from 1985 to 2009 has decreased from 119 300 tonnes of NH3 to 73 800 tonnes NH3, corresponding to a 38 % reduction. The emission...... emissions calculations and data management an Integrated Database model for Agricultural emissions (IDA) is used. The emission from the agricultural sector includes emission of the greenhouse gases methane (CH4), nitrous oxide (N2O), ammonia (NH3), particulate matter (PM), non-methane volatile organic...... of greenhouse gases has decreased by 25 % from 12.9 M tonnes CO2 equivalents to 9.6 M tonnes CO2 equivalents from 1985 to 2009. Improvements in feed efficiency and utilisation of nitrogen in livestock manure are the most important reasons for the reduction of both the ammonia and greenhouse gas emissions...

  5. Improving Emission Estimates With The Community Emissions Data System (CEDS

    Science.gov (United States)

    Smith, S.; Hoesly, R. M.

    2016-12-01

    Inventory data is a key component of scientific and regulatory efforts focused on air pollution, climate and global change and also a critical compliment for observational emission efforts. The Community Emissions Data System (CEDS) project aims to provide consistent estimates of historical anthropogenic emissions using an open-source data system. The first product from this system was anthropogenic emissions over 1750-2014 of reactive gases, aerosols, and carbon dioxide, for use in CMIP6. These data are annually resolved, have monthly seasonality, were estimated at a moderately detailed level of 50+ sectors and 8 fuel types, and were mapped to spatial grids. CEDS combines bottom-up default emissions estimates that are calibrated to country-level inventories where these are deemed reliable. Outside of years where inventories are available, driver data and emission factors are extended using user-defined rules. The system is designed to facilitate annual updates (so the most recent inventory data is available). The software and most input data are being released as open source software in order to provide access to assumptions, improve emission estimates, and allow access to fundamental emissions data for research purposes. We report on our efforts to expand the spatial resolution by estimating emission trends by state/province for large countries. This will allow spatial shifts in emissions over time to be better represented and make the data more useful for research such as that discussed in this session. As part of these improvements we will add support for use of regionally-specific emission proxies and point sources. A key focus of ongoing research is better quantification of emissions uncertainty. Our goal is consistent estimation of uncertainty over time, sector, and country. We will also report on results estimating the additional uncertainty associated with extending emissions data over recent years. http://www.globalchange.umd.edu/CEDS/

  6. Positron Emission Tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

  7. Positron emission tomography

    CERN Document Server

    Paans, A M J

    2006-01-01

    Positron Emission Tomography (PET) is a method for measuring biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labelled with positron emitting radionuclides such as 11C, 13N, 15O and 18F and by measuring the annihilation radiation using a coincidence technique. This includes also the measurement of the pharmacokinetics of labelled drugs and the measurement of the effects of drugs on metabolism. Also deviations of normal metabolism can be measured and insight into biological processes responsible for diseases can be obtained. At present the combined PET/CT scanner is the most frequently used scanner for whole-body scanning in the field of oncology.

  8. Emission rate measuring device

    Science.gov (United States)

    Luckat, S.

    1980-09-01

    The development and application of an emission rate measuring device for gaseous components is explored. The device contains absorption fluid from a supply container that moistens a cylindrical paper sleeve. A newer model is provided with a direct current motor requiring less electricity than an older model. The hose pump is modified to avoid changing it and the filter sleeve is fastened more securely to the distributor head. Application of the measuring devices is discussed, particularly at the Cologne Cathedral, where damage to the stone is observed.

  9. Positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-07

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

  10. Positron Emission Tomography (PET)

    Science.gov (United States)

    Welch, M. J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

  11. Spinning dust emission from ultrasmall silicates: emissivity and polarization spectrum

    CERN Document Server

    Hoang, Thiem; Lan, Nguyen Quynh

    2016-01-01

    Anomalous microwave emission (AME) is an important Galactic foreground of Cosmic Microwave Background (CMB) radiation. It is believed that the AME arises from rotational emission by spinning polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium (ISM). In this paper, we assume that a population of ultrasmall silicate grains may exist in the ISM, and quantify rotational emissivity from these tiny particles and its polarization spectrum. We found that spinning silicate nanoparticles can produce strong rotational emission when those small grains follow a log-normal size distribution. The polarization fraction of spinning dust emission from tiny silicates increases with decreasing the dipole moment per atom ($\\beta$) and can reach $P\\sim 20\\%$ for $\\beta\\sim 0.1$D at grain temperature of 60 K. We identify a parameter space $(\\beta,Y_{Si})$ for silicate nanoparticles in which its rotational emission can adequately reproduce both the observed AME and the polarization of the AME, without violating the ob...

  12. GHG emissions due to deforestation

    Energy Technology Data Exchange (ETDEWEB)

    Croezen, H.; Van Valkengoed, M.

    2009-05-15

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

  13. Elastic emission polishing

    Energy Technology Data Exchange (ETDEWEB)

    Loewenthal, M.; Loseke, K.; Dow, T.A.; Scattergood, R.O.

    1988-12-01

    Elastic emission polishing, also called elastic emission machining (EEM), is a process where a stream of abrasive slurry is used to remove material from a substrate and produce damage free surfaces with controlled surface form. It is a noncontacting method utilizing a thick elasto-hydrodynamic film formed between a soft rotating ball and the workpiece to control the flow of the abrasive. An apparatus was built in the Center, which consists of a stationary spindle, a two-axis table for the workpiece, and a pump to circulate the working fluid. The process is controlled by a programmable computer numerical controller (CNC), which presently can operate the spindle speed and movement of the workpiece in one axis only. This apparatus has been used to determine material removal rates on different material samples as a function of time, utilizing zirconium oxide (ZrO{sub 2}) particles suspended in distilled water as the working fluid. By continuing a study of removal rates the process should become predictable, and thus create a new, effective, yet simple tool for ultra-precision mechanical machining of surfaces.

  14. Ammonia emissions from seabird colonies

    Science.gov (United States)

    Blackall, Trevor D.; Wilson, Linda J.; Theobald, Mark R.; Milford, Celia; Nemitz, Eiko; Bull, Jennifer; Bacon, Philip J.; Hamer, Keith C.; Wanless, Sarah; Sutton, Mark A.

    2007-05-01

    Ammonia emissions were measured from two entire seabird colonies with contrasting species assemblages, to ascertain the ammonia volatilisation potentials among seabird species in relation to their nesting behaviour. Emissions were calculated from downwind plume measurements of ammonia concentration using both inverse dispersion and tracer ratio methods. Measured colony emissions ranged 1-90 kg NH3 hour-1, and equated to 16 and 36% volatilization of excreted nitrogen for colonies dominated by ground/burrow nesting and bare rock nesting birds, respectively. The results were applied in a bioenergetics model with a global seabird database. Seabird colonies are found to represent the largest point sources of ammonia globally (up to ~6 Gg NH3 colony-1 year-1). Moreover the largest emissions occur mainly in remote environments with otherwise low NH3 emissions. These ammonia ``hot spots'' explain significant perturbations of the nitrogen cycle in these regions and add ~20% to oceanic ammonia emissions south of latitude 45°S.

  15. Extragalactic diffuse (C II) emission

    Science.gov (United States)

    Madden, Suzanne C.; Geis, Norbert; Townes, Charles H.; Genzel, R.; Herrmann, F.; Poglitsch, Albrecht; Stacey, G. J.

    1995-01-01

    The 158 micro m (CII) line has been mapped in the galaxies Centaurus A, M83, NGC 6946, and NGC 891. The emission exists over very large scales, peaking in the nuclei and extending beyond the spiral arms and molecular disks. While most of the (CII) emission from the nuclei and spiral arms originates in photodissociated gas, the diffuse atomic gas can account for much of the (CII) emission in the extended regions.

  16. Greenhouse Gas Emissions: Quantifying Methane Emissions from Livestock

    Directory of Open Access Journals (Sweden)

    Rafiu O. Yusuf

    2012-01-01

    Full Text Available Problem statement: The rearing of animals for domestic consumption and export invariably lead to the production of methane as a product of digestion. This study investigated the emission of methane from Malaysian livestock between 1980 and 2008. Approach: Seven categories of animals identified were camel, buffalo, sheep, goats, horse, pigs and poultry. The estimation of methane was based on the IPCC Tier 1 and Tier 2 methods. Methane emission from cattle rose by 44% within the period from 45.61-65.57 Gg. Results: Buffalo recorded a drop in methane emission by 54% from 17.12-7.86 Gg while the methane emission from sheep initially rose by 350% in 1992 only to drop by another 56% by 2008. Goats emission only declined by 17% from 1.79 Gg in 1980-1.49 Gg by 2008. Methane emission from horse has been consistent at around 0.14 Gg. The decreasing stock of pigs has led to a drop in methane emission from these set of animals with most of the emission coming from manure management. Conclusion: The healthy export market for poultry has seen a rise in methane emission by 274% from 2.18 Gg in 1980-8.17 Gg by 2008. The overall increase in methane emission from all the livestock is 20% from 81.83 Gg in 1980-98.76 Gg in 2008. With the aggressive drive of government to boost cattle and goat production, there is the likelihood of an increase in methane emission in the future and mitigation options will have to be applied.

  17. OPIC Greenhouse Gas Emissions Inventory

    Data.gov (United States)

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

  18. The Emissions Gap Report 2014

    DEFF Research Database (Denmark)

    Farrell, Timothy Clifford

    This fifth Emissions Gap report has a different focus from previous years. While it updates the 2020 emissions gap analysis, it gives particular attention to the implications of the global carbon dioxide emissions budget for staying within the 2 °C limit beyond 2020. It does so because countries...... are giving increasing attention to where they need to be in 2025, 2030 and beyond. Furthermore, this year’s update of the report benefits from the findings on the emissions budget from the latest series of Intergovernmental Panel on Climate Change (IPCC) reports...

  19. [Spectral emissivity of thin films].

    Science.gov (United States)

    Zhong, D

    2001-02-01

    In this paper, the contribution of multiple reflections in thin film to the spectral emissivity of thin films of low absorption is discussed. The expression of emissivity of thin films derived here is related to the thin film thickness d and the optical constants n(lambda) and k(lambda). It is shown that in the special case d-->infinity the emissivity of thin films is equivalent to that of the bulk material. Realistic numerical and more precise general numerical results for the dependence of the emissivity on d, n(lambda) and k(lambda) are given.

  20. Positron emission mammography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.

    2003-10-02

    This paper examines current trends in Positron Emission Mammography (PEM) instrumentation and the performance tradeoffs inherent in them. The most common geometry is a pair of parallel planes of detector modules. They subtend a larger solid angle around the breast than conventional PET cameras, and so have both higher efficiency and lower cost. Extensions to this geometry include encircling the breast, measuring the depth of interaction (DOI), and dual-modality imaging (PEM and x-ray mammography, as well as PEM and x-ray guided biopsy). The ultimate utility of PEM may not be decided by instrument performance, but by biological and medical factors, such as the patient to patient variation in radiotracer uptake or the as yet undetermined role of PEM in breast cancer diagnosis and treatment.

  1. Electron Cyclotron Emission Radiometer

    Science.gov (United States)

    Morales, Cristina

    2009-11-01

    There is much interest in studying plasmas that generate hot electrons. The goal of this project is to develop a wide band electron cyclotron radiometer to measure the non-Maxwellian rapid rises in electron temperature. These rapid increases in temperature will then be correlated to instabilities in the plasma. This project explores a type of noncontact temperature measurement. We will attempt to show the feasibility of electron cyclotron emissions to measure the Maryland Centrifugal Experiment's electron plasma temperature. The radiometer has been designed to have 100dB of gain and a sensitivity of 24mV/dB given by its logarithmic amplifier. If successful, this radiometer will be used as a diagnostic tool in later projects such as the proposed experiment studying magnetic reconnection using solar flux loops.

  2. Transportation Emissions: some basics

    DEFF Research Database (Denmark)

    Kontovas, Christos A.; Psaraftis, Harilaos N.

    2016-01-01

    Transportation is the backbone of international trade and a key engine driving globalization. However, there is growing concern that the Earth’s atmospheric composition is being altered by human activities, including transportation, which can lead to climate change. Air pollution from...... transportation and especially carbon dioxide emissions are at the center stage of discussion by the world community through various international treaties, such as the Kyoto Protocol. The transportation sector also emits non-CO2 pollutants that have important effects on air quality, climate, and public health...... and its contribution to climate change. In addition, this chapter presents the basics of environmental policy measures. In that context, we describe a way to measure the cost-effectiveness of various measures through the so-called Marginal Abatement Cost (MAC). Finally, the chapter deals with the topic...

  3. Emissivity independent optical pyrometer

    Science.gov (United States)

    Earl, Dennis Duncan; Kisner, Roger A.

    2017-04-04

    Disclosed herein are representative embodiments of methods, apparatus, and systems for determining the temperature of an object using an optical pyrometer. Certain embodiments of the disclosed technology allow for making optical temperature measurements that are independent of the surface emissivity of the object being sensed. In one of the exemplary embodiments disclosed herein, a plurality of spectral radiance measurements at a plurality of wavelengths is received from a surface of an object being measured. The plurality of the spectral radiance measurements is fit to a scaled version of a black body curve, the fitting comprising determining a temperature of the scaled version of the black body curve. The temperature is then output. The present disclosure is not to be construed as limiting and is instead directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone or in various combinations and subcombinations with one another.

  4. Emissivity independent optical pyrometer

    Energy Technology Data Exchange (ETDEWEB)

    Earl, Dennis Duncan; Kisner, Roger A.

    2017-04-04

    Disclosed herein are representative embodiments of methods, apparatus, and systems for determining the temperature of an object using an optical pyrometer. Certain embodiments of the disclosed technology allow for making optical temperature measurements that are independent of the surface emissivity of the object being sensed. In one of the exemplary embodiments disclosed herein, a plurality of spectral radiance measurements at a plurality of wavelengths is received from a surface of an object being measured. The plurality of the spectral radiance measurements is fit to a scaled version of a black body curve, the fitting comprising determining a temperature of the scaled version of the black body curve. The temperature is then output. The present disclosure is not to be construed as limiting and is instead directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone or in various combinations and subcombinations with one another.

  5. Positron Emission Mammography imaging

    Science.gov (United States)

    Moses, William W.

    2004-06-01

    This paper examines current trends in Positron Emission Mammography (PEM) instrumentation and the performance tradeoffs inherent in them. The most common geometry is a pair of parallel planes of detector modules. They subtend a larger solid angle around the breast than conventional PET cameras, and so have both higher efficiency and lower cost. Extensions to this geometry include encircling the breast, measuring the depth of interaction (DOI), and dual-modality imaging (PEM and X-ray mammography, as well as PEM and X-ray guided biopsy). The ultimate utility of PEM may not be decided by instrument performance, but by biological and medical factors, such as the patient to patient variation in radiotracer uptake or the as yet undetermined role of PEM in breast cancer diagnosis and treatment.

  6. Estimation of broadband surface emissivity from narrowband emissivities.

    Science.gov (United States)

    Tang, Bo-Hui; Wu, Hua; Li, Chuanrong; Li, Zhao-Liang

    2011-01-01

    This work analyzed and addressed the estimate of the broadband emissivities for the spectral domains 3-14μm (ε(3-14)) and 3-∞μm (ε(3-∞). Two linear narrow-to-broadband conversion models were proposed to estimate broadband emissivities ε(3-14) and ε(3-∞) using the Moderate Resolution Imaging Spectroradiometer (MODIS) derived emissivities in three thermal infrared channels 29 (8.4-8.7μm), 31 (10.78-11.28μm) and 32 (11.77-12.27μm). Two independent spectral libraries, the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) spectral library and the MODIS UCSB (University of California, Santa Barbara) emissivity library, were used to calibrate and validate the proposed models. Comparisons of the estimated broadband emissivities using the proposed models and the calculated values from the spectral libraries, showed that the proposed method of estimation of broadband emissivity has potential accuracy and the Root Mean Square Error (RMSE) between estimated and calculated broadband emissivities is less than 0.01 for both ε(3-14) and ε(3-∞).

  7. Emissivity measurement of high-emissivity black paint at CENAM

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas G, D., E-mail: dcardena@cenam.mx [Centro Nacional de Metrologia, Km 4.5 Carretera a los Cues, El Marques, 76246 Santiago de Queretaro, Queretaro (Mexico)

    2014-07-01

    To measure the temperature of the surface of an opaque object by radiation thermometry, it is necessary to know its surface emissivity. High emissivity black paint can be applied to the inner walls of a cavity to be used as a blackbody radiator. It can also be applied to some highly reflecting metals so that their temperature can be estimated by radiation thermometry. In this work, it is described the emissivity measurement of high-emissivity black paint that has been used for the two applications described above. The average emissivity of the measured paint in the 8 to 14 micrometers wavelength range was estimated as 0.972 ± 0.012. The results obtained may be of use for those using the paint at temperatures from 50 to 150 grades C. (Author)

  8. Neutrino emission in neutron stars

    NARCIS (Netherlands)

    van Dalen, ENE; Dieperink, AEL; Tjon, JA

    Neutrino emissivities in a neutron star are computed for the neutrino bremsstrahlung process. In the first part, the electroweak nucleon-nucleon bremsstrahlung is calculated in free space in terms of an on-shell T matrix using a generalized low-energy theorem. In the second part, the emissivities

  9. Emission of formaldehyde from furniture

    DEFF Research Database (Denmark)

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

    The emission of formaldehyde from 20 pieces of furniture, representing a variety of types, was measured in climate chambers. Most tests show low emissions but certain scenarios of furnishing, including furniture with large surface areas in relation to room volume can emit formaldehyde resulting...

  10. DOES ELECTRIC CAR PRODUCE EMISSIONS?

    Directory of Open Access Journals (Sweden)

    Vladimír RIEVAJ

    2017-03-01

    Full Text Available This article focuses on the comparison of the amount of emissions produced by vehicles with a combustion engine and electric cars. The comparison, which is based on the LCA factor results, indicates that an electric car produces more emissions than a vehicle with combustion engine. The implementation of electric cars will lead to an increase in the production of greenhouse gases.

  11. Deliberating emission reduction options

    Energy Technology Data Exchange (ETDEWEB)

    Dowd, A.M.; Rodriguez, M.; Jeanneret, T. [Commonwealth Scientific and Industrial Research Organisation CSIRO, 37 Graham Rd, Highett VIC 3190 (Australia); De Best-Waldhober, M.; Straver, K.; Mastop, J.; Paukovic, M. [Energy research Centre of the Netherlands ECN, Policy Studies, Amsterdam (Netherlands)

    2012-06-15

    For more than 20 years there has been a concerted international effort toward addressing climate change. International conventions, such as the United Nations Foreign Convention on Climate Change (UNFCCC; ratified in 1994), have been established by committed nations seeking to address global climate change through the reduction of greenhouse gases emitted into the Earth's atmosphere (Global CCS Institute, 2011). Long recognised as the most crucial of the greenhouse gases to impact global warming, the majority of carbon dioxide's anthropogenic global emissions are directly related to fuel combustion of which both Australia and the Netherlands' energy production is significantly reliant. Both these nations will need to consider many opinions and make hard decisions if alternative energy options are to be implemented at the scale that is required to meet international emission targets. The decisions that are required not only need to consider the many options available but also their consequences. Along with politicians, policy developers and industry, the general public also need to be active participants in deciding which energy options, and their subsequent consequences, are acceptable for implementation at the national level. Access to balanced and factual information is essential in establishing informed opinions on the many policy options available. Past research has used several methods to measure public perceptions and opinions yet for complex issues, such as emission reduction, some of these methods have shown to be problematic. For example, semi structured interviews can provide data that is flexible and context rich yet is does also come with the limitations such as it seldom provides a practical assessment that can be utilised from researcher to researcher, across disciplines and public participation techniques. Surveys on the other hand usually address these limitations but surveys that do not encourage comparison of information or ask

  12. Emission of formaldehyde from furniture

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  13. Nanoparticle emissions from combustion engines

    CERN Document Server

    Merkisz, Jerzy

    2015-01-01

     This book focuses on particulate matter emissions produced by vehicles with combustion engines. It describes the physicochemical properties of the particulate matter, the mechanisms of its formation and its environmental impacts (including those on human beings). It discusses methods for measuring particulate mass and number, including the state-of-the-art in Portable Emission Measurement System (PEMS) equipment for measuring the exhaust emissions of both light and heavy-duty vehicles and buses under actual operating conditions. The book presents the authors’ latest investigations into the relations between particulate emission (mass and number) and engine operating parameters, as well as their new findings obtained through road tests performed on various types of vehicles, including those using diesel particulate filter regeneration. The book, which addresses the needs of academics and professionals alike, also discusses relevant European regulations on particulate emissions and highlights selected metho...

  14. Low Temperature Emissivity Measurement System

    Directory of Open Access Journals (Sweden)

    Jignesh A. Patel

    2014-05-01

    Full Text Available The emissivity of a material is the relative ability of its surface to emit energy by radiation. It is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. Knowledge about the low temperature emissivity of materials and coatings can be essential to the design of fusion cryoplants and in the thermal modeling for space satellite missions. The emittance of materials at cryogenics temperatures often cannot be predicted from room temperature data, but for computing radiative loads and infrared backgrounds this cryogenic data is often required. Measurement of the cryogenic emissivity of a highly reflective surface is a significant challenge: little thermal power is radiated from the sample, and the background radiation. However some researchers have measured emissivity at various low temperature ranges. Present work reports, the various emissivity measurement setup and their considerations.

  15. The Venus Emissivity Mapper

    Science.gov (United States)

    Helbert, Joern; Marcq, Emmanuel; Widemann, Thomas; Mueller, Nils; Kappel, David; Tsang, Constantine; Maturilli, Alessandro; Ferrari, Sabrina; D'Amore, Mario; Dyar, Melinda; Smrekar, Suzanne

    2016-10-01

    The permanent cloud cover of Venus prohibits observations of the surface with traditional imaging techniques over the entire visible spectral range. Fortunately, Venus' atmospheric gases are largely transparent in narrow spectral windows near 1 mm. Ground observers were the first to successfully use these windows, followed by spacecraft observations during the flyby of the Galileo mission on its way to Jupiter and most recently from Venus orbit by ESA's Venus Express with the VMC and VIRTIS instruments. Analyses of VIRTIS measurements have successfully demonstrated that surface information can be extracted from these windows, but the design of the instrument limited its use for more in-depth surface investigations.Based on experience gained from using VIRTIS to observe the surface of Venus and new high temperature laboratory experiments currently performed at the Planetary Spectroscopy Laboratory of DLR, we have designed the multi-spectral Venus Emissivity Mapper (VEM). Observations from VIRTIS have revealed surface emissivity variations correlated with geological features, but existing data sets contain only three spectral channels. VEM is optimized to map the surface composition and texture, and to search for active volcanism using the narrow atmospheric windows, building on lessons from prior instrumentation and methodology. It offers an opportunity to gain important information about surface mineralogy and texture by virtue of having six different channels for surface mapping.VEM is focused mainly on observing the surface, mapping in all near-IR atmospheric windows using filters with spectral characteristics optimized for the wavelengths and widths of those windows. It also observes bands necessary for correcting atmospheric effects; these bands also provide valuable scientific data on composition as well as altitude and size distribution of the cloud particles, and on H2O vapor abundance variations in the lowest 15 km of the atmosphere.In combination with a

  16. Photophysics of fullerenes: Thermionic emission

    Energy Technology Data Exchange (ETDEWEB)

    Compton, R.N. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States); Tuinman, A.A. [Univ. of Tennessee, Knoxville, TN (United States); Huang, J. [Ames Lab., IA (United States)

    1996-09-01

    Multiphoton ionization of fullerenes using long-pulse length lasers occurs mainly through vibrational autoionization. In many cases the laser ionization can be described as thermionic in analogy to the boiling off of electrons from a filament. Thermionic emission manifests itself as a delayed emission of electrons following pulsed laser excitation. Klots has employed quasiequilibrium theory to calculate rate constants for thermionic emission from fullerenes which seem to quantitatively account for the observed delayed emission times and the measured electron energy distributions. The theory of Klots also accounts for the thermionic emission of C{sub 60} excited by a low power CW Argon Ion laser. Recently Klots and Compton have reviewed the evidence for thermionic emission from small aggregates where mention was also made of experiments designed to determine the effects of externally applied electric fields on thermionic emission rates. The authors have measured the fullerene ion intensity as a function of the applied electric field and normalized this signal to that produced by single photon ionization of an atom in order to correct for all collection efficiency artifacts. The increase in fullerene ion signal relative to that of Cs{sup +} is attributed to field enhanced thermionic emission. From the slope of the Schottky plot they obtain a temperature of approximately 1,000 K. This temperature is comparable to but smaller than that estimated from measurements of the electron kinetic energies. This result for field enhanced thermionic emission is discussed further by Klots and Compton. Thermionic emission from neutral clusters has long been known for autodetachment from highly excited negative ions. Similarly, electron attachment to C{sub 60} in the energy range from 8 to 12 eV results in C{sub 60} anions with lifetimes in the range of microseconds. Quasiequilibrium theory (QET) calculations are in reasonable accord with these measurements.

  17. Pricing hazardous substance emissions

    Energy Technology Data Exchange (ETDEWEB)

    Staring, Knut; Vennemo, Haakon

    1997-12-31

    This report discusses pricing of emissions to air of several harmful substances. It combines ranking indices for environmentally harmful substances with economic valuation data to yield price estimates. The ranking methods are discussed and a relative index established. Given the relative ranking of the substances, they all become valued by assigning a value to one of them, the `anchor` substance, for which lead is selected. Valuations are provided for 19 hazardous substances that are often subject to environmental regulations. They include dioxins, TBT, etc. The study concludes with a discussion of other categories of substances as well as uncertainties and possible refinements. When the valuations are related to CO, NOx, SOx and PM 10, the index system undervalues these pollutants as compared to other studies. The scope is limited to the outdoor environment and does not include global warming and eutrophication. The indices are based on toxicity and so do not apply to CO{sub 2} or other substances that are biologically harmless. The index values are not necessarily valid for all countries and should be considered as preliminary. 18 refs., 6 tabs.

  18. Monoterpene emission from ponderosa pine

    Science.gov (United States)

    Lerdau, Manual; Dilts, Stephen B.; Westberg, Hal; Lamb, Brian K.; Allwine, Eugene J.

    1994-01-01

    We explore the variability in monoterpene emissions from ponderosa pine beyond that which can be explained by temperature alone. Specifically, we examine the roles that photosynthesis and needle monoterpene concentrations play in controlling emissions. We measure monoterpene concentrations and emissions, photosynthesis, temperature, and light availability in the late spring and late summer in a ponderosa pine forest in central Oregon. We use a combination of measurements from cuvettes and Teflon bag enclosures to show that photosynthesis is not correlated with emissions in the short term. We also show that needle monoterpene concentrations are highly correlated with emissions for two compounds, alpha-pinene and beta-pinene, but that Delta-carene concentrations are not correlated with emissions. We suggest that direct effects of light and photosynthesis do not need to be included in emission algorithms. Our results indicate that the role of needle concentration bears further investigation; our results for alpha-pinene and beta-pinene are explainable by a Raoult's law relationship, but we cannot yet explain the cause of our results with Delta-carene.

  19. Advanced Collaborative Emissions Study (ACES)

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Daniel; Costantini, Maria; Van Erp, Annemoon; Shaikh, Rashid; Bailey, Brent; Tennant, Chris; Khalek, Imad; Mauderly, Joe; McDonald, Jacob; Zielinska, Barbara; Bemis, Jeffrey; Storey, John; Hallberg, Lance; Clark, Nigel

    2013-12-31

    The objective of the Advanced Collaborative Emissions Study (ACES) was to determine before widespread commercial deployment whether or not the new, energy-efficient, heavy duty diesel engines (2007 and 2010 EPA Emissions Standards Compliant) may generate anticipated toxic emissions that could adversely affect the environment and human health. ACES was planned to take place in three phases. In Phase 1, extensive emissions characterization of four production-intent prototype engine and control systems designed to meet 2007 standards for nitrogen oxides (NOx) and particulate matter (PM) was conducted at an existing emissions characterization facility: Southwest Research Institute (SwRI). One of the tested engines was selected (at random, after careful comparison of results) for health testing in Phase 3. In Phase 2, extensive emission characterization of three production-intent prototype engine and control systems meeting the 2010 standards (including more advanced NOx controls to meet the more stringent 2010 NOx standards) was conducted at the same test facility. In Phase 3, one engine/aftertreatment system selected from Phase 1 was further characterized during health effects studies (at an existing inhalation toxicology laboratory: Lovelace Respiratory Research Institute, [LRRI]) to form the basis of the ACES safety assessment. The Department of Energy (DOE) award provided funding for emissions characterization in Phases 1 and 2 as well as exposure characterization in Phase 3. The main health analyses in Phase 3 were funded separately and are not reported here.

  20. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  1. Radio emission in Mercury magnetosphere

    Science.gov (United States)

    Varela, J.; Reville, V.; Brun, A. S.; Pantellini, F.; Zarka, P.

    2016-10-01

    Context. Active stars possess magnetized wind that has a direct impact on planets that can lead to radio emission. Mercury is a good test case to study the effect of the solar wind and interplanetary magnetic field (IMF) on radio emission driven in the planet magnetosphere. Such studies could be used as proxies to characterize the magnetic field topology and intensity of exoplanets. Aims: The aim of this study is to quantify the radio emission in the Hermean magnetosphere. Methods: We use the magnetohydrodynamic code PLUTO in spherical coordinates with an axisymmetric multipolar expansion for the Hermean magnetic field, to analyze the effect of the IMF orientation and intensity, as well as the hydrodynamic parameters of the solar wind (velocity, density and temperature), on the net power dissipated on the Hermean day and night side. We apply the formalism derived by Zarka et al. (2001, Astrophys. Space Sci., 277, 293), Zarka (2007, Planet. Space Sci., 55, 598) to infer the radio emission level from the net dissipated power. We perform a set of simulations with different hydrodynamic parameters of the solar wind, IMF orientations and intensities, that allow us to calculate the dissipated power distribution and infer the existence of radio emission hot spots on the planet day side, and to calculate the integrated radio emission of the Hermean magnetosphere. Results: The obtained radio emission distribution of dissipated power is determined by the IMF orientation (associated with the reconnection regions in the magnetosphere), although the radio emission strength is dependent on the IMF intensity and solar wind hydro parameters. The calculated total radio emission level is in agreement with the one estimated in Zarka et al. (2001, Astrophys. Space Sci., 277, 293) , between 5 × 105 and 2 × 106 W.

  2. [Tau Positron Emission Tomography].

    Science.gov (United States)

    Higuchi, Makoto

    2017-07-01

    Accumulation of fibrillar tau protein aggregates is a neuropathological hallmark of Alzheimer's disease (AD) and related neurodegenerative dementias, including a subgroup of frontotemporal lobar degeneration (FTLD). Visualization of tau lesions in the brains of living subjects enables a pathology-based diagnosis of dementing illnesses in the prodromal stage, and offers objective measures of disease progression and outcomes of disease-modifying therapies. With this rationale, diverse classes of low-molecular-weight chemicals capable of binding to a β-pleated sheet structure have been developed to be used for in vivo positron emission tomography (PET) of tau pathologies. Clinical PET studies of AD patients with such tau probes have provided the following insights: (1) Tau fibrils accumulate in the hippocampal formation in an age-dependent manner that is independent of amyloid-beta peptide (Aβ) pathology; (2) The deposition of Aβ may trigger a spatial expansion of tau pathology, in transition from normal aging to advanced AD; and (3) Tau accumulation is intimately associated with local neuronal loss, leading to cortical atrophy and focal symptoms. In contrast, studies of FTLD have shown a limited performance of first-generation PET probes in capturing non-AD-type tau lesions. New compounds have accordingly been developed and clinically tested, proving to yield a high contrast for tau deposits with high specificity. These second-generation probes are being evaluated primarily by pharmaceutical companies, in line with their growing demands for neuroimaging-based biomarkers serving for clinical trials of anti-Aβ and anti-tau therapies. Meanwhile, a consortium flexibly linking academia and industry to facilitate the utilization of research tools, including tau PET probes, has been established in Japan, for the ultimate purpose of elucidating the molecular etiology of tauopathies and creating diagnostic and therapeutic agents based on such an understanding.

  3. Infrared emission from interstellar PAHs

    Science.gov (United States)

    Allamandola, L. J.; Tielens, A. G. G. M.; Barker, J. R.

    1987-01-01

    The mid-IR absorption and Raman spectra of polycyclic aromatic hydrocarbons (PAHs) and the mechanisms determining them are reviewed, and the implications for observations of similar emission spectra in interstellar clouds are considered. Topics addressed include the relationship between PAHs and amorphous C, the vibrational spectroscopy of PAHs, the molecular emission process, molecular anharmonicity, and the vibrational quasi-continuum. Extensive graphs, diagrams, and sample spectra are provided, and the interstellar emission bands are attributed to PAHs with 20-30 C atoms on the basis of the observed 3.3/3.4-micron intensity ratios.

  4. Reducing ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2011-01-01

    The NEC directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the largest reductions since 1990...... to the high expectations at the outset. Despite this, the paper concludes that Denmark is likely to reduce emission by 50% from 1990 to 2020 and reach the likely 2020 NEC ceiling....

  5. Livestock and greenhouse gas emissions

    DEFF Research Database (Denmark)

    Herrero, M; Gerber, P; Vellinga, T

    2011-01-01

    Estimates of global greenhouse gases (GHG) emissions attributable to livestock range from 8 to 51%. This variability creates confusion among policy makers and the public as it suggests that there is a lack of consensus among scientists with regard to the contribution of livestock to global GHG...... fixed fossil C through combustion. These deviances from internationally accepted protocols create confusion and direct attention from anthropomorphic practices which have the most important contribution to global GHG emissions. Global estimates of livestock GHG emissions are most reliable when...

  6. Greenhouse Gas Emissions: Quantifying Methane Emissions from Livestock

    OpenAIRE

    2012-01-01

    Problem statement: The rearing of animals for domestic consumption and export invariably lead to the production of methane as a product of digestion. This study investigated the emission of methane from Malaysian livestock between 1980 and 2008. Approach: Seven categories of animals identified were camel, buffalo, sheep, goats, horse, pigs and poultry. The estimation of methane was based on the IPCC Tier 1 and Tier 2 methods. Methane emission from cattle rose by 44% within the period from 45....

  7. Zero emission city. Preliminary study; Null-Emissions-Stadt. Sondierungsstudie

    Energy Technology Data Exchange (ETDEWEB)

    Diefenbach, N.; Enseling, A.; Werner, P.; Flade, A.; Greiff, R.; Hennings, D.; Muehlich, E.; Wullkopf, U.; Sturm, P.; Kieslich, W.; Born, R.; Grossklos, M.; Hatteh, R.; Mueller, K.; Ratschow, A.; Valouch-Fornoff, C.

    2002-10-01

    The idea of a 'zero emission city' is investigated by the Institut Wohnen und Umwelt on behalf of the Federal Minister of Education and Research. After describing the current situation and defining the key parameters of a 'zero emission city', settlement structures, power supply, production processes and transportation are analyzed and linked with the communal action level to obtain a framework for research, activities and actions. The study ends with recommendations for a research programme 'zero emission city'. (orig.) [German] Die von den Staedten der Industrielaender ausgehenden Emissionen stellen im Hinblick auf die globalen Belastungen wie z.B. Treibhauseffekt, Ozonabbau und Versauerung das Hauptproblem dar. Aus diesem Grunde bietet es sich an, den Gedanken der 'Null-Emissions-Stadt', der Vision einer moeglichst emissionsfreien Stadt, aufzugreifen und auf seine Tragfaehigkeit fuer innovative Handlungsmodelle forschungsstrategisch zu ueberpruefen. Das Bundesministerium fuer Bildung und Forschung hat das Institut Wohnen und Umwelt beauftragt, in einer Sondierungsstudie dieser Fragestellung nachzugehen. Nach der Festlegung der Ausgangsbedingungen und Eckpunkte der Vision 'Null-Emissions-Stadt' und der Analyse der vier Handlungsfelder Siedlungsstrukturen, Energieversorgung, Produktionsprozesse (Kreislaufwirtschaft) und Verkehr werden diese aufgegriffen und mit der kommunalen Handlungsebene verknuepft und zu einem Forschungs-, Handlungs- und moeglichen Aktionsrahmen zusammengefuegt. Die Studie schliesst mit Hinweisen fuer die Gestaltung eines Forschungsprogramms 'Null-Emissions-Stadt'. (orig.)

  8. Danish emission inventory for particular matter (PM)

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-11-01

    The first Danish emission inventory that was reported in 2002 was a provisional-estimate based on data presently available. This report documents methodology, emission factors and references used for an improved Danish emission inventory for particulate matter. Further results of the improved emission inventory for the year 2000 are shown. The particulate matter emission inventory includes TSP, PM,, and PM, The report covers emission inventories for transport and stationary combustion. An appendix covering emissions from agriculture is also included. For the transport sector, both exhaust and non-exhaust emission such as tyre and break wear and road abrasion are included. (au)

  9. Mercury Emissions: The Global Context

    Science.gov (United States)

    Mercury emissions are a global problem that knows no national or continental boundaries. Mercury that is emitted to the air can travel thousands of miles in the atmosphere before it is eventually deposited back to the earth.

  10. Dataset of NRDA emission data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Emissions data from open air oil burns. This dataset is associated with the following publication: Gullett, B., J. Aurell, A. Holder, B. Mitchell, D. Greenwell, M....

  11. Polarized Emission from Interstellar Dust

    CERN Document Server

    Vaillancourt, J E

    2006-01-01

    Observations of far-infrared (FIR) and submillimeter (SMM) polarized emission are used to study magnetic fields and dust grains in dense regions of the interstellar medium (ISM). These observations place constraints on models of molecular clouds, star-formation, grain alignment mechanisms, and grain size, shape, and composition. The FIR/SMM polarization is strongly dependent on wavelength. We have attributed this wavelength dependence to sampling different grain populations at different temperatures. To date, most observations of polarized emission have been in the densest regions of the ISM. Extending these observations to regions of the diffuse ISM, and to microwave frequencies, will provide additional tests of grain and alignment models. An understanding of polarized microwave emission from dust is key to an accurate measurement of the polarization of the cosmic microwave background. The microwave polarization spectrum will put limits on the contributions to polarized emission from spinning dust and vibrat...

  12. Coherent Radio Emission from Pulsars

    CERN Document Server

    Mitra, Dipanjan; Gil, Janusz

    2015-01-01

    We review a physical model where the high brightness temperature of 10$^{25}-10^{30}$ K observed in pulsar radio emission is explained by coherent curvature radiation excited in the relativistic electron-positron plasma in the pulsar magnetosphere.

  13. Emissivity measurements on aeronautical alloys

    Energy Technology Data Exchange (ETDEWEB)

    Campo, L. del, E-mail: leire.del-campo@cnrs-orleans.f [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Perez-Saez, R.B., E-mail: raul.perez@ehu.e [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain); Gonzalez-Fernandez, L. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Esquisabel, X.; Fernandez, I. [Industria de Turbo Propulsores, S.A., Planta de Zamudio, Edificio 300, 48170 Zamudio, Bizkaia (Spain); Gonzalez-Martin, P. [Industria de Turbo Propulsores, S.A., Parque empresarial San Fernando, Avda. Castilla 2, 28830 San Fernando de Henares, Madrid (Spain); Tello, M.J. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain)

    2010-01-21

    The emissivity of three Ni and Co based aeronautical alloys is analyzed in this paper. These alloys are employed in high temperature environments whenever good corrosion resistance, high temperature resistance and high strength are essential. Thus, apart from the aeronautical industry, these alloys are also used in other technological applications, as for example, aerospace, nuclear reactors, and tooling. The results in this paper extend the emissivity data for these alloys available in the literature. Emissivity dependence on the radiation wavelength (2-22 {mu}m), sample temperature (200-650 {sup o}C) and emission angle (0-85{sup o}) has been investigated. In addition, the effect of surface finish and oxidation has also been taken into consideration. The data in this paper have several applications, as temperature measurement of a target by pyrometry, low observability of airplanes and thermal radiation heat transfer simulation in airplane nozzles or furnaces.

  14. Advanced Emissions Control Development Program

    Energy Technology Data Exchange (ETDEWEB)

    A.P.Evans; K.E. Redinger; M.J. Holmes

    1998-04-01

    The objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. Ideally, the project aim is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPS), fabric filters (baghouse), and wet flue gas desulfurization. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate and hydrogen chloride. Following the construction and evaluation of a representative air toxics test facility in Phase I, Phase II focused on the evaluation of mercury and several other air toxics emissions. The AECDP is jointly funded by the United States Department of Energy's Federal Energy Technology Center (DOE), the Ohio Coal Development Office within the Ohio Department of Development (oCDO), and Babcock& Wilcox-a McDermott company (B&W).

  15. Controlling radiated emissions by design

    CERN Document Server

    Mardiguian, Michel

    2014-01-01

    The 3rd edition of Controlling Radiated Emissions by Design has been updated to reflect the latest changes in the field. New to this edition is material related to technical advances, specifically super-fast data rates on wire pairs, with no increase in RF interference. Throughout the book, details are given to control RF emissions using EMC design techniques. This book retains the step-by-step approach for incorporating EMC into every new design from the ground up. It describes the selection of quieter IC technologies, their implementation into a noise-free printed circuit layout, and the gathering of these into a low emissions package. Also included is how to design an I/O filter, along with connectors and cable considerations. All guidelines are supported throughout with comprehensive calculated examples. Design engineers, EMC specialists, and technicians will benefit from learning about the development of more efficient and economical control of emissions.

  16. Acoustic emission linear pulse holography

    Science.gov (United States)

    Collins, H.D.; Busse, L.J.; Lemon, D.K.

    1983-10-25

    This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.

  17. Energy and Emissions at EPA

    Science.gov (United States)

    To demonstrate its leadership in energy and environmental stewardship, EPA is committed to managing its own facilities and operations in a way that minimizes greenhouse gas (GHG) emissions and energy use.

  18. Turkey Run Landfill Emissions Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — landfill emissions measurements for the Turkey run landfill in Georgia. This dataset is associated with the following publication: De la Cruz, F., R. Green, G....

  19. SPECIFIC EMISSIONS FROM BIOMASS COMBUSTION

    Directory of Open Access Journals (Sweden)

    Pavel Skopec

    2014-02-01

    Full Text Available This paper deals with determining the specific emissions from the combustion of two kinds of biomass fuels in a small-scale boiler. The tested fuels were pellets made of wood and pellets made of rape plant straw. In order to evaluate the specific emissions, several combustion experiments were carried out using a commercial 25 kW pellet-fired boiler. The specific emissions of CO, SO2 and NOx were evaluated in relation to a unit of burned fuel, a unit of calorific value and a unit of produced heat. The specific emissions were compared with some data acquired from the reference literature, with relatively different results. The differences depend mainly on the procedure used for determining the values, and references provide no information about this. Although some of our experimental results may fit with one of the reference sources, they do not fit with the other. The reliability of the references is therefore disputable.

  20. Electrochromic Variable-Emissivity Surfaces

    Science.gov (United States)

    Rauh, R. David; Cogan, Stuart F.

    1988-01-01

    Temperature controlled by altering infrared radiative properties. Infrared emissivity of electrochromically active layer changed by applying voltage to insert or remove Li atoms electrochemically. Change reversible and continuously variable between specified limits of layered structure.

  1. Photon upconversion with directed emission

    Science.gov (United States)

    Börjesson, K.; Rudquist, P.; Gray, V.; Moth-Poulsen, K.

    2016-08-01

    Photon upconversion has the potential to increase the efficiency of single bandgap solar cells beyond the Shockley Queisser limit. Efficient light management is an important point in this context. Here we demonstrate that the direction of upconverted emission can be controlled in a reversible way, by embedding anthracene derivatives together with palladium porphyrin in a liquid crystalline matrix. The system is employed in a triplet-triplet annihilation photon upconversion scheme demonstrating controlled switching of directional anti Stokes emission. Using this approach an emission ratio of 0.37 between the axial and longitudinal emission directions and a directivity of 1.52 is achieved, reasonably close to the theoretical maximal value of 2 obtained from a perfectly oriented sample. The system can be switched for multiple cycles without any visible degradation and the speed of switching is only limited by the intrinsic rate of alignment of the liquid crystalline matrix.

  2. CONSTRAINING RADIO EMISSION FROM MAGNETARS

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, P.; Kaspi, V. M.; Dib, R. [Department of Physics, Rutherford Physics Building, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Champion, D. J. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Hessels, J. W. T., E-mail: plazar@physics.mcgill.ca [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands)

    2012-01-10

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U 0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected for any of our targets. The non-detections allow us to place luminosity upper limits of L{sub 1950} {approx}< 1.60 mJy kpc{sup 2} for periodic emission and L{sub 1950,single} {approx}< 7.6 Jy kpc{sup 2} for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.

  3. Constraining Radio Emission from Magnetars

    CERN Document Server

    Lazarus, Patrick; Champion, David J; Hessels, Jason W T; Dib, Rim

    2011-01-01

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U0142+61 following its 2006 X-ray bursts were obtained. No radio emission was detected was detected for any of our targets. The non-detections allow us to place luminosity upper limits (at 1950 MHz) of approximately L < 1.60 mJy kpc^2 for periodic emission and L < 7.6 Jy kpc^2 for single pulse emission. These are the most stringent limits yet for the magnetars observed. The resulting luminosity upper limits together with previous results are discussed, as is the importance of further radio observations of radio-loud and radio-quiet magnetars.

  4. Estimating Emissions from Railway Traffic

    DEFF Research Database (Denmark)

    Jørgensen, Morten W.; Sorenson, Spencer C.

    1998-01-01

    Several parameters of importance for estimating emissions from railway traffic are discussed, and typical results presented. Typical emissions factors from diesel engines and electrical power generation are presented, and the effect of differences in national electrical generation sources...... illustrated as well as the degree of electrification for different countries. Traffic parameters such as passenger occupancy rates, per capita freight and passenger traffic are presented for European conditions. The relationship between average train speed and distance between stops is shown for a variety...

  5. Methane Emissions from Upland Forests

    Science.gov (United States)

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

    2016-04-01

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

  6. Thermal emissivity of avian eggshells.

    Science.gov (United States)

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

    2016-04-01

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

  7. Reducing environmental emissions in tanneries.

    Science.gov (United States)

    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.

  8. Study Acoustic Emissions from Composites

    Science.gov (United States)

    Walker, James; Workman,Gary

    1998-01-01

    The purpose of this work will be to develop techniques for monitoring the acoustic emissions from carbon epoxy composite structures at cryogenic temperatures. Performance of transducers at temperatures ranging from ambient to cryogenic and the characteristics of acoustic emission from composite structures will be studied and documented. This entire effort is directed towards characterization of structures used in NASA propulsion programs such as the X-33.

  9. Estimating emissions from railway traffic

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, M.W.; Sorenson, C.

    1997-07-01

    The report discusses methods that can be used to estimate the emissions from various kinds of railway traffic. The methods are based on the estimation of the energy consumption of the train, so that comparisons can be made between electric and diesel driven trains. Typical values are given for the necessary traffic parameters, emission factors, and train loading. Detailed models for train energy consumption are presented, as well as empirically based methods using average train speed and distance between stop. (au)

  10. HONO emissions from snow surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Beine, Harry; Colussi, AgustIn J; Hoffmann, Michael R [California Institute of Technology, Environmental Science and Engineering, Pasadena, CA (United States); Amoroso, Antonio; Esposito, Giulio; Montagnoli, Mauro [Consiglio Nazionale delle Ricerche-Istituto Inquinamento Atmosferico (CNR-IIA), Roma (Italy)], E-mail: hbeine@ucdavis.edu

    2008-10-15

    Photochemical production of NO{sub x} and HONO from surface snow can significantly impact the NO{sub x}, OH, and O{sub 3} budgets in the overlying atmosphere. NO{sub x} production is driven by the solar photolysis of NO{sub 3}{sup -} within or at the surface of snowpacks. HONO, however, is a secondary species that involves H-atom transfer between natural donors and photogenerated NO{sub 2}. Here we investigate the mechanism of HONO generation in snowpacks by exploring how its emissions respond to on-and-off illumination and temperature cycles, and to the addition of various snow dopants. The presence of humic substances within or at the surface of the snowpack significantly enhances, and may be an essential requisite for HONO production. Emission fluxes of NO, NO{sub 2}, and HONO from snow surfaces were measured under controlled temperature, ozone mixing ratio and actinic flux conditions. We used natural mid-latitude surface snow as the snow substrate. Their combined peak emission fluxes reached up to {approx}3 x 10{sup 10} molecules cm{sup -2} s{sup -1}, {approx}10{sup 3} times larger than typical emissions from polar snowpacks. Less than 1% of available N was released in these experiments. We report significant post-irradiation HONO emissions from the snow. Present results indicate a strong, direct correlation between HONO emissions and the HULIS (humic-like substances) content of the snow surface.

  11. Offsetting Ongoing Methane Emissions --- An Alternative to Emission Equivalence Metrics

    Science.gov (United States)

    Clisby, N.; Enting, I. G.; Lauder, A.; Carter, J.; Cowie, A.; Henry, B.; Raupach, M. R.

    2012-12-01

    The Global Warming Potential (GWP) has been widely adopted as a metric for comparing the climate impact of different greenhouse gases. As has been frequently noted, there are many problems with using GWPs to define emission equivalence in spite of the use of GWPs for this purpose in contexts such as the Kyoto Protocol. We propose that for methane, rather than define emission equivalence, the appropriate comparison is between ongoing emissions of 0.9 to 1.0 kg of CH4 per year and one-off emissions of 1 tonne of carbon. This approach represents an approximate solution to the inverse problem of defining a forcing equivalent index (FEI) that gives exact equivalence of radiative forcing over a range of timescales. In our approach, if ongoing methane emissions are offset by a one-off carbon removal that is built up with 40-year e-folding time, then the result is close to radiatively neutral over periods from years to centuries. In contrast, the GWP provides radiative equivalence (in integrated terms) only at a single time, with large discrepancies at other times. Our approach also follows from consideration of greenhouse gas stabilisation, since stabilising atmospheric CO2 requires an approximate cap on total emissions, while stabilising methane requires stabilisation of ongoing emissions. Our quantitative treatment recognises that, on time scales of centuries, removal of 1 tonne of carbon only lowers the atmospheric carbon content by 0.3 to 0.35 tonnes. We discuss the implications for rangeland grazing systems. In the absence of effective mitigation techniques for methane from rangeland systems, this approach may provide an attractive offset mechanism in spite of requiring that woody vegetation be established and maintained over about 15% of the landscape, or an equivalent amount of carbon storage in soil.

  12. 基于SPCE061A的多自由度假手语音控制系统的研究%Research of Speech Recognition Control System for Prosthetic Hand Based on SPCE061A Microcontroller Core

    Institute of Scientific and Technical Information of China (English)

    宋超; 姜力; 赵大威

    2006-01-01

    介绍了利用语音识别和无线传输技术实现对多自由度假手的远程语音控制系统.用该语音控制系统弥补了基于肌电信号(EMG)和脑电信号(EEG)控制系统的不足.从而使多自由度假手进一步满足残疾人的需要,给残疾人带来更多的方便.该语音控制系统结构灵活紧凑,质量轻,能耗低,易于功能扩展,便于在以后的工作中增加用户所需的功能.

  13. Martian Analogues Emissivity Spectra From the Berlin Emissivity Database (BED)

    Science.gov (United States)

    Maturilli, A.; Helbert, J.; Moroz, L.

    2006-12-01

    Remote sensing infrared spectroscopy is the principal field of investigation for planetary surfaces composition. Past, present and future missions to bodies in the solar system include in their payload instruments measuring the emerging radiation in the infrared range. For the interpretation of the measured data an emissivity spectral library of planetary analog materials is needed. The Berlin Emissivity Database (BED) currently contains emissivity spectra of plagioclase and potassium feldspars, low Ca and high Ca pyroxenes, olivine, elemental sulphur, and Martian analogue minerals, measured in the wavelength range from 7 to 22 microns as a function of particle size. For each sample we measured the spectra of four particle size separates ranging from 0 to 250 microns. The device we used is built at DLR (Berlin) and is coupled to a Fourier transform infrared spectrometer (Bruker IFS 88), purged with dry air and equipped with a cooled detector (MCT). All spectra were acquired with a spectral resolution of 4 cm-1. We present here the results of our analysis on well knew and characterized Martian analogue minerals: JSC Mars-1, Salten Skov, and Palagonite from Mauna Kea, Hawaii. We are currently working to upgrade our emissivity facility. A new spectrometer (Bruker VERTEX 80v) and new detectors will allow us to measure the emissivity of samples in the wavelength range from 1 to 50 microns, even in a vacuum environment.

  14. The Berlin emissivity database (BED)

    Science.gov (United States)

    Maturilli, A.; Helbert, J.; Moroz, L.

    2008-03-01

    Remote-sensing infrared spectroscopy is the principal field of investigation for planetary surfaces composition. Past, present and future missions to the solar system bodies include in their payload, instruments measuring the emerging radiation in the infrared range. Apart from measuring the reflected radiance, more and more spacecrafts are equipped with instruments measuring directly the emitted radiation from the planetary surface. The emitted radiation is not only a function of the composition of the material but also of its texture and especially the grain size distribution. For the interpretation of the measured data an emissivity spectral library of planetary analogue materials in grain size fractions appropriate for planetary surfaces is needed. The Berlin emissivity database (BED) presented here is focused on relatively fine-grained size separates, providing thereby a realistic basis for the interpretation of thermal emission spectra of planetary regoliths. The BED is therefore complimentary to existing thermal emission libraries, like the ASU library for example. BED currently contains emissivity spectra of plagioclase and potassium feldspars, low Ca and high Ca pyroxenes, olivine, elemental sulfur, Martian analogue minerals and volcanic soils, and a lunar highland soil sample measured in the wavelength range from 7 to 22 μm as a function of particle size. For each sample we measured the spectra of four particle size separates ranging from <25 to 250 μm. The device we used is built at DLR (Berlin) and is coupled to a Fourier-transform infrared spectrometer Bruker IFS 88 purged with dry air and equipped with a nitrogen-cooled MCT detector. All spectra were acquired with a spectral resolution of 4 cm -1. We are currently working on upgrading our emissivity facility. A new spectrometer (Bruker VERTEX 80 V) and new detectors will allow us to measure the emissivity of samples in the wavelength range from 1 to 50 μm in a vacuum environment. This will be

  15. 40 CFR 61.123 - Emission testing.

    Science.gov (United States)

    2010-07-01

    ..., at its option, observe the test. (c) An emission test shall be conducted at each operational calciner or nodulizing kiln. If emissions from a calciner or nodulizing kiln are discharged through more than... calciner or kiln shall be the sum of the emission rates from each of the stacks. (d) Each emission...

  16. PAHFIT: Properties of PAH Emission

    Science.gov (United States)

    Smith, J. D.; Draine, Bruce

    2012-10-01

    PAHFIT is an IDL tool for decomposing Spitzer IRS spectra of PAH emission sources, with a special emphasis on the careful recovery of ambiguous silicate absorption, and weak, blended dust emission features. PAHFIT is primarily designed for use with full 5-35 micron Spitzer low-resolution IRS spectra. PAHFIT is a flexible tool for fitting spectra, and you can add or disable features, compute combined flux bands, change fitting limits, etc., without changing the code. PAHFIT uses a simple, physically-motivated model, consisting of starlight, thermal dust continuum in a small number of fixed temperature bins, resolved dust features and feature blends, prominent emission lines (which themselves can be blended with dust features), as well as simple fully-mixed or screen dust extinction, dominated by the silicate absorption bands at 9.7 and 18 microns. Most model components are held fixed or are tightly constrained. PAHFIT uses Drude profiles to recover the full strength of dust emission features and blends, including the significant power in the wings of the broad emission profiles. This means the resulting feature strengths are larger (by factors of 2-4) than are recovered by methods which estimate the underlying continuum using line segments or spline curves fit through fiducial wavelength anchors.

  17. Some properties of emission coordinates

    CERN Document Server

    Pozo, J M

    2006-01-01

    4 emitters broadcasting an increasing electromagnetic signal generate a system of relativistic coordinates for the space-time, called emission coordinates. Their physical realization requires an apparatus similar to the one of the Global Navigation Satellite Systems (GNSS). Several relativistic corrections are utilized for the current precisions, but the GNSS are conceived as classical (Newtonian) systems, which has deep implications in the way of operating them. The study of emission coordinates is an essential step in order to develop a fully relativistic theory of positioning systems. This talk presents some properties of emission coordinates. In particular, we characterize how any observer sees a configuration of satellites giving a degenerated system and show that the trajectories of the satellites select a unique privileged observer at each point and, for any observer, a set of 3 orthogonal spatial axes.

  18. Spontaneous emission and absorber theory

    Science.gov (United States)

    Pegg, David T.

    1997-01-01

    One of the long term interests of George Series was the construction of a theory of spontaneous emission which does not involve field quantisation. His approach was written in terms of atomic operators only and he drew a parallel with the Wheeler-Feynman absorber theory of radiation. By making a particular extra postulate, he was able to obtain the correct spontaneous emission rate and the Lamb shift reasonably simply and directly. An examination of his approach indicates that this postulate is physically reasonable and the need for it arises because quantisation in his theory occurs after the response of the absorber has been accounted for by means of the radiative reaction field. We review briefly an alternative absorber theory approach to spontaneous emission based on the direct action between the emitting atom and a quantised absorber, and outline some applications to more recent effects of interest in quantum optics.

  19. Cleaning the Diesel Engine Emissions

    DEFF Research Database (Denmark)

    Christensen, Thomas Budde

    necessitates a rethinking of public governance that involve multilevel governance and integrating technology push and pull strategies. The agenda requires a re-conceptualisation of the innovation concept with special emphasis on value chain dynamics. The paper includes an analysis of the Danish innovation......This paper examines how technologies for cleaning of diesel emission from road vehicles can be supported by facilitating a technology push in the Danish automotive emission control industry. The European commission is at present preparing legislation for the euro 5 emission standard (to be enforced...... policy based on Michael Porters cluster theory. The paper however suggest that the narrow focus on productivity and economic growth in Porters theory should be qualified and integrated with a broader scope of societal policy aims including social and environmental issues. This suggestion also...

  20. Large Engine Emission Reduction - LEER

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-10-15

    The target of the project LEER is to find the most cost-effective means of today to reduce exhaust gas emissions, particularly NO{sub x} and particulates, of power-plant and ship propulsion diesel engines. The methods are controlling of the combustion and exhaust gas after-treatment. As research methods, theoretical and literature studies as well as engine tests are used. Using the state of the art technology in the whole engine process from combustion control to after treatment is vital for keeping the product competitive in today's engine market. The project consists of two main tasks, Performance and Emission. The Performance task deals with controlling the combustion for optimising the trade-off between fuel consumption and pollutant formation, NO{sub x} in particular. The Emission task concentrates on improving the after treatment technology in particulate reduction, and understanding the particulate formation by gaining information of particulate nature and composition. (orig.)

  1. Air Emission Inventory for the Idaho National Engineering and Environmental Laboratory - Calendar Year 1999 Emission Report

    Energy Technology Data Exchange (ETDEWEB)

    Zohner, S.K.

    2000-05-30

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

  2. Air emission inventory for the Idaho National Engineering Laboratory: 1994 emissions report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This report Presents the 1994 update of the Air Emission inventory for the Idaho National Engineering Laboratory (INEL). The INEL Air Emission Inventory documents sources and emissions of non-radionuclide pollutants from operations at the INEL. The report describes the emission inventory process and all of the sources at the INEL, and provides non-radionuclide emissions estimates for stationary sources.

  3. Air Emission Inventory for the Idaho National Engineering and Environmental Laboratory - Calendar Year 1998 Emissions Report

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Zohner

    1999-10-01

    This report presents the 1998 calendar year update of the Air Emission Inventory for the Idaho National Engineering and Environmental Laboratory (INEEL). The INEEL Air Emission Inventory documents sources and emissions of nonradionuclide pollutants from operations at the INEEL. The report describes the emission inventory process and all of the sources at the INEEL, and provides nonradiological emissions estimates for stationary sources.

  4. Isoprene emission from wetland sedges

    Science.gov (United States)

    Ekberg, A.; Arneth, A.; Hakola, H.; Hayward, S.; Holst, T.

    2009-04-01

    High latitude wetlands play an important role for the surface-atmosphere exchange of carbon dioxide (CO2) and methane (CH4), but fluxes of biogenic volatile organic compounds (BVOC) in these ecosystems have to date not been extensively studied. This is despite BVOC representing a measurable proportion of the total gaseous C fluxes at northern locations and in the face of the high temperature sensitivity of these systems that requires a much improved process understanding to interpret and project possible changes in response to climate warming. We measured emission of isoprene and photosynthetic gas exchange over two growing seasons (2005-2006) in a subarctic wetland in northern Sweden with the objective to identify the physiological and environmental controls of these fluxes on the leaf scale. The sedge species Eriophorum angustifolium and Carex rostrata were both emitters of isoprene. Springtime emissions were first detected after an accumulated diurnal mean temperature above 0°C of about 100 degree days. Maximum measured growing season standardized (basal) emission rates (20°C, 1000 μmol m-2 s-1) were 1075 (2005) and 1118 (2006) μg C m-2 (leaf area) h-1 in E. angustifolium, and 489 (2005) and 396 (2006) μg C m-2 h-1 in C. rostrata. Over the growing season, basal isoprene emission varied in response to the temperature history of the last 48 h. Seasonal basal isoprene emission rates decreased with leaf nitrogen (N), which may be explained by the typical growth and resource allocation pattern of clonal sedges as the leaves age. The observations were used to model emissions over the growing season, accounting for effects of temperature history, links to leaf assimilation rate and the light and temperature dependencies of the cold-adapted sedges.

  5. Transportable Emissions Testing Laboratory for Alternative Vehicles Emissions Testing

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Nigel

    2012-01-31

    The overall objective of this project was to perform research to quantify and improve the energy efficiency and the exhaust emissions reduction from advanced technology vehicles using clean, renewable and alternative fuels. Advanced vehicle and alternative fuel fleets were to be identified, and selected vehicles characterized for emissions and efficiency. Target vehicles were to include transit buses, school buses, vocational trucks, delivery trucks, and tractor-trailers. Gaseous species measured were to include carbon monoxide, carbon dioxide, oxides of nitrogen, hydrocarbons, and particulate matter. An objective was to characterize particulate matter more deeply than by mass. Accurate characterization of efficiency and emissions was to be accomplished using a state-of-the-art portable emissions measurement system and an accompanying chassis dynamometer available at West Virginia University. These two units, combined, are termed the Transportable Laboratory. An objective was to load the vehicles in a real-world fashion, using coast down data to establish rolling resistance and wind drag, and to apply the coast down data to the dynamometer control. Test schedules created from actual vehicle operation were to be employed, and a specific objective of the research was to assess the effect of choosing a test schedule which the subject vehicle either cannot follow or can substantially outperform. In addition the vehicle loading objective was to be met better with an improved flywheel system.

  6. Measurement of Fugitive Dust Emissions and Visible Emissions.

    Science.gov (United States)

    McKee, Herbert C.

    The method of measuring fugitive dust emission utilized by the Texas Air Control Board is described in this presentation for the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. The measuring procedure, precautions, expected results, and legal acceptance of the method are…

  7. Infrared emission from M31

    Science.gov (United States)

    Habing, H. J.; Miley, G.; Young, E.; Baud, B.; Boggess, N.; Clegg, P. E.; Harris, S.; Rowan-Robinson, M.; De Jong, T.; Raimond, E.

    1984-01-01

    Maps of M31 have been obtained at wavelengths of 12, 25, 60, and 100 microns. Emission is detected from the center and from a ring of 50 arcmin radius. The ring is that also seen in H I, in H II, and in radio continuum radiation. The spectrum of the central emission suggests a hotter dust temperature than in the ring. M31 is a weak infrared source, the radiation measured longward of 12 microns being only 3 percent of its total luminosity. The two closest companion galaxies, M32 and NGC 205, have also been detected.

  8. Ordering multiple soft gluon emissions

    CERN Document Server

    Ángeles-Martínez, René; Seymour, Michael H

    2016-01-01

    We present an expression for the QCD amplitude for a general hard scattering process with any number of soft gluon emissions, to one-loop accuracy. The amplitude is written in two different but equivalent ways: as a product of operators ordered in dipole transverse momentum and as a product of loop-expanded currents. We hope that these results will help in the development of an all-orders algorithm for multiple emissions that includes the full colour structure and both the real and imaginary contributions to the amplitude.

  9. NEC-2020 emission reduction scenarios

    DEFF Research Database (Denmark)

    Slentø, Erik; Nielsen, Ole-Kenneth; Hoffmann, Leif

    The upcoming NEC-2020 EU directive sets up emission ceilings for NOX, SO2, NH3, NMVOC and PM in order to meet the environmental exposure targets of the Thematic Strategy. This report contains an assessment of intermediary emission reduction scenarios for Denmark, computed by the GAINS model 2007......, which serves as the basis for the pending negotiations in EU. The assessment is brought up to date by including a brief evaluation of the new reduction scenarios published in 2008, founding the European Commission NEC-2020 directive proposal....

  10. Sonification of acoustic emission data

    Science.gov (United States)

    Raith, Manuel; Große, Christian

    2014-05-01

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

  11. NMF on positron emission tomography

    DEFF Research Database (Denmark)

    Bödvarsson, Bjarni; Hansen, Lars Kai; Svarer, Claus;

    2007-01-01

    In positron emission tomography, kinetic modelling of brain tracer uptake, metabolism or binding requires knowledge of the cerebral input function. Traditionally, this is achieved with arterial blood sampling in the arm or as shown in (Liptrot, M, et al., 2004) by non-invasive K-means clustering....... We propose another method to estimate time-activity curves (TAC) extracted directly from dynamic positron emission tomography (PET) scans by non-negative matrix factorization (NMF). Since the scaling of the basis curves is lost in the NMF the estimated TAC is scaled by a vector alpha which...

  12. Particle emissions from biomass combustion

    Science.gov (United States)

    Chabadová, Jana; Papučík, Štefan; Nosek, Radovan

    2014-08-01

    The paper presents an analysis of the impact of fuel feed to power and emissions parameters of the automatic domestic boiler for combustion of wood pellets. For the analysis has been proposed an experimental methodology of boiler measuring. The investigated boiler is designed for operation in domestic heating system. It has heat power equal to 18 kW. Concentrations of flue gas species were registered at the exit the boiler and based on the measured parameters was carried out evaluation of the impact of the fuel feed to heat power and production of emissions.

  13. The Role of Global Emission Inventory of Carbonaceous Emissions

    Science.gov (United States)

    Fatima, H.; Sharma, O. P.; Updhyaya, H.

    2010-12-01

    Aerosols - liquid or solid particles suspended in the air - are important constituents of the global atmosphere. They have a direct effect on climate by scattering and/or absorbing solar radiation modifying the radiative balance of the atmosphere and indirect effect by acting as condensation nuclei, their increase in number concentration may give rise to increased number of cloud condensation nuclei, which might increase the droplet concentration with relatively smaller size droplets for fixed liquid water content, making clouds more reflective (Twomey, 1977). Recent measurements show that atmospheric black carbon (BC) and organic carbon (OC) aerosol particles frequently contribute significantly to the total aerosol mass (Novakov et al. 1997). BC is emitted as primary particles from incomplete combustion process, such as fossil fuel and biomass burning, and therefore much atmospheric BC is of anthropogenic origin. OC is emitted as both primary particles and by secondary production from gaseous compounds via condensation or gas phase oxidation of hydrocarbons. Primary organic aerosols come from both anthropogenic sources (fossil fuel and biomass burning) and from natural sources (such as debris, pollen, spores, and algae). Carbonaceous aerosols make up a large but highly variable fraction of the atmospheric aerosol. Black carbon aerosols absorb the solar radiation and induce positive forcing whereas organic matter aerosols reflect solar radiation and produce negative forcing. Various emission inventories have been developed for carbonaceous aerosols. Detailed emission inventories for both BC and OC have been developed (e.g., Penner et al., 1993; Cooke and Wilson, 1996; Liousse et al., 1996; Cooke et al., 1999, Bond et al. 2004) that consider both fossil fuel and biomass components. The inventories of biomass- burning BC and OC particles are more difficult to constrain than fossil fuel emissions, owing to the paucity of data. In the present study we have compared the

  14. Emission Trading under the Kyoto Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Holtsmark, Bjart; Hagem, Cathrine

    1998-12-01

    This report discusses the potential gains from emission trading and raises some crucial questions. It shows that the total costs of the Kyoto Protocol could be reduced by about 95% through emission trading. Emission trading is an option also in the domestic arenas. The governments of the Annex B countries may allocate emission quotas to local enterprises as emission permits. Thus new markets for greenhouse gas emission quotas may emerge, domestically and internationally. It is emphasized that emission trading at the national and international levels must be discussed separately. The Nordic governments, for example, will find several good reasons for supporting emission trading at the international level if not necessarily domestically. The Nordic countries have already implemented domestic taxes on CO{sub 2} emissions and this tax policy could be sustained while these governments support and take part in emission trading at the international level.The report also considers a possible side effect of emission trading: free emission trading among Annex B countries could reduce the total abatement compared to a non-tradable policy as a consequence of the fact that some of the countries that are in transition to a market economy may be given emission limitations above their business-as-usual emissions. 40 refs., 7 figs., 4 tabs.

  15. Emissions Trading: Trends and Prospects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This paper provides the latest developments of announced, proposed and existing greenhouse gas emissions trading schemes (ETS) around the world since 2006. It also examines different potential design options for ETS (e.g. coverage, allocation mode, provision for offsets), and how these options are treated in the existing, announced or proposed schemes.

  16. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter;

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  17. Radio emission in Mercury magnetosphere

    CERN Document Server

    Varela, J; Brun, A S; Pantellini, F; Zarka, P

    2016-01-01

    Context: Active stars possess magnetized wind that has a direct impact on planets that can lead to radio emission. Mercury is a good test case to study the effect of the solar wind and interplanetary magnetic field on radio emission driven in the planet magnetosphere. Such studies could be used as proxies to characterize the magnetic field topology and intensity of exoplanets. Aims: The aim of this study is to quantify the radio emission in the Hermean magnetosphere. Methods: We use the MHD code PLUTO in spherical coordinates with an axisymmetric multipolar expansion for the Hermean magnetic field, to analyze the effect of the interplanetary magnetic field (IMF) orientation and intensity, as well as the hydrodynamic parameters of the solar wind (velocity, density and temperature), on the net power dissipated on the Hermean day and night side. We apply the formalism derived by Zarka [2001, 2007] to infer the radio emission level from the net dissipated power. We perform a set of simulations with different hydr...

  18. Exploiting dual otoacoustic emission sources

    Science.gov (United States)

    Abdala, Carolina; Kalluri, Radha

    2015-12-01

    Two distinct processes generate otoacoustic emissions (OAEs). Reflection-source emissions, here recorded as stimulus frequency OAEs, are optimally informative at low sound levels and are more sensitive to slight hearing loss; they have been linked to cochlear amplifier gain and tuning. Distortion-source emissions are strongest at moderate-high sound levels and persist despite mild hearing loss; they likely originate in the nonlinear process of hair cell transduction. In this preliminary study, we exploit the unique features of each by generating a combined reflection-distortion OAE profile in normal hearing and hearing-impaired ears. Distortion-product (DP) and stimulus-frequency (SF) OAEs were recorded over a broad range of stimulus levels and frequencies. Individual I/O and transfer functions were generated for both emission types in each ear, and OAE peak strength, compression threshold, and rate of compression were calculated. These combined SFOAE and DPOAE features in normal and hearing-impaired ears may provide a potentially informative and novel index of hearing loss. This is an initial step toward utilizing OAE source in characterizing cochlear function and dysfunction.

  19. Axion emission from neutron stars

    Science.gov (United States)

    Iwamoto, N.

    1984-01-01

    It is shown that axion emission from neutron stars is the dominant energy-loss mechanism for a range of values of the Peccei-Quinn symmetry-breaking scale (F) not excluded by previous constraints. This gives the possibility of obtaining a better bound on F from measurements of surface temperature of neutron stars.

  20. MICRO AUTO GASIFICATION SYSTEM: EMISSIONS ...

    Science.gov (United States)

    A compact, CONEX-housed waste to energy unit, Micro Auto Gasification System (MAGS), was characterized for air emissions from burning of military waste types. The MAGS unit is a dual chamber gasifier with a secondary diesel-fired combustor. Eight tests were conducted with multiple waste types in a 7-day period at the Kilauea Military Camp in Hawai’i. The emissions characterized were chosen based on regulatory emissions limits as well as their ability to cause adverse health effects on humans: particulate matter (PM), mercury, heavy metals, volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Three military waste feedstock compositions reflecting the variety of wastes to be encountered in theatre were investigated: standard waste (SW), standard waste with increased plastic content (HP), standard waste without SW food components but added first strike ration (FSR) food and packaging material (termed FSR). A fourth waste was collected from the Kilauea dumpster that served the dining facility and room lodging (KMC). Limited scrubber water and solid ash residue samples were collected to obtain a preliminary characterization of these effluents/residues.Gasifying SW, HP, and KMC resulted in similar PCDD/PCDF stack concentrations, 0.26-0.27 ng TEQ/m3 at 7% O2, while FSR waste generated a notably higher stack concentration of 0.68 ng TEQ/m3 at 7% O2. The PM emission

  1. Exploiting Dual Otoacoustic Emission Sources

    Science.gov (United States)

    Abdala, Carolina; Kalluri, Radha

    2016-01-01

    Two distinct processes generate otoacoustic emissions (OAEs). Reflection-source emissions, here recorded as stimulus frequency OAEs, are optimally informative at low sound levels and are more sensitive to slight hearing loss; they have been linked to cochlear amplifier gain and tuning. Distortion-source emissions are strongest at moderate-high sound levels and persist despite mild hearing loss; they likely originate in the nonlinear process of hair cell transduction. In this preliminary study, we exploit the unique features of each by generating a combined reflection-distortion OAE profile in normal hearing and hearing-impaired ears. Distortion-product (DP) and stimulus-frequency (SF) OAEs were recorded over a broad range of stimulus levels and frequencies. Individual I/O and transfer functions were generated for both emission types in each ear, and OAE peak strength, compression threshold, and rate of compression were calculated. These combined SFOAE and DPOAE features in normal and hearing-impaired ears may provide a potentially informative and novel index of hearing loss. This is an initial step toward utilizing OAE source in characterizing cochlear function and dysfunction. PMID:27695142

  2. Methane emissions from Carex rostrata

    Science.gov (United States)

    Yelverton, C. A.; Varner, R. K.; Roddy, S.; Noyce, G. L.

    2013-12-01

    Peatlands, especially in northern regions, are known for their contribution to the increase of methane (CH4) in the atmosphere. Methane emissions from peatlands are strongly correlated with water table, temperature, and species composition. Sedges, in particular, are a conduit for the release of CH4 directly to the atmosphere. This study examines the impact of clipping and sealing sedges (Carex rostrata) on CH4 emissions from a temperate peatland (Sallie's Fen, Barrington, NH, USA). Measurements of CH4 fluxes, dissolved CH4, and environmental conditions were made over a six-year period. Data from 2008 to 2013 show that the presence of Carex rostrata in this peatland increases CH4 emissions. Clipped plots have both lower seasonal and annual CH4 emissions, compared to control plots. By studying the type of environment associated with C. rostrata through measurements of water-table depth, pore water characteristics, and the peat, surface, and air temperature of each surrounding location, further studies will show how these factors affect the rate at which CH4 is emitted into the atmosphere.

  3. Imaging FTIR emissivity measurement method

    Science.gov (United States)

    Burdette, Edward M.; Nichols, C. Spencer; Lane, Sarah E.; Prussing, Keith F.; Cathcart, J. Michael

    2013-09-01

    Though many materials behave approximately as greybodies across the long-wave infrared (LWIR) waveband, certain important infrared (IR) scene modeling materials such as brick and galvanized steel exhibit more complex optical properties1. Accurately describing how non-greybody materials interact relies critically on the accurate incorporation of the emissive and reflective properties of the in-scene materials. Typically, measured values are obtained and used. When measured using a non-imaging spectrometer, a given material's spectral emissivity requires more than one collection episode, as both the sample under test and a standard must be measured separately. In the interval between episodes changes in environment degrade emissivity measurement accuracy. While repeating and averaging measurements of the standard and sample helps mitigate such effects, a simultaneous measurement of both can ensure identical environmental conditions during the measurement process, thus reducing inaccuracies and delivering a temporally accurate determination of background or `down-welling' radiation. We report on a method for minimizing temporal inaccuracies in sample emissivity measurements. Using a LWIR hyperspectral imager, a Telops Hyper-Cam2, an approach permitting hundreds of simultaneous, calibrated spectral radiance measurements of the sample under test as well as a diffuse gold standard is described. In addition, we describe the data reduction technique to exploit these measurements. Following development of the reported method, spectral reflectance data from 10 samples of various materials of interest were collected. These data are presented along with comments on how such data will enhance the fidelity of computer models of IR scenes.

  4. INFRARED EMISSIVITY OF CONDUCTING POLYMERS

    Institute of Scientific and Technical Information of China (English)

    WAN Meixiang; LI Suzhen; LI Junchao; DONG Haiou

    1991-01-01

    The infrared emissivity of conducting polymers in 8-20μm and at 50-150℃ in the direction of normal line has been measured as a function of wavelength, conductivity at room temperature,counterion, doping levels, measuring temperature and thickness of sample.

  5. Greenhouse Gas Emission Accounting 2

    NARCIS (Netherlands)

    Amstel, van A.R.; Kroeze, C.; Janssen, L.H.J.M.; Olivier, J.G.J.

    1999-01-01

    Here, a more detailed analysis is made of differences between national emission estimates, including the second National Communications and global inventories such as EDGAR 2.0 and atmospheric concentration data. This follow-up report provides background information for IPCC expert meetings held on

  6. Recharging Emission-Free Cars

    Institute of Scientific and Technical Information of China (English)

    CORRIE; DOSH

    2008-01-01

    New York dealership begins sales of China-made electric vehicles In the 2006 documentary Who Killed the Electric Car?, Director Chris Paine showed how auto manufacturers, the oil industry, government officials and consumers suppressed the development of allelectric, emission-free vehicles. Now, with

  7. Tradeable Emission Permits in Oligopoly

    NARCIS (Netherlands)

    Fershtman, C.; de Zeeuw, A.J.

    1996-01-01

    The paper considers an oligopolistic industry in which pollution is a by-product of production. Firms are assumed to have emission permits that restrict the amount that they pollute. These permits are assumed to be tradeable and the paper discusses a structure in which the same set of firms operates

  8. Constraining Radio Emission from Magnetars

    NARCIS (Netherlands)

    Lazarus, P.; Kaspi, V.M.; Champion, D.; Hessels, J.W.T.; Dib, R.

    2012-01-01

    We report on radio observations of five magnetars and two magnetar candidates carried out at 1950 MHz with the Green Bank Telescope in 2006-2007. The data from these observations were searched for periodic emission and bright single pulses. Also, monitoring observations of magnetar 4U 0142+61 follow

  9. Keep the focus on emissions

    Science.gov (United States)

    Clack, C.; Benson, S. M.; Peterson, P.; Long, J. C. S.

    2016-12-01

    Most think that the major battle over climate is between those that want to solve the climate problem and the climate deniers. But there is another conflict, perhaps equally significant between people who all agree climate is a problem but who disagree radically about what they think the solution is. The imperative for stopping further climate change is to stop GHG emissions and the first energy sector of importance is electricity. Every major plan to eliminate emmissions from energy requires a carbon-free electricity system. The most popular idea about how to do this is to use all renewable energy, i.e. solar and wind power. But no one has ever built a large scale 100% renewable energy system and the few examples we have about regions that have tried are not encouraging. As the percentage of renewable energy goes up, ensuring a reliable supply often requires a fossil-based back-up system, so emissions can actually increase. Also, 100% renewable systems rely on massive deployment rates, far beyond any historical precident and often assume that adequate energy storage will "happen" through a combination of currently unavailable technologies. This approach is about adding renewable capacity, not about reducing emissions. Sweden provides a counter example that relies entirely on nuclear power and hydro and has an emission-free, reliable energy system. Likewise, biofuel is often cited as a climate-friendly substitute for petroleum-based fuels. Life-cycle analsyis indicates biofuels are often worse than petroleum-based fuels. We focus efficiency measures on buildings, but efficiency in transportation is even more important because we don't really have the fuel that is carbon neutral. Vehicle efficiency and reductions in vehicle miles traveled does better to address emissions. As mitigation is so important, climate advocates used to think discussion of adaptation was a distraction that should be avoided. But losing track of the need to eliminate emissions is the real

  10. Ionic emission from Taylor cones

    Science.gov (United States)

    Castro Reina, Sergio

    Electrified Taylor cones have been seen as an efficient way to generate thrust for space propulsion. Especially the pure ionic regime (PIR) combines a very high specific impulse (thrust per unit mass) and efficiency, which is very important to reduce fuel transportation costs. The PIR has been primarily based on electrosprays of liquid metals [Swatik and Hendricks 1968, Swatik 1969]. However, emissions dominated by or containing exclusively ions have also been observed from nonmetallic purely ionic substances, initially sulfuric acid [Perel et al. 1969], and more recently room temperature molten salts referred to as ionic liquids (ILs) [Romero-Sanz et al. 2003]. The recent use of the liquid metal ion source (LMIS) with ILs, becoming this "new" source to be known as ionic liquid ion source (ILIS) [Lozano and Martinez-Sanchez 2005], has shown important differences on the emission from Taylor cones with the traditional hollow capillary. This new source seems to be more flexible than the capillary [Paulo, Sergio, carlos], although its low emission level (low thrust) is an important drawback from the space propulsion point of view. Throughout the thesis I have studied some aspects of the ionic emission from ionic liquid Taylor cones and the influence of the properties of the liquids and the characteristic of source on the emission. I have unraveled the reason why ILIS emits such low currents (˜200 nA) and found a way to solve this problem increasing the current up to capillary levels (˜1000 nA) [Castro and Fernandez de la Mora 2009]. I have also tried to reduce ion evaporation while reducing the emitted droplet size in order to increase the thrust generated while keeping the efficiency relatively high and I have measured the energy of evaporation of several cations composing ionic liquids, mandatory step to understand ionic evaporation.

  11. Variable Emissivity Through MEMS Technology

    Science.gov (United States)

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

    2000-01-01

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

  12. AIRFORCE. Aircraft emissions and radiative forcing from emissions

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  13. Nanophotonic Devices - Spontaneous Emission Faster than Stimulated Emission

    Science.gov (United States)

    2014-11-04

    the onset of unacceptable Ohmic losses, defined as non-radiative losses >50%. 15. SUBJECT TERMS spontaneous emission, optical antenna , stimulated...to a proper optical antenna at the right scale(16). Metal optics has been able to shrink lasers to the nanoscale(17–20), but high losses in metal...11. Farahani JN, Pohl DW, Eisler H-J, Hecht B (2005) Single Quantum Dot Coupled to a Scanning Optical Antenna : A Tunable Superemitter. Phys Rev

  14. Isoprene emission from wetland sedges

    Directory of Open Access Journals (Sweden)

    A. Ekberg

    2009-04-01

    Full Text Available High latitude wetlands play an important role for the surface-atmosphere exchange of carbon dioxide (CO2 and methane (CH4, but fluxes of biogenic volatile organic compounds (BVOC in these ecosystems have to date not been extensively studied. This is despite BVOC representing a measurable proportion of the total gaseous C fluxes at northern locations and in the face of the high temperature sensitivity of these systems that requires a much improved process understanding to interpret and project possible changes in response to climate warming. We measured emission of isoprene and photosynthetic gas exchange over two growing seasons (2005–2006 in a subarctic wetland in northern Sweden with the objective to identify the physiological and environmental controls of these fluxes on the leaf scale. The sedge species Eriophorum angustifolium and Carex rostrata were both emitters of isoprene. Springtime emissions were first detected after an accumulated diurnal mean temperature above 0°C of about 100 degree days. Maximum measured growing season standardized (basal emission rates (20°C, 1000 μmol m−2 s−1 were 1075 (2005 and 1118 (2006 μg C m−2 (leaf area h−1 in E. angustifolium, and 489 (2005 and 396 (2006 μg C m−2 h−1 in C. rostrata. Over the growing season, basal isoprene emission varied in response to the temperature history of the last 48 h. Seasonal basal isoprene emission rates decreased with leaf nitrogen (N, which may be explained by the typical growth and resource allocation pattern of clonal sedges as the leaves age. The observations were used to model emissions over the growing season, accounting for effects of temperature history, links to leaf assimilation rate and the light and temperature dependencies of the cold-adapted sedges.

  15. AP-42 Emissions Factors (WebFIRE)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Emissions factors have long been the fundamental tool in developing national, regional, state, and local emissions inventories for air quality management decisions...

  16. CHP Energy and Emissions Savings Calculator

    Science.gov (United States)

    Download the CHP Emissions Calculator, a tool that calculates the difference between the anticipated carbon dioxide, methane, nitrous oxide, sulfur dioxide, and nitrogen oxide emissions from a CHP system to those of a separate heat and power system.

  17. Summary of emissions associated with propylene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hume, G.

    1988-11-01

    This summary describes the industrial production and uses of propylene oxide, documents the methods of calculation used to estimate emissions, and lists the major facilities emitting propylene oxide, along with their estimated emissions.

  18. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

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

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

  19. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

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

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

  20. Compliance and Emissions Data Reporting Interface (CEDRI)

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPA regulations codified in 40 CFR Part 60 and 63 require affected sources to perform emissions source tests, conduct continuous emissions monitoring, and submit...

  1. Natural wetland emissions of methylated trace elements

    NARCIS (Netherlands)

    Vriens, B.; Lenz, M.; Charlet, L.; Berg, M.; Winkel, L.H.E.

    2014-01-01

    Natural wetlands are well known for their significant methane emissions. However, trace element emissions via biomethylation and subsequent volatilization from pristine wetlands are virtually unstudied, even though wetlands constitute large reservoirs for trace elements. Here we show that the averag

  2. Air Emissions Sources, Charts and Maps

    Data.gov (United States)

    U.S. Environmental Protection Agency — Air Emissions provides (1) interactive charts supporting national, state, or county charts, (2) county maps of criteria air pollutant emissions for a state, and (3)...

  3. Silicon Array for Multi-particle Emission

    Institute of Scientific and Technical Information of China (English)

    XU; Xin-xing; LIN; Cheng-jian; SUN; Li-jie; BAO; Peng-fei; YANG; Lei; YANG; Feng; ZHANG; Huan-qiao; LIU; Zu-hua; JIA; Hui-ming; MA; Nan-ru

    2013-01-01

    Remarkable progress in the study of two-proton emission has been made in recent years.One of the next destinations is the realization of high-precision direct measurements of decay-energy and emission-angle correlations inβ-delayed two-proton(β2p)emission.We have studiedβ2p correlated emission of the ground state of 26P at the proton drip line with the direct measurement at the National

  4. Annual Danish Emissions Inventory Report to UNECE

    DEFF Research Database (Denmark)

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

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

  5. Controlling nanowire emission profile using conical taper

    DEFF Research Database (Denmark)

    Gregersen, Niels; Nielsen, Torben Roland; Mørk, Jesper

    2008-01-01

    The influence of a conical taper on nanowire light emission is studied. For nanowires with divergent output beams, the introduction of tapers improves the emission profile and increase the collection efficiency of the detection optics.......The influence of a conical taper on nanowire light emission is studied. For nanowires with divergent output beams, the introduction of tapers improves the emission profile and increase the collection efficiency of the detection optics....

  6. Annual Danish Emissions Inventory Report to UNECE

    DEFF Research Database (Denmark)

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

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

  7. Spontaneous Emission in Nonlocal Materials

    CERN Document Server

    Ginzburg, Pavel; Nasir, Mazhar E; Olvera, Paulina Segovia; Krasavin, Alexey V; Levitt, James; Hirvonen, Liisa M; Wells, Brian; Suhling, Klaus; Richards, David; Podolskiy, Viktor A; Zayats, Anatoly V

    2016-01-01

    Light-matter interactions can be dramatically modified by the surrounding environment. Here we report on the first experimental observation of molecular spontaneous emission inside a highly nonlocal metamaterial based on a plasmonic nanorod assembly. We show that the emission process is dominated not only by the topology of its local effective medium dispersion, but also by the nonlocal response of the composite, so that metamaterials with different geometric parameters but the same local effective medium properties exhibit different Purcell factors. A record-high enhancement of a decay rate is observed, in agreement with the developed quantitative description of the Purcell effect in a nonlocal medium. An engineered material nonlocality introduces an additional degree of freedom into quantum electrodynamics, enabling new applications in quantum information processing, photo-chemistry, imaging, and sensing.

  8. Backward Propagation of Otoacoustic Emissions

    Institute of Scientific and Technical Information of China (English)

    HE Wenxuan; REN Tianying

    2006-01-01

    Normal mammalian ears not only detect but also generate sounds. The ear-generated sounds, I.e., otoacoustic emissions (OAEs), can be measured in the external ear canal using a tiny sensitive microphone. In spite of wide applications of OAEs in diagnosis of hearing disorders and in studies of cochlear functions, the question of how the cochlea emits sounds remains unclear. The current dominating theory is that the OAE reaches the cochlear base through a backward traveling wave. However, recently published works, including experimental data on the spatial pattern ofbasilar membrane vibrations at the emission frequency, demonstrated only forward traveling waves and no signs of backward traveling waves. These new findings indicate that the cochlea emits sounds through cochlear fluids as compression waves rather than through the basilar membrane as backward traveling waves. This article reviews different mechanisms of the backward propagation of OAEs and summarizes recent experimental results.

  9. Integrated Emissivity And Temperature Measurement

    Science.gov (United States)

    Poulsen, Peter

    2005-11-08

    A multi-channel spectrometer and a light source are used to measure both the emitted and the reflected light from a surface which is at an elevated temperature relative to its environment. In a first method, the temperature of the surface and emissivity in each wavelength is calculated from a knowledge of the spectrum and the measurement of the incident and reflected light. In the second method, the reflected light is measured from a reference surface having a known reflectivity and the same geometry as the surface of interest and the emitted and the reflected light are measured for the surface of interest. These measurements permit the computation of the emissivity in each channel of the spectrometer and the temperature of the surface of interest.

  10. Evaluation of Emissions Bio diesel

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Maroto, J. J.; Dorronsoro Arenal, J. L.; Rojas Garcia, E.; Perez Pastor, R.; Garcia Alonso, S.

    2007-09-27

    The generation of energy from vegetal products is one of the possibilities to our reach in order to reduce the atmospheric pollution. Particularly, the use of bio diesel in internal combustion engines can be one of the best options. The finest particles emitted by the combustion engines are easily breathable and on them different substances can be absorbed presumably toxic, between which it is possible to emphasize the polycyclic aromatic hydrocarbons (PAHs), by its demonstrated carcinogen character. In this work, it is studied on the one hand, the characteristics that can present the aerosol of emission in a diesel engine with a maximum power of 97 kW, working without load to 600 rpm, using as combustible mixtures of bio diesel and diesel in different proportions. On the other hand, the evolution that takes place in the concentration of PAHs in emission particles, according to the percentage of bio diesel used in the combustible mixture. (Author) 9 refs.

  11. Legislators Urge Carbon Emissions Cuts

    Science.gov (United States)

    Kumar, Mohi

    2007-02-01

    Legislators from the world's largest carbon dioxide (CO2) emitting countries met on 14-15 February in Washington, D.C., to discuss the future of the global climate and strategies to mitigate temperature increases resulting from global warming. The world faces a ``double challenge-how to reduce damaging carbon emissions while still meeting the energy demand that the world's poor need to escape poverty,'' said World Bank President Paul Wolfowitz during a keynote talk.

  12. Hot Electron Emission in Semiconductors.

    Science.gov (United States)

    2014-09-26

    absolute FIR emission intensity at one frequency as the absolute detector response and the optical properties of Present address: AT&T Bell Laboratories...awT)d.. (3) through the 2D electron system of GaAs/ AlGaAs single heterojunctions. This heats up the carriers to a carrier tern- The detector...this optical emis- and by the European Research Office of the U. S. Army, sion method are in good quantitative agreement with the London. Valuable

  13. An Instrument to Measure Aircraft Sulfate Particle Emissions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft particle emissions contribute a modest, but growing, portion of the overall particle emissions budget. Characterizing aircraft particle emissions is...

  14. Climate response: Strong warming at high emissions

    Science.gov (United States)

    Frölicher, Thomas L.

    2016-09-01

    The ratio of global temperature change to cumulative emissions is relatively constant up to two trillion tonnes of carbon emissions. Now a new modelling study suggests that the concept of a constant ratio is even applicable to higher cumulative carbon emissions, with important implications for future warming.

  15. 47 CFR 95.633 - Emission bandwidth.

    Science.gov (United States)

    2010-10-01

    ... SERVICES Technical Regulations Technical Standards § 95.633 Emission bandwidth. (a) The authorized... frequencies 151.820 MHz, 151.880 MHz, and 151.940 MHz are limited to 11.25 kHz. (2) Emissions on frequencies... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission bandwidth. 95.633 Section...

  16. 40 CFR 63.802 - Emission limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Emission limits. 63.802 Section 63.802... Standards for Wood Furniture Manufacturing Operations § 63.802 Emission limits. (a) Each owner or operator of an existing affected source subject to this subpart shall: (1) Limit VHAP emissions from...

  17. 47 CFR 24.133 - Emission limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Emission limits. 24.133 Section 24.133 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Narrowband PCS § 24.133 Emission limits. (a) The power of any emission shall be attenuated...

  18. ASSESSMENT OF THE CONTROLLABILITY OF CONDENSIBLE EMISSIONS

    Science.gov (United States)

    The report gives results of a study to gain insights into the condensible emissions area from an air toxics perspective, with emphasis on controllability and chemical composition of these emissions. he study compiled existing data on condensible emissions; determined the chemical...

  19. CHARACTERIZATION OF EMISSIONS FROM BURNING INCENSE

    Science.gov (United States)

    The primary objective of this study was to improve the characterization of particulate matter emissions from burning incense. Emissions of particulate matter were measured for 23 different types of incense using a cyclone/filter method. Emission rates for PM2.5 (particulate matte...

  20. 40 CFR 52.348 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Emission inventories. 52.348 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.348 Emission inventories. (a) The Governor of the State of Colorado submitted the 1990 carbon monoxide base year emission inventories for...

  1. 40 CFR 52.2309 - Emissions inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Emissions inventories. 52.2309 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Texas § 52.2309 Emissions inventories. (a) The Governor of the State of Texas submitted the 1990 base year emission inventories for the...

  2. 40 CFR 52.993 - Emissions inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Emissions inventories. 52.993 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Louisiana § 52.993 Emissions inventories. (a) The Governor of the State of Louisiana submitted the 1990 base year emission inventories for the Baton...

  3. 40 CFR 52.384 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Emission inventories. 52.384 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.384 Emission inventories. (a) The Governor's designee for the State of Connecticut submitted the 1990 base year emission inventories for...

  4. 40 CFR 52.2350 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Emission inventories. 52.2350 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Utah § 52.2350 Emission inventories. (a) The Governor of the State of Utah submitted the 1990 base year emission inventory of ozone precursors,...

  5. 40 CFR 52.1036 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Emission inventories. 52.1036 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maine § 52.1036 Emission inventories. (a) The Governor's designee for the State of Maine submitted 1990 base year emission inventories for the Knox...

  6. 40 CFR 52.1125 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Emission inventories. 52.1125 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Massachusetts § 52.1125 Emission inventories... emission inventories for the Springfield nonattainment area and the Massachusetts portion of the...

  7. 40 CFR 52.1391 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Emission inventories. 52.1391 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1391 Emission inventories. (a) The Governor of the State of Montana submitted the 1990 carbon monoxide base year emission...

  8. New Commitment Options: Compatibility with Emissions Trading

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This paper considers different options for quantitative greenhouse gas emission commitments from the standpoint of their technical compatibility with emissions trading. These are dynamic targets, binding targets with price caps, non-binding targets, sector-wide targets/mechanisms, action targets, allowances and endowments, and long-term permits. This paper considers these options from the standpoint of their compatibility with emissions trading.

  9. Annual Danish Emissions Inventory Report to UNECE

    DEFF Research Database (Denmark)

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

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

  10. Competitiveness and linking of emission trading systems

    Energy Technology Data Exchange (ETDEWEB)

    Hausotter, Tobias; Steuwer, Sibyl; Taenzler, Dennis [adelphi, Berlin (Germany)

    2011-01-15

    The establishment of emission trading systems raises concerns among industries regarding international competitive disadvantages for the industries under an emissions cap. This study aims to assess competitiveness exposure of industrial sectors and presents policy measures to address these concerns. Moreover, the study provides a comparison of different existing approaches to competitiveness concerns proposed by regional emission trading systems. (orig.)

  11. Review Existing and Proposed Emissions Trading Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This paper reviews key design features of mandatory emissions trading systems that had been established or were under consideration in 2010, with a particular focus on implications for the energy sector. Putting a price on greenhouse gas emissions is a cornerstone policy in climate change mitigation. To this end, many countries have implemented or are developing domestic emissions trading systems.

  12. Fugitive emissions from nanopowder manufacturing

    Science.gov (United States)

    Trompetter, W. J.; Ancelet, T.; Davy, P. K.; Kennedy, J.

    2016-07-01

    In response to health and safety questions and concerns regarding particulate matter emissions from equipment used for synthesizing NiFe and TiO2 nanopowders, a study was undertaken to assess their impact on the air quality inside and outside a laboratory where the manufacturing equipment is operated. Elemental concentrations determined by ion beam analysis (IBA) of air particulate matter (PM) samples collected hourly with a StreakerTM sampler were used to identify possible sources and estimate contributions from nanopowder production and other sources. The fugitive nanopowder emissions were the highest at the indoor sampling location when powders were being manufactured. Average fugitive emissions of 210 ng m-3 (1-h average) (maximum 2163 ng m-3 1-h average) represented 2 % (maximum 20 %) of the average PM collected (9359 ng m-3 1-h average). The measured NiFe alloy or TiO2 PM concentrations were much smaller than the 8-h time-weighted average (TWA) workplace exposure standards (WES) for these materials (≥1,000,000 ng m-3). Most PM was found to be from infiltrated outdoor ambient sources. This suggests that nanopowder production in the laboratory is not likely to have adverse health effects on individuals using the equipment, although further improvements can be made to further limit exposure.

  13. Low emissions combustor test facility

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, D.J.; Hadley, M.S.; Norton, T.S.

    1993-12-01

    The Morgantown Energy Technology Center (METC) is in the process of constructing a low emissions combustor test and research (LECTR) facility designed to support the development of low emissions gas turbine combustion systems fired on natural gas and coal derived gaseous fuels containing fuel bound nitrogen. The LECTR facility is a major test station located within METC`s new combustion facility. The heart of this test station is a 60 centimeter (24 inch) diameter, refractory lined pressure vessel made up of a series of flanged modules. The facility design offers the flexibility to test a variety of low emissions combustion concepts at pressures up to 3 MPa (30 atm). Upon completion of fabrication and shake-down testing in January of 1994, the facility will be available for use by industrial and university partners through Cooperative Research and Development Agreements (CRADAs) or through other cooperative arrangements. This paper is intended to describe the LECTR facility and associated operating parameter ranges and to inform interested parties of the facility availability.

  14. Trimethylamine emissions in animal husbandry

    Directory of Open Access Journals (Sweden)

    J. Sintermann

    2014-09-01

    Full Text Available Degradation of plant material by animals is an important transformation pathway in the nitrogen (N cycle. During the involved processes, volatile reduced alkaline nitrogen compounds, mainly ammonia (NH3 and aliphatic amines such as trimethylamine (TMA, are formed. Today, animal husbandry is estimated to constitute a main source of aliphatic amines in the atmosphere with TMA being the main emitted compound. Here, we show how the interaction between faeces and urine in animal production systems provides the primary source for agricultural TMA emissions. Excreted urine contains large quantities of urea and TMA-N-oxide, which are transformed into NH3 and TMA, respectively, via enzymatic processes provided by microbes present in faeces. TMA emissions from areas polluted with urine–faeces mixtures are on average of the order of 10 to 50 nmol m−2s−1. Released amines promote secondary aerosol particle formation in the agricultural emission plume. The atmospheric lifetime of TMA, which was estimated to be of the order of 30 to 1000 s, is determined by the condensation onto aerosol particles.

  15. Trimethylamine emissions in animal husbandry

    Directory of Open Access Journals (Sweden)

    J. Sintermann

    2014-05-01

    Full Text Available Degradation of plant material by animals is an important transformation pathway in the nitrogen (N cycle. During the involved processes, volatile reduced alkaline nitrogen compounds, mainly ammonia (NH3 and aliphatic amines such as trimethylamine (TMA, are formed. Today, animal husbandry is estimated to constitute a main source of aliphatic amines into the atmosphere with TMA being the main emitted compound. Here, we show how the interaction between faeces and urine in animal production systems provides the primary source for agricultural TMA emissions. Excreted urine contains large quantities of urea and TMA-N-oxide, which are transformed into NH3 and TMA, respectively, via enzymatic processes provided by microbes present in faeces. TMA emissions from areas polluted with urine-faeces mixture are on average in the order of 10 to 50 nmol m−2s−1. Released amines promote secondary aerosol particle formation in the agricultural emission plume. The atmospheric lifetime of TMA, which was estimated to be in the order of 30 to 1000 s, is determined by the condensation on aerosol particles.

  16. Trimethylamine emissions in animal husbandry

    Science.gov (United States)

    Sintermann, J.; Schallhart, S.; Kajos, M.; Jocher, M.; Bracher, A.; Münger, A.; Johnson, D.; Neftel, A.; Ruuskanen, T.

    2014-09-01

    Degradation of plant material by animals is an important transformation pathway in the nitrogen (N) cycle. During the involved processes, volatile reduced alkaline nitrogen compounds, mainly ammonia (NH3) and aliphatic amines such as trimethylamine (TMA), are formed. Today, animal husbandry is estimated to constitute a main source of aliphatic amines in the atmosphere with TMA being the main emitted compound. Here, we show how the interaction between faeces and urine in animal production systems provides the primary source for agricultural TMA emissions. Excreted urine contains large quantities of urea and TMA-N-oxide, which are transformed into NH3 and TMA, respectively, via enzymatic processes provided by microbes present in faeces. TMA emissions from areas polluted with urine-faeces mixtures are on average of the order of 10 to 50 nmol m-2s-1. Released amines promote secondary aerosol particle formation in the agricultural emission plume. The atmospheric lifetime of TMA, which was estimated to be of the order of 30 to 1000 s, is determined by the condensation onto aerosol particles.

  17. Trace element emissions from coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

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

  18. Robust multispectral transparency in continuous metal film structures via multiple near-field plasmon coupling by a finite-difference time-domain method.

    Science.gov (United States)

    Liu, Gui-qiang; Hu, Ying; Liu, Zheng-qi; Chen, Yuan-hao; Cai, Zheng-jie; Zhang, Xiang-nan; Huang, Kuan

    2014-03-07

    We propose a robust multispectral transparent plasmonic structure and calculate its transparency response by using the three-dimensional finite-difference time-domain (FDTD) method. The proposed structure is composed of a continuous ultrathin metal film sandwiched by double two-dimensional (2D) hexagonal non-close-packed metal-dielectric multilayer core-shell nanoparticle arrays. The top and bottom plasmonic arrays in such a structure, respectively, act as the light input and output couplers to carry out the efficient trapping and release of light. Near-perfect multispectral optical transparency in the visible and near-infrared regions is achieved theoretically. The calculated electric field distribution patterns show that the near-perfect multispectral optical transparency mainly originates from the excitation and hybridization of shell and core plasmon modes, strong near-field coupling of dipole plasmon modes between adjacent nanoparticles as well as the excitation of surface plasmon waves of the metal film. The robust transparency bands can be efficiently tuned in a large range by varying the structural parameters and the surrounding dielectric environment. The proposed structure also shows additional merits such as a deep sub-wavelength size and fully retained electrical and mechanical properties of the natural metal. These features might provide promising applications in highly integrated optoelectronic devices including plasmonic filters, nanoscale multiplexers, and non-linear optics.

  19. Effect of Surface Plasmon Coupling to Optical Cavity Modes on the Field Enhancement and Spectral Response of Dimer-Based sensors

    KAUST Repository

    Alrasheed, Salma

    2017-09-05

    We present a theoretical approach to narrow the plasmon linewidth and enhance the near-field intensity at a plasmonic dimer gap (hot spot) through coupling the electric localized surface plasmon (LSP) resonance of a silver hemispherical dimer with the resonant modes of a Fabry-Perot (FP) cavity. The strong coupling is demonstrated by the large anticrossing in the reflection spectra and a Rabi splitting of 76 meV. Up to 2-fold enhancement increase can be achieved compared to that without using the cavity. Such high field enhancement has potential applications in optics, including sensors and high resolution imaging devices. In addition, the resonance splitting allows for greater flexibility in using the same array at different wavelengths. We then further propose a practical design to realize such a device and include dimers of different shapes and materials.

  20. Use of Plasmon Coupling to Reveal the Dynamics of DNA Bending andCleavage by Single EcoRV Restriction Enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Reinhard, Bjorn; Sheikholeslami, Sassan; Mastroianni, Alexander; Alivisatos, A. Paul; Liphardt, Jan

    2006-09-06

    Pairs of Au nanoparticles have recently been proposed asplasmon rulers based on the dependence of their light scattering on theinterparticle distance. Preliminary work has suggested that plasmonrulers can be used to measure and monitor dynamic distance changes overthe 1 to 100nm length scale in biology. Here, we substantiate thatplasmon rulers can be used to effectively measure dynamical biophysicalprocesses by applying the ruler to a system that has been investigatedextensively using ensemble kinetic measurements: the cleavage of DNA bythe restriction enzyme EcoRV. Temporal resolutions of up to 240 Hz wereobtained, and the end-to-end extension of up to 1000 individual dsDNAenzyme substrates could be monitored in parallel for hours. The singlemolecule cleavage trajectories acquired here agree well with valuesobtained in bulk through other methods, and confirm well-known featuresof the cleavage process, such as the fact that the DNA is bent prior tocleavage. New dynamical information is revealed as well, for instance,the degree of softening of the DNA just prior to cleavage. The unlimitedlife time, high temporal resolution, and high signal/noise make theplasmon ruler an excellent tool for studying macromolecular assembliesand conformational changes at the single molecule level.

  1. Application of the emission inventory model TEAM: Uncertainties in dioxin emission estimates for central Europe

    NARCIS (Netherlands)

    Pulles, M.P.J.; Kok, H.; Quass, U.

    2006-01-01

    This study uses an improved emission inventory model to assess the uncertainties in emissions of dioxins and furans associated with both knowledge on the exact technologies and processes used, and with the uncertainties of both activity data and emission factors. The annual total emissions for the y

  2. Implications of diesel emissions control failures to emission factors and road transport NOx evolution

    Science.gov (United States)

    Ntziachristos, Leonidas; Papadimitriou, Giannis; Ligterink, Norbert; Hausberger, Stefan

    2016-09-01

    Diesel NOx emissions have been at the forefront of research and regulation scrutiny as a result of failures of late vehicle technologies to deliver on-road emissions reductions. The current study aims at identifying the actual emissions levels of late light duty vehicle technologies, including Euro 5 and Euro 6 ones. Mean NOx emission factor levels used in the most popular EU vehicle emission models (COPERT, HBEFA and VERSIT+) are compared with latest emission information collected in the laboratory over real-world driving cycles and on the road using portable emissions measurement systems (PEMS). The comparison shows that Euro 5 passenger car (PC) emission factors well reflect on road levels and that recently revealed emissions control failures do not call for any significant corrections. However Euro 5 light commercial vehicles (LCVs) and Euro 6 PCs in the 2014-2016 period exhibit on road emission levels twice as high as used in current models. Moreover, measured levels vary a lot for Euro 6 vehicles. Scenarios for future evolution of Euro 6 emission factors, reflecting different degree of effectiveness of emissions control regulations, show that total NOx emissions from diesel Euro 6 PC and LCV may correspond from 49% up to 83% of total road transport emissions in 2050. Unless upcoming and long term regulations make sure that light duty diesel NOx emissions are effectively addressed, this will have significant implications in meeting future air quality and national emissions ceilings targets.

  3. Five essays on emissions trading

    Energy Technology Data Exchange (ETDEWEB)

    Godal, Odd

    2005-03-01

    The thesis discusses energy, environmental and economic aspects of polluting emissions with emphasis on greenhouse gas trade and political measures. 5 papers are included with titles: 1) Carbon trading across sources and periods constrained by the Marrakesh Accords which examines examine the potential effects on permit prices and abatement costs of four compliance rules governing emissions trade across sources and periods in the Kyoto Protocol: The banking rule that allows excess permits to be used later; the restoration rate rule that penalizes borrowing; the commitment period reserve rule that limits sales; and finally, the suspension rule that restricts borrowing and sales. Our framework is a two-period model where parties may be out of compliance in the Kyoto period, but are assumed to comply at a later time. Under varying assumptions about market power and US participation, we find that the rules may have pronounced effects on individual costs, but overall efficiency is not severely affected. 2) Affine price expectations and equilibrium in strategic markets which considers equilibrium in imperfect markets, featuring agents who exchange property rights. Important cases include trade in emission permits of greenhouse gases, or exchange of catch quotas of fish. Some players act strategically while others are price-takers. The ''demand curve'' is endogenous, and it affects all parties. The resulting, reduced objectives need not be concave. Therefore, existence of equilibrium is a delicate matter. To simplify things, and to ensure availability of ''equilibria up to first order'', we presume that all strategic agents form affine price expectations. 3) Greenhouse gases, quota exchange and oligopolistic competition that discusses the problem how quotas can be shared in the ''emissions market'' and how can the agents reach as overall equilibrium in the product market. 4) Strategic markets in property rights

  4. Emission and transmission noise propagation in positron emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, G.T.; Huesman, R.H.

    1979-06-01

    Errors in positron emission computed tomograms are the result of noise propagated from three sources: (1) the statistical fluctuation in the positron coincidence events; (2) the statistical fluctuation in the incident transmission beam; and (3) the statistical fluctuation in the transmitted beam. The data for the transmission study in (2) and (3) are used to compensate for internal absorption of the distributed positron source. For the reconstruction of a circular phantom using the convolution algorithm, the percent root-mean-square uncertainty (%RMS) is related to the total measured positron events C and the incident photon flux per cm I/sub 0/. Our derivation of the %RMS uncertainty based on the propagation of errors yields a simple expression: %RMS = ..sqrt..K/sub 1//C + K/sub 2//I/sub 0/. The constants K/sub 1/ = 4.52 x 10/sup 8/ and K/sub 2/ = 1.48 x 10/sup 8/ were determined for a 20 cm diameter disc based on computer simulation. The projection data were analytically calculated with an attenuation coefficient ..mu.. = 0.0958 cm/sup -1/ for 140 angles between 0 and ..pi... Poisson noise was added to the positron coincidence events, the incident transmission events I/sub 0/, and the transmitted events. These results indicate that for a total number of incident transmission photons per cm of 2.0 x 10/sup 5/, the contrast resolution for a fixed spatial resolution is limited to 27% even with an infinite number of emission events. For a total of 10/sup 6/ emission events the contrast resolution is 34%.

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

    CERN Document Server

    Ysard, Nathalie

    2009-01-01

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

  6. Gunn effect in field-emission phenomena

    Science.gov (United States)

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

    2005-02-01

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

  7. Activation of silicon quantum dots for emission

    Institute of Scientific and Technical Information of China (English)

    Huang Wei-Qi; Miao Xin-Jian; Huang Zhong-Mei; Liu Shi-Rong; Qin Chao-Jian

    2012-01-01

    The emission of silicon quantum dots is weak when their surface is passivated well. Oxygen or nitrogen on the surface of silicon quantum dots can break the passivation to form localized electronic states in the band gap to generate active centers where stronger emission occurs.From this point of view,we can build up radiative matter for emission.Emissions of various wavelengths can be obtained by controlling the surface bonds of silicon quantum dots.Our experimental results demonstrate that annealing is important in the treatment of the activation,and stimulated emissions at about 600 and 700 nm take place on active silicon quantum dots.

  8. VLF emissions from ionospheric/magnetospheric plasma

    Indian Academy of Sciences (India)

    R P Patel; R P Singh

    2001-05-01

    VLF emissions such as hiss, chorus, oscillating tones, hiss-triggered chorus and whistler triggered emissions have been observed at low latitude Indian stations. In this paper we present dynamic spectra of these emissions and discuss their various observed features. It is argued that most of the emissions are generated during Doppler shifted cyclotron resonance interaction between the whistler mode wave and counter streaming energetic electrons. Resonance energy of the participating electron and interaction length are evaluated to explain the generation mechanism of some of these emissions observed at Indian stations.

  9. 2008 LANL radionuclide air emissions report

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David P.

    2009-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2008. This report meets the reporting requirements established in the regulations.

  10. 2009 LANL radionuclide air emissions report

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David P.

    2010-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2009. This report meets the reporting requirements established in the regulations.

  11. Marine Engines and Nitrogen Oxides Emissions

    Directory of Open Access Journals (Sweden)

    Corneliu Moroianu

    2008-10-01

    Full Text Available Current international policy initiatives by the International Maritime Organization (IMO to reduce emissions from ship propulsion systems (NOx and SOx, primarily mark the first efforts to define a framework to address this issue. Oxides of nitrogen (NOx emissions from ship engines are significant on a global level. NOx emissions participate in the formation of photochemical smog and acid rain. Marine sourced emissions have significant impact on air quality on land. The challenge is to control NOx emissions without increasing fuel consumption and smoke. Most engine manufacturers can meet the current IMO limits by engine tuning measures

  12. 2010 LANL radionuclide air emissions report /

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David P.

    2011-06-01

    The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2010. This report meets the reporting requirements established in the regulations.

  13. Air emissions inventory for the Idaho National Engineering Laboratory -- 1995 emissions report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    This report presents the 1995 update of the Air Emission Inventory for the Idaho National Engineering Laboratory (INEL). The INEL Air Emission Inventory documents sources and emissions of non-radionuclide pollutants from operations at the INEL. The report describes the emission inventory process and all of the sources at the INEL, and provides non-radionuclide emissions estimates for stationary sources. The air contaminants reported include nitrogen oxides, sulfur oxides, carbon monoxide, volatile organic compounds, particulates, and hazardous air pollutants (HAPs).

  14. Mitigating greenhouse gas emissions: Voluntary reporting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

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

  15. Estimation of vegetative mercury emissions in China

    Institute of Scientific and Technical Information of China (English)

    QUAN Jiannong; ZHANG Xiaoshan; Shang Gyoo SHIM

    2008-01-01

    Vegetative mercury emissions were estimated within the framework of Biogenic Emission Inventory System (BEIS3 V3.11). In this estimation, the 19 categories of U.S. Geological Survey landcover data were incorporated to generate the vegetation-specific mercury emissions in a 81-km Lambert Conformal model grid coveting the total Chinese continent. The surface temperature and cloud-corrected solar radiation from a Mesoscale Meteorological model (MMS) were retrieved and used for calculating the diurnal variation. The implemented emission factors were either evaluated from the measured mercury flux data for forest, agriculture and water, or assumed for other land fields without available flux data. Annual simulations using the MM5 data were performed to investigate the seasonal emission variation. From the sensitivity analysis using two sets of emission factors, the vegetative mercury emissions in China domain were estimated to range from a lower limit of 79×103 kg/year to an upper limit of 177×103 kg/year. The modeled vegetative emissions were mainly generated from the eastern and southern China. Using the estimated data, it is shown that mercury emissions from vegetation are comparable to that from anthropogenic sources during summer. However, the vegetative emissions decrease greatly during winter, leaving anthropogenic sources as the major sources of emission.

  16. Emission system upgrades for older vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, R.R.; Finkenbiner, K.; Sommerville, R.J.

    1996-09-01

    Thirteen 1975--1980 model year vehicles were equipped with a set of components to upgrade their emission control systems. Each vehicle was tested before maintenance (as-received), after tune-up and correction of original equipment emission system defects (baseline), and after installation of the emission upgrade system (upgrade). Average emissions of non-methane hydrocarbons (NHMC), carbon monoxide (CO), and nitrogen oxides (NOx) with the emission upgrade system installed were reduced more than 60% from the baseline immediately after upgrade. Six of the vehicles accumulated 48,000 kilometers with the upgrade system. After 48,000 kilometers, average emissions of NMHC and NOx were still reduced approximately 50% compared to the baseline and average emissions of CO were reduced approximately 20%.

  17. Greenhouse Gas Emissions from Agricultural Production

    DEFF Research Database (Denmark)

    Bennetzen, Eskild Hohlmann

    unit. This dissertation presents results and comprehensions from my PhD study on the basis of three papers. The overall aim has been to develop a new identity-based framework, the KPI, to estimate and analyse GHG emissions from agriculture and LUC and apply this on national, regional and global level....... The KPI enables combined analyses of changes in total emissions, emissions per area and emissions per product. Also, the KPI can be used to assess how a change in each GHG emission category affects the change in total emissions; thus pointing to where things are going well and where things are going less...... well in relation to what is actually produced. The KPI framework is scale independent and can be applied at any level from field and farm to global agricultural production. Paper I presents the first attempt to develop the KPI identity framework and, as a case study, GHG emissions from Danish crop...

  18. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

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

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

  19. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

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

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

  20. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

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

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

  1. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

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

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

  2. Soil emissivity and reflectance spectra measurements.

    Science.gov (United States)

    Sobrino, José A; Mattar, Cristian; Pardo, Pablo; Jiménez-Muñoz, Juan C; Hook, Simon J; Baldridge, Alice; Ibañez, Rafael

    2009-07-01

    We present an analysis of the laboratory reflectance and emissivity spectra of 11 soil samples collected on different field campaigns carried out over a diverse suite of test sites in Europe, North Africa, and South America from 2002 to 2008. Hemispherical reflectance spectra were measured from 2.0 to 14 microm with a Fourier transform infrared spectrometer, and x-ray diffraction analysis (XRD) was used to determine the mineralogical phases of the soil samples. Emissivity spectra were obtained from the hemispherical reflectance measurements using Kirchhoff's law and compared with in situ radiance measurements obtained with a CIMEL Electronique CE312-2 thermal radiometer and converted to emissivity using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) temperature and emissivity separation algorithm. The CIMEL has five narrow bands at approximately the same positions as the ASTER. Results show a root mean square error typically below 0.015 between laboratory emissivity measurements and emissivity measurements derived from the field radiometer.

  3. Greenhouse gas emissions intensity of global croplands

    Science.gov (United States)

    Carlson, Kimberly M.; Gerber, James S.; Mueller, Nathaniel D.; Herrero, Mario; MacDonald, Graham K.; Brauman, Kate A.; Havlik, Petr; O'Connell, Christine S.; Johnson, Justin A.; Saatchi, Sassan; West, Paul C.

    2017-01-01

    Stabilizing greenhouse gas (GHG) emissions from croplands as agricultural demand grows is a critical component of climate change mitigation. Emissions intensity metrics--including carbon dioxide equivalent emissions per kilocalorie produced (`production intensity’)--can highlight regions, management practices, and crops as potential foci for mitigation. Yet the spatial and crop-wise distribution of emissions intensity has been uncertain. Here, we develop global crop-specific circa 2000 estimates of GHG emissions and GHG intensity in high spatial detail, reporting the effects of rice paddy management, peatland draining, and nitrogen (N) fertilizer on CH4, CO2 and N2O emissions. Global mean production intensity is 0.16 Mg CO2e M kcal-1, yet certain cropping practices contribute disproportionately to emissions. Peatland drainage (3.7 Mg CO2e M kcal-1)--concentrated in Europe and Indonesia--accounts for 32% of these cropland emissions despite peatlands producing just 1.1% of total crop kilocalories. Methane emissions from rice (0.58 Mg CO2e M kcal-1), a crucial food staple supplying 15% of total crop kilocalories, contribute 48% of cropland emissions, with outsized production intensity in Vietnam. In contrast, N2O emissions from N fertilizer application (0.033 Mg CO2e M kcal-1) generate only 20% of cropland emissions. We find that current total GHG emissions are largely unrelated to production intensity across crops and countries. Climate mitigation policies should therefore be directed to locations where crops have both high emissions and high intensities.

  4. Dioxin emission of road traffic; Dioxin-Emission des Strassenverkehrs

    Energy Technology Data Exchange (ETDEWEB)

    Buehler, U. [Antriebstechnik Ferretti GmbH (Germany); Essers, U. [Stuttgart Univ. (Germany). Inst. fuer Verbrennungsmotoren und Kraftfahrwesen]|[Forschungsinstut fuer Kraftfahrwesen und Fahrzeugmotoren, Stuttgart (Germany).; Greiner, R. [Stuttgart Univ. (Germany). Inst. fuer Verbrennungsmotoren und Kraftfahrwesen

    1997-07-01

    The well-founded determination of the dioxin and furan emission (PXDD/PXDF) of road traffic was the aim of a research project jointly conducted by the Chair of Ecological Chemistry and Geochemistry at the University of Bayreuth (Prof. Hutzinger), the Institute for Organic Chemistry at the University of Tuebingen (Prof. Hagenmaier) and the IVK (Prof. Essers). The non-standardised examinations of an otto engine, a passenger car and a truck diesel engine required the development of sample-taking and analysis methods as well as of engine test technology. The otto engine driven with leaded gasoline containing scavengers showed the highest dioxin and furan emission while, on the other hand, the otto engine driven with unleaded gasoline, the diesel engines and in particular the otto engine with three-way catalytic converter showed much lower values. (orig.) [Deutsch] Die fundierte Ermittlung der Dioxin- und Furan-Emissionen (PXDD/PXDF) des Strassenverkehrs war das Ziel eines vom Lehrstuhl fuer Oekologische Chemie und Geochemie der Universitaet Bayreuth, dem Institut fuer Organische Chemie der Universitaet Tuebingen und dem IVK der Universitaet Stuttgart gemeinsam bearbeiteten Forschungsprojekts. Die nicht standardisierten Untersuchungen an einem Ottomotor, einem Pkw- und einem Lkw-Dieselmotor erforderten die Entwicklung von Probenahme- und Analyseverfahren sowie der motorischen Prueftechnik. Der mit verbleitem, scavengerhaltigem Benzin betriebene Ottomotor wies die hoechsten Dioxin- und Furanemissionen auf. Demgegenueber waren die Emissionen des mit unverbleitem Benzin betriebenen Ottomotors, der Dieselmotoren und besonders des Ottomotors mit Drei-Wege-Katalysator deutlich geringer. (orig.)

  5. Learning from global emissions scenarios

    Science.gov (United States)

    O'Neill, Brian C.; Nakicenovic, Nebojsa

    2008-10-01

    Scenarios of global greenhouse gas emissions have played a key role in climate change analysis for over twenty years. Currently, several research communities are organizing to undertake a new round of scenario development in the lead-up to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). To help inform this process, we assess a number of past efforts to develop and learn from sets of global greenhouse gas emissions scenarios. We conclude that while emissions scenario exercises have likely had substantial benefits for participating modeling teams and produced insights from individual models, learning from the exercises taken as a whole has been more limited. Model comparison exercises have typically focused on the production of large numbers of scenarios while investing little in assessing the results or the production process, perhaps on the assumption that later assessment efforts could play this role. However, much of this assessment potential remains untapped. Efforts such as scenario-related chapters of IPCC reports have been most informative when they have gone to extra lengths to carry out more specific comparison exercises, but in general these assessments do not have the remit or resources to carry out the kind of detailed analysis of scenario results necessary for drawing the most useful conclusions. We recommend that scenario comparison exercises build-in time and resources for assessing scenario results in more detail at the time when they are produced, that these exercises focus on more specific questions to improve the prospects for learning, and that additional scenario assessments are carried out separately from production exercises. We also discuss the obstacles to better assessment that might exist, and how they might be overcome. Finally, we recommend that future work include much greater emphasis on understanding how scenarios are actually used, as a guide to improving scenario production.

  6. Acoustic emission methodology and application

    CERN Document Server

    Nazarchuk, Zinoviy; Serhiyenko, Oleh

    2017-01-01

    This monograph analyses in detail the physical aspects of the elastic waves radiation during deformation or fracture of materials. I presents the  methodological bases for the practical use of acoustic emission device, and describes the results of theoretical and experimental researches of evaluation of the crack growth resistance of materials, selection of the useful AE signals. The efficiency of this methodology is shown through the diagnostics of various-purpose industrial objects. The authors obtain results of experimental researches with the help of the new methods and facilities.

  7. Secondary Emission Calorimeter Sensor Development

    Science.gov (United States)

    Winn, David R.; Onel, Yasar

    2012-12-01

    In a Secondary Emission electron(SEe) detector module, Secondary Emission electrons (SEe) are generated from an SE surface/cathode, when charged hadronic or electromagnetic particles, particularly shower particles, penetrate an SE sampling module placed between absorber materials (Fe, Cu, Pb, W etc) in calorimeters. The SE cathode is a thin (10-50 nm thick) film (simple metal-oxides, or other higher yield materials) on the surface of a metal plate, which serves as the entrance “window” to a compact vacuum vessel (metal or metal-ceramic); this SE film cathode is analogous to a photocathode, and the SEe are similar to p.e., which are then amplified by dynodes, also is in a PMT. SE sensor modules can make use of electrochemically etched/machined or laser-cut metal mesh dynode sheets, as large as ~30 cm square, to amplify the Secondary Emission Electrons (SEe), much like those that compact metal mesh or mesh dynode PMT's use to amplify p.e.'s. The construction requirements easier than a PMT, since the entire final assembly can be done in air; there are no critical controlled thin film depositions, cesiation or other oxygen-excluded processes or other required vacuum activation, and consequently bake-out can be a refractory temperatures; the module is sealed by normal vacuum techniques (welding or brazing or other high temperature joinings), with a simple final heated vacuum pump-out and tip-off. The modules envisioned are compact, high gain, high speed, exceptionally radiation damage resistant, rugged, and cost effective, and can be fabricated in arbitrary tileable shapes. The SE sensor module anodes can be segmented transversely to sizes appropriate to reconstruct electromagnetic cores with high precision. The GEANT4 and existing calorimeter data estimated calorimeter response performance is between 35-50 Secondary Emission electrons per GeV, in a 1 cm thick Cu absorber calorimeter, with a gain per SEe > 105 per SEe, and an e/pi<1.2. The calorimeter pulse width is

  8. The Emissions Gap Report 2015

    DEFF Research Database (Denmark)

    Following the historic signing of the 2030 Agenda for Sustainable Development, this sixth edition of the UNEP Emissions Gap Report comes as world leaders start gathering in Paris to establish a new agreement on climate change. The report offers an independent assessment of the mitigation contribu...... temperature increases on track to stay below 2°C by the end of the century; it provides data for an aspirational target of keeping that increase below 1.5°C; and it evaluates the INDCs in relation to progress on the 2020 pledges made in Cancun....

  9. Spontaneous emission of heavy clusters

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N.; Ivascu, M. (Central Inst. of Physics, Bucharest (Romania)); Sandulescu, A. (Joint Inst. for Nuclear Research, Dubna (USSR)); Greiner, W. (Frankfurt Univ. (Germany, F.R.))

    1984-08-01

    The lifetimes of some heavy nuclei relative to the spontaneous emission of various clusters heavier than the alpha particle are estimated with a model extended from the fission theory of alpha decay, showing that this phenomenon is a new manifestation of the nuclear shell structure. A greater probability is obtained for parent-heavy-cluster combinations leading to a magic or almost magic daughter nucleus. The analytical formula obtained allows the handling of a large number of cases to search for new kinds of radioactivities.

  10. Secondary emission monitor (SEM) grids.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    A great variety of Secondary Emission Monitors (SEM) are used all over the PS Complex. At other accelerators they are also called wire-grids, harps, etc. They are used to measure beam density profiles (from which beam size and emittance can be derived) in single-pass locations (not on circulating beams). Top left: two individual wire-planes. Top right: a combination of a horizontal and a vertical wire plane. Bottom left: a ribbon grid in its frame, with connecting wires. Bottom right: a SEM-grid with its insertion/retraction mechanism.

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

    Science.gov (United States)

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

    2011-11-15

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

  12. Evaluating Bay Area Methane Emission Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jeong, Seongeun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-03-01

    As a regulatory agency, evaluating and improving estimates of methane (CH4) emissions from the San Francisco Bay Area is an area of interest to the Bay Area Air Quality Management District (BAAQMD). Currently, regional, state, and federal agencies generally estimate methane emissions using bottom-up inventory methods that rely on a combination of activity data, emission factors, biogeochemical models and other information. Recent atmospheric top-down measurement estimates of methane emissions for the US as a whole (e.g., Miller et al., 2013) and in California (e.g., Jeong et al., 2013; Peischl et al., 2013) have shown inventories underestimate total methane emissions by ~ 50% in many areas of California, including the SF Bay Area (Fairley and Fischer, 2015). The goal of this research is to provide information to help improve methane emission estimates for the San Francisco Bay Area. The research effort builds upon our previous work that produced methane emission maps for each of the major source sectors as part of the California Greenhouse Gas Emissions Measurement (CALGEM) project (http://calgem.lbl.gov/prior_emission.html; Jeong et al., 2012; Jeong et al., 2013; Jeong et al., 2014). Working with BAAQMD, we evaluate the existing inventory in light of recently published literature and revise the CALGEM CH4 emission maps to provide better specificity for BAAQMD. We also suggest further research that will improve emission estimates. To accomplish the goals, we reviewed the current BAAQMD inventory, and compared its method with those from the state inventory from the California Air Resources Board (CARB), the CALGEM inventory, and recent published literature. We also updated activity data (e.g., livestock statistics) to reflect recent changes and to better represent spatial information. Then, we produced spatially explicit CH4 emission estimates on the 1-km modeling grid used by BAAQMD. We present the detailed activity data, methods and derived emission maps by sector

  13. Dioxin air emission inventory 1990-2004

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-15

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

  14. Emissions of Greenhouse gases in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Evers, C.W.A. [Ministry of Housing, The Hague (Netherlands). Inspectorate for Environmental Protection; Berdowski, J.J.M.; Pulles, T.P.J. [TNO Inst. for Environmental Sciences, Delft (Netherlands)

    1995-12-31

    The Dutch emission inventory system enables the registration, analysis and localization of emission data of both industrial and non-industrial sources in the Netherlands. The results can be used to test the effectiveness of governmental environmental policy. These activities are part of the policy evaluation tasks of the Inspectorate General for Environmental Protection (IGEP) and of the Ministry of Transport, Public Works and Water Management. The emission inventory takes place in cycles of one year. Recently, the most relevant results of the Dutch emission inventory for 1992 have been published. In that cycle the emissions in 1992 to air and water from about 800 major companies have been registered. These 800 companies are the most important contributors to the total industrial emissions in the Netherlands. The emissions of these companies are registered within the individual inventory system. The emissions from the smaller enterprises and from diffuse non-industrial sources are stored in the collective emission inventory system. The data collected in the 1992 inventory have been established for the first time in close cooperation between the IGEP, TNO, the Central Bureau of Statistics and the National Institute of Public Health and Environmental Protection. This implies that the data presented here have to be considered as the official data for the emissions in the Netherlands for the year 1992. (author)

  15. Global biogeochemical modeling of contemporary fire emissions

    Science.gov (United States)

    Randerson, J. T.; Depaz, J. M.; van der Werf, G. R.; Giglio, L.; Morton, D. C.; Kasibhatla, P.; Defries, R. S.; Jin, Y.; Mu, M.; Collatz, G. J.

    2008-12-01

    Improved estimates of contemporary fire emissions are needed to better understand the effects of a changing fire regime on climate and air quality. At a global scale, uncertainties in fire emissions arise from several sources, including estimates of burned area, aboveground biomass, combustion completeness, and emission factors. The development of long-term time series requires addressing additional sources of uncertainty related to the integration of different satellite fire products, the representation of organic soils and peatlands, and the use of fire in the deforestation process. Here we describe improvements to a global fire emissions time series (Global Fire Emissions Database version 3) that reduce uncertainties associated with many of the factors described above. We then characterized long-term trends in fire emissions for different continental-scale regions during 1996-2007. Using South America as an example, we show how climate and human activity contribute to interannual variability in emissions and how the spatial pattern of emissions has changed over time. In a final step we use atmospheric observations of carbon monoxide (CO) from Measurements Of Pollution In The Troposphere (MOPITT) and Tropospheric Emission Spectrometer (TES) to refine and validate our bottom-up emissions estimates for South America.

  16. Analysis of emissions from prebunched electron beams

    Directory of Open Access Journals (Sweden)

    Jia Qika

    2017-07-01

    Full Text Available The emissions of the prebunched electron beam, including the coherent spontaneous emission and the self-amplified stimulated emission, are analyzed by using one-dimensional FEL theory. Neglecting the interaction of the electrons and the radiation field, the formula of the coherent spontaneous emission is given, the power of which is proportional to the square of the initial bunching factor and of the undulator length. For the general emission case of the prebunched electron beam, the evolution equation of the optical field is deducted. Then the analytical expression of the emission power is obtained for the resonant case; it is applicable to the regions from the low gain to the high gain. It is found that when the undulator length is shorter than four gain lengths, the emission is just the coherent spontaneous emission, and conversely, it is the self-amplified stimulated emission growing exponentially. For the nonresonant prebunched electron beam, the variations of the emission intensity with the detuning parameter for different interaction length are presented. The radiation field characters of the prebunched electron beam are discussed and compared with that of the seeded FEL amplifier.

  17. Analysis of emissions from prebunched electron beams

    Science.gov (United States)

    Jia, Qika

    2017-07-01

    The emissions of the prebunched electron beam, including the coherent spontaneous emission and the self-amplified stimulated emission, are analyzed by using one-dimensional FEL theory. Neglecting the interaction of the electrons and the radiation field, the formula of the coherent spontaneous emission is given, the power of which is proportional to the square of the initial bunching factor and of the undulator length. For the general emission case of the prebunched electron beam, the evolution equation of the optical field is deducted. Then the analytical expression of the emission power is obtained for the resonant case; it is applicable to the regions from the low gain to the high gain. It is found that when the undulator length is shorter than four gain lengths, the emission is just the coherent spontaneous emission, and conversely, it is the self-amplified stimulated emission growing exponentially. For the nonresonant prebunched electron beam, the variations of the emission intensity with the detuning parameter for different interaction length are presented. The radiation field characters of the prebunched electron beam are discussed and compared with that of the seeded FEL amplifier.

  18. Contributions to motor vehicle emissions analysis

    Science.gov (United States)

    Pokharel, Sajal Sharma

    While motor vehicles are a major source of atmospheric pollutants, their in-use emissions remain inadequately characterized. Remote sensing devices (RSD) have been shown to be efficient tools for measuring CO, HC and NO in on-road vehicle exhaust. This work utilizes RSD data to illuminate new phenomena related to automobile emissions. Model year averaged RSD data are shown to correlate extremely well with IM240 measurements. IM240 is a loaded-mode dynamometer test used by several states as part of their emissions reduction strategy. The high degree of correlation helps to validate remote sensing as an instrument for IM240 evaluation. Such evaluations of programs in Chicago and Denver indicate an Inspection and Maintenance benefit of less than 10%. Fleet average on-road emissions have continually decreased over several years of measurement at the same locations in four U.S. cities: Chicago, Denver, Los Angeles and Phoenix. Together with the decrease in overall emissions, the distribution has become even more skewed. Fewer automobiles are responsible for a larger fraction of the decreasing total pollutant emissions. Analysis of the newest model year vehicles year after year at the four locations indicates that successive model years have become lower emitting. It is believed that more stringent government mandated emission standards and continuous improvement in the ability of automobile manufacturers to meet these standards is responsible for the emissions reductions. Comparison of emissions among the four cities, adjusted for load and model year, indicates that older vehicles in the Los Angeles area have higher CO and lower NO emissions. The fact that California had more stringent NO emission standards and more lenient CO ones compared to the rest of the states suggests, once again, the significant benefits of emission standards and new vehicle emission control technology.

  19. Flare emission from Sagittarius A*

    CERN Document Server

    Eckart, A; Vogel, S N; Teuben, P; Morris, M R; Baganoff, F; Dexter, J; Schoedel, R; Witzel, G; Valencia-S., M; Karas, V; Kunneriath, D; Bremer, M; Straubmeier, C; Moser, L; Sabha, N; Buchholz, R; Zamaninasab, M; Muzic, K; Moultaka, J; Zensus, J A

    2012-01-01

    Based on Bremer et al. (2011) and Eckart et al. (2012) we report on simultaneous observations and modeling of the millimeter, near-infrared, and X-ray flare emission of the source Sagittarius A* (SgrA*) associated with the super-massive black hole at the Galactic Center. We study physical processes giving rise to the variable emission of SgrA* from the radio to the X-ray domain. To explain the statistics of the observed variability of the (sub-)mm spectrum of SgrA*, we use a sample of simultaneous NIR/X-ray flare peaks and model the flares using a synchrotron and SSC mechanism. The observations reveal flaring activity in all wavelength bands that can be modeled as the signal from adiabatically expanding synchrotron self-Compton (SSC) components. The model parameters suggest that either the adiabatically expanding source components have a bulk motion larger than v_exp or the expanding material contributes to a corona or disk, confined to the immediate surroundings of SgrA*. For the bulk of the synchrotron and ...

  20. Greenhouse Gas Emissions From Cattle

    Directory of Open Access Journals (Sweden)

    Podkówka Zbigniew

    2015-03-01

    Full Text Available Cattle produce greenhouse gases (GHG which lead to changes in the chemical composition of the atmosphere. These gases which cause greenhouse effect include: methane (CH4, nitrous oxide (N2O, nitrogen oxides (NOx, sulphur dioxide (SO2, ammonia (NH3, dust particles and non-methane volatile organic compounds, commonly described as other than methane hydrocarbons. Fermentation processes taking place in the digestive tract produce ‘digestive gases’, distinguished from gases which are emitted during the decomposition of manure. Among these digestive gases methane and non-methane volatile organic compounds are of particular relevance importance. The amount of gases produced by cows can be reduced by choosing to rear animals with an improved genetically based performance. A dairy cow with higher production efficiency, producing milk with higher protein content and at the same time reduced fat content emits less GHG into the environment. Increasing the ratio of feed mixtures in a feed ration also reduces GHG emissions, especially of methane. By selection of dairy cows with higher production efficiency and appropriate nutrition, the farm's expected milk production target can be achieved while at the same time, the size of the herd is reduced, leading to a reduction of GHG emissions.

  1. Research priorities for negative emissions

    Science.gov (United States)

    Fuss, S.; Jones, C. D.; Kraxner, F.; Peters, G. P.; Smith, P.; Tavoni, M.; van Vuuren, D. P.; Canadell, J. G.; Jackson, R. B.; Milne, J.; Moreira, J. R.; Nakicenovic, N.; Sharifi, A.; Yamagata, Y.

    2016-11-01

    Carbon dioxide removal from the atmosphere (CDR)—also known as ‘negative emissions’—features prominently in most 2 °C scenarios and has been under increased scrutiny by scientists, citizens, and policymakers. Critics argue that ‘negative emission technologies’ (NETs) are insufficiently mature to rely on them for climate stabilization. Some even argue that 2 °C is no longer feasible or might have unacceptable social and environmental costs. Nonetheless, the Paris Agreement endorsed an aspirational goal of limiting global warming to even lower levels, arguing that climate impacts—especially for vulnerable nations such as small island states—will be unacceptably severe in a 2 °C world. While there are few pathways to 2 °C that do not rely on negative emissions, 1.5 °C scenarios are barely conceivable without them. Building on previous assessments of NETs, we identify some urgent research needs to provide a more complete picture for reaching ambitious climate targets, and the role that NETs can play in reaching them.

  2. Directional spectral emissivity measurement system

    Science.gov (United States)

    Halyo, Nesim (Inventor); Pandey, Dhirendra K. (Inventor)

    1992-01-01

    Apparatus and process for determining the emissivity of a test specimen including an integrated sphere having two concentric walls with a coolant circulating therebetween, and disposed within a chamber which may be under ambient, vacuum or inert gas conditions. A reference sample is disposed within the sphere with a monochromatic light source in optical alignment therewith. A pyrometer is in optical alignment with the test sample for obtaining continuous test sample temperature measurements during a test. An arcuate slit port is provided through the spaced concentric walls of the integrating sphere with a movable monochromatic light source extending through and movable along the arcuate slit port. A detector system extends through the integrating sphere for continuously detecting an integrated signal indicative of all radiation within its field of view, as a function of the emissivity of the test specimen at various temperatures and various angle position of the monochromatic light source. A furnace for heating the test sample to approximately 3000 K. and control mechanism for transferring the heated sample from the furnace to the test sample port in the integrating sphere is also contained within the chamber.

  3. Reducing ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2011-01-01

    Danish application procedure, when increasing the animal production, has tried to make the acceptance procedure quicker and dynamic ensuring that new technology is adopted quicker and that the farm is located in the right place. It is concluded that the new application process so far has not lived up......The NEC directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the largest reductions since 1990...... and the article looks at the measures and costs involved. The conclusion is that the costs have been under 3 €/kg NH3-N. The findings suggest that the same measures might be cheaper in the Netherlands and Denmark than in the UK and the USA due to technology advances and stricter regulations in the past. The new...

  4. Energetic particle emission: preequilibrium emission and cooperative effects

    Energy Technology Data Exchange (ETDEWEB)

    Sapienza, P.; Coniglione, R.; Colonna, M.; Migneco, E.; Agodi, C.; Alba, R.; Bellia, G.; Zoppo, A. Del; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Piattelli, P.; Santonocito, D. [INFN Lab. Nazionale del Sud, Via A. Doria 44, Catania (Italy); Colonna, N. [INFN, Bari (Italy); Bruno, M.; D Agostino, M.; Mastinu, P.F. [INFN and Dipartimento di Fisica, Bologna (Italy); Gramegna, F. [INFN Laboratorio Nazionale di Legnaro, Padova (Italy); Iori, I.; Fabbietti, L.; Moroni, A. [INFN and Dipartimento di Fisica, Milano (Italy); Margagliotti, G.V.; Milazzo, P.M.; Rui, R.; Vannini, G. [INFN and Dipartimento di Fisica, Trieste (Italy); Blumenfeld, Y.; Scarpaci, J.A. [Institut de Physique Nucleaire, IN2P3CNRS, F91406 Orsay (France)

    2001-09-01

    Full text: The {sup 58} Ni +{sup 58} Ni reaction at 30 A MeV was investigated at Laboratori Nazionale del Sud with the MEDEA and MULTICS apparatus. Energetic protons were detected in coincidence with photons, light charged particles (Z = 1, 2) (LCP) and intermediate and heavy fragments on an event by event basis. Protons with energy extending up to almost 20% of the total available energy, namely much larger than expected by coupling the relative motion with a sharp nucleon Fermi momentum distribution (kinematical limit), were measured in our experiment. We have also investigated the average proton multiplicity as a function of the number of participating nucleons A{sub part} (b) and a striking behavior with increasing energy is found. Indeed, the experimental proton multiplicity (full squares) displays the expected linear dependence on A{sub part} (b) for energy close to the kinematical limit (60 {<=} Ep {<=} 80 MeV), while the multiplicity of extremely energetic protons (130 {<=} Ep {<=} 150 MeV) exhibits an almost quadratic increase with A{sub part}. The comparison with BNV calculations which include the momentum dependence in the effective potential shows that the features of the energetic proton emission are well reproduced up to {approx_equal} 110 MeV while this approach fails to explain the almost quadratic dependence on the number of participant nucleons of the yield of very energetic protons (E{sub p}{sup NN} {>=} 130 MeV). So, the observed behavior calls for the introduction of mechanisms beyond the mean field and two body nucleon-nucleon collisions such as cooperative effects. In conclusions, these results shed some light on the emission of extremely energetic protons and can improve the understanding of the mechanism responsible for deep subthreshold particle production. Moreover, the detailed comparison with dynamical calculations allows to get a deeper insight on the first non equilibrated stage of the reaction where the highest temperatures and

  5. Quantification of methane emissions from danish landfills

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Mønster, Jacob; Kjeldsen, Peter

    2013-01-01

    Whole-landfill methane emission was quantified using a tracer technique that combines controlled tracer gas release from the landfill with time-resolved concentration measurements downwind of the landfill using a mobile high-resolution analytical instrument. Methane emissions from 13 Danish...... landfills varied between 2.6 and 60.8 kg CH4 h–1. The highest methane emission was measured at the largest (in terms of disposed waste amounts) of the 13 landfills, whereas the lowest methane emissions (2.6-6.1 kgCH4 h–1) were measured at the older and smaller landfills. At two of the sites, which had gas...... collection, emission measurements showed that the gas collection systems only collected between 30-50% of the methane produced (assuming that the produced methane equalled the sum of the emitted methane and the collected methane). Significant methane emissions were observed from disposed shredder waste...

  6. Anthropogenic sulfur dioxide emissions: 1850–2005

    Directory of Open Access Journals (Sweden)

    S. J. Smith

    2011-02-01

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

  7. Probing Field Emission from Boron Carbide Nanowires

    Institute of Scientific and Technical Information of China (English)

    TIAN Ji-Fa; GAO Hong-Jun; BAO Li-Hong; WANG Xing-Jun; HUI Chao; LIU Fei; LI Chen; SHEN Cheng-Min; WANG Zong-Li; GU Chang-Zhi

    2008-01-01

    High density boron carbide nanowires are grown by an improved carbon thermal reduction technique. Transmission electron microscopy and electron energy lose spectroscopy of the sample show that the synthesized nanowires are B4 C with good crystallization. The field emission measurement for an individual boron nanowire is performed by using a Pt tip installed in the focused ion beam system. A field emission current with enhancement factor of 106 is observed and the evolution process during emission is also carefully studied. Furthermore, a two-step field emission with stable emission current density is found from the high-density nanowire film. Our results together suggest that boron carbide nanowires are promising candidates for electron emission nanodevices.

  8. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, M.; Illerup, J. B.

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

  9. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, M.; Illerup, J. B.

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

  10. Greenhouse Gas Emissions from Agricultural Production

    DEFF Research Database (Denmark)

    Bennetzen, Eskild Hohlmann

    at critical issues towards reducing our climate footprints. A logical next step for developing the concept of identities regarding food production could be to integrate this production-based framework with identities on consumption and economic development. It must be a scientific goal to illustrate how we...... unit. This dissertation presents results and comprehensions from my PhD study on the basis of three papers. The overall aim has been to develop a new identity-based framework, the KPI, to estimate and analyse GHG emissions from agriculture and LUC and apply this on national, regional and global level....... The KPI enables combined analyses of changes in total emissions, emissions per area and emissions per product. Also, the KPI can be used to assess how a change in each GHG emission category affects the change in total emissions; thus pointing to where things are going well and where things are going less...

  11. Electron Impact Induced VUV Emission from Argon

    Science.gov (United States)

    Young, J. A.; Malone, C. P.; Johnson, P. V.

    2011-10-01

    Emission intensity and spectra are important tools for diagnosing plasma properties such as electron temperature and neutral density. In order to properly interpret emissions from low-density plasmas, accurate cross sections are needed, particularly low energy electron-impact cross sections. Of interest are the cross sections for Argon, a common species used in industrial and lighting applications. In this paper, we present recent measurements of electron-impact induced VUV emissions from Ar using a magnetically collimated monoenergetic beam of electrons and a 0.2m spectrometer. Specifically, we present emission excitation functions for both Ar I(1048 Å) and Ar I(1066 Å) emissions. Similarities and differences between current results and previously published emission results will be discussed. Also discussed will be the relation to recent electron energy loss results.

  12. Quantification of acetone emission from pine plants

    Institute of Scientific and Technical Information of China (English)

    SHAO; Min; (邵敏); Jürgen; Wildt

    2002-01-01

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

  13. Continental anthropogenic primary particle number emissions

    Science.gov (United States)

    Paasonen, Pauli; Kupiainen, Kaarle; Klimont, Zbigniew; Visschedijk, Antoon; Denier van der Gon, Hugo A. C.; Amann, Markus

    2016-06-01

    Atmospheric aerosol particle number concentrations impact our climate and health in ways different from those of aerosol mass concentrations. However, the global, current and future anthropogenic particle number emissions and their size distributions are so far poorly known. In this article, we present the implementation of particle number emission factors and the related size distributions in the GAINS (Greenhouse Gas-Air Pollution Interactions and Synergies) model. This implementation allows for global estimates of particle number emissions under different future scenarios, consistent with emissions of other pollutants and greenhouse gases. In addition to determining the general particulate number emissions, we also describe a method to estimate the number size distributions of the emitted black carbon particles. The first results show that the sources dominating the particle number emissions are different to those dominating the mass emissions. The major global number source is road traffic, followed by residential combustion of biofuels and coal (especially in China, India and Africa), coke production (Russia and China), and industrial combustion and processes. The size distributions of emitted particles differ across the world, depending on the main sources: in regions dominated by traffic and industry, the number size distribution of emissions peaks in diameters range from 20 to 50 nm, whereas in regions with intensive biofuel combustion and/or agricultural waste burning, the emissions of particles with diameters around 100 nm are dominant. In the baseline (current legislation) scenario, the particle number emissions in Europe, Northern and Southern Americas, Australia, and China decrease until 2030, whereas especially for India, a strong increase is estimated. The results of this study provide input for modelling of the future changes in aerosol-cloud interactions as well as particle number related adverse health effects, e.g. in response to tightening

  14. Correlating Engine NOx Emission with Biodiesel Composition

    Science.gov (United States)

    Jeyaseelan, Thangaraja; Mehta, Pramod Shankar

    2016-06-01

    Biodiesel composition comprising of saturated and unsaturated fatty acid methyl esters has a significant influence on its properties and hence the engine performance and emission characteristics. This paper proposes a comprehensive approach for composition-property-NOx emission analysis for biodiesel fuels and highlights the pathways responsible for such a relationship. Finally, a procedure and a predictor equation are developed for the assessment of biodiesel NOx emission from its composition details.

  15. Linking GHG Emission Trading Systems and Markets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Several different types of links are possible between different GHG-mitigation systems. These include: Linking two or more emission trading schemes so that emissions trading can occur both within and between different schemes ('direct links'); and Linking emission trading systems to registries/mechanisms and systems that generate offsets from project based mechanisms or from direct purchases/transfers of AAUs ('indirect links').

  16. Phosphors for flat panel emissive displays

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.T.; Walko, R.J.; Phillips, M.L.F.

    1995-07-01

    An overview of emissive display technologies is presented. Display types briefly described include: cathode ray tubes (CRTs), field emission displays (FEDs), electroluminescent displays (ELDs), and plasma display panels (PDPs). The critical role of phosphors in further development of the latter three flat panel emissive display technologies is outlined. The need for stable, efficient red, green, and blue phosphors for RGB fall color displays is emphasized.

  17. Determinants and predictability of global wildfire emissions

    Directory of Open Access Journals (Sweden)

    W. Knorr

    2012-08-01

    Full Text Available Biomass burning is one of the largest sources of atmospheric trace gases and aerosols globally. These emissions have a major impact on the radiative balance of the atmosphere and on air quality, and are thus of significant scientific and societal interest. Several datasets have been developed that quantify those emissions on a global grid and offered to the atmospheric modelling community. However, no study has yet attempted to systematically quantify the dependence of the inferred pyrogenic emissions on underlying assumptions and input data. Such a sensitivity study is needed for understanding how well we can currently model those emissions and what the factors are that contribute to uncertainties in those emission estimates.

    Here, we combine various satellite-derived burned area products, a terrestrial ecosystem model to simulate fuel loads and the effect of fire on ecosystem dynamics, a model of fuel combustion, and various emission models that relate combusted biomass to the emission of various trace gases and aerosols. We carry out simulations with varying parameters for combustion completeness and fuel decomposition rates within published estimates, four different emissions models and three different global burned-area products. We find that variations in combustion completeness and simulated fuel loads have the largest impact on simulated global emissions for most species, except for some with highly uncertain emission factors. Variation in burned-area estimates also contribute considerably to emission uncertainties. We conclude that global models urgently need more field-based data for better parameterisation of combustion completeness and validation of simulated fuel loads, and that further validation and improvement of burned area information is necessary for accurately modelling global wildfire emissions. The results are important for chemical transport modelling studies, and for simulations of biomass burning impacts on the

  18. Stimulated emission of surface plasmon polaritons

    CERN Document Server

    Noginov, M A; Mayy, M F; Ritzo, B A; Noginova, N; Podolskiy, V A

    2008-01-01

    We have observed laser-like emission of surface plasmon polaritons (SPPs) decoupled to the glass prism in an attenuated total reflection setup. SPPs were excited by optically pumped molecules in a polymeric film deposited on the top of the silver film. Stimulated emission was characterized by a distinct threshold in the input-output dependence and narrowing of the emission spectrum. The observed stimulated emission and corresponding to it compensation of the metallic absorption loss by gain enables many applications of metamaterials and nanoplasmonic devices.

  19. OPIC Greenhouse Gas Emissions Analysis Details

    Data.gov (United States)

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

  20. ARCADE 2 Observations of Galactic Radio Emission

    CERN Document Server

    Kogut, A; Levin, S M; Limon, M; Lubin, P M; Mirel, P; Seiffert, M; Singal, J; Villela, T; Wollack, E; Wünsche, C A

    2009-01-01

    We use absolutely calibrated data from the ARCADE 2 flight in July 2006 to model Galactic emission at frequencies 3, 8, and 10 GHz. The spatial structure in the data is consistent with a superposition of free-free and synchrotron emission. Emission with spatial morphology traced by the Haslam 408 MHz survey has spectral index beta_synch = -2.5 +/- 0.1, with free-free emission contributing 0.10 +/- 0.01 of the total Galactic plane emission in the lowest ARCADE 2 band at 3.15 GHz. We estimate the total Galactic emission toward the polar caps using either a simple plane-parallel model with csc|b| dependence or a model of high-latitude radio emission traced by the COBE/FIRAS map of CII emission. Both methods are consistent with a single power-law over the frequency range 22 MHz to 10 GHz, with total Galactic emission towards the north polar cap T_Gal = 0.498 +/- 0.028 K and spectral index beta = -2.55 +/- 0.03 at reference frequency 1 GHz. The well calibrated ARCADE 2 maps provide a new test for spinning dust emi...

  1. Emissivity Measurements of Additively Manufactured Materials

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Robert Vaughn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reid, Robert Stowers [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baker, Andrew M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lucero, Briana [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bernardin, John David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-25

    The emissivity of common 3D printing materials such as ABS and PLA were measured using a reflectivity meter and have the measured value of approximately 0.92. Adding a conductive material to the filament appears to cause a decrease in the emissivity of the surface. The angular dependence of the emissivity and the apparent temperature was measured using a FLIR infrared camera showing that the emissivity does not change much for shallow angles less than 40 angular degrees, and drops off dramatically after 70 angular degrees.

  2. The carbon emissions of Chinese cities

    Directory of Open Access Journals (Sweden)

    H. Wang

    2012-03-01

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

  3. Mercury emission from crematories in Japan

    Directory of Open Access Journals (Sweden)

    M. Takaoka

    2010-04-01

    Full Text Available Anthropogenic sources of mercury emissions have a significant impact on global pollution. Therefore, finding uncharacterised sources and assessing the emissions from these sources are important. However, limited data are available worldwide on mercury emissions from crematories. In Japan, 99.9% of dead bodies are cremated, which is the highest percentage in the world, and more than 1600 crematories are in operation. We thus focused on emissions from crematories in Japan. The number of targeted facilities was seven, and we used continuous emission monitoring to measure the mercury concentrations and investigate mercury behaviour. The total mercury concentrations in stack gases were a few μg/Nm3 (normal cubic meters. Considering the time profile of mercury and its species in cremations, the findings confirmed that the mercury in stack gas originated from dental amalgam. The amount of mercury emissions was calculated using the total concentration and gas flow rate. Furthermore, the annual amount of mercury emission from crematories in Japan was estimated by using the total number of corpses. The emission amount was considerably lower than that estimated in the United Kingdom. From statistical analyses on population demographics and measurements, future total emissions from crematories were also predicted. As a result, the amount of mercury emitted by crematories will likely increase by 2.6-fold from 2007 to 2037.

  4. Mercury emission from crematories in Japan

    Science.gov (United States)

    Takaoka, M.; Oshita, K.; Takeda, N.; Morisawa, S.

    2010-04-01

    Anthropogenic sources of mercury emissions have a significant impact on global pollution. Therefore, finding uncharacterised sources and assessing the emissions from these sources are important. However, limited data are available worldwide on mercury emissions from crematories. In Japan, 99.9% of dead bodies are cremated, which is the highest percentage in the world, and more than 1600 crematories are in operation. We thus focused on emissions from crematories in Japan. The number of targeted facilities was seven, and we used continuous emission monitoring to measure the mercury concentrations and investigate mercury behaviour. The total mercury concentrations in stack gases were a few μg/Nm3 (normal cubic meters). Considering the time profile of mercury and its species in cremations, the findings confirmed that the mercury in stack gas originated from dental amalgam. The amount of mercury emissions was calculated using the total concentration and gas flow rate. Furthermore, the annual amount of mercury emission from crematories in Japan was estimated by using the total number of corpses. The emission amount was considerably lower than that estimated in the United Kingdom. From statistical analyses on population demographics and measurements, future total emissions from crematories were also predicted. As a result, the amount of mercury emitted by crematories will likely increase by 2.6-fold from 2007 to 2037.

  5. Biochar and soil nitrous oxide emissions

    Directory of Open Access Journals (Sweden)

    Carlos Francisco Brazão Vieira Alho

    2012-05-01

    Full Text Available The objective of this work was to evaluate the effect of biochar application on soil nitrous oxide emissions. The experiment was carried out in pots under greenhouse conditions. Four levels of ground commercial charcoal of 2 mm (biochar were evaluated in a sandy Albaqualf (90% of sand: 0, 3, 6, and 9 Mg ha-1. All treatments received 100 kg ha-1 of N as urea. A cubic effect of biochar levels was observed on the N2O emissions. Biochar doses above 5 Mg ha-1 started to mitigate the emissions in the evaluated soil. However, lower doses promote the emissions.

  6. Survey of emissivity measurement by radiometric methods.

    Science.gov (United States)

    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.

  7. Biophoton emission induced by heat shock.

    Directory of Open Access Journals (Sweden)

    Katsuhiro Kobayashi

    Full Text Available Ultraweak biophoton emission originates from the generation of reactive oxygen species (ROS that are produced in mitochondria as by-products of cellular respiration. In healthy cells, the concentration of ROS is minimized by a system of biological antioxidants. However, heat shock changes the equilibrium between oxidative stress and antioxidant activity, that is, a rapid rise in temperature induces biophoton emission from ROS. Although the rate and intensity of biophoton emission was observed to increase in response to elevated temperatures, pretreatment at lower high temperatures inhibited photon emission at higher temperatures. Biophoton measurements are useful for observing and evaluating heat shock.

  8. Emissivity Measurement of Semitransparent Textiles

    Directory of Open Access Journals (Sweden)

    P. Bison

    2012-01-01

    Full Text Available In the textiles production industry it is more and more common to advertise new textiles, especially for sportswear, by claiming their ability to emit IR radiation in the long wave band at a higher degree with respect to normal clothes, that is highly beneficial to improve sporting performances. Three textiles are compared, one normal and two “special,” with Ag+ ions and carbon powder added, with different colors. The emissivity of the textiles has been measured to determine if it is increased in the “special” textiles with respect to the normal one. No substantial increase has been noticed. Nonetheless, the test implied some nonstandard procedures due to the semitransparent nature of the textiles, in comparison with the normal procedure that is commonly used on opaque surfaces.

  9. Exhaust emission control and diagnostics

    Science.gov (United States)

    Mazur, Christopher John; Upadhyay, Devesh

    2006-11-14

    A diesel engine emission control system uses an upstream oxidation catalyst and a downstream SCR catalyst to reduce NOx in a lean exhaust gas environment. The engine and upstream oxidation catalyst are configured to provide approximately a 1:1 ratio of NO to NO2 entering the downstream catalyst. In this way, the downstream catalyst is insensitive to sulfur contamination, and also has improved overall catalyst NOx conversion efficiency. Degradation of the system is determined when the ratio provided is no longer near the desired 1:1 ratio. This condition is detected using measurements of engine operating conditions such as from a NOx sensor located downstream of the catalysts. Finally, control action to adjust an injected amount of reductant in the exhaust gas based on the actual NO to NO2 ratio upstream of the SCR catalyst and downstream of the oxidation catalyst.

  10. Modeling molecular hyperfine line emission

    CERN Document Server

    Keto, Eric

    2010-01-01

    In this paper we discuss two approximate methods previously suggested for modeling hyperfine spectral line emission for molecules whose collisional transitions rates between hyperfine levels are unknown. Hyperfine structure is seen in the rotational spectra of many commonly observed molecules such as HCN, HNC, NH3, N2H+, and C17O. The intensities of these spectral lines can be modeled by numerical techniques such as Lambda-iteration that alternately solve the equations of statistical equilibrium and the equation of radiative transfer. However, these calculations require knowledge of both the radiative and collisional rates for all transitions. For most commonly observed radio frequency spectral lines, only the net collisional rates between rotational levels are known. For such cases, two approximate methods have been suggested. The first method, hyperfine statistical equilibrium (HSE), distributes the hyperfine level populations according to their statistical weight, but allows the population of the rotationa...

  11. Positron emission tomography basic sciences

    CERN Document Server

    Townsend, D W; Valk, P E; Maisey, M N

    2003-01-01

    Essential for students, science and medical graduates who want to understand the basic science of Positron Emission Tomography (PET), this book describes the physics, chemistry, technology and overview of the clinical uses behind the science of PET and the imaging techniques it uses. In recent years, PET has moved from high-end research imaging tool used by the highly specialized to an essential component of clinical evaluation in the clinic, especially in cancer management. Previously being the realm of scientists, this book explains PET instrumentation, radiochemistry, PET data acquisition and image formation, integration of structural and functional images, radiation dosimetry and protection, and applications in dedicated areas such as drug development, oncology, and gene expression imaging. The technologist, the science, engineering or chemistry graduate seeking further detailed information about PET, or the medical advanced trainee wishing to gain insight into the basic science of PET will find this book...

  12. Spontaneous Photon Emission in Cavities

    Directory of Open Access Journals (Sweden)

    Alber G.

    2014-01-01

    Full Text Available We investigate spontaneous photon emission processes of two-level atoms in parabolic and ellipsoidal cavities thereby taking into account the full multimode scenario. In particular, we calculate the excitation probabilities of the atoms and the energy density of the resulting few-photon electromagnetic radiation field by using semiclassical methods for the description of the multimode scenario. Based on this approach photon path representations are developed for relevant transition probability amplitudes which are valid in the optical frequency regime where the dipole and the rotating-wave approximations apply. Comparisons with numerical results demonstrate the quality of these semiclassical results even in cases in which the wave length of a spontaneously emitted photon becomes comparable or even larger than characteristic length scales of the cavity. This is the dynamical regime in which diffraction effects become important so that geometric optical considerations are typically not applicable.

  13. Radio Emission from Globular Clusters

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Radio emission of globular clusters is studied by analyzing the VLA radio survey data of the NVSS and FIRST. We find that 13 clusters have radio sources within their half-mass radii of clusters. Sources detected previously in NGC 7078and NGC 6440 are identified. Pulsars in NGC 6121, NGC 6440 and NGC 7078cannot be detected because of the insufficient survey sensitivity and resolution.There may be a pulsar in the core of Terzan 1. The nature of the extended radio source near the core of NGC 6440 remains unclear. In the core of a globular cluster,there may be many neutron stars or an intermediate mass black hole, but this cannot be clarified with the current radio observations.

  14. Kiln emissions and potters' exposures.

    Science.gov (United States)

    Hirtle, B; Teschke, K; van Netten, C; Brauer, M

    1998-10-01

    Some ten thousand British Columbia potters work in small private studios, cooperative facilities, educational institutions, or recreation centers. There has been considerable concern that this diffuse, largely unregulated activity may involve exposures to unacceptable levels of kiln emissions. Pottery kiln emissions were measured at 50 sites--10 from each of 5 categories: professional studios, recreation centers, elementary schools, secondary schools, and colleges. Area monitoring was done 76 cm from firing kilns and 1.6 m above the floor to assess breathing zone concentrations of nitrogen dioxide, carbon monoxide, sulfur dioxide, fluorides, aldehydes, aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, gold, iron, lead, lithium, magnesium, manganese, mercury, nickel, selenium, silver, vanadium, and zinc. Personal exposures to the same metals were measured at 24 sites. Almost all measured values were well below permissible concentrations for British Columbia work sites and American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) with the following two exceptions. A single firing duration (495 minute) acrolein measurement adjacent to an electric kiln (0.109 ppm) exceeded these guidelines. One 15-minute sulfur dioxide measurement collected adjacent to a gas kiln (5.7 ppm) exceeded the ACGIH short-term exposure limit. The fact that concentrations in small, ventilated kiln rooms ranked among the highest measured gives rise to concern that unacceptable levels of contamination may exist where small kiln rooms remain unventilated. Custom designed exhaust hoods and industrial heating, ventilating, and air-conditioning systems were the most effective ventilation strategies. Passive diffusion and wall/window fans were least effective.

  15. Observing BVOC emissions from Space

    Science.gov (United States)

    Oetjen, Hilke; Hewson, William; Comyn-Platt, Edward M.; Barkley, Michael P.; Bösch, Hartmut

    2016-04-01

    Formaldehyde (HCHO) is formed in the atmosphere as an intermediate from the oxidation of methane and other hydrocarbons such as isoprene, but also from combustion processes. Further, global and accurate measurements of HCHO from space are important since they can be used to infer global isoprene emission (e.g. Barkley et al., 2013), the primary biogenic volatile organic compound (BVOC) that cannot be monitored from space directly. However, isoprene is an important source of ozone and secondary organic aerosol, and a sink for the hydroxyl radical. HCHO absorbs in the ultraviolet wavelengths range and can therefore be detected by scattered sunlight absorption spectroscopy. Here we present measurements with the GOME-2 instrument. The first of the 3 GOME-2 instruments has been flying on MetOp-A since 2006 and MetOp-B has been launched in 2012. MetOp-C is expected to be launched in 2018. The University of Leicester retrieval (Hewson et al., 2015) is a well characterised state-of-the-art algorithm which has been used to infer HCHO vertical columns from MetOp-A, and more recently from MetOp-B. The results have been employed for creating a global, multi-year time series. This dataset has been exploited to analyse regional year-to-year variations in HCHO abundances and also to test emission models via comparisons to GEOS-Chem simulations. Barkley, M. P., et al. (2013), J. Geophys. Res. Atmos., 118, 6849-6868, doi:10.1002/jgrd.50552 Hewson, W., et al. (2015), Atmos. Meas. Tech., 8, 4055-4074, doi:10.5194/amt-8-4055-2015

  16. 77 FR 16508 - National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins...

    Science.gov (United States)

    2012-03-21

    ...: Group IV Polymers and Resins; Pesticide Active Ingredient Production; and Polyether Polyols Production... pollutants: National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins...: Group IV Polymers and Resins; Pesticide Active Ingredient Production; and Polyether Polyols...

  17. Field Measurements of PCB emissions from Building Surfaces Using a New Portable Emission Test Cell

    DEFF Research Database (Denmark)

    Lyng, Nadja; Haven, Rune; Gunnarsen, Lars Bo

    2016-01-01

    The purpose of the study was to measure PCB-emission rates from indoor surfaces on-site in contaminated buildings using a newly developed portable emission test cell. Emission rates were measured from six different surfaces; three untreated surfaces and three remediated surfaces in a contaminated...... Danish elementary school. The emission test cell was capable of measuring widely varying specific emission rates of PCBtotal (8-3357 ng/(m2·h)). Remediated measures were found to reduce the emission rates by more than 96% compared with similar untreated surfaces. Emission rates may be affected...... by the conditions in the test cell (such as clean air and increased air velocity) and thereby potentially be different without the test cell attached to the surface. Still the measured emission rates obtained by using the test cell are valuable for determination of mitigation strategies. Additionally the test cell...

  18. Emissions Of Greenhouse Gases From Rice Agriculture

    Energy Technology Data Exchange (ETDEWEB)

    M. Aslam K. Khalil

    2009-07-16

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

  19. Economic growth and carbon emission control

    Science.gov (United States)

    Zhang, Zhenyu

    The question about whether environmental improvement is compatible with continued economic growth remains unclear and requires further study in a specific context. This study intends to provide insight on the potential for carbon emissions control in the absence of international agreement, and connect the empirical analysis with theoretical framework. The Chinese electricity generation sector is used as a case study to demonstrate the problem. Both social planner and private problems are examined to derive the conditions that define the optimal level of production and pollution. The private problem will be demonstrated under the emission regulation using an emission tax, an input tax and an abatement subsidy respectively. The social optimal emission flow is imposed into the private problem. To provide tractable analytical results, a Cobb-Douglas type production function is used to describe the joint production process of the desired output and undesired output (i.e., electricity and emissions). A modified Hamiltonian approach is employed to solve the system and the steady state solutions are examined for policy implications. The theoretical analysis suggests that the ratio of emissions to desired output (refer to 'emission factor'), is a function of productive capital and other parameters. The finding of non-constant emission factor shows that reducing emissions without further cutting back the production of desired outputs is feasible under some circumstances. Rather than an ad hoc specification, the optimal conditions derived from our theoretical framework are used to examine the relationship between desired output and emission level. Data comes from the China Statistical Yearbook and China Electric Power Yearbook and provincial information of electricity generation for the year of 1993-2003 are used to estimate the Cobb-Douglas type joint production by the full information maximum likelihood (FIML) method. The empirical analysis shed light on the optimal

  20. Seasonal trends of biogenic terpene emissions.

    Science.gov (United States)

    Helmig, Detlev; Daly, Ryan Woodfin; Milford, Jana; Guenther, Alex

    2013-09-01

    Biogenic volatile organic compound (BVOC) emissions from six coniferous tree species, i.e. Pinus ponderosa (Ponderosa Pine), Picea pungens (Blue Spruce), Pseudotsuga menziesii (Rocky Mountain Douglas Fir) and Pinus longaeva (Bristlecone Pine), as well as from two deciduous species, Quercus gambelii (Gamble Oak) and Betula occidentalis (Western River Birch) were studied over a full annual growing cycle. Monoterpene (MT) and sesquiterpene (SQT) emissions rates were quantified in a total of 1236 individual branch enclosure samples. MT dominated coniferous emissions, producing greater than 95% of BVOC emissions. MT and SQT demonstrated short-term emission dependence with temperature. Two oxygenated MT, 1,8-cineol and piperitone, were both light and temperature dependent. Basal emission rates (BER, normalized to 1000μmolm(-2)s(-1) and 30°C) were generally higher in spring and summer than in winter; MT seasonal BER from the coniferous trees maximized between 1.5 and 6.0μgg(-1)h(-1), while seasonal lows were near 0.1μgg(-1)h(-1). The fractional contribution of individual MT to total emissions was found to fluctuate with season. SQT BER measured from the coniferous trees ranged from temperature dependence in emissions modeling, was not found to exhibit discernible growth season trends. A seasonal correction factor proposed by others in previous work to account for a sinusoidal shaped emission pattern was applied to the data. Varying levels of agreement were found between the data and model results for the different plant species seasonal data sets using this correction. Consequently, the analyses on this extensive data set suggest that it is not feasible to apply a universal seasonal correction factor across different vegetation species. A modeling exercise comparing two case scenarios, (1) without and (2) with consideration of the seasonal changes in emission factors illustrated large deviations when emission factors are applied for other seasons than those in which

  1. 40 CFR 60.33c - Emission guidelines for municipal solid waste landfill emissions.

    Science.gov (United States)

    2010-07-01

    ... Guidelines and Compliance Times for Municipal Solid Waste Landfills § 60.33c Emission guidelines for municipal solid waste landfill emissions. (a) For approval, a State plan shall include control of MSW... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Emission guidelines for municipal...

  2. Modeling regional-scale wildland fire emissions with the wildland fire emissions information system

    Science.gov (United States)

    Nancy H.F. French; Donald McKenzie; Tyler Erickson; Benjamin Koziol; Michael Billmire; K. Endsley; Naomi K.Y. Scheinerman; Liza Jenkins; Mary E. Miller; Roger Ottmar; Susan Prichard

    2014-01-01

    As carbon modeling tools become more comprehensive, spatial data are needed to improve quantitative maps of carbon emissions from fire. The Wildland Fire Emissions Information System (WFEIS) provides mapped estimates of carbon emissions from historical forest fires in the United States through a web browser. WFEIS improves access to data and provides a consistent...

  3. Implications of diesel emissions control failures to emission factors and road transport NOx evolution

    NARCIS (Netherlands)

    Ntziachristos, L.; Papadimitriou, G.; Ligterink, N.; Hausberger, S.

    2016-01-01

    Diesel NOx emissions have been at the forefront of research and regulation scrutiny as a result of failures of late vehicle technologies to deliver on-road emissions reductions. The current study aims at identifying the actual emissions levels of late light duty vehicle technologies, including Euro

  4. Toward an Empirical Theory of Pulsar Emission. X. On the Precursor and Postcursor Emission

    NARCIS (Netherlands)

    Basu, R.; Mitra, D.; Rankin, J.M.

    2015-01-01

    Precursors and postcursors (PPCs) are rare emission components, which appear beyond the main pulse emission, in some cases far away from it, and are detected in a handful of pulsar. In this paper we attempt to characterize the PPC emission in relation to the pulsar main pulse geometry. In our

  5. The TRANSIMS Approach to Emission Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Barth, M.J.; Smith, L.; Thayer, G.R.; Williams, M.D.

    1999-02-01

    Transportation systems play a significant role in urban air quality, energy consumption and carbon-dioxide emissions. Recently, it has been found that current systems for estimating emissions of pollutants from transportation devices lead to significant inaccuracies. Most of the existing emission modules use very aggregate representations of traveler behavior and attempt to estimate emissions on typical driving cycles. However, recent data suggests that typical driving cycles produce relatively low emissions with most emissions coming from off-cycle driving, cold-starts, malfunctioning vehicles, and evaporative emissions. TRANSIMS is a simulation system for the analysis of transportation options in metropolitan areas. It's major functional components are: (1) a population disaggregation module, (2) a travel planning module, (3) a regional microsimulation module, and (4) an environmental module. In addition to the major functional components, it includes a strong underpining of simulation science and an analyst's tool box. The purpose of the environmental module is to translate traveler behavior into consequent air quality. The environmental module uses information from the TRANSIMS planner and the microsimulation and it supports the analyst's toolbox. The TRANSIMS system holds the promise of a more complete description of the role of heterogeneity in transportation in emission estimation.

  6. Development of South African vehicle emission factors

    CSIR Research Space (South Africa)

    Forbes, P

    2009-10-01

    Full Text Available Table 1. Comparison of different vehicle emissions measurement techniques. 2. Monitoring methodology 2.1. Diesel vehicles Diesel vehicle emissions in idling and accelerated mode (2 000 rpm) were tested by means of an IMR 1400 Diga portable gas...

  7. Projecting human development and CO2 emissions

    CERN Document Server

    Costa, Luís; Kropp, Jürgen P

    2012-01-01

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

  8. Neutrino emissivity under neutral kaon condensation

    CERN Document Server

    Kubis, S

    2006-01-01

    Neutrino emissivity from neutron star matter with neutral kaon condensate is considered. It is shown that a new cooling channel is opened, and what is more, all previously known channels acquire the greater emissivity reaching the level of the direct URCA cycle in normal matter.

  9. Positron Emission Mammotomography with Dual Planar Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mark Smith; Raymond Raylman; Stanislaw Majewski

    2003-06-29

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

  10. Properties and geometry of radio pulsar emission

    NARCIS (Netherlands)

    Smits, Johannes Martinus

    2006-01-01

    This thesis consists of a number of studies on the radio emission of pulsars. The central topics are polarisation and multi frequency observations, which both lead to important information on the geometry of the emission. The first chapter introduces different aspects of pulsars that are related to

  11. Volatile organic compound emissions from silage systems

    Science.gov (United States)

    As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols with other impor...

  12. Fracto—emissions in Catastrophic Cleavage Process

    Institute of Scientific and Technical Information of China (English)

    HonglaiTAN; WeiYANG

    1996-01-01

    Fracto-emissions accompanying crack propagation are observed in the recent experiments.The energy impulses during and after fracture stimulate the fracto-emissions.Model concerning atomic scale cleavage processes is proposed to formulate a catastrophic fracure theory relevant to these phenomena.A criterion for catastrophic jump of the cleavage potential is applied to representative crystals.

  13. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-10-01

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

  14. European initiatives for modeling emissions from transport

    DEFF Research Database (Denmark)

    Joumard, Robert; Hickman, A. John; Samaras, Zissis

    1998-01-01

    In Europe there have been many cooperative studies into transport emission inventories since the late 80s. These cover the scope of CORINAIR program involving experts from seven European Community laboratories addressing only road transport emissions at national level. These also include the late...

  15. 33 CFR 157.166 - Hydrocarbon emissions.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hydrocarbon emissions. 157.166... Crude Oil Washing (COW) System on Tank Vessels Cow Operations § 157.166 Hydrocarbon emissions. If the... ballasted in that port the hydrocarbon vapors in each tank are contained by a means under § 157.132....

  16. The EU Greenhouse Gas Emissions Trading Scheme

    NARCIS (Netherlands)

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

    2015-01-01

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

  17. 47 CFR 90.669 - Emission limits.

    Science.gov (United States)

    2010-10-01

    ... MOBILE RADIO SERVICES Regulations Governing Licensing and Use of Frequencies in the 806-824, 851-869, 896... 896-901/935-940 Mhz Band § 90.669 Emission limits. (a) On any frequency in an MTA licensee's spectrum block that is adjacent to a non-MTA frequency, the power of any emission shall be attenuated below...

  18. 40 CFR 61.162 - Emission limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Emission limits. 61.162 Section 61.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... From Glass Manufacturing Plants § 61.162 Emission limits. (a) The owner or operator of an...

  19. 47 CFR 90.1323 - Emission limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission limits. 90.1323 Section 90.1323 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Wireless Broadband Services in the 3650-3700 MHz Band § 90.1323 Emission limits....

  20. Sulfur Dioxide Emission Control, Blockade and Drainage

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper presents the present status of sulfur dioxide emission from thermal plants in China, tells the main problems existing in its emission control and finally gives out suggestions to the problems, that is, to constitute complete standards and regulations and enhancesupervision accordingly.

  1. Heavy metal emissions for Danish road transport

    Energy Technology Data Exchange (ETDEWEB)

    Winther, M.; Slentoe, E.

    2010-04-15

    This report presents new heavy metal emission factors for cars, vans, trucks, buses, mopeds and motorcycles for each of the emission sources fuel consumption, engine oil, tyre wear, brake wear and road abrasion. The emission components covered are Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pb), Selenium (Se) and Zinc (Zn), all of them relevant for emission reporting to the UNECE CLRTAP (United Nations Economic Commission for Europe Convention on Long Range Transboundary Pollutants) convention. The report also presents a new Danish inventory for the year 2007. The following emissions in total TSP (in brackets) are calculated for the year 2007: As (8 kg), Cd (48 kg), Cr (197 kg), Cu (51 779 kg), Hg (28 kg), Ni (158 kg), Pb (6 989 kg), Se (33 kg) and Zn (28 556 kg). Per vehicle type cars are the most important source of emission for all heavy metal species, followed by vans, trucks, buses and 2-wheelers. By using the detailed emission factors and inventory calculation methods established in the present project, estimates of heavy metal emissions can be made for other years than 2007. (author)

  2. Evaporation Controlled Emission in Ventilated Rooms

    DEFF Research Database (Denmark)

    Topp, Claus; Nielsen, Peter V.; Heiselberg, Per

    -scale ventilated room when the emission is fully or partly evaporation controlled. The objective of the present research work has been to investigate the change of emission rates from small-scale experiments to full-scale ventilated rooms and to investigate the influence of the local air velocity field near...

  3. Carbon dioxide emissions from international air freight

    Science.gov (United States)

    Howitt, Oliver J. A.; Carruthers, Michael A.; Smith, Inga J.; Rodger, Craig J.

    2011-12-01

    Greenhouse gas emissions from international air transport were excluded from reduction targets under the Kyoto Protocol, partly because of difficulties with quantifying and apportioning such emissions. Although there has been a great deal of recent research into calculating emissions from aeroplane operations globally, publicly available emissions factors for air freight emissions are scarce. This paper presents a methodology to calculate the amount of fuel burnt and the resulting CO 2 emissions from New Zealand's internationally air freighted imports and exports in 2007. This methodology could be applied to other nations and/or regions. Using data on fuel uplift, air freight and air craft movements, and assumptions on mean passenger loadings and the mass of passengers and air freight, CO 2 emissions factors of 0.82 kg CO 2 per t-km and 0.69 kg CO 2 per t-km for short-haul and long-haul journeys, respectively, were calculated. The total amount of fuel consumed for the international air transport of New Zealand's imports and exports was calculated to be 0.21 Mt and 0.17 Mt respectively, with corresponding CO 2 emissions of 0.67 Mt and 0.53 Mt.

  4. Hiss emissions during quiet and disturbed periods

    Indian Academy of Sciences (India)

    D K Singh; R P Singh

    2002-10-01

    The characteristic features of VLF hiss emissions during quiet and disturbed conditions observed at ground stations and on-board satellites are summarized. The increased intensity of the hiss emissions during magnetic storm period is explained by considering the enhanced flux of energetic electrons during magnetic storm period. The generation and propagation mechanism of VLF hiss are also briefly discussed.

  5. Modeling Greenhouse Gas Emissions from Enteric Fermentation

    NARCIS (Netherlands)

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

    2016-01-01

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

  6. International Emissions Trading : Design and Political Acceptability

    NARCIS (Netherlands)

    Boom, Jan Tjeerd

    2006-01-01

    This thesis discusses the design and political acceptability of international emissions trading. It is shown that there are several designs options for emissions trading at the national level that have a different impact on output and thereby related factors such as employment and consumer prices.

  7. Spontaneous emission from active dielectric microstructures

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Tromborg, Bjarne

    2001-01-01

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

  8. 40 CFR 52.1533 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Emission inventories. 52.1533 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Hampshire § 52.1533 Emission inventories... inventory for the entire state on January 26, 1993 as a revision to the State Implementation Plan...

  9. 40 CFR 52.2086 - Emission inventories.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Emission inventories. 52.2086 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Rhode Island § 52.2086 Emission inventories... inventory for the Providence ozone nonattainment area on January 12, 1993 as a revision to the...

  10. Planck 2013 results. XIV. Zodiacal emission

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.

    2013-01-01

    , three asteroidal dust bands, a circumsolar ring, and an Earth-trailing feature. The emissivity of the diuse cloud decreases with increasing wavelength, as expected from earlier analyses. The emissivities of the dust bands, however, decrease less rapidly, indicating that the properties of the grains...

  11. The carbon emissions of Chinese cities

    Science.gov (United States)

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

    2012-07-01

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

  12. Graviton Emission and Absorption by Atomic Hydrogen

    CERN Document Server

    Rothman, S B T

    2006-01-01

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

  13. Tabulated Neutron Emission Rates for Plutonium Oxide

    Energy Technology Data Exchange (ETDEWEB)

    Shores, Erik Frederick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-24

    This work tabulates neutron emission rates for 80 plutonium oxide samples as reported in the literature. Plutonium-­238 and plutonium-­239 oxides are included and such emission rates are useful for scaling tallies from Monte Carlo simulations and estimating dose rates for health physics applications.

  14. Global sulfur emissions from 1850 to 2000.

    Science.gov (United States)

    Stern, David I

    2005-01-01

    The ASL database provides continuous time-series of sulfur emissions for most countries in the World from 1850 to 1990, but academic and official estimates for the 1990s either do not cover all years or countries. This paper develops continuous time series of sulfur emissions by country for the period 1850-2000 with a particular focus on developments in the 1990s. Global estimates for 1996-2000 are the first that are based on actual observed data. Raw estimates are obtained in two ways. For countries and years with existing published data I compile and integrate that data. Previously published data covers the majority of emissions and almost all countries have published emissions for at least 1995. For the remaining countries and for missing years for countries with some published data, I interpolate or extrapolate estimates using either an econometric emissions frontier model, an environmental Kuznets curve model, or a simple extrapolation, depending on the availability of data. Finally, I discuss the main movements in global and regional emissions in the 1990s and earlier decades and compare the results to other studies. Global emissions peaked in 1989 and declined rapidly thereafter. The locus of emissions shifted towards East and South Asia, but even this region peaked in 1996. My estimates for the 1990s show a much more rapid decline than other global studies, reflecting the view that technological progress in reducing sulfur based pollution has been rapid and is beginning to diffuse worldwide.

  15. Constraining CO emission estimates using atmospheric observations

    NARCIS (Netherlands)

    Hooghiemstra, P.B.

    2012-01-01

    We apply a four-dimensional variational (4D-Var) data assimilation system to optimize carbon monoxide (CO) emissions and to reduce the uncertainty of emission estimates from individual sources using the chemistry transport model TM5. In the first study only a limited amount of surface network obs

  16. Neutrino emissivity under neutral kaon condensation

    OpenAIRE

    Kubis, Sebastian

    2005-01-01

    Neutrino emissivity from neutron star matter with neutral kaon condensate is considered. It is shown that a new cooling channel is opened, and what is more, all previously known channels acquire the greater emissivity reaching the level of the direct URCA cycle in normal matter.

  17. 47 CFR 22.861 - Emission limitations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Emission limitations. 22.861 Section 22.861 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Air... emission or technology that complies with the technical rules in this subpart. (a) Out of band...

  18. International Emissions Trading : Design and Political Acceptability

    NARCIS (Netherlands)

    Boom, Jan Tjeerd

    2006-01-01

    This thesis discusses the design and political acceptability of international emissions trading. It is shown that there are several designs options for emissions trading at the national level that have a different impact on output and thereby related factors such as employment and consumer prices. T

  19. The EU Greenhouse Gas Emissions Trading Scheme

    NARCIS (Netherlands)

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

    2015-01-01

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

  20. The value relevance of environmental emissions

    Directory of Open Access Journals (Sweden)

    Melinda Lydia Nelwan

    2016-07-01

    Full Text Available This study examines whether environmental performance has value relevance by investigating the relations between environmental emissions and stock prices for the U.S. public companies. The previous studies argued that the conjectured relations between accounting performance measures and environmental performance do not have a strong theoretical basis, and the modeling of relations between market per-formance measures and environmental performance do not adequately consider the relevance of accounting performance to market value. Therefore, this study examines whether publicly reported environmental emissions provide incremental information to accounting earnings in pricing companies stocks. It is done among the complete set of industries covered by Toxics Release Inventory (TRI reporting for the period 2007 to 2010. Using Ohlson model but modified to include different types of emis-sions, it is found that ground emissions (underground injection and land emissions are value relevant but other emission types (air and water and transferred-out emis-sions appear to not provide incremental information in the valuation model. The result in this study raise concerns that different types of emissions are assessed differently by the market, confirming that studies should not aggregate such measures.

  1. Inventorying emissions from nature in Europe

    Science.gov (United States)

    Simpson, David; Winiwarter, Wilfried; BöRjesson, Gunnar; Cinderby, Steve; Ferreiro, Antonio; Guenther, Alex; Hewitt, C. Nicholas; Janson, Robert; Khalil, M. Aslam K.; Owen, Susan; Pierce, Tom E.; Puxbaum, Hans; Shearer, Martha; Skiba, Ute; Steinbrecher, Rainer; Tarrasón, Leonor; Äquist, Mats G.

    1999-04-01

    As part of the work of the Economic Commission for Europe of the United Nations Task Force on Emission Inventories, a new set of guidelines has been developed for assessing the emissions of sulphur, nitrogen oxides, NH3, CH4, and nonmethane volatile organic compounds (NMVOC) from biogenic and other natural sources in Europe. This paper gives the background to these guidelines, describes the sources, and gives our recommended methodologies for estimating emissions. We have assembled land use and other statistics from European or national compilations and present emission estimates for the various natural/biogenic source categories based on these. Total emissions from nature derived here amount to ˜1.1 Tg S yr-1, 6-8 Tg CH4 yr-1, 70 Gg NH3 (as N) yr-1, and 13 Tg NMVOC yr-1. Estimates of biogenic NOx emissions cover a wide range, from 140 to 1500 Gg NOx (as N) yr-1. In terms of relative contribution to total European emissions for different pollutants, then NMVOC from forests and vegetation are clearly the most important emissions source. Biogenic NOx emissions (although heavily influenced by nitrogen inputs from anthropogenic activities) are very important if the higher estimates are reliable. CH4 from wetlands and sulphur from volcanoes are also significant emissions in the European budgets. On a global scale, European biogenic emissions are not significant, a consequence of the climate and size (7% of global land area) of Europe and of the destruction of natural ecosystems since prehistoric times. However, for assessing local budgets and for photochemical oxidant modeling, natural/biogenic emissions can play an important role. The most important contributor in this regard is undoubtedly forest VOC emissions, although this paper also indicates that NMVOC emissions from nonforested areas also need to be further evaluated. This paper was originally conceived as a contribution to the collection of papers arising as a result of the Workshop on Biogenic Hydrocarbons in

  2. The Of emission lines near 4650 A

    Science.gov (United States)

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

    1989-09-01

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

  3. Enteric methane emissions from German pigs

    DEFF Research Database (Denmark)

    Dämmgen, Ulrich; Schulz, Joachim; Klausing, Heinrich Kleine

    2012-01-01

    Methane emissions from enteric fermentation of pigs are object of emission reporting. Hitherto they were treated as part of the energy balance of pigs, in accordance with IPCC guidance documents. They were calculated from the gross energy intake rate and a constant methane conversion ratio....... Meanwhile numerous experimental data on methane emissions from enteric fermentation is available in Germany and abroad; the results are compiled in this work. These results also allow for a description of transformation processes in the hind gut and a subsequent establishment of models that relate emissions...... to feed and performance data. The model by Kirchgeßner et al. (1995) is based on German experimental data and reflects typical national diet compositions. It is used to quantify typical emissions and methane conversion ratios. The results agree with other experimental findings at home and abroad...

  4. Enteric methane emissions from German dairy cows

    DEFF Research Database (Denmark)

    Dammgen, U; Rosemann, C; Haenel, H D

    2012-01-01

    Up to now, the German agricultural emission inventory used a model for the assessment of methane emissions from enteric fermentation that combined an estimate of the energy and feed requirements as a function of performance parameters and diet composition, with the constant methane conversion rate......, as stated by IPCC. A methane emission model was selected here that is based on German feed data. It was combined with the hitherto applied model describing energy requirements. The emission rates thus calculated deviate from those previously obtained. In the new model, the methane conversion rate is back......-calculated from emission rates and gross energy intake rates. For German conditions of animal performance and diet composition, the national means of methane conversion rates range between 71 kJ MJ(-1) and 61 kJ MJ(-1) for low and high performances (4700 kg animal(-1) a(-1) in 1990 to 7200 kg animal(-1) a(-1...

  5. Genetic Algorithm Based Microscale Vehicle Emissions Modelling

    Directory of Open Access Journals (Sweden)

    Sicong Zhu

    2015-01-01

    Full Text Available There is a need to match emission estimations accuracy with the outputs of transport models. The overall error rate in long-term traffic forecasts resulting from strategic transport models is likely to be significant. Microsimulation models, whilst high-resolution in nature, may have similar measurement errors if they use the outputs of strategic models to obtain traffic demand predictions. At the microlevel, this paper discusses the limitations of existing emissions estimation approaches. Emission models for predicting emission pollutants other than CO2 are proposed. A genetic algorithm approach is adopted to select the predicting variables for the black box model. The approach is capable of solving combinatorial optimization problems. Overall, the emission prediction results reveal that the proposed new models outperform conventional equations in terms of accuracy and robustness.

  6. Enteric methane emissions from German pigs

    DEFF Research Database (Denmark)

    Dämmgen, Ulrich; Schulz, Joachim; Klausing, Heinrich Kleine

    2012-01-01

    Methane emissions from enteric fermentation of pigs are object of emission reporting. Hitherto they were treated as part of the energy balance of pigs, in accordance with IPCC guidance documents. They were calculated from the gross energy intake rate and a constant methane conversion ratio....... Meanwhile numerous experimental data on methane emissions from enteric fermentation is available in Germany and abroad; the results are compiled in this work. These results also allow for a description of transformation processes in the hind gut and a subsequent establishment of models that relate emissions...... to feed and performance data. The model by Kirchgeßner et al. (1995) is based on German experimental data and reflects typical national diet compositions. It is used to quantify typical emissions and methane conversion ratios. The results agree with other experimental findings at home and abroad...

  7. Enteric methane emissions from German dairy cows

    DEFF Research Database (Denmark)

    Dammgen, U; Rosemann, C; Haenel, H D

    2012-01-01

    Up to now, the German agricultural emission inventory used a model for the assessment of methane emissions from enteric fermentation that combined an estimate of the energy and feed requirements as a function of performance parameters and diet composition, with the constant methane conversion rate......, as stated by IPCC. A methane emission model was selected here that is based on German feed data. It was combined with the hitherto applied model describing energy requirements. The emission rates thus calculated deviate from those previously obtained. In the new model, the methane conversion rate is back......-calculated from emission rates and gross energy intake rates. For German conditions of animal performance and diet composition, the national means of methane conversion rates range between 71 kJ MJ(-1) and 61 kJ MJ(-1) for low and high performances (4700 kg animal(-1) a(-1) in 1990 to 7200 kg animal(-1) a(-1...

  8. The primordial helium abundance from updated emissivities

    CERN Document Server

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

    2013-01-01

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

  9. Stimulated emission from NV centres in diamond

    CERN Document Server

    Jeske, Jan; McGuinness, Liam P; Reineck, Philip; Johnson, Brett C; McCallum, Jeffrey C; Jelezko, Fedor; Volz, Thomas; Cole, Jared H; Gibson, Brant C; Greentree, Andrew D

    2016-01-01

    Stimulated emission is the process fundamental to laser operation, thereby producing coherent photon output. Despite negatively-charged nitrogen-vacancy (NV$^-$) centres being discussed as a potential laser medium since the 1980's, there have been no definitive observations of stimulated emission from ensembles of NV$^-$ to date. Reasons for this lack of demonstration include the short excited state lifetime and the occurrence of photo-ionisation to the neutral charge state by light around the zero-phonon line. Here we show both theoretical and experimental evidence for stimulated emission from NV$^-$ states using light in the phonon-sidebands. Our system uses a continuous wave pump laser at 532 nm and a pulsed stimulating laser that is swept across the phononic sidebands of the NV$^-$. Optimal stimulated emission is demonstrated in the vicinity of the three-phonon line at 700 nm. Furthermore, we show the transition from stimulated emission to photoionisation as the stimulating laser wavelength is reduced fro...

  10. Flatus emission patterns and fibre intake.

    Science.gov (United States)

    Bolin, T D; Stanton, R A

    1998-01-01

    Knowledge of the normal range of flatus emissions and their relationship to diet, particularly fibre, would be helpful in managing patients who complain of excessive flatus or abdominal distention. Sixty men and 60 women aged between 17 and 67 kept a three-day daily record, including one week-end day, of their flatus emissions, dietary fibre intake and beer consumption. Daily flatus emissions averaged 12.7 (range to 2-53) for men and 7.1 (range 1-32) for women. Fibre intake averaged 28+/-13 g for men and 24+/-3 g for women. Flatus emissions significantly correlated with dietary fibre intake (pflatus emissions and beer intake in men and men recorded more aromatic flatus than women. This study of 120 normal individuals eating their choice of foods provides a basis to judge degrees of abnormality in patients complaining of excessive flatus.

  11. Indirect emissions from biofuels: how important?

    Science.gov (United States)

    Melillo, Jerry M; Reilly, John M; Kicklighter, David W; Gurgel, Angelo C; Cronin, Timothy W; Paltsev, Sergey; Felzer, Benjamin S; Wang, Xiaodong; Sokolov, Andrei P; Schlosser, C Adam

    2009-12-04

    A global biofuels program will lead to intense pressures on land supply and can increase greenhouse gas emissions from land-use changes. Using linked economic and terrestrial biogeochemistry models, we examined direct and indirect effects of possible land-use changes from an expanded global cellulosic bioenergy program on greenhouse gas emissions over the 21st century. Our model predicts that indirect land use will be responsible for substantially more carbon loss (up to twice as much) than direct land use; however, because of predicted increases in fertilizer use, nitrous oxide emissions will be more important than carbon losses themselves in terms of warming potential. A global greenhouse gas emissions policy that protects forests and encourages best practices for nitrogen fertilizer use can dramatically reduce emissions associated with biofuels production.

  12. Sharing a quota on cumulative carbon emissions

    Science.gov (United States)

    Raupach, Michael R.; Davis, Steven J.; Peters, Glen P.; Andrew, Robbie M.; Canadell, Josep G.; Ciais, Philippe; Friedlingstein, Pierre; Jotzo, Frank; van Vuuren, Detlef P.; Le Quéré, Corinne

    2014-10-01

    Any limit on future global warming is associated with a quota on cumulative global CO2 emissions. We translate this global carbon quota to regional and national scales, on a spectrum of sharing principles that extends from continuation of the present distribution of emissions to an equal per-capita distribution of cumulative emissions. A blend of these endpoints emerges as the most viable option. For a carbon quota consistent with a 2 °C warming limit (relative to pre-industrial levels), the necessary long-term mitigation rates are very challenging (typically over 5% per year), both because of strong limits on future emissions from the global carbon quota and also the likely short-term persistence in emissions growth in many regions.

  13. CO2 Emission Factors for Coals

    Directory of Open Access Journals (Sweden)

    P. Orlović-Leko

    2015-03-01

    Full Text Available Emission factors are used in greenhouse gas inventories to estimate emissions from coal combustion. In the absence of direct measures, emissions factors are frequently used as a quick, low cost way to estimate emissions values. Coal combustion has been a major contributor to the CO2 flux into the atmosphere. Nearly all of the fuel carbon (99 % in coal is converted to CO2 during the combustion process. The carbon content is the most important coal parameter which is the measure of the degree of coalification (coal rank. Coalification is the alteration of vegetation to form peat, succeeded by the transformation of peat through lignite, sub-bituminous, bituminous to anthracite coal. During the geochemical or metamorphic stage, the progressive changes that occur within the coal are an increase in the carbon content and a decrease in the hydrogen and oxygen content resulting in a loss of volatiles. Heterogeneous composition of coal causes variation in CO2 emission from different coals. The IPCC (Intergovernmental Panel on Climate Change has produced guidelines on how to produce emission inventories which includes emission factors. Although 2006 IPCC Guidelines provided the default values specified according to the rank of the coal, the application of country-specific emission factors was recommended when estimating the national greenhouse gas emissions. This paper discusses the differences between country-specific emission factors and default IPCC CO2 emission factors, EF(CO2, for coals. Also, this study estimated EF(CO2 for two different types of coals and peat from B&H, on the basis fuel analyses. Carbon emission factors for coal mainly depend on the carbon content of the fuel and vary with both rank and geographic origin, which supports the idea of provincial variation of carbon emission factors. Also, various other factors, such as content of sulphur, minerals and macerals play an important role and influence EF(CO2 from coal. Carbonate minerals

  14. Greenhouse gas emissions in Hong Kong

    Science.gov (United States)

    Leung, D. Y. C.; Lee, Y. T.

    This study provides a quantitative review of the emissions of carbon dioxide (CO 2) and methane (CH 4), the two most significant greenhouse gases (GHGs) in Hong Kong. Study indicated that CO 2 accounts for 90% of the local GHG emissions in Hong Kong. Among the different types of fuels coal is identified as the major source of CO 2, which constitutes about 50% by fuel type. On the other hand, CH 4, which mainly comes from waste decomposition, contributes to 5% of the total GHG emissions. Correlation study revealed that energy consumption and waste quantity were strongly correlated with population and gross domestic products (GDP), implying that not much has been done in Hong Kong to re-mediate GHG emissions. Regression analysis concluded that supply side management (fuel switch) was more effective than demand side management (energy conservation) in mitigating CO 2 emissions in Hong Kong.

  15. Cryptic Methane Emissions from Upland Forest Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-19

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

  16. Anthropogenic CO2 emissions in Africa

    Directory of Open Access Journals (Sweden)

    R. A. Houghton

    2008-11-01

    Full Text Available An understanding of the regional contributions and trends of anthropogenic carbon dioxide (CO2 emissions is critical to design mitigation strategies aimed at stabilizing atmospheric greenhouse gases. Here we report CO2 emissions from the combustion of fossil fuels and land use change in Africa for various time periods. Africa was responsible for an average of 500 TgC y−1 for the period 2000–2005. These emissions resulted from the combustion of fossil fuels (260 TgC y−1 and land use change (240 TgC y−1. Over this period, the African share of global emissions from land use change was 17%. For 2005, the last year reported in this study, African fossil fuel emissions were 285 TgC accounting for 3.7% of the global emissions. The 2000–2005 growth rate in African fossil fuel emissions was 3.2% y−1, very close to the global average. Fossil fuel emissions per capita in Africa are among the lowest in the world, at 0.32 tC y−1 compared to the global average of 1.2 tC y−1. The average amount of carbon (C emitted as CO2 to produce 1 US $ of Gross Domestic Product (GDP in Africa in 2005 was 187 gC/$, close to the world average of 199 gC/$. With the fastest population growth in the world and rising per capita GDP, Africa is likely to increase its share of global emissions over the coming decades although emissions from Africa will remain low compared to other continents.

  17. Revising China's energy consumption and carbon emissions

    Science.gov (United States)

    Liu, Z.

    2015-12-01

    China is the world's largest carbon emitter and takes the lion's share of new increased emission since 2000, China's carbon emissions and mitigation efforts have received global attentions (Liu et al., Nature 500, 143-145)1. Yet China's emission estimates have been approved to be greatly uncertain (Guan et al., Nature Climate Change 2, 672-675)2. Accurate estimation becomes even crucial as China has recently pledged to reach a carbon emission peak by 2030, but no quantitative target has been given, nor is it even possible to assess without a reasonable baseline. Here we produced new estimates of Chinese carbon emissions for 1950-2012 based on a new investigation in energy consumption activities and emission factors using extensively surveyed and experimental data from 4243 mines and 602 coal samples. We reported that the total energy consumption is 10% higher than the nationally published value. The investigated emission factors used in China are significantly (40%) different from the IPCC default values which were used in drawing up several previous emission inventories. The final calculated total carbon emissions from China are 10% different than the amount reported by international data sets. The new estimate provides a revision of 4% of global emissions, which could have important implications for global carbon budgets and burden-sharing of climate change mitigation. 1 Liu, Z. et al. A low-carbon road map for China. Nature 500, 143-145 (2013). 2 Guan, D., Liu, Z., Geng, Y., Lindner, S. & Hubacek, K. The gigatonne gap in China's carbon dioxide inventories. Nature Climate Change, 672-675 (2012).

  18. Pattern changes in determinants of Chinese emissions

    Science.gov (United States)

    Mi, Zhifu; Meng, Jing; Guan, Dabo; Shan, Yuli; Liu, Zhu; Wang, Yutao; Feng, Kuishuang; Wei, Yi-Ming

    2017-07-01

    The Chinese economy has been recovering slowly from the global financial crisis, but it cannot achieve the same rapid development of the pre-recession period. Instead, the country has entered a new phase of economic development—a ‘new normal’. We use a structural decomposition analysis and environmental input-output analysis to estimate the determinants of China’s carbon emission changes during 2005-2012. China’s imports are linked to a global multi-regional input-output model based on the Global Trade and Analysis Project database to calculate the embodied CO2 emissions in imports. We find that the global financial crisis has affected the drivers of China’s carbon emission growth. From 2007 to 2010, the CO2 emissions induced by China’s exports dropped, whereas emissions induced by capital formation grew rapidly. In the ‘new normal’, the strongest factors that offset CO2 emissions have shifted from efficiency gains to structural upgrading. Efficiency was the strongest factor offsetting China’s CO2 emissions before 2010 but drove a 1.4% increase in emissions in the period 2010-2012. By contrast, production structure and consumption patterns caused a 2.6% and 1.3% decrease, respectively, in China’s carbon emissions from 2010 to 2012. In addition, China tends to shift gradually from an investment to a consumption-driven economy. The proportion of CO2 emissions induced by consumption had a declining trend before 2010 but grew from 28.6%-29.1% during 2010-2012.

  19. Real-time vehicle emission monitoring along roadsides

    NARCIS (Netherlands)

    Stelwagen, U.; Lange, R. de; Ligterink, N.E.; Klunder, G.A.; Bigazzi, A.; Duyzer, J.H.; Baalen, J. van; Katwijk, R.T. van; Kruithof, M.C.; Ratingen, S. van; Weststrate, J.H.; Wilmink, I.R.

    2010-01-01

    In the worldwide efforts to reduce the emissions of greenhouse gasses in general and those emitted by vehicles in particular, vehicle emission monitoring is important. It provides accurate knowledge of real-world emissions of vehicles as input for vehicle emission models. Real-time emission monitori

  20. Lightning Imaging via VHF Emission

    Science.gov (United States)

    Kawasaki, Z.

    2015-12-01

    Osaka University has been developing interferometric lightning mapping systems for some time, first with narrow band VHF interferometers, and then with broadband digital VHF interferometers (DITF). Recently, a collaboration between New Mexico Tech and Osaka University resulted in the development of the NMT INTF. All of these interferometric lightning mapping systems have added greatly to our understanding of lightning physics. The next generation of digital broadband VHF interferometer is now being developed in Osaka, called the Lightning Imaging via VHF Emission (LIVE) interferometer. LIVE is capable of mapping lightning in real-time with sub-millisecond time resolution, or through post processing with sub-microsecond time resolution. Near-field corrections have been developed, so that sources very close to the array can be located accurately, and so that the baselines can lengthened for improved angular resolution. LIVE is capable of locating lighting over more than a 75 dB range of brightnesses, allowing the system to be extremely sensitive, and the long baselines allow for location uncertainties as low as tens of meters. Presented are observations of lightning recorded in the Kasai area of Japan, as well as the Pengerang region of Malaysia showing the capabilities of the LIVE interferometer.

  1. An introduction to acoustic emission

    Science.gov (United States)

    Scruby, C. B.

    1987-08-01

    The technique of acoustic emission (AE) uses one or more sensors to 'listen' to a wide range of events that may take place inside a solid material. Depending on the source of this high frequency sound, there are broadly three application areas: structural testing and surveillance, process monitoring and control, and materials characterization. In the first case the source is probably a defect which radiates elastic waves as it grows. Provided these waves are detectable, AE can be used in conjunction with other NDT techniques to assess structural integrity. Advances in deterministic and statistical analysis methods now enable data to be interpreted in greater detail and with more confidence than before. In the second area the acoustic signature of processes is monitored, ranging from for instance the machining of metallic components to the mixing of foodstuffs, and changes correlated with variations in the process, with the potential for feedback and process control. In the third area, AE is used as an additional diagnostic technique for the study of, for instance, fracture, because it gives unique dynamic information on defect growth.

  2. Ammonia in power plant emission

    Science.gov (United States)

    Hammerich, Mads; Henningsen, J. O.; Olafsson, Ari

    1990-08-01

    Ammonia monitoring is needed in most schemes for denitrification of power plant emission. In the PALAMON system we use a 500 MHz tunable, single mode, single line, CO2 laser as light source for a low pressure, high temperature, photoacoustic cell. With this cell we can resolve the sR(5,O) line of the ammonia spectrum, and suppress the interfering C02(9R30) absorption line down to a lppm NH3 detection limit. The validity of the measured ammonia concentrations is strongly dependent on details of the sampling system and on the reliability of the calibration routines. In particular calibration with certified mixtures of NH3:N2 has proved insufficient due to the multiple and long time constants caused by adsorption of ammonia to different materials in the system. Presence of water vapor in the gas greatly reduces these time constants. Therefore a number of methods for simple production of moist calibration gases from macroscopic amounts of NH3 are applied. The calibrations are translated to response from an easily managable absorber in order to allow automated recalibration of the photoacoustic response. Data from a field test of the system, and calibration data will be presented.

  3. Constraining CO emission estimates using atmospheric observations

    Science.gov (United States)

    Hooghiemstra, P. B.

    2012-06-01

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

  4. Electrifying emissions : reducing GHG emissions one step at a time

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, R.

    2010-05-15

    Four waste heat generation systems were installed at compressor stations in Saskatchewan as part of SaskPower's effort to reduce greenhouse gas emissions and produce electricity in an environmentally responsible manner. NRGreen Power Limited Partnership, a sister company of Alliance Pipeline Ltd., was awarded the contract to construct the 4 waste heat power generation units at compressor stations along Alliance's natural gas pipeline system. Using technology developed and manufactured by Ormat Technologies, Inc., the waste heat units recover the exhaust heat from natural gas turbines, which compress the gas to transport it through the pipeline, and convert it into electricity. Each unit produces 5 megawatts of power, enough energy to power approximately 5,000 homes. The units are located in Kerrobert, Estlin, Loreburn and Alameda, Saskatchewan. The 3 main components of the units are the heat exchanger, a thermal oil loop and an energy converter. A unique feature of the waste heat power generation system is that it is entirely self-contained. The compressors on the Alliance system operate about 99 per cent of the time with a high degree of reliability, which is key for an electricity provider. This same technology could be applied to other jurisdictions where the Alliance pipeline crosses. NRGreen is also proposing to build waste heat power generation units at 3 of its existing compressor stations in Alberta. NRGreen has regulatory approval to install the units at Irma, Morinville and Windfall. Although opportunities may arise in the United States, challenges remain in getting the technology recognized as environmentally preferred or equivalent to other renewable sources. 1 ref., 2 figs.

  5. Total hemispherical emissivity of Inconel 718

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

    Highlights: • We have measured the total hemispherical emissivity for Inconel 718 from about 600–1250 K. • Oxidation in air at 1073 K resulted in an increase in emissivity. • Sandblasting of Inconel 718 was also observed to increase the emissivity. • Coating of graphite powder onto the ‘as-received’ Inconel 718 showed no increase in the emissivity. • Coating of graphite powder onto the 220 grit sandblasted Inconel 718 did show an increase in emissivity. - Abstract: Total hemispherical emissivity for Inconel 718 was measured in anticipation of its application in Very High Temperature Gas Reactors (VHTRs). A majority of current emissivity data for Inconel 718 is in the form of spectral measurements. The data presented here were obtained with an experimental apparatus based on the standard ASTM C835-06 for total hemispherical emittance. Measurements of Inconel 718 were made for four different surface types including: (i) ‘as-received’ from the manufacturer, (ii) oxidized in air and humidified helium, (iii) sandblasted with aluminum oxide powder, and (iv) with a thin coating of nuclear grade graphite powder (grade NGB-18). The emissivity for the ‘as-received’ sample ranged from 0.21 to 0.28 in the temperature interval from 760 K to 1275 K. Oxidation in air at 1073 K resulted in an increase in emissivity into the range from 0.2 at 650 K to 0.52 at 1200 K. There was no dependence on the oxidation times studied here. Oxidation with humidified helium at 1073 K produced less of an increase in emissivity than the oxidation in air but there was an increase up to the range from 0.2 at 600 K to 0.35 at 1200 K. Sandblasting of Inconel 718 was also observed to increase the emissivity up to the range from 0.43 at 780 K to 0.53 at 1270 K when 60 grit sized powder was used and up to the range from 0.45 at 683 K to 0.57 at 1267 K when 120 and 220 grit sized powders were used. Coating of graphite powder onto the ‘as-received’ Inconel 718 showed no increase

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-07

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

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

    Science.gov (United States)

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

    2016-09-01

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

  8. Source mechanism of Saturn narrowband emission

    Directory of Open Access Journals (Sweden)

    J. D. Menietti

    2010-04-01

    Full Text Available Narrowband emission (NB is observed at Saturn centered near 5 kHz and 20 kHz and harmonics. This emission appears similar in many ways to Jovian kilometric narrowband emission observed at higher frequencies, and therefore may have a similar source mechanism. Source regions of NB near 20 kHz are believed to be located near density gradients in the inner magnetosphere and the emission appears to be correlated with the occurrence of large neutral plasma clouds observed in the Saturn magnetotail. In this work we present the results of a growth rate analysis of NB emission (~20 kHz near or within a probable source region. This is made possible by the sampling of in-situ wave and particle data. The results indicate waves are likely to be generated by the mode-conversion of directly generated Z-mode emission to O-mode near a density gradient. When the local hybrid frequency is close n fce (n is an integer and fce is the electron cyclotron frequency with n=4, 5 or 6 in our case, electromagnetic Z-mode and weak ordinary (O-mode emission can be directly generated by the cyclotron maser instability.

  9. Accounting For Greenhouse Gas Emissions From Flooded ...

    Science.gov (United States)

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

  10. Global civil aviation black carbon emissions.

    Science.gov (United States)

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

    2013-09-17

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

  11. Planck 2013 results. XIV. Zodiacal emission

    CERN Document Server

    Ade, P A R; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Cardoso, J.F.; Catalano, A.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colley, J.-M.; Colombi, S.; Colombo, L.P.L.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Ensslin, T.A.; Eriksen, H.K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giraud-Heraud, Y.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Laureijs, R.J.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Mottet, S.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; O'Sullivan, C.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polegre, A. M.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Reach, W.T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Smoot, G. F.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    The Planck satellite provides a set of all-sky maps at nine frequencies from 30 GHz to 857 GHz. Planets, minor bodies, and diffuse interplanetary dust emission (IPD) are all observed. The IPD can be separated from Galactic and other emissions because Planck views a given point on the celestial sphere multiple times, through different columns of IPD. We use the Planck data to investigate the behaviour of zodiacal emission over the whole sky at sub-millimetre and millimetre wavelengths. We fit the Planck data to find the emissivities of the various components of the COBE zodiacal model -- a diffuse cloud, three asteroidal dust bands, a circumsolar ring, and an Earth-trailing feature. The emissivity of the diffuse cloud decreases with increasing wavelength, as expected from earlier analyses. The emissivities of the dust bands, however, decrease less rapidly, indicating that the properties of the grains in the bands are different from those in the diffuse cloud. We fit the small amount of Galactic emission seen t...

  12. Soil emissivity and reflectance spectra measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sobrino, Jose A.; Mattar, Cristian; Pardo, Pablo; Jimenez-Munoz, Juan C.; Hook, Simon J.; Baldridge, Alice; Ibanez, Rafael

    2009-07-01

    We present an analysis of the laboratory reflectance and emissivity spectra of 11 soil samples collected on different field campaigns carried out over a diverse suite of test sites in Europe, North Africa, and South America from 2002 to 2008. Hemispherical reflectance spectra were measured from 2.0 to 14 {mu}m with a Fourier transform infrared spectrometer, and x-ray diffraction analysis (XRD) was used to determine the mineralogical phases of the soil samples. Emissivity spectra were obtained from the hemispherical reflectance measurements using Kirchhoff's law and compared with in situ radiance measurements obtained with a CIMEL Electronique CE312-2 thermal radiometer and converted to emissivity using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) temperature and emissivity separation algorithm. The CIMEL has five narrow bands at approximately the same positions as the ASTER. Results show a root mean square error typically below 0.015 between laboratory emissivity measurements and emissivity measurements derived from the field radiometer.

  13. Study of luminous emissions associated to electron emissions in radiofrequency cavities; Etude des emissions lumineuses associees aux emissions electroniques dans les cavites hyperfrequences

    Energy Technology Data Exchange (ETDEWEB)

    Maissa, S

    1996-11-26

    This study investigates luminous emissions simultaneously to electron emissions and examines their features in order to better understand the field electron emission phenomenon. A RF cavity, operating at room temperature and in pulsed mode, joined to a sophisticated experimental apparatus has been especially developed. The electron and luminous emissions are investigated on cleaned or with metallic, graphitic and dielectric particles contaminated RF surfaces in order to study their influence on these phenomena. During the surface processing, unstable luminous spots glowing during one RF pulse are detected. Their apparition is promoted in the vicinity of the metallic particles or scratches. Two hypotheses could explain their origin: the presence of micro-plasmas associated to electronic explosive emission during processing or the thermal radiation of the melted metal during this emission. Stable luminous spots glowing during several RF pulses are also detected and appear to increase on RF surfaces contaminated with dielectric particles, leading to strong and explosive luminous emissions. Two interpretations are considered: the initiation of surface breakdowns on the dielectric particles or the heating by the RF field at temperatures sufficiently intense to provoke their thermal radiation then their explosion. Finally a superconducting cavity has been adapted to observe luminous spots, which differ from the former ones bu their star shape and could be associated to micro-plasmas, revealed by the starbursts observed on superconducting cavity walls. (author) 102 refs.

  14. Mobile source emissions inventory development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fang, K.Y.; De Paul, F.T.; Heavisides, T.; Wagner, D.

    1991-03-01

    The study was undertaken to develop a methodology for preparing a 5km by 5km areal gridded mobile source emissions inventory for areas of Illinois which are in nonattainment status with regard to National Ambient Air Quality Standards. A pilot emissions inventory was developed by linking the USEPA mobile source emissions program (MOBILE4) with existing traffic data from the Illinois Department of Transportation's (IDOT) Highway Record Data Bank (HRDB), the Chicago Area Transportation Study (CATS) and Illinois Department of Energy and Natural Resources' (ENR) Geographic Information System (GIS). The methodology developed here was applied to one pollutant in one test case county in Illinois. Hydrocarbon emissions from mobile sources in Kane county are the focus of the study. Vehicle type, vehicle age, and Vehicle Miles of Travel (VMT) distributions were obtained from information provided in the 1982 Illinois State Implementation Plan (SIP). Among the products of the project is a preliminary 25-sq km gridded mobile source hydrocarbon emissions inventory for Kane county. Numerical results as well as a color correlated overview map of the county-wide gridded emissions inventory are provided in the report. Recommendations for improving the methodology and further developing gridded mobile source emission inventories for other Illinois counties are also provided.

  15. Radioactive air emissions 1992 summary. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, L. [comp.

    1993-10-01

    This report summarizes, by radionuclide or product and by emitting facility, the Laboratory`s 1992 radioactive air emissions. In 1992, the total activity of radionuclides emitted into the air from Laboratory stacks was approximately 73,500 Ci. This was an increase over the activity of the total 1991 radioactive air emissions, which was approximately 62,400 Ci. Total 1992 Laboratory emissions of each radionuclide or product are summarized by tables and graphs in the first section of this report. Compared to 1991 radioactive air emissions, total tritium activity was decreased, total plutonium activity was decreased, total uranium activity was decreased, total mixed fission product activity was increased, total {sup 41}Ar activity was decreased, total gaseous/mixed activation product (except {sup 41}Ar) activity was increased, total particulate/vapor activation product activity was increased, and total {sup 32}P activity was decreased. Radioactive emissions from specific facilities are detailed in this report. Each section provides 1992 data on a single radionuclide or product and is further divided by emitting facility. For each facility from which a particular radionuclide or product was emitted, a bar chart displays the air emissions of each radionuclide or product from each facility over the 12 reporting periods of 1992, a line chart shows the trend in total emissions of that radionuclide or product from that facility for the past three years, the greatest activity during the 1990--1992 period is discussed, and unexpected or unusual results are noted.

  16. Methane emission during municipal wastewater treatment.

    Science.gov (United States)

    Daelman, Matthijs R J; van Voorthuizen, Ellen M; van Dongen, Udo G J M; Volcke, Eveline I P; van Loosdrecht, Mark C M

    2012-07-01

    Municipal wastewater treatment plants emit methane. Since methane is a potent greenhouse gas that contributes to climate change, the abatement of the emission is necessary to achieve a more sustainable urban water management. This requires thorough knowledge of the amount of methane that is emitted from a plant, but also of the possible sources and sinks of methane on the plant. In this study, the methane emission from a full-scale municipal wastewater facility with sludge digestion was evaluated during one year. At this plant the contribution of methane emissions to the greenhouse gas footprint were slightly higher than the CO₂ emissions related to direct and indirect fossil fuel consumption for energy requirements. By setting up mass balances over the different unit processes, it could be established that three quarters of the total methane emission originated from the anaerobic digestion of primary and secondary sludge. This amount exceeded the carbon dioxide emission that was avoided by utilizing the biogas. About 80% of the methane entering the activated sludge reactor was biologically oxidized. This knowledge led to the identification of possible measures for the abatement of the methane emission.

  17. Economic growth and greenhouse gas emissions

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-01-01

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

  18. Accounting For Greenhouse Gas Emissions From Flooded ...

    Science.gov (United States)

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

  19. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-04-01

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

  20. Isoprene emission from tropical tree species

    Energy Technology Data Exchange (ETDEWEB)

    Padhy, P.K. [School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)]. E-mail: padhypk2003@yahoo.com; Varshney, C.K. [School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)

    2005-05-01

    Foliar emission of isoprene was measured in nine commonly growing tree species of Delhi, India. Dynamic flow enclosure technique was used and gas samples were collected onto Tenax-GC/Carboseive cartridges, which were then attached to the sample injection system in the gas chromatograph (GC). Eluting compounds were analysed using a flame ionisation detector (FID). Out of the nine tree species, isoprene emission was found in six species (Eucalyptus sp., Ficus benghalensis, Ficus religiosa, Mangifera indica, Melia azedarach, and Syzygium jambolanum), whereas, in the remaining three tree species (Alstonia scholaris, Azadirachta indica, and Cassia fistula) no isoprene emission was detected or the levels of emission were negligible or below the detection limit (BDL). Among six tree species, the highest hourly emission (10.2{+-}6.8 {mu}g g{sup -1} leaf dry weight, average of five seasons) was observed in Ficus religiosa, while minimum emission was from Melia azedarach (2.2{+-}4.9 {mu}g g{sup -1} leaf dry weight, average of five seasons). Isoprene emission (average of six species), over five seasons, was found to vary between 3.9 and 8.5 {mu}g g{sup -1} leaf dry weight during the rainy season. In addition, significant diurnal variation in isoprene emission was observed in each species. The preliminary estimate made in this study on the annual biogenic VOC emission from India may probably be the first of its kind from this part of the world. - Isoprene flux (diurnal and seasonal) from some tropical tree species was estimated and a regional comparison was made.